JPH09196164A - Speed change control device of automatic transmission for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce generation of a gear tooth hitting sound of a large level by prohibiting a preselect means from performing preselect when judged that a present operation condition is an operation condition of generating a gear tooth hitting sound of a large level when the preselect is performed. SOLUTION: A present gear stage GN, throttle opening TA and output rotating speed NT of a transmission are read in (S501). Next, whether or not it is a third speed stage is judged. As a result, in the case of NO, preselect is performed. On the other hand, in the case of YES (S503), whether or not a present operation condition is put in an area to perform preselect is judged (S509). As a result, in the case of YES, a second sleeve actuator is actuated (S510) so that a second sleeve 52 connects a second speed clutch gear G2 and a second hub to each other. In the case of NO (S509), a first sleeve 51 is actuated (S511) so as to be in an intermediate position, and is returned (S512).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called twin clutch type automatic transmission for vehicles, and more particularly to a shift control device thereof.

[0002]

2. Description of the Related Art Two clutches connected to a transmission input shaft, and a plurality of gear trains for selectively connecting a clutch output shaft of these clutches and a transmission output shaft by a selection operation of a gear selection device. By engaging one clutch and releasing the other clutch, and connecting the clutch output shaft of one clutch, the transmission output shaft, and the transmission output shaft via a gear train. A so-called twin clutch type automatic transmission for vehicles of the type that achieves a gear stage is known (see Japanese Patent Laid-Open No. 6-221347).

[0003]

By the way, in this twin clutch type automatic transmission for a vehicle, in order to shorten the shift time to the next stage, a predetermined gear selection mechanism is operated prior to the shift determination, Preselection control is performed in which the clutch output shaft of the clutch that is not currently engaged and the transmission output shaft are connected through a predetermined gear train and are on standby. However, when preselect control is performed, there are many gears connected in series depending on the gear stage,
Further, due to the large inertial mass, gear rattling noise is generated and the level thereof is large.

In view of the above problems, it is an object of the present invention to reduce or prevent gear rattle noises in a twin clutch type automatic transmission for a vehicle.

[0005]

According to the invention of claim 1, the two clutches connected to the transmission input shaft and the gear selector between the clutch output shaft and the transmission output shaft of these clutches are provided. A plurality of gear trains that are selectively connected by a selection operation, engage one clutch and release the other clutch, and connect the clutch output shaft of one clutch and the transmission output shaft to the gear train. A gear shift control device for an automatic transmission for a vehicle of a type that achieves a desired gear stage by connecting via a gear, wherein a predetermined gear selection device is operated when a certain gear stage is achieved, The clutch output shaft and the transmission output shaft of the clutch that is not used to achieve the gear stage are connected to each other via a predetermined gear train, and preselection means for executing a preselection is held. Driving state detecting means for detecting the driving state of the vehicle and the current driving state, when the preselection is executed, a driving state in which a gear tooth ratting noise with a large level is generated or a gear tooth ratting noise with a small level is generated. And a determination means for determining whether the pre-selection is performed, the pre-selection is performed when the pre-selection is performed. There is provided a shift control device characterized in that the selection means prohibits execution of preselection.

In the shift control device thus constructed, preselection is not executed when it is determined that the operating state is such that a gear tooth rattling noise of a high level is generated when preselection is executed.

According to the invention of claim 2, in the shift control device according to claim 1, further, there is a possibility that there is a great demand for a sudden acceleration accompanied by a downshift or a demand for a sudden acceleration accompanied by a downshift. A determination means for determining an almost impossible operating state is provided, and the current operating state is an operating state in which gear rattle noise of a gear having a large level is generated when the preselection is executed, and a request for sudden acceleration accompanied by a downshift. There is provided a shift control device for prohibiting the preselection means from executing preselection when it is determined that the operating state is almost impossible.

In the gear shift control device constructed as described above, in a driving state in which a gear rattling noise of a high level gear is generated when the preselection is executed, a driving state in which there is almost no demand for sudden acceleration accompanied by a downshift. If it is determined that, preselect is not executed.

According to a third aspect of the present invention, the gear shift control device according to the second aspect further includes downshift means for selectively executing the downshift, and the present operating state executes the preselection. If it is determined that the operating condition is such that a gear rattling noise of a high level is generated, and there is a strong demand for sudden acceleration accompanied by a downshift, the downshift means executes the downshift. A shift control device configured to do so is provided.

In the gear shift control device constructed as described above, in a driving state in which a gear tooth rattling noise with a large level is generated when preselection is executed, and in a driving state in which there is a great demand for sudden acceleration accompanied by a downshift. If it is determined that there is a downshift, the downshift is executed.

According to the invention of claim 4, in the shift control device according to claim 1 or 2, further, when the current operating state prohibits the execution of the preselection, the gear having a large level is provided. A driving state in which gear rattling noise is generated, a means for determining whether a gear tooth rattling noise with a low level is generated, and downshift means for selectively executing downshift are provided. Even if the execution of the preselection is prohibited, the downshift means executes the downshift when it is determined that the operating state is such that a gear tooth rattling noise of a high level is generated. A shift control device is provided.

In the shift control device thus constructed, it is determined that the current operating state is an operating state in which a gear tooth rattling noise of a high level is generated even when the execution of preselection is prohibited. If so, the downshift is executed.

According to the invention of claim 5, two clutches connected to the transmission input shaft and between the clutch output shaft of these clutches and the transmission output shaft are selectively operated by a selection operation of the gear selection device. By connecting a plurality of gear trains, engaging one clutch and releasing the other clutch, and connecting the clutch output shaft of one clutch and the transmission output shaft via the gear train. A shift control device for a vehicle automatic transmission of a type that achieves a desired gear stage, wherein a predetermined gear selection device is operated when a certain gear stage is achieved to achieve a current gear stage. It has preselection means for executing preselection in which the clutch output shaft of the clutch that is not used and the transmission output shaft are connected through a predetermined gear train to make them stand by. A weak engagement means for selectively weakly engaging one of the clutches that is not used, and the weak engagement means performs weak engagement when the preselection means performs the preselection. A shift control device is provided.

In the shift control device thus constructed, when executing preselection, the clutch that is not used for achieving the current gear is weakly engaged.

According to a sixth aspect of the present invention, in the gear shift control device according to the fifth aspect, the operating state detecting means for detecting the operating state of the vehicle and the current operating state perform the preselection. In this case, a determination means is provided for determining whether the operating state in which a gear tooth ratting noise of a high level is generated or the operating state in which a gear tooth ratting noise of a low level is generated, and the current operating state is the pre-selection performed. In this case, there is provided a shift control device that prohibits the weak engagement means from performing weak engagement when it is determined that the operating state is such that a gear tooth rattling sound of a low level is generated.

In the shift control device thus constructed, the preselection is executed when it is determined that the gear tooth rattling noise of a low level is generated when the preselection is executed. Occasionally, the clutch that is not used to achieve the current gear will not be lightly engaged.

According to the invention of claim 7, in the shift control device according to claim 2, the weak engagement means for weakly engaging the clutch which is not used for achieving the current gear stage. It is determined that the current operating state is an operating state in which a gear tooth rattling noise of a high level is generated when the preselection is executed, and an operating state in which a sudden acceleration request accompanied by a downshift is highly likely. In this case, a shift control device is provided in which the weak engagement means executes weak engagement.

In the shift control device having such a configuration, in the operating state in which the gear tooth rattling noise of a large level is generated when the preselection is executed, the operating state in which there is a great demand for the sudden acceleration accompanied by the downshift. If it is determined that the clutch is not engaged, the clutch not used for achieving the current gear is weakly engaged.

According to an eighth aspect of the present invention, in the shift control device according to the second aspect, a torque converter having a lockup clutch that can be connected and disconnected is further connected to the transmission input shaft, and the present gear is used. A weak engagement means for weakly engaging the clutch that is not used to achieve the step is provided, and the current operating state is such that a gear tooth rattling noise of a large level is generated when the preselection is performed. If it is determined that the operating condition is such that there is a strong demand for sudden acceleration accompanied by a downshift, the weak engagement means performs weak engagement or causes the lockup clutch to be released. A shift control device is provided.

In the gear shift control device constructed as described above, in a driving state in which a gear tooth rattling noise of a high level is generated when preselected, it is possible that there is a great demand for a sudden acceleration accompanied by a downshift. If judged,
The clutch that is not used to achieve the current gear is either lightly engaged or the lockup clutch is disengaged.

According to the invention of claim 9, in the shift control device according to claim 8, the power loss when the weak engagement means is actuated and the power loss when the lockup clutch is released. By comparison, there is provided a shift control device that is operated with less power loss.

In the shift control device thus constructed, the power loss in the case of weakly engaging the clutch which is not used to achieve the current gear and the release of the lock-up clutch. The power loss in the case is compared and the operation with the smaller power loss is executed.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram schematically showing the overall structure of a twin-clutch four-speed automatic transmission having a torque converter to which the present invention is applied. Referring to FIG. 1, 1 represents an engine, 2 represents a torque converter with a lockup mechanism, and 3 represents a twin clutch type automatic transmission. As shown in the figure, the output shaft 10 of the engine 1 is connected to the front cover 20 of the torque converter 2, and the front cover 20 is connected via a fluid flow to a pump impeller 21 and a turbine 22 or, It is connected to a torque converter output shaft 24 via a lockup clutch 23, and the output shaft of the torque converter 24 is connected to an input shaft 30 of the twin clutch type automatic transmission 3 so as to be integrally rotatable. In addition, 25 is a stator and 26 is a one-way clutch.

A first clutch input disk C1 _{i of} the first clutch C1 and a second clutch input disk C2 _{i of} the second clutch C2, which form the clutch C, are connected to the input shaft 30. The first clutch output shaft 40 and the second clutch output shaft 50 are connected to the first clutch output disk C1 _o of the first clutch C1 and the second clutch output disk C2 _o of the second clutch C2, respectively. Coaxially connected to the outside. The sub shaft 60 and the output shaft 70 are arranged in parallel to these shafts.

The second clutch output shaft 50 has a clutch C.
, The second speed drive gear I ₂ , the countershaft drive gear I _S , and the fourth speed drive gear I ₄ are fixedly connected. On the other hand, the first clutch output shaft 40 is connected to the third speed drive gear I ₄ so as to be adjacent to the fourth speed drive gear I _4.
3 , and the first speed drive gear I ₁ is fixedly connected to the torque converter 2 side.

[0026] The output shaft 70, from the side of the clutch C, the fourth speed driven gear O ₄ to the second speed driven gear O _2, always in mesh with the fourth speed drive gear I ₄ which always meshes with the second speed drive gear I ₂ , third speed driven gear O ₃ which always meshes with the third speed drive gear I _3, first speed drive gear I ₁
The first-speed driven gear O ₁ constantly meshing with
It is rotatably mounted. Furthermore, between the first speed driven gear O ₁ and the third speed driven gear O ₃ is first synchronizer D1, a fourth speed driven gear O ₄ between the second speed driven gear O ₂ and the second synchronization device D2 distribution Has been established.

The first synchronizer D1 comprises a first hub H1 fixedly connected to the output shaft 70 and a first sleeve S1 axially slidably mounted on the outer peripheral end of the first hub H1. the sleeve S1, via the first shift fork Y1 moved by a first sleeve actuator ACT1, is fixedly coupled to the first driven gear O ₁ first
High speed clutch gear G ₁ or third speed driven gear O ₃
The first speed driven gear O ₁ and the third speed driven gear O ₃ are selectively connected to the output shaft 70 by engaging the third speed clutch gear G ₃ which is fixedly coupled to the output shaft 70.

Similarly, the second synchronizer D2 is attached to the output shaft 70.
The second hub H2, which is fixedly connected, and the outer peripheral edge of the second hub H2
From the second sleeve S2 mounted slidably in the axial direction
The second sleeve S2 is connected to the second shift fork Y
2 through a second sleeve actuator ACT2.
And move to the 4th speed driven gear O_FourFixedly connected to
Fourth speed clutch gear G_FourOr second-speed driven gear
Ya O_TwoSpeed clutch gear G fixedly connected to_TwoTo
4th driven gear O _Fourand
2nd speed driven gear O_TwoIs selectively connected to the output shaft 70.
Let

The auxiliary shaft 60 is attached to the auxiliary shaft 60 from the clutch C side.
Drive gear I_SDriven gear that always meshes with
O_S, First speed drive gear I₁And idler gear M_RThrough
Reverse drive gear I that always meshes_RIs arranged
Of these, the countershaft driven gear O _SIs fixed to counter shaft 60
, Which always rotates together with the counter shaft 60, but
Live gear i_RIs rotatably mounted,
The third synchronizing device D3 arranged in the middle of the
Is selectively connected to the counter shaft 60.

The third synchronizer D3 comprises a third hub H3 fixedly connected to the countershaft 60 and a third sleeve S3 axially slidably mounted on the outer peripheral end of the third hub H3. the sleeve S3 via the third shift fork Y3 moved by a third sleeve actuator ACT3, by engaging the reverse clutch gear G _R which is fixedly coupled to the reverse drive gear I _R, select reverse drive gear I _R To rotate integrally with the sub shaft 60.

FIG. 2 shows the engagement states of the first clutch C1, the second clutch C2, the first sleeve S1, the second sleeve S2, and the third sleeve S3 at each shift speed. The circles with a circle indicate the engagement for transmitting the power at the shift speed, and the triangles and indicate the engagement added when the preselection for speeding up the shift is performed. A symbol attached to the first gear, a third gear, and a fourth gear represents preselection for a downshift, and a symbol attached to a first gear represents preselection for an upshift. Then, the engagement added by the preselection does not contribute to the transmission of power at that shift speed.

Here, in the second speed and the third speed, not only the downshift but also the upshift may occur, but only the preselect prepared for the downshift is shown. However, upshifting occurs when rapid acceleration is not required, and it is necessary to preselect in advance to prepare for an unexpected shift and accelerate the shift. Because it is small.

FIG. 3 shows the connecting relationship of the rotating members from the output disk of the clutch to the output shaft 70 in the forward stage shown in FIG. The solid lines connecting □, ○, and ◇ indicate the transmission paths for transmitting power. In each case, □ indicates the power input member in the above section, and ◇ indicates the output member. The symbol ◯ indicates a member that rotates for the transmission of power between the input unit and the output unit. The ones that connect ■, ●, and ◆ show the paths that do not transmit power, but the ones that are connected by the solid line are not due to the result of preselection, but are associated with the connection for transmitting power. Those that occur are those that are connected by broken lines are the result of preselection and are the paths prepared for downshifting (or upshifting), and those that are connected by the dotted lines are those that result from preselection. Does not contribute to the transmission of power in the gear after the downshift (or upshift). And ■
Indicates that a member that applies a rotational force is shown in the path, the solid diamond indicates the open end of the path, and the solid circle indicates a member that rotates in the middle.

For example, since the first clutch C1 is engaged at the first speed, the first clutch output shaft 40 connected to the first clutch output disk C1 _o is the first speed drive gear I.
_1st , 1st speed driven gear O which rotates together with 3rd speed drive gear I ₃ and is constantly meshed with 1st speed drive gear I _1.
1 is rotated, then, the first sleeve S1 is output shaft 70 is rotated first hub H1, together with the second hub H2 by being located in the first-speed clutch gear G ₁ side, power is transmitted . Further, the third-speed driven gear O ₃ always meshing with the third-speed drive gear I ₃ also rotates, but the third-speed driven gear O ₃ is not coupled to the output shaft 70 and therefore rotates only without load. . The second sleeve S2 is the second
_2nd when pre-selected to the _high speed clutch gear G ₂ side
The speed driven gear O ₂ is rotated and, as a result, the second
Fast driven gear O ₂ in constant mesh to have a second speed drive gear I ₂ and a second clutch output shaft 50, fourth speed drive gear I _4, rotates together with the secondary drive gear I _S. Therefore, the second clutch output disk C2 _o coupled to the second clutch output shaft 50, and the auxiliary shaft driven gear O _S which is always meshed with the auxiliary shaft drive gear I _S are the auxiliary shaft 6 and
0, rotates together with the third hub H3, also rotates the fourth speed driven gear O ₄ being always in mesh with the fourth speed drive gear I _4.

Since the second clutch C2 is engaged at the second speed, the second clutch output shaft 50 connected to the second clutch output disk C2 _o is connected to the second drive gear I ₂ and the second clutch output shaft 50.
It rotates together with the clutch output shaft 50, the fourth speed drive gear I ₄ , and the countershaft drive gear I _S to form the second speed drive gear I ₂
The second-speed driven gear O _2, which always meshes with
Then, the output shaft 70 by the second sleeve S2 is positioned in the second speed clutch gear G ₂ side first hub H1,
It rotates together with the second hub H2, and power is transmitted. Also,
The fourth speed driven gear O ₄ which is always meshed with the fourth speed drive gear I ₄ also rotates, but the fourth speed driven gear O ₄ is not connected to the output shaft 70 and therefore only rotates with no load. Further, the auxiliary shaft driven gear O _S meshing constantly auxiliary drive gear I _S rotates countershaft 60, together with the third hub H3. When the first sleeve S1 is preselected on the first speed clutch gear G ₁ side, the first speed driven gear O ₁ is rotated, and as a result, the first speed driven gear O ₁ is always meshed with the first speed driven gear O ₁ . High speed drive gear I ₁
There first clutch output shaft 40, rotates together with the third speed drive gear I _3. Therefore, also rotates the third speed driven gear O ₃ being always in mesh with the third speed drive gear I _3.

At the third speed, the first clutch C1 is engaged, so the first clutch output shaft 40 connected to the first clutch output disk C1 _o has the first clutch drive shaft I ₁ and the third clutch output shaft 40.
Rotates with speed drive gear I _3, always in mesh with the third speed drive gear I ₃ is the third-speed driven gear O ₃ and rotating it, then the third sleeve S3 as described above third speed clutch gear G _The output shaft 70 is located on the _third side.
Rotates with the first hub H1 and the second hub H2, and power is transmitted. Further, the first speed driven gear O ₁ that is always meshed with the first speed drive gear I ₁ also rotates, but since the first speed driven gear O ₁ is not connected to the output shaft 70, it only rotates with no load. . The second sleeve S2 when being preselect the second speed driven gear O ₂ is rotated to the second speed clutch gear G ₂ side, as a result,
Second speed drive gear I ₂ being always in mesh with the second speed driven gear O ₂ and the second clutch output shaft 50, fourth speed drive gear I _4, rotates together with the secondary drive gear I _S. Therefore, the second clutch output disk C2 _o coupled to the second clutch output shaft 50, and the auxiliary shaft driven gear O _S which is constantly meshed with the auxiliary shaft drive gear I _S together with the auxiliary shaft 60 and the third hub H3. The fourth driven gear O that rotates and is constantly meshed with the _fourth drive gear I _4.
4 also rotates.

Since the second clutch C2 is engaged in the fourth speed, the second clutch output shaft 50 connected to the second clutch output disk C2 _o is connected to the second speed drive gear I ₂ and the second clutch output shaft 50.
It rotates together with the clutch output shaft 50, the fourth speed drive gear I ₄ , and the countershaft drive gear I _S to form the fourth speed drive gear I ₄
The fourth-speed driven gear O _4, which is always meshed with, rotates,
Then, the output shaft 70 by the second sleeve S2 is positioned in the fourth speed clutch gear G ₄ side first hub H1,
It rotates together with the second hub H2, and power is transmitted. Also,
The second speed driven gear O ₂ which is always meshed with the second speed drive gear I ₂ also rotates, but the second speed driven gear O ₂ is not connected to the output shaft 70 and therefore only rotates with no load. Further, the auxiliary shaft driven gear O _S meshing constantly auxiliary drive gear I _S rotates countershaft 60, together with the third hub H3. The first sleeve S1 is the is the preselect the third speed driven gear O ₃ is rotated to the third speed clutch gear G ₃ side, as a result, the third being always in mesh with the third speed driven gear O ₃ High speed drive gear I ₃
There first clutch output shaft 40, rotates together with the first speed drive gear I _1. Therefore, also rotates the first-speed driven gear O ₁ being always in mesh with the first speed drive gear I _1.

When the preselection is performed in preparation for the downshift (upshift in the first gear) as described above, the elements not used for transmitting the engine torque are also rotated, and among them, the elements are mutually rotated. It contains many meshed gears. However, as for the gear, if load is applied to the driven side, contact between tooth flanks is maintained and no rattling noise is generated, but as described above, preselection is performed and engine torque is reduced. When it is not used for transmission and is rotated without load, rattling occurs between the tooth surfaces, and the tooth surfaces hit each other, resulting in a rattling noise. The present invention aims to reduce or prevent the gear rattling noise when this preselection is performed, and the specific means thereof will be described later, but prior to that, the nature of the gear rattling sound will be described.

This tooth rattling sound is caused by the direct engagement that causes backlash.
Included in the column, the fluctuation range is amplified and
You. That is, for example, to prepare for a downshift at the third speed
2nd speed driven gear as if pre-selected
O_TwoThe 2nd speed drive connected by the meshing
Eve Gear I_TwoAnd countershaft drive gear I_SAnd 4th speed drive
Gear I_FourRotates integrally, and this sub
Shaft drive gear I_SAnd 4th speed drive gear I _FourMore
The secondary shaft driven gear O_SAnd the second
4-speed driven gear O_FourWhen the are connected
Becomes larger.

Therefore, it is important in the present embodiment to prevent or reduce backlash. The amount of energy of this rattling sound is influenced by the amount of rattling and the amount of inertia of the driven member.

Here, the driven side member in the path that does not transmit power at the time of preselection at each shift speed is the second clutch output disk C2 _o which is integrally connected at the first speed and the third speed. And the second clutch output shaft 50, the auxiliary shaft drive gear I _S , the second speed drive gear I _2, and the fourth speed drive gear I ₄ , which are integrally connected in the second speed and the fourth speed. The first clutch output disk C1 _o , the first clutch output shaft 40, the first speed drive gear I ₁ and the third speed drive gear I ₃ .

In the embodiment of the present invention, the second clutch output disk C2 _o is the first clutch output disk C1 _o.
The second clutch output disk C2 _o and the second clutch output shaft 5 that are integrally connected to each other and may be disposed outside the
0, the auxiliary shaft drive gear I _S , the second speed drive gear I _2, and the fourth speed drive gear I ₄ have moments of inertia of the first clutch output disk C1 _o , the first clutch output shaft 40, and the first clutch output shaft C1 which are integrally connected. It is larger than the moment of inertia of the high speed drive gear I ₁ and the third speed drive gear I ₃ .

On the other hand, the following is a comparison of the input rotation speeds of the driven side members. Now, assuming that the rotation speed of the clutch output shaft is N, the rotation speed of the output shaft 70 at each gear is as follows. First speed: N / r1 (r1 is a reduction ratio from the first speed drive gear I ₁ to the first speed driven gear O ₁ ) Second speed: N / r2 (r2 is from the second speed drive gear I ₂ Reduction ratio to 2nd driven gear O ₂ ) 3rd speed: N / r3 (r3 is reduction ratio from 3rd speed drive gear I ₃ to 3rd driven gear O ₃ ) 4th speed: N / r4 (r4 Is the reduction ratio from the 4th speed drive gear I ₄ to the 4th speed driven gear O ₄ )

Therefore, the input rotational speed of the driven member is the above rotational speed divided by the reciprocal of the reduction ratio of the gear engaged during preselection. That is, it becomes as follows. First-speed preselect (for upshift): (N / r1) / (1 / r2) = N × (r2 / r1) Second-speed preselect (for downshift): (N / r2) / (1 / r1) = N × (r1 / r2) Preselection for third gear (for downshift): (N / r3) / (1 / r2) = N × (r2 / r3) Fourth gear Preselection (for downshift): (N / r4) / (1 / r3) = N × (r3 / r4)

Here, considering that r1>r2>r3> r4 and the magnitude of the moment of inertia described above,
Inertial energy ∝ Inertia moment × (rotational angular velocity) ² , so the inertial energy of the driven member is maximum when preselected at the third speed (for downshift).

Therefore, in each of the embodiments of the present invention, measures are taken especially for reducing gear rattling noise when preselected (for downshifting) at the above-mentioned third speed stage. The following methods are adopted individually or in combination. One is to make the preselection area as small as possible to narrow the range of rattling noise, and one is to downshift to increase the rotation speed.
One is to reduce the fluctuation of the torque input from the engine.One is to apply a load to prevent rattling between the tooth flanks of the gear, and one is the applicable range. Is limited to the lockup region, but the lockup clutch is released to reduce the fluctuation of the torque input from the engine.

The above measures control the engagement and release of the first clutch C1 and the second clutch C2, the movement of the first sleeve S1 and the second sleeve S2 to predetermined positions, and the engagement and release of the lockup clutch. It is done by doing.

Engagement and disengagement of the first clutch C1 and the second clutch C2 are controlled by the first clutch / clutch plate (shown in the figure) connected to the first clutch input disk C1 _i and the second clutch input disk C2 _i , respectively. No.), a second clutch / clutch plate (not shown), a first clutch piston (not shown) hydraulically driven, a second clutch piston (not shown)
This is performed by frictionally engaging a first clutch / clutch plate (not shown) and a second clutch / clutch plate (not shown) connected to the first clutch output disk C1 _o and the second clutch output disk C2 _o . Then, the piston is driven by controlling the supply and discharge of the hydraulic oil supplied from the hydraulic pressure supply source OP in FIG. 1, to the first clutch supply hydraulic pressure control valve VC1 and the second clutch supply hydraulic pressure control. Valve V
This is performed by controlling C2 by an electronic control unit (hereinafter referred to as ECU) 100.

Further, the first sleeve S1 and the second sleeve S
2, the movement of the third sleeve S3 is performed by the first sleeve actuator ACT1, the second sleeve actuator ACT2, and the third sleeve actuator ACT3, respectively, as described above. Although a detailed description of the structure of each actuator is omitted, the shift fork moves the piston connected thereto in a desired direction, and hydraulic oil supplied from a hydraulic pressure source P0 is formed on both sides of the piston. This is performed by controlling the supply and discharge of the piston oil chambers, and for this purpose, there are valves that control the supply of hydraulic oil to each piston oil chamber and valves that control the discharge of hydraulic oil from each piston oil chamber. The ECU 100 controls opening and closing of these valves.

Further, engagement of the lockup clutch 23,
As is known, the release control is performed by flowing hydraulic oil from between the front cover 20 and the lockup clutch 23 toward the pump 21 and the stator 25, or conversely from the front between the pump 21 and the stator 25. This is performed by flowing hydraulic oil between the cover 20 and the lockup clutch 23, and a lockup hydraulic control valve VL for that purpose is provided, and the lockup hydraulic control valve VL is also the ECU 10.
Controlled by 0.

The ECU 100 is composed of a digital computer, and the input interface circuits 1 connected to each other.
01, ADC (analog-to-digital converter) 102, CP
U (microprocessor) 103, RAM (random access memory) 104, ROM (read only memory)
105 and an output interface circuit 106.

The CPU 103 includes a gear position sensor 111 for detecting a gear position, a transmission output shaft speed sensor 112 for detecting a transmission output shaft speed, a throttle opening sensor 113 for detecting a throttle opening, and an engine speed. The output signal of each sensor such as the engine speed sensor 114 for detecting the number is input via the input interface circuit 101 or further via the ADC 102. CPU
Reference numeral 103 denotes a first clutch hydraulic pressure control for controlling a clutch of the twin clutch type automatic transmission to perform a later-described calculation from the values of the various sensors and data stored in the ROM 105 to reduce the rattling noise. Generating and outputting a signal for controlling the valve VC1 and the second clutch supply hydraulic control valve VC2, a signal for controlling an actuator for moving each sleeve, and a signal for controlling a lockup hydraulic control valve VL for controlling the lockup clutch. It is sent to each via the interface circuit 106.

Each embodiment will be described below. First, the control of the first embodiment will be described. The control of the first embodiment is of a type in which the preselection area is made small, and when the preselection is performed as described above, a third level as an operating state in which a gear tooth rattling noise with a high level is generated In the speed stage, downshift is a high output state of high rotation of the engine after downshifting, and it tries to perform rapid acceleration by utilizing the torque amplification effect of the automatic transmission. If you are currently traveling at a low speed and low output that does not allow you to obtain the high output state of, do not preselect.

Therefore, in the first embodiment,
At the 3rd speed stage, with respect to the transmission output shaft speed NT and the throttle opening TA as shown in FIG. 4, it is a region in which a rapid acceleration with a downshift is greatly required, or a rapid acceleration with a downshift is required. It has a map that shows areas that should be preselected and areas that should not be preselected, created considering whether or not areas are rarely requested, and the current operating state is to execute preselection. Preselection is carried out in the region where it should be executed, and preselection is not carried out in the region where it should not be executed.

FIG. 5 is a flow chart of a routine for controlling execution and cancellation of the above preselection. In step 501, the current gear stage GN is determined from the signal from the gear stage sensor 111 and the throttle opening sensor is detected. The throttle opening TA is read from the signal from 113 and the transmission output shaft rotation speed NT is read from the signal from the transmission output shaft rotation speed sensor 112. In step 502, it is determined whether or not it is the third speed.

As a result, if NO, that is, if it is determined not to be the third speed, the process proceeds to step 503 so that preselection is executed according to the gear, and first, the gear is set to the first speed. If it is YES, the routine proceeds to step 504, where the second sleeve actuator A
The CT2 second sleeve S2 is actuated to connect the second speed clutch gear G ₂ a second hub H2 Step 5
If the answer is NO in step 503, the process proceeds to step 505 to determine whether or not the gear is the second gear. If the result is YES, the process proceeds to step 506.
The sleeve actuator ACT1 is operated so that the first sleeve S1 connects the first speed clutch gear G ₁ and the first hub H1 and the process proceeds to step 512 to return. If NO in step 505, the process proceeds to step 507 and the gear stage. Is the fourth gear, and if YES, the routine proceeds to step 508, where the first sleeve actuator AC
Step T51 is operated so that the first sleeve S1 connects the third speed clutch gear G ₃ and the first hub H1.
Go to 2 and return.

On the other hand, if NO in step 502, that is, if it is determined to be in the third gear, the routine proceeds to step 509, where the current operating state is the region where preselection should be executed from the map shown in FIG. Is determined. As a result, if YES, the routine proceeds to step 510, where the second sleeve actuator ACT2 is set to the second sleeve S.
2 operates so as to connect the second speed clutch gear G ₂ and the second hub H2 and proceeds to step 512 to return. If NO in step 509, proceeds to step 511 to move the second sleeve S2 to the intermediate position. It operates as described above, and the process proceeds to step 512 and returns.

In the first embodiment, since the control is performed as described above, at the third speed, for example, A in FIG.
When driving at a point, the engine speed is inevitably low, and quick gear shifting is not required, so preselection is not performed, and the area where rattle noise is generated is reduced accordingly. On the other hand, when the vehicle is operating at point B in FIG. 4, the engine speed is high and the output is quite high even though the throttle opening is relatively small, so sudden acceleration may be required from this state. The preselection as described above is performed so that the speed can be changed quickly.

In the first embodiment described above, whether or not the current operating state is the third gear is used as the determination of the operating state in which a gear tooth rattling noise with a high level is generated when preselection is performed. Although the judgment is made based on the above, it is also possible to judge whether or not the operating state is such that a gear rattling noise with a large level is generated for each speed stage (excluding reverse speed stage), and the following modified examples are also possible. Is. That is, FIG.
Engine speed NE and throttle opening TA as shown in
Remember the map showing the area where the level of rattle sound is small and acceptable and the area where the level of rattle sound is large and unacceptable, and do not preselect when it is in the area where the level of rattle sound is unacceptable. Alternatively, pre-selection may be performed when the level of rattling noise is low and within an acceptable range, or as shown in FIG. 7, the engine speed NE and the throttle opening TA may be set in advance in advance. It is possible to store a map in which a region to be preselected and a region not to be preselected are stored and to be divided based on the division, or to be divided only based on the magnitude of the engine speed NE.

FIG. 8 is a flowchart of the second embodiment. In the second embodiment, the map shown in FIG. 6 is used as a modification of the first embodiment to determine whether to execute preselection, that is, the engine speed NE and throttle opening. If the map shows the region where the level of rattle sound against TA is small and the region where the level of rattle sound is large and the region where the rattle sound is large is unacceptable, and when there is a large demand for sudden acceleration with downshift,
Alternatively, even if the execution of preselection is prohibited, if the previous rattling sound level is too large to be acceptable, execute preselection and downshift,
The number of rotations is increased to reduce the rattling noise.

In FIG. 8, in step 801, the current gear GN is calculated from the signal from the gear sensor 111.
The throttle opening TA is read from the signal from the throttle opening sensor 113, and the engine speed NE is read from the signal from the engine speed sensor 114. In step 802, it is determined whether the rattling noise is at an acceptable level. If YES, that is, if it is determined that the rattling sound is small and is at an acceptable level, the same steps as steps 503 to 508 in the first embodiment are executed in steps 803 to 808, and the process proceeds to step 811. Since step 811 is a step of determining whether or not the flag for executing the downshift described later is 1, the gear rattling noise is at an acceptable level and step 80
If it has proceeded from 3 to 808, since it is NO, it proceeds directly to step 818 and returns.

On the other hand, if NO in step 802, that is, if the rattling noise is determined to be a large and unacceptable level, the process proceeds to step 809 to determine whether or not to downshift, that is, using the same map as in FIG. Whether the driving condition is such that there is a great demand for sudden acceleration accompanied by a shift, or even if the execution of preselection is prohibited using the map similar to that in FIG. 6, the level of rattling noise is still unacceptable. Determine if it is in a state. As a result, YES, that is, if it is determined that the downshift should be performed, the process proceeds to step 810, the flag FDS for executing the downshift is set to FDS = 1, and the following steps 803 to 808 are performed and the process proceeds to step 811. Since FDS = 1, the routine proceeds to step 812, where the downshift is executed, and at step 813 the flag F
After clearing DS, the process proceeds to step 818 and returns. If NO in step 809, that is, if it is not determined that the downshift should be performed, steps similar to step 511 of the first embodiment are executed in steps 814 to 817, and the process proceeds to step 818 and returns.

FIG. 9 is a flow chart of the third embodiment. In the third embodiment, the preselection is executed, and at the same time as the map shown in FIG. 6, that is, when the preselection is executed for the engine speed NE and the throttle opening TA, the rattling noise is generated. Is stored in advance in the ROM 105, indicating a region in which the level of the tooth mark is acceptable and a region in which the level of the rattling noise is large is unacceptable. The other clutch is weakly engaged and dragged to apply a load to the gears that have been rotated with no load to eliminate rattling between tooth flanks and suppress rattling noise. In step 901, the current gear stage GN is determined from the signal from the gear stage sensor 111 and the throttle opening sensor 1
The throttle opening TA is read from the signal from 13 and the engine speed NE is read from the signal from the engine speed sensor 114, preselection is executed in step 902, and whether or not the rattling sound is at an acceptable level in step 903. The judgment is made.

As a result, if NO, that is, if it is determined that the rattling noise is large and unacceptable, the routine proceeds to step 904, where it is determined whether the gear is the first speed or the third speed. If YES, the process proceeds to step 905, the second clutch supply hydraulic control valve VC2 is controlled so that the second clutch C2 is weakly engaged, and the process proceeds to step 908 to return. If NO at step 904, the routine proceeds to step 906, where it is determined whether the gear stage is the second gear stage or the fourth gear stage, and if YES, the routine proceeds to step 907 so that the first clutch C1 is weakly engaged. The first clutch supply hydraulic control valve VC1 is controlled and the process proceeds to step 908 and returns.
Fly to 8 and return.

The third embodiment can be used in combination with the first embodiment shown in FIG. 5 or the second embodiment shown in FIG. 8, for example, the first embodiment. In step 509, when it is determined that pre-selection should be executed because the current driving condition has a large demand for sudden acceleration accompanied by a downshift, the pre-selection is performed in step 510 with emphasis on the demand for rapid acceleration. Since it is executed, it is impossible to obtain the gear tooth rattling noise reduction effect. However, when the preselection is executed in step 510, the control shown in the third embodiment is also used,
That is, the second clutch C2 may be weakly engaged, and by doing so, gear rattle noise can be reduced while emphasizing the demand for sudden acceleration. In addition, in the second embodiment, when it is determined in step 809 that the current operating state has a large demand for sudden acceleration accompanied by a downshift, the downshift is executed to reduce gear rattle noise. However, the clutch may be weakly engaged instead of performing the downshift.

FIG. 10 shows a third embodiment of the second embodiment.
It is a flow chart of a fourth embodiment in which the above embodiments are combined, and hereinafter, only different parts from the second embodiment will be described. If it is determined in step 1002 that the level of gear rattle noise when preselection is executed is unacceptable, it is determined in step 1009 whether or not the current operating state is a state in which a sudden acceleration request is highly likely. To be done. As a result, if YES, in step 1010, the weakly engaging flag FJK = 1 is set, and then preselection is executed, and steps 1011 to 10 are executed.
If NO in step 1016, the flag FJK = 0 is set in step 1016. In step 1011, it is determined whether or not the flag FJK is 1, and if YES is determined, the process proceeds to step 1012, and it is determined whether the gear is the first speed or the third speed. , YE
If it is S, the process proceeds to step 1013, the second clutch is weakly engaged, and the process proceeds to step 1021 to return. If NO in step 1012, the process proceeds to step 1014, it is determined whether the gear is the second speed or the fourth speed, and if YES, the process proceeds to step 1015 and the first clutch is weakly engaged, and the step 1021 is performed. If the answer is NO, the process directly jumps to step 1021 to return.

Next, a fifth embodiment will be described.
In the fifth embodiment, a lockup area map as shown in FIG. 11 is separately stored in the ROM 105 to control the lockup of the torque converter, and it is determined from this map that the lockup area is the lockup area. Even in the case, when it is determined that a large level gear rattling noise is generated when the preselection is executed from the throttle opening degree and the engine speed NE, the lockup clutch 23 of the torque converter 2 is released or half-engaged. In this state, transmission of torque fluctuation of the engine is suppressed. Therefore, the map shown in FIG.
It is stored in M105. In this map, the lockup clutch 23 of the torque converter 2 is completely disengaged in a region where a rattling noise is generated and the level thereof is large, the lockup clutch 23 is completely engaged in a region where it is not generated, and the lockup clutch 23 is slipped in an intermediate region. It is a thing. By doing so, it is possible to prevent the torque fluctuation of the engine from being transmitted to the gear by releasing or sliding the lockup clutch 23 in the region where the rattling noise is generated, and the rattling noise is reduced.

However, in the fifth embodiment, the lockup clutch is set in the lockup region (from the throttle opening TA and the transmission output shaft rotation speed NT) where gear rattle noise is generated. The method of releasing or slipping the gears to deal with the power loss is larger, or the method not used for power transmission of the twin clutch type automatic transmission 3 at present is the same as in the fourth embodiment. The method of dealing with the clutch by weakly engaging is compared to see if the loss is larger, and the method of dealing with the less loss is dealt with.

FIG. 13 is a flow chart of the fifth embodiment for performing the above-mentioned control. Since this is control relating to the lock-up region, control cannot be performed in the entire operating range, so other For example, it is used in combination with the flowchart of the fourth embodiment. In this case, the step 13 between the steps 1011 and 1012 of the flowchart of the fourth embodiment of FIG.
01 to 1309 are arranged. Step 1 of FIG.
When it is determined in 011 that the flag FJK is 1,
Proceeding to step 1301, in step 1301 it is determined from the map of FIG. 11 described above whether or not it is in the lockup area. If the result is NO, that is, if it is not in the lockup region, the process jumps to step 1012 to weakly engage the clutch to reduce the gear rattle noise, and if YES, the process proceeds to step 1302. In step 1302, it is determined from the above-described map of FIG. 12 whether or not the vehicle is in the first slip region. If YES, step 13
03, the power loss Q when the lockup clutch is slipped in step 1304 described later.
_It is determined whether _LU is smaller than the power loss Q _CL when the clutch is weakly engaged. As a result, if YES, in step 1305, the first difference Δ in which the output speed of the torque converter 2 is predetermined with respect to the input speed.
N, for example, the lockup hydraulic control valve VL is controlled so as to be reduced by 50 revolutions, and if NO, step 10
Proceed to step 12 to engage the clutch weakly.

Thereafter, if NO in step 1302, it is determined in step 1305 whether or not the vehicle is in the second slip region. If YES is determined, the operation proceeds to step 1306, and if NO is determined. Step 1 assuming that it is in the lockup OFF area
Proceed to 308. In steps 1306 and 1308, similarly to step 1303, whether the power loss Q _LU when the lock-up clutch is slipped or released is smaller than the power loss Q _CL when the clutch is weakly engaged. Step 130
If YES in step 6, control is performed in step 1307 so that the output rotation speed of the torque converter 2 decreases by a predetermined second difference ΔN with respect to the input rotation speed, for example, 150 rotations, or step 1308. If YES is determined in step 1309, the lockup clutch is controlled to be completely released in step 1309, and if NO in step 1306 or step 1308, the process proceeds to step 1012 and the clutch is weakly engaged.

In the above-described first to fifth embodiments, the operating state in which the gear tooth rattling noise of a large level is generated when the preselection is executed is judged from the gear position, the throttle opening and the engine speed. However, it is also possible to determine the operating state in which the gear rattle noise having a large level is generated by detecting the rattle noise itself. The sixth embodiment described below is an example thereof. The sixth embodiment is a modification of the third embodiment, in which a gear rattle sound sensor that generates a gear rattle sound signal according to the magnitude of the rattle sound similar to that of an engine knock sensor ( (Details are omitted) is provided, and the degree of engagement of the clutch is changed according to the level of the signal.

FIG. 14 is a flowchart of the control of the sixth embodiment. The gear stage GN, the throttle opening TA, and the engine speed NE read in the third embodiment.
In addition, the output signal FN of the rattle noise sensor is read (step 1401), and then, if the current gear number is the first speed or the third speed, the second speed or the fourth speed, respectively. Is determined as to whether the level of the output signal FN of the rattle noise sensor is smaller than the first determination condition FN1 that is the lowest (step 1403 for the first speed or the third speed, the second speed or the fourth speed). 1410) in the case of high speed,
If YES, do nothing and return as it is, NO
If it is, it is further determined whether it is between the first determination condition FN1 and the second determination condition FN2 that is the next largest (steps 1404 and 1411). If YES, the twin clutch transmission is currently engaged. The non-engaged clutch is set to the first stage weak engagement (steps 1406 and 1413),
In the case of NO, it is further determined whether or not it is between the third determination condition FN3 which is larger than the second determination condition FN2 (steps 1405 and 1412). The second-stage weak engagement that is stronger than the second-stage weak engagement (steps 1407 and 1414), and the third-stage weak engagement that is stronger than the second-stage weak engagement if the third determination condition FN3 is greater (step 1407, 1414). 1408, 141
5) Things.

[0073]

According to the present invention, it is possible to reduce or prevent the rattling noise generated by preselection in a twin clutch type automatic transmission, and the quietness of the vehicle is improved. In particular, according to the first and second aspects, the preselection is not executed in the region where the high level gear rattle noise is generated, so that the generation of the high level gear rattle noise is prevented. Particularly, according to the second aspect. It is preselected in the range where rapid acceleration is required, so drivability is not compromised. Particularly, according to the third and fourth aspects, the downshift is executed, the engine speed increases, and the torque fluctuation decreases, so that the level of rattling noise decreases. In particular, according to claims 5, 6, and 7, when the preselection is being performed, the clutch not used for achieving the current gear is weakly engaged, so that the preselection is performed. However, the rattling noise is prevented from being generated, and particularly, the range of weak engagement is limited according to claims 6 and 7, so that the level is effectively large and the tooth striking is uncomfortable while suppressing the decrease in fuel consumption. It is possible to prevent the generation of sound. Particularly, according to claims 8 and 9, the occurrence of rattling noise can be suppressed in the lockup region by adjusting the degree of engagement of the lockup clutch. For example, the efficiency when the clutch that is not used to achieve the gear is weakly engaged is compared with the efficiency when the lockup clutch is released, and the more efficient operation is performed. Since it is executed, the rattling noise can be reduced while suppressing the reduction in efficiency, and the reduction in fuel consumption can be suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a twin clutch type transmission according to the present invention.

FIG. 2 is a combination table of operations of respective elements for achieving respective shift speeds.

FIG. 3 is a diagram showing a connected state of each element in each gear.

FIG. 4 is a map showing a downshift line and a preselect region with respect to a throttle opening degree of a third speed and a transmission output shaft speed.

FIG. 5 is a flowchart of a preselect control according to the first embodiment.

FIG. 6 is a map showing the generation region of rattling noise with respect to the throttle opening and engine speed at a certain speed stage.

FIG. 7 is a map showing a preselect region with respect to a throttle opening and an engine speed at a certain speed stage.

FIG. 8 is a flowchart of control according to the second embodiment.

FIG. 9 is a flowchart of control according to the third embodiment.

FIG. 10 is a flowchart of control according to the fourth embodiment.

FIG. 11 is a control map of lockup of the torque converter with respect to throttle opening and transmission output shaft speed.

FIG. 12 is a map of lock-up clutch control with respect to engine speed and throttle opening at a certain speed stage.

FIG. 13 is a flowchart of control according to the fifth embodiment.

FIG. 14 is a flowchart of control according to the sixth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Torque converter 3 ... Twin clutch type automatic transmission 10 ... Engine output shaft 30 ... (Transmission) input shaft 40 ... First clutch output shaft 50 ... Second clutch output shaft 60 ... Secondary shaft 70 ... machine) output shaft 100 ... electronic control unit C1 ... first clutch C2 ... second clutch C1 _i, C2 _i ... first, second clutch input disk C1 _o, C2 _o ... first, second clutch output disk I _1, I ₂ , I ₃ , I ₄ , I _R ... 1st, _2nd , _3rd , _4th speed,
Reverse drive gear _{O 1, O 2, O 3} , O 4, O R ... first, second speed,
Reverse driven gear I _s ... countershaft drive gear O _s ... countershaft driven gear M _R ... reverse idle gear _{G 1, G 2, G 3} , G 4, G R ... first, second speed,
Reverse clutch gear H1, H2, H3 ... 1st, 2nd, 3rd hub Y1, Y2, Y3 ... 1st, 2nd, 3rd shift fork S1, S2, S3 ... 1st, 2nd, 3rd sleeve ACT1, ACT2, ACT3 ... 1, 2, 3 sleeve actuator VC1, VC2 ... 1st and 2nd clutch supply hydraulic control valve VL ... Lock-up clutch supply hydraulic control valve

Claims (9)

[Claims] 1. A plurality of clutches connected to a transmission input shaft, and a plurality of gear trains for selectively connecting between a clutch output shaft of these clutches and a transmission output shaft by a selection operation of a gear selection device. By engaging one clutch and releasing the other clutch, and by connecting the clutch output shaft of the one clutch and the transmission output shaft via a gear train, a desired gear stage is achieved. Type automatic transmission for a vehicle, wherein a clutch which is not currently used for achieving a gear stage is operated by operating a predetermined gear selecting device while achieving a certain gear stage. Has a preselection unit for executing a preselection in which the clutch output shaft and the transmission output shaft of the vehicle are connected through a predetermined gear train to make them stand by, and a driving condition detection for detecting a driving condition of the vehicle is performed. If a stage, the current operating state, executing the preselect,
A determination means for determining whether an operating state in which a gear tooth rattling noise with a high level is generated or an operating state in which a gear tooth rattling noise with a low level is generated is provided, and the current operating state is when the preselection is executed. A shift control device, wherein the preselection means prohibits execution of preselection when it is determined that an operating state in which a gear tooth rattling noise of a high level is generated. 2. A determination means for determining whether an operating state in which there is a great demand for sudden acceleration accompanied by a downshift or an operating state in which there is almost no demand for sudden acceleration accompanied by a downshift is provided, and the present operating state is In the operating state where gear rattle noise of a large level gear is generated when the preselection is executed,
The shift control according to claim 1, wherein when it is determined that the operating state is such that there is almost no demand for sudden acceleration accompanied by a downshift, the preselection unit prohibits execution of preselection. apparatus. 3. Further, downshift means for selectively executing downshift is provided, and when the current operating state is an operating state in which a gear tooth rattling noise of a large level is generated when the preselection is performed, the downshift is performed. 3. The shift control device according to claim 2, wherein the downshift unit executes a downshift when it is determined that the driving state is in a state in which a demand for sudden acceleration accompanied by a shift is highly likely. 4. When the current operating state prohibits the execution of the preselection, a gear tooth rattling noise with a high level is generated or a gear tooth rattling noise with a low level is generated. A gear tooth having a large level is provided even if the current operating state prohibits the execution of the preselection, provided with means for determining whether or not the operating state is present and downshift means for selectively performing the downshift. The shift control device according to claim 1 or 2, wherein the downshift means performs a downshift when it is determined that the driving state is such that a striking sound is generated. 5. A plurality of clutches connected to a transmission input shaft, and a plurality of gear trains for selectively connecting between a clutch output shaft of these clutches and a transmission output shaft by a selection operation of a gear selection device. By engaging one clutch and releasing the other clutch, and by connecting the clutch output shaft of the one clutch and the transmission output shaft via a gear train, a desired gear stage is achieved. Type automatic transmission for a vehicle, wherein a clutch which is not currently used for achieving a gear stage is operated by operating a predetermined gear selecting device while achieving a certain gear stage. It has preselection means for executing a preselection in which the clutch output shaft and the transmission output shaft of the transmission are connected through a predetermined gear train to make them stand by, and is currently used for achieving a gear stage. A shift control characterized by comprising weak engagement means for selectively weakly engaging one of the clutches, wherein the weak engagement means performs weak engagement when the preselection means performs the preselection. apparatus. 6. A driving state detecting means for detecting a driving state of a vehicle, and a current driving state is a driving state in which a gear tooth rattling noise having a large level is generated when the preselection is executed, or a level And a determining means for determining whether an operating state in which a small gear rattle is generated, and it is determined that the current operating state is an operating state in which a small gear rattle is generated when the preselection is executed. The gear shift control device according to claim 5, wherein the weak engagement means prohibits the weak engagement from being performed. 7. A weak engagement means for weakly engaging a clutch that is not used to achieve a current gear position, wherein the current operating state is a level when the preselection is executed. When it is determined that there is a strong demand for sudden acceleration accompanied by a downshift in an operating state in which a large gear rattle noise is generated, the weak engagement means performs weak engagement. The shift control device according to claim 2. 8. The transmission input shaft is further coupled with a torque converter having a lock-up clutch that can be connected and disconnected, and weakly engages a clutch that is not used to achieve a current gear position. With weak engagement means, the current operating state is an operating state in which a gear tooth rattling noise of a high level is generated when the preselection is performed, and there is a possibility that there is a great demand for sudden acceleration accompanied by a downshift. 3. The gear shift control device according to claim 2, wherein when the determination is made, the weak engagement means performs weak engagement or releases the lockup clutch. 9. The power loss when the weak engagement means is operated is compared with the power loss when the lockup clutch is released, and the operation with the smaller power loss is performed. The shift control device according to claim 8.