JP2000274446A - Dog clutch mechanism and automatic transmission using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dog clutch mechanism having a simple structure and capable of shortening an axial dimension. SOLUTION: A dog clutch mechanism is provided with a hub 40 integrally rotated with a shaft 6, a gear rotatably supported on the shaft and having an outer spline in an end part opposite the hub 40, and a sleeve 41 engaged with the hub 40 so as to be axially moved and having an inner spline 41a in an inner peripheral part so as to be engaged with the outer spline. A plurality of guide pawls 40b are projectingly provided in the outer peripheral part of the hub 40 so as to be axially extended along the outer peripheral side of the outer spline of the gear, and a guide groove 41c is formed in the inner peripheral part of the sleeve 41 so as to be engaged with the guide pawl so as to axially slide. When the sleeve 41 is axially shifted, the inner spline of the sleeve 41 is engaged only with the outer spline of the gear, and thereby the axial dimension of the sleeve 41 is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dog clutch mechanism and an automatic transmission using the dog clutch mechanism.

[0002]

2. Description of the Related Art An automatic transmission generally includes a planetary gear mechanism and a plurality of friction engagement elements (a hydraulic clutch and a hydraulic brake). Gear speed.
By the way, in addition to the automatic transmission using such a planetary gear mechanism and the friction engagement element, a manual transmission is used, and switching of each gear is automatically performed using an electric or hydraulic actuator. Automatic transmissions are known. That is, this transmission is called an automatic manual transmission, and a clutch provided between the output shaft of the engine and the input shaft of the transmission to connect and disconnect the driving force, and a clutch between the input shaft and the output shaft. A plurality of transmission gear pairs, a plurality of synchronizers for selectively connecting each transmission gear pair to an input shaft or an output shaft to establish a desired gear position, and a transmission for switching and driving each synchronizer. An actuator, a clutch actuator for connecting and disconnecting the clutch, and a controller for controlling the shift actuator and the clutch actuator in accordance with the running state of the vehicle are provided.

As described above, also in the case of an automatic manual transmission, a synchronizing device is used as a gear shift device, as in a normal manual transmission. The synchronizer has a function of reducing the difference in rotational speed between the two members,
In addition to the outer spline, hub, and sleeve integrally formed with the transmission gear, a number of parts such as a synchronizer ring, a key, and a key spring are required, and there is a problem that an axial space is increased.

On the other hand, in the case of the automatic transmission as described above, the rotational speed ratio between the input shaft and the output shaft can be controlled relatively freely by controlling the engine speed or controlling the clutch. Therefore, if the rotation of the input shaft is controlled such that the rotation speed ratio between the input shaft and the output shaft approaches the speed ratio corresponding to the target shift speed at the time of switching the gear, the synchronization device is not necessarily required. That is, it is possible to use a dog clutch mechanism having a simple structure instead of the synchronization device.

[0005]

FIG. 1 shows an example of a dog clutch mechanism. A first transmission gear 51 and a second transmission gear 52 are rotatably supported on a shaft 50, and a hub 53 is interposed therebetween. Are spline-fitted. Therefore, the hub 53 rotates integrally with the shaft 50. The transmission gears 51 and 52 are provided with outer splines 51 a and 52 a at opposing portions, respectively.
a is formed. And the spline 5 of the hub 53
By shifting the sleeve 54 fitted in the shaft 3a in the axial direction, the sleeve 54 is connected to the spline 53a of the hub 53 and the outer splines 51a, 52 of one of the transmission gears 51, 52.
a, the shaft 50 and one of the transmission gears 51 and 52 are connected (FIG. 1).
Is indicated by a two-dot chain line).

However, the dog clutch mechanism has a structure in which power is transmitted by the sleeve 54 straddling between the spline 53a of the hub 53 and the outer splines 51a, 52a of one of the transmission gears 51, 52. Therefore, there is a disadvantage that the length L of the sleeve 54 is increased, and the axial length of the hub 53 is correspondingly increased. Therefore, it is not so effective in reducing the axial dimension.

Therefore, an object of the present invention is to provide a simple structure,
An object of the present invention is to provide a dog clutch mechanism capable of reducing the axial dimension. Another object is to provide an automatic transmission that is compact in the axial direction by using the dog clutch mechanism.

[0008]

The above object is achieved by the present invention. That is, a hub that rotates integrally with the shaft, a rotator that is rotatably supported on the shaft and has an outer spline at an end facing the hub, and movably engages the hub in the axial direction, A dog clutch mechanism that selectively connects the hub and the rotating body by shifting the sleeve in the axial direction, the sleeve including an inner spline that can be engaged with the outer spline of the rotating body. A plurality of guide claws extending in the axial direction along the outer peripheral side of the outer spline of the rotating body are protruded from the outer peripheral portion, and the inner peripheral portion of the sleeve is slidably engaged with the guide claws in the axial direction. A dog clutch mechanism is provided in which a guide groove is formed so that when the sleeve is shifted in the axial direction, the inner spline of the sleeve engages only with the outer spline of the rotating body. .

In the neutral state, the sleeve is located at the center of the hub and engages the guide pawl. Here, when the sleeve is shifted in the axial direction, the sleeve is guided by the guide claws, and the inner spline of the sleeve meshes with the outer spline of the rotating body. Then, when the inner spline of the sleeve is shifted until it completely engages with the outer spline of the rotating body, the inner spline of the sleeve engages only with the outer spline of the rotating body, and a position displaced in the axial direction with respect to the hub. Become. That is, unlike the conventional dog clutch, the inner spline of the sleeve does not need to be spline-fitted over the hub and the rotating body. In this state, if the rotating body is on the input side, power is transmitted to the rotating body, the outer spline, the sleeve, the guide pawl, the hub, and the shaft. As described above, when the sleeve is shifted, the inner spline of the sleeve does not need to straddle the hub and the outer spline of the rotating body, so the axial length of the sleeve is set to the minimum length necessary for torque transmission. It can be shortened, and the length of the hub can be shortened. as a result,
The axial dimension of the dog clutch mechanism can be reduced.

According to the present invention, the chamfer is provided only at the side opposite to the side where the inner spline of the sleeve and the outer spline of the rotary body abut against each other due to the rotational speed difference between the sleeve and the rotary body. It is. In this way, even if there is a slight difference in rotational speed between the sleeve and the rotating body, when the inner spline and the outer spline collide, they will not be dislodged by the chamfer and will engage smoothly. Can be. Therefore, synchronous rotation control between the sleeve (shaft) and the rotating body is simplified, and poor spline insertion and generation of abnormal noise can be prevented.

According to a third aspect, the dog clutch mechanism according to the first or second aspect is applied to an automatic manual transmission. That is, a plurality of transmission gear pairs disposed between the input shaft and the output shaft, and a plurality of switching devices for selectively connecting each transmission gear pair to the input shaft or the output shaft to establish a desired gear position. An automatic transmission comprising: a shift actuator for switchingly driving each switching device; and a controller for controlling the shift actuator in accordance with a running state of the vehicle, wherein at least one of the switching devices is at least one of:
Or means for controlling the rotation of the input shaft such that the rotation speed ratio between the input shaft and the output shaft approaches a speed ratio corresponding to a desired gear when the gear is switched. Is provided in the automatic transmission. In this case, the size of each switching device in the axial direction can be reduced, so that a small and compact automatic transmission can be realized. As means for controlling the rotation of the input shaft,
The engine speed may be controlled, or slip control of the clutch may be performed. Further, an auxiliary motor may be provided on the input shaft, and rotation of the input shaft may be controlled by rotation of the motor.

In the present invention, the rotating body is not limited to the transmission gear, but may be a pulley, a sprocket, a rotating shaft, or the like. Therefore, the dog clutch mechanism of the present invention can be used not only for the shift stage switching device but also for various applications such as a two-wheel / four-wheel switching device for transfer and a high / low speed switching device.

When the rotating bodies are provided on both sides of the hub, the guide claws of the hub need to protrude in both directions, but the rotating bodies are provided only on one side of the hub. In this case, the guide claws need only protrude to one side.

[0014]

FIG. 1 shows a schematic structure of an example of an automatic manual transmission using a dog clutch mechanism according to the present invention. The output shaft 2 of the engine 1 is connected to the input shaft 6 of the transmission 4 via the dry clutch 3. The transmission 4 of this embodiment is a five-speed specification FF horizontal manual transmission. An input shaft 6 and an output shaft 7 are supported inside the housing 5 of the transmission 4 in parallel with the vehicle width direction.
A first gear 8, a second gear 9, and a reverse gear 10 are fixed to a starting end (engine side) of the input shaft 6, and a third gear 11, a fourth gear 12, and 5 are provided to an end of the input shaft 6. The speed gear 13 is rotatably supported in order. 3rd gear 11 and 4
The speed gear 12 is controlled by the switching device 14 for 3-4 speed to input shaft 6.
And the fifth speed gear 13 is selectively connected to the input shaft 6 by a fifth speed switching device 15.

An output gear 16 is fixed to the starting end of the output shaft 7. First gears 17 and 2 adjacent to output gear 16
A speed gear 18 is rotatably supported on the output shaft 7, and these gears 17 and 18 are selectively connected to the output shaft 7 by a 1-2 speed switching device 19. The first gear 17 is the input shaft 6
The first gear 8 is always meshed with the second gear 9 on the input shaft 6. Switching device 19
Is provided integrally with a reversing gear 20, which can mesh with the reversing gear 10 of the input shaft 6 via an idler gear 21. On the rear side of the output shaft 7, the third speed gear 11, the fourth speed gears 12 and 5 on the input shaft 6 are provided.
3rd speed gear 22, 4th speed gear 23 meshing with the speed gear 13 respectively
And the fifth speed gear 24 are fixed. The output gear 16 of the output shaft 7 is the ring gear 2 of the differential device 25.
6, and the driving force is distributed to the left and right drive shafts 27, 28.

The clutch 3 and the switching devices 14, 1
5 and 19 are driven by a clutch actuator 30 and a shift actuator 31 to 33, respectively.
4 is controlled according to the running state of the vehicle. That is, the controller 34 stores in advance programs (shift map and clutch control map) corresponding to the running state, and includes running conditions such as engine speed, vehicle speed, throttle opening, running range, and input / output shaft speed. The clutch 3 and the switching devices 14, 15, and 19 are driven so that an appropriate state is selected in accordance with the condition.
Since such control is known per se, a detailed description thereof will be omitted. The actuators 30 to 33 may be hydraulic actuators or electric actuators such as step motors.

The switching devices 14, 15, 16 are formed by a dog clutch mechanism. 3 and 4 show the switching device 1.
4 shows a detailed structure. The switching device 14 including a dog clutch mechanism includes a hub 40 that is spline-fitted to the input shaft 6 by the internal spline 40a and that rotates integrally with the input shaft 6. The hub 40 includes the third gear 11 and the fourth gear 12
It is located between. Outer splines 11a and 12a are integrally formed at opposite ends of the third speed gear 11 and the fourth speed gear 12. A sleeve 41 is engaged with the hub 40 so as to be movable in the axial direction with respect to the hub 40.
Is provided on the inner peripheral portion of the sleeve 41.
An inner spline 41a that can be engaged with the outer splines 11a and 12a of the first and fourth speed gears 12 is provided. A peripheral groove 41b is formed in the outer peripheral portion of the sleeve 41 to engage with the fork of the speed change actuator 31.

The outer periphery of the hub 40 is not provided with a conventional outer spline, and a plurality of (here, three) guide claws 40b are projected instead of the spline. These guide claws 40b extend in the axial direction so as to overhang on the outer peripheral side of the outer splines 11a and 12a of the third speed gear 11 and the fourth speed gear 12. A guide groove 41c is formed in the inner peripheral portion of the sleeve 41 so as to slidably engage with the guide claw 40b in the axial direction.
The axial dimension L of the sleeve 41 is
When the shaft is shifted in the axial direction, the inner spline 41a of the sleeve 41 is set to a size that engages with only one of the outer splines 11a and 12a.

In the case of the dog clutch mechanism, unlike the synchronizer, if there is a rotational speed difference between the sleeve 41 and the gears 11 and 12, smooth engagement cannot be achieved. Therefore, in this embodiment, the following two measures are taken for smooth engagement. As shown in FIG. 5A, the first means is to provide chamfers 41d only on the rotation direction side at both axial ends of the inner splines 41a of the sleeve 41, and to provide the outer splines 11a and 12a of the gears 11 and 12 with the chamfers 41d. The point is that the chamfer 11b (the outer spline 12a of the gear 12 is not shown) is formed only on the side opposite to the rotation direction. The second means is to adjust the speed so that the rotation speed Vg of the third speed gear 11 is slightly higher than the rotation speed Vs of the sleeve 41,
The point is that 1 is shifted.

That is, if the sleeve 41 is shifted in a state where the rotation speed Vg of the gear 11 is lower than the rotation speed Vs of the sleeve 41, the chamfers 41d and 11b collide with each other, and the spline is rejected, thereby causing poor gear engagement or abnormal noise. Occurs. On the other hand, if the sleeve 41 is shifted in a state where the rotation speed Vg of the gear 11 is controlled so as to be slightly higher than the rotation speed Vs of the sleeve 41, FIG.
As shown in (b) to (c) of FIG.
The plane on the side opposite to b abuts and can be easily engaged.

The rotation speed of the gears 11 and 12 and the sleeve 41 can be controlled by controlling the rotation speed of the input shaft 6. The rotation of the input shaft 6 can be controlled by, for example, engine speed control or slip control of the clutch 3. In addition, an auxiliary motor is provided on the input shaft 6, and the rotation of the motor controls the rotation speed of the input shaft 6. Can also be performed. In any case, since strict rotation control is not required, implementation is easy.

Here, the operation of the switching device 14, in particular, 3
The switching operation from the fourth speed to the fourth speed will be described. As shown by the two-dot chain line in FIG. 3, when it is necessary to shift to the fourth speed while traveling in the third speed, the engine torque is first reduced and the engine torque is transmitted to the third speed gears 11 and 22. Decrease torque. Then, the sleeve 41 is actuated by the actuator 31.
Is shifted to the left in FIG. 3 to be in a neutral state shown by a solid line in FIG. Here, the rotation speed of the input shaft 6 is controlled by engine speed control or clutch slip control so that Vg> Vs, and the sleeve 41 is shifted in the fourth speed direction (leftward in FIG. 3) by the actuator 31. At this time, the sleeve 41 is guided by the guide claw 40b and the guide groove 41c, and moves in the axial direction. Then, the shift ends when the sleeve 41 is disengaged from the outer peripheral portion of the hub 40 and the inner spline 41a is shifted to a position where it meshes with the outer spline 12a of the fourth speed gear 12. In this state, the inner spline 41a of the sleeve 41 meshes with only the outer spline 12a of the fourth speed gear 12. Therefore, the driving force of the input shaft 6 varies from the hub 40 to the guide claws 40b to
The power is transmitted to the sleeve 41 to the outer spline 12a to the fourth speed gear 12, and the fourth speed state is established. The sleeve 41 is shown in FIG.
Shifts rightward (when shifting from 4th to 3rd)
Is also the same as above, and the description is omitted.

By the way, an auxiliary motor is provided on the input shaft 6,
When the rotation speed of the input shaft 6 is controlled by the rotation of the motor at the time of gear shifting, the following may be performed. That is, once the clutch 3 is released, the sleeve 41 is shifted to the neutral position, the auxiliary motor is rotated and adjusted so that Vg> Vs, and then the sleeve 41 is engaged with the outer spline of the desired gear. Then clutch 3
Should be concluded.

In FIGS. 3 and 4, the dog clutch mechanism is
Although an example in which the present invention is applied to the four-speed switching device 14 has been described, a similar dog clutch mechanism can be applied to the fifth-speed switching device 15 and the 1-2-speed switching device 19. When the dog clutch mechanism is applied to the five-speed switching device 15, since the sleeve only needs to shift to one side, the guide claws of the hub need only protrude to one side. When the dog clutch mechanism is applied to the 1-2 speed switching device 19, it is necessary to integrally provide the sleeve with the reverse gear 20.

As described above, the sleeve 41 of the dog clutch mechanism is connected to the hub 40 and one of the outer splines 11a, 12a.
Therefore, the axial length L of the sleeve 41 can be reduced as compared with the conventional case (see FIG. 1), and the axial length of the hub 40 can be correspondingly reduced. . As a result, the axial length of the transmission equipped with the dog clutch mechanism can be reduced. In particular, as shown in FIG.
In the case of the F-transverse transmission, the axial dimension is severely restricted by the width of the engine room. For this reason, it is an important issue to reduce the axial dimension of the transmission as much as possible, but by configuring the switching device with a dog clutch mechanism as described above, it is possible to greatly reduce the axial direction. .

In the above-described embodiment, an example in which the dog clutch mechanism of the present invention is applied to a transmission mechanism of an automatic manual transmission has been described. However, it is needless to say that the dog clutch mechanism can be applied to all other power transmission mechanisms.

[0027]

As is apparent from the above description, claim 1
According to the invention described in (1), a plurality of guide claws are protruded on the outer peripheral portion of the hub of the dog clutch mechanism, and a guide groove is formed on the inner peripheral portion of the sleeve so as to slidably engage with the guide claws in the axial direction. When the sleeve is shifted in the axial direction, the inner spline of the sleeve engages only with the outer spline of the rotating body, so that the axial dimension of the sleeve can be shortened, and the dog having a shorter axial dimension than the conventional one can be used. A clutch mechanism can be realized. Further, by applying the dog clutch mechanism to an automatic manual transmission, it is possible to provide an automatic transmission that is compact in the axial direction and has a simple structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a general dog clutch mechanism.

FIG. 2 is a schematic diagram of an example of an automatic manual transmission using a dog clutch mechanism according to the present invention.

FIG. 3 is a sectional view of the 3-4 speed switching device of FIG. 2;

FIG. 4 is an exploded perspective view of a hub and a sleeve of the 3-4 speed switching device of FIG. 3;

FIG. 5 is a plan view showing an engagement operation between an inner spline of a sleeve and an outer spline of a gear.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 engine 3 clutch 4 transmission 6 input shaft 7 output shaft 14, 15, 19 switching device (dog clutch mechanism) 11, 12 gear (rotating body) 11a, 12a outer spline 30 clutch actuator 31-33 shift actuator 34 controller 40 hub 40b guide claw 41 sleeve 41a inner spline 41c guide groove

Claims (3)

[Claims] 1. A hub that rotates integrally with a shaft, a rotating body rotatably supported on the shaft and having an external spline at an end facing the hub, and movably engaged with the hub in the axial direction. ,
A dog clutch mechanism that selectively connects the hub and the rotating body by shifting the sleeve in the axial direction, comprising a sleeve having an inner spline that can be engaged with the outer spline of the rotating body on the inner peripheral portion; On the outer periphery of the hub,
A plurality of guide claws extend in the axial direction along the outer peripheral side of the outer spline of the rotating body, and a guide groove slidably engages with the guide claws in the inner peripheral portion of the sleeve in the axial direction. When formed, when the sleeve is shifted in the axial direction,
A dog clutch mechanism, wherein the inner spline of the sleeve is configured to engage only with the outer spline of the rotating body. 2. A chamfer is provided only at the opposite end of the inner spline of the sleeve and the outer spline of the rotator on the side opposite to the side where the sleeve and the rotator abut against each other due to the difference in rotational speed between the sleeve and the rotator. The dog clutch mechanism according to claim 1, wherein 3. A plurality of transmission gear pairs disposed between an input shaft and an output shaft, and a plurality of transmission gear pairs selectively connecting each transmission gear pair to an input shaft or an output shaft to establish a desired gear position. In an automatic transmission including a switching device, a shift actuator that switches and drives each switching device, and a controller that controls the shift actuator according to a traveling state of the vehicle,
At least one of the switching devices is constituted by the dog clutch mechanism according to claim 1 or 2, wherein a speed ratio between the input shaft and the output shaft corresponds to a desired speed when the speed is switched. An automatic transmission, comprising: means for controlling rotation of an input shaft so as to approach a speed ratio.