JPH04366068A - Automatic transmission controller for vehicle mounted with engine with supercharger - Google Patents

Abstract

PURPOSE:To prevent surely the unnecessary shift down of a shift ratio caused by turbo lag. CONSTITUTION:At the automatic transmission controller 62 of a vehicle mounted with an engine with an exhaust turbine supercharger, the 1st delaying means 63 that delays a shift ratio transfer time to shift down on the basis of turbo lag, is provided, and the delaying time of the 1st delaying means 63 is set the longer under an operation condition in which turbo lag is large.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an automatic transmission control device for a vehicle equipped with an engine equipped with an exhaust turbine supercharger.
In particular, the present invention relates to an automatic transmission control device that prevents unnecessary gear ratio downshifts.

0002

2. Description of the Related Art Automatic transmissions that electrically detect vehicle speed, throttle opening, and shift position and determine a speed change ratio (gear ratio) according to driving conditions have been known. In addition, the exhaust turbine supercharger (turbocharger) uses the energy of the exhaust gas to rotate the exhaust turbine and drive the coaxial compressor to rotate, thereby supplying the engine with high-density intake air at a pressure higher than atmospheric pressure. It is installed in many vehicles because it greatly contributes to improving the performance.

[0003] As a prior art related to a supercharged engine equipped with an automatic transmission, for example, Japanese Patent Application Laid-Open No. 2-259235
No. Publication is known. The device disclosed in this publication sets a switching line for the supercharging operation of two superchargers outside the range of changes in engine operating conditions caused by shift changes of an automatic transmission, and We are trying to suppress switching between machines.

0004

[Problems to be Solved by the Invention] As mentioned above, the gear ratio of an automatic transmission is usually determined based on the vehicle speed and throttle opening (
However, in the case of a vehicle equipped with an engine equipped with an exhaust turbine supercharger, if the shift control is performed solely based on the vehicle speed and throttle opening, the following problems will occur. For engines equipped with an exhaust turbine supercharger (turbocharger), there is a time required for boost pressure to rise to a predetermined value after pressing the accelerator pedal.
In other words, there is always turbo lag. Therefore, immediately after acceleration, the throttle opening becomes too large for the vehicle speed, which increases as the engine output torque increases.
A problem arises in which the gear ratio of the automatic transmission is downshifted. This problem occurs in both engines that have a single exhaust turbine supercharger and engines that have two main and secondary exhaust turbine superchargers. Unnecessary gear ratio downshifts due to turbo lag have a negative impact on drivability and fuel efficiency, and a solution to this problem is desired.

The present invention focuses on the above problem and provides an automatic transmission control device for a vehicle equipped with a supercharged engine that can reliably prevent unnecessary gear ratio downshifts caused by turbo lag. The purpose is to

[0006]

[Means for Solving the Problems] An automatic transmission control device for a vehicle equipped with a supercharged engine according to the present invention in accordance with this object is constructed as follows. (1) In an automatic transmission control device for a vehicle equipped with an engine equipped with an exhaust turbine supercharger, a first delay that causes the automatic transmission control device to delay the time to shift down the gear ratio based on turbo lag. A means is provided, and the delay time of the first delay means is set to be longer as the operating condition has a larger turbo lag. (2) An engine with an exhaust turbine supercharger that supercharges only the main turbocharger in the low intake air flow range, and supercharges both the main turbocharger and the auxiliary turbocharger in the high intake air flow range. In the automatic transmission control device for a vehicle equipped with the automatic transmission control device, the automatic transmission control device is provided with a second delay means for delaying the transition time to downshifting of the gear ratio based on turbo lag, and the second delay means is delayed. The time is set longer in the supercharging operating range of both the main turbocharger and the sub-turbocharger than in the supercharging operating range of only the main turbocharger.

[0007]

[Operations] The automatic transmission control system for a vehicle equipped with a supercharged engine configured as described above operates as follows. When acceleration is started by depressing the accelerator pedal, the first delay means delays the transition time to downshifting of the gear ratio. Therefore, even if the throttle opening degree is too large relative to the vehicle speed, the gear ratio is maintained as it is, and unnecessary downshifting of the gear ratio due to turbo lag is prevented.

In addition, in a supercharged engine that performs switching control between the main turbocharger and the auxiliary turbocharger based on the amount of intake air, it is more likely that both the main turbocharger and the auxiliary turbocharger will be activated than when only the main turbocharger is in operation. Turbo lag is greater when supercharging is activated. Therefore, by lengthening the transition time for downshifting the gear ratio using the second delay means when supercharging both turbochargers, unnecessary downshifting of the gear ratio can be prevented even if the throttle opening is large. be done.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an automatic transmission control system for a vehicle equipped with a supercharged engine according to the present invention will be described below with reference to the drawings.

First Embodiment FIGS. 1 to 9 show a first embodiment of the present invention.
In particular, it shows the case where it is applied to a 6-cylinder engine mounted on a vehicle. In FIG. 2, 1 is an engine, 2 is a surge tank, and 3 is an exhaust manifold. Exhaust manifold 3 connects #1 to #3 cylinder groups and #4 to #4 without exhaust interference.
Two #6 cylinder groups are assembled, and the gathering part is the communication passage 3a.
communicated by. 7 and 8 are a main turbocharger and a sub-turbocharger arranged in parallel with each other. Turbines 7a and 8 of turbochargers 7 and 8, respectively
a is connected to a gathering part of the exhaust manifold 3, and each compressor 7b, 8b is connected to the surge tank 2 via an intercooler 6 and a throttle valve 4.

The main turbocharger 7 is operated from a low intake air amount region to a high intake air amount region, and the auxiliary turbocharger 8 is stopped in a low intake air amount region. In order to enable operation and stop of both turbochargers 7 and 8, an exhaust switching valve 1 is provided downstream of the turbine 8a of the auxiliary turbocharger 8.
7, an intake switching valve 18 is provided downstream of the compressor 8b. When both the intake and exhaust switching valves 18 and 17 are open, both turbochargers 7 and 8 are operated. The downstream side of the turbine 8 a of the auxiliary turbocharger 8 and the downstream side of the turbine 7 a of the main turbocharger 7 can communicate with each other via an exhaust bypass passage 40 . The exhaust bypass passage 40 is provided with an exhaust bypass valve 41 that opens and closes the exhaust bypass passage 40. Exhaust bypass valve 41
are opened and closed by a diaphragm actuator 42.

The intake passage of the auxiliary turbocharger 8, which is stopped in the low intake air amount region, has one turbocharger and two
In order to smoothly switch to the individual turbocharger, an intake bypass passage 13 that communicates between the upstream of the compressor 7b and the downstream of the compressor 8b, and an intake bypass valve 33 disposed in the middle of the intake bypass passage 13 are provided. . The intake bypass valve 33 is a diaphragm type actuator 1
Opened and closed by 0. A check valve 12 is provided in a bypass passage that communicates the upstream and downstream sides of the intake switching valve 18 , and when the intake switching valve 18 is closed, the compressor outlet pressure on the sub-turbocharger 8 side reaches the main turbocharger 7 .
When the side becomes larger than the side, air can flow from the upstream side to the downstream side. In the figure, 14 indicates an intake passage on the compressor outlet side, and 15 indicates an intake passage on the compressor inlet side. The intake passage 15 is connected to an air cleaner 23 via an air flow meter 24. The front pipe 20 forming the exhaust passage includes an exhaust gas catalyst 21,
22 to an exhaust muffler (not shown). The intake switching valve 18 is opened and closed by the actuator 11, and the exhaust switching valve 17 is opened and closed by the diaphragm type actuator 16.
It is designed to be opened and closed by. The waste gate valve 31 is opened and closed by an actuator 9.

Actuators 9, 10, 11, 16, 4
2 is operated by introducing supercharging pressure or negative pressure. Each actuator 9, 10, 11, 16,
42 includes first, second, third, fourth, fifth, and 6th
Solenoid valves 25, 26, 27, 28, 32, and 44 are connected. Each solenoid valve 25, 26, 27, 28, 32, 4
4 is performed according to a command from the engine control computer 29. Note that the second solenoid valve 26
A check valve 45 that allows only one flow of negative pressure is interposed in the passage for introducing negative pressure into the valve.

[0014] When the first solenoid valve 25 is turned on, the intake switching valve 1
The actuator 11 is operated so as to fully open 8.
OFF operates the actuator 11 to fully close the intake switching valve 18. When the fourth solenoid valve 28 is turned ON, the actuator 16 is actuated to fully open the exhaust switching valve 17, and when it is OFF, the actuator 10 is actuated to fully close the exhaust switching valve 17. O of the third solenoid valve 27
N operates the actuator 10 to fully close the intake bypass valve 33, and OFF operates the actuator 10 to fully open the intake bypass valve 33.

The fifth solenoid valve 32 that introduces atmospheric pressure into the actuator 42 that operates the exhaust bypass valve 41 is operated by the
N, not OFF control but duty control. Similarly, the sixth solenoid valve 44 that guides supercharging pressure to the actuator 9 that operates the waste gate valve 31 is also turned on and off.
It is not controlled but is duty controlled. As is well known, duty control is to control the energization time by the duty ratio, and by digitally changing the ratio of energization and non-energization, the average current is variably controlled in an analog manner. Note that the duty ratio is the ratio of the energizing time to the time of one cycle, and if the energizing time in one cycle is A and the non-energizing time is B, then the duty ratio = A / (A + B) ×
It is expressed as 100 (%). In this embodiment, by controlling the duty of the fifth solenoid valve 32 and the sixth solenoid valve 44, it is possible to vary the opening amounts of these solenoid valves.

The opening degree of the exhaust bypass valve 41 is determined by varying the amount of bleed (leak amount) of the supercharging pressure introduced into the diaphragm chamber 42a of the actuator 42 into the atmosphere by controlling the duty of the fifth solenoid valve 32. It is variable. The opening degree of the waste gate valve 31 is determined by controlling the amount of bleed (leak amount) of the supercharging pressure introduced into the diaphragm chamber 9b of the actuator 9 to the atmosphere.
It can be made variable by changing the duty control of No. 4.

The engine control computer 29 is electrically connected to sensors for detecting various operating conditions of the engine, and receives signals from the various sensors. The engine operating condition detection sensors include an intake pipe pressure sensor 30, a throttle opening sensor 5, an air flow meter 24 as an intake air amount measuring sensor, an engine speed sensor 50, and an oxygen sensor 19. The engine control computer 29 includes a central processor unit (CPU) for calculations, a read-only memory (ROM), a random access memory (RAM) for temporary storage, and an input/output interface (I/O interface).
(O interface), and an A/D converter that converts analog signals from various sensors into digital quantities.

The rotational driving force of the engine 1 is transmitted through the automatic transmission 6.
1. The automatic transmission 61 is
For example, it is composed of an overdrive 4-speed transmission with a direct coupling clutch, and receives a vehicle speed signal S from a vehicle speed sensor 55.
, throttle opening signal S from throttle opening sensor 5
2. The automatic transmission control device 62 receives the shift position signal S3 from the shift sensor 56. The automatic transmission control device 62 and the automatic transmission 61 are electrically connected via a first delay means 63. The first delay means 63 has a function of delaying the transition time of the gear ratio in the downshift direction based on turbo lag. Note that the automatic transmission control device 62 and the first delay means 63 may have a configuration in which they share the same CPU (central processing unit), or may have a configuration in which they have separate CPUs.

Regarding the relationship between engine speed and turbo lag, the turbo lag increases as the engine speed decreases. Therefore, the first delay means 63 of this embodiment is set such that the lower the engine speed, the longer the transition time to downshifting of the gear ratio. This means that the gear ratio is maintained until the boost pressure increases to a predetermined value and the engine output torque reaches steady torque.

Next, the operation of the first embodiment will be explained. In the high intake air amount region, both the intake switching valve 18 and the exhaust switching valve 17 are opened, and the intake bypass valve 33 is closed. As a result, the two turbochargers 7 and 8 are driven, a sufficient amount of supercharging air is obtained, and the output is improved. In a low speed range and under high load, both the intake switching valve 18 and the exhaust switching valve 17 are closed, and the intake bypass valve 33 is opened. As a result, only one turbocharger 7 is driven. The reason why one turbocharger is used in the low intake air amount range is that the supercharging characteristics of one turbocharger are superior to the supercharging characteristics of two turbochargers in the low intake air amount range. By using one turbocharger,
Boost pressure and torque rise faster, resulting in faster response. When transitioning from a low intake air amount region to a high intake air amount region, that is, when switching from one turbocharger operation to two turbocharger operation, the exhaust bypass valve is closed while the intake switching valve 18 and the exhaust switching valve 17 are closed. 41 is slightly opened by duty control and further closes the intake bypass valve 33 to increase the run-up rotation speed of the auxiliary turbocharger 8, making it possible to switch the turbocharger more smoothly (with less shock during switching). become.

FIG. 7 shows operating states of upshift and downshift, which are set based on the relationship between throttle opening and vehicle speed. The vehicle speed is actually determined as the output shaft rotation speed of the automatic transmission 61. In FIG. 7, point A0 indicates the throttle opening immediately before acceleration, and point D0 indicates the throttle opening immediately after acceleration. B0 point is
It shows the throttle opening when downshifting from 3rd gear to 2nd gear. Point C0 indicates the throttle opening degree when shifting up from 2nd speed to 3rd speed. FIG. 8 shows the relationship between throttle opening, boost pressure, and output torque. In FIG. 8, point a shows the output torque just before acceleration, and point e shows the output torque required for acceleration. E
The dots indicate the throttle opening required for acceleration.

[0022] Exhaust turbine supercharger (turbocharger)
In engines equipped with this, there is always a turbo lag, which is the time required for the boost pressure to rise to a predetermined value after the accelerator pedal is depressed. Therefore, immediately after acceleration, the throttle opening is too large relative to the vehicle speed, which increases as the output torque increases, resulting in a problem that the automatic gear ratio is downshifted. Unnecessary gear ratio downshifting due to turbo lag has a negative impact on drivability and fuel efficiency.

Therefore, in this embodiment, unnecessary downshifting of the gear ratio is prevented by the processing shown in FIGS. 3 and 4. Note that FIGS. 3 and 4 show processing in the case of downshifting from 3rd speed to 2nd speed in a 4-speed automatic transmission. 3 and 4, the downshift delay control process is started in step 101, and step 102
It is determined whether the shift position is 3rd speed or not. If it is determined that the shift position of the iron is not 3rd speed, the process proceeds to step 116, and the process for 2nd or 4th speed is performed in the same procedure as the process for 3rd speed in this embodiment, which will be described later. The process advances to step 120 and ends.

In step 102, the shift position is 3.
If it is determined that the speed is fast, proceed to step 103,
Throttle opening degree TA is taken in. Throttle opening TA
When the vehicle speed (SPD
) is imported. Next, the process proceeds to step 105, where the throttle opening degree (TA2) is determined when downshifting from the vehicle speed.
is required. This is determined based on the map shown in FIG. The throttle opening TA1 shown in FIG. 5 is applied when downshifting from 2nd speed to 1st speed, and the throttle opening TA2 is applied when downshifting from 3rd speed to 2nd speed in this embodiment. applicable when applicable. Throttle opening degree TA3 is applied when downshifting from 4th gear to 3rd gear.

In step 105, when the throttle opening degree TA2 is determined based on the vehicle speed, step 10
In step 6, the actual throttle opening TA and the throttle opening TA2 determined from the map are compared. Here, if it is determined that the actual throttle opening TA is smaller than the throttle opening TA2 according to the map, the process proceeds to step 114, where the counter A in the CPU is set to 0, and the process proceeds to step 115. In step 115, it is determined that the downshift from 3rd speed to 2nd speed will not be performed, and the process proceeds to step 120 to complete the process.

If it is determined in step 106 that the actual throttle opening TA is larger than the throttle opening TA2 according to the map, the process proceeds to step 107, where the throttle opening TA2 is subtracted from the throttle opening TA. The opening difference ΔTA is determined. TA-TA2 =
Once ΔTA is determined, the process proceeds to step 108, where a delay counter (CDWN) is determined from the opening degree difference ΔTA. This delay counter is obtained from the map shown in FIG. FIG. 6 shows the amount of delay with respect to the opening degree difference ΔTA, and when downshifting from 3rd speed to 2nd speed, characteristic D2 shown by the solid line is applied. When downshifting from 2nd speed to 1st speed, characteristic D1 is applied, and when downshifting from 4th speed to 3rd speed, characteristic D3 is applied.

When the process of step 108 is completed, the process proceeds to step 109, where the counter A in the CPU becomes A+.
CDOWN and the process proceeds to step 110. Step 1
In step 10, it is determined whether A>\FF in the 8-bit CPU. Here, if it is determined that A>\FF is not true, the process proceeds to step 112. Step 110
If it is determined that A>¥FF, step 11
1, and counter A is set to ¥FF.

When the processing in step 111 is completed, the process proceeds to step 112, where the counter A has the delay characteristic B shown in FIG.
(delay time BNE in this embodiment). In this embodiment, the delay time is set based on the engine speed NE, and the delay time BNE is set to become longer as the engine speed NE becomes lower. Step 1
12, if it is determined that BNE<A is not true,
Proceed to step 120 and the process is complete. Step 11
If it is determined that BNE<A in step 2, step 1
The process proceeds to step 13, where a downshift from third speed to second speed is executed, and the process proceeds to step 120, where the process is completed.

In this way, the transition time for downshifting from 3rd gear to 2nd gear is delayed by the processing from step 106 to step 113, and the gear ratio is maintained as it is.
This solves the conventional problem of the gear ratio of the automatic transmission 61 being downshifted from 3rd speed to 2nd speed even if the throttle opening becomes temporarily large relative to the vehicle speed immediately after the vehicle accelerates. Therefore, unnecessary downshifting of the gear ratio due to turbo lag is prevented, and drivability and fuel efficiency are improved.

Although this embodiment has been described for a two-stage twin turbo in which one engine is provided with two turbochargers, it is of course applicable to a single turbo in which one turbocharger is provided in one engine. It is.

Second Embodiment FIG. 10 shows a second embodiment of the present invention. The only difference between the second embodiment and the first embodiment is the standard for setting the delay time when transitioning to downshifting, and the configuration of the other parts is the same, so a description of the corresponding parts will be omitted and the differences will be omitted. Only parts will be explained. The same applies to other embodiments to be described later. Turbo lag becomes larger as you go to higher altitudes than lower altitudes, so in this example, as shown in FIG. 10, the delay time Bpa when shifting to downshift is
is set longer at higher altitudes than at lower altitudes. This is because the air is thinner in highlands than in lowlands, and by setting the downshift delay time Bpa longer in highlands, it is possible to reliably prevent unnecessary downshifts.

Third Embodiment FIG. 11 shows a third embodiment of the present invention. Since turbo lag does not occur in a state where the intake pipe pressure is negative, the delay time BPB for downshifting is set by the first delay means 63 only when the intake pipe pressure becomes positive pressure. .

Fourth Embodiment FIG. 12 shows a fourth embodiment of the present invention. In this embodiment, the downshift delay control is performed in the range where the throttle opening is from a medium opening to a high opening. Furthermore, the delay time BTA is set to become shorter as the throttle opening becomes higher, as shown in FIG. 12.

Fifth Embodiment FIGS. 13 and 14 show a fifth embodiment of the present invention. FIG. 13 shows a block diagram corresponding to the present invention, and the basic configuration is the same as that in FIG. 1 of the first embodiment. Figure 1
As shown in FIG. 3, the automatic transmission control device 62 and the automatic transmission 61 are electrically connected via a second delay means 81. The second delay means 81 has a function of delaying the transition time of the gear ratio in the downshift direction based on turbo lag. Note that, similarly to the first embodiment, the automatic transmission control device 62 and the second delay means 81 are operated by the same CPU (
A configuration may be adopted in which a central processing unit (central processing unit) is shared, or a configuration in which separate CPUs are provided.

Since the turbo lag is larger when both the main turbocharger 7 and the sub-turbocharger 8 are supercharged (two turbochargers) than when only the main turbocharger 7 is supercharged (one turbocharger), this implementation In the example, the delay time for shifting down during supercharging operation of two turbochargers is set to be longer than that for one turbocharger. Therefore, during acceleration, even if the throttle opening is large relative to the vehicle speed, unnecessary gear ratio downshifts are reliably prevented.

[0036]

[Effects of the Invention] As explained above, according to the automatic transmission control device for a vehicle equipped with a supercharged engine according to the present invention,
The following effects can be obtained. (b) A first step that causes the automatic transmission control device to delay the transition time of the gear ratio in the downshift direction based on turbo lag.
Since the first delay means is provided and the delay time of the first delay means is set to be longer under operating conditions where the turbo lag is large, it is possible to prevent unnecessary gear ratio downshifts caused by the turbo lag. Thereby, the drivability and fuel efficiency of the vehicle can be improved. (b) The automatic transmission control device is provided with a second delay means for delaying the transition time of the gear ratio in the downshift direction based on the turbo lag, and the delay time of the second delay means is set to supercharge only the main turbocharger. Since the supercharging operating ranges of both the main turbocharger and the auxiliary turbocharger are set longer than the operating ranges, unnecessary gear ratio downshifts due to turbo lag are prevented in either supercharging range. It is possible to improve vehicle drivability and fuel efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an automatic transmission control device for a vehicle equipped with a supercharged engine according to a first embodiment of the present invention.

FIG. 2 is a schematic system diagram of the supercharged engine in FIG. 1.

FIG. 3 is a flowchart showing the first half of a delay control processing procedure in a first delay means of the apparatus shown in FIG. 1;

FIG. 4 is a flowchart showing the second half of the delay control processing procedure in the first delay means of the device in FIG. 1;

FIG. 5 is a conceptual diagram of a throttle opening calculation map used for the delay control in FIGS. 3 and 4;

FIG. 6 is a conceptual diagram of a delay counter calculation map used for the delay control in FIGS. 3 and 4;

FIG. 7 is a conceptual diagram of a map used for setting upshifts and downshifts of the gear ratio in the apparatus of FIG. 1;

FIG. 8 is a characteristic diagram showing the relationship between throttle opening, supercharging pressure, and output torque in the device shown in FIG. 2;

9 is a characteristic diagram showing the relationship between engine rotation speed and delay time in the device of FIG. 1. FIG.

FIG. 10 is a characteristic diagram showing the relationship between altitude and delay time in an automatic transmission control device for a vehicle equipped with a supercharged engine according to a second embodiment of the present invention.

FIG. 11 is a characteristic diagram showing the relationship between intake pipe pressure and delay time in an automatic transmission control device for a vehicle equipped with a supercharged engine according to a third embodiment of the present invention.

FIG. 12 is a characteristic diagram showing the relationship between throttle opening and delay time in an automatic transmission control device for a vehicle equipped with a supercharged engine according to a fourth embodiment of the present invention.

FIG. 13 is a block diagram of an automatic transmission control device for a vehicle equipped with a supercharged engine according to a fifth embodiment of the present invention.

14 is a characteristic diagram showing the relationship between the supercharging operation region and the delay time in the device of FIG. 13. FIG.

[Explanation of symbols]

1 Engine 4 Throttle valve 5 Throttle opening sensor 7 Main turbocharger 8 Sub-turbocharger 61 Automatic transmission 62 Automatic transmission control device 63 First delay means 81 Second delay means

Claims (2)

[Claims] Claims: 1. An automatic transmission control device for a vehicle equipped with an engine equipped with an exhaust turbine supercharger, the automatic transmission control device comprising: a first step for delaying a transition time to downshifting of a gear ratio based on turbo lag; 1. An automatic transmission control device for a vehicle equipped with a supercharged engine, characterized in that a delay means is provided, and the delay time of the first delay means is set to be longer as the driving condition increases the turbo lag. [Claim 2] An exhaust turbine supercharger with which only the main turbocharger is operated for supercharging in a low intake air amount range, and both the main turbocharger and the auxiliary turbocharger are operated for supercharging in a high intake air amount range. In an automatic transmission control device for a vehicle equipped with an engine, the automatic transmission control device is provided with a second delay means for delaying a transition time to a downshift of a gear ratio based on turbo lag,
A vehicle equipped with a supercharged engine, characterized in that the delay time of the delay means is set longer in the supercharging operating range of both the main turbocharger and the auxiliary turbocharger than the supercharging operating range of only the main turbocharger. automatic transmission control device.