JP3589826B2 - Transmission control device for automatic transmission - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an automatic transmission having a transmission mechanism in which a one-way clutch and a multi-plate clutch are provided in parallel, and a shift control device for the automatic transmission that suppresses a peak torque generated due to backlash of the transmission mechanism when an accelerator is quickly depressed. Belongs to the technical field.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an automatic transmission provided with a transmission mechanism in which a one-way clutch and a multi-plate clutch are provided in parallel, for example, one disclosed in Japanese Patent Application Laid-Open No. 62-288759 is known.
[0003]
In this publication, a one-way clutch 12 and a multi-plate clutch 13 for engine braking are provided in parallel with a transmission mechanism, and a multi-plate clutch is provided by engaging the one-way clutch 12 so as not to cause a shift shock during a power-on downshift. A technique for controlling the clutch 13 so as not to be engaged earlier is described.
[0004]
Incidentally, as shown in FIG. 3 of the publication, the multiple disc clutch 13 (C0) is engaged except in the D range fourth speed.
[0005]
Here, the necessity of maintaining the engagement of the multi-plate clutch 13 will be described.
[0006]
The multi-plate clutch 13 is a clutch used for engine braking in the first place, but when the throttle opening is returned from the driving state at a fixed gear position, if the engine brake is not immediately applied, a feeling of idling occurs and a sense of incongruity appears. There is.
[0007]
Recently, as described in “Motor Magazine (May)” issued by Motor Magazine on May 1, 1995, the manual shift of the automatic transmission has been progressing, and the above-mentioned uncomfortable feeling has caused the drivability. It is also a big negative point. In order to prevent such a sense of discomfort, it is necessary to fasten the multiple disc clutch 13 (even on the drive side). By fastening the multiple disc clutch 13, a direct feeling like a manual transmission is obtained. .
[0008]
[Problems to be solved by the invention]
However, in the above-described conventional shift control device for an automatic transmission, an engine braking feeling can be immediately obtained when the drive side (drive side) is switched to the driven side (coast side) by the engagement of the multi-plate clutch 13. Although it is possible, since the multi-plate clutch 13 is still engaged when shifting from the driven side to the driving side, the spline fitting portion of the clutch plate receives a peak torque generated by a sudden and deep stepping operation of the accelerator. There is a problem.
[0009]
That is, when the accelerator pedal is depressed, the one-way clutch 12 is engaged to receive the input torque according to the torque flow at the time of driving, and the torque is not applied to the multi-plate clutch 13. Since the play angle due to the play of the spline fitting of the clutch plate of the multiple disc clutch 13 is smaller than the rotation angle required for the clutch 12 to be engaged, the input torque is applied to the spline fitting portion before the one-way clutch 12 is engaged. I will receive it.
[0010]
When the one-way clutch 12 shifts from the idle driven side to the driving side, a plurality of sprags interposed between the outer race and the inner race rotate, and both races are integrated via the sprag. And a predetermined rotation angle is required for the engagement.
[0011]
In particular, the frequency becomes even higher when a manual shift is performed. In order for the spline fitting portion to receive the peak torque generated by the sudden and deep stepping operation of the accelerator, the spline fitting portion should be considered in view of durability. Have to be thicker. Further, when the peak torque is received only by the one-way clutch, a one-way clutch engagement shock becomes a problem.
[0012]
Originally, a clutch designed for engine braking only receives coasting torque (engine inertia + torque converter inertia). However, when the engine receives the peak torque generated by the backlash of the engine or the power train, wear of the spline fitting portion progresses, resulting in a decrease in durability.
[0013]
The problem to be solved by the present invention is to improve the responsiveness of the engine brake feeling when the driving side changes from the driving side to the driven side, and to increase the number of discs when the driving side changes from the driving side to the driving side with a peak torque generating operation. An object of the present invention is to provide a shift control device for an automatic transmission that achieves both improved clutch durability and prevention of one-way clutch engagement shock.
[0014]
[Means for Solving the Problems]
The present invention has been made in order to solve the above problems, and in the present invention, the input torque when the spline fitting portion of the multi-plate clutch for engine braking receives a large reaction force is such that the throttle opening is fully closed. Focusing on the point at which peak torque is generated when the driver steps deeply quickly from the coasting state, when such torque is generated, the engagement pressure of the multi-plate clutch is reduced and the one-way clutch is engaged. At the end of the process, the engagement pressure of the multi-plate clutch is returned to the original pressure, and the system is devised to prepare for engine braking during coasting.
[0015]
(Solution 1)
Means for solving the above problem 1 (claim 1) is that, as shown in the claim correspondence diagram of FIG. 1, a one-way clutch a and a multi-plate clutch b are arranged in parallel between a first rotating member c and a second rotating member d. Equipped with a transmission mechanism provided by
The one-way clutch a is a clutch that engages when driving from the engine side to the wheel side and idles when driven,
The multi-plate clutch b is a clutch having plates that are spline-fitted to the drum and the hub, respectively. The engagement / release is controlled by hydraulic pressure applied to a piston, and in an automatic transmission that maintains clutch engagement even on the drive side. ,
Peak torque generating operation detecting means e for detecting a peak torque generating operation;
A clutch hydraulic pressure control means f for performing control to reduce the engagement pressure of the multi-plate clutch b for a set time necessary for the idle one-way clutch a to be engaged when the peak torque generation operation is detected;
It is characterized by having.
[0016]
(Solution 2)
Means for solving the above problem 2 (claim 2) is the shift control device for an automatic transmission according to claim 1,
The peak torque generating operation detecting means e is a means for deeming a peak torque generating operation when a throttle opening speed detection value, which is a changing speed of the throttle opening in the opening direction, exceeds a preset throttle opening speed threshold value. It is characterized by the following.
[0017]
(Solution 3)
According to a third aspect of the present invention, there is provided a shift control device for an automatic transmission according to the first or second aspect.
When the peak pressure generating operation is detected, the clutch hydraulic pressure control means f is replaced with a normal line pressure control that sets a line pressure corresponding to the throttle opening, and the clutch hydraulic pressure control means f is engaged only for a set time necessary for engagement of the one-way clutch a. Means for reducing the line pressure to a hydraulic pressure level at which the fastening element does not slip.
[0018]
(Solution 4)
According to a fourth aspect of the present invention, there is provided a shift control device for an automatic transmission according to the first or second aspect.
The clutch hydraulic pressure control means f may be a means for performing control for draining or reducing the engagement pressure of the multi-plate clutch b alone for a set time required for engagement of the one-way clutch a when the peak torque generation operation is detected. And
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
Embodiment 1 is a shift control device for an automatic transmission according to the first, second, and third aspects of the present invention.
[0020]
First, the configuration will be described.
[0021]
FIG. 2 is a diagram showing a gear train (transmission mechanism) of the automatic transmission to which the transmission control device of the first embodiment is applied.
[0022]
The gear train includes two sets of planetary gears, four sets of multiple disc clutches, one set of multiple disc brakes, one set of band brakes, and two sets of one-way clutches.
[0023]
2, 1 is a torque converter, 2 is an oil pump, 3 is an input shaft, 4 is a band brake, 5 is a reverse clutch, 6 is a high clutch, 7 is a front sun gear, 8 is a front pinion, 9 is a front ring gear, 10 Is a front carrier, 11 is a rear sun gear, 12 is a rear pinion, 13 is a rear ring gear, 14 is a rear carrier, 15 is a forward clutch, 16 is a forward one-way clutch, 17 is an overrun clutch, 18 is a low one-way clutch, and 19 is a low and reverse brake. , 20 is a parking pole, 21 is a parking gear, and 22 is an output shaft.
[0024]
FIG. 3 is a control system diagram of an automatic transmission to which the transmission control device of the first embodiment is applied.
[0025]
The four-stage forward-range full-range electronic control is employed. The A / T control unit 30 includes an idle switch 31, a full throttle switch 32, a throttle sensor 33, an engine rotation sensor 34 attached to the engine, an inhibitor switch 35 attached to the transmission, and the like. Input information from the temperature sensor 36, the vehicle speed sensor 37, and the like is captured by an electric signal, information processing is performed according to a set control program, and shift actuators A38, B39, an overrun clutch solenoid 40, and a lock-up solenoid, which are shift actuators. A control command is output to the control unit 41 and the line pressure solenoid 42.
[0026]
FIG. 4 is a diagram showing a shift schedule used in a shift control performed by the automatic transmission to which the shift control device according to the first embodiment is applied, and FIG. 5 is a shift solenoid operation table at each gear position in the shift control. FIG. 6 and FIG. 6 are diagrams showing a fastening operation table at each gear position.
[0027]
In the shift control, when the operating point determined by the detected throttle opening and the vehicle speed crosses the upshift line or the downshift line in the shift schedule of FIG. 4, a shift determination command is output, and the shift is performed according to the shift solenoid operation table shown in FIG. An ON / OFF command corresponding to the gear position after the shift is output to the solenoid A38 and the shift solenoid B39, and the shift is performed by operating a shift valve that switches an oil passage.
[0028]
In each gear position, the shifting element operates as shown in FIG. The forward one-way clutch 16 (F / OC) is in the engaged state and transmits power in the driving state except for the 4th speed in the D range, but is idle on the driven side. The forward clutch 15 (F / C) is always engaged, and the overrun clutch 17 (O / C) is engaged at an accelerator opening of 1/16 or less, except for the fourth speed in the D range, to apply the engine brake.
[0029]
FIG. 7 is a main part system diagram showing the transmission control device of the first embodiment.
[0030]
In FIG. 7, 16 is a forward one-way clutch (corresponding to a one-way clutch a), 17 is an overrun clutch (corresponding to a multi-plate clutch b), and 45 is a forward & overrun clutch drum (a drum that also serves as the first rotating member c). Reference numeral 46 denotes an overrun clutch hub (corresponding to a hub also serving as the second rotating member d), and reference numeral 30 denotes an A / T control unit (corresponding to an electronic control unit of the throttle opening speed detecting means e and the clutch hydraulic pressure controlling means f). And 42, a line pressure solenoid (corresponding to the actuator of the clutch oil pressure control means f), 2 an oil pump, 47 a pilot valve, 48 a pressure modifier valve, 49 a pressure regulator valve, 50 a transmission control valve, and 51 a transmission control valve. Line pressure oil passage, 52 is an overrun clutch Oil passage (corresponding to a hydraulic control unit of the clutch hydraulic pressure control means f), 15 the forward clutch 53 is forward clutch hub 54 is forward clutch pressure oil passage.
[0031]
The forward one-way clutch 16 and the overrun clutch 17 are provided in parallel between a forward & overrun clutch drum 45 and an overrun clutch hub 46.
[0032]
The forward one-way clutch 16 is a clutch that engages when driving from the engine side to the wheel side during downshifting and idles when driven, and includes an inner race 16a, an outer race 16b, and a scrub 16c. . The rear ring gear 13 and the overrun clutch hub 46 are integrally fixed to the inner race 16a. A forward clutch hub 53 is integrally fixed to the outer race 16b. A plurality of scrubs 16c are interposed equally between the races 16a and 16b by a retainer. When the outer race 16b rotates in the driving direction, the scrub 16c rotates in the same direction, but the center of curvature of the inner and outer surfaces is eccentric. As a result, a wedge action occurs and transmits torque.
[0033]
The overrun clutch 17 includes a drive plate 17a spline-fitted to the forward & overrun clutch drum 45, a driven plate 17b spline-fitted to the overrun clutch hub 46, and two plates 17a, There is a clutch having a clutch piston 17c for engaging the clutch 17b. The engagement / release is controlled by the hydraulic pressure applied to the clutch piston 17c after passing through the overrun clutch pressure oil passage 52, and the clutch is maintained on the drive side. A front carrier 10 supporting the front pinion 8 is spline-fitted to one end of the forward & overrun clutch drum 45, and the other end is used as a part of a piston cylinder of the forward clutch 15.
[0034]
In the first embodiment, a line pressure control for controlling a line pressure which is a source pressure of the engagement pressure is employed as the engagement pressure control of the overrun clutch 17. In the line pressure control, when the throttle sensor 33 detects the throttle opening and sends a signal to the A / T control unit 30, the A / T control unit 30 duty-controls the line pressure solenoid 42 to increase the pilot oil pressure to the maximum pressure. Adjust the throttle pressure. This pressure is adjusted to a pressure modifier pressure by a pressure modifier valve 48 using the throttle pressure as a signal pressure, and the oil pump discharge pressure is adjusted to a line pressure by a pressure regulator valve 49 using the pressure modifier pressure as a signal pressure. . Then, the line pressure passes through the transmission control valve 50 such as a shift valve and the overrun clutch pressure oil passage 52 and is guided to the piston oil chamber of the overrun clutch 17. That is, when the line pressure is changed, the fastening pressure of the fastening elements simultaneously engaged other than the overrun clutch 17 is changed.
[0035]
Next, the operation will be described.
[0036]
[Line pressure control operation]
FIG. 8 is a flowchart showing the flow of the line pressure control operation performed by the A / T control unit 30, and each step will be described below.
[0037]
In step 80, the throttle opening TH is read.
[0038]
In step 81, the throttle opening speed TH / ΔT is calculated by a differential calculation process of dividing the throttle opening TH by the unit time ΔT (corresponding to the throttle opening speed detecting means e), and the throttle opening speed TH / ΔT is used as a peak torque generating operation. It is determined whether or not the throttle opening speed threshold value A considered to be exceeded is exceeded.
[0039]
In step 82, when it is determined that TH / ΔT ≦ A, normal line pressure control is executed.
[0040]
In step 83, when it is determined that TH / ΔT> A, instead of the normal line pressure control, in order to establish the gear position for the set time T required for the idle forward one-way clutch 16 to engage, the gear position is established. Control is performed to reduce the line pressure to a hydraulic pressure level (duty ratio = B) at which the other engaged elements do not slip.
[0041]
[Normal line pressure control action]
The normal line pressure control is performed by the flow of step 80 → step 81 → step 82 in the flowchart of FIG.
[0042]
In this control, as shown in FIG. 9, the engine load is determined based on the throttle opening, and a line pressure characteristic according to the throttle opening is set in advance for each range.
[0043]
Therefore, depending on the detected throttle opening and the selected range position, the pressure is adjusted to a line pressure of a pressure necessary for each of the fastening elements such as the clutch and the brake to maintain the engagement and a pressure with a small pump loss. Is done.
[0044]
[Line pressure control action during peak torque generation operation]
The line pressure control at the time of the peak torque generating operation is performed according to the flow of step 80 → step 81 → step 83 in the flowchart of FIG.
[0045]
In this control, a time T for decreasing the line pressure and a decrease level B of the line pressure are set in advance, and the line pressure decreasing time T needs a time enough for the forward one-way clutch 16 to be engaged. T = about 0.2 to 0.3 sec, and the line pressure drop level B is, for example, the torque when the stall capacity guarantees the capacity of the fastening element for configuring each gear position from the involvement of the hold mode. Outside the converter region, there is no risk that the fastening element will slip even at a pressure of about half of the hydraulic pressure level normally used.
[0046]
Therefore, when the overrun clutch 17 is engaged and the driving side is changed from the driven side to the driving side with the peak torque generating operation, the engagement pressure of the overrun clutch 17 is temporarily reduced, so that the spline fitting portion is formed. The peak torque to be received is released by the slip of the overrun clutch 17, and the peak torque is received by both the overrun clutch 17 and the forward one-way clutch 16. Therefore, the durability of the spline fitting portion is improved as compared with the case where the overrun clutch 17 is kept engaged. Further, an excessive engagement shock of the forward one-way clutch 16 is prevented as compared with the conventional example in which the peak torque is received only by the one-way clutch (see FIG. 10).
[0047]
Then, after the forward one-way clutch 16 is engaged and the forward one-way clutch 16 has a torque, the engagement pressure of the overrun clutch 17 is returned to the original pressure again to prepare for securing the engine brake during coasting. Will be.
[0048]
Next, effects will be described.
[0049]
(1) In an automatic transmission having a transmission mechanism in which a forward one-way clutch 16 and an overrun clutch 17 are provided in parallel between two rotating members, a drive in which the forward one-way clutch 16 changes from an engaged state to an idle state. The overrun clutch 17 is maintained engaged even on the driving side so that the engine brake is secured immediately upon the transition from the side to the driven side, and the throttle opening speed detection value TH / ΔT is regarded as a peak torque generating operation. When the throttle opening speed threshold value A is exceeded, a device for performing clutch hydraulic pressure control for performing control to reduce the engagement pressure of the overrun clutch 17 for a set time T required for engaging the idle one-way clutch 16 for engagement. Response from the driving side to the driven side It can be achieved improvement and, to balance the multiple disc clutch durability and the one-way clutch engagement shock prevention when it becomes the driving side from the driven side with a peak torque generation operations.
[0050]
(2) When the throttle opening speed detection value TH / ΔT, which is the changing speed of the throttle opening in the opening direction, exceeds a preset throttle opening speed threshold value A, the operation is regarded as a peak torque generating operation. The peak torque generating operation can be detected by using the throttle sensor 33 as it is.
[0051]
(3) When controlling the engagement pressure of the overrun clutch 17, when the throttle opening speed detection value TH / ΔT exceeds the throttle opening speed threshold value A, the normal line is set to a line pressure corresponding to the throttle opening TH. Instead of the pressure control, the existing line pressure control is performed to reduce the line pressure to a hydraulic pressure level at which the other engagement elements engaged for the set time T required for engagement of the forward one-way clutch 16 do not slip. By simply using the hardware of the A / T control unit 30 and simply changing the software of the A / T control unit 30, the control corresponding to the peak torque can be easily performed, and the careless refastening shock of other fastening elements accompanying the line pressure control can be achieved. Can be prevented.
[0052]
(Other embodiments)
In the first embodiment, the example in which the engagement pressure control of the overrun clutch 17 is performed by the line pressure control is described. However, the engagement pressure of the overrun clutch 17 is independently set using the on / off type overrun clutch solenoid 40. It may be configured to drain only by time, or may be reduced by a set time by using a duty type overrun clutch solenoid, in which case other fastening elements necessary to configure the gear position It is possible to perform the engagement pressure control of the overrun clutch that sufficiently suppresses the input of the peak torque without affecting the engagement of the overrun clutch (corresponding to claim 4).
[0053]
The transmission control device according to the present invention includes a transmission mechanism in which a one-way clutch and a multi-plate clutch are provided in parallel between a first rotating member and a second rotating member, in addition to the automatic transmission described in the first embodiment. The present invention can be applied to an automatic transmission having
[0054]
【The invention's effect】
The shift control device for an automatic transmission according to claim 1, further comprising a speed change mechanism in which a one-way clutch and a multi-plate clutch are provided in parallel between the first rotating member and the second rotating member. Is a clutch that engages when driving from the engine side to the wheel side and idles when driven, and the multi-plate clutch is a clutch that has plates spline-fitted to the drum and the hub, respectively, and is applied to the piston. In an automatic transmission in which engagement and disengagement is controlled by hydraulic pressure and the drive side also maintains clutch engagement, a peak torque generation operation detecting means for detecting a peak torque generation operation, and a one-way clutch in an idle state when the peak torque generation operation is detected. Clutch hydraulic pressure control means for performing control to reduce the engagement pressure of the multi-plate clutch for a set time necessary for engagement. Therefore, the responsiveness of the engine brake feeling when the driving side changes from the driven side to the driven side, the durability of the multi-plate clutch when the driving side changes from the driven side to the driving side with the peak torque generating operation, and the one-way clutch It is possible to achieve compatibility with joint shock prevention.
[0055]
According to a second aspect of the present invention, in the transmission control device for an automatic transmission according to the first aspect, the peak torque generation operation detecting means is provided with a throttle opening speed detection value which is a changing speed of the throttle opening in the opening direction. Means that a peak torque generation operation is considered when the throttle opening speed threshold value exceeds a preset throttle opening speed threshold value. In addition to the above effects, the existing throttle sensor 33 can be used as it is to detect the peak torque generation operation.
[0056]
According to a third aspect of the present invention, in the shift control device for an automatic transmission according to the first or second aspect, the clutch hydraulic pressure control means is provided with a line pressure corresponding to a throttle opening when a peak torque generating operation is detected. In place of the normal line pressure control, the means for performing the control to reduce the line pressure to a hydraulic pressure level that does not cause slippage of other fastening elements fastened for a set time necessary for engagement of the one-way clutch is adopted. In addition to the effects, it is possible to easily perform peak torque control simply by changing the software of the line pressure control, using the existing line pressure control hardware as it is, and to use other fastening elements associated with the line pressure control. Inadvertent refastening shocks can be prevented.
[0057]
According to a fourth aspect of the present invention, in the shift control device for an automatic transmission according to the first or second aspect, the clutch hydraulic pressure control means is configured to independently control the engagement pressure of the multi-plate clutch when the peak torque generation operation is detected. Means for performing control to drain or lower by a set time necessary for engagement of the one-way clutch, in addition to the above-described effects, without affecting the fastening of other fastening elements required to configure the gear position. Thus, it is possible to control the engagement pressure of the multi-plate clutch that sufficiently suppresses the input of the peak torque.
[Brief description of the drawings]
FIG. 1 is a diagram corresponding to claims showing a shift control device for an automatic transmission according to the present invention.
FIG. 2 is a diagram illustrating a gear train of the automatic transmission to which the shift control device according to the first embodiment is applied.
FIG. 3 is a control system diagram of an automatic transmission to which the shift control device of the first embodiment is applied.
FIG. 4 is a diagram showing a shift schedule used in a shift control performed in the automatic transmission to which the shift control device according to the first embodiment is applied.
FIG. 5 is a diagram showing a shift solenoid operation table at each gear position in the shift control.
FIG. 6 is a diagram showing a fastening operation table at each gear position.
FIG. 7 is a main part system diagram showing the transmission control device of the first embodiment.
FIG. 8 is a flowchart showing a flow of a line pressure control operation performed by the A / T control unit according to the first embodiment.
FIG. 9 is a line pressure control characteristic diagram used in normal line pressure control.
FIG. 10 is a time chart comparing characteristics of a throttle opening, a hydraulic duty, a vehicle front-rear driving degree, and an engine speed during a peak torque generating operation.
[Explanation of symbols]
a one-way clutch b multi-plate clutch c first rotating member d second rotating member e peak torque operation detecting means f clutch hydraulic pressure controlling means

Claims (4)

A transmission mechanism in which a one-way clutch and a multi-plate clutch are provided in parallel between the first rotating member and the second rotating member;
The one-way clutch is a clutch that engages when driven from the engine side to the wheel side and idles when driven,
The multi-plate clutch is a clutch having a plate that is spline-fitted to each of a drum and a hub, and engagement / release is controlled by hydraulic pressure applied to a piston, and in an automatic transmission that maintains clutch engagement even on the drive side,
Peak torque generating operation detecting means for detecting a peak torque generating operation;
At the time of peak torque generation operation detection, clutch hydraulic pressure control means for performing control to reduce the engagement pressure of the multi-plate clutch for a set time necessary for engaging the idle one-way clutch,
A shift control device for an automatic transmission, comprising: The shift control device for an automatic transmission according to claim 1,
The peak torque generating operation detecting means may be a means for determining that a peak torque generating operation is performed when a throttle opening speed detection value, which is a changing speed of the throttle opening in the opening direction, exceeds a preset throttle opening speed threshold value. A shift control device for an automatic transmission, comprising: The shift control device for an automatic transmission according to claim 1 or 2,
When the peak hydraulic torque generating operation is detected, the clutch hydraulic pressure control means is replaced with a normal line pressure control that sets a line pressure according to the throttle opening, and other clutches are engaged only for a set time necessary for engagement of the one-way clutch. A shift control device for an automatic transmission, characterized in that the shift control device reduces the line pressure to a hydraulic pressure level at which the element does not slip. The shift control device for an automatic transmission according to claim 1 or 2,
Wherein the clutch hydraulic pressure control means performs control to drain or reduce the engagement pressure of the multi-plate clutch independently for a set time required for engagement of the one-way clutch when the peak torque generation operation is detected. Transmission control device for transmission.

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