JP6930430B2 - Transmission controller - Google Patents

Description

The present invention relates to a transmission control device.

Conventionally, when the shift of the power-off upshift is started, it is determined whether the engine is in the driven state or the driven state, and when the engine is in the driven state, the operating oil pressure of the release side clutch is quickly lowered as compared with the case where the engine is in the driven state. As a result, a technique for suppressing torque shock during shifting in the driven state and improving drivability is disclosed (see, for example, Patent Document 1).

JP-A-2007-113645

The above-mentioned conventional technique has a problem that the shift time becomes long when the engine is in the driven state.

The present invention has been made in view of the above, and an object of the present invention is to provide a transmission control device capable of suppressing a prolongation of a shift time in an upshift in a driven state of an engine.

In order to solve the above-mentioned problems and achieve the object, the transmission control device according to the present invention is a transmission control device including a stepped transmission in which the engine is driven at the start of upshift control. In this case, the engaging pressure of the engaging clutch is gradually increased as compared with the case of the driven state, and the output rotation speed of the transmission is less than the predetermined rotation speed during the upshift in the driven state. Is characterized in that the engaging pressure of the engaging clutch is rapidly increased as compared with the case where the number of rotations is equal to or higher than the predetermined number of rotations.

According to the present invention, when the output rotation speed of the transmission is less than the predetermined rotation speed during the upshift in the driven state, the engagement pressure of the engaging clutch is increased as compared with the case where the rotation speed is equal to or higher than the predetermined rotation speed. Since it is raised quickly, it is possible to suppress a long shift time in the driven state.

FIG. 1 is a skeleton diagram schematically showing a vehicle provided with a power transmission mechanism. FIG. 2 is a flowchart showing an outline of processing performed by the transmission control device according to the embodiment of the present invention. FIG. 3 is a diagram illustrating a problem of the prior art.

Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described with reference to the accompanying drawings.

FIG. 1 is a skeleton diagram schematically showing a vehicle provided with a power transmission mechanism. The vehicle Ve includes an engine 1 as a power source. In the power transmission mechanism 100, the power output from the engine 1 is a torque converter 2, an input shaft 3, a forward / backward switching mechanism 4, a belt-type continuously variable transmission (hereinafter referred to as "CVT") 5, a gear train 6, and an output shaft. 7. It is transmitted to the drive wheels 11 via the counter gear mechanism 8, the differential gear 9, and the axle 10.

Specifically, the torque converter 2 is arranged between the pump impeller 2a connected to the engine 1, the turbine runner 2b arranged to face the pump impeller 2a, and the pump impeller 2a and the turbine runner 2b. It includes a stator 2c. The pump impeller 2a rotates integrally with the crankshaft 1a of the engine 1. The input shaft 3 is connected to the turbine runner 2b so as to rotate integrally. The torque converter 2 is provided with a lockup clutch, and in the engaged state, the pump impeller 2a and the turbine runner 2b rotate integrally, and in the open state, the power output from the engine 1 is transmitted to the turbine runner 2b via the working fluid. Will be done. The stator 2c is held by a fixed portion such as a case via a one-way clutch.

The input shaft 3 is connected to the forward / backward switching mechanism 4. When the engine torque is transmitted to the drive wheels 11, the forward / backward switching mechanism 4 switches the direction of the torque acting on the drive wheels 11 between the forward direction and the reverse direction. The forward / backward switching mechanism 4 is composed of a differential mechanism, and in the example shown in FIG. 1, it is composed of a double pinion type planetary gear mechanism. The forward / backward switching mechanism 4 meshes with the sun gear 4S, the ring gear 4R arranged concentrically with respect to the sun gear 4S, the first pinion gear 4P ₁ meshing with the sun gear 4S, the first pinion gear 4P ₁ and the ring gear 4R. It includes a second pinion gear 4P ₂ and a carrier 4C that holds the pinion gears 4P ₁ and 4P _{2 so} that they can rotate and revolve. The drive gear 61 of the gear train 6 is connected to the sun gear 4S so as to rotate integrally. The input shaft 3 is connected to the carrier 4C so as to rotate integrally.

Further, a first clutch C1 that selectively and integrally rotates the sun gear 4S and the carrier 4C is provided. The first clutch C1 functions as a starting clutch that engages when the vehicle Ve starts. In the power transmission mechanism 100, by engaging the first clutch C1, the entire forward / backward switching mechanism 4 rotates integrally. Further, a brake B1 for selectively fixing the ring gear 4R so as not to rotate is provided. The brake B1 engages when the vehicle Ve is moving backward. For example, when the first clutch C1 is engaged and the brake B1 is released, the sun gear 4S and the carrier 4C rotate integrally. That is, the input shaft 3 and the drive gear 61 rotate integrally. Further, when the first clutch C1 is released and the brake B1 is engaged, the sun gear 4S and the carrier 4C rotate in opposite directions. That is, the input shaft 3 and the drive gear 61 rotate in opposite directions. The first clutch C1 and the brake B1 are hydraulic.

In the vehicle Ve, the CVT 5 which is a continuously variable transmission and the gear train 6 which is a stepped transmission are arranged in parallel. As a power transmission path between the input shaft 3 and the output shaft 7, a power transmission path (first path) via the CVT 5 and a power transmission path (second path) via the gear train 6 are formed in parallel. There is.

The CVT 5 includes a primary pulley 51 that rotates integrally with the input shaft 3, a secondary pulley 52 that rotates integrally with the secondary shaft 54, and a belt 53 wound around a V groove formed in the pair of pulleys 51 and 52. There is. The input shaft 3 becomes the primary shaft. Since the winding diameter of the belt 53 is changed by changing the V-groove width of each of the pulleys 51 and 52, the gear ratio γ of the CVT 5 can be continuously changed. The gear ratio γ of the CVT 5 continuously changes within the range from the maximum gear ratio to the minimum gear ratio.

The primary pulley 51 includes a fixed sheave 51a integrated with the input shaft 3, a movable sheave 51b that can move in the axial direction on the input shaft 3, and a primary hydraulic actuator 51c that applies thrust to the movable sheave 51b. There is. The sheave surface of the fixed sheave 51a and the sheave surface of the movable sheave 51b face each other to form a V-groove of the primary pulley 51. The primary hydraulic actuator 51c is arranged on the back side of the movable sheave 51b. The hydraulic pressure supplied to the primary hydraulic actuator 51c generates a thrust that moves the movable sheave 51b toward the fixed sheave 51a.

The secondary pulley 52 includes a fixed sheave 52a integrated with the secondary shaft 54, a movable sheave 52b that can move in the axial direction on the secondary shaft 54, and a secondary hydraulic actuator 52c that applies thrust to the movable sheave 52b. There is. The sheave surface of the fixed sheave 52a and the sheave surface of the movable sheave 52b face each other to form a V-groove of the secondary pulley 52. The secondary hydraulic actuator 52c is arranged on the back side of the movable sheave 52b. The hydraulic pressure supplied to the secondary hydraulic actuator 52c generates a thrust that moves the movable sheave 52b toward the fixed sheave 52a.

A second clutch C2 is provided on the downstream side of the CVT 5 as a clutch for disconnecting the engine 1 from the drive wheels 11. The second clutch C2 is provided between the secondary shaft 54 and the output shaft 7, and can selectively disconnect the CVT 5 from the output shaft 7. By releasing the second clutch C2, the torque cannot be transmitted between the CVT 5 and the output shaft 7, and the CVT 5 in addition to the engine 1 is disconnected from the drive wheels 11. For example, when the second clutch C2 is engaged, the CVT 5 and the output shaft 7 are connected so as to be able to transmit power, and the secondary shaft 54 and the output shaft 7 rotate integrally. When the second clutch C2 is released, the torque cannot be transmitted between the secondary shaft 54 and the output shaft 7, and the engine 1 and the CVT 5 are disconnected from the drive wheels 11. The second clutch C2 is a hydraulic type. The engaging elements of the second clutch C2 are configured to be frictionally engaged with each other by a hydraulic actuator. The CVT 5 having the above configuration is a belt type CVT (WCVT) with a starting gear.

The output gear 7a and the driven gear 63 are attached to the output shaft 7 so as to rotate integrally. The output gear 7a meshes with the counter driven gear 8a of the counter gear mechanism 8 which is a reduction mechanism. The counter drive gear 8b of the counter gear mechanism 8 meshes with the ring gear 9a of the differential gear 9. The left and right drive wheels 11 and 11 are connected to the differential gear 9 via the left and right axles 10 and 10.

The gear train 6 includes a drive gear 61 that rotates integrally with the sun gear 4S of the forward / backward switching mechanism 4, a counter gear mechanism 62, and a driven gear 63 that rotates integrally with the output shaft 7. The gear row 6 is a reduction mechanism, and the gear ratio (gear ratio) of the gear row 6 is a fixed gear ratio and is set to a predetermined value larger than the maximum gear ratio of the CVT 5. The vehicle Ve is configured to transmit torque from the engine 1 to the drive wheels 11 via the gear train 6 at the time of starting. The gear train 6 functions as a starting gear.

The drive gear 61 meshes with the counter driven gear 62a of the counter gear mechanism 62. The counter gear mechanism 62 includes a counter driven gear 62a, a counter shaft 62b, and a counter drive gear 62c that meshes with the driven gear 63. A counter driven gear 62a is attached to the counter shaft 62b so as to rotate integrally. The counter shaft 62b is arranged in parallel with the input shaft 3 and the output shaft 7. The counter drive gear 62c is configured to be rotatable relative to the counter shaft 62b. Further, a dog clutch S1 for selectively and integrally rotating the counter shaft 62b and the counter drive gear 62c is provided.

The dog clutch S1 includes a pair of meshing engaging elements 64a and 64b and a sleeve 64c that can move in the axial direction. The first engaging element 64a is a hub spline-fitted to the counter shaft 62b. The first engaging element 64a and the counter shaft 62b rotate integrally. The second engaging element 64b is connected to the counter drive gear 62c so as to rotate integrally with the counter drive gear 62c. That is, the second engaging element 64b rotates relative to the counter shaft 62b. The dog clutch S1 is brought into an engaged state when the spline teeth formed on the inner peripheral surface of the sleeve 64c mesh with the spline teeth formed on the outer peripheral surfaces of the engaging elements 64a and 64b. By engaging the dog clutch S1, the drive gear 61 and the driven gear 63 (second path) are connected so that torque can be transmitted. When the engagement between the second engaging element 64b and the sleeve 64c is released, the dog clutch S1 is opened. By releasing the dog clutch S1, the torque cannot be transmitted between the drive gear 61 and the driven gear 63 (second path). The dog clutch S1 is a hydraulic type, and the sleeve 64c is moved in the axial direction by a hydraulic actuator.

The transmission control device (hereinafter, may be simply referred to as “control device”) according to the present embodiment is composed of an electronic control device (hereinafter, ECU: Electronic Control Unit). The ECU is mainly composed of a microcomputer having a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like. The ECU performs a calculation using the input data and the data and the program stored in advance, and outputs the calculation result as a command signal.

Signals from various sensors are input to the ECU. Specifically, the ECU receives signals from various sensors, the speed of the vehicle Ve, the rotation speed of the input shaft 3, that is, the rotation speed of the turbine runner 2b (hereinafter referred to as the turbine rotation speed), the rotation speed of the secondary shaft 54, and the output shaft. The number of revolutions of No. 7, the number of revolutions of the crank shaft 1a (hereinafter, the number of revolutions of the engine), the amount of operation of the accelerator pedal (not shown), the amount of operation of the brake pedal (not shown), and the like are detected. The ECU further sets the gear ratio γ of the CVT 5 and calculates the elapsed time of various states.

The control device uses hydraulic control to engage and disengage the clutches (first clutch C1, second clutch C2, and brake B1) required for stepped speed change. The hydraulic control is realized by driving the solenoid based on the command value calculated by the software mounted on the ECU.

Further, the control device controls to advance the shift according to the relationship between the synchronous rotation speed (output rotation speed x each gear gear ratio) before and after the shift and the turbine rotation speed.

Further, the control device switches the hydraulic control at the time of upshifting between the case where the engine is driven by the accelerator and the case where the engine is driven.

Further, when the engine is in the driven state at the start of the upshift control, the control device has an engaging pressure of the engaging clutch of the stepped speed change as compared with the case of the driven state (engaged hydraulic pressure in the present embodiment). Gradually raise. Further, when the output rotation speed is less than the predetermined rotation speed during the upshift in the driven state, the engagement pressure of the stepped speed change engagement clutch is rapidly increased as compared with the case where the output rotation speed is more than the predetermined rotation speed. Let me.

The vehicle Ve can set two traveling modes, a gear mode and a belt mode. The gear mode is a traveling mode in which power is transmitted from the forward / backward switching mechanism 4 via a gear train, the CVT5 side is cut off so that power cannot be transmitted, the first clutch C1 is engaged, and the second clutch C2 is released. On the other hand, the belt mode is a traveling mode in which power is transmitted via the CVT 5, the gear side is cut off so that power cannot be transmitted, the second clutch C2 is engaged, and the first clutch C1 and the brake B1 are released. The mode.

FIG. 2 is a flowchart showing an outline of processing performed by the transmission control device. This process is related to sweep control of the engagement hydraulic pressure of the engagement clutch (second clutch C2). It should be noted that this process is repeatedly executed while the vehicle is running.

The control device determines whether or not the vehicle is in the upshift in the driven state (step S1). If the upshift is not in progress in the driven state (step S1: No), the control ends.

In step S1, when the driven state is being upshifted (step S1: Yes), the control device determines whether or not the engaging clutch is near synchronous rotation (step S2). When it is not near the synchronous rotation (step S2: No), the control device determines whether or not the output rotation speed is a low rotation speed of less than a predetermined rotation speed (step S3). When the output rotation speed is low (step S3: Yes), the control device proceeds to the process of step S4. When the rotation speed is lower than the predetermined rotation speed, it corresponds to, for example, the engine being in a driving state.

In step S4, the control device rapidly raises the engaging oil pressure of the engaging clutch. Specifically, for example, the engagement hydraulic pressure is sweep-controlled in the same manner as in the driving state (driving region), the engine speed is increased more quickly than in the case where the number of revolutions is equal to or higher than the predetermined number of revolutions in the driven state, and the shift is advanced and controlled. To finish.

In step S3, when the output rotation speed is equal to or higher than the predetermined rotation speed (step S3: No), the control device proceeds to the process of step S5, sets the engaging oil pressure to a constant pressure, makes it stand by, and ends the control.

On the other hand, in step S2, when the engaging clutch is near synchronous rotation (step S2: Yes), the control device proceeds to the process of step S6 and sweeps the engaging hydraulic pressure in the same manner as in the normal driven state. Gradually raise the gear to advance the shift and end the control.

FIG. 3 is a diagram illustrating a problem of the prior art. In the prior art, in the upshift control in the driven state, as shown in FIG. 3A, the turbine rotation speed is waited to decrease, and when the turbine rotation speed is near the synchronous rotation (time t1), the second clutch C2 It was a hydraulic control that raises the engagement hydraulic pressure of the engine to engage it. Therefore, the second clutch C2 waits at a constant pressure until it is near the synchronous rotation, and has almost no torque capacity.

Therefore, as shown in FIG. 3B, when the rotation speed decreases during the upshift control in the driven state and the drive state is reached, the turbine rotation speed does not decrease, so that it is difficult for the gear shift to proceed. Therefore, the shift time becomes long.

On the other hand, according to one embodiment of the present invention, when the output rotation speed is less than the predetermined rotation speed during the upshift in the driven state, the clutch is engaged as compared with the case where the output rotation speed is equal to or more than the predetermined rotation speed. Since the engaging oil pressure of the clutch is quickly increased, it is possible to suppress a long shift time. When the output rotation speed is lower than the predetermined rotation speed, the torque shock is small even if the engagement hydraulic pressure of the engagement clutch is quickly increased, so that the decrease in drivability is suppressed.

1 Engine 2 Torque converter 5 Belt type continuously variable transmission 6 Gear train 7 Output shaft 100 Power transmission mechanism C1 1st clutch C2 2nd clutch

Claims (1)

In a transmission control device equipped with a stepped transmission,
During the upshift, if the engine is driven at the start of the upshift control ,
When it is determined that the engaging clutch is not near the synchronous rotation and the output rotation speed of the stepped transmission is equal to or higher than the predetermined rotation speed, the engaging pressure of the engaging clutch is made to stand by at a constant pressure.
When it is determined that the engaging clutch is near the synchronous rotation, or even when the engaging clutch is not near the synchronous rotation, the output rotation speed of the stepped transmission is less than the predetermined rotation speed. If it is determined that, to the upper temperature the engagement pressure of the engagement clutch,
When it is determined that the output rotation speed of the stepped transmission is less than the predetermined rotation speed and the engagement pressure of the engagement clutch is increased, it is determined that the engagement clutch is in the vicinity of the synchronous rotation. control device for a transmission, characterized in that to quickly raise the engagement pressure of the engagement clutch as compared with the case of increasing the engagement pressure of the engagement clutch.

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