JP6984412B2 - Transmission control device - Google Patents

Description

The present invention relates to a transmission control device.

Conventionally, in a shift control device of a vehicle having an automatic transmission, when the start of the inertia phase cannot be detected based on the turbine rotation speed, a technique for forcibly ending the shift operation after a predetermined time has elapsed has been known. For example, see Patent Document 1).

Japanese Unexamined Patent Publication No. 2007-127162

In the above-mentioned conventional technique, the shift operation cannot be terminated until a preset time has elapsed. For this reason, if the above-mentioned control is performed when the vehicle is stopped during the upshift shift, the downshift shift is not performed until a predetermined time has elapsed even if there is a start request immediately after the vehicle is stopped, so that the necessary driving force is obtained at the time of starting. Can't.

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 promptly responding to a new shift request after the shift is completed.

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 clutch for stepped speed change, during a shift involving engagement of the clutch. In a certain case, when the output rotation speed of the transmission is equal to or less than a predetermined rotation speed and the engaging hydraulic pressure is equal to or higher than a predetermined value for a predetermined time or longer, it is determined that the shift has been completed. ..

According to the present invention, when shifting with clutch engagement is in progress, a state in which the output rotation speed of the transmission is equal to or lower than a predetermined rotation speed and the engaging hydraulic pressure is equal to or higher than a predetermined value has elapsed for a predetermined time or longer. At this time, since it is determined that the shift has been completed, it is possible to promptly respond to a new shift request after the shift is completed.

FIG. 1 is a skeleton diagram schematically showing a vehicle equipped 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 the operation of processing performed by the transmission control device according to the embodiment of the present invention.

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 equipped 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 wheel 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 is provided with 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. The second pinion gear 4P ₂ is provided with 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 unit and the gear train 6 which is a stepped transmission unit 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 a 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 thrust to move 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, 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, 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 hydraulic. The engagement 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 / reverse switching mechanism 4, a counter gear mechanism 62, and a driven gear 63 that rotates integrally with the output shaft 7. The gear train 6 is a reduction mechanism, and the gear ratio (gear ratio) of the gear train 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 be moved 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. That is, the second engaging element 64b rotates relative to the counter shaft 62b. 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, so that the dog clutch S1 is in an engaged state. By engaging the dog clutch S1, the drive gear 61 and the driven gear 63 (second path) are connected so as to be able to transmit torque. 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 transmission between the drive gear 61 and the driven gear 63 (second path) is cut off so as not to be able to transmit torque. The dog clutch S1 is hydraulic, and the sleeve 64c is moved in the axial direction by the 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 uses signals from various sensors to determine 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 rotation speed of 7, the rotation speed of the crank shaft 1a (hereinafter referred to as the engine rotation speed), the operation amount of the accelerator pedal (not shown), the operation amount 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.

When the control device is in the process of shifting with the engagement of the friction clutch, a state in which the output rotation speed of the transmission is equal to or lower than the predetermined rotation speed and the engagement hydraulic pressure is equal to or higher than the predetermined value has elapsed for a predetermined time or longer. At that time, it is determined that the shift has been completed.

The control device hydraulically controls engagement and disengagement of the clutch required for stepped shifting. Hydraulic pressure control is realized by driving a solenoid based on a command value calculated by 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 × each gear shift ratio) before and after the shift and the turbine rotation speed. Further, the control device can control the shift at an extremely low rotation speed (output rotation speed = 0 rpm).

The vehicle Ve can set two driving 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 the processing performed by the transmission control device. If the vehicle is shifting (step S1: Yes) and the output rotation is extremely low (rotation speed = 0 ppm) (step S2: Yes), the control device shifts to the process of step S3 and outputs. If the rotation is not extremely low (step S2: No), the process proceeds to step S4. The shift referred to here is, for example, an upshift or a manual downshift.

In step S3, when the control device is controlling coast down or down when stopped (step S3: Yes), if the control face of the control device is in the shift end phase (step S5: Yes), the control device ends the shift. (Step S6), and the series of processes is terminated.

In step S5, if the control phase is not the shift end phase (step S5: No), when the shift end guard time has elapsed (step S7: Yes), the control device shifts to step S6. In step S7, when the shift end guard time has not elapsed (step S7: No), the control device returns to the process of step S2.

In step S3, when the control device is not controlling the coast down or the down when stopped (step S3: No), the state of "the turbine rotation speed is equal to or less than the predetermined rotation speed and the engagement hydraulic pressure is equal to or more than the predetermined value" is set. If it continues for a predetermined time (step S8: Yes), the control device shifts to the process of step S6. In step S8, when the state of "the turbine rotation speed is equal to or less than the predetermined value and the engaging hydraulic pressure is equal to or higher than the predetermined value" is not continued for a predetermined time (step S8: No), the control device proceeds to the process of step S7. Transition. The condition regarding the turbine rotation speed is a condition for determining whether or not the clutch is engaged even when the output rotation speed is 0 rpm. Further, the condition regarding the engaging hydraulic pressure of the clutch is a condition for determining whether or not the hydraulic pressure that the clutch can sufficiently engage is commanded. When the state satisfying these two conditions continues for a predetermined time, the control device determines that the shift is completed.

In step S4, when the turbine rotation speed is a value near the synchronous rotation speed (step S4: Yes), the control device shifts to the process of step S6. On the other hand, when the turbine rotation speed is not a value near the synchronous rotation speed (step S4: No), the control device shifts to the process of step S7.

In step S1, if the vehicle is not shifting (step S1: No), the control device shifts to the process of step S6.

As described above, compared to the conventional technology, the control device ends the shift by the turbine rotation and the clutch engaging hydraulic pressure, as opposed to the shift when the output rotation is extremely low rotation (including when the vehicle is stopped). The condition (step S8) is added.

FIG. 3 is a diagram illustrating the operation of processing performed by the transmission control device according to the present embodiment. For example, when the vehicle is stopped during an upshift when multiple shifts are prohibited or a manual upshift is performed, the synchronous rotation speed is unknown and the control device cannot determine the end. For such a shift at extremely low rotation speed, the conventional control device determines the end when the shift end guard time has elapsed and performs downshift output. On the other hand, in the present embodiment, a predetermined time elapses in a state where both the two conditions of (1) turbine rotation that can be determined to be in the clutch engaged state and (2) hydraulic pressure command sufficient for clutch engagement are satisfied. Since the end of the shift is determined when the shift is completed, the downshift delay time can be minimized.

According to one embodiment of the present invention described above, when the gear shifting is accompanied by the engagement of the friction clutch, the output rotation speed of the transmission is equal to or less than the predetermined rotation speed, and the engagement hydraulic pressure is equal to or more than the predetermined value. When the predetermined time or more has elapsed, it is determined that the shift has been completed, so that it is possible to promptly respond to a new shift request after the shift is completed.

1 Engine 2 Torque converter 2b Turbine runner 5 Belt type continuously variable transmission 100 Power transmission mechanism C1 1st clutch C2 2nd clutch

Claims (1)

In a transmission control device equipped with a stepped speed change clutch
In the case of shifting with clutch engagement, when the input shaft rotation speed of the transmission is equal to or less than the predetermined rotation speed and the engaging hydraulic pressure is equal to or higher than the predetermined value for a predetermined time or longer, the shifting is performed. A transmission control device characterized in that it is determined to be finished.

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