JP2021173349A - Hydraulic pressure control device - Google Patents

Abstract

To provide a hydraulic pressure control device, for an automatic transmission, capable of restraining a delay in a vehicle start due to a delay in supply of hydraulic pressure.SOLUTION: A hydraulic pressure control device is for an automatic transmission (20) which shifts gears by switching between engagement and disengagement of a plurality of friction engagement elements (22). The hydraulic pressure control device comprises: solenoid valves (34) which are installed on respective friction engagement elements and switches between engagement and disengagement thereof by switching between supplying and non-supplying of hydraulic pressure to the respective friction engagement elements; and a control device (12a) which switches between supplying and non-supplying of the hydraulic pressure to the respective friction engagement elements by applying predetermined control current to the solenoid valves. The control device is adapted to supply sticking prevention current to the solenoid valve arranged corresponding to the friction engagement element (22e) engaged at a time of vehicle start among the respective friction engagement elements after a start-up of an engine of the vehicle mounted with the automatic transmission and before the vehicle start.SELECTED DRAWING: Figure 10

Description

The present invention relates to a hydraulic control device, and more particularly to a hydraulic control device of an automatic transmission that shifts gears by switching between fastening and non-fastening of a plurality of friction fastening elements.

Japanese Patent No. 5761337 (Patent Document 1) describes a control method and a control device for an automatic transmission, and an automatic transmission system. The automatic transmission described here includes a plurality of friction fastening elements, and by selectively fastening these friction fastening elements, the power transmission path in the automatic transmission can be changed to change the speed change stage. Is configured to be changeable. That is, when changing the shift stage of the automatic transmission from one shift stage to another, some of the friction fastening elements that have been fastened are released, and the other friction fastening elements that have been opened are released. By fastening, the power transmission path in the automatic transmission is changed.

Further, in general, an automatic transmission operates an electromagnetic valve provided corresponding to a friction fastening element to be fastened at the time of shifting, and moves the spool by this solenoid valve to apply hydraulic pressure to the friction fastening element. Supply and conclude this. Further, the solenoid valve provided corresponding to the friction fastening element to be opened (non-fastened) is operated, the supply of the hydraulic pressure to the friction fastening element is stopped, and the solenoid valve is opened. When the vehicle is started, the vehicle is started by fastening friction fastening elements such as 1st speed and reverse that constitute a shift stage at the time of starting the automatic transmission. In the automatic transmission described in Patent Document 1, the timing at which the friction fastening element to be fastened and the solenoid valve provided corresponding to the friction fastening element to be opened are accurately operated when the vehicle starts or shifts is accurately performed. We are precharging so that they are aligned.

Japanese Patent No. 5761337

However, the spool moved by the solenoid valve provided corresponding to each friction fastening element for switching the automatic transmission may stick and become poorly moved. In this way, if the spool is stuck, after the control signal is sent to the solenoid valve, the solenoid valve is activated and the time until the spool actually moves becomes longer, and it actually becomes the friction fastening element to be fastened. It takes a long time for the oil to be supplied to the vehicle. When such spool sticking occurs, as in the invention described in Patent Document 1, even if precharging is executed, the fastening of the friction fastening element is delayed, and the responsiveness of shifting by the automatic transmission is poor. Become. Further, if the spool is stuck when the vehicle is started, there is a problem that the spool cannot be started smoothly when the driver intends to do so.

Therefore, an object of the present invention is to provide a hydraulic control device for an automatic transmission capable of suppressing a delay in starting a vehicle based on a delay in hydraulic supply.

In order to solve the above-mentioned problems, the present invention is a hydraulic control device for an automatic transmission that shifts gears by switching between fastening and non-fastening of a plurality of friction fastening elements, and for each friction fastening element. A solenoid valve that switches between fastening and non-fastening of each friction fastening element by switching the supply / non-supply of hydraulic pressure to each friction fastening element, and supplying a predetermined control current to these solenoid valves. The control device has a control device for switching the supply / non-supply of oil pressure to each friction fastening element, and the control device has each friction fastening element after the engine of the vehicle equipped with the automatic transmission is started and before the vehicle starts. Of these, it is characterized in that it is configured to supply an anti-sticking current to a solenoid valve provided corresponding to a friction fastening element to be fastened when the vehicle starts.

In the present invention configured as described above, the control device supplies a predetermined control current to the solenoid valve. Solenoid valves are provided for each friction fastening element of the automatic transmission, and by switching the supply / non-supply of hydraulic pressure to each friction fastening element, each friction fastening element is based on the control current of the control device. Toggle between fastening and non-fastening. Further, the control device supplies a sticking prevention current to the solenoid valve provided corresponding to the friction fastening element to be fastened at the time of starting among the friction fastening elements after the vehicle engine is started and before the start.

According to the present inventor, the occurrence of the delay in supplying hydraulic pressure to the friction fastening element to be fastened is caused by the sticking of the parts driven by the solenoid valve, and the occurrence of this sticking is to supply the sticking prevention current to the solenoid valve. It was found that it can be suppressed by. That is, the present inventor has found that if the friction fastening element provided in the automatic transmission is not fastened for a long time when the vehicle is parked or stopped, sticking occurs due to this. According to the present invention configured as described above, the control device is provided corresponding to the friction fastening element to be fastened at the time of starting among the friction fastening elements after the engine of the vehicle is started and before the start. A sticking prevention current is supplied to the solenoid valve, which suppresses the occurrence of sticking. That is, by supplying the anti-sticking current to the solenoid valve, the sticking of the parts driven by the solenoid valve is eliminated, and when the driver performs the start operation, the vehicle can be started smoothly. Since the hydraulic pump is operating after the vehicle engine is started, when the anti-sticking current is supplied to the solenoid valve, the friction fastening element provided corresponding to the solenoid valve is brought into the fastened state, but sticking. Since the preventive current is supplied before the vehicle starts, the vehicle is not started by fastening the friction fastening elements.

In the present invention, preferably, the anti-sticking current supplied after the engine of the vehicle is started and before the vehicle starts is set to a current lower than the control current.
According to the present invention configured in this way, since the anti-sticking current supplied after the engine is started and before the vehicle starts is set to a current lower than the control current, power consumption due to the supply of the anti-sticking current is set. Can be suppressed, and the occurrence of sticking can be suppressed with low power consumption.

In the present invention, preferably, at least one of the solenoid valves is configured such that when a control current is supplied, the corresponding friction fastening elements are switched to the fastening state.

According to the present invention configured as described above, when the control current is supplied, the at least one solenoid valve is brought into the fastening state by supplying the hydraulic pressure to the friction fastening element provided corresponding to the control current. It is possible to make the non-fastened state without passing a current through the motor, and the current consumption can be reduced. Further, since the anti-sticking current supplied after the engine is started and before the vehicle starts is only required to pass a minute current, the amount of current consumed to suppress the sticking can be further reduced.

In the present invention, preferably, at least one of the plurality of friction fastening elements is a zero-touch clutch in which the clearance between the friction plates constituting the friction fastening element is substantially zero, and is equipped with an automatic transmission. When the vehicle starts, a plurality of friction engaging elements including a zero-touch clutch are engaged, and the control device is configured to supply an anti-sticking current only to the solenoid valve provided corresponding to the zero-touch clutch. ing.

Since the clearance between the friction plates of the zero-touch clutch is substantially zero, by using this as a friction fastening element for starting the vehicle, the responsiveness of starting the vehicle can be improved. Further, according to the present invention configured as described above, the anti-sticking current is supplied only to the solenoid valve provided corresponding to the zero-touch clutch before the vehicle starts, so that the anti-sticking current is supplied. This makes it possible to reliably prevent the vehicle from being started.

In the present invention, preferably, the control device uses a friction engaging element other than the zero touch clutch that is engaged when the vehicle equipped with the automatic transmission is started after the supply of the anti-sticking current to the zero touch clutch is stopped. To conclude.

According to the present invention configured as described above, after stopping the supply of the anti-sticking current to the zero-touch clutch, the friction engaging element other than the zero-touch clutch that is engaged at the time of starting is engaged. Therefore, when starting the vehicle, the vehicle can be started only by supplying a control current to the solenoid valve provided corresponding to the zero touch clutch, and the responsiveness of the vehicle start can be made extremely good. can.

According to the hydraulic control device for the automatic transmission of the present invention, it is possible to suppress the delay in starting the vehicle due to the delay in the supply of hydraulic pressure.

It is a block diagram which shows the whole automatic transmission system provided with the hydraulic control device by embodiment of this invention. It is a figure which shows the schematic structure of the automatic transmission which the shift stage is switched by the hydraulic control device by embodiment of this invention. It is a clutch / brake-shift gear correspondence table in the automatic transmission which the shift gear is switched by the hydraulic control device by embodiment of this invention. It is a figure which shows the hydraulic control circuit provided in the hydraulic control device by embodiment of this invention. FIG. 5 is a cross-sectional view of a fastening hydraulic control valve in an energized state in the hydraulic control device according to the embodiment of the present invention. FIG. 5 is a cross-sectional view of a fastening hydraulic control valve in a non-energized state in the hydraulic control device according to the embodiment of the present invention. It is a graph which shows an example of the operation of the flood control valve for fastening when sticking occurs. It is a figure which shows an example of the sticking prevention current waveform supplied to the coil of the fastening hydraulic control valve in the hydraulic control device according to the embodiment of this invention. It is a graph which shows the relationship between the electric current supplied to the fastening hydraulic control valve, and the hydraulic pressure supplied to the friction fastening element provided corresponding to this in the hydraulic control device according to the embodiment of the present invention. It is a flowchart which shows the process executed by the control device of ECU in the hydraulic control device of embodiment of this invention.

Next, the hydraulic control device for the automatic transmission according to the embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an entire automatic transmission system including a hydraulic control device according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of an automatic transmission whose gears are switched by the hydraulic control device according to the embodiment of the present invention. FIG. 3 is a clutch / brake-shift gear correspondence table in an automatic transmission in which the shift gear is switched by the hydraulic control device according to the embodiment of the present invention. FIG. 4 is a diagram showing a flood control circuit provided in the flood control device according to the embodiment of the present invention.

As shown in FIG. 1, the automatic transmission system 1 provided with the hydraulic control device according to the embodiment of the present invention includes a vehicle speed sensor 2, a throttle opening sensor 4, a turbine rotation speed sensor 6, and an ATF hot water temperature sensor 8. And a fastening hydraulic sensor 10. Further, the automatic transmission system 1 shifts gears by the ECU 12 to which the signals from the above sensors are input, the hydraulic control circuit 14 controlled by the control signal from the ECU 12, and the hydraulic pressure supplied from the hydraulic control circuit 14. It has an automatic transmission 20 whose speed can be switched.

The vehicle speed sensor 2 is configured to detect the vehicle speed of a vehicle (not shown) equipped with the automatic transmission system 1 and input a detection signal to the ECU 12.
The throttle opening sensor 4 is configured to detect the throttle opening of the engine (not shown) of the vehicle (not shown) equipped with the automatic transmission system 1 and input the detection signal to the ECU 12. There is.
The turbine rotation speed sensor 6 detects the rotation speed of the turbine of the turbocharger (not shown) provided in the engine of the vehicle in which the automatic transmission system 1 is mounted, and inputs the detection signal to the ECU 12. It is configured.

The ATF hot water temperature sensor 8 is configured to detect the temperature of the hydraulic hydraulic oil (Automatic Transmission Fluid) supplied to the automatic transmission 20 and input the detection signal to the ECU 12.
The fastening hydraulic sensor 10 is configured to detect the temperature of the hydraulic oil supplied to each friction fastening element 22 of the automatic transmission 20 via the hydraulic control circuit 14 and input the detection signal to the ECU 12. .. As will be described later, the automatic transmission 20 includes a plurality of friction fastening elements 22, and a plurality of fastening hydraulic sensors 10 are provided so as to correspond to each of the friction fastening elements 22. The pressure of the hydraulic oil supplied to each friction fastening element 22 is detected by the fastening hydraulic sensor 10 provided corresponding to each friction fastening element 22, and the detection signal is input to the ECU 12.

The ECU (Electric Control Unit) 12 is configured to control a vehicle engine (not shown), an automatic transmission 20, and the like based on detection signals input from each sensor. Specifically, the ECU 12 calculates an appropriate shift stage of the automatic transmission 20 based on the detection signals detected by the vehicle speed sensor 2, the throttle opening sensor 4, and the turbine rotation speed sensor 6, and based on this. Is configured to control the automatic transmission 20. That is, the ECU 12 engages / does not engage the first to fifth friction fastening elements 22a to 22e provided in the automatic transmission 20 so that the shift stage is realized when an appropriate shift stage is calculated. To switch. Further, the fastening / non-fastening of the first to fifth friction fastening elements 22a to 22e is switched by the supply / non-supply of hydraulic pressure to the friction fastening elements. Therefore, the ECU 12 controls the first to fifth fastening hydraulic control valves 16a to 16e and the flow rate control valve 18 provided in the hydraulic control circuit 14, and thereby the first to fifth friction fastening elements 22a to. Switch between fastening and non-fastening of 22e.

That is, the first to fifth fastening hydraulic control valves 16a to 16e are provided corresponding to the first to fifth friction fastening elements 22a to 22e provided in the automatic transmission 20, respectively, and the ECU 12 is provided with the ECU 12. By controlling the fastening hydraulic control valve corresponding to the friction fastening element to be switched, fastening / non-fastening is switched. In the following, the first to fifth fastening hydraulic control valves 16a to 16e are collectively referred to as the fastening hydraulic control valves 16, and the first to fifth friction fastening elements 22a to 22e are collectively referred to. Therefore, it is simply referred to as a friction fastening element 22. Here, the ECU 12 is composed of a microprocessor, various interface circuits, a memory, software for operating these (these are not shown above), and the like. A part of the circuits of the ECU 12 configured in this way supplies / does not supply hydraulic pressure to each friction fastening element 22 by supplying a predetermined control current to the solenoid valve of each fastening hydraulic control valve 16. Functions as a control device 12a for switching between. Further, the solenoid valve provided in each fastening hydraulic control valve 16 and the control device 12a function as a hydraulic control device according to the embodiment of the present invention. The control device 12a may be configured by hardware separate from the ECU 12 for controlling the vehicle engine (not shown) or the like.

Next, with reference to FIGS. 2 and 3, the configuration of an automatic transmission in which the shift stage is switched by the hydraulic control device according to the embodiment of the present invention will be described.
In the present embodiment, the automatic transmission 20 is a vertical automatic transmission mounted on a vehicle such as an FR vehicle. As shown in FIG. 2, the automatic transmission 20 includes a transmission case 20a, an input shaft 20b inserted into the transmission case 20a from a vehicle drive source (left side in the figure), and the inside of the transmission case 20a. It is provided with an output shaft 20c protruding from the counter drive source side (right side in the figure). The input shaft 20b and the output shaft 20c are arranged on the same axis along the front-rear direction of the vehicle, and the input shaft 20b is located on the front side of the vehicle and the output shaft 20c is located on the rear side of the vehicle. The automatic transmission 20 is arranged. Therefore, in the following, the drive source side (left side in the figure) may be referred to as the front side, and the anti-drive source side (right side in the figure) may be referred to as the rear side.

On the axis of the input shaft 20b and the output shaft 20c, the first, second, third, and fourth planetary gear sets (hereinafter, simply referred to as "gear sets") PG1, PG2, PG3, and PG4 are on the front side (drive source side). They are arranged in order from.

The first clutch CL1 is arranged on the front side of the first gear set PG1 in the transmission case 20a, the second clutch CL2 is arranged on the front side of the first clutch CL1, and the third clutch CL2 is arranged on the front side of the second clutch CL2. The clutch CL3 is arranged. Further, the first brake BR1 is arranged on the front side of the third clutch CL3, and the second brake BR2 is arranged on the outer side in the radial direction of the third gear set PG3. In this way, the friction fastening elements (first to third clutches CL1 to CL3 and the first and second brakes BR1 and BR2) of the automatic transmission 20 are from the front side (drive source side) to the first brake BR1 and the first brake BR1 and the first. The three clutches CL3, the second clutch CL2, the first clutch CL1, and the second brake BR2 are arranged in the axial direction in this order.

The first to fourth gear sets PG1 to PG4 are all single pinion types in which the pinion supported by the carrier directly meshes with the sun gear and the ring gear. The first gear set PG1 has a first sun gear S1, a first ring gear R1, and a first carrier C1 as rotating elements. The second gear set PG2 has a second sun gear S2, a second ring gear R2, and a second carrier C2 as rotating elements. The third gear set PG3 has a third sun gear S3, a third ring gear R3, and a third carrier C3 as rotating elements. The fourth gear set PG4 has a fourth sun gear S4, a fourth ring gear R4, and a fourth carrier C4 as rotating elements.

The first gear set PG1 is a double sun gear type in which the first sun gear S1 is divided into two in the axial direction. That is, the first sun gear S1 has a front side first sun gear S1a arranged on the front side in the axial direction and a rear side first sun gear S1b arranged on the rear side. Since the pair of first sun gears S1a and S1b have the same number of teeth and mesh with the same pinion supported by the first carrier C1, the rotation speeds of these first sun gears S1a and S1b are always equal. That is, the pair of front and rear first sun gears S1a and S1b always rotate at the same speed, and when one rotation is stopped, the other rotation is also stopped.

In the automatic transmission 20, the first sun gear S1 (more specifically, the rear first sun gear S1b) and the fourth sun gear S4 are always connected, and the first ring gear R1 and the second sun gear S2 are always connected to each other. The 2 carrier C2 and the 4th carrier C4 are always connected, and the 3rd carrier C3 and the 4th ring gear R4 are always connected. The input shaft 20b is always connected to the first carrier C1, and the output shaft 20c is always connected to the fourth carrier C4. Specifically, the input shaft 20b is connected to the first carrier C1 via a power transmission member 24a that passes between the pair of front and rear first sun gears S1a and S1b. The rear first sun gear S1b and the fourth sun gear S4 are connected to each other via a power transmission member 24b. The fourth carrier C4 and the second carrier C2 are connected to each other via a power transmission member 24c.

The first clutch CL1 connects and disconnects the input shaft 20b and the first carrier C1 from the third sun gear S3. The second clutch CL2 connects and disconnects the first ring gear R1 and the second sun gear S2 from the third sun gear S3. The third clutch CL3 connects and disconnects the second ring gear R2 and the third sun gear S3.

Specifically, the first clutch CL1 transmits power to the rotatable inner holding member coupled to the first carrier C1, the hub-side friction plate engaged with the outer peripheral surface of the inner holding member, and the third sun gear S3. To press-contact the rotatable outer holding member connected via the members 24d and 24e, the drum-side friction plate engaged with the inner peripheral surface of the outer holding member, and the hub-side friction plate and the drum-side friction plate. It has a piston P1 that is driven forward and backward in the axial direction. A hydraulic chamber F1 into which the oil supply supplied from the hydraulic control circuit 14 is introduced is defined at a position adjacent to the piston P1, and the hub-side friction plate and the hub-side friction plate and the above-mentioned friction plate on the hub side are formed according to the supply and discharge of the oil pressure to the hydraulic chamber F1. The friction plate on the drum side is pressed or released. Then, by the pressure welding or release of the pressure welding, the inner holding member and the outer holding member are connected or separated from each other, and accordingly, the input shaft 20b, the first carrier C1, and the third sun gear S3 are disconnected and connected.

The second clutch CL2 includes a rotatable inner holding member coupled to the third sun gear S3 via power transmission members 24d and 24e, a hub-side friction plate engaged with the outer peripheral surface of the inner holding member, and a first. A rotatable outer holding member coupled to the ring gear R1 and the second sun gear S2 via a power transmission member 24f, a drum-side friction plate engaged with the inner peripheral surface of the outer holding member, a hub-side friction plate and a drum. It has a piston P2 that is driven to move forward and backward in the axial direction in order to press contact with the side friction plate. A hydraulic chamber F2 into which the oil supply supplied from the hydraulic control circuit 14 is introduced is defined at a position adjacent to the piston P2, and the hub-side friction plate and the hub-side friction plate are formed according to the supply and discharge of the oil pressure to the hydraulic chamber F2. By pressing or releasing the friction plate on the drum side, the first ring gear R1 and the second sun gear S2 are disconnected from the third sun gear S3.

The third clutch CL3 includes a rotatable inner holding member coupled to the third sun gear S3 via power transmission members 24d and 24e, a hub-side friction plate engaged with the outer peripheral surface of the inner holding member, and a second clutch. A rotatable outer holding member coupled to the ring gear R2 via a power transmission member 24g, a drum-side friction plate engaged with the inner peripheral surface of the outer holding member, and a hub-side friction plate and a drum-side friction plate. It has a piston P3 that is driven forward and backward in the axial direction for pressure contact. A hydraulic chamber F3 into which the oil supply supplied from the hydraulic control circuit 14 is introduced is defined at a position adjacent to the piston P3, and the hub-side friction plate and the hub-side friction plate and the friction plate on the hub side are formed according to the supply and discharge of the oil pressure to the hydraulic chamber F3. By pressing or releasing the friction plate on the drum side, the second ring gear R2 and the third sun gear S3 are disconnected and disconnected.

The first brake BR1 connects and disconnects the transmission case 20a and the first sun gear S1 (more specifically, the front first sun gear S1a). The second brake BR2 connects and disconnects the transmission case 20a and the third ring gear R3.

Specifically, the first brake BR1 includes a rotatable inner holding member coupled to the front first sun gear S1a via a power transmission member 24h, and a hub-side friction plate engaged with the outer peripheral surface of the inner holding member. , To press-contact the non-rotatable outer holding member coupled to the transmission case 20a, the drum-side friction plate engaged with the inner peripheral surface of the outer-holding member, and the hub-side friction plate and the drum-side friction plate. It has a piston P4 that is driven forward and backward in the axial direction. A hydraulic chamber F4 into which the oil supply supplied from the hydraulic control circuit 14 is introduced is defined at a position adjacent to the piston P4, and the hub side friction plate and the hub side friction plate and the above-mentioned friction plate on the hub side are defined according to the supply and discharge of the oil pressure to the hydraulic chamber F4. By pressing or releasing the friction plate on the drum side, the transmission case 20a and the first sun gear S1 are disconnected and disconnected.

The second brake BR2 is a non-rotatable inner holding member coupled to the third ring gear R3, a hub-side friction plate engaged with the outer peripheral surface of the inner holding member, and a transmission case 20a. It has an outer holding member, a drum-side friction plate engaged with the inner peripheral surface of the outer holding member, and a piston P5 that is driven to move forward and backward in the axial direction in order to press-contact the hub-side friction plate and the drum-side friction plate. doing. A hydraulic chamber F5 into which the oil supply supplied from the hydraulic control circuit 14 is introduced is defined at a position adjacent to the piston P5, and the hub-side friction plate and the hub-side friction plate are formed according to the supply and discharge of the oil pressure to the hydraulic chamber F5. By pressing or releasing the friction plate on the drum side, the transmission case 20a and the third ring gear R3 are disconnected and disconnected.

The transmission case 20a has an annular vertical wall portion W1 extending radially inward from the inner peripheral surface of the transmission case 20a at an axial position between the first brake BR1 and the third clutch CL3, and also has a vertical wall. It has a cylindrical wall portion W2 extending rearward from the inner peripheral end of the portion W1. The cylindrical wall portion W2 is formed so as to extend concentrically along the inner peripheral surface of the power transmission member 24e.

Three housings arranged in the axial direction are formed on the radial outer side of the power transmission member 24e, and the pistons P1 of the first clutch CL1, the second clutch CL2, and the third clutch CL3 are formed in these three housings. P2 and P3 are housed respectively.

The vertical wall portion W1, the cylindrical wall portion W2, and the power transmission member 24e are used to supply hydraulic pressure to the hydraulic chambers F1, F2, and F3 of the first clutch CL1, the second clutch CL2, and the third clutch CL3, respectively. An oil channel is formed. Specifically, oil passages a are formed in the vertical wall portion W1 and the cylindrical wall portion W2, and oil passages b, c, and d are formed in the power transmission member 24e. Then, oil is supplied to the hydraulic chamber F1 of the first clutch CL1 through the oil passage a and the oil passage b, and oil is supplied to the hydraulic chamber F2 of the second clutch CL2 through the oil passage a and the oil passage c, and the oil passage a and the oil passage c Flood is supplied to the hydraulic chamber F3 of the third clutch CL3 through the oil passage d.

Although not shown, the communication portions between the oil passage a and the oil passages b, c, and d between the outer peripheral surface of the cylindrical wall portion W2 and the inner peripheral surface of the power transmission member 24e are each sealed by a seal ring. There is.

The piston P4 of the first brake BR1 is housed in a housing formed on the front side of the vertical wall portion W1. An oil passage e directly communicates with the hydraulic chamber F4 partitioned by the housing from the outside of the transmission case 20a.

The piston P5 of the second brake BR2 is housed in a housing fitted to the inner peripheral surface of the rear part of the transmission case 20a. An oil passage f directly communicates with the hydraulic chamber F5 partitioned by the housing from the outside of the transmission case 20a.

According to the automatic transmission 20 having the above configuration, as shown in the fastening table of FIG. 3, five friction fastening elements (CL1, CL2, CL3) are based on the control of the supply and discharge of the hydraulic pressure to the hydraulic chambers F1 to F5. , BR1, BR2) are selectively fastened to form one of forward 1st to 8th speeds and backward speeds. Further, as shown in FIG. 3, when the vehicle is started in the first forward speed, the first clutch CL1 which is the first friction fastening element 22a, the first brake BR1 which is the fourth friction fastening element 22d, and The second brake BR2, which is the fifth friction fastening element 22e, is fastened. That is, the first clutch CL1, the first brake BR1, and the second brake BR2 constitute a start shift stage of the first forward speed. On the other hand, when the vehicle is started at a reverse speed, the third clutch CL3 which is the third friction fastening element 22c, the first brake BR1 which is the fourth friction fastening element 22d, and the fifth friction fastening element 22e are used. A second brake BR2 is fastened. That is, the third clutch CL3, the first brake BR1, and the second brake BR2 form a reverse speed start gear.

Further, in the present embodiment, the second brake BR2 of the automatic transmission 20 is configured as a "zero touch clutch". Here, in the present specification, the "zero touch clutch" means a clutch or a brake in which the friction plates (drive plate and driven plate) constituting the second brake BR2, which is a friction fastening element, are in a "zero touch state". do. Further, the "zero touch state" means a state in which the clearance between the friction plates constituting the friction fastening element is narrowed until just before the friction fastening. Therefore, in the present embodiment, it can be said that the clearance between the friction plates constituting the second brake BR2 of the automatic transmission 20 is substantially zero. Therefore, in the present embodiment, the second brake BR2, which is a friction fastening element, is brought into the fastening state only by supplying a small amount of hydraulic pressure, so that extremely high responsiveness can be obtained.

Next, the hydraulic control circuit 14 in the hydraulic control device according to the embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 4, the hydraulic control circuit 14 supplies the five fastening hydraulic control valves 16a to 16e, which are the first to fifth fastening hydraulic control valves, and the fastening hydraulic control valves 16a to 16e. It has a flow rate control valve 18 for controlling the flow rate of the hydraulic oil to be operated. Further, the hydraulic control circuit 14 includes a hydraulic pump 26 that supplies hydraulic oil to the flow control valve 18, and an oil pan 28 that stores hydraulic oil that is sucked up by the hydraulic pump 26.

The hydraulic pump 26 is configured to suck up the hydraulic oil stored in the oil pan 28 and supply it to the flow rate control valve 18. The hydraulic oil whose flow rate is adjusted by the flow rate control valve 18 is supplied to the first fastening hydraulic control valve 16a to the fifth fastening hydraulic control valve 16e, respectively. Further, the flow rate control valve 18 and the hydraulic pump 26 are controlled by the ECU 12 based on the detection signals of the ATF hot water temperature sensor 8 (FIG. 1) and the like, and supply appropriate oil pressure to each friction fastening element.

Here, as shown in FIG. 4, the first engagement hydraulic control valve 16a is connected to the first clutch CL1 which is the first friction engagement element 22a of the automatic transmission 20. Further, the second fastening hydraulic control valve 16b is connected to the second clutch CL2 which is the second friction fastening element 22b, and the third fastening hydraulic control valve 16c is the third friction fastening element 22c. It is connected to the third clutch CL3. Further, the fourth fastening hydraulic control valve 16d is connected to the first brake BR1 which is the fourth friction fastening element 22d, and the fifth fastening hydraulic control valve 16e is the fifth friction fastening element 22e. It is connected to the second brake BR2.

Therefore, for example, when the first fastening hydraulic control valve 16a is energized, the first clutch CL1 which is the first friction fastening element 22a of the automatic transmission 20 corresponding to this is hydraulically charged. Is supplied and this is concluded. Further, when the energization of the first fastening hydraulic control valve 16a is stopped, the hydraulic pressure in the first clutch CL1 is released, the fastening is released, and the hydraulic oil presses the first fastening hydraulic control valve 16a. It is collected in the oil pan 28 via the oil pan 28. In this way, by energizing the first to fifth fastening hydraulic control valves 16a to 16e provided corresponding to the first to fifth friction fastening elements 22a to 22e, each friction fastening element can be attached. Can be fastened. Further, the first to fifth friction fastening elements 22a to 22e are provided with first to fifth fastening hydraulic sensors 10a to 10e, and the oil pressure supplied to each friction fastening element is detected. ..

Next, the configuration and operation of the fastening hydraulic control valve provided in the hydraulic control device according to the embodiment of the present invention will be described with reference to FIGS. 5 to 9.
FIG. 5 is a cross-sectional view of the fastening hydraulic control valve in the energized state. FIG. 6 is a cross-sectional view of a fastening hydraulic control valve in a non-energized state. FIG. 7 is a graph showing an example of the operation of the fastening hydraulic control valve when sticking occurs. FIG. 8 is a diagram showing an example of a sticking prevention current waveform supplied to the coil of the fastening hydraulic control valve. FIG. 9 is a graph showing the relationship between the current supplied to the fastening hydraulic control valve and the hydraulic pressure supplied to the friction fastening element provided corresponding to the current.

As shown in FIG. 5, the fifth fastening hydraulic control valve 16e has a cylinder 30, a spool 32 that slides in the cylinder 30, and a solenoid valve 34 that drives the spool. Although the configuration of the fifth fastening hydraulic control valve 16e will be described here, all of the first to fifth fastening hydraulic control valves 16a to 16e provided in the hydraulic control device of the present embodiment are described. It has the same configuration.

The cylinder 30 is a cylindrical cylinder, one end of which is closed and the other end of which is open. Further, three ports 30a, 30b and 30c are provided on the outer peripheral surface of the cylinder 30. The first port 30a is connected to the flow rate control valve 18, and the hydraulic oil flowing out from the flow rate control valve 18 flows into the cylinder 30 through the first port 30a. Further, the second port 30b is connected to the corresponding friction fastening element 22. Therefore, the second port 30b of the cylinder 30 of the fifth fastening hydraulic control valve 16e (FIG. 4) is connected to the hydraulic chamber F5 (FIG. 2) of the second brake BR2 of the automatic transmission 20. Further, the third port 30c is configured to allow the hydraulic oil in the cylinder 30 to flow out, and the hydraulic oil that has flowed out from the third port 30c is collected in the oil pan 28.

The solenoid valve 34 is configured to slide the spool 32 in the cylinder 30 by passing a predetermined control current through the built-in coil 34a. That is, when a predetermined control current is applied to the coil 34a of the solenoid valve 34, the spool 32 is moved to the position shown in FIG. 5, and the fastening hydraulic control valve 16 supplies the hydraulic pressure to the friction fastening element 22. It becomes a state. On the other hand, when the coil 34a of the solenoid valve 34 is not energized, the spool 32 is moved to the position shown in FIG. It will be in a non-supply state. That is, in the solenoid valve 34, when a predetermined control current is supplied, the friction fastening element 22 provided correspondingly is switched to the fastening state, and when the control current is not supplied, the friction fastening element 22 is not fastened. It is a normally closed solenoid configured to switch to the state. Further, in the present embodiment, the solenoid valve 34 basically uses an ON / OFF solenoid used to move the spool 32 to two positions, the position shown in FIG. 5 and the position shown in FIG. be able to.

The spool 32 is a stepped cylindrical component slidably arranged in the cylinder 30, and is configured to open and close each port of the cylinder 30. Further, an urging spring 36 is arranged between the tip of the spool 32 and the end of the cylinder 30 on the closed side. The urging spring 36 is a coil spring arranged in the cylinder 30, and urges the spool 32 toward the open end of the cylinder 30. Therefore, when the coil 34a of the solenoid valve 34 is energized, the spool 32 is driven by the solenoid valve 34 to the position shown in FIG. 5 against the urging force of the urging spring 36. On the other hand, when the energization of the solenoid valve 34 to the coil 34a is stopped, the spool 32 is moved to the position shown in FIG. 6 by the urging force of the urging spring 36.

Further, the spool 32 is formed with a first large diameter portion 32a, a small diameter portion 32b, and a second large diameter portion 32c in this order from the tip, and each large diameter portion has a diameter substantially the same as the inner diameter of the cylinder 30. It is configured. Therefore, the sliding of the spool 32 changes the connection state of each port of the cylinder 30. That is, in the energized state of the solenoid valve 34 shown in FIG. 5, the first port 30a and the second port 30b are aligned with the small diameter portion 32b of the spool 32, so that the first port 30a and the second port 30b are in contact with each other. Communicate. As a result, the hydraulic oil supplied from the flow control valve 18 is supplied to the friction fastening element 22 provided correspondingly, and the friction fastening element 22 is switched to the fastening state. On the other hand, the third port 30c is blocked by the second large diameter portion 32c.

On the other hand, in the non-energized state of the solenoid valve 34 shown in FIG. 6, the second port 30b and the third port 30c are aligned with the small diameter portion 32b of the spool 32, so that the second port 30b and the third port 30c Is communicated. As a result, the hydraulic oil in the friction fastening element 22 flows out to the oil pan 28 via the cylinder 30 of the fastening hydraulic control valve 16. On the other hand, the hydraulic oil that has flowed into the cylinder 30 from the flow control valve 18 through the first port 30a is stopped by the first large diameter portion 32a of the spool 32 and stays in the cylinder 30.

In this way, the fastening / non-fastening of each friction fastening element 22 is realized by operating the correspondingly provided fastening hydraulic control valve 16 and switching the supply / non-supply of hydraulic pressure to each friction fastening element 22. Will be done. The control device 12a built in the ECU 12 is a friction fastening element provided corresponding to the fastening hydraulic control valve 16 by energizing the solenoid valve 34 of each fastening hydraulic control valve 16 with a predetermined control current. 22 is switched between fastening and non-fastening.

However, when the solenoid valve 34 of the fastening hydraulic control valve 16 is not energized with the control current for a long period of time, such as when the vehicle is parked or stopped, the spool 32 of the fastening hydraulic control valve 16 may be used. It may stick to the position shown in FIG. 6 in the cylinder 30. In this way, when the spool 32 is stuck, even if the control current is applied to the solenoid valve 34 by the control device 12a, the fastening hydraulic control valve 16 is not immediately switched, and the fastening hydraulic control valve 16 is not immediately switched. There will be a delay in switching. In particular, if the switching of the fifth fastening hydraulic control valve 16e corresponding to the fifth friction fastening element 22e to be fastened at the time of starting is delayed, the starting responsiveness of the vehicle is lowered.

FIG. 7 is a graph showing an example of the behavior of the fastening hydraulic control valve 16 when sticking occurs. The horizontal axis represents time, and the vertical axis corresponds to the fastening hydraulic control valve 16. The hydraulic pressure supplied to the friction fastening element 22 is shown. In FIG. 7, the solid line shows the change in the oil pressure in the normal fastening hydraulic control valve 16 in which the sticking has not occurred, and the broken line shows the change in the oil pressure in the fastening hydraulic control valve 16 in which the sticking has occurred. There is.

As shown by the solid line in FIG. 7, in the fastening hydraulic control valve 16 in which sticking does not occur, when the energization of the coil 34a of the solenoid valve 34 is started at _{time t 0, the time is about 0.7 seconds later.} The oil pressure starts to rise at _{t 1.} Then, after once pressure reaches a constant value, and a curve that again rapidly increases at time t _2. On the other hand, the broken line in FIG. 7 shows that the coil 34a of the fastening hydraulic control valve 16 is not energized for about 1 hour, and the coil 34a is energized with the spool 32 of the fastening hydraulic control valve 16 intentionally fixed. It shows the change of the oil pressure when it is done.

As shown by the broken line in FIG. 7, in the fastening hydraulic control valve 16 in which the sticking occurred, the oil pressure did not rise for a while after the energization of the coil 34a of the solenoid valve 34 was started at _{time t 0, and the time.} after the start of the energization in t _0, at time t ₃ when passed about 2.9 seconds, the hydraulic pressure is beginning to rise. The behavior of the fastening hydraulic control valve 16 illustrated in FIG. 7 is not based on the actual operating conditions of the automatic transmission 20, but when the coil 34a is not energized for a long time and the spool 32 is stuck, friction occurs. It was confirmed that the supply of oil pressure to the fastening element 22 was delayed. In this way, when the fastening hydraulic control valve 16 is stuck, the increase in the hydraulic pressure of the friction fastening element 22 provided correspondingly is delayed, and the responsiveness of the automatic transmission 20 is lowered.

Therefore, in the hydraulic control device of the present embodiment, the control device 12a of the ECU 12 supplies the anti-sticking current to the solenoid valve 34 provided corresponding to the friction fastening element 22 to be fastened at the time of starting. That is, in the present embodiment, as shown in FIG. 4, the first fastening hydraulic control valve 16a is provided corresponding to the first friction fastening element 22a, and corresponds to the second friction fastening element 22b. A second fastening hydraulic control valve 16b is provided, a third fastening hydraulic control valve 16c is provided corresponding to the third friction fastening element 22c, and a fourth friction fastening element 22d is provided. The fastening hydraulic control valve 16d is provided, and the fifth fastening hydraulic control valve 16e is provided corresponding to the fifth friction fastening element 22e. The control device 12a is a coil of the solenoid valve 34 of the fifth fastening hydraulic control valve 16e provided corresponding to one of the friction fastening elements to be fastened at the time of starting among these fastening hydraulic control valves. The 34a is configured to supply an anti-sticking current.

FIG. 8 is a diagram showing an example of a sticking prevention current waveform supplied to the coil 34a of the solenoid valve 34 of the fifth fastening hydraulic control valve 16e.
As shown in FIG. 8, the anti-sticking current is supplied in the form of one pulse. In the present embodiment, after the engine of the vehicle is started and before the vehicle is started, the anti-sticking current is energized in a pulsed manner for a period of about 10 [mSec]. Further, in the present embodiment, the current supplied during the energization period of about 10 [mSec] is set to be smaller than the control current of the fastening hydraulic control valve 16. In this way, by supplying the anti-sticking current to the coil 34a of the fifth fastening hydraulic control valve 16e, the spool 32 at the position shown in FIG. 6 is slightly moved toward the position shown in FIG. It returns to the original position.

Next, with reference to FIG. 9, the relationship between the current supplied to the coil 34a of the fastening hydraulic control valve 16 and the hydraulic pressure supplied to the friction fastening element 22 provided corresponding thereto will be described. As described above, when the "control current" is supplied to the coil 34a of the solenoid valve 34 of the fastening hydraulic control valve 16, the spool 32 is moved to the state shown in FIG. In this state, since the first port 30a and the second port 30b of the cylinder 30 are completely opened, the oil pressure from the flow control valve 18 is sufficiently supplied to the corresponding friction fastening element 22. The friction fastening element 22 is brought into the fastening state. As shown in FIG. 9, in the present embodiment, the control current for the fastening hydraulic control valve 16 is about 1 [A].

On the other hand, in the present embodiment, the "sticking prevention current" supplied to the coil 34a of the fifth fastening hydraulic control valve 16e is supplied in a pulse shape as shown in FIG. This "sticking prevention current" is set to about 0.5 [A], which is less than the "control current". In this way, by supplying the pulse-shaped "sticking prevention current" to the coil 34a of the solenoid valve 34 of the fastening hydraulic control valve 16, the spool 32 of the fastening hydraulic control valve 16 is changed from the state shown in FIG. It starts to move toward the position shown in FIG. However, since the energization period of the "sticking prevention current" is very short, high oil pressure is not generated in the fifth friction fastening element 22e provided corresponding to the fifth fastening hydraulic control valve 16e. However, at the moment when the anti-sticking current flows through the coil 34a, the spool 32 moves, so that a thin oil film is formed between the cylinder 30 and the spool 32, and the occurrence of sticking of the spool 32 is suppressed.

In the present embodiment, the current supplied in a pulse shape as the "sticking prevention current" is set to about 0.5 [A], which is smaller than the "control current", but as a modification, "sticking" is used. It is also possible to set the "prevention current" to a current value similar to the "control current".

Next, the operation of the hydraulic control device according to the embodiment of the present invention will be described with reference to FIG.
FIG. 10 is a flowchart showing a process executed by the control device 12a of the ECU 12 in the hydraulic control device according to the embodiment of the present invention. The process according to the flowchart shown in FIG. 10 is executed when the power of the parked / stopped vehicle equipped with the automatic transmission 20 is turned on. Further, the flowchart of FIG. 10 shows a process for setting a current to be supplied to the coil 34a of the solenoid valve 34 such as the fifth fastening hydraulic control valve 16e, which is a “zero touch clutch”.

First, in step S1 of FIG. 10, it is determined whether or not the engine (not shown) of the vehicle equipped with the automatic transmission 20 has been started. If the driver has started the engine (not shown), the process proceeds to step S2, and if the starting operation has not been performed, the process in step S1 is repeated. When the engine (not shown) is started, the hydraulic pump 26 is operated and the oil pressure is supplied to the hydraulic control circuit 14.

Next, in step S2, it is determined whether or not the plurality of friction fastening elements 22 are fastened. Whether or not each friction fastening element 22 is fastened is determined based on a detection signal of the fastening hydraulic sensor 10 (FIG. 4) provided corresponding to each friction fastening element 22. When the pressure detected by the fastening hydraulic sensor 10 is equal to or higher than a predetermined pressure, it is determined that the friction fastening element 22 provided corresponding to the fastening hydraulic sensor 10 is fastened. If it is determined that the plurality of friction fastening elements 22 are fastened, the process proceeds to step S12, and if the number of the friction fastening elements 22 fastened is 0 or 1, the process proceeds to step S3.

In step S3, the supply of the sticking prevention current to the solenoid valve 34 of the fifth fastening hydraulic control valve 16e corresponding to the second brake BR2, which is the fifth friction fastening element 22e, is started. Here, as described above, since the second brake BR2 is a zero-touch clutch, there is a possibility that the second brake BR2 will be engaged even if the anti-sticking current is supplied for a short period of time. In such a case, for example, assuming that the first fastening hydraulic control valve 16a (first clutch C1) and the fourth fastening hydraulic control valve 16d (first brake BR1) are engaged, the second brake BR2 There is a risk that the vehicle will start unexpectedly due to the conclusion of the brake system.

However, since it is confirmed in step S2 that the number of the friction fastening elements 22 to be fastened is 0 or 1, it is possible to reliably avoid the unexpected start of the vehicle. That is, as shown in FIG. 3, in the present embodiment, since the automatic transmission 20 is configured to transmit power when the three friction fastening elements 22 are fastened at the same time, 0 or one friction Even if the second brake BR2 is fastened while the fastening element 22 is fastened, the power is not transmitted. As a modified example, the present invention can be configured so that the anti-sticking current is supplied only when there is no friction fastening element in the fastened state, or power is transmitted by an automatic transmission based on other conditions. Can also be confirmed that does not occur.

Next, in step S4, it is determined whether or not a predetermined time has elapsed after the supply of the anti-sticking current was started in step S3. As described above, in the present embodiment, the period for supplying the anti-sticking current is about 10 mSec (FIG. 8).
If a predetermined time has not elapsed after the start of supply of the anti-sticking current, the process proceeds to step S6, where it is determined whether or not the shifter (not shown) provided in the vehicle has been switched to the drive range. Will be done. If the drive range has not been switched in step S6, the process returns to step S4, and thereafter, the processes of steps S4 → S6 → S4 are repeated until a predetermined time elapses.

When a predetermined time elapses after the start of supply of the anti-sticking current, the process proceeds to step S5, where the supply of the anti-sticking current to the solenoid valve 34 of the fifth fastening hydraulic control valve 16e is stopped. As a result, the supply of the anti-sticking current of about 10 mSec for a predetermined time is completed, and the process proceeds to step S8. By supplying this anti-sticking current, the spool 32 of the fifth fastening hydraulic control valve 16e is driven from the state shown in FIG. 6 to the left in the figure, and then returns to the state shown in FIG. As a result, even if the spool 32 is stuck to the cylinder 30, this is eliminated.

On the other hand, if the driver switches the shifter (not shown) of the vehicle to the drive range after the supply of the anti-sticking current is started in step S3 and before the predetermined time elapses, the process in the flowchart is the step. The process proceeds from S6 to step S7. In step S7, the supply of the anti-sticking current to the solenoid valve 34 of the fifth fastening hydraulic control valve 16e is stopped halfway before the lapse of a predetermined time. That is, when the shifter (not shown) is switched to the drive range while the anti-sticking current is being supplied, the friction fastening elements (first clutch C1 and first brake BR1) that are fastened at the time of starting other than the second brake BR2). Is concluded and the vehicle may start. Therefore, when the shifter (not shown) is switched to the drive range while the anti-sticking current is being supplied, the supply of the anti-sticking current is stopped (step S7), and the process proceeds to step S8.

In the present embodiment, the supply of the anti-sticking current is extremely short (about 10 mSec), and it is extremely unlikely that the shifter (not shown) is switched to the drive range during this period. In the present embodiment, the processing of steps S6 and S7 is provided to deal with such an extremely low risk. Further, by providing the processes of steps S6 and S7, it is possible to set a relatively long period for supplying the anti-sticking current.

On the other hand, if it is determined in step S2 that the plurality of friction fastening elements 22 are fastened, the process proceeds to step S8. That is, when a plurality of friction fastening elements 22 are fastened after the engine (not shown) is started, the fifth friction fastening element 22e (second brake BR2) is fastened by supplying the anti-sticking current. If this happens, the vehicle may start unexpectedly, so that the anti-sticking current is not supplied. When the vehicle is parked or stopped, the automatic transmission 20 is usually set to neutral, and all friction fastening elements 22 are not fastened. However, even if any of the friction fastening elements 22 is fastened due to a malfunction or the like, the state of the friction fastening element 22 is checked in step S2 so that the vehicle is not suddenly transmitted.

Next, in step S8, it is determined whether or not the driver has switched the shifter (not shown) of the vehicle to the drive range, and if not, the process of step S8 is repeated. That is, after the supply of the anti-sticking current is completed in step S5, or after it is determined that the plurality of friction fastening elements 22 are fastened in step S2, the driver sets the shifter (not shown) in the drive range. Wait until the switch is made, and then proceed to step S9. If it is determined in step S6 that the shifter (not shown) has already been switched to the drive range, the process proceeds to step S9 without waiting.

In step S9, the control device 12a supplies a control current to the solenoid valve 34 of the first fastening hydraulic control valve 16a and the fourth fastening hydraulic control valve 16d, and the first fastening hydraulic control valve 16a is provided corresponding to the control current. The friction fastening element 22a (first clutch C1) and the fourth friction fastening element 22d (first brake BR1) are fastened. As a result, among the friction fastening elements 22 to be fastened when the vehicle starts, the friction fastening elements 22 other than the fifth friction fastening element 22e, which is a zero-touch clutch, are fastened.

Next, in step S10, it is determined whether or not a start command has been input to the ECU 12, and if no start command has been input, the process of step S10 is repeated. In the present embodiment, when the amount of depression of the accelerator pedal (not shown) detected by the throttle opening sensor 4 is equal to or greater than a predetermined threshold value and the brakes (foot brake and side brake) are turned off. , It is determined that the start command has been input to the ECU 12.

When the start command is input, the process proceeds to step S11. In step S11, the control device 12a supplies a control current to the solenoid valve 34 of the fifth fastening hydraulic control valve 16e, and the control device 12a is provided correspondingly. The friction fastening element 22e (second brake BR2) of 5 is fastened. In this way, by fastening the fifth friction fastening element 22e when the vehicle starts, the automatic transmission 20 transmits the power of the engine (not shown), and the vehicle is started. Here, since the fifth friction fastening element 22e (second brake BR2) is composed of the zero touch clutch, when the control current is supplied, the fifth friction fastening element 22e (second brake BR2) is brought into the fastening state in an extremely short time. Therefore, the vehicle is started in response to the start operation by the driver.

Next, in step S12, the normal shift control of the automatic transmission 20 is started, and the processing of the flowchart shown in FIG. 10 is completed. In normal shift control, the control device 12a sets an appropriate shift stage based on detection signals of the vehicle speed sensor 2, the throttle opening sensor 4, the turbine rotation speed sensor 6, and the like. Then, the control device 12a sends a control signal to each fastening hydraulic control valve 16 so that the shift stage is realized, and selectively fastens the first to fifth friction fastening elements 22a to 22e.

According to the hydraulic control device of the embodiment of the present invention, the control device 12a is a fifth friction fastening element 22e of the friction fastening elements 22 which is fastened at the time of starting after the engine of the vehicle is started and before the start. A sticking prevention current is supplied to the solenoid valve 34 of the fifth fastening hydraulic control valve 16e provided in response to the above (step S3 in FIG. 10). As a result, the occurrence of sticking of the spool 32 of the fifth fastening hydraulic control valve 16e is suppressed. That is, by supplying the anti-sticking current to the solenoid valve 34, the sticking of the spool 32, which is a component driven by the solenoid valve 34, is eliminated, and when the driver performs the starting operation, the vehicle can be started smoothly. Can be done. Since the hydraulic pump 26 is operating after the engine of the vehicle is started, when the anti-sticking current is supplied to the solenoid valve 34, the fifth friction fastening element 22e provided corresponding to the solenoid valve 34 is fastened. However, since the anti-sticking current is supplied before the vehicle starts, the vehicle is not started by fastening the fifth friction fastening element 22e.

Further, according to the hydraulic control device of the present embodiment, the anti-sticking current supplied after the engine is started and before the vehicle starts is set to a current lower than the control current (FIG. 8). It is possible to suppress the consumption of electric power due to the supply, and it is possible to suppress the occurrence of sticking with low power consumption.

Further, according to the hydraulic control device of the present embodiment, when the control current is supplied to the solenoid valve 34, the hydraulic pressure is supplied to the friction fastening element 22 provided correspondingly (FIG. 9), and the solenoid valve 34 is brought into the fastening state. Therefore, the non-fastened state can be achieved without passing a current through the solenoid valve 34, and the current consumption can be reduced. Further, since the anti-sticking current supplied after the engine is started and before the vehicle starts is only required to pass a minute current, the amount of current consumed to suppress the sticking can be further reduced.

Further, according to the hydraulic control device of the present embodiment, the anti-sticking current is supplied only to the solenoid valve 34 provided corresponding to the fifth friction engaging element 22e, which is a zero-touch clutch, before the vehicle starts. (Step S3 in FIG. 10), it is possible to reliably prevent the vehicle from being started by supplying the anti-sticking current.

Further, according to the hydraulic control device of the present embodiment, after stopping the supply of the anti-sticking current to the fifth friction engaging element 22e which is a zero touch clutch (step S5 in FIG. 10), the clutch is engaged at the time of starting. The friction engaging elements other than the zero touch clutch are engaged (step S9 in FIG. 10). Therefore, when starting the vehicle, the vehicle can be started only by supplying a control current to the solenoid valve 34 provided corresponding to the zero touch clutch (step S11 in FIG. 10), and the vehicle start response. The sex can be made extremely good.

Although the embodiments of the present invention have been described above, various modifications can be made to the above-described embodiments. In particular, in the above-described embodiment, the present invention has been applied to an automatic transmission provided with six clutches including a zero-touch clutch and two brakes, but the present invention is applied to an automatic transmission of any type. be able to.

Further, in the above-described embodiment, as the solenoid valve 34 provided in the fastening hydraulic control valve 16, a normally closed solenoid is adopted in which hydraulic pressure is supplied by supplying a control current to fasten the friction fastening element 22. Was there. On the other hand, as a modified example, it is also possible to adopt a normally open solenoid in which hydraulic pressure is supplied by stopping the control current and the friction fastening element 22 is fastened. In this case, when the hydraulic pressure is supplied to the friction fastening element 22, the control current to the solenoid valve is stopped (current = 0), and when the supply of hydraulic pressure to the friction fastening element 22 is stopped, the solenoid valve is predetermined. Control current is supplied. Further, the anti-sticking current is supplied intermittently. It is also possible to mix a normally closed solenoid and a normally open solenoid in the flood control circuit.

1 Automatic transmission system 2 Vehicle speed sensor 4 Throttle opening sensor 6 Turbine rotation speed sensor 8 ATF hot water temperature sensor 10 Flood control sensor for fastening 12 ECU
12a Control device 14 Hydraulic control circuit 16 Fastening hydraulic control valve 18 Flow control valve 20 Automatic transmission 20a Transmission case 20b Input shaft 20c Output shaft 22 Friction fastening element 24a Power transmission member 24b Power transmission member 24c Power transmission member 24d Power transmission Member 24e Power transmission member 24f Power transmission member 24g Power transmission member 24h Power transmission member 26 Hydraulic pump 28 Oil pan 30 Cylinder 30a First port 30b Second port 30c Third port 32 Spool 32a First large diameter part 32b Small diameter Part 32c Second large diameter part 34 Electromagnetic valve 34a Coil 36 Bias spring

Claims (5)

A hydraulic control device for an automatic transmission that shifts gears by switching between fastening and non-fastening of a plurality of friction fastening elements.
Solenoid valves that are provided for each of the friction fastening elements and that switch between fastening and non-fastening of the friction fastening elements by switching the supply / non-supply of hydraulic pressure to the friction fastening elements.
A control device that switches the supply / non-supply of hydraulic pressure to each of the friction fastening elements by supplying a predetermined control current to these solenoid valves.
Have,
The control device is provided corresponding to the friction fastening element to be fastened at the time of starting the vehicle among the above friction fastening elements after the engine of the vehicle equipped with the automatic transmission is started and before the vehicle starts. A flood control device characterized in that it is configured to supply a sticking prevention current to the above-mentioned solenoid valve. The hydraulic control device according to claim 1, wherein the anti-sticking current supplied after the engine of the vehicle is started and before the vehicle starts is set to a current lower than the control current. The hydraulic pressure according to claim 1 or 2, wherein at least one of the above solenoid valves is configured so that when the control current is supplied, the corresponding friction fastening element is switched to the fastening state. Control device. At least one of the plurality of friction fastening elements is a zero-touch clutch in which the clearance between the friction plates constituting the friction fastening element is substantially zero, and when the vehicle equipped with the automatic transmission is started. In, a plurality of friction engaging elements including the zero-touch clutch are fastened, and the control device is configured to supply the anti-sticking current only to the solenoid valve provided corresponding to the zero-touch clutch. The hydraulic control device according to any one of claims 1 to 3. After stopping the supply of the anti-sticking current to the zero-touch clutch, the control device engages friction engaging elements other than the zero-touch clutch that are engaged when the vehicle equipped with the automatic transmission starts. The hydraulic control device according to claim 4.

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