JPH0158787B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a clutch operation hydraulic control device for a transmission, and more specifically, by switching and connecting a predetermined clutch using hydraulic pressure, forward and backward movement and The present invention relates to a clutch operation hydraulic control device for a transmission that performs speed gear switching. This is, for example,
It is used in the field of hydraulic control of transmission devices such as construction and civil engineering vehicles.

[Conventional technology]

Figure 1 shows how, by engaging and disengaging the plate clutch through hydraulic pressure, the gear combination can be selected and the speed gear can be switched in any state of forward or backward travel, or the speed gear can be switched between forward or reverse at any speed. This is an example of a conventional clutch operation hydraulic control device. In this system, hydraulic pressure from a pump is applied to a spool, and the discharge hydraulic pressure is controlled to change gears and to switch between forward and backward clutches.

Briefly, hydraulic oil from the pump 1 is introduced into a hydraulic chamber 3 of a hydraulic control valve 2. The hydraulic oil is supplied to the spool chamber 5 through the introduction path 4, moves the spool 6 in the direction of the arrow 7, and is led out to the torque converter 9 through the conduit 8.

Introduced into the back pressure chamber 15 of the hydraulic control valve 2 through the throttle 11 interposed in the discharge pipe 10 connected to the hydraulic chamber 3 and the throttle 14 of the pressure regulating valve 13 connected to the pipe 12. The hydraulic oil moves the hydraulic control piston 16 against the spring 17 in the opposite direction of the arrow 7 to the stopper 18 position. As a result, the pressure in the hydraulic chamber 3 is a pressure P1 that balances the elastic force of the spring 17.
will be maintained.

In this state, if the gear clutch switching valve 19 is set to 2nd gear (2ND) as shown in the figure,
From the hydraulic chamber 3 to the discharge pipe line 10, the branch point 20, and the pipe line 2
The hydraulic oil supplied through the piston 19
It is supplied to the second gear clutch 22B via a chamber 19A partitioned by portions a and 19b.

On the other hand, the remaining hydraulic oil separated at the above-mentioned branch point 20 is separated at a branch point 24 of the pipe line 12 and is supplied to the forward/reverse clutch switching valve 25. However, when the forward/reverse clutch switching valve 25 is in the neutral state as shown, the chamber 25A is closed to the pistons 25a, 25b.
Since the hydraulic fluid is sealed in the forward clutch 2,
6A and reverse clutch 26B are not supplied. Therefore, in order to drive forward, when the spool 25S of the forward/reverse clutch switching valve 25 is moved in the direction of arrow 27 from the neutral position N to the forward travel position F by an operation lever (not shown), the forward clutch 2
6A and a branch point 24 communicate with each other, and the hydraulic oil supplied from the pump 1 is transferred to the forward clutch 26A through the branch points 20, 24 and the forward/reverse clutch switching valve 25.
supplied to

At this time, since the hydraulic oil flows through the throttle 11, a pressure difference occurs before and after the throttle 11, and the branch point 2
The operating pressure P1 of 0 drops to a pressure P2, which is the initial charging pressure to the forward clutch 26A, as will be described later, as shown from line 20a to line 20b in FIG. 2a. Along with this, the pressure of the hydraulic oil introduced into the pressure regulating valve 13 also decreases, and the piston 28 of the pressure regulating valve 13 resists the spring 29 due to the elastic force of the spring 17 and the hydraulic pressure in the back pressure chamber 15. and is moved in the direction of arrow 30, and the pipe line 31 and the drain tank 32 are brought into communication. The hydraulic oil in the back pressure chamber 15 of the hydraulic control valve 2 is
As the hydraulic control piston 16 moves in the direction of arrow 7, the water is returned to the drain tank 32. The elastic force of the spring 17 becomes smaller, and in order to balance this, the pressure P1 in the hydraulic chamber 3 drops to a pressure P3 higher than the above-mentioned pressure P2, as shown from line 3a to line 3b shown in FIG. 2a. do. At this time, back pressure chamber 1
5 also drops from the state of line 15a to pressure P2 as shown by line 15b.

On the other hand, the pressure within forward clutch 26A is
During the time Ta during which the pressure immediately rises from the atmospheric pressure at point a to P2 as shown by line 26b, filling of hydraulic oil is started, and the clutch piston (not shown) contacts the clutch plate at that pressure.
Filling continues as per line 26c. During the time Ta until the clutch piston makes a full stroke, an amount of hydraulic oil Qa corresponding to the shaded area in FIG. 2b is filled.

In this way, when the clutch piston makes a full stroke, the pressures before and after the restriction 11 in the discharge line 10 are balanced. The oil pressure in the back pressure chamber 15 is the pressure P
2 to pressure P1 following line 15d, and moves hydraulic control piston 16 in the direction opposite to arrow 7, the pressure in hydraulic chamber 3 increases from pressure P3. This pressure gradually increases as shown by line 3d because the amount of oil entering the back pressure chamber 15 is restricted by the throttle 14 and the hydraulic control piston 16 moves gradually, and becomes constant when the pressure reaches P1. Become. Due to this oil pressure increase, the pressing force of the clutch gradually increases, and the forward clutch 26A is connected without a shock as shown by the line 26d.

The case where the forward/reverse clutch switching valve 25 is switched to the forward traveling position F has been described above. Of course, the same operation occurs when switching from the neutral position to the reverse travel position R. Further, when the spool 19S of the speed clutch switching valve 19 is moved in the direction of arrow 33 in order to switch from 2nd speed to 3rd speed (3RD), the pipe line 34 and the pipe line 35 are connected, and the 3rd speed gear Clutch 22C can be supplied with hydraulic oil. And the second speed gear clutch 22B
The hydraulic oil that had been supplied to the tank 36 is returned to the tank 36, and the subsequent operation is the same as described above.

[Problem to be solved by the invention]

According to such a clutch operation hydraulic control device, the spool and piston are mechanically moved by hydraulic pressure to switch to a predetermined clutch, so the period from the start of the switching operation until the completion of filling the clutch with hydraulic oil is The hydraulic pressure decreases and the time required for switching connections increases. Therefore, this results in a time delay when starting the vehicle and a decrease in vehicle speed when changing gears.
A problem arises in that the driving sensation is unfavorable.

By the way, Japanese Patent Application Laid-Open No. 55-33911 discloses a system in which the hydraulic pressure supplied to a hydraulic servo device can be adjusted accurately by electronic control to prevent shocks when changing gears in an automatic transmission. The equipment is described.

The present invention has been made in order to solve the above-mentioned problems, and its purpose is to provide a transmission that can shorten the time required for predetermined clutch switching and improve the driving sensation when starting a vehicle or changing gears. An object of the present invention is to provide a clutch operation hydraulic control device.

[Means to solve the problem]

The clutch operation hydraulic control device for a transmission of the present invention engages and disengages a plate clutch through hydraulic pressure, thereby selecting a combination of gears and switching speed gears in any state of forward or backward movement. The present invention is applied to a hydraulic control system for a transmission that switches between forward and backward speeds.

Its features will be explained based on the example shown in FIG.
A hydraulic control valve 2 is provided which includes a hydraulic control piston 16 having a function of gradually increasing the hydraulic pressure when C, 26A, and 26B are coupled, and a back pressure chamber 15 for generating starting pressure for the hydraulic control piston 16. It will be done. Then, the hydraulic control valve 2 and the forward/reverse clutch 26
A, 26B are interposed in conduits 43, 44,
Forward and backward clutch switching valves 42A and 42B that control the supply and discharge of hydraulic oil to the forward and backward clutches 26A and 26B.
, hydraulic control valve 2 and forward/reverse clutches 26A, 26
Hydraulic oil is supplied to the speed clutches 22A to 22C through pipes 46 to 48 branched at the outlet of the hydraulic control valve 2 between the pipes 43 and 44 to the speed clutches 22A to 22C. It is provided in the conduit 52 between the speed clutch switching valves 45A to 45C that control supply and discharge, and the back pressure chamber 15 of the hydraulic control valve 2 and the drain tank 32, and discharges and switches the hydraulic oil in the back pressure chamber 15. A discharge switching solenoid valve 51 is installed. In addition, in response to the opening/closing control signal for the speed gear clutch switching valves 45A to 45C or the forward/reverse clutch switching valves 42A, 42B, the respective clutch switching valves 42
Solenoid excitation signals for the respective opening/closing timings Tij, Tik are set so as to have a time difference with respect to the opening/closing signals of A, 42B, 45A to 45C.
A control unit 53 is provided which outputs output to the discharge switching solenoid valve 51, and by switching the discharge switching solenoid valve 51 during forward/forward switching and gear shifting, each clutch 22A to 22C, 16A, 26B is controlled.
By adjusting the hydraulic pressure supplied to the engine, it is possible to shorten the switching time for forward/reverse switching and gear shifting while alleviating shock.

[Effect]

When the operating lever 54 is tilted in any direction, for example, into the forward travel position F, the selection signal is input to the control unit 53. The command passes through the control unit 53, and an opening signal for the forward clutch switching valve 42A is output, thereby opening the forward clutch switching valve 42A.

The forward clutch switching valve 42A switches instantaneously, and the forward clutch 26A begins to be filled with hydraulic oil at a pressure P4 (see FIG. 5a), and the pressure at the branch point 20 drops. Since no command is issued to the discharge switching solenoid valve 51, it remains in the closed position and the back pressure chamber 15 is not connected to the drain tank 32. Due to the pressure drop at the branch point 20, the pressure oil in the back pressure chamber 15 is supplied to the branch point 20 through the throttle 49. Therefore, the amount of oil to be filled into the forward clutch 26A is increased, and the filling time is shortened.

In the control unit 53, the opening delay time T41 and the opening time T42 have already been selected, and after this opening delay time T41 has been counted, the control unit 53 outputs an opening signal for the discharge switching solenoid valve 51, and then Valve 51 is switched to the discharge position and remains open for a time T42. As a result, the drain tank 32 and the back pressure chamber 15 are brought into communication, and the pressure P1 in the back pressure chamber 15 drops to atmospheric pressure.

Since the hydraulic control piston 16 is moved by the hydraulic pressure of the hydraulic chamber 3, the hydraulic pressure of the hydraulic chamber 3 drops to pressure P2. Accordingly, after the pressure in the forward clutch 26A drops from the state P4 to the pressure P2, that pressure is maintained. At this time, the clutch piston in the forward clutch 26A comes into contact with the clutch plate, and the filling of the hydraulic oil into the clutch is completed. Since the contact pressure in the clutch is low, there is no shock during engagement.

The time required for filling the hydraulic oil during this period is shorter than in the conventional example. Then, when time T42 has elapsed, a command is output from the control unit 53 to switch the discharge switching solenoid valve 51 to the closed position.
The valve is closed and the hydraulic fluid in the hydraulic chamber 3 is gradually introduced into the back pressure chamber 15 via the throttle 49. Therefore, the piston 16 moves in the opposite direction and the pressure P1
The pressure in the hydraulic chamber 3 increases until . Along with this, the pressure within the forward clutch 26A also rises to a predetermined pressure P1, and the connection of the forward clutch 26A is completed.

〔Effect of the invention〕

According to the present invention, instead of filling the clutch with low-pressure hydraulic oil by mechanical operation and connecting the clutch, the control signal from the control unit is used to set a time difference with respect to the opening/closing signal of each clutch switching valve. , the connection is made by filling the desired clutch with high pressure hydraulic oil. Therefore, the time required to engage the clutch is not redundant, a reduction in vehicle speed during gear shifting can be avoided, and the driving sensation is appropriate.
Furthermore, since the clutch switching time can be arbitrarily set in the control unit, it is possible to adjust in advance the cushioning of the impact when switching the clutch and the time delay when starting the vehicle for each vehicle type.

〔Example〕

Hereinafter, the present invention will be explained in detail based on examples thereof.

Figure 3 shows how, by engaging and disengaging the plate clutch through hydraulic pressure, you can select a combination of gears and change speed gears in any state of forward or backward travel, or switch between forward or reverse at any speed. FIG. 2 is a configuration diagram of a hydraulic control device for a transmission configured to perform the following. 2 in the diagram
is a hydraulic control valve in which a spool 6 and a hydraulic control piston 16 are mounted so that a spring 17 is sandwiched therebetween. The hydraulic control piston 16 is connected to the speed clutches 22A to 22C and the forward/reverse clutch 26.
It has a function of controlling the pressure of hydraulic oil supplied to clutches A and 26B and gradually increasing the hydraulic pressure when each clutch 22A to 22C, 26A, and 26B is engaged.

The spool 6 is provided with an introduction path 4 through which the hydraulic oil introduced by the pump 1 flows into the spool chamber 5, and the spool 6 is configured to be reciprocally displaced from the spool 6 hydraulic control piston 16 by hydraulic pressure. . Further, a pipe line 8 is provided between the hydraulic chamber 3 and the torque converter 9, so that hydraulic oil can be led out to the torque converter 9.

42A and 42B are respective pipe lines 4 between the hydraulic control valve 2 and the forward clutch 26A and reverse clutch 26B.
This is a forward/reverse clutch switching valve provided at 3 and 44. The forward/reverse clutch switching valves 42A, 42B are electromagnetic switching valves, and the forward/reverse clutch switching valves 26A, 2
It controls the supply and discharge of hydraulic oil to 6B. 4
5A to 45C are connected to first to third gear clutches 22A to 22C, which are branched at the outlet of the hydraulic control valve 2 of the pipes 43 and 44 between the hydraulic control valve 2 and the forward/reverse clutches 26A and 26B. This is a speed stage clutch switching valve interposed in the conduits 46 to 48 leading to the speed stage clutch. This is also an electromagnetic switching valve, and the speed gear clutches 22A to 2
It controls the supply and discharge of hydraulic oil to 2C.

49 is the hydraulic control piston 16 of the hydraulic control valve 2
This is a restriction provided in a conduit 50 that connects the back pressure chamber 15 and the hydraulic pressure chamber 3, which are partitioned by. 5
Reference numeral 1 designates a discharge switching solenoid valve interposed in a pipe 52 between the back pressure chamber 15 and the drain tank 32 for generating starting pressure for the hydraulic control piston 16, and for discharging the hydraulic oil in the back pressure chamber 15. I'm starting to switch.

53 receives a signal from the operating lever 54, and also connects each of the above-mentioned switching valves 42A, 42B, 45A to 4.
This is a control unit that outputs opening/closing control signals to the discharge switching solenoid valve 5C and the discharge switching solenoid valve 51. This is performed by receiving the opening/closing control signal of the speed gear clutch switching valves 45A to 45C or the forward/reverse clutch switching valves 42A, 42B.
Solenoid excitation signals for the respective opening/closing timings are sent to the discharge switching solenoid valve 5 so as to have a time difference with respect to the opening/closing signals of B, 45A to 45C.
Output to 1. That is, the opening/closing control intervals Tij and Tik as shown in FIG. 4 are stored in advance, and a solenoid excitation signal is output to each valve based on a command from the operating lever 54. Note that the opening/closing control times Tij and Tik generally differ for each type of vehicle, and the best values previously found through experiments are stored.

According to such an embodiment, it is possible to easily and quickly switch between forward and backward movement and perform a gear change operation as described below.

Hydraulic oil from the pump 1 is introduced into a hydraulic chamber 3 of a hydraulic control valve 2 and is also supplied to a spool chamber 5 via an introduction path 4. Since the spool 6 is moved in the direction of the arrow 7 by the hydraulic pressure acting on the spool chamber 5, the hydraulic chamber 3 and the pipe line 8 are communicated with each other, and the hydraulic oil is led out to the torque converter 9. At this time,
The hydraulic oil introduced into the back pressure chamber 15 through the throttle 49 causes the hydraulic control piston 16 to
It is moved in the opposite direction of the arrow 7 against the spring 17 to the position of the stopper 18, and the pressure in the hydraulic chamber 3 is maintained at a pressure P1 that balances the elastic force of the spring 17.

Now, when the operating lever 54 is in the neutral position of forward and backward movement and the grip 54A is placed in 2nd speed (2ND), neutral and 2nd speed signals are input to the control unit 53. This control unit 53 outputs an opening signal to the speed clutch switching valve 45B, and switches the second speed speed clutch 2.
Hydraulic oil is supplied to 2B. In this state, when the operating lever 54 is tilted, for example, in the direction of the arrow 55 and placed in the forward traveling position F, the selection signal is input to the control unit 53, and the forward clutch switching valve 4
An opening signal that excites the solenoid 42a of 2A, that is, a command to switch from the discharge position E to the supply position S, is output, and the forward clutch switching valve 42A opens.

The forward clutch switching valve 42A switches instantaneously, and the forward clutch 26A has the atmospheric pressure as shown by lines 26e to 26f in FIG. 5a.
As hydraulic oil at pressure P4 begins to be filled, the pressure at branch point 20 drops from line 20e, which is P1, as shown by line 20f. Note that since no command is issued to the discharge switching solenoid valve 51, it remains in the closed position, and the back pressure chamber 15 is closed to the drain tank 32.
Due to the pressure drop at the branch point 20, the pressure oil in the back pressure chamber 15 is supplied to the branch point 20 through the throttle 49. Therefore, the amount of oil to be filled into the forward clutch 26A is increased, and the filling time is shortened.

At this time, the control unit 53 has already set T4 of the opening delay time Tij shown in FIG.
1 and T42 of the opening time Tik are selected, so after this opening delay time T41 is counted, the control unit 53 outputs an opening signal for the discharge switching solenoid valve 51, which is at the closing position N. to the discharge position E, and at time T4
The opening is maintained for 2 hours. As a result, the drain tank 32 and the back pressure chamber 15 will communicate with each other,
The pressure P1 in the back pressure chamber 15 is from line 15e to line 15f.
and descends to atmospheric pressure.

Since the hydraulic control piston 16 moves in the direction of arrow 7 due to the hydraulic pressure of the hydraulic chamber 3 and the elastic force of the spring 17, the elastic force of the spring 17 weakens.
The hydraulic pressure in the hydraulic chamber 3 that balances the elastic force of the spring 17 changes from the pressure P1 on the line 3e to the line 3
f and drops to pressure P2. Accordingly, the pressure in the forward clutch 26A drops from the state of line 26g, which is P4, to pressure P2, as shown by line 26h, and then is maintained as shown by line 26i. At this time, although not shown, the clutch piston in the forward clutch 26A comes into contact with the clutch plate, and the filling of the hydraulic oil into the clutch is completed. Note that the filling time can be controlled by changing the opening delay time Tij, and since the pressure at the time of contact in the clutch is low, there is no shock at the time of connection.

The relationship between the filling amount Qa of hydraulic oil and the time Tb during this period is as shown in Figure 5b, and the required time
Tb is shorter than Ta in the conventional example. Then, when time T42 has elapsed, the control unit 53 moves the discharge switching solenoid valve 51 to the discharge position E.
A command to switch to the closed position N is output from the valve, the valve is closed, and the hydraulic fluid in the hydraulic chamber 3 is gradually introduced into the back pressure chamber 15 via the throttle 49. For this reason,
The piston 16 moves in the opposite direction to the arrow 7, the elastic force of the spring 17 increases, and the pressure in the hydraulic chamber 3 increases along the line 3j to a pressure P1 that balances this elastic force. Along with this, the pressure within the forward clutch 26A also rises to a predetermined pressure P1 along the path 26j, and the connection of the forward clutch 26A is completed.

On the other hand, when the vehicle is running as described above and the vehicle is to be switched to 1st gear, for example, first rotate the operating lever 54 in the direction of arrow 56 to change from 2nd gear to 1st gear.
When the speed is adjusted, the command is input to the control unit 53. Since the previous driving condition has already been input to the control unit 53,
The control unit 53 outputs a signal to switch the operating gear clutch switching valve 45B from the supply position S to the discharge position E, and the valve is closed. The hydraulic oil in the second gear clutch 22B is instantly returned to the tank 57, and the connection is released.

At the same time, a signal for switching from the discharge position E to the supply position S is output to the speed clutch switching valve 45A, which opens the valve and connects the first speed speed clutch 22A. Then, an opening signal with a delay time T11 is output to the discharge switching solenoid valve 51, and after the time T11 has elapsed, it opens, and after the time T12 has elapsed, it closes again, completing the connection of the first speed clutch 26B. The oil pressure change at this time changes in the same way as the oil pressure change along lines 26e to 26j shown in FIG. 5a. Further, when forward movement is changed to reverse movement, the same applies to each of the first, second, and third speeds.

The above is a control device that uses a switching valve to easily and quickly switch the clutch using a signal from the control unit. This is an example in which a clutch switching valve 19 and a forward/reverse clutch switching valve 25 are employed. This system receives an opening/closing control signal for the gear clutch switching valve 19 or the forward/reverse clutch switching valve 25 using an operation lever (not shown), and outputs a switching signal with a time difference with respect to the opening/closing signal of each clutch switching valve. It is configured to output to a switching solenoid valve 51. In addition,
Portions that are the same as those in the above-described example and the conventional example are given the same reference numerals, and their explanation will be omitted.

When the driver puts the forward/reverse clutch switching valve 25 into forward mode, the exhaust switching solenoid valve 51 is opened/closed in the same manner as described above in response to a command from the control unit 53. That is, after time T41 after the forward clutch 26A begins to be filled with hydraulic oil, the discharge switching solenoid valve 51 is switched to the discharge position E, and the pressure is reduced to P3.
It descends from P2 to P2. Thereafter, when time T42 has elapsed, the discharge switching solenoid valve 51 is again controlled to the closed position N, the pressure within the forward clutch 26A increases from P2 to P1, and clutch switching is performed.

As explained in detail in the above two examples, the present invention receives the opening/closing control signal of each clutch switching valve using the electronic control signal from the control unit, and the time difference between the opening/closing signal of each clutch switching valve. Since the clutch is connected by filling the desired clutch with high-pressure hydraulic oil while maintaining the clutch, the time required to connect the clutch is not redundant compared to the case where the clutch is filled with low-pressure hydraulic oil by mechanical operation, and the speed change is made faster. This avoids the reduction in vehicle speed that sometimes occurs, and improves the driving sensation. Since the control unit is provided, the clutch switching time can be set arbitrarily in advance, and can be adjusted depending on the type of vehicle to reduce the impact when switching the clutch and prevent a time delay when starting.

[Brief explanation of drawings]

FIG. 1 is a control system configuration diagram of a conventional clutch operation hydraulic control device for a transmission, and FIG. 2a is a graph showing the relationship between pressure and time in the main parts of the device.
FIG. 2b is a graph showing the relationship between the amount of hydraulic oil filling in the clutch and time, and FIG. 3 is a control system configuration diagram of a clutch operation hydraulic control device which is an embodiment of the present invention.
FIG. 4 is a setting diagram of opening/closing control signals for each switching valve stored in the control unit of the present invention, and FIG. 5a is a graph showing the relationship between pressure and time in the main part of the control device of the present invention. Figure 5b is a graph showing the relationship between the amount of hydraulic oil filling in the clutch and time.
FIG. 6 is a control system configuration diagram of a different embodiment. 2... Hydraulic control valve, 15... Back pressure chamber, 16...
Hydraulic control piston, 19, 45A~45C...Speed stage clutch switching valve, 21, 43, 44, 46~
48... Pipeline, 22A-22C... Speed stage clutch, 25, 42A, 42B... Forward/reverse clutch switching valve, 26A, 26B... Forward/reverse clutch, 32
... Drain tank, 51 ... Discharge switching solenoid valve, 5
3...Control unit, Tij, Tik...Opening/closing control time.

Claims (1)

[Claims] 1. By engaging and disengaging the plate clutch through hydraulic pressure, the gear combination can be selected and the speed gear can be switched in any state of forward or backward movement, or the speed gear can be moved forward or backward in any speed position. In a hydraulic control device for a transmission, the hydraulic control piston has the function of controlling the pressure of hydraulic oil supplied to a speed clutch and a forward/reverse clutch, and gradually increasing the hydraulic pressure when each of the clutches is engaged. and a back pressure chamber for generating starting pressure for the hydraulic control piston, and a hydraulic control valve that is interposed in a conduit between the hydraulic control valve and the longitudinal clutch and connected to the longitudinal clutch. a forward/reverse clutch switching valve for controlling the supply and discharge of hydraulic oil; and a conduit branching at the outlet of the hydraulic control valve of the conduit between the hydraulic control valve and the forward/reverse clutch and leading to the speed gear clutch. a speed gear clutch switching valve that is interposed and controls the supply and discharge of hydraulic oil to the speed gear clutch; and a speed gear clutch switching valve that is provided in a conduit between the back pressure chamber of the hydraulic control valve and the drain tank, and that A discharge switching solenoid valve for switching the discharge of hydraulic oil and an opening/closing control signal for the speed clutch switching valve or the forward/reverse clutch switching valve are received, and a time difference is provided between the opening/closing signals for each of the clutch switching valves. a control unit that outputs a solenoid excitation signal for each opening/closing timing to the discharge switching solenoid valve, and supplying it to each clutch by switching the discharge switching solenoid valve during forward/forward switching and gear shifting. A clutch operation hydraulic control device for a transmission, characterized in that the hydraulic pressure is adjusted to shorten the switching time for forward/reverse switching and gear shifting while alleviating impact.