JPH09287624A - Clutch control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably prevent the occurrence of engagement of a clutch during disconnection of a proportional solenoid valve under waiting for the starting of a vehicle and to prevent the occurrence of an engine stop. SOLUTION: An energization indication value (an indication voltage) from a CPU 8 is monitored by an indication voltage deciding part 12. A real current flowing through the coil 4a of a proportional solenoid valve 4 is monitored by a current zero deciding part 13. When, during waiting for the starting of a vehicle, a clutch is brought into a half clutch waiting state, it is decided that the coil 4a is disconnected. In this case, the current zero deciding part 13 immediately obtains a decision result that a real current flowing through the coil 4a is zero. An AND circuit 14 receives a decision result that energization indication is outputted and receives a decision result from the current zero deciding part 13, and outputs a drive command to a drive circuit 11. The output of the drive command effects immediate energization to a solenoid valve 5 for emergency and a clutch is disengaged before it is moved to engagement side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch control device suitable for use in a mechanical automatic transmission system.

[0002]

2. Description of the Related Art Conventionally, in a mechanical automatic transmission system of this type, a drive stage is determined according to a driving state of a vehicle, and a control command for the determined drive stage is attached to a clutch actuator and a gear shift. The shift stage of the transmission is automatically switched by applying the signal to the unit and controlling the clutch engagement / disengagement operation and the gear shift operation of the gear shift unit.
In this mechanical automatic transmission system, when the engine is running and the gear is engaged and the brake is applied and the vehicle is on standby, the pneumatic proportional solenoid valve is energized to operate the clutch actuator to operate the clutch. Some are in a half-clutch standby state. An example of this is
It is disclosed in Japanese Utility Model Laid-Open No. 3-35824 "Automatic transmission for vehicle", and, for example, in the specification, page 17, line 9-.
The description of the half clutch state is given on page 18, line 9.

[0003]

However, according to such a conventional mechanical automatic transmission system, when the pneumatic proportional solenoid valve (hereinafter, simply referred to as a proportional solenoid valve) is disconnected while the vehicle is on standby, the engine stall occurs. May occur. That is, when the proportional solenoid valve is disconnected, the exhaust port of the proportional solenoid valve is left open, the operating air pressure of the clutch actuator is reduced, the power piston is pushed back, and the clutch is brought into contact with the clutch from the half-clutch standby state. In this case, the clutch suddenly switches from the half-clutch state to the clutch-engaged state, so that engine stall occurs.

As a method of avoiding this, an emergency solenoid valve (hereinafter referred to as an emergency solenoid valve) is provided, and based on the clutch position detected by the clutch stroke sensor,
When the clutch position changes greatly in the contact direction while the vehicle is waiting to start, it is conceivable that the emergency electromagnetic valve is operated to supply operating air pressure to the clutch actuator to disconnect the clutch. However, in this method, since the disconnection of the proportional solenoid valve is detected based on the change in the clutch position, the disconnection detection timing is late, and the clutch is engaged even if the emergency solenoid valve is operated. You can't avoid that.

The present invention has been made in order to solve such a problem, and an object of the present invention is to make sure that the clutch is brought into contact with the disconnection of the proportional solenoid valve while the vehicle is on standby. (EN) Provided is a clutch control device which can be avoided to prevent engine stalling.

[0006]

In order to achieve such an object, in the first invention (the invention according to claim 1), an instruction to energize the first solenoid valve (proportional solenoid valve) is issued. If the first solenoid valve is not energized despite this, the second solenoid valve (emergency solenoid valve) is energized to operate the clutch actuator and disengage the clutch. It is the one.

According to the first aspect of the invention, while the vehicle is on standby,
When the first solenoid valve is disconnected while the clutch is in the half-clutch standby state, this causes "the first solenoid valve is energized despite the instruction to energize the first solenoid valve. Is detected in a short time, the second solenoid valve is immediately energized, the clutch actuator is activated, and the clutch is disengaged before moving to the contact side.

[0008] The second invention (the invention according to claim 2) is the first invention.
Of the solenoid valve (proportional solenoid valve) is provided with an energization instruction value monitoring means for monitoring the energization instruction value, and an actual current monitoring means for monitoring the actual current flowing through the first solenoid valve. When the actual current monitored by the actual current monitoring means is zero, even though there is an energization instruction value that exceeds the value, the second solenoid valve (emergency solenoid valve) is energized to operate the clutch actuator. The clutch is disengaged.

According to the second aspect of the present invention, when the vehicle is on standby,
When the first solenoid valve is disconnected while the clutch is in the half-clutch standby state, this causes "the first solenoid valve to operate even though the energization instruction value to the first solenoid valve exceeds the predetermined value. It is detected in a short time as "the actual current flowing is zero",
The second solenoid valve is immediately energized to operate the clutch actuator and disengage before the clutch moves to the contact side.

The third invention (the invention according to claim 3) is the first invention.
The solenoid valve (proportional solenoid valve) is provided with an energization instruction value monitoring means for monitoring the energization instruction value at a timing delayed by a predetermined amount, and an actual current monitoring means for monitoring the actual current flowing through the first solenoid valve. If the actual current monitored by the actual current monitoring means is zero, even though there is an energization instruction value exceeding the predetermined value in the indicated value monitoring means, the second solenoid valve (emergency solenoid valve) is energized. Then, the clutch actuator is operated and the clutch is disengaged.

According to the third aspect of the invention, while the vehicle is waiting to start,
When the first solenoid valve is disconnected while the clutch is in the half-clutch standby state, this causes "the first solenoid valve to operate even though the energization instruction value to the first solenoid valve exceeds the predetermined value. It is detected in a short time as "the actual current flowing is zero",
The second solenoid valve is immediately energized to operate the clutch actuator and disengage before the clutch moves to the contact side. In this case, by monitoring the energization instruction value for the first solenoid valve with a predetermined delay, the monitoring timing of the energization instruction value for the first solenoid valve and the first solenoid valve according to the energization instruction value are monitored. It is possible to eliminate the time difference between the actual current flowing and the monitoring timing.

The fourth invention (the invention according to claim 4) is the first invention.
An offset current supply means for causing an offset current to flow through the solenoid valve (proportional solenoid valve) and an actual current monitoring means for monitoring the actual current flowing through the first solenoid valve are provided to energize the first solenoid valve. If the actual current monitored by the actual current monitoring means is equal to or less than the offset current despite the instruction being given, the second solenoid valve (emergency solenoid valve) is energized to operate the clutch actuator. The clutch is disengaged.

According to the fourth aspect of the invention, when the vehicle is on standby,
When the first solenoid valve is disconnected when the clutch is in the half-clutch standby state, this is "monitored by the actual current monitoring means despite the fact that an instruction to energize the first solenoid valve has been issued. The state in which the actual current is less than or equal to the offset current "is detected in a short time, and the second solenoid valve is immediately energized to activate the clutch actuator and disengage before the clutch moves to the contact side. In this case, disconnection can be detected without using a component such as a voltage determination unit.

The fifth invention (the invention according to claim 5) is the fourth invention.
In the invention, the offset current is supplied to the first solenoid valve only when the energization is instructed. According to the fifth aspect, the offset current is supplied to the first solenoid valve only when the energization is instructed, so that it is possible to prevent unnecessary current from flowing in the normal rest state.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on embodiments. FIG. 2 is a diagram showing a main part of a mechanical automatic transmission system to which the present invention is applied. In the figure, 1 is a clutch lever, 2 is a clutch actuator that is connected to a power piston 2a via a link mechanism 2b connected to the clutch lever 1, and operates by linking to the operation of the clutch lever 1, and 3 is a link mechanism 2b. A clutch stroke sensor, which is arranged near the position to detect the clutch stroke, 4 is a proportional solenoid valve, 5 is an emergency solenoid valve,
6 is a double check valve, and 7 is an air tank.

When the power piston 2a moves to the left in FIG. 2, the clutch lever 1 rotates counterclockwise about the fulcrum 1a and the clutch is disengaged.
By moving the power piston 2a to the right in FIG. 2,
The clutch lever 1 rotates clockwise around the fulcrum 1a, and the clutch is brought into contact.

[First Embodiment] FIG. 1 is a block diagram (first embodiment) showing a main part of a control circuit for the proportional solenoid valve 4 and the emergency solenoid valve 5. In FIG.
Is a CPU, 9 is a PID calculator for performing PID calculation of the energization instruction value from the CPU 8, 10 is a drive circuit provided for the proportional solenoid valve 4, 11 is a drive circuit provided for the emergency solenoid valve 5, Tr1 and Tr2 are transistors, R1 is a resistor used as a current detection sensor, D1 is a flywheel diode, 4a is a coil of the proportional solenoid valve 4, and 5a is a coil of the emergency solenoid valve 5.

Reference numeral 12 denotes an instruction voltage determination unit that monitors the energization instruction value (instruction voltage) sent from the CPU 8 and determines whether or not the instruction voltage is a predetermined value or more. A current zero determination unit that monitors the current (feedback current) and determines whether or not this actual current is zero, 1
Reference numeral 4 denotes the determination result of the indicating voltage determination unit 12 and the current zero determination unit 1.
It is an AND circuit that receives the determination result in 3 as an input.

[Operation during Start Standby (Normal)] While the vehicle is on stand-by waiting for the vehicle to start by operating the engine and putting gears, the CPU 8
Sends a predetermined energization instruction value to the PID calculator 9 so as to put the clutch in the half-clutch standby state. The PID calculation unit 9
The energization instruction value from the CPU 8 is calculated by PID, and a PID signal corresponding to the energization instruction value is sent to the drive circuit 10. The drive circuit 10 turns on / off the transistor Tr1 based on the PID signal from the PID calculator 9, and supplies the coil 4a of the proportional solenoid valve 4 with a current having a value according to the energization instruction value from the CPU 8.

As a result, the proportional solenoid valve 4 has its coil 4
The opening degree is set according to the value of the current flowing in a, and the compressed air from the air tank 7 is given to the double check valve 6 via the proportional solenoid valve 4. At this time, since the emergency solenoid valve 5 is in the closed state, and the compressed air pressure from the proportional solenoid valve 4 is larger than the compressed air pressure from the emergency solenoid valve 5 to the double check valve 6, Compressed air is supplied to the clutch actuator 2. This allows
The power piston 2a of the clutch actuator 2 moves leftward, and the clutch lever 1 rotates counterclockwise about the fulcrum 1a. Then, the power piston 2a stops at a position corresponding to the compressed air pressure applied to the clutch actuator 2, whereby the clutch (not shown) is put in the half-clutch standby state.

[Operation during Standby Standby (at Abnormality)] It is assumed that the coil 4a of the proportional solenoid valve 4 shown in FIG. 1 is broken while the vehicle is on standby to start and the clutch is in the half-clutch standby state. In this case, the current zero determination unit 13 immediately obtains a determination result that the actual current flowing through the coil 4a is zero. This determination result is given to the AND circuit 14.

On the other hand, a predetermined energization instruction value is sent from the CPU 8 to the PID calculator 9 in order to put the clutch in the half-clutch standby state. The instruction voltage determination unit 12 uses this CP
The energization instruction value (instruction voltage) from U8 is monitored, and when the instruction voltage is equal to or higher than a predetermined value, the AND circuit 14 is provided with a determination result indicating that the energization instruction is issued.

Here, in the instruction voltage determination section 12, C
The predetermined value to be compared with the instruction voltage from PU8 is set as a value lower than the instruction voltage that allows the clutch to be in the half-clutch standby state. The clutch becomes disengaged as the command voltage from the CPU 8 increases, and the clutch disengages as the command voltage from the CPU 8 decreases. Therefore, if the CPU 8 outputs an instruction voltage to put the clutch in the half-clutch standby state while the vehicle is on standby, the instruction voltage determination unit 12 outputs a determination result indicating that the energization instruction has been issued.
Given to.

As a result, the AND circuit 14 determines that the energization instruction has been issued from the instruction voltage determination unit 12 and that the actual current flowing through the coil 4a from the current zero determination unit 13 is zero. The judgment result and the judgment result are given at the same time. The AND circuit 14 receives these both determination results,
A drive command for the emergency solenoid valve 5 is issued to the drive circuit 11. In response to the drive command from the AND circuit 14, the drive circuit 11 turns on the transistor Tr2 and causes a current to flow through the coil 5a of the emergency solenoid valve 5. This coil 5a
The solenoid valve 5 for emergency is opened by energizing the
Compressed air from is supplied to the double check valve 6 via the emergency solenoid valve 5.

At this time, the coil 4a of the proportional solenoid valve 4 is in a disconnected state, and the compressed air pressure from the emergency solenoid valve 5 becomes larger than the compressed air pressure from the proportional solenoid valve 4 to the double check valve 6. From, the compressed air from the emergency solenoid valve 5 is supplied to the clutch actuator 2. As a result, the power piston 2 of the clutch actuator 2
a moves to the left, the clutch lever 1 rotates counterclockwise around the fulcrum 1a, and is disengaged before the clutch moves to the contact side.

That is, according to the present embodiment, when the coil 4a of the proportional solenoid valve 4 is disconnected while the vehicle is on standby and the clutch is in the half-clutch standby state, this causes "energization to the proportional solenoid valve 4". It is detected in a short time that "the proportional solenoid valve 4 is not energized despite the instruction is issued", and the emergency solenoid valve 5 is immediately energized to operate the clutch actuator 2. The clutch is disengaged before the clutch moves to the contact side, the clutch engagement is reliably avoided, and the engine stall does not occur.

In this embodiment, the CPU 8
Monitors the drive command from the AND circuit 14 to the drive circuit 11 to the emergency solenoid valve 5, and after the drive command to the emergency solenoid valve 5 is issued, the emergency solenoid valve 5 is sent via the drive circuit 11. Control the energization to the emergency solenoid valve 5 and the proportional solenoid valve 4
The clutch is controlled as an alternative to.

[Second Embodiment] FIG. 3 is a block diagram (second embodiment) showing a main part of a control circuit for the proportional solenoid valve 4 and the emergency solenoid valve 5. In FIG.
The same reference numerals denote the same or equivalent components, and description thereof will be omitted. In this embodiment, the SH circuit 15 is provided between the PID calculation unit 9 and the drive circuit 10, the delay circuit 16 is provided in front of the instruction voltage determination unit 12, and the AND circuit 14 and the drive circuit 11 are flipped. -A flop circuit 17 is provided.

The S-H circuit 15 converts the PID signal from the PID calculator 9 into a pulse signal having a duty ratio corresponding to the energization instruction value, and supplies the pulse signal to the drive circuit 10. The delay circuit 16 gives the energization instruction value (instruction voltage) from the CPU 8 to the instruction voltage determination unit 12 at a timing delayed by a predetermined amount. The flip-flop circuit 17 holds a drive command from the AND circuit 14 to the drive circuit 11 to the emergency solenoid valve 5.

If the judgment result from the instruction voltage judgment section 12 to the AND circuit 14 is branched and given to the S-H circuit 15, and if this is the judgment result indicating that the energization instruction is issued, The "L" level of the pulse signal to the drive circuit 10 is increased by a predetermined amount.

The delay circuit 16 eliminates the time difference between the timing of monitoring the energization instruction value from the CPU 8 to the PID calculator 9 and the timing of monitoring the actual current flowing through the proportional solenoid valve 4 according to the energization instruction value. The delay amount is determined in accordance with the delay amount of the PID calculation unit 9, the SH circuit 15, the drive circuit 10, and the transistor Tr1 for energizing the proportional solenoid valve 4.

[Operation during start standby (during normal operation)] When the engine is operated and the gear is turned on and the vehicle is on standby to start, CP
U8 sends a predetermined energization instruction value to the PID calculator 9 so as to put the clutch in the half-clutch standby state. PID calculator 9
Calculates the energization instruction value from the CPU 8 by PID and sends a PID signal corresponding to the energization instruction value to the SH circuit 15. The S-H circuit 15 converts the PID signal from the PID calculator 9 into a pulse signal having a duty ratio according to the energization instruction value, and supplies the pulse signal to the drive circuit 10. The drive circuit 10 turns on / off the transistor Tr1 based on the pulse signal from the SH circuit 15, and supplies the coil 4a of the proportional solenoid valve 4 with a current having a value according to the energization instruction value from the CPU 8. .

As a result, the proportional solenoid valve 4 has its coil 4
The opening degree is set according to the current value flowing in a, compressed air from the air tank 7 is given to the double check valve 6 via the proportional solenoid valve 4, the clutch actuator 2 is operated, and the clutch is set to the half clutch standby state. It

[Operation during start standby (at the time of abnormality)] It is assumed that the coil 4a of the proportional solenoid valve 4 is disconnected while the clutch is in the half clutch standby state while the vehicle is on standby. In this case, the current zero determination unit 13 immediately obtains a determination result that the actual current flowing through the coil 4a is zero. This determination result is given to the AND circuit 14.

On the other hand, the CPU 8 outputs a predetermined energization instruction value to the PID calculator 9 in order to put the clutch in the half-clutch standby state. The energization instruction value (instruction voltage) from the CPU 8 to the PID calculation section 9 is given to the instruction voltage determination section 12 via the delay circuit 16 at a timing delayed by a predetermined amount. The instruction voltage determination unit 12 includes a delay circuit 16
Is compared with a predetermined value. Since the instruction voltage is equal to or higher than the predetermined value, the AND circuit 14 is provided with a determination result indicating that the energization instruction is issued.

As a result, the AND circuit 14 determines from the determination result that the energization instruction is issued from the instruction voltage determination unit 12 and the current zero determination unit 13 that the actual current corresponding to the energization instruction is zero. And the determination result of are given at the same time. In response to both judgment results, the AND circuit 14
Issues a drive command to the emergency solenoid valve 5 to the flip-flop circuit 17. Flip-flop circuit 17
Receives a drive command from the AND circuit 14, enters a set state, and sets its Q output to "H" level.

"H" of this flip-flop circuit 17
The Q output of the level is given to the drive circuit 11. The drive circuit 11 receives the "H" level Q output of the flip-flop circuit 17, turns on the transistor Tr2, and supplies a current to the coil 5a of the emergency solenoid valve 5. By energizing the coil 5a, the emergency solenoid valve 5 is opened, compressed air from the air tank 7 is given to the double check valve 6 through the emergency solenoid valve 5, the clutch actuator 2 is operated, and the clutch is in the contact side. Will be refused before moving to.

In this embodiment, the CPU 8
Monitors the Q output of the flip-flop circuit 17, sets the flip-flop circuit 17 in the reset state after the Q output becomes "H" level, and through the drive circuit 11, the emergency solenoid valve 5 To control the clutch by using the emergency solenoid valve 5 instead of the proportional solenoid valve 4.

[Third Embodiment] FIG. 4 is a block diagram (third embodiment) showing a main part of a control circuit for the proportional solenoid valve 4 and the emergency solenoid valve 5. In this embodiment, the PID calculation unit 9 responds to the energization instruction value from the CPU 8.
By adding a minute signal (offset voltage) so that the signal output including the above does not become zero, the offset current is always supplied to the proportional solenoid valve 4. In this case, R2, R
3 is a resistor, and one end of the resistor R3 is connected to a voltage source,
The other end is connected to the drive circuit 10. The PID calculator 9 is connected to the drive circuit 10 via the resistor R2, and the parts of the resistors R2 and R3 close to the drive circuit 10 are connected, so that the resistors R2 and R3 form an adder circuit. There is. Further, the drive circuit 10 is composed of a comparator.

Based on such a configuration, the CPU 8 to P
When an energization instruction signal is sent to the ID calculation unit 9, the output of the PID calculation unit 9 becomes high level and the output side of the drive circuit 10 becomes low level. As a result, the transistor T
When r1 is turned on, the coil 4a of the first solenoid valve 4 is energized to open a predetermined opening degree and the air from the air tank 7 is sent to the double check valve 6. Further, in the non-energized state, the output of the PID calculation unit 9 becomes a low level, the drive circuit 10 is supplied with a current through the resistor R3, and the proportional electromagnetic valve 4 is offset by a small current through the transistor Tr1. Apply current.

As a result, the current zero determination unit 13 detects the disconnection of the proportional solenoid valve 4 depending on whether or not the offset current at the time of non-energization can be detected without providing the instruction voltage determination unit 12 shown in FIG. can do. By performing the process in the PID calculator 9 in the CPU 8,
The calculation unit 9 can be omitted. In this case, CP
This can be dealt with only by making the energization instruction value from U8 to the drive circuit 10 not zero.

[Fourth Embodiment] FIG. 5 is a block diagram (fourth embodiment) showing a main part of a control circuit for the proportional solenoid valve 4 and the emergency solenoid valve 5. In this embodiment, an offset signal is output only when the energization instruction value in the CPU 8 is equal to or greater than a predetermined value, or when the proportional solenoid valve 4 is operated, and the offset voltage is output based on the offset signal.
I am trying to give it to 0.

That is, in FIG. 4, a current flows through the coil 4a of the proportional solenoid valve 4 regardless of the energized state, which is not preferable for saving power. For this reason, FIG. 5 shows the operation for supplying the offset current only when the energization instruction is given from the CPU 8. In this case, a high-level bias voltage is sent from the CPU 8 to one end of the series body of the resistors R4 and R5 connected in series only when an energization instruction is issued. As a result, when a current is supplied from the connection point of the resistors R4 and R5 via the resistor R3, an offset current which is a minute current flows through the proportional solenoid valve 4 via the transistor Tr1 as in the case of FIG. As a result, in the normal sleep state, unnecessary current does not flow.

[0044]

As is apparent from the above description, according to the present invention, when the first solenoid valve (proportional solenoid valve) is disconnected while the vehicle is on standby and the clutch is in the half clutch standby state. , Which is detected in a short time as "a state in which the first solenoid valve is not energized even though the first solenoid valve is energized," the second solenoid valve (emergency The solenoid valve will be immediately energized and the clutch actuator will be activated, and the clutch will be disengaged before moving to the contact side. Will be things.

[Brief description of drawings]

FIG. 1 is a block diagram (first embodiment) showing a main part of a control circuit for a proportional solenoid valve and an emergency solenoid valve.

FIG. 2 is a diagram showing a main part of a mechanical automatic transmission system to which the present invention is applied.

FIG. 3 is a block diagram (second embodiment) showing a main part of a control circuit for a proportional solenoid valve and an emergency solenoid valve.

FIG. 4 is a block diagram (third embodiment) showing a main part of a control circuit for a proportional solenoid valve and an emergency solenoid valve.

FIG. 5 is a block diagram (fourth embodiment) showing a main part of a control circuit for a proportional solenoid valve and an emergency solenoid valve.

[Explanation of symbols]

1 ... Clutch lever, 2 ... Clutch actuator, 3
... Clutch stroke sensor, 4 ... Proportional solenoid valve, 5 ... Emergency solenoid valve, 6 ... Double check valve, 7 ... Air tank, 8 ... CPU, 9 ... PID calculator, 10, 11 ... Drive circuit, 12 ... Indication voltage judgment Part, 13 ... Current zero determination part, 1
4 ... AND circuit, 15 ... SH circuit, 16 ... Delay circuit, 17 ... Flip-flop circuit.

Claims (5)

[Claims] 1. A clutch control device for energizing a first electromagnetic valve to operate a clutch actuator to put a clutch in a half-clutch standby state while the engine is operating and a gear is turned on and the vehicle is on standby to start. When the second solenoid valve connected to the clutch actuator and the first solenoid valve are not energized despite the instruction to energize the first solenoid valve, A clutch control device comprising: an emergency control unit that energizes a second solenoid valve to operate the clutch actuator to disconnect the clutch. 2. The emergency control means according to claim 1, wherein the emergency control means monitors an energization instruction value for the first solenoid valve, and an actual current flowing through the first solenoid valve. If the actual current monitored by the actual current monitoring unit is zero, even though the current monitoring unit and the energization instruction value monitoring unit have an energization instruction value exceeding a predetermined value, the second solenoid valve is activated. And a control means for activating the clutch actuator to disengage the clutch. 3. The emergency control means according to claim 1, wherein the emergency control means monitors the energization instruction value to the first solenoid valve at a timing delayed by a predetermined amount, and the emergency control means flows to the first solenoid valve. When the actual current monitored by the actual current monitoring means is zero, although the actual current monitoring means for monitoring the actual current and the energization instruction value monitoring means have an energization instruction value exceeding a predetermined value, A clutch control device comprising: a control unit that energizes a second solenoid valve to operate the clutch actuator to disconnect the clutch. 4. The offset current supply means according to claim 1, further comprising an offset current supply means for causing an offset current to flow through the first electromagnetic valve, wherein the emergency control means monitors an actual current flowing through the first electromagnetic valve. If the actual current monitored by the actual current monitoring means is equal to or less than the offset current, the second current is monitored by the actual current monitoring means. And a control means for actuating the clutch actuator to disengage the clutch by energizing the solenoid valve. 5. The clutch control device according to claim 4, wherein the offset current supply unit is driven only when an energization instruction is made to operate to supply an offset current to the first solenoid valve.