JPH10291432A - Braking device for torque converter vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a brake fade phenomenon and an abnormal increase in temperature of oil of a torque converter by minimizing overlap between a drive torque and a brake torque when a vehicle is driven by an inching operation. SOLUTION: An inching valve 10 which can be selected in three positions is provided in a passage 15 for supplying hydraulic fluid to wet clutches 7a, 7b from a hydraulic pump 3. A brake valve 8 which can be selected in two positions of a braking position and a releasing position is provided in a passage 22 for supplying hydraulic fluid to a brake circuit 9. The brake valve 8 is controlled by pilot hydraulic pressure and is provided with a brake passage 24 for supplying hydraulic pressure for holding the brake valve 8 at the braking position against the energizing force of a spring 23 in a state in which the passage 24 communicates with a clutch 7a side by the inching valve 10. In a state in which the inching valve 10 can supply the hydraulic fluid to the clutches 7a, 7b, the brake valve 8 is held at the braking position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque converter for transmitting the output of an engine at a variable speed and a braking device for a torque converter vehicle for transmitting the torque of the torque converter to an output shaft via a wet clutch.

[0002]

2. Description of the Related Art Conventionally, an industrial vehicle as a torque converter vehicle of this type, particularly a forklift, is equipped with an inching device for performing inching travel.
In the traveling hydraulic circuit, as shown in FIG. 6, hydraulic oil discharged from a hydraulic pump 51 rotated by an engine 50 is supplied to a torque converter 53 via a regulator valve 52, and the inching valve 54 It is supplied to the automatic transmission 57 via the switching valves 55 and 56.

As shown in FIG. 7, an automatic transmission 57 is provided with a forward input shaft 58, a reverse input shaft 59, and an output shaft 60. Forward input shaft 5
8, the torque of the torque converter 53 is transmitted. A propeller shaft (not shown) is connected to the output shaft 60, and transmits power to a differential.

The forward input shaft 58 includes a forward input shaft 58.
61 and input shaft 58 for forward rotation
There is provided a forward gear 62 which makes a relative rotation with respect to. Between the drum 61 and the forward gear 62, a wet multi-plate clutch 63 for connecting and disconnecting power is provided. The wet-type multi-plate clutch 63 connects or separates a driven plate 64 that rotates integrally with the drum 61 and a clutch disk 65 that rotates integrally with the forward gear 62 via a piston 66 so that the power between the drum 61 and the forward gear 62 is increased. Connection or disconnection.

[0005] The piston 66 includes a drum 61 and a forward gear 62.
And slidably provided in the thrust direction. The forward input shaft 58 is provided with a hydraulic path 67 for supplying hydraulic oil for moving the piston 66 toward the forward gear 62. The piston 66 is connected to the return spring 6
8 urges in a direction away from the forward gear 62. Therefore, when hydraulic oil is supplied to the hydraulic path 67,
When the piston 66 pushes the driven plate 64 toward the forward gear 62, the driven plate 64 and the clutch disk 65 are pressed against each other, and when the hydraulic pressure supplied to the hydraulic path 67 is drained, the driven plate 64 and the clutch disk 65 The connection is to be terminated. The reverse input shaft 59 is also provided with a wet multi-plate clutch 69 having the same configuration.

As shown in FIG. 6, the switching valves 55 and 56 are switched by an operation of an electromagnetic switching valve 70 which is controlled by operating a shift lever (not shown). Hydraulic oil is supplied to the wet-type multi-plate clutch 63 of the input shaft 58 for use, and hydraulic oil is supplied to the wet-type multi-plate clutch 69 of the input shaft 59 for reverse when traveling in reverse.

[0007] A brake valve 74 is provided in the middle of a pipe 73 for supplying hydraulic oil to the brake circuit 72. When the brake pedal 75 is operated, the brake valve 74 is switched to a position where hydraulic oil can be supplied to the brake circuit 72. The inching valve 54 is operated to switch to the three positions. In the free state, as shown in FIG. 6, the automatic transmission 57 is maintained in a state capable of supplying hydraulic oil, and when the inching pedal 76 is depressed to the maximum amount, the automatic transmission 57 is automatically operated. It is arranged at a position where supply of hydraulic oil to transmission 57 is cut off.
Further, when the inching pedal 76 is depressed to the intermediate position, the hydraulic pressure supplied to the automatic transmission 57 is disposed at an inching position where the hydraulic pressure is released to the oil tank 77 via the throttle 54a.

When the brake pedal 75 alone is depressed, the brake pedal 75 operates independently of the inching pedal 76. However, when the inching pedal 76 is depressed, the inching pedal 76 and the brake pedal 7
5 can be interlocked. That is, the inching pedal 76 is moved (operated) independently of the brake pedal 75 until it reaches the inching position, but after the inching position, the brake pedal 75 moves integrally with the inching pedal 76. .

Therefore, when the brake pedal 75 is depressed, the automatic transmission 57
Irrespective of the state, the braking torque is generated while the driving torque is transmitted to the tires while the vehicle is running. In the case where braking is performed by operating the inching pedal 76, when the inching pedal 76 is depressed, the driving torque gradually decreases, and when a certain point is reached, a braking torque is generated.

[0010]

However, in the above-mentioned conventional apparatus, the inching pedal 76 is engaged with the brake pedal 75 during the movement so that it can move integrally with the brake pedal.
Hysteresis phenomenon of the braking torque is large due to the hydraulic characteristics of the brake valve. As a result, an overlap region (a hatched region in FIG. 5) of the braking torque and the driving torque due to the operation of the inching pedal 76 as shown in FIG. 5 is generated, and when the braking and the inching are repeated, the brake fade phenomenon and the torque converter 53 An abnormal rise in oil temperature may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to minimize the overlap between the driving torque and the braking torque during inching running to reduce the brake fade phenomenon and the temperature of the torque converter oil. An object of the present invention is to provide a braking device for a torque converter vehicle that can suppress an abnormal rise.

[0012]

To achieve the above object, according to the first aspect of the present invention, a torque converter for shifting and transmitting the output of an engine and a torque of the torque converter are transmitted via a wet clutch. In a torque converter vehicle that transmits to the output shaft, it is provided in a pipeline that supplies hydraulic oil from a hydraulic pump to the clutch, and the flow rate of hydraulic oil from the hydraulic pump to the clutch can be maintained in a state where the clutch is completely connected And a second position for maintaining the clutch in the half-clutch state, and a third position for interrupting the supply of hydraulic oil to the clutch and guiding the hydraulic pressure of the clutch to the drain. Inching valve that can be switched to a position, a pedal that operates the inching valve, and a pipeline that supplies hydraulic oil from the hydraulic pump to the brake circuit. A brake valve capable of switching between a braking position in which hydraulic oil can be supplied to the brake circuit, a brake release position in which supply of hydraulic oil to the brake circuit is interrupted, and the brake circuit communicates with the oil tank; An urging means for urging the valve to the brake release position side, and an end thereof for supplying a hydraulic pressure for holding the brake valve in the braking position against the urging force of the urging means, actuates the clutch. And a braking line connected to the clutch side of the oil supply line from the inching valve.

According to a second aspect of the present invention, in the first aspect of the present invention, the wet clutch is configured to be switchable between forward and reverse, and a pipeline for supplying hydraulic oil to the clutch is provided with the brake pipe. On the clutch side from the connection position of the road, a branch is made into a forward pipeline and a reverse pipeline, and supply of hydraulic oil to the forward pipeline and the reverse pipeline is switched based on operation of a shift lever. It is controlled via a controlled three-position switching solenoid valve.

According to a third aspect of the present invention, in the first or second aspect, the braking conduit is
Switching between a first position in which the brake line is kept in communication and a second position in which the brake valve side of the brake line communicates with the oil tank and shuts off the hydraulic oil supply line side. A pedal operated switching valve is provided.

Therefore, according to the first aspect of the present invention,
The torque of the torque converter is transmitted to the output shaft via a wet clutch. Supply of hydraulic oil (hydraulic pressure) from the hydraulic pump to the wet clutch is controlled by pedal operation of an inching valve switchable to three positions. A brake valve for controlling the supply of the hydraulic oil to the brake circuit is provided downstream of the inching valve of the pipeline for supplying the hydraulic oil to the clutch, that is, via a braking pipeline branched from the pipeline on the clutch side. Switching is controlled by the supplied hydraulic pressure (pilot pressure). When the inching pedal is in the free state or depressed to the inching position, the brake valve is held at a braking release position that cuts off supply of hydraulic oil to the brake circuit and connects the brake circuit to the oil tank.

When the inching pedal is in a free state, the flow rate of hydraulic oil to the clutch is an amount that can hold the clutch in a completely connected state. Therefore, when the shift lever is switched to the traveling position, the vehicle normally travels. When the inching pedal is depressed halfway, the inching valve is switched to a state in which the flow rate of the operating oil to the clutch is such that the clutch is maintained in the half-clutch state. In this state, the vehicle runs in inching.

When the inching pedal is depressed to the maximum amount, the supply of hydraulic oil to the clutch is cut off and the hydraulic pressure of the clutch drops to the drain. Further, the hydraulic pressure (pilot pressure) supplied to the brake valve also drops to the drain, and the brake valve is disposed at a braking position where hydraulic oil can be supplied to the brake circuit. That is, the operating oil pressure of the clutch and the operating oil pressure of the brake are controlled in conjunction with each other by an inching valve operated by an inching pedal.

According to the invention of claim 2, according to claim 1,
In the invention described in (1), hydraulic oil is supplied to the wet clutch via a forward pipeline or a reverse pipeline. The supply of hydraulic oil to the forward pipeline or the reverse pipeline is controlled via a three-position switching electromagnetic valve that is switched based on the operation of the shift lever.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the pilot pressure to the brake valve is changed by a switching operation of a switching valve operated by a pedal independently of the inching valve. Is also controlled. When the pedal is depressed, the switching valve is switched to a second position that connects the brake valve side of the brake line to the oil tank and shuts off the hydraulic oil supply line side. Therefore, when the pedal is depressed, the hydraulic oil is supplied to the brake circuit even when the inching pedal is not depressed.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment in which the present invention is embodied in a braking device for a forklift as a torque converter vehicle.
1 will be described with reference to FIGS. 1 and 2. FIG.

As shown in FIG. 1, hydraulic oil pumped from an oil tank 3 by a hydraulic pump 2 driven by an engine 1 is supplied to a torque converter 5 via a regulator valve 4 and a control valve 6 for traveling. The automatic transmission 7 is supplied to a brake circuit 9 via a brake valve 8. The automatic transmission 7 is configured basically in the same manner as the conventional device, and includes a forward wet clutch 7a and a reverse wet clutch 7b (hereinafter, simply referred to as clutches 7a and 7b).

The control valve 6 includes an inching valve 10, switching valves 11, 12 and a three-position switching solenoid valve 13. The inching valve 10 is provided in a pipe 15 connected to a hydraulic oil supply pipe 14 connected to the hydraulic pump 2. Inching valve 10 is for pedal operation 3
It consists of a port 3 position switching valve and has an inching pedal 16
And the urging force of the spring 17,
The spool can be switched between a first position (a position), a second position (b position), and a third position (c position). When the inching valve 10 is switched to the first position, the inching valve 10 communicates with the pipe line 15 so that the clutch 7a,
The flow rate of the working oil to 7b is an amount that can hold the clutches 7a and 7b in a completely connected state. In the state where the inching valve 10 is switched to the second position, the line 1
5 and the line 15 are communicated with the oil tank 3 via the throttle 10a, and the flow rate of the working oil to the clutches 7a and 7b is an amount for maintaining the clutches 7a and 7b in the half-clutch state. When the inching valve 10 is located at the third position, the supply of hydraulic oil to the clutches 7a and 7b is cut off and the hydraulic pressure of the clutches 7a and 7b is led to the drain (oil tank).

The pipeline 15 is branched into a forward pipeline 15a and a reverse pipeline 15b on the clutch 7a, 7b side of the inching valve 10, and the switching valve 1 is connected to the forward pipeline 15a.
1 is provided with a switching valve 12 in the reverse passage 15b. Each of the switching valves 11 and 12 is a two-position switching valve operated by pilot pressure. When the pilot pressure is supplied, the switching valves 11 and 12 are maintained in a state (position a) in which the forward pipeline 15a or the reverse pipeline 15b is communicated. In a state where the pilot pressure is not supplied, the supply of the hydraulic oil to the clutches 7a and 7b is shut off, and the hydraulic pressure of the clutches 7a and 7b is maintained at a state (position b) where the hydraulic pressure is guided to the drain (oil tank). Note that an accumulator 18 is connected to the pipe line 15 on the upstream side of the inching valve 10, and a throttle 19 is provided on the upstream side of the connection position of the accumulator 18.

As the three-position switching solenoid valve 13, a four-port valve is used. The three-position switching solenoid valve 13 has three positions, a position (forward position), b position (neutral position), and c position (reverse position), based on a drive signal from a controller 20 provided on the vehicle body of the forklift (not shown). To control the supply and cutoff of the pilot pressure to both switching valves 11 and 12. The three-position switching solenoid valve 13 is connected to a hydraulic oil supply line 14, and hydraulic oil for supplying the pilot pressure is supplied from the hydraulic oil supply line 14.

The controller 20 receives output signals from the shift lever switches LS1 and LS2. The shift lever switches LS1 and LS2 are constituted by limit switches. The forward shift lever switch LS1 is turned on when the shift lever 21 is operated to the "forward" position, and is turned off at other times. The reverse shift lever switch LS2 is turned on when the shift lever 21 is operated to the "reverse" position, and is turned off at other times. Therefore, when the shift lever 21 is in the "neutral (neutral)" position, both switches LS1 and LS2 output an off signal. The controller 20 outputs a drive signal (excitation demagnetization signal) to the solenoids 13a and 13b of the three-position switching solenoid valve 13 based on the output signals of both shift lever switches LS1 and LS2.

Pipe line 2 for supplying hydraulic oil to brake circuit 9
2 is branched from a hydraulic oil supply line 14, and a brake valve 8 is provided on the way. Brake valve 8 is 2
A braking position (a position) which is constituted by a position switching valve and can supply hydraulic oil to the brake circuit 9;
It is configured to be able to switch to a brake release position (position b) for interrupting supply to the vehicle. The brake valve 8 allows the brake circuit 9 to communicate with the oil tank 3 when the brake is released. The brake valve 8 includes a spring 23 as an urging means for urging a spool (not shown) toward the brake release position (position b). The brake valve 8 is connected to a first end of a brake pipe 24 for supplying a hydraulic pressure (pilot pressure) for holding the spool at a braking position against the urging force of a spring 23. The second end of the braking line 24 is a line 1 for supplying hydraulic oil to the clutches 7a and 7b.
5 is connected to the clutch side of the inching valve 10. The biasing force of the spring 23 is set to a value smaller than the hydraulic pressure of the braking pipeline 24 when the inching valve 10 is located at the position b.

Next, the operation of the device configured as described above will be described. When the engine 1 is rotating, hydraulic oil is supplied to the hydraulic oil supply line 14, and the inching valve 10,
Hydraulic oil is supplied to the three-position switching solenoid valve 13 and the brake valve 8. When the inching pedal 16 is in the free state, the inching valve 10 is held at the position a shown in FIG. Become. When the shift lever 21 is switched to the "forward" position in this state, the three-position switching solenoid valve 13 is switched to the "a" position, the pilot pressure is supplied to the switching valve 11, and the switching valve 11 is moved to the "a" position, that is, the forward conduit. 15a. Then, the working oil is supplied to the forward clutch 7a, and the clutch 7a is completely connected, so that the vehicle travels forward. Shift lever 21 is "reverse"
When the position is switched to the position, the three-position switching solenoid valve 13 is switched to the position c, the pilot pressure is supplied to the switching valve 12, and the switching valve 12 is switched to the position a, that is, the position for communicating the reverse passage 15b. And the reverse clutch 7
When the hydraulic oil is supplied to b and the clutch 7b is completely connected, the vehicle travels backward.

When the inching pedal 16 is in the free state, the pilot pressure is supplied to the brake pedal 8 via the braking pipe 24, and the brake pedal 8 is operated by the hydraulic oil as shown in FIG. The supply to the brake circuit 9 is cut off, and the brake circuit 9 is maintained in a state of communicating with the oil tank 3. Therefore, no hydraulic oil is supplied to the brake circuit 9.

When the inching pedal 16 is depressed halfway (to the inching position), the inching valve 10 is depressed.
Is switched to a position b where the pipe 15 communicates with the oil tank 3 via the throttle 10a. In this state, the clutch 7
A state is reached in which the flow rate of the hydraulic oil to a and 7b is such that the clutches 7a and 7b are maintained in the half-clutch state. As a result, the driving torque transmitted via the clutches 7a and 7b decreases, and the vehicle performs inching running. Also in this state, the brake valve 8 is held at the position b shown in FIG. 1 by the pilot pressure of the hydraulic oil supplied to the braking pipeline 24. Therefore, no braking torque acts.

When the inching pedal 16 is further depressed from the inching position to the maximum depressing position, the inching valve 10 is switched to the position c, and the supply of hydraulic oil to the clutches 7a and 7b is cut off. The pipe line 15 on the clutch 7a, 7b side from 10 is in a state of communicating with the oil tank 3. Therefore, the hydraulic pressure supplied to the clutches 7a and 7b drops to the drain. The hydraulic pressure (pilot pressure) supplied to the brake valve 8 also drops to the drain, and the brake valve 8 is disposed at a braking position (a position) where the hydraulic oil can be supplied to the brake circuit 9 by the urging force of the spring 23. You. As a result, the operating oil in the pipe line 22 is supplied to the brake circuit 9, and a state where a braking torque is applied is established.

That is, the operating oil pressure of the clutches 7a and 7b and the operating oil pressure for switching the brake valve 8 are controlled in conjunction with each other by the inching valve 10 operated by the inching pedal 16. As a result, inching pedal 1
FIG. 2 shows the relationship between the operation stroke No. 6 and the driving torque and the braking torque. That is, unlike the conventional device,
There is no overlap area between the braking torque and the driving torque. Therefore, even if braking and inching travel are repeated,
The occurrence of the brake fade phenomenon and the abnormal rise in the oil temperature of the torque converter 5 are prevented.

This embodiment has the following effects. (A) A state in which the pilot pressure of the brake pedal 8 is controlled by the inching valve 10 for controlling the supply of hydraulic oil to the clutches 7a and 7b, and the braking force is applied in a state where the hydraulic pressure to the clutches 7a and 7b is drained. Thus, there is no overlap region between the braking torque and the driving torque. As a result, even if the braking and the inching running are repeated, it is possible to prevent the occurrence of the brake fade phenomenon and the abnormal rise in the oil temperature of the torque converter 5.

(B) A braking operation can be performed by operating the inching pedal 16, and there is no need to provide an independent brake pedal, and it is not necessary to secure a space for installing the brake pedal.

(C) When the braking is performed, the supply of the hydraulic oil to the clutches 7a and 7b is always shut off, so that the braking operation works effectively. (D) The supply of the hydraulic oil to the forward pipe 15a and the reverse pipe 15b for supplying the hydraulic oil for connecting and disconnecting the clutches 7a and 7b is switched and controlled based on the operation of the shift lever 21. Since the clutch 7 is controlled through the position switching solenoid valve 13, the clutch 7 can be reliably operated by operating the shift lever 21.
a, 7b can be turned on and off (connection, cutoff).

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. In this embodiment, the pilot pressure to the brake valve 8 is equal to the inching valve 10.
This embodiment is different from the above-described embodiment in that control can also be performed by a switching operation of a switching valve that is operated independently by a pedal. Other configurations are the same as those of the above-described embodiment, and the same portions are denoted by the same reference numerals and detailed description will be omitted. In FIG. 3, illustration of the controller 20, the shift lever 21, and the like is omitted.

A switching valve 2 operated by a pedal is provided in the braking line 24.
5 are interposed. The switching valve 25 is in a first position for holding the brake line 24 in a communicating state, and in a second position for connecting the brake valve 8 side of the brake line 24 to the oil tank 3 and shutting off the line 15 side. Is switched to
The switching valve 25 is biased and held at a first position by a spring 26, and the second operation is performed by depressing a brake pedal 27.
The position can be switched to the position.

Therefore, in the state where the brake pedal 27 is not operated, the same operation and effect as those of the first embodiment are exerted. In this embodiment, when the brake pedal 27 is depressed, the switching valve 25 is switched to the second position, and the pilot pressure supplied to the brake valve 8 drops to the drain. As a result, even when the inching pedal 16 is not depressed, the operating oil is supplied to the brake circuit 9 and the brake can be applied regardless of the operation of the inching pedal 16. Since the switching valve 25 is a two-position switching valve, it is possible to reduce the time until braking is applied by pedal operation, as compared with the inching valve 10 using a three-position switching valve. Therefore, in the case of sudden braking,
The time to stop can be reduced. In addition, by using the inching pedal 16 together, the brake can be applied with the driving torque reduced.

The embodiments are not limited to the above-described embodiments, but may be embodied as follows, for example. (1) As shown in FIG. 4, a three-position switching solenoid valve 13 is connected to the forward pipeline 15a and the reverse pipeline 15b to supply hydraulic oil to the forward pipeline 15a and the reverse pipeline 15b. The control may be directly performed by the three-position switching solenoid valve 13. The pipe 22 is common to the pipe 14. In this case, the configuration is simpler than in the above two embodiments.

(2) In the second embodiment, instead of the switching valve 25, the second operation is performed by operating the brake pedal 27.
When the position is switched to the position, the switching valve having a configuration in which both the brake valve 8 side and the pipeline 15 side of the pipeline 24 can communicate with the oil tank 3 is used. In this case, when the brake pedal 27 is depressed, the clutches 7a, 7
The hydraulic pressure supplied to b also drops to the drain, and the driving torque decreases even if the inching pedal 16 is not operated,
No wasted power consumption during braking.

(3) Instead of the three-position switching solenoid valve 13,
A manually operated three-position switching valve operated by the shift lever 21 may be used. In this case, the controller 26 and the shift lever switches LS1 and LS2 become unnecessary, and 3
The configuration is simpler than when the position switching solenoid valve 13 is used.

(4) A hydraulic circuit for supplying hydraulic oil to the torque converter 5 may be provided separately. (5) The case where the present invention is embodied in a forklift is shown.
It may be embodied in other industrial vehicles.

The technical ideas (inventions) other than those described in the claims, which have been grasped from the above embodiments, will be described below together with their effects. (1) In the invention described in claim 1 or 2,
A pedal operation switchable by operating a brake pedal between a first position for holding the brake line in communication with the brake line and a second position for connecting the brake line to the oil tank. Are interposed. In this case, the braking operation can be performed independently of the inching pedal by operating the brake pedal, and the time from the time of braking by the operation of the inching pedal to the time of stopping can be shortened.

[0043]

As described in detail above, claims 1 to 3 are described.
According to the invention described in the above, the overlap between the driving torque and the braking torque during inching traveling is minimized,
The brake fade phenomenon and the abnormal rise in the temperature of the torque converter oil can be suppressed.

According to the second aspect of the present invention, the forward / backward movement is switched by the connection / separation of the wet clutch. According to the third aspect of the present invention, the brake can also be applied by depressing a pedal independent of the inching pedal.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram of a first embodiment.

FIG. 2 is a diagram showing a relationship between a stroke of an inching pedal and a torque.

FIG. 3 is a main part hydraulic circuit diagram of a second embodiment.

FIG. 4 is a main part hydraulic circuit diagram of another embodiment.

FIG. 5 is a diagram showing torque characteristics of a conventional device.

FIG. 6 is a hydraulic circuit diagram of a conventional device.

FIG. 7 is a partially omitted sectional view showing an automatic transmission.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Hydraulic pump, 3 ... Oil tank, 5
... Torque converter, 7a, 7b ... Wet clutch, 8 ...
Brake valve, 9: Brake circuit, 13: 3-position switching solenoid valve, 14: Hydraulic oil supply line, 15, 22: Line, 1
5a: forward pipeline, 15b: reverse pipeline, 16: inching pedal, 21: shift lever, 23: spring as urging means, 24: brake pipeline, 25: switching valve, 2
7 ... Brake pedal.

Claims (3)

[Claims] 1. A torque converter for shifting the output of an engine and transmitting the output, and a torque converter vehicle for transmitting the torque of the torque converter to an output shaft via a wet clutch, supplying hydraulic oil from a hydraulic pump to the clutch. A first position that is provided in the pipeline and that is a first position at which the flow rate of hydraulic oil from a hydraulic pump to the clutch is an amount that can be maintained in a state in which the clutch is completely connected; An inching valve switchable to a second position, a third position for interrupting the supply of hydraulic oil to the clutch and guiding the oil pressure of the clutch to the drain, a pedal for operating the inching valve, and a hydraulic pump. A brake position that is provided in the pipeline that supplies hydraulic oil to the brake circuit from the A brake valve capable of switching to a brake release position for interrupting supply to the brake circuit and communicating the brake circuit with the oil tank; biasing means for biasing the brake valve toward the brake release position; and the brake valve. The end thereof is connected to the clutch side from the inching valve of a pipeline for supplying hydraulic oil to the clutch in order to supply a hydraulic pressure for holding the hydraulic pressure in the braking position against the urging force of the urging means. A braking device for a torque converter vehicle including a braking pipeline. 2. The wet-type clutch is configured to be switchable between forward and backward, and a pipeline for supplying hydraulic oil to the clutch includes a forward pipeline and a reverse pipeline on the clutch side from a connection position of the braking pipeline. And supply of hydraulic oil to the forward pipeline and the reverse pipeline is controlled via a three-position switching solenoid valve that is switched based on the operation of a shift lever. 2. The braking device for a torque converter vehicle according to claim 1. A first position for holding the brake line in communication with the brake line; a brake valve side of the brake line communicating with an oil tank; and a hydraulic oil supply line. 3. The braking device for a torque converter vehicle according to claim 1, further comprising a pedal-operated switching valve that is switched to a second position for shutting off a pipe side of the vehicle.