JPS5855004B2 - Drive force transmission device for work vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a driving force transmission device for a working vehicle.
A work device for medium-high speed travel and a work device for low-speed travel are attached to a vehicle body equipped with a travel device, and each of the work devices is driven via a fluid pressure actuator, and a travel device is installed between the engine and the travel device. A working vehicle configured to have a gear transmission and a traveling fluid pressure drive mechanism interposed in parallel to selectively transmit driving force from the gear transmission or the fluid pressure drive mechanism to drive a traveling device. This invention relates to a driving force transmission device.

The above-mentioned driving force transmission device uses a fluid pressure drive mechanism for traveling at low speed when the work vehicle is driven to travel and requires high torque power transmission, for example when performing work with a snow removal work device etc. When working with work equipment that can travel and transmit power with a relatively small torque, such as during transportation work, the system is configured so that the power can be transmitted by switching the transmission method so that the work can be efficiently carried out at medium to high speeds using transmission from a gear transmission. However, conventionally, the drive power transmission device of this type of work vehicle supplies fluid pressure from a fluid pressure drive source through a switching valve, and by switching the valve, it can be used as a working device for medium- to high-speed traveling or for low-speed traveling. In addition to driving each working device separately9, the gear transmission and fluid pressure drive mechanism were individually turned on and off using operating levers and switching valves, so there were many operating systems for transmitting driving force, making it difficult to operate. Not only is this cumbersome, there is a risk of erroneous operation, and there are also many operating systems, resulting in poor productivity.

Therefore, as an improved version of this type,
As shown in Japanese Patent No. 297519, among the above-mentioned driving force transmission devices, there is one in which a hydraulic drive mechanism for traveling and a gear transmission are linked, but this structure The motor as a drive mechanism is connected to the motor through a flow path, and a mechanical transmission clutch operated by an operating lever is provided on the motor drive shaft, and a pilot flow path is provided in the middle of the flow path between the fluid pressure drive source and the motor. The pilot flow path is connected to a fluid pressure cylinder for engaging and disengaging a power transmission clutch installed on the output shaft from the gear transmission, and this function is activated when the clutch provided on the motor drive shaft is disengaged by an operating lever. Since the motor is under an extremely light load, the pressure in the pilot flow path decreases, and as the pressure decreases, the transmission clutch on the gear transmission side is engaged, and the clutch on the motor side is also engaged. As the load increases on the motor, the pilot pressure increases, and when the pilot pressure reaches a certain level, the transmission clutch on the gear transmission side disengages.

This structure has the advantage of being able to switch the transmission of drive power between the hydraulic drive mechanism (motor) for traveling and the gear transmission with a single operation of the clutch operating lever, but it simplifies switching between the working device and the gear transmission. However, in this case, when the clutch on the motor side is disengaged, the motor is always in an extremely light load state, so the gear transmission There is no problem with only the side clutch being engaged, but this may occur when the motor side clutch is engaged and the pilot pressure is below a certain level, for example when driving downhill. In the case of a light load or no load condition, the clutch on the gear transmission side will be engaged at the same time as the clutch on the motor side, causing trouble in the transmission device and causing a very inconvenient situation.

The purpose of the present invention is to solve the above-mentioned drawbacks and inconvenient situations.The present invention reliably prevents troubles from occurring in the driving transmission system, simplifies the transmission system switching operation, and avoids erroneous operation. The purpose is to provide a driving force transmission device for a vehicle.

The feature of the present invention is that in the driving force transmission device for the work vehicle described at the beginning, one switching valve is provided between the fluid pressure drive source and the fluid pressure actuator for the traveling fluid pressure drive mechanism and the work device. By switching the switching valve, the fluid pressure and the fluid pressure of the drive source are changed to the fluid pressure actuator for the medium-high speed traveling working device, or to the traveling fluid pressure drive mechanism and the low speed traveling working device. The flow path for supplying pressure oil from the switching valve to the fluid pressure actuator for the travel fluid pressure drive mechanism and the low speed travel work device includes a flow path for supplying pressure oil to the fluid pressure actuator. , /< As the pilot pressure increases, a first clutch interposed in the power transmission system from the traveling gear transmission to the traveling device is disengaged, and as the pilot pressure dissipates, the first clutch is engaged. A first clutch operating tool configured to engage and operate a second clutch interposed in the power transmission system of the traveling device from the traveling fluid pressure drive mechanism as the pilot pressure increases; The second clutch operation tool is connected via a pilot flow path to a second clutch operating tool configured to be operated to disengage when the clutch is deenergized, and this configuration provides the following effects.

(Function) When the switching valve is located on the medium-high speed traveling side, fluid pressure from the fluid pressure drive source is supplied to the fluid pressure actuator of the working device for medium-high speed traveling through the valve to perform work by the working device. In addition, when the switching valve is in this switching position, no fluid pressure is applied to the flow path between the switching valve and the fluid pressure drive mechanism, so the first and second pilot flows drawn from the middle of the flow path are The pilot pressure of the road is in a de-energized state, and the transmission mechanism of the traveling gear transmission to the traveling device is connected, while the transmission mechanism to the traveling device on the side of the hydraulic drive mechanism is in an off state.

Therefore, at this time, the driving force to the traveling device is transmitted through the gear transmission, and the vehicle is in a state where it can travel at medium and high speeds.

Next, when the switching valve is switched from the above position to the low speed travel side, fluid pressure from the fluid pressure drive source is supplied to the travel fluid pressure drive mechanism and the fluid pressure actuator of the low speed travel work device, and at this time, Fluid pressure is applied to the pilot flow path, and the first clutch is disengaged by actuation of the first clutch operating tool, cutting off the transmission of driving force from the traveling gear transmission to the traveling device, and the gear transmission is automatically placed in a neutral state, On the other hand, the second clutch is engaged by actuation of the second clutch operating tool, and while the vehicle is traveling at a low speed using the hydraulic pressure drive mechanism for traveling, the fluid pressure actuator can perform work on the working device for low speed traveling.

Furthermore, if you switch the valve from this valve position to the medium-high speed traveling side, the original medium-high speed traveling work device will be ready for use.
The driving force of the hydraulic drive mechanism for traveling disappears, and the neutral state of the gear transmission is automatically released.

(Effects) ■ Medium-high speed work equipment and low speed work equipment, as well as gear transmission and travel fluid pressure drive mechanism, can be switched inversely by switching only one valve, so the travel system and The switching operation of the work system has been greatly simplified, and the structure has been made much easier to operate than the conventional one.

■ The advantage is that switching between the gear transmission and the fluid pressure drive mechanism for driving is ensured because the gear transmission becomes neutral or released by supplying or stopping fluid pressure to the medium-high speed and low-speed driving sides by switching the valve. There is.

■ The operating system has the advantage of only having one valve, and the productivity of the drive power transmission system is improved.

■ Furthermore, the simplified operation has made it possible to completely eliminate erroneous operations.

Embodiments of the present invention will be described in detail below with reference to the drawings.

At the front of a vehicle body 2 equipped with a wheel-type traveling device 1, an arm 3 is configured to be movable up and down by a hydraulic cylinder 4, and a packet 5 is connected to the arm 3 by a tilt cylinder 6.
A working vehicle is constructed by providing a transporting device 7 that is configured to be swingable and scooping up and transporting dirt, etc., and a rotary snow removal device 8 driven by a fluid pressure motor M2 is attached to the rear of the machine. It is.

A traveling gear transmission 10 and a fluid pressure (travel) motor M1 are interposed in parallel between the engine E and the traveling device 1, and the engine E output is input to the gear transmission 10 via the main clutch 9. At the same time, a first clutch 11 is disposed within the transmission 10, and a travel motor M1 as a fluid pressure drive mechanism is disposed on the final output shaft 10a via a second clutch 12.

The fluid pressure from the first fluid pressure pump P1 provided at the input end 10b of the mission 100 and the second fluid pressure pump P2 provided at the other output shaft of the engine E is changed by switching the switching valve V. M1, and the fluid pressure motor M1 is stopped to supply fluid to the arm cylinder 4 and tilt cylinder 6 of the conveying device 7.
It is configured so that it can be switched between the supply state and the supply state.

First and second pilot channels 11c and 12c are drawn out from the middle of the channel C that supplies the confluent pressure oil from the switching valve V to the fluid pressure motor M1, and the first pilot channel 11c is connected to the first pilot channel 11c. The first clutch operating tool 11a is connected to a cylinder-type first clutch operating tool 11a which disconnects and operates the first clutch 11 against an internally installed return spring by pilot pressure, and the second pilot flow path 11c against the return spring attached to the second
It is connected to a cylinder-type second clutch operating tool 12a that engages and operates the clutch 12.

In a state in which fluid pressure is not supplied to the traveling motor M1 by the operation of the valve (1), the traveling device 1 as a driven device is driven via the transmission mechanism of the gear transmission 10, and in such a mechanical drive mode. In this case, the second clutch 12 is disengaged, the travel motor M1 is stopped and is in an idle state, and the fluid pressure from the first pump P1 is supplied to the tilt cylinder 6 via the operation valve V1, and the second Fluid pressure from the pump P2 is supplied to the arm cylinder 4 via the operation valve V2, and in a working state in which the conveying section 7 is used, the gear transmission 1 is
0 configures the traveling device 1 to be driven at medium and high speeds.

Next, in a state where fluid pressure is jointly supplied to the traveling motor M1 by the pulp V operation, the traveling device 1 is driven at a low speed by the fluid pressure by the motor M1.

In such a case, it is necessary to powerfully drive the fluid pressure motor M2 that drives the snow removal work device 8, which is provided on the downstream side of the travel motor M1, with high torque. By connecting the fluid pressure motor M2 for the work device 8 in series, the snow removal work device 8
When a high load occurs, the traveling speed is automatically reduced to prevent the engine from stopping without increasing the load beyond a certain level.

The traveling motor M1 is configured as a variable capacity type that can change the output with respect to the input, and its pedal 13
The vehicle is configured so that its traveling speed can be changed to a desired speed by operation, and the vehicle is configured such that pressing the pedal forward from the neutral position puts the driver in a forward traveling state, and pressing the driver backwards from the neutral position puts the vehicle in a backward traveling state. be.

In other words, the transmission of the driving force to the work system consisting of the transport device 7 and the snow removal work device 8, and the transmission of the driving force to the traveling system via the gear transmission 10 or the traveling motor M1, can only be done by operating one switching valve V. This can be done contradictoryly.

When using the transport device 7, a switching valve is positioned to supply fluid pressure to the transport device γ side, and a valve V1. Perform work by operating V2.

When driving on the road, the valves V□ and V2 are set to the neutral position.

At this time, since there is no fluid pressure supplied to the traveling motor M1 and the snow removal work device 8, the motor M1 is in a stopped state, the second clutch 12 is in a disengaged state, and the first clutch 1 is in a disengaged state.
1 remains in the entered state.

Next, the switching valve V is used to supply fluid pressure to the snow removal work device 8 side.
When the switch is operated, the fluid pressure in the pilot channels 11c and 12c from the channel C increases, and the pistons of the cylinder-shaped first and second clutch operating tools 11a and 12a resist the spring. When activated, the first clutch 11 is disengaged and the second clutch 12 is engaged, the travel motor M1 is driven and the drive system is changed from the gear transmission 10 to the travel motor M1.
Snow removal work can be performed by variable speed driving.

Also, when switching the valve V to the snow removal work device 8 side,
This is not the case when driving on the road, etc. (Since it is used only for snow removal work, the fluid pressure to the clutch 11, 12 will not fall below a certain value and unexpectedly turn on and off, and the snow removal work can be performed while maintaining low speed.) It can be carried out.

Note that the traveling device 1 may be replaced with a crawler type traveling device, and a working device such as a trencher may be used instead of the snow removal working device 8 as a high-load working device.

Here, the pump P1. P2 is a fluid pressure drive source, travel motor M1 is a travel fluid pressure drive mechanism, arm cylinder 4, tilt cylinder 6, and fluid pressure motor M2 are a fluid pressure actuator, transport device 7 is a low speed travel work device, and snow removal. The working devices 8 and the like are collectively referred to as working devices for medium and high speed travel.

[Brief explanation of the drawing]

The drawings show an embodiment of the driving force transmission device for a working vehicle according to the present invention, and FIG. 1 is an overall side view, and FIG. 2 is a drive system diagram. 1... Traveling device, 2... Vehicle body, 4, 6
2M2...Fluid pressure drive mechanism for traveling, 7...
・・Work device for medium and high speed travel, 8・・・・−・Work device for low speed travel, 10・・・Gear transmission, 11・・・・First clutch, 12・・・・・Second clutch, 11a...first clutch operating tool,
12a...Second clutch operation tool, 11c. 12c... Pilot channel, C... Channel, E... Engine, Ml... Fluid pressure drive mechanism for traveling, Pl. P2...Fluid pressure drive mechanism, ■...Switching valve.

Claims (1)

[Claims] 1 A work device 7 for medium-high speed travel and a work device 8 for low-speed travel are mounted on the vehicle body 2 equipped with the traveling device 1, and each of the work devices 7 and 8 is connected to a fluid pressure actuator 4t6t.
M2, and a traveling gear transmission 10 and a traveling fluid pressure drive mechanism M1 are interposed in parallel between the engine E and the traveling device 1 to drive the gear transmission 10 or the fluid pressure drive mechanism. In a driving force transmission device for a work vehicle configured to drive the traveling device 1 by selectively transmitting the driving force from M1,
Fluid pressure drive source P1. A switching valve V is interposed between P2 and the fluid pressure actuator 4.6 t M2 for the traveling fluid pressure drive mechanism M and the working devices 7 and 8, and by switching operation of this switching valve V. , the fluid pressure drive source P1. The fluid pressure of P2 is configured to be supplied to the fluid pressure actuators 4, 6 for the work device 7 for medium-high speed travel, or the fluid pressure actuator M2 for the fluid pressure drive mechanism M for travel, and the work device 8 for low speed travel. At the same time, a flow path C for supplying pressure oil from the switching pulp (2) to the fluid pressure drive mechanism M1 for traveling and the fluid pressure actuator M2 for the low speed traveling working device 8 is provided with a pilot pressure from the flow path C. As the vehicle ascends, the first clutch 11 interposed in the power transmission system from the traveling gear transmission 10 to the traveling device 1 is disengaged,
A first clutch operating tool 11a configured to engage and operate the first clutch 11 as the pilot pressure is deenergized; The second interposed in the power transmission system
A second clutch operating tool 12a configured to engage the clutch 12 and disengage the clutch 12 when the pilot pressure is deenergized is connected via pilot channels 11c and 12c. A driving force transmission device for work vehicles.