JPH0327866Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is configured so that the aircraft is driven and stopped by driving and stopping the traveling hydraulic motor, and is also provided with a hydraulic cylinder that operates the brake for the traveling device. Regarding work vehicles, the purpose is to enable the brakes to be automatically applied to the traveling device when the vehicle is stopped, and to automatically release the brakes when the vehicle is traveling, and to provide a simple structure for this purpose. It is in.

In order to achieve the objective, the present invention provides the above-mentioned work vehicle with a mechanism for energizing the brake for the traveling device to a braking state, and as the hydraulic cylinder is supplied with pressure oil, the brake for the traveling device is braked. In addition to being a single-acting type cylinder that performs a release operation, the oil supply path for the control valve of the travel hydraulic motor and the hydraulic cylinder are directly connected by an oil path branched from the oil supply path, and the control valve is at the travel stop position. , A connecting oil passage between the pump side port and tank side port is provided.

With the above configuration, when the control valve 11 of the travel hydraulic motor 10 is operated to the travel position as shown in FIG. 4, for example, the hydraulic motor 10
Since a driving load is applied to the hydraulic cylinder 22, the pressure oil in the oil supply passage 23 passes through the oil passage 27 and is supplied to the hydraulic cylinder 22.
As a result, the brake 20 is released by the hydraulic cylinder 22, and the aircraft starts traveling.

Then, as shown in FIG. 4, when the control valve 11 is operated to the traveling stop position N, the oil supply path 2
3 is discharged through the connection oil passage 24 and the hydraulic motor 10 stops, and the pressure oil of the hydraulic cylinder 22 is also discharged from the oil passage 27 to the oil supply passage 23 and the connection oil passage 24.
is discharged through the As a result, the brake 20 is biased toward the braking side by the action of the mechanism that biases the brake 20 toward the braking side.
is operated on the braking side, and the aircraft automatically stops.

As described above, when the travel control valve is operated to the travel stop position, the brake is automatically operated to the braking side, making it possible to park safely. In this case, there is no need to perform a special operation dedicated to parking, so the operability is good.

Furthermore, by connecting the hydraulic cylinder for brake operation to the oil supply path to the control valve, and by providing the connecting oil path at the travel stop position of the control valve, a configuration in which the brake is automatically operated can be obtained. Therefore, the structure is simpler and costs can be reduced compared to installing a sensor that detects whether the vehicle is running or stopping, or a control mechanism that operates the brakes based on the sensor's detection. .

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

As shown in FIGS. 1 and 2, a steering type driving wheel 1 as an example of a traveling device, a pair of left and right caster type idle wheels 2, 2 that can swing integrally, and an engine 4 provided in a bonnet 3 Above the engine bonnet 3, there is an upright storage position where the aircraft direction handle 5 for steering the wheels 1 enters the aircraft interior in a plan view, and a pair of left and right grip portions 5.
A pair of left and right idling wheels 6a, 6b are provided at the front part of the traveling machine body section, which is swingable to a lodging use position where the wheels a, 5b extend outside the machine, and a pair of left and right forks 7a, 7b. A pair of left and right supports 8a,
A forklift device configured to be driven up and down by a hydraulic cylinder 9 is connected along the forklift 8b to form a walking forklift.

As shown in FIG. 3, a control valve 11 is capable of driving, stopping, switching between forward and reverse rotations, and switching between high and low speeds in two stages in each of the forward and reverse directions of the wheel drive motor 10, which is integrally and swingably attached to the wheel 1.
is connected to the control valve 12 of the lift cylinder 9 so that pressure oil is supplied from the hydraulic pump 13 only when the control valve 12 is in the neutral position and the lowered position, as shown in FIG. As shown in the figure, it is installed inside the handle 5. Then, the swing operation arm 11a of the motor control valve 11 is attached to the rotation support shaft 16 of one of the grip portions 5b via the push/pull rod 14 and the swing arm 15 so as to swing as the arm rotates. The control valve 11 is switched and operated by rotating the grip part 5b, and the motor 10 is driven, forward/reverse switching, gear shifting, and stopping operations are performed, and the machine is driven, gear shifting, and forward/forward switching. and a stop operation, and is configured so that the aircraft can travel only when the forks 7a and 7b are in a stopped state and a lowering operation state.

As shown in FIGS. 3 and 6, the wheel rim portion 1
The brake shoe 17 for a is connected to the rotary cam 18.
The brake 20 for the wheel 1 is configured so that the diameter can be expanded or canceled by operating the swinging operation arm 19 of the wheel 1. A spring 21 as an example of a mechanism for biasing the brake 20 into a braking state and a single-acting hydraulic cylinder 22 for brake operation are linked to the operating arm 19, and as shown in FIG. The cylinder 22 is connected to the motor control valve 1 by an oil passage 27.
1 and is connected to the oil supply path 23 connecting the pump side port and the tank side port to the travel stop position N of the motor control valve 11, and when the travel operation is performed, the hydraulic motor 10
Due to the wheel drive load being applied to the cylinder 22
When pressurized oil is supplied to the cylinder 22 and the brake 20 is released against the spring 21 and the travel stop operation is performed, the cylinder 22 is connected to the tank 25 via the oil supply path 23 and the connection oil path 24. By doing so, the spring 21 becomes operable, and the brake 20 is configured to be in a braking state due to the spring 21.

Note that the operating lever 26 shown in FIGS. 1 and 6
is for manually releasing the brake 20.

The present invention can be applied to various types of work vehicles, such as those equipped with a transport device having a dumpable loading platform or a high-altitude working device having a work platform that can be freely raised and lowered, in place of a forklift device.

[Brief explanation of the drawing]

The drawings show an embodiment of the work vehicle according to the present invention, and FIG. 1 is a side view of a walking forklift, FIG. 2 is a plan view of the walking forklift, FIG. 3 is a cross-sectional view of the wheels, and FIG. 4 is a side view of a walking forklift. 5 is a partially cutaway rear view of the motor control valve installation portion, and FIG. 6 is a side view of the brake operation structure. 1... Travel device, 10... Travel motor, 11
... Motor control valve, 20 ... Brake, 21 ... Urging mechanism, 22 ... Brake operation cylinder, 23 ... Oil supply path, 24 ... Connection oil path,
27...Oil path, N...Travel stop position.

Claims (1)

[Scope of utility model registration request] The working vehicle is configured so that the machine body is driven and stopped by driving and stopping the traveling hydraulic motor 10, and is equipped with a hydraulic cylinder 22 for operating the brake 20 for the traveling device 1, A single-acting type cylinder is provided with a mechanism 21 that biases the travel device brake 20 to a braking state, and operates to release the brake 20 as the hydraulic cylinder 22 is supplied with pressure oil.
An oil supply path 23 for the control valve 11 of the traveling hydraulic motor 10 and the hydraulic cylinder 2
2, an oil passage 27 branched from the oil supply passage 23;
directly connected to the control valve 11
A working vehicle is provided with a connecting oil passage 24 between a pump side port and a tank side port at a traveling stop position N.