JPS6323603Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a directional valve operating device having an operating lever release device.

FIG. 1 is a diagram showing a conventional directional control valve operating device. In the figure, 1 is an operating lever, 2 is a directional control valve operated by the operating lever 1, and 3 is a plunger of the directional control valve 2. When no force is applied to the plunger 3, the directional control valve 2 is neutralized by the spring force. position, and when the directional control valve 2 is in the neutral position, the directional control valve 2 is operated by an actuator (not shown).
The pipe line connected to the pump, the pipe line connected to the discharge port of the hydraulic pump (not shown), and the pipe line connected to the tank (not shown) are cut off. 4 is a rod connecting the operating lever 1 and the plunger 3; 5 is a mechanical operating lever release device provided in the middle of the rod 4; 6 is a lever of the operating lever releasing device 5;
When the lever 6 is in the neutral position, the rod 4 is connected, and when the lever 6 is in the operating position, the rod 4 is disconnected.

In this directional valve operation device, the lever 6
When the lever is in the neutral position, the rod 4 is connected by the operating lever release device 5, so the switching amount of the directional switching valve 2 has a value corresponding to the operating amount of the operating lever 1. Further, when the lever 6 is set to the operating position, the rod 4 is separated by the operating lever release device 5, so the operating lever 1 is released, and the directional control valve 2 is released by the spring regardless of the amount of operation of the operating lever 1. The force brings it to a neutral position. Therefore, when the lever 6 is set to the operating position and the operating lever 1 is released, even if an exerciser or the like accidentally touches the operating lever 1 and operates the operating lever 1, the directional control valve 2 will remain in the neutral position. , the actuator connected to the directional control valve 2 will not operate.

FIG. 2 is a diagram showing another conventional directional control valve operating device. In the figure, 7 is a directional control valve, and 8 is a pilot pressure receiving part of the directional control valve 7. When no hydraulic pressure acts on the pressure receiving part 8, the directional control valve 7 is in the neutral position due to the spring force, and the directional control valve 7 is in the neutral position. In the position, the directional control valve 7 shuts off the line connected to the actuator, the line connected to the discharge port of the hydraulic pump, and the line connected to the tank. 9 is a hydraulic pump, 10 is an accumulator connected to the hydraulic pump 9, and 11 is a hydraulic pump 9
12 is an operating lever for the pilot valve 11, and 13 is an operating lever release valve provided between the hydraulic pump 9 and the pilot valve 11.

In this directional valve operating device, when the operating lever release valve 13 is in the A position, the hydraulic pump 9
Since this pressure oil is supplied to the pump port of the pilot valve 11, the switching amount of the directional switching valve 7 has a value corresponding to the operating amount of the operating lever 12. Furthermore, when the operating lever release valve 13 is set to the B position, the pump port of the pilot valve 11 communicates with the tank, so the operating lever 12 is released and the operating lever 12 is released.
Regardless of the amount of operation, the directional control valve 7 is brought to the neutral position by the spring force. Therefore, if the operating lever release valve 13 is set to the B position and the operating lever 12 is released, the actuator will not operate even if the operating lever 12 is erroneously operated.

However, in these directional valve operating devices, when operating the operating levers 1, 12 without releasing the operating levers 1, 12,
If the rotation of the prime mover that drives the hydraulic pumps connected to the directional control valves 2 and 7 stops due to a malfunction or other reason, pressure oil from the hydraulic pump will no longer be supplied to the actuators connected to the directional control valves 2 and 7. may operate in a direction not intended by the driver, which is extremely dangerous.

This idea was made to solve the above-mentioned problem, and when operating the control lever,
Even if the rotation of the prime mover stops due to a malfunction,
It is an object of the present invention to provide a directional switching valve operating device that can prevent an actuator from operating in a direction not intended by a driver.

To achieve this purpose, in this invention, when the operating lever is released, it is placed in a neutral position by spring force, and in the neutral position, the pipes connected to the actuator, the pipes connected to the discharge port of the hydraulic pump, and the tank are A directional switching valve operating device for operating a directional switching valve that shuts off a connected pipe line, comprising: a motor rotation detector that outputs a first release signal when the rotation of the motor that drives the hydraulic pump stops; An operating lever release device is provided that releases the operating lever when the prime mover rotation detector outputs the first release signal.

FIG. 3 is a diagram showing a directional control valve operating device according to this invention. In the figure, 14 is a hydraulic pump connected to the directional control valve 2, 15 is a prime mover that drives the hydraulic pump 14, and 16 is a prime mover rotation that detects the rotation of the prime mover 15 and outputs a release signal when the rotation of the prime mover 15 has stopped. The detector 17 is an electric operating lever release device consisting of a relay, an electromagnetic solenoid, etc. The operating lever release device 17 is normally connected to the rod 4, and when a release signal is output from the prime mover rotation detector 16, the rod is released. 4 to release the operating lever 1.

In this directional control valve operating device, when the rotation of the prime mover 15 stops due to a failure or the like while operating the operating lever 1, the operating lever 1 is automatically released and the amount of operation of the operating lever 1 is changed. Regardless, the directional control valve 2 is in the neutral position due to the spring force, and the directional control valve 2 is connected to the pipe line connected to the actuator, the pipe line connected to the discharge port of the hydraulic pump, and the pipe line connected to the tank. cut off. Therefore, when operating the operating lever 1,
Even if the rotation of the prime mover 15 stops, the actuator will not operate against the driver's intention.

FIG. 4 is a diagram showing another directional valve operating device according to this invention. In the figure, 18 is a switch provided between the prime mover rotation detector 16 and the operating lever release device 17, 19 is a release signal output device that always outputs a release signal, and 20 is a release signal output device 1.
9 and the operating lever release device 17.

In this directional control valve operating device, when the switch 18 is turned on and the switch 20 is turned off, the operating lever 1 is normally not released, and when the rotation of the prime mover 15 stops, the operating lever 1 is released. The directional control valve 2 is at the neutral position regardless of the amount of operation of the operating lever 1. Further, when the switch 20 is turned on, the operating lever 1 is always released regardless of whether the switch 18 is turned on or off and whether the prime mover 15 is rotated or stopped. In this case, even if the operating lever 1 is operated incorrectly,
Since the directional control valve 2 maintains the neutral position, the actuator connected to the directional control valve 2 does not operate. Furthermore, when the switch 18 and the switch 20 are turned off, the control lever 1 is not released even if the prime mover 15 is stopped. , the front can be lowered.

In addition, in the above-described embodiment, an electric operation lever release device 17 is used, but a mechanical or hydraulic operation lever release device may be used.

FIG. 5 is a diagram showing another directional valve operating device according to this invention. In the figure, reference numeral 21 denotes an operating lever release valve, and the operating lever release valve 21 is normally in the A position, and becomes the B position when a release signal is output from the prime mover rotation detector 16. Therefore, prime mover 1
When the rotation of the lever 5 stops, the operating lever release valve 21 becomes the B position, and the operating lever 12 is automatically released.

As explained above, in the directional control valve operating device according to this invention, when the rotation of the prime mover stops, the operating lever is automatically released. Even if the driver stops, the directional control valve is in the neutral position, so the actuator will not operate contrary to the driver's intention, and it is safe. For example, even if the rotation of the prime mover stops during a turning operation of a hydraulic excavator on a slope, the upper revolving structure will not turn against the driver's intention. For this reason, it is also possible not to provide a counterbalance valve for the swing circuit. In this way, the effects of this invention are remarkable.

[Brief explanation of drawings]

FIGS. 1 and 2 each show a conventional directional valve operating device, and FIGS. 3 to 5 each show a directional valve operating device according to this invention. 1... Operating lever, 2... Directional switching valve, 4... Rod, 7... Directional switching valve, 9... Hydraulic pump, 11... Pilot valve, 12... Operating lever, 14... Hydraulic pump, 15... Prime mover, 16... Prime mover rotation detection vessel, 1
7... Operation lever release device, 18... Switch, 19
...Release signal output device, 20...Switch, 21...Operation lever release valve.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. When the operating lever is released, it becomes a neutral position due to the spring force, and at the neutral position, the lever is connected to the pipe line connected to the actuator, the pipe line connected to the discharge port of the hydraulic pump, and the tank. A directional valve operating device for operating a directional valve that shuts off a pipe line, the directional valve operating device comprising: a prime mover rotation detector that outputs a first release signal when the rotation of the prime mover that drives the hydraulic pump stops; A directional control valve operating device comprising: an operating lever release device that releases the operating lever when a detector outputs the first release signal. 2. Practical use characterized in that the operating lever release device is one that releases the operating lever by at least one of the first release signal and the second release signal that is manually output. A directional control valve operating device according to claim 1 of the patent registration claim. 3. The directional control valve operating device according to claim 1 or 2, characterized in that a switch is provided between the prime mover rotation detector and the operating lever release device.