JPH0116180Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a lever device for a remote control box that remotely controls the boom of a truck crane.

For example, in a truck crane, most of the boom extension/retraction, raising/lowering, turning, and lifting/lowering of the hook are performed by a hydraulic actuator, and in order to operate this hydraulic actuator, a remote control box that is operated remotely in addition to the main operating device is used. It's starting to look like this.

The conventional lever device for a remote control box has a control lever that is rotatably supported almost at its center, and a U-shaped leaf spring and a coil spring are arranged between the control lever and the main body on both sides of the center of rotation. death,
The pressing forces of both are balanced and the operating lever is located at the neutral position. Then, the operating lever is rotated by pressing it in a direction against or in accordance with the leaf spring, thereby displacing the rod that is engaged with the operating lever, and actuating the hydraulic actuator in response to this change. I'm starting to do that.

However, since the operating lever is located at a neutral position with the pushing forces of the leaf springs and coil springs on both sides balanced, there is a drawback that if the pushing forces are unbalanced to some extent, the operating lever will not return to the neutral position. .

Therefore, the purpose of this invention is to prevent the above-mentioned drawbacks, and the gist of this invention is to bring the tip of the first rod into contact with one side of the operating lever, which is rotatably supported approximately at the center, and A first spring is interposed between the first rod and the main body, and the spring force applies rotational force to the operating lever, and the tip of the second rod is brought into contact with the other side, so that the second rod and the main body are connected. A second spring is interposed between the two springs, and the spring force applies a rotational force in the opposite direction to the operating lever, and the spring force of the second spring applied to the operating lever is reduced when the operating lever is in a neutral position. The position of the second rod is regulated to prevent this, and the force of the second spring at the neutral position of the operating lever is made greater than the force of the first spring.

Therefore, the operating lever is pressed by the second rod which has a strong pressing force, but since the extension of the second rod is stopped at the neutral position, the second rod acts as a stopper, and the lever is moved away from the first rod. The operating lever is maintained at the neutral position by the pressing force of the first rod, and even if the pressing force of the first spring that presses the first rod changes, in the neutral position, the first rod remains in the second position. Since the control lever is not affected by the spring, it is possible to return and maintain the control lever to the neutral position, thereby achieving the above-mentioned object.

Examples of this invention will be described below with reference to the drawings.

In FIG. 1, a remote control box is shown,
The case 1 of this box is comprised of an upper case 1a and a lower case 1b, which are fastened together with screws 2 and are brought into contact with each other at their joint surfaces.

Above the case 1, there is a power switch 3 for remote control that also serves as an emergency stop switch, a power pilot lamp 4, a buzzer switch 5 for issuing an alarm when necessary such as when starting remote control, and a hydraulic power switch (not shown). An accelerator knob 6 is provided to adjust the discharge flow rate of the pump by increasing or decreasing the engine speed.

In the center of the case 1, there is a lever device 7 as described below.
There are four units a, 7b, 7c, and 7d arranged in parallel, and from the left side in the figure, the boom is extended and contracted, the boom is moved up and down, the hook is moved up and down, and the boom is rotated.

The detailed configuration of one of the lever devices 7d is shown in FIG.
0 and 10, and the tip of the first rod 11 is in contact with the lower surface of one side of the operating lever 8, and the tip of the second rod 12 is in contact with the lower surface of the other side.

The first rod 11 and the second rod 12 are connected to upper adjusting portions 13, 14 and upper adjusting portions 13, 12, respectively.
4 are screwed into the sliding parts 15 and 16. Below the sliding parts 15 and 16, the case 1
The sliding chambers 19 and 21 are arranged in sliding chambers 19 and 21, and those portions are large diameter portions 15a and 16a with a large diameter.

In the large diameter portion 15a of the sliding portion 15 of the first rod 11, a spring storage hole 25 is formed from below to the center of the shaft, and a spring storage hole 25 is formed between the sliding portion 15 of the first rod 11 and the main body 17. A spring 20 is interposed therebetween, and the force of this spring causes the first rod 11 to apply a counterclockwise rotational force to the operating lever 8.

Also, the large diameter portion 1 of the sliding portion 16 of the second rod 12
6a, a spring storage hole 26 is formed in the center of the shaft from below, and a second spring 22 is interposed between the sliding portion 16 of the second rod 12 and the main body 18, and the spring force 2nd rod 1
2 applies a rotational force in the opposite clockwise direction to the operating lever 8.

Large diameter portion 16a of sliding portion 16 of second rod 12
When the operating lever 8 is in the neutral position as shown in FIG. 2, it abuts against the upper surface of the main body 18, and the position of the second rod 12 is regulated so that it does not move any further upward. Therefore, when the operating lever 8 is rotated clockwise as shown by the two-dot chain line in FIG. It doesn't take much.

Large diameter portion 15a of sliding portion 15 of first rod 11
is located approximately in the center of the sliding chamber 19 when the operating lever 8 is in the neutral position;
When the rod is rotated left and right, the first rod 11 is displaced in the vertical direction by the spring force of the first spring 20.

Inside the main body 17 on the first rod 11 side, there is a sliding part 1
A position sensor (not shown) that detects the position of the large diameter portion 15a of No. 5 is provided, and a control signal thereof is output from the position sensor to a drive circuit (not shown) that drives the hydraulic actuator. .

Further, the force of the second spring 22 at the neutral position of the operating lever 8 is equal to the force S ₁ of the first spring 20
The operating lever 8 is held at the neutral position by receiving a rotational force of S ₁ ,l (l is the distance from the contact point of the first rod 11 to the center of rotation). ing.

In addition, 23 and 24 in the figure are protective covers.

In the above-described configuration, the operation of the lever device 7d for rotating the boom, for example, will be explained.

First, turn on the power switch 3, press the right side of the operating lever 8 with your finger, and rotate it clockwise as shown by the two-dot chain line in FIG.
is displaced downward, and this displacement drives the hydraulic circuit to rotate the boom to the right. When the operating lever 8 is released at a predetermined position, the operating lever 8 is moved counterclockwise by the force of the first spring 20. The operating lever 18 is rotated and returned to the neutral position, and the lower surface of the left end of the operating lever 18 comes into contact with the tip of the second rod 12, so that rotation of the operating lever 18 is stopped. The pressing force of the second rod 12 (the force of the second spring) is the same as that of the first rod 11.
The pressure force of the first rod is set to be about 1.5 times larger than the force of the first spring, so the pressure force of the first rod cannot press the second rod.
A neutral position is maintained.

Furthermore, when the left side of the operating lever 8 is pressed with a finger and rotated counterclockwise as shown by the dashed line in FIG. . At this time, the force pushing the left side of the operating lever 8 is exerted by the first spring 20 in a direction to rotate the lever 8 counterclockwise from the neutral position, so the pushing force of the second rod 12, that is, the force of the second spring The force can be set to be almost the same as the force for pushing the operating lever 8 to the right. When the control lever 8 is released, the second rod 12 is rotated clockwise by the force of the second spring 22 of the control lever 8 and returned to the neutral position. Since it comes into contact with the upper part and is restricted from extending any further, no further pressing force is applied, so the operating lever 8 is reliably held in the neutral position by the force from the first rod 11 from the lower end on the right side. It is something that drips.

In addition, due to long-term use, the first rod of the first rod 11
Even if the spring 20 weakens, the second rod 12 is regulated so that it can only extend to the neutral position, so the first rod 11 is not affected by the second spring 22.
If the spring force is weak, it will surely return to the neutral position.

As described above, according to this invention, the operating lever can be reliably maintained at the neutral position.

Furthermore, since the first and second springs acting on the operating lever are both of the same type, the operating feeling is improved.

[Brief explanation of the drawing]

The figures show an embodiment of this invention, with FIG. 1 being a perspective view of a remote control device, and FIG. 2 being an enlarged sectional view of a lever device. 7a, 7b, 7c, 7d... lever device, 8...
...Operation lever, 11...First rod, 12...Second rod, 17, 18...Main body, 20...First spring, 22...Second spring.

Claims (1)

[Scope of utility model registration request] The tip of the first rod is brought into contact with one side of the operating lever, which is rotatably supported approximately at the center, and the first rod is rotated.
A first spring is interposed between the rod and the main body,
This spring force applies a rotational force to the operation lever, and the tip of the second rod is brought into contact with the other side, and a second spring is interposed between the second rod and the main body, and the spring force is applied to the operating lever. and applying a rotational force in the opposite direction to the operating lever, and regulating the position of the second rod so as to prevent the spring force of the second spring from acting on the operating lever at the neutral position of the operating lever; , the second control lever is in the neutral position.
A lever device for a remote control box, characterized in that the force of the spring is greater than the force of the first spring.