JPH1036079A - Device for detecting jackup of outrigger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically determine the completion of the jackup of an outrigger mounted on a construction machine such as a track crane by accurately detecting the jackup. SOLUTION: Pressure accumulators 20a to 20d are connected to the head sides of right and left suspension cylinders 16a to 16h by oil passages 21a to 21d, and opening and closing valves 23a to 23d are interposed. The rod side of each suspension cylinder 16a to 16h is connected to a tank 24 by oil passages 25a, 25b, and an opening and closing valve 26 is interposed on the side of the tank 24. Pressure switches 27, 28, 29, 30 are provided on the head sides of the plurality of suspension cylinders 16b, 16c, 16e, 16g. To jack up an outrigger during operation, first the opening and closing valves 23a to 23d and 26 are closed to block each oil passage. Under this state the jackup is started, and when the wheels leave the ground, the holding pressure of frame own weight is no longer applied to the head side of each suspension cylinder 16a to 16h, each of the pressure switches 27 to 30 is turned off, and a computer judges that the jackup is complete.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jack-up detecting device for an outrigger in a construction machine, and more particularly, to a jack-up completion state by detecting a jack-up state of an outrigger attached to a construction machine such as a truck crane. Is a device for automatically judging.

[0002]

2. Description of the Related Art Road cranes and other construction machines capable of traveling on roads are equipped with suspension cylinders between the aircraft and wheels to ensure stability during traveling and to provide a comfortable ride for the operator. ing. Further, as shown in FIG. 10, at the time of work, the outrigger 2 is pulled out from the cart 1 to increase the distance between the ground points,
A counter force is applied to the suspended load. At this time,
The truck 1 needs to be lifted by the operation of the jack cylinder 3, and the wheels 4 must be separated from the ground.

Conventionally, a pressure switch is provided on the head side of the jack cylinder 3 so that when the truck 1 floats and the wheels 4 separate from the ground, the pressure switch is turned on by the holding pressure generated on the head side, When the pressure switch is turned on, the contacts of the relay circuit are connected and a signal is input to the computer. Based on this signal, the computer determines that jacking up is completed, and the crane operation is enabled.

[0004]

The conventional jack-up detecting device for an outrigger detects the jack-up state by the holding pressure on the head side of the jack cylinder, but the small holding pressure before and after the wheel separates from the ground. Is difficult to detect. For this reason, the pressure switch may be turned on even if the wheel does not completely separate from the ground,
The computer may mistakenly recognize that the jackup is complete.

Further, when adjusting the horizontal level of the body after jacking up once, when the jack cylinder is slightly contracted, the pressure switch is turned off and the signal to the computer is cut off. For this reason, the computer determines that the tire is on-tire (the state where the wheels are in contact with the ground) due to jack-down, and the crane operation becomes impossible.

Accordingly, there arises a technical problem to be solved in order to accurately detect a jack-up state of an outrigger attached to a construction machine such as a truck crane and to automatically determine jack-up completion. An object of the present invention is to solve this problem.

[0007]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and a suspension cylinder is attached between a body and wheels to ensure stability during traveling. In a construction machine in which the outrigger is pulled out and the aircraft is lifted by the operation of the jack cylinder, the head of the suspension cylinder is attached to the aircraft and the rod is attached to the wheel, and the hydraulic pressure source and each suspension cylinder are mounted. An open / close valve is interposed in the oil passage connecting the head side of each of the suspension cylinders, while an open / close valve is interposed in the oil passage connecting the rod side of each suspension cylinder and the tank, and pressure switches are provided on the head sides of the plurality of suspension cylinders. When the vehicle is running, both of the on-off valves are opened, and the holding pressure for the weight of the aircraft is applied to the head side of the suspension cylinder. When the outrigger is jacked up during work, both of the on-off valves are closed, and when all the pressure switches detect that the wheel is separated from the ground and the holding pressure on the head side of the suspension cylinder has become zero. Another object of the present invention is to provide a jack-up detection device for an outrigger that determines that jack-up is completed.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 and 2 show a truck crane in a running posture as an example of a construction machine. A crane unit 5 is mounted on a bogie 1, and the crane unit 5 includes a revolving unit 6 and a boom attachment 7. . Also,
A suspension cylinder 16 is interposed between the body of the bogie 1 and the wheels 4, and a head portion H of the suspension cylinder 16 is mounted on the body side of the bogie 1 and a rod portion R is mounted on the wheel 4 side. It ensures stability during driving and a comfortable ride. In the running posture shown in FIG.
Each wheel 4 is in contact with the ground and is in an on-tire state.

FIG. 3 shows a hydraulic circuit of a suspension system, in which pressure oil discharged from a hydraulic pump 17 is supplied to a switching valve 18.
The gas is supplied to the circuit via the check valves 19a to 19d, and is temporarily stored in the plurality of pressure accumulators 20a to 20d. These accumulators 20a to 20d are used as hydraulic pressure sources, and
0d and the head sides of the left and right suspension cylinders 16a to 16h are connected by oil passages 21a to 21d. These oil passages 21a to 21d have throttle valves 22a to 22d with check valves, respectively.
d and the open / close valves 23a to 23d. On the other hand, the rod side of each of the suspension cylinders 16a to 16h and the tank 2
4 are connected by oil passages 25a and 25b, and an on-off valve 26 is provided on the tank 24 side.

Then, pressure switches are mounted on the head sides of the left and right suspension cylinders. Incidentally, even if the pressure switches are not attached to all of the suspension cylinders 16a to 16h, for example, the pressure switches 27 and 2 are provided on the head side of the left suspension cylinders 16b and 16c.
8 and the right suspension cylinder 16
The pressure switches 29 and 30 may be arranged on the left and right sides substantially equally so that the pressure switches 29 and 30 are provided on the head side of e and 16g.

When the truck crane is running, the on-off valve 2
3a to 23d and 26 are opened, the holding pressure corresponding to the weight of the bogie 1 is applied to the head side of the suspension cylinders 16a to 16h, and the rod side communicates with the tank 24, so that the pressure becomes zero. That is, the pressure switches 27, 28, 29, 30 are on in the on-tire mode.

FIG. 4 shows an electric circuit of the pressure switches 27 to 30. In the case of the on-tire, each of the pressure switches 27, 28, 2
Since 9 and 30 are on, the set keep relay R1A,
R2A, R3A and R4A are excited and the contacts R1 to R4 are open. Therefore, no signal is input to the computer (or the moment limiter) 31 in the on-tire mode.

FIGS. 5 to 7 show the truck crane in the working posture, in which the outrigger 2 is pulled out to the side of the bogie 1, the jack cylinder 3 is extended, and the bogie 1 is lifted so that each wheel 4 is slightly lifted from the ground. They have been separated.

When jacking up the outrigger 2 during operation, as shown in FIG. 8, first, the open / close valves 23a to 23d and 26 of the hydraulic circuit are closed to prevent the wheels 4 from lowering when the bogie 1 is floated. And each of the oil passages 21a-21
d and 25a and 25b are set to the block state.

When the jack cylinder 3 is extended in this state, the bogie 1 and the wheels 4 gradually float up substantially integrally.
When the wheel 4 separates from the ground as the trolley 1 floats, the suspension cylinder 16 lifts the wheel 4, so that each suspension cylinder 16a to 1
6h, the holding pressure corresponding to the weight of the bogie 1 is not applied to the head side, and the pressure on the head side is reduced.
7, 28, 29 and 30 are turned off.

Therefore, as shown in FIG. 9, when the pressure switches 27, 28, 29 and 30 are turned off, the reset keep relays R1B, R2B, R3B and R4B are excited and the contacts R1 and R2 are turned off.
.. R4 are connected, a signal is input to the computer 31. Based on this signal, the computer 31 determines that jacking-up is completed, and the crane operation is enabled.

When at least one of the wheels 4 is in contact with the ground, a holding pressure is applied to the pressure switch at that point.
The pressure switch does not turn off. Therefore, the contact R1
Since any one of .about.R4 is released, no signal is input to the computer 31, and the computer 31 determines that jack-up is not completed.

Thus, the present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0019]

As described above, in the present invention, among the suspension cylinders interposed between the body and the wheels, the pressure switches are provided on the head sides of a plurality of suspension cylinders, and all the pressure switches are provided. When turned off, a jack-up completion signal is input to the computer.

That is, since the jack-up reference is made when all the wheels are separated from the ground, it is possible to reliably grasp that the aircraft has lifted up, the jack-up detection accuracy becomes accurate, and the reliability and workability are improved. It can contribute to improvement.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a side view of a truck crane in a running posture state.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a hydraulic circuit diagram of a suspension system in a running posture state.

FIG. 4 is an electric circuit of a pressure switch in a running posture state.

FIG. 5 is a side view of the truck crane in a working posture state.

FIG. 6 is a view taken along line BB of FIG. 5;

FIG. 7 is a sectional view taken along line CC of FIG. 5;

FIG. 8 is a hydraulic circuit diagram of a suspension system during a jack-up operation.

FIG. 9 is an electric circuit of a pressure switch in a state where jack-up is completed.

FIG. 10 is a perspective view of a truck crane in a working posture state.

[Explanation of symbols]

 Reference Signs List 1 cart 2 outrigger 3 jack cylinder 4 wheel 16 (16a to 16h) suspension cylinder H head (of suspension cylinder) R rod (of suspension cylinder) 20a to 20d accumulator 21a to 21d oil passage 23a to 23d on-off valve 24 tank 25a, 25b Oil passage 26 On-off valve 27, 28 Pressure switch 29, 30 Pressure switch 31 Computer

Claims (1)

[Claims] 1. A construction machine in which a suspension cylinder is attached between a body and wheels to ensure stability during traveling, and an outrigger is pulled out of the body during work and the body is levitated by actuation of a jack cylinder. The head of the suspension cylinder is attached to the fuselage side, the rod is attached to the wheel side, and an opening / closing valve is interposed in the oil passage connecting the hydraulic pressure source and the head side of each suspension cylinder. An on-off valve is interposed in an oil passage connecting the rod side and the tank, and a pressure switch is provided on the head side of a plurality of suspension cylinders. When applying the holding pressure for its own weight and jacking up the outrigger at the time of work, open both open / close valves. Outrigger jack-up characterized by determining that jack-up is complete when all pressure switches detect that the suspension cylinder is closed and the wheel separates from the ground and the holding pressure on the head side of the suspension cylinder becomes zero. Detection device.