JPH1036078A - 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. A pressure switch 27 is provided on the rod side of the suspension cylinder 16b. To jack up an outrigger during operation, at 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, all the load of nonsuspended weight is applied to the rod side of each suspension cylinder 16a to 16h, the pressure switch 27 is turned on, 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 mounted between the 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 power source and each suspension cylinder are mounted. An on-off valve is interposed in the oil passage connecting the head side of the suspension cylinder, while an on-off valve is interposed in the oil passage connecting the rod side of each suspension cylinder and the tank, and is mounted on the rod side of any one suspension cylinder. A pressure switch is provided, and when the vehicle is running, both the on-off valves are opened to connect the oil on the rod side of the suspension cylinder to the tank. When jacking up the outrigger at the time of work, both the on-off valves are closed, and when the wheel separates from the ground and the pressure switch detects the full load of the weight under suspension, it is determined that jacking-up is completed. Is provided.

[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, each suspension cylinder 16a-
The oil passages 25a and 25b are connected between the rod side of 16h and the tank 24.
, And an open / close valve 26 is provided on the tank 24 side. Then, a pressure switch 27 is provided on one of the suspension cylinders, for example, the rod side of the suspension cylinder 16b.

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 switch 27 is off in the on-tire mode.

FIG. 4 shows the electric circuit of the pressure switch 27. Since the pressure switch 27 is off when the tire is on, the reset keep relay R1B is excited and the contact R1 is opened. Therefore, no signal is input to the computer (or moment limiter) 28 on the tire.

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
The full load of the weight under suspension (the total weight of the parts swinging separately from the body such as wheels and axles) is applied to the rod side of 6h, and the pressure on the rod side suddenly increases and the pressure switch 2
7 turns on.

Accordingly, as shown in FIG. 9, when the pressure switch 27 is turned on, the set keep relay R1A is excited and the contact R1 is connected, so that a signal is input to the computer 28. Based on this signal, the computer 28 determines that jacking-up is completed, and the crane operation is enabled.

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.

[0018]

As described above, according to the present invention, the pressure switch is provided on the rod side of any one of the suspension cylinders interposed between the body and the wheels. Is turned on, a jack-up completion signal is input to the computer.

That is, when the wheels are separated from the ground, the jack-up is used as a reference. Therefore, it is possible to reliably grasp that the aircraft has lifted up, and the jack-up detection accuracy becomes accurate, thereby improving reliability and workability. Can contribute.

[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 26 On-off valve 27 Pressure switch 28 Computer

Claims (1)

[Claims] 1. A construction machine in which a suspension cylinder is attached between a body and wheels to secure stability during traveling, and an outrigger is pulled out of the body during work and a body is lifted by operating a jack cylinder. The suspension cylinder head is attached to the fuselage side and 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 rod side of any one of the suspension cylinders. Oil to the tank, and when opening the outrigger during work, open both open / close valves. A jack-up detection device for an outrigger, wherein the jack-up is determined to be completed when the pressure switch detects the full load of the weight under suspension when the wheel is closed and the wheel separates from the ground.