JPH0552391U - Hydraulic suspension system - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a hydraulic suspension device capable of safely releasing a suspension lock. A bypass passage having a throttle for bypassing a lock valve and a control means for controlling both circuits are provided.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a hydraulic suspension device that includes a hydraulic valve that connects an accumulator and a hydraulic cylinder with a lock valve that disconnects the accumulator and the hydraulic cylinder.

[0002]

[Prior Art]

 For a suspension device having an accumulator and a hydraulic cylinder, for example, the technique shown in FIG. 4 is shown. The outline of the suspension device for the four-axle vehicle shown in this example will be described below. In the figure, the first shaft and the second shaft on the right side are supported by the first hydraulic cylinder 1 and the second hydraulic cylinder 2, respectively, and the upper oil chambers of the hydraulic cylinders 1 and 2 are connected to the accumulator 9. It is connected by a hydraulic circuit and constitutes a spring. Similarly, the upper oil chambers of the hydraulic cylinders 3 and 4 are connected to the accumulator 10, the upper oil chambers of the hydraulic cylinders 5 and 6 are connected to the accumulator 11, and the upper oil chambers of the hydraulic cylinders 7 and 8 are It is connected to the accumulator 12 to form a mesh. The lower oil chambers of the hydraulic cylinders 1 and 2 are connected to the upper oil chambers of the hydraulic cylinders 7 and 8 on a diagonal line to complement each other, and the hydraulic cylinders 3 and 4 are similarly connected to the hydraulic cylinders 5 and 6. The spring portion of the hydraulic suspension device is configured.

Further, the hydraulic cylinders 1 to 8 and the accumulators 9 to 12 connected to the hydraulic cylinders are hydraulic power sources via the drain valves 17, 27, 37, 47 and the charge valves 18, 28, 38, 48 in parallel. It is connected to a power steering device S. Therefore, if it is necessary to increase the vehicle height, open the charge valves 18, 28, 38, 48 to receive the oil supply, and open the drain valves 17, 27, 37, 47 in the opposite case. It is configured.

Further, a lock valve 22 is provided in the middle of each accumulator and a hydraulic circuit connecting each hydraulic cylinder, and the hydraulic cylinder is locked to stop the suspension operation as necessary. Is configured.

[0005]

[Problems to be solved by the device]

 However, in the case of mobile cranes, the weight of the crane is large, so when the suspension lock device is released to return the suspension to the operating state when the lock is released, the posture changes suddenly if there is a pressure difference in the hydraulic circuit. It is dangerous.

An object of the present invention is to provide a hydraulic suspension device in which, when the lock of the hydraulic suspension is released, a sudden posture change does not occur when the lock is released even if a pressure difference occurs in the hydraulic circuit.

[0007]

[Means for Solving the Problems]

 According to the present invention, in the hydraulic suspension device including the lock valve for disconnecting the accumulator and the hydraulic cylinder in the hydraulic circuit that connects the accumulator and the hydraulic cylinder, a bypass circuit that bypasses the lock valve is provided. An electromagnetic opening / closing valve and a throttle are provided in series in the bypass circuit, and a control means having a timer for controlling the electromagnetic opening / closing valve and the lock valve is provided.

It is preferable that the control means is provided with a changeover switch for switching between a suspension locked state and a running state.

[0009]

[Explanation of effects]

 In the hydraulic suspension device configured as described above, when the changeover switch is switched from the suspension lock state to the running state, the timer opens the valve to energize the unlocking safety valve, which is an electromagnetic valve, for a specified time. Therefore, since the flow rate of the oil is restricted by the throttle and flows through the bypass circuit, the piston of the hydraulic cylinder slowly moves and the posture does not change suddenly. Also, after energizing for the specified time, the lock release safety valve closes, the lock valve releases, and the suspension becomes active.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In the drawings, corresponding members are designated by the same reference numerals, and description thereof will be omitted.

In FIG. 1, the upper oil chamber 1U of the first hydraulic cylinder 1 and the upper oil chamber 2U of the second hydraulic cylinder 2 are connected to a high pressure accumulator 14 via a lock valve 22 by a hydraulic circuit a. ing. The low pressure accumulator 15 is connected to the hydraulic circuit a via an accumulator switching valve 16. One end of the charge valve 18 and one end of the drain valve 17 are connected in parallel to the cylinder side of the lock valve 22 of the hydraulic circuit a, and the other end of the charge valve 18 is connected via the check valve 19 to the hydraulic circuit j. The other end of the drain valve 17 is connected to the hydraulic circuit k. The lock release safety valve 20 and the throttle 21 are connected in series to bypass the lock valve 22. The lower oil chambers 7L and 8L of the hydraulic cylinders 7 and 8 are connected to the hydraulic circuit a. The above valves are connected to each other, and the portion surrounded by the alternate long and short dash line indicated by the arrow U constitutes the valve unit U. 18 E, high-pressure accumulator F, low-pressure accumulator G, hydraulic cylinder upper chamber H, and hydraulic cylinder lower chamber J are provided respectively, and an accumulator switching valve M and a hydraulic pressure signal connection portion are provided. , And N for lock valve are provided. The valve unit U having the same specifications is used.

Therefore, the hydraulic cylinder 3, the hydraulic cylinder 4, the hydraulic cylinder 5, the hydraulic cylinder 6, and the hydraulic cylinder 7 and the hydraulic cylinder 8 each have a valve unit U, which is the same as the hydraulic cylinder 1 and the hydraulic cylinder 2 described above. They are linked as in the case.

The hydraulic circuit j is connected to the hydraulic pump 70 via a hydraulic switching valve 72, a filter 74 and a safety valve 75 with a flow rate control, and the hydraulic circuit k is connected to an oil reservoir 73 via a filter. . One end of the hydraulic pressure switching valve 72 is connected to a steering wheel (not shown).

The signal circuit x connected to the signal circuit M of the valve unit U has one end of the drain valve 80, the other end of which is connected to the hydraulic circuit k, the check valve 82, and the pilot switching valve 83. It is connected to the sub hydraulic pump 85. A safety valve 86 is provided on the sub pump 85.

The signal circuit y connected to the signal circuit N of the valve unit U is connected to the pilot switching valve 83 via one end of the drain valve 81 whose other end is connected to the signal circuit x and the check valve 87. It is connected to the.

The signal circuit x is provided with a hydraulic switch 88, and the signal circuit y is provided with a hydraulic switch 89.

Further, the stroke switches 90 and 91 shown in FIG. 3 indicate sensors for displaying the piston position in the hydraulic cylinder.

In the valve unit U, the lock valve 22 is provided between the upper oil chambers 5U and 6U of the hydraulic cylinders 5 and 6 and between the upper oil chambers 7U and 8U of the hydraulic cylinders 7 and 8. And a valve unit V having the same structure as the valve device composed of the unlocking safety valve 20 and the throttle 21. Further, it is connected to the signal circuit y so as to operate simultaneously with the valve unit U.

Next, FIG. 2 shows an electric circuit for controlling the lock release safety valve 20 and the lock valve 22 which are electromagnetic opening / closing valves. First, a power supply 32 and a drain valve 81 are connected by an electric circuit 1 via a changeover switch 27 and a relay 28 that switch between a suspension lock state and a running state in a driver's cab (not shown). Further, the relay 28 is connected to turn off the drain valve 81 while the timer 20 connected to the electric circuit 1 is energized to the unlocking safety valve 20.

Further, the present embodiment has a high-pressure accumulator and a low-pressure accumulator, and is configured to switch to a low-pressure accumulator having a low spring constant when, for example, the crane is removed and the truck travels. Therefore, the carriage traveling changeover switch 29 connected to the electric circuit 1 is configured to turn on and off the pilot changeover switch 83 and the drain valve 80.

Therefore, for example, when the crane section is removed and the suspension lock is released to run, if the changeover switch 27 is turned on, the timer 30 opens the lock release safety valve for a specified time (for example, 10 seconds), The pressure difference between the accumulator and the hydraulic cylinder is flow-limited by the throttle 21, and becomes the same slowly. When the specified time has elapsed, the timer 30 turns off the lock release safety valve 20, and at the same time the relay 28 turns on the drain valve 81, the signal pressure acts and the lock valve 22 opens, so the suspension lock is released safely. To be done. In this case, when the carriage traveling changeover switch 29 is turned on, the pilot changeover switch 83 and the drain valve 80 are turned on, the signal pressure acts on the accumulator changeover valve 16, and the high pressure accumulator is changed over to the low pressure accumulator.

Further, when the number of accumulators is one, the electric circuit of the changeover switch 29 becomes unnecessary.

[0024]

[Effect of the device]

 Since the present invention is configured as described above, when the lock of the hydraulic suspension is released, the lock can be safely released even if there is a pressure difference in the hydraulic circuit.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is an electric circuit diagram for controlling unlocking.

FIG. 3 is a diagram showing a stroke switch of a hydraulic cylinder.

FIG. 4 is a diagram showing an example of a conventional technique.

[Explanation of symbols]

 1-8 ... Hydraulic cylinder 14, 24, 34, 44 ... High pressure accumulator 15, 25, 35, 45 ... Low pressure accumulator 16 ... Accumulator switching valve 17, 80, 81 ... Drain valve 18・ ・ ・ Charge valve 20 ・ ・ ・ Lock release safety valve 21 ・ ・ ・ Throttle 22 ・ ・ ・ Lock valve 70, 85 ・ ・ ・ Hydraulic pump 83 ・ ・ ・ Pilot switching valve

Claims (1)

[Scope of utility model registration request] 1. A hydraulic suspension system comprising a hydraulic valve connecting an accumulator and a hydraulic cylinder with a lock valve for disconnecting the accumulator and the hydraulic cylinder, and a bypass circuit for bypassing the lock valve is provided. A hydraulic suspension device comprising: an electromagnetic opening / closing valve and a throttle in series, and a control means having a timer for controlling the electromagnetic opening / closing valve and the lock valve.