JPH0343445Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a simultaneous and individual hydraulic control circuit for a plurality of hydraulic actuators.

Conventionally, equipment equipped with a plurality of hydraulic actuators, such as freight cars, etc., have hydraulic jacks with built-in hydraulic cylinders attached to both sides of the front of the loading platform, and the loading platform is tilted by extending the hydraulic jacks. In this system, a control switching valve was installed on each of the left and right hydraulic cylinders of the jacks, and when both were to be extended or contracted at the same time, the operator had to manually operate each switching valve at the same time. is complicated, and
There was a problem in that it was difficult to simultaneously expand and contract both jacks.

In view of the problems of conventional hydraulic control circuits having a plurality of hydraulic actuators as described above, the present invention has been developed by making it possible to simultaneously control a plurality of hydraulic actuators by operating a single lever. , was made for the purpose of proposing a simultaneous and individual hydraulic control circuit for a plurality of hydraulic actuators, which enables synchronized control of a plurality of hydraulic actuators and simplifies control operations. , a plurality of hydraulic actuators, the same number of individual control switching valves as the respective hydraulic actuators for individually controlling each of the hydraulic actuators, and one simultaneous control switching valve for simultaneously controlling each of the hydraulic actuators. and a switching valve assembly connected to a hydraulic pressure supply source, wherein the switching valve for individual control and each of the hydraulic actuators are connected by a first oil pipe line and a second oil pipe line, respectively, while the switching valve assembly for simultaneous control is connected to a hydraulic pressure supply source. Each of the hydraulic actuators is connected to the switching valve via a third oil pipe connected to the first oil pipe and a fourth oil pipe connected to the second oil pipe, and further, the third oil pipe The present invention is characterized in that a first double pilot check valve and a second double pilot check valve are interposed in the oil pipe and the fourth oil pipe, respectively.

Hereinafter, the simultaneous and individual hydraulic control mechanism for a plurality of hydraulic actuators of the present invention will be explained using the hydraulic control circuit of the jacking device 3 of the crane-equipped freight vehicle Z shown in FIGS. 1 to 3 as an example. The hydraulic control circuit X of the jacking device 3 is shown.

This hydraulic control circuit X includes a pair of jacks 8, 8.
(Fig. 1) Two hydraulic actuators, a first hydraulic cylinder 5 and a second hydraulic cylinder 6, inserted in the interior, and a 6-port 3-position second hydraulic actuator for individually controlling the first hydraulic cylinder 5. 6 ports 3 for individually controlling the switching valve 12 and the second hydraulic cylinder 6
Position type third switching valve 13 and first hydraulic cylinder 5
and the second hydraulic cylinder 6 simultaneously.
The switching valve assembly A includes a switching valve 11 connected in parallel to a hydraulic pump 40 via a hydraulic pressure supply pipe 51. This second switching valve 12
is connected to the first hydraulic cylinder 5 via a first oil pipe line 70 consisting of a first oil pipe 60 and a second oil pipe 61. Further, the third switching valve 13 is connected to the second hydraulic cylinder 6 via a second oil pipe line 71 consisting of a third oil pipe 62 and a fourth oil pipe 63. The first oil pipe line 70 and the second oil pipe line 71 are provided with throttle valves 43 and 44, respectively, for adjusting the speed of descent of the vehicle, and lock the first hydraulic cylinder 5 and the second hydraulic cylinder 6 in the event of a hose breakage. Pilot check valves 45 and 46 are provided to prevent the engine from dropping suddenly.

On the other hand, a third oil pipe line 72 consisting of a fifth oil pipe 64 and a sixth oil pipe 65 and a fourth oil line 73 consisting of a seventh oil pipe 66 and an eighth oil pipe 67 are in contact with the first switching valve 11. . Also, of the third oil pipe line 72 and the fourth oil pipe line 73, the third oil pipe line 72 is connected to the first oil pipe line 70.
The fourth oil pipe line 73 is connected to the second oil pipe line 71, respectively. Therefore, the first hydraulic cylinder 5 and the second hydraulic cylinder 6 are connected to the first oil pipe line 70.
and are connected in parallel to the first switching valve 11 via the third oil pipe line 72, the second oil pipe line 71, and the fourth oil pipe line 73. Furthermore, this third oil pipe line 7
A first double pilot check valve 41 and a second double pilot check valve 42 are interposed in the second and fourth oil pipes 73, respectively. The first double pilot check valve 41 and the second double pilot check valve 42 are
The first switching valve 12 or the third switching valve 13
When controlling the hydraulic cylinder 5 or the second hydraulic cylinder 6 individually, from the first oil pipe line 70 or the second oil pipe line 71 side to the third oil pipe line 72 or the fourth oil pipe line
While blocking the flow of hydraulic oil to the oil pipe line 73 side,
When controlling the first hydraulic cylinder 5 and the second hydraulic cylinder 6 simultaneously by the first switching valve 11,
Regardless of the flow direction of the hydraulic oil, the third oil pipe line 72
This is to open the fourth oil pipe 73 and enable simultaneous control of the first hydraulic cylinder 5 and the second hydraulic cylinder 6 by the first switching valve 11. 6th oil pipe 65 and 4th
On the seventh oil pipe 66 and the eighth oil pipe 67 of the oil pipe line 73,
The other side is provided facing in a direction capable of blocking the flow from the first oil pipe line 70 side to the third oil pipe line 72 side or from the second oil pipe line 71 side to the fourth oil pipe line 73 side, and is the other side of each pair. Pilot check valves 41a, 4 are designed to take pilot pressure from the oil pipe at a position closer to the first switching valve 11 side.
1b or 42a and 42b. Note that the two pilot check valves 41 of this first double pilot check valve 41
a, 41b are the first pilot check valve 41a and the second pilot check valve 41, respectively.
Also, the two pilot check valves 42 of the second double pilot check valve 42 are referred to as b.
a, 42b as the first pilot check valve 42
a. It is called the second pilot check valve 42b. Each double pilot check valve 4
1 and 42 operate as follows. That is, when the first switching valve 11 is not operated, in other words, the first switching valve 1
1 is set at the neutral position 11a,
Since the third oil pipe line 72 and the fourth oil pipe line 73 are not in communication with the hydraulic pressure supply pipe 51, and no pressure is applied to the third oil pipe line 72 and the fourth oil pipe line 73, the first double pilot check valve The pilot check valves 41a, 41b of 41 and the pilot check valves 42a, 42b of the second double pilot check valve 42 are connected to the first oil pipe line 70,
It acts to prevent the flow of hydraulic oil from the second oil pipe line 71 side to the third oil pipe line 72 and fourth oil pipe line 73 sides. Therefore, in this state, the second switching valve 1
The first hydraulic cylinder 5 or the second hydraulic cylinder 6 can be individually controlled by the second or third switching valve 13.

On the other hand, when the first hydraulic cylinder 5 and the second hydraulic cylinder 6 are simultaneously controlled by the first switching valve 11, for example, the first switching valve 11 is moved from the neutral position 11a to the first hydraulic cylinder 6.
When switched to position 11b, hydraulic pump 40
Hydraulic oil is pumped from the first double pilot check valve 41 through the first switching valve 11.
It enters the tail portion 5a of the first hydraulic cylinder 5 and the tail portion 6a of the second hydraulic cylinder 6 through the pilot check valve 41a and the first pilot check valve 42a of the second double pilot check valve 42. The second hydraulic cylinder 6 is simultaneously extended, and the first hydraulic cylinder 6 is expanded at the same time.
The return oil discharged from the head section 5b of the hydraulic cylinder 5 and the head section 6b of the second hydraulic cylinder 6 is transferred to the second pilot check valve 41b of the first double pilot check valve 41 and the second pilot check valve 41b of the second double pilot check valve 42. Since the pilot check valves 42b are both opened by the hydraulic pressure in the fifth oil pipe 64 and the sixth oil pipe 65, the respective pilot check valves 41b, 42
b, and is recirculated to the first switching valve 11 side. Furthermore, when the first switching valve 11 is switched to the third position 11c, the flow of hydraulic oil is controlled in the same manner.

Each of the switching valves 11, 12, and 13 is connected to the oil tank 48 through a return oil pipe 52, and is connected to the unload pipe when there is no load, that is, when the hydraulic cylinders 5 and 6 are not operated. It is connected to the oil tank 48 side via a passage 53.

Next, the operation and effect when the hydraulic control circuit X individually controls the expansion and contraction of the first hydraulic cylinder 5 and the second hydraulic cylinder 6, and when both are controlled to expand and contract simultaneously will be explained.

First, a case will be explained in which the second switching valve 12 and the third switching valve 13 are individually operated to individually control expansion and contraction of the first hydraulic cylinder 5 or the second hydraulic cylinder 6. In this case, the first switching valve 11 is in the neutral position, and no pressure is applied to the third oil pipe line 72 and the fourth oil pipe line 73.
The first double pilot check valve 41 and the second double pilot check valve 42 installed on the
Both valves are closed. Therefore, in this case, the second switching valve 12 and the third switching valve 13 are individually connected to the first hydraulic cylinder 5 and the second hydraulic cylinder 6 via the first oil pipe line 70 and the second oil pipe line 71, respectively. By individually switching the first switching valve 12 or the second switching valve 13, the first hydraulic cylinder 5 or the second hydraulic cylinder 6 can be expanded or contracted as appropriate.
At this time, as in the case of a conventional hydraulic control circuit, by simultaneously switching the second switching valve 12 and the third switching valve 13, the first hydraulic cylinder 5 and the second hydraulic cylinder 6 can be controlled to expand and contract at the same time. Of course, this can be done. However, in this case, the first
It is difficult to extend and contract the hydraulic cylinder 5 and the second hydraulic cylinder 6 in complete synchronization.

Next, in the case where the first hydraulic cylinder 5 and the second hydraulic cylinder 6 are controlled to expand and contract simultaneously only by the switching operation of the first switching valve 11, the second switching valve 12 and the third hydraulic cylinder
When the switching valves 13 are both set to the neutral positions 12a and 13a (non-operated state), the first switching valve 11
is operated to switch from the neutral position 11a to the first position 11b or the second position 11c. For example, when the first switching valve 11 is switched to the first position 11b,
Oil flows from the first switching valve 11 through the fifth oil pipe 64 and the seventh oil pipe 66 to the tail portion 5 of the first hydraulic cylinder 5.
a and the tail portion 6a of the second hydraulic cylinder 6, respectively, thereby causing the first hydraulic cylinder 5 and the second hydraulic cylinder 6 to extend simultaneously. Further, the return oil discharged from the first hydraulic cylinder 5 and the second hydraulic cylinder 6 is transferred to the second pilot check valve 41b of the first double pilot check valve 41 and the second pilot check valve 42b of the second double pilot check valve 42. Since both of the valves are opened, the oil flows from the sixth oil pipe 65 and the eighth oil pipe 67 to the return oil pipe line 52 side via the first switching valve 11 and is recirculated to the oil tank 48 side. in this case,
By appropriately adjusting the throttle opening degrees of the first throttle valve 43 and the second throttle valve 44 according to the pipe resistance, etc., the first hydraulic cylinder 5 and the second hydraulic cylinder 6 are synchronously expanded and contracted. I can do it.

The switching valve assembly A for jack operation is mounted on the lower frame V of the crane main body in a stacked manner together with the switching valve assembly B for crane operation, as shown in FIG.
Each switching valve 1 of each switching valve assembly A, B
1, 12, 13, 14, 15, 16, 17 are operating levers 21, 22, 23, 24, 25, respectively.
Switching is performed by arc rotation operations 26 and 27.
In FIG. 3, reference numeral 20 denotes a remote control lever for remotely controlling the first switching valve 11 for simultaneous jack control from a position below the lower frame V of the crane main body, which is a position below the vehicle frame 1 in FIG. The lower end 30 of the intermediate link 30 has one end 30a fixed to the first switching valve rotating lever 31.
It is attached to b. In this way, if the remote control lever 20 for simultaneous jack control is provided at the lower part of the crane main body lower frame V or the vehicle frame 1, even when the pair of jacks 8 are extended,
Workers can easily perform jacking operations from the ground.

Next, to explain the effects of the present invention, according to the simultaneous and individual hydraulic control circuit for a plurality of hydraulic actuators of the present invention, a plurality of hydraulic actuators and a circuit for individually controlling each hydraulic actuator are provided. a switching valve assembly configured by connecting the same number of individual control switching valves as each hydraulic actuator and one simultaneous control switching valve for simultaneously controlling each of the hydraulic actuators to a hydraulic supply source; The control switching valve and each of the hydraulic actuators are connected by a first oil pipe line and a second oil pipe line, respectively, and each of the hydraulic actuators for the simultaneous control switching valve is connected to the first oil pipe line. A third oil pipe line is connected to the second oil pipe line via a fourth oil line connected to the second oil pipe line, and a first double pilot check valve and a second double pilot check valve are connected in the third oil line and the fourth oil pipe line, respectively. Because a valve is provided,
Multiple hydraulic actuators can be controlled simultaneously by only switching the switching valve for simultaneous control, and unlike conventional hydraulic control circuits, there is no need to control multiple switching valves simultaneously during simultaneous control. This has the effect of simplifying control operations.

Furthermore, since a plurality of hydraulic actuators can be controlled simultaneously by switching a single switching valve, there is also the practical effect that each hydraulic actuator can be easily controlled synchronously.

[Brief explanation of drawings]

Fig. 1 is an overall view of a crane-equipped truck equipped with a jacking device having a hydraulic control circuit according to an embodiment of the present invention, Fig. 2 is a hydraulic control circuit diagram of the jacking device shown in Fig. 1, and Fig. 3 is a diagram of the jacking device of Fig. 1. It is an enlarged perspective view of the part shown in the figure. 5, 6...Hydraulic actuator, 11...Switching valve for simultaneous control, 12, 13...Switching valve for individual control, 40...Hydraulic pressure supply source, 41...First double pilot check valve, 42...Second Double pilot check valve, 70...first oil pipe line,
71...Second oil pipe line, 72...Third oil pipe line, 73
...4th oil pipe, A...Switching valve assembly.

Claims (1)

[Scope of utility model registration request] A plurality of hydraulic actuators 5, 6, the same number of individual control switching valves 12, 13 as the hydraulic actuators 5, 6 for individually controlling each of the hydraulic actuators 5, 6, and each hydraulic actuator 5, and a switching valve assembly A formed by connecting one simultaneous control switching valve 11 to a hydraulic pressure supply source 40,
The individual control switching valves 12 and 13 and the respective hydraulic actuators 5 and 6 are connected to a first oil pipe line 70, respectively.
and a second oil pipe line 71, while connecting each of the hydraulic actuators 5, 6 to the simultaneous control switching valve 11 through a third oil pipe line 72 connected to the first oil pipe line 70 and the second oil pipe. The third oil pipe line 72 and the fourth oil pipe line 73 are connected to each other through a fourth oil pipe line 73 connected to the oil pipe line 71,
A simultaneous and individual hydraulic control circuit for a plurality of hydraulic actuators, characterized in that a double pilot check valve 41 and a second double pilot check valve 42 are provided.