JPH07332309A - Hydraulic device - Google Patents

Abstract

PURPOSE:To enable driving control while plural pieces of load are tuned with a high accuracy by providing a pressure oil supply and discharge means driven for an arbitrary number of strokes and controlling the number of strokes in a hydraulic device used in the case of lifting up as it is and moving the same. CONSTITUTION:In the case of elevating a house by hydraulic jacks 55, 57, 59, 61, when hydraulic cylinders 23, 25, 27, 29 are put in the reduced state, oil pressure is supplied from a hydraulic pump 3 to elongate the hydraulic cylinders 23-29. Pressure coil in each cylinder 23-29 is supplied to the hydraulic jacks 55-61 through solenoid switching valves 39, 41, 43, 45 to lift up the house for a designated amount. Subsequently, when the respective hydraulic cylinders 23-29 are completely raised, the solenoid switching valve 7, 39-45 are switched to restore the respective hydraulic cylinders 23-29 to their initial states while keeping pressure oil supplied to the respective hydraulic jacks 55-61. The above operation is repeated for plural strokes to lift up the house in the horizontal state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic system used, for example, to lift and move a house as it is, and more particularly, while accurately synchronizing a plurality of loads with a simple structure. The present invention relates to a device devised so that drive control can be performed.

[0002]

2. Description of the Related Art For example, when moving a house as it is without destroying it, a hydraulic device having a plurality of hydraulic jacks is used. First, hydraulic jacks are placed at multiple points in the house. The plurality of hydraulic jacks are connected to the hydraulic pressure supply / discharge means. The hydraulic pressure supply / discharge means includes a hydraulic pump, a tank, and a plurality of flow rate control valves respectively connected to the plurality of hydraulic jacks. Then, by adjusting the openings of the plurality of flow rate control valves, the plurality of hydraulic jacks are synchronized with each other, and the house is held horizontally while being raised by a predetermined amount.

Next, for example, a plurality of rolling members are arranged under the raised house, and the house is moved horizontally to a predetermined position while rolling the plurality of rolling members. After moving the house to a predetermined position, the plurality of rolling members are removed. Then, by adjusting the openings of the plurality of flow rate control valves, the plurality of hydraulic jacks are lowered in synchronization with each other, thereby lowering the house while keeping the house horizontal.
Although the work is actually performed through more complicated steps, the series of work is summarized as described above.

[0004]

In the above configuration,
Conventionally, there have been the following methods and problems as means for realizing the tuning operation of a plurality of jacks. The first method is to connect multiple booster pistons inside the hydraulic plunger pump unit directly to individual circuits without using a flow-collecting valve to secure as many discharge tuning channels as there are booster pistons. is there. However, in this method, it is impossible to construct more channels than the number of pistons inside the pump, and in order to secure many channels, the pump unit itself must be increased in size. Also, when the pressure difference between the channels becomes large, the mechanical operation state of the motor and the plunger part deteriorates, and vibration,
Since behavior and the like occur, parts such as measuring instruments are required to have high performance, and there is a problem that total cost cannot be suppressed. In addition, this method can only synchronize the discharge amount.When performing pressure relief synchronization when the jack is descending, use a double-acting type jack, and pressurize the jack pull-side port synchronously to push the jack. The method of discharging the pressure oil of the above with a relief valve was adopted. However, in this case, a channel with a high load pressure (pressure on the push side is close to the set value of the relief valve) is relieved by a little more reverse pressure, but a channel with a low load pressure is
Unless very high reverse pressurization is performed, the pressure on the push side does not reach the set value of the relief valve, so relief is not performed, and as a result, downward synchronization becomes very difficult. From the above, in this method, the relief set pressure of the push side pressure cannot be set too high, and normally, it is common to set about 50% of the set pressure of the jack (usually a double-acting jack). This is because most of the products have a pull-side pressure-receiving area that is approximately half the push-side pressure-receiving area). That is, for example, if a load of 20t is required,
At a minimum, you will have to use a jack with an output of 40 tons or more, and the cost of the jack will increase,
Since the weight of the jack was heavy, the work could be difficult. (Jack working pressure = operating pressure × 2 × safety factor) Then, the second method is to use a flow control valve (flow control valve) capable of controlling the flow rate only with a gauge regardless of the load pressure. But this valve
Generally, it is widely used for medium and low pressure ranges, and the products of the high pressure and ultra high pressure ranges that are mainly used in jacks are very expensive, and there are many technical restrictions such as temperature control. In addition, there is a problem that control and management require many difficulties when used outdoors such as at a construction site.

The present invention has been made on the basis of such a point, and its object is to have a simple structure without using a flow control valve which is expensive and difficult to control as in the conventional case. An object of the present invention is to provide a hydraulic device that enables desired synchronization control.

[0006]

In order to achieve the above object, a hydraulic system according to the present invention comprises a double-acting hydraulic cylinder which is respectively connected to a plurality of loads and includes a cylinder and a piston rod. Pressure oil supply / discharge means for supplying / discharging oil and driving it for an arbitrary number of strokes,
By controlling the number of strokes, the amount of pressure oil supplied to and discharged from each load via each hydraulic cylinder is controlled so that a plurality of loads can be driven in synchronization. It is characterized by having done. that time,
Between the first switching means arranged between the pressure oil supply / discharge means and the plurality of hydraulic cylinders for switching the supply / discharge of the pressure oil to / from the hydraulic cylinders, and between the plurality of hydraulic cylinders and their corresponding loads. It is conceivable that a configuration is provided that includes a plurality of second switching means that are arranged in the above and switch the supply of pressure oil to the load side and the return to the pressure oil supply / discharge means side. Further, the third switching means is arranged between the second switching means and the load, and when the second switching means switches back to the pressure oil supply / discharge means side, the pressure oil from the load side is removed. It is conceivable to switch the third switching means so as to regulate the return.

[0007]

First, when pressure oil is supplied from the pressure oil supply / discharge means to the hydraulic cylinder, the piston rod of the hydraulic cylinder moves to supply the pressure oil in the cylinder to the load. At this time, the amount of pressure oil supplied to the load is determined by the volume of the cylinders. Therefore, if the volume of all hydraulic cylinders is kept constant, the same amount of pressure oil can be supplied to the load. When the piston rod is moved and partitioned, pressure oil is supplied to the hydraulic cylinder from the opposite direction by the pressure oil supply / discharge means,
Return the movable piston rod to its original position. This completes one stroke. Therefore, if the number of strokes is set to be the same for all hydraulic cylinders, the same amount of pressure oil can be supplied to all loads, and eventually all loads can be controlled in a synchronized state. . Also, when returning the pressure oil once supplied to the load side,
By controlling the number of strokes of the hydraulic cylinder by the same action, it is possible to control all loads in a synchronized state. At that time, first switching means arranged between the pressure oil supply / discharge means and the plurality of hydraulic cylinders for switching the supply / discharge of the pressure oil to / from the hydraulic cylinders, the plurality of hydraulic cylinders and their corresponding loads. And a plurality of second switching means for switching between supplying pressure oil to the load side and returning to the pressure oil supply / discharge means side. Switching means and a plurality of second
The desired tuning control can be performed by appropriately controlling the switching means. Further, the third switching means is arranged between the second switching means and the load, and when the second switching means switches back to the pressure oil supply / discharge means side, the pressure oil from the load side is changed. When the third switching means is switched so as to restrict the return of the pressure oil, the second switching means and the third switching means are provided when the pressure oil supplied to the load side is sealed.
It can be performed by both the sealing by the switching means.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention will be described below with reference to FIGS.
An example will be described. FIG. 1 is a top view showing the overall configuration of the hydraulic system according to this embodiment, and FIG. 2 is a front view of the same. First, there is a casing 1, and the casing 1 accommodates a hydraulic pump 3, a tank 5, and other various hydraulic devices and a group of pipes. Then, the connection configuration of various devices housed in the housing 1 is as shown in the hydraulic circuit diagram of FIG. The details will be sequentially described below.

First, the hydraulic pump 3 and the tank 5 described above are arranged, and an electromagnetic switching valve 7 as a first switching means is connected to the discharge side of the hydraulic pump 3. The electromagnetic switching valve 7 will be described in terms of a circuit. The switching position 7a,
7b (neutral) and 7c, and solenoids 7d and 7e and return springs 7f and 7g. A hydraulic circuit 9 is connected to the secondary side of the electromagnetic switching valve 7, and a flow control valve 11 and a check valve 13 arranged in parallel are inserted in the hydraulic circuit 9. . Four hydraulic circuits 15, 17, 19, 21 are further branched and connected to the hydraulic circuit 9.

Hydraulic cylinders 23, 25, 27 and 29 are inserted in the hydraulic circuits 15, 17, 19 and 21, respectively. The hydraulic cylinder 23 is a cylinder 23
It is a double-acting hydraulic cylinder composed of a and a piston rod 23b movably accommodated in the cylinder 23a. Also, other hydraulic cylinders 25, 2
7 and 29 have the same structure, and are indicated by reference numerals a and b in the figure. The hydraulic cylinders 23, 25, 2
Hydraulic circuits 31, 33, 35 and 37 are connected to 7 and 29. These hydraulic circuits 31, 33, 35, 37 are provided with electromagnetic switching valves 39, 41, 4 as second switching means.
3, 45 are respectively inserted.

The electromagnetic switching valve 39 will be described in terms of a circuit. It has switching positions 39a and 39b, a solenoid 39c, and a return spring 39d. Also, other electromagnetic switching valves 41, 43, 4
5 has the same configuration, and the reference numeral a,
b, c, and d are attached. The electromagnetic switching valves 39, 4
The hydraulic circuits 47, 49, 51, 53 are provided at 1, 43, 45.
Are connected to these hydraulic circuits 47, 49, 51,
53 is a load, for example, hydraulic jacks 55, 57, 5
9, 61 are respectively connected. These loads 55, 5
7, 59 and 61 are devices to be tuned.
Further, it is assumed that the hydraulic jacks 55, 57, 59, 61 raise and lower a house (not shown), for example.

Further, the electromagnetic switching valves 39, 41, 43,
Hydraulic circuits 63, 65, 67, 69 are connected to 45, and these are assembled and connected as a hydraulic circuit 71 to the electromagnetic switching valve 7 already described. In addition, the hydraulic circuits 47, 49, 51, 53 include hydraulic circuits 73, 7
5, 77, 79 are branched and connected, and these hydraulic circuits 73, 75, 77, 79 are aggregated to form a hydraulic circuit 81, which is extended to the tank 5. The hydraulic circuit 73,
Opening valves 83, 85, 87, 89 at 75, 77, 79
Has been inserted. Also, hydraulic circuits 47, 49, 51, 5
3, pressure gauges 91, 93, 95 and 97 are branched and connected, respectively. A hydraulic circuit 99 is connected to the hydraulic circuit 71 so as to bypass the electromagnetic switching valve 7, and a relief valve 101 is inserted in the hydraulic circuit 99.

The operation will be described based on the above configuration. First, a plurality (4 in this embodiment) of hydraulic jacks 5
5, 57, 59, and 61 will be used as an object for raising and lowering an object (not shown), for example, a house. First, the process of raising the object to be lifted will be described. Initially, the state is as shown in FIG. First, the electromagnetic switching valve 7 is switched to the switching position 7a. Also, the piston rod 2 of the hydraulic cylinders 23, 25, 27, 29
3a, 25a, 27a and 29a are in a lowered state as shown in the figure. Further, the electromagnetic switching valves 39, 41, 43,
Reference numeral 45 denotes switching positions 39a, 41a, 43a, 45a, respectively.
Has been switched to.

In this state, pressure oil is supplied from the hydraulic pump 3. By supplying the pressure oil, the hydraulic cylinders 23, 25, 2
7, 29 piston rods 23b, 25b, 27b, 2
9b rises, whereby the cylinder 23
The pressure oil in a, 25a, 27a, 29a is the electromagnetic switching valve 3
Hydraulic jacks 55, 5 through 9, 41, 43, 45
7, 59, 61. Thereby, the hydraulic jacks 55, 57, 59, 61 are driven by a predetermined amount to raise the house by a predetermined amount. At this time, the amount of pressure oil supplied to each hydraulic jack 55, 57, 59, 61 is
Cylinder 23 of each hydraulic cylinder 23, 25, 27, 29
It is uniformly determined by the volumes of a, 25a, 27a, and 29a, so that all hydraulic jacks 55, 57, 5
The same amount of pressure oil will be supplied to 9, 61.

Next, the hydraulic cylinders 23, 25, 27,
29 piston rods 23b, 25b, 27b, 29b
Where the cylinders 23a, 25a, 27a and 29a are vertically divided, the electromagnetic switching valve 7, the electromagnetic switching valve 39,
Switching of 41, 43, and 45 is performed. That is, as shown in FIG. 5, the electromagnetic switching valve 7 is switched to the switching position 7e, and the electromagnetic switching valves 39, 41, 43, 45 are switched to the switching positions 39b, 41b, 43b, 45b. As a result, first, the pressure oil supplied to the respective hydraulic jacks 55, 57, 59, 61 is retained as it is, and at the same time, the pressure oil from the hydraulic pump 3 is transferred to the electromagnetic switching valve 7 and the electromagnetic switching valve 3 at the same time.
Via each of the hydraulic cylinders 23, 41, 43, 45,
25, 27, 29 piston rods 23b, 25b, 2
It is supplied to the upper side of 7b and 29b. As a result, the piston rods 23b, 25b, 27b, 29b return to the state shown in FIG.

By the operation up to this point, the operation of each hydraulic cylinder 23, 25, 27, 29 for one stroke is completed. After that, by repeating the same operation for a plurality of strokes, the four hydraulic jacks 55, 57, 5
By driving 9 and 61 in a synchronized state, it is possible to raise the house, which is an object to be raised and lowered, while holding it horizontally.

Next, the operation for lowering the raised house will be described. In that case, first, the state as shown in FIG. 6 is set. First, the electromagnetic switching valve 7 is switched to the switching position 7c, and the electromagnetic switching valves 39, 41, 4
3 and 45, the switching positions 39a, 41a and 4 respectively.
It has been switched to 3a, 45a. Also, the hydraulic cylinder 2
3, 25, 27, 29 piston rods 23b, 25
b, 27b and 29b are in a raised state. In this state, the return pressure oil from the hydraulic jacks 55, 57, 59, 61 side is passed through the electromagnetic switching valves 39, 41, 43, 45 to the piston rods of the hydraulic cylinders 23, 25, 27, 29. Return to the upper side of 23b, 25b, 27b, 29b.
Thereby, the piston rods 23b, 25b,
27b and 29b are cylinders 23a, 25a, 27a,
It descends to the lower position in 29a. This is shown in FIG.

Each piston rod 23b, 25b, 27
b, 29b are cylinders 23a, 25a, 27a, 29
When lowered to the lower position in a, the electromagnetic switching valve 7 is switched to the switching position 7a and the electromagnetic switching valves 39, 41, 43, 45 are switched to the switching positions 39b, 4 as shown in FIG.
Switch to positions 1b, 43b, 45b. In this state, the pressure oil from the hydraulic pump 3 causes the hydraulic cylinders 23,
25, 27, 29 piston rods 23b, 25b, 2
7b, 29b, the piston rods 23b, 25b, 27b, 29b are raised. At that time, the piston rods 23b, 25b, 27
The pressure oil on the upper side of b and 29b returns into the tank 5.

By the operation up to this point, the hydraulic jack 5
The operation for one stroke when lowering 5, 57, 59, 61 is completed. Also in this case, the hydraulic jack 55,
As in the case of raising 57, 59, 61, each hydraulic jack 55, 57, 59, 6 by one stroke is used.
The amount of the returning pressure oil of 1 is constant, and therefore, by repeating the same operation for a plurality of strokes, the hydraulic jacks 55, 57, 59, 61 can be lowered in a synchronized state. That is, the hydraulic jacks 55, 5
The object to be moved up and down supported by 7, 59, 61, that is, the house can be lowered while keeping its level.

As described in detail above, according to this embodiment, the following effects can be obtained. First, a plurality of hydraulic jacks 55, 57, 59, 61 can be hydraulically driven while synchronizing them with high accuracy, and at that time, there is no need for an expensive flow control valve as in the conventional case. This connects the hydraulic cylinders 39, 41, 43, 45 to the respective hydraulic jacks 55, 57, 59, 61, and depending on the stroke number of these hydraulic cylinders 39, 41, 43, 45,
This is because the hydraulic jacks 55, 57, 59 and 61 are synchronized. That is, each hydraulic cylinder 3
The amount of pressure oil for one stroke of 9, 41, 43, 45 is all constant. Therefore, if control is performed to match the number of strokes, the hydraulic cylinders 39, 41,
This is because 43 and 45 will be synchronized. Therefore, even when looking at the house which is moved up and down by the hydraulic jacks 55, 57, 59 and 61, the horizontal state of the house is accurately maintained when the house is moved up and down. In other words, the house can be raised and lowered while maintaining its level.

Further, as described above, in the present embodiment, it is not necessary to use an expensive flow control valve as in the conventional case, and only the hydraulic cylinder as shown in the drawing is required. The configuration is simple, and the cost can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIG. In the case of the second embodiment, the structure of the first embodiment is slightly improved. First, the hydraulic circuits 47, 49, 51, 53 are newly provided with electromagnetic switching valves 111, 113, 115 as third switching means.
117 is inserted. The electromagnetic switching valve 111 has switching positions 111a and 111b, and a solenoid 111c and a return spring 111d. Other electromagnetic switching valves 113, 115, 1
17 also has the same configuration, and is described by adding a, b, c, and d in the drawing.

Further, a control valve 119 and a check valve 121 arranged in parallel are inserted in the hydraulic circuit 73, and another check valve 123 is arranged in parallel to the electromagnetic switching valve 111. It is connected. Other hydraulic circuits 75, 77, 79
This is also the case with the control valve 119 and the check valve 121 arranged in parallel. Further, the check valves 119 are also provided to the other electromagnetic switching valves 113, 115 and 117.
Are arranged in parallel.

The operation of the above configuration will be described.
In the first embodiment, the hydraulic jacks 55, 57,
When the pressure oil on the 59, 61 side is sealed, the electromagnetic switching valves 39, 41, 43, 45 are set to the switching positions 39b, 41b, 4 and 4.
This is done by switching to 3b and 45b. In this case, no problem will occur if the electromagnetic switching valves 39, 41, 43, 45 are switched with high accuracy and no leakage occurs at the time of switching. However, depending on the electromagnetic switching valves 39, 41, 43, 45 used, some leakage may occur at the time of switching, which causes uneven pressure oil on the hydraulic jacks 55, 57, 59, 61 side. It leaks out, and as a result, the hydraulic jacks 55, 5
Horizontal holding of a house supported by 7, 59, 61 can be impaired by a small amount.

Therefore, the structure as shown in the second embodiment is adopted, and the electromagnetic switching valve 11 already explained.
When 1, 113, 115, 117 are arranged to seal the pressure oil on the hydraulic jacks 55, 57, 59, 61 side,
The electromagnetic switching valves 111, 113, 115, 117 are
The switching positions 111a, 113a, 115a, 117a are switched. The switching position 111
Since a, 113a, 115a, 117a have a check valve structure as shown in the figure, the hydraulic jack 5 is used there.
The pressure oil on the 5, 57, 59, 61 side can be sealed. At the same time, in the electromagnetic switching valves 39, 41, 43, 45, the switching position 3 is set as described in the first embodiment.
Since it is switched to the 9a, 41a, 43a, 45a side, the pressure oil on the hydraulic jacks 55, 57, 59, 61 side can be sealed there as well. That is, the hydraulic jack 5
The pressure oil on the 5, 57, 59, 61 side is double sealed.

Therefore, the same effects as in the case of the first embodiment can be obtained and, moreover, this is performed more reliably in sealing the pressure oil on the hydraulic jacks 55, 57, 59, 61 side. I was able to do it. Therefore, the leak of the pressure oil on the side of the hydraulic jacks 55, 57, 59, 61 is surely prevented, and the hydraulic jacks 55, 57, 5
The inclination of the house supported by 9, 61 can be prevented as much as possible.

Next, a third embodiment of the present invention will be described with reference to FIGS. In the case of the third embodiment, the opening / closing valves 83, 85, 87, 89 are the same as those in the first embodiment.
In the hydraulic circuits 47, 49, 51, 53, and electromagnetic switching valves 131, 133, 135 serving as third switching means.
137 is inserted. In addition, the electromagnetic switching valve 1
31, 133, 135, 137 and electromagnetic switching valves 39, 4
Check valves 139, 141, and 1 between 1, 43, and 45, respectively.
43 and 145 are inserted. The electromagnetic switching valve 131 includes switching positions 131a and 131b, a solenoid 131c, and a return spring 13.
It is equipped with 1d. Other electromagnetic switching valves 133, 13
5, 5 and 137 also have the same configuration, and will be denoted by reference numerals a, b, c and d in the figure.

The operation will be described based on the above configuration. First, when the pressure oil is supplied to the loads 55, 57, 59, 61, it is performed in the state shown in FIG. Electromagnetic switching valve 7
Is switched to the switching position 7a, and the electromagnetic switching valve 39,
41, 43, 45 are switching positions 39b, 41b, 43
It has been switched to b and 45b. In addition, the electromagnetic switching valve 13
1, 133, 135 and 137 are switching positions 131a and 1a.
It is switched to the positions of 33a, 135a, 137a.

Next, the hydraulic cylinders 23, 25, 27, 2
After the piston rods 23b, 25b, 27b, 29b of No. 9 are fully raised, the state shown in FIG. 11 is obtained. That is, the electromagnetic switching valve 7 is switched to the switching position 7c, and the electromagnetic switching valves 39, 41, 43, 45 are switched to the switching positions 39a, 41a, 43a, 45a.
The electromagnetic switching valves 131, 133, 135, 137 are
The positions are switched to the positions of the switching positions 131a, 133a, 135a, 137a. As a result, the piston rods 23b of the hydraulic cylinders 23, 25, 27, 29,
25b, 27b, 29b will return to their original positions, thereby completing the operation of one stroke.
After that, if the number of strokes is set arbitrarily, all loads will be 5
5, 57, 59, 61 can be controlled in a synchronized state.

Next, the case where the pressure oil on the load 55, 57, 59, 61 side is returned will be described. In this case, FIG.
Make the state as shown in. That is, the electromagnetic switching valve 7 is switched to the switching position 7c, and the electromagnetic switching valves 39, 4
1, 43, 45 are switching positions 39b, 41b, 43b,
It has switched to 45b. In addition, the electromagnetic switching valve 131,
133, 135 and 137 are switching positions 131b and 133.
It has been switched to positions b, 135b, 137b. As a result, the pressure oil on the side of the hydraulic jacks 55, 57, 59, 61 is returned to the upper side of the piston rods 23b, 25b, 27b, 29b of the hydraulic cylinders 23, 25, 27, 29.

Next, the piston rods 23b, 25b, 2
When 7b and 29b descend to the lower side, the state shown in FIG. 9 is restored. This caused the piston rod 2 to descend
Raise 3b, 25b, 27b, 29b to the top. Up to this point, the operation of one stroke is completed. After that, by arbitrarily setting the number of strokes, all the hydraulic jacks 55, 57, 59, 61 can be lowered while they are all synchronized.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In the case of the fourth embodiment, it is shown as an example of the simplest configuration. First, instead of the electromagnetic switching valve 7, a manual switching valve 151 as the first switching means is arranged. Has been done. The switching valve 151 has a configuration including switching positions 151a, 151b, 151c. In addition, the hydraulic circuits 31, 33, 35, 37 are
The check valve 153 and the control valve 155 arranged in parallel are inserted. Also, the hydraulic circuits 73, 75, 77, 79
A check valve 157 and a control valve 159 arranged in parallel are inserted in the above.

In the case of this embodiment, all the operations are possible only by switching the switching valve 151. First, when supplying pressure oil to the hydraulic jacks 55, 57, 59, 61 to raise it, the switching valve 151 is switched to the switching position 151a. This allows the hydraulic cylinders 23, 25, 2 to
Pressure oil is supplied to 7, 29, and piston rods 23a, 2
5a, 27a and 29a rise. Piston rod 23
The pressure oil in a, 25a, 27a, and 29a is the check valve 153.
Is supplied to the hydraulic jacks 55, 57, 59, 61 via the.

The raised piston rods 23a, 25a,
When lowering 27a and 29a, the switching valve may be switched to the switching position 151c. As a result, the pressure oil passes through the check valve 157, and the piston rods 23a, 25a,
It is supplied to the upper side of 27a and 29a. At this time, it seems that the hydraulic pressure also flows into the hydraulic jacks 55, 57, 59, 61, but for this, the set pressure of the check valve 153 is set higher than the set pressure of the check valve 157. Therefore, the check valve 153 does not open, and therefore does not flow into the hydraulic jacks 55, 57, 59, 61. With the above operation, the operation of one stroke is completed.
If the number of strokes is set arbitrarily, all hydraulic jacks 55, 57, 59, 61 can be controlled in a synchronized state.

Next, the rising hydraulic jacks 55, 5
This is a case where 7, 59, 61 are lowered, and in this case, the switching valve 151 is switched to the switching position 151c. Then, the pressure oil on the side of the hydraulic jacks 55, 57, 59, 61 is passed through the control valve 155 to the piston rods 23b, 25b,
Return to the upper side of 27b and 29b. Further, when the piston rods 23b, 25b, 27b, 29b that have once descended are raised, the switching valve 151 is switched to the switching position 151a. This completes a one-stroke operation. After that, by setting the number of strokes arbitrarily, the hydraulic jack 5
5, 57, 59, 61 can be lowered in a synchronized state.

The present invention is not limited to the first to fourth embodiments. In short, if the hydraulic cylinders are arranged between the load and the pressure oil supply / discharge means and the strokes of the hydraulic cylinders are controlled, a plurality of loads can be controlled while being synchronized. Good.

[0037]

As described above in detail, according to the hydraulic system of the present invention, the number of strokes of the hydraulic cylinder connected to the load can be simply changed without using a complicated and expensive flow control valve as in the prior art. It became possible to control while synchronizing multiple loads simply by controlling.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention and is a top view of a hydraulic device.

FIG. 2 is a front view of a hydraulic device according to the first embodiment of the present invention.

FIG. 3 is a circuit diagram showing a hydraulic circuit of the first embodiment of the present invention.

FIG. 4 is a circuit diagram showing a hydraulic circuit according to the first embodiment of the present invention.

FIG. 5 is a circuit diagram showing a hydraulic circuit according to the first embodiment of the present invention.

FIG. 6 is a circuit diagram showing a hydraulic circuit according to the first embodiment of the present invention.

FIG. 7 is a circuit diagram showing a hydraulic circuit according to the first embodiment of the present invention.

FIG. 8 is a circuit diagram showing a hydraulic circuit according to a second embodiment of the present invention.

FIG. 9 is a circuit diagram showing a hydraulic circuit in a diagram showing a third embodiment of the present invention.

FIG. 10 is a circuit diagram showing a hydraulic circuit according to a third embodiment of the present invention.

FIG. 11 is a circuit diagram showing a hydraulic circuit in a diagram showing a third embodiment of the present invention.

FIG. 12 is a circuit diagram showing a hydraulic circuit according to a third embodiment of the present invention.

FIG. 13 is a circuit diagram showing a hydraulic circuit according to a fourth embodiment of the present invention.

[Explanation of symbols]

 3 hydraulic pump 5 tank 7 electromagnetic switching valve (first switching means) 23 hydraulic cylinder 25 hydraulic cylinder 27 hydraulic cylinder 29 hydraulic cylinder 39 electromagnetic switching valve (second switching means) 41 electromagnetic switching valve (second switching means) 43 electromagnetic switching valve (second switching means) 45 electromagnetic switching valve (second switching means) 55 hydraulic jack (load) 57 hydraulic jack (load) 59 hydraulic jack (load) 61 hydraulic jack (load) 111 electromagnetic switching Valve (third switching means) 113 Electromagnetic switching valve (third switching means) 115 Electromagnetic switching valve (third switching means) 117 Electromagnetic switching valve (third switching means)

Claims (3)

[Claims] 1. A double-acting hydraulic cylinder, each of which is connected to a plurality of loads and includes a cylinder and a piston rod, and a hydraulic oil supply for supplying / discharging hydraulic oil to / from the hydraulic cylinder to drive the hydraulic cylinder for an arbitrary number of strokes. A discharge means is provided, and by controlling the number of strokes, the amount of pressure oil supplied to and discharged from each load via each hydraulic cylinder is controlled, and a plurality of loads are synchronized. A hydraulic system characterized by being driven. 2. The hydraulic system according to claim 1, further comprising: first switching means arranged between the pressure oil supply / discharge means and the plurality of hydraulic cylinders for switching the supply / discharge of the pressure oil to / from the hydraulic cylinders. A plurality of second switching means arranged between the plurality of hydraulic cylinders and the loads corresponding to the plurality of hydraulic cylinders for switching between supplying pressure oil to the load side and returning to the pressure oil supply / discharge means side. A hydraulic system characterized in that 3. The hydraulic system according to claim 2, wherein the second
The third switching means is arranged between the switching means and the load, and when the second switching means switches back to the pressure oil supply / discharge means side, the return of the pressure oil from the load side is regulated. The hydraulic system is characterized in that the third switching means is switched as described above.