JPH09265875A - Hydraulic operating device of power breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent pressure boosting abnormality in a piston pump using a small, simple, and inexpensive structure. SOLUTION: A suction check valve 17 and a discharge check valve (first check valve) 18 are provided on the suction and discharge sides of a piston pump 1, respectively. An accumulator (pressure accumulating device) 70 and a hydraulic drive system (hydraulic drive) 80 are connected to the delivery check valve 18 via a line filter 22. Stop valves 41, 42, a relief valve 43, a pressure switch 61, and a pressure gauge 62 are provided between the line filter 22 and the accumulator 70. A line check valve (second check valve) 31 which prevents high-pressure fluid from flowing back toward the piston pump 1 is provided between the delivery check valve 18 and the line filter 22. A pressure releasing element (pressure exhausting device) 50 is provided between the line check valve 31 and the delivery check valve 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power switch operating mechanism, and more particularly to a hydraulic operating device for supplementing driving energy to a hydraulic driving device using a piston pump. .

[0002]

2. Description of the Related Art A power switch is an industrial machine that normally keeps an electric circuit closed or open while keeping it stationary and drives contacts only when necessary to open and close the electric circuit. In particular, in the case of a circuit breaker or a load switch, it is necessary to extinguish the electric arc of the electric circuit that occurs during this opening operation, and the required driving speed during operation is extremely high, so the instantaneous amount of drive energy used is extremely large. Especially, as the capacity of the power system increases,
The demand for further increase in this instantaneous power is increasing, but this demand conflicts with the demand for downsizing of equipment,
In order to satisfy these requirements, various attempts have been made on both the switch body side and the operating mechanism side thereof.

[1. Features of hydraulic drive device for electric power switch and its hydraulic pressure operating device] As an operating mechanism of the electric power switch, from the viewpoint of achieving both instantaneous force and downsizing, hydraulic pressure using an extremely high pressure of 300 atm or 600 atm is used. A hydraulic operating mechanism such as an operating mechanism is often used. The hydraulic drive device that supplies hydraulic pressure to the hydraulic operation mechanism of such a power switch has characteristics different from the hydraulic drive device that is generally used.

That is, the opening operation of the electric power switch only drives the electrical contacts by several tens of centimeters in terms of distance, but the movable part for performing this opening operation is large, and this opening operation requires: Since a high speed that completes in an extremely short time of about 1/50 second is required, an extremely large drive energy is instantaneously used. In particular, depending on the model of the power switch, several thousand joules of energy are used in this short time in order to simultaneously drive the fluid compression mechanism for extinguishing the arc generated between the contacts during the opening operation. . Therefore, the hydraulic drive device of the power switch has a relatively large operating piston and is driven at a higher pressure than a general hydraulic drive device.

[0005] Further, such an electric power switch is required to make one reciprocating operation for one tenth of a second continuously for 1 to 3 times, but thereafter, it operates for a few minutes at the shortest. There is nothing to do. Further, many switches are opened and closed several times a day, but generally, they are opened and closed only a few times a year.

Therefore, while a hydraulic operating device for supplying hydraulic pressure to the hydraulic drive device of such an electric power switch is provided with an extremely large accumulator as compared with a normal hydraulic operating device, an extremely small pump is provided. Is installed. This is because the pressure fluid accumulated in the accumulator is used for the instantaneous operation, and the pump is used to replenish after the operation.

A piston pump is generally used as the pump. This piston pump has a piston chamber formed by a piston and a cylinder, and check valves provided on the suction side and the discharge side of the piston chamber, and utilizes the volume change of the piston chamber due to the reciprocating motion of the piston. However, it is a pump of the type that sucks fluid from the suction side check valve when the volume is expanded and discharges it from the discharge side check valve when the volume is reduced.

[2. Conventional Example of Hydraulic Pressure Operating Device for Power Switch] [2-1. Configuration] FIG. 10 is a system diagram showing an example of a conventional hydraulic operating device for a power switch using the piston pump as described above. As shown in FIG. 10, the hydraulic drive system 8 from the piston pump 1 via the accumulator 70.
A series of supply lines up to 0 are formed, and the hydraulic fluid pressurized by the piston pump 1 is pressurized and accumulated by the accumulator 70 and supplied to the hydraulic drive system 80 such as the operating cylinder.

First, the piston pump 1 includes a drive shaft 11,
It includes a cam 12, a cylinder 13, a spring 14, a piston 15, and a piston chamber 16 formed by the cylinder 13 and the piston 15. In this piston pump 1, the piston 15 is urged to the left side in the drawing by the spring 14 and pressed against the cam 12, and in this state, the drive shaft 11 and the cam 12 rotate to reciprocate in the axial direction. It is like this. A suction check valve 17 and a discharge check valve 18 are provided on the suction side and the discharge side of the piston pump 1, respectively. In this case, the suction check valve 17 is connected to the suction filter 21 inserted in the oil tank 101, and the discharge check valve 18 is connected to the accumulator 70 and the hydraulic drive diameter 80 via the line filter 22.

On the other hand, stop valves 41 and 42 and a relief valve 43 are provided between the line filter 22 and the accumulator 70. Of these, the stop valve 41 is used in a normally closed state, and when it is opened, the pressure liquid in the supply line is fed to the oil tank 1.
It is configured to discharge to 02. The stop valve 42 is used in a normally open state, and is configured to shut off the supply of the pressure liquid to the accumulator 70 when closed. The relief valve 43 is closed within a preset allowable pressure range, and is configured to operate when the pressure exceeds the allowable pressure range and excessively rise to discharge the pressure liquid in the supply line to the oil tank 103. ing.

A pressure switch 61 and a pressure gauge 62 are provided between the valves 41 to 43 and the accumulator 70. Among them, the pressure switch 61 is provided to detect the pressure of the supply line and control the operation of the piston pump 1 according to the detected pressure, and the pressure gauge 62 monitors the pressure of the supply line. It is provided for visual display. In the figure, 104 is an oil tank for collecting the pressure liquid discharged from the hydraulic drive meter 80.

[2-2. Operation] The hydraulic operating device of FIG. 10 configured as described above operates as follows. First, when the drive shaft 11 of the piston pump 1 and the cam 12 rotate, the piston 15 moves to the left side in the drawing, the volume of the piston chamber 16 increases, and the pressure in the piston chamber 16 decreases. As the pressure in the piston chamber 16 decreases, the suction check valve 17 opens, and the oil tank 1 passes through the suction filter 21.
Inhale the hydraulic fluid from 01.

When the cam 12 further rotates and pushes the piston 15 to the right side in the figure, the piston 15 moves to the right side in the figure against the urging force of the spring 14, and the volume of the piston chamber 16 is reduced. The pressure in the piston chamber 16 rises. When the pressure in the piston chamber 16 becomes equal to or higher than the pressure on the side opposite to the piston chamber of the discharge check valve 18, the discharge check valve 18 is pushed open, and the pressure liquid in the piston chamber 16 is stopped by the line filter 22 and the stop filter. It is supplied to the accumulator 70 and the hydraulic drive system 80 via the valve 42. In this case, the pressure liquid discharged from the hydraulic drive meter 80 due to the operation of the hydraulic drive system 80 or a minute leak is appropriately collected by the oil tank 104.

When supplying such a pressurized liquid,
When the pressure of the hydraulic fluid in the supply line falls below the first set pressure, the pressure switch 61 operates to operate the pump 1, and conversely, when the pressure rises above the second set pressure, the pressure switch 61 operates to operate the pump. To stop. By such an operation of the pressure switch 61, the pressure of the hydraulic fluid in the supply line is substantially maintained within the pressure range between the first set pressure and the second set pressure.

On the other hand, there is a possibility that the pressure of the hydraulic fluid in the supply line may excessively rise due to some inconvenience such as a failure of the pressure switch 61. In such a case, the relief valve 43 operates and the pressure liquid in the supply line is changed to the oil tank 103.
Since it is discharged to the device, it is possible to prevent the device from being damaged due to an excessive increase in pressure. In addition, the stop valve 4 that is normally closed
It is also possible to open 1 to discharge the pressure liquid to the oil tank 102.
In addition, the pressure of the pressure liquid in such a supply line is measured by the pressure gauge 6
2 can be easily monitored.

[2-3. Supplementary Explanation] In addition, in such a hydraulic operation device, in order to regularly operate the piston pump 1, as shown in FIG. 10, a leak element 51 may be installed on the hydraulic drive system 80 side. In addition, in order to render the gas that has entered the interior of the piston chamber 16 harmless, a preliminary pressurizing pump 2 such as a gear pump may be provided between the suction check valve 17 of the piston pump 1 and the suction filter 21. is there. On the other hand, in order to effectively collect and reuse the low-pressure liquid, the oil tanks 101 to 104 and 106 may be connected by a low-pressure pipe line (not shown).

[0017]

By the way, in the piston pump 1 of the hydraulic operation device as described above, the volumes of the suction check valve 17 and the discharge check valve 18, the piston 15
For some reason, such as providing a gap for preventing collision at the moving end portion of the above, there is no choice but to provide a certain non-zero minimum volume in the piston chamber 16. The minimum volume provided in this way is called the dead volume.

The compression ratio R of the piston chamber 16 of the piston pump 1 is determined by the dead volume Vd and the volume displaced by the movement of the piston 15, that is, the stroke volume Vs.
In this case, the compression ratio R is expressed by the following equation (1).

## EQU1 ## R = Vd / (Vd + Vs) Equation (1) Generally, in a high-pressure hydraulic pump, the stroke volume Vs is designed to be small by reducing the piston diameter in order to reduce the driving force for driving the piston. However, in the case of a pump with a small discharge amount, this stroke volume Vs is as small as several cm ³ and is 1 cm.
^Since many pumps are ³ or less, the dead volume Vd inevitably increases. As a result, the compression ratio R becomes about 2 to 10.

When the compression ratio R is small as described above, a problem does not usually occur in the hydraulic pump because the volume change of the liquid is extremely small. However, if bubbles are sucked, the volume change of the gas is temporarily reduced. And the dischargeable pressure drops,
If the pressure on the side opposite to the piston chamber of the discharge check valve is high, the discharge will not be possible.

With respect to the suction of the bubbles, a pump having a large discharge amount has a large stroke volume Vs, so that it is not a big problem as long as the small bubbles are sucked. However, in a pump with a small discharge amount, since the stroke volume Vs is small with respect to the size of the bubble, it may be impossible to discharge even if a slightly large bubble is sucked.

The mixing of air bubbles in the liquid in the pump is
In addition to the direct suction as described above, there is a possibility that the dissolved gas may be generated by forming bubbles.
For example, in the piston pump 1 of FIG. 10, when there is a backflow of a few drops per hour due to the sealing property of the discharge check valve 18, the gas dissolved in the high-pressure hydraulic fluid. However, bubbles form inside the piston chamber 16. In this case, the distance between the piston 15 and the cylinder 13 is usually several μm.
Since there is such a minute gap, the hydraulic fluid oozes out from the piston chamber 16 through this gap, but the bubbles cannot pass through this gap and remain in the piston chamber 16 and accumulate to form large bubbles. Could be.

Therefore, in the piston pump 1 having a small discharge amount, the operating frequency is low, and a high pressure is constantly acting on the side opposite to the piston chamber of the discharge check valve 18, or when bubbles easily enter from the suction side. Therefore, there is a high probability that a boosting failure will occur.

As a method for preventing such a boosting failure of the piston pump 1, for example, the following method which has been conventionally adopted as a countermeasure against another phenomenon is considered. To be That is,
A small amount of pressure liquid on the high-pressure side is constantly flowed to the atmospheric pressure side (example: Fig. 1
0 leakage element 51) and a method of operating the pump frequently by lowering the pressure on the high-pressure side (Japanese Patent Laid-Open No. Hei.
176917, JP-A-3-068334)
Alternatively, a preliminary pump such as a gear pump (for example, the preliminary pressurizing pump 2 in FIG. 10) is installed on the suction side of the piston pump 1, and the pressure is higher than the atmospheric pressure in the suction stroke, for example, 5 to 5.
It is conceivable to adopt a method of detoxifying the bubble volume by setting the bubble volume to 1/5 to 1/10 by setting the pressure to about 10 atmospheres.

However, among these methods, the method of frequently operating the pump is effective as a measure against gas accumulation, but has little effect on the suction of bubbles. Moreover, while the pressurization at the time of suction is effective for both suction of bubbles and accumulation of gas, the pump becomes large and expensive, which is inconvenient for downsizing the device. There was also a problem with economics.

The present invention has been proposed in order to solve the above problems of the prior art, and its purpose is to:
The compact, simple, and inexpensive structure can reliably prevent the boosting failure of the piston pump, and by using the small, inexpensive piston pump, it is small, highly reliable, and can be manufactured at low cost. Another object of the present invention is to provide a hydraulic operating device for a power switch.

[0026]

A hydraulic operating device for a power switch according to the present invention is a check valve for preventing backflow to a piston pump between a check valve on the discharge side of a piston pump and a pressure accumulator. And a small and simple structure consisting of a pressure relief device that releases the pressure on the side opposite to the piston chamber of the discharge check valve, so that when the piston pump is started, the side opposite the check valve on the discharge side of the piston pump Since the pressure of can be made low,
It is possible to reliably prevent the boosting failure of the piston pump.

In the invention according to claim 1, a hydraulic pressure operating device for an electric power switch has a piston pump for increasing the pressure of hydraulic fluid, a first check valve provided on the discharge side of the piston pump, and a pressure increasing by the piston pump. Accumulator for pressurizing and accumulating the hydraulic fluid supplied from the first check valve, a hydraulic drive device for hydraulically driving the hydraulic fluid supplied from the accumulator, and the accumulator from the piston pump. A hydraulic fluid supply line that reaches the hydraulic drive device through a device, a pressure detection unit that detects the pressure of the hydraulic fluid in the supply line, and an exhaust pressure valve that releases the pressure of the hydraulic fluid in the supply line are provided. Then, the hydraulic operating device of the electric power switch controls the operation of the piston pump according to the pressure detected by the pressure detecting means, and operates the exhaust pressure valve when the pressure rises too much. , The pressure of the hydraulic fluid in the supply line is maintained within a preset range.

Further, the invention according to claim 1 is characterized in that, in addition to the above-mentioned configuration, the following second check valve and pressure exhaust device are provided. That is, the second check valve is provided between the first check valve and the pressure accumulator in the supply line to prevent backflow of high-pressure hydraulic fluid to the piston pump side. The pressure release device is provided between the second check valve and the piston pump to release the pressure on the side opposite to the piston chamber of the first check valve when the piston pump is started.

According to the first aspect of the invention having the above-mentioned structure, when the piston pump is started, the pressure release device releases the pressure on the side opposite to the piston chamber of the first check valve.
Can be low pressure. In this case, the pressure of the hydraulic drive device side portion of the supply line is maintained at a high pressure by the second check valve, so that this portion is not affected by the exhaust pressure device.

That is, according to the present invention, the small, simple and inexpensive structure including the second check valve and the pressure exhausting device enables
It is possible to prevent the boosting failure from occurring when the piston pump is started. Therefore, it is possible to provide a hydraulic operating device that is small in size, highly reliable in operation, and can be manufactured at low cost by using a small and inexpensive piston pump.

The invention described in claim 2 is characterized in that, in the invention described in claim 1, the exhaust pressure device is configured as follows. That is, the exhaust pressure device is a throttle element that is always open, and the throttle element is set so that the outflow amount thereof is equal to or less than the discharge amount of the piston pump in the maximum working pressure state. According to the second aspect of the present invention having the above-described structure, when the piston pump is stopped, the first check valve and the second check valve are provided by the throttle element that is always open. Since the pressure in the portion between them can be made atmospheric pressure, it is possible to prevent the boosting failure at the time of starting the piston pump. Further, even if the boosting failure occurs due to the suction of air bubbles during the operation of the piston pump, the pressure in the portion between the first check valve and the second check valve is reduced during the short time during which the piston pump does not discharge. Can be lower than the pressure of the piston chamber,
The piston pump can automatically return to the boostable state.

The invention according to claim 3 is characterized in that, in the invention according to claim 2, the throttle element is a throttle channel formed by orifice-shaped pores. According to the third aspect of the invention having the above-mentioned configuration, the flow rate can be freely set by selecting the diameter of the pores.

According to a fourth aspect of the present invention, in the second aspect of the invention, the throttle element is a throttle channel formed by a gap between a cylindrical hole and a shaft penetrating the hole. I am trying. 4. A structure having the above-mentioned structure.
According to the described invention, the flow rate can be freely set by selecting the width dimension and the length of the gap formed by the cylindrical hole and the shaft.

According to a fifth aspect of the present invention, in the second aspect of the invention, the throttle element is a throttle channel formed by a thin tube wound in a coil shape. According to the invention of the fifth aspect having the above-mentioned configuration, the flow rate can be freely set by selecting the inner diameter and the length of the thin tube. Further, since the thin tube is wound in a coil shape, the structure of the pressure exhaust device can be downsized even when the thin tube is elongated.

The invention according to claim 6 is characterized in that, in the invention according to claim 2, the diaphragm element is constructed as follows. That is, the diaphragm element includes a first member having a flat surface portion and a coil-shaped groove having a predetermined depth provided therein, and a second member having a flat surface portion having no groove, and the flat surface portions are overlapped with each other. It is a coiled throttle channel formed by combining. According to the sixth aspect of the present invention having the above-described configuration, the flow rate can be freely set by selecting the width, depth, and length of the coil-shaped groove of the first member. In this case, the length of the entire coil-shaped groove can be easily adjusted by changing the pitch of the coil-shaped groove and the number of flat plates. In addition, if you need to change the flow rate, simply replace the first member,
The design can be changed easily.

The invention according to claim 7 is characterized in that, in the invention according to claim 2, the diaphragm element is constructed as follows. That is, the throttle element has a fixing member having a discharge port and a flat surface portion, and a flat plate movably arranged on the side of the supply line. When the piston pump is in operation, the flat plate moves toward the fixed member side by the flow of hydraulic fluid to limit the outflow amount from the discharge port, and the flat plate is in a free state when the piston pump is stopped. Composed. According to the invention of the seventh aspect having the above-mentioned configuration, the flow rate of the hydraulic fluid can be used to operate the flat plate, and the flow rate can be easily and reliably reduced. Also,
Since the flow rate can be reduced by using only the fixing member having the discharge port and the flat plate, the structure of the pressure exhaust device can be simplified.

The invention described in claim 8 is characterized in that, in the invention described in claim 2, the throttle element is a needle valve. According to the invention described in claim 8 having the above-mentioned configuration, the flow rate can be freely set by a simple operation of moving the position of the needle valve. Further, since the needle valve is used, the structure of the pressure exhaust device can be simplified.

The invention according to claim 9 is characterized in that, in the invention according to claim 1, the exhaust pressure device is an electromagnetic valve. According to the invention described in claim 9 having the above-mentioned configuration, the first pressure control device is configured to electrically control the pressure exhaust device.
Since the pressure in the portion between the check valve and the second check valve can be surely reduced to a low pressure, it is possible to reliably prevent the boosting failure from occurring when the piston pump is started. Therefore, the operational reliability can be further improved. In addition, since the solenoid valve can be controlled by using the electric circuit for operating the piston pump, the operation reliability can be further improved, and it is also excellent in practical use.

A tenth aspect of the present invention is characterized in that, in the ninth aspect, the solenoid valve is always closed and is opened only for a short time only when the piston pump is started. According to the invention of claim 10 having the above-mentioned structure, the first check valve and the second check valve are opened by opening the solenoid valve immediately after the piston pump is started.
Since the pressure in the portion between the check valves can be reduced, it is possible to prevent the boosting failure at the time of starting the piston pump.

The eleventh aspect of the invention is characterized in that, in the ninth aspect of the invention, the solenoid valve is always open and is closed during the start of the piston pump. According to the invention of the eleventh aspect having the above-mentioned configuration, since the electromagnetic valve is opened while the piston pump is stopped, it is possible to prevent the boosting failure when the piston pump is started.

According to a twelfth aspect of the present invention, in the first aspect of the present invention, the exhaust pressure device is a normally open manual open valve that is manually opened. According to the invention of the twelfth aspect having the above-mentioned configuration, when the boosting failure occurs, the boosting failure can be solved by manually opening the valve. In this case, since the manual opening valve is used, the structure of the pressure exhaust device can be simplified. In the case of such a configuration, it is necessary to reliably detect the occurrence of boosting failure.

A thirteenth aspect of the invention is characterized in that, in the first aspect of the invention, the exhaust pressure device is configured as follows. That is, the pressure relief device includes a valve chamber, a valve body inserted into the valve chamber, a valve seat portion that abuts on the valve body to close the flow, a discharge port provided inside the valve seat portion, and It has a biasing means for biasing the valve element in a direction away from the valve seat portion. When the piston pump is in operation, the valve body moves to the valve seat side by the pressure difference generated by the flow resistance of the hydraulic fluid to limit the amount of outflow from the discharge port, and when the piston pump is stopped. The valve body is configured to move in a direction away from the valve seat portion by the biasing means.

According to the thirteenth aspect of the present invention having the above-mentioned structure, the flow rate of the hydraulic fluid can be used to operate the valve element to easily and reliably reduce the flow rate. In particular, since the valve element is biased in the direction away from the valve seat portion by the biasing means, the flow rate is reliably increased when the piston pump is stopped, and the first check valve and the second check valve are Since the pressure in the portion between them can be quickly and surely lowered, it is possible to reliably prevent the boosting failure from occurring at the time of starting the piston pump. Therefore, the operational reliability can be further improved.

The invention according to claim 14 is the invention according to claims 1 to 13.
In each of the above inventions, the exhaust device is characterized by being configured as follows. That is, the pressure release device has a pressure release outlet opening into the air, and this outlet is the highest between the first check valve and the second check valve in the supply line. It is arranged at a position so as to open in a direction other than the downward direction.

According to the fourteenth aspect of the invention having the above-mentioned structure, the opening of the discharge port is provided at a high position to prevent the working fluid in the supply line from being replaced with air. It is possible to prevent the dissolved rate of gas from increasing. Further, by directing the opening of the discharge port in a direction other than the downward direction, it is possible to prevent the working fluid from drying in this portion. Therefore,
The operational reliability can be further improved.

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION A plurality of embodiments of a hydraulic operating device for a power switch according to the present invention will be described below with reference to FIGS.
This will be specifically described with reference to FIG. It should be noted that the same parts as those of the conventional example shown in FIG.

[1. Basic Embodiment of Liquid Pressure Operating Device] [1-1. Configuration] FIG. 1 is a system diagram showing a basic embodiment of a hydraulic operating device for a power switch to which the invention according to claim 1 is applied, as an embodiment according to the present invention. As shown in FIG. 1, in the present embodiment,
Similar to the conventional example shown in FIG. 10, a series of supply lines from the piston pump 1 to the hydraulic drive system 80 via the accumulator 70 is formed.

The structure of the piston pump 1 is shown in FIG.
0 is the same as the conventional example shown in FIG.
A suction check valve 17 and a discharge check valve (first check valve) 18 are provided on the suction side and the discharge side, respectively. Then, the suction check valve 17 is connected to a suction filter 21 inserted in the oil tank 101, and the discharge check valve 18 is connected via a line filter 22 to an accumulator (accumulator) 70 and a hydraulic drive system (hydraulic drive device). ) 80 is connected.

In this case, in the present embodiment, a line check valve (second check valve) is provided between the discharge check valve 18 and the line filter 22 to prevent the high pressure fluid from flowing back to the piston pump 1 side. A stop valve 31 is provided, and a pressure release element (pressure release device) 50 that releases the pressure liquid is further provided between the line check valve 31 and the discharge check valve 18. The pressure release element 50 is configured to release the pressure liquid in the supply line to the oil tank 105.

Incidentally, another structure, that is, the stop valves 41, 4
2 and that the relief valve 43 and the pressure switch 61 and the pressure gauge 62 are provided are the same as those in the conventional example of FIG. Further, in the present embodiment, since the line check valve 31 and the pressure release element 50 as described above are provided,
The leakage element 51 on the hydraulic drive diameter 80 side and the pre-pressurizing pump 2 on the suction side of the piston pump 1 as shown by the broken line in FIG. 10 are not provided.

[1-2. Action and Effect] According to the present embodiment having the above-described configuration, by the pressure release element 50,
At least when the piston pump 1 is started, the pressure in the pipe line in the portion between the discharge check valve 18 and the line check valve 31 in the supply line can be reduced. Therefore, it is possible to prevent the boosting failure of the piston pump 1 from occurring.

That is, as described above, the insufficient pressure increase of the piston pump 1 cannot be increased if the pressure in the discharge check valve 18 opposite to the piston chamber 16 is higher than the pressure in the piston chamber 16 during piston pump operation. It is a phenomenon. On the other hand, according to the present embodiment, the pressure releasing element 50 can lower the pressure on the side opposite to the piston chamber 16 of the discharge check valve 18 than the pressure inside the piston chamber 16, so the piston pump 1
It is possible to prevent the boosting failure from occurring.

In this case, the line check valve 31 maintains the pressure of the portion on the hydraulic drive diameter 80 side of the supply line at a high pressure, so that this portion is not adversely affected by the installation of the pressure relief element 50. Absent.

Further, even if the discharge failure occurs during the operation of the piston pump 1, the anti-piston chamber 1 of the discharge check valve 18 is held for a short time during which the piston pump 1 is not discharging.
By configuring the pressure release element 50 so that the pressure on the 6 side can be automatically lowered, it is possible to automatically return to the pressurizable state.

As described above, according to the present embodiment, the compact, simple and inexpensive structure including the line check valve 31 and the pressure release element 50 can prevent the boosting failure from occurring at the time of starting the piston pump 1. . Therefore, using a small and cheap piston pump, small and highly reliable,
Moreover, it is possible to realize a hydraulic operation device that can be manufactured at low cost.

[2. Basic Embodiment of Pressure Releasing Element] As a basic embodiment of the pressure releasing element 50 used in the hydraulic pressure control device of FIG. 1, for example, the invention according to claim 2 is applied to constantly open the element. It is conceivable that the throttling element is set so that the outflow amount of the pressure liquid from this throttling element is equal to or less than the discharge amount of the piston pump 1.

According to the present embodiment having the above-mentioned structure, when the piston pump 1 is stopped, the pressure in the pipe line between the discharge check valve 18 and the line check valve 31 is reduced. Since the pressure can be set to the atmospheric pressure, it is possible to prevent the boosting failure at the time of starting the piston pump 1. Further, if a large bubble is sucked in while the piston pump 1 is in operation, a boosting failure may temporarily occur. Even in such a case, however, the discharge check valve 18 may be discharged within a short time during which the piston pump 1 does not discharge. Since the pressure in the pipe between the line check valve 31 and the line check valve 31 can be reduced to a pressure equal to or lower than the pressure in the piston chamber 16, the piston pump 1 can automatically return to the pressurizable state.

Therefore, according to the present embodiment, in addition to the same operational effects as the basic embodiment of the hydraulic operating device, furthermore, the boosting failure that occurs during the operation of the piston pump can be reliably eliminated. However, since it is possible to automatically return to the boostable state, the operational reliability can be further improved.

The important point in this embodiment is that
The outflow from the throttling element increases with increasing pressure,
On the contrary, the discharge amount of the piston pump 1 has a characteristic that it decreases with an increase in pressure. Actually, the outflow amount from the throttle element is set to, for example, about 10% or less of the discharge pressure when the piston pump 1 is in use, so that the efficiency of the piston pump 1 is not unnecessarily reduced.

[3. Specific Embodiment of Pressure Releasing Device] Hereinafter, a more specific embodiment of the pressure releasing element 50 used in the hydraulic operating device of FIG. 1 will be described with reference to FIGS. 2 to 9. . Here, FIGS. 2 to 7 show a plurality of more specific embodiments of the pressure-releasing element using the constantly opening throttle element as the first to sixth embodiments of the pressure-releasing element according to the present invention. Is shown. FIG. 8 shows one embodiment of a pressure release element using a solenoid valve as a seventh embodiment of the pressure release element according to the present invention, and FIG. 9 shows a pressure release element according to the present invention. As an eighth embodiment of the present invention, there is shown one embodiment of a pressure release element using a valve body that operates with a pressure difference.

[3-1. First Embodiment of Pressure Relief Element]
FIG. 2 is a sectional view showing a first embodiment of the pressure relief element according to the present invention, particularly, one embodiment of the pressure relief element to which the invention according to claim 3 is applied. As shown in FIG. 2, in the present embodiment, a low pressure pipe 203 is fastened to a part of the block 201 of the line check valve 31 via a joint 202, whereby the block 20.
The first pipe 201A communicates with the pipe 203A of the low-pressure pipe 203 through the hole 202A of the joint 202. The joint 202 is provided with a flow path 20 as a throttle element.
The pores 205 are provided on the high pressure side (block 201 side) of 2A.

That is, the conduit 201A of the block 201
And the hole 202A of the joint 202 communicates with each other through the pore 205. In addition, the pipeline 201A of the block 201
In order to prevent clogging of the pores 205, a filter 204 that covers the openings of the pores 205 is provided inside. The space between the joint 202 and the filter 204 is sealed with a seal component 206, and the joint 202 and the block 2 are
A space between 01 is sealed by a seal packing 207.
The low-pressure pipe 203 is connected to an oil tank (not shown) and is configured to guide the pressure liquid discharged from the joint 202 to the oil tank.

According to the present embodiment having the above-described structure, in addition to the same operational effect as the basic embodiment of the pressure release element, the diameter of the pore 205 of the joint 202 is appropriately adjusted. By making a selection, the flow path resistance can be set freely, and therefore the flow rate can be set freely.

As a modification of the present embodiment, the portion between the discharge check valve 18 and the line check valve 31 is installed in the oil tank as a pipe-like pipe, and the pipe-like pipe is used to apply pressure to the oil tank. A configuration that directly discharges the liquid is conceivable. With this structure, the structure is simplified, so that the diaphragm element can be formed at a lower cost. Further, from the practical point of view of inspection, it is also effective to provide an inspection window in the oil tank for confirming the outflow state of the pressure liquid from the pores 205.

[3-2. Second Embodiment of Pressure Relief Element]
FIG. 3 is a sectional view showing a second embodiment of the pressure relief element according to the present invention, in particular, one embodiment of the pressure relief element to which the invention according to claim 4 is applied. As shown in FIG. 3, in the present embodiment, the block 301 is provided with a cylindrical hole 302, and a shaft 303 penetrating the hole 302 is provided. And this hole 30
A gap is formed between the shaft 2 and the shaft 303, which serves as a throttle channel having channel resistance. Further, lids 304 and 305 are fastened to both end faces of the block 301, respectively, and thereby both end faces of the hole 302 are sealed. Further, in the vicinity of both ends of the block 301, communication holes 306 and 307 that communicate with the hole 302 are provided, respectively, and open on side surfaces of the block 301 in the same direction.

The shaft 303 is provided with a plurality of circumferential grooves 308 for equalizing the pressure balance around the shaft. A large diameter portion 309 having a diameter larger than that of other portions is provided in the vicinity of both ends of the hole 302, which is a connection portion with the communication holes 306 and 307, in order to smoothly flow in and out the pressurized liquid.
Are formed.

According to the present embodiment having the above-mentioned structure, in addition to the same operational effects as the basic embodiment of the pressure release element, the following operational effects are further obtained. First, the flow path resistance can be freely set by appropriately selecting the width dimension and the length of the gap formed between the cylindrical hole 302 and the shaft 303, and thus the flow rate can be freely set. Further, when a shaft having a simple shape without the circumferential groove 308 is inserted into the cylindrical hole 302, a difference in flow path resistance of about twice or more occurs depending on the positional relationship between the hole and the shaft.
In this embodiment, since the shaft 303 is provided with the circumferential groove 308, the flow path resistance can be changed by changing the positional relationship between the hole 302 and the shaft 303 according to the flow rate.

In other words, in the present embodiment, the pressure becomes low due to insufficient boosting of the piston pump 1,
When the flow rate is low, the hole 302 and the shaft 303 are eccentric, and as a result, the flow path resistance decreases and the flow rate increases. Also, the piston pump 1 normally rises in pressure,
When the pressure becomes high and the flow rate becomes large, the axial groove 308 provided on the shaft 303 has a uniform effect of pressure balance, and the shaft 303 is
Can be expected to be lifted up in the center of the hole 302 to increase the flow path resistance and enhance the throttling effect.

[3-3. Third Embodiment of Pressure Relief Element]
FIG. 4 is a sectional view showing a third embodiment of the pressure relief element according to the present invention, in particular, one embodiment of the pressure relief element to which the invention according to claim 5 is applied. As shown in FIG. 4, in the present embodiment, a joint 402 is fastened to a part of the block 401, whereby the conduit 401A of the block 401 and the hole 402 of the joint 402.
A is connected. The joint 402 has, as a throttle element, a high pressure side of the hole 402A (block 401).
A thin tube 405 wound in a coil shape on the side) is joined by a method such as brazing. That is, block 401
The pipe line 401A and the hole 402A of the joint 402 communicate with each other through the thin tube 405. The space between the joint 402 and the block 401 is sealed with a seal packing 407.

According to the present embodiment having the above-described structure, in addition to the same operational effect as the basic embodiment of the pressure releasing element, the inner diameter and length of the thin tube 405 are appropriately selected. By doing so, the flow path resistance can be set freely, and therefore the flow rate can be set freely. In this case, it is generally difficult to make the inner diameter of the thin tube too small due to manufacturing restrictions, and considering the economical efficiency of manufacturing thin tubes with various inner diameters, the flow rate is set by changing the length of the thin tube. It is effective to do. On the other hand, in the present embodiment, since the thin tube 405 is wound in a coil shape, even if the thin tube 405 is elongated, the thin tube 405 can be compactly arranged without expanding the arrangement space. Therefore, the structure of the pressure release element can be downsized.

As a modified example of this embodiment, for example, the low-pressure pipe as in the first embodiment described above is connected to the joint 402 as needed, and the pressure liquid is supplied to the oil tank by this low-pressure pipe. It can also be configured to lead to. Further, in the present embodiment, the thin tube 405 is connected to the joint 40.
Although it is arranged on the high pressure side of No. 2, it is also possible to provide the thin tube 405 on the low pressure side and use this thin tube 405 as a pipe for guiding the pressurized liquid to the oil tank.

[3-4. Fourth Embodiment of Pressure Relief Element]
FIG. 5 is a sectional view showing a fourth embodiment of the pressure relief element according to the present invention, in particular, one embodiment of the pressure relief element to which the invention according to claim 6 is applied. As shown in FIG. 5, in the present embodiment, a part of block (second member) 501 is provided with large-diameter hole 501D opening on the surface of block 501 and pipe line 501D connected thereto. A flat surface portion 501F is provided between the large diameter hole 501D and the conduit 501H. A joint (second member) 502 is fastened to the large-diameter hole 501D of the block 501, and the joint 502 is provided with a hole 502H that opens to face the conduit 501H of the block 501. The flat portion 50 of the block 501 is provided on the end face.
A flat surface portion 502F that faces 1F is provided.

Further, the plane portion 501 of this block 501
A flat plate (first member) 503 is inserted between F and the flat portion 502F of the joint 502. Recesses 504 are provided at the centers of the flat portions on both sides of the flat plate 503 so as to face the conduit 501H and the hole 502H, respectively. Coil-shaped grooves 505 that connect the recess 504 of the flat plate 503 and the outer peripheral surface of the flat plate 503 are provided on the outer circumferences of the recesses 504 in the flat surface portions on both sides of the flat plate 503, respectively.

Both sides of the flat plate 503 have flat portions 5 on both sides.
01F and 502F are in close contact with each other, and this close contact force is given by the fastening force of the joint 502 with respect to the block 501. Here, the joint 502 and the block 50
The space between 1 is sealed with a seal component 506. Also,
Reference numeral 507 in the drawing denotes a connecting portion of the joint 502.

While the flat plate 503 is in close contact with the flat surface portions 501F and 502F on both sides as described above, the outer peripheral surface of the flat plate 503 and the large diameter hole 501D of the block 501 are in contact with each other.
A gap 508 is formed between the outer peripheral surface and the circumferential surface. As a result, the conduit 501H of the block 501 passes through the recess 504 on the side of the block 501 of the flat plate 503, and further from the inner peripheral end position P1 to the intermediate position P2 of the coil-shaped groove 505 on the same side.
Through P6 to the outer peripheral end position P7, and communicates with the gap 508. Further, the gap 508 passes through the flow path from the outer peripheral end position Q1 of the coil-shaped groove 505 on the joint 502 side of the flat plate 503 to the inner peripheral end position Q7 through the intermediate positions Q2 to Q6, and further, the recess 504 on the same side. Through the hole 502H of the joint 502. That is, the conduit 501H of the block 501 and the hole 502H of the joint 502 communicate with each other through the recess 504, the coil-shaped groove 505, and the gap 508.

According to the present embodiment having the above-described structure, in addition to the same operational effect as the basic embodiment of the pressure release element, the coil-shaped groove 50 of the flat plate 503 is further added.
By appropriately selecting the width, depth, and length of 5,
The flow path resistance can be set freely, and therefore the flow rate can be set freely. In this case, the pipeline 501H of the block 501
The length of the entire coil-shaped groove 505 interposed between the joint 502 and the hole 502H of the joint 502 can be easily adjusted by changing the pitch of the coil-shaped groove 505 and the number of the flat plates 503.

As a modified example of this embodiment, for example, the low-pressure pipe as in the above-described first embodiment is connected to the connecting portion 507 of the joint 502 as needed, and this low-pressure pipe is used. It can also be configured to guide the pressure liquid to the oil tank.

[3-5. Fifth Embodiment of Pressure Relief Element]
FIG. 6 shows a fifth embodiment of the pressure-release element according to the present invention, in particular, one of the pressure-release elements configured to change the throttle according to the flow of the pressure liquid by applying the invention of claim 7. It is sectional drawing which shows embodiment. As shown in FIG. 6, in the present embodiment, a part of the block 601 has a large-diameter hole 601 opening on the surface of the block 601.
A and a conduit 601H connected to this are provided. A joint (fixing member) 602 is fastened to the large-diameter hole 601A of the block 601, and the joint 602 is provided with a hole 602H that opens to face the conduit 601H of the block 601 and its end surface. Is provided with a flat surface portion 602F.

Further, the large diameter hole 601 of this block 601.
A flat plate 603 having substantially the same size as the flat surface portion 602F of the joint 602 is movably arranged in A so as to cover the hole 602H of the flat surface portion 602F. And this flat plate 60
3 and the flat portion 602F of the joint 602, a gap 60
5 are formed. As a result, the conduit 601H of the block 601 passes through the large-diameter hole 601A, and further, the flat plate 60.
605 between the No. 3 and the flat surface portion 602F of the joint 602
Through the hole 602H of the joint 602.
A seal component 606 seals between the joint 602 and the block 601.
The inside of 1A is kept sealed.

In the present embodiment having the above structure, the width of the gap 605 between the flat plate 603 and the flat portion 602F of the joint 602 varies depending on the position of the flat plate 603. In this case, when the piston pump 1 is stopped, the supply of the pressure liquid is stopped, so that the fluid pressure of the surrounding working fluid is evenly applied to the flat plate 603, and the flat plate 603 is in a movable state. Then, from this state, when the piston pump 1 is activated and the pressure liquid flows, the flat plate 603 is pressed toward the flat surface portion 602F by the flow of the pressure liquid from the pipe line 601H, and the gap 605 is narrowed and the flow rate is reduced. .

Therefore, according to this embodiment, the flat plate 603 can be operated by utilizing the flow of the pressure liquid, and the flow rate can be throttled easily and surely. Also, a hole (discharge port) 602
Since only the joint 602 having H and the flat plate 603 are used, the structure of the pressure release element can be simplified.

[3-6. Sixth Embodiment of Pressure Relief Element]
FIG. 7 is a sectional view showing a sixth embodiment of the pressure relief element according to the present invention, in particular, one embodiment of the pressure relief element using a needle valve to which the invention according to claim 8 is applied. is there. As shown in FIG. 7, in the present embodiment,
The block 701 is provided with a main conduit 701M that connects the piston pump 1 and the line check valve 31, a needle hole 701H branched from the main conduit 701M, and a valve chamber 701A connected to the needle hole 701H. The valve chamber 701A has an opening on the surface of the block 701,
From this opening side, a valve rod (valve body) 702 is inserted and attached to the valve chamber 701A.

In this case, the valve rod 702 has a block 701.
Is attached to the block 701 by a screw portion 701S provided on the wall surface of the valve chamber 701A and a screw portion 702S provided on the outer peripheral surface of the valve rod 702. And
The valve rod 702 is arranged so as to be movable in the axial direction by rotation of a knob 702L provided at one end protruding outward. A conical portion 702N is provided on the other end of the valve rod 702, and the conical portion 702N is inserted into the needle hole 701H.

The space between the valve rod 702 and the wall surface of the valve chamber 701A is sealed by a seal component 706, whereby the inside of the valve chamber 701A is kept in a sealed state. Further, the outlet 70 connected to this sealed portion of the valve chamber 701A.
1E is provided, and the discharge port 701E is connected to an oil tank (not shown).

In the present embodiment having the above-mentioned structure, the position of the valve rod 702 can be easily adjusted by a simple operation of rotating the knob 702L. Then, with such a simple operation, the valve rod 70
The flow path resistance can be freely set by adjusting the gap between the second conical portion 702N and the needle hole 701H.
The flow rate can be set freely. Further, since the needle valve is used, the structure of the pressure release element can be simplified.

[3-7. Seventh and Eighth Embodiments of Pressure Releasing Element] FIG. 8 is a seventh and eighth embodiment of the pressure releasing element according to the present invention, in which the inventions according to claims 9 to 11 are applied. FIG. 3 is a cross-sectional view showing two embodiments of a pressure release element using a solenoid valve. That is, (A) of FIG.
The invention according to claim 10 is applied as an embodiment of
The valve is configured so that it is always closed and the valve is opened only when it is excited. In FIG. 8B, the invention according to claim 11 is applied as an eighth embodiment, Is open, and the valve is closed only when excited.

As shown in FIG. 8, the solenoid valve body 801 is provided with a valve chamber 801A, a valve seat 801B, a valve stem chamber 801C, and a discharge port 801D. Among these, a valve 802 is provided in the valve chamber 801A, and a spring retainer 803 and a spring 804 are provided.
Is urged by the spring 804 in a direction in which it closely contacts the valve seat 801B and closes.

A valve rod 805 is provided in the valve rod chamber 801C, and a pressing portion 805A for pushing and opening the valve 802 is provided at one end of the valve rod 805. The valve rod 805 is slidably attached to the valve rod chamber 801C via a seal component 806 provided between the valve rod chamber 801C and the valve rod chamber 801C, and the end portion on the opposite side to the pressing portion 805A is Movable piece 805 of electromagnet 807 provided around it
B.

The electromagnet 807 is provided with a coil 807A arranged so as to surround the movable piece 805B, a lid 807B for axially supporting the valve rod 805, and a spring 807C for biasing the valve rod 805. . This electromagnet 807
When the coil 807A is energized and excited, a magnetic flux is generated as shown by the arrow and is adsorbed in the gap 800D2 portion between the coil 807A and the movable piece 805B in the axial direction. Gap 800 with 805B
D1 cuts off the residual magnetic flux and returns to the original state by the force of the spring 807C. Here, in the seventh embodiment shown in FIG. 8A, it is necessary to open the valve when energized and excited. In contrast, the eighth embodiment shown in FIG. Since the valve needs to be closed when energized and energized, the pressing direction of the spring 807C and the suction direction of the gap 800D2 are reversed.

The solenoid valve of the seventh embodiment shown in FIG. 8 (A) is configured to be energized momentarily by the driving circuit of the pump motor (not shown), for example, when the pump motor is energized. ing. In this case, it is possible to use the time delay relay, or to use the relay by knowing the starting current of the electric motor and the load current. The solenoid valve according to the eighth embodiment shown in FIG. 8B is configured to be energized by, for example, a pump motor operating circuit (not shown) when the pump motor is energized.

The operations of the seventh and eighth embodiments having the above-mentioned configurations are as follows. First, in the seventh embodiment (A), which is used in the normally closed state, the solenoid valve is opened immediately after the piston pump 1 is started, and the boosting failure can be prevented. When air bubbles are sucked in during the operation of the piston pump 1, it is necessary to stop and restart the piston pump 1. Therefore, it is effective to provide the pump operation circuit with a timer circuit that temporarily stops and restarts the pump when the piston pump 1 is operated for a certain period of time.

Next, in the eighth embodiment (B), which is used in the normally open state, the solenoid valve is opened while the piston pump 1 is stopped, so that when the piston pump 1 is started. 1, the pipe line between the discharge check valve 18 and the line check valve 31 is at atmospheric pressure, and the boosting failure at the moment of start-up can be avoided, but again, the boosting failure during pump operation cannot be dealt with. Therefore, also in this case, the pump operating circuit
It is effective to provide a timer circuit that temporarily stops and restarts the pump when the piston pump 1 is operated for a certain period of time.

As described above, according to the seventh and eighth embodiments, in particular, by electrically controlling the solenoid valve using the pump operating circuit, the discharge check valve 18 shown in FIG. Since the pressure in the line between the line check valves 31 can be reliably lowered, it is possible to reliably prevent the boosting failure from occurring when the piston pump 1 is started. Therefore, the operation reliability can be further improved and it is excellent in practical use.

As a modified example of this embodiment, it is effective to apply the invention described in claim 12 and simply provide a manual valve as the pressure release element 50 of FIG. In the configuration using the manual valve as described above, when the boosting failure occurs, the worker visits and manually opens the valve to eliminate the boosting failure. Then, it may be closed again to confirm that the boosting failure has been recovered. When the manual valve is used in this manner, the configuration of the entire hydraulic pressure control device can be simplified.

Further, when the manual valve is used as described above, it is extremely important to surely detect the occurrence of the boosting failure. The occurrence of the boosting failure can be easily and reliably detected by, for example, monitoring the operating time of the piston pump and issuing a warning when an abnormality occurs.

[3-8. Ninth Embodiment of Pressure Relief Element]
FIG. 9 shows a ninth embodiment of the pressure-release element according to the present invention, in particular, one of the pressure-release elements configured to change the throttle according to the flow of the pressure liquid by applying the invention of claim 13. It is sectional drawing which shows embodiment. In this embodiment,
It is similar to the fifth embodiment in that the throttle is changed by utilizing the flow of the pressure liquid, but is different in that a spring for opening the valve is used.

As shown in FIG. 9, the valve body 901 includes
A cylindrical valve chamber 901A is provided, and this valve chamber 90
A cylindrical valve body 902 having an outer diameter slightly smaller than the diameter of the valve chamber 901A is inserted in 1A. Disc 9
A closed surface is provided at one end of 02, and an end portion 902A having a flat end surface is provided at the other end. further,
A valve lid 903 is fastened to one end of the valve chamber 901A.

The valve lid 903 has an end portion 9 of the valve body 902.
A valve seat portion 903A that comes into contact with 02A to close the flow is provided, and a discharge port 903B is provided inside the valve seat portion 903A. A spring 9 is provided between the valve lid 903 and the valve body 902.
04 is provided to urge the valve element 902 in a direction away from the valve seat 903A. It should be noted that a part of the valve body 902 has a pore 902 communicating the outer circumference and the inner circumference in the vicinity of the end portion 902A.
B is provided.

The operation of the present embodiment having the above configuration is as follows. First, during operation of the piston pump 1, the pressure on the side opposite to the valve lid 903 of the valve body 902 becomes high, and the liquid flows from the gap between the valve body 902 and the wall surface of the valve chamber 901A of the valve body 901 to cause the valve lid 903 to move. It flows out through the outlet 903B. In this process, a pressure difference is generated on both sides of the closed surface of the valve body 902, and the pressure difference drives the valve body 902 to the right side in the figure, and its end 902A abuts the valve seat 903A to close the flow. To do. By this operation, most of the pressure liquid from the piston pump 1 is supplied to the hydraulic drive system 80 side.

However, part of the pressurized liquid from the piston pump 1 flows out from the pore 902B connecting the outer circumference and the inner circumference near the end 902A of the valve body 902 through the discharge port 903B of the valve lid 903. In this state, when the operation of the piston pump 1 is stopped or the discharge of the piston pump 1 is stopped, the valve body 9
Due to the presence of the flow path that flows out from the fine hole 902B of No. 02 through the discharge port 903B of the valve lid 903, the pressure difference between both sides of the valve body 902 disappears. As a result, the valve body 902 has the spring 904.
The valve is opened by being driven to the left side in the figure by the urging force of.

As described above, according to the present embodiment, as in the fifth embodiment, the valve body 902 is operated by utilizing the flow of the pressure liquid to easily and surely throttle the flow rate. You can Moreover, in the present embodiment, the spring 903 is used.
Since the valve element 902 is biased in the direction away from the valve seat portion 903A by the valve seat portion 903A, when the piston pump 1 is stopped, the valve is reliably opened to reliably increase the flow rate, and the discharge check valve 18 and the line of FIG. Since the pressure in the conduit between the check valves 31 can be surely lowered, it is possible to reliably prevent the boosting failure from occurring at the time of starting the piston pump 1. Therefore, the operational reliability can be further improved.

In the present embodiment, the valve body 902
The amount of movement of is the volume displaced by the movement,
It suffices if the piston pump 1 has a capacity of several revolutions. This is because the gas discharged from the piston pump 1 is compressed to a gas volume determined by the compression ratio of the piston pump 1, and is normally discharged from the piston chamber 16 with one rotation of the piston pump 1.

[4. Other Embodiments] The present invention
The present invention is not limited to the above-mentioned embodiments, and various other forms can be implemented within the scope of the present invention.

For example, when the invention according to claim 14 is applied and the openings of the discharge ports of various pressure release elements are provided in the air, the discharge check valve 18 and the line check valve of the piston pump 1 are provided. It is provided in the vicinity of the highest position of the pipe line between 31, and is configured so that the opening of the discharge port is directed in a direction other than the downward direction. With this configuration, it is possible to prevent the working fluid in the pipe line from being replaced with air, and to prevent an increase in the gas dissolution rate. That is, if the gas dissolution rate in the high-pressure part of the hydraulic operating device is high, it is likely to cause valve operation delay, vibration, pitting corrosion of the valve part, etc., but these can be prevented. Also, when the opening of the discharge port of each pressure release element faces downward in the air, when the liquid dries, the liquid in the narrow gap may stick and change the flow rate characteristic, By orienting the opening in a direction other than the downward direction, only the liquid surface of the opening becomes a film-like high-viscosity state, and drying of the narrow gap inside is less likely to occur.

On the other hand, as described in each of the above-mentioned embodiments, it is also possible to adopt a structure in which the discharge ports of various pressure release elements are introduced into the liquid by piping. When this configuration is adopted, it is possible to prevent the inconvenience caused by the above-described arrangement of the opening of the discharge port in the air.

Further, the concrete structure of the pressure exhaust device in the present invention can be changed as appropriate, and the circuit structure of the entire hydraulic operating device and the means of each part, that is, the piston pump,
Specific configurations of the check valve, the pressure accumulator, the hydraulic drive device, the pressure detecting means, the pressure exhaust valve, and the like can be appropriately changed.

[0107]

As described above, according to the present invention,
Compact and simple with a check valve between the discharge check valve of the piston pump and the pressure accumulator that prevents backflow of high-pressure hydraulic fluid and a pressure release device that releases the pressure on the side opposite the piston check chamber of the discharge check valve. With this structure, when the piston pump is started, the pressure on the anti-piston side of the discharge check valve of the piston pump can be reduced to low pressure without lowering the pressure on the hydraulic drive side. It is possible to reliably prevent the occurrence of defects.

Further, even if the boosting failure of the piston pump occurs, the function of the piston pump can be easily restored without stopping the power switch, so that stable and continuous operation of the power switch can be achieved. It is extremely effective for securing. Further, various forms can be implemented by selecting the exhaust pressure device, and the system design can sufficiently cope with downsizing and cost reduction.

Therefore, according to the present invention, there is provided an excellent hydraulic operating device for an electric power switch, which is small in size, highly reliable in operation and can be manufactured at low cost by using a small and inexpensive piston pump. it can.

[Brief description of drawings]

FIG. 1 is a system diagram showing a basic embodiment of a hydraulic operating device for a power switch according to the present invention.

FIG. 2 is a cross-sectional view showing a first embodiment of a pressure relief element according to the present invention.

FIG. 3 is a sectional view showing a second embodiment of the pressure relief element according to the present invention.

FIG. 4 is a sectional view showing a third embodiment of a pressure relief element according to the present invention.

FIG. 5 is a sectional view showing a fourth embodiment of a pressure relief element according to the present invention.

FIG. 6 is a sectional view showing a fifth embodiment of a pressure relief element according to the present invention.

FIG. 7 is a sectional view showing a sixth embodiment of a pressure relief element according to the present invention.

FIG. 8 is a view showing two embodiments of a pressure release element according to the present invention, (A) is a sectional view showing a seventh embodiment,
(B) is sectional drawing which shows 8th Embodiment.

FIG. 9 is a sectional view showing a ninth embodiment of a pressure relief element according to the present invention.

FIG. 10 is a system diagram showing an example of a conventional hydraulic operating device for a power switch.

[Explanation of symbols]

 1: Piston pump 2: Preliminary pressurizing pump 11: Drive shaft 12: Cam 13: Cylinder 14: Spring 15: Piston 16: Piston chamber 17: Suction check valve 18: Discharge check valve 21: Suction filter 22: Line filter 41, 42: Stop valve 43: Relief valve 50: Pressure release element 51: Leakage element 61: Pressure switch 62: Pressure gauge 70: Accumulator 80: Hydraulic drive system 101-105: Oil tank 201: Block 201A: Pipe line 202: Joint 202A: hole 203: low-pressure pipe 203A: pipe line 204: filter 205: fine hole 206: seal part 207: seal packing 301: block 302: hole 303: shaft 304, 305: lid 306, 307: communication hole 308: circumference Groove 309: Large diameter part 401: Block 401A: Pipe line 402: Joint 402A Hole 405: Thin tube 407: Seal packing 501: Block 501D: Large diameter hole 501F, 502F: Flat surface portion 501H: Pipe line 502: Joint 502H: Hole 503: Flat plate 504: Recessed portion 505: Coiled groove 506: Seal component 507: Connection Part 508: Gap 601: Block 601A: Large diameter hole 601H: Pipe line 602: Joint 602F: Flat part 602H: Hole 603: Flat plate 605: Gap 606: Sealing part 701: Block 701A: Valve chamber 701E: Discharge port 701H: Needle Hole 701M: Main pipelines 701S, 702S: Threaded portion 702: Valve rod 702L: Knob 702N: Conical portion 706: Sealing component 801: Electromagnetic valve body 801A: Valve chamber 801B: Valve seat 801C: Valve rod chamber 802: Valve 803: Spring retainer 804: Spring 805: Valve rod 8 05A: Pressing part 805B: Movable piece 806: Sealing part 807: Electromagnet 807A: Coil 807B: Lid 807C: Spring 901: Valve body 901A: Valve chamber 902: Valve body 902A: End 903B: Pore 903: Valve lid 903A: Valve seat 903B: Discharge port 904: Spring

Claims (14)

[Claims] 1. A piston pump for boosting the working fluid, a first check valve provided on the discharge side of the piston pump, and a working fluid pressurized by the piston pump and supplied from the first check valve. A pressure accumulating device for accumulating pressure, a hydraulic pressure driving device for hydraulically driving with a hydraulic fluid supplied from the pressure accumulating device, and a hydraulic fluid supply line from the piston pump to the hydraulic pressure driving device via the pressure accumulating device. And a pressure detecting means for detecting the pressure of the working fluid in the supply line, and a discharge pressure valve for releasing the pressure of the working fluid in the supply line, and the piston pump of the piston pump according to the pressure detected by the pressure detecting means. The liquid of the power switch configured to maintain the pressure of the hydraulic fluid in the supply line within a preset range by controlling the operation and operating the exhaust pressure valve when the pressure rises too much. Pressure In the operating device, a second check valve for preventing backflow of high-pressure hydraulic fluid to the piston pump side is provided between the first check valve in the supply line and the pressure accumulator, and Between the second check valve and the piston pump, there is provided a pressure release device for releasing the pressure on the side opposite to the piston chamber of the first check valve when the piston pump is started, and an electric power opening / closing Hydraulic operating device. 2. The exhaust device is a throttle element that is always open, and the throttle element is set so that the outflow amount thereof is equal to or less than the discharge amount of the piston pump at the maximum working pressure state. A hydraulic operating device for a power switch according to claim 1. 3. The hydraulic operating device for a power switch according to claim 2, wherein the throttle element is a throttle channel formed by an orifice-shaped fine hole. 4. The hydraulic pressure for a power switch according to claim 2, wherein the throttle element is a throttle channel formed by a gap between a cylindrical hole and a shaft penetrating the hole. Operating device. 5. The hydraulic operating device for a power switch according to claim 2, wherein the throttle element is a throttle channel formed by a thin tube wound in a coil shape. 6. The diaphragm element includes a first member having a flat surface portion and a coil-shaped groove provided therein having a predetermined depth, and a second member having a flat surface portion having no groove. 3. The hydraulic operating device for a power switch according to claim 2, wherein the throttle-shaped flow path is a coil formed by overlapping the parts. 7. The throttle element includes a fixing member having a discharge port and a flat surface portion, and a flat plate movably arranged on the supply line side thereof, and the flat plate is moved by a flow of hydraulic fluid during operation of the piston pump. The electric power switch according to claim 2, wherein the plate is configured to be in a free state when the piston pump is stopped by moving to the fixed member side to limit an outflow amount from the discharge port. Hydraulic operating device. 8. The hydraulic operating device for a power switch according to claim 2, wherein the throttle element is a needle valve. 9. The hydraulic pressure operation device for a power switch according to claim 1, wherein the exhaust pressure device is an electromagnetic valve. 10. The hydraulic operating device for a power switch according to claim 9, wherein the solenoid valve is always closed and is configured to be opened only for a short time only when the piston pump is started. 11. The hydraulic operating device for a power switch according to claim 9, wherein the solenoid valve is always open and is closed when the piston pump is activated. 12. The hydraulic pressure control device for a power switch according to claim 1, wherein the exhaust pressure device is a normally open manual open valve that is manually opened. 13. The pressure relief device includes a valve chamber, a valve body inserted into the valve chamber, a valve seat portion that abuts against the valve body to stop the flow, and a drainage chamber provided inside the valve seat portion. The valve seat has an urging means for urging the valve body in a direction away from the outlet and the valve seat portion, and when the piston pump is in operation, the valve body is caused by the differential pressure generated by the flow resistance of the hydraulic fluid. The valve body is configured to move to the side of the valve seat to limit the amount of outflow from the discharge port, and when the piston pump is stopped, the valve body is moved in a direction away from the valve seat portion by the biasing means. A hydraulic operating device for a power switch according to claim 1. 14. The pressure releasing device has a pressure releasing outlet opening into the air, and the outlet has the first check valve and the second check valve in the supply line. The hydraulic operating device for a power switch according to any one of claims 1 to 13, wherein the hydraulic operating device is arranged at the highest position between them so as to open in a direction other than the downward direction.