JPH07320601A - Hydraulically operated dispenser - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the performance at the time of making operation so as to satisfy the required making performance. [Structure] The oil chamber 22 on the side through which the piston shaft 24 penetrates the accumulator 3
To the accumulator 3 as a high pressure oil supply source and the oil tank 7 as a normal pressure oil supply source by the main valve 4 as a three-way valve. The oil chamber 23 in the non-closed state.
The high pressure oil in the oil chamber 22 communicating with the accumulator 3 is changed by the main valve 4 controlled by the operation unit 6 via the auxiliary valve 5 so as to communicate with the oil tank 7 during the charging operation. All the pushing force of the hydraulic piston 21 becomes the driving force of the operating rod 14, and the pushing force of the hydraulic piston 21 in the oil chamber 23 communicating with the oil tank 7 can be substantially ignored.
As in the conventional case, a much larger driving force can be obtained as compared with the driving force obtained by applying hydraulic pressure to the cross-sectional area of the piston shaft 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injector for supplying power to a load for supplying a large current to the load in a short-circuit test facility, and more particularly to a hydraulically operated injector.

[0002]

2. Description of the Related Art The basic structure of a circuit breaker is similar to that of a circuit breaker, and its main purpose is to protect the system by interrupting a large current such as a fault current generated in the power system. On the other hand, the injector is mainly intended to apply power to the load. In the case of test equipment, in most cases, after a given current value flows into the load at a given voltage after turning on, these voltages and currents are attenuated, so the breaking performance by the injector is not really important in practice. .

FIG. 3 is a vertical cross-sectional view showing an example of the hydraulically operated feeder, and shows a cross section of the main body excluding the hydraulically operated device. In this figure, the main body 1 of the injector is a hydraulic actuator 100 which is provided below the insulators 12 and 12 of two layers stacked vertically, the lid 13 that covers the upper part of the insulator 11 of the upper stage, and the insulator 12 of the lower part.
A fixing metal fitting 15 having a flange for fixing and supporting the injector, a movable fitting 16 mounted near the upper end of the operating rod 14, and a terminal pulled out from the upper part of the insulator 11 while the operating rod 14 connecting with 17 and a fixed contact 18A electrically connected to this terminal 17, a terminal 19 drawn out from the lower portion of the insulator 11 and another fixed contact 18B electrically connected to this terminal 19. Further, a guide rod 141 is provided on the upper end portion of the operation rod 14 further above the movable contact 16, and the guide rod 141 penetrates the cylindrical portion of the guide fitting 142 so that the operation rod 14 does not shake. It has a stable structure. The lid 13, the insulators 11 and 12, and the fixing member 15 are connected and fixed in an airtight manner at their connecting portions by connecting members without reference numerals. The inside of the main body of such a hydraulic operation type injector is hermetically sealed, and an insulating gas having a predetermined pressure is filled therein, and the performance outside the insulation is maintained.

An insulating rod is inserted at a position corresponding to the central portion of the insulator 12 of the operating rod 14, and is connected to the upper and lower metallic operating rods via connecting fittings. This figure shows the non-closed state, that is, the open state of the thrower, and the movable contact 16 is in contact with the upper fixed contact 18A but at a position apart from the lower fixed contact 18B. There are two fixed contacts
18A and 18B are open. When the operating rod 14 is moved downward by being driven by the hydraulic actuator 100, the movable contact point 16 contacts not only the fixed contact point 18A but also the fixed contact point 18B, and the two fixed contact points 18A and 18B are short-circuited. It becomes a "closed" state. The main purpose of the injector is to close the external circuit connected to the terminals 17 and 19 from the "open" state to the "closed" state as described above.

As described above, the closing device has a structure similar to that of the circuit breaker, and the operation by the hydraulic actuator 100 also changes the breaking operation from the "closed" state to the "open" state in accordance with the circuit breaker. It is configured such that a larger driving force and a higher speed breaking operation are performed during operation.

[0006]

As described above, the performance of the injector during the closing operation is of the utmost importance. The performance required for the injector is listed below. 1) A larger current can be applied. 2) There is little advance discharge. 3) Do not change the input time. 4) Less wear of contacts. 5) The closing phase can be adjusted. 6) Easy maintenance and inspection.

Since the conventional hydraulically operated closing device is constructed to have a structure and performance similar to that of the circuit breaker as described above, the performance at the time of breaking is excellent, but the driving force is insufficient at the time of closing. There is a problem in that the moving speed of the movable contact 16 is low, and as a result, many of the above-mentioned performance requirements are not satisfied. An object of the present invention is to solve such a problem and to provide a hydraulically operated dispenser capable of improving performance at the time of making operation and satisfying required performance.

[0008]

In order to solve the above problems, according to the present invention, two oil chambers in a hydraulic cylinder divided by a hydraulic piston are controlled by a three-way valve to accumulate high-pressure oil. Piston shaft penetrates in a hydraulically operated dispenser in which an operating rod connected to a hydraulic piston is driven via a piston shaft due to the difference in force generated between the oil chambers communicating with the accumulator or normal pressure oil tank. The oil chamber on the operating side is always in communication with the accumulator, and the other oil chamber is switched between the communication with the accumulator and the communication with the oil tank by the three-way valve. Communication, communication with the oil tank during the charging operation.

[0009]

In the structure of the present invention, the oil chamber on the side through which the piston shaft penetrates is always connected to the accumulator, and the other oil chamber is connected to the accumulator by the three-way valve and to the oil tank. The oil chamber communicates with the accumulator in the non-discharging state, and the high pressure oil in the oil chamber communicating with the accumulator pushes the hydraulic piston by switching to communicate with the oil tank during the charging operation. All the force becomes the driving force of the operating rod. The force pushing the hydraulic piston in the oil chamber communicating with the oil tank can be substantially ignored.

[0010]

EXAMPLES The present invention will be described below based on examples.
1 and 2 are hydraulic system diagrams of a hydraulic operating device showing an embodiment of the present invention, and FIG. 1 shows a state in which an operating rod 14 is located above the movable contact 16 of the injector of FIG. 2 shows a state where the operating rod 14 is lowered by performing the inserting operation from the state of FIG. In these figures, the hydraulic actuator 10
Reference numeral 0 denotes a hydraulic piston 2, an accumulator 3 which is generally called an accumulator, a main valve 4 which is a three-way valve, an auxiliary valve 5 which has the same structure as the main valve 4 but is small in size, and an operating portion for performing opening and closing operations. 6, an oil tank 7, a hydraulic pump indicated by P in the circle, an electric motor indicated by M in the circle that drives this hydraulic pump, and piping as an oil passage connecting these. The parallel diagonal lines rising to the right in the figure are the main valve 4 and auxiliary valve 5.
The upper left parallel slanted line communicates with the accumulator 3 in the pipe or the like and is filled with high pressure oil, and the dotted part communicates with the oil tank 7 and is filled with normal pressure oil. It is the part that was done. As is well known, since oil is an incompressible material, fluctuations in its volume can be ignored at high pressure and normal pressure. Therefore, as will be described later, even if there is a change in pressure from the high pressure oil to the low pressure oil or vice versa by switching by the auxiliary valve 5 and the main valve 4, the hydraulic pressure will only change instantaneously.

The accumulator 3 stores high-pressure oil of several hundreds of atmospheres generated by the hydraulic pump P, and is filled with nitrogen (N ₂ ) gas so that the hydraulic pressure does not suddenly fluctuate due to supply and accumulation of the hydraulic pressure. Therefore, the high pressure oil is supplied to the entire hydraulic system from the accumulator 3. The hydraulic pump P is driven by the electric motor M when the oil pressure in the accumulator 3 drops below a predetermined value to generate high-pressure oil from the oil in the oil tank 7 to generate accumulator 3
To replenish.

The operation unit 6 is for operating the closing and the tripping operations of the throwing device, and is made up of the throwing coil 61 and the tripping coil.
62, valve bodies 63 and 65 interlocking with these, and a valve body 64 that cannot be operated from the outside. When the closing button is pressed, the closing coil 61 is excited and the corresponding valve body 63 is pushed downward to open the valve in this portion, and in the same manner, the tripping coil 62 is pressed by pressing the tripping button.
Is excited and the corresponding valve body 65 is pushed downward to open the valve in this portion. At this time, the valve body 64 is also pushed downward in conjunction with the valve body 65 to open the valve. .

In the hydraulic cylinder 2, a hydraulic piston 21 is moved in the vertical direction in the figure, and an operating rod 14 connected to a piston shaft 24 fixed to the hydraulic piston 12 is the operating rod 14 in FIG. . As shown in FIG. 1, when the hydraulic piston 21 is on the upper side corresponds to the “open” state of the main body of the injector shown in FIG. 3, and when the hydraulic piston 21 is moved downward as shown in FIG. The state of “”, that is, the input state.

The hydraulic cylinder 2 is divided into two upper and lower oil chambers 22 and 23 by a hydraulic piston 21, the upper oil chamber 22 is directly connected to the accumulator 3 by a pipe, and the lower oil chamber 23 is mainly Of the three output pipes of the valve 4, the pipe shown in FIG. Three pipes indicated by A, B, and C are connected to the main valve 4, and it is possible to switch communication between A and C or B and C depending on the position of the valve body 41. In FIG. 1, the valve body 41 is located on the right side and the pipe A is cut off so that the pipes B and C
Are in communication with each other. Therefore, the oil chamber 23 is in communication with the accumulator 3 through the pipe C and is supplied with high-pressure oil. In this state, high pressure oil of the same pressure is supplied to the upper and lower oil chambers 22 and 23, but as will be described later, the hydraulic piston 21 is moved in the oil chamber 23 by an amount equivalent to the pressure applied to the cross-sectional area of the piston shaft 24.
Is greater than the force that pushes down the hydraulic piston 21 downward, and this force causes the hydraulic piston 21 to be in a stable and stationary state at the upper position as shown in the figure. In this figure, hydraulic piston 21 and hydraulic cylinder 2
Although it is illustrated as if it stopped halfway through, it actually hits the upper stopper and stands still.

When the valve body 41 moves to the right as shown in FIG. 2, the pipes A and C communicate with each other, but the pipe A is the oil tank 7 at normal pressure.
Since the oil chamber 23 is in communication with the oil tank 7, the force pushing up from the lower surface of the hydraulic piston 21 disappears and a downward driving force is generated to move downward. Oil passes through pipes C and A to the oil tank 7
The hydraulic piston 21 is further moved downward and the movable contact 16 in FIG. 3 is moved downward to move the fixed contact 18A and the fixed contact 18
Short-circuits with B and enters the closed state.

Similarly to the main valve 4, the auxiliary valve 5 is also connected with three pipes indicated by a, b, and c, and the pipe communicating with c can be switched to a or b depending on the position of the valve body 51. . In this figure, the valve body 51 is located on the right side, and a is blocked and b and c are in communication. Both the main valve 4 and the auxiliary valve 5 have a structure in which two large balls and two small balls are provided at the right end of the valve bodies 41 and 51, and springs are provided at both ends of the valve bodies 41 and 51, respectively. However, in these configurations, the hydraulic pressure of the accumulator 3 is lowered and the hydraulic actuator
Even when the normal operation of 100 becomes impossible, the valve body 41,51
It has a self-holding function to keep the position of. Since the structure of both the main valve 4 and the auxiliary valve 5 is the same in the conventional hydraulic actuator and is not directly related to the present invention, detailed description thereof will be omitted.

In FIG. 1, all three valve bodies 63, 64, 65 of the operating portion 6 are in the "closed" state. These valve bodies are "open" only when the closing coil 61 or the tripping coil 62 are in the excited state, and after the required time has passed, the excitation is cut off and "closed" as shown in the figure. This is because After the excitation is cut off, the state after the closing or tripping operation is performed based on the self-holding function described later is maintained until the next tripping or closing operation is performed.

The self-holding function is as follows. In FIG. 1, a narrowed portion 8 is provided in the middle of a pipe communicating from the pipe c to the left end side of the valve body 51. Since this pipe supplies high-pressure oil to the left side of the valve body 51 via the pipe b, the operating portion 6
Even if the high pressure oil is not supplied through the valve, the force pressing the valve 51 to the right acts to maintain the valve element 51 in the right position as shown in FIG. When transitioning to the closed state of FIG. 1 and FIG. 2, or vice versa, the throttle portion 8 operates and this pipe cannot follow a sudden change in hydraulic pressure, and thus the throttle portion 8 is in the process of transition. It becomes the same as there is no piping with.

The main valve 4 maintains the state shown in FIG. 1 by pressing the valve body 41 to the right from the pipe c which is the output of the auxiliary valve 5. That is, due to the self-holding function of the auxiliary valve 51, the main valve 4
This state is also maintained. The hydraulic piston
Even in the closed state of FIG. 2 in which 21 has moved downward, the left end side of the valve element 51 is maintained at normal pressure through the pipe having the throttle portion 8 and the position of the valve element 51 is maintained at the left side.

The auxiliary valve 5 is used because the auxiliary valve 5 is provided when the size of the operating portion 6 required to control the main valve 4 is insufficient and the auxiliary valve 5 is operated. The configuration is such that the small operation portion 6 corresponding to the small auxiliary valve 5 is used. In order to cause the throwing device to perform the closing operation, the valve body 41 may be moved to the left. For that purpose, the operator may press the closing button of the operation unit 6 to excite the closing coil 61. . The operation of the hydraulic system after this will be described below. The closing coil 61 is excited, the valve element 63 is pushed downward, and the valve in this portion is opened. Since the left end side of the valve body 51 of the auxiliary valve 5 communicates with the oil tank 7 through this valve, the valve body 51 is pushed to the left. As a result of the valve body 51 moving to the left, the pipes b and c are cut off and the pipe a communicates with c. The left end side of the valve body 41 of the main valve 4 communicates with the oil tank 7 through the pipe c of the auxiliary valve 5, and as a result, the valve body 41 is pushed to the left and the pipes A and C communicate with each other so that the oil chamber 23 is filled with oil. The force that pushes up the hydraulic piston 21 in the oil chamber 23 in communication with the tank 7 disappears. Since the oil chamber 22 communicates with the accumulator 3, the hydraulic piston 21
Is pushed downward and the oil in the oil chamber 23 is collected in the oil tank through the main valve 4. The operating rod 14 connected to the hydraulic piston 21 is a hydraulic piston.
The movable contact 16 connected to the operating rod 14 shown in FIG. 3 is moved downward with 21 to move the fixed contacts 18A and 18B to a short circuit. Due to the self-holding function of the throttle portion 8, both the valve elements 41 and 51 stop at the positions shown in FIG. 2, and the closing state is maintained until the trip coil 62 is excited thereafter.

In order to perform a so-called tripping operation in which the feeder is in the "closed" state from the closed state to the "open" state, the tripping button is pushed to excite the tripping coil 62. The following tripping operation is as follows. The valve body 65 is opened so that the upper portion of the valve body 64 and the accumulator 3 are communicated with each other, whereby the valve body 64 is also lowered and the left end side of the valve body 51 of the auxiliary valve 5 is communicated with the accumulator 3. Since the high-pressure oil is supplied to the left side of the valve body 51, the valve body 51 moves to the right (the position in FIG. 1) and the pipe a is blocked and the pipe b is cut off.
Communicates with c. The left end side of the valve body 41 of the main valve 4 communicates with the accumulator 3 through the pipe c of the auxiliary valve 5, the valve body 41 moves to the right (the position in FIG. 1), the pipe A is shut off, and the pipe B Communicates with C. The oil chamber 23 communicates with the accumulator 3 through the pipe C, and high-pressure oil is supplied. The force that pushes the hydraulic piston 21 upward in the oil chamber 23 is the hydraulic pressure applied to the entire lower surface of the hydraulic piston, but the force that pushes the hydraulic piston 21 downward in the oil chamber 22 is the upper surface excluding the axis of the hydraulic piston 21 and therefore the axial cross section. Since the force pushing upward by the integral is large, the hydraulic piston 21 returns from the lower position in the closed state to the upper position as shown in FIG.

As described above, the force that pushes down the hydraulic piston 21 during the closing operation is the area of the upper surface of the hydraulic piston 21 (S ₁ ), that is, the area of the lower surface (S ₂ ).
Area obtained by subtracting the Jikudan area (a S ₃₎ from (S ₁ =
A value obtained by multiplying S ₂ -S ₃ ) by hydraulic pressure (denoted by p) {p (S ₂
Is -S _3)}. Since the oil pressure in the oil chamber 23 is normal pressure, the force pushing it up from the lower surface can be ignored. On the other hand, the force that pushes up the hydraulic piston 21 during the tripping operation is the value obtained by multiplying the axial cross-sectional area (S ₃ ) by the hydraulic pressure p (pS ₃ ) as described above.
Is. Generally, since S ₃ << S ₂ , the force for driving the hydraulic piston 21 during the closing operation is much larger than that during the tripping operation. As a result, the moving speed of the movable contact 16 during the closing operation of the hydraulically operated closing device becomes faster, and the closing performance is greatly improved as compared with the conventional closing device that generates a large driving force at the time of tripping like the circuit breaker. It

[0023]

As described above, according to the present invention, the oil chamber on the side where the piston shaft does not penetrate during the closing operation is switched from the state in which the oil chamber is in communication with the accumulator to the oil tank by the main valve. The hydraulic pressure in the chamber becomes normal pressure, and the force pushing the hydraulic piston becomes practically negligible,
All of the force that the other oil chamber communicating with the accumulator pushes the hydraulic piston becomes the driving force of the operating rod. As a result, the movable contact has a much larger driving force than that of the conventional throwing device, and the movable contact can move at a high speed, so that the throwing performance is significantly improved.

[Brief description of drawings]

FIG. 1 is a hydraulic system diagram of a hydraulic actuator of a hydraulically operated dispenser in a non-closed state showing an embodiment of the present invention.

FIG. 2 is a hydraulic system diagram of the hydraulic actuator of FIG. 1 in a closed state.

FIG. 3 is a cross-sectional view of the main body of the hydraulically operated dispenser.

[Explanation of symbols]

1 ... Feeder body, 14 ... Operation rod, 18A, 18B ... Movable contact, 16
… Movable contact, 100… hydraulic actuator, 2… hydraulic cylinder, 21
... hydraulic pistons, 22, 23 ... oil chambers, 24 ... piston shafts, 3 ...
Accumulator, 4 ... Main valve (three-way valve), 41 ... Valve body, 5 ... Auxiliary valve,
51 ... Valve body 6 ... Operating part, 61 ... Looking coil, 62 ... Tripping coil, 6
3,64,65 ... Valve element, 7 ... Oil tank, 8 ... Throttle section

Claims (1)

[Claims] 1. Two oil chambers in a hydraulic cylinder divided by a hydraulic piston are connected to an accumulator or an oil tank of normal pressure controlled by a three-way valve to accumulate high-pressure oil, and are placed in respective oil chambers. In a hydraulically operated dispenser in which an operating rod connected to a hydraulic piston is driven via a piston shaft due to a difference in generated force, the oil chamber on the side through which the piston shaft penetrates is always in communication with the accumulator, and the other oil chamber is , A three-way valve switches between communication with the accumulator and communication with the oil tank. When the oil chamber is in the non-closed state, it communicates with the accumulator and the oil tank during the closing operation. Formula thrower.