KR100248936B1 - Fluid pressure drive device df breaker - Google Patents

Abstract

The present invention relates to a fluid driving device which performs opening and closing of a contactor of a circuit breaker by a fluid pressure, and includes a working fluid in order to reduce a change in operating frequency and operating time of a pump even if the viscosity of the working fluid changes due to temperature change. Reservoir, pump for pressurizing working fluid to discharge to supply line, accumulator connected to supply line and accumulating working fluid pressurized from pump, fluid pressure cylinder for opening / closing contactor of breaker, connecting fluid pressure cylinder to supply line The working fluid flow path control means, which is provided through the pipeline and controls the supply and discharge of the working fluid to the hydraulic cylinder, the pressure monitoring means for detecting and outputting the supply of the working fluid accumulated in the accumulator, and the working fluid accumulated in the accumulator Pump according to the output signal from the leaking means or the pressure monitoring means It was set as the structure which has a pump control means which starts and stops and operates so that a supply pressure may be kept between a predetermined upper limit and a lower limit.

With this arrangement, it is possible to reduce the variation in the number of operation and the operation time of the pump for maintaining the supply pressure within a predetermined range, and to perform the predetermined operation reliably, so that the fluid pressure of the reliable breaker The effect that the drive device and the breaker can be realized is obtained.

Description

Fluid pressure drive of breaker

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for a power circuit breaker, and more particularly, to a fluid drive device for opening and closing a contactor of a breaker by fluid pressure.

The breaker performs the opening and closing of the contactor at the time of stopping the power supply for emergency or inspection of lightning, etc., and then restarting the power supply afterwards. Such opening and closing of the narrow contactor of the breaker may be performed by a fluid pressure device. The opening and closing device of the circuit breaker by the fluid pressure is less frequent than the fluid pressure device of the general industrial use, the waiting time is much longer. Therefore, the switchgear (fluid pressure drive device) of the breaker does not operate the pump at all times as in a general fluid pressure device, but accumulates the high pressure working fluid discharged from the pump in the accumulator, that is, the pressure of the working fluid accumulated in the accumulator, Only when the supply pressure falls, the pump is operated to raise the supply pressure to a predetermined pressure. Therefore, in order to maintain the supply pressure within a predetermined range, a pressure monitoring means such as a pressure switch is used to monitor the supply pressure. When the supply pressure reaches the preset lower limit value, the pump is started to start the boosting pressure when the upper limit value is reached. The structure which stops a pump is employ | adopted.

In terms of energy saving and longevity, it is preferable to reduce the number of operation and the operation time of the pump.However, to operate the pump at a certain frequency in order to start and increase the pressure without failing to start it or failing to boost it quickly, It is preferable.

For this reason, the fluid pressure drive device of the conventional circuit breaker provides a pipe connecting the outlet of the pump and the accumulator, that is, a flow path connecting the supply pressure line and the low pressure side pipe connecting the suction side and the reservoir of the pump. A throttle is provided in the flow path to form a leaking means, and the working fluid is constantly leaked from the accumulator to the reservoir.After the pump stops, the supply pressure gradually decreases, and after a certain time, the pump reaches the lower limit of the supply pressure. I was trying to maneuver.

Alternatively, for example, a solenoid valve is provided on a flow path connecting the supply pressure side and the low pressure side as described in Japanese Patent Application Laid-Open No. Hei 3-245421, which is opened regularly to lower the supply pressure. Mechanisms to start regularly were used.

In the configuration of the first conventional technique, since the flow path cross section area of the throttle is constant, the leakage amount changes when the viscosity of the working fluid changes with the temperature change of the surrounding (external air). As a result, there has been a problem that the operating frequency and the operating time of the pump greatly change. This is because the flow rate of leakage is very small, so the orifice throttle cannot be used because the flow rate is too large to use an annular throttle or capillary throttle, and the flow rate leaking through these throttles is inversely proportional to the viscosity of the working fluid. For example, the leakage amount Q _L at the time of using a cyclic throttle is represented by the formula of the flow volume of the cyclic gap represented by Formula (1).

[Equation 1]

Here, d is the diameter of the fin, L is the axial length of the annular gap, δ is the size of the radial gap, μ is the viscosity of the working fluid. Δp is the pressure difference on the upstream and downstream sides, that is, the pressure obtained by subtracting the pressure on the low pressure side from the supply pressure ps, and Δp is equal to ps since the pressure on the low pressure side is usually the same as the atmospheric pressure.

Since the viscosity of the working chute decreases at high temperatures and increases at low temperatures, the leakage amount increases with temperature rise and decreases with temperature drop if the radial gap δ that determines the flow path cross-sectional area of the throttle is constant. Therefore, in the summer or in a warm area, the amount of leakage increases, so that the number of times of operation and operating time of the pump increases, which leads to an increase in energy consumption and shortening the life of the pump or the relay of the driving device. There was. On the contrary, in winter and cold areas, the amount of leakage decreases, so that the number of times of operation or operating time decreases, and the sliding part in the pump tends to stick, resulting in an increase in sliding resistance, leading to deterioration in efficiency and inability to start smoothly. There was a case.

Also, as long as there is a difference in pressure between the upstream and downstream sides of the throttle, leakage of the working fluid continues, so if the pump cannot be started or the normal pressure can not be increased, the supply pressure will continue to decrease even if it falls below the lower limit. In some cases, there was a problem that the circuit breaker lowered to a pressure at which the circuit breaker could not be driven.

On the other hand, in the second prior art configuration, a drive device for driving the solenoid valve or a timer for opening it regularly is required, and therefore, a failure of the solenoid valve or drive device, etc., which complicates the configuration of the device, is required. There was a problem such as need to prepare for the trouble. Also in this configuration, if the operation of opening the solenoid valve without the pump being started is repeated, there is a problem that the supply pressure is too low to drive the circuit breaker.

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems in the prior art as described above, and to reduce the operating frequency of the pump and the variation of the operating time for maintaining the supply pressure within a predetermined range even if the viscosity of the working fluid changes due to temperature change. If it is impossible to increase the pressure by the pump normally, the leakage of the working fluid is stopped to prevent the supply pressure from dropping further.

1 is a system diagram showing a closed state in one embodiment of a fluid pressure drive device according to the present invention.

2 is a schematic diagram showing an open state in the embodiment of FIG.

3 is a cross-sectional view showing the configuration of the leaking means of FIG.

4 is a cross-sectional view showing the change in the throttle portion caused by the temperature of the leaking means in FIG.

FIG. 5 is a characteristic diagram showing the change of the leakage amount by the temperature of the leaking means of FIG.

6 is a cross-sectional view showing one embodiment of the leaking means and the channel opening and closing means of the present invention.

7 is a cross-sectional view showing a state in which the flow path opening and closing means of FIG. 6 is closed.

Fig. 8 is a characteristic diagram showing an example of the relationship between the supply pressure and the operating force in the flow path opening and closing means of Fig. 6;

9 is a sectional view showing another embodiment of the leaking means of the present invention.

10 is a sectional view showing another embodiment of the leaking means of the present invention.

Figure 11 is a sectional view showing another embodiment of the flow path opening and closing means of the present invention.

12 is a characteristic view showing another example of the relationship between the supply pressure and the operating force of the flow path opening and closing means of the present invention.

In order to achieve the above object, the present invention provides a leakage means having a throttle flow passage configured to change the cross-sectional area of the flow passage in accordance with the temperature change on the flow passage connecting the supply pressure side and the low pressure side. In other words, it is to provide a leaking means having a throttle flow path that the flow path cross-sectional area decreases with temperature rise and increases with temperature drop.

Specifically, it is preferable that the leakage means be configured as follows.

First, a first member having a tapered hole and a tapered pin to be fitted with an annular gap between the tapered hole are fitted at one end and a second member coupled to the first member at the other end is provided. Both gaps constitute a throttle flow path through which the working fluid flows, and one end of the throttle flow path is connected to the supply pressure side, and the other end is connected to the low pressure side. The taper of the taper hole and the taper pin tends to decrease in diameter as the taper portion moves away from the coupling portion of the first member and the second member. Next, at least a portion of the second member, preferably a portion between the tapered pin and the engaging portion to the first member, is made of a material having a larger coefficient of thermal expansion than the first member.

With the above configuration, when the temperature changes, the second member is stretched more than the first member, so that the axial relative positions of the inner surface of the tapered hole and the outer surface of the tapered pin change, so that the flow passage cross section area of the throttle changes. That is, when the temperature rises, the gap δ becomes smaller because the second member extends larger than the first member. On the contrary, when the temperature drops, the gap δ increases because the second member shrinks larger than the first member. In this way, since the flow path cross-sectional area of the throttle changes to become high at high temperatures and increases at low temperatures as the temperature changes, it is possible to suppress the variation in leakage amount proportional to the trigonometry of the gap δ divided by the viscosity μ even if the viscosity changes. Can be. Therefore, it is possible to suppress a small change in the operating frequency and the operating time of the pump for maintaining the supply pressure within a predetermined range. In addition, since the leakage amount is proportional to the third power of the gap δ, a large effect can be obtained only by changing the gap δ very small.

Further, the present invention provides a flow path opening and closing means configured to block the inflow of the working fluid to the leaking means when the supply pressure is upstream of the leak rate adjusting means. Specifically, a supply mechanism for closing and opening the flow opening and closing part such as a poppet valve, the input side connected to the supply pressure side, the output side upstream of the leaking means, and the flow opening and closing part being operated by an elastic member such as a spring and supplying A retrofit operation mechanism for operating the opening and closing of the flow path opening and closing by the pressure is provided, and when the supply pressure falls below a preset pressure, the closing force of the closing operation mechanism is greater than that of the retrofit operation mechanism for opening the flow path opening and closing part. Since the retrofitting force of the retrofit tool is the product of the hydraulic pressure area and the supply pressure, if the supply pressure falls below the predetermined lower limit, set the hydraulic pressure area of the retrofit tool so that the closed operation force of the retrofit tool becomes larger than the retrofit force. do.

In such a configuration, when the supply pressure is lower than the preset pressure, the flow path opening and closing part is closed to stop the leakage of the working fluid, so that the supply pressure can be prevented from falling below. Therefore, even if the normal boosting cannot be performed, such as when the pump is not started, the supply pressure drops abnormally and the breaker cannot be driven.

[Embodiment of the Invention]

Hereinafter, a first embodiment of a fluid pressure drive device for a circuit breaker of the present invention will be described with reference to FIGS.

The embodiment shown in FIG. 1 includes a reservoir 10 for storing a working fluid released to atmospheric pressure, a pump 5 for sucking and pressurizing the working fluid in the reservoir 10, and a motor for driving the pump 5 ( 18), the filter 6 which is in contact with the outlet of the pump 5, the supply pressure line 36 which is a supply side line connected to the output side of the filter 6, the accumulator 7 connected to the supply pressure line 36, Leakage means 16 provided through a pipe 41 connecting the supply pressure line 36 and the reservoir 10, and a rod side compartment (small water pressure area side section) in the supply pressure line 36. Breaker 80 comprising a fluid pressure cylinder 3 provided by connecting 4a, a contact comprising a fixed contactor 1 and a movable contactor 2, and configured to open and close the contact in the fluid pressure cylinder 3. ) And a pipe line 37 for communicating the supply pressure pipe line 36 with the cylinder head side section (large hydraulic pressure area side section) 4b of the fluid pressure cylinder 3. The main control valve 8 and the main outlet valve 8 provided to the reservoir 10 through the main control valve 8 and the main control valve 8 upstream of the main control valve 8 via the main pipe valve 38. The outlet of the pilot valve 11 and the pilot valve 11 connected to the input side and connected to the second pilot chamber 9b of the main control valve 8 by the conduit 42 is connected to the reservoir 10. The motor 18 is started by inputting the output signals of the pressure switch 15 and the pressure switch 15, which are pressure monitoring means for detecting and outputting the internal pressure of the pipeline 40 and the supply pressure pipeline 36, respectively. A reservoir valve which is connected to the pump control means 17 for stopping and the supply pressure line 36 and opens when the supply pressure exceeds a predetermined pressure to guide the working fluid in the supply pressure line 36 to the reservoir 10 ( 14) is configured to include. The main fluid valve 8 and the pilot valve 11 constitute a working fluid flow control means for sending the working fluid pressurized to the supply pressure to the fluid pressure cylinder 3 or discharging the working melt of the fluid pressure cylinder 3 to the reservoir. Doing.

In the hydrostatic pressure area side section 4a of the fluid pressure cylinder 3, which opens and closes the contact made up of the fixed contactor 1 and the movable contactor 2, the accumulator 7 passes through the filter 6 at the outlet of the pump 5; The supply pressure of the working fluid accumulated in the air is directly acting. The large hydraulic pressure area side section 4b of the fluid pressure cylinder 3 is selectively connected to the supply pressure side or the low pressure side connected to the reservoir 10 by switching the main control valve 8. The main control valve 8 includes a valve case, a valve body 9c slidably embedded in the valve case, a first pilot chamber 9a having one end face in the sliding direction of the valve body 9c as a hydraulic pressure wall surface; It is comprised including the 2nd pilot chamber 9b which makes a hydraulic end surface the other end surface of the valve 9c the sliding direction. The area of the pressure receiving wall surface of the second pilot chamber 9b is larger than the area of the pressure receiving wall surface of the first pilot chamber 9b. The valve body 9c has a force applied to the hydraulic pressure wall surface by the pressure of the working fluid of the second pilot chamber 9b than a force applied to the hydraulic pressure wall surface by the pressure of the working fluid of the first pilot chamber 9a. If it is large, it will be in the state shown in FIG. 1, and the large hydraulic-pressure area side compartment 4b of the fluid pressure cylinder 3 will communicate with the conduit 37, and the hydraulic pressure will be based on the pressure of the working fluid of the 2nd pilot chamber 9b. If the force applied to the wall surface is smaller than the force applied to the hydraulic pressure wall surface by the pressure of the working fluid of the first pilot chamber 9a, the state shown in FIG. The compartment 4b communicates with the conduit 39.

The pilot valve 11 has an opening driving means 12 and a closing driving means 13, and when the opening driving means 12 is operated, the second pilot chamber 9b of the main control valve 8 is piped. It connects to the low pressure side (storage 10) via 40, and when the closing drive means 13 operates, the 2nd pilot chamber 9b of the main control valve 8 is connected to the supply pressure side (pipe 38). It is configured to connect. The operation of the opening drive means 12 and the closing drive means 13 is controlled by a control circuit not shown. The supply pressure always acts on the first pilot chamber 9a of the main control valve 8.

Therefore, when the opening drive means 12 is operated in the closed holding state shown in FIG. 1, the pilot valve 11 moves the second pilot chamber 9b of the main control valve 8 to the low pressure side (pipe 40). ), The main control valve 8 is switched, and the main control valve 8 connects the large hydraulic pressure area side section 4b of the fluid pressure cylinder 3 to the low pressure side (pipe line 39). Since the hydrophobic pressure area side compartment 4a is always connected to the supply pressure pipeline 36, the fluid pressure cylinder 3 moves the piston to the right side in the drawing due to the supply pressure acting on the hydrophobic pressure area side compartment 4a. It moves to perform the opening operation, and turns to the state of FIG. 2, and electric power is cut off. On the other hand, when the opening drive means 13 is operated in the open state maintenance state shown in FIG. 2, the pilot valve 11 supplies the second pilot chamber 9b of the main control valve 8 to the supply pressure side (pipe 38). The main control valve 8 is switched in the opposite direction, and the main control valve 8 connects the large hydraulic pressure area side section 4b of the hydraulic cylinder 3 to the supply pressure side (pipe 37). The force to move the piston to the left in the drawing overcomes the force caused by the supply pressure acting on the hydrostatic pressure-side-side section 4a, performs the closing operation, returns to the state of FIG. 1, and resumes power transmission.

The supply pressure pipe line 36 is connected to the discharge port of the pump 5 via the filter 6, and the relief which forms the safety valve which prevents abnormal rise of supply pressure with the accumulator 7 to the supply pressure pipe path 36. The valve 14 and the pressure switch 15 forming the pressure monitoring means are connected. The upstream end of the pipe 41 provided through the leaking means 16 is connected to the supply pressure pipe 36, and the downstream end of the pipe 41 is connected to the low pressure side (reservoir 10). The output end of the pressure switch 15 is connected to the pump control means 17, and the pump control means 17 issues a command to the motor 18 according to the output signal of the pressure switch 15 to start the pump 5 and Configured to stop. That is, the high pressure working fluid pressurized and discharged by the pump 5 is accumulated in the reservoir 7, but on one side, the working fluid of the accumulator 7 gradually passes to the low pressure side (reservoir 10) through the leaking means 16. After the pump stops, the supply pressure gradually decreases. The supply pressure of the working fluid is monitored by the pressure switch 15 and when the supply pressure reaches a predetermined lower limit value, the pressure switch 15 outputs a signal informing it to the pump control means 17. The pump control means 17 which received this signal gives the motor 18 a start command, starts the pump 5, and starts a boost. When the accumulated pressure of the accumulator 7 increases and the supply pressure reaches a predetermined lower limit value, the pump control means 17 which receives the signal of the effect from the pressure switch 15 at this time gives the motor 18 a stop command. The pump 5 is stopped and the boosting is finished.

As shown in FIG. 3, the leaking means 16 has a taper pin 22 for fitting with a distance-shaped gap 21 between the first member 20 having the tapered hole 19 and the tapered hole 19. As shown in FIG. ) Is constructed by popping a second member (23) having one end and a nut (25) for fixing both. The second member 23 is a cylindrical portion connected to the bearing cylindrical portion 22A and the bearing cylindrical portion 22A coaxially connected to the taper pin 22 and the large diameter end of the tapered pin 22 with the same axis. And a coupling part 24 which is coaxially connected to the 26 and the cylindrical part 26 and which has a male screw having a larger diameter than the cylindrical part 26. The first member 20 has a hollow cylindrical shape and is connected to the tapered hole 19 and the large diameter end of the tapered hole 19 at one end thereof in order, and has a cylindrical recess 20A having a diameter larger than the diameter of the large diameter end. A bearing 20B having an inner diameter smaller than the inner diameter of the recess 20A adjacent to the recess 20A, and a cylindrical recess having a diameter larger than the inner diameter of the bearing 20B adjacent to the bearing 20B ( 20C), the engaging portion 20D of the inner diameter adjacent to the recessed portion 20C and smaller than the inner diameter of the recessed portion 20C is disposed on the same axis, and the engaging portion 20D is screwed with the male screw of the engaging portion 24. A male screw is provided.

The bearing cylindrical portion 22A of the second member 23 is fitted to the bearing portion 20B0, the coupling portion 24 is screwed onto the first member 20 at the coupling portion 20D, and the second member 23 is fixed to the first member 20 by a nut 25. The taper of the taper hole 19 and the taper pin 22 is formed to taper as it moves away from the engaging portion 24. The annular gap 21 between both the tapered holes 19 and the tapered pins 22 forms a throttle flow path (hereinafter also referred to as a throttle) for the flow of the working fluid, and the annular gap 21 The small diameter side is connected to the supply pressure pipe 36 (that is, the upstream side), and the large diameter side is respectively connected to the low pressure side (storage 10) via the recessed part 20A. ) Constitutes a feed screw mechanism, and by rotating the second member 23, the second member 23 is displaced in the axial direction with respect to the first member 20 so that the annular gap 21 is defined. After adjusting to the size, it is fixed by the nut 25 and integrally engaged.When integrally engaged, the tapered pin 22 is kept concentric with the tapered hole 19 and the annular clearance 21 is all around. It has become a uniform gap over.

In addition, a seal 27 is provided at the portion where the bearing cylindrical portion 22A of the second member 23 is fitted to the bearing portion 20B, and the working fluid is coupled from the recessed portion 20A through the recessed portion 20C. The leakage to the part 24 side is prevented. The cylindrical portion 26 between the bearing cylindrical portion 22A and the engaging portion 24 of the second member 23 is made of a material having a larger coefficient of thermal expansion than the first member 20. The other parts of the second member 23 and the first member 20 have the same thermal expansion coefficient.

As shown in Fig. 4, the initial temperature (the temperature of the member and the temperature of the member may be considered as the ambient temperature because it changes depending on the ambient temperature. The same applies hereinafter) The radius of the annular gap 21 in To When the magnitude of the direction (exactly the size of the gap measured perpendicularly to the tapered surface) is δo, when the temperature rises to T _H , the cylindrical portion 26 of the second member 23 is the first member 20. The taper pin 22 moves to the right in the axial direction in the drawing so that the gap decreases to δ _H , and conversely, when the temperature drops to T _L , the cylindrical portion 26 causes the first member 20 to extend larger than its corresponding portion. Since the taper pin 22 moves to the left in the axial direction, the gap increases to δ _L. When the coefficient of thermal expansion of the first member 20 is α1, the coefficient of thermal expansion of the cylindrical portion 26 is α2, the length of the cylindrical portion 26 is S, and the angle of the taper is θ, the temperature changes by ΔT. The gap δ at the time of becoming high becomes small when it becomes high temperature as shown by Formula 2, and becomes large when it becomes low temperature. The viscosity μ of the working fluid decreases as the temperature increases and increases as the temperature decreases, so that the viscosity μ and the gap δ of the working fluid change in proportion to the temperature change (if one increases, the other increases and the decrease decreases the other). Decreases).

[Equation 2]

However, since the holes and pins constituting the throttle contacting the high-pressure working fluid are usually made of the same material by using steel or copper alloy, the taper-shaped annular gap and the holes and pins due to temperature change are used. Since the dimensional change (change in diameter) of is equal to both, the gap δ hardly changes and can be regarded as always constant. In addition, the axial length of the throttle becomes longer at high temperatures and shorter at low temperatures, so that the change in viscosity μ of the working fluid is negated from the viewpoint of leakage, but the change is too small compared to viscosity μ, thus suppressing the change in leakage. The effect until doing is not obtained.

The change in temperature of the hydraulic viscosity ν (ν = μ / ρ, ρ is the viscosity) of the hydraulic fluid is well represented in Walter's empirical formula represented by Equation 3, and the viscosity becomes higher as the temperature gets higher. Increases.

[Equation 3]

For this reason, as shown in FIG. 5, when the taper-shaped annular gap is used, the leakage amount increases significantly at high temperatures.

Therefore, when using a cyclic gap having a taper as in the present embodiment, as shown in Equation 2, the value of the gap δ of the molecule in Equation 1 is changed to be equal to the value of the viscosity μ of the denominator according to the temperature change. In addition, since the leakage amount Q _L is proportional to the square of the gap δ, the change in the leakage amount can be suppressed to be small. In the temperature To, the diameter d of the fin, the length L in the axial direction of the annular gap, and the gap δ are set to be the same so that the annular gap without the taper and the annular gap with the taper have the same leakage amount at the temperature To. Temperature To lower temperature the so larger than the third power of the annular gap δ of 3 wins annular gap δ taper does not have having a taper of the annular clearance δ having a tapered leakage Q _L is increased and the the hot taper than the temperature T _O Since the third power of the annular gap δ having a taper becomes smaller than the third power of the cyclic gap δ without taper, the leakage amount Q _L of the tapered annular gap δ is reduced. As a result, the temperature T _L to T _H range is changed as shown in FIG. 5, and the tapered annular gap is less likely to suppress the variation in leakage amount than the annular gap without taper over a wide temperature range. Can be.

Therefore, according to this embodiment, even if the temperature varies greatly from summer to winter, there is little variation in the flow rate of the working fluid flowing through the leaking means 16, and less variation in the time required for the supply pressure to fall from the upper limit to the lower limit. For this reason, the fluctuation | variation of the operation frequency of a pump and operation time for maintaining supply pressure in a predetermined range can be suppressed small. In addition, it is possible to realize stable performance with the same specification from a warm area to a cold area, and there is no need to provide a special specification or change the size of the gap according to the installation location.

In addition, as an example of a combination of industrially useful materials, the first member 20 with high pressure acting therein is made of iron or steel, and the cylindrical portion 26 of the second member 23 is approximately twice as large as iron or steel. It is good to use aluminum which has a thermal expansion coefficient of. Alternatively, the cylindrical portion 26 may be made of a resin having a larger coefficient of thermal expansion. The larger the difference between the thermal expansion coefficients of the first member 20 and the cylindrical portion 26 is, the better. Because the length S in the axial direction of the cylindrical portion 26 may be small, the size of the leaking means 16 can be made small, and the angle θ of the taper can be made small, so that the gap δo before fixing the coupling portion 24. This is because the effect of reducing the error of the gap with respect to the screw feed at the time of adjustment is obtained.

In addition, the taper of the annular gap forming the throttle of this embodiment tended to increase in diameter from the supply pressure side toward the low pressure side. However, in this configuration, the cross-sectional area of the flow passage gradually increases, so that the sealing or foreign matter is aggregated. As a result, clogging due to accumulation and the like hardly occurs, stable performance is obtained for a long time.

Next, one embodiment of the channel opening and closing means of the present invention will be described with reference to FIGS.

In the present embodiment, the flow path opening and closing means 28 is provided upstream of the annular clearance 21 forming the throttle of the leaking means 16 shown in Figs. The flow path opening and closing means 28 has a valve case 30 having a valve seat 30A and a valve chain poppet 29 which is embedded in the valve case 30 and contacts / isolated with the valve seat 30A to open and close the flow path. Poppet valve configured to include is provided.

The valve case 30 is connected to an open end of a cylindrical hollow 30D having one end closed at a diameter d _A and an open end of the hollow 30D, and has a diameter do formed on the same axis as the hollow 30D. Cylindrical void 30E, which is _A <do, is connected to the void 30E to a cylindrical void 30F having a diameter dc formed on the same axis as the void 30E, but do <dc, 30F. It is provided with the cylindrical hollow 30G of diameter d _B (but do <d _B <dc) formed in the same axis adjacent to the hollow 30F, and the edge part on the opposite side to the hollow 30F of the hollow 30G is closed. It is. Vac 30D is an inlet 30H that communicates with reservoir 10, Vac 3E is an inlet 30B that communicates with supply pressure line 36 via a pipe 41, and VF 30F is the above. The outlet 30C connected to the small diameter end (upstream end) of the annular clearance 21 is provided with the discharge port 30J which communicates with the reservoir 10, respectively. The valve seat 30A forms a corner portion having a diameter approximately equal to do formed in the place where the space 30E is connected to the space 30F.

The poppet 29 is formed on the same axis in combination with the first cylindrical portion 31 and the first cylindrical portion 31 slidably fitted in the hollow 30D, and has an intermediate shaft smaller in diameter than the first cylindrical portion 31. (31A) and in combination with the intermediate side (31A) are formed on the same axis and combined with the valve seat cylindrical portion (32A) having a diameter d _D (where do <d _D <dc) and the valve seat cylindrical portion (32A) A second cylindrical portion 32 having a diameter of about dc and slidably fitted to the hollow 30G, a seal groove 31B formed in an annular shape on the outer circumference of the first cylindrical portion 31, and a second cylindrical portion. It is comprised including the thread groove 32B formed in the annular shape in the outer periphery of (32). The intermediate end 31A side end portion of the valve seat cylindrical portion 32A forms a cone having the intermediate shaft 31A side as the small diameter end (diameter <do), and this cone surface is contacted / isolated with the valve seat 30A to operate. It is adapted to close and open the flow path of the fluid.

This poppet valve is a flow path opening / closing part connected upstream to the supply pressure side and downstream to the upstream side of the annular clearance 21 of the leaking means 16, and the poppet 29 moves to the opening 30G side and opens. It is a poppet valve with an extended flow flowing from the upstream to the downstream side. In addition, the back spaces 30D and 30G seen from the valve seat 30A of the first cylindrical portion 31 and the second cylindrical portion 32 of the poppet 29 have discharge ports 30H and 30J. It is connected to the low pressure side (storage 10) via. Moreover, the compression spring 33 which comprises a closed operation mechanism is provided in the space 30G behind the 2nd cylindrical part 32, and the closed operation force Fc of the direction which closes a valve is made to the poppet 29.

According to the above constitution, when the supply pressure is within a predetermined range, the poppet valve forming the flow path opening and closing portion as shown in FIG. 6 is sufficiently opened to supply the upstream side of the annular gap 21 of the leaking means 16. Pressure is working. However, when there is any unreasonable occurrence such as the pump cannot start or the pump is started but the efficiency is lowered and cannot be boosted well, the supply pressure drops below the predetermined lower limit, as shown in FIG. The closed operation force Fc of (33) closes the poppet valve to cut off the supply to the leaking means 16 and prevent the supply pressure from continuing to fall.

The relationship between the remodeling force and the closing operation force acting on the poppet 29 of the present embodiment is configured as shown in FIG.

First, the case where the fluid pressure drive device is started while not accumulating completely on the accumulator 7 is considered. In this state, the poppet 29 is attached to the valve seat 30A by the closing operation force Fc ₁ of the spring 33, and the poppet valve which forms a flow opening / closing part is closed and is in the same state as FIG. When the operation of the pump 5 starts and the supply pressure p _S starts to rise, the poppet 29 has a downward force (the same in the drawing below) due to the pressure acting on the inside of the valve seat 30A having a diameter do. By the difference in the upward force due to the pressure acting on the first cylindrical portion 31 of d _A , the remodeling force Fo ₁ represented by Equation 4 acts downward.

[Equation 4]

If the supply pressure p _S continues to rise and exceeds po, the retrofitting force Fo ₁ becomes larger than the retrofitting force Fc ₁ , so that the poppet 29 moves away from the valve seat 30A and the poppet valve starts to open. On the downstream side, there is a throttle of the leaking means 16 having a large resistance to flow, so the pressure on the downstream side (vacation 30F) also rises immediately, and the poppet 29 has a second cylindrical portion (a) in the valve seat 30A of diameter do ( A downward force is also exerted by the pressure acting on the portion up to the diameter d _B of 32). Then, the increase in the closing operation force Fc of the spring 33 along with the opening is quickly overcome, and the pressure on the downstream side becomes equal to the supply pressure p _S, and the poppet 29 has an even larger retrofitting force represented by the equation (5). Fo ₂ is brought into action and is in the same open state as in FIG.

When the upper limit p _H of the supply pressure p _S is reached, the pump 5 stops to complete the boosting. At this time, the remodeling force is indicated by the point 52. Thereafter, when the supply pressure p _S gradually decreases due to leakage from the leaking means 16 and reaches the lower limit p _L , the pump 5 is started again to resume the boosting pressure, but the supply pressure p _S reaches the lower limit p _L. The poppet valve remains open even when the modulating force Fo ₂ is set to be larger than the closed operation force Fc ₂ even when the valve is opened. Therefore, in the normal state in which the supply pressure p _S is maintained between the upper limit p _H and the lower limit p _L by the start and stop of the pump according to the signal of the pressure switch, the retrofitting force is in the range of the thick line 51 of FIG. The poppet valve forming the flow path opening and closing portion is always kept open as shown in FIG.

In the following, if the pump cannot start or the efficiency of the pump decreases, or if there is any unreasonable occurrence such that the pump cannot be boosted well, or the throttle of the leaking means is damaged and the leakage amount increases significantly, _S p is undesirably out of the range of the heavy line 51 during the eighth falls below the lower limit value _L p. However, when the retrofitting force Fo ₂ becomes smaller than the closed operation force Fc ₂ and the poppet valve starts to close, the resistance to flow gradually increases, so that the pressure acting on the downstream downstream side of the valve seat 30A of diameter do is lost. Is close to Fo ₁ along the solid line 53, and when the supply pressure p _S reaches p _C , the poppet 29 is attached to the valve seat 30A to close the poppet valve forming the flow path opening and closing part. This pressure p _C is configured to be higher than the minimum supply pressure pmin necessary to perform normal operation as the fluid pressure drive of the breaker.

Therefore, according to the flow path opening and closing means, when the supply pressure drops to a predetermined pressure p _C , the flow path of the working fluid to the leaking means 16 is closed, and the leakage of the working fluid from the accumulator 7 to the reservoir 10 is stopped. As a result, the drop in the supply pressure p _S can be stopped at p _C so that the breaker cannot be driven.

As described above, according to the fluid pressure drive device according to the present invention, not only can the fluctuation caused by the operating frequency of the pump or the temperature of the operating time for maintaining the supply pressure within a predetermined range be reduced, but also by the pump If the supply pressure falls below the preset pressure, for example, when the boosting pressure cannot be normalized, the flow path opening and closing part is closed to stop the leakage from the leaking means and secure the minimum supply pressure necessary for normal operation. The operation can be performed to achieve high reliability.

In addition, as shown in FIG. 9, a communication hole for communicating an external space with the first member 20 of the leaking means 16 and a space containing the second member 23 (concave portion 20C) ( 34) may be provided. In this configuration, since the temperature difference is hardly generated between the cylindrical portion 26 of the first member 20 and the second member 23, the tracking of the gap δ of the throttle with respect to the external temperature change is faster. More precise.

As shown in FIG. 10, the leaking means 16 is formed of a material having a smaller coefficient of thermal expansion than that of the second member 23 in a part of the first member 20 (the part constituting the recessed portion 20C). It is good also as a structure which provides the cylindrical part 35. Alternatively, the cylindrical portion 26 having the large thermal expansion coefficient of the embodiments shown in FIGS. 3 to 5 and the cylindrical portion 35 having the small thermal expansion coefficient of FIG. 10 may be used in combination.

On the other hand, as shown in FIG. 11, the flow path opening and closing means 28 may be made to open the rear side of the valve seat 30A of the first cylindrical portion 31 and the second cylindrical portion 32 to the atmospheric pressure side. The spring 33 constituting the closed operation mechanism may be provided on the first cylindrical portion 31 side. The spring 33 can freely adjust the load by adjusting the engagement between the screw 31A and the nut 31B.

In the above embodiment, the closing operation mechanism of the flow path opening and closing means is a spring 33, but a mechanism using another elastic member, a fluid pressure pilot operation mechanism, or the like may be used. Even if it consists of these, the effect similar to the Example mentioned above can be acquired. Also, as shown in FIG. 12, the closing operation of the flow path opening and closing means under the condition that the pressure p _C when the retrofitting force Fo ₂ becomes equal to the closing operation force Fc ₁ in the closed state is smaller than the lower limit p _L of the supply pressure. the pressure may be higher than the lower limit value _L p of the supply pressure when the start. In such a configuration, since the flow path opening and closing means closes as many times as the pump, the valve body tends to be stuck because it has been stopped for a long time, so that it is impossible to operate correctly when necessary, and the supply pressure may be lower than the pressure p _C. Disappear.

In the above embodiment, the taper hole 19 and the taper pin 22 are used as the throttle flow path of the leaking means 16 as an example. However, instead of the taper hole, ordinary parallel holes (diameters do not change) are described. Hole) and a tapered pin is inserted concentrically into this hole to form a throttle flow path. However, the diameter of the large diameter end of the tapered pin 22 should be made larger than the diameter of a hole, and the vertical diameter end shall always be in a hole, and the large diameter end should always be outside a hole. Also in this case, the flow path cross-sectional area can be changed by the relative movement of the hole and the tapered pin 22 in the axial direction, and the flow rate change due to the change in the viscosity of the working fluid can be suppressed.

As described above, according to the present invention, even if the viscosity of the hot working fluid changes due to the change of the ambient temperature, the flow path cross-sectional area of the throttle portion of the leaking means also changes in the same way as the change of the viscosity of the working fluid, so that the variation in the leakage amount is reduced. In order to keep the pressure within a predetermined range, it is possible to reduce the operation frequency of the pump and the fluctuation of the operation time small, and if the pressure rise by the pump cannot be normal, the leakage of the working fluid is stopped and the supply pressure is reduced. Since it does not fall more than this, it becomes possible to reliably perform a predetermined | prescribed operation, and can implement the fluid pressure drive device and the circuit breaker of a reliable circuit breaker with high reliability.

Claims (17)

A reservoir containing a working fluid; A pump for pressurizing the working fluid and discharging it to a supply line; An accumulator connected to the supply-side pipeline and accumulating the working fluid pressurized by the pump; A fluid pressure cylinder for opening and closing a contactor of the breaker; Working fluid flow path control means provided through a conduit connecting the fluid pressure cylinder and the supply side pipe line and controlling supply and discharge of the working fluid to the fluid pressure cylinder; Pressure monitoring means for detecting and outputting a supply pressure which is a pressure of a working fluid accumulated in the accumulator; Leaking means for leaking the working fluid accumulated in the accumulator to the reservoir; A fluid pressure drive device for a circuit breaker having a pump control means operable to start and stop the pump in accordance with an output signal from the pressure monitoring means to maintain the supply pressure between a predetermined upper limit value and a lower limit value. The fluid pressure drive device of the circuit breaker characterized in that the passage cross-sectional area is reduced to increase when the ambient temperature rises and increases when the ambient temperature decreases. 2. The apparatus of claim 1, wherein the leaking means has a first member and a second member coupled to each other at one end, and the first member and the second member are disposed between the first member and the second member at the other end. And a throttle flow path through which the working fluid flows, one end of the throttle flow path is connected to the supply pressure side, and the other end is connected to the low pressure side, and at least a part of at least one of the first member and the second member is throttled. A fluid pressure drive device for a circuit breaker, characterized in that the flow path cross-sectional area of the flow path is made of a material different from the other member and the thermal expansion coefficient so as to decrease when the ambient temperature rises and increase when the ambient temperature drops. The throttle flow path according to claim 2, wherein the first member has a tapered hole, and the second member forms the throttle flow path through which a working fluid flows between one end of the first member and the other end of the taper hole. A fluid pressure drive device for a circuit breaker, having a taper pin that forms a gap and fits into the taper hole, and the coefficient of thermal expansion of the first member is smaller than that of the second member. 4. The fluid pressure drive device for a circuit breaker according to claim 3, wherein the tapered hole of the first member has a small diameter portion connected to a supply pressure side and a large diameter portion thereof connected to a low pressure side. The fluid pressure drive device according to claim 3, wherein the first member and the second member are relatively freely coupled with each other. 4. The fluid of a circuit breaker according to claim 3, wherein the first member includes a communication hole for enclosing the second member and for communicating an outer space of the first member and an inner space of the second member. Pressure drive. The flow path opening and closing means according to any one of claims 1 to 6, wherein a flow path opening and closing means is provided on the upstream side of the leaking means so as to close the supply path of the working fluid to the leaking means when the supply pressure becomes lower than or equal to a predetermined lower limit. Fluid pressure drive device of circuit breaker. 8. The flow channel opening and closing means according to claim 7, wherein the flow path opening and closing means includes a flow path opening and closing portion, one end of which is connected to the supply pressure side, and the other end of which is connected to an upstream side of the leakage means, and a remodeling mechanism and an elastic member for generating a force for opening the flow path opening and closing portion. And a closing operation mechanism for generating a force for closing the flow path opening and closing portion, and when the supply pressure falls below a predetermined lower limit value, the remodeling force of the retrofit operation mechanism is configured to be smaller than the closing operation force of the closed operation mechanism. A fluid pressure drive device for a circuit breaker. 9. The circuit breaker according to claim 8, wherein the flow path opening and closing portion is opened at a pressure higher than the lower limit of the supply pressure and lower than the upper limit of the supply pressure, and closed at a pressure lower than the pressure when the flow opening and closing portion is opened. Fluid pressure drive. The fluid pressure drive device according to claim 9, wherein the flow path opening and closing means is a poppet valve. The poppet valve according to claim 10, wherein the poppet valve is a poppet valve of an expansion flow flowing from the upstream side to the downstream side when the poppet valve opens, and the valve body of the poppet valve is smaller in diameter than the diameter of the valve seat of the poppet valve upstream. A first cylinder portion whose rear side is connected to the low pressure side or the atmospheric pressure side and a second cylinder portion whose diameter is larger than the diameter of the valve seat on the downstream side and whose rear side is connected to the low pressure side or the atmospheric pressure side, And a mechanism for generating a force for opening the poppet valve by a difference between a force acting on the first cylinder portion and a force in an opposite direction acting on the second cylinder portion. 9. The fluid pressure drive device of a circuit breaker according to claim 8, wherein said closed operation mechanism is a spring mechanism of which load control is free. The fluid pressure drive device according to claim 8, wherein the supply pressure when the flow path opening and closing part is closed is set to a pressure lower than a lower limit of the supply pressure at which the pump is started. The pressure when the remodeling force in the open state of the flow path opening and closing portion is equal to the closing operation force in the closed state is less than the lower limit of the supply pressure, and the supply pressure when the flow path opening and closing portion closes is the pump. And a pressure higher than the lower limit of the supply pressure at which the gas is started. A reservoir containing a working fluid; A pump for pressurizing the working fluid and discharging it to a supply line; An accumulator connected to the supply-side pipeline and accumulating the working fluid pressurized by the pump; A fluid pressure cylinder for opening and closing a contactor of the breaker; Working fluid flow path control means provided through a conduit connecting the fluid pressure cylinder and the supply side pipe line and controlling supply and discharge of the working fluid to the fluid pressure cylinder; Pressure monitoring means for detecting and outputting a supply pressure which is a pressure of a working fluid accumulated in the accumulator; Leaking means for leaking the working fluid accumulated in the accumulator to the reservoir; In the control method of a fluid pressure drive device of a circuit breaker having a pump control means operable to start and stop the pump in accordance with an output signal from the pressure monitoring means and to maintain the supply pressure between a predetermined upper limit value and a lower limit value. And controlling the flow path cross-sectional area of the leaking means to decrease when the ambient temperature rises and to increase when the ambient temperature falls. 16. The method of controlling a fluid pressure drive device for a circuit breaker according to claim 15, wherein the working fluid stops flowing to the leaking means when the supply pressure drops below a predetermined pressure. A reservoir containing a working fluid; A pump for pressurizing the working fluid and discharging it to a supply line; An accumulator connected to the supply-side pipeline and accumulating the working fluid pressurized by the pump; A fluid pressure cylinder for opening and closing a contactor of the breaker; Working fluid flow path control means provided through a conduit connecting the fluid pressure cylinder and the supply side pipe line and controlling supply and discharge of the working fluid to the fluid pressure cylinder; Pressure monitoring means for detecting and outputting a supply pressure which is a pressure of a working fluid accumulated in the accumulator; Leaking means for leaking the working fluid accumulated in the accumulator to the reservoir; A pump control means operable to start and stop the pump in accordance with an output signal from the pressure monitoring means to maintain the supply pressure between a predetermined upper limit value and a lower limit value; And is opened and closed by a fluid pressure drive configured to decrease when the temperature decreases and increases when the ambient temperature drops.

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