JPH0436318B2 - - Google Patents

Description

[Detailed description of the invention] [Object of the invention] Industrial application field The present invention is a method for automatically equalizing the pressure on the discharge side and the suction side of a compressor when the compressor is stopped in a refrigerator, an air conditioner, etc. This invention relates to a dynamic pressure valve for a refrigeration circuit that operates as follows.

Conventional technology When starting and stopping a compressor in a refrigeration circuit, the pressure on the discharge side remains high immediately after stopping operation, and if you try to operate the compressor in this state, it will overload and damage the machine. Therefore, it is usually necessary to wait two to three minutes before restarting the compressor until the differential pressure between the discharge side and the suction side of the compressor is resolved.

In order to shorten this waiting time, conventionally, a solenoid valve or the like is installed in the pressure equalizing pipe connecting the discharge side and suction side of the compressor, and the solenoid valve is linked to start and stop of the compressor to open and close the pressure equalizing pipe. However, when the compressor is stopped, the high pressure on the discharge side is immediately reduced to reduce the load when restarting the compressor.

However, the above technique has the disadvantage that a power source is required to drive the solenoid valve.

Problems to be Solved The present invention aims to eliminate the above-mentioned drawbacks, and to automatically equalize the pressure in response to the dynamic pressure of the compressor in the refrigeration circuit so that the pressure can be quickly equalized. The present invention aims to provide a large-capacity valve that opens and closes automatically and automatically equalizes the pressure on the discharge side and suction side when the compressor is stopped.

Means for Solving Problems The pressure dynamic valve of the present invention to achieve the above object operates by controlling a slight pressure difference when refrigerant flowing from the discharge side of the compressor passes through a fluid restrictor in the valve. By opening and closing a pilot valve mounted on a plate, the direction of fluid pressure acting on the piston-type main valve body is changed, and as a result, a large diameter pressure equalizing pipe can be opened and closed at once.

That is, the pilot type pressure dynamic valve of the present invention includes a cylindrical main valve body having a main valve seat at the bottom that follows the pressure equalization pipe side outlet, an inlet at the top surrounding the main valve body, and a mainstream outlet at the bottom. a valve case that divides the inside of the valve case into an inflow side chamber and an outflow side chamber, is formed with a constriction portion for fluid from the inflow side chamber to a side outflow side chamber, and is movable in the axial direction of the main valve body. an actuating plate; and an actuating plate, which is slidably provided in the axial direction so as to divide the internal space of the main valve body into a main valve chamber communicating with the outflow side chamber and a pilot chamber, and is positioned in an axial position from the pilot chamber side to the main valve seat side. a piston-shaped main valve body formed with a fluid passage communicating with the main valve body; and a piston-shaped main valve body that can slide in the axial direction through the upper wall of the pilot chamber, the upper end of which is in contact with the outflow side of the actuating plate, and the lower end of which is in contact with the main valve body. A pilot valve body capable of opening and closing a fluid passage of the main valve body, and a spring that biases the actuating plate in the valve opening direction through the pilot valve body, so that the pressure in the main valve chamber acts on the bottom surface of the main valve body. It is constructed.

Embodiment FIG. 1 shows an example of a pilot type pressure dynamic valve of the present invention. 1 is an inlet 2 that communicates with the discharge side of the compressor
The valve box has a main stream outlet 3 communicating with the condenser and a pressure equalizing pipe side outlet 4 communicating with the suction side of the compressor, and is constructed by assembling a main body part 1a and a lid part 1b. Reference numeral 5 denotes an actuating plate that divides the space inside the valve case into an inflow side chamber 2a and an outflow side chamber 3a, and is provided with a fluid restricting portion 5a. The operating plate 5 has a peripheral edge that can freely move along the inner surface of the valve case.

Reference numeral 6 denotes a main valve main body provided on the bottom surface of the valve case 1. The main valve seat 6a that constitutes the main valve A that opens and closes the pressure equalization pipe side outlet 4 is provided on the bottom surface, and the main valve chamber is provided on the side of the bottom. 7 and the outflow side chamber 3a is provided, and a cylindrical portion 6c is formed above to accommodate a piston-shaped main valve body 8 in a freely movable manner. Further, a pilot valve body 9 is provided at the open end of the cylindrical portion 6c.
A pilot valve guide 10 for holding the main valve body movably along the axis of the valve is attached, and a pilot chamber 11 is formed between the pilot valve guide 10 and the main valve body 8.

The pilot valve body 9 is provided so that its upper end is in contact with the outlet side of the actuating plate 5, that is, the lower surface in the figure, and is urged by a spring 12 so as to be pressed toward the actuating plate 5. Therefore, the actuating plate 5 is also constantly pushed toward the inlet 2.

A fluid passage 8a connecting the outflow port 4 and the pilot chamber 11 is provided at the axial position of the main valve body 8, and its opening on the pilot chamber 11 side is connected to the pilot valve seat 8.
b. Further, a needle 9a, for example, is formed at the tip of the pilot valve body 9, and together with a pilot valve seat 8b, a pilot valve B is constituted. The outer periphery of the main valve body 8 is made of wear-resistant material such as metal, and the center part is made of elastic material such as synthetic resin, so that both valves A and B are unlikely to leak. It's getting old.

The pilot type pressure dynamic valve of the present invention constructed in this manner is incorporated into a refrigeration circuit as shown in FIG. 2a, for example. Here, 20 is a hydraulic valve of the present invention, 2
1 is a compressor, 22 is an outdoor heat exchanger or condenser, 23 is an expansion valve, 24 is an indoor heat exchanger or evaporator, 26 is a discharge side pipe of the compressor, 27 is a condenser side pipe, and 28 is a This is a pressure equalizing pipe that connects to the suction side of the compressor.

Further, FIG. 2b shows a refrigeration circuit of a cooling/heating switching type air conditioner, which is the same as that shown in FIG. 2a except that 25 is a four-way valve for switching between an outdoor heat exchanger and an indoor heat exchanger.

In the pilot type pressure dynamic valve of the present invention, when refrigerant is supplied from the discharge port of the compressor to the inflow port 2, the refrigerant enters the outflow side chamber 3a from the inflow side chamber 2a through the fluid restriction section 5a, and is condensed from the main stream outlet 3. Head to vessel 22.
At this time, a pressure difference is generated before and after the fluid restricting portion 5a,
As a result of this differential pressure acting across the entire surface of the actuating plate 5, the pilot valve element 9 pressed by the actuating plate 5 compresses the spring 12 and pushes the main valve element 8 towards the main valve seat 6a.
It will be pushed towards. When pilot valve B and main valve A are closed one after another in this way,
The pressure in the outflow side chamber 3a is applied to the fluid in the pilot chamber 11 through the gap between the pilot valve body 9 and the pilot valve guide 10 and the gap between the main valve body 8 and the cylindrical portion 6c. is pilot room 1
Main valve seat 6 due to the difference between the pressure at
It will be strongly pressed against a. In this way, the pressure equalization pipe side outlet 4 is reliably closed, so that all the refrigerant flowing in from the inlet 2 flows out through the main stream outlet 3.

Next, when the operation of the compressor 21 is stopped, the flow of refrigerant immediately stops, and the differential pressure across the operating plate 5 is eliminated. Then, the operating plate 5 is pushed back together with the pilot valve body 9 by the spring 12, which had been compressed until then, and the pilot valve B opens, and the pressure in the pilot chamber 11 is reduced to the pressure in the pressure equalizing pipe 28, that is, the suction of the compressor 21. The side pressure drops immediately. As a result, the pressure in the main valve chamber 7 acting on the bottom of the main valve body 8 overcomes the pressure in the pilot chamber 11 and pushes up the main valve body 8, opening the main valve A and draining the refrigerant in the valve case. In addition, the refrigerant in the discharge side pipe 26 and the condenser side pipe 27 also flows out to the pressure equalization pipe 28, and the pressure in the refrigeration system is quickly equalized.

As described above, the pilot type pressure dynamic valve of the present invention is provided with the actuating plate 5 having a large pressure receiving area, and the actuating plate is supported by the relatively weak spring 12, so that the pilot type pressure dynamic valve of the present invention The pilot valve B is closed by the slight dynamic pressure difference, and the main valve A is reliably closed by the refrigerant discharge pressure itself. As soon as the flow of the refrigerant stops, the pilot valve B is opened, and the main valve A, which has a large flow diameter, opens due to the pressure difference of the refrigerant itself, and the pressure in the system is quickly equalized.

FIG. 3 shows changes in pressure on the discharge side and suction side when the compressor is started and stopped as described above. In FIG. 3, when the compressor starts operating at time O, the pressure equalizing pipe is immediately closed and normal operation begins. When the compressor stops operating at time A, if there is no pressure equalizing pipe, the pressure will gradually equalize like a curve, for example, in the case of a normal air conditioner,
3 minutes, on average it took 2 minutes and 20 seconds (A→C), whereas when the pilot type pressure dynamic valve of the present invention was used to equalize the pressure, the pressure was quickly equalized as shown in the curve, On average, about 20 seconds was sufficient (A→B).

Effects of the Invention The pilot type pressure dynamic valve of the present invention is configured to operate with a small dynamic pressure difference, so it has almost no effect on normal refrigeration circuit operation, and automatically automatically operates as soon as the operation stops. By instantly opening the large-diameter main valve through pilot operation, the differential pressure between the discharge side and the suction side of the compressor can be quickly equalized. Then, the functions previously fulfilled by the solenoid valve, the power supply for its drive, switches, and other parts are replaced with the essentially maintenance-free and compact hydraulic pressure valve of the present invention, thereby constructing a simple and streamlined refrigeration circuit. Now I can do it.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the structure of an example of a pilot type pressure dynamic valve according to the present invention, and Figs. This is a system diagram. FIG. 3 is a graph illustrating the operating state of the pilot type pressure dynamic valve of the present invention. 1... Valve box, 1a... Body part, 1b... Lid part,
2...Inflow port, 2a...Inflow side chamber, 3...Mainstream outlet, 3a...Outflow side chamber, 4...Pressure equalization pipe side outlet,
5... Actuation plate, 5a... Fluid restrictor, 6... Main valve body, 6a... Main valve seat, 6b... Opening, 6c...
...Cylindrical part, 7...Main valve chamber, 8...Main valve body, 8a...
...Fluid passage, 8b...Pilot valve seat, 9...Pilot valve body, 9a...Needle, 10...Valve guide, 11...Pilot chamber, 12...Spring, 20...Dynamic pressure valve, 21...Compression Machine, 22...
Condenser, 23... Expansion valve, 24... Evaporator, 25
... Four-way valve, 26 ... Discharge side pipe, 27 ... Condenser side pipe, 28 ... Pressure equalization pipe.

Claims (1)

[Claims] 1. A cylindrical main valve body that has a main valve seat at the bottom that follows the outlet on the pressure equalization pipe side, a valve box that surrounds the main valve body and has an inlet at the top and a mainstream outlet at the bottom, and a valve case inside the valve box. an actuating plate that is movable in the axial direction of the main valve body, the actuator plate being movable in the axial direction of the main valve body, the actuator plate being partitioned into an inflow side chamber and an outflow side chamber, and having a constriction portion for fluid flow from the inflow side chamber to the outflow side chamber; A piston-shaped piston-shaped valve that is slidable in the axial direction so as to divide the valve into a main valve chamber and a pilot chamber that communicate with the outflow side chamber, and has a fluid passage that communicates from the pilot chamber side to the main valve seat side at the axial position. a main valve body, and a pilot valve body that can slide in the axial direction through the upper wall of the pilot chamber, the upper end of which contacts the outflow side of the actuating plate, and the lower end of which can open and close the fluid passage of the main valve body. , a spring that biases the actuating plate in the valve opening direction via the pilot valve element, and is configured such that pressure within the main valve chamber acts on a bottom surface of the main valve element.