JPS6280468A - Expansion valve for refrigeration cycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an expansion valve used in a refrigeration cycle for an air conditioner such as a room air conditioner, a package air conditioner, a car air conditioner, etc., and particularly an expansion valve suitable for a heat pump cycle. It is related to.

[Background of the invention]

Conventionally, as an electric expansion valve for refrigeration cycle,
As described in No. 8106369 and Japanese Patent Laid-Open No. 59-52359, there are those that use an electromagnet and those that use a step motor as a driving source. However, these expansion valves did not take into account the following points.

In the example using an electromagnet described in JP-A No. 58-106369, the operation from fully closing to fully opening the valve is quick, but since the orifice port is provided on the side wall of the valve body, even if the valve is fully opened, , it was difficult to completely close the orifice mouth. In addition, in the case of using a step motor described in JP-A No. 59-52359, it is possible to fully close the valve, but it takes time to fully close the valve, and the air conditioner must be turned off. When the valve was turned off, the valve opening remained at the operating state, and when the power was turned off, the valve body was unable to fully close the valve automatically and quickly.

[Purpose of the invention]

The present invention was invented in view of the above problems, and has the characteristic that the expansion valve acts quickly from fully closing to fully opening, and that the valve itself automatically tries to close the orifice even when the power is turned off. An object of the present invention is to provide an electric expansion valve having the following features.

[Summary of the Invention] In order to achieve the above object, the present invention provides an orifice inside the valve body, which was conventionally provided on the side wall of the valve body, and also provides orifices in two stages [2, - for fully closing orifices]. ,
The other one is used as an orifice for flow rate control to improve the valve's fully closing characteristics.

Embodiments of the present invention will be described below with reference to FIG.

The embodiment shown in FIG. 1 shows an example of an electric expansion valve. The expansion valve has a hollow shaft 1 having an opening All on one side, and a yoke 2 made of a magnetic material at the closed end opposite to the opening 11, and a movable magnetic core 3 made of a magnetic material inside the shaft 1. and a plunger 4 having a pressure equalizing hole 14 inside,
A spring 7.8 is disposed between a bearing-shaped support member 5 provided at an intermediate portion within the shaft 1 and a holding member 6 provided at the yoke portion so as to be movable in the axial direction within the shaft 1. There is.

The outer shape of the plunger 4 is such that the upper part 4a of the plunger is thick, the lower part 4b of the plunger is thin, and there is a tapered part 4 between the two.
C, and the valve body 4d at the tip of the plunger lower part 4b is made into a spherical shape with a diameter larger than that of the plunger lower part 4b. is provided at the position of the valve body 4d at the tip, and a pipe 10 is connected to the flow port 9 provided in the side wall of the shaft 1 to open it.

It has a structure in which a portion B12 is provided, and an electromagnetic coil 13 is further provided on the outside of the shaft 1 and on the closed end side of the shaft 1.

The electric expansion valve configured as above has an electromagnetic coil +3V
C When no electric signal is applied, the tip valve body 4 of the plunger 4
d closes the second orifice 16 and the valve is in a fully closed state, and when an electric signal is applied to the electromagnetic coil 13, the plunger 4 is pulled up according to the balance between the electromagnetic force generated by the electric signal and the force of the spring 7.8. As a result, the opening degree of the second orifice 16 is widened. At this time, the first orifice 15
The opening degree is gradually opened by the taper portion 40 of the plunger.

This controls the refrigerant flow rate through the first orifice 15.

The heat pump type air conditioner has a compressor 17, a four-way valve 18, an outdoor heat exchanger 19ζ1 [
F] It is composed of an expansion valve 20, an indoor heat exchanger 21, and piping connecting these. During cooling, the refrigerant flows in the direction of the solid arrow 22 in the figure to cool the room, and during heating, the four-way valve 18 is turned off. As a result, the refrigerant flows in the direction of the broken line arrow 23 in the figure, heating the room. Therefore, the flow direction of the refrigerant flowing through the expansion valve 20 is opposite during cooling and heating. Therefore, an expansion valve for a heat pump type air conditioner must have reversible flowability that allows the flow rate of the refrigerant to be controlled no matter which direction the refrigerant flows. Generally, since an expansion valve has a function of expanding refrigerant, there is a large pressure difference before and after the expansion valve. For this reason, the pressure acting on the movable part of the expansion valve may not be able to control the flow rate of refrigerant in either direction during cooling or heating. On the other hand, in this embodiment, the pressure equalization port 14 provided in the plunger 4 makes the force balance of the pressure acting on the movable part the same during cooling and heating, so that the plunger 4 can be moved easily and the expansion valve This makes it easy to control the flow rate.

Also, depending on the balance between load and capacity, air conditioners can reach 0N.
-OFF operation is performed well. In the ON state, there is high pressure refrigerant on the high pressure side, but in the OFF state, conventionally, the expansion valve does not close, so the refrigerant on the high pressure side flows into the low pressure side, and - due to the variable compressor 17. The refrigerant that has been pressurized does not do its job and the pressure drops. For this reason, energy loss increases during ON-OFF operation.

In some cases, an on-off valve is provided separately from the V'C expansion valve 20 to prevent this, but this is disadvantageous in terms of cost. Conventionally, electric expansion valves using step motors have no control (
There are some valves that can be fully closed by giving a signal, but the valve cannot be closed if the main power is directly turned off or if the power to the control circuit is cut off, such as during a power outage. There wasn't.

This expansion valve is designed to provide this function. This is provided with a second orifice 16 in addition to the first orifice 15 for flow rate control, and the second orifice is opened and closed by the plunger tip 4d. With this structure, when the refrigerator is stopped, the electromagnetic expansion valve can be automatically closed by turning off the electrical signal to the expansion valve. This operation turns off the electrical signal
Since the valve is automatically closed by doing this, the second orifice 16 is closed even in the event of a power outage or the like.

Further, in this expansion valve, the plunger 4 moves almost simultaneously with the input of an electric signal input to the electromagnetic coil 13 to open the second orifice 16, and it is possible to maintain the first orifice 15 at an opening degree according to the human power signal. therefore,
It is also possible to sufficiently respond to the valve response required for excessive barking such as when the compressor 18 of the refrigeration cycle is started.

〔Effect of the invention〕

As described above, according to the present invention, the expansion valve has reversible flowability, and the valve is automatically fully closed when no electricity is applied, and when the valve is changed from fully closed to fully open. It has the advantage of being able to open the circuit immediately when the electromagnetic coil is energized, and has extremely good responsiveness.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an expansion valve showing one embodiment of the present invention, and FIG.
The figure is an air conditioner power cycle system diagram. 1... Valve body 4... Plunge 14... Pressure equalization port 15... First orifice 16... Second orifice 4C... Taper part 4d... Valve body 11.
...Opening 9...Communication port.

Claims (4)

[Claims] 1. A hollow shaft having an opening at one end, a communication port in the middle, and a yoke made of a magnetic material at the other closed end;
Inside this shaft, a first orifice and a second orifice are formed at an appropriate distance between the opening and the flow port, and within the hollow shaft, movable magnetic cores made of a magnetic material are arranged concentrically. A plunger is inserted and supported so as to be movable in the axial direction, and this plunger has a valve body at its tip and a tapered part formed at an appropriate distance, the valve body is located in the second orifice to form an on-off valve, and the taper part is 1. An expansion valve for a refrigeration cycle, characterized in that a flow control valve is formed at a first orifice, and an electromagnetic coil is disposed around the outer periphery of a hollow shaft on the closed part side. 2. The expansion valve for a refrigeration cycle according to claim 1, wherein the valve body is a spherical valve. 3. The means for movably supporting the plunger in the axial direction includes:
The expansion valve for a refrigeration cycle according to claim 1, which is a spring interposed between a bearing-like support member and a spring provided inside the hollow shaft, and a yoke and a movable magnetic core. 4. The expansion valve for a refrigeration cycle according to claim 1, wherein the opening and the flow port are connected to piping between a condenser and an evaporator of the refrigeration cycle.