JPS59137676A - Expansion valve - Google Patents

Abstract

PURPOSE:To prevent a valve from any influence due to hysteresis, by installing permanent magnet and a solenoid coil between a pipe provided at the outside of a hollow shaft and installed so as to wrap both of a nozzle hole and a flow port and a closed end part of the shaft. CONSTITUTION:When a pulse signal is impressed on a solenoid coil 2, a plunger 3 moves up and down due to a relationship between electromagnetic force and resilient force of springs 25 and 26 whereby opening at an average time in a nozzle hole 18 of a hollow shaft 21 varies to some extent and the nozzle hole 18 will not come to its halfway opening so that there is no influence of hysteresis. The pulse signal is given to the coil 2 so as to cause it become the same direction as a line of magnetic force of a permanent magnet 29, and when a flow port 19 is opened by making a sucker 22 attract a plunger, a refrigerant flows into a pipe 24 from an opening part 27 with no flow resistance, while if the pulse signal is given to the coil 2 so as to cause it to become the opposite direction to the line of magnetic force of the permanent magnet 29, the flow port 19 is closed.

Description

[Detailed description of the invention] [Field of application of the invention] U room air conditioner and packaged air conditioner according to the present invention.

This invention relates to expansion valves used in the refrigeration cycle of car air conditioners, vehicle air conditioners, and heat pump air conditioners, and in particular provides an electromagnetic flow control expansion valve that controls the flow rate of refrigerant in proportion to an electrical input signal. .

[Prior art]

BACKGROUND ART Magnetic valves (ON-OFF valves) that use electromagnetic force to close a valve and stop the flow of fluid are conventionally known.

However, this JIIL magnetic valve (ON-OFF valve) does not have the function of continuously controlling the flow rate. Also,
There is also a method of controlling the flow rate by changing the electrical signal (current or voltage) input to the electromagnet and changing the area of the flow path.
However, this method is
As shown in Figure 2, there are many drawbacks such as large electrical hysteresis and errors in flow rate control, and the addition of a correction to compensate for this has the drawback of being expensive.

It is also used as a flow rate control valve for the refrigeration cycle of room air conditioners, etc.
There is a thermoelectric (bimetallic) expansion valve shown at 73.

This pulp converts electrical signals into thermal energy and controls the flow rate by changing the displacement of the bimetal in response to this thermal energy lid. However, this method is hot
The problem was that the response time was slow because words were converted into thermal energy.

A conventional ilt control valve will be explained below based on the drawings. The flow jti61J control valve shown in FIG. 1 is a conventional valve that utilizes electromagnetic force. This is provided in the control valve main body 1, and attracts the granger 3 against the spring 4 by the magnetic force generated by a single input signal to the electromagnetic coil 2, and the attraction force matches the spring force of the spring 3. Therefore, the plunger 3 is held at a position corresponding to the magnitude of the electrical input signal, and the valve flow formed by the valve body 5 attached to the plunger 3 and the valve seat 6 provided on the control valve body is adjusted. By arbitrarily changing the road area, the flow rate is continuously controlled in accordance with the magnitude of the electrical input signal. According to this control valve, the flow area of the valve formed by the valve body 5 with salt 9 attached to the plunger 3 and the valve seat 6 provided on the control valve body 1 is determined by the magnitude of the electrical input signal supplied to the electromagnetic coil 2. The flow rate can be controlled by changing it arbitrarily depending on the flow rate. However, the granger 3 made of ferromagnetic material has magnetic hysteresis H.
occurs5, so the input area pressure E is changed as shown in Figure 2.
The relationship between + and the plunger displacement amount t differs greatly between C when the input voltage E1 increases and B when the input terminal Ei decreases. That is, even if the input voltage Ei is the same, the plunger displacement amount will be as shown by Ll and t29, and the flow rate will be significantly different. When this type of flow control valve is put into practical use, it is necessary to add equipment for correcting and correcting this error, making it extremely expensive. Furthermore, when such a valve is used as a control valve of a heat pump air conditioner, it is used as an expansion valve. In this case, the valve body 5 and the valve seat 6
The flow path area that is formed tightly due to this becomes extremely infertile, and a large pressure difference occurs between the spaces 7 and 8 provided on both sides of the valve seat 6. When the flow direction is reversed during cooling and heating, as in a heat pump air conditioner, spaces 7 and 8
The pressure difference is not applied to the valve body 5, and the force is in the opposite direction. For this reason, the balance between the forces of the electromagnetic coil 2 and the spring 40 differs significantly between cooling and heating, making it difficult to control both heating and cooling using only one valve.

FIG. 3 is an example of a conventional thermoelectric (bimetallic) expansion valve. This is the electric signal given from the electric terminals 9 and 10.
2, converts it into heat) (deforms the metal), transfers this deformation amount to the valve body 5 via the spacer 13, and transfers it to the nozzle 14.
The amount of aperture is controlled. This valve converts the electric signal into heat to heat the bimetal, or the heated bimetal is cooled by natural heat dissipation of the fluid in the heated bimetal container 15, changing the amount of deformation of the bimetal.
-Response becomes slower due to conversion to metamorphosis. Furthermore, when used in the refrigeration cycle of a toto pump, when the refrigerant is flowed in the direction of the arrow in the figure during cooling, the high-pressure liquid refrigerant in the opening 16 passes through the nozzle 14 and becomes a low-pressure gas-liquid mixed refrigerant. It then flows to Sekiguchi section 17. At this time, low-pressure gas refrigerant enters the container 15 from the opening 16 and is controlled as described above. However, when the refrigerant is flowed in the opposite direction to the arrow in the figure, such as during heating, the opening 17 A high pressure liquid refrigerant is placed in container 1.
It will be in the top 5. In the case of C) All the heat that tries to heat the bimetal is taken away by the evaporation of the high-pressure liquid refrigerant, so the bimetal does not deform and cannot be controlled. As described above, this thermoelectric expansion valve has the disadvantages of slow response and lack of reversible flow.

Furthermore, when the valves shown in Figures 1 and 3 are used as expansion valves in refrigeration cycles, the cross-sectional area of the flow path provided in the valve seat 6 or nozzle 15 is made small so that the flow is restricted even when the valve is fully open. . This is because if the cross-sectional area of the flow path is made large enough to prevent the flow from being restricted, the stroke of the valve body 5.14 must be made thicker. This increases the cost, increases the electrical input, and causes disadvantages such as poor controllability.Therefore, when opening a general solenoid valve (ON-OFF valve) for such a control valve, Similarly, it was difficult to simultaneously provide the ability to flow fluid with almost no flow resistance.

[Object of the Invention] The present invention has been made based on the above-mentioned matters, and is a valve structure that is not affected by hysteresis, in which the signal form of the electrical input signal is devised, and the flow path area is arbitrarily changed. It is designed to continuously change the flow rate per unit time to obtain a desired flow rate, as well as to provide sufficient control even when the direction of the flow path changes, and is intended as a general solenoid valve (stop valve). be.

[Summary of the invention] This is used as an expansion valve for a refrigeration cycle.
In particular, as an expansion valve for a heat pump air conditioner, the valve structure has been improved to provide reversible flow, reducing the influence of refrigerant pressure acting on the valve body and improving the valve body's mobility. The driving method used was to apply a pulse-period electric signal to an external electromagnetic coil to periodically move the valve body to control the flow rate. In addition, a permanent magnet is incorporated into the drive part of the valve body,
By controlling the direction and magnitude of the magnetic force of the electromagnetic coil and permanent magnet, a conventional electromagnetic valve (ON-0/FF valve) can be used as a flow control valve.
This is an expansion valve that also has the same functions as the above.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 4 shows an example of an expansion valve according to the present invention. In the figure, the same reference numerals as in FIG. 1 indicate the same or equivalent parts.

The expansion valve according to the present invention has a nozzle port 18 and a flow port 1 on the side wall.
9 and has an opening 20 on one side, and an attractor 22 at the closed end opposite to the opening 20.
A pressure equalizing port 23 is provided between the suction element 22 and the opening 200.
A plunger 3 having an opening 27 is provided so as to be movable in the axial direction of the shaft 21 via a ring 25, 26, and a pipe 24 having an opening 27 is connected to a nozzle 018 and a flow port 1.
The permanent magnet 29 and the electromagnetic coil 2 are provided outside the shaft 21 and between the vibrator 24 and the closed end of the shaft 21.

In the expansion valve configured as described above, the plunger 3 moves up and down due to the balance between the electromagnetic force generated by the input cabling signal applied to the electromagnetic coil 2 and the force of the spring 25, 26, and the nozzle opening 18 of the shaft 21 is Operates to open or close.

In the present invention, for example, as shown in FIG. 5, the pulse signal is made such that the opening time or closing time of the nozzle opening 18 provided on the shaft 21 is constant, and the number of times, that is, the frequency, is variable. Also, as shown in Figure 6,
The pulse signal is one in which the frequency is constant and the opening time or closing time of the nozzle opening 18 provided on the shaft 21 is variable. The flow rate of the refrigerant can be controlled by moving the plunger 3 up and down using such a pulse signal and changing the opening degree of the nozzle port 18 on a time average basis. Therefore, the plunger 3 completely opens or closes the nozzle port 18 and moves up and down, so there is no need to control the plunger 3 to an intermediate opening of the nozzle port 18, unlike in conventional valves. The refrigerant flow rate is completely unaffected by the hysteresis that was a problem with the previous valve, and the flow rate of the refrigerant can be continuously changed in accordance with the pulse signal to obtain an arbitrary flow rate.

Furthermore, when the valve of the present invention is used in the expansion valve of a toto pump air conditioner, the flow direction of the refrigerant changes during cooling and heating.
The rotation pressure of plunger 3 also changes, but plunger 3
The pressure equalizing port 23 provided in the plunger 3. Since the pressure acting on the upper and lower surfaces can be balanced, the plunger 3 can be driven by almost the same pulse signal without being affected by the pressure. Regardless of whether the refrigerant is in a gas or liquid state that enters between the plunger 3 and the suction element 22, it does not convert an electrical signal into heat like a conventional bimetallic expansion valve, but instead uses an external electromagnetic force. Since the plunger 3 is directly driven, it is possible to easily provide reversible flow that can be controlled in both cooling and heating.

When performing these flow rate controls, the pulse signal input to the electromagnetic coil 2 has a variable frequency as shown in FIG. 5, and a constant frequency and ON time T i * T as shown in FIG.
In addition to the case where z-1OFF time t -'1'□ and 1-Tz are variable, by using a combination of these two, it is also possible to continuously change the flow rate per unit time and obtain an arbitrary flow rate. . Although this method requires somewhat complicated control, it has additional advantages such as linear flow rate control and the ability to further increase the flow rate and control over a wide range without increasing the size of the entire control valve. Further, in FIGS. 5 and 6, a unidirectional positive or negative pulse signal is used, but this pulse signal may be a combination of both positive and negative signals.

FIG. 7 shows experimental results according to the present invention. The horizontal axis indicates the frequency of the electric pulse applied to the electromagnetic coil 2,
The vertical axis represents the flow rate when the nozzle port 18 is fully opened, which is 100%.
The figure shows the flow rate side when . As is clear from the figure, the flow rate changes continuously according to the frequency, and there is almost no difference between the flow rates obtained when the frequency is increased and when the frequency is increased, and an arbitrary flow rate is obtained. Moreover, FIG. 7b shows a result of investigating the reversibility of the control valve of the fifth example. From this figure, it can be seen that even if the refrigerant flows in the direction A or the direction B, the flow rate can be sufficiently controlled in a one-to-one correspondence with the frequency.

Next, a method of flowing the refrigerant in the valve of the present invention with almost no flow resistance like when a solenoid valve (ON-OFF valve) is opened will be described. In this case, a higher voltage or a longer electric pulse of 08 hours than in the case of flow control is applied to the electromagnetic coil 2 so as to be in the same direction as the magnetic field lines of the permanent magnet 29, and the plunger 3 is caused to be attracted by the attractor 22. By opening the flow port 19, which is larger than the nozzle port 18, a larger amount of refrigerant can flow with almost no flow resistance. In this case, when the plunger 3 is attracted to the attractor 22, the electric signal pulse to the electromagnetic coil is turned OFF, and this state is maintained by the action of the permanent magnet, so that the conventional electromagnetic valve (ON-OFF valve) Compared to the fact that it is always energized when open or closed, the electrical input is very small. Also, when closing the distribution port 19, the distribution port 1
By applying an electric pulse to the electromagnetic coil 2 in the opposite direction to the direction of the magnetic field lines of the permanent magnet 29, the plunger 3 separates from the attractor 22 and the flow opening 19 is easily opened. can be closed.

Further, in the expansion valve of the embodiment shown in FIG. 4, the suction element 22,
The same operation can be performed even if the permanent magnet 29 is removed. That is, in this case, the conventional solenoid valve (O
As with the N-OFF valve, when opening the flow port 19, it is of course necessary to continue energizing, but if the current is continued, the plunger 3#'i is attracted and the flow port 19 is held in the open state.

Another embodiment FIG. 8 shows the nozzle opening 1 in the embodiment shown in FIG.
8 and the flow port 19 are combined into one flow port 19'. In this case, when using it as an expansion valve, the voltage of the electric nozzle signal to the electromagnetic coil 2 should be lower than that when the flow port 19' is fully opened, so that the sibling plunger 30 stroke can be adjusted to Ll in FIG. In this state, as in the previous embodiment, the frequency of the demon pulse signal or 0N-
Control the refrigerant flow rate by changing the OFF time. Flow port 19'
In order to fully open the plunger 3, it is preferable to increase the voltage of the electric pulse signal so that the no-lunger 30 stroke reaches L2 or more so that the plunger 3 is attracted to the attractor 22.

As a method of changing the stroke of the plunger 3, in addition to changing the voltage, it is also possible to change the stroke of the plunger 3 by lengthening the 08 hours of the pulse signal. Figure 10a.

10b and 10C show modified examples of the shape of the flow port 19'. In particular, the example shown in FIG. 10C makes it easier to control the refrigerant flow rate. Except for the flow port 19, it is dedicated to controlling the refrigerant flow rate, and +! Flow rate control method 4 The method is the same as in the previous embodiment.

〔Effect of the invention〕

As explained above, according to the expansion valve control method of the present invention, any desired flow rate can be obtained continuously according to the pulse signal input to the electromagnetic coil without the influence of hysteresis, and the flow rate can be controlled with high precision. It can be done with Furthermore, it has reversible flowability that allows the flow rate of the refrigerant to be easily controlled without being affected by the pressure of the refrigerant even if the direction in which the refrigerant flows changes.

Furthermore, like conventional solenoid valves (ON-OFF valves), refrigerant can flow with almost no passage resistance, and the only electrical input applied at this time is a pulse signal when operating the valve. After that, the position of the plunger is held by the permanent magnet, which has the effect of consuming almost no power.

[Brief explanation of the drawing]

Figure 1 is a diagram of a conventional control valve, Figure 2 is a diagram showing the relationship between input pressure and plunger displacement in the control valve of Figure 1, and Figure 3 is a thermoelectric expansion diagram of a conventional expansion valve. cross-sectional view of the valve,
4 to 7 are for explaining the present invention; FIG. 4 is a vertical cross-sectional view showing one embodiment of an expansion valve used in the present invention, and FIG. FIG. 6 is a diagram showing the waveform of the input pulse applied to the electromagnet of the expansion valve shown in FIG. 4. FIG. 5 is an example in which the frequency is variable, and FIG. Figures 7 and 7b, in which the opening time or closing time is variable, are diagrams showing experimental examples using the method of the present invention. Figures 8 to 11 are relationship diagrams showing changes in frequency and flow rate. This figure shows another embodiment of the present invention. 2...Tami coil 3...Plunger, 18...
Nozzle port, 19... Distribution port, 22... Suction element, 23
...Pressure equalization port, 25.26...Spring, 29...
·permanent magnet. Figure 1 Figure 2 Input? JL E' Stone 3 Figure 5 ￥ J l Figure 7. C-・,-period: Algae 0 Saime Kumo count Hz Takashi 5 7 Fig.

Claims (1)

[Claims] 1. A hollow shaft having a nozzle port and a flow port on the side wall and an opening on one side, and an attractor made of a magnetic material at the closed end on the opposite side of the opening. A plunger made of a magnetic material and having a pressure equalizing port inside is held between the opening in the shaft and the attractor so as to be movable in the axial direction of the shaft via springs at both ends. Connect the pipe to the nozzle port and the flow port externally, and
An expansion valve for a refrigerator, characterized in that a permanent magnet and an electromagnetic coil are provided outside the shaft and between the pipe and the closed end of the shaft. 2. The expansion valve according to claim 1, characterized in that it has a flow port that combines a nozzle port and a flow port into one. 3.11 A plunger made of a magnetic material and having an internal pressure equalization port is placed in a hollow shaft with a nozzle port on the wall and an opening on one side, with a spring interposed between the opening and the closed end. An expansion valve characterized in that a shaft is held so as to be movable in the axial direction, a pipe is connected to a nozzle port on the outside of the shaft, and an electromagnetic coil is further provided on the outside of the shaft.