JP4077308B2 - Expansion valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an expansion valve constituting a refrigeration cycle.
[0002]
[Prior art]
Although there are various types of expansion valves, the valve body is arranged so as to face the orifice formed by narrowing the middle of the high-pressure refrigerant passage through which the high-pressure refrigerant sent to the evaporator passes, and evaporates. An expansion valve that opens and closes a valve body in accordance with the temperature and pressure of a low-pressure refrigerant delivered from a container is widely used.
[0003]
As this type of expansion valve, there is one used in a refrigeration cycle such as an automobile air conditioner shown in FIG. 6A (see, for example, Patent Document 1). That is, the refrigeration cycle 1 includes a refrigerant compressor 2 driven by an engine, a condenser 3 connected to the discharge side of the refrigerant compressor 2, a liquid receiver 4 connected to the condenser 3, and a liquid receiver An expansion valve 5 for adiabatically expanding the liquid-phase refrigerant from the vessel 4 into a gas-liquid two-phase refrigerant, and an evaporator 6 connected to the expansion valve 5. The expansion valve 5 is located in the refrigeration cycle 1. Yes.
[0004]
The expansion valve 5 is provided with a high-pressure side passage 5b through which liquid-phase refrigerant flows into the valve body 5a and a low-pressure side passage 5c through which adiabatic-expanded gas-liquid two-phase refrigerant flows out. The valve body 8d is provided with a valve body 8d for adjusting the amount of refrigerant passing through the orifice 7, and the valve body 8 is in contact with a valve seat 7a formed in the orifice 7. The refrigerant amount is adjusted.
[0005]
The expansion valve 5 is formed through the low-pressure refrigerant passage 5d in the valve body 5a, and the temperature of the refrigerant in the passage 5d is detected in the low-pressure refrigerant passage 5d so that the plunger 9a serving as a temperature sensing portion can slide. Positioned, the plunger 9a is driven by a temperature sensitive drive unit 9 fixed to the upper part of the valve body 5a. The temperature sensitive drive unit 9 is partitioned by a diaphragm 9d to form an upper hermetic chamber 9c and a lower hermetic chamber 9c ′. The disk portion 9e at the upper end of the plunger 9a comes into contact with the diaphragm 9d.
[0006]
The temperature-sensitive drive unit 9 welds the upper cover 9f and the lower cover 9g made of metal such as stainless steel to the upper and lower sides of a thin plate diaphragm 9d made of metal such as stainless steel, and thereby upper and lower airtight chambers 9c and 9c ′. The predetermined refrigerant is sealed in the upper airtight chamber 9c between the diaphragm 9d and the upper cover 9f by the refrigerant pipe 9h, and the refrigerant pipe 9h is sealed. Further, the seat of the lower cover 9g is screwed to the valve body 5a.
[0007]
In addition, as a conventional expansion valve, as shown in FIG. 6 (B) instead of the above refrigerant pipe, there is a type in which a predetermined refrigerant is sealed with a metal plug body 9i using stainless steel or the like. It is fixed to the hole of the cover 9f by welding.
[0008]
Further, a compression coil spring 8a that presses the valve body 8 in the valve closing direction via a support member 8c is disposed in the valve chamber 8d at the lower portion of the valve body 5a. The valve chamber 8d is screwed with the valve body 5a. It is formed by the adjusting screw 8b to be joined, and airtightness is maintained by the O-ring 8e. An operating rod 9b that moves the valve body 8 in the valve opening direction by sliding of the plunger 9a is in contact with the lower end of the plunger 9a.
[0009]
Then, the plunger 9a in the temperature sensitive drive unit 9 transmits the temperature in the low-pressure refrigerant passage 5d to the upper airtight chamber 9c, and the pressure in the upper airtight chamber 9c changes according to the temperature. For example, when the temperature is high, when the pressure in the upper hermetic chamber 9c increases and the diaphragm 9d pushes down the plunger 9a, the valve body 8 moves in the valve opening direction as shown in FIG. The amount of refrigerant passing through the orifice 7 increases without contacting with the temperature of the evaporator 6 and the temperature of the evaporator 6 is lowered.
[0010]
On the other hand, when the temperature is low, the pressure in the upper hermetic chamber 9c is lowered, the force for pushing down the plunger 9a by the diaphragm 9d is weakened, and the valve body 8 is compressed in the valve closing direction as shown in FIG. 7B. The coil spring 8a moves in the valve closing direction to reduce the amount of refrigerant passing through the orifice 7 and raise the temperature of the evaporator 6. 7 (A) and 7 (B) are diagrams showing the main part of the conventional example shown in FIG. 6 (A).
[0011]
Thus, the expansion valve 5 moves the valve body 8 in accordance with the temperature change in the low-pressure refrigerant passage 5d to change the opening area of the orifice 7, and adjusts the refrigerant passage amount to adjust the temperature of the evaporator 6. I am trying. In this type of expansion valve 5, the opening area of the orifice 7 that adiabatically expands from the liquid-phase refrigerant to the gas-liquid two-phase refrigerant is such that the spring coil variable compression coil spring 8 a that presses the valve body 8 in the valve closing direction. The spring load is set by adjusting the adjustment screw 8b.
[0012]
The adjustment screw 8b has a recess 8f formed at the center of the upper surface thereof, and an insertion hole 13 for inserting a tool for moving the adjustment screw 8b up and down in order to adjust the load of the compression coil spring 8a at the center of the lower surface. The bottom portion of the recess 8f is a support portion that supports the compression coil spring 8a, and serves as a spring seat surface 8f ′ against which one end of the compression coil spring 8a abuts.
[0013]
By the way, in the high pressure refrigerant sent to the expansion valve, pressure fluctuation may occur upstream in the refrigeration cycle, and the pressure fluctuation is transmitted to the expansion valve using the high pressure refrigerant liquid as a medium.
Then, in the conventional expansion valve as described above, when the upstream refrigerant pressure is transmitted to the valve body by pressure fluctuation, it may cause a problem that the operation of the valve body becomes unstable. In some cases, the flow control of the expansion valve is not accurately performed, or there is a problem that noise is generated due to vibration of the valve body.
[0014]
Therefore, as a conventional countermeasure, the valve body is biased from the side by a spring or the like to the rod disposed so as to be movable back and forth in the axial direction between the power element and the valve body so that the pressure of the high pressure side refrigerant is increased. There is a means for stabilizing the operation so as not to react sensitively to fluctuations (for example, Patent Document 2).
[0015]
[Patent Document 1]
Japanese Patent Laying-Open No. 2001-50617 (second page, FIG. 7)
[Patent Document 2]
Japanese Patent Laid-Open No. 9-222268 (pages 2 to 3, FIG. 1)
[0016]
[Problems to be solved by the invention]
However, although the conventional expansion valve as described above can achieve the purpose of stabilizing the operation against the pressure fluctuation of the high-pressure refrigerant, the spring that pushes the rod that advances and retreats in the axial direction from the side must be arranged in a stable state. Therefore, there is a risk that the structure and assembly work become complicated and high cost is required.
Therefore, an object of the present invention is to provide an expansion valve that can achieve stable operation with respect to pressure fluctuations of a high-pressure refrigerant without greatly changing the configuration of a conventional expansion valve with a simple configuration.
[0017]
[Means for Solving the Problems]
In order to achieve such an object, an expansion valve according to the present invention includes a valve body including an orifice that connects a high-pressure side passage through which refrigerant flows and a low-pressure side passage through which refrigerant flows, and an amount of refrigerant flowing through the orifice. A valve body to be adjusted, an operating rod that contacts the valve body to operate the valve body in the valve opening direction, a temperature-sensitive drive member that drives the operating rod, and a compression coil that presses the valve body in the valve closing direction In the expansion valve including a spring and an adjustment screw for adjusting the pressing force of the compression coil spring , the adjustment screw has an inclined surface formed on a support portion that supports the compression coil spring, and the inclination surface allows the The compression coil spring is inclined to cause a misalignment between the operating rod and the valve element .
[0018]
And a valve body having an orifice communicating the high-pressure side passage through which the refrigerant flows in and the low-pressure side passage through which the refrigerant flows, a valve body for adjusting the amount of the refrigerant flowing through the orifice, and abutting against the valve body An operating rod that operates the valve body in the valve opening direction, a temperature-sensitive drive member that drives the operating rod, a compression coil spring that presses the valve body in the valve closing direction, and a pressing force of the compression coil spring is adjusted. In the expansion valve including the adjusting screw, an inclined plate is provided between the compression coil spring and a support surface of the adjustment screw that supports the compression coil spring, and the compression coil spring is inclined by the inclined plate. A misalignment between the operating rod and the valve body is caused .
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of the expansion valve of the present invention, omitting the configuration of the refrigeration cycle, and the basic configuration of the conventional expansion valve shown in FIG. 6 (A). The operation is the same, and the same reference numerals are given to the same and equivalent parts as in the conventional example. In FIG. 1, the conventional example shown in FIG. 6A differs from the conventional example in that an inclined plate 10 is provided on a spring seat surface 8 f ′ which is the bottom of a recess 8 f of an adjusting screw 8 b and a compression coil spring 8 a is engaged with a support member 8 c. The structure which the stop part 8c 'is provided and the compression coil spring 8a is supported between these spring seating surfaces 8f' and the latching | locking part 8c 'differs. FIG. 1 shows a case where the refrigerant is sealed by the plug 9i shown in FIG. 6 (B).
[0021]
2 (A) and 2 (B) are the main points of the embodiment of FIG. 1 showing a configuration in which, for example, a metal or resin inclined plate 10 shown in FIG. 1 is provided on the spring seat surface 8f ′. FIG. 2A shows a state when the valve is opened.
[0022]
Thus, the upper surface of the inclined plate 10 is formed as an inclined surface 11 (inclined to the right in the drawings in FIGS. 2A and 2B), and the lower surface opposite to the upper surface is a flat surface. Yes, and is disposed in contact with the spring seat surface 8f '.
With this configuration, when the valve is opened, the inclined plate 10 provided on the spring seating surface 8f ′ makes the inclined surface 11 as an inclined means, and the compression coil spring 8a becomes the center of the axis of the inclined valve body 8 and the operating rod 9b. An eccentric state occurs, the inclined plate 10 acts as an eccentric means, and when the valve body 8 moves, it is pressed against one side of the valve seat 7a (left side in FIG. 2 (A)), and friction between it and the valve seat 7a. As a result, the sliding resistance increases, a binding force to the operating rod 9b is also generated, and the vibration of the valve body 8 is suppressed. When the valve is closed, the valve body 8 moves along the valve seat 7a, and the valve body 8 is seated on the valve seat 7a as shown in FIG.
[0023]
In the present invention, instead of the inclined plate 10 disposed on the spring seating surface 8f ′ of the adjusting screw shown in FIGS. 2A and 2B, the spring of the adjusting screw 8b ′ as shown in FIG. Of course, the seating surface itself may be formed as the inclined surface 12, and in this case, the inclined spring seating surface can be easily formed by manufacturing the adjusting screw 8b 'by resin molding.
[0024]
FIG. 4 is a longitudinal sectional view showing another embodiment of the expansion valve of the present invention, in which the configuration of the refrigeration cycle is omitted, and is basically the same as the conventional expansion valve shown in FIG. 6 (A). The configuration and operation are the same, and the same and equivalent parts as in the conventional example are denoted by the same reference numerals. In FIG. 4, the conventional example shown in FIG. 6A is different from the conventional example in that the supporting member 8c is provided with a locking portion 8c ′ of the compression coil spring 8a, and the locking portion 8c ′ is provided with an eccentric means. The configuration in which the compression coil spring 8a is supported between the stop portion 8c ′ and the spring seat surface 8f ′ is different. FIG. 4 shows a case where the refrigerant is sealed by the plug 9i shown in FIG.
[0025]
5 (A) and 5 (B) are longitudinal cross-sectional views showing the main part of another embodiment of the expansion valve shown in FIG. 4, and the state at the time of opening shown in FIG. It corresponds to the state at the time of valve closing shown in FIG. 2 (B), and the inclined plate which is the eccentric means in FIG. 2 (A) and FIG. The eccentric means is a flange portion 8C ″ that supports one end of the compression coil spring 8a. That is, in FIGS. 5A and 5B, the locking portion 8c ′ of the support member 8c is an inclined flange portion. The compression coil spring 8a is supported between the inclined flange portion 8c "of the support member 8c and the flat spring seat surface 8f 'of the adjusting screw 8b.
[0026]
According to such a configuration, when the valve is opened, the compression coil spring 8a is inclined by the inclined flange portion 8c ", and an eccentric state occurs in which the cores of the valve body 8 and the operating rod 9b are displaced, and the flange portion 8c" serves as an eccentric means. When the valve body 8 moves and the valve body 8 moves, the valve body 8 is pressed against one side of the valve seat 7a (left side in FIG. 4A), and friction is generated between the valve seat 7a, resulting in an increase in sliding resistance. As a result, a binding force to the operating rod 9b is also generated, and the vibration of the valve body 8 is suppressed. When the valve is closed, the valve body 8 moves along the valve seat 7a, and the valve body 8 is seated on the valve seat 7a as shown in FIG.
[0027]
【The invention's effect】
As understood from the above configuration, the present invention suppresses the vibration of the valve body of the expansion valve by the eccentric means for generating the misalignment between the valve body and the actuating rod. Therefore, a highly useful expansion valve can be realized without drastically changing the configuration.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of an expansion valve according to the present invention.
2A and 2B are diagrams showing a main part of the embodiment of FIG. 1, in which FIG. 2A shows a valve open state and FIG. 2B shows a valve closed state.
FIG. 3 is a view showing a modification of the adjusting screw in the embodiment of the expansion valve according to the present invention.
FIG. 4 is a longitudinal sectional view showing another embodiment of the expansion valve according to the present invention.
5 is a diagram showing a main part of another embodiment of FIG. 4, FIG. 5 (A) shows a valve open state and FIG. 5 (B) a valve open state.
6A is a cross-sectional view illustrating a configuration of a conventional expansion valve, and FIG. 6B is a diagram illustrating another example of the conventional example.
7A is a view showing a main part of a conventional example, FIG. 7A shows a valve open state, and FIG. 7B shows a valve closed state.
[Explanation of symbols]
7 Orifice 7a Valve seat 8 Valve body 8a Compression coil spring 8b Adjustment screw 8c Support member 8c 'Locking portion 8c "Hook 8f Spring bottom surface 9b Actuating rod 10 Inclined plate

Claims (2)

A valve body having an orifice communicating with a high-pressure side passage through which refrigerant flows and a low-pressure side passage through which refrigerant flows, a valve body for adjusting the amount of refrigerant flowing through the orifice, and a valve body in contact with the valve body An operating rod that operates the valve in the valve opening direction, a temperature-sensitive drive member that drives the operating rod, a compression coil spring that presses the valve body in the valve closing direction, and an adjustment screw that adjusts the pressing force of the compression coil spring In an expansion valve with
The adjustment screw has an inclined surface formed on a support portion that supports the compression coil spring,
An expansion valve characterized in that the compression coil spring is inclined by the inclined surface to cause misalignment between the operating rod and the valve body . A valve body having an orifice communicating with a high-pressure side passage through which refrigerant flows and a low-pressure side passage through which refrigerant flows, a valve body for adjusting the amount of refrigerant flowing through the orifice, and a valve body in contact with the valve body An operating rod that operates the valve in the valve opening direction, a temperature-sensitive drive member that drives the operating rod, a compression coil spring that presses the valve body in the valve closing direction, and an adjustment screw that adjusts the pressing force of the compression coil spring In an expansion valve with
An inclined plate is provided between the compression coil spring and the support surface of the adjustment screw that supports the compression coil spring.
By the inclined plate is inclined the compression coil spring, it said to cause misalignment between the actuating rod and the valve body Rise expansion valve.

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