KR20130060154A - Expansion valve - Google Patents

Abstract

PURPOSE: An expansion valve is provided to prevent the thermosensitive errors of a power element. CONSTITUTION: An expansion valve comprises a body(2), a first passage, a second passage, a third passage(20), a fourth passage(22), and a power element. First to fourth side surfaces are successively connected to form the body. The first passage is formed in the first side surface of the body so that a refrigerant can be introduced from an external heat exchanger. The second passage is formed in the second side surface of the body and is contacted to the first passage through a valve part so that the refrigerant passing through the valve part can be discharged to an evaporator. The third passage is formed in the second side surface of the body to introduce the refrigerant returned from the evaporator. The fourth passage is formed in the first side surface of the body and is connected to the third passage to form a low pressure passage bent at a right angle inside the body. The fourth passage discharges the refrigerant toward a compressor. The power element is operated by detecting the temperature and pressure of the refrigerant flowing in the lower pressure passage and controls the opening degree of the valve part with an actuating rod.

Description

Expansion valve {EXPANSION VALVE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to expansion valves and, more particularly, to expansion valves provided in a refrigeration cycle for controlling the flow rate of refrigerant sent to the evaporator.

In a refrigeration cycle of a vehicle air conditioner, generally, a compressor for compressing a circulating refrigerant, a condenser for condensing the compressed refrigerant, a receiver for separating the condensed refrigerant with gas liquid, and axial expansion of the separated liquid refrigerant are sent out in the form of fog. An expansion valve is provided, and an evaporator is provided to evaporate the refrigerant in the fog form and to cool the air in the vehicle interior using the latent heat of evaporation.

As the expansion valve, for example, a temperature type for controlling the flow rate of the refrigerant to be delivered to the evaporator by opening and closing the valve part by detecting the temperature and pressure of the refrigerant at the evaporator outlet so that the refrigerant derived from the evaporator has a predetermined degree of superheat. Expansion valves are used. The body of this expansion valve is formed with a first passage through which the refrigerant from the receiver to the evaporator passes and a second passage through the refrigerant returned from the evaporator to lead to the compressor. The first passage is provided with a valve portion for adjusting the flow rate of the refrigerant directed to the evaporator. At the end of the body, a power element for controlling the opening degree of the valve part by sensing the temperature and pressure of the refrigerant flowing through the second passage is provided.

Such an expansion valve is installed in a partition wall for dividing the engine room of the vehicle and the vehicle interior, and a plurality of pipes are connected via a plate-shaped connecting means. That is, a pipe extending from the receiver is connected to the inlet port of the first passage, and a pipe directed to the evaporator is connected to the outlet port. In addition, a pipe extending to the evaporator is connected to the inlet port of the second passage, and a pipe to the compressor is connected to the outlet port.

The general expansion valve has a foot-shaped body, the outlet port of the second passage is provided on the side where the inlet port of the first passage is provided, and the outlet port of the first passage and the inlet of the second passage are provided on the opposite side thereof. A port is provided. That is, since the first passage and the second passage are formed to extend almost in one direction, there is a possibility that a problem arises in the mounting structure of the expansion valve, for example, when the installation space of the engine room or the like is restricted. For example, as an expansion valve, when the arrangement structure which orthogonally crosses the direction of the pipe connected to an evaporator, and the direction of the pipe connected to a receiver and a compressor, it is necessary to bend the pipe of either side in the middle. In that case, an extra space for bending the pipe is also required.

In order to cope with such a case, expansion valves have also been proposed in which respective ports of the first and second passages are provided on two adjacent side surfaces of the body, and each pipe can be connected in a direction perpendicular to each other. See, for example, Patent Document 1). Thereby, expansion valve, piping, etc. can be installed in a limited installation space, without going through the complicated process of bending piping.

Japanese Patent Application Publication No. 2001-241808

However, the expansion valve of the type which connects piping to the body at a right angle to the body in this way has a complicated shape of the passage as compared to the general expansion valve, so that the flow chart of the refrigerant tends to be disturbed. Particularly, at the intersection of passages, the refrigerant must change its flow, so that the reflection of the refrigerant may cause a disturbance in the flow direction, or local congestion of the refrigerant may occur. On the other hand, in order to properly control the flow rate of the refrigerant in such an expansion valve, it is necessary to accurately sense the temperature of the refrigerant at the outlet of the evaporator by the power element, but such a passage configuration may be a factor that makes it difficult.

That is, since such an expansion valve is generally installed at the boundary between the engine room and the vehicle interior, for example, the air heated by the heat radiation of the condenser becomes hot air by the fan and comes into contact with the power element in an external atmosphere. Easily affected by temperature In addition, although the high temperature refrigerant introduced from the receiver into the first passage is changed to a low temperature by passing through the valve portion, the heat of the inlet port heated by the high temperature refrigerant is transmitted to the power element in the form of passing the second passage through the body. Therefore, the influence of the heat conduction cannot be ignored.

In particular, in the configuration in which the flow of the coolant is disturbed by providing the cross section in the second passage, the effect of reducing the heat conduction around the power element due to the flow of the low temperature coolant returned from the evaporator is also considered to be reduced. As a result, there is a possibility that the power element detects even the temperature of the external atmosphere or the temperature due to heat conduction, and cannot accurately sense the refrigerant temperature at the evaporator outlet. As a result, there is a possibility of causing a drop in cooling power due to a temperature error and the inability to adequately control the degree of superheat at the outlet of the evaporator and the occurrence of hunting that opens and closes the valve unit independently of control. have.

SUMMARY OF THE INVENTION In order to solve such problems, an object of the present invention is to prevent or suppress a thermal error in a power element in an expansion valve of a type in which a port for pipe connection is provided on two adjacent side surfaces of a body, respectively. .

In order to solve the said subject, the expansion valve which concerns on one aspect of this invention is provided in a refrigeration cycle, throttles and expands by supplying the refrigerant | coolant which flowed in through the external heat exchanger through an internal valve part, and supplies it to an evaporator, and returns from the evaporator. An expansion valve which senses a pressure and a temperature of a refrigerant to control the opening degree of a valve unit and draws the refrigerant toward a compressor, comprising: a foot-shaped body in which the first side to the fourth side are sequentially adjacent to each other; A first passage opening in the first side and for introducing refrigerant from an external heat exchanger; A second passage opening in the second side and connected through the first passage and the valve portion to lead the refrigerant through the valve portion to the evaporator; A third passage opening in the second side and introducing a refrigerant from the evaporator; A fourth passage opening in the first side and connected to the third passage to form a low pressure passage, which is bent at a right angle in the body, to guide the refrigerant toward the compressor; The power element is provided on the side opposite to the first passage of the body, and senses the temperature and pressure of the refrigerant flowing through the low pressure passage, and adjusts the opening of the valve portion through an operating rod traversing the low pressure passage. Equipped.

The third passage is formed of a first hole that is not penetrated from the second side toward the fourth side, and is formed such that the tip of the first hole stays in the fourth passage, and the fourth passage is formed on the first side. It consists of the 2nd hole which perforated without penetrating to a 3rd side surface, and the front-end | tip of this 2nd hole is formed so that it may cross a 3rd path.

According to this aspect, in the foot-shaped body, the first passage opening on the first side is connected to the external heat exchanger, the fourth passage is connected to the compressor, while the second passage opening on the second side is the inlet of the evaporator. The third passage is connected to the outlet of the evaporator. For this reason, the third side and the fourth side are relatively largely exposed to the engine room and exposed to the high temperature environment, and the fourth passage parallel to the fourth side is long enough to cross the intersection with the third passage, It is formed to extend to a position close to the side. For this reason, the temperature rise of a 3rd side surface and a 4th side surface can be suppressed by the low temperature refrigerant | coolant which flows through a 4th channel | path. In addition, since a high-temperature refrigerant is introduced into the first passage, the heat is conducted to the power element through the body, and the heat transfer path is made relatively small by forming a fourth passage between the first passage and the power element. The heat conduction can be suppressed. As a result, the power element is not easily affected by the external environment or heat conduction, so that the thermal error can be prevented or suppressed.

On the other hand, with respect to the third passage, the tip thereof stays in the fourth passage and the shape of the corner portion bent at a right angle in the low pressure passage is relatively smooth, whereby the refrigerant is directed from the inlet of the third passage toward the outlet of the fourth passage. It can stabilize the flow. As a result, the cooling effect of the body by the low temperature refrigerant flowing through the low pressure passage can be improved.

According to the present invention, in the expansion valve of the type in which the ports for pipe connection are provided on two adjacent side surfaces of the body, respectively, it is possible to prevent or suppress a thermal error in the power element.

1 is a front view of an expansion valve according to an embodiment.
2 is a right side view of the expansion valve.
3 is a left side view of the expansion valve.
4 is a sectional view taken along line AA in Fig.
5 is a cross-sectional view taken along line BB of FIG. 2.
6 is a cross-sectional view taken along line CC of FIG. 1.
7 is a graph showing the results of confirmatory tests conducted to verify the effect of the embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, in the following description, the positional relationship of each structure may be expressed on the basis of the state of illustration for convenience.

This embodiment embodies the expansion valve of this invention as a thermal expansion valve applied to the refrigeration cycle of the automotive air conditioner. 1 is a front view of an expansion valve according to an embodiment. 2 is a right side view of the expansion valve. 3 is a left side view of the expansion valve.

The expansion valve 1 is provided with the body 2 formed by carrying out predetermined | prescribed cutting process to the member obtained by extrusion molding the raw material which consists of aluminum alloys. The body 2 is in the shape of a foot, and therein is provided a valve portion for performing axial expansion of the refrigerant. At the end of the body 2 in the longitudinal direction, a power element 3 functioning as a temperature sensing portion and a cover 4 covering the outside thereof are provided. The lower portion of the body 2 is formed narrow by the extrusion molding.

On the side of the body 2, an introduction port 6 for introducing a high-temperature / high-pressure liquid refrigerant from the receiver side (the condenser side as an "external heat exchanger") and a low-temperature / low pressure throttled by the expansion valve 1 A derivation port 7 for guiding the refrigerant toward the evaporator, an introduction port 8 for introducing the refrigerant evaporated by the evaporator, and a derivation port 9 for guiding the refrigerant passing through the expansion valve 1 to the compressor side are provided. .

That is, as shown in FIG. 1, the introduction port 6 is opened in the lower part of the front surface (corresponding to the "first side surface") of the body 2, and the discharge port 9 is opened in the upper part. The screw hole 10 is provided between the introduction port 6 and the extraction port 9. On the other hand, as shown in FIG. 2, the induction port 7 is opened in the lower part of the right side (corresponding to the "second side surface") of the body 2, and the inlet port 8 is opened in the upper part. As shown in FIG. 2 and FIG. 3, a pair of mounting holes 12 penetrate the body 2 between the guide port 7 and the introduction port 8 in a horizontal arrangement.

4 is a cross-sectional view taken along the line A-A of FIG. 5 is a cross-sectional view taken along the line B-B in FIG. 6 is a cross-sectional view taken along the line C-C of FIG.

As shown in FIG. 4 and FIG. 5, the body 2 has a first passage 14 communicated with the introduction port 6, a second passage 16 communicated with the delivery port 7, and a combination thereof. The first refrigerant passage is formed by the valve hole 18. That is, the first refrigerant passage is bent at right angles to the boundary of the valve portion provided in the middle portion thereof, and the refrigerant introduced from the introduction port 6 is axially expanded in the valve portion to form a fog, and the discharge portion from the discharge port 7 Draw towards the evaporator.

On the other hand, the second refrigerant passage (corresponding to the "low pressure passage") is configured by the third passage 20 communicating with the introduction port 8 and the fourth passage 22 communicating with the evacuation port 9. That is, the second refrigerant passage is bent at a right angle at the connecting portion between the third passage 20 and the fourth passage 22, introduces refrigerant from the introduction port 8, and guides the refrigerant from the extraction port 9 toward the compressor. .

That is, the valve hole 18 is provided in the intermediate part of the 1st refrigerant path in the body 2. As shown in FIG. The valve seat 26 is formed by the open end edge of the valve hole 18 at the introduction port 6 side. A ball-shaped valve body 28 is disposed on the valve seat 26 so as to face from the introduction port 6 side. The lower end of the body 2 is provided with a communication hole 30 which communicates the inside and the outside so as to be perpendicular to the first refrigerant passage, and an adjust screw 32 is screwed to seal the communication hole 30. It is.

The valve body 28 is supported from below by the support member 34, and the spring 36 which presses the valve body 28 in the locking direction between the support member 34 and the adjustment screw 32 ( Function as a "pressing member". The load of the spring 36 can be adjusted by adjusting the insertion amount of the adjustment screw 32 into the body 2. An O-ring 38 is provided between the adjustment screw 32 and the body 2 to prevent leakage of the refrigerant.

On the other hand, at the upper end of the body 2, a communication hole 40 communicating internally and externally so as to be orthogonal to the second refrigerant passage is formed, and the power element 3 is screwed to seal the communication hole 40. . The power element 3 is provided so that the diaphragm 46 which consists of metal thin plates may be inserted between the upper housing 42 and the lower housing 44, and the disk 48 is arrange | positioned at the lower housing 44 side. It is. A gas for temperature reduction is enclosed in the sealed space surrounded by the upper housing 42 and the diaphragm 46. An O-ring 50 is provided between the power element 3 and the body 2 to prevent leakage of the refrigerant. The pressure and temperature of the refrigerant passing through the second refrigerant passage are transmitted to the lower surface of the diaphragm 46 through the holes or slits provided in the communication hole 40 and the disk 48.

In the center part of the body 2, the hole 52 which has a step | step which connects a 1st refrigerant path and a 2nd refrigerant path is provided, and the long operation rod 54 is formed in the small diameter part of the hole 52 which has this step | step ) Is slidably inserted. The operating rod 54 is provided between the disk 48 and the valve body 28. Thereby, the driving force by the displacement of the diaphragm 46 is transmitted to the valve body 28 through the disk 48 and the actuating rod 54, and it opens and closes a valve part. In the large diameter portion of the hole 52 having a step, a sealing O-ring 56 is disposed so as to be inserted to the outside with respect to the working rod 54, so that the refrigerant leaks between the first refrigerant passage and the second refrigerant passage. This is being prevented.

The upper half of the actuating rod 54 is inserted into the cylindrical holder 58 arranged to cross the second refrigerant passage. The holder 58 is press-inserted into the large part of the diameter of the hole 52 whose lower end part has a level | step difference, and restrict | limits the movement of the O-ring 56 by the lower end surface. The upper end of the actuating rod 54 abuts while being inserted into a recess provided in the lower surface of the disk 48, and the lower end of the actuating rod 54 abuts the valve body 28 while being inserted into the valve hole 18. Between the holder 58 and the actuating rod 54, the spring 60 which provides a predetermined lateral load to the actuating rod 54 is provided. By this lateral load, the vibration of the working rod 54 by the fluctuation of the refrigerant pressure is suppressed.

And as shown in FIG. 6, the body 2 has the width | variety W1 of front and rear in the cross-sectional position in which the 2nd refrigerant path (the 3rd channel 20 and the 4th channel 22) is provided. The distance between the first side and the third side) is formed to be larger than the left and right width W2 (the distance between the second side and the fourth side), and the fourth passage 22 is longer than the third passage 20. It is configured to The central axis of the actuating rod 54 is located in the center of the front-back direction and slightly to the left of the left-right direction.

The fourth passage 22 is formed by drilling a hole from the first side face to the third side face by a drill, but the tip of the hole reaches the vicinity of the third side face. In this embodiment, the distance L2 from the central axis of the actuating rod 54 to the tip of the hole is not less than 70% of the distance L1 of the center axis of the actuating rod 54 and the third side surface (L2? 0.7L1). It is formed so that it may become. As shown, the third passage 20 is formed such that its tip stays within the fourth passage 22, and the fourth passage 22 is formed such that its tip exceeds the third passage 20. As shown in FIG.

The expansion valve 1 comprised as mentioned above is manufactured as follows. That is, first of all, an aluminum alloy billet is extruded in one direction (that is, a direction connecting the front and back of the body 2) by extrusion using a predetermined mold to form a material of the body 2. The member is shaped into a shape along the contour of its front face. Then, the semifinished product of the body 2 is formed by cutting the member in a direction perpendicular to the extrusion direction. The body 2 can be obtained by giving predetermined cutting processes, such as a piercing, about this semi-finished product.

The first refrigerant passage and the second refrigerant passage are formed by drilling holes in adjacent sides of the semifinished product, respectively. Particularly, for the second refrigerant passage, as shown in FIG. 6, the drill is drawn from the front (first side) of the body 2 toward the back (third side), for example, using a drill having a tip angle of 120 degrees. The fourth passage 22 is formed by drilling the port 9 and the coaxial hole (corresponding to the "second hole"). At this time, the drill is drilled until the tip reaches the above-described depth.

Then, from the right side (second side) of the body 2 to the left side (fourth side), for example, using a drill having a tip angle of 120 degrees, the introduction port 8 and the coaxial hole ("first hole" Perforated) to form the third passage 20. At this time, the tip of the drill is drilled to a depth enough to stay in the fourth passage (22). As a result, the fourth passage 22 passes through the sidewall of the third passage 20, but the third passage 20 does not touch the sidewall of the fourth passage 22.

The expansion valve 1 is connected via a pipe (not shown) and a pipe connected to the evaporator. The plate is provided with support holes at positions facing the lead-out port 7 and positions facing the introduction port 8 when set on the body 2, and screwed at positions facing the mounting holes 12, respectively. Holes are formed respectively. In each of the supporting holes, the connecting portions of the pipes connected to the inlet of the evaporator and the pipes connected to the outlet of the evaporator are respectively inserted to be supported so as not to fall off. The tip of each pipe is inserted into the lead-out port 7 and the inlet port 8 through a sealing member such as an O-ring, respectively, so that the plate and the body 2 are brought into contact with each other. Then, the plate and the body 2 are fastened by inserting the long bolts into the pair of mounting holes 12 and screwing them into the screw holes of the plate.

In addition, the expansion valve 1 is connected through a pipe (not shown) and a pipe connected to the receiver and a pipe connected to the compressor. The plate is provided with a supporting hole at a position facing the inlet port 6 and a position facing the lead port 9 when set at the body 2, and a insertion hole at a position facing the screw hole 10. Is provided. In each of the supporting holes, the connecting portion of the pipe connected to the outlet of the receiver and the pipe connected to the inlet of the compressor are respectively inserted to be supported so as not to fall off. The front end of each pipe is inserted into the introduction port 6 and the discharge port 9 through a sealing member such as an O-ring, respectively, so that the plate and the body 2 are brought into contact with each other. Then, the plate and the body 2 are fastened by inserting a predetermined bolt into the insertion hole of the plate and screwing it into the screw hole 10.

In the expansion valve 1 configured as described above, the power element 3 senses the pressure and temperature of the refrigerant returned from the evaporator through the introduction port 8, and the diaphragm 46 is displaced. The displacement of the diaphragm 46 becomes a driving force and is transmitted to the valve body 28 through the disk 48 and the operating rod 54 to open and close the valve portion. On the other hand, the liquid refrigerant supplied from the receiver is axially expanded by being introduced from the inlet port 6 and passing through the valve portion consisting of the valve body 28 and the valve seat 26 to form a low-temperature, low-pressure mist-like refrigerant. Becomes The refrigerant is led out of the lead port 7 towards the evaporator.

As described above, in the expansion valve 1 of the present embodiment, the first passage 14 opened in the front surface (first side surface) of the body 2 having a foot shape is connected to the receiver (condenser side), The fourth passage 22 is connected to the compressor, while the second passage 16 opening on the right side (second side) is connected to the inlet of the evaporator, and the third passage 20 is connected to the outlet of the evaporator. For this reason, the rear face (third side) and the left side (fourth side) are relatively largely exposed to the engine room, and are exposed to the high temperature environment, as shown in FIG. 6, on the left side (fourth side). The fourth parallel passage 22 is formed to be relatively long. In addition, the fourth passage 22 is formed to a position relatively close to the rear surface (third side surface).

For this reason, the temperature rise of a back surface and a left surface can be suppressed by the low temperature refrigerant | coolant which flows through the 4th channel | path 22. As shown in FIG. In addition, as shown in FIG. 4, since the high-temperature refrigerant from the condenser side is introduced into the first passage 14, the heat is conducted to the power element 3 through the body 2. By constituting the fourth passage 22 largely between the 14 and the power element 3, the heat transfer path can be reduced, and the heat conduction can be suppressed. As a result, the power element 3 is not easily affected by the external environment or heat conduction, and the thermal error can be prevented or suppressed.

7 is a graph showing the results of confirmatory tests conducted to verify the effect of the embodiment. 7 represents the depth of the hole forming the fourth passage 22 (see FIG. 6), specifically, the distance L2 from the central axis of the working rod 54 to the tip of the hole is defined as the working rod ( It is shown by the ratio with respect to the distance L1 of the center axis | shaft of 54) and the back surface (third side surface) of the body 2. As shown in FIG. One of the longitudinal axes of FIG. 7 represents the temperature (referred to as “body temperature”) Tb (° C.) of the body 2 near the power element 3, and the other represents vibration of the refrigerant temperature at the evaporator outlet side (ie, hunting). ) ΔTe (° C.).

That is, here, the result of having tested to confirm the influence of the hole depth of the 4th channel | path 22 on hunting suppression is shown. Moreover, as test conditions, the ambient temperature Ta of the expansion valve 1 was 80 degreeC, the set refrigerant temperature Te on the outlet side of the evaporator was 10 degreeC, and the set rotation speed of the compressor was 780 rpm. This test condition reproduces the test condition at the time of idling which is a problem in a real vehicle. Since there is no running wind during idling, the ambient temperature of the expansion valve becomes substantially the same as the temperature of the engine room, and the harshest to maintain the performance of the expansion valve. In other words, it is required to maintain the performance of the expansion valve under these harsh conditions.

Therefore, the confirmation test was performed about the effectiveness of this embodiment in this condition. As a result, when the depth ratio L2 / L1 became 50% or more, the body temperature Tb was greatly reduced, and the hunting ΔTe was also significantly decreased. In particular, when the depth ratio L2 / L1 is 70% or more, it can be seen that the body temperature Tb almost converges and the hunting ΔTe also becomes almost zero. As shown, when the depth ratio L2 / L1 exceeds 95%, the thickness of the body 2 formed between the tip of the hole and the back (third side surface) is small, and considering the variation in processing, There is a possibility of problems. On the other hand, when the depth ratio L2 / L1 is 42% or less, the tip of the hole does not exceed the third passage 20.

From the above test results, the fourth passage 22 has 95% or less of the tip of the hole toward the third side of the body 2 from the central axis of the actuating rod 54 while having a depth ratio L2 / L1 of 50% or more. It was found that a good effect can be obtained by positioning at a depth of. Moreover, it turned out that when the depth ratio L2 / L1 becomes 70% or more and 95% or less, a more remarkable effect can be obtained.

As mentioned above, although this invention was described about preferable embodiment, this invention is not limited to the above specific embodiment, Of course, various deformation | transformation is possible within the range of the technical thought of this invention.

In the said embodiment, although the example which applied the expansion valve 1 to the refrigeration cycle provided with a condenser as an external heat exchanger was shown, of course, you may apply to the refrigeration cycle provided with a gas cooler as an external heat exchanger.

1: Expansion valve
2: Body
3: Power element
6: introduction port
7, 8, 9: derived port
10: screw hole
12: mounting hole
14: first passage
16: second passage
18: Valve hole
20: third passage
22: fourth passage
26: valve seat
28: valve body
46: diaphragm
54: working rod

Claims (5)

It is provided in the refrigeration cycle, the refrigerant flowing through the external heat exchanger through the internal valve portion is axially expanded to supply to the evaporator, by detecting the pressure and temperature of the refrigerant returned from the evaporator to control the opening degree of the valve portion, In the expansion valve for drawing the refrigerant toward the compressor,
A foot-shaped body in which the first side to the fourth side are adjacent to each other in sequence;
A first passage opening in the first side and for introducing a refrigerant from the external heat exchanger;
A second passage opening in the second side surface and connected through the first passage and the valve portion to lead the refrigerant through the valve portion to the evaporator;
A third passage opening in the second side and introducing a refrigerant from the evaporator;
A fourth passage opening in the first side surface, the fourth passage being connected to the third passage to form a low pressure passage bent at a right angle in the body, and leading the refrigerant toward the compressor; And
An opening degree of the valve portion through an operating rod provided on the side opposite to the first passage with respect to the low pressure passage of the body and sensing the temperature and pressure of the refrigerant flowing through the low pressure passage, and crossing the low pressure passage. Power element to adjust
Lt; / RTI >
The third passage is formed of a first hole that is not penetrated from the second side toward the fourth side, and is formed such that the tip of the first hole stays in the fourth passage.
The fourth passage includes a second hole that is not penetrated from the first side toward the third side, and the tip of the second hole is formed so as to cross the third passage. . The method of claim 1,
And said first hole and said second hole are formed by drilling and adjusting the depth of drilling. The method according to claim 1 or 2,
And the tip of the second hole is formed so as to reach a depth that is at least 70% of their distance from the central axis of the actuating rod toward the third side surface. The method according to claim 1 or 2,
An expansion valve, characterized in that the tip of the second hole is located at a depth of 50% or more and 95% or less of their distance from the central axis of the working rod toward the third side surface. 5. The method of claim 4,
An expansion valve, characterized in that the tip of the second hole is located at a depth of 70% or more and 95% or less of their distance from the central axis of the working rod toward the third side surface.

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