JP7779071B2 - Electronic Expansion Valve - Google Patents

Description

This invention relates to an electronic expansion valve, and more particularly to an electronic expansion valve that allows refrigerant to flow when the valve element moves away from the valve seat.

Conventionally, electronic expansion valves are known that allow refrigerant to flow when the valve disc separates from the valve seat (see, for example, Patent Document 1).

Patent Document 1 above discloses an electronic expansion valve for use in a refrigeration cycle, which includes an upper body portion, a side body portion, a valve seat, and a valve element. In the electronic expansion valve of Patent Document 1, the upper body portion and the side body portion form the main body. Furthermore, the electronic expansion valve of Patent Document 1 is configured to allow refrigerant to flow when the valve element moves away from the valve seat.

JP 2011-196596 A

Although not explicitly stated in Patent Document 1, electronic expansion valves used in refrigeration cycles have a refrigerant passing through the interior of their housing (main body), so the internal pressure of the refrigerant acts on the housing. Therefore, in the case of electronic expansion valves whose housing is made up of multiple joined components, it is conceivable to increase the mechanical strength to prevent the housing from deforming due to the internal pressure of the refrigerant. Therefore, to increase the mechanical strength, it is necessary to increase the thickness of the components or to increase the joint strength by using reinforcing components. However, increasing the thickness of the components or increasing the joint strength by using reinforcing components complicates the device configuration, so there is a demand for simplifying the device configuration.

This invention was made to solve the above-mentioned problems, and one object of this invention is to provide an electronic expansion valve that can simplify the device configuration while suppressing deformation of the housing.

An electronic expansion valve according to one aspect of the present invention is an electronic expansion valve used in a refrigeration cycle in which a refrigerant circulates, and comprises a housing including an annular member forming a flow path through which the refrigerant passes and a main body abutting the outer peripheral surface of the annular member; a valve seat including a through hole through which the refrigerant passes; a valve disc arranged opposite the valve seat and configured to move relative to the valve seat to close and open the through hole; a yoke arranged opposite the valve disc; and a movement mechanism including a coil that generates a magnetic force in the yoke, and which moves the valve disc relative to the valve seat using the magnetic force. The annular member has a yoke joined to its inner peripheral surface surrounding a central hole, and includes an inclined portion that slopes toward the valve disc as it moves from the outer peripheral surface of the annular member toward the inner peripheral surface, or a first protruding portion that protrudes the inner peripheral surface abutting the yoke toward the valve disc, when viewed in cross section along the movement direction of the valve disc, so that internal pressure due to the refrigerant is received as a force toward the center where the yoke is located.

In one aspect of the electronic expansion valve of the present invention, as described above, the annular member has a yoke bonded to its inner circumferential surface surrounding a central hole. The annular member includes a sloped portion that slopes toward the valve member as it moves from the outer circumferential surface of the annular member toward the inner circumferential surface, or a first protrusion that protrudes the inner circumferential surface that abuts the yoke toward the valve member, when viewed in a cross-sectional view along the direction of movement of the valve member, so that the internal pressure from the refrigerant is received as a force toward the center where the yoke is located. This allows the direction of the internal pressure acting on the sloped portion to be dispersed into a force toward the center of the annular member where the yoke is located, and a force from the valve member toward the yoke, perpendicular to the direction toward the center. This reduces the force from the valve member toward the yoke, thereby reducing the force that pushes the annular member from the valve member toward the yoke and deforms it. Furthermore, because the force toward the center presses the annular member against the yoke, there is no need to increase the bond strength between the annular member and the yoke. As a result, deformation of the housing (annular member) can be suppressed while simplifying the device configuration. Furthermore, when a first protrusion is provided, the internal pressure of the refrigerant acts on the first protrusion as a force toward the center of the annular member, since the first protrusion protrudes toward the valve body. This allows the annular member to be pressed against the yoke by a force toward the center, eliminating the need to increase the bonding strength between the annular member and the yoke. As a result, deformation of the housing (annular member) can be suppressed, and the device configuration can be simplified.

In the electronic expansion valve according to the above aspect, preferably, the annular member is configured so that a portion of its outer surface that abuts against the inner surface of the main body is joined to the inner surface of the main body, and the outer surface of the annular member abuts against the inner surface of the main body from the portion joined to the inner surface of the main body toward the valve body so that internal pressure from the refrigerant is received as a force toward the outer circumference of the annular member. With this configuration, when internal pressure from the refrigerant acts on the outer surface of the annular member, a rotational moment acts on the annular member in the direction opposite to the direction moving the annular member away from the yoke, centered on the joint between the annular member and the main body, suppressing deformation of the annular member. This prevents deformation of the housing (annular member) in the direction away from the yoke.

In this case, the outer periphery of the annular member preferably has a second protrusion that protrudes from the portion joined to the inner periphery of the main body toward the valve body. With this configuration, the second protrusion increases the area of the outer periphery of the annular member on which the internal pressure of the refrigerant acts, thereby increasing the rotational moment that suppresses deformation of the annular member, centered around the joint between the annular member and the main body. As a result, deformation of the housing (annular member) in a direction away from the yoke can be further suppressed.

In the electronic expansion valve according to the above aspect, the annular member preferably includes an inclined portion, and is configured such that, when viewed in a cross-section along the direction of movement of the valve disc, the length of the inclined portion abutting the yoke along the direction of movement of the valve disc is greater than the length of the portion of the annular member, excluding the outer periphery, that does not include the inclined portion along the direction of movement of the valve disc. This configuration allows the length of the inclined portion along the direction of movement of the valve disc to be increased, thereby increasing the contact area between the annular member and the yoke and making it less likely for the annular member to separate from the yoke. Furthermore, if a joint portion is disposed at one end of the contact portion between the yoke and the inclined portion, the distance from the end with the joint portion to the other end without the joint portion increases, thereby increasing the rotational moment that suppresses deformation of the annular member around the other end of the contact portion between the yoke and the inclined portion as a fulcrum. As a result, the annular member can be pressed firmly against the yoke joined to the center of the annular member, thereby suppressing deformation of the housing (annular member) in a direction away from the yoke.

In this case, the inclined portion is preferably configured to incline up to the vicinity of the end of the yoke on the valve disc side. With this configuration, when a joint is disposed at one end of the contact area between the yoke and the inclined portion, the distance from the end with the joint to the other end without the joint can be maximized. This reliably increases the contact area between the annular member and the yoke and makes it even more difficult for the housing (annular member) to separate from the yoke. Furthermore, since the distance from the end with the joint to the other end without the joint can be maximized, the rotational moment that suppresses deformation of the annular member around the other end of the contact area between the yoke and the inclined portion as a fulcrum can be maximized. As a result, the annular member can be firmly pressed against the yoke joined to the center of the annular member, effectively suppressing deformation of the housing (annular member) in a direction away from the yoke. Note that "nearby" includes cases where the end of the yoke on the valve disc side and the end of the annular member are located at the same position or close to each other in a cross-sectional view taken along the direction of movement of the valve disc.

In the electronic expansion valve according to one aspect of the present invention, the annular member preferably includes a first protrusion, and is configured such that, in a cross-sectional view along the direction of movement of the valve disc, the length of the first protrusion along the direction of movement of the valve disc is greater than the length along the direction of movement of the valve disc of the portion of the annular member where the first protrusion is not provided, excluding the outer periphery of the annular member. This configuration allows the length of the first protrusion along the direction of movement of the valve disc to be increased, thereby increasing the contact area between the annular member and the yoke and making it difficult for the housing (annular member) to separate from the yoke. Furthermore, if a joint is provided at one end of the contact portion between the yoke and the first protrusion as viewed along the direction of movement of the valve disc, the distance from the end where the joint is provided to the other end where the joint is not provided increases, thereby increasing the rotational moment that suppresses deformation of the annular member around the other end of the contact portion between the yoke and the first protrusion as a fulcrum. As a result, the annular member can be pressed against the yoke joined to the center of the annular member, thereby suppressing deformation of the housing (annular member) in a direction away from the yoke.

In this case, the first protrusion is preferably configured to protrude close to the end of the yoke on the valve body side. With this configuration, when a joint is disposed at one end of the contact portion between the yoke and the first protrusion, the distance from the end with the joint to the other end without the joint can be maximized. This reliably increases the contact area between the first protrusion and the yoke and makes it even more difficult for the housing (annular member) to separate from the yoke. Furthermore, since the distance from the end with the joint to the other end without the joint can be maximized, the rotational moment that suppresses deformation of the annular member around the other end of the contact portion between the yoke and the first protrusion as a fulcrum can be maximized. As a result, the annular member can be firmly pressed against the yoke joined to the center of the annular member, effectively suppressing deformation of the housing (annular member) from separating from the yoke. Note that "close" includes cases where the end of the yoke on the valve body side and the end of the annular member are located at the same position or close positions in a cross-sectional view taken along the direction of movement of the valve body.

The present invention provides an electronic expansion valve that can simplify the device configuration while suppressing deformation of the housing.

FIG. 1 is a diagram showing an example of a showcase in which an electronic expansion valve is used. FIG. 2 is a block diagram showing a refrigeration cycle. 1 is a cross-sectional view of an electronic expansion valve according to a first embodiment. FIG. FIG. 2 is a partially enlarged view of the annular member according to the first embodiment. 5 is a partially enlarged view of the annular member for explaining the moment of force acting on the joint between the inclined portion and the yoke according to the first embodiment. FIG. FIG. 10 is a cross-sectional view of an electronic expansion valve according to a second embodiment. FIG. 10 is a partially enlarged view of an annular member according to a second embodiment. 10 is a partially enlarged view of an annular member for explaining a moment of force acting on a joint between a first protrusion and a yoke according to a second embodiment. FIG.

[First embodiment]
An example in which the electronic expansion valve 1 in the first embodiment is used in a refrigeration cycle 100a will be described.

(Configuration of cooling device)
1, the refrigeration cycle 100a is configured to circulate a refrigerant and perform heat exchange to cool an object to be cooled. The refrigeration cycle 100a of the first embodiment is used to cool air flowing through a plurality of showcases 100, which are cooling devices. The refrigerant is, for example, R410A, R408A, or carbon dioxide ( _CO2 ).

As shown in Figures 1 and 2, the refrigeration cycle 100a comprises an electronic expansion valve 1, an evaporator 2, a compressor 3, and a condenser 4. When cooling multiple showcases 100, an electronic expansion valve 1 and an evaporator 2 are provided for each showcase 100, and the refrigerant condensed by the condenser 4 is distributed to the electronic expansion valve 1 for each showcase 100. The evaporated refrigerant from the evaporator 2 for each showcase 100 then collects and flows into the compressor 3.

The electronic expansion valve 1 is configured to expand the high-pressure, liquid-phase refrigerant condensed by the condenser 4. In the first embodiment, the electronic expansion valve 1 is a pulse type. The detailed structure of the electronic expansion valve 1 will be described later.

The evaporator 2 is configured to evaporate the refrigerant, which has been expanded by the electronic expansion valve 1 and is now in a low-pressure, gas-liquid two-phase state. Specifically, the refrigerant is evaporated by exchanging heat with the air to be cooled and receiving heat from the air to be cooled. The air cooled by the evaporator 2 cools the shelves 101 inside the showcase 100.

The compressor 3 is configured to compress the gas phase refrigerant evaporated in the evaporator 2 to a high pressure.

The condenser 4 is configured to condense the high-pressure refrigerant discharged from the compressor 3 into high-pressure liquid-phase refrigerant.

(Structure of electronic expansion valve)
As shown in FIG. 3 , the electronic expansion valve 1 includes a housing 20 including an annular member 11 and a main body 12, a valve seat 13, a valve element 14, and a moving mechanism 15 including a yoke 15 a and a coil 15 b. The electronic expansion valve 1 is configured so that refrigerant condensed in the condenser 4 is supplied into the housing 20. The moving mechanism 15 moves the valve element 14 away from the valve seat 13, thereby supplying the refrigerant to the evaporator 2. In the first embodiment, the valve element 14 moves vertically. The direction in which the valve element 14 moves is defined as the Z direction, with the valve element 14 side designated Z1 and the valve seat 13 side designated Z2. Among directions perpendicular to the Z direction, the left-right direction on the paper is defined as the X direction, with the left side of the paper designated as the X1 side and the right side of the paper designated as the X2 side. The direction perpendicular to the X and Z directions is defined as the Y direction, with the front side of the paper designated as the Y1 side and the back side of the paper designated as the Y2 side.

As shown in Figure 4, when viewed in the movement direction (Z direction) of the valve body 14, the annular member 11 has a circular ring shape with a hole 11a at its center. A yoke 15a (see Figure 3) is joined to the inner circumferential surface of the annular member 11 surrounding the hole 11a.

As shown in Figure 3, the annular member 11 is provided around the valve body 14. A refrigerant passage is formed between the annular member 11 and the outer surface of the valve body 14. The refrigerant is supplied throughout the housing 20 along the annular member 11.

The annular member 11 includes an inclined portion 11b. When viewed in a cross-section along the movement direction (Z direction) of the valve disc 14, the inclined portion 11b is configured to incline toward the Z2 side so as to approach the valve disc 14 from the outer peripheral surface of the annular member 11 (the side where the outer peripheral surface 11c of the annular member 11 abuts the inner peripheral surface of the main body portion 12) toward the inner peripheral surface (the side where the inner peripheral surface of the annular member 11 abuts the outer peripheral surface of the yoke 15a). The inclination angle of the inclined portion 11b is preferably 45 degrees or greater. It is preferable that the proportion of the inclined portion 11b in the X direction of the annular member 11 be greater than the proportion of the portion of the annular member 11 that does not have the inclined portion 11b, excluding the outer peripheral portion. Note that while Figure 3 shows a cross-section cut along the X direction, the annular member 11 has the same structure as shown in Figure 3 when viewed in a cross-section cut along the Y direction.

As shown in FIG. 5, the annular member 11 has a first joint 16 formed on a portion of the outer peripheral surface 11c of the annular member 11 that abuts against the inner peripheral surface of the main body portion 12 (the surface facing the yoke 15a). The first joint 16 is formed on the inner peripheral surface and upper surface of the main body portion 12. The annular member 11 has a second joint 17 formed on the Z1-side surface of the annular member 11 that abuts against the yoke 15a. The joining method is, for example, laser welding. Note that while FIG. 5 is a cross-sectional view taken along the X direction, the annular member 11 has the same structure as that shown in FIG. 5 when viewed along the Y direction.

The outer periphery of the annular member 11 is provided with leg portions 11d that protrude from the portion joined to the inner periphery of the main body portion 12 toward the valve body 14 (Z2 side). The annular member 11 is configured so that the outer periphery 11c of the annular member 11 abuts against the inner periphery of the main body portion 12 via leg portions 11d from the portion joined to the inner periphery of the main body portion 12 toward the valve body 14 (Z2 side) so that it receives internal pressure from the refrigerant in the outer periphery (toward the main body portion 12). Note that leg portions 11d are an example of a "second protrusion" as defined in the claims.

When viewed in cross section along the movement direction (Z direction) of the valve disc 14, the annular member 11 is configured so that the length L1 of the inclined portion 11b abutting against the yoke 15a along the movement direction (Z direction) of the valve disc 14 is greater than the length L2 of the portion of the annular member 11 where the inclined portion 11b is not provided, excluding the outer periphery, along the movement direction (Z direction) of the valve disc 14.

As shown in Figure 3, the main body 12 has a valve seat 13 and a valve element 14 arranged inside. The main body 12 has a cylindrical shape that opens to the Z1 side, and the annular member 11 is attached to the Z1 side. The housing 20 is formed by attaching the annular member 11 to the main body 12.

The valve seat 13 has a through-hole 13a through which the refrigerant passes. The valve seat 13 is made of stainless steel. The valve seat 13 is made of non-magnetic austenitic stainless steel. The valve seat 13 has a circular shape when viewed in the direction of movement of the valve disc 14 (Z direction).

The valve disc 14 faces the movement mechanism 15. The valve disc 14 moves in the vertical direction (Z direction) by the movement mechanism 15. The valve disc 14 also faces the valve seat 13 in the vertical direction (Z direction). The valve disc 14 is made of ferritic stainless steel, which is easily magnetized. The valve disc 14 has a circular shape when viewed in the movement direction (Z direction) of the valve disc 14.

The moving mechanism 15 includes a yoke (iron core) 15a and a coil 15b. The coil 15b generates a magnetic force in the yoke 15a. When current is applied to the coil 15b, the moving mechanism 15 generates a magnetic force, attracting the valve disc 14 and separating it from the valve seat 13, thereby opening the electronic expansion valve 1. When the coil 15b is not energized, the valve disc 14 abuts against the valve seat 13, substantially sealing the through-hole 13a and closing the electronic expansion valve 1. The yoke 15a has a stepped portion formed on its Z2-side surface that abuts against the Z1-side surface and the inner circumferential surface of the top surface of the annular member 11 toward the center.

The internal pressure acting on the annular member 11 will be explained based on Figure 5. Note that Figure 5 is an enlarged view of a portion of the yoke 15a on the X1 side from the central axis α.

As shown in Figure 5, when the inclined portion 11b is provided, internal pressure from the refrigerant acts perpendicular to the Z2 side surface of the inclined portion 11b, as indicated by the solid arrow. This internal pressure can be dispersed into a force in the Z1 direction and a force in the X1 direction, as indicated by the dashed arrow.

The inclined portion 11b reduces the force in the Z1 direction, thereby reducing the force pushing the Z2 side surface of the annular member 11 outward (in the R1 direction), thereby suppressing deformation of the annular member 11. Furthermore, because the force joining the annular member 11 to the yoke 15a is a force in the X1 direction, when a force in the X1 direction is generated by internal pressure, the force joining the annular member 11 to the yoke 15a can be increased.

The outer periphery of the annular member 11 is provided with legs 11d that protrude from a first joint 16 joined to the inner periphery of the main body 12 toward the valve body 14. This causes a moment (a rotational moment that suppresses deformation of the annular member 11) to act on the legs 11d, rotating them toward the center of the annular member 11 (direction R2) with the first joint 16 as the fulcrum. This presses the annular member 11 against the yoke 15a, causing it to abut against the yoke 15a. Furthermore, the internal pressure acting on the legs 11d is the same as, but in the opposite direction to, the internal pressure acting on the legs 11d, which are positioned symmetrically about the central axis α of the yoke 15a. Therefore, the forces cancel each other out, and the internal pressure acting on the legs 11d toward the outer periphery does not deform the annular member 11.

As shown in FIG. 6, a moment (a rotational moment that suppresses deformation of the annular member 11) acts on the portion where the yoke 15a and the inclined portion 11b abut (second joint portion 17) toward the yoke 15a, as indicated by the arrow, with the end of the inclined portion 11b on the valve body 14 side (Z2 side) as the fulcrum P. This moment prevents the annular member 11 from being deformed by separating from the yoke 15a. Because the moment increases as the length L1 of the abutment point between the yoke 15a and the annular member 11 increases, it is preferable that the inclined portion 11b be configured to incline up to the end of the yoke 15a on the valve body 14 side. Note that while FIG. 6 is a cross-sectional view taken along the X direction, the annular member 11 has the same structure as in FIG. 6 when viewed along the Y direction.

(Effects of the first embodiment)
In the first embodiment, the following effects can be obtained.

In the first embodiment, the electronic expansion valve 1 is an electronic expansion valve 1 used in a refrigeration cycle 100a in which a refrigerant circulates, and includes a housing 20 including an annular member 11 that forms a flow path through which the refrigerant passes and a main body 12 that abuts against the outer peripheral surface 11c of the annular member 11; a valve seat 13 that includes a through-hole 13a that allows the refrigerant to pass through; a valve element 14 that is arranged opposite the valve seat 13 and is configured to move relative to the valve seat 13 to switch the through-hole 13a between a closed state and an open state; and a yoke 16 that is arranged opposite the valve element 14. The valve seat 13 includes a yoke 15a and a coil 15b that generates a magnetic force in the yoke 15a, and a moving mechanism 15 that moves the valve element 14 relative to the valve seat 13 using the magnetic force. The annular member 11 has a central hole 11a around which the yoke 15a is joined, and includes an inclined portion 11b that slopes toward the valve element 14 as it moves from the outer peripheral surface of the annular member 11 toward the inner peripheral surface thereof in a cross-sectional view taken along the movement direction of the valve element 14, so that the internal pressure caused by the refrigerant is received as a force toward the center where the yoke 15a is located. By providing the inclined portion 11b, the internal pressure caused by the refrigerant can be divided into an outward force and a force toward the center, thereby reducing the outward force. This allows the direction of the internal pressure acting on the inclined portion 11b to be dispersed into a force toward the center of the annular member 11 where the yoke 15a is located, and a force from the valve element 14 side toward the yoke 15a, which is perpendicular to the direction toward the center. This reduces the force acting from the valve body 14 toward the yoke 15a, thereby reducing the force that pushes the annular member 11 from the valve body 14 toward the yoke 15a and deforms it. Furthermore, because the annular member 11 can be pressed against the yoke 15a by a force acting toward the center, there is no need to increase the bonding strength between the annular member 11 and the yoke 15a. As a result, the device configuration can be simplified while preventing deformation of the housing 20 (annular member 11).

In addition, in the first embodiment, a portion of the outer peripheral surface 11c of the annular member 11 that abuts the main body portion 12 is joined to the inner peripheral surface of the main body portion 12, and the outer peripheral surface 11c of the annular member 11 abuts the main body portion 12 from the portion joined to the inner peripheral surface of the main body portion 12 toward the valve body so that the internal pressure from the refrigerant is received as a force toward the outer circumference of the annular member 11. As a result, when the internal pressure of the refrigerant acts on the outer peripheral surface 11c of the annular member 11, a rotational moment acts on the annular member 11 around the joint between the annular member 11 and the main body portion 12 in the direction opposite to the direction moving the annular member 11 away from the yoke 15a, suppressing deformation of the annular member 11. This prevents the housing 20 (annular member 11) from deforming in the direction away from the yoke 15a.

In addition, in the first embodiment, the outer periphery of the annular member 11 is provided with legs 11d that protrude from the portion joined to the inner periphery of the main body 12 toward the valve body 14. Providing the legs 11d increases the area of the outer periphery 11c of the annular member 11 on which the internal pressure of the refrigerant acts, thereby increasing the rotational moment that suppresses deformation of the annular member 11 around the joint between the annular member 11 and the main body 12. As a result, deformation of the housing 20 (annular member 11) in a direction away from the yoke 15a can be further suppressed.

In addition, in the first embodiment, the annular member 11 includes an inclined portion 11b. When viewed in a cross-sectional view along the movement direction of the valve disc 14, the length of the inclined portion 11b abutting against the yoke 15a along the movement direction of the valve disc 14 is longer than the length of the portion of the annular member 11 along the movement direction of the valve disc 14 where the inclined portion 11b is not provided, excluding the outer periphery of the annular member 11. This increases the length of the inclined portion 11b along the movement direction of the valve disc 14, thereby increasing the contact area between the annular member 11 and the yoke 15a and making it less likely for the annular member 11 to separate from the yoke 15a. Furthermore, if a joint portion is provided at one end of the contact portion between the yoke 15a and the inclined portion 11b, the distance from the end where the joint portion is provided to the other end where the joint portion is not provided increases, thereby increasing the rotational moment that suppresses deformation of the annular member 11, with the other end of the contact portion between the yoke 15a and the inclined portion 11b as a fulcrum. As a result, the annular member 11 can be pressed against the yoke 15a joined to the center of the annular member 11, preventing the housing 20 (annular member 11) from deforming in a direction away from the yoke 15a.

In the first embodiment, the inclined portion 11b is configured to incline up to the vicinity of the end of the yoke 15a on the valve body 14 side. This allows the distance from the end with the inclined portion 11b to the other end without the inclined portion to approach its maximum value when a joint is located at one end of the contact area between the yoke 15a and the inclined portion 11b. This reliably increases the contact area between the annular member 11 and the yoke 15a and makes it even more difficult for the housing 20 (annular member 11) to separate from the yoke 15a. Furthermore, the distance from the end with the inclined portion to the other end without the inclined portion can be maximized, allowing the rotational moment that suppresses deformation of the annular member 11, with the other end of the contact area between the yoke 15a and the inclined portion 11b as a fulcrum, to approach its maximum value. As a result, the annular member 11 can be strongly pressed against the yoke 15a, which is joined to the center of the annular member 11, effectively suppressing deformation of the housing 20 (annular member 11) away from the yoke 15a.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to Figures 1, 2, and 7 to 9. In this second embodiment, an example will be described in which a first protrusion 11e is provided on an annular member 111, unlike the annular member 11 of the first embodiment. Note that the same components as those in the first embodiment will be denoted by the same reference numerals and will not be described again. Note that Figures 8 and 9 are enlarged views of a portion of the yoke 15a on the X1 side from the central axis α.

As shown in Figure 7, the annular member 111 includes a first protrusion 11e that protrudes the inner circumferential surface that contacts the yoke 15a toward the valve body 14 so that the internal pressure of the refrigerant is received as a force toward the center where the yoke 15a is located. Note that while Figure 7 is a cross-sectional view taken along the X direction, the annular member 111 has the same structure as in Figure 7 when viewed along the Y direction.

As shown in Figure 8, the length L3 of the first protrusion 11e abutting against the yoke 15a along the movement direction (Z direction) of the valve element 14 (see Figure 7) is configured to be greater than the length L4 of the portion of the annular member 111 where the first protrusion 11e is not provided, excluding the outer periphery, along the movement direction (Z direction) of the valve element 14. It is also preferable that the first protrusion 11e be configured to protrude up to near the end of the yoke 15a on the valve element 14 side (Z2 side). Note that while Figure 8 is a cross-sectional view taken along the X direction, the annular member 111 has the same structure as in Figure 8 when viewed along the Y direction.

As shown in Figure 8, when the first protrusion 11e is provided, internal pressure from the refrigerant acts on the first protrusion 11e in the X1 direction, as indicated by the arrow. Because the force joining the annular member 111 to the yoke 15a is a force in the X1 direction, when a force in the X1 direction is generated by the internal pressure, the force joining the annular member 111 to the yoke 15a can be increased.

As shown in FIG. 9, at the portion where the yoke 15a and the first protrusion 11e abut (second joint 17), a moment is generated that rotates the first protrusion 11e toward the yoke 15a, as indicated by the arrow, with the end of the first protrusion 11e on the valve body 14 side (Z2 side) as the fulcrum P. This moment prevents the annular member 111 from separating from the yoke 15a and deforming. Because the moment increases as the length L3 of the abutment point between the yoke 15a and the annular member 111 increases, it is preferable that the first protrusion 11e be configured to protrude close to the end of the yoke 15a on the valve body 14 side (Z2 side). Note that while FIG. 9 is a cross-sectional view taken along the X direction, the annular member 111 has the same structure as that shown in FIG. 9 when viewed along the Y direction.

(Effects of the second embodiment)
In the second embodiment, the following effects can be obtained.

In the second embodiment, as described above, the electronic expansion valve 1 is used in a refrigeration cycle 100a in which a refrigerant circulates, and includes a housing 20 including an annular member 111 that forms a flow path through which the refrigerant passes and a main body 12 that abuts against the outer peripheral surface 11c of the annular member 111; a valve seat 13 that includes a through-hole 13a that allows the refrigerant to pass; a valve element 14 that is disposed opposite the valve seat 13 and is configured to move relative to the valve seat 13 to switch the through-hole 13a between a closed state and an open state; and The valve seat 13 includes a yoke 15a arranged to face the valve seat 13, a coil 15b that generates a magnetic force in the yoke 15a, and a movement mechanism 15 that uses the magnetic force to move the valve element 14 relative to the valve seat 13. The annular member 111 has an inner circumferential surface surrounding a central hole 11a to which the yoke 15a is joined, and a first protrusion 11e that protrudes from the inner circumferential surface that abuts the yoke 15a toward the valve element 14 so that the internal pressure of the refrigerant acts on the first protrusion 11e toward the valve element 14. Because the first protrusion 11e protrudes toward the valve element 14, the internal pressure of the refrigerant acts on the first protrusion 11e as a force toward the center of the annular member 11. This allows the annular member 11 to be pressed against the yoke 15a by the force toward the center, eliminating the need for increased bond strength between the annular member 11 and the yoke 15a. This simplifies the device configuration while preventing deformation of the housing 20 (annular member 111).

Furthermore, in the second embodiment, as described above, the annular member 111 includes the first protrusion 11e, and is configured so that, when viewed in a cross-sectional view along the movement direction of the valve disc 14, the length L3 of the first protrusion 11e abutting against the yoke 15a along the movement direction of the valve disc 14 is greater than the length L4 of the portion of the annular member 111 along the movement direction of the valve disc 14 where the first protrusion 11e is not provided, excluding the outer periphery. This allows the length L3 of the first protrusion 11e along the movement direction of the valve disc 14 to be increased, thereby increasing the contact area between the annular member 111 and the yoke 15a and making it difficult for the housing 20 (annular member 111) to separate from the yoke 15a. Furthermore, if a joint is located at one end of the contact area between the yoke 15a and the first protrusion 11e as viewed in the direction of movement of the valve disc, the distance from the end where the joint is located to the other end where no joint is located becomes greater, thereby increasing the rotational moment that acts on the other end of the contact area between the yoke 15a and the first protrusion 11e as a fulcrum and suppresses deformation of the annular member 111. As a result, the annular member 111 can be pressed against the yoke 15a joined to the center of the annular member 111, suppressing deformation of the housing 20 (annular member 111) in a direction away from the yoke 15a.

In the second embodiment, as described above, the first protrusion 11e is configured to protrude to the vicinity of the end of the yoke 15a on the valve body 14 side. This allows the distance from the end with the joint to the other end without the joint to approach its maximum value when a joint is located at one end of the abutment between the yoke 15a and the first protrusion 11e. This reliably increases the contact area between the first protrusion 11e and the yoke 15a and makes it even more difficult for the housing 20 (annular member 111) to separate from the yoke 15a. Furthermore, the distance from the end with the joint to the other end without the joint can be maximized, allowing the rotational moment that suppresses deformation of the annular member 111, with the other end of the abutment between the yoke 15a and the first protrusion 11e as a fulcrum, to approach its maximum value. As a result, the annular member 111 can be pressed firmly against the yoke 15a joined to the center of the annular member 111, effectively preventing the housing 20 (annular member 111) from deforming in a direction away from the yoke 15a.

[Modification]
The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

For example, in the first and second embodiments described above, an example was shown in which the refrigeration cycle was used in a showcase, but the present invention is not limited to this. In the present invention, the refrigeration cycle may also be used in an air conditioning device, etc.

Furthermore, in the first and second embodiments described above, an example was shown in which the object to be cooled was air, but the present invention is not limited to this. In the present invention, the object to be cooled may also be a liquid.

In addition, in the first and second embodiments described above, examples were shown in which legs were provided on the annular member, but the present invention is not limited to this. In the present invention, the annular member does not necessarily have to have legs.

In addition, while the first and second embodiments above show examples in which the annular member and the housing are joined, the present invention is not limited to this. In the present invention, the annular member and the housing do not need to be joined as long as they are in contact with each other.

In addition, while the first and second embodiments above show examples in which the annular member and the yoke are joined, the present invention is not limited to this. In the present invention, the annular member and the yoke do not need to be joined as long as they are in contact with each other.

1 Electronic expansion valve 11, 111 Annular member 11a Hole portion 11b Inclined portion 11c Outer circumferential surface 11d Leg portion (second protrusion)
11e First protrusion 12 Main body 13 Valve seat 14 Valve element 15 Moving mechanism 15a Yoke 15b Coil 20 Housing 100a Refrigeration cycle

Claims (7)

An electronic expansion valve used in a refrigeration cycle in which a refrigerant circulates,
a housing including an annular member that forms a flow path through which a refrigerant passes, and a main body that abuts on an outer circumferential surface of the annular member;
a valve seat including a through hole for passing a refrigerant;
a valve body disposed opposite the valve seat and configured to move relative to the valve seat to switch the through hole between a closed state and an open state;
a moving mechanism including a yoke arranged to face the valve body and a coil that generates a magnetic force in the yoke, and that moves the valve body relative to the valve seat by the magnetic force;
the annular member has an inner circumferential surface surrounding a hole provided in the center, to which the yoke is joined, and the annular member includes an inclined portion that inclines toward the valve body from the outer circumferential surface side of the annular member toward the inner circumferential surface side when viewed in a cross section along the movement direction of the valve body, or a first protruding portion that causes the inner circumferential surface abutting against the yoke to protrude toward the valve body, so that the annular member receives internal pressure due to the refrigerant as a force toward the center where the yoke is disposed. The electronic expansion valve of claim 1, wherein a portion of the outer peripheral surface of the annular member that abuts the main body portion is joined to the inner peripheral surface of the main body portion, and the outer peripheral surface of the annular member abuts the main body portion from the portion joined to the inner peripheral surface of the main body portion toward the valve body so that the annular member receives internal pressure from the refrigerant as a force directed toward the outer periphery of the annular member. An electronic expansion valve as described in claim 2, wherein the outer periphery of the annular member is provided with a second protrusion that protrudes from the portion joined to the inner periphery of the main body toward the valve body. The electronic expansion valve according to any one of claims 1 to 3, wherein the annular member includes the inclined portion, and when viewed in a cross-sectional view along the movement direction of the valve disc, the length of the inclined portion abutting the yoke along the movement direction of the valve disc is greater than the length along the movement direction of the valve disc of the portion of the annular member that does not have the inclined portion, excluding the outer periphery. The electronic expansion valve described in claim 4, wherein the inclined portion is configured to incline up to near the end of the yoke on the valve body side. The electronic expansion valve described in any one of claims 1 to 3, wherein the annular member includes the first protrusion, and is configured such that, when viewed in a cross-sectional view along the movement direction of the valve disc, the length of the first protrusion abutting against the yoke along the movement direction of the valve disc is greater than the length of a portion of the annular member, excluding the outer periphery, that does not have the first protrusion along the movement direction of the valve disc. The electronic expansion valve described in claim 6, wherein the first protrusion is configured to protrude to the vicinity of the end of the yoke on the valve body side.