Electric valves and refrigeration cycle systems

Abstract

The present invention provides an electric valve that allows for easy installation of a sound-absorbing member, and a refrigeration cycle system equipped with the electric valve. [Solution] The outer peripheral valve closing side surface 251, which is located on the outer circumference side of the sound-absorbing member 7 and faces away from the valve seat 24, is spaced apart from the tip surface 111 of the joint pipe 11. This makes it difficult for the molten brazing material to reach the outer peripheral valve closing side surface 251 after passing between the joint pipe 11 and the main body 20A, and prevents the sound-absorbing member 7 from being blocked even when brazing is performed after the sound-absorbing member 7 is attached, making it easy to install the sound-absorbing member 7.

Description

Technical Field

[0001] The present invention relates to an electric valve and a refrigeration cycle system.

Background Art

[0002] Conventionally, as an electric valve that adjusts the opening degree of a valve port by moving a valve body forward and backward, a noise reduction device has been proposed to be arranged between a valve seat member formed with a valve port and a joint pipe connected to the valve body (see, for example, Patent Document 1). In the electric valve described in Patent Document 1, by providing a mesh-like noise reduction device, bubbles of the passing fluid are decomposed to reduce noise.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When joining a joint pipe to a valve body in an electric valve, joining by brazing may be adopted. However, in an electric valve in which a noise reduction member is arranged in the vicinity of the joint pipe as described in Patent Document 1, the melted brazing material may block the holes of the noise reduction member, which may cause problems in flow rate characteristics and the like. Therefore, although a method of arranging the noise reduction member after brazing the joint pipe is conceivable, it is necessary to attach the noise reduction member so that it passes through the joint pipe, and the workability is likely to decrease.

[0005] An object of the present invention is to provide an electric valve capable of easily providing a noise reduction member and a refrigeration cycle system including the electric valve.

Means for Solving the Problems

[0006] The electric valve of the present invention comprises a valve body having a cylindrical portion and constituting a valve chamber and a valve port; a valve element that adjusts the opening area between the valve port and the valve seat by moving back and forth in the axial direction; and a coupling pipe connected to the opening in the cylindrical portion on the valve-closed side of the valve seat, wherein the electric valve comprises a sound-absorbing member positioned on the valve-closed side of the valve seat, the coupling pipe is inserted through the opening and joined to the cylindrical portion by brazing material provided on the outer circumference, the inner side of the cylindrical portion is provided with an outer valve-closed side surface located on the outer circumference side of the sound-absorbing member and facing away from the valve seat in the axial direction, and the outer valve-closed side surface is separated from the tip surface of the coupling pipe at least at the boundary with the inner circumference surface of the cylindrical portion.

[0007] As described above, the present invention ensures that the outer valve closing surface is separated from the tip surface of the joint pipe at least at the boundary with the inner surface of the cylindrical portion. This makes it difficult for the molten brazing material to reach the outer valve closing surface after passing between the joint pipe and the cylindrical portion. This prevents the sound-absorbing member from being blocked even when brazing is performed after the sound-absorbing member is attached, and makes it easier to install the sound-absorbing member.

[0008] In this case, it is preferable that the electric valve of the present invention has a valve seat member that is separate from the cylindrical portion and has the valve seat and valve port formed therein, and that the valve seat member has the outer peripheral valve closing surface and that its outer peripheral portion is fitted and fixed to the cylindrical portion. With such a configuration, the degree of freedom in setting the position of the outer peripheral valve closing surface with respect to the tip surface of the joint pipe can be improved. In addition, the outer peripheral valve closing surface to which the sound-absorbing member is joined is formed as a separate part from the cylindrical portion, and the brazing material that passes between the joint pipe and the cylindrical portion is less likely to adhere to the outer peripheral valve closing surface or the sound-absorbing member.

[0009] Furthermore, in the electric valve of the present invention, the valve seat member has a press-fit portion and an insertion portion that is smaller in diameter than the press-fit portion and positioned on the valve-closed side, and it is preferable that a radial gap is formed between the insertion portion and the inner circumferential surface of the cylindrical portion, so that the outer valve-closed side surface is separated from the tip surface of the joint pipe over a predetermined range from the boundary portion to the inner circumferential side. With such a configuration, brazing material can be accumulated in the gap between the insertion portion and the inner circumferential surface of the cylindrical portion. When brazing with the valve-closed side facing vertically upward, the molten brazing material moves toward the valve-open side due to gravity and flows into this gap once it reaches the valve seat member. Since the brazing material is unlikely to move toward the inner circumferential side unless it overflows from this gap, it is possible to suppress the brazing material from reaching the sound-absorbing member located on the inner circumferential side relative to the outer valve-closed side surface.

[0010] Furthermore, in the electric valve of the present invention, it is preferable that the cylindrical portion has a stepped portion at the opening such that the valve closing side has a larger diameter, and that the tip surface of the connecting pipe abuts against the stepped portion. With such a configuration, it is possible to control the insertion depth of the connecting pipe into the valve body and to easily set the distance from the outer peripheral valve closing side.

[0011] Furthermore, in the electric valve of the present invention, it is preferable that the entire outer surface of the valve closing side is separated from the tip surface of the joint member. With such a configuration, it is easier to suppress the adhesion of brazing material to the sound-absorbing member.

[0012] Furthermore, in the electric valve of the present invention, it is preferable that the cylindrical portion has a side opening, and that the valve seat is positioned on the valve-opening side relative to the central axis of the side opening. With such a configuration, by positioning the valve seat on the valve-opening side, the sound-absorbing member provided on the valve-closed side relative to the valve seat can also be positioned as close to the valve-opening side as possible, making it easier to secure the gap between the outer valve-closed side surface and the tip surface of the joint pipe.

[0013] Furthermore, the electric valve of the present invention further comprises a guide portion having a guide hole through which the valve body is inserted and which guides the valve body in the axial direction, and it is preferable that the valve-closed end of the guide portion is positioned on the valve-open side than the valve-open end of the side opening. With such a configuration, the fluid flowing into the valve chamber from the side opening is less likely to directly collide with the guide portion, and the noise of refrigerant passage can be suppressed.

[0014] Furthermore, in the electric valve of the present invention, it is preferable that the sound-absorbing member is formed in a mesh shape and has through holes extending along the axial direction. With such a configuration, it is possible to form a flow path through the mesh portion and a flow path through the through holes in the sound-absorbing member, thereby enabling sound absorption while ensuring a passable flow rate.

[0015] The refrigeration cycle system of the present invention is a refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, characterized in that an electric valve described in any of the above is used as the expansion valve. According to the present invention as described above, a sound-absorbing member can be easily provided as described above. [Effects of the Invention]

[0016] According to the electric valve and refrigeration cycle system of the present invention, a sound-absorbing member can be easily provided. [Brief explanation of the drawing]

[0017] [Figure 1] This is a cross-sectional view showing an electric valve according to a first embodiment, which is an example of the present invention. [Figure 2] This is a cross-sectional view showing an enlarged view of the main part of the aforementioned electric valve. [Figure 3] This is a system diagram showing a refrigeration cycle system equipped with the aforementioned electric valve. [Figure 4] This is an enlarged cross-sectional view showing the main part of an electric valve according to a second embodiment, which is an example of the present invention. [Figure 5] This is an enlarged cross-sectional view showing the main part of the electric valve according to the first modified example. [Figure 6] It is a cross-sectional view showing an enlarged main part of an electric valve according to a second modification example. [Figure 7] It is a cross-sectional view showing an enlarged main part of an electric valve according to a third modification example. [Figure 8] It is a cross-sectional view showing an enlarged main part of an electric valve according to a fourth modification example. [Figure 9] It is a cross-sectional view showing an enlarged main part of an electric valve according to a fifth modification example. [Figure 10] It is a cross-sectional view showing an enlarged main part of an electric valve according to a sixth modification example. [Figure 11] It is a cross-sectional view showing an enlarged main part of an electric valve according to a seventh modification example.

Embodiments for Carrying Out the Invention

[0018] [First Embodiment] The first embodiment of the present invention will be described with reference to the drawings. The electric valve 1 of this embodiment is used in a refrigeration cycle system of an air conditioner such as a package air conditioner or a room air conditioner as shown in FIG. 1, and includes a valve body 2, a valve element 3, a support member 4, a stepping motor 5, a guide portion 6, and a sound absorbing member 7.

[0019] The valve body 2 is composed of a main body portion 20A, an upper lid 20B, and a valve seat member 20C. The upper lid 20B is fixed to the upper end portion of the main body portion 20A described later by brazing. The main body portion 20A is a cylindrical portion formed in a cylindrical shape, and the valve element 3 is accommodated in the valve chamber 2A inside thereof. Hereinafter, the axial direction of the main body portion 20A is defined as the Z direction, and the two directions orthogonal to the Z direction are defined as the X direction and the Y direction, respectively. Also, hereinafter, the up and down in the Z direction are based on FIG. 1, the upper side (the side of the screw feed mechanism 55 with respect to the valve port 23) is the valve open side, and the lower side (the side of the valve port 23 with respect to the screw feed mechanism 55) is the valve closed side.

[0020] As shown in Figure 2, the main body 20A has a cylindrical opening 21 that opens in the Z direction on the valve closing side of the valve port 23 (described later), and a side opening 22 that opens on the side. The connecting pipes 11 and 12 are inserted through and connected to the openings 21 and 22, respectively. The connecting pipes 11 and 12 are joined to the main body 20A by brazing.

[0021] The valve seat member 20C is separate from the main body 20A, meaning it is a separate component fixed by press-fitting. Specifically, the outer circumference of the valve seat member 20C is fitted and fixed to the main body 20A, which is a cylindrical part. The valve seat member 20C has a valve port 23 and a valve seat (seal portion) 24 on which the valve body 3 sits or separates, and the joint pipe 12 is in communication with the valve port 23.

[0022] The valve body 3 comprises a valve body member 31 and a valve holder 32. The valve body member 31 is fitted and suspended from the valve holder 32, extends downward from the valve holder 32, and has a needle valve 311 at its tip. The needle valve 311 seats or separates from the valve seat 24.

[0023] The valve holder 32 is formed in a cylindrical shape extending along the Z direction, and its upper end is engaged with the lower end of the rotor shaft 51 of the stepping motor 5, which will be described later. That is, the valve holder 32 is suspended by the rotor shaft 51 and is rotatable relative to the rotor shaft 51. A compression coil spring 33 is also provided inside the valve holder 32, and a downward (valve closed) load is applied to the valve body member 31. For the sake of explanation, the compression coil spring 33 is omitted in Figures 1 and 2 by a dashed line.

[0024] The support member 4 is fixed to the upper cover 20B at the flange portion 41 so as to close the upper opening of the upper cover 20B of the valve body 2. The support member 4 has a guide recess 42 that accommodates the valve holder 32 and guides it in the Z direction, and a female thread portion 43 into which the rotor shaft 51 is screwed.

[0025] The stepping motor 5 consists of a rotor shaft 51, a case 52, a magnet rotor 53, and a stator coil 54. A magnet rotor 53, whose outer circumference is magnetized with multiple poles, is rotatably mounted inside the case 52, and the rotor shaft 51 is fixed to this magnet rotor 53. Furthermore, the case 52 is fixed to the top cover 20B of the valve body 2 so as to close the upper opening of the top cover 20B. The stator coil 54 is arranged on the outer circumference of the case 52. The stepping motor 5 rotates the magnet rotor 53 according to the number of pulses when a pulse signal is applied to the stator coil 54.

[0026] A male threaded portion 511 is formed on the outer circumferential surface of the rotor shaft 51, which engages with the female threaded portion 43 of the support member 4. When the stepping motor 5 is driven, the magnet rotor 53 and rotor shaft 51 rotate, and the screw feed mechanism 55, which is composed of the male threaded portion 511 and the female threaded portion 43, moves the rotor shaft 51 in the Z direction. As a result, the valve holder 32 suspended from the rotor shaft 51 moves in the Z direction, guided by the guide recess 42 of the support member 4, causing the needle valve 311 of the valve body member 31 to seat or separate from the valve seat 24, and the valve port 23 to open and close. The opening degree of the valve port 23 is controlled according to the position (lift amount) of the valve body member 31 in the Z direction, and the flow rate of the fluid flowing through the valve port 23 is controlled.

[0027] As described above, the electric valve 1 includes a stepping motor 5 as a rotational driving means and a screw feed mechanism 55 that moves the valve body 3 axially forward and backward by converting the rotational motion of the rotor shaft 51 into linear motion.

[0028] The guide portion 6 is fixed to the upper opening of the main body portion 20A. The guide portion 6 is formed in a cylindrical shape as a whole and has a guide hole 61, which is a through hole extending in the Z direction. The valve body member 31 of the valve body 3 is inserted through the guide hole 61 and can be guided in the Z direction. The guide portion 6 divides the valve chamber 2A and the back pressure chamber, which is the space above the valve chamber 2A and below the screw feeding mechanism 55, while connecting these spaces through a pressure equalization hole (not shown).

[0029] The sound-absorbing member 7 is provided on the valve closed side with respect to the valve port 23. The sound-absorbing member 7 is a filter formed in a three-dimensional mesh shape by randomly bending linear members, and can be, for example, a demister. The sound-absorbing member 7, formed in this mesh shape, functions to subdivide the flow path, and the fluid (refrigerant) passes through the sound-absorbing member 7 while being subdivided. That is, when a gas-liquid mixed fluid passes through the sound-absorbing member 7, the bubbles are subdivided. At this time, because the linear members of the sound-absorbing member 7 are randomly bent, it has passage areas of various sizes through which the fluid can pass. Also, when the fluid passes through the sound-absorbing member 7 along a predetermined direction of passage, the passage area changes depending on the position in the direction of passage. As a result, bubbles of various sizes are subdivided.

[0030] Here, we will describe the details of the surrounding structure of the sound-absorbing member 7 in the electric valve 1. First, the sound-absorbing member 7 is fixed to the valve seat member 20C. The valve seat member 20C has an annular valve seat body 25 that is press-fitted into the main body 20A, and a cylindrical valve seat tubular portion 26 that extends from the center of the valve seat body 25 toward the valve opening side. The valve seat body 25 has an outer peripheral valve closing side surface 251 that extends along the XY plane toward the valve closing side (i.e., the opposite side from the valve seat 24 described later in the Z direction). A recess 251A is formed in the center of the outer peripheral valve closing side surface 251 so as to embed a part of the sound-absorbing member 7, and the sound-absorbing member 7 can be fixed by crimping it with a protruding portion 251B that protrudes from the outer peripheral valve closing side surface 251, for example, via a ring-shaped member. The outer peripheral valve closing side surface 251 is located on the outer circumference side of the sound-absorbing member 7 that is fixed in this way.

[0031] A valve seat 24 is provided at the upper end of the valve seat cylindrical portion 26, and the valve port 23 is formed extending from the valve seat cylindrical portion 26 to the valve seat body portion 25. In other words, compared to a configuration in which no valve seat cylindrical portion is formed, the valve seat 24 is positioned on the valve opening side by the height of the valve seat cylindrical portion 26. The valve seat 24 is positioned on the valve opening side of the central axis O1 of the side opening 22 (i.e., the central axis of the joint pipe 12).

[0032] The main body 20A has a stepped portion 204 in the cylindrical opening 21, and the stepped portion 204 is composed of a small diameter portion 201, a large diameter portion 202 on the valve closing side of the small diameter portion 201, and a stepped surface 203 extending along the XY plane between the small diameter portion 201 and the large diameter portion 202. The joint pipe 11 is prevented from being overinserted by its tip surface 111 contacting the stepped surface 203, that is, the tip surface 111 of the joint pipe 11 is in contact with the stepped portion 204.

[0033] The stepped surface 203 is located on the valve-closed side relative to the outer peripheral valve-closed surface 251, so that the entire outer peripheral valve-closed surface 251 is separated from the end surface 111 of the joint pipe 11 in the Z direction.

[0034] The sound-absorbing member 7 is formed in a T-shape in cross-section, having an annular fixed portion 71, a cylindrical sound-absorbing cylindrical portion 72 that is smaller in diameter than the fixed portion 71 and extends toward the valve closed side, and a through hole 73 that penetrates the fixed portion 71 and the sound-absorbing cylindrical portion 72 and extends along the Z direction. The outer diameter of the sound-absorbing member 7 is smaller than the inner diameter of the main body portion 20A in the area where the sound-absorbing member 7 is placed, and the outer circumferential surface of the sound-absorbing member 7 is radially separated from the inner circumferential surface 205 of the main body portion 20A. In this embodiment, the entire fixed portion 71 is located toward the valve open side of the tip surface 111 of the joint pipe 11. Of the fixed portion 71, the portion located toward the outer circumference of the valve port 23 (especially the portion that protrudes toward the outer circumference of the sound-absorbing cylindrical portion 72) hardly allows fluid to pass through and is less likely to affect the flow characteristics.

[0035] The guide portion 6 comprises an annular main body portion 62 fixed to the main body portion 20A, and a guide cylindrical portion 63 that is continuous with the central part of the annular main body portion 62 and has a guide hole 61. The guide cylindrical portion 63 extends from the annular main body portion 62 toward the valve opening side. The valve closing side surface 62A of the annular main body portion 62 is formed in a concave shape. That is, the outer circumferential surface of the annular main body portion 62 of the guide portion 6 is the part that is located furthest toward the valve closing side. The entire guide portion 6 is located toward the valve opening side than the valve opening side end of the side opening 22, that is, the valve closing side end of the guide portion 6 is located toward the valve opening side than the valve opening side end of the side opening 22.

[0036] In the electric valve 1 described above, the valve seat member 20C and the sound-absorbing member 7 are installed in the main body 20A, and then the joint pipe 11 is connected to the cylindrical opening 21. When connecting the joint pipe 11, the brazing work is performed in such a way that the valve closed side faces upward in the vertical direction. Specifically, brazing material is placed on the tip surface 27 of the main body 20A on the side of the cylindrical opening 21 and on the outer circumference of the joint pipe 11, and this brazing material is heated and melted. The molten brazing material penetrates between the outer circumference of the joint pipe 11 and the inner circumference of the cylindrical opening 21 and moves downward in the vertical direction (valve open side).

[0037] The brazing material that reaches the tip surface 111 of the joint pipe 11 is moved vertically downward (towards the valve open side) by gravity, and only after reaching the outer valve closed side surface 251 does it move towards the inner side (towards the sound-absorbing member 7). In other words, because the tip surface 111 and the outer valve closed side surface 251 are separated, capillary action does not occur between them, making it difficult for the brazing material to move towards the sound-absorbing member 7. Furthermore, because a protrusion 251B is formed, even if the brazing material reaches it, it will not reach the sound-absorbing member 7 unless the amount of brazing material accumulated exceeds the protrusion height of the protrusion 251B.

[0038] Next, an example of a refrigeration cycle system in which the electric valve 1 of this embodiment is installed will be described based on Figure 3. This refrigeration cycle system is used, for example, in air conditioners such as household air conditioners. The electric valve 1 is installed between the indoor heat exchanger 101 and the outdoor heat exchanger 104. The electric valve 1, indoor heat exchanger 101, four-way switching valve 102, compressor 103, and outdoor heat exchanger 104 constitute a refrigeration cycle. For example, the indoor heat exchanger 101 is installed indoors, the electric valve 1 is installed in either the indoor or outdoor unit, and the four-way switching valve 102, compressor 103, and outdoor heat exchanger 104 are installed outdoors, forming a heating and cooling system. The arrangement of each part of the refrigeration cycle system is not particularly limited and can be appropriately selected according to the application and the shape of each part.

[0039] According to this embodiment, the entire outer valve closing side surface 251 is separated from the tip surface 111 of the joint pipe 11, making it difficult for the molten brazing material to reach the outer valve closing side surface 251 after passing between the joint pipe 11 and the main body 20A. This prevents the sound-absorbing member 7 from being blocked even when brazing is performed after the sound-absorbing member 7 is attached, and makes it easy to install the sound-absorbing member 7.

[0040] Furthermore, the valve seat member 20C, which has the valve seat 24 and valve port 23 and is separate from the main body 20A, has an outer peripheral valve closing side surface 251, which improves the degree of freedom in setting the position of the outer peripheral valve closing side surface 251 relative to the end surface 111 of the joint pipe 11. In addition, the outer peripheral valve closing side surface 251 to which the sound-absorbing member 7 is joined is formed as a separate part from the main body 20A, making it less likely for brazing material that has passed between the joint pipe 11 and the main body 20A to adhere to the outer peripheral valve closing side surface 251 or the sound-absorbing member 7.

[0041] Furthermore, since the tip surface 111 of the joint pipe 11 is in contact with the stepped portion 204 of the main body 20A, the insertion depth of the joint pipe 11 into the valve body 2 can be controlled, making it easier to set the distance from the outer valve closed side surface 251.

[0042] Furthermore, because the valve seat 24 is positioned on the valve-opening side relative to the central axis O1 of the side opening 22, the valve seat 24 can be positioned on the valve-opening side, and the sound-absorbing member 7, which is provided on the valve-closed side relative to the valve seat 24, can also be positioned as far to the valve-opening side as possible, making it easier to secure the gap between the outer valve-closed side surface 251 and the tip surface 111 of the joint pipe 11.

[0043] Furthermore, since the valve-closed end of the guide section 6 is positioned on the valve-open side of the side opening 22, the fluid flowing into the valve chamber 2A from the side opening 22 is less likely to directly collide with the guide section 6, thereby suppressing refrigerant passage noise.

[0044] Furthermore, since the sound-absorbing member 7 is formed in a mesh shape and has through holes 73 extending along the Z direction, the sound-absorbing member 7 can form a flow path that passes through the mesh portion and a flow path that passes through the through holes 73, thereby enabling sound absorption while ensuring a sufficient flow rate.

[0045] [Second Embodiment] In the second and subsequent embodiments, components common to the first embodiment are denoted by the same reference numerals and their descriptions are omitted. The explanation will primarily focus on the differences from the first embodiment. Components not specifically described are assumed to have the same shape and function as those in the first embodiment.

[0046] In the second embodiment, the valve seat member 20D and the sound-absorbing member 8 differ from those of the first embodiment.

[0047] The valve seat member 20D includes a valve seat body portion 25, a valve-opening side cylindrical portion 28 that is formed in a cylindrical shape extending from the central part of the valve seat body portion 25 toward the valve-opening side and is provided with a valve seat 24, and a cylindrical valve-closing side cylindrical portion 29 that extends toward the valve-closing side.

[0048] The valve seat body 25 has a press-fit portion 252, an insertion portion 253 which is smaller in diameter than the press-fit portion 252 and positioned on the valve closed side, and a stepped surface 254 formed between the press-fit portion 252 and the insertion portion 253. The press-fit portion 252 is press-fitted into the body 20A because its outer diameter is slightly larger than the inner diameter of the body 20A.

[0049] The outer diameter of the insertion portion 253 is smaller than the inner diameter of the main body portion 20A in the portion where the press-fit portion 252 is press-fitted, and a radial gap G is formed between the insertion portion 253 and the inner circumferential surface 205 of the main body portion 20A. As a result, the stepped surface 254 is located on the outer circumference side of the sound-absorbing member 8 and becomes the outer circumferential valve closing surface facing away from the valve seat 24 in the Z direction. The entire stepped surface 254 is separated from the tip surface 111 of the joint pipe 11, and the stepped surface 254 is separated from the tip surface 111 of the joint pipe 11 over a predetermined range (the entire stepped surface 254) from the boundary with the inner circumferential surface 205 of the main body portion 20A.

[0050] The lower surface 255 of the valve seat body 25, facing the valve closed side, is in contact with the tip surface 111. That is, in the first embodiment, the entire tip surface 111 of the joint pipe 11 was separated from the valve seat member 20C, but in the second embodiment, only a part of the joint pipe 11 is separated from the valve seat member 20D, that is, the stepped surface 254 as the outer peripheral valve closed side is separated from the tip surface 111 of the joint pipe 11 at the boundary with the inner peripheral surface of the main body 20A. The valve closed side cylindrical portion 29 protrudes from the lower surface 255 toward the valve closed side, so as to be separated from the inner peripheral surface of the joint pipe 11, it enters the inside of the joint pipe 11.

[0051] The valve seat member 20D has a through-hole-shaped valve port 23, and a receiving recess 23A is formed so that the opening on the valve-closed side of the valve port 23 is enlarged. The receiving recess 23A is formed across the valve seat body 25, a part of the valve-opening side cylindrical portion 28, and the valve-closed side cylindrical portion 29.

[0052] The sound-absorbing member 8 is formed in a cylindrical shape and is placed in the housing recess 23A. The sound-absorbing member 8 does not have a through hole extending along the Z direction and is solid. The sound-absorbing member 8 can be a filter, similar to the sound-absorbing member 7 in the first embodiment, and the fixing method is not particularly limited; for example, it can be the same as in the first embodiment.

[0053] According to this embodiment, the stepped surface 254, which serves as the outer peripheral valve closing surface, is separated from the tip surface 111 of the joint pipe 11 over a predetermined range from the boundary with the inner peripheral surface 205 of the main body 20A. This prevents the sound-absorbing member 8 from being blocked even when brazing is performed after the sound-absorbing member 8 is attached, and makes it easy to install the sound-absorbing member 8.

[0054] Furthermore, a radial gap G is formed between the insertion portion 253 and the inner circumferential surface 205 of the main body portion 20A, allowing the brazing material to accumulate in this gap G. When brazing with the valve closed side facing vertically upward, the molten brazing material moves toward the valve open side due to gravity, and once it reaches the valve seat member 20D, it flows into the gap G. Since the brazing material is unlikely to move toward the inner circumferential side unless it overflows from the gap G, it is possible to suppress the brazing material from reaching the sound-absorbing member 8, which is located on the inner circumferential side relative to the stepped surface 254.

[0055] It should be noted that the present invention is not limited to the first and second embodiments described above, and includes other configurations that can achieve the objectives of the present invention, and modifications such as those shown below are also included in the present invention. In each of the modifications described below, components similar to those in the above embodiments are denoted by the same reference numerals and their descriptions are omitted. In the first embodiment described above, the sound-absorbing member 7 has a through hole 73, but as shown in Figure 5, a solid sound-absorbing member 7 may be used without a through hole extending along the Z direction.

[0056] Furthermore, in the second embodiment, the sound-absorbing member 8 is not assumed to have through holes, but as shown in Figures 6 and 7, through holes 81 and 82 may be formed in the sound-absorbing member 8. The through hole 81 shown in Figure 6 has an inner diameter smaller than the inner diameter of the small-diameter portion 23B of the valve port 23, and the sound-absorbing member 8 protrudes inward relative to the small-diameter portion 23B. In contrast, the through hole 82 shown in Figure 7 has an inner diameter approximately equal to the inner diameter of the small-diameter portion 23B of the valve port 23, and these inner surfaces form a continuous cylindrical surface.

[0057] Furthermore, in the first embodiment, the sound-absorbing member 7 has an annular fixed portion 71 and a cylindrical sound-absorbing cylindrical portion 72, but the sound-absorbing cylindrical portion does not have to be formed, and as shown in Figures 8 and 9, the sound-absorbing member 7 may have only the fixed portion 71. In the modified example shown in Figure 8, a through hole 73 is formed in the fixed portion 71, similar to the first embodiment, but in the modified example shown in Figure 9, no through hole is formed in the fixed portion 71.

[0058] Furthermore, the shape of the sound-absorbing member is not limited to the shapes of the sound-absorbing member 7 shown in the first embodiment, the sound-absorbing member 8 shown in the second embodiment, or the sound-absorbing members of each of the above modified examples. For example, a cup-shaped sound-absorbing member 9 may be used as shown in Figures 10 and 11. In the modified example shown in Figure 10, the sound-absorbing member 9 has an annular fixed portion 91 and a cup portion 92. The fixed portion 91 is the same part as the fixed portion 71 in the first embodiment. The cup portion 92 has a cylindrical portion 921 that is continuous with the fixed portion 91 and extends along the Z direction, and a hemispherical curved portion 922 that is continuous with the valve closed side of the cylindrical portion 921 and whose dimensions in the XY plane decrease as it approaches the valve closed side.

[0059] The sound-absorbing member 9 has a cup portion 92 as described above, which forms a space 9A inside it. The cylindrical portion 921 has a through hole 921A extending in the direction along the XY plane, and the curved portion 922 has a through hole 922A extending in the Z direction. In the modified example shown in Figure 11, neither the cylindrical portion 921 nor the curved portion 922 has through holes.

[0060] Furthermore, in the first and second embodiments, valve seat members 20C and 20D are provided separately from the main body portion 20A, which is a cylindrical portion. However, in the valve body that constitutes the valve chamber and valve port, the valve seat and valve port may be formed integrally with the cylindrical portion, and in particular, the valve seat and valve port may be formed as a single component with the cylindrical portion.

[0061] Furthermore, in the first embodiment, the main body portion 20A, which is a cylindrical portion, has a stepped portion 204, and the tip surface 111 of the joint pipe 11 is in contact with the stepped portion 204. However, the cylindrical portion does not have to have a stepped portion, and the insertion depth of the joint pipe may be controlled by other appropriate methods to separate the outer valve closed side surface from the tip surface of the joint pipe.

[0062] Furthermore, in the first embodiment, the valve seat 24 is positioned on the valve-open side of the central axis O1 of the side opening 22, but the valve seat may be positioned at the same height as the central axis of the side opening or on the valve-close side. With such a configuration, the change in the seating position of the valve body relative to the valve seat can be reduced compared to the conventional structure, and the change in flow characteristics can be reduced.

[0063] Furthermore, in the first embodiment, the valve-closed end of the guide portion 6 is positioned on the valve-open side of the side opening 22, but the valve-closed end of the guide portion may be positioned at the same height as the valve-open end of the side opening, or positioned on the valve-closed side. With such a configuration, the Z-direction dimension of the guide portion can be increased, making it easier to secure the length necessary to guide the valve body.

[0064] Furthermore, although the first and second embodiments exemplified mesh-like sound-absorbing members 7 and 8, the sound-absorbing member can be any member capable of reducing noise by subdividing bubbles. For example, it may be a member that forms through-holes in a wall portion through which fluid cannot pass, thereby subdividing bubbles.

[0065] Furthermore, in the first embodiment, the needle valve 311 of the valve body member 31 is capable of seating against the valve seat 24, but in the electric valve, the valve body may not seat even when it is closest to the valve seat, and a predetermined flow path area gap may be formed between the valve seat and the needle valve.

[0066] Although embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and any design changes, etc., that do not depart from the spirit of the present invention are also included. [Explanation of symbols]

[0067] 1…Electric valve, 2…Valve body, 2A…Valve chamber, 20A…Main body (cylindrical part), 20C, 20D…Valve seat member, 21…Cylindrical opening (opening), 22…Side opening, 23…Valve port, 24…Valve seat, 251…Outer circumference valve closed side, 252…Pressed-in part, 253…Insertion part, 254…Stepped surface (outer circumference valve closed side), 204…Stepped part, 205…Inner circumference surface, 3…Valve body, 6…Guide part, 61…Guide hole, 7~9…Sound-absorbing member, 73, 81, 82, 921A, 922A…Through hole, 11…Joint pipe, 111…Tip surface, G…Gap, O1…Center axis

Claims

1. An electric valve comprising: a valve body having a cylindrical portion and forming a valve chamber and a valve port; a valve element that adjusts the opening area between the valve seat of the valve port by moving back and forth in the axial direction; and a coupling pipe connected to the opening on the valve-closed side of the cylindrical portion than the valve seat, The valve seat is equipped with a sound-absorbing member positioned on the valve closing side, The aforementioned joint pipe is inserted through the opening and joined to the cylindrical portion by brazing material provided on its outer circumference. An outer peripheral valve closing surface is provided on the inside of the cylindrical portion, which is located on the outer peripheral side of the sound-absorbing member and faces the opposite side from the valve seat in the axial direction. The electric valve is characterized in that the outer peripheral valve closing surface is separated from the tip surface of the joint pipe at least at the boundary with the inner peripheral surface of the cylindrical portion.

2. The valve seat and the valve port are formed therein, and a valve seat member separate from the cylindrical portion is provided, The electric valve according to claim 1, characterized in that the valve seat member has the outer peripheral valve closing surface and its outer peripheral portion is fitted and fixed to the cylindrical portion.

3. The valve seat member has a press-fit portion and an insertion portion that is smaller in diameter than the press-fit portion and positioned on the valve closing side. The electric valve according to claim 2, characterized in that a radial gap is formed between the insertion portion and the inner circumferential surface of the cylindrical portion, so that the outer circumferential valve closing surface is separated from the tip surface of the joint pipe over a predetermined range from the boundary portion to the inner circumferential side.

4. The electric valve according to claim 1, characterized in that the cylindrical portion has a stepped portion at the opening such that the valve closed side has a larger diameter, and the tip surface of the joint pipe abuts against the stepped portion.

5. The electric valve according to claim 1, characterized in that the entire outer peripheral valve closing surface is separated from the tip surface of the joint member.

6. The cylindrical portion has a side opening that is open on the side, The electric valve according to claim 1, characterized in that the valve seat is positioned on the valve opening side of the central axis of the side opening.

7. The valve body is further provided with a guide portion having a guide hole through which the valve body is inserted and which guides the valve body in the axial direction, The electric valve according to claim 6, characterized in that the valve-closed end of the guide portion is positioned on the valve-opening side of the valve-opening end of the side opening.

8. The electric valve according to claim 1, characterized in that the sound-absorbing member is formed in a mesh shape and has through holes extending along the axial direction.

9. A refrigeration cycle system comprising a compressor, a condenser, an expansion valve, and an evaporator, wherein the electric valve described in any one of claims 1 to 8 is used as the expansion valve.

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