Electric valve

Abstract

An electric motor (41) having a rotor (43) and a stator (42) that drive the valve body; a housing (40) that accommodates the rotor on the inside thereof and has the stator disposed on the outside thereof; and a connection member (21) that connects the housing and the valve body. The valve body (12) has a valve chamber (13) that communicates with an inflow passage (15) and an outflow passage (16). The valve body (17) moves forward and backward with respect to a valve seat (14). The electric motor (41) has a rotor (43) and a stator (42) that drive the valve body (17). And a sealing member (30) extending so as to surround the connecting member and abutting against the outer peripheral surface of the connecting member and the inner peripheral surface of a housing (56) of the motor in a pressed state, the connecting member being formed by press working and having a cylindrical portion (22) in which a rigid member (31) is inserted, and the sealing member (30) being formed by pressing the rigid member (31) in the direction of the axis (A) of the electrically operated valve. The cylindrical portion, the rigid member, and the sealing member are disposed so as to overlap each other.

Description

Technical Field

[0001] The present invention relates to an electric valve, and more particularly to a structure of a connection portion connecting a valve body to an electric motor. Background Art

[0002] Conventionally, electric valves that control the valve opening using an electric motor such as a stepping motor have been used in refrigeration cycle devices including a refrigerant circuit, such as air conditioners and refrigerators / refrigerators.

[0003] Figure 11 An example of such an electric valve is shown. As shown in the figure, a conventional electric valve 71 includes: a valve body 12 having a valve chamber 13 therein and having flow paths (inflow path 15 and outflow path 16) for allowing refrigerant to flow into and out of the valve chamber 13; a valve seat 14 forming an opening portion of the valve chamber 13 facing the inflow path 15; a valve core 17 that changes the amount (flow rate) of refrigerant passing through by moving forward and backward (up and down) relative to the valve seat 14; a valve core guide member 18 that closes the upper surface of the valve chamber 13 and supports the valve core 17 so that it can move up and down; a motor 41 that drives the valve core 17; a speed reduction mechanism 55 that reduces the rotation of the motor 41; a transmission mechanism 33 that converts the reduced rotational motion into linear motion and transmits it to the valve core 17; a connecting member 72 that connects the motor 41 to the valve body 12; and a shell (sealed container) 40 that, together with the connecting member 72, forms a sealed space on the upper surface of the valve body 12.

[0004] The connecting member 72 is a cylindrical member having a central hole extending vertically (in the direction of axis A). It is screwed into a connecting opening 19 formed on the upper surface of the valve body 12 so as to communicate with the valve chamber 13, thereby being secured to the valve body 12. A sealing member (O-ring) 73 is provided between the outer circumference of the connecting member 72 and the valve body 12 to prevent refrigerant leakage. This sealing member 73 is referred to as the "first sealing member" in this application, and the function of the first sealing member 73 is referred to as the "first sealing function."

[0005] The housing 40 is welded to the upper outer surface of the connecting member 72 via an annular base member 75. A screw bearing 31 is inserted into the upper center hole of the connecting member 72. The screw bearing 31 includes a screw feed mechanism 33 as the transmission mechanism.

[0006] On the other hand, the motor 41 is constituted by, for example, a stepping motor, and includes a stator 42 disposed outside the housing 40, a rotor 43 rotatably disposed inside the housing 40, and a resin molded cover 56. The resin molded cover 56 has a cylindrical leg 56a at its lower end that surrounds a connecting member 72. To prevent moisture from entering the motor 41, a sealing member (O-ring) 74 is provided between the inner circumference of the cylindrical leg 56a and the outer circumference of the connecting member 72. In this application, this sealing member 74 is referred to as the "second sealing member," and the function of the second sealing member 74 is referred to as the "second sealing function."

[0007] in addition, Figure 12 Another example of a conventional electric valve is shown. The electric valve 81 shown in this figure is different from the above-mentioned electric valve 71 ( Figure 11 ) Similarly, the refrigerant flow rate is adjusted by vertically moving the valve core 17a using a motor (stepping motor) 41. However, unlike the aforementioned electric valve 71, this valve core 17a includes a rod-shaped valve shaft 63 extending vertically along the central axis A of the electric valve 81 from the interior of the rotor 43 to the valve chamber 13. The valve core 17a is integrally provided at the lower end of the valve shaft 63. Furthermore, the rotor 43 is rotatably and vertically movable inside the housing 40. The valve shaft 63 and rotor 43 move vertically as a unit, thereby adjusting the valve opening.

[0008] In addition, in the electric valve 81, the valve body is composed of a main body 12a and a flow path block (not shown). The main body 12a has a valve chamber 13 inside and is screwed and fixed by a connecting component 72. The flow path block has an inlet and an outlet path inside and is screwed and fixed by the main body 12a. However, the connection structure between the motor 41 and the valve body (main body 12a), that is, the connecting component 72, the first sealing component 73 and the second sealing component 74 have the same structure as the above-mentioned electric valve 71.

[0009] In addition, there is the following Patent Document 1 as a document that discloses an electric valve.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-110409.

[0013] However, in the conventional electric valves 71 and 81 , there is still room for improvement in the connection portion between the valve body 12 and the electric motor 41 .

[0014] Specifically, the connecting member 72 that secures the motor 41 to the valve body 12 includes a threaded portion and is therefore formed from a readily machinable material (e.g., SUS303). Meanwhile, the connection to the housing 40 is achieved via a base member 75 formed from a highly weldable material (e.g., SUS304). The two components (connecting member 72 and base member 75) are brazed together to form a single unit. Consequently, the connection between the valve body 12 and the motor 41 requires a large number of components and steps, resulting in high manufacturing costs.

[0015] On the other hand, it is considered to integrate the connecting member 72 and the base member 75 as a stamped part with good mass production and cost advantages, and then cut the threaded portion. However, simply replacing the conventional connecting member 72 with a stamped part may cause the following problems.

[0016] Stamped parts generally have thin walls and insufficient strength, or may deform radially due to pressure fluctuations when the valve is used. On the other hand, the outer peripheral surface of the connecting component 72 is provided with sealing components (a first sealing component 73 and a second sealing component 74 composed of O-rings) between the resin molded cover 56 (foot 56a) and the valve body 12 (the inner peripheral surface of the connecting opening 19). Therefore, if the connecting component is deformed in the radial direction, the compression rate of the sealing components 73 and 74 (the pressing strength of the sealing components 73 and 74 relative to the outer peripheral surface of the connecting component, the inner peripheral surface of the resin molded cover 56, and the inner peripheral surface of the connecting opening 19) may change, thereby causing refrigerant to leak from the valve chamber 13, or moisture or outside air to penetrate into the motor 41 and the valve chamber 13.

[0017] Furthermore, the above-mentioned problems cannot be solved by the invention described in Patent Document 1. Summary of the Invention

[0018] Therefore, an object of the present invention is to solve the above-mentioned problem and to make the connecting member by a punched part, thereby improving the productivity of the electric valve and reducing the manufacturing cost.

[0019] In order to solve the above-mentioned technical problems and achieve the purpose, the electric valve involved in the present invention comprises: a valve body, which has a valve chamber connected to an inlet path and an outlet path inside; a valve core, which moves forward and backward relative to a valve seat formed in the valve chamber; an electric motor, which has a rotor and a stator for driving the valve core; a shell, which accommodates the rotor on the inside and arranges the stator on the outside; a connecting component, which connects the shell and the valve body; and a sealing component, which extends in a manner to surround the connecting component and abuts against the outer peripheral surface of the connecting component and the inner peripheral surface of the outer shell of the stator in a pressed state, wherein the connecting component is formed by stamping, and the connecting component has a cylindrical portion, and a rigid component is embedded in the cylindrical portion, and in the axial direction of the electric valve, the cylindrical portion, the rigid component, and the sealing component are arranged in a manner that overlaps with each other.

[0020] In the electric valve of the present invention, the connecting member connecting the housing (sealed container) to the valve body is formed by a stamping process. Therefore, in the present invention, a rigid member is inserted (e.g., press-fitted) into the cylindrical portion of the connecting member, and the cylindrical portion, rigid member, and sealing member are arranged to overlap with each other in the axial direction of the electric valve.

[0021] Here, a "rigid component" refers to a component that is difficult to deform radially even when external force is applied. If such a rigid component is embedded in the connecting component, the strength of the connecting component (cylindrical portion) as a stamped component can be increased, and radial deformation can be prevented or suppressed. Therefore, according to the present invention, the radial compression rate of the sealing component provided to surround the cylindrical portion can be stabilized (maintained constant), preventing moisture from infiltrating the motor from the outside.

[0022] The phrase "the cylindrical portion, the rigid member, and the sealing member are arranged to overlap with each other in the axial direction of the electric valve" refers to the sealing member being arranged on the outer circumferential surface of the portion of the cylindrical portion into which the rigid member is inserted. Alternatively, the phrase "there is a portion where the cylindrical portion, the rigid member, and the sealing member overlap when viewed in a direction perpendicular to the axial direction of the electric valve (also in the radial direction of the cylindrical portion)" may be used.

[0023] The rigid component is further described. This component is a typical component with a large wall thickness produced by cutting (a cutting component). However, since the purpose of the present invention can be achieved as long as the rigidity is sufficient to suppress the deformation of the cylindrical portion, it is not necessarily limited to a cutting component, and it can also be a component produced by other methods. In addition, the type (purpose function) of the rigid component is not limited. In the embodiment described later, the threaded bearing constituting the transmission mechanism (threaded feed mechanism) is inserted into the connecting component as the rigid component of the present invention, but as long as the rigidity is sufficient to suppress the deformation of the cylindrical portion, the purpose of the present invention can also be achieved. Therefore, it can also be a component or a part thereof with other purposes and functions provided on the electric valve.

[0024] In the present invention, the following aspects (1) to (5) can be preferably adopted.

[0025] (1) The valve body has a connection opening for securing the connection member, and the cylindrical portion has an insert portion disposed within the connection opening; a protrusion portion protruding from the connection opening toward the motor; and a flange portion extending outward from the protrusion portion so as to face the valve body with a gap therebetween. The sealing member is further disposed between the valve body and the flange portion and abuts against the valve body and the flange portion in a pressed state. Furthermore, the connection opening is formed on a surface of the valve body on the side where the motor is disposed (the motor mounting surface).

[0026] In the present invention described above, the sealing member achieves the function of preventing moisture from entering the motor by abutting the outer peripheral surface of the connecting member and the inner peripheral surface of the motor housing in a pressed state (equivalent to the second sealing function of the conventional electric valve described above). However, in addition to this, according to the above-mentioned method (1), by sealing the flange portion opposite to the valve body and the valve body, it is also possible to achieve the function of preventing refrigerant from leaking out of the valve chamber through the inner peripheral surface of the connecting opening and the interlocking portion, or preventing external air or moisture from entering the valve chamber from the outside (equivalent to the first sealing function of the conventional electric valve described above). Therefore, according to this method (1), it is possible to provide a single sealing member (using a single sealing member to serve as both the first sealing member and the second sealing member in the conventional electric valve), thereby reducing the number of parts and the manufacturing workload compared to the conventional electric valve.

[0027] (2) In the above-mentioned embodiment (1), the shell is fixed (for example, by welding) to the flange portion. By fixing the shell to the flange portion in this way, the base member used in the past can be omitted, and the number of parts and the manufacturing workload can be further reduced compared to the conventional electric valve.

[0028] (3) In the above-mentioned method (1), the connection opening has an internal thread on the inner peripheral surface of the connection opening, and the insertion portion has an external thread on the outer peripheral surface that is screwed into the internal thread and is fixed to the valve body by being screwed into the connection opening. The connection opening has a stop portion that can abut against the insertion portion that is screwed into the connection opening and moves in the depth direction of the connection opening to stop the insertion portion. When the insertion portion abuts against the stop portion, the sealing component abuts against the valve body and the flange portion in a pressed state.

[0029] According to the embodiment (3), the compression rate of the sealing member with respect to the axial direction of the electric valve (the pressing strength against the flange portion and the valve body surface facing the flange portion) can be accurately set.

[0030] (4) In the present invention or any of the above aspects (1) to (3), the sealing member includes a convex portion on its outer peripheral surface that contacts the inner peripheral surface of the housing. This is to enhance the sealing effect (second sealing function) of the sealing member.

[0031] (5) In the present invention or any one of the above-mentioned embodiments (1) to (3), the connecting component includes a valve core guide portion that is integrally formed with the cylindrical portion by stamping and supports the valve core so that it can move forward and backward relative to the valve seat.

[0032] According to this embodiment (5), the function of supporting the valve core can be added to the connecting component, thereby reducing the number of components and the manufacturing workload compared to an electric valve having a valve core guide component as another component. In addition, in the above-mentioned valve core guide portion, "supporting the valve core" does not mean directly supporting the valve core, but includes the concept of indirectly supporting the valve core via other components or parts (for example, via the valve shaft as in the third embodiment described later).

[0033] According to the present invention, the connecting member that connects the electric motor and the valve body can be formed as a press part, thereby improving the productivity of the electric valve and reducing the manufacturing cost.

[0034] Other objects, features and advantages of the present invention will become clear by the following description of the embodiments of the present invention based on the drawings. In addition, the present invention is not limited to the following embodiments, and it is obvious to those skilled in the art that various modifications can be made within the scope of the scope of the claims. In addition, in the various figures, the same symbols represent the same or equivalent parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a longitudinal sectional view showing the electric valve (valve closed state) according to the first embodiment of the present invention.

[0036] Figure 2It is a longitudinal sectional view showing the electric valve (in an open state) according to the first embodiment.

[0037] Figure 3 It is a longitudinal sectional view showing a state where the electric valve connecting member according to the first embodiment is formed by press working.

[0038] Figure 4 This is a longitudinal sectional view showing a state in which the connecting member of the electric valve according to the first embodiment is formed by press working and then completed by cutting working.

[0039] Figure 5 It is a longitudinal sectional view showing an electric valve (valve closed state) according to a second embodiment of the present invention.

[0040] Figure 6 It is a longitudinal sectional view showing a state in which a connecting member of the electric valve according to the second embodiment is formed by press working.

[0041] Figure 7 This is a longitudinal sectional view showing a state in which the connecting member of the electric valve according to the second embodiment is formed by press working and then completed by cutting working.

[0042] Figure 8 It is a longitudinal sectional view showing an electric valve (valve closed state) according to a third embodiment of the present invention.

[0043] Figure 9 It is a longitudinal sectional view showing a state in which a connecting member of the electric valve according to the third embodiment is formed by press working.

[0044] Figure 10 This is a longitudinal sectional view showing a state in which the connecting member of the electric valve according to the third embodiment is formed by press working and then completed by cutting working.

[0045] Figure 11 This is a longitudinal sectional view showing an example of a conventional electric valve (valve closed state).

[0046] Figure 12 It is a longitudinal sectional view showing another example (valve closed state) of a conventional electric valve. DETAILED DESCRIPTION

[0047] Reference Figures 1 to 10The following describes the electric valve according to the embodiments of the present invention. In addition, mutually orthogonal two-dimensional coordinates representing the vertical and horizontal directions are shown in the figures as appropriate. The following description is based on these directions. However, the electric valve according to the present invention and its embodiments can be used in various orientations. These directions are for convenience of explanation, and the various components of the present invention are not limited to these directions. Furthermore, when the terms "vertical" and "horizontal" are mentioned, the vertical direction corresponds to the vertical direction, and the direction orthogonal to the vertical direction is the horizontal direction, which includes the horizontal direction.

[0048] [First embodiment]

[0049] like Figures 1 to 4 As shown, the electric valve 11 involved in the first embodiment of the present invention includes: a valve body 12, which has a valve chamber 13 inside and has an inlet path 15 and an outlet path 16, the inlet path 15 allows the refrigerant to flow into the valve chamber 13, and the outlet path 16 allows the refrigerant to flow out of the valve chamber 13; a valve seat 14, which is formed at the opening of the inlet path 15 to the valve chamber 13; a valve core 17, which changes the amount (flow rate) of refrigerant passing through by moving forward and backward (up and down) relative to the valve seat 14; a valve core guide member 18, which closes the upper surface of the valve chamber 13 and adjusts the valve core 1 7 is supported so as to be movable up and down; a motor 41, which drives the valve core 17; a reduction mechanism (single planetary gear reduction mechanism) 55, which reduces the rotation of the motor 41; a transmission mechanism 33, which converts the reduced rotational motion into linear motion and transmits it to the valve core 17; a connecting component 21, which connects the motor 41 to the valve body 12; and a shell (sealed container) 40, which has a bottomless and covered cylindrical shape (the bottom surface is open and the top surface is closed), and together with the connecting component 21 forms a sealed space on the upper surface of the valve body 12.

[0050] The connecting member 21 connecting the motor 41 and the valve body 12 is formed by stamping the entire shape of the connecting member 21 and then subjected to necessary cutting. Figure 3 As shown in FIG. 1 , a bottomless and coverless cylindrical member 20 is formed by stamping, which includes a cylindrical portion 22 having a cylindrical shape and a flange portion (flange portion) 23 extending horizontally outward from the upper end of the cylindrical portion 22. Figure 4 As shown, the cylindrical component 20 is formed by cutting on the inner side of the upper end portion of the cylindrical component 20 to form an annular enlarged diameter portion 24 for pressing into the threaded bearing 31 (described later) as a rigid component mentioned in the present invention, and an external thread 25 is formed on the outer peripheral surface of the lower end portion of the cylindrical portion 22.

[0051] On the other hand, a connection opening 19 for receiving the connection member 21 (cylindrical portion 22) is formed on the upper surface (motor mounting surface) of the valve body 12 on which the electric motor 41 is mounted, and an internal thread 19a is formed on the inner circumferential surface of the connection opening 19, into which the external thread 25 is screwed. Furthermore, a platform 19b is formed on the connection opening 19 against which the connection member 21 (cylindrical portion 22) abuts. The connection member 21 is screwed into the connection opening 19 by threading the external thread 25 on the outer circumferential surface into the internal thread 19a on the inner circumferential surface of the connection opening 19. However, the connection member 21 is fixed to the valve body 12 by abutting the lower end of the cylindrical portion 22 against the platform 19b. Furthermore, in this fixed state, the entire cylindrical portion 22 is not submerged in the connection opening 19, but rather the upper portion of the cylindrical portion 22 protrudes upward from the connection opening 19.

[0052] The portion 22a of the cylindrical portion 22 that is disposed within (submerged in) the connection opening 19 is referred to as the "insertion portion," and the portion 22b that protrudes upward from the connection opening 19 is referred to as the "protrusion." Furthermore, by securing the connecting member 21 to the valve body 12 so as to form the protrusion 22b, a gap is formed between the flange portion 23 and the upper surface of the valve body 12, and a sealing member 30 (described later) is disposed in this gap.

[0053] The motor 41 is a stepping motor having a stator 42 disposed outside a housing 40, a rotor 43 rotatably disposed inside the housing 40, and a resin molded cover (housing) 56 covering the housing 40 and the stator 42. The resin molded cover 56 has a cylindrical leg 56a at its lower end that surrounds the protrusion 22b and the flange 23 of the connecting member 21 with a predetermined distance therebetween.

[0054] Furthermore, a sealing member 30 is provided. This sealing member 30 is located between the inner circumferential surface of the leg portion 56a and the outer circumferential surface of the protrusion 22b, and between the lower surface of the flange portion 23 and the upper surface of the valve body 12. This sealing member 30 is an elastic, annular resin member and includes an annular protrusion 30a that extends over the entire circumference of the sealing member 30, protruding outward from the outer circumferential surface of the sealing member 30. During installation, when the connecting member 21 is screwed into the connecting opening 19, the sealing member 30 is positioned on the outer circumferential surface of the cylindrical portion 22 so as to be sandwiched between the flange portion 23 and the upper surface of the valve body 12.

[0055] The height dimension (the dimension in the vertical direction) of the sealing member 30 is larger than the distance between the flange portion 23 and the upper surface of the valve body 12 when the connecting member 21 is fixed to the connecting opening 19 (when the lower end of the cylindrical portion 22 abuts the step 19b). When the lower end of the connecting member 21 (cylindrical portion 22) screwed into the connecting opening 19 abuts the step 19b and stops, the sealing member 30 is clamped between the flange portion 23 and the valve body 12 and crushed (compressed) at a predetermined (pre-designed) compression rate. This enables a seal between the flange portion 23 and the upper surface of the valve body 12, preventing refrigerant from leaking out of the valve chamber 13 or preventing outside air from entering the valve chamber 13. In other words, the above-mentioned first sealing function can be achieved.

[0056] Furthermore, similar to the height dimension described above, the thickness dimension (horizontal dimension) of the sealing member 30—that is, the distance between the inner circumferential surface of the sealing member 30, which contacts the outer circumferential surface of the cylindrical portion 22, and the top of the protrusion 30a—is greater than the distance between the inner circumferential surface of the foot portion 56a of the resin molded cover 56 and the outer circumferential surface of the cylindrical portion 22 (protrusion 22b). Therefore, when the sealing member 30 is installed within the resin molded cover 56, which contains the stator 42, and is covered by the housing 40, the protrusion 30a of the sealing member 30 is pressed against the inner circumferential surface of the foot portion 56a of the resin molded cover 56, while the inner circumferential surface of the sealing member 30 is pressed against the outer circumferential surface of the cylindrical portion 22 (protrusion 22b). This enables a seal between the cylindrical portion 22 (protrusion 22b) and the foot portion 56a of the resin molded cover 56, preventing moisture from entering the interior of the motor 41 (the resin molded cover). In other words, the aforementioned second sealing function is achieved.

[0057] As described above, according to this embodiment, one sealing member 30 can be used as both of the conventionally provided two sealing members (the first sealing member 73 and the second sealing member 74 ), thereby reducing the number of components and the workload during manufacturing.

[0058] Furthermore, while the sealing member 30 of this embodiment has both a first sealing function and a second sealing function, a sealing member having only a second sealing function (i.e., a member that seals between the protrusion 22b and the leg 56a) may be used in place of the sealing member 30. In this case, since a sealing member having a first sealing function is required in addition, for example, a sealing member (second sealing member) that seals between the outer peripheral surface of the connecting member 21 and the inner peripheral surface of the connecting opening 19 of the valve body 12 when the connecting member 21 is attached to the valve body 12 may be used (this also applies to the second and third embodiments described below).

[0059] The shell 40 is joined to the upper surface of the flange portion 23. In this embodiment, since the connecting member 21 has a base member 75 (see FIG. Figure 11 ) The flange portion 23 has the same annular shape, so the base component 75 is not required.

[0060] The stator 42 disposed on the outside of the housing 40 includes a yoke 44 and a coil 46 wound around a bobbin 45. On the other hand, the rotor 43 disposed on the inside of the housing 40 is composed of a cylindrical rotor component 43a made of a magnetic material (permanent magnet) and a sun gear component 48 made of a resin material, which are integrally connected.

[0061] The shaft 44 is inserted into the center portion of the sun gear member 48 , and the upper portion of the shaft 44 is supported by a support member 47 disposed inside the top portion of the housing 40 .

[0062] The sun gear 48a of the sun gear member 48 meshes with a plurality of planetary gears 49, which are rotatably supported by a shaft 52 of a planetary carrier 53 mounted on the bottom surface of the output gear 54. The upper portions of the planetary gears 49 mesh with an annular ring gear (internal fixed gear) 50 mounted on the upper portion of a cylindrical member 39 fixed to the upper portion of a threaded bearing 31 (described later). The lower portions of the planetary gears 49 mesh with the internal gear 51 of the annular output gear 54. The slightly different number of teeth on the ring gear 50 and the internal gear 51 of the output gear 54 reduce the rotational speed of the sun gear 48a at a large reduction ratio before transmitting it to the output gear 54. Furthermore, this gear mechanism (the sun gear 48a, the planetary gears 49, the ring gear 50, and the output gear 54) constitutes a reduction mechanism (single planetary gear reduction mechanism) 55 that reduces the rotational speed of the stepping motor 41.

[0063] A cylindrical threaded bearing 31 is press-fitted into the expanded diameter portion 24 above the connecting member 21, abutting against the lower end of the expanded diameter portion 24. (The threaded bearing 31 is inserted into the cylindrical portion 22 while the cylindrical portion 22 is pressed in the expanding direction by the threaded bearing 31.) This secures the connection member 21. The threaded bearing 31 is a thick cylindrical member. Pressing this rigid member into the connection member 21 improves the strength of the thinly-walled connecting member 21 and suppresses radial deformation.

[0064] Therefore, according to this embodiment, it is possible to prevent the connection member 21 from deforming radially due to pressure fluctuations during valve use, etc., which could cause changes in the compression rate of the sealing member 30 and reduce the sealing performance. Furthermore, since the housing 40 is joined to the connection member 21 (flange portion 23), the diameter of the flange portion 23 changes due to changes in the diameter of the cylindrical portion 22. This also prevents the inner diameter of the housing 40 from changing, which could cause the rotor 43 to rub against the inner circumferential surface of the housing 40 and thus hinder its rotation.

[0065] The output gear 54 is in slidable contact with the upper surface of the screw bearing 31. Furthermore, the upper portion of the stepped cylindrical output shaft 38 is press-fitted into the center of the bottom portion of the output gear 54, while the lower portion of the output shaft 38 is rotatably inserted into the insertion hole 31a formed in the center portion of the upper surface of the screw bearing 31. Furthermore, the lower end portion of the shaft 44 is relatively rotatably inserted into the upper portion of the output shaft 38.

[0066] An internal thread portion 31b is formed at the lower center portion of the threaded bearing 31, and an external thread portion 32b formed on the outer circumferential surface of the threaded drive member 32 is screwed into the internal thread portion 31b. The threaded bearing 31 (internal thread portion 31b) and the threaded drive member 32 (external thread portion 32b) together constitute a transmission mechanism (thread feed mechanism) 33 that converts rotational motion supplied from the stepping motor 41 via the speed reduction mechanism 55 into vertical linear motion and transmits the resulting linear motion to the valve element 17.

[0067] Here, the output gear 54 rotates without moving vertically at a predetermined position in the vertical direction. The flat-head screwdriver-shaped plate portion 32a provided at the upper end of the thread drive member 32 is inserted into the slit-shaped fitting groove 38a provided at the lower end of the output shaft 38 connected to the output gear 54, thereby transmitting the rotational motion of the output gear 54 to the thread drive member 32. As the plate portion 32a provided on the thread drive member 32 slides vertically within the fitting groove 38a of the output shaft 38, when the output gear 54 (rotor 43) rotates, the thread drive member 32 linearly moves in the vertical direction, even though the output gear 54 does not move vertically.

[0068] The linear motion of the screw drive member 32 is transmitted to the valve element 17 via a ball joint 35 and a spring support member 36. The ball joint 35 is composed of a ball 34a and a ball socket 34b. The valve element 17 comprises a valve element body 17a that contacts and separates from the valve seat 14, and a stepped cylindrical valve element support 17b that rises upward from the center of the upper surface of the valve element body 17a. The upper end of the valve element support 17b is inserted into a fitting hole (lower surface fitting hole) 36b formed in the center of the lower surface of the spring support member 36, connecting the spring support member 36 to the valve element 17 (valve element support 17b). The spring support member 36 also has a fitting hole (upper surface fitting hole) 36a formed in the center of the upper surface of the spring support member 36, into which the ball socket 34b is inserted.

[0069] Furthermore, the valve element guide member 18 is fixed to the bottom surface of the connecting opening 19 on the upper surface of the valve body, thereby sealing the upper surface of the valve chamber 13. The valve element guide member 18, fixed to the upper portion of the valve chamber 13, has a stepped through-hole formed at its center, through which the valve element support portion 17b is inserted, allowing for vertical sliding movement. A compression coil spring 37 is also provided between the upper portion of this through-hole and the spring support member 36. This compression coil spring 37 biases the valve element 17 upward, in the valve opening direction. Therefore, during valve opening, the biasing force of the coil spring 37 is applied to the valve element 17 in addition to the driving force of the motor 41, ensuring more reliable valve opening.

[0070] In addition, in this embodiment, the center axes of the valve core 17, valve seat 14, valve core guide component 18, connecting component 21, threaded bearing 31, threaded drive component 32, output shaft 38, shaft 44, and rotor 43 are consistent with the axis A of the electric valve 11 extending perpendicularly to the up and down directions.

[0071] Next, the operation of the electric valve 11 according to this embodiment will be described.

[0072] When from Figure 1 When current is supplied to the stator 42 (coil 46) in the closed valve state shown to rotate the rotor 43 in one direction, the rotation of the rotor 43 is converted into linear motion by the screw feed mechanism 33, and the screw drive member 32 is pulled upward. In conjunction with this, the spring support member 36, which is pressed against the lower surface of the screw drive member 32 via the ball joint 35 by the force of the compression coil spring 37, and the valve core support portion 17b connected to the spring support member 36 are pulled upward, so that the valve core body 17a leaves the valve seat 14, and the refrigerant flowing in from the inlet path 15 passes through the valve chamber 13 and flows out from the outflow path 16 (see Figure 2 ). In addition, the amount of refrigerant passing through (refrigerant flow rate) in the valve open state can be adjusted by the amount of rotation of the rotor 43.

[0073] On the other hand, when current is supplied to the stator 42 (coil 46) from the valve open state to rotate the rotor 43 in the direction opposite to the above-mentioned one direction, the rotation of the rotor 43 is converted into linear motion by the screw feed mechanism 33, and the screw drive component 32 moves downward. Accompanying this downward movement, the ball joint 35, the spring support component 36, and the valve core 17 move downward. When the valve core body 17a contacts the valve seat 14, the flow path between the inlet path 15 and the outlet path 16 is cut off, and the valve is closed (see Figure 1 ).

[0074] [Second embodiment]

[0075] Reference Figures 5 to 7A motor-operated valve according to a second embodiment of the present invention will be described. The same components as those of the motor-operated valve according to the first embodiment are denoted by the same reference numerals, and duplicate descriptions are omitted. The description will focus on the differences.

[0076] like Figures 5 to 7 As shown, the electric valve 61 according to the second embodiment of the present invention differs from the first embodiment in that the connecting member 21 and the valve body guide member 18 in the first embodiment are formed as an integrated member (a connecting member 21 a having a valve body guide portion 28 ).

[0077] Specifically, similarly to the first embodiment, the entire shape of the connecting member 21a is formed by press working and then subjected to necessary cutting work to be manufactured. Figure 6 As shown, the cylindrical component 20a formed by stamping has, in addition to the cylindrical portion 22 and flange portion 23 similar to those of the first embodiment, a reduced diameter portion 26 extending downward from the lower end of the cylindrical portion 22 and a valve core guide portion 28 extending downward from the lower end of the reduced diameter portion 26.

[0078] In addition, the diameter of the reduced diameter portion 26 is smaller than that of the cylindrical portion 22, so a step portion 27 is formed between the cylindrical portion 22 and the reduced diameter portion 26. This step portion 27, like the lower end of the cylindrical portion 22 in the first embodiment, abuts against the terrace 19b formed on the inner circumferential surface of the connecting opening 19 to achieve the function of setting the compression rate of the sealing member 30 in the vertical direction to an appropriate value. In addition, the step portion 27 is processed to make the lower surface abutting against the terrace 19b flat during the cutting process described below (see Figure 7 ). In addition, the valve core guide portion 28 and the valve core guide member 18 (see Figure 1 ) Similarly, the function of supporting the valve core 17 (valve core support portion 17b) so as to be able to move up and down is realized.

[0079] After the cylindrical member 20a is formed, as shown in FIG. Figure 7 As shown, an expanded diameter portion 24 is formed at the upper end of the cylindrical portion 22 by cutting, and an external thread 25 is formed on the outer circumferential surface of the lower end of the cylindrical portion 22. These expanded diameter portion 24 and external thread 25 have the same functions as those of the first embodiment. Furthermore, in this embodiment, a flat spring receiving surface 29 is formed at the upper end of the valve core guide 28 (the boundary between the reduced diameter portion 26 and the valve core guide 28) by cutting to accommodate the compression coil spring 37.

[0080] According to this embodiment, the valve body guide member 18 can be integrally formed with the connecting member 21a as the valve body guide portion 26 formed at the lower end of the connecting member 21a. Therefore, the number of parts and the workload during manufacturing can be further reduced compared to the first embodiment.

[0081] [Third embodiment]

[0082] Reference Figures 8 to 10 The following describes a motor-operated valve according to a third embodiment of the present invention. The same components as those of the motor-operated valves of the first and second embodiments are denoted by the same reference numerals, and duplicate descriptions are omitted. The following description focuses on the differences.

[0083] like Figures 8 to 10 As shown, the electric valve 62 of this embodiment is similar to the first embodiment, and adjusts the flow rate of the refrigerant by moving the valve core 17a up and down by the electric motor (stepping motor) 41, but has the following structure: a rod-shaped valve shaft 63 extending in the up and down direction along the axis A from the inside of the rotor 43 to the valve chamber 13 and having the valve core 17a at the lower end, and the valve core 17a (valve shaft 63) is connected to the rotor 43 without passing through a reduction mechanism (single planetary gear reduction mechanism).

[0084] More specifically, the valve shaft 63 has a cylindrical trunk 63a and an upper, smaller-diameter portion 63b, which is coaxially continuous with the trunk 63a at its upper end. Furthermore, the valve core 17a is integrally mounted on the lower end of the valve shaft 63 (trunk 63a). The rotor 43 is rotatably and vertically movable within the housing 40. The valve is opened and closed by the integrated vertical movement of the valve shaft 63, which has the valve core 17a at its lower end, and the rotor 43.

[0085] A valve shaft holder 64 is provided inside the rotor 43. The valve shaft holder 64 has a cylindrical shape with a closed upper end. A support ring 65 is fixed to the upper end of the valve shaft holder 64 by riveting. Furthermore, the rotor 43 and the valve shaft holder 64 are integrally connected via the support ring 65. An internal thread 64a is formed on the inner circumferential surface of the valve shaft holder 64. This internal thread 64a screws into the external thread 68c of the guide bushing 68, described later, to form a transmission mechanism (thread feed mechanism) that converts the rotation of the motor 41 into linear motion and transmits it to the valve shaft 63.

[0086] The upper, smaller-diameter portion 63b of the valve shaft 63 passes through the valve shaft holder 64. A push rod nut 66, serving as a retaining member, is attached to the upper end of the upper, smaller-diameter portion 63b. The valve shaft 63 is biased downward by a compression coil spring 67, which is interposed between the valve shaft holder 64 and a land portion provided between the body 63a and the upper, smaller-diameter portion 63b of the valve shaft 63. Therefore, the vertical movement of the valve shaft 63 relative to the valve shaft holder 64 is restricted by the push rod nut 66 and compression coil spring 67, allowing the valve shaft 63 to move vertically along with the valve shaft holder 64.

[0087] The connecting member 21b is manufactured by forming the entire shape by press working and then performing necessary cutting work, similarly to the first and second embodiments. Figure 9 As shown, the cylindrical component 20b formed by stamping has the same cylindrical portion 22 and flange portion 23 as the first embodiment, and has a valve core guide portion 28 as the second embodiment. In addition, the valve core guide portion 28 is formed at the lower portion of the cylindrical portion 22, and supports the valve shaft 63 so that it can move up and down. In addition, the diameter of the valve core guide portion 28 is smaller than the cylindrical portion 22, and a step portion 27 is formed between the cylindrical portion 22 and the valve core guide portion 28, which enables the step portion 27 to abut against the platform 19b of the connecting opening 19. In addition, according to this embodiment, since the valve core guide portion 28 is integrally provided with the connecting component 21b, the number of components and the workload during manufacturing can be reduced compared to the first embodiment.

[0088] After the cylindrical member 20b is formed, as shown in FIG. Figure 10 As shown, an expanded diameter portion 24 is formed inside the upper end of the cylindrical portion 22 by cutting, and an external thread 25 is formed on the outer peripheral surface of the lower end of the cylindrical portion 22. These expanded diameter portion 24 and external thread 25 have the same functions as those of the first and second embodiments.

[0089] A guide bushing 68, serving as a rigid member according to the present invention, is press-fitted and secured to the expanded diameter portion 24 of the connecting member 21b. This guide bushing 68 comprises a large-diameter cylindrical portion 68a having a large outer diameter, and a small-diameter cylindrical portion 68b having a small outer diameter, formed coaxially and continuously with the large-diameter cylindrical portion 68a above the large-diameter cylindrical portion 68a. The outer circumferential surface of the small-diameter cylindrical portion 68b is formed with an external threaded portion 68c, which is threadedly engaged with the internal threaded portion 64a of the valve shaft retainer 64.

[0090] The valve shaft holder 64 is provided with an upper stopper 69, while the large-diameter cylindrical portion 68a of the guide bushing 68 is provided with a lower stopper 70. These stoppers 69 and 70 determine the lower limit position of the valve shaft holder 64. When the valve shaft holder 64 rotates and descends to the lower limit position, the upper stopper 69 abuts against the lower stopper 70, thereby restricting further rotation of the valve shaft holder 64.

[0091] In this embodiment, the valve body 12 is composed of a main body 12a, which has a valve chamber 13 internally and to which a connecting member 21b is screwed and fixed, and a flow block (not shown). The flow block, which has an inlet and outlet passages internally and to which the main body 12a is screwed, is also fixed. Furthermore, the inlet hole 15a and outlet hole 16a, provided in the main body 12a so as to communicate with the valve chamber 13, communicate with the inlet and outlet passages of the flow block, respectively, when the main body 12a is screwed into the flow block. The sealing member 30 has the same structure and function as in the first and second embodiments.

[0092] Next, the operation of the electric valve 62 according to this embodiment will be described.

[0093] In from Figure 8 In the valve closed state shown, when current is supplied to the stator 42 (coil 46) to rotate the rotor 43 in one direction, the valve shaft holder 64 coupled to the rotor 43 rotates along with the rotor 43. An internal threaded portion 64a is formed on the inner circumferential surface of the valve shaft holder 64. This internal threaded portion 64a screws into an external threaded portion 68c formed on the outer circumferential surface of the small-diameter cylindrical portion 68b of the guide bushing 68. Therefore, through the interaction between these external threaded portions 68c and the internal threaded portion 64a, the rotation of the rotor 43 (valve shaft holder 64) is converted into linear motion in the vertical direction, thereby causing the valve shaft holder 64 to move upward. The rotor 43 coupled to the valve shaft holder 64 and the valve shaft 63, whose relative movement with the valve shaft holder 64 is restricted, also move upward along with the valve shaft holder 64. As the valve shaft 63 moves upward, the valve core 17a provided at the lower end of the valve shaft 63 moves away from the valve seat 14, and the refrigerant flowing in from the inlet path passes through the valve chamber 13 and flows out from the outlet path. In addition, the refrigerant flow rate can be adjusted by the rotation amount of the rotor 43.

[0094] On the other hand, when current is supplied to the stator 42 (coil 46) from the valve open state to rotate the rotor 43 in the direction opposite to the above-mentioned one direction, the rotation of the rotor 43 (valve shaft holder 64) is converted into linear motion in the vertical direction through the interaction between the internal thread portion 64a and the external thread portion 68c, and the valve shaft holder 64, the rotor 43, and the valve shaft 63 move downward together. As a result, the valve core 17a descends toward the valve seat 14, and when the valve core 17a contacts the valve seat 14, it becomes Figure 8 The valve is shown in the closed state.

[0095] Explanation of symbols

[0096] Axis A (center axis), 11, 61, 62, 71, 81 electric valve, 12 valve body, 12a main body of the valve body, 13 valve chamber, 14 valve seat, 15 inflow path, 15a inflow hole, 16 outflow path, 16a outflow hole, 17, 17a valve core, 17b valve core support part, 18 valve core guide part, 19 connecting opening, 19a internal thread, 19b platform, 20, 20a, 20b cylindrical part, 21, 21a, 21b, 72 connecting part, 22 cylinder shaped portion, 22a insert portion, 22b protruding portion, 23 flange portion (flange portion), 24 expanded diameter portion, 25 external thread, 26 reduced diameter portion, 27 stepped portion, 28 valve core guide portion, 29 spring support surface, 30 sealing component, 30a convex portion, 31 threaded bearing, 31a inserting hole, 31b internal thread portion, 32 thread drive component, 32a plate-shaped portion, 32b external thread portion, 33 transmission mechanism (thread feed mechanism), 34a ball, 34b ball socket, 35 ball joint, 36 spring Spring support component, 37, 67 compression coil spring, 38 output shaft, 38a fitting groove, 39 cylindrical component, 40 housing (sealed container), 41 motor (stepping motor), 42 stator, 43 rotor, 43a rotor component, 44 yoke, 45 coil frame, 46 coil, 47 support component, 48 sun gear component, 48a sun gear, 49 planetary gear, 50 ring gear (internal gear fixed gear), 51 internal gear, 52 shaft, 53 planetary gear carrier, 54 output gear, 55 reduction mechanism (single planetary gear reduction mechanism), 56 resin molded cover (stator housing), 56a cylindrical foot, 63 valve shaft, 63a trunk, 63b upper small diameter portion, 64 valve shaft retainer, 64a internal thread portion, 65 support ring, 66 push rod nut, 68 guide bushing, 68a large diameter cylindrical portion, 68b small diameter cylindrical portion, 68c external thread portion, 69 upper stop body, 70 lower stop body, 73 first sealing component, 74 second sealing component, 75 base component.

Claims

1. An electric valve comprising: a valve body having a valve chamber therein communicating with the inflow path and the outflow path; a valve core that moves forward and backward relative to a valve seat formed in the valve chamber; an electric motor having a rotor and a stator for driving the valve core; a housing accommodating the rotor on an inner side and arranging the stator on an outer side; a connecting member connecting the housing and the valve body; as well as A sealing member extending so as to surround the connecting member and abutting against the outer peripheral surface of the connecting member and the inner peripheral surface of the stator housing in a pressed state, characterized in that: The connecting component is formed by stamping. The connecting member has a cylindrical portion, A rigid component is inserted into the cylindrical portion. The cylindrical portion, the rigid member, and the sealing member are arranged so as to overlap with each other in the axial direction of the electric valve.

2. The electric valve according to claim 1, characterized in that The valve body has a connection opening for fixing the connection component. The cylindrical portion has: an insertion portion, the insertion portion being disposed in the connecting opening; a protrusion that protrudes from the connection opening toward the motor side; and a flange portion extending outward from the protruding portion so as to face the valve body with a gap therebetween; The sealing member is further arranged between the valve body and the flange portion, and is in contact with the valve body and the flange portion in a pressed state.

3. The electric valve according to claim 2, characterized in that The shell is fixed to the flange portion.

4. The electric valve according to claim 2, characterized in that: The connecting opening has an internal thread on its inner circumferential surface, The insert portion has an external thread on its outer peripheral surface that is threadedly engaged with the internal thread, and is fixed to the valve body by being screwed into the connection opening. The connection opening has a stopper portion capable of abutting against the insertion portion that is screwed into the connection opening and advances in a depth direction of the connection opening to stop the insertion portion. When the insertion portion abuts against the stopper, the sealing member abuts against the valve body and the flange portion in a pressed state.

5. The electric valve according to any one of claims 1 to 4, characterized in that: The sealing member includes a convex portion on an outer peripheral surface of the sealing member that contacts the inner peripheral surface of the housing.

6. The electric valve according to any one of claims 1 to 4, characterized in that: The connecting member includes a valve body guide portion that is integrally formed with the cylindrical portion by press working and supports the valve body so as to be movable forward and backward relative to the valve seat.

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