Motor-operated valve

Abstract

Using press parts for the connecting members improves productivity and reduces manufacturing costs. [Solution] The valve comprises a valve body (12) having an inlet passage (15), an outlet passage (16) and a valve chamber (13), a valve element (17) that moves toward and away from a valve seat (14), an electric motor (41) having a rotor (43) and a stator (42) that drive the valve element, a can (40) that houses the rotor inside and has the stator on the outside, a connecting member (21) that connects the can and the valve body, and a sealing member (30) that extends to surround the connecting member and is pressed against the outer surface of the connecting member and the inner surface of the housing (56) of the electric motor, the connecting member being formed by press working and having a cylindrical portion (22) into which a rigid part (31) is inserted, the valve body having a connection opening (19) to which the connecting member is fixed, the cylindrical portion having an insertion portion (22a) that is positioned within the connection opening, a protruding portion (22b) that protrudes from the connection opening toward the electric motor, and a flange portion (23) that extends outward from the protruding portion so as to face the valve body at a distance, and the sealing member is disposed between the valve body and the flange.

Description

[Technical Field]

[0001] The present invention relates to an electrically operated valve, and more particularly to the structure of a connection portion that connects a valve body and an electric motor. [Background technology]

[0002] Electric valves, which use an electric motor such as a stepping motor to control the valve opening, have traditionally been used in refrigeration cycle equipment equipped with a refrigerant circuit, such as air conditioners and refrigerators / freezers.

[0003] An example of such a motor-operated valve is shown in Figure 11. As shown in this figure, a conventional motor-operated valve 71 includes a valve body 12 having a valve chamber 13 therein and flow paths (inflow path 15 and outflow path 16) for allowing refrigerant to flow in and out of the valve chamber 13, a valve seat 14 formed at the opening of the inflow path 15 to the valve chamber 13, a valve element 17 that moves toward and away from the valve seat 14 (up and down) to change the amount of refrigerant passing through (flow rate), a valve element guide member 18 that is provided to close the upper surface of the valve chamber 13 and supports the valve element 17 so that it can move up and down, an electric motor 41 that drives the valve element 17, a speed reduction mechanism 55 that slows down the rotation of the electric motor 41, a transmission mechanism 33 that converts the slowed-down rotational motion into linear motion and transmits it to the valve element 17, a connecting member 72 that connects the electric motor 41 to the valve body 12, and a can (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 that penetrates in the vertical direction (direction of axis A), and is fixed to the valve body 12 by being screwed into a connecting opening 19 drilled in the upper surface of the valve body 12 so as to communicate with the valve chamber 13. A seal member (O-ring) 73 that prevents leakage of the refrigerant is provided between the outer peripheral surface of the connecting member 72 and the valve body 12. In this application, the seal member 73 is referred to as the "first seal member," and the function of the first seal member 73 is referred to as the "first sealing function."

[0005] The can 40 is joined by welding to the outer peripheral surface of the upper part of the connecting member 72 via a ring-shaped base member 75. Furthermore, a screw bearing 31 is inserted into the upper part of the central hole of the connecting member 72, and a feed screw mechanism 33 is provided inside the screw bearing 31 as the transmission mechanism.

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

[0007] 12 shows another example of a conventional motor-operated valve. Similar to the motor-operated valve 71 (FIG. 11), the motor-operated valve 81 shown in this figure adjusts the flow rate of refrigerant by moving the valve element 17a up and down using an electric motor (stepping motor) 41. However, unlike the motor-operated valve 71, the motor-operated valve 81 has a rod-shaped valve stem 63 that extends vertically from the inside of the rotor 43 to the valve chamber 13 along the central axis A of the motor-operated valve 81, and the valve element 17a is integrally formed at the lower end of the valve stem 63. The rotor 43 is rotatably mounted inside the can 40 and vertically movable, and the valve opening is adjusted by the vertical movement of the valve stem 63 and rotor 43 together.

[0008] In addition, in this electric valve 81, the valve body consists of a main body portion 12a which has a valve chamber 13 inside and into which a connecting member 72 is screwed and fixed, and a flow path block (not shown) which has an inlet and outlet passages inside and into which the main body portion 12a is screwed and fixed, but the connection structure between the electric motor 41 and the valve body (main body portion 12a), i.e., the connecting member 72, first sealing member 73 and second sealing member 74, have the same structure as the electric valve 71.

[0009] Furthermore, the following Patent Document 1 is a document that discloses a motor-operated valve. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent Publication No. 2021-110409 Summary of the Invention [Problem to be solved by the invention]

[0011] However, in the conventional motor-operated valves 71 and 81, there is room for improvement in the connection between the valve body 12 and the motor 41.

[0012] Specifically, the connecting member 72 that fixes the electric motor 41 to the valve body 12 is made of a material that is easy to cut (e.g., SUS303) because it has a complex shape including a threaded portion. On the other hand, a base member 75 made of a material with excellent weldability (e.g., SUS304) is used to join it to the can 40, and the two members (connecting member 72 and base member 75) are integrated by brazing. For this reason, the connecting portion between the valve body 12 and the electric motor 41 requires a large number of parts and processes, which tends to increase manufacturing costs.

[0013] On the other hand, it is conceivable to integrate the connecting member 72 and the base member 75 as a press part, which is easy to mass-produce and advantageous in terms of cost, and then machine the threaded portion. However, simply replacing the conventional connecting member 72 with a press part may cause the following problems.

[0014] Pressed parts generally have thin walls, which may result in insufficient strength or radial deformation due to pressure fluctuations during valve use. On the other hand, the outer peripheral surface of the connecting member 72 is provided with seal members (a first seal member 73 and a second seal member 74, each consisting of an O-ring) between the connecting member 72 and the resin molded cover 56 (leg portion 56 a) or the valve body 12 (the inner peripheral surface of the connection opening 19). Therefore, if the connecting member deforms radially, the compression ratio of the seal members 73 and 74 (the pressing strength of the seal members 73 and 74 against the outer peripheral surface of the connecting member, the inner peripheral surface of the resin molded cover 56, and the inner peripheral surface of the connection opening 19) may change, potentially causing refrigerant leakage from the valve chamber 13 or the intrusion of moisture or outside air into the motor 41 or the valve chamber 13.

[0015] The above problems cannot be solved by the invention described in Patent Document 1.

[0016] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems, to enable the connecting member to be made of a pressed part, to improve the productivity of motor-operated valves, and to reduce manufacturing costs. [Means for solving the problem]

[0017] In order to solve the above problems and achieve the object, the motor-operated valve of the present invention comprises a valve body having an internal valve chamber communicating with an inlet passage and an outlet passage, a valve element that moves toward and away from a valve seat formed in the valve chamber, an electric motor having a rotor and a stator that drive the valve element, a can that houses the rotor inside and has the stator on the outside, a connecting member that connects the can and the valve body, and a sealing member that extends to surround the connecting member and is pressed against the outer surface of the connecting member and the inner surface of the housing of the stator, wherein the connecting member is formed by press working and has a cylindrical portion into which a rigid part is inserted, the valve body has a connection opening to which the connecting member is fixed, the cylindrical portion has an insertion portion that is positioned within the connection opening, a protruding portion that protrudes from the connection opening toward the electric motor, and a flange portion that extends outward from the protruding portion so as to face the valve body at a distance, and the sealing member is further positioned between the valve body and the flange. The connection opening is formed on the surface of the valve body on the side where the electric motor is installed (electric motor installation surface).

[0018] In the motor-operated valve of the present invention, the connecting member that connects the can (sealed container) and the valve body is made of a pressed part formed by press working. For this purpose, the present invention has a structure in which a rigid part is inserted (for example, press-fitted) into the cylindrical part of the connecting member.

[0019] Here, "rigid parts" refer to parts that are resistant to radial deformation even when subjected to external forces. By fitting such rigid parts into the connecting member, it is possible to increase the strength of the connecting member (cylindrical portion), which is a pressed part, and prevent or suppress radial deformation. Therefore, according to the present invention, it is possible to stabilize (keep constant) the radial compression rate of the sealing member provided to surround the cylindrical portion, thereby preventing moisture from entering the electric motor from the outside.

[0020] To further describe the rigid part, the part is typically a thick part (machined part) made by cutting. However, since the object of the present invention can be achieved as long as it has the rigidity to suppress deformation of the cylindrical part, it is not necessarily limited to a machined part, and parts made by other methods can also be used. Furthermore, the type (use function) of the rigid part is not important. In the embodiment described later, a screw bearing constituting a transmission mechanism (feed screw mechanism) is inserted into a connecting member as the rigid part referred to in the present invention, but since the object of the present invention can be achieved in the same way as long as it has the rigidity to suppress deformation of the cylindrical part, it may also be a part or part of a part that has another use function and is provided in the motor-operated valve.

[0021] In the present invention, the following embodiments (1) to (5) can be preferably adopted.

[0022] (1) The seal member is further disposed between the valve body and the flange and is in pressing contact with the valve body and the flange.

[0023] In the present invention described above, the seal member presses against the outer circumferential surface of the connecting member and the inner circumferential surface of the housing of the electric motor to prevent moisture from entering the electric motor (corresponding to the second sealing function of the conventional motor-operated valve). In addition, according to the above aspect (1), by sealing the gap between the flange portion facing the valve body and the valve body, it can also prevent refrigerant from leaking from the valve chamber through the gap between the inner circumferential surface of the connection opening and the fitting portion, or preventing outside air or moisture from entering the valve chamber from the outside (corresponding to the first sealing function of the conventional motor-operated valve). Therefore, according to the aspect (1), it is possible to use a single seal member (one seal member can serve as both the first seal member and the second seal member in the conventional motor-operated valve), which makes it possible to reduce the number of parts and manufacturing steps compared to the conventional motor-operated valve.

[0024] (2) In the above-mentioned aspect (1), the can is fixed to the flange (for example, by welding). By fixing the can to the flange in this way, the base member that was conventionally used can be omitted, and the number of parts and manufacturing steps can be further reduced compared to conventional motor-operated valves.

[0025] (3) In the above aspect (1), the connection opening has a female thread on its inner peripheral surface, and the insertion portion has a male thread on its outer peripheral surface that screws into the female thread and is fixed to the valve body by being screwed into the connection opening, and the connection opening has a stopper portion that can abut against and stop the insertion portion that is screwed into the connection opening and proceeds in the depth direction of the connection opening, so that when the insertion portion abuts against the stopper portion, the sealing member abuts against the valve body and the flange portion in a pressed state.

[0026] According to the aspect (3), it is possible to accurately set the compressibility of the seal member in the axial direction of the motor-operated valve (pressure strength against the flange and the valve body surface facing the flange).

[0027] (4) In the present invention or any of the above aspects (1) to (3), the seal member has a protrusion on its outer circumferential surface that abuts against the inner circumferential surface of the stator housing, in order to enhance the sealing effect (second sealing function) of the seal member.

[0028] (5) In the present invention or any of the aspects (1) to (3) above, the connecting member has a valve body guide portion that is molded integrally with the cylindrical portion by press working and supports the valve body so that it can move toward and away from the valve seat.

[0029] According to this aspect (5), the function of supporting the valve disc can be added to the connecting member, which makes it possible to reduce the number of parts and manufacturing man-hours compared to motor-operated valves that have a valve disc guide member as a separate part. Note that with regard to the valve disc guide portion, "supporting the valve disc" does not only mean directly supporting the valve disc, but also includes indirectly supporting the valve disc via other members or parts (for example, via the valve stem as in the third embodiment described below). [Effects of the Invention]

[0030] According to the present invention, the connecting member that connects the electric motor to the valve body can be made of a pressed part, thereby improving the productivity of the motor-operated valve and reducing the manufacturing cost.

[0031] Other objects, features, and advantages of the present invention will become apparent from the following description of the preferred embodiments of the present invention, which is given with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention is not limited to the following embodiments, and that various modifications can be made within the scope of the claims. In addition, the same reference numerals in the various drawings indicate the same or equivalent parts. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a motor-operated valve (in a closed state) according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a vertical cross-sectional view showing the motor-operated valve (open state) according to the first embodiment. [Figure 3] FIG. 3 is a vertical cross-sectional view showing a state in which the connecting member of the motor-operated valve according to the first embodiment has been formed by press working. [Figure 4] FIG. 4 is a vertical cross-sectional view showing a state in which the connecting member of the motor-operated valve according to the first embodiment is formed by press working and then completed by cutting working. [Figure 5] FIG. 5 is a vertical cross-sectional view showing a motor-operated valve (in a closed state) according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a vertical cross-sectional view showing a state in which the connecting member of the motor-operated valve according to the second embodiment has been formed by press working. [Figure 7] FIG. 7 is a vertical cross-sectional view showing a state in which the connecting member of the motor-operated valve according to the second embodiment is formed by press working and then completed by cutting working. [Figure 8] FIG. 8 is a vertical cross-sectional view showing a motor-operated valve (in a closed state) according to a third embodiment of the present invention. [Figure 9] FIG. 9 is a vertical cross-sectional view showing a state in which the connecting member of the motor-operated valve according to the third embodiment has been formed by press working. [Figure 10] FIG. 10 is a vertical cross-sectional view showing a state in which the connecting member of the motor-operated valve according to the third embodiment is formed by press working and then completed by cutting work. [Figure 11] FIG. 11 is a vertical cross-sectional view showing an example of a conventional motor-operated valve (in a closed state). [Figure 12] FIG. 12 is a vertical cross-sectional view showing another example of a conventional motor-operated valve (in a closed state). DETAILED DESCRIPTION OF THE INVENTION

[0033] The motor-operated valve according to an embodiment of the present invention will be described with reference to Figures 1 to 10. Note that in each figure, mutually orthogonal two-dimensional coordinates representing the up-down and left-right directions are appropriately displayed, and the following description will be based on these directions; however, the motor-operated valve according to the present invention and each embodiment can be used in various orientations, and the directions are used for the sake of convenience in the description, and the configuration of each part of the present invention is in no way limited by these directions. Furthermore, although the terms "vertical" and "horizontal" are used, the vertical direction coincides with the up-down direction, and the direction perpendicular to the vertical direction is the horizontal direction, which includes the left-right direction.

[0034] [First embodiment] As shown in FIGS. 1 to 4, a motor-operated valve 11 according to a first embodiment of the present invention comprises a valve body 12 having a valve chamber 13 therein and an inflow passage 15 for allowing a refrigerant to flow into the valve chamber 13 and an outflow passage 16 for allowing the refrigerant to flow out of the valve chamber 13, a valve seat 14 formed at the opening of the inflow passage 15 to the valve chamber 13, a valve element 17 that moves back and forth (up and down) relative to the valve seat 14 to change the amount of refrigerant passing through (flow rate), and a support member provided to close the upper surface of the valve chamber 13 and capable of moving the valve element 17 up and down. The valve body 12 includes a valve body guide member 18 supporting the valve body 17, an electric motor 41 that drives the valve body 17, a speed reduction mechanism (paradox planetary gear speed reduction mechanism) 55 that reduces the rotation speed of the electric motor 41, a transmission mechanism 33 that converts the reduced rotational motion into linear motion and transmits it to the valve body 17, a connecting member 21 that connects the electric motor 41 and the valve body 12, and a can (sealed container) 40 that has a cylindrical shape with an open bottom and a closed top (the bottom is open and the top is closed) and that, together with the connecting member 21, forms a sealed space on the upper surface of the valve body 12.

[0035] The connecting member 21 that connects the electric motor 41 and the valve body 12 is produced by pressing to form the overall shape of the member 21, followed by the necessary cutting process. Specifically, as shown in Fig. 3, a bottomless and lidless cylindrical member 20 is formed by pressing, which includes a cylindrical portion 22 having a cylindrical shape and a flange portion (brim portion) 23 that extends horizontally outward from the upper end of the cylindrical portion 22. Thereafter, as shown in Fig. 4, a ring-shaped expanded diameter portion 24 into which a screw bearing 31 (described later), which is a rigid part referred to in the present invention, is press-fitted is formed inside the upper end of the cylindrical member 20 by cutting, and a male thread 25 is formed on the outer peripheral surface of the lower end of the cylindrical portion 22.

[0036] Meanwhile, a connection opening 19 for receiving a connection member 21 (cylindrical portion 22) is formed on the upper surface (motor installation surface) of the valve body 12 on which the electric motor 41 is installed, and a female thread 19a that screws onto the male thread 25 is formed on the inner peripheral surface of this connection opening 19. The connection opening 19 also has a step 19b against which the connection member 21 (cylindrical portion 22) abuts. The connection member 21 is screwed into the connection opening 19 with the male thread 25 on its outer peripheral surface screwed into the female thread 19a on the inner peripheral surface of the connection opening 19, but is stopped when the lower end of the cylindrical portion 22 abuts against the step 19b, and is fixed to the valve body 12. In this fixed state, the entire cylindrical portion 22 is not recessed into the connection opening 19, but rather the upper portion of the cylindrical portion 22 protrudes upward from the connection opening 19.

[0037] Of the cylindrical portion 22, the portion 22a disposed (recessed) inside the connection opening 19 is referred to as the "insertion portion," and the portion 22b protruding upward from the connection opening 19 is referred to as the "protrusion." Furthermore, by fixing the connection 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 seal member 30 (described later) is disposed in this gap.

[0038] The electric motor 41 is configured as a stepping motor equipped with a stator 42 arranged outside the can 40, a rotor 43 arranged rotatably inside the can 40, and a resin molded cover (housing) 56 that covers the can 40 and the stator 42. The resin molded cover 56 has, at its lower end, cylindrical legs 56a that surround the protrusion 22b and flange portion 23 of the connecting member 21 at a fixed interval.

[0039] A seal member 30 is provided so as to be interposed between the inner peripheral surface of the leg portion 56a and the outer peripheral surface of the protrusion 22b, and also between the lower surface of the flange portion 23 and the upper surface of the valve body 12. This seal member 30 is an elastic, ring-shaped resin member, and is provided with a ring-shaped protrusion 30a that extends around the entire circumference of the member 30 and protrudes outward from the outer peripheral surface of the member 30. In installation, when the connecting member 21 is screwed into the connection opening 19, the seal member 30 may be disposed on the outer peripheral surface of the tubular portion 22 so as to be sandwiched between the flange portion 23 and the upper surface of the valve body 12.

[0040] The height (vertical dimension) of the seal member 30 is set 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 connection opening 19 (when the lower end of the tubular portion 22 abuts against the step portion 19b). When the lower end of the connecting member 21 (tubular portion 22) is screwed into the connection opening 19 and stops against the step portion 19b, the seal member 30 is sandwiched between the flange portion 23 and the valve body 12 and crushed (compressed) at a predetermined (pre-designed) compression ratio. This seals the gap between the flange portion 23 and the upper surface of the valve body 12, preventing refrigerant from leaking from the valve chamber 13 to the outside or outside air from entering the valve chamber 13 from the outside. This provides the first sealing function.

[0041] Furthermore, similar to the height dimension, the thickness dimension (horizontal dimension) of the seal member 30, i.e., the distance between the inner peripheral surface of the seal member 30 in contact with the outer peripheral surface of the cylindrical portion 22 and the tip of the protruding portion 30a, is set larger than the distance between the inner peripheral surface of the leg portion 56a of the resin molded cover 56 and the outer peripheral surface of the cylindrical portion 22 (protruding portion 22b). Therefore, when the resin molded cover 56 containing the stator 42 is attached to the can 40, the protruding portion 30a of the seal member 30 is pressed against the inner peripheral surface of the leg portion 56a of the resin molded cover 56, and at the same time, the inner peripheral surface of the seal member 30 is pressed against the outer peripheral surface of the cylindrical portion 22 (protruding portion 22b). This seals the gap between the cylindrical portion 22 (protruding portion 22b) and the leg portion 56a of the resin molded cover 56, preventing moisture from entering the interior of the electric motor 41 (inside the resin molded cover) from the outside. In other words, the second sealing function can be achieved.

[0042] According to this embodiment, it is possible to use a single seal member 30 in place of the two seal members (first seal member 73 and second seal member 74) that were previously provided, thereby reducing the number of parts and the labor required during manufacturing.

[0043] Although the seal member 30 of this embodiment has both the first and second sealing functions, a seal member having only the second sealing function (i.e., a member that seals between the protrusion 22b and the leg 56a) may be used in place of the seal member 30. In this case, since a seal member having the first sealing function must be used separately, for example, a seal member (second seal member) that seals between the outer peripheral surface of the connection member 21 and the inner peripheral surface of the connection opening 19 of the valve body 12 with the connection member 21 attached to the valve body 12 may be used (the same applies to the second and third embodiments described later).

[0044] The can 40 is joined to the upper surface of the flange portion 23. In this embodiment, the connecting member 21 is provided with the flange portion 23 having a ring-like shape similar to the base member 75 (see FIG. 11) that has been conventionally used, so the base member 75 is not necessary.

[0045] The stator 42, which is disposed outside the can 40, includes a yoke 44 and a coil 46 wound around a bobbin 45. On the other hand, the rotor 43, which is disposed inside the can 40, is configured by integrally connecting a cylindrical rotor member 43a made of a magnetic material (permanent magnet) and a sun gear member 48 made of a resin material.

[0046] The shaft 44 is inserted into the center of the sun gear member 48 , and the upper part of the shaft 44 is supported by a support member 47 arranged inside the top of the can 40 .

[0047] The sun gear 48a of the sun gear member 48 meshes with a plurality of planetary gears 49 that are rotatably supported on a shaft 52 that is provided on a carrier 53 that is placed on the bottom surface of the output gear 54. The upper parts of the planetary gears 49 mesh with an annular ring gear (internal tooth fixed gear) 50 that is attached to the upper part of a cylindrical member 39 that is fixed to the upper part of a screw bearing 31 (described later), and the lower parts of the planetary gears 49 mesh with an internal tooth gear 51 of the annular output gear 54. The number of teeth of the ring gear 50 and the number of teeth of the internal tooth gear 51 of the output gear 54 are slightly different, so that the rotation speed of the sun gear 48a is reduced at a large reduction ratio and transmitted to the output gear 54. These gear mechanisms (sun gear 48a, planetary gear 49, ring gear 50, and output gear 54) constitute a speed reduction mechanism (paradox planetary gear speed reduction mechanism) 55 that reduces the rotation of the stepping motor 41 described above.

[0048] A cylindrical screw bearing 31 is fixed to the upper part of the connecting member 21 by press-fitting it into the enlarged diameter portion 24 so that it abuts against the lower end of the enlarged diameter portion 24 (the screw bearing 31 is inserted into the cylindrical portion 22 in a state where the cylindrical portion 22 is pressed in the diameter-expanding direction by the screw bearing 31). The screw bearing 31 is a thick cylindrical member, and press-fitting such a rigid part increases the strength of the connecting member 21, which has a relatively thin wall, and makes it possible to suppress radial deformation.

[0049] Therefore, according to this embodiment, it is possible to prevent a situation in which the connecting member 21 deforms in the radial direction due to pressure fluctuations during use of the valve, causing a change in the compression rate of the sealing member 30 and a decrease in sealing performance. Furthermore, although the can 40 is joined to the connecting member 21 (flange portion 23), it is possible to prevent a situation in which the diameter of the flange portion 23 changes due to a change in the diameter of the tubular portion 22, causing a change in the inner diameter of the can 40 and causing the rotor 43 to rub against the inner surface of the can 40, thereby hindering rotation.

[0050] The output gear 54 is in slidable contact with the upper surface of the screw bearing 31. The upper part of the stepped cylindrical output shaft 38 is press-fitted into the center of the bottom of the output gear 54, and the lower part of the output shaft 38 is rotatably inserted into a fitting hole 31a formed in the center of the upper surface of the screw bearing 31. The lower end of the shaft 44 is fitted into the upper part of the output shaft 38 so as to be rotatable relative to the output shaft 38.

[0051] A female threaded portion 31b is formed in the lower center portion of the screw bearing 31, and a male threaded portion 32b formed on the outer peripheral surface of the screw drive member 32 is threadedly engaged with this female threaded portion 31b. The screw bearing 31 (feed screw portion 31b) and the screw drive member 32 (male threaded portion 32b) constitute a transmission mechanism (feed screw mechanism) 33 that converts the rotational motion supplied from the stepping motor 41 via the reduction mechanism 55 into linear motion in the vertical direction and transmits it to the valve element 17.

[0052] Here, the output gear 54 rotates at a fixed position in the vertical direction without moving up and down, and a flat screwdriver-shaped plate portion 32a provided at the upper end of the screw drive member 32 is inserted into a 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 screw drive member 32. As the plate portion 32a provided on the screw drive member 32 slides up and down within the fitting groove 38a of the output shaft 38, when the output gear 54 (rotor 43) rotates, the screw drive member 32 moves linearly up and down by the feed screw mechanism 33, even though the output gear 54 does not move up and down.

[0053] The linear motion of this screw drive member 32 is transmitted to the valve element 17 via a ball joint 35 consisting of a ball 34a and a ball seat 34b, and a spring receiving member 36. The valve element 17 is composed of a valve element main body 17a that moves toward and away from the valve seat 14, and a stepped, cylindrical valve element support portion 17b that rises upward from the center of the upper surface of the valve element main body 17a, and the spring receiving member 36 and the valve element 17 (valve element support portion 17b) are connected by inserting the upper end of the valve element support portion 17b into a fitting hole (lower surface fitting hole) 36b formed in the center of the lower surface of the spring receiving member 36. In addition, a fitting hole (upper surface fitting hole) 36a is also formed in the center of the upper surface of the spring receiving member 36, and the ball seat 34b is fitted into this upper surface fitting hole 36a.

[0054] Furthermore, a valve element guide member 18 is fixed to the bottom surface of the connection opening 19 on the top surface of the valve body, thereby closing the top surface of the valve chamber 13. A stepped through-hole is formed in the center of the valve element guide member 18, which is fixed to the top of the valve chamber 13, through which the valve element support portion 17b passes so as to be able to slide up and down, and in which a compression coil spring 37 is installed. The compression coil spring 37 is provided between the step at the top of the through-hole and the spring receiving member 36. This compression coil spring 37 biases the valve element 17 upward, which is the valve opening direction, and by applying the biasing force of the coil spring 37 to the valve element 17 in addition to the driving force of the electric motor 41 during the valve opening operation, it is possible to more reliably perform the valve opening operation.

[0055] In this embodiment, the central axes of the valve body 17, valve seat 14, valve body guide member 18, connecting member 21, screw bearing 31, screw drive member 32, output shaft 38, shaft 44, and rotor 43 coincide with the axis A of the electric valve 11, which extends vertically in the up-down direction.

[0056] The operation of the motor-operated valve 11 according to this embodiment will be described as follows.

[0057] When current is supplied to the stator 42 (coil 46) so that the rotor 43 rotates in one direction from the closed valve state shown in Figure 1, the rotation of the rotor 43 is converted into linear motion by the feed screw mechanism 33, and the screw drive member 32 is pulled upward. Accordingly, the spring seat 36, which is pressed against the underside of the screw drive member 32 via the ball joint 35 by the biasing force of the compression coil spring 37, and the valve body support portion 17b connected to the spring seat 36 are pulled upward, causing the valve body portion 17a to separate from the valve seat 14, and the refrigerant that has flowed in from the inlet passage 15 passes through the valve chamber 13 and flows out from the outlet passage 16 (see Figure 2). The amount of refrigerant passing through (refrigerant flow rate) in this open valve state can be adjusted by the amount of rotation of the rotor 43.

[0058] On the other hand, when current is supplied to the stator 42 (coil 46) so that the rotor 43 rotates in the opposite direction from the open valve state, the rotation of the rotor 43 is converted into linear motion by the feed screw mechanism 33, and the screw drive member 32 moves downward. As this downward movement occurs, the ball joint 35, spring bearing member 36, and valve body 17 move downward, and when the valve body main body 17a abuts against the valve seat 14, the flow path between the inlet channel 15 and the outlet channel 16 is blocked, and the valve is closed (see Figure 1).

[0059] Second Embodiment A motor-operated valve according to a second embodiment of the present invention will be described with reference to Figures 5 to 7. Note that the same components as those in the motor-operated valve of the first embodiment will be assigned the same reference numerals, and duplicated explanations will be omitted, with differences being mainly described.

[0060] As shown in Figures 5 to 7, 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 configured as an integrated part (connecting member 21a having a valve body guide portion 28).

[0061] Specifically, similar to the first embodiment, the overall shape of the connecting member 21a is formed by press working, and then the necessary cutting work is performed to produce the connecting member 21a. However, as shown in FIG. 6, the cylindrical member 20a formed by press working has, in addition to the tubular 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 tubular portion 22, and a valve body guide portion 28 extending downward from the lower end of the reduced diameter portion 26.

[0062] The reduced diameter portion 26 has a smaller diameter than the cylindrical portion 22, and therefore a step 27 is formed between the cylindrical portion 22 and the reduced diameter portion 26. Similar to the lower end of the cylindrical portion 22 in the first embodiment, this step 27 abuts against a step 19b formed on the inner peripheral surface of the connection opening 19, thereby functioning to set the vertical compression rate of the seal member 30 to an appropriate value. Note that the lower surface of the step 27 that abuts against the step 19b is flattened during the cutting process described below (see FIG. 7). Similarly to the valve element guide member 18 (see FIG. 1), the valve element guide portion 28 abuts against the valve element support portion 17b to allow vertical movement.

[0063] After the cylindrical member 20a is formed, an enlarged diameter portion 24 is formed at the upper end of the cylindrical portion 22, and a male thread 25 is formed on the outer peripheral surface of the lower end of the cylindrical portion 22, by cutting, as shown in Figure 7. The enlarged diameter portion 24 and the male thread 25 have the same functions as in the first embodiment. Furthermore, in this embodiment, a flat spring receiving surface 29 is formed at the upper end of the valve body guide portion 28 (at the boundary between the reduced diameter portion 26 and the valve body guide portion 28) by cutting, so that a compression coil spring 37 can be received therein.

[0064] According to this embodiment, the valve body guide member 18 can be molded integrally with the connecting member 21a as the valve body guide portion 26 molded at the lower end of the connecting member 21a, which makes it possible to further reduce the number of parts and the number of manufacturing steps compared to the first embodiment.

[0065] Third Embodiment A motor-operated valve according to a third embodiment of the present invention will be described with reference to Figures 8 to 10. Note that the same components as those in the motor-operated valves of the first and second embodiments will be assigned the same reference numerals, and redundant explanations will be omitted, with differences being mainly described.

[0066] As shown in Figures 8 to 10, the motor-operated valve 62 of this embodiment adjusts the flow rate of the refrigerant by moving the valve element 17a up and down using an electric motor (stepping motor) 41, as in the first embodiment, but is equipped with a rod-shaped valve shaft 63 that extends vertically along the axis A from the inside of the rotor 43 to the valve chamber 13 and has the valve element 17a at its lower end, and has a structure in which the valve element 17a (valve shaft 63) is connected to the rotor 43 without via a reduction mechanism (paradox planetary gear reduction mechanism).

[0067] More specifically, the valve shaft 63 has a cylindrical body 63a and an upper small-diameter portion 63b with a small outer diameter that is formed coaxially with and continues from the upper end of the body 63a. The valve disc 17a is integrally provided at the lower end of the valve shaft 63 (body 63a). The rotor 43 is rotatably and vertically movable within the can 40, and the valve is opened and closed by the vertical movement of the valve shaft 63, which has the valve disc 17a at its lower end, and the rotor 43.

[0068] A valve stem holder 64 is provided inside the rotor 43. The valve stem holder 64 has a cylindrical shape with a closed upper end, and a support ring 65 is fixed to the upper end of the valve stem holder 64 by crimping. The rotor 43 and the valve stem holder 64 are joined together via the support ring 65. A female thread portion 64a is formed on the inner circumferential surface of the valve stem holder 64. This female thread portion 64a is threadedly engaged with a male thread portion 68c of a guide bush 68 (described later) to form a transmission mechanism (feed screw mechanism) that converts the rotation of the electric motor 41 into linear motion and transmits it to the valve stem 63.

[0069] The upper small diameter portion 63b of the valve stem 63 passes through the valve stem holder 64, and a push nut 66 is attached to the upper end of the upper small diameter portion 63b to prevent it from coming off. The valve stem 63 is urged downward by a compression coil spring 67 provided between the valve stem holder 64 and a step between the body portion 63a and the upper small diameter portion 63b of the valve stem 63. Therefore, the relative movement of the valve stem 63 in the up and down direction with respect to the valve stem holder 64 is restricted by the push nut 66 and the compression coil spring 67, and the valve stem 63 moves up and down together with the valve stem holder 64.

[0070] As in the first and second embodiments, the connecting member 21b is fabricated by forming the overall shape by press working and then performing the necessary cutting. As shown in FIG. 9 , the cylindrical member 20b formed by press working includes the tubular portion 22 and flange portion 23 similar to those in the first embodiment, and also includes a valve element guide portion 28 similar to those in the second embodiment. The valve element guide portion 28 is formed at the bottom of the tubular portion 22 and supports the valve stem 63 so that it can move up and down. The valve element guide portion 28 has a smaller diameter than the tubular portion 22, and a step portion 27 is formed between the tubular portion 22 and the valve element guide portion 28, allowing this step portion 27 to abut against the step portion 19b of the connecting opening 19. Furthermore, according to this embodiment, the valve element guide portion 28 is integrally formed with the connecting member 21b, thereby reducing the number of parts and manufacturing steps compared to the first embodiment.

[0071] After the cylindrical member 20b is formed, as shown in Fig. 10, an expanded diameter portion 24 is formed on the inside of the upper end of the cylindrical portion 22, and a male thread 25 is formed on the outer peripheral surface of the lower end of the cylindrical portion 22 by cutting. The expanded diameter portion 24 and the male thread 25 have the same functions as those in the first and second embodiments.

[0072] A guide bush 68, which serves as a rigid component according to the present invention, is press-fitted and fixed into the expanded diameter portion 24 of the connecting member 21b. The guide bush 68 has a large-diameter cylindrical portion 68a with a large outer diameter and a small-diameter cylindrical portion 68b with a small outer diameter formed coaxially above and continuous with the large-diameter cylindrical portion 68a. A male thread portion 68c that threads with the female thread portion 64a of the valve stem holder 64 is formed on the outer circumferential surface of the small-diameter cylindrical portion 68b.

[0073] Furthermore, the stem holder 64 is provided with an upper stopper body 69, while the large-diameter cylindrical portion 68a of the guide bush 68 is provided with a lower stopper body 70. These stopper bodies 69, 70 determine the lower limit position of the stem holder 64. When the stem holder 64 rotates and descends to reach the lower limit position, the upper stopper body 69 abuts against the lower stopper body 70, restricting further rotation of the stem holder 64.

[0074] Furthermore, in this embodiment, the valve body 12 comprises a main body 12a having a valve chamber 13 therein and into which a connecting member 21b is screwed and fixed, and a flow path block (not shown) having an inlet and outlet passages therein and into which the main body 12a is screwed and fixed. Note that the inlet hole 15a and the 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 path block, respectively, when the main body 12a is screwed into the flow path block. The seal member 30 has the same structure and function as those in the first and second embodiments.

[0075] The operation of the motor-operated valve 62 according to this embodiment will be described as follows.

[0076] When current is supplied to the stator 42 (coil 46) so that the rotor 43 rotates in one direction from the closed valve state shown in Figure 8, the stem holder 64 connected to the rotor 43 rotates together with the rotor 43. The inner circumferential surface of the stem holder 64 is formed with a female thread 64a that threadably engages with a male thread 68c formed on the outer circumferential surface of the small-diameter cylindrical portion 68b of the guide bush 68. The interaction between the male thread 68c and the female thread 64a converts the rotation of the rotor 43 (stem holder 64) into linear motion in the vertical direction, causing the stem holder 64 to move upward. As a result, the rotor 43 connected to the stem holder 64 and the stem 63, whose relative movement with the stem holder 64 is restricted, also move upward together with the stem holder 64. As the stem 63 moves upward, the valve element 17a provided at the lower end of the stem 63 separates from the valve seat 14, allowing refrigerant flowing in from the inlet passage to flow through the valve chamber 13 and out from the outlet passage. The amount of refrigerant passing through (refrigerant flow rate) can be adjusted by the amount of rotation of the rotor 43.

[0077] On the other hand, when current is supplied to the stator 42 (coil 46) so that the rotor 43 rotates in the opposite direction from the open valve state, the rotation of the rotor 43 (valve stem holder 64) is converted into vertical linear motion by the interaction between the female thread portion 64a and the male thread portion 68c, and the valve stem holder 64 moves downward together with the rotor 43 and valve stem 63. This causes the valve element 17a to descend toward the valve seat 14, and when the valve element 17a abuts against the valve seat 14, the valve is in the closed state shown in Figure 8. [Explanation of symbols]

[0078] A axis (center axis) 11,61,62,71,81 Motor-operated valve 12 Valve body 12a Main body of valve body 13 Valve chamber 14 Valve seat 15 Inflow channel 15a Inlet hole 16 Outflow channel 16a Outflow hole 17,17a Valve body 17b Valve body support part 18 Valve body guide member 19 Connection opening 19a female thread 19b Stepped section 20, 20a, 20b cylindrical members 21, 21a, 21b, 72 connecting member 22 Cylindrical part 22a Insertion part 22b Projection 23 Flange part (brim part) 24 Expanded diameter part 25 male thread 26 Reduced diameter part 27 Step 28 Valve body guide part 29 Spring bearing surface 30 Sealing material 30a convex part 31 Screw bearings 31a insertion hole 31b Female thread 32 Screw drive member 32a Plate-shaped part 32b Male thread 33 Transmission mechanism (feed screw mechanism) 34a Ball 34b Ball seat 35 Ball joint 36 Spring support member 37,67 Compression coil spring 38 Output shaft 38a Fitting groove 39 Cylindrical member 40 Cans (sealed containers) 41 Electric motor (stepping motor) 42 Stator 43 Rotor 43a Rotor member 44 York 45 bobbin 46 Coil 47 Support member 48 Sun gear parts 48a Sun Gear 49 Planetary Gear 50 Ring gear (internal tooth fixed gear) 51 Internal gear 52 Shaft 53 Career 54 Output gear 55 Reduction mechanism (paradoxical planetary gear reduction mechanism) 56 Resin mold cover (stator housing) 56a Cylindrical leg 63 Valve stem 63a Torso 63b Upper small diameter section 64 Valve stem holder 64a female thread 65 Support ring 66 Push nut 68 Guide bush 68a Large diameter cylindrical part 68b Small diameter cylindrical part 68c male thread 69 Upper stopper body 70 Lower stopper body 73 First seal member 74 Second seal member 75 Base material

Claims

1. a valve body having a valve chamber therein that communicates with an inlet passage and an outlet passage; a valve body that moves toward and away from a valve seat formed in the valve chamber; an electric motor having a rotor and a stator that drives the valve body; a can that houses the rotor inside and arranges the stator outside; a connecting member that connects the can and the valve body; a seal member that extends to surround the connection member and that presses against an outer circumferential surface of the connection member and an inner circumferential surface of the housing of the stator; An electrically operated valve comprising: The connecting member is It is formed by pressing, It has a cylindrical portion, A rigid part is inserted into the cylindrical part, the valve body has a connection opening to which the connection member is fixed, The cylindrical portion is an insertion portion disposed within the connection opening; a protruding portion protruding from the connection opening toward the electric motor; a flange portion extending outward from the protrusion portion so as to face the valve body with a gap therebetween; and The seal member is further disposed between the valve body and the flange. A motor-operated valve characterized by:

2. The seal member is in pressing contact with the valve body and the flange. The motor-operated valve according to claim 1 .

3. The can is fixed to the flange. The motor-operated valve according to claim 2.

4. The connection opening has an internal thread on its inner circumferential surface, the insertion portion has a male thread on its outer circumferential surface that screws into the female thread, and is fixed to the valve body by being screwed into the connection opening; the connection opening has a stopper portion against which the insertion portion, which is screwed into the connection opening and moves in the depth direction of the connection opening, can strike and stop; When the insertion portion abuts against the stopper portion, the seal member abuts against the valve body and the flange portion in a pressed state. The motor-operated valve according to claim 2.

5. The seal member has a protrusion on its outer circumferential surface that abuts against the inner circumferential surface of the housing.

5. The motor-operated valve according to claim 1.

6. The connecting member is a valve element guide portion that is integrally formed with the cylindrical portion by press working and supports the valve element so that it can move toward and away from the valve seat; Equipped with 5. The motor-operated valve according to claim 1.

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