Motorized valve

Abstract

A motorized valve according to the present invention comprises: a gear-type reduction mechanism that has an output shaft and a resin output gear having a bottom portion in which a through hole is formed into which one end of the output shaft is fitted, and that reduces and outputs the rotation of the motor, the output shaft having a push-out portion at one end that pushes out a resin piece of a gate formed inside the through hole of the output gear, and a groove being formed circumferentially on the other end side from the push-out portion in the axial direction of the output shaft; and a valve body that controls the opening degree of the valve by rotating the output of the gear-type reduction mechanism.

Description

Electric valve

[0001] The present disclosure relates to motorized valves.

[0002] Conventionally, there is known an electrically operated valve including a gear-type reduction mechanism having an output gear and an output shaft, as disclosed in Japanese Patent Application Laid-Open No. 2009-185877. The output gear in Japanese Patent Application Laid-Open No. 2009-185877 is made of resin and has a cylindrical shape with a bottom. A through hole is formed in the bottom of the output gear. The output shaft is made of metal. The output shaft and the output gear are assembled integrally by press-fitting the output shaft into the through hole of the output gear.

[0003] A resin output gear can be manufactured by, for example, injection molding. A mold for manufacturing the output gear has a gate disposed at a location corresponding to the inner circumferential surface of the through hole at the bottom. Therefore, after injection molding, a resin piece remaining at the gate is formed inside the through hole of the output gear, adhering to the inner circumferential surface of the through hole so as to cover the through hole. When the output shaft and the output gear are assembled, the resin piece remaining at the gate is pushed out by one end of the output shaft that is press-fitted into the through hole, and is separated from the inner circumferential surface of the through hole. In other words, the resin piece is scraped off from the inner circumferential surface and expelled from the inside to the outside of the through hole.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-185877

[0005] In Japanese Patent Application Laid-Open No. 2009-185877, when resin pieces remaining in the gate are discharged from the inside of the through-hole, resin shavings may be generated. The resin shavings may be, for example, granular or powdery. If the shavings are held between the outer peripheral surface of the output shaft and the inner peripheral surface of the through-hole and exposed to the inside of the output gear, malfunction of the gear-type reduction mechanism may occur.

[0006] For example, shavings float inside the can due to the lubricating oil, i.e., fluid containing machine oil, introduced into the gear-type reduction mechanism through the pressure equalizing hole. When the floating shavings enter the meshing portions of the gears that make up the gear-type reduction mechanism, they create a load resistance for the motor. As a result, the shavings can interfere with maintaining accurate motor operation or cause mesh locking. Furthermore, wear on the components that make up the gear-type reduction mechanism can generate new resin or metal shavings. For this reason, it is necessary to remove the shavings after assembling the output shaft and output gear.

[0007] In view of the above, the present disclosure provides an electric valve that can reduce the burden of removing shavings generated by assembling a resin output gear and an output shaft.

[0008] The electric valve of the first aspect is a gear-type reduction mechanism that has an output shaft and a resin output gear with a bottom having a through hole into which one end of the output shaft fits, and that reduces the rotation of a motor before outputting it, wherein the output shaft has an extrusion portion at one end that extrudes a resin piece of a gate formed inside the through hole of the output gear, and the gear-type reduction mechanism has a groove portion formed circumferentially on the other end side of the extrusion portion in the axial direction of the output shaft, and a valve body that controls the opening degree of the valve by the rotation of the output of the gear-type reduction mechanism.

[0009] In the electric valve of the first aspect, when assembling the output shaft and the output gear, even if resin shavings are generated by pushing out resin pieces of the gate formed inside the through hole of the output gear by the extrusion section, the shavings can be contained between the outer surface of the groove section of the output shaft and the inner surface of the through hole.

[0010] In a second aspect, in the electric valve according to the first aspect, a protrusion extending along the axial direction is provided on the outer peripheral surface of the output shaft on the side of the other end of the output shaft in the axial direction of the groove portion, and is positioned radially outward from the inner peripheral surface of the through hole.

[0011] In the second aspect, even if an amount of shavings is formed that exceeds the capacity of the groove portion, the shavings can be held between the protrusion and the inner surface of the through hole, and therefore the shavings can be prevented from moving axially toward the extrusion portion rather than the groove portion, compared to when the shavings are held by the groove portion alone.

[0012] In a third aspect, in the electric valve according to the first or second aspect, the gate position where the resin piece is formed on the inner surface of the through hole is located closer to the one end than the groove portion in the axial direction of the output shaft, and the radial depth of the groove portion becomes deeper from the one end side toward the other end side in the axial direction when viewed in cross section.

[0013] In the third aspect, for example, when the output gear is positioned above the output shaft with the axial direction aligned vertically, the groove portion is positioned below the gate position, so that even if shavings generated from the gate position fall, they can easily be contained by the groove portion.

[0014] In a fourth aspect, in the motor-operated valve according to any one of the first to third aspects, the groove portion has an arc shape in cross section.

[0015] In the fourth aspect, the grooves can be processed and formed more easily than when grooves having a triangular or rectangular cross-sectional shape are formed.

[0016] In a fifth aspect, in the motor-operated valve according to any one of the first to fourth aspects, shavings are contained between an outer peripheral surface of the groove portion and an inner peripheral surface of the through hole.

[0017] In the fifth aspect, the shavings contained in the grooves are mixed with, for example, the fluid refrigerating machine oil, which makes it easier to retain the refrigerating machine oil inside the grooves.

[0018] In a sixth aspect, in the electric valve according to any one of the first to fifth aspects, the groove portion has, in a cross-sectional view, a groove bottom portion that is located at the innermost radial position of the through hole, an introduction wall portion that continues from the radial outside to the groove bottom portion and introduces shavings to the groove bottom portion, and a return wall portion that is located on the opposite side of the introduction wall portion across the groove bottom portion in the axial direction and prevents the stored shavings from leaking out of the groove portion.

[0019] In the sixth aspect, the groove is provided with an introduction wall that is continuous from the radial outside to the groove bottom and that introduces the shavings to the groove bottom, making it easy to introduce the shavings to the groove bottom. Also, the groove is provided with a return wall that prevents the shavings from leaking out of the groove, making it easy to keep the shavings inside the groove.

[0020] In a seventh aspect, in the electric valve according to any one of the first to sixth aspects, a protrusion extending along the axial direction is provided on the outer peripheral surface of the output shaft on the side of the other end of the output shaft closer to the groove portion in the axial direction, and is positioned radially outward from the inner peripheral surface of the through hole, and shavings contained between the outer peripheral surface of the groove portion and the inner peripheral surface of the through hole are extruded along the axial direction by the protrusion, forming a line from the inner peripheral surface of the through hole of the output gear.

[0021] In the seventh aspect, the shavings formed in a line by the ridges can be contained inside the grooves.

[0022] According to the present disclosure, it is possible to provide an electric valve that can reduce the burden of removing shavings generated by assembling a resin output gear and an output shaft.

[0023] FIG. 1 is a cross-sectional view illustrating a motor-operated valve according to an embodiment of the present disclosure, cut by a plane including a central axis which is a rotation axis. FIG. 1 is a cross-sectional view illustrating an output gear and an output shaft of a motor-operated valve according to an embodiment. FIG. 2 is a side view illustrating the output shaft of a motor-operated valve according to an embodiment. FIG. 3 is a cross-sectional view illustrating a method of assembling the output gear and the output shaft of a motor-operated valve according to an embodiment. FIG. 4 is a plan view of the output gear, illustrating a method of assembling the output gear and the output shaft of a motor-operated valve according to an embodiment. FIG. 5 is a cross-sectional view illustrating a method of assembling the output gear and the output shaft of a motor-operated valve according to an embodiment. FIG. 6 is a cross-sectional view illustrating an enlarged groove of an output shaft of a motor-operated valve according to an embodiment. FIG. 7 is a cross-sectional view illustrating an enlarged groove of an output shaft of a motor-operated valve according to a first modified example. FIG. 8 is a cross-sectional view illustrating an enlarged groove of an output shaft of a motor-operated valve according to a second modified example. FIG. 9 is a cross-sectional view illustrating an enlarged groove of an output shaft of a motor-operated valve according to a third modified example. FIG. 10 is a cross-sectional view illustrating an enlarged groove of an output shaft of a motor-operated valve according to a fourth modified example. FIG. 11 is a cross-sectional view illustrating an enlarged groove of an output shaft of a motor-operated valve according to a fifth modified example.

[0024] This embodiment will be described below. In the following description of the drawings, identical or similar parts are designated by the same or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each device or component, etc. may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, there may be parts with different dimensional relationships and ratios between the drawings. Furthermore, unless otherwise specified in the specification, the number of each component element of the present disclosure is not limited to one, and multiple elements may be present.

[0025] <Configuration of Motor-Operated Valve> The motor-operated valve 1 according to this embodiment will be described below mainly with reference to Figures 1 to 3. The motor-operated valve 1 according to this embodiment is used, for example, to control the flow rate of a fluid in an automotive air conditioner. The fluid is, for example, a high-pressure refrigerant.

[0026] As shown in FIG. 1, the motor-operated valve 1 according to this embodiment includes a valve body 10, a holder 20, a valve body support member 25, a can 30, a drive mechanism 40, a valve body 70, and a stator unit 80.

[0027] (Valve Body) The valve body 10 has a rectangular parallelepiped shape. The valve body 10 has a valve chamber 13 and a valve port 14 connected to the valve chamber 13. The valve body 10 has a first passage 17 and a second passage 18. One end of the first passage 17 is connected to the valve chamber 13. The other end of the first passage 17 opens to the left side surface 10A of the valve body 10. One end of the second passage 18 is connected to the valve chamber 13 via the valve port 14. The other end of the second passage 18 opens to the right side surface 10B of the valve body 10. The valve body 10 has a mounting hole 19. The mounting hole 19 opens to the top surface 10C of the valve body 10. A female thread is formed on the inner circumferential surface of the mounting hole 19. The valve chamber 13 opens to a bottom surface 19A of the mounting hole 19.

[0028] The holder 20 has a cylindrical shape. A male thread is formed on the lower part of the outer circumferential surface of the holder 20 in Fig. 1. The male thread of the holder 20 is screwed into the female thread of the mounting hole 19 of the valve body 10. The holder 20 is attached to the valve body 10 by a screw structure.

[0029] The valve element support member 25 has a cylindrical shape. The valve element support member 25 is disposed inside the mounting hole 19, between the valve body 10 and the holder 20. The lower part of the valve element support member 25 in FIG. 1 is press-fitted into the valve chamber 13 from the mounting hole 19 side. An annular flat surface 25A facing downward in FIG. 1 is formed on the outer circumferential surface of the valve element support member 25. The annular flat surface 25A abuts against the bottom surface 19A of the mounting hole 19. The valve element support member 25 supports the valve element 70 in FIG. 1 so that it can move up and down.

[0030] The can 30 has a cylindrical shape with a closed upper end and an open lower end in Fig. 1. The lower end of the can 30 in Fig. 1 is joined to the outer periphery of a joining member 35 in the shape of an annular disk. The upper part of the holder 20 is disposed inside the joining member 35. The inner periphery of the joining member 35 is joined to the holder 20.

[0031] (Drive Mechanism) The drive mechanism 40 of this embodiment moves the valve body 70 in the up and down direction in Fig. 1. The drive mechanism 40 has a magnet rotor 41, a planetary gear mechanism 50, a guide member 60, a drive shaft 65, and a ball 68.

[0032] The magnet rotor 41 has a cylindrical shape. North and south poles are arranged alternately in the circumferential direction on the outer peripheral surface of the magnet rotor 41. The outer diameter of the magnet rotor 41 is smaller than the inner diameter of the can 30. The magnet rotor 41 is rotatably arranged inside the can 30. A disk-shaped connecting member 42 is joined to the upper end of the magnet rotor 41 in FIG. 1. The connecting member 42 closes the upper end of the magnet rotor 41 in FIG. 1. The rotor shaft 43 passes through the center of the connecting member 42. The magnet rotor 41 is connected to the rotor shaft 43 via the connecting member 42.

[0033] The planetary gear mechanism 50 is a gear-type reduction mechanism of the present disclosure that reduces the rotation of the motor and outputs it. The valve body 10 controls the valve opening degree by the rotation of the output of the planetary gear mechanism 50. The planetary gear mechanism 50 is disposed inside the magnet rotor 41. The planetary gear mechanism 50 has a gear case 51, a fixed ring gear 52, a sun gear 53, multiple planet gears 54, a carrier 55, an output gear 56, and an output shaft 57.

[0034] The gear case 51 has a cylindrical shape. The gear case 51 is coaxially joined to the upper end of the holder 20 in FIG. 1. The fixed ring gear 52 is an internal gear. The fixed ring gear 52 is fixed to the upper end of the gear case 51 in FIG. 1. The sun gear 53 is arranged coaxially with the connecting member 42. The sun gear 53 is integrated with the connecting member 42. The rotor shaft 43 passes through the sun gear 53. The sun gear 53 rotates together with the magnet rotor 41 and the connecting member 42.

[0035] The plurality of planetary gears 54 are disposed between the fixed ring gear 52 and the sun gear 53. The carrier 55 has a disk shape. The rotor shaft 43 passes through the center of the carrier 55. The carrier 55 is rotatable around the rotor shaft 43. The carrier 55 has a plurality of support shafts 55A. The plurality of support shafts 55A rotatably support the plurality of planetary gears 54. The output gear 56 has a cylindrical shape with a bottom.

[0036] The output gear 56 is an internal gear. A plurality of planetary gears 54 are arranged between the output gear 56 and the sun gear 53. An output shaft 57 is assembled to the output gear 56. The rotation of the sun gear 53 is reduced in speed by the fixed ring gear 52, the plurality of planetary gears 54, the carrier 55, and the output gear 56, and then transmitted to the output shaft 57.

[0037] The guide member 60 has a cylindrical shape. The guide member 60 is disposed inside the upper part of the holder 20 in FIG. 1. A female screw is formed on the lower part of the inner circumferential surface of the guide member 60 in FIG. 1. The output shaft 57 is disposed inside the guide member 60. The guide member 60 rotatably supports the output shaft 57.

[0038] The drive shaft 65 integrally has a cylindrical portion 66 and a flat plate portion 67. The flat plate portion 67 is connected to the upper end of the cylindrical portion 66. A male thread is formed on the outer circumferential surface of the cylindrical portion 66. The male thread of the cylindrical portion 66 is threadedly engaged with the female thread of the guide member 60. The flat plate portion 67 is disposed in the slit 57A of the output shaft 57 so as to be movable in the vertical direction in FIG. 1. The drive shaft 65 is rotated by the output shaft 57 and moves in the vertical direction in FIG. 1 by the screw feed action. The ball 68 is disposed between the drive shaft 65 and the ball receiver 74 of the valve body 70.

[0039] The valve body 70 has a stem 71, a valve portion 72, a spring receiving portion 73, and a ball receiving portion 74. The stem 71 has a cylindrical shape. The stem 71 is disposed inside the valve body support member 25. The stem 71 is supported by the valve body support member 25 so as to be movable in the up-down direction in FIG. 1. The valve portion 72 is disposed at the lower end of the stem 71 in FIG. 1. The valve portion 72 has an annular shape. The valve portion 72 protrudes radially outward from the outer peripheral surface of the stem 71. The valve portion 72 in FIG. 1 is disposed opposite the valve port 14 in the up-down direction.

[0040] The spring receiving portion 73 has a cylindrical shape. The spring receiving portion 73 is joined to the upper end of the stem 71 in FIG. 1. The spring receiving portion 73 has a flange portion 73A that protrudes radially outward. The ball receiving portion 74 in FIG. 1 has a circular flat portion and a protrusion connected to the underside of the flat portion. The flat portion of the ball receiving portion 74 is in contact with the ball 68. The protrusion of the ball receiving portion 74 is fitted into a hole formed in the spring receiving portion 73.

[0041] A valve-opening spring 75 is disposed between the flange portion 73A of the spring receiving portion 73 and the valve body support member 25. The valve-opening spring 75 is a compression coil spring. The valve-opening spring 75 presses the flange portion 73A of the valve body 70 upward in FIG. 1 . The valve body 70 changes the opening area of ​​the valve orifice 14 steplessly as the valve portion 72 moves forward and backward relative to the valve orifice 14. The valve body 70 may close the valve orifice 14. That is, the opening area may be zero.

[0042] The stator unit 80 has a stator 90 and a cover 95. The stator 90 has a cylindrical shape. The can 30 is disposed inside the stator 90. The cover 95 houses the stator 90. The stator unit 80, together with the magnet rotor 41, constitutes a stepping motor.

[0043] In the electric valve 1, the valve port 14, holder 20, valve body support member 25, can 30, magnet rotor 41, connecting member 42, rotor shaft 43, output gear 56, output shaft 57, guide member 60, drive shaft 65, valve body 70, and stator 90 all have the same central axis C.

[0044] (Output Gear) Next, the output gear 56 and the output shaft 57 will be specifically described with reference to FIGS. 2 and 3. The up-down direction in FIGS. 1 to 4 corresponds to the axial direction of the output shaft 57. The output gear 56 of this embodiment is made of a synthetic resin, such as polyphenylene sulfide (PPS). The output gear of the present disclosure may be made of a resin other than PPS. As shown in FIG. 2, the output gear 56 integrally has a peripheral wall portion 561 and a bottom portion 562. Note that in the present disclosure, for example, an output gear without a peripheral wall portion may be configured.

[0045] The peripheral wall portion 561 has a cylindrical shape. A plurality of internal gear teeth are formed on the inner peripheral surface of the peripheral wall portion 561. The peripheral wall portion 561 extends from the peripheral edge of the bottom portion 562 in the axial direction opposite the output shaft 57 (i.e., the upper side in FIG. 2). The bottom portion 562 has a disk shape. The bottom portion 562 is connected to the lower end of the peripheral wall portion 561 in FIG. 2. A circular through-hole 562A is formed in the center of the bottom portion 562, into which one end of the output shaft 57 (i.e., the upper end in FIG. 2) fits.

[0046] (Output Shaft) The output shaft 57 is rod-shaped. The output shaft 57 is made of a metal such as stainless steel. In the present disclosure, the material of the output shaft is arbitrary. As shown in FIGS. 2 and 3 , the output shaft 57 integrally has a connection portion 571, a stopper portion 572, and a press-fit end portion 573. The connection portion 571 has a cylindrical shape. The stopper portion 572 has a disk shape. The diameter of the stopper portion 572 is larger than the diameter of the connection portion 571. The stopper portion 572 is connected coaxially to the upper end of the connection portion 571 in FIG. 2 .

[0047] The press-fit end 573, which is the upper end of the output shaft 57 in FIG. 2, is press-fitted into the through-hole 562A of the output gear 56. In this embodiment, the press-fit end 573 has a cylindrical extrusion 573A, a groove 573E, and a protrusion 573B. In the present disclosure, the shape of the extrusion is not limited to a cylindrical shape and may be other geometric shapes, such as a polygonal prism. If the shape of the extrusion is, for example, a polygonal prism, the shape of the through-hole of the output gear may also be configured as a polygonal shape corresponding to the extrusion. The extrusion 573A, the groove 573E, and the protrusion 573B are aligned in this order from the top to the bottom of the press-fit end 573 in FIG. 2. In the present disclosure, the protrusion is not required.

[0048] The output shaft 57 has a slit 57A that extends upward from the lower end surface of the connecting portion 571. The output shaft 57 has a support hole 57B that extends downward from the upper end surface of the press-fit end portion 573. The lower end of the rotor shaft 43 is disposed inside the support hole 57B. The support hole 57B rotatably supports the lower end of the rotor shaft 43.

[0049] (Extrusion portion) The extrusion portion 573A is provided at one end of the output shaft 57. The extrusion portion 573A extrudes a resin piece of a gate formed inside the through-hole 562A of the output gear 56 when the output shaft 57 and the output gear 56 are assembled. The extrusion portion 573A has a circular cross section. The cross section is a cross section perpendicular to the axial direction. The extrusion portion 573A has a substantially constant diameter throughout the entire axial direction.

[0050] (Groove) The groove 573E extends in the circumferential direction. The groove 573E is formed closer to the other end (i.e., lower in FIG. 2 ) of the extruded portion 573A in the axial direction of the output shaft 57. The diameter of the output shaft 57 at the position where the groove 573E is formed is smaller than the diameter of the extruded portion 573A.

[0051] Specifically, the groove 573E of this embodiment has a horizontal surface whose outer edge is connected to the lower edge of the extrusion 573A in Fig. 2, an arc-shaped connecting surface whose upper edge is connected to the inner edge of the horizontal surface, and an inclined surface whose upper edge is connected to the lower edge of the connecting surface. The horizontal surface of the groove 573E extends horizontally from the lower edge of the extrusion 573A in Fig. 2 toward the inside in the radial direction. The inner edge of the radial direction of the horizontal surface of the groove 573E in Fig. 2 is connected to the upper edge of the arc-shaped connecting surface. The connecting surface curves downward in Fig. 2 and toward the outside in the radial direction.

[0052] The lower edge of the arc-shaped connecting surface in Fig. 2 is connected to the upper edge of the inclined surface. The inclined surface of the groove portion 573E extends radially outward from the upper side to the lower side along the axial direction in Fig. 2. That is, the groove portion 573E of this embodiment can be regarded as having a triangular shape with a horizontal base on the upper side and a hypotenuse on the lower side in the cross-sectional view of Fig. 2. In the present disclosure, the shape of the groove is not limited to a triangular shape.

[0053] As shown in FIG. 2 , in this embodiment, the space between the outer circumferential surface of the groove 573E and the inner circumferential surface of the through-hole 562A accommodates resin shavings GD generated at the gate position GP of the output gear 56. In the present disclosure, it is not essential that shavings actually be accommodated in the space between the outer circumferential surface of the groove and the inner circumferential surface of the through-hole. In the present disclosure, it is sufficient that shavings can be accommodated in the space between the outer circumferential surface of the groove and the inner circumferential surface of the through-hole. While FIG. 2 illustrates granular or powdery shavings GD, in reality, shavings may be linear, as will be described later with reference to FIG. 7 . The shavings GD will be described later with reference to FIGS. 6 and 7 .

[0054] (Protrusion portion) As shown in Fig. 3, the protrusion portion 573B of this embodiment has a plurality of protrusions 573C. In the present disclosure, the number of protrusions may be one. The plurality of protrusions 573C extend along the axial direction and are arranged side by side in the circumferential direction. Each of the plurality of protrusions 573C extending along the axial direction is provided on the outer peripheral surface of the output shaft 57 on the other end side of the groove 573E in the axial direction (i.e., the lower side in Fig. 2).

[0055] In this embodiment, each of the protrusions 573C has a triangular cross section. In the present disclosure, the cross-sectional shape of the protrusions is not limited to a triangular shape and may be any shape. Each of the protrusions 573C has an inclined surface 573D at the end on the extrusion portion 573A side (i.e., the upper end in FIG. 2 ). The inclined surface 573D is connected to the inclined surface of the groove portion 573E. The inclined surface 573D extends radially outward as it extends axially downward from the extrusion portion 573A in FIG. 2 .

[0056] In this embodiment, as shown in FIG. 4 , before the output gear 56 and the output shaft 57 are assembled, each of the multiple protrusions 573C is positioned radially outward from the inner circumferential surface of the through hole 562A. The tips of the multiple protrusions 573C are located at the outermost positions in the radial direction. The diameter of an imaginary circle connecting the tips of the multiple protrusions 573C is larger than the diameter of the output gear 56. The imaginary circle is not shown. The diameter of the imaginary circle is smaller than the diameter of the stopper portion 572. The protrusions 573B are formed, for example, by knurling.

[0057] The diameter of the extrusion portion 573A before the output gear 56 and the output shaft 57 are assembled is preferably the same as or slightly smaller than the diameter of the through hole 562A of the output gear 56. In this embodiment, as shown in FIG. 4 (described later), the protrusion portion 573B, which has a diameter larger than the diameter of the through hole 562A, is disposed below the groove portion 573E in FIG. 2. Therefore, when the output gear 56 and the output shaft 57 are assembled, before the protrusion portion 573B abuts against the inner circumferential surface of the through hole 562A, the outer circumferential surface of the extrusion portion 573A slides against the inner circumferential surface of the through hole 562A. After the protrusion portion 573B abuts against the inner circumferential surface of the through hole 562A, the inner circumferential surface of the through hole 562A is pressed by the protrusion portion 573B, thereby slightly enlarging the diameter of the inner circumferential surface of the through hole 562A compared to the state before assembly.

[0058] 2 illustrates through hole 562A that has been slightly enlarged in diameter by contact with protrusion 573B after assembly, and output shaft 57 inserted into through hole 562A. Note that while Fig. 2 illustrates a state in which the outer peripheral surface of extrusion portion 573A of output shaft 57 of the present embodiment is slightly separated from the inner peripheral surface of through hole 562A, this disclosure does not exclude the case in which the outer peripheral surface of the extrusion portion contacts the inner peripheral surface of the through hole.

[0059] In order to allow the protrusion 573B to be positioned at a location away from the upper opening of the through-hole 562A in FIG. 2 and downward, the axial length of the extrusion 573A in this embodiment is set to be at least 1 / 10 of the axial length of the protrusion 573B. It is more preferable that the axial length of the extrusion 573A be at least 1 / 5 of the axial length of the protrusion 573B. It is even more preferable that the axial length of the extrusion 573A be no more than 1 / 2 of the axial length of the protrusion 573B.

[0060] <Operation of the Motor-Operated Valve> Next, the operation of the motor-operated valve 1 will be described. In the motor-operated valve 1, current is passed through the coil of the stator 90, causing the magnet rotor 41 to rotate in one direction. The rotation of the magnet rotor 41 is transmitted to the drive shaft 65 via the planetary gear mechanism 50. The drive shaft 65 moves downward due to the screw feed action between the drive shaft 65 and the guide member 60. The drive shaft 65 pushes the valve disc 70 downward, reducing the opening area of ​​the valve port 14.

[0061] In the motor-operated valve 1, current is passed through the coil of the stator 90 to rotate the magnet rotor 41 in the other direction. The rotation of the magnet rotor 41 is transmitted to the drive shaft 65 via the planetary gear mechanism 50. The drive shaft 65 moves upward due to the screw feed action between the drive shaft 65 and the guide member 60. The valve disc 70 is pushed upward by the valve-opening spring 75, and the opening area of ​​the valve port 14 increases.

[0062] <Assembly Method> Next, the assembly method for assembling the output gear 56 and the output shaft 57 will be described with reference mainly to FIGS. 4 to 7 . The assembly worker first fabricates the output gear 56 by injection molding using a mold in which a gate is located at a position corresponding to the inner circumferential surface of the through hole 562A. The mold is not shown. As shown in FIG. 4 , before the output gear 56 and the output shaft 57 are assembled, resin pieces GX corresponding to the mold gate and runner remain. FIG. 4 illustrates an example of resin pieces GX connected to the left and right inner circumferential surfaces at the center height in the vertical direction inside the through hole 562A. As shown in FIG. 5 , disk-shaped resin pieces GX are formed inside the through hole 562A of the output gear 56 as gate remains. For ease of viewing, the resin pieces GX inside the through hole 562A are shaded in FIG. 5 .

[0063] Next, as shown in FIG. 6 , the assembly worker inserts the extrusion portion 573A of the press-fit end portion 573 into the through-hole 562A while sliding the outer surface of the extrusion portion 573A on the inner surface of the through-hole 562A. The resin piece GX is pushed upward in FIG. 6 by the press-fit end portion 573, resulting in separation from the inner surface of the through-hole 562A. At this time, an adhesion portion GR, which is part of the gate residue, is generated on the inner surface of the through-hole 562A. For convenience, a rectangular adhesion portion GR is illustrated in FIG. 6 , but the shape of the adhesion portion in the present disclosure is not limited to this and may be any shape.

[0064] 6, the adhesion portion GR may be held in a compressed state between the outer peripheral surface of the extrusion portion 573A and the inner peripheral surface of the through hole 562A, or may peel off from the gate position GP. Shavings (e.g., shavings GD in FIG. 2) may be formed when resin pieces GX are separated from the gate position GP due to the press-fitting of the output shaft 57 into the through hole 562A during assembly of the output gear 56 and the output shaft 57. Shavings GD may also be formed when a portion of the inner peripheral surface of the through hole 562A and the adhesion portion GR adhering to the inner peripheral surface are separated from the inner peripheral surface due to the press-fitting.

[0065] Next, the assembly worker presses the protrusion portion 573B into the through hole 562A while forcing the multiple ridges 573C of the protrusion portion 573B of the press-fit end portion 573 into the inner circumferential surface of the through hole 562A. The assembly worker continues the press-fitting until the stopper portion 572 abuts against the bottom portion 562 of the output gear 56. The shavings GD formed by the press-fitting of the multiple ridges 573C are held between the multiple ridges 573C and the inner circumferential surface of the through hole 562A.

[0066] Next, with reference to the cross-sectional view of FIG. 7 , the shavings GD stored in the groove 573E upon press-fitting will be described along with the detailed configuration of the groove 573E. As shown in FIG. 7 , the groove 573E of this embodiment has a groove bottom 58B, an introduction wall 58A, and a return wall 58C. In this embodiment, the groove bottom 58B is located at the innermost position (the right side in FIG. 7 ) in the radial direction of the through hole 562A in a cross-sectional view. The groove bottom 58B has an arc-shaped connecting surface in a cross-sectional view. The groove bottom 58B, the introduction wall 58A, and the return wall 58C form the outer peripheral surface of the groove 573E.

[0067] (Introduction Wall Portion) As shown in FIG. 7 , the introduction wall portion 58A is radially outer (left side in FIG. 7 ) and continues from the lower side to the groove bottom portion 58B in a cross-sectional view. The introduction wall portion 58A introduces shavings GD to the groove bottom portion 58B. In the present disclosure, the introduction wall portion is not required. Furthermore, in the present disclosure, the introduction wall portion may be disposed either above or below in the axial direction. In the present embodiment, the introduction wall portion 58A is an inclined surface configured to approach the radially inner side (right side in FIG. 7 ) as it approaches the groove bottom portion 58B from the side away from the groove bottom portion 58B (lower side in FIG. 7 ) in a cross-sectional view. The inclined surface facilitates the introduction of shavings GD to the groove bottom portion 58B. In the present disclosure, it is not required that the introduction wall portion be an inclined surface. The shape of the introduction wall portion is arbitrary.

[0068] (Return Wall Portion) As shown in FIG. 7, the return wall portion 58C is located on the opposite side (upper side in FIG. 7) from the introduction wall portion 58A across the groove bottom portion 58B in the axial direction (vertical direction in FIG. 7). The return wall portion 58C prevents the stored shavings GD from leaking out of the groove portion 573E. In other words, the shavings GD accumulated in the groove portion 573E are less likely to leak out of the groove portion 573E. In the present disclosure, the return wall portion is not essential. Furthermore, in the present disclosure, the return wall portion may be located either above or below in the axial direction.

[0069] As shown in FIG. 7 , in this embodiment, the return wall 58C has a horizontal surface in a cross-sectional view. That is, the return wall 58C and the wall of the vertical opening edge 59 of the groove 573E adjacent to the return wall 58C above the return wall 58C in FIG. 7 intersect at approximately 90 degrees. By setting the intersection angle within 90 degrees, shavings GD are less likely to move toward the opening edge 59 of the groove 573E. That is, shavings GD are more likely to accumulate inside the groove 573E. In the present disclosure, it is not essential that the intersection angle between the return wall and the opening edge of the groove adjacent to the return wall be within 90 degrees. The intersection angle is arbitrary.

[0070] 7, the present embodiment illustrates a triangular groove 573E having a horizontal base on the upper side as the return wall 58C and a hypotenuse on the lower side as the introduction wall 58A, but the shape of the groove is not limited to a triangular shape in the present disclosure and can be changed as appropriate. For example, even if the cross-sectional shape of the groove is arc-shaped in the present disclosure, the groove may have a groove bottom, an introduction wall, and a return wall.

[0071] In this embodiment, the shavings GD are formed linearly from the inner circumferential surface of the through hole 562A of the output gear 56 by being pushed out along the axial direction of the protrusion 573C that occurs during press-fitting. Specifically, as shown in FIG. 7 , the shavings GD are scraped linearly from the inner circumferential surface of the through hole 562A of the bottom portion 562 of the output gear 56 by the inclined surface 573D of the protrusion 573C. In the present disclosure, it is not essential that the shavings be linear. The shape of the shavings is arbitrary.

[0072] FIG. 7 illustrates an example of the press-fitting direction DP when the output gear 56 is press-fitted from top to bottom onto the output shaft 57. As the press-fitting proceeds, linear shavings GD are introduced into the groove bottom 58B by the introduction wall 58A. As the press-fitting proceeds while the shavings GD are continuously removed, the tip of the shavings GD located on the opposite side of the lower cut-out portion in FIG. 7 bends from the groove bottom 58B toward the return wall 58C. The tip of the shavings GD extends along the return wall 58C and strikes the inner circumferential surface of the through hole 562A. After the tip of the shavings GD strikes the inner circumferential surface of the through hole 562A, the tip of the shavings GD bends toward the introduction wall 58A (the lower side in FIG. 7). Therefore, the linear shavings GD are rounded inside the groove 573E. FIG. 7 illustrates a portion of the trajectory DG of the movement of the tip of the shavings GD.

[0073] The length of the rounded linear shavings GD is not limited to the length of the shavings GD illustrated in FIG. 7 and may vary as appropriate. The phrase "press-fitting proceeds while shavings GD are continuously removed" encompasses both cases where only one shavings GD is formed and cases where two or more shavings are formed. Furthermore, in this embodiment, the volume of the groove 573E is designed to be equal to or greater than the volume of the shavings GD generated. This prevents the shavings GD from leaking axially between the outer circumferential surface of the groove 573E and the inner circumferential surface of the through-hole 562A. In the present disclosure, the volume of the groove is arbitrary.

[0074] The above series of steps constitutes the method for assembling the output gear 56 and the output shaft 57 in the motor-operated valve 1 according to this embodiment. Furthermore, as shown in Fig. 3, the output gear 56 and the output shaft 57 can be assembled integrally.

[0075] (Operation and Effect) In the motor-operated valve 1 according to this embodiment, a groove 573E is formed in the output shaft 57, extending circumferentially toward the other end of the output shaft 57 in the axial direction beyond the extrusion portion 573A. The diameter of the output shaft 57 at the position where the groove 573E is formed is smaller than the diameter of the extrusion portion 573A. Therefore, even if resin shavings GD are generated when the extrusion portion 573A pushes out resin pieces GX from the gate formed inside the through hole 562A of the output gear 56 during assembly of the output shaft 57 and the output gear 56, the shavings GD can be contained between the outer circumferential surface of the groove 573E of the output shaft 57 and the inner circumferential surface of the through hole 562A. This reduces the burden of removing shavings GD generated during assembly of the resin output gear 56 and the output shaft 57.

[0076] In this embodiment, multiple ridges 573C extending along the axial direction are provided on the outer peripheral surface of the output shaft 57 lower in the axial direction than the grooves 573E in FIG. 2 , and positioned radially outward from the inner peripheral surface of the through hole 562A. Therefore, when one end of the output shaft 57 is press-fitted into the through hole 562A, the multiple ridges 573C bite into the inner peripheral surface of the through hole 562A. This biting cuts off the inner peripheral surface of the through hole 562A and the adhesion portion GR adhering to the inner peripheral surface, forming shavings GD. The shavings GD can be held between the ridges and the inner peripheral surface of the through hole 562A.

[0077] Therefore, even if the amount of shavings formed exceeds the capacity of the groove portion 573E, the shavings GD can be held between the plurality of ridges 573C and the inner circumferential surface of the through hole 562A. As a result, compared to when the shavings GD are held by the groove portion 573E alone, the shavings GD can be prevented from moving axially toward the extrusion portion 573A relative to the groove portion 573E.

[0078] In this embodiment, the axial length of the extrusion portion 573A is at least 1 / 10 of the axial length of the protrusion portion 573B. This allows the protrusion portion 573B to be reliably positioned in a recessed location below the upper opening of the through-hole 562A in FIG. 2. As a result, it is possible to reliably prevent the shavings GD from spilling out of the through-hole 562A.

[0079] Further, at the end of each of the plurality of protrusions 573C on the extrusion portion 573A side, an inclined surface 573D is formed, which is connected to the outer peripheral surface of the extrusion portion 573A and which extends radially outward as it moves away from the extrusion portion 573A along the axial direction. The inclined surface 573D causes the diameter of the protrusion portion 573B to gradually increase as the press-fitting progresses, thereby enabling the press-fit end portion 573 to be smoothly press-fitted into the through-hole 562A.

[0080] In the present embodiment, the shavings GD are accommodated between the outer peripheral surface of the groove portion 573E and the inner peripheral surface of the through hole 562A. Therefore, the shavings GD accommodated in the groove portion 573E mix with, for example, the fluid refrigerating machine oil, making it easier to retain the refrigerating machine oil inside the groove portion 573E.

[0081] In addition, in this embodiment, the groove 573E is provided with an introduction wall 58A that continues from the radial outside to the groove bottom 58B and introduces the shavings GD into the groove bottom 58B, making it easy to introduce the shavings GD into the groove bottom 58B. In addition, the groove 573E is provided with a return wall 58C that prevents the shavings GD from leaking out of the groove 573E, making it easy to keep the shavings GD inside the groove 573E.

[0082] In addition, in this embodiment, the shavings GD formed in a linear shape by the ridges 573C can be accommodated inside the grooves 573E.

[0083] (Other Aspects of the Groove Portion) Next, other aspects of the groove portion of the present disclosure will be described with reference to Figures 8A to 8E. In this embodiment, as shown in the cross-sectional view of Figure 2, a triangular groove portion 573E having a horizontal base on the upper side and a hypotenuse on the lower side is illustrated, but in this disclosure, the shape of the groove portion is not limited to a triangular shape and can be modified as appropriate. Note that in the motor-operated valves having the groove portions illustrated in Figures 8A to 8E, the configurations of the other components, excluding the groove portion, are the same as the components with the same names in the motor-operated valve 1 according to this embodiment, and therefore redundant description will be omitted.

[0084] As shown in Fig. 8A, the shape of the groove 573F may be a triangle having a horizontal base on the lower side and a hypotenuse on the upper side in a cross-sectional view. In the motor-operated valve illustrated in Fig. 8A, a gate position GP where a resin piece of the gate is formed on the inner circumferential surface of the through-hole 562A is located closer to one end of the groove 573F in the axial direction of the output shaft 57 (i.e., the upper side in Fig. 8A). The gate position GP faces the extrusion portion 573A.

[0085] The inclined surface of groove 573F is inclined so that its radial depth increases from one end (i.e., the upper side in FIG. 8A ) to the other end (i.e., the lower side in FIG. 8A ) in the axial direction in a cross-sectional view. The lower edge of the inclined surface communicates with the upper edge of the curved connecting surface, and the lower edge of the connecting surface communicates with the inner edge of a horizontal surface that extends horizontally outward in the radial direction. The outer edge of the horizontal surface of groove 573F in FIG. 8A communicates with the upper edge of inclined surface 573D.

[0086] 8A, similarly to the present embodiment, it is possible to accommodate resin shavings GD of the output gear 56 between the outer peripheral surface of the groove 573F of the output shaft 57 and the inner peripheral surface of the through hole 562A. This reduces the burden of the work of removing shavings GD generated by assembling the resin output gear 56 and the output shaft 57.

[0087] 8A, when the output gear 56 is positioned above the output shaft 57 with the axial direction aligned vertically, the groove 573F is positioned below the gate position GP. Therefore, even if shavings GD generated from the gate position GP fall, they can be easily collected by the groove 573F. Other effects of the motor-operated valve having the groove 573F in FIG. 8A are the same as those of the present embodiment.

[0088] As shown in Fig. 8B, the shape of groove portion 573G may be trapezoidal in cross section. Specifically, groove portion 573G in Fig. 8B has a horizontal surface whose outer edge is connected to the lower edge of extrusion portion 573A, an arc-shaped first connecting surface whose upper edge is connected to the inner edge of the horizontal surface, a vertical surface whose upper edge is connected to the lower edge of the first connecting surface, an arc-shaped second connecting surface whose upper edge is connected to the lower edge of the vertical surface, and an inclined surface whose inner edge is connected to the lower edge of the second connecting surface. The outer edge of the inclined surface of groove portion 573G in Fig. 8B is connected to the upper edge of inclined surface 573D.

[0089] 8B, similarly to the present embodiment, it is possible to accommodate resin shavings GD of the output gear 56 between the outer peripheral surface of the groove 573G of the output shaft 57 and the inner peripheral surface of the through hole 562A. This reduces the burden of the work of removing shavings GD generated by assembling the resin output gear 56 and the output shaft 57.

[0090] As shown in Fig. 8C , groove 573H may have a trapezoidal shape that is vertically symmetrical to groove 573G in Fig. 8B in a cross-sectional view. Specifically, groove 573H in Fig. 8C has an inclined surface whose upper edge communicates with the lower edge of extrusion portion 573A, an arc-shaped first connecting surface whose upper edge communicates with the inner edge of the inclined surface, a vertical surface whose upper edge communicates with the lower edge of the first connecting surface, an arc-shaped second connecting surface whose upper edge communicates with the lower edge of the vertical surface, and a horizontal surface whose inner edge communicates with the lower edge of the second connecting surface. The outer edge of the horizontal surface of groove 573H in Fig. 8C communicates with the upper edge of inclined surface 573D.

[0091] 8C , similarly to the present embodiment, it is possible to accommodate resin shavings GD of the output gear 56 between the outer peripheral surface of the groove 573H of the output shaft 57 and the inner peripheral surface of the through hole 562A. This reduces the burden of the work of removing shavings GD generated by assembling the resin output gear 56 and the output shaft 57.

[0092] As shown in FIG. 8D , groove 573I may have a rectangular cross-sectional shape. Specifically, groove 573I in FIG. 8D includes a first horizontal surface whose outer edge is connected to the lower edge of extrusion portion 573A, an arc-shaped first connecting surface whose upper edge is connected to the inner edge of the first horizontal surface, a vertical surface whose upper edge is connected to the lower edge of the first connecting surface, an arc-shaped second connecting surface whose upper edge is connected to the lower edge of the vertical surface, and a second horizontal surface whose inner edge is connected to the lower edge of the second connecting surface. The outer edge of the second horizontal surface below groove 573I in FIG. 8D is connected to the upper edge of inclined surface 573D.

[0093] 8D, similarly to the present embodiment, it is possible to accommodate resin shavings GD of the output gear 56 between the outer peripheral surface of the groove 573I of the output shaft 57 and the inner peripheral surface of the through hole 562A. This reduces the burden of the work of removing shavings GD generated by assembling the resin output gear 56 and the output shaft 57.

[0094] 8E, the shape of groove 573J may be an arc shape as a whole in a cross-sectional view. Specifically, groove 573J in Fig. 8E has a semicircular curved surface whose upper edge communicates with the lower edge of extrusion portion 573A and whose lower edge communicates with the upper edge of inclined surface 573D.

[0095] 8E, similarly to the present embodiment, it is possible to accommodate resin shavings GD of the output gear 56 between the outer peripheral surface of the groove 573J of the output shaft 57 and the inner peripheral surface of the through hole 562A. This reduces the burden of the work of removing shavings GD generated by assembling the resin output gear 56 and the output shaft 57.

[0096] Furthermore, according to the groove portion 573J in FIG. 8E, since the groove portion 573J has an arc shape in cross section, it is easier to process and form the groove portion 573J than when forming a groove portion that has a triangular or rectangular shape in cross section, for example.

[0097] Although the present disclosure has been described based on the above disclosed embodiments, the descriptions and drawings that form part of this disclosure should not be understood to limit the present disclosure. For example, the present disclosure can be configured by partially combining the configurations illustrated in the attached drawings. The present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specific matters in the scope of the claims that are appropriate from the above description.

[0098] The disclosure of Japanese Patent Application No. 2024-150139, filed on August 30, 2024, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A gear-type reduction mechanism that has an output shaft and a resin output gear with a bottom formed with a through hole into which one end of the output shaft fits, and that reduces the rotation of a motor before outputting it, wherein the output shaft has an extrusion portion provided at one end that extrudes a resin piece of a gate formed inside the through hole of the output gear, and the gear-type reduction mechanism has a groove portion formed circumferentially on the other end side of the extrusion portion in the axial direction of the output shaft; and a valve body that controls the opening degree of a valve by the rotation of the output of the gear-type reduction mechanism.

2. The motor-operated valve according to claim 1, wherein a protrusion extending along the axial direction is provided on the outer peripheral surface of the output shaft closer to the other end than the groove in the axial direction, and positioned radially outward than the inner peripheral surface of the through hole.

3. An electric valve as claimed in claim 1 or 2, wherein the gate position where the resin piece is formed on the inner peripheral surface of the through hole is located closer to the one end than the groove portion in the axial direction of the output shaft, and the radial depth of the groove portion becomes deeper from the one end side to the other end side in the axial direction when viewed in cross section.

4. The motor-operated valve according to any one of claims 1 to 3, wherein the groove portion has an arc shape in cross section.

5. The motor-operated valve according to any one of claims 1 to 4, wherein shavings are contained between the outer peripheral surface of the groove portion and the inner peripheral surface of the through hole.

6. An electric valve as claimed in any one of claims 1 to 5, wherein the groove portion has, in a cross-sectional view, a groove bottom portion located at the innermost radial position of the through hole, an introduction wall portion that continues from the outer side in the radial direction to the groove bottom portion and introduces shavings to the groove bottom portion, and a return wall portion that is located on the opposite side of the introduction wall portion across the groove bottom portion in the axial direction and prevents the accommodated shavings from leaking out of the groove portion.

7. An electric valve as claimed in any one of claims 1 to 6, wherein a ridge extending along the axial direction is provided on the outer peripheral surface of the output shaft closer to the other end than the groove portion in the axial direction, and positioned radially outward than the inner peripheral surface of the through hole, and shavings contained between the outer peripheral surface of the groove portion and the inner peripheral surface of the through hole are extruded along the axial direction by the ridge to form a line from the inner peripheral surface of the through hole of the output gear.

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