Valve unit and valve device

Abstract

To provide a valve unit and valve device that can suppress adverse effects caused by wear particles. [Solution] The valve unit 7 includes a rotor 51, a valve stem holder 52, a guide bush 53, and a valve body 40. The inner circumferential surface of the valve stem holder 52 is provided with a female thread 52t and a holder sliding surface 52s. The outer circumferential surface of the guide bush 53 is provided with a male thread 53t that is screwed into the female thread 52t and a guide sliding surface 53s that contacts the holder sliding surface 52s. The male thread 53t is located at the upper end of the guide bush 53. The valve stem holder 52 has a lateral hole 52h that connects the space 52v in which the male thread 53t is located in the valve stem holder 52 to the outer space of the valve stem holder 52.

Description

Technical Field

[0001] The present invention relates to a valve unit and a valve device having the valve unit.

Background Art

[0002] Patent Document 1 discloses an example of a conventional valve device. The valve device includes a valve body having a valve port, a magnet rotor, a cylindrical valve shaft holder fixed to the magnet rotor, a cylindrical guide bush fixed to the valve body, and a cylindrical valve body inserted through the guide bush and moving together with the valve shaft holder. The valve body faces the valve port in the axial direction. An internal thread is provided on the inner peripheral surface of the valve shaft holder. An external thread that engages with the internal thread is provided on the outer peripheral surface of the guide bush. The valve shaft holder rotates together with the magnet rotor and moves in the axial direction by a feed screw action. The valve body moves together with the valve shaft holder, and the opening degree of the valve port changes.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a valve system, increasing the diameter of the valve port necessitates increasing the diameter of the valve body. Increasing the diameter of the valve body can reduce the thickness of the guide bush, potentially lowering its rigidity. By providing a male thread at the upper end of the guide bush, the diameter of the portion of the valve body located at the upper end of the guide bush can be made smaller than the diameter of the portion closer to the valve port. This allows for securing a valve body diameter suitable for the valve port while suppressing a reduction in the thickness of the guide bush. However, because the upper end of the guide bush is surrounded by the valve stem holder, wear particles from the female and male threads can accumulate between the guide bush and the valve stem holder, potentially causing adverse effects on the valve system, such as difficulty in rotating the valve stem holder.

[0005] Therefore, the present invention aims to provide a valve unit and valve device that can suppress adverse effects caused by wear particles. [Means for solving the problem]

[0006] To achieve the above objective, a valve unit according to one aspect of the present invention is a valve unit comprising a magnet rotor, a cylindrical holder fixed to the magnet rotor, a cylindrical guide disposed inside the holder, and a cylindrical valve body inserted through the guide and moving together with the holder, wherein the inner circumferential surface of the holder is provided with a female screw and a holder sliding surface, the outer circumferential surface of the guide is provided with a male screw that is screwed into the female screw and a guide sliding surface that contacts the holder sliding surface, the male screw is disposed at the end of the guide, and the holder or the guide has a passage connecting the space in the holder where the male screw is disposed with the space outside the holder.

[0007] In the present invention, it is preferable that the passage is a hole that penetrates the holder radially.

[0008] In the present invention, it is preferable that the passage is a groove provided on the holder sliding surface or the guide sliding surface.

[0009] To achieve the above objective, a valve device according to another aspect of the present invention comprises a valve unit, a flow path unit to which the valve unit is attached, and a stator unit having a stator that, together with the magnet rotor, constitutes a motor. [Effects of the Invention]

[0010] According to the present invention, the inner circumferential surface of the holder, which moves together with the valve body, is provided with a female thread and a holder sliding surface. The outer circumferential surface of the guide is provided with a male thread that is screwed into the female thread and a guide sliding surface that contacts the holder sliding surface. The male thread is located at the end of the guide. The holder or guide has a passage that connects the space in the holder where the male thread is located to the space outside the holder. In this way, wear particles from the female thread and male thread can be discharged from the space in the holder through the passage. Therefore, adverse effects from wear particles can be suppressed. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view of a valve device according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view of the flow path unit and valve unit of the valve device. [Figure 3] This is a cross-sectional view of the valve unit after disassembly. [Figure 4] This is a cross-sectional view of the valve unit. [Figure 5] This is a cross-sectional view showing a first modified example of the valve unit in Figure 4. [Figure 6] Figure 5 is a cross-sectional view of the valve stem holder of the valve unit. [Figure 7] This is a cross-sectional view showing a second modified example of the valve unit in Figure 4. [Figure 8] Figure 7 is a cross-sectional view of the valve stem holder of the valve unit. [Figure 9] Figure 8 shows a cross-sectional view along the line IX-IX. [Modes for carrying out the invention]

[0012] Hereinafter, a valve device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4.

[0013] Each figure shows a valve device according to an embodiment of the present invention. The valve device 1 according to this embodiment is incorporated in, for example, a refrigeration cycle system and used as a flow control valve for controlling the flow rate of a refrigerant.

[0014] The valve device 1 has a flow path unit 5, a valve unit 7, and a stator unit 9.

[0015] The flow path unit 5 has a main body portion 10 and a valve seat 17.

[0016] The main body portion 10 is made of, for example, an aluminum alloy. The main body portion 10 has a first upper surface 10a and a second upper surface 10b which are outer surfaces. The first upper surface 10a and the second upper surface 10b are parallel planes. The second upper surface 10b is below the first upper surface 10a. The first upper surface 10a is a first plane, and the second upper surface 10b is a second plane.

[0017] The main body portion 10 has a mounting hole 11, and flow paths 13 and 14. The mounting hole 11 is a circular hole and extends downward from the second upper surface 10b. The opening 11o of the mounting hole 11 is arranged on the second upper surface 10b. A female thread 11t is provided on the inner peripheral surface of the mounting hole 11. The lower part of the mounting hole 11 is a valve chamber 12.

[0018] The main body portion 10 has a wall portion 16. The wall portion 16 has an annular shape. The wall portion 16 projects upward from the second upper surface 10b. The wall portion 16 surrounds the mounting hole 11. The upper end (tip) of the wall portion 16 and the first upper surface 10a are included in one virtual plane.

[0019] The valve seat 17 is made of, for example, stainless steel. The valve seat 17 has a cylindrical shape and is disposed at the lower part of the valve chamber 12. The valve seat 17 may be integrally formed with the main body portion 10. A valve port 18 is provided inside the valve seat 17. The flow path 13 communicates with the valve chamber 12 through the valve port 18. The flow path 14 extends horizontally from the valve chamber 12.

[0020] The valve unit 7 has a connecting member 20, a cam 30, a valve body 40, and a drive mechanism 50.

[0021] The connecting member 20 integrally has a peripheral wall portion 21, a bottom wall portion 22, and a flange portion 23.

[0022] The peripheral wall portion 21 has a cylindrical shape. A receiving surface 21c is provided on the inner peripheral surface of the peripheral wall portion 21. The receiving surface 21c is an annular plane facing upward. An external thread 21t is provided on the outer peripheral surface of the peripheral wall portion 21. The external thread 21t is screwed into the internal thread 11t of the mounting hole 11 of the main body portion 10.

[0023] The bottom wall portion 22 has a disk shape. The outer peripheral edge of the bottom wall portion 22 is connected to the lower end (one end) of the peripheral wall portion 21. The bottom wall portion 22 has a shaft hole 24 which is a through hole.

[0024] The flange portion 23 has an annular plate shape. The inner peripheral edge of the flange portion 23 is connected to the upper end (the other end) of the peripheral wall portion 21. The flange portion 23 is orthogonal to the peripheral wall portion 21. The outer diameter of the flange portion 23 is larger than the outer diameter of the wall portion 16.

[0025] In the manufacturing process of the connecting member 20, by pressing the sheet metal, the peripheral wall portion 21, the bottom wall portion 22, and the flange portion 23 are integrally formed, and the receiving surface 21c and the shaft hole 24 are formed. Then, an external thread 21t is formed on the peripheral wall portion 21, and the connecting member 20 is completed. The connecting member 20 is made of, for example, iron or stainless steel.

[0026] The connecting member 20 is positioned in the mounting hole 11 of the main body 10. Specifically, the peripheral wall portion 21 and the bottom wall portion 22 are inserted into the mounting hole 11, and the male thread 21t of the peripheral wall portion 21 is screwed into the female thread 11t of the main body 10. As the male thread 21t is screwed into the female thread 11t, the connecting member 20 moves downward. When the lower surface of the flange portion 23 comes into contact with the upper end of the wall portion 16 of the flow path unit 5, the downward movement of the connecting member 20 is restricted, and the male thread 21t and the female thread 11t are tightened. The wall portion 16 is a positioning portion for the connecting member 20.

[0027] The can 30 is made of, for example, stainless steel. The can 30 has a cylindrical shape. The can 30 is open at the bottom and closed at the top. The bottom end of the can 30 is joined to the outer edge of the flange portion 23. The can 30 is a case.

[0028] The valve body 40 has a shaft portion 41 and a valve portion 45. The shaft portion 41 has a cylindrical shape. A spring receiving surface 46 is provided on the outer circumferential surface of the shaft portion 41. The spring receiving surface 46 is an annular plane facing upward. The valve portion 45 has a frustoconical shape. The valve portion 45 is coaxially connected to the lower end of the shaft portion 41. The diameter of the lower part 41a of the shaft portion 41 is greater than the diameter of the central part 41b of the shaft portion 41. The diameter of the central part 41b of the shaft portion 41 is greater than the diameter of the upper part 41c of the shaft portion 41. The diameter of the lower part 41a is the same as the diameter of the axial hole 24 of the connecting member 20. The lower part 41a is inserted through the axial hole 24 of the connecting member 20. The connecting member 20 supports the shaft portion 41 so that it can move in the vertical direction. The valve portion 45 faces the valve seat 17 in the vertical direction. The tip of the valve portion 45 is positioned at the valve opening 18. When the valve portion 45 contacts the valve seat 17, the valve opening 18 closes. When the valve portion 45 moves away from the valve seat 17, the valve opening 18 opens. In each figure, the valve body 40 is shown in a front view.

[0029] The drive mechanism 50 moves the valve body 40 in the vertical direction. The movement of the valve body 40 changes the opening degree of the valve port 18. The drive mechanism 50 includes a rotor 51, a valve stem holder 52, a guide bush 53, a connecting plate 55, a retaining member 56, and a valve closing spring 57.

[0030] The rotor 51 has a cylindrical shape. The rotor 51 is positioned inside the can 30. The rotor 51 has multiple magnetic poles. The multiple magnetic poles are arranged on the outer surface of the rotor 51. The rotor 51 is a magnetic rotor.

[0031] The valve stem holder 52 is made of, for example, brass. The valve stem holder 52 has a cylindrical shape. The lower end of the valve stem holder 52 is open. The valve stem holder 52 integrally has a circumferential wall portion 52a and an upper wall portion 52b. The upper wall portion 52b is connected to the upper end of the circumferential wall portion 52a. The inner circumferential surface of the circumferential wall portion 52a is provided with a holder sliding surface 52s and a female screw 52t. The inner diameter of the female screw 52t is smaller than the diameter of the holder sliding surface 52s. The female screw 52t is located above the holder sliding surface 52s. The valve stem holder 52 also has a lateral hole 52h. The lateral hole 52h is provided at the upper end of the holder sliding surface 52s. The valve stem holder 52 is a holder. The lateral hole 52h is a passage.

[0032] The valve stem holder 52 is fixed to the rotor 51 via an annular connecting plate 55. The valve stem holder 52 rotates together with the rotor 51. The upper part 41c of the shaft portion 41 of the valve body 40 is inserted through a hole provided in the upper wall portion 52b. A retaining member 56 is fixed to the upper part 41c. A valve closing spring 57 is positioned between the upper wall portion 52b and the spring receiving surface 46 of the valve body 40. The valve closing spring 57 is a coil spring that pushes the valve body 40 toward the valve seat 17. A movable stopper 52c is provided on the valve stem holder 52.

[0033] The guide bush 53 is made of, for example, brass or stainless steel. The guide bush 53 integrally comprises a base 53a and a support portion 53b. The base 53a and the support portion 53b have a cylindrical shape. The guide bush 53 is fixed to the main body 10 via a connecting member 20. The guide bush 53 is a guide.

[0034] The base portion 53a is press-fitted into the peripheral wall portion 21 of the connecting member 20, and the lower end surface of the base portion 53a abuts against the receiving surface 21c of the peripheral wall portion 21.

[0035] The support portion 53b is connected to the upper end of the base portion 53a. The outer circumferential surface of the support portion 53b is provided with a guide sliding surface 53s and a male screw 53t. The outer diameter of the male screw 53t is smaller than the diameter of the guide sliding surface 53s. The male screw 53t is located at the upper end of the support portion 53b (the end of the guide bush 53). The male screw 53t is located above the guide sliding surface 53s. The male screw 53t and the guide sliding surface 53s are arranged in this order from the upper end of the support portion 53b. The male screw 53t is screwed into the female screw 52t, and the outer diameter of the portion of the support portion 53b where the guide sliding surface 53s is provided is the same as the inner diameter of the portion of the circumferential wall portion 52a of the valve stem holder 52 where the holder sliding surface 52s is provided. The guide sliding surface 53s is in contact with the holder sliding surface 52s around its entire circumference.

[0036] The shaft portion 41 of the valve body 40 is positioned inside the guide bush 53. The inner diameter of the upper end of the support portion 53b is the same as the diameter of the central portion 41b of the shaft portion 41. The guide bush 53 supports the shaft portion 41 so that it can move in the vertical direction. A fixing stopper 53c is provided on the guide bush 53. The guide bush 53 is fixed to the main body portion 10.

[0037] The stator unit 9 is attached to the valve unit 7. The stator unit 9 includes a stator 60 and a housing 70.

[0038] The stator 60 has a cylindrical shape. A can 30 is positioned inside the stator 60. The stator 60 has multiple coils and multiple pole teeth. The multiple pole teeth face the outer surface of the rotor 51 with the can 30 in between. By supplying drive current to the multiple coils, the multiple pole teeth are magnetized, and the rotor 51 rotates. The rotor 51 and stator 60 constitute a stepping motor 66. Note that the rotor 51 and stator 60 may constitute a motor of a different type than a stepping motor.

[0039] As the rotor 51 rotates in the closing direction, the screw action between the female thread 52t of the valve stem holder 52 and the male thread 53t of the guide bush 53 causes the rotor 51 and the valve stem holder 52 to move downward. The valve body 40 moves downward along with the valve stem holder 52, and the opening of the valve port 18 decreases. When the valve stem holder 52 reaches its lower limit position, the movable stopper 52c abuts against the fixed stopper 53c, restricting the rotation of the rotor 51 and the valve stem holder 52 in the closing direction. At this time, the lateral hole 52h of the valve stem holder 52 faces radially with the lower end of the male thread 53t of the guide bush 53. The lateral hole 52h connects the space 52v where the male thread 53t of the valve stem holder 52 is located to the inner space 30v of the can 30 (i.e., the outer space of the valve stem holder 52).

[0040] As the rotor 51 rotates in the opening direction, the rotor 51 and the valve stem holder 52 move upward due to the feed screw action between the female thread 52t of the valve stem holder 52 and the male thread 53t of the guide bush 53. The valve body 40 moves upward along with the valve stem holder 52, and the opening of the valve port 18 increases. The lateral hole 52h always faces the male thread 53t radially, even when the valve stem holder 52 moves vertically.

[0041] The housing 70 is made of synthetic resin. The housing 70 houses the stator 60. The housing 70 integrally has a peripheral wall 71 and an upper wall 72. The peripheral wall 71 has a cylindrical shape. The upper wall 72 has a dome shape and is connected to the upper end of the peripheral wall 71. The stator 60 is embedded in the inner circumferential surface of the peripheral wall 71. The inner circumferential surface of the peripheral wall 71 and the inner circumferential surface of the stator 60 are connected. The inner circumferential surface of the stator 60, the inner circumferential surface of the peripheral wall 71 and the inner surface of the upper wall 72 form a housing space 75. The can 30 is placed in the housing space 75, and the lower end of the peripheral wall 71 is in contact with the second upper surface 10b of the main body 10.

[0042] The valve device 1 includes a first sealing member 81 and a second sealing member 82. The first sealing member 81 and the second sealing member 82 are made of an elastic material such as rubber.

[0043] The first sealing member 81 has an annular shape. The first sealing member 81 surrounds the wall portion 16 of the main body portion 10. The first sealing member 81 is sandwiched between the outer circumferential surface of the wall portion 16 and the inner circumferential surface of the peripheral wall 71 of the housing 70, and is compressed radially. The first sealing member 81 seals the space between the wall portion 16 and the peripheral wall 71.

[0044] The second sealing member 82 has an annular shape. The second sealing member 82 is positioned inside the wall portion 16 of the main body portion 10 and surrounds the mounting hole 11. The second sealing member 82 is sandwiched between the main body portion 10 and the flange portion 23 of the connecting member 20 and is compressed in the vertical direction. The second sealing member 82 seals the space between the main body portion 10 and the flange portion 23.

[0045] In the valve device 1, the mounting hole 11, wall portion 16, valve seat 17, connecting member 20, can 30, valve body 40, rotor 51, valve stem holder 52 (circumferential wall portion 52a, upper wall portion 52b), guide bush 53 (base portion 53a, support portion 53b), stator 60, housing 70, first sealing member 81, and second sealing member 82 each have their central axes coincide with the axis L.

[0046] As described above, the valve device 1 includes a flow path unit 5, a valve unit 7, and a stator unit 9. The valve unit 7 includes a rotor 51, a cylindrical valve stem holder 52 fixed to the rotor 51, a cylindrical guide bush 53 positioned inside the valve stem holder 52, and a cylindrical valve body 40 inserted through the guide bush 53 and moving together with the valve stem holder 52. The inner circumferential surface of the valve stem holder 52 is provided with a female thread 52t and a holder sliding surface 52s. The outer circumferential surface of the guide bush 53 is provided with a male thread 53t that is screwed into the female thread 52t and a guide sliding surface 53s that contacts the holder sliding surface 52s. The male thread 53t is positioned at the upper end of the guide bush 53. The valve stem holder 52 has a lateral hole 52h that connects the space 52v in the valve stem holder 52 where the male thread 53t is positioned with the inner space 30v of the can 30. In this way, wear particles from the female thread 52t and male thread 53t can be discharged from the space 52v of the valve stem holder 52 through the lateral hole 52h. Therefore, the valve unit 7 can be prevented from being adversely affected by wear particles.

[0047] Furthermore, the lateral hole 52h is a hole that penetrates radially through the peripheral wall portion 52a of the valve stem holder 52. In this way, wear particles from the female thread 52t and male thread 53t can be discharged from the space 52v of the valve stem holder 52 with a relatively simple configuration.

[0048] Next, a modified example of the valve unit 7 will be described with reference to Figures 5 to 9. In Figures 5 to 9, components that are the same as (or substantially the same as) the valve unit 7 are denoted by the same reference numerals.

[0049] Figure 5 shows a cross-sectional view of valve unit 7A, which is a first modified example of valve unit 7, and Figure 6 shows a cross-sectional view of the valve shaft holder 52A of valve unit 7A. Valve unit 7A has the same configuration as valve unit 7, except that it has a valve shaft holder 52A in which a helical groove 52j is provided on the holder sliding surface 52s, instead of a valve shaft holder 52 which has a lateral hole 52h. The helical groove 52j connects the space 52v in which the male screw 53t of the valve shaft holder 52A is located to the inner space 30v of the can 30 (the outer space of the valve shaft holder 52A). Instead of the helical groove 52j, a helical groove may be provided on the guide sliding surface 53s.

[0050] Figure 7 shows a cross-sectional view of valve unit 7B, a second modified example of valve unit 7, and Figure 8 shows a cross-sectional view of the valve shaft holder 52B of valve unit 7B. Figure 9 is a cross-sectional view taken along line IX-IX in Figure 8. Valve unit 7B has the same configuration as valve unit 7, except that it has a valve shaft holder 52B in which a plurality of straight grooves 52k are provided on the holder sliding surface 52s, instead of a valve shaft holder 52 having a lateral hole 52h. The straight grooves 52k extend in the vertical direction. The straight grooves 52k connect the space 52v where the male screw 53t is located in the valve shaft holder 52B and the inner space 30v of the can 30 (the outer space of the valve shaft holder 52B). Instead of the straight grooves 52k, straight grooves may be provided on the guide sliding surface 53s. Only one straight groove 52k may be provided on the holder sliding surface 52s.

[0051] Valve units 7A and 7B produce the same effect as valve unit 7.

[0052] The valve device 1 described above had a flow path unit 5 having a valve seat 17 that faces the valve body 40 in the vertical direction, but the present invention is not limited to this configuration. For example, the valve device 1 may have a bottom wall portion 22 of the connecting member 20 having a valve opening which is a through hole, and a valve seat that surrounds the valve opening and faces the valve body 40 in the vertical direction.

[0053] In this specification, terms indicating shapes such as "cylinder" and "column" are also used to refer to members or parts of members that substantially have the shape of those terms. For example, "cylindrical member" includes both cylindrical members and substantially cylindrical members. Furthermore, in this specification, the term "same" may include both strictly identical and substantially identical items.

[0054] Although embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, deletions, design modifications, and combinations of features of the embodiments, as appropriate by those skilled in the art, are also included within the scope of the present invention, as long as they do not contradict the spirit of the invention. [Explanation of Symbols]

[0055] 1… Valve device 5...Flow path unit, 10...Main body, 11...Mounting hole, 17...Valve seat, 18...Valve opening 7, 7A, 7B... Valve unit, 20... Connecting member, 30... Can 40... Valve body, 50... Drive mechanism, 51... Rotor 52, 52A, 52B... Valve shaft holder, 52s... Holder sliding surface, 52t... Female thread, 52v...Space, 52h...Horizontal hole, 52j...Spiral groove, 52k...Straight groove, 53... Guide bush, 53s... Guide sliding surface, 53t... Male thread, 9... Stator unit, 60... Stator, 70... Housing L…Axis line

Claims

1. A valve unit comprising a magnetic rotor, a cylindrical holder fixed to the magnetic rotor, a cylindrical guide positioned inside the holder, and a cylindrical valve body inserted through the guide and moving together with the holder, The inner circumferential surface of the holder is provided with an internal screw and a holder sliding surface. The outer circumferential surface of the guide is provided with a male thread that is screwed into the female thread and a guide sliding surface that contacts the holder sliding surface. The male screw is positioned at the end of the guide, A valve unit characterized in that the holder or the guide has a passage connecting the space in the holder where the male screw is located and the space outside the holder.

2. The valve unit according to claim 1, wherein the passage is a hole that penetrates the holder radially.

3. The valve unit according to claim 1, wherein the passage is a groove provided on the holder sliding surface or the guide sliding surface.

4. A valve device comprising: a valve unit according to claim 1; a flow path unit to which the valve unit is attached; and a stator unit having a stator that, together with the magnet rotor, constitutes a motor.

Images