Motorised valve

Abstract

Provided is an electric valve that can be miniaturized with a simple structure and can suppress pressure loss and the like. The electric valve has a motor, a driven portion that has a flange portion having a through opening and a shield wall and is rotated by the motor, and a housing that has a fluid inflow path and a fluid discharge path and houses the driven portion, the through opening or the shield wall being disposed between the fluid inflow path and the fluid discharge path according to a rotational position of the driven portion.

Description

Technical Field

[0001] This invention relates to an electric valve. Background Technology

[0002] Traditionally, electric valves, for example, have been used as devices for opening and closing fluid flow paths and controlling flow rate, located midway through a fluid piping system. In such electric valves, the valve core is driven by a drive source such as a stepper motor mounted on the valve body in order to accurately control the flow rate.

[0003] Patent Document 1 discloses an electric valve that allows the flow of fluids such as refrigerant between a first port and a second port by driving the valve core away from the valve seat via a stepper motor, and prevents the flow of fluids between the first port and the second port by causing the valve core to sit on the valve seat.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-173877

[0007] The technical problem that the invention aims to solve

[0008] In the electric valve of Patent Document 1, a conversion mechanism is used to convert the rotary motion of the stepper motor into the linear motion of the valve core, and this conversion mechanism uses a thread. Therefore, in addition to the complex structure, the sliding resistance of the thread is relatively large, which requires an increase in the capacity of the stepper motor, resulting in a larger electric valve and increased cost.

[0009] Furthermore, in the electric valve of Patent Document 1, since the valve shaft connected to the valve core extends along the central axis of the valve seat, one of the first port and the second port needs to be positioned in a direction intersecting the axis of the valve seat to avoid interference with the valve shaft. Therefore, the flow of fluid between the first port and the second port is forced to change direction, resulting in problems such as pressure loss. Additionally, in the electric valve of Patent Document 1, it is difficult to achieve bidirectional flow due to its structure. Summary of the Invention

[0010] The purpose of this invention is to provide an electric valve that can be miniaturized with a simple structure and can suppress pressure loss to the greatest extent.

[0011] Technical means for solving technical problems

[0012] The electric valve of the present invention has the following characteristics:

[0013] Electric motor;

[0014] A driven part, the driven part having a flange portion, and the driven part being driven to rotate by the motor; and

[0015] The housing has an inlet and an outlet for fluid, and the housing houses the driven part.

[0016] The flange portion has a through opening and a shielding wall, and depending on the rotational position of the driven portion, the through opening or the shielding wall is disposed between the inflow path and the discharge path.

[0017] Invention Effects

[0018] According to the present invention, an electric valve that can be miniaturized with a simple structure and can suppress pressure loss and the like can be provided. Attached Figure Description

[0019] Figure 1 This is a perspective view of the electric valve in this embodiment, viewed from the motor side.

[0020] Figure 2 This is a perspective view of the electric valve of this embodiment from the gear section side, but a portion of the gear housing has been removed for representation.

[0021] Figure 3 This is a cross-sectional view showing the gear section cut off by a plane passing through the axis of the gear, omitting a portion of the motor section.

[0022] Figure 4 This is a perspective view of the second gear section in this embodiment.

[0023] Figure 5 This is a perspective view of the second gear section in a modified example.

[0024] Symbol Explanation

[0025] 1 Electric valve

[0026] 2. Motor Section

[0027] 3 Gear section

[0028] 31. Shell base

[0029] 315 First flow path

[0030] 316 First annular portion

[0031] 32 Gear Housing

[0032] 328 Second Flow Path

[0033] 329 Second ring portion

[0034] 33 First Gear Section

[0035] 331 First Axis

[0036] 332 drive gear

[0037] 34, 44 Second gear section

[0038] 341, 441 Second Axis

[0039] 343, 443 driven gears

[0040] 342, 442 flange portion

[0041] 34A~34F Circular Ribs

[0042] 34A1 Opening

[0043] 34B1 Shelter

[0044] 34C2 First circular opening

[0045] 34D2 Second Circular Opening

[0046] 34E2 Third circular opening

[0047] 34F2 Fourth circular opening

[0048] GC gear chamber Detailed Implementation

[0049] Hereinafter, embodiments of the electric valve of the present invention will be described with reference to the accompanying drawings. The electric valve 1 of this embodiment is connected, for example, to piping in a refrigeration cycle and can be used to control the flow of refrigerant.

[0050] (Structure of an electric valve)

[0051] Figure 1 This is a perspective view of the electric valve 1 of this embodiment as seen from the motor section side. Figure 2 This is a perspective view of the electric valve 1 of this embodiment viewed from the gear section 3 side, but a portion of the gear housing has been removed for representation. Figure 3 This is a cross-sectional view showing the gear section cut off by a plane passing through the axes of the driving gear and the driven gear, omitting a portion of the motor section 2.

[0052] The electric valve 1 has a motor section 2 and a gear section 3. The motor section 2 has a metal plate motor base 21 and a bottomed cylindrical resin cover 22, which is connected to the motor base 21. A stepper motor (not shown) is housed in the internal space formed by the motor base 21 and the cover 22.

[0053] A portion of the outer periphery of the cover 22 extends radially outward and connects to the hollow box 23. A substrate is disposed inside the box 23, and the substrate is connected to a terminal pin 24 that passes through the box 23. The stepper motor receives power from an external control device via the substrate and the terminal pin 24.

[0054] The gear part 3 has: a housing base 31, which is connected to a screw SC ( Figure 1 The housing consists of a motor base 21, a gear housing 32 connected to the housing base 31, a first gear portion 33 and a second gear portion 34 disposed within a gear chamber GC formed between the housing base 31 and the gear housing 32. The housing is formed by the housing base 31 and the gear housing 32.

[0055] The housing base 31 is provided with: a shaft hole 311 extending through the thickness direction, a first recess 312 formed on the surface facing the gear chamber GC, and a first pipe connection portion 313 formed on the surface opposite to the surface facing the gear chamber GC. The first bottom surface 314 of the first recess 312 is spherical. Inside the first pipe connection portion 313, which connects to a pipe (not shown), a first flow path 315 with a circular cross-section is formed. The inner diameter of the first flow path 315 is equal to the inner diameter of the circular ribs 34A to 34F, which will be described later. On the surface of the housing base 31 facing the gear chamber GC, a first annular portion 316 is formed protruding around the first flow path 315.

[0056] The gear housing 32 has a plate-shaped portion 321 extending parallel to the housing base 31 and a cylindrical portion 322 extending from the outer periphery of the plate-shaped portion 321 toward the housing base 31. By abutting and fixing the end of the cylindrical portion 322 to the housing base 31, a sealed gear chamber GC is formed inside it.

[0057] On the surface of the plate-shaped portion 321 facing the gear chamber GC of the gear housing 32, a second recess 323 is formed opposite to the shaft hole 311, and a third recess 324 is formed opposite to the first recess 312. The second bottom surface 325 of the second recess 323 and the third bottom surface 326 of the third recess 324 are each formed into a spherical shape.

[0058] On the side of the plate-shaped portion 321 opposite to the side facing the gear chamber GC, a second pipe connection portion 327 is formed opposite to the first pipe connection portion 313. Inside the second pipe connection portion 327, which connects to a pipe (not shown), a second flow path 328 with a circular cross-section is formed. The inner diameter of the second flow path 328 is equal to the inner diameter of the circular ribs 34A to 34F, described later. On the side of the plate-shaped portion 321 facing the gear chamber GC, a second annular portion 329 is formed protruding around the second flow path 328. The second annular portion 329 is spaced apart from the first annular portion 316 and faces it.

[0059] The first gear section 33 is formed by continuously arranging a first shaft 331 and a drive gear 332. The first shaft 331 is integral with the output shaft of the stepper motor, and the drive gear 332 is formed coaxially with the first shaft 331 around its periphery. The top end 333 of the first shaft 331 has a spherical shape corresponding to the second bottom surface 325 of the second recess 323 of the plate-shaped section 321. The first shaft 331 is fitted with the shaft hole 311 and the second recess 323 in a rotatable manner, and the second bottom surface 325 serves as a bearing portion of the first shaft 331.

[0060] The second gear portion 34, which is the driven part, is formed by continuously arranging a cylindrical second shaft 341, a disc-shaped flange portion 342, and a driven gear 343. The flange portion 342 is formed coaxially with the second shaft 341 around its periphery, and the driven gear 343 is formed on the outer periphery of the flange portion 342. The driven gear 343 meshes with the drive gear 332.

[0061] One end 344 of the second shaft 341 corresponds to the first bottom surface 314 of the first recess 312 of the housing base 31 and has a spherical shape. The other end 345 of the second shaft 341 corresponds to the third bottom surface 326 of the third recess 324 of the plate-shaped portion 321 and has a spherical shape. The second shaft 341 is fitted with the first recess 312 and the third recess 324 in a rotatable manner, and the first bottom surface 314 or the third bottom surface 326 serves as the bearing portion of the second shaft 341.

[0062] Figure 4 This is a perspective view of the second gear section 34. In the figure, on both sides of the flange section 342, the small-diameter rib 3421 and the large-diameter rib 3422 (only one side is shown) are formed in a concentric circle with respect to the second shaft 341 at the same height (distance from the surface of the flange section 342).

[0063] On both sides of the flange 342, between the small-diameter rib 3421 and the large-diameter rib 3422, six circular ribs 34A to 34F (only one side is shown in the figure) are formed at equal intervals along the circumference. The six circular ribs 34A to 34F have the same diameter and the same height (distance from the surface of the flange 342) as the small-diameter rib 3421 and the large-diameter rib 3422. A portion of the circular ribs 34A to 34F is fused with the small-diameter rib 3421 and the large-diameter rib 3422.

[0064] The inner sides of the circular ribs 34A to 34F have different shapes. Specifically, an opening 34A1 is formed on the inner side of the circular rib 34A. The inner diameter of the opening 34A1 is equal to the inner diameter of the circular rib 34A.

[0065] The inner side of the circular rib 34B adjacent to the circular rib 34A is shielded by the shielding wall 34B1.

[0066] On the inner side of the circular rib 34C adjacent to the circular rib 34B, a wall 34C1 and five first circular openings 34C2 through the wall 34C1 are formed. The total cross-sectional area of ​​the first circular openings 34C2 is smaller than the cross-sectional area of ​​the opening 34A1.

[0067] On the inner side of the circular rib 34D adjacent to the circular rib 34C, there are thirteen second circular openings 34D2 formed by the wall 34D1 and the through wall 34D1. The inner diameter of the second circular opening 34D2 is smaller than the inner diameter of the first circular opening 34C2.

[0068] On the inner side of the circular rib 34E adjacent to the circular rib 34D, a wall 34E1 and a third circular opening 34E2 through the wall 34E1 are formed. The inner diameter of the third circular opening 34E2 is smaller than the inner diameter of the second circular opening 34D2, and the number of third circular openings 34E2 is greater than the number of second circular openings 34D2.

[0069] Inside the circular rib 34F adjacent to the circular rib 34E, a wall 34F1 and a fourth circular opening 34F2 penetrating the wall 34F1 are formed. The inner diameter of the fourth circular opening 34F2 is smaller than the inner diameter of the third circular opening 34E2, and the number of fourth circular openings 34F2 is greater than the number of third circular openings 34E2. Preferably, the total cross-sectional areas of the first circular openings 34C2 to the fourth circular openings 34F2 are different from each other. The opening 34A1 and the first circular openings 34C2 to the fourth circular openings 34F2 constitute a through opening.

[0070] With the electric valve 1 assembled, depending on the rotational position of the second gear portion 34, the circular ribs 34A to 34F formed on both sides of the flange portion 342 are opposite to the first annular portion 316 and the second annular portion 329. The gap between the first annular portion 316 and the second annular portion 329 is slightly larger than the distance between the axial ends of the opposite circular ribs 34A to 34F.

[0071] (Action of the electric valve)

[0072] Here, the stepper motor of the motor section 2 has a built-in encoder that detects the rotation angle of the output shaft, i.e., the first gear section 33, and can control the rotation angle of the first gear section 33 in a closed loop based on the signal from the encoder, but it can also control the stepper motor through open-loop control.

[0073] The stepper motor of the motor section 2 is sent a control signal to the motor section 2 via the terminal pin 24 by a control device (not shown), thereby causing the second gear section 34 to rotate via the driven gear 343 that meshes with the drive gear 332 of the first gear section 33.

[0074] Furthermore, considering the transmission ratio between the first gear section 33 and the second gear section 34, the control device pre-stores the angular position of the first gear section 33 that allows any one of the circular ribs 34A to 34F to move to an angular position opposite to the first annular section 316 and the second annular section 329. The positions of the circular ribs 34A, 34C to 34F opposite to the first annular section 316 and the second annular section 329 are the valve-opening positions, and the position of the circular rib 34B opposite to the first annular section 316 and the second annular section 329 is the valve-closed position.

[0075] The first flow path (here, the inflow path) 315 side is designated as the refrigerant inflow side (high pressure side), and the second flow path (here, the outflow path) 328 side is designated as the refrigerant outflow side (low pressure side). When it is desired to cut off the refrigerant flow between the first flow path 315 and the second flow path 328, the control device drives the stepper motor to rotate the second gear section 34 to a position where the circular rib 34B is opposite to the first annular section 316 and the second annular section 329.

[0076] Since the inner side of the circular rib 34B is closed by the shielding wall 34B1, the flow of refrigerant from the first flow path 315 to the second flow path 328 can be cut off.

[0077] At this time, the second gear section 34 is displaced along the axial direction due to the pressure difference between the high-pressure side and the low-pressure side, and the circular rib 34B on the low-pressure side abuts against the second annular section 329 around its entire circumference. As a result, a seal is established between the circular rib 34B and the second annular section 329, preventing refrigerant leakage.

[0078] On the other hand, due to the gap between the circular rib 34B on the high-pressure side and the first annular portion 316, refrigerant flows out into the gear chamber GC through this gap. This refrigerant can be used for lubrication of the first gear section 33, the second gear section 34, the first shaft 331, and the second shaft 341. Even if the gear chamber GC is filled with refrigerant, the refrigerant does not flow out into the second flow path 328 because the circular rib 34B on the low-pressure side abuts against the second annular portion 329 around its circumference.

[0079] In order to achieve the desired maximum flow rate of refrigerant between the first flow path 315 and the second flow path 328, the control device drives the stepper motor to rotate the second gear section 34 to a position where the circular rib 34A is opposite to the first annular section 316 and the second annular section 329.

[0080] Therefore, the opening 34A1, which has the largest cross-sectional area and is formed on the inner side of the circular rib 34A, is connected to the first flow path 315 and the second flow path 328 in a stepless manner, thus ensuring the maximum flow rate of refrigerant from the first flow path 315 to the second flow path 328. Furthermore, the refrigerant flows directly through the opening 34A1 from the first flow path 315 to the second flow path 328 without stagnation, thus suppressing pressure loss and the generation of abnormal noise.

[0081] In addition, when it is desired that the refrigerant flows between the first flow path 315 and the second flow path 328 at a flow rate less than the maximum flow rate, the control device drives the stepper motor to rotate the second gear section 34 to any one of the circular ribs 34C to 34F, which is opposite to the first annular section 316 and the second annular section 329.

[0082] On the inner side of the circular ribs 34C to 34F, openings 34C2 to 34F2 with different cross-sectional areas are formed respectively. Therefore, the flow of refrigerant with the maximum flow rate from the first flow path 315 to the second flow path 328 can be restricted according to the selected openings 34C2 to 34F2.

[0083] The circular ribs 34C to 34F can be selected according to the mode in the refrigeration cycle to ensure the required flow rate of refrigerant. Furthermore, the refrigerant rectification effect of the circular ribs 34C to 34F is different from each other. Therefore, if an abnormal sound is generated when any one of the circular ribs 34C to 34F is aligned with the first annular portion 316 and the second annular portion 329, the second gear portion 34 can be rotated to align the other circular rib with the first annular portion 316 and the second annular portion 329.

[0084] According to this embodiment, the second flow path 328 side can also be used as the refrigerant inflow side (high-pressure side), and the first flow path 315 side can be used as the refrigerant outflow side (low-pressure side). In this case, in the closed valve position, the circular rib 34B on the low-pressure side abuts against the first annular portion 316 around its entire circumference. Therefore, even without a gasket or the like, no refrigerant leakage occurs between the circular rib 34B and the first annular portion 316, thus reducing the number of parts.

[0085] Furthermore, according to this embodiment, without providing a conversion mechanism to convert rotary motion into linear motion, the passage and cut-off of refrigerant between the first flow path 315 and the second flow path 328 can be controlled simply by rotating the second gear part 34. Therefore, a low-cost electric valve with a small number of parts and a simple and low-profile structure can be realized.

[0086] In addition, since the driving torque can be reduced, the capacity of the stepper motor can be reduced, thereby achieving energy saving.

[0087] (Modified Example)

[0088] Figure 5 This is a perspective view of the second gear section 44 involved in the modified example, with its relative position to the second flow path indicated by dashed lines or single-dot lines. The second gear section 44 can be used in place of the second gear section 34 in the electric valve 1 of the above embodiment. Since the structure other than the second gear section 34 is the same as in the above embodiment, repeated descriptions are omitted.

[0089] The second gear portion 44, which is the driven part, is formed by continuously arranging a cylindrical second shaft 441, a disc-shaped flange portion 442, and a driven gear 443. The flange portion 442 is formed coaxially with the second shaft 441 around its periphery, and the driven gear 443 is formed on the outer periphery of the flange portion 442. The driven gear 443 meshes with the drive gear 332.

[0090] The elongated hole (through opening) 44A through the flange portion 442 is formed to extend in an arc shape around the second axis 441 within an angle of approximately 300 degrees. One end of the elongated hole 44A is a semicircle with the same inner diameter as the second flow path 328, and its width narrows circumferentially as it moves away from one end.

[0091] As the second gear section 44 rotates, the elongated hole 44A shifts relative to the second flow path 328. When the elongated hole 44A shifts to the position relative to the second flow path 328 shown by the dashed line, the second annular section 329 (see reference)... Figure 3 The entire circumference of the refrigerant comes into contact with the flange (here, the shielding wall) 442, thereby cutting off the flow of refrigerant toward the second flow path 328.

[0092] On the other hand, when the elongated orifice 44A is displaced to the position relative to the second flow path 328 as shown by the single-dot dashed line, the flow path cross-sectional area is reduced because a part of the second flow path 328 is blocked by the flange portion 442, and correspondingly, the flow of refrigerant toward the second flow path 328 is restricted.

[0093] Furthermore, the present invention is not limited to the embodiments described above. Within the scope of the present invention, any modifications to the constituent elements of the above embodiments are possible. Additionally, in the above embodiments, any constituent elements may be added or omitted.

Claims

1. An electric valve, characterized in that, have: Electric motor; A driven part, the driven part having a flange portion, and the driven part being driven to rotate by the motor; and The housing has an inlet and an outlet for fluid, and the housing houses the driven part. The inflow path is on the high-pressure side, and the outflow path is on the low-pressure side. The flange portion has a through opening and a shielding wall. Depending on the rotational position of the driven portion, the through opening or the shielding wall is positioned between the inflow path and the discharge path. In the flange portion, circular ribs are formed around the through opening and the shielding wall, respectively. An annular portion is formed around the inflow path and the outflow path in the housing. The driven part is displaced relative to the housing due to the pressure difference between the high-pressure side and the low-pressure side. The circular rib on the low-pressure side abuts against the annular part on the low-pressure side around its entire circumference. A gap is generated between the circular rib on the high-pressure side and the annular part on the high-pressure side. Fluid flows through this gap into the space inside the housing that houses the driven part.

2. The electric valve according to claim 1, characterized in that, A drive gear is formed on the output shaft of the motor. The driven part has a driven gear and a shaft. The driven gear is formed on the outer periphery of the flange and meshes with the drive gear. The shaft supports the flange.

3. The electric valve according to claim 1 or 2, characterized in that, The flange portion has a plurality of through openings, and the plurality of through openings have different cross-sectional areas from each other.

4. The electric valve according to claim 1 or 2, characterized in that, The circular ribs are formed in pairs on both sides of the flange, and the annular portions sandwich the flange in a pair.

5. The electric valve according to claim 1 or 2, characterized in that, The through opening is an elongated hole whose width varies along the circumference of the flange.

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