JP7562184B2 - Motor-operated valve - Google Patents

Description

The present invention relates to a motor-operated valve.

Conventionally, motorized valves have been used as devices that are placed, for example, in the middle of a fluid piping system to open and close the fluid flow path and control the flow rate. In such motorized valves, the valve body is driven by a drive source such as a stepping motor attached to the valve body in order to accurately control the flow rate.

Patent Document 1 discloses an electric valve that allows the flow of a fluid, such as a refrigerant, between a first port and a second port by driving a valve body with a stepping motor and moving it away from a valve seat, and prevents the flow of a fluid between the first port and the second port by seating the valve body on the valve seat.

JP 2019-173877 A

The motor-operated valve of Patent Document 1 uses a conversion mechanism that uses a screw to convert the rotational motion of the stepping motor into linear motion of the valve body. This makes the structure complex, and the sliding resistance of the screw is relatively large, so the capacity of the stepping motor needs to be large, which leads to an increase in the size and cost of the motor-operated valve.

In addition, in the motor-operated valve of Patent Document 1, the valve shaft connected to the valve body extends along the central axis of the valve seat, so in order to avoid interference with the valve shaft, it is necessary to arrange either the first port or the second port in a direction that intersects with the axis of the valve seat. As a result, the flow of fluid between the first port and the second port is forced to change direction, which causes problems such as pressure loss. In addition, due to its structure, it is difficult for the motor-operated valve of Patent Document 1 to achieve bidirectional flow.

The present invention aims to provide an electrically operated valve that has a simple structure, can be made compact, and minimizes pressure loss.

The motor-operated valve according to the present invention comprises:
A motor;
a driven part including a flange part and rotated by the motor;
The drive mechanism includes a housing that includes a high-pressure inlet passage and a low-pressure outlet passage for a fluid and that houses the driven part;
the flange portion has a plurality of through openings, a shielding wall, and circular ribs formed around the plurality of through openings and the shielding wall, and any one of the plurality of through openings and the shielding wall is selectively disposed between the inlet path and the outlet path depending on a rotational position of the driven part,
The plurality of through openings have different numbers of openings and cross-sectional areas ,
An annular portion is formed on the housing opposite the circular rib,
The pressure difference between the inlet and outlet passages causes the driven part to move axially relative to the housing, and the circular rib abuts against the annular portion all around, thereby sealing the entire circumference surrounding the through opening, and fluid flows from the inlet passage to the outlet passage only through the through opening .

The present invention provides a motor-operated valve that has a simple structure, can be made compact, and minimizes pressure loss.

FIG. 1 is a perspective view of the motor-operated valve of the present embodiment, as viewed from the motor unit side. FIG. 2 is a perspective view of the motor-operated valve of this embodiment as seen from the gear portion side, with a part of the gear case removed. FIG. 3 is a cross-sectional view showing the gear portion cut along a plane passing through the axis of the gear, with part of the motor portion omitted. FIG. 4 is a perspective view of the second gear portion of the present embodiment. FIG. 5 is a perspective view of a second gear portion of a modified example.

The following describes an embodiment of the motor-operated valve according to the present invention with reference to the drawings. The motor-operated valve 1 of this embodiment can be connected to the piping of a refrigeration cycle, for example, and used to control the flow of refrigerant.

(Structure of motor-operated valve)
Fig. 1 is a perspective view of the motor-operated valve 1 of this embodiment as viewed from the motor unit side. Fig. 2 is a perspective view of the motor-operated valve 1 of this embodiment as viewed from the gear unit 3 side, with part of the gear case removed. Fig. 3 is a cross-sectional view of the gear unit cut along a plane passing through the axes of the drive gear and the driven gear, with part of the motor unit 2 omitted.

The motor-operated valve 1 has a motor section 2 and a gear section 3. The motor section 2 has a motor base 21 made of a metal plate and a cylindrical resin cover 22 with a bottom that is connected to the motor base 21. A stepping motor (not shown) is housed in the internal space formed by the motor base 21 and the cover 22.

A part of the outer periphery of the cover 22 extends radially outward and is connected to a hollow box 23, and a circuit board connected to a terminal pin 24 that penetrates the box 23 is disposed inside the box 23. The stepping motor receives power from an external control device via the circuit board and the terminal pin 24.

The gear unit 3 has a case base 31 connected to the motor base 21 via a screw SC (Figure 1), a gear case 32 connected to the case base 31, and a first gear unit 33 and a second gear unit 34 disposed in a gear chamber GC formed between the case base 31 and the gear case 32. The case base 31 and the gear case 32 form a housing.

The case base 31 is provided with an axial hole 311 penetrating in the thickness direction, a first recess 312 formed on the surface facing the gear chamber GC, and a first piping connection 313 formed on the surface opposite the surface facing the gear chamber GC. The first bottom surface 314 of the first recess 312 is spherical. A first flow path 315 with a circular cross section is formed inside the first piping connection 313 connected to a pipe not shown. The inner diameter of the first flow path 315 is equal to the inner diameter of the circular ribs 34A to 34F described later. A first annular portion 316 is formed on the surface of the case base 31 facing the gear chamber GC so as to protrude around the first flow path 315.

The gear case 32 has a plate-shaped portion 321 extending parallel to the case base 31, and a cylindrical portion 322 extending from the outer periphery of the plate-shaped portion 321 toward the case base 31. The end of the cylindrical portion 322 is abutted against the case base 31 and fixed thereto, forming a sealed gear chamber GC therein.

A second recess 323 is formed opposite the shaft hole 311 on the surface of the plate-shaped portion 321 facing the gear chamber GC of the gear case 32, and a third recess 324 is formed opposite 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 spherical.

A second pipe connection portion 327 is formed opposite the first pipe connection portion 313 on the surface of the plate-shaped portion 321 opposite the surface facing the gear chamber GC. A second flow path 328 having a circular cross section is formed inside the second pipe connection portion 327, which is connected to a pipe not shown. The inner diameter of the second flow path 328 is equal to the inner diameter of the circular ribs 34A to 34F described below. A second annular portion 329 is formed on the surface of the plate-shaped portion 321 facing the gear chamber GC so as to protrude around the periphery of the second flow path 328. The second annular portion 329 faces the first annular portion 316 with a gap therebetween.

The first gear portion 33 is formed by connecting a first shaft 331, which is integrated with the output shaft of the stepping motor, and a drive gear 332, which is formed coaxially around the first shaft 331. The tip 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 portion 321. The first shaft 331 is fitted into the shaft hole 311 and the second recess 323 so as to be capable of rotating relatively, and the second bottom surface 325 serves as a bearing portion for the first shaft 331.

The second gear portion 34, which is the driven portion, is made up of a cylindrical second shaft 341, a disk-shaped flange portion 342 formed coaxially around the second shaft 341, and a driven gear 343 formed on the outer periphery of the flange portion 342. The driven gear 343 is engaged with the drive gear 332.

One end 344 of the second shaft 341 has a spherical shape corresponding to the first bottom surface 314 of the first recess 312 of the case base 31, and the other end 345 has a spherical shape corresponding to the third bottom surface 326 of the third recess 324 of the plate-shaped portion 321. The second shaft 341 fits relatively rotatably into the first recess 312 and the third recess 324, and the first bottom surface 314 or the third bottom surface 326 serves as a bearing for the second shaft 341.

Figure 4 is a perspective view of the second gear portion 34. In the figure, a small diameter rib 3421 and a large diameter rib 3422 (only one of which is shown) are formed on both sides of the flange portion 342 concentrically with the second shaft 341 at the same height (distance from the surface of the flange portion 342).

On both sides of the flange portion 342, six circular ribs 34A to 34F (only one shown) are formed at equal intervals in the circumferential direction at positions facing each other across the flange portion 342 between the small diameter rib 3421 and the large diameter rib 3422. The six circular ribs 34A to 34F have the same diameter and the same height (distance from the surface of the flange portion 342) as the small diameter rib 3421 and the large diameter rib 3422. Parts of the circular ribs 34A to 34F are fused with the small diameter rib 3421 and the large diameter rib 3422.

The insides of the circular ribs 34A to 34F have different shapes. Specifically, an opening 34A1 is formed on the inside of the circular rib 34A. The inner diameter of the opening 34A1 is equal to the inner diameter of the circular rib 34A.

The inside of circular rib 34B adjacent to circular rib 34A is shielded by shielding wall 34B1.

A wall 34C1 and five first circular openings 34C2 penetrating the wall 34C1 are formed on the inside of the circular rib 34C adjacent to the circular rib 34B. The total cross-sectional area of the first circular openings 34C2 is smaller than the cross-sectional area of the opening 34A1.

A wall 34D1 and thirteen second circular openings 34D2 penetrating the wall 34D1 are formed on the inside of the circular rib 34D adjacent to the circular rib 34C. The inner diameter of the second circular openings 34D2 is smaller than the inner diameter of the first circular openings 34C2.

A wall 34E1 and a third circular opening 34E2 penetrating the wall 34E1 are formed on the inside of the circular rib 34E adjacent to the circular rib 34D. 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 the third circular openings 34E2 is greater than the number of the second circular openings 34D2.

A wall 34F1 and a fourth circular opening 34F2 penetrating the wall 34F1 are formed on the inside of the circular rib 34F adjacent to the circular rib 34E. 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 the fourth circular openings 34F2 is greater than the number of the third circular openings 34E2. It is preferable that the total cross-sectional areas of the first circular opening 34C2 to the fourth circular opening 34F2 are different from each other. The opening 34A1 and the first circular opening 34C2 to the fourth circular opening 34F2 form a penetrating opening.

When the motor-operated valve 1 is assembled, the circular ribs 34A-34F formed on both sides of the flange portion 342 face the first annular portion 316 and the second annular portion 329 depending on the rotational position of the second gear portion 34. 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 opposing circular ribs 34A-34F.

(Operation of motor-operated valve)
Here, the stepping 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 the stepping motor may also be controlled by open loop control.

By sending a control signal from a control device (not shown) to the stepping motor of the motor unit 2 via the terminal pin 24, the second gear unit 34 rotates via the driven gear 343 that meshes with the drive gear 332 of the first gear unit 33.

Note that the control device prestores, taking into account the gear ratio between the first gear portion 33 and the second gear portion 34, the angular positions of the first gear portion 33 at which any of the circular ribs 34A to 34F can move to an angular position facing the first annular portion 316 and the second annular portion 329. The position at which the circular ribs 34A, 34C to 34F face the first annular portion 316 and the second annular portion 329 is the valve open position, and the position at which the circular rib 34B faces the first annular portion 316 and the second annular portion 329 is the valve closed position.

The first flow path (here, the inlet path) 315 side is the inlet side (high pressure side) of the refrigerant, and the second flow path (here, the outlet path) 328 side is the outlet side (low pressure side) of the refrigerant. When it is desired to block the flow of refrigerant between the first flow path 315 and the second flow path 328, the control device drives the stepping motor to rotate the second gear portion 34 to a position where the circular rib 34B faces the first annular portion 316 and the second annular portion 329.

The inside of the circular rib 34B is closed by a shielding wall 34B1, so the flow of refrigerant from the first flow path 315 to the second flow path 328 can be blocked.

At this time, the second gear portion 34 is displaced in 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 comes into contact with the second annular portion 329 all around. This establishes a seal between the circular rib 34B and the second annular portion 329, preventing refrigerant leakage.

Meanwhile, a gap is created between the high-pressure side circular rib 34B and the first annular portion 316, and refrigerant flows out from this gap into the gear chamber GC. This refrigerant can be used to lubricate the first gear portion 33, the second gear portion 34, the first shaft 331, and the second shaft 341. Even if the gear chamber GC is filled with refrigerant, the low-pressure side circular rib 34B and the second annular portion 329 are in contact around the entire circumference, so the refrigerant does not flow out into the second flow path 328.

In contrast, when it is desired to flow the refrigerant at the maximum flow rate between the first flow path 315 and the second flow path 328, the control device drives the stepping motor to rotate the second gear portion 34 to a position where the circular rib 34A faces the first annular portion 316 and the second annular portion 329.

As a result, the opening 34A1, which is formed on the inside of the circular rib 34A and has the largest cross-sectional area, is connected to the first flow path 315 and the second flow path 328 without creating a step, ensuring the maximum flow rate of refrigerant from the first flow path 315 to the second flow path 328. In addition, the refrigerant flowing from the first flow path 315 to the second flow path 328 passes through the opening 34A1 straight without stagnation, which reduces pressure loss and suppresses the generation of abnormal noise.

Furthermore, if it is desired to flow the refrigerant 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 stepping motor to rotate the second gear portion 34 to a position where any one of the circular ribs 34C to 34F faces the first annular portion 316 and the second annular portion 329.

Openings 34C2 to 34F2 with different cross-sectional areas are formed on the inside of the circular ribs 34C to 34F, respectively, so that the maximum flow rate of refrigerant can be restricted from the first flow path 315 to the second flow path 328 depending on the opening 34C2 to 34F2 selected.

The circular ribs 34C to 34F can be selected to ensure the required flow rate of refrigerant depending on the mode of the refrigeration cycle. The circular ribs 34C to 34F also have different refrigerant straightening effects. Therefore, if abnormal noise occurs when any of the circular ribs 34C to 34F are opposed to the first annular portion 316 and the second annular portion 329, the second gear portion 34 can be rotated so that another circular rib is opposed to the first annular portion 316 and the second annular portion 329.

According to this embodiment, the second flow path 328 side can be the refrigerant inlet side (high pressure side), and the first flow path 315 side can be the refrigerant outlet side (low pressure side). In this case, in the closed valve position, the low pressure side circular rib 34B abuts against the first annular portion 316 all around. This prevents refrigerant leakage between the circular rib 34B and the first annular portion 316 without the need for a packing or the like, thereby reducing the number of parts.

Furthermore, according to this embodiment, there is no conversion mechanism for converting rotational motion into linear motion, and the passage and blocking of refrigerant between the first flow path 315 and the second flow path 328 can be controlled simply by rotating the second gear portion 34, making it possible to realize a low-cost motor-operated valve with a small number of parts and a simple, low-profile structure.

In addition, because less drive torque is required, the capacity of the stepping motor can be reduced, thereby saving energy.

(Modification)
5 is a perspective view of the second gear portion 44 according to the modified example, and the relative position with respect to the second flow path is indicated by a dotted line or a dashed line. The second gear portion 44 can be used in place of the second gear portion 34 in the motor-operated valve 1 of the above embodiment. The structure other than the second gear portion 34 is the same as in the above embodiment, so a duplicated description will be omitted.

The second gear portion 44, which is the driven portion, is made up of a cylindrical second shaft 441, a disk-shaped flange portion 442 formed coaxially around the second shaft 441, and a driven gear 443 formed on the outer periphery of the flange portion 442. The driven gear 443 meshes with the drive gear 332.

The long hole (through opening) 44A that penetrates the flange portion 442 is formed so as to extend in an arc shape over an angle of approximately 300 degrees around the second axis 441. One end of the long hole 44A is semicircular with the same inner diameter as the second flow path 328, and the width narrows as it moves away from the one end in the circumferential direction.

As the second gear portion 44 rotates, the long hole 44A is displaced relative to the second flow path 328. When the long hole 44A is displaced to the position relative to the second flow path 328 shown by the dotted line, the entire circumference of the second annular portion 329 (see FIG. 3) abuts against the flange portion (here, the shielding wall) 442, blocking the flow of refrigerant toward the second flow path 328.

On the other hand, when the long hole 44A is displaced so that it is positioned relative to the second flow path 328 as shown by the dashed line, a portion of the second flow path 328 is blocked by the flange portion 442, reducing the flow path cross-sectional area, and accordingly restricting the flow of refrigerant toward the second flow path 328.

The present invention is not limited to the above-described embodiment. Any of the components of the above-described embodiment may be modified within the scope of the present invention. Any of the components of the above-described embodiment may be added or omitted.

REFERENCE SIGNS LIST 1 Motor-operated valve 2 Motor section 3 Gear section 31 Case base 315 First flow path 316 First annular section 32 Gear case 328 Second flow path 329 Second annular section 33 First gear section 331 First shaft 332 Drive gear 34, 44 Second gear section 341, 441 Second shaft 343, 443 Driven gear 342, 442 Flange section 34A to 34F Circular rib 34A1 Opening 34B1 Shielding wall 34C2 First circular opening 34D2 Second circular opening 34E2 Third circular opening 34F2 Fourth circular opening GC Gear chamber

Claims (3)

A motor;
a driven part including a flange part and rotated by the motor;
The drive mechanism includes a housing that includes a high-pressure inlet passage and a low-pressure outlet passage for a fluid and that houses the driven part;
the flange portion has a plurality of through openings, a shielding wall, and circular ribs formed around the plurality of through openings and the shielding wall, and any one of the plurality of through openings and the shielding wall is selectively disposed between the inlet path and the outlet path depending on a rotational position of the driven part,
The plurality of through openings have different numbers of openings and cross-sectional areas ,
An annular portion is formed on the housing opposite the circular rib,
A pressure difference between the inlet passage and the outlet passage causes the driven part to move in the axial direction relative to the housing, and the circular rib abuts against the annular part over the entire circumference, thereby sealing the entire circumference surrounding the through opening, and fluid flows from the inlet passage to the outlet passage only through the through opening.
A motor-operated valve. A drive gear is formed on an output shaft of the motor, and the driven part has a driven gear formed on an outer periphery of the flange part and meshing with the drive gear, and a shaft supporting the flange part.
2. The motor-operated valve according to claim 1 . The circular ribs are formed in pairs on both side surfaces of the flange portion, and a pair of annular portions of the housing are formed in pairs on both sides of the flange portion, and the pair of annular portions of the housing are formed in pairs on both sides of the flange portion,
When one of the circular ribs abuts against one of the annular portions over the entire circumference, a gap is formed between the other of the circular ribs and the other of the annular portions, and the fluid on the inlet side is supplied to the space accommodating the driven portion through the gap.
3. The motor-operated valve according to claim 1 or 2.

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