CN117267413A

CN117267413A - Valve device

Info

Publication number: CN117267413A
Application number: CN202310724888.2A
Authority: CN
Inventors: 曾我拓巨; 木村宏光; 南泽英树
Original assignee: Saginomiya Seisakusho Inc
Current assignee: Saginomiya Seisakusho Inc
Priority date: 2022-06-22
Filing date: 2023-06-19
Publication date: 2023-12-22
Also published as: JP2024001696A; DE102023115703A1

Abstract

The invention provides a valve device, which can prevent the worm from locking by reducing friction between the worm and a part supporting the worm, and improve the stability of switching action of a valve port of a main valve. A rotary switching valve (100) as a valve device is provided with a valve body (1), a main valve (3), and a driving unit (5). The main valve (3) is rotationally driven by the driving unit (5), and the rotation is stopped by the main valve stopper (9) of the valve body (1). The driving unit (5) is provided with a worm (52) rotated by an electric motor (51) and a worm wheel (54) engaged with the worm (52). The worm (52) is supported rotatably about the axis (A) and movable in the direction of the axis (A) by at least 1 rotation support section (53). The rotation support part (53) is provided with a locking prevention mechanism for preventing the locking of the worm (52).

Description

Valve device

Technical Field

The present invention relates to a valve device.

Background

As a valve device for controlling the flow rate of a fluid, a rotary switching valve including a valve housing, a main valve, a sub-valve, and a driving unit is known (for example, refer to patent documents 1 and 2). In these rotary switching valves, the sub-valve is driven to rotate by a worm gear having a worm rotated by an electric motor and a worm wheel meshed with the worm, and the rotation of the sub-valve is transmitted to a main valve, thereby switching the valve ports. The main valve stops rotating at a predetermined switching position by abutting against a valve stopper of the valve housing, and the sub-valve stops rotating by abutting against a sub-valve stopper of the main valve, and then when a signal that is still rotating in the rotating direction is sent to the electric motor, the worm moves in the axial direction of the worm, that is, in the thrust direction, and abuts against the worm support portion to stop.

Prior art literature

Patent document 1: japanese patent laid-open No. 2009-270639

Patent document 2: japanese patent application laid-open No. 2021-124119

However, in the worm gear described above, the worm comes into contact with the worm support portion, and the worm is inserted between the meshing portion of the worm wheel and the worm support portion, and friction is generated in the meshing portion and the worm support portion, respectively, so that a phenomenon in which the worm cannot be reversed (in this specification, this phenomenon is defined as "worm lock" for use) may occur, and stability of switching operation of the valve port by the main valve, that is, the valve element may be hindered.

Disclosure of Invention

The invention aims to obtain a valve device, which can prevent the worm from locking and improve the stability of the switching action of a valve core to a valve port by reducing the friction between the worm and a part supporting the worm.

In order to solve the above problems and achieve the object, a valve device according to the present invention includes a valve body, and a driving unit, wherein the valve body is rotationally driven by the driving unit, and the valve body is stopped from rotating by a stopper of the valve body, and the valve device includes: a worm rotated by an electric motor; and a worm wheel engaged with the worm, wherein the worm is supported by at least 1 part of rotation support parts capable of rotating around an axis and moving along an axial direction, and the rotation support parts are provided with a locking prevention mechanism for preventing the locking of the worm.

According to the present invention, the worm is supported rotatably about the shaft and axially movable by the rotation support portion having the lock preventing mechanism. Therefore, if the electric motor continues to rotate after the rotation of the valve body is stopped by receiving a signal that is still rotating in the rotation direction, even if the worm moves in the axial direction of the worm and abuts against the rotation support portion, the penetration of the worm, the friction force of the meshing portion of the worm and the worm wheel, and the friction force of the worm and the rotation support portion can be reduced by preventing the locked worm from rotating around the shaft, and the like. Therefore, by reducing friction between the worm and the portion supporting the worm, the worm is prevented from locking, and the valve device can be obtained in which the stability of the switching operation of the valve port of the valve element is improved.

In this case, it is preferable that the lock prevention mechanism is constituted by a bearing provided in the rotation support portion, and the movement in the axial direction of the worm is restricted by abutting against an end surface of the bearing. According to this configuration, the lock prevention mechanism is constituted by the bearing provided in the rotation support portion, and the movement of the worm in the axial direction can be restricted by the end surface of the bearing while preventing the worm from being locked.

Further, a radial gap is preferably provided between the worm and the inner diameter of the bearing. According to this configuration, if the electric motor continues to rotate after the rotation of the valve body is stopped by receiving a signal that is still rotating in the rotation direction, the worm can be displaced by an amount corresponding to the radial gap and slide along the inner diameter of the bearing even if the worm moves in the axial direction of the worm, that is, in the thrust direction and comes into contact with the end surface of the bearing. Therefore, the worm is prevented from being inserted between the engagement portion and the bearing by displacement or sliding of the worm, and friction generated in the engagement portion or the bearing can be reduced.

Preferably, the worm includes a shaft portion, a stepped portion, and a reduced diameter portion, the reduced diameter portion is inserted into the bearing, and an axial gap is provided between the stepped portion and an end surface of the bearing in a state where rotation of the valve body is stopped. According to this configuration, since the axial gap is provided between the stepped portion of the worm and the end surface of the bearing in a state where the rotation of the valve body is stopped, the worm can move in the axial direction of the worm if the electric motor continues to rotate after the rotation of the valve body is stopped by receiving a signal that is still rotating in the rotation direction. In addition, in the case where the worm moves in the axial direction and contacts the bearing, the worm can be moved by only an amount corresponding to the above-described axial gap by rotating the worm in the reverse direction. Therefore, friction force generated in the meshing portion can be reduced, and the worm can be easily prevented from locking.

Preferably, the bearing includes an inner ring, an outer ring, and a rolling member, and is adapted to be abutted against an end surface of the inner ring to restrict movement of the worm in an axial direction. According to this configuration, the worm can be prevented from being locked by the bearing constituted by the bearing.

The bearing may be a cylindrical bush having a low sliding resistance. According to this structure, the worm can be prevented from locking by the bearing composed of the bush having a low sliding resistance and formed in a cylindrical shape.

Further, it is preferable that the rotation support portion is disposed on a side of the worm in the axial direction, that is, on a side on which the electric motor is disposed. According to this configuration, even if the electric motor continues to rotate by receiving a signal that is still rotating in the rotation direction after the rotation of the valve body is stopped, the worm moves to the axial side, and the worm can be prevented from being locked by the rotation support portion disposed on the axial side of the worm.

Preferably, the driving unit includes a biasing member for biasing the worm shaft toward one side in the axial direction, and the biasing member generates a force greater than an axial force, i.e., a thrust force, which acts on the worm shaft toward the other side in the axial direction of the worm shaft by meshing with the worm wheel. According to this configuration, even if the electric motor continues to rotate by receiving a signal that is still rotating in the rotation direction after the rotation of the valve body is stopped, and the worm is to be moved to the other side in the axial direction, the movement can be suppressed by the urging member having a larger urging force than the urging force acting on the worm to the other side in the axial direction.

Further, it is preferable that the rotation support portion is also disposed on the other axial side of the worm. According to this configuration, since the worm can be supported by the rotation support portions disposed on one side and the other side in the axial direction of the worm, the rotation support portions disposed on both end sides in the axial direction of the worm can suppress the vibration of the worm in the direction intersecting the axial direction.

The rotary switching valve according to the present invention is the valve device according to any one of the above, comprising: a valve chamber provided in the valve main body; a valve seat portion having a plurality of valve ports opening to the valve chamber; a main valve rotatably provided inside the valve main body around a central axis intersecting the valve seat portion; and a sub-valve rotatably provided around the central axis to open and close the pressure equalizing hole of the main valve, wherein rotation of the sub-valve rotationally driven by the driving unit is transmitted to the main valve to switch the valve port. According to this configuration, the friction between the worm and the portion supporting the worm is reduced, so that the worm is prevented from locking, and the rotary switching valve can be obtained in which the stability of the switching operation of the valve port of the main valve is improved.

The effects of the present invention are as follows.

According to the present invention, the friction between the worm and the portion supporting the worm is reduced, so that the worm is prevented from locking, and the valve device can be obtained in which the stability of the switching operation of the valve element to the valve port is improved.

Drawings

Fig. 1 is an assembled cross-sectional view of a valve device according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of the driving portion of the valve device.

Fig. 3 is a cross-sectional view showing a state in which rotation of the sub-valve and the main valve about the center axis is restricted.

Fig. 4 is a view showing the worm when rotation of the sub-valve and the main valve about the central axis is restricted.

Fig. 5 is a view showing a worm in a state of abutting against the rotation support portion.

Fig. 6 is a cross-sectional view showing the rotation support portion in the first modification.

Fig. 7 is a cross-sectional view showing a driving unit and a worm in a second modification.

Fig. 8 (a) is a schematic diagram of the refrigeration cycle system showing a state during the cooling operation, and (B) is a schematic diagram of the refrigeration cycle system showing a state during the heating operation.

In the figure: 1-valve main body, 3-main valve (valve core), 5-driving part, 9-main valve limiter (limiter), 51-electric motor, 52-worm, 53-rotation supporting part, 54-worm wheel, 100-rotation switching valve (valve device).

Detailed Description

Hereinafter, an embodiment of a rotary switching valve 100 as a valve device according to the present invention will be described with reference to fig. 1 to 5 and fig. 8. In fig. 1, the arrows X and Y are orthogonal to each other, and the arrow X is defined as the axial direction of the valve body 1 and the center shaft 6, and is referred to as the "axial X direction". One side in the axis X direction is referred to as "upper side X1", and the other side is referred to as "lower side X2". The intersecting direction intersecting the axis X direction is denoted by an arrow Y, and is referred to as "radial direction Y". In particular, in the radial direction Y, the side on which the center axis 6 is located is referred to as the "inner side", and the opposite side to the inner side is referred to as the "outer side". This is for convenience of description, and does not necessarily coincide with the direction in the actual use state of the rotary switching valve 100, and does not limit the direction in the actual use state of the rotary switching valve 100.

The rotary switching valve 100 includes a valve body 1, a valve seat member 2, a main valve 3 (valve body), a sub-valve 4, a driving unit 5, and a center shaft 6. The valve body 1 includes a cylindrical first cylindrical portion 10 extending in the direction of the axis X, and a bottomed cylindrical second cylindrical portion 11 continuous with the first cylindrical portion 10 and having a smaller diameter than the first cylindrical portion 10, and accommodates the main valve 3, the sub-valve 4, the driving portion 5, and the center shaft 6. The interior of the first cylindrical portion 10 constitutes a valve chamber 10a. The second cylindrical portion 11 mainly includes a housing portion 11a for housing the driving portion 5 and the like.

The valve seat member 2 includes a cylindrical valve seat portion 20 and a flange portion 21 formed on the outer periphery of the valve seat portion 20. The valve body 1 is fitted so that the outer peripheral surface of the valve seat portion 20 contacts the inner peripheral surface of the first cylindrical portion 10, and the upper surface thereof forms a valve seat surface 20a extending in the radial direction Y. As shown in fig. 8 (a) and (B), the valve seat portion 20 is provided with 4 valve ports 20D, 20S, 20C, and 20E penetrating from the lower end portion of the valve seat portion 20 to the valve seat surface 20a and opening to the valve chamber 10 a. The valve ports 20D, 20S, 20C, 20E are each opened at positions 90 ° apart.

As shown in fig. 8 (a) and (B), the 4 ports include: a D port 20D communicating with the valve chamber 10a and the discharge side of the refrigerant of the compressor P; an S port 20S communicating with a suction side of the refrigerant of the compressor P; a C switching port 20C communicating with the outdoor heat exchanger 60 side; and an E switching port 20E which communicates with the indoor heat exchanger 80 side. The ports 20D, 20S, 20C, and 20E are connected to the joint pipe 8 (only shown in fig. 1) to constitute a flow path of the refrigerant. The flange portion 21 is fixed to the valve body 1 by welding in a state where the upper surface thereof is in contact with the lower end surface of the first cylindrical portion 10.

The main valve 3 is a member formed of resin, and is provided rotatably around a center axis 6 and displaceable in the direction of the axis X inside the valve body 1. As shown in fig. 1, the main valve 3 includes a bowl-shaped bowl portion 30 that opens to the lower side X2 (the valve seat portion 20 side), and a cylindrical piston portion 31 that extends upward X1 continuously from the bowl portion 30. The bowl portion 30 is formed with a low-pressure flow path 30L and a high-pressure flow path 30H that open to the valve seat surface 20a, and a pressure equalizing hole 30a that communicates with the housing portion 11a from the top of the low-pressure flow path 30L.

The low-pressure flow path 30L is a valve path that communicates with 2 adjacent ports among the above-described valve ports 20D, 20S, 20C, and 20E, and is provided so as to face the high-pressure flow path 30H through the center axis 6. The low-pressure flow path 30L is provided with a rib 32 protruding from an opening edge thereof toward the lower side X2, and a lower end surface of the rib 32 constitutes a low-pressure seal surface 32a. The low-pressure sealing surface 32a is in sliding contact with the valve seat surface 20a, and 2 of the 4 ports 20D, 20S, 20C, and 20E are communicated with each other through a space surrounded by the low-pressure sealing surface 32a and the valve seat surface 20a and separated from the valve chamber 10 a.

In the low-pressure flow path 30L, a reinforcing member 7 is provided from the inner wall in the radial direction Y to the outer wall in the radial direction Y. The reinforcement member 7 is a member for preventing the low-pressure flow path 30L from being deformed by a stress caused by a pressure difference between the inside and outside of the main valve 3, and is formed in a rod shape from a metal material, a resin, or the like, and is fixed in the low-pressure flow path 30L by press fitting or the like.

The high-pressure flow path 30H is a valve path that communicates adjacent 2 ports among the respective valve ports 20D, 20S, 20C, 20E. A cutout portion 30H1 is formed in the wall of the high-pressure flow path 30H on the outer side in the radial direction Y, toward the inner side in the radial direction Y in the cross-sectional view in the figure. Thus, the high-pressure flow path 30H is a space that is always open and is not isolated from the valve chamber 10 a.

A pair of sliding ribs 30b protruding downward X2 are formed on the bottom surface of the bowl 30. As shown in fig. 8 (a) and (B), the sliding rib 30B is formed at a semicircular portion on the side of the bottom surface of the bowl portion 30 where the high-pressure flow path 30H is formed, at intervals in the circumferential direction.

The piston portion 31 is formed so as to fit around the piston portion, and the piston ring R is in sliding contact with the inner peripheral surface of the second cylindrical portion 11 when the main valve 3 is displaced in the direction of the axis X as shown in fig. 1. A cylindrical recess opening upward X1 is formed in the center of the piston 31, and the recess constitutes a sub-valve accommodation chamber 31a accommodating the sub-valve 4.

As shown in fig. 1, a columnar sub-valve stopper 31a1 (stopper) protruding inward in the radial direction Y and extending in the axis X direction is formed on the inner peripheral surface of the sub-valve accommodation chamber 31a. As shown in fig. 3, the sub-valve stoppers 31a1 are formed at 2 intervals in the circumferential direction around the center shaft 6 (around the axis X) in the circumferential direction. The sub-valve stopper 31a1 is a portion that abuts against an enlarged diameter portion 40a of the sub-valve 4 described later to stop rotation of the sub-valve 4.

A main valve side clutch portion 33 is formed on the bottom surface of the sub valve housing chamber 31a. As shown in fig. 1, the main valve side clutch portion 33 is constituted by 3 main valve projections 33a projecting upward X1 and formed at equal intervals in the circumferential direction around the center axis 6. The cross-sectional shape of each main valve protrusion 33a around the center axis 6 is trapezoidal, and both the left and right end portions around the center axis 6 are tapered surfaces inclined in directions approaching each other as going toward the upper side X1. The upper side X1 of the pressure equalizing hole 30a is open to 1 of the main valve projections 33 a. The upper surface of the main valve boss 33a where the pressure equalizing hole 30a opens forms a surface that contacts the lower end surface of a sub valve boss 42a described later.

The center portion of the bottom surface of the sub-valve housing chamber 31a constitutes a bearing portion of the center shaft 6, and a shaft insertion hole 3a penetrating to the lower end portion of the bowl portion 30 in the direction of the axis X is formed in the center of the bearing portion. A lower portion 6B of the center shaft 6 is inserted into the shaft insertion hole 3a, and thereby the main valve 3 is supported rotatably about the center shaft 6 and displaceable in the axis X direction between a first switching position (switching position, position shown in fig. 8 a) and a second switching position (switching position, position shown in fig. 8B) in contact with the main valve stopper 9 (stopper).

The sub-valve 4 is a member made of metal, and is provided rotatably around the center shaft 6 and displaceable in the direction of the axis X, similarly to the main valve 3. As shown in fig. 1, the sub-valve 4 includes: a substantially disk-shaped flange portion 40 which is accommodated in the sub-valve accommodation chamber 31a; and a boss portion 41 formed in the center of the flange portion 40 and extending in the axis X direction. As shown in fig. 3, an enlarged diameter portion 40a protruding outward in the radial direction Y from the other portion is formed at a portion of the flange portion 40 substantially in the circumferential direction, one circumferential end portion of the enlarged diameter portion 40a is configured to abut against one of the sub-valve stoppers 31a1, and the other circumferential end portion of the enlarged diameter portion 40a is configured to abut against the other of the sub-valve stoppers 31a 1.

Specifically, when the sub-valve 4 rotates about the center axis 6 in a state where the main valve 3 is restricted from rotating in the first switching position or the second switching position by abutting against the main valve stopper 9 (in a rotation stopped state), the one end portion in the circumferential direction or the other end portion in the circumferential direction of the expanded diameter portion 40a abuts against the sub-valve stopper 31a 1. The rotation of the sub valve 4 about the center shaft 6 is restricted by this abutment. In the present embodiment, as shown in fig. 3, the maximum rotation amount of the sub-valve 4 about the center axis 6 with respect to the valve main body 1 is set to about 210 ° according to the positional relationship (how much the sub-valve stoppers 31a1 are separated in the circumferential direction) of the main valve 3.

As shown in fig. 1, a sub-valve side clutch portion 42 is formed on the lower surface of the flange portion 40. The sub-valve side clutch portion 42 is constituted by sub-valve protrusions 42a, and the sub-valve protrusions 42a protrude downward X2 on the same circumference as the main valve protrusion 33a, and are formed in 3 pieces at equal intervals in the circumferential direction around the center shaft 6. 1 of the main valve projections 33a can be positioned between one sub-valve projection 42a and the other sub-valve projection 42a, whereby the main valve side clutch portion 33 and the sub-valve side clutch portion 42 are engaged with each other. The cross-sectional shape of the sub-valve protrusion 42a around the center axis 6 is trapezoidal, and both the left and right end portions around the center axis 6 are tapered surfaces inclined in directions approaching each other as going toward the lower side X2.

As described above, the lower end surface of the sub-valve protrusion 42a is configured to contact the upper surface of the main valve protrusion 33a, and this surface is configured to open and close the pressure equalizing hole 30a while sliding in contact with the upper surface of the main valve protrusion 33a in accordance with the rotation of the sub-valve 4.

A pressure equalizing flow path, not shown, is formed between the one sub-valve protrusion 42a and the other sub-valve protrusion 42a on the lower surface of the flange 40, and is communicable with the pressure equalizing hole 30a. Therefore, while the pressure equalizing hole 30a is closed by the lower end surface of the sub-valve protrusion 42a, the high-pressure valve chamber 10a and the low-pressure flow path 30L are partitioned, and while the pressure equalizing flow path communicates with the pressure equalizing hole 30a, the pressure of the fluid on the upper side X1 outside the main valve 3 escapes into the low-pressure flow path 30L (low-pressure side), and the pressures on the upper side X1 of the main valve 3 and the low-pressure flow path 30L become uniform.

A square hole 41a that opens to the upper side X1 is formed in the center of the boss portion 41. The square hole 41a is a portion in which the sub-valve 4 and a worm wheel 54 described later can transmit rotational force about the center shaft 6 to each other, and is formed so that a cam portion 54b of the worm wheel 54 can be fitted therein, as shown in fig. 1. A shaft insertion hole 4a penetrating to the lower end of the flange 40 along the axis X is formed in the center of the bottom of the square hole 41a. An upper portion 6a of the center shaft 6, which will be described later, is inserted into the shaft insertion hole 4a, whereby the sub valve 4 is supported rotatably about the center shaft 6 and displaceable in the axis X direction.

The driving unit 5 is a portion that rotationally drives the sub-valve 4, and includes a housing 50, an electric motor 51, a worm 52, a rotation support 53, a worm wheel 54, a first coil spring 55 (urging member), and a second coil spring 56 (only shown in fig. 1), as shown in fig. 2. In fig. 2, 4, and 5 referred to in the description of the drive unit 5 below, a direction extending in a direction orthogonal to the radial direction Y in a plane of the rotary switching valve 100 in plan view is referred to as an axial direction of the worm 52, and in particular, an axis a direction. In the axis a direction, one side where the electric motor 51 is located is defined as one side A1, and the opposite side is defined as the other side A2. The radial direction Y also indicates the radial direction of the worm 52.

The housing portion 50 constitutes a part of the second cylindrical portion 11 of the valve body 1, and includes a housing portion 50a extending in the direction of the axis a, a connecting portion 50b fixed to one side A1 of the housing portion 50a, and a case 50c fixed to one side A1 of the connecting portion 50 b. The housing portion 50a is formed in a cylindrical shape extending in the direction of the axis a, and houses the worm 52 therein. The connection portion 50b is formed in a tubular shape, and is welded and fixed to the housing portion 50a in a state where the other side A2 is partially fitted into the one side A1 of the housing portion 50a. The case 50c is formed in a hat shape protruding toward the one side A1, and an opening end edge of the other side A2 is fixed to an end of the one side A1 of the connecting portion 50b by welding, whereby the space inside the housing portion 50a is sealed.

In the present embodiment, the electric motor 51 is a stepping motor, and includes: a magnetic rotor 51a provided inside the case 50c and rotatable about an axis a (around a shaft); and a stator coil 51b fixed to the outer periphery of the magnetic rotor 51a through a case 50 c. The electric motor 51 can adjust the rotation direction and the rotation amount of the worm 52 by a control unit, not shown. For example, in the present embodiment, by transmitting a predetermined pulse from the control unit, the worm 52 is rotated in a first direction which is a direction in which the sub-valve 4 is rotated leftward around the center axis 6 and in a second direction which is a direction opposite to the first direction. The relation between the predetermined pulse and the rotation angle of the sub-valve 4 is, for example, 210 ° at 1400 pulses, and as described above, the maximum rotation amount of the sub-valve 4 about the center axis 6 with respect to the valve main body 1 is about 210 °, and therefore, theoretically, the sub-valve 4 rotates by the maximum rotation amount at 1400 pulses.

The worm 52 is a metal member rotationally driven by the electric motor 51, is fixed to the center of the magnetic rotor 51a, extends in the direction of the axis a, and is provided integrally with the magnetic rotor 51a so as to be rotatable about the axis a. The worm 52 includes a drive shaft 52a, a first reduced diameter portion 52b (reduced diameter portion), a first stepped portion 52c (stepped portion), a shaft portion 52d, a gear portion 52e, a second stepped portion 52f (stepped portion), and a second reduced diameter portion 52g (reduced diameter portion) from one side A1 to the other side A2. The drive shaft 52a is a portion constituting an end portion of one side A1 of the worm 52, and is fixed to the magnetic rotor 51a so as to penetrate the center of the magnetic rotor 51a.

The first reduced diameter portion 52b is formed to have a larger diameter than the drive shaft 52a, and extends to the vicinity of the end portion of the one side A1 of the connecting portion 50 b. The first stepped portion 52c is continuous with the first reduced diameter portion 52b, and is formed toward the radial direction Y outside of the worm 52. The shaft portion 52d is continuous with the first stepped portion 52c, extends in the axis a direction, and has a larger diameter than the first reduced diameter portion 52b. The gear portion 52e is a portion that meshes with the tooth portion 54a of the worm wheel, and is formed from the intermediate portion of the shaft portion 52d in the axis a direction to the other side A2. The second step 52f is continuous with the end of the other side A2 of the shaft 52d, and is formed toward the inside in the radial direction Y of the worm 52. The second reduced diameter portion 52g is continuous with the second stepped portion 52f, extends in the axis a direction, and has substantially the same diameter as the first reduced diameter portion 52b.

The rotation support portion 53 is a bearing that supports the worm 52 rotatably about the axis a and movable in the direction of the axis a, and in the present embodiment, is constituted by a ball bearing including an inner ring 53a, an outer ring 53b, and a spherical rolling member 53c sandwiched between the inner ring 53a and the outer ring 53 b. In the present embodiment, the rotation support portions 53 are provided on one side A1 and the other side A2 of the worm 52, respectively. The rotation support portion 53 disposed on the one side A1 is fixed by fitting the outer ring 53b into the end portion of the one side A1 of the connecting portion 50b, and the first diameter-reduced portion 52b of the worm 52 is inserted into the inner ring 53a of the rotation support portion 53. The rotation support portion 53 disposed on the other side A2 is fixed by fitting the outer ring 53b into the end portion of the other side A2 of the housing portion 50a, and the second reduced diameter portion 52g is inserted into the inner ring 53a of the rotation support portion 53.

In fig. 2, 4, and 5, the outer peripheral surface of the first diameter-reduced portion 52b is seen to abut against the inner peripheral surface of the inner ring 53a of the rotation support portion 53, but a first gap S1 is set to be generated between the outer peripheral surface and the inner peripheral surface as a gap in the radial direction Y. Similarly, a first gap S1 is generated between the outer peripheral surface of the second reduced diameter portion 52g and the inner peripheral surface of the inner ring 53 a. That is, a gap in the radial direction Y is provided between the worm 52 and the inner diameter of the rotation support portion 53 (the inner diameter of the bearing).

The worm wheel 54 is a cylindrical member that rotates in mesh with the worm 52, and includes a tooth portion 54a that meshes with the gear portion 52e and a cam portion 54b that is connected to the sub valve 4. As shown in fig. 2, the teeth 54a are formed over the entire outer peripheral surface of the worm wheel 54. As shown in fig. 1, the cam portion 54b is a portion protruding downward X2, and is fitted into the square hole 41a of the sub valve 4. That is, the worm wheel 54 is connected to the sub-valve 4 through the square hole 41a and the cam portion 54b. Thereby, the sub-valve 4 and the worm wheel 54 are integrated and cooperatively rotate around the center shaft 6.

As shown in fig. 2, the first coil spring 55 is a tension coil spring provided between the magnetic rotor 51a and the rotation support portion 53 disposed on one side A1 of the 2 rotation support portions 53. The first coil spring 55 is disposed so as to circumferentially surround the first reduced diameter portion 52b of the worm 52, and the end portion of one side A1 is in contact with the magnetic rotor 51a and the end portion of the other side A2 is in contact with the end surface of the inner ring 53a of the rotation support portion 53. The first coil spring 55 biases the worm 52 to one side A1 (axial side).

As shown in fig. 1, the second coil spring 56 is a compression coil spring disposed between the worm wheel 54 and the sub-valve 4. The second coil spring 56 is disposed so as to circumferentially surround the boss portion 41 of the sub-valve 4, and the end portion of the upper side X1 is in contact with the worm wheel 54 and the end portion of the lower side X2 is in contact with the flange portion 40 of the sub-valve 4. The second coil spring 56 biases the sub-valve 4 toward the lower side X2, that is, the main valve 3.

The central axis 6 is a main axis extending in the direction of the axis X. As shown in fig. 1, the center shaft 6 includes: an upper portion 6a which is inserted through a center portion of the worm wheel 52 and the shaft insertion hole 4a of the sub valve 4; and a lower portion 6b formed smaller in diameter than the upper portion 6a and inserted into the shaft insertion hole 3a of the main valve 3. The upper end of the upper portion 6a is fixed with a ball 6c by caulking an annular rim, and the upper portion 6a is supported by a bearing groove provided in the center of the top wall of the second cylindrical portion 11 of the valve body 1 via the ball 6 c. The lower end of the lower portion 6b is supported by a bearing groove provided in the center of the valve seat portion 20 of the valve seat member 2. A washer 61 is fitted in a continuous portion between the upper portion 6a and the lower portion 6b, and a force generated when the main valve 3 is lifted up to the upper side X1 is transmitted to the center shaft 6 via the washer 61.

Next, switching of the flow path by the main valve 3, that is, switching operation of the valve ports 20D, 20S, 20C, 20E will be described. First, as shown in fig. 8 (a), the state in which the main valve 3 is in the first switching position in which the low-pressure flow path 30L of the main valve 3 communicates the E-switching port 20E with the S-port 20S and the high-pressure flow path 30H communicates the D-port 20D with the C-switching port 20C is set to the initial state, and the driving unit 5 operates from this state. Then, the magnetic rotor 51a rotates and the worm 52 rotates in the first direction about the axis a. Then, as the worm 52 rotates, the worm wheel 54 engaged with the worm 52 rotates in the left direction around the center axis 6, that is, in the counterclockwise direction D1. At this time, the rotational force of the worm 52 and the worm wheel 54 is transmitted to the sub-valve 4 via the cam portion 54b, and the sub-valve 4 also rotates in the counterclockwise direction D1.

At this time, since the lower surface of the sub-valve protrusion 42a is in contact with the upper surface of the main valve protrusion 33a as shown in fig. 1, the pressure equalizing hole 30a that opens in the main valve protrusion 33a is closed by the sub-valve protrusion 42 a. Therefore, even if the sub-valve 4 rotates, the main valve 3 is not rotated by friction with the valve seat 20, and only the sub-valve 4 rotates, while the main valve 3 is pressed against the valve seat 20 by the internal and external pressure difference.

When the sub-valve 4 rotates, the sub-valve protrusion 42a slides on the main valve protrusion 33a, and the pressure equalizing hole 30a opens through the pressure equalizing flow path formed on the lower surface of the flange 40 of the sub-valve 4. Thereby, the pressure of the fluid on the upper side X1 outside the main valve 3 is released into the low pressure flow path 30L (low pressure side). The main valve boss 33a is moved to a position between the pair of sub-valve bosses 42a, and the main valve boss 33a and the pair of sub-valve bosses 42a are engaged with each other differently. In this state, since the pressure in the upper side X1 of the main valve 3 and the low pressure flow path 30L is equalized, the force pressing the main valve 3 against the valve seat portion 20 is reduced as described above, and the friction force between the main valve 3 and the valve seat portion 20 is smaller than the force with which the main valve convex portion 33a engages with the pair of sub-valve convex portions 42 a.

Therefore, by rotating the sub-valve 4 about the axis X, the main valve protrusion 33a and the sub-valve protrusion 42a are integrally rotated in the counterclockwise direction D1 while abutting against each other. Thus, as shown in fig. 8 (B), the main valve 3 moves to the second switching position where the low-pressure flow path 30L communicates the C-switching port 20C with the S-port 20S, and the high-pressure flow path 30H communicates the D-port 20D with the E-switching port 20E. At this time, as shown in fig. 3, the wall of the high-pressure flow path 30H abuts against the main valve stopper 9, and the main valve 3 is further restricted from rotating about the axis X, and the rotation is stopped.

When the sub valve 4 is further rotated about the axis X in this state, only the sub valve 4, which is not restricted in rotation, is rotated in the counterclockwise direction D1 until it abuts against the sub valve stopper 31a1 described above, as shown in fig. 3. Thereby, the sub-valve protrusion 42a rides over the main valve protrusion 33a, and the pressure equalizing hole 30a is closed by the lower surface of the sub-valve protrusion 42 a. Therefore, the high-pressure fluid cannot escape from the pressure equalizing hole 30a to the low-pressure flow path 30L, and therefore the upper side X1 of the outside of the main valve 3 becomes high pressure, and the main valve 3 is pressed against the valve seat portion 20 by the pressure difference between the upper side X1 of the main valve 3 and the low-pressure flow path 30L. This completes the switching operation of the valve ports 20D, 20S, 20C, 20E by the main valve 3. In this way, in the rotary switching valve 100 as the valve device, the rotation of the sub-valve 4 rotationally driven by the driving portion 5 is transmitted to the main valve 3, thereby switching the valve ports 20D, 20S, 20C, 20E.

In the present embodiment, as shown in fig. 8 (a), the state in which the main valve 3 is in the first switching position is set to the initial state, but in contrast, as shown in fig. 8 (B), when the switching operation of the valve ports 20D, 20S, 20C, and 20E is performed from the state in which the main valve 3 is in the second switching position, the main valve 3 is set to the initial state in which the low-pressure flow path 30L of the main valve 3 communicates the C switching port 20C with the S port 20S and the high-pressure flow path 30H communicates the D port 20D with the E switching port 20E, and the main valve 3 and the sub valve 4 are rotated in the clockwise direction (not shown) opposite to the counterclockwise direction D1 by reversing the rotation direction of the worm 52 from the above description.

As shown in fig. 3, in a state where the main valve 3 is restricted from rotating (stopped from rotating) by the main valve stopper 9 and the sub valve 4 is restricted from rotating by the sub valve stopper 31A1, as shown in fig. 4, a second gap S2 (axial gap) is generated between the first step portion 52c (step portion) or the second step portion 52f (step portion) of the worm 52 and the end surface of the inner ring 53a of the rotation support portion 53 (between the second step portion 52f and the end surface of the inner ring 53a of the rotation support portion 53 arranged on the other side A2 in fig. 4), in the axis a direction. Therefore, even in a state where the main valve 3 is restricted from rotating by the main valve stopper 9, the worm 52 can be displaced by the above-described first gap S1 in the radial direction Y, and can be displaced by the second gap S2 in the axis a direction.

Here, in either case when the main valve 3 and the sub-valve 4 are rotated in the counterclockwise direction D1 and the clockwise direction, a rotation signal may be further transmitted to the electric motor 51 in a state where the rotation of the main valve 3 and the sub-valve 4 is stopped. This is because, as described above, the maximum rotation amount of the sub-valve 4 about the center axis 6 with respect to the valve main body 1 is about 210 °, and in theory, even if the sub-valve 4 rotates by the maximum rotation amount of 1400 pulses, the electric motor 51 is applied with pulses of 1400 pulses or more, so that the diameter-enlarged portion 40a of the sub-valve 4 is reliably brought into contact with the sub-valve stopper 31a1.

That is, in the rotary switching valve 100, for example, backlash at the meshing portion of the worm 52 and the worm wheel 54, clearance between the center shaft 6 and the main valve 3 and the sub-valve 4, and if the clearance or other reasons are considered, the sub-valve 4 is reliably rotated by the maximum rotation amount, and the main valve 3 is brought into contact with the main valve stopper 9, and the sub-valve 4 is brought into contact with the sub-valve stopper 31a1 of the main valve 3, a pulse of 1400 pulses+α (for example, 1500 pulses) is transmitted as a rotation signal, and thus the sub-valve 4 can be reliably rotated by the maximum rotation amount.

In this case, in a state where the rotation of the sub valve 4 is stopped, that is, in a state where the rotation of the worm wheel 54 is restricted, the worm 52 further rotates, and therefore, as shown by an arrow toward the other side A2 in fig. 5, a force (thrust) in the direction of the axis a is applied to the worm 52, and the worm 52 is intended to move in the same direction. At this time, as shown in fig. 4, in the present embodiment, the worm 52 is movable in the direction of the axis a by providing the second gap S2 between the second step portion 52f and the end surface of the inner ring 53a of the rotation support portion 53.

Further, as shown in fig. 5, the worm 52 thus moved is brought into contact with the end surface of the inner ring 53a to restrict the movement in the axis a direction, but here, when a rotational force is further applied to the worm 52, the worm 52 slides into the meshing portion with the worm wheel 54 as shown by an arrow directed in the radial direction Y in fig. 5. At this time, in the structure in which the worm 52 is in contact with the worm support portion as in the prior art, a reaction force is generated between the meshing portion and the end surface S3 of the inner ring 53a, and the worm 52 is inserted, and friction force is generated in the meshing portion and the worm support portion, respectively, so that a phenomenon occurs in which the worm 52 cannot be reversed, such that the worm is locked.

However, in the present embodiment, the worm 52 is rotatable about the axis a via the rolling member 53c after abutting against the inner ring 53 a. The first gap S1 can be displaced in the radial direction Y by the amount described above, and can slide along the inner peripheral surface of the inner ring 53 a. Therefore, the above-described slipping of the worm 52 into the engagement portion can be avoided, and thus the worm can be prevented from locking. Thus, the rotation support portion 53 (bearing) has a lock prevention mechanism that prevents the worm 52 from being locked.

Next, a refrigeration cycle system using the rotary switching valve 100 as a flow path switching valve will be described. Fig. 8 (a) and (B) are diagrams showing a refrigeration cycle system according to an embodiment, and are examples of the refrigeration cycle system of an air conditioner. The air conditioner includes a compressor P, an outdoor heat exchanger 60 (condenser or evaporator), an expansion valve 70, an indoor heat exchanger 80 (condenser or evaporator), and a rotary switching valve 100 as a flow path switching valve, and these elements are connected to each other by pipes as shown in the drawing, so that a heat pump type refrigeration cycle system is constituted.

The flow path of the refrigeration cycle is switched to 2 flow paths, i.e., the cooling operation and the heating operation, by rotating the main valve 3 of the rotary switching valve 100 as described above. In the cooling operation of fig. 8 (a), in the rotary switching valve 100, the S port 20S is connected to the E switching port 20E through the low pressure flow path 30L of the main valve 3, and the D port 20D is connected to the C switching port 20C through the high pressure flow path 30H. As indicated by an arrow in the figure, the refrigerant compressed by the compressor P as a fluid flows into the D port 20D of the rotary switching valve 100, flows into the outdoor heat exchanger 60 from the C switching port 20C, and flows out of the outdoor heat exchanger 60 into the expansion valve 70. Then, the refrigerant expands in the expansion valve 70, and is supplied to the indoor heat exchanger 80. The refrigerant flowing out of the indoor heat exchanger 80 flows from the E switching port 20E to the S port 20S in the rotary switching valve 100, and circulates from the S port 20S to the compressor P.

In the heating operation of fig. 8 (B), in the rotary switching valve 100, the S port 20S is connected to the C switching port 20C through the low pressure flow path 30L of the main valve 3, and the D port 20D is connected to the E switching port 20E through the high pressure flow path 30H. As indicated by an arrow in the figure, the refrigerant compressed by the compressor P flows into the D port 20D of the rotary switching valve 100, flows into the indoor heat exchanger 80 from the E switching port 20E, and flows out of the indoor heat exchanger 80 into the expansion valve 70. Then, the refrigerant is expanded in the expansion valve 70, and is supplied to the outdoor heat exchanger 60. The refrigerant flowing out of the outdoor heat exchanger 60 flows from the C-switching port 20C to the S-port 20S in the rotary switching valve 100, and circulates from the S-port 20S to the compressor P.

As described above, according to the present embodiment, the worm 52 is supported rotatably about the axis a (about the shaft) and movable in the direction of the axis a (axial direction) by the rotation support portion 53 having the lock prevention mechanism. Therefore, if the electric motor 51 (electric motor) continues to rotate after the rotation of the main valve 3 (valve body) is stopped, if the electric motor 51 (electric motor) receives a signal that is still rotating in the rotation direction, even if the worm 52 moves in the direction of the axis a and contacts the rotation support 53, the penetration of the worm 52, the friction force of the meshing portion between the worm 52 and the worm wheel 54, and the friction force of the worm 52 and the rotation support 53 are reduced by preventing the locked worm 52 from rotating around the axis a, or the like. Therefore, by reducing friction between the worm 52 and the portion supporting the worm 52, the worm lock can be prevented, and the rotary switching valve 100 (valve device) can be obtained in which the stability of the switching operation of the valve ports 20D, 20S, 20C, and 20E of the main valve 3 (valve element) can be improved.

Further, since the rotation support portion 53 is formed of a bearing, the bearing forms a lock prevention mechanism, and the movement of the worm 52 in the direction of the axis a can be restricted by the end surface of the bearing while preventing the worm from being locked.

After the rotation of the main valve 3 is stopped, if the electric motor 51 continues to rotate by receiving a signal that is still rotating in the rotation direction, the worm 52 can be displaced by the first gap S1 (the gap in the radial direction Y) and slide along the inner diameter of the rotation support 53 even if the worm 52 moves in the thrust direction as the axis a direction and abuts against the end surface of the rotation support 53. Therefore, the worm 52 can be prevented from extending between the engagement portion and the rotation support portion 53 due to displacement or sliding of the worm 52, and friction generated in the engagement portion or the rotation support portion 53 can be reduced.

In addition, since the second gap S2 (axial gap) is provided between the first stepped portion 52c (stepped portion) or the second stepped portion 52f (stepped portion) of the worm 52 and the end surface of the inner ring 53a (end surface of the bearing) of the rotation support portion 53 in a state where the rotation of the main valve 3 (valve body) is stopped, the worm 52 can move in the axis a direction if the electric motor 51 continues to rotate by receiving a signal that is still rotating in the rotation direction after the rotation of the main valve 3 is stopped. In addition, in this way, when the worm 52 moves in the direction of the axis a and comes into contact with the rotation support portion 53, the worm 52 can be moved by the above-described second gap S2 by reversing the worm 52. Therefore, friction force generated in the meshing portion can be reduced, and the worm can be easily prevented from locking.

Further, since the rotation support portion 53 can be a bearing constituted by a ball bearing (bearing) including the inner ring 53a, the outer ring 53b, and the rolling members 53c, the worm can be prevented from being locked by the bearing constituted by the ball bearing.

Further, since the worm 52 can be supported by the rotation support portions 53 disposed on the one side A1 and the other side A2 of the worm 52, the rotation support portions 53 disposed on both end sides of the worm 52 in the axis a direction can suppress the worm 52 from vibrating in the direction intersecting the axis a direction.

In addition, as described above, by providing the first gap S1 and the second gap S2, when the worm 52 is inserted into the rotation support portion 53 to assemble the rotary switching valve 100, the assembly can be easily performed as compared with a structure without the gap.

Although the embodiments of the present invention have been described in detail with reference to the drawings, specific configurations are not limited to these embodiments, and design changes and the like that do not depart from the gist of the present invention are also included in the present invention. Fig. 6 is a diagram showing the rotation support portion 53 in the first modification. In this modification, the above-described rotation support portion 53 is different from the present embodiment in that it is constituted by a cylindrical bush 57. That is, although the rotation support portion 53 in the above-described embodiment is constituted by a ball bearing, that is, a rolling bearing, in the first modification, the rotation support portion 53 is constituted by a sliding bearing. The bushings 57 are made of a material having low sliding resistance (low friction coefficient) and are disposed on one side A1 and the other side A2 of the worm 52, respectively. Specific materials of the bushing 57 include sintered metal containing a solid lubricant, a high-strength resin material, and a material obtained by coating a metal material with a coating agent having a low friction coefficient. A first gap S1 is provided between the inner peripheral surface of the bush 57 and the first and second reduced diameter portions 52b and 52g of the worm 52, as in the present embodiment. In addition, in a state where the main valve 3 is restricted from rotating by the main valve stopper 9 and the sub valve 4 is restricted from rotating by the sub valve stopper 31A1, a second gap S2 (axial gap) is generated between the first step portion 52c (step portion) or the second step portion 52f (step portion) of the worm 52 and the end surface of the bush 57 (in fig. 6, between the second step portion 52f and the end surface of one side A1 of the bush 57 arranged on the other side A2 of the 2 bushes 57) in the axis a direction. According to this configuration, as in the present embodiment, friction between the worm 52 and the portion supporting the worm 52 is reduced, so that the worm is prevented from locking, and the rotary switching valve 100 (valve device) can be obtained in which the stability of the switching operation of the main valve 3 (valve element) to the valve ports 20D, 20S, 20C, and 20E is improved.

Fig. 7 is a diagram showing the driving unit 5 and the worm 52 in the second modification. In the second modification, the urging force of the first coil spring 55 (indicated by an arrow toward one side A1 in fig. 7) is set to be larger than the urging force (indicated by an arrow toward the other side A2 in fig. 7) acting on the worm 52 toward the other side A2 of the worm 52 by engagement of the worm 52 with the worm wheel 54, which is different from the above-described embodiment and the first modification. According to this configuration, even if the worm 52 moves toward the other side A2, for example, by continuing the rotation of the electric motor 51 by the rotation signal in the rotation direction after the rotation of the main valve 3 is stopped, the movement of the worm 52 can be suppressed by the first coil spring 55 having a force larger than the thrust force acting on the worm 52 toward the other side A2. In this case, the main function of the rotation support portion 53 provided on the other side A2 of the 2 rotation support portions 53 is to prevent vibration in a direction intersecting the axis a direction of the worm 52, and thus, from the viewpoint of preventing the worm from locking, it can be omitted.

In the above-described embodiment and modification, the valve device was described as the rotary switching valve 100, but the valve device may be a device other than the rotary switching valve 100. For example, the present invention can be applied to an electric flow path control valve as follows: the valve body driven by the electric motor and the worm gear is moved in an axial direction (i.e., up-down direction) of a central shaft perpendicular to the valve seat surface with respect to the valve seat surface to open and close the valve opening, and rotation of the valve body is stopped by a stopper provided in the valve body. In addition, similarly, the present invention can be applied to a flow path opening/closing valve of an electric ball valve for switching each flow path by rotationally driving a ball valve having a plurality of flow paths opening in the radial direction of a central shaft in the horizontal direction. In addition, the present invention can be similarly applied to an electric rotary expansion valve including: a valve seat plate having a groove portion extending around a central axis and having a groove width gradually varying; and a valve element having a slit matching the groove portion, the throttle flow rate being controlled in accordance with rotational displacement of the valve element about the center axis.

In the present embodiment, ball bearings, which are ball bearings, are used as the rotation support portion 53, but bearings such as roller bearings in which the rolling members 53c are roller-shaped members may be used as the rotation support portion 53, not limited to ball bearings.

In the present embodiment, the rotary switching valve 100 of the type in which the main valve 3 is restricted from rotating by the main valve stopper 9 is described, but the portion in which the rotation of the main valve 3 is restricted is not necessarily limited to the main valve stopper 9. For example, the present invention can be applied to the rotary switching valve 100 having the following structure: a stopper protruding from the top of the valve body 1 to the lower side X2 is provided, and a stopper protruding from the upper surface of the worm wheel 54 to the upper side X1 is provided, and the rotation of the worm wheel 54 is restricted by abutting the stoppers to each other, thereby restricting the rotation of the sub-valve 4, and thereby restricting the rotation of the main valve 3.

Claims

1. A valve device comprising a valve body, and a driving unit, wherein the valve body is rotationally driven by the driving unit, and the valve body is stopped from rotating by a stopper of the valve body,

the driving unit includes: a worm rotated by an electric motor; and a worm wheel engaged with the worm,

The worm is supported by a rotation support part of at least 1 part to be rotatable around a shaft and movable along an axial direction,

the rotation support portion has a lock prevention mechanism that prevents locking of the worm.

2. A valve device according to claim 1, wherein,

the lock prevention mechanism is configured by a bearing provided on the rotation support portion, and restricts movement in the axial direction of the worm by abutting against an end surface of the bearing.

3. A valve device according to claim 2, wherein,

a radial gap is provided between the worm and the inner diameter of the bearing.

4. A valve device according to claim 3, wherein,

the worm has a shaft portion, a stepped portion, and a reduced diameter portion inserted through the bearing,

an axial gap is provided between the stepped portion and an end surface of the bearing in a state where rotation of the valve body is stopped.

5. A valve device according to claim 4, wherein,

the bearing is a bearing having an inner ring, an outer ring, and rolling members, and is configured to regulate movement of the worm in the axial direction by abutting an end surface of the inner ring.

6. A valve device according to claim 4, wherein,

The bearing is a bush having a low sliding resistance and formed in a cylindrical shape.

7. A valve device according to claim 1, wherein,

the rotation support portion is disposed on a side of the worm in the axial direction, that is, on a side on which the electric motor is located.

8. A valve device according to claim 7, wherein,

the driving part is provided with a force application component for applying force to one side of the axial direction of the worm,

the force applied by the force applying member is greater than an axial force, i.e., a thrust force, which acts on the worm shaft toward the other axial side of the worm shaft by meshing with the worm wheel.

9. A valve device according to claim 7, wherein,

the rotation support portion is also disposed on the other axial side of the worm.

10. A rotary switching valve is characterized in that,

the rotary switching valve as the valve device according to any one of claims 1 to 9,

the valve device is provided with: a valve chamber provided in the valve main body; a valve seat portion having a plurality of valve ports that open to the valve chamber; a main valve rotatably provided inside the valve main body around a central axis intersecting the valve seat portion; and a sub-valve rotatably provided around the central axis to open and close the pressure equalizing hole of the main valve,

The valve port is switched by rotation of the sub-valve rotationally driven by the driving unit being transmitted to the main valve.