CN114811112A

CN114811112A - Flow control valve

Info

Publication number: CN114811112A
Application number: CN202210007793.4A
Authority: CN
Inventors: 菱谷康平
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2021-01-28
Filing date: 2022-01-05
Publication date: 2022-07-29
Also published as: JP7320853B2; JP2022115501A

Abstract

The invention provides a flow control valve which can restrain the backflow of fluid and can perform high-precision flow control. The flow control valve has: a valve body having a valve seat provided with a first orifice and a second orifice; and a rotary valve body that includes a first valve body and a second valve body held so as to be movable in a direction of contacting with and separating from the valve seat, and that rotates so that a contact position of the first valve body and the second valve body with the valve seat changes, the rotary valve body having a first rotational position at which the first valve body overlaps with the first orifice and the second valve body overlaps with the second orifice when viewed in a direction along a rotational axis of the rotary valve body.

Description

Flow control valve

Technical Field

The present invention relates to a flow control valve.

Background

In general, in a heat pump type cooling and heating system or the like, a rotary flow path switching valve that switches a flow path by rotating a valve body is provided as a flow path control valve.

As such a flow path switching valve, there is a four-way switching valve shown in patent document 1. The four-way switching valve of patent document 1 has a rotary valve body disposed in a main valve housing, and by introducing a high-pressure refrigerant into the main valve housing and introducing a low-pressure refrigerant into a flow path in the rotary valve body, a valve seat surface abutting against the valve seat surface of the rotary valve body is pressed to ensure sealing performance.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-194032

Technical problem to be solved by the invention

However, when a rotary valve body is used in addition to a switching valve that alternately switches between high pressure and low pressure in two ports that are connected, it is difficult to use high-pressure refrigerant for sealing the valve body, and therefore, it is necessary to ensure sealability when the valve is closed. Further, there is a demand for accurate flow rate control from the closed valve state to the open valve state.

Disclosure of Invention

The purpose of the present invention is to provide a flow control valve capable of suppressing the backflow of a fluid and performing high-precision flow control.

Means for solving the problems

To achieve the above object, a flow rate control valve according to the present invention includes: a valve body having a valve seat provided with a first orifice and a second orifice; and a rotary valve body that includes a first valve body and a second valve body that are held so as to be movable in a direction of contacting with and separating from the valve seat, and that is rotatable so that a contact position of the first valve body and the second valve body with the valve seat changes, the rotary valve body being rotatable to a first rotational position at which the first valve body overlaps with the first orifice and the second valve body overlaps with the second orifice when viewed in a direction along a rotational axis of the rotary valve body.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a flow rate control valve capable of suppressing a reverse flow of a fluid and performing a flow rate control with high accuracy.

Drawings

Fig. 1 is a longitudinal sectional view showing a flow rate control valve according to the present embodiment.

Fig. 2 is an exploded perspective view of the planetary gear type speed reducing mechanism used in the flow rate control valve shown in fig. 1.

Fig. 3 is a perspective view showing a state in which the rotary valve body is combined with the valve seat.

Fig. 4 is a perspective view of the rotary valve body viewed from the lower surface side.

Fig. 5 is a side view showing a part of a cross section of the rotary valve body and the valve seat, and shows a valve-closed state.

Fig. 6 is a side view showing a part of a cross section of the rotary valve body and the valve seat, and shows an intermediate opening degree.

Fig. 7 is a side view showing a part of a cross section of the rotary valve body and the valve seat, and shows a fully opened state.

Fig. 8 is a graph of valve opening characteristics in which the maximum interval is plotted on the vertical axis and the rotation angle of the rotary valve body is plotted on the horizontal axis.

Description of the symbols

1 flow control valve

2 stator

5 valve chamber

8 rotor assembly

10 valve seat

14 first orifice

16 second orifice

20 first piping

22 second piping

30 outer cover

40 planetary gear type reduction mechanism (reduction part)

45 rotary valve core

Detailed Description

Hereinafter, a flow rate control valve according to an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a longitudinal sectional view showing a flow rate control valve according to the present embodiment. Fig. 2 is an exploded perspective view of the planetary gear type reduction mechanism used in the flow rate control valve shown in fig. 1, but a part of the planetary gear type reduction mechanism is shown cut away for easy understanding. In this specification, the upper side represents the drive portion side, and the lower side represents the valve seat side.

(construction of flow control valve)

The flow rate control valve 1 includes: a drive unit 11, a planetary gear type reduction mechanism (hereinafter referred to as "reduction unit") 40 that performs gear reduction by inputting a rotational drive force from the drive unit 11, a valve seat 10, and a housing 30. The axis of the flow control valve 1 is denoted as L.

The housing 30 is an airtight container fixedly attached to the valve seat 10 via a receiving member 68, and has a thin-walled, cylindrical shape with a top. The driving unit 11 includes a stator 2 and a permanent magnet type rotor assembly 8 driven to rotate by the stator 2. The stator 2 is a motor excitation device formed by integrally molding a pair of coils 140 with resin, and the pair of coils 140 are fixedly disposed on the outer peripheral portion of the housing 30 and wound around the bobbin. The rotor assembly 8 is rotatably supported inside the housing 30. A stepping motor as an example of a motor is configured by the stator 2 and the rotor assembly 8.

The stator 2 is detachably fitted into the housing 30, and is fixed to the housing 30 at a predetermined position by a fitting metal fitting 180. In this example, the dome portion 31 formed in the vicinity of the lower end of the outer case 30 is elastically fitted into the hole 182 formed in the mounting fitting 180, and thereby the stator 2 is positioned with respect to the outer case 30. To excite the stator 2, the coil 140 is supplied with power from an external power supply via a lead wire not shown.

The valve seat 10 is formed by coaxially and continuously providing a substantially disk-shaped main body 10a and a circular tube 10 b. A cylindrical first orifice 14 and a cylindrical second orifice 16 are disposed in the main body 10a in parallel with the axis L at equal distances. The first pipe 20 is connected to the body 10a so as to communicate with the first orifice 14, and the second pipe 22 is connected to the body 10a so as to communicate with the second orifice 16. The circular tube portion 10b is formed with a pair of lateral holes 18 that communicate the inner and outer peripheries.

A stepped portion 13 is formed on the outer periphery of the valve seat 10, and the inner periphery of the receiving member 68 abuts and is fitted to the stepped portion 13. Thereby, the positioning of the valve seat 10 in the direction of the axis L of the housing 30 is achieved. A valve chamber 5 is formed between the valve seat 10 and the housing 30.

As shown in fig. 2, the speed reducer 40 includes: a sun gear 41 integrated with the rotor assembly 8, a plurality of (three in this example) axially long pinion gears 43 rotatably supported by a carrier 42 formed by, for example, plastic molding and meshing with the sun gear 41, a ring gear 44 disposed concentrically with the sun gear and meshing with a part (upper part) of each pinion gear 43, and a rotary valve body 45 having an output gear portion 45a formed on an inner periphery thereof with internal teeth having a slightly different number of teeth from that of the ring gear 44 (that is, having a displacement relationship with the ring gear 44). The sun gear 41, the carrier 42, the ring gear 44, and the rotary valve body 45 are preferably formed of PPS (polyphenylene sulfide resin).

As is apparent from fig. 2, each of the pinion gears 43 meshes with the ring gear 44, and a part (lower side part) thereof meshes with the output gear part 45a of the rotary valve body 45.

The rotor assembly 8 is formed in a top cylindrical shape by integrally molding a cylindrical body 202 as a peripheral wall and a sun gear member 204 disposed at the center thereof with a plastic material (PPS in this case) containing a magnetic material. The rotor assembly 8 is rotatably supported inside the housing 30 by a shaft 201 (fig. 1) that penetrates the sun gear member 204 in the axial direction.

As shown in fig. 2, a sun gear 41 is formed on the outer periphery of a cylinder implanted in the center of the sun gear member 204. The ring gear 44 is an annular gear formed by molding plastic, for example.

According to such a configuration, when the sun gear 41, to which the output rotation of the motor is input, rotates, the planetary gear 43 meshing with the sun gear 41 and the ring gear 44 revolves around the sun gear 41 while rotating on its axis. Since the planetary gear 43 meshes with the rotary valve body 45, and the rotary valve body 45 is in a displaced relationship due to the relationship with the ring gear 44, the rotary valve body 45 rotates at a relatively very high reduction ratio of, for example, 50 to 1 or so with respect to the ring gear 44 by the rotation of the planetary gear 43 according to the degree of displacement (difference in the number of teeth). The planetary gear mechanism in which the planetary gear 43 meshes with the ring gear 44 and the output gear portion 45a that are in a displaced relationship is referred to as a differential gear mechanism.

The carrier 42 includes a lower disc 42b and an annular plate 42c, in which three column portions 42a are implanted in parallel on the outer periphery of the upper surface, and the lower disc 42b and the plate 42c are fixed in parallel via the column portions 42 a. The lower disc 42b includes a fitting hole 42h into which the shaft 201 is rotatably fitted.

On the other hand, between circumferentially adjacent column parts 42a, both ends of the planetary gear 43 made of a zinc alloy are rotatably held by the lower disc 42b and the plate 42c, whereby the planetary gear 43 can rotate relative to the carrier 42.

Fig. 3 is a perspective view showing a state in which the rotary valve body 45 is combined with the valve seat 10, and shows the rotary valve body 45 sectioned by a plane along the axis.

In fig. 1 and 3, the rotary valve body 45 has a substantially cylindrical shape which is hollow on the upper side and solid on the lower side. Specifically, the rotary valve body 45 includes: the output gear portion 45a, the pocket hole 45b formed in the bottom surface of the hollow cylinder, the first communication hole 45c and the second communication hole 45d arranged in parallel in the vertical direction, the

pressure equalizing holes

45e and 45f formed so as to communicate with the first communication hole 45c and the second communication hole 45d, respectively, from the outer periphery of the rotary valve body 45, and the small cylinder portion 45g formed in the center of the lower surface. The lower end of the shaft 201 is fitted into the pocket hole 45b so as to be relatively rotatable.

On the lower end sides of the first communication hole 45c and the second communication hole 45d, diameter-expanded

cylindrical portions

45h and 45i are formed, respectively, and

coil springs

51 and 53 are disposed inside the diameter-expanded

cylindrical portions

45h and 45 i. As shown in fig. 1, the diameter-enlarged

cylindrical portions

45h and 45i are disposed coaxially with the first orifice 14 and the second orifice 16 of the valve seat 10, respectively. The coil spring 51 constitutes a first urging member that urges the ball 55 toward the valve seat 10, and the coil spring 53 constitutes a second urging member that urges the ball 57 toward the valve seat 10.

Fig. 4 is a perspective view of the rotary valve body 45 as viewed from the lower surface side. As shown in fig. 4, a spiral surface 45j is formed on the rotary valve body 45, and the spiral surface 45j is displaced toward the upper end side in the circumferential direction around the small cylindrical portion 45 g. A flat surface 45k orthogonal to the axis L is formed so as to be continuous with the spiral surface 45j around the diameter-enlarged cylindrical portion 45 h.

As shown in fig. 3, the small cylindrical portion 45g of the rotary valve body 45 is rotatably fitted into an engagement hole 17 formed in an upper surface (a plane orthogonal to the axis L) 19 of the main body 10a of the valve seat 10. The spiral surface 45j constitutes a tapered surface inclined with respect to the upper surface 19.

As shown in fig. 1, in a state where the flat surface 45k of the rotary valve body 45 abuts against the upper surface 19 of the main body 10a of the valve seat 10, the ball 55 is disposed between the coil spring 51 of the diameter-enlarged cylindrical portion 45h and the first orifice 14, and the ball 57 is disposed between the coil spring 53 of the diameter-enlarged cylindrical portion 45i and the second orifice 16. The diameter of the diameter-expanded cylindrical portion 45h is the same as that of the spherical body 55, and the diameter of the diameter-expanded cylindrical portion 45i is the same as that of the spherical body 57. The ball 55 constitutes a first valve spool and the ball 57 constitutes a second valve spool. The valve body is not limited to a sphere, and may be a cylinder having a tip formed in a hemispherical shape, a truncated cone shape, or the like. Further, by using both the first valve element and the second valve element, which are held so as to be movable in the direction of contact with and separation from the valve seat 10, as balls, the amount of leakage at the time of closing the valve can be reduced in both the forward and reverse flow directions.

In fig. 1, the outer periphery of the lower end side of the rotary valve body 45 is fitted into the circular tube portion 10b of the valve seat 10, and the outer periphery of the upper end of the circular tube portion 10b and the outer periphery of the ring gear 44 are connected by a gear housing 220 which is a thin cylindrical member. Therefore, the rotary valve body 45 and the valve seat 10 are relatively rotatable without being separated in the direction of the axis L, and the contact positions of the

balls

55 and 57 and the valve seat 10 are changed by the relative rotation.

(operation of flow control valve)

The operation of the flow rate control valve 1 of the present embodiment will be described with reference to fig. 5 to 8. The first pipe 20 and the second pipe 22 are connected to the refrigeration cycle.

(when closing the valve)

First, in a state where power is not supplied from the external power supply, the rotation angle of the rotor assembly 8 is zero, and the valve-closed state shown in fig. 1 and 5 is achieved. The rotational position of the rotary valve body 45 in the valve-closed state is set to the first rotational position, and the rotational angle of the rotary valve body 45 in the valve-opened state (other than the valve-closed state) is set to the second rotational position. In the first rotational position, the ball 55 coincides with the first orifice 14 and the ball 57 coincides with the second orifice 16, as viewed in a direction along the rotational axis of the rotary valve spool 45.

At this time, the ball 55 is positioned at the upper end of the first orifice 14 to close the first orifice 14, and the ball 57 is positioned at the upper end of the second orifice 16 to close the second orifice 16. Therefore, for example, when the first pipe 20 side is set to a high pressure and the second pipe 22 side is set to a low pressure, the pressure on the first pipe 20 side exceeds the biasing force of the coil spring 51, and the ball 55 may be separated from the first orifice 14.

In this case, the refrigerant (fluid) that has entered the valve chamber 5 from the first pipe 20 through the first orifice 14 reaches the second communication hole 45d through the gap between the horizontal hole 18 and the circular tube portion 10b and the rotary valve body 45 and the pressure equalizing hole 45 f. At this time, the pressure in the second communication hole 45d becomes higher than the pressure in the second orifice 16 sandwiching the ball 57, and therefore, the ball 57 is biased toward the second orifice 16, thereby preventing the flow of the refrigerant from the first pipe 20 toward the second pipe 22.

On the other hand, when the pressure on the second pipe 22 side is set to a high pressure and the pressure on the first pipe 20 side is set to a low pressure, the pressure on the second pipe 22 side exceeds the biasing force of the coil spring 53, and the ball 57 may be separated from the second orifice 16.

In this case, the refrigerant that has entered the valve chamber 5 from the second pipe 22 through the second orifice 16 reaches the first communication hole 45c through the gap between the horizontal hole 18 and the circular tube portion 10b and the rotary valve body 45 and the pressure equalizing hole 45 e. At this time, the pressure in the first communication hole 45c becomes higher than the pressure in the first orifice 14 sandwiching the ball 55, and therefore, the ball 55 is biased toward the first orifice 14, thereby preventing the flow of the refrigerant from the second pipe 22 toward the first pipe 20.

As described above, even when either of the first pipe 20 and the second pipe 22 is at a high pressure during valve closing, the

spheres

55 and 57 can be made check valves to prevent the refrigerant from flowing from the high-pressure side pipe to the low-pressure side pipe. Therefore, even when the coil springs 51 and 53 having a weak biasing force are used, the check valve effect can be exhibited, and therefore, compared to the case where the coil springs having a strong biasing force are used, it is not necessary to secure the strength of each member, and the operability can be improved.

(when opening the valve)

Then, when power is supplied from an external power supply in accordance with a control signal, the stator 2 generates a magnetic force. The rotor assembly 8 is driven to rotate by an angle corresponding to the magnetic force, thereby generating a rotational force in a predetermined direction. The rotational force is transmitted to the sun gear 41, is decelerated by the deceleration unit 40, and is transmitted to the output gear unit 45a, so that the rotary valve body 45 rotates about the axis L.

Then, as shown in fig. 6, the ball 55 moves away from the upper end of the first orifice 14 toward the upper surface 19 of the valve seat 10. At this time, the upper end of the first orifice 14 faces the spiral surface 45j of the rotary valve body 45. Although not shown, the ball 57 is also separated from the upper end of the second orifice 16 and moves toward the upper surface 19 of the valve seat 10, and therefore the upper end of the second orifice 16 also faces the spiral surface 45j of the rotary valve body 45. In other words, when the rotary valve body 45 is rotated to a rotational position different from the first rotational position, the ball 55 moves from the first orifice 14 onto the upper surface 19, and the ball 57 moves from the second orifice 16 onto the upper surface 19. Fig. 7 shows the fully open state in which the rotary valve element 45 is rotated at the maximum angle.

As shown in fig. 6 and 7, when the rotary valve body 45 rotates, a gap corresponding to the rotation angle of the rotary valve body 45 is formed between the upper surface 19 of the valve seat 10 and the spiral surface 45j, and therefore, the refrigerant flows from one of the first orifice 14 and the second orifice 16 to the other through the gap.

For example, when the first pipe 20 side is set to the high pressure side and the second pipe 22 side is set to the low pressure side, the refrigerant that has entered the flow rate control valve 1 from the first pipe 20 through the first orifice 14 passes through the gap between the upper surface 19 of the valve seat 10 and the spiral surface 45j, passes through the lateral hole 18, and reaches the valve chamber 5. Further, the refrigerant passes through the transverse hole 18 on the opposite side from the valve chamber 5, passes through the gap between the upper surface 19 of the valve seat 10 and the spiral surface 45j, and reaches the second pipe 22 via the second orifice 16. When the first pipe 20 side is a low-pressure side and the second pipe 22 side is a high-pressure side, the refrigerant flows in the opposite direction to the above.

Here, when the maximum distance H between the upper surface 19 near the first orifice 14 and the spiral surface 45j of the rotary valve body 45 is made smaller than the distance between the upper surface 19 near the second orifice 16 and the spiral surface 45j of the rotary valve body 45, the amount of refrigerant flowing between the first orifice 14 and the second orifice 16 is controlled by the size of the maximum distance H.

The maximum distance H between the upper surface 19 in the vicinity of the first orifice 14 and the spiral surface 45j of the rotary valve body 45 changes depending on the amount of rotation of the rotary valve body 45 and the spiral angle of the spiral surface 45 j.

Fig. 8 is a graph of the valve opening characteristics with the maximum interval H on the vertical axis and the rotation angle of the rotary valve body 45 on the horizontal axis. In the present embodiment, since the spiral angle of the spiral surface 45j is constant, the maximum interval H changes linearly with the rotation angle of the rotary valve body 45 as shown by a solid line a in fig. 8.

Further, by changing the spiral angle of the spiral surface 45j in accordance with the rotational position of the rotary valve body 45, it is possible to obtain the valve opening characteristics shown by the one-dot chain line B in fig. 8, in which the flow rate increases and decreases in a quadratic curve, or the broken line C, in which the flow rate rapidly increases from a predetermined angle.

On the other hand, when power is supplied from the external power supply in response to the control signal having the opposite characteristic, the rotor assembly 8 is driven to rotate in the reverse direction, and the rotary valve body 45 also rotates in the reverse direction, thereby transitioning from the valve-open state shown in fig. 6 and 7 to the valve-closed state shown in fig. 5. Thereby, the flow of the refrigerant is shut off between the first orifice 14 and the second orifice 16.

According to the present embodiment, since the rotational motion of the stepping motor is transmitted to the rotary valve body 45 via the speed reducer 40, the rotary valve body 45 can be rotated with high precision with high resolution. Therefore, the flow rate of the refrigerant can be controlled with high accuracy according to fig. 8. The present invention has been described with reference to a two-way valve, but the present invention can be similarly applied to a multi-way valve such as a three-way valve.

Claims

1. A flow control valve, comprising:

a valve body having a valve seat provided with a first orifice and a second orifice; and

a rotary valve body including a first valve body and a second valve body held so as to be movable in a direction of contacting with and separating from the valve seat, and rotating so that contact positions of the first valve body and the second valve body with the valve seat change,

the rotary valve body is rotatable to a first rotational position in which the first valve body overlaps the first orifice and the second valve body overlaps the second orifice when viewed in a direction along a rotation axis of the rotary valve body.

2. The flow control valve of claim 1,

the motor is also provided with a speed reduction part which reduces the rotation speed of the motor and rotates the rotary valve core.

3. The flow control valve according to claim 1 or 2,

the valve seat has a plane surface parallel to a plane orthogonal to the rotation axis, and the rotary valve element has a tapered surface inclined with respect to the plane surface.

4. The flow control valve according to claim 1 or 2,

the valve seat has a plane parallel to a plane orthogonal to the rotation axis,

when the rotary spool is at a rotational position different from the first rotational position, the first spool moves from the first orifice onto the plane, and the second spool moves from the second orifice onto the plane.

5. The flow control valve of claim 3,

6. The flow control valve according to any one of claims 1 to 5,

the valve device is provided with a first biasing member that is disposed in a first communication hole of the rotary valve body and biases the first valve body toward the valve seat, and a second biasing member that is disposed in a second communication hole of the rotary valve body and biases the second valve body toward the valve seat.

7. The flow control valve according to any one of claims 1 to 6,

the first and second spools are spheres.

8. The flow control valve of claim 2,

the speed reduction unit has a planetary gear, and an output gear unit engaged with the planetary gear is formed integrally with the rotary valve body.