CN113700870A

CN113700870A - Electric valve

Info

Publication number: CN113700870A
Application number: CN202110263539.6A
Authority: CN
Inventors: 菱谷康平
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2020-05-21
Filing date: 2021-03-11
Publication date: 2021-11-26
Also published as: JP7138953B2; JP2021183852A

Abstract

The invention provides an electric valve capable of inhibiting deformation of a contact part of a valve core and a spring supporting component. The electrically operated valve (1) has a valve holder (41) connected to the valve shaft (34). A cylindrical valve element (30) is supported by a valve holder (41) so as to be movable in the vertical direction. The lower end (30a) of the valve element (30) is in contact with and separated from a valve seat (19) of the valve port (17). Inside the valve holder (41), a valve closing spring (44) presses the valve body toward the lower end (30a) via a spring support member (43). A back pressure chamber (45) as a sealed space is provided inside the valve holder (41). A pressure equalizing passage (33) is provided in the valve body (30) and connects the valve port (17) and the back pressure chamber (45) in a state where the lower end (30a) is in contact with the valve seat (19).

Description

Electric valve

Technical Field

The present invention relates to an electrically operated valve.

Background

Patent document 1 discloses an example of a conventional motor-operated valve. As shown in fig. 3, the motor-operated valve 901 of patent document 1 includes a cylindrical valve main body 905 and a housing 948 welded to the valve main body 905. A guide sleeve 950 and a valve shaft 934 supported by the guide sleeve 950 so as to be movable in the vertical direction are disposed inside the valve main body 905 and the housing 948. The guide sleeve 950 is provided with female threads 951 c. The valve shaft 934 is provided with a male screw 935c that is screwed into the female screw 951 c.

A cylindrical valve holder 941 is connected to the valve shaft 934. The space inside the valve holder 941 is connected to the valve chamber 913 of the valve body 905 via a pressure equalizing hole 941 a. The valve holder 941 supports the valve body 930 to be movable in the vertical direction. The valve body 930 is in contact with and separated from a valve seat 919 disposed so as to surround the valve port 917 of the valve main body 905. A spring support member 943 and a valve closing spring 944 are disposed inside the valve holder 941. The spring support 943 contacts the valve spool 930. The valve closing spring 944 presses the valve body 930 downward via the spring support member 943. As the valve shaft 934 rotates, the spring bearing member 943 rotates about the axis L together with the valve holder 941. The rotation of the spool 930 about the axis L is restricted. The spring bearing member 943 rotationally slides with respect to the valve core 930. A first conduit 926 is connected to the valve chamber 913. A second conduit 927 is connected to the valve port 917.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 6476158

The electric valve 901 described above is sometimes used in a system in which the fluid pressure of the valve port 917 is very high compared to the fluid pressure of the valve chamber 913. In such a case, the force (force F1 in the valve opening direction) applied to the spool 930 by the fluid pressure of the valve port 917 becomes very large compared to the force (force F2 in the valve closing direction) applied to the spool 930 by the fluid pressure of the valve chamber 913. In fig. 3, a force F1 in the valve opening direction and a force F2 in the valve closing direction are schematically shown by arrows. The length of the arrow indicates the magnitude of the force. It is desirable to increase the force of the valve closing spring 944 to prevent the valve port 917 from opening due to fluid pressure.

However, in the electric valve 901, if the force of the valve closing spring 944 is increased, the spring support member 943 is strongly pressed against the valve body 930, and there is a possibility that the contact portion between the spring support member 943 and the valve body 930 is deformed. This increases the contact area between the spring support member 943 and the valve body 930, and the spring support member 943 may be difficult to rotationally slide with respect to the valve body 930. Further, the total length of the spring support member 943 and the valve body 930 becomes shorter, and the valve closing spring 944 extends and shortens by the amount corresponding to the shorter, and the valve body 930 may not be pressed with an appropriate force by the valve closing spring 944.

Disclosure of Invention

Therefore, an object of the present invention is to provide an electrically operated valve capable of suppressing deformation of a contact portion between a valve element and a spring support member.

In order to achieve the above object, a motor-operated valve according to the present invention includes: a valve body provided with a valve chamber and a valve port; a support member fixed to the valve main body; a valve shaft supported by the support member so as to be movable in an axial direction; a valve holder connected to the valve shaft and having a back pressure chamber therein; a valve body supported by the valve holder so as to be movable in the axial direction, one end of the valve body being in contact with and separated from a valve seat of the valve port; a spring support member disposed inside the valve holder so as to be in contact with the other end of the valve element; and a valve-closing spring disposed in the back pressure chamber, the valve-closing spring pressing the valve body toward one end side via the spring support member, the valve body being provided with a pressure equalizing passage connecting the valve port and the back pressure chamber in a state where one end of the valve body is in contact with the valve seat.

In the present invention, it is preferable that a closing member is disposed between the valve holder and the valve body, and a diameter of the valve port is equal to a diameter of a portion of the valve body closed by the closing member.

The motor-operated valve according to the present invention can equalize the fluid pressure at the valve port and the fluid pressure at the back pressure chamber in a state where one end of the valve element is in contact with the valve seat (i.e., a state where the valve port is closed). This prevents a very large difference between the force applied to the valve body by the fluid pressure in the valve port (force in the valve opening direction) and the force applied to the valve body by the fluid pressure in the back pressure chamber (force in the valve closing direction). Therefore, it is not necessary to increase the force of the valve closing spring, and deformation of the contact portion between the valve body and the spring support member can be suppressed.

In addition, the motor-operated valve has the following structure: by disposing the closing member between the valve holder and the valve body and making the diameter of the valve port equal to the diameter of the closed portion closed by the closing member, the difference between the force in the valve opening direction and the force in the valve closing direction can be eliminated or made very small. Therefore, it is not necessary to increase the force of the valve closing spring, and deformation of the contact portion between the valve body and the spring support member can be more effectively suppressed.

Drawings

Fig. 1 is a sectional view of an electrically operated valve according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of the electrically operated valve of fig. 1.

Fig. 3 is a cross-sectional view of a conventional motor-operated valve.

Description of the symbols

1 … electric valve, 5 … valve body, 10 … seat component, 13 … valve chamber, 17 … valve port, 19 … valve seat, 25 … cylindrical component, 25a … lower end, 25e … upper end surface, 26 … first conduit, 27 … second conduit, 30 … valve core, 30a … lower end, 30b … upper end, 31 … first portion, 31a … outer peripheral surface, 32 … second portion, 32a … lower end surface, 33 … pressure equalizing passage, 34 … valve shaft, 35 … large diameter portion, 35c … male thread, 36 … small diameter portion, 37 … disc portion, 40 … connecting mechanism, 41 … valve holder, 41a … plate component, 41b … annular projection, 41c … spacer, 42 … closing component, 42a … O-ring, 42b … gasket, 43 … spring support component, 43a … flange, 3644 spring 72, … back pressure chamber …, … guide … a … housing, … lower end guide … housing, … a … guide …, … lower end … guide …, … cover …, … guide …, … lower end portion, … guide, 51b … second stopper, 51c … female screw, 52 … cylindrical portion, 53 … flange-like disk, 60 … valve body driving portion, 61 … rotor, 61a … peripheral wall portion, 61b … upper wall portion, 62 … stator, 63 … connecting body, 64a … lower stopper, 64b … upper stopper, force in F1 … valve opening direction, force in F2 … valve closing direction

Detailed Description

An electrically operated valve according to an embodiment of the present invention will be described below with reference to fig. 1 to 2.

Fig. 1 and 2 are cross-sectional views of an electrically operated valve according to an embodiment of the present invention. Fig. 1 shows the motor-operated valve in an open state. Fig. 2 shows the motor-operated valve in a closed state. In fig. 2, the stator is not shown.

As shown in fig. 1 and 2, the motor-operated valve 1 includes a valve main body 5, a valve body 30, a valve shaft 34, a coupling mechanism 40, a housing 48, a guide sleeve 50 as a support member, and a valve body drive unit 60.

The valve main body 5 has a seat member 10 and a cylindrical member 25. A valve chamber 13 is provided inside the valve main body 5.

The seat member 10 is made of, for example, a stainless steel material. The seat member 10 has a cylindrical shape. The seat member 10 is provided with a valve port 17 and a valve seat 19. The valve port 17 is a circular hole. The valve port 17 opens into the valve chamber 13. The valve seat 19 is a conical surface of a circular ring shape. The valve seat 19 is disposed so as to surround the valve port 17.

The cylindrical member 25 is made of, for example, a stainless steel material. The seat member 10 is fitted into the lower end 25a of the cylindrical member 25. The lower end 25a of the cylindrical member 25 is closed by the seat member 10. The lower end 25a of the cylindrical member 25 is brazed to the seat member 10.

The valve body 5 has a first conduit 26 and a second conduit 27. The first conduit 26 extends through the cylindrical member 25 in the lateral direction and is connected to the valve chamber 13. The first conduit 26 is brazed to the cylindrical member 25. The second conduit 27 is connected to the port 17. The second conduit 27 is brazed to the seat member 10.

The valve body 30 is made of, for example, a stainless steel material. The spool 30 has a cylindrical shape. The spool 30 has a disc-shaped first portion 31 and a cylindrical second portion 32 provided continuously with a lower surface of the first portion 31. The diameter of the second portion 32 is smaller than the diameter of the first portion 31. The valve body 30 is provided with a pressure equalizing passage 33 extending from the outer peripheral surface 31a of the first portion 31 to the lower end surface 32a of the second portion 32. The pressure equalizing passage 33 opens in the lateral direction at the outer peripheral surface 31a of the first portion 31. The pressure equalizing passage 33 opens downward at the lower end surface 32a of the second portion 32. The lower end 30a (one end) of the valve body 30 is disposed in the valve chamber 13. The upper end 30b (the other end) of the valve body 30 is disposed in a back pressure chamber 45 described later.

The valve body 30 opens and closes the valve port 17. The valve body 30 is disposed to face the valve port 17 in the vertical direction (the direction of the axis L). The lower end 30a of the valve element 30 contacts and separates from the valve seat 19. When the lower end 30a of the valve body 30 is separated from the valve seat 19, the valve port 17 is opened and the valve is opened. In the valve-open state, the first conduit 26 and the second conduit 27 are connected via the valve chamber 13. When the lower end 30a of the valve element 30 contacts the valve seat 19, the valve port 17 is closed and a valve-closed state is established. In the valve-closed state, the first conduit 26 and the second conduit 27 are cut off. The rotation of the spool 30 about the axis L is restricted.

The valve shaft 34 is made of, for example, a stainless steel material. The valve shaft 34 has an elongated cylindrical shape. The valve shaft 34 includes a large diameter portion 35, a small diameter portion 36 provided continuously with an upper end of the large diameter portion 35, and a disk portion 37 provided continuously with a lower end of the large diameter portion 35. The small diameter portion 36 has a smaller diameter than the large diameter portion 35. The diameter of the disk portion 37 is larger than that of the large diameter portion 35. The large diameter portion 35 has a male thread 35c on its outer peripheral surface. A lower stopper 64a is fixed to a lower end of the large diameter portion 35. An upper stopper 64b is fixed to the upper end of the large diameter portion 35. The lower stopper body 64a and the upper stopper body 64b rotate together with the valve shaft 34 and move in the vertical direction together with the valve shaft 34.

The coupling mechanism 40 couples the valve body 30 and the valve shaft 34. The coupling mechanism 40 includes a valve holder 41, a closing member 42, a spring support member 43, and a valve closing spring 44.

The valve holder 41 has a cylindrical shape. The periphery of the disk portion 37 of the valve shaft 34 is swaged and fixed to the upper end of the valve holder 41. The upper end of the valve holder 41 is connected to the valve shaft 34. An annular plate member 41a is fixed to the lower end of the valve holder 41 by caulking. An annular projection 41b projecting radially inward is provided on the inner side of the valve holder 41. A closing member 42 is disposed between the plate member 41a and the annular protrusion 41 b. An annular spacer 41c is disposed on the annular projection 41 b. The second portion 32 of the valve body 30 is inserted into the plate member 41a, the closing member 42, the annular protrusion 41b, and the spacer 41 c. The spacer 41c has an inner diameter smaller than the outer diameter of the first portion 31 of the spool 30. The first portion 31 is disposed above the spacer 41c inside the valve holder 41. The valve holder 41 supports the valve body 30 to be movable in the vertical direction.

The closing member 42 has a circular ring shape. In the present embodiment, the sealing member 42 includes an O-ring 42a made of a rubber material and an annular packing 42b made of Polytetrafluoroethylene (PTFE) disposed inside the O-ring 42 a. The gasket 42b is pressed against the outer peripheral surface of the second portion 32 of the spool 30.

The closing member 42 is disposed in a compressed state between the valve holder 41 and the second portion 32 of the spool 30. The closing member 42 closes a space between the valve chamber 13 and the back pressure chamber 45. In the present embodiment, the diameter of the second portion 32 of the valve element 30 (i.e., the diameter of the portion of the valve element 30 closed by the closing member 42) is equal to the diameter of the valve port 17.

The spring support member 43 has a cylindrical shape. A flange 43a protruding radially outward is provided at the lower end of the spring support member 43. The spring support member 43 is disposed inside the valve holder 41 so as to be movable in the vertical direction. The spring bearing member 43 rotates about the axis L together with the valve holder 41. The lower surface of the spring support member 43 contacts the first portion 31 of the spool 30 (i.e., the upper end 30b of the spool 30).

The valve closing spring 44 is a compression coil spring. The valve-closing spring 44 is disposed between the disk portion 37 of the valve shaft 34 and the flange 43a of the spring support member 43. The lower surface of the spring support member 43 is pressed against the first portion 31 of the valve body 30 by the valve closing spring 44. The valve closing spring 44 presses the valve body 30 downward (i.e., toward the lower end 30a of the valve body 30) via the spring support member 43.

A back pressure chamber 45 as a sealed space is provided inside the valve holder 41. The back pressure chamber 45 is partitioned from the valve chamber 13. The first portion 31 of the valve body 30, the spring support member 43, and the valve closing spring 44 are disposed in the back pressure chamber 45.

When the valve holder 41 moves upward together with the valve shaft 34, the first portion 31 of the valve body 30 is hooked on the spacer 41c, and the valve body 30 also moves upward. When the valve body 30 is separated from the valve seat 19, the first portion 31 is pressed against the spacer 41c via the spring support member 43 by the valve closing spring 44.

When the valve holder 41 moves downward together with the valve shaft 34, the valve body 30 also moves downward. When the valve body 30 contacts the valve seat 19, the movement of the valve body 30 is stopped, the valve holder 41 further moves downward, and the first portion 31 is separated from the spacer 41 c.

The housing 48 is made of, for example, a stainless steel material. The housing 48 has a cylindrical shape with the upper end closed. The outer diameter of the housing 48 is substantially equal to the outer diameter of the cylindrical member 25. The inner diameter of the case 48 is larger than the inner diameter of the cylindrical member 25. The lower end 48a of the case 48 is welded to the outer peripheral edge of the upper end surface 25e of the cylindrical member 25.

The guide bush 50 has a cylindrical portion 51, a cylindrical portion 52, and a flange-like disk 53. A first stopper 51a is provided at the lower end of the cylindrical portion 51. A second stopper 51b is provided at the upper end of the cylindrical portion 51. The columnar portion 51 is provided with a female screw 51c penetrating in the vertical direction. The male thread 35c of the valve shaft 34 is screwed to the female thread 51 c. When the valve shaft 34 rotates about the axis L, the valve shaft 34 moves in the up-down direction by the screw feed action. The columnar portion 51 supports the valve shaft 34 movably in the vertical direction. When the valve shaft 34 reaches the upper limit position, the lower stopper 64a abuts against the first stopper 51a, and the upward movement of the valve shaft 34 is restricted. When the valve shaft 34 reaches the lower limit position, the upper stopper 64b abuts against the second stopper 51b, and the downward movement of the valve shaft 34 is restricted. The cylindrical portion 52 is provided continuously with the lower end of the cylindrical portion 51. The disk portion 37 of the valve shaft 34, the lower stopper 64a, and the coupling mechanism 40 are inserted into the cylindrical portion 52. The inner diameter of the cylindrical portion 52 is equal to the outer diameter of the valve holder 41. The cylindrical portion 52 supports the valve holder 41 to be movable in the vertical direction. The flange-like disc 53 has a circular ring shape. The inner peripheral edge of the flange-like disk 53 is embedded in the cylindrical portion 51. The outer peripheral edge of the flange-like disc 53 is welded to the inner peripheral edge of the upper end surface 25e of the cylindrical member 25 of the valve main body 5. The guide sleeve 50 is directly fixed to the valve body 5. The guide sleeve 50 may be indirectly fixed to the valve main body 5 via another member.

The valve body driving unit 60 moves the valve body 30 in the vertical direction. The valve body 30 is brought into contact with and separated from the valve seat 19 by the valve body driving unit 60. The valve body drive section 60 includes a rotor 61 and a stator 62.

The rotor 61 has a cylindrical shape with the upper end closed. The rotor 61 has a cylindrical peripheral wall portion 61a and an upper wall portion 61b provided continuously to an upper end of the peripheral wall portion 61 a. The upper wall portion 61b is connected to the small diameter portion 36 of the valve shaft 34 via a connecting body 63. The rotor 61 is rotatably disposed inside the housing 48. The stator 62 is disposed outside the housing 48. A stepping motor is constituted by the rotor 61 and the stator 62.

In the motor-operated valve 1, the valve body 5 (the valve port 17, the valve seat 19, and the cylindrical member 25), the valve body 30 (the first portion 31 and the second portion 32), the valve shaft 34, the coupling mechanism 40 (the valve holder 41 and the spring bearing member 43), the housing 48, the guide bush 50 (the cylindrical portion 51, the cylindrical portion 52, and the flange-like disc 53), and the rotor 61 are arranged such that the central axes thereof coincide with the axis L.

Next, an example of the operation of the motor-operated valve 1 will be described.

In the motor-operated valve 1, the stator 62 is energized to rotate the rotor 61 in one direction. The valve shaft 34 rotates together with the rotor 61, and the valve shaft 34 moves downward by the screw feed action of the male screw 35c of the valve shaft 34 and the female screw 51c of the guide bush 50. The valve holder 41 also moves downward while rotating together with the valve shaft 34. At this time, the spring support member 43 also rotates together with the valve holder 41, and the spring support member 43 slides rotationally with respect to the valve body 30. As the valve holder 41 moves downward, the valve body 30 moves downward, and the valve body 30 contacts the valve seat 19 to close the valve port 17 (valve-closed state).

In the valve-closed state, the valve port 17 and the back pressure chamber 45 are connected through the pressure equalizing passage 33 of the valve body 30. Thus, the fluid pressure in the valve port 17 becomes equal to the fluid pressure in the back pressure chamber 45. Therefore, the force (force F1 in the valve opening direction) applied to the valve body 30 by the fluid pressure of the port 17 can be prevented from becoming significantly larger than the force (force F2 in the valve closing direction) applied to the valve body 30 by the fluid pressure of the back pressure chamber 45.

In the motor-operated valve 1, the stator 62 is energized to rotate the rotor 61 in the other direction. The valve shaft 34 rotates together with the rotor 61, and the valve shaft 34 moves downward by the screw feed action of the male screw 35c of the valve shaft 34 and the female screw 51c of the guide bush 50. The valve holder 41 also moves upward while rotating together with the valve shaft 34. At this time, the spring support member 43 also rotates together with the valve holder 41, and the spring support member 43 slides rotationally with respect to the valve body 30. As the valve holder 41 moves upward, the valve body 30 moves upward, and the valve body 30 separates from the valve seat 19 to open the valve port 17 (open valve state).

As described above, the motor-operated valve 1 of the present embodiment includes the valve holder 41 connected to the valve shaft 34. The cylindrical valve body 30 is supported by the valve holder 41 so as to be movable in the vertical direction. The lower end 30a of the valve element 30 contacts with and separates from the valve seat 19 of the valve port 17. The spring support member 43 is disposed inside the valve holder 41 so as to contact the upper end 30b of the valve body 30. The valve closing spring 44 presses the valve body 30 toward the lower end 30a via the spring support member 43. A back pressure chamber 45 as a sealed space is provided inside the valve holder 41. The valve body 30 is provided with a pressure equalizing passage 33 that connects the valve port 17 and the back pressure chamber 45 in a closed state. With this arrangement, the fluid pressure in the port 17 and the fluid pressure in the back pressure chamber 45 can be equalized in the valve-closed state. This prevents a very large difference between the upward force (force F1 in the valve opening direction) applied to the valve body 30 by the fluid pressure of the port 17 and the downward force (force F2 in the valve closing direction) applied to the valve body 30 by the fluid pressure of the back pressure chamber 45. Therefore, it is not necessary to increase the force of the valve closing spring 44, and deformation of the contact portion between the valve body 30 and the spring support member 43 can be suppressed.

Further, a closing member 42 is disposed between the valve holder 41 and the second portion 32 of the valve body 30. Also, the diameter of the port 17 is equal to the diameter of the second portion 32 of the spool 30. With this arrangement, the difference between the force F1 in the valve opening direction and the force F2 in the valve closing direction can be eliminated or made very small in the valve closed state. Therefore, it is not necessary to increase the force of the valve closing spring 44, and the deformation of the contact portion between the valve body 30 and the spring receiving member 43 can be more effectively suppressed. The diameter of the second portion 32 may be different from the diameter of the valve port 17, but in order to reduce the difference between the force F1 in the valve opening direction and the force F2 in the valve closing direction, it is preferable to reduce the difference between the diameter of the valve port 17 and the diameter of the second portion 32.

The embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. Those skilled in the art can appropriately add, delete, and modify the components of the above-described embodiments and appropriately combine the features of the embodiments without departing from the spirit of the present invention, and the scope of the present invention also encompasses these embodiments.

Claims

1. An electric valve is characterized in that the electric valve is provided with a valve body,

comprising:

a valve body provided with a valve chamber and a valve port;

a support member fixed with respect to the valve body;

a valve shaft supported by the support member so as to be movable in an axial direction;

a valve holder connected to the valve shaft and having a back pressure chamber therein;

a valve body supported by the valve holder so as to be movable in the axial direction, one end of the valve body being in contact with and separated from a valve seat of the valve port;

a spring support member disposed inside the valve holder so as to be in contact with the other end of the valve element; and

a valve-closing spring disposed in the back pressure chamber and pressing the valve element toward one end side via the spring support member,

the valve element is provided with a pressure equalizing passage that connects the valve port and the back pressure chamber in a state where one end of the valve element is in contact with the valve seat.

2. Electrically operated valve according to claim 1,

a closing member is disposed between the valve holder and the valve body,

the diameter of the valve port is equal to the diameter of the part of the valve core closed by the closing part.