JP2009275895A - Flow control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow control valve of simple structure with a small number of parts items, low in the manufacturing costs and having high reliability on the device. <P>SOLUTION: This flow control valve 1 comprises: a first valve chamber 5 communicated with a first flow passage 3a, and communicated with a second flow passage 4a through a valve seat 5a; a valve element 6 arranged inside the first valve chamber to be brought in contact or separated with/from the valve seat; a valve rod 8 for controlling a flow rate between the first flow passage and the second flow passage by moving in the axial direction to bring the valve element in contact or to separate it with/from the valve element; a through-hole 8a passing through the valve rod to communicate the second flow passage with a second valve chamber 14; and a moving body 7 moving in the axil direction of the valve rod, being interlocked with the valve rod to partition the first valve chamber and the second valve chamber from each other. It is desirable to provide a rotor 18 rotating around an axis in the state of limiting movement of the valve rod in the axial direction and a transmitting screw 22 to be moved in the axial direction of the valve rod, being rotated with the rotor, in one end thereof and screwed to the valve rod in the other end thereof to move the valve rod in the axial direction of the valve rod and in the same direction as the moving direction of the one end in the state of limiting rotation of the valve rod around the axis of the valve rod. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flow rate control valve that is used for controlling the refrigerant flow rate of a refrigeration cycle and that opens and closes a valve body by an electric motor or the like.

  In a refrigeration cycle, a flow control valve for high pressure and a large flow rate may be required. As a flow control valve for such an application, there has been proposed a double seat valve that includes two valve ports in a valve housing and that is opened and closed by two valve portions formed on the valve body (for example, patents). Reference 1 and 2). This double seat valve cancels the force in the valve opening / closing direction by applying the force in the valve opening / closing direction caused by the pressure difference between the upstream side and the downstream side of the valve to both of the above two valve parts. A large flow rate can be controlled while reducing a required driving force.

JP 2005-201407 A JP 2004-353862 A

  However, the multi-seat valve needs to form a flow path for each valve port in the valve housing, which complicates the overall structure and increases the number of parts. There was a problem that this was likely to occur and the reliability of the device was lacking.

  Therefore, the present invention has been made in view of the problems in the conventional flow rate control valve described above, and by reducing the number of parts and simplifying the structure, the assembly is easy and the manufacturing cost is low. An object is to provide a flow control valve with high reliability and a large flow rate.

  In order to achieve the above object, the present invention is a flow rate control valve, which communicates with a first flow path and communicates with a second flow path via a valve seat, and the first valve chamber. The valve body that is disposed in contact with and away from the valve seat and moves in the axial direction so that the valve body is brought into contact with and separated from the valve seat so as to be between the first flow path and the second flow path. A valve rod for controlling the flow rate, a through hole penetrating the valve rod and communicating the second flow path and the second valve chamber, and the first valve chamber and the second valve in conjunction with the valve rod And a moving body that moves in the axial direction of the valve rod while partitioning the chamber.

  According to the present invention, since the second flow path and the second valve chamber are communicated with each other by the through hole penetrating the valve rod, the fluid pressure in the second flow path is applied to the moving body via the second valve chamber. The fluid pressure in the second flow path and the fluid pressure in the second valve chamber that is the same as the fluid pressure are applied to the valve stem through the valve body and the moving body, and only the fluid pressure in the second flow path is applied. Compared with the conventional single seat valve to which is added, the driving force required for the movement of the valve stem, that is, the valve opening and closing can be reduced. In addition, according to the present invention, since the flow control valve is constituted by a single seat valve, the number of parts can be reduced compared to a double seat valve, the structure can be simplified, assembly is facilitated, Cost reduction and device reliability can be improved.

  In the flow rate control valve, the opening area of the valve seat and the area of the opening cross section obtained by cutting the second valve chamber with a plane perpendicular to the axial direction of the valve rod can be made equal. Thereby, the force applied to the valve body by the fluid pressure of the second flow path is equal to the force applied to the moving body by the fluid pressure of the second valve chamber, and the force in the valve opening / closing direction applied to the valve stem is offset, The driving force required for opening and closing the valve can be reduced.

  Further, in the flow rate control valve, a rotor that rotates around the axis in a state where movement of the valve stem in the axial direction is restricted, and one end moves in the axial direction of the valve stem while rotating together with the rotor. At the other end, the valve stem is rotated in the axial direction of the valve stem in a state where the rotation of the valve stem around the axis of the valve stem is restricted while being screwed with the valve stem. A transmission screw that moves in the same direction as the moving direction can be provided. Thus, when the rotor rotates, the one end of the transmission screw moves in the axial direction of the valve stem while rotating, and further, the rotation of the transmission screw causes the valve rod to move in the axial direction of the valve stem and the moving direction of the one end. It can be moved in the same direction, the lift amount of the valve per rotation of the rotor can be increased, and a large flow rate can be provided with a small lift amount. Further, since the rotor itself does not move up and down, the positional relationship with the stator as a motor is not changed, so that the valve can always be driven with the maximum torque.

  Furthermore, the flow rate control valve may further include a lip seal that slidably contacts the moving body while partitioning the first valve chamber and the second valve chamber together with the moving body. Since the lip seal is excellent in sealing performance as well as slidability, the first valve chamber and the second valve chamber can be partitioned stably and reliably, and stable valve operation can be maintained.

  As described above, according to the present invention, it is possible to provide a flow control valve having a small number of parts, a simple structure, easy assembly, low manufacturing cost, and high device reliability.

  Next, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show an embodiment of a flow control valve according to the present invention. The flow control valve 1 is roughly divided into pipe connection portions 3 and 4 and a valve seat 5a inside. A valve body 2 having a single valve chamber 5, a valve rod 8 that is housed in the valve body 2, and integrally includes a valve body 6 and a moving body 7, and is located above the valve body 2, together with the moving body 7 A holder 11 that forms the second valve chamber 14, and a lip seal 12 and an O-ring 13 that are interposed between the holder 11 and the moving body 7 and seal between the first valve chamber 5 and the second valve chamber 14. And a rotor 18 that is a component of the pulse motor assembly 34 and rotates about the axis of the valve stem 8; a transmission screw that has an upper portion coupled to the rotor 18 via a driver 25 and a lower portion coupled to the valve stem 8; 22 etc.

  The valve body 2 is formed in a bottomed cylindrical shape having an upper opening, and the pipe connecting portions 3 and 4 are inserted and fixed in the side opening. A first valve chamber 5 is formed inside the valve body 2. The first valve chamber 5 communicates with a flow path (hereinafter referred to as a “first flow path”) 3a in the pipe connection portion 3 and a flow path (hereinafter referred to as “a flow path” in the pipe connection portion 4 via the valve seat 5a. 4a)).

  A valve stem 8 is arranged inside the valve body 2, and a second valve chamber 14 is provided between the moving body 7 positioned at the top of the valve stem 8 and the holder 11 screwed onto the top of the valve body 2. It is formed. A lip seal 12 and an O-ring 13 are arranged between the lower inner wall of the holder 11 and the outer peripheral surface of the moving body 7 in order to seal between the first valve chamber 5 and the second valve chamber 14. . The lip seal 12 is integrally formed of fluororesin or the like, and includes a lip portion 12a. The lip seal 12 performs sealing by sliding while the tip of the lip portion 12a is pressed against the outer peripheral surface of the moving body 7. Since the lip seal 12 is excellent in sealability and slidability, the first valve chamber 5 and the second valve chamber 14 can be partitioned stably and reliably. As this lip seal 12, for example, a Dyna lip seal manufactured by FURON of the United States can be used.

  The valve stem 8 is accommodated in the valve main body 2, and has a valve body 6 at the center in the axial direction and a moving body 7 at the top. The valve stem 8 has an outer diameter D3 over the entire length except for the valve body 6 and the moving body 7. The valve body 6 is formed in a disk shape, and the edge of the lower surface is in contact with or separated from the valve seat 5a, thereby opening or blocking between the first flow path 3a and the second flow path 4a. The movable body 7 is formed in a bottomed cylindrical shape that opens upward, and its bottom surface is urged downward by a coil spring 23. Thereby, the valve body 6 can contact | abut to the valve seat 5a in the 1st valve chamber 5, and can interrupt | block between the 1st flow path 3a and the 2nd flow path 4a. In addition, a through hole 8a is formed in the valve rod 8, and the second flow path 4a and the second valve chamber 14 communicate with each other through the through hole 8a. The diameter D1 of the opening cross section of the valve seat 5a and the diameter D2 of the opening cross section obtained by cutting the second valve chamber 14 with a plane perpendicular to the axial direction of the valve rod 8 are set to the same dimension.

  As clearly shown in FIG. 2, the upper end portion of the valve stem 8 is subjected to internal thread processing, and the internal thread portion 8 b is screwed with an external thread portion 22 a that is screwed as a right-hand thread at the lower end of the transmission screw 22. A pin 35 is fixed to the upper part of the valve stem 8 and is configured to be movable up and down along a slit 20 b formed at the lower end of the driver guide 20. As a result, when the transmission screw 22 rotates together with the rotor 18, the valve stem 8 can move up and down without rotating along with the transmission screw 22.

  An upper portion of the transmission screw 22 is formed with a deformed cross-section (commonly referred to as a D cut, an oval cut, a two-sided width cut, etc.) 22c, and slides in the slit 25a of the driver 25. It is configured to move up and down. In addition, a male screw portion 22 b is screwed on the upper side of the transmission screw 22 as a left screw, and is screwed into the female screw portion 20 a of the driver guide 20 fixed to the holder 11. The male screw portion 22b (left screw) of the transmission screw 22 is screwed so as to be reverse to the lower male screw portion 22a (right screw).

  The rotor 18 is a component of the pulse motor assembly 34 and rotates around the axis of the valve stem 8 in accordance with the number of pulses applied from the outside. The rotor 18 is formed in a cylindrical shape, and is connected to the driver 25 through the insert metal 26 in the can 33.

  The driver 25 is formed in a cylindrical shape with a large diameter at the upper portion and a small diameter cylindrical shape with a slit portion 25a at the lower portion. A cylindrical stopper 31 is fixed at the upper portion, and an upper surface is fixed at the can 33. The coil spring 32 is biased downward. Further, a bush 19 is interposed between the driver 25 and the driver guide 20, and the driver 25 and the driver guide 20 are configured to be rotatable relative to each other.

  The driver guide 20 is formed in a cylindrical shape as a whole, and includes a slit 20b at the bottom. The middle part of the driver guide 20 is inserted and fixed to the upper part of the holder 11. The female screw portion 20 a of the driver guide 20 is screwed into the male screw portion 22 b of the transmission screw 22. Further, the pin 35 fixed to the valve stem 8 moves up and down in the slit portion 20b of the driver guide 20.

  The pulse motor assembly 34 including the rotor 18 and the can 33 is fixed to the holder 11 by the fixing pipe 21.

  With the above configuration, the rotor 18 rotates at a fixed position without moving up and down. On the other hand, when the transmission screw 22 rotates through the insert metal 26 and the driver 25 as the rotor 18 rotates, the deformed cross-section portion 22c of the transmission screw 22 rotates while moving up or down in the slit portion 25a of the driver 25. Then, the entire transmission screw 22 can move up and down as the rotor 18 rotates.

  Next, the operation of the flow control valve 1 will be described.

  It is assumed that the low-pressure fluid is sealed in the first flow path 3a and the high-pressure fluid is sealed in the second flow path 4a when the valve is closed as shown in FIGS. The high-pressure fluid in the second flow path 4 a enters the second valve chamber 14 through the through hole 8 a of the valve rod 8 and fills the second valve chamber 14. In this state, a load is applied to the valve stem 8 due to the differential pressure between the two fluids. For example, when the pressure of the high-pressure fluid is PH and the pressure of the low-pressure fluid is PL, a force due to the fluid pressure is applied to the valve body 6 and the moving body 7 integrated with the valve rod 8 in the vertical direction.

Specifically, the outer diameter of the valve stem 8 is D3 over the entire length (excluding the portions of the valve body 6 and the moving body 7), and the diameter of the opening cross section of the valve seat 5a is D1, A force F1 represented by the following formula 1 acts upward.
F1 = (PH-PL) × {π (D1 / 2) ² −π (D3 / 2) ² }
= (PH-PL) × π × (D1 ² -D3 ² ) / 4 (Formula 1)

On the other hand, when the second valve chamber 14 is cut along a plane perpendicular to the axial direction of the valve stem 8, the diameter of the opening cross section is D2. Act on.
F2 = (PH-PL) × {π (D2 / 2) ² −π (D3 / 2) ² }
= (PH-PL) × π × (D2 ² −D3 ² ) / 4 (Formula 2)

  Here, since D1 = D2 is set as described above, F1 = F2, and the axial direction of the valve stem 8 added to the valve stem 8 via the valve body 6 and the moving body 7, that is, valve opening / closing. The direction force is offset, and the driving force required for opening and closing the valve can be reduced.

  Next, when a pulse is applied to the pulse motor assembly 34 from the outside to rotate the rotor 18, the driver 25 rotates and the transmission screw 22 rotates in the same direction as the rotor 18. Here, since the upper surface of the driver 25 is urged downward by the coil spring 32 fixed to the can 33 and the driver guide 20 is fixed to the holder 11, the rotor 18 and the driver 25 are arranged in the vertical direction. Rotate the fixed position without moving. On the other hand, the transmission screw 22 is screwed with a female screw portion 20a of the driver guide 20 fixed to the holder 11 at a male screw portion 22b that is screwed as a left screw, and a deformed cross-sectional portion 22c thereof is a slit portion 25a of the driver 25. Since the inside of the transmission screw 22 is configured to be movable in the vertical direction, when the transmission screw 22 rotates together with the rotor 18 and the driver 25 in the clockwise direction as viewed from above in FIGS. 1 and 2, the transmission screw 22 as a whole moves upward. .

  Further, by the rotation of the transmission screw 22, the male screw portion 22a screwed as the right screw of the transmission screw 22 and the female screw portion 8b of the valve stem 8 are screwed together, but a pin fixed to the upper portion of the valve stem 8 35 is configured to be movable up and down along the slit 20 b formed at the lower end of the driver guide 20, the valve stem 8 moves upward without being rotated around the transmission screw 22. Due to the upward movement of the valve stem 8, the valve body 6 also moves upward, and the valve body 6 moves away from the valve seat 5a, whereby fluid flows from the second flow path 4a to the first flow path 3a. The gap width between the valve body 6 and the valve seat 5a can be adjusted, and the flow rate of the fluid flowing through the gap can be adjusted.

  As described above, when the rotor 18 rotates clockwise as viewed from above in FIGS. 1 and 2, the transmission screw 22 rises while rotating, and further, the valve stem 8 can be raised by the rotation of the transmission screw 22. Therefore, the lift amount of the valve body 6 per one rotation of the rotor 18 can be increased, and a large flow rate can be provided with a small number of rotations of the rotor 18.

  In the above configuration, since the rotor 18 rotates at a fixed position without moving in the vertical direction, the rotor 18 can always be positioned in the optimum magnetic field, and an efficient operation can be performed.

  In the above embodiment, the case where the rotor 18 is a part of the pulse motor assembly 34 has been described as an example. However, the rotor 18 may be rotated by a hydraulic motor, and the type of driving means thereof is not limited. Absent.

It is a whole sectional view showing one embodiment of a flow control valve concerning the present invention. It is an expanded sectional view which shows the transmission screw of the flow control valve of FIG. 1, and its vicinity.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flow control valve 2 Valve body 3 Piping connection part 3a 1st flow path 4 Piping connection part 4a 2nd flow path 5 1st valve chamber 5a Valve seat 6 Valve body 7 Moving body 8 Valve rod 8a Through-hole 11 Holder 12 Lip seal 12a Lip part 13 O-ring 14 Second valve chamber 18 Rotor 19 Bush 20 Driver guide 20a Female threaded part 20b Slotted part 21 Fixing pipe 22 Transmission screw 22a Male threaded part (right thread)
22b Male thread (Left thread)
22c Modified cross section 23 Coil spring 25 Driver 25a Slot 26 Insert metal 31 Stopper 32 Coil spring 33 Can 34 Pulse motor assembly 35 Pin

Claims (4)

A first valve chamber communicating with the first flow path and communicating with the second flow path via the valve seat;
A valve body disposed in the first valve chamber and contacting and separating from the valve seat;
A valve stem that moves in the axial direction to control the flow rate between the first flow path and the second flow path by bringing the valve body into and out of contact with the valve seat;
A through hole penetrating the valve stem and communicating the second flow path and the second valve chamber;
A flow control valve comprising: a moving body that moves in an axial direction of the valve rod while partitioning the first valve chamber and the second valve chamber in conjunction with the valve rod.   2. The flow control valve according to claim 1, wherein an opening area of the valve seat is equal to an area of an opening cross section obtained by cutting the second valve chamber along a plane perpendicular to the axial direction of the valve stem. A rotor that rotates about the axis in a state where movement of the valve stem in the axial direction is limited;
The one end moves in the axial direction of the valve stem while rotating together with the rotor, and the other end is restricted from rotating around the axis of the valve stem while being screwed with the valve stem at the other end. The flow control valve according to claim 1, further comprising a transmission screw that moves the valve stem in an axial direction of the valve stem and in the same direction as the movement direction of the one end.   4. The flow rate control valve according to claim 1, further comprising a lip seal that slidably contacts the moving body while partitioning the first valve chamber and the second valve chamber together with the moving body.

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