WO2003023265A1

WO2003023265A1 - Control valve

Info

Publication number: WO2003023265A1
Application number: PCT/JP2002/009207
Authority: WO
Inventors: Toru Yonezawa
Original assignee: Chiyoda Kuchokiki Co., Ltd.
Priority date: 2001-09-11
Filing date: 2002-09-09
Publication date: 2003-03-20
Also published as: JP2005048779A

Abstract

A control valve capable of preventing a valve head from biting in a valve seat, capable of being reversed satisfactorily, and capable of eliminating chattering at the time of valve closing while facilitating the overall configuration thereof, comprising a valve stem (3) moving forward and backward interlockingly with a rotating drive body (8) and seating and departing the valve head (4) on and from the valve seat (2) provided in a valve casing (1), wherein the rotatingly driving body (8) is directly coupled to the valve stem (3) through a large lead screw having a large lead relative to a screw diameter, and a rotation stop body (9) for preventing the valve stem from being rotated as the rotatingly driving body is rotated is provided between the valve casing (1) and the valve stem (3).

Description

Title of invention

Conto Mouth One Reno Reb

Technical field

The present invention relates to a control valve such as an electric expansion valve mainly interposed in a refrigerant pipe of an air conditioner or a refrigerator.

Background art

Conventionally, this type of valve V has been disclosed in Japanese Patent Publication No. Hei 3-330750, and as shown in FIG. 9, a conical valve head H is seated on a valve seat Z provided on a valve housing D. Equipped with a stem N to be separated. The valve stem N passes through the inside of an externally threaded pipe M provided upright in the valve housing D, and the rear end thereof is inserted into the transverse wall W of the rotor R of the stepping motor S and is stopped by the retaining ring Y. Between the stem N and the transverse wall W, a stem pushing spring Q is interposed.

On the outside of the male screw pipe M, a female screw pipe F integrated with the rotor R is screwed, and the forward and reverse rotation of the rotor R at a predetermined angle moves the valve stem N forward and backward. The flow rate is controlled by changing the opening area between them. A movable stopper K, which is rotated by a standing rod J on a rotor R, is moved along a spiral guide G wound around a hanging shaft T of a case upper lid U, and a lower locking portion B and an upper locking portion E are moved. This restricts the rotation range of the rotor R and thus the reciprocation range of the valve stem N.

By the way, in the conventional control valve V described above, when the valve head H of the valve rod N is seated on the valve seat Z when the valve is closed, the movable stopper K is abutted against the lower locking portion B and is locked. The valve head H is pressed against the valve seat Z only by the spring force of the panel Q. For this reason, if an excessive force exceeding the pressing force of the valve stem holding panel Q acts in the valve opening direction due to a transient change in the refrigerant pressure before and after the closed valve seat Z, the valve stem N will lift. A problem occurs in which the valve cannot be closed. In practice, a so-called chattering phenomenon occurs in which valve opening and closing are repeated in a short time.

Here, it is conceivable to adopt a structure in which the valve stem N is directly tightened to the valve seat Z with a screw, instead of closing the valve to the valve stem holding screw Q. However, even if the structure is changed to simply tightening with a screw, the valve head H enters the valve seat Z, and the thread is crushed, so that the valve cannot be opened by reversing the screw. Disclosure of the invention

In the present invention, by adopting a combination of a large lead screw and a non-rotating structure, a structure is adopted in which the valve stem is directly pressed to the valve seat. It is another object of the present invention to provide a control valve which can be satisfactorily reversed, can simplify the entire configuration, and can eliminate the chattering phenomenon when the valve is closed.

According to a first aspect of the present invention, there is provided a control valve including a valve stem that moves forward and backward in conjunction with a rotary driving body and seats and separates a valve head on a valve seat provided in a valve housing. In the above, the rotation driving body and the valve stem are directly connected via a large lead screw having a large lead to a screw diameter, and a rotation preventing body that Plih rotates the valve stem accompanying rotation of the rotation driving body. Intervened.

As a result, the valve stem can be pressed directly against the valve seat by the rotary driver, and the chattering phenomenon at the time of closing the valve can be eliminated. Also, the valve stem is pressed against the valve seat in a state in which its rotation is blocked by the rotation stopper, so that the valve head can be prevented from penetrating into the valve seat. In addition, the large lead screw prevents the screw thread from being crushed, and the valve opening due to reverse rotation can be improved. Furthermore, since the valve stem is directly driven, there is no need for a special mechanism such as a movable stopper for restricting the advance / retreat range of the valve stem, which is conventionally required, and the configuration can be simplified. The invention according to claim 2 is characterized in that, while adopting a large lead screw, the valve stem is biased in the axial direction in order to reduce fluctuations in the flow path opening area when the valve is opened during flow control or the like. Thus, an elastic member for stabilizing the behavior when the valve stem is separated from the valve seat is interposed.

As a result, the gap between the rotary driving body and the valve stem due to the large lead screw is kept almost constant, and the movement and vibration of the valve stem due to the pressure change between the inlet and the outlet of the valve seat can be suppressed. The change in the flow channel area can be reduced. Also, it is possible to reduce the occurrence of abnormal noise due to the vibration of the valve stem when the refrigerant passes.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a longitudinal sectional view of a first embodiment of the control valve of the present invention.

FIG. 2 is a perspective view of the first embodiment viewed from below.

FIG. 3 is an assembled view of the first embodiment as viewed from above. FIG. 4 is an explanatory diagram of a large lead screw according to the first embodiment.

FIG. 5 is a longitudinal sectional view of a second embodiment of the control valve of the present invention.

FIG. 6 is a perspective view of the second embodiment viewed from below.

FIG. 7 is an assembled view of the second embodiment viewed from above.

FIG. 8 is an explanatory diagram of a large lead screw according to the second embodiment.

Fig. 9 is a longitudinal sectional view of a conventional control valve.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows an example of application to a large-capacity motor-operated valve, in which a first connection pipe 11 and a second connection pipe 12 are orthogonally connected to a valve housing 1. For example, the first connection pipe 11 is connected to the outdoor unit, and the second connection pipe 12 is connected to the indoor unit. A valve seat 2 is provided inside the valve housing 1, and an integrated Udle-shaped valve head 4 faces the tip of a valve stem 3 having a square pole shape. Note that the valve head 4 does not have to be a needle type. The flow path opening area is changed by moving the valve stem 3 back and forth so that the flow rate can be controlled continuously from 0 when the valve is closed to fully open. .

The valve stem 3 is linked to a magnet rotor 61 of a stepping motor 6 with a planetary gear reducer 5 interposed therebetween. The planetary gear reducer 5 is housed in a reducer case 7 composed of a lower lid 71 attached to the valve housing 1 and an upper lid 72 placed on the lower lid 71. The magnet rotor 61 is housed in a rotor case 62 fitted into the upper lid 72. A stator coil 63 is fitted on the outside of the rotor case 62. The motor shaft 60 is supported by an upper bearing 64 and a lower bearing 65.

As shown in FIGS. 2 and 3, the planetary gear reducer 5 includes a first sun gear S 1 integrally connected to a motor shaft 60, the first sun gear S 1, and an internal gear D 0 fixed to the outside. Three first planetary gears U l, U l, and U l, a first carrier R l holding these first planetary gears, and a motor shaft 6 integrated with the first carrier R 1 on the side opposite to the motor. The second sun gear S 2, which rotates to zero, three second planet gears U 2, U 2, U 2, which mesh with the second sun gear S 2 and the outer internal gear D 0. It has a second carrier R2 that holds the gear. A boss 8 that is screwed to the valve stem 3 is integrated with a lower portion of the second carrier R2 serving as a rotary driving body that drives the valve stem 3. The square pole portion of the valve stem 3 passes through the square hole 90 formed in the square-shaped detent body 9 with a bottom that is press-fit into the valve housing 1, and the valve stem 3 rotates with the rotation of the boss 8. In order to prevent them. The detent structure may use a polygon other than a square.

A panel receiver 91 is locked at an intermediate portion of the valve stem 3, and an elastic member 92 made of a compression panel is interposed between the rotation stopper 9 on the valve housing 1 side, and the valve stem 3 is axially upward. It biases and stabilizes the behavior when the valve stem 3 separates from the valve seat 2.

The gears S1, Ul, Rl, S2, U2, and R2 of the planetary gear reducer 5 are tightly assembled in contact with each other while improving the axial direction. A thrust plate 93 that receives the lower end of the motor shaft 60 is provided on the upper surface of the second carrier R2. As shown in FIG. 4, the valve stem 3 and the boss 8 have a large screw lead (r) with respect to the circumferential length (q) of the average screw diameter, that is, a screw gradient (rZq) of 8% or more. It is directly connected via large lead screws 30 and 80. Although a large lead male screw 30 is provided on the valve stem 3 side and a large lead female screw 80 is provided on the boss 8 side, that is, on the rotary driver side, the relationship between male and female may be reversed.

FIG. 5 shows an example of application to a direct-acting motor-operated valve without a reduction gear. In a valve case 1, a first connection pipe 11 and a second connection pipe 12 are orthogonally connected. For example, the first connection pipe 11 is connected to the outdoor unit side, and the second connection pipe 12 is connected to the indoor unit side. A valve seat 2 is provided inside the valve housing 1, and a needle-shaped valve head 4 integrated with the end of a valve rod 3 having a square pole faces. Note that the valve head 4 does not have to be a needle type. The flow path opening area is changed by the advance and retreat of the valve stem 3, so that the flow rate can be controlled continuously from 0 when the valve is closed to fully open.

The valve stem 3 is directly linked to the magnet rotor 6 10 of the stepping motor 6 constituting a rotary drive. The magnet rotor 6100 is housed in a rotor case 67 that covers the lower flange 66 attached to the valve housing 1. A stator coil 63 is fitted on the outside of the rotor case 67. The upper portion of the shaft hole 6200 provided in the center of the magnet rotor 6100 is received in a stepped cylindrical upper bearing 640. The lower part of the magnet rotor 6100 is thrust supported on the front plate 6500. As shown in Figs. 6 and 7, the square pole portion of the valve stem 3 is a square hole of the block-shaped detent body 9 that receives the pins 960, 960 in the receiving holes 660, 660 of the front plate 650 and is mounted non-rotatably. Through 900, the rotation of the valve stem 3 accompanying rotation of the magnet rotor 610 is prevented. The detent structure may use a polygon other than a square.

An elastic member 920 composed of a compression panel is interposed between the upper end of the valve stem 3 and the upper bearing 640 to urge the valve stem 3 downward in the axial direction, and the behavior when the valve stem 3 separates from the valve seat 2 Has been stabilized.

As shown in FIG. 8, the valve stem 3 and the magnet rotor 610 have a large screw lead (r) with respect to the circumferential length (q) of the average screw diameter, that is, a large screw gradient (rZq) of 8% or more. Directly connected via lead screws 300 and 800. A large lead male screw 300 is provided on the valve stem 3 side and a large lead female screw 800 is provided on the rotary driver side, but the relationship between male and female may be reversed.

Claims

The scope of the claims

1. A control valve having a valve stem that moves forward and backward in conjunction with a rotary driver and seats and separates a valve head from a valve seat provided in a valve housing, wherein the rotary driver and the valve stem are arranged with respect to a screw diameter. A control pulp characterized by being directly connected via a large lead screw having a large lead, and having a rotation preventing body interposed therebetween for preventing the valve stem from rotating together with the rotation of the rotary driving body.

2. The control valve according to claim 1, further comprising an elastic member for urging the valve stem in an axial direction to stabilize a behavior of the valve stem when the valve stem is separated from the valve seat.