JPH08159320A - Motor-driven flow control valve - Google Patents

Abstract

PURPOSE: To properly maintain a minimum flowrate even at a closing process, and prevent a defective operation, regarding a control valve having a valve disc operated with a stepping motor. CONSTITUTION: A valve body 100 has a valve chamber 110 as well as an orifice 114. A valve disc 250 inserted in the orifice 114 is pressed into a valve holder 200, and this holder 200 is screwed to a bush 220 fixed to the body 100. Also, a rotor member 170 made of a resin sleeve 174 and a magnetic sleeve 172 is fitted to the holder 200, and rotatably supported in a can 150. Furthermore, a stator member is detachably fitted to the external surface of the can 150. In this case, the outside dimension of the valve disc 250 is formed to be smaller than the inner diameter of the orifice 114, thereby providing a minimum flowrate even at a valve closing process. One of a shaft 180 connected to the center of the member 170 and a bearing member 160 is tapered, thereby preventing the member 170 from falling in a three-point support state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric flow control valve used for controlling the flow rate of a fluid such as a refrigerant used in a refrigeration cycle.

[0002]

2. Description of the Related Art FIG. 7 shows an electric flow control valve disclosed in Japanese Patent Laid-Open No. 6-174129. In this electric flow rate control valve, a stepping motor M is constituted by a rotor 10 arranged inside a can 6 which is a hermetic container and a stator coil 9 arranged outside the can 6. This electric flow rate control valve has a primary port 1a and a secondary port 1b communicating with the valve chamber 1 and a communicating valve port 3 of a secondary port side partition wall 2 (inner hole of a valve seat 4 screwed and fixed to the partition wall 2). Valve seat 3a
A valve body A provided with a valve body, a long rod-shaped needle valve 5'that comes into contact with and separates from the valve seat 3a of the valve body A, and the side portion of the valve body A opposite to the secondary port 1b. A rotor having a cylindrical closed case 6 to be fixed and a stator coil 9 arranged outside the case, and being movable inside the case 6 in a valve opening / closing direction that is rotated by energization and excitation of the stator coil 9. 10 is provided with a pulse controllable stepping motor M, and a valve actuating mechanism B that opens and closes the needle valve 5'by a screw feeding action by the rotation of the rotor of the stepping motor M. A secondary port 1b connected to one flow path Pa and orthogonal to the primary port 1a
The second flow path Pb is connected to.

The closed case 6 is composed of a lower lid 7 and a can 8, and the rotor 10 is a cylindrical sleeve 11.
And a cylindrical permanent magnet 12 fitted to the outside of the sleeve 11. The valve operating mechanism B has an internal thread portion 31 and a bearing portion 32 on the inner side, and the valve body A
And a cylindrical bush 30 embedded and fixed to the resin lid 33 of the bush so as to hang down into the valve chamber 1, and the female thread portion 31 of the bush.
Male screw part 36 and the bush bearing part 32 screwed together
The rotor 10 having a rotation support portion 37 guided by
A valve holder 35 is concentrically embedded and fixed in the center of the (sleeve 11 made of synthetic resin).

Then, a needle valve 5'having a valve element which is biased in the valve projecting direction by a compression spring inside the valve holder 35, and a fixing ring (the valve body A for restricting the position of the needle valve 5 '). Needle valve 5'for the valve seat 3a of the
Has a function of adjusting the position of the valve when assembling the valve), and the valve holder 35 is provided with a shaft portion 35a protruding into the sleeve rear end recess 11a.
The recessed shaft bearing body 40, which guides the a, can be loosely fitted to the rear end (the upper end in the figure) of the can 8.
The rotor 10 is fixed to the inner portion and the rotor 10 is fixed to the bush bearing portion 3
A double-end bearing structure composed of the shaft 2 and the shaft bearing body 40 holds the shaft bearing body 40 so that the shaft can rotate and move.

The screw length of the female screw portion 31 and the male screw portion 36 is set to be equal to or longer than the opening / closing stroke of the needle valve 5 ', and when the needle valve 5a is fully opened, the male screw portion 36 of the valve holder 35 is set to the above-mentioned length. The bush 30 is disengaged from the female screw portion 31, and the rotor 1
A return spring 41 is incorporated between 0 and the shaft bearing body 40. The return spring 41 is separated from the shaft bearing body 40 when the needle valve 5'is opened and closed, and is opened when the needle valve 5'is fully opened.
The rotor 10 and the valve holder 35 are contacted with and compressed.
Has a function of urging the holder male screw portion 36 in a direction in which it engages with the bush female screw portion 31.

The screw threaded portions of the female screw portion 31 and the male screw portion 36 are arranged in the valve chamber 1 of the valve body A, and the valve chamber 1
A fluid (for example, a refrigerant) containing an oil component supplied therein is lubricated in the screw threaded portion. 18a in the figure
Is a valve closing control pin integrally provided on the lower end portion of the sleeve 11, 19a is a fully closed stopper integrally provided on the resin lid of the valve body A, and the needle valve 5'is closed. At this time, the pin 18a comes into contact with the outer peripheral surface of the fully closed stopper 19a to regulate the valve closing lower limit of the rotor 10. 42 is a motor connector portion having a coil energizing terminal.

[0007]

In the conventional electric flow control valve described in FIG. 7, when the valve is closed, the needless valve 5'is provided.
Is pressed against the valve seat 3a to fully close the flow path. Then, even when the valve holder 35 starts to move up when the valve is opened, the needle valve 5'is pressed against the valve seat by the spring, the flow path does not open, and the lift exceeds a predetermined distance, The flow path begins to open. Therefore, when the valve holder list is plotted on the horizontal axis and the flow rate is plotted on the vertical axis, the curve C ₁ has a shape as shown in FIG. However, depending on the type of refrigeration cycle, there is a specification that requires a certain amount of flow rate even when the valve is fully closed.
The present invention provides an electric flow control valve that satisfies the above requirements.

[0008]

The electric flow control valve of the present invention has, as a basic means, a valve main body having a valve chamber and an orifice, a cylindrical can attached to the valve main body, and an outside of the can. A rotor member disposed inside the can, a valve holder integral with the rotor member, and a valve body that is replaceably attached to the valve holder, and the valve holder rotates the rotor member. The area of the flow passage between the valve body and the orifice is controlled by the screw feeding action by the, and the diameter dimension of the valve body is formed smaller than the inner diameter dimension of the orifice. Further, the tapered portion is formed in the engaging portion of the shaft with the bearing member, or the tapered portion is formed in the engaging portion of the bearing member with the shaft.

[0009]

According to the present invention, by providing the above structure, it is possible to maintain a predetermined minimum flow rate even when the valve is closed, and between the valve body and the member supporting the member integrated with the valve body. By avoiding the three-point support, the malfunction is prevented.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing the overall construction of an electric flow control valve of the present invention, and FIG. Code 1 as a whole
The electric flow control valve indicated by A is a rotor member 170 of a stepping motor housed inside a cylindrical can 150.
And a stator member 300 of the stepping motor arranged outside the can 150. Stator member 300
Is a yoke 320 housed in the molded body 310, a bobbin 330 provided inside the yoke 320, and a bobbin 3
It has a magnet wire 340 wound around 30. The molded body 310 is integrally provided with a housing 352 for electric wiring, and the wiring 350 is attached thereto. Housing 35
The inside of 2 is filled with an epoxy resin 354.

A boss portion 312 projects from the upper portion of the molded body 310, and a stopper 362 is provided by a tapping screw 360.
Is fixed. The stopper 362 is made of an elastic plate material and has a protrusion 364. The stator member 300 is attachable to and detachable from the can 150,
At the time of mounting, the stator member 300 is assembled into the can 150 from above the can 150. A flange portion 152 that extends to the outer periphery is provided at the lower portion of the can 150, and the stator member 300 is placed on this flange portion 152. In this state, in the stator member 300, the protrusion 364 of the stopper 360 attached to the molded body 310 has the can 150.
The groove member 154 is engaged with the stator member 300 to fix the stator member 300. Since the stator member 300 is detachably attached, replacement and maintenance of the stator member 300 are easy. Further, when assembling the can and the valve body or attaching the pipe to the valve body, the work can be performed with the stator member removed, and the workability is improved.

As shown in FIG. 2, a bearing member 160 is installed at the top of the inside of the can 150 and slidably guides the upper portion of the shaft 180 of the rotor member. Can 15
The flange portion 132 of the lid member 130 is superposed on the lower flange portion 152 of 0, and the both are connected by, for example, welding. The lid member 130 includes an outer peripheral portion 1 of the valve body 100.
04 is fitted.

The valve body 100 is made of brass, for example,
It has a valve chamber 110, a primary port 112 communicating with the valve chamber 110, and a secondary port 114 forming an orifice, and pipes 122 and 124 are connected to the respective ports. Orifice 11
On the valve chamber 110 side of No. 4, a tapered valve seat 116 is formed. Orifice 114 of valve chamber 110 of valve body 100
A circular hole 118 is provided concentrically with the orifice 114 at a position opposed to, and a bush 220 is inserted into the circular hole 118. The bush 220 is assembled to the valve body 100 by crimping the protruding portion 102 of the valve body 100 inward. The round hole 118 has an axial groove 1
19 is provided, and a fluid such as a refrigerant fills the inside of the can 150 through the groove 119. The bush 220 is
For example, it is made of steel, has a female thread 222, and the male thread 202 of the valve holder 200 inserted into the bush 220 is screwed. The valve holder 200 holds the valve body 250 press-fitted into the inner diameter portion 204.

The valve holder 200 is axially guided by the outer periphery 224 of the valve holder 200 as it rotates in the bush 220. The shaft 180 is pressed into the center of the valve holder 200. A resin sleeve 174 is integrally formed on the outer peripheral portion of the valve holder 200. A spring 182 is provided on the shaft 180 above the resin sleeve 174. A sleeve 172 made of a magnetic material is integrally formed on the outer peripheral portion of the sleeve 174 made of a resin, which is made by integrally molding a material obtained by mixing magnetic powder such as ferrite with resin. Resin sleeve 1
74 and the sleeve 172 made of a magnetic material are integrated to form the rotor member 170. When the pulse signal is input to the stator member 300, the rotor member 170 rotates, and the valve holder 200 receives the lead of the screw with the bush 220 and moves in the axial direction. The valve body 250 enters the orifice 114 of the valve body integrally with the valve holder 220 to adjust the flow passage area.

A stopper 230 made of resin is attached to the upper portion of the bush 220, and a protrusion 176 provided on the lower surface of a resin sleeve 174 of the rotor member 170 abuts a protrusion 232 of the stopper 230, whereby the valve body 250
The lower limit position of is regulated. FIG. 3 is an explanatory diagram showing the relationship between the valve body 250 and the orifice 114 in the valve closed state.
In the electric flow control valve of the present invention, the orifice 114
The outer diameter D ₁ of the valve body 250 is smaller than the inner diameter H ₁ of the above. Therefore, even when the valve body 250 is in the closed state in which the valve body 250 is inserted into the orifice 114, the minimum flow path is open and the flow rate is secured. By changing the taper angle of the taper portion 256 at the tip portion of the valve body 250, it is possible to select a flow rate change that increases in proportion to the lift amount of the valve body.

The electric flow control valve according to the present invention is shown in FIG.
The characteristics shown in can be obtained. A curve C ₁₂ shows a change while the valve body 250 in the closed state rises to the lift L ₂ in the orifice 114, and a curve C ₁₀ shows that the lift is L ₂ or more and the taper portion 256 is pulled out from the valve seat 116. 4 shows the change in flow rate with respect to lift of the valve holder during ejection. The valve holder 200 is guided by the bush 220,
Moves in the axial direction at the same time as rotation. When closing the valve from the valve opening, the valve body 250 also moves in the axial direction along with the rotation, and the taper portion 256 is guided by the valve seat 116 and the orifice 11
4 is inserted. As shown in FIG. 2, in the valve closed state, the valve holder 200 and the valve body 250 have the first sliding portion S ₁ formed by the orifice and the valve body and the valve holder 20.
0 and the second sliding portion S ₂ formed by the bush 220.
It will be slidably supported at two points.

Even in this closed valve state, the valve holder 200
The shaft 180 press-fitted in the upper part of the
It is in a state of being inserted into the hole 162. this is,
This structure is necessary to prevent the rotor 170 from falling when opening the valve from the closed state and to function as a guide when the valve holder 200 moves upward in the axial direction. However, at this time, when the third sliding portion S ₃ formed by the shaft 180 and the hole of the bearing member 160 is in a state of restraining the shaft 180, the shaft 180 and the valve holder 20
The rotary body composed of 0 and the valve body 250 is supported at three points. Even if there is a slight dimensional error, this three-point support structure causes defective rotation of the rotating body, resulting in defective valve opening. Therefore, in the present invention, this shaft 1
The structure of 80 and the bearing member 160 is structured to avoid three-point support.

FIG. 5 shows the first embodiment. In this embodiment, the tapered portion 1 is provided at the tip of the shaft 180.
84 is formed so as to be inserted into the hole 162 of the bearing member 160. When the valve is closed, the shaft 180
A sufficient clearance is formed between the tapered portion 184 and the hole 162, and the three-point support is not achieved. In the valve open state, the shaft 180 is inserted into the hole 162 of the bearing member 160, and the shaft 180 is supported by the bearing member 160. In this valve open state, the valve body 250 has slipped out of the orifice 114, and the valve body 250 and the orifice 114 do not interfere with each other.

Next, FIG. 6 shows a second embodiment of the present invention. In the present embodiment, the tapered portion 162a is formed on the bearing member 160a side, and the hole 164 is formed in the tapered portion 162a.
a is provided. Then, the shaft 180a is inserted into the hole 164a guided by the tapered portion 162a. The tip portion 184a of the shaft 180a may have the same shape as the shaft 180a and need not be tapered. By forming the shaft 180 with an elastic body, it is possible to avoid the three-point support state without tapering the shaft or the bearing portion. INDUSTRIAL APPLICABILITY As described above, the present invention provides an electric flow rate control valve capable of ensuring a predetermined minimum flow rate even when the valve body is inserted into the orifice and closed, and the valve body is rotated. This is a structure in which a rotating body including a rotor of a stepping motor that is moved in the axial direction is supported at two points. With this structure, the valve body does not interfere with the orifice to cause a malfunction, and smooth operation can be achieved.

For example, even in the conventional electric flow control valve shown in FIG. 7, it is possible to obtain the minimum flow rate when the valve is closed by always opening a communication hole other than the orifice. However, since this communication hole is a fine hole, it is difficult to process, and clogging is likely to occur. Further, it is possible to obtain a flow rate when the valve is closed by providing a groove in the valve seat portion of the orifice. However, this processing results in the provision of a groove in the tapered portion, and it is necessary to increase the number of steps.

[0021]

The present invention solves the above problems,
It is possible to secure the minimum flow rate when the valve is closed. further,
It is possible to prevent malfunctions caused by three-point support between the valve body and the member integrated with the valve body and the member supporting the member.

[Brief description of drawings]

FIG. 1 is a sectional view showing the overall configuration of an electric flow control valve of the present invention.

FIG. 2 is a sectional view showing a main part of the electric flow control valve of the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a valve body and an orifice.

FIG. 4 is a graph showing the characteristics of the control valve of the present invention.

FIG. 5 is an explanatory view showing an embodiment of a bearing portion.

FIG. 6 is an explanatory view showing another embodiment of the bearing portion.

FIG. 7 is a cross-sectional view of a conventional electric control valve.

FIG. 8 is a graph showing characteristics of a conventional electric control valve.

[Explanation of symbols]

 100 valve body 110 valve chamber 114 orifice 116 valve seat 150 can 160 bearing member 170 rotor 180 shaft 200 valve holder 220 bush 250 valve body 300 stator member 310 molded body 320 yoke 330 bobbin 340 wire

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[Procedure amendment]

[Submission date] December 6, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

In the conventional electric flow control valve described in FIG. 7 [0008] is the time of closing Needle valve 5'
Is pressed against the valve seat 3a to fully close the flow path. Then, even when the valve holder 35 starts to move up when the valve is opened, the needle valve 5'is pressed against the valve seat by the spring, the flow path does not open, and the lift exceeds a predetermined distance, The flow path begins to open. Therefore, the re oice valve holder on the horizontal axis, when taking a flow rate vertical axis, the curve C ₁ has a shape as shown in FIG. 8. However, depending on the type of refrigeration cycle, there is a specification that requires a certain amount of flow rate even when the valve is fully closed.
The present invention provides an electric flow control valve that satisfies the above requirements.

Claims (3)

[Claims] 1. A valve body having a valve chamber and an orifice, a cylindrical can attached to the valve body, a stator member arranged outside the can, and a rotor member arranged inside the can. It has a valve holder integrated with the rotor member and a valve body that is replaceably attached to the valve holder. The valve holder controls the flow passage area between the valve body and the orifice by the screw feeding action by the rotation of the rotor member. An electric flow control valve in which the diameter of the valve body is smaller than the inner diameter of the orifice. 2. A valve main body having a valve chamber and an orifice, a cylindrical can attached to the valve main body, a stator member arranged outside the can, and a rotor member arranged inside the can. A valve holder integral with the rotor member, a valve body that is interchangeably attached to the valve holder, a bush that is fixed to the valve body and supports the valve holder by screw engagement,
The valve holder has a shaft whose one end is press-fitted and the other end is supported by a bearing member at the top of the can. The valve holder controls the flow passage area between the valve body and the orifice by the screw feeding action by the rotation of the rotor member. At the same time, the electric flow control valve is formed such that the diameter of the valve element is smaller than the inner diameter of the orifice, and the tapered portion is formed in the engaging portion of the shaft with the bearing member. 3. A valve body having a valve chamber and an orifice, a cylindrical can attached to the valve body, a stator member arranged outside the can, and a rotor member arranged inside the can. A valve holder integral with the rotor member, a valve body that is interchangeably attached to the valve holder, a bush that is fixed to the valve body and supports the valve holder by screw engagement,
The valve holder has a shaft whose one end is press-fitted and the other end is supported by a bearing member at the top of the can. The valve holder controls the flow passage area between the valve body and the orifice by the screw feeding action by the rotation of the rotor member. At the same time, the valve body has a smaller diameter dimension than the inner diameter dimension of the orifice, and a tapered portion is formed at the engaging portion of the bearing member with the shaft.