JP2001141097A - Electric flow rate control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric flow rate control valve usable for high pressure fluid without impairing magnetic characteristics even if pressure of pressure fluid on a flow-in side is high. SOLUTION: This electric flow rate control valve consists of a valve body 1 which has a valve seat, in which a screw hole 3 is formed, and through which a central hole 2 communicating with a fluid flow-in hole and fluid flow-in hole across the valve seat passes, a lid plate 5 provided like a flange at outer periphery of the valve body, a rotor main body 10 which is provided with a valve element 6 whose tip opposes to the valve seat 7a at the center and in which a male screw 12 screw-fitting in a screw hole part is formed in a part to be inserted into the central hole of the valve body, a magnet 11 of a stepping motor provided cylindrically at outer periphery of the rotor main body, a cuplike sealing case 30 which is fitted into outer periphery of the magnet with a minute clearance, surrounds the rotor main body with magnet, and forms a sealed space together with the lid plate of the valve body, and an electromagnetic coil part 40 of the stepping motor which is integrated with the sealing case on an outer peripheral side of the sealing case to form a double layer body and whose opening end fringe part is provided in a stator 20 and at outer periphery of the stator of the cuplike stepping motor fixed on the lid plate of the valve body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-operated flow control valve in which a valve body is electrically connected to and separated from a valve seat so that a flow rate can be adjusted, for example, an electric expansion valve in a cooling circuit of a refrigerant air conditioning system.

[0002]

2. Description of the Related Art An electric flow control valve in the prior art is
For example, it is disclosed in Japanese Patent Publication No. 2-6299. In the electric flow control valve disclosed in Japanese Patent Publication No. 2-6299, the support cylinder 1 threadedly engaged with the needle valve 3 is used.
A cylindrical permanent magnet 11 is coupled to the outer peripheral surface of the
And a cup-shaped case 6 having an opening side coupled to the valve body 1 surrounds the rotor 9, and includes a rotor 9 together with the valve body 1.
Is formed, and an annular stator 8 having a coil 7 built in an internal space is fitted on the outer peripheral surface of the case 6. A stepping motor is constituted by the rotor 9 and the annular stator 8 containing the coil 7.

[0003] A primary port 1a and a secondary port 1b are formed in a valve body 1, and a needle valve 3 is provided in a partition wall therebetween.
Are formed to face each other. The pressure fluid flowing from the primary port 1a is supplied to the needle valve 3 and the valve seat 2 which are axially displaced by the rotation of the stepping motor and the screw engagement.
The liquid flows out to the secondary port 1b through the gap with a. At that time, the gas flows out into the sealed space in the case 6 through the outer circumferential gap and the screw engagement gap of the needle valve 3 in which the valve body 1 is displaceably inserted, and the sealed space is filled with the pressurized fluid. The pressure is applied to a cup-shaped case 6 whose opening side is connected to the valve body 1.

[0004]

In the above-mentioned prior art electric flow control valve, the high pressure of the pressure fluid on the inflow side with respect to the electric flow control valve is applied to the cup-shaped case whose opening side is connected to the valve body. . However, since the case is formed from a thin plate of a non-magnetic material, the pressure resistance of the case itself and the strength of coupling with the valve body are limited. Therefore,
When the thickness of the case is increased, the gap between the coil and the magnet is increased, and the magnetic characteristics are reduced. Therefore, such an electric flow control valve is difficult to use in a fluid circuit in which the pressure of the pressure fluid on the inflow side is large.

An object of the present invention is to provide a motor-operated flow control valve which can be used for high-pressure fluid without deteriorating magnetic characteristics even when the pressure of the inflow-side pressure fluid is high.

[0006]

The motor-operated flow control valve according to the present invention has a threaded hole portion, a valve seat, and a center hole communicating with the fluid inflow hole and the fluid inflow hole with the valve seat interposed therebetween. A penetrated valve body, a lid plate provided in a flange shape on the outer periphery of the valve body, a large-diameter portion and a small-diameter portion are formed, and the center is provided with a valve body whose tip is opposed to a valve seat, and is provided in a center hole of the valve body. A rotor body with a male screw threaded into the screw hole on the small diameter part to be inserted, a stepping motor magnet provided in a cylindrical shape on the outer circumference of the large diameter part of the rotor body, and a small gap fitted on the circumference of the magnet Then, surrounding the rotor body with magnet, forming a cup-shaped sealing case forming a sealed space together with the lid plate of the valve body, forming a double-layer body integrated with the sealing case on the outer peripheral side of the sealing case, The opening edge is fixed to the lid plate of the valve body. And an electromagnetic coil of the stepping motor provided on the outer periphery of the cup-shaped stepping motor stator and the stator.

[0007] An elastic body is interposed between the sealing case and the rotor body to maintain a rotatable abutting relationship between the end of the valve body and the center of the sealing case. Backlash between the hole and the external thread has been removed,
The sealing case and the stator are fixed to each other by forming projections by timbre processing of the sealing case with respect to the positioning small holes of the stator. Further, the fixation of the stator and the rotor main body is, for example, being carried by caulking the lid plate at the open end of the stator. For example, the stator may be configured such that a plurality of members having cylindrical comb-tooth portions are connected in the axial direction by meshing of the comb-tooth portions.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric flow control valve used as an electric expansion valve in a cooling circuit according to an embodiment of the present invention will be described with reference to the drawings. In the following description, up, down, left, and right are directions in FIG.

1 and 2, the upper small diameter portion 1a
The valve body 1, which is a cylindrical body with an outer peripheral step formed of a lower large-diameter portion 1b, is formed with a central hole 2 vertically penetrating vertically, and the central hole 2 is a large portion of the area of the small-diameter portion 1a. In the above, a screw is formed on the inner peripheral surface to form a screw hole 3, and the large diameter portion 1b
At the lower end, the hole becomes the enlarged diameter hole 4 to form a stepped hole. The small-diameter portion 1a of the valve body 1 has a lid plate 5 of an annular plate.
Is fixed to the outer peripheral step portion of the valve body 1.

A valve seat member 7 forming a valve seat 7a with respect to a needle valve portion 6a at the tip of a rod-shaped valve body 6 to be described later is fitted into the enlarged diameter hole portion 4, and a pipe joint T1 is inserted. . That is, the valve seat member 7 is fitted in a state of being sandwiched between the stepped portion of the center hole 2 (stepped hole) and the end face of the pipe joint T1.

Further, an inflow pipe joint hole 8 is formed in the outer peripheral surface of the large diameter portion 1b, and is formed in a radial direction toward a lower end position of the center hole 2, and is formed from the bottom of the inflow pipe joint hole 8 to the center hole 2. A communication hole 9 penetrates inward, and a pipe joint T2
Is inserted.

The electric flow control valve is connected to a pipe of a fluid circuit to which the flow control valve is applied via pipe joints T1 and T2. For example, when applied to a cooling circuit as shown in FIG. 6, the pipe joint T2 is connected to the pipe A on the condenser side,
Are connected to the pipes B on the evaporator side, respectively.

The rotor assembly integrated with the valve body 6 and displacing the valve body 6 in the axial direction includes a small diameter portion 10a and a large diameter portion 10a.
b, and a cylindrical magnet 11 fitted to the outer peripheral surface of the large diameter portion 10b of the rotor main body 10. Magnet 11
The electromagnetic coil portion 40 and the stator 2 have a length longer and lower than the large-diameter portion 10b and are disposed in the outer peripheral area thereof as described later.
0 constitutes a stepping motor.

The small-diameter portion 10a of the rotor body 10 becomes a male thread portion 12 having a thread cut on the outer peripheral surface at the base side following the large-diameter portion 10b, and is screwed into the screw hole 3 of the valve body 1.
The distal end is rotatably inserted into the center hole 2 of the valve body 1. The lower end of the rod-shaped valve element 6 fitted in the center hole of the small-diameter portion 10a of the rotor main body 10 extends below the small-diameter portion 10a of the rotor main body 10 and has a needle valve portion 6 at the tip.
“a” is opposed to the valve seat 7 a of the valve seat member 7. The upper end of the valve body 6 extends above the large diameter portion 10 b of the rotor body 10 and the magnet 11.

A spring receiving member 13 is inserted into the upper end of the valve body 6. In other words, the spring receiving member 13 is
3a and a lower leg 13b, a central projection 13c is formed on the top surface of the head 13a, and a central hole 13d is formed on the lower surface of the leg 13b.
The upper end of the valve body 6 is inserted into 3d so as to be axially displaceable.

The compression coil spring 14 surrounding the valve element 6 and the leg 13b of the spring receiving member 13 is
3 and is fitted between the bottom surface of the hollow portion of the large diameter portion 10b of the rotor body 10 and pushes the spring receiving member 13 upward.

As shown in FIG. 1, on the outer periphery of the magnet 11 of the rotor assembly, an outer surface is a magnetic stator 20 having an appropriate thickness of a magnetic material, and an inner surface is used for sealing a non-magnetic thin plate material. A cylindrical cup-shaped body having a two-layered structure and having a lower opening, which is the case 30, is fitted with an appropriate minute gap.

As shown in FIGS. 1 and 2, the sealing case 30 is a cylindrical cup having a lower opening and fitted on the outer periphery of the magnet 11 of the rotor assembly with a small gap. A large-diameter portion 30a is formed, and a projecting portion is formed outward at the center of the bottom wall portion so that the inner surface becomes a concave portion 30b.

As shown in FIG. 3, the stator 20 is composed of three members, an upper stator member 21, a middle stator member 22, and a lower stator member 23, which are assembled into a cup-shaped body.

As shown in FIG. 3, the upper stator member 21
Has a cup shape that covers the upper end of the sealing case 30, and the center of the inner surface of the bottom wall above the sealing case 30 is
0 is formed with a concave portion 21a in which a protruding portion on the outer surface of the bottom wall portion is fitted, and positioning small holes 21c, 2 are formed in the upper end portion of the peripheral wall portion 21b.
1c penetrates in the diametrical direction, and a comb-tooth-like portion 21d with downward teeth is formed below it.

The middle stator member 22 includes a sealing case 30.
It has a cylindrical shape that covers the outer peripheral surface of the head, and is formed of an upward comb-like portion 22a, a downward comb-like portion 22b, and an intermediate annular portion 22c therebetween. Positioning small hole 2 in intermediate annular portion 22c
2d and 22d penetrate in the diameter direction.

The lower stator member 23 is
Cylindrical comb-shaped part 2 which covers the outer peripheral surface of
3a and a large-diameter portion 23b whose diameter is increased below the comb-like portion 23a. Each of the comb-shaped portions of the upper stator member 21, the middle stator member 22, and the lower stator member 23 is meshed with each other to form a three-piece cylindrical cup-shaped stator 2 having a lower opening.
It becomes 0.

Then, as shown in FIG. 1, the two are fitted together with the sealing case 30 inside and the cylindrical cup-shaped stator 20 outside, and the protrusion of the bottom wall of the sealing case 30 is the upper stator member. 21 is fitted in a concave portion 21a at the center. And the positioning small hole 2 of the upper stator member 21
1c, 21c and positioning small hole 2 of middle stator member 22
2d and 22d, the peripheral wall portion of the sealing case 30 is subjected to dimple processing so that each protruding portion 30c is positioned in the positioning small hole 21d.
c, 21c; biting into positioning small holes 22d, 22d. Dimble processing is performed after covering the stator 20 on the sealing case 30. The welding of the sealing case 30 is performed by lifting only the lower stator member 23 of the covered stator 20 and sliding it upward. After welding, the lower stator member 23 is lowered and swaged. Sealing case 3
The large-diameter portion 23b of the lower stator member 23 fitted into the large-diameter portion 30a has a dimension in the axial direction that is appropriately long, and extends from the edge of the large-diameter portion 30a of the sealing case 30.

The valve body 1, valve body 6 and magnet 11 assembly are fitted into the inner surface of the stator 20 / sealing case 30 assembly of the magnetic material integrated as described above.
The center projection 13c of the spring receiving member 13 rotatably abuts the concave portion 30b at the center of the bottom surface of the sealing case 30, and the spring receiving member 13 is further pushed toward the valve body 1, and the spring receiving member 13 is pressed.
The compression coil spring 14 fitted between the head portion 13a of the rotor body 10 and the bottom surface of the hollow portion of the large diameter portion 10b of the rotor body 10 is appropriately compressed, and the lower end edge of the sealing case 30 is
Is abutted on the upper surface of the base plate and welded.

The backlash between the male screw portion 12 of the rotor body 10 and the screw hole 3 of the valve body 1 is eliminated by the compressed spring force of the compression coil spring 14.

Also, due to the spring force of the compressed compression coil spring 14, regardless of the axial displacement of the rotor body 10,
Since the center projection 13c of the spring receiving member 13 is rotatably abutted on the concave portion 30b at the center of the bottom surface of the sealing case 30, the upper portion of the rotor body 10 is stably held.

The edge of the large-diameter portion 23b of the lower stator member 23 projecting downward from the lid plate 5 covers the welded portion between the lower edge of the sealing case 30 and the annular plate lid plate 5. It is swaged toward the lower surface of the cover plate 5.

Thus, the assembly of the magnetic stator 20, the sealing case 30, the valve body 1, the valve body 6, and the magnet 11
The assembly and the assembly are integrated, and a closed space is formed by the sealing case 30, the cover plate 5, and the valve body 1.

An electromagnetic coil portion 40 of a stepping motor is fitted on the outer peripheral surface of the stator 20. The electromagnetic coil section 40 includes a lower plate 41 of a magnetic material, a lower electromagnetic coil 42,
An intermediate plate 43 and an upper electromagnetic coil 44 of a magnetic material are sequentially stacked, and the entire structure is surrounded by an outer box 45.
A grommet 46 protruding from the outer case 45 in the radial direction is provided with terminals 47 connected to the upper and lower electromagnetic coils 42, 44. The terminals 47 are connected to input lines from an external control unit (not shown). You. (See Fig. 3)

In the above configuration of the electric flow control valve, when a control pulse current from an external control unit is input to the upper and lower electromagnetic coils 42, 44, the electromagnetic coils 42, 44 and the stator based on the control pulse current are input. In the stepping motor, the assembly of the magnet 11, the rotor body 10, and the valve body 6 is rotated at a desired rotation angle according to a desired rotation direction and the number of pulses by the excitation action between the magnet and the desired rotation angle position. Is positioned.

The male screw portion 12 of the rotor body 10 and the valve body 1
When the rotor main body 10 rotates, the rotor main body 10 is displaced in the axial direction with respect to the fixed-side valve main body 1 by the screw connection with the screw holes 3. That is, the valve element 6 integrated with the rotor body 10
Is displaced in the axial direction with respect to the valve seat member 7 integrated with the valve body 1. Therefore, the position of the needle valve portion 6a with respect to the valve seat 7a, that is, the valve opening is determined to a desired value according to the desired rotation angle position of the rotor body 10.

In the cooling circuit, the pressurized refrigerant is
From the pipe A on the condenser side, through the communication hole 9 and the center hole 2 of the valve body 1 via the pipe joint T2, flows through the gap between the needle valve portion 6a and the valve seat 7a, and through the pipe joint T1. It flows to the pipe B on the evaporator side. The flow rate of the refrigerant is controlled by the position of the needle valve portion 6a with respect to the valve seat 7a based on the desired rotational angle position of the rotor body 10, that is, the valve opening.

The pressurized refrigerant that has flowed into the valve body 1 through the pipe joint T2 is supplied to the gap between the center hole 2 of the valve body 1 and the small diameter portion 10a of the rotor body 10, the screw hole 3 and the male screw portion 12
Flows into the closed space formed by the sealing case 30, the lid plate 5, and the valve body 1 with a pressurized pressure.

The pressure is maintained by the sealing case 30, the stator 20 layered on the outside thereof, and the lid plate 5 to which the stator 20 is caulked. Accordingly, not only the sealing case 30 made of a thin plate but also the thick stator 20 and the caulking connection thereof can withstand a high pressure.

As a second embodiment, the stator 50 is shown in FIG.
The upper stator 51 member and the upper middle stator member 5
2, 4 of lower middle stator member 53 and lower stator member 54
A configuration may be adopted in which three stator members are positioned and incorporated, and are integrated by die casting of aluminum or magnesium.

At this time, the concave portions 51a and 51a are aligned with the upper and lower stator members 51 and 54 for positioning with the mold.
54a are provided. In addition, the protrusion 5 is used for positioning for incorporating the upper middle stator member 52 and the lower middle stator member 53.
2a and 53a are provided.

As a third embodiment, a stator 50 is formed by positioning and incorporating four stator members, an upper stator member 51, an upper middle stator member 52, a lower middle stator member 53, and a lower stator member 54, and molded with engineer plastic or the like. And may be integrated. At this time, similarly to the second embodiment, the upper and lower stator members 51 and 54 are provided with the concave portions 51a and 54a for alignment with the mold.
Is provided. Also, the projections 52a, 52a,
53a is provided.

As shown in the left half of FIG. 5, when the stator 50 is integrated by die casting of aluminum or magnesium, the sealing case 30 and the lower lid 55 are formed.
Airtight by welding with After welding, the stator 50
, And the lower end 50a is swaged and fixed to secure the pressure resistance. Next, the coil 40 is fixed by caulking at the lower portion 48 of the outer box.

In the case where the stator 50 is formed by molding with an engineering plastic resin or the like and integrated with each other, FIG.
As shown in the right half, the lower end 50a of the stator 50 is welded to a hook member 56 provided on the large diameter portion 1b of the valve body,
Engineers to improve the pressure resistance of plastic resin.

[0040]

According to the electric flow control valve of the present invention, the shell surrounding the rotor of the stepping motor integrally formed with the valve body and forming a sealed space is not limited to a cup-shaped sealing case, but a cup-shaped sealing case. The stepping motor has a double-layer structure in which the stator is integrated on the outer peripheral side of the case, and the opening edge of the stator is fixed to the cover plate of the valve body. That is, since a thick magnetic stator covers the case and is fixed to the cover plate of the valve body as compared with the case made of a non-magnetic thin plate material, the pressure resistance against the pressure of the pressurized fluid in the closed space is usually high. The strength is increased and it can be used for high pressure fluid circuits.

When the stator is fixed to the valve body, the position is adjusted to the position with the rotor, that is, the initial opening of the valve. Therefore, it is not necessary to perform special positioning when attaching the electromagnetic coil portion to the valve body. You can decide freely.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electric flow control valve according to a first embodiment of the present invention.

FIG. 2 is a first exploded perspective partial view (a valve body and a sealing case) of the electric flow control valve according to the first embodiment of the present invention.

FIG. 3 is a second exploded perspective partial view of the electric flow control valve according to the first embodiment of the present invention (electromagnetic coil unit / stator);
It is.

FIG. 4 is a second exploded perspective partial view (an electromagnetic coil unit and a stator) of the electric flow control valve according to the second and third embodiments of the present invention.

FIG. 5 is a cross-sectional view of a motorized flow control valve according to an embodiment of the present invention, and the right half is a cross-sectional view of a motorized flow control valve according to another embodiment of the present invention.

FIG. 6 is a schematic diagram of a cooling circuit of a refrigerant air-conditioning system using an electric flow control valve as an expansion valve according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve main body 1a Small diameter part 1b Large diameter part 2 Center hole 3 Screw hole 4 Large diameter hole part 5 Cover plate 6 Valve body 6a Needle valve part 7 Valve seat member 7a Valve seat 8 Inlet fitting hole 9 Communication hole 10 Rotor body 10a Small diameter part 10b Large diameter part 11 Magnet 12 Male screw part 13 Spring receiving member 13a Head 13b Leg 13c Center projection 13d Center hole 14 Compression coil spring 20 Stator 20a Stator 20b Stator 21 Upper stator member 21a Recess 21b Peripheral wall 21c Positioning small hole 21d Comb-like portion 21e Upper stator member 22 Middle stator member 22a Upward comb-like portion 22b Lower comb-like portion 22c Intermediate annular portion 22d Positioning small hole 22e Upper middle stator member 23 Lower stator member 23a Comb-like portion 23b Large diameter portion 23e Lower middle stator member 24e Lower stator member 30 Sealing case 30a large diameter portion 30b recess 40 electromagnetic coil portion 41 upper electromagnetic coil intermediate plate 44 the lower plate 42 under the electromagnetic coil 43 45 outside a box 46 grommet 47 terminals T1, T2 fitting A, B line

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H062 AA02 AA15 BB31 BB33 CC02 DD01 EE08 FF41 5H002 AA02 AB07 AC04 5H605 BB05 BB17 CC05 CC08 CC09 CC10 DD37 EA12 GG03 GG06

Claims (8)

[Claims] A valve body having a screw hole formed therein and having a valve seat, a center hole communicating with the fluid inflow hole and the fluid inflow hole interposed between the valve seats, and a flange shape on the outer periphery of the valve body. The provided lid plate has a large-diameter portion and a small-diameter portion formed around a valve body having a distal end facing the valve seat, and is screwed into a screw hole portion at the small-diameter portion inserted into the center hole of the valve body. A rotor body with an external thread formed, a stepping motor magnet cylindrically provided on the outer periphery of a large diameter portion of the rotor body, a small gap fitted on the outer periphery of the magnet, surrounding the rotor body with magnet, A cup-shaped sealing case that forms a sealed space together with the lid plate. The outer peripheral side of the sealing case is integrated with the sealing case to form a double layer body, and the opening edge is fixed to the valve body lid plate. Cup-shaped stepper motor stator Electric flow control valve is an electromagnetic coil of the stepping motor provided on the outer periphery of the fine stator. 2. An elastic body is interposed between the sealing case and the rotor body, and a rotatable contact relationship is maintained between an end of the valve body and the center of the sealing case. 2. The electric flow control valve according to claim 1, wherein backlash between the screw hole and the external thread is removed. 3. The motor-operated flow rate control valve according to claim 1, wherein the sealing case and the stator are fixed to each other by forming protrusions by timbre processing of the sealing case with respect to the positioning small holes of the stator. 4. The electric flow control valve according to claim 1, wherein the stator and the rotor main body are fixed to each other by caulking a cover plate at an open end of the stator. 5. The electric flow rate according to claim 1, wherein the stator is formed by connecting a plurality of members having cylindrical comb teeth in the axial direction by meshing the comb teeth. Control valve. 6. The electric flow control valve according to claim 1, wherein the stator is formed by forming a plurality of members having cylindrical comb teeth formed therein by die-casting in an axial direction with the comb teeth meshing with each other. 7. The electric flow control valve according to claim 1, wherein the stator is formed by molding a plurality of material portions having cylindrical comb teeth formed therein by resin molding in an axial direction with the comb teeth meshing with each other. . 8. The motor-operated flow control valve according to claim 7, wherein the stator and the rotor main body are fixed to each other by pressure welding or bonding the stator opening end and the cover plate.