JPH0821558A - Proportional control valve with moving coil - Google Patents

Abstract

PURPOSE:To suppress the cost by improving the structure of a diaphragm, and thereby lessening the number of component parts and the man-hours in assembly works while self-excitating vibration is precluded. CONSTITUTION:A moving coil type proportional control valve comprises a body 2 to restrict a valve hole 23, a valve element 3 which is furnished in the body movably through a diaphragm 4 and adjusts the degree of opening of the valve hole, a core fixed relative to the body, a permanent magnet installed outside a core in its radial direction, a moving member which is installed movable between the core and permanent magnet, is furnished with a coil at the periphery, and presses the valve element while moving together with the coil when it is fed with current, and further a spring which presses resiliently the valve element toward the moving member. In the center of the disphragm 4, a cap part 41 is formed in a single piece structure, to which the end of the valve element 3 is fitted. The moving member is contacted with this cap part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called moving coil type proportional control valve which controls a flow rate by moving a valve body according to a value of a current flowing to a coil, and absorbs vibration of secondary pressure so that the valve body self-operates. The present invention relates to improvement in which adverse effects on flow rate control characteristics due to excited vibration are reduced.

[0002]

2. Description of the Related Art A conventional proportional control valve of this type is disclosed, for example, in Japanese Utility Model Laid-Open No. 5-52483. In these proportional control valves, as shown in FIG. 3, a valve body c for adjusting the opening degree of the valve mouth a is arranged in a main body b in which a valve mouth a is formed, and the valve body c is surrounded by an outer circumference. Is supported by a diaphragm d fixed to the main body b, and a permanent magnet e is fixed to the upper portion of the main body b, and a core f made of a magnetic material having a columnar shape that forms a magnetic path is arranged and fixed inside the permanent magnet. , A cylindrical movable member g that comes into contact with the valve body is movably provided on the outer periphery of the core f and inside the permanent magnet, and a coil h is wound around the outer periphery of the movable member so that the coil can be energized from the outside. West,
A spring i that supports the load of the valve body c is provided below the valve body c, and the position of the movable member g is changed up and down according to the current value flowing to the coil h, and the opening of the valve opening a is changed to the current value. It is changed in proportion to.

By the way, in the structure prior to the one described in the above publication, although the movable member g is made of a synthetic resin material having little elasticity and little vibration absorption, the movable member g has a lower end. Since the upper end of the shaft portion of the valve element c is directly received in the formed hole, the vibration of the valve element is not absorbed, and when the current flowing through the coil is small and the valve opening is small, the valve element self-excited. Vibration is likely to occur, and this self-excited vibration not only adversely affects the control characteristics of the control valve, but also causes a so-called governor squeal phenomenon.

Therefore, as shown in FIG. 4, a hole m is formed in the wall k at the lower end of the movable member g, and an elastic member n for absorbing vibration is fitted in the hole m, and a valve is attached to the elastic member n. A protrusion o formed integrally with the upper part of the body is brought into contact with the elastic body n to absorb the vibration of the valve body to prevent the governor squeal phenomenon.

However, in such a conventional proportional control valve, a step of press-fitting the elastic member n is required, which not only increases the number of manufacturing steps and increases the cost but also the diaphragm receiving member p is used as the valve body. Since the receiving member p is fixed to the valve body by a snap ring or a pin q, the number of parts is increased, which also causes an increase in cost of the proportional control valve.

[0006]

The problem to be solved by the present invention is, in a moving coil type proportional control valve,
By improving the structure of the diaphragm, it is possible to reduce the number of components and the number of assembling steps while preventing self-excited vibration, thereby achieving cost reduction.

[0007]

According to the present invention, there is provided a main body for limiting a valve opening, a valve body movably provided in the main body through a diaphragm for adjusting the opening of the valve opening, and A core fixed with respect to the main body, a permanent magnet arranged radially outside of the core, and a coil provided on the outer periphery movably arranged between the core and the permanent magnet. In a moving coil type proportional control valve including a movable member that moves together with the coil to press the valve body by energizing the coil, and a spring that elastically presses the valve body toward the movable member, a central portion of the diaphragm. Is integrally formed with a cap portion having a hole, the end portion of the valve body is fitted into the hole of the cap portion, and the movable member is brought into contact with the cap portion.

In the above moving coil type proportional control valve, a pressure support member may be disposed on the outer periphery of the cap portion to support the diaphragm in contact with the diaphragm, and a protrusion may be formed on the outer periphery of the cap portion. The protrusion may be engaged with the pressure support member to prevent the pressure support member from falling off the cap portion.

[0009]

In the above construction, when the coil is not energized, the valve body is pushed by the spring in the direction of closing the valve opening to close the valve opening, and restricts or prevents the fluid from flowing through the valve opening. When the coil is energized, the movable member moves the valve body against the force of the spring in proportion to the current value, and increases the opening of the valve opening in proportion to the current value. Therefore, the flow rate of the fluid passing through the valve opening is also proportional to the value of the current flowing through the coil. The self-excited vibration of the valve body is absorbed by the cap portion of the diaphragm, so that its adverse effect is reduced. Moreover, the number of parts of the proportional control valve and the number of assembling steps are reduced, and the cost can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a moving coil type proportional control valve 1 of the present embodiment. In the figure, 2 is a main body in which an inlet (primary side) port 21, an outlet chamber 22 leading to an outlet (secondary side) port (not shown) and a valve port 23 are formed, and 3 is movable in the main body 2. A valve element 4 arranged to control the opening and closing of the valve opening 23 by the flare portion 31 at the lower end, 4 is a diaphragm whose outer periphery is fixed to the main body 2 and the valve element 3 is attached to the central portion, and 5 is a drive part of the valve element 3. Is. A lower cover 25 is detachably attached to the lower surface of the main body 2 by a known means such as a set screw. An annular upper cover 26 is attached on the main body 2, and the outer periphery of the diaphragm 4 is fixed in a state of being sandwiched between the main body 2 and the upper cover 26. A spring 6 is arranged between the flare portion 31 of the valve body 3 and the lower cover 25 to bias the valve body in the direction (closer in the figure) to close the valve opening 23 at the flare portion.

The drive unit 5 is disposed on the upper cover 26, and the annular spacer 51 made of a non-magnetic material is disposed on the upper cover 26, and the drive unit 5 is also disposed on the spacer. An annular magnetic member 52, an annular permanent magnet 53 disposed and fixed on the magnetic member 52 in contact with the magnetic member, a columnar portion 54a concentric with the inner side of the permanent magnet 53, and a flange portion 54b permanent. A coil 56 is wound around the outer periphery of the core 54, which is movably disposed within a gap between the core 54 mounted and fixed on the magnet and the permanent magnet 53 and the cylindrical portion 54a of the core 54. And a movable member 55. Reference numeral 57 is a cover that surrounds the permanent magnet 53, the core 54, and the like. Further, the coil 56 is connected to an external power source through a conductive wire 58 by a known method.

In the present invention, the diaphragm 4 is made of a material such as rubber which is rich in elasticity and easily absorbs vibration, and the cap portion 41 at the central portion thereof and the thin flap portion 46 around the same are integrally formed. Has been formed. As shown in detail in FIGS. 2 and 3, the cap portion 41 includes
A hole 42 that opens to the valve body 3 side is formed. This hole 4
2, the diameter of the inner portion 42b is larger than the diameter of the inlet portion 42a. Further, on the outer periphery of the cap portion 41,
As shown in FIG. 2, a plurality of protrusions 44 protruding outward in the radial direction are formed at intervals in the circumferential direction. The projection may be formed in a ring shape on the entire outer circumference. The upper end of the valve body 3, that is, the end 32 on the diaphragm side is reduced in diameter so as to enter the hole 42 of the diaphragm 4, and the tip end thereof is formed with a flange portion 33 that fits tightly into the inner portion 42b of the hole. ing. Therefore, the end portion 32 of the valve body 3 is inserted into the hole 42.
When it is fitted inside, the flange portion 33 makes the flange portion 42b deep inside the hole.
It is designed so that it does not come out easily when entering inside. A thick ring portion 47 is integrally formed on the outer periphery of the flap portion 46. The thickness of the upper end portion of the cap portion 41 is thicker than that of the flap portion.

An annular pressure support member 7 is fitted around the outer periphery of the cap portion 41. One end surface (lower surface in FIG. 1) 71 of the pressure support member 7 contacts a portion of the diaphragm 4 on the radially inner side of the flap portion 46 near the portion connected to the cap portion 41, and pressure is applied to the lower surface of the diaphragm 4. Sometimes I support it so that it doesn't bend extremely. Therefore, the radial width of the pressure support member 7 and the end surface 71
The shape of is determined in consideration of the material of the diaphragm, the thickness of the flap portion 46, the pressure received by the diaphragm, and the like. An annular protrusion 72 extending inward in the radial direction is formed on the lower end side of the pressure support member 7, and the pressure support member 7 is provided on the outer periphery of the cap portion 41 and the end face 71 is provided on the flap portion 46.
The upper surface (the surface opposite to the end surface 71) of the projection 72 is engaged with the projection 44 formed on the outer periphery of the cap portion 41 when pushed into contact with. Therefore, in this state, the pressure support member 7 is prevented from falling off the outer periphery of the cap portion.

A long projection 55b extending from the lower end wall 55a toward the valve body is integrally formed at the lower end of the movable member 55 of the drive unit 5. The lower end of the protrusion 55b is rounded so as to come into contact with the upper end surface of the cap portion 41 of the diaphragm 4.

In the proportional control valve having the above structure, the coil 5
When 6 is not energized, no force is generated in the movable member to move to the valve body 3 side, so the valve body 3 is pushed upward by the spring 6, and as shown in the left half of FIG. The flare portion 31 contacts the lower end edge of the valve opening 23 of the main body 2 to close the valve opening 23.

Next, when the coil 56 is energized, the movable member 55 moves the valve body 3 downward against the force of the spring 6 in proportion to the current value, and the flare portion 31 is moved to the lower end edge of the valve opening 23. The opening of the valve opening 23 is increased in proportion to the current value. Therefore, the flow rate of the fluid passing through the valve opening is also proportional to the value of the current flowing through the coil 56.

Due to the structural characteristics of the moving coil type control valve, it is inevitable that the valve body 55 vibrates by itself when the opening of the valve opening is small, but the tip of the projection 55b of the movable member 55 (see FIG. 1). Since the lower end is in contact with the upper end surface of the cap portion 41 of the diaphragm 4 made of a material that is rich in elasticity and easily absorbs vibration, the movable member 55 and the valve body 3 are connected via the cap portion, The vibration of the valve element is absorbed by the elastic member to suppress the governor squeal, and the adverse effect on the control characteristics is reduced. A member such as a sponge, which is more likely to absorb vibration, may be attached to the upper surface of the cap portion.

[0018]

According to the present invention, the following effects can be obtained. (1) Since the cap portion is formed on the diaphragm and the movable member and the valve body come into contact with each other via the cap portion, the number of processing steps of the control valve can be made smaller than that of the conventional control valve, and the cost of the control valve can be reduced. You can (2) Since the number of constituent parts of the control valve can be reduced as compared with the conventional one, the cost of the control valve can be reduced also in this respect.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a moving coil type proportional control valve according to the present invention.

FIG. 2 is an enlarged cross section of a diaphragm.

FIG. 3 is a perspective view of a diaphragm.

FIG. 4 is a sectional view of an example of a conventional moving coil type proportional control valve.

[Explanation of symbols]

 1 Moving coil type proportional control valve 2 Main body 21 Inlet port 22 Outlet port 23 Valve mouth 3 Valve body 32 Tip 4 Diaphragm 41 Cap part 42 Hole 44 Projection part 46 Flap part 5 Drive part 53 Permanent magnet 54 Core 55 Movable member 6 Spring

Claims (3)

[Claims] 1. A main body defining a valve opening, a valve body movably provided in the main body via a diaphragm to adjust the opening of the valve opening, and a core fixed with respect to the main body. A permanent magnet disposed on the outer side of the core in the radial direction and a coil provided on the outer periphery of the permanent magnet so as to be movable between the core and the permanent magnet and moving together with the coil by energizing the coil. In a moving coil type proportional control valve including a movable member that presses the valve body with a spring and a spring that elastically presses the valve body toward the movable member, a cap portion having a hole at the center of the diaphragm is provided. A moving coil type proportional control valve, which is integrally formed, fits an end portion of the valve body in the hole of the cap portion, and abuts the movable member on the cap portion. 2. The moving coil type proportional control valve according to claim 1, wherein a pressure support member that contacts the diaphragm and supports the diaphragm is provided on the outer periphery of the cap portion. 3. The moving coil proportional control valve according to claim 2, wherein a protrusion is formed on the outer periphery of the cap portion, the protrusion engaging with the pressure support member, and the pressure support member Proportional control valve that prevents the cap from falling off.