CN117128321A - proportional control valve - Google Patents

Abstract

The invention provides a proportional control valve, which can restrain the change of the pressure (secondary pressure) at the downstream side relative to the change of the pressure (primary pressure) at the upstream side, thereby realizing the miniaturization, the overall miniaturization and the light weight of a driving source. The invention comprises the following steps: a housing (10) including an upstream chamber (11 b) and a downstream chamber (11 d) through which a fluid passes, and a valve interposed between the upstream chamber and the downstream chamberA seat (11 a); a first diaphragm (20) acting on the front surface (21 a) with the pressure (P1) of the upstream chamber ₁ ) And the pressure (P2) of the downstream chamber acts on the back surface (21 a ₂ ) Is configured in the shell; a second diaphragm (30) acting on the front surface (31 a) with the pressure (P2) of the downstream chamber ₁ ) And atmospheric pressure acts on the back surface (31 a) ₂ ) Is configured in the shell; a valve body (40) that moves in conjunction with the first diaphragm and the second diaphragm so as to be capable of being seated on and unseated from the valve seat (11 a); and a drive unit (Du) for applying a drive force to the valve body.

Description

Proportional control valve

Technical Field

The present invention relates to a proportional control valve for proportionally controlling the opening of a valve body for opening and closing a fluid passage, and more particularly, to a proportional control valve used for adjusting the flow rate of gas when the valve is incorporated in a system of a gas hot water supply device.

Background

As conventional proportional control valves, the following gas proportional valves are known: as shown in fig. 12, includes: a housing (case) 1 defining an inlet chamber 1a, an outlet chamber 1b, and a valve seat 1c located between the inlet chamber 1a and the outlet chamber 1 b; a diaphragm 2 that closes a surface of the inlet chamber 1a opposite to the valve seat 1c; a valve body 3 that reciprocates integrally with the diaphragm 2 and is capable of being seated on the valve seat 1c; a solenoid 4 including a movable iron core 4a for reciprocally driving the valve body 3; and a spring 5 for canceling the self weight of the valve body 3 and the movable iron core 4a (for example, refer to patent document 1).

In the gas proportional valve having the above-described structure, in general, in order to maintain the pressure (secondary pressure P2) of the outlet chamber 1b constant with respect to the pressure (primary pressure P1) of the inlet chamber 1a, the effective area Av of the valve body 3 and the effective area Ad of the diaphragm 2 are set to be identical in design.

For example, when the force in the valve opening direction of the solenoid 4 is F, the balance of the force in the movement direction of the valve body 3 becomes f+av·p1=ad·p1+av·p2. If the formulas are sorted, p2= [ f+ (Av-Ad) ·p1]/Av is obtained.

Therefore, if the effective area Av of the valve body 3 is the same as the effective area Ad of the diaphragm 2, the secondary pressure P2 can be maintained constant regardless of the primary pressure P1.

However, in the gas proportional valve having the above-described structure, the diaphragm 2 is formed of a flexible material that is elastically deformable, and the diaphragm 2 is attached by sandwiching the outer peripheral edge portion by two members, and therefore, the effective diameter defining the effective area Ad of the diaphragm 2 may vary due to dimensional variations of the respective components or variations in assembly positions, and a predetermined effective area Ad may not be obtained. As a result, there is a concern that the change in the secondary pressure P2 increases with respect to the change in the primary pressure P1.

In the conventional gas proportional valve, as shown in fig. 13, as the outer diameter (effective diameter) of the valve body is reduced, the load balanced with the secondary pressure P2 is reduced, and therefore even a small load change causes a large change in the secondary pressure. Therefore, it is difficult to achieve miniaturization of the valve body and the solenoid, and miniaturization and weight reduction of the entire gas proportional valve.

[ Prior Art literature ]

[ patent literature ]

Patent document 1 Japanese patent laid-open No. 2007-162911

Disclosure of Invention

[ problem to be solved by the invention ]

The present invention has been made in view of the above circumstances, and an object thereof is to provide a proportional control valve capable of reducing the diameter of a valve body, reducing the size of a drive source, reducing the size of the whole, and reducing the weight of the valve body, without increasing the dimensional accuracy or assembly accuracy of each component, and suppressing the change in pressure (secondary pressure) on the downstream side with respect to the change in pressure (primary pressure) on the upstream side of the valve body.

[ means of solving the problems ]

The proportional control valve of the present invention includes: a housing including an upstream chamber and a downstream chamber through which a fluid passes, and a valve seat interposed between the upstream chamber and the downstream chamber; a first diaphragm disposed in the housing such that pressure in the upstream chamber acts on the front surface and pressure in the downstream chamber acts on the back surface; a second diaphragm disposed in the housing such that the pressure of the downstream chamber acts on the front surface and the atmospheric pressure acts on the back surface; a valve body that moves in conjunction with the first diaphragm and the second diaphragm so as to be capable of being seated on and unseated from the valve seat; and a drive source for applying a drive force to the valve body.

In the proportional control valve, the following structure may be adopted:

the pressure in the upstream chamber is set to P1, the pressure in the downstream chamber is set to P2, and the effective area of the first diaphragm is set to Ad ₁ The effective area of the second diaphragm is set as Ad ₂ Setting the effective area of the valve body as Av and drivingWhen the driving force of the source is F, the balance of the forces in the moving direction of the valve body is satisfied

P2＝[F+(Ad ₁ -Av)·P1]/(Ad ₂ +Ad ₁ -Av)。

In the proportional control valve, the following structure may be adopted: effective area Ad of first diaphragm ₁ Effective area Ad of second diaphragm ₂ Is formed to satisfy Ad ₂ /Ad ₁ ＞1。

In the proportional control valve, the following structure may be adopted: the valve body includes: a valve portion including a conical surface that tapers toward a front end of the downstream chamber so as to be able to contact the valve seat; and a rod portion connected to the first diaphragm and the second diaphragm.

In the proportional control valve, the following structure may be adopted: the housing includes a back pressure chamber on a back surface of the first diaphragm, and the valve body includes a communication passage that communicates the downstream chamber with the back pressure chamber.

In the proportional control valve, the following structure may be adopted: the driving source is a solenoid including a movable iron core engaged with the valve body and an exciting coil disposed around the movable iron core.

In the proportional control valve, the following structure may be adopted: the valve body is disposed so as to move in the vertical direction and is seated on the valve seat by its own weight.

In the proportional control valve, the following structure may be adopted: comprises a force application member for applying force to the movable iron core towards the valve body.

In the proportional control valve, the following structure may be adopted: the upstream chamber is disposed above the valve seat, and the downstream chamber is disposed below the valve seat.

In the proportional control valve, the following structure may be adopted: the housing includes: a housing body defining an upstream chamber, a downstream chamber, a valve seat, and a first opening for opening the upstream chamber and a second opening for opening the downstream chamber, respectively, on both outer sides in a moving direction of the valve body; a first case cover that covers a first diaphragm disposed so as to close the first opening from the outside; and a second case cover that covers the second diaphragm disposed so as to close the second opening from the outside.

In the proportional control valve, the following structure may be adopted: the valve body is disposed so as to move in the vertical direction and to be seated on the valve seat by its own weight, the upstream chamber is disposed above the valve seat, and the downstream chamber is disposed below the valve seat.

In the proportional control valve, the following structure may be adopted: the housing body includes an inlet for fluid communication with the upstream chamber and an outlet for fluid communication with the downstream chamber, the inlet and the outlet being disposed at the same height in the direction of movement of the valve body.

In the proportional control valve, the following structure may be adopted: the first housing cover defines a back pressure chamber facing a back surface of the first diaphragm, and the valve body includes a communication passage that communicates the downstream chamber with the back pressure chamber.

In the proportional control valve, the following structure may be adopted: the second housing cover includes an open aperture that opens the back surface of the second diaphragm to the atmosphere.

[ Effect of the invention ]

By forming the proportional control valve having the above-described structure, the change in the pressure (secondary pressure) on the downstream side with respect to the change in the pressure (primary pressure) on the upstream side of the valve body can be suppressed without increasing the dimensional accuracy or assembly accuracy of the respective components, and the reduction in the diameter of the valve body, the reduction in the size of the drive source, and the reduction in the size and weight of the whole can be achieved.

Drawings

Fig. 1 is an external perspective view showing a proportional control valve according to an embodiment of the present invention, and is a perspective view from above obliquely.

Fig. 2 is an external perspective view of the proportional control valve according to the embodiment as seen obliquely from below.

Fig. 3 is an external perspective view of a driving unit included in the proportional control valve of an embodiment.

Fig. 4 is a perspective cross-sectional view of the proportional control valve according to the embodiment, taken along a plane including an axis extending in the vertical direction and a straight line passing through the centers of the fluid inlet and outlet.

Fig. 5 is a longitudinal sectional view of the proportional control valve according to the embodiment, taken along a plane including an axis extending in the vertical direction and a straight line passing through the centers of the inlet and the outlet of the fluid.

Fig. 6 is a longitudinal sectional view of the proportional control valve according to the embodiment, taken along a plane including an axis extending in the vertical direction and perpendicular to a straight line passing through the centers of the fluid inlet and outlet.

Fig. 7 is an external perspective view of a housing body constituting a housing in the proportional control valve according to the embodiment, as viewed obliquely from above.

Fig. 8 is an external perspective view of a housing body constituting a housing in the proportional control valve according to the embodiment, as viewed obliquely from below.

Fig. 9 is a schematic diagram showing pressure, effective area, driving force, and the like associated with balance of forces in the moving direction of the valve body in the proportional control valve of the embodiment.

FIG. 10 is a graph showing the ratio (Ad) of the effective area of the first diaphragm to the effective area of the second diaphragm in the proportional control valve of the present invention ₂ /Ad ₁ ) A graph of the relationship with the change (Δp2) in the pressure (secondary pressure) of the downstream chamber.

Fig. 11 is a graph showing a relationship between the pressure of the upstream chamber (primary pressure P1) and the pressure of the downstream chamber (secondary pressure P2) in the proportional control valve of the present invention.

Fig. 12 is a sectional view showing the structure of a conventional proportional control valve.

Fig. 13 is a graph showing a relationship between an outer diameter (effective diameter) of a valve body and a change (Δp2) in pressure (secondary pressure) on a downstream side in a conventional proportional control valve.

[ description of symbols ]

S: an axis line

Vd: in the vertical direction

Vu: valve unit

Du: driving unit (Driving source)

F: driving force of driving source

10: shell body

11: shell body (Shell)

11a: valve seat

11a ₁ : round hole

D: the inner diameter of the round hole defined by the valve seat

11b: upstream chamber

P1: pressure in upstream chamber

11c: an inlet

11d: downstream chamber

P2: pressure in downstream chamber

11e: an outlet

11f: a first opening part

11j: a second opening part

12: first shell cover (Shell)

Bc ₁ : back pressure chamber

13: second housing cover (Shell)

Bc ₂ : back pressure chamber

13e: open hole

20: first diaphragm

21a ₁ : front surface

21a ₂ : back surface

Ad ₁ : effective area of the first diaphragm

30: second diaphragm

31a ₁ : front surface

31a ₂ : back surface

Ad ₂ : effective area of the second diaphragm

40: valve body

40a: communication path

41: valve part

41a: annular conical surface

Av: effective area of valve body

42: rod part

42a: upper shaft (rod)

42b: chimeric shaft (rod)

42c: lower shaft (rod)

42d: chimeric shaft (rod)

50: frame member (Driving source)

51: outer magnetic yoke (frame component)

52: inner magnetic yoke (frame component)

53: end yoke (frame component)

60: sleeve (Driving source)

70: movable iron core (solenoid, driving source)

80: exciting coil (solenoid, driving source)

90: spring (force application component)

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The proportional control valve according to one embodiment is, for example, incorporated in a system of a gas hot water supply device, and controls the flow rate of a gas fluid, and includes a valve unit Vu and a drive unit Du as a drive source, as shown in fig. 1 to 3.

The valve unit Vu includes: a housing 10, a first diaphragm 20, a second diaphragm 30, and a valve body 40.

The driving unit Du includes: the frame member 50, the sleeve 60, the movable iron core 70, the exciting coil 80, and the spring 90 as the urging member.

The proportional control valve is assembled to the gas water heater such that the axis S, which is the moving direction of the valve body 40 and the movable iron core 70, is oriented in the vertical direction Vd, the valve body 40 is disposed on the upper side, and the movable iron core 70 is disposed on the lower side.

The case 10 includes a case body 11, a first case cover 12, and a second case cover 13, the case body 11 is formed using a metal material such as aluminum, and the first case cover 12 and the second case cover 13 are formed by press forming using a metal material such as stainless steel plate.

As shown in fig. 1, 2, and 4 to 8, the housing body 11 includes: a valve seat 11a, an upstream chamber 11b, an inlet 11c, a downstream chamber 11d, an outlet 11e, a first opening 11f, a first annular groove 11g, a first annular recess 11h, two screw holes 11i, a second opening 11j, a second annular groove 11k, a second annular recess 11m, and two protrusions 11n, each having a hexahedral profile and centered on the axis S.

The valve seat 11a is a circular hole 11a defining an inner diameter D centered on the axis S as a passage for fluid ₁ And shaped likeThe valve portion 41 of the valve body 40 is formed in an annular shape and is detachably seated in the axis S direction. Here, as shown in fig. 9, the inner diameter D defines the effective diameter of the valve body 40.

The upstream chamber 11b is a passage through which fluid passes, and is formed above the valve seat 11a in the vertical direction Vd on the upstream side of the valve seat 11a.

The inlet 11C is formed as a circular hole having a center on a straight line C perpendicular to the axis S for allowing the fluid to flow into the housing 10.

The downstream chamber 11d is a passage through which fluid passes, and is formed below the valve seat 11a in the vertical direction Vd on the downstream side of the valve seat 11a.

The outlet 11e is formed as a circular hole having a center on a straight line C perpendicular to the axis S in order to allow the fluid to flow out of the housing 10.

The inlet 11c and the outlet 11e are connected to the middle of the gas supply pipe in the gas hot water supply system.

The inlet 11C and the outlet 11e are arranged on a straight line C, that is, at the same height in the moving direction (axis S direction) of the valve body 40. Thereby, the housing body 11 can be reduced in size in the direction of the axis S, contributing to miniaturization.

The first opening 11f is formed as a circular hole that opens the upstream chamber 11b toward the axis S direction, that is, one side of the movement direction of the valve body 40. Further, the first opening 11f is closed by the first diaphragm 20.

The first annular groove 11g is formed in an annular shape recessed outward in the axis S direction around the first opening 11f so as to fit the outer peripheral edge 21b of the first diaphragm 20.

The first annular recess 11h is formed adjacent to the outside of the first annular groove 11g in the axis S direction, and is formed so as to fit in the annular portion 12b of the first case cover 12.

The two screw holes 11i are formed to screw in a screw b1 for fastening and fixing the first housing cover 12.

The second opening 11j is formed as a circular hole that opens the downstream chamber 11d toward the other side of the axis S direction, i.e., the moving direction of the valve body 40. Further, the second opening 11j is blocked by the second diaphragm 30.

The second annular groove 11k is formed in an annular shape recessed outward in the axis S direction around the second opening 11j so as to fit the outer peripheral edge 31b of the second diaphragm 30.

The second annular recess 11m is formed adjacent to the outer side of the second annular groove 11k in the axis S direction, and is formed so as to be fitted with the annular portion 13a of the second case cover 13.

The two bosses 11n are formed in a columnar shape protruding outward in the axis S direction, and are formed to screw in a screw b2 for fastening and fixing the frame member 50 (the outer yoke 51) of the drive unit Du.

As shown in fig. 1, 4 to 6, the first housing cover 12 includes: flange 12a, annular portion 12b, and bottomed cylindrical portion 12c.

The flange portion 12a is a region joined to the end surface of the housing body 11 in the axial direction S, and includes two circular holes 12a through which the screws b1 pass ₁ 。

The annular portion 12b is formed to fit into the first annular recess 11h of the housing body 11 so as to press the outer peripheral edge portion 21b of the first diaphragm 20 toward the first annular groove 11 g.

The bottomed cylindrical portion 12c is formed to include a bottom wall protruding outward and a cylindrical wall centered on the axis S, and defines a back face 21a of the first diaphragm 20 ₂ The back pressure chamber Bc facing ₁ 。

The first housing cover 12 is joined to the housing body 11 by a screw b1 so as to press-fix the outer peripheral edge portion 21b of the first diaphragm 20 and cover the first diaphragm 20 from the outside in the axis S direction in a state where the first diaphragm 20 is connected to the valve body 40 so as to close the first opening 11f of the housing body 11.

As shown in fig. 2, 4 to 6, the second housing cover 13 includes: the annular portion 13a, the annular recess 13b, the fitting recess 13c, the central opening 13d, and the open hole 13e.

The annular portion 13a is formed to fit into the second annular recess 11m of the housing body 11 so as to press the outer peripheral edge portion 31b of the second diaphragm 30 toward the second annular groove 11 k.

The annular recess 13b is formed as an annular recess centered on the axis S and defines the back surface 31a of the second diaphragm 30 ₂ The back pressure chamber Bc facing ₂ . The outer surface of the annular recess 13b is formed as a flat surface perpendicular to the axis S, and is pressed inward in the axis S direction by the outer yoke 51 of the frame member 50 included in the drive unit Du.

The fitting recess 13c defines an inner cylindrical surface centered on the axis S, and is formed to fit the sleeve 60 of the drive unit Du via the O-ring R1.

The central opening 13d is formed as a circular hole centered on the axis S, and the fitting shaft 42d of the valve body 40 is inserted in a non-contact manner, that is, with a predetermined gap therebetween.

The opening hole 13e is formed to allow atmospheric pressure to act on the back surface 31a of the second diaphragm 30 ₂ Via the recess 51a of the frame member 50 (outer yoke 51) ₂ Back pressure chamber Bc ₂ Open to the atmosphere.

Further, the second housing cover 13 is held by: in a state where the second diaphragm 30 is connected to the valve body 40 so as to close the second opening 11j of the case body 11, the outer peripheral edge 31b of the second diaphragm 30 is pressed and fixed, and is joined to the case body 11 so as to cover the second diaphragm 30 from the outside in the axis S direction, pressed by the outer yoke 51 of the frame member 50, and the outer yoke 51 is fastened and fixed by the screw b 2.

As shown in fig. 4 to 6, the first diaphragm 20 includes a rubber disk 21 formed of a rubber material capable of elastic deformation, and a fixing cap 22.

The rubber disk 21 includes: an elastically deformable annular film portion 21a, an outer peripheral edge portion 21b fitted into the first annular groove portion 11g of the housing body 11, and a central portion 21c.

The annular membrane portion 21a is formed in an elastically deformable film and is formed in an annular shape centered on the axis S, and includes a front surface 21a facing the upstream chamber 11b ₁ Facing the back pressure chamber Bc ₁ Back surface 21a of (2) ₂ 。

The outer peripheral edge portion 21b is formed in an annular shape centered on the axis S, and has a wall thickness of a dimension higher than the groove depth of the first annular groove portion 11 g.

The central portion 21c defines a fitting hole centered on the axis S for fitting the fitting shaft portion 42b of the valve body 40, and is formed in a cylindrical shape having a thicker wall thickness than the outer peripheral portion 21 b.

The fixing cap 22 is formed to press and fix the central portion 21c of the rubber disk 21 to the fitting shaft portion 42b of the valve body 40, and to abut against the inner wall surface of the first housing cover 12 to define the fully open position of the valve body 40.

That is, the first diaphragm 20 is disposed in the housing 10 on the upstream side of the valve seat 11a so as to close to the upstream chamber 11b and close the first opening 11f, and is linked to the valve body 40 moving in the axis S direction, and the pressure (primary pressure P1) of the upstream chamber 11b acts on the front surface 21a ₁ The pressure (secondary pressure P2) of the downstream chamber 11d acts on the back surface 21a through the communication path 40a of the valve body 40 ₂ 。

The first diaphragm 20 functions to regulate the pressure according to the fluctuation of the pressure P1 in the upstream chamber 11b and the pressure P2 in the downstream chamber 11 d.

As shown in fig. 4 to 6, the second diaphragm 30 includes a rubber disk 31 formed of a rubber material capable of elastic deformation, and a fixed disk 32.

The rubber disk 31 includes: an elastically deformable annular film portion 31a, an outer peripheral edge portion 31b fitted into the second annular groove portion 11k of the housing body 11, and a central portion 31c.

The annular membrane portion 31a is a film capable of elastic deformation and is formed in an annular shape centered on the axis S, and includes a front surface 31a facing the downstream chamber 11d ₁ Facing the back pressure chamber Bc ₂ Back face 31a of (a) ₂ 。

The outer peripheral edge 31b is formed in an annular shape centered on the axis S, and has a wall thickness of a dimension higher than the groove depth of the second annular groove 11 k.

The central portion 31c is formed to include a circular plate portion 31c ₁ And a cylindrical portion 31c ₂ The cylindrical portion 31c ₂ The fitting shaft portion 42d of the valve body 40 defines a fitting hole centered on the axis S and has a thicker wall thickness than the outer peripheral portion 31 b.

The fixed disk 32 and the rubber disk 31The region of the central portion 31c is adjacently arranged and formed to hold the disk portion 31c ₁ And the cylindrical portion 31c ₂ A fitting shaft 42d fixed to the valve body 40.

That is, the second diaphragm 30 is disposed in the housing 10 so as to close the downstream chamber 11d on the downstream side of the valve seat 11a and to close the second opening 11j, and is linked to the valve body 40 moving in the axis S direction, and the pressure (secondary pressure P2) of the downstream chamber 11d acts on the front surface 31a ₁ Atmospheric pressure acts on the back surface 31a through the open hole 13e of the second housing cover 13 ₂ 。

The second diaphragm 30 also functions to regulate the pressure according to the fluctuation of the pressure P2 in the downstream chamber 11 d.

The valve body 40 is formed as a poppet valve, and includes a valve portion 41, and a stem portion 42 extending from the valve portion 41 in the direction of the axis S.

The valve portion 41 is formed in a substantially truncated cone shape centered on the axis S, and includes an annular tapered surface 41a having a tip end that is thin and convexly curved toward the downstream chamber 11d so as to be able to contact the valve seat 11a in the outer peripheral region.

The rod 42 is formed in a cylindrical shape centered on the axis S, and includes: an upper shaft portion 42a, a fitting shaft portion 42b, a lower shaft portion 42c, and a fitting shaft portion 42d.

In addition, the valve body 40 includes a communication passage 40a, the communication passage 40a extending from a region adjacent to the downstream chamber 11d to a region adjacent to the back surface 21a of the first diaphragm 20 ₂ The back pressure chamber Bc facing ₁ The downstream chamber 11d and the back pressure chamber Bc ₁ And (5) communication.

The upper shaft portion 42a is formed in a cylindrical shape extending outward (upward) in the axis S direction from the valve portion 41 in the upstream chamber 11 b.

The fitting shaft portion 42b is continuous with the upper shaft portion 42a in the axis S direction and has a multistage outer diameter smaller than that of the upper shaft portion 42a, and is formed so as to be fitted to the central portion 21c of the rubber disk 21 of the first diaphragm 20 and to be fitted to the fixing cap 22. The fitting shaft portion 42b may be integrally formed with the upper shaft portion 42a, or may be separately formed and then coupled to the upper shaft portion 42a.

The lower shaft portion 42c has the same outer diameter as the upper shaft portion 42a, and is formed in a cylindrical shape extending inward (downward) in the axis S direction from the valve portion 41 in the downstream chamber 11 d.

The fitting shaft portion 42d is integrally formed with the lower shaft portion 42c so as to be continuous with the lower shaft portion 42c in the axis S direction and to have a multistage outer diameter smaller than that of the lower shaft portion 42 c. Further, a central portion 31c (cylindrical portion 31 c) of the rubber disk 31 of the second diaphragm 30 is fitted in the fitting shaft portion 42d ₂ ) And a fixing plate 32 is fitted. The region on the distal end side of the fitting shaft portion 42d is inserted into the central opening portion 13d of the second housing cover 13, and the end portion 42d thereof ₁ The movable iron core 70 of the driving unit Du is detachably contacted.

That is, the valve body 40 moves in the direction of the axis S so as to be capable of being seated on and unseated from the valve seat 11a while being linked to the first diaphragm 20 and the second diaphragm 30, and the driving force of the movable iron core 70 is imparted in the direction of the axis S.

The frame member 50 is formed of soft iron or the like, functions as a magnetic circuit passing through magnetic lines of force, and includes an outer yoke 51, an inner yoke 52, and an end yoke 53.

The outer yoke 51 is formed by bending into a substantially コ shape, and includes: fitting hole 51a defined on axis S ₁ Recess 51a ₂ A flat plate portion 51a of (1), two leg portions 51b, a circular hole 51c extending from the flat plate portion 51a and through which the screw b2 passes ₁ Is provided with two flange portions 51c and two connecting portions 51d.

The inner yoke 52 includes: a substantially rectangular flat plate portion 52a; a cylindrical portion 52b continuous with the flat plate portion 52a and defining a fitting hole 52b on the axis S ₁ And a bobbin 81 is fitted to the outer peripheral surface; the two connecting portions 52c are connected to the connecting portion 51d of the outer yoke 51.

The end yoke 53 includes: a substantially rectangular flat plate portion 53a, a bottomed cylindrical portion 53b having a two-stage diameter centered on the axis S, and two coupling portions 53c coupled to the coupling portion 51d of the outer yoke 51.

The sleeve 60 is formed in a cylindrical shape centering on the axis S using a metal material such as stainless steel, and serves to guide the movable iron core 70 slidably in the axis S direction.

Furthermore, the processing unit is configured to,fitting hole 51a of sleeve 60 and outer yoke 51 ₁ Fitting hole 52b of inner yoke 52 ₁ The upper end region is fitted into the fitting recess 13c of the second housing cover 13 via the O-ring R1, and the lower end region is fitted into the bottomed cylindrical portion 53b of the end yoke 53 via the O-ring R2.

Thereby, the sleeve 60 slidably guides the movable iron core 70 in the axis S direction.

The movable iron core 70 has a cylindrical shape extending in the axis S direction, is slidably disposed in the sleeve 60, and includes an upper end contact portion 71 and a lower end spring receiving portion 72.

The upper end contact portion 71 is formed as a circular flat surface and is engaged with the end portion 42d of the fitting shaft portion 42d of the valve body 40 ₁ Can be in contact with the ground in a detachable manner.

The lower end spring receiving portion 72 is formed as a flat surface at the bottom of the annular recess, and receives the upper end portion of the spring 90 in the axis S direction.

That is, the movable iron core 70 engages with the valve body 40 in the axis S direction to apply a driving force.

The exciting coil 80 is wound around a resin bobbin 81 held by the outer yoke 51 and the inner yoke 52 with the axis S as the center.

The bobbin 81 is integrally molded with two terminals 81a extending from the exciting coil 80.

The spring 90 is a compression-type coil spring, and is disposed inside the sleeve 60 so as to urge the movable iron core 70 in the axis S direction toward the valve body 40, with an upper end 91 abutting against the lower end spring receiving portion 72 of the movable iron core 70, and a lower end 92 abutting against the bottom wall of the bottomed cylindrical portion 53b of the end yoke 53, and expanding in the axis S direction.

Moreover, the spring 90 functions as follows: in the axis S direction (vertical direction Vd), the valve body 40, the first diaphragm 20, the second diaphragm 30, and the movable iron core 70 are supported so as to substantially cancel the weight of the valve body 40, and the movable iron core 70 is biased upward in the vertical direction Vd so that the valve body 40 is positioned at the rest position where the valve seat 11a is seated by its own weight.

In the proportional control valve forming the structure, as shown in the figure9, the effective area of the first diaphragm 20 is Ad, assuming that the pressure (primary pressure) of the upstream chamber 11b of the housing 10 is P1, the pressure (secondary pressure) of the downstream chamber 11d is P2 ₁ The effective area of the second diaphragm 30 is set to Ad ₂ When Av is the effective area of the valve body 40 and F is the driving force of the driving unit Du (the movable iron core 70), the balance equation of the force in the moving direction (the axis S direction) of the valve body 40 is:

in the direction of axis S

Upward force = downward force

F+Av·P2+Ad ₁ ·P1＝Ad ₂ ·P2+Av·P1+Ad ₁ ·P2

If the formulas are sorted for P1 and P2,

then become (Ad) ₂ +Ad ₁ -Av)·P2＝F+(Ad ₁ -Av)·P1，

Regarding the function of the pressure P1 as an input variable and the pressure P2 as an output variable,

to obtain P2= [ F+ (Ad) ₁ -Av)·P1]/(Ad ₂ +Ad ₁ -Av)···(a)。

Here, the effective area Ad ₁ Effective area Av, effective area Ad ₂ The area calculated from the effective diameter of the surface on which the pressure P1 and the pressure P2 act as thrust force. The effective diameter is the diameter of the surface that receives the pressure P1 and the pressure P2 and acts effectively as thrust.

In addition, the effective area Ad of the first diaphragm 20 ₁ The effective area Av of the valve body 40 is preferably set to the same value in terms of design, but both are approximate values due to dimensional variations and assembly variations of the respective components.

That is, the proportional control valve forming the structure is formed so as to satisfy the functional formula (a).

In addition, in the proportional control valve forming the above-described structure, the change in the pressure P2 of the downstream chamber 11d (the change amount Δp2) is relative to the effective area Ad of the second diaphragm 30 ₂ Effective area Ad with first diaphragm 20 ₁ Ratio (Ad) ₂ /Ad ₁ ) The relationship of (2) can be taken as that of FIG. 10The graph shown.

That is, the pressure (secondary pressure) P2 of the downstream chamber 11d is obtained with respect to Ad ₂ /Ad ₁ A relation in which the value of (2) is gradually changed. In particular, with Ad ₂ /Ad ₁ The value of (a) becomes larger, and the amount of change Δp2 of the pressure (secondary pressure) P2 of the downstream chamber 11d becomes smaller.

That is, in the proportional control valve of the present invention, as shown in fig. 11, the change (Δp2) in the pressure (secondary pressure) P2 of the downstream chamber 11d can be reduced with respect to the change in the pressure (primary pressure) P1 of the upstream chamber 11b, as compared with the conventional proportional control valve. Accordingly, the pressure P2 in the downstream chamber 11d can be controlled to approach a desired constant value.

Here, in the effective area Ad of the second separator 30 ₂ Effective area Ad with first diaphragm 20 ₁ Ratio (Ad) ₂ /Ad ₁ ) In the case of the study, it was assumed that Ad was used ₂ /Ad ₁ ＝1(Ad ₂ ＝Ad ₁ ) In the case of (a), the relational expression (a) is replaced with

P2＝[F+(Ad ₁ -Av)·P1]/(Ad ₁ +Ad ₁ -Av)，

Due to Ad ₁ Is substantially the same as Av (approximate value), and thus can be expressed as the following approximate expression

P2＝[F+(Ad ₁ -Av)·P1]/Ad ₁ The approximation is equal to

In the conventional proportional control valve, the relation between P1 and P2, p2= [ f+ (Av-Ad) ·p1]Av, etc. Thus, ad ₂ /Ad ₁ Preferably a value of greater than 1.

That is, in the proportional control valve forming the structure, the effective area Ad of the first diaphragm 20 ₁ Effective area Ad with second diaphragm 30 ₂ Is preferably formed to satisfy Ad ₂ /Ad ₁ > 1. More preferably formed to satisfy Ad ₂ /Ad ₁ ＞2。

Next, an operation of the proportional control valve in a state of being assembled in a system of the gas hot water supply device will be described.

First, in a state where the operation is stopped, control valves (not shown) disposed on the upstream side and the downstream side of the proportional control valve are closed, the exciting coil 80 is not energized, and the valve body 40 is positioned at a rest position where the valve seat 11a is seated and closed as shown in fig. 5.

When a start signal of the combustion operation is issued from this stopped state by the control device, the control valve is suitably opened, and the exciting coil 80 is energized, so that the driving force F of the movable iron core 70 acts, and the valve body 40 is lifted from the valve seat 11a to open the valve.

Then, the energization of the exciting coil 80 is controlled by pulse width modulation (Pulse width modulation, PWM) in accordance with the control signal, and the valve opening degree is adjusted to a desired value.

When the valve body 40 reaches the maximum lift, the fixing cap 22 abuts against the inner wall surface of the first housing cover 12, and further movement is restricted.

On the other hand, when the control device sends a signal to stop combustion, the control valve is closed, and the exciting coil 80 is not energized, so that the driving force F of the movable iron core 70 no longer acts, and the valve body 40 is seated on the valve seat 11a by its own weight, thereby closing the valve.

As described above, the proportional control valve according to the present invention is configured to include: a housing 10 including an upstream chamber 11b and a downstream chamber 11d through which a fluid passes, and a valve seat 11a interposed between the upstream chamber 11b and the downstream chamber 11 d; a first diaphragm 20 acting on the front surface 21a with the pressure of the upstream chamber 11b ₁ And the pressure of the downstream chamber 11d acts on the back surface 21a ₂ Is disposed in the housing 10; a second diaphragm 30 acting on the front surface 31a with the pressure of the downstream chamber 11d ₁ And atmospheric pressure acts on the back surface 31a ₂ Is disposed in the housing 10; a valve body 40 that moves in association with the first diaphragm 20 and the second diaphragm 30 and is capable of being seated on and unseated from the valve seat 11a; and a drive source (drive unit Du) that applies a drive force to the valve body 40.

In particular, the pressure in the upstream chamber 11b is P1, the pressure in the downstream chamber 11d is P2, and the effective area of the first diaphragm 20 is Ad ₁ The effective area of the second diaphragm 30 is set to Ad ₂ When Av is the effective area of the valve body 40 and F is the driving force of the driving source (driving unit Du)The balance of forces in the moving direction (axis S direction) of the valve body 40 is formed so as to satisfy p2= [ f+ (Ad) ₁ -Av)·P1]/(Ad ₂ +Ad ₁ -Av)。

In addition, the effective area Ad of the first diaphragm 20 ₁ Effective area Ad of second diaphragm 30 ₂ Is formed to satisfy Ad ₂ /Ad ₁ ＞1。

Accordingly, without increasing the dimensional accuracy or assembly accuracy of the respective components, the variation of the downstream pressure (secondary pressure) P2 with respect to the variation of the upstream pressure (primary pressure) P1 of the valve body 40 can be suppressed as compared with the conventional one, and the valve body 40 can be miniaturized, so that the miniaturization of the drive source (drive unit Du), the miniaturization of the whole, and the weight saving can be realized.

In addition, according to the proportional control valve of the present invention, the valve body 40 is constituted to include: the valve portion 41 includes an annular tapered surface 41a that is tapered toward the tip of the downstream chamber 11d so as to be able to contact the valve seat 11a; and a stem 42 connected to the first diaphragm 20 and the second diaphragm 30.

Accordingly, in the structure in which the valve body 40 is moved in the vertical direction Vd and the driving force F is applied from below in the vertical direction Vd, two diaphragms (the first diaphragm 20 and the second diaphragm 30) that are linked with the valve body 40 can be easily arranged so as to satisfy the above-described balance.

In addition, the housing 10 includes a back surface 21a of the first diaphragm 20 ₂ The back pressure chamber Bc facing ₁ The valve body 40 includes a downstream chamber 11d and a back pressure chamber Bc ₁ A communication path 40a for communicating.

Accordingly, the valve body 40 can be reduced in weight and simplified in structure.

In the proportional control valve according to the present invention, the drive source (drive means Du) is a solenoid including the movable iron core 70 engaged with the valve body 40 and the exciting coil 80 disposed around the movable iron core 70, and is disposed so that the valve body 40 moves in the vertical direction Vd and is seated on the valve seat 11a by its own weight.

Accordingly, a desired driving force can be easily obtained, and the exciting coil 80 is in a non-energized state and the valve body 40 can be held in the valve-closing position by a simple structure.

Further, since the movable iron core 70 is provided with the urging member (spring 90) for urging the movable iron core 70 toward the valve body 40, the urging force that counteracts the weight of the valve body 40, the movable iron core 70, and the like can be brought about by the urging member (spring 90), and the driving force can be reduced accordingly.

In the proportional control valve according to the present invention, the upstream chamber 11b is disposed above the valve seat 11a in the case 10, the downstream chamber 11d is disposed below the valve seat 11a, and the present invention can be easily established in a configuration in which the valve body 40 moves in the vertical direction Vd.

In addition, according to the proportional control valve of the present invention, the housing 10 is configured to include: a housing body 11 defining an upstream chamber 11b, a downstream chamber 11d, a valve seat 11a, and a first opening 11f for opening the upstream chamber 11b and a second opening 11j for opening the downstream chamber 11d, respectively, on both outer sides in the moving direction of the valve body 40; a first case cover 12 that covers the first diaphragm 20 disposed so as to close the first opening 11f from the outside; and a second case cover 12 that covers the second diaphragm 30 disposed so as to close the second opening 11j from the outside.

Accordingly, the assembly work of the components is easy, and the disassembly work can be easily performed as needed.

In addition, according to the proportional control valve of the present invention, since the inlet 11c and the outlet 11e are disposed at the same height in the moving direction (axis S direction) of the valve body 40 in the case body 11, the case body 11 in the axis S direction can be thinned, and the entire proportional control valve can be miniaturized.

In particular, the first housing cover 12 defines a back face 21a of the first diaphragm 20 ₂ The back pressure chamber Bc facing ₁ The second housing cover 13 includes a back surface 31a for sealing the second diaphragm 30 ₂ The open hole 13e that is open to the atmosphere can therefore simplify the structure of the housing body 11.

In the above embodiment, the proportional control valve including the spring 90 for biasing the movable core 70 upward in the vertical direction Vd is shown in the structure in which the valve body 40 moves in the vertical direction Vd and is seated on the valve seat 11a by its own weight, but the present invention is not limited thereto.

For example, in the above embodiment, the valve body 40 is moved upward from the lower side to the upper side to be seated on the valve seat 11a to close the valve, and the movable iron core 70 applies a driving force downward from the upper side of the valve body 40, which is a structure opposite to the upper side and the lower side, and the valve body is disposed in the back pressure chamber Bc ₁ The present invention can be similarly applied to a form of a biasing member (coil spring) for biasing the lower end portion of the inner valve body 40 upward in the vertical direction Vd.

In the above embodiment, the solenoid including the movable iron core 70 and the exciting coil 80 engaged with the valve body 40 is shown as the driving source for applying the driving force to the valve body 40, but the present invention is not limited thereto, and for example, the following driving source may be employed: the valve body is disposed in a non-contact manner with the fixed iron core, and a magnet generating a repulsive force with a solenoid including the fixed iron core and the exciting coil is provided on the valve body to apply a driving force to the valve body.

In the above embodiment, the case 10 including the case body 11, the first case cover 12, and the second case cover 13 is shown as the case defining the upstream chamber, the downstream chamber, and the valve seat as the passages of the fluid, but the present invention is not limited thereto, and cases in other forms may be used.

In the embodiment, it is shown that the back surface 21a of the first diaphragm 20 is acted on by the pressure P2 of the downstream chamber 11d ₂ The valve body 40 is provided with a downstream chamber 11d and a back pressure chamber Bc ₁ The structure of the communication passage 40a is not limited to this, and the communication passage may be provided in the housing body.

As described above, the proportional control valve according to the present invention can suppress the change in the pressure (secondary pressure) on the downstream side with respect to the change in the pressure (primary pressure) on the upstream side without increasing the dimensional accuracy or assembly accuracy of each component, and can achieve the downsizing of the valve body, the downsizing of the drive source, the downsizing of the whole, and the weight reduction, and therefore, it is needless to say, it can be applied as a proportional control valve for controlling the flow rate of a gas fluid, and it is also useful in a system for controlling the flow rate of other fluids.

Claims (14)

1. A proportional control valve, comprising:

a housing including an upstream chamber and a downstream chamber through which a fluid passes, and a valve seat interposed between the upstream chamber and the downstream chamber;

a first diaphragm disposed in the housing such that pressure in the upstream chamber acts on the front surface and pressure in the downstream chamber acts on the back surface;

a second diaphragm disposed in the housing such that the pressure of the downstream chamber acts on the front surface and the atmospheric pressure acts on the back surface;

a valve body that moves in conjunction with the first diaphragm and the second diaphragm so as to be capable of being seated on and unseated from the valve seat; and

and a driving source for applying a driving force to the valve body.

2. The proportional control valve of claim 1, wherein the valve is configured to control the valve,

the pressure in the upstream chamber is set to P1, the pressure in the downstream chamber is set to P2, and the effective area of the first diaphragm is set to Ad ₁ Setting the effective area of the second diaphragm as Ad ₂ When the effective area of the valve body is Av and the driving force of the driving source is F, the balance of the forces in the moving direction of the valve body is satisfied

P2＝[F+(Ad ₁ -Av)·P1]/(Ad ₂ +Ad ₁ -Av)。

3. The proportional control valve of claim 2, wherein the valve is configured to control the valve,

effective area Ad of the first diaphragm ₁ And an effective area Ad of the second diaphragm ₂ Is formed to satisfy Ad ₂ /Ad ₁ ＞1。

4. The proportional control valve of claim 3, wherein the valve is,

the valve body includes:

a valve portion including a conical surface that tapers toward a front end of the downstream chamber so as to be able to contact the valve seat; and

and a rod portion connected to the first diaphragm and the second diaphragm.

5. The proportional control valve of any one of claims 1 to 4, wherein,

the housing includes a back pressure chamber on a back surface of the first diaphragm,

the valve body includes a communication passage that communicates the downstream chamber with the back pressure chamber.

6. The proportional control valve of any one of claims 1 to 4, wherein,

the drive source is a solenoid including a movable iron core engaged with the valve body and an exciting coil disposed around the movable iron core.

7. The proportional control valve of claim 6, wherein the valve is further configured to,

the valve body is disposed so as to move in the vertical direction and is seated on the valve seat by its own weight.

8. The proportional control valve of claim 7, wherein the valve is configured to control the valve,

comprises a force application member for applying force to the movable iron core towards the valve body.

9. The proportional control valve of claim 7, wherein the valve is configured to control the valve,

the upstream chamber is disposed above the valve seat, and the downstream chamber is disposed below the valve seat.

10. The proportional control valve of any one of claims 1 to 4, wherein,

the housing includes:

a housing body defining the upstream chamber, the downstream chamber, the valve seat, and a first opening for opening the upstream chamber and a second opening for opening the downstream chamber, respectively, on both outer sides in a moving direction of the valve body;

a first case cover that covers the first diaphragm disposed so as to close the first opening from outside; and

and a second case cover that covers the second diaphragm disposed so as to close the second opening from the outside.

11. The proportional control valve of claim 10, wherein the valve is configured to control the valve,

the valve body is configured to move in the vertical direction and is seated on the valve seat by self-weight,

the upstream chamber is disposed above the valve seat, and the downstream chamber is disposed below the valve seat.

12. The proportional control valve of claim 10, wherein the valve is configured to control the valve,

the housing body includes an inlet for fluid in communication with the upstream chamber and an outlet for fluid in communication with the downstream chamber,

the inlet and the outlet are disposed at the same height in the moving direction of the valve body.

13. The proportional control valve of claim 10, wherein the valve is configured to control the valve,

the first housing cover defines a back pressure chamber facing a back surface of the first diaphragm,

the valve body includes a communication passage that communicates the downstream chamber with the back pressure chamber.

14. The proportional control valve of claim 10, wherein the valve is configured to control the valve,

the second housing cover includes an open hole that opens a back surface of the second diaphragm to the atmosphere.