Proportional solenoid valve

Abstract

To reliably and easily secure a large flow rate control of fluid, and necessary durability.SOLUTION: When constituting a proportional solenoid valve comprising a stationary plunger 5 and an elastic restraining part 2 interposed between the stationary plunger and a movable plunger 6 and restraining the movable plunger 6 from moving a direction Fd orthogonal to a center axis direction Fc, an inner edge Si... is offset from an outer edge So... one (Fo) of the center axis directions Fc by predetermined width Ls, and an entirely ring-like plate spring member S... formed to elastically deform the inner edge Si... in the center axis direction Fc is provided to the outer edge So... At least two plate spring members S... are overlaid, so as to constitute the elastic restraining part 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a proportional solenoid valve suitable for use in a flow control valve or the like that continuously controls the flow rate of a fluid such as gas.

Background Art

[0002] Conventionally, a proportional solenoid valve that enables continuous control of the flow rate of a fluid by combining an electromagnetic drive unit and a valve mechanism unit is known, specifically, the proportional solenoid valve disclosed in Patent Document 1 proposed by the present applicant.

[0003] The proportional solenoid valve disclosed in the same Document 1 aims to enable easy adjustment to improve productivity and enable highly accurate adjustment by continuous position adjustment to achieve homogenization between products. Specifically, it includes an electromagnetic drive unit that displaces a movable plunger corresponding to the magnitude of an excitation voltage, a valve body provided at the front end of the movable plunger, and a valve seat that faces the valve body and has a flow path inside, and a valve mechanism unit having an elastic member that elastically supports the movable plunger at one end side. In addition, it includes a first adjustment mechanism unit that can adjust the position by displacing the position of the other end side of the elastic member in the valve displacement direction by operating a first operation unit arranged outside the yoke, and a second adjustment mechanism unit that can adjust the position by advancing and retracting the position of a fixed plunger relative to the movable plunger by operating a second operation unit arranged outside the yoke. In particular, it is configured to include a three-dimensional plate spring (elastic restriction unit) interposed between the fixed plunger and the movable plunger to restrict the movement of the movable plunger in a direction perpendicular to it.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the conventional proportional solenoid valve disclosed in Patent Document 1 described above had the following problems to be solved.

[0006] That is, as an elastic restricting portion that is interposed between the fixed plunger and the movable plunger and restricts the movement of the movable plunger in a direction perpendicular to it, a single three-dimensional plate spring was used. In this case, the larger the displacement amount of the movable plunger with respect to the fixed plunger, the greater the load stress (bending stress) on the plate spring.

[0007] For this reason, there are problems such as the life of the plate spring being shortened and it being easily damaged, resulting in a decrease in durability. Also, the displacement amount of the movable plunger cannot be set large, and the flow rate that can be controlled cannot be increased. Eventually, it is difficult to increase the flow rate of control in order to ensure durability. On the other hand, in order to increase the flow rate of control, durability is sacrificed. In other words, there is a trade-off relationship where improvement of durability performance and increase in the flow rate of control cannot be achieved simultaneously. There has been a demand for a proportional solenoid valve that can achieve both improvement of durability performance and increase in the flow rate of control.

[0008] An object of the present invention is to provide a proportional solenoid valve that solves the problems existing in such background art.

Means for Solving the Problems

[0009] In order to solve the above-described problems, the proportional solenoid valve 1 according to the present invention includes a fixed plunger 5 supported at its rear end side by a yoke 4y provided outside a solenoid 4, and a movable plunger 6 disposed so as to be displaceable forward and backward with respect to the fixed plunger 5. The proportional solenoid valve also includes an electromagnetic drive unit 3 that displaces the movable plunger 6 in accordance with the magnitude of a drive current Id supplied to the solenoid 4, a valve body 9 provided at the tip of the movable plunger 6, and a valve seat 10 facing the valve body 9, and a valve mechanism unit 7 having an elastic member 11 that elastically supports the movable plunger 6. When configuring a proportional solenoid valve including an elastic restricting unit 2 that is interposed between the fixed plunger 5 and the movable plunger 6 and restricts the movement of the movable plunger 6 in a direction Fd perpendicular to the central axis direction Fc, an inner edge portion Si... is offset by a predetermined width Ls in one direction (offset direction Fo) of the central axis direction Fc with respect to an outer edge portion So..., and an overall ring-shaped leaf spring member S... is formed such that the inner edge portion Si... is elastically displaceable in the central axis direction Fc with respect to the outer edge portion So.... The elastic restricting unit 2 is configured by stacking at least two or more of these leaf spring members S....

[0010] In this case, according to a preferred embodiment, the leaf spring member S can be integrally formed from a single stainless steel material Ms, and by forming a plurality of slits 15... between the outer edge portion So... and the inner edge portion Si..., one or more elastic pieces 16... of a predetermined length that can be elastically displaced in the central axis direction Fc with respect to the outer edge portion So... can be provided in the circumferential direction Ff. On the other hand, the elastic restriction portion 2 can be configured by overlapping the inner edge portions Si... in the offset direction Fo of the leaf spring member S... or the outer edge portions So... in the non-offset direction Fn, and one or more predetermined positions of the overlapping leaf spring members S... can be fixed by spot welding portions J.... Further, a shim ring Se having a flat surface fixed to the leaf spring member S located at at least one end in the central axis direction Fc can be provided in the elastic restriction portion 2. Furthermore, an opening portion 17... that allows the entry of a spot welding machine for performing spot welding on the leaf spring member S... can be provided in the elastic restriction portion 2. On the other hand, a restricting convex portion 18 with which the inner edge portion Si of the leaf spring member S engages can be formed on one or both of the opposing surfaces 5p, 6p of the fixed plunger 5 and / or the movable plunger 6 that face each other.

Advantages of the Invention

[0011] According to the proportional solenoid valve 1 according to the present invention having such a configuration, the following remarkable effects are achieved.

[0012] (1) The inner edge portion Si... is offset by a predetermined width Ls in one direction (offset direction Fo) of the central axis direction Fc with respect to the outer edge portion So..., and the entire ring-shaped leaf spring member S... formed such that the inner edge portion Si... can be elastically displaced in the central axis direction Fc with respect to the outer edge portion So... is provided. By stacking at least two or more of these leaf spring members S... to form the elastic restriction portion 2, even when the displacement amount of the movable plunger increases, the load stress (bending stress) on each leaf spring can be reduced. Therefore, both an increase in the large flow rate of flow control by setting a large displacement amount of the movable plunger and ensuring the necessary durability in the elastic restriction portion 2 can be reliably and easily realized.

[0013] (2) In a preferred embodiment, if the leaf spring member S is integrally formed from a single stainless steel material Ms, it can be manufactured by the same manufacturing method as the conventional method using punching and forming, etc. Therefore, a high-quality elastic regulation part 2 can be obtained easily and at low cost. Moreover, although the tensile strength and resistance of the spring material are low, by using a material excellent as a hydrogen embrittlement-resistant material, for example, SUS316L or the like, the service life can be extended without embrittlement.

[0014] (3) In a preferred embodiment, if the leaf spring member S is configured by forming a plurality of slits 15... between the outer edge part So... and the inner edge part Si..., and providing one or more elastic pieces 16... of a predetermined length in the circumferential direction Ff such that the inner edge part Si... is elastically displaceable in the central axis direction Fc with respect to the outer edge part So..., the elastic force can be set according to the shape, size, etc. of the elastic pieces 16..., and thus an optimal leaf spring member S (elastic regulation part 2) can be obtained.

[0015] (4) In a preferred embodiment, if the elastic regulation part 2 is configured by overlapping the inner edge parts Si... in the offset direction Fo of the leaf spring member S... or the outer edge parts So... in the non-offset direction Fn, a symmetric elastic regulation part 2 can be obtained. Also, when the displacement amount of the movable plunger is doubled, the displacement amount for each leaf spring can be reduced to 1 / 2.

[0016] (5) In a preferred embodiment, if the elastic regulation part 2 is fixed at one or more predetermined positions between the overlapping leaf spring members S... by spot welding parts J..., the rigidity can be increased, and thus a stable elastic regulation part 2 can be obtained.

[0017] (6) In a preferred embodiment, if a shim ring Se having a flat surface fixed to the leaf spring member S located at at least one end in the central axis direction Fc is provided on the elastic regulation part 2, in addition to the engaging part on the leaf spring member S side, an engaging part by the shim ring Se can be provided, so that it can be loaded stably and a smooth operation can be ensured.

[0018] (7) In a preferred embodiment, if the elastic regulation part 2 is provided with an opening part 17... that allows the entry of a spot welding machine for performing spot welding on the leaf spring member S..., the entry path of the spot welding machine can be secured, thereby avoiding the presence of obstructive parts and enabling reliable and smooth spot welding.

[0019] (8) In a preferred embodiment, if a regulation convex part 18 with which the inner edge part Si of the leaf spring member S engages is formed on one or both of the opposing surfaces 5p, 6p that face each other in the fixed plunger 5 and / or the movable plunger 6, the radial displacement between the fixed plunger 5 and the movable plunger 6 can be regulated, thereby preventing rattling, enabling stable mounting, and ensuring stable operation and performance.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0021] Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.

[0022] First, the configuration of the proportional solenoid valve 1 according to the present embodiment (basic embodiment) will be described with reference to FIGS. 1-6.

[0023] The exemplary proportional solenoid valve 1 is of the normally closed type. As shown in FIG. 3, as a basic configuration, it includes an electromagnetic drive part 3 located on the upper side (open side in the central axis direction Fc) and a valve mechanism part 7 located on the lower side (closed side in the central axis direction Fc). The electromagnetic drive part 3 includes a cylindrical solenoid 4 formed by winding a wire around a coil bobbin 31. Further, a yoke 4y is arranged outside the solenoid 4 to cover the solenoid 4. The yoke 4y is entirely formed of a magnetic material and is composed of a cylindrical yoke side surface part 4ym, a ring-shaped upper end surface part 4yu integrally formed at the upper end of the yoke side surface part 4ym, and a ring-shaped lower end surface part 4yd covering the lower end opening of the yoke side surface part 4ym. Inside the solenoid 4, that is, above (rear side) the internal space of the cylindrical body part 31c in the coil bobbin 31, a cylindrical fixed plunger 5 formed of a magnetic material is arranged, and below (front side) thereof, a cylindrical movable plunger 6 formed of a magnetic material is arranged. The fixed plunger 5 is supported by the upper end surface part 4yu of the yoke 4y via a first adjustment mechanism part C1 and a second adjustment mechanism part C2 described later, and the movable plunger 6 is arranged to be movable forward and backward in the central axis direction Fc.

[0024] Further, the outer diameters of the fixed plunger 5 and the movable plunger 6 are formed to be slightly smaller than the inner diameter of the cylindrical body portion 31c of the coil bobbin 31. A cylindrical adjustment cylinder 32 that constitutes the first adjustment mechanism portion C1 is accommodated in the gap between each of the plungers 5 and 6 and the cylindrical body portion 31c thus formed. The adjustment cylinder 32 is provided with a first operation portion 33 at the upper end portion of the outer peripheral surface 32w. Thereby, if the first operation portion 33 is rotationally operated, the adjustment cylinder 32 can be displaced in the vertical direction, and the first adjustment mechanism portion C1 is configured that can perform position adjustment by displacing the position of the other end side of the coil spring 11s by the front end (lower end) of the adjustment cylinder 32.

[0025] Furthermore, the fixed plunger 5 is provided with a plunger main body portion 5m and a bolt portion 5b integrally protruding upward from the upper end surface of the plunger main body portion 5m in the central axis direction Fc. The bolt portion 5b functions as a second operation portion 36. Thereby, if the second operation portion 36 is rotationally operated, the second adjustment mechanism portion C2 is configured that can perform position adjustment of the fixed plunger 5 by displacing the fixed plunger 5 in the vertical direction.

[0026] On the other hand, the valve mechanism portion 7 includes a block portion 41 formed of a non-magnetic material such as stainless steel. The upper end surface 41c of the block portion 41 serves as an attachment surface for attaching the lower end surface portion 4yd of the yoke 4y on the electromagnetic drive portion 3 side, and the lower end surface of the block portion 41 serves as an attachment surface to the flow path piping side. Inside the block portion 41, a valve chamber 42 formed to be hollow inside is provided, and a cylindrical valve seat 10 protruding upward is formed at the center of the bottom surface portion 41d forming the valve chamber 42. The inside of the valve seat 10 serves as a flow path. In the illustrated case, the lower end of this flow path is opened to the attachment surface as an inlet 43i, and one or two or more outlets 43e... are formed in the bottom surface portion 41d located around the valve seat 10.

[0027] On one hand, the movable plunger 6 includes a plunger main body portion 6m, a shaft-shaped spring support portion 6s integrally protruding downward in the central axis direction Fc from the lower end surface of the plunger main body portion 6m, and a valve body mounting plate portion 6c integrally formed at the lower end of the spring support portion 6s. The spring support portion 6s and the valve body mounting plate portion 6c are accommodated in the communication space 45. And a valve member 9g formed of rubber or the like is fixed to the lower surface of the valve body mounting plate portion 6c. The valve member 9g and the valve body mounting plate portion 6c constitute a valve body 9 provided at the front end 6f of the movable plunger 6. The lower surface of this valve body 9 faces the upper end opening of the valve seat 10 and functions as a valve body 9 for opening and closing the flow path R.

[0028] Also, the spring support portion 6s mounts the central opening of a ring-shaped spring seat 46, and a compressed elastic member 11, that is, a compressed coil spring 11c, is mounted between the spring seat 46 and the large-diameter portion at the lower end of the spring support portion 6s. The spring support portion 6s penetrates through the central opening of the spring seat 46 and the inside of the coil spring 11c. Due to the spring pressure of the coil spring 11c, the upper surface of the spring seat 46 is pressed against the lower end of the aforementioned adjustment cylinder 32. In this state, a gap with a predetermined interval is set between the upper surface of the spring seat 46 and the lower end surface of the plunger main body portion 6m. Also, the lower surface of the spring seat 46 is pressed against the upper end of the coil spring 11c. Thereby, when the solenoid 4 of the electromagnetic drive unit 3 is not excited, the lower surface of the valve body 9 is pressed against the upper end opening of the valve seat 10, and it becomes a normally closed state.

[0029] Furthermore, a plate spring 48 formed in a ring shape is attached between the outer peripheral surface at the lower end of the spring support portion 6s and the inner peripheral surface of the communication space 45. The plate spring 48 restricts the movement of the movable plunger 6 in a direction Fd perpendicular to the central axis direction Fc. In addition, in FIG. 3, 49a… and 49b indicate rubber sealing O-rings.

[0030] On the other hand, as shown in FIGS. 1 - 3, an elastic restricting portion 2 that constitutes the main part of the present invention for restricting the movement of the movable plunger 6 in a direction Fd perpendicular to the central axis direction Fc is interposed between the fixed plunger 5 and the movable plunger 6.

[0031] Next, the configuration and manufacturing method of this elastic restricting portion 2 will be specifically described with reference to FIGS. 1-6.

[0032] The elastic restricting portion 2 includes a leaf spring member S shown in FIGS. 4(b) and 6(b). This leaf spring member S offsets the inner edge portion Si by a predetermined width Ls in one direction (offset direction Fo) of the central axis direction Fc with respect to the outer edge portion So, and forms an overall shape that is elastically displaceable in the central axis direction Fc with respect to the outer edge portion So in a ring shape. Then, at least two or more of these leaf spring members S... are stacked to form the elastic restricting portion 2.

[0033] One leaf spring member S is integrally formed from one stainless steel material Ms. The exemplified stainless steel material Ms has a thickness of 0.1 [mm]. As the stainless steel material Ms, "SUS316L-H", which is a low-carbon stainless steel material excellent in corrosion resistance and workability of the welded portion, is desirable. By using such a stainless steel material Ms, it can be manufactured by the same manufacturing method as the conventional method using punching and forming, etc., so that a high-quality elastic restricting portion 2 can be obtained easily and at low cost. Although the tensile strength and resistance of the spring material are low, by using a material excellent as a hydrogen embrittlement-resistant material, for example, SUS316L or the like, the life can be extended without embrittlement.

[0034] FIG. 4(b) shows the planar shape of the leaf spring member S. The planar shape of the leaf spring member S has an inner edge portion Si that becomes the inner ring diameter and an outer edge portion So that becomes the outer ring diameter as a whole. Further, between the outer edge portion So and the inner edge portion Si, a plurality (exemplified as three) of slits 15... are formed, so that one or two or more (exemplified as three) elastic pieces 16... having a predetermined length that are elastically displaceable in the central axis direction Fc with respect to the outer edge portion So are provided in the circumferential direction Ff. Thereby, since the elastic force can be set according to the shape, size, etc. of the elastic pieces 16..., an optimal leaf spring member S (elastic restricting portion 2) can be obtained. As shown in FIG. 4(b), positioning hole portions 15s... having a diameter larger than the slit width of each slit 15... are formed in a continuous shape at the end portions on the inner edge portion Si side of each slit 15....

[0035] Further, as shown in FIG. 6(b), the leaf spring member S offsets the inner edge portion Si by a predetermined width Ls in one direction (offset direction Fo) of the central axis direction Fc with respect to the outer edge portion So. In the illustrated case, the predetermined width Ls is 0.5 [mm]. Thereby, the leaf spring member S can be elastically displaced in the central axis direction Fc with respect to the outer edge portion So with the inner edge portion Si. As described above, one leaf spring member S can be obtained.

[0036] On the other hand, when configuring the elastic regulation portion 2, two leaf spring members S, S are prepared and are configured by overlapping the inner edge portions Si... with each other in the offset direction Fo, or the outer edge portions So... with each other in the non-offset direction Fn. The illustration shows a case where the outer edge portions So... with each other in the non-offset direction Fn are overlapped as shown in FIGS. 5 and 6. With this configuration, a symmetric elastic regulation portion 2 can be obtained, and when the displacement amount of the movable plunger is doubled, the displacement amount with respect to the leaf spring per sheet can be made 1 / 2.

[0037] In this case, if the pair of leaf spring members S, S shown in FIGS. 5 and 6 are each inverted up and down, a configuration in which the inner edge portions Si... with each other in the offset direction Fo are overlapped can be obtained. Further, for the two leaf spring members S, S, the same leaf spring members S, S may be prepared and one of them may be used after being inverted up and down, or one of the two leaf spring members S, S may be offset upward and the other may be offset downward and formed as separate parts with different shapes. The elastic regulation portion 2 shown in FIGS. 5 and 6 shows a case where the two leaf spring members S, S are formed as separate parts with different shapes as described above. Therefore, the plane of one (upper side) leaf spring member S shown in FIG. 5 has a shape offset toward the front of the paper as shown in FIG. 4(b), and the plane of the other (lower side) leaf spring member S shown in FIG. 5 has a shape offset toward the back side of the paper as shown in FIG. 4(c).

[0038] Furthermore, as shown in FIGS. 4-6, the elastic regulation unit 2 shown in the embodiment includes a shim ring Se fixed to a leaf spring member S located at one end in the central axis direction Fc. The shim ring Se has the same thickness and the same ring inner diameter as the leaf spring member S, and the ring outer diameter is formed to be slightly larger than the ring outer diameter of the leaf spring member S as shown in FIG. 5. Sei indicates the inner edge of the shim ring Se, and Seo indicates the outer edge of the shim ring Se.

[0039] The shim ring Se is entirely a flat surface, and positioning holes 51s corresponding to the positioning holes 15s provided in the leaf spring member S are formed at the same positions in the plane. Further, an opening 17 is provided to allow the entry of a spot welding machine for performing spot welding on the leaf spring member S, which will be described later. Thereby, since the entry path of the spot welding machine can be secured, the presence of obstructive parts can be avoided, and spot welding can be performed reliably and smoothly. By providing such a shim ring Se, in addition to the engaging portion on the leaf spring member S side, an engaging portion by the shim ring Se can be provided, so that there are advantages that it can be loaded stably and a smooth operation can be ensured.

[0040] As described above, the elastic regulation unit 2 shown in the embodiment is composed of three parts: two leaf spring members S, S and one shim ring Se.

[0041] Next, a manufacturing method of the elastic regulation unit 2 according to such an embodiment will be described with reference to FIG. 7.

[0042] FIG. 7(a) shows the first step M1. In the first step M1, the shim ring Se is set on three positioning pins 61 provided at predetermined positions in an assembly jig (not shown). Thereby, each positioning pin 61 is inserted into the positioning hole 51s of the shim ring Se to position the shim ring Se. After that, one leaf spring member S is set on the upper surface of the shim ring Se. Thereby, each positioning pin 61 is inserted into each positioning hole 15s of one leaf spring member S to position one leaf spring member S with respect to the shim ring Se.

[0043] Also, as shown in FIG. 5, since the inner edge Sei of the shim ring Se and the inner edge Si of the leaf spring member S overlap, one or two or more (exemplified as three locations) of the predetermined positions where the shim ring Se and the leaf spring member S overlap are fixed by spot welding using a predetermined spot welding machine to obtain an intermediate assembly Am. FIG. 7(a) shows this state. Note that the symbol J... indicates the spot welded portions.

[0044] Next, the second step M2 shown in FIG. 7(b) is performed. In the second step M2, as shown in FIG. 7(b), the other leaf spring member S is set on the upper surface of one of the leaf spring members S in the intermediate assembly Am. Thereby, each positioning pin 61... is inserted into each positioning hole portion 15s... of the other leaf spring member S to position the other leaf spring member S with respect to the intermediate assembly Am.

[0045] Next, the second step M3 shown in FIG. 7(c) is performed. In the second step M3, first, the whole including the intermediate assembly Am and the other leaf spring member S is inverted up and down. This state becomes FIG. 7(c). In this state, since the shim ring Se is on the topmost surface, through the opening 17... of the shim ring Se, three predetermined locations on the one leaf spring member S and the other leaf spring member S are fixed by spot welding using a spot welding machine. The symbol J... in FIG. 7(c) indicates the spot welded portions.

[0046] Through the above steps M1 - M3, the elastic regulation portion 2 shown in FIG. 5 can be obtained. In this way, if the elastic regulation portion 2 is fixed by the spot welded portions J... at one or two or more predetermined positions between the overlapping leaf spring members S... (including the shim ring Se), the rigidity can be increased, and thus a stable elastic regulation portion 2 can be obtained.

[0047] Then, when the fixed plunger 5 and the movable plunger 6 are assembled, this elastic regulation part 2 is interposed between the fixed plunger 5 and the movable plunger 6. In this case, as shown in FIG. 1, a regulation convex part 18 is formed on a part of the center side of the facing surface 6p of the movable plunger 6 facing the fixed plunger 5. The regulation convex part 18 has a trapezoidal cross section. When the elastic regulation part 2 is mounted, the inner edge part Si of the other leaf spring member S located on the lower side in the elastic regulation part 2 engages with the lower end of the regulation convex part 18 without a gap, and the displacement of the elastic regulation part 2 in the radial direction is regulated. In addition, a concave part 55 into which the regulation convex part 18 enters and fits is formed on the facing surface 5p of the fixed plunger 5.

[0048] Also, as shown in FIGS. 1 and 2, for the shim ring Se in the elastic regulation part 2, the outer edge part So engages with the inner peripheral surface of the adjustment cylinder 32, and the displacement of the shim ring Se, that is, the elastic regulation part 2 in the radial direction is regulated. In the embodiment, the case where the regulation convex part 18 is formed on the facing surface 6p of the movable plunger 6 is shown. However, when the shim ring Se is not used as in the elastic regulation part 2 shown in the modified embodiment described later, the regulation convex part 18 may be provided on the facing surface 5p of the fixed plunger 5.

[0049] In this way, if the regulation convex part 18 with which the inner edge part Si of the leaf spring member S engages is formed on one or both of the opposing facing surfaces 5p and 6p of the fixed plunger 5 and / or the movable plunger 6, the displacement in the radial direction between the fixed plunger 5 and the movable plunger 6 can be regulated. Therefore, rattling can be prevented, and it can be stably mounted, and stable operation and performance can be ensured.

[0050] Next, the basic operation of the proportional solenoid valve 1 according to this embodiment configured as described above will be mainly described with reference to FIG. 3.

[0051] This proportional solenoid valve 1 can be used by connecting it to a gas pipe. The solenoid 4 of the proportional solenoid valve 1 is connected to a power supply unit, and this power supply unit is connected to a control unit. Therefore, when a control signal is applied from the control unit to the power supply unit, a drive current Id having a magnitude corresponding to the control signal is supplied to the solenoid 4.

[0052] Now, if the drive current Id applied to the solenoid 4 from the power supply unit is zero (OFF state), the valve opening degree of the proportional solenoid valve 1 also becomes 0. Therefore, the proportional solenoid valve 1 is in a normally closed state. That is, since the solenoid 4 of the electromagnetic drive unit 3 is not excited, the valve body 9 is pressed against the upper end opening of the valve seat 10 by the spring pressure of the coil spring 11c. As a result, the connected gas pipe is blocked and becomes a fully closed state.

[0053] On the other hand, when the output of the power supply unit is turned on and the drive current Id is changed, the valve opening degree (fluid flow rate) changes corresponding to the magnitude of the drive current Id, as shown by the characteristic curve Qia in Fig. 8. That is, if the magnitude of the drive current Id is gradually increased from zero, the magnetic force generated by the excitation of the solenoid 4 also gradually increases. The movable plunger 6 is attracted toward the fixed plunger 5 side and displaced upward, and stops at the position where the movable plunger 6 abuts against the fixed plunger 5. At this position, the valve opening degree is maximum, that is, it becomes a fully open state, and the fluid flow rate becomes 100 [%] of the maximum flow rate.

[0054] Figs. 8 and 9 respectively show characteristic diagrams of the drive current versus fluid flow rate of the proportional solenoid valve 1 according to the present embodiment.

[0055] Fig. 8 compares the characteristics of the proportional solenoid valve 1 according to the present embodiment with those of the proportional solenoid valve according to the conventional example. Qia and Qib are the cases when the elastic restriction unit 2 according to the present embodiment is used. Qia shows the case from the fully closed state to the fully open state, and Qib shows the case from the fully open state to the fully closed state. Also, Qra and Qrb are the proportional solenoid valves according to the conventional example, that is, the cases where the elastic restriction unit 2 is configured using only a single leaf spring member. Qra shows the characteristic curve in the case from the fully closed state to the fully open state, and Qrb shows the characteristic curve in the case from the fully open state to the fully closed state. As is clear from Fig. 8, it can be confirmed that even in the proportional solenoid valve 1 according to the present embodiment incorporating the elastic restriction unit 2, the characteristics of the drive current versus fluid flow rate show a good proportional relationship as in the conventional example.

[0056] FIG. 9 shows the durability test results of the proportional solenoid valve 1 according to the present embodiment. Qxs and Qys are the characteristics at the initial stage, Qxt and Qyt are after 1 million opening / closing operations, and Qxu and Qyu are after 2.5 million opening / closing operations, respectively. As is clear from FIG. 9, it can be confirmed that the proportional solenoid valve 1 according to the present embodiment incorporating the elastic restricting portion 2 can obtain proportional characteristics equivalent to those at the initial stage even after the durability test, and no problems such as breakage occurred in the elastic restricting portion 2.

[0057] Next, the elastic restricting portion 2 of the proportional solenoid valve 1 according to the modified embodiment of the present invention will be described with reference to FIGS. 10 - 13.

[0058] As shown in FIGS. 10 and 11, the elastic restricting portion 2 according to the modified embodiment shown uses only two leaf spring members S, S and does not use a shim ring Se. Therefore, as shown in FIG. 11, restricting convex portions 18... with which the inner edge portions Si... of the respective leaf spring members S, S engage are formed on both of the opposing surfaces 5p, 6p of the fixed plunger 5 and the movable plunger 6 that face each other. That is, the restricting convex portion 18 is formed on the opposing surface 6p of the movable plunger 6 with which the other leaf spring member S located on the lower side engages, and a similar restricting convex portion 18 is also formed on the opposing surface 5p of the fixed plunger 5 with which the one leaf spring member S located on the upper side engages. Since each restricting convex portion 18... only needs to engage with the inner edge portions Si... of the respective leaf spring members S, S, they are formed as disk-shaped restricting convex portions 18... having a low height.

[0059] Further, as shown in FIGS. 12 and 13, the elastic regulation unit 2 according to another modified embodiment is formed by stacking two sets of the elastic regulation units 2 according to the modified embodiments shown in FIGS. 10 and 11 vertically, so to speak, using four leaf spring members S, S... In this case, the regulation convex portions 18... provided on the opposing surfaces 5p, 6p provided on the fixed plunger 5 and the movable plunger 6 can be formed in the same manner as in the modified embodiments shown in FIGS. 10 and 11. In this case, since the elastic regulation units 2... are also fixed to each other, the opening portions 17... that allow the entry of a spot welding machine for performing spot welding on the leaf spring members S... can be provided by selecting a predetermined position so as to ensure the entry path of the spot welding machine.

[0060] As described above, the proportional solenoid valve 1 according to this embodiment including the modified embodiments, as a basic configuration, offsets the inner edge portion Si... by a predetermined width Ls in one direction (offset direction Fo) of the central axis direction Fc with respect to the outer edge portion So..., and forms the inner edge portion Si... so as to be elastically displaceable in the central axis direction Fc with respect to the outer edge portion So..., and the whole is provided with a ring-shaped leaf spring member S... By stacking at least two or more of these leaf spring members S... to form the elastic regulation unit 2, even if the displacement amount of the movable plunger increases, the load stress (bending stress) on each leaf spring can be reduced. Therefore, both the increase in the large flow rate of the flow control by setting a large displacement amount of the movable plunger and the ensuring of the necessary durability in the elastic regulation unit 2 can be reliably and easily realized.

[0061] As described above, the preferred embodiments including the modified embodiments have been described in detail. However, the present invention is not limited to such embodiments, and can be arbitrarily changed, added, or deleted within the scope not departing from the gist of the present invention in terms of the detailed configuration, shape, material, quantity, numerical value, etc.

[0062] For example, although it is desirable that the leaf spring member S be integrally formed from a single stainless steel material Ms, the selection of the material is not limited to the stainless steel material Ms, and the use of other materials having similar functions is not excluded. Further, by forming a plurality of slits 15... between the outer edge portion So... and the inner edge portion Si..., a case is illustrated in which three elastic pieces 16... of a predetermined length in which the inner edge portion Si... is elastically displaceable in the central axis direction Fc with respect to the outer edge portion So... are provided in the circumferential direction Ff. However, the number to be provided can be selected as any number of one or two or more, and the shape of the elastic pieces 16... can also be arbitrarily selected. Furthermore, although the proportional solenoid valve 1 of the normally closed type is illustrated, it is similarly applicable to the normally open type (fully open when non-energized). In addition, although gas is illustrated as the fluid, various fluids such as air and liquid can be applied. Also, although the method of fixing by the spot weld portion J... is desirable, as other fixing methods, various fixing methods such as arc welding method, gas welding method, resistance welding method, laser welding method, flash butt welding method, friction pressure welding method, brazing method, etc. can be utilized.

Industrial Applicability

[0063] The proportional solenoid valve according to the present invention can be used as various solenoid valves such as a flow control valve that continuously controls the flow rate of a fluid such as gas.

Explanation of Reference Numerals

[0064] 1: Proportional solenoid valve, 2: Elastic restricting portion, 3: Electromagnetic driving portion, 4: Solenoid, 4y: Yoke, 5: Fixed plunger, 5p: Opposing surface, 6: Movable plunger, 6p: Opposing surface, 7: Valve mechanism portion, 9: Valve body, 10: Valve seat, 11: Elastic member, 15...: Slit, 16...: Elastic piece, 17...: Opening portion, 18: Restricting convex portion, Id: Driving current, Fc: Central axis direction, Fd: Direction perpendicular to the central axis direction, Fo: Offset direction, Fn: Non-offset direction, Ff: Circumferential direction, S...: Leaf spring member, So...: Outer edge portion, Si...: Inner edge portion, Se: Shim ring, Ls: Predetermined width, Ms: Stainless steel material, J...: Spot weld portion

Claims

1. Inside a yoke provided outside a solenoid, there are a fixed plunger whose rear end side is supported by this yoke, and a movable plunger arranged so as to be displaceable forward and backward with respect to this fixed plunger. There is also an electromagnetic drive unit that displaces the movable plunger corresponding to the magnitude of the drive current supplied to the solenoid, a valve mechanism unit having a valve body provided at the tip of the movable plunger and a valve seat facing this valve body, and an elastic member that elastically supports the movable plunger. In a proportional solenoid valve comprising an elastic restricting portion interposed between the fixed plunger and the movable plunger to restrict movement of the movable plunger in a direction perpendicular to it, the inner edge portion is offset by a predetermined width in one direction of the central axis with respect to the outer edge portion, and an overall ring-shaped leaf spring member is formed such that the inner edge portion is elastically displaceable in the central axis direction with respect to the outer edge portion. The elastic restricting portion is configured by stacking at least two or more of these leaf spring members. The proportional solenoid valve is characterized by this.

2. The proportional solenoid valve according to claim 1, wherein the leaf spring member is integrally formed from a single stainless steel material.

3. The proportional solenoid valve according to claim 2, wherein the leaf spring member is provided with one or two or more elastic pieces of a predetermined length in the circumferential direction, in which the inner edge portion is elastically displaceable in the central axis direction with respect to the outer edge portion, by forming a plurality of slits between the outer edge portion and the inner edge portion.

4. The proportional solenoid valve according to claim 1, wherein the elastic restricting portion is configured by overlapping the inner edge portions in the offset direction of the leaf spring member, or the outer edge portions in the non-offset direction.

5. The proportional solenoid valve according to claim 4, wherein one or two or more predetermined positions between the overlapping leaf spring members of the elastic restricting portion are fixed by spot welding portions.

6. The proportional solenoid valve according to claim 1, wherein the elastic restricting portion includes a shim ring having a flat surface, which is fixed to the leaf spring member located at at least one end in the central axis direction.

7. The proportional solenoid valve according to claim 1 or 6, wherein the elastic restricting portion has an opening portion that allows entry of a spot welding machine for performing spot welding on the leaf spring member.

8. The proportional solenoid valve according to claim 1, wherein a regulating convex portion with which the inner edge portion of the leaf spring member engages is formed on one or both of the opposing surfaces facing each other in the fixed plunger and / or the movable plunger.

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