Linear motor valve

Abstract

It controls relatively large flow rates while maintaining high control accuracy in the low flow rate range, ensuring stable control accuracy from small to large flow rates. It prevents adverse effects from particle generation, ensuring high reliability and long lifespan. [Solution] The device includes a ring-shaped leaf spring member 5 whose inner circumference 5c is relatively displaceable in the axial direction Fs. The outer circumference 5f of the leaf spring member 5 is fixed to the housing 2h by arranging the leaf spring member 5 coaxially with respect to the solenoid part 2, and the inner circumference 5c of the leaf spring member 5 is fixed to the movable part 3.

Description

Technical Field

[0001] The present invention relates to a linear motor valve that is opened and closed by a movable part that moves forward and backward in the axial direction by energization control of a solenoid part.

Background Art

[0002] Conventionally, as a linear motor valve including a cylindrical solenoid part fixed to a housing, a plunger axially disposed inside the solenoid part, and a magnet fixed to the outer periphery of the plunger, and a movable part that moves forward and backward in the axial direction by energization control of the solenoid part, and a valve mechanism part having a valve body part fixed to one end side of the movable part, a fluid control valve described in Patent Document 1 is known.

[0003] The fluid control valve described in the same Document 1 is intended to provide a fluid control valve that maintains stable control or operation even when one or both of the primary pressure and the secondary pressure fluctuate. A first diaphragm and a second diaphragm are disposed between the valve body and the body, a diaphragm chamber is formed between the first diaphragm and the second diaphragm, the first diaphragm partitions the valve chamber and the diaphragm chamber, the second diaphragm partitions the diaphragm chamber and the back pressure chamber, the diaphragm chamber communicates with the output port, the valve chamber and the back pressure chamber communicate with the input port, and the difference between the effective pressure receiving areas of the first diaphragm and the second diaphragm is made equal to the passage area at the valve seat. As one form of this fluid control valve, a linear motor valve is described. In this linear motor valve, the mover of the linear motor has a center yoke and a pair of permanent magnets fixed to a shaft. The pair of permanent magnets magnetized in the axial direction (vertical direction) are arranged with the same poles facing each other with the center yoke interposed therebetween. When a drive current flows through the electromagnetic coil, an upward or downward thrust is generated in the permanent magnet and the center yoke according to the direction of the drive current, and the magnitude of this thrust is made proportional to the magnitude of the drive current.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-159723 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the conventional linear motor valves mentioned above had the following problems.

[0006] Firstly, while the movable element can be displaced axially and relatively large flow rates can be controlled, the control accuracy tends to become unstable. In particular, high control accuracy cannot be achieved in the low flow rate range, so even if the control range can be set wide from small to large flow rates, stable and high-precision control accuracy cannot be ensured across the entire control range.

[0007] Secondly, because there are sliding parts between the movable element that displaces in the axial direction and the part that supports it, particles are likely to be generated. In particular, there is a risk of generating fine particles of several hundred to several tens of nanometers, and these generated particles may remain inside the fluid control valve as foreign matter. Ultimately, this can cause problems such as failure of the fluid control valve and may also adversely affect the controlled substance such as the fluid, thus making it impossible to ensure reliability.

[0008] The present invention aims to provide a linear motor valve that solves the problems present in the background technology described above. [Means for solving the problem]

[0009] To solve the above-mentioned problems, the present invention provides a linear motor valve 1 comprising a cylindrical solenoid section 2 fixed to a housing 2h, a movable section 3 having a plunger 3p arranged axially Fs inside the solenoid section 2 and a magnet 3m fixed around the outer circumference of the plunger 3p, and a valve mechanism section 4 having a valve body 4v fixed to one end 3s of the movable section 3, wherein at least the inner circumference 5c of the leaf spring member 5 is displaceable relative to the axial direction Fs, and the outer circumference 5f of the leaf spring member 5 is fixed to the housing 2h by arranging the leaf spring member 5 coaxially with respect to the solenoid section 2, and the inner circumference 5c of the leaf spring member 5 is fixed to the movable section 3.

[0010] In this case, according to a preferred embodiment of the invention, the leaf spring member 5 can be integrally formed from a single stainless steel material Ms, and by forming a plurality of slits 11... between the outer circumference 5f and the inner circumference 5c of the leaf spring member 5, the inner circumference 5c can be provided with zigzag elastic strips 12... having one or more predetermined lengths that are elastically displaceable in the axial direction Fs relative to the outer circumference 5f. The inner circumference 5c of this leaf spring member 5 can be fixed to one end 3s of the axial direction Fs in the movable part 3, and the outer circumference 5f can be fixed to one end 2s of the axial direction Fs in the solenoid part 2. More preferably, at least two leaf spring members 5… can be provided, with the inner circumference 5c of one leaf spring member 5 fixed to one end 3s of the axial direction Fs of the movable part 3, and the outer circumference 5f fixed to one end 2s of the axial direction Fs of the solenoid part 2, while the inner circumference 5c of the other leaf spring member 5 is fixed to the other end 3t of the axial direction Fs of the movable part 3, and the outer circumference 5f is fixed to the other end 2t of the axial direction Fs of the solenoid part 2. Furthermore, the leaf spring member 5 can be configured to be changed to a normally closed type or a normally open type by changing its shape or arrangement position. The magnet 3m can be configured by arranging one or more magnets in the axial direction Fs of the plunger 3p. [Effects of the Invention]

[0011] The linear motor valve 1 according to the present invention, having such a configuration, provides the following remarkable effects.

[0012] (1) The device is equipped with a ring-shaped leaf spring member 5 whose inner circumference 5c is at least displaceable relative to the axial direction Fs. By arranging this leaf spring member 5 coaxially with respect to the solenoid section 2, the outer circumference 5f of the leaf spring member 5 is fixed to the housing 2h, and the inner circumference 5c of the leaf spring member 5 is fixed to the movable section 3. This allows for control of relatively large flow rates and improves control accuracy in the low flow rate range. This ensures stable control accuracy from small to large flow rates.

[0013] (2) Since there is no sliding part between the movable part 3 which is displaced in the axial direction and the housing 2h that supports the movable part 3, no particles are generated. As a result, there is no risk of adverse effects from particles, that is, the risk of foreign matter remaining inside the fluid control valve and causing problems such as failure of the fluid control valve, and there is no risk of adverse effects on the controlled object such as the fluid, thus ensuring high reliability and a long lifespan.

[0014] (3) In a preferred embodiment, if the leaf spring member 5 is integrally formed from a single piece of stainless steel material Ms, it can be manufactured using the same manufacturing method as conventional methods, such as punching, and thus a high-quality elastic restricting part 2 can be easily and inexpensively obtained.

[0015] (4) In a preferred embodiment, when forming the leaf spring member 5, if a plurality of slits 11... are formed between the outer circumference 5f and the inner circumference 5c, and the inner circumference 5c is provided with zigzag elastic strips 12... having one or more predetermined lengths that can be elastically displaced in the axial direction Fs relative to the outer circumference 5f, the elastic force can be set by the shape and size of the elastic strips 12..., thereby obtaining an optimal leaf spring member 5. Furthermore, it becomes possible to use multiple leaf spring members 5... stacked on top of each other. As a result, even if the amount of displacement of the movable part 3 increases, the load stress (bending stress) on each leaf spring member 5 can be reduced, so that both high flow rate control and the necessary durability of the leaf spring member 5 can be reliably and easily achieved.

[0016] (5) In a preferred embodiment, when providing the leaf spring member 5, if the inner circumference 5c is fixed to one end 3s of the axial direction Fs in the movable part 3 and the outer circumference 5f is fixed to one end 2s of the axial direction Fs in the solenoid part 2, the leaf spring member 5 can be positioned closest to the valve body 4 fixed to one end 3s of the movable part 3. This ensures stable operation even when combined with other support members (such as bearing members) that support the other end of the movable part 3, ensures the required control accuracy, and moreover, sufficiently prevents the generation of particles.

[0017] (6) In a preferred embodiment, when providing the leaf spring members 5..., at least two are prepared, and the inner circumference 5c of one leaf spring member 5 is fixed to one end 3s of the axial direction Fs of the movable part 3, and the outer circumference 5f is fixed to one end 2s of the axial direction Fs of the solenoid part 2, while the inner circumference 5c of the other leaf spring member 5 is fixed to the other end 3t of the axial direction Fs of the movable part 3, and the outer circumference 5f is fixed to the other end 2t of the axial direction Fs of the solenoid part 2. In this way, both ends of the movable part 3 in the axial direction Fs can be supported by the same leaf spring members 5..., so that stable support can be achieved, control accuracy can be improved, and optimal performance can be obtained from the viewpoint of preventing particle generation.

[0018] (7) In a preferred embodiment, if it is configured to be changeable to a normal close type or a normal open type by changing the form or arrangement position of the leaf spring member 5, it can be easily converted to both the normal close type and the normal open type only by changing the form or arrangement position of the leaf spring member 5.

[0019] (8) In a preferred embodiment, when configuring the magnet 3m, if it is arranged one or more in the axial direction Fs of the plunger 3p, the quantity, direction, positional relationship, etc. of the magnet 3m can be selected, and the overall form of the magnet 3m can be designed. Therefore, the degree of design freedom can be increased, and the optimization of the target linear motor valve 1 can be achieved.

Brief Description of the Drawings

[0020] [Figure 1] Vertical side view of the linear motor valve according to a preferred embodiment of the present invention, [Figure 2] Cross-sectional view taken along line A-A in FIG. 1 of the same linear motor valve, [Figure 3] Plan view of the leaf spring member used in the same linear motor valve, [Figure 4] End view taken along line B-B in FIG. 3 of the same leaf spring member, [Figure 5] Exploded view of the same linear motor valve, [Figure 6] Actuating diagram showing the state of the same linear motor valve when used in normal close, [Figure 7] Actuating diagram showing the state of the same linear motor valve when used in normal open, [Figure 8] Vertical side view showing a modification example of the same linear motor valve,

Mode for Carrying Out the Invention

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

[0022] First, the configuration of the linear motor valve 1 according to the present embodiment will be described with reference to FIGS. 1-5.

[0023] First, the basic configuration of the linear motor valve 1 will be explained with reference to Figures 1 and 2. This linear motor valve 1 is composed of a solenoid section 2, a movable section 3, and a valve body mechanism section 4.

[0024] The solenoid section 2 is cylindrical in shape, and a coil 22 is formed by winding a magnet wire around the outer surface of a cylindrical coil bobbin 21, specifically in the intermediate axial portion (approximately 1 / 3 of the axial direction). This coil 22 is fixed inside the cylindrical housing 2h shown in Figure 2, which constitutes the outer casing of the linear motor valve 1. A magnetic material 22u, such as iron, is housed in the upper space of the coil 22 wound around the coil bobbin 21, and a magnetic material 22d, such as iron, is housed in the lower space of the coil 22.

[0025] The housing 2h is composed of a cylindrical housing body 15 and a housing end face 16 that covers the upper end of the housing body 15, and a housing base 2hd is provided at the lower end of the housing body 15. This housing base 2hd includes an attachment portion 17 for a gas pipe P, etc., which will be described later, and a valve chamber block portion 18 fixed to the upper part of the attachment portion 17, and the lower end of the housing body 15 is fixed to the upper end of the valve chamber block portion 18. Therefore, the housing 2h as a whole is composed of the housing body 15, the housing end face portion 16, the attachment portion 17, and the valve chamber block portion 18.

[0026] The movable part 3 has a plunger 3p positioned inside the solenoid part 2 so as to be displaceable in the axial direction Fs, and a magnet 3m fixed around the outer circumference of the plunger 3p, and moves forward and backward in the axial direction Fs in response to the energization control of the solenoid part 2. The plunger 3p is formed in the shape of a round bar, and an upper bolt part 3pu and a lower bolt part 3pd are formed at the upper and lower ends, respectively. Also, as shown in Figure 1, a cylindrical upper magnet 3mu and a lower magnet 3md are fixed at the upper and lower positions of the plunger 3p.

[0027] Reference numerals 23, 24, and 25 indicate separator members made of magnetic material, positioned at the upper end of the upper magnet 3mu, between the upper magnet 3mu and the lower magnet 3md, and at the lower end of the lower magnet 3md, respectively. The upper magnet 3mu is magnetized with its upper side as the south pole and its lower side as the north pole, while the lower magnet 3md is magnetized with its upper side as the north pole and its lower side as the south pole. The upper magnet 3mu and the lower magnet 3md together constitute the magnet 3m.

[0028] Thus, when configuring the magnet 3m, by arranging one or more magnets in the axial direction Fs of the plunger 3p, the quantity, direction, positional relationship, etc. of the magnet 3m can be selected, and the overall form of the magnet 3m can be designed, thereby increasing the degree of design freedom and optimizing the linear motor valve 1 to the desired specifications.

[0029] The valve mechanism 4 includes a valve body 4v fixed to one end (lower end) 3s of the movable part 3. The example valve body 4v consists of a mounting portion 26 formed in a conical shape from a non-magnetic material and a sheet-like elastic member 27 made of rubber or the like fixed to the flat surface at the lower end of the mounting portion 26. A nut portion 35 is integrally formed at the upper end of the mounting portion 26, and the nut portion 35 can be connected to the lower end of the plunger 3p. Furthermore, a valve seat portion 4s is provided below the valve body portion 4v, i.e., opposite the elastic member 27. The valve mechanism 4 is composed of this valve seat portion 4s and the valve body portion 4v.

[0030] As a result, when the valve body 4v is displaced downward and the elastic member 27 is pressed against the valve seat 4s, the valve mechanism 4 is in a closed state (OFF). On the other hand, when the valve body 4v is displaced upward and the elastic member 27 is separated from the valve seat 4s, the valve mechanism 4 is in an open state (ON).

[0031] Next, the configuration of the main parts of the linear motor valve 1 according to this embodiment will be described with reference to Figures 1-5.

[0032] The linear motor valve 1 according to this embodiment includes a ring-shaped leaf spring member 5 whose inner circumference 5c is at least displaceable relative to the axial direction Fs.

[0033] Specifically, as shown in Figures 1 and 2, the movable part 3 is supported by a pair of upper and lower leaf spring members 5. As shown in Figures 3 and 4, the leaf spring members 5 can be integrally formed from a single piece of stainless steel material Ms. For example, "SUS316L-H," a low-carbon stainless steel material with excellent corrosion resistance and workability, can be used to integrally form a plate with a thickness of approximately 0.1-0.5 mm. In this way, by integrally forming the leaf spring members 5 from a single piece of stainless steel material Ms, they can be manufactured using the same methods as conventional methods, such as punching, making it possible to easily and inexpensively obtain a high-quality elastic restricting part 2.

[0034] Furthermore, as shown in Figure 3, the planar shape of the leaf spring member 5 is ring-shaped overall, comprising a circular inner circumference 5c and a circular outer circumference 5f. By forming multiple (three in this example) slits 11... between the outer circumference 5f and the inner circumference 5c, as shown in Figure 4, the inner circumference 5c is formed to have one or more (two in this example) zigzag elastic strips 12... of a predetermined length that can be elastically displaced in the axial direction Fs relative to the outer circumference 5f.

[0035] By forming it in this way, the elastic force can be set by the shape and size of the elastic strip 12, etc., so an optimal leaf spring member 5 can be obtained. Furthermore, by using multiple leaf spring members 5 stacked on top of each other, even if the displacement of the movable part 3 becomes large, the load stress (bending stress) on each leaf spring member 5 can be reduced, so both high flow rate control and the necessary durability of the leaf spring member 5 can be reliably and easily achieved. In this way, a single leaf spring member 5 can be obtained.

[0036] Next, the assembly method of the leaf spring members 5, 5 that constitute the main part of this embodiment will be described with reference to Figures 1 and 5.

[0037] First, as shown in Figure 1, a mounting circular hole 31u having an inner diameter equal to the outer diameter of the leaf spring member 5 is formed on the upper end surface of the housing body portion 15 that constitutes the housing 2h, and a mounting circular hole 31u having an inner diameter equal to the outer diameter of the leaf spring member 5 is formed in the intermediate portion of the inner circumferential surface of the valve chamber block portion 18 that constitutes the housing 2h.

[0038] Next, two leaf spring members 5 are prepared, and one (lower) leaf spring member 5 is placed in the mounting circular hole 31d formed in the valve chamber block 18, and then fixed with a fixing ring 33. This fixing ring 33 can be fixed to the mounting circular hole 31d by screwing it in. Then, the lower bolt portion 3pd of the plunger 3p in the movable part 3 is inserted into a circular hole formed on the inner circumference 5c of one of the leaf spring members 5, and then the nut portion 35 provided on the mounting portion 26 of the valve body 4v is screwed in from below to fix it in place. As a result, one end of the movable part 3 is fixed to one (lower) leaf spring member 5.

[0039] Next, the other (upper) leaf spring member 5 is fitted into the mounting circular hole 31u formed in the housing body 15, and the upper bolt portion 3pu of the plunger 3p in the movable part 3 is inserted into the circular hole formed on the inner circumference 5c of the other leaf spring member 5. Then, the fixing ring 32 is screwed into the mounting circular hole 31u to fix the leaf spring member 5, and the upper nut 34 is screwed onto the upper bolt portion 3pu from above to fix the plunger 3p and the leaf spring member 5.

[0040] In this way, when providing the leaf spring members 5..., by preparing at least two, the inner circumference 5c of one leaf spring member 5 is fixed to one end 3s of the axial direction Fs of the movable part 3, and the outer circumference 5f is fixed to one end 2s of the axial direction Fs of the solenoid part 2, while the inner circumference 5c of the other leaf spring member 5 is fixed to the other end 3t of the axial direction Fs of the movable part 3, and the outer circumference 5f is fixed to the other end 2t of the axial direction Fs of the solenoid part 2. In this way, both ends of the movable part 3 in the axial direction Fs can be supported by the same leaf spring member 5..., so that stable support can be achieved, control accuracy can be improved, and optimal performance can be obtained from the viewpoint of preventing particle generation.

[0041] In addition, in Figure 1, 2hu is the upper surface portion that closes the upper end opening of the housing 2h, and a position sensor 51 for detecting the upper end position of the plunger 3p is installed on the inner surface of this upper surface portion 2hu.

[0042] Next, the operation of the linear motor valve 1 according to this embodiment, including how to use it, will be described with reference to Figures 1 and 6.

[0043] Figure 6 shows an example of use in which the linear motor valve 1 is connected to the gas piping P. The linear motor valve 1 has a solenoid section 2 connected to a power supply section (not shown) and a control section (not shown) that controls this power supply section.

[0044] First, let's consider the case where the solenoid section 2 is not energized. In this case, no magnetic field is generated for the movable section 3, so due to the elastic action of the leaf spring members 5, 5, the valve body section 4v and the valve seat section 4s are pressed together as shown in Figure 1, and the valve mechanism section 4 is closed (OFF). That is, the linear motor valve 1 is in a normally closed state, and the gas piping P is shut off.

[0045] On the other hand, let's consider the case where the power supply unit and control unit are turned ON, and power supply control is performed on the solenoid unit 2. In this case, the control unit applies a control signal to the power supply unit. A PWM (pulse wedge modulation) signal can be used as the control signal. As a result, the magnitude of the drive current (excitation current) of the solenoid unit 2 changes based on the PWM signal.

[0046] As a result, a magnetic field corresponding to the magnitude of the drive current is generated by the solenoid unit 2, and the movable part 3 is displaced upward (in the direction of the arrow Fsu in Figure 6). The displacement of the movable part 3 is detected by the position sensor 51, and this position signal (position data) is fed back to the control unit. In this way, the valve mechanism unit 4 is controlled to a valve opening degree corresponding to the desired gas flow rate.

[0047] In other words, since the valve opening changes proportionally to the magnitude of the drive current, if the magnitude of the drive current is gradually increased, the magnetic field generated by the excitation of the solenoid unit 2 will also gradually increase, and the movable part 3 will gradually be displaced upward.

[0048] Figure 6 shows the state in which the movable part 3 is displaced upward by a stroke Lh from the closed state by the energization control of the solenoid part 2. In correspondence with this stroke Lh, the inner circumference 5c of the leaf spring members 5, 5 is also elastically displaced upward, and the valve body part 4v, which is integrated with the movable part 3, is displaced upward by a stroke Lh, and the valve mechanism part 4 is set to the valve opening degree (open state) corresponding to the control signal. In Figure 6, the dotted arrow Fg... indicates the gas flow path.

[0049] Therefore, according to the linear motor valve 1 of this embodiment, the basic configuration includes a ring-shaped leaf spring member 5 whose inner circumference 5c is relatively displaceable in the axial direction Fs, and by arranging this leaf spring member 5 coaxially with respect to the solenoid part 2, the outer circumference 5f of the leaf spring member 5 is fixed to the housing 2h, and the inner circumference 5c of the leaf spring member 5 is fixed to the movable part 3. As a result, relatively large flow rates can be controlled, and control accuracy in the low flow rate range can be increased, thus ensuring stable control accuracy from small to large flow rates. Furthermore, since there is no sliding part between the movable part 3 that displaces in the axial direction and the housing 2h that supports this movable part 3, no particles are generated. As a result, adverse effects from particles, i.e., foreign matter remaining inside the fluid control valve and causing problems such as failure of the fluid control valve, are avoided, and there is no risk of adverse effects on the controlled object such as the fluid, thus ensuring high reliability and long lifespan.

[0050] The example embodiment illustrates a linear motor valve 1 configured as a normally closed type, but it can also be similarly applied to a normally open type (fully open when not energized). Figure 7 shows an embodiment when the valve is changed to a normally open type. This figure shows an example where the arrangement positions of the leaf spring members 5, 5 are changed, and when not energized, the valve mechanism 4 is in the open state, i.e., the valve mechanism 4 is in the same state as in Figure 6. On the other hand, when energized, the movable part 3 is displaced downward (in the direction of arrow Fsd), and the valve mechanism 4 becomes fully closed. The example shows a case where the arrangement positions of the leaf spring members 5, 5 are changed, but it can also be similarly implemented by changing the shape of the leaf spring member 5.

[0051] Thus, by configuring the system so that it can be changed to a normally closed type or a normally open type by changing the shape or position of the leaf spring member 5, it is possible to easily convert between a normally closed type and a normally open type simply by changing the shape or position of the leaf spring member 5.

[0052] On the other hand, Figure 8 shows a modified example of the linear motor valve 1 according to this embodiment. In the modified linear motor valve 1, when providing the leaf spring member 5, the inner circumference side 5c is fixed to one end 3s side of the axial direction Fs in the movable part 3, i.e., to the valve body part 4v side, and the outer circumference side 5f is fixed to one end 2s side of the axial direction Fs in the solenoid part 2.

[0053] Therefore, the other end 3t of the movable part 3 in the axial direction Fs is supported by a general bearing member 61 as shown in Figure 8. For this purpose, an upper surface portion 2hs is integrally formed on the upper end of the housing 2h, that is, on the upper end side of the housing body portion 15, and a collar-shaped bearing member 61 made of, for example, a low-friction material is fixed to the center of this upper surface portion 2hs, and this bearing member 61 supports the cylindrical shaft portion 3ps integrally formed on the upper end (other end) of the plunger 3p.

[0054] In this modified example, when providing the leaf spring member 5, if the inner circumference 5c is fixed to one end 3s of the axial direction Fs in the movable part 3 and the outer circumference 5f is fixed to one end 2s of the axial direction Fs in the solenoid part 2, the leaf spring member 5 can be positioned closest to the valve body 4 fixed to one end 3s of the movable part 3. This ensures stable operation even when combined with other support members (such as bearing members) that support the other end of the movable part 3, ensures the required control accuracy, and moreover, sufficiently prevents the generation of particles.

[0055] Although preferred embodiments, including modified examples, have been described in detail above, the present invention is not limited to these embodiments, and the details of the configuration, shape, materials, quantity, numerical values, etc., can be arbitrarily changed, added, or deleted without departing from the spirit of the present invention.

[0056] For example, while it is desirable for the leaf spring member 5 to be integrally formed from a single piece of stainless steel Ms, the selection of the material is not limited to stainless steel Ms, and the use of other materials with similar functions is not excluded. Furthermore, although an example was given in which multiple slits 11... are formed between the outer circumference 5f... and the inner circumference 5c... to provide an elastic strip 12... of a predetermined length that allows the inner circumference 5c... to be elastically displaced in the axial direction Fs relative to the outer circumference 5f..., the number and shape of the slits 11... and the number and shape of the elastic strip 12... can be arbitrarily selected. Although gas was given as an example of a fluid, various fluids such as air and liquid can be applied. Furthermore, although examples were given in which the leaf spring member 5... is placed on both the one end 3s and the other end 3t of the movable part 3, and which is placed only on the one end 3s, the case where it is placed only on the other end 3t of the movable part 3 or in the middle of the movable part 3 is not excluded. Furthermore, the quantity of magnets 3m (3mu, 3md) and the number of leaf spring members 5... used per location are arbitrary. [Industrial applicability]

[0057] The linear motor valve according to the present invention can be used as various linear motor valves, such as flow control valves, for continuously controlling the flow rate of fluids such as gas. [Explanation of symbols]

[0058] 1: Linear motor valve, 2h: Housing, 2: Solenoid section, Fs: Axial direction, 3p: Plunger, 3m: Magnet, 3: Movable section, 3s: One end of movable section, 4v: Valve body section, 4: Valve mechanism section, 5c: Inner circumference side, 5: Leaf spring member, 5f: Outer circumference side, Ms: Stainless steel material, 11…: Slit, 12…: Elastic strip section, 2s: One end of solenoid section, 3t: Other end of movable section, 2t: Other end of solenoid section

Claims

1. A linear motor valve comprising a cylindrical solenoid portion fixed to a housing, a movable portion having a plunger axially arranged inside the solenoid portion and a magnet fixed around the outer circumference of the plunger, and which moves forward and backward in the axial direction by energization control of the solenoid portion, and a valve mechanism portion having a valve body fixed to one end of the movable portion, wherein at least the inner circumference of a ring-shaped leaf spring member is axially displaceable, and the outer circumference of the leaf spring member is fixed to the housing by arranging the leaf spring member coaxially with respect to the solenoid portion, and the inner circumference of the leaf spring portion is fixed to the movable portion.

2. The linear motor valve according to claim 1, characterized in that the leaf spring member is integrally formed from a single piece of stainless steel material.

3. The linear motor valve according to claim 2, characterized in that the leaf spring member has a plurality of slits formed between the outer circumference and the inner circumference, thereby forming zigzag elastic strips of one or more predetermined lengths on the inner circumference that can be elastically displaced in the axial direction relative to the outer circumference.

4. The linear motor valve according to claim 1, characterized in that the leaf spring member is fixed with its inner circumference to one end in the axial direction of the movable part and its outer circumference to one end in the axial direction of the solenoid part.

5. The linear motor valve according to claim 1, characterized in that at least two leaf spring members are provided, the inner circumference of one leaf spring member is fixed to the one end of the movable part in the axial direction, and the outer circumference is fixed to the one end of the solenoid part in the axial direction, and the inner circumference of the other leaf spring member is fixed to the other end of the movable part in the axial direction, and the outer circumference is fixed to the other end of the solenoid part in the axial direction.

6. The linear motor valve according to claim 1, characterized in that the leaf spring member is configured to be changeable between a normally closed type and a normally open type by changing its shape or arrangement position.

7. The linear motor valve according to claim 1, characterized in that the magnets are arranged in one or more directions in the axial direction of the plunger.

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