阅读说明：本技术 电磁阀、血压计以及设备 (Electromagnetic valve, sphygmomanometer and equipment ) 是由 佐野佳彦 西冈孝哲 小野原博文 洼田岳 于 2019-01-24 设计创作，主要内容包括：本发明的电磁阀具有包括端板部(3b)以及侧板部(3c)的磁轭(3)、极片(4)、螺线管线圈(7)、以及由板状的磁性材料构成的隔板(6)。极片(4)在一端部(4e)具有开口(4o),在另一端部(4f)具有与开口(4o)连通的第一流体出入口(11)。施力部(5)以使隔板(6)沿一个方向(Z方向)并行移动的方式向隔板(6)与极片(4)的一端部(4e)分离的方向对隔板(6)施力。在不工作时,变为开口(4o)开放的打开状态,在工作时,由螺线管线圈(7)产生的磁力抵抗施力部(5)的作用力,从而能够变为隔板(6)与极片(4)的一端部(4e)接近而堵塞开口(4o)的关闭状态。(The electromagnetic valve of the present invention has a yoke (3) having an end plate portion (3b) and a side plate portion (3c), a pole piece (4), a solenoid coil (7), and a separator (6) made of a plate-like magnetic material. The pole piece (4) has an opening (4o) at one end (4e) and a first fluid inlet/outlet (11) communicating with the opening (4o) at the other end (4 f). The urging section (5) urges the separator (6) in a direction in which the separator (6) is separated from the one end section (4e) of the pole piece (4) so that the separator (6) moves in parallel in one direction (Z direction). When the opening (4o) is opened during non-operation, the magnetic force generated by the solenoid coil (7) resists the acting force of the force application part (5) during operation, and the partition plate (6) and one end part (4e) of the pole piece (4) approach to close the opening (4o) and can be in a closed state.)

1. A solenoid valve for allowing or cutting off the flow of a fluid,

comprising:

a yoke including an end plate portion having an annular peripheral edge, and a side plate portion connected to the peripheral edge of the end plate portion and annularly surrounding a space adjacent to one side of the end plate portion;

a pole piece that extends in one direction from one end portion of the space existing on the one side to the other end portion on the opposite side, the pole piece having an opening at the one end portion, the other end portion having a first fluid inlet and outlet that communicates with the opening through the inside of the pole piece, the pole piece being orthogonal to the end plate portion of the yoke;

a solenoid coil accommodated in an annular space between the pole piece and the side plate portion of the yoke;

a partition plate that is opposed to the end plate portion of the yoke via the space, has a size that spans an annular edge of the side plate portion of the yoke, and is made of a plate-shaped magnetic material; and

a biasing portion that biases the separator in a direction in which the separator is separated from the one end portion of the pole piece so that the separator moves in parallel in the one direction,

when the solenoid coil is in a non-energized state, that is, when not operating, the separator is separated from the one end portion of the pole piece by the urging force of the urging portion and the opening is opened,

when the solenoid coil is energized, that is, operated, the separator can be brought into a closed state in which the separator is close to the one end portion of the pole piece and closes the opening by the magnetic force generated by the solenoid coil against the biasing force of the biasing portion.

2. The solenoid valve of claim 1,

the pole piece is integrally formed with the yoke.

3. The solenoid valve according to claim 1 or 2,

the magnetic material forming the separator is permalloy.

4. The electromagnetic valve according to any one of claims 1 to 3,

an elastic body for blocking the opening is integrally mounted on a portion of the separator opposite to the opening of the one end portion of the pole piece.

5. The solenoid valve of claim 4,

the pole piece has a recess at the one end portion that opens toward the elastic body mounted on the separator, and at the bottom of the recess, the opening is open.

6. The electromagnetic valve according to any one of claims 1 to 5,

the solenoid valve includes a closed case that collectively covers the yoke, a portion of the pole piece extending to the one space, the solenoid coil, the partition plate, and the biasing portion in a liquid-tight manner in a state where the other end portion of the pole piece is exposed to the outside,

a second fluid inlet and outlet is provided so as to penetrate the outer wall of the hermetic case.

7. The solenoid valve of claim 6,

the hermetic case includes: the yoke has a first end wall along an outer surface of the end plate portion of the yoke, a second end wall along a back surface of the separator facing an opposite side of the end plate portion, and an annular outer peripheral wall connecting a peripheral portion of the first end wall and a peripheral portion of the second end wall.

8. The solenoid valve of claim 7,

the other end portion of the pole piece provided with the first fluid inlet/outlet is disposed so as to protrude outward from the first end wall of the sealed case.

9. Solenoid valve according to claim 7 or 8,

the second fluid inlet/outlet is disposed so as to protrude outward from the first end wall, the second end wall, or the outer peripheral wall of the sealed case.

10. The electromagnetic valve according to any one of claims 7 to 9,

the urging portion includes a coil spring disposed along an annular space between the side plate portion of the yoke and the outer peripheral wall of the hermetic case.

11. A sphygmomanometer for measuring blood pressure at a measured site,

comprising:

a main body;

a cuff worn on the measurement site;

a pump mounted on the main body and configured to supply fluid to the cuff through a flow path;

the electromagnetic valve according to any one of claims 1 to 10, mounted on the main body, and installed between the pump or the flow path and the atmosphere;

a pressure control unit that controls a pressure of the cuff by supplying fluid to the cuff through the flow path by the pump and/or discharging fluid from the cuff through the electromagnetic valve; and

and a blood pressure calculation unit that calculates a blood pressure based on a pressure of the fluid contained in the cuff.

12. An apparatus capable of measuring blood pressure at a measured portion,

comprising:

a main body;

a cuff worn on the measurement site;

a pump mounted on the main body and configured to supply fluid to the cuff;

the solenoid valve according to any one of claims 1 to 10, mounted on the main body;

a pressure control unit that controls a pressure of the cuff by supplying fluid to the cuff by the pump and/or discharging fluid from the cuff through the electromagnetic valve; and

and a blood pressure calculation unit that calculates a blood pressure based on a pressure of the fluid contained in the cuff.

Technical Field

The present invention relates to a solenoid valve, and more particularly, to a solenoid valve that is opened and closed by a magnetic force of a solenoid coil. The present invention also relates to a sphygmomanometer and a blood pressure monitor having such a solenoid valve.

Background

Conventionally, as an electromagnetic valve used in a blood pressure monitor, for example, an electromagnetic valve disclosed in patent document 1 (japanese patent application laid-open No. h 08-203730) is known. The solenoid valve has a half-transverse-n-shaped frame and a yoke attached so as to close an open end of the frame. A substantially cylindrical bobbin (coil frame) and a solenoid coil wound around the bobbin are accommodated therein. In addition, a rod-shaped movable core is slidably inserted into the bobbin. A fixed core having a flow port through which a fluid flows is disposed on a bottom plate of the frame facing the yoke. One end of the movable iron core is opposite to the flow opening of the fixed iron core. When the solenoid coil is in a non-energized state, that is, when not operating, one end of the movable iron core is separated from the flow port of the fixed iron core by the urging force of the spring. When the solenoid coil is energized, that is, when the solenoid coil is operated, the movable core moves in the bobbin against the biasing force of the spring by the magnetic force generated by the solenoid coil, and one end of the movable core closes the flow port of the fixed core. Thereby, the electromagnetic valve is opened and closed.

Disclosure of Invention

Problems to be solved by the invention

However, according to the recent trend of health intention, there is an increasing demand for blood pressure measurement in a state where a sphygmomanometer is always worn on a wrist like a wristwatch. In this case, it is desirable to miniaturize the structural components such as the solenoid valve as much as possible.

However, in the solenoid valve as disclosed in patent document 1, since the movable iron core has a rod shape and moves in the longitudinal direction thereof, there is a problem that the size of the solenoid valve (particularly, the size of the movable iron core in the longitudinal direction) increases.

Accordingly, an object of the present invention is to provide a solenoid valve that can be configured in a small size. The present invention also provides a sphygmomanometer and a blood pressure monitor having such an electromagnetic valve.

Technical scheme for solving problems

In order to solve the above problems, the solenoid valve of the present invention is a solenoid valve for allowing or cutting off the flow of a fluid,

comprising:

a yoke including an end plate portion having an annular peripheral edge, and a side plate portion connected to the peripheral edge of the end plate portion and annularly surrounding a space adjacent to one side of the end plate portion;

a pole piece that extends in one direction from one end portion of the space existing on the one side to the other end portion on the opposite side, the pole piece having an opening at the one end portion, the other end portion having a first fluid inlet and outlet that communicates with the opening through the inside of the pole piece, the pole piece being orthogonal to the end plate portion of the yoke;

a solenoid coil accommodated in an annular space between the pole piece and the side plate portion of the yoke;

a partition plate that is opposed to the end plate portion of the yoke via the space, has a size that spans an annular edge of the side plate portion of the yoke, and is made of a plate-shaped magnetic material; and

a biasing portion that biases the separator in a direction in which the separator is separated from the one end portion of the pole piece so that the separator moves in parallel in the one direction,

when the solenoid coil is in a non-energized state, that is, when not operating, the separator is separated from the one end portion of the pole piece by the urging force of the urging portion and the opening is opened,

when the solenoid coil is energized, that is, operated, the separator can be brought into a closed state in which the separator is close to the one end portion of the pole piece and closes the opening by the magnetic force generated by the solenoid coil against the biasing force of the biasing portion.

In the present specification, the "yoke" and the "pole piece" are members that function to guide magnetic lines of force, which are well known in the field of electromagnets, and are each made of a magnetic material (particularly, a ferromagnetic material such as iron is preferable).

The shape of the peripheral edge of the end plate portion of the yoke widely includes an annular shape such as a circle, a rounded quadrangle (a quadrangle with rounded corners), and the like. The same applies to the annular shape of the side plate portion of the yoke.

The "annular edge" of the side plate portion of the yoke is an edge on the opposite side of the end plate portion.

The "other end portion" of the pole piece may protrude from the end plate portion of the yoke or may be stopped at an outer surface of the end plate portion (a surface facing the opposite side of the space on the one side out of two surfaces of the end plate portion).

As the open/close state of the valve, there is an intermediate state in which the flow rate is controlled in accordance with the amount of current supplied to the solenoid between the closed state and the open state.

In the solenoid valve of the present disclosure, when the solenoid coil is in a non-energized state, that is, when not operating, the diaphragm is separated from the one end portion of the pole piece by the biasing force of the biasing portion, and the opening is opened. In this open state, the fluid passing through the pole piece is allowed to flow. The solenoid valve becomes a normally open valve.

When the solenoid coil is energized, that is, when it is operated, the magnetic force generated by the solenoid coil resists the biasing force of the biasing portion, and the separator can be brought into a closed state in which the separator is close to the one end portion of the pole piece and closes the opening. Specifically, when the solenoid coil is in an energized state (during operation), the magnetic lines of force generated by the solenoid coil circulate through, for example, the following paths (magnetic paths): the magnetic yoke passes through the side plate portion of the magnetic yoke to the periphery of the end plate portion, passes through the end plate portion from the periphery of the end plate portion to a portion of the end plate portion orthogonal to the pole piece, passes through the pole piece from the orthogonal portion to the one end portion of the pole piece, passes through the one end portion to a portion of the pole piece close to the separator plate, and further passes through the separator plate to the annular edge of the side plate portion of the magnetic yoke. If the direction of energization of the solenoid coil is reversed, the magnetic lines of force generated by the solenoid coil circulate the path in the opposite direction. Thereby, the solenoid coil generates a magnetic force against the biasing force of the biasing portion to the diaphragm. The separator can be brought into a closed state in which the separator is close to the one end of the pole piece and blocks the opening by the magnetic force. When the separator is in the closed state, the flow of the fluid passing through the pole piece is shut off. As described above, in this solenoid valve, the solenoid coil can be opened or closed depending on whether the solenoid coil is in a non-energized state (at the time of non-operation) or the solenoid coil is in an energized state (at the time of operation). This allows or blocks the flow of fluid through the pole piece (i.e., the solenoid valve).

In the solenoid valve, a plate-shaped separator is configured to move in parallel in one direction in a direction approaching to or separating from the one end portion of the pole piece in a posture facing the end plate portion of the yoke, so as to allow or block the flow of fluid. That is, unlike the conventional example (the movable iron core is rod-shaped and moves in the longitudinal direction), in this electromagnetic valve, the plate-shaped diaphragm moves in one direction perpendicular to the plate surface of the diaphragm. Therefore, the size of the solenoid valve can be reduced in the one direction in which the partition plate moves. As a result, the solenoid valve can be made compact.

In the solenoid valve according to an embodiment, the pole piece is integrally formed with the yoke.

In the solenoid valve according to this embodiment, since the pole piece and the yoke are integrally formed, the magnetic resistance between the pole piece and the yoke is small, and the efficiency of the magnetic circuit passing through them is improved. In addition, the air tightness between the pole piece and the magnetic yoke can be improved, and air leakage can be prevented.

In the solenoid valve according to one embodiment, the magnetic material forming the separator is permalloy.

Here, the "permalloy" means a Ni-Fe alloy.

In the solenoid valve according to this embodiment, the partition plate is plate-shaped and made of permalloy, and therefore, the solenoid valve can be configured to be lighter than, for example, a rod-shaped movable iron core. In this case, when the posture (direction) of the solenoid valve is variously changed with respect to the vertical direction, the characteristics (e.g., the energization current and the flow rate characteristics) are hardly affected.

Further, if the member for driving the valve to open and close is a rod-shaped movable iron core, since it has a large weight, when the posture (direction) of the solenoid valve is changed variously with respect to the vertical direction, the gravity component received by the movable iron core along the sliding direction changes greatly along with this, and the characteristics of the solenoid valve are greatly affected.

In the solenoid valve according to one embodiment, an elastic body for closing the opening is integrally attached to a portion of the separator that faces the opening at the one end portion of the pole piece.

In the present specification, the "elastomer" refers to an object made of an elastic material (flexible material) such as silicone rubber, nitrile rubber (NBR), Ethylene Propylene Diene Monomer (EPDM), or the like.

In the solenoid valve according to this embodiment, when the open state is shifted to the closed state, the elastic body of the separator is brought close to the opening at the one end of the pole piece. This makes it possible to obtain stable characteristics of the current (or drive voltage) and the flow rate. In the closed state, the elastic body of the separator reliably blocks the opening at the one end of the pole piece.

Preferably, the elastic body is attached to the separator by press fitting, adhesion, or insert molding. Thus, the elastic body can be easily and integrally attached to the separator.

In the solenoid valve according to one embodiment, the pole piece has a recess opened toward the elastic body attached to the separator at the one end, and the opening is opened at a bottom of the recess.

In the solenoid valve according to this embodiment, when the valve is in the closed state, the elastic body attached to the separator closes the opening in a state of being accommodated in the recess at the one end portion of the pole piece. Therefore, the elastic body can stably close the opening.

In the solenoid valve of an embodiment, characterized in that,

the solenoid valve includes a closed case which collectively covers the yoke, a portion of the pole piece extending to the one space, the solenoid coil, the partition plate, and the biasing portion in a liquid-tight manner in a state where the other end portion of the pole piece is exposed to the outside,

a second fluid inlet and outlet is provided so as to penetrate the outer wall of the sealed casing.

The solenoid valve according to this embodiment is attached to the flow path and is adapted to allow or block the flow of fluid through the flow path. If the solenoid valve is in the open state, fluid can flow through the solenoid valve, for example, from the second fluid inlet/outlet to the first fluid inlet/outlet or in the opposite direction through the opening at the one end portion of the pole piece (the partition plate is in the open state apart from the one end portion). If the solenoid valve is in a closed state, the opening (the partition plate is in a closed state in proximity to the one end portion) is shut off, and therefore, fluid does not flow between the second fluid inlet and the first fluid inlet through the solenoid valve.

In an electromagnetic valve according to an embodiment, the hermetic case includes: the yoke has a first end wall along an outer surface of the end plate portion of the yoke, a second end wall along a back surface of the separator facing an opposite side of the end plate portion, and an annular outer peripheral wall connecting a peripheral edge portion of the first end wall and a peripheral edge portion of the second end wall.

The "outer surface" of the end plate portion refers to a surface facing the opposite side of the one-side space, out of the two extended surfaces of the end plate portion. The "back surface" of the separator is a surface of the two surfaces of the separator that faces the opposite side of the end plate portion of the yoke.

In the solenoid valve according to this embodiment, the dimension from the first end wall to the second end wall of the closed casing is set to be small, so that the solenoid valve can have a flat outer shape along the first and second end walls. This profile is suitable for the following structures: for example, the solenoid valve (the sealed case) is mounted along a wiring board, and the solenoid valve (the sealed case) and the wiring board are flat as a whole.

In the electromagnetic valve according to an embodiment, the other end portion of the pole piece provided with the first fluid inlet/outlet is disposed so as to protrude outward from the first end wall of the closed casing.

In the solenoid valve according to this embodiment, the flow path is easily connected to the first fluid inlet/outlet so that fluid can flow therethrough.

In the solenoid valve according to an embodiment, the second fluid inlet/outlet is disposed so as to protrude outward from the first end wall, the second end wall, or the outer peripheral wall of the closed casing.

In the solenoid valve according to this embodiment, the flow path is easily connected to the second fluid inlet/outlet so that fluid can flow therethrough. In particular, in the case where the second fluid inlet/outlet is disposed so as to protrude outward from the outer peripheral wall of the sealed case, the second fluid inlet/outlet can be prevented from protruding outward from the second end wall of the sealed case, and the solenoid valve can be made thinner. In addition, in the case where the second fluid port is disposed so as to protrude outward from the first end wall of the sealed casing, the second fluid port may protrude in the same direction as the first fluid port. Thus, for example, the following mounting structure is possible: the sealing case is mounted on the upper surface of the wiring board such that both the second fluid inlet and the first fluid inlet extend downward so as to penetrate the wiring board.

In the solenoid valve according to an embodiment, the biasing portion includes a coil spring disposed along an annular space between the side plate portion of the yoke and an outer peripheral wall of the hermetic case.

In the solenoid valve according to this embodiment, the biasing portion can be simply configured by a small number of components (i.e., coil springs).

In another aspect, the sphygmomanometer of the present disclosure is used for measuring blood pressure at a measurement site, characterized in that,

comprising:

a main body;

a cuff worn on the measurement site;

a pump mounted on the main body and supplying fluid to the cuff through a flow path;

the electromagnetic valve, load on the above-mentioned body, install between above-mentioned pump or above-mentioned flow path and atmosphere;

a pressure control unit that controls a pressure of the cuff by supplying a fluid to the cuff through the flow path by the pump and/or discharging the fluid from the cuff through the electromagnetic valve; and

and a blood pressure calculation unit that calculates a blood pressure based on the pressure of the fluid contained in the cuff.

In the sphygmomanometer of the present disclosure, typically, the main body and the cuff are integrally worn at the measurement site. In this worn state, the pressure control unit controls the pressure of the cuff by supplying fluid to the cuff through the flow path by the pump to pressurize the cuff and/or by discharging fluid from the cuff through the electromagnetic valve. The blood pressure calculation unit calculates a blood pressure based on the pressure of the fluid contained in the cuff (oscillometric method). Here, in the sphygmomanometer, the electromagnetic valve is configured by the electromagnetic valve that can be configured in a small size according to the present disclosure. Therefore, the main body and the whole sphygmomanometer can be made small.

In yet another aspect, the apparatus of the present disclosure, capable of measuring blood pressure at a measured site, is characterized in that,

comprising:

a main body;

a cuff worn on the measurement site;

a pump mounted on the main body and configured to supply fluid to the cuff;

the electromagnetic valve is mounted on the main body;

a pressure control unit that controls a pressure of the cuff by supplying a fluid to the cuff by the pump and/or discharging the fluid from the cuff through the electromagnetic valve; and

and a blood pressure calculation unit that calculates a blood pressure based on the pressure of the fluid contained in the cuff.

In the apparatus of the present disclosure, typically, the main body and the cuff are integrally worn at the measured site. In this wearing state, the pressure control unit controls the pressure of the cuff by supplying fluid to the cuff by the pump and/or discharging fluid from the cuff through the electromagnetic valve. The blood pressure calculation unit calculates a blood pressure based on the pressure of the fluid contained in the cuff (oscillometric method). Here, in this apparatus, the above-described solenoid valve is constituted by the solenoid valve which can be constituted in a small size of the present disclosure. Therefore, the main body and the whole sphygmomanometer can be made small.

Effects of the invention

As can be seen from the above, the solenoid valve, the sphygmomanometer and the device of the present invention can be configured in a small size.

Drawings

Fig. 1 is a perspective view showing an external appearance of a solenoid valve according to an embodiment of the present invention.

Fig. 2 is a view showing the solenoid valve as viewed obliquely in an exploded state.

Fig. 3 is a view showing the solenoid valve of fig. 2 viewed from another direction.

Fig. 4 is a view showing an example of a cross-sectional structure when the electromagnetic valve is cut by a surface including a fluid inlet and outlet.

Fig. 5 is a plan view showing a partition plate provided in a housing of the solenoid valve.

Fig. 6 is a diagram showing a flow of fluid passing through the solenoid valve when the solenoid valve is in an open state.

Fig. 7 is a diagram showing forces applied to respective portions of the solenoid valve when the solenoid valve is in a closed state.

Fig. 8 is a diagram showing a frame configuration of a sphygmomanometer according to an embodiment of the present invention, which includes the electromagnetic valves as opening and closing valves.

Fig. 9A is a diagram showing an operation flow of the sphygmomanometer.

Fig. 9B is a diagram illustrating a flow of the pressurization speed control included in the operation flow of fig. 9A.

Fig. 10 is a diagram showing a relationship between the driving force and the opening degree of the solenoid valve.

Fig. 11(a) and 11(B) are views showing an example of a solenoid valve in which a housing of the solenoid valve is deformed.

Fig. 12(a) and 12(B) are views showing another example of the solenoid valve in which the housing of the solenoid valve is deformed.

Detailed Description

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

Fig. 1 shows an appearance of a solenoid valve (denoted by reference numeral 2 as a whole) according to an embodiment of the present invention viewed obliquely. Fig. 2 shows the solenoid valve 2 in an exploded state. Fig. 3 shows the solenoid valve 2 of fig. 2 viewed from another direction. For convenience of understanding, XYZ rectangular coordinates are shown in fig. 1 to 3, and fig. 4 to 7 and fig. 11 to 12 described later. Hereinafter, for convenience of explanation, the Z direction is sometimes referred to as the thickness direction, and the XY direction is sometimes referred to as the plane direction.

(Structure of solenoid valve)

As shown in fig. 1, the solenoid valve 2 includes a housing 10 as a housing. The housing 10 includes a cover housing 10A disposed on one side (+ Z side) in the thickness direction and a main housing 10B disposed on the opposite side (-Z side) in the thickness direction. In this example, the cap case 10A has a disk-shaped second end wall 10-2 forming an outer wall, and a cylindrical portion 10A (forming a second fluid inlet/outlet 12 for passing a fluid) protruding outward (+ Z side) from the center of the second end wall 10-2. The main casing 10B has a rectangular (square in this example) plate-like first end wall 10-1 and a substantially cylindrical outer peripheral wall 10-3 connected to the first end wall 10-1. As shown in fig. 3, a through hole 10w into which a pole piece (pole piece)4 described later is fitted is provided in the center of the first end wall 10-1. A through hole 10u through which a wiring (a lead wire not shown) passes is provided on one side (in this example, the side on the-Y side) of the first end wall 10-1. Connection terminals 71, 72, 73, and 74 (see fig. 3) made of metal (copper or the like) are integrally provided at four corners of the outer surface of the first end wall 10-1.

In this example, the cover case 10A is formed by integrally molding a nonmagnetic plastic material. The main housing 10B is formed by integrally molding (insert molding) a non-magnetic plastic material together with the connection terminals 71, 72, 73, and 74. In this example, the second end wall 10-2 of the cover case 10A is welded to the outer peripheral wall 10-3 of the main case 10B. However, the second end wall 10-2 may be screwed into the outer peripheral wall 10-3.

As is apparent from fig. 2 and 3, a yoke 3, a pole piece 4 integrally attached to (an end plate portion 3b of) the yoke 3 in a direction perpendicular thereto, a solenoid coil 7, a coil spring 5 as an urging portion, a spacer 6, and an elastic body 8 integrally formed with the spacer 6 are provided inside a housing 10 of the solenoid valve 2.

As shown in fig. 2, the yoke 3 includes an end plate portion 3b having an annular (circular in this example) peripheral edge, and a side plate portion 3c connected to the peripheral edge of the end plate portion 3b and annularly surrounding a space SP1 adjacent to one side (+ Z side) of the end plate portion 3 b. As shown in fig. 3, a through hole 3w is provided in the center of the end plate portion 3b, and the pole piece 4 is fitted into the through hole 3 w. A through hole 3u through which a wiring (not shown) passes is provided in a portion of the peripheral edge portion of the end plate portion 3B corresponding to the through hole 10u of the first end wall 10-1 of the main casing 10B. The shape of the peripheral edge of the end plate portion 3b of the yoke 3 is not limited to a circle, and may be a rounded quadrangle (a quadrangle with rounded corners), or the like. The same applies to the annular shape of the side wall portion of the side plate portion 3 c.

In this example, the outer diameter of the side plate 3c of the yoke 3 is set smaller than the inner diameter of the outer peripheral wall 10-3 of the main case 10B. Thus, in the assembled state shown in fig. 4, an annular space SP2 in which coil spring 5 is accommodated is formed between side plate portion 3c of yoke 3 and outer peripheral wall 10-3 of main case 10B.

As is apparent from fig. 2 and 3, the pole piece 4 has a substantially cylindrical shape as a whole. The pole piece 4 has a protrusion 4a fitted into the through hole 3w of the yoke 3 and protruding outward in the axial direction (Z direction), and a body 4b having an outer diameter larger than that of the protrusion 4 a. That is, the pole piece 4 is orthogonal to the end plate portion 3b of the yoke 3, and extends in one direction (Z direction) from one end portion 4e of the space SP1 existing on one side (+ Z side) to the other end portion 4f on the opposite side (-Z side). In this example, the pole piece 4 has a circular-planar-shaped recess 4d at one end 4e, which opens toward the elastic body 8 of the separator 6. At the bottom of the pit 4d, a circular opening 4o is opened. The other end 4f of the pole piece 4 is provided with a circular first fluid inlet/outlet 11 that passes through the pole piece 4 and communicates with the opening 4 o.

In this example, the yoke 3 and the pole piece 4 are each made of SUM24L (sulfur-clad free cutting steel) as a magnetic material. In this example, the protrusion 4a of the pole piece 4 is press-fitted into the through hole 3w of the yoke 3, and the yoke 3 and the pole piece 4 are integrally formed. This reduces the magnetic resistance between the pole piece 4 and the yoke 3, and improves the efficiency of the magnetic circuit using these as paths. In addition, the air tightness between the pole piece 4 and the yoke 3 can be improved, and air leakage can be prevented. The yoke 3 and the pole piece 4 may be formed as an integral body that is spatially continuous.

As is apparent from fig. 2 and 3, the solenoid coil 7 has a thick cylindrical outer shape. The solenoid coil 7 is sized to be accommodated in an annular space SP1 between the pole piece 4 and the side plate portion 3c of the yoke 3. A pair of wires, not shown, extend from the solenoid coil 7.

The coil spring 5 has a substantially cylindrical profile. In the assembled state shown in fig. 4, the coil spring 5 is disposed along the annular space SP2 between the side plate portion 3c of the yoke 3 and the outer peripheral wall 10-3 of the main case 10B, and biases the spacer 6 in a direction away from the one end portion 4e of the pole piece 4 (i.e., in the + Z direction) so that the spacer 6 moves in parallel in one direction (Z direction). In fig. 4, the force f2 of the coil spring 5 urging the diaphragm 6 is schematically shown by an arrow. Thus, the biasing portion can be simply configured by a small number of components (i.e., the coil spring 5).

As can be seen from fig. 2 and 3, the separator 6 has a substantially disk-like outer shape. In this example, as is apparent from fig. 5 (showing the planar shape of the separator 6), four circular through holes 6s, 6t, 6u, and 6v are provided between the center 6c and the peripheral edge 6e in the radial direction of the separator 6 at equal angular intervals (90 ° intervals in this example) in the circumferential direction. Thus, the fluid can flow between the back surface (surface facing the + Z side) 6a side and the inner surface (surface facing the-Z side) 6b side of the separator 6 through the through holes 6s, 6t, 6u, and 6 v.

As can be seen from fig. 4, the partition plate 6 has a size that spans the annular edge 3e of the side plate portion 3c of the yoke 3. As a result, the outer diameter of the spacer 6 substantially matches the outer diameter of the coil spring 5. Gaps are provided between the outer diameter of the partition plate 6 and the inner diameter of the outer peripheral wall 10-3 of the main casing 10B to enable the partition plate 6 to move in parallel in one direction (Z direction) within the outer peripheral wall 10-3.

In this example, the separator 6 is substantially disc-shaped as described above, and is made of permalloy (an alloy of Ni — Fe) as a magnetic material. This enables the spacer 6 to be lighter than a rod-shaped movable iron core, for example. In this case, when the posture (direction) of the solenoid valve 2 is changed variously with respect to the vertical direction, the characteristics (e.g., the energization current and the flow rate characteristics) are less likely to be affected by the posture of the solenoid valve.

As is apparent from fig. 2 and 3, a substantially columnar elastic body 8 for closing the opening 4o is integrally attached to the center of the separator 6 so as to face the opening 4o formed in the recess 4d of the one end 4e of the pole piece 4. In this example, the elastic body 8 is made of silicone rubber. However, the elastic body 8 is not limited to this, and may be made of another elastic material (flexible material) such as nitrile rubber (NBR) or Ethylene Propylene Diene Monomer (EPDM). The outer diameter of the elastic body 8 is set to be larger than the diameter of the opening 4o and smaller than the inner diameter of the recess 4 d. Thus, in a closed state described later, the elastic body 8 can reliably close the opening 4o in a state of being accommodated in the recess 4d of the one end portion 4e of the pole piece 4.

In this example, the elastic member 8 is integrally attached to the partition plate 6 by insert molding. This enables the diaphragm 6 and the elastic body 8 to be easily integrally attached. However, the present invention is not limited to this, and the elastic body 8 may be attached to the separator 6 by press-fitting, bonding, or the like.

(assembling steps of solenoid valve)

The solenoid valve 2 is assembled from the state (disassembled state) shown in fig. 2 and 3, for example, by the following steps.

i) First, the yoke 3 and the pole piece 4 are accommodated in the main casing 10B. At this time, the protrusion 4a of the pole piece 4 is inserted into the through hole 10w of the first end wall 10-1 of the main case 10B. Meanwhile, through hole 3u of end plate portion 3B of yoke 3 is made to correspond to through hole 10u of first end wall 10-1 of main case 10B.

ii) then, the solenoid coil 7 is accommodated in an annular space SP1 between the pole piece 4 and the side plate portion 3c of the yoke 3. At this time, a pair of lead wires (not shown in the figure) extending from solenoid coil 7 are passed through hole 3u of end plate portion 3B of yoke 3 and through hole 10u of first end wall 10-1 of main case 10B, and are led out to the outside of main case 10B.

iii) then, the pair of lead wires drawn out are respectively soldered to any two of the four connection terminals 71, 72, 73, 74 provided on the outer surface of the first end wall 10-1. Further, the remaining two of the four connection terminals 71, 72, 73, 74 are left as dummy terminals.

iv) then, the yoke 3 is hermetically bonded to the main case 10B with an adhesive, and the solenoid coil 7 is hermetically bonded to the yoke 3. At this time, the through hole 3u of the end plate portion 3B of the yoke 3 and/or the through hole 10u of the first end wall 10-1 of the main case 10B through which the pair of wires pass are filled with an adhesive, thereby achieving airtightness.

v) then, the coil spring 5 is accommodated in an annular space SP2 (see fig. 4) between the side plate portion 3c of the yoke 3 and the outer peripheral wall 10-3 of the main case 10B.

vi) next, the partition plate 6 is disposed so as to face the end plate portion 3b of the yoke 3 from one side (+ Z side) of the coil spring 5 via the space SP 1. Further, the partition plate 6 is pressed by the lid case 10A against the urging force f2 of the coil spring 5, and the second end wall 10-2 of the lid case 10A is hermetically welded to the outer peripheral wall 10-3 of the main case 10B by ultrasonic welding.

Thus, the solenoid valve 2 is assembled as shown in fig. 4.

In the assembled state of fig. 4, the case 10 collectively and airtightly covers the yoke 3, the body portion 4b of the pole piece 4, the solenoid coil 7, the spacer 6 (and the elastic body 8), and the coil spring 5 as a closed case in a state where the projection portion 4a (including the other end portion 4f) of the pole piece 4 is exposed to the outside. First end wall 10-1 of main case 10B is along the outer surface (surface facing the-Z side) of end plate portion 3B of yoke 3, and second end wall 10-2 of cover case 10A is along the back surface (surface facing the + Z side) 6a of spacer 6. In particular, in this example, the projection 4a of the pole piece 4 forming the first fluid port 11 projects outward from the first end wall 10-1, and the cylindrical portion 10a forming the second fluid port 12 projects outward from the second end wall 10-2. Therefore, the first fluid inlet and outlet 11 and the second fluid inlet and outlet 12 can be easily connected to, for example, the downstream side and the upstream side of the flow path so that the fluid can flow therethrough. This allows the solenoid valve 2 to be easily attached to the flow path.

(opening and closing operation of solenoid valve)

When the solenoid valve 2 is used, the solenoid valve 2 is attached to the flow path by connecting the first fluid inlet/outlet 11 and the second fluid inlet/outlet 12 to the downstream side and the upstream side of the flow path so that the fluid can flow therethrough, respectively, as described above. As shown in fig. 6, in the solenoid valve 2, when the solenoid coil 7 is in a non-energized state, that is, when not operating, the separator 6 is separated from the one end 4e of the pole piece 4 by the biasing force f2 of the coil spring 5, and thereby the elastic body 8 is separated from the opening 4o of the one end 4e of the pole piece 4, and the opening 4o is opened. That is, the solenoid valve 2 is normally opened.

In this open state, fluid is allowed to circulate through the solenoid valve 2. If the solenoid valve 2 is in the open state, fluid enters from the second fluid inlet/outlet 12 as indicated by an arrow LC1, for example. The fluid passes through the through holes 6s, 6t, 6u, and 6v of the separator 6 as indicated by arrows LC2s and LC2u, then passes through the gap between the dimples 4d and the elastic body 8 of the one end 4e of the pole piece 4, passes through the opening 4o of the one end 4e, and flows out of the first fluid inlet/outlet 11 as indicated by arrow LC 3. As described above, the fluid can flow through the solenoid valve 2 from the second fluid inlet/outlet 12 toward the first fluid inlet/outlet 11 or in the opposite direction.

When the solenoid coil 7 is energized, that is, when it is operated, as shown in fig. 7, the magnetic force F0 (the resultant force of the magnetic forces F0 and F0 … … applied to the respective portions of the separator 6) generated by the solenoid coil 7 approaches the one end 4e of the pole piece 4 against the biasing force F2 of the coil spring 5 and the reaction force F2 '(the resultant force of F2 and F2' is expressed as a resistance force F2) received by the elastic body 8 from the notch 4d of the one end 4e of the pole piece 4, and thereby the separator 6 and the one end 4e of the pole piece 4 can be brought into a closed state in which the opening 4o of the one end 4e of the pole piece 4 is closed by. Specifically, when the solenoid coil 7 is in an energized state (during operation), the magnetic lines of force generated by the solenoid coil 7 mainly circulate through the following paths (magnetic paths), as shown by the two-dot chain line M in fig. 7, for example: the side plate 3c of the yoke 3 reaches the periphery of the end plate 3b, passes through the end plate 3b from the periphery of the end plate 3b to the portion of the end plate 3b orthogonal to the pole piece 4, passes through the pole piece 4 from the orthogonal portion to the one end 4e of the pole piece 4, passes through the one end 4e to the portion of the pole piece 4e adjacent to the separator 6, and further passes through the separator 6 to the annular edge 3e of the side plate 3c of the yoke 3. If the solenoid coil 7 is energized in the opposite direction, the magnetic lines of force generated by the solenoid coil 7 circulate the path in the opposite direction. Thereby, the solenoid coil 7 generates a magnetic force F0 against the diaphragm 6 against the urging force F2 of the coil spring 5. The separator 6 is brought close to the one end 4e of the pole piece 4 by the magnetic force F0, and the opening 4o can be closed by the elastic body 8. In the closed state, the flow of the fluid through the pole piece 4 is shut off. In this way, in the solenoid valve 2, the solenoid coil 7 can be switched to the open state or the closed state depending on whether the solenoid coil 7 is in the non-energized state (at the time of non-operation) or the solenoid coil 7 is in the energized state (at the time of operation). This allows or blocks the flow of fluid through the pole piece 4, that is, the solenoid valve 2.

In the closed state shown in fig. 7, the inner surface 6b of the separator 6 abuts on the peripheral end surface 4e1 of the one end 4e of the pole piece 4. However, the fluid can pass through the through holes 6s, 6t, 6u, 6v of the separator 6 as indicated by arrows LX2s, LX2u, pass between the inner surface 6b and the peripheral end surface 4e1 of the separator 6, and enter the gap between the dimples 4d of the one end 4e of the pole piece 4 and the elastic body 8. Therefore, the influence of the pressure (back-side pressure) P0 of the fluid applied to the back surface 6a of the separator 6 on the flowing current (or driving voltage) and flow rate characteristics is reduced.

For example, fig. 10 shows the relationship between the magnetic force F0 generated by the solenoid coil 7 and the valve opening degree for the solenoid valve 2. The valve opening degree is represented by 100% when the valve is fully opened and 0% when the valve is fully closed. For the sake of simplicity, the description will be made with omitting intermediate states between the open state and the closed state of each valve.

Since the first magnetic force F0 of the solenoid valve 2 is 0, it is at the point ST21 where the opening degree is 100%. If the amount of energization of the solenoid coil 7 is increased to increase the magnetic force F0 as shown by the solid line XQ1, the magnetic force F01 in this example moves from the open state to the closed state. In this example, it is temporarily stopped at a point ST22 where the magnetic force F0 is slightly larger than F01. Here, in the solenoid valve 2, if the amount of energization of the solenoid coil 7 is reduced to reduce the magnetic force F0, the solenoid valve moves backward on the solid line XQ1, and returns to the open state at approximately the magnetic force F01. Then, the process returns to the initial point ST 21.

For example, the resistance force of the coil spring 5 or the like is set to F2-5.0 × 10^-2[N]. Then, the back-side pressure P0 becomes 0mUnder the condition of mHg and the opening-side pressure (the pressure of the fluid applied to the opening 4o from the first fluid inlet/outlet 11 side) P1 being 0mmHg, the magnetic force when moving from the open state to the closed state (or conversely when moving from the closed state to the open state) along the arrow XQ1 in fig. 10 is F01 ≈ F2 ≈ 5.0 × 10^-2[N]Similarly, F01 ≈ F2 ≈ 5.0 × 10 under the conditions that the back side pressure P0 is 300mmHg and the opening side pressure P1 is 300mmHg^-2[N]. The diameter of the opening 4o is 0.5mm, and the diameter of the notch 4d of the one end 4e of the pole piece 4 is 1.2 mm. For example, under the conditions that the back side pressure P0 is 0mmHg and the opening side pressure P1 is 300mmHg, the area of the opening 4o (S0) is S0 ═ pi Φ²Therefore, the pressing force of the opening side pressure P1 on the partition plate 6 (F1) is F1 to 7.84 × 10^-3[N]Thus, F01 ≈ F1+ F2 ≈ 5.8 × 10^-2[N]。

As the open/close state of the solenoid valve 2, there is an intermediate state in which the flow rate is controlled in accordance with the amount of current supplied to the solenoid between the closed state and the open state. When the state is shifted from the open state to the closed state, the elastic body 8 of the separator 6 approaches the opening 4o of the one end 4e of the pole piece 4. This makes it possible to obtain stable characteristics of the current (or drive voltage) and the flow rate.

Here, in the solenoid valve 2, the plate-like separator 6 is configured to move in parallel in one direction (Z direction) in a direction approaching or separating from the one end 4e of the pole piece 4 in a posture facing the end plate portion 3b of the yoke 3, so as to allow or block the flow of the fluid. That is, unlike the conventional example (the movable iron core is rod-shaped and moves in the longitudinal direction thereof), in the solenoid valve 2, the plate-shaped diaphragm 6 moves in one direction (Z direction) perpendicular to the plate surface of the diaphragm 6. Therefore, the solenoid valve 2 can be downsized in one direction (Z direction) in which the diaphragm 6 moves. As a result, the structure of the solenoid valve 2 can be reduced in size.

In particular, in this solenoid valve 2, by setting the size of the housing 10 from the first end wall 10-1 to the second end wall 10-2 small, it is possible to have a flat profile along the first and second end walls 10-1, 10-2. Such an external shape is suitable for, for example, mounting the solenoid valve 2 (housing 10) along a wiring substrate and configuring the solenoid valve 2 (housing 10) and the wiring substrate flat as a whole.

In this example, as shown in fig. 1, the thickness (dimension in the Z direction) H of the case 10 is set to about 2.5 mm. Further, dimensions W1 and W2 in the planar direction (dimensions in the XY direction) of the case 10 were set to about 5.5mm, respectively. Thus, the housing 10 has a flat outer shape. In this example, the cylindrical portion 10A of the cap case 10A is set to have a dimension of about 1.6mm protruding from the second end wall 10-2 to the + Z side. The outer diameter and the inner diameter of the cylindrical portion 10a are set to about 1.3mm and about 0.8mm, respectively. The projection 4a of the pole piece 4 projects from the first end wall 10-1 of the main case 10B toward the-Z side by a dimension of about 1.6 mm. The outer diameter and the inner diameter of the projecting portion 4a of the pole piece 4 are set to about 1.3mm and about 0.5mm, respectively. Thus, the structure of the solenoid valve 2 can be reduced in size.

As a result of the above-described reduction in size of the solenoid valve 2, the solenoid valve 2 can be reduced in weight. In particular, since the solenoid valve 2 has the plate-like spacer 6 made of permalloy instead of the rod-like movable iron core of the conventional solenoid valve, the solenoid valve 2 can be reduced in weight. Even if the attitude of the solenoid valve 2 changes variously with respect to the vertical direction, the change in the characteristics (for example, the energization current and the flow rate characteristics) is small. Therefore, the opening and closing of the solenoid valve 2 can be stably and reliably performed.

(application in Sphygmomanometers)

Fig. 8 shows a schematic block configuration of an electronic blood pressure monitor (indicated as a whole by reference numeral 100) according to an embodiment of the present invention. The sphygmomanometer 100 generally includes a cuff 20 to be worn on a measurement site such as a wrist or an upper arm, and a main body 100M.

The cuff 20 includes a fluid bag 22 for compressing the site to be measured. The fluid bag 22 and the main body 100M are connected to each other through a flexible air tube 38 so as to allow fluid to flow therethrough.

The main body 100M includes a control unit 110, a display 50, a memory 51 as a storage unit, an operation unit 52, a power supply unit 53, a pressure sensor 31, a pump 32, and an exhaust valve 33 including the solenoid valve 2. The main body 100M is provided with an oscillation circuit 310 for converting the output from the pressure sensor 31 into a frequency, a pump drive circuit 320 for driving the pump 32, and a valve drive circuit 330 for driving the exhaust valve 33. The pressure sensor 31, the pump 32, and the exhaust valve 33 are connected to an air pipe 38 through a common air pipe 39 provided in the main body 100M so as to allow fluid to flow therethrough. In this example, the exhaust valve 33 is connected to the air pipe 39 so that the second fluid inlet and outlet 12 communicates with the air pipe 39, and the first fluid inlet and outlet 11 is open to the atmosphere 900.

The display 50 includes a display screen, an indicator, and the like, and displays predetermined information (for example, a blood pressure measurement result) in accordance with a control signal from the control unit 110.

The operation unit 52 includes a power switch 52A for receiving an instruction to turn ON (ON) or OFF (OFF) the power unit 53, a measurement switch 52B for receiving an instruction to start measurement of the blood pressure, and a stop switch 52C for receiving an instruction to stop measurement. These switches 52A, 52B, and 52C input operation signals corresponding to instructions from the user to the control unit 110.

The memory 51 stores data of a program for controlling the sphygmomanometer 100, data used for controlling the sphygmomanometer 100, setting data for setting various functions of the sphygmomanometer 100, measurement result data of a blood pressure value, and the like. The memory 51 is used as a work memory or the like when the program is executed.

The control unit 110 includes a cpu (central Processing unit) and controls the overall operation of the sphygmomanometer 100. Specifically, the control unit 110 functions as a pressure control unit in accordance with a program for controlling the sphygmomanometer 100 stored in the memory 51, and performs control for driving the pump 32 and the exhaust valve 33 in accordance with an operation signal from the operation unit 52. The control unit 110 functions as a blood pressure calculation unit, calculates a blood pressure value, and controls the display 50 and the memory 51. The specific blood pressure measurement method will be described later.

The power supply unit 53 supplies electric power to the control unit 110, the pressure sensor 31, the pump 32, the exhaust valve 33, the display 50, the memory 51, the oscillation circuit 310, the pump drive circuit 320, and the valve drive circuit 330.

The pump 32 supplies air as a fluid to the fluid bladder 22 to pressurize the pressure (cuff pressure) in the fluid bladder 22 included in the cuff 20. The cuff pressure is controlled by opening and closing the air release valve 33 to release or seal air in the fluid bladder 22. The pump drive circuit 320 drives the pump 32 based on a control signal supplied from the control section 110. The valve drive circuit 330 opens and closes the exhaust valve 33 based on a control signal supplied from the control unit 110.

The pressure sensor 31 and the oscillation circuit 310 function as a pressure detection unit that detects the pressure of the cuff. The pressure sensor 31 is, for example, a piezoresistive pressure sensor, and detects the pressure (cuff pressure) in the fluid bladder 22 included in the cuff 20 via the air pipe 39 and the air tube 38. In this example, the oscillation circuit 310 oscillates according to an electric signal value based on a change in resistance due to the piezoresistive effect from the pressure sensor 31, and outputs a frequency signal having a frequency corresponding to the electric signal value of the pressure sensor 31 to the control unit 110.

Fig. 9A shows an operation flow when the user performs blood pressure measurement by the sphygmomanometer 100.

When the user instructs the start of measurement through the operation unit 52 provided in the main body 100M in a wearing state in which the cuff 20 is worn on the measurement site, the control unit 110 performs initial setting (step S1 in fig. 9A). Specifically, the control unit 110 initializes the processing memory area, closes (stops) the pump 32, and adjusts the pressure sensor 31 to 0mmHg (sets the atmospheric pressure to 0mmHg) with the exhaust valve 33 opened.

Then, the control unit 110 closes the exhaust valve 33 by the valve drive circuit 330, and then turns on (starts) the pump 32 by the pump drive circuit 320 to start the pressurization of the cuff 20 (fluid bag 22) (step S2). The controller 110 supplies air from the pump 32 to the fluid bladder 22 through the air pipe 39 and the air tube 38, and controls the pressurization speed based on the output of the pressure sensor 31 (step S3).

Specifically, in this example, as shown in the flow of the pressure rate control in fig. 9B, the control unit 110 determines whether or not the pressure rate matches the target rate (step S81 in fig. 9B). Here, if the pressing speed matches the target speed (yes in step S81), the flow returns to the flow of fig. 9A. On the other hand, if the pressing speed does not match the target speed (no in step S81 of fig. 9B), step S82 of fig. 9B is performed to determine whether the pressing speed is greater than the target speed. Here, if the pressurizing speed is higher than the target speed (yes in step S82), the drive voltage of the pump 32 is decreased from the current control voltage by a predetermined value β [ V ] (step S83). On the other hand, if the pressurizing speed is lower than the target speed (no in step S82), the drive voltage of the pump 32 is increased by a predetermined value β [ V ] from the current control voltage (step S84). Thereafter, the flow returns to fig. 9A.

Then, in step S4 of fig. 9A, the control unit 110 functions as a Blood pressure calculation unit, and attempts to calculate Blood pressure values (systolic Blood pressure sbp (systole Blood pressure) and diastolic Blood pressure dbp (diastole Blood pressure)) by a known oscillometric method based on the pulse wave signal obtained at that time (fluctuation component of the pulse wave included in the output of the pressure sensor 31).

At this time, if the blood pressure value cannot be calculated due to insufficient data (no in step S5), if the cuff pressure does not reach the upper limit pressure (predetermined to be, for example, 300mmHg for safety), the processing of steps S3 to S5 is repeated.

After the blood pressure value can be calculated in this way (yes in step S5), the control unit 110 displays the measurement result of the blood pressure value on the display 50. Further, the control unit 110 performs the following control: the pump 32 is closed and the exhaust valve 33 is opened (step S6) to exhaust the air in the cuff 20 (fluid bag 22).

Then, the control unit 110 performs the following control: the calculated blood pressure value is displayed on the display 50 (step S7), and the blood pressure value is stored in the memory 51.

The blood pressure may be calculated not during the pressurization of the cuff 20 (fluid bag 22) but during the depressurization.

In the sphygmomanometer 100, the exhaust valve 33 is constituted by the small and lightweight electromagnetic valve 2. Therefore, the main body 100M and the entire sphygmomanometer 100 can be made small and lightweight. Even if the posture of the solenoid valve 33 (solenoid valve 2) changes variously with respect to the vertical direction, the change in the characteristics (for example, the energization current and the flow rate characteristics) is small. Therefore, the opening and closing of the electromagnetic valve 33 can be stably and reliably performed, and the operation of the sphygmomanometer 100 can be stabilized.

(modification of case)

In the above example, the second fluid inlet/outlet 12 of the solenoid valve 2 is constituted by the cylindrical portion 10A protruding outward (+ Z side) from the second end wall 10-2 of the cap housing 10A. In this case, the solenoid valve 2 can be easily attached to a straight flow path. However, the present invention is not limited thereto.

For example, fig. 11(a) and 11(B) show an example of a solenoid valve 2D in which the housing 10 of the solenoid valve 2 is deformed. Fig. 11(a) shows a state in which the solenoid valve 2D is viewed from the + Z side. In addition, fig. 11(B) shows a cross-sectional structure viewed from the lower side (-Y side) in fig. 11 (a). As can be seen from this figure, in this solenoid valve 2D, the cylindrical portion 10B forming the second fluid inlet/outlet 12 is disposed so as to protrude outward (to the + X side) from the outer peripheral wall 10-3 of the main housing 10B. Otherwise, the structure is the same as that of the solenoid valve 2 (for simplicity, the structure of the partition plate 6 is simplified in fig. 11B as compared with fig. 4, 6, and 7, and this point is the same in fig. 12B described later).

When the solenoid valve 2D is in the open state, fluid enters from the second fluid inlet/outlet port 12 as shown by an arrow LD1 in fig. 11 (B). The fluid flows out from the first fluid inlet/outlet 11 to the outside as indicated by an arrow LD3 through the opening 4o of the one end portion 4e via the gap between the inner surface 6b of the separator 6 and the annular edge 3e of the side plate portion 3c of the yoke 3, the gap between the inner surface 6b of the separator 6 and the one end portion 4e of the pole piece 4, and the gap between the recess 4d of the one end portion 4e of the pole piece 4 and the elastic body 8 in this order as indicated by an arrow LD 2. Thus, the fluid can flow from the second fluid port 12 to the first fluid port 11 or in the opposite direction through the solenoid valve 2D.

When the solenoid valve 2D is in the closed state, the separator 6 is close to the one end 4e of the pole piece 4, and the opening 4o is closed by the elastic body 8, as in the solenoid valve 2.

In this solenoid valve 2D, the cylindrical portion 10b forming the second fluid inlet/outlet 12 can be prevented from protruding outward (+ Z side) from the second end wall 10-2 of the cap housing 10A. This makes it possible to reduce the thickness of the solenoid valve. For example, the main casing 10B is attached along the upper surface of a wiring board (not shown) and the protrusion 4a forming the first fluid inlet/outlet 11 extends downward so as to penetrate the wiring board, so that the solenoid valve 2D and the wiring board can be flat as a whole.

Fig. 12(a) and 12(B) show another example of the solenoid valve 2E in which the housing 10 of the solenoid valve 2 is deformed. Fig. 12(a) shows a state in which the solenoid valve 2E is viewed from the + Z side. In addition, fig. 12(B) shows a cross-sectional structure viewed from the lower side (-Y side) in fig. 12 (a). As can be seen from this figure, in this solenoid valve 2E, the cylindrical portion 10c forming the second fluid inlet/outlet 12 is disposed so as to protrude outward (to the Z side) from the first end wall 10-1 of the main housing 10B. Otherwise, the solenoid valve 2 is configured similarly.

When the solenoid valve 2E is in the open state, fluid enters from the second fluid port 12 as shown by an arrow LE1 in fig. 12 (B). The fluid flows out from the first fluid inlet/outlet 11 to the outside through the opening 4o of the one end 4e via the opening 4o of the one end 4e as indicated by the arrow LE3 via the gap between the outer peripheral wall 10-3 of the main casing 10B and the side plate 3c of the yoke 3, the gap between the inner surface 6B of the separator 6 and the annular edge 3e of the side plate 3c of the yoke 3, the gap between the inner surface 6B of the separator 6 and the one end 4e of the pole piece 4, and the gap between the recess 4d of the one end 4e of the pole piece 4 and the elastic body 8 in this order as indicated by the arrow LE 2. Thus, the fluid can flow from the second fluid port 12 to the first fluid port 11 or in the opposite direction through the solenoid valve 2E.

When the solenoid valve 2E is in the closed state, the separator 6 is close to the one end 4E of the pole piece 4, and the opening 4o is closed by the elastic body 8, as in the solenoid valve 2.

In the solenoid valve 2E, similarly to the solenoid valve 2D, the cylindrical portion 10c forming the second fluid inlet/outlet 12 can be prevented from protruding to the outside (+ Z side) from the second end wall 10-2 of the cap housing 10A. This makes it possible to reduce the thickness of the solenoid valve. In the solenoid valve 2E, the cylindrical portion 10c forming the second fluid port 12 can be made to protrude in the same direction (-Z direction) as the protrusion 4a forming the first fluid port 11. For example, the main case 10B is attached along the upper surface of a wiring board (not shown), and the cylindrical portion 10c and the protruding portion 4a are extended downward so as to penetrate the wiring board, whereby the solenoid valve 2E and the wiring board can be formed flat as a whole. In this case, the flow path connected to the solenoid valve 2E can be disposed only below the wiring board.

(applications in devices)

In the above embodiment, the solenoid valve of the present invention is applied to a sphygmomanometer, but is not limited thereto. The solenoid valve of the present invention can be applied to various devices other than a sphygmomanometer. The solenoid valve of the present invention can also be applied to a device including a functional unit that performs a blood pressure measurement function and other various functions. In this case, the structure of the apparatus can be made small and light. Further, even if the attitude of the solenoid valve is changed variously with respect to the vertical direction, the change in the characteristics (for example, the energization current and the flow rate characteristics) is small. Therefore, the electromagnetic valve can be stably and reliably opened and closed, and the operation of the apparatus can be stabilized.

The above embodiments are examples, and various modifications can be made without departing from the scope of the present invention. Although the above-described embodiments are respectively applicable to individual ones, they may be combined with each other. Further, each feature in the different embodiments may be independently established, but the features in the different embodiments may be combined with each other.

Description of the reference numerals:

2. 2D, 2E electromagnetic valve

3 magnetic yoke

4 pole piece

5 helical spring

6 baffle

7 solenoid coil

8 elastomer

10 casing

10-1 first end wall

10-2 second end wall

10-3 peripheral wall

11 first fluid port

12 second fluid port

100 sphygmomanometer