JP2001200949A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce weight of a solenoid valve, and to reduce electric power consumption. SOLUTION: This solenoid valve includes an electromagnet 11 having a soft magnetic iron core 12 and a coil 13 and an armature actuated by these core and coil to open and close a passage 16 for a medium. The passage penetrates through a ferrite core having a supply opening part terminating on the front side of the ferrite core. The armature is constituted as a thin plate armature 14 elastically held on the outlet side of the passage against magnetic force. This armature has a seal 21 for closing the passage when this thin plate armature is attracted downward on the side turning to a channel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet having a soft magnetic iron core and a coil, and an armature operated by the core and the coil, for opening or closing a flow path for a medium. Or a solenoid valve. In particular, the invention relates to a valve for a gaseous medium, for example pressurized air, for activating a pressure cuff of a sphygmomanometer. Therefore, the following description will be made mainly in relation to pressurized air, but is not limited to pressurized air. Among other various materials, a ferrite core is particularly suitable as a soft magnetic core. Hereinafter, a ferrite core will be described as an example,
It is not limited to such an example.

[0002] To perform an automated blood pressure measurement, first,
It is necessary to pressurize the cuff on the arm or wrist with air and then release the pressure, usually at each step. Between steps, the pressure in the cuff and the heartbeat are measured, and the blood pressure is determined according to a vibration measurement.

[0003]

To release the pressurized air in steps, a solenoid valve connected to the cuff is usually used. Especially for mobile blood pressure measuring devices operated offline, it is necessary to keep the power consumption to a minimum. It is also desirable to minimize the weight of the valve and reduce the total weight of the device.

[0004] A solenoid valve is known in which a piston included in a valve body provided with a seal for sealing a flow path at a free end is operated by an armature against a spring force. Such valves have a relatively large moving mass member, which results in a proportionally higher power consumption. Also, these valves are relatively inactive. Since the pressurized air in the sphygmomanometer is reduced only in small steps, a valve that responds quickly is preferred. A movable armature is often provided in the flow path of the medium to be controlled, which tends to clog the valve.

The present invention is based on the problem of improving a solenoid valve of the above type so that it is light in weight and consumes little power.

According to the present invention, the object is to provide a magnetic core having a supply opening which terminates on the front side of the magnetic core, wherein the flow path passes through the magnetic core and the armature is formed as a thin plate armature. It is held elastically against the magnetic force at the supply opening side, and further supports the seal on the side facing the channel, and this seal closes the flow path when pulled below the thin plate armature Can be solved. Such a structure has the advantage that the armature can close the flow path without using an intermediate element. Since the mass of the moving parts is very small, weight and power consumption can be minimized. Furthermore, since no armature is provided in the flow of the medium to be controlled, there is no risk of functional failure due to clogging.

Particularly, it is effective to configure the mount and the seal as one part. To further simplify production, at least a part of the armature sheet can be surrounded by molded plastic.

It is particularly practical to manufacture the elastic mount and seal in one piece. It is also possible for at least part of the armature sheet to be embedded in plastic by injection molding.

[0009] The type of elastomer to be used can be of any type as long as it has the required elastic properties. For example, it is effective to manufacture the mount and the seal from silicone. Silicone has the resiliency required for a portable blood pressure monitor in the desired temperature range of 0-50 ° C.

According to another embodiment, the channel is configured as a nozzle, on which a soft magnetic iron core is superimposed,
The core can be held in place. Such an embodiment has the advantage that a separate mount is not required for the soft magnetic iron core. Furthermore, if possible, the power consumption of the valve can be further reduced by tapering the cross section of the nozzle in the sealing area.

Advantageously, the nozzle is constructed as a protruding part of the housing and locks the housing of the valve or of the device to which the valve is mounted. Furthermore, a thin plate of the armature can be locked in the housing. Finally, according to the invention, it is proposed to lock the soft magnetic iron core, coil and sheet armature in the cover of the housing for locking the valve or in the cover of the device for mounting the valve. Such a device greatly reduces the required number of parts, and facilitates easy assembly of the valve.

With the solenoid valve according to the present invention,
Obviously, it is possible to provide a compact and lightweight valve. Since the moving mass is small, the power consumption is also reduced, and the valve responds quickly due to the low inertia of the armature sheet with the sealing element and the seal.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

[0014]

The valve shown in the drawings has an electromagnet 11 with a soft magnetic iron core, for example a ferrite core 12, and an electric coil 13. Thin plate armature 1
4 and the armature has a double arrow 1
5 so that it can be tilted.
For clarity, the figures do not show the electrical connections of the coils.

The ferrite core has a channel 16 for the medium to be controlled, for example, pressurized air. Housing 17
On the opposite side of the thin plate armature 14, a connecting pipe socket 18 is provided, by means of which the valve can be connected to a hose or a tube. The flow path enters the front side 19 of the ferrite core 12 facing the thin plate armature 14.

The thin plate armature has a resilient seal 21 on the side of the supply opening 20 of the channel 16 on the front side 19. The seal fits over the top of the opening so that the flow path is closed when the sheet armature 14 is in the position drawn down. With the valve shown in the open position, the medium is free to pass through the channel.

The coil 13 is formed in a cylindrical shape around the ferrite core 12 in a usual manner. However, basically other structures are also possible. As soon as current flows through the coil, the sheet metal armature 14 is drawn down toward the ferrite core, closing the valve.

The details of the valve are as follows.
2 is configured to be a nozzle 26 configured as a projection at the bottom portion. The ferrite core is preferably superimposed on the projection having the port bore, and is preferably retained on the projection by frictional force. Such holding can be performed by making the diameter of the protrusion slightly larger than the diameter of the open opening of the ferrite core.
However, the projections may extend in the axial direction and have the same outer diameter.

The sheet metal part is locked in the housing by an elastic mount 23 made of an elastic plastic material, for example silicone. Mount 23 also
It is locked in the bottom part of the housing 22 by two pins 24. These details are shown in the housing cover 2
5 is configured to be able to hold both the ferrite core with the coil and the thin plate armature in their mating position.

As can be seen in particular from FIGS. 5 to 7, the plastic mount and the seal 21 for the flow path form one piece. The elastic plastic mount is
It extends at least to the area of the sheet armature corresponding to the flow path of the valve and closes the valve in the pull-down position.
These details can be arranged such that the edges of the sheet armature are mounted in or on the resilient mount.
The resilient mount extends approximately to the flow path opening of the valve, thereby leaving the sheet armature free to move and the mount forming the seal is:
The channel opening can be closed when the magnet is energized.

The mount can be connected to a sheet armature in an area corresponding to the channel opening. That is, it can be glued or snap-fitted to the opening in the sheet armature. Thus, the shift of the seal on the sheet armature does not prevent the valve from closing properly.

The resilient mount may extend at least to the flow path on the side facing the magnet and the flow path to form a seal. Also, as shown in the figure, on the side opposite to the magnet, the seal may extend to the area of the flow path, and the seal may have a protrusion extending in the direction of the flow path. The sheet armature 14 has an opening through which the projection penetrates, thus forming a seal 21. Thus, the sheet metal part of the armature can be simultaneously connected to the locking element in this region. The diameter of this projection is slightly larger than the opening in the sheet armature or in FIG.
As can be seen, it is preferred to have an undercut. Thereby, the seal portion of the mount can be securely locked to the thin plate armature. Thus, the shift of the seal portion 21 can be prevented. The free end of the projection that interferes with the flow path is larger than the cross section of the opening, so that the projection can close the opening.

In manufacturing the thin plate armature, the elastic plastic material of the mount is molded around the thin plate armature, and the thin plate armature and the mount are connected. In this way, a robust, mobile thin plate armature with a flow path seal can be manufactured. Naturally, the seal 21 and the mount 23 are separately attached to the thin plate armature 14.
It is also possible to connect to.

In the above description, the valve has been described as having its own housing, but instead of the valve housing, the housing of the device incorporating the valve therein should have the necessary mounting device. Is also possible. In particular, it is also possible for the nozzle to be a housing part of a device for locking the ferrite core. In this way, the number of parts for the valve itself, in particular the number of moving parts, can be kept very small. Instead of using a valve housing, it is also possible to simply incorporate the valve in the housing, which simplifies manufacturing and keeps costs low. A valve can be provided which consists only of the housing bottom, the electromagnet and the sealing element. These parts are held in place by the housing cover. As such, the valve is extremely robust and lightweight, making it suitable for use in portable, portable devices, such as wrist-wrapped sphygmomanometers.

[Brief description of the drawings]

FIG. 1 is a sectional view of a valve according to the present invention.

FIG. 2 is a plan view of a valve.

FIG. 3 is a cross-sectional view of only the valve housing cover of the valve without a ferrite core.

FIG. 4 is a perspective view showing a bottom portion of the housing.

FIG. 5 is a side view of a thin plate armature with an elastomer locking device.

FIG. 6 is a bird's-eye view according to FIG. 5;

FIG. 7 is a perspective view of the thin plate armature shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Electromagnet 12 Ferrite core 13 Electric coil 14 Thin plate armature 15 Arrow 16 Channel 17 Housing 18 Socket 19 Front side 20 Opening 21 Seal 22 Housing 23 Mount 24 Pin 25 Housing cover 26 Nozzle

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H106 DA07 DA13 DB02 DB12 DB26 DB33 DC05 DC17 DD03 EE22 EE34 GA15 GC29 KK04

Claims (9)

[Claims] 1. A soft magnetic iron core (12) and a coil (1).
A solenoid valve for opening and closing a flow path (16) for the medium, comprising an electromagnet (11) comprising 3) and an armature actuated by these cores and coils, The flow channel (16) penetrates the soft magnetic iron core (12), and the armature is configured as a thin plate armature (14) elastically locked against magnetic force. A solenoid valve having a seal on an opposite side, wherein the seal closes a channel when the sheet armature is pulled downward. 2. The solenoid valve according to claim 1, wherein the thin plate armature is locked by at least one mount made of a resilient plastic material. 3. The solenoid valve according to claim 1, wherein the elastic mount and the seal form a single part. 4. The armature according to claim 1, wherein at least a part of the thin plate armature is embedded in a plastic molding compound of the mount.
The solenoid valve according to any one of the above. 5. The solenoid valve according to claim 1, wherein the plastic material is silicone. 6. The nozzle according to claim 1, wherein the flow path is configured as a nozzle, and a soft magnetic iron core is superimposed on the nozzle so that the nozzle can be engaged with the nozzle. The solenoid valve according to any one of the above. 7. A housing (22) for locking the valve,
Or as a projection on the housing of the device, the nozzle (26)
The solenoid valve according to any one of claims 1 to 6, wherein a valve is attached to the projection. 8. A solenoid valve according to claim 1, wherein a thin plate armature (14) is locked in said housing (22). 9. The soft magnetic iron core, coil and sheet armature are locked in their mounting position by a cover of a housing (25) for locking the valve or by a cover of a housing on which the valve is mounted. A solenoid valve characterized by the following.