JPH028568A - Valve device - Google Patents

Abstract

PURPOSE:To form a device in small size further contriving its cost down by integrally forming two valve mechanisms so that they can be controlled being associated by a single control system. CONSTITUTION:Fitting a valve seat member 7 to one side end of a housing 3, storing the first valve unit 4, provided with a needle 4a adapted to this valve seat member 7, in a hollow part of the housing 3 and providing the second valve hole 12, communicating with the second valve chamber 11, in the other side end of the housing 3 and the second valve unit 16, opening and closing the second valve hole 12, in its outside, the first valve unit 4 is connected to the second valve unit 16 by a connecting member 17 consisting of shape memory alloy. In this way, a device can be formed in small size by enabling the two valve units 4, 16 to be controlled being associated by a single control system, while the cost down can be contrived by decreasing a number of part items.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a valve device used, for example, as a pneumatic control valve of an automatic blood pressure monitor.

[Conventional technology and its problems]

FIG. 3 is a circuit diagram showing the general configuration of an automatic blood pressure monitor using a conventional valve device, and FIG. 4 is a graph showing the relationship between time and pressure during blood pressure measurement.

The operation of the automatic blood pressure monitor will be explained with reference to these figures.

When the power is turned on with the compression band (cuff) 21 wrapped around the upper arm of the subject, the compression Ja 22 starts pressurizing and the solenoid valve 23 is activated to close the exhaust hole 23a.

A portion of the pressurized air is discharged from the constant m/ft valve 24, but since the amount of air sent from the compressor 22 is greater than the amount discharged, the internal pressure gradually decreases from point A as shown in Figure 4. Rise. Point B where the internal pressure is sufficiently higher than the commonly known systolic blood pressure (e.g. 300 mm
1g), this is detected by the pressure sensor 26 and the compressor 22 is stopped.

The internal air is exhausted from the constant flow valve 24, and the internal pressure drops at a constant rate. Note that the discharge amount of the constant flow valve 24 can be adjusted manually.

When the internal pressure decreases to a certain value, the pressure on the subject's upper arm weakens and a vascular noise (Korokotov sound) occurs, but as the internal pressure decreases further, the vascular murmur gradually weakens and eventually disappears.

By reading the values of the pressure sensor 26 when the acoustic sensor 25 built into the compression cuff 21 first senses blood vessel noise and when it no longer senses it, the systolic blood pressure (value at point M) of this subject can be determined. You can know the diastolic blood pressure (value at point N).

After measuring the diastolic blood pressure, the internal pressure is at the 0 point (e.g. 40 m
mHg), the electromagnetic valve 23 is activated, the internal air is rapidly exhausted, and the compression cuff 21 becomes ready to be removed.

In a blood pressure monitor that measures blood pressure using an indirect method (non-invasive method), a flow control valve (corresponding to the constant flow valve 24) for lowering the pressure within the compression cuff 21 at a constant rate and a blood pressure measurement device are used. A valve device consisting of an exhaust temperature j'n valve (corresponding to the solenoid valve 23) is required to quickly exhaust the air after the measurement and prepare for the next measurement.

However, in the past, these flow rate control valves and exhaust control valves were separate, so the piping route between them was complicated, and the storage space was large, making it difficult to downsize the blood pressure monitor.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a valve device that can make an applied device (for example, a blood pressure monitor) more compact.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a first valve chamber and a second valve chamber each communicating with an inflow port, and a first valve chamber biased by a first biasing means and provided in the first valve chamber. energized by a first valve body that keeps the hole in a normally closed state and a second energizing means;
A second valve body that keeps a second valve hole provided in the second valve chamber always open; and a connecting member made of a shape memory alloy that connects the first valve body and the second valve body; When the second valve body contracts, the first valve hole opens after the second valve body closes the second valve hole.
The structure is characterized in that the urging force of the urging means is set larger than the urging force of the second urging means.

[For production]

At all times, the second valve chamber is open to the atmosphere, and the air that has flowed into the first and second valve chambers from the inlet is discharged from the second valve hole.

When the shape of the connecting member made of a shape memory alloy changes and contracts due to a temperature change, the first valve body and the second valve body are attracted to each other, but the biasing force of the first biasing means becomes the second biasing force. Since it is set larger than the urging force of the means, the second
The valve body closes the second valve hole against the urging force of the second urging means.

As the connection member further contracts, the first valve element opens the first valve hole against the urging force of the first urging means, and the air that has flowed in from the inlet is exhausted from the first valve hole.

When the temperature changes in the opposite direction from this state and the connecting member expands, the first valve body closes the first valve hole, and then the second valve body opens the second valve hole.

〔Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front sectional view of the valve device I. FIG.

A housing 3 provided with an inlet 2 is made of a conductive material, and a hollow portion thereof serves as a cylinder chamber 5 that accommodates a first valve body 4 having a needle 4a. The first valve chamber 6 provided for controlling the flow rate is a part of the cylinder chamber 5, and the first valve chamber 6 is provided in the through hole 4b provided in the first valve body 4 and in the sliding tube 9. It communicates with the inlet 2 via the through hole 9a.

A valve seat member 7 having a through hole in the center is fitted into one side end of the housing 3, and the through hole serves as a first valve hole 8 that communicates the first valve chamber 6 with the outside. There is. Further, the electric bridge 15 is fixed to the housing 3 by the valve seat member 7.

The first valve body 4 is installed so as to be able to slide along the sliding tube 9, but is normally biased by a compression spring 10 as a first biasing means, so that the needle 4a is pressed against the valve seat member 7. are in contact. Therefore, the first valve hole 8 is closed at this time.

On the other hand, at the other side end of the housing 3, a sealing member 13 made of synthetic rubber having a through hole that becomes the second valve chamber 11 and the second valve hole 12 is attached to the second valve chamber 1 by a fixing member 14 made of resin.
The second valve chamber 11 and the cylinder chamber 5 are fixed to the housing 3 so that the axis of the valve chamber 1 and the axis of the cylinder chamber 5 are parallel to each other, and the second valve chamber 11 and the cylinder chamber 5 communicate with each other.

The seal member 13 keeps the cylinder chamber 5 airtight and also serves as a seat for the compression spring 10.

An electrode 18 made of an annular phosphor bronze plate having one tongue piece on the inside and a pull-out piece 18a on the outside is screwed to the fixed member 14, and the tongue piece of the electrode 18 opens and closes the second valve hole 12. This serves as a second valve body 16.

The second valve body 16 is slightly bent outward so as to keep the second valve hole 12 open at all times, and is biased outward by a second biasing means, that is, by its own elastic force. However, this biasing force is smaller than the biasing force of the compression spring 10.

The first valve body 4 and the second valve body 16 arranged in this manner are connected by a connecting member 17 made of a shape memory alloy. The total length of the connecting member 17 is such that the first valve body 4 closes the first valve hole 8 and the second valve body 16 closes at all times (at room temperature) as described above.
The length is set such that the second valve hole 12 is located at a position where the second valve hole 12 is opened.

Next, the operation of the valve device 1 will be explained with reference to FIG. 2, which is a circuit diagram showing a schematic configuration of an automatic blood pressure monitor using the valve device 1 configured as described above.

The blood pressure measurement method and the relationship between internal pressure and time during measurement are the same as in the conventional example. That is, when the power is turned on with the compression band (cuff) 21 wrapped around the upper arm of the person to be measured, the pressure m machine 22 starts applying pressure. At the same time, the valve device l
The electrode 15, the housing 3, and the sliding tube 9 are energized.
, first valve body 4, connection member 17, second valve body 16, electrode 18
Current flows through a path consisting of When current flows,
The connecting member 17 generates heat due to Joule heat, and as the temperature rises, the connecting member 17 contracts and deforms.

That is, the total length of the connecting member 17 becomes shorter, and the first valve body 4 and the second valve body 16 tend to approach each other. However, as described above, since the biasing force of the compression spring 10 exceeds the elastic biasing force of the second valve body 17 itself, the second valve body 16 is first drawn inward and the second valve hole 12 is closed. .

As the connection member 17 further contracts, the first valve body 4 slides against the compression spring 10, creating a gap between the needle 4a and the valve seat member 7. That is, the first valve hole 8 is opened and the air that has flowed in from the inlet 2 is discharged little by little. However, since the amount of air sent from the compressor 22 is greater than the amount of air discharged, the internal pressure gradually increases from point A as shown in FIG.

The internal pressure is at a preset sufficiently high point B (e.g. 300
mmHg), this is detected by the pressure sensor 26, the compressor 22 is stopped, and the internal pressure drops as the air is discharged from the first valve hole 8. Note that the amount of discharge from the first valve hole 8 can be easily adjusted by controlling the magnitude of the applied current.

The systolic and diastolic blood pressures are measured based on the vascular noise during the stage of the internal pressure drop, and then the internal pressure reaches the 0 point (for example, 4
When the pressure drops to 0nn++Hg), the pressure sensor 26 detects this and stops energizing the valve device 1.

As a result, when the connecting member 17 cools and expands, the first valve body 4 first slides and closes the first valve hole 8, and then the second valve hole 12 opens, causing the internal air to flow out. is discharged at once from the second valve hole 12 through the second valve chamber 11, returning to the initial state.

According to the above-described embodiment, it is possible to open and close the second valve hole 12 and adjust the throttle of the first valve hole 8 by simply controlling the current, so the control system is simplified and is particularly suitable for automation. suitable.

In the above-described embodiment, the contraction of the connecting member 17 made of a shape memory alloy was caused by applying electricity, but the temperature of the connecting member 17 may be changed by introducing cold or hot air or the like.

In the above-described embodiment, the electrode 18 was attached to the fixing member 14 with a screw, but instead of using the screw, an annular cap may be inserted from the left side in FIG. 1 to press down the electrode 118. The first valve chamber 6 was communicated with the inlet 2 through the cylinder chamber 5 and the through hole 4b.
The communication may be made without intervening. In addition, the structure, shape, material, etc. of each part can be changed in various ways.

〔Effect of the invention〕

According to the present invention, two valve mechanisms are integrated so that they can be controlled in conjunction with one control system, making it possible to reduce the size of the device and also to reduce costs by reducing the number of parts.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a valve device that is an embodiment of the present invention, FIG. 2 is a circuit diagram schematically showing a blood pressure monitor using a valve device that is an embodiment of the present invention, and FIG. 3 is a conventional blood pressure monitor. FIG. 4 is a circuit diagram schematically showing the meter, and is a graph showing the relationship between time and internal pressure during blood pressure measurement. DESCRIPTION OF SYMBOLS 1... Valve device, 2... Inflow port, 4... First valve body,
6... First valve chamber, 8... First valve hole, 10... Compression spring (first biasing means), 11... Second valve chamber, 12...
・Second valve hole, 16...Second valve body (second biasing means), 1
7... Connection department employee

Claims (1)

[Claims] (1) A first valve chamber and a second valve chamber each communicating with the inflow port, and a first valve chamber that is biased by the first biasing means and keeps the first valve hole provided in the first valve chamber in a normally closed state. A valve body, a second valve body that is biased by a second biasing means and keeps a second valve hole provided in the second valve chamber in an open state at all times, and a first valve body and a second valve body are connected. a connecting member made of a shape memory alloy, and when the connecting member contracts, the urging force of the first urging means is applied to a second valve so that the first valve hole opens after the second valve body closes the second valve hole. A valve device whose biasing force is set to be larger than the biasing force of the biasing means.