JPS6138566Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the exhaust valve of a manifold in a blood pressure measuring device.

When measuring blood pressure, it is desirable to maintain a constant rate of pressure drop in a manchet that pressurizes a part of the human body in order to improve the accuracy of blood pressure measurement. For this reason, various exhaust valves have been devised to keep the rate of pressure drop in the manifold constant. however,
Such conventional exhaust valves either have complex structures and processing, making them large and expensive, or even those with simple configurations cannot obtain constant pressure drop characteristics over the entire blood pressure measurement range. I had the inconvenience of not being able to use it.

On the other hand, for example, as described in Japanese Utility Model Application Publication No. 55-171761, the sealed cavity is divided into two chambers by an elastic diaphragm having a slit in the center, and one A constant speed exhaust valve is provided in which an air inflow path is provided in one chamber, an exhaust path is provided in the other chamber, and a movable pressing element to which the center portion of the diaphragm is pressed is provided in the other chamber. According to this, the structure is simple, and the pressure of the manifold is reduced at a substantially constant speed over the entire blood pressure measurement area.

However, when forming slits by locally cutting a predetermined length in the center of a rubber diaphragm, it is important to make the length of the slits and the shape of the slit ends the same in the thickness direction. This is extremely difficult due to changes in the degree of cutting, and this has the disadvantage that the pressure reduction characteristics of each constant speed exhaust valve vary from one another. In addition, the opening of the slit formed in the diaphragm tends to close due to the restoring force of the rubber as the differential pressure on both sides of the diaphragm decreases, that is, as the pressure of the cuff decreases, so the linearity of the cuff pressure drop rate decreases. I couldn't get enough.

The present invention was developed against the background of the above-mentioned circumstances, and its purpose is to provide a simple and compact exhaust valve for a manchette, which can maintain a constant rate of pressure decrease in the manchette. .

In order to achieve this purpose, the exhaust valve of the valve chamber in the blood pressure measuring device of the present invention includes: (1) a valve chamber communicating with the valve chamber; and (2) an exhaust valve provided on the inner wall surface of the valve chamber and communicating with the atmosphere. a valve seat in which a pair of exhaust holes are formed in a central portion and a position a predetermined distance apart from the central portion; (3) provided in the valve chamber opposite to the valve seat;
dividing the valve chamber into a high pressure chamber that communicates with the manifold and an atmospheric chamber that communicates with the atmosphere through the exhaust hole, and providing a communication hole that communicates the high pressure chamber and the atmospheric chamber at a position that does not face the exhaust hole, An elastic valve body that sequentially opens and closes the pair of exhaust holes by being pressed against the valve seat according to the pressure difference between the high pressure chamber and the atmospheric chamber.

Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

In FIG. 1, reference numeral 2 denotes a manifold, which is connected to a connecting port 6 of an exhaust valve 4 through a rubber tube 8. The exhaust valve 4 includes a bottomed cylindrical valve body 10, and a boss portion 12 is formed outwardly at the center of the bottom of the valve body 10.
A connecting port 6 at the tip of the valve body 10 communicates with the inner chamber of the valve body 10, that is, the valve chamber 14, through a passage formed in the center of the boss portion 12.

A stepped portion 16 having a diameter larger than the diameter of the valve chamber 14 is formed inside the opening of the valve body 10, and a disc-shaped elastic valve body 18 and a valve plate 20 are fitted into this stepped portion 16 in an overlapping manner. At the same time, the valve plate 20 is pressed and fixed toward the bottom of the valve body 10 by an annular fixing ring 22 screwed onto the outer periphery of the opening of the valve body 10, thereby making the valve chamber 14 airtight.

The valve plate 20 is formed with fine holes 23 and 24 that function as exhaust holes by penetrating the center portion and the peripheral portion thereof, and the valve chamber 14 side thereof is formed at a predetermined distance from the elastic valve body 18. A recess 26 forming a part of the inner wall surface of the valve chamber 14 is formed so as to maintain the same. The depth of this recess 26 is the same as that of the elastic valve body 18.
is so determined that it comes into contact with the recess 26 when it bends toward the recess 26 due to differential pressure applied to both sides thereof. Therefore, the valve plate 20 forms a valve seat for the elastic valve body 18.

The elastic valve seat 18 has a communication hole 28 having a diameter slightly larger than that of the pores 23 and 24.
An elastic plate made of synthetic rubber such as neoprene or silicone rubber is provided at a position not facing the valve chamber 14, that is, at a position opposite to the pore 24 on the outer periphery of the valve chamber 14 with the center in between. The chamber is divided into two parts: a high pressure chamber 30 which communicates with the passenger compartment 2 through 6, and an atmospheric chamber 32 which communicates with the atmosphere through pores 23 and 24, and the atmospheric chamber 32 and high pressure chamber 30 are always communicated through a communication hole 28.

The exhaust valve 4 configured as described above is mounted on the mounting plate 3.
By inserting the boss portion 12 into the hole 36 formed in the mounting plate 3 and screwing the nut 38 into the screw formed on the outer periphery of the boss portion 12, the mounting plate 3 is assembled.
It is fixed at 4.

In this way, the exhaust valve 4 is easily constructed with a small number of extremely simple shaped parts, making it easy to process and assemble, making it small and inexpensive.

The operation of this embodiment will be explained below.

When the pressure inside the manifold 2 is increased to a pressure higher than the systolic blood pressure by a pump (not shown), the pressure difference between the high pressure chamber 30 and the atmospheric chamber 32 is large. Therefore, the elastic valve body 18 is strongly pressed against the recess 26 due to the differential pressure, so the pore 23
is blocked, and the air inside the apartment 2 flows through the rubber tube 8,
High pressure chamber 30, communication hole 28, atmospheric chamber 32 and pore 2
4 to the atmosphere. As a result, the displacement is limited, and as shown by the solid line in FIG.
Along the line the pressure inside the manifold 2 decreases.

When the pressure in the high pressure chamber 30 decreases as the pressure inside the valve body 2 decreases, the differential pressure applied to the elastic valve body 18 gradually weakens and the pressure in the high pressure chamber 30 decreases.
The contact area between the elastic valve body 18 and the recess 26 is reduced.
As the pores 23 are gradually unblocked, the pores 2
Exhaust is started through 3. As a result, the exhaust area is increased as the pressure in the manifold 2 decreases, so the rate of pressure decrease in the manifold 2 is maintained regardless of the pressure drop in the manchette 2, and the pressure in the manchette 2 is reduced by the solid line in Figure 2. As shown in , it decreases away from line A.

When the pressure within the manifold 2 further decreases, the differential pressure applied to the elastic valve body 18 is significantly reduced, so that the elastic valve body 18 is completely separated from the recess 26. For this reason, the exhaust gas from the passenger seat 2 is
and 24, the exhaust area is maximized, and regardless of the pressure drop inside the manifold 2,
The rate of pressure reduction in the manifold 2 is maintained constant, and the pressure in the manifold 2 decreases along line B, as shown by the solid line in FIG. That is, the solid line in FIG. 2 is approximately straight, indicating that the rate of pressure decrease in the manifold 2 is constant.

As described above, according to this embodiment, the pair of pores 23 and 24 are formed in the valve plate 20 with high precision by machining, and the pores 23 and 24 are formed with high precision in the valve plate 20.
Since the cross section of cuff 2 does not change even if the pressure in the cuff 2 changes, the pressure in the cuff forms a substantially straight line and is suitably reduced. Furthermore, this pressure reduction characteristic can be obtained without variation even among individual exhaust valves.

In addition, line A in FIG. 2 is the pressure reduction curve of the manchette 2 when the air is exhausted only through the pores 24, and line B is the pressure reduction curve when the air is evacuated through the pores 23 and 24. be. Also,
Although the pressure reduction characteristic of this embodiment shown by the solid line in FIG. 2 is drawn in an uneven manner in relation to the A line and the B line for ease of understanding, it actually shows a smoother linear shape.

Although the embodiment of the present invention has been described above based on the drawings, the present invention can also be applied to other aspects.

For example, a valve plate 20 forming a valve seat
The pores may be formed at three or more locations at different distances from the center so that the area of the exhaust passage increases sequentially due to the elastic valve body 18 deforming as the pressure of the manifold 2 decreases. It's good.

Further, the shape of the pores 23 and 24 is not limited to round holes, but may also be square holes or slit-like holes, and the size (cross-sectional area) of the pores depends on the type of mansion 2 used, for example, in obese patients. Various changes can be made depending on whether the product is for adults or children.
In a small-capacity manchet 2 such as one for children, instead of making the diameters of the pores 23 and 24 extremely small, by connecting thin tubes or increasing the thickness of the valve plate 20, the diameters of the pores 23 and 24 are made very small. It is effective for machining to lengthen the exhaust path.

The above-mentioned embodiment is merely one embodiment of the present invention, and the present invention can be modified in various ways without departing from its spirit.

As detailed above, according to the exhaust valve of the present invention, compared to the conventional case where exhaust is exhausted through the opening of the slit formed in the elastic valve body,
As the pressure of the manifold becomes lower, the slit does not tend to close due to the elastic force, so that the pressure decrease rate of the manifold becomes constant and blood pressure can be measured with high accuracy.

Moreover, since the position and diameter of the exhaust hole are formed with high precision by machining, the above-mentioned pressure reducing characteristics can be obtained without variation among the individual exhaust valves.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of an embodiment of the present invention. FIG. 2 is a pressure reduction characteristic diagram of the manifold illustrating the effect of the embodiment shown in FIG. 2: Mansion seat, 4: Exhaust valve, 14: Valve chamber,
18: Elastic valve body, 20: Valve plate (valve seat), 23, 24: Pore (exhaust hole), 28: Communication hole, 30: High pressure chamber, 32: Atmospheric chamber.

Claims (1)

[Scope of Claim for Utility Model Registration] An exhaust valve for discharging air inside a manifold that compresses a part of the body during blood pressure measurement, comprising: a valve chamber communicating with the manifold; and a valve chamber provided on an inner wall surface of the valve chamber; a valve seat in which a pair of exhaust holes communicating with the atmosphere are formed in a central portion and a position a predetermined distance away from the valve seat; and a pair of exhaust holes provided in the valve chamber opposite to the valve seat to communicate the valve chamber with the manifold. The high-pressure chamber is divided into a high-pressure chamber that communicates with the atmosphere through the exhaust hole, and a communication hole that constantly communicates the high-pressure chamber with atmospheric pressure is provided at a position that does not face the exhaust hole, and the high-pressure chamber and the atmospheric chamber are separated. An elastic valve body that sequentially opens and closes the pair of exhaust holes by being pressed against the valve seat according to a pressure difference between the valve body and the valve seat.