JPH0249636A - Constant pressure operation valve for hemomanometer - Google Patents

Abstract

PURPOSE:To reduce cost by eliminating power consumption and to dispense with an exclusive control circuit such as a solenoid valve by providing a valve body for preventing the communication of the first air flow passage with the second air flow passage when air pressure is predetermined value or more and allowing both flow passages to communicate with each other when air pressure is the predetermined value or less. CONSTITUTION:A valve 11 is provided to a diaphragm 8, which is movable in an up-and-down directions so as to increase and decrease the volume of an air chamber 4 at the almost center position thereof through a rod body 9 and a flange 13 having a flange hole 13A is formed to the almost center part of a housing 1 and the under surface of the valve 11 brings the upper surface of the flange 13 to a hermetically closed state and an open state. That is, in such a state that the valve 11 is not operated, the air entering from an inflow port 6 passes through the gap between the under surface of the valve 11 and the flange hole 13A and subsequently passes through the air chamber 4 to be capable of freely passing through an outflow port. When cuff pressure reaches 20mmHg or more, a constant pressure operation valve 20 for a hemomanometer becomes a closed state not permitting the passage of air and, when cuff pressure becomes 20 mmHg, said valve 20 becomes an open state permitting the passage of air.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a constant pressure operating valve for a blood pressure monitor used in automatic electronic blood pressure monitors and the like.

[Prior Art] Conventionally, automatic electronic blood pressure monitors with a built-in electric pump have a low cuff pressure that is not directly involved in blood pressure measurement. For example, when the cuff pressure is 20 mmt (g or less), the cuff pressure is increased. In order to efficiently lower the blood pressure and lower the pressure within a short time, air is directly introduced into and out of the cuff from an electric pump or a release valve.

On the other hand, a rectifier circuit, which is interposed in the pneumatic system from the electric pump to the cuff and consists of air resistance elements such as filters, is provided to remove the pulsating flow of the electric pump.
The cuff pressure during blood pressure measurement is made to change at a constant rate that does not include pulsations. In the above configuration,
When the cuff pressure, which is not directly involved in blood pressure measurement, is low, air is sent directly from the electric pump mentioned above to the cuff, but when the pressure reaches a predetermined level, the air supplied from the electric pump is passed through a rectifier circuit and pumped into the cuff. In order to supply rectified flow that does not include pulsation, an electromagnetic solenoid valve or the like that operates according to the result of a pressure detection signal is used.

[Problems to be Solved by the Invention] However, the electromagnetic Threid valve used in this manner consumes a large amount of power, and in particular, when the electromagnetic Threid valve is used in a portable blood pressure monitor powered by a battery, the power source is There is a problem in that the load on the battery increases and the battery life is shortened, making it impossible to use it for a long time.

Further, it is difficult to suppress the increase in cost due to the electromagnetic thraid valve and associated components, and a dedicated control circuit for the electromagnetic trailed valve is required.

Therefore, the present invention has been made in view of the above-mentioned problems, and its purpose is to reduce costs without consuming power, and to eliminate the need for a dedicated control circuit such as an electromagnetic treid valve. An object of the present invention is to provide a constant pressure operating valve for a blood pressure monitor.

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the objectives, the constant pressure valve for a blood pressure monitor of the present invention has the following configuration: a housing having an air chamber therein; , a first air flow path and a second air flow path that are open at one end in the air chamber and communicated with each other via the air chamber, and partitioned between the air chamber and a side open to atmospheric pressure. is disposed in the housing, when the air chamber has a predetermined pressure or higher, communication between the first air flow path and the second air flow path is blocked, and when the air chamber has a pressure lower than a predetermined pressure, the first air flow path is prevented from communicating with the second air flow path. It is provided with a valve body that communicates the flow path with the second air flow path.

Moreover, it is preferable that the valve body is made of an elastic body, with the diaphragm and the valve integrated.

Furthermore, it is effective to provide a metal diaphragm on the side of the diaphragm that is exposed to atmospheric pressure.

Further, preferably, a reinforcing leaf spring is provided on the side of the diaphragm that is exposed to atmospheric pressure.

Furthermore, preferably, a deformation prevention member for preventing excessive deformation of the diaphragm is provided on the side exposed to atmospheric pressure.

[Function] A housing having an air chamber therein, and a first air flow path and a second air flow path having one end opened in the air chamber and communicating with each other via the air chamber.

and disposed in the housing to partition the air chamber and a side open to atmospheric pressure, and when the air chamber is at a predetermined pressure or higher, the first air flow path and the second air flow path are connected to each other. On the other hand, when the pressure in the air chamber is lower than a predetermined pressure, the valve body acts to maintain communication between the first air flow path and the second air flow path.

Further, the valve body is formed of a rubber-like body in which the diaphragm and the valve are integrated, and act as one unit.

Additionally, a metal diaphragm is installed on the side of the diaphragm that is exposed to atmospheric pressure to withstand high pressure.

Additionally, a reinforcing leaf spring is attached to the side of the diaphragm that is exposed to atmospheric pressure to withstand high pressure.

Further, a deformation prevention member for preventing excessive deformation of the diaphragm is provided on the side exposed to atmospheric pressure, thereby preventing the diaphragm from being excessively deformed.

[Example] A preferred example to which the constant pressure valve device for a blood pressure monitor of the present invention is applied will be described with reference to the drawings.

FIG. 1(a) is a partial cross-sectional view showing a central part of a constant pressure operating valve for a blood pressure monitor according to an embodiment, and FIG. 1(b) is a partial cross-sectional view showing a constant pressure operating valve for a blood pressure monitor according to an embodiment. It is a bottom view.

In FIG. 1(a), a housing 1 is formed in a cylindrical shape, and an air inlet 6 and an air outlet 5 are connected to the air chamber 4 in the housing 1 on the upper surface of the housing 1, as shown in the figure. They are integrally provided so that they can communicate with each other. Each of the inflow port 6 and the outflow port 5 has a hollow protrusion shape so that a soft plastic tube for piping, which will be described later, can be easily connected. cuff is connected.

Further, a valve 11 is provided via a rod 9 at approximately the center of the diaphragm 8, which is formed of a rubber-like material and is movable in the vertical direction in the figure so as to increase or decrease the volume of the air chamber 4.
A gate body 12 is provided on the upper part of the valve 11.
are provided as shown.

On the other hand, a flange 13 having a flange hole 13A is formed approximately at the center of the housing 1, and the lower surface of the valve 11 can be in a state where the upper surface of the flange 13 is sealed, or in an open state as shown in the figure. It is supposed to be done. In other words, as shown in the figure, when the valve 11 is not in operation, air entering from the inlet 6 flows between the lower surface of the valve 11 and the flange hole 13.
After passing through the space A, it passes through the air chamber 4 and can freely pass to the outlet 5.

Here, the inflow port 6 and the outflow port 5 are named like this for convenience, but considering that the cuff used in the electronic blood pressure monitor repeatedly raises and lowers the blood pressure,
The direction of air flow is opposite when the pressure is increased and when the pressure is decreased, and the name must be reversed accordingly, but even if the air flow is reversed, it does not interfere with the operation of this device, so the inlet port 6 and the outlet 5 will be representatively explained.

Here, the surface on which the lower surface of the valve 11 and the opening edge of the flange hole 13A come into contact is made smooth, and even with a slight acting force, the valve 11 and the opening edge of the flange hole 13A can be reliably brought into contact with each other. An annular protrusion 14 is provided at the opening edge of the flange hole 13A for abutting and sealing.

Furthermore, the annular gap formed between the inner diameter of the flange hole 13A and the outer diameter of the shaft body 9 that connects the valve 11 and the diaphragm 8 is an obstacle to obtaining the required air flow rate. Sufficient dimensions are determined from the calculations described below so that this does not occur.

On the other hand, in order to keep the diaphragm 8 in an airtight state, the lower edge of the housing 1 has a smooth surface that comes into contact with the diaphragm 8, and when assembled with the diaphragm 8 sandwiched between the back-up body 3. This is to prevent air from leaking from the contact surface with the diaphragm 8.

Furthermore, the outer peripheral edge of the housing 1 has a fitting tab I so that when it is assembled with the back-up body 3, it can be easily assembled into the state shown in the figure without the need for special separate parts.
A is provided all around the circumference.

As mentioned above, the diaphragm 8 is made of rubber or soft plastic and is integrally molded with the valve 11. It is even better if the projections 9A are provided around the entire circumference so that an airtight seal is formed.

Furthermore, the elongated gate shaft 12 attached to the tip of the valve 11 is the remainder of the gate for injecting rubber raw materials etc. when the valve 11 and diaphragm 8 are integrally molded. , the valve 11, which has an outer diameter larger than the inner diameter of the flange hole 13A, must be passed through the flange hole 13A, but when the gate shaft 12 is pulled upward from the inlet side, the valve 11 is inserted into the flange hole 13A.
1 is forcibly inserted, making the assembly work easier.

On the other hand, the buffer body 3 is assembled by sandwiching the diaphragm 8 with the housing 1 as described above, and also pushes the diaphragm 8 against the housing 1 to seal the air chamber 4. 8 to the housing 1 in an airtight manner. Therefore, the surface of the back-up body 3 that contacts the diaphragm 8 is formed to have the same inner diameter as the housing 1. In order to keep the pressure applied to the diaphragm 8 of the back-up body 3 equal to atmospheric pressure, an atmospheric pressure opening hole 15 is provided.
will be provided.

Further, when excessive pressure is applied to the diaphragm 8, an excessive force is applied to the valve 11, and in order to prevent the valve 11 from falling out of the flange hole 13A, a back-up is installed when the diaphragm 8 expands beyond a certain level. The diaphragm 8 abuts against the inner surface of the body 3 to prevent the diaphragm 8 from expanding excessively, thereby preventing damage to the valve 11.

Further, the fitting claws 3A are arranged at eight locations on the outer periphery of the back-up body 3 at equal intervals in order to fit with the fitting claws IA on the outer periphery of the housing 1. These mating claws 3
A is dimensioned so that the projections 9A on the outer periphery of the diaphragm are all crushed and the outer peripheries of the housing 1 and back-up body 3 are in contact with the surface of the diaphragm 8 over the entire circumference, so that they fit together. .

FIG. 2 is a partially cutaway view of the central part of the constant pressure valve for a blood pressure monitor described above, showing the diaphragm 8 in a bent state. On the other hand, the amount of deflection of a diaphragm is generally expressed mathematically as a disk diaphragm with a fixed periphery, and is also described in machine handbooks and the like.

Here, the desired pressure is P, the gap between the valve 11 and the flange hole 13A is d, and the thickness of the diaphragm 8 is t.
If the radius of is R and the Young's modulus of diaphragm 8 is E, then
The relationship is as follows.

3 (m"-1)PR' d = 16Em"t' However, 1/m is Poisson's ratio, and in rubber it is approximately 0.
5, so m=2. Also, Young's modulus is 24
If we set a valve that operates at 20 mmHg using a rubber of
, 026 kg/cm", so if the radius of the diaphragm is 1 cm and the thickness is 0.1 cm, then 3
(2"-1)xo, 026xl'd = 16x24x2" x (0,1)'0, 234 = =0. 152 (cm)1,
536, it is sufficient to set the dimensions of each part so that the gap between the valve and the flange is 1.52 mm.

Here, rubber has a large variation in Young's modulus depending on the temperature at which it is used, and also has viscoelastic properties, and the accuracy of the operating pressure varies greatly due to the influence of temperature and the like. Furthermore, when designing valves that operate at high pressures, the diaphragm becomes very thick because the Young's modulus of rubber is very small.

FIG. 3 is a partially cut away view of the central part of a constant pressure operating valve for a blood pressure monitor showing another embodiment, in which a metal diaphragm 10 is placed over the above-mentioned rubber diaphragm 8. It shows what happened. By using the metal diaphragm 10 in this way, the rubber diaphragm 8
can be used to construct valves that operate at high pressures. For example, when the metal diaphragm 10 is made of stainless steel, the Young's modulus is as large as 2 x 10 'kg/cm, so the operating pressure of the valve should be determined based on the physical properties of the metal diaphragm rather than the elasticity of the rubber. Can be done.

Furthermore, if very high pressure is not required, a part of the metal diaphragm may be cut out.

FIGS. 4(a), 4(b), and 4(C) are plan views showing examples of the structure of the metal diaphragm.

FIG. 4(a) shows a metal diaphragm lO formed into an annular shape.
In FIG. 4(b), the radial leaf spring 10B is
In the diagram (C), radial leaf springs 1OB are shown. Since the metal diaphragm or plate spring formed in this manner is subjected to spring force from below near the center where it is connected to the valve, the operating pressure is no longer determined solely by the physical properties of the rubber.

Next, FIG. 5 is a schematic view showing a pneumatic system in which the constant pressure operating valve for a blood pressure monitor described above is used, and FIG. 6 is a plan view showing an actual piping diagram.

In both figures, the above-described constant pressure valve 20 for a blood pressure monitor is connected in parallel with a filter device 32 and piped to an electric pump 30, while an electromagnetically driven pressure valve is connected to the outlet 5 of the constant pressure valve 20 for a blood pressure monitor. A rapid evacuation valve 34 is shown with a constant pressure reducing valve 36 and a cuff 38 plumbed to the filter device 32.

In an automatic blood pressure monitor arranged in this way, the cuff 38
When the cuff pressure is 20 mmHg or less, air is directly flowed into the cuff 38 from the electric pump 3o in order to efficiently increase and decrease the cuff pressure within a short time. When the cuff pressure is 20 mmHg or less, the blood pressure monitor constant pressure valve 20 is in an open state allowing air to pass through, so that air directly flows into the cuff 38 from the electric pump 30.

On the other hand, when the cuff pressure becomes 20 mmHg or more, the constant pressure valve 20 for the blood pressure monitor becomes closed to prevent air from passing through.
Interposed in the pneumatic system between the electric pump 30 and the cuff,
A rectifying circuit consisting of an air resistance element such as a filter allows air to pass through a filter device 32 provided to remove pulsating flow from the electric pump, so that the cuff pressure during blood pressure measurement remains at a constant rate without pulsating. A supply of air will be made to the cuff 38.

In addition, when measuring blood pressure during the process of decreasing cuff pressure, the constant speed reducing valve 36 is opened and the cuff pressure is lowered until the cuff pressure falls below 20 mmHg, as in the case of increasing cuff pressure. The blood pressure monitor constant pressure valve 20 is in an open state allowing air to pass therethrough, and as a result, the air within the cuff 38 is exhausted.

In other words, a conventional valve device including an electromagnetic solenoid as a driving means is no longer necessary.

[Effects of the Invention] Since the constant-pressure operating valve for a blood pressure monitor of the present invention is configured as explained above, it consumes no electricity, reduces costs, and eliminates the need for a dedicated control circuit such as an electromagnetic treid valve. A constant pressure valve for a blood pressure monitor will be provided.

Further, the valve body is formed of a rubber-like body by integrating a diaphragm and a valve.

Furthermore, by providing a metal diaphragm on the side of the diaphragm that is open to atmospheric pressure, the device can be applied to high pressures.

Furthermore, by providing a reinforcing leaf spring on the side of the diaphragm that is open to atmospheric pressure, it is possible to apply the device to high pressures.

In addition, a deformation prevention member for preventing excessive deformation of the diaphragm is provided on the side exposed to atmospheric pressure, thereby preventing the diaphragm from being excessively deformed and thereby preventing damage or falling off.

[Brief explanation of the drawing]

FIG. 1(a) is a partial cross-sectional view showing a central part of a constant pressure operating valve for a blood pressure monitor according to an embodiment, and FIG. 1(b) is a partial cross-sectional view showing a constant pressure operating valve for a blood pressure monitor according to an embodiment. FIG. 2 is a partially cutaway view of the center part of the constant pressure valve for blood pressure monitor shown in FIG. 1, and FIG. Partial cross-sectional view showing the central part partially broken, Fig. 4(a), (
b) and (C) are plan views showing an example of the configuration of a metal diaphragm, Fig. 5 is a schematic diagram showing the pneumatic system of an automatic electronic blood pressure type, and Fig. 6 is a plan view showing an actual piping diagram. . In the figure, ■...Housing, 3...Backup body,
4... Air chamber, 5... Inlet, 6... Outlet, 8
...Diaphragm, 10...Metal diaphragm, 1
DESCRIPTION OF SYMBOLS 1... Valve, 13... Flange, 13A... Flange hole, 15... Open hole, 10... Metal diaphragm. Porridge diagram diagram diagram

Claims (5)

[Claims] (1) A housing having an air chamber therein, a first air flow path and a second air flow path that are opened at one end in the air chamber and communicated with each other via the air chamber, and are connected to the air chamber in a large manner. The air chamber is disposed in the housing so as to partition a side that is open to atmospheric pressure, and the air chamber prevents communication between the first air flow path and the second air flow path when the pressure exceeds a predetermined pressure.
A constant pressure operating valve for a blood pressure monitor, characterized in that the air chamber includes a valve body that communicates with the first air flow path and the second air flow path when the pressure is below a predetermined pressure. (2) The constant pressure operating valve for a blood pressure monitor according to claim 1, wherein the valve body is formed of an elastic body by integrating the diaphragm and the valve. (3) The constant pressure valve for a blood pressure monitor according to claim 2, further comprising a metal diaphragm on the side of the diaphragm that is open to atmospheric pressure. (4) The constant pressure operated valve for a blood pressure monitor according to claim 2, further comprising a plate spring for reinforcement on the side of the diaphragm that is open to atmospheric pressure. (5) The constant pressure operating valve for a blood pressure monitor according to claim 1, further comprising a deformation preventing member for preventing excessive deformation of the diaphragm on the side that is open to atmospheric pressure.