JPH0675019B2 - Pressure measuring air mat and pressure measuring method and device using the air mat - Google Patents

Description

The present invention relates to a pressure measuring air mat for measuring a pressure applied to a body support device, etc., particularly a position where the maximum pressure is applied, and a pressure using this air mat. The present invention relates to a measuring method and an apparatus.

(Problems to be Solved by the Related Art and Invention) For example, in order to improve the body support characteristic of a body support device such as a car seat, a wheelchair seat, or a mattress, the distribution of the body contact pressure can be known. The best measure is whether or not the maximum value occurs everywhere.

Conventionally, as a method of measuring the distribution of the contact pressure of the body, for example, there is a method of arranging a large number of load cells vertically and horizontally, but in such a method, the apparatus becomes very expensive and large-scale. There is a problem that it will end up.

Another simple method for measuring the contact pressure of the body is to use a buccane equipped with electrodes corresponding to the upper and lower walls of the inside. The contact pressure is measured by the air pressure at the time when the upper and lower electrodes come into contact with each other. However, with this method, it is difficult to arrange a large number of enthusiasts in the vertical and horizontal directions and to perform measurements at the same time, and in the case of measuring at multiple positions, the positions of the entanglements must be changed one by one, which is troublesome and troublesome. If the area is large, only the average contact pressure can be measured for that area, and it is difficult to measure the contact pressure distribution over a wide range. Is also difficult to measure.

An object of the present invention is to solve the above problems and to make it possible to easily measure the position where the contact pressure of the body or other appropriate object with respect to the supporting device is maximum by a simple device. .

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a flat continuous air duct having an equal cross-sectional area in a plane shape, and an air inlet / outlet port at both ends thereof. The main point is the constructed air mat for pressure measurement. The continuous air duct may be formed in a flat shape such that it is connected in a corrugated shape from one end to the other end, or in a flat shape that is connected in a spiral shape from one end to the other end. . Further, in this air mat, upper and lower sheets may be adhered to each other, and a flexible continuous air duct having an equal cross-sectional area may be arranged in a plane, and air inlets and outlets may be formed at both ends thereof.

Next, the present invention introduces air from the air inlet to the above air mat by the air supply means, measures the change in air pressure and the elapsed time, and measures the elapsed time until the air pressure reaches the maximum from the load. The gist is a pressure measuring method for detecting a closed position of an air duct at the maximum contact pressure. The supplied air can be easily measured by keeping its flow rate constant.

Further, according to the present invention, a pressure measuring air mat in which a continuous air duct having a uniform cross-sectional area having flexibility is arranged in a plane, and air inlets and outlets are formed at both ends thereof, and an air inlet of the air mat. And an air supply means connected to the air mat via a communication pipe, a pressure measuring means for measuring an air pressure supplied to the air mat, and a time measuring means for measuring an elapsed time from the start of supplying air to the air mat. The main point is the pressure measuring device. The air supply means may be provided with a flow rate adjusting means for keeping the amount of air supplied to the air mat constant.

(Function) A continuous air pipe having a uniform cross-sectional area having flexibility is arranged in a plane, and air is supplied from the air inlet to the pressure measuring air mat having air inlets and outlets at both ends thereof by the air supply means. Is introduced, the supplied air is directed toward the air outlet through the continuous air pipe and is exhausted from here. At this time, if a part of the continuous air pipeline is blocked by the contact pressure of the load applied to it, the air is prevented from moving there, and the air pressure gradually increases. In this way, the air pressure gradually increases with the passage of time, and when a certain maximum pressure is reached, the blockage is opened and the movement of air is restarted.

However, as will be described later, from the start of the supply of air from the air inlet of the air mat to the maximum air pressure, that is, the time elapsed from the time when the blockage is opened and the movement of air is restarted, and from the air inlet of the air mat There is a correspondence relationship with the distance of the continuous air pipeline to the closed position. Therefore, if the elapsed time is measured, the distance of the continuous air pipeline from the air inlet to the closed position can be detected by the correspondence relationship. Yes, and from such a distance, the position on the plane of the air mat can be detected. If there are a plurality of closing positions, and especially if there is a closing position with a smaller contact pressure on the upstream side of the closing position with the maximum contact pressure, the maximum pressure is generated corresponding to the latter closing position. When the air that has passed through the closing position reaches the former closing position, the pressure starts to rise again, and thus the closing position of the maximum contact pressure is detected in the same manner as described above by the elapsed time until the last maximum pressure occurs. be able to.

Next, from the start of the supply of air from the air inlet of the air mat to the time when the air pressure becomes maximum, that is, the elapsed time from the time when the blockage is opened and the movement of air is restarted, and from the air inlet of the air matt to the blockage position. The corresponding relationship with the distance of the continuous air pipeline will be described.

First, in the air pump of the air supply means, the flow rate V
Generally, there is a linear relationship between (l / min) and the pressure P (Kgf / cm ² ) as shown in the following equation.

V (P) = C ₁ P + C ₂ (C ₁ <0, C ₂ > 0) (0 ≦ P ≦ − (C ₁ / C ₂ )) (1) Now, the cross-sectional area of the continuous air pipeline is S Assuming that blockage occurs at a position of a distance L from the air inlet, the following formula is established from Boyle-Charles' law.

RSL = nRT (2) RVdt = dnRT (3) (P + dp) SL = (n + dn) RT (4) Then, substituting equations (1) to (3) into equation (4). ,
Eliminating V, n, and dn yields equation (5), which can be solved to obtain equation (6).

However, C'is an integration constant.

Since the above equation (6) is complicated and difficult to handle, it is simplified by the following operation.

Assuming that the air supply means can supply a constant flow rate of air to the air pump, the supply flow rate can be expressed by the following equation.

V (P) = C (7) The following equation (8) is obtained from this equation (7) and the above equations (2) to (4), and the equation (8) is solved to obtain the equation (9). Can be obtained.

However, C'is an integration constant.

Expression (9) is the pressure P of the air, the distance L of the continuous air pipeline from the air inlet to the closed position, and the time when the maximum pressure is generated when the air is supplied at a constant flow rate by the air supply means. From the start of the supply of air from the air inlet of the air mat, that is, until the air pressure reaches the maximum, that is, until the blockage is opened and the movement of air is restarted. If the elapsed time t of is measured,
It can be seen that the distance L of the continuous air pipeline from the air inlet to the closed position can be detected from the correspondence expressed by the equation (9). The supply of air at a constant flow rate by the air supply means can be easily realized by providing an appropriate flow rate adjusting means between a general pump and an air mat. In addition, although it is relatively difficult to handle, the above-mentioned detection can be performed by using the above-mentioned formula (6) and using any air supply means.

(Embodiment) Next, an embodiment of the present invention will be described with reference to FIGS.

In FIG. 1 or FIG. 2, reference numeral 1 indicates an air mat. The air mat 1 has a flexible continuous air duct 2 having an equal cross-sectional area, which is arranged in a plane, and both ends thereof are arranged. The air inlets and outlets 3 and 4 are formed in the section. In the air mat 1 of the embodiment, the continuous air duct 2 is connected in a corrugated manner from one end to the other end to form a flat surface, but in addition to this, a planar shape in which it is spirally connected from the one end to the other end. It is appropriate to adopt a configuration in which continuous air pipelines having an equal cross-sectional area are arranged in a plane, such as the above-mentioned configuration. Further, this air mat 1 is constructed by applying an appropriate method in addition to laminating the upper and lower sheets 5 and 6 and arranging the flexible continuous air duct 2 having an equal cross section in a plane. be able to. It is preferable that the continuous air pipe 2 has the same diameter throughout its length. However, in the case of the structure having the folded-back portion 7 as shown in the drawing, for example, that portion is larger than at least the other diameter. If it does, it does not need to be equal. The material forming the continuous air conduit 2 is preferably one that has little elongation with respect to the internal air pressure and is flexible, for example, a highly polymerized PVC sheet, a urethane-PVC mixed sheet or a mesh. A urethane sheet or the like can be used.

Next, in FIG. 2, reference numeral 8 represents an air supply means. The air supply means 8 includes an air pump 9, a buffer tank 10, a pressure reducing valve 11, a throttle 12, a switching operation valve 13 and a pipe 14. The air supply means 8 has a pressure gauge.
15 and a flow meter 16 are provided. The switching control valve 13 is throttled
The supply air passing through 12 is switched to be supplied to the air mat 1 or open to the outside air. Further, the buffer tank 10 described above temporarily stores the compressed air from the air pump 9 and stabilizes the flow rate and the pressure.

In the above configuration, when air is introduced from the air inlet 3 into the air mat 11 via the pipe 14 by the air supply means 8,
The supplied air goes through the continuous air line 2 toward the air outlet 4 and is discharged from there. Simultaneously with the start of the supply of the air, the timing means (not shown) is operated to start the timing.
If the part 17 of the continuous air line 2 is closed due to the contact pressure of the load applied to it, the air is prevented from moving there, and the air pressure gradually increases. In this way, the air pressure gradually increases with the passage of time, and when a certain maximum pressure is reached, the blockage is opened and the movement of air is restarted. Then, the generation of the maximum pressure and the elapsed time until then are measured by the pressure gauge 15 and the time measuring means respectively, and the distance of the continuous air pipeline 2 from the air inlet 3 to the closed position 17 is detected by the elapsed time. And from that distance the position on the plane of the air mat can be detected.

FIG. 4 shows the air in the case where the weight of each weight is placed on the corresponding point of the continuous air pipeline located at each distance from the air inlet to close the corresponding point of the continuous air pipeline in the air mat. It represents the result of measuring the relationship between the distance of the continuous air pipe from the inlet to the closed position and the elapsed time from the start of supply to the maximum pressure. From this measurement result, measure the elapsed time. It can be seen that the distance of the continuous air line from the air inlet to the closed position and the corresponding position on the air mat can be measured.

(Effects of the Invention) As described above, the present invention provides a pressure measuring air mat by arranging a flexible continuous air duct having an equal cross-sectional area in a plane and forming air inlets and outlets at both ends thereof. Then, air is introduced into the pressure measuring air mat from the air inlet by the air supply means, the change in the air pressure and the elapsed time are measured, and the maximum time due to the load is calculated from the elapsed time until the air pressure reaches the maximum. Since the closed position of the air duct is detected by the contact pressure, it is possible to easily measure where the maximum contact pressure of the human body or the like supported on the upper side of this air mat occurs, and the device can be easily measured. There is an effect that it can be constructed at a very low cost as compared with a conventional load cell. Thus, the present invention is, for example, a vehicle seat,
There is an effect that the body support performance of a body support device such as a seat or a mattress of a wheelchair can be improved much better than in the conventional case that relies on human senses.

[Brief description of drawings]

All drawings correspond to the embodiment of the present invention. FIG. 1 is a plan view of an air mat for pressure measurement, and FIGS. 2 (a) and 2 (b) are respectively XX line and Y- line in FIG. FIG. 3 is a cross-sectional view taken along the line Y, FIG. 3 is an explanatory diagram of the entire system showing the measuring apparatus and method, and FIG. Reference numeral 1 ... Air matte, 2 ... Continuous air conduit, 3 ... Air inlet, 4 ... Air outlet, 5,6 ... Sheet, 7 ... Folding portion, 8 ... Air supply means, 9 ... Air pump, 10 ...
… Buffer tank, 11 …… Pressure reducing valve, 12 …… Throttle, 13…
… Switching valve, 14 …… Piping, 15 …… Pressure gauge, 16 ……
Flow meter, 17 ... closed position.

Claims (8)

[Claims] 1. An air mat for pressure measurement in which a continuous air duct having a uniform cross-sectional area having flexibility is arranged in a plane and air inlets and outlets are formed at both ends thereof. 2. An air mat for pressure measurement, wherein the continuous air duct according to claim 1 is formed in a planar shape in which one end is connected to the other end in a corrugated form. 3. An air mat for pressure measurement, wherein the continuous air pipeline according to claim 1 is constructed in a flat shape in which one end to the other end are connected in a spiral shape. 4. An air mat for pressure measurement in which upper and lower sheets are bonded to each other, and continuous flexible air ducts having an equal cross-sectional area are arranged in a plane shape, and air inlets and outlets are formed at both ends thereof. 5. A pressure measuring air mat having flexible continuous air ducts of equal cross-sectional area arranged in a plane and having air inlets and outlets at both ends thereof is provided by an air supply means. From the elapsed time until the air pressure reaches its maximum, the closed position of the air pipeline at the maximum contact pressure due to the load is detected. Measuring method 6. A pressure measuring air mat having flexible continuous air ducts of equal cross-section arranged in a plane, and air inlets and outlets at both ends of the air ducts, the air inlets being provided by air supply means. It introduces a constant flow rate of air from, measures the change in air pressure and elapsed time, and detects the closed position of the air pipeline at the maximum contact pressure due to the load from the elapsed time until the air pressure reaches its maximum. Pressure measurement method 7. A pressure-measuring air mat in which a flexible continuous air duct having an equal cross-sectional area is disposed in a plane shape, and air inlets and outlets are formed at both ends thereof, and an air inlet of the air mat. Pressure provided with air supply means connected via a communication pipe, pressure measuring means for measuring the supply air pressure to the air mat, and time measuring means for measuring the elapsed time from the start of supplying air to the air mat measuring device 8. A pressure measuring device, wherein the air supply means according to claim 7 is provided with a flow rate adjusting means for making the air supply amount to the air mat constant.