WO2013039153A1

WO2013039153A1 - Respiratory protective tool provided with electric fan

Info

Publication number: WO2013039153A1
Application number: PCT/JP2012/073482
Authority: WO
Inventors: 幸典三崎; 宏行藤井; 智博大西; 聡一郎田井
Original assignee: 独立行政法人国立高等専門学校機構
Priority date: 2011-09-15
Filing date: 2012-09-13
Publication date: 2013-03-21
Also published as: JP2013075157A

Abstract

[Problem] To provide a respiratory protective tool provided with an electric fan capable of resolving the problems where detection accuracy declines over time and where degradation of an exhalation valve over time causes a decline in detection accuracy. [Solution] A respiratory protective tool provided with an electric fan, the tool comprising: a surface body for covering a wearer's nostrils and mouth; an inlet to which a filter is provided; an electric fan for sending outer breath into the surface body, by way of the inlet; an outlet; a pressure measurement unit; and a control unit for controlling the rotational speed of the electric fan; wherein the tool is characterized in that the pressure measurement unit is configured to comprise a film member for deforming in accordance with a change of pressure inside the surface body, and a respiration sensor for deforming so as to follow the movement of the film member, and the control unit controls the electric fan in accordance with an output signal from the pressure measurement unit.

Description

Breathing protection with electric fan

The present invention relates to a respirator with a full-surface or half-surface electric fan used for the purpose of dust prevention, poisoning, and the like, and more specifically, for example, controls the operation of the electric fan according to a pressure change in the face. The present invention relates to a respiratory protective device with an electric fan.

In an environment where dust that is harmful to the human body is present, the user wears a dust mask and breathes air with dust removed by a filter. The filter usually has a problem that the greater the purification effect, the greater the ventilation resistance. However, there is a problem that the filter feels stuffy for the ventilation resistance of the filter. In addition, when the pressure inside the mask surface becomes negative compared with the environmental pressure due to ventilation resistance, there is a problem that dust enters from the gap between the mask and the face. Therefore, a dust mask having a high resistance filter is provided with a blower (electric fan) that assists in breathing.

However, a blower mask device that constantly supplies a certain amount of air without being linked to the breathing of the wearer is likely to wear out the filter, the pressure in the mask increases, and the resistance during exhaust (exhalation) increases, power consumption However, there were many problems such as short drive time. Accordingly, a breathing-linked type blower mask device has been proposed in which the blower air volume is increased during intake while the wearer's breathing is increased, while the blower air volume is decreased during exhaust (see, for example, Patent Document 1). ). This blower mask device detects the movement of the exhaust valve or intake valve with an optical sensor, controls the blower according to the signal from the sensor, stops and decelerates the blower during exhaust, and exhausts the filter, exhaust resistance and power consumption I try to suppress it.
However, in the configuration employing the optical sensor, when the light receiving element of the sensor receives external light such as sunlight, there is a problem that the movement of the exhaust valve cannot be accurately detected and the control of the blower becomes inaccurate. . To block external light from the optical sensor, for example, lengthen the exhaust valve cover to keep the sensor away from the exhaust port at the tip, and further narrow the exhaust port so that external light does not reach the sensor. However, if this is done, the mask becomes bulky, the opening area of the exhaust port becomes narrower, and the exhaust resistance increases, which causes problems such as poor wearing feeling.

Patent Document 2 proposes a breathing interlock type blower mask in which a non-optical sensor is provided on an exhaust valve. Here, examples of the non-optical sensor include a temperature sensor, a humidity sensor, a carbon dioxide gas sensor, and an oxygen gas sensor. However, when a sensor is installed in the exhaust flow path, there is a problem that the sensor is contaminated by fine dust and moisture contained in the exhaust, and the detection accuracy is likely to deteriorate with time. Further, the temperature sensor has a problem that it does not function in an environment where the temperature of the outside air is about the same as the body temperature. The humidity sensor also has a problem that it does not function in an environment where the humidity of the outside air is about the same as that of a breath exhaled by a human. Gas sensors are expensive and have a problem that their circuit configuration is complicated and miniaturization is difficult.

Patent Document 3 proposes a respiratory monitoring device having a diaphragm covering an opening formed in a face piece, a magnet attached to the diaphragm, and a Hall element attached to the face piece facing the magnet. Since the Hall element is a magnetic sensor, even if fine dust or water droplets contained in the air in the face body are attached, the detection accuracy is unlikely to be lowered compared to the optical sensor.

Japanese Patent No. 3726886 JP 2008-289600 A JP 2009-136521 A

Since the apparatus of Patent Document 1 uses an optical sensor, there is a problem such as malfunction due to external light. In addition, the devices of

Patent Documents

1 and 2 have a problem that the sensor is contaminated by fine dust and moisture contained in the exhaust gas, and the detection accuracy is likely to deteriorate with time, and the detection accuracy is deteriorated due to deterioration of the exhaust valve with time.
The device of Patent Document 3 has a problem of deterioration in accuracy over time, if not as much as that of an optical sensor, because the sensor unit is exposed to air in the face. In addition, due to the structure using the diaphragm and the Hall element, there are restrictions on the reduction in size and weight of the breathing detection means.

An object of the present invention is to provide a respirator with an electric fan that can solve the above-mentioned problems.

The first invention includes a face covering the nostril and mouth of the wearer, an air inlet provided with a filter, an electric fan that sends outside air into the face through the air inlet, an air outlet, a pressure measuring unit, A respiratory protective device with an electric fan comprising a control unit for controlling the number of rotations of the electric fan, wherein the pressure measuring unit deforms in response to a pressure change in the body and follows the movement of the film member The respiratory protective device with an electric fan is characterized in that the control unit controls the electric fan according to an output signal from the pressure measuring unit.
According to a second invention, in the first invention, the respiration sensor is constituted by a strain gauge.
According to a third invention, in the second invention, the strain gauge is composed of an even number of sheets and has a function of canceling a voltage generated by heat.
In a fourth aspect based on the first aspect, the respiration sensor is constituted by a piezoelectric sensor.
According to a fifth invention, in the fourth invention, the piezoelectric sensor is formed of a PVDF film.
A sixth invention is the fourth or fifth invention, wherein the respiration sensor has substantially the same shape and substantially the same element capacitance as the first element (A) and the first element (A). The first element (A) and the second element (B) disposed opposite to each other, and having a function of canceling a voltage generated by heat applied to the first and second elements. Features.
A seventh invention is characterized in that, in any one of the first to sixth inventions, the membrane member is fixed to the face body via a fixing material made of a vibration absorbing material.
An eighth invention is characterized in that, in any one of the first to seventh inventions, the respiration sensor is arranged outside the membrane member.
A ninth invention is characterized in that, in any one of the first to eighth inventions, the respiration sensor is configured in an elongated shape having one end fixed to the membrane member and the other end fixed to the fixing member. To do.
A 910th invention is characterized in that, in any one of the first to ninth inventions, the control unit reduces the rotational speed of the electric fan during exhausting compared to during intake.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the respirator with a respiration following type electric fan provided with the new respiration detection means called a respiration sensor. Since this new respiration detection means is a respiration sensor that deforms following the movement of the membrane member, the pressure measuring unit can be made smaller and lighter.
Furthermore, in the configuration in which the respiration sensor is disposed outside the membrane member, since the respiration sensor is not exposed to the air in the face body, there is an effect that it is difficult for the detection accuracy to decrease with time.

It is a perspective view which shows the aspect of the dust mask of this invention. It is a figure which shows the pressure change in the face body in a dust mask, (a) when there is no electric fan, (b) When the electric fan which operates continuously is provided, (c) provides the electric fan which operates only at the time of intake FIG. It is a figure which shows the state of the pressure measurement part by respiration, (a) is the state at the time of exhaust, (b) is the state at the time of inhalation. (A) is a figure which shows the state of the electric charge produced when a temperature change is simultaneously given to the surface of piezoelectric film A and the back surface of piezoelectric film B, (a) is piezoelectric film A, B of the same arrangement | positioning as (a). It is a figure which shows the state of the electric charge which arises when stress is simultaneously given from the same direction. It is a figure which shows the circuit structure which cancels the output which arises with the heat applied from the same direction. In the circuit of FIG. 5, (a) a diagram illustrating a charged state when a temperature is applied from the same direction, and (a) a diagram illustrating a charged state when a stress is applied from the same direction. It is a figure which shows the measurement result of the pressure change in the body by respiration, (a) is a case where an electric fan is turned OFF, (b) is a case where an electric fan is turned ON. It is a figure which shows the change of the pressure in a mask by respiration with and without the control of an electric fan. 6 is a configuration diagram of laminated structure sheets A, B, and C according to Example 2. FIG. 6 is a cross-sectional view of laminated structure sheets A, B, and C according to Example 2. FIG. It is a figure which shows the measurement result of the pressure change in the face body which arises by a person's breathing in the state which turned on an electric fan, (i) is the case of the comparative example 1, (ii) is the case of the sheet | seat A which concerns on Example 2. , (Iii) is the case of the sheet B according to the second embodiment, and (iii) is the case of the sheet C according to the second embodiment. It is a figure which shows the measurement result of the pressure change in the face body which arises by a person's respiration in the state which turned off the electric fan, (i) is the case of the comparative example 1, (ii) is the case of the sheet | seat A which concerns on Example 2. , (Iii) is the case of the sheet B according to the second embodiment, and (iii) is the case of the sheet C according to the second embodiment. It is a figure which shows the state of the pressure measurement part at the time of using a strain gauge for a respiration sensor, (a) is the state at the time of exhaust, (b) is the state at the time of inhalation. It is a block diagram of a strain gauge. It is a circuit diagram by one strain gauge. It is a circuit diagram by two strain gauges. It is a circuit diagram by four strain gauges. It is a circuit diagram by two strain gauges which have a temperature cancellation function.

DETAILED DESCRIPTION A mode for carrying out the present invention will be described using an example of a dust mask with an electric fan.

"Constitution"
As shown in FIG. 1, the dust mask 1 of the present invention includes a face piece 2, an electric fan unit 3 provided at the center of the front face of the face piece 2, and a pair of exhausts provided facing the side face of the face piece 2. The mouth 4, the pressure measurement unit 5, and the control unit 6 (not shown) are main components.

The face piece 2 is formed in a size capable of covering the nostril and mouth of the face of the mask wearer. The electric fan unit 3 includes a blade member and a motor, a detachable filter (filter material) provided detachably, and an intake check valve that closes during exhaust and opens during intake. The exhaust port 4 includes an exhaust check valve that opens during exhaust and closes during intake. The number and positions of the exhaust ports 4 are not limited to those shown in the figure, and for example, one may be provided above or below the electric fan unit 3.

The pressure measurement unit 5 according to the present embodiment includes a membrane member 51, a piezoelectric sensor 52 that constitutes a respiration sensor, an air passage 53 that communicates with the internal space of the face piece 2, and fixing members 54 and 55 (FIG. 3). reference). The membrane member 51 is a sheet made of a flexible material, for example, a silicon rubber sheet, which is deformed by a pressure change in the face due to breathing, and is stretched so as to expand outward during exhaust and contract inward during intake. Has been. The fixing members 54 and 55 that support the membrane member 51 are made of a vibration absorbing material. For example, a soft material including an elastic body such as rubber or a cell (may be a liquid cell) such as polystyrene foam is used. Can do.
The piezoelectric sensor 52 is, for example, a flexible sheet-like member, and has one end fixed to the film member 51 and the other end fixed to the fixing member 55 so as to follow the movement of the film member 51. It is fixed to. The piezoelectric sensor 52 is preferably disposed outside the membrane member 51 so as not to be affected by heat, moisture, dust, and the like due to the wearer's breathing. In order to prevent dust or the like outside the face from adhering to the piezoelectric sensor 52, it is preferable to cover the piezoelectric sensor 52 with a protective member (cover) in which ventilation is ensured.
The position of the pressure measuring unit 5 is not limited to the illustrated one, and can be installed at any location, but it is preferably installed at a location where the wind from the wearer's breathing is not directly applied. A plurality of pressure measuring units 5 may be provided.

The piezoelectric sensor 52 may be one that exhibits a piezo effect, such as a piezoelectric ceramic or piezoelectric ceramic thin film made of PVDF (Polyvinylidene fluoride), barium titanate, lead zirconate titanate (PZT), or the like. Is done. In addition, fine powders of inorganic piezoelectric materials such as Pb (Zr · Ti) O ₃ , PbTiO ₃ , (Pb, La) (ZR, Ti) O ₃ are put into polymer materials such as thermoplastic resins and thermosetting resins. A dispersed one may be used. Preferably, a PVDF film that is lightweight, flexible, and has good workability is used. PVDF also has the characteristics that the response band is extremely wide and it is difficult to have a specific resonance frequency. The PVDF film can be used as a sandwich structure in which the film is sandwiched between aluminum foil electrodes, and lead wires are bonded to the electrodes with a conductive adhesive or the like.

The control unit 6 grasps the wearer's breathing state based on the voltage signal generated by the piezoelectric sensor 52 according to the strain caused by the stress applied by the wearer's breathing, and controls the rotational speed of the motor that drives the electric fan. Do. If there is no breathing for a certain time, the electric fan may be stopped. The control unit 6 (not shown) may be provided on the dust mask 1 itself, but is preferably provided separately from the dust mask 1 from the viewpoint of weight. For example, it is a box-like body in which a computer connected to the cable 61 is housed, and is configured to be attached to the wearer's waist.

<Operation>
Fig.2 (a) is a figure which shows the pressure change in the face body in the dust mask without an electric fan. The dust mask tends to have a negative pressure in the mask face compared to the environmental pressure due to the ventilation resistance of the filter. However, if there is a gap between the mask and the face, there is a risk that dust may enter the face. Therefore, it is preferable to provide an electric fan so that the in-plane pressure is always positive as compared with the environmental pressure. FIG.2 (b) is a figure which shows the pressure change in a face body at the time of providing the electric fan which operates continuously. Thus, by providing an electric fan (no control), the in-plane pressure can always be positive compared with the environmental pressure without changing the pressure difference between expiration and inspiration.

However, as described above, if a constant amount of air is constantly supplied, there are problems such as an increase in the pressure in the mask and an increase in resistance during exhaust (during expiration), a large amount of power consumption, and a short drive time. Therefore, by controlling the rotational speed of the electric fan, the exhaust resistance is reduced by reducing the pressure in the face within a range higher than the environmental pressure. Specifically, power is supplied so that the motor normally operates during intake, and power is supplied so that the motor stops or the number of revolutions decreases during exhaust, thereby reducing the exhaust resistance (FIG. 2C). reference).

FIG. 3A is a diagram illustrating a state of the pressure measurement unit 5 during exhaust (when exhaling). The membrane member 51 fixed by the fixing member 54 is in a state of being expanded and deformed outward (on the side opposite to the wearer) in response to an increase in the pressure of the air passage 53. The piezoelectric sensor 52 has one end fixed to the fixing member 55 and the other end fixed to the film member 51. In this state, the piezoelectric sensor 52 is slightly warped outward.
FIG. 3B is a diagram illustrating the state of the pressure measurement unit 5 during inspiration (when inhaling). The membrane member 51 is in a state of being depressed and deformed by being pulled inward (wearer side) after the pressure of the air passage 53 is lowered. In this state, the piezoelectric sensor 52 is greatly curved inward. Since the piezoelectric sensor 52 only needs to be distorted by the intake air, the film member 51 does not necessarily have to be deformed in a concave shape, and may have a horizontal or gentle arch shape.
As described above, the piezoelectric sensor 52 is distorted outward and inward due to the breathing of the wearer, so that an electric charge corresponding to the distortion is induced. Contrary to FIG. 3, the piezoelectric sensor 52 may be configured to be greatly warped outward during exhaust and bend slightly horizontally or inward during intake. In addition, when detecting that the in-plane pressure has become negative due to clogging of the filter or the like due to a change in the output of the piezoelectric sensor 52, control is performed to increase the rotational speed of the electric fan as compared with the normal time. Also good.

《Temperature cancel function》
The piezoelectric sensor 52 has a problem that an extra electrical output is generated due to a temperature change, which becomes a noise output. Therefore, a temperature canceling function may be provided by arranging a pair of piezoelectric sensors 52 side by side. The temperature canceling function utilizes a phenomenon in which when the piezoelectric film is heated, the front side is positively charged and the back side is negatively charged.

FIG. 4A is a diagram illustrating a state of electric charges generated when a temperature change is simultaneously applied to the surface of the piezoelectric film A and the back surface of the piezoelectric film B. FIG. 4A, when heat is applied to the juxtaposed piezoelectric films A and B from the same direction, it can be confirmed that each front surface side is positively charged and each back surface side is negatively charged.
FIG. 4A is a diagram showing a state of electric charges generated when stress is simultaneously applied from the same direction to the piezoelectric films A and B having the same arrangement as FIG. 4A, when stress is applied to the piezoelectric films A and B, the surface on which the stress is applied is positively charged regardless of whether the piezoelectric film is from the front side or the back side. It can be confirmed that the opposite surface is negatively charged.

FIG. 5 is a diagram showing a circuit configuration for canceling an output generated by heat applied from the same direction. In the circuit of FIG. 5, FIG. 6A shows a charged state when a temperature change occurs, and FIG. 6A shows a charged state when a stress is applied. As shown in FIG. 6A, the electric charge generated by the temperature change is not output because it moves between the piezoelectric elements A and B. On the other hand, as shown in FIG. 6A, the output of the electric charges generated by the stress is detected by a measuring device (not shown) connected to the conductive wire. In this way, by placing the pair of piezoelectric sensors 52 whose upper surfaces are opposite to each other on the pressure measuring unit 5, it is possible to cancel the temperature change and detect only the strain given by respiration.

《Strain gauge》
The respiration sensor may be constituted by a strain gauge 56 instead of the piezoelectric sensor 52. The configuration in this case is as shown in FIG.
The strain gauge is a mechanical sensor for measuring strain, and is used for, for example, stress measurement and a load gauge. For example, as shown in FIG. 14, an etching technique is used to form a pattern having a grid portion that is a linear portion aligned in parallel and an end tab portion that is a folded portion of the grid portion on a metal foil adhered on a resin film that is a base material. Formed and configured.
When a strain gauge is used alone, the change in resistance due to strain is extremely small. Therefore, the strain gauge is assembled in the Wheatstone bridge circuit shown in FIG. 15, and the change in resistance is converted into a change in voltage (E: bridge voltage, E _0). : Output voltage). In this circuit, an output voltage proportional to the resistance change can be obtained, and an output voltage proportional to the distortion can be obtained. This minute voltage can be expanded by an amplifier and obtained as an analog output or displayed as a digital value to measure distortion.

Further, since the strain gauge is very flexible, a respiration sensor can be configured by a plurality of strain gauges. For example, the respiration sensor may be configured by two strain gauges (see FIG. 16) or four strain gauges (see FIG. 17). If a respiration sensor is constituted by a plurality of strain gauges, a large output can be obtained and a change in temperature can be canceled. Here, unlike the piezoelectric film, the strain gauge has no back and front. The influence of temperature is generated from the grid part for measurement, and if a strain gauge is placed on each of the non-diagonal sides (adjacent two sides) constituting the bridge to cancel it, the temperature change is canceled due to the characteristics of the bridge circuit. (See FIG. 18). In addition, since the strain gauge is arrange | positioned in 2 sets of adjacent 2 sides which comprise a bridge | bridging, the structure of FIG. 17 has a temperature cancellation function.
The strain gauge described above is advantageous for control because an absolute value is output instead of a differential value like a piezoelectric film. Thus, the dust mask of the present invention can be realized even if the respiration sensor is constituted by a strain gauge.

In the following, details of the present invention will be described with reference to examples, but the present invention is not limited to these examples.

In the dust mask of Example 1, the pressure measuring unit 5 is attached to the cheek part of a commercially available dust mask, and an improvement is made in conjunction with the motor for the electric fan (see FIG. 1).
The pressure measuring unit 5 is configured as shown in FIG. 3, the film member 51 is a silicon rubber sheet, and the piezoelectric sensor 52 is a PVDF film. The PVDF film is a rectangular piezoelectric film that outputs a signal corresponding to the strain in the longitudinal direction, and a piezoelectric film manufactured by Tokyo Sensor Co., Ltd. was used. The main specifications of the piezoelectric film used in Example 1 are as follows.

Model number: LDTC-100V
Overall thickness: 203μm
Film thickness: 28μm
Sheet size: 6mm x 12.8mm
Electrode size: 4.2mm x 8mm
Capacitance: 0.244nF

Fig.7 (a) is a figure which shows the measurement result of the pressure change in the face body by respiration in the case of turning off the electric fan. In the figure, the portion surrounded by a dotted line is a voltage change due to inspiration, and the portion surrounded by a solid line is a voltage change due to expiration.
FIG. 7B is a diagram illustrating a measurement result of pressure change in the face due to respiration when the electric fan is turned on. In the figure, the portion surrounded by a dotted line is a voltage change due to inspiration, and the portion surrounded by a solid line is a voltage change due to expiration. In the figure, noise output from the electric fan is also seen, but it is sufficiently possible to determine the expiration state and the inhalation state.
As described above, since the expiration state and the inspiration state can be determined by the output from the piezoelectric sensor 52 regardless of whether the electric fan is ON / OFF, the electric fan motor is controlled according to the change in the expiration state or the inspiration state. Is possible.

The electric fan motor is controlled by supplying power so that the motor normally operates during intake, and supplying power so that the motor stops or the rotation speed decreases during exhaust. When the rotation of the motor is completely stopped, a rise time at the time of restart is required. Therefore, it is preferable to control the in-plane pressure by reducing the number of rotations of the motor. In this embodiment, the rotational speed of the electric fan is controlled by lowering the supply voltage of the DC motor.

FIG. 8 is a diagram showing a change in the pressure in the mask due to respiration. In the figure, the upper waveform is when the electric fan is continuously operated without controlling the electric fan, and the lower waveform is when the rotational speed of the electric fan is controlled. From the figure, by controlling the electric fan, it is possible to reduce the mask internal pressure compared to the case where it is not controlled, and to control the mask internal pressure within a range sufficiently higher than the environmental pressure (approximately 10 to 40 Pa). I was able to confirm that there was.

The dust mask of Example 2 is obtained by improving the film member 51 in the dust mask of Example 1. In the dust mask of Example 1, there existed a subject that the program control for noise suppression by an electric fan became complicated. Therefore, in the second embodiment, the film member 51 has a laminated structure, and the noise problem is solved by measuring at the central thin portion while reducing the noise at the surrounding thick portion.

In Example 2, a laminated structure sheet composed of three layers of silicon rubber sheets was prepared, and the noise reduction effect was confirmed.
The sheet A includes a first film member (upper layer) having a thickness of 0.1 mm, a second film member (lower layer) having a thickness of 0.1 mm, and a third film member (middle layer) having a thickness of 0.1 mm. The first membrane member (upper layer) and the second membrane member (lower layer) are provided with a hole having a diameter of 10 mm in the center portion. A cross-sectional view when the center of the sheet A is cut is shown in the upper part of FIG.
The sheet B includes a first film member (upper layer) having a thickness of 0.1 mm, a second film member (lower layer) having a thickness of 0.1 mm, and a third film member (middle layer) having a thickness of 0.05 mm. The first membrane member (upper layer) and the second membrane member (lower layer) are provided with a hole having a diameter of 10 mm in the center portion. A cross-sectional view when the center of the sheet B is cut is shown in FIG.
The sheet C is composed of a 0.05 mm thick first film member (upper layer), a 0.05 mm thick second film member (lower layer), and a 0.05 mm thick third film member (middle layer). The first membrane member (upper layer) and the second membrane member (lower layer) are provided with a hole having a diameter of 10 mm in the center portion. A cross-sectional view when the center of the sheet C is cut is shown in the lower part of FIG.

Using the sheets A to C described above and the comparative example 1 using one silicon rubber sheet having a thickness of 0.1 mm as the film member 51, the noise reduction effect by the laminated structure sheet was confirmed.
FIG. 11 is a diagram showing measurement results of pressure changes in the face caused by human breathing with the electric fan turned on. (I) is for Comparative Example 1 and (ii) is for Example 2. In the case of the sheet A, (iii) is the case of the sheet B according to the second embodiment, and (iii) is the case of the sheet C according to the second embodiment.
FIG. 12 is a diagram showing measurement results of pressure changes in the face caused by human breathing with the electric fan turned off. (I) is for Comparative Example 1, and (ii) is for Example 2. In the case of the sheet A, (iii) is the case of the sheet B according to the second embodiment, and (iii) is the case of the sheet C according to the second embodiment.

Comparing (i) in FIG. 11 and FIG. 12, it can be seen that noise is generated by the electric fan in Comparative Example 1. Comparing (ii) of FIG. 11 and FIG. 12, seat A can barely recognize the presence or absence of breathing when the electric fan is OFF, but can recognize the presence or absence of breathing when the electric fan is ON. I understand that it is not. Comparing (iii) of FIG. 11 and FIG. 12, it can be confirmed that the noise of the electric fan can be suppressed in the seat B. When comparing (iv) in FIG. 11 and FIG. 12, it can be confirmed that the noise of the electric fan can be suppressed in the sheet C.
From the comparison between the sheets A and B, it is considered that the reason why the respiration was not sufficiently detected by the sheet A was that the third film member (middle layer) having a thickness of 0.1 mm was too thick. From this, it is considered preferable to set the thickness of the third film member (intermediate layer) within a range of 0.3 mm to 0.9 mm, for example.

1 Dust mask 2 Face body 3 Electric fan unit (intake port)
4 exhaust port 5 pressure measurement unit 6 control unit 51 membrane member 52 piezoelectric sensor (respiration sensor)
53 Ventilation channels 54, 55 Fixing member 56 Strain gauge (respiration sensor)
61 cable

Claims

The number of rotations of the faceplate that covers the nostril and mouth of the wearer, the air inlet provided with a filter, the electric fan that sends external breath into the face through the air inlet, the exhaust port, the pressure measuring unit, and the electric fan A respiratory protective device with an electric fan comprising a control unit for controlling,
The pressure measuring unit includes a membrane member that deforms in response to a pressure change in the body, and a respiration sensor that deforms following the movement of the membrane member,
The respirator with an electric fan, wherein the control unit controls the electric fan according to an output signal from the pressure measurement unit.
The respirator with an electric fan according to claim 1, wherein the respiration sensor is composed of a strain gauge.
The respiratory protection device with an electric fan according to claim 2, wherein the strain gauge is composed of an even number and has a function of canceling a voltage generated by heat.
The respirator with an electric fan according to claim 1, wherein the respiration sensor comprises a piezoelectric sensor.
5. The respiratory protective device with an electric fan according to claim 4, wherein the piezoelectric sensor is made of a PVDF film.
The respiration sensor has substantially the same shape and substantially the same element capacity as the first element (A) and the first element (A), and is disposed opposite to the first element (A). And a second element (B), and has a function of canceling a voltage generated by heat applied to the first and second elements. Protective equipment.
The respiratory protective device with an electric fan according to any one of claims 1 to 6, wherein the membrane member is fixed to the face body via a fixing member made of a vibration absorbing material.
The respirator with an electric fan according to any one of claims 1 to 7, wherein the respiration sensor is disposed outside the membrane member.
The respiratory protective device with an electric fan according to any one of claims 1 to 8, wherein the respiration sensor has a long shape in which one end is fixed to the membrane member and the other end is fixed to the fixing member. .
10. The respiratory protective device with an electric fan according to any one of claims 1 to 9, wherein the control unit lowers the rotational speed of the electric fan during exhausting as compared with that during inhalation.