JP2021188982A - Gas concentration flow rate measuring device and oxygen concentrator - Google Patents

Abstract

To provide a gas concentration flow rate measuring device, etc., with which it is possible to compacting the size while securing measurement accuracy.SOLUTION: The gas concentration flow rate measuring device comprises: a measurement unit 20 for forming a measurement path in which a gas circulates; a pair of ultrasonic sensors 60 arranged upstream and downstream of the measurement path, respectively; a proportional valve 80 for adjusting the flow rate of a gas circulating in the measurement path; a temperature sensor 30 for measuring the temperature of the gas circulating in the measurement path; a computation control device for calculating the flow rate of a gas and the concentration of a specific component in the gas; and a device board 50 having a device board pattern for at least electrically connecting the proportional valve 80 and the ultrasonic sensor 60 and supporting the proportional valve 80 and the measurement unit 20. The proportional valve 80 is mounted on the device board 50, and open holes 54 penetrating the device board 50 in the thickness direction are formed around the proportional valve 80.SELECTED DRAWING: Figure 6

Description

The present invention relates to a gas concentration flow rate measuring device for measuring a gas concentration and a flow rate, and an oxygen concentrating device incorporating a gas concentration flow rate measuring device.

Conventionally, as described in Patent Document 1, an ultrasonic type gas concentration flow rate measuring device for measuring the flow rate and concentration of gas by arranging an ultrasonic transmitter / receiver facing each other in a measuring tube through which gas flows has been known. Has been done.

Such a gas concentration flow rate measuring device is also used in an oxygen concentrator. As shown in Patent Document 2, the oxygen concentrator is, for example, a device that removes nitrogen in the air after compressing the air to generate a high concentration of oxygen. The oxygen concentrator is a device used to supply oxygen to a patient who must be supplemented with oxygen at home due to, for example, respiratory failure.

Japanese Patent No. 6305209 Japanese Patent No. 5499265

By the way, the oxygen concentrator described in Patent Document 2 is provided with a valve for adjusting the flow rate of oxygen. For example, if this valve is a solenoid valve, heat is generated from the valve. At present, there is a request to make the gas concentration flow rate measuring device compact, but by making the device compact, the distance between the valve and the measuring tube becomes close, and the gas in the measuring tube due to the heat generated from the valve. The temperature of the gas may change, which may affect the measurement results of gas flow rate and concentration.

Therefore, the present invention provides a gas concentration flow rate measuring device or the like that can be made compact while ensuring measurement accuracy.

The gas concentration flow rate measuring device according to one aspect of the present invention includes a measuring unit that forms a measuring flow path through which gas flows, a pair of ultrasonic sensors arranged on the upstream side and the downstream side of the measuring flow path, respectively. An electromagnetic valve device that adjusts the flow rate of the gas flowing through the measurement flow path, a temperature sensor that measures the temperature of the gas flowing through the measurement flow path, and an ultrasonic wave transmitted from one of the ultrasonic sensors. The flow rate of the gas is calculated based on the difference between the propagation velocity and the propagation velocity of the ultrasonic wave transmitted from the other ultrasonic sensor, and the flow rate of the gas and the propagation velocity of the ultrasonic wave are used to determine the flow rate of the ultrasonic wave. An arithmetic control device that calculates the speed of sound and calculates the concentration of a specific component in the gas based on the speed of sound, the temperature of the gas, and the component of the gas, and at least the electromagnetic valve device and the ultrasonic sensor are electrically operated. The electromagnetic valve device is provided with a device board pattern for connecting the electromagnetic valve device and a device board for supporting the measuring unit, and the electromagnetic valve device is mounted on the device board and around the electromagnetic valve device. Is formed with a through hole penetrating the device substrate in the thickness direction.

Further, in the gas concentration flow rate measuring device, the through hole may have a slit shape.

Further, in the gas concentration flow rate measuring device, the measuring section has a flow path forming section that forms the measuring flow path and extends in the vertical direction of the surface along the surface of the device substrate, and the solenoid valve device and the flow path. The forming portion is provided on the surface of the device board at a position separated from the surface of the device board in the lateral direction perpendicular to the surface direction, and is provided as a through hole in the device board. A vertical slit that is arranged between the flow path forming portion and the solenoid valve device in the lateral direction of the surface and extends in the vertical direction of the surface may be formed.

Further, in the gas concentration flow rate measuring device, the measuring section has a flow path forming section that forms the measuring flow path and extends in the vertical direction of the surface along the surface of the device substrate, and the solenoid valve device and the flow path. The forming portion is provided on the surface of the device board at a position separated from the surface of the device board in the lateral direction perpendicular to the surface direction, and is provided as a through hole in the device board. A plurality of horizontal slits extending in the horizontal direction of the surface and arranged at intervals in the vertical direction of the surface may be formed, and the horizontal slits may be arranged on both outer sides of the solenoid valve device in the vertical direction of the surface.

Further, in the gas concentration flow rate measuring device, the measuring section has a flow path forming section that forms the measuring flow path and extends in the vertical direction of the surface along the surface of the device substrate, and is the solenoid valve device and the flow path. The forming portion is provided on the surface of the device board at a position separated in the horizontal direction of the surface orthogonal to the vertical direction of the surface along the surface of the device board, and is provided on the surface of the device board in the horizontal direction of the surface. A vertical slit arranged between the flow path forming portion and the solenoid valve device and extending in the vertical direction of the surface, and a plurality of horizontal slits extending in the horizontal direction of the surface and arranged at intervals in the vertical direction of the surface. The slits are formed as the through holes, the horizontal slits are arranged on both outer sides of the solenoid valve device in the vertical direction of the surface, and the vertical slits are located at positions separated from the edge of the device substrate in the horizontal direction of the surface. The vertical slit, the horizontal slit, and the edge portion may be arranged so as to surround the solenoid valve device.

Further, in the gas concentration flow rate measuring device, the distance between the flow path forming portion and the solenoid valve device in the lateral direction of the surface is 2.0 times or more the width dimension of the flow path forming portion in the lateral direction of the surface. It may be.

Further, in the gas concentration flow rate measuring device, the distance between the flow path forming portion and the solenoid valve device in the lateral direction of the surface is 3.0 times or less with respect to the width dimension in the lateral direction of the surface of the flow path forming portion. It may be.

Further, the gas concentration flow rate measuring device connects the solenoid valve device and the measuring section, and has a connecting section in which a connecting flow path for flowing the gas is formed between the solenoid valve device and the measuring flow path. Further provided, the measuring unit has a flow path forming portion that forms the measuring flow path and extends in the vertical direction along the surface of the device substrate, and the solenoid valve device and the flow path forming section are the device. It is provided on the surface of the apparatus substrate at a position separated in the horizontal direction of the plane orthogonal to the vertical direction of the plane along the surface of the substrate.
As the connection flow path, the connection portion is connected to a vertical flow path extending in the vertical direction of the surface from the solenoid valve device, a curved flow path communicating with the vertical flow path, and communicating with the curved flow path. A lateral flow path extending in the lateral direction of the surface and communicating with the measurement flow path may be formed.

Further, in the gas concentration flow rate measuring device, the connection portion may be formed of a flexible tube.

Further, in the gas concentration flow rate measuring device, the solenoid valve device is provided with an inlet portion into which the gas flows in and an outlet portion in which the gas flows out, and the outlet portion is lateral to the inlet portion. It is provided on the side away from the solenoid valve device and the flow path forming portion in the direction, and the connecting portion is connected to the outlet portion and is connected to the measuring portion on the upstream side of the measuring flow path to supply the gas. It may be possible to flow from the solenoid valve device into the measurement flow path.

Further, in the gas concentration flow rate measuring device, the solenoid valve device is provided with an inlet portion into which the gas flows in and an outlet portion in which the gas flows out, and the inlet portion is lateral to the outlet portion. It is provided on the side away from the solenoid valve device and the flow path forming portion in the direction, the connection portion is connected to the inlet portion, and is connected to the measurement portion on the downstream side of the measurement flow path to supply the gas. It may be possible to flow into the solenoid valve device from the measurement flow path.

Further, in the gas concentration flow rate measuring device, the connection portion has a vertical cylinder portion in which the vertical flow path is formed inside and extends in the vertical direction of the surface, and the flow path forming portion and the solenoid valve device are described. The distance between the flow path forming portion and the vertical cylinder portion in the lateral direction of the surface may be 1.5 times or more the distance in the lateral direction of the surface.

Further, the oxygen concentrator according to one aspect of the present invention includes the gas concentration flow rate measuring device for measuring the oxygen concentration in the oxygen-containing gas as the gas and the flow rate of the oxygen-containing gas, and the gas concentration flow rate measuring device. It is equipped with a concentrator body that incorporates.

According to the above-mentioned gas concentration flow rate measuring device or the like, it is possible to make it compact while ensuring measurement accuracy.

It is an overall view of the oxygen concentrator which concerns on embodiment of this invention. It is a block diagram which shows the structure of the said oxygen concentrator. It is a block diagram of the gas concentration flow rate measuring apparatus in the said oxygen concentrator. It is an overall perspective view of the gas concentration flow rate measuring apparatus in the said oxygen concentrator. It is an overall perspective view of the gas concentration flow rate measuring device in the said oxygen concentrator, and is the figure which shows by disassembling into the component parts. It is a top view which looked at the apparatus substrate in the said gas concentration flow rate measuring apparatus from the surface. It is a perspective view which shows the connection part in the said gas concentration flow rate measuring apparatus in an enlarged manner.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(overall structure)
As shown in FIGS. 1 and 2, the oxygen concentrator 1 of the present embodiment is a device that supplies oxygen to a patient, concentrates air A taken in from the outside, and has a high concentration (for example, about 90%). Generates oxygen-containing gas G. Specifically, the oxygen concentrator 1 is incorporated into a concentrator main body 100 having an intake filter 11, a compressor 12, a nitrogen adsorption mechanism 13, a tank 14, and a housing 120 (see FIG. 1), and a concentrator main body 100. It is equipped with a gas concentration flow rate measuring device 15.

In the oxygen concentrator 1, the air A taken in from the outside is compressed by the compressor 12 through the intake filter 11 provided on the back surface of the housing 120, and the nitrogen contained in the compressed air A is compressed by the nitrogen adsorption mechanism 13. To generate an oxygen-containing gas (gas containing oxygen and nitrogen) G containing a high concentration of oxygen by adsorbing it to a catalyst (not shown), the gas can be supplied to the patient. Hereinafter, the oxygen-containing gas G is simply referred to as “gas G”.

Here, as shown in FIG. 2, the nitrogen adsorption mechanism 13 includes a pair of adsorption towers 13a and 13b. The pair of adsorption towers 13a and 13b are filled with a catalyst such as zeolite. One of the adsorption towers 13a and 13b is pressurized to adsorb nitrogen to the catalyst, and the other is depressurized to release the nitrogen adsorbed by the catalyst to prepare for the next pressurization. As described above, in the nitrogen adsorption mechanism 13, the pair of adsorption towers 13a and 13b are alternately pressurized and depressurized to generate high-concentration oxygen. The high-concentration oxygen generated by the nitrogen adsorption mechanism 13 is stored in the tank 14. The oxygen stored in the tank 14 is supplied to the patient as gas G after passing through the gas concentration flow rate measuring device 15. That is, the oxygen concentrator 1 of the present embodiment employs a PSA (Pressure Swing Attachment) method.

Here, each component of the oxygen concentrator 1 is collectively controlled by a control unit (not shown). The control unit is composed of a CPU, RAM, ROM, and the like, and executes various controls. The CPU is a so-called central processing unit, and various programs are executed to realize various functions. The RAM is used as a work area for the CPU. The ROM stores a program executed by the CPU.

As shown in FIG. 1, the housing 120 has a substantially rectangular parallelepiped shape. The housing 120 is provided with an operation button 121, a display 122, and a discharge tube (rubber tube or the like) 123 connected to the gas concentration flow rate measuring device 15 to discharge the gas G.

(Gas concentration flow rate measuring device)
Next, the details of the gas concentration flow rate measuring device 15 will be described.
The gas concentration flow rate measuring device 15 is incorporated in the housing 120. As shown in FIG. 2, the gas concentration flow rate measuring device 15 is provided on the downstream side of the tank 14 and can measure the concentration and flow rate of oxygen in the gas G. More specifically, as shown in FIG. 3, the gas concentration flow rate measuring device 15 is an ultrasonic measuring device, and includes a measuring unit 20, a temperature sensor 30, an arithmetic control device 40, a device board 50, and the like. It includes an ultrasonic sensor 60, a pressure sensor 70, a proportional valve (electromagnetic valve device) 80, and a connection portion 84.

(Device board)
As shown in FIGS. 4 and 5, the apparatus substrate 50 is a rectangular printed circuit board having a pair of edge edges 50a and a pair of edge edges 50b orthogonal to the edge edges 50a, and is formed on the substrate 51 and the substrate 51. It has a device board pattern 52 provided and formed by a conductor, and a plurality of device board lands 53 provided around the device board hole 51a penetrating the base material 51 and electrically connected to the device board pattern 52. is doing. The device board hole 51a is a hole for inserting and mounting each electronic component described later, but a device board land 53 without the device board hole 51a is also provided, and each electronic component described later is surface-mounted on the device board 50. May be done.
An element board 62, which will be described later, is electrically connected to some device board lands 53.

Further, as shown in FIG. 6, the apparatus substrate 50 is formed with a through hole 54 penetrating in the thickness direction. The through hole 54 is formed around the proportional valve 80 described later. In the present embodiment, the through hole 54 has a slit shape. Further, as through holes 54 in the device board 50, a vertical slit 55 extending in the vertical direction of the surface along the surface of the device board 50 and a horizontal slit 56 extending in the horizontal direction of the surface along the surface of the device board 50 and orthogonal to the vertical direction of the surface are provided. And are formed. In this embodiment, the device substrate 50 has a rectangular shape. The vertical slit 55 is formed parallel to the edge 50a of the device substrate 50. Further, the horizontal slit 56 is formed parallel to the edge 50b of the device substrate 50.

A plurality of vertical slits 55 are provided side by side at the same position in the horizontal direction of the surface at intervals in the vertical direction of the surface. The vertical slit 55 is arranged at a position separated from the edge 50a of the apparatus substrate 50 in the lateral direction of the surface. Further, a plurality of horizontal slits 56 are provided in pairs at intervals in the vertical direction of the surface. The vertical slits 55 are arranged between the horizontal slits 56 that form a pair in the vertical direction of the surface. Since the horizontal slit 56 is formed between the vertical slit 55 and the edge 50a, the valve arrangement region S, which is a region surrounded by the vertical slit 55, the horizontal slit 56, and the edge 50a, is the device substrate 50. It is formed on the surface. A proportional valve 80, which will be described later, is arranged in the valve arrangement region S.

(Temperature sensor)
As shown in FIG. 5, the temperature sensor 30 is provided on the surface of the device substrate 50. The temperature sensor 30 can measure the temperature T of the gas flowing through the measurement flow path F, which will be described later, on the downstream side of the measurement flow path F. The temperature sensor 30 is fixed to the device board land 53 by soldering and is electrically connected to the device board pattern 52 (see FIG. 4).

(Pressure sensor)
The pressure sensor 70 is provided on the surface of the device substrate 50 in the same manner as the temperature sensor 30. The pressure sensor 70 can measure the pressure of the gas G flowing through the measurement flow path F, which will be described later, on the upstream side of the measurement flow path F. The pressure sensor 70 is fixed to the device board land 53 by soldering and is electrically connected to the device board pattern 52 (see FIG. 4). The pressure of the gas G measured by the pressure sensor 70 is used, for example, in the calculation in the calculation control device 40 (see FIG. 3) described later, when determining a constant that can fluctuate depending on the pressure.

(Measurement unit)
As shown in FIGS. 4 and 5, the measuring unit 20 is fixedly provided on the surface of the device substrate 50. Hereinafter, the direction away from the front surface with respect to the device substrate 50 is defined as the upper side of the substrate, and the direction away from the back surface opposite to the front surface of the device substrate 50 is defined as the lower side of the substrate. The measuring unit 20 has a cylindrical shape. More specifically, the measuring section 20 includes a measuring tube (flow path forming section) 21, an ultrasonic sensor mounting section 22 provided at both ends of the measuring tube 21, a temperature sensor mounting section 23, a discharge port section 24, and a suction port. It has a mouth portion 25 and a pressure sensor mounting portion 26.

(Measuring tube)
The measuring tube 21 has a cylindrical shape that forms a measuring flow path F through which the gas G from the tank 14 (see FIG. 3) flows. The measuring tube 21 is made of a resin material such as ABS resin.

Hereinafter, the extending direction of the measuring tube 21 is referred to as the longitudinal direction of the measuring portion. The longitudinal direction of the measuring portion coincides with the above-mentioned vertical direction of the plane. Further, the radial direction of the measuring tube 21 orthogonal to the longitudinal direction of the measuring portion is defined as the radial direction of the measuring portion. Of the radial directions of the measuring portions, the direction along the surface of the device substrate 50 coincides with the above-mentioned lateral direction of the surface.

(Ultrasonic sensor mounting part)
The ultrasonic sensor mounting portions 22 are provided at both ends of the measuring tube 21 in the longitudinal direction of the measuring portion, that is, one at each end on the upstream side and the downstream side of the measuring flow path F. In this embodiment, the ultrasonic sensor mounting portion 22 is integrally molded with the measuring tube 21 with the same resin as the measuring tube 21. The ultrasonic sensor mounting portion 22 has a cylindrical shape having a larger outer diameter than the measuring tube 21. As shown in FIG. 5, each ultrasonic sensor mounting portion 22 is formed with an opening 22a which is a hole having a circular cross section that penetrates in the longitudinal direction of the measuring portion and connects to the measuring flow path F.

(Temperature sensor mounting part)
As shown in FIGS. 4 and 5, the temperature sensor mounting portion 23 is provided so as to project downward from the outer peripheral surface of the measuring tube 21 at a position close to the ultrasonic sensor mounting portion 22X on the downstream side of the measurement flow path F. ing. In the present embodiment, the temperature sensor mounting portion 23 is integrally molded with the measuring tube 21 with the same resin as the measuring tube 21. A space (not shown) connected to the measurement flow path F is formed inside the temperature sensor mounting portion 23. This space opens toward the lower side of the substrate, and the temperature sensor mounting portion 23 is provided in contact with the surface of the apparatus substrate 50 so as to cover the temperature sensor 30 provided on the apparatus substrate 50 from above the substrate. The temperature sensor mounting portion 23 is mounted on the device board 50 by, for example, a bolt 35.

(Discharge port)
The discharge port portion 24 is provided in the temperature sensor mounting portion 23 at a position close to the ultrasonic sensor mounting portion 22X on the downstream side of the measurement flow path F. In the present embodiment, the discharge port portion 24 is integrally molded with the temperature sensor mounting portion 23 with the same resin as the temperature sensor mounting portion 23. Then, as shown in FIGS. 4 and 5, the discharge port portion 24 protrudes outward from the temperature sensor mounting portion 23 along the surface of the device substrate 50 in the radial direction of the measuring portion and passes through the space in the temperature sensor mounting portion 23. It communicates with the measurement flow path F. Therefore, the gas G flowing through the measurement flow path F is discharged from the discharge port portion 24 via the temperature sensor mounting portion 23.

(Suction port)
The suction port portion 25 projects from the outer peripheral surface of the measuring tube 21 to the outside in the radial direction of the measuring portion along the surface of the device substrate 50 at a position close to the ultrasonic sensor mounting portion 22Y on the upstream side of the measuring flow path F. It extends parallel to the outlet portion 24. In the present embodiment, the suction port portion 25 is integrally molded with the measuring tube 21 with the same resin as the measuring tube 21. The suction port portion 25 has a cylindrical shape and communicates with the measurement flow path F. The suction port portion 25 is connected to the tank 14 via a proportional valve 80 described later (see FIG. 2). Therefore, the gas G flows from the tank 14 into the measurement flow path F through the suction port portion 25.

(Pressure sensor mounting part)
The pressure sensor mounting portion 26 is provided in the suction port portion 25. In the present embodiment, the pressure sensor mounting portion 26 is integrally molded with the pressure sensor mounting portion 26 with the same resin as the suction port portion 25. The pressure sensor mounting portion 26 has a cylindrical shape and projects downward from the suction port portion 25 to the lower side of the substrate. A space (not shown) connected to the inside of the suction port 25 is formed inside the pressure sensor mounting portion 26. This space opens toward the lower side of the substrate, and the pressure sensor mounting portion 26 is provided in contact with the surface of the apparatus substrate 50 so as to cover the pressure sensor 70 provided on the apparatus substrate 50 from above the substrate. The pressure sensor mounting portion 26 is mounted on the device board 50 by, for example, a claw 75.

(Proportional valve)
The proportional valve 80 is fixedly provided on the surface of the device substrate 50. The proportional valve 80 is on the side where the suction port portion 25 and the discharge port portion 24 are provided with respect to the measuring tube 21, and the suction port portion is provided in the longitudinal direction of the measuring portion along the edge 50a extending in the vertical direction of the surface of the device substrate 50. It is arranged between the 25 and the discharge port portion 24. Further, the proportional valve 80 is arranged at a position separated from the measuring tube 21 in the lateral direction (measurement portion radial direction). Further, the proportional valve 80 is placed on the device substrate 50 in the valve arrangement region S surrounded by the vertical slit 55, the horizontal slit 56, and the end edge 50a. As a result, the horizontal slits 56 are arranged on both outer sides in the vertical direction of the surface with respect to the proportional valve 80. The proportional valve 80 controls the flow rate of the gas G flowing through the measurement flow path F based on the numerical value specified by the operation button 121 of the concentrator main body 100.

In the proportional valve 80, a part of the proportional valve 80 protrudes from the end edge 50a of the device board 50 in the lateral direction (measurement portion radial direction) and is interposed between the device board 50 and the proportional valve 80. 81 is provided. The proportional valve bracket 81 is attached to the proportional valve 80 by, for example, a bolt 85. Further, the proportional valve bracket 81 supports the proportional valve 80 from below the substrate. The proportional valve bracket 81 is provided with a claw 81a projecting downward from the substrate. The proportional valve bracket 81 is attached to the device board 50 by inserting the claw 81a into the receiving hole 51b penetrating the device board 50 in the thickness direction and locking the claw 81a. The proportional valve bracket 81 is placed in the valve arrangement region S on the surface of the device substrate 50 together with the proportional valve 80. Further, the proportional valve bracket 81 is provided with an inlet portion 82 connected to the tank 14 and an outlet portion 83 connected to the suction port portion 25.

The inlet portion 82 has a cylindrical shape extending toward the suction port portion 25 in the longitudinal direction of the measuring portion along the edge 50a of the device substrate 50.
The outlet portion 83 is attached to the inlet portion 82, and is arranged on the side opposite to the proportional valve 80 in the lateral direction (measurement portion radial direction) along the surface of the device substrate 50 with the inlet portion 82 interposed therebetween. In other words, the outlet portion 83 is provided on the side away from the proportional valve 80 and the measuring tube 21 in the lateral direction with respect to the inlet portion 82. Like the inlet portion 82, the outlet portion 83 has a cylindrical shape extending toward the suction port portion 25 in the longitudinal direction of the measurement portion along the edge 50a of the device substrate 50. The inlet portion 82 and the outlet portion 83 communicate with each other via a proportional valve 80. A packing 86 is interposed between the inlet portion 82 and the outlet portion 83 and the proportional valve 80.

Here, as shown in FIG. 6, the distance L1 in the lateral direction between the measuring tube 21 and the proportional valve 80 is 2.0 times or more and 3.0 times or less with respect to the width dimension W in the lateral direction of the measuring tube 21. It is better if it is 2.5 times or more and 2.6 times or less.

(Connection part)
The connecting unit 84 connects the proportional valve 80 and the measuring unit 20. More specifically, the connecting portion 84 connects the outlet portion 83 of the proportional valve bracket 81 and the suction port portion 25 of the measuring unit 20. In this embodiment, the connecting portion 84 is formed of a flexible tube.

As shown in FIG. 7, a connection flow path C is formed in the connection portion 84. A vertical flow path C1, a curved flow path C2, and a horizontal flow path C3 are formed as a connection flow path C in the connection portion 84 of the present embodiment. The vertical flow path C1 extends from the outlet portion 83 in the vertical direction of the surface (longitudinal direction of the measuring portion). The curved flow path C2 communicates with the vertical flow path C1 and is curved. The extending direction of the connecting flow path C is changed from the surface vertical direction to the surface horizontal direction by the curved flow path C2. Here, the portion of the connecting portion 84 in which the vertical flow path C1 is formed is referred to as the vertical cylinder portion 84A, and the portion in which the curved flow path C2 is formed is referred to as the curved cylinder portion 84B. In the present embodiment, the connection flow path C and the connection portion 84 are curved by about 90 degrees in an arc shape at the position of the curved cylinder portion 84B. Further, the lateral flow path C3 communicates with the curved flow path C2, extends in the lateral direction (measurement portion radial direction), and communicates with the measurement flow path F via the suction port portion 25 (see FIGS. 4 and 5). The portion where the transverse flow path C3 is formed is referred to as the transverse cylinder portion 84C.

Returning to FIG. 6, in the present embodiment, the lateral distance L2 between the measuring tube 21 and the vertical cylinder portion 84A is 1.5 times the lateral distance L1 between the measuring tube 21 and the proportional valve 80. It is better if it is more than 2.0 times, and even better if it is 2.0 times or more.

Then, the gas G in the tank 14 flows into the inlet portion 82 of the proportional valve bracket 81, flows into the outlet portion 83 via the proportional valve 80, and flows from the suction port portion 25 via the connection flow path C of the connection portion 84. It flows into the measurement flow path F. The proportional valve 80 is feedback-controlled by the arithmetic control device 40 so that the flow rate of the gas G calculated by the arithmetic control device 40 (see FIG. 2) described later becomes the flow rate specified by the operation button 121. It has become.

(Ultrasonic sensor)
Returning to FIG. 5, each ultrasonic sensor 60 is provided one by one in the ultrasonic sensor mounting portion 22 in the measuring unit 20. Therefore, the ultrasonic sensor 60 is arranged so as to face the upstream side and the downstream side of the measurement flow path F. Each ultrasonic sensor 60 has an ultrasonic element 61, an element substrate 62 that supports the ultrasonic element 61, and a substrate terminal 63 provided on the element substrate 62.

(Ultrasonic element)
The ultrasonic element 61 is a transmitter / receiver capable of transmitting and receiving ultrasonic waves. The ultrasonic element 61 is arranged in the opening 22a of the ultrasonic sensor mounting portion 22 in the measuring unit 20. The ultrasonic waves transmitted from the ultrasonic element 61A on the upstream side of the measurement flow path F can be received by the ultrasonic element 61B on the downstream side of the measurement flow path F. On the other hand, the ultrasonic waves transmitted from the ultrasonic element 61B on the downstream side of the measurement flow path F can be received by the ultrasonic element 61A on the upstream side of the measurement flow path F. The ultrasonic element 61 has a columnar shape and extends in the longitudinal direction of the measuring portion while being installed in the opening 22a.

(Element board)
The element substrate 62 is a rectangular printed circuit board, and the ultrasonic element 61 is electrically connected to the element substrate 62. The element substrate 62 is fixed to the ultrasonic sensor mounting portion 22 of the measuring unit 20 by a bolt 90 in a state of being arranged so as to face the measuring unit 20 in the longitudinal direction of the measuring unit.

Here, in the element substrate 62, the seal ring 69 is provided in contact with the surface facing the measurement unit 20 in the longitudinal direction of the measurement unit. The seal ring 69 is a packing made of resin. The seal ring 69 is provided on the outer peripheral side of the ultrasonic element 61 and the opening 22a. The seal ring 69 is crushed and elastically deformed in a state where the element substrate 62 is fixed to the measurement unit 20 by the bolt 90, that is, the element substrate 62 is pressed against the measurement unit 20, and the element substrate 62 and the ultrasonic sensor mounting portion are attached. The gap between the 22 and the 22 is sealed.

(Board terminal)
The substrate terminal 63 is supported by the element substrate 62 and is provided on the same side as the ultrasonic element 61 in the longitudinal direction of the measuring portion. The other end of the board terminal 63 projects downward from the element board 62 and is electrically connected to the device board 50.

In the present embodiment, the element substrate 62 is erected on the apparatus substrate 50 toward the upper side of the substrate so that the surface of the element substrate 62 intersects (orthogonally) with the surface of the apparatus substrate 50. 62 is exposed on the surface of the device substrate 50.

(Calculation control device)
Returning to FIG. 2, the arithmetic control device 40 is composed of a CPU, RAM, ROM, and the like. The CPU is a so-called central processing unit, and various programs are executed to realize various functions. The RAM is used as a work area for the CPU. The ROM stores a program executed by the CPU. In the present embodiment, the arithmetic control device 40 is provided on the back surface of the device board 50 (see FIG. 5).

_{The arithmetic control device 40 includes an ultrasonic wave propagation velocity v FWD} [m / s] from being transmitted from the upstream ultrasonic wave element 61A to being received by the downstream ultrasonic wave element 61B, and the downstream ultrasonic wave element. _{The propagation speed v REV} [m / s] of the ultrasonic wave transmitted from 61B and received by the ultrasonic element 61A on the upstream side is calculated, and the measurement is performed based on the difference _{between these propagation speeds v FWD} and v _REV. ^{The flow rate Q [m 3} / s] of the gas G flowing through the flow path F is calculated.

The above propagation velocities v _FWD and v _REV are calculated by the following equations (1) and (2). The length of the measurement flow path F (distance between the ultrasonic elements 61A and 61B) is L [m]. Further, the propagation time of the ultrasonic wave from the ultrasonic element 61A on the upstream side to the reception by the ultrasonic element 61B on the downstream side is set to t _FWD [s], and is transmitted from the ultrasonic element 61B on the downstream side. _{Let t REV} [s] be the propagation time of the ultrasonic wave until it is received by the ultrasonic element 61A on the upstream side.

Here, the arithmetic control device 40 uses the above equations (1) and (2), and the following equations (5) derived from the following equations (3) and (4) to flow through the gas G flowing through the measurement flow path F. Calculate v [m / s]. The speed of sound of the ultrasonic wave in the measurement flow path F is c [m / s].

^{Then, the arithmetic control device 40 calculates the flow rate Q [m 3} / s] of oxygen flowing through the measurement flow path F by the following equation (6). The cross-sectional area of the measurement flow path F is A [m ² ]. The arithmetic control device 40 controls the opening degree of the proportional valve 80 so that the calculated flow rate Q becomes a preset flow rate.

Next, the arithmetic control device 40 calculates the sound wave c [m / s] of the ultrasonic wave in the measurement flow path F by the following equation (7) derived from the above equations (1) to (5).

Here, the speed of sound c [m / s] of the ultrasonic wave propagating in the gas can be expressed by a function of the average molecular weight M [g / mol] of the gas and the temperature T [K] of the gas. That is, the speed of sound c [m / s] is calculated by the following equation (8). In addition, k is a specific heat ratio and R is a gas constant. The temperature T [K] of the gas G is a value measured by the temperature sensor 30, and in the present embodiment, it is assumed that the gas G flowing through the measurement flow path F is a mixed gas composed of two molecules of oxygen and nitrogen, and k = 1. Let it be 4.

The arithmetic control device 40 calculates the average molecular weight M [g / mol] of the gas G in the measurement flow path F from the above equations (7) and (8). Then, based on the calculated average molecular weight M [g / mol], the oxygen concentration _PO2 [%] in the gas G is calculated by the following formula (9). _MO2 [g / mol] is the molecular weight of oxygen, and _MN2 [g / mol] is the molecular weight of nitrogen. _MO2 = 32 and _MN2 = 28. The arithmetic control device 40 transmits a signal to the above control unit (not shown) so that the oxygen concentration becomes a preset value, and the nitrogen adsorption mechanism 13 is controlled by this control unit.

In the oxygen concentrator 1 of the present embodiment described above, in the gas concentration flow rate measuring device 15, the proportional valve 80 and the measuring unit 20 are provided on the surface side of the device substrate 50, and the proportional valve 80 is a device together with the proportional valve bracket 81. It is placed on the surface of the substrate 50. Therefore, when the proportional valve 80 generates heat, the heat is transferred from the proportional valve 80 to the measuring unit 20 via the device substrate 50. In this case, the gas G in the measurement flow path F of the measuring unit 20 may be heated, and the measurement accuracy by the gas concentration flow rate measuring device 15 may decrease.

Here, in the present embodiment, a through hole 54 is formed around the proportional valve 80 in the apparatus substrate 50. Therefore, a space is formed on the device substrate 50 between the proportional valve 80 and the measuring unit 20 by the through hole 54, and it becomes difficult for heat to be transferred from the proportional valve 80 to the measuring unit 20. Therefore, even if the measuring unit 20 and the proportional valve 80 are arranged close to each other on the device substrate 50, the possibility that the gas in the measuring flow path F is heated by the heat of the proportional valve 80 can be reduced. As a result, the gas concentration flow rate measuring device 15 can be made compact while ensuring the measurement accuracy.
In particular, the distance L1 in the lateral direction between the measuring tube 21 and the proportional valve 80 is 2.0 times or more and 3.0 times or less, more preferably 2.5, with respect to the width dimension W in the lateral direction of the measuring tube 21. Since it is doubled or more and 2.6 times or less, the distance between the measuring tube 21 and the proportional valve 80 can be shortened and the entire device can be made compact while obtaining the heat shielding effect by the through hole 54.

Further, since the through hole 54 has a slit shape, the volume of the space between the proportional valve 80 and the measuring unit 20 can be increased as compared with the case where the through hole 54 is a circular hole, and the heat shield can be increased. The effect can be enhanced. The vertical slit 55 is provided so as to partition between the measuring tube 21 and the proportional valve 80. Therefore, since it is possible to prevent the heat of the proportional valve 80 from reaching the measuring unit 20 in the shortest path, the heat shielding effect can be further enhanced by the vertical slit 55.

The proportional valve 80 is provided in the valve arrangement region S surrounded by the vertical slit 55, the horizontal slit 56, and the edge 50a of the device substrate 50. Therefore, as compared with the case where only the vertical slit 55 is provided, the heat transferred from the proportional valve 80 in the vertical direction of the surface can be cut off by the horizontal slit 56, so that the heat shielding effect can be further improved.

Further, by arranging the proportional valve 80 and the measuring tube 21 at positions separated from each other in the lateral direction (measurement portion radial direction), the outlet portion 83 in the proportional valve bracket 81 and the suction port portion 25 in the measuring portion 20 The distance between can be secured. For example, when the outlet portion 83 and the suction port portion 25 are close to each other, the outlet portion 83 and the suction port portion 25 must be connected by a connection portion having a connection flow path that bends at a steep angle. In the present embodiment, the outlet portion 83 and the suction port portion 25 are separated from each other, and more preferably, the measuring tube 21 and the vertical cylinder portion are separated from each other with respect to the lateral distance L1 between the measuring tube 21 and the proportional valve 80. When the distance L2 in the lateral direction with the 84A is 1.5 times or more, more preferably 2.0 times or more, a curved flow path C2 is formed between the outlet portion 83 and the suction port portion 25. It can be connected by the connecting portion 84. Therefore, the flow of the gas G flowing from the proportional valve 80 to the measuring unit 20 can be smoothed, the generation of turbulent flow in the connecting flow path C can be suppressed, and the measurement accuracy can be improved.

Further, the outlet portion 83 is provided on the side away from the proportional valve 80 and the measuring portion 20 in the lateral direction (diameter direction of the measuring portion) with respect to the inlet portion 82. Therefore, the distance between the outlet portion 83 and the suction port portion 25 can be increased, and the outlet portion 83 and the suction port portion 25 can be connected without bending the connection flow path C at a steep angle. .. Therefore, the flow of gas G can be further smoothed.

The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.
For example, the connecting portion 84 does not have to be a flexible tube and may be formed of the same resin as the measuring portion 20.

Further, the proportional valve 80 may be connected to the discharge port portion 24 of the measuring portion 20 via the connecting portion 84. In this case, it is preferable that the inlet portion 82 is arranged on the side away from the proportional valve 80 and the measuring portion 20 in the lateral direction (measurement portion radial direction) of the outlet portion 83. Even with such a configuration, the distance between the inlet portion 82 and the discharge port portion 24 can be increased as in the above embodiment, and the inlet portion 82 and the discharge port portion 24 can be provided without bending the connection flow path C at a steep angle. Can be connected. Therefore, the flow of gas G can be smoothed.

Further, the number and shape of the through holes 54 of the device substrate 50 are not limited in the case of the above embodiment. For example, the through hole 54 may be a hole having a circular cross section. In this case, a plurality of through holes 54 may be formed in close proximity to each other as in the case of punching metal.

Further, the horizontal slit 56 does not necessarily have to be provided, and only the vertical slit 55 may be provided. Further, only the horizontal slit 56 may be provided. Further, in the above embodiment, the valve arrangement region S is formed by the vertical slit 55, the horizontal slit 56, and the end edge 50a. By arranging the horizontal slits 56 forming a pair at intervals in the vertical direction of the surface (longitudinal direction of the measuring portion) between the vertical slits 55 forming the pair, a quadrangular valve arrangement area is formed. May be formed. That is, the proportional valve 80 may be placed on the device substrate 50 at a position away from the end edge 50a, and the entire circumference of the proportional valve 80 may be surrounded by the vertical slit 55 and the horizontal slit 56, and the installation position of the proportional valve 80 is described above. Not limited to the case of.

For example, the arithmetic control device 40 may be installed in a place different from the device board 50. Further, the method of fixing the measuring unit 20 to the device substrate 50 is not limited to the above case. The installation positions of the temperature sensor 30 and the pressure sensor 70 are not limited to the above cases.

Further, the gas concentration flow rate measuring device 15 can be used for devices other than the oxygen concentrator 1. Further, the oxygen concentrator 1 is not limited to the PSA type device, and may be a device using another method such as a membrane separation method.

According to the gas concentration flow rate measuring device or the like of the present invention, it is possible to make the measurement compact while ensuring the measurement accuracy.

1 Oxygen concentrator 15 Gas concentration flow rate measuring device 20 Measuring unit 21 Measuring tube (flow path forming unit)
22a Opening 30 Temperature sensor 40 Calculation control device 50 Device board 52 Device board pattern 53 Device board Land 54 Through hole 55 Vertical slit 56 Horizontal slit 60 Ultrasonic sensor 61 (61A, 61B) Ultrasonic element 62 Element board 63 Board terminal 69 Seal Ring 80 Proportional valve (electromagnetic valve device)
84 Connection part 84A Vertical cylinder part 90 Volt 100 Concentrator body F Measurement flow path A Air G Oxygen-containing gas C Connection flow path C1 Vertical flow path C2 Curved flow path C3 Horizontal flow path

Claims (13)

A measuring unit that forms a measuring flow path through which gas flows,
A pair of ultrasonic sensors arranged on the upstream side and the downstream side of the measurement flow path, respectively,
A solenoid valve device that adjusts the flow rate of the gas flowing through the measurement flow path, and
A temperature sensor that measures the temperature of the gas flowing through the measurement flow path,
The flow rate of the gas is calculated based on the difference between the propagation speed of the ultrasonic wave transmitted from one of the ultrasonic sensors and the propagation speed of the ultrasonic wave transmitted from the other ultrasonic sensor, and the flow rate of the gas is calculated. An arithmetic control device that calculates the speed of sound of the ultrasonic wave from the flow rate and the propagation speed of the ultrasonic wave, and calculates the concentration of a specific component in the gas based on the speed of sound, the temperature of the gas, and the component of the gas. ,
A device board that has at least a device board pattern that electrically connects the solenoid valve device and the ultrasonic sensor, and supports the solenoid valve device and the measurement unit, and a device board that supports the solenoid valve device and the measurement unit.
Equipped with
The solenoid valve device is mounted on the device board and is mounted on the device board.
A gas concentration flow rate measuring device in which a through hole penetrating the device substrate in the thickness direction is formed around the solenoid valve device. The gas concentration flow rate measuring device according to claim 1, wherein the through hole has a slit shape. The measuring unit has a flow path forming unit that forms the measuring flow path and extends in the vertical direction along the surface of the apparatus substrate.
The solenoid valve device and the flow path forming portion are provided on the surface of the device board at positions separated from each other in the horizontal direction of the plane orthogonal to the vertical direction of the surface along the surface of the device board.
The second aspect of the present invention, wherein a vertical slit is formed in the device substrate as the through hole, which is arranged between the flow path forming portion and the solenoid valve device in the lateral direction of the surface and extends in the vertical direction of the surface. Gas concentration flow measuring device. The measuring unit has a flow path forming unit that forms the measuring flow path and extends in the vertical direction along the surface of the apparatus substrate.
The solenoid valve device and the flow path forming portion are provided on the surface of the device board at positions separated from each other in the horizontal direction of the plane orthogonal to the vertical direction of the surface along the surface of the device board.
A plurality of horizontal slits extending in the lateral direction of the surface and arranged at intervals in the vertical direction of the surface are formed in the device substrate as the through holes.
The gas concentration flow rate measuring device according to claim 2 or 3, wherein the horizontal slits are arranged on both outer sides of the solenoid valve device in the vertical direction of the surface. The measuring unit has a flow path forming unit that forms the measuring flow path and extends in the vertical direction along the surface of the apparatus substrate.
The solenoid valve device and the flow path forming portion are provided on the surface of the device board at positions separated from each other in the horizontal direction of the plane orthogonal to the vertical direction of the surface along the surface of the device board.
The device substrate has a vertical slit arranged between the flow path forming portion and the solenoid valve device in the horizontal direction of the surface and extending in the vertical direction of the surface, and extending in the horizontal direction of the surface and in the vertical direction of the surface. A plurality of lateral slits arranged at intervals are formed as the through holes.
The horizontal slits are arranged on both outer sides of the solenoid valve device in the vertical direction of the surface.
The vertical slit is provided at a position separated from the edge of the device substrate in the lateral direction of the surface.
The gas concentration flow rate measuring device according to claim 2, wherein the vertical slit, the horizontal slit, and the edge portion are arranged so as to surround the solenoid valve device. Claims 3 to 5 in which the distance between the flow path forming portion and the solenoid valve device in the lateral direction of the surface is 2.0 times or more the width dimension in the lateral direction of the surface of the flow path forming portion. The gas concentration flow rate measuring device according to any one of the above items. The sixth aspect of claim 6 in which the distance between the flow path forming portion and the solenoid valve device in the lateral direction of the surface is 3.0 times or less with respect to the width dimension in the lateral direction of the surface of the flow path forming portion. Gas concentration flow measuring device. The solenoid valve device and the measuring section are connected to each other, and a connecting section is further provided in which a connecting flow path for circulating the gas is formed between the solenoid valve device and the measuring flow path.
The measuring unit has a flow path forming unit that forms the measuring flow path and extends in the vertical direction along the surface of the apparatus substrate.
The solenoid valve device and the flow path forming portion are provided on the surface of the device board at positions separated from each other in the horizontal direction of the plane orthogonal to the vertical direction of the surface along the surface of the device board.
In the connection portion, as the connection flow path,
A vertical flow path that extends in the vertical direction of the surface from the solenoid valve device, a curved flow path that communicates with the vertical flow path and curves, and a curved flow path that communicates with the curved flow path and extends in the lateral direction of the surface to the measurement flow path. The gas concentration flow rate measuring device according to any one of claims 1 to 7, wherein a communicating lateral flow path is formed. The gas concentration flow rate measuring device according to claim 8, wherein the connection portion is formed of a flexible tube. The solenoid valve device is provided with an inlet portion into which the gas flows in and an outlet portion through which the gas flows out.
The outlet portion is provided on the side away from the solenoid valve device and the flow path forming portion in the lateral direction of the surface with respect to the inlet portion.
8. The gas concentration flow rate measuring device according to. The solenoid valve device is provided with an inlet portion into which the gas flows in and an outlet portion through which the gas flows out.
The inlet portion is provided on the side away from the solenoid valve device and the flow path forming portion in the lateral direction of the surface with respect to the outlet portion.
8. The gas concentration flow rate measuring device according to. The connection portion has a vertical cylinder portion in which the vertical flow path is formed inward and extends in the vertical direction of the surface.
The distance between the flow path forming portion and the vertical cylinder portion in the lateral direction of the surface is 1.5 times or more the distance between the flow path forming portion and the solenoid valve device in the lateral direction of the surface. The gas concentration flow rate measuring device according to any one of claims 8 to 11. The gas concentration flow rate measuring device according to any one of claims 1 to 12, which measures the oxygen concentration in the oxygen-containing gas as the gas and the flow rate of the oxygen-containing gas.
The main body of the concentrator incorporating the gas concentration flow rate measuring device and
An oxygen concentrator equipped with.

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