WO2019097684A1 - Ultrasonic flow rate meter and method of using same - Google Patents

Abstract

This invention provides an ultrasonic flow rate meter that enables a flow rate measurement tube to be replaced easily and prevents the flow rate measurement tube from falling off. This ultrasonic flow rate meter 20 measures the flow rate of a fluid on the basis of a difference in transmission time of ultrasonic waves that are sent and received between ultrasonic sensors 21, 22. The ultrasonic sensors 21, 22 transmit ultrasonic waves alternately through a flow rate measurement tube 11. A measurement tube holder 42 has a measurement tube housing section 43 that covers the flow rate measurement tube 11 such that both end sections of the flow rate measurement tube 11 are exposed. A first sensor cover 51 houses the ultrasonic sensor 21 and is coupled to a first end 42a of the measurement tube holder 42. A second sensor cover 61 houses the ultrasonic sensor 22 and is coupled to a second end 42b of the measurement tube holder 42. At least one of the first sensor cover 51 and the second sensor cover 61 is detachably attached to the measurement tube holder 42.

Description

Ultrasonic flow meter and method of using the same

The present invention relates to an ultrasonic flowmeter that measures the flow rate of liquid using ultrasonic waves and a method of using the same.

Conventionally, various ultrasonic flowmeters that measure the flow rate of liquid have been proposed as measurement devices using ultrasonic waves (see, for example, Patent Documents 1 to 4). In this ultrasonic flow meter, a flow rate measuring pipe is provided in the middle of a pipe through which liquid flows, and ultrasonic sensors are respectively installed at the upstream side position and the downstream side position of the flow rate measuring pipe. Then, ultrasonic waves are transmitted and received using these ultrasonic sensors, and based on the time difference between the propagation time of ultrasonic waves propagating from the upstream side to the downstream side and the propagation time of ultrasonic waves propagating from the downstream side to the upstream side, The flow rate of the liquid is calculated. The flow rate measuring pipe is used in a state of being attached to the ultrasonic flow meter. For example, Patent Document 1 discloses an ultrasonic flowmeter to which a disposable flow rate measuring tube is detachably attached. Specifically, the flow rate measuring pipe has a straight pipe portion housed in the cavity of the holder, and an ultrasonic sensor similarly provided in the holder at the end of the straight pipe portion is biased by a spring force. It is designed to be pushed. The patent documents 2 to 4 do not disclose any structure for making the flow rate measuring pipe detachable.

U.S. Pat. No. 5,463,906 (FIG. 1 etc.) Patent No. 5548857 gazette (figure 1 grade) JP, 2007-58352, A (Figure 1, Figure 16 grade) JP, 2008-128841, A (refer to figure 1 grade)

However, in the prior art described in Patent Document 1, when the straight pipe portion is housed in the cavity of the holder at the time of mounting the flow rate measuring pipe, it is necessary to operate and hold down the slide bar against the biasing force of the spring. There is. In addition, the operation direction of the slide bar is different from the storage direction of the straight pipe portion. That is, there is a problem that it is difficult to attach the flow rate measuring pipe, since the operation in two directions must be performed simultaneously. Further, in Patent Document 1, since the flow rate measuring pipe is exposed from the opening of the cavity, if an unintended external force acts on the infusion tube connected to both ends of the flow rate measuring pipe, the flow rate measuring pipe may fall off the holder There is also.

The present invention has been made in view of the above problems, and an object thereof is to provide an ultrasonic flowmeter capable of easily replacing a flow rate measuring pipe and preventing dropout of the flow rate measuring pipe It is about providing the usage method.

In order to solve the above problems, the invention according to claim 1 is opposed to the upstream position and the downstream position of a flow rate measuring pipe provided with a bent portion provided in the middle of a pipe through which liquid flows and bent at right angles to both ends. A pair of ultrasonic sensors arranged to alternately propagate ultrasonic waves through the flow rate measuring pipe, and an urging force for pressing the ultrasonic sensor against the bending portion on the upstream side and the downstream side of the flow rate measuring pipe And a storage case for storing the flow rate measuring pipe, the pair of ultrasonic sensors, and the biasing member, and the propagation time of ultrasonic waves transmitted and received between the pair of ultrasonic sensors. It is an ultrasonic flowmeter which measures the flow of the above-mentioned liquid based on a difference, and the above-mentioned storage case covers the circumference of the above-mentioned flow measurement pipe, and the end by the side of the entrance by the flow measurement pipe and the outlet side End exposed to the circumferential surface A measurement tube holder having a measurement tube storage portion for causing the first detection sensor to store the ultrasonic sensor on the upstream side and connected to a first end in the length direction of the measurement tube holder; And a second sensor cover that accommodates the ultrasonic sensor and is connected to a second end of the measurement pipe holder in the lengthwise direction, the first sensor cover and the second sensor cover An ultrasonic flowmeter according to the present invention is characterized in that at least one of them is detachably mounted to the measurement pipe holder.

Therefore, according to the invention described in claim 1, the flow rate measuring pipe is moved along the length direction of the measuring pipe holder, and the flow rate into the measuring pipe storage portion from the first end side or the second end side of the measuring pipe holder After storing the measuring pipe, the flow rate measuring pipe can be fixed by moving the first sensor cover and the second sensor cover in the same length direction and connecting them to the measuring pipe holder. That is, since the storage of the flow rate measuring pipe and the connection of the sensor cover are completed only by performing the operation in one direction, it is possible to easily attach the flow rate measuring pipe and, consequently, replace the flow rate measuring pipe. In addition, since the circumference of the flow rate measurement pipe is covered by the measurement pipe holder, for example, even if an unintended external force acts on the end on the inlet side or the end on the flow outlet side of the flow rate measurement pipe, It is possible to prevent the drop of the flow rate measuring pipe.

According to a second aspect of the present invention, in the first aspect, the flow rate measuring pipe has a straight pipe portion extended in a straight shape and has the bent portions at both ends of the straight pipe portion. The measurement pipe storage portion has a straight pipe portion storage portion for housing the straight pipe portion, and a groove portion which is in communication with the straight pipe portion storage portion and opens at the circumferential surface of the measurement pipe holder, and the first When the sensor cover detachably mounted on the measurement pipe holder among the sensor cover and the second sensor cover is separated from the measurement pipe holder, the first end side of the measurement pipe holder or the first end side of the measurement pipe holder When the straight pipe portion storage portion is opened at the second end side and the sensor cover is connected to the measurement pipe holder, the straight end is opened at the first end side or the second end side of the measurement pipe holder. The gist is that the tube storage portion is closed.

Therefore, according to the second aspect of the present invention, the flow rate measuring pipe is moved along the length direction of the measuring pipe holder, and the straight pipe portion of the flow rate measuring pipe is accommodated in the straight pipe portion storage portion and in the groove portion. After the bent portion of the flow rate measuring pipe is stored, the straight pipe portion can be fixed by connecting a sensor cover detachably mounted to the measuring pipe holder to the measuring pipe holder. In this case, simply by moving the flow measurement pipe along the length direction of the measurement pipe holder, the storage of the straight pipe portion and the storage of the bent portion are completed, so the flow measurement pipe can be attached more easily. It can be carried out.

The gist of the invention according to claim 3 is that in claim 2 the width of the groove portion is smaller than the inner diameter of the straight pipe portion storage portion.

Therefore, according to the third aspect of the present invention, the width of the groove can be made smaller than the outer diameter of the straight pipe section stored in the straight pipe section storage section. In this case, the straight pipe portion is prevented from dropping out of the straight pipe portion storage portion via the groove portion.

In the invention according to a fourth aspect, in any one of the first to third aspects, the measurement tube holder has a holder-side contact, and the first sensor cover and the second sensor cover have the same structure. The sensor cover detachably mounted on the measuring tube holder has a cover-side contact, and the sensor cover is connected to the measuring tube holder with the holder-side contact and the cover-side contact. The gist is that they are arranged to face each other when contacting each other.

Therefore, according to the invention described in claim 4, when the ultrasonic sensor housed in the sensor cover detachably mounted on the measuring tube holder is connected to the cover-side contact via the internal wiring, It is possible to prevent the exposure of the internal wiring to the outside of the sensor cover. Therefore, it is possible to solve the problem that the tube is caught in the internal wiring.

In the invention according to claim 5, according to any one of claims 1 to 4, the sensor cover on the side of the first sensor cover and the second sensor cover on which the biasing member is not accommodated is The gist of the present invention is that it is detachably mounted to the measurement pipe holder.

Therefore, according to the fifth aspect of the present invention, the sensor cover that is attached to and detached from the measurement pipe holder is reduced in weight because it has a simple structure in which the biasing member is not accommodated. As a result, the usability of the ultrasonic flowmeter is improved.

The invention according to claim 6 is characterized in that, in claim 1, both of the first sensor cover and the second sensor cover are detachably attached to the measurement pipe holder. .

Therefore, according to the invention of claim 6, even when the first sensor cover is removed or the second sensor cover is removed, the flow rate measuring pipe is replaced. Since it can be used, the usability of the ultrasonic flowmeter is further improved.

The gist of the invention according to claim 7 is that in any one of claims 1 to 6, the measuring tube holder is formed of a transparent material.

Therefore, according to the seventh aspect of the present invention, when the flow rate measuring pipe is stored in the measurement pipe storage portion of the measurement pipe holder, it is easy to check the state of the liquid flowing in the flow rate measuring pipe. Here, as a transparent material for forming the measuring tube holder, resin materials such as ABS resin (acrylonitrile butadiene styrene resin), PC resin (polycarbonate resin), PET resin (polyethylene terephthalate resin) can be used.

The invention according to claim 8 is the sensor according to any one of claims 1 to 7, wherein one of the first sensor cover and the second sensor cover is detachably attached to the measurement pipe holder. The gist of the present invention is that the cover is a screw cap that is coupled to the measurement pipe holder by rotating.

Therefore, according to the invention described in claim 8, since the sensor cover detachably mounted on the measuring pipe holder is a screw cap, the connection strength between the measuring pipe holder and the sensor cover is improved. In addition, a connecting member such as a screw used for connecting the measurement pipe holder and the sensor cover is not necessary. Therefore, the connection structure having high strength can be realized at low cost.

In the invention according to a ninth aspect, in any one of the first to eighth aspects, the first sensor cover or the second sensor cover is provided with a display device for displaying the flow rate of the liquid. Make it a gist.

Therefore, according to the ninth aspect of the present invention, the operator can confirm whether the flow rate of the liquid is abnormal or not by confirming the display on the display device.

The gist of the invention according to a tenth aspect is that, in any one of the first to ninth aspects, the flow rate measuring pipe is provided in the middle of an infusion tube through which an infusion as the liquid flows.

Therefore, according to the invention of claim 10, since the flow rate measuring pipe is provided in the middle of the infusion tube for flowing the infusion, ultrasonic waves are efficiently propagated from the ultrasonic sensor into the infusion through the flow rate measuring pipe. The ultrasonic measurement such as the flow rate measurement of the infusion can be performed reliably. In addition, since the infusion tube is thin, it is possible to form a thin flow rate measuring tube. In this case, for example, since a small sensor having a diameter of 15 mm or less can be used as the ultrasonic sensor, the ultrasonic flowmeter can be formed compact.

The invention according to claim 11 is a method of using the ultrasonic flowmeter according to claim 1, wherein both of the first sensor cover and the second sensor cover are attached to and removed from the measurement pipe holder. And a plurality of different types of measurement pipe holders, which are mounted according to the shape and size of the flow measurement pipe, are prepared in advance, and one of the measurement pipe holders is selected according to the shape and size of the flow measurement pipe. A preparation selection step of selecting a holder, and the flow rate measurement pipe provided in the middle of the pipe with respect to the selected measurement pipe holder, and the first sensor cover and the second sensor The gist of the present invention is a method of using an ultrasonic flowmeter comprising: an assembling step of connecting a cover; and a measuring step of measuring a flow rate after the assembling step.

Therefore, according to the invention of claim 11, in the assembling step, the flow rate measurement pipe is moved along the length direction of the measurement pipe holder, and the flow rate measurement pipe is accommodated in the measurement pipe holder, The flow rate measuring pipe can be fixed by moving the first sensor cover and the second sensor cover in the same longitudinal direction and connecting them to the measuring pipe holder. That is, since the storage of the flow rate measuring pipe and the connection of the sensor cover are completed only by performing the operation in one direction, it is possible to easily attach the flow rate measuring pipe and, consequently, replace the flow rate measuring pipe. Moreover, since the surroundings of the flow rate measurement pipe are covered by storing the flow rate measurement pipe in the measurement pipe holder, for example, even if an unintended external force acts on the pipe provided with the flow rate measurement pipe, the flow rate measurement from the measurement pipe holder It is possible to prevent the tube from falling off.

Moreover, in the preparation and selection step, a plurality of different types of measurement pipe holders are prepared in advance according to the shape and size of the flow rate measurement pipe, and among them, one measurement pipe holder according to the shape and size of the flow rate measurement pipe The desired flow rate measuring tube can be easily fitted to select the In addition, when replacing the flow rate measuring tube, only the measuring tube holder is replaced, and the first sensor cover and the second sensor cover are used as they are, reducing parts cost compared to replacing the entire storage case. can do.

As described above in detail, according to the invention described in claims 1 to 11, it is possible to easily replace the flow rate measuring pipe, and to prevent the drop of the flow rate measuring pipe, and an ultrasonic flowmeter How to use can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which shows the infusion system of 1st Embodiment. The perspective view which shows an ultrasonic flowmeter. Sectional drawing which shows an ultrasonic flowmeter. The disassembled perspective view which shows an ultrasonic flowmeter. The block diagram which shows the electric constitution of the infusion system. The perspective view which shows the ultrasonic flowmeter of 2nd Embodiment. Sectional drawing which shows an ultrasonic flowmeter. The disassembled perspective view which shows the structure of 1st sensor cover vicinity of a storage case. The principal part sectional view showing the ultrasonic flowmeter of other embodiments. The front view which shows the flow measurement pipe | tube of other embodiment. The perspective view which shows the ultrasonic flowmeter of other embodiment. The perspective view which shows the ultrasonic flowmeter of other embodiment. The schematic block diagram which shows the infusion system of other embodiment. (A), (b) is a front view which shows the measurement pipe holder and flow rate measurement pipe | tube of other embodiment.

First Embodiment
Hereinafter, a first embodiment in which the present invention is embodied in an infusion system will be described in detail based on the drawings.

As shown in FIG. 1, the infusion system 1 of the present embodiment includes an infusion tube 2 which is a tube through which an infusion W1 (a liquid such as a drug solution) flows. The infusion tube 2 is a flexible transparent tube, and its outer diameter is, for example, about 3 mm. In addition, the infusion tube 2 is connected at its proximal end to the infusion bag 3 and at its distal end to the syringe 4. Therefore, the infusion W1 is administered from the infusion tube 2 to the vein or the like of the patient 5 through the syringe 4. In addition, as a formation material of the infusion tube 2, BDR resin (polybutadiene resin), PU resin (polyurethane resin), PO resin (polyolefin resin), PTFE resin (polytetrafluoroethylene resin), silicone rubber etc. can be used. .

Furthermore, a clamp 6 (adjustment knob) is installed in the middle of the infusion tube 2. The clamp 6 has a roller (not shown) slidably provided in the axial direction of the infusion tube 2. The clamp 6 is configured to switch the flow passage in the infusion tube 2 between the closed state and the open state by operating the roller. Further, the clamp 6 is configured to be capable of adjusting the flow rate and the flow rate of the infusion solution W1 in accordance with the operation amount of the roller in the open state. Furthermore, at a position between the infusion bag 3 and the clamp 6 in the infusion tube 2, a pump device 7 (a liquid feeding means) for delivering the infusion W1 in the infusion bag 3 toward the tip of the infusion tube 2 is installed There is.

And, in the middle of the infusion tube 2, specifically speaking, a flow rate measuring tube 11 is provided at a position between the infusion bag 3 and the pump device 7 in the infusion tube 2. The flow rate measurement pipe 11 of the present embodiment is formed using, for example, a transparent resin material such as polycarbonate resin. As shown in FIGS. 2 to 4, an upstream portion (portion on the infusion bag 3 side) of the infusion tube 2 is connected to an end of the flow rate measuring tube 11 on the inlet 12 (see FIG. 3) side, A downstream portion (a portion on the side of the pump device 7) of the infusion tube 2 is connected to an end of the flow rate measuring pipe 11 on the side of the outlet 13 (see FIGS. 2 and 3). In the flow rate measuring pipe 11 of this embodiment, the infusion W1 flows from the inflow port 12 toward the outflow port 13.

Further, the flow rate measurement pipe 11 has a straight pipe portion 14 extended in a straight shape, and has bending portions 15 and 16 at both ends of the straight pipe portion 14 respectively. The upstream bent portion 15 is connected to the upstream end of the straight pipe portion 14 and has a shape bent at a right angle to the straight pipe portion 14 and has an inlet 12 at the tip. The downstream bent portion 16 is connected to the downstream end of the straight pipe portion 14 and has a shape bent at a right angle to the straight pipe portion 14 and has an outlet 13 at its tip. The flow rate measuring pipe 11 of the present embodiment has a shape (crank shape) in which the upstream bent portion 15 and the downstream bent portion 16 are bent in opposite directions via the straight pipe portion 14.

As shown in FIG. 1, at a position between the infusion bag 3 and the pump device 7 in the infusion tube 2, an ultrasonic flowmeter 20 in which a flow rate measuring tube 11 is accommodated is installed. The ultrasonic flowmeter 20 is for measuring the flow rate of the infusion fluid W1 flowing through the infusion tube 2, for example, at a medical site by the ultrasonic wave propagation time difference method.

As shown in FIGS. 3 and 4, the ultrasonic flow meter 20 includes a pair of ultrasonic sensors 21 and 22. The two ultrasonic sensors 21 and 22 are disposed opposite to each other via the straight pipe portion 14 of the flow rate measuring pipe 11. Specifically, the first ultrasonic sensor 21 is provided at the upstream position of the straight pipe portion 14, and the second ultrasonic sensor 22 is provided at the downstream position of the straight pipe portion 14. Both ultrasonic sensors 21 and 22 are sensors having the same structure. Specifically, the ultrasonic sensors 21 and 22 are small sensors having a diameter of 10 mm, and have a convex curved ultrasonic radiation surface 23 at the tip. The ultrasonic sensors 21 and 22 are a cap-like sensor case 25 having a flange portion 24 at its base end, and an ultrasonic transducer (not shown) which is built in the sensor case 25 and capable of transmitting and receiving ultrasonic waves. Is equipped. The ultrasonic transducer is, for example, a piezoelectric element formed in a disk shape, a rectangular plate shape, or the like using a piezoelectric ceramic such as lead zirconate titanate (PZT).

The sensor case 25 has the vibrating surface of the ultrasonic transducer adhered to the inner surface of the tip, so the outer surface of the tip becomes the ultrasonic radiation surface 23. Further, the outer side surface of the tip portion of the sensor case 25 is covered with a rubber sheet 26. Therefore, in a state where the ultrasonic radiation surface 23 is pressed against the proximal end portion of the bending portion 15 of the flow rate measuring tube 11 through the rubber sheet 26, the first ultrasonic sensor 21 transmits ultrasonic waves from the ultrasonic radiation surface 23 Will radiate. Similarly, with the second ultrasonic sensor 22 pressing the ultrasonic radiation surface 23 against the proximal end portion of the bending portion 16 of the flow rate measuring tube 11 via the rubber sheet 26, the second ultrasonic sensor 22 It emits sound waves. Further, two internal wires 27a are connected to the ultrasonic transducer of the first ultrasonic sensor 21, and two internal wires (not shown) are connected to the ultrasonic transducer of the second ultrasonic sensor 22. It is connected. The internal wiring 27 a connected to the ultrasonic transducer of the first ultrasonic sensor 21 is drawn out from the center of the outer surface of the proximal end of the sensor case 25. Further, the internal wiring connected to the ultrasonic transducer of the second ultrasonic sensor 22 is drawn out from the center of the outer surface of the proximal end of the sensor case 25 and is bundled by the wiring tube 28.

As shown in FIGS. 3 and 4, the ultrasonic flowmeter 20 includes a spring unit 31 (biasing member). The spring unit 31 presses the ultrasonic radiation surface 23 of the first ultrasonic sensor 21 against the bending portion 15 on the upstream side, and the ultrasonic radiation surface 23 of the second ultrasonic sensor 22 on the bending portion 16 on the downstream side. It is designed to apply a biasing force to press it. The spring unit 31 further includes a compression spring 32, a cap 33, a pressure adjustment screw 34, and the like. The cap 33 has a substantially cylindrical shape, and has a convex portion 35 on the inner surface side (upper surface side in FIG. 3). Further, a spring receiving hole 36 for receiving the base end of the compression spring 32 is formed in the cap 33 so as to pass therethrough. The spring receiving hole 36 extends in the axial direction at the center of the cap 33. Further, a pressure adjustment screw 34 is screwed into the spring accommodation hole 36. The pressure adjustment screw 34 has a function of pressing the compression spring 32 from the proximal end side via an annular spacer 37 (copper plate). By changing the screwing amount of the pressure adjusting screw 34, the pressing amount for pressing the compression spring 32 is adjusted. Further, a through hole 34 a extending in the axial direction of the pressure adjusting screw 34 is provided at the central portion of the pressure adjusting screw 34. On the other hand, the tip of the compression spring 32 is in contact with the second sensor fixing member 69 via the annular spacer 38 (copper plate), and the biasing force of the compression spring 32 is via the second sensor fixing member 69. It acts on the second ultrasonic sensor 22.

As shown in FIGS. 2 to 4, the ultrasonic flowmeter 20 includes a storage case 41 for storing the flow rate measuring tube 11, the ultrasonic sensors 21 and 22, and the spring unit 31. The storage case 41 has a substantially cylindrical shape, and includes a measurement pipe holder 42, a first sensor cover 51, and a second sensor cover 61.

The measuring tube holder 42 is formed in a substantially cylindrical shape using a transparent resin material such as polycarbonate resin, for example. The measurement pipe holder 42 has a measurement pipe storage portion 43 which covers the periphery of the flow rate measurement pipe 11 and exposes the end on the flow inlet 12 side and the end on the flow outlet 13 side of the flow rate measurement pipe 11 to the outer peripheral surface 42c. ing. The measurement pipe storage portion 43 includes a straight pipe portion storage portion 44 for storing the straight pipe portion 14 of the flow rate measurement pipe 11, a groove portion 45 for storing the bent portion 15 on the upstream side of the flow rate measurement pipe 11, and And a groove 46 for receiving the bending portion 16 on the downstream side. The straight pipe portion storage portion 44 includes a small diameter portion 47 and large diameter portions 48 and 49 positioned at the upstream end and the downstream end of the small diameter portion 47, respectively. The straight pipe portion 14 is disposed in the small diameter portion 47. Further, the upstream end of the straight pipe portion 14 and the base end of the bent portion 15 are disposed in the upstream large diameter portion 48, and the proximal end of the bent portion 16 is disposed in the downstream large diameter portion 49. Department is arranged.

As shown in FIGS. 2 to 4, the grooves 45 and 46 are disposed on opposite sides of the straight pipe portion storage portion 44. Each groove 45, 46 has a U-shape that opens at the first end 42 a of the measuring tube holder 42. The groove 45 communicates with the large diameter portion 48 of the straight pipe portion storage portion 44 and is open at the outer peripheral surface 42 c of the measurement pipe holder 42. On the other hand, the groove portion 46 communicates with the entire straight pipe portion storage portion 44 and is opened at the outer peripheral surface 42 c of the measurement pipe holder 42. Therefore, the depth of the groove 46 (the length in the axial direction of the measurement tube holder 42) is larger than the depth of the groove 45. Further, the widths of the groove portions 45 and 46 are equal to each other and smaller than the inner diameter of the straight pipe portion storage portion 44.

As shown in FIGS. 3 and 4, a pair of communication holes 71 communicating the first end 42 a side and the second end 42 b side of the measurement pipe holder 42 is provided on the outer peripheral portion of the measurement pipe holder 42. There is. The two communication holes 71 are disposed on the opposite side to each other via the straight pipe portion storage portion 44. A holder-side contact 72 is attached to the opening on the first end 42 a side of each communication hole 71. The holder-side contact 72 is connected to one end of the internal wiring 27 b inserted in the communication hole 71.

Further, the holder side contactor 72 includes a main body portion 72a and a pin 72b which can be inserted into and withdrawn from the main body portion 72a. The pin 72b is moved in the direction of being sunk into the main body 72a (downward in FIG. 3) by contacting the cover-side contact 82 when the first sensor cover 51 is connected to the measurement tube holder 42. It has become. The pin 72b is biased by a coil spring (not shown) in the main body portion 72a by being separated from the cover-side contact 82 when the first sensor cover 51 is separated from the measurement tube holder 42, and the main body portion It is adapted to move in a direction (upward in FIG. 3) projecting from 72a.

As shown in FIGS. 2 to 4, the first sensor cover 51 accommodates the first ultrasonic sensor 21 and is connected to the first end 42 a of the measurement tube holder 42. The first sensor cover 51 is, for example, a screw cap that is formed using a resin material such as POM resin (polyacetal resin) and is coupled to the measurement tube holder 42 by rotating.

In addition, a first sensor holder 52 having a substantially cylindrical shape is attached to the first sensor cover 51. The first sensor holder 52 is provided with a storage hole 55 communicating the front end surface 53 with the rear end surface 54, and the first ultrasonic sensor 21 is stored in the storage hole 55. As shown in FIG. 3, the accommodation hole 55 is composed of a small diameter portion 56 and a large diameter portion 57 positioned closer to the rear end surface 54 than the small diameter portion 56. At a connection portion between the small diameter portion 56 and the large diameter portion 57, a step surface 58 for locking the flange portion 24 of the first ultrasonic sensor 21 is formed. A first sensor fixing member 59 having an annular shape is screwed to the large diameter portion 57 of the housing hole 55. The first sensor fixing member 59 presses the first ultrasonic sensor 21 from the proximal end side, and the distal end portion (ultrasonic radiation surface 23) of the first ultrasonic sensor 21 is made of the first sensor holder 52. It fixes in the state made to project from the front end surface 53. As shown in FIG. Further, two internal wires 27 a connected to the ultrasonic transducer of the first ultrasonic sensor 21 are inserted into the through holes 59 a of the first sensor fixing member 59.

In the state where the first ultrasonic sensor 21 is fixed to the first sensor holder 52, the screw 52b is inserted into the screw hole 52a provided in the first sensor holder 52, and the tip of the inserted screw 52b is The first sensor cover 51 is screwed (see FIG. 4). As a result, the first sensor holder 52 is attached to the first sensor cover 51.

As shown in FIGS. 3 and 4, a pair of through holes 81 extending along the axial direction of the first sensor holder 52 is provided on the outer peripheral portion of the first sensor holder 52. The two through holes 81 are disposed on opposite sides of each other through the storage hole 55. The cover-side contacts 82 are attached to the through holes 81, respectively. The cover-side contact 82 is connected to one end of the internal wiring 27 a extending from the first ultrasonic sensor 21. The cover-side contact 82 is disposed opposite to the holder-side contact 72 so as to contact the pin 72 b of the holder-side contact 72 when the first sensor cover 51 is connected to the measurement tube holder 42. There is.

As shown in FIGS. 2 to 4, the second sensor cover 61 is for housing the second ultrasonic sensor 22 and the spring unit 31. The second sensor cover 61 is formed using, for example, a resin material such as POM resin. The first end 61 a of the second sensor cover 61 is connected to the second end 42 b of the measurement pipe holder 42. Specifically, the screw 61c is inserted into a screw hole (not shown) provided in the second sensor cover 61, and the tip end of the inserted screw 61c is screwed to the measurement pipe holder 42 (see FIG. 4). . As a result, the second sensor cover 61 can be attached to the measurement pipe holder 42.

Further, a second sensor holder 62 having a substantially cylindrical shape is accommodated in the second sensor cover 61. The second sensor holder 62 is provided with a storage hole 65 communicating the front end surface 63 and the rear end surface 64, and the second ultrasonic sensor 22 is stored in the storage hole 65. As shown in FIG. 3, the housing hole 65 is composed of a small diameter portion 66 and a large diameter portion 67 located closer to the rear end surface 64 than the small diameter portion 66. At a connection portion between the small diameter portion 66 and the large diameter portion 67, a step surface 68 for locking the flange portion 24 of the second ultrasonic sensor 22 is formed. A second sensor fixing member 69 having a substantially cylindrical shape is screwed to the large diameter portion 67 of the housing hole 65. The second sensor fixing member 69 presses the second ultrasonic sensor 22 from the proximal end side, and the tip (ultrasonic radiation surface 23) of the second ultrasonic sensor 22 is a second sensor holder 62. It is fixed in the state which made it project from the front end face 63 of this. Further, the internal wiring connected to the ultrasonic transducer of the second ultrasonic sensor 22 and the wiring tube 28 are inserted into the through hole 69 a of the second sensor fixing member 69.

As shown in FIGS. 3 and 4, the second sensor cover 61 extends along the axial direction of the second sensor cover 61 and communicates with the communication hole 71 of the measurement tube holder 42. A pair of communication holes 73 is provided. The two communication holes 73 are disposed on the opposite side to each other via the storage hole 65. The internal wiring 27 b extended from the opening on the second end 42 b side of the communication hole 71 is inserted into each communication hole 73.

Further, as shown in FIGS. 2 to 4, the second end 61b side opening of the second sensor cover 61 is closed by the cap 33 of the spring unit 31 described above. Then, with the convex portion 35 fitted in the opening at the second end 61b side of the second sensor cover 61, the screw 33b is inserted through the screw hole 33a provided on the outer peripheral portion of the cap 33 and the inserted screw 33b The tip portion is screwed to the second sensor cover 61. As a result, the cap 33 is attached to the second sensor cover 61.

As shown in FIGS. 3 and 4, a pair of communication holes 74 extending along the axial direction of the cap 33 and communicating with the communication holes 73 of the second sensor cover 61 is provided on the outer peripheral portion of the cap 33. It is done. The two communication holes 74 are disposed on the opposite side to each other through the above-described spring storage holes 36. The internal wiring 27 b extended from the opening on the second end 61 b side of the communication hole 73 is inserted into each communication hole 74.

Therefore, the internal wiring 27b connected to the holder-side contact 72 described above passes through the communication hole 71 of the measurement tube holder 42, the communication hole 73 of the second sensor cover 61, and the communication hole 74 of the cap 33 in order. , And is drawn out of the ultrasonic flowmeter 20. Then, the internal wiring 27 b drawn to the outside of the ultrasonic flowmeter 20 is connected to the measurement control device 90 (see FIG. 5). Further, the internal wiring connected to the second ultrasonic sensor 22 described above is in a state of being bundled with the wiring tube 28, the through hole 69 a of the second sensor fixing member 69, the inner space of the compression spring 32, the cap 33 The spring accommodation hole 36 and the through-hole 34 a of the pressure adjustment screw 34 are sequentially inserted and drawn out of the ultrasonic flowmeter 20. The internal wiring connected to the second ultrasonic sensor 22 and drawn to the outside of the ultrasonic flowmeter 20 is connected to the measurement control device 90. The internal wiring 27b connected to the first ultrasonic sensor 21 and the internal wiring connected to the second ultrasonic sensor 22 are bound to a wiring tube (not shown) outside the ultrasonic flowmeter 20. Will be

In the present embodiment, of the two sensor covers 51 and 61 constituting the storage case 41, the first sensor cover 51 on the side where the spring unit 31 is not stored can be attached to and detached from the measurement pipe holder 42. It is attached to. More specifically, when the first sensor cover 51 is separated from the measurement tube holder 42, the first ultrasonic sensor 21 and the measurement control are separated as the cover-side contact 82 and the holder-side contact 72 are separated. An internal wire 27 connecting the device 90 is separated into an internal wire 27a and an internal wire 27b. Therefore, the first sensor cover 51 can be attached to and detached from the measurement pipe holder 42. On the other hand, the internal wiring 27 is not separated at the connection portion between the second sensor cover 61 and the measurement pipe holder 42. Therefore, the second sensor cover 61 can not be attached to and detached from the measurement pipe holder 42.

Next, the electrical configuration of the infusion system 1 will be described.

As shown in FIG. 5, the measurement control device 90 of the infusion system 1 is a device for calculating the flow rate of the infusion solution W1 according to the difference in propagation time of the ultrasonic waves transmitted and received by the ultrasonic sensors 21 and 22. . The measurement control device 90 includes a signal processing unit 91, an arithmetic processing unit 92, an input device 93, a display device 94, and the like. The signal processing unit 91 includes a circuit that outputs a drive signal for driving each of the ultrasonic sensors 21 and 22, a circuit that detects the propagation time of ultrasonic waves, and the like. The arithmetic processing unit 92 is a processing circuit configured to include the conventionally known CPU 95, memory 96, and the like. A control program and data are stored in the memory 96, and the CPU 95 performs flow rate calculation processing and display processing based on the control program stored in the memory 96.

More specifically, the signal processing unit 91 alternately propagates ultrasonic waves through the flow rate measurement tube 11 by driving the ultrasonic sensors 21 and 22. Then, the signal processing unit 91 transmits the ultrasonic wave transmitted from the first ultrasonic sensor 21 and transmitted by the second ultrasonic sensor 22 in the forward direction of the ultrasonic wave (in the same direction as the direction in which the infusion W1 flows) The ultrasonic wave propagation time is detected. Further, the signal processing unit 91 transmits the ultrasonic wave in the reverse direction of the ultrasonic wave transmitted from the second ultrasonic sensor 22 and received by the first ultrasonic sensor 21 (propagating in the direction opposite to the direction in which the infusion fluid W1 flows). Detection of the ultrasonic wave propagation time). Then, the signal processing unit 91 outputs the propagation time in the forward direction and the propagation time in the reverse direction to the arithmetic processing unit 92. The arithmetic processing unit 92 takes in the propagation time in the forward direction and the propagation time in the reverse direction output from the signal processing unit 91, and calculates the flow rate of the infusion W1 by calculation based on the difference in the propagation time.

Further, as shown in FIG. 5, the input device 93 has various operation buttons, and performs start / end of measurement, setting of a display mode, and the like. The display device 94 is, for example, a liquid crystal display, and displays the flow rate calculated by the arithmetic processing unit 92.

Next, a method of using the ultrasonic flowmeter 20 will be described.

The flow rate measurement pipe 11 attached to the ultrasonic flowmeter 20 of the present embodiment is a disposable flow rate measurement pipe, and therefore, needs to be periodically replaced. Therefore, a method of replacing the flow rate measuring pipe 11 will be described below. Specifically, first, the first sensor cover 51 is rotated counterclockwise to be separated from the measurement pipe holder 42, and the straight pipe storage portion 44 and the groove portion are formed at the first end 42a side of the measurement pipe holder 42. 45, 46 are opened. Next, the flow rate measuring pipe 11 is taken out from the inside of the measuring pipe housing part 43 of the measuring pipe holder 42. Then, after removing the infusion tube 2 from the bent portions 15 and 16 of the flow rate measuring tube 11, the removed infusion tube 2 is attached to the bent portions 15 and 16 of another flow rate measuring tube 11 prepared in advance. .

Next, an assembly process is performed, and the flow rate measurement pipe 11 in a state provided in the middle of the infusion tube 2 is accommodated in the measurement pipe holder 42, and the first sensor cover 51 is connected. Specifically, the flow rate measurement pipe 11 is moved along the axial direction (length direction) of the measurement pipe holder 42, and the flow rate measurement pipe 11 is inserted into the measurement pipe storage portion 43 from the first end 42 a side of the measurement pipe holder 42. Store the At this time, the straight pipe portion 14 is stored in the straight pipe portion storage portion 44, the bending portion 15 is stored in the groove portion 45, and the bending portion 16 is stored in the groove portion 46. Next, the first sensor cover 51 is placed in the vicinity of the opening on the first end 42 a side of the measurement tube holder 42, and in this state, the first sensor cover 51 is rotated clockwise. As a result, the first sensor cover 51 moves along the axial direction of the measurement pipe holder 42 and is connected to the measurement pipe holder 42, and the straight pipe storage portion 44 at the first end 42 a side of the measurement pipe holder 42. And the grooves 45 and 46 close. At this point, the replacement of the flow rate measuring pipe 11 is completed.

In the measurement process after the assembly process, flow rate measurement is performed. Specifically, the signal processing unit 91 transmits the ultrasonic wave in the positive direction (positive with respect to the flow of the infusion solution W1) transmitted from the first ultrasonic sensor 21 and received by the second ultrasonic sensor 22. Measure the propagation time of ultrasonic waves propagated in the direction. In addition, the signal processing unit 91 transmits the ultrasonic wave in the reverse direction of the ultrasonic wave transmitted from the second ultrasonic sensor 22 and received by the first ultrasonic sensor 21 (propagated in the direction opposite to the flow of the infusion W1 Measure the propagation time of ultrasonic waves. Then, the arithmetic processing unit 92 calculates the flow rate of the infusion W1 based on the difference between the measured propagation time in the forward direction and the propagation time in the reverse direction, and converts the calculated flow rate of the infusion W1 to obtain an infusion. Calculate the flow rate of W1.

Then, the arithmetic processing unit 92 outputs the data of the calculated flow rate to the display device 94, and causes the display screen of the display device 94 to display the flow rate of the infusion W1. Further, the arithmetic processing unit 92 compares the calculated flow rate with the flow rate set by the input device 93, and when the flow rate is different, determines that the flow rate is abnormal and causes the display device 94 to display an abnormality. Do.

Therefore, according to this embodiment, the following effects can be obtained.

(1) In the ultrasonic flowmeter 20 of the present embodiment, the flow rate measuring pipe 11 is moved along the axial direction of the measuring pipe holder 42, and the inside of the measuring pipe storage portion 43 from the first end 42 a side of the measuring pipe holder 42 The flow rate measuring pipe 11 is housed in the Then, the flow rate measuring pipe 11 can be fixed by moving the first sensor cover 51 along the axial direction of the measuring pipe holder 42 and connecting it to the measuring pipe holder 42. That is, since the storage of the flow rate measuring tube 11 and the connection of the first sensor cover 51 are completed only by performing the operation in one direction (the axial direction of the measuring tube holder 42), the flow rate measuring tube 11 is attached. The flow rate measuring tube 11 can be easily replaced. Further, in the present embodiment, the periphery of the flow rate measurement pipe 11 is covered by the measurement pipe holder 42. Therefore, for example, even if the infusion tube 2 is pulled or the like and an unintended external force acts on the end on the inflow port 12 side or the end on the outflow port 13 side of the flow rate measuring pipe 11, from the measuring pipe holder 42 Falling off of the flow rate measuring pipe 11 can be prevented.

(2) By the way, in the ultrasonic flowmeter described in Patent Document 1, since the slide bar is provided so as to protrude from the holder, the infusion tube may be caught on the slide bar. On the other hand, in the ultrasonic flowmeter 20 of the present embodiment, since a projection like a slide bar does not exist, the problem that the infusion tube 2 is caught in the ultrasonic flowmeter 20 hardly occurs.

(3) In the present embodiment, the ultrasonic radiation surface 23 of the first ultrasonic sensor 21 is pressed against the bending portion 15 on the upstream side of the flow rate measuring tube 11 by the biasing force of the spring unit 31, and The ultrasonic radiation surface 23 of the ultrasonic sensor 22 is pressed against the bending portion 16 on the downstream side of the flow rate measuring tube 11. As a result, the flow rate measuring pipe 11 is clamped by the ultrasonic sensors 21 and 22. Further, the ultrasonic radiation surfaces 23 of the ultrasonic sensors 21 and 22 are in close contact with the flow rate measuring pipe 11 via the rubber sheet 26. For this reason, an ultrasonic wave can be efficiently propagated from the ultrasonic radiation surface 23 of the ultrasonic sensors 21 and 22 into the infusion fluid W1 in the flow rate measuring tube 11, and the flow rate measurement of the infusion fluid W1 can be reliably performed.

(4) In the present embodiment, the internal wiring 27 a connecting the first ultrasonic sensor 21 and the cover-side contact 82 is not exposed to the outside of the storage case 41. Further, the internal wire 27 b connecting the holder side contact 72 and the measurement control device 90 is drawn out of the storage case 41 from the communication hole 74 of the cap 33 and is not exposed to the outer peripheral side of the storage case 41 There is. As a result, since it becomes difficult for the infusion tube 2 to be caught by the internal wire 27 connecting the first ultrasonic sensor 21 and the measurement control device 90, for example, there is a problem that the internal wire 27 is cut when the infusion tube 2 is caught. Can be eliminated.

(5) In the present embodiment, when the measurement pipe holder 42 and the flow measurement pipe 11 are formed of a transparent material, when the flow measurement pipe 11 is stored in the measurement pipe storage portion 43 of the measurement pipe holder 42, The state of the infusion W1 flowing in the flow rate measuring pipe 11 can be confirmed.

(6) In the present embodiment, the flow rate measuring pipe 11 is provided in the middle of the infusion tube 2 through which the infusion W1 flows. In addition, since the infusion tube 2 is thin (the outer diameter is about 3 mm), the flow rate measuring tube 11 connected thereto can be formed thin. As a result, since a small size sensor with a diameter of 10 mm can be used as the ultrasonic sensors 21 and 22 pressed against the flow rate measuring pipe 11, the ultrasonic flowmeter 20 can be made compact.

Second Embodiment
Hereinafter, a second embodiment of the present invention will be described based on the drawings. Here, parts different from the first embodiment will be mainly described. In the present embodiment, the arrangement of the internal wiring connected to the first ultrasonic sensor 21 is different from that of the first embodiment.

More specifically, as shown in FIGS. 6-8, in the ultrasonic flowmeter 100 of the present embodiment, two internal wires (not shown) are connected to the ultrasonic transducer of the first ultrasonic sensor 21. Both internal wires are bundled by the wiring tube 101. Further, a through hole 103 a extending in the axial direction of the first sensor cover 103 is provided at a central portion of the first sensor cover 103 constituting the storage case 102.

The internal wiring connected to the first ultrasonic sensor 21 is in a state of being bundled with the wiring tube 101, and the through hole 59a of the first sensor fixing member 59 and the through hole of the first sensor cover 103 The electrodes 103 a are sequentially inserted and drawn out of the ultrasonic flowmeter 100. Then, the internal wiring connected to the first ultrasonic sensor 21 and drawn to the outside of the ultrasonic flowmeter 100 is connected to the measurement control device 90 (see FIG. 5).

Therefore, according to the present embodiment, the components such as the holder-side contactor 72 and the cover-side contactor 82 of the first embodiment become unnecessary, so that the component cost of the ultrasonic flowmeter 100 can be suppressed.

The above embodiments may be modified as follows.

In the first embodiment, of the first sensor cover 51 and the second sensor cover 61, the first sensor cover 51, which is the sensor cover on the side where the spring unit 31 is not accommodated, is the measurement tube holder 42. It was mounted to be removable. However, the second sensor cover 61, which is a sensor cover on the side where the spring unit 31 is stored, may be detachably mounted to the measurement pipe holder 42. Further, both of the first sensor cover 51 and the second sensor cover 61 may be detachably attached to the measurement pipe holder 42.

When the first sensor cover 51 is detachably attached to the measurement pipe holder 42, the first end 42a of the measurement pipe holder 42 when the first sensor cover 51 is separated from the measurement pipe holder 42. The straight pipe portion storage portion 44 and the groove portions 45 and 46 are opened at the side. Then, when the first sensor cover 51 is connected to the measurement pipe holder 42, the straight pipe storage portion 44 and the groove portions 45 and 46 are closed at the first end 42a side of the measurement pipe holder 42. On the other hand, when the second sensor cover 61 is detachably attached to the measurement pipe holder 42, when the second sensor cover 61 is separated from the measurement pipe holder 42, the second of the measurement pipe holder 42 is When the straight pipe portion storage portion and the groove portion are opened at the end 42 b side and the second sensor cover 61 is connected to the measurement pipe holder 42, the straight pipe portion storage portion at the second end 42 b side of the measurement pipe holder 42 And the groove closes.

In the first embodiment, the sensor cover (first sensor cover 51) detachably mounted on the measurement pipe holder 42 is a screw cap connected to the measurement pipe holder 42 by rotating it. there were. However, the sensor cover detachably attached to the measurement pipe holder 42 may be connected to the measurement pipe holder 42 using an adhesive or a screw, or the first end of the measurement pipe holder 42 It may be fitted in 42a or the 2nd end 42b. Also, as shown in FIG. 9, the first sensor cover 171 may be a union screw cap having a union nut 172. In this case, the first sensor cover 171 is connected to the measurement pipe holder 173 by rotating the union nut 172 and screwing it to the measurement pipe holder 173. In this way, the first sensor cover 171 and the first sensor holder 174 fixed to the first sensor cover 171 do not rotate at the time of connection to the measurement pipe holder 173. As a result, the rubber sheet 176 covering the first ultrasonic sensor 175 held by the first sensor holder 174 is distorted, and the cover side contactor 177 also held by the first sensor holder 174 is displaced. It becomes difficult to cause problems such as

The flow rate measuring pipe 11 in each of the above embodiments has a shape (crank shape) in which the bending portion 15 on the upstream side and the bending portion 16 on the downstream side are bent at right angles in opposite directions via the straight pipe portion 14 However, it is not limited to this. Specifically, as shown in FIG. 10, in the flow rate measuring pipe 111, the upstream side bent portion 112 and the downstream side bent portion 113 are in a shape (U-shape) in which they are bent in the same direction. It is also good. Further, the flow rate measuring pipe may have a shape (Z shape) in which the upstream side bent portion and the downstream side bent portion are bent at an acute angle in opposite directions with each other via the straight pipe portion.

The storage case 41 of each of the above embodiments has a cylindrical shape, but may have another cylindrical shape such as an elliptical cylindrical shape or a rectangular cylindrical shape. In addition, the storage case may have a columnar shape such as a cylindrical shape or a square pillar shape. In addition, when a storage case makes a columnar shape, a measurement pipe | tube storage part is notched and formed, for example in a measurement pipe holder.

In each of the above embodiments, the measurement control device 90 is provided with the display device 94 for displaying the flow rate of the infusion W1. However, the display device may be provided on the ultrasonic flow meter, specifically, the first sensor cover that constitutes the ultrasonic flow meter. Further, as shown in FIG. 11, the display device 122 may be provided on the second sensor cover 121 that constitutes the ultrasonic flowmeter 120. Furthermore, as shown in FIG. 12, the ultrasonic flowmeter 130 may be attached to a drip stand (Gartor base) (not shown) via a clip 132 extending from the second sensor cover 131. In the second sensor cover 131, a display device 133 is provided, and in the flow rate measuring pipe 134 stored in the ultrasonic flowmeter 130, the upstream bending portion 135 and the downstream bending portion 136 are in the same direction. It has a curved shape (U-shaped). Further, as shown in FIG. 13, even if the ultrasonic flowmeter 140 is connected to the electrical unit 142 having the display device 141 via the flexible cable 143 and the electrical unit 142 is attached to the drip stand 144 Good.

In each of the above embodiments, a plurality of different measurement pipe holders are prepared in advance according to the shape and size of the flow rate measurement pipe, and among them, one measurement pipe holder according to the shape and size of the flow rate measurement pipe The flow rate measuring tube may be replaced by selecting. Here, as a measurement pipe holder, measurement pipe holder 42 used in the above-mentioned each embodiment, measurement pipe holders 151, 161 shown in Drawing 14 (a) and (b), etc. can be mentioned. In the measurement pipe holder 151, a flow rate measuring pipe 154 having a shape (U-shape) in which the bending portion 152 on the upstream side and the bending portion 153 on the downstream side are bent in the same direction is accommodated. Further, a flow rate measuring pipe 163 having a straight pipe portion 162 longer than the straight pipe portion 14 of each of the above-described embodiments is accommodated in the measurement pipe holder 161. Then, both of the first sensor cover 51 and the second sensor cover 61 are detachably attached to the selected measurement tube holder.

The method of replacing the flow rate measuring pipe will be described below. First, after the first sensor cover 51 and the second sensor cover 61 are removed, the flow rate measurement pipe 11 is taken out from the measurement pipe holder 42. Next, the preparation and selection process is performed, and one measurement pipe holder is selected from the three types of measurement pipe holders 42, 151, and 161 prepared in advance. In the subsequent assembly process, a flow rate measurement pipe corresponding to the selected measurement pipe holder is accommodated in the state where the infusion tube 2 is connected to the selected measurement pipe holder, and the first sensor cover 51 and the second sensor cover 61 are Concatenate. At this point, replacement of the flow rate measurement pipe is completed. Thereafter, flow rate measurement is performed in the measurement process.

In this case, when replacing the flow rate measuring tube 11, only the measuring tube holder 42 (and the flow rate measuring tube 11) is replaced, and the first sensor cover 51 and the second sensor cover 61 can be used as they are. Parts cost can be reduced as compared with the case where the entire case 41 is replaced. Incidentally, in the ultrasonic flowmeter described in Patent Document 1, when trying to mount flow measuring tubes having different shapes and sizes to the holder, it is necessary to change the design of the holder according to the opening direction of the inlet and the outlet. Therefore, the mounting portion of the flow rate measuring pipe can not be used as it is. In this case, there is a problem that the cost of parts increases.

The ultrasonic flowmeters 20 and 100 of the above embodiments are configured to measure the flow rate of the infusion W1 flowing through the flow rate measurement pipe 11 using the ultrasonic sensors 21 and 22. However, in addition to the function of detecting the flow rate of the infusion W1, the ultrasonic flow meter 20, 100 may further have the function of detecting air bubbles mixed in the infusion W1. More specifically, when air bubbles are mixed in the infusion solution W1, the sensitivity of the received signal of the ultrasonic wave received by the ultrasonic sensors 21 and 22 is reduced. Therefore, the measurement control device 90 detects air bubbles mixed in the infusion solution W1 based on the decrease in the sensitivity of the received signal. In this way, the installation space of the ultrasonic sensor can be reduced compared to the case where ultrasonic sensors are separately provided for flow measurement and air bubble detection, and the ultrasonic flowmeters 20 and 100 can be miniaturized. It becomes possible. Furthermore, since circuit components such as the signal processing unit 91 and the arithmetic processing unit 92 can be shared, the component cost of the measurement control device 90 can be suppressed.

The ultrasonic flowmeters 20 and 100 of the above embodiments are configured to measure the flow rate of the infusion W1 flowing through the flow rate measurement pipe 11 using the ultrasonic sensors 21 and 22. However, in addition to the function of detecting the flow rate of the infusion W1, the ultrasonic flow meter 20, 100 may further have the function of measuring the concentration of the infusion W1. In this way, the installation space of the ultrasonic sensor can be reduced compared to the case where ultrasonic sensors are separately provided for flow measurement and concentration measurement, and the ultrasonic flowmeters 20 and 100 can be miniaturized. It becomes possible. Furthermore, since circuit components such as the signal processing unit 91 and the arithmetic processing unit 92 can be shared, the component cost of the measurement control device 90 can be suppressed.

In each of the above embodiments, the ultrasonic flowmeter 20 is installed at a position between the infusion bag 3 and the pump device 7 in the infusion tube 2. However, between the pump device 7 and the clamp 6 in the infusion tube 2 The ultrasonic flowmeter 20 may be installed at the position of.

Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiments described above will be listed below.

(1) In any one of claims 1 to 10, the bent portions on the upstream side and the downstream side of the flow rate measuring pipe have shapes which are bent in the same direction or in the opposite direction to each other. Ultrasonic flow meter.

(2) In any one of claims 1 to 10, the ultrasonic flowmeter has a function of detecting air bubbles mixed in the liquid based on a reception signal of ultrasonic waves received by the ultrasonic sensor. The ultrasonic flowmeter characterized by further having.

(3) The ultrasonic flowmeter according to any one of claims 1 to 10, characterized in that the ultrasonic flowmeter further has a function of measuring the concentration of the liquid.

(4) The infusion tube through which the fluid, which is a liquid, flows has flexibility, and the infusion bag is connected to the proximal end, and a control knob is installed in the middle of the infusion tube, the infusion bag in the infusion tube A liquid transfer means for discharging the infusion solution in the infusion bag toward the tip of the infusion tube at a position between the control knob and the adjustment knob, and the infusion bag in the infusion tube and the fluid delivery means The ultrasonic flowmeter according to any one of claims 1 to 10, wherein the ultrasonic flowmeter according to any one of claims 1 to 10 is installed at a position between them or at a position between the liquid feeding means and the adjustment knob in the infusion tube. Infusion system.

2 Infusion tube 11, 111, 134, 154, 163 as a tube, flow rate measuring tube 12, inflow port 13, inflow port 14, 162, straight port portion 15, 16, 112, 113, 135, 136, 152, 153 ... bent portion 20, 100, 120, 130, 140 ... ultrasonic flowmeter 21, 175 ... first ultrasonic sensor 22 as an ultrasonic sensor ... second ultrasonic sensor 31 as an ultrasonic sensor ... urging member As a spring unit 41, 102 ... storage case 42, 151, 161, 173 ... measurement tube holder 42a ... first end 42b ... second end 42c ... outer peripheral surface 43 as circumferential surface ... measurement tube storage part 44 ... straight pipe part Storage part 45, 46 ... groove part 51, 103, 171 ... first sensor cover 61, 121, 131 ... second sensor cover 72 ... holder side contact 82, 177 ... cover side contact 1 2,133,141 ... infusion as a display device W1 ... liquid

Claims (11)

1. It is disposed opposite to the upstream position and the downstream position of the flow rate measuring pipe provided with a bent portion which is provided in the middle of the pipe through which the liquid flows and bent at both ends perpendicularly, and propagates ultrasonic waves alternately through the flow rate measuring pipe A pair of ultrasonic sensors,
   A biasing member for applying a biasing force for pressing the ultrasonic sensor to the bent portion on the upstream side and the downstream side of the flow rate measuring pipe;
   And a storage case for storing the flow rate measuring pipe, the pair of ultrasonic sensors, and the biasing member, and the liquid is selected based on a difference in propagation time of ultrasonic waves transmitted and received between the pair of ultrasonic sensors. An ultrasonic flowmeter that measures the flow rate,
   The storage case covers the periphery of the flow rate measurement pipe and has a measurement pipe holder having a measurement pipe storage portion that exposes the end on the inlet side and the end on the flow outlet side of the flow measurement pipe on the circumferential surface; And a first sensor cover connected to the first end of the measuring tube holder in the lengthwise direction of the measuring tube holder, and a downstream ultrasonic sensor, the length of the measuring tube holder A second sensor cover connected to the second end in the longitudinal direction,
   An ultrasonic flowmeter characterized in that at least one of the first sensor cover and the second sensor cover is detachably mounted to the measurement pipe holder.
2. The flow rate measuring pipe has a straight pipe portion extended in a straight shape and has the bent portions at both ends of the straight pipe portion,
   The measurement pipe storage portion has a straight pipe portion storage portion for housing the straight pipe portion, and a groove portion which is in communication with the straight pipe portion storage portion and opens at the circumferential surface of the measurement pipe holder.
   The first end of the measurement pipe holder when the sensor cover removably mounted on the measurement pipe holder among the first sensor cover and the second sensor cover is separated from the measurement pipe holder The straight pipe storage portion opens at the side or the second end side,
   The straight pipe storage portion is closed at the first end or the second end of the measurement pipe holder when the sensor cover is connected to the measurement pipe holder. Ultrasonic flowmeter as described.
3. The ultrasonic flowmeter according to claim 2, wherein a width of the groove is smaller than an inner diameter of the straight pipe portion storage portion.
4. The measurement tube holder has a holder side contact, and
   Among the first sensor cover and the second sensor cover, the sensor cover detachably mounted on the measurement tube holder has a cover-side contact.
   The holder side contactor and the cover side contactor are disposed to face each other so that the sensor cover contacts each other when the sensor cover is connected to the measurement pipe holder. The ultrasonic flowmeter as described in a term.
5. The sensor cover on the side where the biasing member is not stored among the first sensor cover and the second sensor cover is detachably mounted to the measurement pipe holder. The ultrasonic flowmeter according to any one of 1 to 4.
6. The ultrasonic flowmeter according to claim 1, wherein both the first sensor cover and the second sensor cover are detachably mounted to the measurement pipe holder.
7. The ultrasonic flowmeter according to any one of claims 1 to 6, wherein the measuring tube holder is formed of a transparent material.
8. Among the first sensor cover and the second sensor cover, the sensor cover detachably mounted on the measurement pipe holder is a screw cap connected to the measurement pipe holder by rotating it. The ultrasonic flowmeter according to any one of claims 1 to 7, characterized in that:
9. The ultrasonic flow rate according to any one of claims 1 to 8, wherein a display device for displaying the flow rate of the liquid is provided on the first sensor cover or the second sensor cover. Total.
10. The ultrasonic flowmeter according to any one of claims 1 to 9, wherein the flow rate measuring pipe is provided in the middle of an infusion tube through which an infusion as the liquid flows.
11. A method of using the ultrasonic flowmeter according to claim 1, wherein
    Both the first sensor cover and the second sensor cover are detachably mounted on the measurement pipe holder.
    A plurality of different types of measurement tube holders are prepared in advance according to the shape and size of the flow rate measurement tube, and a preparation of selecting one measurement tube holder from them according to the shape and size of the flow rate measurement tube Selection process,
    An assembly process for accommodating the flow rate measurement pipe in a state provided in the middle of the pipe and connecting the first sensor cover and the second sensor cover to the selected measurement pipe holder;
    A method of using an ultrasonic flowmeter comprising the step of measuring the flow rate after the assembly step.

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