Clamp-on type ultrasonic flowmeter

Abstract

To provide a clamp-on type ultrasonic flowmeter which can be easily attached to a pipe in a narrow working space.SOLUTION: A clamp-on type ultrasonic flowmeter 1 for measuring a flow rate of a fluid flowing in a pipe using an ultrasonic wave includes a main-body-side pipe mounting portion 30 for mounting, on a pipe 100, a device main body 10 on which an ultrasonic transducer for transmitting and receiving an ultrasonic wave to and from the pipe 100 is mounted, and an outer pipe mounting portion 20 disposed to face the main-body-side pipe mounting portion 30 via the pipe 100. The band 45 inserted through the two band openings 40 is fastened to fix the body-side pipe mounting part 30 and the outside pipe mounting part 20 to the pipe 100.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a clamp-on ultrasonic flowmeter that uses ultrasonic waves to measure the flow rate of a fluid flowing in a pipe. [Background technology]

[0002] Conventionally, ultrasonic flowmeters that use ultrasonic waves to measure the flow rate of a fluid flowing through a pipe are known. In these ultrasonic flowmeters, ultrasonic waves are transmitted and received between a piezoelectric element provided on the upstream side of the pipe and a piezoelectric element provided on the downstream side of the pipe, and the flow rate of the fluid flowing through the pipe is measured from the difference in propagation time.

[0003] An oblique incidence ultrasonic flowmeter is known as this type of ultrasonic flowmeter (see, for example, Patent Document 1). In an oblique incidence ultrasonic flowmeter, ultrasonic waves are transmitted and received obliquely between one small piezoelectric element provided on the upstream side of the pipe and another small piezoelectric element provided on the downstream side of the pipe, and the flow rate of the fluid flowing through the pipe is measured from the difference in propagation time. In an oblique incidence ultrasonic flowmeter, the piezoelectric element can be attached to the pipe using a clamp-on method. The clamp-on method is a method that allows the piezoelectric element to be attached to existing pipe without cutting the pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-15090 Summary of the Invention [Problem to be solved by the invention]

[0005] In a clamp-on type ultrasonic flowmeter, when the ultrasonic transducer transmits and receives ultrasonic waves, the main body on which the ultrasonic transducer is mounted is fixed to the main body using a mounting bracket that is placed on the surface of the piping opposite to the surface on which the main body is placed, and screws are used from the outside of the mounting bracket, thereby fixing the clamp-on type ultrasonic flowmeter to the piping.

[0006] When fastening the mounting bracket to the main body with screws, the clamp-on ultrasonic flowmeter must be attached by using a screwdriver to reach around to the rear side of the main body, which makes it difficult to attach a clamp-on ultrasonic flowmeter to a pipe in a narrow working space.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a clamp-on type ultrasonic flowmeter that can be easily installed on a pipe in a place with a small working space. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the clamp-on type ultrasonic flowmeter of the present invention is a clamp-on type ultrasonic flowmeter that measures the flow rate of a fluid flowing through a pipe using ultrasonic waves, and comprises: a main body side pipe mounting part that mounts an apparatus main body, which is equipped with an ultrasonic transducer that transmits and receives ultrasonic waves to the pipe, to the pipe; and an outer pipe mounting part that is arranged opposite the main body side pipe mounting part via the pipe, and is characterized in that the main body side pipe mounting part has two band openings formed on each of both longitudinal ends of the pipe, through which bands are inserted in the circumferential direction of the pipe, and the main body side pipe mounting part and the outer pipe mounting part are fixed to the pipe by tightening the bands inserted into the two band openings.

[0009] Furthermore, in the above invention, the present invention is characterized in that steps are formed at both longitudinal ends of the pipe at the outer pipe mounting portion, and mounting protrusions that exceed the width of the band are formed from the steps toward both longitudinal ends, and the band fixes the outer pipe mounting portion to the pipe via the mounting protrusions, and the steps are formed at opposing positions corresponding to the inner end faces of the band openings to guide the band.

[0010] In the present invention, the main body side pipe mounting portion and the outer pipe mounting portion can be screwed at positions where they are arranged opposite to the pipes.

[0011] In the above invention, the band is a screw-type hose band. [Effects of the Invention]

[0012] The present invention can provide a clamp-on type ultrasonic flowmeter that can be easily attached to a pipe in a place with a small working space. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of a clamp-on type ultrasonic flowmeter according to an embodiment of the present invention. [Figure 2] FIG. 2 is a front view of the clamp-on type ultrasonic flowmeter shown in FIG. [Figure 3] 3 is a perspective view of the main body side pipe mounting portion shown in FIG. 1. FIG. [Figure 4] 4 is a perspective view of the outer pipe mounting portion shown in FIG. 1. FIG. [Figure 5] 5 is a perspective view of the main body side pipe mounting portion shown in FIG. 3 as viewed from the back side. [Figure 6] FIG. 6 is a vertical cross-sectional view of the clamp-on type ultrasonic flowmeter shown in FIG. [Figure 7] FIG. 7 is an explanatory diagram illustrating the function of the openings provided in the outer pipe mounting portion. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a clamp-on ultrasonic flowmeter according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments.

[0015] <Overall structure> FIG. 1 is a perspective view of a clamp-on type ultrasonic flowmeter 1 according to an embodiment of the present invention. FIG. 2 is a front view of the clamp-on type ultrasonic flowmeter 1 shown in FIG. 1. FIG. 3 is a perspective view of the main body-side piping attachment part 30 shown in FIG. 1. FIG. 4 is a perspective view of the outer piping attachment part 20 shown in FIG. 1. FIG. 5 is a perspective view of the main body-side piping attachment part 30 shown in FIG. 3, viewed from the rear side. FIG. 6 is a vertical cross-sectional view of the clamp-on type ultrasonic flowmeter 1 shown in FIG. 1. As shown in FIGS. 1 to 6, the clamp-on type ultrasonic flowmeter 1 clamps a piping 100, through which a fluid flows, from both sides by the main body-side piping attachment part 30 attached to the device main body 10 and the outer piping attachment part 20, and measures the flow rate of the fluid.

[0016] <Measurement function> 6, the clamp-on ultrasonic flowmeter 1 has ultrasonic transducers 5 and 6 facing each other, and the ultrasonic transducers 5 and 6 transmit ultrasonic signals to the fluid in the piping 100 and receive ultrasonic signals from the fluid in the piping 100. The ultrasonic transducers 5 and 6 have piezoelectric elements 52 and 62 attached to the inclined surfaces of wedges 51 and 61, respectively, and transmit and receive ultrasonic signals obliquely from the bottom surfaces of the wedges 51 and 61 toward the piping 100 via the acoustic coupler rubber 50.

[0017] To measure flow rate using the clamp-on ultrasonic flowmeter 1, for example, while the pipe 100 is clamped, the ultrasonic transducer 5 transmits an ultrasonic signal L1, the ultrasonic transducer 6 receives the ultrasonic signal L1 reflected by the pipe 100, and measures the propagation time of the ultrasonic signal L1. The ultrasonic transducer 6 then transmits an ultrasonic signal L2, the ultrasonic transducer 5 receives the ultrasonic signal L2 reflected by the pipe 100, and measures the propagation time of the ultrasonic signal L2. The flow rate per unit time is then calculated based on the difference in propagation time between the ultrasonic signals L1 and L2. The flow rate can also be calculated as a cumulative flow rate. At this time, the temperature measurement unit 7 attached to the device main body 10 measures the temperature of the fluid passing through the pipe 100, and temperature compensation is performed for the flow rate. The ultrasonic signals L1 and L2 are set to pass along the axis of the pipe 100.

[0018] As shown in FIG. 1, the device main body 10 includes an operation unit 2, a display unit 3, and a cable connection unit 4. The operation unit 2 is an input interface for inputting various information by selecting preset information. The display unit 3 is an output interface for outputting various information, such as displaying the flow rate (liters / min), cumulative flow rate (liters), and status (normal / abnormal). The cable connection unit 4 is a connector for connecting cables including an external power supply line and a signal line for connecting to an external device. The control unit, under instructions from the operation unit 2, controls the transmission and reception of ultrasonic transducers 5 and 6, calculates the flow velocity based on the propagation time difference and the temperature measured by the temperature measurement unit 7, and displays the results and status on the display unit 3 and outputs the results and status to the outside via the cable connection unit 4.

[0019] <Installation structure for piping> 1 and 2, the device main body 10 is fixed to the main body side pipe mounting part 30, and the clamp-on ultrasonic flowmeter 1 is attached to the pipe 100 by attaching the main body side pipe mounting part 30 and the outer pipe mounting part 20 to the pipe 100. The attachment of the main body side pipe mounting part 30 and the outer pipe mounting part 20 is performed by wrapping a band 45 around the pipe 100 and tightening it.

[0020] The main body-side pipe mounting portion 30 has two band openings 40 formed at each of both longitudinal end sides of the pipe 100, through which bands 45 are inserted in the circumferential direction of the pipe 100, and the bands 45 inserted into the two band openings 40 are tightened to fix the main body-side pipe mounting portion 30 and the outer pipe mounting portion 20 to the pipe 100. Since the two band openings 40 are formed at both longitudinal end sides, four band openings 40 are formed. The longitudinal end sides of the pipe 100 are regions in the longitudinal direction (±Y direction) where the device main body 10 is not mounted.

[0021] The band 45 is, for example, a screw-type hose band. The screw-type hose band is fixed by inserting the tip of the band through one of the band openings 40 from above, wrapping it around the outer pipe mounting portion 20 at the bottom of the pipe 100, and then unwinding it from the bottom of the other band opening 40. The tip of the band is inserted into the threaded portion, engaging with the thread while turning the screw to tighten. This installation work can be performed entirely from the device main body 10 side, making it easy to install the clamp-on ultrasonic flowmeter 1 even on pipes in a location with limited working space. The band 45 is not limited to a screw-type hose band, and any other band that can be inserted through the band opening 40 and tightened may be used, such as a chain-type free band. Such a band 45 is also easy to remove.

[0022] In this embodiment, a hybrid fixing mechanism is employed that can further fix the main body-side pipe mounting portion 30 and the outer pipe mounting portion 20 with screws 23. Mounting using the band 45 allows the main body-side pipe mounting portion 30 and the outer pipe mounting portion 20 to be positioned generally opposite each other, allowing the ultrasonic signals L1 and L2 to pass through the axis of the pipe 100. However, mounting using the screw 23 can reliably position the main body-side pipe mounting portion 30 and the outer pipe mounting portion 20 opposite each other if there is space for installation work on the outer pipe mounting portion 20 side for a screwdriver or the like. It is also possible to temporarily fix the main body-side pipe mounting portion 30 and the outer pipe mounting portion 20 by turning the threads of the screw 23, and then fix them with the band 45. Temporarily fixing using the screw 23 ensures that the main body-side pipe mounting portion 30 and the outer pipe mounting portion 20 are positioned opposite each other, even when the band 45 is used. In particular, the weight of the device main body 10 can prevent the main body side pipe mounting portion 30 from shifting or moving due to rotation in the circumferential direction of the pipe 100 during mounting.

[0023] 3 to 5, four screw holes 20a through which screws 23 are inserted are formed in the outer pipe mounting portion 20, and four screw holes 31a corresponding to the positions of the screw holes 20a are formed in the main body side pipe mounting portion 30. The screw holes 31a are formed in a flange 31 that is bent into a U-shape. The four screw holes 20a and four screw holes 31a function to determine the opposing positions of the main body side pipe mounting portion 30 and the outer pipe mounting portion 20.

[0024] An opening 36 is formed in the center of the main body-side pipe mounting portion 30, through which the ultrasonic transmitting and receiving surfaces of the ultrasonic transducers 5 and 6 protrude in the -Z direction. The ultrasonic transmitting and receiving surfaces of the opening 36 protrude in the -Z direction by the thickness of the opening 36. An acoustic coupler rubber 50 is attached to the main body-side pipe mounting portion 30 (see FIG. 5). The acoustic coupler rubber 50 covers the opening 36, and the acoustic coupler rubber 50 and the ultrasonic transmitting and receiving surfaces of the ultrasonic transducers 5 and 6 abut against each other. The acoustic coupler rubber 50 is tightly attached to the ultrasonic transmitting and receiving surfaces of the ultrasonic transducers 5 and 6 when clamped to the pipe 100.

[0025] Furthermore, four screw positioning holes 34 are formed in the main body side pipe mounting part 30 when the device main body 10 is fixed and positioned by engaging with protrusions on the device main body 10. In this positioned state, the main body side pipe mounting part 30 is fixed to the device main body 10 by screwing in the screw holes 34a. Furthermore, pipe positioning recesses 32 are formed at the ends of the main body side pipe mounting part 30 in the ±Y direction.

[0026] Here, if the pipe 100 is made of resin, the ultrasonic signal is also reflected by the outer pipe mounting part 20. Therefore, as shown in Fig. 7(a), an ultrasonic signal in which the ultrasonic signal L1 reflected by the pipe 100 and the ultrasonic signal L1' reflected by the outer pipe mounting part 20 are superimposed reaches the ultrasonic transducer 6. This reduces the accuracy of the flow velocity measurement.

[0027] In contrast, in this embodiment, an opening 22 is formed in the outer pipe mounting part 20 at a position where the ultrasonic signal is reflected (see FIG. 4). The opening 22 is U-shaped according to the shape of the pipe, and is provided in the pipe abutment part 21 that contacts and clamps the pipe 100. As a result, as shown in FIG. 7(b), the ultrasonic signal L1' reflected by the outer pipe mounting part 20 disappears, and only the ultrasonic signal L1 reflected by the pipe 100 is received by the ultrasonic transducer 6, thereby improving the accuracy of flow velocity measurement. The shape of the opening 22 is arbitrary, as long as it is open at the position where the ultrasonic signal is reflected.

[0028] Here, step portions 24 are formed at both circumferential ends of the pipe 100 on each of the outer pipe mounting portion 20 on both longitudinal ends of the pipe 100, and mounting protrusions 42 that exceed the width of the band 45 are formed from steps 24a of the step portions 24 toward both longitudinal ends. The band 45 then fixes the outer pipe mounting portion 20 to the pipe 100 via the mounting protrusions 42. In this case, the steps 24a are formed at opposing positions corresponding to the inner end faces 40a of the band openings 40, and serve to guide the band 45. Therefore, even without mounting using screws 23, the position of the outer pipe mounting portion 20 is restricted by the band 45, and the main body-side pipe mounting portion 30 and the outer pipe mounting portion 20 can be easily mounted in opposing positions.

[0029] In this embodiment, the outer pipe mounting portion 20 can be manufactured by sheet metal processing, which does not require welding or other processing, thereby reducing costs. The main body side pipe mounting portion 30 can also be manufactured by sheet metal processing including bending, thereby reducing costs.

[0030] In this embodiment, even when clamp-on ultrasonic flowmeter 1 is attached to a pipe in a location with limited working space, attachment can be performed from the device main body 10 side using band 45, making the attachment work easier. In attachment using band 45, attachment of band 45 is guided by two band openings 40 and steps 24a, making it easy to arrange the main body side pipe attachment part 30 and the outer pipe attachment part 20 facing each other. In addition, attachment using screws 23 is also possible, and temporary fixation using these screws 23 makes the attachment work even easier and ensures that the opposite arrangement is achieved.

[0031] It should be noted that the present invention is not limited to the above-described embodiment, and can be freely modified without departing from the spirit of the present invention. [Explanation of symbols]

[0032] 1. Clamp-on ultrasonic flow meter 2 Control section 3 Display section 4 Cable connection 5,6 Ultrasonic transducer 7 Temperature measurement section 10. Device body 20 External pipe attachment 20a, 31a, 34a screw holes 21 Piping abutment 22 Opening 23 screws 24 Step 24a Step 30 Main body side piping attachment part 31 flange 32 Piping positioning recess 34 Screw positioning hole 36 Aperture 40 Band opening 40a Inner end surface 42 Mounting protrusion 45 bands 50 Acoustic Coupler Rubber 51,61 Wedge 52,62 Piezoelectric element 100 Piping L1,L1´,L2 Ultrasonic signal

Claims

1. A clamp-on ultrasonic flowmeter that uses ultrasonic waves to measure the flow rate of a fluid flowing through a pipe, a main body side pipe mounting portion that mounts an apparatus main body, on which an ultrasonic transducer that transmits and receives ultrasonic waves to and from the pipe, to the pipe; an outer pipe mounting portion disposed opposite the main body side pipe mounting portion with a pipe interposed therebetween; Equipped with a clamp-on ultrasonic flowmeter characterized in that the main body side pipe mounting portion has two band openings formed at each of the longitudinal end sides of the pipe, through which bands are inserted in the circumferential direction of the pipe, and the main body side pipe mounting portion and the outer pipe mounting portion are fixed to the pipe by tightening the bands inserted into the two band openings.

2. a step is formed at each of both longitudinal end sides of the outer pipe mounting portion of the pipe at both circumferential ends of the pipe, and mounting protrusions exceeding the width of the band are formed from the step toward both longitudinal end sides, and the band fixes the outer pipe mounting portion to the pipe via the mounting protrusions; 2. The clamp-on ultrasonic flowmeter according to claim 1, wherein the step is formed at a position facing an inner end surface of the band opening to guide the band.

3. 2. The clamp-on ultrasonic flowmeter according to claim 1, wherein the body-side pipe mounting portion and the outer pipe mounting portion can be screwed together at positions where they face each other relative to the pipe.

4. 4. The clamp-on ultrasonic flowmeter according to claim 1, wherein the band is a screw-type hose band.

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