JPH05502297A - Ultrasonic Transducer Sonic Insulated Holding Device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Sonically insulated holding device for an ultrasonic transducer The present invention is a device for applying ultrasonic radiation to a gaseous medium. Holding device for an ultrasound transducer for transmitting or receiving ultrasound radiation therefrom Regarding.

Ultrasonic radiation from the vibrating solid surface of the transducer to the gaseous medium The result is a very large difference, on the order of 10 to the 4th power, in the acoustic impedance of the materials of , leading to a negligible power transfer ratio from solid to gaseous medium and vice versa. .

Ultrasonic transducers are used specifically for flowing media, e.g. to determine the volume of gas flowing through a tube. Used in ultrasonic measurement equipment. One application of such devices is gas meters, In particular, it is applied as a household gas meter.

In such devices, the ultrasonic transducer that determines the measuring section in the tube is oriented with respect to the tube axis. Arranged at relatively small intervals of, for example, 240mm! has been done. Generally these changes The converter is inserted into the pipe wall and directs ultrasonic waves at an angle to the pipe axis to direct the flowing gaseous medium. radiate to pass through. One converter is then a transmitting converter and the other converter is a transmitting converter. The transducer is a receiving transducer. In general, measurements are taken alternately upstream and downstream, and the resulting This is done by forming a difference between the numbers. This type of ultrasonic flowmeter is patented in Germany @ No. P39 No. 41546.5, No. P3941545.7 and No. P3941544.9 and the present invention is an advantageous development of one of them.

With small transducer spacings as shown, the resultant flow noise is significant. However, it is difficult to evaluate the received signal, for example, when the sound is relatively far away. decisively adversely influenced by the sound wave intensity originating from the source and transmitted through the tube wall. . In order to minimize this solid-state sound transmission, the transducers used, i.e. The transducer is installed in the device or in the pipe wall, where the transducer block and the pipe wall are involved in sound wave transmission. shall be installed in such a way that they are substantially insulated from each other. another call by using at least in part a material with acoustic damping properties in the transducer. can be achieved.

The problem of the present invention is to solve the problem of sonic insulation, which is especially suitable for mass production of solid-state transducers of ultrasonic flowmeters. It is an object of the present invention to provide a holding device with a high quality.

This problem is solved by the features of the claims.

Figure 1 shows the principle circle of a tube-shaped ultrasonic flowmeter, which guides the flowing medium. Two ultrasonic transducers 3 are attached to the tube. As is clear from the drawing, These ultrasonic transducers 3 are positioned in support IOs inserted into the tube wall and oriented obliquely. 1. Measuring equipment used to measure gases that must not particularly leak outside. ! Now, get dressed! but the analogy has to be opened for insertion or replacement of transducer 3. Appropriate sealing must be provided where there is no seal.

FIG. 2 shows such a side pipe connecting support 51 shown in FIG. 1 in detail in a sectional view. shown in detail. This support 1 is the actual support for the transducer 11. diagonal The cut tubular support 51 has steps 52 . The outer tube end of the support 51 is connected to the cover 5 The sealing ring 57 is installed in the groove 56 when the sealing ring 57 is closed. It is being The cover 58 is tightened using the ring 55 as an attached part as shown in the drawing. and have it. For this tightening, the ring 55 has dimensions that match the diameter of the step 52 of the support 51. has been done. As is clear from Figure 2, it is arranged! rubber or comparable An O-ring 54 is provided which is made of a permanently elastic material that can be used. 200 ring 54 In addition to serving as an additional seal, it also holds the transducer 53 within the support 51. The 0 stage 2 is tightened by the precision of the 0 ring 54 in the support 51 in cooperation with the ring 55. The ring groove 59 inside the transducer 11 is and its precise positioning.

In order to make the drawing easier to read, illustration of the electrical connections of the converter 11 is omitted. that are provided on the wall of the support 51 with a conductive wire led through the cover 58 or supported on the side. These terminals may be feed-through terminals that have significant solid-state sound transmission. This means that, for example, the connection Guaranteed by the use of stranded wire.

The holding device for the transducer 11 according to the invention has been described in the previous patent application no. P3832947 ( = GR88P1653). Main departure According to Ming, sound waves l! Optimization of the edge retaining device compresses the ○su/g 54 into a straight line. Compression is achieved by means of a nolinder-shaped tightening mechanism. is caused by the ring 55. In the present invention, only minimal surface contact is applied to the parasitic sound wave path. There is one (dual) edgest knob with. Insert the cover 58 into the groove 57. Additional tooling that compresses when screwed in and provides a permanent, secure seal. The sealing ring 57 forms an essentially gas-tight seal.

According to measure 1 according to the present invention, 140 dB or more is buried in the noise of the received signal. Even smaller solid-state sound levels are achieved. According to the invention, it is airtight and However, it has high acoustic decoupling and precisely defined transducer positioning. A configuration is achieved.

Assignment of steps 52 and rings 55 to supports and converter profile according to claims , the correspondence of the groove 56 to the evening may be reversed, but the former arrangement is preferable. stomach.

In one embodiment of the invention, a permanently elastic material is provided in an area close to the acoustic wave emitting front of the transducer 3. A second O-ring 154 made of metal is also provided. This ring 154 is advantageously , the gap 1 necessarily existing between the outer wall of the transducer 11 and the ring-shaped inner surface of the tube support 51 It plays the role of closing 1:60. That is, the flow through the measuring tube 2 is advantageously placed in this gap. It has been found that dust, small particles, etc. that are entrained in the gases that are released are deposited. this child is inserted into the groove 156 of the transducer 11 and the groove 155 on the inner surface of the support 51. This is avoided by the ring 154 that is present.

FIG 2 abstract between linear contacts (2, 5, 6) distributed in accordance with the principle of retention; one of them (groove 6) holds the transducer (3).

international search report S^　43445

Claims (7)

[Claims] 1. Place the ultrasonic transducer (11) into the support (51) of the ultrasonic flowmeter (Fig. 1). In an acoustically insulated holding device for precise positioning - in the support (51) An O-ring made of a permanently elastic material is provided at the location of the holder of the acoustic transducer (11). The O-ring (54) is connected to the inner step (54) of the support (51). 2), - a ring (located inside the support (51) on the opposite side of the step (52) in the axial direction; 55) edge and - positioned between - a groove (56) located in the outer wall of the transducer (53); - the edges of the step (52) and the ring (55) run annularly around the periphery and press It has a merely linear contact under compression with the O-ring (54), and the -groove (57) forming a third annular stop for a third O-ring (54); - linear contact and this stop is mutually connected in the groove (57) on the principle of three-point retention; distributed in A holding device for an ultrasonic transducer characterized by: 2. Claims characterized in that an O-ring (54) made of rubber is provided. The holding device according to box 1. 3. characterized in that one ring is provided which is a tightening ring (55) 3. The holding device according to claim 1 or 2. 4. One ring (55) as part of the cover (58) of the support (51) is stepped. Holding device according to one of claims 1 to 3, characterized in that: 5. Claim characterized in that the support (51) is closed by a cover (58) A holding device according to one of ranges 1 to 4. 6. Sealing ring (57) to cover support (51) and cover (58) The holding according to claim 5, characterized in that the holding device is provided with:. 7. Permanent grooves (156, 155) of transducer (11) and inner surface of tube support (51) Claim characterized in that a further ring (154) of elastic material is located. A holding device according to one of ranges 1 to 6.