High-temperature-resistant combined externally-pasted ultrasonic flow sensor

Abstract

The utility model relates to a combined type externally-pasted ultrasonic flow sensor capable of resisting high temperature, and belongs to the technical field of flow sensors. According to the technical scheme, an insulating spacer (3) is arranged on a piezoelectric ceramic piece (4), a fastening screw (6) is arranged on the insulating spacer (3), and the fastening screw (6) presses and fixes the piezoelectric ceramic piece (4) on a joint face (13) in a sensor shell (1) through the insulating spacer (3); a middle gasket (2) is arranged between the insulating gasket (3) and the fastening screw (6), and the fastening screw (6) compresses the insulating gasket (3) through the middle gasket (2). The beneficial effects of the utility model are that the piezoelectric ceramic piece is fastened in the sensor housing through the elastic pressing piece, so that separation at high temperature can be avoided, and the temperature of a medium conveyed by a pipeline on site is gt; and the paint can be normally used at 80 DEG C.

Description

Technical Field

[0001] The utility model relates to a high-temperature resistant combined external ultrasonic flow sensor, belonging to the technical field of flow sensors. Background Art

[0002] The ultrasonic flow sensor is the core component of the current general ultrasonic flowmeter, and generally has two installation forms: external attachment type and contact type. The external attachment type ultrasonic sensor can be installed without stopping the production of the on-site pipeline. The installation is simple and convenient, and it can be widely used in fields such as petroleum, chemical industry, metallurgy, electric power, water supply and drainage, etc. The piezoelectric ceramic sheet of the external attachment type ultrasonic flow sensor is fixed to the sensor housing by bonding. For example, in Chinese Patent CN201320143084.5 titled "An Open Ultrasonic Sensor", etc. The problems existing in the above-mentioned prior art are: This way of fixing the piezoelectric ceramic sheet to the sensor housing by bonding is only applicable to places where the temperature of the medium transported by the on-site pipeline ≤ 80°C. When the temperature of the medium transported by the on-site pipeline > 80°C, the adhesive between the piezoelectric ceramic sheet and the housing of the ultrasonic flow sensor may fail due to high temperature, resulting in the separation of the two and the damage of the flow sensor. Content of the Utility Model

[0003] The purpose of the utility model is to provide a high-temperature resistant combined external ultrasonic flow sensor. The piezoelectric ceramic sheet is fastened in the sensor housing by an elastic pressing sheet, which can avoid separation at high temperature and can be normally used in places where the temperature of the medium transported by the on-site pipeline > 80°C, and solve the above-mentioned technical problems existing in the prior art.

[0004] The technical solution of the utility model is as follows:

[0005] A high-temperature resistant combined external ultrasonic flow sensor, a piezoelectric ceramic sheet is arranged on the joint surface inside the sensor housing, and the lead of the piezoelectric ceramic sheet is connected to the cable and locked by a wire locking nozzle; an insulating gasket is arranged on the piezoelectric ceramic sheet, and a fastening screw is arranged on the insulating gasket. The fastening screw presses and fixes the piezoelectric ceramic sheet on the joint surface inside the sensor housing through the insulating gasket.

[0006] Further, an intermediate gasket is arranged between the insulating gasket and the fastening screw, and the fastening screw presses the insulating gasket through the intermediate gasket.

[0007] Further, the joint surface inside the sensor housing is arranged obliquely, and inclined grooves are arranged on the inner wall of the sensor housing. An elastic pressing sheet is arranged in the inclined grooves. The side surface of the elastic pressing sheet is flush. The flush side of the elastic pressing sheet slides into the inclined grooves and is stuck in the inclined grooves. The elastic pressing sheet extends above the piezoelectric ceramic sheet; a threaded hole is arranged on the elastic pressing sheet, and the upper end of the fastening screw is matched in the threaded hole, and the lower end of the fastening screw abuts against the intermediate gasket.

[0008] Furthermore, the upper part of the sensor housing is open and is fastened to the stainless-steel housing by countersunk screws. There is a glue injection hole on the stainless-steel housing that seals the sensor housing. Dazexi thermally conductive insulating sealant is filled into the internal space of the sensor housing through the glue injection hole, and the glue injection hole is sealed with a plug board.

[0009] Furthermore, the sensor housing is provided with screw holes that match the countersunk screws.

[0010] Furthermore, the sensor housing is a high-temperature resistant non-metallic housing.

[0011] The beneficial effects of the present utility model: The piezoelectric ceramic sheet is fastened in the sensor housing by an elastic pressing sheet, which can avoid bone detachment at high temperatures and can be used normally in places where the temperature of the pipeline conveying medium on-site > 80°C. Description of the Drawings

[0012] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0013] Figure 2 is a schematic structural diagram of the sensor housing of an embodiment of the present utility model;

[0014] Figure 3 is a schematic structural diagram of the elastic pressing sheet of an embodiment of the present utility model;

[0015] In the figure: sensor housing 1, intermediate gasket 2, insulating gasket 3, piezoelectric ceramic sheet 4, elastic pressing sheet 5, fastening screw 6, stainless-steel housing 7, plug board 8, cable gland 9, cable 10, countersunk screw 11, inclined groove 12, joint surface 13, screw hole 14, threaded hole 15, lead wire 16. Detailed Embodiment

[0016] The present utility model is further elaborated in detail through the following embodiments.

[0017] Referring to the attached Figure 1 , this embodiment provides a combined externally attached ultrasonic flow sensor that can withstand high temperatures. A piezoelectric ceramic sheet 4 is arranged on the joint surface 13 inside the sensor housing 1. The lead wire 16 of the piezoelectric ceramic sheet 4 is connected to the cable 10 and locked through the cable gland 9; its characteristics are: an insulating gasket 3 is arranged on the piezoelectric ceramic sheet 4, a fastening screw 6 is arranged on the insulating gasket 3, and the fastening screw 6 presses and fixes the piezoelectric ceramic sheet 4 on the joint surface 13 inside the sensor housing 1 through the insulating gasket 3.

[0018] Referring to the attached Figure 1 , an intermediate gasket 2 is arranged between the insulating gasket 3 and the fastening screw 6, and the fastening screw 6 presses the insulating gasket 3 through the intermediate gasket 2.

[0019] Referring to the attached Figure 1and 2 The joint surface 13 inside the sensor housing 1 is arranged obliquely. An inclined groove 12 is provided on the inner wall of the sensor housing 1. An elastic pressing piece 5 is arranged in the inclined groove 12. The side surface of the elastic pressing piece 5 is flush. The flush side of the elastic pressing piece 5 slides into the inclined groove 12 and is stuck in the inclined groove 12. The elastic pressing piece 5 extends above the piezoelectric ceramic sheet 4. A threaded hole 15 is provided on the elastic pressing piece 5. The upper end of the fastening screw 6 is fitted in the threaded hole 15, and the lower end of the fastening screw 6 abuts against the intermediate gasket 2.

[0020] Refer to the attached Figure 1 The upper part of the sensor housing 1 is open and is fastened to the stainless steel housing 7 by countersunk head screws 11. A glue injection hole is provided on the stainless steel housing 7 that closes the sensor housing 1. The internal space of the sensor housing 1 is filled with Dazexi thermally conductive insulating sealant through the glue injection hole, and the glue injection hole is sealed with a plug plate 8.

[0021] Refer to the attached Figure 2 The sensor housing 1 is provided with four screw holes 14, which are respectively matched with the four countersunk head screws 11.

[0022] Preferably, the sensor housing 1 is a high-temperature resistant non-metallic housing.

[0023] In this embodiment, the material of the sensor housing 1 is selected as a non-metallic material - polyarylsulfone that is high-temperature resistant and easy to process. The shape is a cuboid, and the upper part is open. The joint surface 13 inside the sensor housing 1 is arranged obliquely, and the surface finish of the joint surface 13 is not greater than 3.2 um The piezoelectric ceramic sheet 4 is placed on the joint surface 13. An inclined groove 12 is provided on the inner wall of the sensor housing 1. The side surface of the elastic pressing piece 5 is flush. The flush side of the elastic pressing piece 5 slides into the inclined groove 12 to a predetermined position, and the elastic pressing piece 5 is clamped and fixed in the inclined groove 12. The elastic pressing piece 5 is located above the piezoelectric ceramic sheet 4. The material of the elastic pressing piece 5 is selected as 65Mn spring steel, and a threaded hole 15 is provided at the middle position for screwing in the fastening screw 6. By screwing the fastening screw 6 tightly, the intermediate gasket 2, the insulating gasket 3 and the piezoelectric ceramic sheet 4 are pressed together on the joint surface 13 inside the sensor housing 1.

[0024] Sensor assembly steps of this embodiment: ① Evenly apply a coupling agent on the joint surface 13 inside the sensor housing 1; ② Place the piezoelectric ceramic sheet 4 flat on the joint surface 13, and then stack the insulating gasket 3 and the intermediate gasket 2 on the piezoelectric ceramic sheet 4 in sequence; ③ Slide the elastic pressing piece 5 along the inclined groove 12 on the inner wall of the sensor housing, screw the fastening screw 6 into the threaded hole 15 on the elastic pressing piece 5 and tighten it until the piezoelectric ceramic sheet 4, the insulating gasket 3 and the intermediate gasket 2 are positioned on the joint surface 13 of the sensor housing 1; ④ Fasten the stainless steel outer shell 7 to the sensor housing 1 with four countersunk head screws 11; ⑤ Connect the lead 16 of the piezoelectric ceramic sheet 4 to the cable 10, and then pass the cable 10 through the wire locking nozzle 9 and tighten it; ⑥ Pour the thermally conductive insulating sealant into the sensor housing 1 through the glue injection hole on the stainless steel outer shell 7 until it is full; ⑦ Plug the glue injection hole on the stainless steel outer shell 7 with the plug plate 8.

Claims

1. A high-temperature-resistant combined external ultrasonic flow sensor, on the joint surface (13) inside the sensor housing (1), a piezoelectric ceramic sheet (4) is provided, and the lead wire (16) of the piezoelectric ceramic sheet (4) is connected to the cable (10) and locked through the wire locking nozzle (9); characterized in that: An insulating gasket (3) is provided on the piezoelectric ceramic sheet (4), and a fastening screw (6) is provided on the insulating gasket (3). The fastening screw (6) presses and fixes the piezoelectric ceramic sheet (4) on the joint surface (13) inside the sensor housing (1) through the insulating gasket (3).

2. The combined external ultrasonic flow sensor capable of withstanding high temperatures according to claim 1, characterized in that: An intermediate gasket (2) is provided between the insulating gasket (3) and the fastening screw (6), and the fastening screw (6) presses the insulating gasket (3) through the intermediate gasket (2).

3. The combined external ultrasonic flow sensor capable of withstanding high temperatures according to claim 2, wherein: The joint surface (13) inside the sensor housing (1) is arranged obliquely. An inclined groove (12) is provided on the inner wall of the sensor housing (1). An elastic pressing piece (5) is arranged in the inclined groove (12). The side surface of the elastic pressing piece (5) is flush. The flush side of the elastic pressing piece (5) slides into the inclined groove (12) and is stuck in the inclined groove (12). The elastic pressing piece (5) extends above the piezoelectric ceramic sheet (4). A threaded hole (15) is provided on the elastic pressing piece (5). The upper end of the fastening screw (6) is matched in the threaded hole (15), and the lower end of the fastening screw (6) abuts against the intermediate gasket (2).

4. The combined external ultrasonic flow sensor capable of withstanding high temperatures according to claim 1, characterized in that: The upper part of the sensor housing (1) is open and is fastened together with a stainless steel outer shell (7) by a countersunk head screw (11). A glue injection hole is provided on the stainless steel outer shell (7) that closes the sensor housing (1). The inner space of the sensor housing (1) is filled with Dazexi thermally conductive insulating sealant through the glue injection hole, and the glue injection hole is sealed with a plug plate (8).

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