Internally-attached sensing device for flow meter

Abstract

The utility model belongs to the technical field of sensors, and particularly relates to an internally-attached sensing device for a flow meter, which comprises a connecting seat, a sensor and a target rod which are sequentially connected, and a target sheet is arranged at the bottom of the target rod; the sensor comprises a thin-wall shell, joints are arranged at the two ends of the thin-wall shell, and a connecting seat and a target rod are connected with the two joints respectively; the thin-wall shell comprises a first groove-shaped plate and a second groove-shaped plate which are symmetrically arranged, the section of the first groove-shaped plate and the section of the second groove-shaped plate are in a concave shape, strain gauges are arranged on the lower concave faces of the first groove-shaped plate and the second groove-shaped plate, and the planes where the two strain gauges are located are parallel to the plane where the target piece is located. The problems that the metering effect of a flowmeter is affected due to the fact that the interior of an externally-attached sensor is prone to blockage, and an internally-attached sensor is complex in structure and high in manufacturing cost are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of sensors, and particularly relates to an inner-mounted sensing device for a flowmeter. Background Art

[0002] A target flowmeter generally includes a measuring tube, a force-bearing element disposed in the measuring tube, a sensor fixedly disposed on the measuring tube, a force-transmitting rod connected between the sensor and the force-bearing element, and a data processing device connected to the sensor. Its working principle is as follows: The fluid generates momentum during movement in the measuring tube, and a pressure difference is generated between the upstream side and the downstream side of the force-bearing element. The fluid momentum and pressure difference generate corresponding acting forces on the force-bearing element. The acting force is transmitted to the sensor through the force-transmitting rod. The sensor converts the acting force into a corresponding electrical signal and transmits it to the data processing device, and the data processing device calculates the corresponding flow value.

[0003] Existing target flowmeters usually adopt externally-mounted sensors. The externally-mounted sensor includes a metal elastic cylinder and strain gauges disposed on the outer wall of the metal elastic cylinder. When the target flowmeter is used to measure media such as dirty, sticky, and easy-to-crystallize media, with the accumulation of the usage time, the inside of the sensor is prone to blockage, affecting the sensing effect of the sensor, and further causing the flowmeter to measure incorrectly or the measurement to fail.

[0004] The utility model patent with the publication number of CN 201653457 U discloses a sensing device for a flowmeter, which adopts an internal strain gauge structure. A thin-walled metal elastic bellows is used to seal the strain body to ensure that the strain gauges are completely isolated from the measured medium, avoiding blockage inside the sensing device. However, the overall structure is relatively bulky. To meet its installation requirements, the sizes of other components such as the measuring tube of the flowmeter need to be enlarged, increasing the manufacturing cost. Summary of the Utility Model

[0005] The purpose of the utility model is to provide an inner-mounted sensing device for a flowmeter to solve the problems that the inside of the externally-mounted sensor is prone to blockage, affecting the measurement effect of the flowmeter, and the inner-mounted sensor has a complex structure and a high manufacturing cost.

[0006] To solve the above technical problems, the utility model provides the following technical solutions:

[0007] An inner-mounted sensing device for a flowmeter includes a connecting seat, a sensor, and a target rod connected in sequence. A target piece is provided at the bottom of the target rod; the sensor includes a thin-walled housing, and joints are provided at both ends of the thin-walled housing. The connecting seat and the target rod are respectively connected to the two joints; the thin-walled housing includes a first channel-shaped plate and a second channel-shaped plate symmetrically arranged. The cross-sections of the first channel-shaped plate and the second channel-shaped plate are in a "concave" shape, and strain gauges are provided on the concave surfaces of the first channel-shaped plate and the second channel-shaped plate. The planes where the two strain gauges and the target piece are located are parallel to each other.

[0008] Furthermore, first reinforcing plates are provided on both sides of the first channel-shaped plate, and second reinforcing plates are provided on both sides of the second channel-shaped plate. The first reinforcing plates and the second reinforcing plates at corresponding positions overlap each other, and both ends of the first reinforcing plates and the second reinforcing plates are respectively connected to the two connectors.

[0009] Furthermore, the connector is in the shape of a cylindrical boss. The connector includes a first connector and a second connector which are symmetrically arranged, and the first connector and the second connector are respectively arranged at the ends of the first channel-shaped plate and the second channel-shaped plate.

[0010] Furthermore, the concave surfaces of the first channel-shaped plate and the second channel-shaped plate are polished with sandpaper to form rough surfaces.

[0011] Furthermore, the first channel-shaped plate, the first reinforcing plate and the first connector, and the second channel-shaped plate, the second reinforcing plate and the second connector are all of an integral structure.

[0012] The working principle of the present utility model is as follows:

[0013] When the measured medium flows, it impacts the target plate installed at the bottom of the target rod. The target rod generates displacement under the force. Since the position where the strain gauge is located is the thinnest part of the sensor, relatively large stress and strain are generated at this place. The deformation of the strain gauge causes the Wheatstone bridge to generate an electrical signal, and this signal is converted by the instrument transmitter to complete the metering action.

[0014] Compared with the prior art, the present utility model has the following beneficial technical effects:

[0015] 1. In this application, the strain gauge is arranged inside the thin-walled shell, which can effectively isolate the contact between the medium and the strain gauge. Compared with the structure of the traditional external-mounted sensor, there is no inner cavity and narrow gap for the medium to pass through in the structure of this application, which can effectively solve the problem of the movement jamming of the sensing device caused by the adhesion and crystallization of the medium during long-term use; compared with the structure of the existing external-mounted sensing device, the structure of this application is compact and small in size, will not affect the component design size of the flowmeter, and saves manufacturing costs.

[0016] 2. Existing sensors usually attach the strain gauge to a curved surface structure to improve the sensing accuracy. However, limited by the acceptable curvature of the strain gauge, the radius of the installation surface of the strain gauge needs to be increased, resulting in a relatively large overall structure of the sensor and unable to be miniaturized; the installation surface of the strain gauge in this application is a plane, which is not limited by the external dimension of the thin-walled shell, and can be miniaturized to different degrees according to actual needs; moreover, the strain gauge attached to the plane can achieve high-precision flow metering. By grinding the installation surface, the adhesion effect between the strain gauge and the installation surface can be better, the strain sensitivity can be improved, and the detection sensitivity can be effectively enhanced on the basis of broadening the medium applicability. Description of the Drawings

[0017] Figure 1 is the front view of the present utility model;

[0018] Figure 2 is the side view of the present utility model;

[0019] Figure 3 is the structural schematic diagram of the sensor of the present utility model;

[0020] Figure 4 is Figure 2 the sectional view in the A-A direction of

[0021] The reference numerals in the accompanying drawings of the specification include: connecting seat 1, sensor 2, first channel-shaped plate 21, second channel-shaped plate 22, strain gauge 23, first reinforcing plate 24, second reinforcing plate 25, first joint 26, second joint 27, target rod 3, and target piece 4. Specific embodiments

[0022] The following is a further detailed description through specific embodiments:

[0023] Embodiment

[0024] As Figures 1-4 shown, an in-line sensing device for a flow meter includes a connecting seat 1, a sensor 2, and a target rod 3 that are connected in sequence. A target piece 4 is provided at the bottom of the target rod 3; the sensor 2 includes a thin-walled housing. Both ends of the thin-walled housing are provided with joints, and the connecting seat 1 and the target rod 3 are respectively connected to the two joints; the thin-walled housing includes symmetrically arranged first channel-shaped plate 21 and second channel-shaped plate 22. The cross-sections of the first channel-shaped plate 21 and the second channel-shaped plate 22 are in a "concave" shape. The concave surfaces of the first channel-shaped plate 21 and the second channel-shaped plate 22 are polished with sandpaper into rough surfaces. Strain gauges 23 are pasted on the concave surfaces of the first channel-shaped plate 21 and the second channel-shaped plate 22. The planes where the two strain gauges 23 and the target piece 4 are located are parallel to each other.

[0025] In this application, the strain gauge 23 is arranged inside the thin-walled housing, which can effectively isolate the contact between the medium and the strain gauge 23. The structure of the sensor 2 has no internal cavity and narrow gaps for the medium to pass through, which can effectively solve the problem of the movement jamming of the sensing device caused by the adhesion and crystallization of the medium during long-term use; the installation surface of the strain gauge 23 is a plane, which is not limited by the external dimensions of the thin-walled housing, and the size reduction can be achieved to different degrees according to actual needs; moreover, the strain gauge 23 pasted on the plane can achieve high-precision flow measurement. By sandblasting the installation surface, the adhesion effect between the strain gauge 23 and the installation surface can be better, improving the strain sensitivity. On the basis of broadening the medium applicability, the detection sensitivity is effectively improved.

[0026] As Figures 3-4As shown, first reinforcing plates 24 are formed on both sides of the first channel-shaped plate 21, and second reinforcing plates 25 are formed on both sides of the second channel-shaped plate 22. The first reinforcing plates 24 and the second reinforcing plates 25 at corresponding positions overlap each other, and both ends of the first reinforcing plates 24 and the second reinforcing plates 25 are respectively connected to two connectors; by providing the first reinforcing plates 24 and the second reinforcing plates 25, the sensor 2 can have a certain impact resistance, and on the premise of ensuring the sensitivity of the strain gauges 23, the service life of the sensing device can be extended.

[0027] As Figures 3-4 shown, both connectors include a first connector 26 and a second connector 27 which are symmetrically arranged. The first connector 26 and the second connector 27 are respectively arranged at the ends of the first channel-shaped plate 21 and the second channel-shaped plate 22. Grooves are formed on the first connector 26 and the second connector 27, and the first connector 26 and the second connector 27 at corresponding positions are buckled to form a connector in the shape of a cylindrical boss.

[0028] The first channel-shaped plate 21, the first reinforcing plates 24 and the first connector 26, as well as the second channel-shaped plate 22, the second reinforcing plates 25 and the second connector 27 are all of an integral structure. After the strain gauges 23 are installed on the concave surfaces of the first channel-shaped plate 21 and the second channel-shaped plate 22, the first channel-shaped plate 21, the first reinforcing plates 24 and the first connector 26 are respectively buckled together with the second channel-shaped plate 22, the second reinforcing plates 25 and the second connector 27, and the edges are sealed by laser welding. Then, the connecting seat 1 and the target rod 3 are also installed on the cylindrical boss connectors at both ends of the thin-walled housing by laser welding; the structure of the sensing device is simple, easy to manufacture and assemble, and the overall structure is compact with small size, which will not affect the design dimensions of the other components of the flowmeter and saves manufacturing costs.

[0029] The above are only embodiments of the present invention, and specific technical solutions and / or common knowledge such as characteristics well known in the art are not described in detail herein. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several deformations and improvements can be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application should be subject to the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. An in-line sensing device for a flowmeter, comprising a connecting seat (1), a sensor (2) and a target rod (3) connected in sequence, and a target piece (4) is provided at the bottom of the target rod (3), characterized in that: The sensor (2) includes a thin-walled housing. Connectors are provided at both ends of the thin-walled housing. The connecting seat (1) and the target rod (3) are respectively connected to the two connectors. The thin-walled housing includes a first channel-shaped plate (21) and a second channel-shaped plate (22) which are symmetrically arranged. The cross-sections of the first channel-shaped plate (21) and the second channel-shaped plate (22) are in a "concave" shape. Strain gauges (23) are provided on the concave surfaces of the first channel-shaped plate (21) and the second channel-shaped plate (22). The planes where the two strain gauges (23) and the target piece (4) are located are parallel to each other.

2. The in-pipe sticking type sensing device for a flowmeter according to claim 1, wherein: First reinforcing plates (24) are provided on both sides of the first channel-shaped plate (21), and second reinforcing plates (25) are provided on both sides of the second channel-shaped plate (22). The first reinforcing plates (24) and the second reinforcing plates (25) corresponding in position overlap each other, and the two ends of the first reinforcing plates (24) and the second reinforcing plates (25) are respectively connected to the two connectors.

3. The in-pipe sticking type sensing device for a flowmeter according to claim 2, characterized in that: The connector is in the shape of a cylindrical boss and includes a first connector (26) and a second connector (27) which are symmetrically arranged. The first connector (26) and the second connector (27) are respectively arranged at the ends of the first channel-shaped plate (21) and the second channel-shaped plate (22).

4. The in-pasted type sensing device for a flowmeter according to claim 1, wherein: The concave surfaces of the first channel-shaped plate (21) and the second channel-shaped plate (22) are polished with sandpaper to form rough surfaces.

5. The in-pipe sticking type sensing device for a flowmeter according to claim 3, characterized in that: The first channel-shaped plate (21), the first reinforcing plate (24) and the first connector (26), and the second channel-shaped plate (22), the second reinforcing plate (25) and the second connector (27) are all of an integral structure.

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