CN217304219U - Film pressure sensor - Google Patents

Abstract

The utility model discloses a film pressure sensor, which comprises a body, wherein the body is a metal block, a cylindrical metal block bulge is arranged at the center of the top of the body, a cylindrical first cavity is arranged at the center of the cylindrical metal block bulge, a cylindrical second cavity is arranged at the bottom of the body, and the second cavity is separated from the first space by a film; a pressing plate is arranged at the top of the first cavity; evenly distributed has resistance strain gauge on the anchor ring that the second cavity top surpassed first cavity, thereby this application arouses first cavity through the clamp plate to warp and makes the film warp, do not have other external force direct action on the film, resistance strain gauge measuring precision has been guaranteed, and with resistance strain gauge setting on the anchor ring that the second cavity top surpassed first cavity, can avoid the load to transship the destruction phenomenon of the whole shearing that leads to, the measuring reliability of integrated device under extreme operating mode has been improved.

Description

A thin film pressure sensor

technical field

The utility model relates to the field of pressure sensors, in particular to a thin film pressure sensor.

Background technique

At present, the on-board weighing sensor solutions are mainly divided into two types: weighing pressure sensors and deformation displacement sensors.

The existing weighing and pressure sensors mainly include cantilever beam weighing sensors, spoke-type pressure sensors, S-type tension and pressure sensors, tension sensors, micro sensors, bellows-type sensors, column sensors, hanging sensors, multi-dimensional force sensors, Static torque sensor, dynamic torque sensor, etc. The above sensors are used in engineering fields of various industries. The measured data and accuracy of various applications are different, and a certain product needs to be selected according to the requirements.

In the application field of on-board weighing system, due to factors such as small installation space, frequent vibration and shock, and large preload force, the conventional weighing and pressure sensor products listed above cannot be suitable for this specific engineering application. The large-scale pressure sensor is too large to be installed; the smaller-sized sensor has a too small measurement range, which cannot meet the bearing capacity requirements of on-board weighing applications.

The deformation displacement sensor detects the micro-deformation variable or displacement of the frame or axle and converts it into weight through an algorithm. Big error.

At the same time, in the existing vehicle load sensor solutions, there are problems in the performance of the vehicle load under extreme conditions, and the damage to the sensor itself caused by the overall shear force caused by the vehicle overload cannot be avoided, thus affecting the vehicle weighing Therefore, this application proposes a solution to these problems.

Utility model content

Purpose of the utility model: The purpose of the utility model is to provide a thin film pressure sensor, which can reduce the measurement accuracy error caused by the unbalanced force, and at the same time can avoid the damage of the overall shear caused by the load overload, improve the Reliability of measurement accuracy under extreme operating conditions.

Technical solution: A thin film pressure sensor according to the present utility model includes a body, the body is a metal block, the center of the top of the body is provided with a cylindrical metal block protrusion, and the center of the cylindrical metal block protrusion is provided There is a cylindrical first cavity, the bottom of the body is provided with a cylindrical second cavity, the second cavity, the first cavity and the cylindrical metal block are concentric; the second cavity and the first cavity are concentric. The cavities are spaced apart by thin films; the top of the first cavity is provided with a pressure plate; and resistance strain gauges are evenly distributed on the annular surface of the top of the second cavity beyond the first cavity.

Preferably, the diameter of the second cavity is larger than the diameter of the first cavity, and the diameter of the second cavity is smaller than the diameter of the protrusion of the cylindrical metal block.

The diameter of the second cavity is larger than that of the first cavity and smaller than that of the cylindrical metal block, which can ensure that the stress of the first cavity is smaller than that of the second cavity, so that the bending moment on the film is more obvious and further improves the The accuracy of resistance strain gauge detection is improved.

Preferably, the bottom of the pressing plate is provided with a cylindrical metal block with the same diameter as the first cavity, and the top of the pressing plate is an arc-shaped protrusion.

The cylindrical metal block can locate the position of the pressure plate, and the arc-shaped protrusion on the top of the pressure plate can ensure the center of the external force load and help the pressure distribution of the load transfer to be more uniform, and finally improve the measurement accuracy

Preferably, the protruding height of the cylindrical metal block does not exceed 2 mm, and is connected with the inner wall of the first cavity by interference.

The interference connection ensures that the pressure plate can be firmly positioned over the body to carry the load.

Preferably, the thickness of the film is between 0.2 and 1 mm.

The thickness of the film is 0.2 to 1 mm, which can directly ensure that the application can be applied to a large range of load ranges.

Preferably, a circuit board electrically connected to the resistance strain gauge is arranged in the second cavity, and the circuit board transmits signals to the outside through wires arranged in the through holes on the side of the body.

Beneficial effects:

(1) In the present application, the load acts on the pressure plate, causing the deformation of the first cavity to deform the film, and no other external force acts directly on the film, which ensures the measurement accuracy of the resistance strain gauge.

(2) In this application, the arc-shaped convex pressure plate ensures that when the position of the external force is offset, due to the symmetry of the circumference of the arc-shaped convex pressure plate, it is ensured that the load still generates an internal force bending moment in the middle, and will not Affects the accuracy of pressure measurement.

(3) In the present application, by arranging the resistance strain gauge on the annular surface of the top of the second cavity beyond the first cavity, the damage phenomenon of the overall shear caused by the overload of the load can be avoided, and the extreme working conditions of the overall device can be improved. reliability of the measurement.

Description of drawings

1 is a side cross-sectional view of a pressure plate in the present application;

Fig. 2 is the side sectional view of the body in the present application;

FIG. 3 is a plan view of the present application.

Detailed ways

The present application will be further described below with reference to specific embodiments.

As shown in Figures 1-3, which are schematic structural diagrams of the application, in this embodiment, the main body 1 is a metal block, the top center of the main body 1 is provided with a cylindrical metal block protrusion 2, and the center of the cylindrical metal block protrusion 2 is provided There is a cylindrical first cavity 3, and a cylindrical second cavity 4 is arranged at the bottom of the body 1. The first cavity 3, the second cavity 4 and the cylindrical metal block protrusion 2 are concentric. A thin film 5 with a thickness of 0.6 mm is arranged between the second cavity 4 and the second cavity 4 , and resistance strain gauges 7 are evenly distributed on the annular surface of the top of the second cavity 4 beyond the first cavity 3 .

In this embodiment, the diameter of the second cavity 4 is larger than the diameter of the first cavity 3 and smaller than the diameter of the cylindrical metal block protrusion 2 , and this arrangement can ensure that the stress of the first cavity 3 is smaller than that of the second cavity 3 The stress of the cavity 4 is reduced, so that the bending moment on the film 5 is more obvious, and the detection accuracy of the resistance strain gauge 7 is further improved.

In this embodiment, the top of the first cavity 3 is provided with a pressure plate 6, the top of the pressure plate 6 is an arc-shaped protrusion, and the bottom of the pressure plate 6 is provided with a cylindrical metal block 8 with the same diameter as the first cavity 3. The protruding height of the metal block 8 is 2mm, and it is connected with the inner wall of the first cavity 3 by interference. The pressure plate 6 is positioned above the body 1 through the cylindrical metal block 8 to carry the load. It can ensure that the external force load still generates the internal force bending moment in the middle, and the pressure distribution that helps the load transfer is more uniform, and finally the measurement accuracy is improved.

In this embodiment, a circuit board electrically connected to the resistance strain gauge 7 is provided in the second cavity 4 , and the circuit board transmits signals to the outside through the wires provided in the through holes 9 on the side of the body 1 .

When the present embodiment is installed on the vehicle, the second cavity 4 is positioned and installed with the positioning block on the vehicle, the vehicle load is connected to the arc-shaped protrusion on the top of the pressure plate 6, and the load exerts pressure on the pressure plate 6, because the arc of the pressure plate 6 The surrounding symmetry of the shaped bulge generates an internal force bending moment in the middle of the pressure plate 6, which causes the first cavity 3 to deform, thereby deforming the membrane 5, and the membrane 5 deforms to cause strain on the resistance strain gauge 7, thereby generating a pressure signal. .

In this application, only the deformation of the first cavity 3 leads to the deformation of the film 5, and no other external force directly acts on the film 5, which ensures the measurement accuracy of the resistance strain gauge 7, and the arc-shaped convex pressure plate 6 ensures the position of the external force. When there is an offset, the accuracy of the pressure measurement will not be affected, and the resistance strain gauge 7 is arranged on the annular surface of the top of the second cavity 4 beyond the first cavity 3, which can avoid the damage of the overall shear caused by the overload of the load. , which improves the reliability of the overall device measurement under extreme conditions.

Claims (6)

1. A film pressure sensor, including body (1), its characterized in that: the metal block type heat exchanger comprises a body (1), a cylindrical metal block protrusion (2) is arranged in the center of the top of the body (1), a cylindrical first cavity (3) is arranged in the center of the cylindrical metal block protrusion (2), a cylindrical second cavity (4) is arranged at the bottom of the body (1), and the second cavity (4), the first cavity (3) and the cylindrical metal block protrusion (2) are concentric; the second cavity (4) is separated from the first cavity (3) through a thin film (5); a pressing plate (6) is arranged at the top of the first cavity (3); and resistance strain gauges (7) are uniformly distributed on the circular ring surface of the top of the second cavity (4) exceeding the first cavity (3).

2. The membrane pressure sensor of claim 1, wherein: the diameter of the second cavity (4) is larger than that of the first cavity (3), and the diameter of the second cavity (4) is smaller than that of the cylindrical metal block bulge (2).

3. The membrane pressure sensor of claim 1, wherein: the bottom of the pressing plate (6) is provided with a cylindrical metal block (8) with the same diameter as the first cavity (3), and the top of the pressing plate (6) is a circular arc-shaped bulge.

4. A membrane pressure sensor according to claim 3, wherein: the protruding height of the cylindrical metal block (8) is not more than 2mm, and the cylindrical metal block is in interference connection with the inner wall of the first cavity (3).

5. The membrane pressure sensor of claim 1, wherein: the thickness of the film (5) is between 0.2 and 1 mm.

6. The membrane pressure sensor of claim 1, wherein: and a circuit board electrically connected with the resistance strain gauge (7) is arranged in the second cavity (4), and the circuit board transmits signals outwards through wires arranged in the through holes (9) on the side surface of the body (1).

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