CN220153775U

CN220153775U - Film differential type wide-range pressure sensor

Info

Publication number: CN220153775U
Application number: CN202321299288.8U
Authority: CN
Inventors: 单臻; 孙健; 刘奥吉
Original assignee: Wuxi Shangheda Intelligent Technology Co ltd
Current assignee: Wuxi Shangheda Intelligent Technology Co ltd
Priority date: 2023-05-26
Filing date: 2023-05-26
Publication date: 2023-12-08
Anticipated expiration: 2033-05-26

Abstract

The utility model discloses a film differential type wide-range pressure sensor, which comprises a body, wherein the body is a metal block, a first cavity and a second cavity are respectively arranged in the body, a film is arranged between the first cavity and the second cavity, a first lug is arranged on the end surface of the film facing the first cavity, a plurality of uniformly distributed silicon strain gages are arranged at the junction of the first lug and the film, and meanwhile, the body is arranged on bearing columns at two sides of a vehicle through an external shell.

Description

Film differential type wide-range pressure sensor

Technical Field

The utility model relates to the field of pressure sensors, in particular to a film differential type wide-range pressure sensor.

Background

At present, the scheme of the vehicle-mounted weighing sensor is mainly divided into a weighing pressure sensor and a deformation displacement sensor.

The existing weighing pressure sensor mainly comprises a cantilever weighing sensor, a spoke type pressure sensor, an S-shaped tension pressure sensor, a tension sensor, a miniature sensor, a bellows type sensor, a column type sensor, a hanging type sensor, a multidimensional force sensor, a static torque sensor, a dynamic torque sensor and the like, wherein the sensors are used in various industrial engineering fields, the measured data and the measured precision of various applications are different, and certain products are required to be selected according to requirements.

In the application field of a vehicle-mounted weighing system, the conventional weighing pressure sensor product listed above cannot be suitable for the specific engineering application due to the factors of small installation space, frequent vibration and impact, large pretightening force and the like. The large-range pressure sensor is oversized and cannot be installed; the sensor with smaller size has too small measuring range and does not meet the requirement of bearing capacity required by the application field of vehicle-mounted weighing.

The deformation displacement sensor detects the micro deformation quantity or displacement quantity of the vehicle frame or the vehicle axle and converts the micro deformation quantity or displacement quantity into weight through an algorithm, and the deformation displacement sensor has the defects that the characteristics of the vehicle frame or the vehicle axle material are uncertain, the collected micro deformation quantity or displacement quantity is uncontrollable, the precision is low, and the error is large.

In view of the above problems, the applicant claims: film pressure sensor, application number: 202220939395.1, however, in this application, there is still a problem that the measurement accuracy is not accurate enough, and at the same time, the sensor in this application is installed at the bottom of the spring steel plate of the vehicle, and the influence of the pretightening force at this position leads to a larger final weight data error, and the sensor returns to zero for a longer time or even does not return to zero, and the pretightening force is a larger and unstable force value in daily use, and is smaller and smaller along with the driving process of the vehicle, but does not have a definite force value. Because the factor is the force generated by tightening the nut, and the nut may come loose with the frequency of driving of the vehicle and the road conditions on which it is traveling. The sensor is always affected during this process, so that the force value delivered by the sensor is not a stable and reliable force value. The present utility model therefore proposes an improvement to these problems.

Disclosure of Invention

The utility model aims to: the utility model aims to provide a film differential type wide-range pressure sensor, which can improve the detection precision of load pressure and avoid errors caused by pretightening force on the detection of the sensor.

The technical scheme is as follows: the utility model relates to a film differential type wide-range pressure sensor, which comprises a body, wherein the body is a metal block, a first cavity and a second cavity are respectively arranged in the body, a film is arranged between the first cavity and the second cavity, a first lug is arranged on the end surface of the film, which faces the first cavity, the second cavity and the first lug are concentric, a plurality of uniformly distributed silicon strain gauges are arranged at the juncture of the first lug and the film, and a plurality of silicon strain gauges form a full bridge circuit to be connected with an external circuit board;

the body is installed on the bearing columns on two sides of the vehicle through the outer shell, the outer shell is fixedly connected with the weighing columns on two sides of the vehicle, and the body is arranged in the outer shell and is in interference connection with the outer shell.

Preferably, one half of any of the silicon strain gages is disposed on the film, and the other half is disposed on the bump one.

Preferably, the first bump has a height greater than the thickness of the film and an inner diameter smaller than the inner diameter of the first cavity.

Preferably, the first cavity and the second cavity have the same inner diameter.

Preferably, a step is arranged between the second cavity and the bottom of the body, and a bottom plate is arranged between the step and the bottom of the body.

Preferably, the thickness of the bottom plate is smaller than the thickness of the film.

In practical application, because the bottom of sensor installation's environment is comparatively abominable, and the bottom is more the uneven condition, leads to true weight data distortion, through the setting of bottom plate, ensures that the inside pressure of second cavity receives only the moment that comes from the deformation transmission of the first cavity of top, has reduced external environment's interference.

Preferably, a cover plate for bearing external load is arranged at the top of the first cavity, the top of the cover plate is arc-shaped and is higher than the top of the outer shell, a second lug is arranged at the bottom of the cover plate, and the outer diameter of the second lug is identical to the inner diameter of the first cavity.

Working principle: the internal force transmitted to the film after the external load acts on the cover plate is a bending moment, and the thickness of the film is different due to the fact that the first protruding block is arranged in the center of the film, so that stress distribution at the film with different thickness is different, abrupt change of stress at the juncture of the films with different thickness can be caused, the abrupt change of stress can be detected more clearly by the silicon strain gauge arranged at the position, and the detection precision of the whole sensor is higher.

The beneficial effects are that:

(1) According to the utility model, the first bump is arranged on the film, so that the difference of the film thickness is formed, and the silicon strain gage is arranged at the position where the film thickness changes, so that the strain gage can more clearly detect the stress mutation, and the detection precision of the whole sensor is improved;

(2) The utility model adopts the silicon strain gauge, utilizes the characteristics of high sensitivity and low power consumption of the silicon strain gauge, improves the detection precision, and finally realizes the advantages of high sensitivity output, stable performance, good reliability and repeatability of mass production and micro power consumption;

(3) The sensor is integrally arranged on the bearing columns at two sides of the vehicle, the received direct weight is the weight of goods and carriages, and compared with the traditional sensor arranged at the bottom of a spring steel plate, the sensor can completely avoid the existence of pretightening force and reduce detection errors caused by the existence of pretightening force.

Drawings

FIG. 1 is a front cross-sectional view of the present utility model;

FIG. 2 is a perspective cross-sectional view of the present utility model;

fig. 3 is a schematic view of the present utility model mounted on a vehicle.

Detailed Description

The utility model is further illustrated below in conjunction with specific examples.

As shown in fig. 1, in this embodiment, the device comprises a body 1, wherein the body 1 is a metal block with a first cavity 2 and a second cavity 3 arranged up and down, a thin film 4 is arranged between the first cavity 2 and the second cavity 3, a first bump 5 is arranged on an end surface of the thin film 4 facing one side of the first cavity 2, and the height of the first bump 5 is larger than the thickness of the thin film 4.

In the present embodiment, the first cavity 2, the second cavity 3 and the bump one 5 are concentrically arranged, and the inner diameters of the first cavity 2 and the second cavity 3 are the same, and the inner diameter of the bump one 5 is smaller than the first cavity 2.

In this embodiment, 4 silicon strain gauges are uniformly arranged at the junction of the first bump 5 and the thin film 4, one half of each silicon strain gauge is arranged on the thin film 4, one half is arranged on the first bump 5, and all the silicon strain gauges form a full bridge circuit to be connected with an external circuit board.

In this embodiment, the top of the first cavity 2 is provided with a cover plate 8 for carrying external load, the top of the cover plate 8 is in a circular arc shape and is higher than the top of the external shell, the bottom of the cover plate 8 is provided with a second bump 9, the outer diameter of the second bump 9 is the same as the inner diameter of the first cavity 2, and the cover plate 8 is connected with the first cavity 2 through a buckle between the second bump 9.

In this embodiment, be provided with step 6 between the bottom of second cavity 3 and body 1, be provided with bottom plate 7 between the bottom of step 6 to body 1, the thickness of bottom plate 7 is less than the thickness of film 4, in practical application, because the bottom of sensor is installed the environment comparatively abominable, the bottom is the condition of being more uneven, lead to true weight data distortion, through the setting of bottom plate 7, ensure that the inside pressure of second cavity 3 only receives the moment of deformation transmission from the first cavity 2 of top, external environment's interference has been reduced.

In this embodiment, body 1 passes through the external casing and installs on the spandrel post of vehicle both sides, installs the schematic diagram on the vehicle as shown in fig. 3, and external casing and the weighing column fixed connection of vehicle both sides, body 1 set up in external casing, with external casing interference connection, such setting makes the direct weight that the sensor received be goods and carriage weight, compares in traditional installation in spring steel sheet bottom, can avoid the existence of pretightning force completely, has reduced the detection error that leads to because pretightning force exists.

When the embodiment works, external load acts on the cover plate 8 and then is transferred to the film 4, the internal force is a bending moment, and the center of the film 4 is provided with the first lug 5, so that the thickness of the film 4 is different, and the stress distribution at the film 4 with different thicknesses is different, therefore, the stress at the junction of the films 4 with different thicknesses is suddenly changed, the silicon strain gauge arranged at the position can more clearly detect the stress suddenly change, so that the detection precision of the whole sensor is higher, and meanwhile, due to the arrangement of the bottom plate 7 at the bottom of the second cavity 3, the distortion of detection weight data caused by the unevenness of the installation environment can be avoided, and the detection precision is further improved.

Claims

1. The utility model provides a film differential formula wide range pressure sensor, includes body, its characterized in that: the body (1) is a metal block with a first cavity (2) and a second cavity (3) arranged at the upper part and the lower part of the body respectively, a film (4) is arranged between the first cavity (2) and the second cavity (3), a first lug (5) is arranged on the end face of the film (4) facing the first cavity (2), the second cavity (3) and the first lug (5) are concentric, a plurality of evenly distributed silicon strain gauges are arranged at the juncture of the first lug (5) and the film (4), and a plurality of silicon strain gauges form a full bridge circuit to be connected with an external circuit board;

the body (1) is installed on the bearing columns on two sides of the vehicle through the outer shell, the outer shell is fixedly connected with the weighing columns on two sides of the vehicle, and the body (1) is arranged in the outer shell and is in interference connection with the outer shell.

2. The thin film differential wide-range pressure sensor of claim 1, wherein: one half of any silicon strain gauge is arranged on the film (4), and the other half is arranged on the first bump (5).

3. The thin film differential wide-range pressure sensor of claim 1, wherein: the height of the first protruding block (5) is larger than the thickness of the film (4), and the inner diameter is smaller than the inner diameter of the first cavity (2).

4. The thin film differential wide-range pressure sensor of claim 1, wherein: the first cavity (2) and the second cavity (3) have the same inner diameter.

5. The thin film differential wide-range pressure sensor of claim 1, wherein: a step (6) is arranged between the second cavity (3) and the bottom of the body (1), and a bottom plate (7) is arranged between the step (6) and the bottom of the body (1).

6. The thin film differential wide-range pressure sensor of claim 5, wherein: the thickness of the bottom plate (7) is smaller than that of the film (4).

7. The thin film differential wide-range pressure sensor of claim 1, wherein: the top of first cavity (2) is provided with apron (8) of bearing external load, the top of apron (8) is convex, exceeds the top of outside casing, and the bottom of apron (8) is provided with lug two (9), the external diameter of lug two (9) is the same with the internal diameter of first cavity (2).