CN100405033C - Strain Gauge Multi-Component Force Sensor - Google Patents

Abstract

The invention discloses a strain type multi-component force sensor, in which an elastic body with at least three component parts is connected in a ring-shaped shell, and each component part of the elastic body is provided with a force point on the upper end surface, which is symmetrical below the force point There are four transverse holes to reduce the wall thickness of the elastic body. The two holes on each side are paralleled horizontally. A resistance strain gauge is pasted on the center of the two sides of the elastic body wall between the symmetrical holes. Each component The resistance strain gauges in the first part are connected by wires to form a measuring bridge. Each component part of the elastic body is provided with a strip-shaped through hole that makes the component part form a simply supported beam structure. The strip-shaped through-hole is located below the two horizontal parallel holes. The invention has a simple structure, can measure multiple stress points simultaneously, and has accurate measurement and reliable performance, and can also be used for measuring distributed forces such as hedging pressure and extrusion force, and multi-point forces.

Description

Strain Gauge Multi-Component Force Sensor

technical field

The invention relates to a force sensor, in particular to a strain type multi-component force sensor for simultaneous measurement of multiple force points.

Background technique

At present, the strength measurement test of ferrous metal, non-ferrous metal or non-metal products is more advanced by using a cupping testing machine to clamp the sample between the die and the pad die with a corresponding constant force, and use the specified spherical shape The punch applies a transverse punching force to the sample, and the sample is pressed into the die until the sample penetrates cracks. At this time, the depth of the punch pressed into the sample is the cupping value of the sample. The factors that affect the results of the cupping test mainly include the clamping force of the sample, the stamping test force, the depth measurement mechanism of the punch displacement, and the relative position error of the punch, die and pad die. In particular, the clamping force of the sample requires uniform force around it. At present, it is generally reflected that the cracks of the sample in the cupping test appear somewhere around the die, which is caused by uneven clamping force, but it is used for multi-point static force at the same time. The device for accurate measurement is still blank at present, so the calibration of the clamping force has not been solved by corresponding means. In my country's current JJG583-1988 cupping testing machine verification regulations, the verification method adopts the indirect verification method, and only relies on a single-point force sensor to obtain data indirectly. Since the verification part is inconsistent with the use state, its measurement characteristics cannot be determined. , so the detection method of this verification procedure cannot be implemented.

Contents of the invention

The purpose of the present invention is to provide a strain type multi-component force sensor, which can measure the cupping testing machine through multiple stress points at the same time, aiming at the lack of corresponding devices and means for the calibration of the clamping force of the existing cupping testing machine. The clamping force solves the calibration problem of the clamping force of the cupping testing machine, and fills the blank of simultaneous accurate measurement of multi-point static force.

The object of the present invention is achieved in that the annular shell is connected to the base of the elastic body located in the annular shell, the elastic body has at least three component parts, and each component part of the elastic body is provided with a There are four horizontal holes symmetrically arranged under the raised force point, two holes on each side are paralleled horizontally, and a resistance strain gauge is pasted on the center of the two sides of the elastic body wall between the symmetrical holes The resistance strain gauges of each component part are connected by wires to form a measuring bridge. Each component part of the elastic body is provided with a strip-shaped through hole that makes the component part form a simply supported beam structure. The strip-shaped through-hole is located in two horizontally parallel below the hole.

The elastic body and the base are integral structures.

There is a gap between each component part of the elastic body for isolating each component, and the gap penetrates through the base to form a perforation.

The components of the elastomer are equally divided into 360° circles.

Each component part of the elastic body has the same length.

The lower end of the base of the elastic body has a circular step for positioning.

The distances from the stress points on the upper end surfaces of the component parts to the center of the elastic body are equal, and the stress points correspond to the four symmetrical holes.

The elastomer wall between the symmetrical holes has four through holes evenly distributed on the circumference.

Due to the adoption of the above scheme, the annular shell is connected to the base of the elastic body located in the annular shell, the elastic body has at least three component parts, the component parts of the elastic body are equally divided into 360 ° circles, and the parts of each component part equal in length. The upper end surface of each component part of the elastic body is provided with a raised force point, and four transverse holes are symmetrically arranged below the force point to reduce the wall thickness of the elastic body where the resistance strain gauge is installed. The two holes are paralleled horizontally, and a resistance strain gauge is arranged at the center of the two sides of the elastic body wall between the symmetrical holes, and the four resistance strain gauges of each component part are connected by wires to form a measuring bridge. When the sensor measures the clamping force of the cupping testing machine, the clamping force of the cupping testing machine will focus on the raised force points on each component part of the elastic body through the pressure film and the pad die, and pass through each force point Act on the corresponding elastic body of the component part, and measure the force data from each component part through the measuring bridge composed of four resistance strain gauges at the same time, provide accurate value and accuracy for calibrating the clamping force of the cupping test machine The orientation of the force point. Especially below the protruding stress points provided at each component part of the elastic body, four transverse holes are arranged symmetrically, and the elastic body wall between the symmetrical holes has four through holes evenly distributed on the circumference, reducing the Linearity error of elastomers and increasing the sensitivity of the strain response of elastomers under pressure.

There are gaps between the component parts of the elastic body for isolating the components, so that the components do not affect each other during measurement, ensuring accurate values measured from each component.

Each component part of the elastic body is provided with a strip-shaped through hole so that the component part forms a simply supported beam structure, and each component part forms a simply supported beam structure, which is convenient for deformation amplification calculation.

The lower end of the base of the elastic body has a circular step for positioning, and the base is slidably matched with the annular sleeve for positioning on the pad mold of the cupping testing machine, so that the multi-component force sensor can be rotated at a corresponding angle for re-positioning. When measuring, its coaxiality does not change.

The elastic body and the base at its lower end are integrally processed, so that when the elastic body is compressed, only the compressed part elastically deforms, and the elastic body does not produce relative motion, so that the accuracy and reliability of the measurement are guaranteed.

The invention has a simple structure, can measure multiple stress points simultaneously, and has accurate measurement and reliable performance, and can also be used for measuring distributed forces such as hedging pressure and extrusion force, and multi-point forces.

The present invention will be further described below in conjunction with drawings and embodiments.

Description of drawings

Fig. 1 is the structural diagram of a kind of embodiment of the present invention;

Fig. 2 is the A-A direction view of Fig. 1;

Fig. 3 is the structural diagram of another kind of embodiment of the present invention;

Fig. 4 is a position diagram of the present invention when testing the cupping testing machine.

Detailed ways

Referring to FIG. 1 and FIG. 2 , an elastic body 11 with four component parts is arranged in the annular housing 2 , and the circular base 3 of the elastic body 11 is fastened to the annular housing 2 by bolts 9 . The four component parts of the elastic body 11 are equally divided into a 360° circle, and the lengths of each component part are equal. There is a gap 7 for isolating each component between the four component parts of the elastic body 11, and the gap 7 penetrates the base 3 to form a perforation . The lower end of the circular base 3 of the elastic body 11 has a circular step for positioning, and the base 3 and the elastic body 11 are integrally processed and formed as an integral structure. Each component part of the elastic body 11 is provided with a protruding force bearing point 1 on the upper end surface thereof, and the center of the force bearing point 1 is located on the longitudinal symmetry plane of each component part. Four transverse holes 5 are arranged symmetrically below the stress point 1, and two holes on each side are horizontally juxtaposed. The distances from the stress point 1 of each component part to the center of the elastic body 11 are equal, and the stress point 1 corresponds to the four symmetrical holes 5 . The wall thickness of the elastic body between the symmetrical holes 5 is 1 mm, and a strain gauge 6 is attached to the center of the circle on both sides of the wall of the elastic body. Four strain gauges 6 of each component are connected by wires to form a measuring bridge. Four small through holes 4, 10 are evenly distributed on the circumference of the elastic body wall between the symmetrical holes 5, wherein two holes 4 are located on the diameter coordinate X axis, and two holes 10 are located on the diameter coordinate Y axis. Each component portion of the elastic body 11 is provided with a strip-shaped through hole 8 that makes the component portion form a simply supported beam structure. The strip-shaped through-hole 8 is located below the two horizontally juxtaposed holes 5. The length of the strip-shaped through-hole 8 is about greater than the distance between the outer ends of two parallel holes. Since the distance between the upper and lower pressing films of the cupping testing machine is very limited, the height of the elastic body 11 is ≤30mm is the most suitable, and the elastic deformation of the elastic body should not be too large, so as not to change the original working state of the tested machine.

Referring to Fig. 3, this embodiment is compared with the above-mentioned embodiment, except that the elastic body 11 has three component parts, and the three component parts are equally divided into 360° circles, and the rest of the structure and connection methods are the same as the above-mentioned embodiment.

The elastic body 11 of the strain gauge multi-component force sensor can also be provided with more component parts according to the needs of the machine to be tested.

Referring to Fig. 4, when testing the clamping force of the cupping testing machine with the strain-type multi-component force sensor, the strain-type multi-component force sensor is placed between the die 12 and the cushion mold 13 of the cupping test machine, so that the elastic body 11 The base 3 is slidingly matched with the annular sleeve 14 used for positioning on the pad mold 13 . During the test, the die 12 of the cupping testing machine descends, and the clamping force between the die 12 and the pad die 13 acts on the corresponding component elastic body through the stress point 1 of each component part of the elastic body 11, and Through the measurement bridge composed of four resistance strain gauges, the data of the force is measured from each component part at the same time, providing accurate value and orientation of the force point for calibrating the clamping force of the cupping test machine. Raise the die 12, the position of the annular sleeve 14 for positioning remains unchanged, and rotate the strain gauge multi-component force sensor by a certain angle. At this time, the orientation of each force point 1 changes accordingly, and the die 12 is lowered to apply the For the same clamping force, measure the force data of each component under this angle. In the same way, according to this method, the clamping force of each component part under different angles is sequentially measured, and the non-uniformity (orientation error) of the clamping force of the cupping testing machine can be obtained. The clamping force of the testing machine is corrected.

Claims (5)

1. strain type force sensor for multiple components, comprise annular shell (2) and resistance strain gage (6), it is characterized in that: the base (3) of the elastic body (11) that described annular shell (2) is interior with being located at annular shell (2) is connected, elastic body (11) has three component parts at least, component parts etc. divide 360 ° of circles, the equal in length of each component part of elastic body (11), the upper surface of each component part of elastic body (11) is equipped with the stress point (1) of a projection, stress point (1) below is provided with four transverse holes (5) symmetrically, two hole horizontals of each side are arranged side by side, the circle centre position on the elastomeric walls two sides between the hole (5) of symmetry respectively posts a resistance strain gage (6), the resistance strain gage of each component part (6) connects to form a measuring bridge by lead, each component part of elastic body (11) is equipped with and makes component part form the strip through-hole (8) of simple beam structure, and strip through-hole (8) is positioned at the below in two levels hole arranged side by side.

2. strain type force sensor for multiple components according to claim 1 is characterized in that: described elastic body (11) is an one-piece construction with base (3).

3. strain type force sensor for multiple components according to claim 1 is characterized in that: be useful on the gap (7) that isolates each component part between each component part of described elastic body (11), this gap is run through base (3) and is formed perforation.

4. strain type force sensor for multiple components according to claim 1 is characterized in that: base (3) lower end of described elastic body (11) is useful on the step cutting pattern of location.

5. strain type force sensor for multiple components according to claim 1 is characterized in that: the elastomeric walls between the hole of described symmetry (5) is being evenly distributed in four through holes (4,10).

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