CN218780591U

CN218780591U - Structure for sticking strain gauge

Info

Publication number: CN218780591U
Application number: CN202223106071.9U
Authority: CN
Inventors: 吕鹏; 梁朝阳; 张鑫; 李论
Original assignee: Shaanxi Zhuoyu Technology Service Co ltd
Current assignee: Shaanxi Zhuoyu Technology Service Co ltd
Priority date: 2022-11-23
Filing date: 2022-11-23
Publication date: 2023-03-31
Anticipated expiration: 2032-11-23

Abstract

The application relates to the field of strain gauges, and specifically provides a structure for sticking a strain gauge, which comprises a breather pipe, an elastic cavity and a delay film. The one end and the elasticity cavity intercommunication of breather pipe, seamless connection between the breather pipe edge and the elasticity cavity's blow vent edge, the delay membrane separates the elasticity cavity for middle cavity and side cavity, is provided with the gas passage that can open under the pressure effect on the delay membrane, is provided with the aperture that is used for adsorbing the foil gage on the side that the breather pipe one end was kept away from to the elasticity cavity, and the one end and the breather pipe intercommunication of middle cavity. The elastic cavity is divided by the delay film, so that under the action of the middle cavity, the middle of the strain gauge is firstly in close contact with the measuring point of the tested piece, then under the action of the side cavity, the rest part of the strain gauge is in close contact with the measuring point of the tested piece, and air between the strain gauge and the measuring point of the tested piece is exhausted from inside to outside, so that no air bubble is generated between the strain gauge and the measuring point of the tested piece.

Description

Structure for sticking strain gauge

Technical Field

The application relates to the field of strain gauges, in particular to a structure for adhering strain gauges.

Background

The strain gauge is an element for measuring strain, which is formed by a sensitive grid and the like, and can convert the strain amount of a tested piece into the resistance variation amount. The phenomenon that the resistance value of a conductor or a semiconductor material changes correspondingly when the conductor or the semiconductor material is mechanically deformed under the action of external force is utilized. A typical strain gauge is fabricated by attaching a sensing grating to a plastic film called a substrate, and then covering the substrate with a film to form a laminate structure.

When the strain gauge is used, the strain gauge is firmly and tightly adhered to a measuring point of a tested piece, after the tested piece is stressed, the resistance of the sensitive grid changes due to the strain of the measuring point and the deformation of the sensitive grid, the resistance change is measured by a special instrument and converted into a strain value of the measuring point, and the strain measurement is realized. The accuracy and sensitivity of the strain measurement is closely related to whether the strain gage is in intimate contact with the point at which the device is being tested.

When the strain gauge is actually adhered, after glue is smeared on the adhering surface of the strain gauge, the strain gauge is directly pressed at a measuring point by hand; or covering the polytetrafluoroethylene material sheet on the strain gauge, and pressing by using hands or a weight to ensure that the sticking surface of the strain gauge is fixedly connected with the measuring point in an adhesion manner; or by using a device disclosed in a utility model patent having an issued publication number of "CN 217582760U", a utility model name of "a portable device for sticking a strain gauge". However, because the influence of air between the strain gauge pasting surface and the measuring point is not considered during pasting, air bubbles are formed between the strain gauge pasting surface and the measuring point of the tested piece during pasting, so that the contact between the strain gauge and the measuring point of the tested piece is not tight, and the detection sensitivity and accuracy of the strain gauge are poor.

As described above, the conventional method and apparatus for bonding a strain gauge have a problem that air bubbles are likely to be generated between the strain gauge and a test point.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a not enough to among the above-mentioned prior art, provide a structure of pasting foil gage to solve the problem that produces the bubble easily between foil gage and tested piece measurement station department when pasting that exists in the current method or the device of pasting the foil gage.

In order to achieve the above object, the utility model adopts the following technical scheme:

the application provides a paste structure of foil gage, this structure includes breather pipe, elasticity cavity, delay membrane. One end of the vent pipe is communicated with the elastic cavity, and when the inflatable air bag is used, the other end of the vent pipe is connected with the pumping and inflating equipment to inflate or pump out gas in the elastic cavity. The edge of the vent pipe is connected with the edge of the vent hole of the elastic chamber in a seamless mode so as to ensure good air tightness. The elastic chamber is divided into a middle chamber and a side chamber by the delay film, and the delay film is provided with a gas channel which can be opened under the action of pressure; therefore, the middle chamber is filled with air firstly during inflation, and when the pressure is higher, the air flows into the side chamber from the middle chamber, so that the pressure of the side chamber is increased. The side surface of the elastic cavity far away from one end of the vent pipe is provided with a small hole for absorbing the strain gauge; when the gas in the elastic cavity is pumped out, negative pressure is formed in the elastic cavity, and the strain gauge is adsorbed at the small hole under the action of atmospheric pressure. One end of the middle cavity is communicated with the vent pipe, and the other end of the middle cavity is provided with a small hole; to ensure that first the middle chamber presses the middle of the strain gage.

Preferably, the gas passages are slit structures, the number of which is greater than 6.

Preferably, the gas passage has a crisscross slit structure, and the plurality of slit structures are uniformly distributed on the retardation film.

Alternatively, the retardation film is a planar film structure, and the number of the side chambers is an even number of two or more.

Optionally, the retardation film is a cylindrical film structure, the middle chamber is an inner portion of the cylindrical film structure, the side chambers are one, and the side chambers are portions between the cylindrical film structure and an inner wall of the elastic chamber.

Preferably, the shape of the elastic chamber is spherical or a cuboid with a curved side surface, and the curved surface is the surface of the elastic chamber far away from one end of the vent pipe.

Preferably, the middle chamber and the side chambers are provided with small holes.

Preferably, a protective layer is fixedly arranged on one side of the elastic chamber away from the vent pipe in a bonding mode, and the protective layer is a polytetrafluoroethylene layer with the thickness of 0.5-2.0 mm.

Preferably, the protective layer covers the small holes, through holes are formed in the protective layer, and the positions of the through holes correspond to the small holes one by one.

Preferably, the materials of the retardation film and the elastic chamber are rubber.

Preferably, the vent pipe is a plastic pipe or a metal pipe.

Preferably, the curved surface of the resilient chamber provided with the aperture corresponds to a radius of curvature greater than 90cm.

Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses use delay film to separate the elasticity cavity for middle cavity and side cavity. The delay film is provided with a plurality of gas channels, the gas channels are closed when the delay film is not inflated, the gas channels are opened under the action of pressure difference when the pressure of the middle chamber is larger, gas passes through the gas channels, and the pressure of the side chamber begins to rise, so that the effect of delaying inflation of the side chamber is achieved. Therefore, the elastic cavity is divided by the delay film, so that the pressure of the middle cavity is firstly increased during inflation, and then the pressure of the side cavity is increased, so that when the strain gauge is adhered to one side of the elastic cavity, which is far away from the vent hole, under the action of the middle cavity, the middle of the strain gauge is firstly in close contact with the measuring point of the tested piece, then under the action of the side cavity, the rest part of the strain gauge is then in close contact with the measuring point of the tested piece, so that air between the strain gauge and the measuring point of the tested piece is discharged from inside to outside, and air bubbles are not generated between the strain gauge and the measuring point of the tested piece.

Drawings

Fig. 1 is a schematic view of a structure of a bonded strain gauge provided by the present invention;

fig. 2 is a schematic diagram of a retardation film in a structure of a bonded strain gauge according to the present invention.

An icon: 1-a breather pipe; 2-a flexible chamber; 3-retardation film.

Detailed Description

In order to make the implementation of the present invention clearer, the following detailed description will be made with reference to the accompanying drawings.

The utility model provides a paste structure of foil gage, as shown in figure 1, the device includes breather pipe 1, elasticity cavity 2, delay membrane 3. The vent pipe 1 is in a shape of a hard pipe, and specifically, the vent pipe 1 is a plastic pipe or a metal pipe. The elastic chamber 2 can be made of rubber, only the side far away from one end of the vent pipe 1 can be made of rubber, the rest parts can be made of hard materials such as hard plastics and hard alloy, and the hard material parts are in seamless connection with the rubber contact parts to ensure air tightness. The material of the retardation film 3 is an elastic material such as rubber. The rubber in the present application refers to one of cis-polyisoprene, cis-1, 4-polyisoprene, styrene-butadiene rubber, cis-1, 4-polybutadiene, chloroprene rubber, nitrile rubber and polysulfide rubber. Therefore, the pressure of the elastic chamber 2 to the transformer is in direct proportion to the pressure inside the elastic chamber, meanwhile, the delay film 3 can prevent gas from passing through when the pressure difference between the two sides is small, and can allow the gas to pass through when the pressure difference between the two sides is large, and therefore the delay effect is achieved. One end of the vent pipe 1 is communicated with the elastic cavity 2, and when the device is used, the other end of the vent pipe 1 is connected with a pumping and inflating device to inflate or pump the gas in the elastic cavity 2 into the elastic cavity 2. The edge of the vent pipe 1 is connected with the edge of the vent hole of the elastic chamber 2 in a seamless mode so as to ensure good air tightness.

The delay film 3 divides the elastic chamber 2 into a middle chamber and a side chamber, and a gas channel which can be opened under the action of pressure is arranged on the delay film 3; therefore, the middle chamber is filled with gas firstly during inflation, and when the pressure is higher, the gas flows into the side chamber from the middle chamber, so that the pressure of the side chamber is increased. Specifically, the gas channel is a slit structure, for example, a crisscross slit structure shown in fig. 2, when the pressure on the two sides is low, the gas channel is in a closed state, so that the gas on the two sides does not flow through, and when the pressure on the two sides is high, the elastic material around the slit leaves the original position under the action of the pressure, and a large gap is reserved, so that the gas channel is opened, so that the gas does not enter the side chambers immediately after entering the middle chamber, and a delay effect is formed. The number of the slit structures may be plural, and the plural slit structures may be uniformly distributed on the retardation film 3, or may be non-uniformly distributed on the retardation film 3, and preferably, the plural slit structures are uniformly distributed on the retardation film 3.

The side surface of the elastic chamber 2 far away from one end of the breather pipe 1 is provided with a small hole for absorbing the strain gauge; when the gas in the elastic cavity 2 is pumped out, negative pressure is formed in the elastic cavity, and the strain gauge is adsorbed at the small hole under the action of atmospheric pressure. Preferably, the middle chamber and the side chambers are provided with small holes, so that the strain gauge is better attached to the side surface of the elastic chamber 2, and the strain gauge is more accurately pressed when being inflated; more preferably, the apertures are distributed in the elongated region in the middle of the above-mentioned side of the elastic chamber 2. The strip-shaped area mainly considers that the existing strain gauge is strip-shaped, and is not an essential feature, that is, the shape of the area where the small holes are distributed depends on the shape of the strain gauge, preferably, the area of the area where the small holes are distributed is similar to the shape of the strain gauge, specifically, the area of the area where the small holes are distributed needs to be smaller than the area of the strain gauge, so that the strain gauge can be adsorbed on the outer wall of the elastic chamber 2 under the action of the negative pressure and the atmospheric pressure inside the elastic chamber 2, and the pasting operation of the strain gauge is further performed. One end of the middle chamber is communicated with the breather pipe 1, and the other end of the middle chamber is provided with a small hole; to ensure that first the middle chamber presses the middle of the strain gage.

The shape of the elastic chamber 2 is spherical or a cuboid with a curved side surface, and the curved surface is the surface of the elastic chamber 2 far away from one end of the vent pipe 1. The curvature radius corresponding to the curved surface provided with the small holes in the elastic chamber 2 is larger than 90cm, so that the curvature is larger, when the strain gauge is adsorbed on the outer wall of the elastic chamber 2, the deformation degree of the strain gauge is extremely small, and the strain gauge cannot be damaged; meanwhile, due to the curved surface, when the strain gauge is contacted with the measuring point of the tested piece, the middle position of the strain gauge is contacted first, and then the periphery of the strain gauge is contacted, so that air between the strain gauge and the measuring point of the tested piece can be discharged, and air bubbles are not formed.

The retardation film 3 may be a flat film structure or a curved film structure. The delay film 3 is a plane film structure, the number of the side cavities is an even number more than two, the side cavities are symmetrically distributed on two sides of the middle cavity or the periphery of the middle cavity, so that the middle cavity applies pressure to the strain gauge first, the side cavities symmetrically apply pressure to the strain gauge, air between the strain gauge and a tested part measuring point is uniformly discharged, and air bubbles are not easily generated due to uneven stress during air discharge. The retardation film 3 is a curved film structure, preferably, a cylindrical film structure, the middle chamber is an inner part of the cylindrical film structure, the side chambers are one, and the side chambers are a part between the cylindrical film structure and the inner wall of the elastic chamber 2. Therefore, the pressure around the strain gauge of the side chamber is more easily ensured to be uniform, so that the air between the strain gauge and the measuring point of the tested piece is uniformly discharged, and bubbles are not easily generated due to uneven stress during air discharge.

Preferably, the elastic chamber 2 is fixedly provided with a protective layer in a bonding manner on the side away from the vent pipe 1, and the protective layer is a polytetrafluoroethylene layer with the thickness of 0.5-2.0mm, so that the elastic chamber can have better deformation, and the protective layer is completely attached to the outer wall of the elastic chamber 2. Preferably, the protective layer covers the small holes, the through holes are formed in the protective layer, and the positions of the through holes correspond to the small holes one by one, so that the protective layer does not affect the adsorption effect on the strain gauge. And the redundant glue on the pasting surface of the strain gauge flows out from the edge of the strain gauge in the pasting and extruding process. The protective layer is made of polytetrafluoroethylene, and glue is adhered to the protective layer and then is easily removed, so that the glue cannot be adhered to the outer wall of the elastic cavity 2 in the adhering process.

When the device is used, air in the elastic cavity 2 is pumped out through the other end of the vent pipe 1, negative pressure is formed in the elastic cavity 2, the strain gauge is adsorbed at a small side hole of the elastic cavity 2 far away from the vent pipe 1 by using atmospheric pressure, air pumping is kept, and glue is coated on one side of the strain gauge far away from the elastic cavity 2, namely the sticking surface of the strain gauge. And then, approaching and contacting the strain gauge with a measuring point of the tested piece, wherein only the middle position of the strain gauge is contacted during the contact, after the position is determined, the position of the device is not moved, the elastic chamber 2 is inflated through the other end of the vent pipe 1, so that the pressure inside the elastic chamber 2 is increased, the strain gauge is pressurized, after the strain gauge is completely pressurized (the strain gauge is completely wrapped by the wall of the elastic chamber 2), the device is kept still for 3-5s, the gas inside the elastic chamber 2 is discharged through the other end of the vent pipe 1, the strain gauge is adhered to the measuring point of the tested piece, and the device is removed. In the process of pressing the strain gauge, due to the existence of the delay film 3, the pressure of the middle chamber rises firstly, so that the middle position of the strain gauge is pressed firstly, then the side chambers press the strain gauge, the periphery of the strain gauge is in close contact with a measured point of a tested piece, therefore, the air between the strain gauge and the measured point of the tested piece is discharged by the pressing mode from the middle of the strain gauge to the periphery, bubbles are not easy to form, the contact between the strain gauge and the measured point of the tested piece is tight, and the detection sensitivity and the accuracy of the strain gauge are high. The elastic chamber 2 is deformed in the process of inflation and air exhaust, the deformation amount is not large, and for example, the elastic chamber 2 cannot collapse in the process of air exhaust.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a paste structure of foil gage, a serial communication port, the structure includes breather pipe, elasticity cavity, delay membrane, the one end of breather pipe with elasticity cavity intercommunication, the breather pipe edge with seamless connection between elasticity cavity's the blow vent edge, delay membrane will the elasticity cavity is separated for middle cavity and side cavity, be provided with the gas passage that can open under the pressure effect on the delay membrane, the elasticity cavity is kept away from be provided with the aperture that is used for adsorbing the foil gage on the side of breather pipe one end, the one end of middle cavity with the breather pipe intercommunication, the other end of middle cavity is provided with the aperture.

2. The structure of a pasting strain gage of claim 1 wherein the gas passages are slit structures, the number of which is greater than 6.

3. The structure of a pasting strain gage of claim 2, wherein the gas passage is a criss-cross slit structure, and the plurality of slit structures are uniformly distributed on the retardation film.

4. The structure of pasting strain gage of claim 3, wherein the retardation film is a flat film structure, and the number of the side chambers is an even number of two or more.

5. The structure of pasting a strain gage of claim 3, wherein the retardation film is a cylindrical film structure, the middle chamber is an inner portion of the cylindrical film structure, the side chambers are one, and the side chambers are a portion between the cylindrical film structure and an inner wall of the elastic chamber.

6. The structure for sticking the strain gage as claimed in any one of claims 1 to 5, wherein the shape of the elastic chamber is a sphere or a cuboid having a curved side surface, the curved side surface being a surface of the elastic chamber far away from one end of the vent pipe.

7. The structure of pasting strain gage as defined in any one of claims 1-5, wherein said small holes are provided on both said middle chamber and said side chambers.

8. The structure of pasting strain gage as claimed in any one of claims 1-5, wherein the side of the elastic chamber away from the air pipe is fixedly bonded with a protective layer, and the protective layer is a polytetrafluoroethylene layer with a thickness of 0.5-2.0 mm.

9. The structure of pasting strain gages as in claim 8, wherein the protective layer covers the small holes, through holes are provided in the protective layer, and the positions of the through holes correspond to the small holes one by one.

10. The structure of an adhesive strain gage of any one of claims 1-5 wherein the material of the retardation film and the elastic chamber is rubber.