CN110849730A

CN110849730A - Clamp device for controlling constant boundary of sample in stretching

Info

Publication number: CN110849730A
Application number: CN201911247020.8A
Authority: CN
Inventors: 刘兵; 袁嫣红; 孙凡平
Original assignee: Zhejiang Sci Tech University ZSTU
Current assignee: Zhejiang Sci Tech University ZSTU; Zhejiang University of Science and Technology ZUST
Priority date: 2019-12-09
Filing date: 2019-12-09
Publication date: 2020-02-28

Abstract

The invention relates to a clamp device for keeping a constant boundary of a sample in a stretching experiment process, and belongs to the technical field of measuring devices. Control sample constant boundary's fixture device in tensile, its characterized in that: the clamp comprises a moving part, wherein a force sensor is arranged on the moving part, and a first clamp connection area and a second clamp connection area are arranged on two sides of the force sensor; a first clamp is connected to the first clamp connection area, a second clamp is connected to the second clamp connection area, and a third clamp is connected to the force sensor; the clamping opening of the first clamp, the clamping opening of the second clamp and the clamping opening of the third clamp are positioned on the same axis, a fourth clamp is correspondingly arranged, and the axis where the clamping opening of the first clamp is positioned and the axis where the clamping opening of the fourth clamp is positioned are mutually parallel lines.

Description

Clamp device for controlling constant boundary of sample in stretching

Technical Field

The invention relates to a clamp device for keeping a constant boundary of a sample in a stretching experiment process, and belongs to the technical field of measuring devices.

Background

In the study of the mechanical properties of fabrics and related large deformation amount materials, different degrees of test stretching of samples are often required. The boundary conditions of the sample to be controlled during the experiment are constant tension or constant boundary. The clamp and clamping mode for clamping the fabric during the experiment have important influence on the experimental result. The samples tend to "waisting" when stretched due to the lack of a fixed longitudinal boundary condition. Thus, the obtained experimental result has no comparative value with the theoretical analysis. Similar problems exist in the tensile test of many materials, for example, when a steel material is stretched, a strain gauge for acquiring data is usually attached to the middle position of a sample, so that the influence of boundary conditions on a measured value can be reduced. But for the stretching of the fabric, the deformation quantity is large, and a device for measuring the strain is not easy to be pasted; and the stretching distance is long, so that a device capable of dynamically following the boundary of the fixed sample is difficult to design. Therefore, the fixation of the boundary conditions of the fabric and other materials with large deformation amount in the stretching experiment is a relatively difficult problem.

In order to solve the problem of huge measurement errors caused by the waist shrinkage phenomenon in the fabric stretching experiment, the invention hopes to provide a fixture device for controlling the constant boundary of a sample in stretching.

Disclosure of Invention

In order to solve the problems, the invention provides a fixture device for controlling the constant boundary of a sample in stretching. The specific technical scheme is as follows:

the clamp device for controlling the constant boundary of a sample in stretching comprises a moving part, wherein a force sensor is arranged on the moving part, and a first clamp connection area and a second clamp connection area are arranged on two sides of the force sensor; a first clamp is connected to the first clamp connection area, a second clamp is connected to the second clamp connection area, and a third clamp is connected to the force sensor; the clamping opening of the first clamp, the clamping opening of the second clamp and the clamping opening of the third clamp are always positioned on the same axis, a fourth clamp is correspondingly arranged, and the axis where the clamping opening of the first clamp is positioned and the axis where the clamping opening of the fourth clamp is positioned are mutually parallel lines.

And a force sensor is arranged at the midpoint of the moving part. The force sensor positioned at the central position can ensure that the force sensor is stressed symmetrically in the movement normal direction in the measurement process, so that the errors in measurement can be reduced after mutual offset, and the truest experimental data can be obtained.

The first clamp and the second clamp are symmetrically arranged on two sides of the third clamp, and the first clamp and the second clamp are the same in length. The arrangement can keep two sides balanced in the stretching process, the condition that the axis where the first clamp is located is not parallel to the axis where the fourth clamp is located is avoided, and meanwhile, the measuring area can be controlled to be kept at the central position of the fabric.

The first clamp and the third clamp are not in contact with each other, and the second clamp and the third clamp are not in contact with each other. The larger the difference in length between the first clamp and the second clamp relative to the third clamp, and the smaller the gap between the different clamps, the more accurate the tension of the fabric as it is stretched is measured by the force sensor.

The length of the fourth clamp is not less than the total length of the first clamp, the second clamp and the third clamp. Therefore, according to the measurement requirements of samples with different sizes, the lengths of the first clamp, the second clamp and the third clamp are changed, and the fourth clamp can be prevented from being replaced.

The moving part and the fourth clamp are fixed on the same sliding rail to move, and the stability of the fabric during stretching can be ensured by moving on the same sliding rail.

When the device is used, one end of the fabric is clamped through the first clamp, the second clamp and the third clamp, the other end of the fabric is clamped through the fourth clamp, the fabric is stretched, and the effective width of the measured sample is the width of the third clamp. The first clamp, the second clamp and the third clamp keep synchronous motion close to each other on the same axis but do not influence the synchronous motion, and the first clamp and the second clamp are utilized to keep the boundary of the measuring area unchanged by following the movement of the samples. And the larger the length of the first clamp and the second clamp is, the smaller the waist shrinkage phenomenon of the fabric in the limited width is, and the more accurate the measurement value is.

Drawings

FIG. 1 is a schematic top view of a fixture apparatus for controlling the constant boundary of a sample while stretching, with a fabric sandwiched therebetween;

FIG. 2 is a schematic perspective view of a fixture apparatus for controlling the constant boundary of a sample during stretching with a fabric sandwiched therebetween;

fig. 3 is a schematic perspective view of a fixture for controlling the constant boundary of a sample during stretching.

Description of reference numerals:

1. a moving part; 2. a force sensor; 3. a first clamp connection region; 4. a second clamp connection region; 5. a first clamp; 6. a second clamp; 7. a third clamp; 8. a fabric; 81. a first boundary; 82. a second boundary; 83. a measurement area; 84. a third boundary; 85. a fourth boundary; 9. a fourth clamp; 10. a slide rail.

Detailed Description

The following further describes a fixture device for controlling the constant boundary of a sample in stretching with reference to the attached drawings of the specification.

A clamping device for controlling the constant boundary of a sample in stretching comprises a moving part 1 arranged on a slide rail 10, wherein the moving part 1 can slide along the slide rail 10. The middle point position of the moving component 1 is also provided with a CY1-50N type force sensor 2 with the length of 65mm x 50mm, the force sensor 2 does not deform in the stretching process, a third clamp 7 with the length of 80mm is fixedly connected to the force sensor 2, and the force sensor 2 and the third clamp 7 move synchronously all the time in the stretching process. The third clamp 7 does not contact the slide rail 10 during sliding, so as to ensure that no additional friction is generated between the third clamp 7 and the slide rail 10 during sliding.

The two sides of the force sensor 2 are respectively provided with a first clamp connection area 3 and a second clamp connection area 4, and the lengths of the first clamp connection area 3 and the second clamp connection area 4 are both 120 mm. A first clamp 5 with a length of 100mm is fixedly connected to the first clamp connection region 3, and a second clamp 6 with a length of 100mm is fixedly connected to the second clamp connection region 4. The first clamp connecting area 3 and the second clamp connecting area 4 are the same in length, and the first clamp 5 and the second clamp 6 are the same in length, so that the balance of the two sides of the moving part 1 can be kept in the stretching process, and meanwhile, the measuring area can be controlled to be kept at the central position of the cloth. In addition, a gap of 1-1.5mm is reserved between the first clamp 5 and the third clamp 7, a gap of 1-1.5mm is also reserved between the second clamp 6 and the third clamp 7, the gap can ensure that different clamps can operate independently, and extra friction force cannot be generated between different clamps.

A piece of cloth with the thickness of 120mm by 240mm is taken, and the weaving raw material is spandex coated yarn with high elastic property. One end of the first clamp 5, one end of the second clamp 6 and one end of the third clamp 7 are fixed through the first clamp 5, the second clamp 6 and the third clamp 7, in order to ensure that the clamping opening of the first clamp 5, the clamping opening of the second clamp 6 and the clamping opening of the third clamp 7 are always in the same axis in the stretching process, the first clamp 5, the second clamp 6 and the third clamp 7 are only clamps with different lengths, and the front end of the first clamp 5, the front end of the second clamp 6 and the front end of the third clamp 7 are kept flush. Corresponding to the first clamp 5, the second clamp 6 and the third clamp 7, a fourth clamp 9 with a length of 300mm is further provided. The fourth clamp 9 is fixed at one end of the slide rail 10, and the axis where the clamping opening of the fourth clamp 9 is located is parallel to the axis where the clamping opening of the first clamp 5 is located. The other end of the cloth is fixed by a fourth clamp 9.

After the cloth is fixed, the sliding motion part 1 stretches the cloth. During the stretching process, the cloth material has a waist-shrinking phenomenon, the first boundary 81 and the fourth boundary 85 begin to bend inward, the second boundary 82 and the third boundary 84 maintain an approximately straight state (the second boundary 82 and the third boundary 84 are both virtual boundaries, only for explaining the area where the cloth material hardly shrinks during the stretching process), and at this time, the width between the second boundary 82 and the third boundary 84 is the length of the third clamp 7. After stretching to 200mm, the reading of the force sensor was 5.6N.

The above-mentioned embodiments are only used for explaining the inventive concept of the present invention, and do not limit the protection of the claims of the present invention, and any insubstantial modifications of the present invention using this concept shall fall within the protection scope of the present invention.

Claims

1. Control sample constant boundary's fixture device in tensile, its characterized in that: the clamp comprises a moving part, wherein a force sensor is arranged on the moving part, and a first clamp connection area and a second clamp connection area are arranged on two sides of the force sensor; a first clamp is connected to the first clamp connection area, a second clamp is connected to the second clamp connection area, and a third clamp is connected to the force sensor; the clamping opening of the first clamp, the clamping opening of the second clamp and the clamping opening of the third clamp are positioned on the same axis, a fourth clamp is correspondingly arranged, and the axis where the clamping opening of the first clamp is positioned and the axis where the clamping opening of the fourth clamp is positioned are mutually parallel lines.

2. The apparatus of claim 1, wherein the grip is configured to control the constant boundary of the sample during stretching, and further comprising: and a force sensor is arranged at the midpoint of the moving part.

3. The apparatus of claim 1, wherein the grip is configured to control the constant boundary of the sample during stretching, and further comprising: the first clamp and the second clamp are symmetrically arranged on two sides of the third clamp, and the first clamp and the second clamp are the same in length.

4. The apparatus of claim 1, wherein the grip is configured to control the constant boundary of the sample during stretching, and further comprising: the first clamp and the third clamp are not in contact with each other, and the second clamp and the third clamp are not in contact with each other.

5. The apparatus of claim 1, wherein the grip is configured to control the constant boundary of the sample during stretching, and further comprising: the length of the fourth clamp is not less than the total length of the first clamp, the second clamp and the third clamp.

6. The apparatus of claim 1, wherein the grip is configured to control the constant boundary of the sample during stretching, and further comprising: the moving part and the fourth clamp move on the same slide rail.