A marking device for detecting longitudinal shrinkage rate of plastic pipes

Abstract

The utility model discloses a marking device for detecting the longitudinal shrinkage rate of plastic pipes, which belongs to the technical field of shrinkage rate test of plastic pipes, and comprises a bottom plate, two groups of rotating support assemblies are arranged on the top surface of the bottom plate, and a test specimen is arranged above the two groups of rotating support assemblies, and two height adjustment rods are arranged on the left side of the rotating support assembly, and the two height adjustment rods are arranged in parallel front and back, and a movable sleeve is arranged on the height adjustment rod, and a first positioning member is arranged on the movable sleeve, and a fixed frame is arranged on the right side of the movable sleeve, and a marking pen fixing seat is arranged on the right end of the fixed frame, and a second positioning member is arranged on the marking pen fixing seat, and a marking pen is arranged in the marking pen fixing seat. The marking pen of the utility model remains stationary, and the rotating support assembly drives the test specimen to rotate, and the marking line drawn is a complete circular line, and the spacing of the marking lines will not change during the marking process, and the operation is efficient, convenient, time-saving, and labor-saving, which ensures the distance between the marking lines, improves work efficiency, and improves the accuracy of test data.

Description

Technical Field

[0001] The utility model relates to the technical field of plastic pipe shrinkage rate testing, in particular to a marking device for detecting the longitudinal shrinkage rate of a plastic pipe. Background Art

[0002] The National Standard of the People's Republic of China GB / T 6671-2001 "Determination of Longitudinal Shrinkage of Thermoplastic Pipes" has clear provisions for the requirements of the scriber in Clause 5: "Ensure that the spacing between the two markings is 100mm". Take a pipe section sample of (200±20)mm in length, use a scriber to draw two circumferential markings 100mm apart on the sample, and make one marking at least 10mm away from either end; cut three samples from a pipe, and after the sample is pretreated at (23±2)℃ for at least 2h, measure the spacing between the markings L0 to an accuracy of 0.25mm; adjust the oven temperature to the specified value TR in Appendix A, and put the sample in the oven for the time specified in Appendix A; take the sample out of the oven at the end of the test time, lay it flat on a smooth surface, and when it is completely cooled to (23±2)℃, measure the maximum or minimum distance Li between the markings along the generatrix on the sample surface to an accuracy of 0.25mm.

[0003] The results show that:

[0004] Calculate the longitudinal shrinkage rate R of each sample according to formula (1): li Expressed as a percentage.

[0005] R li =△L / L0×100………………(1)

[0006] Where: △L=|L. -L i |

[0007] L0 is the distance between the two marking lines of the sample before it is placed in the oven, mm;

[0008] L i - The distance between two marking lines measured along the main line after the test, mm;

[0009] Select L i , so that the value of △L is maximized.

[0010] Calculate R for three samples li The arithmetic mean of the longitudinal shrinkage rate R of the pipe is l .

[0011] The longitudinal shrinkage rate is an important indicator of the performance of plastic pipe products. It reflects the stability of the plastic change of the plastic pipe along the longitudinal direction under the influence of heat. Its determination is of great significance to improving the product's ability to withstand changes in temperature, sunlight and other heat sources during use, as well as to increase the product's service life. However, due to the diversity of longitudinal shrinkage determination methods, we often affect the accuracy of the test due to improper operation or lack of attention to the key points during the test.

[0012] Based on the above national standard requirements, the currently used marking device cannot ensure that the spacing between the two markings is 100mm. During the marking process, since there is no device to control the distance on the upper part of the marking device, the distance between the two markings will shift as the sample rotates during the marking process, resulting in the marking circle not being able to overlap, and the distance between the two circumferential markings is uneven, and the distance between the markings is much larger or smaller, which cannot meet the standard requirement of "ensuring that the spacing between the two markings is 100mm", which leads to inaccurate test data for the longitudinal shrinkage rate of the measured pipe, and the result deviation is large. The marking process is time-consuming, labor-intensive, cumbersome and inefficient, which greatly affects the accuracy of the longitudinal shrinkage rate detection. Utility Model Content

[0013] The utility model aims to provide a marking device for detecting the longitudinal shrinkage rate of plastic pipes, so as to solve the problem that the distance between the marking lines of the currently used marking device is too large or too small, resulting in inaccurate detection data of the longitudinal shrinkage rate of the measured pipe, large deviation of the results, and time-consuming, labor-intensive, cumbersome and inefficient marking process.

[0014] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0015] The utility model discloses a marking device for detecting the longitudinal shrinkage rate of a plastic pipe, comprising a bottom plate, two groups of rotating support assemblies are arranged on the top surface of the bottom plate, samples are arranged above the two groups of rotating support assemblies, two height adjustment rods are arranged on the left side of the rotating support assemblies, the two height adjustment rods are arranged in parallel front and back, a movable sleeve is arranged on the height adjustment rod, a first positioning piece is arranged on the movable sleeve, a fixing frame is arranged on the right side of the movable sleeve, a marking pen fixing seat is arranged on the right end of the fixing frame, a second positioning piece is arranged on the marking pen fixing seat, and a marking pen is arranged in the marking pen fixing seat;

[0016] The rotating support assembly includes two mounting seats, which are arranged in parallel on the top surface of the base plate in front and back, a rotating shaft is arranged between the two mounting seats, and two rotating wheels are arranged on the rotating shaft; a handle is arranged on the rotating shaft of one group of the rotating support assemblies.

[0017] Furthermore, the bottom surface of the base plate is provided with adjustable feet.

[0018] Furthermore, a rubber ring is provided on the rotating wheel.

[0019] Furthermore, the bottom surfaces of the two height adjustment rods are each provided with an adjustment component, and the two adjustment components are symmetrically arranged.

[0020] Furthermore, the adjustment assembly includes a fixed seat, which is arranged on the top surface of the base plate, a sliding seat is arranged above the fixed seat, the height adjustment rod is arranged on the top surface of the sliding seat, a connecting block is arranged on the bottom surface of the sliding seat, an adjusting rod is arranged in the cavity of the fixed seat, and the connecting block is threadedly connected to the adjusting rod.

[0021] Furthermore, the top surface of the fixed seat is provided with a slide rail, and the bottom surface of the sliding seat is provided with a slide groove matching the slide rail.

[0022] Furthermore, the slide rail and the slide groove are both configured to be dovetail-shaped.

[0023] Compared with the prior art, the beneficial technical effects of the utility model are:

[0024] The utility model provides two height adjustment rods, the height adjustment rods are connected with a marking pen fixing seat through a fixing frame, the marking pen is installed on the marking pen fixing seat, and the spacing of the marking pens is adjusted by adjusting the spacing between the two height adjustment rods, thereby changing the spacing between two marking lines; when marking, the marking pen remains stationary, and the two sets of rotating support components drive the test piece to rotate, and the marked lines drawn are complete circular lines, and the spacing between the marked lines will not change during the marking process. The operation is efficient, convenient, time-saving and labor-saving, the distance between the marking lines is guaranteed, the work efficiency is improved, and the accuracy of the test data is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The utility model will be further described below in conjunction with the accompanying drawings.

[0026] Figure 1 This is a front view of the marking device for detecting the longitudinal shrinkage rate of plastic pipes according to the utility model;

[0027] Figure 2 It is a side view of the marking device for detecting the longitudinal shrinkage rate of plastic pipes of the utility model;

[0028] Figure 3 It is a top view of the marking device for detecting the longitudinal shrinkage rate of plastic pipes of the utility model;

[0029] Figure 4 It is a three-dimensional structural schematic diagram of the spacing adjustment mechanism of the utility model;

[0030] Figure 5It is a three-dimensional structural schematic diagram of the spacing adjustment mechanism of the utility model from another angle.

[0031] Explanation of the accompanying drawings: 1. Base plate; 2. Mounting seat; 3. Rotating shaft; 4. Rotating wheel; 5. Rubber ring; 6. Handle; 7. Height adjustment rod; 8. Moving sleeve; 9. First positioning member; 10. Fixed frame; 11. Marking pen fixing seat; 12. Second positioning member; 13. Marking pen; 14. Fixed seat; 15. Sliding seat; 16. Adjusting rod; 17. Connecting block; 18. Adjusting foot; 19. Sample. DETAILED DESCRIPTION

[0032] like Figure 1 As shown, a marking device for detecting the longitudinal shrinkage rate of a plastic pipe comprises a bottom plate 1, two groups of rotating support assemblies are installed on the top surface of the bottom plate 1, a sample 19 is placed above the two groups of rotating support assemblies, two height adjustment rods 7 are arranged on the left side of the rotating support assembly, the two height adjustment rods 7 are arranged in parallel front and back, a moving sleeve 8 is slidably sleeved on the height adjustment rod 7, a first positioning member 9 is threadedly connected to the moving sleeve 8, and the moving sleeve 8 is sleeved on the outer side of the height adjustment rod 7. When the moving sleeve 8 moves to a suitable height, the first positioning member 9 is rotated. The end of 9 is pressed against the outer wall of the height adjustment rod 7 to position the movable sleeve 8 to prevent the movable sleeve 8 from sliding and shifting. The right side of the movable sleeve 8 is connected to a fixed frame 10, and a marking pen fixing seat 11 is installed at the right end of the fixed frame 10. A second positioning member 12 is installed on the marking pen fixing seat 11. A marking pen 13 is arranged in the marking pen fixing seat 11. The marking pen 13 is placed in the installation groove at the center of the marking pen fixing seat 11, and then the second positioning member 12 is rotated. The end of the second positioning member 12 is pressed against the outer wall of the marking pen 13 to fix the position of the marking pen 13. Specifically, a scale is arranged above the two fixing frames 10, and the distance between the two fixing frames 10 is displayed by the scale, so as to control the distance between the two marking lines.

[0033] The rotating support assembly includes two mounting seats 2, which are connected to the top surface of the base plate 1 in parallel front and back, and a rotating shaft 3 is rotatably installed between the two mounting seats 2, and two rotating wheels 4 are installed on the rotating shaft 3; a handle 6 is connected to the rotating shaft 3 of one group of the rotating support assemblies; in this embodiment, a handle 6 is connected to the rotating shaft 3 of the rotating support assembly located on the right side.

[0034] Four adjusting feet 18 are installed on the bottom surface of the base plate 1. By setting the adjusting feet 18, the height of the base plate 1 can be adjusted to keep the device in a horizontal position.

[0035] A rubber ring 5 is installed on the rotating wheel 4 .

[0036] The bottom surfaces of the two height adjustment rods 7 are both equipped with adjustment components, such as Figure 3 As shown, the two adjustment components are symmetrically arranged. Figure 4 , 5 As shown, the adjustment assembly includes a fixed seat 14, which is connected to the top surface of the base plate 1, a sliding seat 15 is slidably arranged above the fixed seat 14, the height adjustment rod 7 is connected to the top surface of the sliding seat 15, and the bottom surface of the sliding seat 15 is connected to a connecting block 17, an adjusting rod 16 is rotatably connected in the cavity of the fixed seat 14, the exposed end of the adjusting rod 16 is connected to a rotating operating handle, and the connecting block 17 is threadedly connected to the adjusting rod 16; specifically, a slide rail is arranged on the top surface of the fixed seat 14, and a slide groove matching the slide rail is opened on the bottom surface of the sliding seat 15, and the slide rail and the slide groove are both arranged in a dovetail shape.

[0037] When in use, the adjusting rod 16 is rotated, the adjusting rod 16 drives the connecting block 17 to move, the connecting block 17 drives the sliding seat 15 to move, and the height adjusting rod 7 moves together with the sliding seat 15. In the utility model, the bottoms of the two height adjusting rods 7 are both installed with adjusting components, and the positions of the two height adjusting rods 7 can be adjusted simultaneously or separately. By adjusting the positions of the height adjusting rods 7 and changing the distance between the two height adjusting rods 7, marking lines with different spacings can be drawn, thereby expanding the use range of the device.

[0038] The method of using the utility model is as follows:

[0039] 1. Place the marking device in a suitable test site and adjust the foot 18 to keep the marking device in a balanced position without shaking.

[0040] 2. Cut the sample so that the length of the sample 19 is 200±20 mm, and then place the sample 19 in the center of the four rotating wheels 4.

[0041] 3. Install the marking pen 13 (which can be a pencil, marker, paint pen, etc.) on the marking pen fixing seat 11, and position the marking pen 13 through the second positioning member 12, and use a scale to fix the distance between the two marking pens 13 so that the distance between the two pen tips is 100 mm (to ensure that the distance between the two marking lines is 100 mm).

[0042] 4. Gently turn the handle 6, which drives one set of rotating support components to rotate. At this time, the sample 19 rotates with the rotating wheel 4. After the sample rotates one circle, the marking pen 13 draws two parallel circular marking lines on the sample.

[0043] 5. Remove sample 19 and pre-treat it at (23±2)℃ for at least 2h, then measure the spacing L0 of the marking lines to an accuracy of 0.25mm; adjust the oven temperature to the specified value T in Appendix A. R, Place the sample 19 in the oven and keep it for the time specified in Appendix A. When the test time is up, take the sample out of the oven and place it flat on a smooth surface. When it is completely cooled to (23 ± 2) °C, measure the maximum or minimum distance L between the markings along the generatrix on the surface of the sample 19. i , accurate to 0.25mm; then calculate the longitudinal shrinkage rate R of each sample according to formula (1) li Expressed as a percentage.

[0044] R li =△L / L0×100………………(1)

[0045] Where: △L=|L. -L i |;

[0046] L0 is the distance between the two marking lines of the sample before it is placed in the oven, mm;

[0047] L i - The distance between two marking lines measured along the main line after the test, mm;

[0048] Select L i , so that the value of △L is maximized.

[0049] Calculate R for three samples li The arithmetic mean of the longitudinal shrinkage rate R of the pipe is l .

[0050] In actual testing work, this marking device for detecting the longitudinal shrinkage rate of plastic pipes is very practical. It ensures the distance between marking lines while being efficient, convenient, time-saving and labor-saving. Therefore, it not only improves work efficiency, but also greatly improves the accuracy of test data.

[0051] The embodiments described above are only descriptions of the preferred methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A marking device for detecting longitudinal shrinkage rate of plastic pipes, characterized in that: The invention comprises a bottom plate (1), wherein two groups of rotating support assemblies are arranged on the top surface of the bottom plate (1), and samples (19) are arranged above the two groups of rotating support assemblies; two height adjustment rods (7) are arranged on the left side of the rotating support assemblies, and the two height adjustment rods (7) are arranged in parallel in front and back; a movable sleeve (8) is arranged on the height adjustment rod (7), and a first positioning member (9) is arranged on the movable sleeve (8); a fixing frame (10) is arranged on the right side of the movable sleeve (8); a marking pen fixing seat (11) is arranged at the right end of the fixing frame (10), and a second positioning member (12) is arranged on the marking pen fixing seat (11); and a marking pen (13) is arranged in the marking pen fixing seat (11); The rotating support assembly comprises two mounting seats (2), the two mounting seats (2) are arranged in parallel on the top surface of the base plate (1) in a front-to-back manner, a rotating shaft (3) is arranged between the two mounting seats (2), and two rotating wheels (4) are arranged on the rotating shaft (3); a handle (6) is arranged on the rotating shaft (3) of one group of the rotating support assemblies.

2. The marking device for detecting longitudinal shrinkage rate of plastic pipe according to claim 1, characterized in that: The bottom surface of the base plate (1) is provided with adjustable feet (18).

3. The marking device for detecting longitudinal shrinkage rate of plastic pipe according to claim 1, characterized in that: The rotating wheel (4) is provided with a rubber ring (5).

4. The marking device for detecting longitudinal shrinkage rate of plastic pipe according to claim 1, characterized in that: The bottom surfaces of the two height adjustment rods (7) are both provided with adjustment components, and the two adjustment components are symmetrically arranged.

5. The marking device for detecting longitudinal shrinkage of plastic pipes according to claim 4, characterized in that: The adjustment assembly comprises a fixed seat (14), the fixed seat (14) being arranged on the top surface of the base plate (1), a sliding seat (15) being arranged above the fixed seat (14), the height adjustment rod (7) being arranged on the top surface of the sliding seat (15), a connecting block (17) being arranged on the bottom surface of the sliding seat (15), an adjustment rod (16) being arranged in the cavity of the fixed seat (14), and the connecting block (17) being threadedly connected to the adjustment rod (16).

6. The marking device for detecting longitudinal shrinkage of plastic pipes according to claim 5, characterized in that: The top surface of the fixed seat (14) is provided with a slide rail, and the bottom surface of the sliding seat (15) is provided with a slide groove matching the slide rail.

7. The marking device for detecting longitudinal shrinkage rate of plastic pipe according to claim 6, characterized in that: The slide rail and the slide groove are both configured in a dovetail shape.

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