A testing device for the ultimate performance of plastic sheets

Abstract

The present invention provides a testing device for the ultimate performance of plastic sheets, comprising: a base; a frame, disposed on the upper surface of the base and fixedly connected to the base; a central axis, disposed at the upper part of the frame, with the axis perpendicular to the frame and parallel to the upper surface of the base; an impact pendulum, connected to the central axis through a bearing; an anti-secondary impact device, disposed at the circumference of the impact pendulum around the central axis, and fixedly connected to the impact pendulum; a test bench, disposed on the upper surface of the base and fixedly connected to the base; characterized in that an impact edge is provided at the lower end of the impact pendulum, and the impact edge is fixedly connected to the impact pendulum; a release handle is provided between the impact pendulum and the frame, the anti-secondary impact device is used to prevent secondary impact on the plastic sheet during the test, and an impact position calibration device is provided on the test bench; by setting the anti-secondary impact device and the impact position calibration device, the present invention avoids secondary impact on the plastic sheet and realizes calibration of the impact position of the impact edge.

Description

Technical Field

[0001] The present invention belongs to the field of precision instruments, and particularly relates to a device for testing the ultimate performance of plastic sheets. Background Art

[0002] In modern life, plastic sheets are widely distributed. They are very common in applications ranging from small toys to large automotive parts. During the use, transportation, and storage of industrial products and daily necessities made of plastic sheets after leaving the factory, impacts from the external environment are inevitable. Impact tests have become an important part of the environmental adaptability testing and reliability testing of plastic products.

[0003] Generally, the testing of the ultimate performance of plastic sheets is completed using an impact testing machine. The test often uses the method of gradually increasing the impact energy to impact the plastic sheets. When the initial impact energy in the test is small, the traditional impact testing machine has the situation of secondary impact on the plastic sheets used in the test, and the secondary impact affects the accuracy of the test data. On the other hand, due to problems such as the machining accuracy and service life of some impact test devices, there are also deviations in the impact position of the impact blade, resulting in test data errors.

[0004] To solve the above problems, the present invention has set up an anti-secondary impact device and an impact position calibration device, avoiding the secondary impact on the plastic sheets and achieving the calibration of the impact position of the impact blade. Summary of the Invention

[0005] The present invention aims to provide a device for testing the ultimate performance of plastic sheets to overcome the above deficiencies. By setting up an anti-secondary impact device and an impact position calibration device, the secondary impact on the plastic sheets is avoided, and the calibration of the impact position of the impact blade is achieved.

[0006] The present invention provides a device for testing the ultimate performance of plastic sheets, including:

[0007] A base;

[0008] A frame, arranged on the upper surface of the base and fixedly connected to the base;

[0009] A central axis, arranged at the upper part of the frame, with its axis perpendicular to the frame and parallel to the upper surface of the base;

[0010] An impact pendulum, connected to the central axis through a bearing;

[0011] An anti-secondary impact device, arranged at the circumference of the impact pendulum around the central axis, and fixedly connected to the impact pendulum;

[0012] A test bench, arranged on the upper surface of the base and fixedly connected to the base;

[0013] It is characterized in that an impact blade is provided at the lower end of the impact pendulum, and the impact blade is fixedly connected to the impact pendulum; a release handle is provided between the impact pendulum and the frame, and the anti-secondary impact device is used to prevent secondary impact on the plastic sheet during the test.

[0014] Furthermore, the anti-secondary impact device includes an arc-shaped slideway, a sliding handle, and a moving element;

[0015] Among them, the arc-shaped slideway is arranged at the lower right part of the anti-secondary impact device, occupying a quarter of the arc of the entire ring. A moving element is arranged in the slideway, and the moving element is fixedly connected to the sliding handle.

[0016] Furthermore, a wedge-shaped element is arranged at the lower part of the slideway, and the part of the wedge-shaped element close to the slideway is a wedge-shaped inclined surface.

[0017] Furthermore, a semi-circular protrusion is arranged on the surface of the wedge-shaped element close to the central axis; a semi-circular groove is arranged at the position corresponding to the wedge-shaped element on the central axis, and the semi-circular groove is meshed and adapted to the semi-circular protrusion.

[0018] Furthermore, slide rails are arranged at the ring notches of the anti-secondary impact device on both sides of the wedge-shaped element.

[0019] Furthermore, the test bench includes a plastic sheet, a support element, and an impact position calibration device;

[0020] Among them, the number of support elements is two, which are arranged at the right end of the test bench and fixedly connected to the upper surface of the test bench; the plastic sheet for the test is placed on the surface of the test bench on the right side of the support element and is attached to the support element; the impact position calibration device is arranged on the upper surface of the test bench and is used to calibrate the impact position.

[0021] Furthermore, it is characterized in that the impact position calibration device includes a first lever, a first fixed column, a second lever, a second fixed column, a first deflectometer, a second deflectometer, and a probe;

[0022] Among them, the first deflectometer, the second deflectometer, the first fixed column, and the second fixed column are arranged on the upper surface of the test bench and fixedly connected to the test bench; the middle parts of the first lever and the second lever are respectively connected to the first fixed column and the second fixed column, so that the first lever and the second lever can rotate around the first fixed column and the second fixed column.

[0023] Furthermore, probes are respectively arranged at one ends of the first lever and the second lever close to the support element, and the probes are in contact with the plastic sheet for the test. The positions of the probes of the first lever and the second lever are at the same distance from the middle position between the two support elements; one ends of the deflection acquisition rods of the first deflectometer and the second deflectometer are provided with probes, and the probes are in contact with one ends of the first lever and the second lever close to the deflectometer.

[0024] The beneficial effects of the present invention are:

[0025] (1) The present invention provides a secondary impact prevention device. When a relatively low energy impact test is conducted, the impact pendulum rebounds after impacting the plastic sheet, and the moving element collides with the wedge-shaped inclined surface of the wedge-shaped element. The semicircular protrusion on the upper surface of the wedge-shaped element engages with the semicircular groove, causing the impact pendulum to stop rotating relative to the central axis. When the next test is conducted, the wedge-shaped element automatically separates from the central axis and returns to its original position under the action of centrifugal force. The device has a simple structure and does not require manual control. It can completely achieve the stopping of the impact pendulum after rebounding and the automatic return of the wedge-shaped element by inertia and centrifugal force, thereby avoiding test errors caused by secondary impact on the plastic sheet.

[0026] (2) By setting up an impact position calibration device, when the impact position calibration of the plastic plate limit performance test device is carried out, when the displacements measured by the first deflectometer and the second deflectometer are different, the position of the impact blade should be adjusted toward the direction of the interferometer with the smaller displacement until the displacements measured by the first deflectometer and the second deflectometer are the same, thereby achieving calibration of the impact position. The impact position calibration device uses the deflectometer to measure the displacement, has the characteristics of high data acquisition accuracy, simple operation, and fast position calibration speed, and avoids the occurrence of test errors caused by inaccurate impact blade position in traditional plastic plate limit performance test devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the overall diagram of the plastic sheet extreme performance testing device;

[0028] Figure 2 A three-dimensional diagram of the device to prevent secondary impact;

[0029] Figure 3 This is a cross-sectional view of the device to prevent secondary impact;

[0030] Figure 4 for Figure 3 A partial enlarged view of the middle A;

[0031] Figure 5 is a cross-sectional view of the moving element;

[0032] Figure 6 A top view of the test bench.

[0033] 1 - Base, 2 - Frame, 3 - Controller, 4 - Central axis, 5 - Anti - secondary - impact device, 6 - Impact pendulum, 7 - Test bench, 8 - Impact blade, 9 - Release handle, 10 - Support element, 11 - Impact - position calibration device, 51 - Arc - shaped slideway, 52 - Sliding handle, 53 - Moving element, 54 - Wedge element, 55 - Semi - circular protrusion, 56 - Semi - circular groove, 57 - Slide rail, 70 - Plastic sheet, 71 - Support element, 72 - First lever, 73 - First fixed column, 74 - Second lever, 75 - Second fixed column, 76 - First deflectometer, 77 - Second deflectometer, 78 - Third deflectometer, 79 - Probe. Specific implementation manner

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] Generally, the ultimate performance test of plastic sheets is completed using an impact testing machine. The test often uses the method of gradually increasing the impact energy to impact the plastic sheets. When the initial impact energy of the test is small, there is a situation of secondary impact on the plastic sheets used in the test by traditional impact testing machines, and the secondary impact affects the accuracy of the test data. On the other hand, due to problems such as the processing accuracy and service life of some impact test devices, there are also deviations in the impact position of the impact blade, resulting in test data errors.

[0036] To solve the above problems, the anti - secondary - impact device and impact - position calibration device of the present invention avoid the secondary impact on plastic sheets and achieve the calibration of the impact position of the impact blade.

[0037] As Figures 1-5 shown, this embodiment provides a device for testing the ultimate performance of plastic sheets, including a base 1, a frame 2, a central axis 4, an anti - secondary - impact device 5, an impact pendulum 6, and a test bench 7. Among them, the frame 2 is arranged on the upper surface of the base 1 and is fixedly connected to the base 1. The upper part of the frame 2 is provided with a controller 3 and a central axis 4. The central axis 4 is fixedly connected to the frame 2. The central axis 4 is perpendicular to the frame 2 and parallel to the upper surface of the base 1. The impact pendulum 6 is connected to the central axis 4 through a bearing. The anti - secondary - impact device 5 is arranged at the circumference of the impact pendulum 6 around the central axis 4, and the anti - secondary - impact device 5 is fixedly connected to the impact pendulum. The test bench 7 is arranged on the upper surface of the base 1 and is fixedly connected to the base 1.

[0038] An impact blade 8 is provided at the lower end of the impact pendulum 6, and the impact blade 8 is fixedly connected to the impact pendulum; a release handle 9 is provided between the impact pendulum 6 and the frame 2.

[0039] It can be understood that the impact pendulum 6 is connected to the central shaft 4 through a bearing. The anti-secondary impact device 5 is arranged at the circumference of the impact pendulum 6 around the central shaft 4, and the anti-secondary impact device 5 is fixedly connected to the impact pendulum. When an impact test is carried out, the impact pendulum 6 drives the anti-secondary impact device 5 and the impact blade 8 to rotate together to realize the impact test on the plastic sheet; by setting the controller 3 and the release handle 9, the release angle of the impact pendulum 6 can be displayed and controlled, and thus the impact energy of the impact blade 8 can be controlled.

[0040] Refer to Figures 2-4 In this embodiment, the anti-secondary impact device 5 includes an arc-shaped slideway 51, a sliding handle 52, a moving element 53, a wedge element 54, a semi-circular protrusion 55, a semi-circular groove 56 and a slide rail 57; among them, the arc-shaped slideway 51 is arranged at the lower right part of the anti-secondary impact device 5, occupying a quarter of the arc of the whole ring. The moving element 53 is arranged in the slideway 51, and the moving element 53 is fixedly connected to the sliding handle 52; a wedge element 54 is arranged at the lower part of the slideway 51. The part of the wedge element 54 close to the slideway 51 is a wedge-shaped inclined surface, and a semi-circular protrusion 55 is arranged on the surface of the wedge element 54 close to the central shaft 4; a semi-circular groove 56 is arranged at the position of the central shaft 4 corresponding to the wedge element 54, and the semi-circular groove 56 is meshed and adapted to the semi-circular protrusion 55; slide rails 57 are arranged at the ring notches of the anti-secondary impact device 5 on both sides of the wedge element 54.

[0041] Through the above settings, when an impact test on a plastic sheet is carried out, the impact pendulum 6 is swung to a certain angle in the upper right direction. At this time, sliding the sliding handle 52 drives the moving element 53 to the upper end of the slideway 51, and turning the release handle 9. Due to the action of gravity, the impact pendulum 6 drives the anti-secondary impact device 5 to swing downward. During the downward movement, the moving element 53 located at the upper end of the slideway 51 swings downward with the impact pendulum 6. When the impact pendulum 6 swings to the lowest point, the impact blade 8 realizes the impact on the plastic sheet. If the impact energy is weak and the impact blade 8 fails to cause a destructive impact on the plastic sheet, the impact pendulum 6 rebounds in the upper right direction. At this time, due to the action of inertia, the moving element 53 continues to move downward along the slideway 51 until it collides with the wedge-shaped inclined surface of the wedge element 54. Under the action of the inertia force of the moving element 53, the wedge element 54 moves upward along the slide rail 57 until the semi-circular protrusion 55 on its upper surface meshes with the semi-circular groove 56. At this time, the relative rotation between the impact pendulum 6 and the central shaft 4 stops.

[0042] When conducting the next test, the impact pendulum 6 is again swung upwards to the right by a certain angle and then released to swing downwards. At this time, the moving element 53 moves upwards relative to the slideway 51 under the action of inertia and separates from the inclined surface of the wedge element 54. The wedge element 54 automatically separates from the central shaft 4 under the action of centrifugal force and returns to its original position; when the moving element 53 gets stuck on the inclined surface of the wedge element 54, the sliding handle 52 is toggled at this time to drive the moving element 53 to separate from the wedge element 54.

[0043] Thus, when conducting an impact test with a smaller energy, after the impact pendulum impacts the plastic sheet and rebounds, the moving element 53 collides with the wedge-shaped inclined surface of the wedge element 54. The semi-circular protrusion 55 on the upper surface of the wedge element 54 engages with the semi-circular groove 56, causing the impact pendulum 6 and the central shaft 4 to stop rotating relative to each other; when conducting the next test, the wedge element 54 automatically separates from the central shaft 4 under the action of centrifugal force and returns to its original position; the structure of this device is simple and does not require manual control. It can completely achieve the stop of the impact pendulum 6 after rebounding and the automatic return of the wedge element 54 through inertia and centrifugal force, avoiding test errors caused by secondary impact on the plastic sheet.

[0044] Refer to Figure 5 In this embodiment, the test bench 7 further includes a plastic sheet 70, a support element 71, and an impact position calibration device 11; the number of support elements 71 is two, which are arranged at the right end of the test bench 7 and fixedly connected to the upper surface of the test bench 7; the plastic sheet 70 for the test is placed on the surface of the test bench 7 on the right side of the support element 71 and is in contact with the support element 71; the impact position calibration device 11 is arranged on the upper surface of the test bench 7.

[0045] The impact position calibration device 11 includes a first lever 72, a first fixed column 73, a second lever 74, a second fixed column 75, a first deflectometer 76, a second deflectometer 77, a third deflectometer 78, and a probe 79. The first deflectometer 76, the second deflectometer 77, and the third deflectometer 78 are arranged on the upper surface of the test bench 7 and fixedly connected to the test bench 7. The first fixed column 73 and the second fixed column 75 are arranged on the upper surface of the test bench 7 and fixedly connected to the test bench 7. The middle parts of the first lever 72 and the second lever 74 are respectively connected to the first fixed column 73 and the second fixed column 75, so that the first lever 72 and the second lever 74 can rotate around the first fixed column 73 and the second fixed column 75. A probe 79 is arranged at one end of the deflection acquisition rod of the third deflectometer 78 close to the support element 71. The position of the probe 79 is in the middle of the two support elements 71 and contacts the plastic sheet 70 for testing. Probes 79 are respectively arranged at one ends of the first lever 72 and the second lever 74 close to the support element 71, and the probes 79 contact the plastic sheet 70 for testing. The positions of the probes of the first lever 72 and the second lever 74 are at the same distance from the middle position of the two support elements 71. Probes 79 are arranged at one ends of the deflection acquisition rods of the first deflectometer 76 and the second deflectometer 77, and the probes contact one ends of the first lever 72 and the second lever 74 close to the deflectometer.

[0046] With the above settings, when calibrating the impact position of the plastic sheet ultimate performance testing device, a small-energy impact on the plastic sheet 70 is taken. This impact will not damage the plastic sheet 70, but the impact force of the impact blade 8 causes a certain deflection of the plastic sheet 70. At this time, the plastic sheet 70 presses the probes of the first lever 72 and the second lever 74 to move. The probes respectively drive the first lever 72 and the second lever 74 to rotate around the first fixed column 73 and the second fixed column 75. The first deflectometer 76 and the second deflectometer 77 can respectively measure the displacement amounts of one ends of the first lever 72 and the second lever 74 close to the deflectometer. If the displacement amounts measured by the first deflectometer 76 and the second deflectometer are the same, the position of the impact blade 8 is in the middle of the two support elements 71, and no calibration is required at this time. When the displacement amounts measured by the first deflectometer 76 and the second deflectometer 77 are different, the position of the impact blade 8 should be adjusted in the direction of the deflectometer with the smaller displacement amount until the displacement amounts measured by the first deflectometer 76 and the second deflectometer 77 are the same. The probe of the third deflectometer 78 is in the middle position of the two support elements 71 and is used to measure the maximum deflection of the plastic sheet 70.

[0047] The working principle of the present invention is as follows: The plastic sheet test is carried out by gradually increasing the impact energy. By setting the anti-secondary impact device 5, during the test, when the set impact energy is small, the impact blade 8 fails to cause a destructive impact on the plastic sheet, and the impact pendulum 6 rebounds upward to the right. At this time, due to the effect of inertia, the moving element 53 continues to move downward along the slideway 51 until it collides with the wedge surface of the wedge element 54. Under the action of the inertial force of the moving element 53, the wedge element 54 moves upward along the slide rail 57 until the semi-circular protrusion 55 on its upper surface engages with the semi-circular groove 56. At this time, the relative rotation between the impact pendulum 6 and the central shaft 4 stops; when conducting the next test, the sliding handle 52 is slid to the upper end of the slideway 51 again. At this time, the wedge element 54 automatically separates from the central shaft 4 under the action of gravity. The structure of this device is simple and does not require manual control. It can completely achieve the stop of the impact pendulum 6 after rebound and the automatic return of the wedge element 54 through inertia and centrifugal force, avoiding test errors caused by secondary impact on the plastic sheet.

[0048] By setting the impact position calibration device 11, when calibrating the impact position of the plastic sheet ultimate performance test device, a small-energy impact on the plastic sheet 70 is taken. This impact will not cause damage to the plastic sheet 70, but the impact force of the impact blade 8 causes a certain deflection of the plastic sheet 70. At this time, the plastic sheet 70 presses the probes of the first lever 72 and the second lever 74 to move. The probes drive the first lever 72 and the second lever 74 to rotate around the first fixed column 73 and the second fixed column 75 respectively. The first deflectometer 76 and the second deflectometer 77 can respectively measure the displacement of the ends of the first lever 72 and the second lever 74 close to the deflectometer; if the displacements measured by the first deflectometer 76 and the second deflectometer are the same, the position of the impact blade 8 is in the middle of the two support elements 71, and calibration is not required at this time; when the displacements measured by the first deflectometer 76 and the second deflectometer 77 are different, the position of the impact blade 8 should be adjusted in the direction of the deflectometer with a smaller displacement until the displacements measured by the first deflectometer 76 and the second deflectometer 77 are the same, so as to achieve the calibration of the impact position. The impact position calibration device 11 uses a deflectometer to measure the displacement, which has the characteristics of high data acquisition accuracy, simple operation, and fast position calibration speed, avoiding the occurrence of test errors caused by inaccurate impact blade position in the traditional plastic sheet ultimate performance test device.

Claims

1. A testing device for the ultimate performance of plastic sheets, comprising: A base; A frame, disposed on the upper surface of the base and fixedly connected to the base; A central axis, disposed at the upper part of the frame, with its axis perpendicular to the frame and parallel to the upper surface of the base; An impact pendulum, connected to the central axis through a bearing; An anti-secondary impact device, disposed at the circumference of the impact pendulum around the central axis, and fixedly connected to the impact pendulum; A test bench, disposed on the upper surface of the base and fixedly connected to the base; Characterized in that an impact edge is provided at the lower end of the impact pendulum, and the impact edge is fixedly connected to the impact pendulum; a release handle is provided between the impact pendulum and the frame, and the anti-secondary impact device is used to prevent secondary impact on the plastic sheet during the test; The anti-secondary impact device includes an arc-shaped slideway, a sliding handle, and a moving element; Wherein, the arc-shaped slideway is disposed at the lower right part of the anti-secondary impact device, occupying a quarter of the arc of the entire ring. A moving element is disposed in the slideway, and the moving element is fixedly connected to the sliding handle; a wedge element is disposed at the lower part of the slideway. The part of the wedge element close to the slideway is a wedge-shaped inclined surface; a semi-circular protrusion is provided on the surface of the wedge element close to the central axis; a semi-circular groove is provided at the position of the central axis corresponding to the wedge element, and the semi-circular groove is meshed and adapted to the semi-circular protrusion; slide rails are provided at the ring notches of the anti-secondary impact device on both sides of the wedge element.

2. The plastic sheet ultimate performance testing device according to claim 1, characterized in that, The test bench includes a plastic sheet, a supporting element, and an impact position calibration device; Wherein, the number of the supporting elements is two, disposed at the right end of the test bench and fixedly connected to the upper surface of the test bench; the plastic sheet for the test is placed on the surface of the test bench on the right side of the supporting element and is in contact with the supporting element; the impact position calibration device is disposed on the upper surface of the test bench for calibrating the impact position.

3. The plastic sheet ultimate performance testing device according to claim 2, characterized in that The impact position calibration device includes a first lever, a first fixed column, a second lever, a second fixed column, a first deflection gauge, a second deflection gauge, and a probe; Wherein, the first deflection gauge, the second deflection gauge, the first fixed column, and the second fixed column are disposed on the upper surface of the test bench and fixedly connected to the test bench; the middle parts of the first lever and the second lever are respectively connected to the first fixed column and the second fixed column, so that the first lever and the second lever can rotate around the first fixed column and the second fixed column.

4. The plastic sheet ultimate performance testing device according to claim 3, characterized in that Probes are respectively provided at one ends of the first lever and the second lever close to the supporting element, and the probes are in contact with the plastic sheet for the test. The positions of the probes of the first lever and the second lever are at the same distance from the middle position between the two supporting elements; probes are provided at one ends of the deflection acquisition rods of the first deflection gauge and the second deflection gauge, and the probes are in contact with one ends of the first lever and the second lever close to the deflection gauges.

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