PET preform wall thickness measuring device

Abstract

The utility model relates to the technical field of measurement, concretely relates to PET bottle blank wall thickness measuring device. Including base, the slide of the base is provided with slide plate, the drive unit that can drive the slide of base is provided with on the base, the upper end of slide plate is provided with measuring assembly, the slide plate below measuring assembly is provided with the bottle blank clamping rotation subassembly. Through motor drive first screw rod drive slide plate right shift, make the circular platform push support unit radial expansion clamping bottle blank, when the roof is close to bottle blank inner wall, slide plate continues right shift compression elastic telescopic link, trigger second screw rod and circular platform relative movement, drive bottle blank automatic rotation. This design realizes electronic dial gauge to bottle blank 360 degree wall thickness's continuous scanning measurement, avoids the blind area of manual point measurement completely, and the data integrity and detection efficiency are improved obviously.

Description

Technical Field

[0001] This utility model relates to the field of measurement technology, specifically to a device for measuring the wall thickness of PET preforms. Background Technology

[0002] In the production and quality control of PET preforms, wall thickness uniformity is a key indicator determining product performance, directly affecting the preform's mechanical strength, sealing properties, and service life. As a core component of beverage and food packaging, wall thickness deviations in PET preforms can lead to leakage during filling, damage during transportation, or shortened shelf life. Therefore, accurate wall thickness measurement is essential to ensure product quality and safety. However, traditional measurement methods have significant shortcomings: manual operation relies on point measurements using calipers or simple measuring tools, which is inefficient and susceptible to human error, resulting in poor data repeatability. While existing automated equipment can improve efficiency to some extent, it is often complex in structure, expensive, and struggles to achieve stable preform clamping and continuous 360-degree rotation measurement. Furthermore, preform displacement or deformation during measurement can affect accuracy. In addition, existing technologies lack effective calibration mechanisms, making it impossible to standardize instrument calibration before measurement, further reducing data reliability and comparability, and hindering rapid quality inspection in large-scale production environments.

[0003] To address these shortcomings, the industry urgently needs an efficient, accurate, and easy-to-operate automated measuring device that can automatically clamp preforms, perform multi-angle rotation measurement, and provide real-time calibration to improve measurement efficiency and accuracy.

[0004] In the prior art, patent document CN221802725U discloses a device for detecting the wall thickness of a bottle preform. This technical solution utilizes the coordinated operation of a drive motor, a rotating rod, a driving bevel gear, a driven bevel gear, a threaded rod, a movable block, and an outer support block to fix the bottle preform, and then uses a dial indicator to detect the preform thickness, eliminating the need for manual fixation. Alternatively, the coordinated operation of a brake motor, a driving gear, a driven gear, a mounting bracket, and a positioning rod can rotate the preform, eliminating the need for manual rotation and enabling thickness detection around the entire circumference of the preform. However, this technical solution requires two motors for stabilizing and rotating the preform, resulting in high device costs.

[0005] Patent document CN219798286U discloses a plastic bottle preform wall thickness gauge. The gauge features a threaded rod for easy vertical movement of a mounting frame, a limiting block to prevent excessive upward movement and potential detachment, a mounting frame for easy installation of a telescopic rod, a telescopic rod for easy inward clamping of a clamping block, and a drive motor for easy rotation of the threaded rod, thus moving the mounting frame vertically. A rotating disk allows for wall thickness measurement at various angles of the preform. A ball bearing facilitates free rotation of the disk. A first mounting base facilitates the installation of a detection rod. A dart head facilitates sensing the preform wall thickness. The mounting rod facilitates the installation of a test gauge, which in turn senses and measures the wall thickness with the dart head. However, when using the test gauge and dart head to detect the wall thickness at multiple points along the circumferential direction of the preform, manual rotation of the rotating disk is required, making it impossible to automatically and continuously measure the wall thickness along the circumferential direction. Utility Model Content

[0006] The main purpose of this invention is to provide a device that can conveniently fix and install PET preforms, facilitate the rotation of PET preforms during measurement, and continuously measure the circumferential wall thickness of PET preforms.

[0007] To achieve the above objectives, the technical solution provided by this utility model is as follows: A PET preform wall thickness measuring device includes a base, a slide plate slidably mounted on the base, a drive unit on the base capable of driving the slide plate to slide, a measuring component on the upper end of the slide plate, and a preform clamping and rotating component on the slide plate below the measuring component. The preform clamping and rotating component includes a fixed ring fixedly connected to the base, and multiple support units evenly distributed around one end of the fixed ring. Each support unit includes a positioning element rotatably connected to the fixed ring, and a support element elastically slidably mounted on the positioning element. The sliding direction of the support element is parallel to the radial direction of the positioning ring. A frustum is arranged between the multiple support units, and a groove corresponding to the support unit is opened on the outer side of the frustum. The length direction of the groove is parallel to the generatrix of the frustum. One end of the support element is slidably mounted in the groove. A second lead screw is fixed on the slide plate, passing through the frustum and concentrically threaded to the frustum. A rotating ring is rotatably mounted on one end of the frustum, and the rotating ring is connected to the slide plate through multiple elastic telescopic rods. The diameter of the frustum is larger at the end closer to the slide plate and smaller at the end farther from the slide plate.

[0008] Specifically, the upper end of the base is provided with a guide groove, the lower end of the slide plate is slidably disposed in the guide groove, the drive unit includes a first lead screw, the first lead screw is rotatably disposed in the guide groove, the first lead screw passes through the lower end of the slide plate, the first lead screw is threadedly connected to the slide plate, a motor is fixed on the base, and the output shaft of the motor is concentrically fixedly connected to the first lead screw.

[0009] Specifically, the slide plate is inverted L-shaped, with the lower end of the vertical sliding section slidably disposed in the guide groove, and the measuring component mounted on the flat section of the slide plate.

[0010] Specifically, the measuring component includes a telescopic rod fixed to the straight part of the slide plate. The telescopic rod is vertically arranged, and an electronic dial indicator is fixed to the telescopic end of the telescopic rod.

[0011] Specifically, the telescopic rod is an electric push rod, and the telescopic rod, electronic dial indicator, controller and display screen are electrically connected.

[0012] Specifically, the positioning component includes a locking plate that is rotatably engaged in an annular groove on a fixed ring. A support rod is fixed on the locking plate, with its length direction parallel to the axial direction of the fixed ring. The support rod has a reduced diameter section. The support component includes a sliding rod with an elongated groove. The length direction of the groove is parallel to the length direction of the sliding rod, and the length direction of the sliding rod is parallel to the radial direction of the fixed ring. The reduced diameter section of the support rod is elastically engaged in the elongated groove. The end of the sliding rod closest to the axis of the fixed ring is slidably disposed in the groove, and the end of the sliding rod furthest from the axis of the fixed ring is fixed with a top plate.

[0013] Specifically, a spring is installed in the long groove, with one end of the spring fixedly connected to the slide rod and the other end of the spring fixedly connected to the reduced diameter part of the support rod.

[0014] Specifically, the top plate is arc-shaped, concentric with the fixing ring, and a rubber pad is fixed to the outer edge of the top plate.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. The motor drives the first lead screw to move the slide plate to the right, causing the truncated cone to push the support unit to expand radially and clamp the preform. After the top plate presses against the inner wall of the preform, the slide plate continues to move to the right, compressing the elastic telescopic rod, triggering the second lead screw to move relative to the truncated cone, causing the preform to rotate automatically. This design enables continuous scanning measurement of the preform's wall thickness at 360° using an electronic dial indicator, completely avoiding blind spots in manual measurement and significantly improving data integrity and inspection efficiency.

[0016] 2. A pre-set groove is positioned in the standard preform. After clamping, the preform is rotated until the groove aligns with the electronic dial indicator. The dial indicator contacts pass through the groove and reach the bottom reference surface, completing the zeroing operation and eliminating system errors. This mechanism ensures a consistent measurement benchmark and significantly improves the comparability of data from different batches of products.

[0017] 3. The slide bar is elastically connected to the reduced-diameter section of the support rod via a spring, providing radial buffering; the frustum-shaped conical surface mates with the end of the slide bar, and when moving left, the slide groove pushes the slide bar to automatically retract radially, while when moving right, it expands and clamps. This achieves full automation of the clamping, measuring, and releasing process, avoiding positioning deviations caused by manual intervention.

[0018] 4. The elastic telescopic rod connects the rotating ring and the sliding plate. When the clamping force exceeds the limit, it compresses and absorbs energy to prevent the preform from being crushed. When the motor reverses after the measurement, the sliding plate moves to the left, driving the frustum to slide to the left. The conical surface forces the sliding rod to retract inward and reset synchronously. The top plate disengages from the inner wall of the preform, ensuring zero-residue clamping and facilitating quick sample replacement. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the present invention.

[0020] Figure 2 This is a schematic diagram showing the rotating connection between the ring and the frustum.

[0021] Figure 3 This is a schematic diagram showing the connection between the support component and the positioning component.

[0022] Figure 4 This is a schematic diagram showing the connection between the slide rod and the slide groove.

[0023] Figure 5 for Figure 4 A magnified view of region A in the middle.

[0024] Figure 6 This is a schematic diagram of the positioning component.

[0025] The components in the attached diagram are named as follows: 1. Base; 2. Guide groove; 3. Motor; 4. Slide plate; 5. Second lead screw; 6. Elastic telescopic rod; 7. Frustum; 8. Rotary ring; 9. Slide groove; 10. Slide rod; 11. Long groove; 12. Support rod; 13. Reduced diameter section; 14. Spring; 15. Clamping plate; 16. Fixing ring; 17. Ring groove; 18. Top plate; 19. Rubber pad; 20. Telescopic rod; 21. Electronic dial indicator. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0027] Example 1: Refer to Figures 1-6 As shown, the PET preform wall thickness measuring device includes a base 1, a slide plate 4 slidably mounted on the base 1, a drive unit capable of driving the slide plate 4 to slide on the base 1, and a measuring component mounted on the upper end of the slide plate 4.

[0028] The upper end of the base 1 is provided with a guide groove 2, and the lower end of the slide plate 4 is slidably disposed in the guide groove 2. The drive unit includes a first lead screw, which is rotatably disposed in the guide groove 2. The first lead screw passes through the lower end of the slide plate 4 and is threadedly connected to the slide plate 4. A motor 3 is fixed on the base 1, and the output shaft of the motor 3 is concentrically fixedly connected to the first lead screw.

[0029] The slide plate 4 is inverted L-shaped, and the lower end of the vertical part is slidably set in the guide groove 2. The measuring component is installed on the flat part of the slide plate 4.

[0030] The measuring component includes a telescopic rod 20 fixed on the straight part of the slide plate 4. The telescopic rod 20 is vertically arranged, and an electronic dial indicator 21 is fixed on the telescopic end of the telescopic rod 20.

[0031] Telescopic rod 20 is an electric push rod, and telescopic rod 20, electronic dial indicator 21, controller and display screen are electrically connected.

[0032] A preform clamping and rotating assembly is installed on the slide plate 4 below the measuring component.

[0033] The preform clamping and rotating assembly includes a fixing ring 16 fixedly connected to the base 1, and multiple support units are evenly distributed around one end of the fixing ring 16.

[0034] The support unit includes a positioning member rotatably connected to the fixed ring 16. A support member is elastically slidably disposed on the positioning member, and the sliding direction of the support member is parallel to the radial direction of the positioning ring.

[0035] A frustum 7 is provided between multiple support units. A groove 9 corresponding to the support unit is provided on the outer side of the frustum 7. The length direction of the groove 9 is parallel to the generatrix of the frustum 7. One end of the support member is slidably disposed in the groove 9.

[0036] A second lead screw 5 is fixed on the slide plate 4. The second lead screw 5 passes through the frustum 7 and is concentrically threaded to the frustum 7. The diameter of the frustum 7 is larger at the end closer to the slide plate 4 and smaller at the end farther away from the slide plate 4.

[0037] A rotating ring 8 is rotatably mounted on one end of the frustum 7. The rotating ring 8 is connected to the slide plate 4 via multiple elastic telescopic rods 6. One end of the elastic telescopic rod 6 is fixedly connected to the rotating ring 8, and the other end of the elastic telescopic rod 6 is fixedly connected to the slide plate 4.

[0038] The positioning component includes a clamping plate 15, which is rotatably engaged in the annular groove 17 on the fixing ring 16. A support rod 12 is fixed on the clamping plate 15. The length direction of the support rod 12 is parallel to the axial direction of the fixing ring 16. A reduced diameter portion 13 is provided on the support rod 12.

[0039] The support includes a slide rod 10 with an elongated groove 11. The length of the groove 11 is parallel to the length of the slide rod 10, and the length of the slide rod 10 is parallel to the radial direction of the fixing ring 16. The reduced diameter portion 13 of the support rod 12 is elastically slidably engaged within the elongated groove 11. A spring 14 is installed within the elongated groove 11, with one end of the spring 14 fixedly connected to the slide rod 10 and the other end of the spring 14 fixedly connected to the reduced diameter portion 13 of the support rod 12. The end of the slide rod 10 closest to the axis of the fixing ring 16 is slidably disposed within a sliding groove 9, while the end of the slide rod 10 furthest from the axis of the fixing ring 16 is fixed with a top plate 18.

[0040] After the outer edge of the top plate 18 is pressed against the inner edge of the PET preform, the outer edge of the top plate 18 is in contact with the inner edge of the PET preform.

[0041] When using this device, the PET preform to be measured is placed over multiple support components, and then motor 3 is started. Motor 3 drives the first lead screw to rotate in the forward direction, as shown below. Figure 1 As shown, after motor 3 drives the first lead screw to rotate in the forward direction, the slide plate 4, measuring component, elastic telescopic rod 6, second lead screw 5, rotating ring 8, and frustum 7 move to the right. Under the guidance of slide groove 9 on slide rod 10, multiple slide rods 10 simultaneously slide outwards from frustum 7. When top plate 18 is pressed against the inner edge of PET preform, top plate 18 can no longer move outwards from frustum 7. At the same time, frustum 7 can no longer move to the right. Motor 3 is turned off, and telescopic rod 20 is started. Telescopic rod 20 drives electronic dial indicator 21 to descend to the lower stop point. At this time, the contact of electronic dial indicator 21 contacts the outer edge of PET preform. The wall thickness of PET preform is observed according to the value of electronic dial indicator 21. The reading of electronic dial indicator 21 is displayed on the display in real time and stored in the storage unit of the controller.

[0042] Then, motor 3 is started again, causing the first lead screw to rotate in the forward direction, and the slide plate 4 continues to move to the right. At this time, since the frustum 7 can no longer move to the right, the elastic telescopic rod 6 is compressed, and the second lead screw 5 moves relative to the frustum 7. The frustum 7, multiple support components and PET preform can rotate. During the rotation of the PET preform, the electronic dial indicator 21 can continuously measure the bottle wall in the circumferential direction of the PET preform.

[0043] In this embodiment, the electronic dial indicator 21 needs to be calibrated before measuring the wall thickness of the PET preform. During calibration, a PET preform with a standard wall thickness is taken, and a groove is made in the preform's wall. Then, the motor 3 is started, and multiple top plates 18 are used to clamp the standard PET preform, with one top plate 18 aligning with the groove on the standard PET preform. The motor 3 is started again, causing the first lead screw to rotate forward, which in turn causes the multiple support components and the standard PET preform to rotate. When the groove on the standard PET preform is directly below the electronic dial indicator 21, the telescopic rod 20 is activated, causing it to move the electronic dial indicator 21 down to its lower limit. At this point, the contact of the electronic dial indicator 21 passes through the groove on the standard PET preform and contacts the outer edge of the top plate 18. The electronic dial indicator 21 is then zeroed, and subsequent wall thickness measurements can be performed on other PET preforms.

[0044] After the wall thickness of the PET preform is measured, the telescopic rod 20 drives the electronic dial indicator 21 to move upward and reset, which causes the motor 3 to drive the first lead screw to rotate in the opposite direction, and the slide plate 4 moves to the left.

[0045] As the slide plate 4 moves to the left, the second lead screw 5 moves synchronously to the left. The second lead screw 5 passes through and is threadedly connected to the frustum 7, but at this stage, the frustum 7 does not move immediately (because the preform clamping rotating assembly still has residual resistance). The rotating ring 8 is connected to the slide plate 4 through multiple elastic telescopic rods 6. In the initial stage of the leftward movement of the slide plate 4, the elastic telescopic rods 6, due to their pre-compression state, begin to release their elastic force, and the frustum 7 drives the support unit to rotate. The fixed ring 16 is fixedly connected to the base 1 and does not move with the slide plate 4. The support is initially in an expanded state (the top plate 18 is tightly attached to the inner wall of the preform), but as the slide plate 4 moves to the left, the frustum 7 begins to respond with movement. The leftward movement of the second lead screw 5 drives the frustum 7 to move to the left through the threaded connection. The leftward movement of the frustum 7 causes the slide groove 9 to guide the slide rod 10 of the support.

[0046] The length of the slide groove 9 is parallel to the generatrix of the frustum 7. When the frustum 7 moves to the left, the slide groove 9 pushes the slide rod 10 to slide towards the axis along the radial direction of the fixed ring 16 (i.e., to retract inward). The slide rod 10 moves inward and causes the top plate 18 to detach from the inner wall of the preform and return to its original position towards the axis of the fixed ring 16.

[0047] When the frustum 7 moves to the left, the rotating ring 8 moves accordingly, but the fixed ring 16 remains stationary. After the top plate 18 is completely detached from the preform, the spring 14 releases energy, and the auxiliary slide rod 10 quickly returns to its initial retracted position. At the same time, the elastic telescopic rod 6 fully extends, stabilizing the entire clamping assembly in the relaxed position.

[0048] When the slide plate 4 moves to the left to the initial position, the multiple top plates 18 reset, and then the measured PET preform can be removed.

[0049] Example 2: Based on Example 1, referring to... Figure 3 As shown, the top plate 18 is arc-shaped and concentric with the fixing ring 16. A rubber pad 19 is fixed to the outer edge of the top plate 18.

[0050] In this embodiment, by providing a rubber pad 19 on the top plate 18, the friction between the top plate 18 and the inner wall of the PET preform can be increased, thereby improving the stability of the PET preform to be measured during the measurement process.

[0051] In this embodiment, when calibrating the dial indicator, the contacts of the electronic dial indicator 21 need to contact the outer edge of the rubber pad 19 before the zeroing operation is performed.

[0052] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A PET preform wall thickness measuring device, comprising a base (1), a sliding plate (4) slidably disposed on the base (1), and a driving unit capable of driving the sliding plate (4) to slide on the base (1), characterized in that, A measuring component is provided at the upper end of the slide plate (4), and a bottle preform clamping and rotating component is provided on the slide plate (4) below the measuring component. The bottle preform clamping and rotating component includes a fixing ring (16) fixedly connected to the base (1). Multiple support units are evenly distributed around one end of the fixing ring (16). Each support unit includes a positioning component rotatably connected to the fixing ring (16). A support component is elastically slidably provided on the positioning component. The sliding direction of the support component is parallel to the radial direction of the positioning ring. A frustum (7) is provided between the multiple support units. An opening is provided on the outer side of the frustum (7) for connecting with the support. The slide groove (9) corresponding to the support unit is parallel to the generatrix of the frustum (7) in the length direction. One end of the support member is slidably set in the slide groove (9). A second lead screw (5) is fixed on the slide plate (4). The second lead screw (5) passes through the frustum (7). The second lead screw (5) is concentrically threaded with the frustum (7). A rotating ring (8) is rotatably set at one end of the frustum (7). The rotating ring (8) is connected to the slide plate (4) through multiple elastic telescopic rods (6). The diameter of the frustum (7) is larger at the end closer to the slide plate (4) and smaller at the end farther away from the slide plate (4).

2. The PET preform wall thickness measuring device according to claim 1, characterized in that, The base (1) has a guide groove (2) at its upper end, and the slide plate (4) is slidably disposed in the guide groove (2) at its lower end. The drive unit includes a first lead screw, which is rotatably disposed in the guide groove (2). The first lead screw passes through the lower end of the slide plate (4) and is threadedly connected to the slide plate (4). A motor (3) is fixed on the base (1), and the output shaft of the motor (3) is concentrically fixedly connected to the first lead screw.

3. The PET preform wall thickness measuring device according to claim 2, characterized in that, The slide plate (4) is inverted L-shaped, and the lower end of the vertical part of the slide plate is slidably disposed in the guide groove (2). The measuring component is installed on the flat part of the slide plate (4).

4. The PET preform wall thickness measuring device according to claim 3, characterized in that, The measuring component includes a telescopic rod (20) fixed on the straight part of the slide plate (4), the telescopic rod (20) is vertically arranged, and an electronic dial indicator (21) is fixed on the telescopic end of the telescopic rod (20).

5. The PET preform wall thickness measuring device according to claim 4, characterized in that, The telescopic rod (20) is an electric push rod, and the telescopic rod (20), electronic dial indicator (21), controller and display screen are electrically connected.

6. The PET preform wall thickness measuring device according to claim 1, characterized in that, The positioning component includes a clamping plate (15), which is rotatably clamped in the annular groove (17) on the fixed ring (16). A support rod (12) is fixed on the clamping plate (15). The length direction of the support rod (12) is parallel to the axial direction of the fixed ring (16). A reduced diameter part (13) is provided on the support rod (12). The support component includes a sliding rod (10), which has a long groove (11). The length direction of the long groove (11) is parallel to the length direction of the sliding rod (10). The length direction of the sliding rod (10) is parallel to the radial direction of the fixed ring (16). The reduced diameter part (13) of the support rod (12) is elastically and slidably clamped in the long groove (11). One end of the sliding rod (10) near the axis of the fixed ring (16) is slidably disposed in the sliding groove (9). One end of the sliding rod (10) away from the axis of the fixed ring (16) is fixed with a top plate (18).

7. The PET preform wall thickness measuring device according to claim 6, characterized in that, A spring (14) is provided in the long groove (11). One end of the spring (14) is fixedly connected to the slide rod (10), and the other end of the spring (14) is fixedly connected to the reduced diameter part (13) of the support rod (12).

8. The PET preform wall thickness measuring device according to claim 6, characterized in that, The top plate (18) is arc-shaped and concentric with the fixing ring (16). A rubber pad (19) is fixed on the outer edge of the top plate (18).

9. The PET preform wall thickness measuring device according to claim 1, characterized in that, One end of the elastic telescopic rod (6) is fixedly connected to the swivel (8), and the other end of the elastic telescopic rod (6) is fixedly connected to the slide plate (4).

Images