PE plastic empty bottle body defect detection device

Abstract

The present application relates to the technical field of bottle blank detection, and particularly relates to a PE plastic empty bottle body defect detection device including a detection shell, a longitudinal partition frame being arranged at the edge of one end of the detection shell close to a transverse support frame, a full-flexible contact type positioning and force applying structure, an induction air bag in a deformation induction assembly abutting against a concave end in a cambered surface and a latch lever frame, a flexible concave ring of a sleeving assembly, and a flexible support arm of an inner neck connecting section forming a coordinated flexible contact system, which can be self-adaptively attached to bottle bodies with different profiles, so as to avoid rigid contact to cause secondary damage such as scratches, extrusion deformation and the like to the bottle body, meanwhile, with the help of a gas injection joint to inject gas into the inflation cavity of the induction air bag, the deformation excitation strength can be adjusted, so that only reversible elastic deformation is generated on the qualified bottle body, and the original shape can be quickly restored after detection, not only the structural integrity and subsequent use performance of the bottle body after detection are effectively ensured, but also the detection scene of light PE plastic empty bottles with thin wall thickness can be adapted.

Description

Technical Field

[0001] This invention relates to the field of preform inspection technology, and in particular to a device for detecting defects in the body of empty PE plastic bottles. Background Technology

[0002] PE plastic empty bottles, with their advantages of being lightweight, corrosion-resistant, and inexpensive, are widely used in various fields such as food and beverage, daily chemicals, and pharmaceuticals. They are one of the most widely used packaging containers in the packaging industry. The integrity and surface quality of the bottle directly affect the product's storage safety, transportation stability, and brand image. For example, defects such as cracks, dents, deformation, and impurities on the bottle can not only lead to packaging seal failure, causing leakage and spoilage of the contents, but may also cause equipment jams in subsequent automated production lines such as filling and sealing, affecting production efficiency and even posing safety hazards. Therefore, comprehensive and accurate defect detection of PE plastic empty bottles before they leave the factory and before they are filled on the production line is an indispensable and crucial step in the packaging quality control process.

[0003] With the development of industrial automation technology, some companies have begun to use mechanical contact-based inspection equipment for defect screening. This type of equipment uses mechanical probes and other components to contact the bottle surface and sense changes in surface unevenness to determine whether defects exist. However, this technology also has significant limitations. On the one hand, mechanical contact inspection can easily cause secondary damage to the PE plastic empty bottles, especially for thin-walled, lightweight bottles, where the pressure of the probe may cause deformation. On the other hand, this technology can only detect physical protrusions or depressions on the bottle surface and cannot identify impurities, black spots, or light transmission defects inside the bottle. The detection range is quite limited, and the detection speed is slow, making it difficult to meet the real-time inspection needs of high-speed production lines.

[0004] A Chinese invention patent, CN116273966 A, discloses a linear PET preform defect detection device. The device includes a conveyor frame with a conveying mechanism and a rejection mechanism. The loading frame is equipped with a loading chute, a loading assembly, a detection assembly, a unloading assembly, and an unloading chute. The loading chute transports the preforms to the loading assembly, which clamps the preforms and transports them to the conveying mechanism. The conveying mechanism moves the preforms forward and passes through the detection assembly for inspection. The rejection mechanism removes preforms that fail the detection assembly. Preforms that pass the detection assembly are clamped by the unloading assembly and transported to the unloading chute. This invention employs a linear conveying method, which is simple in structure and provides strong conveying stability. The chain conveying mechanism, compared to a fixed conveyor belt, ensures stable transmission for preform inspection. Furthermore, it can simultaneously complete the comprehensive inspection of the preform body and mouth on a single conveyor line. The backlight reduces glare caused by the cylindrical shape of the preforms, improving detection accuracy.

[0005] However, the automated testing devices, including those mentioned in the patents, lack the ability to predict and detect the potential deformation risks of empty PE plastic bottles due to the inherent creep characteristics of the material. PE plastic is prone to slow and irreversible creep deformation under continuous external force or changes in ambient temperature. Bottles in the same batch may have different creep sensitivities due to uneven molecular chain arrangement and differences in crystallinity during production. Some bottles may be qualified in appearance when they leave the factory, but may deform or become misaligned due to creep during transportation and storage, which may lead to jamming and sealing failure of the filling line. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and to propose a device for detecting defects in the body of empty PE plastic bottles.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: The device includes a detection housing, with a longitudinal partition frame located at one edge of the detection housing near the transverse support frame. A placement cavity is provided between the transverse support frame and the longitudinal partition frame. An acoustic sensing extension probe is fixedly mounted on the upper surface of the transverse support frame. A fixed base is fixedly mounted on the inner wall of the detection housing near the longitudinal partition frame. A pulsed laser probe is fixedly mounted on the upper surface of the fixed base by bolts. A limiting connecting frame is fixedly mounted on the upper surface of the longitudinal partition frame. Elastic cavity arms are provided on both sides of the limiting connecting frame. A deformation sensing component is movably engaged with the inner wall of the elastic cavity arm. The acoustic sensing extension probe is placed on one side of the deformation sensing component, and the pulsed laser probe is perpendicularly adapted to the deformation sensing component.

[0008] Preferably, the deformation sensing component includes a spring-locking rod frame that is movably snapped to the middle of both sides of the limiting connecting frame. The inner end face of the spring-locking rod frame is provided with an inwardly recessed bent end, and one end of the spring-locking rod frame is provided with a folded bottom end.

[0009] Preferably, an elastic hinge arm is provided between the bottom end of the folded edge and the middle spring lock rod frame, and a sensing airbag is connected through the side end face of the spring lock rod frame away from the bottom end of the folded edge.

[0010] Preferably, the inner arc surface of the sensing airbag is provided with an abutting arc surface, the inner arc surface of the sensing airbag is provided with an expansion air cavity, and the inner arc surface of the abutting arc surface is attached to the surface of the concave bend end.

[0011] Preferably, the top of the inner arc surface of the sensing airbag is provided with a support shaft section, the inner sidewall of the support shaft section is provided with an annular groove, and a sleeve assembly is engaged in the annular groove of the support shaft section.

[0012] Preferably, the sleeve assembly includes a connecting bottle ring that is sleeved into the inner arc surface of the annular groove, and the top end of the connecting bottle ring is provided with a limiting flange, which is movably engaged into the annular groove of the support shaft section.

[0013] Preferably, the connecting bottle ring has a flexible concave ring in the middle and an expansion section at the tail end, and the concave surface of the flexible concave ring is adapted to the concave bend in the middle of the spring lock rod frame.

[0014] Preferably, the inner arc surface of the connecting bottle ring is provided with an inner neck connecting section, the inner arc surface of the inner neck connecting section is provided with a flexible support arm, and the outer arc surface of the connecting bottle ring is provided with a sound-catching hole.

[0015] Preferably, the sound-capturing hole corresponds to the acoustic sensing extension probe on one side, the outer arc surface of the sensing airbag is connected to an air injection connector, one end of the air injection connector is adapted to the expansion air chamber, and several empty plastic bottles are arranged in the placement cavity at the bottom of the detection housing.

[0016] Preferably, an air cover is movably engaged with one side of the support shaft section inside the sensing airbag. The front end of the air cover is provided with a hook end, which is movably engaged with one side of the spring lock rod frame. The inner arc surface of the air cover is provided with a bent sealing section, which fits against the surface of the flexible concave ring. An air cavity is provided between the air cover and the bent sealing section. An air hole is opened on the side of the air cover near the air cavity. The tail end of the air cover is provided with a folded flexible part, which extends into the interior of the flexible concave ring. A hole corresponding to the air hole is opened on one side of the flexible concave ring. The outer arc surface of the air cover is adapted to the sensing airbag.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. Through a fully flexible contact positioning and force application structure, the sensing airbag in the deformation sensing component abuts against the arc surface and the concave bend of the spring lock rod frame, forming a collaborative flexible contact system with the flexible concave ring of the sleeve component and the flexible support arm of the inner neck connecting section. This system can adaptively conform to bottle bodies with different contours, avoiding secondary damage such as scratches, squeezing, and deformation caused by rigid contact. At the same time, by using the air injection connector to control the air injection of the sensing airbag expansion chamber, the deformation excitation intensity can be adjusted to ensure that qualified bottles only produce reversible elastic deformation and can quickly return to their original shape after testing. This not only effectively ensures the structural integrity and subsequent performance of the bottle after testing, but also adapts to the testing scenarios of thin-walled, lightweight PE plastic empty bottles, avoiding bottle scrapping due to improper force application and reducing material waste in the enterprise's testing process.

[0018] 2. By controlling the expansion of the sensing airbag in the deformation sensing component and transmitting the spring lock rod, active deformation excitation of the bottle body is achieved. This can fully reveal defects that are difficult to identify by conventional detection, such as hidden cracks and stress concentration areas. At the same time, the sound-capturing hole of the sleeve component can accurately gather the tiny sound signals generated by defect deformation. Combined with its stable connection with the deformation sensing component, it ensures the multi-dimensional sensing and collaborative detection effect of the acoustic sensing extension probe and the pulsed laser probe, achieving full coverage of both visible and hidden defects.

[0019] 3. The flexible support arm of the inner neck connecting section has elastic telescopic characteristics, which can adaptively adjust to the neck size of different specifications of PE plastic empty bottles and achieve a stable connection. At the same time, with the detachable snap-fit ​​structure between it and the deformation sensing component, the device can easily adapt to the detection needs of PE plastic empty bottles of various capacities and wall thicknesses. There is no need to adjust or replace the core components for different bottle types, which improves the versatility and practical application value of the device.

[0020] 4. By integrating the air hood, air cavity, and air vents into an integrated purging system, the slight expansion of the sensing airbag compresses the air within the air cavity, and the directional spray precisely removes floating dust and fine impurities from the area to be inspected on the bottle body. This pre-treatment function can prevent impurities from interfering with laser deformation monitoring and acoustic signal acquisition at the source, avoiding misjudgments caused by foreign objects. At the same time, the closed air cavity can form pressure linkage feedback through the air vents, capturing the pressure fluctuations corresponding to abnormal deformation of the flexible concave ring in real time, providing an additional pressure monitoring dimension for defect judgment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall front structure of the detection housing of the PE plastic empty bottle defect detection device proposed in this invention; Figure 2 This is a cross-sectional internal structure diagram of the deformation sensing component of a PE plastic empty bottle defect detection device proposed in this invention. Figure 3 This is a schematic diagram of the overall sensing airbag of a PE plastic empty bottle defect detection device proposed in this invention; Figure 4 This is a schematic diagram of the connecting ring of a PE plastic empty bottle defect detection device proposed in this invention; Figure 5 This is a diagram illustrating the inner neck connection section of a PE plastic empty bottle defect detection device proposed in this invention; Figure 6 This is a diagram illustrating the connection of the spring-lock rod frame of a PE plastic empty bottle defect detection device proposed in this invention; Figure 7 This is a schematic diagram of the overall detection structure of a PE plastic empty bottle defect detection device proposed in this invention. Figure 8 This is a schematic diagram of the air cover structure of the PE plastic empty bottle defect detection device proposed in this invention; Figure 9 This is a partial cross-sectional structural diagram of the air cover of a PE plastic empty bottle defect detection device proposed in this invention.

[0022] In the diagram: 1. Detection housing; 101. Transverse support frame; 102. Longitudinal partition frame; 2. Placement cavity; 3. Acoustic sensing extension probe; 4. Fixed base; 5. Pulsed laser probe; 6. Limiting connection frame; 601. Elastic cavity arm; 7. Deformation sensing component; 71. Spring lock rod frame; 711. Inwardly recessed curved end; 712. Folded bottom end; 713. Elastic hinge arm; 72. Sensing airbag; 721. Abutment. 722. Curved surface; 723. Expansion chamber; 8. Support shaft section; 8. Sleeve assembly; 81. Connecting bottle ring; 811. Flexible concave ring; 812. Limiting flange; 813. Expansion section; 82. Inner neck connecting section; 821. Flexible support arm; 83. Sound capture hole; 9. Air cover body; 91. Hook end; 92. Bending and sealing section; 93. Air cavity; 94. Air hole; 95. Folded flexible part; 10. Air injection connector. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] The terms used in this invention, such as "upper," "lower," "left," "right," "middle," and "one," are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0025] Reference Figure 2 , Figure 4 and Figure 5 A device for detecting defects in the body of a PE plastic empty bottle includes a limiting connecting frame 6 fixedly installed on the upper surface of a longitudinal partition frame 102. Both sides of the limiting connecting frame 6 are provided with elastic cavity arms 601. A deformation sensing component 7 is movably engaged with the inner wall of the elastic cavity arm 601. An acoustic sensing extension probe 3 is placed on one side of the deformation sensing component 7. A pulsed laser probe 5 is perpendicularly adapted to the deformation sensing component 7. The deformation sensing component 7 includes a spring-locking rod frame 71 movably engaged with the middle of both sides of the limiting connecting frame 6. The inner end face of the spring-locking rod frame 71 is provided with an inwardly recessed bent end 711, and one end of the spring-locking rod frame 71 is provided with a folded bottom end 712.

[0026] An elastic hinge arm 713 is provided between the bottom end 712 of the folded edge and the middle spring lock rod frame 71. A sensing airbag 72 is connected through the end face of the spring lock rod frame 71 away from the bottom end 712 of the folded edge. The inner arc surface of the sensing airbag 72 is provided with an abutting arc surface 721. The inner arc surface of the sensing airbag 72 is provided with an expansion air chamber 722. The inner arc surface of the abutting arc surface 721 is attached to the surface of the concave bend end 711.

[0027] The spring-loaded lever 71 is a force transmission component acting on the bottle body. Its inner concave bend 711 adopts an arc-shaped fitting design, which can conform to the contour of the bottle body to achieve surface contact force. The folded bottom end 712 of one end of the spring-loaded lever 71 cooperates with the elastic hinge arm 713 to form an elastically rotatable lever structure, providing a basis for subsequent uniform force application. The sensing airbag 72 is the power source for deformation excitation. Its internal expansion air chamber 722 can be inflated or deflated through the air injection connector 10. The abutting arc surface 721 of the outer arc surface fits against the outer side of the spring-loaded lever 71 to ensure that the inflation force can be uniformly transmitted to the spring-loaded lever 71. The support shaft section 723 at the top of the sensing airbag 72 has an annular groove to achieve stable engagement with the sleeve assembly 8 and ensure the synchronous movement of the two.

[0028] In embodiments applying the above technical solutions, The limiting flange 812 at the top of the connecting bottle ring 81 engages with the annular groove of the support shaft section 723 of the sensing airbag 72, ensuring no relative displacement between the bottle and the sensing component during deformation excitation. The flexible concave ring 811 in the middle of the connecting bottle ring 81 is made of flexible material and can fit against the concave curved end 711 of the spring lock rod frame 71, which not only improves the stability of the bottle fixation but also avoids damage to the bottle body caused by rigid contact. The expansion section 813 at the tail end of the connecting bottle ring 81 adopts a flared design to facilitate quick insertion and positioning of the bottle to be detected. The inner neck connecting section 82 is located on the inner arc surface of the connecting bottle ring 81. The flexible support arm 821 on its inner side has elastic telescopic characteristics and can be adaptively adjusted according to the neck size of different specifications of PE plastic empty bottles. The bottle body is centered and positioned through multi-directional elastic abutment to ensure the symmetry of subsequent deformation excitation and detection. The sound-capturing holes 83 are evenly distributed on the outer arc surface of the connecting bottle ring 81 and correspond to the acoustic sensing extension probe 3 to form an acoustic signal transmission channel, which can gather and transmit the tiny acoustic signals generated during the deformation of the bottle body to the acoustic sensor.

[0029] After the bottle body is positioned and fixed, gas at a preset pressure is injected into the expansion chamber 722 of the sensing airbag 72 through the gas injection connector 10. The sensing airbag 72 expands uniformly in the radial direction, and its abutting arc surface 721 simultaneously applies an outward thrust to the spring lock rods 71 ​​on both sides. Since the spring lock rods 71 ​​are hinged to the bottom end 712 of the folded edge through the elastic hinge arm 713, under the action of the thrust, the spring lock rods 71 ​​generate an inward rotation tendency with the elastic hinge arm 713 as the fulcrum. Then, through the concave bend end 711, a uniform annular extrusion force is applied to the flexible concave ring 811 of the connecting bottle ring 81. This extrusion force is transmitted through the connecting bottle ring 81 to the flexible support arm 821 of the inner neck connecting section 82, and finally acts on the bottle body, realizing the flexible and uniform deformation excitation of the bottle body. In the whole process, the expansion amount of the sensing airbag 72 determines the magnitude of the extrusion force, which can be precisely controlled by the gas injection amount to ensure that qualified bottles only produce elastic deformation, while defective areas of defective bottles produce abnormal deformation due to stress concentration.

[0030] Reference Figure 3 and Figure 6 The inner arc surface of the sensing airbag 72 is provided with a support shaft section 723. An annular groove is formed on the inner sidewall of the support shaft section 723. A sleeve assembly 8 is engaged in the annular groove of the support shaft section 723. The sleeve assembly 8 includes a connecting bottle ring 81 that is sleeved into the inner arc surface of the annular groove. A limiting flange 812 is provided at the top of the connecting bottle ring 81, and the limiting flange 812 is movably engaged in the annular groove of the support shaft section 723. A flexible concave ring 811 is provided in the middle of the connecting bottle ring 81, and an expansion section 813 is provided at the tail end of the connecting bottle ring 81. The flexible concave ring 811... The concave surface is adapted to the concave bend 711 in the middle of the spring lock rod frame 71. The inner arc surface of the connecting bottle ring 81 is provided with an inner neck connecting section 82. The inner arc surface of the inner neck connecting section 82 is provided with a flexible support arm 821. The outer arc surface of the connecting bottle ring 81 is provided with a sound-capturing hole 83. The sound-capturing hole 83 corresponds to the acoustic sensing extension probe 3 on one side. The outer arc surface of the sensing airbag 72 is connected to an air injection connector 10. One end of the air injection connector 10 is adapted to the expansion air chamber 722. Several empty plastic bottles are placed in the placement cavity 2 at the bottom of the detection housing 1.

[0031] The concave bend 711 of the spring lock rod 71 indirectly contacts the bottle body through the connecting bottle ring 81 during the force application process. Its function is to transmit uniform extrusion force. During the inspection, the displacement of the spring lock rod 71 is simultaneously monitored by the pulsed laser probe 5. Due to the uniformity of the material of the qualified bottle body, the rotational displacement of the spring lock rods 71 ​​on both sides should remain symmetrical and within the preset range. If there is a defect in the bottle body, the deformation resistance of the defect area is weak, which will cause abnormal deviation in the displacement of the corresponding spring lock rod 71. After the pulsed laser probe 5 captures the abnormal displacement signal, it is transmitted to the processing unit as one of the criteria for defect judgment. At the same time, the elastic deformation characteristics of the elastic hinge arm 713 ensure the stability of the force application of the spring lock rod 71. During the inspection, the laser displacement sensor assists in monitoring the deformation degree of the elastic hinge arm 713 to avoid uneven force application due to hinge arm failure, which would affect the inspection accuracy.

[0032] The connecting ring 81 acts as an intermediate carrier for force transmission and signal transmission. The deformation state of its flexible concave ring 811 can be indirectly monitored by the pulsed laser probe 5. When the deformation of a qualified bottle is uniform, the deformation of the flexible concave ring 811 is symmetrically distributed. If there is a defect in the bottle, the flexible concave ring 811 in the corresponding area will produce local bulges or depressions due to abnormal deformation of the bottle. After the laser signal captures the abnormality, it can locate the approximate area of ​​the defect. The flexible support arm 821 of the inner neck connecting section 82 ensures that the bottle is centered by elastic abutment. During the detection process, if the bottle is not centered, it will cause the displacement of the spring lock rods 71 ​​on both sides to be asymmetrical. By monitoring the displacement symmetry of the spring lock rods 71 ​​by the laser displacement sensor, the positioning accuracy of the flexible support arm 821 can be verified in reverse to avoid detection failure due to positioning offset.

[0033] When the bottle has defects such as cracks or impurities, under the action of circumferential extrusion force, tiny crack propagation sound frequencies of 20-50kHz or material friction sound will be generated in the defect area. These tiny sound signals propagate in the gap between the bottle and the connecting bottle ring 81. Through the converging effect of the sound-capturing hole 83, a directional sound signal channel is formed and transmitted to the corresponding acoustic sensing extension probe 3. The acoustic sensing extension probe 3 converts the sound signal into an electrical signal and transmits it to the processing unit for spectrum analysis. Abnormal sound pattern features are extracted and compared with the preset normal sound pattern threshold to achieve accurate defect judgment. At the same time, the uniform distribution design of the sound-capturing hole 83 ensures that the circumferential sound signal of the bottle is collected without dead angles, improving the comprehensiveness of defect detection.

[0034] Reference Figure 1 and Figure 7A longitudinal partition frame 102 is provided at one end edge of the detection housing 1 near the transverse support frame 101. A placement cavity 2 is provided between the transverse support frame 101 and the longitudinal partition frame 102. An acoustic sensing extension probe 3 is fixedly installed on the upper surface of the transverse support frame 101. A fixed base 4 is fixedly installed on the inner side wall of the detection housing 1 near the longitudinal partition frame 102. A pulsed laser probe 5 is fixedly installed on the upper surface of the fixed base 4 by bolts.

[0035] The acoustic sensing extension probe 3 is used to capture the tiny acoustic signals generated by defects during the deformation of the bottle body, enabling acoustic identification of defects such as hidden cracks and weak material areas. When there are cracks, internal impurities, or stress concentration areas in the bottle body, the defect area will undergo tiny structural changes under the action of circumferential extrusion force, such as interface separation during crack propagation, friction between impurities and bottle material, and plastic deformation of weak areas. These changes will generate tiny acoustic signals in the ultrasonic band with a frequency of 20-50kHz. Since the sound-capturing holes 83 on the outer arc surface of the connecting bottle ring 81 are uniformly distributed in an array and aligned with the sensing end of the acoustic sensing extension probe 3, a directional acoustic signal channel can be formed to gather and efficiently transmit the dispersed tiny acoustic signals to the sensing end of the probe, avoiding attenuation or diffusion of the acoustic signal during propagation and improving the sensitivity of signal capture.

[0036] The core of the pulsed laser probe 5 is used to monitor the deformation differences of the bottle and related components. By quantifying the deformation through optical signals, it can accurately distinguish between uniform and abnormal deformation. The pulsed laser probe 5 is vertically adapted to the deformation sensing component 7, and can be accurately aligned with the bottle surface and key components such as the spring-loaded locking rod 71 and the connecting bottle ring 81. During operation, the laser diode inside the probe emits a high-frequency pulsed laser. The pulse frequency is adjustable to adapt to the detection speed requirements. After being focused by an optical lens, the laser beam forms a laser spot with an extremely small diameter, which is projected onto the target surface of the bottle, the spring-loaded locking rod 71, or the connecting bottle ring 81, ensuring the spatial resolution of the detection. If there are defects on the target surface, such as cracks or weak areas in the bottle, local abnormal deformation will occur, causing a sudden change in the propagation direction of the reflected light in the corresponding area. The converted deformation electrical signal is filtered and then transmitted to the subsequent processing unit to achieve quantified acquisition of deformation data.

[0037] Figure 8 and Figure 9In the induction airbag 72, an air cover 9 is movably engaged with one side of the support shaft section 723. The front end of the air cover 9 is provided with a hook end 91, which is movably engaged with one side of the spring lock rod frame 71. The inner arc surface of the air cover 9 is provided with a bent sealing section 92, which fits against the surface of the flexible concave ring 811. An air cavity 93 is provided between the air cover 9 and the bent sealing section 92. An air hole 94 is opened on the side of the air cover 9 near the air cavity 93. The tail end of the air cover 9 is provided with a folded flexible part 95, which extends into the interior of the flexible concave ring 811. A hole corresponding to the air hole 94 is opened on one side of the flexible concave ring 811. The outer arc surface of the air cover 9 is adapted to the induction airbag 72.

[0038] A small amount of gas is injected into the expansion chamber 722 of the sensing airbag 72 through the gas injection connector, causing the sensing airbag 72 to expand slightly and squeeze the air cover 9, thereby compressing the air cavity 93 between the air cover 9 and the flexible concave ring 811. After being compressed, the air in the air cavity 93 is quickly discharged along the air hole 94 of the air cover 9 and is directionally sprayed into the area to be detected on the bottle body through the corresponding hole on one side of the flexible concave ring 811, thereby cleaning the floating dust and fine impurities on the bottle body surface. This pretreatment step can avoid floating dust from interfering with subsequent sound signal acquisition and laser deformation monitoring, and avoid misjudgment caused by impurities.

[0039] After the floating dust is blown away, some of the gas inside the sensing airbag 72 is discharged, causing it to contract slightly. Then, the bottle body and the connecting assembly 8 are precisely positioned. At this time, the gas cover 9 is movablely engaged with the sensing airbag 72 through the support shaft section 723. Its outer arc surface is precisely fitted with the contour of the sensing airbag 72, ensuring the structural consistency of the two after connection. At the same time, the hook end 91 at the front end of the gas cover 9 is engaged with one side of the spring lock rod frame 71, forming a mechanical limit to prevent the gas cover 9 from shifting during deformation excitation. The bent sealing section 92 of the inner arc surface of the gas cover 9 is tightly fitted to the surface of the flexible concave ring 811 connecting the bottle ring 81, and the folded flexible part 95 at the tail end extends into the interior of the flexible concave ring 811. Through flexible compression, the gas cover 9 and the flexible concave ring 811 are sealed and fitted, reconstructing the relatively closed air cavity 93, and the air hole 94 is precisely aligned with the hole of the flexible concave ring 811.

[0040] When gas is injected into the expansion chamber 722 of the sensing airbag 72 through the gas injection connector, the sensing airbag 72 expands uniformly in the radial direction. On the one hand, it pushes the spring lock rod 71 by its own abutting arc surface, and on the other hand, it transmits part of the expansion pressure to the air cover 9 through the contact surface with the air cover body 9. Since the air cover body 9 is linked with the spring lock rod 71 through the hook end 91, it synchronously drives the spring lock rod 71 to rotate inward with the elastic hinge arm 713 as the fulcrum under the pressure. This causes the concave bend end 711 of the spring lock rod 71 to apply a uniform annular extrusion force to the bottle body through the flexible concave ring 811, which can effectively disperse the pressure, avoid local stress concentration, and further improve the uniformity of deformation excitation.

[0041] Meanwhile, under the expansion pressure of the sensing airbag 72, the bending sealing section 92 and the flexible edge 95 of the air cover body 9 further improve their fit with the flexible concave ring 811, enhancing the sealing performance of the air cavity 93. The air cavity 93 forms a slight pressure linkage with the outside through the air hole 94, which can provide real-time feedback on the deformation state of the flexible concave ring 811. If there are weak material areas or hidden cracks in the bottle body, the deformation of the flexible concave ring 811 in the corresponding area will be abnormal, causing the pressure inside the air cavity 93 to fluctuate. This fluctuation can help determine the bottle body defects, forming a multi-dimensional pressure monitoring supplement.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for detecting defects in the body of empty PE plastic bottles, comprising: The detection housing (1) is characterized in that a transverse support frame (101) is connected to the top of the inner side wall of the detection housing (1), a longitudinal partition frame (102) is provided at one end edge of the detection housing (1) near the transverse support frame (101), and a placement cavity (2) is provided between the transverse support frame (101) and the longitudinal partition frame (102). An acoustic sensing extension probe (3) is fixedly installed on the upper surface of the transverse support frame (101). A fixed base (4) is fixedly installed on the inner side wall of the detection housing (1) near the longitudinal partition frame (102). A pulsed laser probe (5) is fixedly installed on the upper surface of the fixed base (4) by bolts. The upper surface of the longitudinal partition frame (102) is fixedly installed with a limiting connecting frame (6). Both sides of the limiting connecting frame (6) are provided with elastic cavity arms (601). The inner side wall of the elastic cavity arm (601) is movably engaged with a deformation sensing component (7). The acoustic sensing extension probe (3) is placed on one side of the deformation sensing component (7). The pulsed laser probe (5) is vertically adapted to the deformation sensing component (7).

2. The device for detecting defects in the body of an empty PE plastic bottle according to claim 1, characterized in that, The deformation sensing component (7) includes a spring lock rod frame (71) that is movable and connected to the middle of both sides of the limiting connecting frame (6). The inner end face of the spring lock rod frame (71) is provided with an inwardly recessed bent end (711), and one end of the spring lock rod frame (71) is provided with a folded bottom end (712).

3. The device for detecting defects in the body of an empty PE plastic bottle according to claim 2, characterized in that, An elastic hinge arm (713) is provided between the bottom end of the folded edge (712) and the spring lock rod frame (71) in the middle. A sensing airbag (72) is connected through the end face of the spring lock rod frame (71) away from the bottom end of the folded edge (712).

4. The device for detecting defects in the body of an empty PE plastic bottle according to claim 3, characterized in that, The inner arc surface of the sensing airbag (72) is provided with an abutting arc surface (721), and the inner arc surface of the sensing airbag (72) is provided with an expansion air chamber (722). The inner arc surface of the abutting arc surface (721) is attached to the surface of the concave bend end (711).

5. The device for detecting defects in the body of an empty PE plastic bottle according to claim 4, characterized in that, The top of the inner arc surface of the sensing airbag (72) is provided with a support shaft section (723), and the inner sidewall of the support shaft section (723) is provided with an annular groove. A sleeve assembly (8) is snapped into the annular groove of the support shaft section (723).

6. The device for detecting defects in the body of an empty PE plastic bottle according to claim 5, characterized in that, The sleeve assembly (8) includes a connecting bottle ring (81) that is sleeved into the inner arc surface of the annular groove. The top end of the connecting bottle ring (81) is provided with a limiting flange (812), which is movably engaged into the annular groove of the support shaft section (723).

7. The device for detecting defects in the body of an empty PE plastic bottle according to claim 6, characterized in that, The connecting bottle ring (81) has a flexible concave ring (811) in the middle and an expansion section (813) at the tail end. The concave surface of the flexible concave ring (811) is adapted to the concave bent end (711) in the middle of the spring lock rod frame (71).

8. The device for detecting defects in the body of an empty PE plastic bottle according to claim 7, characterized in that, The inner arc surface of the connecting bottle ring (81) is provided with an inner neck connecting section (82), the inner arc surface of the inner neck connecting section (82) is provided with a flexible support arm (821), and the outer arc surface of the connecting bottle ring (81) is provided with a sound-capturing hole (83).

9. The device for detecting defects in the body of an empty PE plastic bottle according to claim 8, characterized in that, The sound-capturing hole (83) corresponds to the acoustic sensing extension probe (3) on one side. The outer arc surface of the sensing airbag (72) is connected to the air injection connector (10). One end of the air injection connector (10) is adapted to the expansion chamber (722). Several empty plastic bottles are provided in the placement cavity (2) at the bottom of the detection housing (1).

10. A device for detecting defects in the body of an empty PE plastic bottle according to claim 5, characterized in that, An air cover (9) is movably engaged with one side of the support shaft section (723) inside the sensing airbag (72). The front end of the air cover (9) is provided with a hook end (91), which is movably engaged with one side of the spring lock rod frame (71). The inner arc surface of the air cover (9) is provided with a bent sealing section (92), which fits against the surface of the flexible concave ring (811). The air cover (9) and the bent sealing section... An air cavity (93) is provided between (92). An air hole (94) is provided on the side of the air cover (9) near the air cavity (93). A flexible folded edge (95) is provided at the tail end of the air cover (9). The flexible folded edge (95) extends into the interior of the flexible concave ring (811). A hole corresponding to the air hole (94) is provided on one side of the flexible concave ring (811). The outer arc surface of the air cover (9) is adapted to the sensing airbag (72).

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