A conveying device and a surface defect detection device

Abstract

The application discloses a conveying device and a surface defect detection device, and belongs to the technical field of printed circuit manufacturing equipment. In the conveying device, a first negative pressure body, a positive pressure body and a second negative pressure body are arranged along the conveying direction from the first conveying mechanism to the second conveying mechanism. The first negative pressure body provides negative pressure suction force to the first air holes on the first conveying belt to flatten the passing flexible sheet material. The second negative pressure body provides negative pressure suction force to the second air holes on the second conveying belt to transition the flexible sheet material from the first conveying belt to the second conveying belt and flatten the passing second flexible sheet material. The positive pressure body provides positive pressure blowing force to the first air holes to pre-lift the flexible sheet material. In one aspect, the flexible sheet material is more conveniently adsorbed on the second conveying belt, and the required negative pressure of the second negative pressure body is reduced. In another aspect, the bending angle of the flexible sheet material during the transition from the first conveying belt to the second conveying belt is reduced, and the phenomenon of creases on the flexible sheet material due to the excessively large bending angle is avoided.

Description

Technical Field

[0001] This application belongs to the field of printed circuit manufacturing equipment technology, and particularly relates to a conveying device and a surface defect detection device. Background Technology

[0002] In PCB manufacturing, surface defect inspection is required for flexible sheets such as PP boards, copper foil boards, or CCL boards to screen out defective products that meet the defect standards. Surface defect inspection of these specialized flexible sheets is mostly performed using a CCD camera.

[0003] Patent application number 201822184722.3 discloses a double-sided visual inspection device for workpieces. By setting up two conveyor belts, a flipping device is used to flip the workpiece 180° from one conveyor belt to the other. On the first conveyor belt, two CCD cameras, one first and one second, are used to inspect the surface and sides of the workpiece, while on the second conveyor belt, a third CCD camera is used to inspect the back of the workpiece. This setup not only allows for all-round inspection of the workpiece surface, but also allows the conveyor belts to work continuously without interruption, thus improving the efficiency of production inspection.

[0004] However, if this device is used to inspect the flexible sheet in the PCB manufacturing process, the flexible sheet is prone to deformation and creases or breakage during the flipping process, which will cause the flexible sheet to be detected as a defective product by the third CCD camera. Summary of the Invention

[0005] This application aims to at least partially solve the technical problem that current visual inspection devices cause deformation, creases, or breakage of flexible sheets due to deformation when flipping the sheets during transport. To this end, this application provides a transport device and a surface defect detection system.

[0006] This application provides a conveying device for conveying flexible sheets, comprising: A first conveying mechanism, the first conveying mechanism having a first conveyor belt, a plurality of first air holes distributed on the first conveyor belt, and a first negative pressure body fixed below the first conveyor belt; A second conveying mechanism has a second conveyor belt with multiple second air holes distributed on it. A portion of the second conveyor belt is located above the first conveyor belt, and a second negative pressure body is fixed above the second conveyor belt. A positive pressure body is fixed below the first conveyor belt, and at least a portion of the positive pressure body is located directly below the second conveyor belt. Along the conveying direction of the flexible sheet, the first negative pressure body, the positive pressure body, and the second negative pressure body are arranged in sequence.

[0007] Optionally, to better implement this application, at least a portion of the positive pressure body is located directly below the second negative pressure body.

[0008] Optionally, to better realize this application, the distance between the positive pressure body and the first conveyor belt is adjustable.

[0009] Optionally, to better realize this application, the positive pressure body supports the first conveyor belt.

[0010] Optionally, to better implement this application, at least one first air hole group is distributed on the first conveyor belt. The first air hole group includes a plurality of first air holes that are uniformly and spaced apart along a first straight line. The first straight line is parallel to the conveying direction of the first conveyor belt. An air outlet hole is provided on the top of the positive pressure body. The air outlet hole is located directly below the first straight line.

[0011] Optionally, to better implement this application, a guide plate is fixed to the top of the positive pressure body, and a guide groove is formed on the top surface of the guide plate. The length direction of the guide groove is parallel to the first straight line, and the guide groove is located directly below the first straight line. The length of the guide groove is greater than or equal to the distance between two adjacent air outlet holes in the first straight line, and the bottom of each guide groove is connected to at least one air outlet hole.

[0012] Optionally, to better implement this application, the bottom of each of the air guide grooves is connected to an air outlet hole, and the air outlet hole is located in the middle of the bottom of the air guide groove.

[0013] Optionally, to better realize this application, along the conveying direction of the first conveyor belt, the air guide plate is provided with a first bending portion and a second bending portion formed by bending downwards on both sides, and the air guide plate is limited to the positive pressure body by the first bending portion and the second bending portion.

[0014] Optionally, to better implement this application, the conveying device further includes an identification device. Along the conveying direction of the flexible sheet, the identification device is disposed between the first negative pressure body and the positive pressure body. The distance between the identification device and the positive pressure body is less than the length of the flexible sheet. When the identification device identifies the flexible sheet, the positive pressure body provides positive pressure gas to the first conveyor belt.

[0015] A surface defect detection device includes the aforementioned conveying device, a first camera, and a second camera. The first camera is positioned above the first conveyor belt and faces the first negative pressure body, while the second camera is positioned below the second conveyor belt and faces the second negative pressure body.

[0016] Compared with the prior art, this application has the following advantages: The conveying device provided in this application includes a first negative pressure body, a positive pressure body, and a second negative pressure body arranged along the conveying direction from the first conveying mechanism to the second conveying mechanism. By fixing the first negative pressure body below the first conveyor belt of the first conveying mechanism, negative pressure suction is provided to the first air holes on the first conveyor belt to flatten the passing flexible sheet, thereby enabling the first camera to complete the detection of defects on the upper surface of the flexible sheet. By fixing the second negative pressure body above the second conveyor belt of the second conveying mechanism, negative pressure suction is provided to the second air holes on the second conveyor belt to transition the flexible sheet from the first conveyor belt to the second conveyor belt, thereby flattening and conveying the passing flexible sheet, thereby enabling the second camera to complete the detection of defects on the lower surface of the flexible sheet.

[0017] By fixing a positive pressure body on the first conveyor belt and providing positive pressure blowing force to the first air hole, the passing flexible sheet is pre-lifted. On the one hand, this facilitates the flexible sheet being adsorbed onto the second conveyor belt and reduces the amount of negative pressure required by the second negative pressure body. On the other hand, it can also reduce the bending angle of the flexible sheet during the transition from the first conveyor belt to the second conveyor belt, avoiding the phenomenon of creases caused by excessive bending angle. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the surface defect detection device is shown. Figure 2 It shows Figure 1 Schematic diagram of the conveyor system; Figure 3 It shows Figure 2 Front view of the first and second conveying mechanisms; Figure 4 It shows Figure 3 A magnified view of a section at point B in the middle; Figure 5 It shows Figure 3 Schematic diagram of a neutral pressure body; Figure 6 A schematic diagram of the working areas of the first negative pressure body, the second negative pressure body, and the positive pressure body is shown. Figure 7 This diagram illustrates a state in which a flexible sheet transitions from a first conveying mechanism to a second conveying mechanism. Figure 8This diagram illustrates another state of the flexible sheet transitioning from the first conveying mechanism to the second conveying mechanism.

[0020] Figure label: 10 - Conveying device; 20 - First camera; 30 - Second camera; 100-First conveying mechanism; 110-First conveyor belt; 120-First drive mechanism; 130-First negative pressure body; 141-Identification device; 150-Positive pressure body; 151-Air outlet; 152-Waist-shaped groove; 160-Air guide plate; 161-Air guide groove; 162-Bending part; 200 - Second conveying mechanism; 210 - Second conveyor belt; 220 - Second drive mechanism; 230 - Second negative pressure body; 250 - Second support; 260 - Adjusting component; 261 - Adjusting bolt; 262 - Pad block; 300 - Frame; 310 - First support frame. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that all directional indications in the embodiments of this invention are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. In this invention, unless otherwise explicitly specified and limited, the terms "connection" and "fixed" should be interpreted broadly. For example, "fixed" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction relationship between two components, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances. In addition, the descriptions involving "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] This application is described below with reference to the accompanying drawings and specific embodiments: This application provides a surface defect detection device that can be installed on a PCB production conveyor line to detect surface defects in flexible sheets such as PP boards, copper foil boards, or CCL boards that have passed through the device.

[0024] Specifically, the structure of the aforementioned surface defect detection device is as follows: Figures 1 to 3As shown, the system includes a conveying device 10, a first camera 20, and a second camera 30. The conveying device 10 is used to convey the aforementioned flexible sheet. The flexible sheet moves under the action of the conveying device 10, forming a total conveying path. The first camera 20 is used to capture and detect defects on the upper surface of the flexible sheet, and the second camera 30 is used to capture and detect defects on the lower surface of the flexible sheet. Since it is necessary to detect surface defects on both the upper and lower surfaces of the flexible sheet separately, and some flexible sheets naturally exhibit corner warping or curling, the conveying device 10 must ensure that when the flexible sheet reaches the shooting area of ​​the first camera 20, the upper surface of the flexible sheet faces the first camera 20, and there are no obstructions between the upper surface of the flexible sheet and the first camera 20, and the flexible sheet is in a flat state. Similarly, when the flexible sheet reaches the shooting area of ​​the second camera 30, the lower surface of the flexible sheet faces the second camera 30, and there are no obstructions between the lower surface of the flexible sheet and the first camera 20, and the flexible sheet is in a flat state.

[0025] Specifically, in this embodiment, the first camera 20 is fixed to the frame 300 via the first support bracket 310, and the second camera 30 is directly fixed to the frame 300, so that the first camera 20 and the second camera 30 can move as a whole with the frame 300. Of course, without considering overall movement, the first camera 20 and the second camera 30 can also be fixed in other locations, such as a wall. The specific working principle of the first camera 20 and the second camera 30 in photographing the surface of the flexible sheet and detecting surface defects of the flexible sheet is a conventional technique in the art, and therefore will not be described in detail in this embodiment.

[0026] Below, this application provides a detailed description of a specific embodiment of the conveying device 10.

[0027] This application provides a conveying device 10, the structure of which is as follows: Figure 2-4 As shown, the system includes a frame 300 and a first conveying mechanism 100 and a second conveying mechanism 200 fixed on the frame 300. The flexible sheet is conveyed from the first conveying mechanism 100 to the second conveying mechanism 200.

[0028] The first conveying mechanism 100 includes a first conveyor belt 110 and a first drive mechanism 120 for driving the first conveyor belt 110 to move cyclically. The conveying structure of the first conveying mechanism 100 can be a pulley mechanism, in which case the first conveyor belt 110 is a conveyor belt within the pulley mechanism; alternatively, the first conveying mechanism 100 can be a chain plate mechanism, in which case the first conveyor belt 110 is a conveyor chain plate. The first drive mechanism 120 includes a drive motor and a reducer. Both the conveyor chain plate and the conveyor belt can support the flexible sheet material, ensuring that the first conveyor belt 110 has a flat conveying surface.

[0029] When the first conveying mechanism 100 conveys the flexible sheet, the lower surface of the flexible sheet contacts the upper surface of the first conveyor belt 110. Therefore, by placing the first camera 20 above the first conveyor belt 110, it is possible to capture images and identify defects on the upper surface of the first conveyor belt 110. The movement path of the flexible sheet in the first conveying mechanism 100 is the first conveying path of the flexible sheet, which is part of the total conveying path of the flexible sheet. In this embodiment, the first conveying path is a straight line. In this embodiment, the flexible sheet conveyed by the conveying device 10 is one of the PP board, copper foil board, or CCL board used in PCB boards. The flexible sheet is thin and lightweight. Therefore, the first conveyor belt 110 in the first conveying mechanism 100 is set horizontally so that the surface of the first conveyor belt 110 carrying the flexible sheet is also in a horizontal state, reducing the relative displacement between the flexible sheet and the first conveyor belt 110 during the conveying process. Of course, it should be noted that in some alternative embodiments, if the flexible sheet conveyed by the conveying device 10 is heavy, the first conveyor belt 110 can be tilted to reduce the relative displacement between the flexible sheet and the first conveyor belt 110 during the conveying process.

[0030] Furthermore, to ensure the flexible sheet remains flat when entering the imaging area of ​​the first camera 20, this embodiment provides multiple first air holes on the first conveyor belt 110 for gas flow. Additionally, a first negative pressure body 130 is positioned below the first conveyor belt 110. Specifically, the first negative pressure body 130 is located below the first conveying path and does not move synchronously with the first conveyor belt 110. The first negative pressure body 130 provides negative pressure to the first air holes on the first conveyor belt 110, allowing the air holes to exert an adsorption force on the upper surface of the first conveyor belt 110, forming a... Figure 6 The first negative pressure area is shown. The flexible sheet will pass through the first negative pressure area under the conveying action of the first conveyor belt 110, and the part of the flexible sheet located in the first negative pressure area will adhere to the upper surface of the first conveyor belt 110 under the action of negative pressure, so that the flexible sheet is at least in a flat state in the first area.

[0031] In the surface defect detection device, when the upper surface of a flexible sheet needs to be inspected, the first camera 20 is positioned below the first conveyor belt 110, facing the first negative pressure body 130. Since the first camera 20 and the first negative pressure body 130 are located on opposite sides of the first conveyor belt 110, the shooting range of the first camera 20 falls within the first negative pressure area, thus capturing the upper surface of the flexible sheet in a flat state. This prevents the flexible sheet from being bent and affecting the detection accuracy of the first camera 20. Because the flexible sheet needs to be continuously conveyed, the first negative pressure body 130 is usually in a normally open state when the conveyor device 10 is in operation, so that the first negative pressure body 130 can continuously adsorb and flatten the flexible sheet passing through the first negative pressure area.

[0032] It should be noted that in this embodiment, the first negative pressure body 130 is connected to a negative pressure source (not shown in the figure) via a pipe and generates negative pressure under the action of the negative pressure source. The first negative pressure body 130 is provided with holes to allow at least a portion of the negative pressure generated by the negative pressure source to act on the first air holes. Since the flexible sheet needs to be continuously conveyed, the first negative pressure body 130 is usually in a normally open state when the conveying device 10 is in operation, so that the first negative pressure body 130 can continuously adsorb and flatten the flexible sheet passing through the first negative pressure area.

[0033] The second conveying mechanism 200 includes a second conveyor belt 210 and a second drive mechanism 220 for driving the second conveyor belt 210 to move cyclically. The second conveying mechanism 200 can be one of a pulley mechanism and a chain plate mechanism. In this embodiment, both the first conveying mechanism 100 and the second conveying mechanism 200 are pulley mechanisms. A portion of the surface of the second conveyor belt 210 is located above the first conveyor belt 110, so that the second conveyor belt 210 has a projection on the first conveyor belt 110. The gap between the second conveyor belt 210 and the first conveyor belt 110 allows a flexible sheet to pass through.

[0034] To allow the flexible sheet to be conveyed by the second conveyor 200 after entering the gap, instead of the first conveyor mechanism 100, multiple second air holes are provided on the second conveyor belt 210 in this embodiment, allowing gas flow. Furthermore, a second negative pressure body 230 is provided within the second conveyor mechanism 200, located above the second conveyor belt 210, and does not move synchronously with the second conveyor belt 210. The second negative pressure body 230 provides negative pressure to the second air holes on the second conveyor belt 210, enabling the second air holes, under the negative pressure of the second negative pressure body 230, to provide an adsorption force to the lower surface of the second conveyor belt 210, and to form a similar effect on the upper surface of the first conveyor belt 110. Figure 6The second negative pressure region is shown. One end of this negative pressure region is located in the gap between the first conveyor belt 110 and the second conveyor belt 210. After the flexible sheet enters this gap under the conveying of the first conveyor belt 110, it will gradually enter the second negative pressure region. Subsequently, the flexible sheet will be adsorbed onto the lower surface of the second conveyor belt 210 under the negative pressure of the second negative pressure body 230. Under the combined action of the second negative pressure body 230 and the second conveyor belt 210, the flexible sheet is conveyed within the second conveying mechanism 200. The movement path of the flexible sheet in the second conveying mechanism 200 is the second conveying path of the flexible sheet, which is part of the total conveying path of the flexible sheet. In this embodiment, the two conveying paths are straight lines, and the first conveyor belt 110 and the second conveyor belt 210 are parallel. The above-mentioned second negative pressure body 230 being above the second conveyor belt 210 means that the second negative pressure body 230 is located above the second conveying path.

[0035] In the surface defect detection device, when it is necessary to inspect the lower surface of the flexible sheet, the second camera 30 is positioned below the second conveyor belt 210, facing the second negative pressure body 230. Since the second camera 30 and the second negative pressure body 230 are located on opposite sides of the second conveyor belt 210, the shooting range of the second camera 30 falls within the first negative pressure area, thus capturing the lower surface of the flexible sheet in a flat state. Therefore, the second negative pressure body 230 can both work with the second conveyor belt 210 to transport the flexible sheet and work with the second camera 30 to detect small surface defects on the flexible sheet.

[0036] It should be noted that in this embodiment, the second negative pressure body 230 is connected to a negative pressure source (not shown in the figure) via a pipe and generates negative pressure under the action of the negative pressure source. The second negative pressure body 230 is provided with holes or slots to allow at least a portion of the negative pressure generated by the negative pressure source to act on the second air vent. Since the flexible sheet needs to be continuously conveyed, the first negative pressure body 130 is usually in a normally open state when the conveying device 10 is in operation, so that the second negative pressure body 230 can continuously adsorb and flatten the flexible sheet passing through the second negative pressure area, while also preventing the flexible sheet from falling off the second conveyor belt 210.

[0037] The flexible sheet is conveyed in the first conveyor mechanism 100 via the first conveyor belt 110, and in the second conveyor mechanism 200 via the second conveyor belt 210 and the second negative pressure body 230. The flexible sheet is not flipped during the entire conveying process, thus avoiding the technical problem of creases or breakage caused by deformation during flipping. Furthermore, in the first conveyor mechanism 100, the first negative pressure body 130 and the first camera 20 work together to detect surface defects on the upper surface of the flexible sheet. In the second conveyor mechanism 200, the second negative pressure body 230 and the second camera 30 work together to detect surface defects on the lower surface of the flexible sheet. Thus, while continuously conveying the flexible sheet, the upper and lower surfaces of the flexible sheet are also inspected. The conveying device 10 can identify defects on the upper and lower surfaces of the flexible sheet without flipping it during the conveying process, in conjunction with the first camera 20 and the second camera 30. Furthermore, since the flipping action and flipping mechanism are eliminated, the structural complexity of the conveying device 10 is reduced on the one hand, and the space occupied by the entire conveying in the height direction is also reduced on the other hand, and the slippage or loss of the flexible sheet during the flipping process can be avoided.

[0038] Based on this, the inventors conducted further research and discovered that when using the aforementioned conveying device 10, during the process of the second negative pressure body 230 adsorbing the flexible sheet from the first conveyor belt 110 to the second conveyor belt 210, due to the certain gap between the flexible sheet and the second conveyor belt 210, the adsorption force provided by the second negative pressure body 230 cannot be fully applied to the flexible sheet. Therefore, the second negative pressure body 230 needs to provide a larger negative pressure adsorption force to adsorb the flexible sheet onto the second conveyor belt 210, thus requiring a larger power. The larger the gap between the flexible sheet and the second conveyor belt 210, the greater the adsorption force required by the second negative pressure body 230. Furthermore, since the second negative pressure body 230 needs to be started for a long time, the cost of continuous operation of the second negative pressure body 230 is relatively high. Additionally, as... Figure 8 As shown, when a portion of the flexible sheet is adsorbed onto the second conveyor belt 210 by the second negative pressure body 230, the other portion of the flexible sheet will naturally droop. This state may cause creases to form on the flexible sheet due to natural drooping.

[0039] In view of this, this embodiment adds a positive pressure body 150 to the structure of the conveying device 10 described above. The positive pressure body 150 is fixed below the conveying path of the first conveyor belt 110, and the positive pressure body 150 does not move synchronously with the second conveyor belt 210. Specifically, the positive pressure body 150 can blow air outward to generate positive pressure. The gas blown out by the positive pressure body 150 reaches the upper surface of the first conveyor belt 110 after passing through the first air hole, and forms a positive pressure area on the upper surface of the first conveyor belt 110. The portion of the flexible sheet conveyed on the first conveyor belt 110 that enters the positive pressure area will be blown away from the upper surface of the first conveyor belt 110. Along the conveying path of the flexible sheet in the conveying device 10, the positive pressure body 150 is located between the first negative pressure body 130 and the second negative pressure body 230. The flexible sheet will sequentially pass through the first negative pressure area corresponding to the first negative pressure body 130, the positive pressure area corresponding to the positive pressure body 150, and the negative pressure area corresponding to the second negative pressure body 230.

[0040] It should be noted that in this embodiment, the positive pressure body 150 is connected to a positive pressure source (not shown in the figure) via a pipe. The positive pressure source can be an air compressor or an air pipe connected to an air compressor; this embodiment does not impose any specific limitations on this. The top of the positive pressure body 150 is provided with an air outlet hole 151 to blow out positive pressure gas through the air outlet hole 151. At least a portion of the blown positive pressure gas acts on the first air hole.

[0041] At least a portion of the positive pressure body 150 is located directly below the second conveyor belt 210. Specifically, at least a portion of the positive pressure body 150 is located directly below the conveying path formed by the flexible sheet on the second conveyor belt 210. After the flexible sheet enters the positive pressure area formed by the positive pressure body 150, the flexible sheet is blown away from the first conveyor belt 110, causing the flexible sheet to be pre-lifted. During this process, the first conveyor belt 110 continues to transport the flexible sheet, so that the pre-lifted portion of the flexible sheet enters the second negative pressure area of ​​the second negative pressure body 230. Under the negative pressure adsorption of the second negative pressure body 230, the flexible sheet adheres to the lower surface of the second conveyor belt 210, completing the transition process of the flexible sheet from the first conveyor belt 110 to the second conveyor belt 210. During this transition process, since the flexible sheet is attached to the first conveyor belt 110, the positive pressure body 150 only requires a small amount of power to blow the flexible sheet away from the first conveyor belt 110. Blowing the flexible sheet away from the first conveyor belt 110 also reduces the distance between the flexible sheet and the second conveyor belt 210. This allows the second negative pressure body 230 to use only a small blowing force to attract the pre-lifted portion of the flexible sheet onto the second conveyor belt 210, reducing the suction force required by the second negative pressure body 230 and avoiding the problem of some flexible sheets failing to be attracted onto the second conveyor belt 210 after changes in the type and thickness of the flexible sheet. Furthermore, because the flexible sheet is pre-lifted under the action of the positive pressure body 150, the state of the flexible sheet transitioning from the first conveyor belt 110 to the second conveyor belt 210 is as follows: Figure 7 As shown, the lifting curve of the flexible sheet is relatively gentle at this time, and the bending angle of the flexible sheet is less than [missing information]. Figure 8 The bending angle of the flexible sheet is not set when the positive pressure body is 150, which can avoid the problem of creases in the flexible sheet caused by excessive bending angle.

[0042] Meanwhile, since at least a portion of the positive pressure body 150 is located directly below the second conveyor belt 210, even if the positive pressure blowing force provided by the positive pressure body 150 is too large, the second conveyor belt 210 will limit the pre-lifting height of the flexible sheet, so that the flexible sheet can eventually move along the second conveyor belt 210.

[0043] Furthermore, at least a portion of the aforementioned positive pressure body 150 is located directly below the second negative pressure body 230, such that the positive pressure region of the positive pressure body 150 and the negative pressure region of the second negative pressure body 230 intersect at least partially. When the portion of the flexible sheet pre-lifted by the positive pressure body 150 enters the intersection of the positive and negative pressure regions, the pre-lifted portion of the flexible sheet can continue to rise under the action of the second negative pressure body 230 until it adheres to the first conveyor belt 110. This arrangement ensures that at the intersection, the blowing force of the positive pressure body 150 and the adsorption force of the negative pressure body can simultaneously act on the same location of the flexible sheet, further reducing the power consumption of the second negative pressure body 230.

[0044] Preferably, the positive pressure body 150 is located directly below the second negative pressure body 230. This allows the blowing force of the positive pressure body 150 on the flexible sheet to coincide with the suction force of the second negative pressure body 230 on the flexible sheet, making it easier for the flexible sheet to be adsorbed onto the second conveyor belt 210.

[0045] It should be noted that in this embodiment, the magnitude of the positive pressure generated by the positive pressure body 150 is adjustable, and can be adjusted to zero, i.e., the positive pressure body 150 is turned off. By adjusting the positive pressure of the positive pressure body 150, the pre-lifting height of the flexible sheet can be changed accordingly. The greater the positive pressure, the higher the flexible sheet is pre-lifted. When the flexible sheet is closer to the second conveyor belt 210, it is relatively easier for the second negative pressure body 230 to adsorb the flexible sheet onto the second conveyor belt 210.

[0046] In addition, the conveying device 10 also includes an identification device 141. Along the conveying path of the flexible sheet, the identification device 141 is disposed between the first negative pressure body 130 and the positive pressure body 150. The horizontal distance between the identification device 141 and the positive pressure body 150 is less than the length of the flexible sheet. When the identification device 141 identifies the flexible sheet, the positive pressure body 150 blows air onto the first conveyor belt 110. The positive pressure body 150 can stop blowing air onto the first conveyor belt 110 when the flexible sheet has completely left the identification area of ​​the identification device 141, or after the flexible sheet has bent away from the identification area of ​​the identification device 141, and then stops after a certain delay. By obtaining the position of the flexible sheet through the identification device 141, and using this position to control the blowing or stopping of the positive pressure body 150 through the controller, the energy consumption of the positive pressure source providing positive pressure to the positive pressure body 150 can be reduced while ensuring that the positive pressure body 150 can act on each flexible sheet.

[0047] It should be noted that the identification device 141 in this embodiment is a photoelectric sensor and a controller. The photoelectric sensor is connected to the controller, and the controller is electrically connected to the solenoid valve or positive pressure source on the positive pressure body 150 pipeline, so as to identify the flexible sheet through the photoelectric sensor and control the start / stop of the positive pressure body 150 by the controller. Since the flexible sheet in the PCB is relatively lightweight, the identification device 141 composed of a photoelectric sensor and a controller is suitable. Of course, the identification device 141 can also be a combination of a piezoelectric sensor and a controller, or a combination of an ultrasonic sensor and a controller, etc.

[0048] Furthermore, in this embodiment, the distance between the positive pressure body 150 and the first conveyor belt 110 is adjustable. By adjusting the distance between the positive pressure body 150 and the first conveyor belt 110, the magnitude of the positive pressure of the positive pressure body 150 can be adjusted without changing the magnitude of the output airflow of the positive pressure body 150, thereby adjusting the height at which the flexible sheet is blown up to a certain extent. When the positive pressure body 150 is in contact with the first conveyor belt 110, all the airflow generated by the positive pressure body 150 is discharged from the first air hole on the first conveyor belt 110, and at this time, the blowing force of the positive pressure body 150 on the flexible sheet is the greatest; when the distance between the positive pressure body 150 and the first conveyor belt 110 gradually increases, only a portion of the airflow generated by the positive pressure body 150 is discharged from the first air hole on the first conveyor belt 110, and at this time, the blowing force of the positive pressure body 150 on the flexible sheet gradually decreases.

[0049] It should be noted that in this embodiment, the adjustment of the distance between the positive pressure body 150 and the first conveyor belt 110 is achieved by adjusting the position of the positive pressure body 150. Specifically, the positive pressure body 150 and the frame 300 are connected by a matching slot 152 and bolts to adjust the height of the positive pressure body 150, thereby adjusting the distance between the positive pressure body 150 and the first conveyor belt 110. Of course, in some optional embodiments, the distance between the positive pressure body 150 and the first conveyor belt 110 can also be adjusted by screw lifting or by electric drive.

[0050] Preferably, the upper surface of the positive pressure body 150 is in contact with the first conveyor belt 110, so that the positive pressure body 150 is supported by the first conveyor belt 110. The holes on the positive pressure body 150 are set on the upper surface of the positive pressure body 150. After the positive pressure body 150 is in contact with the first conveyor belt 110, the gas blown out by the positive pressure body 150 can be discharged from the first air hole to the maximum extent. At the same time, after the positive pressure body 150 supports the first conveyor belt 110, it can prevent the first conveyor belt 110 from swinging downward, thereby reducing the swing amplitude after the first conveyor belt 110 becomes loose.

[0051] During the process of the positive pressure body 150 blowing air into the first air hole, if the top of the positive pressure body 150 is set as an open structure, although the gas blown by the positive pressure body 150 into the first air hole can be continuous and uninterrupted, the air outlet area of ​​the positive pressure body 150 with the open structure is large, and the positive pressure body 150 and the first conveyor belt 110 cannot be completely sealed. This will result in a smaller gas pressure acting in the first air hole, affecting the blowing height of the positive pressure body 150 onto the flexible sheet.

[0052] In view of this, this embodiment provides an air outlet 151 at the top of the positive pressure body 150, and at least one first air hole group is distributed on the first conveyor belt 110. The first air hole group includes multiple first air holes arranged along a first straight line, and the multiple first air holes on the first straight line are equally spaced. The air outlet 151 is located directly below the first straight line, and the air outlet end of the air outlet 151 faces the first conveyor belt 110. With this arrangement, during the conveying process of the first conveyor belt 110, the multiple first air holes in the first air hole group will pass through the air outlet end of the air outlet 151 in sequence, thereby achieving the effect of blowing air into the first air holes to generate positive pressure.

[0053] Furthermore, such as Figure 5 As shown, in addition to the air outlet holes 151 on the positive pressure body 150, this embodiment also provides an air guide plate 160 on the top of the positive pressure body 150. The air guide plate 160 is fixed to the top surface of the positive pressure body 150. When the positive pressure body 150 is installed below the first conveyor belt 110, the air guide plate 160 is located between the positive pressure body 150 and the first conveyor belt 110. The positive pressure body 150 and the air guide plate 160 can be fixed by welding or bonding, etc. The top surface of the air guide plate 160 is flat so that the air guide plate 160 can fit against the first conveyor belt 110, reducing the gap between the air guide plate 160 and the first conveyor belt 110. The top surface of the air guide plate 160 is provided with an air guide groove 161. The length direction of the air guide groove 161 is parallel to the conveying direction of the first conveyor belt 110, that is, the length direction of the air guide groove 161 is parallel to the first straight line. Each air guide groove 161 has its bottom connected to at least one air outlet hole 151 located on the top of the positive pressure body 150. The length of the air guide groove 161 is greater than the diameter of the air outlet hole 151, and along the conveying direction of the first conveyor belt 110, the length of the air guide groove 161 is greater than the distance between two adjacent first air holes. This arrangement allows the gas blown out of the positive pressure body 150 from the air outlet hole 151 to enter the air guide groove 161 and then be dispersed throughout the entire air guide groove 161. When the first conveyor belt 110 moves, the first air holes on the first conveyor belt 110 also move synchronously. In this process, at least one air hole on the first conveyor belt 110 is always connected to the air guide groove 161, that is, at least one air hole is connected to the air outlet hole 151. This ensures that the blowing force of the positive pressure body 150 on the flexible sheet is not interrupted.

[0054] Preferably, along the surface of the first conveyor belt 110, there are multiple sets of the first air holes, and these multiple sets of the first air holes are spaced apart along a second straight line, which is parallel to the direction perpendicular to the conveying direction of the first conveyor belt 110. Correspondingly, a plurality of air outlet holes 151 are provided on the top of the positive pressure body 150, and these multiple air outlet holes 151 are spaced apart along the second straight line, so that each air outlet hole 151 corresponds to a set of the first air holes.

[0055] Furthermore, there are multiple air guide grooves 161, which are arranged at intervals along the second straight line, and each interval air guide groove 161 corresponds to a group of air holes.

[0056] To facilitate the installation of the air guide plate 160 onto the positive pressure body 150, the air guide plate 160 provided in this embodiment has a first bending portion and a second bending portion formed by downward bending on both sides, respectively. The first bending portion and the second bending portion are arranged along the conveying direction of the conveyor belt. Both the first bending portion and the second bending portion bend in the same direction, and the distance between the first bending portion and the second bending portion is equal to the length of the positive pressure body 150 along the conveying direction of the first conveyor belt 110. When it is necessary to install the air guide plate 160 onto the positive pressure body 150, the first bending portion and the second bending portion limit the position of the air guide plate 160, so that the air guide plate 160 is limited to the positive pressure body 150 by the first bending portion and the second bending portion.

[0057] By setting the first bend and the second bend, the air guide plate 160 can be pre-fixed to the positive pressure body 150, making it easier to fix the air guide plate 160 to the positive pressure body 150 by bolt connection or welding.

[0058] It should be noted that the structures of the first negative pressure body 130 and the second negative pressure body 230 can also adopt the same structure as the positive pressure body 150.

[0059] Furthermore, when the distance between the positive pressure body 150 and the first conveyor belt 110 increases, the positive pressure blowing force exerted by the positive pressure body 150 on the first air hole of the first conveyor belt 110 will inevitably decrease sharply. Therefore, the adjustment distance of the positive pressure body 150 is limited while ensuring that at least the required positive pressure blowing force is provided to the first air hole. In view of this, in this embodiment, a second adjustment mechanism for adjusting the height of the second conveying mechanism 200 is provided on the frame 300, and the second conveying mechanism 200 is fixed to the second adjustment mechanism. By adjusting the overall height of the second conveying mechanism 200 through the second adjustment mechanism, the distance between the second conveyor belt 210 and the first conveyor belt 110 can be adjusted. This reduces the magnitude of the negative pressure suction force required by the second negative pressure body 230 and also reduces the magnitude of the positive pressure blowing force of the positive pressure body 150.

[0060] Specifically, such as Figure 4As shown, the second conveying mechanism 200 includes a second support 250, a second conveyor belt 210, and a second drive mechanism 220, all of which are fixed on the second support 250. The first adjustment mechanism includes at least four adjustment components 260, which are symmetrically arranged on both sides of the second support 250. Each adjustment component 260 includes an adjustment bolt 261 and a pad 262. The adjustment bolt 261 passes through the second support 250, and the threaded end of the adjustment bolt 261 is threadedly connected to the frame. The pad 262 is detachably placed between the second support 250 and the frame. The pad 262 comes in various thicknesses. Different thicknesses of pad 262 are selected based on the thickness of the flexible sheet material. After the pad 262 is placed between the second support 250 and the frame, the adjusting bolt 261 is tightened to clamp the pad 262 between the second support 250 and the frame, thereby adjusting the overall height of the second conveying mechanism 200. The pad 262 can support the overall weight of the second conveying mechanism 200, improving the service life of the conveying device. Of course, in some optional embodiments, other components can be used for the second adjustment mechanism to achieve the overall height adjustment of the second conveying mechanism 200, such as a shear lifting assembly or a telescopic cylinder assembly.

[0061] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

Claims

1. A conveying device for conveying flexible sheets, characterized in that, include: A first conveying mechanism (100) has a first conveyor belt (110) with a plurality of first air holes (111) distributed on the first conveyor belt (110) and a first negative pressure body (130) fixed below the first conveyor belt (110). A second conveying mechanism (200) has a second conveyor belt (210) with a plurality of second air holes (211) distributed on it. A portion of the second conveyor belt (210) is located above the first conveyor belt (110), and a second negative pressure body (230) is fixed above the second conveyor belt (210). A positive pressure body (150) is fixed below the first conveyor belt (110). At least a portion of the positive pressure body (150) is located directly below the second conveyor belt (210). Along the conveying direction of the flexible sheet, the first negative pressure body (130), the positive pressure body (150), and the second negative pressure body (230) are arranged in sequence. The first negative pressure body (130), the positive pressure body (150), and the second negative pressure body (230) can act on the same flexible sheet simultaneously. At least a portion of the positive pressure body (150) is located directly below the second negative pressure body (230).

2. The conveying device according to claim 1, characterized in that, The distance between the positive pressure body (150) and the first conveyor belt (110) is adjustable.

3. A conveying device according to claim 2, characterized in that, The positive pressure body (150) supports the first conveyor belt (110).

4. A conveying device according to claim 1, characterized in that, At least one group of first air holes (111) is distributed on the first conveyor belt (110). The group of first air holes (111) includes a plurality of first air holes (111) that are uniformly and spaced apart along a first straight line. The first straight line is parallel to the conveying direction of the first conveyor belt (110). An air outlet hole (151) is provided on the top of the positive pressure body (150). The air outlet hole (151) is located directly below the first straight line.

5. A conveying device according to claim 4, characterized in that, The top of the positive pressure body (150) is fixed with an air guide plate (160), and an air guide groove (161) is opened on the top surface of the air guide plate (160). The length direction of the air guide groove (161) is parallel to the first straight line. The air guide groove (161) is located directly below the first straight line. The length of the air guide groove (161) is greater than or equal to the distance between two adjacent air outlet holes (151) in the first straight line. The bottom of each air guide groove (161) is connected to at least one air outlet hole (151).

6. A conveying device according to claim 5, characterized in that, The bottom of each of the air guide grooves (161) is connected to an air outlet hole (151), which is located in the middle of the bottom of the air guide groove (161).

7. A conveying device according to claim 5, characterized in that, Along the conveying direction of the first conveyor belt (110), the air guide plate (160) is provided with a first bending part and a second bending part formed by bending downward on both sides, and the air guide plate (160) is limited to the positive pressure body (150) by the first bending part and the second bending part.

8. A conveying device according to claim 1, characterized in that, The conveying device (10) further includes an identification device (141). Along the conveying direction of the flexible sheet, the identification device (141) is disposed between the first negative pressure body (130) and the positive pressure body (150). The distance between the identification device (141) and the positive pressure body (150) is less than the length of the flexible sheet. When the identification device (141) identifies the flexible sheet, the positive pressure body (150) provides positive pressure gas to the first conveyor belt (110).

9. A surface defect detection device, characterized in that, The device includes a conveying device (10) according to any one of claims 1-8, a first camera (20) and a second camera (30), wherein the first camera (20) is located above the first conveyor belt (110) and facing the first negative pressure body (130), and the second camera (30) is located below the second conveyor belt (210) and facing the second negative pressure body (230).

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