A mold surface defect rapid detection device

Abstract

The utility model discloses a kind of mould surface defect rapid detection devices, including workbench, mould fixing mechanism, elastic clamping component, multi-camera vision system and protection mechanism.The linear slide of workbench is cooperated with servo motor drive ball screw, and mould fixing mechanism is accurately positioned;U type clamping groove both sides are set with movable clamping block with wedge-shaped guide surface, and controllable clamping is realized by adjusting screw and belleville spring;Multi-dimensional adjustment industrial camera is installed on three columns, and optical axis converges in mould center;Transparent protective cover is driven by cylinder to form closed detection chamber.The device is exposed by high-precision displacement synchronous camera, combined with multi-angle stereoscopic imaging, realizes mould surface defect rapid nondestructive testing, and detection efficiency is improved by 3 times, and clamping damage rate is less than 0.5%.

Description

Technical Field

[0001] This utility model relates to the field of mold appearance inspection, and in particular to a rapid detection device for mold surface defects. Background Technology

[0002] As a core forming tool in industrial manufacturing, the surface quality of molds directly determines product precision. Current mold inspection mainly relies on manual visual inspection combined with single-point measuring instruments, resulting in low inspection efficiency (especially for complex curved molds, full-size inspection can take 2-3 hours) and a high rate of missed defects such as microcracks / scratches. While automated inspection equipment based on machine vision has emerged, the following technical bottlenecks remain: 1. Insufficient motion positioning accuracy: Traditional lead screw drive systems, due to excessive lead (typically ≥10mm), accumulate positioning errors, failing to meet sub-pixel-level image stitching requirements (image registration failure rate increases by more than 40% when error >0.05mm); 2. Clamping damage risk: Rigid clamping mechanisms are prone to scratching the mold surface during rapid clamping (especially for mirror molds, the damage rate is as high as 8%), and clamping force control depends on operator experience; 3. Limited imaging quality: Single-camera multi-angle scanning requires frequent adjustments to the mold posture, leading to low inspection efficiency (single full-surface inspection takes >30 minutes), and ambient light interference reduces image contrast.

[0003] An existing patent (publication number: CN213398230U) discloses a machine vision-based product appearance inspection device. After the camera of this device takes a picture of the circuit board module, if the product is qualified, the hydraulic cylinder works to drive the carrier back to the first conveyor belt. If the product is defective, the second push rod works to push the carrier to the surface of the second conveyor belt and transport the carrier to the repair point. This allows the equipment to automatically classify good and bad products after inspection, eliminating redundant classification steps on the production line. However, this appearance inspection device can only inspect the product from above and cannot inspect the product from all directions, resulting in insufficient inspection and poor inspection effect. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a rapid detection device for surface defects of molds.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] This utility model discloses a rapid detection device for mold surface defects, comprising: a worktable with parallel linear slide rails and ball screws on its surface, the ball screws being connected to a servo motor; a mold fixing mechanism, including a fixed base body slidably connected to the linear slide rails at its bottom, the fixed base body having a U-shaped clamping groove extending along its length at its top; an elastic clamping assembly, including fixed positioning blocks and movable clamping blocks symmetrically arranged on both sides of the U-shaped clamping groove, the movable clamping blocks being driven to move by adjusting screws and slidingly engaging with the fixed base body; a multi-camera vision system, including three columns arranged around the mold fixing mechanism, each column having at least one industrial camera mounted on it via a multi-dimensional adjustment bracket, the optical axes of the industrial cameras converging at the central axis of the U-shaped clamping groove; a protective mechanism, including a liftable transparent protective cover and a linear cylinder driving its lifting and lowering, the transparent protective cover forming a sealed detection chamber with the worktable surface when lowered; and a control module configured to synchronously control the displacement of the servo motor and the exposure sequence of the industrial cameras.

[0007] As a preferred technical solution of this utility model, the lead of the ball screw is 5mm, the servo motor is equipped with a 17-bit absolute encoder, and the fixed base body and the linear slide rail are rigidly connected.

[0008] As a preferred technical solution of this utility model, the movable clamping block is provided with a wedge-shaped guide surface with an inclination angle of 15°±2°, and disc springs and guide rods are symmetrically arranged on both sides of the adjusting screw. The stiffness coefficient of the disc spring is 50N / mm, and the thread section of the adjusting screw is provided with a preload scale mark.

[0009] As a preferred technical solution of this utility model, the fixed positioning block is equipped with a pressure sensor with a range of 0-300N, and the clamping surface of the movable clamping block is provided with a polyurethane buffer pad with a Shore hardness of 80A±5A and a thickness of 3mm±0.2mm.

[0010] As a preferred embodiment of this utility model, the multi-dimensional adjustment bracket includes an X-axis translation slide and a Y-axis pitch adjustment seat. The sliding direction of the X-axis translation slide is parallel to the worktable surface and the stroke is ±30mm. The rotation axis of the Y-axis pitch adjustment seat is perpendicular to the X-axis sliding direction and the adjustment angle range is ±60°.

[0011] As a preferred technical solution of this utility model, the surface of the U-shaped clamping groove is treated with a diffuse reflection coating with a visible light band reflectivity ≤5%, the coating thickness is 20-80μm, and the surface roughness Ra=0.4-0.8μm.

[0012] As a preferred embodiment of this utility model, the number of industrial cameras is four, which are respectively installed on the top and middle of the three columns. The angles formed by the optical axes of the four industrial cameras and the central axis of the U-shaped clamping groove are 30°, 45° and 60° respectively.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] 1. High-precision motion control: The combination of a ball screw with a lead of 5mm and a servo motor with a 17-bit absolute encoder achieves a repeatability positioning accuracy of ±0.005mm. Combined with the displacement-exposure synchronization algorithm of the control module, the image acquisition position error is ≤0.01mm, which meets the requirements of high-precision image stitching.

[0015] 2. Non-destructive clamping guarantee: The elastic clamping mechanism, consisting of a wedge-shaped guide surface (15°±2°) and a disc spring (stiffness 50N / mm), converts the vertical clamping force into a controllable horizontal thrust. Combined with the preload scale markings, the clamping force adjustment accuracy reaches ±5N. The polyurethane buffer pad (Shore hardness 80A±5A) and the pressure sensor (0-300N range) form a dual protection mechanism. Actual tests show that the clamping damage rate of the mold surface can be kept below 0.5%.

[0016] 3. High-efficiency 3D imaging: The four cameras are arranged at 30° / 45° / 60° to cover the entire surface of the mold. Combined with the U-shaped groove diffuse reflection coating (reflectivity ≤5%), the interference of specular reflection is eliminated, which improves the defect recognition rate to 99.7%. The multi-camera synchronous triggering mechanism shortens the single inspection time to 8-10 minutes, which is more than 3 times more efficient than traditional methods. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is the front view of this utility model;

[0020] Figure 3 This is a top view of the present invention;

[0021] Figure 4 This is a side view of the present invention;

[0022] Figure 5 This is a schematic diagram of the mold fixing mechanism in this utility model;

[0023] Figure 6This is a schematic diagram of the structure of the multi-camera vision system in this utility model;

[0024] In the diagram: 1. Workbench; 3. Mold fixing mechanism; 4. Multi-camera vision system; 5. Protective mechanism; 6. Control module; 21. Linear slide rail; 22. Servo motor; 23. Ball screw; 31. Fixed base body; 32. Fixed positioning block; 33. Movable clamping block; 34. Adjusting screw; 35. Disc spring; 36. Guide rod; 41. Industrial camera; 42. Multi-dimensional adjustment bracket; 43. Column; 51. Transparent protective cover; 52. Linear cylinder; 311. U-shaped clamping groove; 321. Pressure sensor; 331. Wedge-shaped guide surface; 332. Polyurethane buffer pad; 421. X-axis translation slide; 422. Y-axis pitch adjustment base; 431. Laser rangefinder sensor. Detailed Implementation

[0025] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0026] In the attached diagram, all identical reference numerals refer to the same components.

[0027] like Figure 1-6 As shown, this utility model provides a rapid detection device for mold surface defects, including the following components: a worktable 1: the table surface is provided with two parallel linear slide rails 21 and a ball screw 23, the ball screw 23 being coaxially connected to the output shaft of a servo motor 22 via a coupling. The slider of the linear slide rail 21 is rigidly fixed to the bottom of the mold fixing mechanism 3 by bolts, and the servo motor 22 drives the ball screw 23 to rotate, causing the mold fixing mechanism 3 to reciprocate along the linear slide rails 21.

[0028] Mold fixing mechanism 3: The fixing base body 31 is a cuboid structure with a U-shaped clamping groove 311 extending along the length direction at the top for placing the mold to be tested.

[0029] Please see the appendix Figure 5 The elastic clamping assembly includes a fixed positioning block 32 and a movable clamping block 33 symmetrically arranged on both sides of the U-shaped clamping groove 311. The bottom of the movable clamping block 33 is provided with a wedge-shaped guide surface, which slides in cooperation with the inclined surface of the side wall of the fixed base body 31. An adjusting screw 34 passes horizontally through the side wall of the fixed base body 31, and its front end is connected to the movable clamping block 33 by a thread. Rotating the adjusting screw 34 can drive the movable clamping block 33 to move along the wedge-shaped guide surface, thereby clamping or releasing the mold.

[0030] Two sets of disc springs 35 and guide rods 36 are symmetrically arranged on both sides of the adjusting screw 34. The disc springs 35 are sleeved on the outside of the guide rods 36 to buffer the impact force during the clamping process.

[0031] Please see the appendix Figure 6 The multi-camera vision system 4 consists of three columns 43 arranged in an equilateral triangle around the mold fixing mechanism 3. A multi-dimensional adjustment bracket 42 is bolted to the side of each column 43. The multi-dimensional adjustment bracket 42 includes an X-axis translation slide and a Y-axis pitch adjustment seat. Industrial cameras 41 are mounted at the end of the adjustment bracket via quick-release clamps. The optical axes of the four industrial cameras 41 converge at the central axis of the U-shaped clamping groove 311, enabling simultaneous acquisition of mold surface images from different angles. Laser range sensors 431 are embedded in the sides of the columns 43, with the measurement reference plane pointing towards the central axis of the U-shaped clamping groove 311.

[0032] Protective Mechanism 5: The transparent protective cover 51 has a cubic frame structure, and its top is hinged to the support of the workbench 1 via a linear cylinder 52. The piston rod of the linear cylinder 52 extends and retracts to drive the transparent protective cover 51 to rise and fall vertically. When it descends, the bottom edge of the transparent protective cover 51 fits tightly against the surface of the workbench 1 to form a closed detection space.

[0033] The control module 6 is integrated into the electrical box on top of the transparent protective cover 51, and is electrically connected to the servo motor 22, the industrial camera 41, and the linear cylinder 52 via cables. The pulse signal of the servo motor 22 and the exposure signal of the industrial camera 41 are synchronously triggered by an internal timer to ensure that the image is acquired immediately when the mold moves to the preset position.

[0034] The method of using this utility model is as follows:

[0035] 1. Servo motor 22 drives ball screw 23 to rotate, converting the rotational motion into linear displacement of mold fixing mechanism 3, thereby achieving precise positioning of the mold;

[0036] 2. The adjusting screw 34 pushes the movable clamping block 33 to slide along the wedge-shaped guide surface through the threaded transmission. In conjunction with the elastic deformation of the disc spring 35, the rotation adjustment amount is converted into a stable clamping force to avoid damage to the mold surface.

[0037] 3. The X / Y mechanical adjustment mechanism of the multi-dimensional adjustment bracket 42 enables the optical axis angle of the industrial camera 41 to be precisely adapted to the imaging requirements of molds of different sizes.

[0038] Furthermore, the transparent protective cover 51 isolates external environmental interference during the testing process, and the rapid lifting function of the linear cylinder 52 facilitates mold loading and unloading operations.

[0039] Furthermore, the control module 6 controls the stepping displacement of the servo motor 22 and the exposure timing of the industrial camera 41 through a synchronization signal to ensure the clarity and positional consistency of image acquisition during the movement.

[0040] This utility model is a rapid detection device for surface defects of molds. Through modular design, it achieves the synergistic effects of high-precision positioning, non-destructive clamping, multi-angle imaging and environmental protection, and is suitable for the rapid full inspection needs of complex curved surface molds.

[0041] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A rapid detection device for surface defects in molds, characterized in that, include: A workbench (1) has parallel linear guide rails (21) and a ball screw (23) driven by a servo motor (22) on its surface; a mold fixing mechanism (3) includes a fixed base body (31) slidably connected to the linear guide rails (21) at its bottom, and a U-shaped clamping groove (311) is provided on the top of the fixed base body (31); an elastic clamping assembly includes a fixed positioning block (32) and a movable clamping block (33) symmetrically arranged on both sides of the U-shaped clamping groove (311), and the movable clamping block (33) is driven by an adjusting screw (34) to achieve linear displacement; a multi-camera vision system (4) includes a system surrounding the mold fixing mechanism (3). At least three columns (43) are arranged, and an industrial camera (41) is installed on each column (43) via a multi-dimensional adjustment bracket (42). The optical axes of each industrial camera (41) converge at the central axis of the U-shaped clamping groove (311). The protective mechanism (5) includes a transparent protective cover (51) surrounding the mold fixing mechanism (3) and a linear cylinder (52) that drives the transparent protective cover (51) to rise and fall. When the transparent protective cover (51) falls, it forms a sealed detection chamber with the workbench (1) surface. The control module (6) is configured to synchronously trigger the displacement movement of the servo motor (22) and the image acquisition action of the industrial camera (41).

2. The rapid detection device for mold surface defects according to claim 1, characterized in that, The ball screw (23) has a lead of 5mm, the servo motor (22) is equipped with a 17-bit high-precision absolute encoder, and the bottom of the fixed base body (31) is fixedly connected to the slider of the linear slide rail (21) by bolts.

3. The rapid detection device for mold surface defects according to claim 1, characterized in that, The movable clamping block (33) is provided with a wedge-shaped guide surface (331) of 15°±2°. The adjusting screw (34) is provided with disc springs (35) and guide rods (36) on both sides. The stiffness coefficient of the disc springs (35) is 50N / mm. The adjusting screw (34) is provided with a preload scale mark.

4. The rapid detection device for mold surface defects according to claim 3, characterized in that, The fixed positioning block (32) is equipped with a pressure sensor (321) with a detection range of 0-300N and a linear error of ≤±1N; the clamping surface of the movable clamping block (33) is bonded with a polyurethane buffer pad (332), the polyurethane buffer pad (332) has a Shore hardness of 80A±5A and a thickness of 3mm±0.2mm.

5. The rapid detection device for mold surface defects according to claim 1, characterized in that, The multidimensional adjustment bracket (42) includes: an X-axis translation slide (421) whose sliding direction is parallel to the worktable (1) surface and has a stroke of ±30mm; a Y-axis pitch adjustment seat (422) whose rotation axis is perpendicular to the sliding direction of the X-axis translation slide (421) and has an adjustment angle range of ±60°; and a laser range sensor (431) is embedded on the side of the column (43) with the measurement reference plane pointing to the central axis of the U-shaped clamping groove (311).

6. The rapid detection device for mold surface defects according to claim 1, characterized in that, The surface treatment of the U-shaped clamping groove (311) is a diffuse reflection coating with a reflectivity of ≤5% in the visible light band, a coating thickness of 20-80μm, and a surface roughness Ra=0.4-0.8μm.

7. The rapid detection device for mold surface defects according to claim 1, characterized in that, The number of industrial cameras (41) is four, which are installed on the top and middle of the three columns (43). The angles formed by the optical axes of the four industrial cameras (41) and the central axis of the U-shaped clamping groove (311) are 30°, 45° and 60° respectively, forming a three-dimensional imaging optical path.

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