Battery bracket die casting detection method and system

Abstract

The invention discloses a battery bracket die casting detection method and system, relates to the field of die casting detection, and solves the problem of erroneous judgment in battery bracket die casting anomaly detection. The method comprises the following steps: acquiring outer surface images of a battery bracket die casting at multiple visual angles; detecting the size of the battery bracket die casting to obtain a size abnormal signal or a size normal signal of the battery bracket die casting; appearance detection is conducted on the battery bracket die casting, if air holes or cracks exist, an appearance abnormal signal is generated, and if air holes or cracks do not exist, an appearance normal signal is generated; carrying out mechanical property detection on the battery bracket die castings, and obtaining the mechanical abnormal rate of the battery bracket die castings of the corresponding batch according to a detection result; the abnormal conditions of the battery bracket die castings of the corresponding batch are known according to the detection results of the different stages, and the abnormal conditions corresponding to the battery bracket die castings of the same batch are accurately recognized by detecting the battery bracket die castings of the different stages.

Description

Technical Field

[0001] The present invention belongs to the technical field of die-casting part detection, and specifically relates to a detection method and system for die-cast parts of a battery bracket. Background Art

[0002] The battery bracket, also known as the battery box, battery case, battery bracket, and lower battery box, is an important part of the power system of new energy vehicles and an important guarantee for the safety of the battery system. Since it needs to have high strength and large specifications to carry and balance the weight and safety of the battery, the battery bracket often has properties such as high precision, corrosion resistance, high temperature resistance, impact resistance, and good heat conduction; a battery bracket with high strength can better ensure the safety of the battery pack. Therefore, the detection method of the battery bracket can ensure that it meets the requirements of structural strength and durability. However, at the present stage, the detection of die-cast parts of the battery bracket highly relies on manual labor, with low automation and it is difficult to meet the on-line detection requirements of large-scale production lines. At the same time, there are inconsistent judgment criteria among different detection personnel in manual detection, which leads to a relatively low detection accuracy. Therefore, the present invention proposes a detection method and system for die-cast parts of a battery bracket. Summary of the Invention

[0003] The purpose of the present invention is to propose a detection method and system for die-cast parts of a battery bracket to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions: In the first aspect, a detection method for die-cast parts of a battery bracket, the method includes: Step S1, collecting external surface images of the die-cast part of the battery bracket from multiple perspectives; Step S2, performing dimensional detection on the die-cast part of the battery bracket to obtain a dimensional abnormal signal or a dimensional normal signal of the die-cast part of the battery bracket; Step S3, performing appearance detection on the die-cast part of the battery bracket. If there are pores or cracks, an appearance abnormal signal is generated. If there are no pores and cracks, an appearance normal signal is generated; Step S4, performing mechanical property detection on the die-cast part of the battery bracket, and obtaining the mechanical abnormality rate of the die-cast parts of the corresponding batch of battery brackets according to the detection results; Step S5, obtaining the abnormal situation of the die-cast parts of the corresponding batch of battery brackets according to the detection results at different stages.

[0005] Further, the step S2 includes the following sub-steps: Step S21, obtaining external surface images of the die-cast part of the battery bracket from multiple perspectives, and splicing the external surface images from multiple perspectives to obtain a spliced appearance image of the die-cast part of the battery bracket; Step S22: Establish a working coordinate system. Take the center point of the bottom surface of the spliced appearance image as the origin. Draw a straight line perpendicular to the bottom surface at the origin and denote it as the Z-axis. Draw two intersecting lines with the foot of the perpendicular at the origin in the bottom surface, and denote them as the X-axis and the Y-axis respectively. Step S23: Read the corresponding installation hole positions of the battery carrier die-casting according to the spliced appearance image. Take the center coordinates of the installation hole positions as the hole position coordinates of the installation hole positions. Then obtain the design drawing of the battery carrier die-casting, and read the corresponding preset hole position coordinates and preset hole diameters of the battery carrier die-casting according to the design drawing.

[0006] Furthermore, step S2 further includes the following sub-steps: Step S24: Compare the hole position coordinates of the battery carrier die-casting with the corresponding preset hole position coordinates. If there is any hole position coordinate of an installation hole that is different from the corresponding preset hole position coordinate, generate a dimension abnormal signal; if the hole position coordinates of all installation hole positions are the same as the corresponding preset hole position coordinates, proceed to the subsequent steps. Step S25: Measure the hole diameters of the corresponding installation hole positions in combination with the hole position coordinates of the installation hole positions; compare the hole diameters with the corresponding preset hole diameters. If the hole diameter of any installation hole position is different from the corresponding preset hole diameter, generate a dimension abnormal signal; if the hole diameters of all installation hole positions are the same as the corresponding preset hole diameters, execute the subsequent steps. Step S26: Regard the spliced appearance image of the battery carrier die-casting as a cube, measure the length, width, and height of the cube, and then obtain the bottom surface area of the corresponding bottom surface of the cube and the side surface areas of the four groups of side surfaces.

[0007] Furthermore, step S2 further includes the following sub-steps: Step S27: Obtain the number of measurement points according to the bottom surface area and the side surface areas, mark the corresponding number of measurement points at any position on the bottom surface and the side surfaces, and record the coordinates of the measurement points; measure the distance between adjacent measurement points in the same plane and denote it as the plane dimension distance, and then obtain a plurality of plane dimension distances corresponding to the bottom surface and the four side surfaces. Step S28: Mark the same number of measurement points at the same position in the design drawing, and then obtain the standard plane dimension distance corresponding to the plane dimension distance; calculate the absolute value of the difference between the plane dimension distance and the standard plane dimension distance and denote it as the plane distance difference value. Step S29: Compare the multiple groups of plane distance difference values with the plane distance difference threshold. If any group of plane distance difference values is greater than or equal to the plane distance difference threshold, generate a dimension abnormal signal; if all plane distance difference values are less than the plane distance difference threshold, generate a dimension normal signal.

[0008] Furthermore, step S4 includes the following sub-steps: Step S41, select a fixed number of battery bracket die-castings from the same batch of battery bracket die-castings as mechanical sample die-castings, divide the mechanical sample die-castings into two parts evenly, and use them for mechanical tensile testing and mechanical hardness testing in sequence; Step S42, perform mechanical tensile testing to obtain the number of tensile anomalies corresponding to the mechanical sample die-castings under the mechanical tensile testing; Step S43, perform mechanical hardness testing to obtain the number of hardness anomalies corresponding to the mechanical sample die-castings under the hardness testing; Step S44, add the number of hardness anomalies and the number of tensile anomalies to obtain the number of mechanical anomalies; divide the number of mechanical anomalies by the total number of mechanical sample die-castings to obtain the mechanical anomaly rate of the corresponding batch of battery bracket die-castings.

[0009] Furthermore, the specific process of the mechanical tensile testing is as follows: Step S421, select any one of the mechanical sample die-castings, clamp the mechanical sample die-casting in the fixture of a universal tensile testing machine, select two marking points on the mechanical sample die-casting, and record the distance between the marking points as the original gauge length; set the tensile rate of the mechanical tensile testing; Step S422, adjust the tensile load and record the load-displacement curve corresponding to the mechanical sample die-casting until the mechanical sample die-casting is torn; measure the distance between the two marking points again and record it as the gauge length after fracture; Step S423, read the maximum load from the load-displacement curve, and calculate the tensile strength of the mechanical sample die-casting based on the maximum load. The calculation formula is: Tensile strength = Maximum load / Sample cross-sectional area.

[0010] Furthermore, the detection process of the mechanical tensile testing also includes: Step S424, draw a straight line parallel to the linear stage in the load-displacement curve with an offset of 0.2% strain, record the intersection point of the straight line and the load-displacement curve as the yield point, read the yield load of the yield point, and divide the yield load by the sample cross-sectional area to obtain the yield strength of the mechanical sample die-casting; Step S425, calculate the elongation of the mechanical sample die-casting through the formula. The specific formula is as follows: Elongation = (Gauge length after fracture - Original gauge length) / Original gauge length × 100%; Step S426, compare the tensile strength, yield strength, and elongation of the mechanical sample die-casting with the corresponding thresholds in sequence; if any one of the tensile strength, yield strength, and elongation of the mechanical sample die-casting is less than the corresponding threshold, mark the mechanical sample die-casting as a tensile anomaly die-casting; if the tensile strength, yield strength, and elongation of the mechanical sample die-casting are all greater than the corresponding thresholds, mark the mechanical sample die-casting as a mechanically qualified die-casting; Step S427: Perform mechanical tensile tests on all mechanical sample die-castings, and count the number of die-castings with abnormal tensile results, which is recorded as the tensile abnormality number.

[0011] Further, the specific process of the mechanical hardness test is as follows: Step S431: Randomly select a mechanical sample die-casting, and evenly select multiple hardness test points on the surface of the mechanical sample die-casting. Step S432: Read the corresponding required hardness range according to the design drawing of the mechanical sample die-casting, and select the indenter and indenter load ZH for hardness testing according to the required hardness range, the material type and thickness of the mechanical sample die-casting. Step S433: Apply a force equal to the indenter load on the hardness test point through the indenter for a continuous holding time, and record the indentation depth and indentation diameter. Step S434: Compare the indentation depth with the sample thickness of the mechanical sample die-casting. If the sample thickness of the mechanical sample die-casting is less than eight times the indentation depth, replace the indenter; if the sample thickness of the mechanical sample die-casting is greater than or equal to eight times the indentation depth, proceed to the next step.

[0012] Further, the detection process of the mechanical hardness test also includes: Step S435: Calculate the calculated hardness value JY of the mechanical sample die-casting through a formula. The specific calculation formula is as follows: ; where π is the pi, D is the indenter diameter, and d is the indentation diameter. Step S436: Compare the calculated hardness value of the mechanical sample die-casting with the required hardness range. If the calculated hardness value of any one hardness test point is outside the required hardness range, mark the corresponding mechanical sample die-casting as a hardness-abnormal die-casting; if the calculated hardness values of all hardness test points are within the required hardness range, mark the corresponding mechanical sample die-casting as a hardness-qualified die-casting. Step S437: Perform hardness tests on all mechanical sample die-castings, and record the number of hardness-abnormal die-castings, which is recorded as the hardness abnormality number.

[0013] In a second aspect, a detection system for battery bracket die-castings includes a database, a data acquisition module, a dimension detection module, an appearance detection module, a mechanical property detection module, and a user terminal. The data acquisition module is used to collect the outer surface images of the battery bracket die-casting from multiple perspectives and send them to the dimension detection module and the appearance detection module. The database is used to store the design drawings of the battery bracket die-castings and send the design drawings to the dimension detection module and the mechanical property detection module. The dimension detection module is used to detect the dimensions of the die-cast battery bracket, obtain a dimension anomaly signal or a dimension normal signal of the die-cast battery bracket, and send it to the user terminal; The appearance detection module is used to detect the appearance of the die-cast battery bracket. If there are air holes or cracks, an appearance anomaly signal is generated. If there are no air holes and cracks, an appearance normal signal is generated. The appearance detection module sends the appearance anomaly signal or the appearance normal signal to the user terminal; The mechanical property detection module is used to detect the mechanical properties of the die-cast battery bracket, obtain the mechanical anomaly rate of the die-cast battery bracket in the corresponding batch according to the detection results, and send it to the user terminal; The user terminal is used to receive the detection results at different stages. The user reads the user terminal to know the anomaly situation of the die-cast battery bracket in the corresponding batch.

[0014] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows: 1. The present invention first collects the outer surface images of the die-cast battery bracket from multiple perspectives; then detects the dimensions of the die-cast battery bracket to obtain a dimension anomaly signal or a dimension normal signal of the die-cast battery bracket; at the same time, detects the appearance of the die-cast battery bracket. If there are air holes or cracks, an appearance anomaly signal is generated. If there are no air holes and cracks, an appearance normal signal is generated. The present invention realizes the detection of the dimensions and appearance of the die-cast battery bracket; 2. The present invention further detects the mechanical properties of the die-cast battery bracket, obtains the mechanical anomaly rate of the die-cast battery bracket in the corresponding batch according to the detection results; finally, knows the anomaly situation of the die-cast battery bracket in the corresponding batch according to the detection results at different stages. The present invention realizes the accurate identification of the anomaly situation of the die-cast battery bracket by detecting the die-cast battery bracket at different stages. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings.

[0016] Figure 1 It is the method flow block diagram of the method in the present invention; Figure 2 It is the structural schematic diagram of the die-cast battery bracket in the present invention; Figure 3 It is the schematic diagram of the load-displacement curve in the present invention; Figure 4 It is the system block diagram in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0018] Example 1. Refer to Figures 1-3 As shown, the technical solution provided by the present invention is: a detection method for battery bracket die-castings. This method sequentially detects the dimensions, appearance, and mechanical properties of the battery bracket die-castings to accurately obtain the abnormal conditions corresponding to an entire batch of battery bracket die-castings. As Figure 2 shown, the battery bracket die-casting can be regarded as composed of a bottom surface and four side surfaces. In this embodiment, the detection method for the battery bracket die-castings includes: Step S1, collect the outer surface images of the battery bracket die-castings from multiple perspectives. Step S2, perform dimensional inspection on the battery bracket die-castings to obtain a dimensional abnormal signal or a dimensional normal signal of the battery bracket die-castings. In this embodiment, step S2 includes the following sub-steps: Step S21, obtain the outer surface images of the battery bracket die-castings from multiple perspectives, and splice the outer surface images from multiple perspectives to obtain the spliced appearance image of the battery bracket die-castings. Step S22, establish a working coordinate system. Take the center point of the bottom surface of the spliced appearance image as the origin, draw a straight line perpendicular to the bottom surface at the origin and denote it as the Z-axis, and draw two intersecting lines with the foot of the perpendicular at the origin in the bottom surface, and denote them as the X-axis and the Y-axis respectively. Step S23, read the corresponding mounting hole positions of the battery bracket die-castings according to the spliced appearance image, take the center coordinates of the mounting hole positions as the hole positions coordinates of the mounting hole positions, and then obtain the design drawing of the battery bracket die-castings, and read the corresponding preset hole positions coordinates and preset hole positions diameters of the battery bracket die-castings according to the design drawing. It should be noted that the mounting hole positions are the holes pre-designed and processed on the battery bracket die-castings, which are used to fix components at designated positions through fasteners such as bolts, screws, and rivets; the design drawing details various specification data such as the corresponding dimensions and materials of the battery bracket die-castings. Step S24, compare the hole positions coordinates of the battery bracket die-castings with the corresponding preset hole positions coordinates. If there is any hole positions coordinate of a mounting hole position different from the corresponding preset hole positions coordinate, generate a dimensional abnormal signal; if the hole positions coordinates of all mounting hole positions are the same as the corresponding preset hole positions coordinates, proceed to the subsequent steps. Step S25, measure the hole diameter of the corresponding mounting hole in combination with the hole position coordinates of the mounting hole; compare the hole diameter with the corresponding preset hole diameter. If the hole diameter of any one mounting hole is different from the corresponding preset hole diameter, generate a size anomaly signal; if the hole diameters of all mounting holes are the same as the corresponding preset hole diameters, proceed to the subsequent steps; Step S26, regard the splicing appearance image of the battery bracket die-casting as a cube, measure the length, width and height of the cube, and then obtain the bottom area of the corresponding bottom surface of the cube and the side areas of the four groups of side surfaces; Step S27, obtain the number of measurement points based on the bottom area and the side area, mark the corresponding number of measurement points at any position on the bottom surface and the side surfaces, and record the coordinates of the measurement points; measure the distance between adjacent measurement points in the same plane and record it as the plane size distance, and then obtain multiple plane size distances corresponding to the bottom surface and the four side surfaces; Step S28, mark the same number of measurement points at the same position in the design drawing, and then obtain the standard plane size distance corresponding to the plane size distance; calculate the absolute value of the difference between the plane size distance and the standard plane size distance and record it as the plane distance difference value; Step S29, compare multiple groups of plane distance difference values with the plane distance difference threshold. If any group of plane distance difference values is greater than or equal to the plane distance difference threshold, generate a size anomaly signal; if all plane distance difference values are less than the plane distance difference threshold, generate a size normal signal.

[0019] Step S3, perform an appearance inspection on the battery bracket die-casting. If there are air holes or cracks, generate an appearance anomaly signal; if there are no air holes and cracks, generate an appearance normal signal; It should be noted that the appearance inspection is directly obtained by using the YOLOv5 defect classification model to identify the splicing appearance image; YOLO is an object detection system for computer vision tasks, which has the characteristics of fast detection speed and high detection accuracy. The specific detection process will not be elaborated in this invention.

[0020] Step S4, perform a mechanical property inspection on the battery bracket die-casting, and obtain the mechanical anomaly rate of the corresponding batch of battery bracket die-castings according to the inspection results; In this embodiment, the step S4 includes the following sub-steps: Step S41, select a fixed number of battery bracket die-castings from the same batch of battery bracket die-castings as mechanical sample die-castings, divide the mechanical sample die-castings into two parts, and use them for mechanical tensile testing and mechanical hardness testing in turn; Step S42, perform a mechanical tensile test to obtain the number of tensile anomalies corresponding to the mechanical sample die-castings under the mechanical tensile test; In this embodiment, the detection process of the mechanical tensile test is as follows: Step S421: Select any die-cast part of the mechanical sample, clamp the die-cast part of the mechanical sample in the fixture of the universal tensile testing machine, select two marking points on the die-cast part of the mechanical sample, and record the distance between the marking points as the original gauge length; set the tensile rate of the mechanical tensile test; among them, the tensile rate is preferably 2 mm / min; It should be noted that the marking points should be located between the two fixtures. When performing the mechanical tensile test, a tensile test needs to be performed on each of the four sides and one bottom surface of the die-cast part of the battery bracket; Step S422, as Figure 3 shown, adjust the tensile load and record the load-displacement curve corresponding to the die-cast part of the mechanical sample until the die-cast part of the mechanical sample is torn; measure the distance between the two marking points again and record it as the gauge length after fracture; It should be additionally noted that if the fracture location is between the two marking points, measure the distances between the fracture location and the corresponding marking points respectively, and add the two distances together to obtain the gauge length after fracture; Step S423: Read the maximum load from the load-displacement curve, and calculate the tensile strength of the die-cast part of the mechanical sample based on the maximum load. The calculation formula is: Tensile strength = Maximum load / Sample cross-sectional area; among them, the sample cross-sectional area is read from the design drawing; Step S424: Draw a straight line parallel to the linear stage in the load-displacement curve with an offset of 0.2% strain, record the intersection point of the straight line and the load-displacement curve as the yield point, read the yield load of the yield point, and obtain the yield strength of the die-cast part of the mechanical sample by dividing the yield load by the sample cross-sectional area; Step S425: Calculate the elongation of the die-cast part of the mechanical sample through the formula. The specific formula is as follows: Elongation = (Gauge length after fracture - Original gauge length) / Original gauge length × 100%; Step S426: Compare the tensile strength, yield strength, and elongation of the die-cast part of the mechanical sample with the corresponding thresholds in turn; if any one of the tensile strength, yield strength, and elongation of the die-cast part of the mechanical sample is less than the corresponding threshold, mark the die-cast part of the mechanical sample as a die-cast part with abnormal tensile properties; if the tensile strength, yield strength, and elongation of the die-cast part of the mechanical sample are all greater than the corresponding thresholds, mark the die-cast part of the mechanical sample as a mechanically qualified die-cast part; Step S427: Perform the mechanical tensile test on all die-cast parts of the mechanical sample, and count the number of die-cast parts with abnormal tensile properties and record it as the number of abnormal tensile parts; For example, as specified in GB / T15115 "Die Cast Aluminum Alloys", the tensile strength of AlSi 12 Cu1(Fe) alloy needs to be greater than or equal to 200 MPa; AlSi12 The yield strength of the Cu1(Fe) alloy should be greater than or equal to 150 MPa; AlSi 12 The elongation rate of the Cu1(Fe) alloy should be greater than or equal to 1.0%; Step S43, perform mechanical hardness testing to obtain the number of hardness anomalies corresponding to the mechanical sample die-castings under the hardness test; In this embodiment, the specific process of the hardness test is as follows: Step S431, randomly select a mechanical sample die-casting, and uniformly select multiple hardness test points on the surface of the mechanical sample die-casting; preferably five; Step S432, read the corresponding required hardness range according to the design drawing corresponding to the mechanical sample die-casting, and select the indenter and indenter load ZH for the hardness test according to the required hardness range, the material type and thickness of the mechanical sample die-casting; Among them, the indenter is the tool that directly contacts the material in the hardness test; the load is the applied force, which needs to match the indenter diameter to ensure the standardization of the test. When specifically selecting, it is read according to the professional manual. For example, GB / T 231.1 "Metallic materials - Brinell hardness test - Part 1: Test method" stipulates the selection of test force and indenter for different material types and hardness ranges; Step S433, apply a force equal to the indenter load on the hardness test point through the indenter for a holding time, and record the indentation depth and indentation diameter; among them, the holding time is usually 15 - 30 seconds; Step S434, compare the indentation depth with the sample thickness of the mechanical sample die-casting. If the sample thickness of the mechanical sample die-casting is less than eight times the indentation depth, replace the indenter; if the sample thickness of the mechanical sample die-casting is greater than or equal to eight times the indentation depth, proceed to the subsequent steps; Step S435, calculate the calculated hardness value JY of the mechanical sample die-casting through the formula. The specific calculation formula is as follows: ; where π is the pi, D is the indenter diameter, and d is the indentation diameter; Step S436, compare the calculated hardness value of the mechanical sample die-casting with the required hardness range. If the calculated hardness value of any hardness test point is outside the required hardness range, record the corresponding mechanical sample die-casting as a hardness abnormal die-casting; if the calculated hardness values of all hardness test points are within the required hardness range, record the corresponding mechanical sample die-casting as a hardness qualified die-casting; Step S437, perform hardness testing on all mechanical sample die-castings, and record the number of hardness abnormal die-castings as the number of hardness anomalies; Step S44, add the number of hardness anomalies to the number of tensile anomalies to obtain the number of mechanical anomalies; divide the number of mechanical anomalies by the total number of mechanical sample die-castings to obtain the mechanical anomaly rate of the corresponding batch of battery bracket die-castings.

[0021] Step S5. Based on the detection results at different stages, the abnormal conditions of the die-castings of the battery bracket corresponding to the batches are obtained.

[0022] In this application, if there are corresponding calculation formulas, the above calculation formulas are all dimensionless and take their numerical values for calculation. For coefficients such as weight coefficients and proportionality coefficients in the formulas, the magnitudes set are for obtaining a result value by quantifying each parameter. Regarding the magnitudes of the weight coefficients and proportionality coefficients, as long as the proportional relationship between the parameters and the result value is not affected.

[0023] Embodiment 2. Please refer to Figure 4 As shown, based on another concept of the same invention, a detection system for die-castings of a battery bracket is proposed, including a database, a data acquisition module, a dimension detection module, an appearance detection module, a mechanical property detection module, and a user terminal; The data acquisition module is used to collect the outer surface images of the die-castings of the battery bracket from multiple perspectives and send them to the dimension detection module and the appearance detection module; The database is used to store the design drawings of the die-castings of the battery bracket and send the design drawings to the dimension detection module and the mechanical property detection module; The dimension detection module is used to detect the dimensions of the die-castings of the battery bracket, obtain a dimension abnormal signal or a dimension normal signal of the die-castings of the battery bracket, and send it to the user terminal; The appearance detection module is used to detect the appearance of the die-castings of the battery bracket. If there are air holes or cracks, an appearance abnormal signal is generated. If there are no air holes and cracks, an appearance normal signal is generated. The appearance detection module sends the appearance abnormal signal or the appearance normal signal to the user terminal; The mechanical property detection module is used to detect the mechanical properties of the die-castings of the battery bracket, obtain the mechanical abnormal rate of the die-castings of the battery bracket corresponding to the batches according to the detection results, and send it to the user terminal; The user terminal is used to receive the detection results at different stages. The user reads the user terminal to obtain the abnormal conditions of the die-castings of the battery bracket corresponding to the batches.

[0024] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not elaborate on all details and do not limit the present invention to only the specific embodiments. Obviously, according to the content of this specification, many modifications and variations can be made. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art in the relevant technical field can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. Step S1, collect the outer surface images of the battery bracket die-casting part from multiple perspectives; Step S2, perform dimensional inspection on the battery bracket die-casting part to obtain a dimensional anomaly signal or a dimensional normal signal of the battery bracket die-casting part; Step S3, perform appearance inspection on the battery bracket die-casting part. If there are pores or cracks, generate an appearance anomaly signal. If there are no pores and cracks, generate an appearance normal signal; Step S4, perform mechanical property inspection on the battery bracket die-casting part, and obtain the mechanical anomaly rate of the corresponding batch of battery bracket die-casting parts according to the inspection results; Step S5, learn about the anomaly situation of the corresponding batch of battery bracket die-casting parts based on the inspection results at different stages.

2. The detection method of a battery bracket die-casting part according to claim 1, characterized in that The said Step S2 includes the following sub-steps: Step S21, obtain the outer surface images of the battery bracket die-casting part from multiple perspectives, and splice the outer surface images from multiple perspectives to obtain the spliced appearance image of the battery bracket die-casting part; Step S22, establish a working coordinate system, take the center point of the bottom surface of the spliced appearance image as the origin, draw a straight line perpendicular to the bottom surface at the origin and denote it as the Z-axis, and draw two intersecting lines with the foot of the perpendicular at the origin in the bottom surface, and denote them as the X-axis and the Y-axis respectively; Step S23, read the corresponding mounting hole positions of the battery bracket die-casting part according to the spliced appearance image, take the center coordinates of the mounting hole positions as the hole positions coordinates of the mounting hole positions, and then obtain the design drawing of the battery bracket die-casting part, and read the corresponding preset hole positions coordinates and preset hole positions diameters of the battery bracket die-casting part according to the design drawing.

3. A method for detecting a die-cast part of a battery bracket according to claim 2, characterized in that, The said Step S2 also includes the following sub-steps: Step S24, compare the hole positions coordinates of the battery bracket die-casting part with the corresponding preset hole positions coordinates. If there is any hole positions coordinate of a mounting hole position different from the corresponding preset hole positions coordinate, generate a dimensional anomaly signal; if the hole positions coordinates of all mounting hole positions are the same as the corresponding preset hole positions coordinates, proceed to the subsequent steps; Step S25, measure the hole positions diameters of the corresponding mounting hole positions in combination with the hole positions coordinates of the mounting hole positions; compare the hole positions diameters with the corresponding preset hole positions diameters. If there is any hole positions diameter of a mounting hole position different from the corresponding preset hole positions diameter, generate a dimensional anomaly signal; if the hole positions diameters of all mounting hole positions are the same as the corresponding preset hole positions diameters, execute the subsequent steps; Step S26, regard the spliced appearance image of the battery bracket die-casting part as a cube, measure the length, width and height of the cube, and then obtain the bottom surface area of the corresponding bottom surface of the cube and the side surface areas of the four groups of side surfaces.

4. A method for detecting a die-cast part of a battery bracket according to claim 2, characterized in that, The said Step S2 also includes the following sub-steps: Step S27, obtain the number of measurement points according to the bottom surface area and the side surface areas, mark the corresponding number of measurement points at any position on the bottom surface and the side surfaces, and record the coordinates of the measurement points; measure the distance between adjacent measurement points in the same plane and denote it as the plane dimension distance, and then obtain a plurality of plane dimension distances corresponding to the bottom surface and the four side surfaces; Step S28, mark the same number of measurement points at the same position in the design drawing, and then obtain the standard plane dimension distance corresponding to the plane dimension distance; calculate the absolute value of the difference between the plane dimension distance and the standard plane dimension distance and denote it as the plane distance difference value; Step S29: Compare multiple groups of planar distance difference values with the planar distance difference threshold. If any group of planar distance difference values is greater than or equal to the planar distance difference threshold, generate a size anomaly signal; if all planar distance difference values are less than the planar distance difference threshold, generate a size normal signal.

5. A method for detecting a die-cast part of a battery bracket according to claim 1, wherein, The said step S4 includes the following sub-steps: Step S41: Select a fixed number of battery tray die-castings from the same batch of battery tray die-castings as mechanical sample die-castings, and divide the mechanical sample die-castings into two parts evenly, which are used for mechanical tensile testing and mechanical hardness testing in sequence. Step S42: Perform mechanical tensile testing to obtain the number of tensile anomalies corresponding to the mechanical sample die-castings under mechanical tensile testing. Step S43: Perform mechanical hardness testing to obtain the number of hardness anomalies corresponding to the mechanical sample die-castings under hardness testing. Step S44: Add the number of hardness anomalies to the number of tensile anomalies to obtain the number of mechanical anomalies; divide the number of mechanical anomalies by the total number of mechanical sample die-castings to obtain the mechanical anomaly rate of the corresponding batch of battery tray die-castings.

6. The detection method of a battery bracket die-casting part according to claim 5, characterized in that, The specific process of the said mechanical tensile testing is as follows: Step S421: Select any one of the mechanical sample die-castings, clamp the mechanical sample die-casting in the fixture of a universal tensile testing machine, select two marking points on the mechanical sample die-casting, and record the distance between the marking points as the original gauge length; set the tensile rate of the mechanical tensile testing. Step S422: Adjust the tensile load and record the load-displacement curve corresponding to the mechanical sample die-casting until the mechanical sample die-casting is torn; measure the distance between the two marking points again and record it as the gauge length after fracture. Step S423: Read the maximum load from the load-displacement curve, and calculate the tensile strength of the mechanical sample die-casting based on the maximum load. The calculation formula is: Tensile strength = Maximum load / Sample cross-sectional area.

7. A method for detecting a die-cast part of a battery bracket according to claim 6, characterized in that, The said mechanical tensile testing process also includes: Step S424: Draw a straight line parallel to the linear stage in the load-displacement curve with an offset of 0.2% strain, record the intersection point of the straight line and the load-displacement curve as the yield point, read the yield load of the yield point, and divide the yield load by the sample cross-sectional area to obtain the yield strength of the mechanical sample die-casting. Step S425: Calculate the elongation rate of the mechanical sample die-casting through the formula. The specific formula is as follows: Elongation rate = (Gauge length after fracture - Original gauge length) / Original gauge length × 100% Step S426: Compare the tensile strength, yield strength, and elongation rate of the mechanical sample die-castings with the corresponding thresholds in sequence; if any one of the tensile strength, yield strength, and elongation rate of the mechanical sample die-castings is less than the corresponding threshold, mark the mechanical sample die-casting as a tensile anomaly die-casting; if the tensile strength, yield strength, and elongation rate of the mechanical sample die-castings are all greater than the corresponding thresholds, mark the mechanical sample die-casting as a mechanically qualified die-casting. Step S427: Perform mechanical tensile testing on all the mechanical sample die-castings, and count the number of tensile anomaly die-castings as the number of tensile anomalies.

8. A method for detecting die-castings of a battery bracket according to claim 5, characterized in that The specific process of the said mechanical hardness testing is as follows: Step S431: Arbitrarily select a mechanical sample die-casting part, and uniformly select multiple hardness detection points on the surface of the mechanical sample die-casting part; Step S432: Read the corresponding required hardness range according to the design drawing corresponding to the mechanical sample die-casting part, and select the indenter and indenter load ZH for hardness detection according to the required hardness range, the material type and thickness of the mechanical sample die-casting part; Step S433: Apply a force equal to the indenter load on the hardness detection point through the indenter for a holding time, and record the indentation depth and indentation diameter; Step S434: Compare the indentation depth with the sample thickness of the mechanical sample die-casting part. If the sample thickness of the mechanical sample die-casting part is less than eight times the indentation depth, replace the indenter; if the sample thickness of the mechanical sample die-casting part is greater than or equal to eight times the indentation depth, proceed to the subsequent steps.

9. A method for detecting a die-cast part of a battery bracket according to claim 8, characterized in that, The detection process of the mechanical hardness detection further includes: Step S435: Calculate the calculated hardness value JY of the mechanical sample die-casting part through a formula, and the specific calculation formula is as follows: ; where π is the ratio of a circle's circumference to its diameter, D is the indenter diameter, and d is the indentation diameter; Step S436: Compare the calculated hardness value of the mechanical sample die-casting part with the required hardness range. If the calculated hardness value of any hardness detection point is outside the required hardness range, mark the corresponding mechanical sample die-casting part as a hardness-abnormal die-casting part; if the calculated hardness values of all hardness detection points are within the required hardness range, mark the corresponding mechanical sample die-casting part as a hardness-qualified die-casting part; Step S437: Perform hardness detection on all mechanical sample die-casting parts, and record the number of hardness-abnormal die-casting parts as the hardness abnormality number.

10. A battery bracket die-casting part detection system, characterized in that, A method for detecting a battery bracket die-casting part according to any one of claims 1-9, comprising a database, a data acquisition module, a dimension detection module, an appearance detection module, a mechanical property detection module, and a user terminal; The data acquisition module is used to collect the outer surface images of the battery bracket die-casting part from multiple perspectives and send them to the dimension detection module and the appearance detection module; The database is used to store the design drawings of the battery bracket die-casting part and send the design drawings to the dimension detection module and the mechanical property detection module; The dimension detection module is used to perform dimension detection on the battery bracket die-casting part, obtain a dimension abnormality signal or a dimension normal signal of the battery bracket die-casting part, and send it to the user terminal; The appearance detection module is used to perform appearance detection on the battery bracket die-casting part. If there are pores or cracks, generate an appearance abnormality signal; if there are no pores and cracks, generate an appearance normal signal. The appearance detection module sends the appearance abnormality signal or the appearance normal signal to the user terminal; The mechanical property detection module is used to perform mechanical property detection on the battery bracket die-casting part, obtain the mechanical abnormality rate of the corresponding batch of battery bracket die-casting parts according to the detection results, and send it to the user terminal; The user terminal is used to receive the detection results at different stages, and the user reads the user terminal to know the abnormality situation of the corresponding batch of battery bracket die-casting parts.

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