A method and system for detecting surface defects of die castings of motor casing

Abstract

The present invention discloses a method and system for detecting surface defects of a motor casing die-casting. The present invention relates to the technical field of casing defect detection, and solves the problem that the identification and processing process of related wing-shaped pieces on the casing surface is relatively cumbersome, which will cause the identification and processing process to be slow, thereby affecting the inspection efficiency of the corresponding casing. The present invention identifies whether there are concave surfaces or other conditions on the surfaces of the wing-shaped pieces by expressing the distance between adjacent wing-shaped pieces of corresponding models, and performs preliminary detection on the surface defects of the motor casing die-casting to identify whether there are related abnormalities on the surface; subsequently, different circle construction methods are adopted to determine whether there are angle abnormalities or spacing abnormalities of the wing-shaped pieces by identifying the related performance parameters of the related wing-shaped pieces on the casing surface. The analysis surface is wider, and compared with the original classification processing method, the processing efficiency is higher and the time is shorter, so the detection and analysis processing effect can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of casing defect detection, and in particular to a method and system for detecting surface defects of a die-casting casing of a motor. Background Art

[0002] Motor housing die castings generally refer to die-casting products used to manufacture motor housings. Due to the complexity of components such as motor housings, they are usually designed as castings; this helps meet the requirements of high power density and functional integration, sometimes involving complex shapes and structures.

[0003] The application with publication number CN109541017A discloses a detection device and detection method for surface defects of castings, including a base, a first detection chamber is arranged at the upper end of the base, and a control panel is installed at the upper end of the base near the first detection chamber, and a second detection chamber is installed at the upper end of the base at the other side of the first detection chamber. The present invention uses eddy current detection to detect defects on the surface of castings, and then cooperates with X-ray detection to facilitate the detection of deficiencies inside and on the surface of castings, and displays them on a display screen, which is convenient for staff to observe and compare, and can also further detect the weight difference of castings of the same model, and at the same time use the second detection chamber to detect the wear resistance of the castings, detect the durability of the castings, and cooperate with the magnetic coil to detect the deviation of the wear resistance of the castings at different temperatures, which is convenient for staff to compare and further improve the accuracy of the detection data.

[0004] During defect detection of die-castings of motor casings, the feedback detection parameters of the corresponding die-castings are generally used to identify whether the corresponding die-castings have relevant defects. However, the identification and processing process of the relevant wing-shaped pieces on the surface of the casing is relatively cumbersome, which will cause the efficiency of the identification and processing process to be slow, thereby affecting the inspection efficiency of the corresponding casing and causing the casing to be produced slowly. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method and system for detecting surface defects of die-cast motor casings, which solves the problem that the identification and processing process of the relevant wing-shaped pieces on the surface of the casing is relatively cumbersome, resulting in a slow identification and processing efficiency, thereby affecting the inspection efficiency of the corresponding casing.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for detecting surface defects of a motor housing die casting comprises the following steps:

[0007] S1) Use CT scanning equipment to scan the motor housing die casting, and based on the scanning results, generate a relevant model of the die casting, and compare this relevant model with the preset standard model to confirm whether there are relevant abnormalities on the surface of the motor housing die casting, including:

[0008] Based on the feature points set by the preset standard model, the relevant points corresponding to the relevant models are locked. The feature points are set in advance by the operator. Based on the same confirmation method of the feature points, the corresponding points in the relevant models are locked, and based on the same points, the two sets of relevant models are compared:

[0009] Confirm whether the comparison results of the relevant base surface of the constructed relevant model are consistent with the relevant base surface of the preset standard model. If they are completely consistent, then perform subsequent analysis and processing. If they are not completely consistent, then directly mark the die casting as a substandard part and display it;

[0010] S2) Confirm and partition the wing-shaped pieces in different areas of the die casting related model surface in sequence, and confirm the distance between adjacent wing-shaped pieces belonging to the same area to identify whether the distance values ​​of the opposite points are consistent, so as to determine whether the wing-shaped pieces are bent, including:

[0011] Determine the center point of its wing-like piece and the distance J between the center points of adjacent wing-like pieces. If J≤Y1, the corresponding wing-like piece is calibrated as the wing-like piece in the same area. Otherwise, no calibration is performed. By processing several groups of adjacent wing-like pieces in sequence, the wing-like pieces in the same area in different areas can be confirmed.

[0012] The vertical spacing between adjacent wing pieces belonging to the same area is analyzed, and based on the opposite surfaces of the corresponding adjacent wing pieces, N groups of related vertical lines are constructed, and the vertical points of several groups of related vertical lines are respectively located in the opposite surfaces of the adjacent wing pieces. It is identified whether the distance values ​​of the N groups of related vertical lines are consistent. If they are consistent, it means that the adjacent wing pieces are standard wing pieces. If they are inconsistent, the die casting is marked as a substandard part and displayed;

[0013] If all the wing-shaped pieces in the same area are standard wing-shaped pieces, it means that the surface of the corresponding wing-shaped piece is a normal smooth plane, and there is no relevant curved surface. Subsequent analysis and processing are performed. If it does not belong to the standard wing-shaped piece;

[0014] S3) Determine the positive view surface of the die casting related model, lock the relevant center of the inner circle of the positive view surface, make a set of initial circles based on the relevant center, and the initial circles intersect with each group of wing pieces in the same partition and are in the maximum area state, and determine whether there are relevant problems with the wing pieces based on the relevant numerical state of the initial circles and each group of wing pieces in the same partition or by combining the initial circles to create subsequent outer circles;

[0015] Preferably, the specific sub-step of determining whether the wing pieces have a correlation problem based on the correlation numerical state between the initial circle and each group of wing pieces in the same partition includes:

[0016] Based on the characteristic points of the corresponding die casting related model, the positive view surface of the related model is directly locked;

[0017] A group of wing pieces in the same partition to be analyzed is identified, an initial circle belonging to the wing pieces in the same partition is constructed, the intersection of the initial circle and different wing pieces in the partition is identified, and the vertical distance L between the intersection and the vertex in the vertical direction of the wing piece is determined. Based on the location of the corresponding wing piece, starting from one wing piece on one side and ending at the other wing piece on the other side, a plurality of groups of vertical distances L are arranged one by one in a one-to-one correspondence manner to generate a vertical distance arrangement set;

[0018] Identify the number of distances in a vertical distance arrangement set:

[0019] If it is an even number: compare the first set of vertical distances with the last set of vertical distances, and then compare the second set of vertical distances with the second last set of vertical distances. Use this method to compare one by one to determine whether the compared vertical distances are the same. If the vertical distances are the same in all the comparison processes, no calibration is performed. If there is a set of comparison processes with different vertical distances, the corresponding wing-shaped piece is directly locked, marked as an abnormal wing-shaped piece and displayed;

[0020] If it is an odd number: then eliminate the middle set of values ​​in the vertical distance arrangement set, and then use the comparison method whose number of distances is an even number to compare the relevant vertical distances one by one to lock the corresponding abnormal wing-shaped piece.

[0021] Preferably, the specific sub-steps of determining whether the wing-shaped piece has relevant problems by combining the initial circle with the method of creating the subsequent outer circle include:

[0022] Based on the characteristic points of the corresponding die casting related model, the positive view surface of the related model is directly locked;

[0023] A group of wing-shaped pieces in the same partition to be analyzed is identified, an initial circle belonging to the wing-shaped pieces in the same partition is constructed, a wing-shaped piece that is tangent to the initial circle is marked as an intermediate wing-shaped piece, and then outer circles tangent to other wing-shaped pieces are constructed in sequence, the center of the outer circle is also the relevant center, and a circle array is generated based on the initial circle and several groups of outer circles;

[0024] Starting from the outer circle of the circle array to the inner circle, determine the radius difference between adjacent circles. The radius difference = the radius of the outer circle of the adjacent circle - the radius of the inner circle of the adjacent circle. According to the determination method from the outside to the inside, arrange several groups of radius differences one by one to generate a radius difference sequence.

[0025] Determine whether the radius difference sequence conforms to the preset regular equation, where the regular equation is determined in advance based on the relevant standard parts of the corresponding preset standard model. If it conforms, no processing is performed. If it does not conform, the corresponding radius difference is calibrated as an abnormal difference. Based on the two sets of consecutive abnormal differences, the abnormal circle is determined, and the abnormal wing piece is locked and displayed.

[0026] Preferably, a system for detecting surface defects of a motor housing die casting comprises:

[0027] CT scanner, which scans the motor housing die-casting to be inspected and determines the relevant model of the die-casting based on the scanning results;

[0028] The relevant processor compares the relevant model with the preset standard model to determine whether there are cracks, bubbles or other abnormalities on the surface of the motor housing die casting;

[0029] The partition processor confirms the distance between adjacent wing pieces belonging to the same area and identifies whether the distance values ​​of the opposite points are consistent. If they are consistent, it means that the adjacent wing pieces are standard wing pieces. If they are inconsistent, the die casting is marked as a substandard part and displayed;

[0030] The main processor locks the relevant center of the inner circle of the positive straight-view surface of the die-casting related model, makes a group of initial circles based on the relevant center, and determines whether there are relevant problems with the wing-shaped pieces based on the relevant numerical states of the initial circles and each group of wing-shaped pieces in the same partition or by combining the initial circles to create subsequent relevant circles.

[0031] The present invention provides a method and system for detecting surface defects of die-casting parts of a motor housing. Compared with the prior art, the method has the following beneficial effects:

[0032] The present invention compares the scanned related model with the preset model to confirm whether there are related cracks and bubbles. Subsequently, based on the distance performance of adjacent wing-shaped pieces between the corresponding models, it is identified whether there are concave surfaces or other conditions on the surface of the wing-shaped pieces, and the surface defects of the motor housing die-casting are preliminarily detected to identify whether there are related abnormalities on the surface.

[0033] Subsequently, different circle construction methods were adopted to identify the relevant performance parameters of the wing-shaped pieces on the surface of the casing to determine whether the wing-shaped pieces had abnormal angles or abnormal spacing. The analysis scope was wider and the processing efficiency was higher and the time was shorter than the original classification processing method, thus achieving the detection and analysis processing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the process of the present invention;

[0035] Figure 2 This is a schematic diagram related to the initial circle of the present invention;

[0036] Figure 3 Schematic diagram of the circle array of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Embodiment 1

[0039] See also Figure 1 The present application provides a method for detecting surface defects of a motor casing die casting, comprising the following steps:

[0040] S1) Use CT scanning equipment to scan the motor housing die casting, and based on the scanning results, generate a relevant model of the die casting, and compare the relevant model with the preset standard model to confirm whether there are relevant abnormalities on the surface of the motor housing die casting, where the relevant abnormalities include cracks, bubbles and other related defects. The detailed process of comparison includes:

[0041] Based on the characteristic points set by the preset standard model, the corresponding points of the relevant models are locked. The characteristic points are set in advance by the operator, generally the center point and other characteristic points. Based on the same confirmation method of the characteristic points, the corresponding points in the relevant models are locked, and based on the same points, the two groups of relevant models are compared. There are many ways to confirm the characteristic points, and the specific determination form is determined in combination with the actual application scenario. When placing the die-casting model, the corresponding standard line can be determined according to the center point and the center point of other edge lines, and the model comparison is performed based on this standard line later;

[0042] Confirm whether the comparison result of the relevant base surface of the constructed relevant model is consistent with the relevant base surface of the preset standard model. If they are completely consistent, subsequent analysis and processing are carried out. If they are not completely consistent, the die-casting is directly calibrated as a substandard part and displayed (specifically, the relevant base surface is determined in advance by the operator, and it can also be understood that only surface comparison is performed here, and no other size or other type of comparison is performed. It belongs to the initial comparison process. Through the comparison result, it is determined whether there is an abnormality, including related defects such as cracks and bubbles, which can be directly determined by the initial comparison. Because the method of determining the abnormality of the die-casting by model comparison is relatively common in the prior art, it will not be described in detail here, and there are various ways to identify cracks and bubbles. This application only describes a relatively simple method. Other methods include single model feature comparison, or based on feature points and combined with corresponding feature algorithms, identify and determine the feature parameters of the corresponding related area, and compare whether the feature parameters of the same area are consistent to determine whether the die-casting has related abnormalities);

[0043] S2) sequentially confirm and partition the wing-shaped pieces in different areas of the surface of the die casting related model, and confirm the distance between adjacent wing-shaped pieces belonging to the same area, and identify whether the distance values ​​of the opposite points are consistent, so as to determine whether the wing-shaped pieces are bent, wherein the specific method of determination includes:

[0044] Determine the center point of its wing-like piece and the distance J between the center points of adjacent wing-like pieces. If J≤Y1, the corresponding wing-like piece is calibrated as the wing-like piece in the same area. Otherwise, no calibration is performed. By processing several groups of adjacent wing-like pieces in sequence, the wing-like pieces in the same area in different areas can be confirmed.

[0045] Analyze the vertical spacing between adjacent wing pieces belonging to the same area, and construct N groups of related vertical lines based on the opposite surfaces of the corresponding adjacent wing pieces. The vertical points of several groups of related vertical lines are respectively located in the opposite surfaces of the adjacent wing pieces, where N is not less than 50. Identify whether the distance values ​​of the N groups of related vertical lines are consistent. If they are consistent, it means that the adjacent wing pieces are standard wing pieces. If they are inconsistent, the die casting is marked as a substandard part and displayed;

[0046] If all the wing-shaped pieces in the same area are standard wing-shaped pieces, it means that the surface of the corresponding wing-shaped piece is a normal smooth plane, and there is no relevant curved surface. Subsequent analysis and processing are performed. If it does not belong to the standard wing-shaped piece;

[0047] Specifically, the corresponding wing pieces are located around the motor housing. The reason for analyzing the distance between the wing pieces is that the adjacent wing pieces are in a parallel state after leaving the factory. When the wing pieces are concave or other situations occur, the corresponding distance values ​​will change accordingly. After the motor housing leaves the factory, some external collisions or other situations may cause the corresponding wing pieces to bend and other situations may occur, which will cause related problems when the corresponding wing pieces are used later, causing adverse effects.

[0048] S3) Determine the front view surface of the die casting related model, lock the relevant center of the inner circle of the front view surface, and make a set of initial circles based on the relevant center. The initial circles intersect with each group of wing-shaped pieces in the same partition and are in the maximum area state. Based on the relevant numerical state of the initial circles and each group of wing-shaped pieces in the same partition or by combining the initial circles to create subsequent relevant circles, determine whether there are relevant problems with the wing-shaped pieces. Specifically, the front view surface of the related model can be understood as the side view of the corresponding die casting, such as Figure 2 As shown, the corresponding center circle and the corresponding wing-shaped pieces in different areas of the outer surface of the housing can be clearly confirmed from the side view. The original process of analyzing the wing-shaped pieces includes: analyzing the distance between each wing-shaped piece, determining whether the distance between them is greatly different, and then analyzing the symmetry of each wing-shaped piece to identify whether the wing-shaped piece has an angle deviation. The present application adopts a method of constructing a related circle, which can directly cover the original two analysis situations. The method of the present application can be used to perform related processing, and the processing efficiency is high and the time is shorter;

[0049] As the first processing method in step S3), based on the relevant numerical states of the initial circle and each group of wing-shaped pieces in the same partition, the specific sub-steps of determining whether there are relevant problems with the wing-shaped pieces include:

[0050] Based on the characteristic points of the corresponding die casting related model, the positive view surface of the related model is directly locked (the system can also directly determine its positive view surface based on the associated lines and associated coordinates generated by the model. During the model generation process, each related surface of the model is confirmed and marked);

[0051] Confirm a group of wing-shaped pieces in the same partition to be analyzed, and construct an initial circle belonging to the wing-shaped pieces in the same partition (specifically, the center of the initial circle is the center of the relevant circle, and it needs to continue to intersect with the wing-shaped pieces in the process of gradually increasing. Regardless of whether the specific number of wing-shaped pieces is an odd number or an even number, this method can be used to determine the corresponding initial circle, and the innermost wing-shaped piece is tangent to the initial circle. If it is an odd number, the middle wing-shaped piece is tangent to the initial circle. If it is an even number, the two groups of wing-shaped pieces opposite to each other in the middle are tangent to the initial circle), confirm the intersection point of the initial circle with different wing-shaped pieces in the partition, determine the vertical distance L between the intersection point and the vertex in the vertical direction of the wing-shaped piece, and based on the location of the corresponding wing-shaped piece, start from one side of the wing-shaped piece and end at the other side of the wing-shaped piece, and arrange several groups of vertical distances L one by one in a one-to-one correspondence to generate a vertical distance arrangement set;

[0052] Identify the number of distances in a vertical distance arrangement set:

[0053] If it is an even number: compare the first set of vertical distances with the last set of vertical distances, and then compare the second set of vertical distances with the second last set of vertical distances. Use this method to compare one by one to determine whether the compared vertical distances are the same. If the vertical distances are the same in all the comparison processes, no calibration is performed. If there is a set of comparison processes with different vertical distances, the corresponding wing piece is directly locked, marked as an abnormal wing piece and displayed (later, the operator can directly determine the specific die-casting area based on this abnormal wing piece to perform identification and maintenance to determine whether there is a problem in the die-casting area);

[0054] If it is an odd number: then eliminate the middle set of values ​​in the vertical distance arrangement set, and then use the comparison method whose number of distances is an even number to compare the relevant vertical distances one by one to lock the corresponding abnormal wing-shaped piece.

[0055] Combined with the example: if the generated vertical distance arrangement set is {5, 4, 3, 2, 0, 2, 3, 4, 5}, and the number of internal values ​​is an odd number, then the middle value is eliminated, and the middle value does not have any relevant comparison items and needs to be eliminated. Based on the setting rule of sequential comparison, the value comparison is correct. If the vertical distance arrangement set is {5, 4, 3, 2, 2, 3, 4, 5}, and the number of internal values ​​is an even number, then the setting rule of sequential comparison is also used to determine the final comparison result;

[0056] If the corresponding wing-shaped piece does not meet the standard or there is a related abnormality, the corresponding vertical distance generated will have a corresponding error, and the related numerical comparison result will have an error, so the abnormal wing-shaped piece can be determined.

[0057] As the second processing method in step S3), the specific sub-steps of determining whether the wing-shaped piece has relevant problems by combining the initial circle with the subsequent outer circle to create the subsequent outer circle include:

[0058] Based on the characteristic points of the corresponding die casting related model, the positive view surface of the related model is directly locked;

[0059] Confirm a group of wing pieces in the same partition to be analyzed, construct the initial circle belonging to the wing piece in the same partition, mark the wing piece that is tangent to the initial circle as the middle wing piece, and then construct the outer circle tangent to other wing pieces in turn, and the center of the outer circle is also the center of the related circle, such as Figure 3 As shown, a circle array is generated based on an initial circle and several groups of outer circles;

[0060] Starting from the outer circle of the circle array to the inner circle, determine the radius difference between adjacent circles. The radius difference = the radius of the outer circle of the adjacent circle - the radius of the inner circle of the adjacent circle. According to the determination method from the outside to the inside, arrange several groups of radius differences one by one to generate a radius difference sequence.

[0061] Determine whether the radius difference sequence conforms to the preset regular equation, wherein the regular equation is determined in advance based on the relevant standard parts of the corresponding preset standard model. If it conforms, no processing is performed. If it does not conform, the corresponding radius difference is calibrated as an abnormal difference. Based on the two groups of abnormal differences that appear continuously, determine the abnormal circle, lock the abnormal wing-shaped piece and display it. Specifically, the abnormal difference will not appear in a single group, but will appear continuously. When the corresponding circle belongs to the abnormal circle, the related differences on both sides will change accordingly. Therefore, based on the related continuously appearing abnormal differences, the corresponding abnormal circle can be locked, and the corresponding abnormal wing-shaped piece can be directly locked.

[0062] Example: The relevant regular equation is generally Y=kx-b, where k represents the number of circles from the outside to the inside. If it is the first circle, its x is 1, then the difference is Y=xb; if it is the second circle, its x is 2, and the difference is Y=2k-b. Both k and b are determined in advance by the relevant standard parts of the corresponding preset standard model. If the corresponding die-casting is a standard part, its wing-shaped pieces must be evenly arranged, so the change in the difference must conform to the relevant law and belong to the relevant regular equation.

[0063] As the relevant operating system for executing this test method:

[0064] A system for detecting surface defects of a motor housing die casting, comprising:

[0065] CT scanner, which scans the motor housing die-casting to be inspected and determines the relevant model of the die-casting based on the scanning results;

[0066] The relevant processor compares the relevant model with the preset standard model to determine whether there are cracks, bubbles or other abnormalities on the surface of the motor housing die casting;

[0067] The partition processor confirms the distance between adjacent wing pieces belonging to the same area and identifies whether the distance values ​​of the opposite points are consistent. If they are consistent, it means that the adjacent wing pieces are standard wing pieces. If they are inconsistent, the die casting is marked as a substandard part and displayed;

[0068] The main processor determines the forward viewing surface of the die casting related model, locks the relevant center of the inner circle of the forward viewing surface, and makes a set of initial circles based on the relevant center. The initial circles intersect with each group of wing-shaped pieces in the same partition and are in the maximum area state. Based on the relevant numerical state of the initial circles and each group of wing-shaped pieces in the same partition or by combining the initial circles to create subsequent relevant circles, it is determined whether there are relevant problems with the wing-shaped pieces.

[0069] Some of the data in the above formulas are dimensionless and numerically calculated. Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0070] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for detecting surface defects of die castings of motor casings, characterized in that: The following steps are involved: S1) Scan the motor housing die casting with CT scanning equipment, and generate a relevant model of the die casting based on the scanning results, and compare the relevant model with the preset standard model to confirm whether there are relevant abnormalities on the surface of the motor housing die casting; S2) sequentially confirm and partition the wing-shaped pieces in different areas of the surface of the die casting related model, and confirm the distance between adjacent wing-shaped pieces belonging to the same area to identify whether the distance values ​​of the opposite points are consistent, so as to determine whether the wing-shaped pieces are bent; S3) Determine the positive view surface of the die casting related model, lock the relevant center of the inner circle of the positive view surface, and make a set of initial circles based on the relevant center. The initial circles intersect with each group of wing pieces in the same partition and are in the maximum area state. Based on the relevant numerical state of the initial circles and each group of wing pieces in the same partition or by combining the initial circles to create subsequent outer circles, determine whether there are related problems with the wing pieces: Based on the relevant numerical states of the initial circle and each group of wing pieces in the same partition, the specific sub-steps of determining whether the wing pieces have relevant problems include: Based on the characteristic points of the corresponding die casting related model, the positive view surface of the related model is directly locked; A group of wing pieces in the same partition to be analyzed is identified, an initial circle belonging to the wing pieces in the same partition is constructed, the intersection of the initial circle and different wing pieces in the partition is identified, and the vertical distance L between the intersection and the vertex in the vertical direction of the wing piece is determined. Based on the location of the corresponding wing piece, starting from one wing piece on one side and ending at the other wing piece on the other side, a plurality of groups of vertical distances L are arranged one by one in a one-to-one correspondence manner to generate a vertical distance arrangement set; Identify the number of distances in a vertical distance arrangement set: If it is an even number: compare the first set of vertical distances with the last set of vertical distances, and then compare the second set of vertical distances with the second last set of vertical distances. Use this method to compare one by one to determine whether the compared vertical distances are the same. If the vertical distances are the same in all the comparison processes, no calibration is performed. If there is a set of comparison processes with different vertical distances, the corresponding wing-shaped piece is directly locked, marked as an abnormal wing-shaped piece and displayed; If it is an odd number: remove the middle set of values ​​in the vertical distance arrangement set, and then use the comparison method whose distance number is an even number to compare the relevant vertical distances one by one to lock the corresponding abnormal wing-shaped piece; The specific sub-steps of determining whether there are relevant problems with the wing-shaped piece by combining the initial circle with the method of creating the subsequent outer circle include: Based on the characteristic points of the corresponding die casting related model, the positive view surface of the related model is directly locked; A group of wing-shaped pieces in the same partition to be analyzed is identified, an initial circle belonging to the wing-shaped pieces in the same partition is constructed, a wing-shaped piece that is tangent to the initial circle is marked as an intermediate wing-shaped piece, and then outer circles tangent to other wing-shaped pieces are constructed in sequence, the center of the outer circle is also the relevant center, and a circle array is generated based on the initial circle and several groups of outer circles; Starting from the outer circle of the circle array to the inner circle, determine the radius difference between adjacent circles. The radius difference = the radius of the outer circle of the adjacent circle - the radius of the inner circle of the adjacent circle. According to the determination method from the outside to the inside, arrange several groups of radius differences one by one to generate a radius difference sequence. Determine whether the radius difference sequence conforms to the preset regular equation, where the regular equation is determined in advance based on the relevant standard parts of the corresponding preset standard model. If it conforms, no processing is performed. If it does not conform, the corresponding radius difference is calibrated as an abnormal difference. Based on the two sets of consecutive abnormal differences, the abnormal circle is determined, and the abnormal wing piece is locked and displayed.

2. A method for detecting surface defects of a motor casing die casting according to claim 1, characterized in that: In step S1, the specific method of comparing the relevant model with the preset standard model includes: Based on the feature points set by the preset standard model, the relevant points corresponding to the relevant models are locked. The feature points are set in advance by the operator. Based on the same confirmation method of the feature points, the corresponding points in the relevant models are locked, and based on the same points, the two sets of relevant models are compared: Confirm whether the comparison results of the relevant base surface of the constructed relevant model are consistent with the relevant base surface of the preset standard model. If they are completely consistent, subsequent analysis and processing will be carried out. If they are not completely consistent, the die-casting part will be directly calibrated as a substandard part and displayed.

3. The method for detecting surface defects of a motor housing die casting according to claim 1, characterized in that: In step S2, the specific method of determining whether the wing-shaped piece is bent includes: Determine the center point of its wing-like piece and the distance J between the center points of adjacent wing-like pieces. If J≤Y1, the corresponding wing-like piece is calibrated as the wing-like piece in the same area. Otherwise, no calibration is performed. By processing several groups of adjacent wing-like pieces in sequence, the wing-like pieces in the same area in different areas can be confirmed. The vertical spacing between adjacent wing pieces belonging to the same area is analyzed, and based on the opposite surfaces of the corresponding adjacent wing pieces, N groups of related vertical lines are constructed, and the vertical points of several groups of related vertical lines are respectively located in the opposite surfaces of the adjacent wing pieces. It is identified whether the distance values ​​of the N groups of related vertical lines are consistent. If they are consistent, it means that the adjacent wing pieces are standard wing pieces. If they are inconsistent, the die casting is marked as a substandard part and displayed; If all the wing-shaped pieces in the same area are standard wing-shaped pieces, it means that the surface of the corresponding wing-shaped piece is a normal smooth plane, there is no relevant curved surface, and subsequent analysis and processing are performed.

4. A detection system for surface defects of die-castings of motor casings, the detection system is operated based on the detection method according to any one of claims 1 to 3, characterized in that: include: CT scanner, which scans the motor housing die-casting to be inspected and determines the relevant model of the die-casting based on the scanning results; The relevant processor compares the relevant model with the preset standard model to determine whether there are cracks or bubbles on the surface of the motor housing die casting; The partition processor confirms the distance between adjacent wing pieces belonging to the same area and identifies whether the distance values ​​of the opposite points are consistent. If they are consistent, it means that the adjacent wing pieces are standard wing pieces. If they are inconsistent, the die casting is marked as a substandard part and displayed; The main processor locks the relevant center of the inner circle of the positive straight-view surface of the die-casting related model, makes a group of initial circles based on the relevant center, and determines whether there are relevant problems with the wing-shaped pieces based on the relevant numerical states of the initial circles and each group of wing-shaped pieces in the same partition or by combining the initial circles to create subsequent relevant circles.

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