An automated design method for draft angle of wheel hub forgings

Abstract

This invention proposes an automated design method for draft angles of wheel hub forgings, belonging to the field of intelligent manufacturing technology. It solves the problems of excessive reliance on designer experience in draft angle design, significant variations in draft angle designs, and low efficiency in drawing draft angles. It includes the following steps: Step 1: Identify all line types on one side of the forging centerline and place them into a single bus line type set; Step 2: Locate the parting surface line type and perform parting, then remove the line type from the bus line type set; Step 3: Determine the inner hole form, locate the inner hole line type, and remove it from the bus line type set; Step 4: Differentiate between upper and lower dies for the line types in the set; Step 5: Design the draft angle for the line types requiring drafting according to the draft angle design rules. It is mainly used for the automated design of draft angles for wheel hub forgings.

Description

Technical Field

[0001] This invention belongs to the field of intelligent manufacturing technology, and in particular relates to an automated design method for the draft angle of wheel hub forgings. Background Technology

[0002] Forging plays a vital role in the national economy. In various manufacturing sectors, such as automobiles, metallurgy, machine tools, and aerospace, many critical components require forging to be manufactured into finished or semi-finished products. Die forging is a major process in forging production, offering advantages such as high production efficiency, stable forging dimensions, and high material utilization. With increasing global competition, low cost, high quality, and high efficiency are key factors for success in modern manufacturing. Therefore, designing and manufacturing these dies efficiently and cost-effectively is a primary concern in the forging industry. It is well known that the quality of the process and die design directly affects the final forging quality, cost, production efficiency, and die lifespan. However, die forging and die design are complex, knowledge- and experience-intensive processes. The die design process requires consulting numerous design manuals and performing extensive dimensional calculations to finalize the die dimensions, undoubtedly increasing product development and manufacturing costs and impacting a company's competitiveness.

[0003] The design of the draft angle for forgings affects the ejection and machining allowances of the forgings, making it a crucial aspect of forging design. It is generally selected based on the designer's experience. However, due to varying levels of experience, significant differences arise in the design of draft angles. Furthermore, for complex forgings, there may be numerous straight edge segments requiring draft angles, each necessitating draft angle selection, thus making it a very time-consuming design task. Forging design and process engineers, there is an urgent need for a method that can efficiently identify straight edge segments in forgings and automatically derive the draft angle from the forging according to pre-defined design rules. Summary of the Invention

[0004] In view of this, the present invention aims to propose an automated design method for draft angles of wheel hub forgings, in order to solve the problems of excessive reliance on designer experience in the current design of draft angles of wheel hub forgings, large degree of variability in draft angle design, and low efficiency in drawing draft angles.

[0005] 1. To achieve the above objectives, the present invention adopts the following technical solution: an automated design method for the draft angle of a wheel hub forging, wherein the forging has a universal joint inner hole, the method comprising the following steps:

[0006] Step 1: Identify all line types on one side of the centerline of the forging and put them into a single bus line type set;

[0007] Step 2: Find the parting surface line type according to the parting surface design rules and perform parting, then remove the line type from the bus line type set;

[0008] Step 3: Based on the input set of coordinate points of the universal joint inner hole of the wheel hub forging, determine the inner hole form, find the inner hole line type, and remove the line type from the bus line type set;

[0009] Step 4: Distinguish between upper and lower dies in the line types in the set. Store all upper die line types in the defined upper die line type set by connecting the first and last lines according to the sorting algorithm. Store all lower die line types in the lower die line type set by connecting the first and last lines.

[0010] Step 5: Design the draft angle for the line type that needs to be drafted according to the design rules of the draft angle, and then symmetrically transfer the line type from one side to the other side through the center line to complete the draft angle of the forging.

[0011] Furthermore, the parting surface line type includes the upper parting surface line type and the lower parting surface line type. After finding the line type that satisfies the parting surface design rules in step 2, the parting surface line type is divided into the upper parting surface line type and the lower parting surface line type.

[0012] Furthermore, the parting surface line is divided into an upper parting surface line and a lower parting surface line by breaking it apart.

[0013] Furthermore, the universal joint inner hole is divided into four types: the first type includes an inner hole upper die bevel, an inner hole straight edge, and an inner hole lower die bevel; the second type includes an inner hole straight edge and an inner hole lower die line; the third type includes an inner hole upper die bevel and an inner hole straight edge; and the fourth type includes an inner hole straight edge.

[0014] Furthermore, the sorting algorithm in step 4 uses the mold line type on the parting surface and the mold line type on the lower parting surface as the starting line types for searching. It searches the bus line type set for line types that are connected to the mold line type on the parting surface and the mold line type on the lower parting surface, respectively. The line type connected to the mold line type on the parting surface is the upper mold line type, and the line type connected to the mold line type on the lower parting surface is the lower mold line type. After removing the connected line types from the bus line type set, it searches for the line types connected to them, using the connected line type as the starting line type for searching.

[0015] Furthermore, the sorting algorithm in step 4 connects the beginning and end of the line by making the starting point of the searched connected line equal to the ending point of the searched line. Connecting the beginning and end means that the ending point of one line connects to the starting point of another line.

[0016] Furthermore, if the starting point of the searched connected line is not the same as the ending point of the searched line, the starting and ending points of the searched connected line can be swapped to achieve a connection between the beginning and end of the line.

[0017] Furthermore, in step 5, the draft angle is designed based on the width-to-height ratio H / B of the forging.

[0018] Furthermore, the height H value of the forging is determined by comparing the starting point Y coordinate value and the ending point Y coordinate value of the draft line. By comparing the Y values, it is determined whether to search forward or backward in the set of non-horizontal lines, taking the position of the draft line in the set of upper or lower die lines as the starting point. The B value is calculated based on the coordinates of the non-horizontal lines and the coordinates of the draft line.

[0019] Furthermore, the forging is a rotating body structure.

[0020] Compared with the prior art, the beneficial effects of the present invention are: the present invention solves the problems of excessive reliance on designer experience in the design of draft angles for wheel hub forgings, large degree of variability in draft angle design, and low efficiency in drawing draft angles. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 This is a flowchart of the automated design method for the draft angle of wheel hub forgings according to the present invention;

[0023] Figure 2 This is a schematic diagram of the forging described in this invention;

[0024] Figure 3 The flowcharts for steps 1 and 2 of the automated design method for the draft angle of wheel hub forgings according to the present invention are shown below.

[0025] Figure 4 This is a flowchart of step 3 of the automated design method for the draft angle of wheel hub forgings according to the present invention;

[0026] Figure 5 This is a flowchart of step 4 of the automated design method for the draft angle of wheel hub forgings according to the present invention;

[0027] Figure 6 This is a flowchart of step 5 of the automated design method for the draft angle of wheel hub forgings according to the present invention;

[0028] Figure 7 This is a drawing of a wheel hub forging for an example.

[0029] Figure 8 This is a drawing of the wheel hub forging after mold separation, as shown in the embodiment.

[0030] Figure 9 This is a drawing of the wheel hub forging in the embodiment after draft angle.

[0031] 1-Centerline, 2-Left side line, 3-Model surface on parting surface, 4-Lower model surface on parting surface, 5-Inner hole upper mold bevel, 6-Inner hole straight edge, 7-Inner hole lower mold bevel, 8-Universal joint inner hole. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0033] See Figure 1-9 This embodiment describes a rotating wheel hub forging as the research object. Considering the rotational characteristics of the wheel hub forging, only one side of the forging's centerline in the CAD drawing needs to be considered. The other side can be symmetrically represented by the centerline in the CAD drawing. The forging has a universal joint inner hole 8. The dimensions of the forging are: H1 = 9mm, B1 = 7mm, H2 = 16mm, B2 = 13.73mm, H3 = 6.72mm, H4 = 11.72mm, H5 = 5mm, B3 = 8mm, H6 = 14mm, B4 = 7.88mm, H7 = 2.25mm, H8 = 9.25mm, B5 = 4mm, H9 = 10mm, B6 = 5mm, H10 = 30mm, and B7 = 9mm. The linearity of the guide die draft angle for the forging is from H1 to H10. An automated design method for a wheel hub forging is provided, which includes the following steps:

[0034] Step 1: Extract Figure 7 The left side line 2 of the center line 1 of the middle wheel hub forging is placed in the collection leftObjectId. The other side line can be completed symmetrically using the center line after the design is completed. The collection topLeftId is declared to store the upper mold line, bottomLeftId to store the lower mold line, and leftInnerId to store the inner hole line.

[0035] Step 2: In the design of the wheel hub forging, the selection rule for the parting surface is set to the area with the largest projected area of ​​the forging, and the center parting surface is used. According to the above rule, the line type is filtered, and the vertical line with the smallest abscissa in the leftObjectId set is selected. This vertical line is the parting surface, that is... Figure 7 In the H5 section, according to the center-partitioning rule, the line type is broken, thus dividing H5 into H11 and H12, as follows. Figure 8As shown in the diagram. H11 is the mold line type 3 on the parting surface with a length of 7mm, stored in the collection topLeftId. H12 is the mold line type 4 on the lower parting surface with a length of 7mm, stored in the collection bottomLeftId. H5 is removed from the collection leftObjectId. The flowcharts for steps 1 and 2 above are shown in the diagram. Figure 3 As shown;

[0036] Step 3: There are four types of inner hole 8 in the universal joint of the wheel hub forging. The type can be determined by the number of points in the innerLeftPoint3d set and the Boolean variable isTop. When the number of points in the innerLeftPoint3d set is 4, the inner hole is type A1. Based on the coordinate points, find the upper die inclined side 5, the straight side 6, and the lower die inclined side 7 of the inner hole from the leftObjectId set, and add the line type to the leftInnerId set accordingly. When the number of points in the innerLeftPoint3d set is 3 and isTop is false, the inner hole is type A2. Based on the coordinate points, find the straight side 6 and the lower die inclined side 7 of the inner hole from the leftObjectId set, and add the line type to the leftInnerId set accordingly. In the `erId` set; when the number of points in the `innerLeftPoint3d` set is 3 and `isTop` is true, the inner hole is type A3. Based on the coordinate points, find the upper mold hypotenuse 5 and the inner hole straight edge 6 from the `leftObjectId` set, and add the line type to the `leftInnerId` set accordingly. When the number of points in the `innerLeftPoint3d` set is 2, the inner hole is type A4. Based on the coordinate points, find the inner hole straight edge 6 from the `leftObjectId` set, and add the line type to the `leftInnerId` set. Input the coordinate point set `innerLeftPoint3d` of the universal joint inner hole 8 and the boolean variable `isTop`. At this time, the coordinates of the inner hole points are C and D. The inner hole has no hypotenuse, so `isTop` is false. The algorithm process is as follows: Figure 4 As shown, the inner hole of the forging is of type A4. Based on the coordinate point, the straight edge 6 of the inner hole is found from the set leftObjectId. The line type is added to the set leftInnerId, and then the line type in the set leftInnerId is removed from the set leftObjectId.

[0037] Step 4: Filter and sort the upper mold lines in `leftObjectId` so that they are arranged in the `topLeftId` set in a head-to-tail order. The sorting algorithm used is as follows: Figure 5As shown, the `topLeftId` set is iterated over. Initially, the `topLeftId` set only contains the newly added mold line type 3 on the parting surface. By iterating over the line types in the `leftObjectId` set, a line type that matches the endpoint of mold line type 3 on the parting surface is searched. If a match is found, it is further checked whether the starting point of the searched `leftObjectId[j]` is equal to the endpoint of the upper mold line type on the parting surface. If they are equal, the matched `leftObjectId[j]` is added to `topLeftId` and `leftObjectId[j]` is removed from `leftObject`. If they are not equal, the start and end points of leftObjectId[j] are swapped, then added to topLeftId and removed from leftObject. At this time, the size of the topLeftId set becomes 2, and i is 1, so the loop continues. This loop continues until all the mold line types 3 on the parting surface are found and stored in the set topLeftId in a connected order, and then the loop is broken. The same algorithm is used to filter and sort the lower mold line types 4 on the lower parting surface in leftObjectId so that the lower mold line types are arranged in the set bottomLeftId in a connected order.

[0038] Step 5: Considering the aspect ratio, design the draft angle of the forging. The draft angle design rules are shown in Table 1, and the algorithm process is as follows: Figure 6 As shown, the topLeftId set is looped through to find line types that are perpendicular. It is then determined whether the starting Y-coordinate of the line type topLeftId[i] is greater than its ending Y-coordinate. If it is greater, similar to H in the figure... R H at this time R The value of B is equal to the starting Y-coordinate of topLeftId[i] minus the ending Y-coordinate. To calculate the B value, we need to start from H. R The search proceeds forward to find a non-horizontal line type, which means searching forward from position i-1 in the set topLeftId to find topLeftId[j] that is not horizontal. At this point, B equals the X-coordinate of the starting point of the guide draft angle line type topLeftId[i] minus the X-coordinate of the ending point of the searched topLeftId[j]. When the Y-coordinate of the starting point of the line type topLeftId[i] is less than the Y-coordinate of its ending point, it is similar to H in the figure. L H at this time L The value of B is equal to the Y-coordinate of the endpoint of topLeftId[i] minus the Y-coordinate of its starting point. To calculate the B value, we need to start from H. LThe search proceeds backward to find the non-horizontal topLeftId[k]. B is equal to the X-coordinate of the starting point of the found topLeftId[k] minus the X-coordinate of the ending point of the desired draft angle line topLeftId[i]. Then, the draft angle is selected and derived according to the draft angle H / B rule. The lower die line also uses this algorithm to calculate and derive the draft angle H / B. The range of H / B values ​​is shown in the table below.

[0039] Table 1

[0040] H / B ≤1 >1-3 >3-4.5 >4.5-6.5 >6.5 Draft angle 5° 7° 10° 12° 15°

[0041] According to the above algorithm, the draft angle of H1 is determined by H1 / B1, with a ratio of 1.29 and a draft angle of 7°. The draft angle of H2 is determined by H2 / B1, with a ratio of 2.29 and a draft angle of 7°. The draft angles of the remaining line types are as follows: H3 is 5°, H4 is 5°, H5 is 5°, H11 is 5°, H12 is 5°, H7 is 5°, H8 is 7°, H9 is 7°, and H10 is 10°. Finally, by symmetry along centerline 1, the left line type is symmetrically transferred to the right, thus completing the draft angle design of the forging. The forging with the draft angles completed is shown below. Figure 9 As shown.

[0042] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. An automated design method for the draft angle of a wheel hub forging, characterized in that: The forging has a universal joint inner hole (8). The method includes the following steps: Step 1: Identify all line types on one side of the centerline of the forging and put them into a single bus line type set; Step 2: Find the parting surface line type according to the parting surface design rules and perform parting, then remove the line type from the bus line type set; Step 3: Based on the set of coordinate points of the inner hole (8) of the universal joint of the wheel hub forging, determine the inner hole form, find the inner hole line type, and remove the line type from the bus line type set; Step 4: Distinguish between upper and lower dies in the bus type set. Store all upper die line types in the defined upper die line type set by connecting the first and last lines according to the sorting algorithm. Store all lower die line types in the lower die line type set by connecting the first and last lines. Step 5: Design the draft angle of the upper and lower die line sets that need to be drafted according to the design rules of the draft angle. Then, symmetrically transfer the line set on one side to the other side through the center line (1) to complete the draft angle of the forging. The parting surface line type includes the parting surface upper mold line type (3) and the parting surface lower mold line type (4). After finding the line type that meets the parting surface design rules in step 2, the parting surface line type is divided into the parting surface upper mold line type (3) and the parting surface lower mold line type (4). The sorting algorithm in step 4 is to use the parting surface upper mold line type (3) and the parting surface lower mold line type (4) as the starting line type for searching. The line type connected to the parting surface upper mold line type (3) and the parting surface lower mold line type (4) is searched in the bus type set. The line type connected to the parting surface upper mold line type (3) and the parting surface lower mold line type (4) are respectively. The line type connected to the parting surface upper mold line type (3) is the upper mold line type, and the line type connected to the parting surface lower mold line type (4) is the lower mold line type. After removing the connected line type from the bus type set, the line type connected to it is searched using the connected line type as the starting line type for searching. Step 5 involves designing the draft angle based on the width-to-height ratio H / B of the forging. The height H of the forging is determined by comparing the starting point Y-coordinate value and the ending point Y-coordinate value of the draft line. By comparing the Y values, the position of the draft line in the set of upper or lower die lines is used as the starting point. Lines that are not horizontal are searched forward or backward in the set. The B value is calculated based on the coordinates of the non-horizontal lines and the coordinates of the draft line.

2. The automated design method for draft angle of wheel hub forgings according to claim 1, characterized in that: The parting surface line is divided into upper parting surface line (3) and lower parting surface line (4) by breaking it.

3. The automated design method for draft angle of wheel hub forgings according to claim 1, characterized in that: The universal joint inner hole (8) is divided into four types. The first type of inner hole includes the inner hole upper die bevel (5), the inner hole straight edge (6) and the inner hole lower die bevel (7). The second type of inner hole includes the inner hole straight edge (6) and the inner hole lower die bevel (7). The third type of inner hole includes the inner hole upper die bevel (5) and the inner hole straight edge (6). The fourth type of inner hole includes the inner hole straight edge (6).

4. The automated design method for draft angle of wheel hub forgings according to claim 1, characterized in that: The sorting algorithm in step 4 connects the beginning and end of the line by making the starting point of the searched connected line equal to the ending point of the searched line. Connecting the beginning and end means that the ending point of one line connects to the starting point of another line.

5. The automated design method for draft angle of wheel hub forgings according to claim 4, characterized in that: If the starting point of the searched connected line is not the same as the ending point of the searched line, swap the starting and ending points of the searched connected line to achieve a connection between the beginning and end of the line.

6. The automated design method for draft angle of wheel hub forgings according to claim 1, characterized in that: The forging has a rotating body structure.

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