Method for designing lightening holes of mold bottom plate casting

Abstract

The invention relates to a mold bottom plate casting lightening hole design method which comprises the following steps: selecting the bottom surface of a casting bottom plate according to an interactive interface to obtain a part entity, finding out all casting planes (rib surfaces) in the entity, and obtaining the direction, size and central point of each rib surface and the other surface of the rib surface; judging whether a series of conditions such as whether the surface has an arc, whether the rib is a broken rib and whether the thickness of the rib meet requirements; the surfaces which do not meet the requirements are filtered out, the surfaces which meet the requirements are left, and lightening holes are designed according to the standard; and finally, the automatic design of the lightening hole is realized. The casting lightening hole can be automatically generated only by selecting one entity target in the whole process. Standardized and automatic design of the casting lightening hole can be achieved, the workload of lightening hole design is reduced, and the design period is shortened. Compared with manual design, the time is shortened by about 95%, the process can be completed by operating a program for 2 minutes, repeated labor is reduced, and the design standardization of casting lightening holes is improved.

Description

Technical Field

[0001] The invention relates to an automobile stamping die, and in particular to a method for designing a lightening hole of a die bottom plate casting. Background Art

[0002] The stamping of automotive panels is inseparable from the mold, which is an essential tooling for stamping parts. The most time-consuming part of mold design is the casting design, including the design of large castings such as the upper base plate, lower base plate, binder ring, and ejector, which accounts for more than 60% of the entire mold design workload. In order to reduce the weight of the casting, we usually need to design lightening holes on the ribs to reduce the mold weight. The quality of the lightening hole design directly affects the quality of the entire mold casting and the design cycle.

[0003] The following problems exist in the design of casting lightening holes:

[0004] 1. It takes a long time: A set of large molds has 200-400 lightening holes on the upper and lower base plates. If it is designed manually, it will take one day. It can be said that the casting design and lightening hole design take up a lot of design time;

[0005] 2. The design of lightening holes needs to meet certain requirements and must comply with design standards. For new designs, it is necessary to query the design standards, which takes up design time. In addition, different understandings of the standards may lead to errors that do not conform to the design standards.

[0006] 3. At present, some domestic companies have developed lightening hole design tools, which require selecting surfaces one by one and inputting parameters to generate lightening holes. The efficiency has been improved to a certain extent, but the workload is still a bit high, and it takes hundreds of selections to complete.

[0007] At present, the design of lightening holes in domestic castings basically remains at the manual design stage. Summary of the Invention

[0008] In order to solve the above problems, the present invention provides a method for designing lightening holes of mold bottom plate castings, which can realize the one-time completion of the lightening holes of castings, effectively reduce the working time and labor intensity of designers, and improve work efficiency.

[0009] The technical solution adopted by the present invention is: a method for designing a lightening hole for a mold bottom plate casting, characterized in that it includes the following steps:

[0010] S1. Select the bottom plane of the casting

[0011] Get the maximum closed contour line, bottom surface direction, center point, and create a reference plane;

[0012] S2. Get all the bottom plane parameters of the casting

[0013] Get the entity by selecting the bottom plane, query and obtain the target and number of all faces in the entity, and obtain the geometric parameters of each face and its adjacent faces;

[0014] S3. Surface filtering

[0015] Through judgment, all faces that do not meet the requirements for lightening holes are filtered out, and faces that meet the requirements are retained;

[0016] S4. Get the parameters of the other side of the rib and filter again

[0017] Filter out all faces that do not meet the requirements for lightening holes and retain faces that meet the requirements;

[0018] S5. Design lightening holes on ribs that meet the requirements

[0019] Lightening holes of different types and sizes are designed through the geometric characteristic parameters of the plane.

[0020] Preferably, the specific steps of S1 are: obtain the bottom direction vector DIR, obtain the bottom center point CPT, create a bottom reference plane DP based on the bottom center point CPT and the bottom direction vector DIR, and determine whether the bottom plate is an upper bottom plate or a lower bottom plate based on the bottom direction vector DIR: if the bottom direction vector DIR is the same as the Z-axis direction, it is determined to be an upper bottom plate, otherwise it is a lower bottom plate; calculate the maximum contour line CLOSE_EDGE of the bottom surface.

[0021] Preferably, in step S2, the casting surface parameters include the size, direction, color, contour line and center point of the surface.

[0022] Preferably, in step S3, the specific determination method is:

[0023] S31. Determine the type and direction of each surface: filter out surfaces other than the plane; determine whether the plane direction is perpendicular to the Z-axis direction, and retain the plane perpendicular to the Z-axis direction;

[0024] S32, determining whether the plane is connected to the bottom surface and whether it is connected to the maximum contour line of the bottom surface: filtering out planes that are not connected to the bottom surface, filtering out planes that are connected to the maximum contour line of the bottom surface, and filtering out processing planes;

[0025] S33, determining whether there are any lightening holes on the plane: filtering out faces with lightening holes on the plane;

[0026] S34. Determine the width of the plane and whether it meets the conditions for drilling: filter out surfaces with a width greater than 500 mm and a length less than 220 mm;

[0027] S35. Determine whether the minimum height of the plane meets the punching conditions: find all lines in the plane, exclude the bottom edge line and the lines perpendicular to the bottom edge; if the remaining horizontal straight line is less than 220 mm from the bottom edge, filter out this plane;

[0028] S36. Determine whether it is a broken surface and filter out broken surfaces PLANE: First, find the adjacent surfaces to the surface to be determined. If there are four adjacent surfaces, perform the following determination: Use plane PLANE as a reference plane and move 2 mm in the normal direction to generate a reference plane DATUM. Determine the distance between the four adjacent surfaces PLANE1, PLANE2, PLANE3, and PLANE4 and this surface PLANE. If the distance is greater than 0.1 mm, determine it as a broken surface and filter it out.

[0029] S37. Determine the thickness of the reinforcement: Use the ray method to draw rays in the opposite direction of the surface to obtain the thickness of the reinforcement; when the thickness of the reinforcement is greater than 51mm, filter it out.

[0030] As a preferred embodiment, the specific steps of S4 are: find the center point CPT of the surface and make a reverse ray of the surface to find the other side of the rib and the projection point PROJ_PT, find the closed contour line CLOSEEDGE of the other side, query the minimum distance from the projection point PROJ_PT to the closed contour line CLOSEEDGE, and filter it out if it is less than 80mm; at the same time, the other side cannot be a machining surface.

[0031] Preferably, the specific step of S5 is: calculating the distance L between the center point CPT of the plane and the bottom surface of the base plate, and determining whether it is a circular lightening hole or a rectangular lightening hole according to the distance L.

[0032] As a preference, first of all, L must be greater than 220 mm. If L is less than 300 mm, it is a round lightening hole; if L is greater than 300 mm, it is a rectangular lightening hole.

[0033] The beneficial effects achieved by the present invention are as follows: according to the interactive interface, the method selects the bottom surface of the casting base plate to obtain the part entity, finds all the casting planes (rib surfaces) in the entity, obtains the direction, size and center point of each rib surface, and the other side of the rib surface; judges whether a series of conditions such as whether there is a circular arc on the surface, whether the rib is a broken rib and the thickness of the rib meet the requirements; the surfaces that do not meet the requirements are filtered out, and the remaining surfaces that meet the requirements are then designed according to the standards for circular lightening holes and rectangular lightening holes; finally, the automated design of casting lightening holes is achieved. The entire process only requires selecting an entity target to automatically generate casting lightening holes. The present invention can achieve standardized and automated design of casting lightening holes, reduce the workload of casting lightening hole design, and shorten the design cycle. Compared with manual design, the present invention shortens the time by about 95%, and can be completed in 2 minutes by running the program, reducing repetitive work, greatly shortening the design time of casting lightening holes, reducing casting lightening hole design errors, and improving the standardization of casting lightening hole design. The present invention has the following advantages:

[0034] 1. Complete the design of all the lightening holes of the base plate castings with one click. The original lightening hole design needed to be designed one by one, but now hundreds of lightening holes of castings can be designed at once.

[0035] 2. Automatically select the type and size of the lightening hole, automatically judge based on the surface and surrounding surface, automatically select circular lightening holes and rectangular lightening holes, and automatically judge the size of the lightening hole;

[0036] 3. A variety of surface judgment methods are proposed. In addition to conventional judgments (surface size, direction, type, color), methods such as surface position, adjacent surface geometric features, rib thickness, broken surface, whether there is an arc on the surface, and whether the other side of the selected surface also meets the requirements are proposed to filter and obtain the required punching surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram for determining the bottom plane of the casting entity;

[0038] Figure 2 A schematic diagram for determining the plane type;

[0039] Figure 3 A schematic diagram for determining whether a plane is connected to the bottom surface and whether it is connected to the maximum contour line of the bottom surface;

[0040] Figure 4 A schematic diagram for determining whether there are lightening holes on a plane;

[0041] Figure 5 A schematic diagram showing whether the plane width meets the punching conditions;

[0042] Figure 6 A schematic diagram showing whether the minimum height of a plane satisfies the drilling conditions;

[0043] Figure 7 A schematic diagram for determining whether it is a broken end surface;

[0044] Figure 8 A schematic diagram for determining the thickness of the ribs;

[0045] Figure 9 A schematic diagram for obtaining the other side of the tendon for judgment;

[0046] Figure 10 Schematic diagram for determining the type and size of lightening holes. DETAILED DESCRIPTION

[0047] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0048] The present invention provides a method for designing a lightening hole for a mold bottom plate casting, which is characterized by comprising the following steps:

[0049] S1. Select the bottom plane of the casting

[0050] Get the maximum closed contour line, bottom surface direction, center point, and create a reference plane;

[0051] Combine Figure 1 As shown, obtain the bottom surface direction vector DIR, obtain the bottom surface center point CPT, create the bottom surface reference plane DP according to the bottom surface center point CPT and the bottom surface direction vector DIR, and determine whether the bottom plate is the upper bottom plate or the lower bottom plate according to the bottom surface direction vector DIR: if the bottom surface direction vector DIR is in the same direction as the Z axis, it is determined to be the upper bottom plate, otherwise it is the lower bottom plate; calculate the bottom surface maximum contour line CLOSE_EDGE; the upper and lower bottom plates are used to determine the upper and lower positions of the user's lightening holes;

[0052] S2. Get all the bottom plane parameters of the casting

[0053] Obtain the entity by selecting the bottom plane, query and obtain the target and number of all faces in the entity, and obtain the geometric parameters of each face and its adjacent faces; casting surface parameters include face size, direction, color (such as casting surface color number #137, machined surface color: red #186, blue #211, yellow #6), outline and center point;

[0054] S3. Surface filtering

[0055] Through judgment, all faces that do not meet the requirements for lightening holes are filtered out, and faces that meet the requirements are retained;

[0056] The specific judgment and filtering methods for faces are:

[0057] S31, determine the type and direction of each face (combined with Figure 2 (as shown): Filter out all surfaces except planes (including cylindrical surfaces, conical surfaces, curved surfaces, etc.); determine whether the plane direction is perpendicular to the Z axis direction, and retain the plane perpendicular to the Z axis direction;

[0058] S32, determine whether the plane is connected to the bottom surface and whether it is connected to the maximum contour line of the bottom surface (combined with Figure 3 (as shown): filter out the planes that are not connected to the bottom surface, filter out the planes that are connected to the maximum contour line of the bottom surface, and filter out the processing planes;

[0059] S33, determine whether there is a lightening hole on the plane (combined with Figure 4 (as shown): Filter out the faces with lightening holes in the plane; the radius of the lightening holes is usually R30, R40, R50, that is, the faces with holes cannot have lightening holes;

[0060] S34, judge the width of the plane and determine whether the conditions for punching are met (combined with Figure 5 Filter out faces with a width greater than 500 mm and a length less than 220 mm.

[0061] S35, determine whether the minimum height of the plane meets the conditions for drilling (combined with Figure 6 (as shown): Find all lines in the plane, excluding the bottom edge and the lines perpendicular to the bottom edge; if the remaining horizontal lines are less than 220mm from the bottom edge, filter out this plane;

[0062] S36, determine whether it is a broken surface, filter out the broken surface PLANE (combined with Figure 7 First, find the adjacent faces to the face to be judged. If there are four adjacent faces, perform the following judgment: use this plane PLANE as the reference plane, move 2mm in the normal direction, generate the reference plane DATUM, and judge the distance between the four adjacent faces PLANE1, PLANE2, PLANE3 and PLANE4 and this face PLANE. If the distance is greater than 0.1mm, it is judged as a broken face and filtered out;

[0063] S37, determine the thickness of the ribs (combined with Figure 8 As shown in the figure): Use the ray method to draw rays in the opposite direction of the surface to obtain the thickness of the ribs; if the rib thickness is greater than 51 mm, filter it out.

[0064] S4. Get the parameters of the other side of the rib and filter again

[0065] Filter out all faces that do not meet the requirements for lightening holes and retain faces that meet the requirements; Combine Figure 9As shown, find the center point CPT of the surface and make a reverse ray to find the other side of the rib and the projection point PROJ_PT. Find the closed contour line CLOSEEDGE of the other side and query the minimum distance from the projection point PROJ_PT to the closed contour line CLOSEEDGE. If it is less than 80mm, filter it out. At the same time, the other side cannot be a machining surface.

[0066] S5. Design lightening holes on ribs that meet the requirements

[0067] Design lightening holes of different types and sizes through the geometric characteristic parameters of the plane;

[0068] Combine Figure 10 As shown, the distance L between the center point CPT of the plane and the bottom surface of the base plate is calculated, and the lightening hole is determined to be a circular lightening hole or a rectangular lightening hole according to the distance L;

[0069] First of all, L must be greater than 220mm. If L is less than 300mm, it is a round lightening hole; if L is greater than 300mm, it is a rectangular lightening hole.

[0070] It should be noted that the description of the above technical solutions is illustrative only. This specification may be embodied in various forms and should not be construed as limiting the technical solutions set forth herein. Rather, these descriptions are provided to ensure that the disclosure of the present invention is thorough and complete and to fully convey the scope of the disclosure to those skilled in the art. Furthermore, the technical solutions of the present invention are limited only by the scope of the claims.

[0071] Finally, it should be noted that the above embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and is susceptible to numerous variations. Any simple modifications, equivalent variations, and modifications to the above embodiments based on the technical essence of the present invention shall be deemed to fall within the scope of protection of the present invention.

Claims

1. A method for designing lightening holes in a mold base casting, characterized by: The following steps are involved: S1. Select the bottom plane of the casting Get the maximum closed contour line, bottom surface direction, center point, and create a reference plane; S2. Get all the bottom plane parameters of the casting Get the entity by selecting the bottom plane, query and obtain the target and number of all faces in the entity, and obtain the geometric parameters of each face and its adjacent faces; S3. Surface filtering Through judgment, all faces that do not meet the requirements for lightening holes are filtered out, and faces that meet the requirements are retained; S4. Get the parameters of the other side of the rib and filter again Filter out all faces that do not meet the requirements for lightening holes and retain faces that meet the requirements; S5. Design lightening holes on ribs that meet the requirements Lightening holes of different types and sizes are designed through the geometric characteristic parameters of the plane.

2. The method for designing lightening holes for mold bottom plate castings according to claim 1, characterized in that: The specific steps of S1 are: obtain the bottom surface direction vector DIR, obtain the bottom surface center point CPT, create the bottom surface reference plane DP according to the bottom surface center point CPT and the bottom surface direction vector DIR, and determine whether the bottom plate is the upper bottom plate or the lower bottom plate according to the bottom surface direction vector DIR: if the bottom surface direction vector DIR is the same as the Z-axis direction, it is determined to be the upper bottom plate, otherwise it is the lower bottom plate; calculate the maximum contour line CLOSE_EDGE of the bottom surface.

3. The method for designing lightening holes for mold bottom plate castings according to claim 1, characterized in that: In step S2, the casting surface parameters include the size, direction, color, outline and center point of the surface.

4. The method for designing lightening holes in a mold bottom plate casting according to claim 1, wherein: In step S3, the specific judgment method is: S31. Determine the type and direction of each surface: filter out surfaces other than the plane; determine whether the plane direction is perpendicular to the Z-axis direction, and retain the plane perpendicular to the Z-axis direction; S32, determining whether the plane is connected to the bottom surface and whether it is connected to the maximum contour line of the bottom surface: filtering out planes that are not connected to the bottom surface, filtering out planes that are connected to the maximum contour line of the bottom surface, and filtering out processing planes; S33, determining whether there are any lightening holes on the plane: filtering out faces with lightening holes on the plane; S34. Determine the width of the plane and whether it meets the conditions for drilling: filter out surfaces with a width greater than 500 mm and a length less than 220 mm; S35. Determine whether the minimum height of the plane meets the punching conditions: find all lines in the plane, exclude the bottom edge line and the lines perpendicular to the bottom edge; if the remaining horizontal straight line is less than 220 mm from the bottom edge, filter out this plane; S36. Determine whether it is a broken surface and filter out broken surfaces PLANE: First, find the adjacent surfaces to the surface to be determined. If there are four adjacent surfaces, perform the following determination: Use plane PLANE as a reference plane and move 2 mm in the normal direction to generate a reference plane DATUM. Determine the distance between the four adjacent surfaces PLANE1, PLANE2, PLANE3, and PLANE4 and this surface PLANE. If the distance is greater than 0.1 mm, determine it as a broken surface and filter it out. S37. Determine the thickness of the reinforcement: Use the ray method to draw rays in the opposite direction of the surface to obtain the thickness of the reinforcement; when the thickness of the reinforcement is greater than 51mm, filter it out.

5. The method for designing lightening holes in a mold bottom plate casting according to claim 1, characterized in that: The specific steps of S4 are: find the center point CPT of the surface and make a reverse ray of the surface to find the other side of the rib and the projection point PROJ_PT, find the closed contour line CLOSEEDGE of the other side, query the minimum distance from the projection point PROJ_PT to the closed contour line CLOSEEDGE, and filter out if it is less than 80mm; at the same time, the other side cannot be a machining surface.

6. The method for designing lightening holes in a mold bottom plate casting according to claim 1, characterized in that: The specific steps of S5 are: calculating the distance L between the center point CPT of the plane and the bottom surface of the base plate, and determining whether it is a circular lightening hole or a rectangular lightening hole according to the distance L.

7. The method for designing lightening holes in a mold bottom plate casting according to claim 6, characterized in that: First of all, L must be greater than 220mm. If L is less than 300mm, it is a round lightening hole; if L is greater than 300mm, it is a rectangular lightening hole.

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