Machining method for controlling tipping of cutting edge of stamping die

Abstract

The invention discloses a machining method for controlling tipping of a cutting edge of a stamping die, which relates to the field of stamping and comprises the following steps: detecting the hardness of the cutting edge of the die; an anti-tipping machining area is determined according to the contour line of the mold cutting edge; the anti-tipping machining area is machined from outside to inside through a ball head cutter; the area where anti-tipping machining is completed is subjected to overall semi-finishing machining, the step of detecting the hardness of the die cutting edge comprises the substep that a durometer is used for conducting multi-point detection at the position of the cutting edge, the distance between the detection points is 70-90 mm, and the hardness standard is set to be HRC50-60. According to the machining method, through the process sequence that the anti-tipping area is machined firstly and then overall semi-finishing is conducted, damage to the cutting edge caused by a follow-up program tool path is effectively avoided, the machining direction from outside to inside and reasonable cutting parameters are adopted, and the risk of tipping of the cutting edge is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mold processing, in particular to a processing method for controlling blade collapse of a stamping die. BACKGROUND

[0002] In the mold manufacturing process, the processing quality of the trimming blade directly determines the precision and appearance quality of the product contour, and is a key factor for controlling product qualification rate and good product rate. Since the trimming blade position is usually designed to be extremely sharp, it is easy to be damaged due to stress concentration or improper operation during CNC machining, EDM machining and subsequent debugging and die assembly. In actual production process, different types of damage forms such as small area notch, blade collapse, local collapse and even large blade shedding often occur under the existing technology. Such damage not only makes the mold have to be stopped for repair, seriously affecting the production progress, but also takes a long time in the repair process, has high technical requirements for the operator, and after repair, the blade shape or strength recovery is not ideal, which causes the product to have burrs, burrs, wire drawing and other quality problems during stamping or injection molding, and even causes uneven material cutting section.

[0003] The main reasons for these problems include: selecting inappropriate tool type, tool material or blade type during processing stage, the cutting parameters (such as speed, feed rate, cutting depth, etc.) are not matched with the material properties, the continuous impact or tool empty walking caused by unreasonable processing path design, and the processing difficulty caused by the hardness increase after heat treatment is not adjusted accordingly. Especially after the blade is heat treated such as quenching, the hardness of the material increases significantly (usually up to HRC50 or more), and the brittleness also increases. At this time, if the traditional processing technology and tool are still used, the blade will be damaged due to cutting vibration, thermal stress concentration or tool collapse. Therefore, it is an urgent need to improve the mold life and production stability by taking measures from the root cause, systematically optimizing the processing flow and parameters, and developing an improved method that can effectively control the blade integrity and prevent blade collapse under high hardness conditions. SUMMARY

[0004] The purpose of the present application is to solve the problems in the prior art and propose a processing method for controlling blade collapse of a stamping die.

[0005] The present application first discloses a processing method for controlling blade collapse of a stamping die, comprising the following steps: detecting the hardness of the die blade; determining the anti-blade collapse processing area according to the contour line of the die blade; using a ball nose tool to process the anti-blade collapse processing area from outside to inside; after the anti-blade collapse processing area is processed, the whole workpiece is semi-finished machined.

[0006] In the method, the hardness of the die edge is detected by using a hardness tester to detect multiple points on the edge position, and the distance between the detection points is 70-90 mm, wherein the hardness standard is set to be between HRC 50-60.

[0007] In the method, the anti-chipping processing area is determined by offsetting 4-6 mm to the outside of the profile and offsetting 9-11 mm to the inside of the profile based on the die edge profile line, and a closed processing boundary is formed.

[0008] In the method, the anti-chipping processing area is determined by offsetting 4-6 mm to the outside of the profile and offsetting 9-11 mm to the inside of the profile based on the die edge profile line, and a closed processing boundary is formed.

[0009] In the method, the processing from the outside to the inside includes moving the cutter from the outside to the inside of the processing area based on the edge profile line as a reference line.

[0010] In the method, the cutting parameters of the processing include a step distance of 0.7-0.9 mm, a cutting depth of not more than 0.3 mm, a rotation speed of 2800-3200 rpm, and a feed speed of 1700-1900 mmpm.

[0011] In the method, when the processing allowance exceeds 0.3 mm, a layered processing mode is adopted.

[0012] In a second aspect, the application also discloses a storage medium storing a computer program, which realizes the steps of the above method when executed by a processor.

[0013] The application has the following advantages: 1. By adopting the process sequence of first processing the anti-chipping area and then processing the overall semi-finishing, the step ensures that the vulnerable area is strengthened in the early stage of processing, thereby effectively avoiding mechanical damage to the edge caused by the subsequent tool path; the processing direction from the outside to the inside can gradually reduce the impact of cutting force on the edge, and in combination with reasonable cutting parameters such as appropriate feed speed, cutting depth and cooling liquid application, the risk of edge chipping is further reduced, and the stability of the processing process and the tool life are improved.

[0014] 2. The hardness detection ensures that the material is in a suitable processing state, and this measure includes using a Rockwell or Brinell hardness tester for regular inspection to confirm that the material hardness meets the processing requirements, thereby improving the processing quality and reducing defects caused by uneven material; the process can be applied to the processing of die edges of various complex shapes, such as curved surfaces, sharp corners or special-shaped structures, and has wide applicability, can meet the needs of diversified industrial production, and ensures the precision and durability of the final product. Attached Figure Description

[0015] Figure 1 This is a flowchart of a processing method for controlling the chipping of the cutting edge of a stamping die, as disclosed in this invention.

[0016] Figure 2 This is a schematic diagram of the anti-chipping processing area in a processing method for controlling chipping of the cutting edge of a stamping die disclosed in this invention.

[0017] Figure 3 This is a schematic diagram of the step-by-step machining method in a machining method for controlling the chipping of the cutting edge of a stamping die disclosed in this invention.

[0018] Figure 4 This is a schematic diagram of hardness detection in a processing method for controlling the chipping of the cutting edge of a stamping die disclosed in this invention. Detailed Implementation

[0019] To facilitate understanding of this application and to make the aforementioned objectives, features, and advantages of this application more apparent, a detailed description of specific embodiments of this application is provided below in conjunction with the accompanying drawings. Numerous specific details are set forth in the following description to provide a thorough understanding of this application, and preferred embodiments are shown in the accompanying drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application. This application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified. It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementations. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is only for describing particular implementations and is not intended to limit the scope of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] Reference Figures 1-4 A machining method for controlling the chipping of the cutting edge of a stamping die, comprising the following steps: Testing the hardness of the die cutting edge is a crucial step in die manufacturing and maintenance. Typically, a Rockwell hardness tester or Vickers hardness tester is used to perform multiple measurements at typical locations on the cutting edge and average the results. By testing the hardness of the cutting edge, its strength can be determined in advance, assessing whether it possesses sufficient resistance to deformation and wear. This prevents machining if the cutting edge hardness does not meet processing standards, avoiding chipping and further improving the die's service life and reliability.

[0021] The anti-chipping machining area is determined based on the contour line of the die cutting edge. This area generally extends outwards uniformly along the edge contour by a certain width. The purpose of determining the anti-chipping machining area is to set a buffer machining zone with a certain allowance on both sides of the machining point of the cutting edge. Within this machining area, the cutting amount and cutting stress of each cut are controlled by gradually machining and layered cutting. Compared with the one-step machining method in the prior art, this strategy can effectively distribute the machining load and avoid over-machining of a single part, which can cause small-area chipping, edge collapse, or large-area detachment damage, thereby improving machining safety and cutting edge quality.

[0022] The anti-chipping area is machined from the outside in using a ball-end milling cutter. The tool path should transition smoothly, avoiding sharp turns or entry / exit impacts. A single ball end mill is used to ensure a smooth machined surface, uniform stress distribution, and reduced stress concentration caused by the tool shape.

[0023] After semi-finishing the area where anti-chipping machining has been completed, the entire workpiece needs to be semi-finished to eliminate any uneven allowances left from the previous process and adjust geometric deviations. This ensures the geometric coordination between the cutting edge area and the overall mold, preventing local overcutting, vibration, or impact caused by unreasonable toolpath design or uneven allowance distribution in subsequent programs, thus preventing chipping of the cutting edge.

[0024] In one feasible embodiment, such as Figure 4 As shown, a Leeb hardness tester is used to test the hardness of the die's cutting edge. A test point is set every 80mm along the cutting edge contour. This spacing ensures representativeness while avoiding excessive density that could affect efficiency. Each test point requires three measurements, and the average value is taken to ensure the cutting edge hardness is within the HRC 55-60 range. If the hardness of a test point does not meet the requirements, the area must undergo local heat treatment again, and the test must be repeated until it meets the standard. The purpose of this testing process is to confirm whether the cutting edge hardness meets the processing requirements before machining, thereby avoiding chipping problems caused by excessively high or low cutting edge hardness during direct machining.

[0025] In one feasible embodiment, such as Figure 3 As shown, the anti-chipping machining area is determined. Taking the cutting edge contour line as a reference, and comprehensively considering stress distribution and machining safety margin, it is offset 5mm outward from the contour and 10mm inward from the contour to form a closed annular machining area. This area is a pre-treatment area specifically designed for anti-chipping machining, and its asymmetrical offset takes into account that the inner material is usually more prone to stress concentration.

[0026] In one feasible embodiment, the anti-chipping program is set using a CNC machine tool. A Φ30mm single-edged ball end mill is selected, as it has moderate rigidity and is suitable for machining curved surfaces. The cutting edge contour line is used as the toolpath reference line. The machining direction is set from the outside in, meaning the tool starts from the outer edge of the machining area and gradually moves inward using a helical or offset feed method. This feed path effectively reduces direct impact of the tool on the cutting edge. Combined with the closed-loop machining area boundary, this provides a buffer zone for absorbing vibration during the cutting process, further protecting the cutting edge.

[0027] In one feasible embodiment, the toolpath parameters can be set as follows: the tool pitch is set to 0.8 mm to balance machining efficiency and surface quality; the depth of cut is controlled within 0.3 mm, which falls into the micro-cutting category and greatly reduces cutting force. If the machining allowance exceeds 0.3 mm, a layered machining method is adopted, with the depth of each layer decreasing progressively. The spindle speed is set to 3000 rpm, and the feed rate is set to 1800 mmpm. This combination ensures smooth cutting while avoiding tool chatter.

[0028] After machining the anti-chipping area, the entire mold is then semi-finished. This step-by-step machining strategy separates high-risk areas from general areas, effectively preventing damage to the cutting edge caused by vibration or sudden changes in cutting force during subsequent machining.

[0029] In another embodiment, machining parameters can be adjusted appropriately for molds of different sizes. For small molds (cutting edge length < 500mm), a Φ20mm ball end mill can be used, with the step distance reduced to 0.5mm and the depth of cut adjusted to 0.2mm. For large molds (cutting edge length > 1500mm), a Φ40mm ball end mill can be used, with the step distance increased to 1.0mm, and the depth of cut maintained at 0.3mm. The spindle speed and feed rate are adjusted accordingly based on the tool size and machine tool power, but the machining direction from the outside in and the principle of layered machining are always maintained to ensure process consistency.

[0030] In one feasible embodiment, when the machining allowance exceeds 0.3mm, a layered machining method must be adopted, that is, the machining depth of each layer shall not exceed 0.3mm, and the material shall be removed layer by layer until the target size is reached. Chips must be cleaned between layers to avoid secondary cutting.

[0031] When machining special materials, cutting parameters need to be further optimized. For example, for high-hardness materials (HRC58-62), the spindle speed should be appropriately reduced to 2500 rpm and the feed rate to 1500 mmpm to reduce cutting impact. At the same time, the number of layers in the machining process should be increased to ensure that the depth of cut in a single pass does not exceed 0.2 mm. If necessary, compressed air cooling can be used to control the temperature rise and maintain tool sharpness and process stability.

[0032] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative and not exhaustive. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. A machining method for controlling the chipping of the cutting edge of a stamping die, characterized in that, Includes the following steps: Test the hardness of the die cutting edge; The anti-chipping processing area is determined based on the contour line of the die cutting edge; The anti-chipping edge processing area is machined from the outside in using a ball-end cutter. After semi-finishing the area where anti-chipping machining has been completed, the entire workpiece is semi-finished.

2. The processing method for controlling the chipping of the cutting edge of a stamping die according to claim 1, characterized in that: The hardness of the mold cutting edge is tested by using a hardness tester to perform multi-point testing at the cutting edge position, with a test point spacing of 70~90mm, and the hardness standard is set between HRC50~60.

3. The processing method for controlling the chipping of the cutting edge of a stamping die according to claim 1, characterized in that: The method for determining the anti-chipping processing area includes: taking the mold cutting edge contour line as a reference, offsetting 4~6mm outward from the contour and 9~11mm inward from the contour to form a closed processing boundary.

4. The processing method for controlling the chipping of the cutting edge of a stamping die according to claim 1, characterized in that: The ball end mill is a single-edged ball end mill with a diameter of 28~32mm.

5. The processing method for controlling the chipping of the cutting edge of a stamping die according to claim 1, characterized in that: The machining process from the outside in includes: using the cutting edge contour line as a reference line, moving the cutting tool from the outside of the machining area to the inside.

6. The processing method for controlling the chipping of the cutting edge of a stamping die according to claim 1, characterized in that: The cutting parameters for the machining process include: step distance 0.7~0.9mm, cutting depth not greater than 0.3mm, rotational speed 2800~3200rpm, and feed rate 1700~1900mmpm.

7. The processing method for controlling the chipping of the cutting edge of a stamping die according to claim 6, characterized in that: When the machining allowance exceeds 0.3mm, a layered machining method is adopted.

8. A storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 7.

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