Machine difference compensation method for die surface repair-free

Abstract

The invention relates to the technical field of dies, in particular to a die surface repair-free machine difference compensation method. Comprising the following steps that S1, rigidity and parallelism measurement is conducted on press machines of a mold manufacturing plant and a mold using plant; s2, punching simulation is carried out in combination with the data obtained in the step S1, the working conditions of the die on different press machines are simulated, and the sizes of the needed machine difference compensation cushion blocks are calculated respectively; and S3, manufacturing a machine difference compensation cushion block with a corresponding size, and meanwhile, machining a mounting groove for mounting the machine difference compensation cushion block on a die holder of the die. Compared with the prior art, closing precision errors caused by different mechanical characteristics of the press are eliminated, the grinding-in rate is improved, the development period of stamping parts is effectively shortened, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of molds, and specifically to a machine difference compensation method for avoiding die surface repair. Background Art

[0002] In the modern automotive industry, market competition is becoming increasingly fierce. Automotive manufacturing enterprises are constantly accelerating the R & D speed of new vehicle models in order to occupy a larger share in the rapidly changing market. Automotive parts, especially stamping parts, account for more than 60% of the vehicle's parts and occupy more than half of the vehicle development cycle. Therefore, how to effectively shorten the development cycle of stamping parts and improve their production efficiency has become a key issue in automotive supply chain management.

[0003] Currently, a major challenge in stamping die development lies in the precision adjustment during the first trial die of the die. Due to mechanical differences in the design, manufacturing, and assembly processes of different types of presses, such as stiffness, parallelism, etc., when the same set of dies is used with different presses, significant differences occur in the die closing precision, lapping method, and effect. This has a direct impact on the forming quality of stamping parts and is one of the main reasons for problems such as uneven part thickness, cracking, wrinkling, and inaccurate part dimensions, resulting in the quality of the produced stamping parts being difficult to meet the requirements of vehicle production.

[0004] In actual production, outer covering parts (such as car doors, hoods, etc.) have extremely high requirements for surface quality, and the lapping rate needs to reach more than 90%, while the lapping rate of internal structural parts can be slightly reduced, roughly around 80%. To achieve this lapping rate, traditional methods rely on experienced fitters for manual grinding and debugging. However, this process is not only time-consuming and laborious but also has great uncertainty.

[0005] In addition, the die debugging environment also changes after the die is delivered. The presses used for die trial and mass production are often different, and the environments and usage conditions also vary, so adjustments still need to be made after the die is transferred. This situation causes the die to face the problem of poor closing precision when put into production, affecting the die delivery cycle and further affecting the progress and quality of vehicle production.

[0006] Therefore, in view of the problems of poor closing precision, low lapping rate, cumbersome and time-consuming debugging process, etc. existing in the above stamping die development and trial die processes, a new solution needs to be sought to improve the reliability and production efficiency of stamping dies. Summary of the Invention

[0007] To overcome the deficiencies of the prior art, the present invention provides a machine difference compensation method without die surface repair, which solves the problems of poor die closing accuracy and low lapping rate caused by the mechanical characteristics of different presses, reduces the time for die transfer to the production line for debugging, improves the quality of stamping parts, and thus meets the requirements of the modern automotive industry for rapid development and high-quality production.

[0008] To achieve the above object, a machine difference compensation method without die surface repair is designed, including the following steps: S1. Measure the stiffness and parallelism of the presses in the die manufacturing factory and the die using factory respectively. S2. Combine the data obtained in step S1, conduct stamping simulation, simulate the working conditions of the die on different presses, and calculate the sizes of the required machine difference compensation pads respectively. S3. Manufacture the machine difference compensation pads with corresponding sizes, and at the same time machine the installation grooves for installing the machine difference compensation pads on the die holder.

[0009] In the above step S1, the stiffness measurement is carried out according to the method in the national standard GB / T 29546-2013 "Measurement Method for Static Load Deformation of Closed Die Presses", and the parallelism measurement is carried out according to the measurement method of the parallelism between the lower plane of the slide block and the workbench surface in the national standard GB / T 10924-2009 "Accuracy of Closed Single and Double Point Presses".

[0010] The specific steps of step S2 are as follows: S21. Input the press stiffness information: Input the results of the press stiffness measurement in S1 into the Press Generator module in AutoForm to generate a press stiffness model as the boundary condition for simulation. S22. Set the stamping parameters: Import the geometric structures of the die and the die holder into AutoForm and set the stamping working conditions. S23. Conduct simulation analysis: Conduct stamping simulation to test the closing state of the die and the die surface deformation under different heights of the machine difference compensation pads. S24. Determine the compensation height: Determine the specific heights of the machine difference compensation pads required for different presses by analyzing the simulation results.

[0011] In the above step S21, the input information includes the materials of the press slide block and the workbench, the load position, and the coordinate information of the measuring points.

[0012] In the above step S22, the stamping working conditions include the die material, the forming pressure, and the stamping speed, and the simulation conditions should be consistent with the previously formulated stamping parameters.

[0013] Compared with the prior art, in the present invention, the stiffness and parallelism data of the presses of the die manufacturer and the die user are measured through experiments. Grooves are machined on the die base to install the machine difference compensation pads, and the simulation technology is used to determine the height of the pads required for different presses. Thus, the corresponding compensation pads are used during the trial die and on the production line to eliminate the closing precision error caused by different mechanical characteristics of the presses, improve the lapping rate, effectively shorten the development cycle of stamping parts, and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic flow chart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The present invention will be further described below with reference to the drawings.

[0016] As Figure 1 shown, the machine difference compensation method for avoiding die surface repair in this embodiment includes the following steps: S1. Measure the stiffness and parallelism of the presses of the die manufacturer and the die user respectively, providing key parameter data for subsequent machine difference compensation.

[0017] S2. Combine the data obtained in step S1, conduct stamping simulation, simulate the working conditions of the die on different presses, and calculate the dimensions of the required machine difference compensation pads respectively; S3. Manufacture the machine difference compensation pads with corresponding dimensions, and at the same time machine installation grooves for installing the machine difference compensation pads on the die base of the die.

[0018] During specific use, before step S1 starts, it is necessary to prepare necessary equipment and tools first, including: precision measuring tools, such as laser rangefinders, electronic level gauges, micrometers, etc. Computer software for stamping simulation and data processing. Machining equipment such as CNC milling machines and lathes, and machine difference compensation pad materials with high strength and wear resistance.

[0019] In step S1, the stiffness measurement is carried out according to the method in the national standard GB / T 29546-2013 "Measurement Method for Static Load Deformation of Closed-Type Presses". This national standard is the national standard in China for detecting the deformation amount of closed-type presses under static loads, and the measurement of the overall machine stiffness is one of the core contents. Specifically, the overall machine stiffness refers to the ratio of the average relative deformation amount between the worktable surface and the slider bottom surface to the nominal force under the action of a static uniform load on the press. Its calculation formula is: . Where CA is the overall machine stiffness, with the unit of kilonewtons per millimeter (kN / mm); P is the nominal force of the press, with the unit of kilonewtons (kN); Δ60 is the average value of the readings of four indicating gauges when the load is increased from 40% of the nominal force to 100% of the nominal force, with the unit of millimeters (mm).

[0020] The parallelism measurement is carried out according to the measurement method of the parallelism between the lower plane of the slide block and the workbench surface in the national standard GB / T 10924-2009 "Accuracy of Closed Single and Double Point Presses". This national standard is formulated in China for the accuracy requirements and inspection methods of closed single and double point presses. It is applicable to closed mechanical presses for general purposes, including crank presses and eccentric presses. It includes the measurement method of the parallelism between the lower plane of the slide block and the workbench surface, that is, a straightedge with an indicator is placed around the lower table, the measuring head of the indicator is pressed against the lower plane of the slide block, the stroke of the slide block is changed, and the indicator is moved and measured at the same time. Observe the reading difference of the indicator at both endpoints to calculate the parallelism.

[0021] At present, versions above AutoForm R11 have supported stamping simulation considering the deformation of the press. The principle is that by inputting the stiffness characteristics of the press (such as the overall stiffness of the press, the stiffness of the slide block, etc.) or the measured deformation data (such as the deflection of the slide block) as the boundary conditions of the die, it can truly reflect the influence of the press deformation on the die surface and obtain the actual deformation of the die. Using the AutoForm software, the specific steps of S2 are as follows: S21, Input the stiffness information of the press: Input the results of the press stiffness measurement in S1 into the Press Generator module in AutoForm, including information such as the materials of the press slide block and the workbench, the load position, and the coordinates of the measurement points, to generate a press stiffness model as the boundary condition for the simulation.

[0022] S22, Set the stamping parameters: Import the geometric structures of the die and the die holder into AutoForm and set the stamping conditions, including die materials, forming pressure, stamping speed, etc. The simulation conditions should be consistent with the previously formulated stamping parameters.

[0023] S23, Conduct simulation analysis: Conduct stamping simulation to test the closed state of the die and the deformation of the die surface under different height difference compensation pads.

[0024] S24, Determine the compensation height: Determine the specific height of the height difference compensation pads required for different presses by analyzing the simulation results.

[0025] The specific method of step S3 is as follows: S31, First, determine the size of the height difference compensation pad according to the die size, and mark the installation groove position and size of the height difference compensation pad; then carry out actual processing on a CNC milling machine or lathe according to the design drawing to ensure that the depth, width, and position of the groove meet the installation requirements; after processing, use measuring tools to check the groove to confirm that the processing accuracy meets the design requirements and carry out necessary trimming. The groove should have precise positioning to ensure the stable assembly of the compensation pad.

[0026] S32. According to the compensation height in the simulation results, use processing equipment to manufacture machine difference compensation pads with corresponding heights to ensure the accurate dimensions of the pads. During the mold trial production process and on the whole vehicle production line, install machine difference compensation pads with corresponding heights to ensure that the pads are firmly fastened and in the correct position.

[0027] S33: After all preparations are completed, conduct a trial production. During the trial production process, make detailed records of the height of the pads and the trial production situation.

[0028] Through the method of the present invention, the mold closing precision error caused by the mechanical characteristics of different presses can be effectively eliminated, thereby effectively improving the mating rate of stamping parts. After verification by simulation and actual measurement, this method can ensure the dimensional consistency of parts on the production line, meeting high-standard quality requirements. It significantly improves the efficiency of mold debugging, reduces the required manual mating time, and reduces the quality problems of stamping parts caused by different mechanical characteristics of presses.

Claims

1. A machine difference compensation method without repairing the die surface, characterized in that: It includes the following steps: S1. Measure the stiffness and parallelism of the presses in the die manufacturing factory and the die using factory respectively; S2. Combine the data obtained in step S1, conduct stamping simulation, simulate the working conditions of the die on different presses, and calculate the dimensions of the required machine difference compensation pads respectively; S3. Manufacture the machine difference compensation pads with corresponding dimensions, and at the same time machine the installation grooves for installing the machine difference compensation pads on the die holder of the die.

2. The machine difference compensation method without repairing the die surface according to claim 1, characterized in that: In step S1, the stiffness measurement is carried out according to the method in the national standard GB / T 29546-2013 "Measurement Method for Static Load Deformation of Closed Presses", and the parallelism measurement is carried out according to the measurement method of the parallelism between the lower plane of the slider and the workbench surface in the national standard GB / T 10924-2009 "Accuracy of Closed Single and Double Point Presses".

3. The machine difference compensation method without repairing the die surface according to claim 1, characterized in that: The specific content of step S2 is as follows: S21. Input the press stiffness information: Input the results of the press stiffness measurement in S1 into the PressGenerator module in AutoForm to generate a press stiffness model as the boundary condition for the simulation; S22. Set the stamping parameters: Import the geometric structures of the die and the die holder into AutoForm and set the stamping working conditions; S23. Conduct simulation analysis: Conduct stamping simulation to test the closed state of the die and the die surface deformation under different height machine difference compensation pads; S24. Determine the compensation height: Determine the specific height of the machine difference compensation pads required for different presses by analyzing the simulation results.

4. A machine difference compensation method without repairing the die surface according to claim 3, characterized in that: In step S21, the input information includes the materials of the press slider and the workbench, the load position, and the coordinate information of the measuring points.

5. A machine difference compensation method without repairing the die surface according to claim 3, characterized in that: In step S22, the stamping working conditions include the die material, the forming pressure, and the stamping speed, and the simulation conditions should be consistent with the pre-determined stamping parameters.

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