Discharging and grinding combined machining and manufacturing equipment and method for milling cutter

Abstract

The invention discloses discharging and grinding combined machining and manufacturing equipment and method for a milling cutter. The discharging and grinding combined machining and manufacturing equipment comprises a high-precision numerical control machine tool, an electric spark pulse power module and a mechanical grinding driving module. The high-precision numerical control machine tool comprises a machine tool body, a workbench and a machine tool spindle, a milling cutter blank is clamped and fixed through the workbench, the lower end of the machine tool spindle is provided with bidirectional grinding heads, and the grinding heads on the two sides are provided with a red copper grinding wheel and a diamond grinding wheel respectively. The electric spark pulse power supply module is electrically connected with a red copper grinding wheel on the bidirectional grinding head; the mechanical grinding driving module is connected with a grinding wheel on the bidirectional grinding head; the machining and manufacturing method comprises the steps of workpiece clamping and positioning, discharge grinding rough machining, grinding wheel switching and finish machining positioning and mechanical finish machining. By effectively combining the advantages of electric discharge machining and grinding machining, the machining precision and production efficiency of the milling cutter are improved, and the requirements of the modern manufacturing industry for high quality and high precision of the milling cutter are met.

Description

Technical Field

[0001] The present invention relates to the technical field of tool manufacturing, and particularly to an electric discharge grinding combined processing and manufacturing equipment and method for a milling cutter. Background Art

[0002] At present, with the booming development of modern manufacturing industry, the milling cutter, as a crucial cutting tool in machining, its manufacturing quality and production efficiency directly affect the development level of the entire machining industry. As the manufacturing industry continues to move towards high-end and precision directions, higher requirements are put forward for aspects such as the precision, wear resistance, and cutting performance of the milling cutter.

[0003] Currently, there are many manufacturing methods for milling cutters. Among them, electric discharge machining and grinding are relatively common processes. Electric discharge machining can process complex shapes and high-hardness materials, and can be used for preliminary forming and rough machining in milling cutter manufacturing. Grinding can obtain high dimensional accuracy and good surface quality, and is commonly used for the finish machining of milling cutters. However, the existing milling cutter manufacturing technologies have obvious deficiencies.

[0004] On the one hand, when using electric discharge machining alone, although a large amount of material can be quickly removed, the machining accuracy is difficult to guarantee, and the surface quality of the milling cutter will also be affected, which affects the cutting performance and service life of the milling cutter. For example, when machining high-precision mold milling cutters, the surface roughness and dimensional accuracy of the milling cutter after electric discharge machining cannot meet the requirements of subsequent mold manufacturing, and a large amount of subsequent processing is required, increasing the production cost and processing cycle.

[0005] On the other hand, if only grinding is used, the processing efficiency for high-hardness material milling cutters is extremely low, and the grinding wheel wears severely. For example, when manufacturing special milling cutters used in the aerospace field, traditional grinding is difficult to meet the dual requirements of production efficiency and machining accuracy.

[0006] Therefore, researching and developing an electric discharge grinding combined processing and manufacturing equipment and method for a milling cutter is of great significance for promoting the development of the machining industry. Summary of the Invention

[0007] To solve the deficiencies in the background art, the purpose of the present invention is to provide an electric discharge grinding combined processing and manufacturing equipment and method for a milling cutter, which combines the advantages of electric discharge and grinding to improve the machining accuracy and efficiency of the milling cutter.

[0008] To achieve the above purpose, the present invention provides the following technical solution: An electric discharge grinding combined processing and manufacturing equipment for a milling cutter, comprising a high-precision numerical control machine tool, an electric spark pulse power supply module, and a mechanical grinding drive module;

[0009] The high-precision numerical control machine tool includes a machine tool body, a workbench, and a machine tool spindle. The workbench is located at the upper end of one side of the machine tool body, and the milling cutter blank is clamped and fixed by the workbench. The workbench has the function of three-axis linkage of X, Y, and Z. The machine tool spindle is located at the upper end of the other side of the machine tool body. A two-way grinding head is equipped at the lower end of the machine tool spindle. A copper wheel and a diamond wheel are respectively installed on both sides of the grinding head, and the two wheels are installed on the same spindle. The wheel switching is realized by the rotation of the grinding head, that is, the rotation of the C axis, and the repeat positioning accuracy is less than 0.005 mm.

[0010] The electric spark pulse power supply module is electrically connected to the copper wheel on the two-way grinding head, and then outputs high-energy pulses required for rough machining. The voltage and pulse width parameters are flexibly adjusted and set according to the processing requirements to meet the requirements of discharge grinding rough machining of milling cutter blanks of different materials.

[0011] The mechanical grinding drive module is connected to the grinding wheel on the two-way grinding head, providing constant speed control and micro-feed functions. The speed control accuracy is within ±1 r / min, and the feed accuracy reaches ±0.01 mm, ensuring the accuracy and stability of mechanical grinding finish machining.

[0012] Preferably, the high-precision numerical control machine tool is provided with an absolute grating ruler and a high-precision servo control system. The real-time position information of each axis of the machine tool is accurately recorded by the absolute grating ruler, and the resolution reaches 0.001 mm, ensuring the accuracy and uniqueness of position feedback. According to the data fed back by the grating ruler, the high-precision servo control system performs real-time and accurate control on the motion trajectories and positions of each axis of the machine tool and the grinding head, ensuring the machining accuracy.

[0013] Preferably, the two-way grinding head of the high-precision numerical control machine tool adopts high-precision bearings and transmission mechanisms to ensure the smoothness and positioning accuracy of the grinding head rotation; the rotation angle accuracy of the grinding head is controlled within ±0.01°, ensuring that the grinding wheel accurately reaches the machining position after switching.

[0014] The present invention also provides a processing and manufacturing method for a discharge grinding combined processing and manufacturing equipment of a milling cutter, including the following steps:

[0015] Step S1: Workpiece clamping and positioning: The milling cutter blank is firmly fixed on the workbench of the processing machine tool to ensure that the positioning accuracy meets the processing requirements; a copper wheel and a diamond wheel are respectively installed on the two-way grinding head on the machine tool spindle, and the position of the two-way grinding head is adjusted so that the copper wheel and the milling cutter blank are in the initial machining position.

[0016] Step S2: Discharge grinding rough machining: Start the electric spark pulse power supply, and use the copper wheel to perform discharge grinding rough machining on the milling cutter blank.

[0017] Step S3: Grinding wheel switching and finish machining positioning: After the rough machining of electrical discharge grinding is completed, rotate the two-way grinding head to switch the diamond grinding wheel to the working position, and adjust the position of the grinding head so that the diamond grinding wheel and the milling cutter blank reach the starting point of finish machining;

[0018] Step S4: Mechanical finish machining: Use the diamond grinding wheel to perform mechanical grinding finish machining on the milling cutter blank to form it in one step.

[0019] Preferably, when performing the clamping and positioning in step S1, use a high-precision clamping tooling to ensure accurate and stable positioning of the milling cutter blank, and control the positioning accuracy within the range of ±0.01 mm.

[0020] Preferably, in step S2, dynamically adjust the parameters of the rough machining of electrical discharge grinding according to the material and hardness of the milling cutter blank; set the rough machining parameters to improve the machining efficiency, including a higher machining voltage, a larger current, a longer pulse width, and a larger feed depth. For blanks with higher hardness, appropriately increase the machining voltage and current and extend the pulse width; for blanks with lower hardness, reduce these parameters accordingly to optimize the machining efficiency and quality.

[0021] Preferably, in step S4, according to the design requirements of the milling cutter and the surface condition after rough machining; set the finish machining parameters to ensure dimensional accuracy and surface quality. The finish machining parameters mainly include controlling the linear speed, feed speed, and grinding depth of the diamond grinding wheel. For parts with high precision requirements, reduce the feed speed and grinding depth and increase the linear speed; for parts with general precision requirements, adjust the parameters to improve the machining efficiency.

[0022] Compared with the prior art, the beneficial effects of the present invention: The present invention can effectively combine the advantages of electrical discharge machining and grinding through the combined machining manufacturing method and equipment of electrical discharge grinding of milling cutters, improve the machining accuracy and production efficiency of milling cutters, and meet the requirements of modern manufacturing industry for high-quality and high-precision milling cutters. Description of the Drawings

[0023] The drawings are used to provide further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention.

[0024] In the drawings:

[0025] Figure 1 is a schematic diagram of the combined machining manufacturing equipment for electrical discharge grinding of the milling cutter of the present invention;

[0026] Figure 2 is a flow chart of the combined machining manufacturing method for electrical discharge grinding of the milling cutter of the present invention;

[0027] Figure 3It is a schematic diagram of the initial machining of the straight groove of the milling cutter blank with a copper wheel and a diamond wheel provided by the present invention. Among them, a is a schematic diagram of the initial tool alignment of the copper wheel and the diamond wheel, b is a schematic diagram of rough machining by electric discharge of the copper wheel, c is a schematic diagram of converting the wheel, and d is a schematic diagram after finishing machining with the diamond wheel;

[0028] Reference numerals in the figure: 1, workbench; 2, milling cutter blank; 3, copper wheel; 4, machine tool spindle; 5, diamond wheel; 6, electric spark pulse power supply; 7, machine tool body. Specific embodiments

[0029] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0030] As Figure 1 shown, a combined electric discharge grinding manufacturing equipment for a milling cutter includes a high-precision numerical control machine tool, an electric spark pulse power supply 6 module, and a mechanical grinding drive module.

[0031] The high-precision numerical control machine tool includes a machine tool body 7, a workbench 1, and a machine tool spindle 4. The workbench 1 is located at the upper end of one side of the machine tool body 7, and the milling cutter blank 2 is clamped and fixed through the workbench 1. The workbench 1 has the function of X, Y, and Z axis linkage. The machine tool spindle 4 is located at the upper end of the other side of the machine tool body 7. A two-way grinding head is equipped at the lower end of the machine tool spindle 4. A copper wheel 3 and a diamond wheel 5 are respectively installed on both sides of the grinding head, and the two wheels are installed on the same spindle. The wheel is switched by rotating the grinding head, that is, rotating the C axis, and the repeat positioning accuracy is less than 0.005 mm; the machine tool control system accurately controls the movement trajectory and position of the grinding head to ensure the machining accuracy; among them, the high-precision numerical control machine tool is provided with an absolute grating scale and a high-precision servo control system. The real-time position information of each axis of the machine tool is accurately recorded through the absolute grating scale, and the resolution reaches 0.001 mm to ensure the accuracy and uniqueness of position feedback; according to the data fed back by the grating scale through the high-precision servo control system, the movement of each axis of the machine tool is accurately controlled in real time. Among them, the two-way grinding head of the high-precision numerical control machine tool adopts high-precision bearings and transmission mechanisms to ensure the smoothness and positioning accuracy of the grinding head rotation; the rotation angle accuracy of the grinding head is controlled within ±0.01° to ensure that the grinding wheel reaches the machining position accurately after switching.

[0032] Among them, the electric spark pulse power supply 6 module is electrically connected to the copper wheel 3 on the two-way grinding head, and then outputs high-energy pulses required for rough machining. The voltage and pulse width parameters are flexibly adjusted according to the machining requirements to meet the requirements of electric discharge grinding rough machining of milling cutter blanks 2 made of different materials.

[0033] Among them, the mechanical grinding drive module is connected to the grinding wheel on the two-way grinding head, providing constant rotational speed control and micro-feed functions. The rotational speed control accuracy is within ±1 r / min, and the feed accuracy reaches ±0.01 mm, ensuring the accuracy and stability of mechanical grinding finish machining.

[0034] As Figure 2 shown, the present invention also provides a manufacturing method for a combined electrical discharge grinding and machining equipment for milling cutters, including the following steps:

[0035] Step S1: Workpiece clamping and positioning: Firmly fix the milling cutter blank 2 on the workbench 1 of the processing machine tool to ensure that the positioning accuracy meets the processing requirements; install a copper grinding wheel 3 and a diamond grinding wheel 5 on the two-way grinding head on the machine tool spindle 4 respectively, and adjust the position of the two-way grinding head so that the copper grinding wheel 3 and the milling cutter blank 2 are in the initial processing position; when clamping and positioning, use a high-precision clamping tooling to ensure that the milling cutter blank 2 is accurately and firmly positioned, and the positioning accuracy range is controlled within ±0.01 mm.

[0036] Step S2: Rough electrical discharge grinding: Start the electric discharge pulse power supply 6, and perform rough electrical discharge grinding on the milling cutter blank 2 using the copper grinding wheel 3; among them, dynamically adjust the parameters of the rough electrical discharge grinding according to the material and hardness of the milling cutter blank 2; set the rough machining parameters to improve the processing efficiency, including a higher machining voltage, a larger current, a longer pulse width, and a larger feed depth. For blanks with higher hardness, appropriately increase the machining voltage and current, and extend the pulse width; for blanks with lower hardness, reduce these parameters accordingly to optimize the processing efficiency and processing quality; establish a hierarchical machining parameter matching strategy, including:

[0037] When the hardness of the blank is higher than the first hardness threshold, adopt the first preset voltage range and the first preset current value, and match the first-level pulse width and the first feed depth parameters;

[0038] When the hardness of the blank is lower than the second hardness threshold, correspondingly adopt the second preset voltage range and the second preset current value, and configure the second-level pulse width and the second feed depth parameters.

[0039] Through the stepped parameter matching mechanism, on the premise of ensuring the processing stability, achieve the balanced optimization of the material removal rate and the processing surface quality.

[0040] Step S3: Grinding wheel switching and finish machining positioning: After the rough electrical discharge grinding is completed, rotate the two-way grinding head to switch the diamond grinding wheel 5 to the working position, and adjust the position of the grinding head so that the diamond grinding wheel 5 and the milling cutter blank 2 reach the starting point of finish machining.

[0041] Step S4: Mechanical finishing: Use a diamond grinding wheel 5 to perform mechanical grinding and finishing on the milling cutter blank 2 to form it in one step. Among them, according to the design requirements of the milling cutter and the surface condition after rough machining, set the finishing parameters to ensure dimensional accuracy and surface quality. The finishing parameters mainly include controlling the linear speed, feed speed, and grinding depth of the diamond grinding wheel 5. For parts with high precision requirements, reduce the feed speed and grinding depth and increase the linear speed. For parts with general precision requirements, increase the parameters to improve processing efficiency.

[0042] This embodiment takes the preliminary machining of a straight groove of a milling cutter blank as an example, and the specific machining process is as follows:

[0043] First is workpiece clamping and positioning (corresponding to step S1). As Figure 3 (a) shows, firmly fix the milling cutter blank 2 on the workbench 1 of a high-precision CNC machine tool to ensure accurate and stable positioning of the milling cutter blank 2, and control the positioning accuracy within ±0.01 mm. Install a copper grinding wheel 3 and a diamond grinding wheel 5 on the two-way grinding heads of the machine tool respectively. Adjust the positions of the two-way grinding heads through the machine tool control system so that both the copper grinding wheel 3 and the diamond grinding wheel 5 perform tool setting operations on the milling cutter blank 2, and confirm their respective initial positions to prepare for subsequent processing.

[0044] Then is electrical discharge grinding rough machining (corresponding to step S2). As Figure 3 (b) shows, start the electrical discharge pulse power supply module 6 and connect it to the copper grinding wheel 3 on the two-way grinding head. Use the copper grinding wheel 3 to perform electrical discharge grinding rough machining on the milling cutter blank 2. Dynamically set the rough machining parameters according to the material and hardness of the milling cutter blank 2 to improve processing efficiency. The parameters specifically include: the set value of the machining voltage that increases correspondingly with the increase of material hardness, the peak current density parameter that is positively correlated with material hardness, the pulse duration parameter extended based on hardness characteristics, and the progressive layer-by-layer feed depth strategy adapted to hardness changes. When using high-hardness materials: increase the voltage set value, increase the current magnitude, extend the duration of each discharge, and increase the depth of each tool plunge. When using low-hardness materials: appropriately reduce the above parameter values, which can not only improve processing efficiency but also ensure stable processing quality.

[0045] During the electrical discharge grinding rough machining process, the discharge state is monitored in real time through voltage and current sensors and data is collected. Once abnormal discharge or short circuit is detected, the machining is paused, and the grinding wheel position is adjusted by the machine tool control system and then the machining continues.

[0046] After that is grinding wheel switching and finishing positioning (corresponding to step S3). As Figure 3As shown in (c), after the rough machining of discharge grinding is completed, the two-way grinding head of the machine tool rotates through the C-axis to switch the diamond grinding wheel 5 to the working position. Subsequently, the machine tool control system adjusts the position of the grinding head again to make the diamond grinding wheel 5 and the milling cutter blank 2 reach the starting point of finish machining, ensuring the accurate position of finish machining.

[0047] Finally, it is mechanical finish machining (corresponding to step S4). As Figure 3 shown in (d), the mechanical grinding finish machining of the milling cutter blank 2 is carried out using the diamond grinding wheel 5 to form it in one step. According to the design requirements of the milling cutter and the surface condition after rough machining, the linear speed, feed speed and grinding depth of the diamond grinding wheel 5 are accurately set. For the parts with high precision requirements, the feed speed and grinding depth are reduced and the linear speed is increased; for the parts with general precision requirements, the parameters are appropriately adjusted to improve the machining efficiency.

[0048] During the mechanical finish machining process, the grinding state of the diamond grinding wheel 5 is monitored in real time to ensure the stability of machining. When all the machining processes of the milling cutter blank 2 are completed, the machining ends.

[0049] Through the above specific implementation manners, the method and equipment for combined machining and manufacturing of milling cutters by electrical discharge grinding of the present invention can effectively combine the advantages of electrical discharge machining and grinding machining, improve the machining precision and production efficiency of milling cutters, and meet the requirements of modern manufacturing industry for high-quality and high-precision milling cutters.

[0050] Finally, it should be noted that the above are only preferred examples of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A combined electrical discharge grinding manufacturing equipment for a milling cutter, characterized in that: It includes a high-precision numerical control machine tool, an electric discharge pulse power supply module, and a mechanical grinding drive module; The high-precision numerical control machine tool includes a machine tool body, a workbench, and a machine tool spindle. The workbench is located at the upper end of one side of the machine tool body. The milling cutter blank is clamped and fixed through the workbench. The workbench has the function of X, Y, and Z axis linkage. The machine tool spindle is located at the upper end of the other side of the machine tool body. A two-way grinding head is equipped at the lower end of the machine tool spindle. Copper wheels and diamond wheels are respectively installed on both sides of the grinding head, and the two wheels are installed on the same spindle. The wheel switching is realized by the rotation of the grinding head, that is, the rotation of the C axis; The electric discharge pulse power supply module is electrically connected to the copper wheel on the two-way grinding head, and then outputs high-energy pulses required for rough machining. The voltage and pulse width parameters are set according to the processing requirements to meet the requirements of the discharge grinding rough machining of milling cutter blanks made of different materials; The mechanical grinding drive module is connected to the grinding wheel on the two-way grinding head and is used to provide constant speed control and micro-feed functions.

2. The combined electrical discharge grinding manufacturing equipment for a milling cutter according to claim 1, characterized in that: The high-precision numerical control machine tool is equipped with an absolute grating scale and a servo control system. The real-time position information of each axis of the machine tool is accurately recorded through the absolute grating scale; according to the data fed back by the grating scale through the servo control system, the motion trajectories and positions of each axis of the machine tool and the grinding head are accurately controlled in real time.

3. The combined electrical discharge grinding manufacturing equipment for a milling cutter according to claim 1, characterized in that: The two-way grinding head of the high-precision numerical control machine tool adopts high-precision bearings and transmission mechanisms, and the rotation angle accuracy of the grinding head is controlled within ±0.01° to ensure that the grinding wheel reaches the processing position after switching.

4. The manufacturing method of a combined electrical discharge grinding manufacturing equipment for a milling cutter according to any one of claims 1-3, characterized in that, It includes the following steps: Step S1: Workpiece clamping and positioning: Fix the milling cutter blank on the workbench; install a copper wheel and a diamond wheel on the two-way grinding head on the machine tool spindle respectively, and adjust the position of the two-way grinding head so that the copper wheel and the milling cutter blank are in the initial processing position; Step S2: Discharge grinding rough machining: Start the electric discharge pulse power supply, and use the copper wheel to perform discharge grinding rough machining on the milling cutter blank; Step S3: Grinding wheel switching and finish machining positioning: After the discharge grinding rough machining is completed, rotate the two-way grinding head to switch the diamond wheel to the working position, and adjust the position of the grinding head so that the diamond wheel and the milling cutter blank reach the starting point of finish machining; Step S4: Mechanical finish machining: Use the diamond wheel to perform mechanical grinding finish machining on the milling cutter blank to form it in one time.

5. The combined electrical discharge grinding manufacturing equipment for a milling cutter according to claim 4, characterized in that: When performing the clamping and positioning in Step S1, a clamping fixture is used, and the positioning accuracy range is controlled within ±0.01 mm.

6. The electrical discharge grinding combined machining and manufacturing equipment for a milling cutter according to claim 4, characterized in that: In Step S2, according to the material and hardness of the milling cutter blank, the parameters of the discharge grinding rough machining are dynamically adjusted; the rough machining parameters are set, including the machining voltage, current, pulse width, and feed depth.

7. A combined electrical discharge grinding and machining manufacturing equipment for a milling cutter according to claim 4, characterized in that: In Step S4, according to the design requirements of the milling cutter and the surface condition after rough machining; the finish machining parameters are set. The finish machining parameters mainly include controlling the linear speed, feed speed, and grinding depth of the diamond wheel.

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