Method for machining a workpiece, and grinder and use thereof

Abstract

A method for machining a workpiece includes setting at least one pair of grinding wheels on both sides of the workpiece and simultaneously performing roughing or finishing. During machining, the two grinding wheels grind the workpiece simultaneously without interference, without any order of rotation. During grinding, the grinding wheels on both radial sides of the workpiece are not at the same horizontal height, avoiding fluctuations in workpiece dimensions and accuracy caused by grinding cycle resonance. The simultaneous machining on both sides significantly improves machining efficiency, reaching more than four times that of existing cylindrical grinding machines.

Description

Technical Field

[0001] This invention relates to a method for machining workpieces, and more particularly to a method for grinding workpieces, and its application in machining the outer diameter of workpieces, and a grinding machine for machining workpieces (e.g., stepped outer diameter) using a multi-axis linkage method. Background Technology

[0002] A CNC machine tool is an automated machine tool equipped with a program control system. This control system can logically process programs with control codes or other symbolic instructions, decode them, and thus enable the machine tool to move and process parts. The operation and monitoring of the CNC machine tool are all completed in the CNC unit.

[0003] A CNC machine tool generally consists of several parts, including the main machine, CNC control unit, drive unit, auxiliary devices, and other auxiliary equipment. The main machine is the core of the CNC machine tool, including the machine bed, column, spindle, feed mechanism, and other mechanical components. It is the mechanical component used to perform various cutting operations. The CNC control unit is the core of the CNC machine tool, including hardware (printed circuit boards, CRT display, keypad, paper tape reader, etc.) and corresponding software. It is used to input digitized part programs and to perform input information storage, data transformation, interpolation calculations, and various control functions. The drive unit is the driving component of the CNC machine tool's actuators, including the spindle drive unit, feed unit, spindle motor, and feed motor. Under the control of the CNC control unit, it achieves spindle and feed drive through an electrical or electro-hydraulic servo system. When several feeds are linked, positioning, linear, planar curve, and spatial curve machining can be completed. Auxiliary devices are some necessary supporting components for the CNC machine tool, used to ensure its operation, such as cooling, chip removal, lubrication, lighting, and monitoring. Programming and other auxiliary equipment can be used to program and store parts outside the machine.

[0004] CNC machine tools can be classified into several types based on the number of control axes, such as three-axis, four-axis, and five-axis. For the manufacturing of cutting tools, the machining of certain shapes involves five-axis linkage functions, so a five-axis linkage machine tool must be used.

[0005] Grinding of cylindrical and shaft-like parts is achieved by rotating the workpiece and grinding wheel simultaneously. During machining, due to the slender nature of the workpiece, it is generally difficult to guarantee roundness, runout, coaxiality, and straightness. Therefore, traditional machining equipment typically employs a method where grinding occurs on one side while a support structure follows on the other to ensure machining quality (e.g., roundness, runout, coaxiality, and straightness). Even so, machining efficiency remains low, thus limiting production efficiency.

[0006] Therefore, some other equipment also uses a roughing grinding wheel and a finishing grinding wheel on each side of the workpiece to improve processing efficiency to some extent. However, some problems still exist. For example, because the grinding capabilities of the roughing and finishing grinding wheels are different, using such a set of grinding wheels to grind on both sides of the workpiece simultaneously will still cause the workpiece to wobble and become non-round, and will also increase the wear on the finishing grinding wheel. To solve this problem, it is necessary to set the roughing and finishing grinding wheels on both sides of the workpiece, one in front of the other, to process the workpiece simultaneously at two asymmetrical depths. Summary of the Invention

[0007] One object of the present invention is to provide a workpiece processing method to achieve high efficiency in grinding the outer diameter (e.g., the outer diameter of a stepped workpiece).

[0008] Another objective of this invention is to provide a method for machining a workpiece, achieving precision in roundness, runout, straightness, and coaxiality in grinding the outer diameter of a workpiece (e.g., a stepped outer diameter), cylindrical or shaft-type parts.

[0009] Another object of the present invention is to provide a grinding machine that achieves high efficiency in grinding the outer diameter (e.g., the outer diameter of a stepped surface) of a workpiece.

[0010] Another object of the present invention is to provide a grinding machine that achieves precision in terms of roundness, runout, straightness and coaxiality in grinding the outer diameter of workpieces (e.g., stepped outer diameter), cylindrical or shaft parts.

[0011] Another object of the present invention is to provide an application of a grinding machine in the machining of the outer diameter of a workpiece.

[0012] The workpiece referred to in this invention is a cylindrical or conical shaft, the axial length of which is more than twice the maximum axial outer diameter of the workpiece.

[0013] A method for processing a workpiece, characterized by comprising:

[0014] At least one pair of grinding wheels are installed on both sides of the workpiece to perform roughing or finishing simultaneously;

[0015] During processing, the two grinding wheels do not interfere with each other and grind the workpiece simultaneously without any order of priority;

[0016] During grinding, the grinding wheels on both sides of the workpiece are not at the same horizontal height to avoid fluctuations in workpiece size and accuracy caused by resonance during the grinding cycle.

[0017] The workpiece processing method provided by the present invention involves grinding the workpiece with a grinding wheel while the grinding wheel remains stationary and the workpiece rotates relative to the grinding wheel.

[0018] The workpiece processing method provided by the present invention has a height difference of 0.3μm to 100μm for each grinding wheel, especially 0.3μm to 50μm.

[0019] The workpiece machining method of this invention is applied to the machining of the outer diameter of a workpiece, improving the machining accuracy of the workpiece's roundness, runout, straightness, and coaxiality. To implement this machining method, this invention also provides a grinding machine, comprising:

[0020] Base

[0021] The first main shaft has a first vertical distance from the base;

[0022] The second main axis has a second vertical distance from the base;

[0023] The first vertical distance and the second vertical distance are not equal.

[0024] The grinding machine provided by the present invention has a first spindle and a second spindle arranged on both sides of the workpiece radially during the processing of the workpiece, without interfering with each other.

[0025] The grinding machine provided by the present invention further includes a first grinding wheel assembly for rough machining of the outer diameter of a workpiece; the first grinding wheel assembly includes:

[0026] The first grinding wheel is mounted on the first spindle;

[0027] The second grinding wheel is mounted on the second spindle;

[0028] The grinding machine provided by the present invention has a first grinding wheel and a second grinding wheel disposed on both sides of the workpiece radially during the processing of the workpiece, without interfering with each other.

[0029] The grinding machine provided by this invention further includes a second grinding wheel assembly for finishing the outer diameter of the workpiece; the second grinding wheel assembly includes:

[0030] The third grinding wheel is mounted on the first spindle;

[0031] The fourth grinding wheel is located on the second spindle.

[0032] In the grinding machine provided by the present invention, the third grinding wheel and the fourth grinding wheel are arranged on both sides of the workpiece radially during the processing of the workpiece, and do not interfere with each other.

[0033] This invention provides another grinding machine, including

[0034] Base

[0035] A first grinding mechanism includes a first rotary shaft and a first spindle, with a first vertical distance between the first spindle and the base;

[0036] The second grinding mechanism includes a second rotary shaft and a second spindle, with a second vertical distance between the second spindle and the base;

[0037] The first grinding wheel assembly includes a first grinding wheel and a second grinding wheel, wherein the first grinding wheel is disposed on the first spindle and the second grinding wheel is disposed on the second spindle;

[0038] The second grinding wheel set includes a third grinding wheel and a fourth grinding wheel, with the third grinding wheel mounted on the first spindle and the fourth grinding wheel mounted on the second spindle.

[0039] The grinding machine provided by the present invention has a first grinding mechanism and a second grinding mechanism disposed on both sides of the workpiece radially during the processing of the workpiece, and they do not interfere with each other.

[0040] The grinding machine provided by the present invention has a first rotary axis that rotates in the Z direction around the XYZ coordinate system, and a second rotary axis that rotates in the Z direction around the XYZ coordinate system.

[0041] The grinding machine provided by this invention has a first spindle driven by a first rotary axis, rotating in the Z-axis of the XYZ coordinate system to achieve the alternation between a first grinding wheel and a third grinding wheel. A second spindle driven by a second rotary axis rotates in the Z-axis of the XYZ coordinate system to achieve the alternation between a second grinding wheel and a fourth grinding wheel.

[0042] The grinding machine provided by the present invention has a first vertical distance and a second vertical distance with a difference of 0.3 μm to 100 μm, especially 0.3 μm to 50 μm.

[0043] This invention provides another grinding machine, comprising:

[0044] Base

[0045] The frame is mounted on the base;

[0046] The first moving mechanism is mounted on the base and moves along the X direction of the XYZ coordinate system;

[0047] The second moving mechanism is driven by the first moving mechanism to move along the X direction;

[0048] The third rotary mechanism is driven by the second moving mechanism to move along the Y direction of the XYZ coordinate system;

[0049] The first grinding mechanism is mounted on the frame and moves along the Y direction of the XYZ coordinate system;

[0050] The second grinding mechanism is mounted on the frame and moves along the Y direction of the XYZ coordinate system;

[0051] The first grinding mechanism and the second grinding mechanism are coaxial in the Y direction of the XYZ coordinate system;

[0052] The workpiece fixture moves along the X-axis and cooperates with the third rotary mechanism to clamp both ends of the workpiece.

[0053] The grinding machine of the present invention further includes a fourth rotary axis in its workpiece clamping fixture, which is used to cooperate with the rotary mechanism to perform rotary motion on the clamped workpiece.

[0054] The grinding machine of the present invention has a detector installed on the first grinding mechanism or the second grinding mechanism for detecting the workpiece.

[0055] The various grinding machine applications and outer diameter machining of workpieces provided by this invention significantly improve the roundness, runout, straightness and coaxiality of the products, thereby improving the machining accuracy of the products.

[0056] The beneficial effects of the technical solution of this invention are as follows:

[0057] The grinding machine of this invention has at least one pair of grinding wheels on both sides of the workpiece, performing roughing or finishing simultaneously. During processing, the two grinding wheels grind the workpiece simultaneously without any order (i.e., the grinding wheels remain stationary while the workpiece moves relative to them, such as rotating). During grinding, the grinding wheels on both radial sides of the workpiece are not at the same horizontal height, effectively avoiding dimensional and accuracy fluctuations caused by grinding cycle resonance. Because both sides are processed simultaneously, the processing efficiency is significantly improved, reaching more than three times that of existing conventional cylindrical grinding machines.

[0058] The grinding machine of this invention also includes at least one pair of grinding wheels for finishing the workpiece. After the roughing grinding wheels perform roughing from both radial sides of the workpiece, they support each other, preventing the workpiece from deflecting and ensuring machining accuracy. Simultaneously, the unequal height of the two spindles (avoiding resonance caused by uniform grinding) allows for rapid grinding. After roughing, the two spindles are driven by the rotary axis to rotate 180°, and then the workpiece is simultaneously ground on both sides using finishing grinding wheels to complete the product. Testing shows that the roundness of the product can reach within ±1μm, and runout, straightness, and coaxiality can also be guaranteed within ±1μm. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the structure of an embodiment of the grinding machine of the present invention;

[0060] Figure 2 for Figure 1 The diagram shows the structure of the grinding machine from another angle. Detailed Implementation

[0061] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings. The embodiments of the present invention are only used to illustrate the technical solution of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of the invention without departing from the spirit and scope of the technical solution of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

[0062] Figure 1 This is a schematic diagram of the structure of a grinding machine according to an embodiment of the present invention. Figure 2 for Figure 1 A schematic diagram of the grinding machine from another angle is shown. (See attached diagram.) Figure 1 and Figure 2 As shown, the grinding machine in this embodiment includes a base 60 and a frame 70, with the frame 70 disposed on the base 60.

[0063] The first moving mechanism 10 is mounted on the base 60 and moves along the X direction of the XYZ coordinate system. The second moving mechanism 20 is driven by the first moving mechanism 10 to move along the X direction.

[0064] The third rotary mechanism 50 is on axis A and rotates around the X direction. It is driven by the second moving mechanism 20 to move along the Y direction.

[0065] The first grinding mechanism 30 is mounted on the frame 70 and moves along the Y direction of the XYZ coordinate system. The second grinding mechanism 40 is mounted on the frame 70 and moves along the Y direction of the XYZ coordinate system.

[0066] The first grinding mechanism 30 includes a first rotary axis 31 and a first spindle 32. The first spindle 32 moves along the Z-axis of the XYZ coordinate system, and has a first vertical distance H1 between it and the base 60. The second grinding mechanism 40 includes a second rotary axis 41 and a second spindle 42. Both the first and second grinding mechanisms move on a Y-axis guide rail of an XYZ coordinate system. The second spindle 42 moves along the Z-axis of the XYZ coordinate system, and has a second vertical distance H2 between it and the base 60. The difference between the first vertical distance H1 and the second vertical distance H2 is 0.3 μm to 100 μm. In this embodiment, a pair of roughing grinding wheels are respectively disposed on the first spindle 32 and the second spindle 42, and a pair of finishing grinding wheels are respectively disposed on the first spindle 32 and the second spindle 42. A detector 92 is provided on the first grinding mechanism 30 for detecting the workpiece 80.

[0067] In this embodiment, the frame 70 adopts a gantry-type column structure, fixed on the base 60. The crossbeam on the gantry-type column uses a set of linear guide rails, and two sets of ball screws are driven by two permanent magnet synchronous direct drive motors, respectively, to realize the movement of the first spindle 32 and the second spindle 42 along the Y direction and along the Z direction on the crossbeam. Both the first spindle 32 and the second spindle 42 are double-end face spindles. When machining the workpiece, the first spindle 32 and the second spindle 42 are located on both sides of the radial direction of the workpiece 80, without interfering with each other, to perform the machining of the stepped outer circle.

[0068] The workpiece fixture 91 moves along the X-axis and cooperates with the rotary mechanism to clamp both ends of the workpiece. In this embodiment, the workpiece fixture also includes a fourth rotary axis, which cooperates with the third rotary mechanism to perform rotary motion on the clamped workpiece.

[0069] The grinding machine provided in this embodiment has at least one pair of grinding wheels on both sides of the workpiece, performing roughing or finishing simultaneously. During machining, the two grinding wheels grind the workpiece simultaneously without any order (i.e., the grinding wheels remain stationary while the workpiece moves relative to them). During grinding, the grinding wheels on both radial sides of the workpiece are not at the same horizontal height, effectively avoiding dimensional and accuracy fluctuations caused by grinding cycle resonance. After the roughing grinding wheels perform roughing from both radial sides of the workpiece, they support each other, preventing the workpiece from deflecting and ensuring machining accuracy. Simultaneously, the unequal height of the spindles on both sides (avoiding resonance caused by uniform grinding) allows for rapid grinding. After roughing, the spindles on both sides are driven by the rotary axis to rotate 180°, and then the finishing grinding wheels simultaneously grind the workpiece on both sides to obtain the finished product. Taking a cylindrical workpiece with a length of less than or equal to 300 mm and an outer diameter of less than or equal to 300 mm as an example, the processed workpiece is measured by an optical tool setter, a roundness meter, and a three-coordinate unit. The roundness of the product can be within ±1 μm, and the runout, straightness, and coaxiality can also be guaranteed to be within ±1 μm.

Claims

1. A grinding machine, used in the machining of the outer diameter of a workpiece, to improve the machining accuracy of the workpiece's roundness, runout, straightness, and coaxiality, characterized in that... include: Base A first grinding mechanism includes a first rotary shaft and a first spindle, wherein the first spindle and the base have a first vertical distance; The second grinding mechanism includes a second rotary shaft and a second spindle, wherein the second spindle and the base have a second vertical distance; The first grinding wheel set performs rough machining on the outer diameter of the workpiece, and includes a first grinding wheel and a second grinding wheel. The first grinding wheel is disposed on the first spindle, and the second grinding wheel is disposed on the second spindle. The second grinding wheel set performs finishing on the outer diameter of the workpiece, and includes a third grinding wheel and a fourth grinding wheel. The third grinding wheel is disposed on the first spindle, and the fourth grinding wheel is disposed on the second spindle. The first spindle is driven by the first rotary shaft and rotates around the Z direction of the XYZ coordinate system, causing the first grinding wheel and the third grinding wheel to alternate. The second spindle is driven by the second rotary shaft and rotates around the Z direction of the XYZ coordinate system, causing the second grinding wheel and the fourth grinding wheel to alternate. Both the first grinding mechanism and the second grinding mechanism move on the Y-guide rail of an XYZ coordinate system; The difference between the first vertical distance and the second vertical distance is 0.3 μm to 100 μm; During the processing of the workpiece, the first grinding mechanism and the second grinding mechanism are located on both sides of the workpiece in the radial direction and do not interfere with each other; It also includes a workpiece clamp that moves along the X direction and cooperates with the third rotary mechanism to clamp both ends of the workpiece, and a fourth rotary shaft that cooperates with the third rotary mechanism to rotate the clamped workpiece. The third rotary mechanism moves along the Y direction of the XYZ coordinate system. When the grinding wheel grinds the workpiece, the grinding wheel remains stationary while the workpiece rotates relative to the grinding wheel.

2. The grinding machine according to claim 1, characterized in that... The difference between the first vertical distance and the second vertical distance is 0.3 μm to 50 μm.

3. The grinding machine according to claim 1, characterized in that... A detector is installed on either the first or the second grinding mechanism to detect the workpiece.

4. The grinding machine according to any one of claims 1 to 3, characterized in that... Also includes: The frame is mounted on the base. The first moving mechanism is disposed on the base and moves along the X direction of the XYZ coordinate system; The second moving mechanism is driven by the first moving mechanism to move along the X direction; The third rotary mechanism is driven by the second moving mechanism.

5. The grinding machine according to claim 1, characterized in that, The roundness of the products processed by the grinding machine can be within ±1μm, and the runout, straightness and coaxiality can also be within ±1μm.

6. The grinding machine according to claim 1, characterized in that: At least one pair of grinding wheels are installed on both sides of the workpiece to perform roughing or finishing simultaneously; During processing, the two grinding wheels do not interfere with each other and grind the workpiece simultaneously without any order of priority; During grinding, the grinding wheels on both sides of the workpiece are not at the same horizontal height to avoid fluctuations in workpiece size and accuracy caused by resonance during the grinding cycle.

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