Device for detecting end face runout of a rotating object and method therefor

Abstract

A device for detecting end face runout of a rotating object, comprising a first gauge, a second gauge, a detector and a processor. The first gauge and the second gauge are arranged on the rotating end face of a workpiece to be machined. The detector is in contact with the first gauge to obtain first detection point position information, and in contact with the second gauge to obtain second detection point position information. The processor obtains the information of the detector to determine the end face runout of the rotating object. The device and detection method of the present application can be used to calculate the runout data of the tool (or workpiece) to calculate compensation or minimize the runout by adjusting the variation to be as small as possible on the two planes.

Description

Technical Field

[0001] This invention relates to a measuring tool, and more particularly to an apparatus for machining workpieces using lasers. Background Technology

[0002] Disc-shaped and rod-shaped workpieces are common in the machinery industry. There are specific requirements regarding the runout of these workpieces during machining. Taking metal cutting tools as an example, various tools (drills, milling cutters, and reamers, etc.) are generally disc-shaped or rod-shaped workpieces of various sizes, mainly used for cutting, and undergo rotational motion during machining. These tools typically rotate at high speed, causing their cutting edges to contact, compress, cut, and remove the workpiece. When the tool's rotational accuracy is poor (e.g., radial runout and / or axial runout), it will exacerbate cutting vibration, leading to a series of cutting abnormalities such as deterioration of the machined surface roughness, shortened tool life, and significant deviations from machining specifications. Therefore, reducing the radial and / or axial runout of tools is an important technical issue in the tooling industry.

[0003] In existing technologies, to achieve good runout, the following aspects are generally considered: heat treatment (e.g., leaving a margin exceeding the deformation amount before heat treatment → deformation occurs during heat treatment → precision workpiece is obtained after finishing by removing the margin after heat treatment), installation during processing (using bar clamping devices such as tool holders with higher precision), compensation during processing (using contact probes or laser measuring devices to detect runout of the clamped bar and compensating for the coordinates in the processing code based on the detection results), temperature control during processing (using water cooling or air cooling to avoid thermal deformation caused by processing), and adjustment during use (using tool holders with higher precision or directly using tool clamping devices that can compensate for runout). In addition, the runout of the machined tool mainly relies on the rotational accuracy of the processing equipment itself.

[0004] In practice, the above technical means are generally used in combination. For example, a high-precision HSK interface is used to improve the runout during tool installation. At the same time, a dial indicator is used to measure and adjust the runout during tool installation through adjustable structures such as flange interfaces. Finally, the runout state of the tool on the spindle is detected by a probe and compensated by the machining program.

[0005] Both face runout and radial runout are used to characterize workpiece runout and can be converted into each other. However, due to the asymmetric effect between angular and distance increments, we cannot always check and measure the true runout at the cutting edge by measuring the change in radial distance between any two points on the workpiece end face and its central axis. Generally speaking, when the tool diameter is large, even if the measured radial runout t11 ​​is small, the face runout t12 may still be large (see...). Figure 1 Correspondingly, when the tool length is very long, such as... Figure 2Even if the face runout t21 is very small, the radial runout t22 may still be large. Therefore, measuring the runout of large-diameter tools using the general two-point circumferential method is not always a reliable method.

[0006] Generally, regardless of the measurement method used, measuring runout requires defining two circumferential surfaces at a certain distance on a cylindrical part, examining the change in radial distance between these two circumferential surfaces and their central axis, and calculating the total runout data for compensation calculations or minimizing runout by adjusting the change in these two planes to the smallest possible value. However, existing technologies have significant limitations when the tool shape changes. Due to the asymmetric effect between angular and distance increments, technicians cannot always check and measure the true runout of the cutting edge by examining the change in radial distance between any two circumferential surfaces on the tool and their central axis. For example, when the tool is very long axially, but the runout reference position is too far from the cutting edge, or when the tool diameter is very long, even if the change in radial distance between the circumferential surfaces and their central axis at the two reference positions is small enough, it is insufficient to guarantee the runout at the cutting edge position.

[0007] In addition, direct measurement technologies based on vision or lasers have emerged. These non-contact methods for directly measuring tool runout have become a more reliable solution. However, non-contact measurement methods also have inherent drawbacks, such as the measurement accuracy varying with the diameter of the object being measured. When the diameter exceeds 50mm, the accuracy of existing laser measurements decreases significantly. Therefore, in practical applications, both laser and vision measurements either have very small measurement ranges or require complex mechanical structures to control the positional relationship between the camera / lens and the workpiece, performing non-contact measurements in a manner similar to coordinate measuring machines. All of these limitations, along with factors such as application scenarios and cost, restrict the application of these technologies in the precision measurement of tool runout. Summary of the Invention

[0008] One object of the present invention is to provide a device for detecting runout, so as to detect and understand the runout of the end face of a rotating object, which is beneficial to the manufacturing of cutting tools.

[0009] Another objective of this invention is to provide a device for detecting runout, so as to detect and understand the runout of the end face of a rotating object, which is beneficial to the manufacture of cutting tools with a rotating end face diameter greater than 50mm.

[0010] Another object of the present invention is to provide a method for detecting runout, thereby improving the accuracy of runout measurement during the rotary machining of workpieces (and cutting tools).

[0011] Another objective of this invention is to provide a method for detecting runout, thereby improving the accuracy of runout measurement during the rotary machining of workpieces (and cutting tools) with a rotary end face diameter greater than 50 mm.

[0012] In machining, common machining tools currently include grinding wheels, cutting tools, and lasers.

[0013] In machining, the term "material" or "workpiece" typically refers to materials or semi-finished products used to manufacture parts or components; it is the object of machining during the mechanical process. That is, after machining the workpiece, a product that meets the machining or design requirements is obtained, such as hole-making tools and milling cutters. For workpieces used for tool machining, they typically include an axis, with the axial length greater than the radial length.

[0014] Precision machining refers to machining techniques that achieve extremely high levels of precision and surface quality. For example, in tool machining, dimensions, straightness, contour accuracy, surface roughness, and cutting edge radius are all achieved at a level exceeding micrometers.

[0015] Machining equipment (or machining centers) are processing devices with multiple axes of motion. These are the X, Y, and Z axes, which move along straight lines in a right-handed Cartesian coordinate system, and the A, B, and C axes, which rotate around the X, Y, and Z axes, respectively. For example, CNC machine tools typically have various control software programs that receive and issue commands in code form to automate the machining of workpieces. For instance, by forming the method for forming the drill tip of a machining tool provided in this invention into control code, it can be automatically implemented on machining equipment to obtain products that meet machining or design requirements.

[0016] To achieve more accurate runout measurement and calculation at the cutting edge position, especially for large-diameter tools, while avoiding the aforementioned problems of non-contact measurement, this invention proposes a method comprising:

[0017] A first reference plane and a second reference plane are set on the rotating end face of the workpiece to which the cutting tool is made. The first reference plane is larger than the second reference plane, so that the outer edge of the second reference plane is closer to the center of rotation than the outer edge of the first reference plane.

[0018] The position information of the first detection point is obtained on the first reference plane, and the position information of the second detection point is set on the second reference plane. When viewed from the orthographic projection of the rotating end face, the line connecting the first detection point and the second detection point passes through the rotation center of the end face, thus forming a set of detection marks.

[0019] At least two sets of detection marks must be obtained during the end face rotation;

[0020] If the positional information of the two sets of detection markers deviates in the direction of rotation, it is considered that a jump has occurred;

[0021] The magnitude of the deviation indicates a positive correlation between the degree of fluctuation and the occurrence of the fluctuation.

[0022] For minute fluctuations, multiple sets of detection markers are required. When only two sets of detection markers are used, their position information should be obtained before and after the end face rotates 180°.

[0023] The distance between the radially arranged, rotating end faces is used as the spacing distance, which is at least 30% of the shortest distance from the outer edge of the first reference plane to the cutting edge.

[0024] In the method of this invention, the first reference plane is an annular surface. The width of the annular surface is 1 mm or more. A gap is arranged between the first reference plane and the second reference plane.

[0025] In the method of this invention, the second reference plane is an annular surface. The width of the annular surface is 1 mm or more.

[0026] In the method of this invention, the second reference plane is an annular surface. The inner diameter used is 5 mm or more.

[0027] The apparatus of the present invention includes:

[0028] The first measuring tool is placed on the rotating end face of the workpiece that has been made into a cutting tool;

[0029] The second measuring tool is placed on the rotating end face of the workpiece that has been made into a cutting tool;

[0030] The detector obtains the position information of a first detection point by contacting a first measuring instrument, and obtains the position information of a second detection point by contacting a second measuring instrument; and

[0031] The processor acquires information from the detector and determines the end face runout of the rotating object.

[0032] A gap is set between the first and second measuring tools, and the distance between the gaps is the radial distance of the rotating end faces.

[0033] The processor will observe from the orthographic projection of the rotating end face. The line connecting the first detection point and the second detection point passes through the rotation center of the end face as a set of detection marks. Based on at least two sets of detection marks, the processor will calculate the position information in the direction of rotation. If the deviation occurs, it will determine that a jump has occurred.

[0034] The first measuring instrument includes a toroidal surface, which serves as a first reference plane and contacts the detector, enabling the detector to obtain the position information of the first detection point.

[0035] The second measuring tool includes a toroidal surface, which serves as a second reference plane and contacts the detector, enabling the detector to obtain the position information of the second detection point.

[0036] The distance between the first reference plane and the second reference plane is at least 30% of the shortest distance from the outer edge of the first reference plane to the cutting edge.

[0037] The first and second measuring tools may be individually or jointly made of a toroidal surface with a width of 1 mm or more. The two arcs that define the toroidal surface are either continuous arcs or segmented lines with intervals between them, but the overall arrangement of the segments still presents an arc.

[0038] By acquiring information about the different positions of the rotating end face of the tool (or workpiece) under different states, and the change in axial distance between it and the plane of its rotating shaft end, runout data is obtained for calculation compensation or runout is minimized by adjusting the change in these two planes to be as small as possible. Attached Figure Description

[0039] Figure 1 A schematic diagram of tool runout with a large diameter end face;

[0040] Figure 2 A schematic diagram of the runout of a tool face with a long axis system;

[0041] Figure 3 This is a schematic diagram of an embodiment of the device of the present invention applied to a large-diameter end face;

[0042] Figure 4 This is a schematic diagram of an embodiment of the method for determining jump in the present invention;

[0043] Figure 5 This is a schematic diagram of another embodiment of the method of the present invention for detecting tool end face runout. Detailed Implementation

[0044] 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.

[0045] Large-diameter end faces are typically 50 mm or more for cutting tools or workpieces intended to be made into cutting tools. Figure 3 This is a schematic diagram of an embodiment of the device of the present invention applied to a large-diameter end face. For example... Figure 3As shown, the first measuring tool 100 and the second measuring tool 200 are annular, with a width of 1 mm or more and a surface roughness of less than Ra1 μm. Both are mounted on the rotating end face 10 of the workpiece used to manufacture the cutting tool. A gap is provided between the first and second measuring tools, the gap being a radial distance of the rotating end face. The first measuring tool 100 includes an annular surface 110, which serves as a first reference plane and contacts a detector (not shown), enabling the detector to obtain first detection point position information. The second measuring tool 200 includes an annular surface 210, which serves as a second reference plane and contacts the detector, enabling the detector to obtain second detection point position information. The gap distance L2 between the first reference plane 110 and the second reference plane 210 is at least 30% of the shortest distance L1 from the outer edge of the first reference plane to the cutting edge 20.

[0046] Figure 4 This is a schematic diagram illustrating an embodiment of the method for determining jitter according to the present invention. (In conjunction with...) Figure 3 ,like Figure 4 As shown, end face 10 is the end face reference plane, but in practice, it is difficult to measure and know. End faces 11 and 12 represent the actual states of the end faces during rotation. When the end face is in the state of end face 11, the position information A of the first detection point is obtained on the first reference plane, and the position information B of the second detection point is set on the second reference plane. Observed from the orthographic projection of the rotating end face, the line connecting the first and second detection points passes through the rotation center of the end face, thus forming the first set of detection marks. When the end face rotates to the state of end face 12, the position information A' of the first detection point is obtained on the first reference plane, and the position information B' of the second detection point is set on the second reference plane. Observed from the orthographic projection of the rotating end face, the line connecting the first and second detection points passes through the rotation center of the end face, thus forming the second set of detection marks.

[0047] The two sets of detection information obtained above are processed by the processor. When the position information in the rotation axis direction deviates, it is considered that runout has occurred. The magnitude of the deviation is positively correlated with the degree of runout. Thus, after adjustment, when the deviation value continuously decreases, it indicates that the rotating end face of the tool (or workpiece) is closer to the reference end face 10, resulting in higher rotational accuracy and higher surface quality in actual application machining.

[0048] Preferably, the inner diameter of the annular second measuring tool 200 in this embodiment is typically 5 mm or more, so that the detection point is at least 5 mm away from the rotation center. When the second measuring tool 200 is a continuous plane (e.g., a circular surface with a diameter of less than 6 mm), or when an annular second measuring tool 200 with a smaller inner diameter (e.g., 4 mm or less) is placed on the rotation end face, so that the detection point is close to or on the rotation center, the detection point position information and deviation value will be regarded as 0. Then, the degree of rotation end face runout can also be obtained by measuring the position information of the detection point on the first reference plane, but the information obtained still deviates from the actual situation.

[0049] Taking a general-purpose face milling cutter with a shank diameter of 32mm, a shank length of 45mm, and a cutting edge diameter of 180mm as an example, such as Figure 5 As shown, due to the relatively short shank, the existing runout detection method can measure the tool installation runout as 5μm in the circumferential direction, which theoretically meets the tool runout requirements. However, if the solution in this embodiment is used for measurement, with the first and second gauges set near the cutting edge and near the center respectively, and measurements taken accordingly, the actual circumferential and end face runouts of the tool can be measured as 5μm and 12μm, respectively. These do not meet the tool runout machining requirements, and the installation position needs to be adjusted or compensation needs to be performed to obtain a product with the correct accuracy requirements.

Claims

1. A device for detecting the end face jump of a rotating object, characterized in that... include: The first measuring tool is placed on the rotating end face of the workpiece to which the cutting tool is made. The second measuring tool is placed on the rotating end face of the workpiece on which the cutting tool is made. The detector contacts the first measuring instrument to obtain the position information of the first detection point, and contacts the second measuring instrument to obtain the position information of the second detection point. and The processor acquires information from the detector and determines the end face runout of the rotating object. An interval is set between the first and second measuring tools.

2. The apparatus according to claim 1, characterized in that... The processor will observe from the orthographic projection of the rotating end face. The line connecting the first detection point and the second detection point passes through the rotation center of the end face as a set of detection marks. Based on at least two sets of detection marks, it will calculate the position information in the direction of rotation. If the position deviates, it will determine that a jump has occurred.

3. The apparatus according to claim 1, characterized in that... The first measuring tool includes a toroidal surface, which serves as a first reference plane and contacts the detector, enabling the detector to obtain the position information of the first detection point.

4. The apparatus according to claim 1, characterized in that... The first measuring tool includes a toroidal surface, which serves as a first reference plane and contacts the detector, enabling the detector to obtain the position information of the first detection point.

5. The apparatus according to claim 1, characterized in that... The first measuring tool includes an annular surface, which serves as a first reference plane and contacts the detector, thereby enabling the detector to obtain the position information of the first detection point. The distance between the first reference plane and the second reference plane is at least 30% of the shortest distance from the outer edge of the first reference plane to the cutting edge.

6. The apparatus according to claim 1, characterized in that... The first measuring tool is ring-shaped and has a width of 1 mm or more.

7. The apparatus according to claim 1, characterized in that... The second measuring tool is annular and has a width of 1 mm or more.

8. A method for detecting end-face runout of a rotating object, characterized in that... include: A first reference plane and a second reference plane are set on the rotating end face of the workpiece to which the cutting tool is made, such that the outer edge of the second reference plane is closer to the center of rotation than the outer edge of the first reference plane. The position information of the first detection point is obtained on the first reference plane, and the position information of the second detection point is set on the second reference plane. When viewed from the orthographic projection of the rotating end face, the line connecting the first detection point and the second detection point passes through the rotation center of the end face, thus forming a set of detection marks. At least two sets of detection marks must be obtained during the end face rotation; If the positional information of the two sets of detection markers deviates in the direction of rotation, it is considered that a jump has occurred; The magnitude of the deviation indicates a positive correlation between the degree of fluctuation and the occurrence of the fluctuation.

9. The method according to claim 8, characterized in that... The spacing distance is at least 30% of the shortest distance from the outer edge of the first reference plane to the cutting edge.

10. The method according to claim 8, characterized in that... The first reference plane is a toroidal surface with a width of more than 1 mm.

11. The method according to claim 8, characterized in that... The second reference plane is a toroidal surface with a width of more than 1 mm.

12. The method according to claim 11, characterized in that... The inner diameter of the second reference plane is 5mm or more.

13. The method according to claim 8, characterized in that... The first reference plane is a toroidal surface, and an interval is arranged between the first reference plane and the second reference plane.

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