High-precision pin hole machining and aligning method

Abstract

The invention relates to the technical field of machining, and discloses a high-precision pin hole machining and aligning method which is characterized by comprising the following steps: step 1, roughly boring each pin hole and boring a circle; 2, a coordinate system XOY is calibrated in the flange end face of the workpiece, a calibration datum line is set along the X axis and the Y axis, pin holes penetrating through the two ends of the calibration datum line are set as datum holes, the first point where the calibration datum line intersects with the datum holes is a first datum point, and the intersection point of the calibration datum line and the outer circle of the flange is a second datum point; step 3, measuring coordinates of the first reference point and the second reference point through a machine tool, and calculating a relative displacement value between the first reference point and the second reference point which are adjacent to each other; 4, comparing the two relative displacement values of the same calibration datum line to obtain a difference value; and 5, the center position of the machine tool spindle is adjusted according to the two difference values obtained in the step 4, and then the pin holes are finely bored. The machining method is simple and easy to implement, the part machining precision is ensured, the machining efficiency is improved, and the product cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, and in particular to a high-precision pin hole processing and alignment method. Background Art

[0002] In the field of mechanical design and manufacturing, flanged output shafts are a common component widely used in various mechanical equipment. The flange end face of the output shaft is usually provided with pin holes for external connection, which play a vital role in ensuring the precise docking of various parts of the equipment. In order to meet the requirements of high-precision assembly, the position accuracy of the pin holes usually needs to meet very high standards, such as φ0.025.

[0003] However, in the actual production process, although CNC boring and milling machines have a high degree of automation and processing accuracy, it is difficult to ensure that the position accuracy of the pin holes reaches the requirement of φ0.025 when processing pin holes due to the influence of various factors, such as thermal deformation of machine tools, wear of tool, and clamping error of workpieces. Therefore, the position of the pin holes often exceeds the tolerance during the processing, resulting in the need for rework. Rework not only increases production costs and prolongs the processing cycle, but also affects the overall production efficiency. Especially in mass production, this high-frequency rework problem is particularly prominent, which seriously affects the economic benefits and market competitiveness of the enterprise. Therefore, how to improve processing efficiency and reduce costs while ensuring the accuracy of the pin hole position has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present invention aims to provide a high-precision pin hole processing and alignment method to improve the position accuracy of pin hole processing and enhance processing efficiency.

[0005] To achieve the above object, the present invention adopts the following technical solution: a high-precision pin hole processing and alignment method, comprising the following steps:

[0006] Step 1: Fix the workpiece on the machine tool, and rough bore each pin hole on the flange end face of the workpiece until it is round;

[0007] Step 2. Select any two mutually perpendicular diameters in the flange end face of the workpiece to establish a calibration coordinate system XOY. The point of the calibration coordinate system coincides with the center of the flange end face. Set a calibration reference line along the X-axis and the Y-axis. Both ends of the calibration reference line pass through the pin hole and the center of the pin hole. The pin hole passed by the calibration reference line is set as the reference hole. The first point where the calibration reference line intersects with the reference hole is the first reference point, and the intersection with the outer circle of the flange is the second reference point.

[0008] Step 3, measuring the coordinates of the first reference point and the second reference point by a machine tool, and calculating the relative displacement value between two adjacent first reference points and the second reference point;

[0009] Step 4: compare the two relative displacement values ​​at both ends of the same calibration reference line, and obtain the difference between the two relative displacement values;

[0010] Step 5: According to the two differences obtained in step 4, adjust the center position of the machine tool spindle along the X-axis and Y-axis of the calibration coordinate system, and then fine bore each pin hole.

[0011] The principles and advantages of this solution are:

[0012] In practical application, this solution establishes a calibration coordinate system on the flange end face that has completed rough boring, and selects the pin hole through which the calibration reference hole passes as the reference hole through the X-axis and Y-axis of the coordinate system, and further obtains the first reference point and the second reference point, and then obtains the coordinates of each reference point through the machine tool, and calculates the relative displacement value between the two adjacent first reference points and the second reference point; then the difference is obtained based on the two relative displacement values ​​at both ends of the same calibration reference line, and the adjustment direction of the machine tool spindle along the X-axis or Y-axis is determined based on the positive or negative difference, and half of the absolute value of the difference is the adjustment distance, and after adjustment, the machine tool spindle is aligned with the center of the circle of the flange end face. Finally, each pin hole is finely bored to ensure the position accuracy of the pin hole.

[0013] 1. This solution can effectively eliminate the influence of factors such as thermal deformation of machine tools, tool wear, and workpiece clamping errors by introducing a calibration coordinate system and accurately measuring the coordinates of each reference point, ensuring the alignment accuracy between the machine tool spindle and the center of the flange end face. This high-precision alignment method provides a solid foundation for subsequent fine boring processing, making the position accuracy of the pin hole meet the processing accuracy standards and significantly improving product quality.

[0014] 2. This solution combines rough boring processing with calibration operations. By establishing a calibration coordinate system on the flange end face and using the reference point in the coordinate system for position adjustment, the machine tool spindle is aligned with the center of the flange end face of the workpiece. The whole process is simple and efficient. No complex equipment or tools are required, only a conventional CNC boring and milling machine is required. This method is easy to implement online on the production line, and operators can master it after simple training, which greatly reduces the technical threshold and improves operability.

[0015] 3. Applying this solution to pin hole processing can reliably guarantee the processing accuracy and reduce the rework caused by position deviation. In the past, frequent rework not only increased production costs and prolonged the processing cycle, but also affected the overall production efficiency. Through precise alignment and fine boring processing, high-quality pin hole processing can be achieved, which greatly shortens the construction cycle and improves production efficiency. Especially in mass production, the advantages of this method are particularly obvious, which helps enterprises reduce costs, improve economic benefits and market competitiveness.

[0016] 4. This processing method is not only suitable for the processing of output shaft pin holes with flanges, but also for other parts with similar structures, such as the boring and milling of planetary holes of planetary carriers. By establishing corresponding calibration coordinate systems for the flange end faces of different parts and performing alignment and fine boring processing according to the same method, it can be widely used in various mechanical manufacturing fields to solve similar problems. The versatility and flexibility of this method make it an efficient solution that meets the needs of various application scenarios.

[0017] Furthermore, in step 1, the second point where the calibration reference line intersects the reference hole is the first reference point. This arrangement facilitates the selection of the first reference point position according to the operating environment or operation convenience during actual processing, making the processing method flexible.

[0018] Furthermore, in step 3, the coordinates of the first reference hole and the second reference hole are measured by the cooperation of the machine tool and the measuring indicator.

[0019] Furthermore, the measuring indicator is a dial indicator or a micrometer, and the measuring indicator is adsorbed on the main shaft of the machine tool.

[0020] The coordinate measurement of each reference point is achieved by using a dial indicator or micrometer in conjunction with a machine tool. The overall operation is simple, and the operator can perform real-time monitoring and adjustment to ensure accurate coordinate measurement of each reference point. At the same time, the professional requirements for the operator are relatively low, which can effectively save the cost of professional training for the operator.

[0021] Furthermore, the journal and the outer circle of the flange of the workpiece are processed in one cut using the same center reference.

[0022] The above arrangement ensures high concentricity between the outer circle of the flange and the outer circle of the shaft section of the workpiece, ensuring that the fixed alignment of the flange end face can be achieved through the fixed alignment of the shaft section of the workpiece, reducing the difficulty of directly aligning the flange end face and improving the overall processing efficiency.

[0023] Furthermore, in step 1, the workpiece is clamped by a V-shaped iron, and the side generatrix of the shaft section of the workpiece is aligned.

[0024] The side generatrix of the workpiece shaft segment is aligned to ensure that the axis of the workpiece is parallel to the machine tool spindle and the flange end face is perpendicular to the machine tool spindle, ensuring the accuracy of the relative position of the workpiece and the machine tool and improving the subsequent processing accuracy.

[0025] Furthermore, in step 1, the workpiece is pre-drilled for pin holes before alignment, and the radial machining allowance of the pin holes after pre-drilling is 1-2 mm.

[0026] Pre-drilling is performed first, followed by rough boring, which provides a certain amount of adjustment space and reduces the risk of one-time processing. If rough boring is performed directly, once a positioning error occurs, the entire workpiece may be scrapped. The alignment process between pre-drilling and rough boring further improves the processing accuracy and reduces the amount of rework. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of a workpiece according to an embodiment of the present invention.

[0028] Figure 2 It is a schematic diagram of the end face of the workpiece flange according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following is further described in detail through specific implementation methods:

[0030] The embodiment is basically as shown in the attached Figure 1 , Figure 2 As shown: This embodiment takes an output shaft workpiece with a flange, and processes a pin hole for external connection on the flange of the workpiece as an example. The position accuracy of the pin hole is φ0.025. A high-precision pin hole processing and alignment method is applied, including the following steps:

[0031] Step 1: The journal and flange outer circle of the workpiece are processed with one cut based on the same center reference. The workpiece is fixed on the machine tool, and the shaft section A and shaft section B of the workpiece are clamped by V-shaped iron. Then, the side generatrix of the two shaft sections of the workpiece are aligned. After the alignment is completed, the machine tool tool rough-bores and rounds the pin holes on the flange end face of the workpiece.

[0032] Among them, the workpiece is pre-drilled for pin holes before alignment. The radial machining allowance of the pin holes after pre-drilling is 1-2mm. Pre-drilling can not only preliminarily determine the position of the pin holes and provide reference points for subsequent boring, but also calibrate the position of the workpiece more accurately and ensure the flatness and verticality of the flange end face, thereby improving the accuracy of the entire processing. If pre-drilling is performed after alignment, the position of the drill hole needs to be re-determined on the aligned workpiece, which will increase the complexity and time cost of the operation, and pre-drilling after alignment may affect the accuracy of the alignment due to vibration and deformation generated during the drilling process. Pre-drilling, as a preliminary positioning, can reduce the impact of these unfavorable factors.

[0033] Step 2: Select any two mutually perpendicular diameters in the flange end face of the workpiece to establish a calibration coordinate system XOY. Preferably, in this embodiment, the Y axis is located in the vertical direction, and the point of the calibration coordinate system coincides with the center of the flange end face. Two calibration reference lines are set along the X axis and the Y axis. Both ends of the calibration reference line pass through the pin hole and its center. The pin hole passed by the calibration reference line is set as the reference hole. Figure 2As shown, there are four reference holes, namely hole A, hole B, hole C and hole D. Hole A is opposite to hole C, and hole B is opposite to hole D. The first or second point where the calibration reference line intersects with the reference hole is the first reference point, and the intersection with the outer circle of the flange is the second reference point; preferably, in this example, the first point where the calibration reference line intersects with the reference hole is used as the reference point, such as Figure 2 As shown, the first reference points are a1, b1, c1 and d1, and the second reference points are a2, b2, c2 and d2.

[0034] Step 3: Measure the coordinates of the first reference point and the second reference point through the machine tool, and calculate the relative displacement value between two adjacent first reference points and the second reference point. Specifically, the dial indicator is adsorbed on the main shaft of the machine tool, and the side head of the dial indicator contacts the outer circle of the flange. When the side head sweeps over point a1, the coordinates on the machine tool (a1x, a1y) are recorded. When the machine tool runs to point a2, the coordinates on the machine tool (a2x, a2y) are recorded. Then, the distance a12 between points a1 and a2 is calculated. The calculation formula is:

[0035]

[0036] Similarly, calculate the distances between b1 and b2, c1 and c2, and d1 and d2, and record them as b12, c12, and d12.

[0037] Step 4: Compare the two relative displacement values ​​at both ends of the same calibration reference line and obtain the difference between the two relative displacement values.

[0038] Step 5. Adjust the center position of the machine tool spindle along the X-axis and Y-axis of the calibration coordinate system according to the two differences obtained in step 4. Determine the adjustment direction of the machine tool spindle along the X-axis or Y-axis according to the positive or negative difference. Half of the absolute value of the difference is the adjustment distance. After adjustment, align the center of the machine tool spindle with the center of the flange end face; then precision bore each pin hole.

[0039] For example: a12=0.2mm, c12=0.4mm, a12-c12=-0.2mm; b12=0.6mm, d12=0.3mm, b12-d12=0.3mm.

[0040] According to the above difference, the machine tool spindle has deviations in both the X-axis and Y-axis directions, and the machine tool spindle is more biased towards the negative direction of the X-axis and the negative direction of the Y-axis, that is, it is more biased towards holes B and C; according to a12-c12=-0.2mm, b12-d12=0.3mm, it is concluded that the adjustment amounts of the machine tool spindle in the Y-axis and X-axis directions are 0.1mm and 0.15mm respectively, that is, the machine tool spindle moves 0.1mm towards hole A and 0.15mm towards hole D, thus achieving alignment of the center of the machine tool spindle with the flange end face.

[0041] The entire embodiment can effectively eliminate the influence caused by factors such as thermal deformation of the machine tool, tool wear, and workpiece clamping error by introducing a calibration coordinate system and accurately determining the coordinates of each reference point, thereby ensuring the alignment accuracy of the machine tool spindle and the center of the flange end face. This high-precision alignment method provides a solid foundation for subsequent fine boring processing, so that the position accuracy of the pin hole meets the processing accuracy standard, significantly improves product quality and processing efficiency, and effectively reduces the amount of workpiece rework. In addition, the rough boring processing and calibration operation are combined. By establishing a calibration coordinate system on the flange end face and using the reference points in the coordinate system for position adjustment, the machine tool spindle and the center of the flange end face of the workpiece are aligned. The whole process is simple and efficient. No complex equipment or tools are required, and only a conventional CNC boring and milling machine is required. This method is easy to implement online on the production line, and operators can master it after simple training, which greatly reduces the technical threshold and improves operability.

[0042] Secondly, this processing method is not only suitable for the processing of output shaft pin holes with flanges, but also for other parts with similar structures, such as the boring and milling of planetary holes of planetary carriers. By establishing corresponding calibration coordinate systems for the flange end faces of different parts and performing alignment and fine boring processing according to the same method, it can be widely used in various mechanical manufacturing fields to solve similar problems. The versatility and flexibility of this method make it an efficient solution that meets the needs of various application scenarios.

[0043] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A high-precision pin hole processing and alignment method, characterized in that: The following steps are involved: Step 1: Fix the workpiece on the machine tool, and rough bore each pin hole on the flange end face of the workpiece until it is round; Step 2. Select any two mutually perpendicular diameters in the flange end face of the workpiece to establish a calibration coordinate system XOY. The point of the calibration coordinate system coincides with the center of the flange end face. Set a calibration reference line along the X-axis and the Y-axis. Both ends of the calibration reference line pass through the pin hole and the center of the pin hole. The pin hole passed by the calibration reference line is set as the reference hole. The first point where the calibration reference line intersects with the reference hole is the first reference point, and the intersection with the outer circle of the flange is the second reference point. Step 3, measuring the coordinates of the first reference point and the second reference point by a machine tool, and calculating the relative displacement value between two adjacent first reference points and the second reference point; Step 4: compare the two relative displacement values ​​at both ends of the same calibration reference line, and obtain the difference between the two relative displacement values; Step 5: According to the two differences obtained in step 4, adjust the center position of the machine tool spindle along the X-axis and Y-axis of the calibration coordinate system, and then fine bore each pin hole.

2. A high-precision pin hole processing and alignment method according to claim 1, characterized in that: In step 1, the second point where the calibration reference line intersects the reference hole is the first reference point.

3. A high-precision pin hole machining and alignment method according to any one of claims 1 or 2, characterized in that: In step 3, the coordinates of the first reference hole and the second reference hole are measured by the machine tool and the measuring indicator.

4. A high-precision pin hole machining and alignment method according to claim 3, characterized in that: The measuring indicator is a dial indicator or a micrometer, and the measuring indicator is adsorbed on the main shaft of the machine tool.

5. A high-precision pin hole machining and alignment method according to claim 4, characterized in that: The shaft neck and flange outer circle of the workpiece are processed in one cut using the same center reference.

6. A high-precision pin hole machining and alignment method according to claim 5, characterized in that: In step 1, the workpiece is clamped by a V-shaped iron, and the side generatrix of the shaft section of the workpiece is aligned.

7. A high-precision pin hole machining and alignment method according to claim 6, characterized in that: In step 1, the pin hole is pre-drilled before the workpiece is aligned, and the radial machining allowance of the pin hole after pre-drilling is 1-2 mm.

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