Grinding method for cambered surface soft belt of main bearing ring

Abstract

The invention relates to the technical field of main bearing machining, in particular to a main bearing ring cambered surface soft belt polishing method which comprises the following steps: determining polishing paths, namely a first linear path, an arc path and a second linear path; and a robot is adopted to control a first polishing piece to polish the cambered surface soft belt area in a reciprocating mode according to the first linear path, the arc path and the second linear path. The problems that in the prior art, manual polishing is long in consumed time, low in productivity and low in precision can be solved, and polishing of cambered surface soft belt areas of main bearing rings of different sizes and models can be completed. In addition, the robot is adopted for controlling grinding, the problem that dust generated by manual grinding harms health is solved, and the problems that cost is high and occupied space is large due to the fact that a machine tool is adopted for grinding can also be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of main bearing processing, in particular to a main bearing ring arc surface soft band polishing method. BACKGROUND

[0002] In the quenching process of the main bearing raceway of the heading machine, a quenching blind area will appear at the connection between the beginning and the end, which is also called a soft band. The hardness of the raceway after normal quenching is generally 58-62HRC, while the hardness of the soft band area is generally about 35HRC. Therefore, the soft band is the weakest area of the main bearing raceway. When the main bearing is working normally, the bearing roller will generate a large force when rolling in the raceway, and the soft band has weak resistance to the rolling and alternating load. Under the action of the alternating load for a long time, the soft band area will fail first, so the main bearing soft band area needs to be polished; the polished main bearing soft band area avoids the contact and stress of the bearing roller in the area in the form of clearance fit.

[0003] Considering that the soft band area of the main bearing will have a soft and hard junction, when the soft and hard junction reaches the polishing requirement, the polishing depth of other areas of the soft band may have exceeded the maximum value of the set polishing depth. How to make the polishing depth of the soft and hard junction and other areas in the soft band area consistent and meet the set polishing depth is a difficulty in polishing the soft band area. At present, the polishing of the soft band of the bearing raceway is still mainly manual polishing. The polishing depth of the raceway soft band is generally 0.2-0.5mm, and it is difficult to accurately control the grinding depth and surface roughness when manually polishing with a handheld polisher. In addition, manual polishing has the problems of high labor intensity, low work efficiency, low safety, poor protection, poor product consistency, etc., and it is difficult to ensure the polishing quality of the soft band, especially for the polishing of the soft band of a large main bearing ring, which consumes a long time and seriously restricts the production capacity, and the dust generated in the grinding process affects human health. In addition, the main bearing of the heading machine is relatively large in size, and if a machine tool is used for grinding, a large special machine tool needs to be customized to meet the machining conditions, which has high cost investment and occupies a large space.

[0004] In summary, a main bearing ring arc surface soft band polishing method needs to be developed to solve the problems of long time consumption, low production capacity, low precision and dust hazards to health in manual polishing in the prior art, and to solve the problems of high cost and large space occupation caused by machine tool grinding. SUMMARY

[0005] The present application aims to provide a main bearing ring arc surface soft band polishing method, and the specific technical solutions are as follows: A main bearing ring arc surface soft band polishing method is used for polishing the radial arc surface soft band area of the main bearing ring raceway, which comprises the following steps: Step S1, determining a polishing path; Firstly, the arc surface soft band region is divided into a soft band middle region and soft band transition regions; the soft band transition regions are two and are respectively located on the left end and the right end of the soft band middle region; the hardness of the soft band transition regions is greater than the hardness of the soft band middle region; Secondly, a middle point of the soft band middle region is marked as a polishing site M3, a left end point and a right end point of the soft band middle region are marked as polishing sites M2 and M4 respectively, a left end point of the soft band transition region on the left end of the soft band middle region is marked as a polishing site M1, and a right end point of the soft band transition region on the right end of the soft band middle region is marked as a polishing site M5; wherein a first straight line path is adopted for polishing in the region from the polishing site M1 to the polishing site M2, an arc line path is adopted for polishing in the region from the polishing site M2 to the polishing site M4, and a second straight line path is adopted for polishing in the region from the polishing site M4 to the polishing site M5; Step S2, a first polishing piece is controlled by a robot to reciprocatingly polish the arc surface soft band region according to the first straight line path, the arc line path and the second straight line path; when the polishing depth of the soft band middle region and the soft band transition region is the target depth H, the polishing is stopped; wherein the feeding speed of the first polishing piece on the first straight line path and the feeding speed on the second straight line path are 1 / 3-1 / 2 times of the feeding speed on the arc line path.

[0006] Optionally, the chord length corresponding to the soft band middle region is A, the chord length corresponding to the soft band transition region is B, and the chord length corresponding to the arc surface soft band region is L; A two-dimensional coordinate system is established with the polishing site M3 as the coordinate origin, wherein the center direction of the polishing site M3 to the radial direction of the main bearing sleeve ring is the positive direction of the X axis, and the direction of the polishing site M3 to the soft band transition region on the right side thereof is the positive direction of the Y axis; the coordinates of the polishing sites M1 to M5 are recorded as (x1, y0-L / 2), (x2, y0-A / 2), (x0, y0), (x2, y0+A / 2) and (x1, y0+L / 2) in sequence; the values of x1 and x2 are obtained through measurement; The coordinates of the polishing sites M1 to M5 are introduced into the control program of the robot, the first straight line equation, i.e. the first straight line path, is determined in combination with the polishing site M1 (x1, y0-L / 2) and the polishing site M2 (x2, y0-A / 2); the circular arc equation, i.e. the arc line path, is determined in combination with the polishing site M2 (x2, y0-A / 2), the polishing site M4 (x2, y0+A / 2) and the center coordinate (x3, y0); wherein the value of x3 is obtained through measurement; the second straight line equation, i.e. the second straight line path, is determined in combination with the polishing site M4 (x2, y0+A / 2) and the polishing site M5 (x1, y0+L / 2).

[0007] Optionally, the chord length L is 80-120mm; the chord length A is 50-80mm; and the chord length B is 15-20mm.

[0008] Optionally, in the first straight path polishing, the electric spindle speed of the first polishing piece is 3000-5000r / min, the feed speed is 10-30mm / s, and the grinding amount is 0.02-0.05mm / time.

[0009] Optionally, in the second straight path polishing, the electric spindle speed of the first polishing piece is 3000-5000r / min, the feed speed is 10-30mm / s, and the grinding amount is 0.02-0.05mm / time.

[0010] Optionally, in the arc path polishing, the electric spindle speed of the first polishing piece is 3000-5000r / min, the feed speed is 20-50mm / s, and the grinding amount is 0.01-0.03mm / time.

[0011] Optionally, the target depth H is 0.3-0.4mm.

[0012] Optionally, the main bearing ring arc surface soft belt polishing method further comprises post-processing; the post-processing comprises polishing the entire arc surface soft belt area by using the second polishing piece and the third polishing piece in turn under the control of the robot.

[0013] Optionally, the electric spindle speed of the second polishing piece is 3000-5000r / min, the feed speed is 30-50mm / s, and the grinding amount is 0.003-0.005mm / time.

[0014] Optionally, the electric spindle speed of the third polishing piece is 3000-5000r / min, the feed speed is 40-50mm / s, and the grinding amount is 0.001-0.003mm.

[0015] The technical scheme of the application has at least the following beneficial effects: The application provides a main bearing ring arc surface soft band polishing method, first, the arc surface soft band region is divided into a soft band middle region and a soft band transition region by adopting step S1, the soft band transition region is two and is located on the left end and the right end of the soft band middle region respectively, wherein the hardness of the soft band transition region is greater than that of the soft band middle region, and there is a soft and hard junction point between the two; the first linear path, the arc line path and the second linear path to be polished are sequentially determined through polishing points M1 to M5; secondly, the first polishing piece is reciprocally polished along the first linear path, the arc line path and the second linear path in step S2 by adopting the robot control; when the polishing depth of the soft band middle region and the soft band transition region is the target depth H, the polishing is stopped, wherein the feeding speed of the first polishing piece on the first linear path and the feeding speed on the second linear path are 1 / 3-1 / 2 times of the feeding speed on the arc line path, on the one hand, the soft and hard junction point in the arc surface soft band region can be quickly polished, on the other hand, the soft band transition region and the soft band middle region can be quickly and high-precision polished to the target depth H, and on the other hand, the polishing of the arc surface soft band region of the main bearing ring of different sizes and models can be completed. Therefore, the application can not only solve the problems of long time consumption, low production capacity and low precision in the manual polishing in the prior art, but also complete the polishing of the arc surface soft band region of the main bearing ring of different sizes and models. In addition, the polishing by the robot control can not only solve the problem of dust harm to health caused by manual polishing, but also solve the problems of high cost and large space occupation caused by machine tool grinding.

[0016] In addition to the objects, features and advantages described above, the application has other objects, features and advantages. The application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings that form a part of this application are intended to provide a further understanding of the application, and the illustrative embodiments of the application and their description serve to explain the application without imposing undue limitation on the application. In the drawings: Fig. 1 is a structural schematic view of the main bearing ring in the embodiment of the application; Fig. 2 is a structural schematic view of the arc surface soft band region polishing point and the polishing path mark in the embodiment of the application; Fig. 3 is a structural schematic view of the arc surface soft band region after polishing in the embodiment of the application; wherein 100 is a main bearing ring. DETAILED DESCRIPTION

[0018] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art belong to the scope of protection of the present application.

[0019] Embodiment: Referring to Figs. 1-3 A main bearing ring arc surface soft band polishing method is used for polishing the arc surface soft band area of the raceway of a main bearing ring 100 in the radial direction, and comprises the following steps. Step S1, determining a polishing path; Firstly, the arc surface soft band area is divided into a soft band middle area and a soft band transition area; the soft band transition area is two, and is located on the left end and the right end of the soft band middle area respectively; the hardness of the soft band transition area is greater than that of the soft band middle area, and there is a soft-hard junction point between them; Secondly, the middle point of the soft band middle area is marked as a polishing point M3, the left end point and the right end point of the soft band middle area are marked as polishing points M2 and M4 respectively, the left end point of the soft band transition area on the left end of the soft band middle area is marked as a polishing point M1, and the right end point of the soft band transition area on the right end of the soft band middle area is marked as a polishing point M5; wherein a first straight line path is adopted for polishing in the area from the polishing point M1 to the polishing point M2, an arc line path is adopted for polishing in the area from the polishing point M2 to the polishing point M4, and a second straight line path is adopted for polishing in the area from the polishing point M4 to the polishing point M5; Step S2, a first polishing piece (specifically a diamond grinding wheel, material is electroplated CBN) is controlled by a robot to reciprocatingly polish the arc surface soft band area according to the first straight line path, the arc line path and the second straight line path, specifically, the reciprocating polishing mode from the polishing point M1 to the polishing point M5 and then from the polishing point M5 to the polishing point M1 is adopted for polishing; when the polishing depth of the soft band middle area and the soft band transition area is the target depth H, the polishing is stopped; wherein the feeding speed of the first polishing piece on the first straight line path and the feeding speed on the second straight line path are 0.375 times of the feeding speed on the arc line path, which is considering that a smaller feeding speed is needed in the soft band transition area with greater hardness, i.e. the first straight line path and the second straight line path, to ensure that the polishing depth is met, and a larger feeding speed is needed in the soft band middle area with smaller hardness, i.e. the arc line path, to avoid over-polishing.

[0020] The chord length corresponding to the soft band intermediate region is A (the value of the chord length A is 50 mm), the chord length corresponding to the soft band transition region is B (the value of the chord length B is 15 mm), and the chord length corresponding to the arc surface soft band region is L (the value of the chord length L is 80 mm); A two-dimensional coordinate system is established with the polishing site M3 as the coordinate origin, wherein the center direction of the circle of the polishing site M3 radially towards the main bearing ring 100 is the positive direction of the X axis, and the direction of the soft band transition region to the right of the polishing site M3 is the positive direction of the Y axis; the coordinates of the polishing sites M1 to M5 are recorded as (x1, y0-L / 2), (x2, y0-A / 2), (x0, y0), (x2, y0+A / 2) and (x1, y0+L / 2) in sequence; the values of x1 and x2 are obtained by measurement; The coordinates of the polishing sites M1 to M5 are introduced into the control program (existing program) of the robot, and the first straight line equation, i.e., the first straight line path, is determined in combination with the polishing site M1 (x1, y0-L / 2) and the polishing site M2 (x2, y0-A / 2); the circular arc equation, i.e., the arc line path, is determined in combination with the polishing site M2 (x2, y0-A / 2), the polishing site M4 (x2, y0+A / 2) and the center coordinate (x3, y0); wherein the value of x3 is obtained by measurement; and the second straight line equation, i.e., the second straight line path, is determined in combination with the polishing site M4 (x2, y0+A / 2) and the polishing site M5 (x1, y0+L / 2).

[0021] In the polishing of the first straight line path, the rotational speed of the electric spindle of the first polishing piece is 5000 r / min, the feed speed is 15 mm / s, and the grinding amount is 0.03 mm / time.

[0022] In the polishing of the second straight line path, the rotational speed of the electric spindle of the first polishing piece is 5000 r / min, the feed speed is 15 mm / s, and the grinding amount is 0.03 mm / time.

[0023] In the polishing of the arc line path, the rotational speed of the electric spindle of the first polishing piece is 5000 r / min, the feed speed is 40 mm / s, and the grinding amount is 0.02 mm / time.

[0024] The soft band intermediate region is polished to a target depth H of 0.4 mm, and the soft band transition region is polished to a target depth H of 0.3 mm.

[0025] The main bearing ring arc surface soft band polishing method further comprises post-processing; the post-processing comprises sequentially adopting a robot to control a second polishing piece (specifically, a thousand-leaf wheel, and the material is sandpaper) and a third polishing piece (specifically, a polishing wheel, and the material is fiber) to polish the entire arc surface soft band area. Specifically, the polishing path of the second polishing piece in polishing is polishing twice in the direction from M1 to M5, which is used to improve the roughness of the arc surface soft band area L to meet the requirement; wherein the shape of the thousand-leaf wheel is that a plurality of sandpapers are spliced in the same direction, and the polishing is performed in the reverse direction of the sandpaper splicing direction, the sandpaper may be fluffy, and the polishing effect is poor, so the polishing of the thousand-leaf wheel in this embodiment is performed in the direction of the sandpaper splicing direction, that is, in the direction from M1 to M5. The polishing path of the third polishing piece in polishing is reciprocating polishing once from M1 to M5 and then from M5 to M1, which is used to remove the tiny impurities of the arc surface soft band area L and improve the smoothness and brightness of the arc surface soft band area L.

[0026] The electric spindle speed of the second polishing piece is 4000 r / min, the feed speed is 40 mm / s, and the grinding amount is 0.003 mm / time.

[0027] The electric spindle speed of the third polishing piece is 3000 r / min, the feed speed is 50 mm / s, and the grinding amount is 0.001 mm.

[0028] The embodiment adopts the combined polishing path of the first straight line path, the arc line path and the second straight line path, and controls the differential setting of the feed speed, which can quickly polish the soft-hard junction in the arc surface soft band area on one hand, and quickly and accurately polish the soft band transition area and the soft band middle area to the target depth H on the other hand, and can also complete the polishing of the arc surface soft band area of the main bearing ring 100 of different sizes on the other hand. The embodiment adopts post-processing to improve the accuracy, roughness, smoothness and brightness of the polishing of the arc surface soft band area of the main bearing ring 100.

[0029] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for grinding the arc-shaped soft strip of a main bearing raceway, used to grind the radial arc-shaped soft strip area of ​​the raceway of a main bearing raceway, characterized in that... include: Step S1: Determine the polishing path; First, the curved soft strip region is divided into a soft strip middle region and a soft strip transition region; there are two soft strip transition regions, located at the upper left and upper right ends of the soft strip middle region, respectively; the hardness of the soft strip transition region is greater than the hardness of the soft strip middle region; Next, the midpoint of the middle region of the soft strip is marked as grinding point M3, the left and right endpoints of the middle region of the soft strip are marked as grinding point M2 and grinding point M4 respectively, the left endpoint of the soft strip transition region on the left end of the middle region of the soft strip is marked as grinding point M1, and the right endpoint of the soft strip transition region on the right end of the middle region of the soft strip is marked as grinding point M5; wherein, the region from grinding point M1 to grinding point M2 is ground using a first straight path, the region from grinding point M2 to grinding point M4 is ground using an arc path, and the region from grinding point M4 to grinding point M5 is ground using a second straight path; Step S2: The robot controls the first grinding component to reciprocate grinding the curved soft strip area along the first straight path, the arc path, and the second straight path; when the grinding depth of the middle area of ​​the soft strip and the transition area of ​​the soft strip are both the target depth H, the grinding is stopped; wherein, the feed speed of the first grinding component on the first straight path and the feed speed on the second straight path are both 1 / 3 to 1 / 2 times the feed speed on the arc path.

2. The method for grinding the arc surface of the main bearing ring according to claim 1, characterized in that, The chord length corresponding to the middle region of the flexible strip is A, the chord length corresponding to the transition region of the flexible strip is B, and the chord length corresponding to the arc-shaped flexible strip region is L. A two-dimensional coordinate system is established with the grinding point M3 as the origin. The positive X-axis is the direction from the grinding point M3 toward the radial center of the main bearing ring, and the positive Y-axis is the direction from the grinding point M3 toward the soft strip transition area to its right. The coordinates of the grinding points M1 to M5 are recorded as (x1, y0-L / 2), (x2, y0-A / 2), (x0, y0), (x2, y0+A / 2), and (x1, y0+L / 2), respectively. The values ​​of x1 and x2 are obtained through measurement. The coordinates of grinding points M1 to M5 are imported into the robot's control program. The first straight line equation, i.e., the first straight line path, is determined by combining grinding points M1 (x1, y0-L / 2) and grinding points M2 (x2, y0-A / 2). The arc equation, i.e., the arc path, is determined by combining grinding points M2 (x2, y0-A / 2), grinding points M4 (x2, y0+A / 2), and the center coordinates (x3, y0). The value of x3 is obtained through measurement. The second straight line equation, i.e., the second straight line path, is determined by combining grinding points M4 (x2, y0+A / 2) and grinding points M5 (x1, y0+L / 2).

3. The method for grinding the arc surface of the main bearing ring according to claim 2, characterized in that, The chord length L is 80~120mm; the chord length A is 50~80mm; and the chord length B is 15~20mm.

4. The method for grinding the arc surface of the main bearing ring according to claim 1, characterized in that, In the first linear path grinding, the electric spindle speed of the first grinding workpiece is 3000-5000 r / min, the feed rate is 10~30 mm / s, and the grinding amount is 0.02~0.05 mm / time.

5. The method for grinding the arc surface of the main bearing ring according to claim 1, characterized in that, In the second linear path grinding, the electric spindle speed of the first grinding part is 3000-5000 r / min, the feed rate is 10~30 mm / s, and the grinding amount is 0.02~0.05 mm / time.

6. The method for grinding the arc surface of the main bearing ring according to claim 1, characterized in that, In the arc path grinding, the electric spindle speed of the first grinding part is 3000-5000 r / min, the feed rate is 20~50 mm / s, and the grinding amount is 0.01~0.03 mm / time.

7. The method for grinding the arc surface of the main bearing ring according to claim 1, characterized in that, The target depth H is 0.3~0.4mm.

8. The method for grinding the arc surface of the main bearing ring according to any one of claims 1-7, characterized in that, It also includes post-processing; the post-processing includes sequentially using a robot-controlled second and third grinding tools to grind the entire curved soft strip area.

9. The method for grinding the arc surface of the main bearing ring according to claim 8, characterized in that, The electric spindle using the second grinding element has a rotational speed of 3000-5000 r / min, a feed rate of 30-50 mm / s, and a grinding depth of 0.003-0.005 mm / cycle.

10. The method for grinding the arc surface of the main bearing ring according to claim 8, characterized in that, The electric spindle using the third grinding element has a rotational speed of 3000-5000 r / min, a feed rate of 40-50 mm / s, and a grinding depth of 0.001-0.003 mm.

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