A kind of ultra-high precision roller thin-wall steel sleeve stress relieving device before grinding and grinding method

Abstract

The present application relates to the technical field of heat treatment stress relieving equipment, in particular to a kind of ultra-high-precision roller thin-walled steel sleeve pre-grinding stress relieving device and grinding method.The pre-grinding stress relieving device includes a pair of supporting positioning blocks fixedly arranged for supporting the outer circle of the thin-walled steel sleeve of the two ends of the roller, and a rotary drive device for driving the roller to rotate on the pair of supporting positioning blocks.The present application realizes ultra-high-precision grinding of the outer circle of the thin-walled steel sleeve, and the grinding size precision of the outer circle of the thin-walled steel sleeve is within ±0.001mm.

Description

Technical Field

[0001] This invention relates to the field of heat treatment stress relief equipment technology, specifically to a stress relief device and grinding method for ultra-high precision thin-walled steel sleeves of rolling mill rolls before grinding. Background Technology

[0002] High-precision thin-walled steel sleeves are difficult-to-machine parts, and their main machining challenges are as follows:

[0003] First, stress is generated inside the steel sleeve at each stage from blank production to machining. The presence of stress will cause the thin-walled steel sleeve to deform after processing, ultimately leading to the roundness and dimensional deviation of the steel sleeve.

[0004] Secondly, the steel sleeve has a thin wall thickness, which makes it easy to deform after clamping. Therefore, when the clamping is loosened after processing, the roundness and size of the steel sleeve will be out of tolerance due to the recovery of deformation.

[0005] To reduce roundness and dimensional errors after machining thin-walled steel sleeves, existing technologies typically incorporate several heat treatment stress-relieving processes and / or cold treatment stabilization processes during the intermediate stages of thin-walled steel sleeve manufacturing. This significantly reduces the internal stress on the thin-walled steel sleeve. Furthermore, in the final stage of machining, the use of specialized steel sleeve positioning fixtures (such as self-expanding mandrels, 1:5000 taper mandrels, etc.) can significantly reduce clamping deformation and improve machining accuracy.

[0006] To further improve the machining accuracy of thin-walled steel sleeves, a better machining method is to fit the steel sleeve onto the shaft with an interference fit, and then grind the outer diameters of both the shaft and the steel sleeve together. This improves both the machining accuracy of the outer diameter of the steel sleeve and the coaxiality of the outer diameter of the steel sleeve and the outer diameter of the shaft that are ground together.

[0007] like Figure 1 Thin-walled steel sleeves are provided on the outer diameter of the shaft ends of the roll 1. The thin-walled steel sleeves are fitted onto the roll with an interference fit and then ground. The outer diameter of the steel sleeves is ground on an ultra-high precision CNC cylindrical grinding machine. The outer diameter dimensional accuracy is ±0.005mm. Although it has reached a very high accuracy index, it still cannot meet the ultra-high precision requirement of ±0.001mm required by the customer.

[0008] Based on the above situation, after technical research and analysis on the grinding accuracy of thin-walled steel sleeves, we found that although the thin-walled steel sleeves are ground together after being fitted onto the outer diameters of both ends of the roll with an interference fit, the presence of uneven stress inside the thin-walled steel sleeve causes a redistribution of this uneven stress during the grinding process, as the grinding allowance is removed. This results in uneven micro-deformation of the sleeve's wall thickness. Therefore, to further improve the grinding accuracy of the outer diameter of the thin-walled steel sleeve, it is necessary to find ways to further reduce the internal stress of the thin-walled steel sleeve before grinding. Summary of the Invention

[0009] To address the aforementioned problems, this invention proposes a stress-relieving device and grinding method for ultra-high precision thin-walled steel sleeves before grinding, aiming to achieve ultra-high precision grinding of the outer diameter of the thin-walled steel sleeve. The specific technical solution is as follows:

[0010] A stress relief device for ultra-high precision thin-walled steel sleeves of rolling mills before grinding includes a pair of fixed support positioning blocks for supporting the outer circles of the thin-walled steel sleeves at both ends of the rolling mill, and a rotary drive device for driving the rolling mill to rotate on the pair of support positioning blocks.

[0011] Preferably, the support positioning block is a V-shaped block, and the V-shaped support surface of the V-shaped block is filled with lubricating grease.

[0012] Preferably, a friction-reducing plate is provided on the V-shaped support surface of the V-block, and the lubricating grease is injected onto the support surface of the friction-reducing plate.

[0013] In this invention, the rotary drive device includes a fixedly mounted drive motor and a roll connecting fixture disposed between the output shaft of the drive motor and one end of the roll.

[0014] Preferably, the drive motor is a geared motor or a variable frequency motor.

[0015] Preferably, the roll connecting fixture includes an active dial fixed on the output shaft of the drive motor, a driven dial fixed on the end of the roll, and a pin connecting the active dial and the driven dial.

[0016] Preferably, one end of the pin is fixedly connected to one of the active and passive dials, and the other end of the pin is connected to the shaft of the other dial.

[0017] To fix the driven dial to the end of the roll, process screw holes can be machined on the end face of the roll, and then the driven dial can be fixed to the end face of the roll with screws.

[0018] Preferably, the pin is a hinged bolt, one end of which is threaded and connected to one of the active and driven dials, and the other end of which is hinged and connected to the hole of the other dial. A limiting spacer sleeve is also provided between the active and driven dials, which is fitted onto the hinged outer circle of the hinged bolt.

[0019] Preferably, the hinge bolt and the hole shaft of the dial are fitted with a clearance fit.

[0020] Preferably, the hole on the dial that is clearance-fitted with the hinge bolt is a slotted hole to compensate for the misalignment error between the output shaft of the drive motor and the roll.

[0021] Preferably, the roller connecting fixture can also be a universal coupling connected between the output shaft of the drive motor and the shaft end of one end of the roller.

[0022] Preferably, the universal joint is connected between the driving dial and the driven dial.

[0023] Preferably, the base is provided with a lifting platform, and the drive motor is fixed on the lifting platform to improve the adaptability of the output shaft of the drive motor to docking with rolls of different specifications.

[0024] The present invention provides a stress relief device for ultra-high precision thin-walled steel sleeve rolling mill before grinding, which further includes a base and a guide rail groove disposed on the base, and a T-shaped groove disposed on the base and parallel to the guide rail groove. The pair of support positioning blocks are movably disposed on the guide rail groove and are fixedly connected to the base by T-bolts and nuts disposed on the T-shaped groove.

[0025] By moving a pair of support positioning blocks onto the guide rail groove, the support positioning of rolls of different lengths can be achieved.

[0026] A grinding method for a stress-relieving device before grinding ultra-high precision thin-walled steel sleeve rolls includes the following steps:

[0027] (1) Steel sleeve pre-processing: Thin-walled steel sleeves are pre-processed separately; the inner hole and two end faces of the thin-walled steel sleeve are machined to the required dimensions, and the outer circle of the thin-walled steel sleeve is left with grinding allowance;

[0028] (2) Steel sleeve assembly: The pre-processed thin-walled steel sleeve is installed on the outer circle of the end of the roll using a hot fitting method. After the steel sleeve is assembled, an interference fit is formed between the inner hole of the thin-walled steel sleeve and the outer circle of the end of the roll.

[0029] (3) Steel sleeve stress relief treatment: The roll with the thin-walled steel sleeve installed is hoisted onto a pair of support positioning blocks on the stress relief device. One end of the roll is connected to the rotary drive device through the roll connecting fixture. The rotary drive device is turned on to drive the roll to rotate continuously for a period of time. Under the action of the roll's own weight, the thin-walled steel sleeve at the end of the roll is pressed on the support positioning block and rotates continuously under pressure, so that the internal stress of the thin-walled steel sleeve is released.

[0030] (4) Steel sleeve grinding: A high-precision cylindrical grinding machine is used to grind the outer diameter of the thin-walled steel sleeve at the end of the roll.

[0031] As a further improvement to the grinding method of the high-precision roll thin-walled steel sleeve pre-grinding stress relief device in this invention, the rotary drive device adopts a variable frequency motor controlled by a controller. The steel sleeve stress relief treatment in step (3) is carried out in two stages. The first stage is constant speed rotation stress relief. Under the control of the controller, the variable frequency motor drives the roll to rotate at a constant speed for several hours. After reaching the set time, it enters the second stage of gradual deceleration rotation stress relief. Under the control of the controller, the variable frequency motor drives the roll to rotate at a gradual deceleration for several hours until the minimum speed is reached and then the rotation stops.

[0032] The beneficial effects of this invention are:

[0033] First, the present invention provides a stress relief device and grinding method for ultra-high precision thin-walled steel sleeves of rolling mills before grinding. By using the weight of the rolling mill itself as the force, and in conjunction with the support positioning block and the rotary drive device, the thin-walled steel sleeves, which are fitted onto the outer circles of both ends of the rolling mill in an interference fit manner, are continuously rotated and pressed. This eliminates the internal stress of the thin-walled steel sleeves, thereby improving the grinding dimensional accuracy of the outer circle of the thin-walled steel sleeves from ±0.005mm to ±0.001mm, thus achieving ultra-high precision grinding of the outer circle of the thin-walled steel sleeves.

[0034] Secondly, the present invention provides a stress relief device and grinding method for ultra-high precision thin-walled steel sleeves before grinding. The horizontal spacing of the support positioning blocks on the stress relief device before grinding is adjustable, and the height of the drive motor is adjustable, which has good versatility. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a stress relief device for ultra-high precision thin-walled steel sleeves of rolling mills before grinding, according to the present invention.

[0036] Figure 2 yes Figure 1 Left view (located in) Figure 1 (Cross-sectional view of the left support positioning block portion).

[0037] In the diagram: 1. Roll, 2. Thin-walled steel sleeve, 3. Support positioning block, 4. Rotary drive device, 5. Friction reducing plate, 6. Drive motor, 7. Roll connecting fixture, 8. Output shaft, 9. Active dial, 10. Driven dial, 11. Pin (hinged bolt), 12. Screw, 13. Limiting spacer, 14. Base, 15. Guide rail groove, 16. T-slot, 17. T-bolt, 18. Nut, 19. Lifting platform. Detailed Implementation

[0038] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0039] Example 1:

[0040] like Figures 1 to 2 The figure shows an embodiment of a stress relief device for ultra-high precision thin-walled steel sleeves of a rolling mill before grinding according to the present invention, which includes a pair of support positioning blocks 3 fixedly arranged for supporting the outer circle of the thin-walled steel sleeves 2 at both ends of the rolling mill 1, and a rotary drive device 4 for driving the rolling mill 1 to rotate on the pair of support positioning blocks 3.

[0041] Preferably, the support positioning block 3 is a V-shaped block, and the V-shaped support surface of the V-shaped block is filled with lubricating grease.

[0042] Preferably, a friction-reducing plate 5 is provided on the V-shaped support surface of the V-block, and the lubricating grease is injected onto the support surface of the friction-reducing plate 5.

[0043] In this embodiment, the rotary drive device 4 includes a fixedly installed drive motor 6 and a roll connecting fixture 7 disposed between the output shaft of the drive motor 6 and one end of the roll 1.

[0044] Preferably, the drive motor 6 is a geared motor or a variable frequency motor.

[0045] Preferably, the roll connecting fixture 7 includes an active dial 9 fixed on the output shaft 8 of the drive motor 6, a driven dial 10 fixed at the end of the roll 1, and a pin 11 connecting the active dial 9 and the driven dial 10.

[0046] Preferably, one end of the pin 11 is fixedly connected to one of the active dial 9 and the driven dial 10, and the other end of the pin 11 is connected to the other dial 11 or the driven dial 10 through a shaft engagement.

[0047] In order to fix the driven dial 10 to the end of the roll 1, a process screw hole can be machined on the end face of the roll 1, and then the driven dial 10 can be fixed to the end face of the roll by screw 12.

[0048] Preferably, the pin 11 is a hinged bolt, one end of which is threaded and connected to one of the active dial 9 and the driven dial 10, and the other end of which is hinged and connected to the hole shaft of the other dial 10 or 11. A limiting spacer 13 is also provided between the active dial 9 and the driven dial 10, which is sleeved on the hinged outer circle of the hinged bolt 11.

[0049] Preferably, the hinge bolt 11 is fitted with the hole shaft of the dial 9 or 10 in a clearance fit.

[0050] Preferably, the hole on the dial 9 or 10 that is clearance-fitted with the hinge bolt 11 is a waist-shaped hole to compensate for the misalignment error between the output shaft 8 of the drive motor 6 and the roller 1.

[0051] Preferably, the roller connecting fixture 7 can also be a universal coupling connected between the output shaft 8 of the drive motor 6 and one end of the roller 1.

[0052] Preferably, the universal joint is connected between the driving dial 9 and the driven dial 10.

[0053] Preferably, a lifting platform 19 is provided on the base 14, and the drive motor 6 is fixed on the lifting platform 19 to improve the adaptability of the output shaft 8 of the drive motor 6 to dock with rollers 1 of different specifications.

[0054] The ultra-high precision roll thin-walled steel sleeve pre-grinding stress relief device of this embodiment also includes a base 14 and a guide rail groove 15 disposed on the base 14, and a T-shaped groove 16 disposed on the base 14 and parallel to the guide rail groove 15. The pair of support positioning blocks 3 are movably disposed on the guide rail groove 15 and are fixedly connected to the base 14 by T-bolts 17 and nuts 18 disposed on the T-shaped groove 16.

[0055] By moving a pair of support positioning blocks 3 onto the guide rail groove 15, the support positioning of rolls 1 of different lengths can be satisfied.

[0056] Example 2:

[0057] A grinding method using the stress-relieving device for ultra-high precision thin-walled steel sleeves of rolling mills according to Example 1 includes the following steps:

[0058] (1) Steel sleeve pre-processing: Thin-walled steel sleeve 2 is pre-processed separately; wherein, the inner hole and two end face dimensions of thin-walled steel sleeve 2 are processed to the required size, and the outer circle of thin-walled steel sleeve is left with grinding allowance;

[0059] (2) Steel sleeve assembly: The pre-processed thin-walled steel sleeve 2 is installed on the outer end of the roll 1 by heat fitting. After assembly, the steel sleeve 2 forms an interference fit between the inner hole of the thin-walled steel sleeve 2 and the outer end of the roll 1.

[0060] (3) Steel sleeve stress relief treatment: The roll 1 with thin-walled steel sleeve 2 installed is hoisted onto a pair of support positioning blocks 3 on the stress relief device. One end of the roll 1 is connected to the rotary drive device 4 through the roll connecting tool 7. The rotary drive device 4 is turned on to drive the roll 1 to rotate continuously for a period of time. Under the action of the roll 1's own weight, the thin-walled steel sleeve 2 at the end of the roll 1 is pressed on the support positioning block 3 and rotates continuously under pressure, so that the internal stress of the thin-walled steel sleeve 2 is released.

[0061] (4) Steel sleeve grinding: A high-precision cylindrical grinding machine is used to grind the outer circle of the thin-walled steel sleeve 2 at the end of the roll 1.

[0062] As a further improvement to the grinding method of the high-precision roll thin-walled steel sleeve pre-grinding stress relief device in this embodiment, the rotary drive device 4 adopts a variable frequency motor controlled by a controller. The steel sleeve stress relief treatment in step (3) is carried out in two stages. The first stage is constant speed rotation stress relief. Under the control of the controller, the variable frequency motor drives the roll to rotate at a constant speed for several hours. After reaching the set time, it enters the second stage of gradual deceleration rotation stress relief. Under the control of the controller, the variable frequency motor drives the roll to rotate at a gradual deceleration for several hours until it stops rotating at the lowest speed.

[0063] Example 3:

[0064] Using the grinding method in steps (1) to (4) of Example 2, the thin-walled steel sleeve 2 used in a lithium battery industry is subjected to steel sleeve pre-processing, steel sleeve assembly, steel sleeve stress relief treatment and steel sleeve grinding in sequence; wherein, in the steel sleeve stress relief treatment process in step (3), the rotation drive device 4 is turned on to drive the roll to rotate continuously for 12 hours, and after the steel sleeve grinding process in step (4) is completed, the dimensional accuracy error of the outer circle of the thin-walled steel sleeve is ±0.001mm.

[0065] Example 4:

[0066] After the thin-walled steel sleeve is fitted onto the roll with an interference fit, the outer diameter of the steel sleeve is ground using a conventional grinding method on an ultra-high precision CNC cylindrical grinding machine. After grinding, the dimensional accuracy of the outer diameter of the thin-walled steel sleeve is ±0.005mm, which is much lower than the processing accuracy of Embodiment 3 of the present invention.

[0067] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A grinding method for a stress-relieving device before grinding ultra-high precision thin-walled steel sleeve rolls, characterized in that, The stress-relieving device includes a pair of fixedly installed support positioning blocks for supporting the outer circumference of the thin-walled steel sleeves at both ends of the roll, and a rotary drive device for driving the roll to rotate on the pair of support positioning blocks; the support positioning blocks are V-shaped blocks, and the V-shaped support surfaces of the V-blocks are filled with lubricating grease; the grinding method includes the following steps: (1) Steel sleeve pre-processing: The thin-walled steel sleeve is pre-processed separately; the inner hole and two end faces of the thin-walled steel sleeve are machined to the required size, and the outer circle of the thin-walled steel sleeve is left with grinding allowance; (2) Steel sleeve assembly: The pre-processed thin-walled steel sleeve is installed on the outer circle of the end of the roll by heat fitting. After the steel sleeve is assembled, an interference fit is formed between the inner hole of the thin-walled steel sleeve and the outer circle of the end of the roll. (3) Steel sleeve stress relief treatment: The roll with the thin-walled steel sleeve installed is hoisted onto a pair of support positioning blocks on the stress relief device. One end of the roll is connected to the rotary drive device through the roll connecting fixture. The rotary drive device is turned on to drive the roll to rotate continuously for a period of time. Under the action of the roll's own weight, the thin-walled steel sleeve at the end of the roll is pressed on the support positioning block and rotates continuously under pressure, so that the internal stress of the thin-walled steel sleeve is released. (4) Steel sleeve grinding: A high-precision cylindrical grinding machine is used to grind the outer circle of the thin-walled steel sleeve after the stress at the end of the roll is released, so that the dimensional accuracy of the outer circle of the thin-walled steel sleeve after grinding reaches ±0.001mm; The rotating drive device uses a variable frequency motor controlled by a controller. The stress relief treatment of the steel sleeve in step (3) is carried out in two stages. The first stage is constant speed rotation stress relief. Under the control of the controller, the variable frequency motor drives the roller to rotate at a constant speed for several hours. After reaching the set time, it enters the second stage of gradual deceleration rotation stress relief. Under the control of the controller, the variable frequency motor drives the roller to rotate at a gradual deceleration for several hours until the minimum speed is reached and then the rotation stops.

2. The grinding method of the stress-relieving device before grinding of ultra-high precision thin-walled steel sleeve rolls according to claim 1, characterized in that, A friction-reducing plate is provided on the V-shaped support surface of the V-block, and the lubricating grease is injected onto the support surface of the friction-reducing plate.

3. The grinding method of the stress-relieving device before grinding of ultra-high precision thin-walled steel sleeve rolls according to claim 1, characterized in that, The rotary drive device includes a fixedly mounted drive motor and a roll connecting fixture disposed between the output shaft of the drive motor and one end of the roll; wherein the drive motor is a geared motor or a variable frequency motor.

4. The grinding method of the stress-relieving device before grinding of ultra-high precision thin-walled steel sleeve rolls according to claim 3, characterized in that, It also includes a base and a guide rail groove disposed on the base, a T-slot disposed on the base and parallel to the guide rail groove, the pair of support positioning blocks are movably disposed on the guide rail groove and fixedly connected to the base by T-bolts and nuts disposed on the T-slot; a lifting platform is disposed on the base, and the drive motor is fixed on the lifting platform.

5. The grinding method of the stress-relieving device before grinding of ultra-high precision thin-walled steel sleeves for rolling mills according to claim 3, characterized in that, The roll connecting fixture includes an active dial fixed on the output shaft of the drive motor, a driven dial fixed at the end of the roll, and a pin connecting the active dial and the driven dial.

6. The grinding method of the stress-relieving device before grinding of ultra-high precision thin-walled steel sleeve rolls according to claim 5, characterized in that, One end of the pin is fixedly connected to one of the active and passive dials, and the other end of the pin is connected to the shaft of the other dial.

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