Guide processing method

Abstract

This invention belongs to the field of guide machining technology, and particularly relates to a guide machining method. A guide machining method includes the following steps: S1. Clamping and positioning the sleeve with a fixture; S2. Heating the sleeve; S3. Inserting the guide into the sleeve; S4. Machining the inner edge step of one end of the guide; S5. Heating the sleeve; S6. Removing the guide, rotating it 180°, and then reinserting it into the sleeve; S7. Machining the inner edge step of the other end of the guide; S8. Heating the sleeve and removing the guide, completing the guide machining. This invention has the advantage of ensuring the clamping accuracy of the guide workpiece in both the initial and final clamping stages, thereby ensuring good concentricity of the inner circular steps at both ends of the guide workpiece.

Description

Technical Field

[0001] This invention belongs to the field of guide processing technology, and particularly relates to a guide processing method. Background Technology

[0002] A guide is a device installed before and after the roll pass during the rolling process of structural steel to help the rolled workpiece enter and exit the roll pass accurately and stably in a predetermined direction and state.

[0003] The key to guide machining lies in the machining of the inner circular steps at both ends. These inner circular steps are used to install bearings and generally require a high degree of precision, free of any scratches. When machining the inner circular steps at both ends of the guide, the guide needs to be clamped and positioned to improve the concentricity of the inner circular steps. Currently, guide machining typically utilizes long jaws to clamp the entire outer circle of the guide for positioning, such as a three-jaw chuck.

[0004] For example, Chinese patent application number CN201810458225.X discloses a clamping device for guide processing. A first clamping groove and a first fixing block can fix a first substrate and a clamping block in approximately the same position. Further adjustments can be made by adjusting a push rod, and pushing the clamping block can clamp the guide. Since both ends of the guide have inner circular steps, after processing one end of the guide's inner circular step, the guide needs to be flipped over to process the inner circular step at the other end. While the above solution can clamp the guide, adjusting the clamping only by adjusting the push rod will result in a large positional deviation between the two clamping operations, leading to poor concentricity of the inner circular steps at both ends of the processed guide. Summary of the Invention

[0005] The purpose of this invention is to provide a guide machining method that can ensure the accuracy of the guide workpiece during both clamping operations, thereby ensuring good concentricity of the inner circular steps at both ends of the guide.

[0006] To achieve the above objectives, the present invention discloses a guide processing method, comprising the following steps:

[0007] S1. The clamp is clamped and fixed by the fixture, and the clamp is aligned by dial indicator to make the clamp coaxial with the fixture. The clamp is provided with an inner hole for setting the guide workpiece. The bottom of the inner hole forms a stepped surface to support the guide workpiece. The clamp is provided with a number of clamping parts on the end face of the opening end of the inner hole to press the end face of the guide workpiece.

[0008] S2. Heating the jacket causes the inner hole of the jacket to expand;

[0009] S3. Insert the guide workpiece into the inner hole of the clamp, so that the outer circle of the guide workpiece is in clearance fit with the inner hole of the clamp, one end of the guide workpiece abuts against the stepped surface of the inner hole of the clamp, and the other end of the guide workpiece is pressed by the clamping part of the clamp, and the end face of the guide workpiece corresponding to the end of the clamping part is aligned by dialing to make the guide workpiece and the clamp coaxial. Then, the clamp is naturally cooled or forced to cool, so that the clamp shrinks and clamps the guide workpiece.

[0010] S4. After the jacket cools down, machine the inner circle step of the guide workpiece corresponding to one end of the clamping part;

[0011] S5. Heat the jacket to expand the inner hole of the jacket;

[0012] S6. Loosen the clamping parts, take out the guide workpiece and rotate it 180°. Put the rotated guide workpiece into the clamp, and clamp the other end of the guide workpiece with the clamping parts of the clamp. Then, use a dial indicator to align the end face of the guide workpiece corresponding to the clamping part so that the guide workpiece is coaxial with the clamp. After that, allow the clamp to cool naturally or by forced cooling so that the clamp shrinks and clamps the guide workpiece.

[0013] S7. Machining the inner circular step at the other end of the guide workpiece;

[0014] S8. Heat the jacket to expand the inner hole of the jacket, and remove the guide to complete the processing.

[0015] The device for machining the inner circle and inner circle steps of the guide workpiece can be any existing internal grinding lathe; the fixture is a high-precision fixture, such as a three-jaw chuck; the heating method can be hot water at a temperature above 80 degrees Celsius or high-temperature steam heating; the expansion of the inner hole of the jacket refers to the increase in the inner hole diameter of the jacket; the dial indicator alignment can be performed by dial indicator or by laser rangefinder.

[0016] The clamp is held in place by a fixture, ensuring it remains in a clamped state. The clamp and guide workpiece are fitted with a clearance fit, which is used to position the guide workpiece. This ensures that the guide's position remains unchanged between two clamping cycles, thus guaranteeing good concentricity of the inner circular steps at both ends of the guide workpiece. First, the clamp is aligned using a dial indicator to ensure its coaxiality. Then, the guide is aligned again using a dial indicator to ensure its coaxiality, further ensuring the concentricity of the inner circular steps at both ends of the guide workpiece.

[0017] Preferably, in S2, S5 and S8, the heating jacket is heated by continuously pouring hot water at a temperature of 80-100 degrees Celsius onto the jacket for 2 to 3 minutes.

[0018] Hot water irrigation is low-cost and the equipment for hot water irrigation is simple. The jacket material can be heat-treated 45 steel or 42CrMo4 steel.

[0019] Preferably, in step S1, a dial indicator is used to align the jacket, and the runout value of the end face or inner hole of the jacket is measured by the dial indicator. The size of the runout value of the end face or inner hole of the jacket is used to determine whether the jacket and the fixture are coaxial.

[0020] Because lasers have high requirements for the surface of the product, and laser alignment usually uses direct laser beams, when aligning the inner hole of the jacket, the laser beams at an angle onto the inner hole wall. Dial indicators do not have these problems, so using a dial indicator for alignment is a better choice.

[0021] Preferably, if the runout value of the end face or inner hole of the jacket exceeds the range, the jacket is corrected by repeatedly re-clamping it with a fixture or by tapping it with a copper rod. The runout value of the end face or inner hole of the jacket is then re-measured with a dial indicator. If the runout value still exceeds the range, the fixture or jacket needs to be repaired or replaced.

[0022] The clamp is typically a three-jaw chuck. The self-centering accuracy of a three-jaw chuck is 0.05–0.15 mm, which is quite high, so adjustments can be made by retightening the clamp. Tapping with a copper rod is used because the copper rod is relatively soft and will not damage the clamp.

[0023] Preferably, in S3 and S6, a dial indicator is used to align the end face of the guide workpiece corresponding to the end of the clamping member. The runout value of the end face of the guide workpiece corresponding to the end of the clamping member is measured by the dial indicator. The coaxiality of the guide workpiece and the clamping sleeve is determined based on the runout value of the end face of the guide workpiece corresponding to the end of the clamping member.

[0024] Preferably, if the runout value of the end face of the guide workpiece corresponding to one end of the clamping member exceeds the range value, several clamping members are adjusted, and the runout value of the end face of the guide workpiece corresponding to one end of the clamping member is remeasured using a dial indicator.

[0025] Several clamping components press against multiple points on the end face of the guide workpiece. When the end face runout value at a certain position changes significantly, the clamping force of the clamping components at that position can be adjusted to complete the dial indicator alignment of the guide workpiece.

[0026] Preferably, when machining the inner circular step of the guide workpiece in S5 and S8, multiple batches of machining are used. Before each machining, the depth of the inner circular step is measured with a depth micrometer to ensure that the inner circular step has a machining allowance of 5 to 6 microns.

[0027] Processing in multiple batches, with measurements taken before each batch, can prevent the step depth from being reached in one step, which would result in insufficient machining allowance and scrap the guide workpiece.

[0028] Preferably, the number of clamping elements is three, and they are arranged in a ring with uniform spacing around the axis of the clamping sleeve on the end face of the opening corresponding to the inner hole of the clamping sleeve.

[0029] Evenly spaced intervals are more conducive to pressing the guides firmly and are easier to adjust when using a dial indicator to align the guides.

[0030] Preferably, the clamping member includes a pressure plate for contacting the end face of the guide workpiece, the pressure plate having a through hole through which a locking member passes, the locking member being threadedly engaged with the opening end face of the sleeve corresponding to the inner hole.

[0031] The guide is pressed by a pressure plate, and the locking part is threaded with the jacket. When aligning the guide with a dial indicator, the adjustment can be made by tightening or loosening the locking part.

[0032] Preferably, the gap between the inner hole of the jacket and the outer circle of the guide workpiece is less than or equal to 0.012 mm.

[0033] Controlling the gap to within 0.012mm ensures that the concentricity error between the guide clamping and the sleeve is within 0.012mm, thereby guaranteeing the clamping accuracy of the guide workpiece in both the preceding and subsequent clamping operations and ensuring good concentricity of the inner circular steps at both ends of the guide.

[0034] The present invention has the following advantages: the clamp is locked in the same position on the fixture throughout the entire processing, which ensures the clamping accuracy of the guide workpiece in the two clamping operations, thereby ensuring good concentricity of the inner circular steps at both ends of the guide. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the guide workpiece processing device of the present invention.

[0036] Figure 2 for Figure 1 A magnified view of point A.

[0037] Figure 3 This is a cross-sectional view of the jacket and the guide workpiece together.

[0038] Figure 4 This is a schematic diagram of the jacket structure.

[0039] Reference numerals in the attached figures: 1. Machining device; 2. Jacket; 21. Stepped surface; 22. Inner hole; 3. Pressing plate; 4. Locking element; 5. Three-jaw chuck; 100. Guide workpiece; 101. First inner circle step; 102. Second inner circle step; 103. Inner circle. Detailed Implementation

[0040] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0041] The processing device 1 of this invention is any existing internal grinding lathe for machining the inner cylindrical steps of a guide workpiece. The sleeve 2 is a hollow column shape and has an axially penetrating inner hole 22. The wall of the inner hole 22 has a stepped surface 21 on the bottom side of the sleeve 2, and the stepped surface 21 extends circumferentially around the wall of the inner hole 22. The top of the sleeve 2 has three clamping members arranged in a ring at uniform intervals around the axis of the sleeve 2. Each clamping member includes a pressure plate 3, which has a through hole (not shown in the figure). A locking member 4 passes through each through hole. The top of the sleeve 2 (corresponding to the open end face of the inner hole) has a threaded hole (not shown in the figure), and the locking member 4 is threadedly engaged with the threaded hole. The locking member 4 is a bolt.

[0042] In actual operation, the guide workpiece 100 needs to be machined with an axially penetrating inner circle 103. In order for the shaft to pass through, a first inner circle step 101 and a second inner circle step 102 are machined at both ends of the inner circle 103. The first inner circle step 101 and the second inner circle step 102 are used to assemble the bearing.

[0043] The guide workpiece processing method of the present invention includes the following steps:

[0044] S1. Clamp and fix the jacket using a three-jaw chuck. Connect the magnetic base and dial indicator (not shown in the figure). Place the measuring end of the dial indicator against the outer end face of the jacket or the inner wall of the jacket's hole. Observe the rotation of the dial indicator pointer. After the dial indicator pointer rotates more than one revolution, record the reading at this time as the zero point. Manually rotate the three-jaw chuck and observe the change of the dial indicator pointer during the rotation. When the change of the dial indicator pointer is within one millisecond during the continuous rotation of the jacket, the alignment of the outer end face of the jacket or the inner hole of the jacket is completed, and the jacket and the three-jaw chuck are coaxial. If the dial indicator pointer changes by more than one millimeter, the clamp needs to be re-clamped multiple times using a three-jaw chuck. After each clamping, the dial indicator should be used to measure the change. If the measured value is within the acceptable range after clamping, the calibration is complete. Alternatively, the clamp can be tapped with a copper rod. For example, if the runout of a certain part of the outer end face of the clamp is five millimeters, it indicates that the part is convex. Tap this part with the copper rod to make it concave inward. If the runout of a certain part of the outer end face of the clamp is -5 millimeters, it indicates that the part is concave. Tap the opposite side of this part with the copper rod to make the concave part convex outward. If the runout value still exceeds one millimeter after adjustment, the three-jaw chuck or clamp needs to be repaired or replaced.

[0045] S2. Open the hot water pipe to pour 90-degree Celsius hot water onto the jacket and continue pouring for 2 minutes, causing the inner hole of the jacket to expand and the inner hole diameter to increase.

[0046] S3. Insert the guide workpiece into the inner hole of the clamping sleeve, ensuring a clearance fit between the outer diameter of the guide workpiece and the inner hole of the clamping sleeve (0.01mm). One end of the guide workpiece should abut against the stepped surface of the inner hole of the clamping sleeve. Tighten the locking mechanism to press the other end of the guide workpiece against the pressure plate. Position the dial indicator's measuring end onto the end face of the guide workpiece corresponding to the pressure plate and observe the dial indicator pointer. After the dial indicator pointer rotates more than one revolution, record the reading as zero. Manually rotate the three-jaw chuck and observe the change in the dial indicator pointer during rotation. When the pointer change is within one millimeter during continuous rotation, the end face alignment of the guide workpiece is complete, achieving coaxiality between the guide workpiece and the clamping sleeve. If the runout value of the end face of the guide workpiece corresponding to the pressure plate exceeds one millimeter, adjust the three pressure plates and remeasure the runout value of the end face of the guide workpiece corresponding to the pressure plate using a dial indicator. Then, cold water is poured onto the jacket and the guide workpiece to cool the jacket and cause it to contract and clamp the guide workpiece. The cold water is room temperature water, and the pouring time is 15 seconds. After that, the inner circle of the guide workpiece is machined by the processing device.

[0047] S4. After machining the inner circle, the inner circle step at one end of the guide workpiece is machined using a machining device. Multiple batches of machining are used. Before each machining, the depth of the inner circle step is measured with a depth micrometer. A machining allowance of 5 microns is required for the depth of the inner circle step. If the requirement is not met, machining needs to continue.

[0048] S5. After machining the inner circle and the inner circle step at one end, open the hot water pipe to pour 90-degree hot water onto the jacket and continue pouring for 2 minutes to make the inner hole of the jacket expand.

[0049] S6. Loosen the locking parts and remove the pressure plate. Remove the guide workpiece and rotate it 180°. Place the rotated guide workpiece back into the clamp. Retighten the locking parts so that the pressure plate presses against the end face of the guide workpiece. Set the measuring end of the dial indicator to the end face of the guide workpiece corresponding to the pressure plate. Observe the dial indicator pointer. After the dial indicator pointer rotates more than one revolution, record the reading at this time as zero. Manually rotate the three-jaw chuck and observe the change of the dial indicator pointer during the rotation. When the pointer changes within one millimeter during continuous rotation, the end face of the guide workpiece is aligned, and the guide workpiece and the clamp are coaxial. If the runout value of the end face of the guide workpiece corresponding to the pressure plate exceeds the range of one millimeter, adjust the three pressure plates and remeasure the runout value of the end face of the guide workpiece corresponding to the pressure plate using a dial indicator.

[0050] S7. The inner circular step at the other end of the guide workpiece is machined using a machining device. Multiple batches of machining are used. Before each machining, the depth of the inner circular step is measured with a depth micrometer. A machining allowance of 5 microns is required for the depth of the inner circular step. If the requirement is not met, machining needs to continue.

[0051] S8. After machining the inner circular step at the other end, open the hot water pipe to pour 90-degree hot water onto the jacket and continue pouring for 2 minutes to make the inner hole of the jacket expand and remove the guide workpiece, thus completing the machining of the guide workpiece.

Claims

1. A guide processing method, characterized in that, Includes the following steps: S1. The clamp is clamped and fixed by the fixture, and the clamp is aligned by dial indicator to make the clamp coaxial with the fixture. The clamp is provided with an inner hole for setting the guide workpiece. The bottom of the inner hole forms a stepped surface to support the guide workpiece. The clamp is provided with a number of clamping parts on the end face of the opening end of the inner hole to press the end face of the guide workpiece. S2. Heating the jacket causes the inner hole of the jacket to expand; S3. Insert the guide workpiece into the inner hole of the clamp, so that the outer circle of the guide workpiece is in clearance fit with the inner hole of the clamp, one end of the guide workpiece abuts against the stepped surface of the inner hole of the clamp, and the other end of the guide workpiece is pressed by the clamping part of the clamp, and the end face of the guide workpiece corresponding to the end of the clamping part is aligned by dialing to make the guide workpiece and the clamp coaxial. Then, the clamp is naturally cooled or forced to cool, so that the clamp shrinks and clamps the guide workpiece. S4. After the jacket cools down, machine the inner circle step of the guide workpiece corresponding to one end of the clamping part; S5. Heat the jacket to expand the inner hole of the jacket; S6. Loosen the clamping parts, take out the guide workpiece and rotate it 180°. Put the rotated guide workpiece into the clamp, and clamp the other end of the guide workpiece with the clamping parts of the clamp. Then, use a dial indicator to align the end face of the guide workpiece corresponding to the clamping part so that the guide workpiece is coaxial with the clamp. After that, allow the clamp to cool naturally or by forced cooling so that the clamp shrinks and clamps the guide workpiece. S7. Machining the inner circular step at the other end of the guide workpiece; S8. Heat the jacket to expand the inner hole of the jacket, and remove the guide to complete the processing; In S2, S5 and S8, the heating jacket is heated by continuously pouring hot water at a temperature of 80-100 degrees Celsius onto the jacket for 2 to 3 minutes. The clamping components are three in number and are evenly spaced in a ring around the axis of the clamping sleeve on the open end face of the clamping sleeve corresponding to the inner hole. Each clamping component includes a pressure plate for contacting the end face of the guide workpiece. The pressure plate has a through hole, and a locking component passes through the through hole. The locking component is threadedly engaged with the open end face of the clamping sleeve corresponding to the inner hole. The gap between the inner hole of the clamping sleeve and the outer circle of the guide workpiece is less than or equal to 0.012 mm.

2. The guide processing method according to claim 1, characterized in that: In step S1, the clamp is aligned using a dial indicator. The runout of the end face or inner hole of the clamp is measured using the dial indicator. The coaxiality of the clamp and the fixture is determined based on the runout of the end face or inner hole of the clamp.

3. The guide processing method according to claim 2, characterized in that: If the runout value of the end face or inner hole of the jacket exceeds the range, the jacket should be re-clamped multiple times with a fixture or the jacket should be tapped with a copper rod to correct the runout value. The runout value of the end face or inner hole of the jacket should be re-measured with a dial indicator. If the runout value still exceeds the range, the fixture or jacket needs to be repaired or replaced.

4. The guide processing method according to claim 1, characterized in that: In S3 and S6, a dial indicator is used to align the end face of the guide workpiece corresponding to the end of the clamping member. The runout value of the end face of the guide workpiece corresponding to the end of the clamping member is measured by the dial indicator. The coaxiality of the guide workpiece and the clamping sleeve is determined based on the runout value of the end face of the guide workpiece corresponding to the end of the clamping member.

5. The guide processing method according to claim 4, characterized in that: If the runout value of the end face of the guide workpiece corresponding to the end of the clamping member exceeds the range, several clamping members are adjusted, and the runout value of the end face of the guide workpiece corresponding to the end of the clamping member is re-measured using a dial indicator.

6. The guide processing method according to claim 1, characterized in that: In S4 and S7, when machining the inner circular step of the guide workpiece, multiple batches of machining are used. Before each machining, the depth of the inner circular step is measured with a depth micrometer to ensure that the inner circular step has a machining allowance of 5 to 6 microns.

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