A bonding process method for a permanent magnetic hemispherical end polishing head based on on-site monitoring of radial runout

Abstract

The present invention provides a method for bonding a permanent magnetic hemispherical end polishing head based on in-situ monitoring of radial runout, which relates to the field of ultra-precision machining technology and aims to solve the problem that the radial runout of the permanent magnetic hemispherical end polishing head obtained by the existing method is too high and cannot be used for high-precision polishing. The method comprises: monitoring the radial runout during the rotation of a support rod by a laser displacement sensor, and controlling the radial runout of the support rod to be lower than a preset runout value; mounting the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head on the mounting shaft of the support rod, monitoring the radial runout at multiple positions on the cylindrical surface of the hemispherical end permanent magnet, and controlling the radial runout at each position to be lower than a preset runout value; bonding and fixing the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod using a resin adhesive, monitoring the radial runout at multiple positions on the cylindrical surface of the hemispherical end permanent magnet, and controlling the radial runout at each position to be lower than a preset runout value, and storing the bonded permanent magnetic hemispherical end polishing head.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-precision machining, and in particular to a bonding process method for a permanent magnetic hemispherical end polishing head based on on-site monitoring of radial runout. Background Art

[0002] With the advancement of science and technology and manufacturing, various new-generation high-performance instruments and equipment are becoming increasingly lightweight, compact, and highly integrated, while also improving their performance, including service life, reliability, and precision. Small parts with complex three-dimensional structures are often key components for improving the integration and performance of these instruments and equipment, such as the hemispherical resonator in a hemispherical resonator gyroscope. The surface structure dimensions of these small parts with complex three-dimensional structures are typically millimeter-scale, making traditional polishing methods inadequate. Therefore, a magnetorheological polishing method using a small permanent magnetic hemispherical polishing head has been developed. The small permanent magnetic hemispherical polishing head consists of a hemispherical permanent magnet with a maximum diameter of only 4 mm and a length of only 5 mm, and a support rod with a diameter of 3 mm and a length of 50 mm. During the polishing process, a polishing gap of approximately 0.1mm is maintained between the permanent magnetic hemispherical polishing head and the workpiece surface. As the permanent magnetic hemispherical polishing head rotates at high speed, the magnetorheological polishing fluid continuously flows through the polishing gap. During this flow, the abrasive particles in the magnetorheological polishing fluid continuously shear the workpiece surface, achieving material removal. Therefore, a strong and reliable combination of the permanent magnetic hemispherical polishing head is the prerequisite for ensuring stable and continuous polishing.

[0003] The material of the hemispherical permanent magnet is sintered neodymium iron boron. When the temperature exceeds 80°C, its magnetic field will undergo irreversible decay or even disappear. Therefore, it is difficult to weld the hemispherical permanent magnet and the support rod together by welding. Therefore, the hemispherical permanent magnet and the support rod are in a transitional fit, and the radial runout of the hemispherical permanent magnet varies greatly, which is not conducive to subsequent direct use or shaping using a grinding wheel. Moreover, in order to improve the polishing efficiency of fused quartz materials, alkaline substances are usually added to the magnetorheological polishing fluid to make it have a strong alkalinity. If the hemispherical permanent magnet is bonded to the support rod, it is necessary to consider the problem of the bonding part being corroded and loosened by the strong alkaline magnetorheological polishing fluid during the polishing process, and the radial runout being too large after bonding. Moreover, the existing permanent magnetic hemispherical end polishing heads are often assembled and bonded manually, resulting in excessive radial runout of the permanent magnetic hemispherical end polishing heads, which makes it impossible to maintain a stable polishing material removal rate during the processing, resulting in uneven material removal, affecting the surface quality and surface accuracy of the workpiece after polishing. This makes it impossible to use the bonded polishing heads directly for polishing processing, and they need to be reshaped or directly scrapped, increasing production costs. When the grinding wheel is used to grind and reshape the polishing heads in the future, the excessive runout means more grinding removal, resulting in serious wear of the grinding wheel, low polishing head reshaping efficiency, and insufficient output. Summary of the Invention

[0004] The technical problems to be solved by the present invention are:

[0005] The existing method for assembling and bonding a permanent magnetic hemispherical end polishing head solves the problem that the radial runout of the permanent magnetic hemispherical end polishing head obtained is too high and cannot be applied to high-precision polishing processing.

[0006] The present invention is to solve the above technical problems using the following technical solutions:

[0007] The present invention provides a method for bonding a permanent magnetic hemispherical polishing head based on in-situ monitoring of radial runout. The method employs an auxiliary bonding device, which is provided with a workpiece spindle for clamping the polishing head. The polishing head is continuously rotated by a driving motor. The method also includes a laser displacement sensor for monitoring the radial runout of the polishing head. The laser displacement sensor irradiation position is adjusted by a laser sensor fine-tuning platform.

[0008] The polishing head bonding process comprises the following steps:

[0009] S1. Clamp the support rod of the permanent magnetic hemispherical polishing head onto the workpiece spindle of the auxiliary bonding equipment, and adjust the height of the laser displacement sensor so that the laser emission window and the axis of the support rod mounting shaft section are at the same height;

[0010] S2. Turn on the auxiliary bonding device. While the support rod is rotating continuously, monitor the radial runout of the support rod during rotation using a laser displacement sensor. When the radial runout of the support rod is lower than a preset runout value, stop the rotation.

[0011] S3. Mount the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head on the mounting shaft of the support rod, adjust the position of the laser displacement sensor so that the laser beam is irradiated on the cylindrical surface of the hemispherical end permanent magnet, and monitor the radial runout at multiple positions on the cylindrical surface of the hemispherical end permanent magnet through the laser displacement sensor while the permanent magnetic hemispherical end polishing head is in a continuous rotation state. When the radial runout at each position on the cylindrical surface of the hemispherical end permanent magnet is controlled to be lower than a preset runout value, the rotation is stopped.

[0012] S4. Use resin adhesive to bond the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod. When the permanent magnetic hemispherical end polishing head is in continuous rotation, the radial runout of multiple positions on the cylindrical surface of the hemispherical end permanent magnet is monitored by a laser displacement sensor. The radial runout of each position on the cylindrical surface of the hemispherical end permanent magnet is controlled to be lower than the preset value of the runout, and the rotation is stopped. The bonded permanent magnetic hemispherical end polishing head is removed from the workpiece spindle and stored.

[0013] Furthermore, the rotation speed of the support rod in S2 is 30 rpm.

[0014] Furthermore, the preset value of the runout described in S2 is 1.5μm. If the radial runout of the inner support rod is higher than 1.5μm, the support rod is re-clamped at a different angle, and the radial runout of the support rod during rotation is monitored by a laser displacement sensor until the radial runout is lower than 1.5μm.

[0015] Furthermore, the radial runout during the rotation of the support rod as described in S2 is monitored by a laser displacement sensor. Specifically, the relative displacement data of the support rod to be measured during the rotation is collected by the laser displacement sensor. In the full-circle displacement data, the difference between the maximum and minimum values ​​is the radial runout.

[0016] Furthermore, the permanent magnetic hemispherical end polishing head in S3 continuously rotates at a speed of 30 rpm.

[0017] Furthermore, as described in S3, the radial runout at multiple positions on the cylindrical surface of the permanent magnet at the hemispherical end is monitored by a laser displacement sensor, and the number of monitored positions is not less than three.

[0018] Furthermore, the preset value of the runout described in S3 is 30μm. If the radial runout at any position exceeds 30μm, the hemispherical end permanent magnet is reinstalled at a different angle, and the radial runout at multiple positions on the cylindrical surface of the hemispherical end permanent magnet is monitored by a laser displacement sensor until the radial runout at each position is less than 30μm.

[0019] Furthermore, in S4, a resin adhesive is used to bond and fix the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod, which includes the following steps:

[0020] S41, mixing liquid epoxy resin glue and curing agent in a ratio of 1:1 as an adhesive;

[0021] S42, take a small amount of adhesive to bond the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod, and leave it for 24 hours to allow the epoxy resin adhesive to completely cure;

[0022] S43. Prepare epoxy resin glue again and drip it on the junction where the permanent magnet at the hemispherical end and the support rod are not bonded. Turn on the polishing equipment to make the support rod and the permanent magnet at the hemispherical end rotate continuously. During the rotation, use a scraper to evenly spread the added epoxy resin glue so that the gap between the permanent magnet at the hemispherical end and the support rod is covered with epoxy resin glue. Reinforce the bonding area and let it stand for 24 hours to allow the epoxy resin glue to completely cure.

[0023] Furthermore, the permanent magnetic hemispherical end polishing head in S4 continuously rotates at a speed of 15 rpm.

[0024] Furthermore, the preset value of the runout described in S4 is 30μm. If the radial runout at any position exceeds 30μm, the permanent magnet at the hemispherical end is debonded and re-bonded at a different angle, and then the radial runout at multiple positions on the cylindrical surface of the permanent magnet at the hemispherical end is monitored by a laser displacement sensor until the radial runout at each position is less than 30μm.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention discloses a method for bonding a permanent magnet hemispherical end polishing head based on on-site monitoring of radial runout. The method suppresses radial runout during the bonding process of the hemispherical end permanent magnet through real-time on-site monitoring by a laser displacement sensor. On the one hand, the method is beneficial to reducing the eccentric mass of the permanent magnet hemispherical end polishing head, avoiding vibration during high-speed rotation, maintaining stable material removal, and having no significant impact on the surface accuracy of the polished workpiece. On the other hand, the method is beneficial to reducing the runout removal amount and shortening the shaping time in the subsequent grinding and shaping.

[0027] The present invention adopts alkali-resistant epoxy resin glue as an adhesive, so that the hemispherical end permanent magnet and the support rod can maintain tight adhesion in a strongly alkaline magnetorheological polishing fluid environment, and the bonding part will not be corroded. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Flowchart of a method for bonding a permanent magnetic hemispherical end polishing head based on in-situ monitoring of radial runout in an embodiment of the present invention;

[0029] Figure 2 Schematic diagram of a permanent magnetic hemispherical end polishing head auxiliary bonding device in an embodiment of the present invention;

[0030] Figure 3 Schematic diagram of the structure and assembly of the permanent magnetic hemispherical end polishing head in an embodiment of the present invention;

[0031] Figure 4 Schematic diagram of bonding of a permanent magnetic hemispherical end polishing head in an embodiment of the present invention, wherein 1 is a bonding area.

[0032] Description of reference numerals:

[0033] 1-workpiece spindle protection cover, 2-workpiece spindle, 3-permanent magnetic hemispherical end polishing head, 4-laser displacement sensor, 5-laser displacement sensor fine-tuning platform, 6-horizontal workbench. DETAILED DESCRIPTION

[0034] In the description of the present invention, it should be noted that the terms "first," "second," and "third" mentioned in the embodiments of the present invention are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Therefore, a feature specified as "first," "second," or "third" may explicitly or implicitly include one or more of such features.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] Specific implementation plan 1: Combined Figures 1 to 2 As shown, the present invention provides a permanent magnet hemispherical end polishing head bonding process method based on in-situ monitoring of radial runout, as shown in 2, using an auxiliary bonding device, the auxiliary bonding device is provided with a horizontal workbench 6, a workpiece spindle 2 for clamping the polishing head is provided above the horizontal workbench 6, the polishing head is continuously rotated by a driving motor, and is connected to the horizontal workbench 6 through a workpiece spindle protective cover 1, and is provided with a laser displacement sensor 4 for monitoring the radial runout of the polishing head, and the irradiation position of the laser displacement sensor 4 is adjusted by a laser sensor fine-tuning platform 5;

[0037] The polishing head bonding process comprises the following steps:

[0038] S1. Clamp the support rod of the permanent magnetic hemispherical polishing head onto the workpiece spindle of the auxiliary bonding equipment, and adjust the height of the laser displacement sensor so that the laser emission window and the axis of the support rod mounting shaft section are at the same height;

[0039] S2. Turn on the auxiliary bonding device. While the support rod is rotating continuously, monitor the radial runout of the support rod during rotation using a laser displacement sensor. When the radial runout of the support rod is lower than a preset runout value, stop the rotation.

[0040] S3. Mount the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head on the mounting shaft of the support rod, adjust the position of the laser displacement sensor so that the laser beam is irradiated on the cylindrical surface of the hemispherical end permanent magnet, and monitor the radial runout at multiple positions on the cylindrical surface of the hemispherical end permanent magnet through the laser displacement sensor while the permanent magnetic hemispherical end polishing head is in a continuous rotation state. When the radial runout at each position on the cylindrical surface of the hemispherical end permanent magnet is controlled to be lower than a preset runout value, the rotation is stopped.

[0041] S4. Use resin adhesive to bond the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod. When the permanent magnetic hemispherical end polishing head is in continuous rotation, the radial runout of multiple positions on the cylindrical surface of the hemispherical end permanent magnet is monitored by a laser displacement sensor. The radial runout of each position on the cylindrical surface of the hemispherical end permanent magnet is controlled to be lower than the preset value of the runout, and the rotation is stopped. The bonded permanent magnetic hemispherical end polishing head is removed from the workpiece spindle and stored.

[0042] like Figure 3 As shown, the hemispherical permanent magnet 3-1 in this embodiment is sintered from neodymium iron boron material. The support rod 3-3 is a pin-type plug gauge with a mounting shaft section 3-2 made of bearing steel. The mounting shaft section 3-2 on the support rod is used to mate with the hemispherical permanent magnet 3-1. Due to the magnetic properties of the hemispherical permanent magnet 3-1, it can be adsorbed to the hemispherical permanent magnet mounting shaft section 3-2 of the support rod. In this embodiment, the sampling frequency of the laser displacement sensor is set to 392kHz, and the number of stored data points is set to 1.2 million.

[0043] In this embodiment, first, by real-time monitoring of the radial runout of the support rod due to factors such as clamping errors and controlling it within a certain range, the radial runout of the hemispherical end permanent magnet assembly datum is suppressed; second, the assembly position of the hemispherical end permanent magnet is monitored and adjusted in real time to keep its radial runout within an acceptable range; finally, the radial runout of the bonded permanent magnet hemispherical end polishing head is monitored, and polishing heads with radial runout exceeding the range are accurately screened and eliminated, so that the final permanent magnet hemispherical end polishing head has a lower radial runout and higher assembly accuracy. This ensures that the radial runout of the obtained permanent magnet hemispherical end polishing head will not significantly affect the stability of the material removal rate when used in actual polishing processing.

[0044] Specific implementation scheme 2: In S2, the support rod continuously rotates at a speed of 30 rpm.

[0045] Specific implementation plan three: The preset value of the runout described in S2 is 1.5μm. If the radial runout of the inner support rod is higher than 1.5μm, the support rod is re-clamped at a different angle, and the radial runout during the rotation of the support rod is monitored by a laser displacement sensor until the radial runout is lower than 1.5μm.

[0046] Specific implementation plan four: As described in S2, the radial runout during the rotation of the support rod is monitored by a laser displacement sensor. Specifically, the relative displacement data of the support rod to be measured during the rotation process is collected by the laser displacement sensor. In the full-circle displacement data, the difference between the maximum and minimum values ​​is the radial runout.

[0047] Specific implementation plan 5: The permanent magnetic hemispherical end polishing head in S3 continuously rotates at a speed of 30 rpm.

[0048] Specific implementation plan six: As described in S3, the radial runout at multiple positions on the cylindrical surface of the permanent magnet at the hemispherical end is monitored by a laser displacement sensor, and the number of monitoring positions is not less than three.

[0049] Specific implementation plan seven: The preset value of the runout described in S3 is 30μm. If the radial runout at any position exceeds 30μm, the hemispherical end permanent magnet is reinstalled at a different angle, and the radial runout at multiple positions on the cylindrical surface of the hemispherical end permanent magnet is monitored by a laser displacement sensor until the radial runout at each position is less than 30μm.

[0050] Specific implementation scheme eight: In S4, a resin adhesive is used to bond and fix the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod, including the following steps:

[0051] S41, mixing liquid epoxy resin glue and curing agent in a ratio of 1:1 as an adhesive;

[0052] S42, take a small amount of adhesive to bond the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod, and leave it for 24 hours to allow the epoxy resin adhesive to completely cure;

[0053] S43. Prepare epoxy resin glue again and drip it on the junction where the permanent magnet at the hemispherical end and the support rod are not bonded. Turn on the polishing equipment to make the support rod and the permanent magnet at the hemispherical end rotate continuously. During the rotation, use a scraper to evenly spread the added epoxy resin glue so that the gap between the permanent magnet at the hemispherical end and the support rod is covered with epoxy resin glue. Reinforce the bonding area and let it stand for 24 hours to allow the epoxy resin glue to completely cure.

[0054] The permanent magnetic hemispherical end polishing head obtained by bonding in this embodiment can be stably used in an environment of a strong alkaline magnetorheological polishing liquid with a pH value of 14, and the bonding part will not be corroded. Figure 4 shown.

[0055] Specific implementation scheme nine: The permanent magnetic hemispherical end polishing head in S4 continuously rotates at a speed of 15 rpm.

[0056] Specific implementation plan ten: The preset value of the runout described in S4 is 30μm. If the radial runout at any position exceeds 30μm, the permanent magnet at the hemispherical end is debonded and re-bonded at a different angle, and then the radial runout at multiple positions on the cylindrical surface of the permanent magnet at the hemispherical end is monitored by a laser displacement sensor until the radial runout at each position is less than 30μm.

[0057] Although the present invention is disclosed as above, the scope of protection disclosed by the present invention is not limited thereto. Those skilled in the art of the present invention may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A permanent magnetic hemispherical end polishing head bonding process method based on in-situ monitoring of radial runout, characterized in that: An auxiliary bonding device is used, which is equipped with a workpiece spindle for clamping the polishing head, which is driven by a motor to continuously rotate the polishing head, and is equipped with a laser displacement sensor for monitoring the radial runout of the polishing head. The laser displacement sensor irradiation position is adjusted by a laser sensor fine-tuning platform; The polishing head bonding process comprises the following steps: S1. Clamp the support rod of the permanent magnetic hemispherical polishing head onto the workpiece spindle of the auxiliary bonding equipment, and adjust the height of the laser displacement sensor so that the laser emission window and the axis of the support rod mounting shaft section are at the same height; S2. Turn on the auxiliary bonding device. While the support rod is rotating continuously, monitor the radial runout of the support rod during rotation using a laser displacement sensor. When the radial runout of the support rod is lower than a preset runout value, stop the rotation. S3. Mount the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head on the mounting shaft of the support rod, adjust the position of the laser displacement sensor so that the laser beam is irradiated on the cylindrical surface of the hemispherical end permanent magnet, and monitor the radial runout at multiple positions on the cylindrical surface of the hemispherical end permanent magnet through the laser displacement sensor while the permanent magnetic hemispherical end polishing head is in a continuous rotation state. When the radial runout at each position on the cylindrical surface of the hemispherical end permanent magnet is controlled to be lower than a preset runout value, the rotation is stopped. S4. Use resin adhesive to bond the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod. When the permanent magnetic hemispherical end polishing head is in continuous rotation, the radial runout of multiple positions on the cylindrical surface of the hemispherical end permanent magnet is monitored by a laser displacement sensor. The radial runout of each position on the cylindrical surface of the hemispherical end permanent magnet is controlled to be lower than the preset value of the runout, and the rotation is stopped. The bonded permanent magnetic hemispherical end polishing head is removed from the workpiece spindle and stored.

2. The permanent magnetic hemispherical end polishing head bonding process method based on in-situ monitoring of radial runout according to claim 1 is characterized in that: The support rod in S2 continuously rotates at a speed of 30 rpm.

3. The bonding process of a permanent magnetic hemispherical end polishing head based on in-situ monitoring of radial runout according to claim 2 is characterized in that: The preset value of the runout described in S2 is 1.5μm. If the radial runout of the inner support rod is higher than 1.5μm, the support rod is re-clamped at a different angle, and the radial runout during the rotation of the support rod is monitored by a laser displacement sensor until the radial runout is lower than 1.5μm.

4. The bonding process of a permanent magnetic hemispherical end polishing head based on on-site monitoring of radial runout according to claim 3 is characterized in that: The laser displacement sensor is used to monitor the radial runout of the support rod during its rotation as described in S2. Specifically, the laser displacement sensor is used to collect relative displacement data of the support rod to be measured during its rotation. In the full-circle displacement data, the difference between the maximum and minimum values ​​is the radial runout.

5. The bonding process of a permanent magnetic hemispherical end polishing head based on on-site monitoring of radial runout according to claim 4 is characterized in that: The permanent magnetic hemispherical polishing head in S3 continuously rotates at a speed of 30 rpm.

6. The bonding process of a permanent magnetic hemispherical end polishing head based on in-situ monitoring of radial runout according to claim 5 is characterized in that: As described in S3, the radial runout at multiple positions on the cylindrical surface of the permanent magnet at the hemispherical end is monitored by a laser displacement sensor, and the number of monitored positions is not less than three.

7. The bonding process of a permanent magnetic hemispherical end polishing head based on on-site monitoring of radial runout according to claim 6 is characterized in that: The preset value of the runout described in S3 is 30μm. If the radial runout at any position exceeds 30μm, the hemispherical end permanent magnet is reinstalled at a different angle, and the radial runout at multiple positions on the cylindrical surface of the hemispherical end permanent magnet is monitored by a laser displacement sensor until the radial runout at each position is less than 30μm.

8. The bonding process of a permanent magnetic hemispherical end polishing head based on on-site monitoring of radial runout according to claim 7 is characterized in that: In S4, a resin adhesive is used to bond and fix the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod, including the following steps: S41, mixing liquid epoxy resin glue and curing agent in a ratio of 1:1 as an adhesive; S42, take a small amount of adhesive to bond the hemispherical end permanent magnet of the permanent magnetic hemispherical end polishing head to the support rod, and leave it for 24 hours to allow the epoxy resin adhesive to completely cure; S43. Prepare epoxy resin glue again and drip it on the junction where the permanent magnet at the hemispherical end and the support rod are not bonded. Turn on the polishing equipment to make the support rod and the permanent magnet at the hemispherical end rotate continuously. During the rotation, use a scraper to evenly spread the added epoxy resin glue so that the gap between the permanent magnet at the hemispherical end and the support rod is covered with epoxy resin glue. Reinforce the bonding area and let it stand for 24 hours to allow the epoxy resin glue to completely cure.

9. The bonding process of a permanent magnetic hemispherical end polishing head based on on-site monitoring of radial runout according to claim 8 is characterized in that: The permanent magnetic hemispherical polishing head in S4 continuously rotates at a speed of 15 rpm.

10. The bonding process of a permanent magnetic hemispherical end polishing head based on on-site monitoring of radial runout according to claim 9, characterized in that: The preset value of the runout described in S4 is 30μm. If the radial runout at any position exceeds 30μm, the permanent magnet at the hemispherical end is debonded and re-bonded at a different angle. The laser displacement sensor is then used to monitor the radial runout at multiple positions on the cylindrical surface of the permanent magnet at the hemispherical end until the radial runout at each position is less than 30μm.

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