A grinding device and method for grinding screw thread grooves using a contoured magnet

Abstract

The present invention relates to a grinding device and method for grinding the thread groove of a screw with a profiling magnet, comprising a horizontal lathe body and a mobile grinding device, wherein the mobile grinding device comprises a profiling magnet, a motor, a deep groove ball bearing, a belt, a sleeve, and a mobile support frame, wherein the mobile support frame is driven by a slide box to move longitudinally on the horizontal lathe body; the mobile support frame is connected to a sleeve through a deep groove ball bearing, the sleeve is fixedly connected to the profiling magnet, the motor is fixed to the mobile support frame, the motor drives the belt, and the belt drives the sleeve to rotate; the horizontal lathe body clamps and fixes the screw to be processed, and drives the screw to be processed to rotate. The advantages are: large grinding area, high efficiency, compact structure, not easy to heat up, cost saving, low stress, the spiral surface and two side surfaces of the screw to be processed can be ground multiple times, the grinding effect is good, and it is especially suitable for precision instruments requiring ultra-precision processing, and occasions with extremely high requirements for transmission smoothness and accuracy.

Description

Technical Field

[0001] The invention belongs to the field of lead screw processing, and in particular relates to a grinding device and a method for grinding a lead screw thread groove using a contoured magnet. Background Art

[0002] The lead screw is an ideal product for converting rotary motion into linear motion, or vice versa. It is a key functional component of CNC machine tools. Moreover, in some precision instruments such as microscopes, the accuracy of the lead screw often determines the accuracy of the entire instrument. Therefore, grinding is often used as the last process to improve the lead screw stroke error and improve the lead screw surface quality.

[0003] At present, lead screws are divided into ordinary lead screws and high-precision lead screws. Most of the high-precision lead screws, such as the lifting lead screws of microscopes, are imported. There is a lack of relevant equipment and technology in China. The surface accuracy we need cannot be achieved using current domestic technology. The processing of ordinary lead screws, such as the moving lead screws on lathes, is often done by manual grinding, or by using a grinding head on a lathe or a lead screw grinder.

[0004] At present, when the number of workpieces is small, many factories use manual grinding. The grinding effect of this grinding method depends on the proficiency of the operator and is inefficient. The control of parameters such as grinding pressure and grinding speed depends on the experience of the workers. There is no fixed standard, let alone a reference standard. After professional testing, it is found that the roughness of the processed surface is uneven and the quality is uneven. Especially when the number of workpieces increases, the labor cost is too high and the processing accuracy cannot be guaranteed.

[0005] In order to solve the disadvantage of low efficiency of manual grinding, a grinding head is often installed on the lathe to process the spiral surface of the screw for large-scale processing of screws. This processing method greatly improves the grinding efficiency, but at the same time, other disadvantages arise, such as: only the spiral surface of the screw spiral tooth profile can be processed, and the two side surfaces of the screw spiral tooth profile cannot be processed; when the device is grinding the screw, it can only grind a small surface at a time, which is easy to heat up, with a large temperature rise, which will produce residual stress and the workpiece is easy to deform; in addition, when the device is working, due to the poor self-sharpening of the grinding head, it is impossible to achieve uniform grinding like magnetic grinding, and the grinding amount is large and difficult to control. Although the grinding efficiency is improved, the grinding accuracy cannot be guaranteed. Summary of the invention

[0006] The purpose of the present invention is to provide a grinding device and method for grinding screw thread grooves with a contoured magnet, which can grind screws of various lengths, diameters and tooth shapes and improve the grinding accuracy of the screw.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] A grinding device for grinding a screw thread groove with a profiling magnet comprises a horizontal lathe body and a mobile grinding device. The mobile grinding device comprises a profiling magnet, a motor, a deep groove ball bearing, a belt, a sleeve, and a mobile support frame. The mobile support frame is driven by a slide box to move longitudinally on the horizontal lathe body; the mobile support frame is connected to the sleeve via a deep groove ball bearing, the sleeve is fixedly connected to the profiling magnet, the motor is fixed to the mobile support frame, the motor drives the belt, and the belt drives the sleeve to rotate; the horizontal lathe body clamps and fixes the screw to be processed, and drives the screw to be processed to rotate.

[0009] The horizontal lathe body comprises a three-jaw chuck and a tailstock chuck, and the three-jaw chuck and the tailstock chuck are used for clamping the lead screw to be processed.

[0010] The contoured magnet comprises a magnetic block and a spiral bracket. The spiral bracket is provided with a positioning groove, and a plurality of magnetic blocks are embedded in the positioning groove. The spiral bracket is made of soft magnetic material.

[0011] The magnetic block is cylindrical.

[0012] The profiling magnet is in a spiral shape matching the screw thread groove, and a gap of 2-3 mm is maintained between the surface of the profiling magnet and the processing surface of the screw to be processed.

[0013] A method for grinding a thread groove of a lead screw by using a contoured magnet comprises the following steps:

[0014] 1) Pass the lead screw to be processed through the sleeve and match it with the contour magnet. The distance between the inner surface of the contour magnet and the surface to be processed of the lead screw to be processed is kept at 2-3mm;

[0015] 2) Use the three-jaw chuck and tailstock chuck to fix the two ends of the lead screw to be processed;

[0016] 3) Place the mobile grinding device at the starting point of the lead screw to be processed;

[0017] 4) Mixing water-based polishing liquid and magnetic polishing particles in a ratio of 1:2, and injecting the mixture of polishing liquid and magnetic particles into the gap between the magnet and the lead screw using a syringe;

[0018] 5) Start the switch, the horizontal lathe body and the motor run at the same time, driving the screw to be processed to rotate, and the motor drives the sleeve to rotate in the opposite direction to the screw to be processed. At the same time, the mobile grinding device moves to the end of the screw to be processed, and the grinding particles on the profiling magnet begin to grind the processing surface of the screw to be processed, and the profiling magnet moves to the end of the screw; rotate in the opposite direction, and when the mobile grinding device returns to the processing starting point, a processing cycle is completed.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention adopts magnetic grinding to finish the surface of the lead screw to be processed. Compared with traditional grinding wheel grinding, the temperature rise is small, the residual stress after processing is small, and it is not easy to deform. At the same time, the magnetic grinding technology has good self-sharpening properties, the grinding is more uniform, and it is not easy to produce scratches on the workpiece surface.

[0021] 2. The processing magnet adopted in the present invention is a profile magnet. Compared with ordinary magnets, the magnet can better fit the processing surface during grinding, increase the single processing area during grinding, and improve the processing efficiency; compared with the currently common use of grinding heads or other grinding tools, the profile magnet can not only efficiently process the spiral surface of the lead screw, but also process the two side surfaces of the spiral surface of the lead screw to be processed. When the precision requirement is very high, such as the lead screw for adjusting the lens in a microscope, the ordinary processing method only processes the spiral surface and does not process the side surface, which often cannot meet the ultra-precision processing requirements of such workpieces.

[0022] 3. This device uses a modified horizontal lathe to clamp the workpiece. On the basis of an ordinary lathe, it is modified to use two three-jaw chucks to clamp the workpiece. When the spindle rotates, the rotation is more stable, the radial vibration amplitude of the screw to be processed is reduced, and the grinding accuracy is higher.

[0023] 4. This device uses a mobile grinding device to grind the lead screw to be processed. The mobile grinding device can move longitudinally (axially) on the slide box. At the same time, a motor is installed on the mobile grinding device. When the spindle box with the moving lead screw to be processed rotates, the motor will drive the contoured magnet to rotate in the opposite direction through the belt, which will improve the grinding efficiency and make the grinding more uniform.

[0024] 5. The present invention uses a water-based grinding liquid and magnetic grinding particles mixed in a ratio of 1:2 and adsorbed on the working surface of the contoured magnet. While improving the grinding efficiency, the grinding liquid will take away excess heat and reduce scratches on the processed surface. At the same time, the water-based grinding liquid plays a role in cooling and chip removal during the processing.

[0025] 6. The present invention as a whole has a large grinding area, high efficiency, compact structure, low heat generation, cost savings, and low stress. The spiral surface and two side surfaces of the lead screw to be processed can be ground multiple times with good grinding effect. The present invention is particularly suitable for precision instruments requiring ultra-precision processing and occasions with extremely high requirements for transmission smoothness and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 It is a structural schematic diagram of a mobile grinding device.

[0028] Figure 3 It is a structural schematic diagram of a contour magnet.

[0029] In the figure: 1-spindle box 2-three-jaw chuck 3-movable support frame 4-belt 5-motor 6-tailstock chuck 7-movable tailstock 8-large handwheel 9-small handwheel 10-slide box 11-ball screw 12-screw to be processed 13-support plate 14-sleeve 15-profile magnet 16-pulley 17-base 18-deep groove ball bearing 151-magnet block 152-spiral bracket 153-positioning groove. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0031] See Figure 1 , Figure 2 A grinding device for grinding screw thread grooves with a profiling magnet 15 is used for grinding and finishing screws of various tooth profiles, diameters and lengths, mainly grinding the bottom and side surfaces of the tooth profiles, and comprises a horizontal lathe body, a mobile grinding device, and the mobile grinding device comprises a profiling magnet 15, a motor 5, a deep groove ball bearing 18, a belt 4, a sleeve 14, and a mobile support frame 3. The mobile support frame 3 is driven by a slide box 10 to move longitudinally on the horizontal lathe body; the mobile support frame 3 is connected to the sleeve 14 through the deep groove ball bearing 18, the sleeve 14 is fixedly connected with the profiling magnet 15, the motor 5 is fixed to the mobile support frame 3, the output shaft of the motor 5 is connected to the pulley 16, the pulley 16 is connected with the belt 4, the motor 5 drives the belt 4, and the belt 4 drives the sleeve 14 to rotate; the horizontal lathe body clamps and fixes the screw 12 to be processed, and drives the screw 12 to be processed to rotate. Among them, the belt 4 can be a V-belt 4. The mobile support frame 3 is composed of a support plate 13 and a base 17 which are fixed perpendicularly to each other. The base 17 is connected to the slide box 10. The motor 5 is fixed on the base 17. The support plate 13 is used to support and connect the contour magnet 15. When the motor 5 is started, the contour magnet 15 is driven to rotate in the opposite direction through the belt 4. The ball of the deep groove ball bearing 18 is in point contact with the outer ring of the bearing, which reduces the energy loss of the motor 5 during the transmission process.

[0032] The main body of the horizontal lathe includes a three-jaw chuck 2 and a tailstock chuck 6, which are used to clamp the lead screw 12 to be processed. The tailstock chuck 6 is fixed on the mobile tailstock 7, which is driven by the slide box 10. By shaking the large handwheel 8 and the small handwheel 9, the mobile tailstock 7 can be controlled to move longitudinally on the slide box 10, so that the tailstock chuck 6 can accurately clamp the lead screw workpieces of different lengths. The spindle box 1 of the main body of the horizontal lathe drives the three-jaw chuck 2 to rotate, thereby driving the lead screw 12 to be processed to rotate.

[0033] See Figure 1-Figure 3, the profiling magnet 15 is a spiral shape that matches the screw thread groove, and a gap of 2-3mm is maintained between the surface of the profiling magnet 15 and the processing surface of the screw 12 to be processed. The profiling magnet 15 includes a magnetic block 151 and a spiral bracket 152. The spiral bracket 152 is provided with a positioning groove 153, and a plurality of magnetic blocks 151 are embedded in the positioning groove 153. The spiral bracket is made of soft magnetic material, such as pure iron, silicon steel, etc.; the magnetic block 151 is cylindrical. The spiral bracket 152 is magnetized by a large number of cylindrical magnetic blocks 151 embedded thereon so that the whole is magnetic. The inner surface and two side surfaces of the profiling magnet 15 can absorb magnetic abrasive particles, which are used to process the spiral inner surface and side surfaces of the screw 12 to be processed. When the screw 12 to be processed and the profiling magnet 15 move relative to each other, the abrasive particles and the screw 12 to be processed rub against each other to process the surface to be processed of the screw 12 to be processed.

[0034] See Figure 1-Figure 3 A method for grinding a screw thread groove by a profiling magnet 15 comprises the following steps:

[0035] 1) The lead screw 12 to be processed passes through the sleeve 14 and is gap-matched with the profiling magnet 15. The distance between the inner surface of the profiling magnet 15 and the surface to be processed of the lead screw 12 to be processed is maintained at 2-3 mm;

[0036] 2) Using the three-jaw chuck 2 and the tailstock chuck 6 to fix the two ends of the lead screw 12 to be processed;

[0037] 3) placing the mobile grinding device at the processing starting point of the lead screw 12 to be processed;

[0038] 4) Mixing water-based polishing liquid and magnetic polishing particles in a ratio of 1:2, and injecting the mixture of polishing liquid and magnetic particles into the gap between the magnet and the lead screw using a syringe;

[0039] 5) Start the switch, the horizontal lathe body and the motor 5 run at the same time, driving the screw 12 to be processed to rotate, and the motor 5 drives the sleeve 14 to rotate in the opposite direction to the screw 12 to be processed, so that the abrasive particles repeatedly grind on the grinding surface of the screw 12 to be processed, improve the grinding accuracy, and achieve the expected grinding effect. While completing the friction work, the mobile grinding device moves to the end of the screw 12 to be processed, and the abrasive particles on the profiling magnet 15 begin to grind the processing surface of the screw 12 to be processed, and the profiling magnet 15 moves to the end of the screw; rotate in the opposite direction, and when the mobile grinding device returns to the processing starting point, a processing cycle is completed. In order to improve the grinding effect, the profiling magnet 15 can be driven by the slide box 10 to make reciprocating motions for many times.

Claims

1. A grinding device for grinding screw thread grooves with a contoured magnet, characterized in that: It includes a horizontal lathe body and a mobile grinding device. The mobile grinding device includes a profile magnet, a motor, a deep groove ball bearing, a belt, a sleeve, and a mobile support frame. The mobile support frame is driven by a slide box to move longitudinally on the horizontal lathe body. The mobile support frame is connected with a sleeve through a deep groove ball bearing. The sleeve is fixedly connected with a profile magnet. The motor is fixed to the mobile support frame. The motor drives the belt, and the belt drives the sleeve to rotate. The horizontal lathe body clamps and fixes the lead screw to be processed, and drives the lead screw to be processed to rotate. The contour magnet comprises a magnetic block and a spiral bracket, the spiral bracket is provided with a positioning groove, a plurality of magnetic blocks are embedded in the positioning groove, and the spiral bracket is made of soft magnetic material; The horizontal lathe body comprises a three-jaw chuck and a tailstock chuck, and the three-jaw chuck and the tailstock chuck are used to clamp the lead screw to be processed; The method for grinding the thread groove of a lead screw by a profiled magnet implemented by the device comprises the following steps: 1) Pass the lead screw to be processed through the sleeve and match it with the contour magnet. The distance between the inner surface of the contour magnet and the surface to be processed of the lead screw to be processed is kept at 2-3mm; 2) Use the three-jaw chuck and tailstock chuck to fix the two ends of the lead screw to be processed; 3) Place the mobile grinding device at the starting point of the lead screw to be processed; 4) Mix the water-based grinding liquid and the magnetic grinding particles in a ratio of 1:2, and inject the mixture of the grinding liquid and the magnetic particles into the gap between the magnet and the lead screw using a syringe; 5) Start the switch, the horizontal lathe body and the motor run at the same time, driving the screw to be processed to rotate, and the motor drives the sleeve to rotate in the opposite direction to the screw to be processed. At the same time, the mobile grinding device moves to the end of the screw to be processed, and the grinding particles on the profiling magnet begin to grind the processing surface of the screw to be processed, and the profiling magnet moves to the end of the screw; rotate in the opposite direction, and when the mobile grinding device returns to the processing starting point, a processing cycle is completed.

2. A grinding device for grinding screw thread grooves with a contoured magnet according to claim 1, characterized in that: The magnetic block is cylindrical.

3. A grinding device for grinding screw thread grooves with a contoured magnet according to claim 1, characterized in that: The profiling magnet is in a spiral shape matching the screw thread groove, and a gap of 2-3 mm is maintained between the surface of the profiling magnet and the processing surface of the screw to be processed.

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