Internal thread grinding apparatus

Abstract

This application provides an internal thread grinding device, including a rotary clamping mechanism mounted on a worktable. Grinding devices that move laterally and longitudinally are respectively arranged on the left and right sides of the rotary clamping mechanism. The grinding devices are mounted on a platform located on one side of the worktable. At least one platform includes at least two different workstations that can be rotated and switched. The workstations are switched by rotating the platform horizontally. Each workstation includes a coarse grinding wheel workstation for mounting a coarse grinding wheel and a fine grinding wheel workstation for mounting a fine grinding wheel. The platform is also slidably connected to guide rails arranged laterally and longitudinally. The platform is connected to a transverse moving platform that moves along the transverse guide rail and a longitudinal moving platform that moves along the longitudinal guide rail. The coarse grinding wheel grinds the workpiece by moving in the same direction. This application improves the efficiency and grinding quality of grinding the workpiece by integrating multiple grinding stations.

Description

Technical Field

[0001] This application relates to the field of metal cutting machine tools, and more particularly to an internal thread grinding device. Background Technology

[0002] In the grinding process of the internal threads of lead screw nuts, traditional processes typically use a single grinding head with different grinding depths to grind the workpiece. While this method can meet the processing needs of ordinary workpieces, it cannot meet the processing requirements of high-precision lead screw nuts. For example, planetary roller lead screws, which play a crucial role in humanoid robots, require extremely high precision in their nuts during practical applications. To meet grinding precision requirements, some technologies divide the grinding process into two steps: rough grinding and finish grinding. The rough grinding stage primarily aims to quickly remove excess material, while finish grinding focuses on achieving the final dimensional accuracy and surface quality. Currently, these two processes are usually performed separately, requiring the switching of the grinding head or a secondary unloading of the workpiece. This separate processing method leads to production interruptions, increases the number of times the workpiece is repeatedly clamped, aligned, and the equipment is adjusted, significantly reducing overall grinding efficiency, extending the processing cycle, and easily causing accumulated errors from multiple positioning steps, affecting the consistency of the thread profile, surface roughness, and dimensional stability, ultimately limiting the reliability of product quality and the economy of the processing process. Utility Model Content

[0003] This application provides an internal thread grinding device to solve the problems of low grinding efficiency, low grinding accuracy, and poor quality in the grinding process of internal threads of lead screw nuts.

[0004] Specifically, the following technical solutions are included:

[0005] This application provides an internal thread grinding device, including a rotary clamping mechanism on a worktable. Grinding devices that move laterally and longitudinally are respectively arranged on the left and right sides of the rotary clamping mechanism. The grinding devices are arranged on a platform located on one side of the worktable. At least one platform includes at least two different platform stations that can be switched by rotation. The platform stations are switched by rotating the platform in the horizontal direction. Each platform station includes a coarse grinding wheel station for mounting a coarse grinding wheel and a fine grinding wheel station for mounting a fine grinding wheel. The platform is provided with a platform driving device for driving the platform to move laterally and longitudinally. The platform is connected to a transverse moving platform that moves along a transverse guide rail and a longitudinal moving platform that moves along a longitudinal guide rail. The coarse grinding wheel grinds the workpiece by moving in the same direction. The platform is connected to a guide rail arranged laterally and is also connected to a guide rail arranged longitudinally through the transverse guide rail; or, the platform is connected to a guide rail arranged longitudinally and is also connected to a guide rail arranged laterally through the longitudinal guide rail.

[0006] Optionally, the grinding wheel of the grinding device on one side of the worktable is a coarse grinding wheel and a fine grinding wheel, and the grinding wheel of the grinding device on the other side of the worktable is a coarse grinding wheel.

[0007] Optionally, the platform stations located on the same platform are perpendicular to each other;

[0008] Optionally, the platform drive device is mounted on the platform.

[0009] Optionally, the platform is provided with a horizontal rotation drive device that rotates in the horizontal direction, and the horizontal rotation drive device is mounted on the platform.

[0010] Optionally, one side of the rotary clamping mechanism is provided with a rough grinding dressing disc for dressing the grinding device.

[0011] Optionally, a finely ground dressing disc wheel is also provided on one side of the rotary clamping mechanism.

[0012] Optionally, the fine grinding and dressing disc wheel and the coarse grinding and dressing disc wheel can be switched between their respective positions by the lateral movement of the platform.

[0013] Optionally, the stage is further provided with a calibration station, which is equipped with a calibration device for determining the initial working position of the workpiece to be processed.

[0014] Optionally, the calibration device includes a probe for detecting the position of the workpiece to be processed, and a reference plate for calibrating the reference position is also provided on one side of the rotary clamping mechanism.

[0015] This application provides an internal thread grinding device, including a rotary clamping mechanism on a worktable. Grinding devices that move laterally and longitudinally are respectively arranged on the left and right sides of the rotary clamping mechanism. The grinding devices are mounted on a platform located on one side of the worktable. At least one platform includes at least two different platform stations that can be switched by rotation. The platform stations are switched by rotating the platform horizontally. Each platform station includes a coarse grinding wheel station for mounting a coarse grinding wheel and a fine grinding wheel station for mounting a fine grinding wheel. The platform is also slidably connected to guide rails arranged laterally and longitudinally. The platform is equipped with a platform driving device for driving the platform to move laterally and longitudinally. The coarse grinding wheel grinds the workpiece by moving in the same direction. This application integrates a multi-station automatic conversion mechanism on a single machine tool, achieving continuous and seamless processing of coarse grinding, fine grinding, and other processes, avoiding repeated clamping of the workpiece, significantly shortening the processing cycle and improving efficiency. Automated station switching ensures the consistency of the spindle reference, effectively maintaining machining accuracy while simplifying the operation process and reducing labor costs. This provides an efficient and reliable solution for the flexible production of high-precision, multi-variety internal thread parts. Furthermore, because the coarse grinding wheels on both sides grind the workpiece in the same direction, this grinding method ensures that the left and right sides of the internal thread are under consistent cutting conditions, eliminating the inherent clockwise / counter-clockwise asymmetry of opposing grinding. This results in a more uniform distribution of tooth flank surface roughness, residual stress field, and thermal damage. Simultaneously, the wear trend of the profiles on both sides of the forming grinding wheel is consistent, the tooth angle is less prone to distortion, and the drift patterns of the pitch diameter and half-angle are easier to predict and compensate for, significantly improving process controllability and batch consistency. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] Figure 1 A structural schematic diagram of the first type of automatic internal thread grinding equipment provided in this application;

[0018] Figure 2 A structural schematic diagram of the second type of automatic internal thread grinding equipment provided in this application;

[0019] Figure 3 A top view of an automatic internal thread grinding device provided in this application;

[0020] Figure 4 Left view of an automatic internal thread grinding device provided in this application.

[0021] Figure label:

[0022] Rotary clamping mechanism 1;

[0023] Grinding device 2; coarse grinding wheel 21; fine grinding wheel 22;

[0024] Workbench 3;

[0025] Table 4; Rough grinding wheel station 41; Fine grinding wheel station 42; Calibration station 43;

[0026] Dressing disc wheel 5; coarse grinding dressing disc wheel 51; fine grinding dressing disc wheel 52;

[0027] Calibration device 6; Probe 61;

[0028] Reference plate 71;

[0029] Guide rail 8;

[0030] Lateral movement platform 9;

[0031] Vertical moving platform A.

[0032] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0033] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0034] Planetary roller screws are crucial components of humanoid robots, directly determining the flexibility of their joints and consequently their motion performance. As high-precision components, the grinding process of the internal threads of planetary roller screws directly impacts the performance of the workpiece being processed. Currently, there are two main technical modes for grinding the internal threads of screw nuts: one is to use a single-grit grinding wheel to grind the workpiece through multiple passes. This mode eliminates the need to switch grinding heads, but suffers from lower grinding accuracy, failing to meet the requirements of high-precision screw nut internal thread grinding; the other is the traditional split-processing method, which separates rough grinding and fine grinding. However, rough grinding and fine grinding must be completed twice on different machines, resulting in low efficiency and repetitive positioning errors. In terms of processing quality and efficiency, split-processing inevitably introduces positioning errors due to the secondary clamping, affecting accuracy consistency, and the significant inter-process turnover severely hinders efficiency.

[0035] In view of this, this application provides an internal thread grinding device, which integrates at least two stage stations on at least one side of the stage, including at least a rough grinding wheel station and a fine grinding wheel station. The different stage stations can be switched by rotating the stage, meaning that the entire grinding process of the workpiece can be completed without secondary clamping. This approach saves time on secondary clamping, improving grinding efficiency, and also enhances grinding consistency and the grinding quality of the workpiece.

[0036] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0037] Figures 1-4 This is a schematic diagram of the internal thread grinding equipment provided in this application, as shown below. Figures 1-4 As shown, the internal thread grinding equipment provided in this application includes a rotary clamping mechanism 1 disposed on a worktable 3. Grinding devices 2, which move laterally and longitudinally, are respectively disposed on the left and right sides of the rotary clamping mechanism 1. The grinding devices 2 are disposed on a platform 4 located on one side of the worktable 3. At least one platform 4 includes at least two different platform positions that can be switched by rotation. The platform positions are switched by rotating the platform 4 in the horizontal direction. The platform positions include a coarse grinding wheel position 41 for mounting a coarse grinding wheel 21 and a fine grinding wheel position 42 for mounting a fine grinding wheel 22. The platform 4 is provided with useful... A platform driving device drives the platform 4 to move in the transverse and longitudinal directions. The platform 4 is connected to a transverse moving platform 9 that moves along the transverse guide rail 8 and a longitudinal moving platform A that moves along the longitudinal guide rail 8. The coarse grinding wheel 21 grinds the workpiece to be processed by moving in the same direction. The platform 4 is connected to the guide rail 8 arranged in the transverse direction and is connected to the guide rail 8 arranged in the longitudinal direction through the guide rail 8. Alternatively, the platform 4 is connected to the guide rail 8 arranged in the longitudinal direction and is connected to the guide rail 8 arranged in the transverse direction through the guide rail 8 arranged in the longitudinal direction.

[0038] This application does not limit the specific structure of the above-mentioned rotary clamping mechanism 1. Those skilled in the art can implement it by referring to the prior art, that is, it can be any clamping mechanism that can effectively clamp the workpiece to be processed and provide it with rotational power.

[0039] The grinding device 2 described above may include, for example, a coarse grinding wheel 21 and a fine grinding wheel 22. The difference between the coarse grinding wheel 21 and the fine grinding wheel 22 is their grit number; the coarse grinding wheel 21 has a smaller grit number, while the fine grinding wheel 22 has a larger grit number. This application does not limit the specific grit number of the fine grinding wheel 22 and the coarse grinding wheel 21; those skilled in the art can set them according to their needs.

[0040] The aforementioned stage driving device may include, for example, a motor, which drives the stage 4 to move laterally and longitudinally. The motor referred to here can be a servo motor or a direct-drive motor; this application does not limit its application.

[0041] Figure 1 The diagram illustrates the structure of an internal thread grinding machine, with one side of the grinding device 2 including a coarse grinding wheel 21 and a fine grinding wheel 22, and the platform 4 including a coarse grinding wheel station 41 and a fine grinding wheel station 42, and the other side of the grinding device 2 including a coarse grinding wheel 21 and the platform 4 including a coarse grinding wheel station 41.

[0042] The grinding devices 2 on both sides of the rotary clamping mechanism 1 can grind the workpiece simultaneously in the same direction or simultaneously in opposite directions. When grinding in the same direction, for example, one grinding device 2 can grind from one end of the workpiece, while the other grinding device 2 can start grinding from the middle of the workpiece. When grinding in opposite directions, for example, the grinding devices 2 on both sides can start grinding from both ends respectively.

[0043] The platform 4 can be directly connected to the guide rail 8 arranged in the transverse direction, or connected via the guide rail 8 arranged in the transverse direction and the guide rail 8 arranged in the longitudinal direction; or the platform 4 can be as follows: Figure 1 The device shown is directly connected to the guide rail 8 arranged along the longitudinal direction. It is connected by the guide rail 8 arranged along the longitudinal direction and the guide rail 8 arranged along the transverse direction. This application does not limit it.

[0044] In this implementation, if grinding of the workpiece is required, the operator can first place the workpiece on the rotary clamping mechanism 1, allowing the rotary clamping mechanism 1 to effectively clamp the workpiece and provide rotational power to rotate it axially. Subsequently, the coarse grinding wheel station 41 carries the coarse grinding wheel 21 to the working position. The coarse grinding wheel 21 on the platform 4 is aligned with the workpiece by controlling the transverse moving platform 9 and the longitudinal moving platform A. Then, the coarse grinding wheel 21 is started to perform coarse grinding on the workpiece. Next, the fine grinding wheel station 42 is moved to the working position by switching the platform positions, aligning with the coarsely ground workpiece. Finally, the fine grinding wheel 22 performs fine grinding on the workpiece until the grinding is complete.

[0045] The implementation method provided in this embodiment integrates rough grinding and fine grinding into a single enclosed device, enabling all grinding processes to be completed in a single clamping of the workpiece. This not only completely eliminates the auxiliary time spent on transferring, waiting, and repeatedly clamping and positioning the workpiece between different devices, significantly shortening the cycle time for single-piece processing, but also allows the entire process to be seamlessly connected and continuously automated. The device can automatically select different grinding wheels according to a preset program and execute processing and dressing actions in the optimal sequence, greatly improving equipment utilization and production automation levels, providing a hardware foundation for large-scale, flexible manufacturing. Furthermore, a single clamping ensures the uniqueness of the reference for all grinding processes, fundamentally eliminating concentricity and positional errors caused by reference conversion, ensuring high geometric accuracy of the threads, and resulting in good repeatability and reliability of parts in mass production.

[0046] Furthermore, since the coarse grinding wheels 21 on both sides grind the workpiece in the same direction, this grinding method puts the left and right tooth sides of the internal thread in a consistent cutting state, eliminating the inherent clockwise / counterclockwise asymmetry of opposing grinding. This results in a more uniform tooth side surface roughness, residual stress field, and thermal damage distribution. At the same time, the wear trend of the contours on both sides of the forming grinding wheel is consistent, the tooth angle is less likely to be distorted, and the drift law of the pitch diameter and half angle is easier to predict and compensate, significantly improving process controllability and batch consistency.

[0047] Optionally, in some embodiments, the platform 4 may include a coarse grinding wheel station 41 for mounting the coarse grinding wheel 21 and a fine grinding wheel station 42 for mounting the fine grinding wheel 22. That is, both sides of the platform 4 of the rotating clamping mechanism 1 include a coarse grinding wheel station 41 and a fine grinding wheel station 42. With this implementation, the all-round and full-process processing of the workpiece to be processed can be realized more comprehensively, improving processing efficiency and processing quality, and ensuring the consistency of the workpiece to be processed.

[0048] Optionally, in some embodiments, the grinding wheels of the grinding device 2 on one side of the worktable are a coarse grinding wheel 21 and a fine grinding wheel 22, while the grinding wheel of the grinding device 2 on the other side of the worktable is a coarse grinding wheel 21. In this implementation, after the coarse grinding wheels 21 on both sides complete coarse grinding in the same direction under the control of the control device, the platform on one side rotates to change its position, transforming into a fine grinding wheel 22 for grinding, thus achieving full-process fine grinding from one end of the workpiece to the other. This implementation allows for a smooth connection between the coarse grinding tool setting position and the fine grinding process, further improving the grinding quality of the workpiece.

[0049] The stage positions located on the same stage 4 can be perpendicular to each other, or at 180 degrees, or at other angles. This application does not limit them, and those skilled in the art can set them according to their needs. When the stage positions on the same stage 4 are perpendicular to each other, it is possible to install as many stage positions as possible while ensuring that the stage positions do not interfere with each other, thereby improving the usability of the grinding equipment provided by this application.

[0050] Optionally, the stage drive unit can be mounted on the stage 4. This stage drive unit may include, for example, a drive motor, which can be a servo motor or a direct-drive motor. When the stage drive unit is mounted on the stage 4, it can provide more direct power to the stage 4, shorten the power transmission chain, and improve the availability of the grinding equipment.

[0051] Optionally, the platform 4 is equipped with a horizontal rotation drive device that can rotate in the horizontal direction, and the horizontal rotation drive device is mounted on the platform 4. The horizontal rotation drive device may include, for example, a drive motor. The horizontal rotation drive device drives the switching between different platform workstations. This implementation method can ensure smooth switching between various workstations, improving equipment reliability and availability.

[0052] Optionally, in some embodiments, a coarse grinding dressing disc 51 and / or a fine grinding dressing disc 52 for dressing the grinding device 2 may be provided on one side of the rotary clamping mechanism 1. Alternatively, coarse grinding dressing discs 51 and / or fine grinding dressing discs 52 may be provided on both sides of the rotary clamping mechanism 1. Optionally, the fine grinding dressing disc 52 and the coarse grinding dressing disc 51 can be switched between their positions by the lateral movement of the platform 4. In this implementation, when the coarse grinding wheel 21 needs to be dressed, the platform drive device controls the longitudinal moving platform A and the lateral moving platform 9 to move, so that the coarse grinding wheel 21 is aligned with the coarse grinding dressing disc 51, and the coarse grinding dressing disc 51 dresses the coarse grinding wheel 21. When the grinding wheel 22 needs to be dressed, the stage drive device controls the longitudinal moving platform A and the transverse moving platform 9 to move, so that the grinding wheel 22 is aligned with the grinding dressing disc wheel 52, and the grinding dressing disc wheel 52 dresses the grinding wheel 22. Figure 1 This is a schematic diagram of an internal thread grinding machine, where one side of the dressing disc wheel includes a rough grinding dressing disc wheel 51 and a fine grinding dressing disc wheel 52, while the other side only includes a rough grinding dressing disc wheel 51.

[0053] By setting up the coarse grinding dressing disc 51 and / or the fine grinding dressing disc 52, the internal thread grinding equipment provided in this application can complete the grinding task in the whole process while dressing the grinding wheel, without having to remove the grinding wheel for dressing. This improves the overall processing efficiency, further expands the applicable scenarios of the internal thread grinding equipment, and enhances its usability.

[0054] Optionally, in some embodiments, the stage 4 may also be provided with a calibration station 43, which is equipped with a calibration device 6 for determining the initial working position of the workpiece to be processed. This implementation method can further improve the accuracy of grinding. Compared with the prior art method of directly performing grinding by preset position, this method of determining the initial working position of the workpiece to be processed by calibration device 6 has higher accuracy, ensuring high accuracy based on calibration for each processing, improving the quality of the workpiece to be processed obtained by grinding, and mitigating positional errors caused by different processing cycles.

[0055] Optionally, the calibration device 6 may include, for example, a probe 61 for detecting the position of the workpiece to be processed, and a reference plate 71 for calibrating the reference position is also provided on one side of the rotating clamping mechanism 1. The probe 61 mentioned here may be, for example, a contact trigger probe or a contact scanning probe, or other probes, such as a non-contact probe. In this implementation, when position calibration is required, the probe 61 is first controlled to contact the reference plate 71 for calibration, and then the probe 61 is made to contact the workpiece to be processed, thereby determining the position of the workpiece. This method is simple, feasible, and easy to operate, possessing good practicality and usability.

[0056] The following is a schematic diagram of the working process of an internal thread grinding device provided in this application, taking a workpiece with a 3-threaded surface, one side having a coarse grinding wheel 21 and a fine grinding wheel 22, and the other side having a coarse grinding wheel 21. One side includes a coarse grinding dressing disc wheel 51 and a fine grinding dressing disc wheel 52, and the other side includes a coarse grinding dressing disc wheel 51. Optionally, in some embodiments, after the rotary clamping mechanism 1 clamps the workpiece, the processing steps of the internal thread grinding device may include, for example, the following steps:

[0057] 1. Rotate the stage 4 to rotate the probe 61 assembly to the working position. First, calibrate the probe 61 through the reference plate 71, and then use the probe 61 to strike the end face of the workpiece to be processed to determine the starting point of grinding the workpiece.

[0058] 2. The grinding head of the coarse grinding wheel 21 rotates to the working position, and the grinding heads of the left and right coarse grinding wheels 21 move to the corresponding coarse grinding dressing discs 51, where the corresponding coarse grinding dressing discs 51 dress the grinding heads of the coarse grinding wheels 21. The control device calculates the shape of the grinding wheel through an algorithm, and then controls the coarse grinding wheel 21 to move along the X and Z axes, thereby realizing the interpolation dressing of the coarse grinding wheel 21 based on the coarse grinding dressing discs 51, and dressing the contour of the coarse grinding wheel 21.

[0059] 3. The right coarse grinding wheel 21 moves to the initial processing position of the workpiece to be processed, and the left coarse grinding wheel 21 moves to the middle position of the workpiece to be processed.

[0060] (1) The left rough grinding wheel 21 first moves rapidly into the middle of the workpiece to be processed. Then the left and right rough grinding wheels 21 together slowly cut into the predetermined depth;

[0061] (2) Then the left coarse grinding wheel 21 retracts, while the right coarse grinding wheel 21 begins to enter the grinding process. The two move synchronously to achieve the grinding effect based on the following... Figure 1 Interpolation motion in the Z-axis and C-axis (rotation axis direction of rotary clamping mechanism 1) directions shown;

[0062] (3) When the right coarse grinding wheel 21 arrives at the starting point where the left coarse grinding wheel 21 is located, the left coarse grinding wheel 21 has completed the thread grinding of the left half.

[0063] (4) The right coarse grinding wheel 21 continues to feed one pitch, completely covering the joint of the left and right coarse grinding wheels 21;

[0064] (5) Grinding is complete.

[0065] 4. When the workpiece reaches the predetermined position, the coarse grinding wheels 21 on the left and right sides feed along the X and Z axes. The rotary clamping mechanism 1 rotates with the C axis as the rotation axis. The three-axis interpolation is performed. The coarse grinding wheels 21 grind to the predetermined depth (cut depth) through one pitch, and then the grinding begins.

[0066] It should be noted that since the coarse grinding wheel 21 on the left starts grinding from the middle of the workpiece, if it is fed directly by transverse feed (radial of the workpiece), the coarse grinding wheel 21 will directly penetrate into the workpiece to the predetermined depth, which may cause damage to the grinding wheel and leave a mark at the cutting position. Therefore, it is necessary to start grinding by slowly cutting into the workpiece to the predetermined depth.

[0067] 5. During the grinding process, thread grinding is achieved through the interpolation motion of the C-axis and Z-axis. For every 360° rotation of the C-axis, the rough grinding wheel 21 advances one thread pitch in the Z-axis machining direction.

[0068] 6. After the thread is ground to the first depth of cut, the rough grinding wheel 21 returns to the initial machining position. Repeat steps 4, 5, and 6 until the thread is ground to the predetermined depth.

[0069] If the grinding wheel is single-toothed, both the roughing grinding wheel 21 and the fine grinding wheel 22 can be multi-toothed grinding wheels, with the number of tooth protrusions on both wheels equal to the number of pitch heads on the workpiece. The fine grinding wheel 22 is a bent-bar grinding head.

[0070] 7. After grinding one thread, the two coarse grinding wheels 21 return to their initial machining positions. The C-axis, where the rotating clamping mechanism 1 is located, first returns to its initial positioning position. Then the C-axis rotates 120° and positions itself to the second thread position (as mentioned above, the internal thread consists of three threads), and steps 4, 5, 6, and 7 are repeated.

[0071] 8. After the second thread is ground, the two rough grinding wheels 21 return to their initial machining positions. The C-axis, where the rotating clamping mechanism 1 is located, returns to its initial positioning position. Then the C-axis rotates 120° to position itself at the third thread, and steps 4, 5, 6, and 7 are repeated.

[0072] 9. After the three-thread grinding is completed, the two rough grinding wheels 21 return to their initial machining positions. The C-axis returns to its initial positioning position.

[0073] 10. By rotating the stage 4, the fine grinding wheel 22 is switched to the working position. Through the interpolation motion of the X-axis and Z-axis, the fine grinding dressing disc wheel 52 dresses the fine grinding wheel 22 to the predetermined shape.

[0074] 11. After dressing, the fine grinding wheel 22 moves to the initial machining position, and then performs internal thread grinding through the interpolation motion of the C-axis and Z-axis. For every 360° rotation of the C-axis, the Z-axis advances by one thread pitch. The fine grinding wheel 22 completes the fine grinding of the internal thread of the entire workpiece from right to left.

[0075] 12. After the thread is ground to the first depth of cut, the fine grinding wheel 22 returns to the initial machining position and advances the X-axis by one grinding depth to perform the second depth of cut grinding of the thread raceway until the fine thread raceway is finely ground to the required dimensions.

[0076] 13. After grinding the first thread, the fine grinding wheel 22 is returned to the initial machining position, the C-axis returns to the initial positioning position, and then the C-axis is rotated 120° to perform fine grinding of the second thread, until all three threads are ground to the required dimensions.

[0077] It should be noted that the above grinding process is only an exemplary embodiment with a 3-threaded workpiece as an example. In the actual grinding process, the workpiece can be machined with any number of threads. Grinding of different types of workpieces can be achieved by setting different processing parameters.

[0078] Furthermore, when the workpiece to be processed has multi-start threads, the specific processing procedure can be to complete the processing of one thread before processing the other thread; or, it can be to uniformly remove the allowance for each thread at each grinding depth until each thread is ground to its proper position. This application does not limit the specific implementation method, and those skilled in the art can flexibly adjust the grinding process by setting parameters.

[0079] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0080] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A female thread grinding apparatus comprising a rotary chucking mechanism provided on a table, grinding devices which move in a lateral direction and a longitudinal direction being provided on both sides of the rotary chucking mechanism, characterized in that, The grinding device is mounted on a platform located on one side of the worktable. At least one platform includes at least two different platform stations that can be switched by rotation. The platform stations are switched by rotating the platform in the horizontal direction. Each platform station includes a coarse grinding wheel station for mounting a coarse grinding wheel and a fine grinding wheel station for mounting a fine grinding wheel. The platform is equipped with a platform driving device for driving the platform to move in the transverse and longitudinal directions. The platform is connected to a transverse moving platform that moves along a transverse guide rail and a longitudinal moving platform that moves along a longitudinal guide rail. The coarse grinding wheel grinds the workpiece by moving in the same direction. The platform is connected to a guide rail arranged in the transverse direction and is also connected to a guide rail arranged in the longitudinal direction through the transverse guide rail; or, the platform is connected to a guide rail arranged in the longitudinal direction and is also connected to a guide rail arranged in the transverse direction through the longitudinal guide rail.

2. The internal thread grinding equipment as described in claim 1, characterized in that, The grinding wheels of the grinding device on one side of the worktable are coarse grinding wheels and fine grinding wheels, while the grinding wheels of the grinding device on the other side of the worktable are coarse grinding wheels.

3. The internal thread grinding equipment as described in claim 1, characterized in that, The platform stations located on the same platform are perpendicular to each other.

4. The internal thread grinding equipment as described in claim 1, characterized in that, The platform drive device is mounted on the platform.

5. The internal thread grinding equipment as described in claim 1, characterized in that, The platform is equipped with a horizontal rotation drive device that rotates in the horizontal direction, and the horizontal rotation drive device is mounted on the platform.

6. The internal thread grinding equipment as described in claim 1, characterized in that, One side of the rotary clamping mechanism is provided with a rough grinding dressing disc for dressing the grinding device.

7. The internal thread grinding equipment as described in claim 6, characterized in that, One side of the rotary clamping mechanism is also provided with a finely ground dressing disc wheel.

8. The internal thread grinding equipment as described in claim 7, characterized in that, The fine grinding and dressing disc wheel and the coarse grinding and dressing disc wheel are switched between their respective positions by the lateral movement of the platform.

9. The internal thread grinding equipment as described in claim 1, characterized in that, The platform is also equipped with a calibration station, which is equipped with a calibration device for determining the initial working position of the workpiece to be processed.

10. The internal thread grinding equipment as described in claim 9, characterized in that, The calibration device includes a probe for detecting the position of the workpiece to be processed, and a reference plate for calibrating the reference position is also provided on one side of the rotary clamping mechanism.

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