Internal thread grinding apparatus

Abstract

The application provides an internal thread grinding device, which comprises a rotary clamping mechanism arranged on a workbench, grinding devices arranged on the left and right sides of the rotary clamping mechanism, and at least one carrier arranged on one side of the workbench. The at least one carrier comprises at least two different carrier stations which are switched by movement. The carrier stations are switched by rotation of the carrier in the horizontal direction. The carrier stations comprise a rough grinding wheel station and a fine grinding wheel station. At least one side of the rotary clamping mechanism is further provided with a dressing disc wheel for dressing the grinding devices. Before grinding, the rough grinding wheel arranged on the rough grinding wheel station and the fine grinding wheel arranged on the fine grinding wheel station are dressed according to a preset profile. The rough grinding wheel station, the fine grinding wheel station and the dressing disc wheel are integrated on the grinding device, so that the processing of the workpiece in the whole process can be realized integrally, and the grinding efficiency and quality are improved.

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] The field of humanoid robots is developing rapidly, and planetary roller screws, as key components of humanoid robots, play a crucial role in their performance. As precision transmission components, the planetary roller screw nut requires extremely high precision in the grinding of its internal threads, typically involving multiple grinding processes. Current grinding methods mostly employ multi-wheel grinding with a single grinding wheel. This method, because it does not differentiate between grinding precision, suffers from poor grinding quality and low grinding efficiency. Grinding methods that differentiate between rough and fine grinding exist; however, these methods require equipment switching, which reduces grinding efficiency and introduces operational errors, resulting in poor grinding effects. Summary of the Invention

[0003] This application provides an internal thread grinding device to solve the problems of low grinding efficiency, low grinding accuracy, and poor effect 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 on the left and right sides of the rotary clamping mechanism, respectively. The grinding devices are mounted on a platform located on one side of the worktable. At least one of the grinding devices includes at least two different platform positions that can be switched by movement. The platform positions are switched by rotating the platform in the horizontal direction. The platform positions include a rough grinding wheel position and a fine grinding wheel position. At least one side of the rotary clamping mechanism is also provided with a dressing disc wheel for dressing the grinding devices. The application also includes a control device connected to the rotary clamping mechanism, the grinding devices, and the dressing disc wheel. The control device controls the transverse feed and longitudinal feed of the grinding devices and the rotational speed of the rotary clamping mechanism according to a preset calculation method and data. Before grinding, the control device controls the dressing disc wheel to dress and grind the rough grinding wheel on the rough grinding wheel position and the fine grinding wheel on the fine grinding wheel position according to a preset profile.

[0006] Optionally, the dressing disc wheel includes a fine grinding dressing disc wheel and a coarse grinding dressing disc wheel, wherein the coarse grinding dressing disc wheel consists of two grinding devices arranged in opposite directions and symmetrically facing the left and right sides of the rotating clamping mechanism.

[0007] Optionally, the stage is also provided with a calibration station, which is equipped with a calibration device for determining the initial working position of the workpiece to be processed. The control device determines the initial working position and grinding depth of the grinding device on the left and right sides of the rotary clamping mechanism according to a preset calculation method and data.

[0008] 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.

[0009] Optionally, the control device determines the initial working position of the grinding device by detecting the position data of the reference plate and the position data of the workpiece to be processed, and determines the motion trajectory of the grinding device according to the preset processing data of the workpiece to be processed.

[0010] Optionally, the platform is provided with a platform driving device for driving the platform to move in the lateral and longitudinal directions, and the platform driving device is mounted on the platform; the platform is connected to a guide rail arranged in the lateral direction, and is also connected to a guide rail arranged in the longitudinal direction through the lateral direction 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 lateral direction through the longitudinal direction guide rail.

[0011] Optionally, the grinding devices arranged on both sides of the rotary clamping mechanism each include a coarse grinding wheel and a fine grinding wheel that respectively enter the working position by rotating in the horizontal direction.

[0012] 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.

[0013] Optionally, the platforms on both sides of the rotary clamping mechanism are each provided with a coarse grinding wheel station and a fine grinding wheel station that respectively enter the working position by rotating in the horizontal direction.

[0014] Optionally, the platform stations located on the same platform are perpendicular to each other.

[0015] The internal thread grinding equipment provided in this application includes a rotary clamping mechanism on a worktable, grinding devices that move laterally and longitudinally on the left and right sides of the rotary clamping mechanism, respectively. The grinding devices are mounted on a platform located on one side of the worktable. At least one of the grinding devices includes at least two different platform positions that can be switched by movement. The platform positions are switched by rotating the platform in the horizontal direction. The platform positions include a rough grinding wheel position and a fine grinding wheel position. At least one side of the rotary clamping mechanism is also provided with a dressing disc wheel for dressing the grinding devices. The equipment also includes a control device connected to the rotary clamping mechanism, the grinding devices, and the dressing disc wheel. The control device controls the transverse feed and longitudinal feed of the grinding devices and the rotational speed of the rotary clamping mechanism according to a preset calculation method and data. Before grinding, the control device controls the dressing disc wheel to dress and grind the rough grinding wheel on the rough grinding wheel position and the fine grinding wheel on the fine grinding wheel position according to a preset profile. This application achieves fully automated continuous machining of internal thread grinding by integrating a roughing grinding wheel, a fine grinding wheel, and a dressing disc wheel on a single machine. The distinction between the roughing and fine grinding wheels enhances the precision of the entire grinding process, further improving the grinding effect on the workpiece. Furthermore, the roughing wheel quickly removes excess material, the fine grinding wheel completes the final contour and surface finishing, and the dressing disc wheel can precisely dress the grinding wheel online, ensuring it remains in optimal grinding condition. This integrated design eliminates errors caused by multiple workpiece clamping and equipment switching, significantly improving grinding efficiency and cycle time. Simultaneously, because wheel dressing and grinding are performed in real-time on the same machine, the sharpness and shape accuracy of the grinding wheel are effectively controlled, thereby significantly improving the dimensional consistency, surface finish, and contour accuracy of the threads. This is particularly suitable for the stable mass production of high-precision ball screw nuts such as planetary roller ball screw nuts, thus providing strong technical support for the field of humanoid robots. 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 schematic diagram of the structure of the first type of internal thread grinding equipment provided in this application;

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

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

[0020] Figure 4Left view of an 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] 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

[0031] 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.

[0032] In the field of precision machinery manufacturing, lead screws and nuts are core components of various high-precision transmission mechanisms (such as CNC machine tools, aerospace, and medical devices). Especially in the field of humanoid robots, the grinding quality of the internal threads of planetary roller screws directly determines the transmission accuracy, motion smoothness, and service life of the screw pair, and also directly determines the performance of the humanoid robot. Currently, the typical grinding process for internal threads in the industry usually involves using a single-grit grinding wheel to grind the workpiece multiple times to obtain a workpiece that meets the requirements. However, this grinding method, due to the use of a single-grit grinding wheel, suffers from low grinding accuracy, making it difficult to meet the current processing requirements of high-precision internal thread workpieces.

[0033] Some processing techniques differentiate between grinding wheels: First, a coarser grinding wheel is used on a dedicated rough grinding machine to remove excess material and initially form the thread profile. Then, the workpiece is disassembled and transferred to a fine grinding machine, where a finer grinding wheel is used for precision shaping and finishing to achieve the dimensional tolerances, surface roughness, and contour accuracy required by the drawings. The difference between the coarse and fine grinding wheels lies in their grit size. This process leads to several systemic technical problems. First, processing efficiency is low: the transfer of the workpiece between different machines, multiple clamping and alignment processes consume significant auxiliary time, severely prolonging the production cycle and making it difficult to meet the demands of mass production. Second, processing accuracy is difficult to guarantee consistently: multiple clamping inevitably introduces repetitive positioning errors, disrupting the uniformity of the thread machining datum, making it difficult to control the cumulative errors in the thread pitch and diameter, and potentially affecting the perpendicularity of the thread axis to the nut end face. Furthermore, equipment and space costs are high: companies need to purchase and maintain multiple single-function specialized machine tools, occupying a large amount of production space, and the overall level of automation and intelligence is low, with a high dependence on operator skills. These problems collectively restrict further improvements in the consistency, reliability, and economy of high-precision lead screw nuts.

[0034] In view of this, this application provides an internal thread grinding equipment. This equipment first distinguishes between rough grinding and fine grinding, and integrates rough grinding, fine grinding and grinding wheel dressing functions into a single device. This enables high-precision machining of multiple processes in one clamping, which not only eliminates repeated positioning errors and significantly improves machining consistency, but also simplifies operation, reduces energy consumption, and effectively ensures the efficiency of mass production and the reliability of long-term operation.

[0035] 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.

[0036] Figures 1-4 This is a schematic diagram of the internal thread grinding equipment provided in this application. Figures 1-4As shown, the internal thread grinding equipment provided in this application includes a rotary clamping mechanism 1 mounted on a worktable 3. Grinding devices 2, which move laterally and longitudinally, are respectively mounted on the left and right sides of the rotary clamping mechanism 1. The grinding devices 2 are mounted 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 movement. The platform positions are switched by rotating the platform 4 in the horizontal direction. The platform positions include a rough grinding wheel position 41 and a fine grinding wheel position 42. The rotary clamping mechanism... At least one side of 1 is also provided with a dressing disc wheel 5 for dressing the grinding device 2, and also includes a control device connected to the rotary clamping mechanism 1, the grinding device 2, and the dressing disc wheel 5. The control device controls the transverse feed, longitudinal feed and the rotation speed of the rotary clamping mechanism 1 of the grinding device 2 according to the preset calculation method and data, and dresses the coarse grinding wheel 21 set on the coarse grinding wheel station 41 and the fine grinding wheel 22 set on the fine grinding wheel station 42 according to the preset contour before the grinding process.

[0037] 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.

[0038] The aforementioned grinding device 2 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 lies in 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 it according to their needs. The grinding devices 2 on both sides of the worktable 3 may each include a coarse grinding wheel 21 and a fine grinding wheel 22; or, the grinding device 2 on one side of the worktable may include both a coarse grinding wheel 21 and a fine grinding wheel 22, while the other side may only include a coarse grinding wheel 21, excluding the fine grinding wheel 22. In the former implementation, after both sides have simultaneously completed the coarse grinding process, both sides simultaneously switch to the fine grinding wheel station 42, where the fine grinding wheels 22 on both sides simultaneously complete the fine grinding process. In the latter implementation, after the rough grinding process is completed simultaneously on both sides, the fine grinding wheel 22 on one side performs fine grinding on the entire workpiece to be processed, thus completing the fine grinding process.

[0039] Internal thread grinding equipment can, for example, switch between different workstations via a horizontal rotary drive motor. This motor can be, for example, a servo motor or a direct drive motor; this application does not limit its application. Optionally, the dressing disc 5 may include only the rough grinding dressing disc 51, only the fine grinding dressing disc 52, or both. Optionally, the rough grinding dressing disc 51 may be two discs symmetrically arranged in opposite directions, facing the left and right sides of the rotary clamping mechanism 1. This implementation allows for fully automated dressing of all grinding wheels, further enhancing automation.

[0040] The control device can be any module with control functions, such as a PLC or any processor. This application does not limit the specific values ​​of the above calculation methods and data; those skilled in the art can set them according to their needs.

[0041] In this implementation, the operator first places the workpiece to be processed on the rotary clamping mechanism 1, which effectively clamps the workpiece and provides rotational power to it, causing it to rotate axially. Subsequently, the operator inputs commands to the control device, which, before grinding, controls the dressing disc wheel 5 to dress and grind the coarse grinding wheel 21 on the coarse grinding wheel station 41 and the fine grinding wheel 22 on the fine grinding wheel station 42 according to a preset contour. After dressing, the control device axially aligns the coarse grinding wheel station 41 with the workpiece, allowing the coarse grinding wheel 21 to perform rough grinding. After rough grinding, the control device switches the station, rotating the platform from the coarse grinding wheel station 41 to the fine grinding wheel station 42, axially aligning the fine grinding wheel station 42 with the workpiece, allowing the fine grinding wheel 22 to perform fine grinding, until the entire grinding process is complete.

[0042] The implementation method provided in this embodiment distinguishes between coarse and fine grinding wheels, thereby improving the precision of the entire dressing process and thus enhancing the grinding effect. Furthermore, by integrating the three functional modules of coarse grinding, fine grinding, and online dressing into a single enclosed machine tool, all grinding processes can be completed after a single workpiece clamping. This not only completely eliminates the auxiliary time spent on workpiece transfer, waiting, and repeated clamping and positioning between different devices, significantly shortening the single-piece processing cycle, but also enables seamless and continuous automatic operation of the entire process. The equipment can automatically select different grinding wheels according to a preset program and execute machining and dressing actions in the optimal sequence, realizing a leap from "discrete island" production to "continuous flow" production, greatly improving equipment utilization and production automation levels, and providing a hardware foundation for large-scale, flexible manufacturing.

[0043] Furthermore, a single clamping operation ensures the uniqueness of the reference for all grinding processes, fundamentally eliminating concentricity and positional errors caused by reference conversion, and ensuring high geometric accuracy of the threads. Secondly, the integrated dressing disc can perform online, in-situ high-precision profile dressing of the roughing and finishing grinding wheels based on grinding wheel wear monitoring data or fixed cycles. This real-time maintenance allows the grinding wheel to maintain optimal profile accuracy and sharpness throughout the entire machining cycle, thereby consistently producing threads with excellent surface finish, precise tooth profile, and consistent dimensions. This technology transforms the "passive, offline, experience-based management" of grinding wheel status into "active, online, data-driven management," significantly improving the capability index of the process. This results in excellent repeatability and reliability of parts in mass production, making it suitable for the stable mass production of high-precision ball screw nuts such as planetary roller ball screw nuts, and thus providing powerful support for the field of humanoid robots.

[0044] Optionally, in some embodiments, the stage 4 may also be equipped 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. The control device determines the initial working position and grinding depth of the grinding devices 2 on the left and right sides of the rotary clamping mechanism 1 according to a preset calculation method and data. This implementation method can achieve more precise positioning of the workpiece to be processed, enabling the grinding wheel to grind the workpiece more accurately and improve the grinding quality.

[0045] In one possible implementation, the calibration device 6 includes 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.

[0046] The probe 61 mentioned above can be, for example, a contact trigger probe, a contact scanning probe, or a non-contact probe, and this application does not limit its type.

[0047] For example, the control device can determine the initial working position of the grinding device 2 by detecting the position data of the reference plate 71 and the position data of the workpiece to be processed, and determine the motion trajectory of the grinding device 2 according to the preset processing data of the workpiece to be processed. For example, before the grinding device 2 grinds the workpiece to be processed, the control device can control the probe 61 to first contact the reference plate 71 to calibrate the position of the probe 61. Then the control device controls the probe 61 to contact the workpiece to be processed to determine the specific position of the workpiece to be processed. Furthermore, the control device can determine the initial working position and grinding depth of the grinding device 2, so that the grinding device 2, including the rough grinding wheel 21 and the fine grinding wheel 22, can be directly controlled to achieve precise grinding of the workpiece to be processed, thereby improving the grinding accuracy.

[0048] Optionally, in some embodiments, the platform 4 is provided with a platform drive device capable of driving the platform 4 to move in both the transverse and longitudinal directions, and the platform drive device is mounted on the platform 4. The platform 4 can, for example, be directly connected to a guide rail 8 arranged in the transverse direction, or connected via a guide rail 8 arranged in the transverse direction and a guide rail 8 arranged in the longitudinal direction; or the platform 4 can be as follows... Figure 1 The connection shown is directly connected to the guide rail 8 arranged along the longitudinal direction, or 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.

[0049] The aforementioned stage drive device can be either a servo motor or a direct drive motor, and this application does not limit it. Since the stage drive device can drive the stage 4 to move in both the transverse and longitudinal directions, the position of the stage 4 can be adjusted to control the alignment of the grinding device 2 and the workpiece to be processed during grinding, thereby improving the flexibility and availability of the equipment and further enhancing the grinding accuracy of the workpiece to be processed.

[0050] Optionally, the rotary clamping mechanism 1 may have a fine grinding wheel 22 and a coarse grinding wheel 21 on only one side, or the grinding devices 2 on both sides of the rotary clamping mechanism 1 may each include a coarse grinding wheel 21 and a fine grinding wheel 22 that can be rotated into their working positions in the horizontal direction. When both sides of the grinding device 2 include a coarse grinding wheel 21 and a fine grinding wheel 22, the equipment can simultaneously perform coarse and fine grinding on both sides of the grinding device 2, further improving grinding efficiency. Having identical grinding devices 2 and table 4 positions on both sides can improve grinding accuracy while ensuring grinding efficiency. Optionally, during simultaneous processing on both sides, co-directional processing or opposing processing can be selected. During co-directional processing, for example, one side can be processed from the end, while the other side can start processing from the middle of the workpiece.

[0051] Optionally, the platforms 4 on both sides of the rotary clamping mechanism 1 may each be equipped with a rough grinding wheel station 41 and a fine grinding wheel station 42, which can be respectively moved into working positions by rotating in the horizontal direction. This implementation method can realize automatic switching between different stations on both sides, and can perform grinding of the workpiece to be processed simultaneously in both directions, thereby improving grinding efficiency.

[0052] Optionally, the stage 4 may be equipped with a horizontal rotation drive device that can rotate in the horizontal direction. The horizontal rotation drive device may include, for example, a drive motor, such as a servo motor or a direct drive motor.

[0053] Optionally, the workstations on the same platform 4 can be at any angle, and this application does not limit them. Optionally, in some embodiments, the workstations on the same platform 4 can be perpendicular to each other. This implementation can, to a certain extent, ensure sufficient working space between adjacent workstations and avoid mutual interference.

[0054] 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 three-threaded design, one side having a coarse grinding wheel 21 and a fine grinding wheel 22 with corresponding coarse grinding dressing disc wheel 51 and a fine grinding dressing disc wheel 52, and the other side having a coarse grinding wheel 21 with a corresponding 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:

[0055] 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.

[0056] 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.

[0057] 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.

[0058] (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;

[0059] (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;

[0060] (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.

[0061] (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;

[0062] (5) Grinding is complete.

[0063] 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.

[0064] Note 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention 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.

[0078] 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. An internal thread grinding device, comprising a rotary clamping mechanism disposed on a worktable, and grinding devices that move laterally and longitudinally respectively disposed on the left and right sides of the rotary clamping 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 movement. The platform stations are switched by rotating the platform in the horizontal direction. The platform stations include a rough grinding wheel station and a fine grinding wheel station. At least one side of the rotary clamping mechanism is also provided with a dressing disc wheel for dressing the grinding device. The device also includes a control device connected to the rotary clamping mechanism, the grinding device, and the dressing disc wheel. The control device controls the transverse feed and longitudinal feed of the grinding device and the rotational speed of the rotary clamping mechanism according to a preset calculation method and data. Before grinding, the control device controls the dressing disc wheel to dress and grind the rough grinding wheel on the rough grinding wheel station and the fine grinding wheel on the fine grinding wheel station according to a preset profile. The platform also includes a calibration station. The calibration station is equipped with a calibration device for determining the initial working position of the workpiece to be processed. The control device determines the initial working position and grinding depth of the grinding device on the left and right sides of the rotary clamping mechanism according to a preset calculation method and data. The calibration device includes a probe for detecting the position of the workpiece to be processed. A reference plate for calibrating the reference position is also provided on one side of the rotary clamping mechanism. The control device determines the initial working position of the grinding device by detecting the position of the reference plate and the position data of the workpiece to be processed. According to the preset processing data of the workpiece to be processed, the control device determines the motion trajectory of the grinding device. The control device calculates the shape of the grinding wheel through an algorithm, and then controls the grinding wheel to move along the X-axis and Z-axis to realize the interpolation dressing of the grinding wheel based on the dressing disc wheel, and dresses the profile of the grinding wheel.

2. The internal thread grinding equipment as described in claim 1, characterized in that, The dressing disc wheel includes a fine grinding dressing disc wheel and a coarse grinding dressing disc wheel, wherein the coarse grinding dressing disc wheel consists of two grinding devices arranged in opposite directions and symmetrically facing the left and right sides of the rotating clamping mechanism.

3. The internal thread grinding equipment as described in claim 1, characterized in that, The platform is provided with a platform driving device for driving the platform to move in the lateral and longitudinal directions, and the platform driving device is mounted on the platform; the platform is connected to a guide rail arranged in the lateral direction, and is also connected to a guide rail arranged in the longitudinal direction through the lateral direction 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 lateral direction through the longitudinal direction guide rail.

4. The internal thread grinding equipment as described in claim 1, characterized in that, The grinding devices arranged on both sides of the rotary clamping mechanism each include a coarse grinding wheel and a fine grinding wheel that enter the working position by rotating in the horizontal direction.

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, The platforms on both sides of the rotary clamping mechanism are each equipped with a coarse grinding wheel station and a fine grinding wheel station, which respectively enter the working position by rotating in the horizontal direction.

7. 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.

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