A movable center mechanism of a gear shaping machine and an adjusting method

Abstract

The application provides a shaped gear grinding machine movable center mechanism and adjustment method, and belongs to the positioning technical field of gear grinding machines. The mechanism comprises an axially movable center seat, an upper end cover with a positioning spherical surface arranged at the upper end of the center seat, and a guide sleeve with a positioning inner conical surface arranged at the lower end of the center seat; a floating shaft sleeve assembly is arranged in the installation through hole, the lower end conical surface of the conical surface fine adjustment cover is provided with a positioning outer conical surface matched with the positioning inner conical surface; a floating conical sleeve is arranged in the floating shaft sleeve, the upper end of the floating conical sleeve is provided with a centering ball head matched with the positioning spherical surface, and a center is arranged at the lower end of the floating conical sleeve; an upper elastic member and a lower elastic member with different rigidities are arranged above and below respectively, and the rigidity of the lower elastic member is greater than that of the upper elastic member; the conical surface fine adjustment cover is provided with a radial adjustment assembly. The conical surface cooperation is used to replace the steel ball retainer, the spherical surface centering cooperation is used to replace the locking screw friction, the double-spring differential rigidity is used to realize step positioning, the structure is simple, the cost is low, the positioning precision is high, the rigidity is good, the service life is long, and the mechanism is suitable for high-precision positioning of workpieces of various shaped gear grinding machines.

Description

Technical Field

[0001] This invention belongs to the field of gear grinding machine technology, and in particular relates to a moving tip mechanism and adjustment method for a forming gear grinding machine. Background Technology

[0002] Gear grinding machines are the core equipment in the gear finishing process, and their machining accuracy directly determines the transmission smoothness, load-bearing capacity, and service life of the gears. The center, as the core functional component in the tailstock system of the gear grinding machine for positioning and supporting the workpiece, has a decisive influence on the final grinding accuracy, especially in the machining of slender shaft gears and high-precision gears.

[0003] In existing technologies, gear grinding machine centers are mainly divided into two categories: integral fixed centers and ordinary rotary centers. Integral fixed centers have good rigidity, but the center head and the workpiece center hole are subject to sliding friction. After long-term use, the center head is prone to wear, resulting in decreased positioning accuracy, and the overall replacement cost is high. Ordinary rotary centers can rotate synchronously with the workpiece, with less friction and wear, but the internal bearing assembly is easily contaminated by grinding fluid and grinding debris, causing problems such as rotational jamming and excessive runout, and requiring frequent maintenance. In addition, existing center mechanisms generally suffer from insufficient clamping rigidity, poor coaxiality retention, and inconvenient radial adjustment under high-speed, heavy-load grinding conditions, making it difficult to meet the comprehensive requirements of high-precision gear machining for high rigidity, high precision, and long service life of the center system.

[0004] Chinese patent document CN102601561A discloses a movable center mechanism for a gear grinding machine, which achieves the floating and positioning of the center sleeve through a steel ball and cage structure. This structure has the following significant drawbacks: First, the machining precision and consistency requirements for the steel balls and cage are extremely high, making precise control of the mating clearance difficult, resulting in high manufacturing costs. Furthermore, the steel balls are prone to wear after long-term use, leading to increased clearance and decreased positioning accuracy. Second, when adjusting the radial position of the center, the set screw and the center positioning sleeve engage in rigid sliding friction, easily causing scratches and wear on the mating surfaces, affecting positioning accuracy and service life. Therefore, the existing technology cannot simultaneously address machining costs, positioning accuracy, structural rigidity, and service life, necessitating a novel movable center mechanism to solve these problems. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a movable center mechanism and adjustment method for a forming gear grinding machine. It replaces the steel ball retainer structure with a conical surface fit, replaces the rigid friction of the set screw with a spherical centering fit for radial fine adjustment, and achieves step-by-step positioning through a double spring differential stiffness design. This significantly improves the positioning accuracy, structural rigidity, and service life of the center while reducing manufacturing costs.

[0006] To achieve the above-mentioned technical features, the present invention aims to provide a movable center mechanism for a gear grinding machine, comprising a center seat axially movably mounted on the gear grinding machine, and a center for workpiece positioning, further comprising: The upper end cover is fixedly installed at the upper end of the axial mounting through hole of the center seat, and the lower end face of the upper end cover is provided with a concave positioning spherical surface. A guide sleeve is fixedly installed at the lower end of the mounting through hole, and the inner hole of the guide sleeve is provided with a positioning inner conical surface; A floating bushing assembly is coaxially inserted into a mounting through hole and can float axially. The floating bushing assembly includes a bushing body, a bushing cover fixed to the upper end of the bushing body, and a conical fine-tuning cover fixed to the lower end of the bushing body. The outer periphery of the conical fine-tuning cover is provided with a positioning outer conical surface that is adapted to the positioning inner conical surface. An upper elastic element is disposed between the upper end cover and the bushing cover, and is used to apply an elastic preload force toward the workpiece direction to the floating bushing assembly; A floating cone sleeve is coaxially inserted into a floating bushing assembly and can float axially. The upper end of the floating cone sleeve is provided with a centering ball head that is adapted to the positioning spherical surface, and the lower end is provided with a mounting cone hole for mounting a center point. The lower elastic element is located between the bushing cover and the floating cone sleeve, and is used to apply an elastic preload force toward the workpiece to the floating cone sleeve; the stiffness of the lower elastic element is greater than that of the upper elastic element. A radial adjustment assembly, located on the conical fine-tuning cover, is used to tighten and adjust the radial position of the floating conical sleeve along the radial direction.

[0007] Preferably, the guide sleeve and the center seat are in an adjustable fixed connection; the guide sleeve can be finely adjusted in the radial direction, and after being adjusted to a preset coaxiality, it is locked and fixed to the center seat by fasteners; The radial adjustment assembly includes at least two adjusting screws evenly arranged circumferentially; the adjusting screws are radially inserted through the side wall of the conical fine-tuning cover, and their inner ends abut against the outer circumferential surface of the floating conical sleeve.

[0008] Preferably, the positioning inner conical surface is located at the lower end of the inner hole of the guide sleeve, and its diameter gradually increases in the direction toward the workpiece; the positioning outer conical surface is located at the upper end of the outer periphery of the conical fine-tuning cover, and its diameter gradually increases in the direction toward the workpiece; when the floating bushing assembly moves away from the workpiece relative to the guide sleeve, the positioning inner conical surface and the positioning outer conical surface form a conical fit, thereby achieving radial centering.

[0009] Preferably, a lower end cover is fixedly connected to the lower end of the guide sleeve, and the lower end cover is sleeved on the outside of the conical fine-tuning cover; a first sealing element is provided between the mating surfaces of the conical fine-tuning cover and the lower end cover; A second sealing element is provided between the connecting end face of the upper end cover and the center seat.

[0010] Preferably, the mounting cone hole is a Morse taper hole; the tip is installed in the Morse taper hole through a self-locking fit of the taper surface; the outer periphery of the tip is provided with a disassembly nut for disassembling the tip.

[0011] Preferably, the upper elastic element is an upper helical compression spring, coaxially sleeved on the outside of the bushing body; the lower elastic element is a lower helical compression spring, coaxially sleeved on the outside of the floating cone sleeve. The bushing cover is a split ring structure, which is fixedly connected to the upper end face of the bushing body by fastening screws.

[0012] Preferably, a second aspect of the present invention provides a method for adjusting the movable center mechanism of a forming gear grinding machine, based on the aforementioned movable center mechanism, comprising the following steps: S1. Pre-installation and debugging: Pre-install the guide sleeve at the lower end of the mounting through hole of the center seat, finely adjust the radial position of the guide sleeve to the preset coaxiality and then lock it in place; install the floating bushing assembly, upper elastic element, floating cone sleeve and lower elastic element into the mounting through hole in sequence, install the upper end cover and lock it in place; install the center into the mounting cone hole at the lower end of the floating cone sleeve. S2, Bushing conical surface positioning: Drive the center seat to move towards the workpiece, and stop moving after the center contacts the end face of the workpiece; The center seat continues to move towards the workpiece, the upper elastic element is compressed, and the guide sleeve moves synchronously with the center seat, so that the positioning inner conical surface of the guide sleeve and the positioning outer conical surface of the conical fine adjustment cover gradually fit together, completing the radial positioning of the floating bushing assembly. S3. Conical sleeve spherical centering: The center seat continues to move towards the workpiece, and the floating sleeve assembly moves synchronously with the center seat. The lower elastic element is compressed, so that the centering ball head at the upper end of the floating cone sleeve fits into the positioning ball surface of the upper end cover, thus completing the automatic centering of the upper end of the floating cone sleeve. S4. Radial fine-tuning and locking: Adjust the radial adjustment component to tighten the outer circumference of the floating cone sleeve, fine-tune the radial position of the floating cone sleeve to the preset accuracy, and then lock it to complete the precise positioning of the tip.

[0013] Preferably, in step S1, the radial fine-tuning of the guide sleeve is specifically as follows: the guide sleeve is placed in the mounting stop at the lower end of the center seat, the radial runout of the inner hole of the guide sleeve is detected by a dial indicator, the position of the guide sleeve is adjusted by tapping along the radial direction until the runout meets the accuracy requirements, and then the guide sleeve is locked to the center seat by the circumferentially arranged fastening screws.

[0014] Preferably, in step S2, since the stiffness of the lower elastic element is greater than that of the upper elastic element, after the tip contacts the workpiece, the upper elastic element undergoes compression deformation before the lower elastic element, ensuring that the inner positioning cone surface and the outer positioning cone surface complete the fitting and positioning first.

[0015] Preferably, in step S4, the radial adjustment assembly includes multiple circumferentially evenly distributed adjustment screws; by alternately screwing in or out each adjustment screw, the radial offset and axial deflection of the floating cone sleeve are adjusted, and after adjustment, each adjustment screw is locked. It also includes the tip removal step: rotate the removal nut on the tip so that the end face of the removal nut abuts against the lower end face of the conical fine adjustment cover, and continue to rotate the nut to push the tip out of the mounting conical hole, thus completing the removal and replacement of the tip.

[0016] The present invention has the following beneficial effects: 1. This invention adopts a mating structure of the inner conical surface of the guide sleeve and the outer conical surface of the conical fine-tuning cover, replacing the traditional steel ball and cage structure, which greatly reduces the requirements for part machining accuracy and assembly difficulty, and effectively controls manufacturing costs; at the same time, the conical surface has a large contact area, strong load-bearing capacity, and significantly better positioning rigidity than the steel ball point contact structure, making it more suitable for heavy-duty grinding conditions.

[0017] 2. This invention adopts a tapered sleeve positioning scheme with an upper spherical pair for automatic centering and a lower set screw for fine-tuning and locking. This avoids the rigid sliding friction between the traditional set screw and the tapered sleeve, and eliminates the impact of scratches and wear on the mating surface on the positioning accuracy. Combined with the tapered sleeve positioning structure, it achieves double centering, and significantly improves the repeatability and long-term accuracy of the top.

[0018] 3. This invention uses upper and lower double springs with different stiffnesses to achieve a step-by-step positioning action of "first positioning on the conical surface of the bushing, then centering on the spherical surface of the conical bushing" by utilizing the stiffness difference. The positioning sequence is stable and controllable, avoiding over-positioning interference caused by multiple positioning surfaces fitting at the same time, and ensuring the consistency of positioning accuracy.

[0019] 4. The present invention has a sealing structure at both the upper and lower connecting surfaces and the mating surfaces, which can effectively prevent contaminants such as grinding debris and cutting fluid from entering the interior of the mechanism, avoid contamination and wear of the internal mating surfaces, and greatly extend the maintenance cycle and service life of the mechanism.

[0020] 5. This invention adopts a split modular structure, which is convenient for assembly and disassembly. The tip adopts a standard Morse taper hole for installation, which is convenient for replacement. It can be adapted to various specifications of tips and is suitable for different models of forming gear grinding machines, with strong versatility. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Figure 1 This is a cross-sectional view of the movable tip mechanism of the forming gear grinding machine in the free state according to Embodiment 1 of the present invention.

[0023] Figure 2This is a cross-sectional view of the movable center mechanism of the forming gear grinding machine in the state of clamping the workpiece, as described in Embodiment 1 of the present invention.

[0024] In the diagram: 1-Upper end cover, 2-Positioning spherical surface, 3-Upper elastic element, 4-Top seat, 5-Sleeve cover, 6-Lower elastic element, 7-Sleeve body, 8-Floating cone sleeve, 9-Top, 10-Guide sleeve, 11-Positioning inner cone surface, 12-Lower end cover, 13-Cone surface fine-tuning cover, 14-Radial adjustment assembly, 15-Removal nut, 16-First seal, 17-Second seal. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0026] Example 1: Top-level organization for basic activities like Figure 1 , Figure 2 As shown, this embodiment provides a movable center mechanism for a forming gear grinding machine, which is a basic implementation method. It includes a center seat 4, an upper end cover 1, a guide sleeve 10, a floating bushing assembly, an upper elastic element 3, a floating cone sleeve 8, a lower elastic element 6, and a radial adjustment assembly 14.

[0027] The center seat 4 is a cylindrical structure with a through-hole running axially through its center. The center seat 4 can be slidably mounted axially on the tailstock guide rail of the gear grinding machine, and is driven by the machine tool drive mechanism to achieve axial feed. The upper end cover 1 is a circular end cover, fixed to the upper opening of the through-hole by multiple hexagonal socket screws. The lower end face of the upper end cover 1 has a concave spherical surface machined at its center, i.e., the positioning spherical surface 2. The guide sleeve 10 is an annular sleeve structure, located at the lower opening of the through-hole. The lower section of the inner hole of the guide sleeve 10 has a tapered surface machined, i.e., the positioning inner tapered surface 11. The diameter of the positioning inner tapered surface 11 gradually increases downwards, with a taper of 1:5.

[0028] The floating bushing assembly is coaxially inserted into the mounting through hole and can float freely along the axial direction. The floating bushing assembly includes a bushing body 7, a bushing cover 5, and a conical fine-tuning cover 13. The bushing body 7 is a cylindrical structure, and the bushing cover 5 is a split annular end cover, fixed to the upper end face of the bushing body 7 by four circumferentially evenly arranged screws. The conical fine-tuning cover 13 is an annular structure, fixed to the lower end face of the bushing body 7 by screws; the upper part of the outer circumferential surface of the conical fine-tuning cover 13 has an outer conical surface machined, i.e., a positioning outer conical surface, whose taper matches the positioning inner conical surface 11, also at a ratio of 1:5, with the diameter gradually increasing downwards. When the floating bushing assembly moves upwards relative to the guide sleeve 10, the positioning inner conical surface 11 and the positioning outer conical surface can completely fit together, achieving radial automatic centering.

[0029] The upper elastic element 3 is a cylindrical helical compression spring, which is coaxially sleeved on the outside of the bushing body 7. Its upper end abuts against the lower end face of the upper end cover 1, and its lower end abuts against the upper end face of the bushing cover 5. It is always in a compressed state, providing downward preload for the floating bushing assembly.

[0030] The floating cone sleeve 8 is coaxially inserted into the inner hole of the floating bushing assembly and can float freely along the axial direction. The upper end of the floating cone sleeve 8 has an integrally formed outwardly protruding spherical head, i.e., a centering ball head. The radius of the centering ball head matches the radius of the positioning ball surface 2; when they are in contact, they form a spherical pair, achieving automatic centering. The lower end of the floating cone sleeve 8 has a Morse taper hole as an installation taper hole, and the tip 9 is installed in this taper hole through a self-locking fit. The outer circumference of the tip 9's shank is machined with external threads, and a disassembly nut 15 is installed to disassemble the tip.

[0031] The lower elastic element 6 also uses a cylindrical helical compression spring, coaxially sleeved on the outside of the floating cone sleeve 8. Its upper end abuts against the lower end face of the bushing cover 5, and its lower end abuts against the stepped end face in the middle of the floating cone sleeve 8. It is always in a compressed state, providing downward preload to the floating cone sleeve 8. In this embodiment, the spring stiffness of the lower elastic element 6 is 2.5 times that of the upper elastic element 3, ensuring that the upper elastic element 3 undergoes compression deformation first during the pressing process.

[0032] The radial adjustment assembly 14 includes two adjusting screws arranged radially opposite each other. The adjusting screws are inserted into the threaded holes on the side wall of the conical fine-tuning cover 13, and their inner ends can abut against the outer circumferential surface of the floating cone sleeve 8. The radial position of the floating cone sleeve 8 can be finely adjusted by rotating the adjusting screws.

[0033] The working process and adjustment method of this embodiment are as follows: Pre-assembly and debugging: Place the guide sleeve 10 into the mounting stop at the lower end of the center seat 4. Use a dial indicator to check the radial runout of the inner hole of the guide sleeve 10. Gently tap the outer wall of the guide sleeve 10 with a copper rod to fine-tune its position until the runout is ≤0.002mm. Then tighten the 6 circumferential fastening screws to lock the guide sleeve 10 and the center seat 4 in place. Assemble the conical fine-tuning cover 13, the bushing body 7, and the bushing cover 5 into a floating bushing assembly in sequence. After putting on the upper elastic element 3, insert it into the mounting through hole. Then put the lower elastic element 6 on the floating conical sleeve 8 and insert it into the bushing body together. Finally, install the upper end cover 1 and lock it to complete the pre-assembly of the mechanism. Insert the center 9 into the Morse taper hole of the floating conical sleeve 8 and tap it to lock it.

[0034] Bushing conical surface positioning: The machine tool drives the center seat 4 to move downwards, and the tip of the center 9 stops moving downwards after contacting the center hole of the workpiece. The center seat 4 continues to feed downwards. Due to the high rigidity of the lower elastic element 6, both the floating conical sleeve 8 and the floating bushing assembly remain stationary, while the upper elastic element 3 is gradually compressed. The guide sleeve 10 moves downwards synchronously with the center seat 4, and the positioning inner conical surface 11 of its inner hole gradually approaches the positioning outer conical surface of the conical fine-tuning cover 13 until they are completely fitted, completing the radial positioning of the floating bushing assembly.

[0035] Conical sleeve spherical centering: The center seat 4 continues to feed downwards, and the friction generated by the conical surface contact drives the floating sleeve assembly to move downwards synchronously; at this time, the floating conical sleeve 8 remains stationary, the lower elastic element 6 is gradually compressed, and the centering ball head at the upper end of the floating conical sleeve 8 gradually approaches the positioning ball surface 2 of the upper end cover 1 until they are tightly fitted, thus completing the automatic centering of the upper end of the floating conical sleeve 8.

[0036] Radial fine-tuning and locking: Use a dial indicator to check the radial runout of the center 9, rotate the two adjusting screws respectively to fine-tune the radial position of the floating cone sleeve 8 until the runout of the center meets the machining accuracy requirements, and then tighten the adjusting screws to complete the final positioning of the center.

[0037] After processing, the center seat 4 retracts upwards, and the upper elastic element 3 and the lower elastic element 6 spring back in sequence, restoring the mechanism to its original position. Figure 1 The free state is shown. When the tip 9 needs to be replaced, rotate the disassembly nut 15 so that its upper end face abuts against the lower end face of the conical fine adjustment cover 13, and continue to rotate to push the tip 9 out of the Morse taper hole.

[0038] Example 2: Heavy-duty movable center mechanism with sealed protection This embodiment provides a movable center mechanism for a forming gear grinding machine, which is an optimized solution based on Embodiment 1. The main improvement is the addition of a sealing and protective structure, making it suitable for heavy-duty grinding scenarios with a large amount of grinding debris and cutting fluid spray.

[0039] In this embodiment, the lower end of the guide sleeve 10 is fixedly connected to a lower end cover 12 by screws. The lower end cover 12 is an annular end cover, which is fitted onto the outside of the conical fine-tuning cover 13. The inner hole of the lower end cover 12 and the outer periphery of the conical fine-tuning cover 13 are in clearance fit. The outer periphery of the conical fine-tuning cover 13 is machined with an annular sealing groove, and a first sealing element 16, specifically a nitrile rubber O-ring, is installed in the groove. The outer periphery of the first sealing element 16 is tightly fitted with the inner wall of the lower end cover 12 to form a radial seal, which can effectively prevent grinding debris and cutting fluid from entering the interior of the conical mating surface from the lower end.

[0040] Meanwhile, a second sealing element 17 is provided between the connecting end face of the upper end cover 1 and the top seat 4, specifically an end face sealing gasket. A sealing groove is machined on the lower end face of the upper end cover 1, and the second sealing element 17 is embedded in the sealing groove. After the upper end cover 1 is locked, the second sealing element 17 is pressed against the upper end face of the top seat 4 to form an end face seal, preventing contaminants from entering the installation through hole from the top.

[0041] In addition, in this embodiment, the taper of the inner positioning cone 11 and the outer positioning cone is optimized to 1:7, which increases the contact area of ​​the cone surfaces and further improves the positioning rigidity and load-bearing capacity; the stiffness of the lower elastic member 6 is adjusted to 3 times that of the upper elastic member 3, so that the cone surfaces fit more tightly and have stronger impact resistance.

[0042] The remaining structure and working principle of this embodiment are the same as those of Embodiment 1. By adding a double sealing structure, the protection level of the mechanism is significantly improved, and it can operate stably for a long time under harsh grinding conditions, extending the maintenance cycle by more than 40%.

[0043] Example 3: High-precision movable center mechanism with four-point adjustment This embodiment provides a movable center mechanism for a forming gear grinding machine, which is a high-precision optimization scheme based on Embodiment 2. The main improvement is in the radial adjustment component 14, which is suitable for high-precision gear processing scenarios with a precision level of 5 or higher.

[0044] In this embodiment, the radial adjustment assembly 14 includes four adjusting screws evenly distributed circumferentially, with the included angle between two adjacent adjusting screws being 90°, corresponding to the X and Y orthogonal directions respectively. The inner end of each adjusting screw is machined into a spherical end to reduce contact friction with the outer periphery of the floating cone sleeve 8 and avoid scratching the mating surface; four threaded holes are correspondingly machined on the side wall of the cone fine-tuning cover 13, and the adjusting screws are engaged with the threaded holes, with a rotation accuracy of 0.001 mm / turn.

[0045] Meanwhile, in this embodiment, the spherical accuracy of the positioning spherical surface 2 and the centering ball head is improved to G2 level, and the contact surface tolerance of the positioning inner conical surface 11 and the positioning outer conical surface is controlled within 0.001mm; the pre-assembly coaxiality requirement of the guide sleeve 10 is improved to ≤0.001mm. The outer circular surface of the floating cone sleeve 8 and the inner hole of the bushing body 7 adopt a small clearance fit, with a fit clearance of 0.005~0.008mm, which ensures smooth floating and restricts radial movement.

[0046] In the adjustment method of this embodiment, the radial fine-tuning step adopts the orthogonal adjustment method: first, adjust the two set screws in the X direction to adjust the X-direction runout of the center 9 to the tolerance range, then adjust the two set screws in the Y direction to adjust the Y-direction runout, and repeatedly fine-tune until the radial runout of the center is ≤0.001mm, and finally tighten all four set screws.

[0047] The remaining structure and working principle of this embodiment are the same as those of embodiment 2. By using a four-point orthogonal adjustment structure and a high-precision mating surface, the final positioning accuracy of the center 9 is improved by more than double, which can meet the grinding requirements of ultra-high precision gears.

[0048] Example 4: CNC Automatic Adjustment Movable Center Mechanism This embodiment provides a movable center mechanism and automatic adjustment method for a forming gear grinding machine. It is an automated upgrade scheme based on Embodiment 3 and is applied to a CNC forming gear grinding machine, which can realize the automated adjustment of the center 9 positioning.

[0049] In this embodiment, the center seat 4 is driven by a servo motor through a ball screw mechanism, which can precisely control the axial feed displacement; the radial adjustment component 14 is replaced by four sets of piezoelectric ceramic fine-tuning actuators, replacing the manual adjustment of the set screw, which can achieve nanometer-level radial position fine-tuning. The mechanism integrates a displacement sensor for real-time detection of the axial displacement of the floating bushing assembly and the floating cone sleeve 8.

[0050] The automatic adjustment method in this embodiment is as follows: S1. System initialization: The machine tool control system starts, the servo motor drives the center seat 4 back to the origin position, and the mechanism is in a free state; the piezoelectric ceramic fine-tuning actuator is reset to the neutral position.

[0051] S2. Workpiece clamping: Hoist the gear workpiece onto the worktable of the gear grinding machine, aligning the center holes at both ends with the center point 9 of the head and tailstock.

[0052] S3. Automatic clamping and positioning: The control system issues a feed command, and the servo motor drives the center seat 4 to move towards the workpiece at a rapid traverse speed. When the displacement sensor detects that the center 9 is in contact with the workpiece and the displacement changes abruptly, the feed speed is switched to working speed. The center seat 4 continues to feed, and the control system monitors the compression of the upper elastic element 3 in real time through the displacement sensor. When the compression reaches the preset value and the conical surface is fully engaged and positioned, the bushing positioning is determined to be complete.

[0053] S4. Automatic centering and fine adjustment: The center seat 4 continues to advance, monitoring the compression of the lower elastic element 6. After reaching the preset micro-compression value, it is determined that the spherical bonding and centering is completed. The control system automatically controls the action of 4 sets of piezoelectric ceramic actuators according to the built-in center runout calibration parameters, finely adjusts the radial position of the floating cone sleeve 8, and automatically completes the center precision calibration.

[0054] S5. Locking process: After calibration, the piezoelectric ceramic actuator maintains the locking force, the mechanism enters the processing state, and the gear grinding process begins.

[0055] The remaining mechanical structure of this embodiment is basically the same as that of embodiment 3. By introducing servo drive and piezoelectric fine-tuning elements, the full automation of the top 9 positioning adjustment is realized, which greatly improves the automation level and adjustment efficiency of the machine tool and is suitable for large-volume, multi-variety gear automated production lines.

[0056] Example 5: This embodiment provides a method for adjusting the movable center mechanism of a forming gear grinding machine, based on the movable center mechanism of the forming gear grinding machine in Embodiment 1, and includes the following steps: S1. Pre-installation and debugging: Pre-install the guide sleeve 10 in the lower end stop of the mounting through hole of the center seat 4, finely adjust the radial position of the guide sleeve 10 to the preset coaxiality and then lock it in place; install the floating bushing assembly, the upper elastic element 3, the floating cone sleeve 8 and the lower elastic element 6 into the mounting through hole in sequence, install the upper end cover 1 and lock it in place; install the center 9 into the mounting cone hole at the lower end of the floating cone sleeve 8 to complete the pre-installation.

[0057] S2. Bushing conical surface positioning: Drive the center seat 4 to move towards the workpiece. After the front end of the center 9 contacts the end face of the center hole of the workpiece, it stops moving. The center seat 4 continues to move towards the workpiece, the upper elastic element 3 is compressed, and the guide sleeve 10 moves towards the workpiece synchronously with the center seat 4, so that the positioning inner conical surface 11 of the guide sleeve 10 and the positioning outer conical surface of the conical fine adjustment cover 13 gradually fit together, thus completing the radial precise positioning of the floating bushing assembly.

[0058] S3. Conical sleeve spherical centering: The center seat 4 continues to move towards the workpiece. The floating bushing assembly moves synchronously with the center seat 4 under the action of the conical friction force. The lower elastic element 6 is compressed, so that the centering ball head at the upper end of the floating cone sleeve 8 is tightly fitted with the positioning ball surface 2 of the upper end cover 1, thus completing the automatic centering of the upper end of the floating cone sleeve 8.

[0059] S4. Radial fine-tuning and locking: Adjust the radial adjustment component 14 to tighten the outer periphery of the floating cone sleeve 8, fine-tune the radial position of the floating cone sleeve 8 to the preset accuracy, and then lock it to finally complete the precise positioning and rigid fixation of the tip 9.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A movable center mechanism for a gear grinding machine, comprising a center seat (4) axially movably mounted on the gear grinding machine, and a center (9) for workpiece positioning, characterized in that, Also includes: The upper end cover (1) is fixedly installed on the upper end of the axial mounting through hole of the top seat (4), and the lower end face of the upper end cover (1) is provided with a concave positioning spherical surface (2). The guide sleeve (10) is fixedly installed at the lower end of the mounting through hole, and the inner hole of the guide sleeve (10) is provided with a positioning inner cone surface (11). The floating bushing assembly is coaxially inserted into the mounting through hole and can float along the axial direction. The floating bushing assembly includes a bushing body (7), a bushing cover (5) fixed to the upper end of the bushing body (7), and a conical fine-tuning cover (13) fixed to the lower end of the bushing body (7). The outer periphery of the conical fine-tuning cover (13) is provided with a positioning outer conical surface that is adapted to the positioning inner conical surface (11). The upper elastic element (3) is disposed between the upper end cover (1) and the bushing cover (5) for applying an elastic preload force toward the workpiece direction to the floating bushing assembly; The floating cone sleeve (8) is coaxially inserted into the floating bushing assembly and can float along the axial direction. The upper end of the floating cone sleeve (8) is provided with a centering ball head that is adapted to the positioning spherical surface (2), and the lower end is provided with a mounting cone hole for installing the center point (9). The lower elastic element (6) is disposed between the bushing cover (5) and the floating cone sleeve (8) and is used to apply an elastic preload force toward the workpiece direction to the floating cone sleeve (8); the stiffness of the lower elastic element (6) is greater than that of the upper elastic element (3); A radial adjustment assembly (14) is provided on the conical fine-tuning cover (13) for radially tightening and adjusting the radial position of the floating conical sleeve (8).

2. The movable center mechanism of a forming gear grinding machine according to claim 1, characterized in that: The guide sleeve (10) and the center seat (4) are in an adjustable fixed connection; the guide sleeve (10) can be radially finely adjusted to a preset coaxiality and then locked and fixed to the center seat (4) by fasteners; The radial adjustment assembly (14) includes at least two adjusting screws evenly arranged in the circumferential direction; the adjusting screws are radially inserted through the side wall of the conical fine-tuning cover (13), and their inner ends abut against the outer circumferential surface of the floating conical sleeve (8).

3. The movable center mechanism of the forming gear grinding machine according to claim 1, characterized in that, The positioning inner cone surface (11) is located at the lower end of the inner hole of the guide sleeve (10), and its diameter gradually increases in the direction toward the workpiece; the positioning outer cone surface is located at the upper end of the outer periphery of the cone surface fine adjustment cover (13), and its diameter gradually increases in the direction toward the workpiece; when the floating bushing assembly moves away from the workpiece relative to the guide sleeve (10), the positioning inner cone surface (11) and the positioning outer cone surface form a cone surface fit, thereby achieving radial centering.

4. The movable center mechanism of the forming gear grinding machine according to claim 1, characterized in that, The lower end of the guide sleeve (10) is fixedly connected to a lower end cover (12), which is sleeved on the outside of the conical fine adjustment cover (13); a first sealing element (16) is provided between the mating surfaces of the conical fine adjustment cover (13) and the lower end cover (12). A second sealing element (17) is provided between the connecting end face of the upper end cover (1) and the top seat (4).

5. The movable center mechanism of the forming gear grinding machine according to claim 1, characterized in that, The mounting cone hole is a Morse taper hole; the tip (9) is installed in the Morse taper hole through a self-locking fit of the taper surface; the outer periphery of the tip (9) is provided with a disassembly nut (15) for disassembling the tip.

6. The movable center mechanism of the forming gear grinding machine according to claim 1, characterized in that, The upper elastic element (3) is an upper helical compression spring, which is coaxially sleeved on the outside of the bushing body (7); the lower elastic element (6) is a lower helical compression spring, which is coaxially sleeved on the outside of the floating cone sleeve (8). The bushing cover (5) is a split ring structure, which is fixedly connected to the upper end face of the bushing body (7) by fastening screws.

7. A method for adjusting the movable center mechanism of a forming gear grinding machine, characterized in that, The method based on the movable center mechanism of the forming gear grinding machine according to any one of claims 1-6 includes the following steps: S1. Pre-installation and debugging: Pre-install the guide sleeve (10) at the lower end of the mounting through hole of the center seat (4), finely adjust the radial position of the guide sleeve (10) to the preset coaxiality and then lock it in place; install the floating bushing assembly, the upper elastic element (3), the floating cone sleeve (8) and the lower elastic element (6) into the mounting through hole in sequence, install the upper end cover (1) and lock it in place; install the center (9) into the mounting cone hole at the lower end of the floating cone sleeve (8); S2, Bushing conical surface positioning: Drive the center seat (4) to move towards the workpiece, and the center (9) stops moving after contacting the end face of the workpiece; The center seat (4) continues to move towards the workpiece, the upper elastic element (3) is compressed, and the guide sleeve (10) moves synchronously with the center seat (4), so that the positioning inner conical surface (11) of the guide sleeve (10) and the positioning outer conical surface of the conical fine adjustment cover (13) gradually fit together, thus completing the radial positioning of the floating bushing assembly; S3, Conical sleeve spherical centering: The center seat (4) continues to move towards the workpiece, and the floating sleeve assembly moves synchronously with the center seat (4). The lower elastic element (6) is compressed, so that the centering ball head at the upper end of the floating cone sleeve (8) fits with the positioning ball surface (2) of the upper end cover (1), thus completing the automatic centering of the upper end of the floating cone sleeve (8). S4. Radial fine-tuning and locking: Adjust the radial adjustment component (14) to tighten the outer periphery of the floating cone sleeve (8), fine-tune the radial position of the floating cone sleeve (8) to the preset accuracy and then lock it to complete the precise positioning of the tip (9).

8. The adjustment method according to claim 7, characterized in that, In step S1, the radial fine adjustment of the guide sleeve (10) is as follows: place the guide sleeve (10) in the mounting stop at the lower end of the center seat (4), use a dial indicator to detect the radial runout of the inner hole of the guide sleeve (10), tap along the radial direction to adjust the position of the guide sleeve (10) until the runout meets the accuracy requirements, and then lock the guide sleeve (10) and the center seat (4) with the circumferentially arranged fastening screws.

9. The adjustment method according to claim 7, characterized in that, In step S2, since the stiffness of the lower elastic element (6) is greater than that of the upper elastic element (3), after the tip (9) contacts the workpiece, the upper elastic element (3) undergoes compression deformation before the lower elastic element (6), ensuring that the inner cone surface (11) and the outer cone surface of the positioning are fitted and positioned first.

10. The adjustment method according to claim 10, characterized in that, In step S4, the radial adjustment assembly (14) includes multiple circumferentially evenly distributed adjustment screws; by alternately screwing in or out each adjustment screw, the radial offset and axial deflection of the floating cone sleeve (8) are adjusted, and after the adjustment is completed, each adjustment screw is locked. It also includes the tip removal step: rotate the removal nut (15) on the tip (9) so that the end face of the removal nut (15) abuts against the lower end face of the conical fine adjustment cover (13), and continue to rotate the nut to push the tip (9) out of the mounting conical hole, thus completing the removal and replacement of the tip (9).

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