Precise grinding clamp for taper hole of power head spindle

Abstract

The utility model provides a precise grinding clamp for a taper hole of a power head spindle, and belongs to the technical field of machining clamps. Comprising a fixing plate, a positioning support and an adjustable ejector head assembly, the fixing plate is connected with a grinding machine spindle box through a kidney-shaped hole bolt and synchronously rotates along with the grinding machine spindle box, and the positioning support is slidably connected with the fixing plate through a dovetail guide rail to achieve axial fine adjustment. The positioning support is provided with at least three radial adjustable top head assemblies which are evenly distributed in the circumferential direction, alloy top heads are driven by a lead screw mechanism to clamp the outer circle of the main shaft, and radial deviation and vibration are eliminated. The positioning column abuts against the step face of the main shaft to achieve axial limiting, and the device can be matched with main shafts of different sizes by combining a kidney-shaped hole adjusting mechanism. According to the clamp, high-precision coaxiality control is achieved through a composite adjusting system, the radial multi-point clamping and axial positioning functions are achieved, the taper hole grinding precision and the clamping efficiency are effectively improved, and the clamp is suitable for batch production.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of machining fixture, specifically relates to a power head main shaft taper hole precision grinding fixture. BACKGROUND

[0002] In the field of machining, internal cylindrical grinding machine is widely used in the finish machining of taper hole of main shaft parts. In the traditional grinding process, when the taper hole with angle requirement needs to be processed, the grinding machine spindle box needs to be rotated to a specific angle. This angle adjustment will cause the space position deviation between the main shaft box rotary axis and the machine tool slide rail, resulting in the complete failure of the original center frame of the grinding machine due to the non-parallelism between the installation base surface and the processing axis.

[0003] The current industry generally adopts the following two technical routes to solve the problem: one is the secondary clamping correction method, which requires the operator to manually correct the workpiece outer circle with a dial gauge after rotating the main shaft box to a certain angle. This method takes 15-20 minutes to correct a single piece, and the coaxiality error is generally in the range of 0.01-0.03mm, which is affected by the operator's technical level. The second is the custom combination fixture method, which installs the standard center frame on the adjustable angle transition plate through the design of a special angle conversion module. However, such devices have the defect of insufficient rigidity, and may produce elastic deformation of 0.005-0.01mm during grinding. At the same time, the modular combination leads to excessive axial size of the fixture, which is difficult to meet the space requirements of some high-precision main shaft clamping. The existing public technology CN205614433U is a grinding machine center frame, but its angle cannot be adjusted with the grinding machine. Some existing technologies also have common defects, such as the space pose deviation between the rotated main shaft box and the fixed guide rail, which causes the traditional center frame to lose the reference. Some adjustment mechanisms are bulky and interfere with the compact processing space of the main shaft. The superposition error and elastic deformation of some combined fixtures significantly affect the final processing precision.

[0004] The above technical bottlenecks directly restrict the batch production of precision main shafts, and the industry has been facing the pain points of low processing qualification rate and long auxiliary working hours for a long time. This situation has become a key problem that needs to be broken through to promote technological innovation in this field. UTILITY MODEL CONTENTS

[0005] The utility model proposes a high-precision self-adaptive fixture to solve the problems of reference failure, low clamping efficiency and insufficient precision caused by angle adjustment of the main shaft box in traditional main shaft taper hole grinding, which can solve the industry pain points of low qualification rate and long auxiliary time in main shaft taper hole processing, and meet the needs of high-precision, multi-specification and batch production.

[0006] The utility model provides a power head main shaft taper hole precision grinding fixture, including fixed plate, fixed plate bolt connection is in the top of grinding machine spindle box, fixed plate is equipped with swallow tail guide rail, swallow tail guide rail slidingly connects with positioning support, positioning support is equipped with one positioning hole, positioning hole is evenly distributed at least three radial adjustable top head assembly, positioning hole is equipped with one positioning groove, and the positioning column is placed in the positioning groove. Fixed plate bolt connection is in the top of grinding machine spindle box, and the fixed plate can rotate with the spindle box, and the angle of the fixture is changed together while the angle of the spindle box is changed, and the relative position of the positioning support and the spindle box is kept. The positioning support is used for positioning the spindle, the spindle is in the positioning hole, the spindle is clamped from the radial multi-point outer circle through the at least three circumferentially uniform distribution top head assembly, the spindle is ensured to have no radial deviation in the grinding process, the uniform stress of the multi-point can offset the grinding vibration, the spindle axis is avoided to be deflected due to unilateral stress, and the coaxiality precision of the taper hole and the spindle axis is ensured. The positioning column is limited to move along the axial direction through the abutment of the step surface (such as shaft shoulder or end surface) of the spindle, the axial degree of freedom is eliminated, the depth consistency of the taper hole grinding of the spindle is ensured, and the taper hole length is avoided to be out of tolerance due to axial movement. When the spindle is put into the three-jaw chuck, the positioning column provides axial prepositioning, assists the operator to quickly align the spindle position, shortens the clamping adjustment time, and is suitable for batch production. The positioning support can be moved on the swallow tail guide rail and finely adjusted, and the relative position of the fixture and the spindle is adjusted, so that the demand of different length spindles can be met.

[0007] A power head main shaft taper hole precision grinding fixture, the grinding machine spindle box is installed with three-jaw chuck, the three-jaw chuck is clamped with the main shaft, and the fixed plate is provided with the fixed plate waist hole extending along the axial direction of three-jaw chuck. The bolt for connecting the fixed plate and the spindle box is placed in the fixed plate waist hole, after the bolt is loosened, the fixed plate can slide along the long axis direction of the fixed plate waist hole, thereby adjusting the relative position of the fixture and the ground main shaft, so that the demand of different length spindles can be met without adjusting the fixture extension amount by reaming. The single hole position realizes continuous position adjustment, different size spindles are avoided to be customized with multiple fixed holes, the swallow tail structure is matched, and the composite adjustment system of the axial coarse adjustment of the fixed plate waist hole and the fine adjustment of the swallow tail guide rail is formed.

[0008] A power head main shaft taper hole precision grinding fixture, the positioning column bolt connection is in the positioning column fixed frame, and the surface of the positioning column fixed frame is equipped with fixed frame waist hole. The fixed frame waist hole can make the positioning column fixed frame move along the radial direction of the main shaft, and the main shaft of different outer circle sizes can be adapted.

[0009] The power head main shaft taper hole precision grinding clamp, the positioning support is provided with a dovetail groove, the dovetail groove is matched with the dovetail guide rail of the fixed plate, the end face of the dovetail groove is provided with a gap, the side face of the positioning support is provided with an adjusting bolt, and the adjusting bolt penetrates through the gap. The dovetail groove is matched with the dovetail guide rail of the fixed plate to provide high-precision linear sliding guidance for the positioning support, and the moving direction of the positioning support is strictly parallel to the axis of the grinding machine main shaft. The wedge-shaped structure of the dovetail section can bear the radial and overturning torque load in the grinding process, preventing the positioning support from deviating or vibrating. The gap is reserved at the end face of the dovetail groove to provide an elastic deformation allowance when the adjusting bolt is applied with a pressing force, the adjusting bolt is rotated to reduce the gap, the side wall of the dovetail groove is tightly fitted with the dovetail guide rail, the dovetail fitting is locked through slight deformation, and the loosening risk of the sliding pair is eliminated. When the position of the positioning support needs to be adjusted, the adjusting bolt can be loosened, the positioning support can be freely moved on the dovetail guide rail, and the relative position of the positioning support and the ground main shaft is adjusted.

[0010] The power head main shaft taper hole precision grinding clamp, the top head assembly includes an adjusting handle, the adjusting handle is threadedly connected with a lead screw, the other end of the lead screw extends into a radial through hole of the positioning support, a sleeve is fixedly embedded in the radial through hole, an inner thread matched with an outer thread of the lead screw is arranged on an inner wall of the sleeve, and an alloy top head is fixedly connected to a tail end of the lead screw. An operator drives the lead screw to move axially along the radial through hole by rotating the adjusting handle, the lead screw converts the rotating motion of the handle into the linear motion of the alloy top head, and radial position adjustment is realized. The sleeve is fixedly embedded in the radial through hole of the positioning support to provide linear motion guidance for the lead screw and limit radial swinging of the lead screw. The tail end of the alloy top head is in contact with the outer circle of the main shaft to provide uniform radial clamping force and eliminate radial jumping of the main shaft during grinding. The manual operation is converted into precise mechanical action through the multi-stage transmission mechanism of the adjusting handle, the lead screw, the sleeve and the alloy top head, and the demand for operation convenience and processing stability is perfectly balanced.

[0011] The power head main shaft taper hole precision grinding clamp, a fixed cover is sleeved at a position where the lead screw is attached to the outer surface of the positioning support, and a sealing ring is sleeved at a gap between the lead screw and the fixed cover. The fixed cover is fixed on the lead screw in the form of a compression ring to ensure the stability of the lead screw in the radial through hole. The sealing ring fills the annular gap between the lead screw and the fixed cover, blocks the entry of external dust or liquid into the radial through hole, and prolongs the service life of the lead screw. The elastic deformation of the sealing ring can absorb high-frequency micro-vibration in the grinding process, and reduce the impact load of the threaded pair.

[0012] The power head main shaft taper hole precision grinding clamp, the alloy top head abuts against the outer circle of the main shaft and is used together to fix the outer circle of the main shaft. The outer diameter of the main shaft is clamped in the top head, and the contact tightness of the alloy top head and the ground main shaft can be adjusted through the adjusting handle. After the adjustment of the two alloy top heads is completed, the alloy top heads are fixed through locking set screws, and when the main shaft is assembled or disassembled, only one of the alloy top heads needs to be locked or unlocked to complete the operation.

[0013] A precision grinding fixture for taper holes of a power head spindle, wherein a limiting boss is provided at the end of the positioning column for axial positioning of the spindle step surface.

[0014] A precision grinding fixture for taper holes of a power head spindle, comprising a positioning bracket including a positioning surface, a three-jaw chuck including a chuck side, and the axis of the spindle being perpendicular to the positioning surface and the chuck side.

[0015] The advantages of this invention are as follows: The synchronous rotation design of the fixed plate and the grinding machine spindle box eliminates the reference offset caused by spindle box angle adjustments, ensuring that the fixture positioning reference is always consistent with the machining axis. The combined adjustment system of the fixed plate's oblong hole for axial coarse adjustment and the dovetail guide rail for precision fine adjustment adapts to spindles of different lengths. Simultaneously, three circumferentially distributed radially adjustable mandrel assemblies achieve radial runout control, ensuring the coaxiality of the tapered hole and the spindle axis. The positioning pin is radially adjustable via the oblong hole of the fixed bracket, accommodating spindles of different outer diameters. This invention significantly solves the industry problems of low efficiency and poor precision in the mass production of tapered holes using precision spindles. Attached Figure Description

[0016] To more clearly illustrate the embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the fixture of this utility model installed on the spindle box of a grinding machine.

[0018] Figure 2 This is a schematic diagram of the positioning bracket of this utility model.

[0019] Figure 3 This is a schematic diagram of the top assembly of this utility model.

[0020] Figure 4 This is a schematic diagram of the positioning post and positioning post fixing frame of this utility model.

[0021] Figure 5 This is a schematic diagram of the fixing spindle of the top assembly of this utility model.

[0022] Figure Descriptions: 1-Fixed plate, 2-Positioning bracket, 3-Grinding machine spindle box, 4-Mandrel assembly, 11-Dovetail guide rail, 12-Fixed plate oblong hole, 21-Positioning hole, 23-Positioning pin, 24-Radial through hole, 25-Positioning pin fixing bracket, 26-Fixed bracket oblong hole, 27-Adjusting bolt, 28-Clearance, 29-Dovetail groove, 210-Positioning surface, 31-Three-jaw chuck, 32-Spindle, 41-Adjusting handle, 42-Lead screw, 43-Sleeve, 44-Alloy mandrel, 45-Sealing ring, 46-Fixed cover, 47-Set screw, 211-Positioning groove, 311-Chuck side. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Example 1:

[0025] See attached document Figure 1 Appendix Figure 2 Appendix Figure 3 Appendix Figure 5As shown, a precision grinding fixture for a power head spindle tapered hole includes a fixing plate 1, which is bolted to the top of the grinding machine spindle box 3. The fixing plate 1 is provided with a dovetail guide rail 11, and a positioning bracket 2 is slidably connected to the dovetail guide rail 11. The positioning bracket 2 is provided with a positioning hole 21, and at least three radially adjustable mandrel assemblies 4 are evenly distributed around the positioning hole 21. The positioning hole 21 is provided with a positioning groove 211, and a positioning pin 23 is placed in the positioning groove 211. The fixing plate 1 is bolted to the top of the grinding machine spindle box 3 and can rotate with the spindle box 3. When the spindle box 3 changes angle, the angle of the fixture changes simultaneously, maintaining the relative position of the positioning bracket 2 and the spindle box 3. The positioning bracket 2 is used to position the spindle 32. The spindle 32 is positioned within the positioning hole 21, and its outer diameter is clamped radially from multiple points by at least three circumferentially evenly distributed mandrel assemblies 4. This ensures that the spindle 32 does not shift radially during grinding. The uniform force at multiple points counteracts grinding vibrations and prevents axial misalignment of the spindle 32 due to unilateral force, thus guaranteeing the coaxiality accuracy between the tapered hole and the spindle 32 axis. The positioning pin 23, by abutting against the stepped surface (such as a shoulder or end face) of the spindle 32, restricts the spindle's movement along the axial direction, eliminating axial freedom and ensuring consistent grinding depth of the tapered hole, preventing excessive tapered hole length due to axial movement. When the spindle 32 is placed into the three-jaw chuck 31, the positioning pin 23 provides axial pre-positioning, assisting the operator in quickly aligning the spindle position, shortening clamping and adjustment time, and is suitable for mass production. The positioning bracket 2 can be moved on the dovetail guide rail 11 for fine adjustment to adjust the relative position of the fixture and the spindle 32, so as to adapt to the needs of spindles 32 of different lengths.

[0026] See attached document Figure 1 Appendix Figure 2 As shown, a precision grinding fixture for taper holes of a power head spindle is disclosed. A three-jaw chuck 31 is mounted on the spindle housing 3 of the grinding machine, clamping a spindle 32. A fixed plate 1 has a waist-shaped hole 12 extending along the axis of the three-jaw chuck 31. Bolts for connecting the fixed plate 1 and the spindle housing 3 are placed in the waist-shaped hole 12. After loosening the bolts, the fixed plate 1 can slide along the long axis of the waist-shaped hole 12, thereby adjusting the relative position of the fixture and the spindle 32 being ground. This adapts to the needs of spindles 32 of different lengths, allowing adjustment of the fixture extension without re-drilling. Continuous position adjustment is achieved through a single hole in the waist-shaped hole 12, avoiding the need to customize multiple sets of fixed holes for spindles of different sizes. Combined with a dovetail structure, this forms a composite adjustment system of coarse axial adjustment of the waist-shaped hole 12 and fine adjustment of the dovetail guide rail 11.

[0027] See attached document Figure 2 Appendix Figure 4 Appendix Figure 5As shown, a precision grinding fixture for the tapered hole of a power head spindle has a positioning pin 23 bolted to a positioning pin fixing frame 25. The surface of the positioning pin fixing frame 25 is provided with a fixing frame waist-shaped hole 26. The fixing frame waist-shaped hole 26 allows the positioning pin fixing frame 25 to move radially along the spindle 32, which can be adapted to spindles 32 with different outer diameters.

[0028] See attached document Figure 1 Appendix Figure 3 Appendix Figure 5 As shown, a precision grinding fixture for a power head spindle tapered hole includes a positioning bracket 2 with a dovetail groove 29. The dovetail groove 29 mates with the dovetail guide rail 11 of the fixed plate 1. A gap 28 is provided on the end face of the dovetail groove 29, and an adjusting bolt 27 is provided on the side of the positioning bracket 2, passing through the gap 28. The dovetail groove 29, in conjunction with the dovetail guide rail 11 of the fixed plate 1, provides high-precision linear sliding guidance for the positioning bracket 2, ensuring that the moving direction of the positioning bracket 2 is strictly parallel to the axis of the grinding machine spindle 32. The wedge-shaped structure of the dovetail section can withstand radial and overturning moment loads during the grinding process, preventing the positioning bracket 2 from shifting or vibrating. A gap 28 is reserved on the end face of the dovetail groove 29 to provide elastic deformation allowance when the adjusting bolt 27 applies clamping force. Rotating the adjusting bolt 27 reduces the gap 28, making the side wall of the dovetail groove 29 fit tightly against the dovetail guide rail 11. This slight deformation achieves dovetail locking, eliminating the risk of loosening of the sliding pair. When it is necessary to adjust the position of the positioning bracket 2, the adjusting bolt 27 can be loosened, and the positioning bracket 2 can move freely on the dovetail guide rail 11 to adjust the relative position of the positioning bracket 2 and the grinding spindle 32.

[0029] See attached document Figure 3 Appendix Figure 5 As shown, a precision grinding fixture for a power head spindle tapered hole includes a mandrel assembly 4 comprising an adjusting handle 41 threadedly connected to a lead screw 42. The other end of the lead screw 42 extends into a radial through-hole 24 of a positioning bracket 2. A sleeve 43 is fixedly embedded in the radial through-hole 24, and the inner wall of the sleeve 43 has an internal thread matching the external thread of the lead screw 42. An alloy mandrel 44 is fixedly connected to the end of the lead screw 42. By rotating the adjusting handle 41, the lead screw 42 is driven to move axially along the radial through-hole 24. The lead screw 42 converts the rotational motion of the handle 41 into the linear motion of the alloy mandrel 44, achieving radial position adjustment. The sleeve 43, fixedly embedded in the radial through-hole 24 of the positioning bracket 2, provides linear motion guidance for the lead screw 42 and restricts its radial oscillation. The end of the alloy mandrel 44 contacts the outer diameter of the spindle 32, providing a uniform radial clamping force and eliminating radial runout of the spindle 32 during grinding. By adjusting the multi-stage transmission mechanism of handle 41, lead screw 42, sleeve 43, and alloy mandrel 44, manual operation is transformed into precision mechanical action, perfectly balancing the needs of ease of operation and processing stability.

[0030] See attached document Figure 3As shown, a precision grinding fixture for a power head spindle tapered hole includes a fixed cover 46 fitted at the contact point between the lead screw 42 and the outer surface of the positioning bracket 2, and a sealing ring 45 fitted at the gap between the lead screw 42 and the fixed cover 46. The fixed cover 46 is fixed to the lead screw 42 in the form of a pressure ring to ensure the stability of the lead screw 42 in the radial through hole 24. The sealing ring 45 fills the annular gap between the lead screw 42 and the fixed cover 46, preventing external dust or liquid from entering the radial through hole 24 and extending the service life of the lead screw 42. The elastic deformation of the sealing ring 45 can absorb high-frequency micro-vibrations during the grinding process and reduce the impact load on the threaded pair.

[0031] See attached document Figure 3 Appendix Figure 5 As shown, a precision grinding fixture for a power head spindle tapered hole has alloy mandrels 44 abutting against the outer diameter of a spindle 32, collectively used to fix the outer diameter of the spindle 32. The outer diameter of the spindle 32 is held in place by three mandrels. The contact tightness between the alloy mandrels 44 and the spindle 32 being ground can be adjusted by adjusting the handle 41. After two alloy mandrels 44 are adjusted, they are fixed by locking set screws 47. When loading or unloading the spindle 32, it is only necessary to tighten and loosen the remaining alloy mandrel 44.

[0032] See attached document Figure 1 Appendix Figure 5 As shown, a precision grinding fixture for a power head spindle tapered hole has a limiting boss at the end of the positioning post 23 for axial positioning of the stepped surface of the spindle 32. The positioning bracket 2 includes a positioning surface 210, and the three-jaw chuck 31 includes a chuck side surface 311. The axis of the spindle 32 is perpendicular to the positioning surface 210 and the chuck side surface 311.

[0033] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the present utility model, and are not intended to limit the implementation methods of the present utility model in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the present utility model, but these should still be regarded as the same technology or embodiment as the present utility model.

[0034] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A power head main shaft taper hole precision grinding clamp, comprising a fixed plate (1), characterized in that: The fixed plate (1) is bolted on the top of the grinder spindle box (3), the fixed plate (1) is provided with a dovetail guide rail (11), the dovetail guide rail (11) is slidably connected with a positioning support (2), the positioning support (2) is provided with a positioning hole (21), the positioning hole (21) is uniformly distributed with at least three radial adjustable top head assemblies (4) in the circumferential direction, the positioning hole (21) is provided with a positioning groove (211), and the positioning groove (211) is placed with a positioning column (23).

2. The power head main shaft taper hole precision grinding clamp according to claim 1, characterized in that: The grinder spindle box (3) is provided with a three-jaw chuck (31), the three-jaw chuck (31) clamps a spindle (32), and the fixed plate (1) is provided with a fixed plate waist-shaped hole (12) extending along the axis direction of the three-jaw chuck (31).

3. The power head main shaft taper hole precision grinding clamp according to claim 1, characterized in that: The positioning column (23) is bolted to the positioning column fixing frame (25), and the surface of the positioning column fixing frame (25) is provided with a fixing frame waist-shaped hole (26).

4. The power head main shaft taper hole precision grinding clamp according to claim 1, characterized in that: The positioning support (2) is provided with a dovetail groove (29), the dovetail groove (29) is matched with the dovetail guide rail (11) of the fixed plate (1), the end face of the dovetail groove (29) is provided with a gap (28), and the side face of the positioning support (2) is provided with an adjusting bolt (27), the adjusting bolt (27) penetrates through the gap (28).

5. The power head main shaft taper hole precision grinding clamp according to claim 1, characterized in that: The top head assembly (4) comprises an adjusting handle (41), the adjusting handle (41) is threadedly connected with a lead screw (42), the other end of the lead screw (42) extends into a radial through hole (24) of the positioning support (2), the radial through hole (24) is fixedly embedded with a sleeve (43), the inner wall of the sleeve (43) is provided with internal threads matched with external threads of the lead screw (42), and the tail end of the lead screw (42) is fixedly connected with an alloy top head (44).

6. The power head main shaft taper hole precision grinding clamp according to claim 5, characterized in that: The lead screw (42) is sleeved with a fixed cover (46) at the position close to the outer surface of the positioning support (2), and a sealing ring (45) is sleeved at the gap between the lead screw (42) and the fixed cover (46).

7. The power head main shaft taper hole precision grinding clamp according to claim 5, characterized in that: The alloy top head (44) abuts against the outer circle of the spindle (32), and is used for fixing the outer circle of the spindle (32) together.

8. The power head main shaft taper hole precision grinding clamp according to claim 1, characterized in that: The end of the positioning column (23) is provided with a limiting boss for axially positioning the stepped surface of the spindle (32).

9. The power head main shaft taper hole precision grinding clamp according to claim 2, characterized in that: The positioning support (2) comprises a positioning surface (210), the three-jaw chuck (31) comprises a chuck side surface (311), and the axis of the spindle (32) is perpendicular to the positioning surface (210) and the chuck side surface (311).

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