CN114434227A

CN114434227A - Boring and grinding device for improving precision of outer cylindrical surface of part by taking inner hole as reference

Info

Publication number: CN114434227A
Application number: CN202210117436.3A
Authority: CN
Inventors: 凌四营; 刘远航; 王奉涛; 凌明; 刘祥生; 杨洋
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2022-02-08
Filing date: 2022-02-08
Publication date: 2022-05-06
Anticipated expiration: 2042-02-08
Also published as: CN114434227B

Abstract

A boring and grinding device for improving the precision of an outer cylindrical surface of a part by taking an inner hole as a reference comprises a rotating shaft, a connecting plate, V-shaped and T-shaped grinding blocks, a dense ball shaft sleeve and a sealing sleeve. The clamping shaft section in the rotating shaft can be clamped through a chuck of the machine tool; the connecting plate mounting flange is used for mounting a connecting plate; the workpiece mounting reference shaft section is matched with the dense ball shaft sleeve and the inner hole of the part. And two ends of the connecting plate are used for mounting two grinding blocks. When the boring and grinding machine works, a hand-held workpiece is not moved or slowly rotates around the axis of the rotating shaft, and the two grinding blocks rotate around the outer cylindrical surface of the part at a low speed along with the rotating shaft, so that the boring and grinding machining of the outer cylindrical surface of the part by taking the inner hole of the part as a reference is realized. The invention can effectively reduce the roundness error, the surface roughness and the circle jump error relative to the inner hole of the outer cylindrical surface of the part; the position of the grinding block can be adjusted according to the size of the workpiece and the thickness of the grinding material, the structure is simple, and the installation is convenient; the processing range of parts can be adjusted by replacing connecting plates and mandrels with different sizes, the adaptability is strong, and the device can be directly used on a lathe.

Description

Boring and grinding device for improving precision of outer cylindrical surface of part by taking inner hole as reference

Technical Field

The invention belongs to the technical field of precision machining and testing, and relates to a boring and grinding device for improving the precision of an outer cylindrical surface of a part by taking an inner hole as a reference.

Background

The machining and testing of a workpiece by utilizing the rotary motion of the workpiece is one of the common methods in the technical field of precision machining and testing, and the workpiece is usually installed on a mandrel by taking an inner hole as a reference during machining and testing, and then the mandrel is installed on a machine tool or a measuring instrument. For some high-precision workpieces taking inner holes as references, the mounting precision of the workpieces is inconvenient to measure because the inner holes of the workpieces are occupied during assembly, so a transition reference method is often adopted, an outer cylindrical surface with radial reference is processed on the workpieces as a transition reference, and the mounting precision of the workpieces is determined by measuring the radial run of the transition reference surface. Therefore, the reference outer cylindrical surface should have low roundness, roughness and radial run-out requirements with respect to the inner bore.

The invention discloses a method for improving the machining precision of an outer cylindrical surface of a part, which is mainly realized by a cylindrical grinding machine and cylindrical grinding, and the Chinese invention patent [ CN201410359407.3 ] provides a workpiece clamping device and a clamping method of the cylindrical grinding machine, solves the problems of inconvenient clamping and low clamping efficiency, and can ensure the coaxiality of a clamping axis and a workpiece axis. The cylindrical surface is machined by using the cylindrical grinding machine, a corresponding clamp needs to be designed, meanwhile, the noise is high, and clamping on the grinding machine is not easy to perform for large or special-shaped workpieces. The Chinese invention patent (CN 200710065661.2) discloses a tool for grinding an excircle, wherein an inner hole of the grinding tool related to the tool is eccentric relative to the excircle, and the shape of the deformed inner hole is adjusted by eccentricity, so that the inner hole is elliptical and poor in rigidity, and the improvement of the precision of a machined part is limited. For the existing excircle grinding device, in the actual use process, the defects of inconvenient use and poor influence generally exist. The invention patent (CN 202110608291.2) discloses an elastic grinding shaft sleeve with radial deformation and symmetric distribution and the invention patent (CN 201610888861.7) discloses a liquid expansion type inner hole precision grinding tool which can be used for precision grinding processing of an inner hole of a part but can not be directly used for ultra-precision grinding processing of a precision outer cylinder of the part. The invention patent (CN 201710435745.4) discloses a precision grinding device for the outer cylindrical surface of a disc part, which grinds the outer cylindrical surface of the disc part by using the ring polishing principle, but is not suitable for shaft parts or parts of which the outer cylindrical surface is smaller than the maximum radial maximum size of the part. For a small-sized outer cylindrical surface, a matched grinding shaft sleeve can be manufactured, and the roundness error and the surface roughness of the outer cylindrical surface are reduced by adopting a grinding method, but the circle jump and the full jump error of the outer cylindrical surface cannot be reduced.

Disclosure of Invention

In order to solve the problems, the patent provides a boring and grinding device for improving the precision of an outer cylindrical surface of a part by taking an inner hole as a reference, and the roundness error, the surface roughness and the circular run-out error relative to the inner hole of the outer cylindrical surface of the part are reduced in a grinding mode.

In order to achieve the purpose, the invention adopts the technical scheme that:

the boring and grinding device comprises a rotating shaft, a connecting plate, a V-shaped grinding block, a T-shaped grinding block, a dense ball shaft sleeve, an O-shaped sealing ring and a sealing sleeve.

The rotary shaft comprises a clamping shaft section, a connecting plate mounting flange and a workpiece mounting reference shaft section. The clamping shaft section can be clamped through a chuck of the machine tool to obtain rotary motion; a plurality of countersunk holes are formed in the mounting flange of the connecting plate and are used for mounting the connecting plate; the workpiece mounting reference shaft section is matched with the dense ball shaft sleeve and the inner hole of the part to form a rotary shaft system. The connecting plate is connected to a connecting plate mounting flange on the rotating shaft through a screw and rotates together with the rotating shaft; slotted holes are formed in two ends of the connecting plate and used for installing the V-shaped grinding block and the T-shaped grinding block. The V-shaped grinding block and the T-shaped grinding block made of cast iron or ceramic materials can be directly used for boring and grinding the outer cylindrical surface of a part, and grinding materials can be adhered to the grinding surfaces for boring and grinding. When the boring and grinding machine works, a hand-held workpiece is not moved or slowly rotates around the axis of the rotating shaft, and the two grinding blocks rotate around the outer cylindrical surface of the part at a low speed along with the rotating shaft, so that the boring and grinding machining of the outer cylindrical surface of the part by taking the inner hole of the part as a reference is realized.

Furthermore, a threaded hole is processed on the connecting plate of the device, so that the connecting plate can be conveniently connected to a connecting plate mounting flange of the rotating shaft; the mounting positions of the V-shaped grinding block and the T-shaped grinding block in the slotted hole are determined according to the diameter of the outer cylindrical surface of the part to be machined, the V-shaped grinding block and the T-shaped grinding block are fixed on the connecting plate through screws after adjustment is finished, and the slotted hole structure can realize machining of workpieces with outer cylindrical surfaces of different diameters.

Furthermore, mounting threaded holes are formed in the V-shaped grinding block and the T-shaped grinding block and used for fixing the V-shaped grinding block and the T-shaped grinding block on the connecting plate; the mounting surface is vertical to the working surface; the included angle between the two working surfaces of the V-shaped grinding block is between 90 and 120 degrees; one end of the connecting plate is connected with the V-shaped grinding block, and the other end of the connecting plate is connected with the T-shaped grinding block, so that three working surfaces are ensured to be simultaneously contacted with the outer cylindrical surface of the part, the effect of radial auxiliary positioning of the part is achieved, and the boring and grinding precision is improved; the grinding material needs to be replaced in time after being worn, or the working surface of the grinding block needs to be repaired by adopting a grinding process after being worn.

Furthermore, the O-shaped sealing ring and the sealing sleeve are respectively arranged on two sides of the workpiece, so that an abrasive and grinding impurities can be effectively prevented from entering a rotating shaft system, and the reference accuracy of rotation is prevented from being influenced.

The invention has the beneficial effects that:

the boring and grinding device for the outer cylindrical surface of the part can effectively reduce the roundness error, the surface roughness and the circular run-out error relative to the inner hole of the outer cylindrical surface of the part; the position of the grinding block can be adjusted according to the size of the workpiece and the thickness of the grinding material, the structure is simple, the installation is convenient, and the manufacturing cost is low; the machining range of parts can be adjusted by replacing connecting plates and mandrels with different sizes, the adaptability is strong, the clamping is simple and convenient, and the clamping device can be directly used on a lathe.

Drawings

FIG. 1 is a schematic diagram of a boring and milling apparatus.

FIG. 2 is a schematic diagram of workpiece boring.

Fig. 3 is a schematic view showing a structure of a rotating shaft.

Fig. 4 is a schematic diagram of a connection plate structure.

In the figure: 1, rotating a shaft; 1-1 clamping shaft section, 1-2 connecting plate mounting flanges, 1-3 counter bores and 1-4 workpiece mounting reference shaft sections; 2, connecting a plate; 2-1 slotted hole and 2-2 threaded hole; a 3V-shaped grinding block; 4, a dense ball shaft sleeve; 5T-shaped grinding blocks; 6O-shaped sealing rings; 7, workpiece; and 8, sealing the sleeve.

Detailed Description

The present invention is further illustrated by the following specific examples.

The boring and grinding device for improving the precision of the outer cylindrical surface of a part by taking an inner hole as a reference comprises a rotating shaft 1, a connecting plate 2, a V-shaped grinding block 3, a dense ball shaft sleeve 4, a T-shaped grinding block 5, an O-shaped sealing ring 6 and a sealing sleeve 8. The rotary shaft 1 comprises three parts, namely a clamping shaft section 1-1, a connecting plate mounting flange 1-2 and a workpiece mounting reference shaft section 1-4; the clamping shaft section 1-1 is clamped by a machine tool chuck to obtain rotary motion; the connecting plate mounting flange 1-2 is positioned between the clamping shaft section 1-1 and the workpiece mounting reference shaft section 1-4, and is provided with a plurality of counter bores 1-3 for mounting the connecting plate 2; the workpiece mounting reference shaft sections 1-4 are matched with the dense ball shaft sleeves 4 and inner holes of parts to form a rotary shaft system, wherein the dense ball shaft sleeves 4 are sleeved outside the workpiece mounting reference shaft sections 1-4. The middle part of the connecting plate 2 is provided with a through hole for penetrating through the rotating shaft 1, and the four corners of the plate-shaped structure are provided with threaded holes 2-2 which are connected to a connecting plate mounting flange 1-2 on the rotating shaft through screws and rotate together with the rotating shaft 1; rectangular strip structures are arranged at two ends of the connecting plate 2, and slotted holes 2-1 are formed in the strip structures and used for mounting a V-shaped grinding block 3 and a T-shaped grinding block 5; the V type grinding block 3 is connected to 2 one end of connecting plate promptly, and T type grinding block 5 is connected to one end in addition, guarantees that three working face contacts the outer face of cylinder of part simultaneously, plays the effect of the radial assistance-localization real-time of part for improve boring and grinding precision. The V-shaped grinding block 3 and the T-shaped grinding block 5 can be directly used for boring and grinding the outer cylindrical surface of a part, and grinding materials can be adhered to the grinding surfaces for boring and grinding; the mounting positions of the V-shaped grinding block 3 and the T-shaped grinding block 5 in the slotted hole 2-1 are determined according to the diameter of the outer cylindrical surface of the part to be machined, the V-shaped grinding block and the T-shaped grinding block are fixed on the connecting plate 2 through screws after adjustment is finished, and the slotted hole structure can realize machining of workpieces with outer cylindrical surfaces of different diameters. The O-shaped sealing ring 6 and the sealing sleeve 8 are respectively arranged at two sides of the workpiece 7 and are used for preventing grinding agent and grinding impurities from entering a rotary shaft system and avoiding influencing the rotary reference precision.

In the embodiment, a gear involute sample plate with an inner hole diameter of 50mm and an outer cylindrical surface diameter of 70mm is taken as an example to illustrate a specific implementation mode of the device. The method comprises the following specific steps:

the rotating shaft 1 is divided into three sections with the diameters of

Clamping the clamping shaft section 1-1 by using a three-jaw chuck; the end face of a mounting flange 1-2 of the connecting plate is provided with six uniformly distributed counter bores 1-3, the connecting plate is connected with the connecting plate 2 by utilizing an M5 hexagon socket head cap screw, and when the device is used, two counter bores do not participate in the work, so that the standby replacement effect is realized; an inward tool withdrawal groove is designed on the shaft section in contact with the connecting plate 2, so that the end face can be conveniently ground, and the perpendicularity tolerance between the inward tool withdrawal groove and the workpiece mounting reference shaft section 1-4 is required to be less than 2 micrometers; the workpiece mounting reference shaft sections 1-4 are matched with the dense ball shaft sleeve 4 to mount the workpiece, and the full run-out error is required to be less than 1 micrometer due to the fact that the inner hole is used as a reference to process. The center of the connecting plate 2 is processed with

The through hole is sleeved on the rotating shaft and connected with the end face part by 4M 5 socket head cap screws, a boss with the diameter of 1mm is designed at the part in contact with the end face, the grinding is convenient, the ground end face is used for positioning during installation, and the installation precision is improved. Slotted holes 2-1 with the width of 5.6mm and the length of 25.6mm are arranged at the two ends of the connecting plate 2 and are used for installing the V-shaped grinding block 3 and the T-shaped grinding block 5. The V-shaped grinding block 3 is provided with two working surfaces, and the perpendicularity tolerance between the V-shaped grinding block and the positioning surface is required to be less than 1 mu m; the T-shaped grinding block 5 is provided with a working surface, the flatness tolerance of which is less than 1 mu m, and the perpendicularity tolerance of which with the positioning surface is less than 1 mu m; two threaded holes are processed on the mounting parts of the two grinding blocks and are respectively used for two MThe 5 socket head cap screws are connected with the connecting plate 2 through the slotted holes 2-1 of the connecting plate, so that the connecting rigidity can be effectively improved, the grinding block can be prevented from rotating around a screw to influence the processing effect, and the mounting surface of the connecting plate 2 and the positioning surface of the grinding block require that the parallelism tolerance is less than 2 mu m. The dense ball shaft sleeve 4 uses G3 or G5 grade spherical rolling bodies with the diameter of 4.7625mm, the material can be selected from bearing steel or silicon carbide, the hardness is not lower than HRC60, and dense balls are spirally and uniformly distributed; the outside of the dense ball shaft sleeve 4 is arranged in a reference inner hole of an involute, so that the unilateral interference amount between a high-precision steel ball on the dense ball shaft sleeve 4 and the involute inner hole is controlled to be 1-3 mu m. The sealing sleeve 7 is a cylindrical rubber block with the diameter of

A height of 31mm and a middle opening

And a hole with the height of 28mm is sleeved on the outer cylindrical surface of the reference of the non-processing side of the workpiece after the workpiece is installed, so that the grinding agent is prevented from entering the inner hole. The O-shaped sealing ring 6 is selected to be 40mm in inner diameter and 6mm in wire diameter, and the sealing ring needs to be installed firstly before a workpiece is installed, so that a good sealing effect is achieved, the inner hole of the workpiece is protected, and grinding agents and removed materials are prevented from entering the inner hole to damage the movement precision.

The application comprises the following steps:

1) fixing a connecting plate 2 to a connecting plate mounting flange 1-2 of the rotating shaft 1; then installing an O-shaped sealing ring 6; firstly, the dense ball shaft sleeve is matched with an inner hole of a workpiece and then is arranged on a workpiece mounting reference shaft section together; when the V-shaped grinding block 3 and the T-shaped grinding block 5 are installed, the two sides of the grinding block are pressed onto the outer cylindrical surface of a workpiece together with 5-10N force, proper positive pressure is guaranteed, the three-direction pressure of the workpiece is reasonably close to 0, and then screws of the two grinding blocks are screwed down to be fixed to the two ends of the connecting plate 2;

2) mounting a seal sleeve 8 on the outer cylindrical surface of the non-machined side of the workpiece 7 to completely seal the tail end of the shaft and the inner hole of the workpiece; coating the grinding agent of W3-W10 on the surface to be bored and ground of the workpiece 7;

3) the whole device is installed on a lathe, a main shaft of the lathe is started at the speed of 40-90 r/min, and a person holds the workpiece 7 with both hands immovably or slowly rotates around a rotating shaft line at a constant speed to finish boring and grinding. Along with the grinding, after the grinding pressure is reduced, the connecting screws of the V-shaped grinding block 3, the T-shaped grinding block 5 and the connecting plate 2 can be loosened, the two grinding blocks are pressed on the workpiece again, and a new round of grinding is carried out until the precision requirement is met. When the precision of the grinding surface of the grinding block is reduced, the precision of the grinding surface of the grinding block needs to be repaired through a grinding process.

It will be apparent to those skilled in the art that equivalent substitutions or changes can be made in accordance with the patented technical solution and the specific embodiments thereof, and all such changes or substitutions are intended to be within the scope of the present invention.

Claims

1. A boring and grinding device for improving the precision of an outer cylindrical surface of a part by taking an inner hole as a reference is characterized by comprising a rotating shaft (1), a connecting plate (2), a V-shaped grinding block (3), a dense ball shaft sleeve (4) and a T-shaped grinding block (5);

the rotary shaft (1) comprises a clamping shaft section (1-1), a connecting plate mounting flange (1-2) and a workpiece mounting reference shaft section (1-4); the clamping shaft section (1-1) is clamped by a machine tool chuck to obtain rotary motion; the connecting plate mounting flange (1-2) is positioned between the clamping shaft section (1-1) and the workpiece mounting reference shaft section (1-4), and is provided with a plurality of counter bores (1-3) for mounting the connecting plate (2); the workpiece mounting reference shaft sections (1-4) are matched with the dense ball shaft sleeves (4) and the inner holes of the parts to form a rotary shaft system, wherein the dense ball shaft sleeves (4) are sleeved outside the workpiece mounting reference shaft sections (1-4);

the middle part of the connecting plate (2) is provided with a through hole for penetrating through the rotating shaft (1), four corners of the plate-shaped structure are provided with threaded holes (2-2), and the connecting plate is connected to a connecting plate mounting flange (1-2) on the rotating shaft through screws and rotates together with the rotating shaft (1); rectangular strip structures are arranged at two ends of the connecting plate (2), and slotted holes (2-1) are formed in the strip structures and used for mounting the V-shaped grinding block (3) and the T-shaped grinding block (5); one end of the connecting plate (2) is connected with the V-shaped grinding block (3), and the other end of the connecting plate is connected with the T-shaped grinding block (5), so that three working surfaces are ensured to be simultaneously contacted with the outer cylindrical surface of the part, the effect of radial auxiliary positioning of the part is achieved, and the boring and grinding precision is improved;

the V-shaped grinding block (3) and the T-shaped grinding block (5) can be directly used for boring and grinding the outer cylindrical surface of a part, and grinding materials can be adhered to the grinding surface for boring and grinding; the mounting positions of the V-shaped grinding block (3) and the T-shaped grinding block (5) in the slotted hole (2-1) are determined according to the diameter of the outer cylindrical surface of the part to be processed, the V-shaped grinding block and the T-shaped grinding block are fixed on the connecting plate (2) through screws after adjustment is finished, and the slotted hole structure can realize processing of workpieces with outer cylindrical surfaces of different diameters;

when the boring and grinding machine works, the hand-held workpiece (7) is not moved or slowly rotates around the axis of the rotating shaft (1), and the two grinding blocks rotate around the outer cylindrical surface of the part at a low speed along with the rotating shaft (1), so that the boring and grinding machining of the outer cylindrical surface of the part by taking the inner hole of the part as a reference is realized.

2. A boring and grinding device for improving the accuracy of the outer cylindrical surface of a part with an internal hole as a reference according to claim 1, characterized in that the V-shaped grinding block (3) and the T-shaped grinding block (5) are made of cast iron or ceramic materials.

3. A boring and grinding device for improving the precision of an outer cylindrical surface of a part by taking an inner hole as a reference according to claim 1, characterized in that the mounting surfaces of the V-shaped grinding block (3) and the T-shaped grinding block (4) are vertical to the working surface; and the included angle of the two working surfaces of the V-shaped grinding block (3) is between 90 and 120 degrees.

4. The boring and grinding device for improving the accuracy of the outer cylindrical surface of a part by taking an inner hole as a reference according to claim 1, characterized by further comprising an O-shaped sealing ring (6) and a sealing sleeve (8), wherein the O-shaped sealing ring (6) and the sealing sleeve (8) are respectively arranged on two sides of the workpiece (7) and are used for preventing grinding agents and grinding impurities from entering a rotary shaft system and avoiding influencing the rotary reference accuracy.