CN210588653U

CN210588653U - Device for polishing arc surface of workpiece

Info

Publication number: CN210588653U
Application number: CN201921340952.2U
Authority: CN
Inventors: 范朝阳; 赵华
Original assignee: Jingzhou Huanqiu Automobile Parts Manufacturing Co ltd
Current assignee: Jingzhou Huanqiu Automobile Parts Manufacturing Co ltd
Priority date: 2019-08-19
Filing date: 2019-08-19
Publication date: 2020-05-22
Anticipated expiration: 2029-08-19

Abstract

The utility model provides a device of polishing work piece arc surface, including work piece fixed unit, lift unit, control the mobile unit, polishing belt function unit to and the hinge pine presss from both sides the unit. The workpiece fixing unit mainly plays a role in fixing a workpiece; the lifting unit drives the polishing mechanism fixing rod to lift through the lifting cylinder, the polishing mechanism fixing rod is lifted to be in a non-working state, and the polishing mechanism fixing rod is lowered to be in a working state; the left-right moving unit finishes polishing a wider arc surface through the control handle; the hinge loose clamping unit controls the completion of the operation of the hinge loose clamp through the hinge loose clamping cylinder, the hinge loose clamp is in a non-working state, and the hinge loose clamp is in a working state. The utility model provides a polishing of connecting rod circular arc surface that polishing work piece arc surface's device can realize the contained angle about 200, and simple structure, and the clamping is swift, convenient to use, machining efficiency are high, the polishing precision is high, labour saving and time saving.

Description

Device for polishing arc surface of workpiece

Technical Field

The utility model relates to a device of polishing work piece arc surface belongs to machining technical field.

Background

The connecting rod is a member connecting the piston and the crankshaft, and functions to convert the reciprocating motion of the piston into the rotational motion of the crankshaft and to transmit the force acting on the piston to the crankshaft to output power. The stress condition of the connecting rod is complex in work, and the connecting rod is under the action of alternating tensile stress and alternating pressure stress and also under the action of bending stress. Because of the complex stress condition of the connecting rod, strict requirements are imposed on the precision of the connecting rod shape.

The requirements on roundness and roughness of the outer surface of the arc of the big end of the connecting rod are high, and the roughness of the outer surface of the arc of the big end of the connecting rod produced by the company is very strict and is required to be 0.12 micron. The existing polishing method is to add a tool clamp on a milling machine, clamp a connecting rod on the milling machine and polish in a mode of rotating a connecting rod workpiece, and because a product is heavy, and rotation and polishing are controlled manually, the operation is time-consuming and labor-consuming, and the polishing precision is difficult to guarantee. The surface of the special connecting rod workpiece to be polished is not a complete cylindrical surface, but a section of arc surface with an included angle of about 200 degrees, and because the included angle exceeds 180 degrees, part of the arc surface to be polished is positioned below the central line of the big end of the connecting rod, so that the polishing difficulty is high.

Disclosure of Invention

In order to solve the deficiencies existing in the prior art, the utility model provides a device of polishing work piece arc surface, the device can realize the polishing of the connecting rod circular arc surface of the contained angle about 200, and simple structure, and the clamping is swift, convenient to use, machining efficiency are high, the polishing precision is high, labour saving and time saving.

The utility model discloses a solve the technical scheme that its technical problem adopted and be: a device for polishing the arc surface of a workpiece comprises a base and a bearing frame arranged above the base, wherein a lifting unit is arranged on the bearing frame and comprises a telescopic mechanism connected to the bearing frame and a polishing mechanism fixing rod arranged below the telescopic mechanism, and the telescopic mechanism can drive the polishing mechanism fixing rod to realize lifting action;

the polishing belt operation unit is arranged below the polishing mechanism fixing rod and comprises a motor arranged below the inner section of the polishing mechanism fixing rod, a driving wheel is mounted on an output shaft of the motor, a sliding rail is arranged below the outer section of the polishing mechanism fixing rod, a driven wheel moving seat provided with a sliding block can move along the sliding rail through the sliding block, a driven wheel is arranged at the lower part of the driven wheel moving seat, an annular polishing belt is sleeved on the driving wheel and the driven wheel, the driven wheel moving seat is connected with a piston rod of a polishing belt elastic cylinder, the polishing belt elastic cylinder is fixed on the polishing mechanism fixing rod between the driving wheel and the driven wheel, and a magnetic switch is arranged at;

the hinge loose clamp unit is arranged in the middle of a fixed rod of the polishing mechanism and comprises a hinge loose clamp cylinder arranged above a polishing belt loose clamp cylinder, the hinge loose clamp cylinder is fixed on a support body on a hinge through a cylinder connecting seat, the support body on the hinge is fixed below the fixed rod of the polishing mechanism, a support body before the hinge and a support body after the hinge are arranged below the support body on the hinge, the middle parts below the support body before and after the hinge are provided with openings, a hinge loose clamp connecting seat is arranged below a piston rod of the hinge loose clamp cylinder, a rotatable movable plate is arranged at the front end of the hinge loose clamp connecting seat, a clamping groove is arranged below the movable plate, a follow-up pin is arranged in the middle part below the support body on the hinge, the follow-up pin is arranged along the vertical direction of the fixed rod of the polishing mechanism, the rear end of the follow-up pin is connected with the hinge loose clamp connecting seat, when the clamping seat below the movable plate is clamped into the front end of the follow-, the servo pin is connected with a pair of hinge clamp arms, the lower end of each hinge clamp arm is movably connected with a hinge clamp, the middle of each hinge clamp is connected with the front support body and the rear support body of the hinge through a pin shaft A, guide wheels A are arranged at the bottoms of the hinge clamps, the polishing belt below the hinge clamps is in contact with the two guide wheels A, and the polishing belt above the hinge clamps penetrates through the lower portion of the support body on the hinge.

The further improvement of the scheme is as follows: the base is provided with a workpiece fixing unit, and the workpiece fixing unit comprises more than one rapid clamp and a limiting block.

The telescopic mechanism comprises a lifting cylinder and a lifting seat, the lifting cylinder is fixed on the bearing frame, the lifting seat is fixedly connected with a piston rod below the lifting cylinder, lifting seat guide rails are longitudinally and respectively arranged at the positions, corresponding to the lifting seat, of the bearing frame, and the lifting cylinder can drive the lifting seat to move up and down along the lifting seat guide rails.

The polishing mechanism is characterized in that a left-right moving unit is arranged below the telescopic mechanism and comprises a polishing mechanism slide rail arranged below the telescopic mechanism, the polishing mechanism slide rail is arranged along the vertical direction of a polishing mechanism fixing rod, and the polishing mechanism fixing rod is movably connected to the polishing mechanism slide rail and can slide along the polishing mechanism slide rail.

And a balancing weight is arranged at the tail part of the inner section of the fixed rod of the polishing mechanism.

And a handle is arranged at the outer end of the fixed rod of the polishing mechanism.

Guide wheels B are respectively arranged on two sides of the follow-up pin, the arrangement direction of the guide wheels B is consistent with that of the follow-up pin, the guide wheels B are connected between the front support body and the rear support body of the hinge, and the polishing belt on the guide wheels B penetrates through the lower portion of the support body on the hinge and is in contact with the guide wheels B.

Hinge side supports are respectively arranged on two sides of the front hinge support and the rear hinge support, the rear hinge support is fixed on the hinge support, the hinge side supports are fixed on the rear hinge support, the front hinge support is fixed on the two hinge side supports, and mutually-communicated holes are reserved among the front hinge support, the hinge side supports and the hinge support.

A through hole is formed below the air cylinder connecting seat, and the polishing mechanism fixing rod penetrates through the through hole.

According to the technical scheme of the utility model, the tightness of the polishing belt of the utility model is controlled by the polishing belt elastic cylinder, the piston rod of the polishing belt elastic cylinder can drive the driven wheel moving seat to move, and the piston rod of the polishing belt elastic cylinder can be driven to retract when the polishing belt contracts so as to keep the polishing belt in a tensioning state at any time, thereby ensuring uniform stress when the workpiece is polished and ensuring the polishing precision; a piston rod of the hinge loose clamp cylinder drives the hinge loose clamp connecting seat, a movable plate on the hinge loose clamp connecting seat is clamped into the end part of the follow-up pin and drives the follow-up pin to move up and down, the up and down movement of the follow-up pin drives the hinge clamp to realize the functions of loosening and clamping, and when the hinge clamp is clamped, the polishing belt can be just contacted with the arc surface to be polished so as to realize the polishing of the arc surface of the connecting rod with an included angle of 200 degrees; the workpiece fixing device is a quick clamp and a limiting block, so that the cost is low, and the use and the maintenance are convenient; the handle at the outer end of the polishing mechanism fixing rod is operated, so that the polishing mechanism fixing rod can swing left and right along the polishing mechanism sliding rail, and the polishing of connecting rod arc surfaces with different widths can be realized; because the through holes are formed among the upper support body of the hinge, the side support body of the hinge and the front support body of the hinge, when the polishing belt needs to be replaced, the polishing belt can be taken down only by pulling the movable plate upwards, and the polishing belt is very convenient to disassemble and assemble; the setting up of a plurality of leading wheels can make the polishing belt position more reliable and reduce the friction to the polishing belt when the function, prolongs the life of polishing belt to reduce the error that the polishing belt off tracking brought, make the polishing more accurate.

Drawings

Fig. 1 is a schematic structural diagram of the device in the operating state of the present invention.

Fig. 2 is a schematic structural diagram of the device in a non-operating state.

Fig. 3 is a schematic view of the internal structure of the hinge clamping mechanism at a in fig. 2.

Fig. 4 is a schematic view of the support before the hinge.

Fig. 5 is a front view of the external structure of the hinge unclamping unit after combination of fig. 3 and 4.

Fig. 6 is a reverse view of the external structure of the hinge unclamping unit of fig. 3 and 4 in combination.

Figure 7 is a schematic view of the hinged clamp in a released condition.

Fig. 8 is a schematic view of the hinge clamp in a clamped state.

In the figure: 1. the automatic polishing machine comprises a base, 2 rapid clamps, 3 driven wheels, 4 polishing belts, 5 polishing mechanism fixing rods, 6 hinge rear supporting bodies, 7 lifting seats, 8 driving wheels, 9 lifting seat guide rails, 10 bearing frames, 11 lifting cylinders, 12 limiting blocks, 13 handles, 14 driven wheel moving seats, 15 connecting rod workpieces, 16 polishing belt tensioning cylinders, 17 magnetic switches, 18 motors, 19 balancing weights, 20 connecting rod workpiece arc surface included angles of 200 degrees, 21 baffles, 22 guide wheels A, 23 guide wheels B, 24 hinge upper supporting bodies, 25 follow-up pins, 26 cylinder connecting seats, 27 hinge loose clamping cylinders, 28 hinge pins B, 29 hinge clamps, 30 hinge pins A, 31 hinge connecting mandrels, 32 hinge clamp arms, 33 hinge pins C, 34 locking nuts, 35 loose plates, 36 loose plate rotating mandrels, 37. hinge loose clamp connecting seat, 38 hinge side support, 39 hinge front support, 101 cross bar.

Detailed Description

The present invention will be further explained with reference to the drawings and examples.

As shown in fig. 1 to 6, the device for polishing a circular arc surface of a workpiece provided in this embodiment includes a lifting unit, a polishing belt operating unit, a hinge releasing and clamping unit, a workpiece fixing unit, and a left-right moving unit. The workpiece in this embodiment is the connecting rod workpiece 15, and the arc surface to be polished is an arc surface of the connecting rod workpiece, and the included angle of the arc surface is 200 °, as shown by 20 in fig. 7.

The lifting unit comprises a base 1 and a bearing frame 10 arranged above the base, a cross rod 101 is arranged in the middle of the top surface of the bearing frame 10, a lifting cylinder 11 of the lifting unit is fixed below the cross rod 101, the air source of the lifting cylinder 11 is controlled by two reversing air sources, namely a three-position five-way manual control valve, a valve core is reversed at one position and three positions, and is closed at two positions. The piston rod below fixedly connected with rectangle frame construction of lift cylinder 11 goes up and down seat 7, vertically along the frame pole on four frame poles of the vertical direction of bearing frame 10 and is provided with lift seat guide rail 9, four corners swing joint of lift seat 7 are on lift seat guide rail 9, and lift cylinder 11 can drive lift seat 7 and can follow lift seat guide rail 9 and slide from top to bottom. The polishing mechanism fixing rod 5 is arranged below the bearing frame 10 and extends to the outside of the bearing frame 10.

The left-right moving unit is arranged below the lifting seat 7 and comprises polishing mechanism slide rails arranged below the front frame rod and the rear frame rod of the lifting seat 7, the polishing mechanism slide rails are grooves arranged below the front frame rod and the rear frame rod of the lifting seat 7, a slide block is arranged on the polishing mechanism fixing rod 5, the upper part of the slide block is positioned in the polishing mechanism slide rails, a handle 13 is arranged at the outer end of the polishing mechanism fixing rod, and the handle 13 is operated to enable the polishing mechanism fixing rod 5 to slide along the polishing mechanism slide rails;

the polishing belt operation unit is arranged below the polishing mechanism fixing rod 5 and comprises a three-phase asynchronous motor 18 arranged below the inner section of the polishing mechanism fixing rod 5, a driving wheel 8 is mounted on an output shaft of the motor, a balancing weight 19 is arranged at the tail part of the inner section of the polishing mechanism fixing rod 5 behind the motor 18, a sliding rail is arranged below the outer section of the polishing mechanism fixing rod 5, a sliding block is arranged on a driven wheel moving seat 14 and is positioned in the sliding rail and can slide along the sliding rail, a fixing shaft is connected to the lower part of the driven wheel moving seat 14, one end of the fixing shaft is fixedly connected with the driven wheel moving seat 14 through a bolt, the other end of the fixing shaft is fixedly connected with a circular baffle, a hollow driven wheel 3 is mounted between the baffle 21 and the driven wheel moving; the upper portion of the driven wheel moving seat 14 is connected with a piston rod of a polishing belt elastic air cylinder 16, the polishing belt elastic air cylinder 16 is fixed on a driving wheel 8 and a polishing mechanism fixing rod 5 between driven wheels 3, a magnetic switch 17 is arranged at the tail of the polishing belt elastic air cylinder 16, an air source of the polishing belt elastic air cylinder 16 is a single-path air source, only the piston rod of the polishing belt elastic air cylinder extends out of one path of air source, and the air source is controlled by a manual air valve.

The hinge unclamping unit is arranged in the middle of the fixed rod 5 of the polishing mechanism and comprises a hinge unclamping air cylinder 27 arranged above the polishing belt elastic air cylinder 16, an air source of the hinge unclamping air cylinder 27 is controlled by two-way reversing air sources, namely a two-position five-way single-head electromagnetic control valve, and the electromagnetic control valve of the hinge unclamping air cylinder 27 is linked to be switched on while the magnetic switch 17 is switched on. The hinge loose clamping air cylinder 27 is fixed on the hinge upper supporting body 24 through two air cylinder connecting seats 26 with a reversed V-shaped frame structure, and the polishing mechanism fixing rod 5 penetrates through the two air cylinder connecting seats 26. The upper hinge support body 24 is fixed below the polishing mechanism fixing rod 5, the front hinge support body 39 and the rear hinge support body 6 are arranged below the upper hinge support body 24, the front hinge support body and the rear hinge support body are similar to a concave shape, and the convex positions at two sides and the concave position in the middle of the concave plate are both arc-shaped; hinge side supports 38 are respectively arranged on two sides of the hinge front support and the hinge rear support, the hinge side supports 38 are fixed on the hinge rear support 6, the hinge front support 39 is fixed on the two hinge side supports 38, and through holes are reserved among the hinge front support 39, the hinge side supports 38 and the hinge upper support 24. The lower part of a piston rod of a hinge loose clamp air cylinder 27 is connected with an upper frame of an L-shaped hinge loose clamp connecting seat 26, the front end surface of the upper frame of the hinge loose clamp connecting seat 26 is connected with a movable plate 35 through a movable plate rotating mandrel 36, the movable plate 35 is arranged on the outer side of a hinge front supporting body 39, the movable plate 35 can rotate around the movable plate rotating mandrel 36, a clamping groove is arranged below the movable plate 35, a following pin 25 is arranged in the middle part below a hinge upper supporting body 24, the following pin 25 is positioned between the hinge front and rear supporting bodies and is arranged in the vertical direction with the hinge front and rear supporting bodies, two ends of the following pin 25 are exposed out of the hinge front and rear supporting bodies, a strip-shaped hole is arranged in the vertical direction at the position of the hinge front and rear supporting bodies corresponding to the following pin 25, the rear end of the following pin 25 passes through the strip-shaped hole on the hinge rear supporting body 6 to be fixedly connected with the vertical frame of the hinge loose clamp, corresponding with the draw-in groove position of loose plate 35 below, when loose plate 35 below draw-in groove card goes into the follow-up pin 25 and exposes the section, through the lock nut 34 of screwing the setting at the forward end portion of follow-up pin 25 with loose plate 35 chucking, hinge pine presss from both sides cylinder 27 accessible loose plate 35 and drives follow-up pin 25 and reciprocate along the bar hole of hinge front and back backup pad. Guide wheels B23 are respectively arranged on two sides of the follow-up pin 25, the direction of the guide wheel B23 is consistent with that of the follow-up pin 25, and the guide wheel B23 is connected between the front and rear supports of the hinge through a pin shaft C33. A pair of hinge tong arms 32 are connected to the follow-up pin 25, the upper ends of the hinge tong arms 32 are movably connected with the follow-up pin 25 respectively, the lower end of each hinge tong arm 32 is hinged to the hinge clamp 29 through a hinge connecting mandrel 31, the lower part of each hinge clamp 29 is provided with a hinge jaw, the hinge jaw is provided with a front jaw and a rear jaw, the middle part of the hinge clamp 29 is provided with a pin hole, a pin shaft A30 is installed in the pin hole, the two hinge clamps 29 are connected with a front hinge support body and a rear hinge support body through a pin shaft A30 respectively, and a hollow guide wheel A22 penetrates through a pin shaft B28 and is; the upper polishing belt of the endless polishing belt 4 passes through the lower side of the upper hinge support 24 and contacts with two guide wheels B23, and the lower polishing belt contacts with two guide wheels a 22.

The workpiece fixing unit comprises two quick clamps 2 arranged on the fixed seat 1 and a limiting block 12.

The position of a piston rod of the lifting cylinder extending out of the lower limit position is a positioning point of the hinge loose clamp unit descending to the upper surface of the workpiece. The hinge jaw is clamped in place, namely the hinge loose clamp cylinder 27 piston rod extends to the position limited by the cylinder body, and at the moment, the polishing belt 4 passes through the guide wheel A22 to reach the end point of the arc surface of the connecting rod workpiece 15 in a tangent relation, so that the polishing belt 4 is ensured to be stressed the same as the arc surface to be polished, and the polishing high-precision requirement is met.

The working principle of the utility model is as follows: firstly, hoisting a connecting rod workpiece 15, placing the connecting rod workpiece on a base 1, tightly leaning against a limiting block 12, and then pulling two rapid clamps 2 to lock the connecting rod workpiece 15; rotating the movable plate 35 to clamp the clamping groove on the movable plate 35 into the front end of the follow-up pin 25, screwing the locking nut 34, opening the total air source, controlling one path of air source, which is ahead of the piston rod of the polishing belt elastic cylinder 16, to be opened, wherein the path of air source is in an open state in other time except when the polishing belt 4 needs to be replaced, and the polishing belt 4 is always in a tight state; opening an air source valve extending downwards from a piston rod of a lifting cylinder 11 to enable the piston rod of the lifting cylinder 11 to extend out, driving a lifting seat 7 to descend by the piston rod of the lifting cylinder, driving a polishing mechanism fixing rod 5 to descend by the lifting seat 7, and enabling a polishing belt 4 to be in contact with the arc surface of a connecting rod workpiece 15 in the descending process, and enabling the piston rod of a polishing belt tightening cylinder 16 to contract under stress to keep the polishing belt 4 in a tightening state all the time; when the piston rod of the lifting cylinder 11 extends to the lower limit point, the piston rod can be positioned on the surface to be processed of the connecting rod workpiece 15, and the magnetic switch 17 on the tail of the polishing belt elastic cylinder 16 is switched on; the magnetic switch 17 is switched on to enable a piston rod of a hinge loose clamping air cylinder 27 clamped by the linkage hinge to extend out, the force of the extension of the piston rod of the hinge loose clamping air cylinder downwards presses the follow-up pin 25 through a hinge loose clamping connecting seat 37, the follow-up pin 25 moves downwards along strip-shaped holes in front and rear supporting bodies of the hinge, the follow-up pin 25 drives a hinge tong arm 32, and the hinge tong arm 32 drives a hinge tong 29 to rotate along a pin shaft A30 to clamp the hinge; the position where the hinge is clamped in place is the position where the polishing belt 4 is tangent to the end point of the arc surface of the connecting rod workpiece 15, and the stress of the polishing belt 4 and the arc contact surface to be polished is the same under the state; starting the motor 18, slowly rotating the motor 18 under the action of the frequency converter, then increasing the speed to reach a constant speed, driving the driving wheel 8 to rotate by the output shaft of the motor, driving the driven wheel 3 to rotate by the driving wheel 8, so that the polishing belts 4 arranged on the driving wheel 8 and the driven wheel 3 rotate to finish the polishing action, and guiding and friction reducing effects are exerted on the polishing belts 4 by the guide wheel A22 and the guide wheel B23 during rotation; when the arc surface of the connecting rod workpiece 15 is wide, the movable handle 13 can enable the polishing mechanism fixing rod 5 to swing left and right, so that the effect of polishing the whole arc surface is achieved; because the through hole is left between the hinge front support body 39 and the two hinge side support bodies 38, and the driven wheel 3 connected to the driven wheel moving seat 14 is close to the upper part of one side of the baffle 21, the through hole also exists, when the polishing belt 4 needs to be replaced, only the locking nut 34 at the front end of the movable plate needs to be loosened, the movable plate 35 is pulled upwards to detach the polishing belt 4, any other parts do not need to be detached, the polishing belt 4 is very convenient to replace, the polishing belt 4 is a wearing part, and the replacement is needed frequently, a large amount of manpower and material resources are saved by the structure, and meanwhile, the working efficiency is also improved.

The utility model discloses a device of polishing work piece arc surface has easy operation, convenience, labour saving and time saving, low in manufacturing cost is honest and clean, and polishes the high advantage of precision, uses the utility model discloses a but the processing cost of greatly reduced product of device, machining efficiency is high.

Claims

1. The utility model provides a device of polishing work piece arc surface, includes the base and sets up the bearing frame in the base top, its characterized in that: the bearing frame is provided with a lifting unit, the lifting unit comprises a telescopic mechanism connected to the bearing frame and a polishing mechanism fixing rod arranged below the telescopic mechanism, and the telescopic mechanism can drive the polishing mechanism fixing rod to realize lifting action;

2. An apparatus for polishing a circular arc surface of a workpiece according to claim 1, wherein: the base is provided with a workpiece fixing unit, and the workpiece fixing unit comprises more than one rapid clamp and a limiting block.

3. An apparatus for polishing a circular arc surface of a workpiece according to claim 1, wherein: the telescopic mechanism comprises a lifting cylinder and a lifting seat, the lifting cylinder is fixed on the bearing frame, the lifting seat is fixedly connected with a piston rod below the lifting cylinder, lifting seat guide rails are longitudinally and respectively arranged at the positions, corresponding to the lifting seat, of the bearing frame, and the lifting cylinder can drive the lifting seat to move up and down along the lifting seat guide rails.

4. An apparatus for polishing a circular arc surface of a workpiece according to claim 1, wherein: the polishing mechanism is characterized in that a left-right moving unit is arranged below the telescopic mechanism and comprises a polishing mechanism slide rail arranged below the telescopic mechanism, the polishing mechanism slide rail is arranged along the vertical direction of a polishing mechanism fixing rod, and the polishing mechanism fixing rod is movably connected to the polishing mechanism slide rail and can slide along the polishing mechanism slide rail.

5. An apparatus for polishing a circular arc surface of a workpiece according to claim 1, wherein: and a balancing weight is arranged at the tail part of the inner section of the fixed rod of the polishing mechanism.

6. An apparatus for polishing a circular arc surface of a workpiece according to claim 1, wherein: and a handle is arranged at the outer end of the fixed rod of the polishing mechanism.

7. An apparatus for polishing a circular arc surface of a workpiece according to claim 1, wherein: guide wheels B are respectively arranged on two sides of the follow-up pin, the arrangement direction of the guide wheels B is consistent with that of the follow-up pin, the guide wheels B are connected between the front support body and the rear support body of the hinge, and the polishing belt on the guide wheels B penetrates through the lower portion of the support body on the hinge and is in contact with the guide wheels B.

8. An apparatus for polishing a circular arc surface of a workpiece according to claim 1, wherein: hinge side supports are respectively arranged on two sides of the front hinge support and the rear hinge support, the rear hinge support is fixed on the hinge support, the hinge side supports are fixed on the rear hinge support, the front hinge support is fixed on the two hinge side supports, and mutually-communicated holes are reserved among the front hinge support, the hinge side supports and the hinge support.

9. An apparatus for polishing a circular arc surface of a workpiece according to claim 1, wherein: a through hole is formed below the air cylinder connecting seat, and the polishing mechanism fixing rod penetrates through the through hole.