CN218904775U

CN218904775U - Polishing machine for cam shaft cam

Info

Publication number: CN218904775U
Application number: CN202223212726.0U
Authority: CN
Inventors: 陶永文; 刘均
Original assignee: Chongqing Jinqiao Machinery Manufacturing Co ltd
Current assignee: Chongqing Jinqiao Machinery Manufacturing Co ltd
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-04-25
Anticipated expiration: 2032-11-30

Abstract

The utility model relates to the field of cam polishing equipment, and particularly discloses a polishing machine for a cam of a cam shaft. The polishing device comprises a clamping unit and a polishing unit, wherein the polishing unit comprises a polishing frame, a polishing assembly and an abrasive belt assembly, the polishing assembly comprises two polishing headstock, and a telescopic piece is arranged between one ends of the two polishing headstock, which are far away from the polishing head; the abrasive belt assembly comprises an abrasive belt; the polishing device also comprises an adjusting unit, wherein the adjusting unit is connected with the polishing frame; the clamping unit comprises a driving piece and two clamping assemblies, the clamping assemblies comprise ejector pins and a headstock, the ejector pins are arranged on the headstock, and the driving piece is connected with at least one ejector pin and used for driving the ejector pins to rotate. The polishing machine for the cam of the cam shaft can automatically adjust the position of the polishing head when polishing cam shafts of different types, thereby improving the adjusting speed and reducing the adjusting difficulty.

Description

Polishing machine for cam shaft cam

Technical Field

The utility model relates to the field of cam polishing equipment, in particular to a polishing machine for a cam shaft cam.

Background

The automobile cam shaft has higher requirements on the precision excircle on the cam shaft and the roughness of the air distribution cam during production, so that the cam also needs to be polished after being molded. Currently, there is a motorcycle camshaft polishing machine as in application number CN201811341886.0, for polishing a camshaft, where the polishing machine includes a camshaft clamping device, a polishing device, an abrasive belt rack and a winding device, where the camshaft clamping device includes a headstock, a tailstock, a main shaft and a secondary shaft, the headstock and the tailstock are both fixed on a machine tool base, the main shaft and the secondary shaft are coaxially arranged, the main shaft is rotatably mounted on the headstock, a belt pulley is arranged at the outer end of the main shaft, the belt pulley is driven by a motor, tips for tightly supporting and positioning the camshaft are arranged at the inner ends of the main shaft and the secondary shaft, the main shaft drives the camshaft to rotate through a key block or a pin, and the secondary shaft is rotatably and axially slidably mounted on the tailstock; the polishing device comprises an axial swinging sliding table, a polishing vertical frame and a polishing assembly arranged on the polishing vertical frame, wherein the axial swinging sliding table is slidably arranged on a machine tool base, a driving assembly for driving the axial swinging sliding table to slide reciprocally is arranged on the machine tool base, and the polishing assembly comprises a polishing arm, a polishing head, a clamping cylinder, an abrasive belt guide wheel and an abrasive belt retracting device; the polishing arms are arranged in an upper mode and a lower mode, the middle portions of the two polishing arms are respectively and rotatably arranged on the polishing vertical frame through transverse rotating shafts, one end, close to the camshaft clamping device, of each polishing arm is provided with a polishing head, the two polishing heads are opposite up and down, and the polishing heads are rotatably connected with the corresponding polishing arms; the abrasive belt retraction device is arranged on the polishing vertical frame and used for adjusting the tension of the abrasive belt, the abrasive belt retraction device comprises a sliding seat, a push rod, a connecting rod, a retraction spring and a retraction guide wheel, the push rod extends towards the clamping cylinder, the extension end of the push rod is connected with the upper polishing arm and the lower polishing arm through the upper connecting rod and the lower connecting rod, the retraction rod extends between the upper polishing head and the lower polishing head, the retraction guide wheel is arranged at the extension end of the retraction rod, and the retraction spring is sleeved on the retraction rod and supported on the sliding seat and used for resetting the retraction rod.

When the polishing machine is used, two opposite polishing heads and the abrasive belt arranged between the two polishing heads can only polish one cam, and the polishing machine discloses a plurality of polishing devices which correspond to the cams one by one so as to polish the cams respectively. However, when the cam polishing device is actually used, the number, the width and the positions of cams on camshafts of different types are different, when the camshafts of other types are required to be polished, the positions of the polishing devices are required to be adjusted to ensure that the plurality of polishing devices correspond to the cams on the camshafts of other types one by one, the polishing devices are complex in structure, special technicians are required to adjust the polishing devices, the adjustment time is long, the position of the polishing devices is required to be measured repeatedly during adjustment, and the polishing devices can be accurately opposite to the cams after the adjustment is completed, so that the workload of adjustment is large.

Disclosure of Invention

The utility model aims to provide a polishing machine for cam shafts, which is used for automatically adjusting the position of a polishing head when polishing cam shafts of different types, improving the adjusting speed and reducing the adjusting difficulty.

In order to achieve the above purpose, the utility model adopts the following technical scheme: the polishing machine comprises a clamping unit and a plurality of polishing units, wherein each polishing unit comprises a polishing frame, a polishing assembly and an abrasive belt assembly, each polishing assembly comprises two polishing head frames, each polishing head frame is hinged with each polishing frame, one end of each polishing head frame is a polishing head, a telescopic piece is arranged between one ends of the two polishing head frames, which are far away from each polishing head, and two ends of each telescopic piece are hinged with the corresponding polishing head frame respectively and are used for driving the corresponding polishing head frame to swing; the abrasive belt assembly comprises an abrasive belt which is tensioned between two polishing heads; the polishing unit further comprises an adjusting unit, and the adjusting unit is connected with the polishing frame and used for driving the polishing frame to move along the horizontal direction;

the clamping unit comprises a driving piece and two clamping assemblies, the two clamping assemblies are respectively positioned on two sides of the polishing unit, each clamping assembly comprises a thimble and a headstock, the thimble is arranged on the headstock, and the driving piece is connected with at least one thimble and used for driving the thimble to rotate.

The beneficial effect of this scheme is:

the polishing device is provided with the adjusting unit, the adjusting unit can drive the polishing frame to move along the axial direction of the thimble, and the position of the polishing frame is changed. The transmission shaft is clamped between the ejector pins of the two clamping assemblies, so that when the polishing frame moves along the axial direction of the ejector pins, the polishing frame moves along the axial direction of the transmission shaft at the same time, so that the polishing head frame is aligned with different positions of the transmission shaft, when the transmission shafts of different types are polished, even if the positions of the cams change, the polishing heads and the cams are in one-to-one correspondence, and special technicians are not required to be adopted for adjustment, and the polishing head and the cams are easy to operate and faster in adjustment speed.

Further, a base is arranged below the polishing frame and is connected with a reciprocating pushing piece, and the reciprocating pushing piece is used for pushing the base to slide along the radial direction of the thimble; the polishing frame is mounted on the base.

The beneficial effect of this scheme is: during polishing, the base is pushed to move by the reciprocating pushing piece to enable the polishing frame on the base to move along with the base, the polishing head frame is driven to be close to the transmission shaft, the abrasive belt is close to the cam at the moment, when the polishing head is used in actual use, the copper drum controls the moving distance of the base to enable the two ends of the base, which are close to the two polishing heads, to be respectively moved to the upper side and the lower side of the cam, and the position, which is opposite to the cam, of the abrasive belt is limited by the cam, so that the abrasive belt can be bent into a C shape, and compared with a vertical abrasive belt, the contact area between the abrasive belt and the cam can be increased, and the polishing speed of the cam is improved.

Secondly, before the base moves, the distance between the abrasive belt and the installation position of the transmission shaft is larger, the installation of the transmission shaft is not limited by the abrasive belt, and the installation is convenient.

Further, the base and the reciprocating pushing piece are all provided with a plurality of, and the base corresponds to the polishing frame one by one.

The beneficial effect of this scheme is: each base can move respectively, so that when the cams and the cam shafts are required to be polished simultaneously, any polishing head frame can be independently adjusted, the fact that the abrasive belt and the cams or the cam shafts to be polished keep certain pressure and larger contact area is ensured, and the polishing efficiency is further improved.

Further, the belt assembly includes a lock block and a hold down member opposite the lock block, with the belt passing between the lock block and the hold down member.

The beneficial effect of this scheme is: can press the abrasive band on the locking piece through unloading piece, fix a position the abrasive band, in polishing process, avoid the abrasive band to shift to make and keep certain pressure between abrasive band and the cam, improve polishing effect.

Further, the locking piece is equipped with V type groove towards the one end of pushing down the piece, and the pushing down the piece is connected with the briquetting opposite with V type groove.

The beneficial effect of this scheme is: the pressing block can increase the contact area with the abrasive belt after pressing the abrasive belt in the V-shaped groove, thereby improving the positioning effect on the abrasive belt and further avoiding the displacement of the abrasive belt.

Further, the abrasive belt assembly comprises an upper rolling wheel and a lower rolling wheel, the upper rolling wheel and the lower rolling wheel are both connected with rotating parts, the rotating parts are used for driving the upper rolling wheel and the lower rolling wheel to rotate, and two ends of the abrasive belt are respectively connected with the upper rolling wheel and the lower rolling wheel.

The beneficial effect of this scheme is: the abrasive belt can move relative to the polishing head through the upper winding wheel and the lower winding wheel, so that after the position of the abrasive belt, which is opposite to the cam, is worn, the position which is not worn can be moved to the position opposite to the cam by moving the abrasive belt, and the polishing effect is improved.

Further, the adjusting unit comprises an adjusting motor, a screw rod, a guide rod and a nut seat, wherein the guide rod and the screw rod penetrate through the nut seat, the nut seat is in sliding fit with the guide rod, the screw rod and the nut seat form a ball screw structure, the adjusting motor is connected with the screw rod and used for driving the screw rod to rotate, and the nut seat is used for driving the polishing frame to axially move along the screw rod.

The beneficial effect of this scheme is: the screw rod is rotated to enable the nut seat to move, so that the base is driven to move, and the moving precision of the base in the scheme is larger.

Further, the nut seat is provided with a connecting piece which is detachably connected with the polishing frame.

The beneficial effect of this scheme is: because the nut seat is detachably connected with the polishing frames, the positions of all the polishing frames can be adjusted by only arranging one adjusting unit and connecting the nut seat with all the polishing frames one by one, so that the polishing machine in the scheme has simpler structure.

Further, a positioning block is arranged on the polishing frame, and a spring is arranged between the positioning block and the polishing frame; a locking shaft is arranged at the lateral direction of the polishing frame, and the positioning block is clamped with the locking shaft; the connecting piece and the positioning block are respectively positioned at two sides of the locking shaft, and the connecting piece can push the positioning block to one side far away from the locking shaft.

The beneficial effect of this scheme is: after the polishing frame is adjusted to a preset position, the polishing frame can be positioned through the connection of the positioning block and the locking shaft, so that the polishing frame cannot move along the axial direction of the transmission shaft in the use process, the abrasive belt is further ensured to be aligned with the position to be polished, and the polishing precision is improved. And the connecting piece is opposite to the positioning block, and when the connecting piece is connected with the polishing frame, the connecting piece pushes the positioning block to one side far away from the locking shaft at the same time, so that the polishing frame is separated from the locking shaft, and the positioning of the polishing frame is released.

Further, the clamping unit further comprises a sliding rail and a propping piece, the sliding rail is located below the headstock, the headstock is in sliding fit with the sliding rail, and the propping piece is connected with the headstock and used for pushing the headstock to slide.

The beneficial effect of this scheme is: the ejector pin can be adjusted by pushing the headstock to move through the ejector pin, and the transmission shaft is arranged between the two ejector pins, so that the position of the transmission shaft after being arranged can be changed after the ejector pin moves, the position of the cam is changed, and the cam is ensured to be opposite to the abrasive belt.

Drawings

FIG. 1 is a front view of embodiment 1 of the present utility model;

FIG. 2 is a view in the direction A of FIG. 1;

fig. 3 is an enlarged view at B in fig. 2.

Detailed Description

The following is a further detailed description of the embodiments:

reference numerals in the drawings of the specification include: slide rail 1, headstock 2, thimble 21, top tight piece 22, connecting seat 3, reciprocal impeller 31, base 4, polishing frame 5, lead screw 51, polishing headstock 6, expansion piece 61, abrasive band 7, locking piece 8, V type groove 81, pushing piece 9, briquetting 91.

Example 1

The utility model provides a burnishing machine for camshaft cam, as shown in fig. 1, includes frame, clamping unit, a plurality of polishing units and a plurality of adjustment unit, and the clamping unit includes driving piece, slide rail 1, two jack-up pieces 22 and two clamping components, and slide rail 1 passes through bolt horizontal installation in the frame. The clamping assembly comprises a thimble 21 and a headstock 2, the headstock 2 is arranged on the sliding rail 1 and slides along the sliding rail 1, two propping pieces 22 are respectively connected with the two headstock 2 through flange plates, and the propping pieces 22 are arranged on the frame through screws and used for driving the headstock 2 to slide along the sliding rail 1. The thimble 21 is mounted on the top of the headstock 2, and the structure and mounting manner of the thimble 21 in this embodiment are the same as those in the prior art and will not be described again. The two driving parts are motors and are respectively connected with the two ejector pins 21 through couplings and used for driving the ejector pins 21 to rotate.

The polishing unit is located the rear side of slide rail 1 and distributes in proper order along the length direction of slide rail 1, and as shown in fig. 2 and 3, the polishing unit includes polishing frame 5, polishing subassembly, abrasive band 7 subassembly and adjustment unit, and the below of every polishing frame 5 all is equipped with base 4, and the left side of base 4 is equipped with reciprocal impeller 31, and reciprocal impeller 31 passes through the ring flange to be connected with base 4 for promote the reciprocal slip of base 4 group side to side, polishing frame 5 passes through the screw and installs on base 4. The base 4 in this embodiment is equipped with connecting seat 3 below, and reciprocal impeller 31 passes through the screw to be installed on connecting seat 3, and the top of connecting seat 3 is equipped with the track, and base 4 only with connecting seat 3 side-to-side sliding connection under orbital effect, connecting seat 3 passes through the screw to be installed in the frame.

The polishing assembly comprises two polishing head frames 6, the middle part of each polishing head frame 6 is hinged with each polishing frame 5, the right end of each polishing head frame 6 is a polishing head, the polishing heads are positioned between two ejector pins 21, and guide wheels are arranged on the polishing heads. A telescopic piece 61 is arranged between the left ends of the two polishing headstock 6, the jacking piece 22, the reciprocating pushing piece 31 and the telescopic piece 61 in the embodiment are all cylinders, the push rod of the telescopic piece 61 and one end far away from the push rod are respectively hinged with the left ends of the two polishing headstock 6, and when the push rod of the telescopic piece 61 extends and retracts, the two polishing headstock 6 are driven to swing.

The adjusting unit corresponds to the polishing unit one by one, and comprises an adjusting motor, a screw rod 51, a guide rod and a nut seat, wherein the screw rod 51 is connected with the frame through a bearing, the adjusting motor is installed on the base 4 through a screw and connected with the screw rod 51 through a coupler and used for driving the screw rod 51 to rotate, the screw rod 51 and the nut seat form a ball screw rod 51 structure, the guide rod penetrates through the nut seat and is installed on the base 4 through a screw, and a hydraulic cylinder or an air cylinder can be used as the adjusting unit in practical implementation, and a push rod of the hydraulic cylinder or the air cylinder is connected with the nut seat and used for pushing the nut seat to move.

The abrasive belt 7 assembly comprises an abrasive belt 7, an upper rolling wheel, a lower rolling wheel, a locking block 8 and a lower pressing piece 9, wherein the upper rolling wheel and the lower rolling wheel are all installed on the polishing frame 5 through bearings and are all connected with rolling motors, the rolling motors above adopt motors without locking functions, and the motors below adopt motors with locking functions. The upper winding wheel is positioned above the two polishing head frames 6, the lower winding wheel is positioned below the polishing frame 5, two ends of the abrasive belt 7 are respectively wound on the upper winding wheel and the lower winding wheel, and the abrasive belt 7 bypasses the guide wheels at the right ends of the two polishing heads.

The locking piece 8 is located above the uppermost polishing head frame 6, the top of the locking piece 8 is provided with a VV type groove 81 with an upward opening, the lower pressing piece 9 is located above the locking piece 8, the locking piece 8 and the lower pressing piece 9 in this embodiment are both mounted on the polishing frame 5 through bolts, the lower pressing piece 9 also adopts an air cylinder, and a hydraulic cylinder or a linear driver can be adopted in practical implementation. The push rod of the hold-down piece 9 faces downwards, the push rod is connected with a pressing block 91 through a flange, the lower end of the pressing block 91 is in a V shape identical to the shape of the VV-shaped groove 81, and the pressing block is used for pressing the abrasive belt 7 on the VV-shaped groove 81 to position the abrasive belt 7.

The specific implementation process is as follows:

before polishing, one headstock 2 is manually moved to a side far away from the other headstock 2 through a jacking piece 22, then a transmission shaft is transversely placed between two ejector pins 21, the headstock 2 is reset, and the transmission shaft is positioned through the two ejector pins 21.

When polishing, the driving piece is started to drive the thimble 21 to rotate so as to drive the transmission shaft to rotate. The push rod of the telescopic rod is then controlled to retract, so that the polishing head frame 6 swings, and the distance between the two polishing heads increases. And start the reciprocal pusher 31, push the base 4 rightwards, make two polishing heads move to the position above the cam to be polished and lower than the cam separately, the position that the abrasive band 7 is located in the middle of two polishing heads is curved into C-shape because of being blocked by the cam, then control the push rod of the telescopic member 61 to stretch out, make two polishing heads close to the cam, increase the contact area of the cam and pressure between abrasive band 7 and cam, raise polishing effect and speed. The presser 9 is then used to slide the presser 91 downwards, pressing the sanding belt 7 into the VV-type groove 81, positioning the sanding belt 7 so that the sanding belt 7 will not loosen during use.

After polishing is completed, the driving member is closed, the polishing heads are controlled to reset through the reciprocating pushing member 31, meanwhile, the pressing block 91 is reset through the pressing piece 9, the abrasive belt 7 is loosened, the abrasive belt 7 is wound through the winding motor above, and the abrasive belt 7 is tensioned between the two polishing heads. Finally, the head frame 2 is slid to a side far away from the other head frame 2 through the propping piece 22, the transmission shaft is loosened, and the transmission shaft is manually taken down from between the two ejector pins 21, so that polishing of one transmission shaft is completed.

When the transmission shafts of different types are polished, the position of the polishing frame 5 is required to be adjusted according to the transmission shafts of different types, the adjusting motor is started, the adjusting motor controls the screw rod 51 to rotate, the nut pair moves along the axial direction of the screw rod 51, the polishing frame 5 moves along with the screw rod, and when the polishing frame 5 moves to the position where the abrasive belt 7 is aligned with the cam, the adjusting motor is closed, so that the adjustment of the polishing head is rapidly completed.

Example 2

On the basis of embodiment 1, only one adjusting unit is provided in this embodiment, and the adjusting motor, the guide rod and the screw 51 are all mounted on the frame. The connecting piece is arranged on the nut seat of the adjusting unit, the connecting piece in the embodiment adopts an air cylinder, the push rod of the connecting piece is transversely arranged, the push rod of the connecting piece is connected with a reset clamping groove block through a flange plate, and the connecting piece can also adopt a hydraulic cylinder and a linear driver in actual implementation. The polishing frame 5 is provided with a groove opposite to the reset clamping groove block, an opening of the groove faces the reset clamping groove block, a positioning block is slidably arranged in the groove, a spring is arranged on the right side of the positioning block, and two ends of the spring are respectively abutted against the positioning block and the side wall of the groove and used for enabling the positioning block to slide out of the groove. A locking shaft is transversely arranged between the positioning block and the reset clamping groove block, two ends of the locking shaft are mounted on the frame through screws, the reset clamping groove block and the positioning block are respectively located on the left side and the right side of the locking block 8, the positioning block and the reset clamping groove block in the embodiment are U-shaped, and openings of the positioning block and the reset clamping groove block face the locking shaft. The locking shaft is axially provided with a plurality of annular grooves, and the positioning block is clamped with the annular grooves; the width of the opening of the reset clamping groove block is larger than the diameter of the locking shaft, and the reset clamping groove block can be in sliding fit with the groove after sliding rightwards.

In this embodiment, when the position of the polishing frame 5 needs to be adjusted, the adjusting motor is started first, so that the nut group moves to a position where the reset clamping groove block is opposite to the positioning block on the polishing frame 5 to be adjusted, the adjusting motor is closed, then the connecting piece is started, so that the push rod of the connecting piece extends out, the reset clamping groove block is pushed to the right until the right end of the reset clamping groove block slides into the groove, at the moment, the reset clamping groove block pushes the positioning block into the groove at the same time, and the locking shaft does not position the polishing frame 5 any more. And then starting the adjusting motor to enable the nut seat to move along the axial direction of the transmission shaft, closing the adjusting motor until the polishing frame 5 is moved to a preset position, controlling the push rod of the connecting piece to retract, enabling the reset clamping groove block to loosen the positioning block, enabling the positioning block to slide leftwards under the action of the spring, clamping with the annular groove on the locking shaft, and positioning the polishing frame 5 again by the locking shaft. When another polishing frame 5 needs to be adjusted, the adjusting motor is started to align the nut seat with the other polishing frame 5, and the adjusting unit can be used for adjusting after the steps are repeated, so that a plurality of adjusting units are not needed to be arranged, and the polishing machine in the embodiment is simpler in structure.

The foregoing is merely exemplary of the present utility model, and specific technical solutions and/or features that are well known in the art have not been described in detail herein. It should be noted that, for those skilled in the art, several variations and modifications can be made without departing from the technical solution of the present utility model, and these should also be regarded as the protection scope of the present utility model, which does not affect the effect of the implementation of the present utility model and the practical applicability of the patent. The protection scope of the present application shall be subject to the content of the claims, and the description of the specific embodiments and the like in the specification can be used for explaining the content of the claims.

Claims

1. A burnishing machine for camshaft cam, includes clamping unit and a plurality of polishing unit, polishing unit includes polishing frame, polishing subassembly and abrasive band subassembly, polishing subassembly includes two polishing headstock, its characterized in that: the two polishing head frames are hinged with the polishing frame, one ends of the two polishing head frames are polishing heads, a telescopic piece is arranged between one ends of the two polishing head frames, which are far away from the polishing heads, and two ends of the telescopic piece are respectively hinged with the two polishing head frames and are used for driving the polishing head frames to swing; the belt assembly comprises a belt that is tensioned between two polishing heads; the polishing device also comprises an adjusting unit, wherein the adjusting unit is connected with the polishing frame and is used for driving the polishing frame to move along the horizontal direction;

2. A polishing machine for a camshaft cam according to claim 1, wherein: a base is arranged below the polishing frame and is connected with a reciprocating pushing piece, and the reciprocating pushing piece is used for pushing the base to slide along the radial direction of the thimble; the polishing frame is mounted on the base.

3. A polishing machine for a camshaft cam according to claim 2, wherein: the base and the reciprocating pushing piece are all provided with a plurality of, and the base corresponds to the polishing frame one by one.

4. A polishing machine for a camshaft cam according to claim 1, wherein: the belt assembly includes a lock block and a hold down member opposite the lock block, with the belt passing between the lock block and the hold down member.

5. A polishing machine for a camshaft cam according to claim 4, wherein: the locking piece is equipped with V type groove towards the one end of pushing down the piece, the pushing down the piece be connected with the briquetting that V type groove is relative.

6. A polishing machine for a camshaft cam according to claim 1, wherein: the abrasive belt assembly comprises an upper winding wheel and a lower winding wheel, the upper winding wheel and the lower winding wheel are both connected with rotating parts, the rotating parts are used for driving the upper winding wheel and the lower winding wheel to rotate, and two ends of the abrasive belt are respectively connected with the upper winding wheel and the lower winding wheel.

7. A polishing machine for a camshaft cam according to claim 1, wherein: the adjusting unit comprises an adjusting motor, a screw rod, a guide rod and a nut seat, wherein the guide rod and the screw rod penetrate through the nut seat, the nut seat is in sliding fit with the guide rod, the screw rod and the nut seat form a ball screw structure, the adjusting motor is connected with the screw rod and used for driving the screw rod to rotate, and the nut seat is used for driving the polishing frame to axially move along the screw rod.

8. A polishing machine for a camshaft cam according to claim 7, wherein: the nut seat is provided with a connecting piece which is detachably connected with the polishing frame.

9. A polishing machine for a camshaft cam according to claim 8, wherein: a positioning block is arranged on the polishing frame, and a spring is arranged between the positioning block and the polishing frame; a locking shaft is arranged in the lateral direction of the polishing frame, and the positioning block is clamped with the locking shaft; the connecting piece and the positioning block are respectively positioned at two sides of the locking shaft, and the connecting piece can push the positioning block to one side far away from the locking shaft.

10. A polishing machine for a camshaft cam according to claim 1, wherein: the clamping unit further comprises a sliding rail and a propping piece, the sliding rail is located below the headstock, the headstock is in sliding fit with the sliding rail, and the propping piece is connected with the headstock and used for pushing the headstock to slide.