CN210849757U

CN210849757U - Automatic grinding machine tool

Info

Publication number: CN210849757U
Application number: CN201921320101.1U
Authority: CN
Inventors: 钱南安
Original assignee: Linhai City Weite Machinery Co ltd
Current assignee: Linhai City Weite Machinery Co ltd
Priority date: 2019-08-15
Filing date: 2019-08-15
Publication date: 2020-06-26
Anticipated expiration: 2029-08-15

Abstract

The utility model belongs to the technical field of machinery, a automatic grinding lathe is related to, it has solved current lathe intensity of labour big, machining efficiency low grade technical problem. The grinding machine comprises a frame, a material box, a rotating mechanism, a bracket, a grinding mechanism and a discharging disc; the material box is obliquely arranged on the rack, and the lower end of the material box is provided with a discharge hole for a workpiece to pass through; the rotating mechanism is arranged on the rack and can drive the workpiece to rotate; the bracket is movably arranged on the rack and can convey the workpiece at the discharge port of the material box to the rotating mechanism; the grinding mechanism is arranged on the frame and can grind the end part of the workpiece; the discharge tray is arranged on the rack and located below the bracket, and the bracket can convey the workpiece which is finished by grinding to the discharge tray. The utility model has the advantages of low operation labor intensity, high processing efficiency and the like.

Description

Automatic grinding machine tool

Technical Field

The utility model belongs to the technical field of machinery, a automatic grinding lathe is related to.

Background

In the prior art, the grinding machine is used for grinding the end shapes of shaft parts, such as the end parts of a spindle blade and the like, in bevel grinding and tip circular arc machining, the grinding machine is usually used for grinding, the grinding machine in the prior art needs to manually charge and discharge materials, and the turntable is manually pushed to realize machining, so that the labor intensity is high, and the machining efficiency is low.

Disclosure of Invention

The utility model aims at having the above-mentioned problem to current technique, provided an automatic grinding lathe, the utility model aims to solve the technical problem that: how to reduce the labor intensity and improve the processing efficiency.

The purpose of the utility model can be realized by the following technical proposal:

an automatic grinding machine, characterized in that the grinding machine comprises:

a frame;

the material box is obliquely arranged on the rack, and a discharge hole for a workpiece to pass through is formed in the lower end of the material box;

the rotating mechanism is arranged on the rack and can drive the workpiece to rotate;

the bracket is movably arranged on the rack and can convey the workpiece at the discharge port of the material box to the rotating mechanism;

the grinding mechanism is arranged on the rack and can grind the end part of the workpiece;

the discharging tray is arranged on the rack and located below the bracket, and the bracket can convey the workpiece which is finished by grinding to the discharging tray.

The working principle is as follows: when the grinding machine tool is used, a workpiece can roll down to the discharge opening under the action of gravity, the bracket moves the workpiece to the rotating mechanism from the discharge opening, the transferring mechanism drives the workpiece to rotate, meanwhile, the grinding mechanism grinds the end part of the workpiece, the rotating workpiece can ensure that all parts of the end part of the workpiece are ground and sharpened, and after the grinding is finished, the bracket moves the workpiece after the grinding is finished to the discharge disc, so that the whole grinding process is completed. Compared with the prior art, the grinding machine tool can automatically complete feeding, grinding and material returning, effectively reduce the labor intensity of workers, improve the processing efficiency, has higher processing precision and effectively improves the product quality.

In the automatic grinding machine tool, the rack is provided with a linear driving source, the output end of the linear driving source faces the rotating mechanism, the bracket is positioned below the material box and fixed on the output end of the linear driving source, and the bracket is also provided with a groove for bearing a workpiece. During feeding, the linear driving source drives the bracket to move to the discharge port of the material box, and the workpiece falls into the groove of the bracket from the discharge port; the linear driving source moves to drive the bracket to move, so that the workpiece moves to the rotating mechanism.

In the automatic grinding machine tool, the groove is obliquely arranged, and the rear end of the groove is higher than the front end of the groove; the bracket is also provided with a front roller and a rear roller which correspond to the grooves, the front roller is close to the rotating mechanism, the rear roller is close to the material box and higher than the front roller, and the side surface of the workpiece can be simultaneously contacted with the wheel surface of the front roller and the wheel surface of the rear roller. Because the workpiece needs to rotate during grinding, the front roller and the rear roller are in contact with the workpiece and can rotate in a matched manner.

In the automatic grinding machine tool, the material box comprises a bottom plate, a side plate and a baffle plate, the bottom plate and the side plate are fixed, the baffle plate is fixed at the lower end of the side plate, and the baffle plate and the bottom plate are arranged at intervals to form the discharge hole; the grinding machine tool further comprises a movable plate, the upper end of the movable plate is hinged to the outer plate surface of the baffle, the hinge point of the movable plate and the hinge point of the movable plate are higher than the lower edge of the baffle, and when a workpiece is placed on the bracket, the workpiece can be in contact with the movable plate. When the workpiece is contacted with the movable plate, the rear end of the groove is higher than the front end, so that the workpiece can be driven to overcome the resistance generated by the movable plate, the movable plate swings, and the workpiece is smoothly conveyed to the rotating mechanism; when blanking is carried out, the machined workpiece moves towards the direction of the material box under the action of the linear driving source, the workpiece is contacted with the outer plate surface of the movable plate, the hinge point of the movable plate and the baffle is higher than the lower edge of the baffle, so that the movable plate cannot swing, the workpiece falls under the blocking action of the movable plate, and blanking is realized.

In an automatic grinding machine of foretell, slewing mechanism includes rotary drive source one, drive belt and tensioning support, rotary drive source one is fixed in on the frame, the one end of drive belt is connected with rotary drive source one's output, the other end of drive belt twine in on the tensioning support, and can contact with the work piece. The rotary driving source rotates to drive the transmission belt to rotate, so that the workpiece contacted with the transmission belt is driven to rotate to be matched with grinding.

In foretell an automatic grinding machine, be fixed with the action wheel on the output of rotary drive source one, the rotation is provided with on the tensioning support two with the action wheel is corresponding from the driving wheel, the drive belt twines in proper order on action wheel and follow driving wheel, and the work piece can contact with the partial drive belt that is located two between the driving wheel. The bracket drives the workpiece to move towards the rotating mechanism until the workpiece is contacted with part of the transmission belt between the two driven wheels, and the first rotary driving source rotates to drive the workpiece to rotate through the transmission belt.

In the automatic grinding machine tool, the grinding mechanism comprises a rotary platform arranged on the rack, a cross guide rail is arranged on the rotary platform, a second rotary driving source is arranged on the cross guide rail in a sliding mode, and an output end of the second rotary driving source is connected with a grinding wheel which can be in contact with the end portion of a workpiece on the bracket. The grinding wheel can move forward and backward, left and right and rotate by a rotation angle relative to the workpiece under the action of the rotary platform and the cross guide rail so as to control the size of the abnormal shape, the angle and the end face radius of the end part of the grinding workpiece.

In the automatic grinding machine tool, the rotary platform is further provided with a dressing tool rest, and the dressing tool rest is provided with a dressing blade capable of contacting with a grinding wheel. When the grinding wheel becomes dull, the rotary driving source II can be driven to move through the cross guide rail, so that the end face of the grinding wheel is in contact with the trimming blade, and the trimming blade can polish and trim the rotating grinding wheel.

In the automatic grinding machine tool, the axis of the grinding wheel and the axis of the workpiece on the bracket are crossed to form an included angle, one end of the workpiece on the bracket can be in contact with the grinding wheel, the rack is provided with a limiting piece which can be in contact with the other end of the workpiece on the bracket, and the point of the limiting piece in contact with the workpiece on the bracket can move along the length direction of the workpiece. When a workpiece is ground, one end of the workpiece is in contact with the grinding wheel, the other end of the workpiece is in contact with the limiting piece, the side face of the workpiece is in contact with the front roller, the rear roller and the transmission belt, so that positioning is completed, the grinding wheel can grind one end of the workpiece, and the position of the contact point of the limiting piece and the workpiece can be adjusted and moved according to different processing requirements, so that different processing and grinding requirements are met.

In the automatic grinding machine tool, the limiting piece is made of elastic metal, one end of the limiting piece is fixed on the rack, the other end of the limiting piece is arranged in a suspension mode, the outer surface of the limiting piece can be in contact with the other end of the workpiece on the bracket, the rack is further provided with a sliding rod capable of moving along the axial direction of the workpiece on the bracket, and the end portion of the sliding rod is attached to the inner surface of the limiting piece. The limiting piece can be driven to swing through the movement of the sliding rod, so that the workpiece on the bracket is driven to move, and the grinding is adjusted.

In the automatic grinding machine tool, the grinding machine tool further comprises a cooling system, the cooling system comprises a water tank, a water pump, a pipeline and a nozzle, the water tank is fixed on the rack, one end of the water pump is communicated with the water tank, the other end of the water pump is communicated with the nozzle through the pipeline, and the nozzle is aligned to the grinding position of the grinding wheel; a water accumulating groove located below the grinding position is formed in the frame, and a water return flow channel is arranged between the water accumulating groove and the water pool. The grinding wheel and the workpiece can generate heat after being ground for a long time, so that the grinding position can be cooled through the cooling system, when the grinding wheel and the workpiece are used specifically, cooling water in the water tank can be pumped out by the water pump and sprayed to the grinding position through the pipeline and the nozzle, and sprayed water can flow back to the water tank through the water collecting tank and the water return flow channel to be recycled.

In the automatic grinding machine tool, the grinding machine tool further comprises a control system, and the control system is connected with the linear driving source, the first rotary driving source, the rotary platform, the cross guide rail, the second rotary driving source and the water pump. After the control system is designed, the control system can be combined with each driving source to control the actions of the driving sources to be matched with each other, for example, the feeding and retracting, the compensation of the feeding amount, the change of stations, the compensation of the feeding amount after the grinding wheel is trimmed and the like are combined with each other to form an automatic processing system, so that the labor intensity is reduced, and the production efficiency is improved.

Compared with the prior art, the utility model has the advantages of it is following:

the feeding, grinding and material returning of the grinding machine tool can be automatically completed, the labor intensity of workers can be effectively reduced, the machining efficiency is improved, the machining precision is higher, and the product quality is effectively improved.

Drawings

Fig. 1 is a schematic structural view of the automatic grinding machine.

Fig. 2 is a schematic structural view of the present cartridge.

Fig. 3 is a schematic structural view of the bracket and the rotating mechanism.

Fig. 4 is a schematic structural view of the grinding mechanism.

Fig. 5 is a schematic configuration diagram of the cooling system.

Fig. 6 is a schematic configuration diagram of the control system.

Fig. 7 is an operational diagram of the automatic grinding machine.

In the figure, 1, a frame; 2. a magazine; 3. a rotating mechanism; 4. a bracket; 5. a grinding mechanism; 6. a discharging tray; 7. a linear drive source; 8. a groove; 9. a front roller; 10. a rear roller; 11. a base plate; 12. a side plate; 13. a baffle plate; 14. a movable plate; 15. a first rotary driving source; 16. a transmission belt; 17. tensioning the bracket; 18. a driving wheel; 19. a driven wheel; 20. rotating the platform; 21. a cross guide rail; 22. a second rotary driving source; 23. a grinding wheel; 24. trimming a tool rest; 25. trimming the blade; 26. a limiting sheet; 27. a slide bar; 28. a cooling system; 29. a pool; 30. a water pump; 31. a pipeline; 32. a nozzle; 33. a water accumulation tank; 34. a return water channel; 35. a control system; 36. and (5) a workpiece.

Detailed Description

The following are specific embodiments of the present invention and the accompanying drawings are used to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

As shown in fig. 1, the grinding machine comprises a frame 1, a material box 2, a rotating mechanism 3, a bracket 4, a grinding mechanism 5 and a discharging disc 6; the material box 2 is obliquely arranged on the rack 1, and the lower end of the material box 2 is provided with a discharge hole for a workpiece 36 to pass through; the rotating mechanism 3 is arranged on the frame 1 and can drive the workpiece 36 to rotate; the bracket 4 is movably arranged on the frame 1 and can convey the workpiece 36 at the discharge port of the material box 2 to the rotating mechanism 3; the grinding mechanism 5 is arranged on the frame 1 and can grind the end part of the workpiece 36; the discharging tray 6 is arranged on the frame 1 and located below the bracket 4, and the bracket 4 can convey the ground workpiece 36 to the discharging tray 6.

Specifically, as shown in fig. 1 and 3, in order to realize feeding and discharging, the frame 1 is provided with a linear drive source 7, an output end of the linear drive source 7 faces the rotating mechanism 3, the bracket 4 is positioned below the magazine 2 and fixed to the output end of the linear drive source 7, and the bracket 4 is further provided with a groove 8 for receiving the workpiece 36. In the present embodiment, the linear drive source 7 is preferably an air cylinder, and various drive sources such as an oil cylinder and a linear motor may be used.

Preferably, the groove 8 in the present embodiment is obliquely arranged, and the rear end of the groove 8 is higher than the front end of the groove 8; the bracket 4 is also provided with a front roller 9 and a rear roller 10 corresponding to the groove 8, the front roller 9 is close to the rotating mechanism 3, the rear roller 10 is close to the material box 2 and higher than the front roller 9, and the side surface of the workpiece 36 can be simultaneously contacted with the wheel surface of the front roller 9 and the wheel surface of the rear roller 10.

It should be noted that there are two grooves 8 in the present embodiment, but the specific number is not limited as long as the workpiece 36 can be held. The shape of the groove 8 is preferably arc-shaped, but other schemes such as V-shaped can be adopted.

As shown in fig. 1 and 2, in order to cooperate with the bracket 3 to perform feeding and discharging, the material box 2 comprises a bottom plate 11, a side plate 12 and a baffle plate 13, wherein the bottom plate 11 and the side plate 12 are fixed, and the baffle plate 13 is fixed at the lower end of the side plate 12 and is arranged at a distance from the bottom plate 11 to form a discharge hole; the grinding machine further comprises a movable plate 14, the upper end of the movable plate 14 is hinged on the outer plate surface of the baffle 13, the hinge point of the movable plate 14 and the baffle 13 is higher than the lower edge of the baffle 13, and the workpiece 36 can be in contact with the movable plate 14 when the workpiece 36 is placed on the bracket 4. In order to ensure that the movable plate 14 is resettable, a spring is also provided between the movable plate 14 and the flap 13 in the present embodiment.

It should be noted that the movable plate 14 in the present embodiment and the drawings described herein is preferably in the form of a hinge, which is convenient for installation and may be a standard part on the market. Alternatively, the movable plate 14 may be a non-hinged movable plate, such as a single plate. The number of the movable plates 14 is preferably two, and alternatively, a single movable plate or a plurality of movable plates may be selected.

As shown in fig. 3, the turning mechanism 3 includes a first rotary driving source 15, a transmission belt 16 and a tension bracket 17, the first rotary driving source 15 is fixed on the frame 1, one end of the transmission belt 16 is connected with the output end of the first rotary driving source 15, and the other end of the transmission belt 16 is wound on the tension bracket 17 and can contact with the workpiece 36.

In this embodiment, a driving wheel 18 is fixed at an output end of the first rotary driving source 15, two driven wheels 19 corresponding to the driving wheel 18 are rotatably disposed on the tension bracket 17, the driving belt 16 is sequentially wound around the driving wheel 18 and the driven wheels 19, and the workpiece 36 can contact with a portion of the driving belt 16 located between the two driven wheels 19.

In operation, the workpiece 36 is positioned between the front roller 9 and the rear roller 10 of the carriage 4 and contacts the belt 16 of the turning mechanism 3, and is turned by the belt 16. The purpose of the rear roller 10 being higher than the front roller 9 is to ensure that the workpiece 36 can rotate against the drive belt 16, since the transmission between the two is achieved by friction.

It should be noted that the first rotation driving source 15 in the present embodiment is preferably a motor, and other rotation driving sources may be used to implement the first rotation driving source. When the workpiece 36 is driven in a matching manner, the driving belt 16 can be used, a friction wheel can be directly contacted with the driving belt 16, and other manners can be used for driving the workpiece 16 to rotate.

As shown in fig. 4, the grinding mechanism 5 includes a rotary platform 20 disposed on the frame 1, a cross guide rail 21 is disposed on the rotary platform 20, a second rotary drive source 22 is slidably disposed on the cross guide rail 21, and a grinding wheel 23 capable of contacting with an end of a workpiece 36 on the carriage 4 is connected to an output end of the second rotary drive source 22.

The grinding wheel 23 can make the grinding wheel 23 move forward and backward, left and right and rotate by a rotation angle relative to the workpiece 36 under the action of the rotary platform 20 and the cross guide rail 21 so as to control the size of the abnormal shape, the angle and the end surface radius of the end part of the workpiece 36.

The specific structures of the rotary platform 20 and the cross guide rail 21 are only products on the market in the prior art, and detailed descriptions on the specific structures are omitted in the application. It is within the scope of the present application for the grinding wheel 23 to function substantially as a grinding wheel for grinding the end of the workpiece 36, such as by replacing it with a tool or the like.

Preferably, in this embodiment, the axis of the grinding wheel 23 intersects with the axis of the workpiece 36 on the bracket 4 to form an included angle, one end of the workpiece 36 on the bracket 4 can contact with the grinding wheel 23, the frame 1 is provided with a position-limiting piece 26 capable of contacting with the other end of the workpiece 36 on the bracket 4, and the point where the position-limiting piece 26 contacts with the workpiece 36 on the bracket 4 can move along the length direction of the workpiece 36.

Preferably, the limiting piece 26 is made of elastic metal, one end of the limiting piece 26 is fixed on the frame 1, the other end of the limiting piece 26 is arranged in a suspended manner, the outer surface of the limiting piece 26 can be in contact with the other end of the workpiece 36 on the bracket 4, the frame 1 is further provided with a sliding rod 27 capable of moving along the axial direction of the workpiece 36 on the bracket 4, and the end part of the sliding rod 27 is attached to the inner surface of the limiting piece 26.

Specifically, a threaded hole may be formed in the frame 1, the sliding rod 27 is connected to the threaded hole, and the sliding rod 27 is rotated to move axially while rotating, so as to push the limiting piece 26 to drive the workpiece 36 to move axially, and when the sliding rod 27 is rotated reversely and retracted, the limiting piece 26 may be rebounded and reset under its own elasticity.

Of course, as another solution, the sliding rod 27 may also be directly slidably disposed on the frame 1, and a damping device or a fastening device capable of fixing the sliding rod with respect to the frame is disposed between the sliding rod 27 and the frame, and the limiting piece 26 may also be disposed in a suspended manner and directly fixed to the end of the sliding rod 27.

As shown in fig. 4, in order to prevent the grinding wheel 23 from becoming dull after a long period of use, the rotary table 20 is further provided with a dresser blade holder 24, and the dresser blade holder 24 is provided with a dresser blade 25 capable of contacting the grinding wheel 23.

As shown in fig. 5, the grinding machine further comprises a cooling system 28, the cooling system 28 comprises a water tank 29, a water pump 30, a pipeline 31 and a nozzle 32, the water tank 29 is fixed on the frame 1, one end of the water pump 30 is communicated with the water tank 29, the other end of the water pump 30 is communicated with the nozzle 32 through the pipeline 31, and the nozzle 32 is aligned with the grinding position of the grinding wheel 23; a water collecting groove 33 positioned below the grinding position is formed in the frame 1, and a water return flow passage 34 is arranged between the water collecting groove 33 and the water pool 29. When the water-cooling device is used, the water pump 30 can pump out cooling water in the water pool 29 and spray the cooling water at a grinding position through the pipeline 31 and the nozzle 32, and the sprayed water can flow back to the water pool 29 through the water collecting tank 33 and the water return flow channel 34 to be recycled.

As shown in fig. 6, in order to realize the unified and coordinated control of the various mechanisms of the grinding machine, the grinding machine further includes a control system 35, and the control system 35 is connected with the linear drive source 7, the first rotary drive source 15, the rotary platform 20, the cross guide rail 21, the second rotary drive source 22 and the water pump 30. Specifically, the DF-302Gi numerical control system may be selected as a core, and has functions of a 3-coordinate input system, feed and retract control, feed compensation, station change, feed compensation after grinding wheel dressing, and the like, and automatic machining is realized by repeated operations of feeding a workpiece, radial rotation of the workpiece, grinding of the grinding wheel, retraction of the workpiece, and dressing of the grinding wheel.

As shown in fig. 7, the working principle of the present invention is as follows: the workpiece 36 is placed in the material box 2 and reaches the discharge port at the lower end through gravity, at the moment, the groove 8 on the bracket 4 retracts to the position below the discharge port, the workpiece 36 can fall into the groove 8, then the linear driving source 7 drives the bracket 4 to move towards the rotating mechanism 3, in the moving process, the workpiece 36 can be in contact with the movable plate 14, the movable plate 14 is enabled to turn outwards, and finally the workpiece 36 reaches the rotating mechanism 3 and is in contact with the moving transmission belt 16, so that the workpiece 36 rotates radially and synchronously; the grinding wheel 23 rotating at the grinding mechanism 5 can move towards the workpiece 36 under the action of the cross guide rail 21 and contact with the workpiece, and then the grinding wheel 23 can rotate for a certain angle under the action of the rotary platform 20, so that the end part of the workpiece 36 is ground into an arc to form a sharp angle. In the process, the angle of the sharp corner and the size of the circular arc can be adjusted by the control system 35.

After grinding is finished, the grinding wheel 23 can move and reset in the direction away from the workpiece 36 under the action of the cross guide rail 21. The bracket 4 can move towards the direction of the material box 2 under the action of the linear driving source 7 until the processed workpiece 36 is contacted with the outer plate surface of the movable plate 14 and falls into the discharging disc 6 under the blocking action of the movable plate 14, so that automatic feeding, grinding and material returning are realized.

It should be noted that the above-mentioned working principle is only the most preferable way of the present apparatus, and it is within the protection scope of the present application to use the present apparatus to process by other working principles.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Claims

1. An automatic grinding machine, characterized in that the grinding machine comprises:

a frame (1);

the material box (2) is obliquely arranged on the rack (1), and a discharge hole for a workpiece (36) to pass through is formed in the lower end of the material box (2);

the rotating mechanism (3) is arranged on the rack (1) and can drive the workpiece (36) to rotate;

the bracket (4) is movably arranged on the rack (1) and can convey the workpiece (36) at the discharge port of the material box (2) to the rotating mechanism (3);

the grinding mechanism (5) is arranged on the frame (1), and can grind the end part of the workpiece (36);

go out workbin (6), go out workbin (6) and set up in frame (1), and be located the below of bracket (4), bracket (4) can carry the work piece (36) that the grinding finishes to a workbin (6) department.

2. The automatic grinding machine according to claim 1, characterized in that the frame (1) is provided with a linear drive source (7), the output end of the linear drive source (7) faces the rotating mechanism (3), the bracket (4) is positioned below the magazine (2) and fixed on the output end of the linear drive source (7), and the bracket (4) is further provided with a groove (8) for receiving a workpiece (36); the groove (8) is obliquely arranged, and the rear end of the groove (8) is higher than the front end of the groove (8); the automatic feeding device is characterized in that a front roller (9) and a rear roller (10) corresponding to the groove (8) are further arranged on the bracket (4), the front roller (9) is close to the rotating mechanism (3), the rear roller (10) is close to the material box (2) and higher than the front roller (9), and the side surface of the workpiece (36) can be simultaneously in contact with the wheel surface of the front roller (9) and the wheel surface of the rear roller (10).

3. The automatic grinding machine according to claim 2, characterized in that the magazine (2) comprises a bottom plate (11), a side plate (12) and a baffle plate (13), the bottom plate (11) and the side plate (12) are fixed, the baffle plate (13) is fixed at the lower end of the side plate (12) and is arranged at a distance from the bottom plate (11) to form the discharge port; the grinding machine further comprises a movable plate (14), the upper end of the movable plate (14) is hinged to the outer plate surface of the baffle plate (13), the hinge point of the movable plate and the baffle plate is higher than the lower edge of the baffle plate (13), and a workpiece (36) can be in contact with the movable plate (14) when the workpiece (36) is placed on the bracket (4).

4. The automatic grinding machine according to claim 3, characterized in that the turning mechanism (3) comprises a first rotary drive source (15), a transmission belt (16) and a tension bracket (17), the first rotary drive source (15) is fixed on the frame (1), one end of the transmission belt (16) is connected with the output end of the first rotary drive source (15), and the other end of the transmission belt (16) is wound on the tension bracket (17) and can be contacted with the workpiece (36).

5. The automatic grinding machine according to claim 4, characterized in that a driving wheel (18) is fixed on the output end of the first rotary driving source (15), two driven wheels (19) corresponding to the driving wheel (18) are rotatably arranged on the tensioning bracket (17), the transmission belt (16) is wound on the driving wheel (18) and the driven wheels (19) in sequence, and the workpiece (36) can be contacted with a part of the transmission belt (16) positioned between the two driven wheels (19).

6. The automatic grinding machine according to claim 5, characterized in that the grinding mechanism (5) comprises a rotary platform (20) arranged on the frame (1), a cross guide rail (21) is arranged on the rotary platform (20), a rotary driving source II (22) is arranged on the cross guide rail (21) in a sliding manner, and a grinding wheel (23) capable of contacting with the end of a workpiece (36) on the bracket (4) is connected to the output end of the rotary driving source II (22).

7. The automatic grinding machine according to claim 6, characterized in that a dressing tool holder (24) is further provided on the rotary platform (20), and a dressing blade (25) contactable with the grinding wheel (23) is provided on the dressing tool holder (24).

8. The automatic grinding machine tool according to claim 7, characterized in that the axis of the grinding wheel (23) and the axis of the workpiece (36) on the bracket (4) intersect to form an included angle, one end of the workpiece (36) on the bracket (4) can contact with the grinding wheel (23), the frame (1) is provided with a limiting piece (26) which can contact with the other end of the workpiece (36) on the bracket (4), and the point where the limiting piece (26) contacts with the workpiece (36) on the bracket (4) can move along the length direction of the workpiece (36).

9. The automatic grinding machine tool according to claim 8, characterized in that the limiting sheet (26) is made of elastic metal, one end of the limiting sheet (26) is fixed on the frame (1), the other end of the limiting sheet (26) is arranged in a suspended manner, the outer surface of the limiting sheet (26) can be in contact with the other end of the workpiece (36) on the bracket (4), the frame (1) is further provided with a sliding rod (27) capable of moving along the axial direction of the workpiece (36) on the bracket (4), and the end part of the sliding rod (27) is attached to the inner surface of the limiting sheet (26).

10. The automatic grinding machine according to claim 9, characterized in that the grinding machine further comprises a cooling system (28), the cooling system (28) comprises a water tank (29), a water pump (30), a pipeline (31) and a nozzle (32), the water tank (29) is fixed on the frame (1), one end of the water pump (30) is communicated with the water tank (29), the other end of the water pump (30) is communicated with the nozzle (32) through the pipeline (31), and the nozzle (32) is aligned with the grinding position of the grinding wheel (23); a water accumulating tank (33) positioned below the grinding position is arranged on the frame (1), and a water return flow passage (34) is arranged between the water accumulating tank (33) and the water pool (29); the grinding machine tool further comprises a control system (35), wherein the control system (35) is connected with the linear driving source (7), the first rotary driving source (15), the rotary platform (20), the cross guide rail (21), the second rotary driving source (22) and the water pump (30).