Secondary positioning device for the material bin of a turning and grinding center

Abstract

The present invention provides a secondary positioning device for a material bin of a turning and grinding center. The material bin of the turning and grinding center uses a chain to transport the gears to be processed. A number of trays for installing the gears to be processed are arranged at equal intervals along the length direction of the chain. A vertical positioning column perpendicular to the tray is coaxially fixed on the tray. The center hole of the gear to be processed can be sleeved outside the positioning column and can rotate relative to the positioning column. The chain of the present invention drives the tray to circulate on the material bin. When the gear to be processed moves with the chain and stops at the grasping station, the gear to be processed is rotated around the positioning column by a pin to accurately position the tooth position of the gear to be processed. Three positioning members can determine a circle. The repeated position accuracy of the tray is accurately positioned by three positioning members to accurately position the position of the tooth groove to be processed on the tray, so as to accurately position the position and tooth position of the gear to be processed, and ensure the high precision and stability of the pitch circle fixture for grasping the gear to be processed.

Description

Technical Field

[0001] The present invention belongs to the technical field of gear processing, and particularly relates to a secondary positioning device for a stock bin of a turning and grinding center. Background Art

[0002] As is well known, the automotive emission standards are getting higher and higher. Therefore, the precision requirements for automotive transmission gears are also getting higher and higher, the requirements for the consistency of dimensions and tolerances are also getting higher and higher, and CPK also needs to be evaluated. Therefore, the processing of automotive transmission gears is a difficult point and a model in machining.

[0003] Currently, for the post-heat treatment processing of such parts in mainstream automotive manufacturers, generally, the large surplus is removed by turning the inner and outer circles and the end faces first, then the workpiece is transferred to an internal grinding machine to complete the internal hole grinding process, and then transferred to an external grinding machine to complete the external circle grinding process or the end face grinding process, and then transferred to a gear grinding machine to complete the gear grinding process by positioning with the internal hole and the end face. This processing method generally has problems such as the need for transfer, inaccurate and unstable gear precision caused by secondary clamping, and long processing cycle.

[0004] In order to achieve the post-heat treatment turning and grinding compound processing of automotive transmission gears, the applicant has developed a vertical turning and grinding compound processing center (referred to as a turning and grinding center). This turning and grinding center can complete the processing of processes such as turning the internal hole, external circle, and both end faces, grinding the internal hole, grinding the external circle, or grinding the end face of the gear after heat treatment with a single clamping, meeting the high-efficiency requirements for automotive transmission gears.

[0005] This turning and grinding center uses a stock bin to complete automatic feeding, enabling the turning and grinding center to achieve automatic processing. To meet the needs of gear processing, a pitch circle fixture is used for gear clamping. Since the pitch circle fixture needs to clamp the gear by aligning the teeth, high requirements are imposed on the state of the gear (the position of the gear and the position of the gear teeth). Therefore, the automatic feeding mechanism stock bin needs secondary precise positioning to meet the requirements of the grasping position. As is well known, the transmission method used in the stock bin is chain drive, and chain drive has a large error, which cannot meet the requirements of the grasping and positioning accuracy of ±0.05 mm and the perpendicularity of 0.02 mm of the turning and grinding center spindle. Therefore, there is an urgent need for a secondary positioning device for the stock bin of the turning and grinding center to meet the high-precision grasping requirements of the turning and grinding center. Summary of the Invention

[0006] The present invention aims to solve the technical problems existing in the prior art, and the object of the present invention is to provide a secondary positioning device for a stock bin of a turning and grinding center.

[0007] To achieve the above object, the present invention adopts the following technical solution: a secondary positioning device for a lathe-milling center bin. The lathe-milling center bin uses a chain to transport the gears to be processed. A number of trays for mounting the gears to be processed are arranged at equal intervals in the length direction of the chain. The secondary positioning device includes a base and a working platform mounted on the base. The working platform has a grasping station corresponding to the pitch circle fixture for grasping the gears to be processed. The chain can pass through the working platform and transport the gears to be processed to the grasping station. The tray is disc-shaped, and a vertical positioning post perpendicular to the tray is coaxially fixed on the tray. The central hole of the gear to be processed can be sleeved outside the positioning post and can rotate relative to the positioning post. A tooth positioning device for positioning the tooth position of the gear to be processed and a tray positioning device for positioning the position of the tray moving to the grasping station are mounted on the working platform. The tooth positioning device includes a pin arranged at the grasping station and a first driving mechanism for driving the pin to move. The pin has a tooth positioning state of protruding and a retracted yielding state. When the pin is in the yielding state, the gear to be processed can reach or leave the grasping station. When the tray is at the grasping station and the pin is in the tooth positioning state, the pin can be inserted into the tooth slot of the gear to be processed and make the gear to be processed rotate around the positioning post. The tray positioning device includes three positioning members mounted on the working platform and capable of surrounding the outer circumference of the tray. The three positioning members are respectively a first positioning member and two second positioning members located on the opposite side of the first positioning member. The distance between the first positioning member and the second positioning members is adjustable, and the distance between the two second positioning members is adjustable or fixed. The tray positioning device composed of the three positioning members has a positioning state and a passing state. When the tray positioning device is in the passing state, at least one positioning member moves away from the other positioning members, and the tray can reach or leave the grasping station. When the tray is at the grasping station and the tray positioning device is in the positioning state, the three positioning members can simultaneously abut against the outer wall of the tray and make the tray move laterally.

[0008] In the above technical solution, the chain drives the tray to circulate on the bin, and the positioning post and the gear to be processed move with the tray along with the chain. When the gear to be processed moves with the chain and stops at the grasping station, the tooth position of the gear to be processed is accurately positioned by inserting the pin into the tooth slot of the gear to be processed and making the gear to be processed rotate around the positioning post. A circle can be determined by the three positioning members, and the repeated position accuracy of the tray is accurately positioned by the three positioning members to accurately position the position of the tooth slot to be processed on the tray. The present invention can accurately position the position and tooth position of the gear to be processed located at the grasping station, ensuring the high precision and stability of the pitch circle fixture for grasping the gear to be processed.

[0009] In a preferred embodiment of the present invention, the first driving mechanism is a first cylinder mounted on the working platform and located on one side of the chain, and the telescopic shaft of the first cylinder is fixedly connected to the pin.

[0010] In the above technical solution, the first cylinder is used to drive the bolt to move, and the operation is reliable.

[0011] In a preferred embodiment of the present invention, the first driving mechanism drives the bolt to move in a direction perpendicular to the chain.

[0012] In a preferred embodiment of the present invention, the first positioning member and the second positioning member are respectively located on both sides of the chain. The first positioning member is a fixed block fixedly connected to the working platform, and the fixed block has a chamfer for guiding the tray to enter the grasping station. The second positioning member is connected with a second driving mechanism for driving it to move closer to or away from the first positioning member. The two second positioning members are driven by a set of second driving mechanisms or each of the two second positioning members is driven by a set of second driving mechanisms.

[0013] In the above technical solution, the first positioning member is fixedly arranged, and the tray positioning device switches between the passing state and the positioning state. It only needs to make the second positioning member move closer to or away from the first positioning member, and the movement mode is simple and reliable.

[0014] In a preferred embodiment of the present invention, the second driving mechanism is a second cylinder installed on the working platform, and the telescopic shaft of the second cylinder is connected to the second positioning member.

[0015] In the above technical solution, the second cylinder is used to drive the bolt to move, and the operation is reliable.

[0016] In another preferred embodiment of the present invention, the distance between the two second positioning members is not adjustable. The second positioning member is a runner rotatably installed on the connecting frame and capable of abutting against the outer wall of the tray. The second driving mechanism drives the connecting frame to move so that the second positioning member approaches or moves away from the first positioning member.

[0017] In the above technical solution, the two second positioning members are installed on the connecting frame and the distance between them is relatively fixed. It only needs the second driving mechanism to drive the connecting frame to move linearly, and the tray positioning device can be switched between the passing state and the positioning state, minimizing the position deviation caused by the movement of parts and improving the positioning accuracy of the secondary positioning device.

[0018] In another preferred embodiment of the present invention, the tooth positioning device further includes a tooth-pushing pin installed on the working platform. The tooth-pushing pin is located upstream of the grasping station and can insert into the tooth groove of the gear to be processed passing through it and make the gear to be processed rotate around the positioning column.

[0019] In the above technical solution, by setting the tooth-pushing pin, the tooth position of the gear to be processed is roughly positioned before it runs to the grasping station, making the subsequent fine positioning by the bolt faster and more convenient.

[0020] In another preferred embodiment of the present invention, a proximity switch for detecting whether the tray reaches the grasping station is further provided on the working platform.

[0021] In the above technical solution, the proximity switch is provided to detect whether the tray reaches the grasping station. After the tray is in place, the chain stops running, and then the tray positioning device and the first driving mechanism start to work, avoiding the idle stroke operation of the tray positioning device and the first driving mechanism.

[0022] In another preferred embodiment of the present invention, a detection device for detecting whether there is a gear to be processed on the tray at the grasping station is further installed on the working platform. The detection device includes a photoelectric emitter and a reflector paired with the photoelectric emitter. The photoelectric emitter and the reflector are respectively located on both sides of the chain.

[0023] In the above technical solution, the photoelectric emitter emits a photoelectric signal, and the reflector reflects the signal. Whether the photoelectric emitter receives the reflected signal is used to judge whether there is a gear to be processed on the tray, ensuring the accuracy of the pitch circle fixture for grasping the gear to be processed each time.

[0024] In another preferred embodiment of the present invention, the lower end of the pitch circle fixture has a claw extending horizontally inward. The height of the claw is greater than the distance between the upper end surface of the working platform and the lower end surface of the gear to be processed. The working platform is floatingly connected to the base through a spring tightening device. Under the action of the spring tightening device, the claw can extend between the working platform and the gear to be processed and abut against both of them.

[0025] In the above technical solution, by setting the spring tightening device, the working platform can float up and down, so that the claw can extend between the working platform and the gear to be processed and abut against both of them, thereby ensuring the fit between the pitch circle fixture and the gear and ensuring that the pitch circle fixture grasps the gear to be processed in place.

[0026] Compared with the prior art, the preferred technical solution of the present invention has the following beneficial effects: The chain drives the tray to circulate on the magazine, and the positioning post and the gear to be processed move with the tray along with the chain. When the chain is running, the tooth position of the gear to be processed is rough-positioned by the tooth-pulling pin; the proximity switch is used to detect whether the tray reaches the grasping station; the tooth position of the gear to be processed is accurately positioned by the pin; the repeat position accuracy of the tray is precisely positioned by the three positioning parts; the photoelectric emitter emits a photoelectric signal, the reflector reflects the signal, and whether the photoelectric emitter receives the signal is used to judge whether there is a gear on the tray, ensuring the correctness of grasping the part each time; when the pitch circle fixture grasps the part, the spring tightening device makes the working platform float downward to ensure the fit between the pitch circle fixture and the gear to be processed.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 is a three-dimensional structural schematic diagram of the secondary positioning device of the material bin and the pitch circle fixture of the turning and grinding center of the embodiment.

[0030] Figure 2 is a state diagram when the gear to be processed is at the grasping station.

[0031] Figure 3 is Figure 2 a top view plane schematic diagram of

[0032] Figure 4 is Figure 3 a sectional view taken along line A-A in

[0033] Figure 5 is Figure 3 a sectional view taken along line B-B in

[0034] The reference numerals in the accompanying drawings of the specification include: base 10, working platform 11, strip groove 111, spring tightening device 12, chain 20, tray 21, positioning post 22, gear to be processed 30, tooth positioning device 40, tooth shifting pin 41, mounting seat 42, plug pin 43, first driving mechanism (first cylinder) 44, first positioning member 51, second positioning member 52, second driving mechanism (second cylinder) 53, connecting frame 54, proximity switch 60, photoelectric emitter 71, reflector 72, pitch circle fixture 80, and claw 81. Detailed Description of the Embodiments

[0035] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0036] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "vertical", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0037] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the communication inside two elements. It can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0038] The present invention provides a secondary positioning device for a turning and grinding center bin, as Figure 1 shown. The turning and grinding center bin uses a chain 20 to transport the gears 30 to be processed. A number of trays 21 for installing the gears 30 to be processed are arranged at equal intervals in the length direction of the chain 20.

[0039] As Figure 1 and Figure 2 shown, in a preferred embodiment of the present invention, the secondary positioning device includes a base 10 and a working platform 11 installed on the base 10. The working platform 11 has a grasping station corresponding to the pitch circle fixture 80 for grasping the gear 30 to be processed, and the chain 20 can pass through the working platform 11 and transport the gear 30 to be processed to the grasping station. Combining Figure 5 shown, the middle of the working platform 11 has a strip-shaped groove 111 with an upper end opening running through in the length direction of the chain 20. The chain 20 can pass through the strip-shaped groove 111. The lower end of the tray 21 is fixedly connected to the chain 20. When the chain 20 passes through the working platform 11 from the strip-shaped groove 111, the tray 21 passes above the working platform 11. The tray 21 is disc-shaped, and a vertical positioning post 22 perpendicular to the tray 21 is coaxially fixedly connected to the tray 21. The central hole of the gear 30 to be processed can be sleeved outside the positioning post 22 and can rotate relative to the positioning post 22. Installing the gear 30 to be processed using the tray 21 and the positioning post 22 is prior art and will not be elaborated here.

[0040] A tooth positioning device 40 for positioning the tooth position of the gear 30 to be processed and a tray positioning device for positioning the position of the tray 21 moving to the grasping station are installed on the working platform 11.

[0041] Among them, as Figures 2 - 4As shown in the figure, the tooth positioning device 40 includes a pin 43 provided at the grasping station and a first driving mechanism 44 for driving the movement of the pin 43. The first driving mechanism 44 is a first cylinder bolted to the working platform 11 and located on the left side of the chain 20. The telescopic shaft of the first cylinder 44 is arranged horizontally and perpendicular to the chain 20. The right end of the telescopic shaft of the first cylinder 44 is fixedly connected to the pin 43, and the pin 43 is driven by the first cylinder 44 to move in a direction perpendicular to the chain 20. Preferably, the pin 43 is slightly forward-offset from the center line of the gear 30 to be processed perpendicular to the chain 20, for example, offset forward by the distance of one tooth of the gear 30 to be processed.

[0042] The first cylinder 44 drives the pin 43 to move left and right. The pin 43 has a tooth positioning state where it extends to the right and a retracted state where it gives way to the left. When the pin 43 is in the retracted state of giving way, as the chain 20 runs, the gear 30 to be processed can reach or leave the grasping station. When the tray 21 is located at the grasping station, the first cylinder 44 drives the pin 43 to move to the right to a set position, so that the pin 43 is in the extended tooth positioning state. The pin 43 is inserted into the tooth groove of the gear 30 to be processed, and the gear 30 to be processed is rotated around the positioning column 22, thereby accurately positioning the tooth position of the gear 30 to be processed.

[0043] Among them, as Figures 2 - 4 shown, the tray positioning device includes three positioning members installed on the working platform 11 that can surround the outer periphery of the tray 21. The three positioning members can be located on a circle, and the central angle between any two of the three positioning members is less than 180°. The three positioning members are respectively a first positioning member 51 and two second positioning members 52 located on the opposite side of the first positioning member 51. For example, the first positioning member 51 is located on the left side of the chain 20, and the two second positioning members 52 are located on the right side of the chain 20. The distance between the first positioning member 51 and the second positioning members 52 is adjustable, and the distance between the two second positioning members 52 is adjustable or fixed. By adjusting the distance between the positioning members, the tray positioning device composed of the three positioning members has a positioning state and a passing state.

[0044] When the tray positioning device is in the passing state, at least one positioning member moves away from the other positioning members, so that the circle determined by the three positioning members increases, and the tray 21 can reach or leave the grasping station. When the tray 21 is located at the grasping station and the tray positioning device is in the positioning state, the circle determined by the three positioning members becomes smaller. The circle determined by the three positioning members is a positioning standard circle (which needs to be preset in advance), and the three positioning members can simultaneously abut against the outer wall of the tray 21 and move the tray 21 horizontally.

[0045] When the positioning members move to make the pallet positioning device composed of three positioning members in the positioning state, the movement of the positioning members makes a lateral fine adjustment to the position of the pallet 21, so that the outer wall of the pallet 21 coincides with the positioning standard circle, thereby performing precise positioning on the repeated position accuracy of the pallet 21 and ensuring the precise positioning of the position of the processed gear 30 on the pallet 21.

[0046] As Figure 3 and Figure 4 shown, in another preferred embodiment, the first positioning member 51 is a fixed block fixedly connected to the working platform 11 and located on the left side of the chain 20, and the fixed block has a chamfer for guiding the pallet 21 to enter the grasping station. The second positioning member 52 is connected to a second driving mechanism 53 that drives it to move left and right to approach or move away from the first positioning member 51. The two second positioning members 52 are driven by a set of second driving mechanisms 53 or each of the two second positioning members 52 is driven by a set of second driving mechanisms 53. The second driving mechanism 53 is a second air cylinder located on the right side of the chain 20 and installed on the working platform 11 by bolts, and the left end of the telescopic shaft of the second air cylinder 53 is connected to the second positioning member 52.

[0047] In the normal state, the second air cylinder 53 drives the second positioning member 52 to move to the right to make the pallet positioning device in the passing state. At this time, the distance between the first positioning member 51 and the second positioning member 52 perpendicular to the chain 20 is greater than the diameter of the pallet 21, which does not affect the pallet 21 reaching the grasping station. The pallet 21 runs to the grasping station along with the chain 20. The left outer edge of the pallet 21 abuts against the right end of the first positioning member 51 or there is a gap between them. Start the second air cylinder 53 to make the two second positioning members 52 move to the left to the set position, so that the pallet positioning device is in the positioning state (that is, the circle determined by the three positioning members is the positioning standard circle). The two second positioning members 52 move to the left and abut against the right outer edge of the pallet 21 and make the pallet 21 move laterally (fine-tune the position left and right and / or front and back), thereby performing precise positioning on the repeated position accuracy of the pallet 21.

[0048] As Figure 3 and Figure 4 shown, in another preferred embodiment, the distance between the two second positioning members 52 is not adjustable. The two second positioning members 52 are driven by a second air cylinder 53. The second positioning member 52 is a runner rotatably installed on the connecting frame 54 and capable of abutting against the outer wall of the pallet 21. The two runners are symmetrically arranged on both sides of the center line perpendicular to the chain 20 of the processed gear 30, one in front and one behind. The left end of the second air cylinder 53 is fixedly connected to the connecting frame 54, and the second air cylinder 53 drives the connecting frame 54 to move left and right to make the second positioning member 52 approach or move away from the first positioning member 51.

[0049] As Figure 2 and Figure 3As shown, in another preferred embodiment, the tooth positioning device 40 further includes a tooth-pushing pin 41 installed on the working platform 11 on the left side of the chain 20. The tooth-pushing pin 41 is located upstream of the grasping station. An installation seat 42 is fixedly connected to the working platform 11 by bolts. The tooth-pushing pin 41 is fixed on the installation seat 42. The tooth-pushing pin 41 is horizontally arranged and its axis is perpendicular to the chain 20. When the gear 30 to be processed moves forward along with the chain 20 and passes by the tooth-pushing pin 41, the tooth-pushing pin 41 can be inserted into the tooth groove of the gear 30 to be processed passing by it, and make the gear 30 to be processed rotate around the positioning column 22, that is, push the teeth of the gear to be processed, so as to roughly position the tooth position of the gear 30 to be processed.

[0050] As Figure 4 shown, in another preferred embodiment, a proximity switch 60 for detecting whether the tray 21 reaches the grasping station is further provided on the working platform 11. When the tray 21 reaches the grasping station, the tray 21 touches the proximity switch 60 to stop the chain 20 from running, and then the tray positioning device and the first driving mechanism 44 start to work, which are all prior arts and will not be elaborated here.

[0051] As Figure 2 shown, in another preferred embodiment, a detection device for detecting whether there is a gear to be processed on the tray 21 at the grasping station is further installed on the working platform 11. The detection device includes a photoelectric emitter 71 and a reflector 72 paired with the photoelectric emitter 71. The photoelectric emitter 71 and the reflector 72 are respectively located on both sides of the chain 20. When the chain 20 runs, the photoelectric emitter 71 emits a photoelectric signal, and the reflector 72 reflects the signal. Whether the photoelectric emitter 71 receives the reflected signal is used to judge whether there is a gear to be processed on the tray 21, so as to ensure the accuracy of the pitch circle fixture 80 to grasp the gear to be processed each time. Using the photoelectric emitter 71 and the reflector 72 to detect whether there is a part passing by is a prior art, and its principle will not be elaborated here.

[0052] As Figure 1 、 Figure 4 and Figure 5 , in another preferred embodiment, the lower end of the pitch circle fixture 80 has a claw 81 extending horizontally inwards. The height of the claw 81 is greater than the distance between the upper end surface of the working platform 11 and the lower end surface of the gear 30 to be processed. The working platform 11 is vertically and floatingly connected to the base 10 through a spring tightening device 12. For example, each of the four corners of the working platform 11 is connected to the base 10 through a set of spring tightening devices 12. The spring tightening device 12 is a prior art, and its structure will not be elaborated here.

[0053] After the pin 43 accurately positions the tooth position of the gear 30 to be machined, and the first positioning member 51 and the two second positioning members 52 accurately position the repeat position accuracy of the pallet 21, the first cylinder 44 drives the pin 43 to move leftward to reset, and the second cylinder 53 drives the second positioning member 52 to move rightward to reset. The pitch circle fixture 80 operates to grasp the gear 30 to be machined at the grasping station (this process is not an innovation point of the present invention and will not be described in detail here). Under the action of the spring pressing device 12, the pawl 81 of the pitch circle fixture 80 presses down the working platform 11 to make the working platform 11 move downward (for example, move 0.1 mm), increasing the distance between the lower end surface of the gear 30 to be machined and the upper end surface of the working platform 11, so that the pawl 81 can extend between the working platform 11 and the gear 30 to be machined and abut against both. At this time, the fitting of the pitch circle fixture 80 with the lower end surface of the gear 30 to be machined indicates that the pitch circle fixture 80 grasps the gear 30 to be machined in place.

[0054] In the description of this specification, the description with reference to terms such as "preferred embodiment", "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0055] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and purposes of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. The secondary positioning device for the material bin of a turning and grinding center, wherein the material bin of the turning and grinding center uses a chain to transmit the gears to be processed, and a plurality of trays for installing the gears to be processed are arranged at equal intervals in the length direction of the chain, and it is characterized in that The secondary positioning device includes a base and a working platform mounted on the base. The working platform has a grasping station for the indexing fixture to grasp the gear to be processed. The chain can pass through the working platform and convey the gear to be processed to the grasping station. The tray is disc-shaped, and a vertical positioning post perpendicular to the tray is coaxially fixed on the tray. The central hole of the gear to be processed can be sleeved outside the positioning post and can rotate relative to the positioning post. A tooth positioning device for positioning the tooth position of the gear to be processed and a tray positioning device for positioning the position of the tray moving to the grasping station are mounted on the working platform. The tooth positioning device includes a pin provided at the grasping station and a first driving mechanism for driving the pin to move. The pin has a protruding tooth positioning state and a retracted yielding state. When the pin is in the yielding state, the gear to be processed can reach or leave the grasping station. When the tray is at the grasping station and the pin is in the tooth positioning state, the pin can be inserted into the tooth groove of the gear to be processed and make the gear to be processed rotate around the positioning post. The tray positioning device includes three positioning members mounted on the working platform and capable of surrounding the outer circumference of the tray. The three positioning members are respectively a first positioning member and two second positioning members located on the opposite side of the first positioning member. The distance between the first positioning member and the second positioning members is adjustable, and the distance between the two second positioning members is adjustable or fixed. The tray positioning device composed of the three positioning members has a positioning state and a passing state. When the tray positioning device is in the passing state, at least one positioning member moves away from the other positioning members, and the tray can reach or leave the grasping station. When the tray is at the grasping station and the tray positioning device is in the positioning state, the three positioning members can simultaneously abut against the outer wall of the tray and make the tray move laterally.

2. The secondary positioning device for the material bin of the turning and grinding center according to claim 1, characterized in that The first driving mechanism is a first cylinder mounted on the working platform and located on one side of the chain. The telescopic shaft of the first cylinder is fixedly connected to the pin.

3. The secondary positioning device for the material bin of the turning and grinding center according to claim 1, characterized in that The first driving mechanism drives the pin to move in a direction perpendicular to the chain.

4. The secondary positioning device for the magazine of the turning and grinding center according to claim 1, wherein The first positioning member and the second positioning members are respectively located on both sides of the chain. The first positioning member is a fixed block fixedly connected to the working platform, and the fixed block has a chamfer for guiding the tray to enter the grasping station. The second positioning member is connected to a second driving mechanism for driving it to move closer to or away from the first positioning member. The two second positioning members are driven by a set of second driving mechanisms or each of the two second positioning members is driven by a set of second driving mechanisms.

5. The secondary positioning device for the lathe and grinder center bin according to claim 4, wherein The second driving mechanism is a second cylinder mounted on the working platform. The telescopic shaft of the second cylinder is connected to the second positioning member.

6. The secondary positioning device for the magazine of the turning and grinding center according to claim 4, characterized in that The distance between the two second positioning members is not adjustable. The second positioning member is a runner rotatably mounted on the connecting frame and capable of abutting against the outer wall of the tray. The second driving mechanism drives the connecting frame to move so that the second positioning member moves closer to or away from the first positioning member.

7. The secondary positioning device for the material bin of the turning and grinding center according to any one of claims 1-6, characterized in that The tooth positioning device further includes a tooth shifting pin installed on the working platform. The tooth shifting pin is located upstream of the grasping station, and the tooth shifting pin can be inserted into the tooth groove of the gear to be processed passing through it and cause the gear to be processed to rotate around the positioning column.

8. The secondary positioning device for the magazine of the turning and grinding center according to any one of claims 1-6, characterized in that, A proximity switch for detecting whether the pallet reaches the grasping station is further provided on the working platform.

9. The secondary positioning device for the material bin of the turning and grinding center according to any one of claims 1-6, characterized in that A detection device for detecting whether there is a gear to be processed on the pallet at the grasping station is further installed on the working platform. The detection device includes a photoelectric emitter and a reflector paired with the photoelectric emitter. The photoelectric emitter and the reflector are respectively located on both sides of the chain.

10. The secondary positioning device for the magazine of the turning and grinding center according to any one of claims 1-6, characterized in that, The lower end of the pitch circle fixture has a claw extending horizontally inward. The height of the claw is greater than the distance between the upper end surface of the working platform and the lower end surface of the gear to be processed. The working platform is floatingly connected to the base through a spring tightening device. Under the action of the spring tightening device, the claw can extend into the space between the working platform and the gear to be processed and abut against both of them.

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