Workpiece positioning device

Abstract

The application discloses a workpiece positioning device, the workpiece is provided with a first positioning structure, and the device comprises a workbench, a positioning jig and a linear driving mechanism which are installed on the workbench; the positioning jig is provided with a second positioning structure which is used for embedding with the first positioning structure of the workpiece; the linear driving mechanism is connected with a rotary driving mechanism, the rotary driving mechanism is connected with a clamping mechanism, the clamping mechanism is used for clamping the workpiece, and the linear driving mechanism is used for driving the workpiece to move in the direction towards and / or away from the positioning jig; when the workpiece contacts the positioning jig, the rotary driving mechanism drives the workpiece to rotate so that the first positioning structure of the workpiece is embedded with the second positioning structure of the positioning jig. The scheme can realize automatic assembly of the workpiece in cooperation with a mechanical hand, reduces labor cost, improves assembly efficiency and assembly precision.

Description

Technical Field

[0001] This invention relates to the field of workpiece positioning technology, specifically a workpiece positioning device. Background Technology

[0002] like Figure 1 The illustrated automotive steering intermediate shaft (hereinafter referred to as intermediate shaft) includes a shaft body 10 and a fork 20. One end of the shaft body 10 is provided with an external spline for connection with the fork, and the other end of the shaft body 10 is provided with an internal spline for connection with other components. The external spline includes a plurality of triangular teeth evenly distributed circumferentially and rectangular teeth embedded between two of the triangular teeth. The rectangular teeth are used for positioning during assembly to ensure that the shaft body and the fork can be connected in a preset positional relationship. Correspondingly, the internal spline includes a plurality of triangular grooves evenly distributed circumferentially and rectangular grooves embedded between two of the triangular grooves. The rectangular grooves are used for positioning during assembly to ensure the positional accuracy of the connection between the shaft body and other components.

[0003] The current manufacturing process for intermediate shafts involves machining the shaft body and fork on a lathe, followed by press-fitting them together. Because the outer wall of the end of the shaft not connected to the fork is smooth and lacks a positioning structure, accurate positioning on a fixture / carrier is difficult. Therefore, currently, during press-fitting, the operator visually observes the rectangular teeth of the external spline on the shaft body and the rectangular grooves of the internal spline on the fork for alignment, then places the aligned components under a press-fitting machine for pressing. This method is inefficient. In view of this, those skilled in the art are continuously striving to find a method for rapid and accurate positioning of the shaft body to improve the press-fitting efficiency of intermediate shafts. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention provides a workpiece positioning device that can automatically position workpieces with different incoming postures, so that all workpieces can be positioned in the same posture, ensuring that the workpieces discharged from the positioning device have a uniform posture. It can cooperate with a robot to realize automatic assembly of workpieces, reduce labor costs, and improve assembly efficiency and assembly accuracy.

[0005] This application discloses a workpiece positioning device. The workpiece has a first positioning structure. The device includes a worktable, a positioning fixture, and a linear drive mechanism mounted on the worktable. The positioning fixture has a second positioning structure for engaging with the first positioning structure of the workpiece. A rotary drive mechanism is connected to the linear drive mechanism, and a clamping mechanism is connected to the rotary drive mechanism. The clamping mechanism is used to clamp the workpiece, and the linear drive mechanism is used to drive the workpiece to move in a direction toward and / or away from the positioning fixture. When the workpiece contacts the positioning fixture, the rotary drive mechanism drives the workpiece to rotate so that the first positioning structure of the workpiece engages with the second positioning structure of the positioning fixture.

[0006] Specifically, the positioning fixture includes a base and an insert connected to the base, and the second positioning structure is disposed on the insert.

[0007] Specifically, the insert is cylindrical, and the end of the insert facing the workpiece has a chamfer.

[0008] Specifically, the base is elastically connected to the worktable.

[0009] Specifically, the base is connected to the worktable via multiple guide posts, and an elastic connector is fitted on the outer wall of the guide posts. The two ends of the elastic connector abut against the base and the worktable, respectively.

[0010] Specifically, the base is provided with a detection plate, and the worktable is provided with a sensor for sensing the detection plate.

[0011] Specifically, the linear drive mechanism includes a transverse drive module connected to the worktable and a longitudinal drive module connected to the transverse drive module, and the rotary drive module is connected to the longitudinal drive module.

[0012] Specifically, the rotary drive module includes a bracket for connecting to the linear drive mechanism and a servo motor connected to the bracket. The clamping mechanism is a gripper cylinder, the cylinder body of which is connected to the output shaft of the servo motor, and the multiple grippers of the gripper cylinder are used to clamp the workpiece.

[0013] Specifically, the rotary drive module further includes a bearing housing and a bearing. The bearing housing is fixedly connected to the bracket, the outer ring of the bearing is fixedly connected to the bearing housing, and the output shaft of the servo motor is fixedly connected to the inner ring of the bearing and extends downward to connect with the cylinder body of the gripper cylinder.

[0014] Specifically, when the first positioning structure is a first positioning tooth, the second positioning structure is a second positioning groove; when the first positioning structure is a first positioning groove, the second positioning structure is a second positioning tooth.

[0015] The present invention has at least the following beneficial effects:

[0016] The workpiece positioning device in this embodiment can automatically position workpieces with different incoming postures, so that all workpieces can be positioned in the same posture, ensuring that the workpieces discharged from the positioning device have a uniform posture. Therefore, when the positioning device is combined with the operation of the robot on the production line, the workpieces can be fully automatically assembled, reducing labor costs and improving assembly efficiency and assembly accuracy.

[0017] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the automotive steering intermediate shaft in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the workpiece positioning device in an embodiment of the present invention;

[0021] Figure 3 yes Figure 2 A magnified view of a section at point A in the middle;

[0022] Figure 4 This is a schematic diagram of the positioning fixture in an embodiment of the present invention;

[0023] Figure 5 yes Figure 2 A magnified view of a section at point B in the middle;

[0024] Figure 6 This is a schematic diagram of the linear drive mechanism in an embodiment of the present invention;

[0025] Figure 7 yes Figure 6 A magnified view of a section at point C.

[0026] The reference numerals in the above figures are as follows: 1. Worktable; 2. Positioning fixture; 21. Base; 22. Insert; 221. Second positioning structure; 222. Chamfer; 23. Guide post; 24. Detection piece; 3. Linear drive mechanism; 31. Lateral drive module; 32. Longitudinal drive module; 4. Rotary drive mechanism; 41. Bracket; 42. Servo motor; 43. Bearing seat; 44. Bearing; 45. Coupling; 46. Connecting shaft; 5. Clamping mechanism; 51. Cylinder; 52. Gripper; 6. Sensor; 10. Shaft; 101. Rectangular groove; 20. Fork. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "fixing," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "below," and "over" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this application.

[0031] Furthermore, the terms "first" and "second" are used only to distinguish between different terms in description and do not have any special meaning.

[0032] The workpiece positioning device in this embodiment is used to automatically align and position the workpiece. The workpiece positioned by this device can be picked up by automated equipment such as a robot arm for quick connection with other components.

[0033] The workpiece for positioning is provided with a first positioning structure to achieve precise positioning of the workpiece. This first positioning structure can be a first positioning tooth protruding from the workpiece surface or a first positioning groove recessed into the workpiece surface. The workpiece can be, for example, a... Figure 1 The shaft 10 shown has a first positioning structure of a rectangular groove 101 in the internal spline (one form of a first positioning groove). The workpiece can also be a product with splines, such as a gear.

[0034] Combination Figures 2 to 4 As shown, the workpiece positioning device in this embodiment mainly includes: a frame, a positioning fixture 2, a linear drive mechanism 3, a rotary drive mechanism 4, and a clamping mechanism 5. The frame has a worktable 1, and the positioning fixture 2 and the linear drive mechanism 3 are both connected to the worktable 1. The positioning fixture 2 has a second positioning structure 221 that engages with the first positioning structure of the workpiece. The horizontal position of the second positioning structure 221 relative to the worktable 1 cannot be adjusted, but its horizontal orientation relative to the worktable 1 can be determined according to the orientation required in subsequent processes. The linear drive mechanism 3 drives the rotary drive mechanism 4 connected to it to move horizontally and vertically. The rotary drive mechanism 4 drives the clamping mechanism 5 connected to it to rotate, and the clamping mechanism 5 clamps the workpiece. The device also includes a control system for controlling the coordinated operation of the linear drive mechanism 3, the rotary drive mechanism 4, and the clamping mechanism 5. This control system can be a PLC, commonly used in the prior art.

[0035] After the clamping mechanism 5 clamps the workpiece, the linear drive mechanism 3 starts to work to drive the workpiece toward the positioning fixture 2. When the workpiece contacts the positioning fixture 2, the rotary drive mechanism 4 drives the workpiece to rotate so that the first positioning structure of the workpiece and the second positioning structure 221 of the positioning fixture 2 are engaged to achieve the positioning of the workpiece. The positioned workpiece is then removed by the robot. Since the robot can keep the workpiece in the same position during the removal process, it can ensure that the workpiece can be assembled with other parts in the preset position in the subsequent process.

[0036] With the above structure, the workpiece positioning device of this embodiment can automatically position workpieces with different incoming postures, so that all workpieces can be positioned in the same posture, ensuring that the workpieces discharged from the positioning device have a uniform posture. Therefore, when the positioning device is combined with the operation of the robot on the production line, the workpiece can be fully automatically assembled, reducing labor costs and improving assembly efficiency and assembly accuracy.

[0037] Combination Figure 3 and Figure 4 As shown, the positioning fixture 2 includes a base 21 and an insert 22 connected to the base 21. The aforementioned second positioning structure 221 is disposed on the insert 22. The insert 22 can be fixedly connected to the base 21 to ensure that the two cannot move relative to each other, thereby improving the accuracy of the second positioning structure 221 in positioning the workpiece. The insert 22 can be cylindrical, with a chamfer 222 at one end facing the workpiece. When the workpiece contacts the insert 22 but the first positioning structure and the second positioning structure 221 are not aligned or engaged, the end of the workpiece can avoid the splines of the workpiece being worn by the insert 22 by contacting the chamfer 222.

[0038] Preferably, the base 21 of the positioning fixture 2 is elastically connected to the worktable 1. Specifically, as follows: Figure 3 and Figure 4 As shown, the base 21 is connected to the worktable 1 via multiple guide posts 23. The guide posts 23 can move up and down relative to the worktable 1. An elastic connector (not shown) is fitted on the outer wall of the guide post 23. One end of the elastic connector abuts against the base 21, and the other end abuts against the worktable 1. The elastic connector is preferably a compression spring. With this design, the positioning fixture 2 has a certain floating space in the longitudinal direction, that is, the insert 22 can float in the axial direction. In this way, the hard contact between the workpiece and the insert 22 can be avoided, which would cause the workpiece teeth to collide and break, thus greatly reducing the workpiece scrap rate.

[0039] Continue to refer to Figure 3 and Figure 4As shown, a detection piece 24 is also connected to the base 21 of the positioning fixture 2, and a corresponding sensor 6 is provided on the worktable 1. The sensor 6 is used to sense whether the detection piece 24 has moved into position and to feed the sensing result back to the control system. Specifically, when the workpiece just contacts the insert 22 on the positioning fixture 2, the elastic connector is compressed, and the positioning fixture 2 moves downward until the detection piece 24 enters the sensing area of ​​the sensor 6. After the sensor 6 feeds back the signal of sensing the detection piece 24 to the control system, the control system controls the rotary drive mechanism 4 to drive the workpiece to rotate slowly in order to seek the engagement of the first positioning structure on the workpiece with the second positioning structure 221 on the insert 22. When the first positioning structure and the second positioning structure 221 are engaged, the insert 22 can move into the interior of the workpiece. As the insert 22 extends into the interior of the workpiece, the elastic connector springs back and resets, driving the positioning fixture 2 to move upward until the detection piece 24 leaves the sensing area of ​​the sensor 6. After the sensor 6 feeds back the signal of sensing the departure of the detection piece 24 to the control system, the control system controls the rotary drive mechanism 4 to stop driving the rotation and the clamping mechanism 5 to release the workpiece. The upward speed of the detection piece 24 is greater than the rotation speed of the workpiece. Therefore, after the first positioning structure and the second positioning structure 221 are engaged, the sensor 6 can sense the departure of the detection piece 24 before the workpiece rotates again and promptly feed back to the control system. The control system can also promptly control the rotation drive mechanism to stop driving the workpiece to rotate, thus avoiding collision and damage to the first positioning structure and the second positioning structure 221.

[0040] Combination Figure 2 and Figure 6 As shown, the linear drive mechanism 3 in this embodiment includes a transverse drive module 31 connected to the worktable 1 and a longitudinal drive module 32 connected to the transverse drive module 31. Specifically, the transverse drive module 31 includes a guide rail connected to the worktable 1, a slide block slidably connected to the guide rail, and a cylinder for driving the slide block to move along the guide rail. The longitudinal drive module 32 is connected to the slide block. Of course, the transverse drive module 31 can also be a lead screw module. The structure of the longitudinal drive module 32 can be the same as that of the transverse drive module 31, or it can be a slide block module.

[0041] Combination Figures 5 to 7As shown, the rotary drive module of this embodiment includes a bracket 41 for connecting to the linear drive mechanism 3 (specifically, the slide of the longitudinal drive module 32) and a servo motor 42 connected to the bracket 41. The clamping mechanism 5 can be a gripper cylinder, the cylinder body 51 of which is fixedly connected to the output shaft (rotating shaft) of the servo motor 42, and multiple grippers 52 of the gripper cylinder jointly clamp the workpiece. Further, the rotary drive module also includes a bearing seat 43 and a bearing 44. The bearing 44 shaft can be fixedly connected to the bracket 41 via a connecting rod, the bearing 44 can be embedded in the bearing seat 43, the outer ring of the bearing 44 is fixedly connected to the bearing seat 43, the output shaft of the servo motor 42 passes through the bearing 44 and is fixedly connected to its inner ring, the output shaft of the servo motor 42 extends out from the inner ring of the bearing 44 and extends downward to connect with the cylinder body 51 of the gripper cylinder. Since the gripper cylinder connected to the output shaft of the servo motor 42 is heavy, the output shaft and gripper cylinder are prone to swaying during rotation. Using bearing 44 and bearing seat 43 to connect the output shaft of the servo motor 42 and the bracket 41 can greatly reduce the above-mentioned swaying problem.

[0042] The output shaft of the servo motor 42 can be connected to the bearing 44 via a coupling 45. One end of the coupling 45 is connected to the housing of the servo motor 42, and the other end is connected to the end face of the bearing 44. The output shaft of the servo motor 42 passes through the coupling 45, and the end of the coupling 45 facing away from the servo motor 42 passes through the bearing 44 via a connecting shaft 46 to connect to the gripper cylinder.

[0043] As described above, the first positioning structure on the workpiece in this embodiment can be a first positioning groove (e.g., a rectangular groove 101) or a first positioning tooth (e.g., a rectangular tooth). When the first positioning structure is a first positioning groove, the second positioning structure 221 is the corresponding second positioning tooth; when the first positioning structure is a first positioning tooth, the second positioning structure 221 is the corresponding second positioning groove.

[0044] The following will use the pressing of shaft 10 and fork 20 as an example to illustrate how the workpiece positioning device of this embodiment works in coordination with the robot to realize the automated (no need for human eye alignment) pressing of shaft 10. It should be noted that since fork 20 has non-cylindrical features, it can be reliably positioned on the press carrier through these non-cylindrical features.

[0045] Step 1: The linear drive mechanism 3 drives the clamping mechanism 5 to leave the position above the positioning fixture 2 and arrive at the position where the robot arm is loaded. The robot arm takes the shaft 10 off the lathe and sends the shaft 10 into the clamping mechanism 5. After the gripper 52 of the gripper cylinder clamps the shaft 10, the robot arm releases and exits.

[0046] Step 2: The linear drive mechanism 3 drives the shaft 10 to move onto the positioning fixture 2 and abut against the insert 22. At this time, the entire positioning fixture 2 is pressed downward. When the sensor 6 senses the detection piece 24, it feeds back to the control system. The control system controls the servo motor 42 to slowly rotate the workpiece until the rectangular groove 101 on the shaft 10 engages with the rectangular teeth on the insert 22. At the same time, the insert 22 moves axially toward the inside of the shaft 10. Under the action of the spring reset, the entire positioning fixture 2 rises upward. The sensor 6 no longer senses the detection piece 24 and feeds back the signal to the control system. The control system controls the servo motor 42 to stop rotating, and at the same time, the gripper cylinder releases the shaft 10, and the shaft 10 completes the positioning.

[0047] Step 3: After the linear drive mechanism 3 drives the clamping mechanism 5 away from the positioning fixture 2, the robot arm clamps the positioned shaft 10 and moves it to the fork 20 on the press. The fork 20 is positioned on the press by the carrier. After the robot arm aligns the shaft 10 and the fork 20, the press presses down to achieve the pressing of the two.

[0048] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A workpiece positioning device, wherein the workpiece is provided with a first positioning structure, characterized in that, The device includes: a worktable and a positioning fixture and a linear drive mechanism mounted on the worktable; the positioning fixture is provided with a second positioning structure for engaging with a first positioning structure of the workpiece; a rotary drive mechanism is connected to the linear drive mechanism, and a clamping mechanism is connected to the rotary drive mechanism, the clamping mechanism is used to clamp the workpiece, and the linear drive mechanism is used to drive the workpiece to move in a direction toward and / or away from the positioning fixture; when the workpiece contacts the positioning fixture, the rotary drive mechanism drives the workpiece to rotate so that the first positioning structure of the workpiece engages with the second positioning structure of the positioning fixture.

2. The workpiece positioning device according to claim 1, characterized in that, The positioning fixture includes a base and an insert connected to the base, and the second positioning structure is disposed on the insert.

3. The workpiece positioning device according to claim 2, characterized in that, The insert is cylindrical, and the end of the insert facing the workpiece has a chamfer.

4. The workpiece positioning device according to claim 2, characterized in that, The base is elastically connected to the workbench.

5. The workpiece positioning device according to claim 4, characterized in that, The base is connected to the worktable via multiple guide pillars. An elastic connector is fitted on the outer wall of the guide pillar, and the two ends of the elastic connector abut against the base and the worktable, respectively.

6. The workpiece positioning device according to claim 5, characterized in that, The base is provided with a detection plate, and the worktable is provided with a sensor for sensing the detection plate.

7. The workpiece positioning device according to claim 1, characterized in that, The linear drive mechanism includes a transverse drive module connected to the worktable and a longitudinal drive module connected to the transverse drive module, and the rotary drive module is connected to the longitudinal drive module.

8. The workpiece positioning device according to claim 1, characterized in that, The rotary drive module includes a bracket for connecting to the linear drive mechanism and a servo motor connected to the bracket. The clamping mechanism is a gripper cylinder, the cylinder body of which is connected to the output shaft of the servo motor, and the multiple grippers of the gripper cylinder are used to clamp the workpiece.

9. The workpiece positioning device according to claim 8, characterized in that, The rotary drive module also includes a bearing housing and a bearing. The bearing housing is fixedly connected to the bracket, the outer ring of the bearing is fixedly connected to the bearing housing, and the output shaft of the servo motor is fixedly connected to the inner ring of the bearing and extends downward to connect with the cylinder body of the gripper cylinder.

10. The workpiece positioning device according to claim 1, characterized in that, When the first positioning structure is a first positioning tooth, the second positioning structure is a second positioning groove; when the first positioning structure is a first positioning groove, the second positioning structure is a second positioning tooth.

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