Integrated tool changing tool for spot welding robot

Abstract

The invention relates to the technical field of friction stir spot welding, in particular to an integrated tool changing tool for a spot welding robot. In the using process, the stirring needle and the stirring sleeve are jacked up in sequence through the two-section type stepped shaft formed through cooperation of the first ejector pin and the second ejector pin, and installation of the stirring needle, the stirring sleeve and the pressing sleeve is completed in sequence in cooperation with the downward pressing action of the FSSW robot. In the whole installation process, the FSSW robot only conducts sectional type downward pressing action on the same plumb line, the action stroke is short, the speed is high, and therefore the installation time is effectively shortened. Meanwhile, due to the single plumb downward pressing action, horizontal displacement of the plumb is avoided, the tool changing space is reduced to be close to the peripheral side of the plumb line, and therefore excessive occupied space is reduced. That is to say, the whole tool changing process can be rapidly completed in a small space, which is a highlight of the tool changing device.

Description

Technical Field

[0001] The invention relates to the technical field of friction stir spot welding, in particular to an integrated tool changing tool for a spot welding robot. Background Art

[0002] In the field of workpiece welding, friction stir welding (FSW) is widely used due to its advantages such as low welding temperature and small welding deformation. The derivative equipment of FSW, FSSW (friction stir spot welding), has gradually begun to replace traditional spot welding. As the core components of friction stir spot welding, the stirring needle, stirring sleeve and clamping sleeve are first clamped by the FSSW robot during installation, and then the stirring needle is carried through the stirring sleeve and the stirring sleeve is placed on the needle head, and finally the clamping sleeve is placed on the outside of the stirring sleeve to complete the entire tool change process.

[0003] The common tool changing method of FSSW robot is to place the stirring needle, stirring sleeve and pressing sleeve in different positions, and then move them to the corresponding positions for sleeve installation according to the above tool changing process. Although the above tool changing method can complete the replacement of welding tools, the installation time is relatively long because the FSSW robot needs to move to different positions; at the same time, during the tool changing process, the FSSW robot needs to move horizontally to three positions to complete the replacement of the stirring needle, stirring sleeve and pressing sleeve, which will result in too much space for the FSSW robot to change tools.

[0004] It can be seen that there is an urgent need for a device that can shorten the tool changing time and simultaneously reduce the tool changing space during the tool changing process of the FSSW robot, so as to effectively solve the above technical problems. Summary of the invention

[0005] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides an integrated tool changing tool for a spot welding robot. The present invention effectively reduces the tool changing time and reduces the tool changing space through the integrated tool changing tool.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An integrated tool changer for a spot welding robot includes a support seat for placing a stirring needle, a stirring sleeve and a pressing sleeve that are connected in sequence, a lifting telescopic rod is installed on the support seat, and a lifting part is installed at the telescopic end of the lifting telescopic rod; the lifting part includes a first ejector pin for vertically lifting the stirring needle, and a second ejector pin for vertically lifting the stirring sleeve, the first ejector pin and the second ejector pin move upward synchronously, and the top of the first ejector pin is higher than the top of the second ejector pin, so as to lift the stirring needle and the stirring sleeve in sequence. The first ejector pin and the second ejector pin are both inverted T-shaped, and an axial hole is opened through the axis of the second ejector pin; the top of the first ejector pin passes through the axial hole upward and cooperates with the top of the second ejector pin to form a two-stage stepped shaft for lifting the stirring needle and the stirring sleeve in steps.

[0008] As a further solution of the present invention: a spring sleeve is installed at the telescopic end of the lifting telescopic rod, the second ejector pin is coaxially fixed on the spring sleeve, the bottom of the first ejector pin is coaxially installed in the spring sleeve, and a lifting spring is compressed between the bottom of the first ejector pin and the inner bottom surface of the spring sleeve.

[0009] As a further solution of the present invention: the support seat includes a horizontally arranged workbench, on which an axially plumbly arranged work hole is penetrated; a guide sleeve is coaxially fixed in the working hole, and a connecting sleeve is coaxially fixed at the bottom end of the working hole; the lifting and telescopic rod is installed at the bottom of the connecting sleeve, and its execution end is located in the connecting sleeve and fixed to the spring sleeve to push the spring sleeve to slide coaxially in the guide sleeve.

[0010] As a further solution of the present invention: the support seat also includes a contoured support member whose inner cavity shape is adapted to the outer shape of the compression sleeve and is used to support the compression sleeve with the bearing from bottom to top, and the contoured support member is elastically lifted and lowered on the workbench along the vertical direction.

[0011] As a further solution of the present invention: the contoured support member includes a positioning sleeve and a positioning ring integrally formed and installed at the bottom of the positioning sleeve, and a two-stage stepped hole with a larger aperture at the top and a smaller aperture at the bottom is provided on the upper ring surface of the positioning ring, and each of the two-stage stepped holes is evenly arranged in sequence along the circumference of the positioning ring; a plurality of threaded holes are provided on the workbench along the circumference of the working hole, and the front end of the bolt passes through the two-stage stepped hole and is threadedly connected to the corresponding threaded hole. A buffer spring is coaxially sleeved on the rod of the bolt located between the positioning ring and the workbench, and the buffer spring is compressed between the positioning ring and the workbench to realize the elastic lifting and lowering installation of the contoured support member.

[0012] As a further solution of the present invention: a plurality of positioning beads for radially positioning the compression sleeve are arranged in sequence along the circumference of the inner sleeve surface of the positioning sleeve, and the positioning beads include a positioning rod installed on the positioning sleeve, and a hemisphere is installed at the front end of the positioning rod. Each hemisphere encloses a positioning cavity that can cover the compression sleeve to radially position it.

[0013] As a further solution of the present invention: a plurality of positioning screw holes are uniformly opened in sequence along the circumference of the positioning sleeve, the axial direction of each positioning screw hole coincides with the radial direction of the positioning sleeve at its position, and the positioning rods are correspondingly connected in the positioning screw holes.

[0014] As a further solution of the present invention: the lifting telescopic rod and the spring sleeve are connected to each other via a floating joint.

[0015] As a further solution of the present invention: the lifting telescopic rod and the spring sleeve are connected to each other through a cylinder joint.

[0016] As a further solution of the present invention: the lifting telescopic rod is a gas cylinder, a hydraulic cylinder or an electric cylinder.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. During the use of the present invention, the two-stage stepped shaft formed by the cooperation of the first ejector pin and the second ejector pin lifts up the stirring needle and the stirring sleeve in turn, and cooperates with the downward pressing action of the FSSW robot to complete the installation of the stirring needle, the stirring sleeve and the clamping sleeve in turn. During the entire installation process, the FSSW robot only performs segmented downward pressing actions on the same plumb line, with a short stroke and fast speed, thus effectively shortening the installation time. At the same time, the single plumb downward pressing action avoids horizontal displacement, thereby reducing the space for tool change to the vicinity of the plumb line, thereby reducing excessive space occupation. That is, the entire tool change process can be completed quickly in a smaller space, which is a highlight of the present invention.

[0019] 2. The setting of the two-stage stepped shaft can effectively improve the integration of the first ejector pin and the second ejector pin, reduce the volume, and can lift the stirring needle and the stirring sleeve in turn, which can be said to kill two birds with one stone.

[0020] 3. The installation of the lifting spring, on the one hand, can make the first ejector pin and the second ejector pin abut against each other under the action of elastic force to form a whole, so as to effectively offset the height deviation between the stirring needle and the stirring sleeve during the lifting process, thereby achieving the purpose of successively lifting the stirring needle and the stirring sleeve; on the other hand, it can provide a buffer force for the mutual abutment of the first ejector pin and the stirring needle, avoiding damage to the stirring needle due to collision between the first ejector pin and the stirring needle.

[0021] 4. The installation of the buffer spring can achieve soft contact during the installation and removal of the compression sleeve. It can float up and down to unload the force, provide buffer force for the positioning sleeve, reduce the instantaneous contact impact force between the positioning sleeve and the compression sleeve, and reduce the damage to the positioning sleeve and the compression sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the internal cross-sectional structure of the present invention.

[0023] Figure 2 It is a schematic diagram of the overall structure of the present invention.

[0024] Figure 3 It is a structural schematic diagram of the workbench in the present invention.

[0025] Figure 4 It is a structural schematic diagram of the positioning sleeve in the present invention.

[0026] In the figure: 1. support seat; 11. workbench; 111. working hole; 12. positioning sleeve; 121. positioning bead; 1211. positioning rod; 1212. hemisphere; 122. positioning screw hole; 13. positioning ring; 131. two-stage stepped hole; 14. bolt; 15. buffer spring; 2. connecting sleeve; 3. guide sleeve; 4. spring sleeve; 5. floating joint; 6. lifting telescopic rod; 71. first ejector pin; 72. second ejector pin; 8. lifting spring; a. stirring needle; b. stirring sleeve; c. pressing sleeve. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] See also Figure 1 to Figure 4 In the embodiment of the present invention, an integrated tool changing tool for a spot welding robot includes a support base 1 composed of a workbench 11, a positioning ring 13 and a positioning sleeve 12. The workbench 11 is fixedly installed on the ground, and an axially vertically arranged working hole 111 is opened through the workbench 11. A guide sleeve 3 is coaxially fixed in the working hole 111, and a connecting sleeve 2 with a larger aperture than the working hole 111 is coaxially fixed at the bottom end of the working hole 111. A cylinder serving as a lifting telescopic rod 6 is installed at the bottom of the connecting sleeve 2. At the same time, in order to cooperate with the extension and retraction of the cylinder, a through hole is opened at the bottom axis of the connecting sleeve 2, so that the actuator end of the cylinder can pass through the through hole and extend into the connecting sleeve 2 to push the spring sleeve 4 to move up and down in the vertical direction.

[0029] In the process of pushing the cylinder up and down, in order to further improve the stability of the push, in addition to fixing the cylinder body to the bottom of the connecting sleeve 2 in a relatively firm manner, the actuator end of the cylinder is also coaxially arranged with the through hole. By coaxially pushing, the friction between the spring sleeve 4 and the guide sleeve 3 caused by the possible eccentric error is reduced as much as possible. At the same time, in order to further reduce the eccentric friction between the spring sleeve 4 and the guide sleeve 3 caused by the assembly error, a floating joint 5 is installed at the actuator end of the cylinder, and power is transmitted through the floating joint 5. Then, with the help of the gap adjustment property of the floating joint 5 itself, the eccentric friction between the spring sleeve 4 and the guide sleeve 3 is effectively eliminated to improve the smoothness of the cylinder push. In addition, the floating joint 5 can also be replaced with a corresponding cylinder joint, which is intended to correct the deviation of the spring sleeve 4 and maintain its coaxiality with the guide sleeve 3.

[0030] The second ejector pin 72 is coaxially fixed to the top of the spring sleeve 4, and the second ejector pin 72 is a hollow inverted T-shape, that is, an axial hole is opened through the axis of the second ejector pin 72. The first ejector pin 71, which is also inverted T-shaped, is coaxially inserted into the axial hole from bottom to top, and its top end passes through the axial hole and cooperates with the top end of the second ejector pin 72 to form a two-stage stepped shaft, so as to lift the stirring pin a and the stirring sleeve b from bottom to top in sequence.

[0031] Since the bottom of the second ejector pin 72 is coaxially covered on the top of the spring sleeve 4, the bottom of the first ejector pin 71 is coaxially inserted in the spring sleeve 4. At the same time, in order to maintain the two-stage stepped shaft formed by the cooperation of the first ejector pin 71 and the second ejector pin 72, a lifting spring 8 is compressed and installed between the bottom of the first ejector pin 71 and the inner bottom surface of the spring sleeve 4, so that the first ejector pin 71 and the second ejector pin 72 are always tightly fitted under the elastic lifting action of the lifting spring 8. Since the lifting spring 8 is a flexible structure, it is easy to be eccentric during its operation, which causes it to provide an eccentric thrust to the first ejector pin 71, resulting in eccentric friction between the first ejector pin 71 and the second ejector pin 72. In order to effectively eliminate the eccentric friction, a positioning shaft can be coaxially fixedly installed at the bottom of the first ejector pin 71, and the lifting spring 8 is coaxially sleeved on the positioning shaft. And the matching clearance between the positioning shaft and the lifting spring 8 is small, so that the eccentric deformation of the lifting spring 8 can be effectively reduced through the small matching clearance. At the same time, in order not to hinder the retraction of the first ejector pin 71 , a certain movement gap is reserved between the bottom of the positioning shaft and the inner bottom surface of the spring sleeve 4 , and the movement gap is greater than the length of the top of the first ejector pin 71 extending from the second ejector pin 72 .

[0032] At this point, the first ejector pin 71, the second ejector pin 72, the spring sleeve 4, the ejection spring 8 and the floating joint 5 together constitute a ejection portion installed on the top end of the cylinder.

[0033] The support seat 1 also includes a positioning sleeve 12 for supporting the bearing support compression sleeve c from bottom to top, and a positioning ring 13 coaxially installed on the lower side of the positioning sleeve 12, and the positioning sleeve 12 and the positioning ring 13 are integrally formed to form a contoured support member whose inner cavity shape is adapted to the outer shape of the compression sleeve c.

[0034] A two-stage stepped hole 131 with a larger diameter at the top and a smaller diameter at the bottom is provided on the upper ring surface of the positioning ring 13, and each of the two-stage stepped holes 131 is evenly arranged in sequence along the circumference of the positioning ring 13. A plurality of threaded holes are provided on the workbench 11 along the circumference of the working hole 111, and the front end of the bolt 14 passes through the two-stage stepped hole 131 and is threadedly connected with the threaded hole to install the contour support on the workbench 11. At the same time, in order to reduce the impact of the contour support on the workbench 11 when the compression sleeve c is placed during the process of the contour support sliding down along the bolt 14, a buffer spring 15 is coaxially sleeved on the rod of the bolt 14 located between the contour support and the workbench 11. The buffer spring 15 is elastically compressed between the contour support and the workbench 11 to provide real-time buffering force for the buffering process of the compression sleeve c and achieve soft contact placement.

[0035] Since the matching tolerance of the contour support was increased at the beginning of its design in order to adapt to a variety of different sizes of compression sleeves c, this operation will cause some smaller compression sleeves c to be easily eccentric and tilted when placed in the contour support, so that they cannot be aligned with the FSSW robot in the later stage, and thus cannot complete the tool replacement. Therefore, in order to overcome this problem, a plurality of positioning screw holes 122 are opened on the positioning sleeve 12 in the contour support, and positioning beads 121 are installed in each positioning screw hole 122.

[0036] Each positioning screw hole 122 is uniformly opened on the positioning sleeve 12 along the circumference of the positioning sleeve 12, and the axial direction of each positioning screw hole 122 coincides with the radial direction of the positioning sleeve 12 at its position. The positioning bead 121 includes a positioning rod 1211 and a hemispherical body 1212 coaxially mounted on the front end of the positioning rod 1211. The positioning rod 1211 with threads on the outside is threadedly connected in the positioning screw hole 122, and the hemispherical body 1212 extends out of the positioning screw hole 122, and each positioning bead 121 extending out of the positioning screw hole 122 cooperates with each other to form a positioning cavity that clamps the compression sleeve c in the radial direction. When the contour support is working, after determining the model of the compression sleeve c, the compression sleeve c is placed in the contour support, and the conical support surface that gradually shrinks from top to bottom in the positioning ring 13 at the bottom is supported on the conical surface at the bottom of the compression sleeve c. Then, the compression sleeve c is radially moved to make it coaxial with the positioning sleeve 12, and then each positioning rod 1211 is screwed in turn until each positioning bead 121 is at a set installation gap from the outer side of the compression sleeve c. By adjusting the positioning cavity, the radial positioning of the compression sleeve c is achieved, which improves the positioning accuracy of the subsequent FSSW robot tool picking and expands the application range of the contour support.

[0037] In one embodiment, the hemispherical body 1212 in the positioning bead 121 is elastically telescoped in the positioning rod 1211 , so that the positioning bead 121 has the ability to adjust the positioning adaptively.

[0038] The function of the present invention is to realize integrated tool change, that is, when changing the tool, the stirring needle a and the stirring sleeve b are lifted up in sequence and installed on the FSSW robot, and then the clamping sleeve c is installed on the FSSW robot by pressing down, thereby completing the entire tool change process.

[0039] The specific tool changing process is as follows:

[0040] Preparation before tool changing: at least two tool changing fixtures of the present invention are arranged in the tool changing area, some of which are in an empty state for receiving welding tools that need to be replaced on the FSSW robot; other tool changing fixtures are filled with cleaned new welding tools.

[0041] Tool placement process: When the FSSW robot needs to change the tool, the FSSW robot moves from the working area to the tool changing area, and further moves to the top of the unloaded tool changing fixture. Then the FSSW robot moves downward, and at the same time, the cylinder of the tool changing fixture retracts the first ejector pin 71 and the second ejector pin 72 to prevent the first ejector pin 71 and the second ejector pin 72 from contacting the welding tool, providing a larger lowering space for the welding tool. After that, the FSSW robot aligns the outermost compression sleeve c of the tool head and inserts it into the positioning cavity formed by the positioning bead 121. Finally, the FSSW robot releases the welding tool, and at this time, the welding tool all falls onto the contour support; at the same time, under the buffering effect of the buffer spring 15, the rigid impact between the welding tool and the contour support is minimized to reduce the damage to the welding tool.

[0042] Tool removal process: After putting down the welding tool, the FSSW robot moves to the top of the tool changer equipped with the new welding tool. At this time, the FSSW robot moves down to the first welding tool installation position, and the cylinder extends at the same time, pushing the first ejector pin 71 and the second ejector pin 72 upward. During the process of the ejector pin rising, the first ejector pin 71 first lifts the stirring needle a to the first welding tool installation position, and the robot performs the stirring needle broaching action to install it on the FSSW robot; then the second ejector pin 72 lifts the stirring sleeve b to the first welding tool installation position, and the robot performs the stirring sleeve broaching action to install it on the FSSW robot. At this time, the cylinder retracts and drives the first ejector pin 71 and the second ejector pin 72 to reset. At this point, the stirring needle a and the stirring sleeve b have been installed on the FSSW robot. Finally, the FSSW robot continues to move down to the second welding tool installation position, and gradually contacts the clamping sleeve c during the movement process. The robot performs the clamping sleeve broaching action and finally installs the clamping sleeve c on the FSSW robot at the second welding tool installation position. At this point, the tool change process is completed, and the FSSW robot then returns to its original path and continues its previous processing work.

[0043] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An integrated tool changer for a spot welding robot, characterized in that: The invention comprises a support base (1) for placing a stirring needle (a), a stirring sleeve (b) and a pressing sleeve (c) which are sleeved in sequence, a lifting telescopic rod (6) being installed on the support base (1), and a lifting part being installed at the telescopic end of the lifting telescopic rod (6); the lifting part comprises a first lifting pin (71) for lifting the stirring needle (a) vertically upward, and a second lifting pin (72) for lifting the stirring sleeve (b) vertically upward, the first lifting pin (71) and the second lifting pin (72) being moved upward synchronously, The top end of the first ejector pin (71) is higher than the top end of the second ejector pin (72) so as to sequentially lift up the stirring pin (a) and the stirring sleeve (b); the first ejector pin (71) and the second ejector pin (72) are both inverted T-shaped, and an axial hole is provided through the axis of the second ejector pin (72); the top end of the first ejector pin (71) passes through the axial hole upward and cooperates with the top end of the second ejector pin (72) to form a two-stage stepped shaft for lifting up the stirring pin (a) and the stirring sleeve (b) step by step.

2. The integrated tool changing tool for a spot welding robot according to claim 1, characterized in that: A spring sleeve (4) is installed at the telescopic end of the lifting telescopic rod (6), the second ejector pin (72) is coaxially fixed on the spring sleeve (4), the bottom of the first ejector pin (71) is coaxially installed in the spring sleeve (4), and a lifting spring (8) is compressed between the bottom of the first ejector pin (71) and the inner bottom surface of the spring sleeve (4).

3. The integrated tool changing tool for a spot welding robot according to claim 2, characterized in that: The support seat (1) comprises a horizontally arranged workbench (11), and an axially vertically arranged work hole (111) is formed through the workbench (11); a guide sleeve (3) is coaxially fixedly connected in the work hole (111), and a connecting sleeve (2) is coaxially fixedly connected at the bottom end of the work hole (111); the lifting telescopic rod (6) is installed at the bottom of the connecting sleeve (2), and its execution end is located in the connecting sleeve (2) and is fixedly connected to the spring sleeve (4) to push the spring sleeve (4) to slide coaxially in the guide sleeve (3).

4. An integrated tool changing tool for a spot welding robot according to any one of claims 1 to 3, characterized in that: The support seat (1) also includes a contour support member whose inner cavity shape matches the outer shape of the compression sleeve (c) and is used to support the compression sleeve (c) from bottom to top, and the contour support member is elastically lifted and lowered on the workbench (11) along the vertical direction.

5. The integrated tool changing tool for a spot welding robot according to claim 4, characterized in that: The contour support comprises a positioning sleeve (12) and a positioning ring (13) integrally formed and mounted on the bottom of the positioning sleeve (12); a two-stage stepped hole (131) with a larger diameter at the top and a smaller diameter at the bottom is provided on the upper ring surface of the positioning ring (13); and each of the two-stage stepped holes (131) is evenly arranged in sequence along the circumference of the positioning ring (13); a plurality of threaded holes are provided on the workbench (11) along the circumference of the working hole (111); the front end of the bolt (14) passes through the two-stage stepped hole (131) and is threadedly connected with the corresponding threaded hole; a buffer spring (15) is coaxially sleeved on the rod of the bolt (14) located between the positioning ring (13) and the workbench (11), and the buffer spring (15) is compressed between the positioning ring (13) and the workbench (11) to realize the elastic lifting installation of the contour support.

6. The integrated tool changing tool for a spot welding robot according to claim 5, characterized in that: A plurality of positioning beads (121) for radially positioning the compression sleeve (c) are sequentially arranged on the inner sleeve surface of the positioning sleeve (12) along its circumferential direction. The positioning beads (121) include a positioning rod (1211) mounted on the positioning sleeve (12). A hemisphere (1212) is mounted at the front end of the positioning rod (1211). Each hemisphere (1212) encloses a positioning cavity that can cover the compression sleeve (c) to radially position it.

7. The integrated tool changing tool for a spot welding robot according to claim 6, characterized in that: A plurality of positioning screw holes (122) are uniformly arranged in sequence along the circumference of the positioning sleeve (12), and the axial direction of each positioning screw hole (122) coincides with the radial direction of the positioning sleeve (12) at its location, and the positioning rod (1211) is correspondingly connected to the positioning screw hole (122).

8. The integrated tool changing tool for a spot welding robot according to claim 2, characterized in that: The lifting telescopic rod (6) and the spring sleeve (4) are connected to each other via a floating joint (5).

9. The integrated tool changing tool for a spot welding robot according to claim 2, characterized in that: The lifting telescopic rod (6) and the spring sleeve (4) are connected to each other via a cylinder joint.

10. The integrated tool changing tool for a spot welding robot according to claim 1, characterized in that: The lifting telescopic rod (6) is a gas cylinder, an oil cylinder or an electric cylinder.

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