Quick-change positioning mechanism for modular work fixture

Abstract

The invention discloses a modular work fixture quick-change positioning mechanism which comprises a main fixture (1) and an auxiliary fixture (2) which are arranged on a workbench (35), a plurality of positioning pins (3) are arranged on the workbench (35), and positioning holes (4) matched with the positioning pins (3) are formed in the bottom of the main fixture (1); a main body block (5) and a positioning air cylinder (6) are arranged on the workbench (35), the extending end of the positioning air cylinder (6) is connected with a guide rod (7) arranged in the main body block (5), a working cavity (8) is formed in the main body block (5), and a linkage shaft body (9) is arranged in the working cavity (8). The quick-change structure is arranged for the single clamp unit, the disassembly and assembly process is simplified, the remodeling efficiency is improved, the installation stability of the quick-change structure is improved through the penetrating abutting type structure, and the positioning accuracy of the clamp unit is ensured.

Description

Technical Field

[0001] This invention relates to the field of tooling fixtures, and more specifically to a modular tooling fixture quick-change positioning mechanism. Background Technology

[0002] In the sheet metal welding process, modular design has become the mainstream development direction of tooling fixtures to achieve efficient clamping and fixing of sheet metal parts of different specifications. Quick-change structures allow for rapid switching of fixtures to adapt to different workpieces, significantly improving production changeover efficiency. Existing technologies have already developed solutions for quick-change mechanisms. For example, Chinese utility model patent CN221363336U discloses a quick-change mechanism for a welding robot workstation tooling fixture. This mechanism includes a placement platform for placing workpieces, with tooling fixtures for clamping the workpieces at both ends of the top of the platform. These fixtures consist of a workpiece holder, a locking block, and a locking groove. The locking block, fixedly connected to the bottom of the workpiece holder, engages with corresponding locking grooves on both ends of the top surface of the placement platform. Furthermore, quick-change components for rapid disassembly and replacement of the tooling fixtures are provided at both ends of the bottom of the placement platform.

[0003] However, the aforementioned existing technical solutions still have obvious drawbacks: on the one hand, they concentrate multiple tooling fixture structures on the same placement platform, resulting in a large overall load-bearing weight during quick-change installation, which not only increases the difficulty of movement operations but also reduces the efficiency of changeover; on the other hand, the existing quick-change structure mainly relies on the snap-fit ​​cooperation between the card block and the card slot and the bottom quick-change component to achieve disassembly and assembly. This type of cooperation structure design makes the stability of the tooling fixture insufficient after installation, and it is easy for positioning offset to occur during welding processing, which in turn affects the welding accuracy of sheet metal parts and product quality. Summary of the Invention

[0004] The purpose of this invention is to provide a modular tooling fixture quick-change positioning mechanism. This invention features a quick-change structure for each fixture unit, simplifying the assembly and disassembly process, improving changeover efficiency, and enhancing the installation stability of the quick-change structure through a through-type pressing structure, thus ensuring the positioning accuracy of the fixture unit.

[0005] The technical solution of this invention: a modular tooling fixture quick-change positioning mechanism, including a main fixture and a secondary fixture mounted on a worktable. The worktable has multiple positioning pins, and the bottom of the main fixture has positioning holes that mate with the positioning pins. The worktable has a main block and a positioning cylinder. The extended end of the positioning cylinder is connected to a guide rod located within the main block. The main block has a working chamber, and a linkage shaft is located within the working chamber. The guide rod passes through the end of the linkage shaft and controls the longitudinal displacement of the linkage shaft. A symmetrically hinged fastening side support is connected to the side of the linkage shaft, and the fastening side support is connected to the inner wall of the working chamber via a limiting structure. The side of the main fixture has a positioning plate with a circular hole. The fastening side support passes through the circular hole and abuts against the upper surface of the positioning plate. The bottom of the secondary fixture has a rotating positioning component, and the secondary fixture is connected to the worktable via the rotating positioning component.

[0006] In the aforementioned modular tooling fixture quick-change positioning mechanism, the upper surface of the main block is provided with multiple countersunk holes, and short pins for supporting the positioning plate are provided in the countersunk holes.

[0007] In the aforementioned modular tooling fixture quick-change positioning mechanism, the linkage shaft includes a main shaft, a sleeve is provided on the main shaft, and an extension piece is provided on the side of the sleeve. The fastening side support is hinged to the extension piece; the end of the main shaft is engaged with a guide rod.

[0008] In the aforementioned modular tooling fixture quick-change positioning mechanism, the guide rod includes a main rod connected to the extended end of the positioning cylinder, the end of the main rod having an end head with a slanted groove; the end of the shaft has a slanted groove that matches the slanted groove opening.

[0009] In the aforementioned modular tooling fixture quick-change positioning mechanism, the side wall of the working chamber is provided with a fixed ear, and the fixed ear is provided with a fixed shaft; the fastening side support is provided with a movable groove that cooperates with the fixed shaft.

[0010] In the aforementioned modular tooling fixture quick-change positioning mechanism, the snap-fit ​​side support includes a main support body that is hinged to the sleeve body, the movable groove is provided on the main support body, and the upper end of the main support body has a hook portion that abuts against the surface of the positioning plate.

[0011] In the aforementioned modular tooling fixture quick-change positioning mechanism, the rotary positioning component includes a sleeve body disposed on the base of the auxiliary fixture. A rotary pressing rod is threadedly connected inside the sleeve body. Multiple movable positioning balls are evenly arranged around the bottom of the sleeve body along its axis. The bottom of the rotary pressing rod abuts against the positioning balls, and the rotary pressing rod controls the positioning balls to protrude outward. Multiple arc-shaped blocks are provided at the bottom connection hole of the worktable, and the positioning balls fit into the ball grooves on the inner side of the arc-shaped blocks.

[0012] In the aforementioned modular tooling fixture quick-change positioning mechanism, the rotating pressing rod includes a rod body connected to the sleeve body via a threaded structure, one end of the rod body has a ball, and the ball abuts against the positioning ball; a spring is sleeved on the rod body, and one end of the spring abuts against one end of the rod body.

[0013] Compared with the prior art, the present invention has the following advantages: 1. In this invention, the main fixture is quickly aligned with the positioning pin and positioning hole, and the cylinder-driven snap-fit ​​side supports achieve quick locking or unlocking. The auxiliary fixture is easily disassembled and assembled with the help of a rotating positioning component. A quick-change structure is set for each fixture unit, which reduces the difficulty of movement during replacement and improves the efficiency of changeover. When the main fixture is positioned, the positioning hole at the bottom of the main fixture is aligned with the positioning pin on the worktable. The positioning plates on both sides of the main fixture are mounted on the main body block. The snap-fit ​​side supports pass through the round hole. The positioning cylinder drives the guide rod to move forward, causing the linkage shaft to move downward. The snap-fit ​​side supports on both sides of the linkage shaft swing and move downward, pressing against the upper surface of the positioning plate to form a lock. With the limiting effect of the fixed shaft and the movable groove, a through-type rigid fixing structure is formed, which effectively resists the vibration and impact during the welding process, avoids positioning deviation, improves the stability of the fixture after installation, and ensures the positioning accuracy of the sheet metal parts during welding.

[0014] 2. In the rotating positioning component, the rotating pressing rod controls the positioning ball to precisely fit with the ball groove of the arc block. The positioning balls, which are evenly distributed at multiple points, form a ring-shaped positioning. Compared with the traditional bolt connection, which requires rotating the screw multiple times, this simplifies the operation process and ensures the stability of the installation.

[0015] 3. A short pin is provided in the countersunk hole on the main block. The short pin forms a lower support for the positioning plate on the side of the main clamp, so that the positioning plate remains horizontal after placement, and avoids the positioning plate from warping or tilting due to its own weight or placement deviation, and ensures that the round hole on the positioning plate can be accurately aligned with the fastening side support. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the positioning plate; Figure 3 This is a schematic diagram of the linkage shaft; Figure 4 A schematic diagram of the fixed ear; Figure 5 This is a schematic diagram of an inclined groove; Figure 6 This is a schematic diagram of the guide rod; Figure 7 This is a schematic diagram of the sleeve body; Figure 8 This is a schematic diagram of a rotary positioning component; Figure 9 This is a schematic diagram of an arc-shaped block.

[0017] Explanation of markings in the attached diagram: 1-Main clamp, 2-Secondary clamp, 3-Positioning pin, 4-Positioning hole, 5-Main body block, 6-Positioning cylinder, 7-Guide rod, 8-Working chamber, 9-Linkage shaft, 10-Snap-on side support, 11-Positioning plate, 12-Round hole, 13-Rotating positioning component, 14-Countersunk hole, 15-Short pin, 16-Main shaft, 17-Sleeve, 18-Extension piece, 19-Main rod, 20-End head, 21-Slanted groove, 22-Slanted groove, 23-Fixed ear, 24-Fixed shaft, 25-Modible groove, 26-Main support, 27-Hook part, 28-Sleeve body, 29-Rotating pressing rod, 30-Positioning ball, 31-Arc block, 32-Rod, 33-Sphere, 34-Spring, 35-Worktable. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0019] Example: A modular tooling fixture quick-change positioning mechanism, including a main fixture 1 and a secondary fixture 2 mounted on a worktable 35, as shown in the attached diagram. Figure 1 As shown, the main clamp and auxiliary clamp are mainly for welding long strip-shaped sheet metal parts. Two sets of auxiliary clamps are arranged on both sides of the main clamp. After the sheet metal part is clamped and positioned by the main and auxiliary clamps, the ends of the sheet metal part are fitted together, and then welded by the welding mechanism. The worktable serves as a general-purpose installation base module, while the main and auxiliary clamps are replaceable functional clamping modules. Both are equipped with dedicated quick-change positioning structures, allowing for independent assembly and disassembly from the worktable without the need for overall handling or replacement of base components. The worktable 35 is equipped with multiple positioning pins 3, four in total, evenly distributed on the worktable. The bottom of the main clamp 1 has positioning holes 4 that mate with the positioning pins 3. The main clamp connects to the positioning pins 3 via positioning holes 4. With the engagement of the positioning holes, the main fixture achieves initial horizontal positioning. The worktable 35 is equipped with a main body block 5 and a positioning cylinder 6. The main body block is primarily connected to the worktable via bolts, and the positioning cylinder is primarily secured by a U-shaped fastener. The extended end of the positioning cylinder 6 is connected to a guide rod 7 located within the main body block 5. The main body block 5 contains a working chamber 8, within which a linkage shaft 9 is installed. The guide rod 7 passes through the end of the linkage shaft 9 and controls its longitudinal displacement. A latching side support 10 is hinged to the side of the linkage shaft 9, and the latching side support 10 is connected to the inner wall of the working chamber 8 via a limiting structure. The main fixture 1 has a positioning plate 11 on its side, as shown in the attached figure. Figure 2As shown, the positioning plate 11 has a circular hole 12, and the fastening side support 10 passes through the circular hole 12 and abuts against the upper surface of the positioning plate 11; the bottom of the auxiliary clamp 2 has a rotating positioning component 13, and the auxiliary clamp 2 is connected to the worktable 35 via the rotating positioning component 13. The upper surface of the main block 5 is provided with multiple countersunk holes 14, and short pins 15 for supporting the positioning plate 11 are provided in the countersunk holes 14. The short pins directly provide lower support to the positioning plate on the side of the main clamp, so that the positioning plate remains horizontal after placement, and avoids the positioning plate from warping or tilting due to its own weight or placement deviation, ensuring that the circular hole on the positioning plate can be accurately aligned with the fastening side support.

[0020] The linkage shaft 9 includes a main shaft 16, as shown in the attached figure. Figure 3 As shown, a sleeve 17 is mounted on the main shaft 16. After the sleeve is fitted onto the main shaft, a double nut is screwed onto the end of the main shaft for fixation. The side of the sleeve 17 has an extension piece 18, and the fastening side support 10 is hinged to the extension piece 18. The end of the main shaft 16 cooperates with the guide rod 7. The guide rod 7 includes a main rod 19 connected to the extended end of the positioning cylinder 6, as shown in the attached figure. Figure 6 As shown, the end of the main rod 19 has an end head 20, and the end head 20 has a slanted groove 21; the end of the main shaft 16 has a slanted groove 22, as shown in the attached figure. Figure 5 As shown, the inclined groove 22 fits into the inclined groove opening 21, and the main shaft and the guide rod abut against each other through an inclined surface structure, realizing the vertical displacement of the main shaft. The structure is simple and the transmission is stable. A transverse channel is provided inside the main block, which is used to set the guide rod. An inner groove connected to the channel is provided longitudinally in the main block, and the end of the main shaft is set in the inner groove. The channel is divided into a small diameter channel and a large diameter channel by the inner groove. The front end of the end head has a shaft segment adapted to the small diameter channel, and the main body of the end head is adapted to the large diameter channel. This structure can ensure the smooth displacement of the guide rod as a whole in the channel. The side wall of the working chamber 8 is provided with a fixing lug 23, as shown in the attached figure. Figure 4 As shown, a fixed shaft 24 is provided on the fixed ear 23; a movable groove 25 that cooperates with the fixed shaft 24 is provided on the snap-fit ​​side support 10. The movable groove is an arc-shaped structure. The fixed shaft limits the snap-fit ​​side support. The snap-fit ​​side support 10 includes a main support 26 that is hinged to the sleeve 17. The movable groove 25 is provided on the main support 26. The upper end of the main support 26 has a hook 27. The hook 27 abuts against the surface of the positioning plate 11. When the main body moves downward, the hook will swing outward through the cooperation of the fixed shaft and the movable groove, and the hook will abut against the surface of the positioning plate. When the main body moves upward, the hook of the snap-fit ​​side support will retract inward, so that the positioning plate can be disengaged from the snap-fit ​​side support without interference.

[0021] The rotary positioning component 13 includes a sleeve body 28 disposed on the base of the auxiliary clamp 2, as shown in the attached figure. Figure 7As shown, the sleeve body includes a main body with a head at the upper end, which is welded to the base of the auxiliary clamp. A rotating pressing rod 29 is threadedly connected inside the sleeve body 28, as shown in the attached diagram. Figure 8 As shown, the top of the rotary pressing rod has a polygonal groove, which is hexagonal. An Allen wrench is inserted into this groove, causing the rotary pressing rod to rotate. Multiple movable positioning balls 30 are evenly installed around the bottom of the sleeve body 28 along its axis. The bottom of the rotary pressing rod 29 abuts against the positioning balls 30, and the rotary pressing rod 29 controls the positioning balls 30 to protrude outwards. There are three positioning balls, evenly arranged around the axis of the rotary pressing rod. Multiple arc-shaped blocks 31 are provided at the bottom connection hole of the worktable 35, as shown in the attached diagram. Figure 9 As shown, the positioning ball 30 fits into the ball groove on the inner side of the arc-shaped block 31, which is installed on the bottom of the worktable by screws. The rotating pressing rod 29 includes a rod body 32 connected to the sleeve body 28 via a threaded structure. One end of the rod body 32 has a ball 33, which abuts against the positioning ball 30. A spring 34 is fitted on the rod body 32, with one end of the spring 34 abutting against one end of the rod body 32. The spring on the rotating pressing rod can generate a preload force on the rod body, buffering the vibration and impact during the welding process, preventing the positioning ball from loosening due to vibration, effectively resisting external force interference during welding, preventing the sub-clamp from shifting or loosening, and ensuring the structural stability of the sub-clamp after installation. The rotary positioning component adopts a manual operation structure with threaded drive and telescopic positioning ball. It does not require complex tools and automated drive components. By simply rotating the pressing rod, the threaded drive can drive the bottom ball to press against or release the positioning ball, so that the positioning ball can protrude outward or retract inward within the sleeve body, thereby quickly completing the engagement, locking and unlocking with the arc-shaped ball groove of the worktable.

[0022] The working principle of this invention is as follows: When replacing the main clamp 1, align the positioning hole 4 at the bottom of the main clamp 1 with the positioning pin 3 on the surface of the worktable 35, and lower the main clamp 1 vertically. Through the clearance fit between the positioning pin 3 and the positioning hole 4, the main clamp 1 is initially limited in the horizontal direction. At the same time, the positioning plates 11 on both sides of the main clamp 1 are naturally mounted on the short pins 15 of the main body block 5. The short pins 15 provide lower support for the positioning plates 11, ensuring that the positioning plates 11 remain horizontal. The round holes 12 on the positioning plates 11 are precisely aligned with the snap-fit ​​side supports 10 inside the main body block 5, preparing for subsequent locking. The positioning cylinder 6 is activated, and the extended end of the positioning cylinder 6 pushes the guide rod 7 to move horizontally along the transverse channel of the main body block 5. The inclined groove 21 at the end of the guide rod 7 and the inclined groove 22 at the end of the linkage shaft 9 are aligned. With the guide rod 7 advancing horizontally, the inclined plane transmission converts the horizontal force into a longitudinal driving force, causing the linkage shaft 9 to move vertically downward along the working chamber 8. The extension plates 18 on both sides of the linkage shaft 9 move downward synchronously, pulling the fastening side support 10 through the hinge point. The movable groove 25 on the fastening side support 10 forms a limiting fit with the fixed shaft 24 on the inner wall of the working chamber 8, causing the fastening side support 10 to swing around the fixed shaft 24 as the fulcrum. The hook part 27 at its upper end swings outward and passes through the round hole 12 of the positioning plate 11. Finally, the hook part 27 presses tightly against the upper surface of the positioning plate 11. When the main clamp 1 needs to be replaced, the positioning cylinder 6 is reset, the guide rod 7 retracts in the opposite direction along the transverse channel, and the linkage shaft 9 resets upward after losing the inclined plane driving force, driving the fastening side support 10. The hook 27 retracts inward, releasing its pressure constraint on the positioning plate 11; at this time, the main clamp 1 can be lifted directly upward, the positioning hole 4 separates from the positioning pin 3, and the main clamp 1 is quickly disassembled; the auxiliary clamp 2 is moved to the preset installation position of the worktable 35, so that the sleeve body 28 at the bottom of the auxiliary clamp 2 is aligned with the bottom connection hole of the worktable 35, ensuring that the sleeve body 28 and the arc block 31 are in corresponding positions, leaving space for the positioning ball 30 to fit with the ball groove, and using a tool to insert into the polygonal groove at the top of the rotating pressing rod 29, and rotating the rotating pressing rod 29 clockwise; since the rotating pressing rod 29 and the sleeve body 28 are connected by threads, the thread drive drives the rotating pressing rod 29 to move vertically downward along the sleeve body 28, and the ball 33 at its bottom gradually presses against the sleeve body 28. The positioning ball 30 at the bottom; as the rotating pressing rod 29 continues to move downward, the ball 33 generates a radial thrust on the positioning ball 30, causing the positioning ball 30 to protrude outward along the radial direction of the sleeve body 28, and finally precisely fit with the ball groove on the inner side of the arc block 31 at the bottom of the worktable 35. The bottom of the sleeve body is provided with a groove to accommodate the positioning ball, and the positioning ball is embedded in the groove. The groove can restrict the positioning ball, causing part of the positioning ball to protrude. Reverse rotation of the rotating pressing rod 29 causes the threaded drive to move it upward, the pressure of the ball 33 on the positioning ball 30 disappears, and the positioning ball 30 retracts inward under the restoring force of the spring 34 and its own gravity, disengaging from the ball groove of the arc block 31. At this time, the sub-clamp 2 can be lifted directly upward to complete the quick disassembly and replacement of the sub-clamp 2.

[0023] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. Furthermore, in these embodiments, "up," "down," "left," "right," "front," and "back" represent relative positions only, not absolute positions. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A quick-change positioning mechanism of a modular tooling fixture, comprising a main fixture (1) and a sub fixture (2) arranged on a worktable (35), characterized in that: The workbench (35) is provided with multiple positioning pins (3), and the bottom of the main clamp (1) is provided with positioning holes (4) that fit with the positioning pins (3); the workbench (35) is provided with a main body block (5) and a positioning cylinder (6), the extended end of the positioning cylinder (6) is connected to a guide rod (7) provided in the main body block (5), the main body block (5) has a working chamber (8), the working chamber (8) is provided with a linkage shaft (9), the guide rod (7) passes through the end of the linkage shaft (9), and the guide rod (7) is used to control the linkage shaft (9). Longitudinal displacement; the linkage shaft (9) is symmetrically hinged with a snap-fit ​​side support (10), which is connected to the inner wall of the working chamber (8) via a limiting structure; the main clamp (1) has a positioning plate (11) on its side, which has a round hole (12) on the positioning plate (11), and the snap-fit ​​side support (10) passes through the round hole (12) and abuts against the upper surface of the positioning plate (11); the auxiliary clamp (2) has a rotating positioning component (13) at its bottom, and the auxiliary clamp (2) is connected to the worktable (35) via the rotating positioning component (13).

2. The modular tooling fixture quick-change positioning mechanism according to claim 1, characterized in that: The upper surface of the main block (5) is provided with a plurality of countersunk holes (14), and short pins (15) for supporting the positioning plate (11) are provided in the countersunk holes (14).

3. The modular tooling fixture quick-change positioning mechanism according to claim 1, characterized in that: The linkage shaft (9) includes a main shaft (16), a sleeve (17) is provided on the main shaft (16), and an extension piece (18) is provided on the side of the sleeve (17). The fastening side support (10) is hinged to the extension piece (18). The end of the main shaft (16) is engaged with the guide rod (7).

4. The modular tooling fixture quick-change positioning mechanism according to claim 3, characterized in that: The guide rod (7) includes a main rod (19) connected to the extended end of the positioning cylinder (6), the end of the main rod (19) has an end head (20), and the end head (20) has a slanted groove (21); the end of the main shaft (16) has a slanted groove (22), and the slanted groove (22) matches the slanted groove (21).

5. The modular tooling fixture quick-change positioning mechanism according to claim 1, characterized in that: The working chamber (8) is provided with a fixed ear (23) on its side wall, and a fixed shaft (24) is provided on the fixed ear (23); the fastening side support (10) is provided with a movable groove (25) that cooperates with the fixed shaft (24).

6. The modular tooling fixture quick-change positioning mechanism according to claim 5, characterized in that: The fastening side support (10) includes a main support (26) hinged to the sleeve (17), the movable groove (25) is provided on the main support (26), the upper end of the main support (26) has a hook (27), and the hook (27) abuts against the surface of the positioning plate (11).

7. The modular tooling fixture quick-change positioning mechanism according to claim 1, characterized in that: The rotating positioning component (13) includes a sleeve body (28) set on the base of the auxiliary clamp (2). A rotating pressing rod (29) is threadedly connected inside the sleeve body (28). A plurality of movable positioning balls (30) are evenly arranged around the bottom of the sleeve body (28) along its axis. The bottom of the rotating pressing rod (29) abuts against the positioning balls (30), and the rotating pressing rod (29) controls the positioning balls (30) to protrude outward. A plurality of arc-shaped blocks (31) are provided at the bottom connection hole of the worktable (35). The positioning balls (30) fit into the ball grooves on the inner side of the arc-shaped blocks (31).

8. The modular tooling fixture quick-change positioning mechanism according to claim 7, characterized in that: The rotating pressing rod (29) includes a rod (32) connected to the sleeve body (28) via a threaded structure. One end of the rod (32) has a ball (33) that abuts against a positioning ball (30). A spring (34) is fitted on the rod (32), and one end of the spring (34) abuts against one end of the rod (32).

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