MCCB assembly tapping die

Abstract

The invention relates to the technical field of tapping equipment, and discloses an MCCB assembly tapping die which comprises an upper die and a lower die, a first base plate is arranged on the lower die, and a cushion block and a second base plate are sequentially installed on the first base plate; a first sealing box is fixedly mounted on the second base plate, and a gear set and a screw tap are arranged in the first sealing box; a second sealing box is fixedly installed on the first base plate, a lead screw is fixedly installed on the face, close to the lower die, of the upper die, a shaft sleeve correspondingly matched with the lead screw is rotatably installed in the second sealing box, and a guide pin is fixedly installed on the inner wall of the shaft sleeve and embedded in a threaded groove of the lead screw. The protruding long tooth part of the high-position transmission gear is in axial sliding engagement with the adjacent gear, the height deviation generated by the upper die and the lower die can be automatically absorbed, and the influence of equipment vibration on the tapping process is remarkably reduced.

Description

Technical Field

[0001] This invention relates to the field of tapping equipment technology, specifically to a tapping die for an MCCB component. Background Technology

[0002] In the manufacturing process of molded case circuit breakers (MCCBs), tapping dies serve as key tooling equipment, used to machine internal threaded holes in the plastic or metal housing of the MCCB assembly to enable the fastening connection of screws during subsequent assembly. Traditional MCCB assembly tapping dies mostly adopt an integral structure design, that is, the upper and lower dies are integrated within the same rigid frame, and the mold closing and demolding actions are achieved through guide pillars, springs, or other mechanical structures.

[0003] However, in actual production applications, this type of integral tapping die has significant technical drawbacks. First, due to the high rigidity of the die, it is highly susceptible to mechanical vibrations or impact loads generated during frequent upper and lower mold-closing operations on high-speed automated assembly lines. This can lead to tapping position misalignment, decreased thread accuracy, and even quality problems such as stripped or damaged threads, severely impacting the assembly reliability and electrical safety of MCCB products. Second, the integral structure hinders die maintenance and replacement. If any part (such as the tapping head, locating pin, or guide sleeve) wears or is damaged, it often requires complete disassembly or even replacement of the entire set, extending downtime and significantly increasing manufacturing costs.

[0004] To overcome the above problems, there is an urgent need for a new type of tapping die that can effectively isolate external vibration interference while ensuring high-precision tapping, and improve the modularity and maintainability of the die. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a tapping die for MCCB components.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A tapping die for an MCCB component includes an upper die and a lower die. A first pad is provided on the lower die. A pad block and a second pad block are sequentially mounted on the first pad block via bolts, forming a tapping space between the second pad block and the first pad block. A first sealing box is fixedly mounted on the second pad block, and a gear set is provided inside the first sealing box. A tap is mounted on the gear set, extending into the tapping space. A lead screw is fixedly mounted on the side of the upper die near the lower die. A second sealing box is fixedly mounted on the first pad block, and a bushing corresponding to the lead screw is rotatably mounted inside the second sealing box. A guide pin is fixedly mounted on the inner wall of the bushing, embedded in the threaded groove of the lead screw. A gear ring is fixedly mounted on the outer circumference of the bushing, meshing with the gear set.

[0007] To construct a power transmission link with adaptive compensation capability, preferably, the gear set includes at least one high-position transmission gear, the teeth of which protrude vertically from the other gears in the gear set; the gear ring is slidably engaged with the high-position transmission gear.

[0008] To address the issue of lateral swaying during high-speed continuous feeding of the material strip, which can lead to deviations in the coaxiality of the tapping, preferably, a first limiting plate and a second limiting plate are symmetrically mounted on the first pad. The first limiting plate and the second limiting plate are located within the tapping space, and a first clearance groove is provided on the first limiting plate.

[0009] To prevent metal chips generated during tapping from accumulating near the limiting plate, scratching the product surface, or clogging the mold, the first pad is further provided with a chip removal groove on the side near the first limiting plate. The chip removal groove extends along the length of the material strip, and a second clearance groove is provided through the chip removal groove.

[0010] To overcome the drawbacks of traditional mechanical positioning mechanisms, such as slow response speed, inability to adapt to high-speed stamping cycles, and the need to stop the machine to replace the physical cam plate when adjusting the positioning timing, preferably, the tapping die also includes a cylinder, which is fixedly installed in the lower die. A floating plate is fixedly installed on the movable end of the cylinder, and a positioning pin is fixedly installed on the floating plate. A positioning through hole is correspondingly opened on the first pad, and the positioning pin extends into the positioning through hole to hold the material strip.

[0011] In order to achieve precise synchronization between the mold movement and the rotation angle of the pressure equipment spindle, the cylinder is further connected to an electromagnetic reversing valve, which is provided with an external signal input terminal for receiving the synchronization stroke signal of the external pressure equipment. The external pressure device is one of a punch press, a hydraulic press, or a servo press.

[0012] The beneficial effects of this invention are: 1. By adopting a split mold structure, the high-position transmission gear with its protruding long teeth forms an axial sliding mesh with the adjacent gear, which can automatically absorb the height deviation generated by the upper and lower molds. This not only significantly reduces the impact of equipment vibration on the tapping process, but also facilitates local replacement, debugging and standardized management, thereby improving production efficiency, product consistency and equipment utilization.

[0013] 2. By directly receiving the electronic cam synchronous stroke signal from the punch press, hydraulic press or servo press through the electromagnetic reversing valve, the microsecond-level precise matching between the positioning pin action and the spindle rotation angle is achieved. This allows the positioning pin to quickly insert and lock at the moment the feeding ends and immediately retract and release after tapping is completed. It perfectly adapts to the high-speed stamping rhythm of hundreds of times per minute and eliminates the inertial lag and wear problems of the mechanical cam mechanism. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 A structural diagram excluding the upper mold; Figure 3 This is a schematic diagram of the internal structure of the first and second sealing boxes of the present invention; Figure 4 This is a schematic diagram of the tap mounting position structure of the present invention; Figure 5 This is a schematic diagram of the lead screw mounting position structure of the present invention; Figure 6 for Figure 2 Enlarged view of the A-structure; Figure 7 For existing MCCB component tapping dies; Figure 8 For processing material strips.

[0015] The attached diagram lists the components represented by each number as follows: 10. Upper mold; 11. Lead screw; 20. Lower mold; 21. First pad; 211. First limiting plate; 202. First clearance groove; 203. Chip removal groove; 204. Second clearance groove; 205. Positioning through hole; 212. Second limiting plate; 22. Pad block; 23. Second pad; 24. First sealing box; 241. Gear set; 201. High-position transmission gear; 242. Tap; 25. Second sealing box; 251. Bushing; 252. Guide pin; 253. Gear ring; 30. Cylinder; 31. Floating plate; 32. Positioning pin. Detailed Implementation

[0016] 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.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., 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 invention 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 limitations on this invention. Example 1

[0018] like Figure 1 - Figure 8 As shown, this invention relates to a tapping die for MCCB components, mainly used in the automatic tapping process of metal strip in the production of molded case circuit breaker components. It includes an upper die 10 and a lower die 20, which are installed together on an external pressure device, such as a punch press or a servo press between the slider and the worktable. In this embodiment, the external pressure device is preferably a punch press, which has a built-in electronic cam control system for real-time monitoring of the angle position of the punch press spindle and generating a high-precision synchronous trigger signal according to a preset motion curve. A first pad 21 is provided on the lower die 20, which serves as a basic support platform. A pad block 22 and a second pad plate 23 are sequentially stacked on its upper surface by bolts. The pad block 22 serves as a height adjustment and support function, and the second pad plate 23 covers the pad block 22. It is worth noting that the second pad plate 23 and the first pad plate 21 enclose a tapping space. This space not only provides a stroke margin for the reciprocating motion of the tap 242, but also serves as an area to accommodate the strip to be processed and to discharge metal chips.

[0019] To achieve efficient and sealed tapping operations, this embodiment designs a dual-transmission structure. Specifically, a first sealing box 24 is fixedly installed on the second pad 23, and a gear set 241 is provided inside the first sealing box 24. A tap 242 is installed vertically downward at the output end of the gear set 241, and the lower end of the tap 242 extends into the tapping space and acts directly on the material strip. A second sealing box 25 is fixedly installed on the first pad 21. A lead screw 11 is fixedly installed on the side of the upper mold 10 near the lower mold 20. A bushing 251 corresponding to the lead screw 11 is rotatably installed inside the second sealing box 25. A guide pin 252 is fixedly installed on the inner wall of the bushing 251 and is embedded in the threaded groove of the lead screw 11. A gear ring 253 is fixedly installed on the outer circumference of the bushing 251 and meshes with the gear set 241, thereby transmitting the rotational motion of the bushing 251 to the gear set 241.

[0020] During operation, the external automated feeding mechanism feeds the metal strip of the MCCB component into the tapping space along the feeding channel on the first pad 21. At this time, the upper die 10 is in the upper position, the lead screw 11 is at the starting point of the stroke, and the tap 242 is suspended above the strip. An external pressure device drives the upper mold 10 to move downward. As the upper mold 10 moves downward, the lead screw 11 fixed on it is inserted into the bushing 251 of the second sealing box 25. Since the guide pin 252 is stuck in the thread groove of the lead screw 11, the continued downward movement of the lead screw 11 forces the bushing 251 to rotate around its axis. The toothed ring 253 on the outer circle of the bushing 251 rotates accordingly, driving the gear set 241 meshing with it to rotate. The gear set 241 drives the tap 242 at the end to rotate at high speed. At the same time, the upper mold 10 continues to move downward, pushing the entire lower mold 20 assembly to press the material strip. Under the action of axial pressure, the rotating tap 242 cuts into the pre-made hole of the material strip or directly taps the solid material to form an internal thread.

[0021] After tapping is completed, the external pressure device drives the upper mold 10 to return upward, and the lead screw 11 moves upward. Through the principle of the screw pair, the bushing 251 is driven to rotate in the opposite direction. The power is transmitted step by step through the gear ring 253, the bushing 251, and the gear set 241, which drives the tap 242 to rotate in the opposite direction. Under the action of the reverse force, the tap 242 is screwed out from the pre-machined threaded hole, completing the demolding action and avoiding damage to the thread profile by forcibly pulling it out.

[0022] In this embodiment, to accommodate the slight height deviation that may occur between the upper mold 10 and the lower mold 20 during the closing process, and to ensure the continuity and stability of power transmission, a special axial floating meshing design is adopted between the gear set 241 and the gear ring 253, referring to... Figure 3 The gear set 241 includes at least one high-position transmission gear 201, which is located at a key node in the transmission chain of the gear set 241, preferably at the input end. Compared to other auxiliary gears in the gear set 241, the teeth of the high-position transmission gear 201 protrude vertically from the other gears in the gear set 241, thereby forming a long-tooth meshing area. The toothed ring 253 slides and meshes with the high-position transmission gear 201. In the closed state of the mold, the toothed section of the high-position transmission gear 201 meshes with the upper toothed section of the corresponding meshing gear. Because the high-position transmission gear 201 has an additional axial tooth length, when the upper mold 10 drives the toothed ring 253 to move vertically, the meshing point of the two gears will slide relative to each other in the tooth length direction, but will always remain within the effective meshing range, and there will be no tooth disengagement or jamming.

[0023] An appropriate axial clearance is reserved between the non-working tooth surface of the high-position transmission gear 201 and the corresponding meshing gear, allowing the two to slide relative to each other in the vertical direction, while ensuring smooth transmission of rotational motion through the gear backlash.

[0024] Reference Figure 2 and Figure 6 Furthermore, a first limiting plate 211 and a second limiting plate 212 are symmetrically installed on the first pad 21. The first limiting plate 211 and the second limiting plate 212 are located in the tapping space, and the distance between them is slightly larger than the width of the strip. Usually, a gap of 0.02mm-0.05mm is reserved to form a narrow strip guide channel, which mainly restricts the lateral displacement of the strip in the horizontal plane and ensures that the hole to be processed on the strip is always concentric with the axis of the tap 242. A first clearance groove 202 is provided on the first limiting plate 211. The groove is a U-shaped notch, which is designed to provide a dedicated clearance space for the lead screw 11.

[0025] The first pad 21 has a chip removal groove 203 on the side near the first limiting plate 211. The chip removal groove 203 extends along the length of the material belt, and a second clearance groove 204 is provided through the chip removal groove 203.

[0026] The automated feeder feeds the MCCB component strip into the guide channel between the first limiting plate 211 and the second limiting plate 212. Due to the symmetrical clamping effect of the first limiting plate 211 and the second limiting plate 212, the strip is forced to move on a straight track. When the tap 242 rotates and cuts into the strip to tap, it will generate continuous spiral metal chips. Under the action of gravity and cutting force, most of the chips will fall naturally into the second clearance groove 204 below. Example 2

[0027] Reference Figure 1 and Figure 6 The tapping die also includes a cylinder 30, which is fixedly installed inside the lower die 20. The cylinder axis is set perpendicular to the horizontal plane. A floating plate 31 is fixedly installed on the movable end of the cylinder 30, and its movement trajectory is restricted to the vertical direction. A positioning pin 32 is fixedly installed on the floating plate 31. The top of the positioning pin 32 can be designed as a cone to fit the pre-made hole on the MCCB component strip. A positioning through hole 205 is correspondingly opened on the first pad 21. The positioning pin 32 extends into the positioning through hole 205 to hold the strip.

[0028] The air circuit of cylinder 30 is connected to an electromagnetic directional valve, which controls the entry of compressed air into the rodless or rod chamber of cylinder 30, thereby driving the extension or retraction of the piston rod. The electromagnetic directional valve has an external signal input terminal, typically a 24V DC level signal interface. This input terminal is directly connected to the controller output port of the external pressure equipment via a shielded cable. The internal pressure equipment is equipped with an electronic cam. When the spindle rotates to a preset specific angle range, the controller automatically outputs a high-level synchronization signal; when the spindle rotates to the point where tapping is complete and it is ready to descend, it outputs a low-level signal to receive the synchronization stroke signal from the external pressure equipment. The external pressure equipment is one of a punch press, a hydraulic press, or a servo press.

[0029] During the feeding stage, when the spindle of the external pressure equipment is in the tapping stroke or the slide is in the upward movement stage, the electronic cam system outputs a "reset signal", the magnetic reversing valve is activated, the air intake is cut off and the exhaust is completed, the piston rod of the drive cylinder 30 is retracted, the floating plate 31 is lowered accordingly, and the positioning pin 32 is completely withdrawn below the positioning through hole 205 of the first pad plate 21. At this time, there is no obstruction below the material strip, and the feeder can freely feed the material strip of the next station into the mold, avoiding friction or interference between the positioning pin 32 and the moving material strip; When the feeding action is completed and the spindle of the external pressure device rotates to a preset safety angle near the top dead center, the electronic cam system immediately outputs a "trigger signal." The electromagnetic reversing valve quickly switches, and compressed air enters the rodless chamber of cylinder 30, driving the piston rod to extend rapidly. The floating plate 31 rises instantly, pushing the positioning pin 32 through the positioning through hole 205 and precisely inserting it into the positioning hole on the strip. Due to the fast response speed of cylinder 30, the positioning pin 32 can firmly lock the strip in its current position in a very short time, eliminating the cumulative feeding error and ensuring that the hole to be tapped is concentric with the tap 242. Throughout the entire process of tap 242 descending to contact the strip and performing tapping, cylinder 30 always maintains air supply and pressure, and the positioning pin 32 continuously holds the strip. This effectively counteracts the lateral force generated by the tapping torque, preventing the strip from rotating or shifting slightly during processing and ensuring thread quality.

[0030] After tapping is completed and tap 242 is completely removed from the feed strip, the spindle continues to rotate and approaches the starting point of the next feeding cycle. The electronic cam signal flips, cylinder 30 retracts again, positioning pin 32 disengages from the feed strip, and the system returns to stage one to start the next cycle.

[0031] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A tapping die for an MCCB component, comprising an upper die (10) and a lower die (20), characterized in that, The lower mold (20) is provided with a first pad (21), and a pad block (22) and a second pad plate (23) are installed on the first pad plate (21) in sequence by bolts. The second pad plate (23) and the first pad plate (21) enclose a tapping space. A first sealing box (24) is fixedly installed on the second pad (23). A gear set (241) is provided inside the first sealing box (24). A tap (242) is installed on the gear set (241). The tap (242) extends into the tapping space. A lead screw (11) is fixedly installed on the side of the upper mold (10) near the lower mold (20). A second sealing box (25) is fixedly installed on the first pad (21). A bushing (251) corresponding to the lead screw (11) is rotatably installed inside the second sealing box (25). A guide pin (252) is fixedly installed on the inner wall of the bushing (251). The guide pin (252) is embedded in the thread groove of the lead screw (11). A gear ring (253) is fixedly installed on the outer circular surface of the bushing (251). The gear ring (253) meshes with the gear set (241).

2. The MCCB component tapping die according to claim 1, characterized in that: The gear set (241) includes at least one high-position transmission gear (201), the teeth of which protrude vertically from the other gears of the gear set (241); The gear ring (253) is in sliding engagement with the high-position transmission gear (201).

3. The MCCB component tapping die according to claim 1, characterized in that: A first limiting plate (211) and a second limiting plate (212) are fixedly installed on the first pad (21). The first limiting plate (211) and the second limiting plate (212) are located in the tapping space. A first clearance groove (202) is opened on the first limiting plate (211).

4. The MCCB component tapping die according to claim 3, characterized in that: The first pad (21) has a chip removal groove (203) on the side near the first limiting plate (211). The chip removal groove (203) extends along the length of the material belt, and a second clearance groove (204) is provided through the chip removal groove (203).

5. The MCCB component tapping die according to claim 1, characterized in that: The tapping die also includes a cylinder (30), which is fixedly installed in the lower die (20). A floating plate (31) is fixedly installed on the movable end of the cylinder (30). A positioning pin (32) is fixedly installed on the floating plate (31). A positioning through hole (205) is correspondingly opened on the first pad (21). The positioning pin (32) extends into the positioning through hole (205) to hold the material strip.

6. The MCCB component tapping die according to claim 5, characterized in that: The cylinder (30) is connected to an electromagnetic reversing valve, which is provided with an external signal input terminal for receiving the synchronous stroke signal of an external pressure device. The external pressure device is one of a punch press, a hydraulic press, or a servo press.

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