Self-centering clamping and quick-change positioning die for vertical punching machine

Abstract

The utility model discloses a utility model provides a kind of self-centering clamping and quick-change positioning mould for vertical puncher, including the mould base of being fixed on vertical puncher stamping platform, quick-change clamping column being detachably installed on mould base and driving mechanism being installed below mould base, mould base is equipped with mounting hole, positioning slot and through-hole, quick-change clamping column includes positioning base and elastic clamping part, positioning base is equipped with positioning pin, and elastic clamping part is equipped with axial slit and conical inner hole, and driving mechanism includes conical ejector rod, and conical ejector rod passes through through-hole and extends into conical inner hole.The mould is self-centered clamping of tubular sample by conical ejector rod and conical inner hole cooperation, and different inner diameter tubular sample is quickly adapted by quick-change clamping column, effectively solve the problem that the radial positioning of existing vertical puncher mould is unreliable, and the problem of low die changing efficiency is effectively solved, and punching precision and production efficiency are improved.

Description

Technical Field

[0001] This utility model relates to the field of mechanical processing equipment technology, and in particular to a self-centering clamping and quick-change positioning mold for a vertical punching machine. Background Technology

[0002] In the field of machining, pipes (such as stainless steel pipes and aluminum alloy pipes) are widely used in industrial production and daily life due to their lightweight, aesthetic appeal, strength, and durability, leading to a growing demand for pipe wall hole machining. Traditional pipe hole machining processes such as drilling and milling suffer from difficulties in machining irregularly shaped holes and low production efficiency, making them unsuitable for mass production scenarios. Therefore, the use of stamping processes for pipe hole machining has become the mainstream technological direction. A Chinese utility model patent applied for in 2023 (authorization announcement number CN219503540U, titled "A Vertical Punching Machine") discloses a targeted small vertical punching machine. The equipment includes a punching platform, a punching mechanism, and a punching die. The punching mechanism is installed above the punching platform, and the punching die is fixed on the punching platform and directly opposite the punching mechanism. The base of the punching die has a horizontally extending fixed column (integrated with the base, the cross-section can be cylindrical or rectangular). The fixed column has a vertical processing hole. During processing, a tubular sample is fitted onto the fixed column, and at the same time, a disc-shaped adjustment mechanism threaded to the base boss holds the sample end face, limiting the axial position of the sample to adjust the axial coordinate of the processing hole. In addition, a hole symmetry positioning mechanism with a telescopic rod structure is provided to ensure the coaxiality of the holes on both sides of the tube. This patent solves to some extent the problem of high correlation and poor versatility of "equipment-die-sample" in traditional tube punching processing, and realizes the adjustment of the axial position of the processing hole.

[0003] However, the stamping dies of the aforementioned vertical punching machine still have some problems in practical applications, failing to meet the requirements of high-precision and high-flexibility pipe processing. On the one hand, they lack reliable radial positioning and clamping functions. The sample is only assembled on the fixed column by "sleeving". To facilitate sample insertion, the inner diameter of the sample must be larger than the outer diameter of the fixed column, inevitably resulting in an assembly gap. During the high-speed impact of the punch, this gap can cause radial deflection, vibration, or displacement of the sample, which not only seriously affects the positional accuracy and roundness of the punch, but also causes burrs, tears, and other quality defects at the punch cut, while also aggravating the wear of the punch and die. On the other hand, the die changing efficiency is low. Since the fixed column and the base are an integral structure, when processing pipes with different inner diameter specifications, the entire stamping die must be completely disassembled and replaced from the stamping platform. This process is time-consuming (usually taking more than ten minutes or even half an hour), labor-intensive, and each reassembly of the die may introduce new alignment errors, seriously restricting the improvement of production efficiency and making it difficult to adapt to the flexible production requirements of alternating processing of multiple specifications of pipes. Utility Model Content

[0004] The technical problem to be solved by this utility model is that the existing stamping dies lack reliable radial positioning and clamping functions. The tubular sample is only "sleeved" on the integrated fixed column. There is an assembly gap between the inner diameter of the sample and the outer diameter of the fixed column. When the punch is stamped at high speed, it is easy to cause radial deflection, vibration or displacement of the sample, which in turn leads to poor punching position accuracy, poor hole roundness, burrs / tears on the punch cut, and aggravates the wear of the punch and the die.

[0005] The technical solution adopted by this utility model to solve its technical problem is: A self-centering clamping and quick-change positioning die for a vertical punching machine, comprising: The mold base is set on the punching platform of the vertical punching machine. The upper surface of the mold base has a mounting hole for assembling quick-change clamping columns. The side wall of the mounting hole has a positioning groove along the axial direction. The center of the mold base has a through hole, which is coaxial with the cylindrical mounting hole and allows the conical ejector rod to pass through. The quick-change clamping column is detachably assembled into the mounting hole. The quick-change clamping column includes a positioning base and an elastic clamping part. The outer diameter of the positioning base is adapted to the diameter of the mounting hole. The side wall of the positioning base is provided with a positioning pin that is inserted into the elongated positioning groove. The outer wall of the elastic clamping part is provided with at least one slit along the axial direction. The inner wall of the elastic clamping part is a tapered inner hole that opens upward. The side wall of the elastic clamping part is provided with a through-hole for the punch to pass through. The drive mechanism includes a tapered push rod adapted to the taper of the tapered inner hole. The tapered push rod includes a tapered head and a rod portion. The rod portion passes through the through hole and engages with the drive assembly below the mold base. The tapered head extends into the tapered inner hole to drive the expansion of the elastic clamping part.

[0006] Preferably, the positioning pin is a protruding structure adapted to the positioning groove, and the length of the positioning pin is not greater than the distance from the side wall of the positioning base to the bottom of the elongated positioning groove.

[0007] Preferably, the outer diameter of the elastic clamping part is smaller than the standard inner diameter of the tubular sample to be processed by a first preset difference, the first preset difference being 0.1-0.2 mm.

[0008] Preferably, the axis of the through hole corresponds to the movement direction of the punch in the punching mechanism of the vertical punching machine, and the diameter of the through hole is adapted to the outer diameter of the punch to allow the punch to pass through.

[0009] Preferably, the drive assembly includes a transmission component for driving the tapered push rod to move axially, the transmission component cooperating with the rod portion of the tapered push rod, and the drive assembly further includes an operating component connected to the lower end of the rod portion.

[0010] Preferably, the operating component is a handwheel or a torque wrench, and the operating component is detachably connected to the lower end of the rod.

[0011] Preferably, at least one slit is distributed circumferentially along the elastic clamping portion to allow the elastic clamping portion to expand uniformly when the conical push rod is driven.

[0012] Preferably, the outer diameter of the tapered top rod is adapted to the diameter of the through hole in the mold base to allow the rod to move axially along the through hole.

[0013] The beneficial effects of this utility model include the following: 1. By adapting the cylindrical mounting hole of the mold base to the positioning base of the quick-change clamping column, and the circumferential limiting fit between the positioning pin and the positioning groove, combined with the axial cutting of the elastic clamping part of the quick-change clamping column (forming an elastic clamping flap) and the conical surface drive of the conical push rod of the drive mechanism (the taper matches the conical inner hole), the self-centering clamping of the tubular sample and the elimination of the radial gap between the sample and the clamping part are achieved. This solves the problem that the existing stamping mold lacks reliable radial positioning and clamping functions, which leads to radial deflection and vibration of the sample during stamping, and in turn causes poor punching position accuracy, burrs / tears at the hole opening, and wear of the punch and the mold.

[0014] 2. By detachably assembling the quick-change clamping column with the mounting hole of the mold base, and with the quick centering structure of the positioning pin and positioning groove, it is possible to adapt to the processing needs of tubular samples with different inner diameters by simply replacing the quick-change clamping column. This solves the problem that the existing one-piece fixed column mold requires the entire mold to be disassembled to change the specifications, resulting in long mold change time, high labor intensity, and easy introduction of centering errors during reassembly.

[0015] 3. By coaxially engaging the tapered push rod in the drive mechanism with the through hole of the mold base, and by precisely contacting the tapered head with the tapered inner hole of the elastic clamping part, the axial driving force is stably converted into a uniform radial expansion force, ensuring that the elastic clamping petals uniformly grip the inner wall of the sample, solving the problem of sample centering deviation caused by clamping in one direction, and further improving the consistency of processing. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the self-centering clamping and quick-change positioning mold used in the vertical punching machine in Example 1; Figure 2 for Figure 1 Enlarged view of point a in the middle; Figure 3 This is a side view of the structure of the self-centering clamping and quick-change positioning mold used in the vertical punching machine in Example 1.

[0017] Reference numerals: 1. Mold base; 11. Cylindrical mounting hole; 12. Positioning groove; 2. Quick-change clamping post; 21. Positioning base; 22. Clamping part; 23. Positioning pin; 24. Elastic clamping flap; 25. Tapered inner hole; 26. Machining through hole; 3. Drive mechanism; 31. Tapered ejector rod; 32. Threaded bracket; 33. External threaded rod body; 34. Handwheel; 4. Stamping mechanism; 5. Sample. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, but these specific embodiments do not limit the scope of protection of the present invention in any way. Example

[0019] like Figure 1-3 As shown, a self-centering clamping and quick-change positioning mold for a vertical punching machine includes a mold base 1, a detachable quick-change clamping column 2, and a drive mechanism 3 for driving the clamping column 2 to achieve clamping. The mold is fixedly installed on the punching platform of the vertical punching machine, located below the punching mechanism 4, and is used to achieve positioning, clamping, and punching processing of tubular samples 5.

[0020] The mold base 1 has a rectangular structure and is fixed to the punching platform of the punching machine by bolts. A cylindrical mounting hole 11 is located at the center of its upper surface. The diameter of the cylindrical mounting hole 11 matches the outer diameter of the positioning base 21 of the quick-change clamping column 2. To ensure the repeatability and circumferential alignment of the quick-change clamping column 2 during installation, a horizontal positioning groove 12 is provided on the side wall of the mounting hole 11. The positioning groove 12 is elongated and is used to cooperate with the positioning pin 23 on the quick-change clamping column 2, ensuring that the clamping column 2 returns to the same position and orientation each time it is installed.

[0021] The mold base 1 has an installation space for the drive mechanism 3 below it, and a through hole is machined at its center. The rod of the tapered push rod 31 passes through the through hole and is used to drive the operation of the entire clamping system.

[0022] The quick-change clamping column 2 is a hollow cylinder, consisting of two main parts: a positioning base 21 and a clamping part 22. The positioning base 21, located at the lower part of the quick-change clamping column 2, is a short cylinder with an outer diameter matching the cylindrical mounting hole 11 on the mold base 1, ensuring accurate insertion of the clamping column 2 into the mounting hole 11 during installation. A positioning pin 23 is machined on the side wall of the positioning base 21, engaging with the positioning groove 12 of the mounting hole 11 on the mold base 1. When the quick-change clamping column 2 is inserted into the mold base 1, the positioning pin 23 automatically slides into the positioning groove 12, ensuring that the clamping column 2 does not rotate circumferentially during installation and that the direction of the through hole 26 on it remains consistent with the direction of the punch's movement. The positioning base 21 and the clamping part 22 maintain a structurally complete connection, together forming the entire quick-change clamping column 2.

[0023] The clamping part 22 is an elastic clamping part 24, which is located on the upper part of the quick-change clamping column 2. Its outer diameter is slightly smaller than the standard inner diameter of the sample 5 to be processed (about 0.1-0.2 mm smaller, so as to facilitate the insertion and removal of the sample 5).

[0024] Three to four vertical slits are uniformly machined along the axial direction of the outer wall of the elastic clamping part 24, forming multiple elastic clamping petals 24. These slits extend downward from the top of the column, but intentionally stop near the positioning base 21, without completely severing the connection between the elastic clamping part 24 and the positioning base 21, thus ensuring the connectivity and structural integrity of the entire quick-change clamping column 2. The elastic clamping petals 24 are symmetrically distributed, typically using a configuration of three to four slits, so that under the drive of the conical top rod 31, each clamping petal 24 can expand outward uniformly and synchronously, avoiding one-sided deflection.

[0025] The hollow inner wall of the elastic clamping part 24 is machined into an upward-opening conical inner hole 25. The taper of this conical inner hole 25 perfectly matches the conical push rod 31 in the drive mechanism 3, forming a conical surface fit. When the conical push rod 31 moves upward and enters the conical inner hole 25, the axial pushing force generated due to the contact of the two conical surfaces is converted into a huge radial component force. These components force act on each elastic clamping petals 24, driving them to expand outward uniformly.

[0026] On the side wall of the quick-change clamping post 2, there is a through hole 26 that passes through the clamping post 2. This hole is the die hole through which the punch passes to complete the punching operation. The position, size and accuracy of the through hole 26 correspond to the punching requirements of the sample 5 being processed. The punch moves down through the die hole and impacts the sample 5, thereby completing the punching operation on the sample 5.

[0027] In this embodiment, the drive mechanism 3 is the power source of the entire mold system. Its main function is to drive the tapered push rod 31 inside the quick-change clamping column 2 to move axially, thereby achieving rapid clamping and release of the sample 5. The drive mechanism 3 is installed on one side of the mold base 1 and includes the tapered push rod 31 and a manual thread drive system. Among them, the tapered push rod 31 is the core working component of the drive mechanism 3. Its structure consists of two parts: a tapered head and a rod. The top of the tapered head is a sharp cone, and the taper matches the tapered inner hole 25 of the quick-change clamping column 2 to ensure uniform force during the clamping process. The rod of the tapered push rod 31 is cylindrical, passes through the through hole in the center of the mold base 1, and extends into the tapered inner hole 25 inside the quick-change clamping column 2, further applying pressure to the elastic clamping flap 24, pushing the elastic clamping flap 24 to expand outward and press against the inner side of the tubular sample 5.

[0028] In this embodiment, a manual thread drive system is used to achieve precise control of the tapered ejector rod 31. This system mainly comprises three parts: a threaded bracket 32, fixed below the mold base 1. This bracket is bracket-shaped, with internal threads machined on its upper inner side. The pitch, direction, and other parameters of the internal threads perfectly match the external threads of the tapered ejector rod 31. The threaded bracket 32 ​​is securely connected to the mold base 1 by bolts, providing stable support for the rotational movement of the tapered ejector rod 31.

[0029] The lower end of the tapered push rod 31 is machined with an external thread, which mates with the internal thread on the threaded support 32. When the tapered push rod 31 is rotated, the push rod 31 will move up and down axially due to the meshing of the threads.

[0030] A handwheel 34 is fixedly connected to the lowest end of the conical top rod 31. The operator drives the entire drive system by rotating the handwheel 34. The diameter of the handwheel 34 is large enough to obtain sufficient driving torque, so that the sample 5 can be clamped with a small rotational force.

[0031] The working method of the self-centering clamping and quick-change positioning die for a vertical punching machine described above is as follows: The first step, when processing tubular samples 5 of different specifications, is for the operator to perform a mold change operation. Based on the inner diameter of the sample 5 to be processed, the operator selects the appropriate size clamping post 2 from among several spare quick-change clamping posts 2. Then, the operator aligns the positioning base 21 of the selected quick-change clamping post 2 with the cylindrical mounting hole 11 on the mold base 1 and gently pushes it in until it is fully in place. During this process, the positioning pin 23 automatically slides into the positioning groove 12, ensuring the correct orientation of the clamping post 2.

[0032] The second step, after mold changing, requires the operator to restore the clamping system to its initial state, i.e., the clamping petals 24 are in a naturally retracted state. This is achieved by rotating the handwheel 34 in the reverse direction, causing the conical push rod 31 to fully retract to its lowest position. When the handwheel 34 is rotated in the reverse direction, the conical push rod 31 moves downward axially, gradually disengaging from the conical inner hole 25 of the clamping post 2. After losing the outward pushing force, each clamping petal 24 gradually returns to its original retracted state under the action of its own elastic restoring force. At this time, the outer surface of the clamping post 2 will shrink to its minimum, preparing for the insertion of the sample 5.

[0033] Third, the operator easily places the tubular sample 5 onto the quick-change clamping post 2. Since the outer diameter of the clamping post 2 is slightly smaller than the inner diameter of the tubular sample 5 (about 0.1-0.2 mm smaller), the sample 5 can be smoothly inserted without jamming or friction.

[0034] Fourthly, by rotating the handwheel 34 clockwise, the conical push rod 31 begins to move upward. As the push rod 31 rises, its conical head gradually enters the conical inner hole 25 of the quick-change clamping column 2. Due to the engagement of the two conical surfaces, as the conical push rod 31 rises further, the axial driving force is converted into a radial component by the conical surface engagement. This radial component acts evenly on each elastic clamping petals 24, driving them to expand outward uniformly.

[0035] As the clamping petals 24 expand outward, their outer surface gradually approaches and eventually adheres tightly to the inner wall of the tubular sample 5. Because the expansion process is uniform, the sample 5 is clamped evenly, automatically achieving centering. During this process, the operator can continue to rotate the handwheel 34 to gradually increase the clamping force until the sample 5 is firmly locked onto the clamping post 2. Finally, through strong friction, the sample 5 is completely fixed to the clamping post 2, without any radial movement or rotation.

[0036] Fifth, after the tubular sample 5 is fully clamped, the operator can start the punching mechanism 4 of the punching machine. The punch in the punching mechanism 4 descends rapidly under high-speed drive, impacting the tubular sample 5 at high speed through the machined through-hole 26 on the quick-change clamping post 2. Because the tubular sample 5 is rigidly clamped radially, any possible deflection or vibration is completely eliminated, making the punching process extremely stable. The punch accurately punches through the tube wall of the sample 5, completing a precisely positioned, dimensionally accurate, and regularly shaped hole in the tubular sample 5. Due to the absence of vibration or deflection interference, the roundness of the hole is excellent, the hole opening quality is good, and there are almost no burrs.

[0037] Finally, after stamping, the punch automatically retracts. At this point, the operator releases the clamp on sample 5 by rotating handwheel 34 in the reverse direction. As handwheel 34 rotates in the reverse direction, the conical push rod 31 begins to move downwards, gradually disengaging from the conical inner hole 25 of the quick-change clamping post 2. When push rod 31 is fully retracted, each elastic clamping flap 24 rapidly contracts under its own elastic drive, returning to its initial retracted state. At this point, the clamping force on sample 5 completely disappears, and sample 5 can be easily removed from clamping post 2. The operator can then easily remove the processed sample 5 from below, preparing for the processing of the next sample 5.

[0038] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any innovative improvements or substitutions based on this utility model should fall within the scope of the claims of this utility model. Furthermore, the parameters, materials, and processes mentioned in the above embodiments are not unique. Without departing from the technical essence of this utility model, those skilled in the art can make various alternative choices, and these alternative solutions should also be considered to fall within the scope of protection of this utility model.

Claims

1. A self-centering clamping and quick-change positioning die for a vertical punching machine, characterized in that, include: The mold base is set on the punching platform of the vertical punching machine. The upper surface of the mold base has a mounting hole for assembling quick-change clamping columns. The side wall of the mounting hole has a positioning groove along the axial direction. The center of the mold base has a through hole, which is coaxial with the cylindrical mounting hole and allows the conical ejector rod to pass through. The quick-change clamping column is detachably assembled into the mounting hole. The quick-change clamping column includes a positioning base and an elastic clamping part. The outer diameter of the positioning base is adapted to the diameter of the mounting hole. The side wall of the positioning base is provided with a positioning pin that is inserted into the elongated positioning groove. The outer wall of the elastic clamping part is provided with at least one slit along the axial direction. The inner wall of the elastic clamping part is a tapered inner hole that opens upward. The side wall of the elastic clamping part is provided with a through-hole for the punch to pass through. The drive mechanism includes a tapered push rod adapted to the taper of the tapered inner hole. The tapered push rod includes a tapered head and a rod portion. The rod portion passes through the through hole and engages with the drive assembly below the mold base. The tapered head extends into the tapered inner hole to drive the expansion of the elastic clamping part.

2. The self-centering clamping and quick-change positioning die for a vertical punching machine according to claim 1, characterized in that, The positioning pin is a protruding structure adapted to the positioning groove, and the length of the positioning pin is not greater than the distance from the side wall of the positioning base to the bottom of the elongated positioning groove.

3. The self-centering clamping and quick-change positioning die for a vertical punching machine according to claim 1, characterized in that, The outer diameter of the elastic clamping part is smaller than the standard inner diameter of the tubular sample to be processed by a first preset difference, the first preset difference being 0.1-0.2 mm.

4. The self-centering clamping and quick-change positioning die for a vertical punching machine according to claim 1, characterized in that, The axis of the processed through hole corresponds to the movement direction of the punch in the punching mechanism of the vertical punching machine, and the diameter of the processed through hole is adapted to the outer diameter of the punch to allow the punch to pass through.

5. The self-centering clamping and quick-change positioning die for a vertical punching machine according to claim 1, characterized in that, The drive assembly includes a transmission component for driving the tapered push rod to move axially, the transmission component cooperating with the rod portion of the tapered push rod, and the drive assembly also includes an operating component connected to the lower end of the rod portion.

6. The self-centering clamping and quick-change positioning die for a vertical punching machine according to claim 5, characterized in that, The operating component is a handwheel or a torque wrench, and the operating component is connected to the lower end of the rod via a detachable connection.

7. The self-centering clamping and quick-change positioning die for a vertical punching machine according to claim 1, characterized in that, The at least one slit is distributed circumferentially along the elastic clamping portion to allow the elastic clamping portion to expand uniformly when the conical push rod is driven.

8. The self-centering clamping and quick-change positioning die for a vertical punching machine according to claim 1, characterized in that, The outer diameter of the conical top rod is adapted to the through hole diameter of the mold base to allow the rod to move axially along the through hole.

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