A punch structure for punching a plastic product

Abstract

The utility model provides a punch the structure of cutting plastic product, including the tool holder, the one end of tool holder is integrally provided with the tool holder chuck, installs and sets up heating pipe element in the built -in groove of tool holder inside setting, the other end face of tool holder and punch head all is provided with the foolproof clamping groove and foolproof clamping block corresponding to each other, through the foolproof clamping groove and foolproof clamping block clamping embed together, and through the lock bolt fixed together, the utility model punch divides the tool holder and the head, through foolproof clamping groove clamping, bolt fixation, tool holder uses ordinary steel, and the head uses high hardness material to reduce the cost, and the head abrasion is easy to change, the built -in heating pipe of tool holder controls temperature, and the badness of punching and cutting is eliminated, and the tool holder sets up the chuck adaptation punching machine, and the structure is stable and is convenient to wire.

Description

Technical Field

[0001] This utility model belongs to the field of punching knife structure technology, and in particular relates to a punching knife structure for punching plastic products. Background Technology

[0002] In the field of plastic product processing, punches are the core components for punching and forming plastic parts (such as punching holes and trimming edges), and their structural rationality directly affects production efficiency, processing costs, and product quality. Currently, the industry generally uses a one-piece punch structure, which has the following prominent problems:

[0003] To meet the requirements for punching and wear resistance, the integrated punch must be made entirely of high-hardness, high-cost mold steel such as SKD11, resulting in high material costs. At the same time, as a wear part, the punch requires the entire punching mechanism to be disassembled for replacement after wear, which is not only time-consuming and labor-intensive (a single replacement usually takes 30-60 minutes), but also causes the production line to be shut down for a long time, seriously affecting production efficiency.

[0004] Traditional punching tools use a "hard punching" method to process plastic products. Because plastic materials have a certain degree of toughness, burrs, whitening of edges, and flash are easily generated during the punching process due to local stress concentration. This makes it difficult to meet the customer's requirements for product precision, and an additional manual trimming process is required, which further increases production costs and time.

[0005] Therefore, it is essential to invent a punch structure for punching plastic products. Utility Model Content

[0006] To solve the above-mentioned technical problems, this utility model provides a punching structure for punching plastic products, including a knife holder, a knife holder clip, an internal groove, a heating element, a foolproof clip, a foolproof block, a punching head, and a locking bolt. One end of the knife holder is integrally provided with a knife holder clip, and the heating element is installed in the internal groove provided inside the knife holder. The other end face of the knife holder and the punching head are provided with corresponding foolproof clips and foolproof blocks, which are engaged together and fixed together by the locking bolt.

[0007] Preferably, the blade holder clamp integrally provided on the blade holder is adapted to the punching head seat of the plastic punching machine, and the blade holder clamp is provided with an opening identical to the internal groove of the blade holder.

[0008] Preferably, the heating element built into the built-in groove of the blade holder is a resistance heating element, with the heating end of the heating element extending into it and close to the punch head, and the connection end of the heating element being connected to the temperature control circuit of the plastic punching machine.

[0009] Preferably, the anti-foolproof block on the punch cutter head is a rectangular protrusion structure with one corner chamfered. Circular anti-foolproof grooves are provided on both sides of the anti-foolproof block on the punch cutter head, and the anti-foolproof blocks and anti-foolproof grooves of the cutter holder and the punch cutter head are correspondingly matched.

[0010] Preferably, the punch head has a countersunk hole through its center, and the locking bolt passes through the countersunk hole of the punch head and is threadedly connected to the tool holder.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] This invention disassembles the punch into a tool holder and a punch head. Through the corresponding locking of anti-misalignment grooves and blocks (the rectangular protrusions on the punch head have a chamfered design, which, combined with the circular anti-misalignment groove on the tool holder, enables quick positioning and prevents incorrect installation), and then a locking bolt passes through the countersunk hole of the punch head and is threaded into the tool holder, forming a stable and easily disassembled split structure. On the one hand, the tool holder does not need to bear the punching force and can be made of ordinary steel; only the punch head uses a high-hardness material, significantly reducing overall material costs. On the other hand, when the punch head wears out, there is no need to disassemble the entire punching mechanism; it can be replaced simply by loosening the locking bolt. The replacement time is shortened to 5-10 minutes, significantly reducing production line downtime and improving production efficiency.

[0013] This utility model features an internal groove in the blade holder, with a built-in resistance heating element whose heating end is deep and close to the punching blade head, enabling efficient heat transfer to the cutting edge. The heating element is connected to the temperature control circuit of the plastic punching machine, allowing precise control of the blade head temperature (adapting to the softening temperature range of different plastics). This ensures that the plastic is locally molten and softened during punching, avoiding the "tearing" process of traditional hard punching, and completely eliminating defects such as burrs, whitening, and flash. This significantly reduces the product defect rate, eliminates the need for subsequent manual trimming, and further saves costs.

[0014] This utility model features an integrated blade holder clamp at one end of the blade holder. This clamp precisely matches the punching head of the plastic punching machine, ensuring accurate positioning of the punch during overall installation and avoiding punching accuracy errors caused by installation deviations. Simultaneously, the clamp has an opening identical to the built-in groove, facilitating the installation and wiring of the heating element and ensuring compatibility between the heating element and the punching mechanism. This reduces equipment debugging difficulty and enhances the overall stability and reliability of the structure. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] Figure 2 This is an exploded structural diagram of the present invention.

[0017] Figure 3 This is a schematic diagram of the structure of the punch cutter head of this utility model.

[0018] In the picture:

[0019] 1. Tool holder, 2. Tool holder collet, 3. Built-in groove, 4. Heating element, 5. Anti-foolproof slot, 6. Anti-foolproof block, 7. Punch cutter head, 8. Locking bolt. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 should fall within the protection scope of the present invention.

[0021] In the description of the embodiments, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for 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 the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the utility model, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present utility model based on the specific circumstances.

[0022] As attached Figure 1 To be continued Figure 3 As shown:

[0023] This utility model provides a punching structure for punching plastic products, including a knife holder 1, a knife holder clip 2, an internal groove 3, a heating element 4, a foolproof groove 5, a foolproof block 6, a punching head 7, and a locking bolt 8. The knife holder 1 is integrally provided with the knife holder clip 2 at one end, and the heating element 4 is installed in the internal groove 3 provided inside the knife holder 1. The other end face of the knife holder 1 and the punching head 7 are provided with corresponding foolproof grooves 5 and foolproof blocks 6, which are engaged together and fixed together by the locking bolt 8.

[0024] Furthermore, the tool holder 1 is made of Q235 ordinary carbon structural steel (meeting the support and fixing requirements while reducing costs), and is integrally machined by CNC lathe and milling machine. One end is integrally equipped with a tool holder chuck 2—the tool holder 1 and tool holder chuck 2 are machined from the same piece of steel without any splicing gaps, ensuring structural strength. The outer dimensions of the tool holder chuck 2 are precisely matched to the mounting holes of the punching head seat of the plastic punching machine. During installation, the tool holder chuck 2 can be directly inserted into the punching head seat and locked to the punching head seat bolts through the M6 ​​threaded holes (located on the side wall of the tool holder chuck 2), achieving a stable connection between the punch and the punching machine and preventing radial wobbling during the punching process. Meanwhile, a cylindrical built-in groove 3 (for accommodating the heating element 4) is provided axially inside the tool holder 1. A circular opening of the same diameter is provided on the tool holder chuck 2 at the position corresponding to the built-in groove 3. This opening is coaxial with the built-in groove 3, which facilitates the wires of the heating element 4 to pass through the opening and also facilitates the installation of the heating element 4 into the built-in groove 3 from the opening end. At the same time, it does not hinder the tight fit between the heating element 4 and the tool holder 1 (ensuring heat conduction efficiency).

[0025] Furthermore, the heating element 4 installed in the built-in groove 3 of the tool holder 1 is a nickel-chromium alloy resistance heating element (the heating element is a Φ0.8mm nickel-chromium alloy wire, the outer shell is a Φ7.8-11.8mm 304 stainless steel tube, and the tube is filled with magnesium oxide insulating powder). Its length matches the depth of the built-in groove 3 (ensuring complete embedment in the built-in groove 3 without protrusion). The heating end of the heating element 4 (the end closest to the punch head 7) extends into the end of the built-in groove 3, only 5-8mm away from the contact surface between the tool holder 1 and the punch head 7. The gap between the outer shell of the heating element 4 and the inner wall of the built-in groove 3 is controlled at 0.1-0.2mm. It is fixed in the built-in groove 3 by a high-temperature resistant ceramic sleeve (fitted in the middle of the heating element 4) to prevent displacement of the heating element 4 due to punching vibration. Two high-temperature silicone wires (0.75mm in diameter) resistant to 200℃ are led out from the connecting end (wire end) of the heating element 4. 2The wire passes through the opening of the cutter holder 2 and is used to connect to the temperature control circuit of the plastic punching machine. The punch head 7 is made of SKD11 cold work die steel (quenched hardness HRC58-62, meeting the requirements for punching wear resistance). Its contact surface with the cutter holder 1 is machined to a roughness of Ra0.8μm by a surface grinder to ensure that the heat generated by the heating element 4 can be quickly conducted to the punch head 7 through the cutter holder 1, so that the cutting edge temperature of the punch head 7 rises evenly to the plastic softening temperature range (such as 120-150℃ for PP plastic and 150-180℃ for ABS plastic).

[0026] Furthermore, the end of the punch cutter head 7 facing the tool holder 1 is integrally machined with an anti-misalignment block 6. The anti-misalignment block 6 is a rectangular protrusion structure with a chamfered corner (which not only prevents damage during installation but also serves as an anti-misalignment mechanism—the anti-misalignment block 6 can only be inserted into the groove of the tool holder 1 when the chamfer corresponds to a specific position on the tool holder 1, preventing the punch cutter head 7 from being installed backwards). On both sides of the anti-misalignment block 6 of the punch cutter head 7, two circular anti-misalignment slots 5 are symmetrically provided; correspondingly, on the end face of the tool holder 1 facing the punch cutter head 7, a rectangular groove adapted to the anti-misalignment block 6 is machined (to accommodate the anti-misalignment block 6), and on both sides of the rectangular groove, circular bosses adapted to the anti-misalignment slots 5 are machined. During installation, the anti-foolproof locking block 6 of the punch cutter head 7 is inserted into the rectangular groove of the cutter holder 1, and at the same time, the circular boss of the cutter holder 1 is embedded into the anti-foolproof locking groove 5 of the punch cutter head 7, forming a two-way positioning structure to ensure that the coaxiality error between the cutter holder 1 and the punch cutter head 7 is ≤0.02mm, thus avoiding hole position deviation or uneven blade wear caused by cutter head offset during punching.

[0027] Furthermore, the punch head 7 has a stepped countersunk hole extending axially through its center. The upper section of the countersunk hole is a cylindrical hole (for accommodating the head of the locking bolt 8), and the lower section is a through hole (for the threaded part of the locking bolt 8 to pass through). The transition between the upper and lower sections of the countersunk hole wall is machined with a radius of 0.5mm to prevent stress concentration from causing the punch head to crack. The locking bolt 8 is made of 45# steel (with galvanized anti-rust treatment) and is an M5×15mm internal hexagonal head bolt. Correspondingly, the punch holder 1 has an M5 internal threaded hole axially extending at its center that matches the locking bolt 8. During installation, the bolt 8 is inserted through the lower section of the countersunk hole of the punch head 7 and screwed into the internal threaded hole of the tool holder 1. The tightening torque is controlled at 8-10 N·m (ensuring a tight fit between the tool holder 1 and the punch head 7 while avoiding over-tightening that could deform the tool holder 1 or the punch head 7). The bolt head is fully embedded in the upper section of the countersunk hole, with its top surface flush with the end face of the punch head 7 away from the tool holder 1, and not protruding from the surface of the head to prevent scratching the plastic product or interfering with the punching path during punching. At the same time, a spring washer (made of 65Mn steel) is placed between the head of the locking bolt 8 and the bottom surface of the upper section of the countersunk hole. The elastic deformation of the spring washer is used to counteract punching vibrations and prevent the locking bolt 8 from loosening.

[0028] Furthermore, the heating element 4 is connected to the quick-connect electrical connector on the punching machine body via a high-temperature resistant wire passing through the interface of the blade holder 2. This connector is connected to the output of a temperature controller via a shielded cable. Simultaneously, a thermocouple or platinum resistance temperature sensor is installed in the built-in slot 3 of the blade holder 1 or close to the outer wall of the blade holder 1 to monitor the blade temperature in real time. The signal line of this sensor is also led back to the signal input of the temperature controller. The temperature controller acts as the system's brain, receiving start / stop commands and temperature setpoints from the punching machine's main control PLC. The operator can set the desired punching temperature on the human-machine interface (HMI). The temperature controller compares the setpoint with the sensor feedback value and uses a PID algorithm to precisely control the power output to the heating element 4, thereby achieving automatic and stable control of the punching blade's operating temperature and ensuring high-quality punching results.

[0029] The working principle is as follows: First, the punch is installed and fixed to the plastic punching machine: the punch holder 1 is fitted and installed with the punching head seat of the plastic punching machine through the punch holder clasp 2, which is integrally set at one end. The punch holder clasp 2 is inserted into the mounting hole of the punching head seat and locked with bolts, so that the punch holder 1 and the punching machine form a stable connection, providing stable support for subsequent punching operations, avoiding radial shaking of the punch holder 1 during the punching process, and ensuring punching accuracy.

[0030] Next, the assembly and positioning of the tool holder 1 and the punch head 7 are completed: the other end face of the tool holder 1 and the punch head 7 are engaged through corresponding anti-misalignment grooves 5 and anti-misalignment blocks 6. The anti-misalignment block 6 is inserted into the rectangular groove of the tool holder 1, and at the same time, the circular boss of the tool holder 1 is embedded in the anti-misalignment groove 5 of the punch head 7. The anti-misalignment structure ensures that the punch head 7 will not be installed backwards and ensures the coaxiality of the tool holder 1 and the punch head 7. Then, the locking bolt 8 passes through the stepped countersunk hole in the center of the punch head 7, is screwed into the internal threaded hole in the center of the tool holder 1 and locked, so that the tool holder 1 and the punch head 7 fit tightly together, which provides sufficient connection strength for punching operations and ensures smooth heat conduction in the future.

[0031] Next, the heating system is started and temperature control is implemented: When the punching operation is about to begin, the main control PLC of the punching machine sends a start command and a preset temperature setpoint to the temperature controller. After receiving the command, the temperature controller controls the heating element 4 to be energized and heated. The heating element 4 is installed in the built-in groove 3 inside the cutter holder 1. The heat generated by it is conducted to the cutter holder 1 through close contact with it, and then from the cutter holder 1 to the punching head 7 that is in close contact with it. At the same time, the thermocouple / platinum resistance temperature sensor installed in the built-in groove 3 of the cutter holder 1 or close to the outer wall of the cutter holder 1 detects the temperature of the cutter holder 1 and the punching head 7 in real time and feeds the temperature signal back to the temperature controller. The temperature controller compares the preset temperature value with the actual temperature value fed back by the sensor through a PID algorithm and automatically adjusts the power output to the heating element 4 so that the temperature of the punching head 7 is stably maintained in the softening temperature range suitable for plastic products, preparing for high-quality punching.

[0032] Then, the punching operation of the plastic product is performed: when the temperature controller detects that the temperature of the punch head 7 has reached the preset value, it sends a "temperature ready" signal to the main control PLC of the punching machine; after receiving the signal, the main control PLC controls the punching mechanism of the punching machine to move, driving the knife holder 1 and the punch head 7 to move downward, and the punch head 7 contacts the plastic product and completes the punching; since the punch head 7 is in the plastic softening temperature range, the local area of ​​the plastic product in contact with the knife head is in a molten and softened state during the punching process, avoiding the problems of burrs, whitening and flash caused by traditional hard punching. At the same time, the knife holder 1 remains stable under the fixing action of the knife holder chuck 2, ensuring that the punching action is smooth and accurate.

[0033] Finally, the punch cutter head 7 is replaced and maintained: When the punch cutter head 7 is worn due to long-term punching and needs to be replaced, first remove the locking bolt 8 and remove the worn punch cutter head 7 from the tool holder 1; then, the new punch cutter head 7 is inserted and positioned into the tool holder 1 through the anti-foolproof slot 5 and the anti-foolproof block 6, and then the locking bolt 8 is passed through the countersunk hole of the punch cutter head 7 and screwed into the internal thread hole of the tool holder 1 to lock it. The replacement of the punch cutter head 7 can be completed without disassembling the tool holder 1 and the tool holder chuck 2, realizing the quick replacement of the punch cutter head 7, reducing equipment downtime and improving production efficiency.

[0034] Any technical solution that achieves the above-mentioned technical effects by utilizing the technical solution described in this utility model, or by designing a similar technical solution inspired by the technical solution described in this utility model, falls within the protection scope of this utility model.

Claims

1. A punch structure for punching plastic products, characterized in that, The tool holder includes a tool holder (1), a tool holder clip (2), an internal groove (3), a heating element (4), a foolproof clip (5), a foolproof clip (6), a punch head (7), and a locking bolt (8). One end of the tool holder (1) is integrally provided with a tool holder clip (2), and the heating element (4) is installed in the internal groove (3) provided inside the tool holder (1). The other end face of the tool holder (1) and the punch head (7) are provided with corresponding foolproof clips (5) and foolproof clips (6), which are engaged together by the foolproof clips (5) and foolproof clips (6) and fixed together by the locking bolt (8).

2. The punch structure for punching plastic products as described in claim 1, characterized in that: The blade holder (1) is integrally provided with a blade holder chuck (2) that is compatible with the punching head seat of the plastic punching machine. The blade holder chuck (2) has an opening that is the same as the built-in groove (3) opened on the blade holder (1).

3. The punch structure for punching plastic products as described in claim 2, characterized in that: The heating element (4) built into the built-in groove (3) of the blade holder (1) is a resistance heating element. The heating end of the heating element (4) extends into it and is close to the punch head (7). The connection end of the heating element (4) is connected to the temperature control circuit of the plastic punching machine.

4. The punch structure for punching plastic products as described in claim 3, characterized in that: The anti-foolproof block (6) provided on the punch cutter head (7) is a rectangular protrusion structure with one corner being chamfered. Circular anti-foolproof grooves (5) are provided on both sides of the anti-foolproof block (6) of the punch cutter head (7). The anti-foolproof block (6) of the cutter holder (1) and the anti-foolproof grooves (5) of the punch cutter head (7) are correspondingly matched.

5. The punch structure for punching plastic products as described in claim 4, characterized in that: The punch head (7) has a countersunk hole through its center, and the locking bolt (8) passes through the countersunk hole of the punch head (7) and is threadedly connected to the tool holder (1).

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