Low-tailing quick-change die head for rubber extrusion

Abstract

The utility model discloses a low-tailing quick-change die head for rubber extrusion, which comprises a die head base, at least two radially extending sliding chutes, a lower die head, an upper die head, a lower die head, a lower die head, an upper die head and a lower die head, wherein the side wall of the die head base is provided with at least two radially extending sliding chutes; the number of the locking blocks corresponds to that of the sliding grooves, each locking block is arranged in the corresponding sliding groove in a sliding mode, and a first conical surface is arranged on the side, facing the center of the die head, of each locking block; the first elastic element is arranged in the sliding groove, one end of the first elastic element is connected with the locking block, and the other end of the first elastic element is connected with the inner wall of the sliding groove. The cam ring is rotatably arranged outside the die head base in a sleeving mode, a cam profile is arranged on the inner wall of the cam ring, and the cam profile makes contact with the outer side of the locking block and is configured to be capable of driving the locking block to overcome the pre-tightening force of the first elastic element to move inwards in the radial direction during rotation; and the mold core is detachably mounted in the mold head base, a runner is formed in the mold core, and a second conical surface which is in pressing fit with the first conical surface of the locking block is arranged on the mold core.

Description

Technical Field

[0001] This utility model relates to the technical field, and in particular to a low-tail quick-change die head for rubber extrusion. Background Technology

[0002] In the rubber extrusion production process, the die head is the core component that determines the cross-sectional shape and dimensional accuracy of the product. As a key component of the die head, the die core needs to be frequently replaced according to different product specifications. The existing rubber extrusion die core fixing methods mostly use bolt locking or pin positioning. When replacing, it is necessary to disassemble it one by one with tools such as wrenches and screwdrivers, which is cumbersome and time-consuming, seriously affecting the continuity of production. At the same time, the internal flow channel design of the die core is mostly a straight-through or single conical structure. When the rubber material flows in the flow channel, it is easy to cause stagnation and adhesion. This results in a large amount of residual material when changing the die, which not only wastes raw materials, but also requires additional manpower to clean the flow channel, further reducing production efficiency.

[0003] In addition, some die heads have insufficient locking stability, which can easily lead to die core displacement during extrusion and affect product dimensional accuracy; uneven heat dissipation in the flow channel may cause premature vulcanization of rubber materials, reducing product quality; and the problem of material adhering to the flow channel will increase cleaning difficulty and maintenance costs. These derivative problems together restrict the improvement of the overall efficiency of rubber extrusion production. Utility Model Content

[0004] To address the technical problems mentioned above, this utility model proposes a low-tail quick-change die head for rubber extrusion.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A low-tail quick-change die head for rubber extrusion, comprising:

[0007] A mold head base, wherein at least two radially extending grooves are provided on the side wall of the mold head base;

[0008] The locking blocks are numbered in relation to the number of slide grooves. Each locking block is slidably disposed in the corresponding slide groove, and the locking block has a first conical surface on the side facing the center of the mold head.

[0009] A first elastic element is disposed in the slide groove, with one end connected to the locking block and the other end connected to the inner wall of the slide groove, for providing radially outward preload to the locking block;

[0010] A cam ring is rotatably fitted onto the outside of the die head base. The inner wall of the cam ring is provided with a cam profile. The cam profile contacts the outer side of the locking block and is configured to drive the locking block to move radially inward against the preload of the first elastic element when rotating.

[0011] The mold core is detachably installed in the mold head base. The mold core has a flow channel and a second conical surface that presses against the first conical surface of the locking block.

[0012] Furthermore, a roller is installed at the end of the locking block opposite to the first conical surface, and the roller rolls into contact with the cam profile of the cam ring.

[0013] Furthermore, the mold core is provided with a limiting part, and a second elastic element is connected to the surface of the mold head base that is in contact with the limiting part. The second elastic element is used to provide axial restoring force for the mold core.

[0014] Furthermore, the flow channel within the mold core includes a feeding section, a compression section, and a relaxation section connected in sequence; the feeding section has a truncated conical structure with an inlet diameter larger than its outlet diameter; the compression section has a smoothly tapering cross-sectional area in the direction away from the feeding section; and the relaxation section has a truncated conical structure with an inlet diameter smaller than its outlet diameter.

[0015] Furthermore, the inner wall of the flow channel is coated with an adhesive coating.

[0016] Furthermore, the mold core is provided with a cooling channel, which is configured to be connected to an external cooling system.

[0017] Furthermore, the adhesive coating is a polytetrafluoroethylene coating.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] Compared with existing technologies, this utility model, through core structural innovation and optimized additional features, allows for quick locking and unlocking of the die core without tools, significantly shortening die change time and improving production continuity. The roller and axial reset design further reduces operational intensity and simplifies the operation process. The three-section flow channel design, PTFE low-adhesion coating, and cooling channels work together to significantly reduce tail material loss, improve raw material utilization, and lower production costs. Multiple locking blocks are evenly distributed circumferentially, and the conical surface pressing method ensures balanced force distribution. Combined with the pre-tightening force of the elastic element, this ensures the die core fixing accuracy, guarantees the dimensional stability of the extruded product, and eliminates installation gaps to prevent material leakage. The roller design, low-adhesion coating, and cooling channels work together to extend the overall service life of the equipment and reduce maintenance costs. By replacing the die core with different flow channel specifications, it can adapt to the extrusion needs of various rubber products. Furthermore, the various additional feature modules can be flexibly combined according to production needs to adapt to different working conditions. This effectively solves the technical pain points of traditional rubber extrusion dies, such as slow die change, excessive tail material, and poor stability, and has significant economic value and application prospects. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the low-tail quick-change die head for rubber extrusion proposed in this utility model.

[0021] Figure 2 This is a schematic diagram of the locking block in the low-tail quick-change die head for rubber extrusion proposed in this utility model.

[0022] Figure 3 This is a schematic diagram of the cam ring structure in the low-tail quick-change die head for rubber extrusion proposed in this utility model;

[0023] Figure 4 This is a schematic diagram of the die core in the low-tail quick-change die head for rubber extrusion proposed in this utility model;

[0024] Figure 5 This utility model Figure 1 A magnified structural diagram of point A in the middle.

[0025] In the figure: 1-Die head base, 11-Slide groove, 2-Die core, 21-Flow channel, 211-Feed section, 212-Compression section, 213-Relaxation section, 22-Second cone surface, 23-Limiting part, 24-Cooling channel, 3-Cam ring, 31-Cam profile, 4-Locking block, 41-Roller, 5-First elastic element, 6-Second elastic element. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] like Figures 1-5 As shown, this embodiment provides a low-tail quick-change die head for rubber extrusion, comprising:

[0028] The mold base 1 has at least two radially extending grooves 11 on its side wall;

[0029] Locking blocks 4, the number of which corresponds to the number of slide grooves 11, each locking block 4 is slidably disposed in the corresponding slide groove 11, and the locking block 4 has a first conical surface on the side facing the center of the mold head;

[0030] The first elastic element 5 is disposed in the slide groove 11, with one end connected to the locking block 4 and the other end connected to the inner wall of the slide groove 11, for providing radially outward preload force to the locking block 4.

[0031] Cam ring 3, which is rotatably sleeved on the outside of the die head base 1, has a cam profile 31 on its inner wall. The cam profile 31 contacts the outer side of the locking block 4 and is configured to drive the locking block 4 to move radially inward against the preload of the first elastic element 5 when rotating.

[0032] The mold core 2 is detachably installed in the mold head base 1. The mold core 2 has a flow channel 21 and a second conical surface 22 that is pressed and engaged with the first conical surface of the locking block 4.

[0033] Overall, the mold base 1, which serves as the mounting reference and load-bearing body of the mold head, is integrally formed from high-strength alloy steel. Its sidewalls are uniformly provided with at least two radially extending grooves 11 (preferably 3-4 to ensure balanced locking force). The inner wall of the groove 11 is provided with guide grooves and elastic element mounting holes to provide sliding guidance for the locking block 4 and fixing points for the first elastic element 5.

[0034] The number of locking blocks 4 corresponds one-to-one with the slide grooves 11. They are made of wear-resistant alloy material, and their shape is adapted to the slide grooves 11 and can slide radially along the slide grooves 11. The locking block 4 has a first conical surface (preferably 30°-45°) machined on the side facing the center of the mold head, which is used to form a close and tight fit with the mold core 2. The outer end face of the locking block 4 is the force-bearing surface, which contacts the cam profile 31 of the cam ring 3.

[0035] The first elastic element 5 is preferably a cylindrical helical spring, which is disposed inside the slide groove 11. One end of the spring is embedded in the spring groove of the locking block 4, and the other end is fixed in the mounting hole on the inner wall of the slide groove 11. In its natural state, the first elastic element 5 is in a pre-compressed state, providing a continuous radial outward restoring force to the locking block 4, so that the locking block 4 is kept in the unlocked initial position.

[0036] The cam ring 3 adopts a ring structure and is rotatably fitted onto the outside of the die head base 1. Its inner wall is machined with a cam profile 31 corresponding to the outer side of the locking block 4 (the lift of the cam profile 31 is designed to be 5-8mm to match the radial stroke of the locking block 4). The outer side of the cam ring 3 is provided with anti-slip texture or wrench groove, which makes it convenient for operators to rotate manually or with the help of simple tools. A positioning pin or limiting boss is provided between the cam ring 3 and the die head base 1 to limit its rotation angle range (usually 0°-60°) to avoid excessive rotation that could damage the components.

[0037] The mold core 2 is made of heat-resistant and wear-resistant alloy steel and is detachably installed in the central mounting hole of the mold head base 1. A through flow channel 21 is opened at its axis (for the flow and molding of rubber material). The outer wall of the mold core 2 is machined with a second conical surface 22 corresponding to the position of the locking block 4. The cone angle of the second conical surface 22 is consistent with that of the first conical surface (fitting gap ≤ 0.02mm) to ensure that surface contact and pressing are formed when locking.

[0038] After inserting the mold core 2 into the center mounting hole of the mold head base 1, rotate the cam ring 3 clockwise. The cam profile 31 on the inner wall of the cam ring 3 gradually presses against the outer force-bearing surface of the locking block 4, forcing the locking block 4 to overcome the preload of the first elastic element 5 and slide radially inward along the slide groove 11. When the cam ring 3 rotates to the limit position, the first conical surface of the locking block 4 and the second conical surface 22 of the mold core 2 are completely pressed together. The axial component force generated by the conical surface engagement firmly fixes the mold core 2, completing the locking operation. When the mold core 2 needs to be replaced, rotate the cam ring 3 counterclockwise. The pressing force of the cam profile 31 on the locking block 4 is gradually released. Under the action of the reset force of the first elastic element 5, the locking block 4 slides radially outward along the slide groove 11. The first conical surface and the second conical surface 22 separate, the fixing restriction of the mold core 2 is released, and the mold core 2 can be directly removed for replacement.

[0039] This structure allows for locking and unlocking of the mold core 2 without tools, making mold changing operations efficient and convenient, significantly improving production efficiency. The conical surface fitting locking method ensures balanced force distribution and high fixing accuracy of the mold core 2, guaranteeing the dimensional stability of extruded products. Furthermore, the structure is simple, with fewer parts, resulting in low manufacturing costs and convenient maintenance, requiring only periodic checks on spring elasticity and conical surface wear.

[0040] like Figure 2 As shown, in this embodiment, a roller 41 is installed at the end of the locking block 4 opposite to the first conical surface, and the roller 41 rolls with the cam profile 31 of the cam ring 3.

[0041] Specifically, the additional feature of "roller 41" is added: the end of the locking block 4 opposite to the first conical surface (outer end face) is equipped with roller 41 by a pin, and roller 41 forms a rolling fit with the cam profile 31 of the cam ring 3.

[0042] Additional structural details: Roller 41 is made of bearing steel (outer diameter 8mm, inner diameter 3mm) and is hinged to locking block 4 by stainless steel pin. The rotational resistance of roller 41 is ≤0.3N. Cam surface 31 is machined into a rounded transition structure with a surface roughness Ra≤0.8μm and no sharp edges on the contact surface with roller 41.

[0043] By setting the roller 41, the sliding friction between the locking block 4 and the cam surface 31 is converted into rolling friction, which significantly reduces the coefficient of friction. When rotating the cam ring 3, the operating force is greatly reduced, reducing the intensity of manual labor. At the same time, it greatly reduces the wear of parts, extends the service life of the locking block 4 and the cam ring 3, reduces equipment maintenance costs, and avoids the jamming phenomenon caused by sliding friction, making the locking / unlocking process of the mold core 2 smoother and further improving the mold changing efficiency.

[0044] like Figure 1 and Figure 5 As shown, in this embodiment, the mold core 2 is provided with a limiting part 23, and a second elastic element 6 is connected to the surface of the mold head base 1 that is in contact with the limiting part 23. The second elastic element 6 is used to provide axial restoring force for the mold core 2.

[0045] Specifically, the additional feature of "limiting part 23 + second elastic element 6" is added: the tail of the mold core 2 is provided with an annular limiting part 23, and the end face of the mold head base 1 that fits with the limiting part 23 is provided with an annular mounting groove, in which a second elastic element 6 (preferably a disc spring) is installed to provide axial restoring force for the mold core 2.

[0046] When unlocking, the restoring force of the second elastic element 6 can automatically push the mold core 2 out of the mold head base 1 without manual prying, making it easier to remove the mold core 2 and further shortening the mold change time. In the locked state, the pre-tightening force of the second elastic element 6 makes the limiting part 23 of the mold core 2 fit tightly with the end face of the mold head base 1, eliminating gaps and preventing rubber material from leaking from the gaps during extrusion, reducing tail material residue. At the same time, the second elastic element 6 can buffer the axial impact force on the mold core 2 during extrusion, playing a shock absorption role, protecting the mold core 2 and the mold head base 1, and extending the overall service life.

[0047] like Figure 1 and Figure 4 As shown, in this embodiment, the flow channel 21 within the mold core 2 includes a feeding section 211, a compression section 212, and a relaxation section 213 connected in sequence; the feeding section 211 has a truncated conical structure, and its inlet diameter is larger than its outlet diameter; the compression section 212 has a smoothly tapering cross-sectional area in the direction away from the feeding section 211; the relaxation section 213 has a truncated conical structure, and its inlet diameter is smaller than its outlet diameter.

[0048] Specifically, the additional feature of "three-section flow channel 21" is added: the flow channel 21 inside the mold core 2 consists of a feed section 211, a compression section 212 and a relaxation section 213 connected in sequence, and the structural design of each section is as follows:

[0049] The feeding section 211 has a truncated conical structure with an inlet diameter larger than the outlet diameter, which guides the rubber material smoothly into the flow channel 21 and reduces the inlet flow resistance. The cross-sectional area of ​​the compression section 212 gradually decreases from the outlet of the feeding section 211 along a parabolic trajectory to the inlet of the relaxation section 213, which fully compacts the rubber material and eliminates internal air bubbles. The relaxation section 213 has a truncated conical structure with an inlet diameter smaller than the outlet diameter, which reduces the material outlet pressure and reduces residual material.

[0050] The three-section flow channel 21 conforms to the flow characteristics of rubber materials, allowing the material to flow smoothly within the flow channel 21 without obvious stagnation areas, greatly reducing tail material loss and improving raw material utilization. The smooth tapering design of the compression section 212 fully plasticizes the rubber material, resulting in uniform product density, improved surface quality, and enhanced product molding quality. The flared structure of the relaxation section 213 reduces elastic recoil at the material exit, further reducing tail material residue and simplifying the cleaning operation of the flow channel 21.

[0051] like Figure 1 and Figure 4 As shown, in this embodiment, the inner wall of the flow channel 21 is coated with an adhesive coating.

[0052] The adhesive coating is a polytetrafluoroethylene coating.

[0053] Specifically, an additional feature of "adhesive coating" is added: the inner wall of flow channel 21 is coated with a polytetrafluoroethylene (PTFE) low-adhesion coating, which is prepared by electrostatic spraying process.

[0054] The polytetrafluoroethylene coating has excellent non-stick properties, which greatly reduces the adhesion between the rubber material and the inner wall of the flow channel 21, further reducing the amount of tail material residue. The flow channel 21 does not require frequent cleaning, significantly reducing maintenance workload. The low coefficient of friction reduces material flow resistance, increases extrusion speed, and further improves production efficiency. The coating also has good corrosion resistance and wear resistance, which can resist the erosion of additives in the rubber material and extend the service life of the mold core 2.

[0055] like Figure 1 and Figure 4 As shown, in this embodiment, the mold core 2 is provided with a cooling channel 24, which is configured to be connected to an external cooling system.

[0056] Specifically, an additional feature called "cooling channel 24" is added: a ring-shaped cooling channel 24 is provided inside the mold core 2 along the circumference. The inlet and outlet of the cooling channel 24 are respectively opened on the tail end face of the mold core 2 and connected to the external cooling system (cooling water circulation device) through a quick connector.

[0057] Cooling channel 24 removes heat from mold core 2 through cooling water circulation, making the inner wall temperature of flow channel 21 uniform, avoiding premature vulcanization of rubber material due to local overheating, ensuring product molding quality and dimensional accuracy. Appropriately reducing the inner wall temperature of flow channel 21 can further reduce the adhesion of rubber material and reduce the amount of residual material. The stable temperature environment reduces the deformation of mold core 2 caused by thermal expansion and contraction, extends the service life of mold core 2, and avoids the impact of high temperature on the first elastic element 5, ensuring the stability of the locking mechanism.

[0058] Of course, those skilled in the art will recognize that this invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0059] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0060] The technologies, shapes, and structures not described in detail in this utility model are all known technologies.

Claims

1. A low-tail quick-change die head for rubber extrusion, characterized in that, include: The mold base (1) has at least two radially extending grooves (11) on its side wall. Locking blocks (4), the number of locking blocks (4) corresponds to the number of slide grooves (11), each locking block (4) is slidably disposed in the corresponding slide groove (11), and the locking block (4) has a first conical surface on the side facing the center of the mold head; The first elastic element (5) is disposed in the slide groove (11), with one end connected to the locking block (4) and the other end connected to the inner wall of the slide groove (11), for providing radially outward preload force to the locking block (4); Cam ring (3), the cam ring (3) is rotatably sleeved on the outside of the mold base (1), the inner wall of the cam ring (3) is provided with cam profile (31), the cam profile (31) contacts the outer side of the locking block (4), and is configured to drive the locking block (4) to move radially inward against the preload of the first elastic element (5) when rotating; The mold core (2) is detachably installed in the mold head base (1). The mold core (2) has a flow channel (21) and a second conical surface (22) that presses against the first conical surface of the locking block (4).

2. The low-tail quick-change die head for rubber extrusion according to claim 1, characterized in that, The locking block (4) is equipped with a roller (41) at one end opposite to the first conical surface, and the roller (41) rolls in contact with the cam profile (31) of the cam ring (3).

3. The low-tail quick-change die head for rubber extrusion according to claim 1, characterized in that, The mold core (2) is provided with a limiting part (23), and a second elastic element (6) is connected to the surface of the mold base (1) that is in contact with the limiting part (23). The second elastic element (6) is used to provide axial restoring force for the mold core (2).

4. The low-tail quick-change die head for rubber extrusion according to claim 1, characterized in that, The flow channel (21) inside the mold core (2) includes a feeding section (211), a compression section (212), and a relaxation section (213) connected in sequence; the feeding section (211) is a truncated cone structure, and its inlet diameter is larger than its outlet diameter; the compression section (212) has a smoothly tapered cross-sectional area in the direction away from the feeding section (211); the relaxation section (213) is a truncated cone structure, and its inlet diameter is smaller than its outlet diameter.

5. The low-tail quick-change die head for rubber extrusion according to claim 1, characterized in that, The inner wall of the flow channel (21) is coated with an adhesive coating.

6. The low-tail quick-change die head for rubber extrusion according to claim 1, characterized in that, The mold core (2) is provided with a cooling channel (24), which is configured to be connected to an external cooling system.

7. The low-tail quick-change die head for rubber extrusion according to claim 5, characterized in that, The adhesive coating is a polytetrafluoroethylene coating.

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