Cutter structure of a pelletizer

Abstract

This invention proposes a cutting tool structure for a material cutter, in which a plurality of blade sets are arranged in a ring on a hollow blade body shell. The blade pieces are protruded into corresponding blade receiving grooves using wedge-shaped members, and the wedge-shaped members are inserted through and screwed into the inner side of the blade body shell. This prevents the fixing members from being impacted by plastic particles generated during the cutting process, thereby reducing the wear of the fixing members. The wedge-shaped members also improve the convenience of blade replacement and maintenance.

Description

Cutting machine blade structure Cutter Structure of a Pelletizer Technical Field

[0001] This invention relates to the blade structure of a cutting machine, and more particularly to the blade structure of a cutting machine capable of cutting plastic strips into granules. Prior Technology

[0002] Plastic cutting machines are widely used in various industries, especially in the plastic extrusion granulation industry. Plastic cutting machines typically cut plastic extruded strips containing glass fiber, metal, minerals or combustion aids into granules for subsequent plastic molding. Currently, most cutting machine blade structures widely used on the market are equipped with ring blades, which cut the plastic extruded strips by means of the circumferential cutting motion of the ring blades.

[0003] In existing plastic cutting machines, the rotating blades are mainly fixed and positioned using detachable methods. One common technique is the screw-locking design, which directly locks the rotating blade to the blade body with side screws or top screws. While the structure appears simple, the nuts are exposed inside the cutting chamber. After cutting, plastic particles bounce at high speed and impact the inner wall, causing continuous wear. Furthermore, the nuts are easily worn flat, dented, or even clogged by plastic particles after prolonged impact, leading to cleaning difficulties and disassembly failure. In addition, under high-speed vibration, if the machining accuracy is slightly off, the side-locking screws can gradually loosen, causing blade wobble, uneven particle size, and even safety accidents.

[0004] Another known technology is "copper sheet pressing." This technology utilizes the soft ductility and high coefficient of thermal expansion of copper. A copper sheet is first inserted between the blade and the blade body, and then a hydraulic press applies high pressure to deform the copper sheet and fill the groove in the blade body, thus firmly embedding the blade. During operation, the ambient temperature rises to 120 to 130°C, and the copper sheet generates greater lateral compressive force due to thermal expansion, making the blade more and more secure and preventing it from falling off during high-speed rotation. Although this technology can provide good initial fixing force, it has fundamental drawbacks. First, customers cannot replace the blades themselves. After the blades wear out or chip, the entire set of tools must be sent back to the original manufacturer, and a special hydraulic press can be used to eject the copper sheet and press in a new blade, resulting in high logistics costs and downtime of several days. Second, copper sheet pressing relies on professional hydraulic press equipment, which is generally not available in small and medium-sized plastic factories, making maintenance extremely difficult.

[0005] Another major shortcoming of conventional technology lies in the failure to properly control the thermal expansion coefficient of materials and the position of screws. During pelletizing operations, the ambient temperature can reach 120 to 130°C. If materials with excessively high thermal expansion coefficients are used, the gap between the blade and the blade body will often expand excessively, causing the blades to collide, chip, or damage the machine body. Conversely, if high-expansion materials such as copper sheets are not used, the fixing force is insufficient, and the blades are prone to falling off during high-speed rotation. If a screw-locking design is used, the position of the screw is even more critical. Exposed screws are directly exposed to the impact zone of plastic particles, and the wear rate is much higher than that of side-locking designs. Side-locking, on the other hand, has a very high risk of loosening due to vibration and tolerance accumulation. These problems significantly shorten the average lifespan of conventional tools, increase the frequency and time of maintenance, and indirectly drive up the overall production costs of the factory.

[0006] Another known technique involves a wedge-shaped fixing method. This method does not utilize materials with a high coefficient of thermal expansion; instead, it uses a wedge to hold the blade in place on the blade body. The wedge is typically positioned between two blades to secure them. Compared to direct screw fastening or copper sheet pressing techniques, this wedge-shaped fixing method reduces the number of exposed fasteners and can improve the stability of the blade's fixation to some extent.

[0007] However, the above-mentioned method of fixing wedge-shaped parts still has some problems in practical applications. In some conventional designs, screws are used to lock the wedge-shaped parts. However, as with the problems of the conventional technology mentioned above, when the screw is in the cutting area and encounters plastic particles that hit the inner wall of the cutting machine at high speed after cutting, it may still cause continuous impact and wear on the screw. Especially under long-term operation, if the nut is worn or deformed by impact, it will affect the disassembly and assembly of the tool, and may even cause the screw to be unable to be unscrewed smoothly, thereby increasing maintenance difficulties and downtime.

[0008] Furthermore, in some conventional designs, cap elements are used to seal the screw holes, thereby reducing the wear and tear on the nuts from impacts. However, this design also increases structural complexity and cost. Specifically, the cap element usually needs to be additionally installed on the surface of the cutter body and assembled corresponding to the screw hole position, so that the nut can be shielded inside the cap to reduce the probability of plastic particles directly impacting the nut. However, the cap element itself is also exposed in the pelletizing area, and after long-term operation, it may still be subjected to repeated impacts from plastic particles, resulting in wear or deformation. Once the cap element is damaged or loosened, it will not only fail to effectively protect the nut, but broken fragments may also enter the pelletizing area, affecting product quality or causing equipment malfunctions.

[0009] In summary, while existing cutting machine blade structures can achieve blade fixation through screw locking, copper sheet pressing, or wedge-shaped support, under prolonged pelletizing operations, it is still difficult to effectively prevent the fixing components (screws) from being repeatedly impacted by plastic particles due to being in or near the cutting area, resulting in wear and deformation. Therefore, how to provide a solution that can effectively reduce the impact of plastic particle impacts on the fixing components is a pressing problem that manufacturers in the cutting machine field need to solve.

[0010] To address the aforementioned issues, this invention provides a cutting tool structure for a cutting machine. It utilizes a hollow cutting tool housing with a cutting groove and a fixing groove, and employs a wedge-shaped member to hold the cutting tool in place. By inserting a fixing member through the inner side of the hollow cutting tool housing, the wedge-shaped member is screwed into the fixing groove. This effectively fixes the cutting tool in the cutting tool housing and avoids wear and deformation problems of the screw holes or fixing screws on the cutting tool housing. Summary of the Invention

[0011] One objective of this invention is to provide a cutting tool structure for a cutting machine, wherein a fixing member passes through the inside of a cutting tool housing and locks a wedge-shaped member therein, so as to avoid wear problems caused by the fixing member being impacted by plastic particles.

[0012] To achieve the above objectives, this invention discloses a cutting tool structure for a cutting machine, wherein a plurality of blade sets are arranged around the outer side of a blade body housing, each blade set comprising two blades, a wedge-shaped component, and a fixing component, and a plurality of fixing holes corresponding to the blade sets are provided on the inner side of the blade body housing, wherein the fixing component passes through the fixing holes and screws the wedge-shaped component, thereby reducing the wear of the fixing component and fixing holes and improving the convenience of blade replacement and maintenance.

[0013] This invention provides an embodiment in which the blade housing and the wedge-shaped components are selected from stainless steel materials with low thermal expansion or corrosion resistance.

[0014] This invention provides an embodiment in which the blade assemblies are arranged at equal intervals along the outer side of the blade body housing.

[0015] This invention provides an embodiment in which the wedge-shaped member is provided with a first contact surface that contacts one of the two blade members and a second contact surface that contacts the other of the two blade members.

[0016] This invention provides an embodiment in which the wedge-shaped member and the fixing groove are provided with a gap space.

[0017] This invention provides an embodiment in which the width of one of the blade assembly is the same as the width of one of the blade housings.

[0018] This invention provides an embodiment in which two openings are provided at both ends of the two accommodating grooves and the fixing groove. Simple Explanation of the Diagram

[0019] Figure 1: It is a schematic diagram of the cutting tool structure of a cutting machine according to one embodiment of this invention; Figure 2: This is an enlarged schematic diagram of the tool structure of one embodiment of this invention, within the dotted frame A in Figure 1; and Figure 3: A cross-sectional view of the tool structure of one embodiment of this invention within the dashed frame A of Figure 1. Implementation

[0020] To enable your review committee to gain a better understanding of the features and effects of this creation, the following detailed description is provided with examples and accompanying drawings:

[0021] First, please refer to Figure 1, which is a schematic diagram of the cutting tool structure of a cutting machine according to one embodiment of this invention. The cutting tool structure of this invention consists of a plurality of blade sets 100 arranged around the outer side of a blade body shell 1, and a hollow body 2 provided on the inner side of the blade body shell 1, with a plurality of fixing holes 3 passing through the blade sets 100 on the inner side.

[0022] Continuing from the above, the blade sets 100 are arranged in a circumferential manner along the outer side of the blade housing 1 at equal intervals, and the width of each blade set 100 is the same as the width of the blade housing 1, so as to improve the stress stability of each blade set 100 and the uniformity of cutting during the cutting process.

[0023] See Figure 2 for a further view, which is an enlarged schematic diagram of the tool structure of one embodiment of this invention within the dashed frame A in Figure 1. During installation, the two blade pieces 106 are first protruded into the two blade grooves 102 respectively, and the two blade pieces 106 are positioned in the corresponding positions. Then, the wedge-shaped piece 108 is protruded into the fixing groove 104, and the wedge-shaped piece 108 is positioned between the two blade pieces 106. The wedge-shaped piece 108 holds the two blade pieces 106, and the two blade pieces 106 are clamped between the wedge-shaped piece 108 and the blade body housing 1. Next, the fixing piece 110 passes through one of the fixing holes 3 from the inner side of the blade body housing 1 and is screwed into one of the screw holes 1082 on the inner side of the wedge-shaped piece 108, so that the wedge-shaped piece 108 is locked in the fixing groove 104, so as to avoid the problem of the wedge-shaped piece 108 loosening due to external force, vibration or centrifugal force generated by rotating cutting.

[0024] Continuing from the above, the two blade grooves 102 and the fixing groove 104 are provided with two openings at their respective ends, so that the two blades 106 and the wedge-shaped member 108 can be installed or removed through the two openings, thereby improving the maintenance convenience of the two blades 106 and the wedge-shaped member 108.

[0025] Continuing from the above, when the tool structure is in use, the two blades 106 may experience partial breakage, chipped corners, or dulling due to cutting operations, requiring replacement. In this case, simply remove the retaining member 110 from the wedge-shaped member 108, and the wedge-shaped member 108 can be removed from the retaining groove 104, thereby disassembling the two blades 106 to facilitate subsequent replacement or grinding operations. In this way, the present invention achieves the goal of completing the blade maintenance operation without the use of additional high-pressure equipment or special tools.

[0026] Furthermore, since the fixing member 110 is screwed onto the inner side of the blade housing 1 to secure the wedge-shaped member 108, and the hollow body 2 is provided with a rotating shaft, the fixing member 110 is positioned in a position where it is not impacted by plastic particles. This avoids the fixing member 110 from being worn or deformed due to impact during long-term operation. The rotating shaft is used to drive the blade structure to perform the cutting operation. However, this invention only relates to the blade structure, while the operation, configuration, and drive device of the cutting machine can be any known type. Therefore, those skilled in the art can fully understand this invention without a detailed description and demonstration of the cutting machine.

[0027] In addition, since the fixing member 110 and the fixing hole 3 are both located on the inner side of the blade body housing 1, when changing materials (such as changing to plastic raw materials of different colors or materials), plastic particles can be prevented from remaining inside the fixing member 110 or the fixing hole 3, thereby reducing the risk of mixing materials and improving the reliability of cleaning operations.

[0028] Next, please refer to Figure 3, which is a cross-sectional view of the tool structure of one embodiment of this invention within the dashed frame A of Figure 1. After the wedge-shaped member 108 is screwed into the fixing groove 104 via the fixing member 110, a first contact surface 1084 and a second contact surface 1086 provided on the wedge-shaped member 108 respectively abut against the two cutting blades 106, so that the two cutting blades 106 are simultaneously pushed by the first contact surface 1084 and the second contact surface 1086, thereby improving the stability of the two cutting blades 106.

[0029] Continuing from the above, a gap space 1042 is provided between the wedge-shaped member 108 and the fixing groove 104, so as to avoid the decrease in clamping stability of the wedge-shaped member 108 due to machining tolerance.

[0030] In this embodiment, the wedge-shaped component 108 and the blade housing 1 are made of the same stainless steel material, such as stainless steel with a low coefficient of thermal expansion or corrosion resistance, to maintain the consistency of the material in the tool structure. Furthermore, if impurities or contamination occur during the cutting process, it is easier to identify the source of contamination, thereby improving process traceability. In addition, to enhance durability and wear resistance, the surfaces of the wedge-shaped component 108 and the blade housing 1 can be selectively coated with tungsten carbide or ceramic layers, thereby further reducing wear caused by plastic particle collisions and extending the service life of the tool structure.

[0031] In another embodiment, the blade assembly 100 selects two blades 106 and wedge-shaped parts of different sizes according to different cutting requirements, without changing the structure of the blade body shell 1. In this way, the blade structure of the present invention can be adjusted according to different plastic extrusion strips or cutting conditions, thereby improving the flexibility and applicability of the blade structure.

[0032] In another embodiment, the blade assembly 100 is arranged in a spiral along the blade housing 1, so that the two blades 106 gradually cut the plastic extruded strip from one end to the other end during the rotating cutting process, thereby reducing the stress on the two blades 106 and improving their service life. In addition, by arranging the blade assembly 100 in a spiral, it can be further coordinated with the grinding process, and the two blades 106 can be ground directly without disassembling the blade assembly 100, thereby improving maintenance efficiency.

[0033] In summary, the tool structure of this invention, through the combination of two cutting blades 106 and a wedge-shaped component 108 with a fixing component 110, allows the tool assembly 100 to be stably installed on the tool body housing 1. Furthermore, by screwing the wedge-shaped component 108 from the inside of the tool body housing 1 through the fixing component 110, the fixing component 110 is less susceptible to impact from plastic particles, thereby reducing wear. In addition, the tool assembly 100 can be selected in different sizes or arranged in a spiral shape according to requirements, so that the cutting force is distributed and the service life of the two cutting blades 106 is extended, thereby improving maintenance efficiency and application flexibility.

[0034] Therefore, this creation is indeed novel, progressive, and industrially applicable, and undoubtedly meets the requirements for patent application under the Patent Law of our country. Thus, we hereby file a utility model patent application in accordance with the law, and earnestly pray that the Bureau will grant the patent as soon as possible.

[0035] However, the above description is merely a preferred embodiment of this invention and is not intended to limit the scope of this invention. All equivalent variations and modifications made to the shape, structure, features and spirit described in the claims of this invention should be included within the scope of the claims of this invention.

[0036] 1: Blade shell 100: Knife Set 102: Dual-capacity knife groove 104: Fixing slot 1042: Gap space 106: Two-blade component 108: Wedge-shaped parts 1082: Screw hole 1084: First contact surface 1086: Second contact surface 110: Fasteners 2: Hollow body 3: Fixing holes A: virtual frame

Claims

1. A cutting tool structure for a cutting machine, comprising: a tool body housing having a plurality of tool sets arranged around its outer side; a hollow body being provided on an inner side of the tool body housing, the inner side having a plurality of fixing holes corresponding to the tool sets; each of the tool sets comprising: two receiving grooves; a fixing groove being clamped between the two receiving grooves; two blade members, each protruding from the receiving groove; a wedge-shaped member protruding from the fixing groove and used to clamp each of the two blade members between the wedge-shaped member and the tool body housing, a screw hole being provided on an inner side of the wedge-shaped member; and a fixing member being correspondingly provided in one of the fixing holes and screwing the wedge-shaped member.

2. The tool structure as described in claim 1, wherein the tool body housing and the wedge-shaped components are selected from stainless steel materials with low thermal expansion or corrosion resistance.

3. The tool structure as described in claim 1, wherein the tool sets are arranged at equal intervals along the outer side of the tool body housing.

4. The tool structure as described in claim 1, wherein the wedge is provided with a first contact surface that contacts one of the two cutting tools and a second contact surface that contacts the other of the two cutting tools.

5. The tool structure as described in claim 1, wherein the wedge and the fixing groove are provided with a gap space.

6. The tool structure as described in claim 1, wherein the width of one of the tool sets is the same as the width of one of the tool body housings.

7. The tool structure as described in claim 1, wherein the two tool grooves and the fixing groove are provided with two openings at their respective ends.

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