Cutting tool having at least partially molded body and method of making same

Cutting tool with at least partially molded body and manufacturing method thereof

[0001] Background Technical Field

[0002] The present invention relates generally to rotary cutting tools, and more particularly to cutting tools having a generally cylindrical body, at least a portion of which is formed by a molding method. The invention further relates to a method for manufacturing such cutting tools.

Background technique

[0003] Rotary cutting tools (such as, but not limited to: drills, cutters, or end punches) are usually made of hardened tool steel, hardened tool steel coated with a secondary hardening material, or equipped with other hardened materials The hardened tool steel that forms the replaceable cutting insert is formed as a whole. Other hardened materials are such as polycrystalline diamond (PCD), polycrystalline cubic boron nitride (PCBN), ceramics, cemented carbides, and cermets. . Although such hardened materials generally produce the desired end product, the costs associated with producing such end products are generally undesirable because these hardened materials typically require a lot of time and machining in order to produce a finished product. product.

[0004] Although known rotary cutting tools have been universally suitable in many applications, there is still room for improvement. For example, when a drill made of a single piece of carbide has been used at the point where the cutting edge becomes dull, the drill must either be discarded or reconditioned. In most cases, only the cutting edges are worn and the rest of the cutting tool body is not worn. Discarding the cutting tool obviously results in the tool being no longer used. On the other hand, refinishing provides further use of the tool, but this further use is often more limited compared to the original use and is accompanied by ordinary human refinishing costs.

[0005] Therefore, there is a need for improved cutting tools.

Summary of the invention

[0006] The embodiments of the present invention set out to solve a number of deficiencies in the prior art, and these embodiments are aimed at an improved rotary cutting tool and a manufacturing method thereof.

[0007] As an aspect of the present invention, a cutting tool is provided, which performs a cutting operation on a workpiece when the machine tool rotates the cutting tool around a central longitudinal axis. This cutting tool includes: a generally cylindrical body arranged around the central axis, the generally cylindrical body having a first end and an opposite second end; and a generally cylindrical body arranged on the A cutting portion at or near the first end of the body, the cutting portion having a plurality of cutting edges structured for engagement with the workpiece during a cutting operation; and a cutting portion arranged on the generally cylindrical body The mounting part at or near the opposite second end, which is structured for connection with the machine tool. At least a part of the generally cylindrical body includes a molded part formed by a molding method. The molded part is formed around the cutting part in a manner that connects the cutting part to the generally cylindrical body.

[0008] The molded part may be formed of fibers or particles, which are randomly arranged or arranged between/in a matrix material in a predetermined layer structure.

[0009] The cylindrical body portion may include a pre-formed core portion arranged at or near the central axis, and the molded portion may be formed around the core portion. The core portion may include one of a hollow tubular member or a solid cylindrical member. The inner core part may be formed of one of steel, carbide, fiber-reinforced composite material, or particle-reinforced composite material.

[0010] The molded part may include a plurality of wear resistant elements arranged or formed therein. These wear-resistant components may be formed of at least one of PCD, PCBN, carbide, cermet, or ceramic.

[0011] The cylindrical body portion may include a plurality of chip evacuation grooves, and the molded portion may include a plurality of wear-resistant and/or heat-resistant particles arranged at or near the plurality of grooves.

[0012] The molded part may include a plurality of wear-resistant metal layers and/or spacers arranged at or near the mounting part.

[0013] The molded part may include a plurality of cooling channels formed therein.

[0014] The cutting part may include a plurality of plate members connected to the cylindrical body through the molding part, and the plurality of cutting edges may be formed in the plurality of plate members that are selectively connected to the plurality of plate members. Cutting inserts.

[0015] As another aspect of the present invention, a method for forming a cutting tool used in a rotary cutting operation is provided. The method includes: providing a mold formed by one or more mold sections, the mold having a plurality of inner surfaces that define an inner space in the mold in the shape of a cutting tool; The cutting part is fixed in the mold; a certain amount of settable material is provided in the inner space of the mold and around a portion of the cutting part to form a cutting tool in the mold; the settable material is allowed to solidify; and Remove the cutting tool from the mold.

[0016] The method may further include: placing a core portion in the mold before providing the amount of settable material in the mold, and providing the amount of settable material in the mold may include surrounding the core Partly to provide the settable material.

[0017] The method may further include: placing a plurality of tubular members in the mold before providing the amount of settable material in the mold, and providing the amount of settable material in the mold may include surrounding the mold Multiple tubular members provide the material.

[0018] This amount of settable material can be provided by an injection method.

[0019] This amount of settable material can be provided by drawing the settable material into the inner space of the mold by a vacuum method.

[0020] The method may further include providing a plurality of wear resistant elements within the settable material.

[0021] The method may include electroplating a portion of the solidified material after removing the cutting tool from the mold.

Description of the drawings

[0022] When read in conjunction with these drawings, a comprehensive understanding of the present invention can be obtained from the following description of the preferred embodiments, in the drawings:

[0023] FIG. 1 is an isometric view of a rotary cutting tool according to an exemplary embodiment of the present invention;

[0024] FIG. 2 is a cross-sectional view of the rotary cutting tool of FIG. 1 taken along line 2-2;

[0025] FIG. 3 is a cross-sectional view of a rotary cutting tool according to another exemplary embodiment of the present invention;

[0026] FIG. 4 is a cross-sectional view of a rotary cutting tool according to yet another exemplary embodiment of the present invention;

[0027] FIG. 5 is an isometric view of a part of a rotary cutting tool according to an exemplary embodiment of the present invention

view;

[0028] FIG. 6 is an isometric view of a portion of a rotary cutting tool according to another exemplary embodiment of the present invention; and

[0029] FIG. 7 is a schematic isometric view of a mold used to form a cutting tool according to an exemplary embodiment of the present invention.

Detailed ways

[0030] Directional words used here (such as: left, right, front, back, top, bottom and their derivatives) refer to the orientation of these components shown in the drawings, and are not limited to the claims , Unless explicitly quoted here. The same components are provided with the same reference numbers in all the drawings.

[0031] As used herein, the term "number" refers to any non-zero number (ie, one or any number greater than one).

[0032] FIG. 1 depicts an exemplary cutting tool according to a non-limiting embodiment of the present invention, the cutting tool is used to rotate the cutting tool 10 about a central longitudinal axis 11 in a workpiece (not shown) ) To perform a rotating cutting operation. The cutting tool 10 includes a generally cylindrical tool body 12 having a first end 14 and an opposite second end 16. Although the cutting tool 10 is shown in the form of a comparative tool, it should be recognized that the concepts described herein can also be applied to other rotary cutting tools, such as but not limited to drill bits (e.g., single-slot, multi-slot) , Spiral, linear), modular drills, graded drills, end punches, flat punches, grooving tools, turning tools, drill rods, routers, taps, and circular saws.

[0033] With continued reference to FIG. 1, the cutting tool 10 includes a cutting portion 17 generally arranged at or near the first end 14, the cutting portion being structured to be combined with a workpiece (not shown) and When the cutting tool 10 rotates about the central longitudinal axis 11, a cutting operation is performed on the workpiece. In the illustrated embodiment, the cutting portion 17 includes a plate member 18 arranged generally perpendicular to the axis 11, the plate member having a plurality of plates formed as a part thereof or connected thereto (permanently or selectively). (Two in the illustrated embodiment) Cutting part 20. When the cutting tool 10 is depicted as a sharper in the embodiment shown in FIG. 1, these cutting portions 20 include two sharper inserts, each of which is selectively connected to the plate member 18, Each insert can be selectively removed or replaced as needed due to wear or tear during use. Such selective attachment can be accomplished by various means commonly used in the art to attach removable inserts to cutting tools.

[0034] Continuing to refer to FIG. 1, the cutting tool 10 further includes a mounting portion 22 generally arranged at or near the second end 16, the mounting portion being adapted to be mounted on a chuck Or other similar parts of the machine tool are used to rotate the cutting tool 10 around the axis 11. One or more grooves 23 extending from the cutting portion 17 to the mounting portion 22 may be provided in the tool body 12 to assist in the evacuation of chips formed during the cutting operation. Although a plurality of straight grooves are shown in the depicted exemplary embodiment, it should be appreciated that the grooves provided in the tool body 12 may also be spiral, have different amounts, or other suitable arrangements, and not Without departing from the scope of the present invention. It should be appreciated that the cutting tool 10 may include any or all of the features previously described, as well as many other features of known cutting tools not specifically mentioned herein, without departing from the scope of the present invention.

[0035] The difference between the cutting tool 10 and the known cutting tool is that all or at least a part of the cylindrical body 12 is formed in a completed or semi-finished state by a molding method. As shown in the cross-sectional view in FIG. 2, the entire tool body 12 of the cutting tool 10 is formed as a molded part 24 formed by a molding method. Such

The molding method is performed using a mold, such as the mold 25 schematically depicted in FIG. 7. The mold 25 includes a plurality of inner surfaces 26 that define an inner space 28 in the form of the outer shape of the cutting tool 10. The mold 25 is preferably formed of an appropriately rigid or semi-rigid material such as those commonly used to form molds, and may be formed of multiple parts (not numbered) or include multiple parts, which may be connected together. The mold 25 is formed and then separated to facilitate removal of the formed cutting tool 10. The mold 24 includes one or more connecting structures 30 for fixing the cutting portion 17 of the cutting tool 10 in a precise position within the internal space 28 . Although only shown as an example in FIG. 7, this or this type of connection mechanism may include a clamp, a screw-type precision positioning member, glue, or a pin.

[0036] Preferably, the molded part 24 is formed of a composite material. For example, the molded part 24 may be formed of fibers or particles, which are randomly arranged or arranged in a predetermined layer structure between/in a settable matrix material. Such a settable matrix material may be pre-impregnated with fibers and subsequently set during further processing, or preferably provided into the mold 25 by injection or vacuum methods and then allowed to set. Examples of suitable materials that can form the molded portion 24 include, but are not limited to: reinforced plastics, carbon fiber composite materials, metal matrix composite materials, and metal alloys.

[0037] In addition, all or selected parts of the molded part 24 may be formed of selected materials that are particularly resistant to high temperatures or abrasion. For example, the area near the cutting portion 17 is usually subjected to high heat and abrasive debris from the cutting operation. Likewise, the chip-emptying portions of the tool body 12 (for example, the groove 23) are usually subjected to such conditions. The portion 24 of the molded portion 24 of FIG. 1 shows some non-limiting examples of such regions, which are desirably formed of heat/wear resistant materials.

[0038] FIGS. 3 and 4 show an exemplary cutting tool 10 according to other embodiments of the present invention, and a cross-sectional view of 10", which incorporates similar to the cutting tool 10 but formed in a slightly different manner Features (such as but not limited to groove 23). More specifically, cutting tools 10, and 10" show exemplary embodiments, in these embodiments the tool body 12, and 12" are formed by a central core surrounding the preform The portion 52 is formed by the molded portion 50. In this type of example, the molded portion 50 is generally shaped as previously discussed. As shown in the exemplary embodiment of FIG. 3, the core 52 may It is formed by a solid cylindrical member 60. As shown in the exemplary embodiment of Fig. 4, the core 52 may also be formed by a hollow tubular member 70. In either case, the core 52 is preferably made of steel, Carbide, fiber-reinforced composite material, particle-reinforced composite material, or other suitable materials. The core 52 may be initially provided in a stress-free state or alternatively may be in the vicinity of the molded part 50 before it is formed. Prestressed. For example, the core 52 may be initially placed in a mold such as the mold 25, and placed in a radially stressed condition (for example, twisted) before the molded part 50 is formed in its vicinity. This prestress of 52 can be used to modify bending or torsion behavior.

[0039] The hollow tubular member 70 may be used as a coolant passage to provide a flow of coolant through the tool body 12" to the cutting portion of the cutting tool 10" as a whole. As an alternative, in certain applications, the tubular member 70 may be used to provide a means for evacuating internal chips from the cutting area adjacent to the cutting portion of the cutting tool 10".

[0040] In order to increase the durability and overall performance of the cutting tool 10, one or more wear-resistant elements are arranged or formed therein. Such wear-resistant components can be (for example, but not limited to) formed by one or more of PCD (polycrystalline diamond), PCBN (polycrystalline cubic boron nitride), carbide, cermet, ceramic, or other suitable materials . For example, abrasion-resistant and/or heat-resistant particles can be incorporated into the molded part adjacent to these grooves to help protect these grooves from

The heat formed during the cutting process contacts with the abrasive debris and deforms, as described above with respect to part 24 of FIG. 1. Similarly, the portions of the molding material at or near the grooves may be coated by an electroplating method after the cutting tool has been formed in the mold 25 and subsequently removed therefrom, in order to provide additional protection to these areas.

[0041] As another example, as shown in FIG. 5, the molded part may include a plurality of wear-resistant metal layers and/or a plurality of wear-resistant metal layers arranged at or near the mounting part 22 of the cutting tool 10", The spacer 70 is to increase the strength/wear resistance of the cutting tool at or near the location where it will be installed in the machine tool (not shown).

[0042] As yet another example, as shown in FIG. 6, the molded part may include therein a plurality of resistant molds molded at or near the leading end (ie, the first end 14) of the cutting tool. Wear parts 72, which serve as guide pads for the cutting tool. Therefore, the portion 72 will typically extend slightly outward from the tool body 12.

[0043] In addition to wear-resistant elements, other beneficial elements can also be easily incorporated into the molded part of the cutting tool body. As an example, a plurality of rigid or semi-rigid tubular members may be provided in the mold 25 so that the molded part will be formed in its vicinity as a whole. Once the molded part is formed and the cutting tool is removed from the mold, such tubular member can be used as a cooling channel to help lower one or both of the tool body or the cutting part during the cutting operation temperature.

[0044] Although the specific embodiments of the present invention have been described in detail herein, those of ordinary skill in the art should recognize that in view of the overall teaching content of the present disclosure, different modifications and alternatives to these details can be developed. . Therefore, the specific arrangements disclosed are merely illustrative, and not as a limitation on the scope of the present invention, which shall be encompassed in the full breadth of the appended claims and any and all equivalents thereof.

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