Cutting tool, fastening system, forming tool and use of a cutting tool

Abstract

Cutting tools, especially hole punches, comprising a base body (20) and an additional body (30), wherein the base body (20) extends along a longitudinal axis (L) and ends in a first end face (21) and in a second end face (22), wherein the second end face (22) is arranged inclined and / or offset relative to the first end face (21), and wherein the additional body (30) ends in a third end face (31) which is arranged laterally offset to the second end face (22), wherein the additional body (30) is arranged radially offset to a center line (M) of the base body (20).

Description

[0001] The present invention relates to a cutting tool, in particular a punch, a fastening system, a forming tool and a use of a cutting tool.

[0002] Cutting tools or hole punches of the type in question are generally known from the prior art. Such tools are used in particular for piercing or punching holes, openings, etc. Such tools can be operated manually. However, it is also common to integrate such tools into other tools, for example in the mold halves of internal high-pressure tools. This makes it possible, for example, to produce a hole simultaneously during the internal high-pressure forming process. Different process variants are generally known, for example piercing “inwards”, piercing “outwards” and piercing “with a slug remaining on the component”. The latter process is described, for example, in DE 197 19 426 A1. Here, a hole orThe cutting tool is blunt at one point on the punched edge, leaving a connection in part of the hole area. This folds the punched slug inward and remains connected to the board, preventing it from remaining loose in the hollow body. The problem with this is that the folded punched slug prevents attachments, such as a mounting plug, from being inserted. This may require a further processing step, such as a mechanical one, which entails additional costs.

[0003] EP 1 979 108 B1 relates to a punching tool for forming opposing holes in a hollow part, wherein the part is pressurized internally by hydroforming fluid, and wherein the punching tool is designed to punch opposing holes in a hollow body.

[0004] DE 10 2007 046 055 A1 relates to a punching tool for an internal high-pressure forming tool, wherein the punching tool has a thumbnail-shaped slot extending axially and radially into the head to allow a fluid in a tubular element to drive a wall portion of the tubular element outwardly into the slot of the punching tool and to be sheared by the punching tool to create an opening in the tubular element.

[0005] US 6,109,086 A relates to a punching tool which is designed to form conically shaped punching holes.

[0006] DE 197 19 426 A1 relates to a method and a device for producing a hollow body, in which at least two blanks, preferably made of sheet metal, are held tightly against one another along an at least almost closed line, the hollow body is formed by means of an internal high-pressure forming process and the blanks connected to one another are clinched.

[0007] It is therefore an object of the present invention to provide a cutting tool, a fastening system, a forming tool and a use of a cutting tool which eliminate the aforementioned disadvantages and are efficient and cost-effective.

[0008] This object is achieved by a cutting tool according to claim 1, by a fastening system according to claim 8, by a forming tool according to claim 10 and by a use according to claim 11. Further advantages and features emerge from the subclaims as well as the description and the attached figures.

[0009] According to the invention, a cutting tool, in particular a hole punch, comprises a base body and an additional body, wherein the base body extends along a longitudinal axis and ends in a first end face and in a second end face, wherein the second end face is arranged inclined and / or offset to the first end face, and wherein the additional body ends in a third end face which is arranged or formed laterally offset to the second end face. In other words, the third end face is arranged or formed next to or laterally to the second end face, wherein the third end face can also be formed, for example, directly adjacent to the second end face. Relative to a center line of the base body, the additional body is arranged or formed radially offset.

[0010] The first end face is bordered by a punching edge which is blunt in some areas. The second end face is formed in the blunt area or the second end face forms this blunt area. This makes it possible for the hole or opening, the shape of which is essentially determined or predetermined by the cross-section of the base body, to not be completely punched out. Advantageously, the third end face is now provided (adjacent to this), which is designed to fold the punching slug away to the side or over, so that it is possible to attach add-on parts such as mounting plugs, etc. in a fastening opening created in this way. The third end face therefore functions as a type of impact surface which, when the cutting tool moves into a workpiece, moves the punching slug away from the cutting tool in relation to the longitudinal axis orThe direction of movement of the cutting tool is shifted essentially radially.

[0011] According to one embodiment, the first end face is arranged substantially perpendicular to the longitudinal axis. The end face is preferably flat or smooth. Alternatively, the end face may also have a curvature, at least in some regions. The same applies to the second end face, which is formed adjacent to the first end face. A transition region is preferably formed between the first end face and the second end face, which transition region may be formed as a substantially straight edge. This "edge" may also be formed as a radius to create a substantially continuous transition.

[0012] According to one embodiment, the third end face is arranged inclined and / or offset relative to the first end face, in particular offset along the longitudinal axis. Relative to a cross-section of the base body, the additional body thus creates a kind of projection, which allows the punched slug to be pushed away. The actual design of the third end face can be chosen largely freely, as it depends in particular on the geometry of the base body and the geometry of the attachment to be attached later.

[0013] According to one embodiment, the second end face and the third end face merge into one another, whereby "merging into one another" means, in particular, a seamless transition. In this respect, the second end face can also contribute to pushing away the punched slug. According to a preferred embodiment, the second and third end faces thus form a common surface that is inclined relative to the first end face.

[0014] According to one embodiment, the cross-section of the base body is round, in particular circular or angular, in particular square, pentagonal, or hexagonal. Typical diameters range from approximately 4-15 mm. The substantially square or, in particular, rectangular cross-section of the base body, which results in a substantially square fastening opening, advantageously enables the insertion of an expansion nut. Analogously and accordingly, a substantially round base body enables the use of a mounting plug, a substantially hexagonal base body enables the arrangement of a (hexagonal) blind rivet nut, while a substantially rectangular cross-section of the base body is advantageous for the use of a cage nut.

[0015] According to one embodiment, a cross-section of the additional body is round, in particular circular or angular, in particular quadrangular, such as square or rectangular. In preferred embodiments, a basic cross-section of the additional body essentially corresponds to a basic cross-section of the base body. For the arrangement of a mounting plug, a substantially circular segment-shaped cross-section of the additional body has proven advantageous; for the arrangement of an expansion nut, a substantially quadrangular cross-section; for the arrangement of a cage nut, a substantially rectangular cross-section; and for the arrangement of a (hexagonal) blind rivet nut, a substantially hexagonal cross-section.

[0016] With regard to the additional body, it should also be mentioned that this also preferably extends along the longitudinal axis, in particular parallel to the base body. The cutting tool is preferably a one-piece tool that forms the base body and the additional body. The corresponding cutting geometry, including the various end faces, etc., is then preferably produced by subsequent machining of a corresponding tool blank. Depending on the type and use of the cutting tool, it expediently also includes a suitably designed connection area for connecting to an actuating device, etc. In particular, a driving notch is provided, for example.

[0017] According to one embodiment, several additional bodies can also be provided, for example arranged side by side, particularly if the base body has a rather elongated cross-sectional shape. The additional bodies, for example two or three, are then advantageously arranged on the longer edge of the base body.

[0018] According to one embodiment, an angle between the first end face and the third end face or the second end face lies in a range of approximately 100-130°, preferably in a range of approximately 110-128°. For example, an angle in a range of approximately 123-128° has proven advantageous for the arrangement of an expansion nut; an angle in a range of approximately 110-118° for the arrangement of a mounting plug; and an angle in a range of approximately 109-115° for the arrangement of a cage nut (Prestole cage) or a blind rivet nut.

[0019] The advantageous geometries of the base body and the additional body have already been described.

[0020] The invention further relates to a fastening system comprising a fastening element that is arranged or can be arranged in a fastening opening of a component, wherein the fastening opening is punched such that the punched slug remains at the fastening opening. Preferably, a cutting tool according to the invention is used to produce such a fastening opening, which allows fastening elements, such as add-on parts in the form of mounting plugs, etc., to be inserted or attached into the fastening opening even though the punched slug has not been removed.

[0021] According to one embodiment, the fastening element is an expansion nut, a mounting plug, a cage nut, or a blind rivet nut. The advantages and features mentioned in connection with the cutting tool apply analogously and accordingly to the fastening system according to the invention, and vice versa.

[0022] The invention also relates to a forming tool for producing components formed by internal high-pressure forming, comprising at least one cutting tool according to the invention. The forming tool is preferably a mold half of an internal high-pressure forming tool. This tool expediently has at least one cutting tool according to the invention on an inner contour, which forms an outer contour of the subsequent component, which is movable relative to the inner contour of the corresponding mold half, whereby a fastening opening can be produced / punched during and / or after the actual internal high-pressure forming process of the component. Typical internal pressures are in the range of approximately 1600 bar. The pressure is introduced into the hollow body, for example, via an oil-water emulsion.

[0023] The invention also relates to the use of a cutting tool according to the invention for producing a fastening opening in a vehicle component, in particular, for example, an axle carrier of a passenger car. According to a preferred embodiment, the axle carrier is a component that is at least partially or partially formed by internal high pressure, in particular, for example, made of a metal such as steel or aluminum.

[0024] Typical (component) wall thicknesses range from approximately 2 to 3 mm. The internal pressure used, which acts as support pressure during punching, depends, among other things, on the wall thickness, the punch geometry, and the respective material. For wall thicknesses of 2 to 3 mm and the use of a steel material (e.g., S 355), internal pressures in the range of approximately 1600 bar have proven advantageous.

[0025] Further advantages and features will become apparent from the following description of preferred embodiments of cutting tools with reference to the accompanying figures. Different features can be combined within the scope of the invention.

[0026] They show: Fig. 1: several illustrations which, using the example of an expanding nut, illustrate the functioning of an embodiment of a cutting tool; Fig. 2: two detailed views of the cutting tool from Fig. 1; Fig. 3: several representations which, using the example of a mounting plug, illustrate the functioning of an embodiment of a cutting tool; Fig. 4: two detailed views of the cutting tool from Fig. 3; Fig. 5: several illustrations which, using the example of a cage nut, illustrate the functioning of an embodiment of a cutting tool; Fig. 6: two detailed views of the cutting tool from Fig. 5; Fig. 7: two illustrations which illustrate the functioning of one embodiment of a cutting tool using the example of a blind rivet nut.

[0027] Fig. 1 shows a fastening element 60 in the form of an expanding nut 61. In the middle, a tubular component 40 is indicated, through the outer wall of which a cutting tool, comprising a base body 20 and an additional body 30, penetrates. For fastening or actuating the cutting tool, this comprises a connection area 24. It can be clearly seen that when the cutting tool moves into the component 40 or its outer wall, a fastening opening 42 is formed, the geometry of which can be seen from the folded-over punching slug 44. It is clear that the "pushing to the side" of the punching slug 44 is predominantly carried out by the additional body 30. Due to its advantageous design, it is possible for the expanding nut 61 to be arranged in the fastening opening 42 produced in this way, this being made possible in particular by folding over and laterally displacing the punching slug 44, cf.The right-hand illustration shows the arrangement of the expansion nut 61 in the mounting opening 42. The punched slug 44 does not interfere with the arrangement of the mounting plug 62. Preferably, punching is performed in conjunction with an internal high-pressure forming process, which is also used to form the component 40. The applied internal high pressure acts as a support pressure during punching. With a wall thickness of approximately 2 to 3 mm, the internal high pressure is approximately 1600 bar (material: steel, e.g., S 355).

[0028] Fig. 2 shows in its left half a detailed view of a lower part of the Fig. 1 known cutting tool. The main body 20 and the laterally arranged or formed additional body 30 can be seen, both extending along a longitudinal axis L of the cutting tool. The reference symbol M denotes a center line of the main body. In the illustration chosen here, a first end face 21, a second end face 22 and a third end face 31 can be seen. An angle α is formed between the first end face 21 and the third end face 31 or the second end face 22, which angle α in the embodiment shown here is in a range of approximately 125°. The length x1 in the embodiment shown here is approximately 9.5 mm. In the right-hand half of the image, the cutting tool can be seen from below, whereby the arrangement of the first end face 21, the second end face 22 and the third end face 31 relative to one another is particularly clear. The main body 30 orIts third end face 31 has a substantially quadrangular, in particular rectangular, cross-section, with a side length x2 being approximately 4 mm in the embodiment shown here. The side lengths x4 and x5 of the substantially quadrangular, in particular square, base body 20 are approximately 9 mm in the embodiment shown here. The length x3 is advantageously approximately 6 mm. This refers to a distance from a center line of the base body 30 to an outer edge of the additional body 30.

[0029] The Fig. 3 to 4 and 5 to 6 show this essentially from the Fig. 1 and Fig. 2 known principle, whereby in the Fig. 3 and Fig. 4 a fastening element 60 is designed as a mounting plug 62 and in the Fig. 5 and Fig. 6 a fastening element 60 as a cage nut (Prestole cage) 63. In order to avoid repetition, only the essential differences are discussed below.

[0030] With reference to Fig. 4, an angle α between a first end face 21 and a third end face 31 or a second end face 22 is preferably approximately 113°, with the length x1 being approximately 10.2-10.3 mm. A diameter d2 of the base body 30 is approximately 12 mm in the embodiment shown here, with a diameter d1 of the additional body 30, which has a substantially circular segment-shaped cross-section, being in a range of approximately 8 mm. A length x2 is approximately 4 mm in the embodiment shown here.

[0031] As already mentioned, in the Fig. 5 and Fig. 6 shows the principle of an arrangement of a cage nut 63. An angle α, which is measured between a first end face 21 and a third end face 31 or a second end face 22, is approximately 112° in the embodiment shown here. The length x1 is approximately 8.14 mm. A base body 20 of the cutting tool is essentially rectangular in the embodiment shown here, with a side length x3 of approximately 13 mm and a side length x4 of approximately 9 mm. An additional body 30 is also essentially rectangular in the embodiment shown here, with a side length x2 of approximately 2 mm and a side length x5 of approximately 6 mm.

[0032] Fig.Finally, Figure 7 shows a punching tool designed for the assembly of a blind rivet nut 64. The length x1 is approximately 3 mm, the length x2 is approximately 2 mm, and the length x3 is approximately 13 mm. The angle between a third end face 31 and a first end face 21 is approximately 112°.

[0033] Ultimately, the exact geometry of the cutting tool must always be tailored to the specific application. Therefore, it is also entirely possible to combine round base bodies with square additional bodies, or vice versa. In the embodiments shown here, the second and third end faces merge seamlessly into one another. Depending on the geometry of the punched slug or the material thickness of the component into which the fastening opening must be made, it can also be advantageous for the third end face to have a different inclination, for example, be steeper or flatter than the second end face, or even be essentially parallel to the first end face. List of reference symbols 20 basic bodies 21 first frontal surface 22 second front face 24 Connection area 30 additional bodies 31 third frontal surface 40 components 42 (Mounting) opening 44 punching slugs 60 Fastener 61 Fastening element, expansion nut 62 Fastening element, mounting plug 63 Fastening element, cage nut 64 Fastening element, blind rivet nut α angle x1, x2, x3, x4, x5 lengths d1, d2 diameter L Longitudinal axis M center line

Claims

[1] Cutting tool, especially punch, comprising a base body (20) and an additional body (30), wherein the base body (20) extends along a longitudinal axis (L) and ends in a first end face (21) and in a second end face (22), wherein the second end face (22) is arranged inclined and / or offset relative to the first end face (21), and wherein the additional body (30) ends in a third end face (31) which is arranged laterally offset to the second end face (22), wherein the additional body (30) is arranged radially offset to a center line (M) of the base body (20). [2] Cutting tool according to claim 1, wherein the first end face (21) is arranged substantially perpendicular to the longitudinal axis (L). [3] Cutting tool according to claim 1 or 2, wherein the third end face (31) is arranged inclined and / or offset to the first end face (21). [4] Cutting tool according to one of the preceding claims, wherein the second end face (22) and the third end face (31) merge into one another. [5] Cutting tool according to one of the preceding claims, wherein a cross section of the base body (20) is round, in particular circular, or angular, in particular square, pentagonal or hexagonal. [6] Cutting tool according to one of the preceding claims, wherein a cross section of the additional body (30) is round, in particular circular, or angular, in particular square. [7] Cutting tool according to one of the preceding claims, wherein an angle (α) between the first end face (21) and the third end face (31) is in a range of approximately 100 to 130°. [8] Fastening system, comprising a fastening element (60) which is arranged or can be arranged in a fastening opening (42) of a component (40), wherein the fastening opening (42), produced with a punching tool according to one of the preceding claims, is punched such that a punching slug (44) remains at the fastening opening (42). [9] Fastening system according to claim 8, wherein the fastening element (60) is an expansion nut (61), a mounting plug (62), a cage nut (63) or a blind rivet nut (64). [10] Forming tool for the production of components formed by means of internal high pressure, comprising at least one cutting tool according to one of claims 1 to 7. [11] Use of a cutting tool according to one of claims 1 to 7 for producing a fastening opening (42) in a vehicle component, in particular an axle carrier.

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