Tool holder

Abstract

A C-shaped tool holder consisting of an integral frame structure that is delimited by an inner and an outer edge, each C-shaped, in which the C-shaped edges are made from and are connected to each other by at least five multiple-vertex frame bodies that are integrated into the frame structure, in particular triangles, quadrilaterals and pentagons, wherein in each case an inner side of the individual multiple-vertex frame bodies is a connecting surface, continuously curving along a circumferential direction, along the sides of the respective multiple-vertex frame body, and the inner and the outer C-shaped edge is each delimited to the outside by a continuously curving lateral surface.

Claims

1. A C-shaped tool holder consisting of an integral frame structure that is delimited by an inner and an outer edge, each C-shaped, in which the C-shaped edges are made from and connected to each other by at least five multiple-vertex frame bodies that are integrated into the frame structure, wherein in each case an inner side of the individual multiple-vertex frame bodies is a connecting surface, continuously curving along the circumferential direction, along the sides of the respective multiple-vertex frame body, and the inner and the outer C-shaped edge is each delimited to the outside by a continuously curving lateral surface.

2. The tool holder according to claim 1, the C-shape of which consists of a first and a second leg arranged opposite each other and a connecting leg, wherein the connecting leg connects the first and the second leg to each other to form a C-shape.

3. The tool holder according to claim 2, the connecting leg of which consists of at least two frame triangles and one multiple-vertex frame body, and the first and second leg of which each consist of at least one multiple-vertex frame body.

4. The tool holder according to claim 3, the connecting leg of which consists of at least four frame triangles and one frame quadrilateral, and the first and second leg of which each consist of at least one frame quadrilateral or one frame pentagon.

5. The tool holder according to claim 3, the multiple-vertex frame bodies of which each enclose a free space having a surface that is surrounded by a bar structure with a depth and a width, the depth of which is defined orthogonally to the surface and the width of which is defined parallel to the surface, wherein the depth surfaces of the multiple-vertex frame bodies that are arranged opposite each other, are spaced apart from each other by the width of the bar structure and run parallel to the depth form continuously curving frame surfaces.

6. The tool holder according to claim 5, the depth surfaces of which, considered in the depth direction, form an inner and an outer contour line per multiple-vertex frame body that are each defined as a periodic fourth order NURBS curve on the basis of a plurality of generated junction points at least in corner areas of the respective multiple-vertex frame body.

7. The tool holder according to claim 3, the connecting leg of which consists of at least four frame triangles and one frame quadrilateral, and the first and second leg of which each consist of at least one frame quadrilateral or one frame pentagon and the multiple-vertex frame bodies of which each enclose a surface that is surrounded by a bar structure with a depth and a width, the depth of which is defined orthogonally to the surface and the width of which is defined parallel to the surface, wherein the depth surfaces of the multiple-vertex frame bodies that are arranged opposite each other, are spaced apart from each other by the width of the bar structure and run parallel to the depth form continuously curving frame surfaces.

8. The tool holder according to claim 7, the depth surfaces of which, considered in the depth direction, form an inner and an outer contour line per multiple-vertex frame body that are each defined as a periodic fourth order NURBS curve on the basis of a plurality of generated junction points at least in corner areas of the respective multiple-vertex frame body.

9. The tool holder according to claim 2, the connecting leg of which consists of at least four frame triangles and one frame quadrilateral, and the first and second leg of which each consist of at least one frame quadrilateral or one frame pentagon.

10. The tool holder according to claim 2 in which the first and the second leg each has a free end, wherein a drive unit or an attachment unit is provided integrally or modularly on at least one end.

11. The tool holder according to claim 1 that is produced integrally from metal or from a hybrid fiber-reinforced plastic (FRP) or a fiber-plastic composite (FPC).

12. The tool holder according to claim 1, in which the multiple-vertex frame bodies are triangles, quadrilaterals and pentagons.

13. A joining device that has a C-shaped tool holder according to claim 1 with a drive unit and a counter bearing.

14. The joining device according to claim 13, in which the joining device is a rivet setting device and the counter bearing is a die.

15. A design method of a C-shaped tool holder according to claim 1 with an integral frame structure that is delimited by an inner and an outer edge, each C-shaped, with the following steps: a. Defining a first and a second leg that are arranged opposite each other and are connected with a connecting leg to form a C-shaped structure, b. Forming the first and the second leg as well as the connecting leg from at least five multiple-vertex frame bodies that are connected to each other, and c. Forming a C-shaped outer edge and a C-shaped inner edge of the tool holder consisting of the multiple-vertex frame bodies that are connected to each other by a continuously curving C-shaped outer lateral surface and a continuously curving C-shaped inner lateral surface, as well as d. Forming the individual multiple-vertex frame bodies each with a continuously curving inner frame surface.

16. The design method according to claim 15 with the further steps: Defining each multiple-vertex frame body in a common design plane as a frame polygon and Defining an offset contour within the design plane that is spaced apart on both sides from the frame polygon so that the offset contour determines a width of the multiple-vertex frame body within the design plane and is composed of two offset polygons.

17. The design method according to claim 16 in which the width of the offset contour on the individual sides of the frame polygon is the same or different.

18. The design method according to claim 16 with the further steps: Generating junction points at the corners and in the middle of the sides of the offset polygons and Generating periodic fourth order NURBS curves consisting of third degree polynomials on the basis of the generated junction points.

19. The design method according to claim 15 with the further step of computer-based implementing of the design method and creating a computer-based data set for producing the tool holder.

20. A production method of a C-shaped tool holder according to claim 1 with an integral frame structure, having the following steps: a. Receiving a computer-based data set from a CAD system for the C-shaped tool holder to be produced, b. Forwarding the computer-based data set to a production machine, and c. Producing and finishing the C-shaped tool holder according to the computer-based data set.

Description

5. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

(1) Some embodiments of the present invention are described more closely with reference to the accompanying drawings. They show:

(2) FIG. 1 shows a schematic side view of an embodiment of the C-shaped tool holder,

(3) FIG. 2 shows a sectional enlargement from the tool holder according to FIG. 1 in which continuously curving surface progressions are compared to circular arc/line progressions,

(4) FIG. 3 shows the enlarged view from FIG. 2 in which only the continuously curving surfaces are shown,

(5) FIG. 4 shows a schematic representation of an embodiment of a design of the tool holder according to FIG. 1 composed of a plurality of multiple-vertex frame bodies integrated into the frame structure, each as a frame polygon,

(6) FIG. 5 shows an assembly of the multiple-vertex frame bodies according to FIG. 4 composed of multiple triangles, quadrilaterals and at least one pentagon for designing the first and second leg that are connected to each other by a connecting leg,

(7) FIG. 6a-d shows a design of a multiple-vertex frame body from the tool holder according to FIG. 1 based on a frame polygon and an offset contour surrounding this frame polygon with continuously curving side surfaces,

(8) FIG. 7 shows an embodiment of a frame triangle designed from a frame polygon and a surrounding offset contour with continuously curving side surfaces that are defined by periodic 4th order NURBS curves on the basis of a plurality of generated junction points in the corner areas and in the middle of the sides of the offset polygons,

(9) FIG. 8 shows an embodiment of a triangular frame polygon,

(10) FIG. 9 shows an embodiment of the illustration of a deformation of the frame polygon from FIG. 8 with an offset contour,

(11) FIG. 10 shows an embodiment of a frame polygon in the form of a quadrilateral,

(12) FIG. 11 shows a schematic illustration of a deformation of the frame polygon according to FIG. 10 with the surrounding offset contour,

(13) FIG. 12 shows another schematic illustration of a deformation of a frame polygon in the form of a pentagon with offset contour,

(14) FIG. 13 shows a schematic illustration of a deformation of the tool holder from FIG. 1, and

(15) FIG. 14a, b shows a comparison of mechanical stresses at a junction point (A) with continuously curving connecting surfaces between adjacent bar elements and (B) with circular arc/line transitions, meaning continuously tangential transitions, between adjacent bar elements that meet at the junction point.

6. DETAILED DESCRIPTION

(16) The present disclosure relates to a C-shaped tool holder 1 as shown in FIG. 1 in a schematic side view according to an embodiment. C-shaped tool holders 1 are generally known in view of their use, for example in rivet setting devices or clinching tools. They consist of one first 3 and one second leg 5 (see the dashed-dotted line in FIG. 1) which run horizontally in FIG. 1 and are connected to each other by a connecting leg 7 (dashed line in FIG. 1).

(17) The first 3 and the second leg 5 as well as the connecting leg 7 consist of an integral frame structure 10. Within this frame structure 10, they are integral with each other and do not exist as connected or connectable leg modules. In this context, integral means that the frame structure 10 forms a contiguous whole that is not able to be dismantled into its individual parts without destroying it. Correspondingly, the legs 3, 5, 7 are not connected to each other by force-fitting, frictional or surface-bonded connecting elements.

(18) The integral frame structure 10 of the tool holder 1 is formed by a plurality of bar elements 14 that are connected to each other via intersections 12. A plurality of bar elements 14 each encloses a free space 16 and thereby forms frame triangles 20, frame quadrilaterals 22, frame pentagons 24 as well as multiple-vertex frame bodies with more than five corners (not shown). These are summarized as multiple-vertex frame bodies and have any number of, but at least 3, corners.

(19) To optimally control the deformation behavior of the tool holder 1, the integral frame structure 10 is composed of a combination of adjacent multiple-vertex frame bodies 20, 22, 24. This results in a framework. The multiple-vertex frame bodies may have 3, 4 or 5 corner points. In the first 3 and second leg 5, which are also referred to as arms, preferably frame quadrilaterals or frame pentagons alone or in conjunction with other multiple-vertex frame bodies are employed to control the bending-up behavior of the tool holder 1. In the connecting leg 7, a central frame quadrilateral 22 may be used. This is combined according to different embodiments with frame triangles 20 arranged opposite each other, such as two or four (see FIG. 1).

(20) In this design of the tool holder 1, its practical use results in considerable mechanical stress loads in the bordering bar elements 14 of the frame structure 10. To counteract this, in the prior art bar cross-sections of the bar elements 18 are correspondingly enlarged. This occurs either by individually widening a used bar or overall by increasing the thickness of a plate from which a C-frame is manufactured.

(21) FIG. 2 shows a sectional enlargement from the frame structure 10. The bar elements 14 may be connected to each other at the intersections 12 by continuously curving connecting surfaces 30 (see continuous line in FIG. 2). The connecting surfaces 30 may be determined with the assistance of periodic, continuously curving 4.sup.th order NURBS curves with variable curvature. Based on this shaping of the transition areas between bar elements 14 at intersections 12, mechanical stresses that appear near the intersections 12 are optimally distributed across the area of the intersection 12. Moreover, in this manner disadvantageous mechanical stress peaks in this area are reduced or avoided.

(22) It is also conceivable to connect adjacent bar elements 14 to each other in intersections 12 via roundings of bordering bar element edges (see dotted line in FIG. 2). A rounding is a curve segment with constant curvature that transitions to the straight bar element edges tangentially continuously. Thereby, areas of non-optimal mechanical stress distribution occur in transition areas between the curve segment and straight bar element edges. In this context, FIG. 14 shows a comparison of mechanical stresses that occur at an intersection 12 with tangentially continuous transition areas between bar elements 14 (see FIG. 14b) and the same intersection 12 with continuously curving transition areas (see FIG. 14a). The mechanical stress values show that the intersection 12 with tangentially continuous transition areas between the bar elements 14 is subjected to stronger mechanical loads than the intersection 12 with continuously curving transition areas.

(23) FIG. 3 once again shows the sectional enlargement from FIG. 2 but only with continuously curving connections between adjacent bar elements 14 in the area of intersections 12 (represented here with a dotted line).

(24) To design the tool holder 1, the connecting leg 7 is made from at least two frame triangles 20 and one multiple-vertex frame body 22; 24 and its first 3 and its second leg 5 are each made from at least one multiple-vertex frame body 22; 24. It may also be preferable to make the connecting leg 7 from at least four frame triangles 20 and one frame quadrilateral 22, and to make the first 3 and the second leg 5 each from at least one frame quadrilateral 22 or one frame pentagon 24.

(25) For a simplified representation of the make-up of the tool holder 1, this is considered in the drawing plane of the accompanying drawings. Correspondingly, the surface of the free space 16 that is enclosed in a multiple-vertex frame body 20, 22, 24 lies in the drawing plane. The bar elements 14 have a width and a depth. The width lies in the drawing plane and the depth extends vertically into or out of the drawing plane. Correspondingly, the free space 16 in a multiple-vertex frame body 20, 22, 24 may be surrounded by a depth surface, curving along a circumferential direction, that is arranged vertically to the drawing plane.

(26) Under the assumption that the tool holder 1 has a constant depth vertical to the drawing plane, the legs 3, 5, 7 are made from a plurality of multiple-vertex frame bodies 20, 22, 24. These multiple-vertex frame bodies 20, 22, 24 form the outer C-shaped edge R.sub.a and the inner C-shaped edge R.sub.i. The outer R.sub.a and the inner edge R.sub.i are formed by bar elements 14 of the multiple-vertex frame bodies 20, 22, 24 of the integral frame structure 10. Moreover, they are supported and connected to each other by the bar elements 14 within the integral frame structure 10. The inner R.sub.i and the outer edge R.sub.a may be delimited to the outside by continuously curving lateral surfaces that are arranged parallel to the depth direction.

(27) It is also conceivable here to use tangentially continuous lateral surfaces.

(28) To make the tool holder 1, the multiple-vertex frame bodies 20, 22, 24 are initially defined by frame polygons 30, 32, 34. The frame polygons 30, 32, 34 have, depending on the embodiment, three corners and three sides (see reference sign 30), four corners and four sides (see reference sign 32), five corners and five sides (see reference sign 34) or more. The corner points of the frame polygons are connected to each other at the intersections 12. The make-up described above of the legs 3, 5, 7 from the frame polygons 30, 32, 34 is illustrated in FIG. 5.

(29) To optimally control the deformation behavior, the basic structure of the C-frame is composed of a combination of adjacent polygons. This results in a framework. The polygons have either 3, 4 or 5 corner points. In the arms of the C-frame, quadrilaterals or pentagons may be employed to control the bending-up behavior. In the middle area of the C-frame, a central frame quadrilateral is used.

(30) With this design of the tool holder 1, the disclosure orients itself towards the example of nature, where loaded areas in junction points of trusses (e.g., forked branches) are configured like a continuously curving curve with variable curvature. Therefore, the transition areas between two adjacent bar elements 14 may be configured with periodic, continuously curving 4.sup.th order NURBS curves with variable curvature that optimally distribute the stress progression of the bar elements 14 near the intersection 12 over the area of the bifurcation and avoid stress peaks in the transition area.

(31) To further design the tool holder 1, reference is made to the quadrilateral frame polygon 32 according to FIG. 6a. This serves as an example for the further configuration of the frame polygons 30, 32, 34 in the integral frame structure 10.

(32) The frame polygons 30, 32, 34 of a basic structure according to FIG. 5 are set by offset calculations of the individual edges corresponding to a target strength of the later bar elements 14. This results in the offset polygons 40 that specify approximately the material contour of the later bar elements 40 of the integral frame structure (see FIG. 6b).

(33) The junction points 42 on the middle of the edge and on the corner points of the offset polygons 40 are generated on the offset polygons 40. These serve as junction points 42 for the NURBS curves 50. On the basis of the junction points 42, periodic 4.sup.th order NURBS curves are generated that are represented by the reference sign 50 and meet the requirements for the curve continuity. Frame structures 10 optimized in this manner have, in addition to a reduction of the load from mechanical stress, additional weight advantages compared to the prior art since the employed material is distributed optimally. With reference to FIG. 6d, FIG. 7 shows an enlarged representation of the calculation of the integral frame structure 10.

(34) The aforementioned NURBS curve C(u) is generally known and defined by the degree k, for example 3.sup.rd degree, of its basis polynomials (=order p of the NURBS curve1), an amount P of weighted (w.sub.i) control points P.sub.i and a joint vector U. NURBS curves and surfaces are generalizations of B-splines as well as Bzier curves and surfaces. The main difference from these two spline types is the weighting of the control points with the weights w.sub.i. With the w.sub.i NURBS curves become rational.

(35) The NURBS curve is fully defined by the sum of the control points P.sub.i weighted with rational B-spline base functions R.sub.i,k, by the formula

(36) $C\left(u\right)=\underset{i=0}{\overset{n}{.Math.}}{R}_{i,k}\left(u\right)P_i$

(37) The rational B-spline base function is calculated from B-spline base functions N.sub.i,k of the degree of the basis polynomial k, such as 3, and the weights w.sub.i associated with control points as

(38) $R_{i,k}\left(u\right)P_i=\frac{N_{i,k}\left(u\right)w_i}{\underset{j=0}{\overset{n}{.Math.}}{N}_{j,k}\left(u\right)w_j}$

(39) The parameter u[a, b] activates the individual segments of the spline curves in the area of the joint vector

(40) $V_K=\left\{\underset{\underset{p}{}}{a_{\left(0\right)},\mathrm{.Math.},a_{\left(p-1\right)}},u_p,\mathrm{.Math.},u_n,\underset{\underset{p}{}}{b_{\left(n+1\right)},\mathrm{.Math.},b_{\left(n+p\right)}}\right\}$

(41) The elements of the joint vector V.sub.K are monotonically increasing, wherein all a.sub.(i)=a.sub.(j) as well as all b.sub.(i)=b.sub.(j).

(42) Similar calculations can be performed for NURBS surfaces according to the following formulas:

(43) $S\left(u,v\right)=\underset{i=0}{\overset{n}{.Math.}}\underset{j=o}{\overset{n}{.Math.}}{R}_{i,j}\left(u,v\right)P_{i,j}$$R_{i,j}\left(u,v\right)=\frac{N_{i,p}\left(u\right)N_{j,q}\left(v\right)w_{i,j}}{\underset{k=0}{\overset{n}{.Math.}}\underset{l=0}{\overset{m}{.Math.}}{N}_{k,p}\left(u\right)N_{l,q}\left(v\right)w_{k,l}}$

(44) The design method described above may be computer-based, meaning performed with the assistance of an appropriate software program. Such software programs are generally known as CAD programs and are a usual tool in design technology. Such software programs and the computer-based systems that implement them may realize all the computer-based activities in a design process. These include geometric modeling, the calculating described above, simulating the integral tool holder 1. Moreover, a design data set may be created and given over to the production or respectively manufacturing. These are, for example, CNC machines that implement the computer-based data set into a product. In a similar manner, the result of the design method can also be implemented into a manufacturing drawing. Accordingly, the present invention also comprises the production of the tool holder 1 based on the computer-based, implemented design method above.

(45) FIG. 8 shows a frame polygon 30 with three corners. To obtain a frame triangle 20, the frame polygon 30 was surrounded with the offset contour 40 (see above). When this frame triangle 20 is loaded by a force F according to FIG. 9, an angular bending-up is thereby generated in the loaded corner area. This is indicated by the arrow in FIG. 9.

(46) A similar consideration of a frame quadrilateral 22 (see FIG. 10) or a frame pentagon leads to a parallel bending-up in the event of a mechanical load of a corner area. This is illustrated in FIGS. 11 and 12 by a mechanical load with the force F. This load F acts on the lower left corner of the frame quadrilateral 22 in FIG. 11 and of the frame pentagon 24 in FIG. 12.

(47) It follows from this consideration that, based on the appropriate choice of a frame quadrilateral 22 or a frame pentagon 24 instead of a frame triangle 20, the deformation of the integral frame structure 10 under load can be deliberately adjusted towards a parallel bending-up. Therefore, it may be preferred to employ frame quadrilaterals 22 in the arms of the C-shaped tool holder 1, meaning in the first 3 and in the second leg 5.

(48) This adjustment of the deliberate parallel bending-up of the tool holder 1 under mechanical load is illustrated in FIG. 13. Here the difference of the frame structure designed from frame polygons 30, 32, 34 in the non-loaded state from the parallel-deflected integral frame structure 10 demonstrates the deliberately influenced deformation of the tool holder 1 by the force F.

REFERENCE SIGN LIST

(49) 1 Tool holder 3, 5 First and second leg 7 Connecting leg 10 Integral frame structure 12 Intersection 14 Bar element 16 Free space 20 Frame triangle 22 Frame quadrilateral 24 Frame pentagon 30 Frame polygon with three corners 32 Frame polygon with four corners 34 Frame polygon with five corners 40 Offset polygon 42 Junction point 50 NURBS curve 60 Loaded frame structure L Length B Width T Depth of the bar element 12