Saw Tool

Abstract

The disclosure relates to a saw tool, in particular a saw blade, for a machine tool, in particular an oscillating multifunctional machine tool, comprising at least one iron-containing support and at least one tungsten-containing hard metal strip which has a strip connection edge, wherein the at least one hard metal strip is bonded to the support at the strip connection edge via a diffusion connection which has at least one diffusion zone. The strip connection edge is designed to be at least substantially curved, in particular along a circular arc.

Claims

1. A saw blade, for a multifunctional power tool configured to be driven in oscillation, comprising: at least one iron-containing carrier; and at least one tungsten-containing hard metal strip that has a strip connection edge, wherein the at least one tungsten-containing hard metal strip is connected to the at least one iron-containing carrier at the strip connection edge in a materially bonded manner via a diffusion joint that has at least one diffusion zone, and the strip connection edge is at least substantially curved along a circular arc.

2. The saw blade as claimed in claim 1, wherein the strip connection edge extends over a segment angle of at least 15°.

3. The saw tool as claimed in claim 1, wherein: the at least one diffusion zone has two end edges that are located at the end regions of the maximum extent of the strip connection edge; and the end edges are of at least substantially equal lengths.

4. The saw tool as claimed in claim 1, wherein the at least one tungsten-containing hard metal strip has, opposite the strip connection edge, at least one cutting edge on which cutting teeth are arranged and which extends over a circular segment having a segment angle of at least 15°.

5. The saw tool as claimed in claim 1, wherein the strip connection edge is at least substantially undulated.

6. The saw tool as claimed in claim 1, wherein: the at least one tungsten-containing hard metal strip has at least one cutting edge opposite the strip connection edge; the at least one cutting edge and the strip connection edge are on average at least substantially parallel to each other; and the strip connection edge has a lesser maximum extent than the at least one cutting edge.

7. The saw tool as claimed in claim 1, wherein: the at least one tungsten-containing hard metal strip has at least one cutting edge opposite the strip connection edge; the at least one cutting edge has a continuous, curved shape that is at least substantially parallel to the strip connection edge; and the strip connection edge and the at least one cutting edge each extend over a circular segment having a segment angle of at least 15°.

8. The saw tool as claimed in claim 1, wherein: the at least one iron-containing carrier has at least one carrier connection edge by which the at least one iron-containing carrier is connected to the at least one tungsten-containing hard metal strip; and the at least one iron-containing carrier connection edge has a continuous, curved shape that extends over a circular segment having a segment angle of at least 15°.

9. A power tool system comprising: at least one multifunctional power tool that can be driven in oscillation; at least one saw blade as claimed in claim 1.

10. A method for producing a saw blade as claimed in claim 1, comprising: connecting the at least one tungsten-containing hard metal strip to the at least one iron-containing carrier.

11. The method as claimed in claim 10, further comprising: effecting a spatially inhomogeneous depletion of alloy particles in the at least one tungsten-containing hard metal strip to achieve the diffusion joint.

Description

DRAWING

[0034] Further advantages are given by the following description of the drawing. Two exemplary embodiments of the invention are represented in the drawing. The drawing, the description and the claims contain numerous features in combination. Persons skilled in the art will also expediently consider the features individually and combine them to create appropriate further combinations.

[0035] In the drawing:

[0036] FIG. 1 shows a power tool system according to the invention, comprising a power tool and a saw tool, in a schematic representation,

[0037] FIG. 2 shows the saw tool according to the invention, in a schematic representation,

[0038] FIG. 3 shows a method according to the invention for producing the saw tool according to the invention, in a schematic representation, and

[0039] FIG. 4 shows an alternative saw tool according to the invention, in a schematic representation.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0040] FIG. 1 shows a power tool system 46a comprising at least one power tool 44a and at least one saw tool 10a. The power tool 44a is in particular constituted by a multifunction power tool that can be driven in oscillation.

[0041] The power tool system 46a comprises at least one saw tool 10a. The saw tool 10a is in particular realized as a saw blade. The saw tool 10a is designed for the power tool 44a, in particular the multifunctional power tool that can be driven in oscillation.

[0042] FIG. 2 shows the saw tool with at least one iron-containing carrier 12a and at least one tungsten-containing hard metal strip 14a. The carrier 12a is produced, for example, at least partially, from a steel, a carbide, a ferrous alloy or a ferrous ceramic metal. The hard metal strip 14a is produced, for example, at least partially, from a carbide, a tungsten-containing and/or cobalt-containing ceramic metal, in particular ceramic hard metal, or the like. The carrier 12a has a machine interface 26a. The machine interface 26a is realized as a plurality of recesses 28a through the carrier 12a. The recesses 28a each form a through-hole through the carrier 12a, perpendicularly to the plane of main extent of the carrier 12a. The recesses 28a each have equally sized outer contours. The recesses 28a are arranged symmetrically around a central recess 30a. The central recess 30a has an at least substantially star-shaped outer contour. The at least one carrier 12a has at least one carrier connection edge 34a. The at least one carrier connection edge 34a has a continuous, curved shape. The carrier connection edge 34a extends over a circular segment having a segment angle 20a of at least 15°.

[0043] The hard metal strip 14a has a strip connection edge 16a. The strip connection edge 16a is realized at least substantially curved, in particular along a circular arc. The strip connection edge 16a extends over a segment angle 20a of at least 15°. FIG. 2 shows that the strip connection edge 16a is curved along a circular arc. It is conceivable for the strip connection edge 16a to be curved along an ellipse, a circle corresponding in particular to a special case of an ellipse. A mid-point 32a of the central recess 30a of the machine interface 26a realizes, for example, the mid-point 32a of the circle and/or of the ellipse, in particular around which the strip connection edge 16a, in particular the carrier connection edge 34a, is curved. In particular, the mid-point 32a of the central recess 30a realizes a point around which the recesses 28a are arranged with point symmetry. In particular, the mid-point 32a of the central recess 30a realizes a pointed end of the segment angle 20a over which the strip connection edge 16a, in particular the carrier connection edge 34a, extends. The mid-point 32a realizes in particular a drive center from where in particular the saw tool 10a can be driven by the power tool 44a. It is conceivable, in particular in the case of an asymmetrically realized machine interface 26a, for the mid-point 32a of the circle and/or of the ellipse to be realized at a distance from a mid-point of the machine interface 26a.

[0044] The at least one hard metal strip 14a has at least one cutting edge 24a. The cutting edge 24a is arranged opposite the at least one strip connection edge 16a. There are saw teeth 40a arranged on the cutting edge 24a. The cutting edge 24a extends over a circular segment having a segment angle 20a of at least 15°. The at least one cutting edge 24a has a continuous, curved shape that is at least substantially parallel to the at least one strip connection edge 16a. The at least one strip connection edge 16a and the at least one cutting edge 24a each extend over a circular segment having a segment angle 20a of at least 15°. FIG. 2 shows that the cutting edge 24a and the strip connection edge 16a are on average at least substantially parallel to each other. The strip connection edge 16a has a lesser maximum extent than the cutting edge 24a.

[0045] The hard metal strip 14a is connected to the carrier 12a in a materially bonded manner at the strip connection edge 16a via a diffusion joint. The at least one carrier 12a is connected, at the carrier connection edge 34a, to the at least one hard metal strip 14a, at the strip connection edge 16a, in particular in a materially bonded manner. The diffusion joint has a diffusion zone 18a. The diffusion zone 18a is arranged between the hard metal strip 14a, in particular the strip connection edge 16a, and the carrier 12a, in particular the carrier connection edge 34a. The diffusion zone 18a is realized as a material joining of alloy particles. The diffusion zone 18a is realized as a material union of the carrier 12a and of the hard metal strip 14a. The diffusion zone 18a is realized as a single piece, in particular as a single part, with the carrier 12a and the hard metal strip 14a. The diffusion zone 18a is realized from parts, in particular diffusion particles, of the hard metal strip 14a and of the carrier 12a, in particular by a partial particle erosion from an alloy region 36a of the hard metal strip 14a and a carrier alloy region 38a of the carrier 12a. The alloy region 36a is arranged, on the hard metal strip 14a, at an end that faces toward the strip connection edge 16a, along the maximum extent of the hard metal strip 14a. The carrier alloy region 38a is arranged, on the carrier 12a, at an end that faces toward the carrier connection edge 34a, along the maximum extent of the carrier connection edge 34a. The carrier alloy region 38a has a lesser extent perpendicularly to the maximum extent of the hard metal strip 14a and perpendicularly to the material thickness of the carrier 12a than has the alloy region 36a of the hard metal strip 14a.

[0046] The alloy region 36a of the hard metal strip 14a comprises a sub-region of the hard metal strip 14a that has at least 3% fewer alloy particles than the part of the hard metal strip 14a that adjoins the alloy region 36a. In the alloy region 36a, a depletion, in particular of at least 3%, of alloy particles, such as tungsten and/or cobalt, is realized in the at least one hard metal strip 14a. It is conceivable for the depletion of alloy particles in the alloy region 36a to be realized in the at least one hard metal strip 14a in a spatially inhomogeneous manner, in particular as a descending gradient, as a result of a supply of heat to the at least one hard metal strip 14a. It is conceivable for the depletion of alloy particles in the alloy region 36a to be realized as a descending gradient in the direction of a cutting region 42a of the hard metal strip 14a that is arranged in a vicinity of the cutting edge 24a. It is conceivable for the cutting region 42a to be realized without depletion of alloy particles, such as tungsten and/or cobalt.

[0047] The diffusion zone 18a has two end edges 22a, 22a′. The end edges 22a, 22a′ are located at the end regions of the maximum extent of the strip connection edge 16a. The end edges 22a, 22a′ are of at least substantially equal lengths. It is conceivable for the lengths of the end edges 22a, 22a′ to be realized selectively. It is conceivable that the lengths of the end edges 22a, 22a′ can be realized selectively, in particular by an input of heat that is focused in particular spatially, homogeneously and/or in particular spatially and/or temporally, for the purpose of achieving the diffusion joint of the hard metal strip 14a to the carrier 12a.

[0048] It is conceivable for the end edges 22a, 22a′ to be of different lengths, in particular depending on an accuracy of a heat input. It is conceivable for the end edges 22a, 22a′ to be realized, by very short temporally focused heat pulses in a soldering process and/or welding process, so as to be at least substantially of the same length. It is also conceivable for the end edges 22a, 22a′ to be realized, by spatially focused heat pulses, in particular by micro soldering tools and/or micro welding tools, in a soldering process and/or welding process, so as to be at least substantially of the same length. It is also conceivable for the end edges 22a, 22a′ to be realized, by spatially focused light pulses for input of heat, so as to be at least substantially of the same length. It is conceivable for the end edges 22a, 22a′ to be of at least substantially equal lengths that are realized by means of a temporally and/or spatially controlled supply of heat into the hard metal strip 14a and/or into the carrier 12a.

[0049] The diffusion zone 18a has two main end edges 56a, 56a′. The main end edges 56a, 56a′ are located along the maximum extent of the strip connection edge 16a. The main end edges 56a, 56a′ are of at least substantially equal lengths, in particular extents from the strip connection edge 16a to the carrier connection edge 34a. The length of the main end edge 56a, 56a′ is in particular the maximum extent of the main end edge 56a, 56a′ from the strip connection edge 16a to the carrier connection edge 34a. It is conceivable that the lengths, in particular extents from the strip connection edge 16a to the carrier connection edge 34a, of the main end edges 56a, 56a′ can be realized selectively. It is conceivable that the lengths of the main end edges 56a, 56a′ can be realized selectively, in particular by an input of heat that is focused in particular spatially, homogeneously and/or in particular spatially and/or temporally, for the purpose of achieving the diffusion joint of the hard metal strip 14a to the carrier 12a. It is conceivable that the main end edges 56a, 56a′ to be different lengths, in particular depending on an accuracy of a heat input.

[0050] It is conceivable that the main end edges 56a, 56a′ to be realized, by very short temporally focused heat pulses in a soldering process and/or welding process, so as to be at least substantially the same length. It is also conceivable for the main end edges 56a, 56a′ to be realized, by spatially focused heat pulses, in particular by micro soldering tools and/or micro welding tools, in a soldering process and/or welding process, so as to be at least substantially of the same length. It is also conceivable that the main end edges 56a, 56a′ to be realized, by spatially focused light pulses for input of heat, so as to be at least substantially of the same length. It is conceivable for the main end edges 56a, 56a′ to be of at least substantially equal lengths that are realized by means of a temporally and/or spatially controlled supply of heat into the hard metal strip 14a and/or into the carrier 12a.

[0051] It is conceivable for the hard metal strip 14a, at the cutting edge 24a, to be of a greater extent, in particular thickness, perpendicularly to the cutting edge 24a than at the strip connection edge 16a. It is also conceivable for the hard metal strip 14a, at the cutting edge 24a, to be of a lesser or equal extent, in particular thickness, at the cutting edge 24a perpendicularly to the cutting edge 24a than at the strip connection edge 16a.

[0052] It is conceivable for the hard metal strip 14a, at the cutting edge 24a, to have a stiffness that differs from a stiffness at the strip connection edge 16a, in particular in the alloy region 36a. It is conceivable for the hard metal strip 14a to be eroded, in particular depleted of alloy elements, at an end edge 22a, 22a′. It is conceivable for one end edge 22a, 22a′ is realized so as to be the same length, up to 0.5 cm, as the respectively other end edge 22a, 22a′. It is conceivable for a greater tungsten component to be diffused into the diffusion zone 18a from a sub-region of the alloy region 36a of the hard metal strip 14a at one, in particular longer, end edge 22a, 22a′ than from other sub-regions of the alloy region 36a. It is also conceivable for the hard metal strip 14a to be completely eroded, in particular angled, at an end edge 22a, 22a′ and to adjoin a longer end edge 22a, 22a′.

[0053] FIG. 3 shows a method for producing a saw tool 10a. In at least one method step, in particular a bending step 50a, the hard metal strip 14a is curved, in particular by a mechanical deformation process. Preferably, in at least one method step, in particular the one bending step 50a, the hard metal strip 14a is curved over its entire main extent along an ellipse, in particular along a circle, in particular over a segment angle 20a of at least 15°, preferably at least 20°, in particular at least 45°. FIG. 2 shows a segment angle 20a of about 100°. Preferably, in at least one method step, in particular the one bending step 50a, the at least one hard metal strip 14a is curved over its entire main extent in a single bending process. It is conceivable for heat to be input into the hard metal strip 14a, for the purpose of increasing flexibility, in at least one method step, in particular the at least one bending step 50a. It is conceivable for the hard metal strip 14a to be curved in sections in a temporally staggered manner, in particular until the hard metal strip 14a is curved over its entire main extent, in at least one method step, in particular the at least one bending step 50a.

[0054] In at least one method step, in particular a connection step 52a, the at least one hard metal strip 14a is connected to the at least one carrier 12a. In at least one method step, in particular the at least one connection step 52a, the at least one hard metal strip 14a is connected to the at least one carrier 12a by a joining process such as, for example, soldering and/or welding. In at least one method step, in particular the at least one connection step 52a, the input of heat is controlled for the purpose of precisely achieving the tungsten component, in particular in dependence on the distance in the diffusion zone 18a from the strip connection edge 16a, in particular with an accuracy deviation of at most 1%, in the diffusion zone 18a. In at least one method step, in particular the at least one bonding step 52a, the tungsten component, in particular in percentage by weight, in the diffusion zone 18a is selectively controlled, in particular in dependence on the distance in the diffusion zone 18a from the hard metal strip 14a, in particular with an accuracy tolerance of at most 0.02 mm. In at least one method step, in particular the at least one connection step 52a, the hardness, in particular measured in HV 0.5, in the diffusion zone 18a is selectively controlled, in particular in dependence on the distance in the diffusion zone 18a from the hard metal strip 14a, in particular with an accuracy tolerance of at most 0.02 mm. In at least one method step, in particular the one connection step 52a, a spatially inhomogeneous depletion of alloy particles is realized in the at least one hard metal strip 14a for the purpose of achieving the diffusion joint. In at least one method step, in particular the one connection step 52a, a cutting edge region that is arranged opposite the at least one strip connection edge 16a on the at least one hard metal strip 14a is realized at least substantially without depletion of alloy particles. It is conceivable for at least one hard metal strip 14a to be connected to the at least one carrier 12a by a welding process without any soldering element, such as a solder wire, preferably a solder wire having a tin component, in at least one method step, in particular the at least one connection step 52a.

[0055] In at least one method step, in particular a tooth step 54a, saw teeth 40a are made in the hard metal strip 14a by a forming process such as, for example, a turning process, drilling process, punching process, grinding process and/or milling process. In at least one method step, in particular the tooth step 54a, saw teeth 40a are made in the hard metal strip 14a at the cutting edge 24a of the hard metal strip 14a. In at least one method step, in particular the tooth step 54a, saw teeth 40a are at the cutting edge 24a over a segment angle 20a of at least 15°, preferably at least 45°. In at least one method step, in particular the tooth step 54a, at least five, in particular at least ten, preferably at least fourteen, particularly preferably at least twenty, saw teeth 40a are made in the hard metal strip 14a.

[0056] It is conceivable that in at least one method step, in particular the one connection step 52a, an input of heat is controlled to reduce the hardness, in particular measured in HV 0.5, in particular stiffness, of the hard metal strip 14a in a region of the hard metal strip 14a, in particular in order to ensure a tungsten component of from 6% to 25% in the diffusion zone 18a.

[0057] FIG. 4 shows a further exemplary embodiment of the invention. The following descriptions and the drawings are limited substantially to the differences between the exemplary embodiments and, in principle, reference may also be made to the drawings and/or the description of the other exemplary embodiment, in particular of FIGS. 1 and 2, in respect of components having the same designation, in particular in respect of components denoted by the same references. To distinguish the exemplary embodiments, the letter a has been appended to the references of the exemplary embodiment in FIGS. 1 and 2. In the exemplary embodiments of FIG. 3, the letter a is replaced by the letters b to f.

[0058] FIG. 3 shows a further exemplary embodiment of the saw tool 10b. FIG. 3 shows in particular that the strip connection edge 16b is at least substantially undulated. The carrier connection edge 34b is at least substantially realized in an undulating manner. The strip connection edge 16a and the carrier connection edge 34a each have a mean course, in particular a quadratic mean. The strip connection edge 16b and the carrier connection edge 34b are realized so as to fit each other precisely, in particular complementarily. In particular, the wave crests of the strip connection edge 16b and the wave troughs of the carrier connection edge 34b are arranged opposite each other. In particular, the wave troughs of the strip connection edge 16b and the wave crests of the carrier connection edge 34b are arranged opposite each other. FIG. 3 shows that the cutting edge 24b and the strip connection edge 16b are on average at least substantially parallel to each other. The mean courses, in particular the quadratic means, of the strip connection edge 16b and of the carrier connection edge 34b are at least substantially parallel to each other.