EP0854773A2

EP0854773A2 - Insertable tool and tool holder for drilling and/or impacting electric machines

Info

Publication number: EP0854773A2
Application number: EP96945347A
Authority: EP
Inventors: Siegfried Fehrle; Rolf Müller; Vinzenz HÄRLE; Sven Kageler
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1995-10-12
Filing date: 1996-10-01
Publication date: 1998-07-29
Anticipated expiration: 2016-10-01
Also published as: TW350801B; ATE236764T1; WO1997013602A2; JP2000501031A; BR9610916A; WO1997013602A3; DE59610334D1; CN1060713C; EP0854773B1; US5984596A; CN1199358A; RU2189305C2

Abstract

PCT No. PCT/DE96/01889 Sec. 371 Date Apr. 13, 1998 Sec. 102(e) Date Apr. 13, 1998 PCT Filed Oct. 1, 1996 PCT Pub. No. WO97/13602 PCT Pub. Date Apr. 17, 1997A combination of an insertable tool (2), e.g. a drill or chisel, for an electrical machine for drilling and/or impact operation and a tool holder (20) for the insertable tool is disclosed. The insertable tool includes a tool shaft (11) provided with a round core cross section (1) not weakened or reduced at any point along the tool shaft (11) up to an inserted tool shaft end. The tool shaft has longitudinal struts (6) for torque transmission and axial guidance extending beyond the round core cross section (1) and the longitudinal struts (6) are shaped to merge with the core cross section in front of a cylindrical end portion (3). The tool holder (20) has a receiving sleeve (21) including a front portion (21a) for sealing and guidance of the tool shaft (11) and another portion (21b) including radially inwardly protruding longitudinal cleats (25) engagable between the longitudinal struts (6) for rotary driving of the insertable tool (2), an impact bolt (24) arranged for impact on the tool shaft (11) of the insertable tool (2) and at least one locking body (23) arranged between two adjacent longitudinal cleats (25) so that the at least one locking body (23) is radially movable between a locking position locking the insertable tool (2) in the receiving sleeve (21) and another position in which the insertable tool is released from the receiving sleeve.

Description

Einsatzwerkzeuα and tool holder for electrical machines with drilling and / or Schllaαbetrieb

State of the art

The invention relates to an insert tool and a tool holder according to the preamble of claim 1.

From DE-43 17 273 AI solutions for improving the rotary driving of insert tools are already known, in which, in addition to the rotary driving grooves on the tool shaft, rotary driving bars are arranged on the circumference of the shaft. This will make the

Driving surface increased and thus wear reduced, but the core cross-section of the shaft is still weakened by the driving grooves and locking troughs, so that the shock wave introduced by the firing pin of the machine into the tool shaft is not optimally guided to the tool tip during impact operation. In addition, notch effects occur at the bottom of the rotary driving grooves, which can lead to breakage of the shank if the rotary tool is subjected to high torsional loads or if a chisel tool is jammed. Such solutions are therefore only sufficiently stable and wear-resistant for lighter machines and lighter application tools.

From CH-PS 429 630 is also a percussion drill head attached to the end of a drill pipe for large drilling equipment Insert tool known, the tool shaft is designed as a spline shaft, but a tendon-like recess weakening the core of the shaft is provided for receiving an locking body inserted on the drill head holder for axial locking. This solution also leads to weakening of the drill head and impairment of the shock waves during operation.

The aim of the present solution is to use the application tools and the for medium-heavy machines

To design tool holders with higher impact resistance and less wear.

Advantages of the invention

This is achieved with the features in the characterizing part of claim 1 for insert tools with the advantage that an almost constant system cross-section from the firing pin to the core cross-section of the insert shaft via the sealing and guiding area and the drill core, or a chisel diameter, enables the undisturbed and optimal course of the impact . The system cross-section is not reduced or weakened at any point. It is only expanded, if necessary by a racket collar in the device, by the webs of the insertion shaft, if necessary by the sealing and guide area and by a drill helix. The longitudinal webs take over the rotary driving, the anti-rotation device in the event of bumps or jammed tools, as well as the axial locking.

With this construction, the insert shaft of the insert tool can be realized with existing devices with a fixed firing pin diameter with significantly higher strength and appropriate wear behavior. A circular core cross-section of the insert tool in the area of its insert shaft ensures the best possible centering. This centering is a prerequisite for the purest possible axial movement - for example when chiseling - and for aligning the joint. The axial movement and impact alignment is in turn a prerequisite for optimal work progress and thus for the lowest impact losses and bends. Avoiding bending stress reduces the risk of breakage on the one hand and noise generation on the other.

The measures listed in the subclaims result in advantageous developments and improvements of the features specified in the main claim. A system cross-section that is as constant as possible is special in

Transition area from the firing pin to the insert tool is particularly advantageous for the undisturbed course of the shock waves. Therefore, at the end of the tool shank, a section with the pure core cross section of the tool shank is provided for an optimal introduction of the impact before the area with the longitudinal webs is connected for rotary driving. In addition to the initiation function for the shock wave, this rear section is also advantageous for taking over a shaft guide. In addition, this section can be of different lengths or can be omitted entirely, whereby it serves as coding for insert tools which are unsuitable for impact operation. The shortened or omitted section ensures that the firing pin of the machine no longer hits the shaft of the insert tool.

The joint runs as undisturbed as possible through soft transitions, eg radii or concave shapes between the core cross-section and the longitudinal webs or the sealing and guide area. The two functions of the axial locking and the rotary power transmission between the tool holder and the tool shank can be realized in a serial arrangement by only one locking element, ie that only a longitudinal web with a front end face may be required for this. This locking element can also be used several times on the circumference in order to be able to insert the insert tool in several predetermined positions in a tool holder with only one lockable locking body. The two functions are arranged axially one behind the other. The two functions of axial locking and rotary power transmission can also be arranged next to each other on the circumference of the shaft. In this case, in addition to a locking recess in a longitudinal web, or in addition to a shortened longitudinal web, adjacent longitudinal webs without locking recess are located on both sides. Both functions can thus be accommodated on a short axial section.

The combination of serial and parallel arrangement of the longitudinal webs and the locking elements enables a space-saving arrangement of the functions that makes optimal use of the insertion shaft. The shorter webs enable axial locking in the same axial section of the tool shank, while longer webs with a correspondingly larger flank surface are available directly adjacent for the rotational force transmission. Continuous longitudinal webs to the sealing and guiding area support the guidance of the application tool, the course of the impact as well as disproportionately the area inertia or

Moment of resistance and thus the security against breakage of the tool shank. If one selects the arrangement of the combination of locking and torque transmission on a relatively small circumferential section, this combination can be repeated over the entire circumference relatively often. This will a small angle of rotation is reached, which is the maximum necessary to find the correct positioning for inserting the tool shank in the tool holder. In order to optimize wear, it must be ensured that the width of the longitudinal webs is in relation to the one in between

Grooves, or spaces, should be divided approximately equally large. This means that insert tools and tool holders are evenly loaded and their wear is reduced.

In a tool holder with the characterizing features of claim 13, it is advantageous that the locking body is arranged between two longitudinal strips behind the front sealing and guiding section of the receiving sleeve, so that it does not engage in the core cross section of the shaft. It is also advantageous that the firing pin of the machine is guided optimally with respect to the shaft end of the insert tool in order to be able to direct the shock waves to the tool tip as undisturbed as possible. By receiving the firing pin and the shaft end in the rear section of the receiving hole of the tool holder, an insert system advantageously results for the insert tool and the tool holder, in which, according to claim 16, the firing pin of the tool holder, the shaft end, the core cross section of the insert tool and its drill core, or its chisel diameter, have an almost constant system cross section.

drawing

Embodiments of the invention are shown in the drawing and explained in more detail in the following description. FIG. 1 shows an insert tool with a continuous core cross section as the first embodiment, FIG. 2 shows a drilling tool as the second embodiment, FIG. 3 shows a chisel tool as the third embodiment, and FIG. 4 to 11 the shaft ends of insert tools as further embodiments. FIG. 12 shows a tool shank suitable for a tool holder according to FIG. 13.

Description of the embodiments

FIG. 1 shows in a first exemplary embodiment an impact drill as an insert tool 2 with a tool shank 11 as an insert shank in drilling machines or in particular rotary hammers. Are located on the tool shank 11

Longitudinal webs 6, which take over an axial guidance, the rotational power transmission and anti-rotation in case of bumping or canting as well as an axial locking. The rotation or anti-rotation is carried out via a tool holder (FIG. 13) of the machine and the strikes are carried out by a firing pin 24 which is moved back and forth in a driven spindle sleeve of the machine and is shown separately in FIG. 1. The tool shank 11 has a non-weakened core cross section 1, which preferably extends to the end of the shank, with preferably 10 mm

Diameter. This core cross-section, together with approximately the same cross-section of the firing pin 24 in the device, a sealing and guiding area 4 and the drill core 5, forms an approximately constant system cross-section. Four longitudinal webs 6 are evenly distributed on the core cross section 1. The web outer contour 7 preferably has a diameter of 14 mm, which is designed as a circular element. The web flanks 12 are inclined to one another, so that the longitudinal webs 6 become wider towards the foot, which enables easy demolding in the case of non-cutting production. The shape of the flanks 12 and the web end faces 8 is curved, for example concave, so that a smooth transition from the core cross section 1 to the expansion by the longitudinal webs 6 is achieved. The transition of the web flanks 12 and the web end faces to the outer contour can be rounded or be sharp-edged. The shape of a web flank across the intermediate space 15 to the next web flank is circular or concave, the web flanks 12 of the adjacent longitudinal webs 6 being connected to one another via a concave region 14 reaching as far as the core cross section 1. The insert tool 2 has a sealing and guiding area 4 towards the working area. For an optimal impact course, this area 4 has the same diameter as the core cross section 1. The longitudinal webs 6 extend in the axial direction of the tool shank. They have a sloping, rounded rear end face 8b towards the shaft end and also a front, concave front end face 8a towards the tool tip. These end faces 8a serve for the axial locking of the tool shaft 11 for the engagement of a locking body which can be locked in the tool holder according to FIG. 13 of a machine.

For the axial movement of the tool shank 11 permitted by the locking body, an area 13 is provided on which the sealing and

Guide section 4 connects, both sections 4 and 13 having the core cross section 1 in the present embodiment. Since the longitudinal webs merge into the core cross section 1 in front of the shaft end, the shaft end forms a cylindrical section 3 with the

Core cross section 1 of the tool shank 11. Because four identical longitudinal webs 6 evenly distributed on the circumference have a front concavely inclined end face 8a, the tool shank 11 can be inserted and locked in four positions with a 90 ° offset in a tool holder of the machine.

FIG. 2 shows a further exemplary embodiment of an impact drill, the diameter of the sealing and guide section 4 being greater than that of the cross section 1 is, as large as the outer diameter of the longitudinal webs 6. To form the front concave end face 8a on two opposite longitudinal webs 6, these are provided with a longitudinal recess 13 extending to the core cross section 1, in which a locking body in

Tool holder of the machine can intervene axially. For this purpose, two further longitudinal webs 6 are arranged offset by 90 °. These do not have any longitudinal recesses for axial locking, but they run out into the guide section 4 of the tool shank 11. In this solution, the adjacent longitudinal webs 6 are unequal in width and the adjacent intermediate spaces 15, which are designed as longitudinal grooves between the longitudinal webs 6, have a different offset. Thus, the angle α between the two narrower longitudinal webs 6 and the center of the adjacent intermediate spaces 15 is not 45 ° as in the case of a uniform division, but the angle α is 50 ° here. Since in this case not all longitudinal webs have a locking function, the different offset of the space between the longitudinal webs prevents incorrect locking such that an uninterrupted longitudinal web 6 comes to rest in a longitudinal groove with a locking body according to FIG. 13 in the tool holder.

FIG. 3 shows a chisel as an insert tool, in which the longitudinal webs 6 and the shaft end 3 are designed in the same way as on the tool shaft according to FIG. 1. Here, however, the sealing and guiding area 4 of the tool shaft 11 is larger than the core cross section 1 and between this area 4 and the longitudinal webs 6 a section 13 reduced to the core cross section 1 is provided over the entire circumference of the tool shaft for the engagement of a locking body. FIG. 4 shows, as a further exemplary embodiment, a tool shank 11 of an insert tool with a design of the longitudinal webs 6 according to FIG. 2, with the difference that here only the upper longitudinal web 6 has a longitudinal recess 13 for the engagement of a

Has locking body. This shaft can therefore only be used in one position in a tool holder with a locking body according to FIG. 13.

Figure 5 shows a further embodiment of a

Tool shaft similar to that in FIG. 1, with the difference that two of the four longitudinal webs 6 of the same width are longer here and only run into the core cross section 1 at the sealing and guide area 4. This shaft can therefore only be inserted into a tool holder in positions that are offset by 180 °.

FIG. 6 shows, as a further exemplary embodiment, a tool shank with only two longitudinal webs 6, which are arranged at 180 ° to one another on the core cross section 1 of the tool shank.

Figure 7 shows in a further embodiment a tool shank similar to that in Figure 2, but with the difference that here the longitudinal recesses 13 for the axial locking are made in the middle of the two opposing wider longitudinal webs 6.

Figure 8 shows, based on Figure 3, a tool shank, in which the rear ends of the longitudinal webs 6 are each wedge-shaped to facilitate insertion into the corresponding tool holder. In addition, the sealing and guide area 4 is larger in diameter here than that of the core cross section 1, but not as large as the outer diameter of the longitudinal webs 6. FIG. 9 shows a tool shank 11 in which two identical, opposing longitudinal webs 6, each with a longitudinal recess 13 for axial locking, are provided on the core cross section 1. In addition, two mutually opposite pairs 6a of longitudinal webs 6 are arranged on the core cross section 1, the pairs 6a being separated from one another by a trapezoidal longitudinal groove 16. As in FIG. 8, the sealing and guiding region 4 also has a diameter here, which is between the

Core cross-section diameter and the outer diameter of the longitudinal webs 6.

In the embodiment according to FIG. 10, only the rear section 3 at the end of the tool shaft 11 forms the core cross section 1, whereas the sealing and guiding area and the areas of the tool shaft between the longitudinal webs 6 have a larger diameter. The insertion tool can be guided in the tool holder of a device here over the entire axial length of the tool shaft. In the case of a shape-bound (chipless) production of this tool shank, the raw material diameter is retained up to the rear end section 3 for guidance. The longitudinal webs 6 are formed by pressing the longitudinal troughs 15a down to the diameter of the core cross section 1 on both sides of the trough 15a by material displacement. The area 4 for sealing and guiding the tool shank is not changed in its geometry by the manufacturing process and thus grants the relevant initial tolerance. Only the central area of the tool shank with the longitudinal webs 6 for the rotary power transmission and locking is changed. A shape-related production is also possible with the tool shanks of FIGS. 8 and 9, since the webs are designed in such a way that they can be removed from a pressing tool, because their flanks have draft angles and because their ends have no undercuts. The longitudinal webs are designed there in such a way that the tool shank can be machined according to its division during shaping processing relative to the pressing tool, i.e. a tool shape can be found several times on the circumference of the tool shank in accordance with the division frequency, namely four times in FIG. 8 and in FIG 9 and 10 once on each half of the shaft. Overflows or demoulding edges do not lie on the tool shank in the functional areas for the axial guidance and the rotary power transmission and locking, but in the spaces 15 in between. The spaces between the longitudinal webs 6 lie inside and the longitudinal webs 6 produced by material displacement outside the raw material diameter, which remains unchanged in the sealing and guide area 4. In a machining, shapeless production of the tool shanks according to FIGS. 1 to 7, starting from the raw material diameter, all spaces 15 between the longitudinal webs 6 and the locking area 13 can be produced with a profile milling tool.

In the embodiment according to FIG. 11, in a modification of the embodiment according to FIG. 7, the cross sections of the longitudinal webs 6 are no longer symmetrical but have an asymmetrical profile. The rotary driving flank 12a of the

Longitudinal webs 6 here run approximately radially, whereas the rear flank 12b, which is not loaded by the rotary drive, runs like a chord. As a result, the spaces 15 between the longitudinal webs 6 are wedge-shaped, the radially extending flank 12a being the rotational driving moment can optimally accommodate and the approximately right-angled rear flank 12b of the adjacent longitudinal web has a considerably larger area in order, if necessary, to be able to better absorb bumps when tilting a chisel tool. The transition between the two flanks can be sharp or rounded. The asymmetrical flank shape supports the function of the torque transmission by allowing a wedge-shaped cross section for the longitudinal strips located in the tool holder, which engage in the spaces 15 of the longitudinal webs 6 of the tool shank 11. This also prevents canting when the tool is loaded due to the torque transmission in addition to the impact. An asymmetrical flank shape also enables rational production of the tool shank in which the wedge-shaped

Gaps 15 allow the use of cylindrical cutters with standard square indexable inserts. The asymmetrical longitudinal webs 6 are designed and optimized for clockwise rotation of the machine. The reverse direction of rotation may only be necessary when removing the insert tool from a borehole.

In the exemplary embodiment according to FIG. 12, a tool shank 11 for receiving in a tool holder 20 according to FIG. 13 is shown. The tool shank of the

With regard to the design of the longitudinal webs 6, the insert tool 3 corresponds to the embodiment according to FIG. 9, but with the difference that here the sealing and guiding region 4 has a diameter which is equal to the outer diameter of the longitudinal webs 6.

The longitudinal and cross-section shown in FIG. 13 through a tool holder 20 for receiving a tool shank according to FIG. 12 has a tubular tool holder with a receiving sleeve 21, the bore diameter of which in the front area corresponds to the diameter of the sealing and guide area 4 of the tool shank 11. In the central area of the tool holder, this has a corresponding plug-in profile which can be seen in FIG. 13b, corresponding to the profile of the tool shaft 11 in the area of the longitudinal webs 6. There, the inside diameter of the receiving sleeve 21 is reduced by the height of longitudinal strips 25 which protrude inward for torque transmission into the longitudinal grooves 16 and into the spaces 15 between the web flanks of the longitudinal webs 6 on the tool shank. The clear dimension between these longitudinal strips 25 results in the inner diameter 22, which corresponds approximately to the core diameter of the tool shank 11. The longitudinal strips 25 are necessary to fulfill the function of the torque transmission and also serve for axial guidance. The length of the longitudinal strips 25 is large in order to provide sufficient space for the torque transmission. The longitudinal strips 25 extend forward up to and including in the area of the locking. In order to axially lock the insert tool, a locking body, for example a ball 23, is inserted into an opening of the receiving sleeve in the front area between two longitudinal strips 25, which can escape radially outwards when the tool shaft is inserted and can then be locked by spring force. To remove the tool shank, however, the locking body must be released manually. This is done by pulling back an actuating sleeve 26 with a ring 27 against the force of a spring 28 which presses the ball 23 into the locking position. Between the longitudinal strips 25 in the tool holder there are grooves which end in the rear section of the tool holder at the beginning of a guide area for the firing pin 24. The rear section 3 of a tool shank 11 inserted in the tool holder 20 is also guided in this area. This area has approximately the diameter of the Core cross section, which in turn corresponds to the diameter of the firing pin 24. However, the insert tool is mainly guided in the front region of the receiving sleeve 21. A sealing lip 29 is also attached to the tool holder 20 there for sealing against dirt and the like.

The tool holder 20 is removably attached to a drive spindle 33 of the machine. By pulling a mounting sleeve 30 balls 32 when pulling the

Tool holder 20 escape to the outside behind a locking ring 31 and thus release the tool holder. An automatic locking takes place when the tool holder is pushed onto the drive spindle 33. Since the tool holder 20 and then the locking ring 31 of the locking balls 32 first reach the latter during insertion, the balls move outward into the unlocking position. In this position, when the tool holder 20 is pushed open, they push the locking ring 31 back until they are in the calottes provided on the outer circumference of the

Turn the tool holder inwards again and come to rest there. The locking ring 21 then moves by spring force over the locking balls 32 and thus secures the seat of the tool holder on the drive spindle. The actuating sleeve 26 and the mounting sleeve 30 can rotate freely, so that they stop during operation in the event of edge contact despite the rotating tool holder. This means greater safety for the operator since the machine does not absorb any kickback torque.

In the case of a tool shank according to FIG. 12 inserted into the tool holder according to FIG. 13, an insertion system according to the invention results, the firing pin 24 in the tool holder 20, the shank end 3, the core cross section 1 and the drill core 5 or the Chisel diameter of the insert tool 2 have an almost constant system cross section.

However, the invention is not limited to the exemplary embodiments shown, since constructive

Deviations from this do not affect the inventive concept of a plug-in system for plug-in tools as set out in claim 15. For example, the web flanks on the tool shank can also be designed radially or asymmetrically to one another. The longitudinal webs can represent, for example, a wedge, a quarter circle or a semi-circle. The longitudinal webs can also extend obliquely to the axis. Several webs can also be arranged one behind the other or offset from one another in the axial direction. The longitudinal recesses on the longitudinal webs for axial locking do not have to be made up to the core cross section. The sealing and guiding area can also have a larger diameter than the outer contour of the longitudinal webs. A coding of insert tools can be carried out by different lengths of the rear shaft end 3. The shoulders of the sealing and guide area and the longitudinal webs to the core cross section can be tapered or concave. The longitudinal webs can in turn be provided with longitudinal grooves or the spaces between the longitudinal webs can be provided with further webs. If the firing pin diameter of the machine is smaller than that of the core cross-section on the tool shaft, a conical phase must be attached to the shaft end in such a way that the end cross-section of the tool shaft is equal to that of the firing pin. If the longitudinal webs 6 are sufficiently wide, it may be expedient that the longitudinal recesses 13 for axial locking do not extend over the entire width of the longitudinal webs but only over part of the width. It can thereby be achieved that at least the torque-transmitting Flank of the longitudinal webs is also retained in the area of the longitudinal recess.

Claims

Expectations

1. insert tool (2) for electrical machines, in particular hand-held machine tools with drilling and / or hammering operation, with a tool shank (11) which can be inserted into a respective tool holder (20) of the machine and which has means (6, 8) for rotational driving and for axial locking, characterized in that the tool shank (11) has a non-weakened round core cross-section (1) reaching to its end face, on the circumference of which a plurality of longitudinal webs (6) are arranged, which are used for the axial guidance, the power transmission for the rotational driving or for preventing rotation and of which at least one of the longitudinal webs (6) has a shoulder (8b) for axial locking.

2. Insert tool according to claim 1, characterized in that the rear end face (8b) of the longitudinal webs (6) is inclined, in particular concavely towards the shaft end, and in that the at least one longitudinal web (6) has a front, inclined, in particular concavely inclined end face ( 8a) for axial locking, which has a distance (13) from a round sealing and guiding section (4) of the tool shaft (11) for the engagement of a locking body (23) which can be locked in the tool holder (20) of the machine.

3. Insert tool according to claim 1 or 2, characterized in that the core cross section (1) at least equal to the cross section of the tool core (5) Drilling tool or a chisel shank and the cross section of the guide section (4) is at least as large as the core cross section (1).

4. Insert tool according to one of the preceding claims, characterized in that the longitudinal webs (6) in front of a cylindrical portion forming the shaft end (3) pass into the core cross section (1).

5. Insert tool according to one of the preceding claims, characterized in that a plurality of identical longitudinal webs (6) evenly distributed on the circumference have a front oblique, in particular concave inclined end face (8a) such that the tool shaft (11) in several positions with the same circumferential division the tool holder (20) of a machine can be used.

6. Insert tool according to one of the preceding claims, characterized in that the diameter of the guide section (4) is larger than that of the core cross section (1) and that at least some of the longitudinal webs (6) run out into the guide section (4).

7. Insert tool according to one of the preceding claims, characterized in that to form the front, in particular concave end face (8a) at least one of the longitudinal webs (6) preferably has a longitudinal recess (13) reaching up to the core cross section (1), such that a locking body (23) is able to intervene in the tool holder (20) of the machine, so that the tool shaft (11) can be axially displaceably received in the tool holder (20).

8. Insert tool according to one of the preceding claims, characterized in that the web flanks 12 of the Adjacent longitudinal webs (6) are connected to one another via a concave region (14) reaching as far as the core cross section (1).

9. Insert tool according to one of the preceding claims, characterized in that the two axially parallel web flanks of the longitudinal webs (6) are each inclined so that the longitudinal webs (6) are wider towards their feet.

10. Insert tool according to one of the preceding claims, characterized in that adjacent longitudinal webs (6) are not the same width and / or that the adjacent spaces (16) between the longitudinal webs (6) have a different offset ().

11. Insert tool according to one of the preceding claims, characterized in that on the core cross-section (1) of the tool shank (11) two identical, opposite longitudinal strips (6) each with one

Longitudinal recess (13) for the axial locking and two mutually opposite pairs (6a) of longitudinal webs (6) are arranged offset from each other, the pairs (6a) being separated from one another by a preferably trapezoidal longitudinal groove (16).

12. Insert tool according to one of claims 1 to 7, characterized in that the rotary driving flank (12a) of the longitudinal webs (6) runs approximately radially and the flank (12b) which is unloaded by the rotary driving approximately runs like a chord.

13. Tool holder (20) of an electrical machine, in particular a handheld power tool with drilling and / or striking operation, with a receiving sleeve (21) and a firing pin (24) for a tool shaft (11) Insert tool (2) according to Claim 1, characterized in that the front section (21a) of the receiving sleeve (21) for sealing and guiding is smooth, that the section (21b) behind it has a plurality of radially inwardly projecting longitudinal strips (25) for rotary driving of the tool and that at least one locking body (23) which can be unlocked radially outwards is arranged between two adjacent longitudinal strips (25).

14. Tool holder according to claim 13, characterized in that the longitudinal strips (25) having the section (21b) forms a central section of the receiving sleeve (21) and that the rear section (21c) of the receiving sleeve (21) for receiving and guiding the firing pin (24) is smooth and has approximately the diameter of the core cross section (1) of the insert tool (2).

15. Tool holder according to claim (13), characterized in that the diameter of the front portion (21b) of the receiving sleeve (21) is at least as large as that

Outside diameter of the longitudinal webs (6) of the insert tool (2) and that the shaft end (5) of the insert tool (2) is received and guided in the rear section (21c) of the receiving sleeve (21).

16. Inserting system for inserting tools according to claim 1, in a tool holder (20) of electrical machines, in particular hand-held machine tools with drilling and / or striking operation according to claim 13, characterized in that firing pin (24), shaft end (3), core cross section (1) and preferably drill core (5) or chisel diameter and the sealing and guiding area (4) of the insert tool (2) have an almost constant system cross section.