EP2627481A1 - Torque transmission device, in particular in the form of a chuck for a bit - Google Patents

Abstract

The invention relates to a torque transmission device, comprising a sleeve part (1), which on the output side (11) thereof has an insertion opening (4) for a screwdriver insert (3), the opening having a non-round, in particular polygonal, cross-section, and on the drive side (12) has a drive shaft (2) that is inserted with an immobilization section (16), a stop section (20', 20") and an interposed torsion section (18), which twists when a torque is applied, in a drive cavity (6, 8, 9) of the sleeve part (1), wherein the drive shaft (2) is connected to the sleeve part (1) by means of the immobilization section (16) in a rotationally and axially fixed manner and can undergo torsion together with twisting of the torsion section (18), wherein the torsional ability of the stop section (20', 20") is limited by the stop in the screw tightening direction and in the screw loosening direction. So as to allow better use of the torque transmission device with a rotary impact screwdriver, the torsional angle of the stop section (20, 20") in the screw tightening direction is greater than in the screw loosening direction.

Description

 Torque transmission device, in particular in the form of a chuck for bits

The invention relates to a torque transmission device having a sleeve part which has on an output side a polygonal cross-section insertion opening for a screwdriver bit and on its drive side with a Tess, an abutment portion and an intermediate, twisting in a torque torsion portion in a drive cavity of the sleeve part ck- ckenden Drive shaft, wherein the drive shaft by means of the captive portion rotatably and axially fixed to the sleeve part and the stopper portion has a polygonal outer cross-section, which rests in such a cross-sectional larger polygonal internal cross-section profile of the drive cavity, that the torsion is limited by a predetermined rotation angle limited stop.

From EP 0 988 134 Bl a chuck for bits or the like is known. The chuck has a multi-part sleeve part, which has on a driven side a hexagonal cross-section having insertion into which a Außensechskantabschnitt a screwdriver bit can be inserted so that the Kreuzschlitzarbeitsspitze the screwdriver bit protrudes beyond the output side of the sleeve part. In a section of the cavity of the sleeve part which adjoins the insertion opening, a hexagonal-shaped bondage section of a drive shaft is inserted. The drive shaft has a connecting portion having a ring throat, with which the drive shaft can be inserted into a chuck of an electric screwdriver. This polygonal section forms a stop section. Between stop section and bondage section is located a completely lying in the drive cavity of the sleeve part torsion. The angle of rotation to the the torsion section can be rotated is stop limited. To limit the stop there are two sleeve parts provided.

DE 10 2008 005 831 AI describes an impact wrench in which a torque load of the output shaft charges an energy storage. The energy store is a compression spring which is tensioned as a result of a torque load and a relative rotation. The energy storage can be charged with energy. It discharges abruptly, whereby a flywheel is accelerated, which strikes in the direction of rotation against an anvil formed by the drive shaft. The stored energy in the energy storage is thus introduced in the form of short, high torque peaks having pulses in the output shaft of the impact wrench. If a screwdriver bit, as described, for example, in WO 2010/054169 A1, is inserted in the chuck of the impact wrench, then the energy pulse is introduced into the drive section of the bit. The bit described there has a torsion zone, which can rotate under caching of the energy. WO 99/11436 shows a force transmission profile with interlocking polygonal profiles, wherein an outer polygonal profile can be slightly rotated relative to an internal polygonal profile, which is traceable to a movement play. The invention has the object of developing a generic torque transmission device to the effect that it is better usable with a rotary impact wrench, in particular provided that the output to the drive shaft energy pulses are cached such in the torsion that the height of the torque peaks on the output side are passed, be reduced. The object is achieved by the invention specified in the claims.

First and foremost, it is provided that the angle of rotation in the direction of screw rotation is greater than in the screw release direction. Preferably, the angle of rotation in the screw release direction is equal to zero or almost zero. When using such a torque transmission device on an impact wrench, this has the advantage that, when the screw is tightened, the energy pulses introduced into the drive shaft in high frequency one behind the other are stretched in time, so that the torque peaks are reduced. On the other hand, however, the torque transmission device is capable of transmitting an at least first high rotary impact to the output side during a rotation in the opposite direction, that is to say in the screw release direction. This makes it possible, on the one hand tighten screws, without in particular in the final phase of the screwing into the torque transfer device introduced high torque peaks are transmitted to the bit and the screw, however, to loosen the screws, a high torque peak is available, in the rule a single twist is sufficient to loosen a stuck screw. In a preferred embodiment, the stop section has a

Polygonal outer cross-section profile, which rests in such a cross-sectional larger polygonal internal cross-sectional profile of the drive cavity, that the torsion can only be limited by a predetermined rotation angle limited stop, the polygonal profile sections in the torque unbalanced condition against each other are angularly offset. The angular offset of the two polygonal profiles is selected such that in the torque-unbraked state, a polygonal edge of the polygonal outer cross-sectional profile rests against a polygonal surface of the polygonal cross-sectional profile. The two polygonal cross-sectional profiles are preferably profiles with a cross-section in the form of a regular hexagon. The outline contour the hexagonal inner cross section profile of the sleeve part is slightly larger than the hexagonal outer cross section profile of the drive shaft. The captive portion of the drive shaft, which is formed by an end portion of the drive shaft, rotatably and axially fixed in a portion of the drive cavity of the sleeve member. The relevant section of the sleeve part may be formed by a circular cylindrical cavity, in which in the manufacture of the torque transmission device of particular a hexagon plan having captive portion is pressed. The torsion section is followed by a torsion section to form a transition section. The torsion portion is formed by a circular cylindrical portion of the drive shaft having a minimum length and a maximum diameter. The length should be at least 15 mm. The diameter should not be more than 6 mm, preferably not more than 5 mm. But it should not be less than 4 mm. By way of a further transition section, a stop section adjoins the torsion section, which is formed by the above-mentioned polygonal outer cross-sectional profile, which lies with a rotational play in the polygonal cross-sectional profile of the sleeve section. The polygonal edges of the bondage section are aligned with the polygonal edges of the stop zone. If the multi-edge edges of the polygonal outer cross-section profile rest against the polygonal surfaces of the polygonal cross-sectional profile in the torque-unbolted state, the torsion section can twist only in one direction of rotation of the torque-transmitting device, ie be twisted. If the rotation of the drive shaft on the output side a torque load set against conditions, as occurs, for example, when screwing a wood screw in wood, the torsion can twist limited stop. In this case, the polygonal outer cross-sectional profile in the polygonal cross-sectional profile initially rotates by a first angular amount relative to the anchoring section until the polygonal surfaces of the polygonal outer cross-sectional profile run parallel to the polygonal surfaces of the polygonal cross-sectional profile. profile. An increase in the torque leads to a further rotation of the polygonal outer cross-sectional profile relative to the polygonal cross-section profile until the stop position is reached, in which abut the polygonal edges of the polygonal outer cross-section profile on the polygonal surfaces of the polygonal cross-section profile. If this position is reached, for example after a total torsion angle of 20 °, the torsion section has its greatest torsional stress. The torsion section has stored the largest energy in this position. The production of the torque transmission device takes place by the production of two semi-finished products, namely a sleeve part and a drive shaft. Between the insertion opening for the polygonal section of a bit and the polygonal cross-sectional profile, the sleeve part has an enlarged diameter cavity section and a press-in section adjoining the insertion opening and having a circular cylindrical inner contour. In the stepped transition region of the middle section to the press-in zone orientation recesses are provided, which are arranged in a uniform circumferential distribution. The orientation recesses correspond to corner angles of a hexagonal profile. The corner angles are offset by about 10 ° with respect to the multiple corners of the multi-channel cross-sectional profile. A second semi-finished product forms the drive shaft. It is a hexagonal cross-section profile bar which has a circular guide section at its output end, with which the drive shaft can be inserted into the press-in zone. A circumferential groove adjoins this guide section forming a circular disk. The bondage section adjoins the circumferential groove, which has the full polygonal outer cross-sectional profile in the form of a hexagonal profile. In the area between bondage section and stopper section, a torsion section is formed by material reduction. The torsion section is again followed by the full hexagonal outer cross-section profile up to an annular throat, which is inserted in the chuck of the drive tool and into which a detent ball of a chuck of a drive tool can engage. to Manufacture of Drehmomentübertiagungsvorrichtung the drive shaft is inserted with the guide portion first through the drive-side polygonal opening of the sleeve member until the guide section enters the press-in zone. The polygonal edges of the bondage section find the orientation recesses which are offset in relation to the polygonal cross-sectional profile in such a way that, in the found state, the polygonal edges of the polygonal outer cross-sectional profile abut against the polygonal surfaces of the polygonal cross-sectional profile. In this state, the drive shaft is pressed by applying an axial force in the sleeve part, wherein the polygonal edges of the bondage section deform the Einpresshöhlung. In the pressed state, the end face of the guide section forms a contact surface for the end face of the hexagonal section of the bit. For the axial restraint of the bit in the insertion opening, the latter has an inner ring groove, in which a spring ring rests, which is supported on a shoulder or in a Eckausspa- the bit and thus causes an axial bondage. The torsion zone is dimensioned so that it can implement in succession on the drive shaft exerted rotational shocks in a deformation in a deformation. It relaxes in 10 ms - 20 ms, so that several thousand beats per minute can be effectively damped.

In a variant of the invention it is provided that the drive shaft has a second torsion portion. The first torsion section can be made of steel with a material hardness of 44 HRC to 62 HRC, so that a torque of 20 Nm is required to apply the maximum stop-limited rotation of Torsionsab- section. The second torsion portion located between the drive end of the drive shaft and the sleeve portion has a larger diameter, for example, greater than 5.5 mm, as the first torsion portion which is disposed within the drive cavity of the sleeve member. The length of the second torsion section is less than the length of the first torsion section and may be less than 10 mm. Furthermore, it proves to be advantageous if the material hardness of the second torsion section is greater than the material hardness of the first torsion section and in particular more than 55 HRC or 62 HRC. The second torsion section can rotate without a stop limit.

The torque transmission device according to the invention is advantageously used in combination with an impact wrench and a Phillips screwdriver bit. The drive end of the drive shaft is rotatably in the lining of the rotary impact wrench. The rotary impact wrench has a striking mechanism which emits energy pulses in the form of rotary strikes. These energy pulses are latched in the torsion section and delivered to the Phillips bit in a temporally stretched manner, so that the torque peaks have been smoothed. It is considered to be particularly advantageous if the torsion section, which has a diameter of approximately 5 mm and a length of approximately 15 mm, is twisted by 20 ° into a stop position with a static torque of 20 Nm.

A development of the invention is characterized in that the sleeve part 1 has a tool engagement profile. The Werkzeugangriffs- profiling is particularly designed as a hexagonal section, at the

Hexagonal surfaces can attack a spanner or a ring spanner to apply to the sleeve portion, bypassing the drive shaft large torques. This is particularly advantageous if fixed screws are to be loosened or tightened and a drive tool operated by an accumulator can not apply the required torque due to the accumulator being emptied. The polygonal zone is preferably located on the outside at the end of the sleeve part facing away from the insertion opening. The invention will be explained with reference to embodiments illustrated in the accompanying drawings. Show it:

1 is a view of a first embodiment of the invention,

2 is a section along the line II - II in Fig. 1,

3 is a section along the line III - III in Figure 2 in non-torque-loaded state,

4 shows a representation according to FIG. 3, wherein, according to a torque applied to the drive shaft 2, a polygonal outer cross-sectional profile section 20 of the drive shaft 2 is rotated relative to a polygonal cross-sectional profile section 9 of the sleeve part 1 by an angle of rotation α of 10 °, such that the polygonal outer surfaces 20 "run parallel to the polygonal inner surfaces 10,

5 shows an illustration according to FIG. 4, wherein the torque exerted on the drive shaft 2 is above 20 Nm, so that the polygonal edges of the polygonal outer cross-sectional profile 20 rest against the polygonal surfaces of the polygonal cross-sectional profile 9;

6 is a section along the line VI - VI in Fig. 2 by the bondage section,

7 shows a section along the line VII - VII in FIG. 2 through the insertion opening,

8 is a longitudinal section through the sleeve part without therein einsteckendem drive shaft, 8 shows a perspective view of the sleeve part cut according to FIG. 8, FIG. 10 shows a section according to the line X-X in FIG. 8 through orientation recesses 7 of the press-in zone 6,

11 is a perspective view of the not inserted into the sleeve part 1 drive shaft 2,

12 is a side view of a drive shaft 2 of a second embodiment,

Fig. 13 is a perspective view of a third embodiment.

The torque transmission device shown in FIGS. 1 to 7 essentially consists of the sleeve part 1 shown in FIGS. 8 to 10, into which either the drive part 2 shown in FIG. 11 or in FIG. 12 is inserted in the form of a drive shaft 2 ,

The sleeve part 1 is made of metal and is essentially a cylindrical hollow body. The cavity of the hollow body initially consists of an insertion opening 4, which has a Vi-inch hexagon socket profile into which an inner hexagonal profile section 25 of a screwdriver 3 can be inserted. The hexagon socket profile 4 has an inner ring groove 5, in which a spring ring 13 is inserted, which applies to inserted into the insertion 4 hexagonal portion 25 of the screwdriver bit 3 to a shoulder 26, thereby avoiding pulling out the screwdriver bit 3 from the insertion opening 4. The screwdriver bit 3 has an adjoining the hexagonal portion 25, substantially circular cylindrical shaft 24, which can twist by a certain twisting angle with respect to a Phillips tip 23 of the screwdriver bit 3.

The insertion opening 4 of the sleeve part 1 is followed by a press-in zone 6, which has a circular outline in the raw state.

The press-in zone 6 is followed by an enlarged diameter middle section 8, which is part of a drive cavity. Between middle section 8 and press-in 6 a step is created. In the step area, the press-in zone 6 has orientation recesses 7 arranged in a uniform angular distribution. The orientation recesses 7 are hexagonally arranged corner recesses.

At the middle section 8 is followed by a hexagonal opening to the drive side 12. This hexagonal opening forms a polygonal cross-sectional profile 9. The drive shaft 2 shown in Figures 2 and 11 is made of an elongated hexagonal steel profile. By a machining operation, for example. By a turning, the output side end of the hexagonal rod is formed into a guide portion 14. The guide section 14 is formed by a circular disk-shaped end section, wherein the diameter of the guide section 14 substantially corresponds to the diameter of the press-in zone 6. The guide section 14 is followed by an annular groove 15. At the annular groove 15 is followed by a plan view of a regular hexagon forming bondage section 16. A torsion section 18 is located between the bondage section 16 and the drive-side end of the drive shaft 2 and in particular a stop section. By forming a transition section 17 and a transition section 19, a cylindrical torsion section 18 with a length L of approximately 15.5 mm and a diameter is formed by material removal made of about 4.5 mm or 4.7 mm. The material hardness of the torsion portion 18 is 44 HRC to 55 HRC.

The cross-sectional contour of the polygonal outer cross-sectional profile 20 corresponds to the cross-sectional contour of the bondage section 16. The stop zone formed by the polygonal outer cross-sectional profile 20 goes steplessly into the

Drive shaft over, which forms a ring throat 21, to which an end portion 22 connects. In the production of the torque transmission device, the drive shaft 2 is inserted with the guide portion 14 in the forward to the drive side 12 open polygonal cavity, which is formed by Mehrkanünnenquerschnittsprofil 9, until the guide portion 14 is in the press-in zone 6. Then, the drive shaft 2 is rotated relative to the sleeve part 1 such that the multiple corners of the bondage section 16 enter the orientation recesses 7.

Since the distance between two opposing polygonal surfaces of the polygonal cross-sectional profile 9 is greater than the distance between two opposing polygonal surfaces of the polygonal outer cross-sectional profile 20, the polygonal outer cross-sectional profile 20 can rotate relative to the multichannel cross-sectional profile 9 into the position shown in FIG. 3, in which all the polygonal edges 20 'of the polygonal outer cross-section profile 20 each rest against a polygonal surface 10 of Mehrkanunnenquerschnittsprofils 9. In this position, the polygonal edges of the bondage section 16 enter the Orientation recesses 7 a. By increasing the axial pressure, the binding section 16 is pressed into the press-in zone 6.

In the finished state, the end face of the guide portion 14 forms the bottom of a recess. At the bottom of the front side of the hexagonal portion 25 of the bit 3 is located.

If a torque in the left direction is applied to the chuck shown in the figures, then the torsion portion 18 is not twisted, since the torque is introduced into the polygonal surfaces 10 via the polygonal edges 20 '.

If, on the other hand, a torque is applied to the drive shaft 2 in a clockwise direction, that is to say in the right-hand direction, then the polygonal edges 20 'can become detached from the polygonal surfaces 10, for example, into the position shown in FIG.

The Torsionsabschnitt 18 can be rotated a total of 20 ° until the stop position shown in Fig. 5 is reached, in which the polygonal edges 20 'of the Mehr kantaußenquer-sectional profile of the multi-edge surfaces 10 of the polygonal inner cross-section profile 9 abut. The polygonal edges 20 'thus form stops and the polygonal surfaces 10 stop surfaces.

The second embodiment shown in FIG. 12 has an additional torsion portion 18 'which lies outside of the sleeve part 1. The diameter of the second torsion section 18 'is approximately 5 to 6 mm. The length of the second torsion section is less than the length of the first torsion section and is less than 7 mm. The second torsion section 18 'essentially only takes effect when the first torsion section 18 has already been rotated to the stop position. If the chuck shown in the drawings is used with a rotary impact driver, as described, for example, in DE 10 2008 005 831 A1, the high torque peaks, which are more than 100 Nm, supplied by the rotary impact driver are reduced to lower torque peaks. whose maximum values are 20 Nm. The energy pulses delivered by the rotary impact driver are transmitted via the torsion section 18 to a cross-slit bit 3, wherein the pulse length is temporally stretched and the torque peaks are reduced.

The third exemplary embodiment shown in FIG. 13 essentially corresponds to the first exemplary embodiment, in which case the sleeve part 1 has a hexagonal section 27 in the region of the drive shaft 2. It is a hexagonal outer profile with a common wrench size, so that - as shown in FIG. 13 - on the hexagonal portion 27 can attack an open-end wrench to apply to the sleeve part 1 a high torque. This is particularly advantageous if tight-fitting screws to be solved or screws to be tightened.

All disclosed features are essential to the invention. The disclosure content of the related / attached priority documents (copy of the prior application) is hereby also incorporated in full in the disclosure of the application, also for the purpose of including features of these documents in claims of the present application. The subclaims characterize in their optionally sibling version independent inventive development of the prior art, in particular in order to make divisional applications on the basis of these claims. LIST OF REFERENCE NUMBERS

1 sleeve part 27 hexagonal section

2 drive shaft

3 screwdriver bit

 4 insertion opening, polygonal opening

 5 ring groove

 6 press-in zone

 7 orientation recess

8 middle section

 9 polygonal cross-section profile

 10 stop surface

 11 output side

 12 drive side

13 spring washer

 14 guide section

 15 circumferential groove

 16 bondage section

 17 transition section

18 torsion section

 19 transition section

 20 polygonal profile cross section

 21 throat

 22 end section

23 Phillips tip

 24 shaft

 25 hexagonal section

 26 shoulder

Claims

 Torque transmission device with a sleeve part (1) having on its output side (11) a non-circular, in particular a polygonal cross-section having insertion opening (4) for a screwdriver bit (3) and on its drive side (12) one with a captive portion (16), a stopper portion (20 ', 20 ") and an intermediate, in a torque application entangling torsion portion (18) in a drive cavity (6, 8, 9) of the sleeve part (1) stuck drive shaft (2), wherein the drive shaft (2) by means of Torsion portion (16) rotatably and axially fixed to the sleeve part (1) is connected, and along with a twisting of the Torsionsabschnittes (18) is rotatable, the rotatability of the stopper portion (20 ', 20 ") in Schraubenfestdrehrichtung and in screw release direction each stop-limited, characterized in that the angle of rotation of the stop portion (20 ', 20 ") in Schraubenfestdr greater than in the screw release direction.

Torque transmission device according to claim 1 or insbesonde¬ re afterwards, characterized in that the angle of rotation of the stopper portion (20 ', 20 ") in the screw release direction is zero or almost zero.

Torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized in that the abutment portion (20 ', 20 ") has a polygonal outer cross-sectional profile (20) which in such a cross-sectional larger polygonal internal cross-section profile (9) of the drive cavity (6, 8, 9) that the torsion section (18) can only be twisted limited by a predetermined angle of rotation with an angular offset of the polygonal internal cross-sectional profile (9) to the polygonal outer cross-section profile (20) in the torque uninvoked state.

Torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized in that the multi-edges (20 ') of the polygonal outer cross-section profile (20) in the torque uninvoked state abut the polygonal surfaces (10) of the multi-kantinnenquer-sectional profile (9).

Torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized in that the bondage section (16) and the polygonal outer cross-sectional profile (20) are substantially identically designed hexagonal outer profile sections.

Torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized in that the polygonal outer cross-section profile (20) at a Drehmomentbeaufschlagung of the drive shaft (2) relative to the bondage portion (16) initially rotated by an angle (a) to a middle position, in in which the polygonal surface section (20 ") of the polygonal outer cross-sectional profile (20) runs substantially parallel to a stop surface (10) formed by the polygonal cross-sectional profile (9) and the maximum torsion of the torsion section (18) is reached if a polygonal edge (20 ') of the polygonal outer cross-sectional profile (20) touches the abutment surface (10) of the polygonal cross-sectional profile.

Torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized records that the stop-limited angle of rotation of the torsion portion (18) is about 20 °, wherein the torque required to reach the stop position is 20 Nm.

Torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized in that the length (L) of the Torsionsabschnitts is at least 15 mm.

Torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized in that the diameter (D) of the torsion portion (18) has a value of at least 4 mm and a maximum of 5 mm.

Torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized by a material hardness of the torsion portion (18) of 44 HRC to 62 HRC. 11. A torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized in that a press-in zone (6) of the drive cavity orientation recesses (7), in which during pressing of the drive shaft (2) in the sleeve part (1) Mehrkantecken the Fesselungsabschnittes ( 16).

12. torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized in that the angular arrangement of the orientation recesses (7) offset relative to the polygonal corners (10 ') of the polygonal cross-section profile (9).

13. A torque transmission device according to one or more of the preceding claims or in particular, characterized by a in the press-fitting before the polygonal profile having a shackle section (16) arranged a circular profile having guide portion (14), wherein the diameter of the guide portion (14) is slightly smaller than the diameter of the circular outline having Einpresszone (6).

Torque transmission device according to one or more of the preceding claims or in particular according thereto, characterized in that the drive shaft (2) Torsionsabschnitte (18, 18 '), wherein the second torsion portion (18') has a greater torsional stiffness than the plug inside the drive cavity first torsion (18).