EP2629937A1 - Power drill - Google Patents

Abstract

A power drill with percussive drilling, drilling and screwing functions has a gear mechanism for transmitting the driving movement of a driving unit to a tool spindle (4). Also provided are two latching elements (16, 17), which in the percussive drilling position are in latching engagement and in the drilling or screwing position are disengaged. A mode setting device (7) has a rotatable supporting ring (8) and a pressure ring (9), which is coupled with the supporting ring (8) for rotation therewith and in the screwing position is held axially movably on the gear casing (3).

Description

 Description title

 The invention relates to a drilling machine with impact drilling, drilling and

Schraubfunktion.

PRIOR ART DE 198 09 133 A1 describes a hand-held drill driver which can be used as a drilling machine, percussion drill or electric screwdriver. The various operating modes of the drill are adjusted by means of an adjusting sleeve, wherein for use as a screwdriver a torque input is possible, whereas in the impact drilling and Bohr- tion a rigid torque coupling is given. The rigid coupling is made by means of coupling parts, which are to spend in a rotationally locked connection.

Disclosure of the invention

The invention has for its object to be able to set the various operating modes of a drill safely over a long period of operation. This object is achieved with the features of claim 1. The dependent claims indicate expedient developments.

The drilling machine according to the invention is in particular a hand drill having a drive device for driving a tool received in a tool spindle. The drive device comprises a drive unit, usually an electric drive motor, and a coupled to the drive unit gearbox, such as a planetary gear. The drill can be operated in a variety of operating modes, including a percussion drilling function, a drilling function and a screw function. In the impact drilling and drilling function there is a fixed torque coupling between the tool spindle and the drive device, whereas in the screwing function an adjustable torque is transferable.

To realize the Schlagbohrfunktion engage two locking elements snap fit into each other, which are in the drilling and in the screwing disengaged. The locking elements form a detent mechanism in which a sinusoidal or sawtooth-like wave profile is scanned and the resulting axial movement is transmitted to the tool spindle. For this purpose, the tool spindle is advantageously held axially adjustable relative to the transmission housing.

To set the various operating modes is a Moduseinstelleinrichtung which includes a rotatable by manual operation support ring and a rotatably coupled to the support ring pressure ring which is supported on the transmission housing. The support ring is advantageously rotated by means of a manually operable mode setting sleeve. The support ring and the pressure ring are also rotatably mounted about the longitudinal axis or spindle axis and perform the rotational adjustment movement of the mode setting with. The modes Schlagbohr-, drilling and screwing each one rotational position of the mode setting is assigned.

The supported on the gear housing pressure ring Moduseinstelleinrichtung is held axially displaceable in the screwed position on the gear housing and fixed in the Schlagbohr- and in the drilling position axially on the gear housing. The support ring, with which the pressure ring is firmly connected in the direction of rotation, however, is suitably mounted fixed in the axial direction and without adjustment relative to the transmission housing.

Due to the axial adjusting movement in the screwing position, the pressure ring can, in the event that the torque exceeds an adjustable threshold, axially lift off the gear housing, whereby the torque limit is reached.

In the Schlagbohr- and in the drilling position, however, the pressure ring is axially fixed to the gear housing, so that in these modes no torque limiting takes place. The axial fixation is advantageously achieved via a form fit in the axial direction, wherein for transferring between axially positively secured position and axial adjustment of the pressure ring including support ring is rotated, in particular by means of Moduseinstell- sleeve. The axial positive engagement is preferably achieved via an engagement of a radially inwardly projecting projection on the pressure ring in a corresponding recess, for example, a circumferential groove on the transmission housing. In the screwing position with axial adjustment possibility projection and recess or circumferential groove, however, in disengagement. The projection on the pressure ring and the recess or the circumferential groove on a portion of the transmission housing can each intermesh with small tolerances, so that in particular the overall tolerance in the axial transmission chain is low. In this way, a high setting accuracy over a long period of operation is guaranteed.

To activate and deactivate the Schlagbohrfunktion one of the locking elements is held axially adjustable and this locking element or a component connected to the locking element is supported on a Verstellkontur, which is located on the support ring. The adjustment contour allows a transfer of the locking element between different axial positions and thus a transfer between the latching engagement with the further housing-side fixed latching element and a disengagement with this latching element. The detent drilling function is activated in the detent engagement, but disabled in disengagement. About the Verstellkontur which expediently extends in the circumferential direction of the support ring, the contour can be scanned by a relative movement between the locking element or the component held thereon and the support ring, resulting in the desired axial displacement of the locking element. The rotational movement of the support ring is here, as stated above, preferably generated by means of Moduseingstellhülse. Advantageously, it is in the coupled with the locking element component which scans the Verstellkontur on the support ring to a locking member, which is fixed in the direction of rotation, but held axially adjustable in the housing of the drill together with the locking element. The locking element and the locking member are advantageously fixedly connected in the axial direction with the tool spindle, but they do not perform the rotational movement of the tool spindle.

The support ring and the pressure ring are advantageously designed as separate components. In order to achieve a coupling in the direction of rotation between these components, at least one axially projecting shoulder is preferably formed on the support ring, which engages in a corresponding recess on the pressure ring. Furthermore, it is expedient that the support ring surrounds the pressure ring at least partially radially, so that the support ring has at least partially a larger diameter than the pressure ring. In the area between a plurality of circumferentially spaced recesses for interlocking coupling with shoulders on the support ring, it may also be expedient to form the pressure ring and the support ring with the same diameter. For torque adjustment in the screwing is expediently a

Spring device provided with two spring retaining rings and at least one intermediate spring element, wherein the spring means exerts an axial force on the pressure ring. The two spring retaining rings are axially spaced from each other and force-coupled with each other via the at least one intermediate spring element. Advantageously, a plurality of spring elements distributed over the circumference, in particular compression springs between the spring retaining rings are arranged. On the side facing away from the pressure ring, the spring retaining ring of the spring device is to be adjusted axially by a torque adjustment sleeve, which is expediently rotatable but axially fixed to the housing. The spring holding ring can engage with a thread in an associated thread on the torque setting sleeve, so that, upon a rotational movement of the torque setting sleeve, the spring retaining ring carries out an axial adjusting movement due to the axial fixing of the torque setting sleeve. As a result, the axial distance between the first, directly resting on the pressure ring spring retaining ring and the second, acted upon by the moment setting sleeve spring ring decreases. This leads to a changed preload in the min. at least one spring element and thus to a changed axial force which is exerted on the pressure ring. As the axial force increases, the torque which can be transmitted in the screwing function increases.

The pressure ring contacting the spring retaining ring expediently has a smaller diameter than the support ring and is encompassed in the mounted position of the support ring. In this way, a compact, small-sized design is achieved.

Furthermore, in an advantageous embodiment, a detent spring element is provided, which acts on the torque setting sleeve with a detent torque. In this way, a plurality of locking positions of the torque adjusting sleeve can be specified, in which the torque setting sleeve is acted upon in each case with a latching torque. To adjust the torque adjustment the cogging torque must be overcome.

Further advantages and expedient embodiments can be taken from the further claims, the description of the figures and the drawings. Show it:

1 is a perspective view of a detail of a drill, with a gear housing and a mode setting for setting the operating mode and a torque setting,

2 shows the detail of the drill in a side view, but without setting sleeves,

3 shows a section through the drilling machine, FIG. 4 shows the drilling machine in percussion drilling position, FIG. 5 shows the drilling machine in the drilling position, FIG.

6 shows the drill in a screwed position, Fig. 7 is another view of the drill in screwing, but without spring holder, which is part of a spring device for applying force to a pressure ring on the transmission housing. In the figures, the same components are provided with the same reference numerals.

In Fig. 1, a drill 1 is shown in fragmentary form, which is a hand-held drill with the functions impact drilling, drilling and screws. The drilling machine 1 has a drive device which comprises an electric drive motor and a gearbox 2 in a gearbox housing 3. The gearbox 2 transmits the rotary motion of the drive motor to a tool spindle 4 for receiving a tool. To set the various operating modes is a Moduseinstellhülse 5, which is rotatably mounted relative to the gear housing 3 about the longitudinal axis of the drilling machine or the longitudinal axis of the tool spindle 4. By a corresponding rotation of the Moduseinstellhülse 5, the functions impact drilling, drilling and screws can be adjusted. Furthermore, a torque adjustment sleeve 6 is provided, which adjoins directly to the mode setting sleeve 5 and is also rotatable about the spindle longitudinal axis. The sleeves 5 and 6 are independently operable. About the moment setting sleeve 6, the maximum transmittable torque can be adjusted in the screw function of the drill.

In Fig. 2, the drill without Modeeinstellhülse 5 and without torque adjustment sleeve 6 is shown. The drilling machine comprises a Moduseinstelleinrichtung 7, on the one hand the Moduseinstellhülse 5 (Fig. 1) and on the other hand a support ring 8 and a pressure ring 9, which are rotatably mounted respectively on the transmission housing 3. The pressure ring 9 is located at a greater axial distance from the free end face of the tool spindle 4 than the support ring 8 and rests on the transmission housing 3 directly or on balls on an annular shoulder. Of the

Support ring 8 is fixedly connected in the direction of rotation with the pressure ring 9. The support ring 8 is fixed in the axial direction substantially unopposed relative to the housing, wherein for tolerance reasons, an axial movement play for engagement with the torque adjustment can be advantageous. The pressure ring 9 can basically an axial adjusting movement relative to the housing 3 and the

Perform support ring 8. Furthermore, the drill 1 is provided with a spring device 10, which has the function to determine a maximum transferable torque in the screwing operation of the drill. To the spring device 10 includes a plurality of distributed over the circumference arranged spring elements 1 1, which are each designed as helical compression springs, and a first, annular spring holder 12 on the transmission housing 3 and a second, offset parallel arranged spring retaining ring 13. The spring elements 1 1 extend between the two spring retaining rings 12 and 13. The spring retaining ring 13 can be adjusted axially, whereby the bias of the spring elements 1 1 changes. The first spring retaining ring 12 is located directly on the pressure ring 9 of the Moduseinstelleinrichtung 7 and acts on this with an axial force against the transmission housing 3. With increasing bias of the spring elements 1 1 thus also increases the axial force exerted by the spring means 10 on the pressure ring 9 becomes.

The mode setting sleeve 5 is rotatably coupled to the support ring 8, which in turn is rotatably connected to the pressure ring 9. During a rotational movement of the mode setting sleeve 5, therefore, both the support ring 8 and the pressure ring 9 are rotated about the longitudinal axis.

In Fig. 3 is a section through the drill 1 is shown. The tool spindle 4 is rotatably mounted relative to the transmission housing 3 via two axially spaced ball bearings 14 and 15. In addition to the rotational movement, the tool spindle 4 can also be an axial adjusting movement relative to the gear housing

3 execute. For this purpose, the second ball bearing 15 is axially fixedly connected to the tool spindle 4 and slidably mounted within a housing-fixed locking pot 16. The first ball bearing 14, however, is arranged fixed to the housing. Due to the axial displacement, the tool spindle 4 is adjusted between the impact drilling position and the drilling or screwing position. In the Schlagbohrposition the tool spindle 4 is moved to the left, ie into the gear housing. In this case, the locking pot 16 comes into latching engagement with a locking disk 17 which rotatably rests on the lateral surface of the tool spindle 4. The locking disk 17 also has the task of the ball bearing 15, which is also seated on the lateral surface of the tool spindle 4, axially on the

To fix the tool spindle. Within the locking pot 16, a spring element 18 is arranged, which forces the tool spindle 4 in the locking position, in which the locking pot 16 and the locking plate 17 are in detent position.

The spring retaining ring 13, which forms the spring device together with the first spring retaining ring 12 and the intermediate spring elements, is screwed to the torque setting sleeve 6, wherein the torque setting sleeve 6 is fixed in positionally fixed, whereas the spring retaining ring 13 is axially adjustable. During a rotational movement of the torque adjusting sleeve 6, the spring retaining ring 13 moves axially due to the screwing, whereby the bias of the spring device is changed.

In order for the torque adjustment sleeve 6 to latch in discrete detent positions, the torque adjustment sleeve 6 is subjected to a force of a detent spring element 20 which is held on a detent spring holder 19, wherein the detent spring holder 19 and the detent spring element 20 are arranged in the inner space encompassed by the torque setting sleeve 6. The detent spring element 20 engages in discrete angular positions by applying a detent contour on the inner side of the torque setting sleeve 6 by the detent spring element 20.

The torque adjustment sleeve 6 is fixed in position axially on the transmission housing 3. This is done by means of a screw 21, which connects a plate 22 with the gear housing 3, wherein the sheet 22 the force acting axially against the detent spring holder 19 against a shoulder on the moment setting 6 and in this way the Momenteneinstellhülse 6.

Fixed with the locking disc 17, a locking member 23 is connected, which rests on the support ring 8. The support ring 8 has on an end face on a Verstellkontur, which is scanned by the locking member 23 and transferred to the locking plate 17 Ü. Axial changes in height in the adjustment contour on the support ring 18 are transmitted by the contact with the locking member 23 on the locking plate 17, so that the locking plate 17 undergoes a corresponding axial change in position. In this way, the latching engagement between the locking disk 17 and the locking pot 16 can be controlled. As can be seen in conjunction with FIG. 2 in FIG. 2, a bump 8a protruding axially in the direction of the free end face of the tool spindle 4 is arranged on the support ring 8, which is part of the adjustment contour on the support ring. Fig. 2 shows as well as Fig. 4, the Schlagbohrposition in which the locking member 23 is located outside of the axially raised hump 8a itself. Thus, the locking plate 17, which is connected to the locking part 23, by the force of the spring element 18 are in latching engagement with the locking pot 16, whereby the Schlagbohrfunktion is realized. Wrd, however, the locking member 23 so far twisted by actuation of the Moduseinstellhülse 5 that the locking member 23 rests on the axially raised cusp 8a of the support ring 8, the latching disc 17 is axially spaced from the locking pot 16 and thus in disengagement with the locking pot. These disengaged positions are realized during drilling (FIG. 5) and during screwing (FIGS. 6, 7).

The pressure ring 9 is axially positively fixed to the transmission housing 3 both in the percussion drilling function (FIG. 4) and in the drilling function (FIG. 5) and can only be adjusted in the direction of rotation so that an axial relative movement of the pressure ring 9 relative to the transmission housing 3 is excluded. For locking in the axial direction engages a radially inwardly facing projection 24 on the pressure ring 9 in a circumferential groove 25 on the gear housing 3, so that the pressure ring 9 is received by its radially inwardly facing projection 24 positively in the circumferential groove 25. On the lateral surface of the housing 3, a plurality of axial grooves 26 are also introduced at regular intervals, which extend up to the circumferential groove 25. In the region of the axial grooves 26 there is no undercut between the projections 24 on the pressure ring 9 and the circumferential groove 25, so that the pressure ring 9 is freely movable in the axial direction. This situation is shown in Figs. 6 and 7, which show the screwed position.

In Fig. 6, the drill 1 is shown with attached first spring retaining ring 12, which is part of the spring means for the axial pressurization of the pressure ring 9. In Fig. 7, the drill 1 for better illustration without the spring retaining ring 12 is shown. In Fig. 6 and Fig. 7, the pressure ring 9 is shown in the same circumferential position in which the drill is in the screwed position. As can be seen in particular from FIG. 7, the radially inward-pointing projection 24 on the pressure ring 9 is in a rotational position in which the projection 24 protrudes into the axial groove 26 on the transmission housing 3. Thus, the pressure ring 9 can be moved with the projections 24 axially along the axial groove 26 against the force of the spring means.

As shown in FIG. 6, distributed over the circumference of the first spring retaining ring 12 a plurality of pins 12 a arranged on which the individual spring elements can be plugged.

Distributed over the circumference a plurality of radially inwardly directed projections 24 are arranged on the pressure ring 9, which protrude in the screw function in associated axial grooves 26 on the gear housing 3.

Claims

claims 1. Drilling machine with impact drilling, drilling and screwing, with a transmission for transmitting the drive movement of a drive unit to a tool spindle (4), with two latching elements (16, 17) in the Schlagbohrposition in latching engagement and in the drilling or With a Moduseinstelleinrichtung (7), which comprises a rotatable by manual operation support ring (8) and a rotatably coupled to the support ring (8) pressure ring (9), which on a transmission housing (3) of the transmission (2 ), wherein by rotation of the mode setting (7) the desired mode is adjustable, the pressure ring (9) held axially displaceable in the screwed position on the transmission housing (3) and axially fixed in the Schlagbohr- and in the drilling position on the transmission housing (3) is, wherein an axially adjustable held latching element (17) or a with the latching element (17) connected to the component (23) for transfer between the Schla gbohrposition and the drilling or screwing is supported on a Verstellkontur on the support ring (8). 2. Drilling machine according to claim 1, characterized in that the tool spindle (4) for the transfer between the Schlagbohrposition and the drilling or screwing position relative to the transmission housing (3) is held axially adjustable. 3. A drill according to claim 1 or 2, characterized in that the pressure ring (9) is held in the axially fixed position axially positive fit on the transmission housing (3). 4. A drill according to any one of claims 1 to 3, characterized in that on the support ring (8) at least one axially projecting shoulder is formed, which engages for coupling in the direction of rotation in a corresponding recess on the pressure ring (9). Drilling machine according to one of claims 1 to 4, characterized in that the support ring (8) surrounds the pressure ring (9) at least partially. Drilling machine according to one of claims 1 to 5, characterized in that a latching element (17) coupled to a locking part (23) on the Verstellkontur on the support ring (8) is supported. Drilling machine according to one of claims 1 to 6, characterized in that a spring device (10) with two spring retaining rings (12, 13) and at least one intermediate spring element (11) for the axial application of force to the pressure ring (9) is provided. Drilling machine according to claim 7, characterized in that the pressure ring (9) facing away from the spring retaining ring (12, 13) is axially adjustable by a torque adjusting sleeve (6). 9. A drill according to claim 7 or 8, characterized in that the pressure ring (9) contacting spring retaining ring (12, 13) of the support ring (8) is encompassed. 10. Drilling machine according to one of claims 1 to 9, characterized in that the torque setting sleeve (6) is acted upon by a detent spring element (20) with a detent torque.