Drill apparatus and drill chuck

A drill chuck and a drill apparatus is provided that includes a drilling machine, which has a motor and a machine spindle that is supported in rotary fashion in a machine housing. The a drill chuck is connected to the machine spindle and can be moved between a clamping configuration and a drilling configuration and has a clamping sleeve and a chuck body in which clamping jaws are movably guided by a threaded connection. When a sliding sleeve is moved relative to the chuck body between a first position that corresponds to the clamping configuration and a second position that corresponds to the drilling configuration, a flow of force traveling from the motor via the machine spindle to the threaded connection is shifted to a flow of force traveling from the motor via the machine spindle to the chuck body and vice versa.

This nonprovisional application claims priority to German Patent Application No. DE 10 2013 113 868.3, which was filed in Germany on Dec. 11, 2013, and which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a drill apparatus, including a drilling machine, which includes a motor and has a machine spindle that is supported in rotary fashion in a machine housing, and relates to a drill chuck, which is connected to the machine spindle and can be moved between a clamping configuration and a drilling configuration, having a clamping sleeve and a chuck body in which clamping jaws are movably guided by means of a threaded connection.

The invention also relates to a drill chuck for a drill apparatus that has a machine spindle and can be moved between a clamping configuration and a drilling configuration and has a clamping sleeve in a chuck body in which clamping jaws are movably guided by means of a threaded connection.

Description of the Background Art

A drill apparatus of this kind and a drill chuck of this kind are known from DE 10 2011 002 331 A1, which corresponds to US 20120274035, in which the drill chuck can be moved between a clamping configuration and a drilling configuration. In this case, a switch ring is used, which moves the machine spindle situated inside the chuck body axially relative to the chuck body of the drill chuck. In this embodiment, a large bearing diameter is required at the machine end and the mechanical attachment to the drilling machine is very complex.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a drill apparatus and a drill chuck , which have a simplified design and a simplified integration of the drill chuck into the drilling machine.

The object relating to the drill apparatus is attained in a drill apparatus in that the chuck body of the drill chuck is supported on a machine spindle in rotary fashion and when a sliding sleeve is moved relative to the chuck body, between a first position that corresponds to the clamping configuration and a second position that corresponds to the drilling configuration, a flow of force traveling from the motor via the machine spindle to the threaded connection is shifted to a flow of force traveling from the motor via the machine spindle to the chuck body and vice versa.

Consequently, the drill chuck is not, as is usually the case, connected to the machine spindle of the drilling machine in a rotationally fixed fashion; instead, the drill chuck is supported on the machine spindle in a rotary fashion. This enables a relative rotation of the chuck body in relation to the machine spindle. In order to move the drill chuck between the clamping configuration and the drilling configuration, it is now no longer necessary to actuate or use an additional adjusting sleeve—situated coaxially outside the drill chuck—in order to axially move the machine spindle relative to the chuck body of the drill chuck. Instead, it is now possible to switch the drill chuck between a clamping configuration and a drilling configuration by moving the clamping sleeve with the sliding sleeve.

In an embodiment, the sliding sleeve is connected to the chuck body in an axially, rotationally fixed fashion and is supported so that it can move axially relative to it. As a result, the sliding sleeve can transmit a force that is transmitted to it—in particular a driving force or a holding force—directly to the chuck body.

It has turned out to be preferable if the sliding sleeve is axially secured to the clamping sleeve and in the first position, is rotationally fixed while in the second position, it is supported so that it is able to rotate relative to the machine housing. The first position corresponds to the clamping configuration in which the chuck body is secured to prevent it from rotating relative to the machine housing. It is thus possible to ensure that a holding force originating from the machine housing can act on the chuck body via the sliding sleeve. In this clamping configuration, the machine spindle can rotate relative to the chuck body, thus driving the threaded connection in order to move the clamping jaws. Conversely, this ensures that in the second position, the sliding sleeve secures the chuck body to prevent it from rotating relative to the machine spindle. The axial securing of the sliding sleeve on the clamping sleeve has the advantage that it enables a movement of the sliding sleeve relative to the chuck body.

In order to make a relative rotation of the machine spindle in regard to the chuck body more operationally reliable, it has also turned out to be preferable if the sliding sleeve is supported on the chuck body in a radially form-fitting fashion and the clamping sleeve has two detent positions.

It is also advantageous if the sliding sleeve has at least one first component for producing a rotationally fixed coupling with at least one corresponding first coupling element of the machine housing. The first component for producing a rotationally fixed coupling is able to support the sliding sleeve in the first position in a simple way so that it is rotationally fixed relative to the machine housing.

It has also turned out to be advantageous if the sliding sleeve has at least one second component for producing a rotationally fixed coupling with at least one corresponding second coupling element of the machine spindle. This second component for producing a rotationally fixed coupling produces a rotationally fixed connection of the machine spindle to the sliding sleeve in the drilling configuration in which the force coming from the machine spindle can be transmitted to the sliding sleeve and from there to the chuck body.

It is also advantageous if the chuck body has at least one first detent seat corresponding to the clamping configuration and at least one second detent seat corresponding to the drilling configuration, if a control cam is situated between the first and second detent seats, and if the clamping sleeve has at least one detent element that corresponds to the detent seats. The different switch positions of the drill apparatus are implemented in this way. The control cam corresponds to the switching device of the clamping sleeve of the drill chuck. The control cam can be embodied as ascending, but does not have to be.

It has also turned out to be preferable that a roller bearing or slide bearing is provided for supporting the chuck body on the machine spindle in rotary fashion. In a preferred embodiment, the roller bearing is embodied in the form of a needle bearing, which has the advantage that it can be embodied in a very thin and compact way.

In another embodiment, the threaded connection is composed of a clamping thread of the clamping jaws, which are embodied in the form of round jaws, and a threaded ring that engages with the clamping thread. An integrated round-jawed drill chuck is thus achieved.

In this connection, it has also turned out to be advantageous if a planetary gear is situated between the threaded ring and the machine spindle. According to another embodiment, this planetary gear is composed of a ring gear connected to the threaded ring in a rotationally fixed fashion, at least one planet gear situated in the chuck body in rotary fashion, and a sun gear supported on the machine spindle in a rotationally fixed fashion. The use of a planetary gear makes the drill chuck very compact and has the advantage that the input and output shafts are aligned with each other, i.e. lie along a common axis.

In order to support the sliding sleeve during the switching between the first position and the second position, it has turned out to be advantageous if the clamping sleeve, on its side oriented away from the machine spindle, is axially supported by a spring element. During the movement of the sliding sleeve, the sliding sleeve, which is guided on the chuck body in a rotationally fixed fashion, is moved in the axial direction between the first and second positions.

The axial support of the clamping sleeve can be implemented in the form of a support ring that is acted on by the spring element. This support ring distributes the spring force of the spring element uniformly and in the shape of a ring to the end surface of the clamping sleeve oriented away from the machine spindle.

It has also turned out to be advantageous if on the side of the chuck body oriented away from the machine spindle, a protective cap is provided, which has an annular collar that is recessed—at least in the drilling configuration—into an annular recess of the clamping sleeve. This protective cap covers the clamping sleeve in both switch configurations. In one advantageous embodiment, it is supported in rotary fashion on the chuck body. The protective cap on the one hand protects the drill chuck when during the drilling operation, the drill bit or drilling tool penetrates too deeply into the material to be machined and the material to be machined leaves scrape marks on the chuck body due to the rotational movement. On the other hand, the material to be machined is protected from the turning, i.e. rotating, components of the drill chuck, because when the drill bit or drilling tool penetrates too far, the rotatable protective cap remains stationary against the material to the machined and then the chuck body and the clamping sleeve can rotate relative to the protective cap.

It is also advantageous if a sensor is provided, which sends a signal to the drilling machine as soon as the clamping sleeve is in the first position. A signal is therefore generated that communicates when and whether the drill apparatus is in the drilling configuration. To this end, a switch disk is advantageously provided, which is situated on the side of the clamping sleeve oriented toward the machine spindle. The distance from the switch disk can be measured by a distance transducer that is preferably associated with the drilling machine.

Naturally, the sensor can also be situated on the drill chuck and the switch disk can be situated on the machine housing.

It also turns out to be advantageous if at least one component is provided for adjusting the switching torque. The switching torque is the torque required to switch the drill chuck and the drill apparatus between the clamping configuration and the drilling configuration. The v for adjusting the switching torque can be used to vary the switching torque.

It has also turned out to be advantageous to limit the clamping force. This can be implemented by, for example, a slip clutch. This clutch can be situated axially or radially relative to the chuck body. In addition, when the clamping sleeve is moved, a switch in the machine housing can be actuated, which signals the drilling machine that the drill apparatus is now in the clamping mode. In this case, it is possible to carry out the clamping of the drill bit or drilling tool while carrying out a simultaneous measurement of the motor current, which is proportional to the torque acting on the clamping jaws and can be used as a basis for calculating the clamping force. The variation of the motor current can also be used to vary the clamping force acting on the drilling tool.

The object relating to the drill chuck is attained in a drill chuck of the type mentioned at the beginning, which, when a sliding sleeve is moved relative to the chuck body between a first position that corresponds to the clamping configuration and a second position that corresponds to the drilling configuration, a flow of force traveling from the machine spindle to the threaded connection is shifted to a flow of force traveling from the machine spindle to the chuck body and vice versa.

This is also connected with the advantage that it is possible to change the flow of force inside the drill chuck in a simple way, namely by moving the clamping sleeve.

An embodiment of the drill chuck according to the invention is characterized in that an impact mechanism for impact drilling is provided. By means of this, it is now possible, in addition to a pure rotary or drilling movement, to also execute a hammering or vibrating axial movement in a drill chuck that is integrated into the drilling machine.

DETAILED DESCRIPTION

In order to simplify the explanation of the invention, the figures have been reduced to the components that are relevant to the invention. It is therefore unnecessary to provide an illustration of a whole drilling machine with a motor. The figures show a front part29of a machine housing1oriented toward the drill chuck and a machine spindle2of the drilling machine. The drawings also show a drill chuck that is attached to the machine spindle2.

The drill chuck is a round-jawed drill chuck with clamping jaws6, which are movably guided in guides of the chuck body that are inclined relative to the chuck axis. The clamping jaws6thus form a socket between themselves for a drill bit or drilling tool. In order to adjust the clamping jaws6, a threaded ring17is supported in rotary fashion coaxial to the chuck body4of the drill chuck and, with its thread38, engages a clamping thread16of the clamping jaws6. When the threaded ring17is rotated relative to the chuck body4, this causes the clamping jaws6to clamp or release, depending on the rotation direction of the threaded ring17.

The chuck body4of the drill chuck is supported on the machine spindle2in rotary fashion. When a sliding sleeve31is moved relative to the chuck body4between a first position that corresponds to the clamping configuration (FIG. 1;FIG. 6;FIG. 8) and a second position that corresponds to the drilling configuration (FIG. 2;FIG. 5;FIG. 7;FIG. 9), a flow of force15traveling from the motor via the machine spindle2to the threaded connection5is shifted to a flow force of force50traveling from the motor via the machine spindle2to the chuck body4and vice versa.

The clamping sleeve3is connected to a sliding sleeve31by means of a casing part30. In order to axially secure the sliding sleeve31relative to the casing part30, securing rings32are provided, which are situated against the inner wall33of the clamping sleeve3. Consequently when the clamping sleeve3is moved axially, the sliding sleeve31moves axially as well. Conversely, a machine part of the drilling machine can also be provided, which moves the sliding sleeve axially on the chuck body4in order to switch it between the first position and the second position. In one particular embodiment, the sliding sleeve can also be embodied in one piece with the casing part30.

The sliding sleeve31is supported on the chuck body4in a rotationally fixed fashion. The rotationally fixed support is implemented by means of a form-fitting engagement of the non-round cross-section of the sliding sleeve31and the non-round cross-section of the chuck body4. In the exemplary embodiment, the rotationally fixed support is comprised of a first locking surface52associated with the sliding sleeve31and a corresponding second locking surface53associated with the chuck body4. The non-round cross-sections and locking surfaces52and53are shown inFIGS. 3 and 7.

InFIG. 3, it is clear that in the exemplary embodiment shown, there are exactly three first locking surfaces52and exactly three corresponding second locking surfaces53. It is also possible to use a different number of locking surfaces52,53here in order to transmit a force acting on the sliding sleeve31to the chuck body4. In the present instance, the first and second locking surfaces52,53are situated at an angle between 30 and 80 degrees to each other, in this case exactly 60 degrees. They are axially situated at the level of the guides of the clamping jaws6(e.g. shown on the right side inFIGS. 1 and 2), which has advantages from a production standpoint, e.g. a reduction in the processing time for the chuck body4.

The sliding sleeve31has first indent7for producing a rotationally fixed coupling with corresponding first coupling elements10of the machine housing1. In the exemplary embodiments shown, the machine housing has an anti-rotation lock34with a first coupling element8embodied in the form of a securing denticulation35that can be engaged by the first indent7for producing a rotationally fixed coupling, which is associated with the sliding sleeve31and embodied in the form of a first counterpart denticulation36.

The sliding sleeve31also has a second indent9for producing a rotationally fixed coupling, with corresponding second coupling elements10of the machine spindle2. The second indent9for producing a rotationally fixed coupling, which are associated with the sliding sleeve31and embodied in the form of a second counterpart denticulation37, can engage with the corresponding second coupling elements10of the machine spindle2embodied in the form of a locking denticulation39.

In the exemplary embodiment shown, the chuck body4has three first detent seats11that correspond to the clamping configuration and three second detent seats12that correspond to the drilling configuration. The sliding sleeve31also has three detent elements14that correspond to the detent seats11,12of the chuck body4. Here, too, it is possible for there to be a different number of detent seats11,12and detent elements14. The matching number of detent seats11,12can be different from the number of detent elements14so that there can also be fewer detent elements14than detent seats11,12. According to the preferred embodiment, control cams13are situated between the first detent seats11and second detent seats12. In the exemplary embodiment shown, the chuck body4, for assembly reasons, is composed of multiple parts: a central body40and a body switch ring41connected to the central body40in a rotationally fixed fashion. According to the embodiment shown, the first detent seat11, the second detent seat12, and the control cams13are situated on this body switch ring41. In this instance, the rotationally fixed connection is provided between the central body40and the body switch ring41and in the exemplary embodiment shown, is embodied in the form of a plurality of securing pins42. In order to reduce the weight of the drill chuck, this body switch ring41can be composed of a soft and/or lightweight material, preferably a plastic. In the embodiments shown, a roller bearing15embodied in the form of a needle bearing is provided for supporting the chuck body4in rotary fashion on the machine spindle2. Other types of bearings such as slide bearings, ball bearings, roller bearings, etc. can also be used.

The threaded connection5is composed of a clamping thread16, the clamping jaws6embodied as round jaws, and a threaded ring17that engages with the clamping thread16. The threaded ring17engages by means of a thread38with the clamping threads16of the clamping jaws6and is also connected to a driver sleeve43in a rotationally fixed fashion. On the side of the threaded ring17oriented toward the machine spindle2, another roller bearing44is provided. On the side of the roller bearing44oriented toward the machine spindle2, a pressure ring45is provided, which is in turn supported on the chuck body4.

Between the threaded ring17and the machine spindle2, a planetary gear18is provided. The planetary gear18includes a ring gear19to the threaded ring17in a rotationally fixed fashion, exactly one planet gear20—in the present exemplary embodiment according toFIG. 4—situated on a bearing axis46oriented parallel to the longitudinal axis of the drill chuck, and a sun gear21supported on the machine spindle2in a rotationally fixed fashion. It is also possible for there to be embodiments in which more than just one planet gear20is used. For example, it has turned out to be advantageous to use three or four planet gears. The invention, however, can also be embodied with any other arbitrary number of planet gears20. According to the preferred exemplary embodiment, the ring gear19is press-fitted into the driver sleeve43; it is also possible for the ring gear19and driver sleeve43to be embodied as one piece. This is implemented, for example, by means of a deep-drawn sheet with a denticulation. The sun gear21is press-fitted onto the machine spindle2. The sun gear21can nevertheless also be embodied as integral to the machine spindle2.

On its side oriented away from the machine spindle2, the clamping sleeve3is axially supported by a spring element22. Also to axially support the clamping sleeve3, a support ring23is provided, which is acted on by the spring element22. The spring element22in turn is axially supported indirectly or directly against the side of the chuck body4oriented away from the machine spindle2. In the present instance, a snap ring47is provided on the side of the chuck body4oriented away from the machine spindle2supporting a protective cap24, which has an annular collar25that is recessed—at least in the drilling configuration—into an annular recess26of the clamping sleeve3. According to the embodiment shown inFIGS. 1 and 2, a sensor27is provided, which sends a signal to the drilling machine as soon as the clamping sleeve3is in the first position, which corresponds to the clamping configuration. In the exemplary embodiment shown, this is implemented by means of a switch disk48situated on the side of the clamping sleeve3oriented toward the machine spindle2.

According to another preferred embodiment shown inFIGS. 5 and 6, the annular collar25of the protective cap24has an engaging section49, which is oriented toward the machine spindle2and recessed in a corresponding annular recess26of the clamping sleeve3. According to this preferred embodiment, the engaging section49is recessed in the annular recess26of the clamping sleeve3in both the clamping configuration and the drilling configuration. This has the advantage that no excessive gap or no gap at all is produced when the clamping sleeve3is axially retracted. Finally, in all of the exemplary embodiments shown, the spring element22facilitates adjustment of the switching torque.

According to the advantageous embodiment inFIGS. 6 and 7, the drill apparatus and the drill chuck are equipped with an impact mechanism54. The impact mechanism makes it possible, in addition to the pure rotary movement of the drill chuck on the machine spindle2, to also execute a vibration-like movement in the axial direction, which makes it possible to machine particularly hard materials. The impact mechanism54includes an impact spring57, which is supported against an impact plate55and pushes the impact plate55axially toward the machine housing1. The impact plate55interacts with a structure embodied on the drilling machine. In an alternative embodiment, this structure is likewise embodied on a machine impact plate situated opposite the impact plate55. For the interaction with the machine impact plate, the impact plate provides an uneven end surface58, which in the exemplary embodiment shown, is embodied in the form of a wave-shaped denticulation. When the impact plate55is moved axially toward the front, then in the drilling configuration (FIG. 7), the machine spindle2is likewise moved axially via a driver. The axial movement of the machine spindle2then permits an impact drilling because the axial movement of the machine spindle simultaneously produces an axial movement of the drill chuck. In the clamping configuration (FIG. 6), however, the machine spindle2is axially immobilized so that it is not possible for the machine spindle2and the drill chuck to move along their longitudinal axis. In other words, the impact mechanism54is deactivated in the clamping configuration.

The drill apparatus and drill chuck will be explained below in the operation of the drilling configuration, the changeover of their operating mode, and in the operation of the clamping configuration.

FIGS. 2, 5, 7, and 9show drill apparatuses and drill chucks in the drilling configuration. The sliding sleeve31is situated in the second position in which it has been moved axially forward relative to the chuck body4, i.e. in a direction away from the machine spindle2. The detent elements14have engaged in the second detent seats12(FIG. 9). In this case, the second counterpart denticulation37of the sliding sleeve31engages with the locking denticulation39of the machine spindle2. In other words, the machine spindle2is connected to the sliding sleeve31in a rotationally fixed fashion. The sliding sleeve31is connected to the chuck body4in a rotationally fixed fashion by means of the first locking surface52and the second locking surface53.

Consequently, the flow of force50of the drilling configuration travels from the motor via the machine spindle2, to the sliding sleeve31, via the first and second locking surfaces52and53, to the chuck body4. At the same time, there is no relative rotation of the sun gear21in relation to the planet gear20situated in the chuck body4as a result of which, there can likewise be no relative rotation of the threaded ring17in relation to the chuck body4. Consequently, the drill chuck as a whole rotates with the rotation speed of the machine spindle2.

In order to then be able to move the drill chuck into the clamping configuration according toFIGS. 1, 6, and 9, the clamping sleeve3must be rotated radially in opposition to the force of the spring element22. As a result, the detent elements14of the clamping sleeve3are released from the second detent seats12of the chuck body4. As the clamping sleeve3is rotated further relative to the chuck body4, the detent element14is slid along the control cam13in the direction of the first detent seat11. As soon as the detent element14has engaged in the first detent seat11(FIG. 8), the clamping sleeve3is axially offset toward the rear relative to the chuck body4, i.e. in the direction toward the machine spindle2. The clamping sleeve3is now in the first position. The drill apparatus and drill chuck have arrived in the clamping configuration. In order to move into the drilling configuration, the above sequence must be carried out in reverse order.

In the clamping configuration, the securing denticulation35of the anti-rotation lock34of the machine housing1engages with the counterpart denticulation36of the sliding sleeve31. The engagement of the denticulation supports the sliding sleeve31in a rotationally fixed fashion relative to the machine housing1. The sliding sleeve31is nevertheless connected to the chuck body4in a rotationally fixed fashion via the first and second locking surfaces52and53. In other words, the machine housing1holds the sliding sleeve31, which prevents the chuck body4from rotating by means of the machine spindle2.

Consequently, the flow of force51of the clamping configuration travels from the motor via the machine spindle2to the planet gear20of the planetary gear18. Because the chuck body4is secured to prevent it from rotating, the ring gear19of the planetary gear18rotates and thus drives the threaded ring17. In the embodiments shown, the ring gear19and the threaded ring17are connected in a rotationally fixed fashion by means of a driver sleeve43. The relative rotation of the threaded ring17in relation to the chuck body4causes a movement of the clamping jaws6that are engaged by the threaded ring17. The relative rotation of the machine spindle2in relation to the chuck body4is enabled by the needle bearing that is situated on the machine spindle2, coaxial to the longitudinal chuck axis of the drill chuck.

In order to permit a clamping and releasing, the motor has two rotation directions or directions of travel (clockwise rotation and counterclockwise rotation), as is sufficiently known from the prior art.