Drill chuck and drill

Abstract

The invention relates to a drill chuck (1) comprising a chuck body (2), the rear end of which has a spindle receptacle (3) and the axially front end of which has a tool receptacle (4) into which clamping jaws (6) extend which are movably guided in guide channels (5) in the chuck body (2). An annular collar (11) having a non-circular first outer circumference (12) projects axially rearwardly from the axially rear end of the chuck body (2). A drive socket (13) is provided, which can be fitted onto the annular collar (11) and has a first inner circumference (15) which is adapted to the first outer circumference (12) for transmitting torque. The axial extension of the drive socket (13) is greater than that of the annular collar (11). The invention also relates to a drill.

Description

[0001] Drill chuck and drill

[0002] DESCRIPTION:

[0003] The invention relates to a drill chuck with a chuck body having a spindle receptacle at its rear end and a tool receptacle at its axially front end, into which clamping jaws movably guided in guide channels of the chuck body open, wherein an annular collar with a non-circular first outer circumference projects axially rearward from the axially rear end of the chuck body, wherein a drive bushing is provided which can be slipped onto the annular collar and has a first inner circumference adapted to the first outer circumference for torque transmission, and wherein the axial extent of the drive bushing is greater than that of the annular collar. The invention further relates to a drilling machine.

[0004] A drill chuck is known from EP 0 710 518 A2. For the basic structure and operation of the drill chuck, reference can be made to this document, which reflects the knowledge of the average person skilled in the art. DE 20 2013 101 255 U1 discloses a drill chuck with a chuck body, at the rear end of which a spindle receptacle is formed for coupling to the drill spindle of a drilling machine. The spindle receptacle has an internal thread into which the drill spindle with an external thread can be screwed. A passage formed in the chuck body serves to axially secure the drill chuck relative to the drill spindle; a locking screw can be screwed into a screw receptacle of the drill spindle.

[0005] Modern drills are becoming increasingly powerful and capable of generating high torques in excess of 200 Nm, which must be reliably transmitted to the chuck without overloading the connection between the chuck body and the drill spindle or compromising subsequent detachability, thus also allowing for a chuck change. In particular, it is important to ensure that the drill spindle does not break, as this could endanger the user if the drill chuck separates from the drill during operation. Increasing the material thickness is not an easy solution, as the outer diameter of the drill chuck should not exceed 43 mm, as this value is accepted in the industry and the dimensions are aligned accordingly.

[0006] The object of the present invention is therefore to provide a drill chuck capable of transmitting high torque and simultaneously allowing the user to change the chuck from a drill spindle without having to visit a service center. A further object is to provide a drill suitable for driving the chuck.

[0007] This object is achieved by a drill chuck having the features of claim 1 and by a drilling machine having the features of claim 13. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims.

[0008] The drill chuck mentioned above enables improved power transmission from the drill spindle of a drill. Instead of the widely used screw connection between the spindle and the drill chuck, which is responsible for power transmission, an annular collar with a non-circular first outer circumference now projects axially rearward from the axially rearward end of the chuck body. A drive bushing can be slipped onto the annular collar and has a first inner circumference adapted to the first outer circumference for torque transmission. The axial extent of the drive bushing is greater than that of the annular collar. The interaction of the annular collar and the drive bushing is used to transmit the torque, i.e. the drive takes place independently of any axial securing of the spindle and thus the axial securing is not influenced by the acting torque.The invention makes it easy to manufacture the spindle and the chuck body.

[0009] To increase the material thickness of the drive bushing, it is possible to create channels for the clamping jaws in a second outer circumference of the drive bushing, with a number of them at least equal to the number of clamping jaws. This means that the guidance of the clamping jaws and their position need not be a limiting factor in the choice of the wall thickness of the drive bushing. Guide surfaces for the clamping jaws can be formed in the channels.

[0010] It is particularly preferred if the first outer circumference and the first inner circumference are designed as a polygon, as this allows large torques to be transmitted before shear forces cause deformation of the drive bushing. It is preferred if the polygon is formed by a hexagon, although a different number of edges between 3 and 8 can also be implemented. If a hexagon is selected, providing 3 channels is sufficient for a typical drill chuck with 3 clamping jaws; however, if 6 channels are provided at a 60° distance, incorrect assembly is ruled out. The compactness of the design is promoted if the polygon, in particular the hexagon, is oriented to the guide channels in such a way that it is not the edges but the surfaces connecting the edges that point towards the clamping jaws.

[0011] It is further preferred if a fitting receptacle is formed, staggered axially forwards from the axially rearward end of the chuck body from the spindle receptacle, with a passage extending from the fitting receptacle to the tool receptacle. The diameter of the fitting receptacle is preferably 12 mm, as this allows sufficient remaining material thickness of the chuck body in this area while maintaining a good remaining thickness of the spindle. The diameter of the passage is smaller than the diameter of the fitting receptacle, so that the fitting receptacle can also act as a stop. An internal thread can be formed in the passage.This internal thread does not necessarily or primarily serve to interact with and axially secure the spindle relative to the chuck body, but rather allows the spindle to be pushed out of the spindle mount using a forcing screw, which is particularly advantageous when corrosion may occur in the area of ​​the interface between the spindle and the chuck body under adverse climatic conditions. Secondly, this internal thread can be used for mounting and machining the drill chuck, since the thread otherwise used for this purpose to secure the spindle is not necessarily present. Particularly during grinding operations, considerable additional work is avoided because the use of the locking screw and its assembly and disassembly is no longer necessary.

[0012] If a countersink extending axially forwards from the tool holder to the passage is formed on the passage, the screw head of the locking screw can be inserted there without disturbing the tools or workpieces to be inserted into the tool holder.

[0013] It is advisable for the diameter of the internal thread of the passage to be larger than the diameter of a locking screw extending through the passage, as this prevents the locking screw from engaging the internal thread and prevents the locking screw from interacting with this internal thread.

[0014] The aforementioned advantages and effects also apply to a drill chuck according to the aforementioned embodiments, in combination with a drilling machine having a drill spindle, wherein the drill spindle has, at its end axially facing the drill chuck, an engagement portion with a non-circular second outer circumference, the shape of which corresponds to that of the first outer circumference. Expediently, the drill spindle has, from the engagement portion axially toward its free end, a spindle pin with a pin diameter matched to the fitting receptacle for guidance in the fitting receptacle. The axial extension of the drive bushing ensures that the engagement portion can also enter the drive bushing.

[0015] In addition, a forcing screw with an outer diameter matched to the diameter of the internal thread of the passage can be provided, through which the drilling spindle of the drilling machine is pressed out of the spindle holder when the forcing screw is screwed into the internal thread.

[0016] The design of the drill chuck enables the formation of a combination of a drill chuck of the type mentioned above with such a drilling machine having a drill spindle, wherein the drill spindle has, at its end axially facing the drill chuck, an engagement portion with a non-circular second outer circumference whose shape corresponds to that of the first outer circumference.

[0017] It is preferred if the drilling spindle has a spindle pin with a spindle diameter matched to the fitting receptacle from the engagement section axially to its free end pointing to the guide in the fitting receptacle, since this promotes and enables centering of the spindle relative to the chuck body.

[0018] A better positioning of the spindle relative to the chuck body is also achieved if the end face of the engagement section facing axially toward the free end of the drill spindle is designed as a first flat surface. It is advantageous if the axially rear end of the chuck body is also designed as a second flat surface that interacts with the first flat surface.

[0019] The spindle can be aligned with its spindle journal in the spindle mount via the fit mount, which simplifies axial securing. The inventive design with the drive bushing, which transmits torque between the spindle and the chuck body, means that torques greater than 200 Nm can be transmitted. The axial securing of the spindle can be achieved completely independently of the torque transmission using a locking screw, in particular in M6 format, which extends from the tool holder through the passage to the spindle mount and can be screwed into a screw recess formed in the spindle, thereby pulling the spindle axially down onto the chuck body via the first and second flat surfaces.

[0020] The features and feature combinations mentioned above in the description, as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figure, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention. Thus, embodiments are also considered to be encompassed and disclosed by the invention that are not explicitly shown or explained in the figure, but which emerge and can be produced through separate feature combinations from the explained embodiments.

[0021] Further advantages, features, and details of the invention will become apparent from the claims, the following description of preferred embodiments, and the drawings. Herein:

[0022] Figure 1 shows a longitudinal section through a drill chuck with an attached spindle as part of a drilling machine or machine tool,

[0023] Figure 2 is a perspective view of the drill chuck with the separate drive bushing and the separate spindle,

[0024] Figure 3 is a perspective view of the object of Figure 1,

[0025] Figure 4 is a side view of a drill chuck with the spindle, shown partially in section, Figure 5 is a view corresponding to Figure 4 of the combination of a drill chuck with a grinding or assembly spindle,

[0026] Figure 6 shows a representation corresponding to Figure 4 of the combination of a drill chuck with a forcing screw,

[0027] Figure 7 is a perspective view of an isolated spindle,

[0028] Figure 8 is a side view of the spindle of Figure 7, partially sectioned, and

[0029] Figure 9 shows a representation of an insulated drill chuck corresponding to Figure 4.

[0030] Figure 1 shows a drill chuck 1 with a chuck body 2, which has a spindle holder 3 at its rear end and a tool holder 4 at its axially front end, into which clamping jaws 6, which are movably guided in guide channels 5 of the chuck body 2, open. An annular collar 11 with a non-circular first outer circumference 12 projects axially rearward from the axially rear end of the chuck body 2. Figure 2 in particular shows that there is a drive bushing 13 which can be slipped onto the annular collar 11 and which has a first inner circumference 15 adapted to the first outer circumference 12 for torque transmission. The axial extent of the drive bushing 13 is greater than that of the annular collar 11.

[0031] Figure 2 also shows that in a second outer circumference 24 of the drive bushing 13, at least a number of channels 25 for the passage of the clamping jaws 6 are formed, corresponding to the number of clamping jaws 6, wherein in the exemplary embodiments shown, guide surfaces for the clamping jaws 6 are formed in the channels 25. The number of channels 25 can also be greater than the number of clamping jaws 6, namely if this can prevent misorientation with respect to the clamping jaws 6 when arranging the drive bushing 13. In the exemplary embodiments, the first outer circumference 12 and the first inner circumference 15 are designed as a polygon, namely as a hexagon. The hexagon is oriented in its rotational position on the chuck body 2 such that three of its key surfaces point towards the clamping jaws 6. In this exemplary embodiment, a channel 25 can also be formed on each key surface to prevent misorientation.

[0032] Figures 1 and 3 show that a fitting receptacle 9 is formed axially staggered forward from the spindle mount at the axially rearward end of the chuck body 2, with a passage 10 extending from the fitting receptacle 9 to the tool holder 4. The diameter of the fitting receptacle 9 is, for example, 12 mm. These figures also show that the diameter of the passage 10 is smaller than the diameter of the fitting receptacle 9.

[0033] An internal thread 16 is formed in the passage 10. The embodiment in Figure 5 shows its use in conjunction with a grinding spindle 23 or an assembly spindle, which can be used for the manufacture of the drill chuck 1 and whose assembly is significantly simplified by the internal thread 16.

[0034] A countersink 18 is formed, extending axially forward from the passage 10 from the tool holder 4 to the passage 10, into which a screw head 20 of a locking screw 19 can be inserted. The diameter of the internal thread of the passage 10 is larger than the diameter of the locking screw 19 extending through the passage.

[0035] The drill chuck 1 described above can be combined with a drill having a drill spindle 21, wherein the drill spindle 21 has, at its end axially facing the drill chuck 1, an engagement portion 26 with a non-circular second outer circumference 27, the shape of which corresponds to that of the first outer circumference 12. This engagement portion 26 can engage with the drive bushing 13 during assembly, for which purpose the engagement portion 26 is adapted in its shape to the shape of the annular collar. The axial extent of the drive bushing 13 is also selected such that both the engagement portion 26 and the annular collar 11 can engage with the drive bushing 26, thus creating a torque-transmitting connection between the spindle 14 and the chuck body 2 that is highly resilient.The end face of the engagement section 26 facing axially toward the free end of the drill spindle 21 is designed as a first flat surface 22 and is intended and suitable for interaction with a second flat surface 28 at the axially rearward end of the chuck body 2. A spindle pin 29 serves for centering in the fitting receptacle 9.

[0036] Figure 2 shows how the spindle mount 3 is used to connect to a spindle 14, which is shown in isolation but can be designed as a drilling spindle 21, part of a drilling machine, or as a grinding spindle 23. The locking screw 19 is used to axially secure the spindle 14 in the spindle mount 3; its screw head 20 engages in the countersink 18 and is arranged there. The locking screw 19 pulls the first flat surface 22 of the spindle 14 against the second flat surface 28 of the chuck body 2, thus defining the axial position. The radial position of the spindle 14 is determined by the fit mount 9, which is also used for centering.Figure 5 shows the possibility that for lower stresses, such as when placing a grinding spindle 23 in the spindle holder 3, the passage 10 with its internal thread 16 can also be used to secure the grinding spindle 23, so that then no locking screw 19 has to be mounted and dismounted.

[0037] After removing the locking screw 19, access to the passage 10 with the internal thread 16 is exposed. Using a forcing screw 17 screwed into the internal thread 16, the drilling spindle 21 or grinding spindle 23 can be pressed axially out of the spindle holder 3 (Figure 6). LIST OF REFERENCE SYMBOLS:

[0038] 1 drill chuck

[0039] 2 chuck bodies

[0040] 3 spindle holder

[0041] 4 tool holder

[0042] 5 guide channel

[0043] 6 clamping jaws

[0044] 7 Longitudinal axis

[0045] 8 grooves

[0046] 9 Fitting recording

[0047] 10 rounds

[0048] 11 ring bundle

[0049] 12 first outer circumference

[0050] 13 Drive bushing

[0051] 14 spindle

[0052] 15 first inner circumference

[0053] 16 internal threads

[0054] 17 Forcing screw

[0055] 18 Reduction

[0056] 19 Locking screw

[0057] 20 screw head

[0058] 21 Drill spindle

[0059] 22 first plan area

[0060] 23 Grinding spindle

[0061] 24 second outer circumference

[0062] 25 channel

[0063] 26 intervention section

[0064] 27 second outer circumference

[0065] 28 second plan surface

[0066] 29 spindle pins

Claims

CLAIMS:

1. Drill chuck (1) with a chuck body (2) which has a spindle holder (3) at its rear end and a tool holder (4) at its axially front end, into which clamping jaws (6) which are displaceably guided in guide channels (5) of the chuck body (2) open, characterized in that an annular collar (11) with a non-circular first outer circumference (12) projects axially rearwardly from the axially rear end of the chuck body (2), that there is a drive bushing (13) which can be plugged onto the annular collar (11) and which has a first inner circumference (15) adapted to the first outer circumference (12) for torque transmission, and that the axial extent of the drive bushing (13) is greater than that of the annular collar (11).

2. Drill chuck (1) according to claim 1, characterized in that in a second outer circumference (24) of the drive bush (13) channels (25) for passing through the clamping jaws (6) are formed in a number corresponding at least to the number of clamping jaws (6).

3. Drill chuck (1) according to claim 1 or 2, characterized in that the first outer circumference (12) and the first inner circumference (15) are designed as polygons.

4. Drill chuck (1) according to claim 4, characterized in that the polygon is formed by a hexagon.

5. Drill chuck (1) according to one of claims 1 to 4, characterized in that a fitting receptacle (9) is formed from the axially rearward end of the chuck body (2) from the spindle receptacle (3) axially staggered forwards, and that a passage (10) extends from the fitting receptacle (9) to the tool holder (4).

6. Drill chuck (1) according to claim 5, characterized in that the diameter of the passage (10) is smaller than the diameter of the fitting receptacle (9).

7. Drill chuck (1) according to claim 5 or 6, characterized in that an internal thread (16) is formed in the passage (10).

8. Drill chuck (1) according to one of claims 5 to 7, characterized in that a countersink (18) extending from the tool holder (4) to the passage (10) is formed in a staggered manner axially forwards from the passage (10).

9. Drill chuck (1) according to one of claims 5 to 8, characterized in that the diameter of the internal thread (16) of the passage (10) is larger than the diameter of a locking screw (19) extending through the passage.

10. Drill chuck (1) according to one of claims 1 to 9, in combination with a drilling machine having a drilling spindle (21), characterized in that the drilling spindle (21) has, at its end axially facing the drill chuck (1), an engagement section (26) with a non-circular second outer circumference (27), the shape of which corresponds to that of the first outer circumference (12).

11. Drill chuck (1) according to claim 10, characterized in that the drill spindle (21) has a spindle pin (29) with a pin diameter matched to the fitting receptacle (9) from the engagement section (26) axially towards its free end for guidance in the fitting receptacle (9).

12. Drill chuck (1) according to one of claims 5 to 11, characterized in that a forcing screw (17) is provided with an outer diameter matched to the diameter of the internal thread (16) of the passage (10).

13. Drilling machine with a drilling spindle (21 ), characterized in that the drilling spindle (21 ) has at its end axially facing the drill chuck (1 ) an engagement section (26) with a non-circular second outer circumference (27) whose shape corresponds to that of the first outer circumference (12).

14. Drilling machine according to claim 13, characterized in that the drilling spindle (21) has a spindle pin (29) with a spindle diameter matched to the fitting receptacle (9) from the engagement section (26) axially toward its free end for guiding in the fitting receptacle (9).

15. Drilling machine according to claim 13 or 14, characterized in that the end face of the engagement section facing axially toward the free end of the drilling spindle (21) is designed as a first flat surface (22).

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