Drill chuck and drill

Abstract

The invention relates to a drill chuck (1) with a chuck body (2) which, at its rear end, has a spindle receptacle (3) and, at its axially front end, has a tool receptacle (4), into which clamping jaws (6), which are displaceably guided in guide channels (5) of the chuck body (2), open. Extending forwards in the axial direction from the axially rear end of the spindle receptacle (3) is at least one groove (8), which is oriented radially with respect to the longitudinal axis (7) of the chuck body (2), wherein a mating receptacle (9) is formed staggered axially forwards from the groove (8), and a passage (10) reaches from the mating receptacle (9) into the tool receptacle (4). The invention further 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 forward end, into which clamping jaws movably guided in guide channels of the chuck body open. At least one groove oriented radially to the longitudinal axis of the chuck body extends axially forward from the axially rear end of the spindle receptacle. A fitting receptacle is formed staggered axially forward from the groove, and a passage extends from the fitting receptacle to the tool receptacle. 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, at the same time, 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 14. 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 drilling machine. Instead of the widely used screw connection between the drill spindle and the drill chuck, which is responsible for power transmission, the radial forces are now introduced into the chuck body via the groove, and the alignment of the spindle in the spindle mount is achieved via the fitting mount, thus simplifying axial securing. The groove does not have to extend radially to the outer edge of the chuck body, but can also be formed like a pocket. The inventive design enables torques greater than 200 Nm to be transmitted. The axial securing of the spindle can be achieved by a locking screw that extends from the tool holder through the passage to the spindle mount, where it can be screwed into a screw recess formed in the spindle.

[0009] It is advantageous if the groove is provided multiple times in an evenly distributed arrangement around the circumference, especially if the groove is formed twice in a diametrically opposed, radially aligned arrangement. This enables symmetrical torque transmission without any tilting moments, with the simplest possible design.

[0010] It is particularly preferred if the transition from the groove walls to the groove base is formed with a rounded portion. This rounded portion provides an enlarged surface area for contact between the spindle mount and the spindle to be inserted there, which is associated with reduced surface pressure and thus promotes the transmission of higher forces in the small available installation space. To increase the surface area and thus reduce surface pressure, the groove base has a radius, or is formed with a radius, that is between 25 mm and 55 mm and preferably has a radius of 40 mm.

[0011] If the radial extension of the groove is greater than the radial extension of the fit holder, the torque can be transmitted with a large lever, while still allowing the spindle to be guided centrally and centrally past the groove. The diameter of the fit holder is preferably 12 mm, as this allows for sufficient remaining material thickness of the chuck body in that area while maintaining a good remaining thickness of the spindle.

[0012] The diameter of the passage is smaller than the diameter of the fitting holder, so that the fitting holder can also act as a stop, especially if there is an internal thread in the passage. This internal thread is not used to interact with and secure the spindle relative to the chuck body, but rather enables the spindle to be pushed out of the spindle holder using a forcing screw, which is particularly advantageous when corrosion can 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 present.Especially during grinding operations, considerable additional effort is avoided because the use of the locking screw with its assembly and disassembly is no longer necessary.

[0013] If a countersink extending from the tool holder to the passage is formed in a staggered manner axially from 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.

[0014] Again, to increase the available surface and thus reduce the surface pressure, the transition from the outer surface of the chuck body in the area of ​​the axially rear end of the spindle holder to a body disc forming parts of the guide channels is designed with a disc rounding.

[0015] The diameter of the internal thread of the passage is larger than the diameter of the locking screw passing through the passage, so that the locking screw can be guided past the internal thread without interference when screwing into the spindle.

[0016] It is particularly preferred if, in a drilling machine with a drilling spindle, a radially projecting wing is formed at a distance from the free end of the drilling spindle, wherein the wing is present in duplicate in a diametrically opposed arrangement and the end face of the free end of the drilling spindle is designed as a flat surface. This enables the formation of a combination of a drill chuck of the aforementioned type with a drilling machine of this type having a drilling spindle, wherein the drilling spindle has at least one radially projecting wing intended for insertion into the at least one groove, and the drilling spindle has a spindle diameter matched to the wing for guidance in the fitting diameter.

[0017] 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.

[0018] 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.

[0019] Further advantages, features, and details of the invention will become apparent from the claims, the following description of preferred embodiments, and the drawings. Herein:

[0020] Figure 1 is a side view of a drill chuck, partially sectioned,

[0021] Figure 2 is an enlarged view of the detail concerning the body collar in the area of ​​the driving groove from Figure 1, Figure 3 is a view of the drill chuck corresponding to Figure 1 in combination with a spindle secured by a locking screw,

[0022] Figure 4 shows a representation corresponding to Figure 3 of the combination of the drill chuck with a grinding spindle, and

[0023] Figure 5 is a representation corresponding to Figure 1 of the combination of the drill chuck with a drill spindle of a drilling machine, shown with a forcing screw attached.

[0024] 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. Extending axially forward from the axially rear end of the spindle holder 3, at least one groove 8 oriented radially to the longitudinal axis 7 of the chuck body 2 extends. The groove 8 can be provided multiple times in an arrangement evenly distributed over the circumference. In the exemplary embodiments shown, the groove 8 is formed twice in a diametrically opposed, radially aligned arrangement.

[0025] A fitting receptacle 9 is formed staggered axially forwards from the groove 8, with a passage 10 extending from the fitting receptacle 9 to the tool holder 4.

[0026] Figure 2 shows that the transition from the groove walls 11 to the groove base 12 is formed with a rounded portion 13, which serves to minimize the notch effect acting in the groove 8. The groove base 12 itself is also rounded, with a radius 25, which in the embodiment shown in the drawing is 40 mm. This radius 25 serves to enlarge the surface in order to reduce the surface pressure. The radius 25 shown of 40 mm is particularly suitable, although the radius 25 can also assume values ​​between 25 mm and 55 mm, in particular between 35 mm and 45 mm. Reduced surface pressure is also the motivation for the transition from the outer surface of the chuck body 2 in the region of the axially rearward end of the spindle holder 3 to a body disk forming parts of the guide channels 5 being formed with a disk rounded portion 15.

[0027] The radial extension of the groove 8 is greater than the radial extension of the fitting receptacle 9 to allow insertion of the spindle 14 into the fitting receptacle 9 while ensuring improved torque transmission. The diameter of the fitting receptacle 9 is 12 mm in the embodiment shown in Figure 1.

[0028] The diameter of the passage 10 is smaller than the diameter of the fitting receptacle 9, thus also providing a stop for the front side of the spindle 14. An internal thread 16 is formed in the passage 10, which can be used to interact with a forcing screw 17, which is provided with an outer diameter matched to the diameter of the internal thread 16 of the passage 10. The forcing screw 17 thus allows the spindle 14 to be pressed axially out of the spindle receptacle 3 as needed, for example, to change the drill chuck. Furthermore, the internal thread 16 can also be used for assembly and machining purposes with regard to the drill chuck 1.

[0029] From the passage 10, a countersink 18 is formed, staggered axially forward, extending from the tool holder to the passage, which serves to receive the screw head of a locking screw (Figure 1).

[0030] The diameter of the internal thread 16 of the passage 10 is larger than the diameter of the locking screw 19 extending through the passage 10. In order to provide a drill suitable for interaction with such a drill chuck 1, a drill with a drill spindle 21 has at least one radially projecting wing spaced from the free end of the drill spindle 21. Preferably, the wing is provided in duplicate in a diametrically opposed arrangement in the embodiments shown. The end face of the free end of the drill spindle 21 is designed as a flat surface 22.

[0031] This allows a combination of the drill chuck 1 with a drilling machine having a drilling spindle 21 to be formed, wherein the drilling spindle has at least one radially projecting wing intended for insertion into the at least one groove 8 and for guidance in the fitting receptacle 9 and a spindle diameter matched thereto.

[0032] Figure 3 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 flat surface 22 of the spindle 14 against the chuck body in the area of ​​the fitting mount 9, thus fixing the axial position. The radial position of the spindle 14 is determined by the fitting mount 9. Figure 4 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.

[0033] 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 can be pressed axially out of the spindle holder 3 (Figure 5). LIST OF REFERENCE SYMBOLS.

[0034] 1 drill chuck

[0035] 2 chuck bodies

[0036] 3 spindle holder

[0037] 4 tool holder

[0038] 5 guide channel

[0039] 6 clamping jaws

[0040] 7 Longitudinal axis

[0041] 8 grooves

[0042] 9 Fitting recording

[0043] 10 rounds

[0044] 11 Groove wall

[0045] 12 Groove base

[0046] 13 Rounding

[0047] 14 spindle

[0048] 15 Disc rounding

[0049] 16 internal threads

[0050] 17 Forcing screw

[0051] 18 Reduction

[0052] 19 Locking screw

[0053] 20 screw head

[0054] 21 Drill spindle

[0055] 22 Plan area

[0056] 23 Grinding spindle

[0057] 24 Body disc

[0058] 25 radius

Claims

CLAIMS:

1. Drill chuck (1) with a chuck body (2) which has a spindle receptacle (3) at its rear end and a tool receptacle (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 at least one groove (8) oriented radially to the longitudinal axis (7) of the chuck body (2) extends from the axially rear end of the spindle receptacle (3) in the axial direction towards the front, that a fitting receptacle (9) is formed which is staggered axially towards the front from the groove (8), and that a passage (10) extends from the fitting receptacle (9) to the tool receptacle (4).

2. Drill chuck (1) according to claim 1, characterized in that the groove (8) is provided several times in an arrangement distributed uniformly over the circumference.

3. Drill chuck (1) according to claim 2, characterized in that the groove (8) is formed twice in a diametrically opposite, radially aligned arrangement.

4. Drill chuck (1) according to one of claims 1 to 3, characterized in that the transition from the groove walls (11) to the groove base (12) is formed with a rounding (13).

5. Drill chuck (1) according to one of claims 1 to 4, characterized in that the groove base (12) is formed with a radius (25).

6. Drill chuck (1) according to one of claims 1 to 5, characterized in that the radial extent of the groove (8) is greater than the radial extent of the fitting receptacle (9).

7. Drill chuck (1) according to one of claims 1 to 6, characterized in that the diameter of the fitting receptacle (9) is 12 mm.

8. Drill chuck (1) according to one of claims 1 to 7, characterized in that the diameter of the passage (10) is smaller than the diameter of the fitting receptacle (9).

9. Drill chuck (1) according to one of claims 1 to 8, characterized in that an internal thread (16) is formed in the passage (10).

10. Drill chuck (1) according to one of claims 1 to 9, 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).

11. Drill chuck (1) according to one of claims 1 to 10, characterized in that the transition from the outer surface of the chuck body (2) in the region of the axially rearward end of the spindle holder (3) to a body disc (24) forming parts of the guide channels (5) is formed with a disc rounding (15).

12. Drill chuck according to one of claims 9 to 11, characterized in that the diameter of the internal thread of the passage (10) is larger than the diameter of a locking screw (19) extending through the passage.

13. Drill chuck (1) according to one of claims 1 to 12, in combination with a drilling machine having a drilling spindle (21), characterized in that the drilling spindle (21) has at least one radially projecting wing intended for insertion into the at least one groove (8), and in that the drilling spindle (21) has a spindle diameter matched thereto for guidance in the fitting receptacle (9).

14. Drill chuck (1) according to one of claims 9 to 13, characterized in that a forcing screw (17) with a diameter of the internal thread (16) of the passage (10) is provided.

15. Drilling machine with a drilling spindle (21), characterized in that a radially projecting wing is formed at a distance from the free end of the drilling spindle (21).

16. Drilling machine according to claim 15, characterized in that the wing is present in two diametrically opposed arrangements, and that the front side of the free end of the drilling spindle (21) is designed as a flat surface (22).

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