Drill chuck and drill

Abstract

The invention relates to a 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) movably guided in guide channels (5) of the chuck body (2) open. At least one groove (8) oriented radially to the longitudinal axis (7) of the chuck body (2) extends axially forwards from the axially rear end of the spindle receptacle (3), wherein a fitting receptacle (9) is formed, staggered axially forwards from the groove (8), and a passage (10) extends from the fitting receptacle (9) to the tool receptacle (4). The invention further relates to a drilling machine.

Description

The invention relates to a drill chuck having a chuck body which has a spindle receptacle at its rear end and a tool receptacle at its axially front end, into which clamping jaws displaceably guided in guide channels of the chuck body open, wherein at least one groove oriented radially to the longitudinal axis of the chuck body extends from the axially rear end of the spindle receptacle in the axially forward direction, wherein a fitting receptacle is formed offset axially forward from the groove, and wherein a passage extends from the fitting receptacle to the tool receptacle. The invention further relates to a drilling machine.A drilling chuck is known from EP 0 710 518 A2, wherein with regard to the basic design and the mode of operation of the drilling chuck, reference can be made to this publication reflecting the knowledge of the person skilled in the art. DE 20 2013 101 255 U1 discloses a drilling chuck with a chuck body, at the rear end of which a spindle receptacle is formed for coupling to the drilling spindle of a drilling machine, said spindle receptacle having an internal thread into which the drilling spindle can be screwed with an external thread. The axial securing of the drill chuck with respect to the drill spindle is served by a passage formed in the chuck body, through which a securing screw can be screwed into a screw receptacle of the drill spindle.Modern drilling machines are becoming increasingly powerful and can generate high torques greater than 200 Nm, which must be transmitted reliably to the drill chuck without overloading the connection between the chuck body and the drilling spindle or jeopardizing later releasability, i.e. also enabling a drill chuck change. In particular, it must be ensured that no breakage of the drilling spindle occurs, since this could jeopardize the user if the drill chuck separates from the drilling machine during operation. An increase in the material thickness is not an easily movable path because the outer diameter of the drill chuck should not exceed the value of 43 mm, since this value is accepted in industry and the dimensions are matched to this.It is therefore the object of the present invention to provide a drill chuck by means of which a high torque can be transmitted and at the same time also enables the user to change the drill chuck from a drill spindle without the need to visit a service center. It is a further object to provide a drilling machine suitable for driving the drill chuck.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 developments of the invention are specified in the dependent claims.The aforementioned chuck enables an improved transmission of force from the drilling spindle of a drilling machine, since instead of the widely used screw connection between the drilling spindle and the chuck, which is responsible for the transmission of force, the radial forces are now introduced into the chuck body via the groove and the alignment of the spindle in the spindle receptacle is effected via the mating receptacle, whereby the axial securing is simplified. The groove does not have to extend radially as far as the outer edge of the chuck body, but can also be formed in the manner of a pocket. The configuration according to the invention enables torques which are greater than 200 Nm to be transmitted. The axial securing of the spindle can be effected by a securing screw which extends from the tool holder through the passage to the spindle holder and can be screwed there into a screw receptacle formed in the spindle. It is advantageous here if the groove is provided multiple times in an arrangement distributed uniformly over the circumference, in particular if the groove is formed twice in a diametrically opposite, radially oriented arrangement. This enables a symmetrical torque transmission without acting tilting torques, with a design that is as simple as possible.It is particularly preferred in this case if the transition from the groove walls to the groove base is formed with a rounded portion. This rounding provides an enlarged area for the contact between the spindle receptacle and the spindle to be inserted there, which is associated with a reduced surface pressure and thus promotes the transmission of higher forces in the available small installation space. To increase the surface area and thus reduce the surface pressure, the groove base has a radius or is formed with a radius which is between 25 mm and 55 mm and preferably has 40 mm.If the radial extension of the groove is greater than the radial extension of the fitting receptacle, then the torque can be transmitted with a large lever and the spindle can nevertheless be guided with its spindle axis centrally and centrally past the groove. The diameter of the fitting receptacle is preferably 12 mm, since this enables a sufficient remaining material thickness of the chuck body in the region with 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, in particular if an internal thread is formed in the passage. This internal thread does not serve for the cooperation and securing of the spindle relative to the chuck body, but on the one hand allows the spindle to be pressed out of the spindle receptacle with a push-off screw, which is advantageous in particular if corrosion can occur in the region of the interface between the spindle and the chuck body under climatically poor conditions. On the other hand, this internal thread can be used for the assembly and machining of the drill chuck, since the thread used otherwise for these purposes and serving to secure the spindle is not present. Particularly in grinding operations, considerable additional expenditure is avoided because the use of the securing screw with its mounting and dismantling is unnecessary.If a counterbore is formed, staggered axially forward from the passage, extending from the tool holder to the passage, the screw head of the securing screw can be introduced there without disturbing the tools or workpieces to be introduced into the tool holder.Again, in order to increase the available surface and thus reduce the surface pressure, the transition from the outer surface of the chuck body in the region of the axially rearward end of the spindle receptacle to a body disk forming parts of the guide channels is formed with a disk fillet.The diameter of the internal thread of the passage is larger than the diameter of the securing screw passing through the passage, so that the securing screw can be guided undisturbed by the internal thread past the latter when it is screwed into the spindle.It is very particularly preferred if, in a drilling machine with a drilling spindle, a radially protruding wing is formed at a distance from the free end of the drilling spindle, wherein the wing is present twice in a diametrically opposite arrangement and the end face of the free end of the drilling spindle is designed as a planar surface.This enables the formation of a combination of a drill chuck of the above-mentioned type with such a drilling machine having a drilling spindle, wherein the drilling spindle has at least one radially protruding wing intended for insertion into the at least one groove and the drilling spindle has a spindle diameter adapted thereto for guidance in the mating diameter.In addition, a jacking screw can be provided with an outer diameter matched to the diameter of the internal thread of the passage, by means of which the drilling spindle of the drilling machine is pressed out of the spindle receptacle when the jacking screw is screwed into the internal thread.The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figure can be used not only in the respectively specified combination but also in other combinations or alone without departing from the scope of the invention. Therefore, embodiments are also to be considered included and disclosed by the invention which are not explicitly shown or explained in the figure, but which emerge from the explained embodiments and can be generated by separate combinations of features.Further advantages, features and details of the invention are evident from the claims, the following description of preferred embodiments, and with reference to the drawings. The following shows: FIG. 1 is a side view of a drill chuck, shown partially in section, FIG. 2 shows an enlarged representation of the detail relating to the body collar in the region of the entrainment groove from FIG. 1, FIG. 3 is a view corresponding to FIG. 1 of the drill chuck in combination with a spindle secured by a securing screw, FIG. 4 is a view corresponding to FIG. 3 of the combination of the drill chuck with a grinding spindle; and FIG. 5 is a view corresponding to FIG. 1 of the combination of the chuck with a drilling spindle of a drilling machine, shown with a pressure screw attached.FIG. 1 shows a 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 displaceably guided in guide channels 5 of the chuck body 2 open. From the axially rearward end of the spindle receptacle 3 extends in the axial direction forward at least one groove 8 oriented radially to the longitudinal axis 7 of the chuck body 2. The groove 8 can be provided several times in an arrangement distributed uniformly over the circumference. In the exemplary embodiments shown, the groove 8 is formed twice in a diametrically opposite, radially oriented arrangement.Staggered axially forward of the groove 8 is a fitting receptacle 9, with a passage 10 extending from the fitting receptacle 9 to the tool receptacle 4.FIG. 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 which acts in the groove 8. The groove base 12 itself is also rounded, with a radius 25 which, in the exemplary embodiment shown in the drawing, is 40 mm. This radius 25 serves to increase the area to reduce the surface pressure. The radius 25 of 40 mm shown is particularly well suited here, although the radius 25 can also assume values between 25 mm and 55 mm, in particular between 35 mm and 45 mm. A reduced surface pressure is also the motif for the transition from the outer surface of the chuck body 2 in the region of the axially rearward end of the spindle receptacle 3 to a body disk forming parts of the guide channels 5 being formed with a disk fillet 15.The radial extension of the groove 8 is greater than the radial extension of the fitting receptacle 9 in order to allow the spindle 14 to be inserted into the fitting receptacle 9 and nevertheless to ensure improved torque transmission. The diameter of the fitting receptacle 9 is 12 mm in the exemplary embodiment shown in FIG. 1.The diameter of the passage 10 is smaller than the diameter of the fitting receptacle 9, so that a stop for the end face of the spindle 14 is also provided. The passage 10 has formed therein an internal thread 16 which can be used for cooperation with a jacking screw 17 provided with an external diameter matched to the diameter of the internal thread 16 of the passage 10. The spindle 14 can thus be pushed axially out of the spindle receptacle 3 as required by the push screw 17, for example for changing the drill chuck. Furthermore, the internal thread 16 can also be used for assembly and machining purposes with respect to the drill chuck 1.From the passage 10, a counterbore 18 is formed in a axially forwardly staggered manner, which counterbore extends from the tool holder to the passage and serves to receive the screw head of a locking screw (FIG. 1 ).The diameter of the internal thread 16 of the passage 10 is larger than the diameter of the securing screw 19 passing through the passage 10.In order to provide a drilling machine suitable for cooperation with such a chuck 1, a drilling machine having a drilling spindle 21 spaced from the free end of the drilling spindle 21 comprises at least one radially projecting wing, which wing is preferably provided twice in diametrically opposed relation with respect to the embodiments shown. The end face of the free end of the drilling spindle 21 is designed as a planar surface 22.As a result, a combination of the drill chuck 1 with a drilling machine having a drilling spindle 21 can be formed, wherein the drilling spindle has at least one radially protruding wing which is intended for insertion into the at least one groove 8 and a spindle diameter which is matched thereto for guidance in the fitting receptacle 9.FIG. 3 shows how the spindle holder 3 is used for connection to a spindle 14, which is shown in isolation, but can be formed as a drilling spindle 21 part of a drilling machine or as a grinding spindle 23. For the axial securing of the spindle 14 in the spindle receptacle 3, the securing screw 19 is used, which engages with its screw head 20 in the counterbore 18 and is arranged there. The flat surface 22 of the spindle 14 is pulled by the securing screw 19 against the chuck body in the region of the fitting receptacle 9 and the axial position is thus fixed. The radial position of the spindle 14 is determined by the fitting receptacle 9. FIG. 4 shows the possibility that for lower stress, as in the placement of a grinding spindle 23 in the spindle receptacle 3, the passage 10 with its internal thread 16 can also be used to secure the grinding spindle 23, i.e. no securing screw 19 then has to be mounted and disassembled.After removal of the securing screw 19, access to the passage 10 with the internal thread 16 is exposed. By means of a push-off screw 17 screwed into the internal thread 16, the drilling spindle 21 can be pushed axially out of the spindle receptacle 3 (FIG. 5 ).LIST OF REFERENCE CHARACTERS:1 Drill chuck 2 chuck body 3 spindle receptacle 4 tool receptacle 5 guide channel 6 clamping jaws 7 longitudinal axis 8 groove 9 fitting receptacle 10 passage 11 groove wall 12 groove base 13 rounded portion 14 spindle 15 disk rounded portion 16 internal thread 17 pressure screw 18 counterbore 19 securing screw 20 screw head 21 drill spindle 22 planar surface 23 grinding spindle 24 body disk 25 radiusReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 0 710 518 A2

[0002] DE 20 2013 101 255 U1

[0002]

Claims

Drilling 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) 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) forwards, in that a fitting receptacle (9) is formed offset axially forwards from the groove (8), and in that a passage (10) extends from the fitting receptacle (9) to the tool receptacle (4).Drilling chuck (1) according to claim 1, characterised in that the groove (8) is provided several times in an arrangement distributed uniformly over the circumference.Drilling chuck (1) according to claim 2, characterised in that the groove (8) is formed twice in a diametrically opposite, radially oriented arrangement.Drilling chuck (1) according to one of claims 1 to 3, characterised in that the transition from the groove walls (11) to the groove base (12) is formed with a rounded portion (13).Drilling chuck (1) according to one of claims 1 to 4, characterised in that the groove base (12) is formed with a radius (25).Drilling chuck (1) according to one of claims 1 to 5, characterised in that the radial extension of the groove (8) is greater than the radial extension of the fitting receptacle (9).Drilling chuck (1) according to one of claims 1 to 6, characterised in that the diameter of the fitting receptacle (9) is 12 mm.Drilling chuck (1) according to one of claims 1 to 7, characterised in that the diameter of the passage (10) is smaller than the diameter of the fitting receptacle (9).Drilling chuck (1) according to one of claims 1 to 8, characterised in that an internal thread (16) is formed in the passage (10).Drilling chuck (1) according to one of claims 1 to 9, characterised in that a counterbore (18) extending from the tool holder (4) to the passage (10) is formed in a manner axially staggered forwards from the passage (10).Drilling chuck (1) according to one of claims 1 to 10, characterised in that the transition from the outer surface of the chuck body (2) in the region of the axially rear end of the spindle receptacle (3) to a body disc (24) forming parts of the guide channels (5) is formed with a disc rounded portion (15).Drilling chuck according to one of claims 9 to 11, characterised in that the diameter of the internal thread of the passage (10) is greater than the diameter of a securing screw (19) extending through the passage.Drilling chuck (1) according to one of claims 1 to 12, in combination with a drilling machine having a drilling spindle (21), characterised in that the drilling spindle (21) has at least one radially protruding wing intended for insertion into the at least one groove (8), and in that the drilling spindle (21) has a spindle diameter adapted thereto for guidance in the fitting receptacle (9).Drilling chuck (1) according to one of claims 9 to 13, characterised in that a squeeze screw (17) is provided with an outer diameter which is matched to the diameter of the internal thread (16) of the passage (10).Drilling machine with a drilling spindle (21), characterised in that a radially protruding wing is formed at a distance from the free end of the drilling spindle (21).Drilling machine according to claim 15, characterised in that the wing is provided twice in diametrically opposite arrangement, and that the end face of the free end of the drilling spindle (21) is designed as a planar surface (22).

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