Expansion Clamping Sleeve and Hydraulic Expansion Clamping Chuck

Abstract

The invention relates to an expansion clamping sleeve (6) comprising a sleeve body (30) having a tool receptacle (24) for a chipping tool, wherein the sleeve body (30) is expanded in a longitudinal direction (10) as well as in a radial direction (20) transverse to the longitudinal direction (10), wherein the sleeve body (30) comprises a pressure membrane (44) delimiting a hydraulic chamber (40) in the sleeve body (30), and wherein the sleeve body (30) comprises a receptacle (46) for a mechanical actuator (48) for activating the pressure membrane (44). In addition, the invention relates to a hydraulic expansion clamping chuck (2) having such an expansion clamping sleeve (6).

Claims

1. An expansion clamping sleeve comprising a sleeve body having a tool receptacle for a chipping tool, wherein the sleeve body is expanded in a longitudinal direction as well as in a radial direction transverse to the longitudinal direction, wherein the sleeve body comprises a pressure membrane delimiting a hydraulic chamber in the sleeve body, and wherein the sleeve body comprises a receptacle for a mechanical actuator for activating the pressure membrane.

2. The expansion clamping sleeve according to claim 1, wherein the sleeve body is designed as a monolithic sleeve body, and wherein the monolithic sleeve body forms the pressure membrane.

3. The expansion clamping sleeve according to claim 1, wherein the sleeve body forms the hydraulic chamber as well as a clearance, and wherein the pressure membrane separates the hydraulic chamber and the clearance from one another.

4. The expansion clamping sleeve according to claim 1, wherein the receptacle is designed as a tapped hole for an adjustment screw as the actuator.

5. The expansion clamping sleeve according to claim 3, wherein the pressure membrane comprises a reinforced wall region as an abutment for the actuator.

6. The expansion clamping sleeve according to claim 1, wherein the sleeve body forms an inner wall and an outer wall, wherein the inner wall forms the tool receptacle, wherein the hydraulic chamber is formed between the inner wall and the outer wall, and wherein the outer wall comprises the clearance and thereby forms the pressure membrane.

7. The expansion clamping sleeve according to claim 1, wherein the sleeve body comprises at least one filling opening for filling the hydraulic chamber.

8. The expansion clamping sleeve according to claim 1, wherein a hydraulic interface for connecting hydraulic chamber to an external hydraulics is omitted.

9. The expansion clamping sleeve according to claim 1, wherein the sleeve body forms a flange having a number of holes for screwing the sleeve body to a carrier unit.

10. A hydraulic expansion clamping chuck comprising an expansion clamping sleeve according to claim 1.

11. The hydraulic expansion clamping chuck according to claim 10, wherein it comprises a carrier unit with a receptacle for the expansion clamping sleeve, and wherein the carrier unit is designed for a reversibly releasable connection to the expansion clamping sleeve.

12. The hydraulic expansion clamping chuck according to claim 11, wherein the carrier unit comprises on an end face a number of tapped holes for forming a screw connection between the expansion clamping sleeve and the carrier unit.

13. The hydraulic expansion clamping chuck according to claim 11, wherein the carrier unit comprises on an end face a screw thread for screwing on a locking ring for fixing the expansion clamping sleeve in the receptacle of the carrier unit.

14. The hydraulic expansion clamping chuck according to claim 10, wherein the carrier unit comprises an opening for the actuator.

15. The hydraulic expansion clamping chuck according to claim 10, wherein the carrier unit comprises a filling opening for filling the hydraulic chamber of the expansion clamping sleeve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Exemplary designs of the invention are explained in further detail in the following on the basis of a schematic drawing. The following are shown:

[0042] FIG. 1 in a first longitudinal section, a first design of a hydraulic expansion clamping chuck,

[0043] FIG. 2 in a first cross-section, the first design of the hydraulic expansion clamping chuck,

[0044] FIG. 3 in a second longitudinal section, a second design of the hydraulic expansion clamping chuck,

[0045] FIG. 4 in a second cross-section, the second design of the hydraulic expansion clamping chuck, and

[0046] FIG. 5 in a third longitudinal section, a portion of the second design of the hydraulic expansion clamping chuck.

[0047] Parts corresponding to one another bear the same reference numerals in the figures.

DETAILED DESCRIPTION

[0048] A hydraulic expansion clamping chuck 2, described hereinafter by way of example, comprises a carrier unit 4 and an expansion clamping sleeve 6 mounted in the carrier unit 4. The expansion clamping sleeve 6 is reversibly releasably connected to the carrier unit 4 and thereby can be simply replaced. FIG. 1 shows a longitudinal section through the hydraulic expansion clamping chuck 2. A central longitudinal axis 8 lies in the cutting plane.

[0049] The carrier unit 4 is expanded around this central longitudinal axis 8 and extends in a longitudinal direction 10 along the central longitudinal axis 8 from a first end to a second end. The first end, shown on the left in FIG. 1, forms a receptacle 12 for the expansion clamping sleeve 6, and the second end, shown on the right in FIG. 1, forms a machine interface 14, which, in the exemplary design, is designed as a hollow shaft cone interface (HSC interface, briefly HSC).

[0050] The receptacle 12 is formed substantially symmetrically around the central longitudinal axis 8 and has at least approximately a cylindrical shape. The expansion clamping sleeve 6 is inserted in the receptacle 12, and a locking ring 16 is screwed into an end-side opening of the receptacle 12, which locks the opening and fixes the expansion clamping sleeve 6 in the receptacle 12.

[0051] The locking ring 16 has an outer diameter 18 that is larger than the diameter of the receptacle 12. That is to say, the expansion of the locking ring 16 in a radial direction 20 transverse to the longitudinal direction 10 is greater than the expansion of the receptacle 12 in the radial direction 20. The inner diameter 22 of the locking ring 16 has an expansion in the radial direction 20, which corresponds approximately to the expansion of a tool receptacle 26 of the expansion clamping sleeve 6. In FIG. 1, a tool access 26 in the locking ring 16 is also indicated, which facilitates the screwing of the locking ring 16 into a screw thread 28 on the carrier unit 4.

[0052] The expansion clamping sleeve 6 comprises a sleeve body 30, which, according to FIG. 1, is arranged countersunk in the receptacle 12 of the carrier unit 4. For easier assembly, a positioning pin 32 is formed on the sleeve body 30, and a recess 34 is formed in the carrier unit 4. The sleeve body 30 can thus only be inserted into the receptacle 12 in a predetermined rotational position.

[0053] In the exemplary design, the sleeve body 30 is designed as a monolithic sleeve body 30 and consists of a metal or metal alloy. Preferably, the sleeve body 30 is manufactured by means of a 3D printing process, for example by means of a so-called direct metal laser sintering (DMLS), by means of a so-called direct additive laser construction (CLAD), or by means of a so-called filament-metal printing (FFF method/FDM method).

[0054] The sleeve body 30 comprises the aforementioned tool receptacle 24 for receiving a shaft (not shown) of a rotatable chipping tool, such as a milling tool, a drill, or a reamer. According to FIG. 1, the sleeve body 30 further extends in the longitudinal direction 10 on the one hand and in the radial direction 20 on the other hand, wherein the sleeve body 30 is elongated in the longitudinal direction 10, for example, depending on the design variant. The tool receptacle 24 is formed around the central longitudinal axis 8 and has a cylindrical geometry at least in a home position as shown in FIG. 1.

[0055] The sleeve body 30 forms an inner wall 36 and an outer wall 38, wherein the inner wall 36 forms the tool receptacle 24, wherein the hydraulic chamber 40 is formed between the inner wall 36 and the outer wall 38, and wherein the outer wall 38 comprises a clearance 42 and thereby forms the pressure membrane 44. The inner wall 36 separates the tool receptacle 24 from the hydraulic chamber 40, and the outer wall 38 separates the hydraulic chamber 40 from the surrounding environment.

[0056] In addition, the sleeve body 30 forms a receptacle 46 for a mechanical actuator, which, in the exemplary design, is formed by a grub screw 48. The receptacle 46 is formed by a tapped hole, which extends in the radial direction 20. The grub screw 48 serves to activate the pressure membrane 44, which is typically designed so as to be flexible.

[0057] The expansion clamping sleeve 6 is thus designed so as to convert a mechanical force exerted by the grub screw 48 via the pressure membrane 44 into a hydraulic pressure in the hydraulic chamber 40 and to provide a reversible deformation of the tool receptacle 24 via the hydraulic pressure in the hydraulic chamber 40. The sleeve body 30 is thus suitably designed such that the volume of the tool receptacle 24 is reduced by the reversible deformation of the tool receptacle 24.

[0058] According to FIG. 1, the pressure membrane 44 comprises a reinforced wall region as an abutment 50 or as a tool access for the actuator, i.e., the grub screw 48. In addition, a design in which the reinforced wall region is positioned approximately centrally when viewed in the longitudinal direction 10 with respect to the expansion of the pressure membrane 44, as shown in FIG. 1, is expedient in this case. In addition, it is expedient when the expansion of the reinforced wall region is adapted to the dimensions of the actuator, i.e., in this case to the diameter of the grub screw 48.

[0059] FIG. 1 further shows a design of the inner wall 36 in which three portions are formed when viewed in the longitudinal direction 10. A central portion 52 has a greater wall thickness than the two outer portions 54 that adjoin the central portion 52.

[0060] Furthermore, the hydraulic chamber 40 preferably extends over at least 40% of the expansion of the sleeve body 30 in the longitudinal direction 10, further preferably over at least 50%. In addition, in the exemplary design, the hydraulic chamber 40 has a geometry that well approximates a hollow cylinder.

[0061] The clearance 42, in turn, preferably extends in the longitudinal direction 10 over a length that is greater than or equal to 20% of the expansion of the sleeve body 30 in the longitudinal direction 10, further preferably greater than or equal to 30%. The geometry of the clearance 42 well approximates a hollow cylinder segment, which is arranged concentrically to the central longitudinal axis 8. The clearance 42 typically extends over an angular range of less than or equal to 180 about the central longitudinal axis 8, further preferably less than or equal to 120. This can be seen in FIG. 2. FIG. 2 shows a cross-section transverse to the longitudinal section according to FIG. 1. The position of the cross-section is indicated by the intersecting line 56 in FIG. 1.

[0062] To fill the hydraulic chamber 40, the sleeve body 30 further comprises a filling opening 58. The filling opening 58 is designed as a tapped hole. Furthermore, a connecting passage 60 adjoins the filling opening 58 and connects the filling opening 58 to the hydraulic chamber 40. In the exemplary design, the filling opening 58 is closed by a ball seal 62 held by a grub screw 64.

[0063] A second filling opening 66 for filling the hydraulic chamber 40 comprises the carrier unit 4. The second filling opening 66 is in turn designed as a tapped hole and is closed by a ball seal 62, which is held by a grub screw 64. A hydraulic passage 68 further adjoins the second filling opening 66 and connects the filling opening 66 to a hydraulic interface 70. In the exemplary design, the hydraulic interface 70 connects the hydraulic passage 68 of the carrier unit 4 to a hydraulic interface 72 of the expansion clamping sleeve 6, which in turn is connected to the hydraulic chamber 40.

[0064] In this design variant of the hydraulic expansion clamping chuck 2, the filling with a hydraulic fluid takes place with the expansion clamping sleeve 6 mounted. The expansion clamping rate can then be optionally adjusted via each of the two filling openings 58, 66.

[0065] An alternative design of the hydraulic expansion clamping chuck 2 is shown in FIG. 3 to FIG. 5. Here, the carrier unit 4 does not have a filling opening 66, and no hydraulic interface 70, 72 is formed between the carrier unit 4 and the expansion clamping sleeve 6.

[0066] Instead, the expansion clamping sleeve 6 itself comprises a second filling opening 74 for filling the hydraulic chamber 40, which is designed analogously to the first filling opening 58. That is to say, the second filling opening 74 is designed as a tapped hole and is closed by a ball seal 62, which is held by a grub screw 64. In this design variant of the hydraulic expansion clamping chuck 2, the filling takes place prior to the assembly of the expansion clamping sleeve 6. However, the expansion clamping rate can also be adjusted after assembly of the expansion clamping sleeve 6, namely via the filling opening 58. An access opening 76 is designed on the carrier unit 4 for this purpose, which allows access to the filling opening 58 from the outside after the assembly of the expansion clamping sleeve 6. A further access opening 78 on the carrier unit 4 allows for an external access to the grub screw 48, i.e., the actuator for the pressure membrane 44. No access opening is provided for the filling opening 74 in the exemplary design.

[0067] A further difference is that the expansion clamping sleeve 6 is not retained by a locking ring 16 in the case of the design variant according to FIG. 3 to FIG. 5. Instead, the expansion clamping sleeve 6 forms a flange 80 that is screwed to the carrier unit 4. In the assembled state, screws 82 then penetrate holes in the flange 80 and are screwed into tapped holes of the carrier unit 4. This is shown in FIG. 5. FIG. 5 shows a portion of a longitudinal section that traverses the axis 84 in FIG. 4. FIG. 4, in turn, shows a front view of the alternative design of the hydraulic expansion.