阅读说明：本技术 液压膨胀式卡盘及其使用 (Hydraulic expansion chuck and use thereof ) 是由 克劳斯·舍佩尔克特 斯特凡·贝克 米夏埃尔·迈尔 于 2019-02-28 设计创作，主要内容包括：本发明涉及一种用于夹紧工件(2)的液压膨胀式卡盘(1),所述液压膨胀式卡盘包括集成在其中用于接纳液压流体的至少一个通道(3),所述液压流体经提供以被加压从而压挤所述工件(2)使其被夹紧在所述液压膨胀式卡盘(1)中。所述液压膨胀式卡盘(1)通过增材制造工艺产生且为实质上环形,所述至少一个通道(3)具有至少一个环形圆周通道段(3a、3b),所述至少一个环形圆周通道段径向地形成在所述液压膨胀式卡盘(1)的内周表面(4)和外周表面(5)之间。根据本发明,所述液压膨胀式卡盘(1)在所述内圆周表面(4)上具有保持轮廓(6),所述保持轮廓包括多个膨胀凸耳(6a),其中多个另外的管道段(7)从所述至少一个管道(3)分支出来,其中至少一个另外的通道段(7)延伸到所述膨胀凸耳(6a)中的一个中。本发明还涉及这种液压式夹紧工具(1)的使用。(The invention relates to a hydraulic expansion chuck (1) for clamping a workpiece (2), comprising at least one channel (3) integrated therein for receiving a hydraulic fluid, which is provided to be pressurized in order to press the workpiece (2) so as to be clamped in the hydraulic expansion chuck (1). The hydraulic expansion chuck (1) is produced by an additive manufacturing process and is substantially annular, the at least one channel (3) having at least one annular circumferential channel section (3a, 3b) formed radially between an inner peripheral surface (4) and an outer peripheral surface (5) of the hydraulic expansion chuck (1). According to the invention, the hydraulic expansion chuck (1) has a retaining profile (6) on the inner circumferential surface (4), which comprises a plurality of expansion lugs (6a), wherein a plurality of further conduit sections (7) branch off from the at least one conduit (3), wherein at least one further channel section (7) extends into one of the expansion lugs (6 a). The invention also relates to the use of such a hydraulic clamping tool (1).)

1. Hydraulic expansion chuck (1) for clamping a workpiece (2), comprising at least one channel (3) integrated therein for receiving a hydraulic fluid, wherein the hydraulic fluid is intended to be pressurized in order to clamp the workpiece (2) in the hydraulic expansion chuck (1), wherein the hydraulic expansion chuck (1) is manufactured by an additive manufacturing process and is substantially ring-shaped, wherein the at least one channel (3) has at least one ring-shaped peripheral channel section (3a, 3b) formed radially between an inner circumferential surface (4) and an outer circumferential surface (5) of the hydraulic expansion tool (1), characterized in that the hydraulic expansion tool (1) has a holding profile (6) comprising a plurality of expansion lugs (6a) on the inner circumferential surface (4), and in that a plurality of further channel segments (7) branch off from the at least one channel (3), at least one further channel segment (7) extending into a respective one of the expansion lugs (6 a).

2. Hydraulic expansion chuck (1) according to claim 1,

characterized in that the hydraulic expansion chuck (1) is made of spring steel.

3. Hydraulic expansion chuck (1) according to any of the preceding claims,

characterized in that the retaining profile (6) has an approximately wave-like or sinusoidal shape, as seen in the direction of the axis of rotation (15) of the hydraulic clamping tool (1).

4. Hydraulic expansion chuck (1) according to any of the claims 1 to 3,

characterized in that the hydraulic expansion chuck (1) has two end faces (1a, 1b), each expansion lug (6a) extending between the two end faces (1a, 1b) with a constant lug height (H).

5. Hydraulic expansion chuck (1) according to any of the claims 1 to 4,

characterized in that each channel section (7) is approximately T-shaped in the direction of the axis of rotation (15) of the hydraulic clamping tool (1).

6. Hydraulic expansion chuck (1) according to any of the claims 1 to 5,

characterized in that each channel section (7) is T-shaped, seen in the longitudinal direction of the circumferential channel section (3a, 3 b).

7. Hydraulic expansion chuck (1) according to any of the preceding claims,

characterized in that the channel (3) and the channel segments (3a, 3b, 7) are filled with hydraulic fluid, a hydraulic cylinder (8) being fluidly connected to the at least one channel (3) and provided to introduce a pressure to the hydraulic fluid.

8. Hydraulic expansion chuck (1) according to any of the preceding claims,

characterized in that a venting cylinder (9) is fluidly connected to the at least one channel (3) and is provided to vent the at least one channel (3).

9. Hydraulic expansion chuck (1) according to any of the preceding claims,

characterized in that a plurality of receiving elements (10) are arranged at least partially movable on the retaining profile (6) and intended to be at least partially displaced against the workpiece (2) when clamping the workpiece (2).

10. Use of the hydraulic expansion chuck (1) according to any of the claims from 1 to 9 for clamping a workpiece (2) in the form of a gear or in the form of a component with external thread.

Technical Field

The present invention relates to a hydraulic expansion chuck for clamping a workpiece. The invention also relates to the use of such a hydraulic clamping tool. The field of application of the invention extends primarily to clamping tools for machining batches of parts from a prototype.

Background

Precise clamping tools are required to clamp the workpiece, such as manufacturing machining. The more accurate and reproducible the clamping tool holds the workpiece, the more efficient and effective the workpiece machining. The precision achievable on the finished part is determined primarily by the clamping precision of the clamping tool, essentially by the position between the workpiece and the clamping tool. Furthermore, the clamping process of the workpiece has a great influence on the cycle time or the settings and clamping forces of the machine operator. The potential for automation in machining mass production is great.

Hydraulic clamping tools are known in the prior art. Typically, hydraulically expanding clamping tools are complex brazing and/or welding configurations that have only simple, rotationally symmetric holding or clamping profiles. Hydraulic clamping tools (in particular hydraulic spindles) can be adapted to the workpiece to be clamped only to a limited extent, which is achieved, for example, by means of a clamping ring, which can increase the clamping diameter.

Disclosure of Invention

DE 19737215 a1 discloses a tool combination consisting essentially of a clamping tool for the lens and a dressing tool for the polishing tool, which are both fixed to a single workpiece spindle when combined to form a unit. The dressing tool and the support ring can be firmly connected to each other. The tool assembly also includes a hydraulic chuck.

DE 102016116164 a1 describes a tool component for machining turning operations, in particular a clamping tool holder. At least one hollow cavity is created in the tool component by an additive sintering manufacturing process, the at least one hollow cavity containing unsintered sintered powder. This is intended to produce a damping effect during operation of the tool component. When the tool component is designed for use in a chuck, at least one expansion chamber may be formed in the shank section of the tool component to form an expandable chuck. Each expansion chamber is arranged as an annular chamber concentric with the axis of rotation of the tool holder, wherein a plurality of expansion chambers are arranged along the axis of rotation. The tool part can be designed as a hydraulic chuck.

The object of the present invention is to further develop a hydraulic expansion chuck, which, on the one hand, is shortened in its manufacturing time and, on the other hand, is designed to be directed towards the workpiece and close to the profile. Furthermore, the use of hydraulic clamping tools is specified.

This object is achieved for a hydraulic expansion chuck for clamping a workpiece, comprising at least one channel integrated therein for receiving a hydraulic fluid, wherein the hydraulic fluid is provided to be pressurized for clamping the workpiece in the hydraulic expansion chuck, wherein the hydraulic expansion chuck is manufactured by an additive manufacturing process and is substantially ring-shaped, wherein the at least one channel has at least one ring-shaped peripheral channel section formed radially between an inner circumferential surface and an outer circumferential surface of the hydraulic expansion tool, the hydraulic expansion tool has a holding profile comprising a plurality of expansion lugs on the inner circumferential surface, and a plurality of further channel sections branch out from the at least one channel, the at least one further channel section extending into a respective one of the expansion lugs.

"additive manufacturing process" refers to a manufacturing process in which materials are added in layers to form a workpiece. This is in contrast to conventional subtractive manufacturing processes, such as milling, drilling and turning, in which a workpiece is produced by removing material. An accurate description of the various processes and procedures summarized under the term "additive manufacturing process" can be found in the guideline VDI 3404 (12 months 2009) referenced herein. Both plastic and metal can be manufactured into the exact shape of the workpiece by additive manufacturing processes (also known as generative manufacturing processes or 3D printing). The additive manufacturing of the hydraulic clamping tool can reduce the production time to the greatest extent and achieve geometrically complex structures and geometries of the hydraulic clamping tool, in particular production profiles which are close to the shape of the workpiece to be clamped.

The retaining profile provided according to the invention, which comprises a plurality of expansion lugs which are arranged on the inner circumferential surface of the hydraulic clamping tool, enables a workpiece having a structured side surface to be clamped in the region of this side surface. The arrangement and configuration of the expansion lobe can be adapted directly to the workpiece to be clamped, in particular a surface structure with visible elevations and/or depressions.

Therefore, clamping of workpieces in the form of gears or parts with external threads using the hydraulic clamping tool according to the invention has proven successful. The structured outer surface is formed by the teeth of the gears or threads of the component. However, it is advantageously possible to clamp the components to be clamped by means of the hydraulic clamping tool according to the invention, which components are non-circular, polygonal (with a circumference) or the like in the region of their side surfaces.

The hydraulic fluid which can be introduced into the at least one channel is an incompressible fluid and is used for transmitting energy, in particular for generating pressure. The hydraulic fluid is preferably oil.

The hydraulically expandable chuck is preferably made of spring steel. Spring steel is particularly suitable for elastically deforming a hydraulic clamping tool when clamping a workpiece. According to a preferred embodiment, the hydraulic expansion chuck is made of martensitic tool steel, in particular of the material X3NiCoMoTi 1895 (1.2709). This material is high-strength and, at the same time as cold and hot work, has a high tensile strength and a high yield strength, as well as good toughness. The working hardness was about 55 to 57 HRC.

The hydraulic expansion chuck is substantially annular, and the at least one channel has at least one circumferential channel section formed radially between an inner circumferential surface and an outer circumferential surface of the hydraulic expansion chuck. By "circumferential channel section" is understood to mean that at least one channel is at least partially circular or oval in the interior of the hydraulic clamping tool. The at least one channel is thus located spatially completely within the outer skin of the hydraulic clamping tool and extends between the two end faces and the inner and outer circumferential surfaces.

The hydraulic expansion chuck has a holding profile on the inner circumferential surface, wherein the holding profile is preferably at least partially adapted to the workpiece to be clamped. The holding contour serves for holding and clamping the workpiece and is designed for reproducibly and precisely clamping the workpiece. In particular, the retaining profile is designed substantially to correspond to the workpiece, so as to hold the workpiece substantially rigidly and non-rigidly.

The at least one channel has a plurality of (in particular, substantially axially formed) further channel segments which extend at least partially into the expansion lobe in the direction of the retaining profile. These (in particular, axially formed) further channel segments are fluidly connected to at least one circumferential channel segment and thus together form at least one channel. Preferably, additional channel segments may be formed between each further channel segment and at least one circumferential channel segment. The term "substantially axially formed channel sections" is understood to mean that these channel sections extend at least partially over the axial length of the hydraulic clamping tool. The substantially axially formed channel section is preferably parallel to the longitudinal axis of the hydraulic clamping tool, and in particular perpendicular to the at least one circumferential channel section.

According to the invention, the retaining profile comprises a plurality of expansion lugs which are provided so as to expand radially inwards and in both circumferential directions when clamping the workpiece in order to clamp the workpiece. The expansion lobe is preferably in the form of a tooth with a circular tooth tip, in particular a semi-cylindrical tooth tip, and preferably extends in the axial direction. Preferably, the expansion lugs and the cavities are alternately arranged in the circumferential direction on the inner circumferential surface of the hydraulically expandable clamping tool, and the workpiece to be clamped penetrates at least partially into the cavities and is clamped by the expansion lugs.

The holding contour has, in particular, an approximately wave-like or sinusoidal profile, when viewed in the direction of the axis of rotation of the hydraulic clamping tool. This makes it possible to clamp workpieces, for example in the form of gears, particularly effectively on all sides. Alternatively, it is also possible to have a retaining profile in which the expansion lugs are balloon-shaped, T-shaped or L-shaped.

The hydraulic expansion chuck preferably has two end faces, each expansion lug extending between the two end faces at a constant lug height. The lug height of the expansion lugs may also vary. The course of the lug height can also be designed in a wave-like manner, wherein further channel sections in the region of each maximum peak can extend into the expansion lug.

In the direction of the axis of rotation of the hydraulic clamping tool, each channel section is preferably approximately T-shaped. In particular, each channel section is T-shaped in a cross-sectional view in the longitudinal direction of the circumferential channel section. These embodiments allow for high expansion to occur in the region of the expansion lobe that abuts the workpiece during expansion of the workpiece.

When using a hydraulic clamping tool, the channels and channel sections are filled with hydraulic fluid, and the hydraulic cylinder is fluidly connected to at least one channel and is intended to introduce a pressure to the hydraulic fluid. In one embodiment, the hydraulic cylinder has a thread at least partially on the outer circumferential surface, which thread engages in a thread of the hydraulic clamping means, wherein the hydraulic cylinder is axially displaced by rotation of the hydraulic cylinder, thereby applying a pressure to the hydraulic fluid. Due to this pressure, the retaining profile is at least partially elastically deformed and thus clamps the workpiece.

Preferably, a breather cylinder is fluidly connected to the at least one passage and is provided to breather the at least one passage. It is advantageous to vent at least one of the passages to prevent unnecessary down time due to maintenance or replacement of hydraulic fluid.

According to a preferred embodiment, the plurality of receiving elements are arranged at least partially movable on the holding profile and intended to be at least partially displaced against the workpiece when clamping the workpiece.

Drawings

Further measures to improve the invention are shown below together with the description of three preferred embodiments of the invention with reference to the drawings. In the drawings, there is shown in the drawings,

fig. 1a shows a perspective view according to a first embodiment, to illustrate the structure of a hydraulic clamping tool according to the present invention,

figure 1b shows a perspective cross-sectional view of the hydraulic clamping tool according to figure 1a,

figure 1c shows a further perspective cross-sectional view of the hydraulic clamping tool according to figure 1a,

fig. 2a shows a partially transparent view according to a second embodiment, to illustrate the structure of a hydraulic clamping tool according to the invention,

figure 2b shows a partially transparent sectional view of the hydraulic clamping tool according to figure 2a,

fig. 3a shows a partially transparent view according to a third embodiment to illustrate the structure of a hydraulic clamping tool according to the invention, an

Fig. 3b shows a partially transparent sectional view of the hydraulic clamping tool according to fig. 3 a.

Detailed Description

Fig. 1a, 1b and 1c show a first exemplary embodiment of a hydraulic clamping tool 1 according to the invention. Fig. 2a and 2b show a second exemplary embodiment of a hydraulic clamping tool 1 according to the invention. Fig. 3a and 3b also show a third exemplary embodiment of a hydraulic clamping tool 1 according to the invention.

According to fig. 1a, 1b and 1c, the hydraulic expansion clamping tool 1 has integrated therein a channel 3 for clamping a workpiece (not shown in these figures), which channel has a hydraulic fluid (not shown here). The hydraulic fluid is intended to be pressurized in order to clamp the workpiece in the workpiece receiving opening 16 in the hydraulic expansion chuck 1. The hydraulically expandable chuck has an axis of rotation 15 about which the hydraulically expandable chuck rotates. Further, the hydraulic expansion type chuck 1 has two end surfaces 1a, 1b, an inner peripheral surface 4 and an outer peripheral surface 5. The hydraulic expansion chuck 1 is manufactured by an additive manufacturing process. In the present case, the hydraulic expansion chuck 1 is made of martensitic tool steel. Further, the hydraulic expansion chuck 1 is substantially annular. A retaining profile 6 is formed on the inner circumferential surface 4 of the hydraulic clamping tool 1.

The channel 3, which is located inside the hydraulic clamping tool 1 and is shown in fig. 1b and 1c, has a circumferential, substantially circular channel section 3a, which is formed radially between an inner circumferential surface 4 and an outer circumferential surface 5 of the hydraulic clamping tool 1. The channel 3 also has a plurality of further channel segments 7 which extend in the direction of the retaining contour 6. In the present case, the retaining profile 6 comprises a plurality of expansion lugs 6a which are intended to expand radially inwards and in both circumferential directions when clamping the workpiece in order to clamp the workpiece. For this purpose, the further channel section 7 is on the one hand approximately T-shaped and also extends over a large part of the axial length of the expansion lobe 6 a. The expansion lug 6a extends between the two end faces 1a, 1b and has a constant lug height H (see fig. 1 b).

According to fig. 2a and 2b, a hydraulic expansion chuck 1 for clamping a workpiece 2 (in the present case a gear) has a channel 3 integrated therein, which contains a hydraulic fluid (not shown here). The hydraulic fluid is intended to be pressurized in order to clamp the workpiece 2 in a workpiece receiving opening 16 (see fig. 1a) in the hydraulic expansion chuck 1. Like reference numerals to fig. 1a to 1c denote like elements. In the present case, the hydraulic cylinder 8 is fluidly connected to the channel 3 and is intended to introduce a pressure to the hydraulic fluid. Furthermore, a breather cylinder 9 is fluidly connected to the channel 3 and is provided to breather the channel 3. On the front end 1b of the hydraulic expansion chuck 1 there is also a flange part 13 for positioning the workpiece 2 axially in the hydraulic expansion chuck 1 and fixed by means of a screw element 14.

Like the hydraulic expansion chuck 1 according to the first embodiment, the hydraulic expansion chuck 1 according to the second embodiment is produced by an additive manufacturing process and is made of martensitic tool steel in a substantially annular shape. A retaining contour 6 is formed on the inner circumferential surface 4 of the hydraulic clamping tool 1, the shape of which corresponds to the geometry of the teeth of the workpiece 2. The retaining profile 6 according to the second embodiment substantially corresponds to the retaining profile 6 according to the first embodiment.

The channel 3, which is located inside the hydraulic clamping tool 1 and is shown in fig. 2a and 2b, has a first substantially circular circumferential channel section 3a and a second substantially circular circumferential channel section 3b, wherein the two circumferential channel sections 3a, 3b are axially spaced apart from one another and are fluidically connected to one another via a further channel section 7. The further channel section 7 is guided in the direction of the retaining contour 6 on the inner circumferential surface 4. By screwing the hydraulic cylinder 8 into a bore 12 provided on the hydraulic expansion chuck 1, hydraulic fluid is pressed out of the first circumferential channel section 3a into the further channel section 7, where the retaining profile 6 expands, so that the workpiece 2 is held in a rigid and non-rigid manner.

The third exemplary embodiment of the hydraulic clamping tool 1 according to fig. 3a and 3b essentially corresponds to the second exemplary embodiment of the hydraulic clamping tool 1 according to fig. 2a and 2 b. The third embodiment of the hydraulic clamping tool 1 differs from the second embodiment of the hydraulic clamping tool 1 only in that: a large number of cylindrical holding elements 10 are arranged partly movable at the holding profile 6 and intended to be partly displaced against the workpiece 2 when clamping the workpiece 2. An annular washer 11 is axially arranged on one end face of the hydraulic expansion tool 1 for axially receiving and partly movably mounting the receiving element 10 and is fixed by three screw elements 12.

Description of the reference numerals

1 Hydraulic clamping tool

1a, 1b end face

2 workpiece

3 channel

3a, 3b circumferential channel segments

4 inner peripheral surface

5 outer peripheral surface

6 holding profile

7 additional channel section

8 hydraulic cylinder

9 ventilating cylinder

10 receiving element

11 annular gasket

12 screw element

13 Flange member

14 screw element

15 axis of rotation

16 workpiece receiving opening

Height of H lug