Tool slide for a machine tool

Abstract

The invention relates to a tool slide (1) for guiding a tool in a machine tool, comprising: a housing (2) which extends along a longitudinal axis (L), wherein the housing (2) at least partially consists of a carbon-fibre-reinforced plastic and defines a cavity (H) which extends along the longitudinal axis (L); and a spindle unit at least partially received in the cavity (H), the spindle unit having a tool-holding fixture at a first axial end. In order to create a tool slide for guiding a tool, which has a reduced weight, a design which is as simple as possible and also improved flexural rigidity, at least one reinforcing element (12) which consists of carbon-fibre-reinforced plastic and is intended for reinforcing the housing (2) is arranged in the cavity (H), the reinforcing element (12) extending along the longitudinal axis (L).

Description

[0001] Tool slide for a machine tool

[0002] The invention relates to a tool slide for a machine tool comprising a housing extending longitudinally along a longitudinal axis and a spindle unit at least partially accommodated in a cavity of the housing.

[0003] Machine tools are known in practice that comprise a tool movable in multiple directions, such as a milling head or a drilling head, for machining a workpiece. The machine tool comprises a tool carriage, which is designed for the generally relatively rapid translational movement of the tool relative to the workpiece. The tool carriage carrying the tool can be moved in at least one axial direction together with the tool. The tool carriage is usually mounted on rails and driven by a drive such as a spindle motor or a linear motor.

[0004] The tool carriage should be as thermally and mechanically stable as possible and, in particular, possess the highest possible flexural rigidity, enabling consistently high tool positioning accuracy during machining. Vibrations of the tool, which is carried and moved by the tool carriage, should be avoided as much as possible. Such vibrations adversely reduce tool life, i.e., the time the tool can be used without interruption until it needs to be reground or replaced.

[0005] It is also known from the prior art to use tool slides that are at least partially made of materials that are lighter than conventional steel materials. Advantageously, the energy required to move the tool slide is noticeably reduced at the same speed or acceleration values. Fiber-reinforced materials such as carbon fiber reinforced plastics (CFRP) or glass fiber reinforced plastics (GFRP) have proven particularly suitable. These also exhibit relatively high flexural rigidity, which is necessary for precise machining of the workpiece.

[0006] DE 10 2011 111 287 A1 shows a machine tool comprising three carriages movable on X, Y and Z guideways, wherein a work spindle is attached to the Z carriage carrying a tool, which work spindle can be moved in the Z direction together with the Z carriage. To drive the carriages, threaded spindles are provided which engage with threaded nuts firmly attached to the carriages. Alternatively, a linear motor can be provided which includes a magnetic power and coil. All three carriages are made of a lightweight material, preferably aluminum, wherein the axle bodies are essentially designed as hollow cuboids. To increase the flexural rigidity of the axle bodies, ribs are provided which are attached to the walls of the axle bodies and whose edge sections engage in slot-shaped openings in the axle bodies and are welded therein.The ribs are essentially designed as plates with a central recess, with the top and bottom of the ribs running in a plane perpendicular to a longitudinal axis of the axle body. The disadvantage is that multiple plates are required as reinforcement elements to increase flexural rigidity, which makes the design relatively complicated and also requires complex assembly.

[0007] DE 10 2011 108 982 A1 discloses a tool slide for guiding a tool, comprising a housing extending longitudinally along a longitudinal axis and having a base body made of carbon fiber-reinforced plastic, wherein a cavity is provided in the base body in which a work spindle is received. Furthermore, the tool slide comprises two reinforcing elements extending longitudinally along the longitudinal axis. DE 10 2013 112 834 A1 discloses a tool slide for guiding a tool, comprising a housing extending longitudinally along a longitudinal axis, wherein a work spindle is at least partially received in a cavity of the housing. The one-piece housing is made of fiber-reinforced plastic, wherein a flat stiffening rib is arranged in the cavity and is supported on fixing brackets attached to the opposite sides of the housing inside.

[0008] DE 10 2020 131 582 A1 shows a tool carriage comprising a housing extending longitudinally along a longitudinal axis, wherein the housing comprises an upper housing part and a lower housing part, which have at least one pair of connecting surfaces at which they are positively and detachably connected to one another.

[0009] It is the object of the invention to provide a tool carriage for guiding a tool, which has a reduced weight, a structure that is as simple as possible and also has improved flexural rigidity.

[0010] This object is achieved according to the invention by a tool carriage having the features of claim 1.

[0011] According to one aspect of the invention, a tool carriage for guiding a tool in a machine tool is provided, comprising a housing extending elongately along a longitudinal axis, wherein the housing consists at least partially of a carbon fiber reinforced plastic and defines a cavity extending elongately along the longitudinal axis. The tool carriage further comprises a spindle unit received at least partially in the cavity, wherein the spindle unit has, at a first axial end, a tool holder for a tool to be driven by the spindle unit. The tool carriage according to the invention is characterized in that at least one reinforcing element made of a carbon fiber reinforced plastic is arranged in the cavity to reinforce the housing, wherein the reinforcing element is designed to extend elongately along the longitudinal axis.Advantageously, improved flexural rigidity can be achieved using only a single additional element. In particular, reinforcement can be achieved over a large part of the length or even over the entire length of the housing using a single reinforcement element. This advantageously significantly simplifies the production of the tool slide.

[0012] The reinforcement element is preferably designed as a plate made of carbon fiber-reinforced plastic, with the plate having a top and a bottom. The top and bottom refer to the large areas defined by the side surfaces that determine the thickness of the plate. Advantageously, the reinforcement element is particularly simple to manufacture and can be produced in large quantities using established manufacturing processes in the field of fiber-reinforced plastics.

[0013] Particularly preferably, the top and bottom sides of the reinforcing element each extend in a plane parallel to the longitudinal axis of the housing. Advantageously, the reinforcing element acts like a cross brace between two opposing wall sections of the housing. This advantageously increases the flexural strength in a transverse direction perpendicular to the longitudinal axis of the housing.

[0014] In a particularly preferred embodiment, the reinforcing element has a coupling section in an edge region, which is provided for coupling to the housing. The edge region preferably runs along the longitudinal axis of the housing. Advantageously, a particularly strong connection can be realized between the reinforcing element and the housing, wherein in particular transverse forces acting on the housing can be absorbed particularly safely and reliably by the reinforcing element. Particularly preferably, the housing comprises a lower housing part and an upper housing part. Advantageously, the lower housing part and the upper housing part are designed as half-shells made of carbon fiber reinforced plastic. Advantageously, the housing can be produced simply by connecting the lower housing part and the upper housing part. Particularly preferably, the lower housing part and the upper housing part are connected to one another by a material fit.The lower and upper housing sections are particularly advantageously bonded together. This allows the housing to be manufactured particularly easily, cost-effectively, and flexibly, and also offers the possibility of integrating the reinforcement element particularly easily.

[0015] In an advantageous embodiment, the lower housing part and the upper housing part each have protruding connecting flanges on their sides, which serve to connect the lower housing part and the upper housing part to the reinforcing element. The connecting flanges are formed integrally with the lower housing part and the upper housing part, respectively. The connecting flanges expediently extend over the entire length of the lower housing part and the upper housing part, respectively, thus creating a particularly strong and reliable connection between them while forming the housing.

[0016] In a practical embodiment, the connecting flanges of the lower housing part are arranged on an upper edge of the lower housing part and the connecting flanges of the upper housing part are arranged on a lower edge of the upper housing part. The connecting flanges are advantageously arranged opposite one another and can thus be connected to one another particularly easily, whereby a continuous outer wall of the housing can be formed. Particularly advantageously, the connecting flanges of the lower housing part have flat upper sides which run parallel to flat lower sides of the connecting flanges of the upper housing part. The upper sides of the connecting flanges of the lower housing part preferably have a rectangular shape, wherein the long sides of the upper sides extend over the entire length of the lower housing part.Accordingly, the lower housing section has two connecting flanges that extend laterally along the long sides of the lower housing section. The undersides of the connecting flanges of the upper housing section also have corresponding rectangular shapes, with the long sides of the undersides extending over the entire length of the upper housing section. Advantageously, the connecting flanges, or the lower housing section and the upper housing section, can each be manufactured from a single sheet of carbon fiber reinforced plastic by forming the sheet accordingly, with the connecting flanges being molded onto the long edges of the sheet. Furthermore, the flat upper and lower sides enable particularly reliable bonding, as the available adhesive surfaces are maximized.

[0017] In an advantageous development, the reinforcing element has coupling sections on its edge regions extending laterally along the longitudinal axis, which are arranged between the connecting flanges of the lower housing part and the upper housing part. For this purpose, during the manufacture of the tool slide, the reinforcing element is preferably placed on the lower housing part and aligned, with the coupling sections of the reinforcing element and the connecting flanges of the lower housing part overlapping. The upper housing part is then placed on top, with the coupling sections of the reinforcing element and the connecting flanges of the upper housing part also overlapping, so that the coupling sections of the reinforcing element and the connecting flanges of the lower housing part and the upper housing part can be integrally connected, in particular glued, to one another.

[0018] Particularly preferably, the coupling sections of the reinforcing element and the connecting flanges of the lower housing part and the upper housing part have bores, wherein the bores are arranged congruently with one another. Advantageously, when the lower housing part, reinforcing element, and upper housing part are placed one above the other, continuous bores run through the connecting flanges and the coupling sections of the reinforcing element. The bores are preferably arranged equidistant from one another, with the bore centers running on a line along the longitudinal extent of the connecting flanges. Advantageously, the bores are each penetrated by a connecting element. The connecting element is preferably designed as a base body made of metal.

[0019] The connecting element is advantageously also secured within the bore by adhesive bonding. Advantageously, the connecting elements, which are arranged in the congruent bores of the coupling sections of the reinforcing element and the connecting flanges of the lower and upper housing parts, reliably absorb forces acting in a plane running parallel to the upper sides of the connecting flanges of the lower housing part or to the undersides of the connecting flanges of the upper housing part. In particular, this prevents the adhesive layer present between the coupling sections of the reinforcing element and the connecting flanges of the lower and upper housing parts from being subjected to excessive forces, which could cause the adhesive to detach and thus shift the lower and upper housing parts, the upper housing parts, and the reinforcing element relative to one another.

[0020] Further advantages, properties, features, and developments of the claimed invention will become apparent from the following description of a preferred embodiment and from the dependent claims. The invention is explained in more detail below with reference to the accompanying drawings.

[0021] Fig. 1 shows a preferred embodiment of a tool carriage according to the invention in an exploded view.

[0022] Fig. 2 shows the tool carriage 1 in a cross-sectional view.

[0023] Fig. 1 shows a preferred embodiment of a tool carriage 1 according to the invention in an exploded view. The tool carriage 1 comprises a housing 2 which extends elongately along a longitudinal axis L and is formed by a lower housing part 3 and a upper housing part 4. In the embodiment shown here, the lower housing part 3 and the upper housing part 4 are half-shells made entirely of carbon fiber reinforced plastic (CFRP), so that the housing 2 is advantageously significantly lighter than a housing made of steel and the tool carriage 1 can be moved along the longitudinal axis L of the housing 2 in a significantly more energy-efficient manner. The embodiment shown here is a vertical carriage which can be moved in the Z direction.

[0024] Arranged in the housing 2 is a spindle unit 5, which has a tool holder 6 at a first end 5a, in which the tools required for machining a workpiece can be clamped. The tool (not shown here), for example a milling cutter or a drill, is then driven by the spindle unit 5 to rotate about a spindle axis S. The tool holder 6 protrudes axially from the housing 2 so that the tool can be changed automatically or manually or can be moved toward the workpiece for machining.

[0025] To secure the spindle unit 5 in the housing 2, the housing base 3 has a fastening profile 7 at a first end 3a, to which the spindle unit 5 is screwed via a flange 5b. Advantageously, the spindle unit 5 can be securely connected to the tool carriage 1 and, at the same time, can be easily removed from the tool carrier unit 1 for maintenance purposes.

[0026] The tool carriage 1 further comprises a metal cover plate 8 that can be fastened to the end face in the area of ​​the tool holder 6 and can be screwed to a cover 9 arranged partially over the housing 2. The cover thus created advantageously prevents the ingress of dust and moisture. The upper housing part 4 has at least one first recess 10 in the area of ​​the electrical connection points 11 of the spindle unit 5, so that these are advantageously accessible for maintenance purposes. In the exemplary embodiment shown here, the upper housing part 4 has a second recess (not visible here), which is arranged opposite the first recess 10.

[0027] A reinforcing element 12 is arranged between the upper housing part 4 and the lower housing part 3, which serves to increase the flexural rigidity of the housing 2. In the exemplary embodiment shown here, the reinforcing element 12 is designed as a plate made of carbon fiber-reinforced plastic with an upper side 12a and a lower side 12b (which is concealed here). The reinforcing element 12 has a recess 13 in the region of the spindle unit 5, so that the spindle unit 5 remains accessible through the recess 10 in the lower housing part 4 when the tool slide 1 is assembled. Furthermore, the reinforcing element 12 can be arranged with its entire length between the lower housing part 3 and the upper housing part 4.

[0028] In the edge regions 12c running parallel to the longitudinal axis L, the reinforcing element 12 has two parallel coupling sections 12d with a plurality of bores 14, which are provided for connection to the housing 2. In the exemplary embodiment shown here, the lower housing part 3 has two opposing connecting flanges 15a, 15b with bores 16 that can be arranged congruently with the bores 14 of the reinforcing element 12, in which connecting elements 17 made of metal, in particular steel, are inserted, which serve to align and connect the lower housing part 3, the upper housing part 4, and the reinforcing element 12. The upper housing part 4 also has, in an edge region, two connecting flanges 18a, 18b extending elongately along the longitudinal axis L, with corresponding bores 19, into which the connecting elements 17 are inserted when connecting the lower housing part 3 and the upper housing part 4.Advantageously, the relative position of the lower housing part 3, the upper housing part 4 and the reinforcing element 12 is thus determined and occurring forces which act in a direction transverse to a longitudinal extension of the connecting elements 17 are safely absorbed.

[0029] A guide rail 20 is arranged below each of the fastening flanges 15a, 15b of the lower housing part 3, which, like the fastening flanges 15a, 15b, run parallel to the longitudinal axis L, so that the tool carriage 1 can advantageously be moved parallel to the longitudinal axis L. A linear motor (not shown here) is provided to drive the tool carriage 1, which enables rapid movement of the tool carriage along the longitudinal axis L.

[0030] Fig. 2 shows the tool carriage 1 in a cross-sectional view. The cross-section runs perpendicular to the longitudinal axis L of the housing 2 in the region of the recess 13 of the reinforcing element 12. In this view, it can be seen that the housing 2 is formed by the housing lower part 3 and the housing upper part 4, each designed as a half-shell. The housing lower part 3 has three wall sections 3c, 3d, 3e arranged at an angle to one another. The first connecting flange 15a adjoins an outer edge of the first wall section 3c and the second connecting flange 15b adjoins an outer edge of the third wall section 3e.

[0031] The first connecting flange 15a and the second connecting flange 15b each have a flat upper side 21, which lies opposite the flat lower sides 22 of the connecting flanges 18a, 18b of the upper housing part 4. The two opposing coupling sections 12c of the reinforcing element 12 rest on the upper sides 21. The first connecting flange 15a and the second connecting flange 15b of the lower housing part 3 are each penetrated by a bore 16, into which one of the connecting elements 17 shown in Fig. 1 is inserted. The connecting element 17 has a flat head 17a and an internal thread 17b, with the head 17a abutting against a stop surface provided in the bore 16. This advantageously allows the connecting element 17 to always be brought into a predefined position relative to the housing 2 and the reinforcing element 12.The internal thread 17b serves to connect the housing 2 with the rail 20 not shown here (see Fig. 1 ).

[0032] The connecting element 17 also passes through the bores 14 provided in the coupling region 12d of the reinforcing element 12 and the bore 19 provided in the opposite first connecting flange 18a of the housing upper part 4. The first connecting flange 18a or the second connecting flange 18b of the housing upper part 4 also adjoins laterally the outer of several wall sections 4c, 4d, 4e of the housing upper part 4, which each enclose an angle with one another.

[0033] The two laterally provided coupling sections 12d of the reinforcing element 12 are arranged between, or clamped between, the upper sides 21 of the first connecting flange 15a and the second connecting flange 15b of the lower housing part 3 and the undersides 22 of the first connecting flange 18a and the second connecting flange 18b of the upper housing part 4. To connect the lower housing part 3, the reinforcing element 12, and the upper housing part 4, these are glued together using the connecting elements 17. The reinforcing element 12 thus extends transversely through a cavity H defined by the housing 2, with the reinforcing element 12 being arranged in a center plane M lying between the lower housing part 3 and the upper housing part 4. Transverse forces acting in this center plane are advantageously reliably absorbed by the reinforcing element 12, which increases the overall flexural strength of the housing 2.

Claims

PATENT CLAIMS 1. Tool carriage (1) for guiding a tool in a machine tool, comprising a housing (2) which extends longitudinally along a longitudinal axis (L), the housing (2) being made at least partially of a carbon fiber reinforced plastic and defining a cavity (H) which extends longitudinally along the longitudinal axis (L), a spindle unit (5) which is at least partially received in the cavity (H), the spindle unit (5) having a tool holder (6) at a first axial end (5a), characterized in that at least one reinforcing element (12) made of carbon fiber reinforced plastic is arranged in the cavity (H) for reinforcing the housing (2), the reinforcing element (12) being designed to extend longitudinally along the longitudinal axis (L).

2. Tool carriage according to claim 1, characterized in that the reinforcing element (12) is designed as a plate made of carbon fiber reinforced plastic, the plate having an upper side (12a) and a lower side (12b).

3. Tool carriage according to claim 2, characterized in that the upper side (12a) and the lower side (12b) of the reinforcing element (12) each extend in a plane parallel to the longitudinal axis (L) of the housing (2).

4. Tool carriage according to claim 1 or 2, characterized in that the reinforcing element (12) has a coupling section (12d) in an edge region (12c) which is provided for coupling to the housing (2).

5. Tool slide according to claim 4, characterized in that the edge region (12c) runs along the longitudinal axis (L) of the housing (2).

6. Tool carriage according to one of the preceding claims, characterized in that the housing (2) comprises a lower housing part (3) and an upper housing part (4).

7. Tool carriage according to claim 6, characterized in that the lower housing part (3) and the upper housing part (4) are designed as half-shells made of carbon fiber reinforced plastic.

8. Tool carriage according to claim 7 or 6, characterized in that the housing lower part (3), the housing upper part (4) and the reinforcing element (12) are integrally connected to one another.

9. Tool carriage according to claim 8, characterized in that the lower housing part (3) and the upper housing part (4) are glued together.

10. Tool carriage according to one of claims 6 to 9, characterized in that the housing lower part (3) and the housing upper part (4) each have projecting connecting flanges (15a, 15b; 18a, 18b) on their sides, which serve to connect the housing lower part (3) and the housing upper part (4) to the reinforcing element (12). 11 . Tool carriage according to claim 10, characterized in that the connecting flanges (15a, 15b; 18a, 18b) are formed integrally with the housing lower part (3) or the housing upper part (4).

12. Tool slide according to claim 10 or 11, characterized in that the connecting flanges (15a, 15b; 18a, 18b) extend over the entire length of the lower housing part (3) or the upper housing part (4).

13. Tool carriage according to one of claims 10 to 12, characterized in that the connecting flanges (15a, 15b) of the lower housing part (3) are arranged on an upper edge of the lower housing part (3) and the connecting flanges (18a, 18b) of the upper housing part (4) are arranged on a lower edge of the upper housing part (4).

14. Tool slide according to claim 13, characterized in that the connecting flanges (15a, 15b) of the lower housing part (3) have flat upper sides (21) which run parallel to flat lower sides (22) of the connecting flanges (18a, 18b) of the upper housing part (4).

15. Tool carriage according to claim 14, characterized in that the upper sides (21) of the connecting flanges (15a, 15b) of the housing lower part (3) have a rectangular shape, wherein the long sides of the upper sides (21) extend over the entire length of the housing lower part (3).

16. Tool carriage according to claim 15, characterized in that the undersides (22) of the connecting flanges (18a, 18b) of the housing upper part (4) also have corresponding rectangular shapes, wherein the long sides of the undersides (22) extend over the entire length of the housing upper part (4).

17. Tool carriage according to one of claims 10 to 16, characterized in that the reinforcing element (12) has coupling sections (12d) on its edge regions (12c) extending laterally along the longitudinal axis (L), which coupling sections are arranged between the connecting flanges (15a, 15b; 18a, 18b) of the lower housing part (3) and the upper housing part (4).

18. Tool carriage according to claim 17, characterized in that the coupling sections (12d) of the reinforcing element (12) and the Connecting flanges (15a, 15b; 18a, 18b) of the lower housing part (3) and the upper housing part (4) have bores (14; 16; 19), wherein the bores (14; 16; 19) are arranged congruently with one another.

19. Tool carriage according to claim 18, characterized in that the bores (14; 16; 19) are arranged equidistant from one another, the bore centers running on a line along the longitudinal extent of the connecting flanges (15a, 15b; 18a, 18b).

20. Tool carriage according to claim 18 or 19, characterized in that the bores (14; 16; 19) are each penetrated by a connecting element (17). 21 . Tool carriage according to claim 20, characterized in that the connecting element (17) is designed as a base body made of metal.

22. Tool slide according to claim 20 or 21, characterized in that the connecting element (17) is fixed within the bore by gluing.

Images