Machine Tool Having Cable Guide Apparatus

Abstract

The invention relates to a cable guide apparatus, wherein the cable guide apparatus comprises: a guide apparatus, a slide which is movably guided in the guide apparatus, a deflection roller which is connected to the slide, a first tension weight, a cable pull apparatus which connects the first tension weight to the slide guided in the guide apparatus, wherein the connection cable has a free end and a fixed end connected to a connection apparatus and extends over the deflection roller, a second tension weight and a second guide apparatus in which the tension weights are each movably guided, such that the connection cable extending over the deflection roller is preloaded in a first displacement region of the free end by a force generated by the weight force of the first tension weight and is preloaded in a second displacement region of the free end by a force generated by a total of the weight forces of the tension weights.

Claims

1. A numerically controlled machine tool (10) having a cable guide apparatus (100) for providing and guiding a flexible connection cable (101) of a cable-connected tool (12), said machine tool (10) comprising at least: a machining apparatus (11) configured to receive the cable-connected tool (12), one or more numerically controlled machine axes configured to position the machining apparatus (11) and a workpiece to be machined relative to one another, and the cable guide apparatus (100) comprises: a first guide apparatus (110), a slide (111) movably guided in the first guide apparatus (110), a first deflection roller (103) rotatably connected to the slide (111), a first tension weight G.sub.1 (121), a cable pull apparatus (130) connecting the first tension weight G.sub.1 (121) to the slide (111) guided in the first guide apparatus (110), wherein the connection cable (101) runs over the first deflection roller (103) and connects the cable-connected tool (12) to a connection apparatus (102) of the machine tool (10), characterized in that the cable guide apparatus (100) further comprises: a second tension weight G.sub.2 (122), and a second guide apparatus (120) in which the tension weights G.sub.1 (121) and G.sub.2 (122) are each guided in a movable manner, such that the connection cable (101) running over the first deflection roller (103) is pretensioned in a first displacement region of the cable-connected tool (12) by a force generated by the weight of the first tension weight G.sub.1 (121) and is pretensioned in a second displacement region of the cable-connected tool (12) by a force generated by a sum of the weights of the tension weights G.sub.1 (121) and G.sub.2 (122).

2. The machine tool (10) according to claim 1, characterized in that the second guide apparatus (120) includes a first stop apparatus AG.sub.1 (123) for the first tension weight G.sub.1 (121) and a second stop apparatus AG.sub.2 (124) for the second tension weight G.sub.2 (122) which define the respective starting positions of the tension weights G.sub.1 (121) and G.sub.2 (122) with respect to the second guide apparatus (120) and thus define the first and the second displacement regions.

3. The machine tool (10) according to claim 1, characterized in that the cable-connected tool (12) is a cable-connected laser tool for laser-based machining.

4. The machine tool (10) according to claim 3, characterized in that the cable-connected laser tool (12) is configured for additive laser processing and the connection cable (101) of the wired laser tool (12) includes at least one or more feed lines for powder mixtures for additive laser processing and a line fiber for laser guidance on the inside.

5. The machine tool (10) according to claim 1, characterized in that the cable guide apparatus (100) is configured such that a bending radius of the connection cable (101) does not fall below a cable-specific minimum bending radius.

6. The machine tool (10) according to claim 1, characterized in that the machine tool (10) has a work space configured for machining on the workpiece and a cable guide space adjacent to one side of the work space, wherein the cable guide space and the work space are separated from each other by a partition wall (20) provided with an opening (21) and the cable guide apparatus (100) arranged in the cable guide space is configured to guide the connection cable (101) through the opening (21) of the partition wall (20) into the work space.

7. The machine tool (10) according to claim 6, characterized in that the machine tool further includes a controllable flap (22) which is arranged at the opening (21) of the partition wall (20) and is configured to close and open the opening (21) of the partition wall (20).

8. The machine tool (10) according to claim 6, characterized in that the cable guide apparatus (100) further comprises a second deflection apparatus (104) configured to guide the connection cable (101), which comes from the connection apparatus (102) and runs over the first deflection roller (103), through the opening (21) of the partition wall (20) into the work space.

9. The machine tool (10) according to claim 6, characterized in that the machine tool (10) further comprises a storage station (140) configured to receive the cable-connected tool (12).

10. The machine tool (10) according to claim 9, characterized in that the storage station (140) for the cable-connected tool (12) is configured to be movable and configured to be moved through the opening (21) in the partition wall (20) between a storage position P0 in the cable guide space and to a transfer position P1 in the work space.

11. The machine tool (10) according to claim 10, characterized in that the first displacement region is defined such that, when the tool (12) is in the storage station (140), it extends from the storage position P0 in the cable guide space to the transfer position P1 in the work space.

12. The machine tool (10) according to claim 1, characterized in that the first and/or the second guide apparatus (110, 120) of the cable guide apparatus (100) are arranged such that directions of displacement of the slide (111) and/or the tension weights G.sub.1 (121) and G.sub.2 (122) guided in the second guide apparatus (120) extend vertically or in parallel to the Earth's gravitational field.

13. The machine tool (10) according to claim 1, characterized in that the connection between the cable pull apparatus (130) and the slide (111) guided in the first guide apparatus (110) is configured via an elastic or a viscoelastic element.

14. The machine tool (10) according to claim 1, characterized in that the cable guide apparatus (100) further comprises, in addition to the two tension weights G.sub.1 (121) and G.sub.2 (122), N additional tension weights [ZG.sub.1, . . . , ZG.sub.n, . . . , ZG.sub.N], with N≥1 and 1≤n≤N, which are each movably guided in the second guide apparatus (120) in such a way that the connection cable (101) running over the first deflection roller (103) in a (n+2)th displacement region of the N+2 displacement regions of the cable-bound tool (12) is pretensioned by a force generated by a sum of the weights of the tension weights G.sub.1 (121), G.sub.2 (122) and ZG.sub.1 to ZG.sub.n.

15. The machine tool (10) according to claim 1, characterized in that the slide (111) guided in the first guide apparatus (110) is further connected to the machine tool (10) via a restoring elastic element acting in the direction of displacement of the slide (111).

16. The machine tool (10) according to claim 1, characterized in that the machining apparatus (11) of the machine tool (10) is configured to be moved via three numerically controlled machine axes configured as linear axes.

17. The machine tool (10) according to claim 16, characterized in that the machine tool (10) further comprises two numerically controlled machine axes which are configured as rotary axes and are orthogonal or inclined to one another and which are configured to orient a machine table (13) configured to support the workpiece opposite the machining apparatus (11).

18. A cable guide apparatus (100) for providing and guiding a flexible connection cable (101), said cable guide apparatus (100) comprising: a first guiding apparatus (110), a slide (111) movably guided in the first guide apparatus (110), a first deflection roller (103) rotatably connected to the slide (111), a first tension weight G.sub.1 (121), a cable pull apparatus (130) connecting the first tension weight G.sub.1 (121) to the slide (111) guided in the first guide apparatus (110), wherein the connection cable (101) has a free end and a fixed end connected to a connection apparatus (102) and runs over the first deflection roller (103), characterized in that, the cable guide apparatus (100) further comprises: a second tension weight G.sub.2 (122), and a second guide apparatus (120) in which the tension weights G.sub.1 (121) and G.sub.2 (122) are each guided in a movable manner, such that the connection cable (101) running over the first deflection roller (103) is pretensioned in a first displacement region of the cable-connected tool (12) by a force generated by the weight of the first tension weight G.sub.1 (121) and is pretensioned in a second displacement region of the cable-connected tool (12) by a force generated by a sum of the weights of the tension weights G.sub.1 (121) and G.sub.2 (122).

19. The cable guide apparatus (100) according to claim 18, characterized in that the cable guide apparatus (100) further comprises one or more successive further deflection apparatus (104), which are each configured to deflect the connection cable (101) which comes from the fixed end on the connection apparatus (102) and runs over the first deflection roller (103).

20. The cable guide apparatus (100) according to claim 18, characterized in that the cable guide apparatus (100) further comprises, in addition to the two tension weights G.sub.1 (121) and G.sub.2 (122), N additional tension weights [ZG.sub.1, . . . , ZG.sub.n, . . . , ZG.sub.N], with N≥1 and 1≤n≤N, which are each movably guided in the second guide apparatus (120) in such a way that the connection cable (101) running over the first deflection roller (103) in a (n+2)th displacement region of the N+2 displacement regions of the cable-bound tool (12) is pretensioned by a force generated by a sum of the weights of the tension weights G.sub.1 (121), G.sub.2 (122) and ZG.sub.1 to ZG.sub.n.

Description

[0072] Further aspects and advantages thereof as well as more specific implementation options for the aspects and features mentioned above are described below with the aid of the drawings shown in the attached figures:

[0073] FIG. 1 shows a perspective view of a machine tool configured for laser-based machining, with a view of the work space.

[0074] FIG. 2a shows a section of the machine tool according to the invention with a view of the cable guide apparatus but without a view of the connection cable.

[0075] FIG. 2b shows the structure of the cable guide apparatus, which is the same as in FIG. 2a, on one side of the machine tool in an alternative perspective.

[0076] FIG. 3a shows a schematic sketch of part of the cable guide apparatus with a pretension of the connection cable being effected by the first deflection roller, the active forces being marked in a free body diagram.

[0077] FIG. 3b shows, as a supplement to the schematic diagram of the structure in FIG. 3a, an exemplary curve of the pretension acting on the connection cable via the first deflection roller of the cable guide apparatus.

[0078] FIG. 4 shows a reduced view of a section of the cable guide apparatus with a movable storage station for the cable-connected tool.

[0079] Here, the same or similar elements in the figures may be denoted by the same reference symbols, but sometimes also by different reference symbols.

[0080] It is emphasized that the present invention is in no way limited to the exemplary embodiments described below and implementation features thereof. The invention also includes modifications of the exemplary embodiments mentioned, in particular those resulting from modifications and/or combinations of one or more features of the exemplary embodiments described within the scope of the independent claims.

DETAILED DESCRIPTION OF THE FIGURES

[0081] FIG. 1 shows a perspective view of a machine tool 10 configured for laser-based machining according to the invention, with a view of the work space.

[0082] The illustration shows the numerically controlled machine tool 10 with a machining apparatus 11 that can be moved via three linear axes and carries a cable-connected tool 12, in this case a tool configured for laser machining, with a flexible connection cable 101.

[0083] The machining apparatus 11 with the tool 12 received is used for machining a workpiece (not shown here) fastened on the machine table 13, wherein the machine table 13 can be oriented in relation to the machining apparatus 11 via the two machine axes R1 and R2 which are orthogonal to one another and are configured as rotary axes.

[0084] The view shows the work space of the machine tool 10 in which the machining is performed on the workpiece attached to the machine table 13. The connection cable 101 of the cable-connected tool 12 is provided and guided by the cable guide apparatus 100 (not shown in this figure) which is arranged behind the partition wall 20 in the cable guide space adjacent to the work space. As a result, sensitive machine parts of the cable guide apparatus 100 are protected from contamination created during machining.

[0085] The connection cable is introduced through the opening 21 made in the partition wall 20, which in the exemplary embodiment shown can be closed by means of the controllable flap 22, which is shown in the open state in FIG. 1.

[0086] If the cable-connected tool 12 is not used, it is advantageously arranged in the cable guide space, which may be completely separated from the work space by closing the controllable flap 22.

[0087] By using the cable guide apparatus 100 (not shown here), the connection cable is pretensioned when used by the machining apparatus 11 according to the second displacement region by a force based on the sum of the weights of the two tension weights G.sub.1 121 and G.sub.2 122, so that a deflection of the connection cable 101 caused by its own weight as shown in FIG. 1 is greatly reduced. As a result, an obstruction of the machining of the workpiece due to the connection cable 101 or even a collision of the connection cable 101 with other machine parts of the machine tool 10, for example the machine table 13, can be prevented.

[0088] Furthermore, a reduction in the deflection of the connection cable is advantageous in that damage to the connection cable 101 itself as a result of excessive bending can be avoided.

[0089] FIG. 2a shows a section of the machine tool 10 according to the invention with a view of the cable guide apparatus 100, but without a view of the connection cable 101.

[0090] The illustration shows the two guide apparatus 110, 120, in which the slide 111 and the tension weights G.sub.1 121 and G.sub.2 122 are movably guided. The two guide apparatus 110, 120 are arranged vertically on one side of the machine tool 10 so that the displacement directions of the tension weights G.sub.1 121 and G.sub.2 122 and the slide 111 extend in parallel to the Earth's gravitational field. Moreover, the two guide apparatus 110, 120 in the exemplary embodiment shown are configured as guide rails arranged in parallel in order to ensure optimal and resistance-free guidance of the tension weights G.sub.1 121 and G.sub.2 122 and the slide.

[0091] In the exemplary embodiment shown, the cable pull apparatus 130 includes a connection cable 131 and two deflection rollers 132 and connects the slide 111 to the first tension weight G.sub.1 121.

[0092] The connection cable 101 (not shown here) runs from the connection apparatus 102 over the first deflection roller 103 and is guided by the second deflection apparatus 104 into the work space of the machine tool 10. The second deflection apparatus 104 is configured such that the connection cable 101 coming from the first deflection roller 103 and running vertically in this section is deflected on an approximately arc-shaped course into the work space, wherein a fall below a minimum bending radius of 200 mm of the connection cable 101 is not happening in this case. The second deflection apparatus 104 has a section that is tapered on the upper side so that the connection cable 101 entering at this point can be received in as precise a position as possible. The side of the second deflection apparatus that faces the work space for the supply line has a shape that is opening in order to ensure a corresponding freedom of movement of the cable-connected tool 12 when guided through the machining apparatus 11.

[0093] In contrast to the first deflection roller 103, the second deflection apparatus 104 is not configured to be movable. When moving, the connection cable slides over the surface of the second deflection apparatus, which is why a material pairing between the second deflection apparatus 104 and the connection cable 101 with the lowest possible coefficient of friction is to be preferred.

[0094] In the configuration of the cable guide apparatus 100 shown in FIG. 2a, only the weight of the first tension weight G.sub.1 121 acts via the connection cable 131 of the cable pull apparatus 130 on the slide 111 and thus on the first deflection roller 103 in order to pretension the connection cable 101 (not shown here).

[0095] The second tension weight G.sub.2 122 abuts against the stop apparatus AG.sub.2 124 configured for this purpose on the sides of the second guide apparatus 120. The second tension weight G.sub.2 122 is not connected to the connection cable 131 of the cable pull apparatus 130 so that its weight does not affect the pretension of the connection cable 101 in the configuration shown.

[0096] When the end of the connection cable 101 located at the tool 12 is increasingly deflected or shifted in the direction of the work space of the machine tool, the first deflection roller 103 is pulled vertically downward along the direction specified by the first guide apparatus 110.

[0097] Consequently, the cable pull apparatus 130 pulls the first tension weight G.sub.1 121 upwards along the direction specified by the second guiding apparatus 120. As the displacement of the first tension weight G.sub.1 121 increases, it comes into contact with the second tension weight G.sub.2 122, which is also guided in the second guide apparatus 120, at the transition between the first and second displacement regions. The contact surfaces of the two tension weights G.sub.1 121 and G.sub.2 122 are configured such that, as the first tension weight G.sub.1 121 is displaced upwards, the second tension weight G.sub.2 122 is also displaced. In this case, an underside of the second tension weight G.sub.2122 rests on an upper side of the first tension weight G.sub.1 121. As a consequence, the weight of the second tension weight G.sub.2 122 now also acts, via contact with the first tension weight G.sub.1 121, on the connection cable 131 of the cable pull apparatus 130 and thus on the slide 111 connected to the first deflection roller 103, so that the connection cable 101 running thereover is pretensioned by a force based on the sum of the weights of the two tension weights G.sub.1 121 and G.sub.2 122.

[0098] Accordingly, during a downward movement of the first and second tension weights G.sub.1 121 and G.sub.2 122 starting from the second displacement region, when the stop apparatus AG.sub.2 124 is reached, there is a loss of contact between the two tension weights 121, 122, so that, upon the transition to the first displacement region, only the weight generated by the first tension weight G.sub.1 121 is used to pretension the connection cable 101.

[0099] The position of the stop apparatus AG.sub.2 124 may be used here to adjust a transition point between the first and the second displacement regions.

[0100] It should be noted at this point that the implementation of the individual displacement regions with the different pretensions of the connection cable 101, in particular their transition into one another, is not limited to the direct contact between the tension weights 121, 122 presented in this exemplary embodiment. The pretension with the aid of a plurality of tension weights 121, 122 may also be implemented by means of corresponding stops fixed at predetermined positions on the connection cable 131 of the cable pull apparatus 130, wherein the connection cable 131 is guided past the tension weights 121, 122 or through cutouts in the tension weights 121, 122 and, as a result of the increasing deflection of the connection cable 131, contact is made between such a stop on the connection cable 131 and one of the tension weights 121, 122, so that the weight of the relevant tension weight 121, 122 is applied to the connection cable 131 via the fixed stop and thus acts on the slide 111 in the first guide apparatus 110.

[0101] It should also be noted that the cable pull apparatus 130 is in no way limited to the structure shown in FIG. 2a, but may also be arranged in a tackle-like form in order to achieve different transmission ratios between the force caused by the weight of the tension weights 121, 122 and the pretension acting on on the connection cable 101.

[0102] The structure of the cable guide apparatus 100 shown in FIG. 2a may be provided on one side of the machine tool 10 with little installation space and has a comparatively low depth and is therefore extremely space-saving.

[0103] FIG. 2b shows the structure of the cable guide apparatus 100, which is the same as in FIG. 2a, on one side of the machine tool 10 in an alternative perspective.

[0104] As a supplement to the perspective shown in FIG. 2a, the stop apparatus AG.sub.1 123 for the first tension weight G.sub.1 121 is also shown in FIG. 2b.

[0105] The stop apparatus AG.sub.1 123 defines a starting position of the first tension weight G.sub.1 121 and thus defines the first displacement region of the cable guide apparatus 100, with the first tension weight G.sub.1 additionally being prevented from falling out of the first guide apparatus 110. This proves to be particularly advantageous, for example, for maintenance and/or assembly work on the cable guide apparatus since, even if the connection cable 131 is free of tension or not fastened, the tension weight G.sub.1 121 cannot fall out of the guide.

[0106] There is also a detailed view of the slide 111 guided in the first guide apparatus 110. It has a triangular structure and is slidably mounted in one guide rail of the first guide apparatus 110 at two points and in the other guide rail of the first guide apparatus 110 at one point, so that jamming of the slide 111 can be reliably avoided. FIG. 3a shows a schematic sketch of a part of the cable guide apparatus 100 with a pretension of the connection cable 101 being effected by the first deflection roller 103, with the active forces being identified in a free body diagram.

[0107] The connection cable 101 coming from the connection apparatus 102 of the machine tool runs over the first deflection roller 103. A displacement of a point of the connection cable 101 after the first deflection roller 103 is denoted by x and indicates how strongly the connection cable 101 is deflected. The deflection roller is rotatably connected to the slide 111 (not shown in FIG. 3a), on which in turn a force F for pretensioning the connection cable 101 is exerted by the tension weights G.sub.1 and G.sub.2 via a connection cable 131 of the cable pull apparatus 130; the pretension is characterized by the free-body force S in FIG. 3a.

[0108] In the structure shown in FIG. 3a, the relationship S=0.5*F applies to the free-body force S as a function of the force F acting on the slide. Here, the free-body force S is interpreted as the normal force acting in the connection cable.

[0109] A deflection x>0 causes the first deflection roller 103, on which the force F acts, to be pulled downwards, wherein, depending on the deflection x, the force F is either based on the weight of the first tension weight G.sub.1 121 in the first displacement region or on the sum of the weights of the two tension weights G.sub.1 121 and G.sub.2 122 in the second displacement region.

[0110] FIG. 3b shows, as an addition to the schematic illustration of the structure in FIG. 3a, an exemplary curve of the pretension acting on the connection cable 101 through the first deflection roller 101 of the cable guide apparatus 100.

[0111] The masses of the tension weights G.sub.1 121 and G.sub.2 122 are denoted by the formula symbols m.sub.1 and m.sub.2 and the gravitational constant of the Earth's gravitational field is denoted by g. S designates the free-body force in the connection cable 101 that describes the pretension and x the deflection or displacement state thereof.

[0112] In the piecewise continuous curve shown, the first displacement region is in the range x.sub.0<x<x.sub.1 in which a weight of m.sub.1g acts on the slide via the cable pull apparatus 130. According to the force relationship described in the description of FIG. 3a, a free-body force S=0.5 m.sub.1g is thus obtained in the connection cable.

[0113] From a deflection x=x.sub.1, the transition from the first to the second displacement region occurs, as a result of which, for deflections x>x.sub.1, the pretension of the connection cable 101 is based on the sum of the weights of the two tension weights G.sub.1 121 and G.sub.2 122: S=0.5(m.sub.1g+m.sub.2g).

[0114] The exact position of the transition point x=x.sub.1 may be determined, inter alia, by the position of the stop apparatus AG.sub.1 and AG.sub.2 in the second guide apparatus 120,

[0115] With regard to the embodiment of the machine tool 10 with the movable storage station 140, the storage position P0 is to be selected such that it lies in the first displacement region with x.sub.0<x<x.sub.1. The transfer position P1 for transferring the cable-connected tool 12 to the machining apparatus 11 is preferably to be selected in the immediate vicinity of the transition point x=x.sub.1 within the first displacement region.

[0116] It is to be noted that the physical relationships shown in FIGS. 3a and 3b are based on simplifying assumptions and, for example, the effects of friction or the own weight of the connection cable 131 and the like were not taken into account since the illustration shown only serves to describe the mechanism functionally.

[0117] Even if this is not explicitly shown, the use of N additional tension weights (with N≥1) results, for the piecewise continuous curve of the pretension shown in FIG. 3b, in N further pretension stages with a respective displacement region in addition to the two pretension stages shown. With increasing deflection, the specified pretension, which is constant over a pretension region, turns out to be greater than the pretension in a previous pretension stage. This results in a step-like pretension profile with N+2 (pretension) stages in the direction of increasing deflections.

[0118] FIG. 4 shows a reduced illustration of a section of the cable guide apparatus 100 with the movable storage station 140 for the cable-connected tool 12. The tension weights G.sub.1 121 and G.sub.2 122 and the cable pull apparatus 130 are not shown in FIG. 4.

[0119] The connection cable 101 running over the first deflection roller 103 and over the second deflection apparatus 104 connects the connection apparatus 102 of the machine tool 10 to the cable-connected tool 12.

[0120] In the illustration shown in FIG. 4, the cable-connected tool 12 is not received by the machining apparatus 11 but is arranged in the storage station 140 of the machine tool 10, which is configured to be movable in the direction R.

[0121] To receive the cable-connected tool 12, the storage station 140 has a cutout on an upper side which is adapted to an outer contour of the tool 12 and into which the tool can be inserted with a precise fit.

[0122] The storage station 140 is configured to be moved in the direction R from a storage position P0 to a transfer position P1 in order to be received there by the machining apparatus 11 of the machine tool, with the direction of travel R advantageously extending orthogonally to the Earth's gravitational field.

[0123] The storage station 140 is positioned in such a way that the section of the connection cable 101 coming from the second deflection apparatus 104 runs almost in parallel to the direction of travel R. Consequently, the force acting on the cable-connected tool 12 from the connection cable 101 acts almost in parallel to the direction of travel R so that jamming of the tool 12 in the storage station can be avoided. Jamming is additionally prevented by the inventive configuration of the cable guide apparatus 100 of the machine tool since the pretension of the connection cable 101 when the tool 12 is in the storage station is preferably only effected by the weight of the first tension weight 121.

LIST OF REFERENCE SYMBOLS

[0124] 10 machine tool [0125] 11 machining apparatus [0126] 12 cable-connected tool [0127] 13 machine table [0128] 20 partition wall [0129] 21 opening in the partition wall [0130] 22 flap [0131] 100 cable guide apparatus [0132] 101 connection cable [0133] 102 connection apparatus [0134] 103 first deflection roller [0135] 104 second deflection apparatus [0136] 110 first guide apparatus [0137] 11 slide [0138] 120 second guide apparatus [0139] 121 first tension weight G.sub.1 [0140] 122 second tension weight G.sub.2 [0141] 123 first stop apparatus AG.sub.1 for first tension weight G.sub.1 [0142] 124 second stop apparatus AG.sub.2 for first tension weight G.sub.2 [0143] 130 cable pull apparatus [0144] 131 connection cable [0145] 132 deflection roller [0146] 140 storage station [0147] S free-body force in the connection cable [0148] F pulling force of the cable pull apparatus [0149] R direction of travel of the storage station [0150] R1 first rotary axis [0151] R2 second rotary axis