Cooling attachment for a work machine

Abstract

A cooling attachment can be releasably fastened to a work machine, which has a shaft in which a rod-like tool is guided with a rotary or hammering action and exits the shaft at a free end. The cooling attachment has a housing that encloses the work machine and in particular the shaft thereof and the tool that exits it, the latter only partially. Formed within the housing is a first cooling channel for conducting a coolant from an inlet opening to the tool exiting the free end of the housing shaft. In order to improve the cooling of the tool without cooling the workpiece to be machined, at least one connecting hole is provided, at the free end of the housing shaft, between the first cooling channel and a second cooling channel, in order to divert the coolant from the first cooling channel into the second cooling channel.

Claims

1.-17. (canceled)

18. A cooling attachment (100) for releasably fastening to a work machine (200), the work machine (200) having a rod-shaped tool (300) that is guided for a rotary or hammering action within a shaft (210) and exits the shaft at a free end, the cooling attachment (100) comprising: a housing (110) with a housing shaft (112) for releasable mounting on the shaft (210) of the work machine, wherein the housing shaft has a free end (114) for at least partially enclosing the free end of the shaft of the work machine and the tool (300) exiting therefrom; a first cooling channel (120) extending in a longitudinal direction of the housing formed within the housing for conducting a coolant from an inlet opening (122) at an end (116) of the housing (110) close to the work machine to the free end of the housing shaft for cooling the rod-shaped tool (300); a second cooling channel (130) extending in the longitudinal direction of the housing (110) formed within the housing for conducting the coolant from the free end (114) of the housing shaft to at least one outlet opening (126), which is formed at the end (116) of the housing close to the work machine; and at least one connecting hole (150) at the free end of the housing shaft (112) between the first cooling channel (120) and the second cooling channel (130) for diverting the coolant from the first cooling channel (120) into the second cooling channel (130).

19. The cooling attachment (100) according to claim 18, wherein the first cooling channel (120) and the second cooling channel (130) are coaxial annular channels.

20. The cooling attachment (100) according to claim 18, wherein the first cooling channel (120) is formed within an outer wall of the housing (110); and wherein the second cooling channel (130) is formed radially further inside than the first cooling channel (120) within the housing (110).

21. The cooling attachment (100) according to claim 20, wherein the second cooling channel (130) is only partially bounded by a wall radially remote from a longitudinal axis (L) of the housing as part of the housing and is open towards the longitudinal axis (L) of the housing in another, radially more inner part.

22. The cooling attachment (100) according to claim 18, wherein the cooling attachment has a cavity (160) for receiving the shaft (210) of the work machine (200), and for passage of the tool (300) at the free end (114) of the housing shaft (112); and wherein the at least one connecting hole (150) is formed tangentially to an edge of the cavity from the first cooling channel.

23. The cooling attachment (100) according to claim 18, wherein a plurality of outlet openings (126) are arranged in a manner distributed over a circumference of the housing (110).

24. The cooling attachment (100) according to claim 18, wherein the at least one outlet opening (126) is designed to be conical.

25. The cooling attachment (100) according to claim 18, wherein the free end of the housing shaft (112) is designed to be conically tapered towards a longitudinal axis (L) of the housing.

26. A device (400), comprising: a work machine (200) with a shaft (210), in which a rod-shaped tool (300) is guided with a rotary or hammering action, wherein the rod-shaped tool exits a free end of the shaft (210) of the work machine; and a cooling attachment (100), comprising a housing (110) with a housing shaft (112) for releasable mounting on the shaft (210) of the work machine, wherein the housing shaft has a free end (114) for at least partially enclosing the free end of the shaft of the work machine and the tool (300) exiting therefrom; a first cooling channel (120) extending in a longitudinal direction of the housing formed within the housing for conducting a coolant from an inlet opening (122) at an end (116) of the housing (110) close to the work machine to the free end of the housing shaft for cooling the rod-shaped tool (300); a second cooling channel (130) extending in the longitudinal direction of the housing (110) formed within the housing for conducting the coolant from the free end (114) of the housing shaft to at least one outlet opening (126), which is formed at the end (116) of the housing close to the work machine; and at least one connecting hole (150) at the free end of the housing shaft (112) between the first cooling channel (120) and the second cooling channel (130) for diverting the coolant from the first cooling channel (120) into the second cooling channel (130).

27. The device (400) according to claim 26, wherein at least a part of the work machine (200) is received in a cavity (160) of the cooling attachment (200).

28. The device (400) according to claim 27, wherein the cavity (160) at the free end of the housing shaft is formed by a hole (162), a cross-section of which substantially corresponds to a cross-section of the tool (300) exiting therefrom.

29. The device (400) according to claim 28, wherein the connecting hole (150) between the first cooling channel (120) and the second cooling channel (130) at the free end (114) of the housing shaft is directed tangentially towards the tool (300) exiting the shaft (210) of the work machine (200).

30. The device (400) according to claim 26, wherein a radially inner wall of the second cooling channel (130) is formed by an outer wall of the work machine (200) and by an outer wall of the tool (300), where the tool (300) exits the shaft (210) of the work machine.

31. A method, comprising: providing the device (400) according to claim 26; and introducing the coolant through the inlet opening (122) in the housing (110) of the cooling attachment (100) into the first cooling channel (120), wherein the coolant is air, wherein the coolant is directed through the first cooling channel onto the tool (300) exiting the shaft (210) of the work machine and is deflected there into the second cooling channel (130), for cooling the tool and the work machine (200) and for exiting the second cooling channel (130) from the at least one outlet opening (126) attached at the end (116) on a work machine side of the housing (110).

32. The method according to claim 31, wherein the coolant flows turbulently during its return path in the second cooling channel (130).

33. The method according to claim 31, wherein the at least one outlet opening (126) is conical, and wherein the coolant is drawn at least into the second cooling channel (130) towards the at least one outlet opening (126).

34. A method, comprising: producing the cooling attachment (100) in accordance with claim 18 by 3D printing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 shows an external perspective view of a cooling attachment;

[0018] FIG. 2 shows a longitudinal section of a device including a work machine and a cooling attachment;

[0019] FIG. 3 shows the device at its free end in an enlarged view of FIG. 2; and

[0020] FIG. 4 shows the device in a cross-section.

DETAILED DESCRIPTION

[0021] The invention is described in detail below with reference to the specified figures in the form of exemplary embodiments. In all figures, the same technical elements are designated with the same reference signs.

[0022] FIG. 1 shows an external perspective view of the cooling attachment 100. The cooling attachment has a housing 110 with a shaft 112. The housing with the housing shaft is formed with a cavity 160 for releasably receiving a work machine 200, typically also with a shaft 210; see FIG. 2. The free end of the housing shaft 112 is preferably designed to be conically tapered towards the longitudinal axis L of the cooling attachment. At its end 116 close to the work machine, which is opposite the free end 114 at a distance, the housing 110 of the cooling attachment 100 has an inlet opening 122 and preferably a plurality of outlet openings 126 for a coolant for cooling the possibly received work machine 200 and a rod-like tool 300 exiting the shaft 210 of the work machine and the housing shaft 112; see FIG. 2.

[0023] FIG. 2 shows the device 400, which shows the cooling attachment 100 placed on the work machine 200. In other words, the device 400 refers to the work machine 200 if it is received in the cavity 160 of the cooling attachment 100. The shaft 210 of the work machine 200 is then also received by the shaft 112 of the housing 110 and the tool 300 driven by the work machine 200 exits a hole 162 at the free end 114 of the housing shaft 112. The tool 300 is driven in rotation by the work machine 200 or moved up and down by hammering along the longitudinal axis L of the housing 110, which coincides with the longitudinal axis of the shaft 210 of the work machine.

[0024] In the longitudinal section through the device 400 shown in FIG. 2, it can be seen that here a first cooling channel 120 extending in the longitudinal direction of the housing is formed in the outer wall of the housing 110 of the cooling attachment in order to conduct a coolant from the inlet opening 122 at the end 116 close to the work machine to the free end 114 of the housing shaft for cooling the rod-like tool 300 there. At least one connecting hole 150 is arranged within the free end of the housing shaft 112, which is preferably designed in the form of a plurality of annularly arranged nozzle openings, in order to divert the incoming coolant there into a second cooling channel 130 after it impacts the tool 300 to be cooled. The nozzle openings are preferably not centered on the longitudinal axis L of the housing/the tool 300, but are directed tangentially to the edge of the hole 162/tangentially to the tool 300, for example the needle of a needle embosser. The tangential direction of the nozzle openings and thus of the coolant flow causes swirling and thus, advantageously, an improved cooling effect of the coolant flow. The second cooling channel 130 guides the coolant from the free end 114 back to the end 116 of the housing 110 close to the work machine, so that it can exit the outlet openings 126 there. The outlet openings 126 are preferably designed to be conical, in order to draw the coolant through the inlet opening 122 and the first cooling channel 120 into the second cooling channel 130.

[0025] As can be seen in FIG. 2, the first cooling channel 120 and the second cooling channel 130 are preferably in each case designed as an annular channel and they preferably run coaxially to one another. While the first cooling channel 120 is formed entirely within the wall of the housing 110, the second cooling channel 130 is only partially bounded by a wall radially remote from the longitudinal axis L of the housing 110 as part of the housing 110. The second cooling channel of the cooling attachment is open towards the longitudinal axis L of the housing in another, radially more inner part, that is, it is not bounded by the housing 110 itself. Instead, the boundary of the second cooling channel is formed there by the outer surface of the work machine 200 and in particular the shaft 210 thereof itself. That is, while the coolant flows in the second cooling channel 130 to the outlet openings 126, it automatically flows along the work machine 200 and the shaft 210 thereof and cools such parts in this manner.

[0026] FIG. 3 shows an enlarged view of the free end of the housing shaft 114 in accordance with FIG. 2. It can be seen that the tool 300 exits the free end 114 of the housing shaft, in order to machine the workpiece 500.

[0027] FIGS. 3 and 4 show that the hole 162 has a cross-section that substantially corresponds to the cross-section of the tool 300 passing through it. The gap between the tool 300 and the edge of the hole 162 should be as small as possible, so that the coolant is prevented from exiting through such gap as far as possible. In this manner, undesired cooling of the workpiece 500 to be machined is prevented.

[0028] FIG. 4 shows the introduction of the coolant through the inlet opening 122 into the first cooling channel 120, which is designed as an annular channel. In the center of FIG. 4, it can be seen that the annularly arranged connecting holes/nozzle openings 150 in the free end 114 of the shaft 112 of the housing 110 are not aligned exactly radially to the longitudinal axis L of the housing, but are aligned tangentially to the edge of the hole 162/the edge of the workpiece 300, in order to achieve the desired swirling of the coolant there. In this respect, FIG. 4 shows a cross-section through the cooling attachment not only in a plane in the region of the end 116 of the housing close to the work machine at the level of the inlet opening 122, but also in a plane in the free end 114 of the housing shaft 112.

LIST OF REFERENCE SIGNS

[0029] 100 Cooling attachment [0030] 110 Housing [0031] 112 Housing shaft [0032] 114 Free end of the housing shaft [0033] 116 End of the cooling attachment close to the work machine [0034] 120 First cooling channel [0035] 122 Inlet opening [0036] 126 Outlet opening [0037] 130 Second cooling channel [0038] 150 Connecting hole [0039] 160 Cavity [0040] 162 Edge of the hole [0041] 200 Work machine [0042] 210 Shaft of the work machine [0043] 300 Rod-like tool [0044] 400 Device [0045] 500 Workpiece [0046] L Longitudinal axis of the housing