DE202012003167U1 - milling - Google Patents

Abstract

Milling device, in particular for milling electrode tips of spot welding electrodes, comprising a housing (20; 120) and a milling tool which is accommodated in the housing (20; 120) and can be driven for rotation about an axis of rotation (A) and has at least one machining region (24a, 24b) (22), the housing (20; 120) having at least one chamber (28a, 28b; 128a, 128b) which is open in the direction of the axis of rotation (A) for the introduction and positioning of an object (26a, 26b) to be milled.

Description

The present invention relates to a milling device, in particular for milling electrode tips of spot welding electrodes, comprising a housing and a milling tool accommodated in the housing and drivable for rotation about a rotation axis, having at least one machining area.

Such milling tools for milling electrode tips of spot welding electrode are used in particular in the automotive industry in association with welding robots, which connect body components, for example, by spot welding. In such spot welding operations, the electrode tips of the spot welding electrodes wear out and, therefore, must be milled to ensure consistent quality of the spot welds after predetermined time intervals or a predetermined number of spot welding operations. For this purpose, the spot welding electrodes, which are generally assigned to one another in pairs and are movable towards one another and away from one another, are pivoted into the region of milling devices in which milling tools are rotatably held about a respective axis of rotation. In this case, a rotary drive acts on a tool body, so that it rotates together with a cutting element locked thereto and processed in a respective associated depression in the tool body spot welding electrodes with the or provided on a cutting edge cutting edges, the electrode tips materialabhebend.

In spot welding robots used in production lines, a main focus is on minimizing the travel distances of the robotic arms provided with the spot welding electrodes. For this reason, the operation points, i. H. essentially arranged to be welded body components and the milling device as close to each other. Consequently, the milling device must have a compact design as possible with little interference edges so as not to unnecessarily prolong the distances traveled by a welding robot arm.

It is the object of the present invention to provide a milling device having a compact construction, in particular for milling electrode tips of spot welding electrodes.

According to the invention, this object is achieved by a milling device, in particular for milling electrode tips of spot welding electrodes, comprising a housing and a milling tool accommodated in the housing and drivable for rotation about a rotation axis, having at least one machining area, wherein the housing has at least one open in the direction of the axis of rotation Chamber for introducing and positioning an object to be milled.

By virtue of the fact that the housing has a chamber open in the direction of the axis of rotation for bringing forward and positioning an object to be milled, it is possible, for example, to displace the processing area of the milling tool completely within a chamber. In this way, it is ensured that the milling process takes place substantially inside the housing and that the milling tool itself does not constitute an obstacle to a moving robot arm. Furthermore, with such a housing, a material-saving and thus cost-effective design can be realized.

In a further development of the invention it can be provided that at least one chamber is open in a direction orthogonal to the axis of rotation. In this way, a lateral access to the milling tool can be provided, so that, for example, pliers constructed, pairwise associated spot welding electrodes, they do not have to be moved away from each other before they are then moved back to each other with proper positioning relative to the milling tool to To reach a respective processing area of the milling tool. With such a structure, therefore, the time required for a milling operation can be shortened.

Furthermore, the structure may be such that the milling tool has two processing areas and that a chamber is provided in association with each processing area. In this way it is possible to simultaneously mill two electrode tips, which can lead to a significant reduction in the time required for the milling process in particular pincer-like, pairwise associated spot welding electrodes. Characterized in that a chamber is provided in association with each processing area of the milling tool, can be avoided even with two processing areas having milling tools interfering edges.

In a development of the invention, at least one air inlet opening and at least one air outlet opening can be provided in association with at least one chamber. By providing air inlet openings or air outlet openings, it is possible to produce the milling chips produced during a milling process with a targeted airflow from at least one of the air inlet openings and at least one of the air outlet openings through a chamber out of the chamber dissipate. Furthermore, in this case an air cooling of the milling tool as well as the electrode tip to be milled can be provided.

In order to be able to ensure the most compact possible construction, it can be provided that, preferably in the housing, an air guide arrangement for supplying air to at least one air inlet opening and / or at least one air outlet opening is provided. With such an air guide arrangement for supplying air, for example, a single air connection may be provided on the housing, via which air is directed to at least one air inlet opening and / or at least one air outlet opening. As a result, eleven overall simple structure can be provided. In addition, with a received in the housing air guide arrangement extending outside the housing disturbing lines can be avoided.

In a development of the invention, at least one air inlet opening and at least one air outlet opening can be provided at at least one chamber with respect to the axis of rotation of opposite wall sections of the housing. With such an arrangement, the milling chips produced during a milling process can be removed particularly effectively.

The structure may also be such that at least one air inlet opening is slit-like and / or that a plurality of successive air inlet openings is provided. With such a construction, for example, the geometry of the chamber or of the housing can be taken into account in order to be able to supply air to the milling tool or its processing area in an efficient manner. In this case, air can be uniformly supplied to a wide area of the chamber with a slot-like air inlet opening, for example, while the air supply can be individually adapted with a plurality of successive air inlet openings.

Furthermore, at least one air inlet opening and / or at least one air outlet opening for generating an air flow for discharging milling chips from at least one chamber may be provided. With such an arrangement, for example, the milling tool as well as the electrode tip to be milled can be cooled and at the same time milling chips produced during the milling process can be removed. This allows on the one hand a compact structure, since no additional means for discharging shavings must be provided, and also ensures that there is no malfunction, for example, to a blocking of the milling tool due to accumulating in the chamber milling chips.

In order to be able to ensure that the milling chips produced during a milling process can only leave the chamber through an opening provided for this purpose, an introduction of an object to be milled to the milling tool can be assigned to at least one chamber and an escape of milling chips from the at least one Chamber preventing cover be provided. This may be thought to provide a brush-like cover in a chamber.

In a further development of the invention can also be provided that in association with at least one chamber, the cover is formed by a flat, this chamber sweeping air screen. A cover designed as an air screen has the particular advantage that it is wear-free in contrast to a brush-like cover. At the same time it allows unhindered penetration of a to be milled electrode tip into the chamber and prevents an undefined leakage of shavings from the chamber.

In this case, at least one provided for generating the air screen air inlet opening and / or air outlet opening may also be provided for generating an air flow for discharging shavings. The simultaneous use of provided in association with a chamber air inlet openings and / or air outlet openings for discharging shavings by means of an air flow allows a total of simple construction, since in this case no additional air ducts or air inlet / air outlet openings must be provided.

Furthermore, the construction may be such that the cover comprises at least one cover element which can be fixed, preferably using a quick-release formation, wherein an opening for bringing an object to be milled to the milling tool is provided in association with each machining area. On the one hand, such a cover makes it easy to bring the electrode tip to be milled into the milling tool and at the same time prevents milling chips arising during the milling process, since the opening for guiding the electrode tip to be milled is blocked by the electrode tip itself during a milling operation. Furthermore, a cover element that can be fixed using a quick-release formation allows quick access to the milling tool, for example for maintenance purposes.

In order to be able to provide a stable hold during a milling operation of an electrode tip to be milled, the structure may be such that in association with at least one Processing region is provided a preferably removable retaining element with a holding region opposite the processing area. Such holding elements are required in particular for asymmetrical electrode tips, since due to the forces resulting from the rotation of the milling tool, no center milling position can be maintained otherwise with respect to the axis of rotation of the milling tool. A removable retaining element also allows easy access to the milling tool, for example for maintenance purposes.

Furthermore, it can be provided that at least one air flow recess is provided in the retaining element. In this way, it can be ensured that sufficient cooling air can be supplied to the milling tool or the electrode tip to be milled during a milling operation, and at the same time the milling chips produced during the milling process can be efficiently removed.

In a further development of the invention it can be provided that, preferably in the housing, a drive gear for transmitting a driving force between a drive unit and the milling tool is provided. With a drive gear it is possible, for example, to overshoot or reduce a rotational speed provided by a drive unit as a function of the electrode tip or the degree of deposition on the electrode tip, so that optimum milling can be ensured.

It can be provided that an axis of rotation of a drive shaft of the drive unit is orthogonal to the axis of rotation of the milling tool. With such an arrangement, the milling device can be positioned in the immediate vicinity of the drive unit, in particular in a milling tool having two machining areas, since an object to be milled can be guided in a direction orthogonal to the axis of rotation of the drive shaft to the milling tool and the drive shaft itself thus does not constitute an obstacle.

The structure may be, for example, such that the drive gear comprises a bevel gear and a ring gear meshing with the bevel gear, preferably with a central opening for receiving the milling tool. Such a drive gear allows a compact design, especially when is added in the already flat ring gear of the milling tool in a central opening.

Although the above reference has been made to spot welding electrodes as objects to be milled, it will be understood that the present invention is not limited to these, but is applicable to milling any objects.

The present invention will be explained in more detail below with reference to the attached figures. It shows:

1 an electrode milling arrangement with a milling device according to the invention in a perspective view,

2 a perspective view of a drive unit, a milling device and a container for receiving shavings,

3 a top view of a milling device according to the invention,

4 one of the 3 corresponding plan view of a holder provided with a milling device,

5 a sectional view along the line VV in 4 .

6 a plan view of an alternative embodiment of a milling device according to the invention, and

7 a perspective view of the in 6 shown milling device according to the invention.

In 1 is a common with 10 designated electrode milling arrangement shown. This includes a milling device 12 , designed as an electric motor drive unit 14 and a support element 16 at which the milling device 12 , the drive unit 14 as well as a collection container 18 are mounted for collecting shavings arising during a milling process.

In 2 are the drive unit 14 and the milling device 12 as well as the collection container 18 shown enlarged. The milling device 12 includes a housing 20 as well as in 3 to 5 shown in the housing 20 recorded and driven for rotation about a rotation axis A milling tool 22 , The milling tool 22 has two processing areas 24a . 24b for simultaneous milling of two electrode tips 26a . 26b on. The milling tool 22 is a drive shaft, not shown here, designed as a motor drive unit 14 driven for rotation. The housing 20 includes two in the direction of the axis of rotation A of the milling tool 22 open chambers 28a . 28b for guiding and positioning the electrode tips to be milled 26a . 26b , In the in 3 to 5 illustrated embodiment, the two chambers 28a . 28b through a cover 30 covered. With the help of the cover 30 On the one hand, it is possible to prevent milling chips arising during a milling process from being undefined from the chambers 28a . 28b exit and on the other hand becomes one Leading a to be milled electrode tip 26a . 26b to the milling tool 22 allowed.

The z. B. made of flexible plastic material cover 30 includes in association with each chamber 28a . 28b a cover area 32a . 32b , being assigned to each chamber 28a . 28b one opening each 34a . 34b for bringing the electrode tips to be milled 26a . 26b to the milling tool 22 is provided. The cover 30 is in this embodiment using a snap closure formation 36 on the housing 20 fixable and thus allows quick access to the milling tool 22 For example, for maintenance purposes.

The housing 20 further comprises an air outlet opening 38 in an air outlet element 39 which also for discharging resulting in a milling chip shavings in the collection 18 is provided.

How out 3 to 5 recognizable, is also assigned to the chamber 28a an air inlet opening 40a at a nozzle 41a provided. The air inlet opening 40a stands with an air duct arrangement 42 for supplying air. The air duct arrangement 42 is intended by a single on the case 20 provided air connection 44 both the air inlet opening 40a as well as the air outlet opening 38 To supply air. Likewise, this is the second chamber 28b associated air inlet opening 40b Air supplied (see 5 ). The air outlet opening 38 includes a plurality of air outlets 46 (please refer 5 ). These are in the air outlet element 39 arranged running towards each other, so that by the thus provided nozzle effect, the milling chips produced during a milling process effectively to the collecting container 18 can be dissipated. The flow direction S is in 5 illustrated by arrows.

The milling tool 22 is in an opening in this embodiment 48 a crown wheel 50 taken, which with a bevel gear 52 is in mesh and together with the bevel gear 52 a drive gear 54 forms. Due to this configuration, the rotation axis B of the drive shaft of the drive unit 14 orthogonal to the axis of rotation A of the milling tool 22 ,

In the 4 shown representation of the milling device 12 is essentially the same as the 3 , In addition to the basis of the 3 discussed elements of the milling device 12 is in 4 in association with the milling tool 22 a holding element 56a shown which in association with the editing area 24a a passage opening 58a for an electrode tip to be milled 26a having. The holding element 56a indicates in association with the air inlet opening 40a and the air outlet 38 respective air flow recesses 60a . 60a on. These air flow recesses 60a . 60a ' allow efficient air supply to or air removal from the processing area 24a of the milling tool 22 , As in 4 are shown, the respective Luftströmungsausnehmungen 60a . 60a ' formed asymmetrically to the relative arrangement of the air inlet opening 40a and the air outlet 38 Take into account. As in 4 shown is the retaining element 56a with respect to the passage opening 58a Also designed asymmetrically, so that it only in a single, clearly defined mounting position in the chamber 28a can be positioned. In this way it is ensured that the passage opening 58a in the chamber 28a positioned holding element 56a just above the editing area 24a lies. Like also out 4 can be seen, the retaining element 56a by means provided thereon locking sections 59a on the housing 20 be determined. In the present embodiment, the chambers are 28a . 28b also open in a direction B orthogonal to the axis of rotation A, so that the corresponding holding elements 56a . 56b can be inserted in a direction B orthogonal to the axis of rotation A.

In 5 is a cross-sectional view along the line VV in 4 shown. Again 5 it can be seen in association with each chamber 28a . 28b one holding element each 56a . 56b intended. Also the chamber 28b associated holding element 56b has two air flow recesses 60b . 60b ' and a passage opening 58b on. Furthermore, in the in 5 shown representation of an electrode tip 26a to the editing area 24a or an electrode tip 26b to the editing area 24b introduced.

Like the same 5 it can be seen, is the air outlet opening 38 both chambers 28a . 28b assigned. The air flow direction S through the plurality of Luftausströmöffnungen 46 is shown schematically with two arrows. With the help of these Luftausströmöffnungen 46 becomes one of the two chambers 28a . 28b away leading air flow generated, which ensures efficient removal of Fräsvorgang resulting Fräspänen.

In the 6 and 7 an alternative embodiment of a milling device is shown, which substantially corresponds to the first embodiment. Therefore, in the 6 and 7 analog parts provided with the same reference numerals, but increased by the number 100 , In addition, the embodiment according to 6 and 7 in the following will be described only insofar as they differ from the embodiment according to FIG 1 to 5 which is expressly referred to herewith.

The in the 6 and 7 shown milling device 112 has two chambers according to the first embodiment 128a . 128b on. The differences from the first embodiment will be described below only with reference to the chamber 128a explained.

In the in the 6 and 7 shown second embodiment of the milling device 112 are with respect to the axis of rotation A of a milling tool not shown opposite wall sections 162a . 164a of the housing 120 a plurality of air inlet openings 140a or / and a louvre 140a ' intended. This can be a the chamber 128a can be formed sweeping umbrella, which acts as a cover, so an approach leading to be milled electrode tip to the milling tool and at the same time prevents spillage arising during a milling chip. This structure also has the advantage that in this way an air flow for the targeted removal of shavings can be generated, whereby a total of compact design can be realized. In addition, a trained as an air cover cover is wear-free and allows, for example, for maintenance purposes, a quick access to the milling tool.

Claims (17)

Milling device, in particular for milling electrode tips of spot welding electrodes, comprising a housing ( 20 ; 120 ) as well as in the housing ( 20 ; 120 ) and for rotation about an axis of rotation (A) drivable, at least one processing area ( 24a . 24b ) having milling tool ( 22 ), the housing ( 20 ; 120 ) at least one in the direction of the axis of rotation (A) open chamber ( 28a . 28b ; 128a . 128b ) for bringing and positioning an object to be milled ( 26a . 26b ) having. Milling device according to claim 1, characterized in that at least one chamber ( 28a . 28b ; 128a . 128b ) is open in a direction (B) orthogonal to the axis of rotation (A). Milling device according to one of the preceding claims, characterized in that the milling tool ( 22 ) two processing areas ( 24a . 24b ) and that in association with each processing area ( 24a . 24b ) a chamber ( 28a . 28b ; 128a . 128b ) is provided. Milling device according to one of the preceding claims, characterized in that in association with at least one chamber ( 28a . 28b ; 128a . 128b ) at least one air inlet opening ( 40a . 40b ; 140a . 140a ' ) and at least one air outlet opening ( 38 ; 138 ) are provided. Milling device according to claim 4, characterized in that, preferably in the housing ( 20 ; 120 ), an air guiding arrangement ( 42 ; 142 ) for supplying air to at least one air inlet opening ( 40a . 40b ; 140a . 140a ' ) and / or at least one air outlet opening ( 38 ; 138 ). Milling device according to claim 5, characterized in that at least one chamber ( 128a ) at least one air inlet opening ( 140a ; 104a ' ) and at least one air outlet opening ( 138 ) with respect to the axis of rotation (A) opposite wall sections ( 162a . 164a ) of the housing ( 120 ) are provided. Milling device according to one of claims 4 to 6, characterized in that at least one air inlet opening ( 140a ' ) is slot-shaped and / or that a plurality of successive air inlet openings ( 140a ) is provided. Milling device according to one of claims 4 to 7, characterized in that at least one air inlet opening ( 40a . 40b ; 140a . 140a ' ) and / or at least one air outlet opening ( 38 ; 138 ) for generating an air flow for discharging shavings from at least one chamber ( 28a . 28b ; 128a ) is provided. Milling device according to one of the preceding claims, characterized in that in association with at least one chamber ( 28a . 28b ; 128a ) an introduction of an object to be milled ( 26a . 26b ) to the milling tool ( 22 ) and a discharge of milling chips from the at least one chamber ( 28a . 28b ; 128a ) preventing cover ( 30 ) is provided. Milling device according to claim 9 and one of claims 4 to 8, characterized in that in association with at least one chamber ( 128a ) the cover by a flat, this chamber ( 128a ) sweeping air screen is formed. Milling device according to claim 10, characterized in that at least one provided for generating the air screen air inlet opening ( 140a . 140a ' ) and / or air outlet ( 138 ) is also provided for generating an air flow for discharging shavings. Milling device according to claim 9, characterized in that the cover ( 30 ) at least one, preferably using a rapid closure formation ( 36 ), fixable cover element ( 32a . 32b ) in association with each processing area ( 24a . 24b ) an opening ( 34a . 34b ) for bringing an object to be milled ( 26a . 26b ) to the milling tool ( 22 ) is provided. Milling device according to one of the preceding claims, characterized in that in association with at least one processing area ( 24a . 24b ) a preferably removable retaining element ( 56a . 56b ) with a processing area ( 24a . 24b ) opposite holding area ( 58a . 58b ) is provided. Milling device according to claim 13 and claim 8 or 11, characterized in that in the holding element ( 56a . 56b ) at least one Luftströmungsausnehmung ( 60a . 60a ' . 60b . 60b ' ) is provided. Milling device according to one of the preceding claims, characterized in that, preferably in the housing ( 20 ), a drive gear ( 54 ) for transmitting a driving force between a drive unit ( 14 ) and the milling tool ( 22 ). Milling device according to claim 15, characterized in that an axis of rotation (B) of a drive shaft of the drive unit ( 14 ) orthogonal to the axis of rotation (A) of the milling tool ( 22 ). Milling device according to claim 15 or 16, characterized in that the drive gear ( 54 ) a bevel gear ( 52 ) and one with the bevel gear ( 52 ) meshing ring gear ( 50 ), preferably with a central opening ( 48 ) for receiving the milling tool ( 22 ).

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