WO2017063770A1

WO2017063770A1 - Device for machining workpieces having a rotating tool

Info

Publication number: WO2017063770A1
Application number: PCT/EP2016/066933
Authority: WO
Inventors: Stefan Engelhardt
Original assignee: Fibro Gmbh
Priority date: 2015-10-12
Filing date: 2016-07-15
Publication date: 2017-04-20
Also published as: EP3362214A1

Abstract

The invention relates to a machining unit (1) for machining workpieces (100), comprising a rotating tool (2). The machining unit (1) comprises a spindle (10) for performing a rotational motion of the tool (2) about an axis of rotation (A) and a piston rod (20) rotatably supported in a bearing shell (30), wherein the spindle (10) is supported in such a way that the spindle is linearly movable and rotationally fixed in relation to the piston rod (20).

Description

Device for processing workpieces

with a rotating tool

Description:

The invention relates to a machining unit for machining workpieces with a rotating tool.

In parts manufacturing, particularly in production lines, increasingly high speed processing steps are implemented by machining units or corresponding devices. So z. B. holes introduced into the workpieces to be machined and provided in a subsequent processing step with a thread. In the field of tool and mechanical engineering, they must be able to be manufactured with sufficient accuracy and speed in consistent quality. Threading or tapping is typically used to create a thread.

Hereinafter, the term thread former is used uniformly for both variants for the sake of simplicity, so that this name should always include the threading. Furthermore, it is known from the prior art that such thread formers are rotationally driven driven into a tapping head. The thread forming head, together with the thread former and a drive unit, e.g. an electric motor, a thread forming unit.

Such thread forming units are attached to the previously made bore in order to introduce a thread.

From DE 202013103426 U1 such an exemplary thread forming unit is known, which is arranged in a press.

It is also known in the automatic parts production, in which presses are used for forming, punching and cutting of the workpieces to use the press with their lifting drive for driving the tapping head. In this case, the oscillating movement of an upper part of the press relative to the static lower part is used in a rotational movement for the rotational drive of the thread former in the thread forming head. DE 10 2008 047 073 discloses for this purpose a device for producing a bore in a workpiece or a thread in a bore of a workpiece, which has a static lower part and a counter to this oscil- With a movable upper part has, with a rotationally drivable Boring- or thread former, and with a device for transmitting the oscillating movement of the upper part in a rotational movement of at least one drive shaft of the drive unit. Further developments to mechanical thread forming units are the electronic thread forming units, which represent an improved variant of the conventionally used mechanical thread forming units. With electronic process monitoring, process reliability is much higher than with conventional devices. By the use of electric motors such. As servomotors together with a controller, which monitor and detect possible process errors through suitable monitoring modules, a much faster process time and higher process reliability can be achieved.

Due to the extremely high process cycles, heat is generated in the process, which in turn can have a negative effect on the result. If necessary, the thread formers can be damaged by overheating, which in turn can lead to consequential damage. To reduce this problem, conventional oil lubrication are used, the z. B. work on the basis of a hose system with spray lance.

In such a system known from the prior art, a certain amount of oil is injected exactly clocked over an oil lance at the given time to the former. But since the thread former is operated at a very high rotational speed, it is problematic to apply the required amount of oil at the right time, in the right place. The application quantity, time and place of application represent process factors that are insufficiently controlled. Due to the high process speed it is very difficult to find the right moment for the lubrication of the thread formers. The problem with too early lubrication is that the oil film applied to the thread former is splashed away again by the high rotational speed before the start of the molding process, or at least partial quantities are undesirably removed by the centrifugal force. Other problems occur when forming deep tubes. Due to the only superficial lubrication of the tube and the former, too little lubricating oil reaches the point to be reshaped. The result is a short life of the thread formers, as they anneal or overheat due to the high temperature. Another problem is the reliable attachment of the lance, as it can easily change their position due to the strong vibrations in the tool.

The invention is therefore based on the object to overcome the aforementioned disadvantages and to provide an improved processing unit, which can be preferably used or implemented in existing processing devices, requires a small space and is reliable in operation.

This object is achieved by a processing unit having the features of claim 1.

The basic idea of the present invention will be explained in more detail below with reference to a processing unit in the form of a threaded head. A first aspect of the present invention therefore relates to the arrangement of a lubricant supply, which according to the invention in the interior of the processing unit that is the thread forming head, is arranged. According to the invention, a lubricant channel is introduced through the thread forming head from a feed side to an application side in the tool for this purpose. The lubricant therefore becomes different from the prior art is not injected via an oil lance to the tool or the thread former, but is applied through the thread forming head along the aforementioned lubricant channel and preferably through a channel in the tool, that is in the thread former, to the desired location.

In this way it can also be ensured that when screwing the thread former into a workpiece, so to speak during the generation of the thread, a desired amount of lubricant can be applied in each case.

A second aspect of the present invention relates to the geometric design of the processing unit, which is an internal installation of the

Lubricant channels through the processing unit allows through. Since the standard seals available on the market are designed either for a radial seal or alternatively for an axial seal, the problem is the proper sealing of both rotational and axially displaceable motion when creating a thread. It is known to be required that when creating a thread with a thread former, the thread former moves both rotationally and translationally. In this respect, two movements are to map and by means of suitable seals to seal the arranged by the processing unit lubricant channels accordingly.

This is achieved according to the invention in that the axially displaceable movement of the thread former is decoupled from the rotational movement of the thread former with respect to the sealing surfaces and seals by providing a piston rod coupled to the spindle for carrying out the axially movable displacement Execution of a rotating movement of the tool about a rotation axis A is driven in rotation and also a in a Lagerscha- le rotatably mounted piston rod is provided, against which the spindle is in turn mounted linearly movable.

According to an anti-rotation means is further provided to transmit the rotational movement of the spindle to the rotatably mounted piston rod. However, since the piston rod moves only rotationally with respect to the bearing shell, the bearing shell can be sealed by means of a radial seal, preferably by means of a radial shaft seal relative to the bearing shell.

On the other hand, the spindle is linearly movable via a plain bearing bush with the piston rod, d. H. coupled axially displaceable. When creating a thread, therefore, the spindle is moved along the piston rod. However, since there is no relative rotational movement between the piston rod and the spindle via the anti-rotation means, it is only necessary to provide a linearly movable seal. For this purpose, an axial seal between the piston rod and the corresponding sealing surface of the spindle is provided.

The invention therefore provides a machining unit for machining workpieces with a rotating, preferably axially displaceable tool, comprising a spindle for carrying out a rotary movement of the tool about a rotation axis and a piston rod rotatably mounted in a bearing shell, against which the spindle is mounted linearly movable.

According to the invention, it is further provided that the spindle is non-rotatably connected to the piston rod by means of an anti-rotation means. In a further advantageous embodiment of the invention it is provided that the anti-rotation means is further formed as a plain bearing bush for the piston rod through which the piston rod is mounted axially movable.

In a further advantageous embodiment of the present invention, it is provided that the anti-rotation means having only partially round passage opening, which with at least one flattened contact surface in the non-round portion, preferably along a circle segment between 20 ° and 60 ° and more preferably between 35 ° and 45 ° is formed. In other words, this means that the piston rod is formed in at least one provided for the sliding portion portion as a cylindrical piston rod with a flattened side surface in the height direction. The flattened side surface serves as a contact surface against the correspondingly formed therefore also flattened contact surface of the anti-rotation. The interacting surfaces are therefore formed comparable to key surfaces.

Since in the preferred embodiment, the anti-rotation means itself is designed as a plain bearing bush, the spindle to which the plain bearing bush is attached to the piston rod only one up and

Abbewegung, but perform no rotary relative movement, but always rotates the piston rod with the spindle.

As alternative embodiments, other forms of encoding or anti-rotation would be conceivable to prevent rotational movement between the spindle and the piston rod and on the other hand to allow a sliding and slipping. So would be a groove in the plain bearing or

Anti-rotation means in conjunction with a corresponding nose on the piston rod in a corresponding shape in the height direction appropriate, a possible alternative.

However, the attachment of a key surface is particularly advantageous since in a particularly suitable manner tolerances and mechanical wear properties can be optimized.

Further preferred is the embodiment of the processing unit with a lubricant supply extending therethrough, which has a lubricant channel for a lubricant which extends at least through the piston rod. It is further preferred if the lubricant channel is further guided through the spindle to the machining tool that is the thread former.

To provide a lubricant channel, for example, the piston rod can be designed as a tubular piston rod which, along its cylindrical longitudinal extension, provides a lubricant channel in the interior over its entire length.

It is also advantageous if a feed opening to a lubricant channel is provided at a housing near end of the piston rod, which is preferably formed with a connection element or a connection adapter for connection to an external supply line for a lubricant. As a result, in a simple way, e.g. a hose with a corresponding corresponding connection adapter are connected to promote lubricant through the lubricant channels to the tool of the processing unit.

According to the invention, it is further provided that a pressure generating device is provided with a controller, whereby a continuous or discontinuous lubricant application can be provided. It is further provided according to the invention with advantage that the spindle forms a cylindrical receiving space into which the piston rod extends with a piston rod section, wherein the piston rod section is formed with an axial seal sealing the receiving space.

To seal the movement is also provided with advantage when the piston rod is sealed by means of a radial seal, preferably a radial shaft seal against the bearing shell. It is also advantageous if the piston rod is rotatably supported in the bearing shell by means of an angular ball bearing or ball bearing.

The machining unit according to the invention is preferably further embodied such that a thread is formed on the outer jacket of the spindle in order to transmit the rotational movement of the spindle by means of a corresponding mating thread in a housing of the machining unit into a translatory, ie axial movement, wherein an axial relative movement between the spindle and the piston rod along the axial seal. In a further advantageous embodiment of the invention, it is provided that the bearing shell is releasably secured to the housing and the piston rod is arranged along its longitudinal extent entirely or at least predominantly in the interior of the housing.

Further advantageous developments of the invention are characterized in the subclaims or are described in more detail below together with the description of the preferred embodiment of the invention with reference to the figures.

Show it:

1 is a side view of an embodiment of a processing unit in the form of a threaded forming head. FIG. 2 shows an open side view of the processing unit according to FIG. 1 without housing; FIG.

Fig. 3 is a sectional view taken along section line A-A through Fig. 2;

4 shows detail B from FIG. 3;

Fig. 5 shows the detail C of Fig. 3; Fig. 6 sectional view through the piston rod of Figure 3 and

Fig. 7 is a perspective view of the anti-rotation means.

In the following, the invention will be explained in more detail on the basis of an exemplary embodiment with reference to FIGS. 1 to 5, wherein the same reference numbers refer to the same functional and / or structural features.

In the present embodiment according to FIGS. 1 to 5, the processing unit 1 represents a thread forming head for producing a thread in a workpiece 100.

As shown in Fig. 1, the thread forming head 1 a housing 3, on which is fastened by means of screws 32, a flange 31 of the bearing shell 30, which is apparent in the lower view of FIG. 1.

Within the housing 3, a piston rod 20 mounted in the bearing shell 30 extends, which can be seen in FIG. The piston rod 20 is rotatably coupled to the spindle 10 via an anti-rotation means 1 1, which is shown in Figs. 3 and 5 in more detail. The anti-rotation means 1 1 is rotatably mounted in the spindle 10 by means of a key surface against a counter surface.

On the outer jacket 15 of the spindle 10, a thread 16 is indicated. The thread 16 cooperates with a corresponding thread (not shown), which is arranged in the housing 3, so that rotational movement of the spindle 10 can take place in a translatory movement along the axis A. According to the direction of rotation in either an upward or a downward movement. In this case, the axis A represents the axis of rotation of the spindle 10.

At the lower end of the spindle 10 is a tool holder 17 for a tool 2, ie a thread former for forming a thread in the present embodiment, in which the processing unit 1 is a Gewin deform head. The spindle 10 has an internal lubricant passage 42 extending from an upper opening 10a to a lower opening 10b. It is surrounded by a cylindrical wall 10c of the spindle 10. In the upper part of the spindle 10, this forms a cylindrical receiving space 14. The receiving space 14 is bounded by a cylindrical inner wall 14 a of the wall 10 c of the spindle 10. Near the upper opening 10a is the aforementioned anti-rotation means 1 1, which is shown in more detail in FIG. As can also be seen in FIG. 3 and in the detail C in FIG. 5, the piston rod 20 with its lower piston rod section 22 plunges into the receiving space 14 of the spindle 10. The end-side section 22a of the piston rod section 22 has a substantially circular shape corresponding to the diameter of the cylindrical receiving space 14, with a peripheral groove 22b into which an axial seal 23 is inserted. During a rotational movement of the spindle 10 about the axis of rotation A, the spindle moves either upwards or downwards along the axis A, depending on the direction of rotation, which carries out a translational movement in which the inner wall 14a is slidably sealed via the axial seal 23.

The piston rod portion 22 of the piston rod 20 shown in more detail in Figure 6 has an outer shell 26 having a shape composed of a pitch circle segment TS and a linear segment L, wherein the linear segment L preferably along a circle segment portion KSA between 40 ° and 80 °, more preferably between 50 ° and 70 ° is formed. In other words, this means that the substantially cylindrical piston rod 20 provides a flattened side surface 27 which abuts against a likewise flattened inner side surface 11 c of the anti-rotation means 1 1, which at the same time a plain bearing bush 1 1 a with a passage opening 1 1 b for the Piston rod 20 forms. The passage opening 1 1 b is formed corresponding to the outer contour of the piston rod 20, so that a translational movement between the piston rod 20 and the plain bearing bush 1 1 a is possible.

Due to the non-circular shape of the cylindrical piston rod 20 in the region of the piston rod portion 22 in cooperation with the corresponding formed as described above bearing bushing 1 1a whose feed-through opening 1 1 b with a corresponding contact surface 1 1c is formed, a relative rotational movement between the spindle 10 and Piston rod 20 prevents and only an axial Translationsbewe- movement along the plain bearing bush 1 1a.

This means that upon rotation of the spindle 10, the piston rod 20 is rotated by the anti-rotation means 1 1 with in rotation and therefore moves with the spindle 10. For this purpose, the piston rod 20 is mounted by means of a ball bearing 25 in the bearing shell 30. On the flange plate 31 of the bearing shell 30 there is a second and third flange plate 33 and 34, respectively. Above the angular contact ball bearing 25 and below the flange plate 34, a radial shaft seal 24 is inserted. This shaft seal 24 ensures its sealing effect even with rotational movements of the piston rod 20. As further shown in the figures, passes through the piston rod 20, a lubricant channel 41 into the receiving space 14 of the spindle 10. The passage from the receiving space 14 of the spindle 10 to the tool holder 17 of the spindle 10 forms a further lubricant channel 42, in conjunction with the aforementioned lubricant channel 41 of the piston rod 20 is. In this respect, lubricant can be transported through the processing unit 1 and indeed along the lubricant channels 41, 42 to the processing tool 17 via a feed opening 43. Preferably, the feed opening 43 is provided with a connection socket 44 to which an external lubricant supply can be connected for supplying a suitable lubricant.

The invention is not limited in its execution to the above-mentioned preferred embodiments. Rather, a number of variants is conceivable, which makes use of the illustrated solution even with fundamentally different types of use.

Claims

claims

Machining unit (1) for machining workpieces (100) with a rotating tool (2) comprising a spindle (10) for carrying out a rotary movement of the tool (2) about an axis of rotation (A) and rotatably mounted in a bearing shell (30) Piston rod (20) against which the spindle (10) is mounted linearly movable.

Machining unit (1) according to claim 1, characterized in that the spindle (10) by means of an anti-rotation means (1 1) rotatably connected to the piston rod (20).

Machining unit (1) according to any one of claims 1 or 2, characterized in that the anti-rotation means (1 1) further as a plain bearing bush (1 1 a) for the piston rod (20) formed by the piston rod (20) is mounted axially movable therethrough.

Processing unit (1) according to one of claims 1 to 3, characterized in that the anti-rotation means (1 1) has an at least partially round passage opening (1 1 b), which with at least one flattened contact surface, preferably along a circle segment between 40 ° and 80 °, more preferably between 50 ° and 70 ° is formed.

Machining unit (1) according to one of the preceding claims, characterized in that a lubricant supply (30) extending through the processing unit is provided, which has a lubricant channel (31) for a lubricant, which at least through the piston rod (20) passes through. Processing unit (1) according to one of the preceding claims, characterized in that a lubricant supply (30) is provided, which is provided with a lubricant passage (32) for a lubricant, which passes through the spindle (10). Machining unit (1) according to one of the preceding claims, characterized in that a feed opening (33) to a lubricant channel (31) is provided at a housing near the end of the piston rod (20), preferably with a connection adapter (34) for connection to an external Supply line is designed for a lubricant. Machining unit (1) according to one of the preceding claims, characterized in that the spindle (10) forms a cylindrical receiving space (14) into which the piston rod (20) extends with a piston rod portion (22), wherein the piston rod portion (22) a the receiving space (14) sealing axial seal (23) is formed. Machining unit (1) according to one of the preceding claims, characterized in that the piston rod (20) by means of a radial seal, preferably a radial shaft seal (24) relative to the bearing shell (30) is sealed. Machining unit (1) according to one of the preceding claims, characterized in that a thread (18) is formed on the outer casing (17) of the spindle (10) in order to control the rotational movement of the spindle (10) by means of a corresponding mating thread in a housing (2). the processing unit in a to transmit axial movement, wherein an axial relative movement between the spindle (10) and the piston rod (20).

1 1 processing unit (1), characterized in that the processing unit is a tapping head. 12 processing unit (1) according to one of the preceding claims, characterized in that the bearing shell (30) on the housing (3) is fixed and the piston rod (20) along its longitudinal extent predominantly in the interior of the housing (3) is arranged. 13 processing unit (1) according to one of the preceding claims, characterized in that the piston rod (20) by means of an angular contact ball bearing (25) is rotatably mounted in the bearing shell (30).