EP1475188A2 - Apparatus for finishing plane surfaces - Google Patents

Abstract

Device for fine-machining of flat surfaces of workpieces, especially for surface finishing, comprises a tool (13) with at least two end working surfaces (36, 44) that are provided with cutting agents. The two working surfaces can be axially moved independently of each other and are commonly rotated about a tool axis. Preferred Features: The working surfaces consist of at least one inner and one outer working surface, preferably arranged concentrically to each other.

Description

The invention relates to a device for finishing planes Surfaces on workpieces, especially for finishing planes.

Flat surfaces are made by dry or wet grinding with fast rotating Machined grinding wheels. Finishing with larger ones Flatness and flat lay requirements due to continuous honing sleeves (cup wheels) possible due to their higher degree of coverage enable the desired shape accuracy.

The applicant's DE 202 08 944.4 U describes a machine for Finishing by honing, which also includes a tool with a tapered Grinding head for machining valve seats is shown.

Task and solution

The object of the invention is to provide a device for fine machining to improve flat surfaces to such an extent that they can be used more universally is and enables processing up to high surface quality.

This object is achieved in that the device is a tool with at least two working surfaces covered with cutting agent on the face, which are axially movable independently of one another, but together around a tool axis are rotatable.

These work surfaces, which are preferably arranged concentrically to each other are in the manner of interlocking pot disks be formed and have different cutting agent coverings. For example, the outer work surface can be used for pre-processing coarser and the inner work surface for finishing a finer one Have cutting agent grit.

The tool can be connected to a tool spindle and from be axially movable an axial spindle drive. This can be done by an electric linear motor can be formed which is so finely adjustable that this axial movement adjusts the outer working surface, i.e. the outer cup wheel. The inner cup wheel can be from a running through the drive spindle of the tool Delivery rod can be employed.

A device of the type mentioned at the outset is particularly preferred, as a honing machine with a tool spindle that can be rotated around a spindle axis is formed on which a tool of the previously described Kind is attachable, so that the device for a rotary drive the tool, an axial spindle drive for the tool spindle, e.g. for feeding the outer cup wheel and one into the tool spindle has embedded axial feed drive, for example can deliver the inner cup wheel.

Furthermore, a rotary drive for the workpiece is provided, the one has eccentric workpiece axis of rotation to the spindle axis. This can be a separate device on the workpiece table of the honing machine is built up and integrated into it.

The device preferably works with annular work surfaces with a relatively small ring width compared to the ring diameter.

The cutting speed, which results from a superposition of the peripheral speeds the respective work surface and the workpiece results, is preferably between 1 - 20 m / s. For comparison: The cutting speed for grinding is 30 m / s.

Low contact pressures are used, for example 10-100 N / cm ² , although it is possible that the axial drives that cause the infeed are controlled away, which ensures good dimensional accuracy.

The cutting agent coverings usually contain high-quality cutting grains, such as diamond or boron nitrite, with a grain size of less than 15 μm, preferably at 10µm, which varies, however, whether you want to finish or finish. But also ceramic-bonded cup wheels with corundum or Silicon cutting grains with grain size 300 - 1000 mesh / inch sieve length (mesh) are used. They are particularly porous and self-sharpening.

The intended material removal is usually for the pre-finishing 20µm to 30µm, while only 1µm to 3µm is removed during finish finishing become.

These and other features of preferred developments of the invention go not only from the claims but also from the description and the drawings. The individual characteristics can each individually or in groups in the form of sub-combinations in one embodiment of the invention and in other fields be realized and advantageous as well as protective designs represent, for which protection is claimed here. embodiments the invention are shown in the drawing and are in following explained in more detail.

Brief description of the drawing

Fig. 1

eine Seitenansicht einer eine Honmaschine enthaltende Vorrichtung nach der Erfindung,

Fig. 2 und 3

Längsschnitte durch zwei verschiedene Versionen eines Werkzeuges und

Fig. 4

eine schematische Darstellung der Arbeitsbahnen des Werkzeugs nach Fig. 2.

The drawings show in

Fig. 1

2 shows a side view of a device according to the invention containing a honing machine,

2 and 3

Longitudinal cuts through two different versions of a tool and

Fig. 4

3 shows a schematic representation of the working paths of the tool according to FIG. 2.

Detailed description of preferred embodiments

Fig. 1 shows a device 11, which consists of a honing machine 12 and a built like a special machine, a tool 13 and a workpiece rotary drive 14. The honing machine has a base 15, a machine column 16 and a workpiece clamping table 17 on the base.

A vertical guide 18 for a spindle slide is located on the column 16 19, the headstock 20 of a vertical work spindle 21st wearing.

The spindle slide 19 and the associated spindle guide 18 included the primary and secondary parts of an electric linear motor, so accordingly Stator and rotor of a normal electric motor. This one in the Drawing not shown in detail linear motor 22, the guide 18 and the spindle slide 19 are detailed in DE 202 08 944.4 U. described and illustrated, whereupon for the purpose of description Reference is made.

The headstock supports the axis of rotation about the vertical tool 23 rotatable spindle 21 and contains an electric drive motor (in Fig. 1 indicated by dashed lines) of the rotary drive 24 for the workpiece forms about the axis 23. This rotary drive and possibly also the linear motor can be frequency-controlled synchronous motors whose Regulation via frequency conversion takes place.

On the headstock 20, a feed drive 25 is flanged an electric stepper motor 26 and a rotary / linear converter 27 which has the rotary drive of the stepping motor 26 in an axial movement an delivery rod 28 (see FIGS. 2 and 3). Usually it is a gearbox with a threaded spindle and - nut, which converts the rotation of the motor into exact axial movements. Ball screws etc. can also be used here.

A tool coupling of the spindle is e.g. like a bayonet lock, the tool 13 coupled. The embodiment shown in Fig. 2 has a base body 30, at one end a connecting ring 31 is arranged for the coupling to the spindle. To the other, in the drawing the lower end of the base body is an outer one Tool part 32 attached by means of screws 33. It has the shape of a Cup wheel with a disk-shaped base 34 and a relative narrow outer jacket 35 which towards the free end of the tool protrudes.

The lower end face of the jacket 35 forms the outer working surface 36 of the tool. It is provided with a cutting agent coating 37. This can be made of diamond or boron nitride particles in metallic or other Bond, but also consist of corundum or other abrasives, which as a layer or as a separate annular stone or in Segment shape are applied.

In the space 38, which is inside the pot-shaped tool part 32 arises, a pot-shaped inner tool part 40 is also arranged, which also has a base 41 and a jacket 42. His External dimensions are such that it slides precisely into the outer tool part, i.e. leads on the inner surface of the jacket 35. to more precise guidance can also special storage areas, not shown be provided, which can also be designed to be adjustable. The axial length of the inner tool part is less than the axial depth of the space 38, so that the inner tool part 40 completely in the Space can be withdrawn.

The outer, i.e. lower end face of the shell 42 of the inner tool part 40 forms the inner working surface 44 of the tool. she is also provided with a cutting agent covering 45, which in principle is constructed the same as the covering 37, but usually a much smaller one Grain than this. The inner tool part 40 is with a central feed rod 46, which is in a bore 47th of the base body 30 and the outer tool part 32 leads. The delivery bar 46 is on the feed rod 28, which is inside the tool spindle 21 runs, firmly connected, for example by screwing, so that they precisely control the movement of the delivery rod 28 transmits inner tool part 40 and thus this relative to the outer Tool part 32 can move. The two tool parts 32, 40 are movable axially to each other, but in the direction of rotation with each other connected, namely by an engaging in both base parts 34, 41 Guide pin 49. Here, a tongue and groove guide or the like. be provided.

The tool shown in FIG. 3 is identical to that of FIG. 2, with the exception of the features described below, to the description of which reference is therefore made. The base 34 of the outer tool part 32 is designed as a disk, to which a flange 34 ′ provided on the jacket 35 is screwed from the front side by means of screws 33 ′. The jacket 35 in FIG. 3 has a substantially smaller ring diameter d, but a larger ring width a than that in FIG. 2. Accordingly, the working surface 36 is also wider, but takes up a smaller ring area in diameter. The same applies to the inner tool part 40, which is secured against rotation by a radially extending guide pin 49, which is guided in an elongated hole or slot 51 of the inner tool part.

Fig. 1 also shows that the workpiece rotation drive on the clamping table 14 is arranged. On a base, which may be a cross table for workpiece positioning, an electric motor 54 is arranged, the, possibly via an intermediate gear and a belt drive 55, a chuck rotatable about a workpiece axis of rotation 56 57 drives 58 for a workpiece to be machined. The workpiece has an upper plane surface 60 to be machined. It is also possible the workpiece, e.g. through an additional oscillation drive, one oscillating, superimposing or replacing the rotary movement Issue oscillation.

A coolant / lubricant supply 61 integrated in the machine is included their mouth directed to the surface 60 to be machined.

function

The tool 13 is provided to first finish and then finish the workpiece surface 60 to be machined. For this purpose, the tool is delivered to the workpiece in a position corresponding approximately to FIG. 2, ie with the outer working surface 36 projecting downward, by means of the axial spindle drive 62, which comprises the linear motor 22, first in rapid traverse and then in fine infeed. This is possible directly, but extremely sensitively, using the linear motor, with appropriate sensors being able to limit the infeed. The delivery of the outer work surface is done via the spindle unit. Then the tool and the workpiece are each driven in opposite directions, so that the resulting working speed is in the order of magnitude between 10 m / min and 50 m / min. The overlap shown in FIG. 4 then arises in the case of a tool according to FIG. 2, the outer large ring of the working surface 36 and the inner ring representing the working surface 44. These relatively narrow working surfaces, the ring width a and b of which, even in the tool according to FIG. 3, is only approximately between 1/6 and 1/50 of the ring diameter d , process only one curved strip 65 of the workpiece surface 60, due to the counter-rotation however, the entire workpiece surface is covered by workpiece and tool. In the event that the workpiece has a pin in the middle of the surface to be machined, that is to say only one ring surface is machined, this is also possible and is facilitated by the relatively narrow working surfaces. In this case the spigot would remain outside the outer work surface.

The infeed takes place depending on the path via the linear motor, but could can also be controlled depending on the force. This is done continuously but preferably step by step until the desired level is reached. Processing is wet, i.e. with the addition of coolant-lubricant, e.g. Honing oil or corresponding emulsions from the feed 61st

Thereafter, the outer workpiece part 32 together with the whole Spindle unit retracted slightly in rapid traverse to the front work surface 36 out of engagement with the tool surface and then the inner tool part 40 is advanced by actuation the stepper motor 26 in rapid traverse until the inner work surface 44, the finish work surface, is in engagement with the workpiece surface 60. Accordingly the delivery takes place in much smaller steps, the from a servo motor via the rotary / linear converter 27 to the feed rods 28, 46 transferred and thus mechanically directly to the work surface 44 is transmitted. With delivery in small delivery steps Now the finish-finishing takes place to the desired size and surface quality. It is also possible to have a minimal compliance of the linear motor for infeed and / or axial blocking for equalizing the cutting pressure to use. If necessary, between the pre-finishing and the finishing finishing also the turning speed of tool and workpiece can be adjusted. The feed drive is blocked. This can be done electrically via the linear motor and / or done mechanically.

The function of the tool according to Fig. 3 is identical, only that the Ring width of the work surfaces there is larger than the ring widths a and b 2, in particular taking into account the smaller one in FIG. 3 Diameter d (see Fig. 4).

Through the invention, a tool is created with which be pre-finished and finished in a single setup can. But it is also possible to do different operations one after the other to carry out or, for example, instead of withdrawing the one work surface each, both in one part of the work process To let work surfaces work at the same time. The tool is simple and robustly constructed and can be used on different machines deploy.

A particular advantage is that a normal honing machine, preferably one with a linear drive, but also with others Drive types for which plan finishing can be used. If, for example used a honing machine with hydraulic axial spindle drive pre-finishing could be delivered by this Drive. Then, to achieve the finish finish, the axial spindle drive hydraulically, but preferably mechanically blocked become. It will expand the uses a honing machine created using a simple built tool allows flexible use of the machine park.

Claims (15)

Device for the fine machining of flat surfaces (60) on workpieces (58), in particular for finishing planes, characterized by a tool (13) with at least two working surfaces (36, 44) on the end face, which can be moved axially independently of one another, but together by one Tool axis (23) are rotatable. Apparatus according to claim 1, characterized in that the work surfaces (36, 44) have at least one, viewed in the radial direction, inner and outer work surfaces, which are preferably arranged concentrically to one another. Tool according to Claim 1 or 2, characterized in that the working surfaces (36, 44) are provided on tool parts (32, 40) which are designed in the manner of cup disks and are arranged in a surrounding manner. Device according to one of the preceding claims, characterized in that the tool (13) interacts with a workpiece (58) which is driven to rotate eccentrically to the tool axis (23). Device according to one of the preceding claims, characterized in that the tool (13) can be connected to a tool spindle (21) and is axially movable by an axial spindle drive (62), which preferably contains an electric linear motor (22), and this axial movement the infeed the outer work surface (36). Device according to one of the preceding claims, characterized in that outer and inner work surfaces (36, 44) have different cutting agent surfaces (37, 45), in particular the outer work surface (36) for pre-processing a coarser and the inner work surface (44) for finishing has a finer grain size. Device according to one of the preceding claims, characterized in that the diameter (d) of at least one of the work surfaces (36, 44) is substantially, preferably several times, larger than the workpiece diameter. Device according to one of the preceding claims, characterized in that the working surfaces (36, 44) are annular and have a ring width (a, b) which is less than 1/5, preferably between 1/6 and 1/50 of the ring diameter (i.e. ) is. Device according to one of claims 2 to 8, characterized in that the tool parts (32, 40) are arranged axially displaceably one inside the other and are guided against one another by an anti-rotation device (49, 51). Device according to one of the preceding claims, characterized in that the cutting speed resulting from a superimposition of the peripheral speeds of the respective work surface (36, 44) and the workpiece (58) is between 1 - 20 m / s and 50. Device according to one of the preceding claims, characterized in that it has a feed (61) for the cooling-lubricating liquid to the work surfaces (36, 44). Device according to the preamble of claim 1, characterized in that it is designed as a honing machine (12) with a tool spindle (21) which can be rotated about a spindle axis (23) and on which a tool (13) with at least one cutting-edge-coated working surface (36 , 44) can be attached, the device (11) having a rotary drive (24) for the tool (13), an axial spindle drive (62) for the tool spindle (21) and an axial feed drive (25) preferably embedded in the tool spindle (21) ), wherein a rotary drive (24) for the workpiece (58) is also provided, which has a workpiece axis of rotation (56) eccentric to the spindle axis (23), and wherein the infeed is at least via one of the axial drives (25, 62) of the honing machine (12) takes place. Apparatus according to claim 12, characterized in that the workpiece rotary drive (14) is opposite to the tool rotary drive (24). Apparatus according to claim 12, characterized in that the axial drives (25, 62) work with path-controlled infeed. Device according to one of the preceding claims, characterized in that an inner work surface (44) can be advanced relative to the tool spindle (21) and to the outer work surface (36) by an axial feed drive (25) preferably arranged at least partially in a tool spindle (21) , in particular by means of an infeed rod (28, 46) driven by an electric stepper motor (26) via a rotary / linear converter (27).

Images