EP1741515A1 - Tool - Google Patents

Abstract

The machining tool has a circular disc (2) connected to a bracing plate. The circular disc and the bracing plate has a coupling (20) and a counter coupling having walls (23) formed of alternating convex wall sections (24) bent inwards towards the central axis (10) and the concave wall sections (25) bent outwards away from the central axis. The maximum radius of the convex and concave wall sections of the coupling is smaller than the maximum radius of the convex wall and the concave wall sections of the counter couplings, respectively.

Description

The invention relates to a tool with a support member and a disc-shaped working part for machining.

Such tools, in which a support member or a base body is respectively connected to a working part, which is a wearing part, are known in various embodiments. Such working parts are, for example, abrasives on a base, polishing wheels and needled nonwoven with embedded abrasive existing cleaning discs or felt discs. Support member and working part are driven in rotation. In known embodiments, a coupling part with nut thread is attached to the working side opposite side, which is screwed onto a thread of a support member. In general, the connection and release of the working part of the support member is tedious or time consuming or can be accomplished only with great care. This is disturbing because such workpieces very often need to be replaced after only a short period of use. Especially in such a case, the stack height of the working parts is very large, since the coupling part with the female thread inevitably has a considerable height.

From the EP 1 007 282 B1 It is known to attach a sheet-shaped abrasive to a magnetized carrier. For this purpose, the abrasive has a ferromagnetic metal foil. This is not suitable for tools of the type described above.

The invention is therefore based on the object to design a tool of the general category so that the manufacture and release of the Connection between support member and working part is very fast and easy to carry out.

This object is achieved by the features of claim 1. The essence of the invention is that the working part is placed on the support member, wherein the very flat coupling part of the working part is inserted into the counter-coupling part of the support member. By a simple rotation through a small angle of the locking edge engages in the annular groove, whereby an axially fixed connection between the working part and the support member is made. Regardless of the direction in which the working part is rotated relative to the support member, there is a torque-fixed connection between the working part and the support member, since the first convex wall portions of the coupling part come into tangential contact with the second concave wall portions of the counter-coupling part to the plant. The torque-fixed connection is advantageously made so that the working part is rotated relative to the support member against the rotational drive direction of the support member to the tangential contact with each other. The working part is then in a circumferential position relative to the support member, which also occupies it during labor.

The claims 2 to 4 give advantageous developments of the torque-resistant connection between the working part and support member again.

The provided according to claims 5 and 6 magnets serve as a mounting aid, since after the abutment of the working part and the supporting part of a certain axial securing or fixing is already achieved. On the other hand, it is ensured that in the case of a quick stop, the tool, the working part, due to its inertia, although from the Torque-resistant connection can solve, but remains axially connected to the support member.

The claims 7 ff. Give advantageous developments of the working part and support member again.

Fig. 1

eine Draufsicht auf ein Arbeitsteil mit Kupplungsteil eines Werkzeugs,

Fig. 2

eine Draufsicht auf ein Tragteil mit Gegen-Kupplungsteil des Werkzeugs und

Fig. 3

eine perspektivische Schnitt-Darstellung durch das Tragteil mit Arbeitsteil in Explosionsdarstellung.

Further features, advantages and details of the invention will become apparent from the following description of an embodiment with reference to the drawing. It shows:

Fig. 1

a top view of a working part with coupling part of a tool,

Fig. 2

a plan view of a support member with counter-coupling part of the tool and

Fig. 3

a sectional perspective view through the support member with working part in an exploded view.

The tool shown in the drawing consists in its basic structure of a support member 1 in the form of a support plate and a working part 2. The support member 1 has a holding body 3, to which a support plate 4 is molded from rubber. This support plate 4 is provided with extending from the inside to the outside cooling channels 5, which are separated from each other by means of also extending from the inside to the outside ribs 6. The cooling channels 5 are connected at their inner end in each case via an air inlet opening 7 on the back 8 of the support plate 4 with the atmosphere. The back 8 opposite upper sides of the ribs 6 define a contact surface 9 for the working part 2. This Design of the support plate 4 with cooling channels 5 is in the DE 10 2004 009 443 A illustrated and described, to which reference is made.

In the holding body 3, in turn, a receiving body 11 is arranged concentrically to a common central longitudinal axis 10, which is non-rotatably connected to the holding body 3 or else rotatably connected. Concentric with the axis 10, a drive bushing 12 is again arranged in the receiving body 11, which is provided with an internal thread 13. In this inner thread 13, a drive shaft 14 of a tool drive, not shown, by means of a corresponding external thread 15 is screwed. Such tool drives may be so-called angle-grinding machines or straight-grinding machines. The receiving body 11 and the drive socket 12 are connected by means of a ring nut 16 in the direction of the axis 10 and fixed against rotation about the axis 10 against each other and secured.

The actual working part 2 is circular disk-shaped and has a counter-abutment surface 17, which comes to rest against the abutment surface 9 when the working part 2 is attached to the support part 1. The working part 2 has approximately the diameter of the support part 1. In the present case, the working part 2 is formed by an abrasive 18 on pad 19, wherein the counter-abutment surface 17 is formed on the side facing away from the abrasive 18 side of the pad 19. Such abrasive 18 on pad 19 are usually not stiff, so elastically resilient, formed.

On the working part 2, a coupling part 20 is attached, which is connectable to a counter-coupling part 21 on the support member 1. The coupling part 20 has a flange 22 which is glued to the base 19 of the working part 2. It also has an approximately parallel to the central axis 10 extending wall 23, which - seen from the axis 10 to the outside - alternately bent inwardly from the axis 10 towards curved concave wall sections 24 and away from the axis 10 outwardly convex wall portions 25 is formed. The concave and convex wall sections 24, 25 are arranged alternately and merge into each other continuously. In each case a concave wall section 24 and an adjacent convex wall section 25 extend over a circumferential angle of 60 °. Each section 24 or 25 extends over a circumferential angle a or b of about 30 °.

At the end facing away from the flange 22 of the wall 23 an inwardly projecting locking edge 26 is formed on this, which has an inner hexagonal opening 27.

The counter-coupling part 21 has a wall 28, which likewise has alternating concave wall sections 29 and convex wall sections 30, which likewise merge into one another continuously and in each case a concave wall section 29 and an adjacent convex wall section 29. Section 30 extends over a circumferential angle of 60 °. Each individual wall section 29, 30 extends over a circumferential angle c or d of 30 °. The wall 28 is formed as an inner wall in the receiving body 11.

The drive bushing 12 is provided at its end located within the wall 28 with an extension in the form of an outer hexagon 31, which is adapted to the inner hexagon opening 27 such that the coupling part 20 with its inner Six-edge opening 27 with little play over the outer hexagon 31 can be pushed. Immediately below this external hexagon 31, a ring groove 32 is formed in the drive bushing 12, in which the locking edge 26 engages after a sliding over the locking edge 26 via the outer hexagon 31 after rotation, whereby the coupling part 20 with the counter-coupling part 21 in the direction of the central longitudinal axis 10 is firmly locked. In principle, the openings 27 and the approach should have a polygonal cross-section.

The maximum radius R _{25 of} the convex wall portions 25 and the minimum radius R _{24 of} the concave wall portions 24 of the wall 23 are measured from the central longitudinal axis 10 to the outer surface of the wall 23. On the other hand, the maximum radius R _{30 of} the convex wall portions 30 and the minimum radius R _{29 of} the concave wall portions 29 of the wall 28 are measured from the central longitudinal axis 10 to the inner surface of the wall 28. The maximum radius R _{25 of} the convex wall portions 25 is smaller than the maximum radius R _{30 of} the convex wall portions 30.
The following applies: R ₂₅ <R ₃₀ .
Furthermore, the minimum radius R _{24 of} the concave wall sections 24 is smaller than the minimum radius R _{29 of} the concave wall sections 29.
The following applies: R ₂₄ <R ₂₉ .
Furthermore: R ₂₅ > R ₂₉
The clearance between the wall 23 of the coupling part 20 and the wall 28 of the counter-coupling part 21 is relatively small; it is in the range of 0.1 to 0.3 mm.

In this respect: $$0.1\mathrm{}\mathrm{mm}\le {\mathrm{R}}_{30}-{\mathrm{<figure-callout\; id="25"\; label="R"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">R</figure-callout>}}_{25}\le 0.3\mathrm{}\mathrm{mm}\mathrm{}\mathrm{and}\mathrm{}0.1\mathrm{}\mathrm{mm}\le {\mathrm{R}}_{29}-{\mathrm{<figure-callout\; id="24"\; label="R"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">R</figure-callout>}}_{24}\le 0.3\mathrm{}\mathrm{mm},$$

This has the consequence that after the described insertion of the coupling part 20 in the counter-coupling part 21 and after rotation of the coupling part 20 against the counter-coupling part 21 by about 15 °, the convex wall portions 30 of the counter-coupling part 21 and the concave Wall sections 24 of the coupling part 20 abut each other, whereby a torque-fixed connection between the coupling part 20 and the counter-coupling part 21 is provided. The twisting movement is thus about half the circumferential angle a, b, c, d. The inner hexagon opening 27 and the outer hexagon 31 are arranged so as to coincide with each other when the coupling part 20 is pushed into the counterpart coupling part 21.

The production of the coupling connection is effected by a rotation of the working part 2 with the coupling part 20 against the drive direction of rotation 33, so that the torque connection is maintained during operation of the tool.

In a flush with the ring groove 32 bottom surface 34 of the counter-coupling part 21 permanent magnets 35 are arranged, which hold the existing ferromagnetic material locking edge 26 of the coupling part 20 in the direction of the axis 10. These magnets 35 are used to hold this during assembly of the working part 2 on the support part 1, so that the described twisting movement for producing the lock between the coupling part 20 and the counter-coupling part 21 only by the rotary drive of the tool when it is used can be done. Furthermore, the magnets 35 serve to the working part 2 am To keep support member 1 at a quick stop of the prime mover, since due to the inertia of the rotating working part 2 unlocking by rotation of the working part 2 relative to the support member 1 in the direction of rotation 33 can be done. A release of the working part 2 from the support member 1 in the direction of the axis 10 is then prevented by the magnets 35. In the support member 1 holes 36 are formed, through which a suitable tool for releasing the support member 1 can be inserted from the drive shaft 14 respectively.

Claims (10)

Tool
with a supporting part (1),
with a disc-shaped working part (2) for machining, and
with a common center axis (10),
the support part (1) having a contact surface (9) for the working part (2),
wherein the working part (2) has a counter-abutment surface (17) for the contact surface (9),
wherein the working part (2) concentric with the central axis (10) has a coupling part (20) with a wall (23) formed of alternately arranged and merging first concave wall sections (24) and first convex wall sections (25) .
wherein the support part (1) concentric to the central axis (10) a counter-coupling part (21) adapted to the coupling part (20) with an alternately arranged and merging second concave wall sections (29) and second convex wall sections ( 30) formed second wall (28) for receiving the coupling part (20),
the coupling part (20) concentric with the central axis (10) having a locking edge (26) with an opening (27) of polygonal cross-section arranged inside the first wall (23),
wherein the counter-coupling part (21) concentric with the central axis (10) has a shoulder adapted to the opening (27) in cross-section and at this a the locking edge (26) adapted annular groove (32),
wherein the first concave wall section (24) has a minimum distance (R ₂₄ ) from the central axis (10), the first convex wall section (25) has a maximum distance (R ₂₅ ) from the central axis (10). the second concave wall section (29) has a minimum distance (R ₂₉ ) from the central axis (10) and the second convex wall section (30) has a maximum distance (R ₃₀ ) from the central axis (10). have, where: $${\mathrm{R}}_{25}<{\mathrm{R}}_{30}.$$

$${\mathrm{R}}_{24}<{\mathrm{R}}_{29}$$

and $${\mathrm{R}}_{25}>{\mathrm{R}}_{29},$$

Tool according to claim 1, characterized in that $$0.1\mathrm{}\mathrm{mm}\le {\mathrm{R}}_{30}-{\mathrm{R}}_{25}\le 0.3\mathrm{}\mathrm{mm}$$

and or $$0.1\mathrm{}\mathrm{mm}\le {\mathrm{R}}_{29}-{\mathrm{R}}_{24}\le 0.3\mathrm{}\mathrm{mm},$$

Tool according to claim 1 or 2, characterized
in that the opening is formed as an inner hexagonal opening (27) and the projection as an outer hexagonal (31). Tool according to one of claims 1 to 3, characterized
that in each case a first concave wall section (24) and a neighboring first convex wall section (25) and a second concave wall section (29) and a neighboring second convex wall section (30) each extend over a circumferential angle of 60 ° extend. Tool according to one of claims 1 to 4, characterized
that in the counter-coupling part (21) permanent magnets (25) are arranged, which are assigned areas of ferromagnetic material on the coupling part (20). Tool according to claim 5, characterized in that
in that the permanent magnets (35) are arranged in a bottom surface (34) of the counter-coupling part (21), which is formed flush with the ring groove (32). Tool according to one of claims 1 to 6, characterized
that the supporting part (1) a support plate (4) and having an at least partially enclosed by this holding body (3). Tool according to one of claims 1 to 7, characterized
that the supporting part (1) has a connection for a rotary drive. Tool according to one of claims 1 to 8, characterized
that the working part (2) as a grinding means (18) is formed on the liner (19). Tool according to one of claims 1 to 9, characterized
that the support plate (4) consists of an elastically yielding material.

Images