EP1136183B1 - Diamond grinding segment and grinding tool for surface machining of workpieces - Google Patents

Abstract

The diamond abrasive wheel (116) incorporates a grinding segment (120) which is held on a support body (118). The grinding segment contains a hollow cavity. (122). Either the grinding segment or and the support body contains at east one ventilation duct (152) connected to the cavity in the grinding segment. The grinding segment and support body together are sintered in one piece on a grinding tool (110). The grinding plate (114) rotates on the tool's center axis.

Description

The present invention relates to a diamond grinding wheel for a grinding tool for the surface treatment of workpieces, in particular of natural and artificial stones, in the dry grinding method, according to the preamble of claim 1 and a diamond Schleifwerkzeughierfür according to the preamble of claim 6.

When surface grinding of hard workpieces, in particular of refractory and sanitary ceramics, plan and lattice bricks, natural and artificial stones or hard rock usually diamond pot cutters or full-grinding wheels are used. Often these pot cutters are also used in grinding machines or belt grinding lines. In order to achieve a high level of economy of such grinding tools is sought to achieve the largest possible removal. Due to the high mechanical stress of the workpiece and grinding tool heat is formed, which u. a. dams in the sanding segment. This heat leads to a heating of the abrasive segment and thus to a weakening of the diamond splinters holding binder so that the abrasive segment from a certain temperature can no longer absorb the forces occurring on it and breaks off completely or partially.

From DE-PS 11 20 928 and from DE-PS 562 128 it is known to perform the grinding segments hollow. Even these abrasive segments overheat at the required stress with the above consequences.

From JP 60 048 262 a diamond grinding tool for the surface machining of workpieces is known, are mounted on the sanding pad a number of tubular abrasive body, said abrasive bodies are arranged inclined relative to the rotational axis of the grinding tool, and wherein the cavity of the abrasive body in alignment with a feed channel connects, via which a cooling liquid can be introduced into the interior of the grinding body. However, this coolant must be disposed of consuming and possibly also contaminates the workpiece to be machined. In particular, during the surface grinding of large format or refractory magnesite bricks (Magnesitchrom- and chrome magnesite bricks) moistening of the workpiece is undesirable, as this then again laboriously dried.

Based on this, the object of the present invention is to provide a diamond grinding tool or a diamond grinding tool, in which the occurring heat is well transported away, without the use of a liquid coolant.

As a technical solution to this problem, it is proposed according to the invention to further develop the abovementioned diamond abrasive body in such a way that at least one ventilation channel is provided in the abrasive segment and / or in the carrier body, which is actively connected to the cavity of the abrasive segment.

A trained according to this technical teaching diamond grinding and trained according to this technical teaching diamond grinding tool have the advantage that the air in the cavity can escape through this vent channel to the outside, thus allowing a removal of pent-up heat in the cavity. Hereby, an optimal ventilation of the inner cavity is achieved, so that the heat occurring during grinding both from the outside of the abrasive segment, as well as from the inside of the abrasive segment can be delivered well to the environment, and that the heat is dissipated quickly and easily. The latter leads to further increased removal and grinding performance.

Since now a good heat dissipation is ensured, there is a further advantage that the grinding segment can be formed relatively thin, so that the heat occurring can be transported faster to the surface of the grinding segment and there can be better delivered to the environment. This ensures a much faster heat transfer.

This is particularly advantageous in grinding operations in the dry grinding process, since here the load limit of the grinding segment depends directly on its thermal conductivity.

With a grinding body according to the invention can be achieved in dry grinding similar good material removal and grinding, as hitherto in wet grinding, but with the saving of the coolant. This leads to lower grinding costs, since in addition to the cost of the coolant and the cost of drying the abrasive material can be saved.

In a preferred embodiment, the abrasive segment is integrally sintered together with a carrier body for attachment of the abrasive segment on the grinding tool. This has the advantage that this is a very compact grinding body is created, which can be easily welded or soldered to the designated grinding plates.

In a preferred embodiment, the abrasive segment is composed of two or more sub-segments, wherein the sub-segments are sintered together with the carrier body in one piece. A sanding segment produced in this way has the advantage that the sanding segment can be produced in any desired geometric shape in a simple and cost-effective manner. Another advantage is that the individual sub-segments support each other, so that the forces occurring at the grinding segment are reliably dissipated. Again, the one-piece sintering has the advantage of producing the abrasive segment in a simple and cost-effective manner.

Yet another advantage is that the sintering of the individual sub-segments and / or the carrier body creates a cohesive connection, which absorbs the forces occurring well and non-destructive.

In yet another preferred embodiment, the grinding segment is trapezoidal, triangular or oval. This has the advantage that distributed over the circumference of the sanding pad, a larger number of grinding wheels can be arranged, as a result, the gaps are smaller, resulting in a higher removal.

The orientation of the narrow side of the trapezoid or a tip of the triangle to the central axis out has the advantage that even more abrasive particles can be arranged on the circumference of the sanding pad, resulting in even higher removal.

Another advantage is that the abrasive segment can be formed with much less mass without reducing the front surface critical for the grinding process, resulting in the saving of expensive, diamond splintered abrasive, with approximately the same abrasive effect.

In yet another quite different preferred embodiment, adjacent subsegments have different abrasive concentrations.

A trained according to this technical teaching abrasive article has the advantage that by appropriate choice of the respective concentration, the grinding segment can be performed optimized so that a uniform wear of the abrasive takes place, so that the abrasive body can be much better utilized. This leads to increased service life and lower wear costs of the grinding tool.

Since the arrangement of the abrasive concentration depends greatly on the geometry of the abrasive segment and the application of the grinding tool, the abrasive concentration in each case is determined individually. However, it has proven to be advantageous if in the grinding and / or in the direction of rotation front areas have a higher abrasive concentration, as in the grinding and / or rotational direction behind areas, as a result, a more uniform wear is achieved.

To achieve a high density of abrasive segments on the circumference of the grinding disc, it has proven to be advantageous to align the narrow side to the central axis in the case of a trapezoidal grinding segment and to align the tip to the central axis in the case of a triangular grinding segment. As a result, an even higher grinding performance (removal) is achieved.

In another preferred embodiment, the grinding surface is inclined by 0.5 ° to 60 °, preferably 2 ° to 35 °, with respect to the surface of the workpiece to be ground.

A trained according to this technical teaching grinding tool has the advantage that the forces occurring at the grinding segment by the advance of the workpiece in the thrust direction no longer occur as transverse or bending forces, but are introduced depending on the degree of inclination with a certain axial proportion in the grinding segment. As a result, the risk of aborting the grinding segment is reduced, so that a stronger feed of the workpiece is possible, resulting in a faster machining of the workpiece.

Fig. 1a

eine perspektivische Ansicht eines Teils einer ersten Ausführungsform eines erfindungsgemäßen Schleifwerkzeuges, wobei eine erste Ausführungsform eines erfindungsgemäßen Schleifkörpers explosionsartig herausgezogen dargestellt ist;

Fig. 1b

eine geschnittene dargestellte Teilansicht eines Schleifwerkzeuges gemäß Fig. 1a;

Fig. 1c

eine Untersicht unter das Schleifwerkzeug gemäß Fig. 1a;

Fig. 2

eine perspektivische Ansicht einer zweiten Ausführungsform eines erfindungsgemäßen Schleifkörpers;

Fig. 3

einen Untersicht unter eine dritte Ausführungsform eines erfindungsgemäßen Schleifwerkzeuges;

Fig. 4

einen Untersicht unter eine vierte Ausführungsform eines erfindungsgemäßen Schleifwerkzeuges;

Fig. 5

einen Untersicht unter eine fünfte Ausführungsform eines erfindungsgemäßen Schleifwerkzeuges;

Fig. 6

einen Untersicht unter eine sechste Ausführungsform eines erfindungsgemäßen Schleifwerkzeuges;

Fig. 7a

eine geschnittene dargestellte Teilansicht einer siebten Ausführungsform eines erfindungsgemäßen Schleifwerkzeuges;

Fig. 7b

eine perspektivische Darstellung des Schleifkörpers des Schleifwerkzeuges gemäß Fig. 7a;

Fig. 8

eine perspektivische Ansicht einer achten Ausführungsform eines erfindungsgemäßen Schleifkörpers.

Further advantages of the abrasive article according to the invention and of the abrasive tool according to the invention will become apparent from the attached drawing and the embodiments described below. Likewise, the features mentioned above and those still further described According to the invention, each used individually or in any combination with each other. The mentioned embodiments are not to be understood as an exhaustive list, but rather have exemplary character. Show it:

Fig. 1a

a perspective view of a portion of a first embodiment of a grinding tool according to the invention, wherein a first embodiment of a grinding wheel according to the invention is shown exploded pulled out;

Fig. 1b

a sectional partial view of a grinding tool shown in FIG. 1a;

Fig. 1c

a bottom view under the grinding tool of FIG. 1a;

Fig. 2

a perspective view of a second embodiment of an abrasive body according to the invention;

Fig. 3

a bottom view of a third embodiment of a grinding tool according to the invention;

Fig. 4

a bottom view of a fourth embodiment of a grinding tool according to the invention;

Fig. 5

a bottom view of a fifth embodiment of a grinding tool according to the invention;

Fig. 6

a bottom view of a sixth embodiment of a grinding tool according to the invention;

Fig. 7a

a sectional partial view shown a seventh embodiment of a grinding tool according to the invention;

Fig. 7b

a perspective view of the grinding wheel of the grinding tool of FIG. 7a;

Fig. 8

a perspective view of an eighth embodiment of a grinding wheel according to the invention.

1a to 1c show a first embodiment of a grinding tool 110 according to the invention, in this case a diamond pot cutter, which comprises a grinding plate 114 rotating about a central axis 112, on which a plurality of grinding bodies 116 are detachably screwed. This in Fig. 1a explosively advanced abrasive 116 is composed of a support body 118, preferably made of metal, and attached thereto diamond abrasive segment 120 together, wherein the abrasive segment 120 is formed from a known per se, diamond splitter-containing abrasive.

The grinding body 116 has in its grinding segment 120 a cavity 122 which is arranged coaxially to a longitudinal center axis 126 of the grinding wheel 116. The cavity 122 extends over the entire length of the abrasive segment 120, that is, from the carrier body 118 to a lower abrasive surface 130 of the abrasive segment 120 and exits there to the outside. The grinding segment 120 has a rectangular cross-section and has a recess 132 in the region of the cavity 122, so that the grinding surface 130 resting on the workpiece, not shown here, does not form a closed surface in contrast to the prior art, but rather a rectangular peripheral grinding surface 130 represents.

In the transition to the support body 118, a ventilation channel 152 is formed in the abrasive segment 120 at its narrow sides, through which the air in the cavity can escape to the outside.

By formed in the grinding segment 120 cavity 122, the wall of the abrasive segment 120 is now comparatively thin, in contrast to a fully solid executed grinding segment. By virtue of this thin-walled embodiment of the sanding segment 120, the heat occurring during sanding can be released much better to the environment since the sanding segment 120 now has an outer surface 134 and an inner surface 136 via which the heat can be released to the ambient air. Furthermore, the heat transfer takes place much faster, since due to the thin-walled abrasive segment 120 now less way is covered. Through the venting channel 152, the heat can then be dissipated so that heat build-up does not occur in the abrasive segment 120.

Due to the better heat dissipation, a higher grinding performance is achieved with the grinding body 116, so that a higher removal is achieved with the same feed of the workpiece, although the grinding surface 130 available for grinding is now much smaller.

Except for the formation of a cavity 122 and up to the inventive design of the grinding wheel 116 with ventilation channels 152, the grinding tool shown in FIGS. 1a to 1c corresponds to the grinding tool known from EP 758 573 B1, to which reference is made in full at this point.

As Figure 1 b can be seen very clearly; is the longitudinal center axis 126 of the grinding wheel 116, and thus also the grinding segment 120 and in particular the grinding surface 130 inclined such that forms an angle α between the grinding surface 130 and the surface of the workpiece. In the performance form shown here, the angle α is about 25 °. In other embodiments, not shown here, the angle α can be between 2 ° and 35 °. By the employment of the grinding surface 130 by the angle α, the forces occurring by the advance of the workpiece with a larger axial component are introduced into the grinding segment 120, so that the risk of breaking off parts of the grinding segment 120 is reduced.

The second embodiment of a grinding wheel 216 shown in FIG. 2 largely corresponds to the grinding wheel 116 shown in FIGS. 1 a to 1 c, but has four ventilation channels 252, all of which are operatively connected to the cavity 222 of the grinding segment 220. These vent channels 252 are arranged near the carrier body 218 and formed in the form of a recess in the abrasive segment 220, wherein on each side of the abrasive segment 220, a vent channel 252 is arranged. Through the venting channels 252 more heated air from the interior of the abrasive segment 220 can escape into the open. The abrasive article 216 may also be attached to the abrasive pad 114 of FIG. 1a.

In another, not shown embodiment, only a single venting channel is provided, which is preferably arranged on the viewed in the direction of rotation back of the grinding segment.

The grinding tools 310, 410, 510 and 610 shown in FIGS. 3 to 6 are designed analogously to the previously described grinding tool 110, but differ from one another in the cross section of the respective grinding segment 320, 420, 520, 620. The abrasive segment 320 of the abrasive tool 310 of FIG. 3 is formed in cross-section as a regular trapezoid and the abrasive segment 420 of the abrasive tool 410 of FIG. 4 is formed as an equilateral triangle. In this case, the grinding segment 320 is aligned with its narrow side to the central axis 312 out and analogous thereto, a tip of the triangular abrasive segment 420 to the central axis 412 out.

In the fifth embodiment shown in FIG. 5, the grinding segments 520 of the grinding tool 510 are oval in cross section, while the sixth grinding tool 610 shown in FIG. 6 has a grinding segment 620 of rectangular cross section.

FIGS. 7a and 7b show a seventh embodiment of a grinding tool 710 according to the invention, here a full grinding wheel, in which a grinding plate 714 rotating about a central axis 712 is likewise provided, on which a plurality of grinding bodies 716 are permanently attached. As can be seen from FIG. 7b, this grinding body 716 is composed of a metallic carrier body 718 and a diamond grinding segment 720, which both have the same cross-section and are flush with one another. As a result, a good heat transfer is achieved. Again, a cavity 722 is provided in the abrasive segment 720, while additionally in the carrier body 718, a cavity 724 is provided, both of which are aligned. This abrasive body 716 can be soldered or welded to its carrier body 718 on the grinding plate 714.

In this embodiment, both the cavities 722, 724 and the carrier body 718 and the grinding segment 720 are arranged coaxially about a longitudinal central axis 726, wherein the longitudinal central axis 726 is not arranged parallel to the central axis 712, but inclined by the angle α with respect to the central axis 712. As a result, the grinding surface 730 of the grinding segment 720, which has a recess 732, is inclined by the angle α relative to the surface of a workpiece 738 to be machined. In this embodiment, the angle α is about 10 °. As a result, the forces acting on the grinding segment 720 due to the advance occurring in the direction of the arrow 740 by the workpiece 738 can no longer be introduced only radially, but with a not inconsiderable axial component, so that the risk of damage to the grinding segment 720 due to the feed forces is lowered.

On the side of the grinding body 716 facing the center of the grinding disc 714, a ventilation channel 752 is formed in the carrier body 718 which opens into the cavity 724 and is in operative connection with the cavity 722. As a result, the heat accumulated in the cavity 722, 724 emerge. It is understood that in another embodiment, the vent channel 752 also on another side of the carrier body 718 may be attached and / or that a second venting channel is provided.

The grinding body 916 shown enlarged in FIG. 8 has a grinding segment 920 composed of four subsegments 942, 944, 946, 948, which are all sintered in one piece with the carrier body 916. All four subsegments 942, 944, 946 and 948 are attached to the carrier body 918 so as to enclose the cavity 922 and to leave a recess 932 in the grinding surface 930.

The sub-segments 942, 944, 946, 948 are provided with diamond splinters in a generally known manner. However, the concentration of the diamond splinters in the four subsegments 942, 944, 946, 948 is different, with the forward feed sub-segment 942 and the forward rotational downstream sub-segment 944 having a diamond splitter density of approximately 45% while those in Rotary and Skew Feed direction behind lying lower segments 946, 948 only have a diamond splitter density of about 25%. This takes into account the fact that the sub-segments 942, 944 lying in the direction of movement must provide a higher grinding performance. Due to this fact, the front sub-segments 942 and 944 normally wear more strongly than the rear sub-segments 946 and 948. However, this effect is offset by the different concentration of diamond splinters, resulting in nearly uniform wear of the abrasive segment 920, thus making this abrasive segment longer can be used and why less waste occurs.

The grinding body 916 shown in FIG. 8 also has a venting channel 952 integrated in the carrier body 918, which is in operative connection with the cavity 922 in the interior of the grinding segment 920. This venting channel 952 is limited by two elongated support bodies 918, 919, to which the abrasive segment 920 is applied. It is understood that this grinding body 916 can be attached to the sanding pad 714 of the grinding tool 710 according to FIG. 7a.

LIST OF REFERENCE NUMBERS

110 310 410 510 610 710 grinding tool 112 312 412 712 central axis 114 714; sanding pad 116 216 716 916 abrasives 118 218 718 918 support body 919 support body 120 220 320 420 520 620 720 920 abrasive segment 122 222 722 922 cavity 724 924 cavity 126 726 Longitudinal central axis 128 contact surface 130 730 grinding surface 132 732 recess 134 outer surface 136 palm 738 workpiece 740 arrow 942 subsegment 944 subsegment 946 subsegment 948 subsegment 152 252 752 952 vent channel

Claims (9)

1. A diamond grinding body for a grinding tool for surface machining workpieces using a dry grinding method, with a grinding segment (120, 220, 320, 420, 520, 620, 720, 920) that is retained on a carrier body (118, 218, 718, 918, 919), a cavity (122, 222, 722, 922) being formed in the grinding segment (120, 220, 320, 420, 520, 620, 720, 920),
   characterized in
   that on at least one side of the grinding segment (120, 220, 320, 420, 520, 620), at the transition to the carrier body (118, 218, 718, 918, 919), and/or on at least one side of said carrier body (718, 918, 919), there is provided a vent channel (152, 252, 752, 952) that is operatively connected to the cavity (122, 222, 722, 922) of the grinding segment (120, 220, 320, 420, 520, 620, 720, 920).
2. The grinding body as set forth in claim 1,
   characterized in
   that the grinding segment (120, 220, 320, 420, 520, 620, 720, 920) is integrally sintered together with the carrier body (118, 218, 718, 918, 919) on a grinding tool (110, 310, 410, 510, 610, 710).
3. The grinding body as set forth in any one of the afore mentioned claims,
   characterized in
   that the grinding segment (320, 420, 520) has a trapezoidal, triangular or oval cross section.
4. The grinding body as set forth in any one of the afore mentioned claims,
   characterized in
   that the grinding segment (920) is composed of two or more subsegments (942, 944, 946, 948), said subsegments (942, 944, 946, 948) being integrally sintered together with the carrier body (918, 919).
5. The grinding body as set forth in any one of the afore mentioned claims,
   characterized in
   that the grinding means concentration is provided to be higher in the direction of advance and/or rotation toward the front than in the direction of advance and/or rotation toward the back.
6. A diamond grinding tool for surface machining workpieces using a dry grinding method, having a grinding disc (114, 714) that is disposed for rotation about its central axis (112, 312, 412, 712) and holding a number of diamond grinding bodies (116, 216, 716, 916),
   characterized by
   grinding bodies (116, 216, 716, 916) that are configured as set forth in at least one of the afore mentioned claims.
7. The grinding tool as set forth in claim 6,
   characterized in
   that, if the grinding segment (320) is trapezoid in shape, the small side is directed toward the central axis (312).
8. The grinding tool as set forth in claim 6,
   characterized in
   that, if the grinding segment (420) is triangular, a point is directed toward the central axis (412).
9. The grinding tool as set forth in any one of the claims 6 through 8,
   characterized in
   that the grinding surface (130, 730) is inclined at an angle of 0.5 to 60 degrees, preferably of 2 to 35 degrees, with respect to the to be ground surface of the workpiece (738).

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