KR20070024587A - Lapping heads for machining workpieces of hard stone material - Google Patents

Abstract

A wrapping head 10 for machining a workpiece of hard stone material is a body that rotates about a vertical axis Y, on which tools 20a, b, c, d, e, f are mounted. (12) and tools (20a, b, c, d, e, f) oscillating about axes arranged radially with respect to the vertical axis (Y) and arranged at equal intervals circularly with respect to each other. The tools 20a, b, c, d, e, and f are divided into two or more tool groups, each group being positioned at a different distance from each of the vertical axes Y in each group. Each group of tools is arranged equidistant from the vertical axis and arranged circularly at equal intervals relative to each other.

Description

LAPPING HEAD FOR MACHINING WORKPIECES OF HARD STONE MATERIALS}

The present invention relates to a lapping head for machining a workpiece of hard stone material, such as granite, porcelain-gres, ceramic material, or agglomerate material made with the Bretonstone technique, wherein the Bretonstone technique is inert. It is obtained by mixing a material, such as silica or quartz, with an organic binder such as a polyester resin, or an inorganic binder such as portland cement.

In the prior art, a lapping head with a vibrating portion, i.e. a body rotating about a vertical axis, and a radial arrangement about the rotating vertical axis, mounted to the body, for polishing the hard stone material, A head is used that includes a plurality of arms that vibrate about a horizontal axis. All arms have the same size, and the tools also have the same size. Thus all the tools are arranged in a circle at the same distance from the rotating vertical axis.

When the head begins to rotate about its vertical axis using actuating mechanisms built into the head, each arm swings about the oscillating radial axis, thus corresponding The tool, or friction portion, also swings, so that during the wear process, a cylindrical cutting profile is maintained.

As a result of the rotating movement of the friction tool about the rotating vertical axis of the head, a lapping / polishing operation is started. Each diamond tool (with a working surface composed of cylindrical parts) swings about the oscillating radial axis and tangential contact of the tool with the machined workpiece is always ensured. During this movement, the circular area in the center of the head is left uncovered so that the arm can oscillate without collision between adjacent tools, and the tool covers in the form of a circular ring.

For further description of the means see Luca Toncelli, Italian Patent 1,247,201 (1991.03.21), or European Patent 647,706 (1994.09.17).

Then, depending on the degree of completion of the requirements of the machined workpiece, the wrapping head is mounted on a machine that is a lapping machine, or a polishing machine.

A wrapping machine includes a workbench having a moving belt on which a material to be wrapped thereon is located and a beam located on the moving belt and arranged parallel to the belt. In an alignment along the beam, a number of rotating spindles are mounted, and at the bottom end of each spindle, as mentioned above, a wrapping head provided with the diamond tool is mounted.

The beam is moved back and forth relative to the belt, and at the same time, each wrapping head begins to rotate about its vertical axis, and each tool swings about the radial axis of vibration. Pressure is applied to the head in the direction of the workpiece to be machined, such that the tool is in contact with the material at a given pressure, and because the swing motion creates a high specific pressure along the tangent of the contact, the tool is rigid. Lapping can be performed on the material of which the wear operation is performed on the hard material.

By the before and after motion of the beam, lapping of the workpiece is generally permitted, in the form of a slab over the entire surface.

Wrapping / polishing techniques are now well established, but defects (even though they may be small) may appear on the polished material.

In particular, near the end or side edges of the workpiece being polished, especially on dark or difficult to wrap materials, defects can be found, for example caused by shadows or bright or dark areas, or by friction tools. There is a small circular groove.

Any such defects are visually perceived, especially by well-trained naked eyes, which will negatively affect the final quality of the finished product. Basically, due to these defects, the finished product may have a partially reduced quality, especially depending on the kind of material and the shade of the color.

The tool must reach the side edges of the slab to be wrapped in order to ensure the wrapping of the workpiece over the entire width, which is within the two end positions estimated by the beam, ie the two points at which the beam movement is reversed. In addition, this problem can be accounted for by reaching beyond the side edges to ensure sufficient coverage of the machined surface.

To do this, however, when the beam reaches the end position, not all tools contact their entirety of the friction surface with the workpiece, and some tools protrude beyond the side edges of the workpiece being machined and are thus completely on the material. Not located.

When all the tools are in contact with the workpiece to be wrapped, the pressure the head exerts on the workpiece is equally offset and balanced by the reaction of the workpiece against the tool. However, when some tools are not in contact with the whole of the machined surface of the workpiece, the pressure in the head is no longer offset-balanced in a uniform and regular manner.

That is, the head tends to "collapse" in terms of which the tool is not completely seated in the material to be wrapped.

Because of this phenomenon, machining no longer occurs in a uniform manner, as a result of which the aforementioned defects may occur.

In addition, at the end position where the beam reverses its movement, it is of utmost importance that the speed of the beam is slowed down, then stopped, and finally accelerated after inverting the movement.

This acceleration and deceleration movement exerts pressure on the head in an unbalanced manner and thus raises the inertia forces that negatively affect lapping / polishing operations. In addition, while the beam is stationary, the tool covers a circular surface portion with the same axis as the head.

In particular, a seizing effect may occur. That is, during deceleration, the head may stop on the workpiece, resulting in a jerking braking action that worsens the condition.

It is therefore desirable to reduce it so that any defects present on the polished material are not completely removed, so that it is not visible to the naked eye and does not affect the quality of the final product.

It is therefore an object of the present invention to devise a new head for wrapping / polishing a workpiece of hard material, in which case the particular design makes the above mentioned defects invisible or hardly discernible by the naked eye. It is to provide a polishing head having.

With a lapping / polishing head for a workpiece of hard stone material, this object can be achieved, the lapping / polishing head comprising a body rotating about a vertical axis, comprising a tool mounted to the body, Each tool swings about an axis arranged radially with respect to the vertical axis, the tools being arranged at equal intervals in a circle with respect to each other. The tool is divided into two or more tool groups, each group located at a distance from the vertical axis, which is different for each group. The tools of each group are equidistant from the vertical axis and are arranged at equal intervals in a circle with respect to each other.

In particular, when the tools are six, they are arranged at equal intervals in a circle to form an angle of 60 ° with respect to each other, and the six tools are divided into two groups, forming an angle of 120 ° with respect to each other. . According to the invention, one group of tools is arranged in a circle smaller than the outer circle and the circle formed by the other group of tools, which allows 120 ° of space between the tools of the same group to collide during their swing movement. This is possible due to the fact that it is prevented.

In this way, the entire working surface of the tool, ie the surface on the workpiece being machined, is no longer concentrated in the outer circle part to form the outer ring shape, but is dispersed in two rings, the outer ring and the inner ring. This greatly reduces the point where the central circular area is not covered by the tool during rotation.

Thus, at the end position where the beam reverses its movement, the tool arranged at a greater distance from the rotating vertical axis of the head is not completely positioned on the surface of the workpiece being machined, but closer to the axis. The locating tool is always in contact with the workpiece.

Therefore, the pressure of the head exerted on the material should be adequately balanced, sufficient to ensure optimal operation of the head and to avoid the risk of stoppage.

1A and 1B show cross-sectional and bottom views, respectively, of a conventional wrapping head and show six tools arranged all on a single outer circle. At this time, a large, exposed central circular area is provided to prevent collisions while the adjacent tools are vibrating.

2A and 2B show a cross-sectional and bottom view of a wrapping red in accordance with the present invention.

The wrapping head according to the invention with reference to FIGS. 2A, 2B will be described. In order to indicate structurally or functionally equivalent elements, the same reference numerals as in FIGS. 1A and 1B are used.

2A and 2B, reference numeral 10 denotes a workpiece of hard stone material (eg, agglomerate material obtained using a Bretonstone technique using a granite, ceramic material, gres, silica, or a quartz-based inert material). Refers to the entire wrapping head for processing.

The wrapping head 10 comprises a box-shaped body 12 having a cylindrical shape that rotates about a vertical axis Y and a plurality of arms 14 mounted on the bottom side. At the lower end of each arm 14 there is a tool-holder 18 on which the diamond coated tool 20 is mounted.

More specifically, the head 10 has six arms 14a, mounted on the body 12, capable of swinging about each of the oscillating axes 16a, b, c, d, e, f. b, c, d, e, f). At the lower side of each arm 14a, b, c, d, e, f, the tool-holders 18a, b, c, d, e, f are respectively held. The diamond tools 20a, b, c, d, e, f are fixed on the tool-holder. The axes of rotation 16a, b, c, d, e, f of the arms 14a, b, c, d, e, f are arranged in a circular manner at equal intervals, i.e., spaced 60 ° from each other. Are arranged.

By means of a rotational movement about axis Y, which is imparted to the wrapping head, drive means 12 for transmitting a swinging movement to each of the six arms 14a, b, c, d, e, f It is embedded in the body 12 of the form. For a more detailed description of this kind of drive means see the patents mentioned above.

The six vibrating arms 14a, b, c, d, e, f are of two types, forming two separate groups, the first group consisting of arms 14a, c, e, The two groups are composed of arms 14b, d, and f. Both groups comprise three arms mounted on the head 10 arranged to be equidistant from the rotational vertical axis Y and equidistantly spaced, forming an angle of 120 ° with respect to each other.

It is essential that the arms of the first group cross with the arms of the second group.

The arms 14b, d, f of the second group have respective tool-holders 18b, d, f having tool-holders 18a, c, e of the arms 14a, c, e of the first group. Tool 20b, d, f supported by the second group of vibrating arms 14b, d, f, so that it is located at a distance from the vertical axis of rotation Y smaller than the distance from the vertical axis of rotation Y of This can also be located at a distance from the axis Y which is shorter than the distance of the tools 20a, c, e supported by the first group of vibrating arms 14a, c, e.

Each group of tools thus forms a radial extension defined by the maximum and minimum distances from the vertical axis Y. The difference in distance between the two arm groups of the tool-holders 18a, b, c, d, e, f from the vertical axis Y is greater than the radial length of the tool 20a, b, c, d, e, f. Because of its small size, an intermediate circular zone, or band, is formed on the workpiece that is the object of operation of the two groups of tools.

In this way, the area at which the tool stops and polishes the workpiece is increased, which ensures a more homogeneous machining even when the tool, which is located at a longer distance from the vertical axis Y, protrudes beyond the side edge of the workpiece. do.

Thus, the workpiece is polished in an optimized manner and no visible surface defects along the side edges of the workpiece are shown.

Any variation or modification of the present invention is possible within the scope of the appended claims.

For example, in particular, when two tool groups are adjacent to each other, an arrangement of one group of tools may be an arrangement of radial extensions that do not partially overlap for another group of tools.

Instead of all having the same spinning length, the tools can have various lengths. For example, tools belonging to each group may have the same length, but the length of one group of tools may be different from that of another group of tools.

Finally, the lapping / polishing head can have different numbers of arms. For example, the heads with nine arms, and thus the nine tools, are arranged at equal intervals in a circle with respect to each other such that they form an angle of 40 ° with respect to each other. The nine arms and tools can be divided into three groups of odd numbers, each group being arranged at a different distance from the vertical axis Y, in this way, each group of tools has an angle of 120 ° relative to each other. They are spaced apart by one another and are arranged at equal intervals in a circle with respect to each other.

Alternatively, nine arms and tools can be divided into two groups, arranged equally spaced at a distance of 40 ° relative to each other, with the first group having three arms and three tools 120 Six arms and six in a second group, arranged equally spaced apart, and spaced in pairs, arranged in pairs to form an angle of 120 ° relative to one another. It is arranged at a smaller distance from the vertical axis Y than the tools.

Claims (8)

In a lapping head 10 for machining a workpiece of hard stone material, the lapping head A body 12 that rotates about a vertical axis Y, on which the body 12 is mounted, on which tools 20a, b, c, d, e, f are mounted, and Tools (20a, b, c, d, e, f) oscillating about an axis arranged radially with respect to said vertical axis (Y), wherein said tools (arranged at equal intervals circularly with respect to each other) 20a, b, c, d, e, f) The tools 20a, b, c, d, e, and f are divided into two or more tool groups, each group being positioned at a different distance from each of the vertical axes Y in each group. A wrapping head for machining a workpiece of hard stone material, wherein the tools of each group are arranged equidistantly from the vertical axis and are arranged at equal intervals in a circle with respect to each other. 2. The tool (20) according to claim 1, wherein the tools (20a, b, c, d, e, f) are arranged at equal intervals in a circle to form an angle of 60 ° with respect to each other. c, d, e, f) are divided into two groups of three tools (20a, c, e and 20b, d, f), so that the tools in each group form an angle of 120 ° to each other. A wrapping head for machining a workpiece of hard stone material, characterized by being arranged at equal intervals in a circle. 3. The workpiece of hard stone material according to claim 2, wherein all the tools belonging to the two groups of tools (20a, c, e and 20b, d, f) have the same radial length. Lapping head for 3. A tool according to claim 2, wherein the tools belonging to each group have the same length, and the length of the tools 20a, c, e belonging to one group is equal to the length of the tools 20b, d, f belonging to another group. A wrapping head for machining a workpiece of hard stone material, characterized by another. 3. The method of claim 2, wherein the distance of the tools 20a, c, e of the group located at a greater distance from the vertical axis Y is such that, in a circular zone having a specified width, frictional motion by the tools of the group is achieved. Hard stone material characterized in that it is superimposed on a portion of the workpiece that is subjected to the frictional motion of the tools 20b, d, f of the group located at a smaller distance from the axis Y. Lapping heads for machining workpieces. 3. The method of claim 2, wherein the distance of the tools 20a, c, e of the group located at a greater distance from the vertical axis Y is such that the frictional work of the tools of the group is located at a smaller distance from the axis. A lapping head for machining a workpiece of hard stone material, characterized in that it is determined not to overlap with the frictional work of the tools 20b, d, f of the group. The tool of claim 1, wherein the tools are nine, arranged at equal intervals in a circle to form an angle of 40 ° with respect to each other, wherein the nine tools are divided into three groups of three tools, each of which is Lapping heads for machining workpieces of hard stone material, characterized in that the tools belonging to the group of are arranged at equal intervals in a circle to form an angle of 120 ° with respect to each other. The tool of claim 1, wherein the tools are nine, arranged equally spaced circularly to form an angle of 40 ° with respect to each other, the nine tools being divided into two groups, three of the first group The tools are arranged in a circle at equal intervals to form an angle of 120 ° with respect to each other, and the six tools of the second group are paired and arranged in a circle at equal intervals to form an angle of 120 ° with respect to each other. And a lapping head for machining a workpiece of hard stone material, characterized in that it is arranged at a distance from a larger vertical axis Y.

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