JP6902882B2 - Grindstone for grinding spiral deformed materials - Google Patents

Description

The present invention relates to a grindstone for grinding a spiral-shaped profile, and in particular (but not necessarily) a grindstone for grinding a spiral-shaped profile of a recirculating ball screw. Regarding.

As is well known, the spiral trajectory for rotating the ball in the recirculating ball screw coupler results in a high pressure and requires high machining accuracy, so that the trajectory needs to be ground frequently. ..

Grinding is usually done using a monolithic grindstone with uniform particles and structure, with the same grindstone, with the same parameters, positioning the parts in the same way, with roughing and finishing steps. Whetstone. A compromise to obtain the final roughness and required accuracy for the threads at the expense of processing time so that there is no excessive extension of the thread shaft that would adversely affect the required accuracy and quality. It is clear that we need to find a point.

Alternatively, a first grindstone with a larger particle size is used to define the roughing action and a second grindstone with a smaller particle size is used to finish the track.

A well-known grinding process includes a first step of grinding with a roughing grindstone, and once this process is complete, the roughing grindstone is replaced with a finishing grindstone and the track This process is repeated until the finishing of the grindstone is completed.

It is also known to grind a spiral track pair, which forms a so-called "double thread" by using a double disc grindstone. A first roughing process is defined by a first double disc grindstone made from a material with a larger particle size, which is then replaced with a smaller grain size finish grindstone. The grindstone for finish cutting also has two discs arranged side by side with each other.

Such interventions have the disadvantage of long execution times, as they need to provide at least two passes (one for rough cutting and one for finish cutting).

In addition, during the finish-shaving process, the grinding wheel heats up to the point where the geometric arrangement of the deformed material is locally deformed, which can result in the loss of the original correct shape.

In this regard, a technical object of the present invention is to provide a grindstone for grinding a spiral deformed material that overcomes the above-mentioned drawbacks.

Specifically, an object of the present invention is to provide a grindstone for grinding a spiral deformed material, which is suitable for achieving better working efficiency.

A further object of the present invention is to provide a grindstone for grinding a spiral deformed material having optimum geometric stability in use.

Such technical objectives and the stated objectives are substantially achieved by a grindstone for grinding a spiral deformed material having the technical features described in one or more of the accompanying claims.

The present invention will be described below with reference to the accompanying drawings illustrating embodiments of the invention, but the invention is not limited to the following embodiments.
The figure which looked at the grindstone which concerns on this invention in the operation composition for grinding the spiral shape material of a recirculation type ball screw from two different angles. The figure which looked at the grindstone which concerns on this invention in the operation composition for grinding the spiral shape material of a recirculation type ball screw from two different angles. The figure which shows the outer profile of the grindstone of FIG. 1 in detail. It is a figure which shows the cross section in the axial direction of the outer deformed material of the grindstone of FIG. 1 in the operation composition for grinding a spiral deformed material of a recirculation type ball screw.

In the attached drawings, the grindstone for grinding the spiral deformed material according to the present invention is shown as a whole by reference numeral 1.

The grindstone 1 is used to grind a spiral track (a plurality of spiral tracks in the case of two or more threads) arranged on a recirculating ball screw. The purpose of grinding is to reduce friction and increase the reliability of the connection so that the ball slides optimally and efficiently in the orbit.

As shown in FIGS. 1 and 2, in the grindstone 1, the relative rotation axis “X” is substantially parallel to the rotation axis “Y” of the screw 2, and in particular, the spiral deformed material (or spiral trajectory) of the screw 2 is provided. ) Arranged so as to incline at an angle substantially equal to the spiral angle of 3. Further, the grindstone 1 is in contact with a deformed material of at least two grooves 4a and 4b adjacent to the track 3, whereby grinding is performed.

More specifically, the grindstone 1 has two arch-shaped outer polishing deformed members 5 and 6 which have a shape symmetrical with respect to the axis "X" of the grindstone 1 and are arranged side by side in the axial direction. In the processing step, these two outer deformed members 5 and 6 are introduced into the grooves 4a and 4b adjacent to the track 3. During the machining cycle, the grindstone 1 is synchronized with the rotation of the screw 2 and thus in the supply direction "A" in synchronization with the ideal supply of the respective grooves 4a and 4b along the axis "Y". It moves along the axis "Y" of the screw 2.

The two outer abrasive profiles 5 and 6 form, at least substantially, two coaxial disks 1a and 1b that form the moving part of the grindstone 2, but two outer abrasive profiles. The materials are tightly connected to each other so that the grindstone 1 forms a single fixed mass.

In the following description, the two discs 1a and 1b correspond to the case where the two outer polishing deformed materials 5 and 6 are simply described.

According to a unique aspect of the present invention, the two discs 1a and 1b have different polishing properties such that the degrees of surface finish cutting of the grooves 4a and 4b are different.

The polishing discs 1a and 1b are preferably made of a ceramic type polishing material.

According to this preferred embodiment, the rough cutting disk is formed by the first disk 1a arranged in the front direction of the supply direction "A" of the grindstone 1 with respect to the spiral track 3, and the other disk 1b is used. A disc for finish cutting can be formed.

More specifically, the two discs 1a and 1b have different particle sizes and / or different types of abrasives (abrasive) and / or different densities and / or structures, and the surfaces of the grooves 4a and 4b. The roughness values will be different. According to an embodiment, the rough cutting disc has a particle size of 80 to 100, while the finish cutting disc 1b has a particle size of 120 to 140.

Further or alternatively, the two discs 1a and 1b may have different structures and / or binders from each other, and the first disc 1a provides a roughing effect while the second disc 1a. The disc 1b of No. 1 provides an effect of different surface roughness such that an effect for finish cutting is obtained.

According to the modified embodiment, one of the polishing discs 1a and 1b, preferably the polishing disc 1a for rough cutting, is made of a ceramic material, and the other polishing disc 1b is made of rubber.

According to a further advantageous aspect of the present invention, in the first embodiment (not shown), the two polishing discs 1a and 1b are connected to each other by reversible connecting means.

For example, reversible connecting means include one or more connecting screws.

In another embodiment, the polishing discs 1a and 1b are permanently connected to each other, for example, a single molding process or the like to obtain a grindstone 1 having a single integrated structure. That is, in this solution, the grindstone 1 is formed by a single mass obtained by a single molding process, and the two discs are formed so as to permanently and irreversibly overlap.

Alternatively, the polishing discs 1a and 1b are permanently connected to each other by bonding.

According to a further advantageous aspect of the present invention, the polishing discs 1a and 1b have outer deformed materials that are geometrically different from each other in a cross section along a plane passing through the rotation axis X of the grindstone 1. In particular, according to a more preferred embodiment, the finish-cutting disc 1b has a nominal outer profile corresponding to the laterally shaped grooves 4a and 4b to be formed, while the rough-cut disc has a rough-cut disc. It has a corrected outer deformed material having a corrected geometric shape with respect to the laterally deformed material of the grooves 4a and 4b to be obtained.

In use, the two discs 1a and 1b (ie, the two outer-polished variants 5, 6) engage in the respective grooves 4a and 4b adjacent to the spiral orbit 3 of the screw 2. Next, the screw 2 rotates around the rotation axis "Y", and at the same time, the grindstone 1 rotates around the relative axis "X", and the grindstone 1 is supplied along the axis "Y" of the screw 2. , A permanent engagement between the grindstone 1 and the spiral orbit 3 with different stretches, especially in the continuum of the spiral orbit 3, is obtained.

As a result, the roughing disc 1a operates on the first stretch of the spiral orbit 3, while the finishing disc 1b is the second of the spiral orbit 3 already roughed by the roughing disc 1a. Form a stretch finish shaving.

This operation preferably forms a recessed feed and feed region with respect to the spiral orbit 3, or instead accommodates a finish-cutting disc 1b in the feed region and a rough-cut disc in the feed region. Is possible on a screw 2 such that it has additional threads in the feed and feed regions to accommodate 1a.

Although the present invention has referred to screws having a spiral trajectory for recirculating ball screws, the present invention is also applicable to many other solutions, including female threads, trapezoidal threads, ACME threads, (sharpened). There is a spiral deformed material to be ground, such as a screw thread of a part such as a tapping tool. For this reason, in the present embodiment, the two outer-polished deformed materials have a curved shape that substantially follows the spiral trajectory for the ball to be obtained, but these outer-polished deformed materials have other shapes ( For example, it may have a trapezoidal shape).

According to the present invention, the above object is achieved and the shortcomings of the prior art are overcome.

According to the grindstone 1 according to the present invention, a complete process (roughing + finish cutting) can be achieved in a single course, the working time is greatly reduced, and moreover, as has occurred in the prior art. It is possible to avoid the positioning problem when replacing the grindstone for rough cutting with the grindstone for finish cutting.

Further, according to the structure of the grindstone according to the present invention, the heat capacity and the ability to dissipate heat to the outside are improved, the problem of heating is reduced, and the problem of dimensional irregularity of the deformed material after grinding is eliminated. ..

Claims (10)

A grindstone for grinding a spiral deformed material, which includes a first polishing disk (1a) and a second polishing disk (1b) arranged side by side and arranged coaxially, and the two disks are described above. (1a, 1b) are firmly connected to each other, and in each disc, the two polishing discs (1a, 1b) are two grooves of at least one spiral deformed material (3) of the mechanical part (2). The two discs (1a, 1b) have different peripherally polished deformed materials (5a, 5b) that engage inside (4a, 4b), and the two discs (1a, 1b) have different surface roughness of the grooves (4a, 4b). have a different polishing characteristics, such as the level, from said first and ceramic material grinding disc (1a) to form a coarser level of the second grinding disc (1b) is made of rubber, the grinding wheel .. The grindstone according to claim 1, wherein one of the two polishing discs (1a and 1b) is a rough cutting disc (1a) and the other disc is a finishing cutting disc (1b). The grindstone according to claim 1 or 2 , wherein the two polishing discs (1a, 1b) are connected to each other by a reversible connecting means. The grindstone according to claim 3 , wherein the reversible connecting means includes one or more connecting screws. The grindstone according to claim 1 or 2 , wherein the two polishing discs (1a, 1b) are connected to each other by a permanent connecting means. Claim 1 or 2 , wherein the two polishing discs (1a, 1b) form a single integral structure that is obtained by a single molding process or is permanently connected to each other by bonding. Grindstone. Any of claims 1 to 6 , wherein the two polishing discs (1a, 1b) are arranged relative to each other so as to grind the corresponding adjacent grooves (4a, 4b) of the mechanical component (2). The grindstone according to item 1. The abrasive disc (1a, 1b) is, in transverse cross-section along a plane passing through the rotation axis (X) of said grinding wheel (1), having mutually geometrically different outer profiles, of claims 1 to 7 The grindstone according to any one of the items. The disc (1b) has a nominal outer deformed material corresponding to the laterally deformed material of the grooves (4a, 4b) formed so as to obtain a lower surface roughness, that is, to be a finish cut. However, the disk (1a) is configured so that a higher surface roughness can be obtained, that is, a rough cut, and the geometry of the groove (4a, 4b) to be obtained is corrected for the laterally deformed material. The grindstone according to claim 8 , which has a geometric shape and has a corrected outer deformed material. A method for grinding a spiral deformed material of a machine part, the first of the discs (1a, 1b) using the grindstone (1) according to any one of claims 1 to 9. One disk (1a) is arranged in the front direction of the supply direction (A) of the grindstone (1) with respect to the spiral deformed material (3), and the first of the spiral deformed material (3). At the same time, the other disc (1b) is used to grind the second stretch of the spiral deformed material (3) that has already been rough-cut by the first disc (1a). The way it is done.

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