JP2729949B2 - Burnishing tool - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burnishing tool used for pressing and finishing a work surface of a work.

[Prior art] Conventional burnishing tools are composed of a large number of steel rollers for processing, a retainer for arranging and holding the steel rollers at appropriate intervals, and a steel track portion for rotating and driving the rollers. Such a processing tool is pressed against the cylindrical peripheral surface, which is the surface to be processed, and the bearing ring is driven to rotate to roll the roller on the surface to be processed, thereby causing plastic deformation on the surface to be processed and causing the surface roughness. In addition to improving the hardness, forming the shape and dimensions to the desired values, and causing work hardening, increasing the surface hardness,
It aims to improve wear resistance, performance, and durability.

[Problems to be Solved by the Invention] However, as a conventional burnishing tool, since the rollers are made of steel, even if the hardness is increased by performing quenching or changing the composition. It cannot be very hard. Therefore, in order to improve the surface roughness, which is the effect of burnishing, to improve the shape and dimension, to improve the surface quality and durability, to increase the effect of plastic deformation and work hardening of the surface to be processed, The hardness of the work piece is not so high, for example, limited to steel and other metals of about H _R C40 or less, for example, hardened steel is used, and H _R C6
It was not very effective for machining cams, bearings and other mechanical parts having a hardness of about 0 or more. In other words, even if it is applied to these hard workpieces, the surface roughness, shape, dimensions, quality and durability cannot be improved very effectively, and the rollers and tracks of burnishing tools can be improved. There have been problems such as deterioration, wear, deformation, galling and the like of the surface.

[Means for Solving the Problems] A burnishing tool according to the present invention includes a plurality of rolling elements having a surface layer portion of a rolling surface formed of a high-hardness ceramic and a high-toughness metal inside thereof, and a plurality of the rolling elements. A retainer for holding,
A tool body having a track portion that holds and rotates the rolling element together with the retainer.

The raceway portion may be formed of a high-hardness ceramic on the raceway surface and a highly tough metal inside.

The metal forming the inside of the rolling element may have a linear expansion coefficient similar to that of the ceramic formed on the surface layer portion, and the metal and the ceramic may be joined.

[Operation] According to the present invention, the surface layer portion of the rolling surface of the rolling elements constituting the burnishing processing tool is constituted by a very high ceramic hardness, the workpiece hardness of more than about H _R C60 Even with hardened steel cams, bearings and other mechanical parts, the surface to be processed is effectively subjected to plastic deformation and work hardening, surface roughness and shape by rolling elements of much higher hardness Improvements in dimensions, surface quality, durability, etc. are effectively performed. In addition, since the raceway surface of the raceway portion of the burnishing tool is made of extremely hard ceramics, the rolling elements do not suffer from inconvenience such as deformation, wear, breakage, etc. due to the large reaction force received when processing. And the durability as a burnishing tool can be increased.

Embodiment 1 A first embodiment will be described with reference to the drawings. 1 is a plurality of rolling elements, 2 is a burnishing tool main body, 3 is a retainer for holding the plurality of rolling elements 1, and a burnishing tool body 2
Is provided with a tapered portion 21 at one end thereof, which is engaged with the spindle 4 of the rotary drive mechanism, and a track portion 22 on which the rolling element 1 rolls is formed at the other end side. Reference numeral 5 denotes a collar for preventing the rolling element 1 from falling off. Surface portion 11 of the rolling surface of rolling element 1
Is made of ceramics such as silicon nitride, zirconia and silicon carbide, and the inside 12 is made of a high toughness material such as hardened steel. The track portion 22 of the burnishing tool also has a surface portion 221 in contact with the rolling element 1, that is, the track surface is made of silicon nitride, zirconia,
It is made of ceramics such as silicon carbide, and its inside 222 and other parts are made of high toughness material such as hardened steel.

By the rotation of the spindle 4 of the rotary drive mechanism, the burnishing tool body 2 is rotationally driven via the tapered portion 21, and at the same time, the rolling element 1 is rotated by the track portion 22. By inserting the burnishing tool body 2 into the inner peripheral processing surface 101 of the workpiece 100, the rolling element 1 rolls on the inner peripheral processing surface 101, and a rolling element having much higher hardness than the processing surface 101. No. 1 gives plastic deformation work hardening and compressive residual stress to the work surface 101 without any wear or plastic deformation, and as a result, the surface roughness, shape, size, surface quality, durability and the like of the work surface 101 are improved. In addition, since the rolling element 1 and the raceway portion 22 are each made of a material having high toughness, even if an impact load or a large load is received during processing, the rolling element 1 and the raceway portion 22 support and absorb the load inside, and the ceramics on the surface layer and the raceway surface are formed. Can be prevented from cracking due to an impact load.

As described above, by using the burnishing tool according to the present embodiment, it has conventionally been difficult to perform effective machining. Burnishing of hardened steel with hardness of about H _R C60 or more can be performed easily and effectively.

In the second embodiment shown in FIG. 3, the burnishing tool includes a plurality of rolling elements 1, a burnishing tool body 2,
It comprises a cage 3 for holding the plurality of rolling elements 1, the rolling elements 1 and the track portions 22 are configured in the same manner as in the previous embodiment, and the spindle of the rotary drive mechanism (not shown) and the main body 2 are engaged. I have. In this embodiment, the rolling elements 1 are arranged at equal intervals on the inner peripheral surface of the raceway portion, that is, on the raceway surface. This rolling element 1
Is engaged so as to cover the outer peripheral portion of the outer peripheral processing surface 102 of the workpiece 100, and when the burnishing tool 2 is driven to rotate, the rolling element rolls on the cylindrical outer peripheral surface which is the processing surface. The machined surface is machined by the same operation as described above, and the same effect as in the first embodiment is expected.

The third embodiment (FIG. 4) is an embodiment for a case where the surface to be processed has a curved groove shape. In this case, the rolling elements 1 in contact with the surface to be processed are spheres made of ceramics such as silicon nitride, silicon carbide, alumina, zirconia, etc. The cage 3 holds the spheres at equal intervals, and the sphere is loaded. The burnishing tool main body 2 having a track portion 22 that supports rolling by receiving the rolling by a curved groove-shaped track portion is engaged with the spindle 4 of the rotary drive mechanism. Also, a curved groove-shaped orbital part on which the ball rolls
Reference numeral 22 denotes an inner part 222 made of steel or an alloy having high toughness and hardness, and a surface part 221 thereof, that is, a track surface, covered with the above-described ceramics.

The operation and effect when the tool is inserted into the inner peripheral surface of the circular groove having a curved groove shape to be processed and processed are the same as those of the first embodiment.

In the fourth embodiment, the processing surface is a flat surface, and although not shown, the rolling element is held and rotated on the end face of the burnishing tool body. When the burnishing tool main body is pressed against the plane to be processed and rolled on the plane, the same effect as in the above embodiment can be obtained.

Although not shown in the drawings, the rolling element 1 according to the present invention, which is in direct contact with the surface to be processed, is not only a roller and a ball, but also a cone, a combination of a cylinder and a cone, and other shapes according to the shape of the surface to be processed. A predetermined rotating body can be used, and the raceway surface of the raceway portion may be configured to have a contour shape corresponding to the contour shape of the rolling body. When the surface layer of the rolling element and / or the raceway surface of the bearing ring is made of zirconia, if the inside is made of steel, the linear expansion coefficients of both materials are almost equal, so that the temperature is raised (or lowered). )
When used in this way, a large thermal stress is not generated at the joint between the two materials, which is advantageous.

[Effect of the Invention] In the present invention, since the surface layer of the rolling surface of the rolling element for machining a burnishing tool is made of extremely hard ceramics, it has a hardness of at least about H _R C60 widely used for industrial purposes. It is possible to burnish hardened steel and other high-hardness members. At that time, the rolling element for processing has a remarkably high surface hardness for the workpiece, so that not only can it be processed with extremely high efficiency, It has a remarkable effect that cannot be obtained by the conventional method in improving the surface roughness, improving the shape and dimension, and improving the surface quality and durability accompanying the processing. For example, when the hardness of the work material is about HrC60 (Hv800), the ceramics is processed by a rolling element having a high hardness of Hv1700 to 3000, and a large value of the compressive residual stress which cannot be obtained with a conventional metal tool and a wide value. Regions are imparted and the degree of work hardening becomes significant, resulting in a marked improvement in durability and wear resistance. At the same time, it has become possible to take a large processing margin, so not only can the processing time be remarkably shortened, but also the surface roughness and shape are remarkably improved. It is also possible to omit it. Furthermore, due to the heat resistance of ceramics and the property of maintaining hardness up to a high temperature range, the effect of preventing the deterioration of processing ability due to heat generated during processing is great, and the non-lubrication (seizure resistance) ability of ceramics is also large. Significantly enhances processing capabilities.

In addition, since the raceway surface of the raceway part of the burnishing tool is made of extremely hard ceramics, it does not cause inconvenience such as deformation, wear, breakage, etc. even by the large reaction force received when the rolling element is processed. This can be absorbed to increase the durability as a burnishing tool.

In addition, when the raceway surface of the rolling surface of the rolling element and the raceway surface of the raceway are made of ceramics and the inside is made of high toughness metal, while having these effects, it is even more resistant to large impact loads during processing. , And can be operated under severe conditions.

In addition, since the rolling element has the same linear expansion coefficient as that of the ceramics in the surface layer and the metal in the inner layer, even when the temperature is increased (or decreased), a large heat is applied to the joint between the two materials. Advantageously, no stress is generated.

[Brief description of the drawings]

1 and 2 show a first embodiment of the present invention. FIG. 1 is a cross-sectional front view, FIG. 2 is a longitudinal side view thereof, and FIG. 3 is a cross-sectional view of the second embodiment. FIG. 4 is a sectional view of the third embodiment. DESCRIPTION OF SYMBOLS 1 is a rolling element, 2 is a burnishing tool body, 3 is a cage, 11
Is the surface layer of the rolling element, 22 is the raceway, 221 is the surface of the raceway, and 222 is the interior of the raceway.

Claims (3)

(57) [Claims] 1. A plurality of rolling elements having a surface layer portion of a rolling surface made of a high-hardness ceramic and a high-toughness metal inside thereof, a retainer for holding the plurality of rolling elements, and a support for holding the rolling elements. A burnishing tool comprising: a tool body having a track portion that is held and rotated together with a container. 2. The raceway portion has a raceway surface made of a high-hardness ceramic,
2. The burnishing tool according to claim 1, wherein the inside thereof is made of a high toughness metal. 3. The metal according to claim 1 or 2, wherein the metal forming the inside of the rolling element has a linear expansion coefficient similar to that of the ceramic formed on the surface layer portion, and the metal and the ceramic are joined. Burnishing tool.