JP2006136985A - Shaft finishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft finishing method capable of effectively performing not only small lot multi-production but also finish of a heat-treated article, and reliably obtaining a finished surface without any remaining spirally turned groove. <P>SOLUTION: In a shaft 1 of a stepped shape which is subjected to the heat treatment of hardening and tempering, a small diameter shaft part 2 and a medium diameter shaft part 3 are turned by a wiper tip 10. The turning is completed on the medium diameter shaft part 3 under the finishing condition that no spirally turned groove is present while leaving a margin of several μm. Thereafter, the step is changed, the medium diameter shaft part 3 is turned by using a wrapping film to remove the remaining margin, and to eliminate the turned groove. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for finishing a shaft surface with high accuracy and high efficiency.

  Conventionally, in order to finish a shaft surface with high accuracy and high efficiency, plunge grinding in which a grinding wheel is fed in the radial direction of the shaft while rotating the shaft has been generally used. However, according to this plunge grinding, a dedicated grinding wheel that matches the dimensions and shape of the shaft is required, so the grinding wheel must be replaced (changed) each time the shaft type is changed. However, the recent production line, in which small-lot production of various varieties is generalized, has a problem that a reduction in the line operation rate is inevitable.

  Therefore, for example, in the device described in Patent Document 1, the above-described problem is addressed by replacing grinding with a grinding wheel with turning with a turning tool. However, according to this measure, spiral turning grooves remain on the finished surface, so when high surface accuracy (no grooves) is required, the standard cannot be satisfied, and its application range (product type) is It will be limited.

  In addition, as a method for obtaining a smooth finished surface, there is a turning method using a wiper tip having a cutting blade that is parallel or slightly inclined to the finished surface (for example, see Patent Document 2). The remainder of the turning groove cannot be completely eliminated, and no fundamental measures can be taken.

In addition, as a method for obtaining a smooth finished surface, there is a method in which a lapping film to which abrasive grains are bonded is pressed against a rotating shaft and ground (see, for example, Patent Document 3), but the allowance for this lapping film is small. Yes (about several μm), usually, when heat treatment products (quenched and tempered products etc.) for which a machining allowance of several hundred μm is set are targeted, the use must be abandoned.
JP-A 63-34314 JP 2003-117717 A JP 2004-268163 A

  The present invention has been made in view of the above-described technical background, and can effectively cope with finishing of heat-treated products as well as low-volume production of various products, and can reliably obtain a finished surface having no spiral turning grooves. It is an object of the present invention to provide a finishing method for a shaft that can be used.

  In order to solve the above-mentioned problems, the present invention is characterized in that after the shaft surface is turned while leaving a machining allowance in a minute range with respect to the final finished dimension, the machining allowance is ground by a lapping film.

  In the shaft finishing method performed in this way, it is not necessary to change tools even if the type of shaft is changed by combining turning and grinding with a lapping film. In addition, since turning is performed first, even heat-treated products with a large machining allowance can be efficiently finished. Further, in the present invention, the machining allowance in the minute range is about several μm (for example, 1.5 to 3 μm). Since the final machining allowance is very small in this way, the machining allowance is sufficiently ground by the lapping film. can do. Furthermore, the helical turning groove formed by the previous turning process can be surely eliminated by grinding with the lapping film.

  According to the finishing method of the shaft according to the present invention, in addition to being able to effectively cope with finishing of heat-treated products as well as high-mix low-volume production, it is possible to reliably obtain a finished surface without a spiral turning groove, Its utility value is great.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

  In the present embodiment, the small-diameter shaft portion 2 and the medium-diameter shaft portion 3 are finished for the stepped shaft 1 shown in FIG. The absence of grooves is the finishing condition (quality assurance condition). Further, the shaft 1 is preliminarily quenched and tempered, and the small-diameter shaft portion 2 and the medium-diameter shaft portion 3 have a relatively large machining allowance with respect to the finished surface S as shown in FIG. S1 (as an example, about 0.15 to 0.20 mm) is attached.

  In this embodiment, first, the small diameter shaft portion 2 and the medium diameter shaft portion 3 of the shaft 1 are continuously turned by the wiper tip 10 as shown in FIGS. For the above, the entire machining allowance S1 is deleted and finished to a predetermined size, while the medium diameter shaft portion 3 has a small machining allowance S2 of about several μm (for example, 1.5 to 3 μm). The stock allowance S1 is deleted. Next, the process is shifted, and the medium diameter shaft portion 3 is ground by the lapping film 20 as shown in FIG. 3, and the machining allowance S2 remaining in the turning process is deleted. The part 3 is finished to a predetermined dimension.

As shown in FIG. 2, the wiper tip 10 used in the turning process is linearly inclined with respect to the finishing surface S, and the linear cutting edge 11 arranged at an angle substantially perpendicular to the finishing surface S. The cutting edge 11 is connected to the cutting edge 11 and the cutting edge 12. In addition, as the wiper chip | tip 10, there exists a thing which made the blade a gentle arc shape, and this invention may use what has such an arc-shaped blade. Moreover, since the grade of the wiper tip 10 used here is intended for the shaft 1 having a high hardness (for example, H _R C60) subjected to heat treatment, a material made of a hard material as much as possible is used. In this case, examples of the hard material include artificial diamond, various types of ceramics such as cubic boron nitride (CBN), silicon nitride (Si ₃ N ₄ ), and alumina (Al ₂ O ₃ ). It is desirable to select CBN considering the durability and durability.

  In the turning by the wiper tip 10, a helical turning groove 4 (FIG. 1) is formed on the machining surfaces (surfaces to be turned) of the small diameter shaft portion 2 and the medium diameter shaft portion 3. However, the turning groove 4 is remarkably shallow as compared with turning with a general-purpose tip that does not have the countersink 12, and as a result, the unevenness formed on the processed surface is small as shown in FIG. 2. That is, according to the turning with the wiper tip 10, a machined surface with excellent surface accuracy can be obtained. As an example, the surface roughness of the processed surface by the wiper chip 10 is about 1.5 to 2.0 Rz, and here, the target surface roughness of the small-diameter shaft portion 2 is sufficiently satisfied. Therefore, even if the small-diameter shaft portion 2 is finished to the target dimension only by turning with the wiper tip 10, there is no problem in quality.

  On the other hand, as shown in FIG. 3, the grinding process using the lapping film 20 is performed only on the medium-diameter shaft portion 3 of the shaft 1 after the turning process. One side of the wrapping film 20 is bonded with abrasive grains having an appropriate size (for example, a particle size of 60 to 80 μm). The wrapping film 20 has one side with the abrasive grains bonded to the hollow shaft portion 3. It is extended and arranged in a direction perpendicular to the axis 1 so as to come into contact. At the time of grinding, the wrapping film 20 is pressed by the pressing member (shoe) 21 with a predetermined load F against the medium-diameter shaft portion 3 of the shaft 1 that is rotationally driven by the driving means. As a result, the machining allowance S2 (FIG. 2) remaining on the medium diameter shaft portion 3 is deleted, and the medium diameter shaft portion 3 is finished to a predetermined dimension. Further, by this grinding, the spiral turning groove 5 (FIG. 1) formed in the turning step is eliminated, and a finished surface having a smooth and excellent surface accuracy can be obtained. Note that the wrapping film 20 is normally drawn from the supply reel and wound on the take-up reel, and the new abrasive grain surface is successively formed after each processing or is interrupted during the processing. Provided for processing.

  In the grinding process, the wrapping film 20 may be oscillated (oscillated) in the axial direction of the shaft 1 together with the pressing member 21, and in this case, a grinding pattern is formed in a cross hatch shape on the finished surface, The surface accuracy is further improved.

  Further, during the grinding, the wrapping film 20 may be continuously fed (paid out) during grinding. In this case, the grinding efficiency is improved because the grinding process is always performed with a new abrasive surface. The grinding process can be completed in a short time.

It is a side view which shows typically the turning process of the front | former stage of the finishing method of the axis | shaft which concerns on this invention. It is sectional drawing which shows the turning condition by the wiper tip in this turning process. It is a side view which shows typically the latter grinding process of the finishing method of the axis concerning the present invention.

Explanation of symbols

1 shaft 3 medium diameter shaft (no turning groove)
10 Wiper chip 20 Wrapping film

Claims (3)

  A shaft surface finishing method comprising: turning a shaft surface while leaving a machining allowance in a minute range with respect to a final finishing dimension, and grinding the machining allowance with a lapping film.   2. The surface finishing method for a shaft according to claim 1, wherein turning is performed with a wiper tip. The shaft finishing method according to claim 1, wherein grinding is performed while the wrapping film is oscillated.

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