JPS60141462A - Grinding of cylindrical member - Google Patents

Abstract

PURPOSE:To obtain considerably accurate finish with no reduced effective width of cut by forming on a work surface annular grooves each having a depth substantially equal to the depth of cut and grinding the remaining work surface up to the depth of cut of the grooves. CONSTITUTION:A pair of plate type grinding stones 18, 18 are mounted to a grinding stone mounting surface 16 of a grinding stone support 14 of a holder 10 at both ends thereof, arranged with a width equal to an effective width of cut, and have cutouts 22 of a curvature corresponding to the radius of a work rod 20. The grinding stones 18, 18 are pressed against the peripheral surface of the work rod 20 rotating in the direction indicated by an arrow A to form at both ends of a strip work surface 30 a pair of annular grooves 34, 34 having a depth equal to the depth of cut of the work surface 30, and a finishing grinding stone fixedly secured to the support and having a concaved abutting surface of a curvature corresponding to the radius of the work rod 20 is pressed, with oscillation, against the strip work surface 30 between the grooves 34, 34, which can be cut up to a depth equal to that of the grooves 34 with a high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for grinding a circular body such as a cylinder or a cylindrical body, and more specifically, the present invention relates to a method for grinding a circular body such as a cylinder or a cylindrical body. The present invention relates to a method for grinding a circular body in which a relief groove is formed and the relief groove is erased during oscillation grinding.

Conventional methods for grinding cylindrical bodies, cylindrical bodies, etc. include traverse grinding, plunge grinding, and oscillation grinding. Among these, oscillation grinding is a method in which either the workpiece or the grinding wheel is reciprocated relative to the longitudinal direction with a relatively short stroke, and the surface to be processed can be ground with high precision and high efficiency. . Therefore, it can be said that this method is particularly suitable for grinding ultra-hard materials with high precision.

For example, if we explain the conventional technology related to automobiles, the following methods have been adopted so far.

In other words, as a result of increased engine output and rotational speed,
The load on the bearings is also increasing. For this reason, it is necessary to improve the finishing accuracy of not only the bearing metal but also the shaft supported by the bearing metal, and to increase the load capacity of the bearing. As a result, after the normal grinding, the machined shaft is subjected to a super-finishing process using methods such as paper lapping, a combination of paper lapping and chromium oxide polishing, or polishing with a finishing whetstone to improve the metal contact between the shaft and bearing. I have been trying to

However, it has been extremely difficult to create a shape with excellent precision using paper wrap or chemical grinding.

In order to avoid these difficulties, oscillation grinding as described above has been adopted for bearings, but this method also has the following problems. That is, when pressing a grindstone against the peripheral surface of a rotating processing shaft to grind the peripheral surface of the processing shaft, sufficient shape accuracy of the processing surface cannot be obtained unless the grindstone performs oscillation grinding in the direction of the processing axis.

However, when oscillation is applied to the grindstone, the boundary between the band-shaped processed surface and the non-processed surface becomes unclear, and an inclined portion (sag) that cannot be used effectively is created between the two.

As described above, since superfinishing using a grindstone improves shape accuracy by over-heeling or oscillating the grindstone, the conventional method has the disadvantage that the effective shaft width is reduced. This is a big problem, especially in the case of engine crankshafts that are subjected to very heavy loads.

Therefore, the inventors of the present invention have conducted extensive research in order to find a method for machining circular objects by oscillation grinding, which takes advantage of the advantage of machining with a grindstone in that a highly accurate shape can be obtained, and which does not reduce the effective machining width. As a result of overlapping, if a clearance groove approximately equal to the grinding width is formed in advance between the processed surface and the non-processed surface, and the depth is set to less than the processing depth, it is possible to eliminate the drawbacks of the two conventional finishing methods. It has been revealed that the ideal shaft finishing method that eliminates sagging is jXf.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a finishing method for a shaft that has high shape accuracy and does not reduce the width of J machining. More specifically, the object of the present invention is to provide a finishing method for a circular body that takes advantage of the high load applied by the grindstone and does not reduce the effective machining width.

In order to achieve the above object, the present invention presses a grindstone against a rotating workpiece grinder, and causes the grindstone to make a minute reciprocating motion in a direction substantially perpendicular to the rotational direction of the workpiece. In the grinding method of grinding the machined surface of the workpiece with the grindstone, the step of forming an annular groove on the machined surface with a depth substantially equal to the processing depth of the grinding process, and It is characterized by consisting of a process of grinding the remaining machined surface until it reaches the final stage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, with reference to preferred embodiments and apparatus for carrying out the invention.

1 Fig. 1 shows a plate-shaped grindstone used for grinding grooves.
It consists of 4. A pair of plate-shaped grindstones 18, 18 are held at both ends of the grindstone mounting surface 16 of the grindstone support portion 14. These plate-shaped grindstones 18,18 in this case have a width W approximately equal to the effective grinding width and are provided with a notch 22 of a curvature corresponding to the radius of the machining axis 20 (see FIG. 2).

Next, a method of forming grooves in advance on two shafts using this plate-shaped grindstone, 18.18, will be described.

As shown in FIGS. 2 and 3, this holder 1
0 into the four parts 26 formed on the grindstone head 24 of a cylindrical grinder (not shown), and rotate in the direction of the arrow 7.
It is pressed against the circumferential surface 28 of the processing shaft 20 that is being held. At that time, a minute oscillation is generated in the axial direction B perpendicular to the rotational direction A.
It is very appropriate to give.

In this way, the belt-shaped machining surface 30 of the machining shaft 20 and the non-machining 1
A pair of annular grooves 34 are formed at the boundary of the kiNi 32, at the zunawa, and at both ends of the processed surface 30. Note that the depth of the groove 34 is set to a value substantially equal to the machining depth of the machining surface 30.

Next, with reference to FIGS. 4 to 7, a finishing whetstone for oscillating grinding the band-shaped processed surface 30 sandwiched between the grooves 34 will be described. Boulder 36 is 1, insertion part 38
and a grindstone support part 40. The finishing whetstone 42 is fixed to the whetstone support portion 40 at its negative side. The pressing surface of the support portion 40 located on the opposite side of the grindstone fixing surface forms a concave surface 44 with a curvature corresponding to the radius of the processing shaft 20, and the concave surface 44 has a length sufficiently shorter than the interval between the grooves 34, 34. It has a certain quality.

A finishing method for grinding the processing surface 30 of the processing shaft 20 in which the grooves 34 have been formed in advance as described above using the finishing grindstone 42 is as follows.

As shown in FIG. 5, the insertion portion 38 of the holter 36 is inserted into the four portions 48 of the grindstone head 46 formed in a shape corresponding to the insertion portion, and is tightened and fixed with bolts and pinholes 50. The pressing concave surface 44 of the grindstone 42 supported by the grindstone stand 46 in this way
is pressed against the machining surface 30 of the machining shaft 20 rotating in the direction of the arrow. That is, the grindstone 42 is pressed within the interval between the grooves 34 and 34, and a relatively large oscillation in the direction of arrow C is applied to the grindstone 42, thereby grinding the machined surface 30 with high shape accuracy. As mentioned above, the depth from the non-machined surface 32 to the groove 34 is set to be substantially equal to the grinding depth of the finishing grindstone 42. Therefore, when the second machining of the machined surface 30 is completed, the bottom of the groove 34 and the machined surface 30 become flush with each other, and the outer wall of the groove 34 forms a boundary between the machined surface 30 and the non-machined surface 32 (the seventh (see figure).

Although it has been mentioned here that the depth of the groove 34 is substantially equal to the machining depth of the machined surface 30, this means that the groove 34 does not remain between the machined surface 30 and the non-machined surface 32 and is completely erased. , moreover, it means a range in which no oscillation caused by oscillation occurs between the two. Therefore, even if the machining depth of the adder 1-30 is somewhat greater than the depth of the groove 34, both H are substantially equal as long as the difference is such that no wobbling occurs.

FIG. 8 is a curve showing the time relationship between the above-mentioned processing steps. The curved line indicates the grooving time using the plate-shaped grindstone 18, and the curve E indicates the finishing grinding time using the finishing grindstone 42, that is,
In the axis machining time cycle, the curve F shows the rotation time of the machining shaft 20, and the curve G shows the succession time of oscillations of the plate-shaped grindstone 18 and the finishing grindstone 42.

In addition, in the method according to the above-described embodiment, the shaft is ground after the grooving process is completed, but both may be performed at the same time. That is, the process of rotating the plate-shaped grindstone 18 and the second grindstone 42 simultaneously presses the surface 210 of the shaft 20 from the left and right sides (see FIG. 9) (see FIG. 9) (see FIG. 9). Finishing whetstone 42 using 34
The machined surface 30 is ground while applying oscillation.

Further, in the method according to the above-described embodiment, the machining depth of the machining surface 30 is kept constant, but it is also possible to increase the depth as the depth approaches the boundary of the machining surface 30. That is, the pressing concave surface 44 of the finishing whetstone 42 is also curved in the axial direction of the processing shaft 20 so as to be concave with respect to the peripheral surface 28 of the processing shaft 20, and is pressed against the processing surface 30 (
(See Figure 1θ). In this case, it will be easily understood that the depth of the groove 34 is substantially the same as the machining depth of the boundary portion of the machining surface 30.

In the method of the present invention, as described above, a groove with a depth substantially equal to the machining depth of the machining surface of the machining shaft is formed in advance at the end of the machining surface, and the machining surface is ground while applying oscillation to the finishing whetstone. Therefore, it is possible to perform finishing machining with high shape accuracy without reducing the effective machining width.

The present invention has been described above with reference to preferred embodiments, but the present invention is not limited to these embodiments, and can be applied to cylindrical bodies other than shafts, as well as grinding of cylindrical bodies. Of course, various improvements and design changes are possible without departing from the above.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a plate-shaped grindstone that performs grooving on a processing shaft according to the method of the present invention, and Figure 2 shows that the grindstone shown in Figure 1 is pressed against the processing shaft to perform grooving. FIG. 3 is a partially cutaway plan view of the machining state shown in FIG. Fig. 5 is a front view showing the state in which the grinding wheel shown in Fig. 4 is pressed against the processing shaft for grinding, and Fig. 6 is a finishing process of grinding by pressing the grindstone shown in Fig. 5 against the processing shaft. Fig. 7 is a plan view showing the state in which -C is performed.
FIG. 8 is a plan view showing the relationship between the grinding wheel and the shaft when grinding has almost reached the completion stage, FIG. 8 is a curve showing the time relationship of each machining process according to the method of the present invention, and FIG. FIG. 10, which is a plan view showing an embodiment, is a partially omitted sectional view showing still another embodiment of the present invention. 10... Holder 12... Insertion part 14... Grinding wheel support part 16... Grinding wheel mounting surface 18... Plate grindstone 20... Machining shaft 22... Notch 24... Grinding wheel head 26... Recessed part 28... Circumference Surface 30... Processed surface 32... Non-processed surface 34... Groove 36... Boulder 38... Insertion part 40... Grinding wheel support part 42... Finishing whetstone 44... Pressing concave surface 46... Grinding wheel head 48... Part 4 Patent Applicant Honda Motor Co., Ltd. Applicant Agent Patent Attorney Chiba -Hiroshi''-1゛)Fig,
8 Tokukai

Claims (4)

[Claims] (1) Pressing a grindstone against the rotating workpiece, and grinding the processed surface of the workpiece with the grindstone while making minute reciprocating movements in a direction substantially perpendicular to the rotational direction of the workpiece. A grinding method comprising the steps of forming an annular groove on the machined surface with a depth substantially equal to the processing depth of the grinding process, and grinding the remaining machined surface up to the processing depth of the groove. A method for grinding a circular object, which is characterized by: (2) In the method described in claim 1, the workpiece is provided with two grooves on its circumferential surface, and the two grooves substantially have a predetermined grinding width. A method of grinding circular bodies spaced apart with the same width. (3) In the method according to claim 1, the workpiece has a cylindrical shape, and a plate-shaped grindstone is pressed against the circumferential surface of the workpiece that rotates around the axis of the cylinder. , a method for grinding a circular body, which comprises grinding the belt-shaped circumferential surface of the cylinder to form grooves. (4) The method according to claim 3, in which the end face of the plate-shaped grindstone has a notch having a radius of curvature corresponding to the radius of the cylinder forming the workpiece.