JPH0319763A - Finishing method for cylinder head bore - Google Patents

Abstract

PURPOSE:To improve the roundness of a bore, even when a quench-hardened part is formed in a direction of bore axis, by using a honing head, provided with grindstones having a part tilted for a cylinder bus in a grindstone holder so as to come into contact with at least one quench-hardened part despite a position in a circumferential direction, to perform honing work. CONSTITUTION:A grindstone 18 in a honing head 16 has a part tilted for a cylinder bus in a grindstone holder 20, that is, a part helically arranged. Thus in whatever position in a circumferential direction the grindstone 18 is placed, at least its one part is placed in a condition coming into contact with a quench- hardened part 14. That is, a condition, that the grindstone 18 is brought into contact only with a part of low hardness between the quench-hardened parts 14, is prevented from being generated. Accordingly, a protruding amount of the grindstone 18, pressed to the outer in a radial direction by a spring, for instance, is determined by the quench-hardened part 14 of high hardness, and a fixed value of a cutting amount is obtained over the total periphery of a bore 12. As a result, roundness of the bore 12 is obtained in a very high degree.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method of finishing a cylinder head bore.

(b) Conventional technology As a method of hardening the cylinder block bore of an engine,
For example, as shown in Japanese Utility Model Application Publication No. 63-24347-s3, a laser beam is irradiated into the bore. The laser beam is irradiated onto the bore, for example in the axial direction. That is, belt-shaped hardened portions are formed extending in the bore axial direction at predetermined intervals in the bore circumferential direction. After hardening, the bore is honed. Honing is a process in which a honing head with a grindstone is rotated and reciprocated in the direction of Illll1 to finish the bore. A square bar-shaped honing stone is arranged along the cylindrical generatrix of the grinding wheel holder and is pressed into the bore by the force of a spring, for example.

(c) Problems to be Solved by the Invention However, there is a problem in that the above-mentioned method of finishing cylinder head pores in Japan is only able to obtain a sufficient degree of trueness of the bore. That is, the quench hardened portions in the bore axis direction are arranged at predetermined intervals in the circumferential force direction. Therefore, in the l'J L'11 force direction, the high hardness part and the low hardness part intersect! L to f. There will be. For this reason, the parts with low hardness are cut by the grindstone, while the parts with less hardness are cut by the grindstone.
l There will be fewer shots. This causes unevenness in the cross-sectional shape of the bore, making it impossible to obtain the desired roundness.

One object of the present invention is to solve such problems.

(2) F stage for solving the problems The present invention solves the above problems by making the grindstone of the honing head oblique with respect to the cylindrical generatrix. That is, the finishing method of the cylinder head bore according to the present invention is intended for a bore in which the bore shaft cover has a plurality of quenched and hardened portions, and the finishing method for the cylinder head bore according to the present invention is intended for a bore having a plurality of gauge-shaped quench hardened parts on the bore axis cover, and has at least The honing process is performed using a honing head equipped with a honing stone having a portion inclined with respect to the U line of the inner cylinder of the whetstone I1 holder so as to come into contact with one hardened part.

(E) The working whetstone 1-i has a part inclined with respect to the cylindrical weld line, and is configured to come into contact with the hardened slender part of at least one piece of wood regardless of its position in the circumferential direction. . For this reason,
The amount of protrusion of the grindstone is determined by the hardened part. Therefore, the whetstone is easier to use in the sand melon part.
The occurrence of a 4+- effect, which is a prominent cutting tit- or an increase in cutting tit-, is controlled, and a uniform cutting star can be obtained over the bore circumference. This will improve the true P degree of the bore.

(To) Example of a real cell First, as shown in Fig. 1, insert a laser beam into the bore 12 of the cylinder block 10! 1 {} Quenching is performed by irradiating. The laser beam is moved in the axial direction of the bore 12, and the quenched and hardened part 14 in the shape of a jil, which extends to the bore axial force 1r11, is moved to a circle J. ′, ” are formed in large numbers at predetermined intervals in the directions. Next, using Honinck Head] 16 (not shown in Figure 2), stone Honinck Kao as shown in the third country. The lower stone 18 of the Honinkhet 16 has an oblique portion with respect to the cylindrical LrJ line of the grindstone halter 20, that is, a portion arranged in a W-shape. As a result, a hard 1. Even in the position in the 'd direction, at least a part of the grinding wheel A:i18 is in contact with the quenched hardened portion 14. -4- In other words, a situation in which the abrasive A-118 contacts only the A1 part of +W += between the quenched and sanded parts 14 is prevented from occurring. The amount of protrusion of the grinding wheel 18 is determined by the hardened part 14 with high hardness, and the amount of cutting is constant over the entire length of the bore 12 J,!=:I 9 As a result, the roundness of the bore 12 is It will be very expensive.

(1.) Effects of the Invention As explained above, according to the present invention, the honing process is performed using a whetstone that is inclined so that at least a portion always comes into contact with the quench-hardened part. Even if the hole is formed in the axial direction of the bore, high roundness of the bore can be obtained.

[Brief explanation of the drawing]

The first section shows the cylinder block, the second section shows the honing head, and the third section shows the honing head machining a bore. DESCRIPTION OF SYMBOLS 10...Cylinder block, 12. Pore, 14...Hardened film part, 16. Honink head, 18...Whetstone, 20...Whetstone holder

Claims (1)

[Claims] In a finishing method for a cylinder head bore in which a plurality of belt-shaped hardened parts are formed in the bore axis direction by irradiation with a high-energy beam, the finishing method is such that the cylinder head bore is in contact with at least one hardened part regardless of its position in the circumferential direction. A method for finishing a cylinder head bore, characterized in that honing is performed using a honing head equipped with a grindstone having a portion inclined with respect to a cylindrical generatrix of a grindstone holder.