JPH0752028A - Honing process method for inside cylinder inner face of work and honing head structure for honing process method - Google Patents

Abstract

PURPOSE:To provide a honing process method for such inner face of the inside cylinder of a work that surface pressures applied on respective faces of the inside cylinder inner face of the work are made almost uniform so as to make the inside cylinder inner faces after processing almost uniform and to provide structure of a honing head used for such honing process. CONSTITUTION:When the inner face of the inside cylinder B of a work CB/s subjected to a honing process by means of a grinding wheel 25 provided on the outer circumferencial part of the honing tool 5 of a honing head 1 rotating and reciprocating freely, honing process is performed while swinging the griding wheel 25 of which extension pressure is regulated by an extension pressure regulator 11 provided in the honing tool 5, around an axis crossing at right angles to the reciprocating direction of the honing head 1. Further, a grinding wheel shoe 23 provided with the grinding wheel 25 is installed swingably in relation to the honing tool 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a honing method for an inner surface of an inner cylinder of a workpiece and a method for machining the inner surface of an inner cylinder of a workpiece such as an inner surface of a cylinder block bore of an internal combustion engine. The present invention relates to a honing head structure used in.

[0002]

2. Description of the Related Art Conventionally, an inner surface of a bore B of a cylinder block CB as shown in FIG. 5, which is a workpiece, is conventionally provided on the outer peripheral portion of a honing tool of a honing head which is rotatable and reciprocally movable. When performing honing with a grindstone, for example, Japanese Utility Model Laid-Open No. 63-94656,
A honing head provided with an expansion pressure adjusting device for applying an expansion pressure to a grindstone as shown in Japanese Utility Model Laid-Open No. 63-27252 is used to apply a constant expansion pressure to the grindstone to provide an inner surface of the bore B. The honing process is performed on.

[0003]

By the way, since the water jacket WJ is provided in the above-mentioned conventional cylinder block CB shown in FIG. 5, a grindstone to which a constant expansion pressure is applied is placed above and below the bore B. When the end is reciprocally moved and honing is performed, as shown in FIG. 6, the rigidity distribution between the upper and lower sides of the bore B becomes higher toward the lower end of the bore B. Moreover, since the surface pressure and the rigidity have a proportional relationship, as shown in FIG.
The surface pressure increases as the position of goes to the lower end.

Therefore, the shape of the bore B at each position after the honing process becomes a curve as shown in FIG. 8, which causes variations in cutting amount and deterioration of cylindricity.

In order to solve the above problems, an object of the present invention is to make the surface pressure applied to each surface of the inner cylinder of the workpiece substantially uniform and to make the inner cylinder inner surface after machining substantially uniform. The object of the present invention is to provide a honing processing method for the inner surface of the inner cylinder of the workpiece and a structure of a honing head used in the processing method.

[0006]

In order to achieve the above object, the present invention is a grindstone provided on an outer peripheral portion of a honing tool of a honing head which is rotatable and reciprocally movable. When performing honing, the honing is performed while rocking the grindstone whose expansion pressure is adjusted by an expansion pressure adjusting device provided in the honing tool around an axis orthogonal to the reciprocating direction of the honing head. It is a honing method for the inner surface of the inner cylinder of a workpiece, which is characterized by processing.

Further, according to the present invention, a honing tool is provided at the tip of a honing head which is rotatable and reciprocally movable, and an expansion pressure adjusting device is provided in the honing tool.
A honing head structure is provided in which a grindstone shoe having a grindstone whose expansion pressure is adjusted by this expansion pressure adjusting device is swingably provided around an axis orthogonal to the reciprocating direction of the honing head on the outer peripheral portion of the honing tool. Configured.

[0008]

By adopting the honing method for the inner surface of the inner cylinder of the workpiece according to the present invention and the honing head structure used in the method, the honing head can be rotated and reciprocated so that a honing tool for the honing head can be used. Honing is performed on the inner surface of the inner cylinder of the workpiece with a grindstone provided on the outer peripheral portion.

When performing honing, a constant expansion pressure is applied to the grindstone by an expansion pressure adjusting device provided in the honing tool, and a grindstone shoe equipped with the grindstone is swingable with respect to the honing tool. Because
The honing process is performed by swinging the grindstone shoe so that a uniform surface pressure is obtained at each position on the inner surface of the inner cylinder of the workpiece. As a result, the shape at each position of the inner surface of the inner cylinder after processing is processed uniformly.

[0010]

Embodiments of the present invention will be described in detail below with reference to the drawings.

Referring to FIGS. 1 and 2, a honing head 1 which is rotatable and reciprocally movable by a driving mechanism which is already known includes a honing head body 3 having a cylindrical shape. A honing tool 5 is provided at the tip (lower end in FIG. 1).
The honing head body 3 and the honing tool 5
A hole 7 is formed in the axial center of the honing tool 5 so as to pass through in the vertical direction, and a groove 9 communicating with the lower end of the hole 7 is formed in the honing tool 5.

A rod 13 which is a part of the expansion pressure adjusting device 11 is mounted in the hole 7 so as to be movable in the vertical direction in FIG. A taper cone 15 is integrated with the lower end of the rod 13, and the taper cone 15 is housed in the groove 9.

A plurality of (six in this embodiment) holes 17 are formed in the radial direction at substantially the center of the honing tool 5 in the axial direction (vertical direction in FIG. 1).
In each of these 17 is an inclined portion 15K of the taper cone 15.
A moving block 19 having an inclined portion 19K that can be engaged with is provided, and the moving block 19 is slidable in the hole 17 in the radial direction.

Each hole 17 in the honing tool 5
A large groove 21 is formed at the tip of the hole depending on the size of the hole 17. The projecting portion 19T of the moving block 19 projects into the groove 21. A grindstone shoe 23 extending in the vertical direction in FIG. 1 is provided on the outer peripheral portion of each groove 21 in the honing tool 5. A grindstone 25 is provided on the outer peripheral portion of each grindstone shoe 23.

A grindstone shoe R portion 23R is integrally provided so as to project inward in the radial direction at a substantially central portion of the grindstone shoe 23 in the longitudinal direction (vertical direction in FIG. 1), that is, a portion facing the groove 21. ing. The protrusions 19T of the moving block 19 are fitted into the grooves formed in each of the whetstone shoe R portions 23R, and the whetstone shoe R portions 23 are fitted by the pins 27.
R is pivotably supported on the moving block 19.

Shoe-holding spring rings 29 are provided on the outer peripheral portions of the upper and lower ends of the respective grindstone shoes 23. The grindstone shoe 23 is constantly urged and held inward in the radial direction by the urging force of the shoe holding spring ring 29.

With the above structure, when the rod 13 is moved downward in FIG. 1, each moving block 19 having the inclined portion 19K engaged with the inclined portion 15K of the taper cone 15 is pressed outward in the radial direction. , Whetstone shoe 23
The expansion pressure is applied to the grindstone 25 via the. The degree of this expansion pressure is determined by the movement amount of the rod 13. If surface pressure is applied to the lower end of the grindstone 23 inward in the radial direction, the grindstone shoe 23 is swung counterclockwise in FIG. 1 with the pin 27 as a fulcrum. If surface pressure is applied to the upper portion of the grindstone 23 inward in the radial direction, the grindstone shoe 2
3 is swung clockwise in FIG. 1 with the pin 27 as a fulcrum.

Now, for example, the bore B of the cylinder block CB provided with the water jacket WJ as shown in FIG.
Using the honing head 1 shown in FIGS. 1 and 2, a constant expansion pressure is applied to the inner surface of the grindstone 25 by the expansion pressure adjusting device 11.
Suppose that it has been subjected to honing processing.

Normally, as shown in FIGS. 6 and 7, the rigidity and the surface pressure increase as the hole B moves toward the lower end of the bore B. However, in the honing head 1 of this embodiment, the grindstone shoe 23 rocks with respect to the honing tool 5. Since it is movably provided, the grindstone shoe 23 is gradually swung counterclockwise in FIG. 1 with the pin 27 as a fulcrum as the surface pressure becomes higher. A substantially uniform surface pressure is applied at each position of B.

As a result, if a uniform surface pressure is applied to each position of each bore B and honing is performed, the surface pressure variation of the grindstone 25 can be reduced. Moreover, since there is no variation in the cutting amount as shown in FIG. 8 and the shape of the bore B after machining becomes substantially equal at each position of the bore B as shown in FIG. The cylindricity can be improved.

The present invention is not limited to the above-described embodiments, but can be implemented in other modes by making appropriate changes. In this embodiment, an example in which the bore inner surface of the cylinder block is honed as the inner cylinder inner surface of the workpiece has been described, but other honing of the inner cylinder inner surface is also applicable.

[0022]

As can be understood from the above description of the embodiments, according to the present invention, since the structure is as described in the claims, each of the inner surface of the inner cylinder of the workpiece is processed. Since the surface pressure applied to the surface can be made substantially uniform and the honing can be performed, it is possible to reduce the variation in the surface pressure of the grindstone. Thus, the variation in the cutting amount can be eliminated and the inner surface of the inner cylinder after processing can be made substantially uniform, and the cylindricity of the inner surface of the inner cylinder can be improved.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of a honing head structure used when honing the inner surface of the inner cylinder of a workpiece according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a diagram showing the relationship between the bore position and the surface pressure when honing is performed in the present invention.

FIG. 4 is a diagram showing a relationship between a bore position at the time of honing processing and a bore shape after the processing according to the present invention.

FIG. 5 is a front sectional view showing a cylinder block as an example of a workpiece.

FIG. 6 is a diagram showing a relationship between a bore position and rigidity when honing an inner surface of a bore of a cylinder block with a conventional honing head.

FIG. 7 is a diagram showing a relationship between a bore position and a surface pressure when honing an inner surface of a bore of a cylinder block with a conventional honing head.

FIG. 8 is a diagram showing a relationship between a bore position when honing an inner surface of a cylinder block with a conventional honing head and a bore shape after the honing.

[Explanation of symbols]

 1 Honing Head 5 Honing Tool 11 Expansion Pressure Adjustment Device 13 Rod 15 Taper Cone 19 Moving Block 23 Grinding Stone Shoe 25 Grinding Stone 27 Pin CB Cylinder Block B Bore WJ Water Jacket

Claims (2)

[Claims] 1. A grindstone provided on an outer peripheral portion of a honing tool of a honing head which is rotatable and reciprocally movable, when honing the inner surface of an inner cylinder of a workpiece.
A honing process is performed while swinging the grindstone whose expansion pressure is adjusted by an expansion pressure adjusting device provided in the honing tool around an axis orthogonal to the reciprocating direction of the honing head. A honing method for the inner surface of the inner cylinder of a workpiece. 2. A honing tool is provided at the tip of a honing head which is rotatable and reciprocally movable, an expansion pressure adjusting device is provided in the honing tool, and a grinding stone whose expansion pressure is adjusted by the expansion pressure adjusting device is provided. A honing head structure, wherein a grindstone shoe is provided on an outer peripheral portion of the honing tool so as to be swingable around an axis orthogonal to the reciprocating direction of the honing head.