JP2661414B2 - Honing head for drilling with bottom - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precision machining tool for an inner surface of a cylinder, and more particularly to a honing head for machining a hole with a bottom which is suitable for improving the accuracy of honing.

[0002]

2. Description of the Related Art Honing processing aims to improve processing accuracy such as roundness, straightness, and plane roughness in precision processing of a cylindrical inner surface processed by boring, grinding, and the like.
Reciprocating motion in the axial direction over the entire length of the inner surface of the cylinder while rotating the honing head, which supports a plurality of square rod-shaped fine-grain stones that make surface or line contact with the inner surface of the cylinder, by applying spring or hydraulic contact pressure Is to give.

A general type structure of a conventional honing head is, for example, as shown in FIG. 4, a push rod 14 pushed into the honing head body 7 by a spring, hydraulic pressure, motor drive, or the like, and fixed to the push rod 14. Or push rod 14
The grinding wheel head 5 that is in contact with the tapered surface 16 of the honing head body 7 is pushed and expanded in the radial direction through a plurality of tapered cones 15 formed integrally with the honing head body 7. As a result, the honing grindstone 6 fixed to the grindstone table 5 comes into contact with the workpiece, and the honing is performed by the rotation and reciprocation of the honing head body.

[0004]

However, in such a conventional honing head structure, since the taper cone is fixed to the push rod 14 or is formed integrally with the push rod 14, there is a problem as shown in FIG. In processing the inner surface of a bottom hole into a cylinder, the finished diameter on the stop side is 2δ smaller than the finished diameter on the opening side, and it is often difficult to secure straightness. It is known that δ is proportional to the time during which the honing grindstone is in contact, and as a countermeasure against this, in the related art, a stop time t on the stop side is provided as shown in FIG. As shown in (b), the stroke s is reduced in order to reduce the machining stop time on the opening side to 0, but the overall machining time is longer by the stop time t and both the machining surface quality and the shape accuracy are good. There was a problem that it could not be said. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a honing head suitable for improving the accuracy of processing the inner surface of a cylinder having a bottomed hole.

[0005]

Means for solving the above problems are described in the claims. That is, an object of the present invention is to provide a cylindrical honing head main body, a honing grindstone table movably supported in a radial direction along the outer circumference of the honing head main body, and the honing head main body accommodated in the honing head main body. In a honing head for processing a bottomed hole provided with supporting means for pressing and supporting a honing wheel head in a radial direction of a processing hole, the supporting means includes a honing wheel head moving toward the stop side of the processing hole, This is achieved by a honing head for drilling a bottomed hole, characterized by having a pressing means for forcibly expanding the stop side in the radial direction.

[0006]

As described above, as the honing wheel head moves to the stop side, the stop side portion of the wheel head is forcibly expanded in the radial direction, so that the processing pressure on the side close to the stop side of the honing hole is reduced. Can be increased,
The phenomenon that the finished diameter on the stop side is smaller than the finished diameter on the opening side does not occur.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of the present invention.
First, the configuration of the present embodiment will be described. The tapered cone 1a is provided integrally with the push rod 3a or fixedly provided on the push rod 3a, while the tapered cone 2b is provided integrally with the push rod 4b or fixed to the push rod 4b. It is provided. Thus, the tapered cone 1a and the tapered cone 2b are configured to be able to operate independently and independently of each other. Further, the taper cone 1a and the taper cone 2b
The honing whetstone 6 is fixed to the outer circumference of the whetstone base 5 by means of an adhesive or a screw or the like.

The grindstone table 5 is held at a predetermined position by a honing head body 7, and the taper cones 1a and 2b are independently movable in the axial direction. The honing head body 7 and the metal guide 8 are provided with air micros 13 for measuring dimensions.

Next, the operation of this embodiment will be described. The push rod 3a and the push rod 4b are individually pushed into the honing head main body 7 by an amount specified by the control device by driving a hydraulic pressure or a stepping motor. This allows the grinding wheel head 5
Is expanded in the radial direction of the hole to be machined by the tapered surface 9.

As described above, since the finished diameter becomes smaller at the stop side of the hole to be machined, as the honing grindstone 6 moves to the stop side, the pushing force of the push rod 4b is made larger than the pushing force of the push rod 3b. By forcibly expanding the stop side portion of the honing grindstone 6 in the radial direction, the honing processing capability is improved and the accuracy is also improved. The stroke cycle at this time is as shown in FIG. 8, and the stop time t of the lower end portion shown in FIG. 6B is not required, and the entire machining time is reduced.

FIGS. 2 and 3 show another embodiment of the present invention. In the embodiment shown in FIG. 2, the female screw 10 formed on the tapered cone 1a and the male screw 11 formed on the shaft surface of the push rod 4b are screwed together, and at least one of the push rod 3a and the push rod 4b is rotated. By taper cone 2b
Alternatively, it is configured such that the grindstone table 5 is pressurized while the tapered cone 1a moves inside the honing head body 7. It is preferable to use a stepping motor for driving the push rods 3a and 4b.

In the embodiment shown in FIG. 3, a pressure element 12 is incorporated between the push rod 4b or the push rod 4b and the taper cone 2b, and the taper cone 2b is slightly displaced in the axial direction in accordance with the applied voltage, so that the taper cone 1a The tapered cones 2b are configured to operate independently of each other.

The embodiment shown in FIGS. 1 and 2 has excellent resistance to uneven wear of the grindstone, so that the amount of change in the expansion pressure can be increased. The embodiment shown in FIG. It is suitable for high-accuracy honing.

FIG. 9 shows the operation of the embodiment shown in FIG. 1 at the time of the correction processing. By increasing the relative distance between the tapered cone 1a and the tapered cone 2b, the grindstone table 5 is moved closer to the workpiece side near the stop side of the cylindrical hole. FIG. 4 is a diagram schematically showing a state where the information is expanded.

FIG. 10 is an explanatory diagram showing the relationship between the height from the bottom of the blind hole, ie, the working depth d and the working pressure, according to the embodiment shown in FIG. until the corresponding position is set to a constant working pressure p _1, thereafter it indicates to hold increased by a predetermined value p _2.

FIGS. 11 to 14 show another embodiment using the piezoelectric element 12, which may be one in which the push rod 14 and the taper cone 15 of the prior art shown in FIG. 4 are integrally provided. FIG. 11 is a view in which a piezoelectric element 12 is interposed at a boundary portion obtained by dividing the grindstone table 5 in the vertical direction, FIG. 13 is a view in which the piezoelectric element 12 is interposed at a boundary section between the grindstone table 5 and the honing grindstone 6, and FIG. 14 and FIG. 14 show that a piezoelectric element 12 is interposed between the tapered surface 9 of the tapered cone b2 and the grinding wheel head 5, and in each case, the grinding wheel head 5 or the honing wheel 6 Is a structure that expands in the radial direction.

Further, as shown in FIG.
5 is not necessarily required.

The "pressing means configured so that the side end near the stop side of the honing grindstone base forcibly expands in the radial direction" according to claim 1 means, for example, the taper cone 1 shown in FIG.
a, a structure including a taper cone 2b, a push rod 3a, a push rod 4b, and a grindstone table 5. In the embodiment of FIG.
0, a structure in which a male screw 11 is added, and FIG. 3 shows a structure in which a piezoelectric element 12 is added to the embodiment in FIG.
Further, the embodiment shown in FIGS.
Reference numeral 5 denotes a pressure structure forcibly expanding through the piezoelectric element 12.

As described above, in each of the above embodiments, since the plurality of tapered cones constituting them are configured to operate independently and independently, the bottomed hole to be honed has a finish on the stop side. There is no adverse effect that the diameter becomes smaller than the finished diameter on the open side.

[0020]

According to the present invention, the machining accuracy, particularly the straightness, is improved by forcibly expanding the stop side of the honing grindstone base in the radial direction in response to the machining stroke in the honing machining of the inner surface of the cylinder having a bottomed hole. This provides an excellent effect of providing an excellent honing head and shortening the honing time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a honing head according to the present invention.

FIG. 2 is a longitudinal sectional view showing another embodiment of the honing head according to the present invention.

FIG. 3 is a longitudinal sectional view showing still another embodiment of the honing head according to the present invention.

FIG. 4 is a longitudinal sectional view of a conventional honing head.

FIG. 5 is a longitudinal sectional view of a blind hole processed by using a conventional honing head.

FIG. 6 is a diagram illustrating a process of correcting a blind hole by a conventional honing head.

FIG. 7 is a diagram illustrating a process of correcting a blind hole by a conventional honing head.

FIG. 8 is a view for explaining a process for correcting a blind hole in the embodiment shown in FIG. 1;

FIG. 9 is a schematic view showing the operation of the correction processing of the embodiment shown in FIG. 1;

FIG. 10 is an explanatory view showing the height from the bottom of the blind hole and the processing pressure according to the embodiment of FIG. 1;

FIG. 11 is a view showing another embodiment of the honing head of the present invention.

FIG. 12 is a view showing another embodiment of the honing head of the present invention.

FIG. 13 is a view showing another embodiment of the honing head of the present invention.

FIG. 14 is a view showing another embodiment of the honing head of the present invention.

FIG. 15 is a view showing another embodiment of the honing head of the present invention.

[Explanation of symbols]

 1a Taper cone 2b Taper cone 3a Push rod 4b Push rod 5 Wheel head 6 Honing wheel 7 Honing head body 8 Metal guide 9 Tapered surface 10 Female screw 11 Male screw 12 Piezoelectric element 13 Air micro 14 Push rod 15 Taper cone

Claims (1)

(57) [Claims] 1. A honing head main body having a cylindrical shape, a honing grindstone table supported movably in a radial direction along an outer circumference of the honing head main body, and the honing grindstone housed inside the honing head main body. In a honing head for processing a bottomed hole provided with a supporting means for pressing and supporting the table in a radial direction of the processing hole, the supporting means is provided at a stop side of the wheel base as the honing wheel base moves to a stop side of the processing hole. A honing head for drilling a bottomed hole, comprising a pressing means for forcibly expanding a portion in a radial direction.