JPH0453610A - Tool deflection preventing jig for ultrasonic rotary drill - Google Patents

Abstract

PURPOSE:To prevent the deflection and bending of a working tool by installing three radial ball bearings, freely moveable to the center of a through-hole and also freely rotatable in contact with an outer circumferential surface of a shaft of the working tool, in and around the through-hole in the bottom of a cylindrical body. CONSTITUTION:When deep drilling operation is performed with a center rest jig, first of all, a working tool 4 is attached to a housing of a spindle 2 and then an adjusting bolt 8 is looened to some extent, a bearing holder 7 is retracted, and a cylindrical body 1, which makes a tip part of the working tool 4 projectable from the through-hole 5, is attached to the housing of the spindle 2 via a bolt 3. The adjusting bolt 8 is tightened, the bearing holder 7 is advanced forward, making a radial ball bearing 9 contact with an outer circumferential surface of a shaft of the working tool 4, and then the working tool 4 is approached to a workpiece W by feed of a spindle sleeve, thus deep drilling takes place. At the time of starting this deep drilling operation, the deflection of the tip part of the working tool 4 is prevented by three radial ball bearings 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a jig that prevents a deep hole drilling tool used in an ultrasonic rotary drilling machine from wobbling or deflecting at the start of processing.

[Prior Art] Conventionally, there is no jig that prevents this type of machining tool from wobbling or deflecting when starting deep hole machining.

Therefore, when drilling deep holes using an ultrasonic rotary drilling machine, a standard type (about 40 mm in length) machining tool can be used to guide (
After drilling a pilot hole to a depth of about 10 mm, the machine is stopped, and a deep hole machining tool is replaced with a deep hole machining tool.

[Problems to be Solved by the Invention] For this reason, conventionally, when performing deep hole machining, two types of machining tools are required: a standard type machining tool and a deep hole machining tool of a required length.

Furthermore, the ultrasonic rotary drilling machine must be temporarily stopped and tools replaced, resulting in wasted machining time.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a tool resting jig for an ultrasonic rotary drilling machine that can perform deep hole drilling using only a processing tool for deep hole drilling.

[Means for solving 11 problems] The i! In order to solve this problem, the tool steady jig for an ultrasonic rotary drilling machine of the present invention has a cylindrical shape with a bottom that is removably fitted on the outside of the main shaft, and a machining tool is inserted through the center of the bottom. A cylindrical body provided with a through hole, and a cylindrical body attached to the periphery of the through hole at the bottom of the cylindrical body so as to be able to move forward and backward with respect to the center of the through hole, and which is rotatable by contacting the outer peripheral surface of the shaft of the processing tool.
It consists of several radial ball bearings.

[Operation] In the above means, the three radial ball bearings prevent the machining tool from wobbling or deflecting.

It is desirable that the contact position of the radial ball bearing be as close to the tip of the processing tool as possible.

Further, it is preferable that the radial ball bearing be replaceable with one of a size corresponding to the thickness of the shaft of the processing tool.

Processing tools that can be used with steady rest jigs include diameters of 2 to 12 mm and lengths of 100 to 200 mm (maximum of 400 mm).
(possible up to about mm). The diameter of the processing tool is 2
If the diameter is less than 12 mm, the influence of the strength of the tool base material will be large and the steady rest effect will not be obtained, and if the diameter exceeds 12 mm, no runout will occur at the above length, making it difficult to use the steady rest jig. This is because there is no need to use it.

[Example code] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a tool steadying jig according to the present invention.

In the figure, 1 is a cylindrical body, which includes a cylindrical part 1a that is removably fitted to the outside of the lower end of the housing of the main shaft 2 of the ultrasonic rotary drilling machine via a bolt 3, and It is provided in the shape of a cylinder with a bottom, consisting of a cup part 1b screwed together, and a through hole 5 is provided in the center of the bottom, through which a machining tool 4 for deep hole machining attached to the main spindle 2 is inserted. It has the same length as the hole machining tool 4.

As detailed in FIGS. 2 and 3, a circumferential groove 6 having a rectangular cross section is provided in the circumferential wall of the through hole 5 leading to the bottom of the cylindrical body 1. , 3 bearing holders 7
are fitted so as to be movable in and out of the center of the through hole 5 via adjustment bolts 8 screwed into the bottoms thereof, and are spaced apart from each other at equal intervals in the circumferential direction. Each bearing holder 7 is provided with a U-shaped cross section with a bearing housing recess 7a (see FIG. 3) provided at the center side of the through hole 5. A radial ball bearing 9 is rotatably attached via a shaft 10 to be rotated while contacting the outer peripheral surface of the radial ball bearing 9 .

To perform deep hole drilling using the steady rest jig with the above configuration,
First, after attaching the processing tool 4 to the housing of the spindle 2,
The adjustment bolt 8 is loosened, the bearing holder 7 is moved backward, and the cylindrical body 1, which allows the tip of the processing tool 4 to protrude from the through hole 5, is attached to the housing of the main shaft 2 via the bolt 3.

Next, the adjustment bolt 8 is tightened to move the bearing holder 7 forward, so that the radial ball bearing 9 comes into contact with the outer peripheral surface of the shaft of the processing tool 4, and after that, the processing tool 4 is brought closer to the workpiece W by feeding the spindle sleeve. Perform deep hole drilling.

At the start of deep hole machining, the tip of the machining tool 4 is prevented from wobbling by the three radial ball bearings 9.

[Effects of the Invention] As described above, according to the present invention, the three radial ball bearings prevent the machining tool from wobbling or bending, so deep hole machining can be performed using only the machining tool for deep hole machining. In addition, the life of the machining tool is extended, and there is no need to use a standard type machining tool in addition to the conventional one for deep hole machining, and there is no need to waste machining time due to tool replacement.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal sectional view of a tool steadying jig for an ultrasonic rotary drilling machine according to the invention, and Fig. 2 is a longitudinal cross-sectional view taken along the line II-II in Fig. 1. cross-sectional view,
FIG. 3 is an enlarged sectional view of the main part. 1... Cylindrical body 2... Main shaft 4... Processing tool 5... Through hole 6... Circumferential groove 7... Bearing holder 8... Adjustment bolt 9... Radial ball bearing 0 ···shaft

Claims (1)

[Claims] (1) A cylindrical body that is removably fitted on the outside of the spindle and has a cylindrical shape with a bottom and a through hole in the center of the bottom for inserting a processing tool, and the area around the through hole at the bottom of the cylindrical body. A tool resting jig for an ultrasonic rotary drilling machine, which is comprised of three radial ball bearings that are attached to the holder so that they can move forward and backward with respect to the center of a through hole, and that are rotatable by contacting the outer peripheral surface of the shaft of a processing tool.