JPS6113207Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an assembly tool for spot boring that is effective for use when spot boring work at the end of a hole is difficult or undesirable to perform from the hole end side.

When connecting two or more members with a connecting member such as a bolt or stud, both end surfaces of a connecting member through hole drilled through the member are cut to form a so-called counterbore surface, It is a widely known and commonly used means to uniformly abut the connecting members to stabilize the connection and improve the connection strength. When using a drill press as a counterboring machine, if there is an object that obstructs the work outside the hole to be counterbored, there will be no room to insert the drill, so you will need to rely on another type of cutting machine or if the situation If possible, we would have to use a palliative method such as inserting the conical shaft from the other end of the hole, attaching and detaching the cutting tool for each hole, and pulling back the conical shaft to perform cutting, which would be expensive to obtain and reduce work efficiency. Not only did it not look good, but the finish was often not beautiful.

The purpose of the present invention is to provide an assembled tool for spot boring, which does not require repeated installation and removal of the tool and does not require retraction (return) of the conical shaft during counterboring, and therefore has high work efficiency. That's true.

To achieve this objective, the assembly tool of the present invention is designed so that when passing the conical shaft from the other end of the hole to the end of the hole to be counterbored, the tool is housed within the conical shaft and does not obstruct passage. First, after reaching the counterbore processing position, at that position, the cutting tool approaches the surface to be counterbored from the cone shaft at an appropriate speed, and cuts into the surface to be machined enough to propel the conical shaft, resulting in a predetermined result. Complete the cutting,
Thereafter, the cutting tool is retracted into the conical shaft, and the conical shaft can then be moved back in the same way as in normal drilling work.

This will be specifically explained using an example illustrated as an embodiment. (Expressions such as top, bottom, left, and right are based on the drawings.) In the figure, 1 is a cylindrical cone shaft, and at the bottom of the conical shaft, the upper part 1a is cylindrical, the lower part 1b is downward, and the diameter gradually increases. A space shaped like the shape is formed, and a long hole 1c elongated in the axial direction is bored at an appropriate position in the hollow cylindrical portion 1a. The upper part 2a of the cutting tool holding shaft member 2 is slidably housed in the cylindrical portion 1a of the conical shaft 1, and the protruding pin 3
is attached at right angles to the axis, and its protruding pin projects into the elongated hole 1c and cannot rotate, but is movable in the axial direction only within the axial length of the elongated hole 1c.
An open box-shaped space 2b is provided at the bottom of the cutting tool holding shaft member 2.
is formed in this space 2b, and a dogleg-shaped flat cutting tool 4 is inserted into the space 2b using a hole 4a bored perpendicular to the dogleg surface at an appropriate position near the bending part as the shaft hole. , pin 1 to the tool holding shaft member 2
1 is attached to the shaft and attached like a lever. The coil spring 5 is located in the upper part of the box-shaped space 2b, and the circular notch bottom surface 2c
and the upper arm 4b of the cutting tool 4, and is interposed between the two in a pressed state, and when the spring 5 is at its most extended position, the upper arm 4b of the cutting tool 4
The blade part 4c bent at the lower tip of the space 2b
The blade portion 4c protrudes in the radial direction and can freely penetrate into the hole A to be counterbored (the state shown in FIG. The drilling is completed (as shown in Figure 2). The annular steady rest ring 6 has its inner circumferential surface rotatably abutting the outer circumferential portion 2d of the tool holding shaft member 2 via a bearing 7, and its upper surface 6a contacts the intermediate circumferential surface of the holding shaft member 2. It is in sliding contact with a retaining ring 8 which is threaded onto a screw 2e which is threaded into the conical shaft, so that even when the conical shaft rotates, its lower surface 6b is brought into contact with the end surface of the hole A' of the workpiece A without moving together. It can be brought into contact with the conical axis, and the swinging of the conical axis can be stopped. The bush 9 with a guide flange is fixed to the holding shaft member 2 by a set screw 9a, and the outer diameter of the flange is slightly smaller than the inner diameter of the hole A', so that it can be inserted into the hole A' and has a conical shape. It has the effect of holding the shaft in the correct position. Cylindrical space 1a of conical shaft 1
A coil spring 10 is inserted in a pressed state between the upper end 2f of the holding shaft member 2, and when no thrust is applied to the holding shaft member 2, as shown in FIG. The protrusion is located at the bottom of the elongated hole 1c. The recesses 1d and 1e formed in the upper part of the conical shaft 1 are for fixing the conical shaft 1 when the main shaft B of the drilling machine is inserted therein.

The assembly tool for spot boring of the present invention is used for workpiece A.
The procedure for cutting the end surface of the hole to be counterbored by inserting it from the upper hole end of the hole A' to be counterbored is shown below. Insert and tighten.

(b) Place the entire assembly tool so that it faces the top hole end of the target hole A' (the state of the tool is as shown in Figure 1), insert the flange of the bushing 9 with a guide flange into the hole A', and insert the steady rest ring 6. , abut against the hole end surface.

(C) When the main shaft B of the drilling machine is driven, the steady rest ring 6 remains stationary in contact with the end surface of the workpiece A, and the cone shaft 1, the holding shaft member 2, and the cutting tool 4 incorporated therein are moved to the required position. Rotate at speed.

(d) When the pyramid shaft 1 is lowered, the holding shaft member 2 cannot be lowered because the lower end surface 6b of the steady rest ring 6 is in contact with the hole end surface, so the coil spring 10 is pressed and the first As the state shown in the figure gradually approaches the state shown in Fig. 2, the end of the upper arm 4b of the cutting tool 4 slides on the shoulder 1b and the contact part moves above the shoulder, and the diameter of the space gradually decreases above the shoulder. The cutting tool 4 uses the pivot pin 11 as a fulcrum, and a blade portion 4c provided at the lower tip gradually protrudes from the space 2b to cut the counterbore surface.

(E) When the conical shaft 1 descends and the projecting pin 3 contacts the upper end of the elongated hole 1c, the conical shaft 1 can no longer be lowered (the state shown in FIG. 2), and at this point the counterbore process is completed.

(f) When the cone shaft 1 is raised (at this time, the cone shaft does not need to be rotated), the coil spring 10 expands, and the upper arm 4b of the cutting tool 4, which has been pushed toward the center by the shoulder portion 1b, is gradually pushed back by the pressing force of the spring 5, and the lower tip portion 4c of the cutting tool 4 moves into the box-shaped space 2b with the pivot pin 11 as the fulcrum.
Once the projecting pin 3 comes into contact with the lower end of the elongated hole 1c, the conical shaft 1 and the holding shaft member 2 return to their original states and will escape from the hole A' as they are.

The present invention is not limited to the above-mentioned embodiments. For example, instead of the ball bearing 7, a conventional sliding bearing may be used, or a thrust bearing may be used between the stop ring 8 and the steady rest ring 6. , the effect remains the same, and two elongated holes 1c and two protruding pins 3 may be used, and they may be installed opposite to the axis, and in place of the coil spring, other elastic bodies having the same effect may be used. .

Alternatively, the shape of the blade of the cutting tool may be different from that of the above embodiment, so that when the blade at the tip of the cutting tool gradually protrudes, cutting is performed sequentially from the inner diameter side of the hole end. , it can be used as a counterbore part-time job, similar to countersinking.

As is clear from the above description, the assembly tool for spot boring of the present invention can be installed on a drilling machine and used for one spot boring in the same way as a normal drill.
It is possible to counterbore by just descending and ascending once.
The work efficiency is improved and the structure is simple, so it can be manufactured at low cost.

[Brief explanation of the drawing]

The drawings are cross-sectional views of one embodiment of the present invention. Figure 1 shows an elevational view of the cutting tool housed in the box-shaped space of the shaft end member, and Figure 2 shows a counterbore surface being cut with the cutting tool. , the elevation with the work completed. 1...Conical shaft, 2...Bite holding shaft member, 3...
Projection pin, 4...Bite, 5...Coil spring, 6
...Flash stop ring, 8...Stop ring, 9...
Guide protrusion ring, 10... Coil spring, 11...
Pivot pin.

Claims (1)

[Scope of utility model registration request] A conical shaft hollowed to an appropriate length from one end and a cutting tool holding shaft member are connected via an elastic body in an axially expandable and non-rotatable manner, and are connected on the same axis, and the front half of the cutting tool holding shaft member In the open box-shaped space formed in the axial direction, a cutting tool having a dogleg-shaped flat rod part, the tip of which is bent outward and a cutting part is provided in this part, is inserted in the middle part. The rear end of this cutting tool is pivotally attached to the holding shaft member, and the rear end of this bit is always in contact with a sloped surface formed at the inner end of the conical shaft that contracts inward from the end surface by a spring, thereby moving the conical shaft in the axial direction. and the blade of the cutting tool so that it can protrude in the radial direction,
A bearing is interposed on the outside of the front half of the cutting tool holding shaft member at a proper position, and the tip of the cutting tool holding shaft member is brought into contact with the front end of the hole having the end face to be counterbored in the workpiece, and the conical shaft is advanced. An assembled tool for counterboring, characterized in that a steady rest ring is attached for protruding the blade portion of the tool to cut a workpiece surface.