JPS6362321B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a punching cutter having a center pin for positioning, and its purpose is to ensure that the tip of the center pin bites into a workpiece at a predetermined position at the start of drilling. Next, another object of the present invention is to provide a punching cutter which can be used as a guide to smoothly cut with a cutter tube.

An embodiment of the present invention in a carbide hole cutter for deep holes will be described below with reference to FIGS. 1 to 3.

Reference numeral 11 is a cylindrical cutter tube with a lid, and a large number of cutting tips 12 are attached to the tip edge thereof at equal intervals. G is a large number of discharge grooves formed on the outer peripheral surface of the cutter cylinder 11 on the leading side of each cutting tip 12 in the rotational direction, and each groove has a certain width.
Each discharge groove G extends obliquely toward the axis of the cutter barrel 11 and toward the rear in the rotational direction of the cutter barrel 11 . This discharge groove G is for discharging chips toward the proximal end of the cutter cylinder 11, that is, to the outside of the hole during drilling.

11a is a screw hole formed at the base end of the blade barrel 11, and T1 is a tapered portion formed at the inner periphery of the outer end of the screw hole 11a.

Reference numeral 13 denotes a shank having a bolt portion 13a at its tip screwed into a screw hole 11a at the base end of the cutter tube 11, and the bolt portion 13a has a screw hole 11a at the base end thereof.
A tapered portion T2 is formed to be fitted into the tapered portion T1 of the first portion. Reference numeral 13b is a fitting shaft portion formed at the base end of the shank 13, and is adapted to be fitted and fixed into a spindle of an electric drill or the like. Inside the shank 13, as shown in FIG. 1, a guide hole 14 extends from the tip to the base end along the axis.
A coil spring 15 is provided within the guide hole 14 .

16 is a center pin inserted into the guide hole 14 against the coil spring 15,
A drill blade 17 is formed on the tip stepped surface 16a. Reference numeral 18 denotes a guide groove formed in the longitudinal direction of the outer circumferential surface of the center pin 16, which is screwed into a screw hole 19 transparently provided below the tip of the large diameter portion 13c of the shank 13 and fixed with a nut 20. It is engaged with the screw 21. Therefore, center pin 1
6 is non-rotatable with respect to the shank 13 and is slidable in the longitudinal direction.

22 is the center pin 1 as shown in Figures 1 and 3.
6 is a fitting recess formed with a notch on the upper side of the base end, and its left side surface is a tapered surface T3 that slopes leftward. 23 is an insertion hole formed through the large diameter portion 13c of the shank 13 corresponding to the fitting recess 22;
is a lock pin inserted into the insertion hole 23 from above, and its inner end is inserted into the registration fitting recess 22 so as to be retractable. In the fitted state, the center pin 16 is locked so that it cannot move back in the proximal direction. T
4, T5 are a pair of tapered parts formed at both the inner and outer ends of the lock pin 24, and the inner end taper part T4
is capable of engaging with the tapered surface T3 of the fitting recess 22.

Therefore, when the center pin 16 is pushed to the right, the lock pin 24 is pushed outward by the tapered surface T3 of the fitting recess 22.

25 is a cylindrical movable tube fitted onto the large diameter portion 13c of the shank 13 in correspondence with the lock pin 24, and is rotatable relative to the shank 13 and movable in the axial direction of the shank 13. It's summery. Reference numeral 26 denotes a relief groove recessed in the inner circumferential surface of the tip end of the movable cylinder 25, and when the movable cylinder 25 is moved to the left as shown in FIG.
The pin 24 is allowed to move upward in correspondence with the outer end of the pin 24. T6 is a tapered surface inclined to the left formed on the left side of the relief groove 26,
It can engage with the tapered portion T5 at the outer end of the lock pin 24.

Therefore, when the movable cylinder 25 is pushed to the right in the engaged state of these T6 and T5, the lock pin 24 is urged inward.

37 is a pair of left and right positioning grooves formed on the inner periphery of the movable cylinder 25 on the right side of the escape groove 26;
is a storage hole bored in the large diameter portion 13c of the shank 13 so as to selectively correspond to one of the two grooves 37, and a locking ball 40 is inserted into the positioning groove 37 through a coil spring 39. It is inserted so that it can be moved in and out.

27 is a cylindrical bearing member that rotatably supports the small diameter portion 13d of the shank 13;
can be moved in the axial direction. Reference numeral 28 denotes a connecting cylinder portion protruding from the left end of the coaxial bearing member 27, and houses the right end portion of the movable cylinder 25 therein. 2
Reference numeral 9 denotes a plurality of screws screwed into the connecting cylinder part 28 from the outside, and the inner end of each screw is connected to the movable cylinder 25.
The groove 25a is inserted into the groove 25a formed on the outer peripheral surface of the groove 25a.

Therefore, the movable cylinder 25 and the bearing member 27 are moved as a pair in the axial direction of the shank 13. Note that leftward movement of the bearing member 27 is restricted by a stepped portion 13e between the large diameter portion 13c and the small diameter portion 13d of the shank 13.

Reference numeral 30 denotes a stop ring that is engaged with the outer periphery of the right end of the small diameter portion 13d of the shank 13 so as to restrict rightward movement of the bearing member 27.

Reference numeral 31 denotes a screw hole formed in a part of the bearing member 27, and is used to attach a rotation stopper that is grasped by the operator during work. 32 is bearing member 2
A pair of hole rings 33 are holes provided through the small diameter portion 13d of the shank 13, and the holes 33 are holes through which oil injected through an oil injection hole (not shown) formed in the bearing member 27 is passed through the guide. It is adapted to be guided into the hole 14.

Next, to explain the operation of the carbide hole cutter for deep holes configured as described above, first, in the state shown in FIG. Shyank 1
3 and the cutter cylinder 11 are rotated together, and a drill bit 17 formed at the tip of the center pin 16 is used to drill a hole in a predetermined position of the workpiece. And the drill blade 17
When the surface of the workpiece is slightly drilled and the step surface 16a of the center pin 16 comes into contact with the processing surface, the contact between the step surface 16a and the processing surface prevents further drilling and cutting by the drill blade 17. It is stopped and the center pin 16 spins idly. Therefore, at this point, the positioning of the deep hole carbide hole cutter with respect to the workpiece is completed.

When positioning the hole cutter using the center pin 16 in this way, the center pin 1
Since the drill bit 17 at the tip of the drill bit 6 bites into the workpiece, it will not deviate from a predetermined position with respect to the workpiece. Also, in this case, the inner end of the lock pin 24 of the center pin 16 is engaged in the fitting recess 22 so that it cannot be pulled toward the proximal direction, so it is not possible to press the center pin 16 against the workpiece with a strong force. This makes it possible to more reliably prevent deviation from the predetermined position.

Next, in order to perform drilling and cutting of the workpiece with the cutting tip 12, the bearing member 27 is moved toward the tip of the center pin 16 as shown in FIG. 2 while pressing the electric drill toward the workpiece. Then,
The tapered surface T4 of the inner end of the lock pin 24 is pushed and urged outward by the tapered surface T3 of the engagement recess 22 engaged with it, and at the same time, the movable cylinder 25 moves in the same direction together with the bearing member 27. The relief groove 26 on the inner circumference corresponds to the outer end of the lock pin 24.

In this case, the locking ball 40 that has been engaged in the left positioning groove 37 of the movable barrel 25 is temporarily retracted into the storage hole 38 against the elasticity of the coil spring 39 due to the left movement of the movable barrel 25, and then It is exposed again and inserted into the right positioning groove 37.

Note that the movement of the bearing member 27 and the movable cylinder 25 is such that the left end of the bearing member 27 is the large diameter portion 13c of the shank 13.
It is regulated by hitting the stepped portion 13e between the small diameter portion 13d and the small diameter portion 13d.

When the lock pin 24 corresponds to the relief groove 26 as described above, the lock pin 24 is inserted into the relief groove 26 as shown in FIG.
The center pin 16 comes out of the fitting recess 22 and retreats into the relief groove 26, and the center pin 16 is released from the locked state. Therefore, the center pin 16 is deeply inserted into the guide hole 14 against the coil spring 15, and as a result, the tip of the cutter cylinder 11 comes into contact with the workpiece, and drilling and cutting by the regulating tip 12 is started.

When cutting is started using the tool barrel 11, the drill blade 17 of the center pin 16 remains in the workpiece, so the cutting tip 12 is guided by the center pin 16 and smoothly moves without shifting from the predetermined position. The workpiece will be cut. Therefore, the blade barrel 11 is tilted and the cutting tip 12
will not be damaged.

After the start of cutting, the center pin 16 does not participate in the drilling until the cutting tip 12 completes the drilling and is simply guided backwards while rotating idly, which reduces the load during drilling and reduces the load on the electric drill. can be made smaller and power consumption can be reduced.

Also, when drilling in this way, the blade barrel 11
Since a large number of discharge grooves G are formed on the outer periphery of the hole that extend diagonally backward in the direction of rotation, chips of concrete, metal, etc. are easily discharged to the outside of the hole through these discharge grooves G. . Therefore, the load on the cutter barrel 11 is reduced, and its rotation becomes smooth.

Furthermore, during the above-mentioned drilling, the load is applied to the cutter tube 11 and its tip tends to swing, but since the axis of the cutter tube 11 is held so as to coincide with the axis of the shank 13, The tip of No. 11 does not swing much. That is, when the cutter barrel 11 is attached to the shank 13, the tapered portion T2 at the tip of the shank 13 is fitted into the tapered portion T1 at the base end of the cutter barrel 11, so that the axis of the cutter barrel 11 is always aligned with the shank 13. The blade barrel 11 is held so as to coincide with the axis of the shank 13, so that the blade barrel 11 is less likely to move relative to the shank 13.

If the runout of the knife barrel 11 is reduced in this way,
The threaded portion between the knife barrel 11 and the shank 13 will not be twisted, and the threads in this portion will not be damaged.

When the drilling operation is completed as described above, the center pin 16 is naturally pushed toward the tip by the elasticity of the coil spring 15, and returns to the state shown in FIG. 1. At this time, the movement of the center pin 16 is stopped by the regulation screw 21 engaging with the inner end of the guide groove 18 of the center pin 16. At this time, the fitting recess 22 of the center pin 16 also corresponds to the inner end of the lock pin 24, so that the pin 24 can protrude into the fitting recess 22.

When the center pin 16 is pushed out toward the tip,
Next, as shown in FIG. 1, the bearing member 27 and the movable cylinder 25 are slid toward the proximal end of the center pin 16 against the locking ball 40 until the bearing member 27 hits the stop ring 30. Then, at this time,
The tapered surface T6 of the relief groove 26 of the movable cylinder 25 pushes the tapered portion T5 at the outer end of the lock pin 24 inward, and the inner end of the lock pin 24 is pushed inward by the tapered surface T6 of the relief groove 26 of the movable cylinder 25.
It is engaged in the fitting recess 22 of No. 6. Therefore, the center pin 16 is again locked so that it cannot move back, and is ready for the next drilling operation.

Movable cylinder 25 and bearing member 27 in the above embodiment
may be formed integrally.

As described in detail above, the present invention provides a shank 1 equipped with a cutter barrel 11 having a plurality of cutting tips 12.
A guide hole 14 is provided at the axis of 3, and a coil spring 15 is arranged within the guide hole 14.
Center pin 1 with drill bit 17 formed at the tip
6 is movably inserted into the guide hole 14 against the coil spring 15, and the center pin 16 is connected to the shank 13 so as to be rotatable together with the regulating member 21.
3 so as to be movable in the radial direction, and when moved toward the center of the shank 13, it engages with the center pin 16 to lock it against movement in the axial direction, and is moved outward. By providing a lock pin 24 that can be unlocked when the hole is cut, the center pin can be positioned accurately at the start of drilling, and the cutting tip can be smoothly inserted into the cutting tip using the tool barrel. This invention is practically preferable as a cutter for punching because it has the effect of preventing damage to the cutter.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a punching cutter embodying the present invention, FIG. 2 is a vertical cross-sectional view with the center pin retracted, and FIG. 3 is a cross-sectional view. Cutting tool cylinder...11, Cutting tip...12, Shank...13, Guide hole...14, Coil spring...15, Center pin...16, Drill blade...
...17, Regulation screw...21, Lock pin...2
4.

Claims (1)

[Claims] 1. A knife barrel 11 having a plurality of cutting tips 12
A guide hole 14 is provided in the axis of the shank 13 to which the shank 13 is attached, and a coil spring 15 is arranged in the guide hole 14, and a center pin 16 having a drill bit 17 formed at the tip is pushed against the coil spring 15. The center pin 16 is movably inserted into the guide hole 14, and the center pin 16 is rotatably connected to the shank 13 by a regulating member 21, and is further inserted into the shank 13 so as to be movable in the radial direction. , a lock pin that engages with the center pin 16 when moved toward the center of the shank 13 and locks it against movement in the axial direction, and releases the lock when moved outward. A punching cutter characterized by having 24 holes. 2. A tapered portion T4 is formed at the inner end of the lock pin 24, and a fitting recess 22 for engaging the inner end of the lock pin 24 is formed on the center pin 16. A patent claim characterized in that a tapered surface T3 is formed so that when the center pin 16 is pulled into the guide hole 14, it engages with the tapered portion T4 of the lock pin 24 and pushes the pin 24 outward. The perforating cutter according to item 1. 3. On the shank 13, the lock pin 24 is moved to the center pin 1 by being moved in the axial direction of the shank 13.
6. The punching cutter according to claim 1, further comprising a movable cylinder 25 which is held at a fixed position in the locked state and the released state. 4. A relief groove 26 is formed on the inner periphery of the movable cylinder 25 to allow the outer end of the lock pin 24 to enter when the lock pin 24 is moved outward. A cutter for perforation according to item 3.