JPH05104319A - Cutting tool - Google Patents

Abstract

PURPOSE:To enhance the efficiency of machining by tilting a cam groove at a small gradient so as to keep high the speed at which a cutter and a holder slidingly reciprocate relative to each other, and enlarging the stroke of sliding of the cutter by means of a fixed rack provided on the side of a tubular body and meshing with a pinion and a moving rack provided on the side of the holder. CONSTITUTION:A base 1 is connected at its end to a spindle A. A tubular body 4 is engaged with the axially supported side of the spindle A via a locking device 5 and so rotation of the tubular body 4 is stopped and the cutting edge 23' of a cutter 23 is fitted with a machined hole of disimilar form. When the base 1 is rotated together with the spindle A, a cam groove 19 and a projection 20 convert rotation of the base 1 into reciprocating motion of a slider 18 and so when a pinion 25 slides together with the slider 28 in the direction of the reciprocating motion a fixed rack causes the pinion 25 to rotate alternately in the normal and reverse directions. Therefore, a cutter holder 22 having a moving rack 27 meshing with the pinion 25 advances by rotation in the normal direction and retreats by rotation in the reverse direction, thereby multiplying the stroke of sliding; the speed of the holder 22 is high because of the small gradient of the cam groove 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool for cutting irregularly shaped holes such as polygons and ellipses.

[0002]

2. Description of the Related Art Conventionally, in order to cut the periphery of a pilot hole to cut a polygonal hole such as a square or an irregular hole such as an oval, this rotary motion is performed while rotating the base body together with the shank attached to the spindle. A tool having a cylindrical cam groove and a protrusion engaged with each other to convert the motion into a linear motion, transmit the motion to a slider provided in parallel with the base body and slidably, and hold the end at the tip of the slider. It is designed to break through.

[0003]

According to the cutting tool having the above-described structure, the sliding (reciprocating) speed of the slider with a blade is increased when the inclination angle of the cam groove obliquely intersecting with the axis of the base body is set to be gentle. Become.

However, there is a problem that the stroke of the slider is reduced.

Therefore, by making the inclination angle of the cam groove steep, the stroke of the slider can be increased.

However, when the rotational movement is converted into the linear movement by the high-speed rotation of the spindle, the movement cannot be smoothly converted. In order to ensure the smooth movement conversion, the rotation of the spindle must be slowed. I have to. That is, the sliding speed of the slider becomes extremely low.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a cutting tool capable of sliding the slider at high speed while doubling the stroke of the slider.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a base body which is connected to a spindle at its distal end side and rotates together with the base body. A tubular body provided, a locking device provided to engage with the spindle bearing side when the base body is connected to the spindle to stop the rotation of the tubular body, and slide axially outside the base body. And a blade holder slidably inserted inward from the tip of the tubular body, and an endless gentle gradient cam groove provided obliquely intersecting the axis of the base on the outer periphery of the base. A protrusion provided on the inner surface of the slider so as to be fitted into the cam groove, a pinion supported on the slider, and arranged on both sides of the pinion to be engaged with the pinion. The cutting tool consisting of the stationary rack and the moving rack provided on the holder side is provided on Jo side is obtained by employing.

[0009]

The terminal end side of the substrate is connected to the spindle. At this time, since the cylindrical body is engaged with the bearing side of the spindle via the locking device, the rotation of the cylindrical body is stopped with respect to the spindle, and the cutting edge of the cutting tool is matched with the irregularly shaped hole shape.

However, when the base body is rotated together with the spindle, the rotation of the base body is converted into the reciprocating motion of the slider by the cam groove and the protrusion. Therefore, when the pinion slides in the forward direction and the backward direction together with the slider, The fixed rack causes the pinion to alternate between forward and reverse rotation.

Therefore, the blade holder having the movable rack that meshes with the pinion moves forward by the forward rotation of the pinion,
The slide stroke doubles as the pinion reverses and retreats.

Further, the sliding speed of the blade holder becomes high because the cam groove has a gentle gradient.

[0013]

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

As shown in FIG. 1, reference numeral 1 is a base for connecting the end side to the spindle A.

In the end connection method of the base body 1, the shank portion 2 is fitted in the taper hole a of the spindle A in the illustrated case, but it may be connected by using a method such as a clamp.

On the outer side of the tip of the base body 1, there is provided a cylindrical body 4 through which a base body 1 freely rotates at a fixed position.

Further, the tubular body 4 is provided with a locking device 5 which engages with the bearing side of the spindle A and stops the rotation of the tubular body 4 when the base body 1 is connected to the spindle A.

In the illustrated case, the locking device 5 is a cylindrical body 4.
The projecting member 6 projecting from the outer peripheral portion is provided with a recessed hole 7 which is directed downward from the upper surface, and the elevating pin 8 inserted into the recessed hole 7 is provided with an upward projecting force by a spring 9 to form a tapered hole a. When the shank portion 2 is inserted into the housing 10, the tip of the elevating pin 8 fits into and engages with the groove 12 of the block 11 fixed to the tip surface of the housing 10 of the spindle A, and the elevating pin 8 is compressed while compressing the spring 9. Is pushed down.

When the shank portion 2 is connected to the spindle A as shown in the figure, the cylindrical body 13 fitted on the outer side of the elevating pin 8 is connected to the tip surface of the block 11 and the tip edge of the cylindrical body 13. The push plate 15 to which the ascending return force is applied by the spring 14 is lowered while being lowered by the collision, and the key 16 protruding from the outer periphery of the cylindrical body 13 is allowed to escape from the outer peripheral key groove 17 of the base body 1. Then, when the base body 1 is removed from the spindle A, the key 16 is automatically fitted and engaged in the key groove 17 while the cylinder 13 is raised and returned by the pressing plate 15 to rotate the cylinder body 4 with respect to the base body 1. The lifting pin 8 is always stopped at a fixed position.

Further, on the outer side of the front end portion of the base body 1, there is fitted a cylindrical slider 18 which allows the base body 1 to rotate freely.

Reference numeral 19 denotes an endless cam groove provided on the outer periphery of the base body 1 obliquely intersecting the axis of the base body 1 at a gentle gradient, and 20 denotes a protrusion fitted into and engaged with the cam groove 19. In the illustrated case, a ball having a part of the outer circumference fitted in a recessed part 21 on the inner circumference of the slider 18 is used as the protrusion 20.

Reference numeral 22 denotes a blade holder slidably inserted inward from the tip of the tubular body 4. At the tip of the blade holder 22, the end of the processing blade 23 having an irregular hole (polygon, ellipse, etc.) is bolted. It is fixed by 24 stoppers.

Reference numeral 25 is a pinion supported by the slider 18, and fixed racks 26 integral with the tubular body 4 on both sides of the pinion 25 so as to engage with the pinion 25.
And a movable rack 27 that is integral with the holder 22.

Reference numeral 28 in the drawing denotes a rotation stop pin of the key 16.

With the above construction, the shank portion 2 is fitted in the tapered hole a of the spindle A and the base 1 is connected to the spindle A. At this time, the groove 1 of the block 11
Since the tip of the elevating pin 8 is fitted into and engaged with 2, the rotation of the tubular body 4 is stopped with respect to the base body 1 and the cutting blade 2 of the blade 23
3'and the cutting line agree, spindle A
When the base body 1 is rotated at the same time, the rotational movement of the base body 1 is converted into a linear movement by the cam groove 19 and the protrusion 20, and the slider 18 slides alternately in the forward direction and the backward direction.

At this time, the fixed rack 26 causes the pinion 25 to alternate between normal rotation and reverse rotation.

The blade holder 22 having the moving rack 27 in accordance with the normal rotation of the pinion 25 is moved forward to cut the periphery of the prepared hole b of the work B by the cutting blade 23 ', and is retracted in accordance with the reverse rotation of the pinion 25. At the same time, the slide stroke is doubled.

Further, the sliding speed of the holder 22 becomes high due to the gentle gradient of the cam groove 19.

[0029]

As described above, according to the cutting tool of the present invention, the cam groove is made to have a gentle gradient to keep the reciprocating slide speed between the blade and the holder at a high speed, and the fixed rack and the holder on the cylindrical body that mesh with the pinion are provided. Since the blade slide stroke becomes large with the movable rack on the side, the machining efficiency can be significantly improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of a cutting tool according to the present invention.

FIG. 2 is a vertical sectional side view showing the main part of the same.

[Explanation of symbols]

 A Spindle a Tapered hole 1 Base 2 Shank part 3 Bearing 4 Cylindrical body 5 Locking device 6 Projection member 7 Recessed hole 8 Lifting pin 9 Spring 10 Housing 11 Block 12 Groove 18 Slider 19 Cam groove 20 Projector 22 Blade holder 23 Blade 25 Pinion 26 Fixed rack 27 Moving rack

Claims (1)

[Claims] 1. A base body which is connected to a spindle and rotates together with the base body, a cylindrical body which is provided outside the front end side of the base body so that the base body can rotate freely, and the base body is connected to the spindle. A locking device provided to engage with the spindle bearing side to stop the rotation of the tubular body, a slider fitted to the outside of the base body so as to slide in the axial direction, and an inside from the tip of the tubular body. A blade holder slidably inserted in one direction, an endless gently sloping cam groove provided on the outer periphery of the base body obliquely intersecting the axis of the base body, and on the inner surface of the slider so as to be fitted and engaged in the cam groove. A protrusion provided, a pinion supported by the slider, arranged on both sides of the pinion and engaged with the pinion, and a fixed rack provided on the tubular body side and a movement provided on the holder side. A cutting tool consisting of a rack.