JP2003236709A - Throw-away tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throw-away tip having high repetition precision, strong tip restraint force, and high performance by shortening exchange time of the tip. <P>SOLUTION: This throw-away tip is constituted in such a way that a small diameter barlike part 3 protrudes integrally from a peripheral face of a basic part 2 like a flat plate, a cutting edge part 8 is provided at a tip of the small diameter barlike part 3, and a through hole 4 for fixing a bolt is provided in a central part of the basic part 2 like the flat plate. An inclined face 6 crossing the direction of long axis is formed on a rear side in the direction of long axis of the small diameter barlike part 3 in the basic part 2 like the flat plate, and the inclined face 6 is formed on more rear side than the through hole 4 for fixing the bolt in the direction of long axis. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-diameter rod-shaped portion integrally projected from the peripheral surface of a flat-plate-shaped base portion, a cutting blade portion provided at the tip of the small-diameter rod-shaped portion, and a bolt at the central portion of the flat-plate-shaped base portion. The present invention relates to a throw-away tip provided with a fixing through hole, and particularly to a throw-away tip suitable for a very small inner diameter machining for small products such as OA equipment parts, electronic parts and small diameter bearings.

[0002]

2. Description of the Related Art Conventionally, a small-diameter rod portion is integrally projected from a peripheral surface of a flat-plate base portion, a cutting edge portion is provided at a tip of the small-diameter rod portion, and a bolt fixing through hole is provided at a central portion of the flat-plate base portion. As shown in FIG. 4, the throwaway tip S provided with the flat base 41 is a long plate in the major axis direction (left and right direction in the figure) of the small diameter rod 47, and the flat base 41 In some cases, the rear end face 43 in (1) is an inclined surface on the rear side (the right-hand side in the figure) in the major axis direction of the small-diameter rod-shaped portion 47 and intersects with the major axis direction. In order to attach the throw-away tip S to the holder H, as shown in FIG. 5, the set bolt 51 is applied from one side surface of the holder H to the restraining side surface 44a of the peripheral surface of the flat plate-shaped base portion 41, and in FIG. , The throw-away tip S is securely pressed against the holder H at four restraint parts indicated by hatching, and then the throw-away tip S is fixed to the holder H through the bolt fixing through hole 45. At the same time, we tried to improve the restraint force to prevent the tip rotation and the accuracy of the cutting edge position when exchanging the tip.

In order to obtain a good restraint state by the set bolt 51, in the throw-away tip S,
As a result of increasing the inclination angle of the rear end face 43, the rear end face 43
And the ridge 6 intersecting with this and the non-restraining side surface 44b intersecting at an obtuse angle
1 was located at a position overlapping the bolt fixing through hole 45 in the long axis direction of the small diameter rod portion 47.

[0004]

By the way, since the conventional throw-away tip uses both the bolt inserted into the bolt fixing through hole and the set bolt, it is troublesome to attach and detach the throw-away tip. Therefore, there were many users who used without using the set bolt.

However, when the above-mentioned conventional throw-away tip is fixed without using the set bolt, the fixing force of the throw-away tip is small, the cutting edge position accuracy is likely to be incorrect, and the throw-away tip swings around the bolt. However, there is a problem that chattering is likely to occur.

Hereinafter, this problem will be described in detail.

As shown in FIG. 6 (a), when a cutting load is applied to the cutting edge portion, a moment M'at which the throw-away tip S tries to rotate around the bolt fixing through hole 45.
On the other hand, a moment in the direction of suppressing the tip rotation is generated by the reaction force received by the throw-away tip S from the restraining surface of the holder H. The magnitude of the moment is the product of the reaction force and the distance from the bolt fixing through hole 45 to the intersecting ridge portion.

Here, the restraining side surface 44a of the flat base 41
Crossing ridge portion 62 between the front end surface 42 and the front end surface 42, and the restraining side surface 4
At two points on the side of the constraining side surface 44a at the intersection ridge 63 between the 4a and the rear end surface 43, generated by the reaction force that the tip receives from the constraining surface of the holder H with respect to the moment M'when the throw-away tip S tries to rotate. However, the moments m62 'and m63' in the direction of inhibiting the tip rotation are large.

On the other hand, the intersecting ridge portion 61 between the rear end face 43 and the non-restraining side face 44b intersecting with it at an obtuse angle has a small interval with the bolt fixing through hole 45 as described above, so that the intersecting ridge face is formed. Moment m61 ′ generated from the part 61
Is small, and as a result, the contribution to suppressing chip rotation is small.

As a result, when the set bolt 51 is not used, the reference surface when the throw-away tip S is restrained by the holder H is the restraining side surface 44 of the throw-away tip S.
No matter which side of the rear end face 43 is set, the force for pressing the intersecting ridge portion 48 against the holder reference face is weak. For this reason, there is a problem in that the blade is not firmly fixed to the holder H, the edge position accuracy is likely to be incorrect, and the throw-away tip S swings around the bolt 52 to easily cause chattering.

Further, the conventional throw-away chip S has a factor that exacerbates this problem.

As shown in FIG. 6B, when the conventional throw-away tip S is combined with the holder H, the intersecting ridge line portion 62 between the restraining side surface 44a and the front end surface 42 is
An intersection point 65 of a perpendicular line descending from the center of the bolt fixing through hole 45 toward the constraining side surface 44a and the constraining side surface 44a.
On the rear side of the rear end face 43 and the restraining side face 44b.
The intersection ridge portion 61 is located on the front side of the intersection 64 of the normal line drawn from the center of the bolt fixing through hole 45 toward the rear end face 43 and the rear end face 43.

When mounting the throw-away tip S,
When tightening the bolt 52, first, the cross ridges 61, 62
Is restrained by the holder. At the same time, the component force a of the restraint force by the bolt 52 is in the normal direction of the side face 44a, and the component force b is the rear end face 4
It occurs in the normal direction of 3. From these component forces a and b, moments ma and mb are generated that try to rotate the chip with the cross edges 61 and 62 already constrained as fulcrums.

Since the intersecting ridges 61 and 62 are located on the front end face side from the intersection with the normal line drawn from the center of rotation,
The moment ma is generated counterclockwise as viewed from the top surface of the chip, and the moment mb is generated clockwise and cancels each other.

Thus, the reference surface when the throw-away tip is restrained by the holder is the throw-away tip S.
Regardless of which side of the restraint side face 44a or the rear end face 43 of the holder is set, the restraint end portion 4 near the intersecting ridge 63 on the holder reference plane.
There was a problem that the force to press 8 was weak.

In view of the problems of the prior art as described above, it is an object of the present invention to provide a high performance throw-away tip which shortens the tip replacement time and has high repeatability and tip restraining force.

[0017]

In order to solve the above-mentioned problems, a throw-away tip of the present invention has a small-diameter rod-like portion integrally protruding from the peripheral surface of a flat plate-like base, and a cutting edge portion at the tip of this small-diameter rod-like portion. A throw-away tip having a through hole for fixing bolts provided in the central portion of the flat plate-shaped base,
In the flat plate-shaped base portion, an inclined surface that intersects with the long axis direction is formed on the rear side in the long axis direction of the small diameter rod-shaped portion, and the inclined surface is rearward of the bolt fixing through hole in the long axis direction. It is characterized in that it is formed on the side.

According to this structure, when a force for rotating the chip about the bolt fixing through hole is exerted, at least three intersecting ridges in the plate-like base located at a position apart from the bolt fixing through hole. Are restrained, and the tip rotation is sufficiently suppressed at each cross edge.

Therefore, since a moment effective for suppressing the tip rotation is generated from at least three points of the flat plate-shaped base portion, a sufficient effect for suppressing the tip rotation can be exhibited.

Further, in the throw-away tip of claim 2, when a perpendicular line is drawn from the center of the bolt fixing through hole toward the inclined surface in a plan view, the perpendicular line is an extension line of the inclined surface. It is characterized by crossing with.

According to this structure, it is possible to more reliably obtain the action of generating a moment effective for suppressing the tip rotation from at least three points in the flat plate-shaped base portion.

That is, when the bolt is tightened at the time of chip replacement, first, of the peripheral surface of the flat plate-shaped base portion, the intersection ridge portion between the front end surface and the restraining side surface and the intersection ridge portion between the rear end surface and the other peripheral surface are first. The cross ridge near the bolt is restrained. Then, at this time, a component of the restraint force by the bolt is generated in the normal direction of the restraint side surface and the rear end surface. From this component force, moments are generated that try to rotate the chip with the intersecting ridges already constrained as fulcrums.

At this time, in the throw-away tip of claim 2, the moment generated from the component force of bolt tightening from the bolt fixing through hole to the inclined surface acts in the direction of pressing the throw-away tip against the restraining side surface, and A moment generated from the component force of bolt tightening from the bolt fixing through hole to the restraint side surface acts in the direction of pressing the throw-away tip against the restraint side surface.

Therefore, there is a tendency that the rotational force for pressing the throw-away tip toward the restraining side surface becomes large.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 (a) shows a throw-away tip (hereinafter referred to as a tip) 1 of the present invention, and FIG. 1 (b) is a view taken in the direction of arrow X in FIG. 1 (a).

As shown in FIG. 1, in the chip 1, the small diameter rod-shaped portion 3 is integrally projected from the peripheral surface of the flat plate-shaped base portion 2,
A cutting blade portion 8 is provided at the tip of the small-diameter rod portion 3, and a bolt fixing through hole 4 is provided at the central portion of the flat plate-shaped base portion 2. The small-diameter rod-shaped portion 3 has a lateral flank 3a, and the cutting edge portion 8 thereof has a rake face 9.

Further, in the flat plate-shaped base portion 2, an inclined surface 6 intersecting with the long-axis direction is formed on the rear side of the small-diameter rod-shaped portion 3 in the long-axis direction, and the inclined surface 6 is formed in the long-axis direction. It is formed on the rear side of the bolt fixing through hole 4.

The flat plate-shaped base 2 has a front end face 5 on the front side in the major axis direction of the small-diameter rod-shaped part 3, a rear end face 6 on the rear side, a constraining side face 7a intersecting the front end face and the rear end face, and a non-constraining side face. Have 7b.

The flat plate-shaped base 2 has an elongated shape elongated in the long axis direction. In this embodiment, the restraining side surface 7a is about 2.5 times the length of the inclined surface 6. Then, the rear end face is in contact with the restraining side face 7a at 55 ° to 80 °.
It intersects at an acute angle at an angle of ° and intersects the other side surface 7b at an obtuse angle.

Next, FIG. 2 (a) is a top view of an inner diameter processing tool 21 in which the chip 1 is mounted on a holder, and FIG. 2 (b) is a Z arrow view of FIG. 2 (a). Tool 21
FIG.

As shown in FIG. 2, the elongated holder 22.
At the tip of the upper surface 23 of the above, there is provided a notched chip pocket 24 for fitting with the flat plate-shaped base portion 2 of the chip 1.

The tip seat surface 25 of the tip pocket 24
The bottom surface provided on the flat plate-shaped base portion 2 of the chip 1 is placed on the base plate 2. Under this state, the bolt 26 is inserted from above the flat plate-shaped base portion 2 into the bolt fixing through hole 4 of the flat plate-shaped base portion 2, and the holder 22 Bolt fixing hole 27 formed in the tip seat surface 25 of
Screw on.

By fixing the chip 1 to the holder 22 in this manner, the small-diameter rod portion 3 of the chip 1 is projected in the longitudinal direction of the holder 22. Then, the small-diameter rod-shaped portion 3 can be inserted into the hole of the work, and the inside of the extremely small-diameter hole can be processed like an earpick.

An important point in the construction of the chip 1 is
In the flat plate-shaped base portion 2, an inclined surface 6 intersecting with the long-axis direction is formed on the rear side of the small-diameter rod-shaped portion 3 in the long-axis direction, and the inclined surface 6 penetrates the bolt fixing through in the long-axis direction. This is a point formed on the rear side of the hole 4.

This point will be described in detail with reference to FIG.

As shown in FIG. 3 (a), the flat plate-shaped base portion 2 forming the chip 1 intersects the ridge line portion 32 between the constraining side surface 7a and the front end surface 5, and the intersecting ridge portion 6 between the constraining side surface 7a and the inclined surface 6. The ridge line portion 33 and the intersecting ridge line portion 31 of the inclined surface 6 and the unconstrained side surface 7b are restrained by the holder 22.
Of these, the intersection ridge line portion 31 between the inclined surface 6 and the non-restraining side surface 7b is located rearward of the bolt fixing through hole 4 in the major axis direction, and extends from the center of the fixing through hole 4. The intervals are large.

That is, the holder 22 restrains the ridges at the three intersecting ridges away from the bolt fixing through hole 4.

Then, when a load is applied to the tip cutting edge ridge 8 and a moment M for rotating the tip 1 around the bolt fixing through hole 4 acts, the tip rotation is suppressed at each intersecting ridge portion. A reaction force is generated, and the moments m31 and m32 that suppress the chip rotation caused by the reaction force work more as the distance from the through hole 4 increases, so that the chip rotation can be sufficiently suppressed. Even with a flat plate shape, three points can sufficiently exert the effect of suppressing the chip rotation.

Another important configuration of the chip 1 is that when the chip 1 is viewed from above, the perpendicular line is drawn from the center of the bolt fixing through hole 4 toward the inclined surface 6. Has a point intersecting with the extension line of the inclined surface 6.

This point will be described with reference to FIG.

When the bolt 26 is tightened when the chip 1 is mounted, the cross ridges 31 and 32 are first restrained in the chip pocket 24 at the tip of the holder 22. At the same time, the restraint force by the bolt 25 generates a component force A in the normal direction of the restraint portion side surface 7a and a component force B in the inclined surface 6 in the normal direction.

The direction of the moment M _B by which the component force B rotates the tip 1 with the cross edge portion 31 already constrained as a fulcrum, the cross edge portion 31 is lowered from the center of the bolt fixing through hole 4 to the inclined surface 6. Since it is located on the rear side of the intersection point 34 with the normal, it occurs counterclockwise as viewed from the top surface of the chip. The direction of the moment M _A at which the component force A rotates the tip 1 with the crossing ridge portion 32 as a fulcrum is the intersection point 3 with the normal line of the crossing ridge portion 32 from the center of the bolt fixing through hole 4 to the restraining portion side surface 7a.
Since it is located closer to the front end face side than 5, it is generated counterclockwise when viewed from the top surface of the chip. By obtaining the rotational moment in the counterclockwise direction from the two intersecting ridge portions that are constrained first, the intersecting ridge portion 33 is strongly pressed against the constraining wall surface of the chip pocket, and good blade edge position repeatability can be obtained. .

Although the embodiments of the present invention have been illustrated above with reference to the drawings, the present invention is not limited to the above embodiments, and it is needless to say that the present invention can have any shape without departing from the object of the invention. Yes.

[0045]

As described above, in the throw-away tip of the present invention, the small diameter rod-shaped portion is integrally projected from the peripheral surface of the flat base portion, and the cutting edge portion is provided at the tip of the small diameter rod-shaped portion. A throw-away tip in which a bolt fixing through hole is provided in a central portion of a cylindrical base portion, wherein an inclined surface intersecting with the long axis direction is formed on a rear side in the long axis direction of the small diameter rod-shaped portion in the flat plate base portion. In addition, since this inclined surface is formed on the rear side of the bolt fixing through hole in the long axis direction, when a force for rotating the chip around the Holt fixing through hole is exerted, a flat plate shape is formed. At least three intersecting ridges at positions apart from the bolt fixing through hole are constrained in the base portion, and each of the intersecting ridges sufficiently exerts the effect of suppressing chip rotation.

As a result, even if the reference surface when the throw-away tip is constrained to the holder is set to either the constraining side surface or the rear end surface of the throw-away tip, the force that pushes the intersecting ridge portion against the holder reference surface. Therefore, it is not firmly fixed to the holder, and the accuracy of the blade tip position is likely to be incorrect.

In addition, when the throw-away tip has a perpendicular line drawn from the center of the bolt fixing through hole toward the inclined surface in a plan view, the perpendicular line intersects the extension line of the inclined surface. In this case, since the inclined surface is formed on the rear side of the bolt fixing through hole in the major axis direction, the moment generated from the component force of bolt tightening from the bolt fixing through hole to the inclined surface. Works in the direction of pressing the throw-away tip against the restraining side surface, and the moment generated from the component force of bolt tightening from the bolt fixing through hole to the restraining side surface works in the direction of pushing the throw-away tip against the restraining side surface.

Therefore, there is a tendency that the rotational force for pressing the throw-away tip toward the restraining side surface becomes large, and the rotational force for pressing the throw-away tip against the holder reference surface can be surely increased. it can.

[Brief description of drawings]

FIG. 1A is a plan view of a throw-away tip of the present invention, and FIG. 1B is a view taken in the direction of arrow X in FIG.

2A is a plan view of an inner diameter processing tool using the throw-away tip of FIG. 1, and FIG. 2B is a Z arrow view of FIG.

3 (a) and 3 (b) are schematic explanatory views showing the action of the throw-away tip of FIG.

FIG. 4 is a plan view of a conventional throw-away tip.

5 is a plan view of an inner diameter processing tool using the conventional throw-away tip of FIG. 4. FIG.

6 (a) and 6 (b) are schematic explanatory views showing the operation of the conventional throw-away tip of FIG.

[Explanation of symbols]

1: Throw-away tip 2: Flat plate-shaped base part 3: Small-diameter rod-shaped part 3a: Side flank surface 4: Through hole for fixing bolt 5: Front end surface 6: Sloping surface 7a: Restraint side surface 7b: Non-restraint side surface 8: Cutting edge portion 9 : Rake surface 21: Inner diameter processing tool 22: Holder 23: Holder upper surface 24: Chip pocket 25: Chip seating surface 26: Bolt 27: Bolt fixing hole 31: Cross ridge 32: Cross ridge 33: Cross ridge 34: An intersection point 35 between a normal line from the center of the through hole to the rear end face and a tangent line to the rear end face 35: An intersection point between the normal line from the center of the through hole to the side face of the restraint part and the side face of the restraint part M: The tip will rotate due to the load on the cutting edge Moment m31: Moment for suppressing the tip rotation generated from the crossing ridge portion m32: Moment that suppresses the tip rotation generated from the crossing ridge portion MA: Mo generated at the crossing ridge portion 32 as a fulcrum when the bolt is tightened Ment MB: Moment generated with the crossing edge 31 as the fulcrum when tightening the bolt

Claims (2)

[Claims] 1. A small-diameter rod-shaped portion is integrally projected from the peripheral surface of a flat-plate-shaped base portion, a cutting edge portion is provided at the tip of this small-diameter rod-shaped portion, and a bolt fixing through hole is provided in the central portion of the flat-plate-shaped base portion. A throw-away tip, wherein in the flat plate-shaped base, an inclined surface intersecting with the long-axis direction is formed on the rear side in the long-axis direction of the small-diameter rod-shaped portion, and the inclined surface is formed in the long-axis direction. A throw-away tip that is formed on the rear side of the bolt fixing through hole. 2. In a plan view of the throw-away tip, when a perpendicular line is drawn from the center of the bolt fixing through hole toward the inclined surface, the perpendicular line intersects with an extension line of the inclined surface. The throw-away tip according to claim 1, which is characterized in that.