JPH10217004A - Throwaway cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To limit the operation direction so that a tip is not fixed by turning a pin lock type crank pin in the wrong direction by mistake. SOLUTION: The tip 5 on the tip seating recess section arranged at the top of the tip section of a shank 1 has a mechanism, in which an eccentric pin 12, which is engaged with the mounting hole of a tip to be placed on a seat member 7, presses the tip 5 against the wall face in the side of the seat recess section by turning a crank pin 10, and a U-like groove 13, in which a steel ball sinks, is provided in the outer periphery of the crank pin 10 in the effective operation broad angle range of the crank pin 10, and a steel ball 18 to be engaged in the U-like groove 13 is inserted in the tip of the screwed hole 17 orthogonally crossing the through hole 8 made in the shank 1. The turning direction of the crank pin 10 is limited by positioning the steel ball 18 by means of a set bolt 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp mechanism for fixing a throw-away tip (hereinafter, simply referred to as a tip) as a cutting edge in various cutting tools.

[0002]

2. Description of the Related Art Means for fixing a tip to a shank are roughly classified into a clamp-on type in which a presser foot is fixed and a pin lock type in which the eccentricity of a crankpin is used to fix the tip. Further, the pin lock method is classified into a one-side constraint type and a two-side constraint type depending on the form of the chip.

[0003] Japanese Utility Model Publication No. 47-9428 proposes a configuration in which a chip is devised so as to come into contact with a side wall surface earlier than a sheet member in a pin lock system. FIG. 4 is a side view showing an outline of the crankpin 109, and FIG. 5 is a side view in which the crankpin 109 is incorporated.

In this configuration, the tip 108 is displaced from the axis 113a of the base 113 of the crankpin 109 by the amount of deviation of the axis 114a of the flange 114, which is the first eccentric part for pressing the sheet member 106. Second eccentric pin 1
The amount of deviation of the fifteen shaft cores 115a is larger. A crank pin 109 as shown in FIG. 4 is inserted into a through hole 110 provided in the shank 101 in FIG.
08 and the sheet member 106, and the crankpin 10
When the nozzle 9 rotates, the chip 108 comes into contact with the side wall surface 103 first, and has an effect of being securely fixed.

[0005]

FIG. 6 is a view for explaining the operating principle of the pin lock system in the prior art, and shows a plan view of the tip of the shank 1 to which the tip 5 is fixed. The tip 5 is a distance e from the axis O ₁ of the crankpin.
An eccentric pin 12 having an axis centered on the eccentric O ₂ is inserted into the tip mounting hole 6, and the crank pin is rotated clockwise as shown by an arrow to abut against the wedge-shaped side wall surface 3 and fixed. I have.

In this case, the optimum fixing position (bottom dead center) of the eccentric pin 12 is determined by the intersection of the two side wall surfaces 3 and the eccentric pin 12.
Axis O ₂ and the axis O ₁ of the crank pin is ideal to present on the working line A-A leading to a straight line. However, it is difficult to realize this mode due to a manufacturing error of each component constituting the pin lock system. Even if it is realized, it will break down during the progress of the wear of the components involved and the replacement with another chip 5.

Therefore, practically, the dimensional design is such that a margin is left by the angle α to be fixed on the line of action BB. The tip 5 is set to be opened at a position returned to the angle β on the action line CC. Therefore,
The effective operating fan angle of the crankpin may be set to approximately 80 ° to 90 ° which is in the range of α + β.

However, when the clamp position setting function of the present invention is not provided, the tip 5 is apparently fixed even if the crankpin is turned counterclockwise in the direction opposite to the arrow in FIG. The problem described below occurs.

[0009] The form of the insert is a quadrilateral which is suitable for heavy-cutting, a triangular shape which is suitable for heavy-duty cutting and a double-sided processing including corners, and which is suitable for light cutting of nuance and details. Although there is a rhombus or the like, a description will be given of an example of a two-sided constraint type for fixing a rhombus chip in which a problem easily occurs.

FIG. 7A shows a state in which the tip 5 is correctly fixed in the seating recess 2 at the tip of the shank 1 by rotating the crankpin clockwise as shown by the arrow.
It shows a state in which it is rotated counterclockwise and apparently fixed.

In FIG. 7A, the tip 5 is rotated by rotating the crank pin in the direction of the arrow, leaving a margin of an angle α from the optimum fixing position of the eccentric pin 12, and the two eccentric pins 12 3 and is fixed. However, FIG.
In (b), the crank pin rotates counterclockwise as indicated by the arrow, and the tip 5 is apparently acted on by the eccentric pin 12.
−B, but a gap of ΔY is generated between one side wall surface 3 and the side surface of the chip 5 so that the cutting edge 5a
Are projected by ΔX compared to the normal state. In the fixed state as shown in FIG. 7B, when receiving cutting resistance, the chip 5 easily falls off.

The present invention is intended to restrict the rotation direction of the crankpin to a predetermined direction in order to prevent the above-mentioned problem.

[0013]

The tip on the seat recess of the tip located above the tip of the shank is mounted on the seat member and the eccentric pin engaging with the mounting hole of the tip rotates the crank pin. Doing so forms a clamp mechanism that presses and fixes the chip against the side wall surface of the seating recess, and provides a U-shaped groove in which a steel ball sinks, on the outer periphery of the crankpin in the effective operating fan angle range of the crankpin, A steel ball engaging with the U-shaped groove is inserted into the tip of a screw hole orthogonal to the through hole formed in the shank, and the turning direction of the crankpin is restricted by positioning with a set bolt.

It is preferable that the set bolt is screwed at a position where the steel ball idles in a U-shaped groove on the outer periphery of the crank pin, and is fixed by a detent bolt.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When fixing a tip in a seat recess of a shank by a pin lock method, a steel ball is engaged with a U-shaped groove on the outer periphery of the crank pin in order to limit the rotation direction of the crank pin. This is positioned with a set bolt. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a plan view showing the vicinity of the seating recess 2 of the tip 5 of the shank 1 according to the pin lock system of the present invention.
The tip 5 inserts an eccentric pin 12 having an axis at O ₂ eccentric by a distance e from the axis O _{1 of} the crank pin 10 into the tip mounting hole 6, and rotates the crank pin 10 clockwise as indicated by an arrow. Then, the chip 5 is brought into contact with the wedge-shaped side wall surface 3 and fixed. At this time, the fixed position of the eccentric pin 12 is the action line B leaving an α angle margin from the action line AA of the optimum fixed position.
It is preferable to set on -B.

FIG. 2 is an enlarged cross-sectional view of the shank 1 of FIG. Below the chip 5, slightly smaller sheet member 7 than the contour of the chip 5 is seated on the bottom 4 fitted to the axis O ₁ and the flange 11 on the concentric crank pin 10. The material of the seat member 7 is generally a cemented carbide like the tip 5, and protects the tip of the seating recess 2 and the surface of the bottom 4 of the shank 1 made of tool steel.

The crank pin 10 is formed by fitting the seat member 7 to the flange 11 of the crank pin 10 and forming a round snap ring 16.
Is inserted into the through hole 8 provided in the bottom surface 4 of the seating recess 2 in a state of being fitted in the groove 14. At that time, a round snap ring 1
6, the diameter of the crank pin 10 is temporarily reduced along the inner diameter of the through hole 8, but reaches the stepped hole 9 and spreads, whereby the crank pin 10 is positioned. The tip 5 has a tip mounting hole 6 with respect to the eccentric pin 12.
Once rotates the clamp pin 10 to an angle that allows it to be loosely inserted, and again rotates using the prism 15 in the direction of the arrow shown in FIG. 1 to fix it on the action line BB.

In the outer peripheral direction of the intermediate portion of the crankpin 10,
The range of α + β corresponding to the effective operating fan angle of the crank pin 10, the shallow U-shaped groove 1 in which the steel ball 18 sinks about ４ to ３
3 is provided, drilled screw hole 17 perpendicular to the rear surface Z of the tip of the shank 1 the axis O ₁ of the crank pin 10, the steel ball 18 is disposed for engagement with the U-shaped groove 13 at its distal end, The steel ball 18 is locked at a position where the steel ball 18 idles by a set bolt 19,
This is fixed with a detent bolt 20. Also, an effect similar to that of the detent bolt 20 can be achieved by interposing an elastic material between the set bolt 19 and the steel ball 18 and applying a light preload to both.

FIG. 3 is an enlarged plan view around the U-shaped groove.
An eccentric pin 12 having an axis O ₂ at a position eccentric from the axis O ₁ of the crank pin 10 by a distance e shows a state in which the tip 5 is fixed. Axis O ₁ and the eccentric pin 1 line of action B-B and the crank pin 10 connecting the steel ball 18 and threaded hole 17
The action line connecting the _two shaft centers O ₂ does not need to be on a straight line, and the screw hole 17 may be arranged at a position orthogonal to the shaft center O ₁ of the crankpin 10. Toward the rear Z workability good tip of the shank 1 of the set bolt 19 to the axis O ₁ of the crank pin 10, it is common to drilling the screw hole 17. When the crank pin 10 is reversely rotated to the action line C-C, the tip 5 can be inserted into the eccentric pin 12 and the tip mounting hole 6.
Becomes loose and can be replaced. However, even if the crank pin 10 is rotated counterclockwise, which is opposite to the normal rotation direction, to fix the tip 5, the operation is impossible because the steel ball 18 and the set bolt 19 in the U-shaped groove 13 hinder the operation. .

[0021]

According to the present invention, a steel ball is engaged with a U-shaped groove on the outer periphery of a crankpin to fix a tip in a seating recess of a shank so as to limit the direction of rotation of the crankpin, and is set. Since the positioning is performed by the bolts, the tip can always be fixed at the correct clamp position without erroneously operating the rotation direction of the crank pin.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an embodiment of the present invention.

FIG. 3 is an enlarged plan view of the embodiment of the present invention.

FIG. 4 is a side view of a conventional crankpin.

FIG. 5 is a side view of a conventional example.

FIG. 6 is a plan view illustrating the operation principle of a conventional example.

FIG. 7A is a plan view when a conventional chip is correctly fixed. (B) A plan view when a conventional chip is incorrectly fixed.

[Explanation of symbols]

 1: Shank 2: Seating recess 3: Side wall surface 4: Bottom surface 5: Tip 6: Tip mounting hole 7: Sheet member 8: Through hole 9: Stepped hole 10: Crank pin 11: Flange 12: Eccentric pin 13: U Figure groove 14: groove 15: prismatic part 16: round snap ring 17: screw hole 18: steel ball 19: set bolt 20: detent bolt

Claims (2)

[Claims] 1. A seating recess of a throw-away tip disposed at an upper end of a shank is formed by two wedge-shaped side walls and a bottom surface having a through-hole into which a crankpin is inserted. The throw-away tip is a clamp mechanism in which an eccentric pin placed on a sheet member and engaged with a mounting hole of the throw-away tip presses and fixes the throw-away tip against the side wall surface by rotating a crank pin. At the outer periphery of the crankpin in the effective operating fan angle range of the crankpin, a U-shaped groove in which a steel ball sinks is provided, and the U-shaped groove is formed at the tip of a screw hole orthogonal to the through hole formed in the shank. A throwaway bite that inserts a steel ball to be engaged and positions it with a set bolt to enable setting of the clamp position. 2. The bolt according to claim 1, wherein the set bolt is screwed at a position where the steel ball idles in a U-shaped groove on the outer periphery of the crank pin, and is fixed by a detent bolt. The throwaway byte described in.