JP3166500B2 - Grooving tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grooving tool mainly used for grooving the outer periphery of a workpiece in turning.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show an example of such a conventional grooving cutting tool. The grooving tool shown in these figures is described in Japanese Patent Application Laid-Open No. 62-264808, and has a chip mounting seat 2 provided at the upper end of the holder body 1 of a flat tool holder.
In addition, a flat plate-shaped throw-away tip (hereinafter, referred to as a tip) 3 is detachably inserted. The chip mounting seat 2 is formed from a seating portion 4 extending along the insertion direction of the chip 3 and a clamp portion 5 extending so as to oppose the seating portion 4, while the chip 3 is A cutting edge 6 is formed at the top end of the upper surface, and a lower surface 7 serving as a seating surface for the seating portion 4 is formed along the insertion direction, similarly to the seating portion 4.

[0003] Here, the upper surface of the chip 3 is sequentially arranged on the lower surface 7 in the chip inserting direction so as to be continuous with the base end side (the insertion direction side of the chip 3) of the rake face of the cutting blade 6. A pressed portion 8 made parallel and a guide portion 9 gradually approaching the lower surface 7 toward the base end side are formed, while a clamp portion 5 facing the seating portion 4 of the chip mounting seat 2.
A pressing portion 11 also parallel to the seating portion 4 and a relief portion 12 gradually approaching the seating portion 4 toward the base end are formed on the clamp surface 10 in the order of the chip insertion direction. . Further, a contact portion 13 is formed between the rake face on the upper surface of the chip 3 and the pressing portion 8 with which the tip of the clamp portion 5 contacts.

As shown in FIG. 5, the lower surface 7 of the chip 3, the pressed portion 8, and the guide 9 are formed in a groove shape having a V-shaped cross section. The seating portion 4, the pressing portion 11, and the relief portion 12 are formed in a V-shaped projecting ridge having a cross section engaged with the groove. In this example, the V-shaped included angle θ ₁ formed by the cross section of the seating portion 4 and the pressing portion 11 of the chip mounting seat 2 is the V-shaped included angle formed by the cross section of the lower surface 7 of the chip 3 and the pressed portion 8. It is set to be smaller than θ ₂ , and the seat portion 4 and the lower surface 7, and the pressing portion 11 and the pressed portion 8 are in close contact with each other near the center in the width direction.

In the grooving tool having such a structure, the tip 3 is inserted into the tip mounting seat 2 from the tip side of the holder body 1 of the tool holder, so that the tip 3 of the clamp portion 5 is first inserted into the guide portion 9 of the tip 3. Is climbed up and guided, and the clamp portion 5 is pushed up and bent upward,
Thereafter, the tip of the clamp portion 5 is brought into contact with the contact portion 13 of the tip 3.
When the pressing portion 11 comes into close contact with the pressed portion 8 by contact with the pressing portion 8, the pressed portion 8 is pressed toward the seating surface 4 by the pressing portion by the elastic force of the bending of the clamp portion 5, and the chip 3
Are fixed to the chip mounting seat 2. In this state, a V-shaped ridge formed by the seating surface 4 of the chip mounting seat 2 and the pressing portion 11 of the clamp portion 5, and a V-shaped groove formed by the lower surface 7 of the chip 3 and the pressed portion 8 are formed. Are engaged so that the lateral displacement of the chip 3 is restrained. In this installation state,
Escape portion 1 of guide portion 9 and clamp surface 10 of chip 3
A gap is formed between the two, and they do not adhere to each other.

[0006]

By the way, in the grooving tool having such a structure, the chip 3 is attached to the chip mounting seat 2.
As described above, since the clamp portion 5 is guided by the guide portion 9 of the chip 3 and gradually bent upward as described above, the force required to insert the chip 3 increases as the chip 3 is inserted. This force becomes maximum when the pressing portion 11 of the clamp portion 5 rides on the pressed portion 8.
In this state, the chip 3 must be further pushed in to bring the pressing portion 11 into close contact with the pressed portion 8 and the chip 3 must be clamped. Therefore, there is a problem that mounting the chip 3 requires labor.

Further, in the grooving tool having the above structure, when the clamp portion 5 is guided by the guide portion 8 while being bent in this manner, a portion from the tip of the clamp portion 5 to the pressing portion 11 is formed by the guide portion 8. Is slid while being pressed against this, it is inevitable that wear will occur in this portion while repeatedly inserting and removing the tip 3. However, since the pressed portion 8 on the upper surface of the chip 3 is fixed by being pressed by the pressing portion 11, when the pressing portion 11 is worn, the chip 3 is restrained by the chip mounting seat 2. There is also a problem that the force is remarkably impaired, the stability of the seating of the chip 3 is lost, and the chip 3 tends to fall off.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is possible to easily insert a chip into a chip mounting seat and to prevent deterioration of seating stability of the chip. It is intended to provide a possible grooving tool.

[0009]

In order to solve the above-mentioned problems and to achieve the above object, according to the present invention, a seating portion is provided at a distal end portion of a cutting tool holder so as to face the seating portion. A chip mounting seat including a clamp portion is formed, and a chip having a cutting blade is removably inserted between the seat portion and the clamp portion of the chip mounting seat and is fixed by pressing. In the clamp surface of the clamp portion opposed to the seating portion, in order in the direction of insertion of the chip, a guide portion for guiding the insertion of the chip, and a pressing portion for pressing the chip toward the seating portion side On the other hand, on the upper surface of the chip, a gap is formed between the pressed portion pressed by the pressing portion and the guide portion in the mounted state of the chip in order toward the rear side in the insertion direction. Define It is characterized in that it has formed a lower portion.

[0010]

[Function] In the grooving tool having such a structure,
When the chip is inserted into the chip mounting seat, the pressed part of the chip first contacts the guide part on the tip side of the clamp part, the pressed part is guided by this guide part, and the clamp part is bent upward. Go on. Therefore, as the chip is inserted, the force required to insert the chip increases as in the case of the conventional grooving tool, and the force becomes maximum when the guide reaches the escape portion on the chip upper surface. However, when the tip of the guide portion crosses the intersection of the pressed portion and the escape portion of the chip, a gap is defined between the guide portion and the escape portion, so the force acting on the chip from the guide portion is Gone
As a result, the force required for chip insertion is reduced below the maximum value. Then, by further pushing in the chip with the reduced force, the pressing portion of the clamp portion comes into close contact with the pressed portion of the chip, and the chip is pressed and fixed to the seating portion side of the chip mounting seat. According to the grooving tool, it is possible to insert and fix the chip with a smaller force than before.

Also, in the grooving tool having the above-mentioned structure, the guide portion at the tip of the clamp portion slides on the pressed portion of the chip upper surface in the chip insertion direction to guide the chip. During the repetition, it is inevitable that the tip of the clamp portion is worn as in the related art. However, in the grooving tool, when the chip is fixed, a gap is defined between the guide portion at the tip of the clamp portion and the escape portion of the chip, that is, the guide portion presses the chip. Since there is no involvement in the fixation, even if the guide portion is worn, there is no problem in the binding force and the seating stability of the chip.

[0012]

1 to 3 show an embodiment of a grooving tool according to the present invention. The grooving tool according to the present embodiment is made of a steel material or the like and has a substantially rectangular flat-shaped tool holder.
A chip 23 made of a hard material such as a cemented carbide is detachably inserted into the chip mounting seat 22. The tip mounting seat 22 is provided with the tip 23
And a clamp portion 25 extending straight so as to face above the seat portion 24, and a tip of the clamp portion 25 is substantially above the seat portion 24. It extends to the middle.

In the clamp portion 25, the tip 23 is provided on a clamp surface 26 facing the seat portion 24.
In the insertion direction, that is, in order from the distal end side to the proximal end side of the holder body 21, the guide portion 27 and the pressing portion 2.
8 are provided. Here, each of the guide portion 27 and the pressing portion 28 is formed so as to gradually approach the seating portion 24 toward the chip insertion direction, and the inclination angle with respect to the seating portion 24 is the guide portion 2.
The pressing portion 28 is larger than 7, so that the two intersect at an obtuse intersection angle α, and are formed so as to be bent in a “H” shape in the chip insertion direction. Further, the seating portion 24 of the tip mounting seat 22 and the guide portion 27 and the pressing portion 28 of the clamp portion 25 are formed in a V-shaped projecting ridge shape whose cross sections protrude in directions facing each other. Further, the tip surface 29 of the clamp 25
2 is formed in a convex curved surface curved in the width direction as shown in FIG.

The tip 23 to be inserted into the tip mounting seat 22 is in the form of a small plate having a substantially flat plate shape as shown in FIGS.
The cutting edge 30 is formed along the width direction of No.3. Also,
The lower surface 31 of the chip 23 is a seating surface that is seated in close contact with the seating portion 24 when the chip 23 is mounted on the chip mounting seat 22. Are formed straight along the insertion direction. On the other hand, the cutting blade 30
A rake face 32 is formed so as to be continuous with the rake face 32. Further, on the base end side (chip insertion direction side) of the rake face 32,
The contact portion 33 is formed so as to project one step from the upper surface. In this embodiment, the wall surface 34 of the contact portion 33 facing the chip insertion direction is formed in a flat shape extending in parallel with the cutting blade 30.

On the upper surface of the chip 23, on the chip insertion direction side of the contact portion 33, a relief portion 35 and a pressed portion 36 are formed in this order in the insertion direction. Here, while the relief portion 35 is formed in a direction parallel to the lower surface 31 of the chip 23 in this embodiment,
The pressed portion 36 is formed so as to be inclined so as to approach the lower surface 31 as it goes toward the chip insertion direction, and the inclination angle is such that the tip mounting seat 22 presses the seating portion 24 against the seating portion 24 when the chip is mounted. The angle is set to be equal to the inclination angle of the portion 28. Therefore, like the guide portion 27 and the pressing portion 28, the escape portion 35 and the pressed portion 36 also intersect each other at an obtuse angle and are formed to bend in an "L" shape in the chip insertion direction. The intersection angle β is set to be larger than the intersection angle α between the guide portion 27 and the pressing portion 28.

However, with such a configuration, in the grooving tool of the present embodiment, the tip 23 is attached to the tip mounting seat 2.
2 and the pressed part 36 of the chip 23 is
5, the guide portion 27 of the clamp portion 25 and the escape portion 3 of the tip 23 are pressed.
5, a gap C is formed therebetween as shown in FIG. Then, this gap C
Is set to be in the range of 0.05 mm to 0.5 mm in the present embodiment. Note that this chip 23
The lower surface 31, the escape portion 35, and the pressed portion 36 of
The cross section is formed in a groove shape having a V-shape, and the seat portion 24 and the guide portion 27 of the chip mounting seat 22 are provided.
The protrusion formed by the pressing portion 28 can be engaged in the width direction. However, the included angle of the V-shape formed by the cross section of the groove is
The cross section of the ridge is set to be slightly larger than the V-shaped included angle. The top of the ridge is notched flat as shown in FIG. 3, and when the ridge and the groove come into contact with each other, regardless of whether the ridge and the groove are in contact with each other, the center in the width direction of the ridge, that is, the ridge is formed. An escape will be provided between the top and the bottom of the groove.

In the grooving tool having such a configuration, when the tip 23 is inserted into the tip mounting seat 22,
First, the pressed portion 36 of the tip 23 contacts the tip of the guide portion 27 in the clamp portion of the tip mounting seat 22, and the tip 23 is further inserted therefrom.
7 and the V-shaped groove of the pressed portion 36 engage with each other to guide the chip 23, and the inclined pressed portion 3
The guide portion 27 is pushed up along the line 6 and the clamp portion 2
5 is bent upward, and a pressing force is generated by its elastic force. Then, as the tip 23 is pushed in, the pressing force gradually increases, and the tip of the guide portion 27
At the intersection of the escape portion 35 and the pressed portion 36.

However, when the tip 23 is pushed in from here, in this embodiment, the guide portion 27 of the clamp portion 25 is pressed.
The intersection angle β between the escape portion 35 of the chip 23 and the pressed portion 36 is set smaller than the intersection angle α between the
Since the gap C is defined between the guide portion 27 and the escape portion 35, when the guide portion 27 crosses the above-mentioned intersection between the escape portion 35 of the chip 23 and the pressed portion 36,
No pressing force acts on the chip 23 from the guide portion 27, thereby reducing the force required to insert the chip 23. When the tip 23 is further inserted as it is, the tip surface 29 of the clamp portion 25 contacts the wall surface 34 of the contact portion 33 of the tip 23 to position the tip 23, and the pressed portion 28 presses the clamp portion 25. The chip 23 is pressed in close contact with the portion 28, thereby fixing the chip 23. Therefore, according to the grooving tool having the above configuration,
As described above, since the force required to insert the chip 23 is reduced when the force exceeds the maximum value, the insertion and removal of the chip 23 can be performed with less labor than in the related art. It is possible to improve the work efficiency by reducing the time and labor spent on the work.

In this embodiment, when the chip 23 is mounted, the size W of the gap C defined between the guide portion 27 and the escape portion 35 is set to 0.05 mm to 0.3 mm.
Although the range is set to 5 mm, if the size W is smaller than this range, the clamp portion 25 is moved after the tip of the guide portion 27 crosses the intersection between the escape portion 35 of the chip 23 and the pressed portion 36. Of the tip 23 comes into contact with the contact portion 33
By the time the guide portion 27 is positioned in the escape portion 3
There is a possibility that the above-described effect may be impaired due to the occurrence of a situation in which the contact is made. Conversely, in order to increase the size W of the gap C as it exceeds the above range, in the above embodiment, the inclination angle of the guide portion 27 with respect to the seating portion 24 is increased, or Side, the guideability of the guide portion 27 and the strength of the chip 23 may be impaired.
A gap C may be formed between the escape portion 7 and the escape portion 35 so that they do not come into contact with each other. Therefore, even if the size W is unnecessarily large, the effect to be achieved does not change. Therefore, it is desirable that the size W of the gap C is set within the above range.

On the other hand, also in the grooving cutting tool of the present embodiment, the guide portion 27 is guided by the guide portion 27 when the chip 23 is inserted, and the guide portion 27 and the pressed portion 36 of the chip 23 come into sliding contact with each other. Therefore, similarly to the above-mentioned conventional example, it is inevitable that the tip portion of the guide portion 27 particularly wears during repeated insertion and removal of the chip 23 by replacement or the like. However, in the grooving tool having the above configuration, as described above, the guide portion 2
Reference numeral 7 merely guides the insertion of the chip 23, and the pressing part 28 of the clamp part 25 presses and fixes the chip 23 with the chip 23 mounted, and the guide part 27
Since the gap C is defined between the chip 23 and the escape portion 35 of the chip 23, the gap C is not directly involved in pressing and fixing the chip 23. That is, due to such wear of the guide portion 27, the restraining force of the chip 23 due to the pressing and the chip mounting seat 22
The seating stability of the chip 23 is not affected, and the chip 23 can always be stably held even if the insertion and removal of the chip 23 is repeated frequently, and the chip 23 is detached. And the like, and smooth grooving can be performed.

Further, in the present embodiment, a contact portion 33 is formed on the upper surface of the tip 23 on the tip side of the escape portion 35, that is, on the rear side in the chip insertion direction, to contact the tip surface 29 of the clamp portion 25. The wall portion 34 of the contact portion 33 facing the chip insertion direction is formed in a planar shape, while the distal end surface 29 of the clamp portion 25 is formed in a convex curved shape curved in the width direction. 33 and clamp 25
It comes into contact with the tip by line contact. For this reason, for example, compared to a case where both the wall surface 34 of the contact portion 33 and the distal end surface 25 of the clamp portion 25 are flat and the tip 23 is positioned by contact by surface contact between them, the present embodiment is different from the present embodiment. According to the wall surface 34 and the tip surface 2
There is also an advantage that a relatively high positioning accuracy can be obtained without requiring a strict accuracy in 5. In order to obtain such an advantage, contrary to the present embodiment, the distal end surface 29 of the clamp portion 25 is formed in a planar shape, and the wall surface 34 of the contact portion 33 facing the chip insertion direction is formed to have the width. It may be formed in a convex curved shape curved in the direction.

In this embodiment, the guide portion 27 of the clamp portion 25 of the chip mounting seat 22 is formed so as to approach the seating portion 24 as it goes in the chip insertion direction, while the escape portion 35 on the upper surface of the chip 23 is formed. Are formed in parallel with the lower surface 31 so that the guide portion 2
Although the gap C is defined between the escape portion 7 and the escape portion 35, the present invention is not limited to only such a configuration. That is, if a gap C having a size W desirably in the above-described range is defined between the guide portion 27 and the escape portion 35, the guide portion 27 is made parallel to the seating portion 24, and the escape portion is formed. 35 is formed in a direction away from the lower surface 31 side in the chip insertion direction, or both the guide portion 27 and the escape portion 35 are separated from the seating portion 24 or the lower surface 31 in the chip insertion direction, or It may be formed in the approaching direction.

Further, in the above embodiment, the case where the present invention is applied to a so-called blade-type grooving tool in which the chip 23 is attached to the flat plate-shaped holder main body 21 has been described. The present invention may be applied to a shank type grooving tool in which a flat holder is formed at the tip of a shank having, for example, a prismatic shape.

[0024]

As described above, according to the present invention,
Since the guide part of the clamp part does not contact the escape part of the chip, the pressing force required to insert the chip can be reduced, reducing labor and replacement time in chip replacement etc. Work can be performed. In addition, since the guide portion is not involved in pressing and fixing the chip, even if the guide portion is worn due to sliding contact when guiding the insertion of the chip, the seating stability of the chip is not impaired, The chip can be stably held at all times to prevent the chip from falling off, and smooth processing can be performed.

[Brief description of the drawings]

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

FIG. 2 is a plan view from above of the embodiment shown in FIG. 1;

FIG. 3 is a sectional view taken along the line AA in FIG.

FIG. 4 is a side view showing a conventional grooving cutting tool.

FIG. 5 is a GG sectional view in FIG. 4;

[Explanation of symbols]

 Reference Signs List 21 Holder main body 22 Chip mounting seat 23 Chip 24 Seating part 25 Clamp part 27 Guide part 28 Pressing part 29 Tip surface of clamp part 25 31 Lower surface of chip 23 33 Contact part 34 Wall surface of contact part 33 facing the chip insertion direction 35 Escape portion 36 Pressed portion C Gap defined between guide portion 27 and escape portion 35 W Size of gap C

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-264808 (JP, A) JP-A-6-71505 (JP, A) JP-A-2-39801 (JP, U) JP-A-2,801 19405 (JP, U) JP-A-2-51004 (JP, U) JP-A-2-27803 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23B 27/04 B23B 27 / 16

Claims (4)

(57) [Claims] 1. A tip mounting seat comprising a seating portion and a clamp portion extending so as to face the seating portion is formed at a tip end portion of the tool holder. The seating portion and the clamp portion of the chip mounting seat are formed. A cutting insert having a cutting blade between it and a grooving tool, which is removably inserted and pressed and fixed, wherein the throw-away tip is provided on a clamp surface of the clamp portion facing the seat portion. A guide portion for guiding the insertion of the throw-away tip and a pressing portion for pressing the throw-away tip toward the seat portion are formed in order in the insertion direction, while the upper surface of the throw-away tip is , In order toward the rear side in the insertion direction,
A grooving tool comprising: a pressed portion pressed by the pressing portion; and a relief portion defining a gap between the pressed portion and the guide portion when the indexable tip is mounted. 2. A size of the gap defined between the guide portion and the escape portion in a state where the indexable insert is mounted is set in a range of 0.05 mm to 0.5 mm. The grooving cutting tool according to claim 1, characterized in that: 3. The guide portion and the pressing portion of the clamp surface and the relief portion and the pressed portion of the upper surface of the throw-away tip are formed so as to intersect and bend at an obtuse angle in the insertion direction. And the crossing angle between the guide portion and the pressing portion is set to be larger than the crossing angle between the relief portion and the pressed portion, whereby the gap is defined between the guide portion and the relief portion. The grooving tool according to claim 1, wherein the grooving tool is formed. 4. A contact portion, which is in contact with a tip end surface of the clamp portion, is formed on the upper surface of the throw-away tip behind the escape portion in the insertion direction, and the contact portion is inserted in the insertion direction. 4. The device according to claim 1, wherein one of the wall surface facing the side and the distal end surface of the clamp portion is formed in a convex curved shape curved in the width direction. 5. Grooving tool.