JPH0871809A - Grooving tool, tool holder and throw away tip - Google Patents

Abstract

PURPOSE: To prevent the slip-off and fall of a tip by forming a pressing part in the clamping part of a tip fitting seat and the pressed part of the tip in the direction of being separated from the seat part of the tip fitting seat and the lower face of the tip toward the tip insert direction side. CONSTITUTION: A first and a second pressed parts 31, 32 are formed at the upper face of a tip 23, while a first and a second pressing parts 34, 35 are formed at the clamping face 33 of a clamping part 25. Among these pressed parts 31, 32 and pressing parts 34, 35, the first pressed part 31 and the first pressing part 34 are formed in the direction of being respectively separated from the lower face of the tip 23 and the seat part 24 of a tip fitting seat toward the base end side of a holder body 21, that is, toward the insert direction side of the tip 23. Accordingly, when the first pressing part 34 presses the first pressed part 31 by resilience generated by the flexure of the clamping part 25, the force pressing the tip 23 to the seat face side and the force pressing the tip 23 to the tip insert direction side act upon the tip 23.

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 circumference of a work material in turning, a tool holder constituting the grooving tool, and a throw-away tip ( Hereinafter, it is referred to as a chip).

[0002]

15 and 16 show an example of a conventional grooving tool of this type. This grooving tool is described in JP-A-62-264808, in which a small piece of a flat plate is attached to a tip mounting seat 2 provided at the upper end of a holder body 1 of a flat-shaped tool holder. The chip 3 is detachably inserted. The tip mounting seat 2 is composed of a seating portion 4 extending along the inserting direction of the tip 3 and a clamp portion 5 extending above the seating portion 4 so as to face the seating portion 4, while the tip 3 has a top end portion thereof. The cutting edge 6 is formed on the lower surface 7 and the lower surface 7 serving as a seating surface for the seat 4 is similar to the seat 4.
It is formed along the insertion direction.

Here, the upper surface of the tip 3 is parallel to the lower surface 7 in order toward the base end side so as to be connected to the base end side (the insertion direction side of the tip 3) of the rake face of the cutting edge 6. The pressed portion 8 and the guide portion 9 that gradually approaches the lower surface 7 side toward the base end side are formed, while the tip mounting seat 2 is formed.
On the clamp surface 10 of the clamp part 5 facing the seating part 4, the pressing part 11 parallel to the seating part 4 is also sequentially arranged toward the base end side, and the pressing part 11 is gradually approached to the seating part 4 side toward the base end side. The inclined portion 12 is formed. Also, chip 3
An abutting portion 13 with which the tip of the clamp portion 5 abuts is formed between the above-mentioned rake face on the upper surface of the above and the pressing portion 8.

Further, as shown in FIG. 16, the lower surface 7 of the chip 3, the pressed portion 8 and the guide portion 9 are formed in the shape of a groove having a V-shaped cross section. The seating portion 4, the pressing portion 11, and the inclined portion 12 are formed in a V-shaped ridge shape whose cross section engages with the groove. In this example, the V-shaped included angle θ ₁ formed by the cross sections 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 sections 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 seating portion 4 and the lower surface 7 and the pressing portion 11 and the pressed portion 8 are in close contact with each other in the vicinity of the central portion in the width direction.

In the grooving tool having such a structure, the tip 3 is first inserted into the tip mounting seat 2 from the tip side of the holder body 1 of the tool holder so that the tip of the clamp portion 5 is first guided by the guide portion 9 of the tip 3. While being guided up, the clamp part 5 is pushed up and bent upward, and then the tip of the clamp part 5 contacts the contact part 13 of the chip 3 and the pressing part 11 closely contacts the pressed part 8. By the way,
The pressed portion 8 is pressed by the pressing portion toward the seating surface 4 side by the elastic force of the bending of the clamp portion 5 so that the chip 3 is fixed to the chip mounting seat 1. Also,
In this state, the ridge having a V-shaped cross section formed by the seating surface 4 of the chip mounting seat 2 and the pressing part 11 of the clamp part 5, and the chip 3
The lower surface 7 and the groove having a V-shaped cross section formed by the pressed portion 8 are engaged to restrain the lateral displacement of the chip 3. In this mounted state, a gap is formed between the guide portion 9 of the chip 3 and the inclined portion 12 of the clamp surface 10 so that they do not come into close contact with each other.

[0006]

However, in the grooving tool having such a structure, the abutting portion 1 of the tip 3 is used.
Although the contact of 3 with the tip of the clamp portion 5 of the chip mounting seat 2 restrains the displacement of the chip 3 toward the base end side,
The tip 3 of the holder main body 1, that is, the rear side in the insertion direction of the tip 3, is restricted in its movement only by the pressing force of the pressing part 11 of the clamp part 5 pressing the pressed part 8. is there. Therefore, tip 3
When an excessive load acts in this direction, the constraint due to the pressing force cannot fully withstand this load and the chip 3
However, there was a problem that it would come off from the tip mounting seat 2.

Further, in the grooving tool having the above structure, when the chip 3 is inserted into the chip mounting seat 4, the clamp portion 5 is
As described above, the tip 3 is guided by the guide portion 9 of the chip 3 and is bent upward. In the mounted state, the pressing portion 11 closely contacts and presses the pressed portion 8 to fix the chip 3. However, when the clamp portion 5 is guided by the guide portion 8 while being bent, the portion from the tip of the clamp portion 5 to the pressing portion 11 makes sliding contact with the guide portion 8, so that the tip 3 is repeatedly inserted and removed. It is unavoidable that wear will occur in this part as it goes. However, since the pressed portion 8 on the upper surface of the chip 3 is fixed by being pressed by the pressing portion 11, the pressing portion 1 is fixed.
When the wear occurs in No. 1, the force for restraining the chip 3 on the chip mounting seat 2 is significantly impaired, and in combination with the above problem, the chip 3 is more likely to fall off.

The present invention has been made in view of the above circumstances, and sufficiently resists a load to the rear side in the chip insertion direction, and prevents a decrease in pressing force due to wear of the clamp portion. An object of the present invention is to provide a grooving bite, a bite holder, and a chip capable of preventing the chip from coming off or coming off.

[0009]

In order to solve the above-mentioned problems and to achieve such an object, a grooving tool according to claim 1 of the present invention is provided with a seating portion of a chip mounting seat and a seating portion thereof. The lower surface of the chip, which closely adheres to form a seating surface, is formed in the insertion direction of the chip, and the upper surface of the chip is
A first pressed portion that gradually rises from the lower surface side toward the insertion direction in the order from the cutting edge side toward the insertion direction, and a second pressed portion that gradually approaches the lower surface side toward the insertion direction. And a first pressing portion that presses the first pressed portion and a second pressing portion that presses the first pressed portion on the clamp surface of the clamp portion of the chip mounting seat that faces the seating portion. 2 pressing parts are formed, and at least one of the first pressing part and the second pressing part, and the first pressed part and the second pressed part have different cross-sectional shapes. It is characterized by being formed.

Further, the bite holder according to claim 6 and the tip according to claim 7 of the present invention can constitute such a grooving bite, and the bite holder according to claim 6 is a tip mounting seat. The seating portion is formed straight from the tip of the holder main body toward the base end side, and at the clamping surface of the clamp portion of the tip mounting seat facing this seating portion,
In order from the distal end side to the base end side, a first pressing part that is gradually separated from the seating part side toward the base end side, and a second pressing part that gradually approaches the seating part side toward the base end side. The chip according to claim 7, wherein a cutting edge is formed at the tip of the upper surface of the plate-shaped chip body, and the lower surface of the chip body, which is the seating surface, is formed straight. Then, on the upper surface connected to the base end side of the rake face of the cutting edge, in order toward the base end side, the first pressed portion gradually rising from the lower surface side toward the base end side, and the base end. The second that gradually approaches the lower surface side as it approaches the second side
It is characterized in that a pressed portion is formed.

[0011]

In the grooving tool, the tool holder, and the tip having such a structure, as in the above-described conventional grooving tool, by inserting the tip into the tip mounting seat of the tool holder, the clamp portion is provided on the top surface of the tip. The chip is pressed and fixed by its elastic force. However, in the present invention, while the first and second pressed portions are formed on the upper surface of the chip,
First and second pressing portions are formed on the clamp surface of the clamp portion, and the first pressed portion and the first pressing portion are directed toward the base end side of the holder body, that is, the chip insertion direction side. Accordingly, they are formed in a direction away from the lower surface of the chip and the seating portion of the chip mounting seat, respectively. Therefore, when the first pressing part presses the first pressed part by the elastic force due to the bending of the clamp part, the force of pressing the chip toward the seating surface side and the force of pressing the chip toward the chip insertion direction act accordingly. However, this pushing force in the chip insertion direction side prevents the chip from slipping out toward the tip side.

In the grooving tool, the first and second pressed portions of the chip are formed in different shapes from each other, or the first and second clamp portions for pressing the same are formed.
The pressing portions are formed in different shapes, or both of them are formed in different shapes. Therefore, when the chip is inserted into the chip mounting seat, when the clamp part is guided to the second pressed part on the base end side of the upper surface of the chip, the first pressing part slidably contacts the second pressed part. The portion where the first pressing portion presses the first pressed portion when the chip is fixed is different from the portion. Therefore, according to the grooving tool having such a structure, even when the tip is repeatedly inserted and removed, the portion where the first pressing portion presses the first pressed portion is not worn and is stable for a long period of time. As a result, the pressure fixing force of the chip can be maintained.

[0013]

1 to 14 show one embodiment of a bite holder, a tip, and a grooving bite composed of these, according to the present invention. As shown in FIGS. 1 and 2, the grooving tool of this embodiment is a holder body 2 of a tool holder made of steel or the like and having a substantially rectangular flat plate shape.
1. A tip mounting seat 22 is formed on the top of the tip of the tip 1. The tip mounting seat 22 is made of a hard material such as cemented carbide.
3 is detachably inserted. The tip mounting seat 22 is formed of a seat portion 24 that extends straight along the insertion direction of the tip 23 and a clamp portion 25 that extends above the seat portion 24 so as to face the seat portion 24. The tip of 25 extends to approximately the middle above the seat 24.

The chip 23 mounted on the chip mounting seat 22 has a chip body 26 in the form of a small flat plate as shown in FIGS. 7 to 11. A cutting edge 27 is formed on the upper end of the tip along the width direction of the tip body 26. Further, the lower surface 28 of the chip body 26 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, and like the seating portion 24, It is formed straight along the insertion direction of the chip 23.

On the other hand, a rake face 29 is formed on the upper surface of the tip body 26 so as to be continuous with the cutting edge 27.
Furthermore, the base end side of the rake face 29 (chip insertion direction side)
The contact portion 30 is formed on the upper surface of the upper surface so as to project one step from the upper surface. Then, on the upper surface of the chip body 26, a first pressed portion 31 and a second pressed portion 32 are formed in this order on the base end side of the contact portion 30 toward the base end side. Here, as shown in FIG. 7, the first pressed portion 31 is formed so as to gradually separate from the lower surface 28 and bulge toward the base end side, and an inclination angle α with respect to the lower surface 28. Is set in the range of 1 ° to 10 ° in this embodiment. On the other hand, on the contrary, the second pressed portion 32 is formed so as to gradually approach and descend toward the lower surface 28 toward the base end side, and the inclination angle β with respect to the lower surface 28 is the present embodiment. Is set in the range of 5 ° to 15 °.

Further, the lower surface 2 of the chip body 26.
8 and the first and second pressed portions 31, 32 are each formed in a groove shape having a V-shaped cross section as shown in FIGS. 9 to 11. Here, the groove present on the lower surface 28 is formed so as to extend over the entire length of the lower surface 28 while its cross section has a constant V shape, whereas the first and second pressed portions 31 on the upper surface 31. , 32 present such that the V-shaped included angle θ ₃₂ formed by the cross section of the second pressed portion 32 is smaller than the V-shaped included angle θ ₃₁ formed by the cross section of the first pressed portion 31. Is formed in.

On the other hand, in the clamp portion 25 of the tip mounting seat 22 into which the tip 23 having such a structure is inserted, the clamp surface 33 opposed to the seat portion 24 is provided with the first portion in order in the tip insertion direction. The pressing portion 34 and the second pressing portion 35 are formed. Here, the first and second pressing portions 34 and 35 correspond to the first and second pressed portions 31 and 32 of the chip 23, respectively, and the first pressing portion 3
4 is formed so as to be gradually separated from the seating portion 24 as it goes toward the tip insertion direction side, that is, toward the base end side of the holder main body 21, while the second pressing portion 35 is opposite to the base end side. It is formed so as to gradually approach the seating portion 24 side toward the side. The inclination angle formed by the first and second pressing portions 34 and 35 with respect to the seating portion 24 is the inclination angle α formed by the first and second pressed portions 31 and 32 of the tip 23 with respect to the lower surface 28. , Β are set to be equal to each other.

Further, the seating portion 2 of the tip mounting seat 22
4 and the first and second pressing portions 34.35 are formed in a ridge shape having V-shapes whose cross-sections project in directions opposite to each other. Here, the protrusion provided by the seating portion 24 is
Similar to the V-shaped groove formed by the lower surface 28 of the chip 23, the cross-section is formed so as to extend over the entire length of the seating portion 24 with a constant V-shape. However, the V-shaped included angle formed by this cross section is equal to the V formed by the cross section of the lower surface 28 of the chip 23.
It is set to be slightly smaller than the included angle of the letter shape. on the other hand,
While the V-shaped included angles θ ₃₁ and θ ₃₂ formed by the cross sections of the first and second pressed portions 31 and 32 of the chip 23 are set to different angles, in the present embodiment, the first angle of the clamp portion 25 is set. , Second
The V-shaped cross sections of the pressing portions 34.35 are formed to have the same included angle θ ₃₄ . Further, the V-shaped included angle θ ₃₄ formed by the cross sections of the first and second pressing portions 34 and 35 is the V-shaped included angle θ ₃₁ formed by the cross section of the groove of the first pressed portion 31 of the chip 23. Is set smaller than V, the V formed by the cross section of the groove presented by the second pressed portion 32.
It is set to be large with respect to the included angle θ ₃₂ of the character.

In this embodiment, the V-shaped included angle θ ₃₄ formed by the cross sections of the first and second pressing portions 34 and 35 and the cross section of the first and second pressed portions 31 and 32 are the same. The V-shaped included angles θ ₃₁ and θ ₃₂ are the angle difference θ ₃₁ between the included angles θ ₃₄ and θ ₃₁ between the first pressing portion 34 and the second pressed portion 31 that correspond to each other.
-Θ ₃₄ is in the range of 1 ° to 15 °, and the included angles θ ₃₄ , θ ₃₂ between the second pressing portion 35 and the second pressed portion 32 are small.
The angle difference θ ₃₄ −θ ₃₂ is also set in the range of 1 ° to 15 °. The bottom surface 28 of the chip 23 and the groove bottom portion at the center in the width direction of the V-shaped groove formed by the first and second pressed portions 31, 32 are formed to be recessed one step, while the seat portion 24 of the chip mounting seat 22 and The top of the V-shaped ridge formed by the first and second pressing portions 34 and 35 of the clamp portion 25 at the center in the width direction is notched in a flat surface shape, and when the chip 23 is mounted, the groove bottom and the top are formed. An escape is formed between them.

The bite holder and the tip 23 thus configured constitute the grooved bite of this embodiment by inserting and attaching the tip 23 into the tip mounting seat 22 of the bite holder. The cutting blade 27 provided is used for grooving. The cutting edge 27 is positioned by the tip of the clamp portion 25 coming into contact with the contact portion 30 on the upper surface of the tip 23 when the tip 23 is inserted into the tip mounting seat 22. Here, in the state where the tip 23 is attached, the lower surface 28 of the tip 23 is in close contact with the seat portion 24 of the tip mounting seat 22, and the clamp portion 25 is pushed upward and bent, and the clamp surface 33 is elastically deformed. The first and second pressing portions 34 and 35 respectively press the first and second pressed portions 31 and 32 of the chip 23 to fix the chip 23.

However, in the grooving tool having the above-mentioned structure, the first pressing portion 34 and the first pressed portion 31 of the cutting tool of the tip mounting seat 22 are arranged toward the base end side, that is, in the tip insertion direction. Seat 24 and tip 2
3 is formed in a direction in which it is gradually separated from the lower surface 28 of
When the first pressing portion 34 presses the first pressed portion 31 as described above, the chip 23 is pressed against the seating portion 24 side and receives a force that is also pressed toward the chip insertion direction side. Therefore, even if an excessive load is applied to the tip 23 toward the tip side of the holder main body 21 opposite to the insertion direction, the force applied by the first pressing portion 34 in the insertion direction causes a sufficient load to be applied. It is possible to prevent the chip 23 from coming off or falling off. Therefore, according to the present embodiment, it is possible to prevent a situation in which grooving processing is hindered due to the dropout or dropout of the tip 23, and to perform smooth processing work. It is possible to provide a grooving tool that can perform smooth processing smoothly.

In this embodiment, the lower surface 2 of the chip 23 is used.
The inclination angle α at which the first pressed portion 31 is raised with respect to 8 is 1 °
The angle of inclination β in which the second pressed portion 32 descends is in the range of 5 ° to 15 °, and the first portion of the clamp portion 25 with respect to the seating portion 24 of the chip mounting seat 22 is set to be in the range of 10 ° to 10 °. , The inclination angles formed by the second pressing portions 34, 35 are the inclination angles α, β, respectively, similarly to the above, but the inclination angles α of the first pressed portion 31 and the first pressing portion 34 are too small. Then, there is a possibility that a sufficient pressing force toward the chip insertion direction side may not be obtained. Conversely, if the inclination angle α is too large, the pressing force will increase,
This is because the force that presses the chip 23 toward the seating portion 24 becomes small, and the seating of the chip 23 may become rather unstable. Further, if the inclination angle β is too small, the bending of the clamp portion 25 at the time of inserting the tip also becomes small, and the pressing force based on the elastic force may also become small. Conversely, if the inclination angle β is too large, 2 The guideability of the clamp part 25 by the pressed part 32 is impaired, and it may be difficult to insert the chip 23. Therefore, it is desirable that the inclination angles α and β are set in the above-mentioned ranges, respectively.

On the other hand, in this embodiment, when the chip 23 is mounted on the chip mounting seat 22, the lower surface 28 of the chip 23 is placed on the seat portion 24 as shown in FIG. The groove and the protrusion are engaged with each other, and the tip 23 is inserted into the base end side of the holder main body 21 along the engagement. Then, the tip of the clamp portion 25 first hits the second pressed portion 32 on the base end side of the upper surface of the chip 23, and the tip side ridge line of the V-shaped cross section formed by the first pressing portion 34 of the clamp surface 33 of the clamp portion 25. The portion and the groove having a V-shaped cross section formed by the second pressed portion 32 are engaged with each other. When the tip 23 is pushed in from this state, the tip 23 is guided by the engagement of the first pressing portion 34 and the second pressed portion 32, and the clamp portion 25 is pushed upward and bent. As shown in FIG. 14, the bending of the clamp portion 25 is maximized when the tip side ridge line portion is applied to the intersection of the first pressed portion 31 and the second pressed portion 32 of the chip 23.

However, in the present embodiment, the V-shaped included angle θ ₃₄ formed by the projection of the first pressing portion ₃₄ is set to the second pressed portion 3
Since it is set to be larger than the V-shaped included angle θ ₃₂ formed by the two grooves, in the state in which these ridges and the grooves are engaged, the ridges and the grooves are, as shown in FIG. The portions P on both sides in the width direction are in contact with each other. Then, by further pushing the chip 23 in the insertion direction from here,
The tip ridge portion engages with the V-shaped groove formed by the first pressed portion 31, and the tip 23 is positioned when the tip of the clamp portion 25 abuts the abutting portion 30 of the tip 23. Since the V-shaped included angle θ ₃₁ formed by the groove of the pressing portion 31 is set to be larger than the V-shaped included angle θ ₃₄ formed by the protrusion of the first pressing portion 31, the protrusion of the first pressing portion 34 is formed. When the ridge and the groove of the first pressed portion 31 are engaged with each other, the ridge and the groove are, as shown in FIG.
You will come into contact at Q. In this state, the second
As shown in FIG. 5, the pressing portion 35 is in contact with the second pressed portion 32 of the chip 23 at the portions P, P on both outer sides in the width direction, and presses the second pressed portion 32.

That is, in the grooving tool of this embodiment, since the first pressed portion 31 and the second pressed portion 32 of the chip 23 are formed in different cross-sectional shapes,
A portion of the clamp portion 25 that is in sliding contact with the second pressed portion 32 when the tip of the first pressed portion 34 is guided to the second pressed portion 32, and the first pressed portion 34 is the first pressed portion 31. It means that the part that presses is a different part, and for this reason,
The second pressed portion 3 of the chip 23 when the chip 23 is inserted and removed.
Even if the outer parts P, P of the first pressing portion 34 are worn by sliding contact with the second pressing part 34, the first parts due to the central parts Q, Q
The pressing of the pressed portion 31 does not cause any trouble. Therefore, in the grooving tool having the above structure, even if the chip 23 is frequently inserted and removed, the clamping portion 2
The pressing force by 5 is not impaired, and a high chip pressing fixing force can be maintained for a long period of time.
Then, by the synergistic effect of this and the pressing force of the first pressing portion 34 toward the chip insertion direction side, it is possible to more reliably prevent the chip 23 from slipping out and falling off, and perform more stable and smooth grooving. In addition, it is possible to significantly extend the life of the tool.

[0026] In the present embodiment, first, with respect to the included angle theta ₃₄ of V-shaped ridges of the second pressing portions 34 and 35, included angle of the V-shaped groove of the first pressed portion 31 of the clamp portion 25 greater than this theta _31, although the included angle theta ₃₂ of V-shaped grooves of the second pressed portion 32 is made smaller than this, conversely this included angle theta ₃₄ an included angle theta ₃₁
Even if the included angle θ ₃₂ is set larger than the included angle θ ₃₄ , the tip of the first pressing portion 34 contacts the first and first pressed portions 31, 32 at the time of inserting the chip. The same effect as above can be obtained. However, in the engagement between the groove and the protrusion, both of them are the outer side portions P, P in the width direction.
The stability of the chip 23 is higher at the central side portions Q, Q than at P, and the first pressing portion 34 presses the first pressed portion 31 so that the chip insertion direction is increased. Considering that the pressing force to the side is generated, each of the included angles θ ₃₁ , θ ₃₂ , and θ ₃₄ is set as in the above embodiment, and the width of the first pressing portion 34 and the first pressed portion 31 is set. It is desirable to make contact at the central portions Q, Q in the direction.

Further, in the present embodiment, the V-shaped included angle formed by the cross sections of the ridges of the first pressing portion 34 and the second pressing portion 35 on the side of the clamp portion 25 has the same included angle θ ₃₄ , With the first pressed portion 31 and the second pressed portion 32 on the chip 23 side,
Although the V-shape of the cross section of the groove presented has different included angles θ ₃₁ and θ ₃₂ , conversely, the included angles θ ₃₁ and θ ₃₂ in the first and second pressed portions ₃₁ , ₃₂ are made equal to each other and the first pressing is performed. ₃₅ an included angle theta in the second pressing portion 35 against the included angle theta ₃₄ in section 34
As a result, these included angles θ ₃₄ and θ ₃₅ may be set to different angles. Further, the included angles θ ₃₁ , θ ₃₂ in the first and second pressed portions and the first and second pressing portions 34, 3
The included angles θ ₃₄ and θ ₃₅ in 5 may be set to different angles while maintaining the above relationship.

Further, in this embodiment, the first pressed portion 3 is
The angle difference θ ₃₁ −θ ₃₄ between the V-shaped included angle θ ₃₁ formed by the cross section of No. 1 and the V-shaped included angle θ ₃₄ formed by the cross section of the first pressing portion 34, and the cross section of the second pressed portion 32 are The angle difference θ ₃₄ −θ ₃₂ between the V-shaped included angle θ ₃₂ formed and the V-shaped included angle θ ₃₄ formed by the cross section of the second pressing portion 35 is set to be in the range of 1 ° to 15 °. When the angle differences θ ₃₁ −θ ₃₄ and θ ₃₄ −θ ₃₂ are too large, the pressing portions 34 and 35 and the pressed portions 31 and 3 are
The size of the parts P and Q that come into contact with 2 becomes too small,
This is because a sufficient pressing force may not work or the seating stability of the tip 23 may be impaired. On the contrary, if these angle differences θ ₃₁ −θ ₃₄ and θ ₃₄ −θ ₃₂ are too small, the contact portions P and Q between the pressing portions 34 and 35 and the pressed portions 31 and 32 will overlap. , The above first
This is because there is a possibility that the effect of differentiating the contact portion between the pressing portion 34 and the first and second pressed portions 31, 32 may not be sufficiently achieved. Therefore, it is desirable that the angular differences θ ₃₁ −θ ₃₄ and θ ₃₄ −θ ₃₂ are also set within the above range. This is because the included angles θ ₃₁ , θ ₃₂ , θ
_{The same} applies when the magnitude relationship of ₃₄ or θ ₃₅ is variously changed as described above.

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

[0030]

As described above, according to the present invention,
The first pressing portion of the clamp portion of the chip mounting seat and the first pressed portion of the chip move away from the seating portion of the chip mounting seat and the bottom surface of the chip as they move toward the chip insertion direction, that is, toward the base end side of the holder body. Since the first pressing portion presses the first pressed portion, a force for pressing the chip toward the insertion direction acts on the chip. Therefore, even if a load acts on the chip in such a direction as to push it toward the tip side from the chip mounting seat, the chip can be held against the load due to this pressing force, so that the chip does not come off. It is possible to perform smooth processing by preventing the falling and the falling. Further, when the chip is inserted, since the part where the first pressing part of the clamp part comes into contact with the first pressed part of the chip and the part where the second pressed part comes into contact with each other are different, the wear caused by the insertion and removal of the chip As a result, it is possible to prevent the pressing force of the first pressing portion from being impaired, and in combination with the pressing force, it is possible to always hold the tip stably and to extend the tool life.

[Brief description of drawings]

FIG. 1 is a side view of a grooving tool according to an embodiment of the present invention.

2 is a front view from the tip side of the embodiment shown in FIG. 1. FIG.

FIG. 3 is an enlarged side view of the vicinity of the chip mounting seat 22 of the embodiment shown in FIG.

4 is a cross-sectional view taken along the line AA in FIG.

5 is a sectional view taken along line BB in FIG.

6 is a sectional view taken along line CC in FIG.

FIG. 7 is a side view of the chip 23 showing an embodiment of the present invention.

8 is a plan view from the upper surface side of the chip 23 shown in FIG.

9 is a front view of the tip 23 shown in FIG. 7 viewed from the front end side.

FIG. 10 is a DD cross-sectional view of FIG.

11 is a cross-sectional view taken along the line EE in FIG.

FIG. 12 is a side view showing a state in which the tip 23 is inserted into the bite holder.

13 is a sectional view taken along line FF in FIG.

FIG. 14 is a side view showing a state where the bending of the clamp portion 25 is maximized when the tip 23 is inserted.

FIG. 15 is a side view showing a conventional grooving tool.

16 is a cross-sectional view taken along the line GG in FIG.

[Explanation of symbols]

21 Holder Main Body 22 Tip Mounting Seat 23 Throwaway Tip 24 Seating Part 25 Clamping Part 26 Chip Body 27 Cutting Edge 28 Lower Surface (Seating Surface) 31 First Pressed Part 32 Second Pressed Part 34 First Pressed Part 35 Second Pressed Part α Angle of inclination made by the first pressed portion 31 with respect to the lower surface 28 β Angle of inclination made by the second pressed portion 32 with respect to the lower surface 28 θ ₃₁ , θ ₃₂ First and second pressed portions 31, 32 V-shaped included angle of cross section of groove to be presented θ ₃₄ V-shaped included angle of cross section of protrusion presented by first and second pressing portions 34 and 35

Claims (8)

[Claims] 1. A tip mounting seat including a seating portion and a clamp portion extending so as to face the seating portion is formed at a tip portion of the cutting tool body, and the seating portion and the clamp portion of the tip mounting seat are formed. In a grooving bite in which a throw-away tip having a cutting edge is removably inserted and is pressed and fixed between the above-mentioned seat and the above-mentioned throw which is closely attached to the seat to form a seating surface. The lower surface of the away tip is formed in the insertion direction of the throw-away tip, and the upper surface of the throw-away tip has the lower surface in the order from the cutting edge side to the insertion direction and in the insertion direction. The first pressed portion that gradually rises from the side, and the second that gradually approaches the lower surface side in the insertion direction.
A first pressing portion that presses the first pressed portion and a second pressing portion that presses the first pressed portion are formed on the clamp surface of the clamp portion that is formed with the pressed portion and that faces the seating portion. Two
A pressing part is formed, and at least one of the first pressing part and the second pressing part, and the first pressed part and the second pressed part has different cross-sectional shapes. Grooving tool characterized by being formed. 2. The tilt angle at which the first pressed portion is raised with respect to the lower surface of the throw-away tip is in the range of 1 ° to 10 °, and the second pressed portion is moved with respect to the lower surface. The grooving tool according to claim 1, wherein the descending inclination angle is in the range of 5 ° to 15 °. 3. The first and second pressed portions are formed in a groove shape having a V-shaped cross section, and the first and second pressing portions are formed in a ridge shape having a V-shaped cross section that engages with the groove. Has been formed,
When the V-shaped included angle formed by the cross sections of the first and second pressing parts is used as a reference, the V-shaped formed angle formed by the cross sections of the first and second pressed parts is one pressed part. The included angle is set to be greater than the included angle of the one pressing portion that presses it, and the included angle of the other pressed portion is set to be smaller than the included angle of the other pressing portion that presses it. The grooving tool according to claim 1 or 2, characterized in that 4. The V-shaped included angle formed by the cross sections of the first pressing portion and the second pressed portion of the clamp surface is equal to each other, and the V-shaped included angle formed by the cross section of the first pressed portion is also defined. Is greater than the V-shaped included angle formed by the cross section of the first pressing portion, and the V-shaped included angle formed by the cross section of the second pressed portion is the V-shaped included angle formed by the cross section of the second pressing portion. The grooving tool according to claim 3, wherein the grooving tool is set smaller than the above. 5. An angle difference between a V-shaped included angle formed by the cross section of the first pressed portion and a V-shaped formed angle formed by the cross section of the first pressing portion, and a cross section of the second pressed portion. The angle difference between the V-shaped included angle formed and the V-shaped included angle formed by the cross section of the second pressing portion is in the range of 1 ° to 15 °. Grooving tool. 6. A tip mounting seat including a seating portion and a clamp portion extending so as to face the seating portion is formed at a tip end portion of the holder body, and the seating portion extends from the tip end of the holder body. The clamp surface of the clamp portion, which is formed straight toward the base end side and faces the seating portion, has a sequence from the distal end side toward the base end side, and from the seating side toward the base end side. A bite holder having a first pressing portion that is gradually separated and a second pressing portion that is gradually closer to the seating portion side toward the base end side. 7. A cutting edge is formed at the tip of the upper surface of a flat plate-shaped tip body, and a lower surface of the tip body, which is a seating surface, is formed straight and is provided on the base end side of the rake surface of the cutting edge. On the continuous upper surface, a first pressed portion that gradually rises from the lower surface side toward the proximal end side in order toward the proximal end side, and a first pressed portion that gradually approaches the lower surface side toward the proximal end side. 2. A throw-away tip that is characterized in that a pressed portion is formed. 8. The first pressed portion and the second pressed portion are
The throw-away tip according to claim 7, wherein the cross-sectional shapes are different from each other.