JP2009184086A - Throw-away tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a copying with a throw-away tip in a wide area. <P>SOLUTION: In the throw-away tip in a substantially flat lozenge plate shape, at least one clearance surface 3 of a plurality of clearance surfaces 3 has: a first clearance surface 3a arranged near a sharp angle corner part 6 of a tip body 1; a second clearance surface 3b arranged at an obtuse angle corner part 7 side of the tip body 1 from the first clearance surface 3a; and a third clearance surface 3c arranged between the first clearance surface 3a and the second clearance surface 3b. A clearance angle α1 of the first clearance surface 3a is larger than a clearance angle α2 of the second clearance surface 3b and cross ridge line parts of the first, second and third clearance surfaces 3a, 3b, 3c and a rake face 2 form the same cutting edges 4 on the same straight line in an upper plane view. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a throw-away tip that is detachably mounted on a cutting tool or the like as a cutting blade and used for turning, and particularly relates to a throw-away tip that is suitably used for copying that performs cutting along the final shape of a product. It is.

Conventionally, as a throw-away tip used for outer diameter copying, a diamond-shaped positive tip having an apex angle of 35 °, such as VBMT160404 defined in JIS B4121, is known (for example, see Non-Patent Document 1).
When this diamond-shaped positive tip is used, the cutting edge angle is as small as 35 ° and has a positive clearance angle, so avoid interference with the workpiece and use it for cutting of relatively complicated shapes. Can do.
JIS Handbook (5) Tool, Japanese Standards Association, 2006, p. 1047

  However, recently, when cutting along the final shape of the product due to downsizing and complexity of the product, there is a tendency to be more severely restricted during processing, and the conventional diamond-shaped positive tip is specified in JIS It was difficult to avoid contact with the work material simply by attaching to one type of tool holder. In other words, when performing thinning, taper processing, etc. with great restrictions during processing, it is necessary to use a plurality of bite holders with different throw-away tip mounting angles. There was a problem that processing accuracy deteriorated due to deviation. Further, since the number of types of tool holders to be used increases, there is a problem that the tool cost increases and the tool management becomes complicated. Furthermore, since the number of work processes increases, there is a problem that the production efficiency is poor and the production cost cannot be reduced.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a throw-away tip that can be used in a wide processing area when performing copying.

In order to achieve the above object, the present invention provides the following means.
The present invention is a substantially rhomboid flat chip body, a rake face provided on the upper surface of the chip body, the rake face provided on each side of the chip body intersecting the rake face, A throw-away tip provided with a cutting edge provided at a crossing ridge line portion between the rake face and the flank face, wherein at least one flank face of the plurality of flank faces is near an acute corner portion of the tip body. A first flank provided; a second flank provided closer to the obtuse corner portion of the chip body than the first flank; and the first flank and second flank A flank angle of the first flank surface is larger than the flank angle of the second flank surface, and the first, second and second The intersection ridgeline between the flank 3 and the rake face is on the same straight line when viewed from above. It forms the same cutting edge to provide a throw-away tip according to claim.

Since the throw-away tip according to the present invention is formed in a substantially rhombic flat plate shape having a small apex angle compared to other shapes, it is possible to perform biting processing while avoiding unnecessary contact with the work material. . Therefore, it can be suitably used for outer diameter copying.
In this case, according to the present invention, the work material is provided with the first flank having a larger flank than the second flank in the vicinity of the acute corner that will be mainly involved in cutting. Can be avoided. For this reason, the present invention can also be applied to thinning processing, taper processing, and the like, which have large processing restrictions.
Therefore, it can be used in a wide processing area.

In addition, since the second flank having a smaller flank than the first flank is provided, a tip that becomes a seating surface when attached to the tool body as compared with a case where the entire flank has a large flank. The area of the lower surface of the main body can be increased. As a result, a stable restraining force on the tool body can be obtained, and the mounting rigidity is excellent. Moreover, by comprising in this way, it is excellent in chip | tip rigidity compared with the case where the whole flank is made into the big flank angle.
In addition, since the third flank that connects the first flank and the second flank with different flank angles is formed, the flank angle does not change suddenly on one flank. Thereby, the loss | disconnection of the throwaway tip which arises when the stress at the time of a cutting process concentrates on the change part can be prevented.

In the said invention, it is good also as a blade angle | corner which a pair of cutting blade which opposes on both sides of the said acute angle corner part makes 20 degrees or more and 60 degrees or less.
Moreover, in the said invention, it is good also as satisfy | filling the following relational expression (1).
0 ° <α1 ≦ 17 ° (1)
Here, α1 is the clearance angle of the first flank.
Moreover, in the said invention, it is good also as satisfy | filling the following relational expression (2).
0 ° ≦ α2 ≦ 11 ° (2)
Here, α2 is a clearance angle of the second flank.

Moreover, in the said invention, it is good also as satisfy | filling the following relational expression (3).
L1 + W ≦ B / 2 (3)
Here, B is from the intersection (O) on the extension line of the two sides facing each other across the acute corner portion on the rake face to the intersection (P) on the extension line of the two sides facing each other across the obtuse corner portion. , L1 is the distance from the intersection (O) to the rear end of the first flank adjacent to the third flank on the cutting edge, and W is the first flank on the cutting edge. The distance from the front end of the third flank adjacent to the surface to the rear end of the third flank adjacent to the second flank.
Moreover, in the said invention, it is good also as satisfy | filling the following relational expression (4).
0mm <W ≦ B / 2-L1mm (4)

  According to the throw-away tip of the present invention, there is an effect that it can be used in a wide processing area when performing copying.

Hereinafter, an embodiment of a throw-away tip according to the present invention will be described with reference to FIGS. 1 and 2.
The throw-away tip according to the present embodiment is composed of cemented carbide, cermet, ceramics, diamond sintered body, cubic boron nitride (cBN) sintered body, etc., as shown in FIG. Chip body 1, rake face 2 provided on the upper surface of the chip body 1 having a substantially rhombus shape, and flank 3 provided on each of the four side surfaces of the chip body 1 intersecting the rake face 2. And a positive tip including a cutting edge 4 provided at a crossing ridge line portion between the rake face 2 and the flank face 3 and a seating face 5 provided on the lower surface of the tip body 1.

  As shown in FIGS. 1 and 2A, the chip body is formed, for example, in a substantially rhombic flat plate shape having an apex angle ε of 35 ° when viewed from above. The length B of the chip body corresponding to the dimension of one side of the substantially rhomboid surface, that is, two sides facing each other across the obtuse corner portion 7 from the intersection O on the extension line of the two sides facing each other across the acute corner portion 6 when viewed from above. The distance B to the intersection P on the extension line is, for example, 16.6 mm.

  A chip breaker 8 is formed on the rake face 2 for breaking the chips flowing out along with the cutting into appropriate small pieces. The chip breaker 8 includes, for example, a breaker groove 8a provided along the cutting edge on the inside of the four sides of the substantially rhomboid surface, and a breaker protrusion 8b protruding toward the acute corner portion.

  As shown in FIGS. 1 and 2 (c), each of the four flank surfaces 3 includes a first flank surface 3a provided in the vicinity of the acute corner portion 6 of the chip body 1, and the first flank surface 3a. A second flank 3b provided closer to the obtuse corner portion 7 of the chip body 1 than the flank 3a, and a third flank provided between the first flank 3a and the second flank 3b. The flank 3c is formed. Each of the four first, second, and third flank surfaces 3a, 3b, and 3c is the top of the chip body 1 across the two acute corner portions 6 as shown in FIG. 2 (b). It arrange | positions so that it may become symmetrical with respect to the bisector of a direction.

As shown in FIG. 3, the first clearance surface 3a has a positive clearance angle larger than the clearance angle α2 of the second clearance surface 3b. The clearance angle α1 is, for example, 11 Formed at °.
The range L1 where the first flank 3a is formed, that is, the third flank 3c on the cutting edge 4 from the intersection O on the extension line of two sides facing each other across the acute corner portion 6 on the rake face 2; The distance L1 to the rear end of the adjacent first flank 3a is, for example, 4.0 mm, which is less than half the length B of the chip body 1, as shown in FIGS. 1 and 2A. Yes.
Therefore, the following relational expression (3) is satisfied.
L1 + W ≦ B / 2 (3)

As shown in FIG. 3, the second flank 3b has a flank angle smaller than the flank angle α1 of the first flank 3a. The flank angle α2 is, for example, 5 °. Is formed.
Range L2 in which the second flank is formed, that is, the second flank adjacent to the obtuse corner portion 7 from the front end of the second flank 3b adjacent to the third flank 3c on the cutting edge 4. The distance L2 to the rear end is, for example, 12.6 mm, which corresponds to half or more of the length B of the chip body 1, as shown in FIG. 1 and FIG.

The third flank 3c is composed of a plane that linearly connects the first flank 3a and the second flank 3b with different flank angles α, and the flank angle α1 of the first flank 3a is The clearance angle α is formed so as to continuously change between the clearance angle α2 of the second clearance surface 3b.
From the front end of the third flank 3c adjacent to the first flank 3a on the cutting edge 4, which corresponds to a range in which the width W of the third flank 3c, that is, the clearance angle α continuously changes, is second. The distance W to the rear end of the third flank 3c adjacent to the flank 3b is within a range obtained by subtracting the range L1 in which the first flank 3a is formed from half the length B of the chip body 1. The width is W, for example, 0.5 mm.
Therefore, the following relational expression (4) is satisfied.
0mm <W ≦ B / 2-L1mm (4)

  As shown in FIG. 2 (a), the cutting edge 4 is composed of two pairs of linear cutting edges extending symmetrically across the two acute corner portions 6 in a top view, and the pair of linear cutting edges. Is composed of a main cutting edge 4a and a sub cutting edge 4b which are adjacent to each other with the acute corner portion 6 interposed therebetween. As shown in FIG. 2 (b), the one cutting edge that becomes the main cutting edge 4a or the auxiliary cutting edge 4b includes the intersection ridge line portion between the first flank 3a and the rake face 2, and the third flank. The intersecting ridge line portion between the surface 3c and the rake face 2 and the intersecting ridge line portion between the second flank 3b and the rake face 2 are arranged on the same straight line when viewed from above. Further, the edge angle ε formed by the pair of straight cutting edges, that is, the main cutting edge 4a and the sub cutting edge 4b is set to 35 °, for example. In addition, it is preferable that the said cutting edge 4 is a honing blade which gave roundness or a small chamfer.

The seating surface 5 is formed in a substantially rhombus shape so that the basic shape excluding the acute corner portion 6 becomes a similar shape obtained by reducing the rake surface 2.
In other words, the throw-away tip according to the present embodiment is a diamond-shaped throw-away tip (for example, VBMT160404 defined in JIS B4121) with a cutting edge angle ε standardized in JIS of 35 ° and a clearance angle of 5 °. It has a basic shape (see FIG. 2 (a) and FIG. 4 (b)).
Then, for example, after being attached to a clamp bit (1206 defined in JIS B0107) standardized in JIS, etc., it is fixed to a lathe as a turning tool, and outer diameter machining, outer diameter copying, inner diameter machining Used for turning such as end face machining.

The operation of the throw-away tip according to the present embodiment configured as described above will be described below.
According to the throw-away tip according to the present embodiment, the cutting edge angle ε is as small as 35 °, and the flank 3 is provided with a clearance angle α of 5 ° or more, so unnecessary contact with the work material is avoided. Then, the biting process can be performed. Therefore, it can be suitably used for outer diameter profiling that performs processing in accordance with a prescribed product shape.

  In this case, the throw-away tip according to the present embodiment is provided with a positive clearance angle α on the first flank 3a disposed in the vicinity of the acute corner portion 6 that will be mainly involved in cutting, Since the clearance angle α1 is as large as 11 °, it is possible to prevent interference with the work material in a wide range. Therefore, even when cutting along the final shape of products with complex shapes and small parts, even when it is necessary to perform thinning processing, taper processing, etc. with great restrictions during processing during cutting, This can be dealt with by using only one bit with the throw-away tip according to the present embodiment as it is. As a result of expanding the machining area that can be cut with a single tool in this way, a desired product shape can be obtained without having to replace the tool on the way, so that machining accuracy and machining efficiency are improved. Therefore, even complex and fine products that require high processing accuracy can be manufactured at low cost in a short time.

  On the other hand, in the conventional slowway tip 10 in which the clearance angle of the entire flank 11 is 5 ° (see FIG. 4A), it comes into contact with the work material. It is necessary to replace with another bite holder with a different clearance or another throw-away tip with a large clearance angle. For this reason, the cutting edge position may be displaced, resulting in poor processing accuracy. In addition, since the number of manufacturing steps is large and the processing efficiency is low, it is not possible to reduce the manufacturing cost. In addition, the number of tool points is large and the tool management becomes complicated.

  Further, as shown in FIG. 2B, two first flank surfaces are provided on the main cutting edge 4a side and the sub cutting edge 4b side of one acute angle corner portion 6 which is mainly involved in cutting. 3a and 3a are arranged so as to be symmetrical with respect to the bisector of the chip body 1 in the vertical direction. Therefore, by providing the first flank 3a having a large clearance angle α1 on the main cutting edge (lateral cutting edge) 4a side, it is possible to avoid interference with the work material at the time of cutting in outer diameter copying or the like. In addition, since the first clearance angle 3a having a large clearance angle α1 is also provided on the side of the secondary cutting edge (front cutting edge) 4b, interference with the work material in internal diameter processing, internal diameter biting processing, etc. Can be avoided.

Further, only the first flank 3a formed within a range that is less than half of the length B of the chip body 1 is set to a large clearance angle α1 of 11 °, and is within a range that covers more than half of the length B of the chip body 1. Since the formed second flank 3b has a flank angle α2 of 5 ° smaller than that, it is compared with the seating surface 12 of the conventional slow way tip 10 in which the flank angle of the entire flank 11 is 11 ° (see FIG. 4 (c)), and the area of the seating surface 5 which is a contact surface with the tool holder is large (see FIG. 2 (b)). Therefore, a stable restraining force on the tool body can be obtained, and the mounting rigidity is excellent.
Further, the blade angle β2 formed by the second flank 3b and the rake face 2 formed in a range extending over half the length B of the chip body 1 is the blade formed by the first flank 3a and the rake face 2. Since it is larger than the angle β1, the strength is high and the tip rigidity is excellent as compared with the conventional slow way tip 10 in which the clearance angle of the entire flank 11 is 11 °.
Therefore, cutting performance can be maintained even when normal outer diameter machining and end face machining are performed, and various turning operations can be handled.

Moreover, the cross ridgeline part of the 1st flank 3a and the rake face 2, the cross ridgeline part of the 3rd flank 3c and the rake face 2, and the cross ridgeline of the 2nd flank 3b and the rake face 2 Since the portions are on the same straight line when viewed from above and form the same cutting edge, the performance of the cutting edge 4 is a throw-away tip 10 with a normal cutting edge angle ε standardized in JIS of 35 °. (See FIG. 2 (a) and FIG. 4 (b)).
Except for a limited range in which the first flank 3a and the third flank 3c are formed, most of them are diamond-shaped with a blade edge angle ε standardized in JIS of 35 ° and a clearance angle of 5 °. Since it has the same shape as the throw-away tip 10, it is not necessary to prepare a dedicated bit holder for attaching the throw-away tip according to this embodiment. Instead, it is attached to a normal bit holder standardized by JIS. Can be used.
Therefore, there is no complicated work such as correction of the cutting edge position, change of the machining procedure and tool path, and reconstruction of a program such as an NC lathe, and the compatibility with the conventional throw-away tip 10 is extremely excellent.

Further, between the first flank 3a and the second flank 3b having different flank angles α, a first flank α1 and α2 are connected by continuously changing the flank angle α with a predetermined width W. Since the three flank surfaces 3 c are formed, the flank angle α does not change abruptly on the one flank surface 3. As a result, stress concentration at the time of cutting in the portion where the clearance angle α between the first flank 3a and the second flank 3b changes is reduced, so that the tip rigidity can be maintained.
On the other hand, if the third flank 3c is not provided, the first flank 3a and the second flank 3b, which are different by 6 ° in the flank angle α, are directly adjacent to each other, so that the shape suddenly changes. A part will occur. Therefore, there is a possibility that stress at the time of cutting concentrates on a portion where the clearance angle α changes suddenly and induces chipping of the chip.

  In addition, since the chip breaker 8 is provided on the rake face 2, the direction of chip outflow caused by cutting is controlled in a constant direction, and the finished surface is not damaged by the collision of the chip. Finished surface finish can be finished.

In the present embodiment, the cutting edge angle ε is set to 35 °, but the cutting edge angle ε is not limited to this and may be an arbitrary cutting edge angle ε.
This cutting edge angle ε is preferably set in the range of 20 ° to 60 ° in the present invention. In particular, when applied to a throw-away tip with a small cutting edge angle ε, the seating surface 12 is reduced when the entire flank 11 is uniformly given a positive flank angle α (see FIG. 4C). This is because the processing accuracy and chip rigidity can be improved.
For example, the edge angle ε may be 55 ° instead of 35 °. When the cutting edge angle ε is 55 °, there is compatibility with a throw-away tip standardized by JIS, and the same effect as in the present embodiment is achieved. Further, the edge angle ε may be 25 ° outside the JIS standard. When the cutting edge angle ε is set to 25 °, it is possible to perform copying along the product shape while avoiding interference with the work material even when the restrictions during machining are even greater.

In the present embodiment, the clearance angle α1 of the first clearance surface 3a is set to 11 °. However, the clearance angle α1 of the first clearance surface 3a is not limited to this, and any clearance angle may be used. It can be α1.
The clearance angle α1 of the first flank 3a preferably satisfies the following relational expression (1).
0 ° <α1 ≦ 17 ° (1)
This is because if the clearance angle α1 of the first flank 3a exceeds 17 °, the blade angle β in the vicinity of the acute corner portion 6 decreases, the strength decreases, and chipping may occur with cutting. .
For example, the clearance angle α1 of the first flank 3a may be 15 ° instead of 11 °. When the clearance angle α1 of the first flank 3a is 15 °, interference with the work material can be avoided in a wider range, and the processing area is expanded. Further, the clearance angle α1 of the first flank 3a can be set to 5 ° or 7 °.

In the present embodiment, the clearance angle α2 of the second flank 3b is 5 °, but the clearance angle α2 of the second flank 3b is not limited to this, and an arbitrary clearance angle It can be α2.
The clearance angle α2 of the second flank 3b preferably satisfies the following relational expression (2).
0 ° ≦ α2 ≦ 11 ° (2)
If the clearance angle α2 of the second flank 3b exceeds 11 °, the thickness of the chip body 1 is sufficient to form the seating surface 5 having a sufficient area to ensure a stable restraining force on the tool body. This is because there is a possibility that the chip rigidity is inferior.
For example, the clearance angle α2 of the second flank 3b can be set to 0 ° instead of 5 °, and the basic shape thereof can be a negative chip. When the clearance angle α2 of the second flank 3b is 0 °, the area of the seating surface 5 does not change even if the thickness of the chip body 1 is increased. It can also be used for heavy cutting with a large feed amount. Further, the clearance angle α2 of the second flank 3b may be 7 °. When the clearance angle α2 of the second flank 3b is 7 °, there is compatibility with a throwaway tip standardized by JIS, and the same effects as in the present embodiment are achieved.

In the present embodiment, the range L1 in which the first flank 3a is formed is 4.0 mm, which is less than half the length B of the chip body 1, but the first flank 3a is formed. The range L1 is not limited to this, and can be arbitrarily set.
The range L1 where the first flank 3a is formed preferably satisfies the following relational expression (3).
L1 + W ≦ B / 2 (3)
If the first clearance surface 3a having a large clearance angle α is formed in a range extending almost half of the length B of the chip body 1, the area of the seating surface 5 is reduced, and the mounting rigidity and the chip rigidity may be reduced. It is.

In the present embodiment, the range L2 in which the second flank 3b is formed is 12.6 mm, which is half or more of the length B of the chip body 1, but the second flank 3b is formed. The range L2 is not limited to this, and can be arbitrarily set.
The range L2 in which the second flank 3b is formed is preferably at least half of the length B of the chip body 1. If the range where the second flank 3b having a smaller flank angle α than the first flank 3a is less than half of the length B of the chip body 1, the area of the seating surface 5 is reduced, This is because the attachment rigidity and the chip rigidity may be reduced.

In the present embodiment, the width W of the third flank 3c is 0.5 mm. However, the width W of the third flank 3c is not particularly limited, and is arbitrarily set. Can do.
The width W of the third flank 3c preferably satisfies the following relational expression (4).
0mm <W ≦ B / 2-L1mm (4)

In the present embodiment, the first flank surfaces 3a and 3a are provided symmetrically on the main cutting edge 4a side and the sub cutting edge 4b side, but the present invention is not limited to this. For example, the first flank 3a may be provided only on the main cutting edge 4a side.
In the present embodiment, the third flank 3c is connected from one plane that linearly connects the first flank 3a to the second flank 3b while continuously changing the flank angle α. However, the shape of the third flank 3c is not limited to this, and can be any shape. For example, an arc-shaped portion may be provided in order to make the joint between the first and second flank surfaces 3a and 3b smooth, or a plurality of planes may be used.

  Further, in the present embodiment, the chip breaker 8 is provided on the rake face 2 for the purpose of improving chip disposal, but the chip breaker 8 may be omitted instead. Further, the configuration of the chip breaker 8, the shape of the breaker groove 8a, and the shape of the breaker protrusion 8b are not particularly limited, and can be arbitrarily set.

  In the present embodiment, the clamp holder standardized in JIS has been described as an example of the tool holder to which the slow way tip is attached. However, the tool holder is not limited to this, and is matched to the shape of the product. Arbitrary tool holders can be applied, and other turning tools such as boring tools and boring tools can also be applied.

It is a perspective view which shows the throw away tip which concerns on one Embodiment of this invention. It is a figure which shows the throw away tip of FIG. 1, (a) is a top view, (b) is a bottom view, (c) is a front view. It is a schematic diagram which shows the XX line cross section and YY line cross section of FIG. 1 and FIG.2 (b). It is a figure which shows the conventional throwaway tip, (a) is a perspective view, (b) is a top view, (c) is a bottom view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tip main body 2 Rake face 3 Flank 3a 1st flank 3b 2nd flank 3c 3rd flank 4 Cutting edge 5 Seating surface 6 Sharp corner part 7 Obtuse corner part alpha1 Flank angle of 1st flank α2 Clearance angle ε of second flank face Edge angle B Tip body length L1 Range where the first flank face is formed W Width of third flank face

Claims (6)

A substantially rhombic plate-shaped chip body, a rake face provided on an upper surface of the chip body that forms a substantially rhombus, a flank face provided on each side surface of the chip body intersecting the rake face, and the rake face, A throw-away tip comprising a cutting edge provided at a ridge line intersecting with the flank,
At least one flank of the plurality of flank surfaces is a first flank surface provided in the vicinity of the acute corner portion of the chip body, and closer to the obtuse corner portion side of the chip body than the first flank surface A second flank provided, and a third flank provided between the first flank and the second flank;
A clearance angle of the first flank is larger than a clearance angle of the second flank; and
The throw-away tip, wherein the intersecting ridge line portion between the first, second and third flank surfaces and the rake surface is on the same straight line when viewed from above and forms the same cutting edge. 2. The throwaway tip according to claim 1, wherein a cutting edge angle formed by a pair of cutting blades facing each other with the acute corner portion interposed therebetween is 20 ° or more and 60 ° or less. The throw-away tip according to claim 1 or 2, wherein the following relational expression (1) is satisfied.
0 ° <α1 ≦ 17 ° (1)
Here, α1 is the clearance angle of the first flank. The throw-away tip according to claim 3, wherein the following relational expression (2) is satisfied.
0 ° ≦ α2 ≦ 11 ° (2)
Here, α2 is a clearance angle of the second flank. The throw-away tip according to any one of claims 1 to 4, wherein the following relational expression (3) is satisfied.
L1 + W ≦ B / 2 (3)
Here, B is from the intersection (O) on the extension line of the two sides facing each other across the acute corner portion on the rake face to the intersection (P) on the extension line of the two sides facing each other across the obtuse corner portion. , L1 is the distance from the intersection (O) to the rear end of the first flank adjacent to the third flank on the cutting edge, and W is the first flank on the cutting edge. The distance from the front end of the third flank adjacent to the surface to the rear end of the third flank adjacent to the second flank. The throw-away tip according to claim 5, wherein the following relational expression (4) is satisfied.
0mm <W ≦ B / 2-L1mm (4)

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