JP3393090B2 - Tool - Google Patents

Description

Detailed Description of the Invention

[0001]

2. Description of the Related Art Tools such as punches (B1), (B2), and (B3) have a cutting edge at the tip of a support member (40) made of steel as shown in FIG. 5, 6 or 7. The blade member (41) is used by brazing. As the brazing method, the supporting member (40) and the blade member (41) are butted to each other for brazing metal.
When brazing with (44) (see Fig. 5), a mortar-shaped mounting hole (42) is bored at the tip of the support member (40) and a truncated cone shape is formed on the mounting side of the blade member (41). Insert the formed mounting protrusion (43),
A method of pouring brazing metal (44) into the insertion part to fix it (see Fig. 6), or a mounting hole (45) at the tip of the support member (40)
A method of inserting the brazing metal (44) into the insertion portion and inserting the brazing metal (44) into the insertion portion and inserting the brazing metal (44) to the blade member (41) Was adopted.

In the case of brazing of ordinary machine parts, the above brazing method is sufficient, but in the case of tools (B1) to (B3) such as punches, it is very large when cutting or punching a metal plate material. Impact compression load is applied to tools (B1) to (B3). After cutting, when the tools (B1) to (B3) are pulled out from the punching hole of the metal plate material, the inner peripheral surface of the punching hole and the tool (B1) to
A large frictional force in the pull-out direction is generated between the outer peripheral surface of (B3).

Of course, the impact pressure at the time of punching is also directly applied to the brazed portion (44), and the brazed portion (44)
Gradually get tired. Brazing part (44) which is inferior in mechanical strength to the steel support member (40) and the blade member (41).
First, a crack is generated, and the crack gradually grows due to the impact pressure and the frictional force in the pulling direction repeatedly applied, and the brazed portion (44) is fractured.

Brazing is carried out by using a supporting member (40) and a super hard member (4).
1) and are heated to the brazing temperature, the brazing metal (44) having a low melting point is poured into the gap between the mounting hole (42) and the mounting protrusion (43), and then the heated portion is heated. Cool and fix the mounting point (43) to the mounting hole (42) with brazing metal (44).

At this time, the steel support member (4
(0) and the blade member (41) whose coefficient of thermal expansion is almost half that of the steel support member (40), there is a difference in contraction, and this is all accumulated in the brazing part (44). Brazing part (44)
A large amount of stress may remain, and in extreme cases, hair cracks may occur. Although the residual stress is relieved considerably by heat treatment, the hair crack is not eliminated and gradually grows during use of the tools (B1) to (B3), and finally the brazed portion (44) is torn.

When the cracks in the brazed portion (44) grow to such an extent that the cutting operation can no longer be tolerated, the blade member (41) is detached from the supporting member (40) by a punching hole in the metal plate material. It occurs when the tools (B1) to (B3) are pulled out from.

[0007]

The present invention not only can reduce the possibility of breakage from the brazed portion, but even if the breakage suddenly occurs in the brazed portion during use, it is possible to prevent the breakage from the support member. It is to develop a tool that does not cause the hard member to fall off.

[0008]

[Means for Solving the Problems] [Claim 1] refers to the first embodiment (see FIG. 1) of the present invention, in which the blade member is attached to the mounting hole (2) formed at the tip of the supporting member (1). In the tool (A1) in which the blade member (3) is attached to the tip of the support member (1) by brazing the attachment protrusion (4) of (3), the opening (7) of the attachment hole (2) )
The inner part (8) of the mounting hole (2) is formed wider than the narrowest part (6) of the, and the mounting hole (2) of the mounting protrusion (4) of the blade member (3) is formed.
The innermost part (8) of the mounting hole (2) is fitted with the innermost part (8) of the mounting part (8), and a part of the side surface of the mounting part (9) is expanded.
It is formed to have almost the same dimensions as (6). "

As a result, the mounting projection (4) of the blade member (3) is inserted into the mounting hole (2) of the support member (1) with a slight press fit, and then this portion is heated before the mounting hole (2). The brazing metal (12) is poured into the gap between the mounting protrusion (4) and the mounting protrusion (4) to fix them. (Of course, in the above case, the heating may be performed prior to the insertion.) In this state, the width including the brazing metal (12) is reduced by the brazing metal (12) attached to the mounting projection (4). Naturally, the width becomes larger than the width of the narrowest part (6) of the mounting hole (2), and a so-called "fitting and killing" state is achieved.

Therefore, even if the brazing metal (1
Even if any part of 2) is broken or the brazing metal (12) is separated from the surface of the mounting projection (4) or the surface of the mounting hole (2), the brazing metal (12) does not disappear. Mounting protrusion
It is impossible for the large diameter tip (9) of (4) to pass through the narrowest part (6) of the mounting hole (2), and therefore the brazing metal (12) may break during the cutting operation. The blade member (3) will not fall off from the support member (1) even if the occurrence occurs.

In the present invention, the tip portion of the blade member (3)
It was specified that the widest part (10) of (9) was formed to have almost the same size as the narrowest part (6) of the mounting hole (2), but the meaning of "approximately the same size" is "zero." Of course, "fitting" includes "press-fitting" and "free fitting". In the case of "free fitting", the maximum is "dimension of narrowest part (6)" = "widest part (10)" + ("Thickness of brazing metal (12)" or "the narrowest part (6) and the widest part (10)"
Gap ").

"Claim 2" is characterized in that "the coefficient of thermal expansion of the support member (1) is larger than that of the blade member (3)" with respect to the expansion coefficient and toughness of both. In case of shrinkage after brazing, the shrinkage of the inner diameter of the mounting hole (2)
Since the contraction rate of (4) is exceeded, the entire mounting hole (2)
(4) The whole body is tightened from the entire circumference, and the compression pressure is constantly applied to the brazing metal (12) in the meantime. As a result, even if a hair crack occurs in any part of the brazing metal (12), the growth is hindered, and the effect of extending the life of the tool is produced.

The "claim 3" is the reverse of the claim 1, "the mounting projection (22) formed at the tip of the support member (21) is provided on the blade member (23).
A tool in which the blade member (23) is attached to the tip of the support member (21) by brazing to the mounting hole (24) formed in the mounting surface of the
In (A2), the narrowest part of the opening (27) of the mounting hole (24)
The inner part (28) of the mounting hole (24) is formed wider than the (26) and fits into the inner part (28) of the mounting hole (24) of the mounting projection (22) of the support member (21). The widest part (30) of the tip part (29) in which a part of its side surface is bulged is the narrowest part (2) of the mounting hole (24).
It is formed to have almost the same dimensions as 6). "

In this case as well, after brazing as described above, the mounting projection (22) is mounted in the mounting hole (24) in a "fitting and killing" state, so that the blade member (23) in use falls off. Is eliminated. However, in this case, the mounting protrusion (22) of the support member ( 21 ) having a large expansion coefficient is
Since it will be inserted into the mounting hole (24) of 3), the "tightening effect" by cooling after brazing cannot be expected.

"Claim 4" defines the material of the blade member (3) (23) and is characterized in that "the blade member (3) (23) is cemented carbide, high speed steel or die steel". . High speed steel stands for high speed steel.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the illustrated embodiments. 1 and 2 relate to Example 1 (A1), in which a "punch" is taken up as a representative example of the tool (A). Of course, it is not limited to "punch", but can be applied to cutting tools, drills, shearing blades, and the like. The tool (A1) of Example 1 is composed of a support member (1) and a blade member (3). The support member (1) is provided with a mounting hole (2) at its tip, and the mounting projection (4) of the blade member (3) is brazed. The support member (1) is made of a material having a higher toughness than the blade member (3) .For example, in the case where the blade member (3) is made of carbide, the hardness and the toughness are lower and the toughness is higher. When steel or the like is used and the blade member (3) is high-speed steel or die steel, high-strength steel material such as nickel / chromium / molybdenum steel having lower hardness and higher toughness is used.

In the mounting hole (2), a part of the inner surface of the opening (7) bulges inward, and this part becomes the narrowest part (6). Therefore, the inner part (8) of the mounting hole (2) is formed wider than the narrowest part (6). Peripheral part of the hole that constitutes the mounting hole (2)
The inner peripheral surface (11b) of (11) draws a gentle arc from the narrowest part (6) toward the hole edge (11a) of the opening (7) of the mounting hole (2), and gradually its meat It is formed to reduce the thickness.

When the blade member (3) is carbide, WC or T
The main component is iC or a mixture thereof, and this is hardened with a binder such as cobalt or nickel.
In some cases, nitriding treatment is performed and the surface may be nitrided. As another example, high-speed steel or die steel is also used as the blade member (3) as described above.
The cutting edge portion (3a) at the tip is formed in accordance with a shape to be cut, cut or punched, and is formed in an appropriate shape such as a circle or a corner.

A mounting projection (4) is provided on the mounting surface of the blade member (3). The shape of the mounting protrusion (4) is similar to the shape of the mounting hole (2), and a part of the side surface of the tip portion (9) bulges out, and this portion becomes the widest portion (10). .

The relationship between the widest portion (10) and the narrowest portion (6) is that they are "substantially the same size." Therefore, not only "zero fitting" but also "press fitting" and "free fitting" are possible. Including. Maximum in case of "play fit", "dimension of narrowest part (6)" = "widest part (10)" +
("Thickness of brazing metal (12)" or "gap between narrowest part (6) and widest part (10)").

The mounting protrusion (4) of the blade member (3) is inserted into the mounting hole (2) of the support member (1) formed as described above, and the brazing metal is heated by heating the insertion portion as a center. Pour (12) into the gap between both (2) and (4). The brazing metal (12) instantly fills the gap by capillary action and bonds the two (2) and (4) together.

When the brazing is completed, the support member (1) is cooled, but at this time the coefficient of thermal expansion of the support member (1) is larger than that of the blade member (3). ) Inner diameter shrinkage rate exceeds the mounting projection (4) shrinkage rate, the entire mounting hole (2) tightens the entire mounting projection (4), and the brazing metal (12) fills the gap at all times. Compressive pressure is applied. This has the effect of preventing the growth of hair cracks in any part of the brazing metal (12) and prolonging the life of the tool.

The tool (A1) thus formed is mounted on a machine tool such as a punching machine to perform punching work or cutting / cutting work of a metal plate material. A large impact load is applied to the tool (A1) every time. This impact load naturally also acts on the brazing part (12), and hair cracks often occur at the brazing part (12), which is the most inferior in strength. Hair cracks can occur in any part.The middle part of the brazing metal (12), the brazing metal (12) and the mounting protrusion (4) or the mounting hole (2). Occurs on the adhesive surface of.

If the hair cracks are not noticed and are used continuously, the hair cracks gradually grow and eventually break. In the conventional example, when such a situation is reached, the blade member (3) is instantly dropped from the support member (1), which causes an accident such as mold damage, but in the case of the present invention, a gap is created. The brazing metal (12) that has been embedded becomes a "wedge" and becomes a "fitting and killing state", and the blade member (3) does not fall off from the support member (1).

Next, a second embodiment will be described. In this case, as shown in FIGS. 3 and 4, the positional relationship between the mounting holes and the mounting projections is reversed, and the others are the same as in the first embodiment, and therefore the description thereof is omitted for the sake of simplicity. In this case as well, after brazing, the mounting projection (22) is mounted in the mounting hole (24) in a "fitting and killing" state, so the accidental fall of the blade member (23) in use is the same as in Example 1. It is also resolved. However, in this case, the mounting protrusions (22) of the support member ( 21 ) with a large expansion coefficient will be inserted into the mounting holes (24) of the blade member (23) with a small expansion coefficient, so after brazing The difference is that the "tightening effect" due to cooling cannot be expected.

[0026]

Since the present invention has the above-described structure, when the brazing is performed, the width of the brazing metal adhered to the mounting protrusions is smaller than the width of the narrowest portion of the mounting hole. Naturally, it grows into a so-called "fit and kill" state,
Not only can the possibility of breakage from the brazed portion be reduced, but even if a sudden break occurs in the brazed portion during use, the blade member will not fall off the support member.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a tool of embodiment 1 according to the present invention.

FIG. 2 is an exploded sectional view of FIG.

FIG. 3 is a sectional view of a tool of embodiment 2 according to the present invention.

FIG. 4 is an exploded sectional view of FIG.

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

FIG. 6 is a sectional view of another conventional example.

FIG. 7 is a sectional view of still another conventional example.

[Explanation of symbols]

(A) (A1) (A2) Tool (1) Support member (2) Mounting hole (3) Blade material (4) Mounting protrusion (6) narrowest part (7) Opening (8) Back (9) Tip (10) Widest part

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI B23K 1/00 330 B23K 1/00 330B (58) Fields investigated (Int.Cl. ⁷ , DB name) B21D 37/20 B21D 28 / 14 B21D 28/34 B21D 37/01 B23K 1/00

Claims (4)

(57) [Claims] 1. A tool in which a blade member is attached to the tip of a supporting member by brazing a mounting protrusion of the blade member to a mounting hole formed in the tip of the supporting member, The inner part of the mounting hole is formed wider than the narrowest part, and it fits into the inner part of the mounting hole of the mounting protrusion of the blade member ,
The widest part of the tip part of which part of the side face of the bulge is formed to have substantially the same size as the narrowest part of the mounting hole. 2. The tool according to claim 1, wherein the support member has a coefficient of thermal expansion higher than that of the blade member. 3. A tool in which a blade member is attached to the tip of a support member by brazing an attachment protrusion formed at the tip of the support member to an attachment hole formed in the attachment surface of the blade member, the attachment comprising: The inner part of the mounting hole is formed wider than the narrowest part of the opening of the hole, and is fitted into the inner part of the mounting hole of the mounting protrusion of the support member ,
The widest part of the tip part of which part of the side face of the bulge is formed to have substantially the same size as the narrowest part of the mounting hole. 4. The tool according to any one of claims 1 to 3, wherein the blade member is cemented carbide, high speed steel or die steel.