JPH0524118U - Punch for press working - Google Patents

Abstract

(57) [Abstract] [Purpose] In the drilling process, when drilling a narrow material that is relatively hard and has a plate thickness, the center of the hole can be easily and accurately positioned, the hole wall surface is good, and the punch is used. It is an object of the present invention to provide a punch having a long life. [Structure] A feature of the present invention is that it comprises a blade portion, a guide portion, and a fixed portion in the axial direction, and the blade portion of the punch has an end face perpendicular to the shaft portion, and the outer peripheral edge portion of the end face is A hole having a diameter slightly smaller than the diameter of the hole to be drilled and provided with an appropriate inclination, and further having an inclination angle larger than the diameter of the apex in the axial direction from the apex. A drilling barrel is provided, and the rear end of the drilling barrel is connected to the axial guide portion, and the guide portion extends toward the rear portion of the shaft from the maximum diameter portion of the drilling barrel. A large-diameter tilt angle is formed so as to be connected or connected to the fixed portion, and a hollow portion that opens at the rear end of the fixed portion is cut out in the body core of the guide portion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a punch for press working used in press punching and extrusion, and particularly to a punching allowable thickness of steel material and forging material having a width three times as wide as the punching hole and a carbon content of 40% or more. The present invention relates to a punch structure suitable for pressing a large work piece.

[0002]

[Prior Art]

 Conventionally, in continuous work such as punching and extruding a work material by a metal plastic working machine, a punch is used to apply impact and pressure to the work material to plastically work the work material into a desired shape. Generally, a punch having a maximum outer diameter with one or two relatively small inclination angles is formed on the end face of the punch blade, and an axial relief is provided on the back surface of the top. Proposals are known in which a fixed part is connected to a fixed part via a guide part. (Japanese Patent Publication No. 53-8388)

However, these proposals are limited to the case of a material whose plate thickness is relatively smaller than the diameter of the punch, and in the case of a material having a plate thickness and a relatively high hardness, the friction loss is large and the secondary loss is large. There were many fractures and fractured surfaces, the punched surface was rough, and there were many burrs, and the punches were seized, buckled, and damaged, which shortened the punch life and therefore had a problem in productivity. ..

[0004]

[Problems to be solved by the present invention]

 The object of the present invention is to overcome the problems inherent in the above-mentioned known techniques, and at the same time, even when punching a relatively hard narrow material having a plate thickness, the positioning of the hole center is It is an object of the present invention to provide a punch which is easy, has a small fracture surface ratio with respect to the mirror surface, has little burr and burr, and can prolong the life of the punch.

[0005]

[Means for Solving the Problems] A feature of the present invention is that it comprises a blade portion, a guide portion, and a fixed portion in the axial direction, and the blade portion of the punch has a vertical end face on the shaft portion, and The outer peripheral edge of the end face has a diameter slightly smaller than the diameter of the hole to be bored, has an apex with an appropriate inclination, and has a diameter larger than the diameter of the apex in the axial direction from the apex. And a rear end of the perforating body is connected to the axial guide part, and the guide part is directed toward the rear part of the shaft, and A cavity that is connected to or fixed to the fixed part with an inclination angle larger than the maximum diameter part of the opening body part, and that is opened at the rear end of the fixed part in the center part of the body part of the guide part. The part is cut out to configure.

[0006]

[Action]

 The punch blade has a vertical end face on the shaft, and the outer peripheral edge of the end face is smaller than the hole diameter of the hole to be drilled, and has a top with an appropriate inclination. Since the drilling body is formed axially from the top and has an inclination angle larger than the diameter of the top, the punch end face having a diameter smaller than the diameter of the hole is used in the drilling process. At that time, the initial impact force is applied to start shearing for drilling, and the drilling body part (having an inclination angle) is displaced behind the end face, so that the drilling body part is disconnected. The punch moves forward while expanding the hole wall of the started hole (smaller than the hole diameter of the hole to be drilled), and due to the small friction when the hole wall is expanded, the hole wall is guided. When the wall of the hole is expanded to the hole diameter that the hole body should be drilled, Advancement of the punch is stopped, the punching scrap is separated. Therefore, a good hole wall surface and shear cut surface can be obtained.

[0007] Furthermore, by providing the hollow portion that opens at the rear end portion of the fixed portion in the core portion of the guide portion, it is possible to increase the toughness of the punch and prevent heat accumulation in the portion, so that the blade portion is seized. And has the effect of extending the life of the punch.

[0008]

Embodiment 1 A preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 2 to 5, the punch (1) according to the present invention is made of steel or cemented carbide and has a blade portion (2), a guide portion (3) and a fixing portion (4) in the axial direction. The blade portion (2) has an end face (6) perpendicular to the shaft (5), and at the center of the end face (6), approximately 1 / radius of the end face (6) is included. A conical protrusion (7) with two radii and an appropriate height is provided, and the outer peripheral edge of the end face (6) has a diameter smaller than the diameter of the hole (8) to be drilled. (9) is formed, and further, a perforated body (( ₁ ) is formed which has an inclination angle (θ ₁ ) larger than the diameter of the apex (9) in the axial direction from the apex (9). 10) is provided, and the inclination angle is (1 to 5 °). ) The drilling body (10) is connected to the axial guide part (3) so that the guide part (3) extends rearward of the guide part from the connecting part of the drilling body (10). A large-diameter inclination angle (θ ₂ ) is formed to be connected or fixed to the fixed portion (4), and the rear end of the fixed portion (4) is attached to the body core of the guide portion (3). The cavity (11) communicating with the opening is cut out to improve the toughness and strength of the punch (1) through the cavity (11), and at the same time, to prevent heat accumulation in the punch body and to cut the blade. It is designed to prevent seizure of the part and contribute to the improvement of punch life.

[0009]

Embodiment 2 In the formation of the blade portion (2), as another embodiment, as shown in FIG. 6, a vertical end face (6) is formed along the outer edge of the top portion (9) of the blade portion (2). The outer edge of the blade has a tilt angle (θ ₃ ) of 15 to ₃₀ °, which is used to disperse the stress of the initial impact force at the end of the blade (2) and at the time of initial drilling, It is also possible to maintain the degree of stability, improve its stability, and perform drilling work. In this case, the protrusion (7) at the center of the end face (6) of the blade (2) may have an inclination angle (θ ₄ ) of 80 to 90 ° with respect to the end face (6). desirable.

[0010]

[Third Embodiment] In the above-mentioned configuration of the blade portion (2), in addition to the well-known quenching and annealing processes, the end face (6) portion (including the protrusion portion (7)) that is the initial action surface of the blade portion (2) Except for the above, the outer periphery of the drilling body (10) of the blade (2) should be covered with one or more of titanium carbide, nitride or carbonitride, and aluminum oxide. You can (However, illustration is omitted.)

[0011]

[Effect of the device]

 Since the device of the present application has the above configuration, it has the following effects. The punch blade has a top portion having a diameter smaller than the diameter of the hole to be bored, and a punching hole having an inclination angle larger than the diameter of the top portion in the axial direction from the top portion. Since the punch has a body, when the punch is lowered by pressing force and comes into contact with the surface of the workpiece during drilling, the compressive stress and tensile stress due to the end face of the punch blade reaches a limit. The punch moves forward while the cracks generated at the edge are pushed and spread by the top of the blade and the body of the hole, and the shearing process of the hole is completed. Cracks generated on the punch side and the die side during the shearing process are good, smooth shearing is performed, and a good shear cut can be obtained. Therefore, conventional drilling can be used instead.

Further, since the conical projection is formed at the center of the end face of the blade, the hole of the workpiece can be smoothly positioned. Therefore, it is possible to smoothly perform the drilling of relatively thick work material.

Next, the punching body of the punch blade has a conical shape with a diameter larger in the axial direction than the top of the blade, and the guide portion extending to the punching body is It is known in the art that it has a large angle of inclination toward the shaft and a notch is formed in the central core of the guide part that opens at the rear end of the fixed part that is connected to the guide part. Unlike the empty body of the punch, even if the punch is subjected to heat treatment, the load temperature at that time is uniform in the present invention, and it is possible to obtain a uniform and uniform metallographic structure. It is less likely to remain as crystal strain, and the toughness of the punch itself is improved and its strength is increased, so that damage such as cutting and cracking can be prevented.

In the punch according to the second aspect, since the inclination angle of 15 to 30 ° is given to the outer contour of the vertical end surface of the blade along the outer edge of the top of the blade, the compressive stress to the top of the blade is increased. It is possible to reduce the concentration of steel, increase the component force acting at right angles to shear, and maintain the verticality of the punch at the time of initial drilling to improve its stability, reducing wear loss during machining. It is possible to prevent burning and seizure. Therefore, the drilling of a relatively large thick plate becomes smooth.

In the punch of the third aspect, since the punching barrel is provided with a tilt angle of 1 to 5 ° from the top of the blade in the axial direction, the amount of acting perpendicular to the shear is obtained. The force is increased, the concentration of compressive stress on the top of the blade is relieved, an appropriate expansion action of the hole is created, the punch side crack and the die side crack meet well, and the blade wear loss is reduced. cut back. The angle of inclination given to the hole-dwelling body was 1 to 5 ° and was limited to 5 ° or less. When the angle of inclination is 5 ° or more, the expandability of the hole increases, but the friction against the punch is increased. This is because the resistance increases, the stress concentration also increases, and it is necessary to increase the pressure applied to the punch, which may adversely affect the drilling process.

In the punch according to claim 4, heat resistance and oxidation resistance of the punch are obtained by covering the punching body of the blade portion, excluding the end face portion (including the protrusion) of the blade portion, with a hard material. The wear resistance, wear resistance, and corrosion resistance can be improved. Therefore, seizure can be prevented, the strength can be increased, and the risk of cracks, cuts, etc. can be reduced.

[Brief description of drawings]

FIG. 1 is a side view showing a shape of a blade of a conventional punch for press working.

FIG. 2 is a side view showing a shape of a blade portion of a punch for press working according to an embodiment of the present invention.

FIG. 3 is a plan view of the punch of FIG.

FIG. 4 is an enlarged side view of an essential part showing the shape of the blade of the punch of FIG.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is an enlarged sectional view of an essential part showing the shape of a blade according to the second embodiment of the present invention.

FIG. 7.

FIG. 8 is an explanatory view showing a punched state of a punch according to the present invention.

[Explanation of symbols]

(1): Punch (2): Blade (3): Guide
(4): Fixed part (5): Shaft (6): End face (7): Projection (8): Hole
(9): Top part (10): Bore body (11): Cavity part (θ ₁ ): Inclination angle (θ ₂ ): Inclination angle (θ ₃ ): Inclination angle

Claims (4)

[Scope of utility model registration request] 1. A punch for press working, which comprises a blade portion, a guide portion, and a fixed portion in the axial direction, wherein the blade portion of the punch has an end face perpendicular to the shaft, and a conical projection at the center of the end face portion. And an outer peripheral edge portion of the end face portion has a diameter slightly smaller than the hole diameter of the hole portion to be bored to form an appropriately inclined top portion, and an axial direction from the top portion , Having a perforating body portion having an inclination angle larger than the diameter of the top portion, and connecting the perforating body portion to a guide portion, the guide portion being a continuous portion of the perforating body portion. A hollow portion that is open to the rear end of the fixed portion is formed in the body core of the guide portion by forming a large inclination angle toward the rear part of the guide portion and connecting to the fixed portion. A punch for press processing that is characterized. 2. The punch for press working according to claim 1, wherein an inclination angle of 15 to 30 ° is given to the outer contour of the vertical end surface of the blade portion along the outer edge of the top portion of the blade portion. 3. The punch for press working according to claim 1 or 2, wherein a punching body portion is formed with an inclination angle of 1 to 5 ° from the top of the blade portion in the axial direction. 4. A carbide or nitride of titanium or a carbonitride of aluminum and an oxide of aluminum is formed on the outer periphery of the body of the drilling body of the blade, excluding the end face portion (including the protrusion) which is the initial action surface of the blade portion. The punch for press working according to claim 1 or 3, which is covered with one or more kinds.