PUNCHING UNIT FOR PUNCHING APPARATUS

Abstract: In a punching unit for punching apparatus comprising a support section (1) of a ⊐-letter shape with a material inserting groove (11) formed in the middle, a punch (2) vertically movably and removably mounted in a mounting bore in the side end of the upper half (1a) of the support section (1), a die (3) removably mounted in the side end of the lower half (1b) of the support section (1) and having a die opening formed conforming to the outer periphery of a working surface of the punch (2), and a lifting mechanism (4) removably connected to the die (3), the working surface of the punch (2) is formed in a shape of a concave slot, and a slug discharge bore is provided communicating with the die opening of the die (3) and with the lower half part (1b) of the support section (1).

Description: BACKGROUND OF THE INVENTION : Field of the Invention : The present invention relates to a punching unit for punching apparatus and, more particularly, to improvements in the structure around a punch of the punching unit for a punching apparatus for producing holes in thin materials, such as ceramic green sheets, flexible films, metal films, prepregs, or the like. Description of the Prior Art : A punching unit for punching apparatus has previously been proposed by the applicant of the present invention in JP-A-62-102198. The punching unit for punching apparatus pertaining to the applicant's previous proposition comprises a support section formed in a nearly ⊐-letter shape with an inserting groove provided in the center thereof for setting a material to be punched; a punch vertically movably and removably inserted in a mounting bore formed in the side end of the upper half of the support section; a die removably mounted at the side end of the lower half of the support section, and having a die opening formed conformable to the shape of the outer periphery of a working surface of the punch; and a lifting mechanism movably mounted on the upper half of the support section, and removably connected to the die. According to the present applicant's previous proposition, the punching unit for punching apparatus has such an advantate that various types of holes can readily be produced with the punch replaced with ease only by moving the vertically movable mechanism after disconnecting from the punch. Problem the Present Invention Intends to Solve : The punching unit for the punching apparatus previously proposed by the present applicant is suitable for punching relatively small holes which the punch is required to pierce through, but still has a problem to be solved that the punch unit is not fully applicable to punching relatively large holes which the punch is required to notch. To solve this problem, the present invention has been accomplished, and it is an object of the present invention to provide a punching unit for punching apparatus that enables easy replacement of the punch and also thorough application to the punching of relatively large holes to be produced. Means to Solve the Problems : To accomplish the aforementioned objects, the present invention provides a punching unit for a punching apparatus having a support section formed in a nearly ⊐-lettershape with an inserting groove in the middle section for setting a material therein; a punch vertically movably and removably inserted in a mounting bore provided in the free end of the upper half of said support section; a die mounted on the lower half of said support section and having a die opening conformable to the shape of an outer periphery of the working surface of the punch; and a lifting mechanism movably mounted on said upper half of said support section and removably connected to said punch, characterised in that said working surface of said punch is concave in form, a slug discharge bore connects the die opening of said die with said lower half of said support section and said slug discharge bore (32) has a diameter larger than that of the die opening. Function : The above-mentioned means, utilising the prior-art structure for moving the lifting mechanism pertaining to the previous proposition described above, can fullfil the object to enable easy replacement of the punch. Also, since the material to be punched is notched and punched by the concave section of the working surface of the punch and slugs are discharged downwardly from the die opening, it is possible to accomplish the object to enable the application of the punch unit to the punching of relatively large holes. Other objects and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS : The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein: Fig. 1 is a sectional view showing the state of a punching unit for punching apparatus according to an embodiment of the present invention prior to installation; Fig. 2 is a sectional view showing the state of the punching unit of Fig. 1 after installation; and Fig. 3 is a sectional view taken along line X-X in Fig. 2. DESCRIPTION OF THE PREFERRED EMBODIMENT: Hewreinafter an exemplary embodiment of a punching unit for punching apparatus according to the present invention will be described with reference to the accompanying drawings. In this embodiment, the punching unit is constituted of a support section 1, a punch 2 mounted on this support section 1, a die 3, a lifting mechanism 4, and a connecting member 5 connecting the lifting mechanism 4 to the punch 2. The support section 1 produced of steel plates and other as a forming material having sufficient strength, is provided, for setting a material A, with an inserting groove 11, which is formed at the middle part extending inwardly from one end of the support section 1, so that the general sectional form thereof will be a nearly ⊐-letter shape. This support section 1 is constituted of an upper half 1a and a lower half 1b with the above-mentioned inserting groove 11 formed therebetween. The lower surface 12 of the lower half 1b has a dovetail groove 13 for setting the punching unit on a base plate of the punching apparatus. In the upper surface 14 of the upper half 1a also is provided a dovetail groove 15 for movably mounting the lifting mechanism 4. Furthermore, in one side end of the upper half 1a is formed a mounting bore 16 from the upper surface 14 through to the inserting groove 11, for mounting the punch 2. In the lower half 1b on the downward extension of the axial center line of this mounting bore 16, a step section 17 for mounting the die 3 is provided open to the inserting groove 11. Furthermore, a slug discharge bore 18 is formed through from this step 17 to the lower surface 12 of the lower half 1b. Beneath this slug discharge bore 18 is mounted a slug discharge chute 6. The punch 2 is provided with a shank 21 vertically movably and removably inserted in the above-mentioned mounting bore 16, a working surface 22 of concave form mounted on the lower end of the shank 21, and a cushioning material 23 for covering the outer periphery of the working surface 22. The die 3 has a die opening 31 so formed as to conform the shape of the outer periphery of the working surface 22 of the punch 2, and a slug discharge bore 32 continuing therewith and open to the above-mentioned slug discharge bore 18. This die 3 is fixedly mounted by a bolt 7 to the lower half 1b of the support section 1. The lifting mechanism 4 has a moving section 42 which is provided with a dovetail groove 41 in the lower surface and slides on the upper surface 14 of the upper half 1a of the support section 1, and a piston mechanism 43 supported by the moving section 42. In the above-mentioned dovetail groove 42 is fitted a slider 8 fastened by a locking bolt 44. This slider 8 is also inserted in the dovetail groove 15 provided in the upper half 1a of the support section 1. Turning the locking bolt 44 locks the moving section 42 to, and unlocks it from, the upper half 1a of the support section 1. The piston mechanism 43 has a piston 43b fitted in a cylinder 43a and a shaft 43c fixed in the piston 43b. On the lower end of the shaft 43c is mounted a locking section 43d. For driving this piston mechanism 43, it is possible to select any desired driving power source such as a pneumatic pressure, an oil hydraulic pressure, and electrical excitation. The connecting member 5 includes a bifurcated portion 51 which engages with the above-mentioned locking section 43d and a screwing portion 52 which fits the upper end of the punch 2. Near the aforementioned mounting bore 16 in the upper half 1a of the support section 1 and near the piston mechanism 43 of the moving section 42, stress absorbing sections 19 and 45 are provided, having two pin holes 19a and two pin holes 45a respectively. The pin holes 19a are connected by a curved cut 19b, and the pin holes 45a, by a curved cut 45b, thereby absorbing a stress caused by the application of the punching pressure. According to the above-described embodiment, in the use of the punching unit, the locking bolt 44 is loosened and the moving section 42 is moved toward the opposite side of the mounting bore 16 as shown in Fig. 1. Then, the punch 2 having the working surface 22 of a desired shape is inserted into the mounting bore 16 described above, and the die 3 corresponding to the punch 2 is mounted by the mountingbolt 7 to the step section 17. Subsequently as shown in Fig. 2, the moving section 42 is slid to a position where the locking bolt 44 is tightened; the locking section 43a is locked by the bifurcated part 51 of the connecting member 5; the top end of the punch 2 is securely fastened with the screwing portion 52 by tightening a screw 9, thus connecting the lifting mechanism 4 (piston mechanism 43) and the punch 2. The replacement and maintenance of the punch 2 can very easily be performed by reversing the above-mentioned procedure. After the installation of the punch 2 and other parts as described above, the material A is set in position. As the piston mechanism 43 is driven, the punch 2 goes downwardly, producing a hole by notching the material A between the punch 2 and the die 3. A slug B is discharged from the slug discharge openings 32 and 18 and through the slug discharge chute 6. Effect of the Invention : The punching unit for punching apparatus according to the present invention, as described above, has such an effect as easy replacement and maintenance of the punch because of the utilization of the lifting mechanism operating mechanism of prior art. Furthermore, because the material is punched with the concave section of the working surface of the punch and a slug thus produced is ejected downwardly from the slug discharge bore, the punching unit is fully applicable to producing relatively large holes.

Claims: A punching unit for a punching apparatus having a support section (1) formed in a nearly ⊐-lettershape with an inserting groove (11) in the middle section for setting a material (A) therein; a punch (2) vertically movably and removably inserted in a mounting bore (16) provided in the free end of the upper half (1a) of said support section; a die (3) mounted on the lower half (1b) of said support section (1) and having a die opening (31) conformable to the shape of an outer periphery of the working surface of the punch (2); and a lifting mechanism (4) movably mounted on said upper half (1a) of said support section (1) and removably connected to said punch (2), characterised in that said working surface of said punch (2) is concave in form, a slug discharge bore (32) connects the die opening (31) of said die with said lower half (1b) of said support section (1) and said slug discharge bore (32) has a diameter larger than that of the die opening. A punching unit for punching apparatus as claimed in claim 1, characterised in that said punch (2) comprises a shank (21) inserted in said mounting bore (16) formed in said support section (1a) and a working surface (31) formed concave which is mounted on the bottom end of said shank (21). A punching unit for punching apparatus as claimed in claim 2, characterised in that the outer periphery of said working surface (31) of said punch (2) is covered with a resilient cushioning material (23), and the lower edge of said cushioning material projects below the lower edge of said working surface (31) such that, prior to punching, said cushioning material and said die (3) co-operatively press to hold the material (A) to be punched. A punching unit for punching apparatus as claimed in any of claims 1 to 3, characterised in that said material (A) to be punched is a ceramic green sheet. A punching unit for punching apparatus as claimed in claim 1, characterised in that a curved cut (19) is formed near the mounting bore (16) in said support section (1), such that said support section (1) can absorb stress caused by punching pressure. A punching unit for punching apparatus as claimed in claim 1, characterised in that said lifting mechanism (4) is disposed in a moving section (42) which slides on the upper surface (14) of the upper half (1a) of the support section (1), and has a piston mechanism (43), said moving section (42) having a curved cut (45), thereby enabling the moving section to absorb stress caused by punching pressure.

Inventors: KAKIMOTO, MASAKAZU
Applicants: USHIO CO. LIMITED
Application year: 1989
Main classification: B26F1
IPC codes: B26F1, B26D7