GB2217633A

GB2217633A - Pressing machine for manufacturing metal product

Info

Publication number: GB2217633A
Application number: GB8907755A
Authority: GB
Inventors: Toshiaki Kawada; Michio Tsukamoto; Yasuyuki Nakayama; Takanobu Kobayashi
Original assignee: KOBAYASHI METAL WORKS Co
Current assignee: KOBAYASHI METAL WORKS Co
Priority date: 1988-04-08
Filing date: 1989-04-06
Publication date: 1989-11-01
Anticipated expiration: 2009-04-06
Also published as: GB8907755D0; JP2584729B2; KR930004865B1; KR890015797A; JPH01258823A; CN1040524A; CN1015514B; MY104425A; GB2217633B

Abstract

A pressing machine is provided for manufacturing metal products from strip-like material 10. The pressing machine comprises a lower die block 2 carrying punching dies 12, 13, 13' disposed symmetrically on either side of the centre line I of the feed path of material 10, and an upper die block (3, Fig. 4) having corresponding upper punches. Pushing mechanisms 4 transfer the punched workpieces 20, 20' to two sets of bending dies 31, 31' (51, 51', Fig. 4) for bending the workpieces to produce products 30, 30. The products 30 are bi-metallic correcting brackets for mounting the shadow mask (71, Fig. 8) in a television tube. <IMAGE>

Description

SPECIFICATION TITLE OF THE INVENTION PRESSING MACHINE FOR MANUFACTURING METAL PRODUCT FIELD OF THE INVENTION This invention relates to a pressing machine for die punching a metal product from a material and working as required and, more particularly, to a pressing machine for manufacturing a metal product to die punch a metal product in a predetermined shape and to bend the product already die punched simultaneously.

DESCRIPTION OF THE PRIOR ART When it is considered to manufacture a metal product of the type such as, for example, a planar L shape or a hook shape, it is heretofore ordinary to sequentially punch a strip-like material by a set of punch and die block while being intermittently feeing the material at a predetermined pitch and to then work, such as bend the punched product.

The waste of the material is slightly much but the steps are simplified to be preferable for a mass production. There is as an example of the product a bimetal bracket for correcting a shadow mask for a TV Braun tube at the inside of a front face protective glass at its temperature and holding it.

Recently, a strip-like material called "a trimetal" of the structure that an amber is disposed at a center and stainless steels are bonded at both right and left sides is supplied. However, since the trimetal is broad in width, many wastes are produced by the above-mentioned punching work. If a die punching is so settled at this strip-like material as to be symmetrical with respect to the central material, the material can be saved, but it is necessary to settle the postworking of the symmetrically die punched product symmetrically. To this end, it is required to provide punching machines at both right and left sides, and it becomes complicated to consider the sequence of workings and the management of the steps.

SUMMARY OF THE INVENTION Accordingly, an object of this invention is to provide a pressing machine for manufacturing a metal product which can solve the problems described above and which can save a strip-like material, such as a trimetal described as above by die punching a product symmetrically and can also work the symmetrically die punched product in efficiency equivalent to or higher than the conventional bimetal.

The above object of the invention can be achieved by a pressing machine for manufacturing a metal product comprising two sets of lower die blocks each having punching dies for pressing a strip-like material fed longitudinally to alternately punch products at right and left sides symmetrically with respect to the center line of the strip-like material and upper die blocks each having punching dies, disposed longitudinally in the feeding direction, a pushing mechanism mounted telescopically between the lower die block and the upper die block for pushing the two right and left products thus die punched sidewisely of the lower die block to set the products in a predetermined attitude to a bending die, and two sets of bending dies disposed at the lower die block side and bending punches disposed at the upper die block side for bending the two products set to the bending dies symmetrically to simultaneously press and bend the products, the two sets of the punching dies and the punches having the same shape and structure.

One set of the lower die block having the punching die and the upper die block having the punch punches one product. When two sets of the pressing dies are disposed longitudinally in the feeding direction, the products can be pressed in the direction symmetrical at the right and left sides of the center line (Fig. 7).

The two right and left side products thus die punched of the same shape and structure are so pushed by the pushing mechanism as to dispose the bent portions of the products on the bending line set at the sides of the feeding direction. Thus, the two bending dies are provided rotatably symmetrically at the right and left sides of the bending line.

The bent portions of the products, not disposed in the feeding direction are arbitrarily set easily by the bending dies. Thus, the operating timing of the bending die is brought into coincidence with the operating time of the pressing die, and the intermittent feeding of the striplike material on the pressing die, the pushing of the material to set the die punched product to the bending die and the exhaust of the final product thus bent are synchronized to obtain the same products by simultaneously working the products disposed in different directions.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front view showing an embodiment of a pressing machine for manufacturing a metal product according to this invention; Fig. 2 is a side view of the embodiment; Fig. 3 is a plan view of a lower die block; Fig. 4 is a plan view of an upper die block; Figs. 5(a) and 5(b) are plan and sectional views of the essential portion of the pressing surface; Figs. 6(a) and 6(b) are plan and sectional views similar to Fig. 5 at the time of operating a pushing mechanism; Fig. 7 is a perspective view of a produced obtained from a strip-like material; Fig. 8 is a partial perspective view of an example of used product; and Fig. 9 is an explanatory view of the steps.

DESCRIPTION OF THE PREFERRED EMBODIMENTS This invention will be described in detail with reference to the drawings. In Figs. 1 and 2, reference numeral 1 denotes a body of a pressing machine of this invention, numeral 2 denotes a lower die block provided at the lower position of a working portion, numeral 3 denotes an upper die block provided at the upper position of the working portion, numeral 4 denotes a pushing mechanism settled to push a product beforehand from the deep portion of the lower die block 2, numeral 5 denotes a pressing machine or a press having a stationary lower die block at the lower portion and the movable upper die block at the upper portion, and an elevational moving mechanism, numeral 6 denotes a material feeding mechanism, numeral 7 denotes an operation board, numeral 8 denotes a gauge for indicating the cranking angle of the press, and numeral 9 denotes an operation button box.

The stationary lower die block 2 has a structure as shown in Fig. 3, and has four dies disposed longitudinally at the feeding passage 11 of a strip-material 10 fed from the left to the right of the body 1 as a center. Numeral 12 denotes a positioning die having positioning die holes 12a and 12b, numeral 13 denotes a first punching die having an L-shaped product profile hole 13a, numeral 13' also denotes a second punching die having the same shape and structure as those of the first punching die 13 and disposed rotatably symmetrically with respect to the center line 1 of the feeding direction of the strip-like material 10.Numeral 14 denotes a feeding die for the strip-like material 10, numeral 15 denotes a perforating die for perforating a necessary hole at the product simultaneously upon die punching, and numeral 16 denotes elevationally movable lifters provided at the dies 12 to 14.

The strip-material 10 here employs a trimetal described above (Fig. 7), and is fed while the material 10 is restricted by guides 17 protruding from the front and rear sides toward the top of the feeding passage 11 of the four dies 12 to 14. The longitudinally positioning die holes 12a and 12b are provided at an interval of a pitch length p for intermittently feeding the strip-like material 10, and the pitch length p is, of course, longer than the length of the product and displaced at the distance of the longitudinal displacement of the hook type of the right and left side products. Numeral 18 denotes the through holes of guide posts provided at the four corners of the lower die block 2.

The pushing mechanisms 4 are provided in the deep portion of the lower die block for the first and second dies 13 and 13'. The punching mechanism 4 has pusher plates 21 and 21' including different end shapes and longitudinally movable under the guidances of pusher guides 22 and 22'. Numeral 23 denotes the contacting surface of the end of the first pusher plate, which has a shape for so correcting the attitude of the product die punched as to accurately contact the positioning surface 32 of a bending die 31 at one side 13b of the forwarding product thus die punched. The contacting surface 23' of the end of the second pusher plate has a shape for accurately contacting one side 13c' of the product thus die punched of different attitude (symmetrical to the first one) with the positioning protrusions 35' and 36' of the second bending die 31'.Numerals 24 and 24' denote mechanisms for forwarding or reversing the pusher plates 21 and 21' of air cylinder type, as shown. Numerals 25 and 25' denote piston rods of the mechanisms 24 and 24'. The mechanism 24 and 24' may also employ, in addition to the air cylinder type, arbitrary driving type.

Bending sections are provided at the ends of the respective pushing mechanisms 4, and the produced thus die punched is received on the bending die 34 lower than the the slide surface 33 having the same height as the upper surface of the lower die block 2. Numerals 35 and 36 denote positioning protrusions provided at the positions opposite to the positioning surface 32 to contact the other side 13c of the product thus die punched to be fixed in the bending die 34. Numerals 35' and 36' denote positioning protrusions ahead of the second slide surface 33' to protrude beforehand reversely to the first side. The bending die 34 generally has three portions, first and second folding lines 34a and 34b, 34a' and 34b' crossing perpendicularly the strip-like material feeding direction, and third bending die surfaces 34c and 34c' being parallel to the strip-like material feeding direction.

The upper die block 3 has a structure to be associated with the lower die block, and has a pressing portion and a bending portion of punches of the shape corresponding to the dies of the lower die block. Numeral 41 denotes an upper portion corresponding to the feeding passage, numeral 42 denotes a stripper plate of the punch, numerals 43 and 43' denote stripper plates of first and second punches, numeral 44 denote an output side punch, numeral 45 denotes a perforating punch, numerals 42a and 42b denote positioning punches, numeral 48 denotes upper through hole of the guide post, numerals 49 and 49' denote first and second punches provided to punch the product profile in the upper die block, numerals 51 and 51' denote first and second bending dies, numerals 52 and 52' denote the positioning surface similar to those of the punch side, numeral 54 and 54' denotes bending punches having three folding lines 54a, 54b, 54c, and 54a', 54b', 54c'.

Fig. 7 shows the steps of pressing the strip-like material 10 to manufacture die punched products 20 and 20' to final products 30. Numerals 61 and 61' denote positioning holes perforated at the die holes 12a and 12b, numerals 62 and 62' denote engaging holes perforated by the perforating die 15, numerals 63b and 63b' denote one sides, and 63c' and 63c' denote the other sides. The final product 30 is a bracket used as shown in Fig. 8. The strip-like material 10 has an amber material 10a at the center and stainless steel materials 10b at both sides.

Numeral 71 denotes a shadow mask, numeral 72 denotes a front face protective glass of a Braun tube, numeral 73 denotes a protrusion protruding from from the inner surface to be engaged with the engaging hole 62 (62') for positioning.

Pressing sequence In the pressing machine constructed as described above, the strip-like material 10 is fed at a predetermined distance to the feeding passage 11, and stopped thereat.

When the upper die block 3 moves down, the strip-like material 10 is perforated with positioning holes 61, 61' and engaging holes 62, 62' at the positioning die holes 12a, 12b. Then, when the upper die block moves up and fed again at one pitch length p, next perforating work is carried out similarly to the above operation.

Simultaneously, the die punching work of the first die punch 49 is then performed at one side of the strip-like material 10 along the product profile hole 13a at the first punching die 13.

Then, when the strip-like material 10 is fed at one pitch length p, second punching is carried out by the first die punch 49. When third punching is executed by the first punch 43, the other side of the strip-like material 10 is initially punched by the second punch 49' (in the state as shown in Fig. 7). Thereafter, the strip-like material 10 is die punched at both sides by the first and second punching dies 13 and 13', and the first and second punches 49 and 49'.

The products 20, 20' thus die punched are fed to the bending dies 34 and 34' by the operations of the first and second pusher plates 21, 21' until the upper die block is moved upward and the strip-like material 10 is then fed at one pitch. When the material is completely fed, the setting is finished, the upper die block is moved down, and the products are then bent by the bending punches 54, 54' and the bending dies 34, 34' substantially simultaneously when the products are punched.

This working steps are carried out, for example, as shown in Fig. 9. Angles 0 to 3600 denote the progress of the steps corresponding to the cranking angle of the press.

The strip-like material 10 is, for example, fed at the timing at 2700 to 900 of the cranking angle. Then, the products 20, 20' are punched by the punches from the vicinity of 1250. Further, in order to stabilize the products 20, 20' in the punching dies 13, 13', the products 20, 20' are retained by pins in the punches, the pusher plates 21, 21' start operating from the vicinity of 2150 immediately after the products 20, 20' are separated from the pins, the products 20, 20' are then fed into the bending dies 34, 34'. In this case, in order that the products 20, 20' are positioned in the die block, the pusher plates 21, 21' are temporarily stopped when the products 20, 20' are stabilized at the home positions (3070 to 357 ), they are returned to the original positions before next punching is started, the products 20, 20' thus fed to be die punched are retained from the vicinity of 1480 to the vicinity of 1550, the final products 30 are completely exhausted while product exhausting errors are output to the vicinity of 2040 to 2460, thereby completing one cycle.

According to this invention as described above, the strip-like material fed longitudinally can be alternately die punched at the right and left sides symmetrically through the center line thereof, the products thus die punched are symmetrically bent, thereby manufacturing the products of entirely the same shape and structure finally by pressing to save the material. The punching dies and die punches of the same shape and structure are disposed symmetrically through the center line of the strip-like material feeding direction, the pushing mechanism, the bending dies and the bending punches are entirely constructed the same. Since they may be partly altered, the entire structure of the pressing machine is vary rationalized to simplify the operability and the management of the steps, thereby providing remarkably practical effect.

Claims

WHAT IS CLAIMED IS:

1. A pressing machine for manufacturing a metal product comprising two sets of lower die blocks each having punching dies for pressing a strip-like material fed longitudinally to alternately punch products at right and left sides symmetrically with respect to the center line of the strip-like material and upper die blocks each having punching dies, disposed longitudinally in the feeding direction, a pushing mechanism mounted telescopically between the lower die block and the upper die block for pushing the two right and left products thus die punched sidewisely of the lower die block to set the products in a predetermined attitude to a bending die, and two sets of bending dies disposed at the lower die block side and bending punches disposed at the upper die block side for bending the two products set to the bending dies symmetrically to simultaneously press and bend the products, the two sets of the punching dies and the punches having the same shape and structure.