AU744270B2

AU744270B2 - Pressing apparatus

Info

Publication number: AU744270B2
Application number: AU37522/97A
Authority: AU
Inventors: Mitsuo Matsuoka
Original assignee: Umix Co Ltd
Current assignee: Umix Co Ltd
Priority date: 1997-09-11
Filing date: 1997-09-11
Publication date: 2002-02-21
Anticipated expiration: 2017-09-11
Also published as: AU3752297A

Description

P/00/0 1 1 Regulation 3.2

AUSTRALIA

Patents Act 1 990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: PRESSING APPARATUS The following statement is a full description of this invention, including the best method of performing it known to us: GH REF: P25138-C:DAA:RK

SPECIFICATION

Title of the Invention PRESSING APPARATUS Detailed Description of the Invention Field of the Invention The present invention relates to a pressing apparatus. Background of the Invention In a general type pressing apparatus, a lower die and an upper die are respectively fixed to a bed and a ram of the pressing apparatus, and the upper die is moved up and down to do the punching or the shaping. For pressing the material to be worked from a horizontal direction, a vertical pressing force of the upper die which is moved up and down vertically is converted into a horizontal pressing force by use of a cam member.

example of this will be given below, taking the case of punching a hole in a side wall of a material to be worked with the pressing apparatus having the cam member.

As shown in Figs. 5 and 6, a positioning member 104 for positioning a material 103 to be worked is projected from a lower die 101. A passive cam 107 having a punch 106 is slidably set at a position corresponding to a blanking hole 105 in as de wall of the material 103 to be worked. Behind the passive cam- 107, a heel 108 is fixed. A coiled spring 109 is fitted onto a front end portion of a rod 110 screwed in the passive cam 107 and extending through the heel 108, with the one end contacting with the heel 108 and the other end contacting with a nut 112 threadedly mounted through a washer 111. The coiled spring 109 biases the passive cam 107 so that the passive camn 107 can be pulled back by it after the punching the material 103. An operating cam 118 is projected from the upper die 116 at a position opposite to the passive cam 107.

When the upper die 116 is moved down, the operating cam 118 moves the passive cam 107 forward against a biasing force of the coiled spring to bore a hole 105 in the material 103 via the punch 106 and a die 1- 125. When the upper die 116 is moved up, the passive cam 107 is backed by the biasing force of the coiled spring 109.

The passive cam 107 having the punch 106 is slid on the lower die 102, moving close to or away from the material 104 to be worked, to bore a hole in the side wall of the material 105. The passive cam 107 is required to be slid precisely to bore a hole with the punch 106 and the die 125, and so the passive cam 107 is provided, at each lower side thereof, with a flange 121 projecting therefrom, while also a side guide plate 122 and a upper guide plate 123 for guiding the flange 121 of the passive cam are fixed to the lower die 101.

To allow the passive cam 107 to be slid reciprocally between specified positions in the pressing apparatus, there are provided the side guide plate 122 and the upper guide plate 123 for guiding the side of the flange 121 projecting from the side of a passive cam body 107a and the upper guide .0 .e plate 123 for guiding an upper surface of the flange 121. The provision of the flange 121, the side guide plate 122 and the upper guide plate 123 requires the passive cam body 107a to have a projecting part projecting S from the both sides of the passive cam body by a length 1, as shown in Fig.

6. The length is usually about 100-150mm at the smallest, and so the •oo@• projecting part occupies a large space of the lower die 101 of the pressing o apparatus.

oo Thus, the provision of the cam mechanism in the pressing apparatus requires a large space, and so the size of the pressing apparatus is subject to restriction by an area of bed of the pressing apparatus. There are some occasions when a necessary member cannot be set on the pressing apparatus, which may sometimes require increased working steps and an additional pressing apparatus.

A wear plate 124 at a front end portion of the flange 121 projecting from the side of the passive cam body 107a will be worn out as the passive cam 107 is slid repeatedly, and a gap will be created between the wear plate 124 and the side guide plate 122. This makes it difficult for the Jf.passive cam 107 to be slid straight and causes the passive cam 107 and 2 the punch 106 fixed to the passive cam 107 to snake, thus making it impossible for the punch 106 to punch a hole with keeping a proper clearance from around the die 125. As a result of this, when a hole is punched, an undesirable burr is produced around the punched hole. Thus, a required high level of perforating quality was not able to be achieved. In addition to this, the inaccurately positioned punch 106 and die 125 produce a burr in punching and may cause cutting edges of the punch 106 and die 125 to be broken.

Summary of the Invention In one aspect, a pressing apparatus of the invention comprises a slide cam base provided on an upper die and providing at a front end thereof with a tetrahedron guide; a slide cam which holds the tetrahedron guide of the slide cam base so that the tetrahedron guide can be slid over it S- and to which press-working elements may be fixed; an elastic member S•interposed between the slide cam base and the slide cam to bias the slide Scam; an operating cam provided on a lower die and contacting with the slide cam to drive the slide cam; and a positioning member, provided on S* the lower die, for supporting thereon a material to be worked to be pressed with the press-working elements.

ooo•@ Advantageously, in an embodiment of the invention, there may be provided a pressing apparatus having a cam member which may be e* compact in size, with the required function as the cam member given, and is also inhibited from snaking to achieve a high level of working quality.

Preferably, press-working elements which are fixable to the slid cam include a punch and a trimming/cutting edge.

The slide cam is slid horizontally between the operating cam and the slide cam base to do the press-workings such as the punching and the trimming, when the upper die is moved down. When the upper die is moved up after completion of the press-working, the slide cam is returned to its home position by a biasing force of the elastic member.

Brief Description of the Drawings 3 Fig. 1 is a longitudinal sectional view of an example of the Preferred embodiment of a pressing apparatus of the invention positioned in a bottom dead center; Fig. 2 is a sectional view taken along the arrow Fig. 1; Fig. 3 is a sectional view taken along the arrow Fig. 1; Fig. 4 is a longitudinal sectional view of the pressing apparatus, positioned at a top dead center; Fig. 5 is a front view of a pressing apparatus using a cam mechanism of general type; and Fig. 6 is a side view of Fig. Embodiment Referring now to the accompanying drawing figures 1 through 4, an example g. of the preferred embodiment of a pressing apparatus of the invention is detailed below.

~Fig. 1 is a longitudinal sectional view of an example of the preferred O embodiment of a pressing apparatus of the invention, positioned in a bottom dead center; Fig. 2 is a sectional view as taken along the arrow Fig. l; Fig. 3 is a sectional view taken along the arrow Fig. 1; and Fig. 4 is a longitudinal sectional view of the pressing apparatus, positioned at a top dead center.

Taken as an example of the embodiment is the case of punching a hole in the material to be worked and trimming a bottom edge of the material.

A positioning member 4 for positioning the material 3 to be worked is fixed on a base 2 of a lower die 1 with bolts 5. An operating cam 8, to which a guide member 6 whose top surface is so slanted as to become gradually lower towards the positioning member 4 and is also so formed as to contact with a Vshaped groove is fixed with bolts 7, is fixed in the vicinity of the positioning member 4 with bolts 9.

A slide cam base 13 is fixed on a base 12 of an upper die 11 confronting the operating cam 8 with bolts 14. The slide cam base 13 has at its front end a -4tetrahedron guiding portion 16 of generally square in section. The tetrahedron guiding portion 16 has a slanted surface becoming gradually higher towards the positioning member 4, in contrast to the slanted surface of the operating cam 8, and also has a ridge 15 at the bottom end.

There is provided a slide cam 17 which holds the tetrahedron guiding portion 16 of the slide cam base 13 in a freely slidable manner and is slidable on the guide member 6 of the operating cam 8.

The slide cam 17 comprises a Vee groove member 18 and a working element 19 to which a punch, a cutting edge and the like are fixed. The Vee groove member 18 is positioned by a key 20 knocked in a surface of the working element 19 facing the Vee groove member 18 and is fixed to the working element 19 with bolts 22, with a stopper 21 rising therefrom.

The slide cam 17 has a slanted surface at its top, which is identical to oo So• that of the tetrahedron guiding portion 16 of the slide cam base 13 and is formed into a Vee groove to receive the tetrahedron guiding portion 16. Wear plates 23 are fixed on the slide cam 17 with bolts 24, to support bottom flat surfaces 25 of the tetrahedron guiding portion 16 of the slide cam base 13, and keep plates 28 are fixed to the slide cam 17 with bolts 27, to press top flat surfaces 26 of the tetrahedron guiding portion 16. Through the wear plates 23 o and the keep plates 28, the slide cam 17 is connected with the tetrahedron guiding portion 16 of the slide cam base 13 in a freely sliding manner.

On the bottom of the slide cam 17, a sliding member 29 is fixed with bolts The sliding member 29 is slidable on the guide member 6, with its Vee groove contacting with the guide member 6.

On the slide cam 17 on its side of the material to be worked, a mounting plate 41 is fixed with bolts 42. The punch 43 is fixed via a punch plate 44 fixed to the mounting plate 41 with bolts 45 screwed therein. A trimming cutting edge 51 is fixed to the mounting plate 41 with bolts 46 screwed therein.

A stripper plate 47 is biased by a cushion rubber 48 to press the material 3 to be worked before the material 3 is subjected to the punching and trimming.

A reference numeral 49 denotes a die in which a punch 43 is pressed to do the punching, and a reference numeral 50 denotes a cutting edge 51 which cooperates with a trimming cutting edge to trim an edge portion of the material 3.

A holding hole 61 is recessed in a rear end portion of the tetrahedron guiding portion 16 of the slide cam base 13, to allow the slide cam 17 to be baked after the working. A support plate 62 is located at a position opposite to the holding hole 61 and is fixed to the slide can 17 with bolts 63. An elastic member 64 such as a coiled spring is provided between the holding hole 61 and the support plate 62 with compressed. When the upper die 11 is moved up, the slide cam 17 is backed by a biasing force of the elastic member 64. To stop the backward movement of the slide cam 17, the stopper 21 rising from the slide cam 17 is brought into engagement with an end 65a of a stop groove formed at a ridge portion of the tetrahedron guiding portion 16 of the slide cam base 13 at the bottom thereof. A safety stopper 66 is screwed in the holding hole 61 to position the coiled spring in place. The safety stopper 66 extends through the support plate 62 and has a head 66a at the end. In case the stopper 21 fails to stop at the end 65a of the stop groove 65, the support plate 62 is brought into abutment against the head 66a to stop the backward movement of the slide cam, for safety.

In order to force the slide cam 17 to be backed when the upper die 11 is moved up, a return plate 71 is fixed to the slide cam 17 with bolts 72, with its bottom end engaged with the operating cam 8.

Next, operation of the pressing apparatus is described below.

As shown in Fig. 4, the material 3 to be worked is put on the positioning member 4 and then the upper die 11 is moved down. Shown in Fig. 4 is the state of the pressing apparatus being positioned at a top dead center. In this state, the slide cam 17, which is connected with the tetrahedron guiding portion 16 of the slide cam base 13 fixed to the base 12 of the upper die 11 in a freely sliding manner, is in contact with the stopper 21.

-6- When the upper die 11 is moved down from this state, the sliding member 29 of the slide cam 17 comes to contact with the guide member 6 the operating cam 8.

As the upper die 11 is moved down further, the slide cam 17 is driven to move forward between the operating cam 8 and the slide cam base 13 towards the material 3 to be worked, so as to punch the material 3 with the punch 43 and trim a lower part of the material 3 with the trimming cutting edge 51.

Shown in Fig. 1 is the state of the material 3 being punched and trimmed with the punch 43 and the trimming cutting edge 51 and of the upper die 11 being in the bottom dead center.

When the upper die 11 is moved up from this state, a biasing force of the elastic member 64 is transmitted from the support plate 62 to the slide cam 17, so that the slide cam 17 is driven backward and is stopped with the stopper 21 at the slide cam 17 brought into contact with the end 65a of the stop groove If the slide cam 17 is not moved backward for some reason, the return plate 71 provided at the slide cam 17 is brought into engagement with the operating cam 8 to force the slide cam 17 to be backed.

Described above is just an example of the embodiment being applied to the 9 punching and the trimming. It is needless to say that the embodiment is also applicable to the other press-workings such as the shaping or bending.

Standardization of size of the slide cam base 13, the slide cam 17 and the operation cam 8 is desirable for quick working of the materials to be worked of S"different sizes.

As mentioned above, the pressing apparatus of the invention comprises a slide cam base provided on an upper die and providing at a front end thereof with a tetrahedron guide; a slide cam which holds the tetrahedron guide of the slide cam base so that the tetrahedron guide can be slid over it and to which press-working elements including a punch and a trimming cutting edge-are fixed; an elastic member interposed between the slide cam base and the slide cam to bias the slide cam; an operating cam provided on a lower die and contacting with the slide cam to 12 drive the slide cam; and a positioning member, provided on -7the lower die, for supporting thereon a material to be worked to be pressed with the press-working elements. Thus, according to the invention, the flanges and the associated side guide plates and upper guide plates, which are included in the cam mechanism of conventional type, are not needed for the cam mechanism, and so a minimum space for the cam mechanism is just needed in the pressing apparatus.

The general type cam mechanism requires a large space, and so the size of the pressing apparatus is subject to restriction by an area of bed of the pressing apparatus. Due to this, there are some occasions when a necessary member cannot be set on the pressing apparatus, which may sometimes require increased working steps and an additional pressing apparatus. However, the invention can eliminate the need for provision of an additional pressing apparatus for such a reason.

The cam mechanism of the invention which needs no large space enables a material to be worked having a curved surface to-be worked from a suitable direction to the curved surface, the direction of the normal to the curved surface. This can provide the result that in the punching for example, the punched bore is formed into a complete round, not ellipse, thus improving the level of quality of the working.

addition, the invention not only enables the size, weight and manufacturing costs of the pressing apparatus to be reduced but also enables the time required for finishing the pressing apparatus to be reduced. The reduced size of the pressing apparatus provides the advantage that machine tools and cranes used for machining the pressing apparatus in the factory can be reduced in size.

Further, with the pressing apparatus of the invention, since the slide cam is so held by the slide cam base as to be freely slid, even in the case of the wearing of the sliding portion of the slide cam in a long term use, the cam is kept from snaking and can be moved straight, differently from the general type of pressing apparatus. As a result, the high level of quality of the press- -8working can be achieved. Besides, since the slide cam base is moved straight correctly, breakage of edges of the punch, the die and the cutting edge can be avoided. In the embodiment of the invention, since the sliding surfaces of the slide cam and the operating cam are formed into a Vee groove, the cam can be avoided snaking.

Furthermore, according to the invention, since the sliding mechanism located at the center of the cam can be divided into small parts to be held at more points, the cam can be held in safety, as compared with the conventional type sliding mechanism in which the flanges are projected from both sides of a large member and are held at both sides only.

Besides, according to the invention, standardization of the components of the cam is desirable for quick working of the materials to be worked of different sizes.

o -9-

Claims

1. A pressing apparatus comprising a slide cam base provided on an upper die and providing at a front end thereof with a tetrahedron guide; a slide cam which holds said tetrahedron guide of said slide cam base so that said tetrahedron guide can be -slid over it a'pd to which press-working elements may be fixed; an elastic member interposed between said slide cam base and said slide cam to bias said slide cam; an operating cam provided on a lower die and contacting with said slide cam to drive said slide cam; and a positioning member, provided on said lower die, for supporting thereon a material to be worked to be pressed with said press-working elements.

2. The pressing apparatus in accordance with claim 1, where the slide cam is arranged to have press-working elements including a punch and a trimming/cutting edge to be fixed to it.

3. Apressing apparatus substantially as herein described with reference to the accompanying drawings. Dated this 5th day of September 1997 UMIX CO., LTD. By their Patent Attorney GRIFFITH HACK 10