GB2240739A

GB2240739A - Forming machine

Info

Publication number: GB2240739A
Application number: GB9002923A
Authority: GB
Inventors: Nobuyuki Ishinaga; Takashi Nakano
Original assignee: Aida Engineering Ltd
Current assignee: Aida Engineering Ltd
Priority date: 1990-02-09
Filing date: 1990-02-09
Publication date: 1991-08-14
Anticipated expiration: 2010-02-09
Also published as: GB9002923D0; DE4004764A1; GB2240739B

Abstract

A forming machine for fully enclosed die forging has respective punches 61, 69 inserted into a pair of dies 52, 55 facing each other. The die 55 is supported by one end of a ring member 67 accommodated in a holder 71. The other end of the ring member 67 is disposed wthin a cylinder chamber 85 formed within the holder 71. The ring member 67 has a piston member 75 disposed within it and the punch 69 is supported by one end of the piston member 75. The other end of the piston member 75 is disposed in the above cylinder chamber formed within the holder 71 or a cylinder chamber communicating with the holder 71. When a top slide of a press moves down, the upper die 53, lower die 55 and ring member 67 move down, and this lowering movement of the ring member pushes hydraulic fluid from the cylinder chamber 85 into the cylinder chamber having the piston member 75 disposed therein, thereby moving the piston member 75 upward and the lower punch 69 upward as well to thereby forge a billet 13 between the dies. <IMAGE>

Description

SPECIFICATION

Title of the Invention:

Forming Machine Background of the Invention: Field of the Invention:

This invention relates to a forming machine used fo full enclosed die forging etc.

Description of the Prior Art:

Generally, a full enclosed forming method that a punch is inserted into at least one of a pair of dies to have the punch and the die relatively displaced, thereby deforming a material or a processing method for punching a material is being used extensively to reduce times of forming steps, produce complicated-shaped products, pierce.without deforming the entire shape, and improve material yields.

For example, making a formed product 11 as shown in Fig. 12 (a) from a material 13 as shown in Fig. 12 (b) requires several steps when an ordinary swaging is applied. But, such steps can be reduced to one step by employing a forming method consisting of holding the material 13 with i i 1 upper and lower dies 17, 19 and moving a punch 21 in the direction ot arrow A.

The above step requires force to keep the upper and lower dies 17, 19 contacted or a closing force.

Fig. 14 shows a forming machine to effect the forming method of Fig. 13, in which reference numerals 17, 19 indicate upper and lower dies vertically disposed to face each other.

The upper die 17 is supported by an upper holder 25 which is fixed to an upper die set plate 23. The upper die 17 has an upper punch 27 inserted therein, which upper punch 27 has the bottom end of a knockout pin 29 contacted thereto.

The lower die 19 is supported by a ring member 33 through a ring 31. Both lower die 19 and ring member 33 have a lower punch 35 inserted therein.

Into the ring member 33 is inserted a column part 41 of a plate 39 which has its bottom end fixed to a lower die set plate 37.

The ring member 33 is disposed within a lower holder 43 which guides the ring member 33 to vertically move freely. This lower holder 43, the bottom end of the ring member 33 and the plate 39 form a cylinder chamber 45.

2 j 1 0 1 i f With the forming machine structured as described above, first a slide (not shown) lowers from a state illustrated in the left half of Fig. 14, the upper die 17, lower die 19 and ring member 33 lower as shown in the right half of Fig. 14, but the lower punch 35 moves relative to the lower die 19 because the lower punch 35 is fixed, and the material 13 is subjected to closed forming to produce the formed product 11.

This forming machine supplies hydraulic fluid into the cylinder chamber 45 to move the ring member 33 upward, and at the same time discharges the extra fluid outside through a relief valve 51 by the downward movement of the ring member 33, thereby providing the closing force for the upper die 17 and the lower die 19.

However, in such a conventional forming machine, the upper die 17 and the lower die 19 require the closing force much greater than required for closing, and a great slide stroke is required, thus causing a disadvantage of increasing the required workload of the press.

More specifically, to produce the formed product 11 as shown in Fig. 12 (a) for example, the closing force required at a bottom dead center becomes maximum as shown in Fig. 15, so that the closing force is required to be set based on the bottom dead center. Load PF of the lower punch 19 varies 6 i as shown by a dotted line with respect to the moving slide, and the closing force given is much greater than required until the slide reaches about the bottom dead center. And the ring member 33 needs a stroke S, as shown in Fig. 14, requiring workload corresponding to the area of the section enclosed by slant lines as shown in Fig. 15.

As a result, a press with greater torque capacity is needed, and the energy required for forming increases.

Besides, since the upper and lower dies 17, 19 start contacting at a position much higher than the bottom dead center, automated parts have inferior approach in automated production, and a press with a long slide stroke is required.

Further, forming an excessively voluminous material may damage the dies, and the upper and lower dies 17, 19 do not contact to each other, resulting in having difficulty to secure a prescribed-sized formed product 11.

A forming machine similar to the one described above is known disclosed in Japanese Patent Publication No. 56-21498. This machine is fixed to a mechanical press, and each hydraulic pressure supplying device is disposed outside of the forming machine, requiring troublesome work for replacement of dies, maintenance, etc. with inferior flexibility to be applied to make various formed products.

i j 0 Summary of the Invention:

An object of this invention is to provide a forming machine capable of preventing excess application of a closing force.

Another object of this invention is to provide a forming machine which is capable of extensively lowering a closing force and a slide stroke as compared with conventional ones, is easy to maintain or replace dies, and is excellent in flexibility to various formed products.

Brief Description of the Drawincfs:

Fig. 1 is a longitudinal sectional view showing the first embodiment of a forming machine of the present invention.

Fig. 2 is a longitudinal sectional view showing a condition that a material is supplied to the forming machine of Fig. 1.

Fig. 3 is a graph showing the relation between slide displacement and load of the forming machine of Fig. 1.

Fig. 4 is a longitudinal sectional view showing the second embodiment of the forming machine of this invention.

Fig. 5 is a transverse sectional view taken on line V-V of the forming machine of Fig. 4.

- i i Fig. 6 is a longitudinal sectional view showing a condition that a material is supplied to the forming machine of Fig. 4.

Fig. 7 is a graph showing the relation between slide displacement and load of the forming machine of Fig. 4.

Fig. 8 is a longitudinal sectional view showing the third embodiment of the forming machine of this invention.

Fig. 9 is a transverse sectional view taken on line IX-IX of the forming machine of Fig. 8.

Fig. 10 is a longitudinal sectional view showing a product formed by the forming machine of Fig. 8.

Fig. 11 is a graph showing the relation between slide displacement and load of the forming machine of Fig. 8.

Fig. 12 is a side view showing a material and one embodiment of a Fig. 13 is forming method.

Fig. 14 is a longitudinal sectional view showing one embodiment of a conventional forming machine.

Fig. is is a graph showing the relation between slide displacement and load of the forming machine of Fig. 11.

formed product.

an explanatory view showing a full enclosed Description of the Preferred Embodiment of the Invention:

i i Now, the present invention will be described in detail with reference to the attached drawings.

Fig. 1 shows one embodiment of a forming machine of this invention; the left half showing a condition of the material 13 prior to forming and the right half, after forming.

Reference numerals 53, 55 indicate upper and lower dies vertically disposed to face each other.

The upper die 53 is supported by an upper holder 59 fixed to an upper die set plate 57 and has an upper punch 61 inserted therein. This upper punch 61 has the bottom end of a knockout pin 63 contacted thereto.

The ring member 67 is disposed within a lower holder 71 which guides the ring member 67 to vertically move freely. The bottom end of the lower holder 71 is fixed to a lower die set plate 73.

In this embodiment, within the ring member 67 is disposed a piston member 75 to be freely movable vertically, and the top of the piston member 75 supports the bottom end of the lower punch 69.

A member 77 formed at the upper part of the ring member 67 and the upper surface of the piston member 67 have a spring 79 disposed to move the piston member 67 downward.

Into the piston member 75 is inserted the column - 7 1 1 section 83 of a plate 81 whose bottom end is fixed to the lower die set plate 73.

The piston member 75, the bottom end of the ring member 67 and the plate 81 form a cylinder chamber 85.

The lower holder 71 is provided with a through hole 87 communicated to the cylinder chamber 85. The through hole 87 is connected with a pipe 90 which is connected to a hydraulic fluid supply device 89. This pipe 90 is provided with a check valve 91 and a hydraulic pump 92, and a relief valve 93 is disposed downstream the check valve 91.

Mark 0 in the drawing indicates an oil seal, and in this embodiment, the lower end area of the ring member 67 has an area S same to that of the bottom end of the piston member 75.

In the forming machine structured as described above, as shown in Fig. 2, with the cylinder chamber 85 filled with the hydraulic fluid, a slide moves downward and the upper die set plate 57 lowers to move the upper die 53, the lower die 55 and the ring member 67 down, and this downward movement of the ring member 67 pushes the hydraulic fluid within the cylinder chamber 85 against the piston member 75, thereby moving the piston member 75 and the lower punch 69 upward.

The forming machine structured as described above 1 1 i 1 j i i i 1 allows the closing force and slide stroke to be extensively lower than before by disposing the piston member 75 within the ring member 67, supporting the lower punch 69 by one end of the piston member 75, positioning the other side of the piston member 75 within the cylinder chamber 85 formed in the lower holder 71, and making the bottom end area of the ring member 67 and that of the piston member 75 to have the same area S.

Specifically, the forming machine structured as above can reduce the sliding stroke required for forming more extensively than before by making the bottom end area of the ring member 67 and that of the piston member 75 to have the same area S; the ring member 67 lowers by a distance S2 and the piston member 75 moves upward by the same distance S2, and the slide stroke required to produce the product 11 as shown in Fig. 12 (a) is a half of the conventional stroke as shown in Fig. 3.

Andf in the above forming machine, the bottom end area of the ring member 67 and that of the piston member 75 are formed to have the same area S, so that the load required to lower the lower die 55 by the upper die 53 or the closing force agrees with the load PF of the lower punch and varies with the degree of filling of the material 13 into a cavity 9 - - 1 95. Therefore, the closing force much greater than required does not apply unlike the conventional forming machines.

Thus, it is possible to make the closing force for closing the upper and lower dies 53, 55 be an appropriate value according to the forming condition, and since the slide stroke required for forming becomes short, energy required for forming can be lowered.

As a result, forming can be effected by using a press with a small torque capacity, and a press with a short slide stroke can be employed for automated production.

The upper and lower dies 53, 55 are not contacted by the forming force much greater than required, so that the service life of these dies 53, 55 can be extended.

In the forming machine structured as described above, a hydraulic pressure is generated within the cylinder chamber 85 by the forming load of the lower punch 69, eliminating necessity of providing a large external hydraulic pressure supplying device as before. The hydraulic fluid supply device 89 is sufficiently provided to supply the hydraulic fluid.

In this embodiment, the hydraulic fluid supply device 89 is provided with the relief valve 69, and adjusting the set pressure makes it possible to set the forming load of the lower punch 69 at about the bottom dead center, - 10 a i i 1 1 eliminating a possible damage to the dies in case of forming an excessively voluminous material.

In this case, at the end of forming once, portion of the hydraulic operating fluid in the cylinder chamber 85 is discharged outside through the relief valve 93 to move the press slide upward. And by the time the next forming starts, the hydraulic operating fluid is supplied into the cylinder chamber 85 by the hydraulic fluid supplying device 89 to make the hydraulic operating fluid in the cylinder chamber 85 to be a prescribed amount.

in addition, in the forming machine structured as described above, almost all of the components of the forming machine can be accommodated in the die set, making the entire size to be very small. Therefore, it is very easy to replace or maintain the upper and lower dies 53, 55, the upper and lower punches 61, 69, etc., allowing the replacement of the entire machine in a short time.

It is also very easy to replace the ring member 67 and the piston member 75. These members can be replaced to easily vary the ratio of the closing force and the forming load (lower punch load). Thus, the present machine is superior in flexibility to produce many various formed products.

11 - The above embodiment described to use the spring 79 to move the piston member 79 down, but this invention is not limited to the above embodiment. For example, a hydraulic, pneumatic, or any cylinder may be used to move the piston member 75.

In the above embodiment, an example of forming the product shown in Fig. 12 (a) was described, but this invention is not limited to that embodiment. For example, it becomes possible to easily form gears etc. by forming a cavity in the form of a gear or the like.

Further, the above embodiment described an example of providing the cylinder chamber 85 below the lower die 55, but this invention is not limited to that embodiment. For example, the machine may be designed upside down to dispose the cylinder chamber 85 on the slide side, and the dies may be horizontally disposed to face each other.

Besides, the above embodiment described an example of making the bottom end area of the ring member 67 and piston member 75 to be same, but this invention is not limited to that embodiment. The bottom end area of the ring member 67 and piston member 75 can be varied based on the shape of a product to be formed, so that forming can be effected by an optimum closing force.

Fig. 4 shows the second embodiment of the forming 1 i v machine of this invention, in which the left half shows a state before forming a material 113 and the right half, after forming.

In the drawing, reference numerals 153, 155 show upper and lower dies vertically disposed to face each other.

The upper die 153 is supported by an upper holder 159 which is fixed to an upper die set plate 157 and has an upper punch 161 inserted therein. The upper punch 161 is in contact with the bottom end of a knockout pin 163.

The lower die 155, on the other hand, is supported by a die plate 167 through a ring 165. The lower die 155 and die plate 167 have a lower punch 169 inserted therein.

The die plate 167 is disposed within a guide 170 which guides the die plate 167 to vertically move freely. The bottom end of the guide 170 is fixed to the top of a holder 171.

The bottom end of the holder 171 is fixed to a lower die set plate 173.

In the above embodiment, the holder 171 is provided at its center with a piston member 175 which supports the lower punch 169.

Around the piston member 175 of the holder 171 are disposed a plurality of two-part piston members 176 which support the die plate 167.

z These two-part piston members 176 consist of a pin 177 and a piston 178. As shown in Fig. 5, these two-part piston members 176 are disposed at the prescribed angle on the same circumference of a circle and accommodated in cylinder chambers 179 which are integrally formed with th6 holder 171.

In this embodiment, 12 cylinder chambers 179 are formed to accommodate the pistons 178, and only 8 pins 177 are disposed as indicated by the hatched lines. This means that there are 8 two-part piston members 176.

The holder 171 is provided with a through hole 187 communicated to the cylinder chamber 179. The through hole 187 is connected with a pipe 190 which is connected to a hydraulic fluid supply device 189. This pipe 190 is provided with a check valve 191 and a hydraulic pump 192, and a relief valve 193 is disposed downstream the check valve 191.

Mark 0 in the drawing indicates an oil seal, and in this embodiment, the lower end area of the cylinder chamber 181 accommodating the piston member 175 has an area S same to the total of all bottom end areas of the cylinder chambers accommodating the two-part piston members 176. This means that the lower end area of one cylinder chamber 14 - z j i j 179 to the bottom end area S of the cylinder chamber 181 is 1/8s.

In the forming machine structured as described above, as shown in Fig. 6, with the cylinder chambers 179, 181 filled by the hydraulic fluid, the slide moves down and the upper die set plate 157 lowers to move the upper die 153, lower die 155 and die plate 167 downward. This downward movement of the die plate 167 causes the two-part piston members 176 to push the hydraulic fluid from the cylinder chambers 179 into the cylinder chamber 181 for the piston member 175, thereby moving the piston member 175 upward and the lower punch 169 upward too.

The forming machine structured as described above consists of a pair of the upper and lower dies 153, 155 disposed to face each other, the lower punch 169 to be inserted in the lower die 155, the die plate 167 to support the lower die 155 in which the lower punch 169 is inserted, the holder 171 disposed opposite to the lower die 155 of the die plate 167, the piston member 175 to support the lower punch 169 disposed at the center of the holder 171, a plurality of the two-part piston members 176 to support the die plate 167 disposed outside of the piston member 175 of the holder 171, and a communication path 182 communicating the cylinder chamber 181 accommodating the piston member 175 - 15 with the cylinder chambers 179 accommodating the two-part piston members 176. And the bottom end area of the cylinder chamber 181 accommodating the piston member 175 has an area S which is same to the total of the bottom end areas of the cylinder chambers 179 accommodating the two-part piston members 176, enabling to decrease the closing force and slide stroke greatly as compared with the conventional ones.

In other wordsf the korming machine structured as described above has the bottom end area of the cylinder chamber 181 accommodating the piston member 175 made to have an area S which is same to the total area of the bottom end areas of the cylinder chambers 179 accommodating the two-part piston members 176, so that when the die plate 167 and the two-part piston members 176 move downward by a distance S2, the piston member 175 moves upward by the same distance S2. Therefore, the slide stroke required for the production of the formed product 111 as shown in Fig. 4 is a half of the conventional stroke, enabling to decrease the slide stroke greatly than before.

Since the forming machine structured as described above has the bottom end area of the cylinder chamber 181 accommodating the piston member 175 made to have an area S which is same to the total area of the bottom end areas of the cylinder chambers 179 accommodating the two-part piston - 16 i members 176, the load required to move the lower die 155 down by the upper die 153 or the closing force agrees with the load PF of the lower punch 169 and varies according to the filling degree of the material 113 into a cavity 195, so that it is not necessary to keep the closing force much greater than required to be applied constantly as in the conventional machine.

This is because that the closing force to close the upper die 153 and the lower die 155 becomes small, and the slide stroke for forming is shortened, reducing the required work to be done by the press and the energy required for forming.

As a result, forming can be done by a press with a small torque capacity and also by a press with a short slide stroke for automated production.

Since the upper and lower dies 153, 155 do not contact to each other by the closing force greater than required, enabling to extend the service life of the upper and lower dies 153, 155.

Besides, the forming machine structured as described above employs the forming load of the lower punch 169 to generate the hydraulic pressure in the cylinder chamber 181, eliminating the necessity of externally providing a large size hydraulic pressure supply device unlike the conventional machines. It is sufficient by simply disposing the hydraulic fluid supply device 189 which supplies the hydraulic fluid.

In this embodiment, the hydraulic fluid supply device 189 is provided with a relief valve 193, whose specified pressure can be adjusted to set the forming load of the lower punch 169 at about the bottom dead center, and excessively voluminous material can be formed without damaging the dies.

In this case, at the end of forming once, portion of the hydraulic operating fluid in the cylinder chamber 179 is discharged outside through the relief valve 193 to move the press slide upward. And by the time the next forming starts, the hydraulic operating fluid is supplied into the cylinder chamber 179 by the hydraulic fluid supplying device 189 to fill the cylinder chambers 179, 181 to a prescribed amount with the hydraulic operating fluid.

In addition, in the forming machine structured as described above, almost all of the components of the forming machine can be accommodated in the die set, making the entire size to be very small. Therefore, it is very easy to replace or maintain the upper and lower dies 153, 155 and the upper and lower punches 161, 169, etc., allowing the replacement of the entire machine in a short time.

i 1 1 It is also very easy to attach or detach the pins 177 of the two-part piston members 176 to or from the holder 171, and these pins 177 can be disposed differently to easily vary the ratio71 of the closing force and the forming load (lower punch load). Thus, the present machine is superior in flexibility to produce many various formed products.

This is to say that the ratio is determined by the used number n of the pins 177 and can be easily varied by changing the used number n of the pins 177.

In the embodiment described above, as shown in Fig. 5, the holder 171 is provided with 12 cylinder chambers 179, and the sectional area of each cylinder chamber 179 is a value obtained by dividing the sectional area of the cylinder chamber 181 accommodating the piston member 175 by 8.

Therefore, as in the embodiment described above, it becomes easy to make 7 to be 1 by using eight pins 177.

To make n to be 2, the cylinder chambers 179 are desirably disposed to face each other at an angle of 1200 and to set the n to 3, three cylinder chambers 179 are desirably disposed at an angle of 1200.

Fig. 8 shows the third embodiment of the forming - 19 01 machine of this invention, which is basically the same with the second embodiment. In this embodiment, two types of pins 177A, 177B different in length are used instead of the pins 177 consisting the two-part piston members 176.

The long pins 177A are designed to contact the die plate 167 at the beginning of forming and used in eight as shown in Fig. 9. Consequently, the value is 1 then.

The short pins 177B are designed to contact the die plate 167 on the way to forming and used in four as shown in Fig. 9. Consequently, when these pins 177B contact with the die plate 167, the value n is 1.5.

In this embodiment, a cavity 196 is formed in the upper die 153, and a formed product 200 having a flange 199 with an uneven-leveled part 199 is formed as shown in Fig. 10.

In the formed product 200 as shown in Fig. 10, it is desirable to vary the value from 1 to 1.5 on the way Q to forming as shown in Fig. 11, and this embodiment makes it possible to easily vary the value on the way Q to forming.

With the forming machine structured as described above, almost the same effect can be attained as by the embodiment shown in Fig. 4.

In the above embodiment, the piston member 175 is forced down by the spring 182, but this invention is not limited to such an embodiment. For example, the piston 0 1 i j 1 i 1 i member 175 may be energized by a hydraulic, pneumatic or any other cylinder.

Further, in the above embodiment, the formed product as shown in Fig. 10 is produced, but this invention is not limited to such an embodiment. For example, it becomes possible to easily form gears etc. by forming the cavity in the form of a gear or the like.

In the above embodiment. the die plate 167 is disposed below the lower die 155. But this invention is not limited to such an embodiment. For example, the machine may be designed upside down to dispose the die plate 167 on the slide side, and the dies may be horizontally disposed to face each other.

As many apparently widely different embodiments of thi invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except that as defined in the appended claims.

Claims

What is claimed is:

1. A forming machine consisting of inserting a punch into at least one of a pair of dies disposed to face each other, supporting the die accommodating the punch by one side of a ring member accommodated in a holder, and disposing the other side of the ring member within a cylinder chamber formed within said holder, characterized by disposing a piston member within the ring member, supporting said punch by one end of the piston member, and disposing the other end of the piston member within the cylinder chamber formed within the holder or a cylinder chamber communicated with the holder.

2. A forming machine comprising a pair of dies disposed to face each other, a punch to be inserted in at least one of the above dies, a die plate to support the die in which the punch is inserted, a holder disposed opposite to the die of the die plate, a piston member to support the punch disposed at the center of the holder, a plurality of two-part piston members to support the die plate disposed outside of the piston member of the holder, and a communication path communicating the cylinder chamber accommodating the piston member with the cylinder chamber accommodating the two-part piston member.

1

3. A forming machine substantially as hereinbefore described with reference to Figures 1 to 13 and 15 of the accompanying drawings.

Published 1991 atThe Patent Office, State House. 66/71 High Holborn. London WC I R 41P. Further copies may be Obtained frorn Mes Branch. Unit 6. Nine Mile Point Cwmfelinfach, Cross Keys. Newport. NPI 7HZ. Printed by Multiplex techniques ltd, St Mary Cray. Kent-