JP3317087B2 - Pressing method and apparatus for plate material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for pressing a sheet material.

In particular, drawing, overhanging, bending,
Alternatively, it is a processing method and apparatus provided for the combined processing.

[0003]

2. Description of the Related Art In the forming of sheet materials, press working is a frequent processing method, and is used for forming a large number of parts from small parts such as automobile parts, containers and household appliances parts to large parts such as automobile inner and outer plates, sinks, bathtubs and the like. Have been applied.

FIG. 13 shows a conventional ordinary press working method. In FIG. 13, 1 is a punch, 2 is a die, 3
Wrinkle holding plate (hereinafter collectively referred to as mold)
Reference numeral 4 denotes a plate material to be processed, and press working is performed by pressing the punch 1 in a state in which the plate material 4 to be processed is held by the die 2 as a die 2 with a predetermined force. However, in press working, wrinkling and breakage often cause problems as defects.

[0005] The wrinkle problem occurs in the drawn portion, and the countermeasure is to use the die 2 in the flange portion of the drawn portion.
It is effective to hold the workpiece plate 4 with a high clamping force by the wrinkle holding plate 3. However, increasing the clamping force inevitably causes an increase in the frictional force between the die and the wrinkle holding plate, hinders smooth inflow of the plate material to be processed between the die and the wrinkle holding plate, and eventually breaks. is there.

[0006] Breakage occurs in the draw-formed portion and the stretch-formed portion, and this measure is taken by reducing the frictional force between the die 2 and the wrinkle holding plate 3 and the plate material 4 to be processed in the draw-formed portion. In the overhang forming section, it is effective to reduce the frictional force between the punch 1 and the plate material 4 so that the plate material can easily flow out from the bottom of the punch. is there.

One method of reducing the frictional force between the plate material to be processed and these dies is to use a highly lubricated press oil. However, when the frictional force is reduced by using a press oil or the like having good lubricity, wrinkles are liable to occur, although it is effective for breaking.

As described above, in press working, it is difficult to avoid wrinkles and breakage at the same time. Especially in the pressing of complicated shapes, the flow of the plate material to be processed differs depending on the part of the molded product, so breaks easily occur in parts that do not easily flow, and shape defects such as wrinkles and surface distortion occur in the parts that easily flow The situation is that it is becoming easier to take measures.

Furthermore, the use of a highly lubricated press oil not only increases the number of oiling steps, but also often results in poor cleanability, making degreasing difficult.

[0010] In order to solve these problems, the inventor of the present invention provided a die and a wrinkle holding device through a liquid discharge port provided on a die or a wrinkle holding plate or both as shown in FIGS. 14, 15 and 16 below. Japanese Patent Application No. 5-2 discloses a method of performing drawing while supplying a pressurized liquid to a plate material to be processed sandwiched between the plates.
93150.

FIG. 14 is a plan view showing a connection between a die and a liquid supply device when a rectangular cylinder is formed while supplying liquid to a plurality of liquid discharge ports from two liquid supply devices.

FIG. 15 is a bottom view showing the connection between the wrinkle holding plate and the liquid supply device when a rectangular tube is formed while supplying the liquid from one liquid supply device to a plurality of liquid discharge ports.

FIG. 16 is a system diagram of a liquid supply means in the case where a rectangular cylinder is formed using a double action press while supplying liquid to a plurality of liquid discharge ports from two liquid supply devices.

In FIGS. 14, 15 and 16, 5a to 5l are liquid discharge ports, 6a to 6l are liquid supply holes, 20a to 20d are liquid supply pipes, and 30a to 30d are liquid supply pumps.

FIG. 14 shows four liquid discharge ports 5 in the die 2a.
a, 5b, 5c, and 5d are provided, and two liquid discharge ports are respectively provided with a liquid supply pipe 20a, 20b and a liquid supply device including liquid supply pumps 30a, 30b.

In FIG. 15, the wrinkle holding plate 3a is provided with one liquid supply pipe 20c for four liquid discharge ports 5e, 5f, 5g, and 5h, and a liquid supply device including a liquid supply pump 30c.

The apparatus shown in FIG. 16 includes the wrinkle holding plate 3 shown in FIG.
a, and the four liquid discharge ports 5i, 5j, and 4d on the die 2a side as in FIG.
5k and 5l are provided, and a liquid supply device including a liquid supply pipe 20d and a liquid supply pump 30d is provided for the liquid discharge port.

Further, as shown in FIG. 17 and FIG. 18 below, a method of performing overhanging processing while supplying a pressurized liquid between a punch and a workpiece through a liquid discharge port provided in the punch 1a is disclosed in Japanese Patent Application No. 2002-110,086. It was proposed as Hei 5-293151.

FIG. 17 is a plan view showing the connection between a punch and a liquid supply device when molding is performed while supplying liquid from a single liquid supply device to a plurality of liquid discharge ports.

FIG. 18 is a system diagram of the liquid supply means in the case of performing stretch forming using a double action press machine while supplying liquid to a plurality of liquid discharge ports from three liquid supply devices.

In FIG. 17, five liquid discharge ports 5 are provided on the punch 1a.
m, 5n, 5o, 5p, and 5q are provided, and one system of liquid supply devices 20e and 30e is provided for the liquid discharge ports.

The punch 1 shown in FIG.
a for liquid outlets 5m, 5n, 5o, 5p, 5q
System liquid supply device, and each liquid discharge port 5r, 5s, 5t, 5u, 5v, 5w, 5x, of die 2a and wrinkle holding plate 3a.
For 5y, two systems of liquid supply devices including liquid supply pipes 20f and 20g and liquid supply pumps 30f and 30g are provided. In addition, 40a and 40b are die cushion pins.

[0023]

[Problems to be solved by the invention]
The techniques disclosed in Japanese Patent Application No. 93150 and Japanese Patent Application No. 5-293151 are excellent in avoiding wrinkles and breakage at the same time, and various press workings were attempted using these techniques.

At this time, with the method disclosed in the above-mentioned prior application, there was a case where a stable result could not be obtained by all the press workings.

In general, the contact pressure between the plate material to be processed and the mold differs depending on the part of the molded product. If liquid is supplied to the liquid discharge ports of a plurality of parts having different contact pressures by only one system of liquid supply device, The liquid flows out of the liquid discharge port at the lowest contact pressure at a low pressure stage.

For this reason, no further increase in the liquid pressure occurs, and no liquid flows out from the liquid discharge port provided at a portion having a higher contact pressure to the vicinity of the liquid discharge port. In some cases, it was not sufficiently exhibited.

That is, the upper limit of the pressure of the liquid supply system is defined by the portion having the lowest contact pressure. In the portion having the higher contact pressure, the required hydraulic pressure is required although the higher hydraulic pressure is required. It becomes impossible to give.

The present invention relates to such a press working method and apparatus, in which a pressed part of any shape is used.
An object of the present invention is to provide a method and an apparatus for press-working a sheet material, which can surely exert the effect of suppressing breakage and wrinkles and have extremely excellent workability.

[0029]

The above object is achieved by the following means.

According to a first aspect of the present invention, a press is applied while supplying a pressurized liquid at a pressure that overcomes the contact pressure with the plate material from a plurality of liquid discharge ports provided between at least one of a die, a wrinkle holding plate, and a punch and the plate material. And a press working method for a plate material. As a preferable example of the method of supplying the pressurized liquid at a pressure that overcomes the contact pressure with the plate material, a method of supplying the pressurized liquid at an independent pressure (a pressure higher than the maximum value of the contact pressure with the plate material) for each discharge port of the pressurized liquid is preferable. A method of supplying a liquid is considered. As a more preferable example, an example in which a fixed amount of the pressurized liquid is supplied to each pressurized liquid discharge port regardless of the contact pressure with the plate material.

According to a second aspect of the present invention, a plurality of liquid discharge ports are provided in at least one of a die, a wrinkle holding plate, and a punch.
A press working apparatus for a plate material, comprising a liquid supply means for supplying a pressurized liquid at a pressure that overcomes a contact pressure with the plate material. As a preferable example of the liquid supply means, a pump independently provided for each liquid discharge port can be considered. The pump is preferably a fixed-rate pump, but is not necessarily a fixed-pump as long as it has a discharge pressure higher than the maximum value of the contact pressure with the plate material. In addition, with a common pump, a constant flow valve or a pressure reducing valve (set pressure is
The pressure may be higher than the maximum value of the contact pressure with the plate material).

The third invention is characterized in that, in addition to the second invention, a liquid pool connected to a liquid discharge port is provided at a position corresponding to a risk of breakage of a die or a wrinkle holding plate or a molded product flange of both of them. Is a press working apparatus for a plate material.

[0033]

According to the present invention, the pressurized liquid is supplied from a plurality of liquid discharge ports provided between at least one of the die, the wrinkle holding plate, and the punch and the plate at a pressure that overcomes the contact pressure with the plate. Even if the liquid flows out at a low pressure stage from the liquid discharge port at the lowest contact pressure, it does not affect the pressure of the pressurized liquid at the other liquid discharge ports. Therefore, since the pressurized liquid flows out from any liquid discharge port, lubrication is completely performed. Therefore, occurrence of breakage and wrinkles can be avoided.

In the drawing process, the pressurized liquid can be supplied to a plurality of contact portions between the plate material to be processed and the mold at a pressure that overcomes the contact pressure in any shape processing. A pressurized liquid is constantly supplied to significantly reduce the frictional force between each surface of the plate material to be processed and the die, the plate material to be processed and the presser plate, or the surfaces of the plate material to be processed and the punch, thereby avoiding breakage.

In the overhanging process, the press working is performed by supplying the pressurized liquid from the liquid discharge port provided in the punch with a pressure that overcomes the contact pressure of the contact portion between the punch and the plate material to be processed. Liquid is supplied, the frictional force between the punch and the plate material to be processed is reduced, and the portion of the plate material to be processed, which was located at the bottom of the punch at the initial stage of molding, flows out to the wall through the shoulder of the punch in the forming process. As a result, the outflow of the plate material becomes uniform over the entire punch, the distortion of the wall portion is reduced, and the occurrence of breakage is avoided.

Regarding the suppression of wrinkles, in any shape drawing, press working is always performed by supplying pressurized liquid at a pressure that overcomes the contact pressure to a plurality of wrinkle generating portions of the flange portion. The pressurized liquid is supplied, and the plate material to be processed at each wrinkle generating part receives uniform surface pressure between the die or the wrinkle pressing plate or both the die and the wrinkle pressing plate, and the forming proceeds to avoid wrinkles I do.

The reason why a liquid pool connected to the liquid discharge port is provided at a position corresponding to the risk of breakage of the molded product flange portion of the die and / or the wrinkle holding plate is as follows.

When drawing is performed by this apparatus, since the pressurized liquid intervenes in the breakage danger portion throughout the forming process, the frictional force between each surface of the plate material to be processed and the die or the plate material to be processed and the wrinkle holding plate is remarkable. Reduce and avoid breakage.

A liquid pool may be provided in accordance with the non-uniform increase in the thickness of the flange portion of the molded product generated in the drawing process, and the liquid between the surface of the plate material to be processed and the die or the workpiece and the wrinkle holding plate may be provided. Since the pressurized liquid continues to intervene throughout the forming process, the frictional force between each surface of the plate material to be processed and the die or the plate material to be processed and the wrinkle holding plate is remarkably reduced, and the occurrence of breakage is avoided.

Regarding the suppression of wrinkles, a pressurized liquid is supplied from a liquid pool provided on a die or a wrinkle holding plate or both to a plate material to be processed, so that the liquid can be formed in any shape by drawing. Through the process
Liquid intervenes.

For this reason, the forming proceeds while the plate material to be processed receives a uniform surface pressure between the die or the wrinkle holding plate or both the die and the wrinkle holding plate. By this action, the wrinkle holding force is substantially increased, and the generation of wrinkles is avoided drastically as compared with a case where the workpiece is simply clamped by the die and the wrinkle holding plate.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic principle of the present invention is to perform pressing while supplying a pressurized liquid between one or more of a die, a wrinkle holding plate, and a punch and a plate with a pressure that overcomes the contact pressure with the plate. The pressurized liquid is sufficiently effective even when the present invention is applied to each of the die, the wrinkle holding plate and the punch independently, but is supplied from all of the punch, the die and the wrinkle holding plate in more severe press working.

Basic matters to be considered in implementing the present invention will be described. When performing press working in consideration of equipment cost, production cost, and effect, the present invention is applied to a die or a wrinkle holding plate or both at a draw forming part in a press work in which draw forming is dominant or a complicated shape press work. It is effective to apply

Further, it is effective to apply the present invention to a punch in a stretch forming portion in press working in which stretch forming is dominant or in press working of a complicated shape.

In the method of performing the press while supplying the pressurized liquid, specifically, the supply time of the pressurized liquid is usually immediately after the work material is sandwiched between the die and the wrinkle holding plate.
It may be added before clamping, or supplied at a time immediately before molding proceeds to some extent and wrinkles or breakage starts to occur.

The liquid supply means may be any device having a function of controlling the pressure of the liquid at each liquid discharge port and the addition timing, and the details of the mechanism are not limited.

The liquid supply means is constituted by a pressure supply means such as a liquid supply hole, a liquid supply pipe and a liquid supply pump. The liquid supply hole, liquid supply pipe and liquid supply pump are
What is necessary is just the arrangement of a system.

The higher the pressure of the liquid to be supplied, the better, but a clear effect is usually obtained at 2 MPa or more for wrinkles and 5 MPa or more for breakage. The apparatus may be a device capable of appropriately selecting and adjusting the liquid pressure according to the degree of difficulty of molding or the state of occurrence of a failure, such as pump capacity, connection switching of piping, and a pressure adjusting valve.

The upper limit of the pressure is determined by the mold, liquid supply piping,
Considering the practical strength of the liquid supply means such as a liquid supply pump, it is usually 50 MPa or less.In order to protect the equipment, a relief valve, a pressure reducing valve, etc. may be installed and used to set the pressure. It is possible.

It is not necessary to specify the type of the liquid, but it does not cause problems such as corrosion and clogging in the liquid supply path, and does not cause corrosion or degreasing of parts after pressing. Any type is acceptable.

Hereinafter, the embodiment will be described in detail. (Embodiment 1) A first embodiment according to the present invention is an apparatus configuration for forming a square tube mainly by drawing, and a press process for forming a square tube using the apparatus. , FIG. 3,
FIG. 4 is a diagram of the apparatus configuration, Table 1 shows hydraulic conditions, and FIG. 5 shows press conditions and results.

FIG. 1 is a plan view showing a connection state between the die and the liquid supply device, and FIG. 2 is a bottom view showing a connection state between the wrinkle holding plate and the liquid supply device. On the other hand, an independent liquid supply hole, a liquid supply pipe, and a liquid supply pump are provided for each one system.

In FIGS. 1 and 2, 2a denotes a die, 3
a is a wrinkle holding plate, 5a to 5h are liquid discharge ports, 6a to 6h are liquid supply holes, 10a to 10d are liquid supply pipes, 30
Reference numerals h to 30o denote liquid supply pumps.

FIG. 3 is a system diagram of the liquid supply means in the double action press machine, in which an independent liquid supply hole, a liquid supply pipe and a liquid supply pump are provided for each liquid discharge port. I have.

When performing drawing by such an apparatus, the workpiece 4 is placed on the die 2a, pressed and clamped by the wrinkle holding plate 3a, and then the punch 1a is lowered. When processing, the liquid supply pumps 30h, 30
i, 30j, 30k, 30l, 30m, 30n, 30o
Pressurized liquid by eight pumps, etc.
a, 10c, 10e, 10g, etc., through eight liquid supply pipes, liquid supply holes 6a, 6c, 6e, 6g, etc. provided in the die 2a or the wrinkle holding plate 3a.
After passing through c, 5e, 5g, etc., the material is supplied to the portion of the workpiece 4 sandwiched between the die 2a and the wrinkle holding plate 3a.

For each liquid discharge port 5, an independent liquid supply hole 6,
Since each of the liquid supply pipe 10 and the liquid supply pump 30 is provided one by one, the work to be processed in each part caused by the finish of the mold, the accuracy of the press machine, the uneven thickness distribution generated in the molding process, and the like. It is possible to avoid the phenomenon that the fluid pressure is insufficiently increased due to the uneven contact pressure between the material 4 and the mold, and it is possible to reliably suppress wrinkles and avoid breakage.

FIG. 4 is a system diagram of the liquid supply means in the single action press machine. Independent liquid supply holes, liquid supply pipes and liquid supply pumps are provided for each liquid discharge port. I have.

As described above, the present invention can be applied to any press machine capable of drawing.

Although the present invention can be applied to any material as long as it is a material to be subjected to drawing, an embodiment applied to a cold-rolled steel sheet will be described below.

FIG. 5 is a diagram showing the results of a square tube forming test.
Using Example 1 of the combination shown in FIG. 2 and FIG. 3, the apparatus of FIG. 16 as Comparative Example 1, and the apparatus of FIG. 13 as Comparative Example 2, processing a 200 mm × 200 mm SPCE material having a thickness of 0.7 mm. This is a result of performing a square tube forming test of a material having a size of 100 mm x 100 mm and a forming height of 40 mm while changing the supply state of the liquid.

In Comparative Example 1, the four liquid discharge ports 5e, 5g, 5i and 5k shown in FIG. 16 were formed by a device capable of supplying a liquid by branching off from one system of liquid supply device.

Comparative Example 2 was an apparatus shown in FIG. 13, in which a normal rectangular cylinder was formed by pressurizing rust-proof oil lubrication.

The relationship between the liquid supply set pressure and the maximum attained liquid pressure during actual press working is as shown in Table 1.

[0064]

[Table 1]

In the case of the first embodiment, the actual maximum attained hydraulic pressure differs for each of the four liquid supply systems.
This is because there is a difference in the contact pressure between the molded articles a and 3a.

The reason why the highest ultimate pressure of the wrinkle holding plate 2a is the lowest is that the contact pressure between the wrinkle holding plate 2a and the plate material 4 to be processed is small.

On the other hand, in the case of the comparative example 1, the maximum pressure reached the lower limit of the maximum pressure of the example 1, but this is the lower limit of the contact pressure between the workpiece 4 and the molds 2a, 3a. This is because the liquid flows out from the liquid discharge port 5.

The evaluation was performed on wrinkles, breaks, and processing flaws generated at corners when molding was performed with various wrinkle pressing forces.

In the case of the normal molding of Comparative Example 2, wrinkles are generated with a low wrinkle pressing force. To avoid this, if the wrinkle pressing force is increased, breakage occurs, and processing flaws are generated on the corner portion drawn wall. You can see that it is doing. All of these result in product defects. That is, there is no processing condition for obtaining a product which avoids all these problems at the same time in the ordinary molding method.

A method of working while supplying a pressurized liquid to a work material held between a die and a wrinkle holding plate,
In the case where the liquid is supplied only from the wrinkle holding plate, and in the case where the liquid is supplied by branching from the single system supply device of Comparative Example 1, the wrinkle and breakage are prevented by setting the wrinkle holding force to 20 kN or more and 50 kN or less. I could avoid it.

On the other hand, when the liquid was supplied only from the wrinkle holding plate of Example 1, the processing flaw was the same, but the wrinkle holding force could be expanded to 20 kN or more and 80 kN or less, and wrinkles and breakage could be avoided.

In the case where the liquid is supplied only from the die, in Comparative Example 1, a good product having a wrinkle pressing force of 20 kN or more and 90 kN or less, which does not generate any wrinkles, breakage, or processing scratches on the corner portion drawn wall, is obtained. Was.

In the first embodiment, the wrinkle holding force is set to 20 kN or more and 150 kN.
A very good product which can be expanded to the range of N or less and does not generate any of wrinkles, breaks, and processing scratches on the corner drawn wall was obtained.

When the liquid is supplied from both the die and the wrinkle holding plate, the comparative example 1 has a wrinkle holding force of 20 kN or more.
By setting the pressure to 125 kN or less, a good product free of wrinkles, breakage and processing scratches on the corner part drawn wall was obtained.

In the first embodiment, the wrinkle holding force is 20 kN or more and 170 kN.
A very good product which could be enlarged to the following and did not generate any of wrinkles, breaks, and processing scratches on the corner part drawn wall was obtained.

In addition, according to the present invention, the workpiece and the die,
Or, when the pressurized liquid is supplied between the die and the wrinkle holding plate, even if it is applied to a material that easily causes scratches on the product surface by drawing, such as a surface-treated steel sheet, pre-coated material, aluminum alloy material, tin, etc. Scratches can be significantly reduced.

Further, even when the surface of the sheet material has a concentrated layer or a passivation layer having excellent corrosion resistance, heat resistance, resistance to flowing-off into gas, aesthetics, etc., the surface layer can be formed with a punch, a die or a wrinkle holder. When the plate is easily damaged by processing, the damage can be reduced.

(Embodiment 2) In Embodiment 2 according to the present invention, a trapezoidal-shaped apparatus mainly comprising an overhanging process and a trapezoidal-shaped press working using the apparatus are shown in FIG. 8 and 9 are diagrams of the apparatus configuration, Table 2 is a table of hydraulic conditions, and FIG. 6 is a diagram showing pressing conditions and results.

FIG. 6 is a diagram showing the results of a trapezoid forming test, in which the plate thickness was 1.
A 0mm alloyed hot-dip galvanized steel sheet was used as the plate material 4 to be processed.
Is a result of a test in which the supply state of the liquid is changed.

In the second embodiment, the punch 1 shown in FIG.
b, a molding test was performed using the die 2b in FIG. 8 and a double action press as shown in FIG.

In Comparative Example 3, a die 2a and a plate 2 to be processed sandwiched between wrinkle holding plates 2a were used as devices.
Forming was performed using a device that supplies one system of liquid from the two liquid discharge ports 5 of the wrinkle holding plate 3a and a device that supplies one system of liquid from the three liquid discharge ports 5 of the punch 1a. .

In Comparative Example 4, the molding shown in FIG. 13 was carried out by ordinary molding using anti-rust oil lubrication. FIG. 7 is a bottom view showing the connection between the punch and the liquid pressure supply device, and FIG. 8 is a plan view showing the connection between the die and the liquid pressure supply device. One supply hole, one liquid supply pipe, and one liquid supply pump are provided.

FIG. 9 is a system diagram of a liquid supply means in a double action press machine. One liquid discharge port is provided with an independent liquid supply hole, a liquid supply pipe, and a liquid supply pump. I have.

The relationship between the liquid supply set pressure and the maximum attained liquid pressure during actual press working is as shown in Table 2.

[0085]

[Table 2]

In the case of the second embodiment, the reason why the actual maximum reached hydraulic pressure differs for each of the four supply systems is that the plate material 4 to be processed and the mold 1b,
This is because the contact pressure with 2b and 3b varies depending on the location of the molded product.

The reason why the highest ultimate pressure of the wrinkle holding plate 3b is the lowest is that the contact pressure between the wrinkle holding plate 3b and the plate material 4 to be processed is small.

The evaluation was performed on wrinkles and breaks generated at the corners when molding was performed with various wrinkle holding forces.

In the case of the normal molding of Comparative Example 4, wrinkles are generated with a low wrinkle pressing force, and in order to avoid this, breakage occurs when the wrinkle pressing force is increased. All of these result in product defects. That is, there is no processing condition for obtaining a product which avoids all these problems at the same time in the ordinary molding method.

In the case of supplying only the punches, when supplying the liquid by branching from the liquid supply device of one system of Comparative Example 3, a product having wrinkles and breakage of 40 kN or more and 90 kN or less was obtained.

On the other hand, in Example 2, pressing was possible with a wide range of wrinkle pressing force, and wrinkling and breakage could be avoided by setting the pressure to 40 kN or more and 110 kN or less.

In the case where the liquid was supplied from the die and the wrinkle pressing plate, in Comparative Example 3, a good product having a wrinkle pressing force of 20 kN or more and 40 kN or less and having neither wrinkles nor breakage was obtained.

On the other hand, in Example 2, pressing was possible with a wide range of wrinkle pressing force, and a very good product was obtained at 20 kN to 60 kN in which neither wrinkles nor breakage occurred.

In the case where the liquid is supplied from all of the die, the wrinkle holding plate and the punch, the comparative example 3 has the wrinkle holding force.
By setting the pressure to 20 kN or more and 100 kN or less, a good product without wrinkles or breakage was obtained.

In the second embodiment, the wrinkle holding force is increased from 20 kN to 140 kN.
A very good product which could be expanded to N or less and neither wrinkles nor breakage occurred was obtained.

Note that in FIG. 7, the 8
Is a liquid supply groove, which is a preferred embodiment of the present invention, for supplying liquid discharged from the liquid discharge port 5 to a wide area. This is desirably selected according to the shape of the processed product.

Further, in FIG. 8, 35 is provided on the die 2b.
Is a lock bead that restricts the inflow of the edge of the plate material 4 to be processed, and prevents the occurrence of beveling and distortion.

(Embodiment 3) In Embodiment 3 according to the present invention, an apparatus configuration for forming a square cylinder mainly using a drawing process in which a liquid pool is provided on a die, and a press process for forming a square cylinder using the apparatus. 10 is a diagram of the apparatus configuration, Table 3 shows the hydraulic conditions, and FIG. 12 shows the press conditions and the results.

FIG. 10 is a plan view of a liquid pressure supply device in which a liquid reservoir is provided on a die. A liquid reservoir 7 is provided around the liquid discharge port 5 of the die 2c. In addition, for one liquid discharge port,
One independent liquid supply hole, one liquid supply pipe, and one liquid supply pump are provided. The positional relationship with the liquid discharge port 5 may be continuous, but usually, a liquid discharge port should be provided inside the liquid pool 7.

However, the range and depth of the liquid pool is limited by a closed curved surface between the dies 2c, 3c and the plate material 4 in order to prevent the liquid from flowing out at a low pressure and to secure the pressurized liquid to the maximum plate thickness portion. It is important to configure

This liquid pool is a technique for interposing a liquid throughout the molding process, and is effective when used together with a technique for supplying a pressurized liquid according to the contact pressure.

The basic idea to be considered for the liquid pool 7 is that, when the case 1 is subjected to the drawing process of the plate material 4, the die 2 is located at a position corresponding to a breakage dangerous portion of the molded product flange portion in advance.
c or the wrinkle holding plate 3c or both of them is provided with a liquid discharge port 5 and a liquid pool 7 around the liquid discharge port having a depth at which the breakable portion does not contact the die or the wrinkle hold plate. The process is performed while supplying pressurized liquid from the liquid discharge port to the plate material to be processed held by the wrinkle holding plate.

When the case 2 is subjected to the drawing process of the plate material 4, the die 2c and / or the wrinkle holding plate 3c at a position corresponding to the increased thickness portion of the molded product flange portion are previously formed.
A liquid discharge port 5 and a liquid pool 7 having a depth such that a maximum thickness increasing portion does not contact the die or the wrinkle holding plate are provided around the liquid discharge port, and the liquid holding member 7 is sandwiched between the die and the wrinkle holding plate. Performing while supplying pressurized liquid to the processing plate material from the liquid discharge port.

When the case 3 is subjected to the drawing process of the plate material 4, the die 2c and / or the wrinkle holding plate 3c at a position corresponding to the increased thickness portion of the flange portion of the molded product in advance are provided.
The liquid discharge port 5 and the contour of the equal thickness distribution line shape near the maximum thickness increase portion around the liquid discharge port and a depth not less than (maximum thickness-thickness of the equal thickness curve portion). The method is to apply a pressurized liquid from a liquid discharge port to a plate material to be processed sandwiched between a die and a wrinkle holding plate in advance by applying a retained liquid pool 7.

FIG. 11 is a graph showing the thickness distribution of a portion sandwiched between a die and a blank holding plate of a plate material to be processed, which is 1/1 of the molded product.
4 is an enlarged partial view of the case of a normal die or a wrinkle holding plate. A zinc nickel-plated (die side) steel plate having a 0.8 mm-thick organic coating (punch side) having a thickness of 0.8 mm is punched at a size of 100 mm × 150 mm. In a normal mold not provided with the liquid discharge port 5 and the liquid supply hole 6, the molding height 35
The equivalent plate thickness curve of the flange portion of the rectangular tube molded product formed to a thickness of 0.99 mm, 0.88 mm, 0.87 mm, 0.
86mm.

The method of forming the thickness distribution shape of the molded product into the die at the end of molding of the flange portion is as follows. The thickness of the flange portion after drawing is measured, and the die 2c or the wrinkle holding plate 3c is corrected in accordance with the measured thickness. Or by measuring the equal thickness distribution shape of the flange portion after drawing, and obtaining a contour of the equal thickness distribution line shape near the maximum thickness increasing portion and (maximum thickness−
A liquid pool 7 having a depth equal to or greater than the thickness of the curved portion having an equal thickness is provided.

It is important that the liquid pool has a closed curved surface, that is, if the supplied liquid flows from the periphery at a low pressure without being supplied to the maximum thickness increasing portion, the effect is greatly reduced. is there. This is because it is not possible to achieve lubrication of the portion where the maximum thickness increases due to the most intense friction and lubrication toward the die shoulder R together with the movement of the plate material 4 during drawing (replenishment by applying pressure to this loss). It is.

Further, the pressurized liquid is sufficiently effective even if a liquid pool is applied to each of the die 2c and the wrinkle holding plate 3c alone, but in a more severe drawing process, both the die and the wrinkle holding plate 3c are used. It is preferable to supply from.

At this time, the increased plate thickness may be divided and corrected by the die 2c and the wrinkle pressing plate 3c. However, since it is necessary to make the two pressurizing pressures the same, complicated control is required.
Of the liquid pool 7 on the side and the liquid pool 7 on the wrinkle holding plate 3c.
It is preferable to supply the pressurized liquid by completely displacing the position.

When the liquid pool 7 is provided on one of the die 2c and the wrinkle holding plate 3c, it is installed on the die 2c side where friction with the workpiece 4 is more severe, and the wrinkle holding plate 3c side is
It is more preferable to supply the pressurized liquid directly from the liquid discharge port without providing a liquid pool at a position facing the liquid pool 7 provided on the die 2c via the workpiece 4. There are various methods for manufacturing the liquid pool 7.

A flange portion of a square tube molded product obtained by molding the above-described 0.8-mm-thick one-side organic-coated (punch-side) zinc-nickel-plated (die-side) steel plate to a molding height of 35 mm using a normal mold. It is important to obtain an equal thickness curve.

The depth of the liquid pool 7 is determined by using the thickness distribution as it is for processing the die 2c or the blank holding plate 3c (1). The difference between the maximum thickness and the original thickness (0.8 mm) is defined as the maximum depth. Case (2), the maximum plate thickness and the near plate thickness (0.8
(8 mm) There is a case (3) having a difference depth.

The outline (boundary) of the liquid pool 7 is inverted in case (1), and the outline is gentle. Case (2) may be performed using the equal thickness distribution curve or may be performed only at the boundary of increased thickness. In the case of an equal thickness distribution curve, this boundary may have a step, but it is preferable that the boundary be processed smoothly.

The case (3) is the narrowest, and has a range of the maximum plate thickness and an equal plate thickness curve (0.88 mm) in the vicinity thereof. In this case, a sufficient effect can be usually obtained.

The die 2c or the wrinkle holding plate 3c before processing the liquid pool 7 is manufactured by testing the plate material 4 coated with high lubricating oil or polyethylene with the drawing device shown in FIG. The liquid pool 7 may be provided by subjecting the product to reworking and reworking, by measuring the thickness distribution of the flange portion of the molded product and modifying the mold.

Although the increasing tendency of the plate thickness differs depending on the drawing process conditions such as the plate material 7 to be processed, the shape and dimensions, the forming height, etc. Good thing.

FIG. 12 is a diagram showing the results of a square tube forming test using a single-sided organic-coated zinc-nickel steel plate as a work plate. The liquid supply of Example 3 of the present invention having a liquid pool and the liquid supply of one system of Comparative Example 5 are shown. When supplying liquid to multiple liquid discharge ports from the device,
5 shows the results of normal molding of Comparative Example 6.

The conditions such as the molding height in the square tube forming test are the same as those in FIG. 11. Example 3 shows the results of a square tube forming test with a forming height of 35 mm using the liquid pool shown in FIG. In the figure, only the die 2c side is based on the result of FIG. 11 (3)
Was added.

In the comparative example 5, the liquid pool 7 can be supplied to the four liquid discharge ports 5e, 5g, 5i, and 5k shown in FIG. Was molded using an apparatus provided with.

Comparative Example 6 is an apparatus shown in FIG. 13, which is a normal square cylinder molding by rust-proof oil lubrication. Liquid supply set pressure,
Table 3 shows the relationship between the ultimate hydraulic pressures at the time of actual press working.

[0121]

[Table 3]

The evaluation was performed on wrinkles and breaks generated at corners when molding was performed with various wrinkle holding forces.

In the case of the normal molding of Comparative Example 6, wrinkles were generated with a low wrinkle pressing force, and breakage occurred when the wrinkle pressing force was increased to prevent this.

When water was added from both the die and the wrinkle holding plate, the comparative example 5 had a wrinkle holding force of 20 kN or more and 15 kN or more.
By setting the pressure to 0 kN or less, a good product free of wrinkles and breaks was obtained.

In the case of Example 3, the wrinkle pressing force could be expanded to 20 kN or more and 180 kN or less using water, and a very good product without wrinkles or breakage was obtained.

The present invention can be applied to a general-purpose press having no special function, and does not impair the productivity. In addition, the oiling step on the workpiece before molding can be omitted, and even the degreasing step after molding can be omitted depending on the selection of the liquid to be used, and the production efficiency and workability can be significantly improved compared to the conventional case. .

[0127]

As described above, according to the method and the apparatus of the present invention, wrinkles and breaks can be avoided at the same time without impairing production efficiency by using a general-purpose press machine, and friction at only a necessary portion is reduced. The force can be selectively reduced, and the press workability of the plate material can be dramatically improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a connection between a die and a hydraulic pressure supply device when a rectangular tube is formed according to a first embodiment of the present invention.

FIG. 2 is a bottom view showing a connection between a wrinkle holding plate and a hydraulic pressure supply device when a square tube is formed according to the first embodiment of the present invention.

FIG. 3 is a system diagram of a liquid supply unit for forming a rectangular cylinder when performing press working using the double action press machine according to the first embodiment of the present invention.

FIG. 4 is a system diagram of a liquid supply unit when performing press working using the single action press machine of the present invention.

FIG. 5 is a first embodiment of the present invention in which a SPCE material is used as a plate material to be processed;
In the case where the liquid was supplied from one liquid supply device of Comparative Example 1 to a plurality of liquid discharge ports, and the normal molding of Comparative Example 2 was performed.
It is a figure which shows the square tube forming test result of 0 mm x 100 mm.

FIG. 6 shows a case where liquid is supplied to a plurality of liquid discharge ports from a single system of liquid supply device of Example 2 and Comparative Example 3 using an alloyed hot-dip galvanized steel sheet as a plate material to be processed, and Comparative Example 4 It is a figure which shows the trapezoid formation type test result which performed normal shaping | molding.

FIG. 7 is a bottom view showing a connection between a punch and a liquid pressure supply device when performing a trapezoidal forming according to a second embodiment of the present invention.

FIG. 8 is a plan view showing a connection between a die and a hydraulic pressure supply device when performing a trapezoidal forming according to a second embodiment of the present invention.

FIG. 9 is a system diagram of a liquid supply means for overhanging when press molding is performed using the double action press according to the second embodiment of the present invention.

FIG. 10 is a plan view of a hydraulic pressure supply device in which a liquid reservoir is provided on a die when forming a square tube according to a third embodiment of the present invention.

FIG. 11 is a diagram showing an example of a plate thickness distribution of a portion of a molded product using a normal die or a wrinkle holding plate, which is sandwiched between the die of the plate material to be processed and the wrinkle holding plate.

FIG. 12 shows a case where a liquid is added to a plurality of liquid discharge ports from one system of a liquid supply device of Comparative Example 5 in the case of Example 3 in which a single-sided organic-coated zinc-nickel steel plate is used as a plate material to be processed and a liquid reservoir is provided. It is a figure which shows the square cylinder molding test result which performed normal molding of Example 6.

FIG. 13 is a cross-sectional view showing a state immediately before processing when a conventional normal press processing method is performed.

FIG. 14 is a plan view showing a connection between a die and a liquid pressure supply device in the case of performing square tube forming while supplying liquid to a plurality of liquid discharge ports from the two liquid supply devices of the prior application.

FIG. 15 is a bottom view showing a connection between a wrinkle holding plate and a liquid pressure supply device when forming a rectangular tube while supplying liquid to a plurality of liquid discharge ports from one system of liquid supply device of the prior application.

FIG. 16 is a system diagram of a liquid supply unit in a case where a rectangular cylinder is formed using a double action press while supplying liquid to a plurality of liquid discharge ports from the two liquid supply devices of the prior application.

FIG. 17 is a plan view showing a connection between a punch and a liquid pressure supply device when molding is performed while supplying liquid to a plurality of liquid discharge ports from a single system of liquid supply device of the prior application.

FIG. 18 is a system diagram of a liquid supply unit when performing press working using a double action press machine while supplying liquid to a plurality of liquid discharge ports from the three liquid supply devices of the prior application.

[Explanation of symbols]

 1, 1a, 1b Punch 2, 2a, 2b, 2c Die 3, 3a, 3b Wrinkle holding plate 4 Worked plate material 5a to 5y, 5a to 5l Liquid discharge port 6a to 6y, 6a to 6l Liquid supply hole 7 Liquid pool 8 Liquid supply groove 10a-10s, 20a-20g Liquid supply pipe 30a-30z Liquid supply pump 35 Lock bead 40a-40d Die cushion pin

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B21D 22/20 B21D 22/22 B21D 24/00 B21D 24/04 B21D 24/08

Claims (3)

(57) [Claims] 1. A plurality of liquid discharge ports provided between at least one of a die, a wrinkle holding plate, and a punch and a plate material, each liquid discharge port being provided with a plurality of liquid discharge ports.
Press-forming method of the sheet material and performing pressurized liquid the pressure is controlled, the press while subjecting the sheet at a pressure to overcome the contact pressure between the plate material. 2. A die, blank holder plate, a plurality of liquid discharge ports to one or more punch provided for each liquid discharge port, the liquid discharge
The pressurized liquid the pressure is controlled for each mouth, pressing apparatus of the plate material, characterized in that a liquid supply means for supply feed at a pressure to overcome the contact pressure between the plate member. 3. A plate material according to claim 2, wherein a liquid pool connected to the liquid discharge port is provided at a position corresponding to a risk of breakage of the die or the wrinkle holding plate or a molded product flange of both of them. Press working equipment.