JP3509237B2 - Press forming method of aluminum 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 for press-forming a material such as aluminum or an aluminum alloy plate, and more specifically, to a low temperature range of the material by a refrigerant such as liquid nitrogen or liquid helium. The present invention relates to a molding method for cooling and performing molding while the material is in a low temperature range.

[0002]

2. Description of the Related Art When forming a material such as an aluminum or aluminum alloy plate, when the material is cooled to a low temperature range of, for example, -50 ° C. to -196 ° C. by a refrigerant, and the forming process is performed in the low temperature range, It is known that formability is improved to the same level as steel sheets.

For example, as a prior art, the forming process is carried out by cooling the material of the aluminum or aluminum alloy plate to a low temperature range (-50 ° C to -196 ° C) with a refrigerant, for example, JP-A-4-30.
No. 0032 (hereinafter referred to as Prior Art Example 1), JP-A-6-474.
55 (the prior example 2) and JP-A-5-253625 (the prior example 3).

In the prior art example 1, the material of the aluminum alloy plate is coated with a liquid lubricating oil that becomes a wax at an extremely low temperature, then immersed in liquid nitrogen and cooled to a low temperature range, and the material is taken out of the liquid nitrogen. After that, a technique of performing press molding within 15 to 45 seconds is disclosed.

In the prior art example 2, after applying the lubricating oil to the material of the aluminum plate and immersing it in liquid nitrogen and cooling it to a low temperature range to solidify the lubricating oil, the material is taken out of the liquid nitrogen and set in a press machine. When the die is brought into contact with the lubricating oil during the molding process, since the die is at room temperature, a part of the lubricating oil is liquefied, and the liquefied lubricating oil and the solidified lubricating oil are layered to form a layer of the material. A technique of performing molding is disclosed.

In the prior art example 3, the material is -50 ° C to -196 ° C.
Control the temperature of the mold itself as well as -50 ℃
A technique is disclosed in which the molding process is controlled by controlling the temperature to ˜-196 ° C.

[0007]

When the material is coated with lubricating oil and cooled to a low temperature range and then the molding process is performed, the material is changed to the mold when the mold is at room temperature as in the above-mentioned first and second embodiments. If set, the temperature of the material may rise to -50 ° C or higher due to heat conduction from the mold, and good molding may not be performed.

[0008] That is, conventionally, it is not clear how the temperature of the raw material rises when the raw material is cooled to a low temperature range and is subjected to the forming processing, so that the proper processing conditions are not known. In some cases, the molding performance of the material in the low temperature range could not be sufficiently obtained.

When the temperature of the mold itself is controlled to -50 ° C. or lower as in the prior art example 3, the temperature of the material is -50.
Although the temperature does not exceed ℃, there is a problem that equipment cost increases because the mold itself is cooled.

[0010]

The present invention SUMMARY OF] has been made in view of the conventional problems described above, such as, the present invention is, after cooling the material A Rumini <br/> um or an aluminum alloy plate in the coolant When setting the material in a molding die at room temperature and engaging the upper and lower dies in the molding die to perform the molding process of the material, the larger the pressing force of the material by the upper and lower dies is, The time from sandwiching the material with the mold of the mold to the end of the molding process is shortened, and the upper and lower molds are the material
Material temperature when sandwiched and material temperature when molding is completed
The difference between the degrees is A Le <br/> Miniumu material press-forming method of performing molding to hold within 100 ° C.. Also,
Ming cold aluminum or aluminum alloy plate material
After cooling with a medium, set the material in the molding die at room temperature
Then, by engaging the upper and lower molds of the molding die,
When performing the molding process, the pressing force of the material by the upper and lower molds
The larger the size of the
To shorten the time from
From the time the material is sandwiched by the upper and lower molds, 0.5
A A aluminum material of the press-forming method to end the molding process within seconds. Further, the present invention, the A Ruminiu <br/> in beam material press-forming method, the temperature of the material during the setting of the material into the molding die -160 ° C. or less der Luer Le <br/> Miniumu This is a press forming method of a material .

[0011]

[Examples] A material for an aluminum or aluminum alloy plate is cooled to a low temperature range (-50 ° C to -196 ° C) with a refrigerant such as liquid nitrogen or liquid helium, and the temperature of the material is maintained in the above low temperature range for forming. It is known that the moldability is improved by performing, but when the material cooled in the low temperature range is set in the molding die and the upper and lower molds of the molding die are engaged with each other to perform the molding process, In some cases, sufficient molding performance could not be obtained in the low temperature range.

Therefore, an experiment was conducted to find out how the temperature of the material changes during the forming process of the material in the low temperature range.

That is, as shown in FIG. 2, the plate thickness is 1 mm.
After the material 1 of the aluminum alloy plate of 200 mm x 200 mm is immersed in the refrigerant and cooled to about -196 ° C, it is placed on the lower model 3 of the ring having the outer diameter of 285 mm and the inner diameter of 100 mm. The temperature change of the material 1 when pressure was applied by the upper mold model 5 having the same shape as 3 was measured.

To measure the temperature of the material 1, as shown in FIG. 3, a T-shaped groove 1G is formed near the end of the material 1, and a thermocouple 7 is set in the groove 1G. The raw material 1 was immersed in a refrigerant and cooled with the 7 attached.

After the raw material 1 is immersed in a cooling medium and cooled to about -196 ° C., the raw material 1 is taken out from the cooling medium and placed on the lower mold 3 at room temperature within a predetermined time to measure under various conditions. The results are shown in Fig. 1.

In FIG. 1, a measurement result A is a measurement result in a state where the material 1 is taken out from the refrigerant, simply placed on the lower model 3 at room temperature within a predetermined time and left as it is. As is clear from FIG. 1, the temperature when the material 1 is placed on the lower die model 3 is about −160 ° C., and the temperature rises proportionally with the passage of time, but the temperature rise is gentle. .

Similar to the measurement result A, the measurement result B is obtained by taking out the material 1 from the refrigerant and, within a predetermined time, the lower model 3 at room temperature.
The measurement results are obtained when the material 1 is sandwiched by the upper die model 5 and placed at 0.65 ton after being placed and set on the top. In this measurement result B, the upper model 5 is the material 1
The temperature of the material 1 suddenly increased at the same time when the material was inserted.

Measurement results C and D are measurement results when the material 1 is sandwiched by the upper model 5 and pressed at 2.7 tons and 6.5 tons.

As is clear from the above measurement results B, C, and D, when the material 1 is sandwiched by the upper model 5, the material 1
It can be seen that the temperature rise of is rapid. Therefore, when the temperature of the material 1 was measured 0.5 seconds after the upper model 5 caught the material 1, the measurement result B was 79 ° C. The measurement result C was 94 ° C., and the measurement result D was a temperature increase of about 100 ° C., and the results reached around −50 ° C. Also,
It was found that the larger the pressing force, the more rapid the temperature rise.

After the material 1 is sandwiched between the lower model and the upper model 5, the temperature rises to -50 ° C. or higher in 2 seconds after the material 1 is sandwiched, and it cannot be processed in a low temperature range. all right.

As a result of the above experiment, the temperature of the material 1 rises within a predetermined time until the material 1 is immersed in the coolant and cooled and then set on the lower die model 3, and the temperature of the material 1 is set at the time of the setting. It can be seen that the temperature is about -160 ° C.

Further, when the material 1 set on the lower model 3 at room temperature is sandwiched by the upper model 5 at the same temperature and pressed, the temperature is about 100 ° C. about 0.5 seconds after the sandwiching. It can be seen that the temperature rises and the temperature of material 1 approaches -50 ° C.

Therefore, in order to perform the forming process of the material 1 in the low temperature range of -50 ° C. or lower, the temperature of the material when the material 1 is sandwiched by the upper and lower molds of the forming die and the completion of the forming process. Molding is performed by keeping the temperature difference of the material within 100 ° C, in other words, molding is completed within 0.5 seconds after the material is sandwiched by the upper and lower molds. It is necessary to.

Based on the above-mentioned experiment, the die 11 in the usual molding die 9 as shown in FIG. 4 is mounted on the bolster in the crank press, and the blank holder 13 and the punch 15 are mounted in the vertically movable slide in the press. Then, after the material W after being immersed in a coolant and cooled to about -196 ° C. is set on the die 11 at room temperature, the blank holder 13 presses and fixes the material W, and then the punch 15 presses the material W on the die 11. Then, the molding process was performed.

At this time, the pressing of the material W by the punch 15 is slightly delayed as compared with the pressing and fixing of the material W by the blank holder 13, but the forming process is performed in 0.5 seconds after the material W is pressed and fixed by the blank holder 13. The crankshaft was rotated at high speed to complete the molding process. As a result, the moldability of the material was good, and the effect of low temperature molding was confirmed.

Further, as shown in FIG. 5, a single action press is used in such a manner that the vertical positional relationship among the die 11, the blank holder 13 and the punch 15 is reversed.
The same effect was obtained when the forming process was completed within 0.5 seconds after the blank W was pressed and fixed by the blank holder 13 and the die 11.

When the rotation of the crankshaft is slowed and it takes about 1 second or more from the contact of the punch 15 with the material to the end of the forming process, the formability is poor and the result predicted by the above experiment is obtained. It was

As can be understood from the above description,
When the temperature of the molding die is about room temperature, the material after being cooled by the refrigerant is quickly set on the lower mold, the temperature of the material is kept at about -160 ° C or lower, and the material is sandwiched by the upper and lower molds. When the material is incorporated, more accurately, the material can be formed in a low temperature range of -50 ° C or less by performing the forming process within approximately 0.5 seconds after the material is pressed and fixed by the blank holder. It is a thing.

That is, according to the present embodiment, the molding process is carried out by using the molding die at room temperature and keeping the material cooled to the cryogenic temperature (about -196 ° C) by the refrigerant in the low temperature range (-50 ° C or less). Can be done easily.

[0030]

As will be understood from the above description of the embodiments, according to the present invention , aluminum or aluminum is used.
After cooling the alloy plate material with a refrigerant, cool the material to room temperature.
Set in the mold and the upper and lower molds in the mold
When engaging and forming the material, the upper and lower molds
The greater the pressing force of the material by the
From the time when the material is inserted to the end of the molding process
When the material is sandwiched between the upper and lower molds to shorten the space
The difference between the temperature of the material and the temperature of the material at the end of molding is 100 ° C
A pre-made aluminum material that is held and molded within
Since it is a molding method, even if the temperature of the material rises sharply as the pressing force of the material by the upper and lower molds increases,
The molding process can be easily carried out while maintaining the temperature of the raw material at −50 ° C. or lower.

That is, according to the present invention, a molding die at room temperature is used to facilitate a molding process in which a material cooled to a cryogenic temperature of about -196 ° C. is kept in a low temperature range of −50 ° C. or lower. Is what you can do.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of measured values showing a change in temperature rise of a material when the material is sandwiched by upper and lower molds.

FIG. 2 is an explanatory diagram showing an outline of an experimental device.

FIG. 3 is an explanatory diagram showing attachment of a thermocouple to a material.

FIG. 4 is an explanatory diagram of a molding method using a molding die.

FIG. 5 is an explanatory diagram of a molding method using a molding die.

[Explanation of symbols]

1 material 11 die (lower mold) 15 Punch (upper mold)

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B21D 22/00-26/14

Claims (3)

(57) [Claims] 1. A material for forming an aluminum or aluminum alloy plate is cooled with a refrigerant, the material is set in a molding die at room temperature, and upper and lower dies of the molding die are engaged with each other to form the material. In doing so, the larger the pressure applied to the material by the upper and lower molds , the shorter the time from the sandwiching of the material by the upper and lower molds to the end of the molding process, and the sandwiching of the material by the upper and lower molds. Material temperature when
And keep the difference between the temperature of the material at the end of molding and within 100 ° C
A press forming method for an aluminum material, which comprises performing a forming process. 2. An aluminum or aluminum alloy plate
After cooling the material with a refrigerant, mold it at room temperature
, And engage the upper and lower molds in the molding
The material by the upper and lower molds when molding the material
The larger the pressing force of the
Shorter time from sandwiching to completion of molding process
Comb, when the material is sandwiched by the upper and lower molds
A press forming method for an aluminum material, characterized in that the forming process is completed within 0.5 seconds . 3. The method for press forming an aluminum material according to claim 1 or 2 , wherein the temperature of the material when the material is set in the molding die is −160 ° C. or lower. Press forming method.