JPH0747431A - Press forming die assembly and press forming method using this die assembly - Google Patents

Abstract

PURPOSE:To reduce spring-back of a mask spherical peripheral part in warm press forming of an invar mask, and to improve mask deformation yield strength after forming is completed. CONSTITUTION:This die assembly is constituted so that an air blowout port 8 is provided in a peripheral part of a punch 1 of a warm press die, warm air or air of a room temperature is fed therefrom, and a temperature of a mask stock plate 6 and a forming mask can be controlled. At the time of overhanging the mask spherical surface, a temperature of the mask stock plate 6 is raised enough before the die and the mask stock plate 6 come into contact with each other. Also, in a process in which the forming mask is allowed to ascend and taken out from a bottom dead center at the time of forming the mask, it is taken out by blowing out air of a room temperature from the air blowout port 8 and after forced cooling. In such a way, recessed deformation caused by spring-back in the periphery of the spherical part peculiar to the invar mask can be suppressed, and also, wrinkle deformation generated at the time of taking out the forming mask from the die can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die apparatus such as a warm press molding die, and a press molding method using this die.

[0002]

2. Description of the Related Art Recently, as a means for preventing color misregistration due to thermal expansion of a shadow mask of a color cathode ray tube, a shadow mask is made of Invar (36% Ni-F) having a small coefficient of thermal expansion.
e) is performed. Such Invar has a higher yield strength and a lower Young's modulus than conventionally used low carbon steel sheets, so spring back increases when cold-formed, making it difficult to make the shadow mask into a predetermined spherical shape. Met.

On the other hand, since the mechanical characteristics of Invar are temperature-dependent, by heating the temperature of the mold to 100 ° C. to 250 ° C. to raise the temperature of Invar, the yield strength at the time of processing is lowered and the formability is improved. A warm forming method has been used to improve and reduce springback.

FIG. 4 is a longitudinal sectional view showing the structure of a conventional warm press molding die. In the figure, 1 is a punch, 2 is a pad, 3 is a wrinkle retainer, 4 is a die, and a heating element 5 is provided inside each, and the mold is heated to 100 ° C. by a heating means such as a power source (not shown). It is configured so that it can be heated to 250 ° C.

Next, a method of forming a shadow mask using a conventional warm press molding die will be described. Figure 5
FIG. 11 is a view for explaining the press molding process. First, the shadow mask material plate 6 is placed on the die 4 in the mold in the state of FIG. Three
Moves down and clamps the peripheral portion of the shadow mask material plate 6 between the dies 4. Next, as shown in FIG. 6, the punch 1 descends to start the overhang forming of the spherical portion from the center of the shadow mask material plate 6, and then the punch 1 moves the shadow mask material plate 6 as shown in FIG. The pad 2 is pressure bonded to complete the overhang molding of the spherical portion. Next, as shown in FIG. 8, the wrinkle retainer 3 escapes to the upper part to release the clamp in the peripheral portion of the shadow mask material plate 6, and then, as shown in FIG. And the mask skirt 6a is formed between the punch 1 and the die 4. Next, as shown in FIG. 10, the punch 1 moves up,
Then, the wrinkle retainer 3 rises, and finally the pad 2 rises as shown in FIG. 11, the molding mask 7 is pushed out from the die 4, and the shadow mask molding process is completed.

[0006]

In the conventional warm press die and the press forming method using this die, the punch 1 and the pad 2 are in the state of FIG. 5 before the step of projecting the spherical portion is started. Is not in contact with the shadow mask material plate 6, and the peripheral portion of the shadow mask material plate 6 does not contact the punch 1 and the pad 2 even in the state of FIG. 6 in which the projecting step of the spherical portion is started, Poor heat conduction efficiency, for example, the temperature of punch 1 and pad 2 is 100 °
Even at this time, the temperature of the mask material 6 in the part which is not in contact is about 70 °, and the mask material 6 is not molded in a sufficiently heated state. For this reason, springback becomes large in the peripheral portion of the molding mask 7, a concave deformation portion 7a is generated as shown in FIG. 12, and when the color cathode-ray tube operates, there is a problem in that color purity is deteriorated due to vibration and the like. there were.

In the process shown in FIG. 10 in which the mask 1 is lifted from the bottom dead center after the mask skirt 6a is formed, when the punch 1 is pulled up, a friction force acting between the side wall of the punch 1 and the mask skirt 6a is used. As shown in FIG. 13, when only one side of the molding mask 7 is pulled up, there is a problem that wrinkles 7b are generated in the spherical portion of the molding mask 7 where the temperature rises and the proof stress of the mechanical characteristics is lowered. .

The present invention has been made to solve the above problems, and a warm press molding die capable of heating the shadow mask material to the peripheral portion sufficiently from the initial stage of the spherical portion projecting step. The purpose is to obtain a mold device. Moreover, it aims at obtaining the warm press molding method using this metal mold | die apparatus.

[0009]

In a press-molding die apparatus according to the present invention, a heating element is arranged in a punch and a pad, a plurality of gas outlets are formed in the punch, and an exhaust port is provided in the pad. An air supply device for selectively supplying a high temperature, normal temperature, low temperature or high pressure gas to the air outlet is provided.

In addition to the punch and the pad, a heating element is provided in the die and the wrinkle retainer, a plurality of gas outlets are formed in the punch, an exhaust port is provided in the pad, and the air outlet has a high temperature and a normal temperature. An air supply device for selectively supplying low-temperature or high-pressure gas is provided.

In the press-molding die method according to the present invention, the heating element containing the punch, the pad, the die and the wrinkle retainer is heated to a desired temperature and is placed in the die. The molded member is blown with a high-temperature gas from a gas outlet into a mold, heated to a desired temperature, and then press-molded.

Before the punch is pulled up after forming the member to be molded, air at room temperature or low temperature is blown from the air feeding device and blown out into the mold from the gas outlet to control the temperature of the member to be shaped. After lowering it, the punch is pulled up.

Further, when the punch is pulled up after the forming target member is formed and processed, a high pressure gas is supplied from the air supply device,
High-pressure air is blown into the mold from a gas outlet, and the punch is pulled up while preventing the member to be molded from separating from the mold.

[0014]

According to the press molding die apparatus according to the present invention,
Since the high temperature, normal temperature, low temperature or high pressure gas is sent from the air supply device and blown out into the mold from the gas outlet formed in the punch, the temperature or air pressure of the air sent from the air supply device. Can be adjusted to control the temperature of the member to be molded or to prevent the member to be molded from rising with respect to the punch.

According to the press molding method of the present invention,
The temperature of the member to be molded can be uniformly adjusted to a desired temperature before starting the press molding process.

When the punch is pulled up after the squeezing process, the temperature of the member to be molded can be lowered to a desired temperature.

Further, by blowing high-pressure gas from the gas outlet after the press molding, it is possible to prevent the member to be molded from adhering to the punch and coming off the mold.

[0018]

【Example】

Example 1. An embodiment of the warm press molding die device according to the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of this embodiment. The same parts as those in FIG. In the drawing, 8 is an air outlet provided at an appropriate interval on the peripheral portion of the punch 1, 9 is a supply port thereof, and 10 is an air supply device, which is high temperature air of 150 to 250 ° C., normal temperature air or high pressure air. To selectively supply.
Reference numeral 11 denotes a pipe, which connects between the air supply device 10 and the supply port 9. Reference numeral 12 denotes an exhaust port formed in the pad 2, and the air blown out from the air outlet port 8 passes through an electron beam passage hole (not shown) formed in the shadow mask material plate 6 and an exhaust port to outside the mold. Exhausted to. It should be noted that the warm air and the room temperature air may be configured as separate supply and discharge systems.

Example 2. Next, an example of a warm press molding method using the above warm press molding apparatus will be described.
FIG. 2 is a view showing a state before the step of forming a spherical portion by extrusion forming on the shadow mask material plate 6 according to this embodiment, which corresponds to FIG. 6, in which the shadow mask material plate 6 and the punch are punched. Although the central portion of 1 is in contact, the peripheral portion of the shadow mask material plate 6 and the punch 1 and the pad 2 are in this state from the air supply device 10 to 150 ° C to 250 ° C.
When the high temperature air of ℃ is sent and blown out from the hot air outlet 8, the high temperature air flows and the shadow mask material plate 6 is uniformly heated as shown by the arrow in the figure. In this way, when the temperature of the shadow mask material plate 6 rises to 100 ° C. to 200 ° C., the punch 1 is lowered to perform the overhang molding of the spherical surface of the mask, and the same method as in the conventional example shown in FIGS. The press forming process of the forming mask 7 is completed through the forming process.

According to this embodiment, it is possible to perform press forming with high accuracy even with a material having a large spring back such as Invar, and the occurrence of the concave deformed portion 7a shown in FIG. 12 is reduced.

Example 3. Next, another embodiment of the warm press forming method will be described. FIG. 3 is a view showing a state corresponding to FIG. 10 in which the punch is raised from the bottom dead center following the mask skirt forming step. In this embodiment, before the punch 1 is lifted from the state shown in FIG. 9, room temperature or low temperature air is supplied from the air supply device 10 and blown out from the air outlet 8 to bring the temperature of the forming mask to 50 ° C. to 70 ° C. After cooling, the punch 1 is raised and pulled out from the forming mask 7. By doing so, the deformation resistance of the forming mask becomes large, and even if one side of the forming mask 7 is pulled up as shown in FIG. 13, the wrinkles 7b are less likely to occur.

Example 4. In the third embodiment, when the high-pressure air is supplied when the room temperature air is supplied, the forming mask 7 is pressed against the surface of the pad 2 by the air flow, so that when the punch 1 as shown in FIG. 13 is raised. It is possible to prevent one of the molding masks from being pulled up, and it is possible to prevent the generation of wrinkles 7b associated with this pulling up.

[0023]

According to the warm press molding die apparatus of the present invention, a plurality of air outlets are provided at the peripheral edge of the punch, and air having a desired temperature and pressure is supplied from the air outlets. Then, the temperature of the member to be molded can be controlled to a desired temperature.

According to the warm press-molding method of the present invention, the hot gas can be fed before press-molding so that the temperature of the member to be molded can be uniformly heated to a desired temperature, so that the processing accuracy is improved. .

Further, before the punch is pulled out from the member to be molded after press molding, air at room temperature or low temperature is blown out from the air outlet to cool the molded product to a desired temperature and then pull out the punch. The deformation resistance of the molded member is improved, and the deformation at the time of taking out can be reduced.

Further, since the high pressure air is blown from the air outlet to press the member to be molded against the pad side when the punch is pulled out after molding, the member to be molded is pulled up by the punch when the punch is raised. It is possible to reduce the occurrence of deformation.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a warm press molding die device according to a first embodiment of the present invention.

FIG. 2 is a second embodiment of the warm press molding method according to the present invention.
FIG. 6 is a vertical cross-sectional view showing the state of the mold in the process of the main part of FIG.

FIG. 3 is a third embodiment of the warm press molding method according to the present invention.
9 is a vertical cross-sectional view showing a state of a mold in a process of a main part of Example 4. FIG.

FIG. 4 is a vertical sectional view of a conventional warm press molding die.

FIG. 5 is a vertical cross-sectional view showing the state of the mold in the first step of the press molding operation of the conventional example.

FIG. 6 is a vertical cross-sectional view showing the state of the mold in the second step of the press molding operation of the conventional example.

FIG. 7 is a vertical cross-sectional view showing a state of a mold in a third step of the press molding operation of the conventional example.

FIG. 8 is a vertical cross-sectional view showing a state of a mold in a fourth step of the press molding operation of the conventional example.

FIG. 9 is a vertical cross-sectional view showing a state of a mold in a fifth step of the press molding operation of the conventional example.

FIG. 10 is a vertical cross-sectional view showing a state of a mold in a sixth step of the press molding operation of the conventional example.

FIG. 11 is a vertical cross-sectional view showing the state of the mold in the seventh step of the press molding operation of the conventional example.

FIG. 12 is a cross-sectional view showing a concave deformation portion generated in a spherical portion of a molding mask in a conventional example.

FIG. 13 is a diagram for explaining a meganism in which wrinkles are generated in a spherical portion of a forming mask when a punch is pulled up after warm press forming in a conventional example.

[Explanation of symbols]

 1 Punch 2 Pad 3 Wrinkle retainer 4 Die 5 Heating element 6 Mask material plate 6a Mask skirt 7 Molded mask 8 Air blowout port 9 Supply port 10 Air supply device 11 Piping 12 Exhaust port

[Procedure amendment]

[Submission date] August 23, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

According to this embodiment, it is possible to perform press forming with high accuracy even with a material having a large spring back such as Invar, and the peripheral edge concave deformed portion 7a shown in FIG.
Is less likely to occur.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 12

[Correction method] Change

[Correction content]

12A and 12B are a plan view and a cross-sectional view showing a concave deformed portion that occurs in a spherical portion of a molding mask in a conventional example.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 12

[Correction method] Change

[Correction content]

[Fig. 12]

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 13

[Correction method] Change

[Correction content]

[Fig. 13]

Claims (5)

[Claims] 1. A pad having an exhaust port formed therein, and a punch having a plurality of air outlets which are arranged so as to face the pad so as to be able to move forward and backward and press a member to be molded between the pad and the member for molding. A heating element disposed in each of the pad and the punch, and a means for heating these heating elements,
A press-molding die device comprising an air supply device for selectively supplying high-temperature, normal-temperature, low-temperature or high-pressure gas to the air outlet. 2. A pad in which an exhaust port is formed, a die arranged so as to be able to move forward and backward around the pad, a die which can be moved forward and backward so as to face the die, and is mounted on the surface of the pad and the die. A wrinkle retainer for pressing and holding the peripheral edge portion of the molding target member with the die, and a plurality of molding units arranged so as to be capable of advancing and retreating facing the pad, and pressing the molding target member between the pad and the pad. A punch having an air outlet, a pad, a die, a wrinkle retainer, and a heating element respectively arranged in the punch, a means for heating these heating elements, a high temperature, a normal temperature, a low temperature to the air outlet or A press-molding die apparatus including an air-feeding device that selectively supplies high-pressure gas. 3. When performing warm press molding on a member to be molded using the press molding die apparatus according to claim 1 or 2, first of all, a high temperature gas is fed from an air feeding unit into the die. A press-molding method, wherein the member to be molded attached to the mold is heated to a predetermined temperature and then press-molded. 4. When the member to be molded is subjected to warm press molding by using the press molding die apparatus according to claim 1 or 2, air is fed after the molding of the member to be molded and before the punch is pulled up. A press molding method characterized in that a room temperature or low temperature gas is fed from the apparatus to lower the temperature of a member to be molded, and then the punch is pulled up. 5. When press-molding a member to be molded using the press-molding die apparatus according to claim 1 or 2, when the punch is pulled up after the molding of the member to be molded,
A press molding method, wherein a punch is pulled up while supplying high-pressure gas from an air supply device.