JP2010046673A - Method for manufacturing integrally-formed hollow article by hot blow-forming, mold and to-be-formed material used in the same method for manufacturing integrally-formed hollow article by hot blow-forming - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply, certainly, and quickly manufacture an integrally-formed hollow article having a complicated shape by hot blow-forming. <P>SOLUTION: Exhaust holes 3b, 4b communicating with the outside are formed in a male mold 3 and a female mold 4. A truncated cone part 3c having a recess part 3e communicating with a gas supplying hole 3f is formed in the male mold 3. The peripheral edges of an upper plate 5a and a lower plate 5b of a to-be-formed material 5 that are superimposed are sealed, and a gas suction hole 5d is formed in the central part of the upper plate 5a. In the mold 2, the recess part 3e of the truncated cone part 3c of the male mold 3 and the gas suction hole 5d of the upper plate 5a are brought into tight contact with each other so as to fit each other, and blow-forming is conducted while forming an enclosed space 6 by pinching and fixing the to-be-formed material 5. Since the to-be-formed material is expanded along the inner faces of the molds while exhausting the air held between the recess part of the die and the to-be-formed material to the outside, the integrally-formed hollow article is simply, certainly, and quickly manufactured. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for hot blow molding of a hollow integrated molded product in which a hollow portion is formed inside, for example, a body sheet inner material and a reinforcement or an inner material and an outer material of an automobile, etc., and the hot blow molding The present invention relates to a molding material for hot blow molding used in the method and a hot blow molding apparatus using the hot blow molding method.

  Conventionally, as a method for producing a hollow integrated molded product by a hot blow molding method, first, a holding member is provided for holding a metal plate between the upper end portion of the lower die and the lower end portion of the upper die. A discharge port connected to a pressure source is provided in the holding member, and a plug that has a molding gas supply hole between two superplastic material plates that are formed by using compressed air from the pressure source (see Patent Document 1) or two laminated superplastic material plates. There is an apparatus that performs molding by inserting a molding gas between the two superplastic material plates through a molding gas supply hole of the plug (see Patent Document 2).

JP-A-5-50154 Japanese Patent Laid-Open No. 7-1050

In the above-described conventional method for producing a hollow integrally formed product by hot blow molding, the compressed gas or molding gas used for molding the metal plate or laminated superplastic material plate is the metal plate or laminated superplastic material plate. It supplies to the inside from the side.
However, since the internal pressure is greatly increased by the compressed gas or molding gas supplied inside the metal plate or the laminated superplastic material plate that expands along the mold, the compression pressure is prevented in order to prevent the gas pressure from being released. A discharge port or a plug provided for supplying gas or forming gas into a metal plate or a laminated superplastic material plate is required to have high airtightness.
As a result, the airtight structure in the discharge port or plug becomes complicated, leading to an increase in manufacturing cost.

  In addition, since a discharge port or a plug for supplying compressed gas or molding gas to the inside is provided at a part of the periphery of the hollow integrated molded product, deformation of the peripheral edge of the hollow integrated molded product generated by the discharge port or plug after molding Work for correcting the problem is required, and workability is reduced.

Further, in blow molding, since the surface of a molding material such as a metal plate or a laminated superplastic material plate is completely brought into close contact with the inner surface of the mold, air is blown in the mold by the molding material that expands during molding. If it remains, molding will be hindered.
Accordingly, the molding speed cannot be sufficiently increased, and it is difficult to reliably remove air during molding with a complicated molding shape, and there is a possibility that accurate molding cannot be performed.

  Accordingly, the present invention makes it possible to manufacture a hollow integrated molded product by blow molding simply, reliably and quickly, and to provide a molding material used in the blow molding.

In order to solve the above problem, as a first feature,
It consists of a male mold and a female mold that form an exhaust hole that communicates with the outside in the recess, and in the male mold, the top of the base that is formed to be flush with the opening at the center In the mold in which the recessed portion that leads to the gas supply hole for supplying the inert high-pressure gas is disposed,
The upper and lower plates made of superplastic metal are laminated, and the periphery is sealed together to form a joint, and a gas suction hole is formed in the upper plate so as to communicate with the inside of the joint. Between the male mold and the female mold forming the mold, the molding material gas is placed in the opening of the concave portion disposed on the top of the base of the male mold. Clamp and fix so that the suction holes match,
Forming a sealed space with the concave portion at the top of the base of the male mold and the upper plate of the molding material formed with a gas suction hole;
Heating at least the molding material to the superplastic temperature range,
Supplying an inert high-pressure gas through a gas supply hole in a sealed space formed in the mold,
At the same time as expanding the molding material by press-fitting an inert high-pressure gas in the sealed space into the molding material through the gas suction hole of the molding material,
As the molding material expands from inside the mold, the air between the recess and the molding material is discharged outside through the exhaust hole,
The molding material is formed into a hollow integrally molded product by a mold.

  Therefore, when forming a hollow integral molded product, the inert high-pressure gas supplied through the gas supply hole is filled in a sealed space formed between the molding material and the recessed portion of the male mold, and the inert high-pressure gas is supplied. The gas increases in density and flow rate to higher pressures. As a result, the high-pressure inert high-pressure gas is pressed into the molding material gas suction hole at a time, so that the molding material is rapidly expanded and the gap between the recess and the molding material in the mold. Since the air is discharged to the outside through the exhaust hole of the mold, it can be formed into a hollow integrated molded product easily and reliably and quickly.

The inert high-pressure gas that is press-fitted into the molding material during blow molding of the hollow integrated molded product is preferably argon gas or nitrogen gas in order to prevent deterioration of the molding material or a fire.
The gas pressure of the inert high pressure gas is 0.2 to 15 MPa, and 1 MPa is optimal. That is, if the gas pressure of the inert high-pressure gas is less than 0.2 MPa, it takes too much time to manufacture the molded product of the hollow integral molded product, and the working efficiency is lowered, and if the gas pressure is more than 15 MPa, it is used. The amount of the inert high pressure gas used becomes too large, and the molding cost of the hollow integrated molded product is too high.

  Furthermore, the heating temperature of the mold or the molding material at the time of blow molding is suitably a superplastic temperature range of the superplastic metal forming the upper and lower plates of the molding material, that is, 300 ° C. or more and 550 ° C. or less. That is, if the heating temperature of the mold or the molding material is less than 300 ° C., the expansion rate of the molding material in blow molding becomes slow and the working efficiency decreases, and if the heating temperature exceeds 550 ° C., the molding material Therefore, it is not suitable to use as a structural member, and a cavity is generated in the molding material, resulting in a decrease in mechanical characteristics.

  Based on the first feature, as a second feature, the mold used in the method for producing a hollow integrated molded product by hot blow molding is a male die having an exhaust hole that communicates with the outside in the recess. Consists of a mold and a female mold, and the male mold has a recess through which a gas supply hole for supplying an inert high-pressure gas communicates with the top of the base portion formed so as to be flush with the opening at the center. The part is arranged.

  Therefore, when the molding material expands in the mold, the air between the concave portion of the mold and the molding material is perforated so as to communicate with the outside in the concave portion of the male mold and the female mold. It is discharged from the exhaust hole provided. As a result, even if the inner surface of the mold has a complicated shape, the molding material smoothly expands along the inner surface of the mold, so that a hollow integrated molded product can be accurately molded.

  Further, based on the first feature, as a third feature, the molding material used in the method for producing a hollow integrated molded product by hot blow molding is obtained by laminating an upper plate and a lower plate made of superplastic metal. The peripheral edge is integrally sealed to form a joint portion, and a gas suction hole is formed in the upper plate so as to communicate with the inside of the joint portion.

  Therefore, it is only necessary to pierce the gas suction hole having a simple shape in the upper plate that forms the molding material, so that leakage of the inert high-pressure gas for expanding the molding material as in the conventional molding material is prevented. Therefore, a complicated airtight structure can be eliminated.

Here, the upper plate or the lower plate forming the molding material is a superplastic metal. Specifically, in addition to a titanium alloy-based or stainless steel-based alloy exhibiting superplastic characteristics, an Al alloy, that is, Al- Zn-based, Al-Mg-based, Al-Mg-Mn-based, Al-Zn-Mg-Cu-based, Al-Cu-based, Al-Li-based, Al-Mg-Si-based, Al-Si-based, etc. In particular, when an Al alloy is used as the superplastic metal, a JIS 5083 Al alloy plate is preferable.
Further, the area of the gas suction hole formed in the molding material is a male type that forms a sealed space together with the molding material so that an inert high-pressure gas that expands the molding material can be smoothly pressed into the molding material. When the area of the opening in the recessed portion of the mold is 100, it is desirable to set it to 5-100. That is, if the area of the gas suction hole is less than 5 with respect to the area 100 of the opening in the recessed part of the male mold, the pressure of the inert high-pressure gas that is pressed into the molding material from the gas suction hole of the molding material is high. Since the entire molding material is bent too much, the inert high-pressure gas is discharged from the exhaust hole in the concave portion of the male mold, and blow molding cannot be performed.

Further, the joint formed on the periphery of the molding material composed of the upper plate and the lower plate is sandwiched between a male mold and a female mold constituting the mold and is plastically deformed and sealed. In addition to the method, the joint may be formed by a friction stir welding method, a welding method, and a pressure bonding method.
In addition to sealing the periphery of the molding material, the upper plate and the lower plate forming the molding material in the mold are clamped and fixed, and then the upper plate is previously clamped and fixed in the mold. And the lower plate may be laminated and the peripheral edges thereof may be bonded to form a bonded portion.

  In the invention of the present application, in producing a hollow integrated molded product by hot blow molding, an inert high-pressure gas is press-fitted into a gas suction hole of a molding material from a sealed space formed in a mold and expanded, Since the air between the recess of the mold and the molding material is discharged from the exhaust hole, the structure of the molding material itself can be simplified, and the molding material can be easily and reliably hollowed quickly. Since it can be molded into a molded product, it has an excellent effect of improving work efficiency and reducing manufacturing cost.

Examples of the present invention will be described below.
In addition, this Example is for demonstrating one preferable embodiment of this invention, Comprising: This invention is not restrict | limited by this.

  A hot blow molding apparatus 1 according to a manufacturing method of a hollow integral molded product by hot blow molding according to the present invention includes a mold 2 containing a heater (not shown), and an inert high-pressure gas with respect to the mold 2. 7 comprises an inert high-pressure gas supply device (not shown) that can be supplied intermittently.

Here, the mold 2 used in the hot blow molding apparatus 1 is composed of a male mold 3 and a female mold 4.
First, the male mold 3 is provided with a concave portion 3a for forming an exhaust hole 3b for exhausting air 8 between a concave portion 3a and a molding material 5, which will be described later, on the inner surface thereof, and the male mold 3 An inert high-pressure gas supply device for press-fitting an inert high-pressure gas 7 after providing a conical base portion (hereinafter referred to as a “conical base portion”) 3 c so as to be flush with the opening 3 d at the center of A recessed portion 3e that communicates with the gas supply hole 3f that communicates with the gas is provided. The peripheral edge of the male mold 3 is provided with a peripheral sealing bead 3g used for sealing a peripheral edge of a molding material 5 to be described later. , The inner surface is provided with a recess 4a for forming an exhaust hole 4b for discharging air 8 between the recess 4a and the molding material 5 to be described later. In addition, a concave groove 4 d corresponding to the peripheral sealing bead 3 g of the male mold 3 is provided around the peripheral edge of the female mold 4 to seal the peripheral edge of the molding material 5. is there.

  In addition, the molding material 5 used in the method for manufacturing a hollow integrated molded product by hot blow molding according to the present invention is obtained by laminating an upper plate 5a and a lower plate 5b made of superplastic metal, and integrally sealing the periphery thereof. The upper plate 5a is formed with a gas suction hole 5d so as to communicate with the inside of the upper plate 5a.

Therefore, in the hot blow molding apparatus 1 according to the method for manufacturing a hollow integrated molded product by hot blow molding according to the present invention, the hollow integrated molded product 9 is manufactured as follows.
That is, in the hot blow molding apparatus 1, the male mold 3 is interposed between the male mold 3 and the female mold 4 that form the mold 2 that communicates with the inert high-pressure gas supply apparatus through the gas supply hole 3 f. The molding material 5 is sandwiched and fixed so that the opening 3h of the recessed portion 3e disposed in the truncated cone portion 3c formed therein and the gas suction hole 5d drilled in the upper plate 5a of the molding material 5 match. To do.
As a result, the sealed space 6 is formed by the concave portion 3e of the male mold 3 and the upper plate 5a of the molding material 5 formed with the gas suction hole 5d that matches the concave portion 3e.
Then, when the molding material 5 is heated to a superplastic temperature range by a heater built in the mold 2 in advance, a peripheral sealing bead 3g provided around the periphery of the male mold 3 at the periphery of the molding material 5; The joint 5c is formed by the concave groove 4d of the female mold 4 and the periphery of the molding material 5 is sealed.
Then, an inert high pressure gas 7 is supplied into the sealed space 6 formed by the male mold 3 and the upper plate 5a of the molding material 5 in the mold 2 through the gas supply hole 3f, and the molding is performed. The molding material 5 expands by press-fitting the inert high-pressure gas 7 into the molding material 5 from the gas suction hole 5 d of the material 5.
As a result, the molding material 5 that expands in the mold 2 forms a joint portion 5 c at the periphery, and is securely adhered along the inner surface of the mold 5 to form the mold 2 and the female mold 3. Molded into a hollow integrated molded product 9 having convex portions 9a, 9b corresponding to the concave portions 3a, 4a of the mold 4 (see FIG. 5).
At this time, the air 8 between the recesses 3a and 4a of the male mold 3 and the female mold 4 constituting the mold 2 and the molding material 5 is transferred to each of the male mold 3 and the female mold 4 respectively. The gas is discharged to the outside through the exhaust holes 3b and 4b.

Therefore, the hollow integrated molded product 9 was actually manufactured under the following conditions.
First, as the molding material 5, for the upper plate 5 a and the lower plate 5 b to be laminated, JIS 5083-H18 aluminum alloy having a plate thickness of 1 mm is cut into 400 mm square, and the central portion of the upper plate 5 a has a diameter of 10 mm. A circular gas suction hole 5d was formed.
The mold 2 in the hot blow molding apparatus 1 is as follows.
That is, the male mold 3 is provided with a peripheral sealing bead 3g for sealing the peripheral edge of the molding material 5 along the peripheral edge, and the recess 3a has a depth of 20 mm and an opening. 3d has a trapezoidal shape with a vertical and horizontal dimension of 300 × 300 mm, the top diameter of the opening 3d and the top 3i being flush with each other at the center of the opening 3d is φ60 mm, the bottom diameter is φ80 mm, and the height is A 20 mm truncated cone part 3c is formed. A concave portion 3e having a diameter of 20 mm and a depth of 10 mm is formed in the central portion of the top portion 3i of the truncated cone portion 3c, and a gas supply hole 3f communicates with the concave portion 3e.
The female die 4 is provided with a concave groove 4d corresponding to the peripheral sealing bead 3g provided around the peripheral edge of the male die 3 for sealing the peripheral edge of the molding material 5 along the peripheral edge. Thus, the trapezoidal shape of the vertical section is 40 mm deep and the opening 4 c is 300 × 300 mm in length and width.
Then, the molding material 5 formed by laminating the upper plate 5a and the lower plate 5b is placed on the opening 4c side of the female mold 4 of the hot blow molding apparatus 1, and the molding material 5 is placed on the upper plate 5a. The recessed portion formed in the top portion 3i of the male mold 3 so that the gas suction hole 5d formed and the opening 3h of the recessed portion 3e formed in the truncated cone portion 3c of the male mold 3 match. The opening 3h side of 3e was installed so as to be in close contact with the upper plate 5a and clamped and fixed. As a result, the top 3 i of the truncated cone part 3 c of the male mold 3 is in close contact with the upper plate 5 a of the molding material 5, and the recessed part 3 e of the truncated cone part 3 c is formed with the upper plate 5 a of the molding material 5 of the male mold 3. It is isolated from the recess 3a to form a sealed space 6.
After that, the mold 2 is heated to 500 ° C. including the molding material 5, and the periphery of the molding material 5 is connected to the peripheral sealing bead 3 g of the male mold 3 and the concave groove 4 d of the female mold 4. It was sealed by being deformed by forming the joint 5c.
Thereafter, hot blow molding was performed on the molding material 5 with the peripheral edge sealed under molding conditions in which the gas pressure of the inert high-pressure gas was 1 MPa and the molding time was 10 minutes.
As a result, in the mold 2, the upper plate 5 a expands so as to be in close contact with the inner surface of the concave portion 3 a of the male mold 3, and the lower plate 5 b expands in close contact with the inner surface of the concave portion 4 a of the female mold 4. Thus, the effect of the present invention was confirmed.
At this time, air 8 between the concave portion 3 a of the male mold 3 and the concave portion 4 a of the female mold 4 and the molding material 5 passes through the exhaust hole 3 b of the male mold 3 and the exhaust hole 4 b of the female mold 4. It was also confirmed that it was discharged.

In addition, as a comparative example with respect to the method for producing a hollow integrated molded product by hot blow molding according to the present invention, the hot blow molding was performed by the hot blow molding apparatus 1 under the following conditions, and the respective comparative studies were conducted. .
That is, when the truncated cone part 3 c is not formed at the center of the opening 3 d of the male mold 3, the inert high-pressure gas 7 is discharged from the exhaust hole 3 b of the male mold 3 and the molding material 5 Blow molding cannot be performed (Comparative Example 1), and when the gas suction hole 5d is not formed in the upper plate 5a constituting the molding material 5, the molding material 5 is once bent in the direction of the female die 4. However, the inert high pressure gas 7 is discharged from the exhaust hole 3b of the male mold 3 through the gap formed between the truncated cone part 3c and the molding material 5 due to the bending of the molding material 5, and the molding material 5 Blow molding cannot be performed (Comparative Example 2), and the upper plate of the molding material 5 from within the opening 3h of the recessed portion 3e formed in the truncated cone portion 3c at the center of the opening 3d in the male mold 3 When the position of the gas suction hole 5d drilled in 5a is shifted, the molding material 5 is once a female mold. Although being bent in the direction of the mold 4, the inert high pressure gas 7 is discharged from the exhaust hole 3 b of the male mold 3 through a gap formed between the truncated cone portion 3 c and the molding material 5 by the bending of the molding material 5. Therefore, the molding material 5 cannot be blow-molded (Comparative Example 3), and the gas in the molding material 5 and the recessed portion 3e formed in the truncated cone portion 3c at the center of the opening 3d in the male mold 3 is obtained. Although the position of the suction hole 5d coincides, but the diameter of the gas suction hole 5d is too small, the molding material 5 once bends in the direction of the female mold 4, but the molding material 5 bends to form a cone. The inert high pressure gas 7 is discharged from the exhaust hole 3b of the male mold 3 through the gap formed between the base portion 3c and the molding material 5, and the molding material 5 cannot be blow molded (comparative example). 4) The top of the truncated cone part 3c at the center of the opening 3d in the male mold 3 3i and the upper plate 5a constituting the molding material 5 are not in close contact with each other and a gap is generated, the inert high-pressure gas 7 supplied into the mold 2 is injected into the molding material 5 through the gas suction hole 5d of the upper plate 5a. The molded material 5 cannot be blow-molded (Comparative Example 5) because it is not press-fitted into the interior and is discharged from the exhaust hole 3b of the male mold 3 through the gap.

  The present invention can be widely applied not only to a simple shape but also to a complex shape hollow integral molded product when producing a hollow integral molded product by hot blow molding.

It is sectional drawing of the hot blow molding apparatus by the manufacturing method of the hollow integral molded article by the hot blow molding of this invention. It is sectional drawing which shows the manufacturing process of the hollow integral molded article by the manufacturing method of the hollow integral molded article by hot blow molding of this invention. It is a perspective view of the molding material used in the manufacturing method of the hollow integral molded article by the hot blow molding of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a front view from the opening part direction of the (a) male type metal mold | die and (b) female type metal mold | die used in the manufacturing method of the hollow integral molded article by hot blow molding of this invention. It is a perspective view of the hollow integral molded article by the manufacturing method of the hollow integral molded article by hot blow molding of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot blow molding apparatus 2 Mold 3 Male mold 3a Recess 3b Exhaust hole 3c Frustum 3d Opening 3e Recess 3f Gas supply hole 3g Peripheral sealing bead 3h Open 3i Top 4 Female mold 4a Concave part 4b Exhaust hole 4c Opening part 4d Concave groove 5 Molded material 5a Upper plate 5b Lower plate 5c Joint part 5d Gas suction hole 6 Sealed space 7 Inert high-pressure gas 8 Air 9 Hollow integrated molded product 9a, 9b Convex part

Claims (3)

It consists of a male mold and a female mold that form an exhaust hole that communicates with the outside in the recess, and in the male mold, the top of the base that is formed to be flush with the opening at the center In the mold in which the recessed portion that leads to the gas supply hole for supplying the inert high-pressure gas is disposed,
The upper and lower plates made of superplastic metal are laminated, and the periphery is sealed together to form a joint, and a gas suction hole is formed in the upper plate so as to communicate with the inside of the joint. Between the male mold and the female mold forming the mold, the molding material gas is placed in the opening of the concave portion disposed on the top of the base of the male mold. Clamp and fix so that the suction holes match,
Forming a sealed space with the concave portion at the top of the base of the male mold and the upper plate of the molding material formed with a gas suction hole;
Heating at least the molding material to the superplastic temperature range,
Supplying an inert high-pressure gas through a gas supply hole in a sealed space formed in the mold,
At the same time as expanding the molding material by press-fitting an inert high-pressure gas in the sealed space into the molding material through the gas suction hole of the molding material,
With the expansion of the molding material from the inside of the mold, the air between the recess and the molding material is discharged outside through the exhaust hole,
A method for producing a hollow integral molded article by hot blow molding, wherein the molding material is molded into a hollow integral molded article by a mold. A male die and a female die that are used in the method for producing a hollow integrated molded product by hot blow molding according to claim 1 and that have an exhaust hole that communicates with the outside inside the recess. The mold is characterized in that a concave portion through which a gas supply hole for supplying an inert high-pressure gas communicates is disposed at the top of a base portion formed so as to be flush with the opening at the center. It is used in the method for producing a hollow integrally molded product by hot blow molding according to claim 1, wherein an upper plate and a lower plate made of superplastic metal are laminated, and the periphery is integrally sealed to form a joint portion. In addition, the molding material is characterized in that a gas suction hole is formed in the upper plate so as to communicate with the inside of the joint portion.

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