阅读说明：本技术 复合材料的成形方法和复合材料的成形装置 (method and apparatus for molding composite material ) 是由 大槻晃久 臼井胜宏 于 2018-04-19 设计创作，主要内容包括：提供能够抑制在复合材料产生孔隙,并提高复合材料的机械特性、外观品质的复合材料的成形方法和复合材料的成形装置。在复合材料(10)的制造方法中,利用第1密封构件(310)将包含配置有增强基材(11)的模腔(250)以及与模腔的外周相连通的外周区域(260)的密封区域(270)气密地密封。然后,开始从外周区域抽吸气体而将密封区域内的气体排出的操作,向模腔内的一部分注入树脂(12)。接着,将成形模具(200)合模,挤压树脂使其向模腔内填充,并且利用第2密封构件(320)将模腔与外周区域之间液密地密封。然后,停止从外周区域抽吸气体的操作。(provided are a method for molding a composite material and an apparatus for molding a composite material, which are capable of suppressing the occurrence of voids in the composite material and improving the mechanical properties and the appearance quality of the composite material. In a method for manufacturing a composite material (10), a sealing region (270) including a cavity (250) in which a reinforcing base material (11) is disposed and an outer peripheral region (260) that communicates with the outer periphery of the cavity is hermetically sealed by a first sealing member (310). Then, the operation of sucking the gas from the outer peripheral region and exhausting the gas in the sealed region is started, and the resin (12) is injected into a part of the cavity. Then, the molding die (200) is closed, the resin is extruded to fill the cavity, and the gap between the cavity and the outer peripheral region is liquid-tightly sealed by the 2 nd sealing member (320). Then, the operation of sucking the gas from the outer peripheral area is stopped.)

1. A method of forming a composite material, wherein,

disposing a reinforcing base material in a cavity of a forming mold including a 1 st mold and a 2 nd mold, the 2 nd mold forming the cavity between the 1 st mold and the 2 nd mold;

Bringing the 1 st mold into relative proximity to the 2 nd mold, and hermetically sealing a sealing region including the cavity and an outer peripheral region communicating with an outer periphery of the cavity with a 1 st sealing member;

Starting an operation of sucking gas from the outer peripheral area to discharge the gas in the sealed area;

Injecting a resin into a portion of the mold cavity,

Closing the molding die by relatively approaching the 1 st die to the 2 nd die, pressing the resin to fill the cavity, and liquid-tightly sealing the cavity and the outer peripheral region with a 2 nd sealing member;

Stopping the operation of sucking gas from the outer peripheral area.

2. the method of forming a composite material according to claim 1,

The 1 st seal member and the 2 nd seal member are disposed on a surface along a mold clamping direction in which the 1 st mold and the 2 nd mold are relatively brought close to each other, among surfaces of the 1 st mold and the 2 nd mold that face each other.

3. The method for forming a composite material according to claim 1 or 2,

The 1 st mould is an upper mould,

The 2 nd die is a lower die,

sucking gas through a gas discharge port arranged on an upper side of the outer peripheral area in the upper mold when sucking gas from the outer peripheral area,

The volume of the outer peripheral region is larger than the volume of the resin injected into the cavity in a state where the molding die is clamped.

4. The method of forming a composite material according to claim 3,

The upper mold has a concave portion having a shape recessed toward an upper side,

The lower mold has a convex portion that forms the cavity between the convex portion and the concave portion.

5. The method for forming a composite material according to claim 3 or 4,

When the resin is injected into a part of the cavity, the resin is injected through an injection port disposed in the upper mold.

6. the method for forming a composite material according to any one of claims 1 to 5,

The reinforcing base material is formed by coating a fiber base material with a binder resin and then curing the binder resin,

The resin softening point of the binder resin is equal to or higher than the temperature of the molding die.

7. The method of forming a composite material according to claim 6,

The binder resin is a thermosetting epoxy resin.

8. A forming device for composite material, wherein,

the composite material forming apparatus comprises:

A forming mold provided with a 1 st mold and a 2 nd mold, the 2 nd mold forming a cavity between the 1 st mold and the 2 nd mold;

A 1 st sealing member that hermetically seals a sealing area including the cavity and an outer peripheral area communicating with an outer periphery of the cavity between the 1 st mold and the 2 nd mold;

A 2 nd sealing member that liquid-tightly seals between the cavity and the outer peripheral region;

An exhaust unit that sucks gas from the outer peripheral region and exhausts the gas in the sealed region;

a resin injection part which injects resin into the mold cavity; and

a control unit that controls operations of the molding die, the exhaust unit, and the resin injection unit,

With regard to the control section, it is preferable that,

Relatively approaching the 1 st mold and the 2 nd mold, and hermetically sealing the sealing area by the 1 st sealing member;

Controlling the operation of the exhaust part to start the operation of exhausting the gas in the sealing area;

Controlling the operation of the resin injection part and injecting the resin into the mold cavity;

Closing the molding die by relatively approaching the 1 st die to the 2 nd die, pressing the resin to fill the cavity, and liquid-tightly sealing the cavity and the outer peripheral region with the 2 nd sealing member;

stopping the operation of sucking gas from the outer peripheral area.

9. The composite forming apparatus of claim 8,

The 1 st seal member and the 2 nd seal member are disposed on a surface along a mold clamping direction in which the 1 st mold and the 2 nd mold are relatively brought close to each other, among surfaces of the 1 st mold and the 2 nd mold that face each other.

10. The apparatus for forming a composite material according to claim 8 or 9,

The 1 st mould is an upper mould,

The 2 nd die is a lower die,

The exhaust part is communicated with an exhaust port arranged at the upper side of the peripheral area in the upper die,

In a state where the molding die is clamped, a volume of the outer peripheral region is larger than a volume of the resin injected into the cavity.

11. The composite forming apparatus of claim 10,

The upper mold has a concave portion having a shape recessed toward an upper side,

the lower mold has a convex portion that forms the cavity between the convex portion and the concave portion.

12. the apparatus for forming a composite material according to claim 10 or 11,

The resin injection portion communicates with an injection port disposed on the upper mold.

Technical Field

The present invention relates to a method and an apparatus for molding a composite material.

Background

In recent years, composite materials in which a reinforcing base material is impregnated with a resin have been used as automobile parts for the purpose of reducing the weight of automobile bodies. As a Molding method of a composite material, an RTM (Resin Transfer Molding) Molding method suitable for mass production has attracted attention.

In the RTM molding method, first, the reinforcing base material is disposed in a cavity in a molding die, and the gas in the cavity is exhausted through an exhaust port to be in a reduced pressure (substantially vacuum) state. Then, a resin is injected into the cavity, the reinforcing base material is impregnated with the resin, and the resin is cured to form a composite material. By reducing the pressure in the cavity before injecting the resin into the cavity, the reinforcing base material can be easily impregnated with the resin.

in the RTM molding method as described above, since the resin is injected into the cavity in a reduced pressure state, the injected resin may flow into the exhaust port. This may reduce the suction force of the exhaust gas or may cause an insufficient amount of resin in the cavity, thereby causing an uninsulated portion of the resin in the reinforcing base material.

For example, patent document 1 below discloses a method for molding a composite material using a mold provided with a double seal in order to prevent an injected resin from flowing into an exhaust port. In the method for molding a composite material described in patent document 1, first, a sealing region including a cavity and an outer peripheral region communicating with an outer periphery of the cavity is sealed by a 1 st sealing member, and a gas is discharged from a gas discharge port disposed in the outer peripheral region to bring the inside of the sealing region into a reduced pressure state. Next, the gap between the cavity and the outer peripheral region is sealed by the 2 nd sealing member, and the resin is injected into the cavity and filled therein. Thereby, the resin injected into the cavity is intercepted by the 2 nd sealing member, and therefore the injected resin can be prevented from flowing into the exhaust port.

Disclosure of Invention

Problems to be solved by the invention

However, in the method for molding a composite material of patent document 1, since the resin starts to be injected into the cavity after the cavity and the outer peripheral region are sealed, the gas contained in the resin cannot be removed. As a result, voids are generated in the composite material as a molded article, and the mechanical properties and appearance quality of the molded article may be deteriorated.

the invention aims to provide a composite material forming method and a composite material forming device which can inhibit the generation of pores in the composite material and improve the mechanical property and the appearance quality of the composite material.

Means for solving the problems

in the method for molding a composite material according to the present invention for achieving the above object, first, a reinforcing base material is disposed in a cavity of a molding die including a 1 st die and a 2 nd die, the 2 nd die forming the cavity between the 1 st die and the reinforcing base material. Next, the 1 st mold is relatively moved closer to the 2 nd mold, and a sealing region including the cavity and an outer peripheral region communicating with an outer periphery of the cavity is hermetically sealed by a 1 st sealing member. Then, the operation of sucking the gas from the outer peripheral region and discharging the gas in the sealed region is started, and the resin is injected into a part of the cavity. The 1 st mold is brought closer to the 2 nd mold in a relative manner to close the molding mold, the resin is pressed to fill the cavity, and a 2 nd sealing member liquid-tightly seals a space between the cavity and the outer peripheral region. Then, the operation of sucking the gas from the aforementioned outer peripheral area is stopped.

the composite material forming apparatus according to the present invention for achieving the above object includes: the sealing device comprises a forming die, a 1 st sealing member, a 2 nd sealing member, an exhaust part, a resin injection part and a control part. The forming mold includes a 1 st mold and a 2 nd mold, and the 2 nd mold forms the cavity between the 1 st mold and the 2 nd mold. The 1 st sealing member hermetically seals a sealing region including the cavity and an outer peripheral region communicating with an outer periphery of the cavity between the 1 st die and the 2 nd die. The 2 nd sealing member liquid-tightly seals between the cavity and the outer peripheral region. The exhaust unit sucks gas from the outer peripheral region and exhausts the gas in the sealed region. The resin injection part injects resin into a part of the cavity. The control unit controls a resin injection unit for injecting the resin into the cavity, and controls operations of the molding die, the exhaust unit, and the resin injection unit. The control unit relatively approaches the 1 st mold to the 2 nd mold, and hermetically seals the sealing region with the 1 st sealing member. Then, the operation of the gas exhaust unit is controlled to start the operation of exhausting the gas in the sealing region, and the operation of the resin injection unit is controlled to inject the resin into the cavity. The 1 st mold is brought closer to the 2 nd mold in a relative manner to close the molding mold, the resin is pressed to fill the cavity, and the gap between the cavity and the outer peripheral region is liquid-tightly sealed by the 2 nd sealing member. Then, the operation of sucking the gas from the aforementioned outer peripheral area is stopped.

ADVANTAGEOUS EFFECTS OF INVENTION

according to the method and apparatus for molding a composite material of the present invention, before the space between the cavity and the outer peripheral region is sealed in a liquid-tight manner, the gas is sucked from the outer peripheral region in a state where the cavity and the outer peripheral region are communicated with each other, and the gas in the cavity is discharged. Therefore, the gas contained in the resin injected into the cavity can be discharged from the outer peripheral region in a reduced pressure state to the exhaust port. This can suppress the occurrence of voids in the composite material as a molded article, and improve the mechanical properties and appearance quality of the composite material.

drawings

Fig. 1 is a diagram illustrating a composite material molding apparatus according to an embodiment of the present invention.

fig. 2 is a flowchart illustrating a method of forming a composite material according to an embodiment of the present invention.

Fig. 3A is a diagram schematically showing a state in which a reinforcing base material is disposed in a forming die.

Fig. 3B is a diagram schematically showing a state where the sealing region is hermetically sealed.

Fig. 3C is a view schematically showing the injection of resin into the molding die.

Fig. 3D is a diagram schematically showing a state in which the molding die is clamped after resin injection.

Fig. 3E is a view schematically showing the mold release of the molded article.

Fig. 4 is a diagram schematically showing a comparative example in which resin is injected by providing an injection port in a lower mold.

Fig. 5 is a diagram illustrating an example of a method for manufacturing a reinforcing base material.

Fig. 6 is an enlarged cross-sectional view showing the behavior of the resin with respect to the reinforcing base material in step S5 (fig. 3C).

fig. 7 is a plan view showing an enlarged view of the behavior of the resin with respect to the reinforcing base material in the step S5 (fig. 3C).

fig. 8 is a graph showing the characteristics of the elastic modulus with respect to temperature of the binder resins used in examples and comparative examples.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings attached to the specification. The following description does not limit the scope of protection and the meaning of terms described in the claims. The dimensional ratios in the drawings are exaggerated for convenience of explanation and may be different from actual ratios.

(composite Material)

the composite material 10 is composed of a reinforcing base material 11 and a resin 12. By combining the reinforcing base material 11 and the resin 12, the strength and rigidity are high as compared with a molded article composed of the resin 12 alone. Fig. 3A to 3E and fig. 4 show examples of the composite material 10, the reinforcing base material 11, and the resin 12.

The resin 12 may be made of a thermosetting resin or a thermoplastic resin such as an epoxy resin or a phenol resin.

The reinforcing base material 11 can be formed by laminating woven fabric sheets of carbon fibers, glass fibers, organic fibers, and the like, for example. Fig. 5 is a diagram illustrating an example of a method for manufacturing the reinforcing base material 11. As shown in fig. 5 (a), the reinforcing base material 11 is obtained by cutting a woven fabric sheet 111 of carbon fibers, glass fibers, organic fibers, or the like into a predetermined size, and as shown in fig. 5 (B), a plurality of the woven fabric sheets 111 are stacked to form a fiber base material 112. Then, after the binder resin 113 is applied to the fiber base material 112, the fiber base material is molded into a predetermined shape while the binder resin 113 is cured by using hot press molds M1 and M2, as shown in fig. 5 (C). Thus, the fiber base material 112 is shaped by the binder resin 113, and the reinforcing base material 11 in this state is placed on a lower mold 220 described later. As the binder resin 113, for example, a thermosetting resin or a thermoplastic resin such as an epoxy resin or a phenol resin can be used. Particularly, a material having a softening point Tsp equal to or higher than the molding temperature of the resin 12 described later, specifically, a material having a softening point Tsp equal to or higher than the set temperature of the upper mold 210 or the lower mold 220 is preferable. Such a material is not particularly limited, and a thermosetting epoxy resin and the like can be exemplified.

(Molding apparatus)

Referring to fig. 1, a molding apparatus 100 for a composite material 10 according to the present embodiment will be described.

The molding apparatus 100 includes: a freely openable and closable molding die 200, a 1 st sealing member 310 and a 2 nd sealing member 320, an exhaust part 400, a resin injection part 500, and a control part 600.

The structure of each part of the molding apparatus 100 will be described in detail below.

The forming die 200 includes: a pair of dies including an upper die 210 (corresponding to a "1 st die") and a lower die 220 (corresponding to a "2 nd die") which can move closer to and away from each other. Further, the upper mold 210 is provided with an exhaust port 230 communicating with the exhaust part 400 and an injection port 240 communicating with the resin injection part 500. The forming die 200 forms a die cavity 250 between the upper die 210 and the lower die 220.

In the present specification, the "cavity 250" refers to a cavity (a product cavity) having substantially the same shape as the composite material 10 as a molded article in a clamped state. The side where the upper mold 210 is disposed with respect to the lower mold 220 (upper side in fig. 1) is referred to as "upper side", and the side where the lower mold 220 is disposed with respect to the upper mold 210 (lower side in fig. 1) is referred to as "lower side".

the upper mold 210 is a movable mold that can move toward and away from the lower mold 220. The upper die 210 has: the liquid crystal display device includes a concave portion 211 having a shape recessed upward, a 1 st vertical wall portion 212 having a shape protruding downward so as to surround the concave portion 211, a base portion 213 continuously formed above the concave portion 211 and the 1 st vertical wall portion 212, and a lid portion 214 disposed above the base portion 213. The lid portion 214 of the upper mold 210 is connected to a driving device, not shown, provided with a hydraulic cylinder or the like, for example.

The concave portion 211 has a 1 st molding surface 211S, and the 1 st molding surface 211S is used to form the cavity 250.

the 1 st groove 213A is formed on the outer surface 213S of the base 213, and the 1 st groove 213A is formed in a ring shape over the entire circumference. The 1 st annular sealing member 310 is inserted into the 1 st annular groove 213A.

A 2 nd groove 212A is formed in an outer surface 212S of the 1 st vertical wall 212, and the 2 nd groove 212A is formed in an annular shape over the entire circumference. A 2 nd seal member 320 having the same annular shape is inserted into the 2 nd groove portion 212A having the annular shape.

the lower mold 220 is a fixed mold. The lower die 220 has: a convex portion 221 having a 2 nd molding surface 221S, the 2 nd molding surface 221S cooperating with the 1 st molding surface 211S of the concave portion 211 to form a cavity 250 between the convex portion 221 and the concave portion 211; and a 2 nd vertical wall portion 222 disposed so as to surround the convex portion 221 and the 1 st vertical wall portion 212.

the 2 nd vertical wall portion 222 has an inner side surface 222S formed so as to face the outer side surface 212S of the 1 st vertical wall portion 212 in a state where the upper die 210 is relatively close to the lower die 220 as shown in fig. 1.

The 1 st seal member 310 and the 2 nd seal member 320 are disposed on the outer side surface 212S of the 1 st vertical wall portion 212 and the outer side surface 213S of the base portion 213, respectively, which are surfaces of the upper mold 210 and the lower mold 220 facing each other and along the mold clamping direction (vertical direction in fig. 1) in which the upper mold 210 and the lower mold 220 are relatively brought close to each other. In this manner, the molding die 200 has a vertical slide structure (Japanese patent document: structure for folding り) in which the 1 st seal member 310 and the 2 nd seal member 320 are arranged at different positions in the mold closing direction. Therefore, the sealing function of the 1 st sealing member 310 and the 2 nd sealing member 320 can be performed at different timings by the operation of relatively approaching the upper mold 210 to the lower mold 220.

in a state where the upper mold 210 is relatively brought close to the lower mold 220 as shown in fig. 1 and 3B from the mold opened state shown in fig. 3A and in a state before mold closing, the 1 st sealing member 310 forms a hermetically sealed seal region 270 between the 1 st molding surface 211S, the 2 nd molding surface 221S, the outer side surface 212S of the 1 st vertical wall portion 212 and the inner side surface 222S of the 2 nd vertical wall portion 222. Here, the seal region 270 is a region including the cavity 250 and the outer peripheral region 260 described later. In the state before mold clamping as shown in fig. 1 and 3B, the cavity 250 and the outer peripheral region 260 communicate with each other.

From the state shown in fig. 3B, in a state where the upper mold 210 is further brought closer to the lower mold 220 to close the molding die 200 as shown in fig. 3D, the 2 nd sealing member 320 forms the cavity 250 which is liquid-tightly sealed between the 1 st molding surface 211S and the 2 nd molding surface 221S. Further, in a state where the molding die 200 is clamped, an outer peripheral region 260 located on the outer periphery of the cavity 250 is formed between the 1 st sealing member 310 and the 2 nd sealing member 320. In other words, the 2 nd sealing member 320 liquid-tightly seals between the mold cavity 250 and the peripheral region 260.

In the present specification, the "state in which the molding die 200 is clamped" refers to a state in which: the upper die 210 is relatively approached to the lower die 220 until the shape of the cavity 250 of the forming die 200 becomes substantially identical to the shape of the finally produced composite material 10.

in the present embodiment, as shown in fig. 3D, in a state where the molding die 200 is clamped, the upper die 210 and the lower die 220 have the 1 st abutment surface 210S and the 2 nd abutment surface 220S that abut against each other. In a state where the molding die 200 is clamped, the distance D1 between the 1 st abutment surface 210S and the 2 nd abutment surface 220S becomes 0 (zero) mm. In this state, the size of the cavity 250 is substantially equal to the size of the composite material 10, and there is almost no gap between the 1 st forming surface 211S of the upper die 210 and the composite material 10.

as shown in fig. 3B, in a state before the molding die 200 is clamped, a gap G is formed between the 1 st molding surface 211S of the upper die 210 and the reinforcing base material 11. In this state, the distance D1 between the 1 st contact surface 210S and the 2 nd contact surface 220S differs depending on the shape of the molding die 200, but may be, for example, about 33 mm.

Referring again to fig. 1, the exhaust port 230 is disposed above the outer peripheral region 260. In addition, the volume of the outer peripheral region 260 is configured to be larger than the volume of the resin 12 injected into the cavity 250 in a state where the molding die 200 is clamped.

The injection port 240 is disposed substantially at the center of the cavity 250. That is, the inlet 240 is disposed at a relatively distant position from the outer peripheral region 260.

The material constituting the 1 st sealing member 310 and the 2 nd sealing member 320 is not particularly limited as long as it can seal air-tight or liquid-tight, and an elastic material such as rubber can be used, for example.

The exhaust unit 400 is formed of a known vacuum pump. The exhaust unit 400 is configured to communicate with the exhaust port 230 formed in the upper mold 210, and sucks gas from the outer peripheral area 260 through the exhaust port 230. The exhaust part 400 has a pressure gauge 410 and a valve 420 between it and the exhaust port 230. The pressure gauge 410 is used to measure the suction pressure generated by the exhaust part 400. The degree of vacuum within the sealed region 270 can be adjusted based on the value of the suction pressure. The valve 420 is used to open and close a flow path of air. Thereby, the on/off of the operation by the suction of the exhaust portion 400 can be switched.

resin injection portion 500 is configured to communicate with injection port 240 formed in upper mold 210, and resin 12 is injected into cavity 250 through injection port 240. The resin injection part 500 may be configured by a known pump mechanism.

The control unit 600 controls the operations of the molding die 200, the exhaust unit 400, and the resin injection unit 500. Specifically, referring to fig. 1, the control unit 600 includes: a storage unit 610 including ROM and RAM; an arithmetic unit 620 mainly composed of a CPU; and an input/output unit 630 for transmitting and receiving various data and control commands. The input/output unit 630 is electrically connected to the molding die 200, the exhaust unit 400, and the resin injection unit 500.

(Molding method)

next, a method of molding the composite material 10 according to the present embodiment will be described with reference to fig. 2.

The Molding method of the composite material 10 according to the present embodiment is a Molding method called a Compression Resin Transfer Molding (CRTM) Molding method. In the CRTM molding method, when the resin 12 is injected into the cavity 250, the resin 12 is injected into a part of the cavity 250 in a state where the molding die 200 is not closed and a gap is left between the molding die 200 and the reinforcing base material 11. Then, the molding die 200 is closed, whereby the resin 12 is filled into the cavity 250. This reduces the flow resistance of the resin 12 in the cavity 250, and thus can suppress disturbance of the orientation of the reinforcing base material 11.

As shown in fig. 2, in the molding method of the composite material 10, in summary, the reinforcing base material 11 is placed in the molding die 200 (step S1), and the sealing region 270 is hermetically sealed (step S2). Then, the operation of exhausting the gas in the sealed region 270 is started (step S3), and after the sealed region 270 reaches a predetermined degree of vacuum (threshold) (step S4), the resin 12 is injected into the cavity 250 of the molding die 200 (step S5). Further, the molding die 200 is clamped, and the cavity 250 is liquid-tightly sealed (step S6). Then, the resin 12 is cured (step S7), the operation of discharging the gas is stopped (step S8), and the composite material 10 is released from the molding die 200 (step S9). In each step, the operations of the molding die 200, the exhaust unit 400, and the resin injection unit 500 are controlled by the control unit 600.

the respective steps of the method for molding the composite material 10 will be described in detail below.

In step S1, as shown in fig. 3A, the reinforcing base material 11 is placed on the lower mold 220 of the molding die 200.

in step S2, as shown in fig. 3B, the upper mold 210 is relatively moved toward the lower mold 220, and the 1 st sealing member 310 hermetically seals the sealing region 270. At this time, the molding die 200 is in a state before mold clamping, and the distance D1 between the 1 st contact surface 210S and the 2 nd contact surface 220S is about 33 mm. In this state, a gap G is formed between the 1 st forming surface 211S of the upper mold 210 and the reinforcing base material 11.

In step S3, the valve 420 of the exhaust unit 400 is opened to start the operation of sucking the gas from the outer peripheral region 260 and exhausting the gas in the sealed region 270.

After the sealed region 270 reaches a predetermined degree of vacuum (step 4), as shown in fig. 3C, the resin 12 is injected into a part of the cavity 250 of the molding die 200 (step 5).

since resin 12 is injected into a part of cavity 250, resin 12 in cavity 250 can be prevented from leaking out to outer peripheral region 260 while cavity 250 is in communication with outer peripheral region 260. This can prevent the resin 12 from flowing into the exhaust port 230.

In the present embodiment, the inlet 240 is disposed in the upper mold 210, and therefore the resin 12 flows through the gap G. Therefore, the flow resistance of the resin 12 can be reduced, and the disturbance of the orientation of the reinforcing base material 11 can be suppressed. Further, since the gap G is formed, the injected resin 12 is accumulated in the vicinity of the injection port 240 and does not spread over the entire cavity 250. Therefore, the leakage of the resin 12 to the outer peripheral region 260 can be suppressed.

If the inlet 240A is disposed on the lower mold 220 as in the molding apparatus 100A shown in fig. 4, the reinforcing base material 11 is disposed on the lower side by its own weight, and therefore it is difficult to provide a gap between the 2 nd molding surface 221S of the lower mold 220 and the reinforcing base material 11.

As a result, the flow resistance of the resin 12 increases, and there is a possibility that the orientation of the reinforcing base material 11 is disturbed (a portion surrounded by a broken line in fig. 4). This impairs the appearance quality of the composite material 10 as a molded article.

It is also conceivable to remove the reinforcing base material 11 disposed near the injection port 240 in advance to reduce the flow resistance of the resin 12, but the position of the injection port 240 is determined in accordance with the position of the removal of the reinforcing base material 11 in accordance with the shape of the molded article, and therefore the position of the injection port 240 is limited.

On the other hand, by disposing the inlet 240 on the upper mold 210 as in the present embodiment, the gap G can be formed. By allowing the resin 12 to flow into the gap G, the flow resistance of the resin 12 can be reduced. This can suppress disturbance of the orientation of the reinforcing base material 11, and thus the appearance quality of the composite material 10 as a molded article is improved.

in addition, it is not necessary to remove the reinforcing base material 11 disposed near the injection port 240 in advance. Thus, the position where the injection port 240 is disposed is not limited by the shape of the molded article, and therefore the position of the injection port 240 can be set to an optimum position for impregnating the reinforcing base material 11 with the resin 12. As a result, the time for injecting the resin 12 can be shortened, and the overall cycle time can be shortened.

Further, the injection port 240 is disposed at substantially the center of the cavity 250, and therefore is relatively distant from the outer peripheral region 260. Therefore, the resin 12 can be suppressed from flowing into the outer peripheral region 260.

In step 5, the exhaust unit 400 maintains the operation of exhausting the gas in the seal region 270. Since the exhaust port 230 is disposed above the outer peripheral region 260, the resin 12 injected into the cavity 250 can be prevented from flowing into the exhaust port 230.

In step S6, as shown in fig. 3D, the molding die 200 is clamped, and the cavity 250 and the outer peripheral region 260 are liquid-tightly sealed by the 2 nd sealing member 320.

When the molding die 200 is closed, the gap G between the 1 st molding surface 211S of the upper die 210 and the reinforcement base material 11 is compressed, and the resin 12 deposited in the gap G is pressed to impregnate the entire reinforcement base material 11. At the same time, since the periphery of cavity 250 is liquid-tightly sealed, resin 12 can be more reliably prevented from leaking from cavity 250 to outer peripheral region 260.

Further, since the molding die 200 has the concave portion 211 in the upper die 210 and the convex portion 221 in the lower die 220, and the cavity 250 is formed between the convex portion 221 and the concave portion 211, the resin 12 can be easily spread and impregnated into the entire reinforcing base material 11 by the self weight of the resin 12.

The exhaust port 230 is disposed above the outer peripheral region 260. In addition, the volume of the outer peripheral region 260 is configured to be larger than the volume of the resin 12 injected into the cavity 250 in a state where the molding die 200 is clamped. Therefore, even if the resin 12 leaks out to the outer peripheral region 260 after the mold 200 is closed, the resin 12 can be prevented from flowing into the exhaust port 230.

In step S7, resin 12 is cured. When the resin 12 is a thermosetting resin, the molding die 200 can be heated by using a heating device such as a heater, for example, to cure the resin 12.

In step S8, the valve 420 of the exhaust unit 400 is closed to stop the operation of sucking (discharging) the gas from the outer circumferential region 260. In other words, the exhaust unit 400 maintains the operation of exhausting the gas during the steps 3 to 7. Before the space between the cavity 250 and the outer peripheral region 260 is liquid-tightly sealed in step 6, gas is sucked from the outer peripheral region 260 and the gas in the cavity 250 is exhausted in a state where the cavity 250 and the outer peripheral region 260 communicate with each other. Therefore, the gas contained in the resin 12 injected into the cavity 250 can be discharged from the outer peripheral region 260 in a reduced pressure state to the exhaust port 230. This can suppress the occurrence of voids in the composite material 10 as a molded article, and improve the mechanical strength and appearance quality.

In step S7, as shown in fig. 3E, the upper mold 210 is moved away from the lower mold 220 to open the molding die 200, and the composite material 10 as a molded product is released from the mold.

In the present embodiment, the composite material 10 has a relatively simple shape, but is not limited thereto. When the composite material 10 is manufactured as a frame component such as a pillar or a front side member used for an automobile body, or an outer panel component such as a roof or an engine hood, for example, it has a more complicated shape corresponding thereto.

In step S5, after the sealed region 270 has reached a predetermined degree of vacuum, the resin 12 is injected into a part of the cavity 250 of the mold 200, as shown in fig. 3C. Fig. 6 is an enlarged cross-sectional view showing the behavior of the resin 12 with respect to the reinforcing base material 11 in the step S5 (fig. 3C), and fig. 7 is a plan view in the same case. First, as shown in fig. 6 (a) and 7 (a), when the resin 12 is injected into a part of the cavity 250 of the molding die 200, since the injection pressure of the resin is high, if the shape retention ability of the fiber base material 112 of the reinforcing base material 11 is weak, the fibers of the fiber base material 112 of the reinforcing base material 11 may spread in two directions as shown by arrows and cause displacement when the resin 12 is impregnated into the reinforcing base material 11 in the vicinity facing the injection port 240 as shown in fig. 6 (B) and 7 (a). As a result, as shown in fig. 7 (B), if the fibers of the fiber base material 112 spread in a direction perpendicular to the fiber direction and are unevenly distributed, and a fiber deviation θ occurs, the tensile strength of the composite material 10 as a final product decreases. Further, the flow resistance of the resin 12 becomes high due to the fiber deviation of the fiber base material 112, that is, if the deviated fibers are unevenly distributed, the resin 12 becomes difficult to flow, and if so, voids B are generated inside the composite material 10 as shown in fig. 6 (C), and the compressive strength of the composite material 10 as a final product is lowered.

This behavior is also called a finger phenomenon (fingering phenomenon), and one of the reasons is considered to be to enhance the heat resistance of the base material 11. That is, this is because, although the reinforcing base material 11 is placed on the lower mold 220 set at the molding temperature in step S5, if the softening temperature Tsp of the binder resin 113 for maintaining the shape of the reinforcing base material 11 is lower than the molding temperature, specifically, lower than the temperature of the lower mold 220, the reinforcing base material 11 is softened when the resin 12 is injected in step S5, and the shape retaining ability of the fiber base material 112 is lowered.

Therefore, the present inventors used carbon fibers (Zoltec PX35, manufactured by tokyo corporation) as the woven fabric sheet 111, laminated while aligning the fiber directions in the same direction, to obtain a fiber base material 112(UD0 °), and the fiber base material 112 was laminated at a ratio of 15g/m²The coating amount of (A) was 1, and a thermosetting epoxy resin having a softening temperature Tsp of 130 ℃ was applied as the binder resin 113The test piece thus obtained was prepared by heat curing at 40 ℃ for 1 to 2 minutes, and this was taken as an example. As comparative example, test pieces were prepared under the same conditions as in example except that a thermoplastic epoxy resin having a softening temperature of 80 ℃ was used.

Each of the test pieces of examples and comparative examples was subjected to the steps S1 to S9 in FIG. 2 under conditions of a molding temperature of 120 ℃ and a molding pressure of 8 MPa. The fiber deflection θ (fig. 7B), the porosity (volume%), the reduction rate (%) of tensile strength, and the reduction rate (%) of compressive strength of the test pieces of the obtained composite material 10 were measured, respectively, to obtain the results shown in table 1. The reduction rate of the tensile strength of the comparative example is a reduction rate of the tensile strength reduction of the example, and the reduction rate of the compressive strength of the comparative example is a reduction rate of the compressive strength reduction of the example. Fig. 8 is a graph showing the characteristics of the elastic modulus versus temperature of the binder resin 113 used in the examples and comparative examples. It is understood that the binder resin 113 used in the examples shows a small decrease in elastic modulus until the softening point Tsp at 120 ℃ exceeding the molding temperature is 130 ℃, whereas the binder resin 113 used in the comparative examples shows a decrease in elastic modulus from the softening point Tsp at 120 ℃ exceeding the molding temperature of 80 ℃ and shows a much lower elastic modulus at 120 ℃ than in the examples.

[ Table 1]

Watch l

As described above, it was confirmed that the tensile strength is reduced when the fiber deviation is large, and the compressive strength is reduced when the porosity is large, and that the reduction of the tensile strength and the compressive strength is suppressed by using a material having a resin softening point of the lower mold 220 or higher as the binder resin 113 of the reinforcing base material 11.

As described above, according to the method for molding the composite material 10 and the apparatus 100 for molding the composite material 10 of the present embodiment, first, the reinforcing base material 11 is disposed in the molding die 200 including the upper die 210 (corresponding to the "1 st die") and the lower die 220 (corresponding to the "2 nd die"), and the lower die 220 forms the cavity 250 between the upper die 210 and the lower die 220. Next, the upper mold 210 is relatively moved toward the lower mold 220, and the sealing region 270 including the cavity 250 and the outer peripheral region 260 communicating with the outer periphery of the cavity 250 is hermetically sealed by the 1 st sealing member 310. Then, the operation of sucking the gas from the outer peripheral region 260 and discharging the gas in the sealing region 270 is started, and the resin 12 is injected into a part of the cavity 250. The upper mold 210 is brought closer to the lower mold 220 to close the molding die 200, the resin 12 is pressed and filled into the cavity 250, and the cavity 250 and the outer peripheral region 260 are liquid-tightly sealed by the 2 nd sealing member 320. Then, the operation of sucking the gas from the outer peripheral area 260 is stopped.

according to the manufacturing method of the composite material 10 thus configured, before the cavity 250 and the outer peripheral region 260 are liquid-tightly sealed, the gas is sucked from the outer peripheral region 260 and the gas in the cavity 250 is discharged in a state where the cavity 250 and the outer peripheral region 260 communicate with each other. Therefore, the gas contained in the resin 12 injected into the cavity 250 can be discharged from the outer peripheral region 260 in a reduced pressure state to the exhaust port 230. This can suppress the occurrence of voids in the composite material 10 as a molded article, and improve the mechanical properties and appearance quality of the composite material 10.

The 1 st and 2 nd seal members 310 and 320 are disposed on the surfaces 212S and 213S along the mold clamping direction in which the upper mold 210 and the lower mold 220 are relatively brought close to each other, among the surfaces of the upper mold 210 and the lower mold 220. Therefore, the sealing function of the 1 st sealing member 310 and the 2 nd sealing member 320 can be performed by the operation of relatively approaching the upper mold 210 to the lower mold 220. By adjusting the arrangement of the 1 st sealing member 310 and the 2 nd sealing member 320, a gap G can be formed between the forming die 200 and the reinforcing base material 11. By causing the resin to flow through the gap G, the flow resistance of the resin 12 in the cavity 250 can be reduced, and the disturbance of the orientation of the reinforcing base material 11 can be suppressed. This can further improve the mechanical properties and appearance quality of the composite material 10.

The 1 st mold is an upper mold 210, and the 2 nd mold is a lower mold 220. When the gas is sucked from the outer peripheral area 260, the gas is sucked through the gas discharge port 230 arranged on the upper side of the outer peripheral area 260 in the upper die 210. The volume of the outer peripheral region 260 is configured to be larger than the volume of the resin 12 injected into the cavity 250 in a state where the molding die 200 is clamped. Therefore, even if the resin 12 leaks out to the outer peripheral region 260 after the mold 200 is closed, the resin 12 can be prevented from flowing into the exhaust port 230.

Further, the upper mold 210 has a concave portion 211, the concave portion 211 having a shape recessed upward, and the lower mold 220 has a convex portion 221, the convex portion 221 forming a cavity 250 with the concave portion 211. This makes it possible to easily spread and impregnate the resin 12 into the entire reinforcing base material 11 by the weight of the resin 12.

Further, the injection port 240 is disposed in the upper mold 210, and the resin 12 is injected into the cavity 250 through the injection port 240. This makes it possible to easily expand and impregnate the resin 12 into the entire reinforcing base material 11 by the weight of the resin 12. In addition, since the position where injection port 240 is disposed is not limited by the shape of the molded article, as compared with the case where injection port 240 is disposed in lower mold 220, the position of injection port 240 can be set to an optimum position for impregnating reinforcing base material 11 with resin 12. As a result, the time for injecting the resin 12 can be shortened, and the overall cycle time can be shortened.

Further, by using a material having a softening point Tsp equal to or higher than the molding temperature or the temperature of the 1 st mold (upper mold 210) or the 2 nd mold (lower mold 220), for example, a thermosetting epoxy resin or the like as the binder resin 113 of the reinforcing base material 11, fiber displacement due to a finger phenomenon that may occur at the time of injection of the resin 12 is suppressed, and thus a decrease in tensile strength or compressive strength is suppressed.

The method and apparatus for molding a composite material have been described above with reference to the embodiments, but the present invention is not limited to the configurations described in the embodiments, and can be modified as appropriate based on the descriptions of the claims.

for example, the shape of the molding dies 210 and 220 forming the cavity is not limited to the shape described in the embodiment, and may be, for example, a form in which the 1 st die (upper die) 210 has a convex portion and the 2 nd die (lower die) 220 has a concave portion corresponding to the convex portion, a form in which both the 1 st die (upper die) 210 and the 2 nd die (lower die) 220 have a concave portion, or a flat cavity 250 having no concave and convex portions.

In addition, in the above embodiment, the 1 st sealing member 310 and the 2 nd sealing member 320 are provided on the 1 st mold (upper mold) 210, but the 1 st sealing member 310 and the 2 nd sealing member 320 may be provided on the 2 nd mold (lower mold) 220, or one of the 1 st sealing member 310 and the 2 nd sealing member 320 may be provided on the 1 st mold (upper mold) 210 and the other may be provided on the 2 nd mold (lower mold) 220. The 1 st and 2 nd sealing members 310 and 320 are not limited to the structure of the surfaces arranged on the surfaces of the 1 st and 2 nd molds 210 and 220 facing each other along the mold clamping direction in which the 1 st and 2 nd molds 210 and 220 are relatively brought close to each other, and may be arranged on the contact surfaces (mold clamping surfaces) that come into contact with each other as the 1 st and 2 nd molds 210 and 220 come close to each other.

Description of the reference numerals

10. A composite material; 11. a reinforcing substrate; 111. a fabric sheet; 112. a fibrous base material; 113. a binder resin; m1, M2, hot pressing die; 12. a resin; 100. a forming device; 200. a forming die; 210. an upper die (1 st die); 220. a lower die (2 nd die); 230. an exhaust port; 240. an injection port; 250. a mold cavity; 260. a peripheral region; 270. a sealing region; 310. 1 st sealing member; 320. a 2 nd sealing member; 400. an exhaust section; 500. a resin injection part; 600. a control unit.