JP2010143162A - Manufacturing process of resin molded article, and resin molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable suppression of creeping of resin molded article. <P>SOLUTION: A resin molded article 1 is molded by a fiber-reinforcing composite containing a fiber-reinforcing fiber comprising a carbon fiber using a thermosetting resin, i.e. an epoxy resin, as a matrix. An inner part of a container 2 is heated at a pre-determined temperature by a heating device. The resin molded article 1 is held on a supporting material 3 with which the container 2 is equipped. A compressing device 4 falls down to the resin molded article 1 on the supporting material 3 so as to compress the resin molded article 1, whereby pressure is charged to the resin molded article 1. After pressing for a pre-determined time, the compressing device 4 is released from the resin molded article 1 to stop pressing. The pressed resin molded article 1 contains a deforming part 5 formed by pressing. The deforming part 5 in the resin molded article 1 after pressing is deformed so as to suppress creep after bonding. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a resin molded body, and more particularly to a method for producing a resin molded body suitable for use in a fastened state and a resin molded body produced by the method.

  Resin moldings are widely used as lightweight structural materials. The structural material is rarely used alone and is used by being joined to other parts. As a joining method, there are many fastenings using bolts. However, when the resin molded body is directly fastened with bolts, there is a problem that the axial force of the bolt is reduced and rattling occurs due to the deformation of the resin molded body due to creep.

  As a countermeasure, as disclosed in Patent Document 1, as a means for fastening the resin material and the metal material, a metal part is inserted into the resin material, and a bolt penetrated through a hole opened in the metal part. There is a way to conclude. According to Patent Document 1, a metal pipe is insert-molded into a flange that is also a resin material that is integrally formed with a housing made of a resin material that holds a rotation detection unit of an in-vehicle engine. When the metal pipe is fastened with a bolt, the rotation detector is fastened with an engine body made of a metal material.

  Patent Document 2 discloses a means for suppressing creep deformation of a fiber reinforced composite material (hereinafter simply referred to as a composite material) using a resin as a matrix. Patent Document 2 proposes a method of directly fastening a fiber-reinforced composite material by forming a fiber volume content in a peripheral portion of a hole through which a bolt is inserted higher than that of other portions in the composite material.

According to Patent Document 2, after the reinforcing fibers are arranged in the lower mold of the molding die, a part of the reinforcing fibers is compressed by the convex portions by closing the upper mold of the molding die having the convex portions. Therefore, the fiber volume content of the reinforcing fiber in the portion corresponding to the convex portion is higher than in the other portions. Next, a thermosetting resin is injected into the molding die, the reinforcing fibers are impregnated with the thermosetting resin, and then heated to cure the thermosetting resin. In the resin molded body molded by the above method, a hole for penetrating a bolt is formed in a portion having a high fiber volume content.
JP 2006-275270 A JP 2007-268941 A

  In the case of inserting a metal pipe into a flange made of a resin molded body as in Patent Document 1, since the metal pipe supports the stress due to the fastening of the bolt, the loosening of the bolt can be suppressed. However, since the difference in thermal expansion coefficient between the metal pipe and the resin molded body is large, there is a problem that residual stress is generated, causing deformation and cracks. Moreover, since the press-fitting precision of the said metal pipe and the processing precision of a hole are required, cost starts. Furthermore, there is a drawback that the weight is increased by the amount of the metal pipe.

  As in Patent Document 2, a method of heating and curing after injecting a resin into a molding die in order to increase the fiber volume content around the bolt through hole is the same as the conventional resin molding method. Therefore, the method of Patent Document 2 cannot sufficiently obtain the creep suppressing effect of the resin molded body, and has not led to a fundamental solution for suppressing the creep of the composite material.

  This invention aims at suppression of the creep in a resin molding.

  The present invention of claim 1 is characterized in that, in a resin molded body having a fastening portion, a region including at least the fastening portion of the resin molded body is pressurized and the pressurized state is maintained for a predetermined time.

  According to this invention of Claim 1, in the area | region where the resin molding was pressurized, it will be in the state where creep occurred previously before fastening, and it becomes possible to suppress the creep which arises after fastening. Moreover, in this invention, the resin molding which has a creep inhibitory effect can be manufactured irrespective of the presence or absence of a reinforced fiber.

  The present invention according to claim 2 is characterized in that the resin molded body is a fiber-reinforced composite material. Accordingly, since the amount of the resin that causes creep is reduced by the amount of the reinforcing fiber, the creep suppressing effect of the resin molded body can be enhanced as compared with the case without the reinforcing fiber.

  The present invention according to claim 3 is characterized in that the resin molding is a thermosetting resin. The thermosetting resin is less deformed by heating after curing. Therefore, it becomes possible to produce the resin molded body that is not easily deformed even when heated.

  The present invention according to claim 4 is characterized in that the resin molded body is pressed in a state of being heated to a predetermined temperature. Therefore, compared with a case where the resin molded body is pressed at room temperature, a short time is added. The resin molded body can be manufactured in the pressure holding time.

  The present invention according to claim 5 is characterized in that a through hole for fastening is formed in the resin molded body after the pressurization, and therefore, compared with a case where the through hole is opened before pressurization. The dimensional accuracy of the through hole can be improved.

  The present invention according to claim 6 is characterized in that a through hole for fastening is formed in the resin molded body before the pressurization. Therefore, compared with the case where the through hole is formed in the resin molded body after the pressurization, the through hole can be formed with a weak force.

  The present invention according to claim 7 is characterized in that in the resin molded body having a fastening portion, at least a region including the fastening portion has a deformed portion formed by pressure after resin molding. For this reason, the deformed portion of the resin molded body is in a state where the deformation has occurred in advance before fastening, and deformation due to creep of the portion after fastening can be reduced.

  The invention of claim 8 is characterized in that the resin molded body is a fiber reinforced composite material. Therefore, since the amount of the resin itself that causes creep is reduced by the amount containing the reinforcing fiber, the creep suppressing effect of the resin molded body can be enhanced as compared with the case without the reinforcing fiber.

  The present invention according to claim 9 is characterized in that the resin molded body is a thermosetting resin, and therefore the resin molded body is hardly deformed by heating.

  The present invention can suppress creep in the resin molded body.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 schematically show a manufacturing apparatus and a manufacturing method of a resin molded body, and FIG. 3 schematically shows a fastening method of the resin molded body. For convenience, some dimensions are exaggerated for easy understanding. This is the same in other embodiments.

  The resin molded body 1 is molded from a fiber-reinforced composite material using an epoxy resin, which is a thermosetting resin, as a matrix and carbon fibers as reinforcing fibers. The apparatus for manufacturing the resin molded body 1 is configured as shown in FIG. The inside of the container 2 is heated to a predetermined temperature by a heating device such as a heater (not shown). A support 3 is provided in the container 2, and the resin molded body 1 is fixed on the support 3. A pressurizing device 4 is provided on the upper portion of the support 3 in the container 2. The pressurizing device 4 can be moved up and down by a lifting device (not shown). The resin molded body 1 is pressurized by the pressure device 4 in a state where the pressure device 4 is sufficiently lowered. The area where the pressure device 4 is in contact with the resin molded body 1 is sufficiently larger than the area of the fastening through-hole 6 formed in the resin molded body 1 described later. FIG. 3 shows a state in which the resin molded body 1 manufactured by the above method is used by being fastened to another component 7. The resin molded body 1 is overlaid on the other part 7, and bolts 8 are passed through the through hole 6 and through holes (not shown) of the other parts 7 from the resin molded body 1 side, and are fastened and fixed with nuts 9.

  Next, the manufacturing method of the resin molding 1 is demonstrated based on FIG. 1 (a), (b) and FIG. 2 (a), (b). As shown in FIG. 1A, the resin molded body 1 is fixed to the upper part of the support base 3 in the container 2. The inside of the container 2 is heated to a predetermined temperature. As shown in FIG. 1B, the pressure device 4 is lowered with respect to the resin molded body 1 on the support base 3, and pressure is applied to the resin molded body 1 by compressing the resin molded body 1. After the pressurization state is maintained for a predetermined time, the pressurizer 4 is raised as shown in FIG. The pressed resin molded body 1 has a deformed portion 5 formed by pressing. A through-hole 6 for fastening is formed on the resin molded body 1 after being taken out from the container 2 as shown in FIG. The through hole 6 is formed by a tool such as a drill in the approximate center of the deformed portion 5 of the resin molded body 1.

  The operation of the first embodiment configured as described above will be described with reference to FIG. FIG. 4 shows the change in the amount of strain due to creep in the molded resin body 1 after molding. Generally, the amount of distortion due to creep of the molded resin 1 generated per unit time is greatly generated as indicated by X in the initial time zone indicated by AB. Thereafter, the amount of strain due to creep in the same time zone BC is greatly reduced as shown by Y and is slightly generated. The resin molded body 1 is in a state in which the stress relaxation becomes slight after the time C has elapsed, and the amount of strain due to creep hardly occurs.

  When the pre-pressurized resin molded body 1 shown in FIG. 1A is fastened as it is, the strain occurrence state of the resin molded body 1 corresponds to point A in FIG. Therefore, after the fastening, the resin molded body 1 generates a large strain indicated by X over time until the point B in FIG. In contrast, the resin molded body 1 in the first embodiment is preliminarily pressed for a predetermined time, thereby causing anisotropy in the molecular skeleton structure of the resin and causing a creep corresponding to X. That is, the resin molded body 1 is deformed in the same state as when the time has already passed to the point B in a state before being used for fastening. Therefore, the resin molded body 1 after pressurization does not include the large strain that occurs in the initial time zone A-B indicated by X in FIG. 4 in the strain due to creep after fastening. Accordingly, the strain caused by creep that occurs after the resin molded body 1 is fastened is extremely small as compared to the case where the resin molded body 1 before pressurization is fastened. Since the deformation | transformation part 5 in the resin molding 1 has produced the creep previously by pressurization, the creep distortion after fastening is suppressed.

  In FIG. 3, the deformed portion 5 including the through hole 6 in the resin molded body 1 is deformed by pressure before being fastened by the bolt 8 in advance. Therefore, the distortion due to creep of the deformed portion 5 in the resin molded body 1 after fastening is smaller than when the resin molded body 1 before pressing is fastened. Therefore, when the bolt 8 is inserted into the through-hole 6 formed in the deformed portion 5 and fastened to the other component 7, the creep of the resin molded body 1 can be suppressed, and the decrease in the axial force of the bolt 8 is suppressed. .

The first embodiment described above has the following operational effects.
(1) In the resin molded body 1, the region having the through-hole 6 is pressurized by the pressure device 4, and the deformed portion 5 is formed by holding the pressure state for a predetermined time. Since the region of the deformed portion 5 is deformed by pressurization and becomes similar to a state in which creep has occurred in advance before being fastened, it is possible to suppress creep that occurs after fastening. Moreover, since the resin molded body 1 does not require a separate part for the countermeasure against creep in the through-hole 6, it can be manufactured at low cost and the workability is improved.

(2) The resin molded body 1 is a fiber reinforced composite material. Therefore, since the amount of the resin itself that causes creep is reduced by the amount containing the reinforcing fiber, the creep suppressing effect of the resin molded body can be enhanced as compared with the case without the reinforcing fiber.

(3) The matrix of the resin molded body 1 is a thermosetting resin. Therefore, it has excellent heat resistance against heating after curing, is hard, and hardly deforms.

(4) The resin molded body 1 is heated to a predetermined temperature in the container 2 when being pressurized by the pressure device 4. Therefore, the resin molded body 1 can be manufactured in a shorter time than when the resin formed body 1 is pressurized at room temperature.

(5) The resin molded body 1 is formed with a through hole 6 for fastening after being pressed. Therefore, as in a second embodiment to be described later, the drilling can be performed with higher accuracy than when the through-hole 6 is opened before pressurization.

(Second Embodiment)
In the second embodiment shown in FIG. 5 and FIG. 6, the fastening through-hole 6 is formed before the resin molded body 1 in the first embodiment is pressurized. The same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5A, the resin molded body 1 has a through hole 6 for fastening before being pressed. With respect to the resin molded body 1 fixed on the support base 3 in the container 2 heated to a predetermined temperature, the pressurizing device 4 descends as shown in FIG. Pressure is applied to the area containing the holes 6. After the pressurization state is maintained for a predetermined time, the pressurizer 4 is separated from the resin molded body 1 as shown in FIG. The pressurized resin molded body 1 is taken out from the container 2 to produce a resin molded body 1 as shown in FIG.

Therefore, according to this embodiment, the following effects can be obtained in addition to the effects similar to (1) to (5) in the first embodiment.
(1) The through-hole 6 for fastening is formed in the resin molding 1 before pressurization. Therefore, the formation of the through hole 6 is easier than the case where the through hole 6 is formed in the resin molded body 1 after pressurization.

The present invention is not limited to the configuration of each of the embodiments described above, and various modifications are possible within the scope of the gist of the present invention, and can be implemented as follows.
(1) The area where the resin molded body 1 is pressurized is not limited to the surface around the through hole 6 into which the bolt 8 is inserted, but may be the entire surface of the resin molded body 1 on the side where the bolt 8 is inserted. .

(2) The method of pressurizing the region of the deformable portion 5 and holding the pressurized state for a predetermined time is other than the method of continuously applying a constant pressure for a predetermined time as shown in the first embodiment or the second embodiment. In addition, for example, a method may be used in which the applied pressure is changed, for example, the applied pressure is gradually or rapidly increased or gradually or rapidly decreased.

(3) In the method of pressurizing the region of the deformable portion 5 and holding the pressurized state for a predetermined time, the time for holding the pressure is fixed in advance as shown in the first embodiment or the second embodiment. In addition to the method, the predetermined time may be variable. For example, a detection device that detects the amount of deformation caused by pressurization and a control device that controls the detected signal, the deformation amount per unit time is calculated by the control device, and the amount of deformation per unit time is determined. A method of holding the pressurization time until the amount is below the fixed amount may be used. Further, a method may be used in which the control unit calculates a deformation amount from the start of pressurization and maintains the pressurization state until the deformation amount from the start of pressurization reaches a predetermined amount.

(4) In the method of manufacturing the resin molded body 1 by holding the pressurized state shown in the first or second embodiment for a predetermined time, for example, after applying pressure to the resin molded body 1, the pressure is once released. Then, after the deformable portion 5 has been restored to some extent, a method of manufacturing the resin molded body 1 by repeatedly performing the pressurization state and the release state once or a plurality of times during a predetermined time, such as pressurizing again.

(5) As shown in the first or second embodiment, the resin molded body 1 is, for example, a phenol resin, a melamine resin, a urea resin, an unsaturated polyester resin, an alkyd resin, a polyurethane resin in addition to an epoxy resin as a thermosetting resin. Thermosetting polyimide or the like may be used. Moreover, the change in the strain amount due to creep in the resin molded body 1 shows a tendency similar to that in FIG. 4 in other resins than the epoxy resin.

(6) As shown in the first embodiment, the resin molded body 1 may be made of a resin material without reinforcing fibers, instead of being a fiber-reinforced composite material including reinforcing fibers and a resin as a matrix.

(7) As shown in Embodiment 1, the resin molded body 1 is made of, for example, glass fiber, boron fiber, aramid fiber, polyethylene fiber, zylon, etc. in addition to carbon fiber as the reinforcing fiber instead of using carbon fiber as the reinforcing fiber. It may be used.

(8) The resin molded body 1 is, for example, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polytetrafluoroethylene, ABS resin, AS resin, acrylic resin, polyamide, polyacetal, polycarbonate instead of thermosetting resin. , Modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyethersulfone, amorphous polyarylate, liquid crystal polymer, polyetheretherketone, thermoplastic polyimide, polyamideimide Alternatively, a thermoplastic resin such as methyl methacrylate may be used. Further, the change in the amount of strain due to creep in the resin molded body 1 shows a tendency similar to that in FIG. 4 in the thermoplastic resin.

(9) As a method of fastening the resin molded body 1, instead of using the bolt 8 or the nut 9 as shown in FIG. In these methods, a hole is not necessarily formed in the fastening portion of the resin molded body 1.

(10) The other parts 7 to be fastened to the resin molded body 1 may be parts having a different shape such as a bar or a column instead of using a plate-like one as shown in FIG. Moreover, the object to which the resin molded body 1 is fastened is not limited to the other components 7, and may be rocks that constitute walls, floors, or the ground.

(11) As shown in the first or second embodiment, the method of forming the through hole 6 in the resin molded body 1 is a method of forming a resin material instead of drilling with a tool such as a drill. In this case, for example, a method of obtaining the resin molded body 1 having holes by using a molding die having a donut shape, a hollow shape, or a convex portion may be used.

(12) The method of forming the through-hole 6 in the resin molded body 1 is punching instead of drilling the molded resin with a tool such as a drill as shown in the first or second embodiment. Processing, water jet processing, or the like may be performed. Further, after drilling, external processing such as deburring around the through-hole 6 and cutting unnecessary portions may be performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating a method for producing a resin molded body in the first embodiment, (a) is a schematic diagram illustrating a resin molded body before pressurization, and (b) is a resin molded body during pressurization. It is a schematic diagram. These are the schematic diagrams explaining the manufacturing method of the resin molding in 1st Embodiment, (a) is a schematic diagram which shows the resin molding after pressurization, (b) is the resin molding after pressurization, It is a schematic diagram which shows what the through-hole for fastening was formed. These are schematic sectional drawings explaining the fastening method of a resin molding. These are graphs showing changes in the amount of strain due to creep in a resin molded body. These are the schematic diagrams explaining the manufacturing method of the resin molding in 2nd Embodiment, (a) is a schematic diagram which shows the resin molding before pressurization, (b) shows the resin molding under pressure. It is a schematic diagram. These are the schematic diagrams explaining the manufacturing method of the resin molding in 2nd Embodiment, (a) is a schematic diagram which shows the resin molding after a pressurization, (b) is after the pressurization taken out from the container It is a schematic diagram which shows a resin molding.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin molding 2 Container 3 Support stand 4 Pressurization apparatus 5 Deformation part 6 Through-hole 7 Other parts 8 Bolt 9 Nut

Claims (9)

In a resin molded body having a fastening portion,
A method for producing a resin molded body comprising pressurizing a region including at least a fastening portion of the resin molded body and maintaining the pressurized state for a predetermined time.   The method for producing a resin molded body according to claim 1, wherein the resin molded body is made of a fiber-reinforced composite material.   The method for producing a resin molded body according to claim 1, wherein the resin molded body is made of a thermosetting resin.   The method for producing a resin molded body according to any one of claims 1 to 3, wherein the resin molded body is pressurized while being heated to a predetermined temperature.   The method for producing a resin molded body according to any one of claims 1 to 4, wherein a through hole for fastening is formed in the resin molded body after the pressurization.   The method for producing a resin molded body according to any one of claims 1 to 4, wherein a through hole for fastening is formed in the resin molded body before the pressurization. In a resin molded body having a fastening portion,
A resin molded body comprising a deformed portion formed by pressure after resin molding in a region including at least a fastening portion of the resin molded body.   The resin molded body according to claim 7, wherein the resin molded body is a fiber-reinforced composite material.   The resin molded body according to claim 7 or 8, wherein the resin molded body is a thermosetting resin.