JP2004082470A - Resin component with reinforced weld part and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin component with a reinforced weld part obtained by reinforcing the weld part of an injection-molded product and firmly binding a reinforcing member and a resin material, and a method for manufacturing this resin component. <P>SOLUTION: The resin component 1 with a reinforced weld part has a weld part which is reinforced by incorporating an almost sheet-like resin strip 2 formed of a glass mat-reinforced polypropylene resin in the weld part where the association of glass-reinforced polypropylene resins as a resin material to be injected, occurs. Therefore, the weld part and the other section can be formed to have an almost equal strength. In addition, the method comprises forming the resin material after previously arranging the resin strip 2 at a position where the association of the resin materials inside mold halves 4 and 4' occurs and injecting the resin material. Further, the resin strip 2 and the resin material to be injected are firmly bound because the polypropylene resin as a matrix resin is constituted of the same kind of the resin, and the resin strip 2 and the resin material heated by a heating furnace 3 melt together in a softened state. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a weld part reinforced resin part and a method of manufacturing the same, and more particularly to a weld part reinforced resin part that improves the strength of a weld part generated in an injection molded product and a method of manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, methods for manufacturing a part using a glass fiber reinforced thermoplastic resin include compression molding using a glass mat reinforced polypropylene resin (GMT) and injection molding using a long glass fiber reinforced polypropylene resin or a short glass fiber reinforced polypropylene resin. .
[0003]
Therefore, resin-based parts that require high strength may be formed by compression molding, but compression-molded products require secondary processing such as cutting such as drilling or deburring after molding. .
In the case where the resin material is formed by injection molding, a weld portion where the resin material injected into the mold meets is generated. This weld is described in detail below.
[0004]
For example, as shown in FIG. 6, the injection molded product is employed in an inner panel 30 that protects a back door (not shown) provided at the rear of the vehicle.
The inner panel 30 has a substantially trapezoidal, substantially sheet-like shape, and has a substantially rectangular upper opening 30a and a lower opening 30b at the upper and lower portions, respectively. Further, since the inner panel 30 is a large-sized component, a gate portion 31 for injecting a glass fiber reinforced polypropylene resin as a resin material is formed at one place above the upper opening 30a and at two places below the upper opening 30a. .
[0005]
When the glass fiber reinforced polypropylene resin is injected from the plurality of gate portions 31 as shown by arrow D, weld portions 32 (broken line portions) where the glass fiber reinforced polypropylene resin meets are substantially provided on both sides of the upper opening 30a. It is formed so as to extend in the horizontal direction and to extend substantially vertically below the upper opening 30a. Further, the injected glass fiber reinforced polypropylene resin is divided in two directions above the lower opening 30b as shown by an arrow C, and the welded portion 32 '(a wavy line) where the divided glass fiber reinforced polypropylene resin again associates. ) Is formed below the lower opening 30b so as to extend substantially vertically.
[0006]
As shown in FIG. 7, the glass fibers are oriented in the same direction, and only the matrix resin is laminated from the surface layer to the inside. There is a problem that the strength is lower than 33.
It should be noted that the positions and the numbers of the welds described above are given as examples, and may be appropriately changed depending on the positions and the numbers of the gates and the openings.
[0007]
As a countermeasure against the decrease in the strength of the weld portion, a reinforcing member is embedded in the weld portion to improve the strength of the weld portion. For example, in a thrust washer disclosed in Japanese Utility Model Laid-Open No. 6-62222, a reinforcing member is buried in a circumferential direction in a weld portion generated in a thrust washer formed by injecting a molten resin material into an annular cavity. The structure is disclosed.
[0008]
Further, the vibration isolator disclosed in Japanese Patent Application Laid-Open No. H11-115800 discloses a method for simultaneously molding an enclosing portion surrounding a rubber elastic body and an extension extending from the enclosing portion. There is disclosed a structure in which a high-strength reinforcing material that circulates around is embedded.
Further, Japanese Patent Application Laid-Open No. 2001-341670 discloses a front end panel which is a molded body made of glass fiber reinforced resin obtained by injection molding, and in which a metal plate is arranged in a portion including a weld portion of the molded body. Have been.
[0009]
(Patent Document 1)
Japanese Utility Model Application Laid-Open No. 6-62222 (claims for registering utility models, FIG. 1)
(Patent Document 2)
JP-A-11-115800 (Claims, FIG. 1)
(Patent Document 3)
JP 2001-341670A (Claims)
[0010]
[Problems to be solved by the invention]
As described above, compression-molded products are sometimes used for parts that require high strength. However, in the case of compression molding, secondary processing such as cutting is required after molding, and the number of manufacturing steps increases. Cost increase.
In addition, in the case of injection molding, the weld portion where the resin material injected into the mold associates with each other, the reinforcing fibers are oriented, and only the matrix resin is laminated, and the strength is reduced partially (weld portion). There's a problem. Therefore, in this injection-molded product, it is necessary to design the generated welded portion so as not to be located at a location where stress is concentrated in an environment where the component is actually used, and the degree of freedom in design and molding is lost.
[0011]
Furthermore, when the back door of an automobile is made of resin by injection molding, a glass fiber reinforced resin material may be used for the inner panel, but the inner panel needs to maintain the rigidity and strength of the entire back door. Since the strength against a collision from behind is also required, it is necessary to improve the strength reduction at the weld portion.
[0012]
Further, the thrust washer disclosed in Japanese Utility Model Laid-Open No. 6-62222, the vibration isolator disclosed in Japanese Patent Application Laid-Open No. 11-115800, and the front end panel described in Japanese Patent Application Laid-Open No. 2001-341670 are all provided with reinforcing members at welds generated during injection molding. Are buried to reinforce the weld portion, but the reinforcing members are all made of metal, and no consideration is given to the problem regarding the bonding strength between the metal reinforcing member and the injected resin material. In addition, there is a possibility that a new weld portion may be generated around the reinforcing member, and no countermeasure is taken.
[0013]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a weld part reinforced resin part that reinforces a weld part generated at the time of injection molding, and firmly couples the reinforcing member with an injected resin material, and manufacturing the same. The aim is to provide a method.
[0014]
[Means for Solving the Problems]
According to the present invention, as a means for solving the above-mentioned problem, the invention according to claim 1 includes a resin part formed by injection molding, in which a fiber is contained in a weld portion where the injected resin material associates. It is characterized by having a resin piece inside.
With this configuration, the resin portion containing the fiber is embedded in the weld portion, so that the strength of the weld portion can be improved.
[0015]
According to a second aspect of the present invention, in the first aspect of the invention, the matrix resin of the injected resin material and the matrix resin of the resin piece are formed of the same type. It is.
With this configuration, the resin material to be injected and the resin piece that reinforces the weld portion can be melted into each other and firmly bonded.
[0016]
The invention described in claim 3 is the invention according to claim 1 or 2, wherein the resin piece is substantially sheet-shaped.
With this configuration, the resin piece can be easily cut into a desired shape, and it is possible to follow a complicated product shape.
[0017]
The invention described in claim 4 is the invention according to any one of claims 1 to 3, wherein the injected resin material is a glass fiber reinforced polypropylene resin, and the resin piece is a glass mat reinforced polypropylene resin. It is characterized by the following.
With this configuration, since both matrix resins are of the same type of polypropylene resin, and the reinforcing fibers are of the same type of glass fiber, the weld portion and the other portions have substantially the same strength. it can.
[0018]
According to a fifth aspect of the present invention, in the method of manufacturing a resin component formed by injection molding, after a resin piece containing fibers is arranged at a location where the resin material meets inside the mold, the resin material is injected. It is characterized by doing.
With such a configuration, the weld portion can be reinforced with the resin pieces at the same time as the injection molding, so that the molding is facilitated without increasing the number of steps such as secondary processing.
[0019]
According to a sixth aspect of the present invention, in the method for manufacturing a resin component formed by injection molding, a resin in which fibers are contained in the weld portion before the weld portion where the injected resin material associates is cured. It is characterized in that the pieces are crimped by a movable nest.
With this configuration, the resin piece containing the fiber and the resin material to be injected are melted and bonded to each other in a softened state, so that a weld portion generated around the resin piece is prevented and the two are firmly bonded. can do. Further, by using the movable nest, when arranging the resin piece in the mold, the positional accuracy such as the insertion depth is improved.
[0020]
The invention described in claim 7 is characterized in that, in the invention described in claim 5 or 6, after the resin piece is softened by heating, it is arranged at a predetermined position inside the mold or at any of the movable inserts. To do.
With this configuration, the injected resin material and the resin piece are melted into each other in a softened state, so that the two can be firmly bonded.
[0021]
The invention described in claim 8 is the invention according to any one of claims 5 to 7, wherein the resin piece is softened by heating, and then a pin is inserted into a predetermined position inside the mold or any of the movable inserts. And is fixed.
With this configuration, when the resin material is injected into the mold, the resin piece is prevented from being displaced by the flow of the resin material, and when the resin piece is fixed to the mold or the movable nest. Positioning becomes easy.
[0022]
According to a ninth aspect of the present invention, in the invention according to any one of the fifth to eighth aspects, the matrix resin of the injected resin material and the matrix resin of the resin piece are formed of the same type. It is characterized by the following.
With this configuration, the resin material to be injected and the resin piece are melted and melted together in a softened state, and are firmly bonded. Therefore, an adhesive or the like for bonding the resin material and the resin piece at the time of molding is not required, and the molding process is not required. Can be simplified.
[0023]
The invention described in claim 10 is the invention according to any one of claims 5 to 9, wherein the resin piece is substantially sheet-shaped.
With this configuration, since the handling of the resin piece is simple, the resin piece can be easily fixed to a predetermined position in the mold or the tip of the movable nest.
[0024]
In the invention described in claim 11, in the invention described in any one of claims 5 to 10, the injected resin material is a glass fiber reinforced polypropylene resin, and the resin piece is a glass mat reinforced polypropylene resin. It is characterized by the following.
With this configuration, the weld portion is reinforced by the resin pieces, and the bonding strength between the resin material and the resin pieces is increased.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a weld portion reinforced resin component according to an embodiment of the present invention and a method for manufacturing the same will be described in detail with reference to FIGS.
The weld part reinforced resin part according to the embodiment of the present invention is a resin part that is injection-molded, and is used for an inner panel that requires high strength, for example, to maintain the rigidity and strength of the entire back door of an automobile. Have been.
FIG. 1 is a view showing a first method of manufacturing an inner panel 1 which is a welded part-reinforced resin part according to an embodiment of the present invention. In particular, FIG. As can be seen from the cross-sectional view of FIG. 6, the inner panel 1 indicated by spots has glass mat reinforced polypropylene at weld portions (weld portions 32 and 32 ′ shown in FIG. 6) where glass fiber reinforced polypropylene resin of the resin material to be injected is associated. It is formed by injecting a substantially sheet-shaped resin piece 2 made of resin and injecting a glass fiber reinforced polypropylene resin.
[0026]
Thus, according to the weld part reinforced resin part according to the embodiment of the present invention, at the time of injection molding, the glass fiber reinforced polypropylene resin having glass fibers in the weld part where the glass fiber reinforced polypropylene resin to be injected is associated with The strength of the weld portion can be improved by incorporating a substantially sheet-shaped resin piece made of In addition, since the polypropylene resin, which is the matrix resin of the glass fiber reinforced polypropylene resin to be injected, and the polypropylene resin, which is the matrix resin of the glass mat reinforced polypropylene resin of the resin piece inside the weld portion, are made of the same material, the bonding strength between each other is increased. Can be improved.
[0027]
Next, a first method for manufacturing a weld part reinforced resin component according to an embodiment of the present invention will be described in the following (1) to (4) with reference to FIGS.
(1) First, as shown in FIG. 1A, a sheet material made of a glass mat reinforced polypropylene resin is cut into a predetermined shape to form a substantially sheet-shaped resin piece 2.
{Circle around (2)} As shown in FIG. 1 (b), this resin piece 2 (black portion) is inserted between the heating furnaces 3 arranged vertically, and heated from both sides by infrared heating for a predetermined time. Then, the resin piece 2 is softened. Here, the heating temperature is set to a predetermined value within 210 ° C. to 220 ° C., and the heating time is set to a predetermined time within 3 minutes to 10 minutes.
(3) Next, as shown in FIG. 1 (c) and FIG. 2, while the resin piece 2 is in a softened state, a plurality of fixing pins 5 are applied to the inner wall surface 40 'of one mold 4'. And fix it. The plurality of fixing pins 5 protrude from the inner wall surface 40 'of the mold 4' and are formed near a location where the glass fiber reinforced polypropylene resin to be injected meets.
[0028]
{Circle around (4)} Then, the molds 4 and 4 ′ are closed, and the glass fiber reinforced polypropylene resin is injected from the injection molding machine 7 through the gate section 6, and the inner panel 1 (weld spot reinforced resin part) Part). Here, the temperature of the glass fiber reinforced polypropylene resin at the time of injection is set to a predetermined value within 200 ° C. to 250 ° C., and the temperature of the molds 4 and 4 ′ is set to a predetermined value within 40 ° C. to 60 ° C. Is set.
[0029]
According to the first manufacturing method described above, a resin piece made of a glass mat reinforced polypropylene resin is fixed via a fixing pin in advance at a position in a mold corresponding to a portion where a weld portion occurs in an injection molded product. Later, since the glass fiber reinforced polypropylene resin is injected from the gate portion, a resin piece is included in the weld portion to reinforce the weld portion, and the reinforcement of the weld portion can be performed at the same time as the injection molding. No process is required. In addition, the resin piece made of glass mat reinforced polypropylene resin is fixed in the mold in a softened state, and the glass fiber reinforced polypropylene resin to be injected and the glass mat reinforced polypropylene resin of the resin piece melt into each other in a softened state. The two can be firmly bonded.
[0030]
Next, a second method of manufacturing a weld part reinforced resin component according to an embodiment of the present invention will be described in the following (1) to (4) with reference to FIGS. In the description of the second manufacturing method, the same components as those constituting the weld portion reinforced resin component according to the embodiment of the present invention and members used in the first manufacturing method and corresponding components have the same reference numerals. This will be described using.
(1) First, similarly to the first manufacturing method, as shown in FIG. 3A, a sheet material made of a glass mat reinforced polypropylene resin is cut into a predetermined shape to form a substantially sheet-shaped resin piece 2. Form.
{Circle around (2)} Similarly to the first manufacturing method, as shown in FIG. 3B, this resin piece 2 (black painted portion) is inserted between heating furnaces 3 arranged vertically. Then, the resin pieces 2 are softened by heating from both sides by infrared heating for a predetermined time. Here, the heating temperature is set to a predetermined value within 210 ° C. to 220 ° C., and the heating time is set to a predetermined time within 3 minutes to 10 minutes.
(3) Next, as shown in FIG. 3 (c) and FIG. 4, in a state where the resin piece 2 is softened, a plurality of fixing pins 9 are attached to the tip of the movable nest 8 provided on one mold 4 '. Fixed through. The plurality of fixing pins 9 are formed so as to protrude from the distal end of the movable nest 8.
The position where the movable nest 8 is disposed in one mold 4 ′ is such that the resin piece 2 fixed to the tip of the nest 8 meets the glass fiber reinforced polypropylene resin in the other mold 4. In such a case, it is disposed so as to be internal to a portion where a weld portion is generated.
[0031]
{Circle around (4)} Then, both molds 4 and 4 ′ are closed, and a glass fiber reinforced polypropylene resin is injected from the injection molding machine 7 through the gate section 6, and the glass fiber reinforced polypropylene resin is At the same time as filling the inside of 4 ', the movable nest 8 provided on one mold 4' is actuated to the other mold 4 side, and the resin piece 2 fixed to the tip of the movable nest 8 is injected into the glass. The inner panel 1 (spotted portion) is formed by pressing the fiber reinforced polypropylene resin against the weld portion before being cured. Here, the temperature of the glass fiber reinforced polypropylene resin at the time of injection is set to a predetermined value within 200 ° C. to 250 ° C., and the temperature of the molds 4 and 4 ′ is set to a predetermined value within 40 ° C. to 60 ° C. Is set.
[0032]
According to the second manufacturing method described above, the movable nest is operated to press the resin piece onto the weld portion before the glass fiber reinforced polypropylene resin injected into the mold is cured. Is strengthened, and the injected glass fiber reinforced polypropylene resin and the glass mat reinforced polypropylene resin of the resin piece melt into each other in a softened state, so that a weld portion where the glass fiber reinforced polypropylene resin associates around the resin piece is formed. There is no new generation, and both can be firmly bonded.
[0033]
Here, as shown in FIG. 5, a tensile breaking load test (test method: JIS K 7162) was performed on each of the test pieces 20 to 22 formed in the shape of a 1A multipurpose test piece from the following various test materials. Was. Various test materials and the test results are shown below.
1. Test material test piece 20: A resin material made of glass fiber reinforced polypropylene resin (Funkster LR23C / Chisso (30% by weight of glass)) is injection molded and has no weld portion 23.
Test piece 21: Injection molded from the above-mentioned resin material, and having a weld portion 23 substantially at the center.
Test piece 22: A resin piece made of the above resin material and injection-molded, and a resin piece 24 made of a glass mat reinforced polypropylene resin is provided in a substantially central weld part 23 to reinforce the weld part 23.
2. Test result Test piece 20: tensile strength 120 MPa
Test piece 21: Tensile strength 30 MPa
Test piece 22: Tensile strength 100 MPa
[0034]
As can be seen from the above test results, the test piece 20 of the glass fiber reinforced polypropylene resin without the weld part 23 and the test piece 22 in which the resin piece 24 is embedded in the weld part 23 and the weld part 23 is reinforced are almost equivalent. The strength can be confirmed.
Therefore, in the weld part reinforced resin component according to the embodiment of the present invention, the weld part is made to be internal to the resin piece made of glass mat reinforced polyprolene resin and reinforced, so that the reinforced weld part is substantially equal to other parts. It is possible to form with the strength of.
[0035]
Note that the resin material to be injected is glass fiber reinforced polypropylene resin, and the form in which the resin pieces existing in the weld portion are formed of glass mat reinforced polypropylene resin has been described.However, both matrix resins are made of another thermoplastic resin, for example, It may be made of polyethylene resin, nylon resin, or the like.
[0036]
【The invention's effect】
As described above, according to the invention of the weld portion reinforced resin component according to claims 1 to 4, the weld portion where the glass fiber reinforced polypropylene resin as the resin material to be injected is associated with the glass mat reinforced polypropylene resin. Since the weld portion is reinforced by including the substantially sheet-shaped resin piece therein, the reinforced weld portion and other portions can be formed with substantially the same strength.
[0037]
According to the invention of the method for manufacturing a weld part reinforced resin part according to claim 5, by fixing a resin piece to a portion where a resin material meets in a mold to be injection-molded, the resin material is injected, Since the weld portion can be reinforced at the same time as the injection molding, molding is facilitated without increasing the number of steps such as secondary processing.
[0038]
According to the invention of the method for manufacturing a weld part reinforced resin component according to claim 6, the resin piece is crimped to the weld part by the movable insert when the weld part where the injected resin material associates is not cured. Therefore, the injected resin material and the resin piece are firmly bonded to each other, and the occurrence of a new weld around the resin piece is prevented.
[0039]
According to the invention of the method for manufacturing a weld part reinforced resin part according to claims 7 and 8, since the resin piece is fixed in a mold or a movable nest via a pin in a softened state, the resin piece is injected. The resin piece and the resin material can be firmly bonded at a predetermined position without being displaced by the flow of the resin material to be performed.
[0040]
According to the invention of the method for manufacturing a weld part reinforced resin part according to claims 9 to 11, the resin material to be injected is a glass fiber reinforced polypropylene resin and the resin piece is a glass mat reinforced polypropylene resin. Thereby, the weld portion can be reinforced and the bonding strength between the resin piece and the resin material can be increased.
[Brief description of the drawings]
FIG. 1 is a view showing a first method of manufacturing a weld part reinforced resin part according to an embodiment of the present invention, wherein (a) is a perspective view showing a resin piece, and (b) is a resin piece. (C) is a diagram showing a cross-sectional view during injection molding.
FIG. 2 is an enlarged view showing a portion A in FIG. 1;
FIGS. 3A and 3B are views showing a second method of manufacturing a weld part reinforced resin part according to the embodiment of the present invention, wherein FIG. 3A is a perspective view showing a resin piece, and FIG. (C) is a diagram showing a cross-sectional view during injection molding.
FIG. 4 is an enlarged view showing a portion B in FIG. 3;
FIG. 5 is a view showing a test piece injection-molded with each test material.
FIG. 6 is a plan view showing an inner panel formed by conventional injection molding.
FIG. 7 is an enlarged view showing a weld part and its periphery in FIG. 6;
[Explanation of symbols]
1. Inner panel (weld reinforced resin parts)
2 Resin pieces 4, 4 'Mold 5, 9 Fixing pin 6 Gate 7 Injection molding machine 8 Movable nest

Claims (11)

A weld part reinforced resin part characterized in that a resin part containing fibers is inherent in a weld part where an injected resin material associates with a resin part formed by injection molding. The weld part reinforced resin part according to claim 1, wherein the matrix resin of the injected resin material and the matrix resin of the resin piece are formed of the same type. The weld part reinforced resin part according to claim 1, wherein the resin piece has a substantially sheet shape. The weld part reinforced resin part according to any one of claims 1 to 3, wherein the injected resin material is a glass fiber reinforced polypropylene resin, and the resin piece is a glass mat reinforced polypropylene resin. A method for manufacturing a resin component formed by injection molding, wherein a resin piece containing fibers is placed at a location where the resin material meets inside a mold, and then the resin material is injected, wherein the resin material is injected. Manufacturing method of resin parts. In a method of manufacturing a resin component formed by injection molding, in a state before a weld portion where an injected resin material associates is cured, a resin piece containing fibers is press-bonded to the weld portion by a movable nest. Manufacturing method of weld part reinforced resin parts. The method according to claim 5 or 6, wherein the resin piece is softened by heating and then placed at a predetermined position inside the mold or at a movable nest. The weld part reinforced resin according to any one of claims 5 to 7, wherein the resin piece is softened by heating and then fixed to a predetermined position inside the mold or any of the movable nests via a pin. The method of manufacturing the part. The method of manufacturing a weld part reinforced resin part according to any one of claims 5 to 8, wherein the matrix resin of the injected resin material and the matrix resin of the resin piece are formed of the same type. . The method according to any one of claims 5 to 9, wherein the resin piece is substantially sheet-shaped. The method according to claim 5, wherein the resin material to be injected is a glass fiber reinforced polypropylene resin, and the resin piece is a glass mat reinforced polypropylene resin. .

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