JP2530583B2 - Manufacturing method of car mudguard - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a mudguard for an automobile, and more particularly to a method for manufacturing a mudguard by so-called sandwich molding.

[0002]

2. Description of the Related Art For example, as shown in FIG.
This mudguard 100 for an automobile includes a plate-shaped mudguard 103 that constitutes a mudguard body, and a first attachment portion 101 that extends over the entire upper part of the mudguard 103 for attaching to a tire house of an automobile. And a second mounting portion 102 that is also partially stretched laterally above the mudguard portion 103. In this type of automobile mudguard, the mudguard 103 is made of a soft resin because of its large vibration and requiring flexibility.
The mounting portions 101 and 102 are made of a hard resin because they are required to have rigidity because they serve as a seating surface for mounting on a vehicle.
Further, since the surfaces of the mounting portions 101 and 102 are designed surfaces, they are covered with the soft resin forming the mudguard portion 103. Reference numeral 105 is a mounting hole of the mounting portion.

In order to obtain a mudguard for an automobile which integrally has such an entire surface and a mudguard portion made of a soft resin and a mounting portion having a core portion of a hard resin, so-called sandwich molding has been conventionally performed. .

Sandwich molding is to obtain a molded product in which a hard resin is incorporated in a soft resin by, for example, a two-layer injection device having a double needle structure. A known two-layer injection device, for example, a sandwich injection molding machine manufactured by Toshiba Machine Co., Ltd., includes an injection unit (barrel) for supplying a hard resin material and an injection unit (barrel) for supplying a soft resin material.
And an inner needle valve for hard resin and an outer needle valve for soft resin.

With this apparatus, the soft resin material forming the surface of the product is first injected into the mold, and then the hard resin material forming the core layer is injected. The injected hard resin material flows through the mold while flowing away the previously injected soft resin material to form a core layer inside the product.

However, in this sandwich molding, it is difficult to control the flow of the hard resin on the inner side, and the hard resin material often flows into a portion which should be composed of the soft resin, or the hard resin material flows into a predetermined portion. It may be out of reach. This was particularly remarkable when controlling the flow of the hard resin material for a plurality of independent mounting portions such as the first mounting portion 101 and the second mounting portion 102 as shown in the figure.

That is, as is well understood from the cross-sectional views of FIGS. 11 and 12, the hard resin materials H1 and H2 flow into a portion that should not flow in originally, or a hard resin material flows into a portion that should flow in for a mounting portion. There is a problem that the resin material H3 does not flow in and its mounting strength is low.

Among them, as shown in FIGS. 12 and 13, when the hard resin material H2 flows into the mudguard portion 103 which is required to have flexibility, the mudguard portion 103 and the mounting portion 1
The rigidity of the boundary part of No. 02 increases and the flexibility of the boundary part deteriorates, and problems such as crack C and whitening occur as it is used.

Therefore, as disclosed in Japanese Unexamined Patent Publication No. 3-86509, in the cavity having the shape of the molded product, the hard portion is formed in the vicinity of the branch of the hard portion forming portion and the soft portion forming portion from the main body forming portion. A molding die provided with a flow resistance part for suppressing the inflow of the skin layer material in the partial forming part is used to inject the skin layer material into the cavity via the main body forming part, and then the core layer in the skin layer material. Methods of injecting materials have been proposed.

However, even with this method, the flow of the hard resin in the product cannot be completely controlled, and the portion where the flow resistance portion is provided in the molding die appears as a thin portion on the product, and May reduce strength. Further, it is extremely difficult to control the flow to the plurality of mounting parts.

[0011]

SUMMARY OF THE INVENTION Therefore, the present invention
It was proposed in order to solve such a problem, and surely injects the hard resin material into the mounting portion that requires the hard resin, and to the mudguard portion where the hard resin is unnecessary. An object of the present invention is to provide a novel method for manufacturing a mudguard for an automobile, which suppresses the inflow of the hard resin material. The present invention also seeks to provide an extremely effective manufacturing method for a mudguard having a plurality of mounting portions.

[0012]

That is, the present invention provides:
An entire surface and a mudguard portion made of a soft resin, a first mounting portion having a hard resin core portion extending over the entire upper portion of the mudguard portion, and the mudguard portion upper side When obtaining a mudguard for an automobile integrally with a second mounting portion having a hard resin core portion partially stretched in one direction, the first mounting portion and the second mounting portion of the mudguard-shaped mold cavity are obtained. A first injection port and a second injection port are provided in contact with the first mounting portion cavity portion and the second mounting portion cavity portion, respectively.
This is a method of molding using a two-layer injection device in which a hard resin material that constitutes the core portion inside and a soft resin material that flows in the outside thereof flow.

The first inlet and the second inlet are provided via a first runner portion and a second runner portion branched from a single resin material flow path, and the second inlet is It is configured to be openable / closable by a retractable blocking member provided in the middle of the second runner portion, and first, the blocking member provided in the second runner portion is advanced to close the second inlet, and A soft resin material in an amount obtained by subtracting an amount corresponding to the core part and the second mounting part of the first mounting part from the first pouring port is injected into the cavity, and then, with the second pouring port closed, After the injection of the soft resin material is started or after the injection is completed, the hard resin material forming the core portion of the first mounting portion is injected into the cavity from the first injection port, and then after the injection of the hard resin material is started or After infusion, Note Manufacture of a mudguard for an automobile, characterized in that the blocking member provided in the second runner portion is retracted to open the second injection port, and the soft resin material and the hard resin material forming the second mounting portion are injected. According to the method.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic view showing a cavity and a runner portion inside a molding die showing a first step in a method for manufacturing a mudguard for an automobile of the present invention, FIG. 2 is a front view of the cavity of FIG. 1, and FIG. Schematic diagram showing the steps of
4 is a front view of the cavity of FIG. 3, FIG. 5 is a schematic view showing the same third step, and FIG. 6 is a front view of the cavity of FIG.
7 is a sectional view of the cavity showing the flow of the resin material in the third step, FIG. 8 is a sectional view of the cavity showing the confluent state of the resin material in the third step, and FIG. 9 is the retention portion of the second runner portion. 3 is a schematic diagram showing the flow of the resin material in FIG.

The present invention, as described above and shown in FIG. 10, includes an entire surface made of a soft resin and a mudguard portion, and a hard resin core extending over the entire upper portion of the mudguard portion. The present invention relates to a method for obtaining a mudguard for an automobile, which integrally has a first attachment portion having a portion and a second attachment portion having a hard resin core portion partially stretched laterally above the mudguard portion. .

FIG. 1 is a schematic view showing a cavity and a runner portion inside a molding die showing an example of a molding die for carrying out the method for manufacturing a mudguard for an automobile of the present invention. In the figure, reference numeral 10 represents the entire mudguard-shaped mold cavity, 11 is a first mounting portion cavity portion that constitutes a first mounting portion of the mudguard, 12 is a second mounting portion cavity portion that also constitutes a second mounting portion, Reference numeral 13 denotes a mudguard cavity portion which constitutes the mudguard.

Reference numeral 21 is a first injection port provided in contact with the first mounting cavity portion 11, 22 is a second injection port similarly provided in contact with the second mounting cavity portion 12, and 25 is a molding. A resin flow path of a resin material for use herein represents a sprue, 26 is a first runner portion branching from the resin flow path 25 to reach the first inlet 21, and 27 is a branch line from the resin flow path 25. The second runner portion reaching the second inlet 22 is a branch portion of the first runner 26 and the second runner 27.

Further, reference numeral 30 is a movable blocking member provided in the middle of the second runner portion 27, and 35 is a stay for the resin material provided between the blocking member 30 and the second inlet 22. It is a department.

In the present invention, the well-known two-layer injection device as described above is used, and the hard resin material H constituting the core portion inside the single resin flow path (sprue portion) 25 and the soft resin material outside thereof are used. The resin material S is molded so as to flow in.

As will be described below, the present invention comprises a first step of injecting the soft resin material S from the first injection port 21 and a second step of injecting the hard resin material H from the first injection port 21 as well. The third step is to inject the soft resin material S and the hard resin material H from the second injection port 22.

First, the first step will be described with reference to FIG.
Further, as shown in FIG. 2, the blocking member 30 provided in the second runner portion 27 is advanced to close the second injection port 22.
The operation of the blocking member 30 can be performed by a known hydraulic cylinder device or the like. Then, a predetermined amount of the soft resin material S is injected from the resin flow path 25 into the cavity 10 via the first injection port 21.

The amount of the soft resin material S injected at this time is the amount obtained by subtracting the amount corresponding to the core portion and the second attachment portion of the first attachment portion from the total amount of resin filled in the cavity. Therefore, as shown in the drawing, an unfilled cavity portion is created in the cavity tip portion 10A farther from the first injection port 21. Since the blocking member 30 of the second runner portion 27 is provided on the way, the soft resin material S
Flows into the second runner portion 27A from the branch portion 29 of the first runner 26 and the second runner 27 to the blocking member 30.

Next, in the second step, as shown in FIGS. 3 and 4, the second runner portion 2 is formed as in the first step.
7 to move the blocking member 30 provided in
The hard resin material H is injected into the cavity 10 from the first injection port 21 in the closed state. The injection of the hard resin material H can be performed after the injection of the soft resin material is started or after the injection of the soft resin material is completed, depending on the function of the two-layer injection device. The injection amount of the hard resin material in the second step is an amount that constitutes the core portion of the first attachment portion.

Next, in the third step, as shown in FIGS. 5 and 6, the second inlet 22 is opened and the second inlet 22 is opened.
From the second mounting portion cavity portion 12 into the soft resin material S
And the hard resin material H is injected. That is, the blocking member 3 provided in the second runner portion 27 after the start or the end of the injection of the hard resin material in the second step.
The second inlet 22 is opened by retracting from 0.

Then, the soft resin material S and the hard resin material H forming the second mounting portion are transferred from the second runner portion 27 through the second injection port 22 to the second mounting portion cavity portion 12
Is injected into. At this time, since the soft resin material S injected in the first step fills the second runner portion 27A from the branch portion 29 of the second runner portion 27 to the blocking member 30, the soft resin material S should be considered. Then, the hard resin material H is injected. That is, this second runner portion 27
If the soft resin material S filling A is the amount of the soft resin material S forming the second mounting portion, only the hard resin material H needs to be injected. If the amount of the soft resin material S is small, the shortage is replenished together with the hard resin material H.

Further, as in the illustrated embodiment, between the blocking member 30 of the second runner portion 27 and the second injection port 22, if necessary, a part of the runner portion is swelled, The retention portion 35 may be formed. This retention section 35
As a result, as shown in FIG. 9, a part of the soft resin material S stays in the stay portion 35, and the amount of the soft resin material S flowing into the cavity can be adjusted.

The soft resin material S and the hard resin material H which have flowed into the second mounting portion cavity portion 12 flow through the cavity portion 12 as shown in FIG. 7 and FIG. By the process, it merges with the resin material that has flowed into the cavity 10 and is fused together.

In the third step, the timing for retracting the blocking member 30 to open the second inlet 22, the cross-sectional area and length of the second runner portion 27, and the size of the retention portion 35 are set. By adjusting, the amounts and ratios of the soft resin material S and the hard resin material H flowing into the cavity from the second injection port 22 can be appropriately changed, and these can be appropriately adjusted according to the requirements of the molded product. It goes without saying that it is a thing.

The first to third injection steps can be continuously injected by the above-mentioned two-layer injection apparatus.

[0030]

As shown and described above, according to the method for manufacturing a mudguard for an automobile of the present invention, the hard resin material is surely injected into the mounting portion requiring the hard resin,
In addition, since the flow of the hard resin material can be suppressed and the fluidity can be reliably controlled in the mudguard where unnecessary hard resin is needed, for example, in the mudguard, where the core layer is not needed, It is possible to prevent the resin material from flowing in. Therefore, it is possible to obtain a product in which the characteristics of the resin are fully utilized without causing cracking or whitening of the mudguard portion. In particular, the present invention is extremely effective and useful in a product having a plurality of mounting portions that require a hard resin core layer.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a cavity and a runner portion inside a molding die showing a first step in a method for manufacturing a mudguard for an automobile of the present invention.

2 is a front view of the cavity of FIG. 1. FIG.

FIG. 3 is a schematic diagram showing a second step of the same.

FIG. 4 is a front view of the cavity of FIG.

FIG. 5 is a schematic diagram showing a third step of the same.

FIG. 6 is a front view of the cavity of FIG.

FIG. 7 is a cross-sectional view of a cavity showing a flow of resin material in a third step.

FIG. 8 is a cross-sectional view of a cavity showing a confluent state of resin materials in a third step.

FIG. 9 is a schematic diagram showing a flow of a resin material in a retention portion of a second runner portion. It is an injection pattern figure of soft resin and hard resin.

FIG. 10 is a perspective view showing an example of an automobile mudguard.

11 is a cross-sectional view taken along line XX of FIG.

12 is a cross-sectional view taken along the line YY of FIG.

FIG. 13 is an enlarged cross-sectional view of a Z portion of FIG.

[Explanation of symbols]

 10 Molded Product Cavity 11 First Attachment Cavity Part 12 Second Attachment Cavity Part 13 Mudguard Cavity Part 21 First Injection Port 22 Second Injection Port 25 Resin Flow Path (Sprue) 26 First Runner Part 27 Second Runner part 30 Blocking member 35 Stagnation part S Soft resin (material) H Hard resin (material)

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // B29L 31:30 B29L 31:30

Claims (2)

(57) [Claims] 1. A first mounting portion having an entire surface made of a soft resin and a mudguard portion, and a hard resin core portion extending over an entire upper portion of the mudguard portion. , The mudguard
It has a hard resin core part that is partially stretched on the upper side
When obtaining a mudguard for an automobile that integrally has a second mounting portion, a first mounting portion cavity portion and a second mounting portion cavity that form the first mounting portion and the second mounting portion of the mudguard-shaped mold cavity. A first injection port and a second injection port are respectively provided in contact with the portions, and a two-layer injection device in which a hard resin material forming a core portion inside and a soft resin material in the outside from the injection port are injected using the two-layer injection device The first inlet and the second inlet are provided via a first runner portion and a second runner portion branched from a single resin material flow path, and the second inlet Is configured to be openable / closable by a retractable blocking member provided in the middle of the second runner portion. First, the blocking member provided in the second runner portion is moved forward to make a second injection. Close the mouth, inject into the cavity a soft resin material in an amount obtained by subtracting the amount corresponding to the core portion and the second attachment portion of the first attachment portion from the first inlet, then, the second inlet In the closed state, after injecting or after injecting the soft resin material, inject the hard resin material forming the core portion of the first mounting portion into the cavity from the first injection port, then, the hard resin material After the start of injection or after the end of injection, the blocking member provided in the second runner part is retracted to open the second injection port, and the soft resin material and the hard resin material forming the second mounting part are injected. A method for manufacturing a mudguard for an automobile, characterized by: 2. The method for manufacturing an automobile mudguard according to claim 1, further comprising a resin material retention portion between the blocking member of the second runner portion and the second injection port.