JPH10129359A - Roof rack for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts and to prevent the occurrence f shrinkage breakage due to a difference in a percentage of contraction between a core and covering resin, in a a roof rack for a vehicle the outside of which is covered with synthetic resin. SOLUTION: A roof rack 10 for a vehicle comprises a rack body 11 extending longitudinally of a car body on the upper side of a vehicle roof; and mounting parts 12, 13, and 14 to a car body, and is formed such that the outside is covered with synthetic resin. In the roof rack for a vehicle, the core made of a metal of the rack body having a mounting part to the car body being integrally formed is securely inserted in a molding die. By injecting polypropylene resin, containing 5-40wt.% glass-reinforced fibers of long fibers with a length of 6-13mm, in a molding space in which the core made of a metal is held, and filling the the molding space with the polypropylene resin, the rack body and the mounting parts to the car body are integrally molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle roof rack whose outside is covered with a synthetic resin.

[0002]

2. Description of the Related Art Conventionally, as a roof rack provided on the upper side of a vehicle roof, for example, as shown in Japanese Utility Model Laid-Open No. 6-59155 and Japanese Utility Model Laid-Open No. 6-67194, a rack body extending in the vehicle longitudinal direction is made of aluminum. And the like, and a mounting portion (mounting leg) to a vehicle body is formed by die-casting such as aluminum or zinc, and both are assembled and integrated.

On the other hand, it has been considered that only the mounting legs and the core material of the rack body are made of metal, and the outside thereof is covered with a synthetic resin. By adopting such a configuration, it is possible to reduce the weight while securing the strength and rigidity required for the roof rack, and to improve the appearance. Although it is not particularly conscious that the outside of the entire roof rack is covered with a synthetic resin, for example, in Japanese Utility Model Laid-Open No. 6-51003, at least the outside of the mounting leg is covered with a separate resin cover. A structure adapted to be used is disclosed.

[0004]

In each of the above-mentioned roof racks according to the prior art, the roof rack body and the mounting legs (usually at least two) are separately manufactured, and then the two are assembled and integrated. However, in recent years, from the viewpoint of simplifying a vehicle assembly process and simplifying component management, it is required to minimize the number of components in such a roof rack.

[0005] When manufacturing a part or member by covering a predetermined surface region or the whole of a core material with a synthetic resin, it is necessary to insert and fix a core material into a mold and then inject a molten resin into the mold, for example. Thus, a so-called insert molding method in which a molded body whose predetermined surface area or the whole is covered with a synthetic resin is integrally molded, is generally well known. According to this insert molding method, since the coating resin and the core material are integrally molded, an increase in the number of parts can be suppressed, the labor for assembling the two is unnecessary, and the adhesion between the two can be improved.

However, in such an insert molding method, when the core material is made of a metal such as iron or steel, for example, the shrinkage ratio between the core material and the coating resin is too different, so that the molten resin in the insert molding process is not used. During coagulation,
There was a drawback that shrinkage cracks easily occurred in the coating resin.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and aims to reduce the number of parts in a vehicle roof rack whose outside is covered with a synthetic resin and to reduce the shrinkage of a core material and a coating resin. The purpose is to prevent shrinkage cracking caused by the difference.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides
A vehicle roof rack including a rack body extending in the vehicle longitudinal direction above a vehicle roof and a mounting portion to the vehicle body, the outside of which is covered with a synthetic resin, wherein the mounting portion to the vehicle body is integrally formed. The metal core material of the rack body is insert-fixed in a molding die, and a glass reinforced fiber having a long fiber length of 6 to 13 mm is filled in a molding space holding the metal core material in an amount of 5 to 40% by weight. By injecting and filling the contained polypropylene resin, the rack body and the mounting portion to the vehicle body are integrally formed.

[0009] Here, the length of the glass reinforcing fiber is 6-13.
When it is contained in the polypropylene resin, if it is contained in the polypropylene resin, if it is less than 6 mm, entanglement of the glass reinforcing fiber is difficult to occur and the reinforcement is not sufficient, while if it exceeds 13 mm, the glass reinforced fiber is too entangled and uniform dispersion occurs. This is because it cannot be expected, and unevenness in strength occurs and also adversely affects the moldability. Further, the content of the glass reinforcing fiber is 5 to 40% by weight.
The reason is that if it is less than 5% by weight, it is difficult to effectively prevent shrinkage cracking at the time of solidification because the material resin (polypropylene resin) cannot be sufficiently reinforced because it is too small.
If the content is more than 40% by weight, the glass reinforcing fiber is too much and is exposed on the surface of the molded article to impair its surface properties, and also adversely affects the moldability. The content of the glass reinforcing fiber is preferably about 10% by weight in consideration of moldability, production cost, and the like, in addition to the reinforcing effect required for effectively preventing shrinkage cracking during solidification. .

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is an overall perspective view of an automobile 1 equipped with a roof rack 10 according to an embodiment of the present invention. As shown in this figure, the roof rack 10 is provided in a pair on the right and left above the vehicle body roof 2. For example, if the right rack is described as an example, as shown in FIGS. It has a rack body 11 extending in the front-rear direction and a plurality of legs 12, 13, 14 for attachment to the vehicle body roof 2, and the outside is covered with a synthetic resin skin.

In this embodiment, as shown in FIG. 4, the rack body 11 has a core 16 made of, for example, a steel pipe therein, and the mounting legs 12, 13, 14 are made of, for example, steel plates. Mounting bracket 1 formed by bending and forming
7, 18, 19 are provided, respectively, and these mounting brackets 17, 18, 19 are attached to the core 16 by welding, for example.
Are fixed integrally to the As will be described later, mounting bolts are fixed to the bottoms of the mounting brackets 17, 18, and 19 through the holes 17h, 18h, and 19h. The roof rack 10 is formed by covering the outside of the core 16 to which the mounting brackets 17, 18, and 19 are integrally fixed with a surface of a predetermined synthetic resin.

In the present embodiment, the mounting bracket 17,
When covering the outside of the core member 16 with the integrally fixed members 18 and 19 with a synthetic resin skin, resin molding is performed by insert molding, and the covering resin and the insert member (the core member 16 and the mounting brackets 17 and 18) are formed. , 19). That is, the core material 16 to which the mounting brackets 17, 18, and 19 are integrally fixed is insert-fixed to a predetermined location in a molding die and mold clamping is performed. For example, in the molding space in which the insert material is held, Resin molding was performed by injection filling of a molten resin by an injection molding method. Since the insert molding method is basically the same as a well-known method, detailed description and illustration of the method itself are omitted.

In this embodiment, more preferably, FIG.
As shown by an imaginary arrow G, gates are provided at the mold portions corresponding to the left and right sides of the center mounting leg portion 13, and the molten resin is injected and filled. Therefore, the core material 1
The injection pressure of the molten resin is applied almost equally from the left and right to the relatively rigid portion due to the mounting bracket 18 being fixed at the center of the core 6, and the core material 16 is deformed by the injection pressure. Can be minimized. Then, as shown in FIG. 5, the basic cross section was set to be symmetrical. As a result, the center mounting leg 13
The amount of the molten resin charged from both the left and right sides becomes substantially equal, so that it is possible to suppress a decrease in strength at a so-called weld portion where the molten resins collide with each other.

In the present embodiment, more preferably, the above-mentioned insert material (the above-mentioned core material 16 and mounting bracket 1) is used.
7, 18, 19) is fixed to the molding die by using each mounting bracket 17,
18 and 19 were used. That is, when performing the insert molding, the mounting leg 1 of the molding die is used.
For portions corresponding to 2, 13, and 14, more preferably, so-called nesting is used. For example, as shown in FIG. 6 to FIG. 8, the nesting includes a main body portion 21 formed in a substantially rectangular parallelepiped shape, and a protrusion protruding from the main body portion 21. A pair of parallel protrusions 22 provided along the longitudinal direction of the core member 16 and an intermediate protrusion 24 provided at a substantially intermediate position of a groove 23 formed between the pair of parallel protrusions 22. Have.

Then, the mounting members 17, 17 are inserted into the groove 23 so as to sandwich the intermediate projection 22, and the mounting members 17, 17 are fixed to the main body portion 21. Fixed for. That is, the mounting bolt 31 is fixed to the bottom portion 17b of each of the mounting brackets 17 by, for example, spot welding after being inserted through the hole portion 17h.
On the back surface side of each of the mounting bolts 31, a concave portion 25 for receiving the mounting bolt 31 is formed at a portion corresponding to the mounting bolt 31, and each mounting bolt 31 protruding from the bottom 17 b of each mounting bracket 17 is formed.
Then, a nut (not shown) is screwed into each of the corresponding recesses 25, and the nuts are tightened, whereby the mounting brackets 17 are fastened and fixed to the insert 20.

As can be clearly understood from FIGS. 7 and 8, the insert 20 is inserted into a predetermined portion of one of the pair of molds M1 and M2 (in the present embodiment, for example, the mold M1) and fixed. Is done. Note that the other mounting legs 13 and 1
The nest 4 having the same structure as that for the front mounting leg 12 is also used for the front side 4. Therefore, the insert (the core 16 and the mounting brackets 17, 18, and 19) is fixed to the molding die M1 via these inserts. Then, the insert material (the core material 16 and the mounting brackets 17, 18, 1) is used.
By injecting and filling a predetermined synthetic resin into the molding space MC holding 9) in a molten state, the rack body 11 and the mounting legs 12, 13, 14 to the vehicle body are integrated with each other, and The roof rack 10 is obtained by integrally forming a coating resin 30 for covering the roof rack. This allows
The number of parts when the roof rack 10 is assembled to the vehicle body roof 2 is minimized, so that the vehicle assembly process (roof rack assembling process) and the parts management can be simplified.

In the present embodiment, an insert material (the core material 16 to which the mounting brackets 17, 18, and 19 are integrally fixed).
In order to effectively prevent shrinkage cracking at the time of solidification due to the difference in shrinkage between the resin and the coating resin 30, as a resin material to be injection-filled, a glass fiber reinforced fiber having a length of 6 to 13 mm is used. (PP) containing, for example, preferably 5 to 40% by weight, more preferably 10% by weight.
Resin was used.

The reason why the polypropylene (PP) resin is used is that it is relatively inexpensive and has a good marketability, and it is easy to obtain good moldability and relatively stable mechanical properties. The reason why the length of the glass reinforcing fiber is 6 to 13 mm is as follows.
If it is less than 6 mm, entanglement of the glass reinforcing fiber is not easily generated and the reinforcement is not sufficient. On the other hand, if it exceeds 13 mm, the glass reinforced fiber is too entangled and uniform dispersion cannot be expected, resulting in uneven strength and adversely affecting the formability. Because it has an effect.

Further, the content of the glass reinforcing fiber is adjusted to 5 to 40.
If the amount is less than 5% by weight, the material resin (PP resin) cannot be sufficiently reinforced because it is too small, so that it is difficult to effectively prevent shrinkage cracking during solidification. On the other hand, it exceeds 40% by weight. This is because too much glass reinforcing fiber is exposed on the surface of the molded article to impair its surface properties and also adversely affects moldability. In addition, the content of the glass reinforcing fiber is the roof rack 1 according to the present embodiment.
In the case of 0, it is preferably about 10% by weight in consideration of moldability, manufacturing cost, etc. in addition to the reinforcing effect required for effectively preventing shrinkage cracking during solidification.

The use of the above-mentioned synthetic resin material effectively strengthens the coating resin 30 and causes a difference in the shrinkage between the core 16 and the coating resin 30 during solidification. Shrinkage cracking can be effectively prevented.

As shown in FIG. 9, the roof rack 10 as an integral product obtained as described above has a ring-shaped seal packing 32 and a substantially rectangular protector 33 attached to each of the mounting legs 12, 13, and 14. After being attached to each other, a cap member 34 is adhesively fixed at an intermediate portion of the rack body 11, and then assembled to the vehicle body roof 2. Each mounting leg 1
When fixing the 2, 13, 14 to the vehicle body roof 2, for example, as shown in FIGS. 10 and 11, taking the case of the mounting legs 12 on the front side as an example, as shown in FIGS. The ring-shaped seal gasket 32 surrounding the mounting bolt 31 is positioned between the bottom 17b of the mounting bracket 17 and the bottom surface 4b of the groove 4 of the roof panel 3 by positioning each mounting leg 12 in the groove 4. In addition to interposing, between the bottom end surface of the coating resin 30 and the upper surface of the roof panel 3, a protector 33 for sealing between them and protecting the surface of the panel 3 is interposed. The nut 4 is inserted into a hole 4h provided in the groove bottom surface 4b, and a nut 35 is screwed into the mounting bolt 31 from the lower surface side of the roof panel 3 to be fastened and fixed.

[0022]

According to the present invention, the mounting portion to the vehicle body is formed integrally with the metal core of the rack body, and the metal core is inserted and fixed in a molding die. Since the resin molding is performed and the rack body and the mounting portion to the vehicle body are integrally formed, a roof rack in which the rack body and the mounting portion to the vehicle body are integrated and the coating resin is integrated is obtained. Thus, the number of parts can be minimized, and the vehicle assembly process (roof rack assembling process) and the component management can be simplified. In this case,
Since a polypropylene resin containing 5 to 40% by weight of glass reinforced fiber having a long fiber length of 6 to 13 mm is used as the coating resin material, the coating resin is effectively reinforced and shrinks between the core material and the coating resin. Shrinkage cracking at the time of solidification due to the difference in the rate can be effectively prevented.

Incidentally, the present invention is not limited to the above-described embodiment, but may be modified without departing from the scope of the invention.
It goes without saying that various improvements, modifications or changes in design are possible.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an automobile equipped with a roof rack according to an embodiment of the present invention.

FIG. 2 is an explanatory plan view of the roof rack.

FIG. 3 is an explanatory side view of the roof rack.

FIG. 4 is a perspective view of a core material to which each mounting bracket is integrally fixed.

FIG. 5 is an explanatory longitudinal sectional view of the roof rack shown along the line VV in FIG. 2;

FIG. 6 is a perspective view of a nest used for insert molding of the roof rack.

FIG. 7 is an explanatory longitudinal sectional view showing a portion where a nest of a molding die used for the insert molding is set.

8 is an explanatory longitudinal sectional view of the molding die shown along the line VIII-VIII in FIG. 7;

FIG. 9 is a perspective view showing the roof rack and accessories when assembled.

FIG. 10 is an explanatory longitudinal sectional view showing a fixed state of a front mounting leg of the roof rack.

11 is an explanatory longitudinal sectional view of the mounting leg portion taken along line XI-XI in FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Vehicle roof 3 ... Roof panel 10 ... Roof rack 11 ... Rack body part 12,13,14 ... Mounting leg part 16 ... Core material 30 ... Coating resin M1, M2 ... Molding mold MC ... Molding space

Claims (1)

[Claims] 1. A vehicle roof rack comprising a rack body extending in the front-rear direction of a vehicle body above a vehicle roof and a mounting portion to the vehicle body, the outside being covered with a synthetic resin, wherein the mounting portion to the vehicle body is provided. The metal core of the integrally formed rack body is insert-fixed in a molding die, and a length of 6 to 13 m is formed in a molding space in which the metal core is held.
A roof rack for vehicles, characterized in that a rack body and a mounting portion to a vehicle body are integrally formed by injecting and filling a polypropylene resin containing 5 to 40% by weight of glass reinforcing fiber of m long fiber.