JPH0597008A - Joining structure of bumper reinforcement - Google Patents

Abstract

PURPOSE:To increase the bonding strength of two members in between by allowing the engagement structure of the joining parts with each other to act so as to suppress relative deformation of an outer and an inner member with an external force in addition to the bonding strength with the members due to a bonding resin. CONSTITUTION:Joining parts 11, 12 having channel-shaped section facing each other are formed in the butting region of an inner member 3 and outer member 2 forming a closed section, and in the condition that these parts 11, 12 are engaged, the space 13 between them is filled with a bonding resin so as to join the two members 2, 3 together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bumper reinforcement joint structure in which two members are joined to each other so as to form a closed cross section by, for example, a die slide molding method.

[0002]

2. Description of the Related Art Conventionally, for example, JP-A-2-26704.
A bumper as disclosed in Japanese Patent No. 7 is mounted on a vehicle. As shown in FIG. 9, the bumper is configured by interposing a foam material 53 between a skin member 51 and a bumper reinforcement 52 which is a strength member. The bumper reinforcement 52 is formed in a closed cross section by an inner member 55 attached to a stay 54 extending from the vehicle body, and an outer member 56 having a U-shaped cross section whose peripheral edge is joined to the inner member 55.

The above bumper reinforcement 52
Is made of a hard synthetic resin, and is manufactured through the steps of manufacturing the inner member 55 and the outer member 56 and then bonding the peripheral edges. In this case, the inner member 55 and the outer member 56 are manufactured. In addition, a separate manufacturing apparatus is required, and further, a transfer operation to the joining apparatus is required, and sufficient productivity cannot be obtained.

On the other hand, as a manufacturing method capable of improving the productivity of a synthetic resin product having a closed cross-sectional shape as described above, for example, Japanese Patent Publication No. 2-38377 discloses a die slide molding method (die slide injection method, Hereinafter, the DSI method) has been proposed. As shown in FIG. 10, the manufacturing apparatus is provided with a fixed die 61, a slide die 63 that is moved up and down by a cylinder 62, and a movable die 64 that is moved toward and away from the slide die 63. Has been. The slide die 63 is formed with a primary injection sprue 66 communicating with the main sprue 65 formed on the fixed die 61. The primary injection sprue 66 on the mating surface of the slide die 63 and the movable die 64 is vertically sandwiched therebetween. At the position of the cavity 6 corresponding to the shape obtained by dividing the final molded body in two.
7.68 are provided. Further, a sprue 69 for joining is provided on the lower side of the slide die 63.

When the molten resin is injected from the injection molding machine into the main sprue 65 in the primary injection mold clamped state shown in FIG. 10, the resin is injected into the primary injection sprue as shown in FIG. 66, runner 70, gate 71
・ After 71, both cavities 67 and 68 are simultaneously filled. When this resin is solidified, split semi-finished products 72, 72 are formed in both cavities 67, 68.

After that, as shown in FIG.
Is opened from the slide mold 63, and the resin 73 solidified in the primary injection sprue 66 is removed. Next, as shown in FIG. 13A, after sliding the slide die 63 upward, the movable die 64 is moved and the die is clamped. At this time, the two semi-finished products 72, 72 are in an abutting state with each other, and the sprue 69 for joining is communicated with the main sprue 65. Then, in this secondary injection mold clamping state, for example, the bonding resin filling space 74 having a rectangular cross section is formed over the entire circumference on the outer peripheral side of the abutting surfaces of the semi-finished products 72, 72 so that the cavities 67, 68 are formed. The shape is set. Therefore, after that, in FIG.
As shown in (b), when the molten resin is injected again through the main sprue 65, the resin is filled in the joining resin filling space 74 through the joining sprue 69 and the runner 70. As a result, as shown in FIG. 14, the two semi-finished products 72, 72 are welded to each other by the bonding resin 75 solidified in the bonding resin filling space 74 to obtain a resin molded product having a closed cross-section structure.

The manufacturing method by the DSI method as described above is
The cavities 67 and 68 at the time of primary injection molding have a shape corresponding to the inner member 55 and the outer member 56, and are formed on the outer peripheral side of the abutting surface of the inner member 55 and the outer member 56, for example, the rectangular cross-sectional shape By providing the molding die in which the bonding resin filling space 74 is formed, it is possible to apply to the manufacturing of the bumper reinforcement 52 as well, which enables highly efficient production.

[0008]

However, the bumper reinforcement 5 by the DSI method as described above is used.
2 is manufactured, even if the bonding resin filled in the bonding resin filling space 74 at the time of the secondary injection is the same material as the inner member 55 and the outer member 56 molded by the primary injection, this bonding resin is The region welded to each member 55/56 has a slightly altered texture structure, and its strength is somewhat reduced from the original strength of the resin. Therefore, a gap for filling the joining resin is simply provided on the abutting surfaces of the two members 55 and 56, and the joining strength of the abutting surface depends only on the welding strength between the joining resin filled in the void and the two members. The above-described structure causes a problem that it is difficult to obtain sufficient bonding strength as bumper reinforcement.

The present invention has been made in view of the above problems, and an object of the present invention is to improve the bonding strength when the space between the abutting surfaces of the two members is filled with the bonding resin and they are bonded to each other. It is to provide a joint structure of the bumper reinforcement to be obtained.

[0010]

In order to achieve the above-mentioned object, the bumper reinforcement joining structure of the present invention is formed by abutting and joining two members so as to form a closed cross section. In the bumper reinforcement joint structure, a joint portion having a substantially U-shaped cross section facing each other is formed in the abutting region of both members,
It is characterized in that both joints are occluded and a space between the joints formed in this occlusal state is filled with a joint resin so that both members are joined to each other.

[0011]

According to the above construction, since the joints of the two members are in a state of being engaged with each other, in addition to the joint strength between the joint resin filled in the void between the joints and the respective members, The mechanical interlocking structure of the two members also suppresses the relative deformation between the two members against an external force, thereby improving the joint strength between the two members.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS.

As shown in FIG. 2, a bumper reinforcement 1 according to this embodiment includes an outer member 2 and an inner member 3 which are joined to each other so as to face each other in the front-rear direction of the vehicle (left-right direction in the drawing). It consists of Both of these members 2 and 3 are made of hard synthetic resin. The inner member 3 located on the vehicle body side (right side in the drawing) is formed in a substantially flat plate shape, and is fixed to a stay (not shown) extending from the vehicle body in a substantially vertical mounting state. The outer member 2 has a substantially U-shaped outer peripheral cross-section,
The front ends of the horizontal outer wall surfaces 2a and 2b extending toward the vehicle body, that is, the upper portion and the lower portion, are joined to the upper and lower ends of the inner member 3, respectively. In this way, the impact absorbing member 4 made of foamed resin or the like is interposed on the front side of the bumper reinforcement 1 constituted by joining the outer member 2 and the inner member 3 to each other so as to form a closed cross-sectional shape. Then, the bumper 6 is formed by applying the skin member 5 made of a relatively soft synthetic resin.

Inside the bumper reinforcement 1, flat horizontal ribs 7 and vertical ribs 8 are respectively formed.
Are provided on the outer member 2. Horizontal rib 7
Reference numeral 7 denotes a position that divides the internal space into approximately three equal parts in the height direction, and is provided over almost the entire width as shown in FIG. 4, and as shown in FIG. 2, from the vertical outer wall surface 2c of the outer member 2 to the inner member. 3 is provided in a shape reaching the vicinity of the inner surface.

On the inner surface of the inner member 3, there are formed shake restraining portions 9 and 9 each having a recessed groove at a height position corresponding to the horizontal ribs 7 and 7. These shake restraining portions 9 and 9 are formed.
The front end portions of the horizontal ribs 7 and 7 are fitted into the respective recessed grooves in the above, whereby the deflection of the horizontal ribs 7 and 7 on the front end portion side is regulated. As a result, even when the bumper reinforcement 1 is deformed in the front-rear direction at the time of a collision, the tip end side of the horizontal rib 7 does not escape from the collision direction and is obliquely deformed, so that the load in the collision direction is most effective. The state of absorption is being maintained.

As shown in FIG. 3, the vertical ribs 8 ...
A plurality of them are provided at appropriate intervals in the width direction, and as shown in FIG. 2, within the range from the vertical outer wall surface 2c of the outer member 2 to the middle position toward the inner member 3, the upper and lower horizontal outer wall surfaces of the outer member 2 are provided. 2a and 2b and horizontal rib 7
・ Provided over 7 spaces.

On the other hand, the front and rear ends of the horizontal outer wall surfaces 2a and 2b of the outer member 2 extending toward the vehicle body and the upper and lower ends of the inner member 3 joined to the horizontal outer wall surfaces 2a and 2b are, as shown in FIG. An outer joint portion 11 and an inner joint portion 12 having U-shaped cross sections facing each other are provided. The outer joint portion 11 has a bifurcated shape of an outer protruding piece 11a and an inner protruding piece 11b that are parallel to each other, and an outer recessed groove 11c is formed between these protruding pieces 11a and 11b. Further, the inner side joint portion 12 is provided with an outer side protruding piece 12a and an inner side protruding piece 12b protruding in parallel to the protruding pieces 11a and 11b, and an inner side recessed groove 12c is formed between these protruding pieces 12a and 12b. Has been formed.

The outer member 2 and the inner member 3 each having the above-mentioned joining portions 11 and 12 are joined to each other while the inner projecting piece 11b of the outer joining portion 11 is fitted in the inner recess groove 12c. Outer protrusion 12 of part 12
a is located in the outer side recessed groove 11c and is assembled with each other in an occlusal state. Then, the outer side recessed groove 11
In c, the outer protruding piece 12a of the inner side joint 12 and the outer protruding piece 11 of the outer side joint 11 located inside this
A joining resin filling space (void) 13 is formed between the joining resin and a, and a molten resin is injected into the joining resin filling space 13 and solidified as described below, whereby the above joining is performed. The parts 11 and 12 are joined to each other.

The bumper reinforcement 1 having the above structure is manufactured by the above-mentioned DSI method. In this case, as shown in FIG.
A slide die 23 that is vertically moved is provided between the movable die 22 and the movable die 22 that is movable in the contacting / separating direction (the horizontal direction in the drawing). A primary injection sprue 25, which communicates with the main sprue 24 formed on the fixed mold 21 when the slide mold 23 is in the primary injection state before sliding as shown in the figure, is formed at approximately the center of the slide mold 23. Has been done. The movable die 2 in the slide die 23
A male part 26 corresponding to the space shape between the horizontal ribs 7 and the vertical ribs 8 in the outer member 2 is provided on the upper surface of the primary injection sprue 25 on the mating surface with 2.

On the other hand, the movable die 22 is provided with a concave female die portion 27 surrounding the male die portion 26.
A space-shaped outer member cavity 28 corresponding to the outer member 2 is formed between the outer mold member 26 and the male mold portion 26. In addition, a space-shaped inner member cavity 29 corresponding to the inner member 3 is formed along the mating surface of the slide mold 23 and the movable mold 22 below the primary injection sprue 25. 23, a sprue 30 for joining is provided at a position lower than the cavity 29 for the inner member.

When the molten resin is injected from the nozzle 31 of the injection molding machine (not shown) into the main sprue 24 in the above-described primary injection state, the resin is moved from the primary injection sprue 25. The outer member cavity 28 and the inner member cavity 29 are filled with the runner 32 along the mating surface of the mold 22 and the slide mold 23 and the gates 33 and 34 provided above and below the runner 32, respectively. By solidifying, the outer member 2 and the inner member 3 are simultaneously molded.

Next, mold opening is performed to separate the movable mold 22 from the slide mold 23. At this time, the outer member 2 remains on the movable die 22 side, and the inner member 3 remains on the slide die 23 side. The solidified resin at the sprue runner gate used for the primary injection is cut off from the product and discarded outside the mold. Then, the slide mold 23 is lifted in the mold open state, and then the movable mold 22 is moved in the direction in which the movable mold 22 contacts the slide mold 23 and the mold is clamped.

At this time, as shown in FIG. 6, while the outer joint portion 11 and the inner joint portion 12 of the outer member 2 and the inner member 3 are overlapped with each other in the occlusal state described above over the entire circumference, they are fixed. The sprue 30 for joining of the slide mold 23 communicates with the main sprue 24 of 21, and
At the end of the runner 35 formed at the tip of the sprue 30 for joining, the outer member 2 and the inner member 3 are provided.
The joining resin filled space 13 in the joining region with the is communicated with.

Then, the operation of injecting the molten resin through the main sprue 24 is performed again, and as a result, the bonding resin filling space 13 is filled with the molten resin. Then, when the molten resin is solidified, the outer joint portion 1
1 and the inner side joint portion 12 are joined to each other over the entire circumference, and a bumper reinforcement 1 having a closed cross-sectional shape
Is created.

As described above, the bumper reinforcement 1 having the above structure is manufactured by injection molding by the DSI method while maintaining high productivity. In addition, horizontal ribs 7 and vertical ribs 8 are provided inside, so that the structure has high strength and rigidity.

In the above structure, in the joining region of the outer joint portion 11 and the inner joint portion 12, the outer joint portion 11 and the inner joint portion 12 having substantially U-shaped cross sections facing each other are provided in both members. It is provided in the joint region of 2.3, and after the joint portions 11 and 12 are occluded, the joint resin filling space 13 between the joint portions 11 and 12 is filled with the joint resin so that both members 2.3 are joined. It is designed to be joined together. In this case, since the above-mentioned occlusal structure also acts against this against deformation due to external force, the joint strength is also significantly larger than the above-mentioned structure that depends only on the joint strength with each member by the joint resin. In particular, the bumper reinforcement 1 has a high energy absorption performance and a high rigidity, especially with respect to buckling and twisting.

The occlusal structure of the joints 11 and 12 is not limited to the above embodiment, and the inner joint 12 is positioned outside the outer joint 11 as shown in FIG. 7, for example. It is also possible to configure it.
Further, as shown in the drawing, the bonding resin filling space 13 is formed so that gaps are formed on both inner and outer sides of the outer projecting piece 11a of the outer joint portion 11 located in the inner recess groove 12c.
By forming the above, the welding area between the members 2 and 3 by the joining resin filled in the space 13 is widened, whereby the joining strength is further improved.

Further, as shown in FIG. 8, for example, the entire outer joint portion 11 can be fitted in the inner concave groove 12c of the inner joint portion 12. In this case, as shown in the figure, the outer recessed groove 11c
Is formed so as to become the bonding resin filled space 13, and the entire space 13 is surrounded by the outer member 2 and the inner member 3. In addition, in this structure, since the bonding resin is injected in the secondary injection process, the bonding resin filling space 13 is formed.
It is necessary to provide the inner member 3 with several gate holes 15 communicating with the inner hole 3. However, the bonding resin does not appear on the surface except for the openings to the surface of these gate holes 15. For this reason, no joining line is formed on the surface, so that a bumper reinforcement having an improved aesthetic appearance can be obtained.

Further, in the above embodiment, the bumper reinforcement 1 manufactured by the DSI method has been described as an example. However, according to another manufacturing method in which the abutting points of the two members are filled with the bonding resin and bonded. The present invention can be applied to the bumper reinforcement produced.

[0030]

As described above, in the bumper reinforcement joint structure of the present invention, the joint portions having substantially U-shaped cross sections facing each other are formed in the abutting regions of the two members forming the closed cross section. It is configured such that both joints are occluded and a space between the joints formed in this occluded state is filled with a joint resin so that both members are joined to each other.

As a result, the joints of the two members are in a state of being occluded with each other. Therefore, in addition to the joint strength between the joint resin filled in the space between the joints and the members, the mechanical strength of the two members is increased. The relative occlusal structure also suppresses relative deformation between the two members against external force, and as a result, the joint strength between the two members can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a joint region between an outer member and an inner member of a bumper reinforcement according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the bumper reinforcement.

FIG. 3 is a plan view of the bumper reinforcement.

FIG. 4 is a front view of the bumper reinforcement.

FIG. 5 is a schematic cross-sectional view of a molding die when the bumper reinforcement is molded by the DSI method.

FIG. 6 is a schematic cross-sectional view of a molding die during secondary injection molding in the molding process by the DSI method.

FIG. 7 is a cross-sectional view of essential parts showing a joint region between an outer member and an inner member of a bumper reinforcement according to another embodiment of the present invention.

FIG. 8 is a cross-sectional view of essential parts showing a joint region between an outer member and an inner member of a bumper reinforcement according to still another embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a conventional bumper reinforcement.

FIG. 10 is a schematic cross-sectional view showing the configuration of a molding apparatus adopting the DSI method.

FIG. 11 is a cross-sectional view of essential parts showing a primary injection molding process in the molding apparatus.

FIG. 12 is a main-portion cross-sectional view showing a mold opening step after primary injection molding in the molding apparatus.

13A and 13B show a molding process in the molding apparatus, wherein FIG. 13A is a cross-sectional view of a main part showing a state where mold clamping for secondary injection molding is performed, and FIG. It is a principal part sectional view which shows a secondary injection molding process.

FIG. 14 is a cross-sectional view of a resin product obtained by molding with the molding device.

[Explanation of symbols]

 1 Bumper Reinforcement 2 Outer Member 3 Inner Member 11 Outer Side Joint 12 Inner Side Joint 13 Joint Resin Filling Space (void)

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Shinji Kasami Shinji Kasami, Higashi-Hiroshima City, Hiroshima Prefecture, 175-1 Oohara, Honhonmatsu-cho Daikyo Co., Ltd. (72) Inventor Shozo Nishida 1 Funakoshi-minami, Aki-ku, Hiroshima-shi, Hiroshima Prefecture Chome 6-7 Japan Steel Works Hiroshima Works

Claims (1)

[Claims] 1. In a joint structure of a bumper reinforcement formed by abutting and joining two members so as to form a closed cross section, substantially U-shaped cross sections facing each other in an abutting region of both members. Are joined to each other, and the joint resin is filled in the space between the joints formed in this occlusal state, and both members are joined to each other. Bumper reinforcement joint structure.