JP4597000B2 - Bumper rubber and bumper rubber manufacturing method - Google Patents

Description

  The present invention relates to a bumper rubber and a bumper rubber manufacturing method for mitigating an impact when closing an opening / closing body such as a trunk lid of an automobile.

  For example, a bumper rubber is provided on the periphery of a vehicle body opening to which a trunk lid of an automobile is attached. This bumper rubber reduces the impact force when closing the trunk lid and prevents the trunk lid from vibrating when the vehicle is running.

As a conventional bumper rubber, the thing of patent document 1 is known, for example. As shown in FIG. 8 of Patent Document 1, an upper portion and a lower portion are provided to close the upper and lower ends of the cylindrical side wall portion, and columnar protrusions projecting inward in the axial direction from above or below to a portion surrounded by the side wall portion. While forming integrally with the upper part or the lower part, the inner peripheral surface of the side wall part is provided with a protruding part. When overcompressed, the lower or upper end of the columnar protrusion abuts the upper surface of the lower part or the lower surface of the upper part, and a high reaction force Can be obtained.
JP-A-7-145840

  However, the cylindrical side wall portion and the internal columnar protrusions must be formed by separate molds and combined with each other, and the forming process is performed a plurality of times, which complicates the manufacturing process. This is because the core shape of the mold becomes complicated if it is to be manufactured in a single molding process, and it cannot be removed.

  On the other hand, if the structure is provided with openings on both sides of the side wall, it can be manufactured in a single molding process, but if a compressive force acts obliquely from the direction having the openings, a predetermined resilience is obtained. There is a problem that it cannot be obtained.

  Then, this invention solves said subject and aims at providing the manufacturing method of a bumper rubber and bumper rubber which can form a cylindrical part and a columnar part simultaneously by one shaping | molding.

The invention which concerns on Claim 1 is located inside the cylindrical part of a bottomed cylindrical shape, and the one end side of this cylindrical part, and the end surface of one end side occupies the substantially the same position as the end surface of the one end side of the said cylindrical part. A cylindrical portion and a cylindrical shape interposed between the cylindrical portion and the columnar portion, one end side is integrally formed with one end side of the cylindrical portion, and the other end side is integrally formed with the other end side of the columnar portion. A connecting portion, a locking portion that is integrally formed on the bottom portion of the tubular portion and is attached to a mounted member, and the inside and outside of the tubular portion are communicated in the axial direction through the bottom portion and the locking portion. possess a communication hole, and the cylindrical portion, said cylindrical portion and the connecting portion integrally formed at one end of, the molded member made of said columnar portion integrally formed at one end of the connecting portion is formed as, to characterized in that said columnar portion and the connecting portion is formed is pushed into the interior of one end of the tubular portion .

  According to the present invention, when the cylindrical portion is compressed in the axial direction, the cylindrical portion is deformed to obtain a substantially constant reaction force. When further compressed, the columnar part comes into contact with the bottom, so that the columnar part is also compressed at the same time in addition to the cylindrical part, and both the cylindrical part and the columnar part are deformed, so that a higher reaction force can be obtained. .

Moreover, after forming the molding member which connected and integrated the cylindrical part, the connection part, and the columnar part in the axial direction, the columnar part and the connection part 4 are connected to one end side of the cylindrical part. The bumper rubber can be obtained only by molding once.

  According to a second aspect of the present invention, in the bumper rubber according to the first aspect, a dividing groove is formed at a position that intersects the communication hole and divides the locking portion.

  According to the present invention, since the split groove is present, the two divided locking portions are easily separated from each other, and the communication hole formed in the locking portion is easily expanded. The operation of removing the core from the inside of the molded member becomes easy.

According to a third aspect of the present invention, the bottomed cylindrical tubular portion and the end surface on one end side of the cylindrical portion occupy substantially the same position as the end surface on the one end side of the cylindrical portion. A cylindrical portion and a cylindrical shape interposed between the cylindrical portion and the columnar portion, one end side is integrally formed with one end side of the cylindrical portion, and the other end side is integrally formed with the other end side of the columnar portion. The connecting portion, a pair of communication holes that penetrate the bottom portion of the cylindrical portion and communicate the inside and the outside of the cylindrical portion in the axial direction, and the cylinder embedded in the bottom portion between the pair of communication holes projects to Jo of the outer possess a locking member mounted on the mounting member, and the tubular portion, and the connecting portion integrally formed at one end of the tubular portion, one end of the connecting portion Formed as a molding member composed of the columnar part integrally formed on the side, and the columnar part and the connecting part are inside one end side of the cylindrical part Characterized in that it is configured pushed in.

  According to this invention, the core used for molding the molded member is divided into two parts, and the two cores inside the molded member molded by molding are taken out from the pair of communication holes. Good mold release. Further, since the locking member is embedded in the bottom, only the shape of the locking member can be changed independently, and the degree of freedom of the shape of the locking member is high.

  According to a fourth aspect of the present invention, in the bumper rubber according to the third aspect, the locking member is formed of a hard resin.

  According to this invention, since the locking member is formed of the hard resin, the mounting state of the bumper rubber to the mounted member is stabilized, and the assembling property and holding property of the bumper rubber are improved.

A bumper rubber manufacturing method according to a fifth aspect of the present invention includes a bottomed tubular cylindrical portion, a connecting portion integrally formed on one end side of the tubular portion, and an integrally formed end portion of the connecting portion. After forming a molding member composed of a columnar part, the columnar part and the connecting part are pushed into the one end side of the cylindrical part.

According to this invention, after forming the molding member integrally connecting the cylindrical portion, the connecting portion, and the columnar portion in the axial direction, the columnar portion and the connecting portion are connected to one end side of the cylindrical portion. By pushing into the inside, a bumper rubber having a columnar part inside one end side of the cylindrical part is obtained.

According to the bumper rubber according to the first and third aspects, since the cylindrical connecting portion is interposed between the cylindrical portion and the columnar portion, the cylindrical portion, the connecting portion, and the columnar portion are continuous in the axial direction. Forming a simple molded member having a shape integrally connected to each other by mold molding, and then pushing a columnar portion and a connecting portion of the molded member into one end side of the cylindrical portion to constitute a bumper rubber Is possible.

  According to the bumper rubber according to the fourth aspect, the assembling property and holding property of the bumper rubber are improved.

According to the bumper rubber manufacturing method according to claim 5, after forming the molding member integrally connecting the cylindrical portion, the connecting portion, and the columnar portion in the axial direction, the columnar portion , the connecting portion, The bumper rubber having the columnar part inside the one end side of the cylindrical part is configured by pushing the cylinder part into the one end side of the cylindrical part, so that the cylindrical part and the columnar part are originally formed by two moldings. A bumper rubber obtained by individually molding and then combining the two can be obtained by only one molding.

Hereinafter, embodiments of the bumper rubber according to the present invention will be described.
(A) Embodiment 1
First, the first embodiment is shown in FIG. FIG. 1A shows a perspective view of the bumper rubber, and FIG. 1B shows a cross-sectional view of the bumper rubber. The bumper rubber 1 is made of rubber or a thermoplastic elastomer.

The bumper rubber 1 has a cylindrical portion 2 having a bottomed cylindrical shape, and an upper portion inside the cylindrical portion 2 that is one end side, and has an upper end surface that is substantially the same position as the upper end surface of the cylindrical portion 2. The columnar portion 3 occupies and a thin cylindrical shape interposed between the columnar portion 3 and the cylindrical portion 2 when viewed in the radial direction in relation to the inner side and the outer side, the upper end side being the cylindrical portion 2 is integrally formed with the upper end side of 2 and the lower end side is integrally formed with the lower end side of the columnar part 3, and is mounted on a member to be mounted for mounting the bumper rubber 1 integrally formed on the bottom part 2 a of the cylindrical part 2. And a communication hole 6 that penetrates the bottom portion 2a and the locking portion 5 and communicates the inside and outside of the cylindrical portion 2 in the axial direction. The hollow portion 7 is formed inside the cylindrical portion 2. Is formed.

  Next, the manufacturing method of this bumper rubber 1 is demonstrated. To manufacture the bumper rubber 1 shown in FIG. 1, first, the mold forming member 1a shown in FIG. 2 is formed. This mold forming member 1a includes a bottomed cylindrical tubular portion 2 having a hollow portion 7, a connecting portion 4 formed integrally with an upper end on one end side of the tubular portion 2, and an upper end of the connecting portion 4. And a locking portion 5 that is integrally formed with the bottom portion 2a of the cylindrical portion 2 and protrudes downward.

  The mold forming member 1a shown in FIG. 2 is formed using the mold 10 shown in FIG. The mold 10 includes a substantially bottomed cylindrical mold 10a, molds 10b and 10c having a two-part structure, and a mold 10e integrated with a core 10d. In the state of FIG. 5, a rubber material is injected into a mold 10 from a nozzle (not shown) and molded. After the mold 10 a is moved upward and demolded, the molds 10 b and 10 c are separated in the horizontal direction. Let them demold. Finally, the core 10d is extracted from the hollow portion 7 of the molding member 1a through the communication hole 6.

2 is completed, the columnar part 3 and the connecting part 4 are pushed into the upper part, which is one end side of the cylindrical part 2. Then, as shown in FIG. 1B, the bumper rubber 1 in a state where the connecting portion 4 is interposed between the cylindrical portion 2 and the columnar portion 3 is completed.

According to the present invention, after forming the mold forming member 1a in which the cylindrical portion 2, the connecting portion 4, and the columnar portion 3 are continuously connected in the axial direction and integrated, the columnar portion 3 and the connecting portion 4 are connected to the cylinder. The bumper rubber 1 having the columnar portion 3 inside the one end side of the tubular portion 2 is obtained by pushing into the inside of the one end side of the shaped portion 2.

  Next, the operation of the bumper rubber 1 will be described with reference to FIG. As shown in FIG. 3A, the bumper rubber 1 is mounted by fitting the locking portion 5 into an attachment hole 11 a formed in the mounted member 11.

When the trunk lid is closed or the vehicle is running, the bumper rubber 1 is compressed in the axial direction by the trunk lid 12 as shown in FIG. At this time, only the cylindrical portion 2 is first compressed, and the cylindrical portion 2 is deformed to obtain a substantially constant reaction force. Next, when the trunk lid 12 is suddenly closed or when the trunk lid 12 vibrates and becomes overcompressed when the vehicle is running, the tubular portion 2 is further moved as shown in FIG. When compressed and deformed, the lower end of the columnar portion 3 comes into contact with the upper surface of the bottom portion 2a, and the columnar portion 3 is also compressed at the same time, so that both the cylindrical portion 2 and the columnar portion 3 are deformed, thereby obtaining a higher reaction force. . FIG. 4 shows the relationship between the deflection (compression amount) generated in the bumper rubber 1 and the load (reaction force). (A) in a figure shows the range where only the cylindrical part 2 is compressed, (b) shows the range where the cylindrical part 2 and the columnar part 3 are compressed simultaneously.
(B) Embodiment 2
Next, Embodiment 2 is shown in FIG. Since the second embodiment is obtained by changing a part of the first embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals, the description thereof is omitted, and only different parts are described.

  As shown in the figure, a dividing groove 5a is formed at the position of the locking portion 5 along the radial direction at a position where the locking portion 5 is divided across the communicating hole 6 passing through the axial center position. .

  Due to the presence of the dividing groove 5a, the two divided locking portions 5 are easily separated from each other, and the communication hole 6 formed in the locking portion 5 is easy to expand. After the molding, the operation of extracting the core 10d from the communication hole 6 of the mold forming member 1a becomes easy.

Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.
(C) Embodiment 3
Finally, Embodiment 3 is shown in FIG. Since the third embodiment is also a part of the first embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and only different parts are described.

  In the bumper rubber 1 according to the third embodiment, a pair of communication that connects the inside and outside of the cylindrical portion 2 in the axial direction through the bottom portion 2a integrally formed at the lower end that is the other end of the cylindrical portion 2. A hole 6a is formed, and a locking member 13 is provided between the pair of communication holes 6a so as to protrude downward while being embedded in the bottom 2a. The locking member 13 is made of hard resin.

  FIG. 8 is a cross-sectional view of the molded member 1a in a state before the bumper rubber 1 is formed. The locking member 13 protrudes downward in the figure, which is the outside of the cylindrical portion 2, and the locking member 13 is mounted in a mounting hole of a mounted member (not shown). The locking member 13 is provided with a pair of claws 13a protruding downward, and a retaining projection 13b is formed at the base of each claw 13a. Therefore, when the locking member 13 is fitted into the mounting hole of the mounted member, the pair of claws 13a are spread by the elastic force of the hard resin.

  FIG. 9 shows a mold 14 for producing the molded member 1a of FIG. The mold 14 is composed of a substantially bottomed cylindrical mold 14a identical to the mold 10a, molds 14b and 14c having a split structure, and a pair of cores 14d having a split structure. Yes. Grooves 15 into which rubber material enters and form the bottom 2a of the bumper rubber 1 are formed on the opposing surfaces where the pair of cores 14d are brought together, and below the grooves 15 in FIG. Recesses 16 for holding the stop member 13 are formed.

  In order to manufacture the molded member 1a of FIG. 8, the locking member 13 is formed in advance. Next, by fitting the locking member 13 into the recess 16 in FIG. 9, the locking member 13 is sandwiched between the pair of cores 14 c, and the base end portion of the locking member 13 is placed inside the groove 15. In a state of entering, a rubber material is injected into the mold 14 from a nozzle (not shown). After the molding, the mold 14a is moved upward and removed, and then the molds 14b and 14c are separated in the left-right direction and removed. Finally, the core 14d having a two-part structure is extracted from the hollow portion 7 of the molded member 1a. Since the communication hole of the molding member 1a is divided into two as described above to form a pair of communication holes 6a, the two cores 14c are respectively taken out from the respective communication holes 6a. Further, since the locking member 13 is embedded in the bottom portion 2a, only the shape of the locking member 13 can be changed independently, and the degree of freedom of the shape of the locking member 13 is high.

When the molding member 1a of FIG. 8 is thus completed, when the columnar portion 3 and the connecting portion 4 are pushed into the upper part which is one end side of the cylindrical portion 2 as in the first embodiment, FIG. The bumper rubber 1 shown is completed.
The bumper rubber 1 is mounted on the bumper rubber 1 by pushing the pair of claws 13a of the locking member 13 into mounting holes (not shown) formed in the mounted member. Since the retaining protrusion 13b is caught inside the mounting hole by the mounting, the bumper rubber 1 does not fall out of the mounting hole.

  According to the present invention, since the locking member 13 is formed of a hard resin, the mounting state of the bumper rubber 1 to the mounted member is stabilized, and the assembling property and holding property of the bumper rubber 1 are improved. When the trunk lid 12 is suddenly closed or when the trunk lid 12 vibrates and becomes overcompressed when the vehicle is traveling, the lower end of the columnar portion 3 comes into contact with the upper surface of the bottom portion 2a. A higher reaction force can be obtained.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

  In this embodiment, the bumper rubber is formed of rubber or thermoplastic elastomer, but the material is not limited to rubber or thermoplastic elastomer as long as it is elastically deformable.

FIG. 4A is a perspective view of a bumper rubber, and FIG. Sectional drawing which shows the state of the molding member of a bumper rubber (Embodiment 1). Action | operation explanatory drawing of bumper rubber (Embodiment 1). The graph which shows the relationship between the load added to a bumper rubber, and bending (Embodiment 1). Sectional drawing which shows the metal mold | die which shape | molds a shaping | molding member (Embodiment 1). The perspective view of a bumper rubber (embodiment 2). A perspective view of a bumper rubber (embodiment 3). It relates to the state of the molded member of the bumper rubber, (a) is a front view, (b) is a side view (Embodiment 3). Sectional drawing which shows the metal mold | die which shape | molds a shaping | molding member (Embodiment 3).

DESCRIPTION OF SYMBOLS 1 ... Bumper rubber 1a ... Molding member 2 ... Cylindrical part 2a ... Bottom part 3 ... Column part 4 ... Connection part 5 ... Locking part 5a ... Dividing groove 6, 6a ... Communication hole 13 ... Locking member

Claims (5)

A cylindrical portion having a bottomed cylindrical shape, a columnar portion located inside one end side of the cylindrical portion, and having an end face on one end side occupying substantially the same position as an end face on one end side of the cylindrical portion, and the cylindrical portion And a connecting portion in which one end side is integrally formed with one end side of the cylindrical portion and the other end side is integrally formed with the other end side of the columnar portion. It possesses a locking portion which is integrally formed at the bottom parts are mounted to the mounting member, and a communicating hole for penetrating the bottom portion and the locking portion communicates the inside and outside of the cylindrical portion in the axial direction,
The columnar part is formed as a molding member comprising the cylindrical part, the connecting part integrally formed on one end side of the cylindrical part, and the columnar part integrally formed on one end side of the connecting part. The bumper rubber is characterized in that the connecting portion is pushed into the one end side of the cylindrical portion .   2. The bumper rubber according to claim 1, wherein a dividing groove is formed at a position that intersects the communication hole and divides the locking portion. 3. A cylindrical portion having a bottomed cylindrical shape, a columnar portion located inside one end side of the cylindrical portion, and having an end face on one end side occupying substantially the same position as an end face on one end side of the cylindrical portion, and the cylindrical portion And a connecting portion in which one end side is integrally formed with one end side of the cylindrical portion and the other end side is integrally formed with the other end side of the columnar portion. A pair of communicating holes that pass through the bottom of the portion to communicate the inside and outside of the cylindrical portion in the axial direction, and are embedded in the bottom portion between the pair of communicating holes and project outside the tubular portion It possesses a locking member mounted to the mounting member,
The columnar part is formed as a molding member comprising the cylindrical part, the connecting part integrally formed on one end side of the cylindrical part, and the columnar part integrally formed on one end side of the connecting part. The bumper rubber is characterized in that the connecting portion is pushed into the inside of one end side of the cylindrical portion .   4. The bumper rubber according to claim 3, wherein the locking member is made of a hard resin. After forming a molded member composed of a cylindrical portion having a bottomed cylindrical shape, a connecting portion integrally formed on one end side of the cylindrical portion, and a columnar portion integrally formed on one end side of the connecting portion, method for producing a bumper rubber according to any one of claims 1 to 4, characterized by being configured pushing and said columnar portion and the connecting portion inside the one end side of the tubular portion.

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