JP4300996B2 - Method for producing impact energy absorbing material - Google Patents

Description

The present invention relates to a method for producing an impact energy absorbing material (hereinafter abbreviated as EA material ) .

  An EA material made of hard urethane is attached to a door trim of an automobile for energy absorption (EA) at the time of a side collision (side collision). As a method of attaching a hard urethane EA material to this door trim, Japanese Patent Application Laid-Open No. 2001-322507 describes the structure shown in FIGS. FIG. 7 is a cross-sectional view showing the EA material mounting structure described in FIG. 7 of the publication, FIG. 8 (a) is a perspective view of the cylindrical body 20 used in this structure, and FIG. b) is a cross-sectional perspective view of the cylindrical body 20.

  The cylindrical body 20 is integrally provided with a cylindrical portion 21 and an overhang portion 22. A claw portion 23 is provided inward from the tip of the tube portion 21. A concave portion 27 is provided on the outer peripheral surface of the rod 26 protruding from the trim 31, and the claw portion 23 is engaged with the concave portion 27.

  Note that a slit 24 extends from the tip of the tube portion 21 in a direction parallel to the axial center line of the tube portion 21, and the tube portion 21 can be elastically deformed in the diameter increasing direction.

  To attach the EA material 33 to the trim 31, place the EA material 33 along the surface of the trim 31 so that the rod 26 is inserted into the attachment hole 34 of the EA material 33, and then fit the cylindrical body 20 to the rod 26. Then, the claw portion 23 is engaged with the concave portion 27. Thereby, the overhanging portion 22 presses the peripheral edge portion of the mounting hole 34 of the EA material 33.

  The cylindrical portion 21 has a tapered shape that is easy to insert into the mounting hole 34. When the cylindrical body 20 is mounted on the rod 26, the outer peripheral surface of the cylindrical portion 21 is in close contact with the inner peripheral surface of the mounting hole 34.

  In this EA material mounting structure, since the cylindrical body 20 and the EA material 33 are separate, when attaching the EA material to the trim 31, the work of applying the EA material to the trim 31 Then, two work steps, that is, the work of fitting the cylindrical body 20 to the rod 26 are required, and the work is troublesome.

  The structure shown in FIG. 9 is considered as an EA material attachment structure in which the workability of attaching the EA material to a member such as a trim is remarkably improved. FIG. 9 (a) is a cross-sectional view in the substantially horizontal direction showing the attachment structure of the EA material, FIG. 9 (b) is a perspective view of a locking portion of the attachment structure of the EA material, and FIG. It is a perspective view of the to-be-latched part of the attachment structure of this EA material.

  An EA material 1 made of a synthetic resin such as rigid urethane foam is attached to a trim (for example, door trim) 2 as a member via a locking portion 3 and a locked portion 4 called a clip. The locked portion 4 is provided on the EA material 1, and the locking portion 3 is engaged with the locked portion 4.

  The locking portion 3 is composed of a pair of protrusions 8 and 8 erected from the trim 2. A claw portion 8a is provided on the side surface of the protrusion 8 in the protruding direction so as to protrude laterally. As the claw portion 8a approaches the substantially semi-cylindrical portion 8b constituting the proximal end side of the protrusion 8, the protruding height toward the side increases. Thereby, the protrusions 8 and 8 can be easily inserted into the opening 12 of the locked portion 4 described later.

  The protrusion 8 is formed of a synthetic resin having elasticity, and the protrusions 8 and 8 can be elastically deformed in the approaching direction.

  The locked portion (clip) 4 includes a cylindrical portion 6, an anchor 5 that protrudes outwardly from the rear end of the cylindrical portion 6, and a flange 7 that protrudes outwardly from the distal end of the cylindrical portion 6. Have The locked portion 4 is provided with a cylindrical opening 12 penetrating the flange 7, the cylindrical portion 6, and the anchor 5 in the axial center line direction. A step 13 is recessed in the direction.

  As shown in FIG. 9 (a), the locked portion 4 has a cylindrical portion 6 and an anchor 5 embedded in the EA material 1.

  The EA material 1 with the locked portion 4 is attached to the trim 2 by applying the projections 8 and 8 to the trim 2 while inserting them into the openings 12. When the EA material 1 is pressed against the trim 2, the protrusions 8 and 8 are pushed into the opening 12. When the claw portion 8a is pressed against the inner peripheral surface of the opening 12, the protrusions 8 and 8 are inserted into the opening 12 while being bent in the approaching direction. When the claw portion 8a reaches the step portion 13, the protrusions 8 and 8 try to return to the original shape elastically, and the claw portion 8a and the trim 2 sandwich the edge portion of the step portion 13. Further, the outer peripheral surfaces of the substantially semi-cylindrical portions 8 b and 8 b of the protrusions 8 and 8 come into contact with the inner peripheral surface of the opening 12 of the locked portion 4.

  As described above, the EA material 1 can be attached to the trim 2 only by one work process of superimposing the EA material 1 with the locked portion 4 on the trim 2, and the attachment work efficiency is remarkably improved. Further, the claw portions 8a, 8a of the projections 8, 8 and the trim 2 sandwich the edge of the step portion 13, and the outer peripheral surfaces of the substantially semi-cylindrical portions 8b, 8b are in contact with the inner peripheral surface of the opening 12. The EA material 1 is immovable in both the surface direction and the contact / separation direction of the trim 2, and the attachment of the EA material 1 becomes extremely firm.

  As shown in FIG. 9 (a), the locked portion 4 has a part of its flange 7, a cylindrical portion 6 and an anchor 5 embedded in the EA material 1. Thus, since the locked portion 4 does not penetrate the EA material 1 and the EA material 1 has a sufficient thickness even in the vicinity of the locked portion 4, in the vicinity of the locked portion 4. The EA material 1 also has good shock absorption characteristics.

  However, in the EA material 1 with the clip (attachment material) 4 of FIG. 9, the clip 4 is held on the inner surface of the mold by a pin, and foam molding of urethane or the like is performed in the mold. However, if the clip 4 is pushed by the foaming resin and moves, the molding will be defective. I want to keep the clip firmly in the mold until it foams, but it must be easily removed from the pin when demolding. I want to absorb the variation of the pin and the clip and secure the above-mentioned fitting force stably.

  Therefore, it is possible to easily and firmly hold the insert on the inner surface of the mold and to easily remove the insert from the pin at the time of demolding, a foam molding method using this structure, and this structure. As a method of manufacturing a clip that can be used in the method and an EA material including the clip, a method of manufacturing an EA material shown in FIGS. 10 to 13 is considered.

  FIG. 10 (a) is a longitudinal sectional view showing the relationship between the EA material mounting clip and the mold in this method, and FIG. 10 (b) is a partially enlarged sectional view of the mold holding the clip. FIG. 4 is an exploded perspective view of the clip. FIG. 12 is a perspective view showing the engagement relationship between the clip and the mold, and FIG. 13 is a cross-sectional view showing a method of attaching the EA material provided with the clip to the trim.

  The EA material attaching clip 40 includes a clip main body 41 and a sealing body 48 attached to one end face of the clip main body 41 (upper end face in FIG. 1).

  The clip 40 is made of a synthetic resin injection-molded product, and has a through hole 42 penetrating from one end face (lower end face in the figure) to the other end face (upper end face in the figure).

  The through hole 42 has a large-diameter portion 42a and 42c at one end side and the other end side, and a small-diameter portion 42b between the two. A stepped portion 43 is formed between the small diameter portion 42b and the large diameter portion 42c.

  An outwardly hooked anchor 44 is provided on the other end side of the clip 40. A flange portion 45 is provided on one end side. A portion adjacent to the flange portion 45 is a tapered portion 46.

  A ridge 47 is provided on the inner surface of the small diameter portion 42b. In this embodiment, the ridges 47 are formed of ribs extending in the insertion / extraction direction of the clip locking pin 50, and are arranged on both sides with the center of the small diameter portion 42b interposed therebetween.

  A sealing body 48 is attached to the end face of the clip 40 on the anchor 44 side. The sealing body 48 closes the through hole 42 from the upper side in the figure.

  The sealing body 48 has a thin plate shape and is formed separately from the clip main body 41.

  In this embodiment, screw holes 44 a and 48 a are provided in the anchor 44 and the sealing body 48, and the sealing body 48 is fixed to the clip 60 by hitting the screws 49 into the screw holes 44 a through the screw holes 48 a.

  As shown in FIG. 13, the clip 40 is integrated with the EA material 1 so that most of the clip 40 is embedded in the EA material 1.

  The EA material 1 with the clip 40 is manufactured by attaching the clip 40 to the molding die 59 via the clip locking pin 50 as the clip locking projection when the EA material 1 is formed into a foam. Since the through hole 42 of the clip 40 is sealed by the sealing body 48 on the anchor 44 side, urethane or the like does not enter the through hole 42.

  The clip locking pin 50 includes a pedestal portion 51, a rectangular column portion 52 erected from the pedestal portion 51, and a tapered portion 53 at the tip of the rectangular column portion 52. The pedestal 51 is fixed to the mold 59 with screws, bolts or the like.

After completion of the foam molding, the molded body is removed from the mold 59, whereby the EA material 1 with the clip 40 is obtained. Thus, the EA material 1 is attached to the trim or the like so as to insert the engaging portion 3 protruding from the trim or the like as shown in FIG. 13 into the clip 40 provided on the EA material 1.
JP 2001-322507 A

  The method shown in FIGS. 10 to 13 requires a sealing body 48 for preventing a resin such as urethane from entering the through hole 42 during foaming of the EA material.

An object of this invention is to provide the manufacturing method of the EA material which does not require this sealing body and is very easy to manufacture.

  The manufacturing method of the EA material of the present invention (Claim 1) is a method for manufacturing an EA material in which an EA material mounting clip is integrated by insert molding, and the clip engagement is performed from the inner surface of the EA material molding die. The clip has a through hole into which the pin is inserted, and the clip is inserted into the through hole to hold the clip on the inner surface of the mold. An EA material manufacturing method in which an EA material is foam-molded, wherein a pedestal portion is provided on the base end side of the pin, and the entire periphery of the pedestal portion is in close contact with the inner peripheral surface of the through hole And performing the foam molding.

  According to a second aspect of the present invention, there is provided a method for producing an EA material according to the first aspect, wherein an intermediate portion of the pin in the protruding direction is in contact with the inner surface of the through hole.

  According to a third aspect of the present invention, there is provided the manufacturing method of the EA material according to the second aspect, wherein a protrusion that abuts on a side surface of the pin is provided in an intermediate portion of the inner surface of the through hole in the hole axial direction. It is a feature.

  The method for producing an EA material according to claim 4 is characterized in that, in claim 3, the ridges extend in a direction orthogonal to the hole axial direction of the through hole.

  The method for producing an EA material according to claim 5 is characterized in that, in claim 4, the ridges are arranged on both sides of the center of the through hole.

  The method for producing an EA material according to claim 6 is the method according to any one of claims 1 to 5, wherein the clip has a symmetrical shape with a plane passing through the middle of the hole axis direction and perpendicular to the hole axis direction as a symmetry plane. It is characterized by becoming.

  According to the manufacturing method of the EA material of the present invention, since the entire circumference of the pedestal portion on the pin base end side is in close contact with the inner peripheral surface of the through hole of the clip, a resin such as urethane is inserted into the through hole of the clip during foam molding. It hardly penetrates into the inside. That is, since the one end side (mold inner surface side) of this through hole is hermetically sealed by the pedestal portion, the through hole becomes an air reservoir without air escape. Therefore, urethane or the like hardly enters the through hole from the other end side.

  Therefore, according to the present invention, the sealing body 48 which is essential in the manufacturing method of the EA material shown in FIGS. 10 to 13 is not required, the manufacture of the clip is facilitated, and the cost can be reduced.

  According to the second aspect of the present invention, when the intermediate portion in the protruding direction of the pin is brought into contact with the inner surface of the clip through hole, the mounting direction of the clip can be determined and the mounting of the die of the clip becomes stable.

  As described in claim 3, when a protrusion is provided in the middle of the through hole, the sliding area between the pin and the through hole at the time of inserting the pin into the through hole is reduced by bringing the pin into contact with the protrusion. The clip becomes smaller and the clip can be easily attached.

  As described in claims 4 and 5, the ridges are perpendicular to the direction of the hole axis of the through-holes, and two ridges are provided so as to be opposed to each other. Used for hooking the stopper).

  According to the sixth aspect of the present invention, in the present invention, the clip can have a symmetrical shape in the hole axis direction. As a result, the clip can be mounted in any direction, and the clip can be mounted on the mold very easily.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 (a) is a longitudinal sectional view showing the relationship between an EA material mounting clip and a mold according to one embodiment of the present invention, and FIG. 1 (b) is a partially enlarged sectional view of a mold holding the clip. 2 is a cross-sectional view taken along the line II-II of FIG. 1 (a), FIG. 3 is a perspective view showing the engagement relationship between the clip and the mold, and FIGS. 4 and 5 are EA equipped with the clip. Sectional drawing which shows the attachment method to the trim of a material, FIG. 6 is a principal part perspective view of a trim.

  The clip 60 is made of a synthetic resin injection-molded product, and has a through hole 62 penetrating from one end surface (lower end surface in the figure) to the other end surface (upper end surface in the figure). In this form, the through hole 62 is a square hole shape, and the clip locking pin 70 described later is a prismatic shape, but these may be a round hole shape and a cylindrical shape.

  The through hole 62 has a large diameter portion 62a and 62c at one end side and the other end side, and a small diameter portion 62b between the two.

  Flange portions 65 are provided at both ends of the clip 60 in the hole axial direction.

  A ridge 67 is provided on the inner surface of the small diameter portion 62b. In this embodiment, the ridge 67 is formed of a rib extending in a direction orthogonal to the insertion / extraction direction of the clip locking pin 70 and is arranged on both sides with the center of the small diameter portion 62b interposed therebetween.

  The clip 60 is integrated with the EA material 1 so that most of the clip 60 is embedded in the EA material 1 as shown in FIG.

  The EA material 1 is made of, for example, a synthetic resin foam such as urethane, similar to those shown in FIGS. The EA material 1 with the clip 60 is manufactured by attaching the clip 60 to the molding die through the clip locking pin 70 as the clip locking projection during molding of the synthetic resin foam. Since the base end side of the through hole 62 of the clip 60 is sealed by a pin base portion 71 described below, urethane or the like hardly enters the through hole 62. That is, the pedestal 71 is in airtight contact with the entire circumference of the inner surface of the through hole 62 on the mold 80 side, so that the through hole 62 has a bag path shape without air escape. For this reason, the inside of the through-hole 62 becomes an air pool at the time of foam molding, and urethane or the like hardly enters the through-hole 62. Further, by making the pin base portion 71 and the large-diameter portions 62a and 62c into a round shape, the workability and the accuracy are improved, and it is easy to manufacture (can be easily sealed).

  The clip locking pin 70 includes a pedestal portion 71 and a rectangular column portion 72 erected from the pedestal portion 71. The corner edge of the pedestal 71 on the side of the prism portion 72 is chamfered obliquely so that it can be easily fitted into the large diameter portion 62a. The pedestal 71 is fixed to the mold 80 with screws, bolts or the like.

  The prism portion 72 is inserted into the small diameter portion 62b, and at this time, the protrusion 67 is pressed against the outer surface of the prism portion 72. As a result, the mounting direction is determined, and the clip 60 is firmly held by the mold 80 via the clip locking pin 70, and the clip 60 does not move even during foam molding. Since the clip 60 is made of synthetic resin, the ridge 67 is deformed substantially elastically and is in close contact with the clip locking pin 70.

  After completion of the foam molding, the molded body is removed from the mold 80, whereby the EA material 1 with the clip 60 is obtained. The clip 60 can be firmly held on the mold 80, but can be set to a fitting force that can be easily removed when the mold is removed.

  In this way, the EA material 1 is attached to the trim or the like by inserting the locking portion 3 ′ protruding from the trim or the like as shown in FIGS. 4 to 6 to the clip 60 provided on the EA material 1. .

  In addition, this clip 60 has the through-hole 62, and does not have an undercut part. For this reason, the clip 60 can be easily manufactured by injection molding using a mold having a simple structure.

  Each of the above forms is an example of the present invention, and the present invention may take forms other than those illustrated. For example, the number of ridges 67 may be larger than shown. The shape of the ridge 67 may be other than illustrated. The clip locking pin 70 may be made of metal or synthetic resin.

It is sectional drawing which shows the engagement relationship of the clip concerning one form of this invention, and a metal mold | die. It is the II-II sectional view taken on the line of FIG. It is a perspective view which shows the engagement relationship of the clip of FIG. 1, and a clip locking pin. It is sectional drawing which shows the engagement relationship of the clip of FIG. 1 provided in EA material, and a latching | locking part. It is sectional drawing after the engagement of FIG. It is a perspective view of the latching | locking part provided in the trim. It is sectional drawing which shows the EA material attachment structure using the conventional clip. It is explanatory drawing of the clip of FIG. It is explanatory drawing which shows the EA material attachment structure to the trim which concerns on a reference example. It is explanatory drawing which shows the EA material attachment structure to the trim which concerns on another reference example. It is a perspective view of the clip of FIG. It is a perspective view which shows the state which attaches the clip of FIG. 10 to a metal mold | die. It is sectional drawing which shows the EA material with a clip of FIGS.

Explanation of symbols

60 Clip 62 Through-hole 65 Flange part 67 Projection 70 Pin for clip locking 71 Base part 72 Square column part 80 Mold

Claims (6)

In a method for producing an impact energy absorbing material obtained by integrating an impact energy absorbing material mounting clip by insert molding,
The clip locking pin protrudes from the inner surface of the impact energy absorbing material molding die,
The clip includes a through hole into which the pin is inserted,
An impact energy absorbing material manufacturing method in which the pin is inserted into the through hole and the clip is held on the inner surface of a mold, and the impact energy absorbing material is foam-molded,
A base part is provided on the base end side of the pin, and the foaming is performed in a state where the entire periphery of the base part is in close contact with the inner peripheral surface of the through hole. Production method.   2. The method for producing an impact energy absorbing material according to claim 1, wherein a middle portion of the pin in a protruding direction is in contact with an inner surface of the through hole.   3. The method for producing an impact energy absorbing material according to claim 2, wherein a protrusion that abuts on a side surface of the pin is provided in an intermediate portion of the inner surface of the through-hole in the axial direction of the through-hole.   4. The method for producing an impact energy absorbing material according to claim 3, wherein the ridge extends in a direction orthogonal to the hole axial direction of the through hole.   5. The method for producing an impact energy absorbing material according to claim 4, wherein the ridges are arranged on both sides of the center of the through hole.   The impact energy according to any one of claims 1 to 5, wherein the clip has a symmetrical shape with a plane passing through the middle of the hole axis direction and perpendicular to the hole axis direction as a symmetry plane. Absorbent manufacturing method.

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