Belt molding and method for producing same

A method for producing a belt molding includes: inserting an insertion portion of an end cap into a molding body such that the insertion portion faces a facing portion of the molding body while the facing portion is positioned on a vehicle interior side relative to the insertion portion; and forming a protruding portion in the molding body. The protruding portion protrudes on a vehicle exterior side relative to a vehicle interior side surface of the insertion portion. The protruding portion is formed by deforming a portion of the facing portion which is closer to the lid portion of the end cap relative to the catch surface.

TECHNICAL FIELD

The present invention relates to a belt molding for a vehicle. In particular, the present invention relates to a type of a belt molding in which an end cap is attached to one end of a long belt molding body. Examples of objects to which such a belt molding is attached include a front door and a rear door of a vehicle.

BACKGROUND ART

Patent Literature 1 relates to a vehicle molding including a long molding body and a molding end cap, and particularly relates to a method for attaching the molding end cap (see paragraphs 0001 and 0002). According toFIGS.9to14and paragraphs 0036 to 0045 of the same literature, in the attaching method, after an ultrasonic horn40is disposed to face a molding body10and a molding end cap20, a cap support portion22of the molding end cap is pressurized toward the molding body10by the ultrasonic horn40subjected to ultrasonic vibration (FIGS.10and11). Then, a part of the molding body10and a part of the cap support portion22melt due to frictional heat of the ultrasonic vibration, and a contact portion43of the ultrasonic horn is pushed into the cap support portion22along a pressure application direction (FIG.12). In association with the pushing of the contact portion43, the melted part of the cap support portion22is embedded in the molding body10in a molten or softened state (an embedded portion22ainFIG.13). Then, with such embedding, ultrasonic welding of the molding end cap20to the molding body10is completed (FIG.14).

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

However, the technique according to Patent Literature 1 also has the following limitations (restrictions) or concern.

First, according to paragraph 0016 in Patent Literature 1, in order to weld the molding end cap to the molding body, the molding body and the molding end cap are preferably formed of different resin materials having relatively close melting points. That is, there is an inevitable limitation (restriction) in selecting materials for the molding body10and the molding end cap20. Second, in Patent Literature 1, a method of applying pressure to the cap support portion22of the molding end cap20by the ultrasonic horn40subjected to ultrasonic vibration is adopted, and thus when the molding end cap is formed of a slightly brittle resin such as polybutylene terephthalate (PBT), the molding end cap may be broken (cracked) by the pressure applied by the ultrasonic horn.

An object of the present invention is to provide a belt molding capable of fixing an end cap to a molding body without excessively limiting a selection of materials for the molding body and the end cap, and a method for producing the belt molding.

Solution to Problem

An invention is characterized by a method for producing a belt molding configured to be attached along an upper edge of a door panel of a vehicle door, the belt molding including a long molding body made of a thermoplastic resin, and an end cap configured to be attached to one end portion of the molding body,the method including:a step of preparing the molding body, the molding body including a vehicle exterior side wall portion and a vehicle interior side wall portion facing each other, and a top wall portion integrally connecting the two side wall portions, the vehicle interior side wall portion including a side wall remaining portion formed by removing a part of the vehicle interior side wall portion in a vicinity of an end of the molding body;a step of preparing the end cap, the end cap including a lid portion configured to close an opening end of the molding body, and an insertion portion extending from the lid portion and configured to be inserted between the vehicle exterior side wall portion of the molding body and the side wall remaining portion, the insertion portion including a vehicle interior side surface extending along an insertion direction of the end cap on a vehicle interior side, the insertion portion on which a catch surface provided to intersect the vehicle interior side surface is formed;an inserting step of inserting the insertion portion of the end cap into the molding body such that the insertion portion of the end cap is disposed to face a part of the molding body while the part of the molding body (hereinafter, referred to as a “facing portion”) is positioned on a vehicle interior side relative to the insertion portion and faces the insertion portion; anda protruding portion forming step of forming a protruding portion in the molding body, the protruding portion protruding on a vehicle exterior side relative to the vehicle interior side surface of the insertion portion of the end cap, by deforming a portion of the facing portion of the molding body, the portion of the facing portion of the molding body being closer to the lid portion of the end cap relative to the catch surface, in whichmovement of the end cap in a direction opposite to the insertion direction can be prevented based on engagement between the protruding portion of the molding body and the catch surface of the end cap.

According to the invention, the protruding portion formed by deforming a part of the facing portion of the molding body is caused to protrude on the vehicle exterior side relative to the vehicle interior side surface of the insertion portion of the end cap, and thus the movement of the end cap in the direction opposite to the insertion direction is prevented based on the engagement (that is, mechanical interference) between the protruding portion and the catch surface of the insertion portion of the end cap, and the end cap can be prevented from falling off from the molding body. In this method, the molding body and the end cap are not welded to each other, and thus the molding body and the end cap do not need to be formed of materials having close melting points, and there is little restriction on a selection of materials (degree of freedom of the selection of materials is high). In the protruding portion forming step, the molding body is deformed and there is no need to deform the end cap, and thus the end cap may not be broken even if the end cap is made of a material which is easy to break.

The invention may be further characterized by the method for producing a belt molding, in whichin the protruding portion forming step, a part of the facing portion of the molding body is melted and deformed to form the protruding portion.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, by employing melting as a deformation method, a part of the facing portion of the molding body can be easily deformed, and the protruding portion can be easily formed.

The invention may be further characterized by the method for producing a belt molding, in whichin the protruding portion forming step, an ultrasonic horn is brought into contact with the facing portion of the molding body to melt the part of the facing portion.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, by using the ultrasonic horn, the part of the facing portion can be heated and melted in a pinpoint manner, and thus the protruding portion can be formed in a limited position or range. By stopping vibration of the ultrasonic horn, the melting of the resin can be immediately stopped (finished in a short time), and the deformation due to the melting can be easily controlled.

The invention may be further characterized by the method for producing a belt molding, in whichthe ultrasonic horn includes a tip projecting portion formed at a tip of the ultrasonic horn and an annular recessed portion formed at an outer peripheral edge of the tip projecting portion.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, when the ultrasonic horn is used, while a portion that is in contact with the tip projecting portion is melted, the excessive molten resin can be received in the annular recessed portion and solidified in the annular recessed portion. Therefore, the excessive molten resin can be prevented from leaking out to the periphery of the protruding portion against an intention, and deterioration in appearance (degradation in appearance) can be prevented.

The invention may be further characterized by the method for producing a belt molding, in whichin the protruding portion forming step, as the part of the facing portion of the molding body is melted, a part of a melted thermoplastic resin enters between the facing portion and the insertion portion around the protruding portion and fills a gap, and then is solidified.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, when the end cap is inserted into the molding body, a slight gap may be inevitably generated between the facing portion of the molding body and the insertion portion of the end cap. In this regard, according to this method, a part of the thermoplastic resin obtained by melting a part of the facing portion for forming the protruding portion enter the gap between the facing portion and the insertion portion around the protruding portion, and is solidified in a state in which the gap is filled. Accordingly, rattling between the molding body and the end cap can be prevented or controlled.

The invention may be further characterized by the method for producing a belt molding, in whichan engaged portion is formed on the side wall remaining portion of the molding body which has been prepared, and an engaging portion configured to engage the engaged portion of the molding body is formed on the insertion portion of the end cap which has been prepared, andin the inserting step, the end cap is temporarily positioned with respect to the molding body based on mutual engagement between the engaging portion and the engaged portion.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, according to this method, in the inserting step, the end cap can be temporarily positioned with respect to the molding body based on the mutual engagement between the engaging portion and the engaged portion, and thus the subsequent protruding portion forming step can be smoothly executed.

The invention may be further characterized by the method for producing a belt molding, in whichafter completion of formation of the protruding portion, the protruding portion and the catch surface are disposed adjacent to each other in a longitudinal direction of the belt molding and are in contact with each other.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, rattling between the molding body and the end cap can be prevented or controlled by mutual contact between the protruding portion of the molding body and the catch surface of the end cap.

The invention may be further characterized by a belt molding configured to be attached along an upper edge of a door panel of a vehicle door, the belt molding including:a long molding body made of a thermoplastic resin; andan end cap configured to be attached to one end portion of the molding body, in whichthe molding body includes a vehicle exterior side wall portion and a vehicle interior side wall portion facing each other, and a top wall portion integrally connecting the two side wall portions, the vehicle interior side wall portion including a side wall remaining portion formed by removing a part of the vehicle interior side wall portion in a vicinity of an end of the molding body,the end cap includes a lid portion configured to close an opening end of the molding body, and an insertion portion extending from the lid portion and configured to be inserted between the vehicle exterior side wall portion of the molding body and the side wall remaining portion,the insertion portion of the end cap includes a vehicle interior side surface extending along an insertion direction of the end cap on a vehicle interior side, the insertion portion on which a catch surface provided to intersect the vehicle interior side surface is formed,the molding body includes a facing portion, the facing portion being positioned on the vehicle interior side relative to the insertion portion of the end cap and facing the insertion portion when the end cap is attached to the molding body, anda portion of the facing portion of the molding body, the portion of the facing portion of the molding body being closer to the lid portion of the end cap relative to the catch surface, is formed with a protruding portion formed by deforming a part of the facing portion, and the protruding portion protrudes on a vehicle exterior side relative to the vehicle interior side surface of the insertion portion of the end cap such that movement of the end cap in a direction opposite to the insertion direction can be prevented based on engagement with the catch surface.

According to the invention, the protruding portion formed by deforming a part of the facing portion of the molding body is caused to protrude on the vehicle exterior side relative to the vehicle interior side surface of the insertion portion of the end cap, and thus the movement of the end cap in the direction opposite to the insertion direction is prevented based on the engagement (that is, mechanical interference) between the protruding portion and the catch surface of the insertion portion of the end cap, and the end cap can be prevented from falling off from the molding body. In this configuration, the molding body and the end cap are not welded to each other, and thus the molding body and the end cap do not need to be formed of materials having close melting points, and there is little restriction on the selection of materials (degree of freedom of the selection of materials is high).

The invention may be further characterized by the belt molding, in whichwhen the end cap is attached to the molding body, the protruding portion and the catch surface are disposed adjacent to each other in a longitudinal direction of the belt molding and are in contact with each other.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, according to this configuration, rattling between the molding body and the end cap can be prevented or controlled by mutual contact between the protruding portion of the molding body and the catch surface of the end cap.

The invention may be further characterized by the belt molding, in whichthe protruding portion is formed by melting and deforming a part of the facing portion, anda thermoplastic resin obtained by melting a part of the facing portion enters between the facing portion and the insertion portion around the protruding portion and fills a gap.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, when the end cap is attached to the molding body, a slight gap may be inevitably generated between the facing portion of the molding body and the insertion portion of the end cap. In this regard, according to this configuration, a part of the thermoplastic resin obtained by melting a part of the facing portion for forming the protruding portion enters the gap between the facing portion and the insertion portion around the protruding portion, and fills the gap. Accordingly, rattling between the molding body and the end cap can be prevented or controlled.

The invention may be further characterized by the belt molding, in whichthe facing portion is formed by the side wall remaining portion of the vehicle interior side wall portion, and the protruding portion is formed on the side wall remaining portion.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, in this configuration, the facing portion where the protruding portion is to be formed is set in (the side wall remaining portion of) the vehicle interior side wall portion, and thus an area of the facing portion usable for forming the protruding portion (that is, the extent of the facing portion serving as a deformation target) can be secured to be relatively large. Therefore, a volume of the protruding portion obtained by the deformation of the facing portion can be secured to a necessary extent, and the end cap can be stably fixed to the molding body by the protruding portion.

The invention may be further characterized by the belt molding, in whichthe protruding portion is formed at two or more positions.

In addition to the effect of the invention discussed earlier, the following effect is further exhibited. That is, according to this configuration, the end cap can be more firmly fixed to the molding body by a plurality of protruding portions.

Advantageous Effects of Invention

As described above in detail, according to the belt molding and the producing method thereof of the present invention, the end cap can be fixed to the molding body without excessively limiting the selection of the materials for the molding body and the end cap.

DESCRIPTION OF EMBODIMENTS

Hereinafter, several embodiments of the present invention will be described with reference to the drawings.

FIG.1illustrates a typical use example of a belt molding according to the present invention. As illustrated inFIG.1, a belt molding3is attached to an outer-side door panel2constituting a lower half portion of a vehicle door1along an upper edge (a belt line) of the door panel2. The belt molding3includes a main body portion (hereinafter, referred to as a “molding body”)10of the long belt molding, and an end cap30attached to a rear end portion (a right end portion inFIG.1) of the molding body10.

As illustrated inFIG.2, the molding body10includes a vehicle exterior side wall portion11and a vehicle interior side wall portion12facing each other, and a top wall portion13integrally connecting the two side wall portions11and12. With the three wall portions (11to13), the molding body10has a substantially U-shaped cross section opening downward. A folded elongated protrusion14formed so as to be folded back toward a vehicle interior side is provided at a lower end of the vehicle exterior side wall portion11. A vehicle interior side lip15ais provided on a vehicle interior side wall surface of the vehicle interior side wall portion12, a vehicle exterior side lip15bis provided in the vicinity of the lower end of the vehicle exterior side wall portion11, a holding lip15cis provided at a tip of the folded elongated protrusion14at the lower end of the vehicle exterior side wall portion, and a decorative lip15dis provided in the vicinity of a joint portion between the top wall portion13and the vehicle interior side wall portion12. However, these lips15ato15dare generally known. When a flange2f(indicated by an imaginary line) of the door panel2is inserted into a lower opening of the belt molding3, the flange2fis sandwiched between the holding lip15cand the vehicle interior side wall portion12, and the belt molding3is attached to the door panel2.

The molding body10is preferably formed by extruding an olefin-based thermoplastic resin material. However, a relatively hard olefin-based thermoplastic resin (for example, polypropylene) is used for the three wall portions (11to13) and the elongated protrusion (14) of the molding body10. On the other hand, a relatively soft olefin-based thermoplastic elastomer is used for the four lips (15ato15d) other than the three wall portions and the elongated protrusion. The molding body10may be made of a material other than the olefin-based thermoplastic resin (for example, a styrene-based thermoplastic resin, vinyl chloride, rubber, or the like) as long as the material is meltable and elastically deformable.

The end cap30is preferably formed of polybutylene terephthalate (PBT) which is a kind of a thermoplastic resin. Examples of the thermoplastic resin that can be used for the end cap30include acrylonitrile butadiene styrene (ABS) resin, polypropylene (PP), polyacetal (POM), polyamide (PA), polyphenylene sulfide (PPS), and polyether ether ketone (PEEK), in addition to PBT.

The description so far is made to describe matters common to embodiments to be described below.

First Embodiment

FIGS.3to6illustrate a belt molding according to a first embodiment of the present invention. In particular,FIG.4is a diagram illustrating a state in which the molding body10and the end cap30are disassembled. As illustrated inFIG.4, in the vicinity of the rear end portion of the molding body10, mainly a lower side portion of the vehicle interior side wall portion12is removed, and an upper side portion of the vehicle interior side wall portion12remains (hereinafter, this remaining portion is referred to as a “side wall remaining portion16”). The side wall remaining portion16does not include the vehicle interior side lip15a, and along with the formation of the side wall remaining portion16, a portion of the holding lip15cof the vehicle exterior side wall portion11that faces the side wall remaining portion16is also substantially cut off while leaving only a root portion. An internal space for inserting and disposing an insertion portion32of the end cap30is defined by the three wall portions (the vehicle exterior side wall portion11, the top wall portion13, and the side wall remaining portion16) positioned in the vicinity of the rear end portion of the molding body10.

As illustrated inFIG.3andFIG.4, an extension portion17is formed at an end of the molding body10by a part of the side wall remaining portion16. The extension portion17is a side wall portion that extends downward from an upper edge of the vehicle interior side wall portion12and forms a portion of the side wall remaining portion16. When the end cap30is attached to the molding body10, the extension portion17is elastically deformable to some extent toward the vehicle interior side. The extension portion17includes a front side edge17aand a rear side edge17b, and an engaged portion18extending in a direction intersecting an insertion direction of the end cap is formed on the front side edge17a. The rear side edge17bof the extension portion17forms the rear end (an opening end) of the molding body10.

As illustrated inFIG.3andFIG.4, the end cap30includes a lid portion31and an insertion portion32extending substantially horizontally from a front surface of the lid portion31along a longitudinal direction (that is, the insertion direction) of the end cap. The lid portion31is a portion for closing the rear end (the opening end) of the molding body10, and constitutes a rearmost end portion of the end cap30. The insertion portion32is a portion that is to be inserted and disposed between the vehicle exterior side wall portion11and the side wall remaining portion16of the molding body10. The insertion portion32includes a vehicle interior side surface32aextending along the insertion direction of the end cap on the vehicle interior side.

The insertion portion32of the end cap is provided with a thick plate tab-shaped support portion (hereinafter, referred to as a “support tab”)33formed to extend downward from an upper edge of the insertion portion32. The support tab33is a part of the insertion portion32of the end cap. The support tab33has a substantially rectangular shape in a side view, and an engaging portion34protruding from a vehicle interior side surface33aof the support tab33toward the vehicle interior side is provided at a position close to the front of the support tab33. When the end cap30is inserted into the molding body10, the engaging portion34functions as means for temporarily positioning (or temporarily fixing) the end cap30with respect to the molding body10based on mutual engagement with the engaged portion18of the extension portion17. As illustrated inFIG.4, an inclined surface35is formed at a front side position of the engaging portion34of the support tab33. When the end cap30is inserted into the molding body10, the inclined surface35functions as a pressing and guiding surface for pressing the extension portion17of the molding body toward the vehicle interior side to guide temporary elastic deformation.

Further, the end cap30according to the first embodiment includes a catch portion37formed on an upper side portion of the insertion portion32at a position in front of the support tab33. The catch portion37is a recessed portion cut out in a substantially semicircular shape in a side view illustrated inFIG.4, and the semicircular shape corresponds to an outer shape of a tip of an ultrasonic horn40to be described later (a circular shape). In consideration of assembly tolerance and the like, it is ordinary in design to set a radius of the semicircular shape of the catch portion37to be slightly larger than a radius of the circular shape of the ultrasonic horn, whereas in the present invention, it is preferable that the radii of both are substantially the same. The catch portion37includes a curved catch surface37a(seeFIGS.4and6) on an inner side of the recessed shape, the catch surface37aextending in vehicle interior and exterior directions (a width direction of the end cap). The catch surface37ais in a positional relation of intersecting with the vehicle interior side surface32aof the insertion portion32of the end cap, and acts to prevent movement of the end cap (that is, movement in a direction opposite to the insertion direction of the end cap) based on engagement with a protruding portion21to be described later.

InFIG.4andFIG.6, the catch portion37is illustrated as a recessed portion that penetrates the insertion portion32in the vehicle interior and exterior directions (the width direction of the end cap), but the catch portion37serving as a recessed portion does not need to penetrate the insertion portion32, and may be a non-penetrating recessed portion in which the vehicle interior side surface32aof the insertion portion32is merely recessed toward a vehicle exterior side. In short, a form (penetrating/non-penetrating) of the catch portion37is not limited as long as the catch surface37aas described above can be provided.

Next, a method for attaching and fixing the end cap30to the molding body10(that is, a method for assembling the belt molding) will be described. After preparing the molding body10and the end cap30described above in advance, the method generally includes an inserting step of inserting and disposing the end cap30in the molding body10, and a protruding portion forming step of fixing the end cap30to the molding body10by forming the protruding portion21to be described later in the molding body10.

In the inserting step, the insertion portion32of the end cap30is inserted into the molding body from the opening end of the molding body10. Then, first, the inclined surface35positioned on the front side of the engaging portion34of the end cap comes into contact with the rear side edge17bof the extension portion17of the molding body. As the end cap30is further pushed in after the contact, the rear side edge17bof the extension portion slides while contacting the inclined surface35, and the extension portion17is progressively elastically deformed toward the vehicle interior side due to the pressing and guiding action of the inclined surface35. Thereafter, when the end cap30is further pushed in and the engaging portion34of the end cap passes through (a position of) the extension portion17, the sliding contact between the extension portion17and the engaging portion34is released, and the extension portion17that is temporarily elastically deformed returns to an original position or shape before the deformation. The lid portion31of the end cap comes into contact with the opening end of the molding body10substantially in synchronization with the return of the extension portion17from the elastically deformed state. Due to this contact, the end cap30cannot move further forward, and the insertion of the end cap30into the molding body10is completed (seeFIG.3andFIG.4).

In an insertion completion state, as illustrated inFIG.3, the engaging portion34of the end cap30is disposed in front of the engaged portion18of the extension portion17of the molding body. Therefore, even if an external force in a pull-out direction (that is, the direction opposite to the insertion direction of the end cap) acts on the end cap30, the engaging portion34is caught by the engaged portion18, and the end cap30does not come off from the molding body10. In this manner, the end cap30is temporarily positioned with respect to the molding body10based on the mutual engagement between the engaging portion34and the engaged portion18. This is a prerequisite or preparation for smoothly executing the subsequent protruding portion forming step.

In the insertion completion state, as illustrated in (A) ofFIG.5and (A) ofFIG.6, the upper side portion of the insertion portion32of the end cap30(in particular, in the vicinity of the catch portion37) and the side wall remaining portion16of the molding body10are disposed to face each other. That is, in the present embodiment, the side wall remaining portion16serves as a “facing portion that is positioned on the vehicle interior side relative to the insertion portion (0.32) of the end cap and that faces the insertion portion (32)”. As can be seen from (A) ofFIG.6, as a result of the insertion portion32and the side wall remaining portion16serving as the facing portion facing each other substantially in parallel, a gap S is inevitably formed between the both.

In the protruding portion forming step subsequent to the inserting step, by deforming (melting and deforming) a portion of the side wall remaining portion16serving as the facing portion, which is closer to the lid portion31relative to the catch surface37aof the end cap, the protruding portion21protruding on the vehicle exterior side relative to the vehicle interior side surface32aof the insertion portion32of the end cap is formed in the molding body10. In the protruding portion forming step, the ultrasonic horn40as partially and schematically illustrated in (A) ofFIG.5is used as melting deformation means. The ultrasonic horn40used in the present embodiment includes a tip projecting portion41having a circular cross section and an annular ridge42surrounding the tip projecting portion41at the tip of the ultrasonic horn40. An annular recessed portion43is formed along an outer peripheral edge of the tip projecting portion41between the tip projecting portion41and the annular protrusion42. The annular recessed portion43receives an excess of a resin melted by the tip projecting portion41and prevents an unintended spread of the molten resin.

(A) and (B) ofFIG.5and (A) and (B) ofFIG.6illustrate a specific procedure of the protruding portion forming step in which the ultrasonic horn40is used. When forming the protruding portion, the ultrasonic horn40is disposed on the vehicle interior side of the molding body10, and a rear side surface of the lid portion31of the end cap30is brought into contact with a jig (not-illustrated) to position the end cap30and the molding body10.

Then, as illustrated in (A) ofFIG.5and (A) ofFIG.6, the ultrasonic horn40is disposed to face the side wall remaining portion16and the insertion portion32such that the tip projecting portion41of the ultrasonic horn40faces (directly faces) the catch portion37of the end cap with the side wall remaining portion16of the molding body interposed therebetween. After the tip projecting portion41of the ultrasonic horn40is pressed against the side wall remaining portion16at a substantially right angle, the ultrasonic horn40is subjected to ultrasonic vibration and slowly advanced toward the catch portion37. Along with the contact, pressing, and advancing of the ultrasonic horn40, a part of the side wall remaining portion16is heated and melted in a pinpoint manner, and the melted resin enters the catch portion37while being pressed by the tip projecting portion41of the ultrasonic horn, whereby the protruding portion21is formed (see (B) ofFIG.5, andFIG.6). Thereafter, the ultrasonic horn40is separated from the side wall remaining portion16, whereby the molten or softened protruding portion21is solidified in the catch portion37by natural cooling, and the solid protruding portion21is completed. On a back side (a base end side) of the protruding portion21, complementary shapes (that is, a central recessed portion22, an annular projecting portion23, and an annular groove24) are formed as traces reflecting the tip projecting portion41, the annular recessed portion43, and the annular protrusion42of the ultrasonic horn40.

As illustrated in (B) ofFIG.5and (A) ofFIG.6, the completed protruding portion21is disposed in the catch portion37of the end cap, and is disposed adjacent to the catch surface37ain the longitudinal direction of the belt molding and is in contact with the catch surface37a. The molding body10and the end cap30are fixed to each other by mutual contact between the protruding portion21of the molding body and the catch surface37aof the end cap, and rattling between the molding body10and the end cap30is prevented or controlled.

As a part of the side wall remaining portion16is melted by the ultrasonic horn40in the process of forming the protruding portion, as illustrated in an enlarged view illustrated in (B) ofFIG.6, a small part of the melted thermoplastic resin (19) leaks out to the periphery of the protruding portion21, enters the gap S between the insertion portion32and the side wall remaining portion16, and fills the gap S. However, the gap S is very narrow, and thus the molten resin19does not flow out of the gap S immediately, and can be appropriately retained in the gap S due to a surface tension or the like of the molten resin. The resin layer19, which fills the gap S, is solidified in an integrated state with the protruding portion21over time, and the resin layer19solidified in the gap S serves as an aid for preventing or controlling rattling between the molding body10and the end cap30.

Effects of First Embodiment

According to the first embodiment, the protruding portion21formed by melting and deforming a part of the side wall remaining portion16serving as the facing portion is caused to protrude on the vehicle exterior side relative to the vehicle interior side surface32aof the insertion portion32of the end cap, and thus the movement of the end cap30in the direction opposite to the insertion direction is restricted based on the engagement (that is, mechanical interference) between the protruding portion21and the catch surface37aof the insertion portion32of the end cap. Therefore, the end cap30can be prevented from falling off from the molding body10.

In the method according to the first embodiment, the molding body10and the end cap30are not welded to each other, and thus the molding body10and the end cap30do not need to be formed of materials having close melting points, and there is little restriction on a selection of materials. In the protruding portion forming step, the molding body10is melted and deformed and there is no need to deform the end cap30, and thus the end cap30may not be broken even if the end cap30is made of a material which is easy to break (for example, a PBT resin).

According to the first embodiment, the ultrasonic horn40is used, and thus a part of the side wall remaining portion16serving as the facing portion can be heated and melted in a pinpoint manner by the tip projecting portion41which is ultrasonically vibrated. On the other hand, by stopping the ultrasonic vibration, the melting of the resin can be stopped immediately (or in an extremely short time). Therefore, the deformation due to melting can be easily controlled, and the protruding portion21can be appropriately formed in a limited position or range.

By using the ultrasonic horn40as illustrated in (A) ofFIG.5, while the resin portion in contact with the tip projecting portion41is melted, the excessive molten resin can be processed as the annular projecting portion23appearing on the base end side of the protruding portion21by receiving the excessive molten resin into the annular recessed portion43and solidifying in the annular recessed portion. Therefore, the excessive molten resin can be prevented from leaking out to the periphery of the protruding portion21against an intention, and deterioration in appearance (degradation in appearance) can be prevented.

In the first embodiment, the catch portion37is set on the upper side portion of the insertion portion32of the end cap, and in response to this, the protruding portion21is formed at a position facing the catch portion37in the side wall remaining portion16of the molding body (seeFIG.3). By forming the protruding portion21at such a position, the protruding portion21is less likely to come into contact with the door panel2, which is very preferable in design. The facing portion where the protruding portion21is to be formed is set in the side wall remaining portion16, and thus an area of the facing portion usable for forming the protruding portion can be secured to be relatively large. Therefore, a volume of the protruding portion21obtained by the melting deformation of the facing portion (the side wall remaining portion16) can be secured to a necessary extent, and the end cap30can be stably fixed to the molding body10by the protruding portion21.

Second Embodiment

FIG.7andFIG.8illustrate an outline of a belt molding according to a second embodiment of the present invention. Hereinafter, in order to avoid redundant description, differences front the first embodiment will be mainly described.

As illustrated in (A) and (B) ofFIG.7, in the second embodiment, unlike the first embodiment, the catch portion37is provided on a rear end side of the support tab33of the end cap30. Specifically, in a side view illustrated in (B) ofFIG.7, an edge portion on the rear end side of the support tab33is illustrated as an edge portion extending straight in a vertical direction, and an upper portion of the edge portion extending straight in the vertical direction is set as the “catch portion37”. The straight catch portion37includes the planar catch surface37athat extends in a depth direction (that is, vehicle interior and exterior directions or a width direction of the end cap) in the side view. The catch surface37ais in a positional relation of intersecting the vehicle interior side surface33aof the support tab33. In the second embodiment, as illustrated in (A) ofFIG.7, the protruding portion21is formed on the extension portion17, which is a pan of the side wall remaining portion16of the molding body, corresponding to the catch portion37set on the rear end side of the support tab33. The “molding body10before the protruding portion is formed” used in the second embodiment is substantially the same as the molding body10before the protruding portion is formed in the first embodiment.

(A) and (B) ofFIG.8illustrate an outline of a protruding portion forming process in the second embodiment.

An inserting step of inserting the end cap30illustrated in (B) ofFIG.7into the molding body10(before the protruding portion is formed) is substantially the same as the inserting step in the first embodiment. However, in an insertion completion state, as illustrated in (A) ofFIG.8, the support tab33(that is, a part of the insertion portion32) of the end cap30, in particular, in the vicinity of the catch portion37of the support tab33, and the extension portion17(that is, a part of the side wall remaining portion16) of the molding body are disposed to face each other. That is, in the present embodiment, the extension portion17, which is a part of the side wall remaining portion16, serves as a “facing portion that is positioned on a vehicle interior side relative to the insertion portion (the support tab33) of the end cap and that faces the insertion portion (33)”.

In a protruding portion forming step subsequent to the inserting step, by melting and deforming a portion of the extension portion17serving as the facing portion, which is closer to the lid portion31relative to the catch surface37aof the end cap, by the ultrasonic horn40, the protruding portion21protruding on a vehicle exterior side relative to the vehicle interior side surface33aof the support tab33(that is, a vehicle interior side surface of the insertion portion) of the end cap is formed in the molding body10. As illustrated in (B) ofFIG.8, the completed protruding portion21is disposed adjacent to the catch portion37of the end cap, and is disposed adjacent to the catch surface37ain a longitudinal direction of the belt molding and is in contact with the catch surface37a. Accordingly, the end cap30is restricted from moving backward (falling off).

A technical significance of the protruding portion21in the second embodiment is basically the same as that of the protruding portion21in the first embodiment. The belt molding according to the second embodiment has the same functions and effects as those of the first embodiment.

Third Embodiment

FIG.9andFIG.10illustrate an outline of a belt molding according to a third embodiment of the present invention. Hereinafter, in order to avoid redundant description, differences from the first embodiment will be mainly described.

As illustrated in (A) and (B) ofFIG.9, in the third embodiment, unlike the first embodiment, the catch portion37is formed on a lower side portion of the insertion portion32of the end cap30. The catch portion37is a recessed portion cut out in a substantially semicircular shape in a side view illustrated in (B) ofFIG.9, and the semicircular shape corresponds to an outer shape of a tip of an ultrasonic horn. The catch portion37includes the curved catch surface37aon an inner side of the recessed shape, the catch surface37aextending in vehicle interior and exterior directions (a width direction of the end cap). The catch surface37ais in a positional relation of intersecting the vehicle interior side surface32aof the insertion portion32of the end cap. In the third embodiment, as illustrated in (A) ofFIG.9andFIG.10, the protruding portion21is formed by using the folded elongated protrusion14and the holding lip15c(a remaining root portion) of a molding body in correspondence with the catch portion37provided on the lower side portion of the insertion portion32of the end cap. The “molding body10before the protruding portion is formed” used in the third embodiment is substantially the same as the molding body10before the protruding portion is formed in the first embodiment.

FIG.10generally suggests a protruding portion forming process in the third embodiment.

An inserting step of inserting the end cap30illustrated in (B) ofFIG.9into the molding body10(before the protruding portion is formed) is substantially the same as the inserting step in the first embodiment. However, in an insertion completion state, as suggested in (A) ofFIG.9andFIG.10, the lower side portion (in particular, in the vicinity of the catch portion37) of the insertion portion32of the end cap30and the folded elongated protrusion14and the holding lip15c(the remaining root portion) of the molding body10are disposed to face each other. That is, in the present embodiment, the folded elongated protrusion14and the holding lip15c(the remaining root portion) continuous with the folded elongated protrusion14are integrated with each other and serve as a “facing portion that is positioned on a vehicle interior side relative to the insertion portion (32) of the end cap and that faces the insertion portion (32)” (seeFIG.10and (A) ofFIG.5together if necessary).

In a protruding portion forming step subsequent to the inserting step, by melting and deforming a portion of the folded elongated protrusion14and the holding lip15c(the remaining root portion) serving as the facing portion, which is closer to the lid portion31relative to the catch surface37aof the end cap, by the ultrasonic horn40, the protruding portion21protruding on a vehicle exterior side relative to the vehicle interior side surface32aof the insertion portion32of the end cap is formed in the molding body10(seeFIG.10). As illustrated in (A) ofFIG.9andFIG.10, the completed protruding portion21is disposed in the catch portion37of the end cap, and is disposed adjacent to the catch surface37ain the longitudinal direction of the belt molding and is in contact with the catch surface37a. Accordingly, the end cap30is restricted from moving backward (falling off).

A technical significance of the protruding portion21in the third embodiment is basically the same as that of the protruding portion21in the first embodiment. The belt molding according to the third embodiment has the same functions and effects as those of the first embodiment.

Modification and Preferred Embodiments

The present invention is not limited to the first to third embodiments, and may be implemented in the following manner.

In each of the above embodiments, only one protruding portion21is provided for one belt molding, but two or more protruding portions21may be formed for one belt molding. By forming a plurality of protruding portions21, the end cap30is less likely to come off from the molding body10, and the end cap30can be more firmly fixed to the molding body10. In this case, it is preferable to use an ultrasonic melting jig50in which two ultrasonic horns40are arranged side by side as illustrated inFIG.11. Work time can be reduced by using the jig50.

It is preferable that an outer diameter D of the ultrasonic horn40(seeFIGS.5and11) is not out of a range of the facing portion. For example, inFIG.5, the outer diameter D of the ultrasonic horn40is preferably smaller than a height h of the side wall remaining portion16serving as the facing portion by 1.0 mm or more. By setting dimensions in this manner, the resin obtained by melting a part of the facing portion can be caused to enter the annular recessed portion43of the ultrasonic horn40and can be solidified without overflowing to the periphery.

In the above embodiments, the ultrasonic horn40is used, but instead of the ultrasonic horn40, a thermocouple may be used to form the protruding portion21.

In the above embodiments, the protruding portion is formed by melting and deforming a part of the facing portion, but the protruding portion may be formed by giving an external force to a part of the facing portion.

REFERENCE SIGNS LIST

1: vehicle door2: door panel3: belt molding10: molding body11: vehicle exterior side wall portion12: vehicle interior side wall portion13: top wall portion14: folded elongated protrusion (“facing portion” in third embodiment)16: side wall remaining portion (“facing portion” in first embodiment)17: extension portion (“facing portion” in second embodiment)18: engaged portion19: resin layer (derived from molten thermoplastic resin)21: protruding portion30: end cap31: lid portion32: insertion portion32a: vehicle interior side surface of insertion portion33: support tab (a part of insertion portion)33a: vehicle interior side surface of support tab (also vehicle interior side surface of insertion portion)34: engaging portion37: catch portion37a: catch surface40: ultrasonic horn41: tip projecting portion42: annular protrusion43: annular recessed portionS: gap