JP2009035142A - Upper and lower combined plastic housing and manufacturing method for upper and lower combined plastic housing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shroud with excellent toughness, capable of being tightly connected between the upper and the lower without any mechanical connecting portion such as screwing. <P>SOLUTION: This shroud includes: an upper shroud 110 extending along the side of a fuel tank to be covered with: and a lower shroud 120 for covering the side of a radiator. First, the lower shroud 120 is molded with synthetic resin and mounted with a through hole 121 for penetrating from the front side to the back side by taking around the upper side of the lower shroud 120 as a connecting portion. The molding is performed so that the area of the front side of the through hole 121 is larger than the area of the back side. Next, the upper shroud 110 is molded so that the upper shroud 110 covers the lower shroud 120 on the connecting portion 130 from the above. The synthetic resin in the upper shroud enters into the through hole 121 of the lower shroud, thereby molding an anchor 111. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plastic casing of a motorcycle. In particular, the present invention relates to a plastic casing of an off-road motorcycle. Examples of the plastic casing of the motorcycle include a shroud, a side cover, and a bib plate.

In motorcycles, particularly off-road motorcycles, a plastic casing cover such as a shroud molded from a synthetic resin is attached for weight reduction or design. In addition, the shroud is attached so that it may cover from the outer surface as a housing | casing which protects the side surface of a fuel tank, and the side surface of the radiator arrange | positioned under it (refer patent document 1).
In recent motorcycles, the design has been regarded as important, and plastic casing covers including shrouds are becoming increasingly complex and colored, such as so-called two-tone designs.

  The following methods are known as methods for creating a two-tone design in a housing cover including a shroud.

The first method is a sticker application method. In other words, after the entire shroud is integrally molded with a synthetic resin, the color is changed to a two-tone color by partially sticking a sticker.
However, the method of sticking a sticker on an integrally molded synthetic resin plate has a problem that it is difficult to cope with a design change or a design change.

The second method is a painting method. In other words, after the entire shroud is integrally molded with a synthetic resin, it is colored by painting to give a two-tone color.
However, in the method of coloring by painting, color unevenness is likely to occur. In addition, the shroud is a part where a rider's boots or the like hits, and there is a problem that the paint is easy to peel off.

  A third method is a screwing method of a plurality of cases. In other words, this is a method in which the shroud is divided into a plurality of parts for each color, each is formed of a synthetic resin, and these are mechanically connected by screwing or the like.

FIGS. 16 and 17 are configuration examples of a screw-integrated shroud manufactured by a conventional multi-case screwing method. FIG. 16 is a surface view of a screw-integrated shroud, and FIG. 17 is a cross-sectional view thereof. As shown in FIGS. 16 and 17, the shroud 200 includes an upper shroud 210 and a lower shroud 220, each of which is separately molded by a separate mold. The lower end portion of the upper shroud 210 and the upper end portion of the lower shroud 220 are overlapped, and female screw structures 215 and 225 are provided on the back surfaces of the overlapping portions, respectively, and are screwed together by screws 230. The shroud 220 is united.
With this method, it is said that there is no problem that color unevenness or the like does not occur as in the conventional coating method, and the color peels off (Patent Document 2).

Japanese Patent Laid-Open No. 05-85440 JP 2006-282050 A

  According to the above-mentioned screwing method of multiple housings, the shroud is divided into a plurality of parts for each color and each is molded with synthetic resin, so the color coding is beautiful and the two-tone design can be realized beautifully. . For example, in the case of an upper and lower two-tone color, if two upper and lower shroud parts are separately molded and then overlapped and screwed, a two-color beautiful two-color shroud can be manufactured.

  However, according to the above-mentioned screwing method for multiple housings, compared to the conventional procedure for integrally molding the entire shroud with synthetic resin, the procedure for molding the shroud parts for each of the upper and lower two colors with synthetic resin, A procedure for superimposing two shroud parts and a procedure for screwing the shroud parts on the back surfaces of both are necessary, resulting in an increase in the number of processes. Although it depends on the shape and design of the shroud, there are problems that the number of screwing points increases to 5 to 6 and the number of steps to increase increases. Furthermore, in order to secure the structural strength and the margin to be screwed, a certain width is required in the region where the upper and lower shroud parts are overlapped. Most conventional examples have a thickness of 30 mm or more.

  In addition, even if the design is brought into the shroud and the complex shape and color are made of synthetic resin, as long as the original purpose of the shroud is the protective cover for the fuel tank and radiator, it is difficult to break and deforms due to external force. Sufficient structural strength is required, such as providing toughness to absorb by Therefore, in the case of a synthetic resin, it is preferable to perform integral molding.

  However, according to the above-mentioned screwing method of a plurality of housings, there is a problem that the screwing portion is easily broken or cannot be bent and the toughness is poor.

  In view of the above problems, the present invention provides a shroud having excellent toughness in which the shroud is made of synthetic resin for each color and is firmly joined to each other without a mechanical joint portion such as screwing. For the purpose.

In order to achieve the above object, the upper and lower combined shrouds of the present invention are:
A motorcycle plastic casing, comprising two plastic casings, an upper plastic casing and a lower plastic casing,
First, the lower plastic casing is molded from a synthetic resin, and a through hole that penetrates from the front surface to the rear surface with the vicinity of the upper side of the lower plastic casing as a joint portion is provided. Molded to be larger,
The upper plastic casing is molded later with a synthetic resin at a position above the lower plastic casing, and the upper plastic casing is formed so as to cover the lower plastic casing from above at the joint portion. The synthetic resin of the upper plastic casing enters into the through hole of the lower plastic casing and serves as an anchor.

  With the above configuration, by molding the lower plastic casing first and then forming the upper plastic casing on top of it, it can be molded with the upper and lower combined mold, and the work process is dramatically faster than the conventional process such as screwing. Can be shortened. In addition, when forming the upper plastic casing, so-called anchors that do not come out are formed using the through holes of the lower plastic casing, making it difficult to separate them and increasing the structural strength. In addition, since it is firmly joined by a large number of small anchor structures instead of mechanical joining such as screwing, the width of overlapping the upper and lower plastic casings may be small, 20 mm or less, for example, about 7 mm. It is also possible.

  Next, in the above configuration, the upper end of the joint portion of the lower plastic casing has a key claw structure, and the lower end of the joint portion of the upper plastic casing is fitted to the return structure of the upper end of the lower plastic casing. It has a key claw structure, and the lower end of the upper plastic casing and the lower end of the upper plastic casing are turned back while the lower end of the upper plastic casing joins the upper end of the lower plastic casing. It is preferable to fit the structure together so that they are combined.

  With the above-described configuration, the lower plastic joint can be engaged with the key-like return structure while the lower end of the joining portion of the lower plastic housing is wrapped around the upper end of the lower plastic housing. In addition, both are less likely to come off.

  Next, in the above-described configuration, in the mold for molding the upper plastic casing, along the portion that becomes the lower end of the upper plastic casing slightly below the through hole of the joining portion on the surface side of the lower plastic casing In this way, the mold wall is provided so that the synthetic resin injected into the upper plastic casing through the mold wall does not flow downward, and the boundary between the upper plastic casing and the lower plastic casing is clarified. It is characterized by that.

  With the above configuration, the boundary between the lower plastic casing and the upper plastic casing can be clearly expressed even when the upper plastic casing is overlaid on the previously molded lower plastic casing. Color coding such as color can also be expressed beautifully.

Next, in the above configuration, a partition wall for increasing the structural strength is provided on the back surface of each of the upper plastic housing and the lower plastic housing, and the partition running on the back surface of the upper plastic housing at the joint portion. A wall and the partition wall running on the back surface of the lower plastic casing are joined, and an upper end of the partition wall of the lower plastic casing is enlarged at the joined portion, and the partition wall of the upper plastic casing is The lower end of the lower plastic casing is formed to cover the upper end of the partition wall, and the upper end of the lower plastic casing is an anchor to the partition wall of the upper plastic casing. It is characterized by.
It is also possible to reverse the anchor structure of the upper and lower partition walls. That is, the lower end of the partition wall of the upper plastic casing is large at the joint portion, and the upper end of the partition wall of the lower plastic casing includes the lower end of the partition wall of the upper plastic casing. A lower end of the partition wall of the upper plastic casing serves as an anchor with respect to the partition wall of the lower plastic casing.

  In the case of a plate-shaped plastic casing molded with synthetic resin, etc., there is a contrivance to provide a partition wall on the back surface in order to increase the strength against bending of the plate surface. Can also be used. An anchor is formed in such a manner that one is embedded in the other at the joining portion of the partition wall straddling the upper plastic casing and the lower plastic casing, thereby increasing the structural strength.

  The plastic housing includes a motorcycle shroud, a side cover, a bib plate, and the like.

Next, the manufacturing method of the upper and lower combined type shroud of the present invention is as follows.
A method of manufacturing a plastic casing for a motorcycle, comprising: a plastic casing for a motorcycle, comprising two upper and lower plastic casings; an upper plastic casing and a lower plastic casing;
The lower plastic casing is first molded from a synthetic resin, and a through hole is provided that penetrates from the front surface to the rear surface with the vicinity of the upper side of the lower plastic casing as a joint portion. Molded to be larger,
The upper plastic casing is molded later with a synthetic resin at a position above the lower plastic casing, and the upper plastic casing is formed so as to cover the lower plastic casing from above at the joint portion. And a method of manufacturing a plastic casing of an upper and lower unit type in which the synthetic resin of the upper plastic casing enters into the through hole of the lower plastic casing to form an anchor.

According to the upper and lower united plastic casing according to the present invention, by forming the lower plastic casing first and then forming the upper plastic casing from above, the upper and lower united mold can be molded. Compared to work processes such as screwing, the work process can be dramatically shortened. In addition, when forming the upper plastic casing, so-called anchors that do not come out are formed using the through holes of the lower plastic casing, making it difficult to separate them and increasing the structural strength.
Further, according to the upper and lower united plastic casing according to the present invention, the lower plastic casing and the upper plastic casing can be formed even when the upper plastic casing is overlapped with the lower plastic casing previously molded. The boundaries of the housing can be clearly expressed, and color coding such as two-tone colors can be clearly expressed.
Further, according to the upper and lower united plastic casing according to the present invention, the anchor is formed in such a manner that one is embedded in the other at the joining portion of the partition wall straddling the upper plastic casing and the lower plastic casing, Strength can be increased.

  Hereinafter, the upper and lower united plastic casing of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings. The present invention is not limited to these examples.

  Hereinafter, an example of a shroud of an off-road motorcycle will be described as an example of an upper and lower united plastic casing according to the present invention with reference to the drawings. In addition to the shrouds of off-road motorcycles, the side cover of off-road motorcycles, the number plate of off-road motorcycles (for rider windbreaks and racing) The part to which the bib number is attached).

  FIG. 1 is a diagram showing a motorcycle 10 according to an embodiment of the present invention. The motorcycle 10 is a typical motorcycle of a motocross specification, and is equipped with an engine 12 on a cradle-type body frame 11. The engine 12 is shown in a simplified manner. A front portion 13 including a handle, a steering column, a front fork, a front fender, and a front wheel is rotatably supported at the front end portion of the frame 11.

A synthetic resin fuel tank 14 is disposed at the upper part of the body frame 11 and immediately behind the handle bar. A riding type seat 15 on which the rider straddles is provided behind the fuel tank 14 so as to be continuous therewith. Further, a rear cover 16 is provided behind the seat 15 so as to be continuous therewith.
A rear wheel 18 is provided at the rear end portion of the vehicle body frame 11, and a driving force of the engine 12 is given through the chain.

  A radiator 19 is disposed below the fuel tank 14. The left and right side surfaces of the fuel tank 14 and the left and right side surfaces of the radiator 19 are covered with a shroud 100. The shroud 100 is typically shaped to cover the sides of the engine so as not to impede engine cooling. Side covers 200 extend downward from the left and right sides of the rear half of the seat 15. Further, there is a bib plate 300 at the front part.

  In the configuration of the first embodiment, the shroud 100 has an upper and lower two-tone color due to design ingenuity, and is an upper and lower united shroud 100. The upper shroud portion is the upper shroud 110, and the lower shroud 100 is the lower shroud 100. The shroud portion is a lower shroud 120. As a plastic casing of an off-road type motorcycle, members having a two-tone color include a shroud 100, a side cover 200, a bib plate 300, and the like.

The casing that covers the side of the fuel tank 14 is the upper shroud 110, and the casing that covers the side of the radiator 19 is the lower shroud 120. Similarly, in the side cover 200, the upper side cover part is an upper side cover 210, and the lower side cover part is a lower side cover 220. Similarly, in the bib plate 300, the upper bib plate portion is an upper bib plate plate 310 and the lower bib plate plate portion is a lower bib plate 320.
Hereinafter, the shroud 100 will be described in detail as an example, but the same structure can be applied to the side cover 200 and the bib plate 300 as well.

FIG. 2 is a surface view of the upper and lower united shroud according to the first embodiment of the present invention.
FIG. 3 is a rear view of the upper and lower combined shroud.
FIG. 4 is an enlarged view of the back surface of the joint 130.
FIG. 5 is an enlarged view showing the structure of the joint 130 in cross section.

As shown in FIG. 2, the upper and lower combined shroud 100 of the present invention includes an upper shroud 110 and a lower shroud 120. The upper shroud 110 and the lower shroud 120 have a two-tone color if different colors are applied.
A joint 130 is provided at the lower end of the upper shroud 110 and the upper end of the lower shroud 120. The joint 130 serves as a margin for firmly fixing the upper shroud 110 and the lower shroud 120, and also serves as a boundary line that clearly separates the two in design. The two-tone color can be seen more clearly when the line of the joint 130 appears clearly.

  In the present invention, the structure of the joint and the procedure for forming the joint are as follows.

  As shown in FIGS. 3 and 4, many structures are visible on the back surface of the joint 130. In this configuration example, a protruding structure (anchor) 111 of the upper housing 110 is inserted into the through-hole 121 from a large number of square through-holes 121 provided near the upper end of the lower housing. .

  As shown in FIG. 5, the structure of the through hole 121 is formed so that the area on the back surface side is larger than the area on the front surface side. The anchor 111 of the upper housing 110 is fitted so as to fill the through hole 121 having such a structure. With such an anchor structure, the anchor 111 of the upper casing 110 does not come out of the through hole 121 of the lower casing unless the anchor 111 is broken or twisted, and the two are firmly fitted and fixed. I understand that. The region width where the upper and lower shroud components are overlapped may be small, and may be 20 mm or less, for example, about 7 mm. Moreover, the thickness of the overlapping portion may be thin, and for example, a firm fitting is possible even at 5 mm or less (3 mm or the like).

  FIG. 6 is a design example relating to the joint 130 in the experimentally produced shroud of the present invention. The anchor 111 is formed with six units as one unit, and has a style in which a plurality of the units are arranged. The length of the six anchors 111 is 30 mm, and the gap between each anchor is 1 mm. The width of one anchor is 3.5 mm. As can be seen from the cross-sectional view of the AA line including the anchor 111, the width of the joint is 7.0 mm and the thickness is 3.0 mm. The groove provided between the upper housing 110 and the lower housing 120 is 1.0 mm.

  In such an anchor structure, it is not easy to form the upper shroud 110 and the lower shroud 120 separately and then combine them. Therefore, in the present invention, the following procedure is adopted as the formation procedure.

  First, the lower shroud 120 is first molded from a synthetic resin, and a through hole 121 penetrating from the front surface to the back surface is provided with the vicinity of the upper side of the lower shroud 120 as a joint portion. Here, the area on the back surface side is formed to be larger than the area on the front surface side of the through-hole 121.

  Next, the upper shroud 110 is formed of synthetic resin on the upper portion of the lower shroud 120 while being overlapped at the joint portion 130. That is, the upper shroud 110 is formed so as to cover the lower shroud 120 from above at the joint portion 130, and the synthetic resin of the upper shroud enters into the through hole 121 of the lower shroud and is embedded to form the anchor 111.

  Although it is the number of the anchors 111, it is preferable to provide a large number along the joint 130. Since the joining force can be obtained by the anchors 111 one by one, it is advantageous that the number of the anchors 111 is large. However, the joining force obtained by the anchor 111 is also affected by the number of anchors 111, the size of each cross-sectional area of the anchor 111, and the like. It is necessary to adjust the number.

Next, a procedure for forming the anchor structure will be described.
FIG. 7A to FIG. 7D are diagrams schematically illustrating a procedure for forming the anchor structure.
As shown in FIG. 7A, in the present invention, the groove 131 of the joint portion 130 is a margin of the upper shroud 110 and the lower shroud 120 and is a boundary line that clearly separates both from the design. The two-tone color looks better when the line of the groove 131 of the portion 130 is clearly shown.
As shown in FIG. 7A, the lower shroud 120 is formed first.

  Next, as shown in FIG. 7B, the previously formed lower shroud 120 is set in a mold, and the synthetic resin of the upper shroud 110 is injected as shown in FIG. 7C.

  Here, as shown in FIG. 7B and FIG. 7C, the mold 150 is devised so that the boundary line of the joint 130 appears clearly. That is, since the injection pressure of the synthetic resin is also high, in the mold 150 for molding the upper shroud 110, along the portion that becomes the lower end of the upper shroud 110 slightly below the through hole 121 of the joint portion 130 on the surface side of the lower shroud 120. Thus, the mold wall 151 is provided so that the synthetic resin injected for the upper shroud 110 does not flow downward by the mold wall 151, and the boundary between the upper shroud 110 and the lower shroud 120 is clarified. The boundary between the upper shroud 110 and the lower shroud 120 is formed as a groove 131.

That is, the mold wall 151 serves as a partition for controlling the flow of the synthetic resin when the synthetic resin of the upper shroud 110 is injected, and plays a role of forming a groove 131 that makes the boundary between the upper shroud 110 and the lower shroud 120 clear. .
If the edge of the groove 131 is clear, the boundary between the upper shroud 110 and the lower shroud 120 becomes clear.

  Finally, the mold 150 is removed as shown in FIG.

Next, the advantages of the upper and lower combined shroud of the present invention will be summarized.
FIG. 8 is a back view of a conventional screw-type shroud shown for comparison.
FIG. 9 is a cross-sectional view of a conventional screw-type shroud.
In the case of a conventional screw-type shroud, the upper and lower shrouds are formed separately, and then the upper and lower shrouds are fastened by superimposing the two and then screwing with several screws (10 in this example) from the back. ing.

The conventional screw-type shroud has the following disadvantages although the upper and lower shrouds are firmly fixed.
First, the conventional screwing method has a demerit that the manufacturing process increases and the manufacturing cost increases. That is, a procedure for molding the upper and lower shroud parts with synthetic resin, a procedure for superimposing the upper and lower shroud parts, and a procedure for screwing them on the back surfaces of both are necessary, and there are many processes.

  Next, there is a demerit that the limitation of the back space is large. In other words, as shown in FIG. 8, a thickness is required for tightening and screwing the screws. It is necessary to secure a certain width (thickness) of the screwing in order to obtain a sufficient effect of screwing, and to avoid a problem that the screw tip comes out on the surface of the shroud. There must be sufficient thickness. For this reason, as shown in FIG. For example, the width of the region where the upper and lower shrouds are overlapped is large, and is almost 50 mm or more. Moreover, the thickness becomes large, and the thickness which is more than the length of the screw, for example, 30 mm or more is most common.

Next, according to the conventional screwing method, there is a demerit that the shroud is easily cracked.
In the conventional screwing method, since the screw is fastened, bending stress tends to concentrate on the screw 230. Therefore, when bending occurs, cracks are likely to occur in the vicinity of the screw 230, resulting in poor toughness.

  On the other hand, the upper and lower combined shroud of the present invention has many advantages over the conventional screwing method.

  First, the merit that the manufacturing process is small and the manufacturing cost is low can be obtained. In other words, after forming the lower shroud 120, it can be formed by only two synthetic resin moldings in which the upper shroud is stacked and molded, and a plurality of (for example, ten locations) screwing can be performed as in the conventional screwing method. A process becomes unnecessary.

  Next, there is an advantage that there is no protrusion such as a screw on the back surface and there is no limitation on the back space. That is, the upper and lower shrouds are joined by the anchor structure of the through hole 121 and the anchor 111, and there is no obstacle such as a conventional screw, and the back space can be effectively used with a single plate-like body.

  Next, there is no portion where the bending stress such as a screw is concentrated on the back surface, the bending stress can be absorbed by the entire boundary line of the joint portion, and excellent toughness can be obtained. That is, by appropriately disposing the anchor structure including the through-hole 121 and the anchor 111 over the entire boundary line of the joint portion, bending stress can be absorbed by the entire boundary portion of the joint portion, and excellent toughness can be obtained.

  As described above, according to the upper and lower combined type shroud according to the first embodiment, the upper and lower combined type can be formed, and the working process can be dramatically shortened compared to the conventional working process such as screwing, so-called anchor structure. Is formed, and it becomes difficult to separate the two and the structural strength is increased.

  A configuration example of the upper and lower combined shroud according to the second embodiment of the present invention will be described. The upper and lower combined type shroud according to the second embodiment has a so-called key claw structure at the joint portion in addition to the upper and lower combined shroud structure shown in the first embodiment and further increases the bonding force.

The key claw structure will be described.
FIG. 10 is an enlarged view of the cross-sectional structure of the joint portion of the upper and lower shrouds.
As shown in FIG. 10, the upper end of the joint portion of the lower shroud 120 is a key claw structure 122. Further, the lower end of the joint portion of the upper shroud 110 has a key claw structure 112 that fits into the barbed structure 122 at the upper end of the lower shroud.
Also in the second embodiment, the fitting of the key claw structures 112 and 122 is integrally formed when the upper shroud is formed.

  FIG. 11 is a view showing a state in which the fitting of the key claw structures 112 and 122 is integrally made when the upper shroud is formed. As described in the first embodiment, the upper shroud is formed after the lower shroud 120 is formed. At this time, the lower end of the joint portion of the upper shroud 110 wraps around the upper end of the joint portion of the lower shroud 120, and the upper end of the lower shroud 120 The return structure 122 and the return structure 112 at the lower end of the upper shroud are fitted together so that they are combined.

  In this way, by fitting the barbed structure 122 at the upper end of the lower shroud and the barbed structure 112 at the lower end of the upper shroud, the tensile strength in the vertical direction is increased, and the structural strength is also improved against lateral deflection. be able to.

  As described above, according to the upper and lower united shroud according to the second embodiment, in addition to the upper and lower united shroud structure shown in the first embodiment, a so-called key claw structure can be formed at the joint portion to further increase the bonding force. .

  A configuration example of the upper and lower united shroud of the present invention according to Example 3 will be described. In addition to the upper and lower united shroud structure shown in Example 1, the upper and lower united type shroud according to Example 3 also has an anchor structure at the partition wall joint provided to increase the structural strength on the back surface. The bonding strength is further increased.

The anchor structure in the partition wall will be described.
FIG. 12 is a rear view of the upper and lower united shroud according to the third embodiment.
As shown in FIG. 12, partition walls 113 and 123 are provided on the back surface of the upper and lower united shroud according to the third embodiment. The partition walls 113 and 123 themselves are structural devices for increasing the flexural strength of the thin shroud casing. When a structure such as the partition walls 113 and 123 is running, it becomes a resistance against deflection.
It is an idea to provide an anchor structure also at the joint portion between the partition walls 113 and 123.

  First, a configuration example in which the upper end 124 of the partition wall 123 on the lower shroud side is an anchor with respect to the lower end 114 of the partition wall 113 on the upper shroud side is shown.

  As shown in FIG. 12, the partition wall structures 113 and 123 run from the back surface of the upper shroud 110 to the back surface of the lower shroud 120. A partition wall 113 running on the back surface of the upper shroud and a partition wall 123 running on the back surface of the lower shroud are joined at a joint portion.

As shown in FIG. 13, the lower end 124 of the partition wall 123 of the lower shroud is enlarged at the joint portion so that the upper end 114 of the partition wall 113 of the upper shroud includes the upper end 124 of the partition wall of the lower shroud. Is formed. That is, the upper end 124 of the partition wall of the lower shroud is an anchor with respect to the lower end 114 of the partition wall of the upper shroud.
The anchor structure by the upper end 124 of the partition wall of the lower shroud increases the tensile strength in the vertical direction, and further improves the structural strength in the deflection direction.

  Next, a configuration example in which the upper end 114 of the partition wall 113 on the upper shroud side is an anchor with respect to the lower end 124 of the partition wall 123 on the lower shroud side is shown.

  As shown in FIG. 14, the partition wall structures 113 and 123 run from the back surface of the upper shroud 110 to the back surface of the lower shroud 120. A partition wall 113 running on the back surface of the upper shroud and a partition wall 123 running on the back surface of the lower shroud are joined at a joint portion.

As shown in FIG. 15, the lower end 114 of the upper shroud partition wall 113 is large and the upper end 124 of the lower shroud partition wall 123 covers and covers the lower end 114 of the upper shroud partition wall. Is formed. The lower end 114 of the upper shroud partition wall is an anchor to the upper end 124 of the lower shroud partition wall.
Due to the anchor structure by the lower end 114 of the partition wall of the upper shroud, the tensile strength in the vertical direction is increased, and the structural strength in the deflection direction can be improved.

  As described above, according to the upper and lower united shroud according to the third embodiment, in addition to the upper and lower united shroud structure shown in the first embodiment, an anchor structure between the so-called partition walls running on the back surface at the joint portion is further formed. Bonding force can be increased.

  As mentioned above, although the preferable example in the structural example of the upper and lower united type shroud of the present invention has been illustrated and described, it is understood that various modifications can be made without departing from the technical scope of the present invention. I will.

  The upper and lower combined type shroud of the present invention can be applied to a shroud of a motorcycle. In particular, it can be applied to a shroud of an off-road motorcycle.

The figure which shows the motorcycle 10 which concerns on embodiment of this invention. Surface view of upper and lower combined shroud according to embodiment 1 of the present invention The rear view of the upper and lower united shroud according to the first embodiment of the present invention. Enlarged view of the back of the joint 130 Enlarged view showing the structure of the joint 130 in cross section Enlarged view showing a prototype of the joint 130 in cross section The figure which illustrates the procedure which forms an anchor structure typically Back view of a conventional screw-type shroud for comparison Cross-sectional view of conventional screw-type shroud The figure which expanded and showed the cross-section of the junction part of the upper and lower shrouds concerning Example 2. The figure which shows a mode that the fitting of the key claw structures 112 and 122 is integrally formed at the time of shaping | molding of an upper shroud. The back view of an example of the upper and lower united shroud according to the third embodiment Enlarged view of the back of the joint 130 The back view of the other example of the upper and lower united shroud according to the third embodiment Enlarged view of the back of the joint 130 Surface view of a prior art threaded shroud Back view of a conventional screw-integrated shroud

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Motorcycle 11 Body frame 12 Engine 13 Front part 14 Fuel tank 15 Riding seat 16 Rear cover 17 Side cover 18 Rear wheel 19 Radiator 100 Upper and lower unit type shroud 110 Upper shroud 111 Anchor 112 Return structure 113 Partition wall 114 Partition wall 113 Lower end 120 Lower shroud 121 Through hole 122 Return structure 123 Partition wall 124 Upper end of partition wall 123 Joint portion 131 Groove 150 Mold 151 Mold wall

Claims (7)

A motorcycle plastic casing, comprising two plastic casings, an upper plastic casing and a lower plastic casing,
First, the lower plastic casing is molded from a synthetic resin, and a through hole that penetrates from the front surface to the rear surface with the vicinity of the upper side of the lower plastic casing as a joint portion is provided. Molded to be larger,
The upper plastic casing is molded later with a synthetic resin at a position above the lower plastic casing, and the upper plastic casing is formed so as to cover the lower plastic casing from above at the joint portion. An upper and lower united plastic casing, wherein the synthetic resin of the upper plastic casing is inserted into the through hole of the lower plastic casing to serve as an anchor. The upper end of the joint portion of the lower plastic casing has a key claw structure, and the lower end of the joint portion of the upper plastic casing has a key claw structure that fits into the return structure of the upper end of the lower plastic casing. ,
The lower plastic case upper end and the upper plastic lower end return structure are fitted to each other while the lower end of the upper plastic case joining portion wraps around the upper end of the lower plastic case joint. The upper and lower united plastic casing according to claim 1, wherein the two are combined.   In the mold for molding the upper plastic casing, a mold wall is provided so as to be along a portion serving as a lower end of the upper plastic casing slightly below the through hole of the joining portion on the surface side of the lower plastic casing. The synthetic resin injected into the upper plastic casing through the mold wall is prevented from flowing downward, and the boundary between the upper plastic casing and the lower plastic casing is clarified. The upper and lower united plastic housing according to 1 or 2. A partition wall for increasing structural strength is provided on the back surface of each of the upper plastic housing and the lower plastic housing, and the partition wall and the lower plastic housing run on the back surface of the upper plastic housing at the joint portion. And the partition wall running on the back side of
In the joint portion, the upper end of the partition wall of the lower plastic casing is large, and the lower end of the partition wall of the upper plastic casing covers the upper end of the partition wall of the lower plastic casing. The upper end of the partition wall of the lower plastic casing is formed as an anchor with respect to the partition wall of the upper plastic casing. Upper and lower united plastic casing. A partition wall for increasing structural strength is provided on the back surface of each of the upper plastic housing and the lower plastic housing, and the partition wall and the lower plastic housing run on the back surface of the upper plastic housing at the joint portion. And the partition wall running on the back side of
In the joining portion, the lower end of the partition wall of the upper plastic casing is enlarged, and the upper end of the partition wall of the lower plastic casing is covered including the lower end of the partition wall of the upper plastic casing. The lower end of the partition wall of the upper plastic casing serves as an anchor with respect to the partition wall of the lower plastic casing. Upper and lower united plastic casing.   The upper and lower united plastic casing according to any one of claims 1 to 5, wherein the plastic casing includes any one of a shroud, a side cover, and a bib plate of a motorcycle. A method of manufacturing a plastic casing for a motorcycle, comprising: a plastic casing for a motorcycle, comprising two upper and lower plastic casings; an upper plastic casing and a lower plastic casing;
The lower plastic casing is first molded from a synthetic resin, and a through hole is provided that penetrates from the front surface to the rear surface with the vicinity of the upper side of the lower plastic casing as a joint portion. Molded to be larger,
The upper plastic casing is molded later with a synthetic resin at a position above the lower plastic casing, and the upper plastic casing is formed so as to cover the lower plastic casing from above at the joint portion. The manufacturing method of the upper and lower unit type plastic casing, wherein the synthetic resin of the upper plastic casing enters into the through hole of the lower plastic casing and forms an anchor.

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