JP4411430B2 - Resin parts for vehicles - Google Patents

Description

  The present invention relates to a resin component for a vehicle, and in particular, an improvement of a resin component for a vehicle that is attached to a predetermined part of a vehicle with an attachment member made of a metal or a hard resin material having a hardness higher than that of the resin component body. Concerning structure.

  Conventionally, parts made of a synthetic resin material excellent in light weight and moldability, so-called resin parts, have been used in many vehicles such as automobiles. Recently, such resin parts have been used in various metals. It is also used as a substitute for parts. For example, console boxes, assist grips, etc. have conventionally been made of resin parts, and cylinder head covers, air cleaner cases, intake manifolds, bumpers, etc., which were conventionally made of metal, are made of resin parts. It is becoming a substitute. And in most of those resin parts, resin parts including metal materials such as bolts, screws, rivets, etc. assembled to the resin part main body in order to ensure the attachment to the vehicle It is attached to a predetermined part of the vehicle with an attachment member made of a material sufficiently harder than the main body.

  By the way, when a vehicle to which a resin component as described above is attached causes a collision accident or the like, the resin component is less rigid than a metal component or the like, so that an occupant or a pedestrian is in contact with such a resin component. However, if it is brought into contact with a hard mounting member such as a bolt assembled to a resin part, there is a risk that the damage to the occupant or the pedestrian will be extremely serious.

  For this reason, recently, for example, pedestrians reduce damage caused by contact with hard mounting members (bolts or the like) assembled to resin parts such as an engine cover, a cylinder head cover, and an air cleaner case via a bonnet. Various measures for avoiding contact with such an attachment member or the like have been proposed (see Patent Documents 1 to 3).

  That is, Patent Document 1 discloses a technique in which a shock absorbing structure made of a synthetic resin is integrally formed on a surface facing various types of resin cover bonnets arranged in an engine room. Has been. Further, in Patent Document 2, a detection device that detects a collision with a pedestrian is provided at the front of the vehicle body, and a lifting device that lifts the bonnet by a predetermined amount is provided below the rear end of the bonnet. When a collision with a pedestrian is detected by the device, a sufficient amount of deformation of the bonnet is secured between the various items in the engine room and the bonnet by lifting the bonnet by a predetermined amount with the lifting device. A technique for forming as much space as possible is disclosed. Furthermore, in Patent Document 3, a detection device that detects a collision with a pedestrian is provided at the front of the vehicle body, and an airbag device is disposed on the cowl top, and the detection device detects a collision with a pedestrian. When this is done, a technique has been clarified in which the airbag device is actuated to inflate the airbag on the hood.

  According to these technologies, an impact generated when a pedestrian is brought into contact with a resin part such as various resin covers disposed in an engine room through a bonnet due to a collision accident or the like. Pedestrian contact with rigid mounting members assembled in resin parts is possible by absorbing them advantageously by deformation of the absorbent structure and sufficient deformation of the bonnet, and by exerting a cushioning action by the airbag. Even if it can be avoided or brought into contact with such a mounting member, pedestrian damage caused thereby can be effectively reduced.

However, in the technique disclosed in Patent Document 1, since the shock absorbing structure is provided on the surface facing the bonnet of the resin cover, that is, on the surface that becomes the design surface visually recognized from the outside, the resin The design of the cover made may be impaired, and in the technology disclosed in Patent Document 1 and Patent Document 2, a detection device that detects a collision with a pedestrian, a hood lifting device, an airbag device, etc. Since an expensive device is required, there has been a big problem that an excessive burden is imposed economically.
JP 2000-203378 A JP-A-9-315266 JP 2003-170793 A

  Here, the present invention is made in the background of the circumstances as described above, and the problem to be solved is an attachment member that is assembled to the resin component body and is harder than the resin component body. In a resin component for a vehicle configured to be attached to a predetermined part of a vehicle, the impact generated when a vehicle occupant, a pedestrian, or the like contacts the resin component body when a collision accident occurs is sufficiently and stable. Absorbing and avoiding as much as possible contact of occupants and pedestrians with the mounting members assembled in the resin component body, or occupant and pedestrian damage due to contact with such mounting members is effective It is an object of the present invention to provide a technology that can be advantageously realized without causing a decrease in design of resin parts and an increase in cost.

In the present invention, in order to solve such a problem, the first aspect is that a mounting member having a higher hardness than that of the resin component body is assembled to the resin component body. In addition, the resin component for a vehicle configured to be attached to a predetermined part of the vehicle by the mounting member, and the predetermined part of the vehicle in the resin part main body is attached to the part where the mounting member of the resin part main body is assembled. A bottomed cylindrical boss is integrally formed with a cylindrical portion extending from a surface on the attachment side to the part and a bottom portion that closes a distal end side opening in the extending direction of the cylindrical portion, and the boss The mounting member is assembled to the bottom portion of the boss so as to penetrate the bottom portion, while the axial portion of the cylindrical portion of the boss is positioned on the bottom side of the cylindrical portion with the intermediate portion interposed therebetween The bottom cylindrical wall is open opposite to the bottom. As to or thickened is narrowed relative to the opening-side tubular wall portion located on part side is provided with a stepped portion to subject each stage in the inner peripheral surface of the cylindrical portion, and a bottom portion of the boss By positioning the mounting member assembled to the boss within the cylindrical portion of the boss only within the bottom side cylindrical wall portion, the stepped portion is positioned closer to the opening side of the cylindrical portion than the head of the mounting member. in a vehicle resin component, characterized in that it allowed.

In the second preferred embodiment of the resin component for a vehicle according to the present invention, the cylindrical portion of the boss has a structure that is preferentially bent and deformed at the step portion when an impact is applied to the resin component main body. It is constructed.

  Furthermore, in a third advantageous aspect of the resin component for a vehicle according to the present invention, the resin component main body and the boss are made of a synthetic resin material that can exhibit flexibility at the step portion of the cylindrical portion of the boss. In addition, the stepped portion is formed with a plurality of hollow portions at intervals in the circumferential direction of the cylindrical portion, so that the rigidity of the stepped portion is lowered.

  Furthermore, in a desirable fourth aspect of the vehicle resin component according to the present invention, the resin component main body and the boss have a heat-resistant synthetic resin capable of withstanding the temperature in the engine room during travel of the vehicle. It is integrally formed with the material.

  In short, according to the first aspect of the resin component for a vehicle according to the present invention, the bottomed cylindrical boss is integrally formed on the mounting side surface of the resin component main body to the vehicle where the hard mounting member is assembled, A rigid mounting member is assembled to the bottom of the boss, while the cylindrical portion of the boss has a bottom side cylindrical wall portion and an opening side cylindrical wall portion extending in the axial direction, and an opening side end of the bottom side cylindrical wall portion. A stepped portion extending in a direction intersecting the axial direction of the cylindrical portion from the portion toward the bottom side end portion of the opening side cylindrical wall portion and connecting the bottom side cylindrical wall portion and the opening side cylindrical wall portion And is configured. For this reason, in such a resin component for a vehicle, when an impact is input to the resin component main body from the side opposite to the side attached to the vehicle, the impact load is applied to the bottom side cylindrical wall in the cylindrical portion of the boss. It is designed to act as a compressive load in the height direction for each of the part and the opening side cylindrical wall part, while acting as a shear load for the stepped part, The step portion is structured to be lower than the opening side cylindrical wall portion and the bottom side cylindrical wall portion in the load resistance strength against the impact from the above direction.

  Therefore, in the resin component for a vehicle according to the present invention, for example, an impact generated when a vehicle occupant or a pedestrian is brought into contact with the resin component main body at the time of occurrence of a collision accident or the like while being attached to the vehicle. As a result, stress is concentrated on the stepped portion of the cylindrical portion of the boss, whereby the stepped portion is preferentially deformed over the bottom side cylindrical wall portion and the opening side cylindrical wall portion, and the stepped portion is bent. As a part, the entire cylindrical portion of the boss is bent and deformed. As a result, the impact input to the resin component main body can be sufficiently and stably absorbed based on the bending deformation of the cylindrical portion of the boss.

  In addition, in the vehicle resin component according to the present invention, the structure for absorbing the impact input to the resin component main body is simply provided with a step at the assembly site of the hard mounting member in the resin component main body. To absorb shocks caused by collisions with pedestrians, it is realized by a very simple structure in which a bottom boss-shaped boss is integrally formed and a mounting member is attached to the bottom of the boss. For example, there is no need for an expensive device such as a device for detecting a collision with a pedestrian, a bonnet lifting device, or an air bag device, thereby reducing the cost extremely advantageously. It is done.

  Further, in such a resin component for a vehicle, a boss that exhibits a function of absorbing the impact when an impact is input is provided on the surface of the resin component body on the side of mounting on the vehicle, that is, on a surface that cannot be visually recognized from the outside. Therefore, unlike the conventional resin cover where the shock absorbing structure is provided on the design surface, the surface of the resin component body opposite to the vehicle mounting side, ie, the It can also be advantageously avoided that the designability of the surface that can be visually recognized is impaired.

Therefore, in the vehicle resin part according to the present invention as described above, when a collision accident or the like of the vehicle to which the vehicle is mounted, a vehicle occupant, a pedestrian, etc. Even if it comes into contact with the attachment part, the impact generated at that time is absorbed more fully and stably, so that the attachment member assembled to the resin component body and the occupant or pedestrian can be contacted as much as possible. Damage to a passenger, a pedestrian, and the like due to contact with such an attachment member can be effectively reduced. As a result, the safety of occupants and pedestrians can be achieved extremely effectively, and such safety measures for occupants and pedestrians cause a decrease in the design of resin parts and an increase in costs. It can be realized very advantageously without.

Further, in the vehicle resin component according to the present invention, from where the attachment member is assembled to the bottom of the boss, which is within the cylindrical portion of the boss, as caused to position only on the bottom side tubular wall portion, the resin When an impact is applied to the component body, the tilting deformation of the opening-side cylinder wall at the time of bending deformation of the cylinder is inhibited by the mounting member positioned in the cylinder of the boss. Therefore, the entire cylindrical portion can be bent and deformed with a sufficient amount of deformation. As a result, the impact input to the resin component main body can be absorbed more sufficiently and stably.

  Furthermore, according to the third aspect of the resin component for a vehicle according to the present invention, even if the attachment site of the vehicle to which the resin component is to be attached is, for example, a part that is inevitably vibrated, such as a part of the engine. The bottom part of the boss and the bottom part side cylindrical wall part are vibrated integrally with such an attachment part, but the vibration of the bottom part side cylindrical wall part is based on the flexibility of the step part reduced in rigidity. The vibration is advantageously absorbed by the bending deformation, and the transmission of the vibration to the opening side cylindrical wall portion is effectively cut off or suppressed, so that the vibration of the resin component derived from the vibration of the mounting portion of the vehicle, and further Occurrence of abnormal noise caused by the above can be effectively prevented.

  Furthermore, according to the fourth aspect of the resin component for a vehicle according to the present invention, even if it is exposed to a high temperature atmosphere in the engine room of the running vehicle, it has an excellent shock absorbing performance due to the bending deformation of the cylindrical portion of the boss. Therefore, it can be advantageously applied to various types of resin covers disposed in the engine room.

  Hereinafter, in order to clarify the present invention more specifically, the configuration of the resin component for a vehicle according to the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 schematically shows an engine cover of an automobile as an example of a resin component for a vehicle having a structure according to the present invention in a longitudinal sectional form. As apparent from FIG. 1, the engine cover of the present embodiment has a rectangular top plate portion 10 having a thickness of, for example, about 3 mm, the upper surface of which is a design surface, and four such top plate portions 10. A cover having a rectangular housing shape as a whole, which is integrally formed with four side walls 12 integrally extending downward from one edge and having substantially the same thickness as the top plate 10. It has a main body 14 and is configured. Further, the cover body 14 is formed using polyamide, polypropylene, or the like, thereby providing moderate flexibility and heat resistance that can withstand a high-temperature atmosphere in the running engine room. .

And with respect to such a cover main body 14, the bolt 18 which consists of a metal material harder than the cover main body 14 which is an attachment member for attaching it to the engine 16 (it shows with a dashed-two dotted line in FIG. 1), The engine cover is configured by assembling a plurality of parts. In the present embodiment, the cover body 14 is conventionally attached to the back surface serving as the surface of the top plate 10 attached to the engine 16. boss 20 having a special structure not seen in, each other at a predetermined distance, the same number as the bolt 18 should Ru assembled, provided integrally with, and, with respect to their respective bosses 20, a bolt 18 are assembled one by one.

  More specifically, as apparent from FIGS. 2 and 3, the boss 20 includes a cylindrical portion 22 that integrally extends from the back surface of the top plate portion 10 of the cover body 14, and a top plate portion of the cylindrical portion 22. It has integrally the bottom 24 which obstruct | occludes the front-end | tip opening part on the opposite side to 10 side. Further, the bottom 24 of the boss 20 has a disk shape having substantially the same thickness as the top plate 10 of the cover body 14, and a through hole 26 is provided in the center thereof. The bolt 18 is assembled to the bottom portion 24 by being inserted into the through hole 26 in the leg portion with the lower surface of the head in contact with the upper surface of the bottom portion 24 of the boss 20. Then, the projecting portion of the bottom of the bolt 18 inserted through the through hole 26 of the bottom 24 downward from the bottom 24 is screwed to a predetermined portion of the engine 16, so that the bottom 24 of the boss 20 is The entire cover body 14 is sandwiched between the head of the bolt 18 and the engine 16 so as to be attached to the engine 16.

  On the other hand, the cylindrical portion 22 of the boss 20 has a stepped portion 28 that steps the inner and outer peripheral surfaces of the cylindrical portion 22 so that the lower portion thereof is narrower than the upper portion at the axially intermediate portion. As a whole, it has a substantially stepped cylindrical shape extending substantially vertically downward with substantially the same thickness as the top plate portion 10 of the cover main body 14.

  In other words, in the cylindrical portion 22, the portion on the bottom 24 side located on the lower side thereof is vertically extended from the outer peripheral portion of the upper surface of the bottom 24 by a predetermined height (length in the axial direction). From the bottom-side cylindrical wall portion 30, which is a small-diameter bottom-side cylindrical wall portion 30 that extends straight, while the remaining portion on the opening side located on the upper side extends straight downward from the back surface of the top plate portion 10. Also, a large-diameter opening-side cylindrical wall portion 32 having both a large inner diameter and an outer diameter, and a bottom-side cylindrical wall portion between the bottom-side cylindrical wall portion 30 and the opening-side cylindrical wall portion 32. 30 extends from the upper end portion (opening side end portion) 30 toward the lower end portion (bottom portion 24 side end portion) of the opening side cylindrical wall portion 32 in a substantially horizontal direction, and the bottom side cylindrical wall portion 30 and the opening portion. A step portion 28 that integrally connects the side tube wall portion 32 is provided and configured. The step portion 28 also has substantially the same thickness as the top plate portion 10 of the cover main body 14, and the upper surface thereof is the inner peripheral surface of the bottom side cylindrical wall portion 30 and the opening side cylindrical wall portion 32. While the inner step surface 34 is stepped on the inner peripheral surface, the lower step surface is an outer step surface that steps the outer peripheral surface of the bottom side cylindrical wall portion 30 and the outer peripheral surface of the opening side cylindrical wall portion 32. 36.

  Accordingly, here, for example, when an impact is input from the surface side of the top plate portion 10 in the cover body 14, the impact load is applied to each of the opening side cylindrical wall portion 32 and the bottom side cylindrical wall portion 30. On the other hand, while acting as a compressive load in the height direction, it acts as a shear load with respect to the stepped portion 28. The load-carrying strength against impact from the surface side of 10 is lower than that of the opening-side cylinder wall 32 and the bottom-side cylinder wall 30.

  Therefore, in the engine cover of the present embodiment, as shown in FIG. 4, the cover body 14 is attached to a predetermined portion of the engine 16 with the bolt 18 assembled to the bottom 24 of the boss 20. Below, for example, when a contact accident with a pedestrian occurs and the pedestrian is brought into contact with the cover body 14 via a bonnet (not shown), from the surface side of the cover body 14 to FIG. When an impact is input in the direction indicated by the arrow A, the impact causes stress concentration at the step portion 28 in the cylindrical portion 22 of the boss 20. As a result, the stepped portion 28 is preferentially deformed over the opening-side cylindrical wall portion 32 and the bottom-side cylindrical wall portion 30, and the stepped portion 28 is bent, so that the opening-side cylindrical wall portion 32 and the bottom portion are bent. The side tube wall portion tube portion 22 is deformed so as to fall down, so that the entire tube portion 22 is bent and deformed so as to exhibit a “<” shape in the longitudinal section with the stepped portion 28 as a bent portion. As a result, the impact input to the cover main body 14 can be sufficiently and stably absorbed based on such bending deformation of the cylindrical portion 22 of the boss 20.

  In the present embodiment, the height of the bottom side cylindrical wall portion 30 in the cylindrical portion 22 of the boss 20 is set slightly higher than the height of the head of the bolt 18, so that the cylindrical portion 22 of the boss 20. The head of the bolt 18 accommodated therein is positioned only in the bottom side cylindrical wall portion 30, and the stepped portion 28 is positioned above the bolt 18. Accordingly, when the cylindrical portion 22 of the boss 20 is bent and deformed by an impact input to the cover main body 14, the stepped portion 28 that becomes a bent portion or a part of the opening-side cylindrical wall portion 32 that is deformed to fall down is formed. However, it is advantageously avoided or suppressed that such deformation is inhibited by contact with the head of the bolt 18, etc., and the amount of bending deformation of the entire cylindrical portion 22 is advantageously ensured. Thus, the shock absorbing performance based on the bending deformation of the cylindrical portion 22 can be more fully exhibited.

  Further, the shock absorption characteristics due to the bending deformation of the cylindrical portion 22 of the boss 20 are as follows. The thickness and length of the stepped portion 28, the bottom side cylindrical wall portion 30, and the opening side cylindrical wall portion 32 in the cylindrical portion 22. Or it depends on the height. For this reason, the thickness, length, or height of each portion of the cylindrical portion 22 of the boss 20 is not limited to those illustrated, and is appropriately determined according to the required shock absorption characteristics. Will be.

  As shown in FIGS. 2 and 3, the stepped portion 28 in the cylindrical portion 22 of the boss 20 is opened upward and downward through the inner stepped surface 34 and the outer stepped surface 36. In addition, a plurality of (three in this case) slits 38 are provided in the circumferential direction at equal distances in the circumferential direction so as to extend in the circumferential direction. A portion between adjacent slits 38 is a connecting step portion 40 that connects the bottom-side cylinder wall portion 30 and the opening-side cylinder wall portion 32. The width of each slit 38 and the length m of the connecting step 40 (the distance between adjacent slits 38, where the connecting step 40 has an arc shape, (Corresponding to the length of the string of the portion 40) and the like are appropriately designed to adjust the bending resistance, which is a measure of the ease of bending of the step portion 28, and the cylindrical portion 22 of the boss 20 as described above. The shock absorbing characteristics based on the bending deformation of the tuned material are tuned so as to have desired characteristics. Here, the length m (string length) of the connecting step 40 is about 10 to 20 mm. Of course, this dimension can be variously changed according to the diameter of the stepped portion 28 or the like.

  Further, in the present embodiment, since the plurality of slits 38 are provided in the step portion 28 in the cylindrical portion 22 of the boss 20, the rigidity of the step portion 28 as a whole is moderately lowered, and In the connection step part 40 respectively formed between them, softer flexibility is exhibited. Thereby, the cover main body 14 is attached to a predetermined part of the engine 16 by the bolt 18 assembled to the bottom 24 of the boss 20, and, for example, in the top plate part 10 and each side wall part 12 other than the engine 16. When the engine 16 is driven and vibration of the engine 16 is generated in a state where it cannot be displaced, for example, by abutting against the parts of the cylinder, the bottom side cylinder wall of the cylinder part 22 of the boss 20 is generated. Although the portion 30 is vibrated together with the bottom portion 24, each connection step portion 40 in the step portion 28 is configured to be flexibly deformed and deformed in accordance with the vibration of the bottom side cylindrical wall portion 30. And, by such flexible bending deformation of each connecting step 40, the vibration of the bottom side cylindrical wall 30 is advantageously absorbed, and the transmission of such vibration to the opening side cylindrical wall 32 is effectively cut off. Or it can be suppressed.

  As described above, in the engine cover according to the present embodiment, a pedestrian can pass through the bonnet through the hood when the cover main body 14 is attached to a predetermined part of the engine 16, for example, when a collision accident occurs. When the impact is input from the surface side of the cover main body 14 and the cylindrical portion 22 of the boss 20 is bent and deformed, the impact input from the front surface side of the cover main body 14 is sufficient. Even if the pedestrian comes into contact with the formation site of the boss 20 that is the assembly site of the bolt 18 in the cover body 14, the pedestrian and the bolt 18 Even when the contact of the pedestrian is avoided as much as possible, or when the pedestrian contacts the bolt 18, damage to the pedestrian can be effectively reduced. As a result, pedestrian safety can be achieved extremely effectively.

  Further, in such an engine cover, a boss 20 having a bottomed substantially stepped cylindrical shape is formed integrally with the cover body 14 without using any special device, and the front end side of the boss 20 is formed. By adopting a very simple structure in which the bolt 18 is simply assembled to the bottom 24 located at the position of the pedestrian, it is possible to reliably absorb the impact caused by contact with the pedestrian. Measures can be implemented at low cost.

  Furthermore, in this embodiment, the boss 20 that exhibits the function of absorbing the impact caused by contact with the pedestrian is provided on the back surface opposite to the design surface of the cover body 14, that is, on the surface that is not visible from the outside. Therefore, it is possible to advantageously avoid the deterioration of the design property accompanying the provision of the shock absorbing function.

  Furthermore, in the engine cover of the present embodiment, due to the flexible bending deformation of each connecting step portion 40 composed of a portion between the plurality of slits 38 provided in the step portion 28 in the cylindrical portion 22 of the boss 20, Since the vibration of the bottom side cylindrical wall portion 30 due to the vibration of the engine 16 is advantageously absorbed, the transmission of such vibration to the opening side cylindrical wall portion 32 can be effectively blocked or suppressed. The vibration of the cover main body 14 and the generation of abnormal noise caused by the collision of the cover main body 14 with other components due to such vibration can be effectively prevented.

  Next, several tests conducted by the present inventors on the characteristics of the engine cover having the structure according to the present invention will be described in detail below.

  That is, first, in order to investigate the effect of the size of the slit provided in the stepped portion, in other words, the length of the connecting stepped portion on the impact absorbing performance, the polyamide 6 and 6 are formed, and one side is 100 mm. A prototype engine cover in which a stepped cylindrical boss with a single-sided bottom having a structure as shown in FIG. 2 is integrally formed at the center of one surface of a rectangular top plate having a thickness of 3 mm is actually Prepared and prepared. In addition, here, as this prototype, by providing two slits in the step portion, two connection step portions are formed, and the length of the two connection step portions (the length of the string, that is, The distance between adjacent slits) is 8 mm, respectively, and three slits are provided in the step portion, so that three connecting step portions are formed, and the length of these three connecting step portions is However, by providing three slits in the prototype 2 each having a thickness of 10 mm and the stepped portion, three connecting step portions are formed, and the length of the three connecting step portions is 20 mm, respectively. Three types of prototypes 1 to 3 of the prototype 3 were prepared and prepared.

  Then, using the prepared three types of prototypes 1 to 3 and fixing them on the table at the bottom of the boss so as to be immovable, an impactor having a weight of 3.5 kg and an autography apparatus According to the known method used, a static compression test was performed in a state close to the actual vehicle mounted at a test speed of 20 mm / min.

  As a result, each of the three types of prototypes 1 to 3 has a displacement of 10 mm and a load value of 2 kN or less, which is derived from an actual vehicle test, and is required to absorb the shock in the engine cover. The result satisfied the standard value of quantity. Accordingly, it was recognized that sufficient shock absorbing performance can be ensured when the length of the connecting step portion is set to a value within the range of 8 to 20 mm. In addition, if the length of the connecting step is too short, the rigidity of the stepped portion is excessively lowered and the mounting rigidity of the cover body is also lowered. It is considered that the thickness is preferably about 10 to 20 mm.

  Next, in order to investigate the difference in shock absorbing performance between an engine cover having a structure according to the present invention and an engine cover having a conventional structure, first, three types of prototypes prepared as described above are used. Among them, a prototype 3 in which three connecting step portions having a length of 20 mm were formed in the step portion was prepared as a test product for an engine cover having a structure according to the present invention. Separately, it is made of polyamide 6 and 6, and has one side bottomed cylindrical shape with the same diameter in the axial direction at the center of one surface of a rectangular top plate having a side of 700 mm and a thickness of 3 mm. A prototype 4 of an engine cover in which a boss exhibiting the above is integrally formed was prepared and prepared as a specimen of an engine cover having a conventional structure.

  Then, using these two types of prototypes 3 and 4 and fixing them immovably on the table at the bottom of the boss, the boss formation side of the rectangular top plate of each of the prototypes 3 and 4 A collision test was performed by a known method in which an impactor having a weight of 3.5 kg was caused to collide with a surface opposite to the surface at a speed of 32.5 km / h and an incident angle of 50 °. After that, based on the measurement value by the accelerometer installed in the impactor, the relationship between the acceleration and the elapsed time in each crash test using each prototype 3, 4 and the relationship between the acceleration and the displacement amount, Each was examined. The relationship between the acceleration and the elapsed time in the collision test using the prototype 4 and the relationship between the acceleration and the displacement are shown in FIGS. 5 and 6, respectively. Further, the acceleration and the acceleration in the collision test using the prototype 3 are shown in FIG. The relationship between elapsed time and the relationship between acceleration and displacement are shown in FIGS. 7 and 8, respectively.

  Furthermore, when the impactor damage value: HIC (d) was calculated on the basis of the impactor acceleration measured in the respective collision tests using the prototypes 3 and 4, the prototype 4 having the conventional structure was used. In the impact test, the impactor injury value: HIC (d) was 1074, and in the impact test using the prototype 3 having the structure according to the present invention, the impactor injury value: HIC (d) was 871.

  As is apparent from FIGS. 5 to 8, the maximum acceleration of the impactor in the collision test using the prototype 3 having the structure according to the present invention is the maximum acceleration of the impactor in the collision test using the prototype 4 having the conventional structure. Obviously, it is a small value. Further, even if the impactor injury value: HIC (d) in each impact test is compared, the impactor injury value: HIC (d) in the impact test using the prototype 3 having the structure according to the present invention is safe. The impact value of the impactor: HIC (d) in the impact test using the prototype 4 having the conventional structure is higher than 1000, while the standard value is lower than 1000. From these results, it can be clearly recognized that the engine cover having the structure according to the present invention can exhibit better shock absorbing performance than the engine cover having the conventional structure.

  The specific configuration of the present invention has been described in detail above. However, this is merely an example, and the present invention is not limited by the above description.

  For example, the forming material of the cover main body 14 is not particularly limited as long as it is a synthetic resin material. In addition to the exemplified polyamide and polypropylene, the forming material of a resin component attached to a vehicle such as an automobile such as an ABS resin. Any of the resin materials generally used can be used.

  Further, in the embodiment, the stepped portion 28 is formed at the intermediate portion in the axial direction of the cylindrical portion 22 of the boss 20 so that the bottom side cylindrical wall portion 30 is narrower than the opening side cylindrical wall portion 32. However, on the contrary, the step portion 28 may be provided so that the bottom-side cylinder wall portion 30 is larger than the opening-side cylinder wall portion 32.

  Further, the number of the stepped portions 28 provided in the intermediate portion in the axial direction of the cylindrical portion 22 of the boss 20 is not limited to one as illustrated, but in the intermediate portion in the axial direction of the cylindrical portion 22. Two or more can be provided. In addition, in the case where a plurality of the step portions 28 are provided as described above, the cylindrical wall portion positioned on the bottom 24 side with the single step portion 28 interposed therebetween is narrower than the cylindrical wall portion positioned on the opening side. As a whole, there is no problem even if the enlarged part and the narrowed part are positioned in any order in the axial direction.

  Furthermore, the shape of the cylindrical portion 22 of the boss 20 is not limited to a cylindrical shape, for example, a tapered cylindrical shape, a rectangular cylindrical shape, an elliptical cylindrical shape, or an amorphous cylindrical shape. However, there is no problem. Of course, the shape of the bottom 24 of the boss 20 is appropriately changed according to the shape of the cylindrical portion 22.

  Furthermore, it goes without saying that the shape and thickness of the cover main body 14 and the position, number and size of the boss 20 formed on the cover main body 14 are not particularly limited to those illustrated.

  In addition, in the said embodiment, although the specific example of what applied this invention to the engine cover of a motor vehicle was shown, this invention is other than the resin component for vehicles other than an engine cover, and the resin component for vehicles other than a motor vehicle. Of course, the present invention can be advantageously applied to any of them.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

It is longitudinal cross-sectional explanatory drawing which shows an example of the engine cover according to this invention. FIG. 2 is a partially enlarged explanatory view of FIG. 1. It is III arrow explanatory drawing in FIG. It is explanatory drawing which shows an example of the use condition which attached the engine cover shown by FIG. 1 to the engine, Comprising: The cylinder part of the boss | hub was deform | transformed by the impact input into the cover main body. It is a graph which shows the relationship between the acceleration of an impactor at the time of implementing a collision test using the prototype of the engine cover which has a conventional structure, and the elapsed time from a collision. It is a graph which shows the relationship between the acceleration of an impactor at the time of implementing a collision test using the prototype of the engine cover which has a conventional structure, and the amount of displacement of a prototype. It is a graph which shows the relationship between the acceleration of an impactor at the time of implementing a collision test using the prototype of the engine cover which has a structure according to this invention, and the elapsed time from a collision. It is a graph which shows the relationship between the acceleration of an impactor at the time of implementing a collision test using the prototype of the engine cover which has a structure according to this invention, and the amount of displacement of a prototype.

Explanation of symbols

DESCRIPTION OF SYMBOLS 14 Cover main body 16 Engine 18 Bolt 20 Boss 22 Cylinder part 24 Bottom part 28 Step part 30 Bottom part side cylinder wall part 32 Opening part side cylinder wall part 38 Slit 40 Connection step part

Claims (4)

With respect to the resin component main body, a mounting member having a higher hardness than the resin component main body is assembled, and the mounting member is a vehicle resin component configured to be attached to a predetermined part of the vehicle.
A cylindrical portion that extends toward the mounting side of the resin component main body to the predetermined portion of the vehicle, and a front end side opening in the extending direction of the cylindrical portion, at the portion where the mounting member of the resin component main body is assembled. A bottomed cylindrical boss having a closed bottom portion is integrally formed, and the mounting member is assembled to the bottom portion of the boss so as to penetrate the bottom portion. A bottom side cylindrical wall portion positioned on the bottom side of the cylindrical portion with the intermediate portion interposed therebetween is located on an opening side cylindrical wall portion positioned on the opening side opposite to the bottom side. On the other hand, a step portion for stepping the cylindrical portion on the inner and outer peripheral surfaces is provided so as to be narrowed or enlarged , and the mounting member assembled to the bottom portion of the boss is attached to the boss. By locating only within the bottom side cylinder wall within the cylinder, The difference unit, a vehicle resin component, characterized in that allowed position on the opening side of the cylindrical portion than the head portion of the mounting member.
The resin part for a vehicle according to claim 1 , wherein the cylindrical portion of the boss has a structure that is preferentially bent and deformed at the stepped portion when an impact is applied to the resin component main body .
  The resin component main body and the boss are integrally formed using a synthetic resin material capable of exhibiting flexibility at the step portion of the cylindrical portion of the boss, and the gap portion is formed on the step portion. The resin part for vehicles according to claim 1 or 2 by which rigidity of the level difference part is made low by forming two or more at intervals in the peripheral direction of a cylinder part. The said resin component main body and the said boss | hub are integrally molded by the synthetic resin material provided with the heat resistance which can endure the temperature in the engine compartment during driving | running | working of the said vehicle. The resin part for vehicles as described in a term.

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