JP2004316637A - Engine cover fitting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine cover fitting structure of high durability, high vibration damping property, and excellent appearance in which an engine cover is hardly dropped. <P>SOLUTION: The engine cover fitting structure 1 comprising a projecting member 2 having a neck part 20 and a head part 21 larger in diameter than the neck part 20, and a recessed member 3 having an outer circumferential surface small diameter part 34 locked to a fitting hole 91 of a fitting seat 90 facing the projecting member 2, a press-fitting passage 33 to lock the head part 21 of the projecting member 2 press-fitted on the inner circumferential side of the outer circumferential surface small diameter part 34, and a recessed surface 30 to demarcate a retaining space 300 to retain the head part 21 of the projecting member 2 which is communicated with a distal end of the press-fitting passage 33 and press-fitted thereto. In the recessed member 3, a portion to surround at least the recessed surface 30 is formed solid. The head part 21 is disposed closer to a back side of the engine cover 9 than to the fitting hole 91. The inequality is satisfied, in which the inside diameter D1 of the fitting hole 91 < the outside diameter D2 of the head part 21 + (the outside diameter D3 of the outer circumferential surface small diameter part 34 - the inside diameter D4 of the press-fitting passage 33). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine cover for protecting an engine surface.

  The engine cover is arranged, for example, on the upper surface of a cylinder head of the engine. For maintenance of the engine, the engine cover needs to be detachably attached to the engine. Therefore, a mounting structure including a convex member and a concave member (for example, see Patent Document 1) is often used.

  FIG. 5 is a cross-sectional view of an engine cover mounting structure including a convex member and a concave member (hereinafter, abbreviated as “mounting structure” as appropriate). The convex member 101 of the mounting structure 100 is made of metal and has a bolt shape. The convex member 101 includes a screw portion 103, a neck portion 104, and a head portion 105. The screw portion 103 is screwed to the upper surface of the cylinder head 102. A neck 104 is arranged above the screw 103. A head 105 is arranged above the neck 104. The head 105 has a spherical shape. The head 105 has a larger diameter than the neck 104.

The concave member 106 is made of rubber and has a thin cup shape that opens downward. The concave member 106 is locked to a tip end of a mounting seat 109 erected from the lower surface of the engine cover 108. A concave surface 107 having a back spherical shape is arranged substantially at the center of the concave member 106 in the radial direction. The head 105 is press-fitted into the concave surface 107.
US Pat. No. 6,206,604 Japanese Utility Model Publication No. 55-67329

  According to the mounting structure 100, the engine cover 108 can be mounted on the cylinder head 102 by pressing the head 105 into the concave surface 107. Further, the engine cover 108 can be removed from the cylinder head 102 by extracting the head 105 from the inside of the concave surface 107.

  Incidentally, a gap 110 is interposed between the concave surface 107 of the concave member 106 and the outer surface 111. When the gap 110 is provided, the concave surface 107 is easily spread when the convex member 101 is pressed into the concave member 106. Therefore, the press-fit resistance is reduced. However, when the gap 110 is provided, the thickness of the portion surrounding the concave surface 107 of the concave member 106 becomes thin. For this reason, at the time of attaching the engine cover 108, the head 105 may break through a portion surrounding the concave surface 107 of the concave member 106.

  In addition, due to the low press-in resistance, the head 105 is easily detached from the concave surface 107 due to engine driving vibration after the engine cover 108 is attached. That is, the protruding member 101 is easily detached from the concave member 106. In other words, the engine cover 108 easily falls off.

  After the engine cover 108 is attached, the gap 110 acts as a swing allowance for the head 105. That is, the head 105 can relatively swing by the gap 110. Therefore, the engine cover 108 may rattle against the cylinder head 102 due to engine driving vibration or the like.

  In view of this, Patent Document 2 discloses a mounting structure in which an engine cover is attached to a cylinder block in a state where the head of a convex member protrudes toward the surface of the engine cover. FIG. 6 shows a cross-sectional view of the mounting structure described in the document. Parts corresponding to those in FIG. 5 are denoted by the same reference numerals. A mounting hole 112 is formed in the engine cover 108. A rubber ring 113 is fitted on the inner peripheral side of the mounting hole 112. The convex member 101 is provided upright on the surface of the cylinder block 114. The convex member 101 is press-fitted on the inner peripheral side of the rubber ring 113. The head 105 protrudes toward the surface of the engine cover 108. The inner peripheral surface of the rubber ring 113 is pressed against the neck 104.

  According to the mounting structure 100 described in Patent Document 2, the neck 104 is fastened by the rubber ring 113 compressed between the neck 104 and the mounting hole 112. For this reason, after the engine cover 108 is attached, the neck 104, that is, the convex member 101 is unlikely to come off the rubber ring 113. That is, the engine cover 108 does not easily fall off. Also, rattling of the engine cover 108 due to engine driving vibration is small. That is, the vibration damping property is high.

  However, according to the mounting structure 100 described in Patent Document 2, the head 105 protrudes toward the surface of the engine cover 108. For this reason, the appearance is poor. In addition, the above-mentioned difficulty in removing the convex member 101 and the height of the vibration damping property depend on the thickness of the rubber ring 113. That is, when the thickness of the rubber ring 113 is thin, the rubber ring 113 is excessively curved between the inner peripheral surface of the mounting hole 112 and the outer peripheral surface of the neck 104. Therefore, the pressing force applied from the rubber ring 113 to the neck 104 becomes small.

  The engine cover mounting structure of the present invention has been completed in view of the above problems. Therefore, an object of the present invention is to provide an engine cover mounting structure that has high durability, is hard to fall off the engine cover, has high vibration damping properties, and has a good appearance.

  (1) In order to solve the above problem, an engine cover mounting structure according to the present invention includes a convex member protruding from a surface of an engine-side member and having a neck and a head having a diameter larger than the neck. An outer peripheral surface small-diameter portion to be locked in a mounting hole of a mounting seat disposed on the back side of the engine cover so as to face the convex member, and the convex member press-fitted on the inner peripheral side of the outer peripheral surface small-diameter portion. A depression member having a press-fit passage for retaining the head, a concave surface communicating with a rear end of the press-fit passage, and defining a holding space for holding the head of the press-fitted press-fit member. In the mounting structure of the engine cover, at least a portion surrounding the concave surface in the concave material is formed solid, and the head is located closer to the rear surface of the engine cover than the mounting hole at the press-fitting position. The mounting hole diameter is D1, the head is An outer diameter D2, the outer peripheral surface diameter outer diameter D3, the press-fit passage inner diameter D4 as, characterized in that it is a D1 <D2 + (D3-D4). Here, D4 is the inner diameter of the press-fitting passage before press-fitting the convex member.

  That is, in the mounting structure of the present invention, at least a portion of the concave member surrounding the concave surface is formed solid. That is, at least the gap 110 in FIG. 5 is filled. According to the mounting structure of the present invention, the thickness of the portion surrounding the concave surface is increased. Therefore, at the time of attaching the engine cover, there is little possibility that the head pierces the portion surrounding the concave surface. That is, the durability is high.

  Further, since the thickness of the portion surrounding the concave surface is large, the convex member does not easily come off from the concave material after the engine cover is attached. Therefore, the engine cover is unlikely to fall off. In addition, the periphery of the concave surface is formed solid, and there is no gap corresponding to the gap 110 in FIG. Therefore, there is no swing allowance of the head due to such a gap after the engine cover is attached. Therefore, the possibility that the engine cover rattles due to engine driving vibration or the like is small. That is, the vibration damping property is high. Also, after the engine cover is attached, the head does not protrude toward the surface of the engine cover. For this reason, the appearance is good also in the design.

  According to the mounting structure of the present invention, the head is located closer to the rear surface of the engine cover than the mounting hole at the press-fitting position. In addition, D1 <D2 + (D3-D4) is set. Therefore, when the head passes through the press-fit passage, the head is regulated by the mounting hole. That is, an interference occurs. Also in this regard, according to the mounting structure of the present invention, it is difficult for the convex member to come off from the concave member after the engine cover is mounted.

  Preferably, the press-fit ratio (%) = (D2− (D1− (D3−D4))) / (D3−D4) × 100 is set to 2% or more and 35% or less. Here, the press-fit ratio of 2% or more is preferable when it is less than 2%, and when the dimensional difference between the head outer diameter and the neck outer diameter of the convex member is a specified value in consideration of the dimensional variation of each member. This is because the dimensional difference between the inner diameter of the press-fitting passage and the outer diameter of the neck is relatively large, and the function of suppressing the backlash between the convex member and the concave member is weakened. In addition, this is because the protruding member can easily come off from the concave member.

  On the other hand, the reason why the press-fitting ratio is preferably 35% or less is that if it exceeds 35%, a large load is required when inserting the convex member into the concave member, and it becomes difficult to attach the engine cover.

  Preferably, the thickness ratio (%) = (D3−D4) / (2 × D2) × 100 is set to 40% or more and 80% or less. Here, the reason why the thickness ratio is preferably 40% or more is that when the thickness is less than 40%, when the neck portion and the inner surface of the press-fitting passage interfere with each other in the radial direction, the load increases rapidly. Is lost.

  On the other hand, the reason why the wall thickness ratio is preferably 80% or less is that if it exceeds 80%, the load does not increase contrary to the above, and it is difficult to suppress rattling.

  (2) Preferably, a leak hole is provided in a portion surrounding the concave surface to allow air compressed by press-fitting of the convex member to escape from the holding space to the outside. When the convex member is press-fitted into the concave material, air without escape in the concave material is compressed into the holding space. This compressed air acts as a press-fit resistance of the convex member.

  Therefore, a leak hole is formed in a portion surrounding the concave surface of the concave member of the present configuration. The leak hole communicates the holding space with the outside of the concave member. For this reason, according to this configuration, the air compressed in the holding space can escape to the outside through the leak hole. Therefore, the press-in resistance at the time of press-fitting the convex member is reduced.

  (3) Preferably, a tapered surface that is pointed along the press-fitting direction of the convex member is connected to a front side of the press-fitting passage in the concave material so that the convex member can be pressed obliquely into the concave material. It is better to have a configuration that

  Depending on the positional relationship between the engine cover and the engine side member, the axes of the plurality of protrusions may not be arranged in parallel with each other. In this case, the axis of an arbitrary convex member and the axis of a concave material intersect. Even in this case, according to this configuration, the convex member can be obliquely press-fitted into the concave member by the amount of the tapered surface. For this reason, according to this configuration, the mounting structure can be shared among a plurality of vehicle types. Therefore, by mass production, the manufacturing cost of the mounting structure can be reduced.

  According to the present invention, it is possible to provide a mounting structure for an engine cover that has high durability, does not easily come off the engine cover, has high damping properties, and has a good appearance.

  Hereinafter, an embodiment of an engine cover mounting structure of the present invention will be described.

<First embodiment>
First, the configuration of the mounting structure of the present embodiment will be described. FIG. 1 shows a cross-sectional view of the mounting structure of the present embodiment. FIG. 2 is an exploded view of the mounting structure 1 arranged at the upper side in FIG.

  As shown in the drawing, the mounting structure 1 is disposed between the bracket 8 and the engine cover 9. Further, a total of four mounting structures 1 are arranged apart from each other in the vertical direction. Each of the four mounting structures 1 has the same configuration. Therefore, here, one of the two mounting structures 1 arranged above will be described.

  The bracket 8 is included in the engine-side member of the present invention. The bracket 8 is made of metal and has a curved plate shape. The bracket 8 is fixed to a cylinder block (not shown). The bracket 8 has four upper and lower screw holes 80.

  The engine cover 9 is made of resin and has a shallow tray shape. The upper and lower four mounting seats 90 project from the back surface of the engine cover 9. The mounting seat 90 has a box shape with an open top. A keyhole-shaped mounting hole 91 that opens upward is formed in the distal end wall of the mounting seat 90.

  The mounting structure 1 includes a convex member 2 and a concave member 3. The convex member 2 is made of metal and has a bolt shape. The convex member 2 includes a neck portion 20, a head portion 21, and a screw portion 22. The screw portion 22 is inserted into the screw hole 80 of the bracket 8 from the surface side of the bracket 8. A nut 23 is screwed into the screw portion 22. By this screwing, the convex member 2 is protruded from the surface of the bracket 8. The head 21 forms the tip of the convex member 2. The head 21 has a spherical shape. On the root side of the head 21, a columnar neck 20 extends. The maximum diameter of the head 21 is set larger than the diameter of the neck 20. That is, the head 21 has a larger diameter than the neck 20.

  The concave member 3 is made of rubber and has a cylindrical shape, that is, a cup shape with one end opened. The concave member 3 includes a concave surface 30, a leak hole 31, an opening 32, a press-fit passage 33, and a small-diameter portion 34 on the outer peripheral surface. The outer peripheral surface small diameter portion 34 is formed on the outer peripheral surface of the concave member 3. The concave member 3 is locked to the mounting seat 90 by press-fitting the outer peripheral surface small diameter portion 34 into the mounting hole 91.

  The opening 32 is formed on the end surface of the concave member 3 on the bracket 8 side. The opening 32 has a mortar shape. The press-fit passage 33 has a columnar shape and is defined in the depth direction of the opening 32. The neck 20 is housed in the press-fit passage 33. The concave surface 30 has a back spherical shape. The spherical space 300 defined by the concave surface 30 is defined in the depth direction of the press-fit passage 33. The spherical space 300 is included in the holding space of the present invention. In other words, the recesses 3 communicate with the opening 32 → the press-fitting passage 33 → the spherical space 300 in the depth direction from the end face on the bracket 8 side. The head 21 is accommodated in the spherical space 300. The head 21 is fastened by the concave surface 30. The entrance of the leak hole 31 is open to the concave surface 30. The outlet of the leak hole 31 opens to the outer surface 35. The spherical space 300 communicates with the outside through the leak hole 31.

  Next, the movement when the convex member is pressed into the concave member will be described. The inner diameter of the mounting hole 91 (D1 of the present invention) is φ15 mm (tolerance ± 0.1 mm), the outer diameter of the head 21 (D2 of the present invention) is φ8 mm (tolerance ± 0.3 mm), and the outer diameter of the outer surface small diameter portion 34 (D3 of the present invention) is set to φ15.5 mm (tolerance ± 0.4 mm), and the inner diameter of the press-fitting passage 33 before press-fitting the convex member 2 (D4 of the present invention) is set to φ7 mm (tolerance ± 0.5 mm). I have.

  That is, D1 (= 15 mm) <D2 + (D3-D4) (= 16.5 mm) is set (excluding tolerance). Further, the head 21 is disposed closer to the rear surface of the engine cover 9 than the mounting hole 91 at the press-fitting position. Therefore, the head 21 is regulated by the hole edge of the mounting hole 91 when passing through the press-fitting passage 33. That is, an interference occurs. After passing through the press-fit passage 33, the head 21 is released from this interference. The head 21 is housed in the spherical space 300, is fastened by the concave surface 30, and is prevented from coming off by the press-fitting passage 33. In addition, the neck 20 is accommodated in the press-fit passage 33.

  Further, at the time of press-fitting, the head 21 of the convex member 2 passes through the opening 32 and the press-fitting passage 33 in order. As the head 21 passes, the air in the opening 32 and the press-fitting passage 33 is repelled to the spherical space 300. This air is discharged outside through the leak hole 31.

  Next, effects of the mounting structure 1 of the present embodiment will be described. According to the mounting structure 1 of the present embodiment, a portion surrounding the concave surface 30 of the concave member 3 is formed solid. Specifically, a portion between the concave surface 30 and the outer surface 35 is formed solid. Therefore, the thickness surrounding the concave surface 30 is large. For this reason, at the time of attaching the engine cover 9, there is little possibility that the head 21 breaks through a portion surrounding the concave surface 30. That is, the durability is high.

  In addition, since the portion surrounding the concave surface 30 has a large thickness, the convex member 2 does not easily come off the concave member 3 after the engine cover 9 is attached. Therefore, the engine cover 9 does not easily fall off. Further, the portion surrounding the concave surface 30 is formed solid, and there is no gap around the concave surface 30 (see the gap 110 in FIG. 5 described above). Therefore, the possibility that the engine cover 9 will rattle due to engine driving vibration or the like is small. That is, the vibration damping property is high. Further, after the engine cover 9 is attached, the head does not protrude toward the surface of the engine cover 9. For this reason, the appearance is good also in the design.

  Further, according to the mounting structure 1 of the present embodiment, the leak hole 31 is formed in a portion surrounding the concave surface 30 of the concave member 3. Therefore, the air compressed in the spherical space 300 can escape to the outside through the leak hole 31. Therefore, the press-in resistance at the time of press-fitting the convex member 2 is small.

  Further, according to the mounting structure 1 of the present embodiment, the head 21 is fastened by the concave surface 30. Also in this point, the convex member 2 does not easily come off the concave member 3 after the engine cover 9 is attached. Further, according to the mounting structure 1 of the present embodiment, the opening 32 has a mortar shape. For this reason, positioning at the time of press-fitting the convex member 2 is easy.

  According to the mounting structure 1 of the present embodiment, as described above, D1 <D2 + (D3-D4) is set. Further, the head 21 is disposed closer to the rear surface of the engine cover 9 than the mounting hole 91 at the press-fitting position. Therefore, when the head 21 passes through the press-fitting passage 33, the head 21 is regulated by the mounting hole 91. That is, an interference occurs. For this reason, the possibility that the head 21 once held in the spherical space 300 passes through the press-fitting passage 33 and falls off from the opening 32 is small. Also in this regard, according to the mounting structure 1 of the present embodiment, the protruding member 2 is unlikely to come off from the concave member 3 after the engine cover 9 is mounted.

  Further, according to the mounting structure 1 of the present embodiment, the press-fitting ratio is set to about 17.6% (excluding the tolerance). The thickness ratio is set to about 53.1% (excluding tolerance). For this reason, the press-fitting load becomes appropriate and the rattling of the engine cover can be reduced.

<Second embodiment>
The difference between the present embodiment and the first embodiment is that a tapered surface is formed on the front side of the press-fitting passage in the concave member. Therefore, only the differences will be described here.

  FIG. 3 shows a cross-sectional view of the mounting structure of the engine cover of the present embodiment. FIG. 4 shows an enlarged view of the inside of the circle A in FIG. In these figures, parts corresponding to those in FIG. 1 are denoted by the same reference numerals.

  As shown in FIG. 3, two convex members 2 are fixed to the bracket 8. The two convex members 2 are not arranged in parallel. That is, the two convex members 2 are arranged so that their axes intersect each other. As shown in FIG. 4, a tapered surface 36 is formed between the opening 32 of the concave member 3 and the press-fit passage 33. The tapered surface 36 has a bowl shape that is pointed in the direction in which the convex member 2 is pressed.

  The mounting structure 1 of the present embodiment has the same effect as the mounting structure of the first embodiment. Further, according to the mounting structure 1 of the present embodiment, it is possible to prevent interference between the convex member 2 and the concave member 3 within a range where the tapered surface 36 is formed. Therefore, within the above range, the convex member 2 can be pressed into the concave member 3 even when the axis a of the concave member 3 and the axis b of the convex member 2 are not coaxially arranged. . That is, the convex member 2 can be obliquely pressed into the concave member 3.

<Others>
The embodiment of the invention has been described. However, embodiments are not particularly limited to the above embodiments. Various modifications and improvements that can be made by those skilled in the art are also possible. For example, in the above embodiment, the convex member 2 is disposed on the bracket 8, but may be disposed on a cylinder block, a cylinder head, or the like. Further, the leak hole 31 may not be provided.

  Further, D1, D2, D3, and D4 may be appropriately changed within a range that matches the inequality. By changing these values, the degree of swing of the head 21 can be adjusted.

  In addition, the inclination angle θ of the tapered surface 36 (the opening angle of the tapered surface 36 with reference to the axis a of the concave member 3) in the second embodiment is not particularly limited. When the inclination angle is small, the allowable press-fitting angle of the convex member 2 becomes narrow. In addition, when the inclination angle is large, the allowable press-fitting angle of the convex member 2 is widened, but it is difficult for the head 21 to enter the spherical space 300. The inclination angle of the tapered surface 36 may be determined in consideration of these circumstances.

It is sectional drawing of the mounting structure of the engine cover of 1st embodiment. FIG. 2 is an exploded view of a mounting structure arranged at an upper side in FIG. 1. It is sectional drawing of the mounting structure of the engine cover of 2nd embodiment. FIG. 4 is an enlarged view inside a circle A in FIG. 3. It is sectional drawing of the mounting structure of the conventional engine cover. It is sectional drawing of the mounting structure of the conventional engine cover.

Explanation of reference numerals

  1: mounting structure, 2: convex member, 20: neck, 21: head, 22: screw, 23: nut, 3: concave material, 30: concave surface, 300: spherical space (holding space), 31: leak Hole, 32: Opening, 33: Press-in passage, 34: Small outer diameter portion, 35: Outer surface, 36: Tapered surface, 8: Bracket (engine side member), 80: Screw hole, 9: Engine cover, 90: Mounting Seat, 91: mounting hole.

Claims (3)

A projecting member projecting from the surface of the engine-side member, having a neck, and a head having a larger diameter than the neck;
A small-diameter portion on the outer peripheral surface that is locked in a mounting hole of a mounting seat disposed opposite to the convex member on the back side of the engine cover, and the head of the convex member press-fit on an inner peripheral side of the small-diameter portion on the outer peripheral surface. A concave member having a press-fitting passage for retaining the portion, a concave surface defining a holding space for holding the head of the convex member press-fit in communication with the inner end of the press-fitting passage,
An engine cover mounting structure comprising:
In the concave material, at least a portion surrounding the concave surface is formed solid,
The head is located closer to the rear surface of the engine cover than the mounting hole in the press-fit position,
An engine, wherein D1 <D2 + (D3-D4), where D1 is the inner diameter of the mounting hole, D2 is the outer diameter of the head, D3 is the outer diameter of the small diameter portion of the outer peripheral surface, and D4 is the inner diameter of the press-fitting passage. Cover mounting structure.   2. The engine cover mounting structure according to claim 1, wherein a leak hole is formed in a portion surrounding the concave surface to allow air compressed by press fitting of the convex member to escape from the holding space to the outside.   The tapered surface that is sharp along the press-fitting direction of the convex member is connected to a front side of the press-fitting passage in the concave material so that the convex member can be obliquely press-fitted into the concave material. The mounting structure of the described engine cover.

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