Mating surface structure of fastened parts

Abstract

To provide a mating face structure of a fastened member which can prevent the contact of a lubricant and a non-metal seal material when fastening the fasten members which sandwich the non-metal seal material therebetween.SOLUTION: A seal material 4a is formed into an annular shape which continues along mating faces 6, 7 of fasten members (cylinder head cover 11 and cylinder head 12) which are fastened to each other. The seal material 4a is sandwiched by the mating faces 6, 7 of the fastened members, and seals an internal space 8 which is formed inside by the fastened members which are fastened to each other. An annular recess 3 is formed in a position inside the seal member 4a of the mating face 6 of the cylinder head cover 11 of either of the fastened members which are fastened to each other, a labyrinth annular protrusion 2 is formed in a position inside the seal material 4a of the other mating face 7 of the cylinder head 12, and a labyrinth structure 1 which is formed by the mating of both the recess and the protrusion is arranged inside the seal material 4a.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a mating surface structure of fastened members that are fastened with a non-metallic sealing material sandwiched therebetween. [Background technology]

[0002] An internal combustion engine for an automobile or the like is generally constructed by fastening a cylinder head cover, a cylinder head, a cylinder block, an oil pan, etc., at their mating surfaces with a sealing material (gasket) sandwiched therebetween. Inside the internal combustion engine, for example, in the internal space covered by the cylinder head and the cylinder head cover, a valve system consisting of a camshaft, intake and exhaust valves, etc., is housed, and lubricating oil (oil) is supplied to ensure smooth movement of each metal part. The sealing material seals the internal combustion engine so that the lubricating oil supplied to each part in this way does not splash onto the inner wall of the internal combustion engine and leak to the outside from the fastening points of each mating surface, and various technologies have been devised in the past to obtain a good sealing structure using sealing materials.

[0003] For example, Patent Document 1 discloses a sealing structure for a three-surface mating portion at the mating surfaces of three members, a cylinder head, a cylinder head cover, and a front cover (attached to secure a storage space for drive transmission members such as a chain and gears). A groove is formed on the mating surface of the front cover with the cylinder head, etc., and a front cover gasket is stored in this groove in a semi-buried state. The front cover gasket has a mountain-shaped end, and the top of the mountain shape is located at a position protruding from each of the upper mating surfaces of the cylinder head and the front cover. As a result, the mountain-shaped end is butted against the sealing surface of the cylinder head cover gasket in a perpendicular state, and both are compressed and elastically deformed. As such a sealing material aimed at elastic deformation, non-metallic materials such as liquid gaskets, synthetic resins, and rubber are often used. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-145422 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional sealing structure of the internal combustion engine, the non-metallic seal material is exposed inside the internal combustion engine, and the lubricating oil can easily splash and adhere to it. When the lubricating oil adheres to such a non-metallic seal material, some of the components constituting the seal material may dissolve in the lubricating oil. This may cause the viscosity of the lubricating oil to decrease, leading to deterioration of the lubricating oil, a drop in oil pressure, etc.

[0006] The present invention was devised in consideration of these points, and its objective is to provide a mating surface structure for fastened parts that can prevent contact between lubricating oil and a non-metallic sealing material when the fastened parts are fastened with a non-metallic sealing material sandwiched between them. [Means for solving the problem]

[0007] According to one feature of the present disclosure, the mating surface structure of the fastened members is a mating surface structure of the fastened members that are fastened with a non-metallic sealing material sandwiched therebetween, the sealing material being formed as a continuous ring along the mating surfaces of the fastened fastened members, and being sandwiched between the mating surfaces of the fastened members to seal a cavity formed inside the fastened fastened members, and a one-side seal inner portion that is located inside the sealing material on the mating surface of one of the fastened fastened members, is a mating surface structure of fastened members in which an annular recess is provided which is a continuous annular recess along the mating surface, and a labyrinth annular protrusion which is a continuous annular protrusion along the mating surface is provided on the other seal inner portion, which is a position more inward than the sealing material on the mating surface of the other of the fastened members which are fastened, and a labyrinth structure in which the labyrinth annular protrusion is accommodated in the annular recess without being in close contact with the labyrinth, is provided more inward than the sealing material.

[0008] According to this, because the labyrinth structure formed by the mating surfaces of the fastened parts exists inside the sealing material, even if the lubricating oil splashed from inside the cavity to the outside adheres to the inner wall of the fastened parts, the adhered lubricating oil will simply flow down the inner wall and will not reach the sealing material located at the back of the labyrinth structure, thereby preventing contact between the lubricating oil and the non-metallic sealing material.

[0009] According to another feature of the present invention, in the mating surface structure of the fastened members, the annular recess is formed so as to open downward, and the labyrinth annular protrusion is formed so as to protrude upward.

[0010] According to this, the lubricating oil adhering to the inner wall flows downward along the inner wall due to gravity. Also, the annular recess also opens downward. Therefore, the lubricating oil flowing downward does not enter the annular recess that also opens downward. Therefore, it is possible to further prevent contact between the lubricating oil and the non-metallic seal material.

[0011] According to another feature of the present invention, in the mating surface structure of the fastened members, at least one of the one seal inner portion and the other seal inner portion is provided with an annular convex portion for a partition, which is a ring-shaped convex portion that continues along the mating surface, separate from the annular convex portion for the labyrinth, and the annular convex portion for the partition is in close contact with the mating surface of the mating surface on which the annular convex portion for the partition is provided, at a position intermediate between the labyrinth structure and the sealing material.

[0012] With this, even if the lubricating oil should try to reach the seal through the gaps in the labyrinth structure, the annular partition protrusion blocks the gap between the mating surfaces just before the seal, so the lubricating oil will not reach the seal, thereby making it possible to further prevent contact between the lubricating oil and the non-metallic seal.

[0013] According to another feature of the present invention, in the mating surface structure of the fastened members, an annular protrusion for the partition is provided on both the inner portion of the one seal and the inner portion of the other seal, and the annular protrusions for the partition are provided in positions where they do not collide with each other.

[0014] According to this, the gap between the mating surfaces is blocked by the two partition wall annular convex portions, so that contact between the lubricating oil and the non-metallic sealing material can be further prevented.

[0015] According to another feature of the present invention, in the mating surface structure of the fastened members, the annular convex portion for the partition is formed in a tapered shape, and is crushed and tightly adhered to the opposing mating surface when the fastened members are fastened, or is recessed into the opposing mating surface and tightly adhered to the opposing mating surface.

[0016] This increases the degree of adhesion between the partition annular convex portion and the mating surface on the other side, making it possible to further prevent contact between the lubricating oil and the non-metallic sealing material.

[0017] According to one feature of the present disclosure, the mating surface structure of the fastened members is a mating surface structure of fastened members fastened with a non-metallic sealing material sandwiched therebetween, the sealing material being formed in a continuous ring shape along the mating surfaces of the fastened fastened members and being sandwiched between the mating surfaces of each of the fastened members to seal a cavity formed inside the fastened fastened members, and at least one of a one-side seal inner portion, which is located more inward than the sealing material on the mating surface of one of the fastened fastened members, and a other-side seal inner portion, which is located more inward than the sealing material on the mating surface of the other of the fastened fastened members, is provided with a partition annular convex portion which is a convex portion having a continuous ring shape along the mating surfaces, and the partition annular convex portion is in close contact with a mating surface that is the counterpart of the mating surface on which the partition annular convex portion is provided, on the inside of the sealing material.

[0018] According to this, by sealing the gap between the mating surfaces on the inside of the seal material, even if the lubricating oil splashed from inside the cavity toward the outside adheres to the inner wall of the fastened member, the adhered lubricating oil will not reach the seal material through the gap between the mating surfaces, thereby preventing contact between the lubricating oil and the non-metallic seal material. [Brief description of the drawings]

[0019] [Figure 1] 1 is a diagram showing a part of the external appearance of an internal combustion engine having a mating surface structure for fastened members according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Diagram 3] 2 shows the cylinder head cover and the cylinder head before fastening. [Figure 4] FIG. 11 is a view showing a cylinder head cover and a cylinder head before fastening according to a second embodiment. [Diagram 5] FIG. 11 is a view showing a cylinder head cover and a cylinder head fastened together according to a second embodiment. [Figure 6] FIG. 11 is a view showing a cylinder head cover and a cylinder head before fastening according to a third embodiment. [Figure 7] FIG. 11 is a view showing a cylinder head cover and a cylinder head fastened together according to a third embodiment. [Figure 8] FIG. 11 is a view showing a cylinder head cover and a cylinder head before fastening according to a fourth embodiment. [Figure 9] FIG. 11 is a view showing a cylinder head cover and a cylinder head fastened together according to a fourth embodiment. [Figure 10] FIG. 11 is a view showing a cylinder head cover and a cylinder head before being fastened together according to another embodiment. [Figure 11] FIG. 13 is a diagram showing a cylinder head cover and a cylinder head fastened together according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] [Matching surface structure of the fastening member according to embodiment 1 (FIGS. 1 to 3)] A first embodiment of a mating surface structure of fastened members according to the present invention will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a diagram showing a part of the external appearance of an internal combustion engine having the mating surface structure of fastened members according to the first embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 shows a cylinder head cover and a cylinder head before fastening.

[0021] As shown in Fig. 1, an internal combustion engine 10 is configured by fastening a cylinder head cover 11, a cylinder head 12, a cylinder block 13, etc., at their mating surfaces with a sealing material (gasket) sandwiched therebetween. The cylinder block 13 has cylindrical portions of a plurality of cylinders (air cylinders). The cylinder head 12 has a structure in which a combustion chamber for the cylinder is formed at the mating surface facing the cylinder block 13, and a space formed on the side covered by the cylinder head cover 11 supports a valve system consisting of a camshaft, intake and exhaust valves, etc. The cylinder head cover 11 is provided on the top of the cylinder head 12, and prevents the scattering of lubricating oil (oil) supplied for lubricating the valve system housed in the cylinder head 12 and the intrusion of foreign matter.

[0022] In an internal combustion engine 10 configured as described above, for example, as shown in Fig. 1, the cylinder head cover 11 and the cylinder head 12 have flanges 14, 15 formed around their entire circumferences, and are fastened together using bolts 9a-9c, etc. as part of the fastening parts. Similarly, as shown in Fig. 1, the cylinder head 12 and the cylinder block 13 have flanges 16, 17 formed around their entire circumferences, and are fastened together using bolt 9d, etc.

[0023] As shown in Fig. 2, the sealing material 4a is a liquid gasket (see Fig. 3) fixed between the mating surfaces 6, 7 of the flange portions 14, 15. The sealing material 4a fills continuously between the mating surfaces 6, 7 of the flange portions 14, 15 of the fastened cylinder head cover 11 and cylinder head 12. Because the sealing material 4a is formed around the entire circumference of the flange portions 14, 15, it forms a continuous ring shape along the mating surfaces 6, 7. The sealing material 4a sandwiched between the mating surfaces 6, 7 seals the internal space 8 (where the valve system is housed) formed by the cylinder head cover 11 and the cylinder head 12.

[0024] A cylinder head gasket (not shown) is also sandwiched between the cylinder head 12 and the cylinder block 13 as a sealing material. The cylinder head gasket seals the space (e.g., the combustion chamber) formed by the cylinder head 12 and the cylinder block 13 so as to withstand the high-pressure combustion gas generated in the combustion chamber. If the cylinder head gasket is a metal gasket made only of metal, the mating surface structure of the fastened members according to the present invention is not applied to the cylinder head 12 and the cylinder block 13. However, in some cases, the surface of the cylinder head gasket is covered with fluororubber or silicone rubber to improve adhesion, and in such cases, the mating surface structure of the fastened members according to the present invention may be applied.

[0025] As shown in FIG. 2, for example, the cylinder head cover 11 has an annular recess 3 provided on the mating surface 6 of the flange portion 14. The annular recess 3 is desirably provided on the mating surface 6 in a range on the inside of the location where the seal material 4a is fixed. For example, the annular recess 3 is provided on the innermost side of the mating surface 6. The annular recess 3 is formed so as to open downward. The annular recess 3 is formed, for example, by an inner wall 3b of the cylinder head cover 11 and a partition wall 3a having a substantially L-shaped cross section. The partition wall 3a is provided, for example, integrally with the inner wall 3b so that a gap of a predetermined width (the width of the labyrinth annular protrusion 2) is formed between the inner wall 3b and the partition wall 3a.

[0026] On the other hand, as shown in FIG. 2, the cylinder head 12 is provided with an annular labyrinth convex portion 2 corresponding to the annular recess 3 on the mating surface 7 of the flange portion 15. The annular labyrinth convex portion 2 is desirably provided on the mating surface 7 in a range inside the location where the sealing material 4a is fixed. For example, the annular labyrinth convex portion 2 is provided on the innermost side of the mating surface 7. The annular labyrinth convex portion 2 is formed so as to protrude upward. The annular labyrinth convex portion 2 is accommodated without being in close contact with the annular recess 3 by fastening the cylinder head cover 11 to the cylinder head 12, and as a result, the labyrinth structure 1 is formed. The labyrinth structure 1 is formed inside the sealing material 4a sandwiched and fixed between the mating surfaces 6 and 7. The sealing material 4a is formed by applying a liquid gasket by the FIPG (Formed In Place Gasket) method, for example.

[0027] As shown in FIG. 3, for example, the liquid gasket 4b is applied to the mating surface 7 of the flange portion 15 of the cylinder head 12. When the cylinder head 12 and the cylinder head cover 11 are fastened together, the mating surface 6 of the flange portion 14 is made to face the mating surface 7 of the flange portion 15. Then, the cylinder head cover 11 is placed on the cylinder head 12, and the two are fastened together by fastening parts including bolts 9a to 9c. At this time, the liquid gasket 4b spreads and adheres to the mating surfaces 6 and 7, forming a sealing material 4a. At this time, a part of the liquid gasket 4b may be pushed into the gap of the labyrinth structure 1. The gap formed by the labyrinth annular convex portion 2 and the annular concave portion 3 is intricate, and a sufficient distance is secured to the internal space 8, so that the liquid gasket 4b does not reach the internal space 8.

[0028] By configuring such a labyrinth structure 1, even if the lubricating oil is splashed and adheres to the partition 3a or inner wall 3b of the cylinder head cover 11 when the valve system is operated in the internal space 8, the adhered lubricating oil will simply flow downward along the partition 3a or inner wall 3b and will not reach the sealing material 4a located at the back of the labyrinth structure 1.

[0029] [Matching surface structure of the fastening member according to embodiment 2 (Figs. 4 and 5)] The second embodiment will be described with reference to Figures 4 and 5. The second embodiment is formed in substantially the same manner as the first embodiment. As shown in Figure 4, the cylinder head cover 21 according to the second embodiment is provided with a partition annular protrusion 5a on the mating surface 6 of the flange portion 14. The cylinder head cover 21 is made of metal, and the partition annular protrusion 5a is formed in a continuous ring shape along the mating surface 6 integrally with the flange portion 14, as the flange portion 14 is formed over the entire circumference.

[0030] As shown in FIG. 4, for example, the liquid gasket 4b is applied to the mating surface 7 of the flange portion 15 of the cylinder head 12. It is preferable that the liquid gasket 4b is applied to a position on the mating surface 7 that is outside the partition annular protrusion 5a. When the cylinder head 12 and the cylinder head cover 21 are fastened together, the mating surface 6 of the flange portion 14 is made to face the mating surface 7 of the flange portion 15. Then, the cylinder head cover 21 is placed on the cylinder head 12, and the two are fastened together by fastening parts including bolts 9a to 9c. Since the partition annular protrusion 5a is tapered, it is crushed by the mating surface 7 of the flange portion 15 when the cylinder head 12 and the cylinder head cover 21 are fastened together, and is in close contact with the mating surface 7. As a result, the partition annular protrusion 5a becomes the partition portion 5b that completely fills the gap between the mating surfaces 6 and 7, as shown in FIG. 5. The partition portion 5b is located in the middle between the labyrinth structure 1 and the seal material 4a.

[0031] [Matching surface structure of the fastening member according to embodiment 3 (FIGS. 6 and 7)] The third embodiment will be described with reference to Figs. 6 and 7. The third embodiment is formed in substantially the same manner as the second embodiment. As shown in Fig. 6, the cylinder head 32 according to the third embodiment is provided with a partition annular protrusion 5c on the mating surface 7 of the flange portion 15. The partition annular protrusion 5c is formed in a continuous ring shape along the mating surface 6 as the flange portion 15 is formed over the entire circumference. The partition annular protrusion 5a and the partition annular protrusion 5c are provided at positions where they do not collide with each other.

[0032] As shown in FIG. 6, for example, the liquid gasket 4b is applied to the mating surface 7 of the flange portion 15 of the cylinder head 32. The liquid gasket 4b is preferably applied to a position on the mating surface 7 that is outside the partition annular protrusion 5c. When the cylinder head 32 and the cylinder head cover 21 are fastened together, the mating surface 6 of the flange portion 14 is made to face the mating surface 7 of the flange portion 15. Then, the cylinder head cover 21 is placed on the cylinder head 32, and the two are fastened together by fastening parts including bolts 9a to 9c. Since the partition annular protrusion 5a and the partition annular protrusion 5c are tapered, they are crushed by the mating surfaces 6, 7 when the cylinder head 32 and the cylinder head cover 21 are fastened together, and are in close contact with the mating surfaces 6, 7, respectively. As a result, the partition annular protrusion 5a and the partition annular protrusion 5c become partition portions 5b, 5d that completely fill the gap between the mating surfaces 6, 7, as shown in FIG. 7. The partitions 5b and 5d are positioned midway between the labyrinth structure 1 and the seal material 4a.

[0033] [Matching surface structure of the fastening member according to embodiment 4 (FIGS. 8 and 9)] The fourth embodiment will be described with reference to Figures 8 and 9. The fourth embodiment is formed in almost the same manner as the second embodiment. As shown in Figure 8, a cylinder head cover 41 and a cylinder head 42 according to the fourth embodiment are not formed with a labyrinth structure, but only have a partition annular protrusion 5a provided on the mating surface 6 of the flange portion 14. The partition annular protrusion 5a is formed in a continuous ring shape along the mating surface 6, as the flange portion 14 is formed around the entire circumference.

[0034] As shown in FIG. 8, for example, a liquid gasket 4b is applied to the mating surface 7 of the flange portion 15 of the cylinder head 42. The liquid gasket 4b is preferably applied to a position on the mating surface 7 that is outside the partition annular protrusion 5a. When the cylinder head 42 and the cylinder head cover 41 are fastened together, the mating surface 6 of the flange portion 14 is made to face the mating surface 7 of the flange portion 15. Then, the cylinder head cover 41 is placed on the cylinder head 42, and the two are fastened together by fastening parts including bolts 9a to 9c. The partition annular protrusion 5a is tapered, so that when the cylinder head 42 and the cylinder head cover 41 are fastened together, the partition annular protrusion 5a is pressed against the mating surface 7 of the flange portion 15 and is in close contact with the mating surface 7. As a result, the partition annular protrusion 5a becomes a partition portion 5b that completely fills the gap between the mating surfaces 6 and 7, as shown in FIG. 9. The partition wall portion 5b is in intimate contact with a mating surface 7 that is the counterpart of the mating surface 6 on which the partition wall annular protrusion 5a is provided, on the inner side of the seal material 4a.

[0035] The control device for an internal combustion engine according to the present invention is not limited to the appearance, configuration, structure, etc. described in this embodiment, and various changes, additions, and deletions are possible within the scope of the present invention. For example, in this embodiment, the cylinder head cover 11 and the cylinder head 12 in the internal combustion engine 10 have been described as an example of the mating surface structure of the fastened members according to the present invention. However, the present invention may be applied to the mating surface structure of the cylinder head 12 and the cylinder block 13, or to the mating surface structure of the cylinder block 13 and the oil pan. Furthermore, the present invention may be applied to any mating surface structure of the fastened members fastened with a nonmetallic sealant sandwiched therebetween, not limited to the internal combustion engine 10, but may be applied to, for example, a joint portion of a pipe.

[0036] In the first embodiment, the annular recess 3 is provided on the mating surface 6 of the flange portion 14 of the cylinder head cover 11 (so that the annular recess 3 is formed so as to open downward), and the labyrinth annular protrusion 2 is provided on the mating surface 7 of the flange portion 15 of the cylinder head 12 (so that the labyrinth annular protrusion 2 is formed so as to protrude upward). However, the locations where the two are provided may be interchanged. That is, the annular recess 3 may be provided on the mating surface 7, and the labyrinth annular protrusion 2 may be provided on the mating surface 6.

[0037] In the second embodiment, the partition annular protrusion 5a is provided on the mating surface 6 of the flange portion 14 of the cylinder head cover 21, and is crushed against the mating surface 7 of the flange portion 15 by fastening the cylinder head 12 and the cylinder head cover 21. However, for example, as shown in FIG. 10, the partition annular protrusion 5e may be provided on the mating surface 7 facing the mating surface 6. In that case, the partition annular protrusion 5a is crushed against the mating surface 6 by fastening the cylinder head 52 and the cylinder head cover 51. The cylinder head cover 51 may be made of synthetic resin instead of metal. In that case, the partition annular protrusion 5e is pressed into the cylinder head cover 51 and adheres closely to it, as shown in FIG. 11. The partition annular protrusion 5e pressed into the cylinder head cover 51 has the same function as the partition portion 5b.

[0038] In addition, in the second to fourth embodiments, the annular partition protrusions 5a, 5c are described as being tapered, but since the protrusions 5a, 5c are eventually pressed against the mating surface of the other side, they may have any shape, for example, a semicircular cross section. [Explanation of symbols]

[0039] 1. Labyrinth structure 2 Annular protrusion for labyrinth 3 Annular recess 3a Bulkhead 3b Inner wall 4a Sealing material 4b Liquid gasket 5a, 5c, 5e Annular protrusions for bulkheads 5b, 5d Partition part 6, 7 Mating surface 8. Interior Space 9a~9d Bolts 10 Internal combustion engine 11, 21, 41, 51 Cylinder head cover 12, 32, 42, 52 Cylinder head 13 Cylinder block 14~17 Flange

Claims

1. A mating surface structure of fastened members fastened with a non-metallic sealing material therebetween, the sealing material is formed into a continuous ring shape along the mating surfaces of the fastened workpieces and is sandwiched between the mating surfaces of the fastened workpieces to seal a cavity formed inside the fastened workpieces, a ring-shaped recess is provided on one seal inner side, which is located on the inner side of the mating surface of one of the fastened members, and is a recess having a ring shape that is continuous along the mating surface; a labyrinth annular convex portion which is a convex portion having a ring shape and which is continuous along the mating surface is provided on an inner side of the other seal, the inner side being located on the inner side of the mating surface of the other of the fastened members, the labyrinth annular convex portion being a convex portion having a ring shape and which is continuous along the mating surface, a labyrinth structure in which the labyrinth annular convex portion is accommodated in the annular concave portion without being in close contact with the labyrinth annular convex portion is provided on the inner side of the sealing material, a partition wall-forming annular convex portion which is a convex portion having an annular shape and which is continuous along the mating surface, is provided on at least one of the first seal inner portion and the second seal inner portion, separately from the labyrinth-forming annular convex portion, the partition wall annular convex portion is in close contact with a mating surface that is a mating surface of the mating surface on which the partition wall annular convex portion is provided, at a position intermediate between the labyrinth structure and the sealing material; Mating surface structure of fastened parts.

2. The mating surface structure of the fastened members according to claim 1, The annular recess is formed so as to open downward, and the labyrinth annular protrusion is formed so as to protrude upward. Mating surface structure of fastened parts.

3. The mating surface structure of the fastened members according to claim 1, the partition wall annular protrusion is provided on both the one seal inner portion and the other seal inner portion, The partition annular protrusions are provided at positions where they do not collide with each other. Mating surface structure of fastened parts.

4. The mating surface structure of the fastened members according to claim 1 or 3, The partition wall annular protrusion is formed in a tapered shape, and is pressed against and closely adheres to the mating surface of the other side by fastening the fastened members, or is embedded in and closely adheres to the mating surface of the other side. Mating surface structure of fastened parts.

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