JP2012017722A - Engine seal structure - Google Patents

Abstract

An object of the present invention is to improve the reliability of engine sealing and improve engine maintenance.
A joining surface 30A of a left side cover 30 joined to the cylinder head 16 and the head cover 17 intersects each joining surface 16A, 17A where a plurality of cylinder heads 16 and a head cover 17 intersect 3. A gasket 36 made of an elastic material, which has a plane crossing portion X and is interposed between the joint surface 16A of the cylinder head 16 and the joint surface 17A of the head cover 17, the cylinder head extension portion 32 of the cylinder head 16, and the head cover 17 A seal molding 41 made of an elastic material is provided between the head cover extension 33 and the joint surface 30A of the left side cover 30, and the gasket extension 36B of the gasket 36 and the seal molding 41 are abutted against each other. It has been done.
[Selection] Figure 10

Description

  The present invention relates to an engine seal structure for sealing a fluid inside an engine case.

  In a motorcycle in which a lower portion of an air box is provided in a space between cylinder heads arranged in front and rear in a V-type engine, the lower portion of the air box is surrounded by a cylinder head, a head cover, and a side cover of the air box. ing.

  At the three-surface intersection where the joint surfaces of these parts intersect, there is a step between the parts during assembly due to the processing accuracy and assembly accuracy of each part, or during expansion / contraction due to heat, during assembly, or during operation Each component may be deformed by the generated stress. There is a case where gaps are formed between the respective parts due to steps or deformations between these parts, and the air in the air box leaks out and the introduced air cannot be efficiently sucked into the engine.

  There are also three crossing portions in other parts of the engine, and there is a problem that engine oil, cooling water, and the like leak out at the three crossing portions.

  On the other hand, in Patent Document 1, a liquid seal member (liquid gasket) applied to the seal groove and the receiving groove is inserted into the receiving groove that communicates with the seal groove of the front cover. A seal structure is disclosed in which a gap is filled by using this to seal a three-surface intersection (three-surface mating portion) of a cylinder head, a cylinder block, and a front cover.

JP-A-11-336907

  However, the liquid seal member used in the seal structure described in Patent Document 1 is easily affected by oil, moisture, dust, and the like on the application surface (joint surface), and requires time for curing.

  If the liquid seal member is incompletely cured, the seal may be interrupted by vibrations during vehicle operation or pressure fluctuations in the front cover, etc., or broken pieces of the seal member may be mixed into engine oil or cooling water. There is a risk of malfunction.

  Even when the liquid seal member is completely cured, if the joint surfaces of the cylinder head, the cylinder block, and the front cover are greatly displaced relative to each other, the liquid seal member cannot follow the displacement. Seal may be incomplete.

  Furthermore, during the maintenance of the engine, it is necessary to remove the hardened liquid seal member. However, this removal is difficult, and there is a possibility that fragments of the removed seal member are mixed into the engine oil or cooling water.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an engine seal structure capable of improving the reliability of engine sealability and improving engine maintainability in consideration of the above-described circumstances.

  The present invention provides an engine seal structure in which a plurality of engine cases are joined to each other to seal a fluid inside the engine, and the first engine case and the second engine case are joined together. A third engine case and a third engine case that joins the first engine case and the second engine case intersect each other with a three-surface intersecting portion, and the joint surface of the first engine case and the second engine surface A main seal member made of an elastic material interposed between the joint surface of the engine case and an elastic material interposed between the joint surface of the third engine case and the first engine case and the second engine case. A sub seal member comprising: the main seal member and the sub seal member abutting each other; and Is shall.

  According to the present invention, since the main seal member and the sub seal member are made of an elastic material, unlike the liquid seal member, each of the joint surfaces of the first engine case, the second engine case, and the third engine case is in a state of being joined. Not affected. Furthermore, since the main seal member is configured to abut against the sub-seal member, even if the joint surfaces of the first engine case, the second engine case, and the third engine case are greatly displaced relative to each other, There is no loss of sealing performance. As a result, the reliability of the sealing performance of the engine can be enhanced even at the three-surface intersection where the respective joint surfaces of the first, second, and third engine cases intersect.

  Further, by removing the first engine case, the second engine case, and the third engine case, the main seal member and the sub seal member can be easily attached and detached, so that the maintainability of the engine can be improved.

1 is a left side view showing an engine and an air box to which an embodiment of an engine seal structure according to the present invention is applied. The perspective view which shows the inner side of the side cover in the air box of FIG. The perspective view which expands and shows the 3 surface crossing part X of FIG. The top view which shows the cylinder head of FIG. 1 with a gasket. The top view which shows the gasket of FIG. FIG. 2 is a rear view showing the head cover of FIG. 1. The rear view which shows the left side cover of FIG. The VIII arrow directional perspective view of FIG. 2 which removes and shows a left side cover. FIG. 3 is a perspective view showing a state in which the head cover of FIG. 2 is removed and the protruding end portion of the gasket and the seal molding are butted. Sectional drawing which follows the XX line of FIG.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a left side view showing an engine and an air box to which an embodiment of an engine seal structure according to the present invention is applied. FIG. 2 is a perspective view showing the inside of the side cover in the air box of FIG. In the present embodiment, expressions such as up / down, left / right, and front / rear are based on the driver when riding the vehicle.

  An engine 10 shown in FIG. 1 is a V-type engine (in this embodiment, a V-type four-cylinder engine) suspended on a body frame (not shown) of a motorcycle, and includes a front cylinder assembly 12F before and after a crankcase 11, and a rear side. The cylinder assembly 12R is arranged in a V shape. Specifically, cylinders 15 and 18 are integrally provided at the upper part of the upper half body 14 of the crankcase in the upper case (cylinder block) 13, and the cylinder head 16 and the head cover 17 are sequentially coupled to the cylinder 15. A cylinder assembly 12F is configured, and a cylinder head 19 and a head cover 20 are sequentially coupled to the cylinder 18 to form a rear cylinder assembly 12R. The lower half of the crankcase is formed on the lower surface of the upper crankcase 14 of the upper case 13. A crankcase 11 is configured by combining a certain lower case 21.

  A piston (not shown) moves up and down in the cylinders 15 and 18 of the upper case 13, and a crankshaft 22 connected to the piston is rotatably supported by the crankcase 11, and the cylinder head 16 and the head cover 17, and the cylinder head 19 and A valve operating device (not shown) is arranged in the head cover 20 to constitute the engine 10.

  The air box 23 is disposed above the engine 10 including the space between the front cylinder assembly 12F and the rear cylinder assembly 12R of the engine 10 thus configured. The air box 23 has an air box cover 25 mounted on the upper portion of the air box body 24 and a side cover 26 installed on the lower portion of the air box body 24, and an air duct 27 is connected to the air box body 24. A fuel supply device such as a fuel injection device (not shown) is disposed in the air box 23.

  A traveling wind (outside air) at the time of traveling of the vehicle is introduced into the air box 23 from the air duct 27, and this outside air (air) is mixed with fuel from the fuel supply device in the air box 23, and the cylinder head 16 in the engine 10. , 19 intake ports 28 (FIG. 2). Further, the exhaust gas from the engine 10 is discharged from the exhaust ports 29 (FIG. 1) of the cylinder heads 16 and 19 through an exhaust pipe (not shown).

  The upper portion of the air box 23 includes an air box body 24 and an air box cover 25. The lower portion of the air box 23 is a cylinder of the front cylinder assembly 22F as shown in FIGS. A side cover 26 is disposed between the head 16 and the head cover 17 and the cylinder head 19 and the head cover 20 of the rear cylinder assembly 22R, and the side cover 26 (the left side cover 30 and the right side cover 31) and the cylinder head 16 are arranged. 19 and the head covers 17 and 20 are joined together.

  Sealing members are interposed on the joint surfaces of the members constituting the air box 23 so that fluid (air mixture, air, etc.) in the air box 23 does not leak to the outside, and in the cylinder head 16 and the head cover 17. The fluid in the cylinder head 19 and the head cover 20 (engine oil or the like) is sealed so as not to leak into the air box 23.

  Among these, the seal structure of the cylinder heads 16 and 19 as the first engine case, the head covers 17 and 20 as the second engine case, and the left side cover 30 as the third engine case will be described below.

  The joint surface 30A of the left side cover 30 joined to the cylinder head 16 and the head cover 17 intersects with the joint surface 16A of the cylinder head 16 and the joint surface 17A of the head cover 17 that are joined together. Is formed. Similarly, the joint surface 30 of the left side cover 30 joined to the cylinder head 19 and the head cover 20 intersects with the joint surface 19A of the cylinder head 19 and the joint surface 20A of the head cover 20 which are joined to each other. An intersection Y is formed.

  That is, as shown in FIGS. 4 and 6, the three-plane crossing portion X also shown in FIG. 3 is such that the cylinder head 16 and the head cover 17 extend toward the joining surface 30 </ b> A side of the left side cover 30. The joining surface 16A of the cylinder head extension portion 32 and the joining surface 17A of the head cover extension portion 33 of the head cover 17 are joined together, and the mating surface 32A orthogonal to the joining surface 16A of the cylinder head extension portion 32 and the head cover The mating surface 33A orthogonal to the joint surface 17A of the extended portion 33 is joined to the joint surface 30A of the left side cover 30.

  Similarly, as shown in FIG. 2, the three-plane intersecting portion Y is such that the cylinder head 19 and the head cover 20 extend to the joining surface 30 </ b> A side of the left side cover 30, and the cylinder head extending portion 34 of these cylinder heads 19. The joining surface 19A of the head cover 20 and the joining surface 20A of the head cover extending portion 35 of the head cover 20 are joined together, the mating surface 34A orthogonal to the joining surface 19A of the cylinder head extending portion 34, and the joining surface of the head cover extending portion 35 The mating surface 35A perpendicular to 20A is joined to the joining surface 30A of the left side cover 30.

  Since these three-plane crossing portions X and Y are the same, the seal structure of the three-plane crossing portion X will be described in detail with reference to FIGS.

  A gasket 36 as a main seal member shown in FIGS. 4 and 5 is interposed between the joining surface 16A of the cylinder head 16 shown in FIG. 4 and the joining surface 17A of the head cover 17 shown in FIG. The gasket 36 includes a gasket body 36A formed in a ring shape corresponding to the shapes of the joint surface 16A of the cylinder head 16 and the joint surface 17A of the head cover 17, and the shapes of the cylinder head extension portion 32 and the head cover extension portion 33. And a gasket extending portion 36B formed in a substantially linear shape corresponding to the above. As shown in FIGS. 8 and 9, the gasket 36 composed of the gasket main body 36 </ b> A and the gasket extending portion 36 </ b> B is provided in a convex shape having a reverse T-shaped cross section, and the convex portion 38 of the gasket 36 is the head cover 17. Is inserted into a seal groove 39 (FIG. 6) formed on the joint surface 17A.

  Accordingly, the gasket main body 36A of the gasket 36 is interposed between the joining surface 16A of the cylinder head 16 (excluding the cylinder head extending portion 32) and the joining surface 17A of the head cover 17 (excluding the head cover extending portion 33). At the same time, the gasket extending portion 36B of the gasket 36 is continuously interposed between the joining surface 16A of the cylinder head extending portion 32 and the joining surface 17A of the head cover extending portion 33 without being interrupted, The cylinder head 16 (including the cylinder head extension portion 32) and the head cover 17 (including the head cover extension portion 33) are hermetically sealed.

  Further, as shown in FIG. 7, a seal groove 40 is formed in the joint surface 30A of the left side cover 30, and a seal molding 41 as a sub seal member is inserted into the seal groove 40 as shown in FIGS. The The seal molding 41 includes a joining surface 30A of the left side cover 30, a mating surface 32A of the cylinder head extension portion 32, a mating surface 33A of the head cover extension portion 33, a mating surface 34A of the cylinder head extension portion 34, and a head cover extension. It is interposed between the mating surface 35A of the installation portion 35 and the joint surface (not shown) of the upper case 13, and seals between these members.

  The gasket 36 and the seal molding 41 are configured such that one of the hardnesses is greater than the other hardness. In the present embodiment, the gasket 36 is made of an elastic material such as acrylic rubber, the seal molding 41 is made of an elastic material such as sponge, and the hardness of the gasket 36 is larger than the hardness of the seal molding 41. ing.

  Further, the gasket extending portion 36B of the gasket 36 is interposed between the cylinder head extending portion 32 and the head cover extending portion 33, as shown in FIG. 32A and the head cover extending portion 33 are provided so as to protrude from the mating surface 33A to the joining surface 30A side of the left side cover 30 to form a protruding end portion 42. When the left side cover 30 is attached to the cylinder heads 16 and 19 and the head covers 17 and 20, the projecting end of the gasket extending portion 36B of the gasket 36 interposed between the cylinder head extending portion 32 and the head cover extending portion 33 is provided. As shown in FIG. 9, the portion 42 is pressed against the seal molding 41 in the seal groove 40 of the left side cover 30 in a pressed state.

  At this time, the width W (FIG. 5) of the convex portion 38 of the projecting end portion 42 in the gasket extending portion 36 </ b> B of the gasket 36 is set to a dimension equal to or smaller than the groove width M of the seal groove 40 in the joint surface 30 </ b> A of the left side cover 30. In addition, since the hardness of the gasket 36 is larger than the hardness of the seal molding 41 as described above, when the projecting end portion 42 of the gasket extension portion 36B is pressed against the seal molding 41 in a pressed state, The protruding portion 38 of the protruding end portion 42 is embedded in the seal molding 41 as shown in FIG. In this way, the seal structure of the three-plane intersection X is configured.

  As shown in FIG. 5, the width W of the convex portion 38 of the gasket 36 is not limited to the convex portion 38 of the projecting end portion 42, but also the convex portion 38 of the gasket main body 36A and the gasket extending portion 36B. Dimensions.

  With the configuration as described above, the following effects (1) to (5) are achieved according to the present embodiment.

  (1) As shown in FIG. 2, the gasket 36 interposed between the joint surface 16A of the cylinder head 16 and the joint surface 17A of the head cover 17, the mating surface 32A of the cylinder head extension portion 32 of the cylinder head 16, and the head cover 17 The seal molding 41 (FIG. 3) interposed between the mating surface 33A of the head cover extending portion 33 and the joint surface 30A of the left side cover 30 is made of an elastic material. Therefore, the gasket 36 and the seal molding 41 are different from the liquid seal member in that the joining surface 16A and the mating surface 32A of the cylinder head 16, the joining surface 17A and the mating surface 33A of the head cover 17, and the joining surface 30A of the left side cover 30 are provided. It is not affected by the condition (for example, the presence of oil, moisture, or dust).

  Further, as shown in FIGS. 8 and 9, the protruding end portion 42 of the gasket extending portion 36 </ b> B of the gasket 36 is pressed against the seal molding 41 in the seal groove 40 on the joint surface 30 </ b> A of the left side cover 30 in a pressed state. Has been configured. For this reason, even when the joint surface 16A and the mating surface 32A of the cylinder head 16, the joint surface 17A and the mating surface 33A of the head cover 17, and the joint surface 30A of the left side cover 30 are greatly displaced, these joint surfaces and mating surfaces. The sealing performance is not impaired.

  As a result, as shown in FIG. 3, the three-surface intersection X where the joint surface 16A and the mating surface 32A of the cylinder head 16, the joint surface 17A and the mating surface 33A of the head cover 17, and the joint surface 30A of the left side cover 30 intersect. In this case, the reliability of the sealing performance of the engine 10 can be improved.

  (2) By removing the cylinder head 16, the head cover 17, and the left side cover 30, the gasket 36 and the seal molding 41 can be easily attached and detached, so that it is difficult to remove the cured liquid seal member, The maintainability of the engine 10 can be improved.

  (3) As shown in FIGS. 3 and 9, a gasket 36 interposed between the cylinder head 16 and the head cover 17, and a seal molding 41 interposed between the left side cover 30, the cylinder head 16 and the head cover 17, Since both are made of an elastic material and have low rigidity, the cylinder head 16, the head cover 17, and the left side cover can be used even when the projecting end portion 42 of the gasket extending portion 36 </ b> B of the gasket 36 is pressed against the seal molding 41. Tightening during assembly of 30 is not hindered.

  (4) The width W of the convex portion 38 of the gasket 36 interposed between the cylinder head 16 and the head cover 17 is set to a dimension equal to or smaller than the groove width M of the seal groove 40 in the joint surface 30A of the left side cover 30 and the gasket. The hardness of 36 is configured to be greater than the hardness of the seal molding 41 inserted into the seal groove 40. Therefore, with the gasket 16, the cylinder head 17 and the left side cover 30 assembled, the projecting end portion 42 in the gasket extension portion 36B of the gasket 36 can be abutted in the seal molding 41, The sealing performance of the three-plane intersection X can be further improved.

  (5) Between the joint surface 16A of the cylinder head extension portion 32 of the cylinder head 16 and the joint surface 17A of the head cover extension portion 33 of the head cover 17, the gasket extension portion 36B of the gasket 36 is cut off halfway. Therefore, the sealing performance between the cylinder head extension portion 32 and the head cover extension portion 33 can be improved.

  The above-mentioned effects (1) to (5) are effects on the sealing of the joining surface and the mating surface including the cylinder head 16 and the head cover 17 and the left side cover 30 of the front cylinder assembly 12F including the three-surface intersection X. However, the same effect can be obtained with respect to the sealing of the joining surface and the mating surface including the cylinder head 19 of the rear cylinder assembly 12R and the three-surface intersection Y between the head cover 20 and the left side cover 30.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this. For example, a three-surface intersection is formed on each joint surface of the upper case (cylinder block) 13, the cylinder heads 16 and 19, and the chain case that is disposed on these side portions and forms a cam chain chamber. The present invention may also be applied to such other three-surface intersections to prevent leakage of engine oil or cooling water.

10 Engine 16 Cylinder head (first engine case)
16A Joint surface 17 Head cover (second engine case)
17A Joint surface 23 Air box 26 Side cover 30 Left side cover (third engine case)
30A Joint surface 32 Cylinder head extension portion 32A Matching surface 33 Head cover extension portion 33A Matching surface 36 Gasket (main seal member)
36B Gasket extension 38 Projection 40 Seal groove 41 Seal molding (Sub seal member)
X, Y 3 plane intersection W width M groove width

Claims (6)

In an engine seal structure in which a plurality of engine cases are joined to each other to seal a fluid inside the engine,
The joint surfaces of the third engine case joined to the first engine case and the second engine case intersect with the joint surfaces of the two engine cases joined to the first engine case and the second engine case. It has a three-plane intersection,
A main seal member made of an elastic material interposed between the joint surface of the first engine case and the joint surface of the second engine case;
A sub-seal member made of an elastic material interposed between the joint surface of the third engine case and the first engine case and the second engine case;
An engine seal structure characterized in that the main seal member and the sub seal member are abutted against each other. 2. The engine seal structure according to claim 1, wherein the main seal member and the sub seal member are configured such that one of the main seal members and the sub seal member has a hardness greater than the other. The main seal member is provided so as to protrude toward the joint surface side of the third engine case, and a protruding end portion of the main seal member is abutted against the sub seal member in a pressed state. 2. The engine seal structure according to 1. A cross section of a protruding end portion where the main seal member protrudes to the joining surface side of the third engine case is formed in a convex shape, and the width of the protruding portion of the protruding end portion is formed on the joining surface of the third engine case. 2. The engine seal structure according to claim 1, wherein the seal structure is set to a dimension equal to or smaller than a width of a seal groove that accommodates the sub seal member. The first engine case is a cylinder head of a V-type engine, the second engine case is a head cover placed on the cylinder head, and the third engine case is disposed between the pair of cylinder heads. 2. The engine seal structure according to claim 1, wherein the engine seal structure is a side cover of an air box. The cylinder head and the head cover are extended to the joint surface side of the side cover, and a part of the main seal member is continuously interposed between the extended portion of the cylinder head and the extended portion of the head cover. The engine seal structure according to claim 5, wherein the engine seal structure is provided.

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