JP3788546B2 - Intake cover device for overhead camshaft engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake cover device that covers a side surface of an overhead camshaft engine in which one end opening of an intake port is formed.
[0002]
[Prior art]
In a general engine, a cover such as a water pump cover, an ACG cover, and a clutch cover such as a water pump cover, an ACG cover, and a clutch cover is covered and sealed with a single cover that is formed separately for each place that needs to be sealed. For example, in Japanese Patent Publication No. 6-102966, exhaust gas, lubricating oil, and cooling water are sealed to the bottom surface of the crankcase by using different covers and different planes of joint surfaces.
[0003]
[Problems to be solved by the invention]
In the above conventional example, a cover is required for each medium to be sealed, and the bolting work must be performed separately, so the number of parts is increased for the individual cover and the fastening bolt used for each, In addition, the manufacturing man-hours and work man-hours for manufacturing the cover and the joint surface of the engine increase.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a first invention relating to an intake cover device for an overhead camshaft engine according to the present invention is an overhead camshaft engine in which an engine camshaft is provided above a cylinder head. thereby extending axially alongside an end of the cam shaft and the one end opening to the engine one aspect, cam shaft cover that covers the intake manifold to be attached, the end face of the cam shaft continuously to the intake ports part provided an intake cover formed integrally with, covering the side intake ports of the engine is opened by the intake cover Utotomoni,
The intake manifold and the camshaft cover portion are formed on the same plane with each joint surface with the side surface of the engine.
One end of the cam shaft is covered with the cam shaft cover portion, and a cam shaft drive transmission member is provided on the other end side .
[0005]
According to a second invention, in the first invention, an oil passage for guiding lubricating oil to the camshaft end is integrally formed in the intake cover.
[0006]
According to a third invention, in the first invention, the intake passage of the intake manifold is bent along a plane parallel to a joint portion between the intake cover and the engine.
[0007]
According to a fourth invention, in the first invention, a water jacket is opened on the side surface of the engine where the intake port opens, and a water jacket cover portion for covering the opening of the water jacket is formed integrally with the intake cover. It is characterized by that.
[0008]
According to a fifth aspect, in the fourth aspect, the intake port, the camshaft end portion, and the water jacket opening are arranged side by side on the same plane to one side of the engine, and the intake manifold of the intake cover, the camshaft cover The joint surfaces of the part and the water jacket cover part are also formed on the same plane.
[0009]
【The invention's effect】
According to the first aspect of the present invention, the intake manifold formed integrally with the intake manifold and the camshaft cover that covers the end surface of the camshaft covers the side surface where the engine intake port is opened. Two media, gas and oil, can be sealed simultaneously. In addition, since the intake manifold and the camshaft cover can be integrated, the number of parts can be reduced, and the number of manufacturing steps for the cover and the joint surface of the engine and the number of steps for attaching the cover can be reduced. In addition, if the joint surface of the air intake cover is formed by die casting the engine and is sealed using an O-ring, the seal portion can be made completely unprocessed.
[0010]
According to the second invention, since the oil passage for guiding the lubricating oil to the camshaft end portion is formed integrally with the intake cover, the oil passage can be easily formed.
[0011]
According to the third invention, since the intake passage of the intake manifold is bent along a plane parallel to the joint portion between the intake cover and the engine, the directionality when connecting to the carburetor is reduced. The degree of freedom in the layout of the vaporizer increases.
[0012]
According to the fourth aspect of the invention, the water jacket cover portion is formed integrally with the intake cover, so that the three mediums of the gas mixture, the oil, and the cooling water can be sealed simultaneously with one intake cover. In addition, the effects of reducing the number of parts, the number of processing steps, and the number of work steps become even more remarkable.
[0013]
According to the fifth aspect of the invention, since the joint surfaces on the engine side and the intake cover side for these three media are formed on the same plane, the number of processing steps can be reduced. Furthermore, simplification of the seal can be achieved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment applied to a water-cooled four-cycle small displacement engine for small motorcycles will be described with reference to the drawings. 1 is an overall cross-sectional view of the engine according to the present embodiment, FIG. 2 is a view showing a right side of the main body with the inlet cover removed, FIG. 3 is a cross-sectional view taken along line 1-1 of FIG. 1, and FIG. FIG. 5 is a view showing a joint surface side of the inlet cover with respect to the right side surface of the main body.
[0015]
This engine has a substantially rectangular parallelepiped main body 1 formed of a suitable metal such as an aluminum alloy by a casting method such as die casting, and the like, and an inlet cover 2 and two substantially opposite sides formed in the longitudinal direction. The cam chain cover 3 is assembled and attached to a crankcase (not shown).
[0016]
In the main body 1, a cylinder portion 5 that accommodates a piston 4 connected to a crankshaft (not shown) via a connecting rod 4a and a head portion 8 having a cam chamber 7 that rotatably accommodates a camshaft 6 are integrated. It is formed by casting.
[0017]
In the present application, the portion of the head portion 8 that covers the cam chamber 7 is particularly the head cover portion 9, and for convenience, the surface on which the inlet cover 2 is attached is attached to the right side surface 10 and the cam chain cover 3 for each surface of the main body 1. The surface to be mounted is referred to as the left side surface 11 (FIG. 4), the surface to which a later-described radiator is attached among the two opposing surfaces sandwiched between these surfaces is referred to as the front surface 12, and the other is referred to as the back surface 13 (FIG. 3). Further, the outer surface of the ceiling portion of the head cover portion 9 is a top surface 14, and the surface attached to the crankcase is a bottom surface 15.
[0018]
In the cylinder portion 5, a cylinder 16 is formed from the bottom surface 15 side to a substantially intermediate portion in the length direction of the main body 1, and a combustion chamber 17 formed on the head portion 8 side which is the innermost portion of the cylinder 16 includes an intake port 18 and The exhaust port 19 communicates with each other and the opening on the combustion chamber 17 side of each port is opened and closed by an intake valve 20 and an exhaust valve 21, and each valve axis C 1, C 2 forms a predetermined valve sandwich angle with respect to the cylinder axis C. Yes. Reference numerals 20a and 21a are stem holders.
[0019]
The intake port 18 communicates with an intake passage 22 formed in the inlet cover 2, and the intake passage 22 extends obliquely outwardly on the extension of the intake port 18 and is connected to a carburetor (not shown) via the inlet pipe 23. It is connected. The exhaust port 21 bends and extends in a direction substantially perpendicular to the intake port 18 and is connected to the exhaust pipe 24 on the back surface 13. Reference numeral 29 in FIGS. 2 and 3 denotes a spark plug.
[0020]
As shown in FIG. 3, each valve is driven directly by a cam 27, 28 via a valve lifter 25, 26 provided at the end of each shaft. , 28 is supported by bearings 30 and 31 at both open end portions of the cam chamber 7 which is formed in a tapered shape so as to penetrate between the right side surface 10 and the left side surface 11. The sliding surfaces of the cams 27 and 28 are inclined surfaces corresponding to the sliding surfaces of the valve lifters 25 and 26, respectively.
[0021]
As shown in FIG. 4, valve lifter holes 80 and 81 for accommodating the valve lifters 25 and 26 are formed in the head portion 8 of the main body 1, and as shown in FIG. 1, these holes extend along the valve axis C1 or C2. The extension of each valve axis C1 or C2 extends so as to intersect with the axis of the camshaft 6 (the central axis of the cam chamber), and cam viewing holes 36 and 37 are formed in the head cover portion 9 on the extension.
[0022]
The other end side of the cam shaft 6 protrudes into a chain chamber 32 formed between the cam chain cover 3 and the left side surface 11, and a cam sprocket 33 is attached to the protruding end portion with a bolt 34. This cam sprocket 33 is wound around a drive sprocket provided on a crankshaft (not shown) via a cam chain 35.
[0023]
On the extension of the valve axis lines C1 and C2 in the head cover portion 9, cam peep holes 36 and 37 that are coaxial with the valve axis lines C1 and C2 and have the same diameter as the valve lifters 25 and 26 are formed. Caps 38 and 39 for opening and closing the cam chamber 7 are sealed with screws through seals.
[0024]
In the vicinity of the combustion chamber 17 of the main body 1, a water pump 40 is accommodated in a circular pump mounting recess 41 formed on a side wall facing the cam chain cover 3 of the main body 1, and a resin cover that forms the outer shape of the water pump 40. By sealing the outer periphery of the flange 42 formed in a part of the flange 42 in a liquid-tight manner via the O-ring 44, the pump mounting recess 41 is sealed.
[0025]
The pump body 43 covers a water jacket 45 partially opened in the pump mounting recess 41, and an impeller 46 is disposed at the center of the pump body 43 and is supported so as to be integrally rotatable with the pump shaft 47. Cooling water is taken in from a water passage 43a that is directly open to the water jacket 45 at the part.
[0026]
One end of the pump shaft 47 is rotatably supported by a boss 48 formed to protrude from the outer peripheral wall surface of the cylinder 16. The other end side of the pump shaft 47 protrudes into the chain chamber 32 beyond the cam chain 35, a magnet ring 49 is provided around the cam shaft 35, and a part of the resin cover integrated with the flange 42 is formed in a circle around the magnet ring 49. The small diameter portion 50 is formed by covering. The protruding end of the small diameter portion 50 is fitted and supported in a circular fitting recess 51 formed in the cam chain cover 3.
[0027]
A water pump sprocket 53 in which a magnet ring 52 is integrated on the inner peripheral side is provided on the outer peripheral portion of the small diameter portion 50 and is driven by a cam chain 35. The outer periphery of the boss of the water pump sprocket 53 is rotatably accommodated in a circular water pump accommodating portion 55 formed on the cam chain cover 3 via a bearing 54.
[0028]
When the magnet ring 52 rotates integrally with the water pump sprocket 53, the magnet ring 49 in the small diameter portion 50 is magnetically coupled and rotated integrally, and thereby the impeller is connected via the pump shaft 47 integral with the magnet ring 49. 46 is rotated, and the water pump 40 is driven. The water pump 40 forcibly circulates cooling water to the water jacket 45 on the inlet cover 2 side via a radiator 56 (FIG. 1) provided on the front surface 12 of the main body 1.
[0029]
As shown in FIG. 5, the inlet cover 2 corresponds to the intake cover of the present invention, and is a member in which an intake manifold 60 camshaft cover portion 62 and a water jacket cover portion 67 are integrally formed. First, on the joint surface side of the inlet cover 2 attached to the right side surface 10 of the main body 1, an elliptical intake seal 61 that surrounds the opening end portion of the intake passage 22 in the central intake manifold 60, and a cam shaft above the intake seal 61. Cam shaft end seals 63 are formed so as to surround the cover portion 62 in a substantially circular shape.
[0030]
Further, an oil passage seal 64 is formed which extends continuously from the camshaft end seal 63 and extends obliquely downward in the figure, and then extends along the edge of the inlet cover 2 to the lower end portion. It is a seal.
[0031]
An oil passage 65 is connected to the communication passage 66 at the lower end corner from the camshaft cover portion 62 along the oil passage seal 64. The camshaft end seal 63 and the oil passage seal 64 are connected to the camshaft cover portion 62. The oil passage 65 and the oil passage connection recess 66 are continuously formed around the periphery.
[0032]
A portion of the inlet cover 2 except the oil passage seal 64 below the intake manifold 60 constitutes a water jacket cover portion 67, and the periphery thereof is surrounded by a substantially rectangular cooling water seal 68.
[0033]
On the other hand, as shown in FIG. 2, the right side surface 10 of the main body 1 covered by the inlet cover 2 corresponds to each seal of the inlet cover 2, and an intake seal joint surface 71 surrounding the periphery of the intake port 18, bearings 30 is a cam shaft end seal joint surface 73 that surrounds 30, an oil passage seal joint surface 74 that connects the end of the cam shaft 6 and the oil passage 76 at the lower right corner of the right side, and a cooling water seal 68 are openings in the water jacket 45. A cooling water seal joint surface 78 is formed so as to surround 49.
[0034]
The oil passage 76 is connected to an oil passage connecting recess 66 at one end, and the other end is connected to an oil pump (not shown) to an oil supply portion 6a (FIG. 3) formed at the shaft end of the camshaft 6 via the oil passage 65. Lubricating oil is supplied.
[0035]
Next, the operation of this embodiment will be described. When the inlet cover 2 is put on the right side surface 10 of the main body 1, the intake seal 61 surrounds the periphery of the intake port 18 and is airtightly connected to the intake seal joint surface 71, and the cam shaft end seal 63 surrounds the periphery of the bearing 30. The oil passage seal 64 surrounds the oil passage 65 and is liquid tightly joined to the oil passage seal joint surface 74, and the cooling water seal 68 is connected to the water jacket 45. It surrounds the periphery of the opening 49 and is liquid-tightly joined to the cooling water seal joint surface 78.
[0036]
As a result, the single medium of the mixed gas, oil, and cooling water can be sealed at the same time with a single inlet cover 2. Moreover, since the intake manifold 60, the camshaft cover portion 62, and the water jacket cover portion 67 can be integrated, the number of parts can be reduced, and the number of man-hours for manufacturing the cover and the engine joint surface and the number of work steps for attaching the cover are also increased. Each will be less.
[0037]
In addition, by joining the main body 1 by die-casting, the joint surface of the inlet cover 2 can be formed almost without machining, and if each seal part is sealed using a 0-ring, the seal part can even be completely machined. Is also possible.
[0038]
In addition, since the joint surfaces of the main body 1 and the inlet cover 2 for the three media are formed on the same plane, a seal portion can be easily formed, and each of the three media can be reliably sealed even at the same time. Can be sealed.
[0039]
In addition, since the oil passage 65 for guiding the lubricating oil to the inlet cover 2 to the camshaft end portion is formed by the oil passage seal 64, the oil passage 65 can be easily formed.
[0040]
Furthermore, since the intake passage 22 of the intake manifold 60 is bent along a plane parallel to the right side surface 10 of the main body 1 that is a joint portion with the inlet cover 2, the directionality when connecting to the carburetor is reduced. The degree of freedom in the layout of the engine and the carburetor is increased.
[0041]
The present invention is not limited to the above-described embodiments and can be variously modified. For example, it is sufficient to integrate at least the intake manifold 60 and the camshaft cover portion 62 with the inlet cover 2, and the water jacket cover. The part 67 and the oil passage 65 may be provided separately. Also, the casting method is not necessarily aluminum die casting, and other known casting methods such as using a sand mold can be adopted. Further, it may be a DOHC engine.
[Brief description of the drawings]
1 is an overall cross-sectional view of an engine according to the present embodiment. FIG. 2 is a view showing a right side surface after removing an inlet cover. FIG. 3 is an enlarged cross-sectional view taken along line 3-3 in FIG. Sectional view [Fig. 5] Diagram showing the joint surface side of the inlet cover [Explanation of symbols]
1: Main body, 2: Inlet cover (intake cover), 3: Cam chain cover, 6: Cam shaft, 7: Cam chamber, 8: Head portion, 9: Head cover portion, 16: Cylinder, 18: Intake port, 25 · 26: valve lifter, 27/28: cam, 60: intake manifold, 61: intake seal, 62: camshaft cover, 63: camshaft end seal, 64: oil passage seal, 65: oil passage, 67: water jacket Cover part, 68: Cooling water seal

Claims (5)

In overhead camshaft type engine having a cam shaft of the engine above the cylinder head, an intake port alongside an end of the cam shaft and the one end opening to the engine one side and is extended to the cam axis, an intake manifold mounted in succession in the intake port, the provided suction cover integrally formed with the cam shaft cover portion that covers the end face of the camshaft, it covering the side intake ports of the engine is opened by the intake cover With
The intake manifold and the camshaft cover portion are formed on the same plane with each joint surface with the side surface of the engine.
An intake cover device for an overhead camshaft engine, wherein one end of the camshaft is covered with the camshaft cover portion and a camshaft drive transmission member is provided on the other end side .   The intake cover device for an overhead camshaft engine according to claim 1, wherein an oil passage for guiding lubricating oil to the camshaft end portion is formed integrally with the intake cover.   The intake cover of an overhead camshaft engine according to claim 1, wherein the intake passage of the intake manifold is bent along a plane parallel to a joint portion between the intake cover and the engine. apparatus.   A water jacket is opened on the side surface of the engine where the intake port opens, and a water jacket cover portion for covering the opening of the water jacket is formed integrally with the intake cover. The intake cover device for an overhead camshaft engine according to the item.   The intake port, camshaft end, and water jacket opening are arranged on the same plane on the same side of the engine, and the joint surfaces of the intake manifold, camshaft cover, and water jacket cover are the same. 5. The intake cover device for an overhead camshaft engine according to claim 4, wherein the intake cover device is formed on a flat plane.

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