JP3521727B2 - Oil passage structure of motorcycle engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil passage structure for a motorcycle engine, in which oil used for cooling / lubrication of the motorcycle engine is made to flow down to an oil pan.

[0002]

2. Description of the Related Art As is well known, an engine for a motorcycle is supplied with oil for the purpose of lubrication and cooling for various sliding parts such as cylinders and overheated parts.
In a 4-cycle engine, oil is supplied from an oil pan stored below the crankcase to an oil pump by an oil pump. The oil sent to each part flows down to the oil pan as appropriate. The oil stored in the oil pan is purified through a strainer, an oil filter, and the like, and then again provided for lubrication and cooling of each part.

Further, in the oil feeding system in which the oil is fed by using the oil pump as described above, a relief valve is provided in the oil feeding path,
When the oil pressure exceeds a certain value, the relief valve ejects oil from the nozzle to prevent the oil pressure from becoming excessive. Then, the oil discharged from the relief valve scatters to the surroundings, and finally flows down to the oil pan, is stored, and is again used for lubrication and cooling.

[0004]

As described above, in the engine of the motorcycle, the oil sent to each part and the oil discharged from the relief valve are respectively returned to the oil pan. However, if the oil flow path to the oil pan is not set at all and allowed to flow naturally by its own weight, the oil hits the rotating body such as the crank wheel or transmission gear and causes mechanical loss. However, there is an inconvenience such as an increase in oil temperature. For this reason, conventionally, by providing a wall surface around the relief valve to prevent oil from splashing around, and by installing a vertical wall or an iron plate inside the engine case, oil pans can be removed from each part that requires lubrication and cooling. It has been proposed and practiced to form a reflux flow passage over the entire length and to guide the oil from each part to the oil pan in the reflux flow passage. However, when a vertical wall, an iron plate, or the like is provided in the engine case, the interior of the engine case becomes complicated, the internal space of the engine case is reduced, and the number of parts increases, which causes a cost increase. Occurred.

The present invention has been made in view of the above problems, and it is possible to return oil to an oil pan while preventing the oil from being scattered to unnecessary portions in the engine case, and An object of the present invention is to provide an oil passage structure for a motorcycle engine that can maintain a space and prevent an increase in the number of parts.

[0006]

The present invention has the following constitution in order to solve the above problems. That is, the present invention is an oil passage structure for an engine, in which the cooling / lubricating oil supplied to a required location in an engine case forming an outer shell of the engine is caused to flow down to an oil pan, A relief valve chamber for accommodating a relief valve is defined inside the engine case, and a relief valve chamber is provided below the partition wall of the relief valve chamber, facing the oil pan at the bottom of the engine case.
Only by forming a discharge port for discharging oil out of the engine case and cover that is joined to the side edge, as well as provides the oil return passage to form a groove on at least one of the bonding surfaces, the Openings are formed at both ends of the oil return passage, and one of the openings is used as an inflow port for inflowing the oil discharged from a required location in the engine case, while the other opening is communicated with the relief valve chamber. It serves as an outlet.

[0007] Then, according to the present invention having the above structure, the oil supplied to the portion requiring lubrication and cooling of the engine case, the oil from the inlet port formed in the groove
The relief valve chamber flows into the return passage and flows out from the outlet.
Enters and flows out to the oil pan for storage. Therefore, oil does not scatter and hit the rotating body in the engine case, mechanical loss of the rotating body does not occur, and the oil temperature does not rise, and proper oil feeding operation is realized. can do. Moreover, since the concave groove is formed on the joint surface of the engine case, the internal space of the engine case is not reduced or complicated. In addition, the oil released from the relief valve
It is possible to prevent it from scattering around,
The oil flowing out of the outlet of the flow channel also scatters around
Since it can be blocked by the partition wall, oil can be more reliably
Prevents temperature rise and mechanical loss
it can.

Further, the engine casing is provided with a crankcase comprising engages against the pair of right and left crank case components, the concave hand of crankcase components
While forming the groove, the left and right crankcase components
Each shatterproof wall is formed on the inner surface, and these shatterproof walls
The relief valve chamber may be configured by joining together , and according to this, the shatterproof wall is provided on the left and right crankcases.
Since it is provided on the inner surface of the constituent member , the crankcase constituent member does not become particularly complicated.

[0009]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 is a side view showing a motorcycle to which an embodiment of the present invention is applied, FIG. 2 is a right side view showing an overall configuration of an engine case in FIG. 1, and FIGS. 3 to 10 are diagrams showing the engine case shown in FIG. FIG. 11 and FIG. 12 are views showing the structure of a crankcase that is used, and FIG. 11 and FIG. 12 are views showing a clutch cover joined to the crankcase.

The motorcycle 1 shown in FIG. 1 is a road sports type motorcycle, and the skeleton of the vehicle body is composed of a diamond frame 2. And in the head pipe 2a located at the front end of the frame 2,
The steering 4 is rotatably supported around the steering stem, and a front fork 6 that rotatably supports the front wheels 5 is held. The front fork 6 and the front portion of the vehicle body such as the steering stem are It is covered by a cowling 9 equipped with a light 7 and a direction indicator 8. Further, a swing arm 11 is swingably held by a pivot 2c and a cushion unit on a pivot plate portion 2b of the diamond frame 2, and a rear wheel 12 is provided on a rear end portion of the swing arm 11.
Is rotatably supported. Further, a V-type 2-cylinder engine 20 is suspended on the diamond frame 2, a tank 13 is supported above the diamond frame 2 by an upper tube 2d of the diamond frame 2, and a rear portion of the diamond frame 2 is formed behind the tank 13. The seat 14 is held by the seat rail 2e.

The engine case 21 forming the outer shell of the engine 20 is constructed as follows. That is, the engine case 21 shown here, crankcase
And a pair of front and rear cylinders 25, 2 fixed and fixed to this
8, two cylinder heads 26 and 29 fixed to the upper end surfaces of the cylinders 25 and 28, respectively, and two cylinder head covers 27 and 30 fixed to the upper end portions of the cylinder heads 26 and 29, respectively. It is composed of and. Further, crankcase is left split type, as shown in FIG. 3, a right-side crankcase component 22 is configured by joining the left side crank case component 23 from the left and right direction, both the bottom of the crank <br/> cases formed by the crank case components 22 and 23, an oil pan 21a which stores lubricating and cooling oil is formed.

Further, both crankcase constituting members 2
2 and 23 have a structure as shown in FIGS. That is, through-holes 22a, 22b, 22 for inserting bearings for inserting a crank shaft, a drive shaft, a counter shaft, a gear shift shaft, etc. are inserted into both crank constituent members 22, 23.
c, 22d (see FIGS. 4 and 5), and 23a, 23
b, 23c, 23d (see FIG. 8) are formed,
Inner joint surfaces 22A, 22B for joining the respective crankcase constituent members 22, 23 to each other on the inner surface side thereof.
(See FIG. 5), 23A and 23B (see FIG. 8) are respectively formed. Further, the right and left crankcase constituent members 22 and 23 have arc-shaped edge portions 22e and 22f.
(See FIGS. 5 to 7), 23e and 23f (see FIGS. 8 to 10) are respectively formed at two front and rear positions.
Then, by joining the inner joint surfaces 22A, 22B of the right crankcase constituting member 22 and the inner joint surfaces 23A, 23B of the left crankcase constituting member 23 to each other, a storage space for accommodating the crankshaft, connecting rod, etc., And the oil pan 21a is formed,
The arc-shaped arc-shaped edge portions 22e and 23e, 22f and 2
3f are joined to each other, and the front and rear cylinders 25,
An arc-shaped opening communicating with 28 is formed.

On the other hand, a scattering prevention wall surrounding the clutch mechanism is formed on the outer surface side of the right crankcase constituting member 22, and an end surface (joint surface) 22D1 of this scattering prevention wall 22D is formed.
Is a clutch cover 40 as shown in FIG. 11 and FIG.
Are to be joined. The joint surface 22D1 of the right crankcase component 22 and the clutch cover 40
The joint surface 41 of the groove 22 as shown in FIGS. 4 and 12
E and 41E are formed, and both grooves 22E and 41E are formed at positions facing each other in a state where the clutch cover 40 is joined to the right crankcase constituent member 22, and both grooves 22E and 41E are opposed to each other. By combining them, the oil passage R2 having a substantially circular cross section is formed.

The oil passage R2 has a through hole 22E1 formed at the upper end of the groove 22E as an inflow port and a through hole 22E2 formed at the lower end as an outflow port, and the inflow port 22E1 extends from the cylinder head 26 to the cylinder. Communicating with the lower end of the oil return passage R1 (see FIG. 2) reaching 26,
The outlet 22E2 communicates with the relief valve chamber S that covers the periphery of the relief valve 32 from the right crankcase component 22 side. The relief valve chamber S
Includes a tubular right side scatter prevention wall 22C that protrudes so as to cover the relief valve 32 to the inner surface of the right-side crankcase component 22, the left side projecting from the inner surface of the left side crank case component 23 It has become those constituted by bonding the scattering prevention wall 23C, right side scatter prevention wall 2
2 C lower side portion of an opening, to form a discharge port 51 for discharging the oil towards the oil pan 21a.

Further, in FIGS. 3 to 5, reference numeral 34 denotes an oil pump for pumping the oil into the oil passage, and 35 denotes a strainer for filtering the oil sucked from the oil pan 21a by the oil pump 34. Although not particularly shown here, a groove is similarly formed on the joint surface between the left crankcase 23 and the magnet cover 50, and the oil passage formed by the combination of the groove is formed in the rear cylinder 28 and the cylinder head. The oil passage is provided at 29.

In the engine 20 having the oil passage structure configured as described above, when the engine 20 is driven, the oil pump is operated in association with the rotation of the crankshaft, and along the path shown by the arrow in FIG. Oil pan 2
The oil stored in 1a is sucked. The sucked oil is stored in a portion requiring lubrication / cooling, for example, a journal portion of a crankshaft, a sliding surface between a cylinder 25 and a piston, a cylinder head 26, and a cylinder head cover 27 via a path indicated by arrows in FIG. The oil that has been pressure-fed to the valve operating mechanism or the like and then supplied to each part cools and lubricates each part, and then flows down to the lower oil pan 21a.

At this time, the cylinder 25 and the cylinder head 2
The oil supplied to the valve 6 and the valve operating mechanism flows down through the oil return passage R1 provided in the cylinder head 26 and the cylinder 25, and communicates with the lower end of the oil return passage R1 from below the cylinder 25. The oil flows into the oil passage R2, is passed through an outlet 22E2 formed at the lower end of the passage R2, and is surrounded by a scattering prevention wall around a relief valve 32 provided in the left crankcase component member 23. It flows into the valve chamber S and flows down from here to the oil pan 21a located near the lower portion (see FIG. 3).

As described above, in this embodiment, even the oil that lubricates and cools the high parts such as the cylinder 25 and the cylinder head 26 flows down the oil passages R1 and R2, so that the crank wheel, the transmission gear, etc. Make sure that the lower oil pan 21a does not scatter into the internal mechanism.
Be led to. Therefore, the oil is not overheated in the process of returning to the oil pan 21a and the oil temperature does not rise, and the oil does not hit the rotating body such as the crank wheel to cause mechanical loss.

Further, when the oil pressure in the oil flow passage reaches a certain value or more, the oil is discharged from the relief valve 32 to reduce the oil pressure in the oil passage and keep the oil pressure constant. However, since the oil released at this time is also prevented from splashing to the surroundings by the splash prevention walls 22C and 23C, the oil temperature rises due to contact with the mechanism in the engine case 21, and mechanical loss occurs. Can be prevented. Therefore, in this embodiment, both the oil discharged from the relief valve 32 and the oil that has recirculated after the lubrication / cooling of the cylinders 25, 28 and the like are guided to the single relief valve chamber S. Since the relief valve chamber S is also used to prevent each oil from scattering, the structure of the crankcase 21 does not become particularly complicated.

In the above embodiment, the crankcase component 22 and the clutch cover 40, or
Although the concave groove is formed on each joint surface of the magnet cover 50, the concave groove is formed only on one of the joint surfaces of the crankcase constituent members 22 and 23 or the joint surface joined thereto. The oil passage may be formed, or the groove may be formed in both or one of the joint surfaces of both crankcase constituting members. Further, the oil passage formed on the joint surface can be formed not only as the oil return passage but also as the oil supply passage. Further, the relief valve chamber S includes a right side scattering prevention wall 22C projecting on the inner surface of the right crankcase constituting member 22 and a left scattering prevention wall 23C projecting on the inner surface of the left crankcase constituting member 23.
However, the relief valve chamber S has only a single shatterproof wall protruding from either of the crankcase constituent members 22 and 23.
It is also possible to form.

Further, in the above embodiment, the outlet 22E2 of the oil passage R2 is extended to the communicating position with the relief valve chamber S, but a connecting pipe is connected to the outlet of the oil passage. The oil may be guided to the internal space of the oil scattering prevention wall through this pipe. Further, the outlet 22E2 of the oil passage R2 does not necessarily need to be communicated with the relief valve chamber S as long as it is at a position facing and close to the oil pan 21a, and the present invention is particularly limited to the above embodiment. is not.

[0022]

As described above, according to the present invention, the oil supplied to the portion of the engine case that requires lubrication / cooling flows from the inlet formed in the groove to the inside of the groove and the outlet. Oil flows out and is stored in the oil pan, so oil does not scatter and hit the rotating body inside the engine case, and mechanical loss of the rotating body occurs and the oil temperature rises. Therefore, an appropriate oil feeding operation can be realized. Moreover, since the groove is formed on the joint surface of the engine case, the internal space of the engine case is not reduced or complicated, and the number of parts is not increased.

Further, the crankcase constituting the engine case is constructed by joining a pair of left and right crankcase constituting members, and one of the crankcase members has a relief valve and the other has an oil passage. Formed, the outlet of the oil passage is arranged in the vicinity of the relief valve, and the periphery of the outlet and the relief valve is
By covering with one of the crankcase constituent members with a curved anti-scattering wall, it is possible to prevent the oil discharged from the relief valve from scattering to the surroundings, and to prevent Since the scattering prevention wall can prevent the oil flowing out from the outlet from being scattered around, it is possible to more reliably prevent the oil temperature from rising and the mechanical loss from occurring. Further, since the shatterproof wall is a single piece, the crankcase constituent members do not become particularly complicated.

[Brief description of drawings]

FIG. 1 is a side view showing a motorcycle to which an embodiment of the present invention is applied.

FIG. 2 is a right side view showing the overall configuration of the engine case in FIG.

FIG. 3 is a sectional view taken along line AA of the one shown in FIG.

FIG. 4 is an outer side view of a right crankcase constituent member.

5 is an inner side view of what is shown in FIG. 4. FIG.

FIG. 6 shows the crankcase constituent members shown in FIG.
It is an arrow view seen from the direction.

7 is an arrow C showing the crankcase constituent member shown in FIG.
It is an arrow view seen from the direction.

FIG. 8 is an internal view of a left crankcase constituent member.

9 is a view of the left crankcase constituent member shown in FIG. 7 as viewed in the direction of arrow D. FIG.

10 is a view of the left crankcase constituent member shown in FIG. 8 as viewed in the direction of arrow E. FIG.

11 is an external view of the clutch cover shown in FIG.

FIG. 12 is an inner view of a clutch cover.

[Explanation of symbols]

20 engine 21 engine case 21a Oil pan 22,23 Crankcase components 22C Right side shatterproof wall 23C Left shatterproof wall 22D joint surface 22E groove 22E1 Inlet 22E2 outlet 40 Clutch cover (cover body) 50 Magnet cover (cover body) 32 relief valve R2 oil passage S relief valve chamber

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Claims (2)

(57) [Claims] 1. An oil passage structure for an engine, wherein cooling / lubricating oil supplied to a required place in an engine case forming an outer shell of the engine is made to flow down to an oil pan. A relief valve chamber for accommodating the relief valve is defined inside the engine case, and a discharge port for discharging oil toward an oil pan at the bottom of the engine case is formed below the partition wall of the relief valve chamber. An oil return passage is formed by forming a groove on at least one joint surface of the case and the cover body joined to the side end portion of the case, and openings are formed at both ends of the oil return passage. One of the parts is used as an inflow port for inflowing oil discharged from a required location in the engine case, while the other opening part is connected to the relief valve chamber as an outflow port. An oil passage structure for motorcycle engines, characterized in that 2. The engine case is provided with a crankcase formed by joining a pair of left and right crankcase constituent members, the concave groove is formed in one of the crankcase constituent members, and the left and right crankcase constituent members are formed. The oil passage structure for a motorcycle engine according to claim 1, wherein the anti-scattering walls are respectively formed on the inner surfaces, and the anti-scattering walls are joined to form the relief valve chamber.