JP2629937B2 - Motorcycle engine lubrication system - Google Patents

Abstract

PURPOSE:To directly supply oil at a lower part of a piston to improve cooling efficiency by providing an oil passage tube controlled in a specific posture from a joint face of a crank case and a side cover across a cam chain chamber to a lower part of the piston. CONSTITUTION:A crank shaft 5b is provided with a cam drive sprocket gear 21 as well as a cam chain chamber 23 above the gear 21. In the mentioned constitution, on a joint surface 31 on the side of a crank case 6, an oil passage tube 35 is inserted through a passage hole 34 drilled in parallel with the crank shaft 5b above the mentioned gear 21. The oil passage tube 35, after being passed through a cam chain 22 and a crank case side wall 7b, has its tip come to a lower part of a piston 2 located at a bottom dead center, that is, a slit 37 of a cylinder 1 to a crank web. Posture of the oil passage tube 35 is controlled by having its engaging valve 39 engaged with an engaging groove on a joint surface 33.

Description

Description: Object of the Invention (Industrial application field) The present invention relates to a motorcycle engine lubrication device for cooling a piston.

(Prior art) An engine mounted on a motorcycle uses an oil pump pumped from an oil pan at a lower bottom of a crankcase to lubricate a large end of a connecting rod, a crankshaft bearing, and a valve operating cam mechanism. Is formed on an oil passage penetrating through the thick part of the case or a mating surface with a side cover to be attached, and is supplied through an oil passage formed by a groove.

In order to cool the piston, including lubrication between the cylinder and the piston, and between the small end of the connecting rod and the piston pin, some oil is supplied to the lower surface of the piston by an oil jet.

As shown in FIG. 9, this oil jet device aims at the inner surface of the piston b just below the lower end edge of the piston b at the bottom dead center position and through the gap between the outer peripheral surface of the crank web c at the lower end opening of the cylinder a. And the crankcase d
An oil jet f is buried in the upper limit of the side wall e. The oil jet f is supplied with oil from an oil passage g guided through the thick portion of the crankcase side wall e.

In FIG. 10, an oil jet h is buried at a similar position to supply oil through an oil passage j provided on the outer periphery of a crankshaft bearing i.

However, the fitting holes k and l for burying the oil jets f and h in this way are different from other processing because the processing directions of the drills m and n are oblique, so that the jig cost and equipment cost are increased. Costs and man-hours increase, resulting in higher costs. Further, since many parts are arranged on the crankcase side wall e, it may be difficult to guide the oil passage from the lower part of the case while avoiding interference with these parts.

In addition, when replacing or cleaning the oil jet,
It is necessary to disassemble the cylinder part from the crankcase, and there is a problem that maintenance is not good.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned problems, and does not use a complicated oil passage, has good workability, and has an oil placed under a piston at a bottom dead center position. An object of the present invention is to provide a motorcycle engine lubricating device capable of supplying oil to a jet.

[Configuration of the invention]

(Means for Solving the Problems) To achieve the above object, a motorcycle engine lubricating apparatus according to the present invention provides a motorcycle in which a side cover covers a crankshaft protruding outward from a side wall of a crankcase. In the car engine, a through-hole is formed from the mating surface of the crankcase to which the side cover is attached, and penetrates the crank side wall perpendicular to the mating surface and directly below the piston at the bottom dead center position, and the oil is formed in the through-hole. The oil passage pipe is fitted with an oil jet at its closed end, and has a locking piece partially bent at a right angle at its open tail end. When inserted into the hole, the engaging piece is engaged with the engaging groove formed on the mating surface to control the posture so that the oil jet at the tip is directed to the inner surface of the piston. Oil is introduced from the oil passage to the tail end of the oil passage tube, and is injected to the lower surface of the piston via an oil jet at the tip.

(Operation) With such a configuration, the oil passage formed in the mating surface of the crankcase and the side cover is directly connected to the lower surface of the piston through the oil passage pipe inserted through the side wall of the crankcase. Oil can be injected.

Therefore, there is no need to drill an oil passage in the lower part of the crankcase or in the thickness of the side wall, and the through hole into which the oil passage pipe is inserted is orthogonal to the mating surface, and should be machined simultaneously with the screw hole for attaching the side cover. And high productivity. Further, the oil passage pipe can be extracted simply by removing the side cover, so that the maintenance property of the oil jet is good.

(Embodiment) Hereinafter, a drawing which is an embodiment of the invention will be described in detail.

FIG. 1 is a longitudinal sectional front view of a single-cylinder four-cycle engine provided with a lubricating device according to the present invention, and FIG. 2 is a longitudinal sectional side view taken along the line AA of FIG.

A piston 2 housed in a cylinder 1 is connected to a crank 4 via a connecting rod 3 and slides up and down with rotation of the crank 4. The crank 4 is supported by the side walls 7a and 7b of the crankcase 6 by the crankshafts 5a and 5b at both ends, and the crankshafts 5a and 5b are provided to protrude outside the side walls 7a and 7b.

A cylinder head 9 is superimposed on a cylinder block 8 forming the cylinder 1, and an intake passage 11 and an exhaust passage 12 are introduced into a combustion chamber 10 on a lower surface of the cylinder head 9, and are opened and closed by an intake valve 13 and an exhaust valve 14. Both valves 13 and 14 are opened and closed via rocker arms 18 and 19 by rotation of an intake cam 16 and an exhaust cam 17 on a camshaft 15 pivotally supported on the upper surface of the cylinder head 9.

The camshaft 15 has a cam-driven sprocket gear 20 pivotally supported at one end, and is driven via a cam chain 22 suspended between the camshaft 15 and a cam drive sprocket gear 21 on the crankshaft 5b. The cam chain 22 runs in a cam chain chamber 23 formed in the cylinder block 8 and the cylinder head 9.

A primary drive gear 24 is further fixed to the crankshaft 5b, and meshes with a primary driven gear 26 on the counter shaft 25. The rotation of the counter shaft 25 is transmitted through an opening / closing clutch 27, and the rotation of the counter shaft 25 is transmitted to a drive shaft 28 via a transmission gear mechanism (not shown). 29 is a drive sprocket gear for output.

A part of the crankshaft 5b, the cam drive sprocket gear 21, the primary drive gear 24, the primary driven gear 26, the opening / closing clutch 27, and a part of the counter shaft 25 are provided on one side of the crankcase 6 as a clutch cover.
Coated with 30.

Next, as shown in FIGS. 3 and 4, a concave groove 32 is formed in a mating surface 31 between the clutch cover 30 and the crankcase 6, and the gallery is formed by joining the crankcase 6, The oil delivered from the oil pump at the bottom of the crankcase by the oil pump is
The inside is guided as a part of an oil passage.

On the other hand, an oil passage pipe 35 is inserted into the mating surface 33 of the crankcase 6 at a position above the cam drive sprocket gear 21 and in a through hole 34 formed in parallel with the crankshaft 5b.

The oil passage pipe 35 passes through the inside of the annular shape of the cam chain 22 suspended upward from the cam drive sprocket gear 21 and further penetrates the crankcase side wall 7b, and its tip
35a is inserted just below the lower end edge of the piston 2 at the bottom dead center position and reaches a position facing the gap 37 between the outer peripheral side surface of the crank web 36 and the lower end opening of the cylinder 1.

As shown in FIGS. 5, 6, 7, and 8, the oil passage pipe 35 is provided with an oil jet 38 at a tip 35a, an open tail end 35b, and a part thereof. A locking piece 39 is formed by being bent outward at a right angle.
When inserted into the crankcase 6 as described above, the locking pieces 39 are fitted in the locking grooves 40 recessed in the mating surface 33 and positioned in the rotation direction, and the oil jet 38 at the tip is The attitude is controlled and fixed so as to aim at the lower surface of the piston 2 from the gap 37. The end face of the tail end 35b coincides with the mating surface 33 and communicates with the groove 32.

Thus, even if the cam chain chamber 23 exists between the clutch cover 30 and the crankcase 6, the oil passage pipe 35 is guided from the clutch cover 30 directly below the piston at the bottom dead center position beyond the cam chain chamber 23, and Cooling oil can be supplied to the lower surface of the piston 2 by the oil jet 38 provided at the tip.

Accordingly, it is not necessary to provide an oil passage within the thickness of the crankcase side wall 7b, and oil can be carried to the upper end of the side wall 7 using the oil passage formed on the mating surface of the crankcase 6 and the clutch cover 30. The performance is greatly improved, the cost is reduced, and if the clutch cover is removed, the oil passage pipe can be pulled out and the maintenance of the oil jet is easy.

Note that the same configuration can be applied to a side cover other than the clutch cover 30, for example, a magnet cover.

〔The invention's effect〕

As described above, the lubricating device for a motorcycle engine according to the present invention is configured such that the oil passing through the oil passage pipe from the mating surface with the side cover of the crankcase to below the piston at the bottom dead center position and provided on the mating surface The oil introduced from the passage is supplied to the lower surface of the piston via the oil jet at the tip of the oil passage.The piston can be cooled with a simple structure, the workability is good, the assembly is easy, and the cost is reduced. In addition, there is an effect that it is possible to achieve excellent maintainability.

[Brief description of the drawings]

1 is a vertical sectional front view of a single-cylinder four-stroke engine provided with a lubricating device according to an embodiment of the present invention, FIG. 2 is a vertical side view taken along the line AA of FIG. 1, and FIG. FIG. 4 is a longitudinal sectional side view in which the main part of FIG. 2 is enlarged, FIG. 5 is an enlarged front view of the oil passage pipe used in FIG. 1, and FIG. FIG. 5 is a sectional view taken along the line BB in FIG.
FIG. 7 is a sectional view taken along the line CC in FIG. 5, and FIG.
9 and 10 are longitudinal sectional front views showing a conventional piston cooling device. 21: cam drive sprocket gear, 22: cam chain, 23: cam chain chamber, 30: clutch cover (side cover), 31, 33: mating surface, 32: concave groove, 3
5 ... oil passage tube, 38 ... oil jet, 39 ... locking piece, 40 ... locking groove.

Claims (1)

(57) [Claims] In a motorcycle engine in which a side cover covers a crankshaft protruding outward from a side wall of a crankcase, a surface of the crankcase to which the side cover is attached is perpendicular to the mating surface of the crankcase. A through-hole is formed through the crankcase side wall immediately below the piston at the bottom dead center position, and an oil passage tube is inserted into the through-hole. The oil passage tube is provided with an oil jet at a closed end. A locking piece that is partially bent at a right angle is formed at the opened tail end, and the locking groove formed on the mating surface with the locking piece when the fitting piece is inserted into the through hole. The attitude is controlled so that the oil jet at the tip is directed toward the inner surface of the piston by engagement, and oil is introduced into the tail end of the oil passage pipe from the oil passage formed at the mating surface, and the oil jet at the tip is Lubrication system for a motorcycle engine, characterized in that it is to be injected into the piston underside through the door.