JPS61182407A - Lubricator for 4-cycle engine - Google Patents

Abstract

PURPOSE:To prevent the exhaustion of oil and permit the certain lubrication by constituting an oil chamber from a transmission chamber arranged behind a crank chamber and preventing the stirring of oil and the imbalance of weight and feeding oil into each part of an engine by a pump. CONSTITUTION:When a piston 29 moves vertically with the start of an engine, the positive and negative pressure variation is repeated in a crank chamber 12. Then, a unidirectional valve 16 is opened and closed, and the oil in the crank chamber 12 is discharged into a transmission chamber 13 through a communication hole 15. Therefore, in the stationary state, the oil surface B in the transmission chamber 13 is set above the initial oil surface A. Therefore, oil exhaustion in a pump 20 is hardly generated. While, in the stationary state, the oil surface C in the crank chamber 12 is set lower than a crankshaft 32. Therefore, oil is not stirred by the crankshaft 32. The oil in the transmission chamber 13 is supplied into the crank chamber 12 and a cam chamber 22 through an oil passage 21 by the pump 20.

Description

[Detailed description of the invention] An industrial field of application The present invention relates to a lubrication device for a four-stroke engine.

'Conventional technology j In conventionally known four-stroke engines, in order to lubricate the valve train and cylinder sliding surfaces, the lower part of the crank chamber is made to protrude downward to form an oil surface, and oil is poured into the lower part of the crank chamber. The engine is equipped with an oil pump that supplies oil to the required locations within the engine. However, in an engine having such a structure, the engine body protrudes downward, making it difficult to make the engine compact, especially in the vertical direction.

Therefore, as an example of a 4-stroke engine that is designed to be more compact in the vertical direction, we will introduce an American [Dirt Bike Magazine, 11
In the September 1983 issue, there is a description of what is shown in Figure 1. This engine utilizes pressure fluctuations in the crank chamber 2 as the piston 1 moves up and down to drain oil in the crank chamber 2 to a cam chain chamber 3 installed adjacent to the side of the crank chamber.
The oil in the cam chain chamber 3 is scooped up by the cam chain 4 and moved to a predetermined location, thereby lubricating the valve train and cylinder sliding surfaces.

"Problems to be solved by the invention" However, in the four-stroke engine with the above configuration,
(a) Since the cam chain chamber 3 is used as an oil chamber, an oil agitation phenomenon occurs due to the cam chain 4, resulting in an increase in oil temperature and a decrease in engine output. (b) Also, the oil chamber is located on the side of the crank chamber (on the side with respect to the vehicle body), and when the engine is running, the weight balance is not favorable when the oil level height differs as shown in the figure. .

(C) The oil in the cam chain chamber 3 is supplied to each required part of the engine by the scraping of the chain 4.
When the vehicle body is tilted, the oil level may be below the cam chain 4. In that case, there is a problem that oil may run out and smooth lubrication may not be achieved.

The present invention has been made in view of the above circumstances, and it is possible to make the ennon more compact, prevent oil temperature rise and output decrease due to oil agitation, and maintain good weight balance even when the engine is running, and when the vehicle body is tilted. To provide a lubricating device for a four-stroke engine that can reliably supply oil to necessary parts of the engine even if there is a problem within the engine.

"Means for Solving Problems" In order to achieve the above object, the present invention provides a crank chamber which is defined in a sealed manner at the bottom of a cylinder and undergoes repeated positive and negative pressure fluctuations as the piston moves up and down; a transmission chamber defined at the rear of the crank chamber and communicating with the crank chamber through a communication hole; a one-way valve installed in the communication hole that allows oil to flow only from the crank chamber toward the transmission chamber; It is configured to include an oil pump that supplies oil from the transmission chamber to the cam chamber and crank chamber via a supply path.

"Embodiment" An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

FIG. 2 is a longitudinal sectional side view of an engine equipped with a lubricating device according to the present invention. In the figure, reference numeral 11 is a cylinder, and a crank chamber 12 is defined in the lower part of the cylinder 11 in a sealed state. Further, a mission chamber 13 is defined behind the crank chamber 12 (at the rear with respect to the vehicle body). The mission chamber 13 is connected to the crank chamber 1 by a partition wall 14.
2, and communicates with the crank chamber 12 via a communication hole 15 passing through the lower part of the bulkhead 14. A one-way valve 16 is provided in the communication hole 15 to allow oil to flow only from the crank chamber 12 to the transmission chamber 13.
is provided. The one-way valve 16 has a structure in which the upper end of a plate-shaped valve body is screwed from the mission chamber 13 side so as to close the communication hole 15, and functions as a one-way valve by the elastic action of the valve body itself. .

The transmission chamber 13 is provided with an oil pump 20 in addition to a main shaft 18 and a countershaft 19 that support gears for speed change. oil pump 2
The discharge port 0 is connected to the base end side of the oil supply passage 21, and the distal end side of the oil supply passage 21 extends to a required location within the crank chamber 12 and a required location within the cam chamber 22. Further, 23 is a clutch chamber (see FIG. 3), and this clutch chamber 23 is communicated with the cam chamber 22 via a cam chain chamber 24. The clutch chamber 23 is separated from the transmission chamber 13 by a partition wall 25, and a communication hole 27 is formed in the upper part of the partition wall 25 on the side facing the clutch 26.
(the fourth
(see figure).

On the other hand, 28 is a balance song hole for communicating the clutch chamber 12 with the transmission chamber 13, and this hole 28 is provided so as to pass through the side wall of the cylinder II and the partition wall 14, and is opened and closed by the vertical movement of the piston 29. be done. In addition, the balun long hole 28 is provided in an inclined state so that the mission chamber 13 side is downward in order to facilitate the flow of oil in the crank chamber 12 to the mission chamber 13 side. And crank chamber 12 and mission chamber 1
A balancing hole 14 is provided in the partition wall 14 that separates the
8 is provided with a temporary baffle 30 that extends to the center of the interior of the transmission chamber 13 to prevent oil in the transmission chamber 13 from flowing out to the crank chamber 12 through the balancing hole 28 even if the vehicle bounces. There is no such thing. 3 is a sole member disposed between the outer periphery of the end of the crankshaft 32 and the canon, and the generator chamber 33 provided on the side of the crank chamber 12 is connected to the crank chamber 12. 12 is in a sealed state. Note that 34 in FIG. 4 indicates an overflow communication hole provided in the partition wall 25.

Next, the operation of the lubricating device configured as described above will be explained.

The required type of oil is injected into the engine body in advance, and A in Fig. 2 represents the oil level when the engine is stopped. When the piston 29 moves up and down as the engine starts, the pressure inside the crank chamber I2 repeats positive and negative pressure fluctuations. Accordingly, the one-way valve 16 is opened and closed, and the crank chamber 12
The oil inside is discharged into the transmission chamber 13 through the communication hole 15 together with the breathing gas. As a result, the oil in the crank chamber 12 is gradually transferred to the transmission chamber 13 side, and in a steady state, the oil level in the mission chamber 13 becomes higher than the initial oil level A, as shown by B in FIG. Therefore, the oil pump 20 is less likely to run out of oil, and can reliably supply oil to the necessary internal parts of the engine.

On the other hand, in the above-mentioned steady state, the oil level in the crank chamber 12 is lower than that of the crankshaft 3, as shown by C in FIG.
It is located below the weight portion 32a of No. 2. Therefore, oil is not stirred by the crankshaft 32 inside the crank chamber 12, and oil is not stirred by a cam chain or the like outside the crank chamber 12 either. Therefore, it is possible to prevent inconveniences such as an increase in oil temperature and a decrease in engine output due to oil agitation as described in the conventional example. Note that rotating parts such as the transmission gear in the transmission chamber 13 can be placed above the oil level B as shown in FIG. It is possible to reduce oil temperature rise and output drop.

Furthermore, as mentioned above, when the engine is running, there is a level difference between the oil level in the crank chamber 12 and the oil level in the transmission chamber 13, which disrupts the heavy electrical balance between the two. 13 is placed after the rear of the vehicle with the vehicle body as a reference, so the imbalance in weight has almost no effect on the vehicle.

The oil accumulated in the mission chamber 13 is removed from the pop-up 2.
0 is supplied to required locations in the crank chamber 12 and the cam chamber 22 through the oil supply path 21 to lubricate the inner circumferential surface of the cylinder, the large and small ends of the connecting rod, the camshaft, etc. I do.

The oil after lubricating the required parts in the crank chamber 12 is
It flows down to the bottom of the crank chamber 12 as it is, and is returned into the mission chamber 13 via the communication hole 15 by the pumping action of the crank chamber I2 mentioned above.

On the other hand, the oil after lubricating the required parts in the cam chamber 22 travels along the wall surface of the cam chain chamber 24 and reaches the clutch chamber 23.
The oil that has reached the clutch chamber 23 is scraped up by the clutch constituent members and returned directly to the transmission chamber 13. In this way, all of the lubricated oil is not returned to the clutch chamber 12, but a portion of it is directly returned to the transmission chamber I3, so that it is possible to suppress the oil level in the clutch chamber 12 from rising, and the crankshaft 32 It is possible to more reliably prevent oil agitation from occurring.

Furthermore, in the above-described operation, if the volume of the crank chamber 12 is small, the negative pressure in the crank chamber 12 becomes too high;
Is there a risk of a decrease in output or loss of sealing performance?In the engine with configuration L, a balancing hole 28 is provided that opens and closes according to the vertical movement of the piston 29, so the pumping action of the crank chamber I2 is ensured. At the same time, it is possible to prevent the crank chamber 12 from becoming more negative pressure than necessary. Therefore, even if the volume of the crank chamber 12 is small, the output does not decrease and the normality is not impaired.

In the above embodiment, the piston 29 is used to open and close the balancing hole 28, or a rotary valve that operates in synchronization with the movement of the piston 29 is provided.
It may be configured to open and close in this way.

"Effects of the Invention" As explained above, according to the first invention of the present application, (a) the oil in the crank chamber is discharged into the transmission chamber, so the oil level in the crank chamber can be kept low, and the crank By preventing the oil from being agitated by the shaft, it is possible to prevent an increase in oil temperature and a decrease in output. (b
) The oil chamber is made up of the transmission chamber located behind the crank chamber, so even if the oil level differs between the oil chamber and the crank chamber when the engine is running, this will not affect the vehicle balance. It has little impact,
Maintains good weight balance. Further, there is no need to provide a special oil chamber, and cost reduction and compactness can be achieved. (C) Since oil is supplied to the required parts of the engine by a pump, oil may run out even when the vehicle is tilted.t)SohMh/In*rr side BM hill;
'fE/7'lStmL'IA.

Further, according to the second invention of the present application, in addition to the effects of the first invention,
The clutch chamber communicates with the cam chamber and transmission chamber and is used as an oil return passage, so the clutch can be lubricated and the oil after cam chamber lubrication can be returned directly to the transmission chamber, allowing the oil in the crank chamber to be returned directly to the transmission chamber. This has the effect that it is possible to more reliably prevent oil agitation caused by the crankshaft by lowering the engine speed.

Further, according to the third invention of the present application, in addition to the effects of the first invention,
Since the generator chamber is kept sealed from the crank chamber by the sealing member, lubricating oil does not reach the generator chamber, preventing oil agitation by the generator rotor. Since there is no heat conduction from the oil to the oil, it has the effect of suppressing the temperature rise of the oil.

Moreover, according to the fourth invention of the present application, in addition to the effects of the first invention,
Because it has a balancing hole that opens and closes with the vertical movement of the piston, it is possible to ensure the pumping of the crank chamber and prevent the negative pressure in the crank chamber from becoming too high, reducing output loss and sealing performance. The effects of this can be prevented from being damaged.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a partially cutaway side view showing a conventional example of a lubrication system for a four-stroke engine, FIGS. 2 to 4 show an embodiment of the present invention, and FIG. Figure 3 is a vertical side view of the engine, Figure 1 is a vertical front view of the engine, and Figure 1 is a vertical side view of the engine. -F is a view of the second side wall viewed from the side of the Minyong chamber. 11...Cylinder, 12...Crank chamber, 1
3 miso noyo 7th room, I4.25'... septum, 15.2
7 Communication hole, I6... One-way valve, 20...
...Oil pump, 21...Oil supply path, 22...
...Cam chamber, 23--Clutch chamber, 24--Cam chain chamber, 26-Clutch, 28--Balancing hole, 29--Piston, 31--
Seal member, 32... Crank no Yaft, 33
... Generator room. Figure 1 Figure 2

Claims (4)

[Claims] (1) A crank chamber which is defined in a sealed manner at the bottom of the cylinder and undergoes repeated positive and negative pressure fluctuations as the piston moves up and down;
A transmission chamber defined at the rear of the crank chamber and communicating with the crank chamber through a communication hole, and a one-way valve interposed in the communication hole that allows oil to flow only from the crank chamber toward the transmission chamber. A lubrication device for a four-stroke engine, comprising: a. (2) a crank chamber which is defined in a sealed manner at the bottom of the cylinder and undergoes repeated positive and negative pressure fluctuations as the piston moves up and down;
A transmission chamber defined at the rear of the crank chamber and communicating with the crank chamber through a communication hole, and a one-way valve interposed in the communication hole that allows oil to flow only from the crank chamber toward the transmission chamber. an oil pump that supplies oil in the transmission chamber to the cam chamber and crank chamber via a supply path; and a communication valve that is provided at the bottom of the cam chamber in communication with the cam chamber and that opens at the side of the clutch. and a clutch chamber communicating with the mission chamber via a passage.
Cycle engine lubrication system. (3) a crank chamber which is defined in a sealed manner at the bottom of the cylinder and undergoes repeated positive and negative pressure fluctuations as the piston moves up and down;
a transmission chamber defined at the rear of the crank chamber and communicating with the crank chamber through a communication hole; and a one-way valve interposed in the communication hole that allows oil to flow only from the crank chamber to the transmission chamber. , an oil pump that supplies oil in the transmission chamber to the cam chamber and the crank chamber via a supply path, and a generator chamber that is attached to the outer periphery of the end of the crankshaft and provided on the side of the crank chamber, to the crank chamber. A lubrication device for a four-cycle engine, comprising a seal member for maintaining a sealed state. (4) a crank chamber which is defined in a sealed manner at the bottom of the cylinder and repeats positive and negative pressure fluctuations as the piston moves up and down;
A transmission chamber defined at the rear of the crank chamber and communicating with the crank chamber through a communication hole, and a one-way valve interposed in the communication hole that allows oil to flow only from the crank chamber toward the transmission chamber. an oil pump that supplies oil in the transmission chamber to the cam chamber and crank chamber via a supply path; and an oil pump that is bored in the lower part of the cylinder and is opened and closed as the piston moves up and down, and when opened, supplies the crank chamber to the transmission. A lubrication device for a four-stroke engine, comprising a balancing hole communicating with a chamber.