JPH0437243B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an engine oil recovery device that reliably recovers oil that lubricates various parts of the engine into an oil pan, and also makes it possible to sufficiently discharge blow-by gas from the oil pan.

[Conventional technology]

In an engine equipped with a wet sump type lubrication system, an oil pan with an open upper surface is attached to the bottom of the crankcase, and a large amount of oil necessary for lubrication is stored in the oil pan. The oil in the oil pan is then supplied to each part of the engine by an oil pump for lubrication, and the oil after lubrication is allowed to fall naturally and returned to the oil pan. By the way, in this wet sump method,
Since the blow-by gas leaking into the crank chamber comes into direct contact with the oil in the oil pan, the oil tends to deteriorate. In addition, since the oil in the oil pan can flow freely without any restrictions, the oil surface can become significantly tilted or wavy depending on the vehicle's driving conditions, such as turning or climbing up and down hills, or the back pressure of the piston. Due to such fluctuations in the oil level,
There was a problem in that the oil agitation resistance due to the crank web increased, deteriorating engine output and fuel efficiency. Furthermore, large fluctuations in the oil level can cause oil to block the oil return passage or enter the blow-by gas recirculation passage, resulting in oil blow-out. Another problem was that the oil strainer was exposed due to fluctuations in the oil level and sucked in air, reducing the oil pump's discharge pressure and causing a lack of oil supply. Therefore, it has been proposed to install a double plate having an oil recovery port with a check valve between the crankcase and the oil pan to partition the crank chamber and the inside of the oil pan. (see publication). According to this prior art, fluctuations in the oil level due to vehicle driving conditions such as turning and climbing hills are regulated by the bumpy plate, so oil agitation resistance does not increase and deterioration of engine output and fuel efficiency is prevented. It is possible.

[Problem to be solved by the invention]

By the way, in the prior art described in the above-mentioned publication, the check valve is a normally open type that closes the oil recovery port of the buttful plate in accordance with the rise of the oil level in the oil pan, and therefore It is normally in communication with the inside of the oil pan via an oil recovery port. Therefore, the blow-by gas in the crank chamber freely enters the oil pan and deteriorates the oil in the oil pan, and once the blow-by gas enters the oil pan, it tends to stay and is not easy to discharge. Furthermore, since the piston back pressure is applied to the inside of the oil pan via the oil recovery port, there is a possibility that the oil surface may become wavy. SUMMARY OF THE INVENTION An object of the present invention is to provide an engine oil recovery device that can effectively reduce deterioration of oil in an oil pan and easily discharge blow-by gas from the oil pan.

[Means to solve the problem]

For this purpose, in the engine oil recovery device according to the present invention, an oil pan is connected to the lower part of the crankcase via a baffle plate, and the crank chamber above the buffle plate and the rocker chamber in the rocker cover are connected to the first rocker chamber. In an engine that is communicated via a blow-by gas recirculation passage, the above-mentioned buttful plate is installed at an angle so as to form a space above the oil surface in the oil pan higher on one side, and the above-mentioned buttful plate is installed at an angle below the inclination direction of the above-mentioned buttful plate. The side part is provided with an oil recovery hole equipped with a normally closed one-way valve that opens when the pressure in the crank chamber increases due to piston back pressure. This means that a second blow-by gas reflux passage is provided which communicates with the blow-by gas. In addition, an oil recovery hole that is always open is provided in the lower part of the buttful plate in the direction of inclination, and an oil recovery hole is provided in the upper part of the part in the direction of inclination of the buttful plate to prevent pressure between the crank chamber and the upper space in the oil pan. The means is that a small hole for pressure balance is provided to adjust the balance.

[Effect]

According to an engine oil recovery device that employs such a method, fluctuations in the oil level in the oil pan due to driving conditions such as turning the vehicle or going up and down hills are regulated by the buttful plate and do not affect the crank chamber side. Therefore, oil agitation resistance does not increase, and deterioration of engine output and fuel efficiency is prevented. During operation of the engine, lubricated oil that naturally falls onto the buff-full plate accumulates along the inclination of the buff-full plate at a lower portion in the direction of the inclination. When the pressure inside the crank chamber increases due to the back pressure of the piston and the one-way valve opens, the oil is forcibly collected into the oil pan through the oil recovery port by the pressure inside the crank chamber. Here, the blowby gas that leaked into the crank chamber is discharged to the rocker chamber through the first blowby gas recirculation passage, and the blowby gas that entered the oil pan through the oil recovery port when the one-way valve was opened is The blow-by gas is discharged from the upper part of the space above the surface into the rocker chamber through the second blow-by gas recirculation passage. Therefore, blow-by gas can be easily discharged. In addition, the one-way valve is configured to open only when the pressure in the crank chamber increases due to the back pressure of the piston, and is not always open, so the amount of blow-by gas that enters the oil pan from the crank chamber is reduced. . Therefore, deterioration of the oil in the oil pan is reduced. Furthermore, the second blow-by gas recirculation passage communicates with the upper part of the space above the oil surface that is formed high on one side of the oil pan by the tilted buttful plate, so oil flows in due to fluctuations in the oil surface. There is little risk of oil blowing.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In the attached drawing showing a cross section of an engine equipped with a wet sump type lubrication system, reference numeral 1 is a crankcase, 2 is a cylinder, and a crankshaft 3 in the crankcase 1 is connected to a piston 5 in the cylinder 2 via a connecting rod 4. It is connected. Also,
An oil pan 6 is attached to the bottom of the crankcase 1, and lubricating oil is stored there. The cylinder head 7 at the top of the cylinder 2 is covered with a rocker cover 8 that covers the valve mechanism, and the space between the rocker chamber 9 in the rocker cover 8 and the crank chamber 10 in the crankcase 1 is a first blow-by gas. They are communicated via a reflux passage 11 and an oil return passage 12, respectively. In addition, piston 5
Since the cylinder 2 is slightly inclined from the vertical direction along with the sliding direction of the cylinder 2, the first blow-by gas recirculation passage 11 is arranged on the upper side of the slope of the cylinder 2, and the oil return passage 12 is arranged on the lower side of the slope. ing. Further, an oil separator 13 is installed in the upper part of the rocker chamber 9 to separate the blow-by gas from the oil contained therein.
Only the blow-by gas from the air cleaner 3 is sucked into the air cleaner 15 side through the passage 14 and refluxed. Here, a bump-full plate 16 is provided in an inclined manner between the bottom of the crankcase 1 and the oil pan 6, and the bump-full plate 16 connects the crank chamber 10 and the space 17 above the oil surface in the oil pan 6. are separated. A hole 2 opens in the lower part of the buff full plate 16 in the inclined direction.
6, strainer 1 placed on the oil pan 6 side
8 and an oil pump 19 arranged in the crank chamber 10, a suction pipe 20, an oil level gauge, etc. are inserted therethrough. In addition, in the buffer plate 16, an oil recovery port 21 is opened at the lower part in the direction of inclination where naturally falling oil after lubrication tends to accumulate, and a small oil recovery port 21 is opened in the upper part in the direction of inclination. Hole 2
3 is drilled. And the above oil recovery port 2
1 is attached with a one-way valve 22 that opens only with positive piston back pressure within the crank chamber 10. Here, when the one-way valve 22 is opened by positive piston back pressure and oil is recovered into the oil pan 6, blow-by gas also enters the oil pan 6 and accumulates in the space 17 above the oil surface.
Therefore, an air vent hole 24 for discharging this blow-by gas is bored in the oil pan 6 so as to communicate with the upper part of the space 17 above the oil surface, and this air vent hole 24 is connected to the second blow-by gas recirculation passage. Similarly to the first blow-by gas recirculation passage 11, it communicates with the rocker chamber 9 via the blow-by gas recirculation passage 11. In an embodiment configured in this manner, when the engine is stopped, lubricating oil is stored in the oil pan 6 as before, so the oil level can be checked easily as before. Next, when the engine is in operation, oil in the oil pan 6 is pumped up from the strainer 18 through the suction pipe 20 by the operation of the oil pump 19, and is pumped to various parts of the engine for lubrication. After lubrication, the oil falls directly onto the inclined buff-full plate 16 by itself, or falls from the rocker chamber 9 by its own weight through the oil return passage 12, and flows along the slope of the buff-full plate 16 to its lower part. Accumulate. Here, a relatively large pulsating pressure is always generated in the crank chamber 10 due to the back pressure of the piston 5, and the one-way valve 22 is intermittently opened by the positive pressure of this pulsating pressure. Therefore, the oil accumulated in the lower part of the vertical plate 16 is removed from the crank chamber 1.
Due to the pressure within 0, the oil is forcibly dropped into the oil pan 6 through the oil recovery port 21 and collected. In this way, even if the oil after lubrication may temporarily accumulate on the buff-full plate 16, it is quickly collected in the oil pan 6, and as a result, only a small amount of oil remains on the buff-full plate 16. This is a large amount of oil, and the inside of the crank chamber 10 is in a state similar to that of a dry sump system where there is almost no oil. Even if the oil level in the oil pan fluctuates when the vehicle turns or climbs or descends a slope, the fluctuation is regulated by the bumpy plate 16 and the crank chamber 10
Since it does not affect the side, oil agitation resistance does not increase, and deterioration of engine output and fuel efficiency is prevented. On the other hand, most of the blowby gas leaking into the crank chamber 10 flows through the first blowby gas recirculation passage 11.
It is discharged to the rocker chamber 9 side through. When the one-way valve 22 opens, the blow-by gas in the crank chamber 10 enters the oil pan 6 together with the lubricated oil, but the one-way valve 22 causes the pressure in the crank chamber 10 to increase due to the back pressure of the piston 5. Since it is configured to open only when the engine is in use and is not open all the time, the amount of blow-by gas that enters the oil pan 6 is reduced compared to before, and as a result, the deterioration of the oil in the oil pan 6 is also reduced compared to before. do. Then, due to the back pressure of the piston 5, the crank chamber 1
When the pressure inside 0 rises and the one-way valve 22 opens, the blow-by gas accumulated in the space 17 above the oil surface of the oil pan 6 flows from the air vent hole 24 to the second blow-by gas recirculation passage 25 to the rocker chamber. 9 side, where it is separated into gas and liquid by the oil separator 13, and then transferred to the air cleaner 1
5 and then refluxed. Here, since the air vent hole 24 opens at the upper position of the space 17 above the oil surface, there is little risk of oil flowing in due to fluctuations in the oil surface and causing oil blowout.

【Effect of the invention】

As explained above, according to the present invention, fluctuations in the oil level in the oil pan due to driving conditions such as turning the vehicle and climbing up and down slopes are regulated by the bumpy plate and do not affect the crank chamber side, so oil agitation resistance does not increase, and deterioration of engine output and fuel efficiency is prevented. During operation of the engine, lubricated oil that naturally falls onto the buff-full plate accumulates along the inclination of the buff-full plate at a lower portion in the direction of the inclination. When the pressure inside the crank chamber increases due to the back pressure of the piston and the one-way valve opens, the oil is forcibly collected into the oil pan through the oil recovery port by the pressure inside the crank chamber. Here, the blowby gas that leaked into the crank chamber is discharged to the rocker chamber through the first blowby gas recirculation passage, and the blowby gas that entered the oil pan through the oil recovery port when the one-way valve was opened is The blow-by gas is discharged from the upper part of the space above the surface into the rocker chamber through the second blow-by gas recirculation passage. Therefore, blow-by gas can be easily discharged. In addition, the one-way valve is configured to open only when the pressure in the crank chamber increases due to the back pressure of the piston, and is not always open, so the amount of blow-by gas that enters the oil pan from the crank chamber is reduced. . Therefore, deterioration of the oil in the oil pan can be effectively reduced. Furthermore, the second blow-by gas recirculation passage communicates with the upper part of the space above the oil surface that is formed high on one side of the oil pan by the tilted buttful plate, so oil flows in due to fluctuations in the oil surface. There is little risk of oil blowing.

[Brief explanation of drawings]

The drawing is a sectional view schematically showing an embodiment of the oil pan structure of the present invention. 1...Crankcase, 2...Cylinder, 3...
...Crankshaft, 4...Conrod, 5...Piston, 6...Oil pan, 7...Cylinder head,
8...Rotsuka cover, 9...Rotska room, 10...
... Crank chamber, 11 ... First blow-by gas recirculation passage, 12 ... Oil return passage, 13 ... Oil separator, 14 ... Passage, 15 ... Air cleaner, 16 ... Bumpy plate, 17 ... Oil surface Upper space, 18... Strainer, 19... Oil pump, 20... Suction pipe, 21... Oil recovery port, 22... One-way valve, 23... Small hole for pressure balance, 24... Air vent hole, 25
...Second blow-by gas recirculation passage, 26...
Hole.

Claims (1)

[Claims] 1. An oil pan is connected to the lower part of the crankcase via a baffle plate, and a crank chamber above the buffle plate and a rocker chamber in a rocker cover are connected to each other via a first blow-by gas recirculation passage. In the engine to be communicated with, the above-mentioned buttful plate is installed at an inclination so as to form a space above the oil surface in the oil pan higher on one side, and the lower part of the above-mentioned buttful plate in the inclination direction is provided with a piston back. A second blow-by is provided with an oil recovery hole equipped with a normally closed one-way valve that opens when the pressure in the crank chamber increases due to pressure, and communicates the upper position of the space above the oil surface in the oil pan with the rocker chamber in the rocker cover. An engine oil recovery device characterized by having a gas recirculation passage. 2. An oil recovery hole that is always open is provided in the lower part of the buttful plate in the direction of inclination, and a pressure balance between the crank chamber and the upper space in the oil pan is provided in the upper part of the part of the buttful plate in the direction of inclination. 2. The engine oil recovery device according to claim 1, further comprising a pressure balance small hole for adjusting the pressure balance.