JPH0729227Y2 - Lubricating oil return device for turbocharger - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil returning device for a turbocharger in a lubricating system for an engine equipped with a turbocharger.

[0002]

2. Description of the Related Art As a lubricating oil return device for a turbocharger, as in the conventional example disclosed in Japanese Utility Model Publication No. Sho. Some are configured to be returned to.

[0003]

In a slant engine in which the exhaust side is inclined downward, the height difference (fall) between the lubricating oil return port of the turbocharger and the oil surface of the lubricating oil of the oil pan is small. (Refer to FIG. 1 and FIG. 2) Also, since the lubricating oil return pipe avoids interference with other parts and is bent and piped, the returning of the lubricating oil becomes extremely worse than in the above-mentioned conventional example.

This will be specifically described as follows. That is, the lubricating oil return pipe has a structure in which the lubricating oil return port is normally opened in the space above the oil surface of the oil pan. However, when such a structure is applied to a slant engine, Since the difference is small, there are many horizontal portions in the lubricating oil return pipe, and the lubricating oil returns poorly. In the engine layout in which the height difference is small as described above, except when the lubricating oil is forcibly returned by using the drain oil pump as disclosed in JP-A-58-135325. The lubricating oil return port is not opened below the oil level. The reason is that, when the vehicle is turning, the lubricating oil flows back from the lubricating oil return port due to centrifugal force and easily reaches the bearing portion of the turbocharger, which may cause oil leakage.

Further, since the lubricating oil return pipe must be arranged in a limited space in the engine room while avoiding interference with other parts, the lubricating oil return pipe is bent along the engine body as much as possible. It will be piped in the state. By the way, blow-by gas is already mixed in the lubricating oil after lubricating the turbocharger in the crankcase, or exhaust gas or supercharged air leaks from the seal part in the turbocharger part,
When the lubricating oil return pipe is bent as described above, the blow-by gas, exhaust gas, and supercharged air (hereinafter collectively referred to as gas) tend to be clogged at the bent portion of the lubricating oil return pipe. Then, the upward force of this gas acts and the return of the lubricating oil becomes worse. As a result, the gas impedes the smooth flow of the lubricating oil in the lubricating oil return pipe, and in the worst case, the lubricating oil return pipe is gas-locked, causing a problem that the lubricating oil does not flow toward the oil pan at all. As a result, the lubricating oil in the bearing housing of the turbocharger leaks to the exhaust turbine side or the supercharging blower side, causing a problem such as white smoke.

Therefore, in order to solve the above-mentioned problems, the present applicant has filed a utility model registration application for the prior art shown in FIG. 2 (Japanese Utility Model Application No. 59-21176, filed on February 15, 1984). In this prior art, the lubricating oil return pipe c for returning the lubricating oil from the turbocharger a to the oil pan b using its own weight is provided with a bent portion in the space below the turbocharger a on the slant engine side. The lubricating oil return pipe c is provided with a return port d opened below the oil surface of the lubricating oil of the oil pan b, and at least one bent portion of the lubricating oil return pipe c and the crankcase e are lubricated. The upper space f above the oil level of the oil is connected by a bypass pipe g.

According to this prior art, the return port d of the lubricating oil return pipe c is opened below the oil level of the lubricating oil in the oil pan b to maximize the height difference and maximize the returning force due to its own weight. This reduces the disadvantages of slant engines. Then, the problem of the lubricating oil backflow, which occurs newly when the vehicle is turning due to the opening of the return port d below the oil surface, is caused by the bent portion provided in the lubricating oil return pipe c in order to avoid interference with other parts. It is eliminated by the resistance / throttle action.

Further, the above-mentioned prior art has an effect that the gas accumulated in the lubricating oil return pipe c can be discharged to the upper space f in the crankcase e through the bypass pipe g, and the lubricating oil flow can be made smooth. However, since the pressure in the crankcase e is atmospheric pressure or higher and the gas in the lubricating oil return pipe c is not positively sucked and discharged, the above effect is limited.

In view of the above, it is an object of the present invention to improve the prior art by improving the gas discharge effect and further smooth the flow of lubricating oil in the lubricating oil return pipe.

[0010]

In order to achieve the above object, the present invention provides a lubricating oil returning device for a turbocharger disposed on the exhaust side of a slant engine which is inclined with the exhaust side facing down, from the turbocharger. A lubricating oil return pipe that returns the lubricating oil to the oil pan by using its own weight is arranged so that it has a bent portion in the space below the turbocharger and on the slant engine side. An oil separator chamber or a cylinder head for blow-by gas recirculation, which is provided in the vicinity of at least one bent portion of the lubricating oil return pipe and inside the cylinder head cover, with a mouth opened below the surface of the lubricating oil in the oil pan.
The cam chamber in the cover, which is the same as the oil separator chamber
Connect the area near the communication with the chamber with a gas vent pipe,
The oil separator chamber and the intake passage are connected by a return pipe.

[0011]

According to the present invention, the operation which the prior art has,
In other words, the return force due to the self-weight of the lubricating oil can be made as large as possible to reduce the disadvantages in the slant engine, and the resistance of the bent portion is given to the lubricating oil reverse flow at the time of vehicle turning etc. to give the lubricating oil to the bearing portion of the turbocharger. It is possible to prevent the oil from flowing back and prevent oil leakage from occurring.

Further, according to the present invention, since the oil separator chamber for the blow-by gas recirculation is connected to the intake passage by the recirculation pipe, the negative pressure in the oil separator chamber is utilized to utilize the negative pressure in the lubricating oil return pipe. Since the gas can be positively sucked and discharged through the degassing pipe, the flow of the lubricating oil in the lubricating oil return pipe can be remarkably smoothed as compared with the prior art.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention shown in FIG. 1, an engine body 5 of a slant engine 8 is disposed so as to be inclined with its exhaust side facing downward, and a turbocharger 1 is disposed on the exhaust side. Lubricating oil in the oil pan 2 is sucked up by an oil pump 10 and is pumped to a bearing housing 12 of the turbocharger 1 through a turbocharger oil supply pipe 11. The lubricating oil that has flowed into the bearing housing 12 from the oil supply port 13 of the turbocharger 1 lubricates the internal bearing portion and then flows out from the lubricating oil return port 9 to the lubricating oil return pipe 3. Next, the lubricating oil mainly returns to the oil pan 2 through its return port 4 through the lubricating oil return pipe 3 by its own weight.

In order to avoid interference with other parts, the lubricating oil return pipe 3 is arranged in a bent state along the engine body 5 as shown in FIG. 1, and in the space below the turbocharger 1. It is arranged in a space defined by the engine body 5 side.

A bent portion A located above the oil surface of the lubricating oil return pipe 3 and an oil separator chamber 20 in a cam chamber 19 formed inside the cylinder head cover are connected by a gas vent pipe 7. There is. This gas vent pipe 7 is a cam
The chamber 19, the oil separator chamber 20 and the cam chamber 1
You may connect to the location near the communicating part with 9 .

The connecting portion of the gas vent pipe 7 can be selected at a bent portion where the gas is likely to accumulate in the lubricating oil return pipe 3. For example, as shown by a phantom line in FIG. 1, in addition to the bent portion A, The gas vent pipe 7 can also be connected to the other bent portion B.

The oil separator chamber 20 is provided with a baffle plate 21 for separating lubricating oil from blow-by gas,
Further, it communicates with the intake manifold 23 via the return pipe 22. A check valve 24 and a throttle 25 are arranged in the return pipe 22, and the check valve 24 is configured to allow only the flow from the oil separator chamber 20 to the downstream portion of the throttle valve 26. Since the intake manifold 23 is located downstream of the throttle valve 26 of the carburetor and has a negative pressure, the negative pressure acts on the oil separator chamber 20.

In FIG. 1, 14 is a strainer, 15 is a supercharging blower of the turbocharger 1 arranged in the intake passage 16, and 17 is an exhaust turbine of the turbocharger 1 arranged in the exhaust passage 18.

[0019]

EFFECTS OF THE INVENTION According to the present invention, even in a lubricating oil returning device for a turbocharger in a slant engine in which the head cannot be sufficiently removed and the oil returning force due to its own weight tends to be insufficient, the returning port of the lubricating oil return pipe is With a simple structure that opens below the oil surface of and adds a gas vent pipe,
Preventing gas lock, smoothing the flow of lubricating oil and returning it smoothly from the turbocharger to the oil pan, and the bend in the lubricating oil return pipe to avoid interference with other parts It is possible to solve the problem of lubricating oil backflow during turning.

Further, according to the present invention, the gas in the lubricating oil return pipe can be positively sucked and discharged by utilizing the negative pressure of the oil separator chamber, resulting in a marked gas discharge effect as compared with the prior art. And the flow of the lubricating oil in the lubricating oil return pipe can be further smoothed.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a system diagram showing a prior art.

[Explanation of symbols]

 1 Turbocharger 2 Oil pan 3 Lubricating oil return pipe 4 Return port 7 Gas vent pipe 8 Slant engine 16 Intake passage 20 Oil separator chamber 22 Reflux pipe A Bent part

Claims (1)

[Scope of utility model registration request] 1. A lubricating oil returning device for a turbocharger arranged on the exhaust side of a slant engine that inclines with the exhaust side facing down, wherein the lubricating oil returns the lubricating oil from the turbocharger to an oil pan using its own weight. The return pipe is arranged so as to have a bent portion in the space below the turbocharger in the space on the slant engine side,
The return port of the lubricating oil return pipe is opened below the surface of the lubricating oil in the oil pan, and an oil separator for blow-by gas recirculation is provided near at least one bent portion of the lubricating oil return pipe and inside the cylinder head cover. Chamber or cylinder
A cam chamber in the head cover, the oil separator
A lubricating oil return device for a turbocharger, characterized in that a gas vent pipe is connected to a location near a communication portion between the chamber and the cam chamber, and the oil separator chamber and the intake passage are connected to each other via a reflux pipe.