JPH0523788Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a lubricating oil return device for a turbocharger in a lubrication system for an engine equipped with a turbocharger.

(Prior art) As a lubricating oil return device for a turbocharger, as in the conventional example shown in Japanese Utility Model Application Publication No. 53-163406, the lubricating oil coming out of the lubricating oil return port of the turbocharger is returned inside the oil pan mainly due to its own weight. There are some that are configured to be returned to .

(Problem that the invention aims to solve) In a slant engine that tilts with the exhaust side facing downward, the height difference (head) between the lubricating oil return port of the turbocharger and the lubricating oil level in the oil pan is small. (see FIGS. 1 and 2), and since the lubricating oil return pipe is bent in order to avoid interference with other parts, the return of lubricating oil is much worse than in the conventional example.

A concrete explanation of this is as follows. That is, the lubricating oil return pipe usually has a structure in which the lubricating oil return port is opened in the space above the oil surface of the oil pan, but if such a structure is applied to a slant engine, the above-mentioned height Since the difference is small, there are many horizontal parts in the lubricating oil return pipe, making it difficult for the lubricating oil to return. In addition,
In the engine layout where the difference in height is small as described above, the lubricating oil is The oil return port is not opened below the oil level. The reason for this is that when the vehicle turns, etc., the lubricating oil flows backward from the lubricating oil return port due to centrifugal force and tends to reach the bearing of the turbocharger, where there is a risk of oil leakage.

Furthermore, since the lubricating oil return pipe must be installed in a limited space in the engine room to avoid interference with other parts, the lubricating oil return pipe is bent so as to follow the engine body as much as possible. will be done. By the way, the lubricating oil after lubricating the turbocharger is already mixed with blow-by gas in the crankcase, or exhaust gas or supercharged air leaks from the seal part of the turbocharger part, but as mentioned above, If the lubricating oil return pipe is installed in a bent state, the blow-by gas, exhaust gas, and supercharging air (hereinafter collectively referred to as gas) may become clogged at the bent part of the lubricating oil return pipe. The upward force of the gas acts, making the return of lubricating oil even worse. As a result, the gas may obstruct the smooth flow of lubricating oil in the lubricating oil return pipe, or in severe cases, the lubricating oil return pipe may become gas-locked, causing a problem in which lubricating oil no longer flows toward the oil pan. . 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 problems such as generation of white smoke.

Therefore, in order to eliminate the above-mentioned problems, the applicant has
An application has been filed for utility model registration for the prior art shown in Figure 2 (Utility Model Application No. 59-21176, filed on February 15, 1988). In this prior art, a lubricating oil return pipe c that returns lubricating oil from a turbocharger a to an oil pan b using its own weight is arranged so as to have a bent part in a space below the turbocharger a and extending toward the slant engine side. The return port d of the lubricating oil return pipe c is opened below the lubricating oil level in the oil pan b, and the lubricating oil in the vicinity of at least one bend of the lubricating oil return pipe c and in the crankcase e is opened. This is characterized in that the space f above the oil level is connected to the space f by a bypass pipe g.

And according to this prior art, the lubricating oil return pipe c
By opening the return port d below the surface of the lubricating oil in the oil pan b, maximizing the height difference as much as possible, and increasing the return force due to its own weight as much as possible,
Reduces disadvantages in slant engines.
In order to avoid interference with other parts, the problem of backflow of lubricating oil that occurs when the vehicle turns, etc., which is newly caused by opening the return port d below the oil level, is solved by a bent part provided in the lubricating oil return pipe c to avoid interference with other parts. This is resolved by resistance and throttling action.

Further, the above-mentioned prior art allows the gas accumulated in the lubricating oil return pipe c to be discharged to the upper space f in the crankcase e through the bypass pipe g, and has the effect of smoothing the flow of lubricating oil. However, the pressure inside the crankcase e is atmospheric pressure or higher, and the gas inside the lubricating oil return pipe c is not actively sucked out, so there is a limit to the above effect.

In view of the above, the present invention aims to improve the prior art to enhance the gas discharge effect and to further smooth the flow of lubricating oil in the lubricating oil return pipe.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a lubricating oil return device for a turbocharger disposed on the exhaust side of a slant engine which is inclined with the exhaust side facing down. A lubricating oil return pipe that returns lubricating oil to the pan using its own weight is arranged with a bend in the space below the turbocharger and extending toward the slant engine, and the return port of this lubricating oil return pipe is A cam in an oil separator chamber or cylinder head cover for blow-by gas recirculation that opens below the oil level of the lubricating oil in the oil pan and is provided near at least one bent portion of the lubricating oil return pipe and inside the cylinder head cover. The oil separator chamber is connected to a portion near the communication portion of the cam chamber with a gas vent pipe, and the oil separator chamber and a portion of the intake passage downstream of the throttle valve are connected from the oil separator chamber to the throttle valve. It is characterized in that it is connected by a reflux pipe equipped with a check valve that allows flow only to areas downstream of the valve.

(Action) According to the present invention, the effect that the prior art has,
In other words, the return force due to the weight of the lubricating oil can be made as large as possible, which can reduce the disadvantages of slant engines, and the bending parts provide resistance to the backflow of lubricating oil when the vehicle turns, allowing the lubricating oil to flow to the bearing part of the turbocharger. This prevents backflow and prevents oil leaks from occurring.

Further, according to the present invention, the oil separator chamber for blow-by gas recirculation is connected to a portion of the intake passage downstream of the throttle valve by a recirculation pipe equipped with a check valve that allows flow only to a portion of the intake passage downstream of the throttle valve. As a result, the gas in the lubricating oil return pipe can be actively sucked and discharged through the gas vent pipe by utilizing the fact that the oil separator chamber becomes negative pressure. The flow of lubricating oil in the return pipe can be made much smoother.

Further, according to the present invention, since the recirculation pipe is equipped with the check valve as described above, the supercharged air when the throttle valve is fully opened is introduced into the lubricating oil return pipe through the oil separator chamber and, ultimately, the gas vent pipe. can be prevented.

(Embodiment) In the embodiment of the present invention shown in FIG. 1, the engine body 5 of the slant engine 8 is arranged inclined with the exhaust side facing downward, and the turbocharger 1 is arranged on the exhaust side. The lubricating oil in the oil pan 2 is sucked up by an oil pump 10 and sent under pressure to a bearing housing 12 of the turbocharger 1 via a turbocharger oil supply pipe 11. The lubricating oil flowing 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 into the lubricating oil return pipe 3. The lubricating oil then returns to the oil pan 2 through the return port 4 through the lubricating oil return pipe 3 mainly due to its own weight.

In order to avoid interference with other parts, the lubricating oil return pipe 3 is bent along the engine body 5 as much as possible, and as shown in FIG. It is placed in a space on the side.

A bent portion A of the lubricating oil return pipe 3 located above the oil level is connected by a gas vent pipe 7 to an oil separator chamber 20 in a cam chamber 19 formed inside the cylinder head cover. This gas vent pipe 7 is located at a position slightly removed from the oil separator chamber 20 and is connected to the cam chamber 1 in the cylinder head cover at a location where the negative pressure of the intake manifold 23 acts via the oil separator chamber 20.
It may be connected to 9. Specifically, the gas vent pipe 7 may be connected to the cam chamber 19 near the communication portion P between the oil separator chamber 20 and the cam chamber 19.

The connection point of the gas vent pipe 7 can be selected at a bent part in the lubricating oil return pipe 3 where the gas tends to accumulate; for example, as shown by the imaginary line in FIG. A gas vent pipe 7 can also be connected to the bent portion B.

The oil separator chamber 20 is equipped with a baffle plate 21 for separating lubricating oil from the blow-by gas, and is also connected to the intake manifold 2 via a return pipe 22.
It is connected to 3. A check valve 24 and a throttle 25 are disposed in the reflux pipe 22, and the check valve 24 is configured to allow flow only from the oil separator chamber 20 to a portion downstream of the throttle valve 26. The intake manifold 23 is located downstream of the throttle valve 26 of the carburetor and has negative pressure, so that negative pressure acts on the oil separator chamber 20.

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

(Effects of the invention) According to the invention, the return port of the lubricating oil return pipe can be used in the lubricating oil return device of a turbocharger in a slant engine, which tends to have insufficient head and insufficient oil return force due to its own weight. The simple structure of opening below the oil level and adding a gas vent pipe prevents gas lock and allows the lubricating oil to flow smoothly and return smoothly from the turbocharger to the oil pan.
The problem of lubricant backflow when the vehicle turns can be solved by the bent portion provided in the lubricant return pipe to avoid interference with other parts.

Furthermore, according to the present invention, the gas in the lubricating oil return pipe can be actively sucked and discharged by using the negative pressure in the oil separator chamber, and as a result, the gas discharge effect is significantly enhanced compared to the prior art. The flow of lubricating oil in the lubricating oil return pipe can be made even smoother. The check valve function prevents supercharged air from being introduced into the lubricating oil return pipe during supercharging operation.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, and FIG. 2 is a system diagram showing a prior art. 1...Turbo charger, 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...Return pipe, 24...Check Valve, 26... Throttle valve, A... Bent part.

Claims (1)

[Claims for Utility Model Registration] In a lubricating oil return device in a turbocharger disposed on the exhaust side of a slant engine tilted with the exhaust side facing downward, a lubricant that returns lubricating oil from the turbocharger to an oil pan using its own weight. An oil return pipe is arranged so as to have a bent part in the space below the turbocharger and extending to the slant engine side, and the return port of this lubricating oil return pipe is opened below the surface of the lubricating oil in the oil pan. , an oil separator chamber for blow-by gas recirculation provided near at least one bent portion of the lubricating oil return pipe and inside the cylinder head cover, or a cam chamber in the cylinder head cover, wherein the oil separator chamber and the cam chamber A gas vent pipe is used to connect the oil separator chamber and a portion of the intake passage downstream of the throttle valve, and a check is made to allow flow only from the oil separator chamber to the portion downstream of the throttle valve. A lubricating oil return device for a turbocharger, characterized in that it is connected by a return pipe equipped with a valve.