JPH03156126A - Lubrication device of engine with exhaust turbo type supercharger - Google Patents

Abstract

PURPOSE:To ensure lubricating a supercharger when an engine starts, by making an oil supply passage in non-connecting state with an oil return side, which passage communicates with an oil passage for an exhaust turbo type supercharger when the key switch of the engine is operated to ON condition. CONSTITUTION:A turbine shaft 17a is lubricated by supplying a exhaust turbo type supercharger 10 with part of oil for a valve timing variable mechanism 27, through an oil passage 30. When the key switch 41 of an engine 1 is operated from OFF to ON condition, an oil pressure control means 26 operates an oil supply passage 28 in non-connecting state with an oil return side (b), which passage 28 communicates with an oil passage 30 for the exhaust turbo type supercharger 10, while supplying the supercharger 10 with higher pressured oil from upper stream side (a) than the oil return part. This enables the ensuring of lubricating early the supercharger 10 to make a proper rotation when a turbine starts, and enables the avoiding of seizing to improve durability.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lubricating system for an engine with an exhaust turbocharger, which is equipped with an exhaust turbocharger and an oil pressure-operated variable valve timing mechanism. It is something.

(Prior art) Conventionally, for an exhaust turbo supercharger installed in the intake and exhaust system of an engine, since the turbine shaft rotates at high speed, the engine's lubricating oil is used for lubrication and cooling of the bearing part. For example, a structure designed to supply
It is publicly known as seen in Japanese Patent No. 7-107824.

In addition, there is also a technique in which a valve timing variable means for changing the cam phase is hydraulically provided on the camshaft of the engine, and the valve timing is changed by hydraulic control of the valve timing variable means, for example.
This is known as seen in JP-A No. 81-8249.

(Problem to be Solved by the Invention) However, in the above-mentioned system in which oil is supplied to the exhaust turbo supercharger and variable valve timing mechanism, when the engine key switch is turned on, In addition, there is a risk that the oil supply to the turbocharger will be insufficient.

In other words, when the engine is started, if the engine has been stopped for a long time, the lubricating oil in the bearing part of the exhaust turbo supercharger has leaked out, and oil is immediately supplied to the turbine shaft when it starts rotating. Good lubricity must be ensured.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a lubricating device for an engine with an exhaust turbo supercharger that can reliably lubricate the exhaust turbo supercharger when starting the engine. be.

(Means for Solving the Problems) In order to achieve the above object, the engine lubrication device of the present invention lubricates the bearing part of the turbine shaft of an exhaust turbo supercharger by supplying the lubricating oil. a variable valve timing mechanism that uses oil pressure as an operating source, and a hydraulic control means that changes the valve timing by switching the supply of oil pressure to the variable valve timing mechanism during a specific operation, An oil passage leading lubricating oil to the exhaust turbo supercharger is connected to the oil return part of the oil supply passage that supplies the oil to the exhaust turbo supercharger, and when the engine key switch is turned on, the hydraulic control means controls the exhaust turbo The oil supply passageway that communicates with the oil passageway for the type supercharger is configured to operate in a state where it is not connected to the oil return side.

(Function) In the above-mentioned lubrication system for an exhaust turbocharged engine, oil pressure is sent to the variable valve timing mechanism or connected to the oil return side based on the operation of the hydraulic control means depending on the operating state. The valve timing is changed to match each operating condition to improve output characteristics, fuel efficiency, etc., while a portion of the oil for the variable valve timing mechanism is transferred via an oil passage to exhaust turbo supercharging. It is supplied to the turbine to lubricate its turbine shaft. Furthermore, when the engine key switch is turned from the OFF state to the ON state, the hydraulic control means disconnects the oil supply passage that communicates with the oil passage for the exhaust turbocharger from the oil return side. This oil return section supplies oil with increasing pressure from upstream to the turbocharger, ensuring early lubrication of the turbocharger and ensuring good rotational conditions when the turbine is started. Also, the durability is improved by avoiding the occurrence of seizure and the like.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a schematic configuration of a supercharged engine equipped with a lubricating device according to an embodiment.

In the cylinder 1a of the engine 1, an intake boat 5 opened and closed by an intake valve 4 and an exhaust boat 7 opened and closed by an exhaust valve 6 are opened in a combustion chamber 3 formed above the piston 2. 8 is connected to the exhaust boat 7, and an exhaust passage 9 is connected to the exhaust boat 7.

An overhead intake side camshaft 11 for driving the opening and closing of the intake valve 4 of each cylinder 1a is provided, and
An overhead exhaust side camshaft 12 is provided to open and close the exhaust valve 6 of each cylinder 1a. Both camshafts 11, 12 have cam pulleys 1 installed at their respective ends.
3 and 1B through the timing belt 14 in synchronization with the rotation of the engine output shaft 15.

On the other hand, an air cleaner 18, an intake air amount sensor 19, and a throttle valve 20 are interposed in the intake passage 8 communicating with the intake boat 5 from the upstream side. is installed. This compressor 16 has a turbine shaft 17
A is connected to a turbine 17 installed in the exhaust passage 9, and supercharging of intake air is performed by rotation as the turbine 17 is rotationally driven by exhaust energy.

Furthermore, the intake passage 8 downstream of the throttle valve 20 is formed into an independent intake passage 8a whose downstream side of the surge tank 22 is connected to each cylinder 1a, and an injector 23 for injecting fuel into the independent intake passage 8a is disposed. has been done.

Furthermore, an intake side camshaft 11 for the intake valve 4
A variable valve timing mechanism 27 is installed in which changes the opening and closing timing of the valve timing mechanism 27 to change the closing timing of the intake valve 4.

The details of this variable valve timing mechanism 27 will be described later with reference to FIG.
8, and the oil feed passage 2
Three-way solenoid valve 29 (passage switching mechanism) in the middle of 8
is installed, and an actuation signal is output from the controller 36 to the three-way solenoid valve 29 according to the operating state, thereby forming a hydraulic control means 26 that switches between supplying hydraulic pressure to the variable valve timing mechanism 27 and opening the return. There is.

Further, a lubrication path for the bearing portion 25 of the turbine shaft 17a of the exhaust turbo supercharger 10 is connected. That is, the oil pump 24 is located upstream of the open portion of the return side of the three-way solenoid valve 29 of the oil supply passage 28 to the variable valve timing mechanism 27.
Branching from the side, the bearing part 25 of the exhaust turbo supercharger 10
An oil passage 30 is installed leading to the bearing part 25, and the oil that has passed through the bearing part 25 is returned to the oil pan 35 of the engine 1 through a return passage 30a.

A specific structural example of the three-way solenoid valve 29 is shown in FIG. 2, in which a spool valve 32 is inserted into a cylinder 31, and a return spring 33 is compressed at one end.
The rod 34a of the driving solenoid 34 is in contact with the other end of the return b that opens the C boat that communicates with the oil supply passage 28 for the variable valve timing mechanism 27 into the cylinder head according to the movement of the spool valve 32. C communicating with oil pump 24 for boat or engine lubrication
It is configured to switch communication to the port. Note that the d port is opened to the return side to allow movement of the spool valve 32. The solid line indicates the OFF state, and the chain line indicates the ON state. In the OFF state, the C boat and the B boat communicate, and no oil is supplied to the variable valve timing mechanism 27. On the other hand, in the ON state, the spool valve 32 As a result of this movement, the C-boats are brought into communication with the C-boats, and oil from the oil pump 24 is supplied to the variable valve timing mechanism 27, thereby introducing a predetermined hydraulic pressure.

Then, a drive signal is output from the engine controller 36 to the driving solenoid 34 of the three-way solenoid valve 29 according to the operating state, and as shown in FIG. An ON signal is output to the solenoid valve 29, and hydraulic pressure is introduced into the variable valve timing mechanism 27, and the closing timing ICI of the intake valve 4 is advanced and closed earlier as shown by the solid line I in FIG. It operates to increase the intake air filling efficiency. In other low load or high rotation areas B, an off signal is output to the three-way solenoid valve 29, the variable valve timing mechanism 27 is opened to the return side, and the fourth
As shown by the broken line ■ in the figure, the closing timing IC2 of the intake valve 4
is delayed so that it closes later.

The engine controller 36 receives, as engine load signals, a load signal from a throttle sensor 38, a water temperature signal from an oil temperature sensor 39 that detects oil temperature, and a rotation signal that detects engine rotation. On/off signals and the like from the sensor 40 and the engine key switch 41 are respectively input.

Further, the three-way solenoid valve 29 is provided with the engine 1
When the key switch 41 is activated from the off state to the on state, that is, at the time of starting, an on signal is output from the controller 36, and the oil supply passage 28 in the portion communicating with the oil passage 30 for the exhaust turbo supercharger 10 is turned on with oil. The return side is operated in a disconnected state, and is configured to supply oil with increasing pressure to the supercharger 10 from the upstream side of this oil return portion.

That is, as shown in FIG. 5, when the key switch 41 is turned on at point t1, an on signal is output to the three-way solenoid valve 29 from point t1. Then, while the engine 1 starts at point t2 due to cranking and the rotational speed increases, the oil pressure Pi to the bearing portion 25 rapidly increases due to the rotation of the oil pump 24.
The amount of oil supplied to the bearing portion 25 is ensured.

The operating condition immediately after engine startup is a low load region, and based on the operating region shown in FIG. 3, an off signal is output to the three-way solenoid valve 29 to control the intake valve 4 to close slowly. However, in a state where the oil pressure is low as described above, even if the ON signal is output, the variable valve timing mechanism 27 does not operate to close the intake valve 4 early but maintains a state where it closes late. Therefore, the oil pressure increases in response to the increase in engine speed, and t3 when the engine speed reaches the set rotation speed Ns.
At this point, the ON signal to the three-way solenoid valve 29 is stopped. This set engine rotation speed Ns at the time of stop is the sixth
As shown in the figure, it is set to increase as the oil temperature (water temperature) increases.

The duration of the ON signal to the three-way solenoid valve 29 when the engine key switch 41 is turned on as described above may be controlled by the engine rotation speed set to a fixed value, a predetermined time by a timer, or the like.

Next, the detailed structure of the variable valve timing mechanism 27 is as shown in FIG. A cam pulley 13 with which 14 is engaged is attached. This cam pulley 13 is connected to the spacer 5 at the tip of the boss portion 55 that is fixed to the unit.
The proximal end of the boss portion 55 is fixed to a cylindrical connecting member 56 rotatably attached to the intake camshaft 11. An inter-cam gear 57 is spline-coupled to the other end of the connecting member 56 and fixed by a lock nut 58. An inter-cam gear (not shown) fixed to the tip of the exhaust-side camshaft 12 is meshed and connected to the inter-cam gear 57 .

An annular piston 60 is installed inside the boss portion 55 of the cam pulley 13 and between it and the spacer 53 . The piston 60 has a structure in which it is divided into two parts in the axial direction, and both parts are fixed to each other by a plurality of pins 61 arranged at equal intervals in the circumferential direction. On the inside and outside of the piston 60 are helical splines 62 .in opposite directions.
63 is formed. A helical spline 64 is formed on the outside of the spacer 53 with respect to the spline 62 on the inside of the piston 60, and a boss portion 5 of the cam pulley 13 is formed with respect to the spline 63 on the outside of the piston 60.
5. A helical spline 65 is formed on the inner periphery. The piston 60 is urged toward the distal end side by a spring 66 installed between the piston 60 and the end surface of the connecting member 56.

An oil passage 67 is formed in the intake camshaft 11 along the axis. One end of this oil passage 67 is led out to the outside of the shaft, and communicates with the oil supply passage 28 which passes from the oil pump 24 through the three-way solenoid valve 29.

On the other hand, the cylindrical spacer 53 is fixed to the intake side camshaft 11 with a fixing bolt 69 via a stopper member 68. The fixing bolt 69 is provided with an axial through hole 70 that communicates with the oil passage 67. Furthermore, a pressure chamber 71 is provided at the tip of the boss portion 55 of the cam pulley 13 by a lid member 72 fixed thereto, facing the head of the piston 60 and guiding the hydraulic pressure from the oil passage 67 . Hydraulic pressure is introduced into these pressure chambers 71 via the oil passage 67, compressing the spring 66 and causing the piston 60 to
When the piston 60 moves in the axial direction, the spacer 53 and the cam pulley 13, which engage opposite splines 62, 63 formed on the inner and outer circumferences of the piston 60, rotate one relative to the other. As a result, the phase of the intake-side camshaft 11 and the cam pulley 13, which are integral with the spacer 53, ie, the valve timing changes. Note that a cover member 73 is disposed outside the variable valve timing mechanism 27.

The introduction control of the hydraulic pressure is performed by the three-way solenoid valve 29.
An engine controller 3 that outputs a drive signal to
6, this controller 3
6 determines the operating range (see Figure 3) of the variable valve timing mechanism 27 corresponding to the current operating state based on the engine load (e.g. throttle opening) and engine speed, and communicates the two three-way solenoid valves. It switches the state. Also, when the key switch 41 is turned on, the on signal is manually input as described above.

In the embodiment described above, the lubricity of the supercharger 10 is obtained when the key switch 41 is turned on, and the key switch 4
The lubricity during the OFF state of 1 is also improved.

That is, even if the key switch 41 is turned off and the engine 1 is stopped, the turbine 17 of the supercharger 10 continues to rotate for a while due to inertia, and in this state, as the oil pump 24 stops, the oil When the supply is stopped and the return is opened, the variable valve timing mechanism 2
7 oil pressure decreases, but the three-way solenoid valve 29
By branching the oil passage 30 to the supercharger 10 from the more upstream side, a sudden drop in oil pressure to the supercharger 10 is avoided and lubricity during inertial rotation is ensured.

Note that in the above embodiment, the introduction of hydraulic pressure to the variable valve timing mechanism 27 is switched on and off by the three-way solenoid valve 29;
Even if the operation between the on state and the off state is configured in the opposite manner to the above, it is sufficient that the key switch 41 is operated so as not to be connected to the return side when the key switch 41 is turned on.

Further, the variable valve timing mechanism 27 having the structure shown in FIG. 2 can be formed compactly, and in addition to making the phase of the intake valve 4 variable, it can also make the phase of the exhaust valve 6 variable in response to other requirements. good. Furthermore, the variable valve timing mechanism 27 can be changed to other hydraulically operated mechanisms as appropriate.

(Effects of the Invention) According to the present invention as described above, a hydraulic control means for changing the valve timing by switching the supply of oil pressure to the variable valve timing mechanism using oil pressure as an operation source is provided, and the variable valve timing mechanism An oil passage leading lubricating oil to the exhaust turbo supercharger is connected from upstream of the oil return part of the oil supply passage to the exhaust turbo supercharger, and when the engine key switch is turned on, the hydraulic control means By operating the oil supply passage that communicates with the oil passage in the oil return side in a state where it is not connected to the oil return side, pressure increases when the engine key switch is turned from the OFF state to the ON state. By supplying the same oil to the supercharger, it is possible to ensure early lubrication of the supercharger, thereby ensuring a good rotational state at the time of starting the turbine and preventing the occurrence of seizure, etc.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an exhaust turbo supercharged engine equipped with a lubricating device according to an embodiment of the present invention, and Fig. 2 is a sectional view of essential parts showing an example of the configuration of a variable valve timing mechanism and a three-way solenoid valve. , Fig. 3 is a characteristic diagram showing the control range of the variable valve timing mechanism, Fig. 4 is a characteristic diagram showing an example of changing the valve timing of the intake valve, and Fig. 5 is the relationship between oil pressure and engine speed at engine startup. FIG. 6 is a characteristic diagram showing the relationship between oil temperature and operating setting rotation speed. 1... Engine, 4... Intake valve, 6...
...Exhaust valve, 8...Intake passage, 9...
...Exhaust passage, 10...Exhaust turbo supercharger, 11.12...Camshaft, 16...
...Combusser, 17...Turbine, 17a...
... Turbine shaft, 24 ... Oil pump, 25 ... Bearing section, 26 ... Hydraulic pressure control means, 27 ... Valve timing variable mechanism , 28... Oil feed passage, 29...
・Three-way solenoid valve, 30...Oil passage, 36...Controller, 41...Key switch. Fig. 3 Engine fixed spear ( Fig. DC 8[) C C1 C2 Fig. Fig. Okin J Otsu L

Claims (1)

[Claims] (1) An exhaust turbo supercharger that lubricates the bearing portion of the turbine shaft by supplying lubricating oil, a variable valve timing mechanism that uses oil pressure from the lubricating oil as an operating source, and a variable valve timing mechanism that controls the variable valve timing mechanism during specific operations. In an exhaust turbo supercharged engine equipped with a hydraulic control means for changing valve timing by switching the supply of oil pressure, an oil return portion of an oil supply passage that supplies oil pressure to the variable valve timing mechanism. An oil passage that leads lubricating oil to the exhaust turbo supercharger from more upstream is connected, and when the engine key switch is turned on, the hydraulic control means controls the oil in the portion communicating with the oil passage for the exhaust turbo supercharger. A lubricating device for an engine with an exhaust turbo supercharger, characterized in that the feed passage is operated in a state where the feed passage is not connected to the oil return side.