JPH11229840A - Engine lubrication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to supply lubricating oil to the engine balancer via a high-speed relief duct to improve the cooling of the engine balancer by providing a high-speed relief duct connected to the oil pump discharge port via a switching valve, and also connected to the engine balancer. SOLUTION: An electromagnetic valve 12 is disposed between an oil cooler 3 and a relief valve 2 that is interposed in the discharge circuit of an oil pump 1 driven by the engine. A high-speed relief duct 14 is connected to the electromagnetic valve 12. The high-speed relief duct 14 allows oil to be supplied to an engine balancer 5 via an oil cooler and an oil filter 16. The electromagnetic valve 12 is controlled by a controller 13 based on output signals from an engine speed sensor 16. For example, when the controller judges that the engine speed has reached 3000 rpm, the controller controls the opening/closing of the electromagnetic valve 12 such that it switches to the actuating position 12b. Oil is then supplied to the balancer 5 via the high-speed relief duct thus cooling the balancer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lubrication system for an engine.

[0002]

2. Description of the Related Art For example, an engine balancer is frequently used to realize low vibration and low noise in an engine for a passenger car or the like.

FIG. 1 shows an engine lubrication system according to the prior art. The oil pump 1 is operated by driving a pulley 1 a by a belt (not shown).
Via oil cooler 3 and oil filter 4
The lubricating oil is supplied to the engine balancer 5, the valve train 6, the cylinder bore and the piston 7, and the crankshaft 8.

The lubricating oil supplied to the engine balancer 5, valve train 6, cylinder bore and piston 7, and crankshaft 8 is returned to the oil pan 9 after cooling them.

In the engine lubrication system shown in FIG. 1, the discharge pressure of the lubricating oil from the oil pump 1 becomes high when the engine rotates at a high speed. A part of the lubricating oil is returned to the oil pan 9 via the relief passage 10.

[0006] The engine balancer 5 is often set to rotate at twice the rotation speed of the engine. Therefore, the bearing portion of the balancer 5 tends to be heated to a high temperature by high-speed rotation, and requires a large amount of lubricating oil for cooling. However, as shown in FIG. 1, in the conventional engine lubrication system, the lubricating oil supplied to the engine balancer does not increase so much even when the engine is rotating at a high speed, and the lubricating oil is supplied to the bearing portion of the engine balancer to prevent seizure. However, it is necessary to use a bearing material having good seizure resistance, which is expensive.

In order to solve this problem, conventionally, measures such as increasing the size of the oil pump or increasing the speed have been taken.

[0008] Alternatively, the engine lubrication device disclosed in Japanese Patent Publication No. 7-116929 is provided with two oil pumps, a feed pump and an oil cooler pump, in order to improve the cooling performance.

In any case, the lubricating device described above has a problem in that the driving horsepower of the oil pump increases and the fuel efficiency of the vehicle deteriorates.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine lubrication system having good cooling of an engine balancer.

[0011]

According to a first aspect of the present invention, there is provided an oil pump for sucking lubricating oil from an oil pan and discharging the lubricating oil from a discharge port. A steady lubrication passage connected to the discharge port and communicating with the system to be cooled including the engine balancer; and a high-speed relief connected to the discharge port of the oil pump via a switching valve and connected to the engine balancer. An engine lubrication system comprising a passage and a controller that switches the switching valve based on a state of the engine.

According to a second aspect of the present invention, when the engine rotation speed reaches a predetermined value,
The switching valve is switched so that the discharge port of the oil pump communicates with the high-speed relief passage from the state where the discharge port of the oil pump is cut off from the high-speed relief passage. Item 1 was an engine lubrication system.

According to the engine lubrication system of the first aspect, the high-speed relief passage connected to the discharge port of the oil pump via the switching valve and to the engine balancer is provided. Since lubricating oil can be supplied to the engine balancer via the relief passage, the cooling performance of the engine balancer can be improved.

Further, according to the engine lubrication system of the second aspect, when the engine rotation speed reaches a predetermined value, the discharge port of the oil pump is brought into a state of communicating with the high-speed relief passage. Since the switching valve is switched, the cooling performance of the engine balancer during high-speed rotation of the engine can be improved.

[0015]

FIG. 2 is a system diagram of a first embodiment of an engine lubrication system according to the present invention, and FIG.
Is a system diagram of the second embodiment. Hereinafter, only a configuration different from FIG. 1 will be described.

In FIG. 2, the solenoid valve 12 is a relief valve 2
The oil cooler 3 is provided between the relief valve 2 and the oil cooler 3. Solenoid valve 12
, A high-speed relief passage 14 is connected, and the solenoid valve 12 is connected to the engine balancer 5 via the oil cooler 15 and the oil filter 16 by the high-speed relief passage 14.

A controller 13 is connected to the solenoid valve 12, and its opening and closing are controlled by the controller 13. For example, a signal from a rotation speed sensor 16 of the engine is input to the controller 13.

When the rotational speed of the engine is, for example, less than 3000 rpm, the controller 13 does not generate a switching signal for the solenoid valve 12, so that the solenoid valve 12 is in the steady position 12a and the relief valve 2 is connected to the oil cooler 3 only. Is communicated to. Therefore, the lubricating oil discharged from the oil pump 1 passes through the relief valve 2, the solenoid valve 12, the oil cooler 3, and the oil filter 4, through the engine balancer 5, the valve train 6, the cylinder bore and the piston 7, and the crankshaft. 8.

When the controller 13 determines that the rotation speed of the engine has reached 3000 rpm, the controller 13 sends an operation signal to the solenoid valve 12 to switch the solenoid valve to the operating position 12b. Therefore, the relief valve 2 maintains communication with the oil cooler 3 and also communicates with the oil cooler 15 via the high-speed relief passage 14. Therefore, the lubricating oil discharged from the oil pump 1 passes through the relief valve 2, the solenoid valve 12, the oil cooler 3, and the oil filter 4, through the engine balancer 5, the valve train 6, the cylinder bore and the piston 7, and the crankshaft. 8 and the oil cooler 15 and the oil filter 1
6, the power is also supplied to the engine balancer 5.

The controller 13 receives not only the signal from the engine rotational speed sensor 16 but also a signal from an oil temperature sensor 17 in a cylinder block (not shown) as described above. Valve 12
May be controlled to open and close.

The second embodiment of the engine lubrication system of the present invention shown in FIG. 3 is different from that of FIG. 2 in that the high-speed relief passage 14 is provided in the oil cooler 3 and the oil filter 4. Thus, the oil cooler 3 and the oil filter 4 are covered by one each.

[0022]

As described above, according to the present invention, an existing engine lubrication system can be configured by adding at least a switching valve and a controller to an existing engine lubrication system. Can be configured.

[Brief description of the drawings]

FIG. 1 is a system diagram of a conventional engine lubrication system.

FIG. 2 is a system diagram of an engine lubrication system according to the first embodiment of the present invention.

FIG. 3 is a system diagram of an engine lubrication system according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Oil pump 5 Engine balancer 9 Oil pan 12 Solenoid valve 13 Controller 14 High speed relief passage 15 Steady lubrication passage 16 Engine rotation speed sensor

Claims (2)

[Claims] An oil pump for sucking lubricating oil from an oil pan and discharging the lubricating oil from a discharge port, and a steady lubrication connected to a discharge port of the oil pump and communicating with a system to be cooled including an engine balancer. And the oil pump is connected to a discharge port of the oil pump through a switching valve.
A high-speed relief passage connected to the engine balancer;
An engine lubrication system comprising a controller that switches the switching valve based on a state of the engine. 2. The controller according to claim 1, wherein when the engine speed reaches a predetermined value, the discharge port of the oil pump communicates with the high-speed relief passage from a state in which the discharge port of the oil pump is disconnected from the high-speed relief passage. The engine lubrication system according to claim 1, wherein the switching valve is switched so as to be in a set state.