JPH0643450Y2 - Engine lubricator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a lubricating device having an oil cooler in an oil supply passage to a lubricating system of a valve mechanism.

(Prior Art) In a lubrication system of a valve mechanism in which lubrication is mainly performed in a boundary lubrication region, the temperature of the oil is kept low, that is, the viscosity of the oil is kept high, and the affinity between the oil and the metal surface is increased to reduce friction. An oil cooler is installed in the oil supply passage to the lubrication system of the valve mechanism to reduce the oil lubrication effect, the oil bypasses the oil cooler during warm-up, and the oil passes through the oil cooler at high oil temperature. Thus, it is known to control the oil temperature.

However, even in the lubrication system of the valve operating mechanism, fluid lubrication occurs in the high rotation range, and the higher the oil temperature, that is, the lower the oil viscosity, the less the friction and the better the lubrication effect. There is a problem that if the oil temperature is lowered uniformly by passing through the oil cooler at high oil temperature, friction of the lubrication system of the valve train may increase. To solve this problem, for example, As disclosed in Japanese Patent No. 123812, an engine lubrication device has been developed in which oil is passed through an oil cooler at a speed lower than a predetermined speed, but the oil cooler is bypassed at a speed higher than the predetermined speed.

(Problems to be solved by the invention) However, in the conventional engine lubrication device, even if the oil temperature is changed according to the engine speed, the same temperature is applied to the lubrication system of the valve mechanism and the lubrication system of the crank mechanism. It is hard to say that proper lubrication was always performed in the lubrication system of the crank mechanism, which mainly uses fluid lubrication because oil was supplied, and switching between the oil cooler communication passage and the bypass passage was performed by hydraulic control. Therefore, there is a problem that it is difficult to accurately switch the oil temperature at a desired rotation speed.

The present invention is configured in view of the above problems, and can properly lubricate both the lubrication system of the valve mechanism and the lubrication system of the crank mechanism, and accurately switches the oil temperature at a desired rotational speed. An object of the present invention is to provide an engine lubrication device that can be used.

(Means for Solving the Problem) As a result of earnest studies to solve the above-mentioned problems, the present inventor has found that when a commonly used lubricating oil is used,
With a certain engine speed as a boundary, in the lubrication system of the valve operating mechanism, the lower the oil temperature is, the lower the frictional resistance is in the rotation range lower than the predetermined speed, and the higher the oil temperature is in the rotation range over the predetermined speed. On the other hand, in the lubrication system of the crank mechanism, the higher the oil temperature is, the lower the friction resistance is in the rotation region below the predetermined rotation number, and the lower the friction temperature is in the rotation region above the predetermined rotation number. It was found that the friction resistance is lower, and based on this finding, in a lubrication system that has an oil cooler in the oil supply passage to the lubrication system of the valve mechanism, a bypass passage that bypasses the oil cooler and a predetermined engine rotation speed are used. If the number is less than the specified number, the oil passage from the oil cooler is connected to the lubrication system of the valve mechanism, and the bypass passage is connected to the lubrication system of the crank mechanism, so that the specified engine speed is reached. Above, by providing a solenoid valve controlled by the engine speed for connecting the oil passage from the oil cooler to the lubrication system of the crank mechanism and the bypass passage to the lubrication system of the valve operating mechanism, The above-mentioned object is achieved. That is, the present invention is based on the following experimentally obtained knowledge.

2 and 3 show experimentally obtained average friction effective pressures and engine speeds of the lubrication system of the valve mechanism and the lubrication system of the crank mechanism, which were experimentally obtained using commonly used lubricating oil. It is a correlation diagram and shows the case where the oil temperature is 70 degrees and the case where the oil temperature is 100 degrees. As can be seen from FIG. 2, in the lubrication system of the valve mechanism, the oil temperature is 70 degrees in the lower rotation range and the oil temperature is higher in the higher rotation range with the engine speed near 5000 rpm as the boundary. The average effective frictional pressure is lower when the temperature is 100 degrees. That is, there is little loss of engine output due to friction. This is because, in the lubrication system of the valve train, since the surface pressure between the lubricated members is high, lubrication is mainly performed by boundary lubrication, but in the high rotation speed region, fluid lubrication occurs due to the formation of an oil film. is there. on the other hand,
As can be seen from FIG. 3, in the crank mechanism lubrication system,
With 5000 rpm as the boundary, the oil temperature is 100 at lower speeds.
The average effective frictional pressure is lower when the oil temperature is 70 degrees in the higher rotation range. This is because in the lubrication system of the crank mechanism, the surface pressure between the members to be lubricated is relatively low, so the lubrication is mainly performed by fluid lubrication, but in the high rotational speed range, the inertial force of the moving parts such as the cylinder and the connecting rod is large. This is because the surface pressure between the members to be lubricated becomes high and the boundary lubrication tends to occur due to the increase. Therefore, with the engine speed near 5000 rpm as the boundary, in the lower rotation range, low temperature oil is supplied to the lubrication system of the valve mechanism and high temperature oil is supplied to the lubrication system of the crank mechanism. In the higher rotation range, high temperature oil is supplied to the lubrication system of the valve mechanism,
On the other hand, by supplying low temperature oil to the lubrication system of the crank mechanism, the lubrication system of the valve mechanism and the lubrication system of the crank mechanism can be properly lubricated. Also, by using a solenoid valve controlled by the engine speed,
The oil temperature can be switched around the rpm.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a system diagram of an engine lubricating device according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 is a pump for pumping lubricating oil, a suction port 4 for sucking up the lubricating oil accumulated in an oil sump 3 of an engine 2 is provided upstream of the pump 1, and a downstream of the pump 1. Is connected to the filter 5, and the downstream side of the filter 5 is a passage 7 passing through the oil cooler 6,
It is arranged in parallel with the passage 7 and is connected to a bypass passage 8 that does not pass through the oil cooler 6. Passage 7 and bypass passage 8
The downstream side of is communicated with the lubrication system of the valve mechanism or the lubrication system of the crank mechanism via a solenoid valve 9 controlled by an engine speed signal from an engine speed sensor (not shown). The solenoid valve 9 includes a passage 9a connecting the passage 7 and the bypass passage 8 to the lubrication system of the valve mechanism and the lubrication system of the crank mechanism, and the passage 7 and the bypass passage 8 to the crank lubrication system and the valve mechanism, respectively. It has a passage 9b connected to the lubrication system, and the solenoid 10 allows passages 9a and 9b.
It is configured to switch between and. Downstreams of the lubrication system of the valve mechanism and the lubrication system of the crank mechanism communicate with the oil reservoir 2, respectively.

On the other hand, 11 is a radiator of an engine cooling water system, a passage 12 for guiding hot water after cooling the engine 2 is arranged upstream of the radiator 11, and a bypass passage for bypassing the radiator 11 is provided in the passage 12. 13 are connected.
Downstream of the radiator 11 and the bypass passage 13, when the cooling water temperature is lower than a predetermined value, the cooling water is passed through the bypass passage 13,
If the cooling water temperature is higher than the specified value, cool the cooling water with the radiator 11
Is connected to a water pump 15 via a thermostat 14 that forms a three-way valve for passing through the water pump 15. The water pump 15 is in communication with the engine 2 that is a cooling target. Further, a passage 16 branched from the intermediate region between the thermostat 14 and the water pump 15 communicates with the oil cooler 6 to supply cooling water to the oil cooler 6, and a passage 17 connects the oil cooler 6 and the downstream of the water pump 15 to each other. is doing.

The engine lubrication device according to the present embodiment having the above structure operates as follows. That is, when the engine speed is less than 5000 rpm, the solenoid 10 controlled by the speed signal from the engine speed sensor (not shown) is used.
Operates to connect the passage 9a of the solenoid valve 9 to the passage 7 and the bypass passage 8. As a result, low-temperature oil that has passed through the oil cooler 6 is supplied to the lubrication system of the valve mechanism, and high-temperature oil that bypasses the oil cooler 6 is supplied to the lubrication system of the crank mechanism. On the other hand, when the engine speed is 5000 rpm or more, the solenoid 10 controlled by the speed signal from the engine speed sensor (not shown) is activated to connect the passage 9b of the solenoid valve 9 to the passage 7 and the bypass passage 8. To do. As a result, low-temperature oil that has passed through the oil cooler 6 is supplied to the lubrication system of the crank mechanism, and high-temperature oil that bypasses the oil cooler is supplied to the lubrication system of the valve mechanism.

As described above, in the lubricating device according to the present embodiment, the lubricating oil of the proper temperature is supplied to the lubricating system of the valve mechanism and the lubricating system of the crank mechanism in accordance with the number of revolutions of the engine. Proper lubrication of the system is guaranteed. Further, since the temperature switching of the oil supplied to the lubrication system of the valve mechanism and the lubrication system of the crank mechanism is controlled by the engine speed, the accuracy of the oil temperature switching timing is ensured.

FIG. 4 is a system diagram of an engine lubricating device according to another embodiment of the present invention.

The lubrication system according to the present embodiment does not have the passage 16 that connects the oil cooler 6 with the intermediate basin between the thermostat 14 and the water pump 15, but instead has the intermediate basin between the radiator 11 and the thermostat 14 and the oil cooler 6. A passage 18 that communicates with and is provided, is controlled in the middle of the passage 18 by an oil temperature signal from an oil temperature sensor (not shown), is closed when the oil temperature is less than 70 degrees, and the oil temperature is 70 degrees or more. In the case of the above, the control valve 19 is opened, which has the same structure as the embodiment of FIG. In this embodiment, in the embodiment shown in FIG.
Since the cooling water is guided from the downstream of the thermostat 14 to the oil cooler 6, when the engine cooling water temperature is high, such as when the engine enters an idling state after traveling,
In view of the fact that the oil may not be cooled to a temperature below the set temperature of the thermostat 14, cooling water from the radiator 11 can be made to flow to the oil cooler 6 regardless of the set temperature of the thermostat 14 of the engine cooling water system. It is a thing. However, considering that it is actually difficult to further cool the oil when the oil temperature is less than 70 degrees, the control valve 19 is provided on the way of the cooling water supply passage to the oil cooler 6, and the oil temperature is 70 degrees. In the case of less than, the supply of cooling water to the oil cooler 6 is stopped. Except for the above points, the operation of the lubricating device according to the embodiment of FIG. 2 is the same as that of the lubricating device according to the embodiment of FIG.

According to the present embodiment, in addition to the effect of the embodiment of FIG. 1, there is an effect that the oil can be sufficiently cooled even when the temperature of the cooling water is high in the case of shifting to the idling state after traveling.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the scope of claims for utility model registration. Needless to say.

(Effects of the Invention) According to the present invention, the lubrication system for the valve mechanism and the lubrication system for the crank mechanism can be properly lubricated, and the oil temperature can be switched accurately at the desired rotation speed. Will be provided.

[Brief description of drawings]

FIG. 1 is a system diagram of an engine lubricating device according to an embodiment of the present invention. FIG. 2 is a correlation diagram between the average effective friction pressure of the lubrication system of the valve mechanism and the engine speed, obtained experimentally by using a commonly used lubricating oil. FIG. 3 is a correlation diagram between the average friction effective pressure of the lubrication system of the crank mechanism and the engine speed, obtained experimentally by using a commonly used lubricating oil. FIG. 4 is a system diagram of an engine lubricating device according to another embodiment of the present invention. 6 ... Oil cooler, 7 ... Oil supply passage, 8 ... Bypass passage, 9 ... Solenoid valve, 10 ... Solenoid, 11 ... Radiator, 14 ... Thermostat, 19 ... Control valve.

Claims (1)

[Scope of utility model registration request] 1. A lubrication device having an oil cooler in an oil supply passage to a lubrication system of a valve operating mechanism, wherein a bypass passage bypassing the oil cooler and an oil passage from the oil cooler are operated below a predetermined engine speed. The bypass passage is connected to the lubrication system of the valve mechanism, the bypass passage is connected to the lubrication system of the crank mechanism, and the oil passage from the oil cooler is connected to the lubrication system of the crank mechanism and the bypass passage is operated at a predetermined engine speed or higher. And a solenoid valve controlled by the engine speed for connecting to the lubrication system of the engine.