JPH02271019A - Lubricating device of internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lubricating device that controls the amount of lubricating oil supplied to sliding parts of an internal combustion engine according to temperature.

(Prior Art) A lubricating device for an internal combustion engine that controls the amount of lubricating oil supplied to each sliding part according to the engine speed and load is disclosed in, for example, Japanese Patent Laid-Open No. 61-212618. There is.

As shown in FIG. 4, the lubricating oil from the oil tank 1 storing lubricating oil is transferred from the injection nozzle 12 via the oil passages 2a and 2b by the oil pump 3 to the intake boat 13 downstream of the reed valve 11. is injected into the combustion chamber 17 from the scavenging boat 1.4 together with the air-fuel mixture that is sucked in according to the opening degree of the throttle valve 10, and is sent into the combustion chamber 17 from the scavenging boat 1.4.
It is designed to lubricate the sliding surfaces of the

The supply amount of lubricating oil matches the discharge amount of the oil pump 3, but in order to control this discharge amount, the oil pump 3 is synchronized with the engine rotation by a worm 4 that meshes with a gear 5 attached to the crankshaft 6. and the flow rate control lever 9 is interlocked with the throttle valve 10.

Therefore, the amount of lubricating oil sprayed into the air-fuel mixture in the intake boat 13 increases as the engine speed increases, and as the throttle opening (load) increases.

In addition, in the figure, 7 is the crank case, 15 is the exhaust boat, 1
6 indicates a spark plug.

(The problem to be solved by the invention!)However, if the amount of lubricant to be supplied to the engine's sliding parts is determined in this way only according to the engine speed and throttle opening, the lubricant may change depending on the operating conditions. This could lead to wear and seizure due to lack of lubricating oil.

For example, if you have been driving at high rpm and high load for a long time, and then the rpm and load suddenly drop (such as when you drive up a steep slope for a long time and then move to a gentle downhill slope), Even though the temperature of each sliding part is extremely high, the amount of lubricant supplied decreases rapidly.
The amount of lubricating oil in the sliding parts is temporarily insufficient, leading to severe wear and, in severe cases, seizing.

The present invention aims to solve such problems by making the supply amount correspond to the actual required characteristics of lubricating oil.

Means for Solving the Problems> Therefore, the present invention provides means for controlling the flow rate of lubricating oil supplied to sliding parts of an internal combustion engine, means for detecting the temperature of the sliding parts, and means for detecting the engine rotation speed. means for detecting the supply amount of lubricating oil; and means for setting the supply flow rate of lubricating oil based on the detected temperature and rotation speed, and adjusting the flow rate so that the set flow rate and the detected supply amount match. It is equipped with a controller that performs feedback control of the control means.

(Operation) Therefore, the amount of lubricating oil supplied to each sliding part is controlled according to the engine speed and the temperature of the sliding part.

In other words, if the rotation speed is high, the supply amount will increase, and if the temperature rises, the supply amount will also increase accordingly.
As a result, an appropriate amount of lubricating oil is supplied to the sliding parts according to the required amount of lubricating oil, and even when switching to low-load operation after a long period of high-output operation, seizure of the sliding parts can be prevented. It can definitely be avoided.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a controller 20 is provided to control the discharge amount of the oil pump 3 that feeds lubricating oil to the sliding parts of the engine, and this controller 20 basically includes the following:
The rotation speed signal from the crank angle sensor 21 as a means for detecting the engine rotation speed and the temperature signal from the cylinder wall temperature sensor 22 as a means for detecting the temperature of the sliding parts of the engine are input, and furthermore, the actual A flow rate signal is input from a flow rate sensor 30 as a means for detecting the amount of lubricating oil supplied, and based on these, the controller 20 optimally sets the amount of lubricating oil supplied according to the rotation speed and temperature, and also adjusts the actual amount of lubricating oil supplied. The discharge amount of the oil pump 3 is feedback-controlled so that the supply amount matches this set flow rate.

Basically, the controller 20 increases the supply amount of lubricating oil as the engine speed increases, and also increases the supply amount as the temperature of the sliding part increases.
A flow control means (not shown) of the oil pump 3 is driven and controlled.

In a two-stroke engine like this embodiment, the temperature sensor 22 is installed near the exhaust boat 15 in the cylinder bore, which is the part where the lubrication conditions are most severe.

By the way, the flow rate sensor 30 for detecting the actual supply amount of lubricating oil is constructed as shown in FIG. 2 in this embodiment.

This flow rate sensor 30 measures the flow rate by interposing a means for heating or cooling the lubricating oil in a part of the oil passage and detecting the temperature before and after the means, and measures the flow rate of the lubricating oil flowing according to the flow rate. It takes advantage of changes in temperature distribution.

For this purpose, two temperature sensors 31 and 32 are arranged at a predetermined interval in the oil passage 2+), and two temperature control elements 33 and 34 are also arranged at a predetermined interval. Note that the temperature sensors 31 and 32 are arranged at equal positions upstream and downstream of the temperature control element 33.

The temperature control elements 33 and 34 are elements that heat or cool the lubricating oil flowing through the oil passage 2b, and are composed of, for example, a heater element or an electronic cooling element using the Beltier effect.

As shown in FIG. 3, when a temperature control element 33 for heating or cooling is interposed in a part of the flow path and the temperature of the fluid before and after it is measured, a phase occurs in the temperature distribution depending on the flow velocity of the fluid. . The solid line in the figure shows the temperature distribution when there is no flow (flow velocity is zero), and the dotted line shows the temperature distribution when flowing at a certain speed. Therefore, by measuring the fluid temperature at a predetermined position on the upstream or downstream side when there is a flow and when there is no flow, from the temperature difference 1+ and t2, the flow rate of the fluid can be determined.
In other words, the flow rate can be measured.

In this case, in order to maintain a predetermined measurement accuracy, it is necessary to maintain the temperature of the fluid within a range of 15 to 35°C, but in the case of an internal combustion engine, the ambient temperature tends to be high, so Another temperature control element 34 is installed to cool the fluid to maintain the predetermined temperature range.

The structure is as described above, and other parts that are the same as those in FIG. 4 are given the same reference numerals, and the operation will be explained next.

The controller 20 controls the discharge amount of the oil pump 3 based on the detected engine speed and the temperature of the sliding part.

Therefore, as the engine speed increases, the amount of lubricating oil supplied increases, and similarly, as the temperature of the sliding portion increases, the amount of lubricating oil supplied increases.

The lubricating oil is drawn into the engine through the oil injection nostle 12 through the oil passage 2b together with the air-fuel mixture in the intake port 13.
Lubricate the sliding surface of the piston 8.

The actual amount of lubricating oil supplied is measured by the flow sensor 3o, and the measured value is fed back to the controller 2o. The controller 2o compares the actual supply amount with a set value depending on the operating state, and corrects the discharge amount of the oil pump 3 so that the two correctly match.

In this way, the amount of lubricating oil supplied is controlled according to the engine speed and the temperature of the sliding parts, so it is possible to always maintain an appropriate flow rate for the required amount, and the wear of the sliding parts It can effectively prevent burn-in.

In particular, as the temperature of the sliding parts increases, the required supply amount of lubricating oil increases, but if the lubricating oil supply amount is controlled by engine load rather than temperature as in the past,
Although this is true during steady operation, when operating conditions fluctuate, the actual temperature of the sliding parts often does not correspond to the engine load, making it easy for the supply of lubricating oil to be in excess or insufficient.

In contrast, with the present invention, for example, even if the load or rotation speed suddenly decreases immediately after long-term high-output operation,
If the temperature of the actual sliding part is extremely high, a large amount of lubricating oil will continue to be supplied until the temperature drops, so unlike conventional methods, the lubricating oil supply amount will be rapidly reduced and seizure will occur. It can be prevented.

In addition, even when the accelerator is temporarily depressed, such as when the engine temperature is low, the amount of lubricant supplied does not increase because the temperature is low, eliminating the waste of supplying unnecessary lubricating oil and reducing oil consumption. You can also do it.

Although this embodiment exemplifies a dry sump type lubrication device that lubricates the sliding parts of the engine by mixing lubricating oil into the air-fuel mixture, the present invention is not limited to this. Of course, it can also be applied to a type that forcibly feeds lubricating oil into the area.

(Effects of the Invention) As described above, according to the present invention, the supply amount of lubricating oil is feedback-controlled according to the engine speed and the temperature of the sliding parts, so that it can be used under all engine operating conditions. This allows the proper amount of lubricating oil to be supplied in accordance with the actual required characteristics of the lubricating oil, so even if the load or rotation speed suddenly decreases immediately after high-output operation, the sliding There is no shortage of lubricating oil in the parts, and wear and seizure can be reliably prevented.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram of a flow sensor, Fig. 3 is a temperature characteristic diagram showing the measurement principle of the flow sensor, and Fig. 4 is a block diagram of a conventional device. . 1. Oil tank, 2a, 2b... Oil passage, 3... Oil pump, 8... Piston, 20...
Controller 1 - roller, 21... crank angle sensor, 22
...Temperature sensor, 30...Flow rate sensor. Figure 11 Figure 3

Claims (1)

[Claims] means for controlling the flow rate of lubricating oil supplied to sliding parts of an internal combustion engine; means for detecting the temperature of the sliding parts; means for detecting engine rotational speed; and means for detecting the amount of lubricating oil supplied. ,
The present invention is characterized by comprising a controller that sets the supply flow rate of lubricating oil based on the detected temperature and rotation speed, and performs feedback control of the flow rate control means so that the set flow rate and the detected supply amount match. Lubrication system for internal combustion engines.