JPH05240015A - Lubricating oil supply device for two-cycle engine - Google Patents

Abstract

PURPOSE:To reduce the supply error of oil when the oil is being under the conditions of low temperature and high viscosity by providing a lubricating oil supply amount correction means with a control device which controls the lubricating oil supply amount for increasing the supply amount when a lubricating oil temperature is lower than a preset value. CONSTITUTION:A lubricating oil supply device 1 is composed of a lubricating oil pump 3, a three-directional solenoid valve 4 on its discharge side, a lubricating oil tank 5 on its suction side, a lubricating oil temperature sensor 6, and a control unit 7. When a temperature detected by the lubricating oil temperature sensor 6 is lower than a set value, the control unit 7 is operated for controlling the three-directional solenoid valve 4 according to a correction duty ratio larger than that corresponding to the engine operation condition at that time. The lubricating oil supply amount is increased by a preset amount compared to a proper amount corresponding to the operation condition when the oil is being under the conditions of a low temperature and high viscosity, so that supply error is reduced, and the supply amount is set correspondingly the operation conditions of the engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with a control device for controlling a lubricating oil supply amount to an amount adapted to an engine operating condition.
The present invention relates to a lubricating oil supply device for a cycle engine.

[0002]

2. Description of the Related Art Conventionally, as a lubricating oil supply device for a two-cycle engine, a lubricating oil pump consisting of an engine-driven plunger pump having a discharge amount according to the engine speed is adopted, and for example, a characteristic line a in FIG. As shown
A device is generally used in which the plunger stroke of the lubricating oil pump is changed according to the accelerator opening to control the discharge amount of the pump itself along the engine output curve b.

However, in this conventional lubricating oil supply device,
For example, when the accelerator is widely opened and accelerated from a low speed running state, the plunger stroke becomes unnecessarily large as shown by the characteristic line c in FIG. 5, so that the lubricating oil is excessively supplied to the engine and eventually the engine operating state It is difficult to control the amount of lubricating oil used.

Therefore, as a device capable of supplying lubricating oil with a supply amount suitable for the operating condition of the engine, a return passage is connected to the lubricating oil supply passage, and the connection portion is provided on either the supply passage side or the return passage. There has been proposed a lubricating oil supply device in which a three-way solenoid valve that closes the other when it is opened is provided and the duty of this solenoid valve is controlled (for example, see JP-A-2-139307).

[0005]

However, even if the duty of the three-way solenoid valve is controlled as described above, the amount of lubricating oil supplied cannot always be made to correspond to the operating state of the engine.

It is considered that this is because the temperature of the lubricating oil changes according to the outside air temperature. That is, since the viscosity of lubricating oil increases as the temperature decreases, there is a difference in the discharge amount of the lubricating oil pump between low temperature and high temperature.
Further, the lubricating oil supply error when the temperature of the lubricating oil is low is that the duty ratio in the duty control is small and the lubricating oil supply time becomes short because the lubricating oil of high viscosity cannot change the flow direction rapidly. Sometimes, it also increases, and it also increases as the engine speed increases. FIG. 6 shows the relationship between the lubricating oil temperature, the duty ratio, the engine speed and the supply error rate. In FIG. 6, the solid line shows the supply error rate with respect to the lubricating oil temperature, the broken line shows the supply error rate with respect to the duty ratio, and the alternate long and short dash line shows the supply error rate with respect to the engine speed. The supply error rate with respect to the duty ratio and the engine speed is when the lubricating oil temperature is low.

[0007]

The present invention has been made in view of the phenomenon that the supply error increases when the temperature of the lubricating oil is low. The lubricating oil supply device for a two-cycle engine according to the present invention is a lubricating oil supply device. A lubrication oil pump for supplying the two-cycle engine to the two-cycle engine, and a control device for controlling the lubrication oil supply amount to an amount adapted to the engine operating state.
Lubricating oil supply amount correction means for increasing the lubricating oil supply amount by a predetermined amount from the operation state adaptation amount when the lubricating oil temperature for detecting the viscosity of the lubricating oil is lower than a predetermined temperature. ..

[0008]

When the lubricating oil temperature is lower than the predetermined temperature, the amount of lubricating oil supplied to the engine is increased more than the operating condition conforming amount.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a schematic configuration diagram of a lubricating oil supply device for a two-cycle engine according to the present invention, FIG. 2 is a block diagram of a control device used in the lubricating oil supply device for a two-cycle engine according to the present invention, and FIG. 3 is for the present invention. FIG. 4 is a flow chart showing the operation of the lubricating oil supply device for such a two-cycle engine, and FIG. 4 is a graph showing the relationship between the correction amount and the lubricating oil temperature, duty ratio, and engine speed.

In these figures, 1 is 2 according to the present invention.
It is a lubricating oil supply device for a cycle engine. The lubricating oil supply device 1 communicates with a lubricating oil pump 3 driven by a two-cycle engine 2, a three-way solenoid valve 4 connected to the discharge side of the lubricating oil pump 3, and a suction side of the lubricating oil pump 3. Lubricating oil tank 5, a lubricating oil temperature sensor 6 attached to the lubricating oil pump 3, and the three-way solenoid valve 4
And a control unit 7 for controlling the duty of the.
The lubricating oil temperature sensor 6 has a detecting portion facing a lubricating oil sump (not shown) in the lubricating oil pump 3, and the lubricating oil pump 3
It is configured to detect the temperature of the lubricating oil flowing therein.

The lubricating oil pump 3 comprises a plunger pump in which a plunger (not shown) is driven by an engine, and the plunger stroke can be adjusted so that the reciprocating stroke increases as the throttle opening increases. There is.

The three-way solenoid valve 4 has a lubricating oil outlet side communicated with the engine 2 via a lubricating oil supply passage 4a and a lubricating oil tank 5 via a lubricating oil return passage 4b, and is incorporated therein. Both paths 4a by solenoid
4b is switched. Solenoid O
The N and OFF operations are controlled by a control unit 7 described later. When the solenoid is in the ON state, the three-way solenoid valve 4 is switched to the lubricating oil return passage 4b side, and in the OFF state, it is switched to the lubricating oil supply passage 4a side. It is configured.

That is, when the three-way solenoid valve 4 is energized, the lubricating oil is flown into the lubricating oil tank 5, and when the energization is cut off, the lubricating oil is supplied to the engine 2.

The control unit 7 is configured to duty-control the three-way solenoid valve 4 by energizing or de-energizing the three-way solenoid valve 4 according to a predetermined duty ratio. It should be noted that the duty ratio referred to here is the lubricating oil supply time in the state where the lubricating oil supply passage 4a is switched to,
It is calculated by dividing the lubricating oil supply time by the control cycle including the lubricating oil return time in the state where the lubricating oil return passage 4b is switched. That is, the time when the three-way solenoid valve 4 is OFF (the time when the lubricating oil is supplied to the engine 2) is the OFF time, and the time when the three-way solenoid valve 4 is ON (the lubricating oil is returned to the lubricating oil tank 5). When the time) is the ON time, the duty ratio (%) = [OFF time / (ON time + OFF time)] × 100.

The control unit 7 is connected to a battery 9 via a main switch 8 as shown in FIG. 2, and is also connected to an ignition device 10 of the engine 2 for calculating the rotation speed of the engine 2. Further, a rotational speed calculating means 11, a throttle opening calculating means 12, a lubricating oil temperature detecting means 13, a microcomputer 14, a supply amount correcting means 15 and the like which will be described later are incorporated.

The rotation speed calculation means 11 is an ignition device 10.
The engine speed is calculated based on the ignition signal input from the engine, and the engine speed signal is output to the microcomputer 14. The throttle opening calculation means 12 is configured to calculate the throttle opening from the opening / closing position of the throttle 16 and output a throttle opening signal to the microcomputer 14.

The lubricating oil temperature detecting means 13 is configured to output a lubricating oil temperature signal to the microcomputer 14 based on the lubricating oil temperature detected by the lubricating oil temperature sensor 6.

The microcomputer 14 stores a duty ratio map (not shown) in which a duty ratio which is the most suitable lubricating oil supply amount for the engine operating condition (hereinafter, this supply amount is referred to as operating condition adapting amount) is recorded. I have it.
Then, the microcomputer 14 reads the duty ratio corresponding to the engine speed and the throttle opening input from the rotation speed calculating means 11 and the throttle opening calculating means 12 from the duty ratio map to set the lubricating oil temperature. When the temperature is higher than the temperature, the duty of the three-way solenoid valve 4 is controlled according to the duty ratio. The above-mentioned set temperature of the lubricating oil temperature is a temperature at which the influence of the viscosity of the lubricating oil is reduced as much as possible, and is set to a constant temperature.

When the lubricating oil temperature detected by the lubricating oil temperature sensor 6 is lower than the set temperature, the supply amount correcting means 15 calculates the correction amount from the lubricating oil temperature, the duty ratio and the engine speed, and at that time. Engine speed,
The correction duty ratio is calculated by adding the correction amount to the duty ratio corresponding to the throttle opening.

In order to obtain the correction amount, the lubricating oil temperature, the duty ratio, and the engine speed, which are factors affecting the supply error rate, are respectively multiplied by a predetermined function to obtain the correction amount for each factor. The correction amount for each is added. That is, the lubricating oil temperature is T _O , the duty ratio is D, the engine speed is N _E , and the function is F.
Assuming ₁ , F ₂ , and F ₃ , the correction amount ΔT _O = T _O × F ₁ + D ×
It is represented by F ₂ + N _E × F ₃ .

Further, the function F ₁ for calculating the correction amount,
F ₂ and F ₃ are functions as shown in FIG. Function F ₁ is shown in solid lines in FIG. 4, until the lubricating oil temperature T _O reaches the preset temperature A is a function, such as the correction amount gradually decreases in accordance with the lubricating oil temperature T _O is increased.
The function F ₂ is shown by the broken line in FIG. 4, and the duty ratio is about 50.
It is a function such that the correction amount gradually decreases after reaching%. The function F ₃ is shown by the alternate long and short dash line in FIG. 4, and the correction amount gradually increases as the engine speed increases.

That is, when the lubricating oil temperature detected by the lubricating oil temperature sensor is lower than the set temperature A, according to the correction duty ratio which is larger than the duty ratio corresponding to the engine operating state at that time by the correction amount. Three-way solenoid valve 4
Will be duty controlled. At that time, the supply amount of lubricating oil supplied to the engine becomes larger than the operation state adaptation amount.

Next, the operation of the lubricating oil supply system 1 for a two-cycle engine according to the present invention will be described with reference to FIG. When the main switch 8 is turned on, first, the control unit 7 is initialized. Then, after the engine is started, in step P ₁ , the rotation speed calculation means 11 of the control unit 7
And the throttle opening calculation means 12 determines the engine speed N _E ,
The throttle opening is calculated, and the engine rotation signal and the throttle opening signal are output to the microcomputer 14, respectively.

In the microcomputer 14, step P
_{At 2} the duty ratio D corresponding to the engine speed and throttle opening is read from the map, and at step P ₃ the lubricating oil temperature T _O at that time is recorded from the lubricating oil temperature signal from the lubricating oil temperature detecting means 13.

After that, the microcomputer 14 determines in step P ₄ whether or not the lubricating oil temperature T _O is equal to or higher than a predetermined temperature A. When the lubricating oil temperature T _O is equal to or higher than the temperature A, the routine proceeds to step P ₅ , where the duty ratio when the duty of the three-way solenoid valve 4 is controlled is the above-mentioned step P 5.
_With the duty ratio D read in step ₂ , the solenoid of the three-way solenoid valve 4 is energized in step P ₆ . That is, at this time, the three-way solenoid valve 4 is duty-controlled at the duty ratio according to the map, and the lubricating oil is supplied to the engine 2 by the operation state adaptation amount.

In step P ₄ , the lubricating oil temperature T _O
If is lower than the temperature A, the process proceeds to step P ₇ , and the supply amount correction means 15 calculates the correction amount ΔT _O of the duty ratio. This correction amount ΔT _O is calculated by comparing the lubricating oil temperature T _O detected by the lubricating oil temperature sensor 6 with the microcomputer 1
4 multiplies the duty ratio D read from the map and the engine speed N _E calculated by the engine speed calculation means 11 by functions F ₁ , F ₂ and F ₃ as shown in FIG. 4, respectively. Calculate by adding numbers.

After that, in step P ₈ , the correction amount ΔT _O is added to the above-mentioned duty ratio D to calculate the correction duty ratio, and then in step P ₆ , the solenoid of the three-way solenoid valve 4 is operated in accordance with this correction duty ratio. Energize. That is, at this time, the three-way solenoid valve 4 with the corrected duty ratio is used.
Will be duty controlled, and the amount of lubricating oil supplied to the engine 2 will be greater than the operating state adaptation amount.

After energizing the solenoid in step P ₆ , the process returns to step P ₁ and the above-described operation is repeated again to supply the lubricating oil to the engine 2.

Therefore, when the lubricating oil temperature T _O is lower than the predetermined temperature A, the lubricating oil supply amount is made larger than the engine operating condition conforming amount, so that the supplying error when the lubricating oil temperature is low and its viscosity is high. Can be kept low.

In this embodiment, the correction amount ΔT _O is calculated by the function F
_Although an example in which calculation is performed by using ₁ , F ₂ , and F ₃ is shown, a correction duty ratio map in which a correction duty ratio obtained by adding a correction amount to the duty ratio D is recorded may be used instead of the calculation. it can. In such a case, the corrected duty ratio map is read instead of performing the above-described calculation in step P ₇ of FIG. Using the corrected duty ratio map like this,
Until the lubricating oil temperature T _O rises from the low temperature side to reach the set temperature A, for example, if the lubricating oil temperature changes and the engine speed, the throttle opening degree, etc. are constant, the lubricating oil supply amount varies stepwise. To increase.

Further, although the lubricating oil temperature is detected by mounting the lubricating oil temperature sensor 6 on the lubricating oil pump 3 in this embodiment, a lubricating oil tank, a lubricating oil passage or the like may be used as a portion for detecting the lubricating oil temperature. Good. If the lubricating oil pump 3 is used to detect the lubricating oil temperature as in the present embodiment, even if the present invention is applied to a multi-cylinder engine and a plurality of lubricating oil supply passages are provided, the lubricating oil temperature sensor is 1 Since it is necessary to provide only one piece, the flow passage resistance can be made uniform in the lubricating oil supply passage for each cylinder.

Further, in order to detect the lubricating oil temperature, in addition to exposing the detecting portion of the temperature sensor to the lubricating oil as described above, the outside air temperature is measured and the lubricating oil temperature is functionally obtained from the temperature. You can also

Furthermore, in the embodiment, the example in which the present invention is applied to the lubricating oil supply device having the structure for controlling the duty of the three-way solenoid valve 4 is shown. However, the present invention has a structure for controlling the discharge amount of the lubricating oil pump. It goes without saying that it can also be applied to a lubricating oil supply device.

[0034]

As described above, the lubricating oil supply device for a two-cycle engine according to the present invention has a lubricating oil pump for supplying the lubricating oil to the two-cycle engine, and an amount of lubricating oil supply adapted to the operating condition of the engine. And a control device for controlling the temperature of the lubricating oil, and the control device controls the amount of lubricating oil supplied when the lubricating oil temperature for detecting the viscosity of the lubricating oil is lower than a predetermined temperature. Since the lubricating oil supply amount correcting means for increasing the amount of lubricating oil is provided, when the lubricating oil temperature is lower than a predetermined temperature, the amount of lubricating oil supplied to the engine is increased more than the operation state conforming amount.

Therefore, when the lubricating oil has a low temperature and a high viscosity, it is possible to suppress the supply error and improve the lubricating oil supply accuracy, so that the lubricating oil can be supplied in an amount corresponding to the operating state of the engine. ..

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a lubricating oil supply device for a two-cycle engine according to the present invention.

FIG. 2 is a block diagram of a control device used in a lubricating oil supply device for a two-cycle engine according to the present invention.

FIG. 3 is a flowchart showing the operation of the lubricating oil supply system for a two-cycle engine according to the present invention.

FIG. 4 is a graph showing a relationship among a correction amount, a lubricating oil temperature, a duty ratio, and an engine speed.

FIG. 5 is a diagram for explaining a problem of a conventional lubricating oil supply device.

FIG. 6 is a graph showing the relationship between lubricating oil temperature, duty ratio, engine speed and supply error rate.

[Explanation of symbols]

 1 Lubricating Oil Supply Device 2 Engine 3 Lubricating Oil Pump 4 Three-way Solenoid Valve 5 Lubricating Oil Tank 6 Lubricating Oil Temperature Sensor 7 Control Unit 14 Microcomputer 15 Supply Amount Correcting Means

Claims (1)

[Claims] 1. A lubrication oil pump for supplying lubrication oil to a two-cycle engine, and a control device for controlling the lubrication oil supply amount to an amount suitable for engine operating conditions. A two-cycle engine provided with a lubricating oil supply amount correction means for increasing the lubricating oil supply amount by a predetermined amount from the operating state adaptation amount when the lubricating oil temperature for detection is lower than a predetermined temperature. Lubricating oil supply device.