JP3114080B2 - Separate refueling system for two-stroke engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separation and refueling system for a two-stroke engine, and more particularly to a separation and refueling system for performing optimum refueling in accordance with the operating state of the engine.

[0002]

2. Description of the Related Art Generally, in a small two-stroke engine used for a motorcycle or a general-purpose machine, the lubrication of the engine is
This is a separated oil supply system in which lubricating oil is sprayed and mixed into a fuel mixture in an intake passage by an oil supply pump and lubricated. The power of the oil supply pump is input from the crankshaft of the engine, and the minimum lubricating oil required for the load of the engine is supplied according to the throttle opening.

However, the amount of lubricating oil required by the engine does not necessarily have to depend only on the load on the engine. For example, when the engine speed is high even when the load on the engine is small, the amount of lubricating oil may be increased. Otherwise, the lubrication conditions will deteriorate. Therefore, conventionally, in consideration of such a case, fine adjustment is performed based on experience in addition to the setting depending on the throttle opening. That is, since the supply amount of the lubricating oil is increased in anticipation of the safety factor, the lubricating oil amount has been consumed more than originally required.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a two-stroke separate lubrication system for an engine capable of accurately supplying an optimum amount of lubricating oil required by an engine with a simple configuration utilizing electronic control. Is to provide.

[0005]

According to a second aspect of the present invention, there is provided a separate oiling apparatus for a two-stroke engine, in which a pump plunger is provided with a drive plunger which reciprocates in conjunction with engine rotation, and a stroke amount of the drive plunger. Regulating means for controlling the position of the regulating means, a detecting means for detecting a stroke limit time of the drive plunger limited by the regulating means, and an electronic control unit, respectively. By the electronic control unit, the execution stroke amount of the drive plunger calculated from the stroke limit time of the drive plunger detected by the detection means and the engine rotation speed is calculated from a map in which an optimal stroke amount is set in advance according to the operating state of the engine. The position adjusting means is controlled so as to be equal to the selected target stroke amount.

[0006] The execution stroke amount of the drive plunger calculated from the stroke limit time of the drive plunger and the engine rotation speed as described above is changed to a target stroke amount selected from a map in which an optimum stroke amount is set in advance according to the operation state of the engine. , It is possible to accurately supply the optimum amount of lubricating oil required by the engine.

[0007]

FIG. 1 shows a two-stroke engine 10 comprising two cylinders for a motorcycle provided with a separate oiling device according to an embodiment of the present invention (only one cylinder is shown in the drawing). A piston 13 is slidably fitted to a cylinder 11 of the engine 10, and an intake passage 14 and an exhaust passage 15 are connected. Further, the crankcase 12 supports a crankshaft 16 driven by a piston 13.

The intake passage 14 is provided with a carburetor 17 having a piston type throttle valve 21. The throttle valve 21 is biased by a coil spring 22 in a direction to close the intake passage 14, and is connected to a handle grip 24 via an operation wire 23. An opening sensor 74 (described later) for the throttle valve 21 is provided in the middle of the operation wire 23.

The lubricating oil supply pump 33 includes a crankshaft 1
6 is driven by a drive shaft 38 directly connected to the drive shaft 6. The oil supply pump 33 measures the lubricating oil supplied from the tank 31 through the oil pipe 32 to a predetermined amount according to the operation state of the engine, and pressure-feeds the lubricating oil from the oil supply pipe 36 to an oil supply port 37 downstream of the throttle valve 21. I do. FIG. 2 shows details of the refueling pump 33, and a pump cylinder 51 thereof is
It is supported rotatably around the cylinder axis. A drive plunger 56 and a rod-shaped regulating means 55 are inserted into the bore of the pump cylinder 51 so as to face each other.
A pump chamber 57 is formed between the drive plunger 56 and the regulating means 55. A gear 52 is fixed to the lower end of the pump cylinder 51, and is driven to rotate via a worm 39 meshed with the gear 52. The worm 39 is fixed to a drive shaft 38, and the drive shaft 38 is directly connected to the crankshaft 16 to be driven.

On the lower surface of the gear 52, a drive cam 46 in which peaks and valleys are alternately formed is provided along the circumferential direction. The drive cam 46 is engaged with a driven pin 47 fixed to be orthogonal to the drive plunger 56. The driven pin 47 reciprocates in the axial direction along a guide groove 48 provided in the lid 44 by following the valley and valley of the driving cam 46, and reciprocates the driving plunger 56 integrated therewith.

The driving plunger 56 is urged upward by a coil spring 53, and the regulating means 55 is
It is pressed against the upper reciprocating cam 54 by 3a. The pump chamber 57 is provided with oil passage holes 58 radially as shown in FIG.
When the pump plunger 56 rotates together with the lubricating oil, the oil passage hole 58 is alternately communicated with the lubricating oil suction passage 61 and the discharge passage 62. The hole 58 communicates with the suction passage 61 to suck the lubricating oil into the pump chamber 57, and when communicating with the discharge passage 62 when the volume of the pump chamber 57 is reduced, the oil is discharged. In this embodiment, since the engine is a two-cylinder engine, two discharge passages 62 are provided to supply the two cylinders.

The regulating means 55 includes a reciprocating cam 54 having a truncated cone shape.
The position in the stroke direction is regulated by the contact position
The stroke of the drive plunger 56 is limited. That is, the reciprocating cam 54 serves as a position adjusting means for adjusting the position of the regulating means 55 in the pump cylinder. As the position of the regulating means 55 moves downward, the stroke of the drive plunger 56 is shortened to reduce the amount of lubricating oil discharged, and as it moves upward, the stroke is increased to increase the amount of lubricating oil discharged. It is supposed to.

The reciprocating cam 54 as a position adjusting means is integrated with an armature 66 slidably supported on a support shaft 65. The armature 66 is urged leftward in the figure by a spring 67, and is attracted by the magnetic pole 68 when the electromagnetic coil 41 is energized, and moves rightward against the spring 67. The electromagnetic coil 41 is excited by the current controlled by the inverter, and stops the armature 66 at an arbitrary position on the support shaft 65 by the balance with the elastic force of the spring 67. Further, when there is a failure in the excitation system of the electromagnetic coil 41, the reciprocating cam 54 is corrected by the spring 67 to the lubricating oil increasing side in a fail-safe manner.

The outer periphery of the regulating means 55 and the pump cylinder 51
Are electrically insulated by being covered with insulating materials 81 and 82, respectively. The lower end of the regulating means 55 and the upper end of the driving plunger 56 form an electric switch 59, and the above-described stroke limiting of the driving plunger 56 is performed. It functions as time detecting means. That is, the electric switch 5
Reference numeral 9 designates a configuration in which the drive plunger 56 is configured as a ground electrode and the regulating means 55 is defined as a potential electrode. . The potential electrode regulating means 55 is connected to an input terminal of an electronic control unit 70 described later via a lead wire 60a.

FIG. 4 shows an electronic control unit 70 for controlling the electromagnetic coil 41 of the position adjusting means, and controls each signal as shown in the flowchart of FIG. 5 and the operation time chart of FIG.
The electronic control unit 70 comprises a microprocessor 71 and an inverter 72, the input terminal of which is the throttle valve 21.
Sensor 74 for detecting the opening of the engine, and a primary circuit 75 of an ignition circuit functioning as an engine speed sensor
And a lead wire 60a of an electric switch 59 (detection means) for detecting a stroke limit time of the drive plunger, and an output terminal is connected to the electromagnetic coil 41.

The microprocessor 71 incorporates, in its memory section, a three-dimensional map of the optimal lubricating oil supply amount prepared in advance in accordance with the opening signal of the throttle valve 21 and the engine speed signal as data. I have. Further, the inverter 72 outputs an output subjected to pulse width modulation control (PWM control) to the electromagnetic coil 41. That is, the time axis is divided into minute times T, the pulse width in each section is controlled to control the entire voltage to a desired value, and the actual stroke time (execution stroke amount B) of the drive plunger 56 and the tertiary A PI control unit 77 that compares the optimum stroke time (target stroke amount A) read from the original map, and a PWM control unit 78 that adjusts the width of the pulse voltage applied to the electromagnetic coil 41 to a large or small value.
And

Referring to the flowchart of FIG. 5 and the operation time chart of FIG. 6, the microprocessor 71 performs the above-described operation based on the reading of the engine speed N (100) and the reading of the opening θ of the throttle valve 21 (101). The optimal lubricating oil supply amount is read from the three-dimensional map (102). Then, the pulse amount (target stroke amount A) corresponding to the optimal lubricating oil amount read from the three-dimensional map is read.

On the other hand, the stroke limit time t ₁ during which the drive plunger 56 is in contact with the regulating means 55 is measured as a pump pulse from the electric switch 59 (detecting means) (10).
3) Further, the engine speed N is input, and the conversion circuit 79 calculates the execution amount B (104). The calculation of the execution amount B is based on the fact that the rotational speed of the drive cam 46 is reduced from the rotational speed N of the engine.
Is calculated as the stroke limit time for the rotation cycle of. Next, the execution stroke amount B is compared with the target stroke amount A in the PI control unit 77, and the difference C is calculated (10).
5).

In the comparison between the execution stroke B and the target stroke A in the PI control unit 77, when the execution stroke B is smaller than the target stroke A, the PW corresponding to the difference C is determined.
The pulse width is reduced by the M control unit 78. Conversely, when the execution amount is larger, the pulse width is increased, and when they are the same, the pulse width is left as it is. Output D from PWM control unit 78
During stroke time limit t ₁ for calculating the actual stroke amount B of the driving plunger (while electrical switch 59 is in the ON state), it is necessary to not performed. Due to such regulation, the stroke position of the drive plunger can be correctly detected. The PWM from the PWM control unit 78
When the electromagnetic coil 41 is excited by the M output, the armature 66 moves together with the reciprocating cam 54 to a position that balances the resilience of the spring 67, and sets the stroke of the drive plunger 56 to the target stroke A.

In the present invention, an electric switch is formed between the regulating means and the driving plunger as means for detecting the stroke regulation time of the driving plunger. A proximity switch may be provided on one of the drive plunger and the drive plunger to form a contactless switch. Further, it is not always necessary to form the electric switch as the detecting means between the regulating means and the driving plunger, and the same effect can be obtained even if it is formed between the driving cam 46 and the driven pin 47. it can.

[0021]

As described above, according to the present invention, a pump cylinder is provided with a drive plunger which reciprocates in conjunction with the rotation of the engine, a restricting means for restricting a stroke amount of the drive plunger, and a position of the restricting means. , A detecting means for detecting a stroke limit time of the drive pump limited by the regulating means, and an electronic control unit, wherein the electronic control unit detects the stroke detected by the detecting means. The position adjusting means so that an execution stroke amount of the drive plunger calculated from the time limit and the engine rotation speed is made equal to a target stroke amount selected from a map in which an optimum stroke amount is set in advance according to an operation state of the engine. The simple configuration using electronic control enables accurate determination of the optimal amount of lubricating oil required by the engine. It can be supplied.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a cross section of a two-stroke engine provided with a separation refueling device of the present invention in a partial cross section.

FIG. 2 is a longitudinal sectional view of a refueling pump used in the separation refueling device of the present invention.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a control circuit diagram of the separation oil supply device of the present invention.

FIG. 5 is a flowchart based on the control circuit diagram of FIG. 4;

FIG. 6 is an operation time chart based on the control circuit diagram of FIG. 4;

[Explanation of symbols]

Reference Signs List 10 2 stroke engine 33 refueling pump 38 drive shaft 41 electromagnetic coil 66 armature 54 reciprocating cam (position adjusting means) 52 gear 46 drive cam 51 pump cylinder 55 regulating means 56 drive plunger 70 electronic control unit 57 switch (detection of stroke limit time) means)

Claims (2)

(57) [Claims] A pump cylinder provided with a drive plunger which reciprocates in conjunction with engine rotation, a restricting means for restricting a stroke amount of the drive plunger, a position adjusting means for controlling a position of the restricting means, Detecting means for detecting the stroke limit time of the drive plunger limited by the regulating means, and an electronic control unit are respectively provided, and the electronic control unit calculates the stroke limit time and the engine rotation speed detected by the detecting means. A separate stroke refueling system for a two-stroke engine that controls the position adjusting means so that the execution stroke amount of the drive plunger is made equal to a target stroke amount selected from a map in which an optimum stroke amount is set in advance according to the operating state of the engine. apparatus. 2. A separate refueling apparatus for a two-stroke engine according to claim 1, wherein said position adjusting means is not operated while said detecting means detects a stroke limit time of said drive plunger.