JPH10227219A - Exhaust port opening and closing valve operation device of 2 cycle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control an exhaust port opening and closing valve by indirectly detecting the opening of a piston type throttle valve of a 2 cycle engine. SOLUTION: An oil pump for cylinder lubrication 24 and a rotating type throttle sensor 23 are installed on a cover integral with an engine, and an adjusting shaft 24a and the shaft 23a for a throttle sensor 23 are connected at a connecting part 26 so as to adjust the oil delivery amount of the oil pump 24, and a lever 28 fixed to the adjusting lever 24a is connected to an accelerator grip 22 by a wire 29a. Also a piston type throttle valve is connected to the accelerator grip 22 by a wire 21a. When the accelerator grip 22 is rotated, the shaft 23a for the throttle sensor 23 is rotated according to the opening of the throttle valve and, when the opening is reduced to a low engine speed, an exhaust port opening and closing valve is closed according to the amount of rotation of the shaft 23a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for operating an exhaust port opening / closing valve provided for restricting the outlet side of an exhaust port during a low-speed operation of a two-cycle engine.

[0002]

2. Description of the Related Art A two-stroke engine in which the opening of a piston type carburetor is detected to control an exhaust port opening / closing valve is disclosed in Japanese Patent Application Laid-Open No. 7-71279.

[0003] However, a piston type carburetor generally does not have a rotating shaft unlike a butterfly type carburetor.
The opening degree of the carburetor cannot be directly taken out as a rotation angle, so that the opening degree is taken out as a linear motion, and ECU,
This is converted into a rotary motion via a servomotor or the like to rotate the exhaust port opening / closing valve, and the configuration is extremely complicated.

As means for avoiding such a complicated structure, conventionally, means for converting the linear motion of a piston type carburetor into a rotary motion by a link mechanism and transmitting the same to a rotary type opening sensor has been adopted. Although the configuration of the means is simpler than that of the known technique, the number of parts is increased due to the provision of the link mechanism, and the structure of the vaporizer is changed to connect the link mechanism to the vaporizer. There is a disadvantage that it becomes necessary to do so and the cost becomes high.

[0005]

An object of the present invention is to provide an oil pump in which an oil discharge amount changes in response to an accelerator operation,
In a two-cycle engine including an exhaust port opening / closing valve that opens and closes an exhaust port of the engine according to at least the number of revolutions of the engine, the exhaust port interlocks with the accelerator operation without increasing the number of parts or changing the structure of the carburetor. It is an object to control an on-off valve.

[0006]

According to a first aspect of the present invention, there is provided an oil control apparatus that varies an oil discharge amount in response to an occupant's accelerator operation. In a two-stroke engine including a pump and an exhaust port opening / closing valve that opens and closes an exhaust port of the engine according to at least the number of revolutions of the engine, the variable displacement mechanism of the oil pump is constituted by a rotating shaft that is linked to accelerator operation. In addition, a throttle sensor is integrally provided on the rotating shaft to detect an accelerator opening, and a signal thereof is used as a control factor of the exhaust port opening / closing valve.

[0007] According to this means, the rotation of the rotary shaft of the variable displacement mechanism of the oil pump can be regarded as the same as the operation of the accelerator, so that the existing inexpensive throttle sensor can be used without providing a special rotary shaft. it can.

Further, the second means is, as described in claim 2, in claim 1, wherein the throttle sensor is a potentiometer. According to this means, a fine control signal can be detected.

According to a third aspect, in the first aspect, the throttle sensor is turned on.
-It is a switching sensor for OFF. According to this means, the throttle sensor is configured simply and inexpensively.

According to a fourth aspect, as set forth in the fourth aspect, in the second or third aspect, the exhaust port opening / closing valve is driven by a servomotor. According to this means, the exhaust port opening / closing valve is reliably driven.

According to a fifth aspect of the present invention, as set forth in the fifth aspect, in the fourth aspect, the exhaust port opening / closing valve is driven by a solenoid valve. According to this means, the driving means of the exhaust port on-off valve is simple and inexpensive.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, 1 is a two-stroke engine embodying the present invention, 2 is a cylinder, 2a is a cylinder bore, 3 is a cylinder head having an ignition plug 4, 5 is a crankcase, 6 is a piston, and 7 is a crankshaft. It is.

As shown in FIG. 2, an intake pipe 5b is connected to the crankcase 5 via a reed valve 5a, and a resonance chamber 5d for suppressing intake pulsation is connected to the intake pipe 5b via a pipe 5c. A throttle sensor 23 described later is provided on the side of the intake pipe 5b.

A scavenging port 8 and an exhaust port 9 are provided in the cylinder block 2. An exhaust port opening / closing valve 10 having a valve shaft 10 a shown in FIG. 3 is rotatably supported downstream of the exhaust port 9. I have. A pulley-type lever 11 is fixed to the valve shaft 10a.
Are connected, and the other end of the wire 12a is
It is connected to a pulley-type lever 14 on the output side of the servomotor 13, and when the engine is running at a low speed, the exhaust port opening / closing valve 10 is turned to the closed position via the servomotor 13, and exhaust gas including fresh air blows through. To prevent combustion in the exhaust port 9.

A piston-type carburetor 15 is connected to the intake pipe 5b. The carburetor 15 is a well-known carburetor 15 and has a piston-type throttle valve 17 for narrowing an intake passage 16 as shown in FIG. It has a float chamber 18, a main jet 19, and a jet needle 20 integrated with a throttle valve 17. The throttle valve 17 is
2 is connected to the wire 21a of the cable 21 extending from
The return spring 17a is pressurized downward and moves up and down by rotating the accelerator grip 22 to adjust the output of the engine.

In FIGS. 2 and 5, reference numeral 23 denotes a rotary throttle sensor having a shaft 23a.
Instead of being directly connected to the throttle valve 17, it is connected to an oil pump 24 for lubricating the cylinder. 25 in the figure
Is a cover of the oil pump 24, and the cover 25
The oil pump 24 is supported and attached to the outer shell of the engine. The oil pump 24 has an adjusting shaft 24a for adjusting the amount of oil discharged, and the shaft 24a and the shaft 23a of the throttle sensor are engaged by a connecting portion 26 formed by engaging the unevenness formed on the end surfaces of both shafts. , Throttle sensor 23
Is screwed to the cover 25 with screws 27 so that the throttle sensor 23
5, and the connecting portion 26 is integrated while maintaining the meshing state.

An opening / closing lever 28 is fixed to an adjusting shaft 24a of the oil pump 24, and is pressed to a small flow rate side by a return spring 28a. The opening / closing lever 28 is connected to the accelerator grip 22 by a wire 29a of a cable 29. It is connected. Since the throttle valve 17 is connected to the accelerator grip 22 by the wire 21a, when the accelerator grip 22 is rotated, the throttle valve 17 is operated and the oil pump 24 is operated.
And the shaft 23a of the throttle sensor 23 rotate integrally.

Accordingly, the air-fuel mixture corresponding to the opening of the throttle valve 17 is supplied to the engine, and the adjusting shaft 24a is rotated according to the opening, so that the amount of oil corresponding to the rotation angle is supplied to the engine. Released during. Further, the adjusting shaft 24
Since the throttle sensor 23 is connected to the motor a, the throttle sensor 23 also rotates by the same angle, and transmits a signal proportional to the rotation angle to the servo motor 13 to operate the exhaust port opening / closing valve 10 so that the throttle sensor 23 is operated. When the valve 17 reaches a predetermined low-speed position, the exhaust port opening / closing valve 10 is turned to the closed position to prevent blow-by of fresh air.

Next, the embodiment shown in FIGS. 6 and 7 will be described. FIG. 6 shows the engine 1 and the intake pipe 5
b, the carburetor 15 and the like are the same as those shown in FIGS. 1 to 4, but differ in that a cam mechanism 30 is used instead of the throttle sensor 23.

FIG. 7 is an enlarged view of the cam mechanism 30. The shaft 31 is an adjusting shaft of the oil pump 24.
The end is formed in a semicircular shape unlike the eccentric cam 3
2, a support shaft 34, a pin 35, and a potentiometer 36 are mounted on a support plate 33 integral with the shell of the engine, and a leg of a substantially T-shaped driven lever 37 is pivotally mounted on the support shaft 34. The driven lever 37 includes an arm 37a in contact with the eccentric cam 32 and a pushing rod 36a of the potentiometer 36.
The arm 37a is pressed by a coil spring 37c in a direction in which the arm 37a is pressed against the eccentric cam 32.

When the accelerator grip 22 is turned, the adjusting shaft 31 and the eccentric cam 32 turn counterclockwise as indicated by an arrow to turn the driven lever 37 counterclockwise and push the lever 37 by the arm 37b. The potentiometer 36 is operated by pushing the rod 36a, and the potentiometer 36 operates the servo motor 13 to adjust the exhaust port opening / closing valve 10 so that the exhaust port is closed when the engine reaches a predetermined low speed.

[0022]

As is apparent from the above description, according to the first means, if the existing inexpensive throttle sensor is directly connected to the rotary shaft of the variable discharge rate adjusting mechanism of the oil pump, the exhaust port can be opened and closed. Since the valve can be controlled, there is an advantage that the structure can be simplified and the structure can be reduced.

Further, according to the second means, since the position of the potentiometer is accurately detected, a fine control signal can be transmitted.

According to the third means, since the throttle sensor is a switching sensor for ON / OFF, there is an advantage that the throttle sensor can be configured simply and inexpensively.

According to the fourth means, since the exhaust port opening / closing valve is driven by the servomotor, there is an advantage that the exhaust port opening / closing valve is driven reliably.

According to the fifth means, since the exhaust port opening / closing valve is driven by the solenoid valve, there is an advantage that the driving means is simple and inexpensive.

[Brief description of the drawings]

FIG. 1 is a front view of an engine embodying the present invention.

FIG. 2 is a partial sectional view of the same.

FIG. 3 is a cross-sectional view of the same exhaust port.

FIG. 4 is a sectional view of the vaporizer.

FIG. 5 is a side view of the main part of the above.

FIG. 6 is a front view of another embodiment.

FIG. 7 is a front view of a main part of the above.

[Explanation of symbols]

1 2 cycle engine 9 exhaust port 10 exhaust port opening / closing valve 15 carburetor 17 throttle valve 22 accelerator grip 23 throttle sensor 24 oil pump 26 connecting part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 13/02 F02D 13/02 A J F02M 9/06 F02M 9/06 A

Claims (5)

[Claims] 1. A two-stroke engine comprising: an oil pump that varies an amount of oil discharged in response to an accelerator operation by a passenger; and an exhaust port opening / closing valve that opens and closes an exhaust port of the engine according to at least the engine speed. ,
The discharge amount variable adjustment mechanism of the oil pump is configured with a rotating shaft linked to accelerator operation, and a throttle sensor is integrally provided on the rotating shaft to detect an accelerator opening,
An exhaust port on / off valve operating device for a two-stroke engine, wherein the signal is used as a control factor for the exhaust port on / off valve. 2. The exhaust port opening / closing valve operating device for a two-stroke engine according to claim 1, wherein the throttle sensor is a potentiometer. 3. The exhaust port opening / closing valve operating device for a two-cycle engine according to claim 1, wherein the throttle sensor is a switching sensor for ON / OFF. 4. The device for operating an exhaust port on / off valve of a two-cycle engine according to claim 2, wherein the exhaust port on / off valve is driven by a servomotor. 5. The exhaust port opening / closing valve operating device for a two-cycle engine according to claim 4, wherein the exhaust port opening / closing valve is driven by a solenoid valve.