JPH10196409A - Throttle valve controller of spark ignition type two-cycle internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decelerate an internal combustion engine abruptly as required and keep an idle operation condition stably by providing a throttle adjusting means with a control means which outputs a control signal in accordance with operation situation. SOLUTION: A throttle adjusting mechanism 35 is provided between a link arm and a throttle drum 17 which are integral with a throttle shaft. It is possible to drive a throttle valve by a predetermined amount in the direction of closing for an operation position of a throttle valve operation means in a certain operation region due to the operation of an escape drive mechanism of the throttle adjusting mechanism 35 and drive the throttle valve by a predetermined amount in the direction of opening for an operation position of the throttle valve operation means in the other operation region which is different from the certain operation region. Consequently, it is possible to operate and control the internal combustion engine properly in accordance with operation conditions of the internal combustion engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve operating means for a spark-ignition type two-stroke internal combustion engine capable of self-igniting fresh air in a combustion chamber at least in a low load operation region to perform active hot atmosphere combustion. The present invention relates to a throttle valve control device capable of opening and closing a throttle valve opening freely in accordance with an operating condition without operating the throttle valve.Specifically, when it is necessary to rapidly decelerate the internal combustion engine, The present invention relates to a throttle valve control device capable of decelerating and stably maintaining an idling operation state.

[0002]

2. Description of the Related Art In a spark ignition type two-cycle internal combustion engine, an exhaust port and a scavenging port opened and closed by a piston are formed on the inner peripheral surface of a cylinder hole, and fresh air pre-pressurized in a crank chamber is transferred from the scavenging port into the cylinder chamber. At the same time, the burned gas in the cylinder chamber is exhausted from an exhaust port, and fresh air compressed in the cylinder chamber is ignited by an ignition plug.

In such a conventional spark ignition type two-stroke internal combustion engine, when the exhaust port is enlarged to set the output and efficiency in a high-speed, high-load operation range to a high level or more, the fresh air in a low-load operation range is increased. As a result, the amount of unburned hydrocarbons in the exhaust gas increased, and fuel efficiency deteriorated.

In order to solve this problem, the exhaust control valve, which is an exhaust passage opening ratio adjusting means, is driven to an exhaust passage opening ratio corresponding to the internal combustion engine speed and the throttle valve opening, so that at least in a low load operation region. Appropriately controlling the pressure in the cylinder at the time of closing the exhaust opening by the piston, activating fresh air in the combustion chamber by the heat energy of the burned gas remaining in the combustion chamber, The present applicant has filed an application (Japanese Patent Laid-Open No. 7-71279) by developing an internal combustion engine capable of causing self-ignition of fresh air.

[0005] Combustion in which active hot atmosphere combustion is performed by positively controlling the ignition timing preferable for the operation of the internal combustion engine as described above is hereinafter referred to as AR combustion.

[0006] In a spark ignition type two-cycle internal combustion engine capable of performing AR combustion by restricting an exhaust control valve, FIG.
As shown in FIG. 3, in the low load operation region where the throttle valve opening _θth is small, the heat energy contained in the burned gas in the previous cycle is sufficiently and effectively used to activate fresh air in the combustion chamber. Since the internal combustion engine can be operated in a combustion state close to complete combustion, when the throttle valve is throttled, the internal combustion engine has higher output characteristics than in a normal combustion state involving irregular combustion. Therefore, when this internal combustion engine is mounted on a vehicle or the like,
When a vehicle or internal combustion engine is suddenly decelerated for some reason in a high-speed, high-load operation state, even if the throttle valve is throttled, the opening degree of the throttle valve is not a normal internal combustion engine that does not perform AR combustion. When the opening degree of the idling valve is close to a certain degree (which is somewhat larger than the fully closed state), the internal combustion engine cannot be rapidly decelerated due to its high output characteristics.

The minimum throttle valve opening is smaller than the idling valve opening of a normal internal combustion engine that does not perform AR combustion.
If the throttle valve is set close to fully closed, the throttle valve will be throttled to the minimum throttle valve opening, and the exhaust valve will be opened to allow the internal combustion engine to run idling in a normal combustion state. Can not maintain the idling operation state
The internal combustion engine may stop.

[0008]

To overcome such difficulties, the present applicant filed a patent application on November 27, 1993 (Japanese Patent Application No. 5-321037 (Japanese Patent Application Laid-Open No. 7-150981)). However, in the present invention, the throttle grip, which is a throttle valve operating member, is connected to the throttle drum via a wire, the arm is integrally connected to the throttle drum, and the throttle valve is connected via a link to the actuator. The tip of the arm is in contact with the cam controlled by the above, and when the internal combustion engine is to be rapidly decelerated in a high-speed / high-load operation state, the tip of the arm is located on the cam mountain of the cam. When the cam is rotated so that it does not come into contact with the engine, and when the internal combustion engine is to be operated by idling operation, the tip of the arm is brought into contact with the cam hill to adjust the throttle valve opening to idle. It has limited so as not to be opening below.

However, since the throttle drum integrated with the arm is connected to the throttle grip via a wire, the throttle grip twist angle at which no force is applied to the throttle grip during rapid deceleration operation, and the throttle angle during idle operation, Unlike the twist angle of the throttle grip that does not apply any force to the grip, there is a sense of incompatibility.

Further, since the throttle drum is always urged by a spring in the throttle valve closing direction, the difference between the twist angle of the throttle grip during the rapid deceleration operation and the twist angle of the throttle grip during the idle operation causes There was a difference in the operation reaction force of the throttle grip during both operations, and when the throttle grip was operated based on this operation reaction force, the throttle operation could not be properly performed in both operation states.

[0011]

SUMMARY OF THE INVENTION The present invention relates to an improvement in a throttle valve control device for a spark ignition type two-stroke internal combustion engine which solves such a problem. In a spark-ignition two-cycle internal combustion engine in which the opening ratio of the exhaust passage is adjusted by the rate adjusting means to control the compression start cylinder pressure and fresh air in the combustion chamber is self-ignited at least in a low load operation region,
A throttle valve, a throttle valve operating means for opening and closing the throttle valve by manual operation, and a throttle valve and a throttle valve operating means interposed therebetween, which will be described later without affecting the operation amount or operating force of the throttle valve operating means. A throttle adjusting means for driving the throttle valve in a closing direction or an opening direction by a predetermined amount in response to a control signal of a control means; and in a certain operation region, the throttle valve is driven in a closing direction, and In another operation region different from the region, a control unit that outputs a control signal to the throttle adjustment unit so as to drive the throttle valve in the opening direction is provided.

Since the present invention is constructed as described above, it does not affect the operation amount or the operation force of the throttle valve operating means in any operation range and allows the operating position of the throttle valve operating means to be changed. On the other hand, the throttle valve can be driven in the closing direction by the predetermined amount, and the throttle valve is driven in the opening direction by the predetermined amount with respect to the operation position of the throttle valve operating means in another operation region different from the certain operation region. Thus, the operation of the internal combustion engine can be appropriately controlled in accordance with the operation state of the internal combustion engine without causing a feeling of strangeness in the operation of the throttle valve.

According to a second aspect of the present invention, when the throttle valve operating means is fixed, the throttle valve is further opened or closed by the operation of the relief driving mechanism. Can be done,
With the non-operation of the relief drive mechanism, the throttle valve can be automatically returned to the original opening, and the operation of the internal combustion engine can be easily controlled according to the operation state of the internal combustion engine. it can.

Further, by constructing the present invention as described in claim 3, the relief driving mechanism can be configured to have a simple structure, and the structure of the throttle valve adjusting means and thus the throttle valve control device can be simplified. The weight and cost of the throttle valve control device can be reduced.

Further, according to the present invention, in the high-speed engine rotation region, the throttle valve can be throttled to rapidly decelerate the internal combustion engine.

Further, according to the present invention, the internal combustion engine can be rapidly decelerated in the high-speed engine rotation region exceeding the idling rotation region, and the stable idling can be performed in the idling rotation region. Driving can be performed.

According to the present invention, the output member can be more reliably driven with a simple structure.

Further, by configuring the present invention as described in claim 7, the vehicle equipped with the internal combustion engine can be easily stopped or decelerated by applying an engine brake to the vehicle.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention shown in FIGS. 1 to 9 will be described below. The spark-ignition two-cycle internal combustion engine 1 equipped with the combustion control device of the present invention is mounted on a motorcycle (not shown). In the spark-ignition two-cycle internal combustion engine 1, a cylinder block is provided above a crankcase 2. The cylinder head 3 and the cylinder head 4 are sequentially stacked and integrally connected to each other.

A piston 6 is vertically slidably fitted in a cylinder hole 5 formed in the cylinder block 3. The piston 6 and the crank 8 are connected to each other by a connecting rod 7. The crank 8 is driven to rotate as it moves up and down.

Further, the crank chamber 9 in the crank case 2
An intake passage 10 is connected to the intake passage 10, and a carburetor 11 and a reed valve 13 are interposed in series in the intake passage 10. As shown in FIG. 6, a throttle valve 12 of the carburetor 11 includes a rod 14 and a link. The throttle shaft 16 is connected to a throttle shaft 16 via an arm 15, and the throttle shaft 16 is connected to a throttle drum 17 via a throttle adjustment mechanism 35 described later. The throttle drum 17 is connected to a throttle grip (not shown) via a wire 18. When the throttle grip is twisted in the acceleration direction, the throttle drum 17 rotates counterclockwise, the throttle valve 12 rises, and the throttle valve opening increases.

Further, the intake passage 10 is connected to the crank chamber 9 of the crankcase 2, and a scavenging port 19 and an exhaust port 20 are opened on the inner peripheral surface of the cylinder hole 5. The exhaust port 20 communicates with an exhaust passage 22 while communicating with the crank chamber 9 through the exhaust port.

An ignition plug 24 is provided in the combustion chamber 23 above the cylinder hole 5, and fresh air mixed with fuel supplied from the carburetor 11 becomes a negative pressure in the crank chamber 9 during the rising stroke.
When the piston 6 is lowered and the scavenging port 19 is opened, compressed fresh air is supplied from the scavenging port 19 into the combustion chamber 23, and is compressed in the descending stroke. A part of the burned gas in the combustion chamber 23 is discharged from the exhaust port 20 to the exhaust passage 22 by the entry of the compressed fresh air, and the scavenging port 19 and then the exhaust port 20
Is closed, the air-fuel mixture in the combustion chamber 23 is compressed by the rise of the piston 6, and the ignition by the spark plug 24 or the self-ignition by the heat energy of the residual gas in the previous cycle is performed near the top dead center. Has become.

Further, an exhaust control valve 25 as an exhaust passage opening ratio adjusting means for adjusting the opening area of the exhaust port 20 is formed in a substantially sector shape in a side view, and the exhaust control valve 25 is provided in the cylinder block 3 near the exhaust port 20. A substantially fan-shaped storage storage recess 26 for storing the valve 25 is formed in a side view, and the storage storage recess 26 is a lid member.
It is sealed with 27.

Further, the exhaust passage of the cylinder block 3
An exhaust passage 28 is formed in the lid member 27 so as to be smoothly connected to the downstream part of the cylinder 22, and the drive shaft 29 spline-fitted to the fan-shaped center of the exhaust control valve 25 is connected to the cylinder block 3 and the lid member 27. The driven pulley 30 shown in FIG. 2 is integrally fitted on a drive shaft 29 integrated with the exhaust control valve 25, and the driven pulley 30 is Drive pulley of exhaust control servo motor 32 via drive cable 31
The exhaust control valve 25 is oscillated up and down by the exhaust control servomotor 32, and is connected to 0 to several%.
The required exhaust opening ratio θe is set to a required exhaust opening ratio between θe and 100%. A communication hole 34 is provided at the bottom of the exhaust control valve 25.

The throttle adjusting mechanism 35 interposed between the link arm 15 integrated with the throttle shaft 16 and the throttle drum 17 is configured as shown in FIGS.

First, the throttle shaft 16 is rotatably supported via two bearings (left end and center in the figure) of bearings 37 arranged in the carburetor operating section main body 36 in the axial direction, and is shown in FIG. As shown in FIGS. 6 and 7, a sleeve 38 is fitted to a substantially central portion of the throttle shaft 16, and the base end 15 of the link arm 15 is fitted around the outer periphery of the sleeve 38.
a is fitted integrally by caulking, a bolt 39 passing through the sleeve 38 is screwed to the throttle shaft 16, and the link arm 15 is integrally connected to the throttle shaft 16.

A thrust receiving washer 40 is applied to the left end (the right end in FIG. 7) of the vaporizer operating section main body 36, and the thrust receiving washer 40 is attached to the throttle shaft 16
A sleeve 42 is rotatably fitted to the left (right side in FIG. 7) via a bearing 41, and an oil seal housing 43 and an idle control lever are fitted to the sleeve 42.
An oil seal 44 is interposed in the oil seal housing 43 between the carburetor operating portion main body 36 and the thrust receiving washer 40 in the oil seal housing 43, and oil seals 46 are provided at both ends of the throttle shaft 16. , Throttle shaft
Numeral 16 is sealed by an oil seal 46 in the carburetor operating section main body 36 and the sleeve 42.

Further, the left portion of the throttle shaft 16 (FIG. 7)
The right side of the throttle drum 17 is rotatably fitted with a throttle drum 17 via a bearing 47, a thrust receiving washer 48 is applied to the left side thereof, and a throttle lever 49 is integrally caulked to the left end of the throttle shaft 16, A lever return spring 50 is interposed between the idle control lever 45 and the throttle drum 17 at the outer periphery of the sleeve 42.

Further, stopper bosses 51a and 51b and a deceleration opening stopper 52 are provided on the left side (the right side in FIG. 7) of the throttle drum 17 so as to protrude therefrom.
To the stopper boss 51
a, the throttle lever 49 is provided with engaging pieces 53a and 53b so as to be able to engage with the stopper boss 51b, and the throttle lever 49 is further provided with an engaging piece 53c. Extends through the window 17a of the throttle drum 17 toward the idle control lever 45,
The idle control lever 45 is engaged with the projection 45a.

As shown in FIGS. 8 and 9, a deceleration opening screw 55 is inserted and screwed into a receiving piece 54 integral with the carburetor operating section main body 36.
A lock nut 56 is screwed into the receiving piece 54. One end 50a of the lever return spring 50 is engaged with the receiving piece 54, and the other end 50b of the lever return spring 50 is connected to a throttle lever.
8 and 9, the throttle lever 49 is urged in the throttle return direction, that is, clockwise, by the spring force of the lever return spring 50. The engagement piece 53b is engaged with the stopper boss 51b of the throttle drum 17, and the throttle drum 17 is also urged in the same direction. The deceleration opening stopper 52 provided on the throttle drum 17 is connected to the tip of the deceleration opening screw 55. It is designed to be locked.

Further, the idle control lever 45 extends to the rear of the vehicle (rightward in FIGS. 8 and 9), and its tip is connected to the lower end of the connecting member 60c of the idle opening setting diaphragm 60 (the swing of the idle control lever 45). The horizontal displacement of the connecting portion between the idle control lever 45 and the connecting member 60c due to the movement is absorbed by a mechanism not shown), and the lower locking piece 45b of the idle control lever 45 is used to operate the carburetor. The stop screw 59 provided on the main body 36 is engaged with a distal end of the stop screw 59.

In FIG. 4 illustrating the main part of the spark ignition type two-cycle internal combustion engine 1, a fuel tank 61 is connected to a fuel receiving chamber 11a (see FIG. 6) of the carburetor 11 via a fuel supply tube 62. The upper end of the tube 63 is connected to the carburetor 11, one end of the tube 63 is connected to a pipe 60b opening to the diaphragm chamber 60a of the idle opening degree setting diaphragm 60, and the other end of the tube 63 is connected to the idle solenoid 64. The idle solenoid is connected to the output section 64a.
One input portion 64b of 64 is connected to an air cleaner 68 via a tube 65, a joint 66 and a tube 67, and the other input portion 64c of the idle solenoid 64 is connected to one end of a tube 70 with a check valve 69 interposed. In addition, the other end of the tube 70 is connected to the intake passage 10, and when the idle solenoid 64 is not operating, the diaphragm chamber 60a of the idle opening degree setting diaphragm 60 is connected to the air cleaner.
68, the atmospheric pressure is introduced into the diaphragm chamber 60a.
A negative pressure is introduced into the diaphragm chamber 60a in communication with the diaphragm chamber 60a.

An input 71a of the slow jet control solenoid 71 is connected to an air cleaner 68 via a tube 72, a joint 66 and a tube 67, and an output 71b of the slow jet control solenoid 71 is connected to a carburetor via a tube 73. When the slow jet control solenoid 71 is not operated, the carburetor 11
No air is introduced into the slow jet portion of the carburetor 11, and no fuel is supplied into the intake passage 10 from the slow jet portion of the carburetor 11, and conversely, in the operating state, air is supplied to the slow jet portion of the carburetor 11. After being introduced, fuel is supplied into the intake passage 10 from the slow jet portion of the carburetor 11.

As further shown in FIG.
Throttle consisting of a potentiometer on the shaft 16
The opening sensor 74 is directly connected, and the throttle valve of the throttle valve 12 is opened.
Degree θ _thIs electronically controlled by the throttle opening sensor 74.
The data is input to the unit 80.

Further, two pulsars 75, 76 are disposed adjacent to the side of the crank 8 and spaced apart from each other by a predetermined angle in the circumferential direction.
And reverse rotation are detected and input to the electronic control unit 80.

In addition, a water temperature gauge 77 for detecting the temperature of the cooling water flowing in the spark ignition type two-stroke internal combustion engine 1 and a shift drum 78 of a gear transmission (not shown) are provided for neutralizing the transmission and setting the first speed. A shift position sensor 79 for detecting the second, third, fourth, fifth, and sixth speed positions is provided. Detection signals from the water temperature gauge 77 and the shift position sensor 79 are input to the electronic control unit 80. It has become.

A clutch switch 81 which is turned off when the clutch (not shown) is connected and turned on when the clutch is disconnected, a side stand switch 82 which is turned off when the side stand (not shown) is upright and turned on when the side stand is down, and a key (not shown) are inserted. Combination switch that turns on when operated
83 and a kill switch 84 attached to a handle (not shown) and turned on in a non-operation state are provided, and these are connected to the electronic control unit 80 as shown in FIG.

Next, in the electronic control unit 80, the internal combustion engine speed Ne detected by the pulsars 75 and 76 is 2500 rpm.
m, the throttle valve opening θ _th detected by the throttle opening sensor 74 is within the range of 8 to 20%, and the air passage ratio is 13 to 15, the exhaust passage opening ratio θ e becomes equal to or less than a predetermined value. like,
A control signal is transmitted to the exhaust control servomotor 32, and under this condition, the spark ignition type two-cycle internal combustion engine 1 is controlled to the AR combustion state.

As shown in FIG. 10, this AR combustion state is maintained when the internal combustion engine speed Ne is approximately in the range of 2500 rpm to 4500 rpm with the center value at 3500 rpm. ing.

When the internal combustion engine speed Ne is equal to or higher than the idle speed (1300 rpm), the combination switch 83 and the kill switch 84 are turned on and the spark ignition type two-cycle internal combustion engine 1 is operating, the combination When the switch 83 or the kill switch 84 is turned off, or when the signal from the pulsars 75 and 76 detects that the spark ignition type two-cycle internal combustion engine 1 is reversed, the gear transmission is set to a shift position other than the neutral position. In this state, when the side stand switch 82 detects that the side stand is upright, the driver returns the throttle grip to the original stop position, but there is no control signal from the electronic control unit 80 to the idle solenoid 64. When the idle solenoid 64 is in a non-operating state, the atmospheric pressure is introduced into the diaphragm chamber 60a of the idle opening degree setting diaphragm 60, The idle control lever 45 is pushed down, and the throttle lever 49 and the link arm 15 are rotated clockwise in FIGS. 8 and 9 via the protruding piece 45a and the engagement piece 53c of the idle control lever 45. The throttle valve 12 is throttled so as to be almost fully closed, so that the spark ignition type two-cycle internal combustion engine 1 is rapidly decelerated.

When the internal combustion engine speed Ne becomes less than 2000 rpm, the idle solenoid 64 is activated by the control signal from the electronic control unit 80, and the intake air in the intake passage 10 is introduced into the diaphragm chamber 60a of the idle opening degree setting diaphragm 60. When the pressure is introduced, the idle control lever 45 is pulled upward, the throttle lever 49 and the link arm 15 are rotated counterclockwise, and the throttle opening θ _th of the throttle valve 12 is slightly increased to such an extent that the idle rotation is possible. The exhaust control servo motor 32 is operated by a PWM (pulse width adjustment) control signal from the electronic control unit 80, and the exhaust control valve 25 is expanded to the normal idle exhaust passage opening ratio θe.

In the electronic control unit 80, the exhaust control valve
When 25 becomes inoperable, no current is supplied to the exhaust control servomotor 32 and the exhaust control servomotor 32
32 is to be stopped.

Further, the gear transmission is set to the neutral position,
The side stand is raised and the side stand switch
When there is no detection signal from the throttle valve 82, the throttle valve 12 is set to a throttle valve opening degree _{θth at} which the idle rotation is possible, and the exhaust control valve 25 is set to a large exhaust opening rate θe at which the idle rotation is possible. It has become so.

Further, in the electronic control unit 80, when the water temperature detected by the water temperature gauge 77 is 60 ° C. or lower, no control signal is transmitted to the slow jet control solenoid 71, and a slow air jet (not shown) is generated. Although it is in a non-operating state, when the detected water temperature of the water thermometer 77 becomes 60 ° C or more, a control signal is transmitted from the control signal to the slow jet control solenoid 71, and a slow air jet (not shown) is operated,
The required air-fuel ratio for AR combustion is controlled, so that both on-road driving and off-road driving drivability can be achieved and fuel efficiency can be improved.

Further, when the clutch (not shown) is disconnected and the clutch switch 81 is turned on, a dedicated map is selected, and the AR combustion control is not performed during the no-load operation.

Since the illustrated embodiment is configured as described above, when the spark ignition type two-stroke internal combustion engine 1 is in a stopped state, the exhaust control valve 25 operates at a relatively small exhaust passage opening ratio θe enough to allow idling. Is narrowed down to In the cranking state of the starting operation, the exhaust control valve 25 is maintained at the exhaust opening ratio θe, so that the air-fuel mixture in the combustion chamber 23 is appropriately compressed, and the intake negative pressure is introduced into the diaphragm chamber 60a. Then, the throttle valve 12 is slightly opened, so that fresh air is supplied, so that the startability is good.

After the spark ignition type two-cycle internal combustion engine 1 is started, the throttle grip is operated in the opening direction to increase the internal combustion engine speed Ne. As shown in FIG. 10, the engine enters the AR combustion region. , The exhaust passage opening ratio θe of the exhaust control valve 25 is further reduced somewhat, and AR combustion becomes possible.
The spark-ignition two-cycle internal combustion engine 1 can be operated stably and the fuel efficiency is maintained at a high level.

When the internal combustion engine speed Ne further increases,
As shown in FIG.
The exhaust passage opening ratio θe of the exhaust control valve 25 is correspondingly increased, and the spark ignition type two-stroke internal combustion engine 1 can be operated in a normal combustion state.

Further, in the high-speed operation state, the emergency spark ignition type 2 as described above is used.
When it is necessary to decelerate or stop the cycle internal combustion engine 1, as shown by the dotted line in FIG. 10, the exhaust passage opening ratio .theta.e of the exhaust control valve 25 is kept close to full open while the throttle is stopped. When the valve 12 is fully closed, the internal combustion engine speed N
When e decreases to 2000 rpm, the exhaust control servo motor 32
Operates, the exhaust control valve 25 is throttled, and the intake negative pressure is introduced into the diaphragm chamber 60a of the idle opening degree setting diaphragm 60, the throttle valve 12 is slightly opened, and the spark ignition type two-cycle internal combustion engine 1 is opened. Becomes idle operable state.

When the spark-ignition two-cycle internal combustion engine 1 is stopped, the exhaust control valve 25 is throttled to set the exhaust passage opening ratio θe to a value small enough to allow idling operation. Can be kept high.

In the state where the spark ignition type two-stroke internal combustion engine 1 is operated in the high speed range, the spark ignition type
When it is desired to rapidly decelerate or stop the cycle internal combustion engine 1, the exhaust control valve 25 is fully opened by controlling the exhaust control servomotor 32 so as to bypass the AR combustion region. 1 can easily be suddenly decelerated or suddenly stopped, and the startability can be maintained at a high level. In the case of sudden deceleration,
Idle operation can also be performed.

When the throttle drum 17 is positioned at the limit angle in the closing direction of the throttle valve 12 without applying an operating force in the acceleration direction to a throttle grip (not shown), the atmospheric pressure is applied to the diaphragm chamber 60a of the idle opening degree setting diaphragm 60. Is introduced, the throttle valve 12 is throttled to a state close to fully closed, and even when the intake negative pressure is introduced into the diaphragm chamber 60a and the throttle valve 12 is opened slightly more than fully closed, Irrespective of the minute angle turning of the valve 12 and the idle control lever 45, the operation of the diaphragm 60 is
The throttle grip (not shown) is maintained at a constant angular position without being affected by the non-operation, and the operation reaction force of the throttle grip is also equalized, so that the driver does not feel uncomfortable with the throttle operation feeling.

Further, in the idle operation state in which the intake negative pressure is introduced into the diaphragm chamber 60a so that the throttle valve 12 is slightly opened from the fully closed state, the pressure difference between the intake negative pressure in the intake passage 10 and the atmospheric negative pressure is large. Thus, the throttle valve 12 can be reliably opened.

In the embodiment shown in FIGS. 1 to 9, the lever return spring 50 is used as the elastic member of the relief driving mechanism in the throttle valve adjusting means, and the idle setting diaphragm 60 is used as the actuator. As shown in FIG. 12, a bellows telescopic tube 85 is used as an elastic member, an electromagnetic solenoid 86 is used as an actuator, and when the electromagnetic solenoid 86 is energized, the idle control lever 45 swings counterclockwise. Although the same effects as those of the embodiment shown in FIGS. 1 to 9 can be obtained, in particular, in the embodiment shown in FIGS. 11 and 12, since the electromagnetic solenoid 86 is used as the actuator, The structure is simple and the response is good.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a cylinder portion of a spark ignition type two-stroke internal combustion engine 1 provided with a combustion control device of the present invention.

FIG. 2 is a side view of a cylinder portion showing a side surface on the same side as FIG.

FIG. 3 is a cross-sectional plan view cut along the line III-III in FIG. 1;

FIG. 4 is an overall control system diagram of the embodiment shown in FIG.

FIG. 5 is an enlarged side view of the throttle valve in FIG. 1;

FIG. 6 is a vertical sectional side view of FIG. 5;

FIG. 7 is a longitudinal sectional view cut along the line VII-VII of FIG. 6;

FIG. 8 is a vertical cross-sectional side view showing a state where atmospheric pressure is introduced into a diaphragm chamber of an idle opening degree setting diaphragm.

FIG. 9 is a vertical sectional side view showing a state in which intake negative pressure is introduced into a diaphragm chamber of an idle opening degree setting diaphragm.

FIG. 10 is a characteristic diagram illustrating a relationship between an internal combustion engine speed and an exhaust passage opening ratio according to the embodiment of the present invention.

FIG. 11 is a longitudinal sectional side view similar to FIG. 8 in another embodiment of the present invention.

FIG. 12 is a vertical sectional side view similar to FIG. 9 in another embodiment of the present invention.

FIG. 13 is a characteristic diagram illustrating a change in average effective pressure between a normal combustion state and an AR combustion state when a throttle valve is changed in a spark ignition type two-cycle internal combustion engine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Spark ignition type 2 cycle internal combustion engine, 2 ... Crankcase, 3 ... Cylinder block, 4 ... Cylinder head, 5 ...
Cylinder hole, 6: piston, 7: connecting rod, 8: crank, 9: crank chamber, 10: intake passage, 11
... vaporizer, 12 ... throttle valve, 13 ... reed valve, 14 ... rod, 15
... Link arm, 16 ... Throttle shaft, 17 ... Throttle drum, 18 ... Wire, 19 ... Scavenging port, 20 ... Exhaust port, 21 ... Scavenging passage, 22 ... Exhaust passage, 23 ... Combustion chamber, 24 ...
Spark plug, 25 ... exhaust control valve, 26 ... storage recess, 27 ... lid member,
28 ... exhaust passage, 29 ... drive shaft, 30 ... driven pulley, 31 ... drive cable, 32 ... exhaust control servo motor, 33 ... drive pulley, 34 ... communication hole, 35 ... throttle adjustment mechanism, 36 ... carburetor operation unit body , 37 ... bearing, 38 ... sleeve, 39 ... bolt, 40 ... thrust receiving washer, 41 ... bearing, 42 ... sleeve, 43 ... oil seal housing, 44 ... oil seal, 45 ... idle control lever, 46 ... oil seal, 47 ... Bearings, 48
... Thrust receiving washer, 49 ... Throttle lever, 50
... Lever return spring, 51 ... Stopper boss, 52
… Deceleration opening stopper, 53… Engagement piece, 54… Receiving piece, 55…
Deceleration opening screw, 56… Lock nut, 59… Stop screw, 60… Idle opening setting diaphragm, 61…
Fuel tank, 62… Fuel supply tube, 63… Tube, 64
… Idle solenoid, 65… Tube, 66… Fitting, 67…
Tube, 68… Air cleaner, 69… Check valve, 70
... Tube, 71 ... Slow jet control solenoid, 72 ...
Tube, 73 ... Tube, 74 ... Throttle opening sensor, 75 ... Pulser, 76 ... Pulser, 77 ... Water temperature gauge, 78 ... Shift drum, 79 ... Shift position sensor, 80 ... Electronic control unit, 81 ... Clutch switch, 82 ... Side stand switch, 83… combination switch, 84… kill switch, 85… bellows telescopic tube, 86… electromagnetic solenoid.

Claims (7)

[Claims] 1. An exhaust passage opening ratio adjusting unit, wherein the opening ratio of an exhaust passage is adjusted by the exhaust passage opening ratio adjusting unit to control a compression start cylinder pressure. In a spark ignition type two-stroke internal combustion engine in which fresh air burns by self-ignition, a throttle valve, throttle valve operating means for opening and closing the throttle valve by manual operation, interposed in the throttle valve and the throttle valve operating means, A throttle adjusting means for driving the throttle valve by a predetermined amount in the closing direction or in the opening direction in response to a control signal of the control means without affecting the operation amount or operating force of the throttle valve operating means; The control signal is sent to the throttle adjusting means so as to drive the throttle valve in the closing direction and to drive the throttle valve in the opening direction in another operation region different from the certain operation region. Throttle valve control device for two-stroke internal combustion engine, characterized by comprising a control means for outputting. 2. The throttle valve adjusting means includes: an input member connected to the throttle valve operating means; an output member movable relative to the input member by a predetermined amount and connected to the throttle valve; 2. A spark ignition type two-stroke internal combustion engine according to claim 1, further comprising a relief drive mechanism for opening and closing said output member with respect to said input member in accordance with the presence or absence of output of a control signal from said control signal. Engine throttle valve controller. 3. The relief drive mechanism operates with an elastic member for urging the output member in one direction and an output of a control signal from the control means, and overcomes an elastic restoring force of the elastic member. 3. The throttle valve control device for a spark ignition type two-stroke internal combustion engine according to claim 2, further comprising an actuator for driving an output member. 4. The certain operation region is a high-speed engine rotation region exceeding a predetermined rotation speed, and the other operation region is
The throttle valve control device for a spark ignition type two-stroke internal combustion engine according to any one of claims 1 to 3, wherein the low speed machine rotation region is equal to or lower than the predetermined rotation speed. 5. The spark ignition type 2 according to claim 4, wherein an engine rotation region in which the throttle valve is driven by a predetermined amount in the opening direction with respect to an operation position of the throttle valve operation means is an idling rotation region. Throttle valve control device for a cycle internal combustion engine. 6. The spark ignition type 2 according to claim 3, wherein the actuator is a diaphragm, and atmospheric pressure or intake negative pressure is selectively introduced into a diaphragm chamber of the diaphragm by an electromagnetic switching valve. Throttle valve control device for a cycle internal combustion engine. 7. The throttle valve control device according to claim 1, wherein the internal combustion engine is a vehicle internal combustion engine mounted on a vehicle.