JPS5910767A - Mixture regulator of carburetor - Google Patents

Abstract

PURPOSE:To simplify construction of a device, by controlling an opening of choke and throttle valves in accordance with the condition of an engine through two sheets of cams provided to an output shaft of a reversely rotatable electric motor and promptly performing warming operation of the engine at a stable idle speed. CONSTITUTION:If temperature of an engine rises, a sensor output is increased, and an output of a comparator 127 becomes ''1'', while if speed of the engine is increased, similarly an output of a comparator 132 becomes ''1''. Accordingly, when an output of an accelerator switch alarm 128 becomes ''1'', a flip-flop 146 is set, and a memory selector 139 selectively operates an idle speed correcting memory 136 to drive a motor 142. That is, transfer to idle operation is performed during the ON-time of an accelerator switch, and since a throttle opening is not decreased to a minimum value of a home position but set to an idle initial value in a hot range, a stable idle speed is obtained. Further the engine transferred to a hot condition is not returned to a cold condition unless otherwise stopped, and the engine is promptly warmed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mixture adjustment device for a carburetor, and in particular, a choke valve is provided on the upstream side of the intake passage, and a throttle valve is provided on the downstream side thereof, with the penticoli portion where the main fuel nozzle opens as the border. In the installed carburetor, two cams fixed to the - motor output shaft or its reduction type output shaft,
The present invention relates to a mixture adjustment device for a carburetor that controls the opening degrees of the choke valve and the throttle valve.

More specifically, the present invention provides that the transition of the motor from the reverse rotation side to the forward rotation side beyond the home position requires at least (1) engine humidity to be equal to or higher than the cold boundary temperature; (2) ) The engine speed is equal to or higher than a predetermined value; and (3) the throttle lever is mechanically warmed up by the second rotary cam means. Once the engine has transitioned to a hot state, the carburetor is configured to prohibit the electric motor from moving from the forward rotation side past the home position to the reverse rotation side unless engine stoppage is detected. This invention relates to a mixture adjusting device.

In a carburetor as described above, in which a choke valve is installed on the upstream side of the intake path and a throttle valve is installed on the downstream side of the intake path, with the ventilator part where the main fuel nozzle opens as a boundary, the choke valve has a fully open position. A first rotary cam means that can operate the throttle valve from 71 to a fully open position is interlocked, and a second rotary cam means that can operate the throttle valve to a predetermined 71-stroke idle degree is interlocked with the throttle valve. A mixture adjustment device for a carburetor, in which a second rotary cam means is connected to an electric motor whose rotational position is determined depending on the operating conditions of the internal combustion engine, the electric motor having a home position as its boundary. The first and second rotating cam means maintain the choke valve at a substantially fully open position when the electric luxury engine rotates forward from the home position, while the throttle valve maintains the throttle valve at a substantially fully open position. Also, when the electric motor is reversed from the home position, the buyoke valve decreases its opening, while the ``s'' valve increases its opening. The structure and operation of the carburetor part of the conventional carburetor air-fuel mixture adjustment device, whose shape is selected as shown in FIG. has been done.

An object of the present invention is to provide a mixture adjustment device for a carburetor of an internal combustion engine, which controls the opening degrees of the choke valve and throttle valve of the conventional carburetor according to the engine condition. .

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a 7L1-chip diagram for explaining its operation. The operation of this embodiment will be described in detail below with reference to FIGS. 1 and 2.

When the ignition switch (not shown) is turned on when starting the engine, the ignition switch detector 12
4 detects this, and according to the output of the jump detection circuit 130, the first control flop 145 is turned on.

This closes the first AND gate 149. Further, since the first flip-flop 145 is set to cell 1, the memory selector 139 selects the fifth memory 137.

On the other hand, at this point, in step S1 of FIG. 2, the open/closed state of the home position switch (not shown) is determined.

For example, if the home position switch is closed, the home position switch detector 125 will be 1".
This (fi number) is applied to the output controller 141 via the first AND gate 149.As a result, the output controllers 1 to L1-141 output a pulse in the direction of reversing the stepping motor 142. Ruru (2nd
Step 82> in the figure.

When the stepping motor rotates in reverse, the stepping motor 142 passes through a predetermined Baum position, and the home position switch is now opened.

As a result, the output of the home position switch detector 125 becomes 0'', and the first AND gate 149 is closed.As a result, the output controller 141 outputs a pulse that causes the stepping motor 142 to rotate forward (as shown in FIG. Step 83).

When the stepping motor 142 rotates normally, the time point at which the small position switch changes from open to closed is determined (step S4 in FIG. 2).

In the circuit of FIG. 1, this change is detected by the first differential circuit 131, the first flip-flop 145 is reset, and the first flip-flops 1-149 are closed.

Note that in the determination in step S1, the home position switch is closed and C1. If r l-J, the output of the first AND gate 149 is 0, so the stepping motor 142 rotates in the normal direction, and when it reaches the home position, the home position switch changes from open to closed, and the above-mentioned The same operation is performed.

On the other hand, at the same time that the 17th lip-flop 145 is reset by the output of the first differentiating circuit 131, the preset value (value for initial setting) of the fifth memory 137 becomes U/
, is set in the D counter 143.

In this step, the initialization of this device is completed. That is, the Bauhm position of the stepping motor 1/12 and the preset value (initial value) of the (''/D counter 143) are accurately matched (step 85 in FIG. 2).At the same time, the step in FIG. In S5, Bot 1~
The flag is reset.

When initialization is complete, engine speed sensor 1
The output of No. 21 is added to the complete explosion detector and delay circuit 126, and it is determined that the complete explosion state has not been reached - that is, that the engine speed Ne is smaller than the set value NeO. Step S6 in Figure 2).

Further, the output of the engine temperature sensor 123 is compared with its set value °[O by a first comparator 127 to determine whether the engine is in a cold state or a hot state (steps in FIG. 2). 87).

When the engine temperature is lower than the set value TO of the first comparator 127 and is in a cold state, the first comparator 1
The output of 27 is 0'' and (2, 27th lip-flop 14
6 is reset to 1~. Depending on the taste, the memory selector 139 selects the first and second cold start 133 (
88 in Figure 2).

Since the first memory 133 stores the rotational position data of the stepping motor 142 corresponding to the engine temperature, the data optimal for the engine temperature at that time is output and supplied to the third inverter 140.

The third comparator 140 outputs the data LJ/D (
(up/down) counter 143 and outputs an output according to the difference.
On the other hand, they are supplied to the hit J/D counter 143 as a forward/reverse signal and an up/down run 1- signal, respectively.

Thereby, the stepping motor 142 is rotated to a position equal to the read data of the first memory 133.

Therefore, the cam plate (not shown) fixed to the output shaft of the stepping motor 142 rotates, and the choke valves J, B-L valves (none of which are shown) are connected to each cam. As the engine rotates, the optimal opening for cold starting is set depending on the engine temperature at that time (steps S8→S11→533 in FIG. 2).

FIG. 3 shows an example of the relationship between the rotational position of the stepping motor 142 and the opening degrees of the choke valve and throttle valve.

In the figure, the horizontal axis indicates the rotational position of stepping 142, and the Δ mark indicates the Baum position. The vertical axis represents the opening degree T11 of the throttle valve and the opening degree ch of the choke valve.

As is clear from this, if the stepping motor 142 is rotated in the opposite direction from the Baum position, a valve opening suitable for a cold state can be obtained. If the valve is rotated in the forward direction, a valve opening suitable for hot conditions can be obtained.

Further, in the determination in step S7 of FIG. 2, if the engine temperature is higher than the set value TO of the 1-1st comparator 127, the engine is in a hot state.

At this time, the output of the first comparator 127 becomes 1'', and in response, the memory selector 139 selects the third memory 135 for hot starting, and sets the flag to cell 1 (see Fig. 2). step S9→510).

The third memory 135 stores rotational position data of the stepping motor 142 for hot starting, and this data is supplied to the third comparator 140. To this,
In the same way as described above, the stepping motor 142
It is rotated to a position equal to the read data of the memory 135 (steps S9→S10→S11→533 in FIG. 2).
.

If the starter switch (not shown) is closed in this state, the engine will start and its rotational speed will rise to 7.
Ru.

] - The engine rotational speed is detected by the engine rotational speed sensor 121, and a complete explosion detector and delay circuit 126 determines whether the engine has reached a complete explosion state.

That is, as shown in step S6 in FIG. 2, it is determined whether the engine speed NO is greater than the stall detection values N and eo.

Steps S6 → S7 → S8 → S until the state of complete explosion
11→833 loop or step S6→S7
→S9→S10→811→333 loop cannot be repeated.

When the complete explosion state is reached, the determination in step S6 is established, so the process proceeds to step S2'l. Then, after the complete explosion delay time has elapsed, the process proceeds to a hot-up 822, and it is determined whether the hot flag is set.

When the engine is started in a cold state, the hot flag is not turned on, so proceed to step S24 and determine whether the engine temperature has risen above the cold boundary temperature TO. .

If the engine temperature is less than or equal to the cold boundary temperature range 0, the process proceeds to step S25 and the second memory 134 for warm-up is selected. This means that in the device shown in FIG.
1, the memory selector 139 selects the second memory 134.

As is clear from FIG.
3 is supplied as a parameter, and rotational position data of the stepping motor 142 is read out.

Then, as described above, according to this read data -
(The stepping motor 142 is driven, and the opening degree control of the choke valve and throttle valve is executed (step 533 in FIG. 2).

As the engine continues to rotate, its temperature gradually increases. If the engine temperature increases by 11 degrees before the determination in step 824 of FIG. .

If the accelerator switch is not closed, step 82
5, the process proceeds to step 333 and the above-described operations are repeated.

When the accelerator switch is closed, step 8
Proceed to 27. Then, it is further determined whether the engine rotation speed No is larger than a predetermined value Ne+. If the determination is not established, the process similarly advances to steps 825 and 833 to execute a warm-up cycle.

When the determinations in steps 826 and 827 are established, the process proceeds to step 828. That is, the idle initial value stored in the sixth memory 138 in FIG. 1 is read out, the process proceeds to step 829, a hot flag is set, and further step S33'('controls the rotational position of the stepping motor.

The above operations are performed as follows in FIG.

When the engine temperature rises, the engine wetness sensor 123
The output of the first comparator 127 is inverted and becomes "1". On the other hand, as the engine speed increases, the output of the engine speed sensor 121 also increases, and the output of the second comparator 132 becomes '1''.

Therefore, the output of the accelerator switch detector 128 is 1″
, the second AND gate 144 generates an output of ``1'', and the second flip-flop 146 is activated. As a result, the memory selector 139 selects the fourth memory for idle speed correction. Select King 136.

Furthermore, the selection output of the memory selector 139 is
It is also supplied to the differentiating circuit 14B at the same time, and according to its output, the 37th circuit 1) [1 circuit 1/I7 is the cell! be sent to

The output of the flip-flop 147 is inverted and supplied to the third AND gate 150, which is closed. Therefore, the read data of the fourth memory 136 is not supplied to the output terminals 1 to 141.

On the other hand, the output of the 37th lip flop 147 activates the sixth memory 138 for idle initial value setting, and the read data is supplied to the third comparator 140. In this way, the stepping motor 142 is driven to the rotation angle for setting the idle initial value stored in the sixth memory 138.

The stepping motor 142 actually rotates, and the
When the fiddle initial value is reached, the third comparator 140
An output of J,-)(3rd flip-flop 147 is re-hit).

As a result, the third andgoo h 150 is opened, so
The data in the fourth memory 136 is output from the controller 141
will be supplied to

The rotational position correction data of the stepping motor 142 is stored in the fourth memory 136 using the above-mentioned engine rotational speed as a parameter, so that the engine rotational speed deviates from the predetermined idle rotational speed. in case of,
The amount of stepping required to correct this - evening rotation,
Alternatively, the number of driving pulses is supplied to the output L1-L141.

However, even if the stepping motor 142 is driven to adjust the opening degrees of the choke valve and the thrower valves, the rotation speed does not change immediately due to the inertia of the engine. For this reason, after changing the rotational position of the stepping motor, it is desirable not to perform the next control for a certain period of time.

Step $31 in FIG. 2 is for setting such a grace period, and until the scheduled time has elapsed, the rotation angle correction of the stepping motor is not executed in step 833, and step S6 is executed again. Return to

In FIG. 1, a similar grace period can be provided by controlling the operation timing of the output controller 141 and/or the third AND gate 150 with an appropriate timer or sequencer.

If it is determined in step 831 that the scheduled time has elapsed, a timer for measuring the scheduled time is cleared in step 832, and step 833
Proceed to. Then, step 83
The fourth memory 136 is driven according to the data read from the fourth memory 136 at J5.

As described above, the transition from cold control to idle operation is performed.

In the mixture adjustment device for a carburetor according to the present invention, the following features are provided:
As is clear from the second explanation, the transition from the cold region beyond the home position to the hot region or idling region is performed while the accelerator switch is on.

For this reason, the opening degree of the throttle valve is set to the initial idle value in the hot region without decreasing to the lowest value in the home position or vicinity. c) c g-
C1 At the time of the above-mentioned transition, there is no fear that the opening degree of the throttle valve is insufficient and the rotational speed is too low or that the engine stops.

As described above, in the carburetor mixture adjustment device according to the present invention, the drive direction and drive amount of the stepping motor 142 are directly read from the memory in accordance with the deviation of the engine speed from the set value, and based on this data. Since the engine speed is controlled during idle operation, an extremely stable idle speed can be achieved.

In addition, since the throttle valve and choke valve speed can be controlled by uniaxial drive, the drawing can be simplified and costs can be reduced.

Further, once the engine has shifted to the hot state □, it does not return to the cold state control ' unless the engine is stopped, so there is an advantage that warm-up is performed quickly.

Note that the carburetor air-fuel mixture adjusting device of the present invention as described above may be modified and implemented as follows. - <11 Initial setting of the U/D counter 143 is performed at the timing when the home position switch changes from closed to open.

(2) The first memory 133 for cold starting uses the output of at least one of the intake air temperature sensor 122 and the engine temperature sensor 123 as a parameter to store the throttle valve wear.

(3) The second memory 134 for warm-up (1.1) uses at least two of the outputs of the engine rotation speed sensor 121, intake atmosphere depletion sensor 122, and engine temperature sensor 123 as parameters to control the throttle valve. Memorize the opening degree.

(4) The third memory 135 for hot starting stores the opening degree of the throttle valve using at least one of the outputs of the intake atmosphere recessed air humidity sensor 122 and the engine temperature sensor 123 as a parameter.

(5) The sixth memory 138 for setting the initial idle speed stores the opening degree of the throttle valve using at least one of the intake atmosphere and the output of the air temperature sensor 122 and the engine thirst sensor 123 as a parameter.

Further, the sixth memory 138 stores the opening degree of the throttle valve using the rotational position of the stepping motor 142 immediately before shifting to idle operation and the data of the fourth memory 136 as parameters.

(6) Instead of detecting the operation of the accelerator switch,
1. It may be detected that the lever is not engaged with the interlocking lever.

(7) The conditions for transition from the cold region to the hot region are (a) the engine temperature is higher than the planned value J, and (b) the labor rate of the engine speed is higher than the planned value. Two may be adopted.

(8) By giving a hysteresis characteristic to the set value (cold/hot boundary temperature or rate of increase in engine speed) that identifies the cold state and hot state of the engine, the cold state and hot state of the engine can be distinguished. The stepping motor 142 is prevented from hunting near the boundary.

[Brief explanation of drawings]

Fig. 1 shows an embodiment of the air-fuel mixture adjustment device for a carburetor according to the present invention. This is a chart showing the relationship between the rotational position of the choke valve (13) and the opening degree of the throttle valve. 121... Engine rotation speed sensor, 122... Intake atmosphere temperature sensor, 123... Engine temperature sensor. ,
124...Ignition switch detector, 125.
... Home position switch detector, 126 ... Complete explosion detector and delay circuit, 128 ... Accelerator switch detector, 130 ... Edge detection circuit, 133 ... First memory, 134 ... No. 2 memory, 135...3rd
Memory, 136...Fourth memory, 137...Fifth memory, 138...Sixth memory, 139...Memory selector, 1/41...Output]n1-roller, 142...
...Stepping motor, 143...U/D counter agent Michito Hiraki and 1 other person

Claims (1)

[Claims] (1) In a carburetor that has a choke valve on the upstream side of the intake path and a throttle valve on the downstream side of the venturi section where the main fuel nozzle is located, the choke valve is placed in the fully open position. A first rotary cam means that can operate from the first position to a fully open position is interlocked, and a second rotary cam means that can operate the throttle valve to a predetermined fast idle opening degree is interlocked. and second
A carburetor air-fuel mixture adjustment device comprising a rotary cam means connected to an electric motor whose rotational position is determined according to operating conditions of an internal combustion engine, wherein the electric motor rotates in the normal direction beyond a home position. and the first and second rotary cam means are configured such that when the electric motor rotates forward from the Baum position, the choke valve is held in a substantially fully open position, while the throttle valve is held in its open position. When the electric motor reverses from its home position, the choke valve decreases its opening, while the throttle valve increases its opening. The shape is selected, and the transition from the reverse rotation side of the electric motor beyond the home position to the forward rotation side of C is performed at least when the engine temperature is above the cold boundary temperature and the engine speed is above the planned value. (・The engine is mechanically separated from the second rotating cam means and the throttle lever is mechanically separated from the second rotary cam means.) The mixture adjusting device for a carburetor is characterized by comprising means for prohibiting the electric motor from moving from the forward rotation side to the reverse rotation side beyond the home position after the transition to the normal rotation state, unless an engine stop is detected.