JPH0411730B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device that electrically controls a throttle valve of an internal combustion engine.

(Prior Art) Generally, in this type of device, the throttle valve 3 is supported by a back spring 8 as shown in FIG.
It is always urged in the fully closed direction by the urging force of. The spring force of the back spring 8 is normally set to be greater than the static torque of the control motor 2, so even if the control circuit of the control motor 2 fails, the internal combustion engine is controlled in the direction of stopping. It is becoming more and more common. Conventionally, this type of technology has been
14834 and JP-A-51-138235 have been proposed.

(Problems to be Solved by the Invention) However, such a configuration has the following problems.

In other words, when starting an internal combustion engine (hereinafter referred to as engine), it is necessary to open the throttle valve 5 to the required opening degree. However, if the battery voltage decreases when starting the engine, the spring force of the back spring 8 will decrease. The problem was that the motor torque could not be generated to overcome the problem, and the throttle valve 5 would not open sufficiently, making it difficult to start the engine.

Further, even if the throttle valve 5 opens to a predetermined opening degree at the time of starting, the battery voltage decreases when the starter motor is started at the time of starting the engine, so that sufficient current is not supplied to the control motor 2. This caused problems such as the opening state of the throttle valve 5 becoming unstable.

Furthermore, in the conventional configuration, when the engine is stopped, the throttle valve 5 is always kept fully closed by the back spring 8, so if the throttle shaft 4 of the throttle valve 5 freezes in a cold region, etc. In this case, it became impossible to open the throttle valve 5, and there was a possibility that problems such as the engine being unable to start would occur.

(Object of the Invention) In view of the above, the present invention provides an internal combustion engine capable of applying a biasing force to the throttle valve in the direction of closing it, while always ensuring the opening degree of the throttle valve necessary for starting the engine. The object of the present invention is to provide an electric control device for a throttle valve in a vehicle.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes an accelerator sensor that converts the amount of depression of the accelerator into an electrical signal, and a control motor that operates according to the signal from the accelerator sensor. In an internal combustion engine having a control circuit for controlling rotation and a throttle valve whose opening/closing amount is adjusted by the rotation of the control motor, the throttle valve is biased by a back spring to a predetermined opening degree. When the ignition switch is turned off, the throttle valve is returned to a predetermined angle by the biasing force of the back spring, and then the throttle valve is moved from this predetermined angle to start the engine. It is characterized by a configuration in which the rotation is controlled to the required opening degree.

(Example) Hereinafter, an example of the present invention will be specifically described based on the drawings.

In FIGS. 1 and 2, reference numeral 1 indicates an intake pipe 1 formed in a cylindrical shape and forming a part of an intake system. A throttle valve 5 is provided at a predetermined position in the intake pipe 1 so as to be rotatable by a throttle shaft 4. A driven gear 3 is fixed to the left end of the throttle shaft 4 in the drawing, and this driven gear 3 is meshed with a drive gear 2a provided on the output shaft of the control motor 2.
Therefore, the opening degree of the throttle valve 5 can be adjusted by controlling the rotation of the control motor 2, so that the effective area of the intake passage of the intake pipe 1 can be controlled to adjust the amount of intake air. I can do it. In this example, a step motor is used as the control motor 2.

Next, a relief lever 6 is inserted into the right side of the throttle shaft 4 in the drawing. This relief lever 6 includes a support portion 6a formed in a cylindrical shape,
It consists of an engaging piece 6b and an abutting piece 6c fixed to the upper end portion (the right end portion in FIG. 1) of the support portion 6a.

A side housing 1a is provided on the side of the intake pipe 1.
It is integrally formed, and a screw 9 is screwed into a screw hole provided therein. The tip of this screw 9 (the left end in FIG. 2) is designed to come into contact with the abutment piece 6c, so by adjusting the rotation of this screw 9, the abutment piece 6c can be returned. The position can be adjusted.

A back spring 8 is inserted into the outer periphery of the support portion 6a of the relief lever 6. and,
One end of this back spring 8 is fixed to a part of the side housing 1a, and the other end is engaged with the engagement piece 6c. Therefore, the relief lever 6 is biased in the direction into which it comes into contact with the screw 9.

Next, a throttle lever 7 is fixed to the right end of the throttle shaft 4 in the drawing. An abutting piece 7a is provided at the tip of the throttle lever 7 (lower in FIG. 1), and the abutting piece 7a can come into contact with the engaging piece 6b. Therefore, the abutting piece 7a indirectly receives the urging force from the back spring 8 via the engaging piece 6b, so that the throttle valve 5 is always urged in the closing direction. However, since the rotation of the contact piece 6c is restricted by the screw 9, the biasing force of the back spring 8 is applied to the throttle valve 5 up to a predetermined opening degree; (from the predetermined opening degree to the fully closed state) is not affected by the back spring 8.

Subsequently, the control circuit 20 in this embodiment will be explained.

The control circuit 20 is mainly composed of a CPU 26, which is provided with I/O ports 22, 23 and a ROM 27 containing a program.
The I/O port 22 has an A-D converter 21.
is connected to the I/O port 23, and a motor drive circuit 24 is connected to the I/O port 23.

The A-D converter 21 includes an accelerator sensor 10.
is connected. The accelerator sensor 10 is provided on an accelerator (not shown) of a vehicle, and is made up of, for example, a variable resistor, and is configured to output a voltage value proportional to the amount of depression of the accelerator (not shown). And this voltage is A
- Converted from analog to digital by the D converter 21 and sent to the CPU 26 via the I/O port 22
is input to.

The motor drive circuit 24 includes a control motor 2.
is connected, and the control motor 2 is rotated by a control signal from the CPU 26.

The constant voltage circuit 25 is for stabilizing the voltage from the battery 27, and is supplied with current from the battery 28 via the ignition switch 11. Note that a delay switch 12 is provided between the constant voltage circuit 25 and the battery 28 in addition to the ignition switch 11, so that even after the ignition switch 11 is turned off, the delay switch 12 remains in operation. Current is supplied to the voltage circuit 25 for a predetermined period of time.

Next, the action and effect will be explained. first,
When an accelerator opening signal is input from the accelerator sensor 10, this signal is converted from analog to digital by the A-D converter 21 and then sent to the I/O.
It is input to the CPU 26 via the port 22. Then, the CPU 26 sends a signal corresponding to this input signal to the motor drive circuit 24 via the I/O port 23.
Therefore, the motor drive circuit 24 outputs a predetermined number of pulses according to this signal to rotate the control motor 2. Then, this rotation is driven by drive gear 2.
a and the throttle shaft 4 via the driven gear 3.
The throttle valve 5 is opened to a predetermined opening degree.

At this time, the throttle lever 7 fixed to the end of the throttle shaft 4 is also rotated at the same time, so its abutting piece 7a abuts the engaging piece 6b and resists the biasing force of the back spring 8. Rotate the relief lever 6. Therefore, the throttle shaft 4
Since a return torque is applied by the back spring 8 to the throttle valve 5, the throttle valve 5 always rotates in the closing direction when the current supply to the control motor 2 is released. That is,
As a result, even if the control circuit 20 should fail, the engine will either stop or be controlled to a lower rotational speed.

By the way, the throttle valve 5 is rotated in the closing direction by the biasing force of the back spring 8 as described above, but the relief lever 6
When rotated to a predetermined angle, the screw 9 engages the contact piece 6c.
Rotation is restricted by contact with. Then, in this state, the throttle valve 5 is not in a fully closed state but in a state in which it is opened by a predetermined amount, and the abutting piece 7a is pushed by the engaging piece 6b. From the state in which the throttle valve 5 is opened by a predetermined amount, the throttle valve 5 can freely move without being affected by the biasing force of the back spring 8. (However, this is within the range of the opening amount from when the contact piece 7a comes into contact with the engagement piece 6b until the throttle valve 5 is fully closed. From now on, this will be referred to as the initial starting opening. Therefore, in the above-mentioned initial starting opening range, even if the drive current of the control motor 2 is cut off, the throttle valve 5 maintains the current opening due to the stopping torque of the control motor 2 when the control motor 2 is not energized. You will be able to do it. Therefore, in this example, after the engine is stopped, the control circuit 20 performs the following control.

That is, when the ignition switch 11 of the engine (not shown) is turned OFF, this is determined in step 101 of the flowchart shown in FIG. 4 (this flowchart is set in the ROM 27 as a program), and if YES. Proceeding to the next step 102, the accelerator control is released. (Specifically, this process is to cancel the signal related to the amount of accelerator depression from the accelerator sensor 10.)
If the determination at step 101 is NO, the process returns to the main routine, for example. And this step 102
When the processing is completed, the process advances to the next step 103.

Note that the ignition switch 11 is
If it is turned off, the control circuit 20 will also be energized.
However, in this example, a delay switch 12 is provided to prevent this, so even if the ignition switch 11 is turned off, the delay switch 12 does not supply current to the control circuit 20 for a predetermined period of time. It looks like it will be supplied.

Next, in step 103, the pulse counter in the CPU 26, which holds the current position of the control motor 2 (that is, the opening amount of the throttle valve 5) in pulse numbers, is 0. Determine whether or not.

Note that the state where the pulse counter is 0 is not based on the case where the throttle valve 5 is fully closed, but is based on the position where the throttle valve 5 is opened to the opening degree necessary for starting the engine. (hereinafter referred to as engine starting opening) corresponds to pulse counter 0.

Returning to step 103 again, if this judgment is NO, the throttle valve 5 is not at the engine starting opening, so the process proceeds to step 104, where the deviation between the current value of the pulse counter and 0 is calculated. Next, the process advances to step 105 to send a pulse signal corresponding to the deviation to the motor drive circuit 24.
Output for. Then, the control motor 2 rotates forward or reverse to move the throttle valve 5 to the engine starting opening position.

Incidentally, when the judgment in step 103 is NO, the throttle valve 5 is already at the engine starting opening position, so the control motor 2 is de-energized and the control is terminated. (Or move to the main routine, etc.) When the above control is completed, the throttle valve 5
is set to the engine starting opening, and this opening state is maintained even when the ignition switch 11 is in the OFF state, so the engine can be started with the optimal opening state the next time the engine is started. That's why.

Here, the processing of the pulse counter when the engine is started will be explained based on FIG. 5.

As mentioned above, ignition switch 11
When turned off, the throttle valve 5 is automatically set to the engine starting opening position. Since this engine starting opening position corresponds to 0 on the pulse counter, when the ignition switch 11 is turned on, the following initial settings are performed.

That is, first, in step 201, it is determined whether the ignition switch 11 has been turned on. If the answer is NO, step 201 is repeated until the ignition switch 11 is turned on, and when it is turned on, the process proceeds to the next step 202 and the pulse counter is cleared to zero. In other words, when the engine starts, the throttle valve 5 is at the 0 position of the pulse counter, so by clearing the pulse counter to zero, the number of pulses on the pulse counter and the current position of the throttle valve 5 can be calculated. It is possible to match them.

Therefore, when this step 202 is completed, the initial setting of the opening degree of the throttle valve 5 and the count number of the pulse counter is completed, and the process proceeds to step 203 to perform normal accelerator control, that is, to adjust the output signal of the accelerator sensor 10. Therefore, control can be performed to adjust the opening amount of the throttle valve 5 in accordance with the above.

(Effects of the Invention) As explained above, in the present invention, the throttle valve is biased by the back spring until it reaches a predetermined opening degree, and then the ignition switch is turned off.
After the throttle valve is opened, the control circuit can control the rotation of the throttle valve from the predetermined opening degree to the opening degree necessary for starting the engine. The present invention has an excellent feature in that it can provide an electric control device for a throttle valve in an internal combustion engine, which can always maintain the opening degree of the throttle valve necessary for starting the engine while applying force.

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention. FIG. 1 is a sectional view mainly showing the vicinity of the intake pipe 1 in this embodiment, and FIG. 2 is a right side view of FIG. 1. figure,
Figure 3 is a block diagram mainly showing the control circuit in this example, and Figure 4 shows the ignition switch.
A flowchart showing the flow of control for controlling the throttle valve to a predetermined opening degree after the ignition switch is turned OFF.
FIG. 6 is a flowchart showing a control procedure for initializing the control circuit after initialization, and FIG. 6 is a sectional view showing a conventional example. 2...Control motor, 4...Throttle shaft,
5... Throttle valve, 6... Relief lever, 7
...Throttle lever, 8...Back spring, 9
...screw, 10...accelerator sensor, 11...ignition switch, 12...day delay switch, 20
...control circuit.

Claims (1)

[Claims] 1 An accelerator sensor that converts the amount of accelerator depression into an electrical signal, a control circuit that controls the rotation of a control motor according to the signal from the accelerator sensor, and an opening/closing amount that is adjusted by the rotation of the control motor. An electrical control device for a throttle valve in an internal combustion engine, which has a relief lever biased in a predetermined rotational direction by a back spring, and a rotation of the relief lever is limited at a predetermined angle. and screws for
and a throttle lever fixed to the throttle shaft of the throttle valve, the throttle lever being fixed to the throttle shaft of the throttle valve, to which the biasing force of the back spring is applied indirectly through the relief lever;
A delay switch supplies current for a predetermined time after the ignition switch is turned off, and the throttle valve is returned to a predetermined angle by the biasing force of the back spring when the ignition switch is turned off. 1. An electrical control device for a throttle valve in an internal combustion engine, comprising means for controlling the rotation of the throttle valve from the predetermined angle to an opening necessary for starting the engine.