JPH041324Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is designed to improve the drivability of an internal combustion engine when a vehicle that can be selectively switched between 4-wheel drive and 2-wheel drive drives at a slow speed with the air conditioner switch turned on. This invention relates to an idle up control device.

BACKGROUND TECHNOLOGY Vehicles that can be driven by arbitrarily switching between 4-wheel drive and 2-wheel drive using a changeover switch are widely known, but when such a vehicle is driven with the air conditioner switch turned on, for example, if the engine is When the engine is in the idle operating range, the engine driving force is used to drive the air conditioner compressor by setting the opening of the throttle valve to a slightly larger opening than the normal idle opening according to the temperature of the cooler blowing out from the air conditioner. The idle speed is set to be approximately the same as the normal idle speed or slightly higher than the normal idle speed so that the idle speed does not become unstable due to the consumed amount.

Problems that the invention aims to solve In such vehicles, even if the air conditioner switch is turned on, the air conditioner compressor idles up and cools down due to, for example, the air conditioner's cooler outlet temperature rising or falling. It ensures performance and prevents the idle speed from decreasing, and since the idle does not increase when the air conditioner compressor is not operating, the idle speed increases or decreases accordingly.

For example, when a four-wheel drive vehicle is traveling at extremely low speeds on rough roads such as rocky roads, the vehicle is driven at very low speeds by operating the brake pedal without depressing the accelerator pedal, but at this time the air conditioner switch is turned on. If the load of the air conditioner compressor acts on the engine according to the cooler outlet temperature, the idle will increase, and if it does not, the idle will not increase, and the engine speed will increase or decrease against the driver's will, resulting in poor drivability. The problem is that it gets worse.

The present invention was developed to solve these problems, and is designed to avoid deterioration in drivability when the air conditioner is switched on when driving in the idling speed range with four-wheel drive. The purpose of this invention is to provide an up control device.

Means for Solving the Problems In order to achieve the above object, the idle up control device for an internal combustion engine according to the present invention includes an air conditioner switch that instructs air conditioning in a vehicle interior, and an air conditioner that instructs air conditioning at the air conditioner switch. An idle-up control device for an internal combustion engine, which is equipped with an air conditioner compressor that is driven by the engine and is turned on and off according to the air condition in the vehicle interior when the air conditioner is turned on and off, and increases and decreases the amount of intake air in synchronization with the on and off of the air conditioner compressor. When the determining means for determining whether the vehicle is traveling in four-wheel drive or two-wheel drive determines that the vehicle is traveling in four-wheel drive and the air conditioner switch is on, the amount of idle increase is fixed regardless of whether the air conditioner compressor is on or off. Configure it as follows.

Effect According to the present invention, for example, when the driver turns on the air conditioner switch and drives in four-wheel drive, the idle up amount is fixed, so that
The amount of intake air supplied to the engine is set to be higher than the amount of intake air during normal idling operation, so
Even if the load on the engine fluctuates due to the air conditioner compressor turning on and off depending on the air condition in the cabin, the idle speed will no longer suddenly increase or decrease, making it easier to drive on rough roads such as rocky roads. Drivability during driving is improved.

Example Embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a main part of an embodiment of an internal combustion engine to which an idle-up control device according to the present invention is applied.

In FIG. 1, a carburetor 2 is provided upstream of an intake manifold 1, and a throttle valve 4 is interposed near the downstream side of a vent lily portion 3 of this carburetor 2. In the throttle valve 4, a rod 7 integrated with a diaphragm 8c moves up and down in response to control pressure introduced into a first diaphragm chamber 8a of an actuator 8, so that a link 6 connected to one end 7a of the rod serves as a fulcrum. It rotates around point a, which rotates the lever 5 and rotates the throttle valve body 4a. A second diaphragm chamber 8b on the opposite side of the first diaphragm chamber 8a via the diaphragm 8c is open to the atmosphere. Further, the first diaphragm chamber 8a includes a rod 7.
A diaphragm spring 9 is interposed to bias the diaphragm 8c in the direction of extending the diaphragm 8c.

The control pressure introduced into the first diaphragm chamber 8a is controlled by a vacuum switching valve 11 as a negative pressure control valve.
That is, when the excitation coil 12 is energized, the three-way valve 14
introduces suction negative pressure into the first diaphragm chamber 8a through the negative pressure passage 15 and the control pressure passage 10, and contracts the rod 7 integrated with the diaphragm 8c against the diaphragm spring 9, thereby causing the link 6 and the lever 5 to The throttle valve body 4a is opened by a predetermined opening degree via the throttle valve body 4a. When the excitation coil 1 is not energized, the three-way valve 14 communicates the atmospheric passage 13 and the control pressure passage 10 to introduce atmospheric pressure into the first diaphragm chamber 8a, thereby expanding the rod 7 from its contracted state. , the throttle valve body 4a is closed to a nearly fully closed state via the link 6 and the lever 5.

Whether or not the excitation coil 12 of the negative pressure control valve 11 is energized depends on whether the air conditioner switch is on or off and whether the
The decision is made based on the combination of wheel drive or not.

When the air conditioner switch is off,
One of the input signals of the AND circuit 18 becomes low level, and the output of the AND circuit 18 becomes low level, cutting off the energization to the excitation coil 12. Therefore, in this case, the throttle valve 4 is in a nearly fully closed state.

When the air conditioner switch is on,
One of the input signals of the AND circuit 18 becomes a high level, and if the vehicle is running in four-wheel drive at this time, one of the input signals of the OR circuit 19 becomes a high level, so regardless of whether the air conditioner compressor is on or off, the OR circuit The output of 19 becomes high level,
The output of the AND circuit 18 becomes high level and the excitation coil 12 is energized. The air conditioner compressor turns on or off depending on the temperature inside the vehicle (e.g. cooler outlet temperature), but in this case,
Regardless of whether the air conditioner compressor is on or off, the opening degree of the throttle valve 4 becomes a predetermined opening degree more open than the nearly fully closed condition, and the idle is increased. The fixed amount of idle up at this time is
It is set to ensure an increase in the amount of intake air to such an extent that even if the load on the engine fluctuates due to turning on and off the air conditioner compressor, the engine speed will not fluctuate.

When the air conditioner switch is on and two-wheel drive is running, one of the input signals of the OR circuit 19 becomes low level, but in this case, if the air conditioner compressor is on depending on the air condition inside the vehicle,
The output of the OR circuit 19 becomes high level, and the AND
The output of the circuit 18 becomes high level, the excitation coil 12 is energized, and the opening degree of the throttle valve 4 is set to a state slightly more open than the normal fully closed state. This increases the amount of intake air compared to normal idling, increasing the idle by the amount of load placed on the engine by driving the air conditioner.

In this way, according to this embodiment, when driving in four-wheel drive, the negative pressure control valve 11 is turned on regardless of whether the air conditioner compressor is on or off, and the opening degree of the throttle valve 4 is changed to the slot opening degree during normal idling operation. By fixing the idle up, the engine output is increased by increasing the amount of air, improving drivability when driving at slow speeds on rough roads such as rocky roads. The vehicle can run safely and stably.

Another embodiment of the invention is shown in FIG. In this embodiment, the engine speed is added to the factors for determining whether to fix the idle up, and the output signal of the engine speed detecting means is input to the AND circuit 18. When the engine speed is above the specified value, the output signal will be at low level.
The output signal of the AND circuit 18 also becomes low level, and the current to the excitation coil 12 is cut off, so that the throttle valve 4 is in a nearly fully closed state. When the engine speed is less than a predetermined value, the output signal becomes high level, but when the air conditioner is switched off, the AND circuit 18
The output signal becomes low level and the excitation coil 12 is not energized. When the air conditioner is switched on
Two of the input signals of the AND circuit 18 are at a high level, and at this time, if driving in four-wheel drive, one of the input signals of the OR circuit 19 is at a high level, regardless of whether the air conditioner compressor is on or off.
The output of the OR circuit 19 becomes high level, the output of the AND circuit 18 becomes high level, and the exciting coil 12
is energized and idle up is measured.

If the engine speed is less than a predetermined value and the air conditioner switch is on, and in the case of two-wheel drive driving, the output of the OR circuit 19 will be at a high level if the air conditioner compressor is on depending on the air condition inside the vehicle. The excitation coil 12 is energized and idled up. As mentioned above, when the engine speed is added to the determining factor for fixing the idle up, the idle up will be fixed only at low speeds, and when the engine is at high speeds, the load on the air conditioner compressor on the engine will be relatively small, resulting in There is no need to perform the necessary idle up, which improves fuel efficiency.

Effects of the invention According to the invention, when the air conditioner switch is turned on while driving in four-wheel drive, the throttle valve opening degree is slightly wider than when it is fully closed, regardless of whether the air conditioner compressor driven by the engine is on or off. Since the engine is configured to increase the amount of intake air by fixing the idle speed, even if the air conditioner compressor is turned on or off depending on the air condition in the cabin when driving on rough roads such as rocky roads, the idle speed of the engine remains constant. A stable state is maintained, and as a result, there is no sudden acceleration or deceleration against the driver's will, and good vehicle running performance can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing one embodiment of the present invention, and FIG. 2 is a schematic block diagram showing another embodiment of the present invention. 1... Intake manifold, 2... Carburetor, 4
... Throttle valve, 8 ... Actuator,
10... Control pressure passage, 11... Negative pressure control valve (VSV), 12... Excitation coil, 14... Three-way valve,
18...AND circuit, 19...OR circuit.

Claims (1)

[Scope of utility model registration request] The air conditioner compressor is equipped with an air conditioner switch that instructs air conditioning in the vehicle interior, and an air conditioner compressor that is turned on and off according to the air condition in the vehicle interior and is driven by an engine when air conditioning is instructed by the air conditioner switch. In an idle up control device for an internal combustion engine that increases or decreases the amount of intake air in synchronization with the on/off of An idle-up control device for an internal combustion engine, characterized in that when an air-conditioner switch is on, an idle-up amount is fixed regardless of whether an air-conditioner compressor is on or off.