JPS5918127Y2 - Engine idle speed control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine speed control device for suppressing as much as possible an abnormal increase or decrease in engine speed caused by changes in ignition timing when the engine is idling.

Conventionally, when turning the cooler on and off during idling or advancing the ignition timing to prevent overheating, the engine speed fluctuates greatly.For example, if the engine speed drops and the engine cannot maintain the proper idle speed N, This can lead to increased vibration due to unstable engine rotation, worsening of exhaust gas conditions, and overheating due to insufficient engine cooling capacity due to a decrease in the rotation speed of the main cooling fan.
There is a risk of

Additionally, if the engine exceeds the appropriate idle speed N, fuel consumption may increase, engine braking effect during deceleration may decrease, and problems such as creep may occur in torque converter vehicles. Therefore, it has been considered important to configure the engine so that the engine speed does not deviate from the proper idle speed N as much as possible during idling operation, in order to improve marketability.

The present invention has been proposed in view of the above, and is a throttle system equipped with a driving negative pressure chamber that is connected to an engine throttle valve and adjusts the throttle opening degree when the engine is idling according to the supply and discharge of negative pressure in the engine intake system. Valve control device, ignition timing control device equipped with a retard side negative pressure chamber and an advance side negative pressure chamber,
A negative pressure passage has one end connected to the intake system of the engine and the other end communicated with the drive negative pressure chamber and the retard side negative pressure chamber, respectively, and is inserted in the negative pressure passage so that the engine reaches a predetermined high temperature or higher. a temperature control valve that opens when the negative pressure chamber is opened to conduct the atmosphere to the retard side negative pressure chamber through the same negative pressure passage; an atmospheric communication section provided in a negative pressure passage that communicates only with the drive negative pressure chamber;
Disposed in relation to the atmospheric communication part in the negative pressure passage that communicates only with the drive negative pressure chamber, and depending on the operating state of the cooler, either one end side of the negative pressure passage or the atmospheric communication part The gist is an engine idling speed control device characterized by having a switching valve means that connects one side to the other end of the same negative pressure passage, and is capable of turning the cooler on and off during idling, and controlling the ignition timing to prevent overheating. This prevents the engine speed from fluctuating greatly when the engine speed is advanced.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. 1. 1 is an intake pipe in an engine carburetor, 2 is a throttle valve, and 3 is a manifold that opens into the intake pipe 1 slightly downstream of the throttle valve. Negative pressure passage for boost,
Reference numeral 4 indicates a negative pressure passage for device boost that opens into the intake pipe 1 slightly upstream of the throttle valve 2, and reference numeral 5 indicates an ignition timing control device, which includes a retard side negative pressure chamber 6 and an advance side negative pressure chamber. 7, diaphragms 9 and 9' integral with the adjustment rod 8;
isolated by.

Further, the retard side negative pressure chamber 6 communicates with the negative pressure passage 3, and the advance side negative pressure chamber 7 communicates with the negative pressure passage 4, respectively.

10 and 10' are coil springs provided on the diaphragms 9 and 9', respectively.

11 is a temperature control valve communicated with the negative pressure passage 3;
Temperature sensor 13 installed in the engine cooling water passage 12
When the cooling water temperature exceeds a predetermined temperature, the atmospheric air inflow hole 14 and the negative pressure passage 3 are communicated with each other, and when the temperature is below a predetermined temperature, communication between the two is cut off.

Reference numeral 15 denotes a throttle valve control device that includes a negative pressure chamber 16 communicating with the negative pressure passage 3, and the negative pressure chamber is isolated from the atmosphere by a diaphragm 18 that cooperates with a coil spring 17.

The diaphragm 18 is interlocked with the throttle valve 2 via an actuation rod 19 and a link 20.

Further, 21 is a negative pressure chamber 1 of the throttle valve control device 15.
This is a three-way solenoid valve provided midway through the negative pressure passage 3 that communicates only with the negative pressure passage 6, and includes a valve rod 26 that opens and closes the negative pressure passage 3 and the atmospheric air flow hole 22.

23 is a cooler compressor electrically connected to the solenoid of the three-way solenoid valve 21, 24 is a switch, and 25 is a power source.The three-way solenoid valve 21 closes the atmospheric air flow hole 22 when the cooler is activated, and also closes the negative pressure passage. 3 is opened, and the atmospheric air flow hole 22 is opened when not in operation, and the negative pressure passage 3 is opened.
is configured to occlude the

According to the above configuration, under normal conditions when the engine is idling and the cooler is not operating, and the engine is not overheating, the three-way solenoid valve 21 opens at the same time as the valve rod 26 closes the negative pressure passage 3. 22 is opened, the negative pressure chamber 16 of the throttle valve control device 15 becomes atmospheric pressure, the throttle valve 2 is biased toward the closing side by the spring 17, and its opening becomes the minimum idle opening. 11 is closed, the negative pressure from the intake pipe 1 acts on the negative pressure chamber 6 of the ignition timing control device 5 via the negative pressure passage 3 to retard the ignition timing.

As a result, the engine speed becomes the appropriate idle speed N.

When the cooler operates in this state, that is, in an idle state without overheating, the valve stem 26 of the solenoid valve 21 closes the atmospheric air flow hole 22 and opens the negative pressure passage 3, so that the negative pressure from the intake pipe 1 is transferred to the negative pressure passage 3. act on the negative pressure chamber 6 of the ignition timing control device 5 and the negative pressure chamber 16 of the throttle valve control device 15, respectively, to retard the ignition timing and at the same time act against the biasing force of the spring 17 to act on the operating rod 19 together with the diaphragm 18. is raised to increase the opening degree of the throttle valve 2 from the minimum idle opening degree to the maximum idle opening degree.

In this case, the decrease in engine speed due to the operation of the cooler during idle can be compensated for by the increase in engine speed due to the increase in the opening of throttle valve 2, so the engine speed is adjusted to approximately the appropriate idle speed N. .

Next, when the engine overheats when the cooler is activated during idling, and the water temperature in the water jacket 12 rises and exceeds a predetermined temperature, the air flows into the negative pressure passage 3 through the air inflow hole 14 with the water temperature control valve 11 opened. , the negative pressure chamber 6 of the ignition timing control device 5 becomes atmospheric pressure, and the force due to atmospheric pressure acting on the diaphragm 9 and the coil spring 1
The adjustment rod 8 is pushed down together with the diaphragm 9 with a biasing force of 0 to advance the ignition timing, thereby preventing overheating of the engine and reducing the negative pressure chamber 16 of the throttle valve control device 15.
The pressure also becomes atmospheric pressure, and the actuating rod 19 is pushed down together with the diaphragm 18 by the biasing force of the spring 17, and the throttle valve 2 is throttled to the minimum idling opening.

In this case, the increase in engine output due to the advance of the ignition timing can be compensated for by the decrease in engine output due to the smaller opening of the throttle valve 2, so the engine speed will be approximately The idle speed N is maintained at the appropriate idle speed.

Next, when the cooler becomes inoperable in the overheat I state during idle operation, the valve stem 2 of the three-way solenoid valve 21
6 closes the negative pressure passage 3 and opens the atmospheric air flow hole 22, but at this time, the atmosphere is still communicated to the negative pressure passage 3 via the water temperature control valve 11, and the negative pressure chamber 16 of the throttle valve control device 15 Since the atmosphere is supplied from the atmosphere ventilation hole 22 to both of the cases, the opening state of the throttle valve 2 and the state of the ignition timing are the same as in the case of overheating when the cooler is operating. In the case of overheating during operation, the engine load is reduced by the amount that the cooler load is removed compared to the case of overheating when the cooler is operating, and as a result, the engine speed is slightly lower than the appropriate idle speed N ( (increases by the amount that the cooler load is removed).

Therefore, according to this embodiment, with a simple and inexpensive configuration, it is possible to control the engine idling state such as when the engine is in a normal operating state where it is not overheated, when the cooler is operating, and when the engine is overheated and in a constant state. Under most operating conditions, the idle speed is approximately appropriate (i.e., high enough to avoid increases in vibration, deterioration of exhaust gas conditions, lack of engine cooling capacity due to a drop in main cooling fan speed, etc.), and fuel efficiency. It is possible to obtain an optimum idle speed (N) that is low enough to not cause any deterioration.

Further, according to this embodiment, in an operating state in which the appropriate idle rotation speed N cannot be obtained, that is, in an overheating state when the cooler is not operating, the engine rotation speed is made to rise above the appropriate idle rotation speed N, This has the effect of increasing the number of rotations of the main cooling fan, thereby promoting overheating and sometimes cooling the engine.

Therefore, it is possible to provide an engine with high marketability by using the device of the present invention, which maintains a proper rotational speed in many operating states when the engine is idling, and prevents harmful effects caused by abnormal rotational fluctuations, with an inexpensive configuration. be.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the present invention.

Claims (1)

[Scope of utility model registration request] Thrower I when the engine is idling in response to supply and exhaust of negative pressure in the engine intake system connected to the engine throttle valve
・Throttle valve control device equipped with a driving negative pressure chamber that adjusts the valve opening, ignition timing control device equipped with a negative pressure chamber on the retard side and a negative pressure chamber on the advance side, one end connected to the engine intake system, and the other end connected to the engine intake system. A negative pressure passage whose ends communicate with the drive negative pressure chamber and the retard side negative pressure chamber, respectively, and a negative pressure passage which is interposed in the negative pressure passage and opens when the engine reaches a predetermined high temperature or higher. A temperature control valve that communicates the atmosphere to the retard side negative pressure chamber via a temperature control valve that communicates only with the drive negative pressure chamber among the negative pressure passages that communicate with the drive negative pressure chamber and the retard side negative pressure, respectively. An atmospheric communication part provided in the negative pressure passage, which is arranged in relation to the atmospheric communication part in the negative pressure passage that communicates only with the drive negative pressure chamber, and which is connected to one end of the negative pressure passage depending on the operating state of the cooler. 1. An idle speed control device for an engine, comprising a switching valve means for communicating either one of the side and the atmosphere communication portion with the other end of the negative pressure passage.