JP2887538B2 - Engine warm-up control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine warm-up control device applicable to an automatic vehicle.

[0002]

2. Description of the Related Art A vehicle equipped with an automatic transmission (AT vehicle) is provided on a wheel without operating a clutch pedal, unlike a vehicle equipped with a manual transmission having a clutch mechanism (MT vehicle). Since the power can be transmitted, if the operation of the driver is immature or there is an operation error, the driver may suddenly start. Of course, such a situation cannot occur when an appropriate operation is performed. However, regardless of the cause of the sudden start, the sudden start occurs when the engine speed is higher than usual, such as during warm-up of the engine. A technique for preventing a sudden start of a vehicle is disclosed in Japanese Utility Model Laid-Open No. 1-58328.

The invention described in this publication discloses an AT car having an auto choke carburetor that performs high-speed first idling at the time of cold start, in which the shift range is at a position other than P and N, and the accelerator pedal is depressed. When it is not, the first idling is stopped.

[0004]

According to the technique described in the above publication, sudden start of the vehicle at the time of cold start can be prevented. However, the shift lever of the transmission is shifted to the D range or the R range to start immediately after the cold start. When shifting to the range, there is a problem that the first idling stops, the engine speed decreases, and the engine stops (stalls).

The present invention has been made in view of this point, and does not stop the engine even if the shift lever of the transmission is shifted to the D range or the R range in order to start immediately after the cold start, and does not start suddenly. The purpose of the present invention is to provide a warm-up control device.

[0006]

According to the present invention, there is provided a water temperature sensor for detecting a cooling water temperature of an engine, a rotation speed sensor for detecting a rotation speed of an engine, and A shift sensor for detecting that the shift position is in the N range, and an output signal is generated by detecting that the vehicle is running while the engine is warming up and temporarily stopping from the output signals of these sensors. The control unit includes a control unit and a mechanism that receives an output signal of the control unit and reduces the idling rotational speed.

[0007]

With this configuration, the control unit detects that the vehicle has been running while the engine is warming up and then stops and the shift position of the transmission has been switched to the N range. This acts to gradually reduce the number of revolutions. As a result, the idling speed can be associated with the warm-up progress of the engine, and both the stop of the engine and the sudden start of the vehicle can be prevented.

[0008]

FIG. 1 shows an embodiment of the present invention. 1 is an engine, 2 is an intake manifold, and 3 is an exhaust manifold. A throttle body 4 is connected to an upstream side of the intake manifold 2, and a throttle valve 5 and a coaxial throttle position sensor 6 are provided therein. 7
Is an idling passage. An injector 8 is provided upstream of the throttle valve 5, and a fuel pump 9 is provided.
Thus, the fuel 11 in the fuel tank 10 sucked up is injected toward the throttle valve 5. Numeral 12 denotes a fuel pressure adjusting valve for adjusting the injection pressure of the injector and returning surplus fuel to the fuel tank 10. 13 is an oxygen sensor and 14 is a catalytic converter.

Reference numeral 15 denotes a control unit. The control unit 15 includes a water temperature sensor 16 for detecting a temperature of a cooling water of the engine and an intake air temperature sensor for detecting an intake air temperature.
17, a rotation speed sensor 18 for detecting the rotation speed of the engine,
An output signal from the shift sensor 19 for detecting that the shift position of the transmission is in the N range and an output signal from the throttle position sensor 6 are input.
An output signal is generated by detecting that the vehicle is running while the engine is warming up and that the vehicle is temporarily stopped. On the output side of the control unit 15, an ISC valve (idling speed control valve) 20 and a throttle opener VSV (vacuum switch valve) 21
Is connected. 22 is a throttle opener.

In this device having such a configuration, the control unit 15 operates based on the output signals of the water temperature sensor 16, the rotation speed sensor 18 and the shift sensor 19 while the vehicle is warming up the engine, and thereafter stops and stops the transmission. Is detected to be switched to the N range, and acts to gradually decrease the idling speed of the engine. As a result, the idling speed can be associated with the warm-up progress of the engine, and both the stop of the engine and the sudden start of the vehicle can be prevented.

As a method of gradually lowering the idling rotation speed, the control unit 15
By giving a command to the throttle opener VSV21 and changing the opening thereof, the engine speed is gradually reduced without stopping the engine. Figure 2 Step
FIG. 3 shows the relationship between the state of the engine and the vehicle and the fuel injection amount, and FIG. 4 shows the relationship between the state of the engine and the vehicle and the engine speed. .

In FIG. 3, zone A is for the idling correction of the fuel injection amount, and zone B is for the warming-up correction. In the present invention, the warm-up increase correction amount is gradually decreased as shown by C, but is gradually decreased with time as shown in the present invention. After the warm-up, feedback control is performed as shown. The curve shown in FIG. 4 is the engine speed according to the present invention, and the engine speed according to the prior art.

According to the present invention, when the vehicle travels immediately after the cold / warm up and then shifts to the N range while stopped,
The idling speed gradually decreases according to the stop time. Therefore, sudden start at the time of D range shift at the time of restart can be prevented. The control of the idling rotational speed is performed by reducing the amount of air by controlling the ISC valve 20 or reducing the correction for increasing the warm-up of the fuel injection amount. By controlling in this manner, the vehicle can be started without stopping the engine even if the vehicle is started immediately after moving, and the idling speed gradually decreases even when shifting to the N range at the time of a temporary stop after traveling. Sudden start can be prevented.

[0014]

The present invention is an engine warm-up control device configured as described above. Therefore, if the engine is started when the idling speed immediately after the warm-up starts is increasing, the engine is stopped. The vehicle can be started smoothly without any delay, and then when shifting to the N range when the vehicle is temporarily stopped after traveling, the idling speed gradually decreases according to the stop time to prevent sudden start when starting. You can do it. Setting the range to the N range at the time of the primary stop means setting the range to the next D range or the N range for traveling. Therefore, by reducing the idling rotation speed in relation to the N range, it is possible to prevent sudden start according to the actual situation. Will be. Even during the temporary stop, the idling rotation does not decrease because the foot brake or the side brake is on in the D and R ranges.
Departure immediately after warm-up is performed carefully, but once driving, the driver often forgets to idle up and performs normal operations. Starting can be prevented.

[Brief description of the drawings]

FIG. 1 is a system diagram of one embodiment of the present invention.

FIG. 2 is a flowchart illustrating the operation of the apparatus of FIG.

FIG. 3 is a graph showing a relationship between a state of an engine and a vehicle and a fuel injection amount in the present invention and a conventional example.

FIG. 4 is a graph showing the relationship between the state of the engine and the vehicle and the engine speed in the present invention and the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 4 Throttle body 5 Throttle valve 6 Throttle positioner sensor 7 Idling passage 8 Injector 9 Fuel pump 15 Control unit 16 Water temperature sensor 17 Intake temperature sensor 18 Speed sensor 19 Shift sensor 20 ISC valve 21 Throttle opener VSV

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI F02D 41/08 325 F02D 41/08 325 45/00 312 45/00 312C (56) References JP-A-60-206945 (JP, A) JP-A-4-60145 (JP, A) JP-A-59-203838 (JP, A) JP-A-1-58328 (JP, U) JP-A 64-15740 (JP, U) JP-A-63 -190542 (JP, U) Fully open Showa 61-37444 (JP, U) Fully open Hei 3 -45442 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02D 29/00 B60K 41/28 F02D 41/06 325 F02D 41/08 325 F02D 45/00 312

Claims (1)

(57) [Claims] A cooling water temperature sensor for detecting a cooling water temperature of the engine; a rotation speed sensor for detecting a rotation speed of the engine;
A shift sensor that detects that the shift position of the transmission is in the N range and an output signal of each of these sensors detect and output that the vehicle is running while the engine is warming up and is temporarily stopped. An engine warm-up control device, comprising: a control unit that emits a signal; and a mechanism that receives an output signal of the control unit and reduces an idling speed.