JP4274658B2 - Engine idle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately cool an engine when the engine tends to be overheated. SOLUTION: After determining whether the temperature of cooling water is lower than 100 deg.C at S101, when the temperature of the cooling water is lower than 100 deg.C, the next step to proceed to is S102 where engine operation in idling is stopped by cutting fuel. When the temperature of the cooling water is 100 deg.C or more, the next step to proceed to is S103 where a cooling water temperature elevated alarm is operated and a water temperature alarm lamp 31 is lighted, followed by proceeding to S104. At S104, it is determined whether SOC of a main battery is left more than 80%, and when the SOC is left more than 80%, the next step to proceed to is S105 where a motor A2 is rotated to continue circulation of the cooling water of the engine 1 and ensure cooling of the engine 1. And when the SOC of the main battery is determined to be left 80% or less at S104, the next step to proceed to is S106 where the engine 1 is operated to perform normal idling rotation and continue the circulation of the cooling water of the engine 1 to ensure cooling thereof.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine idle control device that stops an engine according to driving conditions during idle driving of a vehicle.
[0002]
[Prior art]
2. Description of the Related Art In recent years, various technologies have been proposed and put into practical use for vehicles in order to stop an engine in accordance with driving conditions during idling from the viewpoint of environmental problems, improved fuel consumption, and quietness. .
[0003]
In order to perform such idle stop control, it is necessary to accurately determine whether or not the idle stop may be executed. For example, the condition of idle stop control of a hybrid vehicle including a generator / motor or a generator / running motor and an engine may be when power generation by idle driving of the engine is unnecessary or driving of a compressor of an air conditioner, etc. The engine power for the engine or the idle power by the motor used for engine rotation control and power generation is not required, or the engine or motor idle drive for the oil pump driving the hydraulic source for transmission control is not required There is a time, etc., and control is performed by judging these conditions.
[0004]
Further, in Japanese Patent Laid-Open No. 10-288063, when performing idling stop after running the vehicle, in order to obtain good exhaust purification performance, it is assumed that the catalyst temperature does not reach the active state when the catalyst temperature is equal to or lower than a predetermined temperature. A hybrid vehicle is prohibited.
[0005]
[Problems to be solved by the invention]
By the way, in the vehicle having the conventional idle stop control including the above prior art, when the coolant temperature of the engine becomes high and the vehicle is stopped due to an overheating tendency, the engine stops idling and the engine coolant is discharged. There is a possibility that the circulating water pump stops and the circulation of the cooling water is interrupted, so that the engine or the like may be defective due to insufficient cooling. For this reason, it is necessary to perform control so that the engine can be appropriately cooled during such an engine overheating tendency.
[0006]
The present invention has been made in view of the above circumstances, and an object thereof is to provide an engine idle control device capable of appropriately cooling an engine when the engine tends to overheat.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an engine idle control device according to the present invention according to claim 1 is provided with idle stop means for stopping engine operation during idling in accordance with the driving state of the vehicle, and serves as a motor or generator that also serves as a generator. in and idle control system for an engine equipped with traction motors, the idle stop means is greater than the value that the coolant temperature of the upper SL engine preset, when the battery remaining amount is less than the predetermined value, the idle stop Is prohibited, and the coolant is circulated by driving the engine. When the engine coolant temperature exceeds a preset value and the remaining battery level is greater than the predetermined value, the idle stop is permitted and the motor is driven. It is characterized by circulating cooling water .
[0012]
That is, the idle control device for an engine of the first aspect, a hybrid vehicle having an engine and a motor, the engine cooling water by circulating the engine driving force of the engine cooling water by the motor driving force circulation and is switched freely In the vehicle, when the coolant temperature of the engine exceeds a preset value, circulation of the coolant by the motor driving force and cooling water by the engine driving force according to the remaining amount of the battery that supplies power to the motor. Switch between circulation and continue efficient cooling.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a diagram for explaining the configuration of a hybrid vehicle drive control system, and FIG. 2 is a flowchart of an idle stop control routine. In the first embodiment, the present invention is applied to a hybrid vehicle as a vehicle.
[0014]
That is, as shown in FIG. 1, the hybrid vehicle in the present embodiment is a parallel hybrid vehicle that uses an engine and two motors A and B in combination, and is directly connected to the engine 1 and the output shaft 1 a of the engine 1. Motor A (motor / generator generator) 2 that is responsible for starting the engine 1 and generating power and assisting power, a single pinion planetary gear unit 3 connected to the output shaft 1a of the engine 1 extending from the motor A2, and the single Motor B (traveling motor) 4 that controls the functions of the pinion planetary gear unit 3 and serves as a driving force source for starting and reversing and recovering deceleration energy, and power conversion during traveling by shifting and torque amplification A drive system having a basic configuration of a continuously variable transmission 5 having a function is provided.
[0015]
Since the motor A2 is directly connected to the output shaft 1a of the engine 1, even if the engine 1 is stopped, the output shaft 1a of the engine 1 is rotated by the rotation of the motor A2, and the cooling water circulation (not shown) of the engine 1 is performed. The water pump can be driven.
[0016]
The planetary gear unit 3 includes a sun gear 3a, a carrier 3b that rotatably supports a pinion that meshes with the sun gear 3a, and a ring gear 3c that meshes with the pinion. The planetary gear unit 3 fastens and releases the sun gear 3a and the ring gear 3c. A lock-up clutch 6 is provided.
[0017]
The continuously variable transmission 5 is configured by winding a drive belt 5e between a primary pulley 5b pivotally supported by the input shaft 5a and a secondary pulley 5d pivotally supported by the output shaft 5c. Hereinafter, the continuously variable transmission 5 will be described as CVT5.
[0018]
In other words, in the hybrid vehicle drive system of the present embodiment, the planetary gear unit 3 having the lockup clutch 6 interposed between the sun gear 3a and the ring gear 3c is disposed between the output shaft 1a of the engine 1 and the input shaft 5a of the CVT 5. The sun gear 3a of the planetary gear unit 3 is coupled to the output shaft 1a of the engine 1 via the motor A2, the carrier 3b is coupled to the input shaft 5a of the CVT 5, and the motor B4 is coupled to the ring gear 3c. ing. A differential mechanism 8 is connected to the output shaft 5 c of the CVT 5 via a reduction gear train 7, and a front wheel or a rear wheel drive wheel 10 is connected to the differential mechanism 8 via a drive shaft 9.
[0019]
In this case, as described above, the engine 1 and the motor A2 are coupled to the sun gear 3a of the planetary gear unit 3, and the motor B4 is coupled to the ring gear 3c to obtain an output from the carrier 3b. Further, the output from the carrier 3b is output to the CVT 5 Therefore, the two motors A2 and B4 can be used for both power generation and driving force supply, and use relatively small output motors. be able to.
[0020]
Further, the sun gear 3a and the ring gear 3c of the planetary gear unit 3 are fastened by the lock-up clutch 6 according to the driving conditions, so that the two motors A2 and B4 are disposed between the engine 1 and the CVT 5 directly connected to the engine. A drive shaft can be formed, and the drive force can be efficiently transmitted to the CVT 5 or the braking force from the drive wheel 10 side can be used.
[0021]
Next, a control system (hybrid control system) that controls the above drive system and controls the traveling of the hybrid vehicle will be described. Reference numeral 15 is a control device that is composed of a microcomputer and a functional circuit controlled by the microcomputer, and centrally controls the engine 1, two motors A2, B4, and CVT5.
[0022]
The control device 15 detects the driver's driving status by detecting the depression of the accelerator pedal and the brake pedal, the steering angle of the steering, etc., and detects the operating status of auxiliary equipment such as lights and air conditioners. At the same time, a switch / sensor group is connected to detect the current vehicle running state such as vehicle speed, uphill and downhill, and road surface conditions. The control unit 15 further includes an engine 1, two motors A2, B4, CVT5 operating states, a main battery for the two motors A2, B4, and a 12V battery for normal auxiliary devices (both shown in the figure). (Not shown), and based on various information detected and monitored, control of the engine 1 to be described later, driving of motors A2 and B4 via an inverter (not shown) and charging control of each of the above batteries, Control gear ratio and supply hydraulic pressure. Also connected to the control device 15 are various meters for displaying the vehicle operating state such as the vehicle speed, engine speed, battery charging state, etc., and indicators such as warning lamps for warning the driver when an abnormality occurs. Has been.
[0023]
Further, the control device 15 judges each predetermined condition, and controls the ISC (idle speed control) valve or the throttle valve opening degree to control the engine 1 in idle control (normal idle control). Alternatively, the program shifts to an idle stop control program, which will be described later, and depending on the operation state of the vehicle, normal idle operation, idle stop for stopping engine operation during idle by fuel cut, engine 1 stops and motor A2 rotates. The idle operation by the motor A2 to be performed is selected and performed. That is, the control device 15 has a function as idle stop means.
[0024]
Specifically, the control device 15 obtains a 12V battery charge amount obtained from the terminal voltage of the 12V battery detected by the 12V battery voltage detector 21 and an accelerator pedal depression amount detected by the accelerator pedal sensor (APS) 22. The main battery remaining on the basis of the accelerator opening θ, the brake ON (brake pedal depression) / OFF (brake pedal release) by the brake switch 23, the output voltage of the main battery obtained by the SOC detector 24, the output current, and the battery temperature. Conditions such as the capacity (SOC), the vehicle speed V detected by the vehicle speed sensor 25, and the air conditioner ON (operation) / OFF (stop) from the air conditioner switch 26 are determined.
[0025]
This determination is made, for example, when the 12V battery charge amount is sufficient, the accelerator opening θ is 0, the brake is ON, the main battery SOC is 50% or more, the vehicle speed V is 0, and the air conditioner is OFF. When the process shifts to idle stop control and any one of the above conditions is not satisfied, normal idle control is executed.
[0026]
When each condition is satisfied and it is determined that the shift to the idle stop control is possible, the process is executed as shown in the flowchart of FIG. First, in step (hereinafter abbreviated as “S”) 101, it is determined whether or not the cooling water temperature is lower than a value (for example, 100 ° C.) set in advance by determining that the cooling water temperature tends to overheat by experiments or the like. When the temperature is lower than 100 ° C., the process proceeds to S102, and the normal idling stop, that is, the engine operation during idling is stopped by fuel cut.
[0027]
When it is determined in S101 that the cooling water temperature is 100 ° C. or higher, the cooling water is hot and the engine 1 tends to overheat. Therefore, the process proceeds to S103, the cooling water temperature high temperature alarm is activated and the water temperature warning lamp 31 is Turns on and proceeds to S104.
[0028]
In S104, it is determined whether or not the SOC of the main battery remains more than a predetermined value (for example, 80%) that is determined to be sufficient as the remaining amount. If more than 80% remains, the process proceeds to S105. The water pump for circulating the cooling water is driven to rotate the motor A2 at a rotation speed capable of ensuring the cooling of the engine 1, and the engine operation is stopped by fuel cut to improve fuel consumption. In S104, if the SOC of the main battery is 80% or less, the process proceeds to S106, and the engine 1 is operated to perform normal idle rotation.
[0029]
That is, since the operation of the engine 1 in the idle region is not efficient, if the SOC of the main battery is sufficient, the engine 1 is stopped and the motor A2 is rotated to efficiently circulate the coolant of the engine 1. The water pump is driven to cool the engine 1.
[0030]
Thus, according to the first embodiment, in a hybrid vehicle equipped with an engine and a motor, when the cooling water temperature of the engine 1 exceeds a preset value, engine operation or motor rotation Therefore, the cooling water circulation of the engine 1 is continued and the cooling of the engine 1 is continued. Therefore, when the engine 1 becomes high temperature and tends to overheat, the engine can be appropriately cooled. Yes.
[0031]
In addition, when the engine 1 becomes hot and tends to overheat, the cooling water circulation of the engine 1 is performed by stopping the engine 1 and rotating the motor A2 if the SOC of the main battery is sufficient. The engine 1 can be cooled by driving the water pump for circulating the cooling water of the engine 1 efficiently.
[0032]
Next, FIG. 3 is a flowchart of an idle stop control routine according to a reference example of the present invention. This reference example is an example of a vehicle having an engine as a main drive source other than the hybrid vehicle as in the first embodiment. For this reason, the configuration of the vehicle has no components related to the motor and the main battery, and the components that are the same as those in the first embodiment will be described with the same reference numerals.
[0033]
The idle stop control is executed as shown in the flowchart of FIG. First, in S201, it is determined whether or not the cooling water temperature of the engine 1 is lower than a preset value (for example, 100 ° C.). If the cooling water temperature is lower than 100 ° C., the process proceeds to S202, and normal idling is stopped. That is, the engine operation during idling is stopped by fuel cut.
[0034]
Further, when it is determined in S201 that the cooling water temperature is 100 ° C. or higher, the cooling water of the engine 1 is high temperature and the engine 1 tends to overheat. Therefore, the process proceeds to S203, and the cooling water temperature high temperature alarm is activated. The lamp 31 is turned on, and the process proceeds to S204, where the engine 1 is operated to perform normal idle rotation, the water pump for circulating the cooling water of the engine 1 is driven, and cooling of the engine 1 is ensured.
[0035]
【The invention's effect】
As described above, according to the first aspect of the present invention, the vehicle is equipped with a motor that also serves as a generator or a generator and a traveling motor and an engine. When the engine cooling water circulation by driving force is switchable, when stopping the engine operation during idling, if the engine cooling water temperature exceeds a preset value, the motor battery By switching between the cooling water circulation by the motor driving force and the cooling water circulation by the engine driving force according to the remaining amount, the cooling water circulation at idle at a high engine temperature can be performed more efficiently and It is possible to improve fuel efficiency by expanding the stop area .
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the configuration of a drive control system for a hybrid vehicle according to a first embodiment of the invention. FIG. 2 is a flowchart of an idle stop control routine. FIG. 3 is an idle stop control according to a reference example of the invention. Routine flowchart [Explanation of symbols]
1 Engine 2 Motor A
4 Motor B
5 CVT
15 Control device (idle stop means)
21 12V battery voltage detector 22 APS
23 Brake switch 24 SOC detector 25 Vehicle speed sensor 26 Air conditioner switch 27 Cooling water temperature sensor 31 Water temperature warning lamp

Claims (1)

In an idle control device for an engine equipped with an idle stop means for stopping engine operation during idling according to the driving state of the vehicle, and mounted together with a generator-cum-use motor or a generator and a traveling motor ,
The idle stop means is greater than the value of the cooling water temperature preset upper SL engine, if the remaining battery capacity is below a predetermined value, prohibits idle stop, the circulation of the coolant by the engine drive, When the engine cooling water temperature exceeds a preset value and the remaining battery level is greater than a predetermined value, idling stop is permitted and cooling water is circulated by driving the motor. Control device.

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