JP-7856044-B2 - Hybrid vehicles

Inventors

• 松本 宝

Assignees

• 株式会社豊田自動織機

Dates

Publication Date

20260511

Application Date

20230428

Claims (2)

1. A hybrid vehicle having an internal combustion engine and a motor generator, The exhaust path of the aforementioned internal combustion engine is equipped with a catalyst that purifies NOx contained in the exhaust gas. The system includes a control device that controls the internal combustion engine and the motor generator, The control device is A user-requested torque calculation unit determines the user-requested torque based on the operating state of the internal combustion engine and the amount the accelerator pedal is depressed, A target warm-up torque calculation unit determines the target warm-up torque based on the aforementioned operating conditions, When catalyst warm-up conditions requiring the warm-up of the catalyst are met, and the target warm-up torque is greater than the user-requested torque, the catalyst warm-up processing unit controls the internal combustion engine to output the target warm-up torque, and controls the motor generator to consume the surplus torque obtained by subtracting the user-requested torque from the target warm-up torque for power generation. It has, The aforementioned target warm-up torque is, Based on the NOx emission characteristics, which are the characteristics of NOx emissions corresponding to the operating state and the internal combustion engine torque, and the exhaust heat quantity characteristics, which are the characteristics of exhaust heat quantity corresponding to the operating state and the internal combustion engine torque, In accordance with each driving state, a first target torque is set such that, among torques greater than or equal to the driving torque required for the hybrid vehicle to run in that driving state, the value of the exhaust heat amount / NOx emissions for that driving state is approximately the maximum value. Hybrid vehicle.
2. A hybrid vehicle according to claim 1, The control device stores, based on the operating state, an integrated NOx emission value obtained by accumulating NOx emissions and an integrated mileage value obtained by accumulating the mileage of the hybrid vehicle. As the aforementioned target warm-up torque, The above-mentioned first target torque and, Based on the NOx emission characteristics, a second target torque is set corresponding to each operating state, such that among torques greater than or equal to the aforementioned driving torque for that operating state, the value of the NOx emission for that operating state is approximately the minimum value. It is set, The control device is When the target warm-up torque is determined by the target warm-up torque calculation unit, If the NOx emission value / mileage value is less than or equal to a predetermined threshold, the first target torque is determined as the target warm-up torque. If the NOx emission value / mileage value is greater than a predetermined threshold, the second target torque is determined as the target warm-up torque. Hybrid vehicle.

Description

This invention relates to a hybrid vehicle having an internal combustion engine and a motor generator. Conventionally, in hybrid vehicles having an internal combustion engine and a motor-generator (having the functions of both an electric motor and a generator), for example, Patent Document 1 discloses a control device for a hybrid vehicle that can improve fuel efficiency by suppressing the number of times the internal combustion engine is started while ensuring catalyst warm-up. The control device for a hybrid vehicle described in Patent Document 1 comprises: a road information acquisition unit for acquiring road information; a speed prediction unit for predicting the driving speed along the planned route based on the road information; an engine operation prediction unit for predicting the engine operating state along the planned route based on the predicted driving speed; a catalyst temperature prediction unit for predicting the catalyst temperature along the planned route based on the predicted driving speed; and an engine control unit that, when it is predicted that the catalyst temperature will fall below a lower limit temperature while the engine is stopped, changes the engine operating conditions during the engine operation prior to that point to a higher load than the normal operating conditions. Furthermore, the control device for the hybrid vehicle described in Patent Document 1 sets the total increased load when changing the engine operating conditions to a higher load than normal operating conditions, based on the predicted value (energy) of the catalyst temperature drop during the engine stop period, which includes the period when the predicted catalyst temperature is expected to fall below the lower limit temperature. It is then set based on the predicted average driving speed during the engine stop period when the catalyst temperature is expected to fall below the lower limit temperature, and the length of that engine stop period. Japanese Patent Publication No. 2016-008517 This is a schematic diagram of the hybrid vehicle according to the present invention.Figure 1 is a schematic diagram of the internal combustion engine system installed in the hybrid vehicle shown.This figure illustrates an example of a user-requested torque characteristic, showing the relationship between the accelerator pedal depression amount, the internal combustion engine speed (N1 to N5), and the user-requested torque.This diagram illustrates an example of NOx emission characteristics, showing NOx emissions in relation to the operating conditions of an internal combustion engine (in this example, engine speed) and the torque of the internal combustion engine.This diagram illustrates an example of exhaust heat quantity characteristics, showing the amount of exhaust heat quantity corresponding to the operating state of the internal combustion engine (in this example, the engine speed) and the torque of the internal combustion engine.This figure illustrates the exhaust heat quantity/NOx emission characteristics created based on the NOx emission characteristics shown in Figure 4 and the exhaust heat quantity characteristics shown in Figure 5, as well as an example of g(x), which is approximately the maximum exhaust heat quantity/NOx emission value for each driving condition (in this example, each internal combustion engine speed) within the range of driving torque.This figure illustrates an example of the target warm-up torque characteristic (1), which was created based on the exhaust heat quantity/NOx emission characteristics and g(x) shown in Figure 6.This is a flowchart illustrating an example of the processing procedure of the control device in the first embodiment.Figure 4 illustrates the NOx emission characteristics and provides examples of h(x), which represents the value of the NOx emission that is approximately the minimum for each operating condition (in this example, each internal combustion engine speed) within the range of driving torque.This figure illustrates an example of the target warm-up torque characteristic (2), which was created based on the NOx emission characteristics and h(x) shown in Figure 9.This is a flowchart illustrating an example of the processing procedure of the control device in the second embodiment. Embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the description refer to the same elements having the same function, without redundant description. The control device 40 of the hybrid vehicle according to this embodiment is applied to the hybrid vehicle 1 shown in Figure 1. The hybrid vehicle 1 includes an internal combustion engine 2, a motor generator 3, the control device 40, front wheels 11a-11b, rear wheels 12a-12b, clutches 13a-13b, a transmission 14, a differential gear 15, a transmission shaft 16, a propeller shaft 17, a drive shaft 18, an inverter 31, and a battery 32. <Configuration of Hybrid Vehicle 1 (Figure 1