JP2015033971A - Hybrid system, hybrid vehicle, and power transmission method of hybrid system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid system, a hybrid vehicle, and a power transmission method of hybrid system capable of maintaining catalyst temperature of an exhaust emission control system and water temperature of coolant in a proper range easily while maintaining efficiency of electric characteristic of a motor generator.SOLUTION: When power transmission between a crank shaft and a motor generator is performed via a CVT directly coupled to the crank shaft, based on at least one of water temperature t1, and catalyst temperature t2, load Q of an engine is set. Then second torque is changed while limiting rotation speed of the motor generator in a high efficiency rotation area so that total torque T of first torque outputted from the engine having the load Q and the second torque outputted from the motor generator via the CVT reaches to requirement torque T' required for travel of a hybrid vehicle 1.

Description

  The present invention relates to a hybrid system, a hybrid vehicle, and a power transmission method of the hybrid system. More specifically, the present invention relates to a hybrid system and a hybrid vehicle that can maintain the coolant temperature and the catalyst temperature of the exhaust gas purifying device within an appropriate range. And a power transmission method of a hybrid system.

  In a hybrid vehicle (HEV) equipped with both an internal combustion engine and a motor generator, the motor generator is driven by the output of the internal combustion engine to generate power, and the generated power is charged into a battery or charged into this battery. The motor generator is driven by electric power to assist the output of the internal combustion engine. When driving a motor generator with this internal combustion engine, it is necessary to transmit the driving force of the internal combustion engine to the motor generator.

  In such a hybrid vehicle, the temperature of the cooling water for cooling the internal combustion engine and the catalyst temperature of the catalyst provided in the exhaust gas purification device in the exhaust passage of the internal combustion engine vary depending on the load of the internal combustion engine, and the load of the internal combustion engine is reduced. Adjustment is possible by increasing or decreasing. The shortage due to the increase or decrease in the load on the internal combustion engine is compensated by the motor generator.

  In this regard, there is a device in which the torque output from the internal combustion engine is lowered until the coolant temperature changes from high water temperature to low water temperature, and the shortage caused thereby is compensated by the torque output from the traveling motor generator (motor generator). It has been proposed (see, for example, Patent Document 1). There has also been proposed an apparatus for increasing the load on an internal combustion engine by generating power with a motor (motor generator) when the catalyst temperature of the catalyst is low (see, for example, Patent Document 2).

  However, in the devices described in Patent Document 1 and Patent Document 2, it is necessary to control the output of the motor generator, and there is a problem that the control becomes complicated. In addition, by controlling the output of the motor generator, the motor generator speed may deviate from the rotation region where the power generation efficiency or the drive efficiency is high, resulting in a large energy loss in the motor generator and a deterioration in fuel consumption. There is a problem. On the other hand, there is a problem in that the required output is insufficient when the rotational speed of the motor generator is attempted to fall within a rotation region where the power generation efficiency or drive efficiency is high.

JP 2007-238039 A JP2012-031742A

  The present invention has been made in view of the above problems, and the problem is that the water temperature of the cooling water and the catalyst temperature of the exhaust gas purification device can be maintained while maintaining the efficiency of the electric characteristics of the motor generator. To provide a hybrid system, a hybrid vehicle, and a power transmission method of the hybrid system that can be easily maintained in an appropriate range.

A hybrid system of the present invention for solving the above-described problems is a hybrid system having an internal combustion engine and a motor generator, and is not directly connected to a crankshaft of the internal combustion engine in the hybrid system having an internal combustion engine and a motor generator. A step-speed transmission mechanism, the motor generator connected to the continuously variable transmission mechanism, a temperature of cooling water for cooling the internal combustion engine, and a catalyst catalyst provided in an exhaust gas purification device in an exhaust passage of the internal combustion engine From the load setting means for setting the load of the internal combustion engine based on at least one of the temperatures, the first torque output from the internal combustion engine corresponding to the load set by the load setting means, and the motor generator The second torque is changed so that the combined torque with the second torque output via the continuously variable transmission mechanism becomes a required torque required for vehicle travel. Constituted a control device is provided with a torque change means for.

  Note that the first torque output by the internal combustion engine here is zero (neutral inertia traveling, etc.) or negative (engine brake is not effective) when the internal combustion engine is coasting when the direction in which the drive wheels are driven is plus. It also includes the value of inertial running, etc. On the other hand, the second torque output from the motor generator via the continuously variable transmission mechanism is a positive value when the motor generator is driven by power running, and a negative value when the motor generator is driven regeneratively.

  According to this configuration, since the second torque output from the motor generator via the continuously variable transmission mechanism is changed, the load is set based on the coolant temperature or the catalyst temperature of the catalyst of the exhaust gas purification device. The difference between the first torque output from the internal combustion engine and the required torque required for traveling of the vehicle can be compensated.

  This reduces the second torque so that the combined torque does not become excessive with respect to the required torque when the load of the internal combustion engine is increased at low water temperature or low catalyst temperature. In the case of the water temperature or the high catalyst temperature, the second torque can be increased so that the total torque does not become insufficient with respect to the required torque when the load of the internal combustion engine is reduced.

  As a result, the combined torque satisfies the required torque, maintaining the cooling water and catalyst temperatures in an appropriate range without degrading the operability, thereby reducing fuel consumption by reducing exhaust gas and internal combustion engine loss. Can be obtained.

  In addition, a continuously variable transmission such as a belt-type CVT can be used as a variable ratio mechanism capable of continuously changing the rotation speed ratio between the internal combustion engine and the motor generator, for example, through a continuously variable transmission mechanism for power transmission of the motor generator. Since the power of the crankshaft of the internal combustion engine is transmitted to the motor generator using the mechanism, the rotation speed of the rotation shaft of the motor generator can be determined without depending on the fluctuation of the rotation speed of the crankshaft of the internal combustion engine. It is possible to control so as to be limited to a high-efficiency rotation region having high electrical characteristics suitable for power generation or driving.

  Therefore, by limiting the rotation speed range of the motor generator, the motor generator can be used in a state where the efficiency of the electrical characteristics is high, and the energy efficiency during power generation and electric drive is increased. be able to. Further, it is not necessary to employ an excessively structured bearing structure and a high-strength structure necessary for ensuring reliability so that the motor generator can be used at an excessive number of revolutions. As a result, the motor generator and the hybrid system can be reduced in size and weight.

  In the hybrid system, the torque changing means may be configured to change the second torque while limiting the rotational speed of the motor generator to a predetermined high-efficiency rotation region. In addition to the above effect, the second torque output from the motor generator via the continuously variable transmission mechanism can be changed so as not to reduce the efficiency of the electric characteristics of the motor generator. Thereby, in addition to the reduction of exhaust gas and the loss of the internal combustion engine, the effect of improving the fuel consumption by the reduction of the loss of the motor generator can be obtained.

  In addition, in the above hybrid system, when the torque changing means is provided with a speed ratio changing means for changing the second torque by changing a speed ratio of the continuously variable transmission mechanism, a continuously variable transmission is provided. By changing the gear ratio of the mechanism, the distribution of the first torque and the second torque can be easily changed without reducing the efficiency of the electric characteristics of the motor generator.

  In addition, in the above hybrid system, when the torque changing means is provided with output torque changing means for changing the second torque by changing the output torque of the motor generator, By changing the output torque, the excess or deficiency due to the first torque is output from the motor generator via the continuously variable transmission mechanism without reducing the efficiency of the electrical characteristics of the motor generator. It can be easily compensated with 2 torques.

  And the hybrid vehicle of this invention for solving said subject is mounted and comprised by said hybrid system. According to this configuration, it is possible to provide a hybrid vehicle capable of reducing the exhaust gas and improving the fuel consumption by reducing the loss by maintaining the temperature of the cooling water of the internal combustion engine and the catalyst of the exhaust gas purification device optimally. Can do.

  And the power transmission method of the hybrid system of the present invention for solving the above-mentioned problems is a power transmission method of a hybrid system having an internal combustion engine and a motor generator, wherein a continuously variable transmission mechanism directly connected to the crankshaft of the internal combustion engine is used. When the power is transmitted between the crankshaft and the motor generator, the temperature of the cooling water for cooling the internal combustion engine and the catalyst provided in the exhaust gas purification device of the exhaust passage of the internal combustion engine A load of the internal combustion engine is set based on at least one of the catalyst temperatures, and is output from the motor generator corresponding to the load and the motor generator via the continuously variable transmission mechanism. In this method, the second torque is changed so that the combined torque with the second torque becomes a required torque required for traveling of the vehicle.

  In the above power transmission method of the hybrid system, the rotational speed of the motor generator is limited to a predetermined high-efficiency rotation region so that the combined torque becomes a required torque necessary for traveling of the vehicle. It is desirable to change the second torque.

  According to this method, when power is transmitted between the crankshaft and the motor generator via the continuously variable transmission mechanism, the cooling water temperature is reduced without reducing the efficiency of the electric characteristics of the motor generator. The second torque output from the motor generator can compensate for the excess or deficiency with respect to the required torque of the first torque output from the internal combustion engine under load based on the catalyst temperature of the catalyst. As a result, the water temperature and the catalyst temperature can be optimally maintained while satisfying the required torque required for traveling of the vehicle.

  According to the hybrid system, the hybrid vehicle, and the power transmission method of the hybrid system of the present invention, the first output from the motor generator via the continuously variable transmission mechanism so as not to reduce the efficiency of the electric characteristics of the motor generator. Since the two torques are changed, the difference between the first torque output from the internal combustion engine of the load set based on the coolant temperature and the catalyst temperature of the catalyst of the exhaust gas purification device and the required torque required for traveling of the vehicle is calculated. Can be supplemented.

  As a result, the motor generator can be driven with high efficiency without reducing the regenerative efficiency and drive efficiency, and the combined torque of the first torque and the second torque satisfies the required torque without reducing the drivability. In addition, by maintaining the temperature of the cooling water and the catalyst within an appropriate range, it is possible to obtain effects such as reduction of exhaust gas and improvement of fuel efficiency due to reduction of loss of the internal combustion engine and motor generator.

It is a figure showing composition of a hybrid system and a hybrid vehicle of a 1st embodiment concerning the present invention. It is a flowchart which shows the power transmission method of the hybrid system of 1st Embodiment which concerns on this invention. It is a figure which shows the structure of the hybrid system and hybrid vehicle of 2nd Embodiment which concern on this invention. It is a flowchart which shows the other example of the power transmission method of the hybrid system of 2nd Embodiment which concerns on this invention.

  The hybrid system, hybrid vehicle, and hybrid system power transmission method according to the first and second embodiments of the present invention will be described below.

  As shown in FIG. 1, the hybrid system 2 of the first embodiment is a hybrid system having an engine (internal combustion engine) 10 and a motor generator (M / G) 21. Here, although this hybrid system 2 is described as being mounted on a hybrid vehicle (HEV: hereinafter referred to as a vehicle) 1, it is not necessarily limited to that mounted on the vehicle.

  As shown in FIG. 1, the engine 10 of the hybrid system 2 includes an engine body (ENG) 11, an exhaust passage 12, a turbocharger 13, and an exhaust gas purification device (post-treatment device) 14 provided in the exhaust passage 12. It has. The exhaust gas purification device 14 purifies NOx (nitrogen oxide), PM (particulate matter), etc. in the exhaust gas discharged from the engine 10. The purified exhaust gas is released into the atmosphere via a muffler (not shown) or the like.

  A CVT (continuously variable transmission mechanism: ratio variable mechanism) 16 is provided directly connected to the crankshaft 15 of the engine 10, and a motor generator 21 is connected to the CVT 16. In other words, the first pulley 16a of the CVT 16 is provided on the crankshaft 15 of the engine 10 and the second pulley 16b of the CVT 16 is provided on the motor generator 21, and the crankshaft is interposed via the first pulley 16a and the second pulley 16b. 15 and the motor generator 21 are configured to transmit power.

  An endless belt or chain (power transmission member) 16c is hung between the first pulley 16a and the second pulley 16b. From the crankshaft 15, the first pulley 16a, the power transmission member 16c, and the second pulley. Power is transmitted to the motor generator 21 via 16b, and conversely to the crankshaft 15 from the motor generator 21 via the second pulley 16b, the power transmission member 16c and the first pulley 16a.

  In this CVT 16, a pair of first pulley 16a and second pulley 16b is provided with a V-shaped power transmission member 16c, and the widths of the individual pulleys 16a and 16b are changed to thereby transmit power to the pulleys 16a and 16b. The position where the member 16c comes into contact is changed, and the diameter of the position where the power transmission member 16c comes into contact is reduced when it is inward, and conversely, it is increased when it is outside. And, by controlling the width of the two pulleys 16a and 16b to be opposite to each other by hydraulic or electric mechanism (not shown) by electronic control, the power transmission member 16c is not slackened. Shifting can be performed continuously.

When the CVT 16 is configured such that the transmission 31 is connected to one of the crankshafts 15 and the CVT 16 is connected to the other of the crankshafts 15 in the engine 10, the CVT 16 is connected to the transmission 31 with respect to the engine 10. Is provided on the crankshaft 15 on the opposite side. Thereby, it is not necessary to provide the CVT 16 between the engine 10 and the transmission 31. For this reason, motor generators can be easily installed even for combinations of existing engines and transmissions (powertrains) that do not consider hybrid systems, and the types of powertrains that can be equipped with hybrid systems have been expanded. Can be easily done.

  In this case, in the prior art, on the opposite side of the transmission with respect to the engine, an auxiliary machine such as a cooling fan, a cooling water pump, or a lubricating oil pump that obtains driving force from the crankshaft is arranged. These auxiliary machines are preferably electrified so as to be driven by the electric power generated by the motor generator without obtaining the driving force directly from the crankshaft. This increases the freedom with respect to the layout of the auxiliary machinery, and further has the advantage that the engine output without load loss due to the auxiliary machinery can be used as the driving force depending on the situation.

  The motor generator 21 that is a part of the power system 20 generates power by receiving the driving force of the engine 10 as a generator, or generates regenerative power by generating regenerative power such as the braking force of the vehicle 1. Or as a motor, the driving force is transmitted to the crankshaft 15 of the engine 10 to assist the driving force of the engine 10.

  The electric power generated by the power generation is converted by the inverter (INV) 23 via the wiring 22 and charged in the first battery (charger: B1) 24A. When driving the motor generator 21, the electric power charged in the first battery 24 </ b> A is converted by the inverter 23 and supplied to the motor generator 21.

  In the configuration of FIG. 1, a DC-DC converter (CON) 25 and a second battery (B2) 24B are further provided in series with the first battery 24A. In the DC-DC converter 25, for example, the voltage is dropped to 12 V and charged to the second battery 24B, and the auxiliary battery cooling fan 26A, cooling water pump 26B, Electric power is supplied to the lubricating oil pump 26C and the like.

  In a hybrid vehicle (hereinafter referred to as a vehicle) 1 equipped with the hybrid system 2, the power of the engine 10 is transmitted to a transmission 31 of the power transmission system 30, and further, a propulsion shaft (propeller shaft) is transmitted from the transmission 31. It is transmitted to the operating device (differential gear) 33 through 32, and transmitted to the wheel 35 from the operating device 33 through the drive shaft (drive shaft) 34. Thereby, the motive power of the engine 10 is transmitted to the wheel 35 and the vehicle 1 travels.

  On the other hand, regarding the power of the motor generator 21, the power charged in the first battery 24A is supplied to the motor generator 21 via the inverter 23, and the motor generator 21 is driven by this power to generate power. The power of the motor generator 21 is transmitted to the crankshaft 15 via the CVT 16, transmitted through the power transmission path of the engine 10, and transmitted to the wheels 35.

  Thereby, the power of the motor generator 21 is transmitted to the wheels 35 together with the power of the engine 10, and the vehicle 1 travels. During regeneration, the regenerative power of the wheels 35 or the regenerative power of the engine 10 is transmitted to the motor generator 21 through the reverse path, and the motor generator 21 can generate power.

Also, a hybrid system control device 41 is provided, and the operating state such as the rotational speed Ne and load Q of the engine 10 and the operating state such as the rotational speed Nm of the motor generator 21 and the charging of the first battery 24A and the second battery 24B. While monitoring the quantity (SOC) state, the CVT 16, the motor generator 21, the inverter 23, the DC-DC converter 25, and the like are controlled. The hybrid system control device 41 is usually an overall control device 40 that controls the engine 10 and the vehicle 1.
Built in. The overall control device 40 controls the combustion in the cylinder, the turbocharger 13, the exhaust gas purification device 14, the cooling fan 26A of the auxiliary machine, the cooling water pump 26B, the lubricating oil pump 26C and the like in the control of the engine 10. Yes.

  The hybrid system 2 according to this embodiment does not reduce the efficiency of the electric characteristics of the motor generator 21, and the cooling water temperature t1 of the engine 10 and the catalyst temperature of the catalyst provided in the exhaust gas purification device 14. In order to maintain t2, a water temperature sensor 42 is provided as a water temperature detecting means for detecting the water temperature t1, and a catalyst temperature sensor 43 is provided as a catalyst temperature detecting means for detecting the catalyst temperature t2, and the overall control device 40 is provided with a load setting means M1. And the hybrid system control device 41 includes the torque changing means M2.

  The load setting means M1 is a means for setting the load Q of the engine 10, and based on at least one of the water temperature t1 and the catalyst temperature t2, the load Q of the engine 10 can be reduced to reduce the water temperature t1 or the catalyst temperature t2. It is means for setting the load QL, the high load QH that can raise the water temperature t1 and the catalyst temperature t2, and the like.

  Specifically, the load setting means M1 determines the fuel injection amount of the engine 10 when the water temperature t1 is higher than the predetermined optimum water temperature range Δt1 or when the catalyst temperature t2 is higher than the predetermined optimum catalyst temperature range Δt2. The load Q of the engine 10 is lowered to the low load QL by controlling to reduce the intake air supply amount. On the other hand, when the water temperature t1 is lower than the predetermined optimum water temperature range Δt1, or when the catalyst temperature t2 is lower than the predetermined optimum catalyst temperature range Δt2, the fuel injection amount and the intake air supply amount of the engine 10 are increased. To increase the load Q of the engine 10 to the high load QH. As a result, the water temperature t1 and the catalyst temperature t2 can be maintained at optimum temperatures.

  The torque changing means M2 is a first torque T1 output from the engine 10 with respect to a required torque T ′ required for traveling the hybrid vehicle 1, and a second torque T2 output from the motor generator 21 via the CVT 16. This is means for changing the second torque T2 so that the combined torque T does not become excessive or insufficient. The torque changing means M2 is also means for changing the second torque T2 while limiting the rotational speed Nm of the motor generator 21 to a predetermined high-efficiency rotational region.

  Accordingly, the second torque T2 output from the motor generator 21 via the CVT 16 can be changed so as not to reduce the efficiency of the electrical characteristics of the motor generator 21.

  Specifically, the torque changing means M2 is provided with a gear ratio changing means M3, and the gear ratio changing means M3 limits the rotational speed Nm of the motor generator 21 to a predetermined high-efficiency rotation region, and the motor generator 21 is a means for changing the pulley ratio (transmission ratio) R of the CVT 16 so as to change the second torque T2 output by the engine 21.

  The high-efficiency rotation region is a rotation region optimized based on the regenerative efficiency and drive efficiency of the motor generator 21 so that the efficiency of their electrical characteristics is high. This is a rotation region determined by characteristics such as horsepower.

  The gear ratio changing means M3 first sets a target rotational speed Nm ′ within a high-efficiency rotational area that is stored in advance in the hybrid system control device 41. Next, the engine speed Ne is detected from a speed sensor such as a crank angle sensor as an internal combustion engine speed detection means. Next, on the basis of the engine speed Ne and the target speed Nm ′, a pulley ratio control map stored in advance in the hybrid system control device 41 is referred to, and an actuator (not shown) provided in the CVT 16 is used to The width of each of the second pulleys 16b is expanded and contracted, the diameter of each pulley is changed, and the pulley ratio R is changed.

  In particular, the speed change means M3 is configured to reduce the rotational speed Nm of the motor generator 21 to a high-efficiency rotational region even when the load Q of the engine 10 is a high load QH and the rotational speed Ne is in a high rotational region. Therefore, it is possible to prevent the rotation speed Nm of the motor generator 21 from becoming a high rotation speed with low efficiency of electrical characteristics, and to avoid an increase in energy loss of the motor generator 21. be able to.

  The gear ratio changing means M3 includes a first torque T1 output from the engine 10 of the load Q set by the load setting means M1 and a second torque T2 output from the motor generator 21 via the CVT 16. The second torque T2 is changed while limiting the rotational speed Nm of the motor generator 21 to the high-efficiency rotational region as described above so that the combined torque T becomes the required torque T ′ required for the traveling of the hybrid vehicle 1. It is also a means to make it.

  That is, the gear ratio changing means M3 which is also the torque changing means M2 changes the distribution of the second torque T2 by changing the pulley ratio R of the CVT 16, so that the first torque T1 and the combined torque T are the required torque T ′. Can be compensated not to become excessive or insufficient.

  For example, a case where the required torque T ′ does not change will be described as an example. When the water temperature t1 is higher than the optimum water temperature range Δt1 or when the catalyst temperature t2 is higher than the optimum catalyst temperature range Δt2, the load Q of the engine 10 is set to the low load QL by the load setting means M1. The first torque T1 decreases. The pulley ratio R of the CVT 16 is changed so that the decreased amount is compensated by the second torque T2. On the other hand, when the water temperature t1 is lower than the optimum water temperature range Δt1 or when the catalyst temperature t2 is lower than the optimum catalyst temperature range Δt2, the load Q of the engine 10 is set to the high load QH by the load setting means M1. Accordingly, the first torque T1 increases. The pulley ratio R of the CVT 16 is changed so that the increased amount is compensated by the second torque T2.

  And the power transmission method of the hybrid system 2 in this 1st Embodiment is the water temperature when performing the power transmission between the crankshaft 15 and the motor generator 21 via CVT16 directly connected to the crankshaft 15. The load Q of the engine 10 is set based on at least one of t1 and the catalyst temperature t2, and the first torque T1 output from the engine 10 of the load Q and the first output from the motor generator 21 via the CVT 16 are set. The second torque T2 is set while limiting the rotation speed Nm of the motor generator 21 to a predetermined high-efficiency rotation region so that the combined torque T of the two torques T2 becomes the required torque T necessary for the traveling of the hybrid vehicle 1. It is a method characterized by changing.

  An example of this power transmission method will be described with reference to the flowchart of FIG. Note that the power transmission method described below will be described by taking as an example a state in which the required torque T ′ necessary for running the hybrid vehicle is not changed during the operation of the engine 10.

  First, step S10 in which the water temperature sensor 42 detects the coolant temperature t1 is performed. Next, step S20 in which the catalyst temperature sensor 43 detects the catalyst temperature t2 of the catalyst is performed.

  Next, the load setting means M1 is implemented, and step S30 for determining whether the water temperature t1 is within the optimum water temperature range Δt1 is performed. Next, step S40 for determining whether or not the catalyst temperature t2 is within the optimum catalyst temperature range Δt2 is performed. If it is determined in steps S30 and S40 that both the water temperature t1 and the catalyst temperature t2 are optimum temperatures, the power transmission method ends. On the other hand, if it is determined in step S30 and step S40 that at least one of the water temperature t1 and the catalyst temperature t2 is not the optimum temperature, next, step S50 for setting the load Q of the engine 10 is performed. In step S50, the load Q of the engine 10 is set to a high load QH if the water temperature t1 or the catalyst temperature t2 is lower than the optimum temperature, and to a low load QL if the water temperature t1 or the catalyst temperature t2 is higher than the optimum temperature. To do.

  Next, the torque changing means M2 is implemented, and step S60 for calculating the total torque T of the first torque output from the engine 10 and the second torque T2 output from the motor generator 21 is performed. Next, step S70 for calculating the excess or deficiency of the required torque T 'and the combined torque T necessary for running the hybrid vehicle 1 is performed.

  Next, the gear ratio changing means M3 is implemented to change the pulley ratio R of the CVT 16 so as to compensate for the excess and deficiency calculated in step S70 and to limit the rotation speed Nm of the motor generator 21 to the high efficiency rotation region. Step S80 is performed. Next, it returns to step S10 again, and step S10-step S80 are performed so that the temperature of water temperature t1 and catalyst temperature t2 may become the optimal temperature.

  The power transmission method is configured not to determine the catalyst temperature t2 if the water temperature t1 is outside the appropriate temperature. That is, this is a method of controlling the water temperature t1 with priority. The present invention is not limited to this, and is configured to determine the catalyst temperature t2 even when the water temperature t1 is outside the proper temperature, and a method of controlling so that the water temperature t1 and the catalyst temperature t2 are always within the proper temperature. It is desirable to do.

  Next, a power transmission method of the hybrid system 2A, the hybrid vehicle 1A, and the hybrid system 2A according to the second embodiment of the present invention will be described with reference to FIG. This hybrid system 2A includes a crankshaft clutch 17 that connects and disconnects transmission of power between the crankshaft 15 and the motor generator 21 between the crankshaft 15 and the first pulley 16a in addition to the configuration of FIG. Is provided.

  The crankshaft clutch 17 is controlled by a hybrid system controller 41. The crankshaft clutch 17 is brought into a contact state when the motor generator 21 is generated by the power of the crankshaft 15 of the engine 10 or when the driving force of the engine 10 is assisted by the driving force of the motor generator 21. The power is transmitted between the crankshaft 15 and the motor generator 21.

  The hybrid system control device 41A includes torque changing means M2A, and the torque changing means M2A includes output torque changing means M4 and connecting / disconnecting means M5.

  The output torque changing means M4 is a means for increasing or decreasing the output torque Tm of the motor generator 21 so as to change the second torque T2. Specifically, the rotation speed Nm of the motor generator 21 is set within a high efficiency rotation region. While maintaining, the power of the motor generator 21 is increased or decreased, and the output torque Tm of the motor generator 21 is increased or decreased to change the second torque T2.

  For example, a case where the required torque T ′ does not change will be described as an example. In this example, it is assumed that the pulley ratio R of the CVT 16 does not change. When the water temperature t1 is higher than the optimum water temperature range Δt1 or when the catalyst temperature t2 is higher than the optimum catalyst temperature range Δt2, the load Q of the engine 10 is set to the low load QL by the load setting means M1. The first torque T1 decreases. The output torque Tm of the motor generator 21 is increased so that the decreased amount is supplemented by the second torque T2. On the other hand, when the water temperature t1 is lower than the optimum water temperature range Δt1 or when the catalyst temperature t2 is lower than the optimum catalyst temperature range Δt2, the load Q of the engine 10 is set to the high load QH by the load setting means M1. Accordingly, the first torque T1 increases. The output torque Tm of the motor generator 21 is decreased so that the increased amount is supplemented by the second torque T2.

The connection / disconnection means M5 is means for bringing the crankshaft clutch 17 into a connected state and a disconnected state. By implementing the connecting / disconnecting means M5, the crankshaft clutch 17 is brought into a contact state to connect between the engine 10 and the motor generator 21, while the crankshaft clutch 17 is brought into a disconnection state. 10 and the motor generator 21 are disconnected.

  If this connection / disconnection means M5 is implemented, the second torque T2 becomes zero. For example, when the required torque T ′ can be satisfied only by the first torque T1, the connecting / disconnecting means M5 is implemented to make the second torque T2 zero.

  A power transmission method according to the second embodiment will be described with reference to the flowchart of FIG. In this power transmission method, instead of step S80 in the flowchart of FIG. 2 described above, the output torque changing means M4 is implemented to increase or decrease the power of the motor generator 21 to output torque of the motor generator 21. Step S90 for changing Tm is performed.

  As a result, the excess or deficiency due to the first torque T1 can be obtained from the motor generator 21 without changing the efficiency of the electrical characteristics of the motor generator 21 only by changing the output torque Tm of the motor generator 21. It can be easily supplemented with the second torque T2 output via the CVT 16.

  The torque changing means M2 can be provided with both the gear ratio changing means M3 and the output torque changing means M4. In that case, while limiting the rotation speed Nm of the motor generator 21 to the high efficiency rotation region, the step of changing the pulley ratio R of the CVT 16 and changing the output torque Tm of the motor generator 21 is performed.

  When the second torque T2 is set to zero, the connecting / disconnecting means M5 may be implemented to disengage the engine 10 and the motor generator 21 by disengaging the crankshaft clutch 17. .

  According to the hybrid systems 2 and 2A, the hybrid vehicles 1 and 1A, and the power transmission method thereof according to the first and second embodiments of the present invention, the electric motor is operated so as not to reduce the efficiency of the electric characteristics of the motor generator 21. Since the second torque T2 output from the generator 21 via the CVT 16 is changed, the output of the engine 10 set to the load Q based on the coolant temperature t1 of the cooling water and the catalyst temperature t2 of the catalyst of the exhaust gas purification device 14. The difference between the first torque T1 to be performed and the required torque T ′ required for traveling of the hybrid vehicle 1 can be compensated.

  Thereby, the motor generator 21 can be driven with high efficiency without reducing the regeneration efficiency and drive efficiency of the motor generator 21. When the load Q of the engine 10 is set to the high load QH in the case of a low water temperature or a low catalyst temperature, the combined torque T of the first torque T1 and the second torque T2 does not become excessive with respect to the required torque T ′. Thus, when the second torque T2 output from the motor generator 21 is reduced and, on the contrary, the load Q of the engine 10 is set to the low load QL in the case of a high water temperature or a high catalyst temperature, the total torque T is required. The second torque T2 can be increased so as not to be insufficient with respect to the torque T ′.

  As a result, since the total torque T satisfies the required torque T ′, the cooling water temperature t1 and the catalyst temperature t2 of the catalyst are maintained in an appropriate range without deteriorating the operability, so that the exhaust gas discharged from the engine 10 It is possible to obtain effects such as a reduction in fuel consumption and an improvement in fuel consumption due to a reduction in loss of the engine 10 and the motor generator 21.

  Further, since the power of the crankshaft 15 of the engine 10 is transmitted to the motor generator 21 using the CVT 16, the rotation shaft of the motor generator 21 does not depend on the fluctuation of the rotational speed Ne of the crankshaft 15 of the engine 10. The rotation speed Nm of the motor generator 21 can be controlled to be suitable for the power generation or driving of the motor generator 21.

  Therefore, the motor generator 21 can be used in a state where the efficiency of the electrical characteristics is high by limiting the use rotation range of the rotation speed Nm in the motor generator 21, and energy during power generation and electric drive Efficiency can be increased.

  Furthermore, on the motor generator 21 side, it is not necessary to employ an excessively structured bearing structure and a high-strength structure necessary for ensuring reliability so that the motor generator 21 can be used at an excessive number of revolutions. The motor generator 21 and the hybrid system 2 can be reduced in size and weight.

  Note that the engine 10 of the hybrid system 2, 2A of the above embodiment can be applied to a diesel engine or a gasoline engine, and the number of cylinders and the arrangement thereof are not limited.

  Further, the motor generator 21 is different from a direct-winding DC motor in which the torque decreases as the rotation speed increases, which is used for a general starter motor or the like, and assists the driving force by a power running operation or regenerates by an excessive driving force. It is desirable to use an induction motor or a synchronous motor that can generate electric power when it is operated and generates a constant torque until a certain rotation.

  In addition, the hybrid system 2 described above can be configured such that a plurality of motor generators are provided by arranging another motor generator in series with the motor generator 21. By providing a plurality of motor generators, the degree of freedom in design increases, so it is possible to cope with various specifications. Even if only one motor generator 21 is used as a standard specification, another motor generator can be easily added later as an option, so the basic layout can be made the same, and the number of parts, weight, and cost can be reduced. Can be reduced.

  Furthermore, the crankshaft clutch 17 may be any device capable of separating the crankshaft 15 of the engine 10 and the drive shaft of the motor generator 21, for example, a friction clutch, an electromagnetic clutch (powder clutch). , And fluid couplings can be used. Moreover, the arrangement | positioning place may be between a 2nd pulley and the motor generator 21, and when providing several motor generators, you may provide between motor generators.

  In addition, an output torque changing means M4 is provided instead of the gear ratio changing means M3 of the torque changing means M2 of the first embodiment, and the second torque T2 is changed by the output torque changing means M4. Also good. Further, the second torque T2 output from the motor generator 21 via the CVT 16 may be changed by using both the gear ratio changing means M3 and the output torque changing means M4 as the torque changing means M2. .

  Since the hybrid system and the control method of the hybrid system of the present invention change the second torque output from the motor generator via the continuously variable transmission mechanism so as not to reduce the efficiency of the electric characteristics of the motor generator. The difference between the first torque output from the internal combustion engine with a load set based on the coolant temperature and the catalyst temperature of the catalyst of the exhaust gas purification device and the required torque required for traveling of the vehicle can be compensated.

As a result, the motor generator can be driven with high efficiency without reducing the regenerative efficiency and drive efficiency, and the combined torque of the first torque and the second torque satisfies the required torque without reducing the drivability. In addition, by maintaining the temperature of the cooling water and the catalyst within an appropriate range, it is possible to obtain an effect such as a reduction in exhaust gas and an improvement in fuel consumption due to a reduction in loss of the internal combustion engine and the motor generator. It can be used for a hybrid vehicle combined with a machine.

1, 1A vehicle (hybrid vehicle: HEV)
2, 2A Hybrid system 10 Engine (Internal combustion engine)
DESCRIPTION OF SYMBOLS 11 Engine main body 12 Exhaust passage 13 Turbo supercharger 14 Exhaust gas purification apparatus 15 Crankshaft 16 CVT (continuously variable transmission mechanism)
17 Crankshaft clutch (power connection / disconnection device)
20 Electric power system 21 Motor generator (M / G)
22 Wiring 23 Inverter (INV)
24A First battery (B)
24B Second battery (B)
25 DC-DC converter (CON)
26A Cooling fan (auxiliary machine)
26B Cooling water pump (auxiliary machine)
26C Lubricating oil pump (auxiliary machine)
30 Power transmission system 31 Transmission
32 Propeller shaft
33 Differential (differential gear)
34 Drive shaft
35 Wheel 40 Overall control device 41, 41A Control device for hybrid system

Claims (7)

In a hybrid system having an internal combustion engine and a motor generator, a continuously variable transmission mechanism is provided directly connected to the crankshaft of the internal combustion engine, the motor generator is connected to the continuously variable transmission mechanism,
Load setting means for setting a load of the internal combustion engine based on at least one of a coolant temperature for cooling the internal combustion engine and a catalyst temperature of a catalyst provided in an exhaust gas purification device of an exhaust passage of the internal combustion engine; The combined torque of the first torque output from the internal combustion engine corresponding to the load set by the load setting means and the second torque output from the motor generator via the continuously variable transmission mechanism is the travel of the vehicle. A hybrid system comprising: a control device having torque changing means for changing the second torque so as to obtain a required torque required for the operation.   2. The hybrid system according to claim 1, wherein the torque changing unit is a unit that changes the second torque while limiting a rotation speed of the motor generator to a predetermined high-efficiency rotation region.   The hybrid system according to claim 1 or 2, wherein the torque changing means is provided with a speed ratio changing means for changing the second torque by changing a speed ratio of the continuously variable transmission mechanism.   The hybrid according to any one of claims 1 to 3, wherein the torque changing means is provided with output torque changing means for changing the second torque by changing an output torque of the motor generator. system.   A hybrid vehicle equipped with the hybrid system according to any one of claims 1 to 4.   In a power transmission method of a hybrid system having an internal combustion engine and a motor generator, when power transmission is performed between the crankshaft and the motor generator via a continuously variable transmission mechanism directly connected to the crankshaft of the internal combustion engine. A load of the internal combustion engine is set based on at least one of a water temperature of cooling water for cooling the internal combustion engine and a catalyst temperature of a catalyst provided in an exhaust gas purification device of an exhaust passage of the internal combustion engine, The combined torque of the first torque output from the internal combustion engine corresponding to the above and the second torque output from the motor generator via the continuously variable transmission mechanism is a required torque required for traveling of the vehicle. A power transmission method for a hybrid system, wherein the second torque is changed.   The second torque is changed while limiting the number of rotations of the motor generator to a predetermined high-efficiency rotation region so that the total torque becomes a required torque required for traveling of the vehicle. Item 7. A power transmission method for a hybrid system according to Item 6.

Images