Hybrid vehicle

Abstract

To enable power consumption to be reduced as much as possible while enabling the battery warming process to be accelerated without starting an engine before the battery reaches an optimal temperature in a hybrid vehicle mounted with a seat heater.SOLUTION: A hybrid vehicle 100 comprises a vehicle interior heating device 7, a battery warming device 8, a seat heater 9, and a control device 20. The vehicle interior heating device 7 has: a first circulation passage 71; a first heat exchanger 72; an electric heater 73; a circulation pump 74; a bypass passage 75; and a flow rate control valve 76. The battery warming device 8 has: a second circulation passage 81; a second heat exchanger 82; and a circulation pump 83. When the vehicle is decelerated during EV travel by a motor MG2, the battery 6 has not yet been warmed up and the seat heater 9 is turned on, the control device 20 sets the flow rate control valve 76 to a second state (in which engine cooling water which has passed through the electric heater 73 is supplied to the first heat exchanger 72 while also being supplied to the bypass passage 75.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to hybrid vehicles. [Background technology]

[0002] For example, Patent Document 1 states that "when hybrid vehicle 100 is stopped or in EV mode and there is a request not only for battery warm-up but also for heating the passenger compartment, ECU 20 does not stop engine 1, even when hybrid vehicle 100 is stopped or in EV mode, but instead causes motor MG1 to generate electricity using the output of engine 1, and operates passenger compartment heater 7 and battery heater 8 using the electricity generated by motor MG1." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-248888 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned Patent Document 1, the vehicle interior heater 7 and the battery heater 8 are operated by the power generated by the motor MG1, which tends to increase power consumption. Therefore, if a seat heater is also installed, there is a concern that power consumption will be further increased.

[0005] The inventors of the present application have devised a configuration for a hybrid vehicle in which engine coolant is supplied from the engine to an interior heat exchanger, and the interior of the vehicle is heated by heating the engine coolant in this interior heat exchanger with an electric heater, and a battery heat exchanger is used to warm up the battery by using the heat of the engine coolant in the interior heat exchanger.

[0006] However, in this configuration, it takes time to warm up the battery using the heat of the engine coolant in the vehicle interior heat exchanger before the warm-up of the engine coolant in the vehicle interior heat exchanger is complete. Here, it has been discovered that when the battery is not warmed up, it is necessary to switch to a mode that limits the amount of regeneration of electric power generated by the motor during deceleration (also called battery regeneration amount), which requires starting the engine and heating the engine coolant supplied to the vehicle interior heat exchanger to promote the warm-up of the battery, resulting in reduced fuel efficiency.

[0007] In view of these circumstances, the present invention aims to reduce power consumption as much as possible in a hybrid vehicle equipped with a seat heater, while also facilitating the warm-up of the battery without having to start the engine before the battery warms up. [Means for solving the problem]

[0008] The present invention provides a hybrid vehicle including an engine and a motor as drive sources, a battery that supplies power to the motor and charges the motor with regenerative power, an interior heating device that heats the interior of the vehicle, a battery warming device that warms up the battery, a seat heater that heats the seats, and a control device that controls the interior heating device, the battery warming device, and the seat heater, wherein the interior heating device includes a first circulation path through which engine coolant supplied from the engine circulates, a first heat exchanger connected midway through the first circulation path and that heats the interior of the vehicle by dissipating heat from the engine coolant flowing therethrough, an electric heater that heats the engine coolant flowing through the first circulation path, a circulation pump that circulates the engine coolant in the first circulation path, and a bypass path connected to bypass the first heat exchanger. and a flow control valve that is arranged upstream of the first heat exchanger in the first circulation path and that switches the first state of the engine coolant that has passed through the electric heater to only the first heat exchanger, or the second state of the engine coolant that has passed through the electric heater to the first heat exchanger while also circulating the engine coolant in the bypass path; the battery warm-up device includes a second circulation path arranged near the battery, a second heat exchanger connected midway through the second circulation path and for exchanging heat between the fluid circulating therein and the engine coolant circulating in the bypass path, and a circulation pump that circulates the fluid in the second circulation path; and the control device switches the flow control valve to the second state when the battery is not yet warmed up and the seat heater is on during deceleration during EV driving using the motor.

[0009] In this configuration, the battery warm-up device is not equipped with an electric heater, which makes it possible to reduce power consumption compared to a case in which both the vehicle interior heating device and the battery warm-up device are equipped with electric heaters.

[0010] In addition, in the above configuration, when the hybrid vehicle is decelerated during EV driving using the motor, before the battery has warmed up and the seat heater is on, the seat heater and the vehicle interior heating device promote heating of the vehicle interior, and the battery warm-up device promotes warm-up of the battery.

[0011] This eliminates the need to start the engine and heat the engine coolant supplied to the first circulation path even before the battery has warmed up, thereby avoiding a decrease in fuel efficiency, and furthermore, since the warming up of the battery is promoted, the mode that limits the amount of battery regeneration can be released relatively quickly.

[0012] In the above hybrid vehicle, the control device may include a first determination unit that determines whether warm-up of the battery is complete when it recognizes that deceleration has occurred during EV driving using the motor; a first processing unit that switches to a mode that limits the amount of battery regeneration if the first determination unit makes a negative determination; a second determination unit that determines whether the required amount of regeneration is greater than the limited amount of battery regeneration; a second processing unit that switches the flow rate adjustment valve to the second state if the second determination unit makes a negative determination; a third determination unit that determines whether the coolant flowing through the first circulation path is below a predetermined warm-up completion temperature if the second determination unit makes a positive determination; a fourth determination unit that executes the second processing unit if the third determination unit makes a negative determination, and determines whether the seat heater is off if the fourth determination unit makes a positive determination; and a third processing unit that executes the second processing unit if the fourth determination unit makes a negative determination, and starts the engine if the fourth determination unit makes a positive determination. [Effects of the Invention]

[0013] The present invention makes it possible to reduce power consumption as much as possible in a hybrid vehicle equipped with a seat heater, and to promote warming up of the battery without starting the engine before warming up the battery. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram showing the configuration of an embodiment of a hybrid vehicle according to the present invention; [Figure 2] FIG. 2 is a diagram illustrating a configuration of a vehicle interior heating device and a battery warm-up device. [Figure 3] FIG. 4 is a flowchart illustrating the operation of the control device. [Figure 4] 10 is a graph showing the relationship between the temperature of the battery and the amount of regeneration of the battery. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0016] 1 to 4 show one embodiment of the present invention. The illustrated hybrid vehicle 100 includes an engine (internal combustion engine) 1, axles 2, wheels 3, motors (motor generators) MG1 and MG2, a planetary gear (planetary gear mechanism) 4, an inverter 5, a battery 6, a vehicle interior heating device 7, a battery warm-up device 8, a seat heater 9, a control device 20, and the like.

[0017] The axle 2 is part of a power transmission system that transmits the power of the engine 1 and the motor MG2 to the wheels 3. The wheels 3 are the wheels of the hybrid vehicle 100, and for simplicity of explanation, only the left and right front wheels are shown in Fig. 1. The engine 1 is constituted by a gasoline engine or the like, and functions as a power source that outputs the main propulsive force of the hybrid vehicle 100.

[0018] The motor MG1 is configured to function mainly as a generator for charging the battery 6 or as a generator for supplying power to the motor MG2, and generates power using the output of the engine 1.

[0019] The motor MG2 is configured to function mainly as an electric motor that assists (supports) the output of the engine 1. For example, when the hybrid vehicle 100 runs on electricity (EV running), the motor MG2 serves as the drive source instead of the engine 1.

[0020] Motors MG1 and MG2 are configured, for example, as synchronous motor-generators, and although not shown, include a rotor having multiple permanent magnets on its outer circumferential surface and a stator wound with a three-phase coil that forms a rotating magnetic field.

[0021] The planetary gear 4 is configured to be able to distribute the output of the engine 1 to the motor MG1 and the axle 2, and functions as a power split mechanism.

[0022] The inverter 5 is a DC / AC converter that controls the input and output of power between the battery 6 and the motors MG1 and MG2.

[0023] This inverter 5 is configured to convert DC power taken from the battery 6 into AC power, or to supply AC power generated by the motor MG1 to the motor MG2, and also to convert AC power generated by the motor MG1 into DC power and supply it to the battery 6.

[0024] The battery 6 is a rechargeable storage battery configured to be able to function as a power source for driving the motors MG1 and MG2.

[0025] The vehicle interior heating device 7 is a device for heating the vehicle interior of the hybrid vehicle 100, and as shown in FIG. 2, includes a first circulation path 71, a first heat exchanger 72, an electric heater 73, a circulation pump 74, a bypass path 75, and a flow control valve 76.

[0026] The first circulation path 71 is a passage through which the coolant supplied from the engine 1 circulates. The first heat exchanger 72 is a heater core connected midway through the first circulation path 71, and heats the interior of the vehicle by releasing heat from the coolant flowing inside the first heat exchanger 72 into the vehicle interior.

[0027] The electric heater 73 is driven by the electric power supplied from the battery 6 to heat the cooling water flowing through the first circulation path 71 .

[0028] The circulation pump 74 circulates the engine cooling water in the first circulation path 71 .

[0029] The bypass path 75 is connected to the first circulation path 71 so as to bypass the first heat exchanger 72 .

[0030] The flow control valve 76 is installed in the first circulation path 71 and switches between a first state (see dashed arrow in Figure 3) in which the engine cooling water that has passed through the electric heater 73 flows only through the first heat exchanger 72, and a second state (see dashed arrow in Figure 3) in which the engine cooling water that has passed through the electric heater 73 flows through the first heat exchanger 72 while also flowing through the bypass path 75.

[0031] The temperature inside the vehicle interior of the hybrid vehicle 100 is detected by a vehicle interior temperature sensor 11 , and a detection signal corresponding to the detected temperature inside the vehicle interior is transmitted to the control device 20 .

[0032] The battery warm-up device 8 is a device that warms up the battery 6, and as shown in FIG. 2, includes a second circulation path 81, a second heat exchanger 82, and a circulation pump 83.

[0033] The second circulation path 81 is a passage through which a fluid (such as the same as engine coolant) circulates, and a part of it is disposed near the battery 6.

[0034] The second heat exchanger 82 is provided in the middle of the second circulation path 81 and exchanges heat between the fluid flowing therethrough and the engine coolant flowing through the bypass path 75 of the vehicle interior heating device 7 .

[0035] The circulation pump 83 circulates the fluid in the second circulation path 81 .

[0036] The temperature of the battery 6 is detected by the battery temperature sensor 12, and a detection signal corresponding to this detected temperature of the battery 6 is sent to the control device 20.

[0037] The seat heater 9 is an electric heater that heats the seat, and is controlled by the control device 20 in response to the operation of a switch (not shown) by the occupant.

[0038] The control device 20 is an electronic control unit that controls the engine 1, the motors MG1 and MG2, etc., and controls the overall operation of the equipment of the hybrid vehicle 100, etc.

[0039] Furthermore, when the hybrid vehicle 100 decelerates, the control device 20 charges the battery 6 with regenerative power generated by the motor MG1. The amount of regenerative power charged to the battery 6 in this manner is referred to as the "battery regeneration amount." Furthermore, before the battery 6 is warmed up, that is, when the temperature of the battery 6 is lower than the warm-up completion temperature, the charge and discharge characteristics of the battery 6 deteriorate, so the control device 20 switches to a mode that limits the battery regeneration amount and raises the temperature of the battery 6 to promote warm-up in order to avoid deterioration of the charge and discharge characteristics of the battery 6.

[0040] The control device 20 is an ECU (Electronic Control Unit), which includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, all of which are not shown.

[0041] Next, the operation of the control device 20 will be described with reference to Figures 3 and 4. The control device 20 starts the flowchart shown in Figure 3 when it recognizes that the hybrid vehicle 100 has decelerated while the interior of the vehicle is being heated (the flow rate control valve 76 is in the first state) during EV driving.

[0042] In step S1, it is determined whether or not the warm-up of the battery 6 is complete. Specifically, in step S1, it is determined based on the detection signal of the battery temperature sensor 12 whether or not the temperature (°C) of the battery 6 is equal to or higher than a predetermined warm-up completion temperature T' (see FIG. 4).

[0043] If the determination in step S1 is affirmative, that is, if the warm-up of the battery 6 has been completed, the flow chart ends, whereas if the determination is negative, that is, if the warm-up of the battery 6 has not yet been completed, the flow proceeds to step S2.

[0044] In step S2, a mode is set in which the amount of battery regeneration is limited, and then the process proceeds to step S3.

[0045] In step S3, it is determined whether the required regeneration amount Wγ is greater than the limited battery regeneration amount WT. As shown in Fig. 4, when the temperature (°C) of the battery 6 is at the pre-warm-up temperature T, the control device 20 sets the mode to limit the battery regeneration amount, i.e., sets the battery regeneration amount (kw) to the limited battery regeneration amount WT, but when the temperature of the battery 6 is at the warm-up completion temperature T', it sets the mode to the normal mode in which the battery regeneration amount is not limited, i.e., sets the battery regeneration amount to the unlimited battery regeneration amount WT'. The required regeneration amount Wγ depends on the deceleration rate of the hybrid vehicle 100.

[0046] In this step S3, if the judgment is negative, that is, if "requested regeneration amount Wγ≦limited battery regeneration amount WT", the process proceeds to step S4, whereas if the judgment is positive, that is, if "requested regeneration amount Wγ>limited battery regeneration amount WT", the process proceeds to step S5.

[0047] First, in step S4, a process is executed to complete the warm-up by increasing the temperature of the battery 6. Specifically, in step S4, the electric heater 73 and the circulation pumps 74, 83 are turned on, and the flow rate adjustment valve 76 is set to the second state, and then the process returns to step S1.

[0048] 2, the second state is a state in which the engine coolant that has passed through the electric heater 73 is circulated through the first heat exchanger 72 and also through the bypass path 75. In this second state, the engine coolant heated by the electric heater 73 of the vehicle interior heating device 7 can be used to heat the vehicle interior and the battery 6.

[0049] In step S5, it is determined whether the warm-up of the engine coolant flowing through the first circulation path 71 of the vehicle interior heating device 7 has not yet been completed, that is, whether the temperature of the engine coolant is below a predetermined warm-up completion temperature.

[0050] If the determination in step S5 is negative, i.e., if the warm-up of the engine cooling water has been completed, the process proceeds to step S4, whereas if the determination is positive, i.e., if the warm-up of the engine cooling water has not yet been completed, the process proceeds to step S6.

[0051] In step S6, it is determined whether or not the seat heater 9 is off. If the determination in step S6 is negative, that is, if the seat heater 9 is on, the process proceeds to step S4. On the other hand, if the determination is positive, that is, if the seat heater 9 is off, the process proceeds to step S7, in which the engine is started to raise the temperature of the engine coolant, and this engine coolant is supplied into the first circulation path 71, thereby raising the temperature of the engine coolant in the first circulation path 71 relatively quickly. Thereafter, the process returns to step S1.

[0052] In this way, when the seat heater 9 is on, it also contributes to raising the temperature inside the vehicle cabin. Therefore, if the flow rate adjustment valve 76 is set to the second state while the seat heater 9 is on, the temperature inside the vehicle cabin can be raised by both the seat heater 9 and the first heat exchanger 72 of the vehicle cabin heating device 7, thereby accelerating the heating of the vehicle cabin. In addition, since the engine coolant in the first circulation path 71 can be heated by the electric heater 73 while the fluid in the second circulation path 81 can be heated by the second heat exchanger 82 of the battery warm-up device 8, warm-up of the battery 6 can be promoted without starting the engine 1.

[0053] In the flowchart shown in FIG. 3, step S1 corresponds to the first judgment unit described in the claims, step S2 corresponds to the first processing unit, step S3 corresponds to the second judgment unit, step S4 corresponds to the second processing unit, step S5 corresponds to the third judgment unit, step S6 corresponds to the fourth judgment unit, and step S7 corresponds to the third processing unit.

[0054] As described above, according to the embodiment to which the present invention is applied, the battery warm-up device 8 is not equipped with an electric heater, and therefore it is possible to reduce power consumption compared to the case in which both the vehicle interior heating device 7 and the battery warm-up device 8 are equipped with electric heaters.

[0055] In addition, in the above embodiment, when the hybrid vehicle 100 is decelerated during EV driving using the motor MG2, before the battery 6 has been warmed up and the seat heater 9 is on, the seat heater 9 and the vehicle interior heating device 7 are used to raise the temperature inside the vehicle interior, and the battery warming device 8 is used to promote warming up of the battery 6.

[0056] This eliminates the need to start the engine 1 and heat the engine coolant supplied to the first circulation path 71 even before the battery 6 has warmed up, thereby avoiding a decrease in fuel efficiency, and furthermore, since the warming up of the battery 6 is promoted, the mode that limits the amount of battery regeneration can be released relatively quickly.

[0057] Therefore, in the above embodiment, in a hybrid vehicle 100 equipped with a seat heater 9, it is possible to reduce power consumption as much as possible and promote warming up of the battery 6 without starting the engine 1 before warming up the battery 6.

[0058] The present invention is not limited to the above-described embodiments, but can be modified as appropriate within the scope of the claims and the equivalents thereof.

[0059] (1) In the above embodiment, an example is given in which the control device 20 controls both the engine 1 and the motors MG1, MG2, etc., but the present invention is not limited to this.

[0060] For example, although not shown, if a control device that controls the engine 1 and a control device that controls the motors MG1 and MG2 are provided separately, the respective control devices can be configured to cooperate to perform the respective controls. [Industrial Applicability]

[0061] The present invention can be suitably used in hybrid vehicles. [Explanation of symbols]

[0062] 100 Hybrid Vehicles 1 engine MG1 motor MG2 motor 2 axles 3 wheels 4 Planetary Gear 5 inverters 6 batteries 7. Vehicle interior heating system 71 1st circulation route 72 1st heat exchanger 73 Electric heater 74 Circulation Pump 75 Bypass Road 76 Flow control valve 8 Battery warm-up device 81 Second circulation route 82 Second heat exchanger 83 Circulation Pump 9 Seat heater 11 Vehicle interior temperature sensor 12 Battery temperature sensor 20 Control device

Claims

1. A hybrid vehicle including an engine and a motor as drive sources, a battery that supplies power to the motor and is charged with regenerative power from the motor, a vehicle interior heating device that heats the vehicle interior, a battery warm-up device that warms up the battery, a seat heater that heats a seat, and a control device that controls the vehicle interior heating device, the battery warm-up device, and the seat heater, the vehicle interior heating device includes: a first circulation path through which engine coolant supplied from an engine circulates; a first heat exchanger connected midway through the first circulation path and configured to heat the vehicle interior by dissipating heat from the engine coolant flowing therethrough into the vehicle interior; an electric heater that heats the engine coolant flowing through the first circulation path; a circulation pump that circulates the engine coolant in the first circulation path; a bypass path connected to bypass the first heat exchanger; and a flow control valve that is located upstream of the first heat exchanger in the first circulation path and configured to switch the engine coolant that has passed through the electric heater to a first state in which it flows only through the first heat exchanger, or a second state in which it flows the engine coolant that has passed through the electric heater to the first heat exchanger while also flowing through the bypass path, the battery warm-up device includes a second circulation path disposed near the battery, a second heat exchanger connected midway through the second circulation path for exchanging heat between fluid flowing therethrough and engine coolant flowing through the bypass path, and a circulation pump for circulating the fluid in the second circulation path; The control device sets the flow rate adjustment valve to the second state when the vehicle is decelerated during EV driving using a motor, before the battery has warmed up, and when the seat heater is on.

2. 2. The hybrid vehicle according to claim 1, a first determination unit that determines whether warm-up of the battery has been completed when the control device recognizes that deceleration has occurred during EV running by the motor; and a first processing unit that switches the mode to a mode that limits the amount of battery regeneration when a negative determination is made by the first determination unit; a second determination unit that determines whether a required regeneration amount is greater than a limited battery regeneration amount; a second processing unit that sets the flow rate adjustment valve to the second state when a negative determination is made by the second determination unit; a third determination unit that determines whether the temperature of the cooling water flowing through the first circulation path is lower than a predetermined warm-up completion temperature when the second determination unit makes a positive determination; a fourth determination unit that executes the second processing unit when the third determination unit makes a negative determination, and determines whether the seat heater is off when the third determination unit makes an affirmative determination; a third processing unit that executes the second processing unit when the fourth determination unit makes a negative determination, and starts the engine when the fourth determination unit makes a positive determination.

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