JP2020009591A - Drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive unit having a simple structure and capable of achieving both temperature control of a drive unit and temperature control of a secondary battery. SOLUTION: A drive unit (3) mounted on a vehicle (1) and generating heat when operated, a cooling unit (29) for cooling the drive unit, and a heat medium can be distributed between the drive unit and the cooling unit. The heat medium circuit (30) to be connected, the high temperature heat medium passages (32, 33) provided in the heat medium circuit for circulating the heat medium from the drive unit to the cooling unit, and mounted in the vehicle to drive the vehicle. A motor (5, 7) and a secondary battery (21) for supplying electric power to the motor are provided, and the secondary battery is an all-solid-state battery containing lithium in a solid electrolyte. It is connected to the medium passage. [Selection diagram] Figure 2

Description

  The present invention relates to a driving unit, and more particularly, to a technique for adjusting a temperature of a secondary battery provided in the driving unit.

2. Description of the Related Art In recent years, hybrid vehicles, which have been widely used, are equipped with an engine, a motor, and a battery for storing electric power supplied to the motor.
Since these engines, motors, and batteries generate heat when they operate, they are each provided with a cooling device such as a radiator.
On the other hand, the engine, the motor, and the battery have an appropriate temperature during operation, and when the temperature is low, it is necessary to warm up without cooling.

  Therefore, a technique for heating and cooling a battery using cooling water and a radiator used for cooling an engine has been developed (Patent Document 1).

JP-A-2017-222239

By the way, most lithium ion batteries using an electrolyte containing lithium ions in the electrolyte, such as the technology disclosed in Patent Document 1, have a maximum usable temperature of 60 ° C., mainly from the viewpoint of preventing deterioration. The appropriate temperature is 40 ° C.
On the other hand, the temperature of the cooling water during operation of the engine is 70 ° C to 100 ° C.
Therefore, in order to heat and cool the battery via the cooling water used for cooling the engine, it is necessary to adjust the temperature of the cooling water flowing through the battery. For this reason, as in the technique disclosed in Patent Document 1, in order to heat the battery via the heating device, it is necessary to adjust so as not to overheat, and the entire apparatus becomes complicated. There was a fear. Further, there has been a problem that the whole device is further complicated to cool the battery.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a simple configuration to achieve both temperature adjustment of an engine (drive unit) and temperature adjustment of a battery (secondary battery). It is an object of the present invention to provide a drive unit capable of performing the following.

  In order to achieve the above object, a drive unit of the present invention is mounted on a vehicle and generates heat by operating, a drive unit that cools the drive unit, and heat generated by the drive unit and the cooling unit. A heat medium circuit that connects a medium so that the medium can flow therethrough, a high-temperature heat medium passage that is provided in the heat medium circuit, and that circulates the heat medium from the drive unit toward the cooling unit; And a secondary battery for supplying power to the motor, wherein the secondary battery is an all-solid battery containing lithium in a solid electrolyte, and the high-temperature heat medium passage of the heat medium circuit. Characterized by being connected to

  Thus, by using the all-solid-state battery containing lithium in the solid electrolyte as the secondary battery, it is possible to efficiently use the all-solid-state secondary battery that is convenient to operate at a high temperature. In addition, by connecting the secondary battery to a high-temperature heat medium passage that circulates the heat medium from the drive unit of the heat medium circuit toward the cooling unit, the heat medium heated by the drive unit can be cooled without cooling. The secondary battery can be circulated and heated.

In another aspect, the drive unit is preferably an internal combustion engine that operates by burning fuel.
This allows the internal combustion engine to operate by burning fuel and generate heat, thereby heating the heat medium flowing through the secondary battery.
As another aspect, a first opening / closing valve that is provided in the heat medium circuit and opens when the heat medium is equal to or higher than a predetermined temperature, and is provided in the heat medium circuit, and is provided from the cooling unit of the heat medium circuit. A low-temperature heat medium passage for allowing the heat medium to flow toward the drive unit; and a low-temperature heat medium passage extending from the high-temperature heat medium passage of the heat medium circuit and connected to the low-temperature heat medium passage. A first bypass passage through which the heat medium flows, and the first on-off valve is disposed between the secondary battery and the cooling unit in the high-temperature heat medium passage, It is preferable that the bypass passage extends from the high-temperature heat medium passage between the secondary battery and the first on-off valve.

  Thereby, the first on-off valve is disposed between the secondary battery in the high-temperature heat medium passage and the cooling unit, and the first bypass passage extends from between the secondary battery in the high-temperature heat medium passage and the first on-off valve. To connect the heating medium heated by the driving unit to the secondary battery and cool the heating medium according to the temperature of the heating medium heated or cooled by the secondary battery. It is possible to select whether or not to use the first on-off valve.

When the temperature of the heat medium is equal to or higher than the predetermined temperature, the first on-off valve is opened and the heat medium is cooled by the cooling unit. On the other hand, when the temperature of the heat medium is lower than the predetermined temperature, the first on-off valve is closed and the heat medium is cooled. Thus, the secondary battery can be efficiently heated until the temperature of the heat medium becomes equal to or higher than the predetermined temperature.
As another aspect, a second bypass passage connecting an upstream side of the secondary battery in the heat medium circuit and a downstream side of the secondary battery in the heat medium circuit and upstream of a driving unit, A second on-off valve that is provided in the medium circuit and opens when the heat medium is at or above a certain temperature, wherein the second on-off valve is connected between the secondary battery and an upstream side of the second bypass passage. Preferably, it is arranged between them.

  Thus, when the heat medium is at or above a certain temperature, the second on-off valve opens and the heat medium flows through the secondary battery, while when the heat medium is below a certain temperature, the second on-off valve closes and heat medium is turned on. By preventing the secondary battery from flowing through the secondary battery, it is possible to prevent the secondary battery from being cooled by the thermal medium until the temperature of the thermal medium becomes equal to or higher than a certain temperature.

  ADVANTAGE OF THE INVENTION According to the drive unit of this invention, while making a rechargeable battery an all-solid-state battery, cooling of a rechargeable battery becomes unnecessary and a rechargeable battery transfers heat medium from the drive part of a heat medium circuit toward a cooling part. Since it is connected to the high-temperature heat medium passage to be circulated, the heat medium heated by the drive unit can be circulated to the secondary battery without cooling, thereby heating the all-solid-state secondary battery, which is convenient for operation at a high temperature. it can.

  Thereby, both the temperature adjustment of the driving unit and the temperature adjustment of the secondary battery can be achieved with a simple configuration.

FIG. 1 is a schematic configuration diagram of a vehicle according to a first embodiment. It is a schematic structure figure of a cooling circuit concerning a 1st embodiment. It is a schematic structure figure of a cooling circuit concerning a 2nd embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
<First embodiment>
FIG. 1 shows a schematic configuration diagram of a plug-in hybrid vehicle (hereinafter, referred to as a vehicle 1) according to a first embodiment.
The vehicle 1 is equipped with a drive unit 2 provided with an engine 3, a front motor 5 and a rear motor 7. The vehicle 1 is a hybrid four-wheel drive vehicle that can drive and drive the front wheel 9 and the rear wheel 11 by appropriately operating the engine 3, the front motor 5, and the rear motor 7.

The drive unit 2 includes an engine (drive unit) 3, a front motor (drive unit, motor) 5, a rear motor (drive unit, motor) 7, an all-solid-state battery (secondary battery) 21, and a radiator (cooling unit) 29. Have been.
The engine 3 is an internal combustion engine that operates by burning fuel supplied from a fuel tank (not shown). This internal combustion engine is cooled by circulating cooling water. In view of fuel efficiency and durability, for example, the cooling water ranges from 70 ° C. (predetermined temperature) to 100 ° C. (prescribed temperature) (operating temperature range). It is desirable to work with Further, the engine 3 can drive the generator 17 via the speed reducer 13 to generate power.

The speed reducer 13 has a built-in clutch 13 a capable of switching connection and disconnection of power transmission between the output shaft of the engine 3 and the drive shaft 15 of the front wheel 9. This allows the engine 3 to drive the front wheels 9 via the speed reducer 13 and the drive shaft 15 when the clutch 13a is in the connected state.
The front motor 5 is a motor that is supplied with high-voltage power from an all-solid-state battery 21 and a generator 17 described below via a front inverter 19 and drives the speed reducer 13. Thereby, the front motor 5 can drive the front wheels 9 via the speed reducer 13 and the drive shaft 15.

The rear motor 7 is a motor that is supplied with high-voltage power from the all-solid-state battery 21 and the generator 17 via the rear inverter 23 and drives the speed reducer 25. Thus, the rear motor 7 can drive the rear wheels 11 via the speed reducer 25 and the drive shaft 27.
The all-solid-state battery 21 is a secondary battery using a solid electrolyte containing lithium without using a liquid electrolyte at room temperature in which a lithium salt such as LiPF ₆ is dissolved in the electrolyte.

More specifically, the all-solid-state battery 21 includes LiCoO ₂ (lithium cobaltate) for the positive electrode, graphite for the negative electrode, and LGPS (for example, Li _9.54 Si _1.74 P _1.44 S _11.7 Cl _0.3 ) as the electrolyte. ), So that lithium ions can be exchanged (ion conduction) between the positive electrode and the negative electrode via the electrolyte. Here, LGPS (lithium-germanium-phosphorus-sulfur) used as an electrolyte is called a sulfide electrolyte. A battery using such a sulfide electrolyte has higher ion conduction efficiency (ion conductivity) than a battery using an oxide electrolyte, and thus has relatively high charge / discharge performance.

  The LGPS is a solid electrolyte at normal temperature and at a temperature (operating temperature, for example, −40 ° C. to 150 ° C.) that occurs during charging and discharging of the all-solid-state battery 21. That is, since the all-solid-state battery 21 has a solid electrolyte even at a high temperature (for example, 100 ° C.), side-reactive chemical reactions such as decomposition of anions and solvent molecules are relatively unlikely to occur on the surface of the positive electrode, and as a result, Deterioration hardly occurs. Therefore, the all-solid-state battery 21 can be used without failure up to a temperature (for example, 150 ° C.) higher than a specified temperature described later.

  Referring to FIG. 2, a schematic configuration diagram of a cooling circuit (heat medium circuit) 30 according to the first embodiment is shown. The radiator 29 is a heat exchanger disposed on the front side of the vehicle 1 (see FIG. 1) and capable of exchanging heat between outside air and cooling water (heat medium). The thermostat (first on-off valve) 36 gradually opens when the temperature of the cooling water flowing through a third passage 33 described later reaches a predetermined temperature (for example, 70 ° C.), and fully opens when the temperature reaches a specified temperature (for example, 100 ° C.). This is a temperature-sensitive on-off valve.

  The cooling circuit 30 includes a first passage (low-temperature heating medium passage) 31 for sending cooling water from the radiator 29 to the engine 3, a second passage (high-temperature heating medium passage) 32 for sending cooling water from the engine 3 to the all-solid-state battery 21, A circulation path is provided with a third passage (high-temperature heat medium passage) 33 for sending cooling water from the solid state battery 21 to the thermostat 36 and a fourth passage (high-temperature heat medium passage) 34 for sending cooling water from the thermostat 36 to the radiator 29. ing.

  Further, a pump 31a is provided in the first passage 31 of the cooling circuit 30. By driving the pump 31a, the cooling water can circulate through the cooling circuit 30. Further, a bypass passage (first bypass passage) 35 for sending cooling water from the third passage 33 upstream of the thermostat 36 to the first passage 31 is connected to a path connecting the radiator 29 of the first passage 31 and the pump 31a. Have been.

The engine 3 generates heat because it operates by burning fuel, but is cooled by exchanging heat with cooling water flowing in the engine water jacket 3a. That is, the cooling water flowing into the engine 3 from the first passage 31 is heated by the engine 3 and then flows through the second passage 32.
The cooling water flowing through the second passage 32 flows into the battery water jacket 21 a provided in the all-solid-state battery 21. The battery water jacket 21a can perform heat exchange between the all-solid-state battery 21 and the cooling water, similarly to the engine water jacket 3a of the engine 3. That is, the cooling water is cooled by the all-solid-state battery 21 when the temperature of the cooling water is higher than that of the all-solid-state battery 21, and is heated by the all-solid-state battery 21 when the temperature of the all-solid-state battery 21 is higher than that of the cooling water.

  By the way, in the second passage 32, a device (for example, a radiator) for cooling the cooling water heated by the engine 3 is not provided. Thereby, the all-solid-state battery 21 is heated by the high-temperature cooling water and may be heated to about the specified temperature. However, as described above, since the all-solid-state battery 21 hardly deteriorates even at a high temperature, There is no need to provide a device for cooling the cooling water in the second passage 32.

Also, batteries using lithium ions, including the all-solid-state battery 21, have the property that the higher the temperature, the higher the ionic conductivity and the higher the charge / discharge performance. In other words, the all-solid-state battery 21 can be improved in charge / discharge performance by being heated by the cooling water heated by the engine 3.
When the temperature of the all-solid-state battery 21 is higher than that of the cooling water, the cooling water can be heated by the all-solid-state battery 21, so that the temperature of the engine 3 can be increased faster.

  The cooling water that has exchanged heat with the all-solid-state battery 21 is discharged to the third passage 33 and flows to the thermostat 36. The thermostat 36 gradually opens when the temperature of the cooling water flowing through the third passage 33 becomes equal to or higher than a predetermined temperature. That is, when the temperature of the cooling water is equal to or higher than the predetermined temperature, the thermostat 36 opens the valve at an opening corresponding to the temperature of the cooling water and causes the cooling water to flow through the fourth passage 34.

The cooling water flowing through the fourth passage 34 flows through the radiator 29 and again flows through the first passage 31. The radiator 29 can cool the cooling water by performing heat exchange between the cooling water and the outside air. That is, the radiator 29 can cool the engine 3 by cooling the cooling water and flowing the cooling water through the first passage 31.
On the other hand, the thermostat 36 closes when the temperature of the cooling water is lower than the predetermined temperature. Further, even when the temperature of the cooling water is equal to or higher than the predetermined temperature, when the temperature of the cooling water is relatively close to the predetermined temperature, the opening of the thermostat 36 becomes narrow corresponding to the temperature of the cooling water.

  That is, part or all of the cooling water flowing through the thermostat 36 flows through the bypass passage 35 without flowing through the fourth passage 34. The cooling water flowing from the third passage 33 to the bypass passage 35 in this way flows again to the first passage 31 without being cooled by the radiator 29. Thereby, the engine 3 can warm the cooling water until it reaches the predetermined temperature.

  As described above, in the drive unit according to the first embodiment, the engine 3 that is mounted on the vehicle 1 and generates heat when operating, the radiator 29 that cools the engine 3, and the cooling water generated by the engine 3 and the radiator 29. A cooling circuit 30 for circulating the cooling water, a second passage 32 and a third passage 33 for flowing cooling water from the engine 3 toward the radiator 29, a motor mounted on the vehicle 1 for running the vehicle 1, and a motor. And an all-solid-state battery 21 that supplies power to the cooling circuit 30. The all-solid-state battery 21 is an all-solid-state battery that contains lithium in the solid electrolyte, and is connected to the second passage 32 and the third passage 33 of the cooling circuit 30. .

  Therefore, by using the all-solid-state battery 21 containing lithium as the solid electrolyte, the heat resistance of the secondary battery can be improved. Further, since the all-solid-state battery 21 is connected to the second passage 32 for flowing the cooling water from the engine 3 of the cooling circuit 30 toward the radiator 29, the all-solid-state battery 21 is cooled without cooling the cooling water heated by the engine 3. To heat the all-solid-state battery 21.

  In particular, since the engine 3 is an internal combustion engine that operates by burning fuel, it can heat the cooling water flowing through the all-solid-state battery 21. Furthermore, by adjusting the temperature of the engine 3 using cooling water, the temperature of the all-solid-state battery 21 is also adjusted at the same time. Here, as described above, the operating temperature range of the engine 3 is 70 ° C. to 100 ° C., and the operating temperature range of the all solid state battery 21 is −40 ° C. to 150 ° C. That is, by adjusting the temperature in the operating temperature range of the engine 3, the temperature of the all solid state battery 21 can be adjusted in the operating temperature range of the all solid state battery 21.

  A first passage 31 provided in the cooling circuit 30 for flowing cooling water from the radiator 29 of the cooling circuit 30 toward the engine 3; and a valve provided in the cooling circuit 30 to open when the cooling water is at a predetermined temperature or higher. A thermostat 36, and a bypass passage 35 extending from the second passage 32 of the cooling circuit 30 and connected to the first passage 31 for flowing cooling water from the second passage 32 toward the first passage 31. 36 is provided between the all-solid-state battery 21 in the second passage 32 and the radiator 29, and the bypass passage 35 extends from between the all-solid-state battery 21 in the second passage 32 and the thermostat 36.

Therefore, when the cooling water is at or above the predetermined temperature, the thermostat 36 is opened and the cooling water is cooled by the radiator 29. On the other hand, when the cooling water is below the predetermined temperature, the thermostat 36 is closed and the cooling water is not cooled by the radiator 29. Alternatively, the cooling water may not be cooled until the temperature of the cooling water becomes equal to or higher than the predetermined temperature.
Further, a thermostat 36 is disposed between the all-solid-state battery 21 in the second passage 32 and the radiator 29, and a bypass passage 35 extends from between the all-solid-state battery 21 in the second passage 32 and the thermostat 36 to extend through the first passage. By connecting the cooling water to the cooling water 31, the cooling water heated by the engine 3 is allowed to flow through the all-solid-state battery 21, and whether to cool the cooling water according to the temperature of the cooling water heated or cooled by the all-solid-state battery 21 is determined. The thermostat 36 can be selected.

<Second embodiment>
Hereinafter, the second embodiment will be described with reference to FIG.
The description of the same configuration as that of the first embodiment will be omitted, and only the portions different from the first embodiment will be described.
Referring to FIG. 3, a schematic configuration diagram of a cooling circuit 130 according to the second embodiment is shown.

  The cooling circuit (heat medium circuit) 130 according to the second embodiment includes a bypass passage (second bypass passage) 135 and a thermostat (second on-off valve) 136. The bypass passage 135 is a passage that connects the second passage 32 to the third passage 33 so that the cooling water can flow therethrough. The cooling water flowing through the bypass passage 135 does not flow through the battery water jacket 21 a of the all-solid-state battery 21.

Similar to the thermostat 36 according to the first embodiment, the thermostat 136 gradually opens when the temperature of the cooling water flowing through the second passage 32 reaches a predetermined temperature (for example, 60 ° C.), and the specified temperature (for example, 100 ° C.). ) Is a temperature-sensitive valve that opens fully when it becomes).
By providing the cooling circuit 130 according to the second embodiment with the bypass passage 135 and the thermostat 136, the cooling water flowing through the second passage 32 allows the all-solid-state battery 21 to cool when the temperature is lower than a certain temperature. It circulates through the third passage 33 without circulating.

That is, when there is a possibility that the temperature of the cooling water is lower than the certain temperature and the all-solid-state battery 21 may be cooled, the cooling water can be prevented from flowing through the all-solid-state battery 21.
As described above, in the drive unit according to the second embodiment, the upstream side of the all solid state battery 21 in the cooling circuit 130 is connected to the downstream side of the all solid state battery 21 in the cooling circuit 130 and the upstream side of the engine 3. And a thermostat 136 provided in the cooling circuit 130 and opened when the cooling water is at a certain temperature or higher. The thermostat 136 is provided between the all-solid-state battery 21 and the upstream side of the bypass passage 135. It is arranged in.

Therefore, when the cooling water is at or above a certain temperature, the thermostat 136 opens and the cooling water flows to the all-solid-state battery 21, while when the cooling water is below a certain temperature, the thermostat 136 closes and the cooling water flows to the all-solid-state battery 21. Since it does not circulate, the all-solid-state battery 21 can be prevented from being cooled by the cooling water until the temperature of the cooling water becomes equal to or higher than a certain temperature.
The description of the drive unit according to the present invention is finished above, but the present invention is not limited to the above embodiment, and can be changed without departing from the gist of the invention.

For example, in the present embodiment, the all-solid-state battery 21 including LiCoO 2 for the positive electrode, graphite for the negative electrode, and LGPS as the electrolyte has been described. However, the positive electrode, the negative electrode, and the electrolyte may be all solid, and the electrolyte may be used. LSSPS (for example, Li _10.35 [Sn _0.27 Si _1.08 ] P _1.65 S ₁₂ ) may be provided, and a so-called oxide type all solid state battery may be used for the all solid state battery 21.

Further, in the present embodiment, the description has been given using the thermostats 36 and 136. However, it is sufficient that the cooling water can flow through the radiator 29 and the all-solid-state battery 21 according to the temperature of the cooling water. .
Further, in the present embodiment, the description has been made using the cooling water for cooling the engine 3, but cooling water for cooling devices that generate heat during operation, such as the front motor 5 and the rear motor 7, may be used.

  Also, in the present embodiment, the description has been made using cooling water as the heat medium. However, instead of cooling water, engine oil circulating in the engine 3 is used, the radiator 29 is an oil cooler, the pump 31a is an oil pump, and the thermostat 36 may be replaced with a relief valve, respectively.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Drive unit 3 Engine (drive part)
5 Front motor (drive unit, motor)
7 Rear motor (drive unit, motor)
21 All-solid-state battery (secondary battery)
29 Radiator (cooling unit)
30, 130 Cooling circuit (heat medium circuit)
31 1st passage (low temperature heat medium passage)
32 Second passage (high-temperature heat medium passage)
33 Third passage (high temperature heat medium passage)
34 4th passage (high temperature heat medium passage)
35 bypass passage (first bypass passage)
36 Thermostat (first open / close valve)
135 bypass passage (second bypass passage)
136 Thermostat (second on-off valve)

Claims (4)

A drive unit mounted on the vehicle and generating heat during operation,
A cooling unit for cooling the driving unit;
A heat medium circuit that connects the drive unit and the cooling unit to allow a heat medium to flow therethrough,
A motor mounted on the vehicle to drive the vehicle,
A secondary battery that supplies power to the motor,
The heat medium circuit has a high-temperature heat medium passage that allows the heat medium to flow from the drive unit toward the cooling unit,
The secondary battery is an all-solid-state battery including a solid electrolyte containing lithium, and is a drive unit connected to the high-temperature heat medium passage.   The drive unit according to claim 1, wherein the drive unit is an internal combustion engine that operates by burning fuel. A first on-off valve that is provided in the heat medium circuit and opens when the heat medium is equal to or higher than a predetermined temperature;
A low-temperature heat medium passage that is provided in the heat medium circuit and allows the heat medium to flow from the cooling unit of the heat medium circuit toward the drive unit;
A first bypass passage extending from the high-temperature heat medium passage of the heat medium circuit, connected to the low-temperature heat medium passage, and flowing the heat medium from the high-temperature heat medium passage toward the low-temperature heat medium passage. ,
The first on-off valve is disposed between the secondary battery and the cooling unit in the high-temperature heat medium passage,
The drive unit according to claim 1, wherein the first bypass passage extends from the high-temperature heat medium passage between the secondary battery and the first on-off valve. A second bypass passage connecting the upstream side of the secondary battery in the heat medium circuit and the downstream side of the secondary battery in the heat medium circuit and the upstream side of the drive unit;
A second on-off valve that is provided in the heat medium circuit and opens when the heat medium is at or above a certain temperature,
4. The drive unit according to claim 1, wherein the second on-off valve is provided in the heat medium circuit between the secondary battery and an upstream side of the second bypass passage. 5.

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