# US 10,870,424 B2 · Hybrid vehicle drive system

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- Number: US 10,870,424 B2
- Document ID: US10870424B2
- Status: Granted
- Kind: B2
- Application number: 16/353,924
- Filed: 2019-03-14
- Published: 2019-09-26
- Granted: 2020-12-22
- Earliest claimed: 2018-03-23
- Assignees: Honda Motor Co., Ltd.
- Applicants: Honda Motor Co., Ltd.
- Inventors: Takahiro Kasahara
- Web page: https://patentgrep.com/patent/US10870424B2

## CPC

- B60K 6/445: Differential gearing distribution type
- B60W 20/13: in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
- B60K 6/365: with the gears having orbital motion
- B60K 6/383: One-way clutches or freewheel devices
- B60K 6/387: Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
- B60K 6/442: Series-parallel switching type
- B60W 10/02: including control of driveline clutches
- B60W 10/06: including control of combustion engines
- B60W 10/08: including control of electric propulsion units, e.g. motors or generators
- B60W 10/115: with planetary gears
- B60W 20/20: Control strategies involving selection of hybrid configuration, e.g. selection between series or parallel configuration
- B60K 2006/381: {characterized by driveline brakes}
- B60W 2510/0291: Clutch temperature
- B60W 2510/244: Charge state
- B60W 2520/10: Longitudinal speed
- B60W 2710/021: Clutch engagement state
- B60W 2710/0644: Engine speed
- B60W 2710/081: Speed
- B60W 2710/1005: Transmission ratio engaged
- B60Y 2200/92: Hybrid vehicles
- Y02T 10/62: Hybrid vehicles
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A drive system of a hybrid vehicle including an internal combustion engine, a first motor-generator, a first power transmission path and a second power transmission path, a power division mechanism, a second motor-generator, a clutch portion provided at the power transmission path to make or break the first power transmission path, and a microprocessor. The microprocessor is configured to determine whether a drive in a region exceeding a characteristic curve of a driving force defined by a sum of a driving force output through the first power transmission path and a driving force of the second motor-generator at a low vehicle speed is necessary, and to control the clutch portion to a half-clutch state when determining that the drive in the region is necessary, while connecting or disconnecting the clutch portion when determining that the drive in the region is not necessary.

## Claims

### Claim 1

A drive system of a hybrid vehicle, comprising:
an internal combustion engine;
a first motor-generator;
a power transmission path including a first power transmission path and a second power transmission path connected with each other in series;
a power division mechanism connected to the internal combustion engine to divide a power generated by the internal combustion engine to the first motor-generator and the first power transmission path;
a second motor-generator connected to the second power transmission path;
a clutch portion including friction elements engageable and disengageable with each other to connect or disconnect so as to make or break the first power transmission path in accordance with an engagement and an disengagement of the friction elements; and
an electronic control unit including a microprocessor and a memory and configured to perform controlling the internal combustion engine, the first motor-generator, the second motor-generator and the clutch portion, wherein
the microprocessor is configured to perform determining whether a drive in a region exceeding a characteristic curve of a driving force defined by a sum of a driving force output through the first power transmission path and a driving force of the second motor-generator at a range of a vehicle speed smaller than or equal to a predetermined vehicle speed is necessary, and
the controlling including controlling the clutch portion to a half-clutch state when determining that the drive in the region is necessary, while connecting or disconnecting the clutch portion when determining that the drive in the region is not necessary.

### Claim 2 (depends on 1)

The drive system according to claim 1, further comprising
a state of charge detector configured to detect a state of charge of a rechargeable battery supplying an electrical power to the first motor-generator and the second motor-generator, wherein
the microprocessor is configured to perform
the controlling including controlling the clutch portion to the half-clutch state when determining that the drive in the region is necessary and the state of charge detected by the state of charge detector is less than a predetermined value, while connecting the clutch portion so that a torque of the first motor-generator is transmitted to the second power transmission path through the first power transmission path when the state of charge detected by the state of charge detector is greater than or equal to the predetermined value, even if determining that the drive in the region is necessary.

### Claim 3 (depends on 2)

The drive system according to claim 2, further comprising:
a one-way clutch interposed between an output shaft in the first power transmission path and an input shaft in the second power transmission path so that the output shaft and the input shaft integrally rotate in a locked state and the input shaft rotates relative to the output shaft in an unlocked state; and
a mode change mechanism provided in the first power transmission path to change a drive mode, wherein
the power division mechanism includes a first planetary gear mechanism having a first sun gear connected to the first motor-generator, a first carrier connected to the internal combustion engine, and a first ring gear,
the mode change mechanism includes the clutch portion and a second planetary gear mechanism having a second sun gear connected to the output shaft, a second carrier connected to the first ring gear, and a second ring gear,
the clutch portion is configured to connect or disconnect the second sun gear and the second ring gear, and
the microprocessor is configured to perform
the controlling including controlling the clutch portion to the half-clutch state and controlling the internal combustion engine and the first motor-generator so as to increase a rotational speed of the first motor-generator when determining that the drive in the region is necessary and the state of charge detected by the state of charge detector is less than the predetermined value.

### Claim 4 (depends on 3)

The drive system according to claim 3, wherein
the mode change mechanism further includes a brake portion configured to brake or non-brake the second ring gear,
the microprocessor is further configured to perform controlling the brake portion, and
the microprocessor is configured to perform
the controlling including controlling the brake portion so as to non-brake the second ring gear and disconnecting the clutch portion when the drive mode is changed to an EV mode in which the hybrid vehicle is driven by a power of the second motor-generator with the internal combustion engine stopped, while controlling the brake portion so as to brake the second ring gear and disconnecting the clutch portion or controlling the brake portion so as to non-brake the second ring gear and connecting the clutch portion when the drive mode is changed to a HV mode in which the hybrid vehicle is driven by the power of the second motor-generator and the power generated by the internal combustion engine.

### Claim 5 (depends on 2)

The drive system according to claim 2, wherein
the microprocessor is configured to perform
the controlling including controlling the first motor-generator and the second motor-generator so that the first motor-generator functions as a generator and the second motor-generator functions as a motor when determining that the drive in the region is necessary and the state of charge detected by the state of charge detector is less than the predetermined value, while controlling the first motor-generator and the second motor-generator so that the first motor-generator functions as a motor and the second motor-generator functions as the motor when determining that the drive in the region is necessary and the state of charge detected by the state of charge detector is greater than or equal to the predetermined value.

### Claim 6 (depends on 1)

The drive system according to claim 1, further comprising
a temperature detector configured to detect a temperature of the clutch portion, wherein
the microprocessor is configured to perform
the controlling including controlling the internal combustion engine, the first motor-generator, the second motor-generator and the clutch portion in accordance with a first required driving force characteristic when the temperature detected by the temperature detector is less than a predetermined value, while controlling the internal combustion engine, the first motor-generator, the second motor-generator and the clutch portion in accordance with a second required driving force characteristic shifted to a high driving force side than the first required driving force characteristic when the temperature detected by the temperature detector is greater than or equal to the predetermined value.

### Claim 7 (depends on 1)

The drive system according to claim 1, wherein
the characteristic curve is set so that the driving force gradually increases to a predetermined driving force along with an increase of a vehicle speed from 0 to the predetermined vehicle speed, and
the region is defined by the characteristic curve, the predetermined driving force and the predetermined vehicle speed.

### Claim 8

A drive method of a hybrid vehicle, the hybrid vehicle including: an internal combustion engine; a first motor-generator; a power transmission path including a first power transmission path and a second power transmission path connected with each other in series; a power division mechanism connected to the internal combustion engine to divide a power generated by the internal combustion engine to the first motor-generator and the first power transmission path; a second motor-generator connected to the second power transmission path; and a clutch portion including friction elements engageable and disengageable with each other to connect or disconnect so as to make or break the first power transmission path in accordance with an engagement and an disengagement of the friction elements,
the drive method comprising:
controlling the internal combustion engine, the first motor-generator, the second motor-generator and the clutch portion; and
determining whether a drive in a region exceeding a characteristic curve of a driving force defined by a sum of a driving force output through the first power transmission path and a driving force of the second motor-generator at a range of a vehicle speed smaller than or equal to a predetermined vehicle speed is necessary, wherein
the controlling includes controlling the clutch portion to a half-clutch state when determining that the drive in the region is necessary, while connecting or disconnecting the clutch portion when determining that the drive in the region is not necessary.