# US 10,865,856 B2 · Control apparatus for vehicle drive-force transmitting apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,856 B2 - Document ID: US10865856B2 - Status: Granted - Kind: B2 - Application number: 16/535,512 - Filed: 2019-08-08 - Published: 2020-03-19 - Granted: 2020-12-15 - Earliest claimed: 2018-09-18 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Kentaroh Okada - Web page: https://patentgrep.com/patent/US10865856B2 ## CPC - B60L 15/2054: {by controlling transmissions or clutches} - F16H 3/78: Special adaptation of synchronisation mechanisms to these gearings - B60W 10/02: including control of driveline clutches - B60W 10/115: with planetary gears - F16H 37/022: {the toothed gearing having orbital motion} - F16H 61/0437: {by using electrical signals (F16H61/0403 and F16H61/061 take precedence)} - B60L 15/2018: {for braking on a slope} - B60L 2240/12: Speed - B60L 2240/485: Temperature - B60L 2240/486: Operating parameters - B60L 2240/507: Operating parameters - B60W 30/1843: {Overheating of driveline components (B60W30/186 takes precedence)} - B60W 30/19: Improvement of gear change, e.g. by synchronisation or smoothing gear shift - B60W 2510/0291: Clutch temperature - B60W 2510/107: Temperature - B60W 2520/10: Longitudinal speed - B60W 2710/021: Clutch engagement state - F16H 57/0478: {Synchromesh devices} - F16H 2003/0811: {using unsynchronised clutches} - F16H 2037/026: {Layouts with particular features of reversing gear, e.g. to achieve compact arrangement} - F16H 2059/725: {Sensing or calculating temperature of oil in friction devices, e.g. wet clutches, to prevent overheating of friction linings} - F16H 2061/0474: {by smoothing engagement or release of positive clutches; Methods or means for shock free engagement of dog clutches} - F16H 2061/163: {Holding the gear for delaying gear shifts under unfavorable conditions, e.g. during cornering} - Y02T 10/64: Electric machine technologies in electromobility - Y02T 10/72: Electric energy management in electromobility - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - F16H: GEARING - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A control apparatus for a drive-force transmitting apparatus that defines a first drive-force transmitting path that is to be established by engagements of a first frictional engagement device and a dog clutch and a second drive-force transmitting path in which a lower gear ratio is provided than in the first drive-force transmitting path. In a second running mode with the second drive-force transmitting path being established, the control apparatus places the dog clutch in a released state when a vehicle running speed is higher than a first speed value, and places the dog clutch in an engaged state when the running speed is not higher than the first speed value. Further, in the second running mode, the control apparatus inhibits the dog clutch from being switched to the released state when an accumulated heat quantity in a synchromesh mechanism of the dog clutch is larger than a first quantity value. ## Claims ### Claim 1 A control apparatus for a drive-force transmitting apparatus that is to be provided in a vehicle having a drive force source and drive wheels, wherein the drive-force transmitting apparatus includes: an input rotary member to which a drive force of the drive force source is to be transmitted; an output rotary member through which the drive force is to be transmitted to the drive wheels; a gear mechanism configured to provide at least one gear ratio; a continuously-variable transmission mechanism configured to provide a continuously-variable gear ratio that is lower than the at least one gear ratio of the gear mechanism; a first frictional engagement device; a second frictional engagement device; and a dog clutch that is provided with a synchromesh mechanism, wherein the drive-force transmitting apparatus defines a plurality of drive-force transmitting paths that are provided in parallel with each other between the input rotary member and the output rotary member, wherein the plurality of drive-force transmitting paths include a first drive-force transmitting path that is to be established by engagements of the first frictional engagement device and the dog clutch, such that the drive force is to be transmitted from the input rotary member to the output rotary member through the gear mechanism along the first drive-force transmitting path when the first drive-force transmitting path is established, wherein the plurality of drive-force transmitting paths include a second drive-force transmitting path that is to be established by engagement of the second frictional engagement device, such that the drive force is to be transmitted from the input rotary member to the output rotary member through the continuously-variable transmission mechanism along the second drive-force transmitting path when the second drive-force transmitting path is established, and wherein said control apparatus comprises: a transmission-shifting control portion configured, during running of the vehicle in a second running mode in which the vehicle is to run with the driving force being transmitted through the continuously-variable transmission mechanism along the second drive-force transmitting path, to place the dog clutch in a released state when a running speed of the vehicle is higher than a first speed value, and to place the dog clutch in an engaged state when the running speed of the vehicle is not higher than the first speed value; an accumulated-heat-quantity calculating portion configured, when the dog clutch is placed in the engaged state during the running of the vehicle in the second running mode, to calculate an accumulated heat quantity that is a quantity of heat accumulated in the synchromesh mechanism; and a synchronization-operation limiting portion configured, during the running of the vehicle in the second running mode, to inhibit the dog clutch from being switched from the engaged state to the released state when the accumulated heat quantity in the synchromesh mechanism is larger than a first quantity value, and to allow the dog clutch to be switched from the engaged state to the released state when the accumulated heat quantity in the synchromesh mechanism is not larger than the first quantity value. ### Claim 2 (depends on 1) The control apparatus according to claim 1, wherein, during inhibition of switching of the dog clutch from the engaged state to the released state, said synchronization-operation limiting portion is configured, when the accumulated heat quantity in the synchromesh mechanism is not smaller than a second quantity value that is smaller than the first quantity value, to keep inhibiting the dog clutch from being switched from the engaged state to the released state, and is configured, when the accumulated heat quantity in the synchromesh mechanism is smaller than the second quantity value, to allow the dog clutch to be switched from the engaged state to the released state. ### Claim 3 (depends on 1) The control apparatus according to claim 1, wherein said synchronization-operation limiting portion is configured, when the running speed of the vehicle is not lower than a second speed value that is higher than the first speed value, to allow the dog clutch to be switched from the engaged state to the released state, irrespective of whether the accumulated heat quantity in the synchromesh mechanism is larger than the first quantity value or not. ### Claim 4 (depends on 3) The control apparatus according to claim 3, wherein the second speed value is a lower limit value of a running speed range in which the vehicle is inhibited from being switched from the second running mode to a first running mode in which the vehicle is to run with the driving force being transmitted through the gear mechanism along the first drive-force transmitting path. ### Claim 5 (depends on 1) The control apparatus according to claim 1, wherein said accumulated-heat-quantity calculating portion is configured to calculate the accumulated heat quantity in the synchromesh mechanism, based on a generated heat quantity and a dissipated heat quantity, wherein the generated heat quantity is a quantity of heat generated in the synchromesh mechanism in process of switching of the dog clutch from the released state to the engaged state, and wherein the dissipated heat quantity is a quantity of heat dissipated from the synchromesh mechanism, and is dependent on a length of time for which the dog clutch is held in the engaged state. ### Claim 6 (depends on 2) The control apparatus according to claim 2, wherein said synchronization-operation limiting portion is configured, when the running speed of the vehicle is not lower than a second speed value that is higher than the first speed value, to allow the dog clutch to be switched from the engaged state to the released state, irrespective of whether the accumulated heat quantity in the synchromesh mechanism is larger than the second quantity value or not. ### Claim 7 (depends on 1) The control apparatus according to claim 1, wherein said accumulated-heat-quantity calculating portion is configured to calculate the accumulated heat quantity in the synchromesh mechanism, such that the calculated accumulated heat quantity is a heat quantity value that is obtained by subtracting a dissipated heat quantity from a generated heat quantity, wherein the generated heat quantity is a quantity of heat generated in the synchromesh mechanism in process of switching of the dog clutch from the released state to the engaged state, and wherein the dissipated heat quantity is a quantity of heat dissipated from the synchromesh mechanism, and is increased with increase of a length of time for which the dog clutch is held in the engaged state. ### Claim 8 (depends on 1) The control apparatus according to claim 1, wherein said synchronization-operation limiting portion is configured, when the accumulated heat quantity in the synchromesh mechanism is larger than the first quantity value during the running of the vehicle in the second running mode, to inhibit the dog clutch from being switched from the engaged state to the released state, irrespective of whether the running speed of the vehicle is higher than the first speed value, and wherein said synchronization-operation limiting portion is configured, when the accumulated heat quantity in the synchromesh mechanism is not larger than the first quantity value during the running of the vehicle in the second running mode, to allow the dog clutch to be switched from the engaged state to the released state, as long as the running speed of the vehicle is higher than the first speed value.