# US 10,479,341 B2 · Electrically powered brake device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,479,341 B2 - Document ID: US10479341B2 - Status: Granted - Kind: B2 - Application number: 15/817,595 - Filed: 2017-11-20 - Published: 2018-03-15 - Granted: 2019-11-19 - Earliest claimed: 2015-05-22 - Assignees: Ntn Corporation - Applicants: Ntn Corporation - Inventors: Yui Masuda - Web page: https://patentgrep.com/patent/US10479341B2 ## CPC - B60T 7/042: {by electrical means, e.g. using travel or force sensors} - B60T 17/221: {Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems (hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M)} - B60T 8/17: Using electrical or electronic regulation means to control braking {(detecting or indicating faulty operation B60T8/885)} - B60T 8/171: Detecting parameters used in the regulation; Measuring values used in the regulation - B60T 8/409: {characterised by details of the stroke simulating device} - B60T 13/146: {Part of the system directly actuated by booster pressure} - B60T 13/662: {characterised by specified functions of the control system components} - B60T 13/686: {in hydraulic systems or parts thereof} - B60T 13/74: with electrical assistance or drive - B60T 13/741: {acting on an ultimate actuator} - F16D 65/18: adapted for drawing members together {, e.g. for disc brakes} - F16D 66/00: Arrangements for monitoring working conditions, e.g. wear, temperature - H02K 7/102: with friction brakes - H02K 7/14: Structural association with mechanical loads, e.g. with hand-held machine tools or fans (with fan or impeller for cooling the machine H02K9/06) - H02P 3/00: Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters (stopping of synchronous motors with electronic commutators H02P6/24; stopping dynamo-electric motors rotating step by step H02P8/24; vector control H02P21/00) - H02P 6/08: Arrangements for controlling the speed or torque of a single motor (H02P6/10, H02P6/28 take precedence) - H02P 7/06: for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current - H02P 29/64: Controlling or determining the temperature of the winding - B60T 2250/04: Vehicle reference speed; Vehicle body speed - F16D 2066/001: {Temperature} - F16D 2066/005: {Force, torque, stress or strain} - F16D 2066/006: {without direct measurement of the quantity monitored, e.g. wear or temperature calculated form force and duration of braking} - F16D 2121/24: using motors - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract This electric brake device includes: a brake rotor; a friction member; friction member operator configured to bring the friction member into contact with the brake rotor; an electric motor configured to drive the friction member operator; and a controller configured to control a braking force by means of the electric motor. The controller includes: heat balance degree estimator configured to estimate a balance degree among heat generation amounts of a plurality of exciting coils in the electric motor; and heat load balancing section configured to decrease a heat generation amount of a specific exciting coil when the heat balance degree estimator has estimated that the heat generation amount of the specific exciting coil among the plurality of exciting coils is larger than heat generation amounts of the other exciting coils. ## Claims ### Claim 1 An electric brake device comprising: a brake rotor; a friction member configured to be brought into contact with the brake rotor; a friction member operator configured to bring the friction member into contact with the brake rotor; an electric motor configured to drive the friction member operator; and a controller configured to control a braking force by means of the electric motor, wherein the controller includes: a heat balance degree estimator configured to estimate a balance degree among heat generation amounts of a plurality of exciting coils in the electric motor; and a heat load balancing section configured to decrease a heat generation amount of a specific exciting coil, when the heat balance degree estimator has estimated that the heat generation amount of the specific exciting coil among the plurality of exciting coils is larger than heat generation amounts of the other exciting coils, to equalize the heat generation amounts of the respective exciting coils. ### Claim 2 (depends on 1) The electric brake device as claimed in claim 1, wherein the heat balance degree estimator estimates the balance degree among the heat generation amounts of the respective exciting coils on the basis of an integrated value of a value proportional to a square of an estimated value of a current in each exciting coil. ### Claim 3 (depends on 2) The electric brake device as claimed in claim 2, wherein when the heat balance degree estimator has determined that a value of either one of or both of: a difference between the integrated value in a determined exciting coil and the integrated values of the other exciting coils; and a ratio of the differences has exceeded a threshold, the heat load balancing section decreases the heat generation amount of the specific exciting coil. ### Claim 4 An electric brake device comprising: a brake rotor; a friction member configured to be brought into contact with the brake rotor; a friction member operator configured to bring the friction member into contact with the brake rotor; an electric motor configured to drive the friction member operator a controller configured to control a braking force by means of the electric motor; and a braking force estimator configured to determine an estimated value of a braking force that occurs by the friction member being pressed against the brake rotor, wherein the controller includes: a heat balance degree estimator configured to estimate a balance degree among heat generation amounts of a plurality of exciting coils in the electric motor; a heat load balancing section configured to decrease a heat generation amount of a specific exciting coil, when the heat balance degree estimator has estimated that the heat generation amount of the specific exciting coil among the plurality of exciting coils is larger than heat generation amounts of the other exciting coils; and an allowable error setting section configured to set an allowable error that is to be used in follow-up control performed on the braking force with respect to a target braking force, and the heat load balancing section causes the braking force to be varied so as to realize an energization phase in which an absolute value of a current of the specific exciting coil becomes smaller than an original value thereof within a range of the allowable error set by the allowable error setting section. ### Claim 5 (depends on 4) The electric brake device as claimed in claim 4, wherein the allowable error setting section causes the allowable error to be varied such that the larger the target braking force or the braking force is, the larger the allowable error becomes. ### Claim 6 (depends on 4) The electric brake device as claimed in claim 4, wherein the controller includes a vehicle speed information obtaining section configured to obtain information of vehicle speed of a vehicle to which the electric brake device is mounted, and the allowable error setting section causes the allowable error to be varied such that the lower the vehicle speed obtained by the vehicle speed information obtaining section is, the larger the allowable error becomes.