# US 2020/0132012 A1 · Solenoid valve drive control circuit, solenoid valve drive device, and fuel injection apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0132012 A1 - Document ID: US20200132012A1 - Status: Published application - Kind: A1 - Application number: 16/726,080 - Filed: 2019-12-23 - Published: 2020-04-30 - Earliest claimed: 2017-06-29 - Assignees: Panasonic Intellectual Property Management Co., Ltd.; Kelhin Corporation - Applicants: Panasonic Intellectual Property Management Co., Ltd.; Kelhin Corporation - Inventors: Keisuke KURODA; Makoto KAWAJIRI; Ken MARUYAMA; Takashi RYU; Atsushi OGAWA; Motoaki KATO; Kengo NOMURA - Web page: https://patentgrep.com/patent/US20200132012A1 ## CPC - F02D 41/20: Output circuits, e.g. for controlling currents in command coils - F02D 41/3005: {Details not otherwise provided for} - F02D 45/00: Electrical control not provided for in groups F02D41/00 - F02D43/00 - F02M 51/061: {using electromagnetic operating means} - F16K 31/06: using a magnet {, e.g. diaphragm valves, cutting off by means of a liquid} - F16K 37/00: Special means in or on valves or other cut-off apparatus for indicating or recording operation thereof, or for enabling an alarm to be given - H01F 7/18: Circuit arrangements for obtaining desired operating characteristics, e.g. for slow operation, for sequential energisation of windings, for high-speed energisation of windings - F02D 2041/2003: {using means for creating a boost voltage, i.e. generation or use of a voltage higher than the battery voltage, e.g. to speed up injector opening} - F02D 2041/2055: {with means for determining actual opening or closing time} - F02D 2041/2058: {using information of the actual current value} - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES ## Abstract A solenoid valve drive control circuit includes: a timing generator circuit that outputs a timing signal for controlling a driver circuit, in accordance with a solenoid valve opening and closing instruction signal; and a valve closing detector circuit that detects a valve closing timing after the timing generator circuit outputs the timing signal for instructing a solenoid valve to close, by monitoring a solenoid valve outflow terminal voltage in the solenoid valve as a signal voltage. The valve closing detector circuit includes a measurement circuit that (i) detects each timing signal reaching a threshold voltage sequentially outputted from a threshold voltage selector circuit, and (ii) outputs a signal indicating the valve closing timing when a change in a measurement value that is obtained through measurement of a time interval of each timing satisfies a predetermined condition. ## Claims ### Claim 1 A solenoid valve drive control circuit that controls a driver circuit including a switching element that causes a current to flow to a solenoid valve, the solenoid valve drive control circuit comprising: a timing generator circuit that generates and outputs a timing signal for causing the switching element to be turned on and off, in accordance with a control signal inputted from outside for instructing the solenoid valve to open and close; and a valve closing detector circuit that detects a valve closing timing after the timing generator circuit outputs the timing signal for instructing the solenoid valve to close, by monitoring a signal voltage that is determined depending on a voltage in at least one of two terminals included in the solenoid valve for causing the current to flow, the valve closing timing being a timing at which the solenoid valve closes, wherein the valve closing detector circuit includes: a threshold voltage selector circuit that sequentially selects and outputs a threshold voltage from a plurality of threshold voltages; a comparator that compares the threshold voltage sequentially outputted from the threshold voltage selector circuit with the signal voltage; and a measurement circuit that (i) detects, based on an output from the comparator, each timing of the signal voltage reaching the threshold voltage sequentially outputted from the threshold voltage selector circuit, and (ii) outputs a signal indicating the valve closing timing when a change in a measurement value that is obtained through measurement of a time interval of each timing satisfies a predetermined condition. ### Claim 2 (depends on 1) The solenoid valve drive control circuit according to claim 1, wherein when outputting the timing signal for instructing the solenoid valve to close, the timing generator circuit outputs the timing signal so that one of the two terminals becomes a ground potential or an optional fixed potential, and the valve closing detector circuit monitors a voltage in an other of the two terminals as the signal voltage. ### Claim 3 (depends on 1) The solenoid valve drive control circuit according to claim 1, wherein the valve closing detector circuit further includes a differential amplifier that detects, as the signal voltage, a difference between a voltage in one of the two terminals and a voltage in an other of the two terminals. ### Claim 4 (depends on 1) The solenoid valve drive control circuit according to claim 1, wherein the predetermined condition is a difference between a current measurement value obtained through the measurement and a past measurement value obtained at least n measurements ago being greater than an optional set time, where n is an integer of at least 1. ### Claim 5 (depends on 4) The solenoid valve drive control circuit according to claim 4, wherein the past measurement value is selected from a plurality of past measurement values obtained through different measurements. ### Claim 6 (depends on 5) The solenoid valve drive control circuit according to claim 5, wherein the past measurement value is a greater one of (i) a first-preceding measurement value obtained one measurement before the measurement of the current measurement value and (ii) a second-preceding measurement value obtained two measurements before the measurement of the current measurement value. ### Claim 7 (depends on 1) The solenoid valve drive control circuit according to claim 1, wherein the threshold voltage selector circuit changes an order of sequentially selecting the threshold voltage from the plurality of threshold voltages, in accordance with a control signal inputted from outside for instructing a switching interval of the threshold voltage. ### Claim 8 (depends on 1) A solenoid valve drive device, comprising: a driver circuit including a switching element that causes a current to flow to a solenoid valve; and the solenoid valve drive control circuit according to claim 1 that controls the driver circuit. ### Claim 9 (depends on 8) A fuel injection apparatus, comprising: a solenoid valve for injecting fuel into an engine of transportation equipment; and the solenoid valve drive device according to claim 8 that performs drive control of the solenoid valve.