A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.

A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.

An injection control device includes: a booster circuit that boosts a battery voltage; a boosting control unit that performs boosting control on the booster circuit; a charge control setting unit that sets a charge prohibition time of the booster circuit for the boosting control unit; and a maximum time specification unit that specifies a maximum valve-closing detection time based on a valve-closing detection time.

A controller for an internal combustion engine including a fuel pressure control processor that controls a fuel pressure at a target fuel pressure, an instruction value calculating processor that calculates a peak instruction value, an upper limit guard processor that executes a guard process on the peak instruction value, an energizing processor that energizes the coil based on the peak instruction value that has undergone the guard process, a convergence determination processor that determines whether or not the detected fuel pressure has converged on the target fuel pressure, and a decreasing processor that decreases the upper limit guard value to a lower value when the fuel pressure has converged on the target fuel pressure than when the fuel pressure has not converged on the target fuel pressure.

An auxiliary-machine control device equipped with: a command-value acquisition unit for acquiring an operation command value for a device to be controlled and an allowable range for the operation amount of control means for controlling the operating state of the device to be controlled; an operation-amount calculation unit for calculating the operation amount for the control means on the basis of the acquired operation command value; and an operation-amount determination unit for outputting the calculated operation-amount signal to the device to be controlled if the operation amount calculated by the operation-amount calculation unit falls within the allowable range, and outputting an upper-limit value or a lower-limit value for the operation-amount allowable range if the calculated operation amount falls outside of the allowable range.

An electromagnetic valve drive device which supplies a hold current with a prescribed fluctuation range to an electromagnetic coil of an electromagnetic valve after a current peak when a supply of electricity starts has passed includes: a power supplier which intermittently applies a drive voltage to the electromagnetic coil; a detector which detects the hold current; a first comparator which compares a detected current by the detector with a first threshold value; a filter which performs integration processing on an output of the first comparator; a second comparator which compares an output of the filter with a second threshold value to generate an output signal used for generating a control signal for controlling the power supplier; and a control signal generator which generates the control signal for controlling the power supplier based on the output signal of the second comparator, wherein the filter is a count-up/down type digital filter.

An injection control device includes: an area correction unit that calculates an energization time correction amount by performing area correction of a current flowing through a fuel injection valve when executing a current drive of a fuel injection valve to inject a fuel from the fuel injection valve in a multi-stage injection; and a change unit that changes an upper limit guard value of the energization time correction amount according to an injection time of the multi-stage injection during control of the multi-stage injection.

A control device includes a plurality of sound reducing parts that is operated individually, when a predetermined condition for operation is met, at each of a plurality of timings when an operating sound is generated as a result of a movement of a valve body, in one open-and-close period, and that reduces the operating sound, at each of the plurality of the timings, by changing a period of energizing an electromagnetic part to an increase side relative to a normal time, an upper limit determination part that determines whether a required period of energizing the electromagnetic part in the one open-and-close period exceeds a predetermined upper limit value, when all the plurality of the sound reducing parts are operated, and a selectively operating part that selects and operates one or more of the plurality of the sound reducing parts to an extent that the required period of energizing does not exceed the upper limit value, when the upper limit determination part has determined that the required period of energizing exceeds the upper limit value.

A current control unit in a fuel injection device controls a magnitude of a current flowing through a coil during single energization. A current Ip1 flows once a signal input to the current control unit is turned ON at time t11. As a result, a movable core and a needle abut against each other with a lift amount increased at time t12, and then the needle is separated from a valve seat and pre-injection is performed. At time t13, which follows the pre-injection, the needle and movable core lift amount becomes a lift amount D1 at a time when the needle and the valve seat abut against each other, and temporary valve closing occurs. At time t14, which follows time t13, currents Ix1 and Im1 larger than the current Ip1 are caused to flow through the coil, and then main injection is performed with the needle and movable core lift amount turned into a lift amount D2 larger than the lift amount D1. Therefore, fuel injection can be performed twice during the single energization.

An injection control device includes: an area correction unit that calculates an energization time correction amount by performing area correction of a current flowing through a fuel injection valve when executing a current drive of a fuel injection valve to inject a fuel from the fuel injection valve in a multi-stage injection; and a change unit that changes an upper limit guard value of the energization time correction amount according to an injection time of the multi-stage injection during control of the multi-stage injection.