A decompression shaft (56) of a decompression device (50) includes an engagement pin (53) that is guided by a guide groove (51a) formed in a decompression weight (51), a decompression cam (54) that is provided on one cam surface of an intake valve cam (25c) and an exhaust valve cam (25b) so as to advance and retreat, and a connection portion (55) that connects the engagement pin (53) and the decompression cam (54). The decompression weight (51) is formed with a rotation restricting groove (51e) that restricts rotation of the decompression shaft (56) when a force acts in a direction in which the decompression cam (54) moves on the decompression shaft (56) from an advanced position to a retracted position when an engine (E) is stopped and that is continuous with the guide groove (51a).

An exemplary embodiment of the present disclosure relates to a construction machine starting assist system including: an engine of a construction machine; an input unit which receives a key-on signal and a key-off signal of the engine; a hydraulic pump which is operated by the engine; an actuator which is operated by hydraulic oil discharged from the hydraulic pump; a regeneration valve which is switched so that a part or an entirety of the hydraulic oil returned from the actuator; an accumulator which is charged with the hydraulic oil supplied from the regeneration valve; a charging valve which is controlled so that the hydraulic oil is discharged from the accumulator when the key-on signal is inputted into the input unit; and a hydraulic motor connected to the engine and configured to assist in starting the engine.

An exemplary embodiment of the present disclosure relates to a construction machine starting assist system including: an engine of a construction machine; an input unit which receives a key-on signal and a key-off signal of the engine; a hydraulic pump which is operated by the engine; an actuator which is operated by hydraulic oil discharged from the hydraulic pump; a regeneration valve which is switched so that a part or an entirety of the hydraulic oil returned from the actuator; an accumulator which is charged with the hydraulic oil supplied from the regeneration valve; a charging valve which is controlled so that the hydraulic oil is discharged from the accumulator when the key-on signal is inputted into the input unit; and a hydraulic motor connected to the engine and configured to assist in starting the engine.

A control device for an internal combustion engine includes an electronic control unit configured to determine whether or not cylinder-specific air-fuel ratio processing is being executed in which an air-fuel ratio of at least one of a plurality of cylinders is controlled to be a rich air-fuel ratio and an air-fuel ratio of at least one of the other cylinders is controlled to be a lean air-fuel ratio. The electronic control unit updates a first learning value in which a result of comparison between a knock strength of the internal combustion engine and a first determination value is reflected when the cylinder-specific air-fuel ratio processing is not being executed. The electronic control unit prohibits updating of the first learning value and calculates a target ignition timing of the internal combustion engine based on the first learning value when the cylinder-specific air-fuel ratio processing is being executed.

A control device for an internal combustion engine includes an electronic control unit configured to determine whether or not cylinder-specific air-fuel ratio processing is being executed in which an air-fuel ratio of at least one of a plurality of cylinders is controlled to be a rich air-fuel ratio and an air-fuel ratio of at least one of the other cylinders is controlled to be a lean air-fuel ratio. The electronic control unit updates a first learning value in which a result of comparison between a knock strength of the internal combustion engine and a first determination value is reflected when the cylinder-specific air-fuel ratio processing is not being executed. The electronic control unit prohibits updating of the first learning value and calculates a target ignition timing of the internal combustion engine based on the first learning value when the cylinder-specific air-fuel ratio processing is being executed.

A control device for an internal combustion engine includes an electronic control unit configured to determine whether or not cylinder-specific air-fuel ratio processing is being executed in which an air-fuel ratio of at least one of a plurality of cylinders is controlled to be a rich air-fuel ratio and an air-fuel ratio of at least one of the other cylinders is controlled to be a lean air-fuel ratio. The electronic control unit updates a first learning value in which a result of comparison between a knock strength of the internal combustion engine and a first determination value is reflected when the cylinder-specific air-fuel ratio processing is not being executed. The electronic control unit prohibits updating of the first learning value and calculates a target ignition timing of the internal combustion engine based on the first learning value when the cylinder-specific air-fuel ratio processing is being executed.

An exemplary embodiment of the present disclosure relates to a construction machine starting assist system including: an engine of a construction machine; an input unit which receives a key-on signal and a key-off signal of the engine; a hydraulic pump which is operated by the engine; an actuator which is operated by hydraulic oil discharged from the hydraulic pump; a regeneration valve which is switched so that a part or an entirety of the hydraulic oil returned from the actuator and a part or an entirety of the hydraulic oil discharged from the hydraulic pump are supplied for regeneration; an accumulator which is charged with the hydraulic oil supplied from the regeneration valve; a charging valve which is controlled so that the hydraulic oil is discharged from the accumulator when the key-on signal is inputted into the input unit; and a hydraulic motor which is operated by the hydraulic oil discharged from the charging valve, in which the hydraulic motor is connected to the engine and assists in starting the engine.

A system includes a controller coupled to an aftertreatment system. The controller is configured to identify a request for a regeneration process associated with a component of the aftertreatment system based on receiving an input at an operator input device or receiving, from a sensor, data regarding the aftertreatment system. The controller is configured to receive, from a memory device, a latch status. The controller is configured to receive, from the memory device, a time value responsive to the latch status being a first latch status. The controller is configured to modify the latch status to a second latch status responsive to the time value being at or above a threshold such that the regeneration process is enabled. The controller is configured to prevent the regeneration process responsive to the time value being below the threshold.

A system includes a controller coupled to an aftertreatment system. The controller is configured to identify a request for a regeneration process associated with a component of the aftertreatment system based on receiving an input at an operator input device or receiving, from a sensor, data regarding the aftertreatment system. The controller is configured to receive, from a memory device, a latch status. The controller is configured to receive, from the memory device, a time value responsive to the latch status being a first latch status. The controller is configured to modify the latch status to a second latch status responsive to the time value being at or above a threshold such that the regeneration process is enabled. The controller is configured to prevent the regeneration process responsive to the time value being below the threshold.