A pressure sensor which detects a combustion pressure of an engine includes: a contact part which is in direct or indirect contact with a casing of the engine when the pressure sensor is attached to the engine; and a pressure detection unit which detects the combustion pressure and outputs a signal corresponding to the combustion pressure, wherein the pressure detection unit includes a pressure detection element which detects the combustion pressure and outputs a signal, and a circuit unit which converts the signal obtained from the pressure detection element into a signal corresponding to the combustion pressure, and the pressure detection unit is provided at a location positioned more inside the engine than the contact part when the pressure sensor is attached to the engine.

A remaining fuel amount warning device for a vehicle, the remaining fuel amount warning device giving a warning that an amount of fuel remaining in a fuel tank is smaller than a predetermined value on the basis of output of a fuel gauge measuring the remaining fuel amount, includes combustion state changing device for changing the combustion state of an engine. When the remaining fuel amount becomes smaller than the predetermined value, the remaining fuel amount warning device performs remaining amount warning control that produces vibration different than during normal operation by changing the combustion state of the engine by the combustion state changing device. A starter switch for starting the engine is made to serve also as a warning acknowledging button for stopping the remaining amount warning control for a predetermined time on the basis of an operation by an occupant.

This surge determination device is provided with a surge determination unit for determining the presence or absence of a surge of a compressor that outputs compressed air to an engine on the basis of a rotation speed of the engine and an air flow rate.

A protection device for preventing automobile engines from abnormal starts comprises automobile batteries (10), a start motor (20) and a control circuit (30) disposed therebetween. The control circuit (30) comprises a main control unit MCU1, a start switch (31), a start relay (321) and a power supply relay (322), the coil of the start relay (321) being connected to the automobile batteries (10) through the normally closed contact of the power supply relay (322). The start relay in the present invention is connected to the batteries rather than directly but through the normally closed contact of the power supply relay. In addition to being controlled by the main control unit, the start relay is also controlled by the power supply relay, thereby providing additional insurance and more effective protection so as to avoid the damage of the start motor due to erroneous actions.

A protection device for preventing automobile engines from abnormal starts comprises automobile batteries (10), a start motor (20) and a control circuit (30) disposed therebetween. The control circuit (30) comprises a main control unit MCU1, a start switch (31), a start relay (321) and a power supply relay (322), the coil of the start relay (321) being connected to the automobile batteries (10) through the normally closed contact of the power supply relay (322). The start relay in the present invention is connected to the batteries rather than directly but through the normally closed contact of the power supply relay. In addition to being controlled by the main control unit, the start relay is also controlled by the power supply relay, thereby providing additional insurance and more effective protection so as to avoid the damage of the start motor due to erroneous actions.

In an apparatus for detecting tip-over of a rammer equipped with a crankcase accommodating an output shaft rotatably connected to an engine, a movable unit accommodating a converter mechanism for converting rotation of the output shaft to vertical motion of a movable member, a tamping shoe connected to the movable unit, and a handle operable by an user, and adapted to thrust upward in the gravitational direction by the vertical motion of the movable member and go into a free fall to compact a ground surface, it is determined whether a detected engine speed becomes equal to or smaller than a threshold value set lower than an engine idling speed when the engine has been operated at a rammer working speed set greater than the engine idling speed, and if it does, it is discriminated that the rammer has tipped over.

In an apparatus for detecting tip-over of a rammer equipped with a crankcase accommodating an output shaft rotatably connected to an engine, a movable unit accommodating a converter mechanism for converting rotation of the output shaft to vertical motion of a movable member, a tamping shoe connected to the movable unit, and a handle operable by an user, and adapted to thrust upward in the gravitational direction by the vertical motion of the movable member and go into a free fall to compact a ground surface, it is determined whether a detected engine speed becomes equal to or smaller than a threshold value set lower than an engine idling speed when the engine has been operated at a rammer working speed set greater than the engine idling speed, and if it does, it is discriminated that the rammer has tipped over.

An internal combustion engine management system includes: a plurality of internal combustion engine units of which each includes an internal combustion engine, a first communicator configured to communicate with a server device, and a communication controller configured to transmit at least estimation information out of the estimation information which is used to estimate an environment in which the internal combustion engine is placed and information of a control map which is used to control the internal combustion engine to the server device using the first communicator; and the server device that includes a second communicator configured to communicate with the first communicator, and a processor configured to extract a second internal combustion engine unit having transmitted estimation information which is similar to the estimation information received from a first internal combustion engine unit out of the plurality of internal combustion engine units from the plurality of internal combustion engine units and to transmit the information of a control map received from the second internal combustion engine unit to the first internal combustion engine unit using the second communicator.

A construction machine management system in which a failure analysis or a failure-omen diagnosis of a machine body can be performed with a high degree accuracy and at a low cost is provided. In a machine body group of construction machines including at least one representative machine body having an engine control unit that detects a cumulative stress value of a diesel engine of the construction machine and a crankcase pressure sensor that detects a crankcase pressure, and at least one general machine body that has an engine control unit but does not have a crankcase pressure sensor, a center server performs a diagnosis of an omen of a failure state regarding the crankcase pressure of the general machine body based on correlation information between the cumulative stress value and the crankcase pressure obtained from the representative machine body and the cumulative stress value of the general machine body.

A rail vehicle has a diesel engine, an engine radiator and a cooling circuit that connects the diesel engine to the engine radiator. A cooling liquid is circulated in the cooling circuit, a cooling liquid temperature of the circulated cooling liquid and an outer air temperature of the atmospheric outer air are detected. The outer air temperature is compared with the outer air limit temperature, the cooling power of the engine radiator is set in such a way that the cooling liquid temperature corresponds to a normal operating temperature if the outer air temperature is less than the outer air limit temperature. The cooling power of the engine radiator is set such that the cooling liquid temperature corresponds to a lower operating temperature below the normal operating temperature if the outer air temperature is greater than the outer air limit temperature.