Abstract: A metal member includes a first layer and a second layer. The second layer has an average crystal grain size different from an average crystal grain size of the first layer. An intermediate layer having an average crystal grain size smaller than the average crystal grain sizes of the first layer and the second layer is interposed between the first layer and the second layer.

Abstract: An electric pump includes: a motor that drives a pump; and a control unit to which an input signal for driving the motor is input from an external device, which outputs a drive signal based on the input signal, and which outputs a pulse signal indicating a rotation state of the motor to the external device, in which the control unit is configured to change both of a frequency and a duty ratio of the pulse signal so as to be capable of discriminating whether the motor is in a drive state or a stop state and between a plurality of states of the motor in the stop state.

Abstract: A metal member includes a first layer and a second layer. The second layer has an average crystal grain size different from an average crystal grain size of the first layer. An intermediate layer having an average crystal grain size smaller than the average crystal grain sizes of the first layer and the second layer is interposed between the first layer and the second layer.

Abstract: An electric pump includes: a motor that drives a pump; and a control unit to which an input signal for driving the motor is input from an external device, which outputs a drive signal based on the input signal, and which outputs a pulse signal indicating a rotation state of the motor to the external device, in which the control unit is configured to change both of a frequency and a duty ratio of the pulse signal so as to be capable of discriminating whether the motor is in a drive state or a stop state and between a plurality of states of the motor in the stop state.

Abstract: An engine cooling device includes: a water pump; a radiator; a first cooling water channel going through the radiator; a second cooling water channel not going through the radiator; a solenoid valve provided in the second cooling water channel; and a control unit. The control unit moves, at a time of closing the solenoid valve, a valve body in a valve closing direction while the cooling water is passing at a decreased flow rate so as to close the solenoid valve to cut off passage of the cooling water in the second cooling water channel.

Abstract: A liquid ejection head includes a nozzle formation member having a liquid repellent layer disposed on a droplet ejection face of a nozzle substrate in which one or more nozzle orifices is formed to eject droplets. The liquid repellent layer includes a first sub-layer and a second sub-layer. The first sub-layer contains a higher proportion of low-molecular-weight molecules than the second sub-layer. The second sub-layer contains a higher proportion of high-molecular-weight molecules than the first sub-layer. Both the first sub-layer and the second sub-layer are exposed on a surface of the nozzle formation member.

Abstract: A liquid ejection head includes a nozzle formation member having a liquid repellent layer disposed on a droplet ejection face of a nozzle substrate in which one or more nozzle orifices is formed to eject droplets. The liquid repellent layer includes a first sub-layer and a second sub-layer. The first sub-layer contains a higher proportion of low-molecular-weight molecules than the second sub-layer. The second sub-layer contains a higher proportion of high-molecular-weight molecules than the first sub-layer. Both the first sub-layer and the second sub-layer are exposed on a surface of the nozzle formation member.