Abstract: An ink-jet recording apparatus is provided with an ink tank, a recording head, an ink passage extending from the ink tank to the recording head, and a sub-tank arranged on the ink passage. The apparatus has a first ink passage, a second ink passage, and an ultrasonic transducer. The first ink passage supplies ink from the ink tank to the sub-tank. The second ink passage has an ink outlet port, through which the ink is drawn from the sub-tank into the recording head. The ultrasonic transducer applies ultrasonic vibration to the ink contained in the sub-tank. The ink outlet port of the second ink passage is arranged near the ultrasonic transducer.

Abstract: In a cleaning unit that cleans nozzles are provided a support base, a wiping portion that moves together with the support base to clean an ink on the nozzles, and a suction nozzle that is provided on the support base through a spring behind the wiping portion with respect to a traveling direction along which a cleaning operation is performed and sucks the ink subjected to cleaning. The wiping portion is moved by a set pin to adjust a gap between the wiping portion and a recording head, and contact cleaning or non-contact cleaning is selected at the time of cleaning. As a result, there can be provided an inkjet recording apparatus that can prevent an ink-repellant coating from being abraded, stably eject the ink, and record a high-quality image.

Abstract: An ink-jet recording apparatus is provided with an ink tank, a recording head, an ink passage extending from the ink tank to the recording head, and a sub-tank arranged on the ink passage. The apparatus has a first ink passage, a second ink passage, and an ultrasonic transducer. The first ink passage supplies ink from the ink tank to the sub-tank. The second ink passage has an ink outlet port, through which the ink is drawn from the sub-tank into the recording head. The ultrasonic transducer applies ultrasonic vibration to the ink contained in the sub-tank. The ink outlet port of the second ink passage is arranged near the ultrasonic transducer.

Abstract: An ink set for an image recording apparatus, includes a first ink, and a second ink which has the same color base as that of the first ink but is different from the first ink in density. A coloring material having a color base different from that of the first ink is mixed in the second ink in such a manner that a hue thereof approximates a hue of the first ink.

Abstract: In a cleaning unit that cleans nozzles are provided a support base, a wiping portion that moves together with the support base to clean an ink on the nozzles, and a suction nozzle that is provided on the support base through a spring behind the wiping portion with respect to a traveling direction along which a cleaning operation is performed and sucks the ink subjected to cleaning. The wiping portion is moved by a set pin to adjust a gap between the wiping portion and a recording head, and contact cleaning or non-contact cleaning is selected at the time of cleaning. As a result, there can be provided an inkjet recording apparatus that can prevent an ink-repellant coating from being abraded, stably eject the ink, and record a high-quality image.

Abstract: An ink head includes an ink head module and a nozzle plate. The ink head module has a plurality of ink chambers in which ink is retained. The nozzle plate is attached to the ink head module. The nozzle plate has at least one nozzle to jet ink inside the ink chamber. The surface of the nozzle plate opposing to a recording medium has a first region coming in contact with an opening of the nozzle and a second region other than the first region. Water repellency of the first region is higher than that of the second region.

Abstract: An ink jet printer includes ink jet heads for recording an image on a recording medium, an ink bottle for holding ink, an ink supply path connecting the ink bottle to each ink jet head, and an electromagnetic valve provided on the path. In the printer, the bottle, the valve and the heads are arranged downward in this order in the vertical direction, the path constantly exists upwards in the vertical direction in such a manner that air entered into the path moves up above the valve due to a difference in the specific gravity between the air and the ink, the path is provided with a branching portion provided between the valve and the heads, and a sub ink tank is provided at an end of the branching portion so as to be positioned lower than the heads in the vertical direction.

Abstract: An ink set for an image recording apparatus, includes a first ink, and a second ink which has the same color base as that of the first ink but is different from the first ink in density. A coloring material having a color base different from that of the first ink is mixed in the second ink in such a manner that a hue thereof approximates a hue of the first ink.

Abstract: An ink jet printer includes ink jet heads for recording an image on a recording medium, an ink bottle for holding ink, an ink supply path connecting the ink bottle to each ink jet head, and an electromagnetic valve provided on the path. In the printer, the bottle, the valve and the heads are arranged downward in this order in the vertical direction, the path constantly exists upwards in the vertical direction in such a manner that air entered into the path moves up above the valve due to a difference in the specific gravity between the air and the ink, the path is provided with a branching portion provided between the valve and the heads, and a sub ink tank is provided at an end of the branching portion so as to be positioned lower than the heads in the vertical direction.

Abstract: An ink head includes an ink head module and a nozzle plate. The ink head module has a plurality of ink chambers in which ink is retained. The nozzle plate is attached to the ink head module. The nozzle plate has at least one nozzle to jet ink inside the ink chamber. The surface of the nozzle plate opposing to a recording medium has a first region coming in contact with an opening of the nozzle and a second region other than the first region. Water repellency of the first region is higher than that of the second region.

Abstract: An ink head according to one aspect of the present invention includes an ink head module and a nozzle plate. The ink head module has a plurality of ink chambers in which ink is retained. The nozzle plate is attached to the ink head module. The nozzle plate has at least one nozzle to jet ink inside the ink chamber. The surface of the nozzle plate opposing to a recording medium has a first region coming in contact with an opening of the nozzle and a second region other than the first region. Water repellency of the first region is higher than that of the second region.

Abstract: An EGR control system for a direct injection spark ignition engine operated at a plurality of the combustion modes comprising stratified-charge combustion and premix-charge combustion. The system includes a flow rate control valve equipped at the EGR passage to regulate flow rate of the exhaust gas to be recirculated which is operated when the one combustion mode is determined to be changed to another of a plurality of the combustion modes, thereby ensuring an EGR amount that is neither deficient nor excessive for the combustion mode, while preventing misfire from happening and preventing the degradation of drivability, fuel economy and emission performance from occurring. Alternatively, the system includes an actuator for regulating an opening of a throttle valve or a second EGR control valve installed in a branch passage and a passage switching valve for switching the EGR passage and the branch passage.

Abstract: A gasoline direct-injection engine includes a cavity provided in a top portion of a piston and constituting a portion of a combustion chamber defined between a cylinder head and the top portion of the piston, a fuel injection valve mounted in the cylinder head for injecting gasoline directly into the combustion chamber, and a spark plug also mounted in the cylinder head to face the combustion chamber. In this gasoline direct-injection engine, the fuel injection valve facing a substantially central portion of a ceiling surface of the combustion chamber is mounted in the cylinder head to have an axis substantially parallel to an axis of the piston, and the cavity provided in the top portion of the piston and disposed below the fuel injection valve and the spark plug is defined so that it is deeper in an area corresponding to the spark plug than in an area corresponding to the fuel injection valve.

Abstract: An internal combustion engine includes a valve operating device operatively connected to a pair of intake valves and capable of opening and closing one of the intake valves in accordance with the operating condition of the engine and opening and closing the other intake valve in a small lift amount, thereby producing a deflection of the intake air drawn into the combustion chamber, and a fuel injection valve for injecting a fuel toward the pair of intake valve bores that are independently opened and closed by the intake valves, respectively. The timing of the opening and closing of the intake valve that is opened and closed only in the small lift amount is set at a time point such that the lift amount is maximized in the first half of the intake stroke of the piston. This promotes the atomization of the fuel which is being drawn in with the intake air by the opening of the intake valve opened and closed in the small lift amount, and to enhance the combustibility in the combustion chamber.

Abstract: In an internal combustion engine comprising a valve operating system connected to a pair of intake valves and arranged to open one of the intake valves only in a very small amount such that the one intake valve is brought into its substantially inoperative state, in a suction stroke mainly in a low speed rotation region of the engine, a fuel injection valve capable of injecting fuel toward a pair of intake ports independently corresponding to the intake valves, and a control means for controlling the operation of the fuel injection valve, the control means is arranged to control the fuel injection valve with a fuel injection completion time determined within a suction stroke, when the one intake valve is in the substantially inoperative state.

Abstract: An internal combustion engine having an assist air supply device for finely dividing injected fuel and an exhaust gas recirculation device for selectively circulating an exhaust gas from an exhaust passage into an air intake passage. In this internal combustion engine, a swirl operation for a lean burn during a low load on the engine and a non-swirl operation for a burn based on a theoretical air-fuel ratio can be selectively switched between such operations. In the non-swirl operation, the supply of an assist air and the recirculation of a large amount of an exhaust gas are carried out. This makes it possible to reduce both specific consumption of fuel and the amount of NO.sub.x in the exhaust gas over the entire operational region of the engine.

Abstract: A fuel injection type internal combustion engine has a pair of intake ports provided in a cylinder head to connect a pair of intake valve bores facing a combustion chamber with a single intake inlet end. A fuel injection valve is disposed in an orientation frm the intake inlet end toward both the intake valve bores and includes an assist-air supply means for finely atomizing the fuel. A valve operating mechanism is provided for selectively stopping the intake through one of the intake ports in accordance with the operational condition of the engine. A control means is connected to the assist-air supply means for controlling the assist-air supply means to stop the supply of assist air from the assist-air supply means in at least a portion of an operational region in which the intake through one of the intake ports is substantially stopped.