摘要:
An aluminum nitride (AlN) sintered product with a high thermal conductivity of 120 W/m.multidot.k or above can be produced at a relatively low sintering temperature of 1650.degree. C. or below in accordance with the following process of the present invention. That is, an A1N powder having a specific surface in a region of about 3.5 to 8 m.sup.2 /g and an oxygen content between 0.5 to 1.8 wt % is mixed with optimum additive amounts of sintering aids (I) to (III) to obtain a mixture powder. The sintering aid (I) is at least one selected from the group consisting of rare earth oxides and rare earth compounds which are converted to corresponding rare earth oxides by the sintering. The sintering aid (II) is at least one selected from the group consisting of alkaline earth oxides and alkaline earth compounds which are converted to corresponding alkaline earth oxides by the sintering. The sintering aid (III) is at least one selected from the group consisting of LAB.sub.6, NbC, and WB. The optimum additive amount of LaB.sub.6 is in a range of 0.05 to 3 wt % of the A1N sintered product. The mixture powder is compacted, and then sintered at the sintering temperature in a non-oxidation atmosphere to obtain the A1N sintered product.
摘要:
An exhaust gas recirculating system for a combustion engine has at least one cylinder communicating with a source of combustible air-fuel mixture through at least one intake port adapted to be selectively closed and opened for effecting the interruption and admission of the supply of the combustible mixture into the combustion chamber, the cylinder also communicating with an exhaust system through first and second exhaust ports both adapted to be selectively opened and closed. The exhaust gas recirculating system includes an intake valve for selectively opening and closing the intake port, first and second exhaust valves each for selectively closing and opening the associated first and second exhaust ports, wherein the first exhaust valve is operable to completely close the associated first exhaust port subsequent to the complete closure of the second exhaust port by the associated second exhaust valve, an exhaust shutter valve for selectively opening and closing a passage extending between the first exhaust port and the exhaust system, and a control unit for controlling the shutter valve according to an engine operating condition to adjust the amount of a portion of the exhaust gases allowed to substantially remain within the cylinder.
摘要:
An internal combustion engine is provided with a fuel injection valve in an intake passage communicated with a combustion chamber and a swirl controlling device for controlling a swirling motion to be given to intake air in a circumferential direction of the cylinder forming the combustion chamber. When the engine load is low, the fuel injection valve is controlled to inject fuel by an amount required for one power stroke a predetermined time after the intake valve is opened and during the intake stroke, and the swirl controlling device is controlled to give intake air a swirling motion. A correction device is provided, which, when the engine is cold, controls the fuel injection valve to start fuel injection before the intake valve is opened and also controls the swirl controlling device to suppress production of swirling motion of intake air.
摘要:
The combustion chamber for an internal combustion engine is formed by a main combustion chamber defined by a recess formed in a part of the lower face of a cylinder head and a squish zone which is a narrow space formed between the top surface of the piston in the top dead center and the substantially flat portion of the lower surface of the cylinder head around the recess. A spark plug is disposed in a position near the squish zone. A fuel injection valve is provided to inject fuel into an intake passage communicated with the combustion chamber by way of an intake valve. The fuel injection valve is controlled, at least when the engine load is low, to inject fuel by an amount required for one power stroke and to terminate fuel injection before the middle of the intake valve opening time at latest so that stratification of air and fuel can be obtained in which rich mixture is accumulated in the lower portion of the combustion chamber and lean mixture in the upper portion of the same.
摘要:
Disclosed is a wet process for efficiently and economically removing a specific gas component and/or solid component from a gas containing the same wherein the gas is countercurrently contacted with a scrubbing liquid in a perforated or grid plate column without weir and downcomer and having a free-space ratio of 0.30 to 0.60 under the conditions of a superficial gas velocity of from 1.5 to 8 m/sec and a liquid flow rate of from more than 110,000 to 250,000 kg/m.sup.2 .multidot. hr.
摘要翻译:公开了一种用于从含有该气体的气体中有效和经济地除去特定气体组分和/或固体组分的湿法,其中气体与穿孔或格栅板塔中的洗涤液逆流接触而没有堰和降液管, 空隙率为0.30〜0.60,表观气体速度为1.5〜8m /秒,液体流量为110,000〜250,000kg / m 2·x·hr。
摘要:
An automatic machining system incorporating all the features of a numerically controlled type machine while eliminating the need for paper tapes. The tool receiving head incorporates means for identifying the moment of contact between tool and work piece, avoiding the need for inputting start position data. Motion control and drive means are provided for X, Y and Z head movement. The novel design provides drilling or punching by insertion of the proper tool in a head adapted to receive either tool.Visual displays provide step by step directions and allow for selection of the machining operation and sequential execution of the machining steps in accordance with inputted data requested by the display.The punching tool operates automatically simply under control of Z axis movement.