Hitachi, Ltd.

Akira Tomita

Masakatsu Hayashi

Masaaki Itoh

Takeo Tanaka

Takao Funamoto

Satoshi Kokura

Takashi Haramaki

Mituo Kudo

Katsuhiko Shiota

Mituo Kodoh

Yoshiaki Tsukuda

The vacuum tank is connected to an engine intake manifold, and a vacuum pump generates compulsarily a negative pressure so as to maintain the negative pressure at a predetermined setting pressure value. The vacuum pump has a diaphragm pump for discharging air in the vacuum tank a motor for driving the diaphragm pump. The vacuum tank pump is disposed in the vacuum tank. A vacuum switch assembly and the diaphragm pump are disposed on the vacuum tank. The motor is installed entirely in the vacuum tank. The volume of a negative pressure supply apparatus can be reduced, and the installing location of the negative pressure supply apparatus can be disposed at liberty.

Negative pressure supply apparatus for automobiles

A heat exchanger and a method of manufacturing a heat exchanger by brazing metal members mainly made of Al or Al alloy is disclosed. The heat exchanger has a plurality of brazed metal members, at least one of the brazed metal members being made of brazing sheet clad with a brazing material. The brazed portions of the metal members or the whole surface of the heat exchanger are coated with a corrosion-resistant fluoride flux consisting essentially of 25-40% KF, 38-54% AlF3 and 3-30% ZnF2 by weight which forms a corrosion-inhibiting metallic film.

Method of brazing an aluminum heat exchanger

A fin assembly for heat exchangers used in air conditioners or the like. The fin assembly is formed from a thin plate material which is bent and wound to have a plurality of alternating turns each of which constitutes a fin. The fin is provided with a multiplicity of louvers cut-out and raised from the major plane thereof. The fins are inclined at an angle .theta. which is 30.degree. or smaller to the direction of flow of the gas entering the fin assembly, while the louvers are inclined at an angle .gamma. which is 20.degree. or smaller to the direction of flow of the gas entering the fin assembly in the direction opposite to the direction of inclination of the fin plates.

Fin assembly for heat exchangers

A heat exchanger fin according to the invention has a multiplicity of fins arranged substantially in parallel with the direction of air flow and at least one heat transfer tube to which said fins are connected in a heat conducting relation. A multiplicity of louvers inclined by a small angle to the direction of air flow are formed in said fins. According to this construction, it is possible that the air as a whole can flow substantially straight across the heat exchanger and can strongly collide with all louvers, thereby to ensure a reduced flow resistance encountered by the air flow, as well as improved heat transfer performance of the heat exchanger.

Heat exchanger fin

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Mito, Japan

Akira Tomita