Abstract: A heat exchanger assembled from multiple heat exchanging tubes. Each of the multiple heat exchanging tubes is formed as a flattened tube of 0.5 mm in thickness by press work or bending work of a stainless steel plate member having a thickness of 0.1 mm. Each of the multiple heat exchanging tubes is structured to have multiple lines of sequential wave crests and multiple lines of sequential wave troughs formed on each of flattened faces of the heat exchanging tube. The multiple lines of the sequential wave crests and the multiple lines of the sequential wave troughs are arranged to have a preset angle ? relative to a main stream of an air flow. The lines of the sequential wave crests and the lines of the sequential wave troughs are symmetrically folded back about folding lines arranged at a preset interval W along the main stream of the air flow.

Abstract: A plurality of heat-exchanger tubes, each of which has an inlet fin formed on a side surface on the air inlet side of a flattened hollow tube and extending upstream of air along the flow of air and an outlet fin formed on the side surface on the air outlet side of the hollow tube and extending downstream of the air along the flow of the air are arranged at regular intervals in such a manner that their oblong planes face one another, an upper header which supplies a first heat exchange medium is attached on top of the heat-exchanger tubes, and an lower header which collects the first heat exchange medium is attached at the bottom of the heat-exchanger tubes to form a heat exchanger.

Abstract: A plurality of heat-exchange tubes 30 each including a flat pipe including a groove 36 and wavelike depression-and-projection portions 33, 34 are arranged in parallel in such a manner that each of respective longitudinal directions thereof is a vertical direction, and a heat exchange medium is made to flow from an inlet 31 at each lower portion to an outlet 32 at each upper portion. Guide walls 43, 44 are provided in a shell 40, and exhaust gas is made to flow an inlet 41 at an upper portion to an outlet 42 at a lower portion, thereby making the exhaust gas meander in flow paths 46a to 46d and a space between the plurality of heat-exchange tubes 30.

Abstract: A plurality of flat tubes formed as a tube having notches by linearly cutting upper and lower parts from a hollow flat circular doughnut shape are stacked to structure a tube laminate. It is attached to a case so that a notch aligns with the notch and faces upward by an exhaust inflow end plate and that a notch aligns with the notch and faces downward by an exhaust outflow end plate. A cutoff valve is provided at an exhaust outflow end of an exhaust communication tube passing through the center of the tube laminate by heat insulation. While an internal combustion engine is warming up, the cutoff valve is closed to cause the exhaust to flow in gaps of the respective flat tubes from upward to downward as a whole and also a heat exchange medium is caused to flow in the respective flat tubes from downward to upward as a whole to have heat exchanged between the exhaust and the heat exchange medium to recover the exhaust heat.

Abstract: A plurality of flat tubes formed as a tube having notches by linearly cutting upper and lower parts from a hollow flat circular doughnut shape are stacked to structure a tube laminate. It is attached to a case so that a notch aligns with the notch and faces upward by an exhaust inflow end plate and that a notch aligns with the notch and faces downward by an exhaust outflow end plate. A cutoff valve is provided at an exhaust outflow end of an exhaust communication tube passing through the center of the tube laminate by heat insulation. While an internal combustion engine is warming up, the cutoff valve is closed to cause the exhaust to flow in gaps of the respective flat tubes from upward to downward as a whole and also a heat exchange medium is caused to flow in the respective flat tubes from downward to upward as a whole to have heat exchanged between the exhaust and the heat exchange medium to recover the exhaust heat.

Abstract: A heat exchanger assembled from multiple heat exchanging tubes. Each of the multiple heat exchanging tubes is formed as a flattened tube of 0.5 mm in thickness by press work or bending work of a stainless steel plate member having a thickness of 0.1 mm. Each of the multiple heat exchanging tubes is structured to have multiple lines of sequential wave crests and multiple lines of sequential wave troughs formed on each of flattened faces of the heat exchanging tube. The multiple lines of the sequential wave crests and the multiple lines of the sequential wave troughs are arranged to have a preset angle ? relative to a main stream of an air flow. The lines of the sequential wave crests and the lines of the sequential wave troughs are symmetrically folded back about folding lines arranged at a preset interval W along the main stream of the air flow.

Abstract: A flat tube includes pairs of dimple portions in a longitudinal direction thereof. Each of the pairs has a first dimple portion and a second dimple portion, which are slanted with respect to an intermediate line extending in the longitudinal direction at an intermediate position in a lateral direction so that inner end wall portions of the first and second dimple portions are located on the intermediate line, and so that the outer end wall potions thereof depart from the intermediate line in the lateral direction to be toward outer sides of the tube, respectively. The pairs of dimple portions are set to satisfy a relationship expressed by an inequality: 3?L2/L1?12, where L1 is a longitudinal projection length obtained by projecting one of the first and second dimple portions on the intermediate line, and L2 is a longitudinal pitch between adjacent pairs.

Abstract: An evaporator includes a plurality of laminated tubes, each of which is provided therein with a refrigerant passage, an inlet header chamber which is in communication with one end of the refrigerant passage, and an outlet header chamber which is in communication with the other end of the refrigerant passage. The inlet header chamber is located above the refrigerant passage. The inlet header chamber is partitioned by a partition wall into an inner header chamber and an outer header chamber which is disposed around the inner header chamber and which is in communication with the refrigerant passage. The inner header chambers of the adjacent tubes are in communication with each other. An assembly of the inner header chambers forms a header inlet tank chamber. The partition wall is provided with refrigerant holes located above a lowermost point a of the inner header chamber and at different levels.

Abstract: An evaporator includes a plurality of laminated tubes, each of which is provided therein with a refrigerant passage, an inlet header chamber which is in communication with one end of the refrigerant passage, and an outlet header chamber which is in communication with the other end of the refrigerant passage. The inlet header chamber is located above the refrigerant passage. The inlet header chamber is partitioned by a partition wall into an inner header chamber and an outer header chamber which is disposed around the inner header chamber and which is in communication with the refrigerant passage. The inner header chambers of the adjacent tubes are in communication with each other. An assembly of the inner header chambers forms a header inlet tank chamber. The partition wall is provided with refrigerant holes located above a lowermost point a of the inner header chamber and at different levels.

Abstract: An impeller in a water pump for circulation of cooling medium in a cooling system of an engine has a shroud with a shroud end to which the edges of the blade inlets are attached and which is formed in the cylindrical configuration substantially parallel to the rotary shaft. Each of the edges of the blade inlets is shaped so that it is continuously smooth from a shroud end surface at the inlet side thereof and extends upstream in the axial direction, while each of the edges of the blade inlets at the side of a casing extends substantially perpendicularly to the rotary shaft. The edge of the blade inlet attached to the cylindrical shroud end and the edge of the blade inlet at the casing side being connected therebetween by a smooth arc-like curve projecting convexly upstream. The inlet angle of the blade is set to substantially 0.degree. at the inlet edge at the shroud end and to an angle calculated substantially on the basis of the conventional design at the inlet edge at the casing side.

Abstract: A sintered article of diamond is obtained by coating the surface of diamond particles with 30 to 0.1% by volume, based on the total volume of the diamond particles and aids, of at least one member selected from the group consisting of the transition metals of Groups 4a, 5a, and 6a in the Periodic Table of Elements and boron and silicon, and sintering the coated diamond particles under conditions of high pressure and high temperature, which sintered article consists of 70 to 99.8% by volume of diamond and 30 to 0.2% by volume of the carbide of the coating substance. A method for the production of the sintered article of diamond is also disclosed.

Abstract: A sintered article of diamond is obtained by coating the surface of diamond particles with 30 to 0.1% by volume, based on the total volume of the diamond particles and aids, of at least one member selected from the group consisting of the transition metals of Groups 4a, 5a, and 6a in the Periodic Table of Elements and boron and silicon, and sintering the coated diamond particles under conditions of high pressure and high temperature, which sintered article consists of 70 to 99.8% by volume of diamond and 30 to 0.2% by volume of the carbide of the coating substance. A method for the production of the sintered article of diamond is also disclosed.

Abstract: In order to increase the heat exchange capacity and efficiency of a cooling fin for an automotive radiator, air conditioner heat exchanger, or the like, a plurality of small triangular or similar shaped projections which produce a texture similar to that of a vegetable grater, are arranged to project into the flow of a fluid medium which passes over the fin in a manner to split a part of the flow into spiralling flow patterns which curl along the surface of fin downstream of the projections and transfer heat from said surface to the fluid medium or vice versa.

Abstract: A heat exchanger having corrugated fins interposed between adjacent folds of a liquid tube, which corrugated fins severally contain in each of the holds thereof a louver having louver blades alternately projected from the base line of fin and having at least part of said louver blades so arranged that the states of inclination thereof relative to said base line of fin vary alternately.