Claims
- 1. A process for manufacturing the oil cooler having chambers connected to both ends of a tube bundle, hose fittings fixed to each chamber and a plurality of cooling fins fixed to the tube bundle, which comprises the steps of:
- (A) making cooling fins by forming a plurality of insertion holes of which inner brim is projected along an axial direction for inserting a plurality of tubes in each sheet to be transformed into a cooling fin, and by drilling a plurality of pores for inserting linear brazing materials, at positions closed to and spaced apart from said insertion holes respectively,
- (B) inserting a plurality of seamless tubes arranged in parallel into each of insertion holes of a number of the cooling fins respectively, and inserting linear brazing materials into the pores of each of the cooling fins, and
- (C) joining said brims of the cooling fins to the tubes by melting said brazing materials.
- 2. A process for manufacturing an oil cooler according to claim 1, further comprising the steps of:
- forming end chambers and inserting at least one fitting therein, thereby forming an insertion point,
- assembling said end chambers to said tubes wherein the plurality of the tubes are inserted to one chamber at each end, thereby forming an insertion point,
- winding said insertion points with linear brazing materials, and
- joining said brims of the cooling fins to the tubes, and said insertion points by melting said brazing materials.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 63-13383 |
Jan 1988 |
JPX |
|
DISCLOSURE OF THE INVENTION
This application is a division of application Ser. No. 415,342 filed as PCT/JP89/00055 on Jan. 10, 1989, published as WO89/06744 on July 27, 1989, now abandoned.
1. Technical Field
The present invention relates to an oil cooler and a process for manufacturing the same, and more particularly, to the oil cooler suitable for an automobile hydraulic-circuit, especially for an hydraulic-circuit of a power-steering unit and the process for manufacturing the same.
2. Background Art
Recently, in order to provide natural steering feeling to a power steering unit as much as possible, and in order to attain both stability performance at high speed traveling and light steerage characteristics at low speed traveling, pressure oil flowing through a hydraulic-circuit becomes to be controlled finely more and more. Accordingly, it is observed that the hydraulic-circuit tends to be complex, and oil temperature tends to be raised. For example conventional oil temperature has been about 100.degree. C. at the highest, but in the latest date, the oil temperature becomes about 120.degree. C. to 130.degree. C. at the highest. Further, it is anticipated that the oil temperature will be raised more and more in future.
On the other hand, an internal space of an engine compartment for installing the power-steering unit becomes gradually narrower, since a turbo-supercharger or the like is mounted in the engine compartment for improving traveling performance and the height of the engine compartment is lowered for the purpose of improving aero-dynamics characteristics and obtaining a good appearance design.
By the way, as oil coolers conventionally used in an automobile power-steering unit, the units shown in FIG. 13 and 14 have been known.
The former oil cooler is a suitably bent steel pipe 51 with a length of about 1 to 2 m and an external diameter of about 10 mm, and is connected in a midway of a rubber hose 52 constructing a hydraulic-circuit of the power steering unit.
The latter oil cooler comprises the above-mentioned pipe 51 and a large number of heat-radiating fins 53 attached thereon.
However, the conventional oil coolers need large installing space because their lengths are about 1 to 2 m as mentioned above, namely they are generally long. Then, in order to accommodate the tendency toward high temperature expected in future, the pipe 51 should be lengthened further for the purpose of increasing a radiating area. In that case, it will be impossible to install the oil cooler in the engine compartment which is narrow even now.
Furthermore, in the conventional oil coolers, when a pressure oil flow rate is large, the line resistance increases and then the pressure at positions in the piping is raised. Therefore, the leakage can be caused at the connecting portion between the pipe and the rubber hose. In addition, when the whole of the pipe is vibrated by the vibration of the automobile, noise is often caused. Those problems are also caused by the excessive length of the pipe.
The oil cooler and process for manufacturing the same of the present invention are provided in consideration of the above-mentioned problems. An object of the present invention is to provide an oil cooler which has very compact construction, high cooling efficiency and no problem as to the noise and the leakage. Another object of the present invention is to provide a process of easily manufacturing the oil cooler with low cost.
In accordance with the present invention, there is provided an oil cooler comprising:
The present invention also provides a process for manufacturing an oil cooler having chambers connected to both ends of a tube bundle, hose fittings fixed to each chamber and a large number of cooling fins fixed to the tube bundle, which comprises the steps of:
The oil cooler of the present invention has a structure having a plurality of tubes arranged in parallel, therefore the oil cooler can be made short and small. Accordingly, the oil cooler of the present invention can be easily installed in a narrow engine compartment. In addition, a plurality of tubes and the cooling fins fixed to the tubes provide a sufficient radiation area and therefore, the oil cooler can attain high cooling efficiency. Further, since a sectional area of the flow passage is enlarged and the length is shortened by employing a plurality of tubes, the resistance in the passage is small and the pressure rise in the passage is low, and therefore, leakage through the connecting portion is prevented. In addition, since a plurality of tubes act as struts and the inner brims of the insertion holes of the cooling fins act to prevent the tubes from twisting, the strength of the whole structure, especially torsional rigidity, becomes higher. Accordingly, vibration of the oil cooler can be restrained and noise can be generally prevented from generating.
In the manufacturing process of the present invention, each cooling fin is a piece of sheet, in which a plurality of insertion holes are formed. Therefore, the fixing of the cooling fins to a plurality of tubes is very easy than the case of fixing for a number of fins to the tubes one by one. In addition, since the cooling fin is a piece of a plain sheet, a yield rate of material is high. Then, the oil cooler of the present invention can be made with low cost.
PCT Information
| Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
| PCT/JP89/00055 |
1/20/1989 |
|
|
9/15/1989 |
9/15/1989 |
| Publishing Document |
Publishing Date |
Country |
Kind |
| WO89/06744 |
7/27/1989 |
|
|
US Referenced Citations (7)
Foreign Referenced Citations (5)
| Number |
Date |
Country |
| 52-36914 |
Aug 1977 |
JPX |
| 54-112942 |
Aug 1979 |
JPX |
| 58-21776 |
Feb 1983 |
JPX |
| 58-46991 |
May 1983 |
JPX |
| 61-115886 |
Sep 1986 |
JPX |
Divisions (1)
|
Number |
Date |
Country |
| Parent |
415342 |
Sep 1989 |
|
Patent Grant
5044545
