JPH0443731Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to an oil cooler with a built-in radiator for cooling torque converter oil or engine oil loaded in automobiles, particularly automatic vehicles.

"Prior art" This type of conventional oil cooler 10 has three
As shown in the figure, the inner and outer walls 12 and 1 of a corrugated pipe have convex portions 11 and 15 spirally provided on the pipe wall surface, respectively.
6 or a so-called spiral roll pipe, this oil cooler 10 is installed inside a radiator, and a high temperature is supplied to a spiral oil passage 13 provided between an outer pipe 16 and an inner pipe 12. The oil was cooled by passing cooling water through the oil and through the outside of the outer tube 16 and the inside of the inner tube 12, respectively.

``Problem to be solved by the invention'' In a conventional oil cooler, when the volume is kept constant, the cross-sectional area of the spiral oil passage portion 13 formed between the inner surface of the outer tube 16 and the outer surface of the inner tube 12 is becomes small, and the pressure difference (pressure loss) between the inlet side and the outlet side of the oil cooler 10 also becomes large. Furthermore, if the pressure loss is reduced by increasing the distance of the helical pitch, the surface area which is the heat transfer part of the oil cooler becomes smaller, resulting in a disadvantage that the heat exchange rate (the amount of heat dissipated from the oil) becomes smaller. In other words, in a double-pipe oil cooler, in order to increase the amount of heat dissipated with the same volume, the heat transfer area must be increased, and in order to increase this heat transfer area, the helical pitch of the convex portion must be reduced. Must be.

However, when the inner and outer pipes with a smaller spiral pitch are combined, the heat transfer area becomes larger and the amount of heat dissipated becomes larger, but the cross-sectional area of the oil passage section 13 provided between the inner and outer pipes becomes smaller. The pressure difference (pressure loss) between the inlet side and the outlet side of the oil cooler 10 increases. Here, to reduce the pressure difference between the inlet side and the outlet side of the oil cooler 10, the convex portions 11,
If the helical pitch of No. 15 is increased, the pressure loss will be reduced, and the surface area serving as the heat transfer portion will be reduced, resulting in a problem in that the amount of heat exchange will be reduced.

The present invention aims to increase the cross-sectional area of the oil passing portion in order to reduce pressure loss, and also to increase the heat dissipation effect by increasing the heat transfer area.

``Means for solving the problem'' This invention is based on the following:
Annular convex parts and annular concave parts are provided alternately at regular intervals in an outer pipe formed in a bellows shape, and a convex part formed spirally outward at a different pitch from the annular convex parts is crushed thinly. A means to solve this problem is to insert an inner pipe, combine the two concentrically, and provide a spiral oil passage between the inside of the outer pipe and the outside of the inner pipe. .

"Function" By forming a bellows-shaped outer pipe in which annular protrusions and annular concave parts are formed at regular intervals, an inner pipe with a spiral protrusion on the outside is flattened and formed by flattening the convex part. By enlarging the cross-sectional area of the oil passage provided between the outer pipe and the inner pipe, a sudden pressure drop is prevented and the pressure is changed in stages, making it possible to increase the heat dissipation area.

``Embodiment'' To explain the embodiment of the present invention with reference to the drawings, 1 is an outer pipe, and in order to make the heat transfer part, that is, the surface area as large as possible, a method called bellows or bellows is adopted. A large number of annular protrusions 2 are provided at regular intervals in the circumferential direction perpendicular to the center of the ring 1, and an annular recess 3 is formed between each annular protrusion 2. In this case, the pitch of the annular convex portions 2 should not be made too close to the point where they come into close contact with each other. That is, a radiator (not shown) is installed in the annular recess 3.
If the water inside stops flowing or the oil stops flowing into the annular convex portion 2, the outer pipe 1 becomes the same as a thick smooth pipe, and the heat transfer portion becomes small.

Reference numeral 5 denotes an inner pipe to be inserted into the outer pipe 1, which is called Thermoflex, and a convex part 6 is continuously formed in a spiral shape on the wall surface of the inner pipe 5, and this convex part 6 is flattened. The formed flexible inner pipe 5 is accommodated in the outer pipe 1 to form an oil cooler 9.

In order to enlarge the heat transfer part of the oil cooler 9 and to minimize the pressure loss on the inlet and outlet sides, the spiral protrusion 6 provided on the outer wall surface of the inner pipe 5 is flattened to make the outer pipe smaller. Since the cross-sectional area of the oil passing portion 7 provided between the inside of the inner pipe 1 and the outside of the inner pipe 5 is increased, and the surface area of the thinly crushed convex portion is reduced, the heat radiation surface is not reduced. Further, since the annular convex portion provided on the outer pipe and the convex portion provided on the outer surface of the inner pipe 5 are formed at different pitches, turbulent flow can be generated.

Next, to explain the operation of this embodiment, inside the outer pipe 1, which has annular protrusions 2 and annular recesses 3 alternately provided on the outer circumferential surface, an inner pipe having a maximum outer diameter slightly smaller than the inner diameter of the outer pipe 1 is formed. The pipe 5 is accommodated, and high-temperature oil is fed into the spiral oil passing portion 7 formed between the outer pipe 1 and the inner pipe 5, while the oil is cooled into the annular recess 3 existing in the outer pipe 1 and the inner pipe 5. The oil is cooled by circulating water.

In this case, the spiral oil passage section 7 provided between the outer pipe 1 and the inner pipe 5 has a large number of protrusions 2 arranged at regular intervals in a direction perpendicular to the center of the outer pipe 1.
Since the cross-sectional area of the oil passing portion 7 changes, a turbulent flow is generated in the oil, thereby preventing pressure loss between the inlet side and the outlet side.

In addition, the present invention has a convex portion 2 of the outer pipe 1 and the inner pipe 5.
You can combine various pitches of the outer pipe 1.
It is possible to further improve the efficiency by combining various intervals between the inner diameter of the inner pipe 5 and the outer diameter of the inner pipe 5 and taking various considerations into consideration.

"Effect of ideas" The present invention has the following effects.

Since thin-walled pipes are used, the weight of the product can be reduced, making it suitable for automotive use.If the radiator has the same performance as a conventional one, it can be made smaller and lighter, reducing costs. It has the advantage of helping improve vehicle engine performance.

Since the inner and outer pipes each have a basic shape of a cylinder, they are strong against deformation due to external pressure and internal pressure, and the walls of the inner and outer pipes can be made thin. The outer pipe is provided with annular protrusions at regular intervals, and the inner pipe is provided with spiral protrusions.
By changing the cross-sectional area of the oil passing section provided between the outer pipes, the oil passing through this section can be made into a turbulent flow to increase the amount of heat dissipation.

[Brief explanation of the drawing]

Figure 1 is a partially broken sectional view of the main part of the present invention.
Fig. 2 is a sectional view taken along the line A-A in Fig. 1, Fig. 3 is a partially cutaway front view of the conventional model, and Fig. 4 is Fig. 3 B-
It is a sectional view taken along the B line. 1... Outer pipe, 2... Annular convex part, 5... Inner pipe, 6... Thinly crushed spiral convex part, 7... Oil passing part.

Claims (1)

[Scope of utility model registration request] In an outer pipe formed in a bellows shape with annular protrusions and annular recesses alternately provided at regular intervals in the circumferential direction at right angles to the central axis, an outer pipe is formed spirally outward at different pitches from the annular protrusions. Built-in radiator with a spiral oil passage between the inside of the outer pipe and the outside of the inner pipe by inserting an inner pipe formed by crushing a convex part formed into a shape and combining them concentrically. type oil cooler.