JPH07280469A - Water-cooled oil cooler - Google Patents

Abstract

PURPOSE:To simplify a structure and to improve a heat exchanging efficiency by integrally forming outer fins for forming spiral oil passage between an inner pipe and outer pipes and inner fins provided on an inner periphery of the inner pipe and spirally extended along an axial direction by extrusion molding. CONSTITUTION:Oil in an oil passage 31 is heat exchanged with cooling water in a cooling water passage 30 through a tube wall of an inner pipe 26, tube walls of outer pipes 26, outer fins 32 and inner fins 33 to be cooled. Hereupon, since the passage 31 is spirally formed by the fins 32, its entire length is sufficiently increased, a turbulent flow is generated at a flow of the oil to surtably agitate the oil. A contact area of the oil with the water is increased by the fins 32 and 33. Since an oil cooler boy 27 is integrally formed and base end sides of the fins 32, 33 are increased in thicknesses, its heat transfer rate is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled oil cooler for cooling an oil liquid such as hydraulic oil of an automatic transmission of an automobile.

[0002] Generally, an oil cooler is provided in a hydraulic circuit of an automatic transmission of an automobile in order to cool working oil such as a torque converter. As an oil cooler of this type, for example, as shown in FIG. 10, a water-cooled oil cooler 3 incorporated in a lower tank 2 of an engine cooling radiator 1 is known. In FIG. 10, 4 is an upper tank,
Reference numeral 5 is a radiator core, 6 is a radiator cap, 7 is a cooling water inlet, and 8 is a cooling water outlet.

As shown in FIGS. 11 and 12, a water-cooled oil cooler 3 has a cylindrical outer pipe 10 on the outer periphery of a cylindrical inner pipe 9 having both ends closed and an oil liquid passage 9a formed therein. Provided with inner pipe 9 and outer pipe
It has a double pipe structure in which a cooling water passage 10a is formed between the cooling water passage 10a and the cooling water passage 10. At both ends of the inner pipe 9, the outer pipe
An inlet pipe 11 and an outlet pipe 12 penetrating the pipe wall of 10 are connected, and a cooling water inlet 13 and a cooling water outlet 14 are formed at both ends of the outer pipe 10. Further, cooling fins 15 (corrugated fins) are provided on the inner peripheral portion of the pipe wall of the inner pipe 10.

The inlet pipe 11 and the outlet pipe 12 are connected to a hydraulic circuit (not shown) of the automatic transmission, and the cooling water inlet 13 and the cooling water outlet 14 are connected to a cooling water passage (not shown) of the radiator 1. )It is connected to the. Then, the hydraulic fluid (about 110 ° C.) of the automatic transmission is circulated to the oil liquid passage 9a in the inner pipe 9 through the inlet pipe 11 and the outlet pipe 12, and the engine cooling water (80 Cooling water inlet 13 and cooling water outlet
The hydraulic oil is circulated to the cooling water passage 10a in the outer pipe 10 via 14 and heat-exchanged via the pipe wall of the inner pipe 9 and the cooling fins 15 to cool the working oil.

In addition, as a water-cooled oil cooler,
For example, as shown in FIG. 13, there is one that is mounted on an oil filter mounting portion (not shown) of an engine to cool the engine lubricating oil. As shown in FIG. 13, in the oil cooler 16, cores 19 each having an annular lubricating oil passage 17 and a cooling water passage 18 are laminated (four layers), and the lubricating oil is supplied with a lubricating oil inlet 20 and a lubricating oil outlet (not shown). ) To the lubricating oil passage 17, and the cooling water is supplied to the inlet pipe 21 and the outlet pipe.
The lubricating oil is circulated through the cooling water passage 18 via 22 and exchanges heat to cool the lubricating oil. In order to increase the amount of heat exchanged, the cooling fins 23 are provided in the lubricating oil passage 17.
(Corrugated fin) is provided.

Further, Japanese Utility Model Publication No. 5-23981 discloses a water-cooled oil cooler in which the manufacturing cost is reduced by integrally forming a heat exchanger main body with an aluminum extrusion molding material.

[0007]

However, in the conventional water-cooled oil cooler 3 having a double pipe structure shown in FIGS. 10 to 12, it is necessary to reduce the size in order to store it in the lower tank 2 of the radiator 1. In order to increase the cooling efficiency, cooling fins 15 are provided on the inner peripheral portion of the inner wall of the inner pipe 9. Further, since the inner pipe 9 and the outer pipe 10 form a double pipe structure, the number of joints of each member is large. Therefore, the number of parts increases, the structure becomes complicated, the number of assembly steps and the manufacturing cost increase, and
If there are many joints, there is a problem that fluid leakage easily occurs and the burden of quality control increases.

In the oil cooler 16 shown in FIG. 13, since a plurality of cores 19 provided with cooling fins 23 are laminated, the number of parts is large and the structure is complicated, and it has the same problem as described above. Further, the one disclosed in Japanese Utility Model Publication No. 5-23981 also has a problem that the manufacturing cost becomes high because the corrugated fin is provided in the oil passage.

The present invention has been made in view of the above points, and an object thereof is to provide a water-cooled oil cooler having a simple structure and excellent heat exchange efficiency.

[0010]

In order to solve the above-mentioned problems, a water-cooled oil cooler according to claim 1 has an inner pipe that forms a cooling water passage and an outer pipe provided outside the inner pipe. An outer fin provided on an outer peripheral portion of the inner pipe and spirally extending along an axial direction to form a spiral oil liquid passage between the inner pipe and the outer pipe; and an inner periphery of the inner pipe. It is characterized in that the inner fin, which is provided in the portion and is spirally extended along the axial direction, is integrally formed by extrusion molding.

The water-cooled oil cooler according to claim 2 is
In addition to the above, a plurality of inner fins and outer fins are provided, and the base end side on the inner pipe side is formed thicker than the tip end side.

The water-cooled oil cooler according to claim 3 is
In addition to the above, the inner fin and the outer fin are characterized in that they are arranged offset in the circumferential direction of the inner pipe.

The water-cooled oil cooler according to claim 4 is
In addition to the above, an oil liquid reservoir is provided at both ends of the oil liquid passage.

[0014]

With this configuration, when the cooling water is circulated in the cooling water passage and the oil liquid is circulated in the oil liquid passage, the oil liquid heats the cooling water through the inner pipe, the outer pipe, the inner fin and the outer fin. Cooled by replacing. At this time, since the oil liquid passage is formed in a spiral shape by the outer fins, the total length is sufficiently long, turbulence is generated in the flow of the oil liquid to appropriately stir the oil liquid, and the outer fins and the inner fins are used. The contact area of oil liquid and cooling water becomes large, and the amount of heat exchanged becomes large. Furthermore, since the inner pipe, the outer pipe, the inner fins and the outer fins are integrally formed by extrusion molding, the number of joints of each member is reduced, heat transfer rate is improved, and leakage of oil liquid and cooling water can be prevented. It is possible, and the number of parts is small.

By providing a plurality of inner fins and outer fins, and forming the base end side on the inner pipe side thicker than the tip end side, the heat transfer coefficient is improved.

By circulating the oil liquid through the oil liquid reservoir, the flow of the oil liquid in the oil liquid passage is made uniform and the amount of heat exchanged is increased.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in FIGS. 1 to 7, a water-cooled oil cooler 24 has a double pipe structure in which an outer pipe 26 is provided outside a cylindrical inner pipe 25.
And substantially cylindrical cap members 28 and 29 joined to both ends of the oil cooler body 27.

In the oil cooler main body 27, a cooling water passage 30 is formed inside the inner pipe 25, and an oil liquid passage 31 (described later) is formed between the inner pipe 25 and the outer pipe. On the outer peripheral portion of the inner pipe 25, a plurality (12 in the figure) of outer fins 32 are formed, which extend in a spiral shape along the axial direction and whose tip end is coupled to the inner peripheral portion of the outer pipe 26. , A plurality of outer fins 32 are provided between the inner pipe 25 and the outer pipe 26.
Individual oil solution passages 31 are formed. The outer fin 32 has a base end portion (on the inner pipe 25 side) thicker than a tip end portion (outer pipe 26).

On the inner peripheral portion of the inner pipe 25, a plurality of (12 in the figure) inner fins 33 spirally extending along the axial direction are formed. Inna Fin 33
The base end (on the inner pipe 25 side) is thicker than the tip. As shown in FIG. 2, the outer fin 32 and the inner fin 33 are spirally formed at the same portion on the outer side and the inner side of the inner pipe 25 at the same pitch. Alternatively, as shown in FIG. 6, the outer fin 32 and the inner fin 32 having the same pitch may be used.
33 and 33 may be arranged offset from each other on the outer side and the inner side of the inner pipe 25.

The outer fin 32 and the inner fin
The twist angle of 33 is the axial dimension of the inner pipe (100 m
m) about 90 °, 180 ° in addition to 360 ° shown in the figure
Alternatively, it can be set arbitrarily such as 200 ° or more.

The oil cooler body 27 is extruded while being twisted using aluminum or an alloy thereof, so that the spiral outer fins 32 and inner fins 33 having the same pitch are replaced by the inner pipe 25 and the outer pipe.
It is formed integrally with 26.

The cap members 28 and 29 include large diameter portions 28a and 29a fitted to the outer peripheral portion of the outer pipe 26 and the inner pipe 25.
Has small diameter parts 28b and 29b fitted to the outer peripheral part of
It is joined to both ends of the oil cooler body 27 by brazing or the like. The small diameter portion 28b forms the cooling water inlet 34 communicating with one end side of the cooling water passage 30.
Thus, a cooling water outlet 35 communicating with the other end of the cooling water passage 30 is formed. Further, the outer pipe 26 and the outer fin 32 are shorter in axial dimension than the inner pipe 25, and both end portions of the oil liquid passage are provided between the inner pipe 25 and the large diameter portions 28a, 29a of the cap members 28, 29. The oil liquid reservoirs 36, 37 communicating with the are formed. An oil liquid outlet pipe 38 communicating with the oil liquid reservoir 36 is connected to the large diameter portion 28a,
An oil liquid inlet pipe 39 communicating with the oil liquid reservoir 37 is connected to the large diameter portion 29a.

The operation of the present embodiment configured as above will be described below.

The oil liquid inlet pipe 39 and the oil liquid outlet pipe 38 are connected to a hydraulic circuit (not shown) such as an automatic transmission, and an oil liquid such as hydraulic oil is supplied from the oil liquid inlet pipe 39 to the oil liquid reservoir 37. Introduce and oil passage
It is circulated to 31 and sent to the oil liquid reservoir chamber 36, and further circulated through the oil liquid outlet pipe 38. Further, the cooling water inlet 34 and the cooling water outlet 35 are connected to a cooling system (not shown) such as an engine, and the cooling water is circulated through the cooling water passage 30.

Then, the oil liquid in the oil liquid passage 31 is transferred to the inner wall of the inner pipe 25, the outer wall of the outer pipe 26, and the outer fin.
It is cooled by exchanging heat with the cooling water in the cooling water passage 30 via 32 and the inner fin 33.

At this time, the oil liquid passage 31 has the outer fin 32
Since it is formed in a spiral shape by the above, the total length is sufficiently long, and a turbulent flow is generated in the flow of the oil liquid to appropriately stir the oil liquid. Also, the outer fin 32 and the inner fin
33 increases the contact area of oil liquid and cooling water.
Since the oil cooler body 27 is integrally formed and the outer fin 32 and the inner fin 33 have thicker base ends, the heat transfer coefficient is improved. Further, the oil liquid is introduced and led out through the oil liquid sump chambers 36, 37, so that the oil liquid passage
The flow in 31 is made uniform. As described above, the amount of heat exchanged between the oil liquid and the cooling water is increased, and the cooling efficiency is improved.

Further, since the oil cooler main body 27 is integrally formed by extrusion molding and no corrugated fins are used, the number of joints of each member is reduced, heat transfer coefficient is improved, and oil liquid and cooling water are leaked. In addition, the structure is simple, the number of parts is small, and the number of assembling steps is also small. Then, an inexpensive material such as an aluminum alloy can be used for continuous assembly by brazing in the furnace, which can improve the production efficiency and reduce the manufacturing cost. Further, it is possible to reduce the size and weight by improving the cooling efficiency and using a lightweight material such as an aluminum alloy.

In the above embodiment, the cap members 28,
The large diameter portions 28a, 29a and the small diameter portions 28b, 29b of 29 are integrally formed. For example, as shown in FIG.
Only the 29 side is shown), but these may be joined as separate bodies by brazing or the like. Further, in the above-described embodiment, the oil liquid reservoirs 36 and 37 are formed by the large diameter portions 28a and 29a of the cap members 28 and 29 and the inner pipe 25, but as shown in FIG. (Only the side is shown), large diameter parts 28b, 29b in which the small diameter parts 28a, 29a are separated
It is also possible to form the oil liquid reservoirs 36 and 37 by the small diameter portions 28a and 29a and the large diameter portions 28b and 29b.

[0030]

As described in detail above, in the water-cooled oil cooler of the present invention, since the oil liquid passage is formed in a spiral shape by the outer fin, the total length is sufficiently long, and
A turbulent flow is generated in the flow of the oil liquid to appropriately stir the oil liquid, and the outer fins and the inner fins increase the contact area of the oil liquid and the cooling water, thereby increasing the amount of heat exchange. Furthermore, since the oil cooler body is integrally formed by extrusion molding, the number of joints of each member is reduced, heat transfer coefficient can be improved, and leakage of oil liquid and cooling water can be prevented. The score is small. In addition, by providing a plurality of inner fins and outer fins and forming the base end side on the inner pipe side thicker than the tip side, the heat transfer coefficient is improved. further,
By circulating the oil liquid through the oil liquid reservoir, the flow in the oil liquid passage is made uniform and the amount of heat exchanged is increased. As a result, the cooling efficiency can be improved, and since the structure is simple and the number of parts is small, the number of assembling steps and the manufacturing cost can be reduced, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a side surface of an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the oil cooler body taken along the line AA in FIG.

3 is a cross-sectional view of the side of the device of FIG. 1 taken along the line BB in FIG.

4 is a side view of the device of FIG. 1. FIG.

5 is an end view of the device of FIG. 1. FIG.

FIG. 6 is a vertical cross-sectional view of the oil cooler main body when the outer fin and the inner fin are arranged offset from each other in the apparatus of FIG.

7 is an exploded side view of the device of FIG.

FIG. 8 is an enlarged vertical cross-sectional view showing a joint portion between an oil cooler body and a cap member according to another embodiment of the present invention.

FIG. 9 is an enlarged vertical sectional view showing a joint portion between an oil cooler body and a cap member according to still another embodiment of the present invention.

FIG. 10 is a front view of a radiator incorporating a conventional water-cooled oil cooler having a double pipe structure.

11 is a side view of the water-cooled oil cooler of the apparatus of FIG.

12 is a vertical sectional view taken along the line CC of FIG.

FIG. 13 is a vertical cross-sectional view of a side surface of a water-cooled oil cooler mounted on an oil filter mounting portion of an engine.

[Explanation of symbols]

 24 Water-cooled oil cooler 25 Inner pipe 26 Outer pipe 30 Cooling water passage 31 Oil liquid passage 32 Outer fin 33 Inner fin 36,37 Oil liquid reservoir

Claims (4)

[Claims] 1. An inner pipe forming a cooling water passage,
An outer pipe provided on the outer side of the inner pipe and a spiral oil liquid passage provided on the outer peripheral portion of the inner pipe and extending spirally along the axial direction to form a spiral oil liquid passage between the inner pipe and the outer pipe. The water-cooled oil cooler is characterized in that the outer fin and the inner fin that is provided in the inner peripheral portion of the inner pipe and is spirally extended along the axial direction are integrally formed by extrusion molding. 2. The water-cooled oil cooler according to claim 1, wherein a plurality of inner fins and outer fins are provided, and the base end side on the inner pipe side is thicker than the front end side. 3. The water-cooled oil cooler according to claim 1, wherein the inner fin and the outer fin are arranged offset in the circumferential direction of the inner pipe. 4. The water-cooled oil cooler according to claim 1, wherein oil liquid reservoirs are provided at both ends of the oil liquid passage.