GB1580597A

GB1580597A - Heat exchanger tank interconnection

Info

Publication number: GB1580597A
Application number: GB1651278A
Authority: GB
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 1977-04-30
Filing date: 1978-04-26
Publication date: 1980-12-03
Also published as: IT7821663V0; FR2389306A7; ES235689Y; ES235689U

Description

(54) A HEAT EXCHANGER TANK INTERCONNECTION (71) We, SUDDEUTSCHE KUHLERFABRIK JULIUS FR. BEHR GMBH. & Co. KG a Company organised under the laws of the Federal Republic of Germany of Mausterstrasse 3, D-700 Stuttgart 30, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a heat exchanger arranged in a tank adapted to contain a cooling medium, and particularly to means for interconnecting the heat exchanger and the tank.

It is known to arrange, for example oil coolers for internal combustion engines of vehicles, in a tank containing a cooling medium (typically water) for the cooling medium circuit - of the internal-combustion engine.

Such heat exchangers may be used for cooling the engine lubricating oil or the transmission oil in automatic transmisisons.

As heat exchangers in such cases, double tube heat exchangers may be used, in which two mutually nested tubes are provided in the cooling medium tank, in the annular envelope space of which swirl inlays are arranged. These heat exchangers are provided with inlet and outlet connections penetrating the cooling medium tank in order to form the cooling medium circuit for the lubricating oil or the transmission oil.

The sealing of the penetration points of the inlets and outlets for the heat exchanger tubes in the associated cooling medium tank presents considerable difficulties.

It is known to provide sealing inlays and to tighten the pipe connection against the wall of the cooling medium tank by means of a nut. It is also known to solder the connecting surfaces of the connection of the heat exchanger tubes to the wall of the cooling medium tank.

In a known cooling device, the connections provided on the heat exchanger and penetrating the wall of the cooling medium tank each consist of at least two parts, whilst upon assembly they form between themselves an annular space, the volume of which can be reduced during assembly, in order to compress from practically all sides a soft seal arranged in said annular space and overlapping the edge of the recess and to enclose the same.

However, these known constructions are structurally complicated and require a substantial outlay for assembly.

According to the present invention there is provided a heat exchanger arranged in a tank adapted to contain a cooling medium, the exchanger having an inlet and an outlet connection, each connection penetrating an associated aperture in a wall of the tank and having an annular stop bead of a diameter to pass through the aperture and a spring washer provided with spring washer teeth distributed uniformly upon its inner circumference, the spring washer teeth of each spring washer being engaged with the associated stop bead so that the spring washer provides a resilient force between the stop bead and the wall of the tank to urge a stop face of each connection against an inner face of the wall of the tank in the region of the associated aperture.

Thus each spring tooth washer provides a resilient connection in which the danger of damage to the heat exchanger in the tank due to excessive tightening of a nut is eliminated.

It is particularly advantageous according to a further preferred feature of the invention if an annular seal is arranged in a groove of the stop face of each connection abutting the inner face of the tank wall.

According to a preferred embodiment of the invention, at least the spring washer teeth of the spring washer are angled frusto conically towards the centre of the washer.

According to yet another preferred embodiment of the invention, each tooth is further angled in its inner terminal region. each Preferably, each connection has a cylindrical preliminary centring section which is axially adjacent the stop bead, each stop bead having as top surface serving as an abutment for the spring washer teeth.

The stop surface may form an annular groove with a frusto-conical surface of each connection. In this case the angle of inclination of the frusto-conical surface of the annular groove is preferably smaller than the angle of inclination of the terminal regions of the spring washer teeth.

A secure engagement of the ends of the spring washer teeth in the annular groove is effected by this configuration.

Rust-resistant spring steel is preferably used for the material for the spring washer.

A preferred embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 shows a partly sectional view through part of a cooling medium tank with a heat exchanger according to the invention, Fig. 2 shows an end elevation of the embodiment shown in Fig. 1, Fig. 3 shows a sectional view of part of Fig. 1 on a larger scale, Fig. 4 shows a spring tooth washer, and Fig. 5 shows a sectional view of part of the washer shown in Fig. 4 on a larger scale.

In the embodiment illustrated in Fig. 1, a part of a tank 1, which comprises a water tank which forms part of a cooling medium circuit of an internal-combustion engine (not shown) is illustrated. A heat exchanger 2 is arranged in the tank 1, and in the embodiment illustrated is constituted by an outer pipe 19 and an inner pipe 20 arranged concentrically therewith. At the end of the heat exchanger 2 the annular space between outer tube 19 and inner tube 20 is closed, by reducing gradually the diameter of the free end of the outer tube 19 until the reduced diameter corresponds to the external diameter of the inner tube 20, whereupon the two tubes are soldered fluid-tightly.

The inner tube 20 surrounds an interior space 22, through which the cooling medium (water) of the internal-combustion engine cooling circuit also flows. The oil to be cooled, e.g., lubricating oil of the internalcombustion engine or transmission oil of an automatic transmission, is fed into the annular space between the outer tube 19 and the inner tube 20 and is thus cooled by the water. The heat exchanger 2 is of elongate construction and has adjacent both its ends an inlet connection 3 and an outlet connecton 4. These connections penetrate a wall 5 of the tank 1 through an aperture 6.

The outer tube 19 is provided with a connection part 24 which is soldered fluidtightly to the inlet connection 3 or to the outlet connection 4.

The connection 3 or 4 abuts with a stop face 10 against the inner face 11 of the wall 5 of the tank 1. For better sealing, a seal 13, in the form of an O-ring, is arranged in a groove 12.

In order to draw or to press the stop face 10 of the connection 3 or 4 firmly against the inner face of wall 5 a spring washer 9 is provided which has spring washer teeth 8 distributed uniformly upon its inner circumference. The connection 3 or 4 terminates in a screw threaded section 23 to which an associated pipe can be screwed. It is also possible to attach a pipe or a hose to the section 23 by means of a hose clip. The section 23 merges in the axial direction into an approximately cylindrical preliminary centring section 15. The preliminary centring section 15 (see Fig. 3) is adjoined by a stop bead 7. The stop bead 7 has a stop suface 16 confronting the wall 5 of the tank 1, which merges into a conical surface 17. Stop surface 16 and conical surface 17 form an encircling annular groove 18. The spring washer teeth 8 engage in said annular groove 18.

Fig. 2 illustrates an end elevation of the embodiment according to Fig. 1, from which the construction and arrangement of the spring washer teeth 8 of the spring washer 9 are clear.

Fig. 3 in conjunction with Fig. 5 shows that the spring washer 9 comprises an external plane annular part from which the spring washer teeth 8 project towards the centre of the washer at uniform intervals.

Said spring washer teeth 8 merge into a terminal region 14 which forms a more acute angle with the axis 21 of the spring washer 9 than the initial part of the spring washer teeth 8. The contact pressure derived from the teeth 8 is thus uniformly distributed over the circumference of the connections 3 and 4.

As is clear, particularly from Fig. 4, the spring washer 9 is of conically domed construction. This results in very great elasticity and particularly powerful tensioning force when the teeth 8 are displaced, when engaged in the groove 8. The connections 3, 4 (in Figs. 1 and 3) are thus urged towards the right-hand side so that the associated stop face 10 is urged firmly against the inner face 11 df the tank 1.

The fitting of the spring washer 9 can be performed comparatively simply, for example, by screwing an assembly nut onto the screw threaded section 23 of the connection 3 or 4 and urging the spring washer 9 against the wall 5 with a sleevelike component until the spring washer teeth 8 engage in the annular groove 18. As will be seen more particularly from Fig. 3, it is advantageous if the angle of inclination of the conical surface 17 of the annular groove 18 is smaller then the angle of inclination of the terminal ends 14 of the spring washer 8. The terminal ends 14 of the spring washer teeth 8 are thereby prevented from slipping out of the annular groove 18 accidentally.

A further advantage of the construction according to the invention results from the fact that, when used in a water tank of a cooling system, the connection to the heat tank end part is immediately possible by flanging, including in the region of the connections 3 and 4. In the case of the known arrangement of nuts and screw connections intermediate working steps are necessary because it is not immediately possible to screw the nuts on in the region of ffangings or to flange the water tank end in the region of the nuts. The spring washer 9 according to the invention is preferably produced from stainless, that is rust resistant, spring steel.

The cylindrical preliminary centring section 15 of the conneqtions 3 and 4 facilitates the central positioning of the spring washer 9, so as to ensure that the contact pressure of the spring ring 9 is of uniform value about the entire circum reference.

WHAT WE CLAIM IS:- 1. A heat exchanger arranged in a tank adapted to contain a cooling medium, the exchanger having an inlet and an outlet connection, each connection penetrating an associated aperture in a wall of the tank and having an annular stop bead of a diameter to pass through the aperture and a spring washer provided with spring washer teeth distributed uniformly upon its inner circumference, the spring washer teeth of each spring washer being engaged with the associated stop bead so that the spring washer provides a resilient force between the stop bead and the wall of the tank to urge a stop face of each connection against an inner face of the wall of the tank in the region of the associated aperture.

2. A heat exchanger according to claim 1, wherein an annular seal is arranged in a groove of the stop face of each connection.

3. A heat exchanger according to claim 1 or 2, wherein at least the spring washer teeth of each spring washer are angled frusto-conically towards the centre of the washer.

4. A heat exchanger according to claim 3, wherein each tooth is angled in its inner terminal region.

5. A heat exchanger according to any one of claims 1 to 4 wherein each connection has a cylindrical preliminary centring section axially adjacent the stop bead and a stop surface on the stop bead serving as an abutment for the spring washer teeth.

6. A heat exchanger according to claim 5, wherein each stop surface forms an annular groove with a frusto-conical surface of each connection.

7. A heat exchanger according to claim 6, wherein the angle of inclination of the frusto-conical surface of the annular groove is smaller than the angle of inclination of the terminal regions of the spring washer teeth.

8. A heat exchanger according to any one of the preceding claims, wherein each spring washer is formed of frusto-resistant spring steel.

9. A heat exchanger arranged in a tank adapted to contain a cooling medium, substantially as described herein with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. connection 3 or 4 and urging the spring washer 9 against the wall 5 with a sleevelike component until the spring washer teeth 8 engage in the annular groove 18. As will be seen more particularly from Fig. 3, it is advantageous if the angle of inclination of the conical surface 17 of the annular groove 18 is smaller then the angle of inclination of the terminal ends 14 of the spring washer 8. The terminal ends 14 of the spring washer teeth 8 are thereby prevented from slipping out of the annular groove 18 accidentally. A further advantage of the construction according to the invention results from the fact that, when used in a water tank of a cooling system, the connection to the heat tank end part is immediately possible by flanging, including in the region of the connections 3 and 4. In the case of the known arrangement of nuts and screw connections intermediate working steps are necessary because it is not immediately possible to screw the nuts on in the region of ffangings or to flange the water tank end in the region of the nuts. The spring washer 9 according to the invention is preferably produced from stainless, that is rust resistant, spring steel. The cylindrical preliminary centring section 15 of the conneqtions 3 and 4 facilitates the central positioning of the spring washer 9, so as to ensure that the contact pressure of the spring ring 9 is of uniform value about the entire circum reference. WHAT WE CLAIM IS:-

1. A heat exchanger arranged in a tank adapted to contain a cooling medium, the exchanger having an inlet and an outlet connection, each connection penetrating an associated aperture in a wall of the tank and having an annular stop bead of a diameter to pass through the aperture and a spring washer provided with spring washer teeth distributed uniformly upon its inner circumference, the spring washer teeth of each spring washer being engaged with the associated stop bead so that the spring washer provides a resilient force between the stop bead and the wall of the tank to urge a stop face of each connection against an inner face of the wall of the tank in the region of the associated aperture.