DE29719311U1 - Heat exchanger - Google Patents

Description

EN 7385

>·'Patent attorney Diploma physicist Reinfried Frhr. &ngr;. Schorlemer

Karthäuserstr. 5 A 34117 Kassel Germany

Telephone (0561) 15335

(0561)780031

Fax/Telecopter (0561)780032

Autokühler GmbH & Co. KG, 34369 Hofgeismar

Heat exchanger

The invention relates to a heat exchanger of the type specified in the preamble of claim 1.

In known heat exchangers of this type, the collecting boxes, which are usually made of a metal such as aluminum, are often made of one-piece round tubes for cost reasons (US-PS 48 25 941, WO 96/01973), in which specific slots are made to accommodate the pipe ends of the heat exchange network. Alternatively, it is known to provide the collecting boxes, which were originally designed as round tubes, with flat bottoms by means of a squeezing process or similar and to make specific openings in these to accommodate the pipe ends. In both cases, a cost-effective manufacturing process results. On the one hand, it is only necessary to insert the pipe ends of the heat exchange network into the slots or openings in the collecting boxes and to fasten them in a liquid- or gas-tight manner using mechanical means or by soldering or similar. On the other hand, the side ends of the collecting boxes can be closed by soldering or similar with prefabricated end plates that are provided with connections for the supply or discharge of the medium flowing through the pipes. If the connections are not to be installed on the sides but in the middle areas of the collecting boxes (US-PS 5 190 101), further work steps are required to provide the walls of the collecting boxes with appropriate openings and to insert prefabricated connection pieces into these by soldering or similar.

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to fasten by welding.

While the procedure described has various advantages for the series production of heat exchangers manufactured in large numbers, it is comparatively complex for the production of small series. This is especially true if the heat exchangers are to be equipped with additional components such as thermostats, as this requires additional work steps, for example to connect the thermostats to the manifolds.

The invention is therefore based on the object of designing a heat exchanger of the type specified in the preamble of claim 1 in such a way that it can be easily provided with connections even in central areas and can be manufactured optionally with or without additional components.

The characterizing features of claim 1 serve to solve this problem. Further advantageous features of the invention emerge from the subclaims.

The invention is explained in more detail below in conjunction with the accompanying drawings using an exemplary embodiment. They show:

Fig. 1 to 3 show, in an exploded view, the front view, side view and top view of a heat exchanger according to the invention;

Fig. 4 to 6 show views corresponding to Fig. 1 to 3 but on a smaller scale, of the heat exchanger in the assembled state;

Fig. 7 and 8 each show a view corresponding to Fig. 4, but slightly enlarged, through a heat exchanger additionally provided with a thermostat, otherwise designed analogously to Fig. 1 to in two different operating states; and

Fig. 9 and 10 each show a cross section through an insert piece of the heat exchanger according to Fig. 7 and 8 along the line DC-IX of Fig. 7.

Fig. 1 to 6 show a heat exchanger network 1 and a tubular collecting box 2 as essential components of a heat exchanger according to the invention, which can be used, for example, as an oil or water/air heat exchanger for motor vehicles. The heat exchanger network 1 contains several parallel pipes 3 through which oil, water or the like can flow, for example, and which preferably have oval, flat-oval or other cross-sections. Lamellar bodies (not shown) can be inserted into the pipes 3, which act as turbulators in a known manner. Zigzag-shaped lamellae 4 are expediently arranged between the pipes 3 to guide the air. Alternatively, the pipes 3 could also be provided with plate-shaped guide plates pulled onto them. The tubes 3, fins 4 and other components are preferably made of a metal, in particular aluminum, and are assembled by soldering or otherwise to form the finished heat exchanger network 1.

The collecting box 2 contains a pipe 5, which is also expediently made of metal, with a longitudinal axis 6, the metal preferably being the same metal, here for example aluminum, from which the heat exchanger network 1 is made. The pipe 5 can be designed as a round pipe, but is expediently provided with a flat base 7 running parallel to the longitudinal axis 6 and obtained by a squeezing process or the like, as shown in particular in Fig. 2. In the base 7, according to Fig. 3, there are provided openings or apertures 8 arranged parallel to one another, possibly provided with collars, which have cross-sections corresponding to the ends of the pipes 3, also for example oval, flat oval or the like. The long diameters of the openings 8 are preferably arranged perpendicular to the longitudinal axis 6, and the cross sections of the openings 8 and/or pipe ends can correspond to the pipe cross sections in the heat exchanger network 1 or can also be shaped differently. The pipe ends protrude through the openings 8 into the collecting box 2 and are connected to it by soldering, expanding or otherwise.

At the side ends, the collecting box 2 is closed with end plates 9, which are also made of aluminum, for example, and are connected to the collecting box 2 by soldering. Especially when using solder-plated materials, it is therefore easy to manufacture the entire heat exchanger in one operation.

Heat exchangers of this type are generally known (US-PS 48 25 941, US-PS 51 90 101, EP 0 387 678 A1, WO 96/01973) and therefore do not need to be explained in more detail here.

According to the invention, the collecting box 2 has a recess 10 (Figs. 1 and 3) in a central area, which is preferably delimited by two semi-ring-shaped end surfaces 11 of the collecting box 2, spaced parallel to the longitudinal axis 6, and is formed, for example, by cuts that initially run perpendicularly and then parallel to the longitudinal axis 6, so that in the front view according to Fig. 1 and in the top view according to Fig. 3, a rectangular contour is formed for them. In Fig. 3, the bottom 7 of the collecting box 2 is also visible through the recess 10.

According to the invention, an edge section 2a of the collecting box 2, which surrounds the recess 10 and is indicated in Fig. 1 with a dotted line and borders the end faces 11, serves to support an insert 12, which is shaped accordingly at least in an area assigned to the edge section 2a and has a contour there that corresponds to the contour of the collecting box or the recess 10. At both ends, the insert 12 is provided with end faces 13 that correspond to the end faces 11, as shown in particular in Fig. 2. In the exemplary embodiment, the insert 12 is an essentially semi-cylindrical hollow body, which in the assembled state rests with an edge section on the edge section 2a in such a way that it completely covers the recess 10 and replaces the wall section of the collecting box 2 that is interrupted by the recess 10. The insert piece 12 preferably also consists of a metal, in particular aluminum cast part, which is brought closer to the collecting box 2 or its recess 10, for example in the direction of the arrows shown in Fig. 1 to 3, placed on the edge section 2a that borders it and then preferably connected to the collecting box 2 by welding. Fig. 1 to 3 show the arrangement of the collecting box 2 and the insert piece 12 before assembly, while Fig. 4 to 6 show the arrangement in the assembled state, with Fig. 3 and 6 being a top view starting from Fig. 2 and 5, respectively.

According to the invention, the insert 12 has a partition wall 15, which is indicated schematically in Fig. 1 and 2 and which divides the inner cavity of the insert 12 and, in the assembled state, also the collecting tank 2 into two liquid-tight chambers 16, 17 (Fig. 1). This partition wall 15 is arranged in the insert 12 in such a way that, in the assembled state, it is arranged perpendicular to the longitudinal axis 6 of the collecting tank 2. As a result, the liquid on one side of the partition wall 15 can be

the medium flowing into the collecting tank 2 or, for example, into the chamber 16 cannot reach the chamber 17 or the section of the collecting tank 2 located on the other side of the partition wall 15 directly. Rather, the medium must flow through the pipes 3 of the heat exchanger network 1 that protrude into the floor 7 on the side of the chamber 16, be diverted at their opposite ends (not visible in Fig. 1 to 6) and then flow back through the pipes 3 that protrude into the floor 7 on the side of the chamber 17, so that a U-shaped flow is produced. For this purpose, the pipe ends opposite the collecting tank 2 (not shown in Fig. 1 to 6) are connected to another collecting tank that appropriately corresponds to the collecting tank 2 but does not have a partition wall 15. Alternatively, it would also be possible to connect the pipes 3 intended for forward and return flow with each other by means of U-shaped pipe sections.

To supply and discharge the medium flowing through the heat exchanger network 1, the insert piece 12 is provided with a first connection 18, e.g. opening into the chamber 16, and with a second connection 19, e.g. opening into the chamber 17. Both connections 18, 19 consist, for example, of cast-on pipe sockets inserted into the insert piece 12, which are provided with external thread sections after the casting process, onto which the usual connection elements can be screwed.

As shown in Fig. 1 to 6, the two connections 18, 19 are arranged on the front of the heat exchanger in the embodiment. However, it would also be possible to arrange them on the back or partly on the front and partly on the back of the heat exchanger. The manufacturing method described has the advantage that the position of the connections 18, 19 in the insert piece 12 can be freely selected or that numerous different connection options can be created with insert pieces 12 that have differently arranged connections 18, 19 but are otherwise identical. It is also advantageous that collecting boxes 2 of different lengths can be realized with the same insert piece 12.

According to the invention, in addition to the intermediate wall 15 and the connections 18, 19, at least one further component suitable for the function of the heat exchanger can be integrated into the insert piece 12. This makes it possible to work with different

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different inserts 12 can also be used to implement different functions. This is indicated in the exemplary example for the particularly useful case of a thermostat 20 (Fig. 3,6,9,10).

In automotive engineering, a thermostat is a component that temporarily prevents a medium from flowing through a heat exchanger assigned to it. In the case of a motor vehicle with an internal combustion engine, for example, it is usual not to allow the water or oil to be cooled to flow through the associated heat exchanger when the motor vehicle is started, so that it constantly flows around the engine and thus quickly reaches the operating temperature. In this state, the thermostat is "closed". Once the operating temperature has been reached, the thermostat is "opened" so that the water or oil can now flow through the associated heat exchanger and thus be cooled in the desired manner.

Heat exchangers of a conventional design have a valve with a valve body that opens or closes a passage, which is typically connected to an expansion element that moves the valve body into the open or closed state depending on the temperature, in which the valve body keeps an associated opening open or closed. Such thermostats are generally known in automotive technology and do not need to be explained in more detail.

In the heat exchanger according to the invention, the partition wall 15 is provided with an opening 21 as shown in Fig. 1, 3, 4, 9 and 10, which connects the two chambers 16, 17 with one another in terms of flow. The thermostat 20 integrated into the insert piece 12 has a valve body 22 (Fig. 9 and 10) associated with the opening 21, which closes the opening 21 in a first position, e.g. associated with the warm state of the medium (Fig. 9), but keeps it open in a second position, e.g. associated with the cold state of the medium (Fig. 10), with the transition of the valve body 22 into the closed position taking place, e.g. by an expansion element 23 (Fig. 9), while the creation of the open position is supported by a spring 24 when the expansion element 23 retracts.

The thermostat essentially works as follows:

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When the medium is cold, e.g. water or oil, the valve body 22 is in the position shown in Fig. 10, i.e. the opening 21 of the partition wall 15 is open. The medium flowing in through the connection can therefore pass directly from the chamber 16 of the insert piece 12 into its chamber 17 (see also Fig. 8) and from there flow through the connection 19 back to the engine or the like without flowing through the heat exchanger network 1. If, however, the medium has reached its operating temperature, the opening 21 is closed by the valve body 22 (Fig. 9). The medium must now flow from the chamber 16 through the pipes 3 connected to it to the other end of the heat exchanger network 1 and from there in a U-shaped flow back into the chamber 17 before it is discharged via the connection 19. The respective flow directions are indicated by arrows in Fig. 7 to 10, whereby in Fig. 9 a channel 25 indicates a connection of the chamber 16 to those pipes 3 which are attached to the same side of the partition wall 15 as the chamber 16 in the heat exchanger network 1. It is clear that when the opening 21 is closed, the medium can also interact with the associated pipes 3 of the heat exchanger network 1 via the sections of the collecting box 2 which are on the same sides of the partition wall 15 but outside the chambers 16, 17 of the insert piece 12, i.e. that the flow does not only have to take place through the pipes 3 which open into the chambers 16, 17.

The heat exchanger described has the particular advantage that in addition to the partition wall 15 and the connections 18, 19, the thermostat 20 is also integrated into the insert piece 12. It is therefore possible to offer the heat exchanger either with or without a thermostat, in that the insert piece 12 receives the partition wall 15 with the opening 21 when supplied with a thermostat, while when supplied without a thermostat a partition wall is provided that does not have the opening 21.

The invention is not limited to the embodiment described, which can be modified in many ways. For example, it is not necessary for the recess 10 to be arranged exactly in the middle of the collecting tank 2. The same applies to the partition wall 15. It would also be possible to provide the collecting tank 2 with several recesses 10 and a corresponding number of inserts 12 if, for example, it is desired to let the medium flow through the heat exchanger network 1 several times in a meandering flow in a known manner (e.g. US Pat. No. 4,825,941). In

In this case, a collecting box arranged opposite the collecting box 2, which is connected to the pipe ends (not shown), is either continuous or also provided with at least one insert piece 12 having a partition wall, depending on the desired function. Furthermore, the shape of the recess 10 is only an example, which can be changed in many different ways depending on the shape of the insert piece 12. The insert piece 12 itself can also have many different shapes as required. In this case, it is possible, for example, to arrange the insert piece 12 between the end faces 11 of the collecting box 2 in a way that deviates from the embodiment shown in the drawing, so that the end faces 11, 13 (Fig. 1) on the one hand and the longitudinal surfaces connecting them are each adjacent to one another along fine butt joints and are welded together. In this case, the insert 12 in this section would have essentially the same external contour as the wall section of the collecting box 2 cut out by forming the recess 10. It would also be conceivable to arrange the partition wall 15 parallel to the longitudinal axis 6 instead of perpendicularly, in contrast to Fig. 1 to 10, in which case, for example, the base 7 could be provided with two parallel rows of pipes 3, the ends of which each open into the collecting box 2 on one side of the partition wall, whereby the collecting box 2 would also have to be provided with wall sections running in the longitudinal direction, which extend the partition wall 15 parallel to the longitudinal axis 6. In addition, the insert 12 could in this case be arranged at one of the ends of the collecting box 2. It is also expedient to provide the partition wall 15 according to Fig. 1 and 2 with a projection 26 protruding from the insert piece 12, which in the assembled state is placed on the base 7 between two pipe ends opening into the collecting box 2 (Fig. 4), whereby a tight closure or a tight separation of the chambers 16, 17 can be achieved in a simple manner. Finally, it is clear that the various features can also be used in combinations other than those described and shown in the drawing.

Claims (10)

Expectations 1. Heat exchanger with tubes (3) having tube ends and a tubular collecting box (2) connected in a sealed manner to the tube ends, which contains connections (18, 19) for a medium intended to flow through the tubes (3) and is divided into two separate chambers (16, 17) by a partition wall (15), characterized in that the collecting box (2) has a recess (10) which is covered by an insert piece (12) provided with the connections (18, 19) and the partition wall (15). 2. Heat exchanger according to claim 1, characterized in that at least one further component is integrated into the insert piece (12). 3. Heat exchanger according to claim 2, characterized in that the further component is a thermostat (20). 4. Heat exchanger according to claim 3, characterized in that the partition wall (15) has an opening (21) and the thermostat (20) is provided with a valve body (22) associated with the opening (21). 5. Heat exchanger according to one of claims 1 to 4, characterized in that the insert (12) consists of a cast metal part. 6. Heat exchanger according to claim 5, characterized in that the collecting box (2) consists of a metal and the insert (12) is connected to the collecting box (2) by welding. 7. Heat exchanger according to one of claims 1 to 6, characterized in that the collecting box (2) is closed at its ends with end plates (9). 8. Heat exchanger according to one of claims 1 to 7, characterized in that the collecting box (2) has a substantially flat base (7) and consists of one piece therewith. 9. Heat exchanger according to claim 8, characterized in that the bottom (7) is provided with
openings (8) to accommodate the pipe ends. 10. Heat exchanger according to one of claims 1 to 9, characterized in that the insert (12) has a peripheral edge section with which it can be mounted on a
also circumferential edge portion (2a) of the
collecting box (2).