EP0861368A1

EP0861368A1 - Cooling and preheating process and system

Info

Publication number: EP0861368A1
Application number: EP97940120A
Authority: EP
Inventors: Winfrid Eckerskorn; Axel Temmesfeld; Heinz Lemberger; Christian Absmeier; Gerhart Huemer; Victor Brost; Klaus Kalbacher; Karl Schütterle
Original assignee: Bayerische Motoren Werke AG; Laengerer and Reich GmbH and Co
Current assignee: Bayerische Motoren Werke AG; Modine Manufacturing Co
Priority date: 1996-09-17
Filing date: 1997-08-23
Publication date: 1998-09-02
Anticipated expiration: 2017-08-23
Also published as: ES2146115T3; EP0861368B1; DE19637817A1; US6196168B1; DE59701435D1; WO1998012425A1

Abstract

A cooling and preheating system, in particular for gear oil in an internal combustion engine, has a compensating container, at least one radiator which can be switched on by an engine thermostat when a predetermined temperature in the cooling circuit is reached, and a water/oil heat exchanger. Also disclosed is a cooling and preheating process. In order to more effectively cool and preheat oil with a more compact and cost-effective design, the forward flow (1) of a single water/oil heat exchanger (5) in the heating phase can be branched off the main cooling circuit (12) of the internal combustion engine (17) by means of a valve unit (3), and the same forward flow (1) can be taken in the cooling phase essentially in the coolant secondary flow (13) by means of the same valve unit (3) from the low temperature area (14) of the radiator (4) or from a separate low temperature radiator (14a) connected in the secondary flow downstream of the radiator (4; 4a). The disclosed process provides for the forward flow (1) of the water/oil heat exchanger (5) to be taken in the heating phase essentially from the main coolant stream (12), which does not flow through the radiator (4). At a temperature slightly below the switching point of the main engine thermostat (9), the cooling mode is switched on. In the cooling mode, the forward flow (1) of the water/oil heat exchanger (5) is branched essentially off the low temperature area (14) of the radiator (4) or off another low temperature radiator (14a) connected in the secondary flow downstream of the radiator (4, 4a).

Description

Device and method for cooling and preheating 5 The invention relates to a device for cooling and preheating, in particular gear oil, an internal combustion engine. with an expansion tank, with at least one water cooler. which can be switched into the cooling circuit by means of a motor thermostat when a predetermined temperature is reached and with a water / oil heat exchanger. The invention further relates to a method for cooling and preheating. Oil cooling is often carried out by means of oil / air coolers using a thermostat which responds to corresponding oil temperatures. These solutions are Although quite effective with smaller radiator sizes, if the required cooling capacity and correspondingly larger radiators are required, in some operating states the temperatures are too low, which affects fuel consumption and the service life of the internal combustion engine.

1 affect machine negatively

For this reason, some time ago, the company started to optimize the oil temperature, i.e. to cool or heat it as required.To this end, an additional oil / water heat exchanger is integrated in the cooling circuit, which is switched on as required by a thermostat that responds to the oil temperature - or is often switched off

20 these thermostats can be activated with an electrical control. This solution group can provide optimized oil temperatures, but also has considerable costs on the plant side

Furthermore, the oil / water heat exchanger integrated in the normal water circuit for transmission oil cooling is used, which is often installed in a water box of the water cow

25 lers are arranged enclosed, but can also be provided separately. In this solution, only the cooling but not the preheating or heating is achieved

In DE-OS 41 04 093 the problem has been addressed that in the .Start phase of the internal combustion engine it is all about the rapid heating up of the passenger compartment as well as) the rapid achievement of the operating temperature of the engine and the transmission oil. To some extent these conflicting restrictions To be able to correspond better, a cooling management system has been presented here, in which a microprocessor is to influence the performance of the different heat exchangers on the basis of signals from a number of temperature sensors in the various circuits 5. This system appears to be quite expensive and to have a complicated and therefore also fragile technical structure Based on the prior art set out, the object of the invention is to provide an efficient, compact and inexpensive device for cooling and preheating operating materials, in particular gear oil, for internal combustion engines, with which both drafty warming of the gear oil in the starting phase of the engine Without significantly impairing the heating of the passenger compartment, more efficient oil cooling is also possible without having to use additional air-cooled or water-cooled oil coolers. Furthermore, an associated method for cooling and heating is to be specified. This object is achieved according to the invention with the features specified in the claims

The device according to the invention has only a single water / oil heat exchanger which can be used both for heating and for cooling operating materials, in particular gear oil. For this purpose, a valve unit is provided which controls the flow of the heat exchanger mentioned. In the heating phase, the heat exchanger receives a cooling water flow which is branched off from the main cooling circuit which is quickly warmed up by the operation of the internal combustion engine. However, this amount is so small that the warming up of the internal combustion engine itself and the heating of the passenger compartment are hardly affected. In the cooling phase, on the other hand, the supply flow is essentially formed from the low-temperature range of the water cooler by means of the same valve unit in the secondary coolant flow. Due to the low temperature range, which can be achieved by means of an additional flow through part of the water cooler, the water / oil heat exchanger receives a cooling water flow which is about 10 ° C. lower, as a result of which the temperature difference oil to water increases and the cooling effect is improved the separate low-temperature cooler allows even higher temperature differences to be achieved. There is also the possibility of a space-saving arrangement that is independent of the water cooler. At a temperature of around 80 to 90 ° C there is a transition area between the heating phase and the cooling phase, in which the flow of the heat exchanger from the expansion tank with that from the low temperature range Water cooler or alternatively mixed from the separate low temperature cooler. Thus, both the gear oil Cooling in all operating situations and heating only possible with this one heat exchanger

In addition, the oil temperature is optimized by adding a flow from the low temperature range of the water cooler or from the separate low temperature cooler to a minimal continuous flow from the expansion tank, i.e. a flow of higher temperature. Too low oil temperatures with their negative consequences, as they are in particular with oil / air cooling over large driving ranges are avoided. The low temperature range of the water cooler is realized, as is known per se, by arranging at least one partition in at least one water tank, which divides part of the water flowing through the water cooler into a u- shaped or meandering flow through the water cooler. In the water box, within the low temperature range, an additional connection is also provided, which is connected to the flow channels to the oil-water heat exchanger via a valve unit Flow channels for the heat exchanger are formed, one of which is switchable in connection with the low temperature range of the water cooler or with the separate low temperature cooler and the other is in connection with the expansion tank. The housing, which includes the valve unit, preferably consists of an upper and a lower receptacle, which are joined together by means of a quick-plug connection. The upper receptacle is molded directly into the bottom area of the surge tank and the lower receptacle forms a single plastic injection molded part with the flow channels of the heat exchanger. In addition, the return channel of the heat exchanger and the return connection of the expansion tank and the return pipe leading to the coolant pump are also designed as a uniform injection molded component. All of these features mean that a compact design is achieved, since the components mentioned are to be fastened in the immediate vicinity, for example to the fan hood enclosing the water cooler. Lines requiring space are therefore unnecessary. All media connections are designed as quick-plug connections, which have a favorable effect on assembly and disassembly

Claims 13 to 16 are directed to a method for cooling and preheating, with which the efficiency of the cooling and preheating is to be improved. It has proven to be particularly effective if the switching point of the valve unit to cooling operation is negligible, approximately 5 ° C. below the switching point of the engine main thermostat The overall conclusion is ^that the dynamic control process cooler location or by to ischung w ^ä poorer Kuhlwassers over the entire control range in bes _t he _i se We affected is

For further erf.ndungswesentlicher features is the patent claims _{above sea} surface referred Other advantages of the invention will become apparent from the following fuhrungsbeispielen Beschre.bung of Aus _¬ This is made to FIGS respect FIG

1 shows a schematic circuit diagram of the cooling phase of a transmission oil cooler. FIG. 2 shows a schematic circuit diagram of the heating or preheating phase. FIG. 3 shows a schematic circuit diagram in a transition phase

Fig. 4 water cooler (schematic) which has a partition in a water tank to form a low temperature range.

Figure 5 m ⁱ t Break fluid receiving socket with inserted Thermostatventii and Ka _¬ ^ä n len coupler for indicated Getriebeolkuhler and to the low-temperature range of the Wasserkuh-

Figure 6 housing forming receiving socket as Einzelhei _t Fig. 7 schematic circuit diagram of a separate low-temperature radiator in Figs 1 b ⁱ s 3 of the prince is shown ⁱ Pielle Kuhlwasserkreislauf as beispielswe.se to C ^ooling an internal combustion engine 17 in a vehicle can be found. Components of the circuit are the water block 4, the Break fluid 2, the motor thermostat 9 and the Kuhlmittelpumpe 8 During a cold start internal combustion engine 17, the Hauptkuhl _¬ m ⁱ ttelstrom 12 m ⁱ ttels the engine thermostat 9 on a short path, with the elimination of the Wasserkuhlers 4, d ^{i led} back to the internal combustion engine 17 In the right part of FIGS. 2 and 3, the image ⁱ is shown. The internal combustion engine 17 heats the cooling water in a short time. The W ^ä rmeenergie of Kuhlwassers can be used for example for the Au _l heating of the passenger _¬ space, after which in the present case will not be discussed st In addition ⁱ in the cycle, a single oil / water heat exchanger _5, for example, a Getriebeolkuhler, integrated whose forward stream 1 by means of a valve unit 3 adjustable ⁱ st. The valve unit 3 has a terminal for Niedeπemperaturbereich 14 of the water _¬ ready kuhlers 4 and a further connection to Break fluid 2 in the Kuhlphase, as shown in Fig. I, for example at a Kühlwasseπemperatur of 110 ° C, the motor _¬ has thermostat 9 the short path bere ⁱ ts abgesperπ so that the main cooling circuit 12 proceeds through the water block 4 and ^ü ck to 8 Kuhlmittelpumpe also, since the valve unit has abgesperπ the way to Break fluid 2 3 - except for a small constant current - is the flow stream 1 of the heat exchanger 5 essentially from the low temperature range 14 of the water cooler 4. This low temperature range 14 allows the water temperature to be further cooled, for example by 10 ° C., which is advantageous for the transmission oil cooling. FIG. 4 shows how this low-temperature range is formed, which will be discussed in more detail below.

2 shows the pure preheating phase of the heat exchanger 5, in which the flow stream 1 is removed from the expansion tank 2, through which part of the main coolant flow 12 flows. The valve unit 3 has opened the inlet on the left in the figure and closed the right inlet leading to the low temperature range! 4. A part of the cooling water quickly warmed up by the internal combustion engine 17 is thus provided for the rapid heating up of the transmission oil.

For example, in a temperature range between 80 and 85 ° C., slightly before the action temperature of the motor thermostat 9, which could be 90 ° C., a transition range has been established, as shown in FIG. 3. In this temperature range, the flow stream 1 of the heat exchanger 5 comes both from the expansion tank 2 and from the low temperature range 14, which in turn is useful for optimizing the oil temperature. Another operating situation, not shown, occurs when the temperature continues to rise, even if the engine thermostat 9 is already partially open, the low temperature range 14 then only being flowed through by a subset of the water flowing through the water cooler 4, as is in principle also shown in FIG 1 is recognizable.

The schematic water cooler 4 is shown in FIG. 4. In this water cooler 4, a low temperature range 14 is separated by using a partition 16 in the left water box 15, which causes the water or part of the water to flow through the water cooler 4 again in the opposite direction and thereby cool down by an additional amount. The main coolant flow 12 or a part thereof enters the water cooler 4 at the top left at the inlet connection 22 and leaves it after flowing through on the right side at the outlet connection 23 according to the arrow shown. The portion flowing through the low-temperature region 14 forms the secondary coolant flow 13, which leaves the water cooler 4 at the bottom left in order to enter the flow channel designated 10, which leads to the heat exchanger 5. On the water tank 15, within the low temperature range 14, a connection piece 24 for connection to the flow channel 10 is shown in a schematic form.

The flow channel 10 is also shown in FIGS. 5 and 6, which show an expansion tank 2 with a schematic valve unit 3 located in the bottom 21. The valve unit 3 is located in an insert housing 19, which consists of a lower 18 and an upper receptacle 20. These sockets are preferably made of plastic. The lower receiving nozzle 18 forms a single component together with the flow channel 10, which comes from the low temperature region 14 and the flow channel 11, which leads from the receiving nozzle 18 to the flow connection of the heat exchanger 5. In the same way, the return channel 28 from the heat exchanger 5 with the return connection 29 of the expansion tank 2 and the return pipe 30, which represents the connection to the return to the cooling water pump 8, forms a single injection molded part made of plastic. The arrows drawn in FIG. 5 indicate the flow through the expansion tank 2 and the channels 10; 1 1; 28; 29 on. During the heating phase, the part of the area made clear with the upper horizontal arrow occurs

Main coolant flow 12 into the expansion tank 2. Part of the latter is branched off by means of the valve unit 3 and fed to the transmission oil cooler 5 via the flow channel 11. The water leaves the transmission oil cooler 5 via the return channel 28 and returns to the circuit. In the cooling phase, the cooling water comes from the low-temperature region 14 via the flow channel 10, into the flow channel 11, into the transmission oil cooler 5 and leaves it as described. In the transition area, the flow stream 1 is controlled by means of the valve unit 3 so that part of the cooling water is fed via the channel 10 from the low-temperature area 14 and another part from the expansion tank 2 into the flow channel 11. 6 shows the already described essential details of the housing 19 accommodating the valve unit 3, the valve unit 3 itself, for the sake of clarity, not being drawn but merely indicated by the reference number 3. The two parts of the housing 19, the lower receptacle 18 and the upper receptacle 20, which is part of the expansion tank 2, are sealed to the outside by means of a suitable seal 32. The connection is made through slots or groove 31 on the wall, in which there is a spring clip, which was not shown in the drawing. The arrows indicate the flow of the water. This illustration also shows the compact design which dispenses with separate lines, in which the lower receiving connector 18 and the flow channels 10 and 11 are designed as a single injection-molded part. Since the upper receptacle 20, as already described, is formed directly in the bottom 21 of the expansion tank 2, the number of individual parts is extremely small, which contributes to ease of installation.

In the variant according to FIG. 7, in which the low-temperature region 14 has been omitted and has been replaced by the separate low-temperature cooler 14a, the advantage arises that Larger temperature differences for oil cooling can be achieved. This variant can also be advantageous if, for reasons of space, the water cooler 4 with the low temperature area 14 cannot be accommodated. A smaller water cooler 4a can be provided for this purpose, and the separate low temperature cooler 14a can be arranged where there is space, for example in allow a motor vehicle, like FIG. 1 already explained, FIG. 7 shows the pure cooling phase in which the main coolant flow 12 is passed through the water cooler 4a. The arrows drawn a little more forcefully show the flow path of the cooling water prevailing in this phase. The low-temperature cooler 14a is connected downstream of the water cooler 4a and lies parallel to it. The water flowing into this cooler 14a reaches the valve unit 3 and from there into the gear oil cooler 5, where efficient oil cooling is possible due to the large temperature difference.

List of the reference symbols used

1 flow of 5

2 reservoirs

Thermostatic control valve unit

4 water coolers

4a water cooler

5 heat exchangers (oil-water cooler)

6 return flow of 5

7 coolant line

8 coolant pump

9 Engine main thermostat

10 flow channel from 4 (14) to 5

1 1 flow channel from 2 to 5

12 main cooling circuit

13 coolant bypass

14 low temperature range of 4

14a low-temperature cooler

15 water boxes of 4

16 partition in 15

17 B internal combustion engine

18 adapters, below

19 operational housing for 3

20 adapters, on top of the expansion tank 2

21 Bottom of the expansion tank 2

22 inlet spigot on 4

23 outlet spigot on 4

24 connecting pieces to 14

25 flat tubes

26 slats

27 dividing line for low temperature range 14

28 return channel of 5

29 return connection to 2 Return pipe groove for spring clip seal

Claims

PATENT CLAIMS

1. Device for cooling and preheating, in particular gear oil, in internal combustion engines for vehicles, with an expansion tank, with at least one water cooler that can be switched on by means of a motor thermostat when a predetermined temperature is reached in the cooling circuit and with water / oil heat exchanger, thereby characterized in that the flow (1) of a single water / oil heat exchanger (5) in the heating phase can be branched off essentially from the main cooling circuit (12) of the internal combustion engine (17) by means of a valve unit (3) and that its flow (1) in the cooling phase by means of the same valve unit (3) essentially in the secondary coolant flow (13) from the low temperature range (14) of the water cooler (4).

2. Device for cooling and preheating, in particular gear oil, in internal combustion engines for vehicles, with an expansion tank, with at least one water cooler which can be switched on in the cooling circuit by means of a motor thermostat when a predetermined temperature is reached and with a water / oil heat exchanger, characterized in that that the flow (1) of a single water / oil heat exchanger (5) in the heating phase can be branched off essentially from the main cooling circuit (12) of the internal combustion engine (17) by means of a valve unit (3) and that its flow (1) in the cooling phase by means of the same valve unit (3) essentially from the low-temperature cooler (14a) arranged in the secondary coolant flow (13) of the water cooler (4 or 4a).

3. A device for cooling and preheating according to claim 1, characterized in that a part of the main cooling circuit (12) in the heating phase is passed through the expansion tank (2), from there a portion can be branched off by means of a Veπtil unit (3) and as a flow (1) The heat exchanger (5) can be fed in that in the cooling phase the main cooling circuit (12) is led through the water cooler (4), which has at least one partition (16) forming a low-temperature region (14) in at least one of its water boxes (15), that the water flowing through the low-temperature region (14) can be fed to the heat exchanger (5) by means of the valve unit (3) as flow flow (1), and that the return flow (6) of the heat exchanger (5) in both phases into the line (7) Coolant pump (8) is fed.

4. Device for cooling and preheating according to claim 2, characterized in that a part of the main cooling circuit (12) in the heating phase is guided through the expansion tank (2), from there a portion can be branched off by means of a valve unit (3) and as a flow (1) the heat exchanger (5) can be fed in that in the cooling phase the main cooling circuit (12) is guided through the water cooler (4a), which is followed by a low-temperature cooler (14a) lying in the bypass flow, from which the flow stream is by means of the valve unit (3) (1) the heat exchanger (5) can be fed, and that the return flow (6) of the heat exchanger (5) is fed in both phases into the line (7) to the coolant pump (8).

5. Device for cooling and preheating according to one of claims 1 to 4, characterized in that in a temperature range between the heating phase and cooling phase from the expansion tank (2) removable flow (1), a flow (1) from the low temperature range (14) Water cooler (4) or from the low-temperature cooler (14a) can be mixed.

6. Device for cooling and preheating according to claims 1 to 5, characterized in that the reaction temperature of the valve unit (3) is set below the reaction temperature of the engine main thermostat (9).

7. Device for cooling and preheating according to one of claims 1 to 6, characterized in that the valve unit (3) is in an insert housing (19) which is in connection with the expansion tank (2) and the two flow channels (10; 1st 1) to the heat exchanger (5), of which one flow channel (10) in connection with the low temperature area (14) of the water cooler (4) or with the low temperature cooler (14a) and the other flow channel (11) in connection with the expansion tank (2).

8. A device for cooling and preheating according to claim 7, characterized in that the insert housing (19) is formed from a lower (18) and an upper (20) Aufhah estutzen, which are sealingly pluggable into each other, that the upper receptacle (20) preferably is formed directly on the bottom (21) of the expansion tank (2) and that the lower receiving connector (18) together with the supply channels (10; 11) constitute a single component, preferably a plastic injection molded part.

9 device for cooling and preheating according to claim 8, characterized in that the valve unit (3) receiving the lower and upper receptacle (18, 20) are designed as m-pluggable and sealing quick-connector

10 Einπchtung for cooling and preheating according to claims 8 and 9, characterized in that the receptacle (20) on the surge tank (2) has an O-ring receiving groove inside and on its circumference has slots (31) for receiving a spring clip and that the receptacle (18) has a conical outer surface, which lies sealingly against the O-ring and has a circumferential groove (1) which receives the spring clip

11 device for cooling and preheating according to at least one of the preceding claims, characterized in that the return channel (28) of the heat exchanger (5) with the return connection (29) of the surge tank (2) in a common return pipe (30) mouth leads to the coolant pump (8)

12. Device for cooling and preheating according to claim 9, characterized in that the return channel (28), the return connection (29) and the return pipe (30) are a single component, preferably a plastic injection molded part

13 A method for cooling and preheating, in particular of gear oil, an internal combustion engine, characterized in that the flow (1) of the water / oil heat exchanger (5) in the heating phase essentially from the main coolant flow (12 or 4a) not flowing through the water cooler (4 ) that at a temperature slightly below the switching point of the main engine thermostat (9) the switchover to cooling mode takes place and in cooling mode the flow (1) of the water / oil heat exchanger (5) essentially from the low temperature range (14) the water cooler (4) or from a low-temperature cooler (14a) connected downstream of the water cooler (4 or 4a)

14 method for cooling and preheating according to claim 13, characterized in that from the current through the surge tank (2) a minimal continuous flow is withdrawn, which in the cooling phase increases with increasing temperature Electricity from the low temperature area (14) of the water cooler (4) or from the downstream low temperature cooler (14a) is added

15 A method for cooling and preheating according to claims 13 and 14, characterized in that after reaching the switching temperature with a further increase in the temperature of the cooling water, the .Share of the cooling water forming the flow stream (1) from the low temperature range (14) of the water cooler ( 4) or the low-temperature cow (14a) and is reduced as the temperature drops

16 A method for cooling and preheating according to one of the preceding claims, characterized in that after reaching the switching temperature with a further increase in the temperature of the cooling water, the proportion of the cooling water forming the flow stream (1) from the surge tank (2) or the water cooler (4) main coolant shaking flow (12) not flowing through and increased as the temperature drops