DE2916216A1 - Preheating system for IC engine - stores waste heat as latent heat and uses salt solution changing from crystalline to liquid form releasing heat to oil circuit - Google Patents

Abstract

The preheating system for an internal combustion engine stores the waste heat obtd. when the engine is in operation. It uses a latent heat store, which functions as a heat exchanger to supply or absorb the necessary energy. It also includes a switch to release the required heat. The latent heat store is incorporated in the coil circuit. The latent heat store (6) uses a salt solution, which changes from a crystalline form to a liq. form thus releasing the latent heat. The heat is given off to the coil circuit of the engine via the oil pump (4) driven by a motor (15), which pumps lubricating oil whose viscosity will be reduced. This will therefore reduce the consumption of the starter.

Description

Device for heating parts of an internal combustion engine

PRIOR ART The invention is based on a device according to FIG the genre of the main claim. In a known device it is proposed from a heat-insulated storage tank for warm cooling water to preheat the internal combustion engine take hot water at the start of the same. This facility has the disadvantage that the stored warm water is not completely shielded against cooling losses can be so that the storage time is very limited. The necessary isolation measures also require a considerable effort and a considerable size of the memory. There are other heating devices for internal combustion engines or parts thereof known, in which an additional energy is used for the warming, which in the desired Instant is converted into heat. This can be in the form of a flame tube heater or be realized in the form of an electric heater. These bodies have the disadvantage that in internal combustion engines for operating motor vehicles the necessary electrical energy independently, usually in electrical Batteries, must be provided, which again is a considerable effort means.

Heating with flame tube systems also requires the necessary Regulation also of the provision of additional energy to the operating reserve the internal combustion engine is lost. Such a solution is also very complex and only applicable to a limited extent (intake manifold heating) in the internal combustion engine.

It is also known to use latent heat storage in solar energy collector systems to use, which are supercoolable, and their stored heat with the help of a Start device can be released at any time (DE-OS 26 19 514, U.S. Patent 3,952,519).

Advantages of the Invention The. device according to the invention with the characteristic Features of the main claim has the advantage that when the internal combustion engine is warm Heat given off to the storage tank can be kept for a very long time without cooling losses can and on request after actuating a starting device again to the meanwhile cooled internal combustion engine can be delivered.

The measures listed in the subclaims are advantageous Further training and improvements of the facility specified in the main claim possible.

DRAWING Eight exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it Fig. 1 shows a first embodiment with a latent heat storage> in one ö1 circuit is arranged, the part of the lubricating oil circuit of the internal combustion engine Fig. 2 shows a second exemplary embodiment with a latent heat store contained Oil circuit, in which also an intake pipe heat exchanger and an oil spray system in the cylinder head cover space are arranged, Fig. 3 shows a third embodiment with optional shutdown the spray device according to the embodiment of FIG. 2 and supply to the engine block the internal combustion engine with lubricating oil heated by the latent heat accumulator, FIG. 4 fourth embodiment with a cooling water circuit connected in a heating system Latent heat storage and with a switch valve to limit this cooling water circuit on the cylinder head and / or an intake pipe heat exchanger, FIG. 5 a modified one Embodiment of the embodiment according to FIG. 4 with an additional pump for a cooling water circuit containing the cylinder head and the latent heat accumulator, 6 shows a function diagram for the actuation of the switching valve in the exemplary embodiment according to Fig. 4, Fig. 7 a modified embodiment of the control of the switching valve according to the embodiment according to FIG. 4, FIG. 8, a function diagram for the control of the switching valve according to the embodiment according to FIG. 7, FIG. 9 shows a function diagram for the embodiment according to Fig. 5, Fig. 10 a seventh embodiment of the invention with a latent heat storage, which is in thermally conductive contact with a heat transfer zone of the wall of the suction pipe the internal combustion engine is at a standstill and the exhaust gas flows through it for reheating, 11 shows a section through the embodiment according to FIG. 10, FIG. 12 shows a modified one Embodiment of the embodiment according to FIG. 10 with an upstream Catalyst in the connection line to the exhaust manifold and FIG. 13 shows a section by the embodiment according to FIG. 12.

Description of the exemplary embodiments In Fig. 1 is a schematic Internal combustion engine 1 and its lubricating oil circuit are shown. The lubricating oil cycle has a lubricating oil reservoir 2, which in the usual way as oil pan closes the crankcase of the internal combustion engine at the bottom. Furthermore is an oil pump 4 is provided in the lubricating oil circuit, which supplies the lubricating oil to the lubricating oil reservoir removes and via a check valve 5 through a latent heat accumulator 6 and from there to the lubrication points 7 provided in the cylinder head and in the engine block provided lubrication points 8 promotes. One of each of these lubrication points leads Return line 9 or 10 back to the lubricating oil reservoir 2.

The oil pump is the one usually used in internal combustion engines existing oil feed pump, which is driven directly by the internal combustion engine, like that by the dashed connection 11 to the crankshaft 12 in the drawing indicated -is. Such an oil pump is usually only used during operation operated by the internal combustion engine. In the example running, however, there is an independent one Operation possible, for which purpose a switchable clutch 14 is provided in connection 11 is. On the other hand, there is an electric drive motor 15 on the pump 4 coupled.

Instead of the switchable clutch that controls the oil pump for the duration of the Drive by the drive motor 15 separates, but a freewheel can also be used will.

The latent heat accumulator 6 is a memory with known principle of action. Such latent heat stores are used as storage means a saline solution that changes from a crystalline form when heat is applied to the liquid state passes. However, this liquid state of aggregation can are retained when cooling, so that the filling of the latent heat storage also remains liquid in the severely supercooled state. With a starting device, in crystallize the filling of the latent heat storage from this supercooled state, the latent heat of crystallization is released and available as thermal energy stands. The starting of the latent heat accumulator can, for. B.

done by seeding with a salt crystal.

The latent heat storage 6 is designed as a heat exchanger of the type how-he z. B. in Fig. 11 or 13 is shown.

The oil delivered by the oil pump 4 flows on the heat exchange surface of the latent heat accumulator and leaves it after the latent heat is released when heated.

However, the opposite can also happen to the latent heat accumulator 6 When the internal combustion engine is warm, oil gives off heat to the latent heat accumulator and these heat up so that its filling z. B. from the crystalline state back into the liquid state passes.

The facility works as follows: Assuming that the Latent heat storage 6 was already heated once, so its content is in the liquid State, it is able to do so even before the internal combustion engine is started To give off heat to them. This takes place via the oil circuit of the internal combustion engine. The oil pump 4 is operated by the drive motor 15, preferably before the start taken and cold oil from the lubricating oil reservoir into the latent heat storage pumped. The oil pump is controlled by the switchable clutch or the freewheel 14 uncoupled from the internal combustion engine. Simultaneously with the commissioning of the Oil pump, the latent heat storage 6 is started so that the flowing through it Oil is heated.

This now gets into the blkreislauf of the internal combustion engine z. B. to the lubrication points in the cylinder head and to the lubrication points in the engine block. It does not have to include the entire lubrication system of the internal combustion engine with the heated one Lubricating oil are supplied. The parts of the internal combustion engine are advantageous the temperature of which particularly affects the starting and warm-up behavior of the internal combustion engine impact, selected.

For this purpose, a pressure line can be connected directly from the latent heat accumulator these selected parts of the lubrication system.

The remaining parts of the lubrication system that do not need to be heated bl are to be supplied, can be disconnected by means of a backflow preventer will.

Preheating the lubricating oil reduces its viscosity, the breakaway torque decreases and the engine speed is increased so that the start can take place. This allows the necessary power consumption of the starter to be reduced and it Smaller starters and batteries can be used in the internal combustion engine. The warming up and circulation of the lubricating oil before the start prevents in particular also the re-increase of the breakaway torque, which occurs after the start of the engine Oil pressure is caused. The starting speed is maintained and the initiated Start remains safe. The previously circulated oil is advantageous At the start, an oil cushion was removed from the lubrication points, so that also the wear the internal combustion engine is reduced.

The latent heat accumulator 6 can also be an easily replaceable part be arranged outside the internal combustion engine and preheated externally if necessary will.

As the drive motor 15 of the oil pump, z. B. the alternator the internal combustion engine can be used. This is on the drive side of the alternator, So in their connection to the internal combustion engine, a switchable clutch or a Freewheel provided so that the alternator when the engine is running from the internal combustion engine is uncoupled.

It is also possible, for. B. to use the starter as a drive motor, an apparatus is provided in which the engagement control of the starter pinion in the drive gear of the internal combustion engine is disabled for so long Before starting the internal combustion engine, the oil pump 4 is to be put into operation.

The embodiment according to Fig. 2 shows a variant of an oil circuit, which is used to preheat other parts of the internal combustion engine. Here too is the internal combustion engine 1 shown schematically with a lubricating oil reservoir 2, from which an oil pump 4 oil via a check valve 5 through a latent heat accumulator 6 promotes. From this one leads first pressure line 16 to selected Parts of the lubrication system as shown in FIG. However, it is possible that to use heated oil to heat other parts of the internal combustion engine. For this purpose, a second pressure line 17 branches off from the first pressure line 16 from, which leads to a heat exchanger 18, which is used to heat selected parts of the Suction system and the fuel supply z. B. is used in the carburetor. The exit of the heat exchanger can now either be connected directly to the lubricating oil reservoir 2 or are in communication with a spray device 19. The spray device 19 is arranged within the cylinder head cover 20 and designed so that the valve train and the area of the cylinder head having the intake ports is sprayed. The leaked oil then flows through another part of the internal combustion engine provided return line 21 back to the lubricating oil reservoir. For controlling of the oil circuit are a first valve 23 and in the first pressure line second pressure line, a second valve 24 is arranged. the alternatively opened or both can be open. The supply of the heat exchanger 18 or the Spray device 19 takes place independently of the lubrication system of the internal combustion engine and can be switched on or off at will. A connection is z. Belly makes sense if the oil temperature rises at full load. wherein the heat exchanger 18 can serve as an oil cooler. The spray device can also, as shown in Fig. 3, can be switched on or off by a valve.

In Fig. 2 a second solution is also drawn (dashed), in which an additional oil pump 26 is provided in addition to the oil pump 4. This promotes from the lubricating oil reservoir also via a check valve 27 to the oil Latent heat storage, which in this case as latent heat storage 6 'has two separate Has heat exchange systems. The first system is supplied by the oil pump 4 and leads to the first pressure line 16, while the second system with a second pressure line 17t is connected to the originally intended pressure line 17 replaced. Otherwise, the design is constructed as described above. the Additional oil pump 26 is driven by a drive motor 28, while the oil pump 4 is driven directly by the internal combustion engine. The drive of the additional oil pump 26 can take place in the same way as when driving the oil pump 4 has been described in more detail in the embodiment of FIG. With the alternative As an embodiment of FIG. 2, it is now possible to use the additional oil pump and the latent heat accumulator 6 'to be put into operation before the internal combustion engine is started. It stands an oil circuit that is completely separate from the rest of the lubrication system is available Contains heat exchanger 18 and the latent heat storage 6 '. Optionally, the Spray device 19 can be switched into this oil circuit. After starting the Internal combustion engine is also selected via the first pressure line 16 Part or the remaining part of the lubrication system of the internal combustion engine with the im Latent heat storage 6 'heated oil is supplied. The reheating of the latent heat storage 6 'takes place essentially through the oil circuit contained in the oil pump 4, since the oil circuit contained the additional oil pump 26 only in special cases z. B. at Oil temperature too high when the internal combustion engine is in operation is taken.

This design comes because of the low back pressure with a relatively small drive power for the additional oil pump. Still, the for the preservation of the essential parts of the operating mixture once it has been generated heated so that there is no undesired excretion of fuel on cold Intake manifold or carburetor walls. By the additional oil pump 26 contained The oil cycle can be achieved in an advantageous manner even at low starting temperatures with a relatively low enrichment of the starting fuel / air mixture from what is particularly beneficial in terms of pollutant emissions and fuel consumption affects.

In the embodiment of FIG. 3 is also the Fuel machine 1 with cylinder head cover 20 and lubricating oil reservoir 2 shown schematically. The oil pump 4 removes the lubricating oil container 2 directly from the internal combustion engine is driven, lubricating oil and conveys this via a first delivery line 30, which contains a check valve 5, to the latent heat storage 6. In parallel an additional oil pump 26 is provided, which, as in the embodiment according to Fig. 2 is driven by the drive motor 28 or other possible variants. The additional oil pump 26 conveys via a second delivery line 31, which the cross-flow valve 27 also contains oil to the latent heat accumulator 6, where the first delivery line is and unite the second delivery line.

As in the exemplary embodiment, the latent heat accumulator 6 shows Fig. 1 only a single heat exchange system for the blkreislauf. From the latent heat storage 6 now leads a pressure line 33 to a heat exchanger also provided here 18, which surrounds the intake manifold 34 of the internal combustion engine. From the heat exchanger 18 leads the pressure line 33 further to selected lubrication points 35 of the lubrication system and from there via a return line 9 to the lubricating oil reservoir 2. It can furthermore via a connecting line 37 which contains a valve 38 and a throttle 39, the spray point 19 is supplied with heated oil as in the exemplary embodiment according to FIG. 1 will. The oil escaping there is returned via the return line 21.

In this device, the additional oil pump 26 is in Put into operation and at the same time the latent heat storage 6 started. After this Starting the internal combustion engine, the oil pump takes over the oil pump 4, so that the Additional oil pump can be switched off. The oil heated in the latent heat store 6 is successively the intake manifold and selected lubrication points of the internal combustion engine fed. Of course, it is also possible here to use the lubrication points and the suction pipe to be supplied with lubricating oil in parallel to each other. Optionally, the valve 38 the spray device can be switched on or off. When the internal combustion engine is at operating temperature the previously discharged latent heat accumulator 6 becomes due to the increasing temperature again charged, so that there for a later start after the engine has cooled down the necessary heat energy is available again. The spray device can except for the preheating operation, they can also be switched on during full load operation in order to Cooling of the oil leads to an increased oil throughput in the heat exchanger 18 and in the oil cooler achieve.

While in the above embodiments, the warming up of the Internal combustion engine using oil as a heat transfer medium is carried out in the following Embodiments of the cooling water present in the internal combustion engine as a heat transfer medium used. Again in a simplified configuration, FIG. 4 shows the engine block 41 and the cylinder head 42 of an internal combustion engine.

Both parts are in an internal combustion engine designed in the usual way one behind the other in a cooling system, which continues to have a radiator 44 as a three-way valve designed thermostatic valve 45 and a cooling water pump 46 contains.

A feed line 48 of the cooling system leads from the cooling water pump 46 to the engine block 41. This is via a connecting line 49 with the cooling chambers of the cylinder head 42 connected, from where a return 50 to the radiator 44 and from there leads back to the cooling water pump 46 via the thermostatic valve 45. Upstream of the cooler 44 branches off a bypass line 52 and leads to the third connection of the Thermostatic valve 45. Depending on the position of the thermostatic valve closing element is now in a known manner the cooling water flowing back via the return 50 or more less, depending on the heating level directly via the thermostatic valve on the suction side fed to the cooling water pump. The cooling system is thus divided into an inner and a divided outer cooling circuit. This way of working.

is well known and does not need to be explained in more detail here.

According to the invention, a latent heat exchanger is now in the bypass line 52 54 arranged. Furthermore, there is a changeover valve in the feed line 48 55, which in its one position releases the flow in the supply line 48 and in its other position those located upstream of the switching valve part the feed line 48 with a second feed line leading directly to the cylinder head 42 56 connects. The switching valve is an electromagnetically actuated one Switching valve, the magnet winding 58 of which is controlled by a control device 59 which is connected to a temperature sensor 60 in the engine block.

The cooling water pump is when parts of the with the help of the cooling system Internal combustion engine should be preheated before starting, by a special provided drive motor in the same way as in the embodiments described above driven. The mode of operation in this case is shown in FIG. 6 Graphic clarified. As long as the internal combustion engine is cold, the cooler 44 switched off by the thermostatic valve 45, so that the return of the cooling water takes place via the return 50 and the bypass line 52 to the cooling water pump 46. Consequently is also the latent heat storage 44 when the cooling water pump of the entire amount of cooling water pumped flows through. At time TO, the Cooling water pump 46 put into operation, the latent heat storage 54 started and the switching valve 55 switched so that the connection between the flow line 48 and second flow line 56 is made. When starting, the latent heat storage is released 54 its heat from the cooling water, which this to selected parts of the cooling system, in this case the cylinder head 42 leads. The cooling water cooled there is during of the return is warmed up again in the latent heat accumulator. The curve 63 in Fig. 6 gives the duration of the heat release of the latent heat store 54 from the point in time TO to the point in time T3 on. From this point on, the cooling water is in due to the combustion processes the internal combustion engine warmed up to such an extent that the latent heat accumulator is recharged will. The curve 64 shows the duration of the connection between the flow line 48 and second flow line 56 from T0 to T2, while curve 65 shows the duration of the through connection represents the flow line 48 to the engine block. The curve 66 gives beginning to Time T1, in which the internal combustion engine is started, the increase in temperature in engine block 41. From a certain temperature tl, which is determined by the temperature sensor 60 is detected, as can be seen, the switching valve 45 is switched. From the time Until time T1, the cooling water pump is driven by an electric motor. During this time, the cylinder head 42 is preheated, so that at time T1 the desired conditions for the start of the internal combustion engine that took place at this point in time given are. Instead of the cylinder head or in addition, as shown in dashed lines is shown in Fig. 4, the second flow line 56 via a heat exchanger flow 70 are connected to a heat exchanger 67, the selected parts of the suction system 68 or surrounds the fuel-carrying part of the internal combustion engine. The suction system is in the usual, known connection with the internal combustion engine. From the heat exchanger 67, a heat exchanger return 69 leads back to the return 50.

For optional switching of the cooling water circulation from the cylinder head 42 on the heat exchanger 67 is downstream of the junction of the heat exchanger flow 70 a valve 72 is provided, in its closed position only the heat exchanger 67 is supplied with heated cooling water. With a valve 71 in the flow 70 the heat exchanger 67 is switched on or off. In addition, various Options for connecting or disconnecting parts of the cooling system of the Imagine internal combustion engine, which will not be explained in more detail here needs. It is a matter of optimizing which parts of the internal combustion engine and to what extent are heated to maintain optimal starting conditions have to.

7 shows a modified control option for the switchover valve 55 in the exemplary embodiment according to FIG. 4. In this case, the temperature sensor is used 60 maintained in the engine block and a second temperature sensor 73 in the second flow line 56 used. The values of both temperature sensors are shown in a comparison circuit 74 compared with each other.

The comparison circuit 74 gives the temperature in the engine block as soon as possible is higher than in the second flow line 56, a switching signal from the switching valve 55 in one position brings, in which the flow line 48 to the engine block is switched through. The mode of operation for the control according to FIG. 7 is based the graph according to FIG. 8. The curve is again designated there by 63, which indicates the duration of the heat release of the latent heat storage unit 54. The curve 76 gives the temperature of the cooling water flowing in the second flow line 56, which increases with the duration of the discharge of the latent heat storage. The curve 77 indicates the course of the temperature in the engine block 41. This temperature begins at the point in time T1, in which the internal combustion engine is started, to rise and reached at the point in time T3 has a value that is higher than the temperature of the cooling water in the second flow line 56. At this point in time, the second flow line 56 is switched off, and that The cooling water delivered by the cooling water pump 46 now flows completely through the Engine block 46, via the connecting line 49 into the cylinder head 42 and from there back via the return 50. At this point in time or

shortly thereafter, the heating of the latent heat store 54 also begins.

The embodiment according to FIG. 5 has a modification of the exemplary embodiment 4, in addition to the cooling water pump 46, there is an additional cooling water pump 79. the Cooling water pump 46 is rigidly driven here by the internal combustion engine and has a supply line * 8 'which is directly connected to the engine block 41. A connecting line 49 ′ leads from the engine block 41 via a 4/2-way valve 80 to the cooling water inlet on the cylinder head 42. The cooling water inlet on the cylinder head 42 is also via a second flow line 56 'with the connecting line 82 between Thermostatic valve 45 and cooling water pump 46 connected. In this supply line is the additional cooling water pump 79 is arranged and downstream of it one in the direction of the cylinder head Opening check valve 83. Between the branch of the second flow line 56 t of the connecting line 82 and the cooling water pump 46 lies in the connecting line 82 also the 4/2-way valve 80. This is with the help of an electric magnet 84 actuated, which is activated by control devices 59. The control device is connected to the temperature sensor 60 as in FIG. 4.

The 4/2-way valve is designed so that in its one position the connection of the connecting line 82 to the cooling water pump 46 is established and at the same time the connection of the connecting line 49 'to the cylinder head 46.

In its second switch position, the connecting line 49 'is with the cooling water pump 46, while the connection to the cylinder head 42 and the connection line 82 is interrupted. In this position an internal Cooling water circuit made for the engine block 41, which is completely different from the rest Cooling water circuit, the latent heat storage 54 and the cylinder head to be heated 42 contains, is separated. The circulation of the cooling water in the rest of the cooling water circuit takes place via the additional cooling water pump 79. In the other position of the 4/2-way valve engine block 41 and cylinder head 42 are connected in series. The cooling water pump 46 serves as the main circulation pump.

In Fig. 9 is the functional diagram of the device described above reproduced. The curve 63 in turn shows the discharge-charge process of the latent heat storage device marked, with the curve 77 the temperature profile in the engine block at the point of the temperature sensor 60 and, with the curve 86, the switch-on duration of the additional cooling water pump 79 from TO to T3. The curve 87 shows the operating time of the cooling water pump 46, which is identical to the running of the internal combustion engine. Takes place at time T1 thus after a preheating time from TO to T1 the start of the internal combustion engine, whose temperature according to curve 77 increases continuously. When the temperature t1 is reached, the 4/2-way valve switched over, so that the cooling water, which now warms up more strongly The latent heat accumulator 54 is supplied via the cylinder head and the charging process there the latent heat storage begins.

Instead of the described control of the 4/2-way valve 80 can also the control described in more detail in FIG. 4 can be applied. This control points an adaptation to the capacity of the latent heat accumulator 54, which is therefore never longer is used as a heat source as necessary.

With the help of the additional cooling water pump 79 can be in a simple manner carry out the heating of the parts of the internal combustion engine before starting. After reaching the operating temperature this pump is switched off. In the meantime between The circulation pump starts and reaches the desired operating temperature (t1 to t3) 46 for the necessary temperature distribution within the internal cooling water circuit of the engine block.

Instead of the cylinder head, the one described in more detail in FIG. 4 can also be used Heat exchanger 67 are heated. The heat exchanger flow 70 is via the Valve 71 connected to the second flow line 56 ', while the heat exchanger return 69 opens into the return 50. If the heat exchanger 67 is only to be operated alone are, it is also here in the second flow line 56 'downstream of the Branch of the heat exchanger flow 70 provided valve 72 to close.

A heat exchanger 88 is in the same way as the heat exchanger 67 connectable, which is arranged in the lubricating oil reservoir of the internal combustion engine and is used to heat the lubricating oil.

In the embodiment according to FIG. 10, a part of the suction pipe 90 of an internal combustion engine 91 reproduced.

Part of an exhaust pipe 92 of the internal combustion engine is also shown. The intake manifold initially has a carburetor 93 through which, in terms of composition and amount of a fuel-air mixture is metered, which via the intake manifold 90 of the Internal combustion engine is supplied. As is known, it occurs when the internal combustion engine is cold in the intake manifold 90 to a condensation of the fuel from the fuel-air mixture on the cold suction pipe walls. These walls were used in the examples described above heated by the heat exchanger 18 and 67, respectively. In the embodiment according to FIG. 10 is in a critical area of the intake manifold where condensation of the Fuel would occur more intensely, a heatable wall part 94 is provided. This Wall part is made very thin and is characterized by high thermal conductivity the end.

On the outside of this wall part 94 is via an exhaust gas bypass line 95 warm exhaust gas bypassed.

The exhaust gas bypass line 95 is implemented in the area of the wall 94 Example, as can be seen from the section according to FIG. 11, divided into two tubes with semicircular cross-section. The flat surface of the pipes is created by the wall part 94 formed, while the remaining wall parts of the tubes to a latent heat storage 97 adjoin that with the remaining parts of the wall part 94 in thermally conductive Contact is available. The latent heat accumulator 97 is of the same type as that described above Examples. In order to reheat the latent heat accumulator, it has heat exchanger tubes 98 on by a branch line 99 which is immediately downstream of the junction the exhaust gas bypass line leads away from the exhaust gas line 62, is supplied with heated exhaust gas will.

The heat exchanger tubes 98 open downstream of the wall part 94 in the exhaust gas bypass line 95, via which the exhaust gas flowing through the latent heat accumulator is returned to the exhaust pipe 92. The inlet opening of the exhaust branch line 99 can be closed by a flap 100 which, in relation to the exhaust branch line 99 open position reduces the cross section of the exhaust pipe 92, so that the Exhaust gas flowing here is directed through the latent heat accumulator 97. In parallel the exhaust gas is also led past the wall part 94 through the bypass line 95.

In Fig. 11 a section through the latent heat storage is shown, from which it can also be seen that the latent heat storage device 97 is covered by a heat insulating layer 101 is protected against cooling to the outside. This is especially important when the latent heat storage has been ignited and gives off heat. Through the thermal insulation layer it is achieved that the heat given off by the latent heat storage is essentially the wall part 94 is supplied. The control of the flap 100 takes place via a control device 103, which are arranged with one upstream of the flap in the exhaust pipe 92 Temperature sensor 104 is connected. There is also a second temperature sensor 105 arranged in the latent heat accumulator, which is also connected to the control device 103 is.

An adjusting device, not shown, for the bypass flap is controlled by the control device 103 so that when a certain Value of the exhaust gas temperature, the flap 100 is opened and when a value is exceeded Limit temperature in the latent heat storage 97, the flap 100 is closed again. In this way, the latent heat storage is protected from overheating and in good time supplied with warm exhaust gas for recharging.

The latent heat accumulator is activated by a starting device (not shown further) preferably ignited before starting the internal combustion engine, so that the intake manifold 90 of the internal combustion engine is preheated. The flap 100 is at this point closed. After starting with the gradually warming exhaust gas, there will be a certain exhaust gas temperature, the flap 100 is opened, so that the latent heat storage be brought back to its maximum permissible temperature by the warm exhaust gas can. In this operating range, the wall part 94 is primarily through the exhaust gas bypass line 95 which are located in the area of the wall part to achieve a larger heat transfer surface branched, warmed.

For quick warming up of the latent heat storage, which in particular for short-distance operation of a motor vehicle operated with the internal combustion engine It is important that the heat exchange pipes are provided with catalytically active material.

In this way there are still unburnt components of the exhaust gas implemented directly in the latent heat storage and correspondingly additional heat energy released. Should the oxygen content in the exhaust gases for an implementation of the unburned Components of the exhaust gas are not sufficient, so can in an additional embodiment a secondary air valve 114 can be provided upstream of the flap 100 in the exhaust pipe 92 opens.

The valve is activated during the fuel enrichment phase Warm-up mode of the internal combustion engine is open.

FIG. 12 shows a modified form of the embodiment according to FIG. 11, has essentially the same structure and only has one different from it Additional catalyst 107, which is in the branch line 99 upstream of the latent heat accumulator 97 is arranged. With the help of this catalyst a better burning of the achieved unburned components of the exhaust gas, so that the loading time of the Memory is shortened significantly.

13 shows a section through an embodiment of the latent heat store and the exhaust gas bypass line in the area of the wall part 94. The wall part 94 is in this The case is provided with grooves 108 on the outside, which guide the exhaust gas in this area to serve. The grooves are on the other side by the latent heat storage 97 ' closed so that guide channels are made of the grooves. The latent heat storage is made up of several individual packages 109 in the example shown. These wise also on the opposite walls beads 111, the kind that two juxtaposed Packages with their corrugations form tubes that have the same function as the heat exchange tubes 98 in the exemplary embodiment according to FIG Fig. 10 and 11. The individual packages 109 are by tie rods 112 against each other and pressed onto the wall part 94 of the suction pipe 90. In addition, an isolation can be as set out in FIG. 11, can be provided. This design makes it easy possible, the available heat capacity of the memory the requirements of the part of the internal combustion engine to be heated.

A heating with the help of latent heat storage, whereby the heat storage gives off heat to parts to be heated by conduction, can also be transferred to others Apply positions of the internal combustion engine. The latter solution has the advantage that only a few moving parts are necessary to control the heat output. With With the help of a latent heat accumulator, heating can be achieved in a very economical manner Carry out selected parts of the internal combustion engine, so that the starting and warm-up behavior, as previously described, can be significantly improved. The warming affects in particular on the likelihood of starting, exhaust emissions, fuel consumption, and driving safety and reliability in the warm-up phase.

Device for heating parts of an internal combustion engine Summary A device is proposed for heating parts of an internal combustion engine with the help of heat stored when the internal combustion engine is at operating temperature. For storage serves a supercoolable latent heat storage, whose heat especially before Start the internal combustion engine to the heat transfer medium one of the selected heating Parts of the internal combustion engine circuit, triggered by a starting device, is deliverable. This makes it possible to fully recover the stored heat to provide longer breaks in operation of the internal combustion engine.

Claims (21)

Claims 9 EinrichQung for heating parts of an internal combustion engine with a heat accumulator from which heat, in particular for heating parts of the Internal combustion engine, is removable, characterized in that as a heat accumulator a supercoolable latent heat storage (6, 6 ', 54, 97) serves as a heat exchanger is designed for heat emission and heat absorption and a starting device for has the heat dissipation. 2. Device according to claim 1, characterized in that the latent heat storage contained in at least a part of the lubrication system of the internal combustion engine Ö1 circuit is switched and with oil as the heat transfer medium flowed through is, the bl taken from the lubricating oil reservoir (2) of the internal combustion engine (1) and by means of an oil pump (4, 26) to the downstream of the latent heat accumulator to be heated parts (7, 8, 18, 19) lying in the oil circuit are passed by to give off heat. 3. Device according to claim 2, characterized in that the oil pump (4, 26) can be driven independently of the internal combustion engine, and at least before the start of the internal combustion engine at the same time as the start of the latent heat accumulator can be switched on. 4. Device according to claim 2, characterized in that the downstream the latent heat storage part of the oil circuit selected parts of the lubrication system the internal combustion engine contains. 5. Device according to claim 4, characterized in that at least a valve (24) that can be switched depending on at least one operating parameter or pump for switching the oil circuit to selected heat transfer points is arranged. 6. Device according to one of the preceding claims 2 to 5, characterized characterized in that between the cylinder head of the Fuel machine and the cylinder head cover covering the gas exchange valve actuation device (20) an air spray device (19) is provided, which is located in the downstream of the latent heat accumulator lying oil circuit is arranged. 7. Device according to claim 1, characterized in that the latent heat storage (54) in a cooling water circuit contained in a part of the cooling system of the internal combustion engine is switched and is traversed by the cooling water as a heat transfer medium, wherein the cooling water is taken from the cooling system by means of a pump (46, 79) and sent to the to be heated downstream of the latent heat storage in the cooling water circuit Parts of the internal combustion engine is passed. 8. Device according to claim 7, characterized in that the pump (46) can be driven independently of the internal combustion engine and at least before Start of the internal combustion engine at the same time as the start of the latent heat accumulator is observable. 9. Device according to claim 7, characterized in that the downstream of the latent heat accumulator (54) located part of the cooling water circuit Contains parts (42) of the cooling system of the internal combustion engine. 10. Device according to claim 7, characterized in that the lubricant reservoir (2) a heat exchanger (88) is arranged, which is located in the downstream of the latent heat accumulator lying cooling water circuit lies. 11. Device according to claim 9, characterized in that the cooling water circuit partly from the inner cooling circuit (48, 41> 42, 50, 52) of the cooling system of Internal combustion engine exists. 12. Device according to claim 11, characterized in that downstream of the latent heat store (54) depending on the temperature at least a temperature measuring point switchable valve (55, 80) or cooling water pump (79) provided for switching the cooling water circuit to selected heat emission points is. 13. Device according to claim 1, characterized in that the latent heat storage (97) in thermally conductive contact with parts to be heated (94, 90) of the internal combustion engine lies. 14. Device according to claim 13, characterized in that the Latent heat storage in thermally conductive contact with parts of the suction system (94) downstream the fuel addition device (93). 15. Device according to claim 13 or 14, characterized in that that the latent heat storage is designed as a heat exchanger for reheating and can be connected to the exhaust system (92) of the internal combustion engine. 16. Device according to claim 15, characterized in that a Part of the space of the latent heat storage through which the exhaust gas flows through on the one hand the wall of the latent heat storage and on the other hand through the wall to be heated (94) is formed. 17. Device according to claim 15, characterized in that the Latent heat storage is located in an exhaust gas bypass line (95) to the exhaust gas line (92). 18. Device according to claim 17, characterized in that on the exhaust side in the latent heat storage or upstream of the latent heat storage catalytic material is arranged. 19. Device according to claim 17 or 18, characterized in that that in the exhaust line (92) downstream of the branch of the exhaust bypass line t95) a temperature-dependent controllable throttle element (100) is arranged. 20. Device according to claim 19, characterized in that the Throttle element (100) as a closing element for at least part of the connection opening the * bypass line (99) to the exhaust line is formed and depending on the temperature in the latent heat storage and the temperature of the exhaust gases in the exhaust pipe (92) is controllable. 21. Device according to claim 20, characterized in that the Closing member (100) via an actuating device controlled by a regulating device (103) when falling below a certain exhaust gas temperature and when exceeding a Fixed temperature of the latent heat storage is closable.