EP2318678B1 - Heat management module of the cooling system of an internal combustion engine - Google Patents

Abstract

The invention relates to a heat management module (6) of the cooling system of an internal combustion engine (1) comprising at least one first feed connection (8) arranged on a valve housing (7) for cooling water of a bypass circuit (3) and at least one adjacent second feed connection (9) for cooling water of a radiator circuit (2). Said feed connections can be connected to a discharge connection (11) depending on the position of a valve member accommodated in the valve housing (7), wherein driving means for actuating the valve member are provided on the valve housing (7) and are designed as a hydrostatic servo motor (12), which produces a rotating driving motion and which uses a feed pressure line (17) branching from the cooling system for pressurization.

Description

Field of the invention

The present invention relates to a thermal management module of the cooling system of an internal combustion engine, having at least one arranged in a valve housing first supply port for cooling water of a bypass circuit and at least one adjacent second supply port for cooling water of a radiator circuit, which are connectable depending on the position of a valve housing housed in the valve member with a discharge port, wherein on the valve housing drive means are provided for actuating the valve member. Furthermore, the invention also relates to a cooling system comprising such a thermal management module.

The cooling system of an internal combustion engine usually comprises two coolant circuits. A bypass circuit, or short circuit called, the internal combustion engine, the cooling water without cooling again. In the cooler circuit, the cooling water flows through a previously designated as a cooler heat exchanger before it is fed back into the internal combustion engine. Excess heat is dissipated in the heat exchanger and delivered to a secondary coolant. Both cooling circuits of the internal combustion engine can be switched on simultaneously or shifted in time. The targeted distribution of the cooling water flow to both circuits, the internal combustion engine is adjusted in the range of the optimal coolant temperature. As a result, compliance with the permissible limit temperatures for engine and transmission is ensured in the first place. In addition, the competing requirements with regard to consumption-optimized warm-up and rapid indoor climate control must be taken into account become. In modern cooling systems of the prior art, this is usually implemented by flexibly controllable components, such as an electric coolant pump, whose speed is not fixed to the rotational speed of the crankshaft, as well as an electrically controllable map thermostat, electric fan and heater valves. As a result, the design of the cooling system to the above boundary conditions including a flexible thermal management is possible. Intelligent heat management can also reduce fuel consumption and pollutant emissions. Particularly suitable for this purpose are an externally cooled exhaust gas recirculation as well as the shortening of the warm-up phase due to coolant standstill and a decoupling of thermal masses. By adapting the coolant temperature to the present load range of the internal combustion engine with the aid of a thermal management module, these goals can be achieved.

From the US 4,644,909 such a thermal management module emerges. The thermal management module comprises a valve mechanism, with which a cooler circuit and / or a bypass circuit of a cooling system can be switched. This is done by means of an electric motor, which is controlled by an electronic control, the input side evaluates the signal of a cooling water temperature sensor to actuate the valve mechanism depending on the prevailing cooling water temperature, so that the mixing ratio of the cooling water between the two cooling circuits is adjusted based on a predetermined cooling water temperature. The valve mechanism includes a valve spool that performs either a linear or rotational indexing movement. Accordingly, the electric motor drive is designed either as a linear drive, for example in the form of a proportional magnet, or as an electric stepper motor for generating the rotary switching movement.

From the DE 198 49 492 A1 shows another heat management module that has a valve member for switching a bypass circuit and a radiator circuit of a cooling system. The valve member is designed in this prior art as a rotary valve, which is driven by an electric motor. With the electric motor drive, the valve member can optionally in bring a blocking position for the radiator circuit and the bypass circuit or in an open position between the radiator circuit or the bypass circuit. In addition, it is also possible to produce a mixed operation by simultaneous connection of the cooler circuit and the bypass circuit with the discharge port to realize thermal management within the cooling system by a map-controlled cooling. By selecting a suitable switching position of the valve mechanism optimal coolant temperature is possible for each operating condition of the internal combustion engine, which leads to the aforementioned reduction in fuel consumption and pollutant emissions while sparing the internal combustion engine.

A disadvantage of the above-discussed prior art, however, affects the electromotive drive of the valve mechanism. For an electric motor drive in a thermal management module, which has a cooling water flowed through valve mechanism, must allow reliable reliable permanent separation of cooling water flowed through and electrical / mechanical component area. Otherwise, for example, undesirable coolant flowing over a seal leakage in the area of the electromotive drive means could cause an electrical short circuit or progressive wear there, which leads to the failure of the drive for the thermal management module. Furthermore, the requirements for electromechanical components in vehicle construction in view of the prevailing environmental conditions in the area of the cooling system can usually be realized only by expensive constructions, which are able to meet the specific higher temperatures, the required sealing properties, the desired power requirements and service life.

Thus, for example, it has already been attempted to accommodate the electromotive drive of a valve mechanism of a thermal management module in a separate housing and to be transmitted via a spur gear to the valve mechanism. Although the separate housing prevents leakage caused by leakage of cooling water in the electric motor drive, however, this requires spatial separation, the technical Expenditure of an additional gear stage for power transmission and a total of quite a large amount of space.

It is therefore the object of the present invention to provide a thermal management module of a cooling system for an internal combustion engine, which is of compact construction and robust design and at the same time can be operated without risk of leakage over the entire lifetime in the cooling system.

The object is achieved on the basis of a thermal management module according to the preamble of claim 1 in conjunction with its characterizing features. The following dependent claims give advantageous developments of the invention.

The invention includes the technical teaching that the drive means for actuating the valve member of a thermal management module are designed as a rotating drive motion generating hydrostatic servo motor which uses a branching from the cooling system feed pressure line for pressurizing.

The advantage of the solution according to the invention lies in the fact that compared to electromechanical drives, the high power density and robustness of hydraulic drives is harnessed and on the other hand a permanently pressure-tight torque transmission is ensured on the valve member, because the required drive torque is generated directly on the valve member. The solution according to the invention works free of external leakage and makes use of the hydraulic pressure energy available per se in the cooling system for actuating the valve member.

Preferably, the hydrostatic actuator according to the invention should be designed in the manner of an internal gear motor. For an internal gear motor forms a very compact hydrostatic actuator, which is able to provide the drive energy for the valve member, which is preferably designed as a rotary valve to advantageously directly one use rotary drive movement of the internal gear motor as a switching movement. Should it be necessary due to special constructive boundary conditions to increase the torque delivered by a hydrostatic servomotor for use as a switching movement, it is proposed to interpose between the hydrostatic actuator and preferably designed as a rotary valve member a reduction gear, which may be formed for example as a spur gear. This variant also makes it possible to replace existing electromotive drive units with hydrostatic actuators of the type according to the invention, in order to increase the robustness of such a thermal management module.

A particularly compact hydrostatic servo motor, which is designed as an internal gear motor, results in which an internally toothed ring gear of the internal gear motor forms the rotatively movable part of the hydrostatic servo motor and is integrally formed with the rotary valve of the valve member. In this case, this functionally integrated component can be manufactured, for example, as an injection molded part made of plastic or light metal.

In connection therewith, it is proposed that the rotationally movable internally toothed ring gear mesh with a sun gear arranged in a stationary and eccentric manner in order to implement the principle of a gear motor. In order to ensure the drive movement by pressurization, a curved-shaped filler piece arranged in contrast to be stationary and eccentric should be included in the rotatively movable internally toothed ring gear. The filler seals by its outer arc shape the pressure area relative to the internal teeth of the ring gear. About an inner arc shape of the filler sealing against the adjacent thereto sun gear is realized.

The pressurization of the preferably constructed in the above manner internal gear motor is carried out according to a further measure improving the invention in that the front side of the drive region, a first Pressure connection and a second pressure connection arranged adjacent thereto are arranged, which can be mutually coupled to the feed pressure line in order to move the valve member pressure controlled along the two mutually opposite switching directions can.

For such a reciprocal coupling of the two pressure ports with the feed pressure line is proposed to use an electromagnetic pilot valve in the context of a hydraulic pilot control, which is preferably designed as a monostable 4/3-way valve. Due to the three switching positions, the two oppositely directed switching movements and an additional blocking position can be implemented. In order to bring the monostable 4/3-way valve in a defined emergency position in case of failure of the electrical control, it is proposed to perform this spring reset. By using the electromagnetic pilot valve, the advantages of electrically controlled systems with respect to the integration into the functionality of electronic controllers are maintained in the inventive solution, so that an integratability of the thermal management module according to the invention is given in the control algorithm of the engine control unit of an internal combustion engine.

The feed pressure line according to the invention for actuating the hydrostatic servo motor described above preferably starts from the region of the outflow-side connection of a cooling water pump integrated in the cooling system. Because here is the cooling water pressure in the entire system still pressure drop-free and thus the largest, so that the design of the hydrostatic servo motor can be done based on the prevailing there maximum cooling water pressure. As a result, the hydrostatic actuator can be sized as small as possible, which benefits the compactness of the thermal management module.

Figur 1

eine schematische Darstellung eines Kühlsystems einer Verbrennungskraftmaschine mit integriertem Wärmemanagementmodul, und

Figur 2

eine schematisch perspektivische Darstellung des Wärmemanagementmoduls nach Figur 1.

Further, measures improving the invention will be described in more detail below together with the description of a preferred embodiment of the invention with reference to FIGS. It shows:

FIG. 1

a schematic representation of a cooling system of an internal combustion engine with integrated thermal management module, and

FIG. 2

a schematic perspective view of the thermal management module according to FIG. 1 ,

According to FIG. 1 the cooling system of an internal combustion engine 1 essentially consists of a radiator circuit 2 and a bypass circuit 3. The radiator circuit 2 performs the heated by the internal combustion engine 1 cooling water by acting as a heat exchanger cooler 4, so that after cooling via a downstream coolant pump 5, the cooling water back in the Internal combustion engine 1 is available for its cooling. While this cooler circuit 2 is used for cooling the internal combustion engine 1, the bypass circuit 3 is used for heating the internal combustion engine 1, in particular during the warm-up phase, to heat the cooling water as quickly as possible near the optimum temperature, bypassing the radiator 4. The required for temperature control of the internal combustion engine 1 selection between radiator circuit 2 and bypass circuit 3 or a mixed operation between the two circuits is performed by a thermal management module. 6

According to FIG. 2 comprises the thermal management module 6 a - here only in schematic section shown - valve housing 7, to which a first supply port 8 for the cooling water of - not shown here - bypass circuit 3 and at least one adjacent second supply port 9 for the cooling water - which also not shown here - Radiator circuit 2 is arranged. Depending on the position of the here designed in the manner of a rotary valve 10, disposed within the valve housing 7 valve member, the two supply ports 8 and 9 are selectively connected to a likewise arranged on the valve housing 7 discharge port 11.

To actuate the rotary valve 10, a hydrostatic servo motor 12 is provided as the drive means, which, generating a rotating drive movement, directly actuates the rotary valve 10. The hydrostatic servo motor 12 is designed in the manner of an internal gear motor and has an internally toothed ring gear 13, which is formed rotatably movable in one piece with the rotary valve 10. The internally toothed ring gear 13 meshes with a counter-eccentrically arranged sun gear 14 to form a gear motor. In the ring gear 13, a contrast is fixed and eccentrically arranged arcuate filler 15 is also placed. The filler 15 forms together with the opposite and not coming to rest sun gear 14, two opposing gear motor internal pressure chambers, which are associated with a first pressure port 16a and a second pressure port 16b arranged adjacent thereto.

Both pressure ports 16a and 16b are mutually coupled to a feed pressure line 17, which branches off the feed pressure directly from the cooling system of the internal combustion engine. For mutual coupling of the two pressure ports 16a and 16b of the hydrostatic servo motor 12 to the feed pressure line 17, a monostable 4/3-way valve 18 is provided, which acts here as an electropneumatic pilot valve. The 4/3-way valve 18 is electrically controlled by an electronic heat management control 19, which is part of the engine control here.

The invention is not limited to the embodiment described above, but also includes modifications thereof, which are included within the scope of the following claims. Thus, instead of the embodiment of the valve member as a rotary valve and a turntable or the like can be used to form the valve mechanism of the thermal management module 6. In addition, it is also possible to choose as a valve member a translationally adjustable valve spool or the like. In this case, however, the rotating drive movement of the hydrostatic servo motor in a translational drive movement required for such a valve member to convert transmission technology. As well It is conceivable to couple the hydrostatic actuator motor generating the drive movement via an intermediate gear with the valve member to actuate this, for example, a spur gear, a worm gear or the like would be suitable, preferably a reduction gear for converting a fast speed of the hydrostatic servo motor to create a lower speed for generating the switching movement of the valve member.

LIST OF REFERENCE NUMBERS

1

Internal combustion engine

2

cooler Closed

3

bypass circuit

4

cooler

5

Cooling water pump

6

Thermal management module

7

valve housing

8th

first feed connection

9

second feed connection

10

rotary vane

11

exhaust port

12

hydrostatic servo motor

13

ring gear

14

sun

15

filling

16

pressure connection

17

Feed pressure line

18

4/3-way valve

19

Thermal management control

Claims (12)

1. Heat management module (6) of the cooling system of an internal combustion engine (1), having at least one first feed connection (8) arranged in a valve housing (7) for coolant of a bypass circuit (3) and at least one adjacent second feed connection (9) for coolant of a radiator circuit (2), the connections, depending on the position of a valve member accommodated in the valve housing (7), being connectable to a discharge connection (11), driving means for actuating the valve member being provided on the valve housing (7), characterized in that the driving means are embodied as a hydrostatic servo motor (12), which produces a rotational driving motion and which for pressurization uses a feed pressure line (17) branching off from the cooling system.
2. Heat management module (6) as claimed in Claim 1, characterized in that the hydrostatic servo motor (12) is embodied as an internal gear motor.
3. Heat management module (6) as claimed in Claim 1, characterized in that the valve member is embodied as a rotary spool (10), which is rotatably actuated by the drive means, either directly or by way of a reduction gear, according to a heat management module (19).
4. Heat management module (6) as claimed in Claim 3, characterized in that an internally toothed internal gear (13) constitutes a rotationally moving part of the hydrostatic servo motor (12) and is integrally formed with the rotary spool (10).
5. Heat management module (6) as claimed in Claim 4, characterized in that the rotationally moving internally toothed internal gear (13) meshes with a sun gear (14), arranged eccentrically in relation to the former, in order to form a gear motor.
6. Heat management module (6) as claimed in Claim 4, characterized in that the rotationally moving internally toothed internal gear (13) includes a curved filler piece (15) fixed and arranged eccentrically in relation to the former.
7. Heat management module (6) as claimed in Claim 2, characterized in that a first pressure connection (16a) is provided on the end face of the hydrostatic servo motor (12) and a second pressure connection (16b) is arranged adjacently thereto, said connections being capable of two-way coupling to the feed pressure line (17).
8. Heat management module (6) as claimed in Claim 7, characterized in that a monostable 4/3-way directional control valve (18) functioning as solenoid pilot valve is provided for the two-way coupling of the two pressure connections (16a, 16b) to the feed pressure line (17).
9. Heat management module (6) as claimed in Claim 8, characterized in that the monostable 4/3-way directional control valve (18) is spring-returned to a defined emergency position.
10. Heat management module (6) as claimed in one of the preceding claims, characterized in that at least the valve housing (7), the internal rotary spool (10) with internally toothed internal gear (13) formed on and the sun gear (14) corresponding to this are made of plastic or light metal casting.
11. Cooling system of an internal combustion engine (1) with a heat management module (6) according to one of the preceding claims, having at least one radiator circuit (2) and bypass circuit (3), which are operated by coolant pump (5) and can be controlled according to the heat management module (6).
12. Cooling system as claimed in Claim 11, characterized in that the feed pressure line (17) for actuating the hydrostatic servo motor (12) emerges from the area of the discharge-side connection of the coolant pump (5) integrated in the cooling system.

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