DE102009025341A1 - Control valve for regulating coolant circuit of internal combustion engine, has two feed connections arranged on valve housing for cooling water of bypass circuit and for cooling water of cooling circuit - Google Patents

Abstract

The control valve has two feed connections (2) arranged on a valve housing (1) for cooling water of a bypass circuit and for cooling water of a cooling circuit. A dynamic resilient sealing element (4) is provided for sealing the coolant flow paths in the axial or radial direction in a bore (5) of the valve housing provided as a feed connection. The sealing element is brought in contact with a valve link (3).

Description

Field of the invention

The The invention relates to a control valve for controlling a coolant circuit an internal combustion engine with the features of the preamble of claim 1. Furthermore, the invention relates to a coolant circuit with such a control valve.

A Internal combustion engine usually has two coolant circuits on. This leads the bypass circuit, which also short circuit is called, the internal combustion engine, the cooling water closed again without cooling. Im also provided Radiator circuit flows through the cooling water previously a heat exchanger called a cooler, before it is fed back to the internal combustion engine becomes. In the heat exchanger is excess Heat dissipated and sent to a secondary Coolant delivered. Both cooling circuits of the internal combustion engine can be switched on simultaneously or shifted in time become. By the achieved distribution of the cooling water flow on both circuits is the internal combustion engine adjusted in the range of the optimum coolant temperature. This is primarily the compliance with the permissible Limit temperatures for engine and transmission ensured. In addition, the competing requirements in terms of consumption-optimized warm-up and rapid interior climate control Be taken into account.

at modern refrigeration systems of the prior art become these Requirements usually by using flexibly controllable Valves implemented. They allow an optimal design of the cooling system to all boundary conditions as well as a flexible heat management. You can continue Fuel consumption and noise emissions with an optimized design of the cooling system.

A coolant regulator of the type mentioned above discloses, for example, the US 4,644,909 , The regulator described herein comprises a valve mechanism with which a radiator 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 and thus a predetermined cooling water temperature is set , The valve mechanism comprises a valve spool which, depending on the embodiment, performs either a linear or a rotational switching movement. In particular, for the linear switching movement, a hollow cylindrical valve member is used whose closed lateral surfaces alternately close mutually offset coolant connections. The electromotive drive is designed for the linear switching movement 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.

Especially in an electromotive drive of the valve mechanism, at a coolant regulator, which is a cooling water flowed through Ventilme has a reliable continuous separation of cooling water flowed through and electrical / mechanical component areas guaranteed be. Otherwise could have a seal leakage Coolant in the range of electromotive drive means penetrate and there an electrical short circuit and / or progressive Cause wear, which then leads to failure of the drive can lead to the coolant regulator. A permanently as possible secure sealing of the coolant flow paths However, it should also be provided with control valves that are not electromotive operate. Because even here seal leaks can do so cause the functionality of the system is restricted.

It is therefore a general concern, a control valve, in particular a control valve for controlling a coolant circuit an internal combustion engine to be executed such that Seal leaks are largely prevented. Special leak susceptible are dynamically loaded sealing points that move in the area Components are. The object underlying the invention can thus be seen therein, a control valve for controlling a coolant circuit to provide an internal combustion engine, which is a safe Sealing the coolant flow paths allows while being compact and simple. The operation Such a control valve can be electromotive, hydraulic or done pneumatically.

to Solution of the task is a control valve with the features of claim 1 proposed. Preferred developments of the invention are specified in the subclaims. The task is further solved by a coolant circuit according to claim 14th

The proposed control valve comprises a first arranged on a valve housing supply port for cooling water of a bypass circuit and at least a second supply port for cooling water of a radiator circuit, which depending on the position of a valve housing under brought valve member are connectable to a discharge port. According to the invention, in order to seal the coolant flow paths in the axial and / or radial direction in a bore of the valve housing provided as a feed connection, a dynamically loadable sealing element which can be brought into contact with the valve element is provided which is sleeve-shaped and at least over an axially extending portion of its inner circumferential surface and / or. or outer peripheral surface has a conical shape, so that the free flow cross-section decreases toward the valve member and / or increases the radial distance of the sealing element to the bore of the valve housing to the valve member.

The inside peripheral side and / or outside circumference conically Subareas allow self-centering alignment the sealing element during operation of the control valve. Thus, one is permanently tight contact of the sealing element on the valve member and / or at the formed as a feed connection bore of the valve housing guaranteed. On the one hand becomes a conical Part of an inner peripheral surface of the hydraulic pressure of the control valve flowing through the cooling medium acted upon, so that this pressure causes a self-centering, On the other hand, by a conical portion of the Outer circumferential surface is a radial distance of the sealing element for drilling the valve housing causes an inclination allows for self-centering alignment of the sealing element. By a self-centering alignment of the sealing element can production and / or assembly tolerances are compensated usually to a radial offset or misalignment of the sealing element with respect to the valve member lead.

Prefers Therefore, the sealing element of an inventive Control valve both at least over a subarea extending, tapered inner circumferential surface, as also an at least over a partial area extending, conical outer peripheral surface on.

Farther preferred is the axially extending, conically extending portion the inner peripheral surface at a valve member facing End portion of the sealing element arranged. The inner contour of the Dichtelementes thus has a nozzle shape, since the free Flow cross-section decreases towards the valve member. The on the conically extending inner peripheral surface adjacent hydraulic pressure and momentum forces make a sealing Installation of the sealing element on the valve member safe.

In contrast, is the axially extending, conically extending portion the outer peripheral surface preferably spaced arranged to at least one end portion of the sealing element. Thus, a middle part of the sealing element is preferably on the outer peripheral side formed tapered.

Farther it is provided that the sealing element has an axially acting sealing surface having, on a valve member facing the end face the sealing element is formed and preferably the outer contour the valve member is adapted, at this end face is applied. Advantageous with regard to a self-centering alignment of the sealing element affects a part-spherical outer contour the valve member and a thereto adapted face off at the sealing element.

By the sleeve shape of the sealing element is the axially acting Sealing surface on a linear contact area limited. The reduction of the sealing surface a linear contact area causes a Movement of the valve member with respect to the sealing element as possible low friction. In addition, over the contact pressure and the dynamic load is a slight plastic Deformation of the sealing element in the region of the sealing surface be effected, which contributes to a secure seal remains guaranteed.

Preferably is the longitudinal axis of the sealing element perpendicular to the longitudinal axis aligned the valve member. Indicates the valve member instead of a round one Cross-sectional shape of a polygonal cross-sectional shape, this is Sealing element preferably with a flat, annular Sealing surface on a straight side edge of the valve member at. Preferably, the frontal sealing surface of the sealing element not only adapted to the outer contour of the valve member, but also has a comparable surface quality on.

advantageously, takes place via the sealing element and a seal of the Coolant flow paths in the radial direction. For this purpose, according to a preferred embodiment, the Sealing element on a radially acting sealing surface. to Formation of the radially acting sealing surface has the sealing element at least in a partial area opposite to a radial excess the bore of the valve housing, so that the sealing element over this sub-area is biased against the housing. Since the outer contour conical at least over a portion runs, wherein preferably the radial distance of the sealing element for drilling the valve housing in the direction of the valve member increases, the radially acting sealing surface is preferred on an end portion of the sealing element facing away from the valve member educated. The radially acting sealing surface is also furthermore preferably shaped as a sealing lip.

The provided as a radially acting sealing surface sealing lip is according to a preferred embodiment forming a one-sided open annular gap in a radial Distance from the sealing element arranged. Through the annular gap is a the valve member facing away from the end face of the sealing element radially limited. This means that the annular gap to the Face opens. The annular gap ensures a sufficient freedom of movement of the sealing lip, for example to the insertion of the sealing element in the bore of the valve housing to facilitate. In the operation of the control valve also passes coolant, which flows through the control valve, in the annular gap, the therefore fills with coolant, so over the hydraulic pressure of the coolant a compressive force is exerted on the sealing lip, which presses against the housing. The required for the installation of the sealing lip on the housing Contact pressure is thus system pressure dependent - over causes the hydraulic pressure of the coolant.

to radial preload of the sealing lip opposite the bore the valve housing can also additionally an expansion element be arranged in the annular gap. As a spreading, for example find a sealing ring, in particular an O-ring use. By the expansion element experiences the sealing element a radial Expansion by the expansion element, the sealing lip of the sealing element pushes away against the housing. In this way can a pre-determined contact pressure independent of respective system pressure can be guaranteed.

to Ensuring a likewise system pressure independent sealing engagement of the sealing element on the valve member, the sealing element according to a further preferred embodiment acted upon by the pressure force of a spring element. Preferably the spring element is a wave spring or another as a compression spring trained spring element. The spring element can, for example on the end face of the sealing element facing away from the valve member be supported. The spring element provides an axial contact pressure sure that holds the sealing element in contact with the valve member.

While one end of the spring element supported on the sealing element is, the other end of the spring element is the housing side supported. For this purpose is preferably in the bore of the valve housing an axial stop, for example in the form of a radially inward extending paragraph or by inserting a stop ring, educated. About the pressure force of the spring element can the contact pressure to be determined, the sealing element in plant holds with the valve member.

There the sealing element, in particular in the region of its on the valve member adjacent sealing surface, exposed to dynamic loads is further preferably provided that it is wholly or partly from a thermoplastic, preferably from polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE). As a special suitable proves to be due to its very low coefficient of friction especially polytetrafluoroethylene as a material. PTFE also has the Advantage on that it has a high resistance to used as a coolant water-glycol mixtures and compared Particles containing as impurities in this mixture are and on sealing surfaces exert an abrasive effect can. Because a sealing surface made of PTFE allows a burying of such particles dig into the surface of the sealing element and thus their abrasive largely lose effect. As a result, the wear on the dynamically loaded sealing points are significantly reduced. Alternatively, a coating of PTFE in the dynamic range loaded sealing surfaces are provided.

The proposed control valve with a sealing element made of PTFE proves thus low maintenance and is characterized by a long life out. The low coefficient of friction of polytetrafluoroethylene simplified In addition, the assembly of the control valve, since the sealing element also at sealing system on the valve body easily into the housing can be used.

Especially simple and inexpensive, the proposed Sealing element for an inventive Produce control valve in a spray or injection molding. In this case, preferably, the sealing lip - provided so far molded directly onto the sealing element. To the manufacturing process continue to simplify, is the outer and / or inner contour the sealing element preferably designed such that the injection molding tool during demolding by a linear and / or rotational movement is easily removable. This means that the foreign and / or inner contour of the sealing element no undercuts may have.

The aforementioned advantages of an inventive Regulating valves show up regardless of which switching movement the valve member for controlling the coolant flows takes place. The valve member of an inventive Regulating valve can therefore be a linearly movable spool or be a rotatably movable rotary valve, wherein the valve member also a combined, d. H. a linear-rotary switching movement can perform.

Also claimed is a coolant circuit of an internal combustion engine with an inventive Re described above gelventil. To actuate the control valve used in the coolant circuit electromotive, hydraulic or pneumatic actuating means may be provided.

A preferred embodiment of the invention will be below described in more detail with reference to the drawings. Show it:

1 3 is a cutaway perspective view of a section of a control valve according to the invention in the region of a feed connection,

2 a truncated perspective view of the sealing element of the control valve 1 .

3 a sectional view showing a nominal position and

4 a sectional view showing a position with axial offset.

The representation of the 1 is a valve housing 1 to remove, which has two mutually perpendicular bores, wherein a bore 5 as feed connection 2 is designed for a cooling medium. In this hole 5 is a sleeve-shaped sealing element 4 arranged, the conical wall sections both in the region of its inner peripheral surface 4.1 , as well as in the area of its outer peripheral surface 4.2 has. An inner peripheral side arranged conical wall portion extends over an end portion 6 of the sealing element 4 , the one valve member 3 facing, so that the sealing element receives a nozzle-shaped inner contour. Due to this inner contour is through the cooling medium, during operation of the valve, the sealing element 4 flows through a hydraulic pressure force causes the sealing element in sealing engagement with the valve member 3 holds. The sealing element 4 lies with his the valve member 3 facing end face on the valve member 3 on, so that this end face an axially acting sealing surface 8th formed. The end face is the outer contour 9 of the valve member 3 adapted, which is part-spherical in the illustrated embodiment. In a switching movement of the control valve, which may be linear and / or rotational, is the frontally disposed, axially acting sealing surface of the sealing element 4 subjected to a dynamic load. In order to reduce the wear of the sealing element, in particular at this dynamically loaded sealing point, the sealing element is made of PTFE, whose particularly low coefficient of friction as low as possible movement of the valve member 3 allows. An additional advantage is that the sealing element 4 has an annular contact surface in the region of the dynamically loaded sealing point, so that the sealing surface is limited to a substantially linear contact area.

Another sealing point, which is also exposed to a certain dynamic load, is between the sealing element 4 and the valve housing 1 educated. The sealing element 4 has for this purpose a radially acting sealing surface 10 on, on a circumferential sealing lip 11 is trained. The sealing lip 11 in turn is on a valve member 3 opposite end portion 7 of the sealing element 4 educated. It is at a radial distance from the sealing element 4 formed on this, so that between sealing lip 11 and sealing element 4 an annular gap 13 is trained. The annular gap 13 opens to the face 12 towards the valve member 3 is turned away, so that during operation of the valve cooling medium in the annular gap 13 passes and the sealing lip 11 acted upon by a hydraulic pressure force which causes the necessary contact pressure. To the sealing lip 11 opposite the hole 5 of the valve housing 1 Furthermore, radially bias, so that a system pressure independent contact pressure is ensured, is also in the annular gap 13 a spreading element 14 used in the form of a sealing ring (see 2 ).

For the axial preload of the sealing element 4 opposite the valve member 3 is also a spring element 15 provided, which in the present case consists of a corrugated spring (see 1 ). The corrugated spring is on the one hand on the end face 12 of the sealing element 4 and on the other hand at an axial stop 16 on the valve body 1 supported.

The inventive control valve allows a permanently secure sealing of the coolant flow paths both in the axial and in the radial direction, so that leakage currents be minimized. Due to the inventive design of the Sealing element is also via hydraulic pressure and / or Impulse forces a self-centering of the sealing element causes.

Manufacturing and / or assembly tolerances can cause the valve member 3 and the sealing element 4 not the in 3 take account of nominal position, but offset from each other are arranged (see 4 ). If this is the case, a sealing system with the formation of a minimum sealing gap can no longer be guaranteed. Does the valve member has a part-spherical outer contour 9 and the sealing element 4 a mating surface adapted thereto as an axially acting sealing surface 8th on, the sealing sleeve centered under the force of the spring element 15 and the fluid pressure itself and can compensate for axial offs by themselves (see 4 ). Here, the sealing element assumes an inclined position, the ver by the conical continuous outer contour of the sealing element 4 is possible. Because the outer contour is chosen such that the radial distance of the sealing element 4 for drilling 5 of the valve housing 1 to the valve member 3 increases and thus sufficient space for taking a skew of the sealing element 4 is available. In the illustrated sealing element 4 is the outer peripheral surface only in a central part of the sealing element 4 formed conically extending and in the region of the valve member facing the end portion 6 again straight out, that is cylindrical. However, the conical shape may also extend to the end face, as the axially acting sealing surface 8th is trained.

1

valve housing

2

supply port

3

valve member

4

sealing element

4.1

Inner circumferential surface

4.2

Outer circumferential surface

5

drilling

6

valve member facing end portion

7

valve member opposite end portion

8th

axial acting sealing surface

9

outer contour of the valve member

10

Radial acting sealing surface

11

sealing lip

12

valve member opposite end face

13

annular gap

14

spreader

15

spring element

16

attack

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 4644909 [0004]

Claims (14)

Control valve for controlling a coolant circuit of an internal combustion engine with a first on a valve housing ( 1 ) arranged feed connection ( 2 ) for cooling water of a bypass circuit and at least one second feed connection ( 2 ) for cooling water of a cooler circuit, which, depending on the position of a valve member housed in the valve housing ( 3 ) are connectable to a discharge port, characterized in that for sealing the coolant flow paths in the axial and / or radial direction in a feed connection ( 2 ) provided bore ( 5 ) of the valve housing ( 1 ) in engagement with the valve member ( 3 ) can be brought, dynamically loadable sealing element ( 4 ) is provided, which is sleeve-shaped and at least over an axially extending portion of its inner peripheral surface ( 4.1 ) and / or outer peripheral surface ( 4.2 ) has a conical shape, so that the free flow cross-section to the valve member ( 3 ) decreases and / or the radial distance of the sealing element ( 4 ) for drilling ( 5 ) of the valve housing ( 1 ) to the valve member ( 3 ) increases. Control valve according to claim 1, characterized in that the axially extending, conically extending portion of the inner peripheral surface ( 4.1 ) on a valve member ( 3 ) facing end portion ( 6 ) of the sealing element ( 4 ) is arranged. Control valve according to claim 1 or 2, characterized in that the axially extending, conically extending portion of the outer peripheral surface ( 4.2 ) spaced from at least one end portion ( 6 . 7 ) of the sealing element ( 4 ) is arranged. Control valve according to one of the preceding claims, characterized in that the sealing element ( 4 ) an axially acting sealing surface ( 8th ), which on a the valve member ( 3 ) facing the end face of the sealing element is formed and the outer contour ( 9 ) of the valve member ( 3 ), which is preferably part-spherical. (Opposing surface) Control valve according to one of the preceding claims, characterized in that the sealing element ( 4 ) a radially acting sealing surface ( 10 ), which on a the valve member ( 3 ) facing away end portion ( 7 ) of the sealing element is formed, wherein the sealing surface ( 10 ) preferably as a sealing lip ( 11 ) is formed. Control valve according to claim 5, characterized in that the sealing lip ( 11 ) to form a ring gap open on one side ( 13 ) at a radial distance to the sealing element ( 4 ), wherein the annular gap ( 13 ) a the valve member ( 3 ) facing away from the end face ( 12 ) of the sealing element ( 4 ) is limited radially. Control valve according to claim 6, characterized in that for the radial prestress of the sealing lip ( 11 ) opposite the bore ( 5 ) of the valve housing ( 1 ) a spreading element ( 14 ) in the annular gap ( 13 ) is arranged. Control valve according to one of the preceding claims, characterized in that the sealing element ( 4 ) to ensure a sealing contact with the valve member ( 3 ) of the pressure force of a spring element ( 15 ), preferably a wave spring, is acted upon, wherein the spring element ( 15 ) at the end face ( 12 ) of the sealing element ( 4 ) is supported. Control valve according to claim 8, characterized in that in the bore ( 5 ) of the valve housing ( 1 ) an axial stop ( 16 ) for supporting the spring element ( 15 ) is trained. Control valve according to one of the preceding claims, characterized in that the sealing element ( 4 ) consists wholly or partly of a thermoplastic plastic, preferably polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE). Control valve according to one of the preceding claims, characterized in that the sealing element ( 4 ) was produced in a spraying or injection molding process, wherein preferably the sealing lip ( 11 ) directly to the sealing element ( 4 ) has been injected. Control valve according to claim 11, characterized in that the outer and / or inner contour of the sealing element ( 4 ) Is designed such that the injection molding tool during removal by a linear and / or rotational movement is easily removable. Control valve according to one of the preceding claims, characterized in that the valve member ( 3 ) is a linearly movable spool and / or rotatably movable rotary valve. Coolant circuit of an internal combustion engine with a control valve according to one of the preceding claims.