VALVE DEVICE, ESPECIALLY WINDSCREEN WATER VALVE

Description

[0001] The invention relates to a valve device, in particular a washer fluid valve, with a housing having an inlet connection, an outlet connection and a media channel connecting the inlet connection to the outlet connection, and with a displaceable valve element which is urged by a first spring element against a valve seat formed in the housing in order to close the media channel, and which is movable away from the valve seat by a second spring element in order to open the media channel, wherein the first spring element is made of a thermally activatable material and in a deactivated state has a first spring force which is smaller than that of the second spring element, and in an activated state has a second spring force which is greater than that of the second spring element such that the valve element is displaced in order to open the media channel, wherein the first spring element is at least partially arranged in a hollow cylindrical,is held by a housing projection of the housing projecting outwards from the housing, wherein the second spring element is designed as a helical spring, is partially pushed onto an axial projection of the valve body and is held axially prestressed between the valve body and the housing.

[0002] Valve devices of the type mentioned above are already known from the prior art. For example, published patent application EP 3 455 529 A1 discloses a valve device of the generic type. Because such valve devices have a thermally activated spring element that switches depending on the temperature acting on the valve, they are often referred to as a thermal valve or thermal valve device. It is known to arrange such a valve device in a tank of a motor vehicle containing a liquid medium, such as windshield washer fluid, coolant, lubricant, or the like, so that the housing of the valve device is exposed to the medium and thus to the temperature of the medium.The thermally activatable spring element is advantageously arranged in a housing projection which protrudes from the rest of the housing of the valve device, so that the spring element is located as largely as possible outside the housing and inside the tank, so that the thermal energy of the medium in which the valve device is arranged is transferred quickly and with little loss to the spring element, so that the latter reaches its activation temperature promptly and switches, so that it has the increased spring force by means of which the valve element is displaced in the media channel against the valve seat and against the spring force of the second spring element, which acts as a return spring, so that the media channel is tightly closed and thus the connection between the inlet connection and the outlet connection is safely interrupted.For ease of assembly, the above-mentioned prior art provides for the housing to be constructed in several parts, with a division between the inlet connection and the outlet connection.

[0003] Another valve device is known from the published patent application JP 2006 138235 A.

[0004] The invention is based on the object of creating an improved valve device which ensures a long service life with simple means and in particular prevents malfunction of the valve device.

[0005] The object underlying the invention is achieved by a valve device with the features of claim 1. This has the advantage that lateral breaking out or bending of the helical spring is permanently prevented by the structural design of the valve device. The design of the valve device can be implemented cost-effectively and with little effort. Advantageous coordination of the axial projection and media channel ensures that the helical spring is guided radially over its entire length, so that it has little play in the radial direction along its entire length, which reliably prevents bulging or lateral buckling as well as jamming of the helical spring in the valve device. According to the invention, it is provided for this purpose that the helical spring is guided radially by the axial projection of the valve body and / or by an inner wall section of the media channel.The axial projection, onto which the coil spring is mounted, guides the coil spring radially inward. The inner wall section of the media channel guides the coil spring radially outward. The clever design of the axial projection and inner wall section ensures that, regardless of the operating state of the valve device, the coil spring is always guided radially along its entire length by the axial projection or the inner wall section, or both.

[0006] Preferably, the axial projection is designed to be so long that, when the first spring element is deactivated, it projects so far into the media channel that it partially lies opposite the inner wall section. This ensures that, both when the first spring element is deactivated and when the first spring element is activated, the axial projection partially lies opposite the inner wall section of the media channel, so that in every operating state of the valve device it is guaranteed that the helical spring is radially guided either externally or internally. In the region in which the axial projection lies opposite the inner wall section, so that a radial gap remains between them, the helical spring is then guided both internally and externally by the axial projection and the inner wall section. This structurally simple measure permanently ensures reliable operation of the valve device.

[0007] Particularly preferably, a remaining radial gap between the inner wall section and the axial projection is larger than the spring wire diameter of the coil spring. Thus, the coil spring has radial play in the annular channel formed by the radial gap, reliably preventing jamming of the coil spring in the radial gap.

[0008] Furthermore, it is preferably provided that the housing projection has a heat-conducting mandrel on its free side facing away from the housing, which protrudes into the housing projection in the direction of the valve element and thereby forms an annular receiving pocket for a longitudinal section of the spring element in the housing projection. This has the advantage that heat input into the first spring element through the housing projection is improved. In particular, the spring element is now not only exposed to the thermal energy of the surrounding medium from one side, namely from outside the housing projection, but also from within the housing projection. This results in early switching or activation of the thermally sensitive first spring element (thermal spring element), so that switching of the valve device is ensured promptly after the activation temperature is reached by the surrounding medium.Because the heat-conducting mandrel protrudes into the housing projection, the section of the spring element located in the receiving pocket is exposed to the temperature of the medium both from the outside, i.e. through an outer wall of the housing projection, and from the inside through the heat-conducting mandrel. If the heat-conducting mandrel is solid, heat is conducted through the material of the heat-conducting mandrel into the interior of the housing. An advantageous choice of material ensures good heat transfer and high thermal conductivity, which enables early switching of the valve device. According to a preferred development of the invention, the first spring element is designed as a helical spring, which is attached to the housing projection on the heat-conducting mandrel.Due to its design as a helical spring, the spring element has a ring-shaped, in particular circular, cross-section whose inner diameter is larger than the outer diameter of the heat-conducting mandrel, such that the helical spring can be pushed onto the heat-conducting mandrel and inserted into the receiving pocket. In addition to the previously described advantageous heat transfer to the first spring element, this also results in the advantage of secure axial guidance and alignment of the helical spring in the housing of the valve device. Furthermore, the advantageous design of the first spring element with the aid of the heat-conducting mandrel facilitates the assembly of the valve device. Furthermore, it is preferably provided that the heat-conducting mandrel is designed as a cup-shaped hollow mandrel open towards the end face of the housing projection.This allows the surrounding medium to penetrate into the heat-conducting mandrel itself, so that the surrounding medium not only surrounds the first spring element from the outside, but is also present inside the coil spring, namely within the hollow area of the heat-conducting mandrel. This results in an even more direct heat transfer from the medium into the spring element or coil spring from two sides, namely from the outside and from the inside, ensuring even earlier switching of the valve device. The heat-conducting mandrel is preferably made of a material with a high thermal conductivity value. For this purpose, the heat-conducting mandrel is made of aluminum, silver, copper, or gold, for example. This advantageous choice of material further optimizes or shortens the switching time of the valve device after the surrounding medium has reached the activation temperature.Furthermore, the housing projection is preferably formed by a housing flange that protrudes from the rest of the housing and a cover arranged on the end face of the housing flange, wherein the heat-conducting mandrel is arranged on the cover. The two-part design of the housing projection offers easy assembly of the valve device. Thus, the second spring element, the valve element and the first spring element can be inserted one after the other through the housing flange into the media channel and then the media channel or the housing can be closed by the cover. The advantageous design of the heat-conducting mandrel and the resulting receiving pocket for the first spring element, in particular in the form of a helical spring, ensures secure and easy guidance of the cover towards the housing flange during assembly, which in particular prevents the helical spring from buckling or tilting laterally during assembly.Particularly preferably, the heat-conducting mandrel is formed integrally with the cover, ensuring advantageous heat conduction through the cover into the heat-conducting mandrel. Particularly preferably, the cover is integrally connected to the housing flange, ensuring, on the one hand, the tightness of the housing to the surrounding medium, and, on the other hand, ensuring advantageous heat conduction at the interface between the cover and the housing flange. This allows the thermal energy of the surrounding medium to act on the spring element arranged therein, even in the area of the housing flange, to enable early switching of the valve device.

[0009] Furthermore, it is preferably provided that the coil springs are axially aligned with the media channel, and the valve element is mounted axially displaceably within the media channel. This results in advantageous assembly, and the coil spring acts directly between the valve element and the housing, pressing the valve element axially against the valve seat.

[0010] Furthermore, the valve device is preferably designed such that the inlet connection and / or the outlet connection open radially into the media channel. This ensures an advantageous arrangement of the connections and the media channel as well as the valve element in the housing, in which the inlet connection can be reliably separated from the outlet connection by the valve element.

[0011] Furthermore, it is preferably provided that the valve element is located in the media channel, at least substantially independently of its sliding position, at least in sections in the region of the inlet connection, i.e. in the region of the media channel in which the inlet connection opens into the media channel. Thus, the valve element is always located in the region of the inlet connection, so that it is surrounded or wetted by the medium to be controlled or switched, whereby, on the one hand, the pressure of the medium to be switched also acts on the valve element in the closing direction, and, on the other hand, the supplied medium prevents, in particular, an optionally provided sealing element from drying out.

[0012] Particularly preferably, the valve element has a cup-shaped receiving recess in which the helical spring or the first spring element is arranged in certain areas. The receiving recess ensures secure mounting of the helical spring on the one hand and secure actuation of the valve element by the first spring element on the other. The helical spring or the first spring element is held preloaded between the valve element and the cover of the housing flange or the housing projection, regardless of whether it is activated or not. This ensures a clear storage position of the valve element because it is always subjected to a spring force by the first and second spring elements, regardless of the activation state of the first spring element.

[0013] According to a preferred development of the invention, the valve element has a cross-section that increases in the direction of the first spring element and the media channel has a cross-section that increases in the direction of the housing projection, so that the valve element and the screw can be axially inserted into the media channel through a front opening in the housing projection, in particular the housing flange. The cross-sectional enlargement of the valve element and media channel in the direction of the housing projection ensures simple assembly of the valve device. Optionally, the valve element and / or the media channel have one or more undercuts - viewed in the direction of insertion into the media channel - but without the valve element engaging behind the media channel in the insertion direction. Rather, the undercuts or recesses or tapers then serve to improve media conduction.

[0014] Preferably, a leakage gap is present between the valve element and the housing projection. The leakage gap ensures that some of the medium supplied through the inlet connection, which flows through the inlet connection into the media channel, reaches the interior of the housing projection, in which the first spring element is also located at least in section. This ensures that the housing projection is filled with medium, which improves the heat transfer from the housing projection and in particular also from the heat-conducting mandrel into the first spring element. Because there is only one leakage gap, i.e. a gap that only allows a small flow, the housing projection essentially contains stagnant medium, the temperature of which can change quickly with the temperature of the surrounding medium and thus switch the first spring element.Furthermore, the space of the housing containing the helical spring is preferably permanently fluidically connected to the media channel, in particular to the inlet connection, through the leakage opening. This results in the aforementioned advantage that a medium is located in the interior of the housing projection, which advantageously acts to conduct heat into the first spring element.

[0015] Preferably, a particularly annular sealing element, in particular an elastomer element, preferably an O-ring, is arranged on the valve element and is designed to interact with the sealing seat upon activation of the first spring element. The sealing element is then located between the sealing seat and the valve element, so that its elastic deformability ensures a secure seal of the media channel. The sealing element is preferably arranged on a step of the valve element so that it is held positively on the valve element in the axial direction, thus ensuring even high contact forces of the sealing element against the sealing seat.

[0016] Preferably, the valve element has at least one radial projection at its end facing the housing flange, which is designed to interact with a step formed in the media channel as an axial stop in the direction of the sealing seat. Thus, the sealing seat itself does not form the axial stop for the valve element, which limits the maximum penetration depth of the valve element in the media channel. Instead, the radial projection interacts with the step, which is arranged at an axial distance from the sealing seat. The axial stop or the radial projection and the step of the media channel ensure that the impact and loading of the sealing seat, in particular of an elastically deformable sealing element acting between the sealing seat and the valve element, is limited, thus preventing overloading of the sealing element in a simple manner.

[0017] Furthermore, the sealing element is preferably arranged axially spaced from the radial projection on the valve element, so that the sealing element and the radial projection act independently of one another and, in particular, the above function is ensured that a maximum elastic deformation of the sealing element is limited by the radial projection.

[0018] Furthermore, it is preferably provided that the inlet connection opens into the media channel between the step and the valve seat. Thus, the inlet connection is located between the valve seat and the radial projection of the valve element, ensuring that, in the closed state of the valve device, when the valve element is pressed against the sealing seat, the medium to be switched / regulated flows around it, allowing the medium to penetrate into the housing projection through the aforementioned optional leakage gap.

[0019] Furthermore, it is preferably provided that the radial projection is designed to interact with a front end of the housing projection as an axial stop. Thus, the movement of the valve element in both sliding directions is preferably limited by the radial projection: in one direction by the interaction of the radial projection with the step of the media channel, and in the other direction by the housing projection or with the cover. As a result, the sliding path of the valve element in the media channel is defined in a form-fitting manner, thus preventing misalignment of the valve element and ensuring a long service life of the valve device.

[0020] Particularly preferably, the valve seat is formed as a chamfer in the media channel. The chamfer ensures a secure pressing of the valve element, in particular the sealing element, onto the valve element, thereby ensuring a secure sealing of the media channel when the first spring element is activated.

[0021] The invention will be explained in more detail below with reference to the drawings. Figure 1 shows an advantageous valve device in a first switching state, Figure 2 shows the valve device in a second switching state, each in a simplified longitudinal sectional view, and Figure 3 shows a perspective exploded view of the valve device.

[0022] Figure 1shows, in a simplified sectional view, an advantageous valve device 1 for installation in a tank, for example for windshield washer fluid of a motor vehicle. The valve device 1 has a housing 2, which has an inlet connection 3 and an outlet connection 4 for a liquid and / or gaseous medium. The inlet connection 3 and the outlet connection 4 are designed as channels in the housing 2 that are aligned parallel to one another and open into a media channel. The inlet connection 3 and the outlet connection 4 are aligned radially or perpendicularly to the longitudinal extent of the media channel 5, which in this case runs straight, so that they also open radially into the media channel 5 at an axial distance from one another. The media channel 5 is closed at one end on the side of the outlet opening 4, and at the other end, the media channel 5 leads into a housing projection 6 that protrudes from the housing 2.The housing projection 6 has a housing flange 7 formed integrally with the housing 2 and projecting in the axial extension of the media channel 5, which is closed at the front by a cover 8. The cover 8 is cup-shaped in longitudinal section, so that the cover 8, together with the housing flange 7, forms an interior space 9 that is aligned with the media channel 5.

[0023] The housing flange 7 has a cross-section that is larger than that of the media channel 5 running in the housing 2, wherein the media channel 5 itself has two steps 10 and 11 that taper the cross-section in the direction of the drain connection 4. The step 10 borders the inlet connection 3 on the side of the media channel 5 facing the drain connection 4. The step 11 lies between the step 10 and the drain connection 4 in the media channel 5. Preferably, the steps 10 and 11 are formed entirely in the media channel 5, so that they each extend completely annularly over the circumference of the media channel 5. In Figure 1 It is shown as an example that the stop of step 11 can also extend only partially over the circumference of the media channel 5. The optional complete extension is shown in Figure 1 indicated by dashed lines.

[0024] In the area of the inlet connection 3 and the housing projection 6, a piston-shaped valve element 12 is arranged, which is axially displaceable relative to the media channel 5. The valve element 12 has an axial projection 13 at one end, which is designed to penetrate into the media channel 5 in the direction of the outlet connection 4. The axial projection 13 has, at a distance from its free end, a step 14 which increases the cross-section and serves as an axial stop for a spring element 15. The spring element 15 is designed here as a helical spring, which is supported at one end on the step 14 and at the other end on the step 11 of the housing 2. The helical spring is held in an axially prestressed manner between the valve element 12 and the housing 2, such that the spring element 15 applies a spring force to the valve element 12 in the direction of the cover 8.

[0025] On the side of the step 14 facing away from the free end face, the valve element 12 has a further step 16, which has a larger cross-section than the step 14. Between the steps 14 and 16, an annular recess 17 is formed as a circumferential groove in the valve element 12. An annular sealing element 18 is arranged in this recess 17 and is held axially and positively to the valve element 12 by the steps 14 and 16. The sealing element 18 is designed as an elastically deformable sealing element, in particular as an elastomer element, in this case in the form of an O-ring, whose inner diameter is smaller than the outer diameter of the smaller step 14.

[0026] The sealing element 18 has a diameter that essentially corresponds to the diameter of the step 10, wherein the valve element 12 can be pushed into the media channel 5 with the end 13 so far that the sealing element 18 is pressed against the step 10, thereby interrupting a fluid connection between the inlet connection 3 and the outlet connection 4 or closing the media channel 5 between the inlet opening 3 and the outlet connection 4. The step 10 thus forms a valve seat 19 for the sealing element 18 of the valve element 12.

[0027] At the end remote from the axial projection 13, the valve element 12 has an axial receiving recess 20, which is opposite the cup-shaped recess of the cover 8. Furthermore, this end has a radial projection 21, which preferably extends over the entire circumference of the valve element 12, which is at least substantially rotationally symmetrical. The radial projection 21 serves as an axial stop on the end face 22 of the cover 8 facing the housing 2. The outer radius of the radial projection 21 is slightly smaller than the inner diameter of the housing flange 7, so that the valve element 12 is axially displaceable in the housing flange 7, with the radial projection 22 serving to radially guide the valve element 12.However, because the outer diameter of the radial projection 21 is slightly smaller than the inner diameter of the housing flange 7, a leakage gap is ensured through which a medium can flow past the radial projection 21.

[0028] The cover 8 is cup-shaped and thus extends the housing projection 7. For this purpose, the cover 8 has a cylindrical projection 23 which extends in alignment with the receptacle 20 of the valve element 12 and ends at the projecting end face 22 of the cover 8, which is opposite the housing flange. The end of the cover 8 or of the projection 23 facing away from the housing flange 7 is closed, giving the cover 8 its cup shape, with a heat-conducting mandrel 25 formed in the free and closed end face 24 of the projection 23, which extends as a hollow mandrel into the projection 23 in the direction of the housing flange 7. The heat-conducting mandrel 25 is formed coaxially with the projection 23, such that an annular receiving pocket 26 is formed between the heat-conducting mandrel 25 and the projection 23.The heat-conducting mandrel 25 is open toward the end face 24, allowing a medium surrounding the housing 2 to flow into the heat-conducting mandrel 25. According to an alternative embodiment, the heat-conducting mandrel 25 is closed, in particular solid. Advantageously, the heat-conducting mandrel 25 is formed integrally with the cover 8, wherein the heat-conducting mandrel 25 is made of a material with a high thermal conductivity value, such as silver, gold, copper, or aluminum.

[0029] A spring element 27 is axially preloaded between the valve element 12 and the cover 8. For this purpose, the spring element 27 is designed as a helical spring, which axially rests at one end against the bottom of the receptacle 20 of the valve element 12 and at the other end against the bottom of the receiving pocket 26. For this purpose, the helical spring is partially inserted into the receiving pocket 26 or placed onto the heat-conducting mandrel 25, so that the latter extends into the helical spring.

[0030] The coil spring is made of a thermally activated material, for example, a shape memory alloy, so that the spring element 27 has two states with different spring forces. Below an activation temperature, the spring element 27 has a first spring force that is lower than the spring force of the spring element 15. In the first state, the spring element 15 thus urges the valve element 12 into the Figure 1shown position, in which the sealing element 18 is arranged at a distance from the sealing seat formed by the step 10 in the media channel 5, so that the connection between the inlet connection 3 and the outlet connection 4 is established and a medium supplied to the inlet connection flows through the valve device, as indicated by the arrows in Figure 1shown. The medium is, for example, the coolant from a coolant circuit of the motor vehicle (not shown in detail here). If the activation temperature of the spring element 27 is exceeded, the spring element 27 is activated and thus has a spring force that is greater than that of the spring element 15. As a result, the valve element 12 is pushed by the spring force of the now activated spring element 27 against the spring force of the spring element 15 with the sealing element 18 against the valve seat 19, so that the media channel 5 is closed and the connection between the inlet connection 3 and the outlet connection 4 is interrupted, as shown in Figure 2 shown as an example.

[0031] Figure 2 shows the valve device 1 from Figure 1 in the second switching state, also in a sectional view. Figure 1Already known elements are therefore provided with the same reference numerals. As already mentioned at the beginning, the valve device 1 is arranged or can be arranged in a tank which serves to store a particularly liquid operating medium, such as an oil tank, fuel tank, exhaust gas aftertreatment tank or windshield washer fluid tank. Thus, when used as intended, the housing 2 of the valve device 1 is surrounded by a particularly temperature-controlled medium. Through the advantageous heat-conducting mandrel 25, the medium also reaches an area within the spring element 23, so that the spring element 23 is subjected to the thermal energy of the medium surrounding the valve device 1 both radially from the outside and radially from the inside.

[0032] Regardless of the sliding position of the valve element 12, a leakage gap 28 is always present between the valve element 12 and the housing 2, through which the medium coming from the inlet connection 3 can enter the interior space 9 and thus also into the interior of the cover 8. During normal operation, this results in the interior of the housing projection 6 containing liquid or liquid medium, which also serves as a heat exchanger. Thus, heat is transferred from the surrounding medium through the cover 8, which is made of a material with high thermal conductivity, into the medium in the interior space 9 of the housing projection 6 and / or directly into the spring element 27.The advantageous design, particularly of the heat-conducting mandrel 25, ensures that the spring element 27 is heated particularly quickly by the surrounding medium to the temperature of the surrounding medium, thereby, for example, exceeding the activation temperature particularly quickly. Thus, a timely switching process of the heating device 1 takes place depending on the temperature of the surrounding medium.

[0033] The radial projection 21 of the valve element 12 is axially displaceable between the cover 8 and a step 29 formed in the housing flange 7. The radial projection 21 and the step 29 are designed such that they limit maximum deformation of the sealing element 18. This ensures, on the one hand, a tight fit of the sealing element 18 on the housing 2 when the activation temperature of the spring element 27 has been exceeded, and at the same time, it is ensured that the sealing element 18 is not overloaded, thereby ensuring a long service life of the valve device 1. The fact that the valve element 12 is located in the area of the inlet connection 3 ensures that the sealing element 18 is also permanently wetted by the medium supplied through the inlet connection 3, thus preventing the sealing element 18 from drying out. For this purpose, even in the closed state of the valve device 1, as shown in Figure 2shown, an opening 30 between the valve element 12 and the housing 2, which leads to the sealing element 18.

[0034] The axial projection 13 of the valve element 12 is furthermore designed to be so long that the helical spring of the spring element 15 is always guided or held and supported radially over its entire length either by the end 13 of the valve element 12 and / or by the inside of the media channel 5 in the housing 2. In the open state, as in Figure 1As shown, i.e., as long as the activation temperature of the spring element 27 has not been exceeded and the spring element 27 is not activated, the axial projection 13 projects into the area of the media channel 5 downstream of the step 10, in which area the helical spring of the spring element 15 is guided on an inner wall section 31 of the media channel 5. This overlap or mutual adjacency of the radial guides of the helical spring in the axial direction ensures that the helical spring 15 is always guided in the media channel and cannot buckle, tilt, or jam.

[0035] The Figure 3shows the valve device 1 in a simplified perspective exploded view. Here it can be clearly seen that the advantageous design of the valve device 1 also allows for simple assembly. The cross-section of the media channel 5, which increases in the direction of the cover 8, and the cross-section of the valve element 12, which also increases substantially in the direction of the cover 8, ensure that during assembly first the spring element 15, then the valve element 12 with the sealing ring 10 and then the spring element 27 can be inserted through the housing flange 7 into the media channel 5. The advantageous receiving pocket 26 in the cover 8 ensures that when the cover 8 is pushed onto the spring element 27 and the spring elements 27 and 15 are thereby pretensioned, in particular the spring element 27 cannot break out laterally or become detached from the cover 8 during assembly.

[0036] According to the present embodiment of the Figures 1 to 3 The valve device 1 also has an advantageous assembly aid 34, which, for example, makes it easier for the fitter to hold the valve element 12 pushed into the interior 9 of the housing flange 7 against the spring force of the spring element 15 during assembly of the valve device 1, so that the spring element 27 and in particular the cover 8 can be fastened to the free end of the housing flange 7 without any particular effort. The assembly aid 34 particularly prevents any or high spring tension of the spring elements 15 and 27 from acting on the cover 8 during assembly of the cover 8, so that the cover 8 can also be glued or welded to the housing flange 7, for example, without the need for additional clamping devices on the cover 8 and / or housing flange 7.

[0037] The assembly aid 34 has a circumferential groove 32 in the outer side of the valve element 12, which lies axially between the step 16 and the radial projection 21 of the valve element 12. In particular, the circumferential groove 32 is formed close to the step 16 in the axial extension of the valve element 12. The position of the circumferential groove 32 is selected in particular such that in the inserted state of the valve element 12, in which it rests in particular against the sealing surface 19, the circumferential groove 32 lies at the level of the inlet connection 3, as in Figure 2 shown. During assembly of the valve device 1, a tool 33 can be inserted through the inlet connection 3 into the housing 2 in such a way that it engages in the circumferential groove 32, as shown for example in Figure 2shown with dashed lines. For this purpose, for example, a tool in the form of an open-end wrench or spanner can be used, which can be pushed onto the valve element 12 in the area of the circumferential groove 32, so that the open-end wrench lies in particular in an axially form-fitting manner in the circumferential groove 32 and thereby counteracts the spring force of the spring element 15 and thereby prevents displacement of the valve element 12 in the direction of the cover 8. After the cover 8 has been mounted on the housing flange 7, the tool 33 can be removed again and the spring force of the spring element 15 can be released or exerted on the valve element 12.

Claims

1. Valve device, in particular a wiper liquid valve, with a housing (2) which comprises an inlet connection (3), an outlet connection (4) and a media channel (5) connecting the inlet connection (3) to the outlet connection (4), and with a displaceable valve element (12) which is urged against a valve seat (19) formed in the housing (2) by a first spring element (27) in order to close the media channel (5), and which is urged away from the valve seat by a second spring element (15) in order to open the media channel (5), wherein the first spring element (27) is made of a thermally activatable material and comprises, in a deactivated state, a first spring force which is smaller than that of the second spring element (15), and, in an activated state, a second spring force which is greater than that of the second spring element (15) such that the valve element (12) is displaced to close the media channel (5), wherein the first spring element (27) is held at least partially in a hollow cylindrical housing projection (6) protruding outwards from the housing (2), and wherein the second spring element (15) is designed as a helical spring, is partially pushed onto an axial projection (13) of the valve body (12) and is held in axial preload between the valve body (12) and the housing (2), characterised in that the helical spring is guided radially over its entire length by the axial projection (13) of the valve body (12) and / or by an inner wall section (31) of the media channel (5).

2. Valve device according to claim 1, characterised in that the axial projection (13) is designed to be so long that, in the deactivated state of the first spring element (27), it projects so far into the media channel that it lies partially opposite the inner wall section (31).

3. Valve device according to one of the preceding claims, characterised in that a remaining radial gap between the inner wall section (31) and the axial projection (13) is larger than a spring wire diameter of the helical spring.

4. Valve device according to one of the preceding claims, characterised in that the housing projection (6) comprises, on its free front side (24) facing away from the housing, a heat conducting mandrel (25) which protrudes into the housing projection (6) in the direction of the valve element (12) and thereby forms an annular receiving pocket (26) for a longitudinal section of the first spring element (27) in the housing projection (6), wherein the heat conducting mandrel (25) is designed as a cup-shaped hollow mandrel open towards the front side (24) of the housing projection (6).

5. Valve device according to claim 4, characterised in that the first spring element (27) is designed as a helical spring which is attached to the heat conducting mandrel (25) in the housing projection (6).

6. Valve device according to claim 5, characterised in that the helical springs are aligned axially with the media channel (5) and the valve element (12) is axially displaceably mounted in the media channel (5).

7. Valve device according to one of the preceding claims, characterised in that the inlet connection (3) and / or the outlet connection (4) open radially into the media channel (5).

8. Valve device according to one of the preceding claims, characterised in that the valve element (12) is located at least substantially independently of its sliding position at least partially in the region of the inlet connection (3) in the media channel (5).

9. Valve device according to one of the preceding claims, characterised in that the valve element (12) comprises a cross-section which increases in the direction of the first spring element (27), and in that the media channel (5) comprises a cross-section which increases in the direction of the housing projection (6), so that the spring elements (15, 27) and the valve element (12) can be inserted into the media channel (5) through an opening in the housing projection (6).

10. Valve device according to one of the preceding claims, characterised in that a leakage gap (28) is provided between the valve element (12) and the housing projection (6).

11. Valve device according to one of the preceding claims, characterised in that an in particular annular sealing element (18), in particular an elastomer element, preferably an O-ring, is arranged on the valve element (12) in order to interact with the valve seat (19).

12. Valve device according to claim 11, characterised in that the valve element (12) comprises at least one radial projection (21) at its end facing away from the sealing element (18), which is configured to interact with a shoulder (29) formed in the media channel (5) at an axial distance from the valve seat (19) as an axial stop in the direction of the valve seat (19).

13. Valve device according to claim 12, characterised in that the sealing element (18) is arranged axially spaced apart from the radial projection (21) on the valve element (12).

14. Valve device according to one of claims 12 or 13, characterised in that the inlet connection (3) opens into the media channel (5) between the shoulder (29) and the valve seat (19).

15. Valve device according to one of claims 12 to 14, characterised in that the radial projection (21) is configured to interact with a front end of the housing projection (6) as an axial stop.