Non-return valve with anti-icing protection

Abstract

Check valve (1) with a valve disc (9) and associated spring sections (8) in a one-piece design, wherein the check valve (1) is integrated inside a heat-conducting heated pipe (2) as protection against icing wherein the valve disc (9) seals off a fluid flow (13) in the relaxed state of the check valve (1), as well as the valve plate (9) lifts off in the event of a fluid flow (14) from the opposite direction and the fluid flow (14) can then flow through the check valve (1) against the spring force of the spring sections (8), characterized in that the valve plate (9) is designed as an inner disc which is connected via the spring sections (8) to an outer retaining ring (7) which serves as a fastening in the tube (2).

Description

[0001] The invention relates to a check valve with anti-icing protection. A check valve with the features specified in the preamble of claim 1 is known from US Pat. No. 6,044,829 A. Similar check valves are known from DE 40 25 732 A1 and DE 89 00 761 U1. Such valves are used in lines for gaseous fluids when icing is a risk due to low ambient or fluid temperatures. For example, such valves are used to vent crankcases in motor vehicles, where water can condense and freeze in the fluid lines, the valve bodies, and the valve seats. Icing can then lead to a restriction in the function of the crankcase ventilation.

[0002] Separate heated valves are known. These are located at the end of a blowby line and are heated by heat-conducting components, in particular a highly heat-conducting line wall, through the heating of the blowby line. A heated poppet valve, for example, is known from DE 103 50 791 A1. The disadvantage of this is the high installation effort.

[0003] The task is therefore to develop a valve design that is reliably protected against icing with little installation effort.

[0004] The task is solved by the check valve being designed to be particularly simple and therefore low-mass and being integrated into a heated pipe section.

[0005] Advantageously, the check valve is designed in the simplest way as a single piece, with an outer fastening ring serving as a fastening in the heated line section, an inner disc as a valve plate with a valve seat and connecting sections between the fastening ring and the valve plate being designed as springs.

[0006] In a preferred embodiment, the heated line section is part of a blowby line. The heated section extends above and below the check valve. The check valve is in thermally conductive contact with the line's heating element via the highly heat-conducting wall of the heated line section. For particularly good and rapid heat transfer, the check valve is advantageously positioned at the height of the heating element, as seen in the direction of flow. A pipe wall made of copper or aluminum is particularly suitable. Thanks to a heating section above and below the heating element and the check valve, the check valve is so well connected to the line heating that a separate valve heating system is no longer necessary.

[0007] In another design variant, good heat conduction between the line heater and the check valve can be dispensed with. To achieve this, at least the metallic surface of the valve seat is coated with a water-repellent layer. A coating containing nanoparticles is particularly suitable for this purpose.

[0008] As a further alternative, the check valve has its own current paths. In a preferred embodiment, the not entirely closed outer fastening ring, together with the connecting sections, i.e., the spring elements, itself serves as the current path. In another preferred embodiment, the valve disk with the valve seat also has current paths, which can be printed there. In one embodiment according to the invention, insulating layers are applied above and / or below the current paths.

[0009] For power supply, the current paths can be connected to an existing electrical line heating element. In a highly preferred embodiment, the current paths of the check valve are connected in series with an existing PTC heating element as line heating. This advantageously reduces the valve heating by regulating the PTC element at elevated temperatures, preventing overheating.

[0010] As a further alternative design variant, electrically insulated heating wire windings are applied to the heat-conducting line wall instead of the valve's own current paths. The associated connecting lines can, in turn, be connected to an existing electrical line heater; here, too, a series connection with a PTC line heater can protect the heating wire windings from overheating.

[0011] All variants have the advantage that the check valve is integrated into a heated line section, thus the assembly effort is low and the integral arrangement of the check valve in the heated line section ensures that the check valve functions much faster after the engine is started.

[0012] Further advantages and features emerge from the accompanying drawings, in which embodiments of the check valve according to the invention are shown.

[0013] Fig. 1 shows a first embodiment of the inventive object, in which a heat-conducting tube 2 is encased in a plastic overmold 3. A PTC heating element 4, electrically insulated by insulation 5, is connected to the tube in a heat-conducting manner. Inside the tube 2, a check valve 1 with its fastening ring 7 is also fixed to the tube 2. The check valve 1 rests on an annular wall 2a with its fastening ring 7, its spring sections 8, and the valve seat 10. The check valve 1 is connected to the tube 2 in a heat-conducting manner via this annular wall 2a. When the check valve 1 is in the relaxed state, the valve plate 9 seals off the fluid flow 13. In the case of a fluid flow 14 from the opposite direction, however, the valve plate 9 lifts off, and the fluid flow 14 can flow through the check valve against the spring force of the spring sections 8.

[0014] Fig. 2 shows a similar design as Fig. 1, but here, additional insulated heating wire windings 6 are attached to the outside of the pipe 2. This results in additional heating of the pipe in the area of ​​the check valve, which also leads to faster heating of the check valve. However, with a series connection of heating wire windings and a PTC element, overheating cannot occur due to the regulating effect of the PTC heating element.

[0015] Fig. 3 and Fig. 4 show further variants, whereby the check valve 1 itself has current paths 12, which are connected by their ends 11 to a power supply. Preferably, the current paths 12 are connected to the power supply of a Fig. 1 and Fig. 2 shown PTC heating element is connected in series to prevent overheating. While in Fig. 3 only the not completely closed fastening ring 7 and the spring sections 8 have current paths 12, in a design according to Fig. 4 also additional current paths 12 are printed on the valve plate 9, which are electrically insulated upwards and downwards.

Claims

[1] Check valve (1) with a valve plate (9) and spring sections (8) connected thereto in a one-piece design, wherein the check valve (1) is integrated inside a heat-conducting heated pipe (2) as protection against icing wherein the valve plate (9) seals a fluid flow (13) in the relaxed state of the check valve (1), and the valve plate (9) lifts off when a fluid flow (14) comes from the opposite direction and the fluid flow (14) can then flow through the check valve (1) against the spring force of the spring sections (8), characterized by , that the valve plate (9) is designed as an inner disc which is connected via the spring sections (8) to an outer fastening ring (7) which serves as a fastening in the pipe (2). [2] Check valve according to claim 1, characterized by that the check valve (1) is connected to the pipe (2) with good heat conduction. [3] Check valve according to claim 1 or 2, characterized by that the check valve (1) has a water-repellent coating, in particular one comprising nanoparticles, at least in the region of the valve seat. [4] Check valve according to at least one preceding claim, characterized by that the check valve (1) itself has current paths for heating. [5] Check valve according to claim 4, characterized by that the current paths are connected to the voltage supply of an electrical line heater. [6] Check valve according to claim 5, characterized by that the current paths are connected in series with a PTC line heater. [7] Check valve according to at least one preceding claim, characterized by that additional heating coils are attached to the pipe in the area of ​​the valve fastening. [8] Check valve according to claim 7, characterized bythat the heating coils are connected in series with a PTC line heater.

Images