EP1164264B1 - Blowby heater - Google Patents

Description

The invention relates to crankcase vents and is particularly concerned with a Blow-heating. Furthermore, the invention relates to an internal combustion engine with such Blow-heating.

The crankcase (also engine block) of an internal combustion engine takes as the most important Crankshaft with crankshaft, connecting rods and pistons. At the bottom, the crankcase usually completed by a bolted sump. Upwards takes place the cover of the cylinder located in the crankcase by one or more Cylinder heads.

The crankcase fills up to the cylinder head with old vapors and gases, which at the Pass the piston rings out of the combustion chamber. The pumping movement of the pistons puts these old fumes and gases under pressure. To protect the environment is an escape prevents these gases.

The escaping fuel gases from the fuel tank burden at a standstill Engine the environment. Therefore, often a combined engine and fuel tank vent present, with the gases and vapors collected in a surge tank gases condense and flow back to the fuel tank. During the Starting the engine sucks the vapors from the expansion tank, and while running Engine, the gases and vapors are passed directly to the air filter.

The gases and old fumes that fill the crankcase are called blowby gases. The main components of the blow-by gas are unburned gases, which are large quantities Contain hydrocarbons.

A defective, clogged or iced vent leads to a high pressure in the crankcase, the lubricating oil from the seals (for example, on the crankshaft, oil pan or out the opening for the dipstick) presses. It creates a large oil loss, the engine damage and leads to an environmental impact.

From US-A-6,062,206 a blow-by heater is known, by which an icing of the Crankcase ventilation can be avoided.

The invention is based on the object, a blow-by heater and an internal combustion engine with such a blowby heater indicate that the icing of the crankcase ventilation prevent.

This object is achieved by the subject matters of the independent claims solved.

The use of PTC heating elements (PTC = Positive Temperature Coefficient) is due to the self-regulating properties of a PTC thermistor for use in a blow-by heater advantageous.

Furthermore, the blowby heater according to the invention is advantageous, since the at least one PTC heating element is glued to the gas-carrying pipe and thereby the use Be prevented by soldering or spring clamps compressive stresses. Furthermore, by gluing the PTC heating elements, the overall structure can be significant be simplified because additional support elements omitted.

By pre-fixing the current guides by plastic extrusion is on the one hand the improved mechanical stability of the power supply and on the other hand, the connection technology in the production advantageously designed so that this faster and thus can be made cheaper.

Another advantage of bonding the PTC heating elements to the gas-carrying pipe is in that for the latter, an aluminum die-cast pipe can be used, what Compared to conventional copper pipes causes a significant cost advantage.

Dos used adhesive material is electrically non-conductive, and in particular it is a silicone adhesive, so are associated with multiple benefits. First, silicone adhesive is temperature resistant and thus just for use in a blowby heater over a large one Temperature range also advantageous. Furthermore, the adhesive has a high elongation at break of up to 300%, which compensates for occurring stresses and manufacturing tolerances can be compensated.

Be at least two PTC heating elements connected to each other electrically conductive are arranged around the gas-carrying pipe around, so the pipe from several sides heated simultaneously and thus uniformly and improves the heat coupling. Will be there riveted a contact, not only the overall stability is promoted in an advantageous manner, but also simplifies the manufacturing process.

An advantage continues to be provided by plastic extrusion of the heating elements and the pipe, because of this extensive freedom in the shaping of the blow-by heater, in particular of the pipe arise. Also, the blowby heater can be in a compact Design and manufacture design, and it will continue the occurrence of mechanical stresses prevented.

Preferred embodiments of the invention are specified in the subclaims.

Fig. 1a und 1b Seitenansichten einer Blowby-Heizung gemäß einer bevorzugten Ausgestaltung der vorliegenden Erfindung zeigen;

Fig. 2a das gasführende Rohr mit anmontierten PTC-Heizelementen gemäß der bevorzugten Ausgestaltung der vorliegenden Erfindung in Draufsicht zeigt;

Fig. 2b die Anordnung von Fig. 2a im anmontierten Zustand mit Sockel und Entlüftungsflansch zeigt;

Fig. 3a die Anordnung von Fig. 2a in perspektivischer Sicht zeigt; und

Fig. 3b die Blowby-Heizung gemäß der bevorzugten Ausgestaltung in perspektivischer Ansicht zeigt.

The invention will be explained in more detail below with reference to the attached drawings, in which:

Figures 1a and 1b show side views of a blowby heater according to a preferred embodiment of the present invention;

Fig. 2a shows in plan view the gas-carrying tube with mounted PTC heating elements according to the preferred embodiment of the present invention;

Fig. 2b shows the arrangement of Fig. 2a in the assembled state with base and vent flange;

Fig. 3a shows the arrangement of Fig. 2a in a perspective view; and

Fig. 3b shows the blow-by heater according to the preferred embodiment in perspective view.

With reference to these figures, a preferred embodiment of the Invention explained in more detail.

FIGS. 1a and 1b show a side view of a blowby heater according to the invention. The order is mounted by means of the base member 10 to the crankcase such that the Blowby gas through the inside connection pipe 20 and through the outside connection element 30 passes through the vent flange 40. That's how it will be done Blowby gas heated according to the invention, including in the interior of the arrangement shown electrically operated PTC heating elements are provided. To these heating elements electrical energy To provide available, the blow-by heater also has an electric Connector 50.

FIGS. 2a and 2b show the heating arrangement located inside the blowby heater become. Around the gas guide tube 90 are in the preferred embodiment of Fig. 2a, three PTC elements 60 arranged. In the preferred embodiment, the PTC elements 60 with the gas guide tube 90 by means of a temperature-resistant, not conductive silicone adhesive having a high elongation at break of about 300%. Although the adhesive per se is non-conductive, but in the manufacture of the shown in Fig. 2a Arrangement pressed the respective PTC element under high pressure to the gas guide tube, so that due to the surface roughness, an electrical contact results. As a result, the mechanical advantages of silicone adhesive, such as Ability to tolerance compensation, exploited, without compromising on the electrical contact to have to go.

The respective rear sides of the PTC elements 60 are electrically connected to a contact strip 70, 80 conductively connected to one of two flat contact pins 110 of the electrical Connector 50 is in contact. The other flat contact pin 110 is connected to the gas guide tube 90 connected via a contact feeder 100, so that a stream of a Contact pin via the PTC elements 60, the gas guide tube 90 and the contact feeder 100 to the other contact pin can flow.

The gas guide tube 90 is preferably an aluminum die-cast tube, but may also be made of another electrically conductive material, such as Copper. Furthermore, in the preferred embodiment of the invention, the contact feeder 100 riveted to the gas guide tube 90. However, other connection techniques may be used Use such as screws, clamps, rivets, welding, gluing etc.

As mentioned above, in the preferred embodiment, the PTC elements 60 are connected to the Gas guide tube 90 by means of the electrically non-conductive silicone adhesive by strong pressure connected, whereby the PTC elements 60 with the gas guide tube 90 electrically get connected. In another embodiment, that does not belong to the invention, becomes a conductive instead of the silicone adhesive Epoxy resin adhesive used in the silver or other metal particles introduced have been. Although this adhesive does not have the advantageous mechanical properties as well as the temperature resistance of the silicone adhesive, however, is in the production the arrangement only a slight pressure on the gas guide tube 90 necessary.

For prefixing the flat contact pins 110 is in the preferred embodiment of the present Invention, a plastic extrusion 120 is provided, the mechanical stability during assembly and possibly also afterwards. Further, in Figs. 2a and 2b, in particular the PTC elements 60 and the gas guide tube 90, after assembly also plastic encapsulated, what the occurrence of mechanical stresses prevents and allows a compact design. Furthermore, this is in the shaping design the gas guide tube 90 extensive freedom offered.

FIGS. 3a and 3b show the arrangements shown in the preceding figures in perspective view. As can be seen from Fig. 3a is in the preferred Embodiment, the contact band 80 between the PTC elements 60 made narrower as the contact band 70, thereby reducing the overall weight of the assembly, and further the contact band 70, 80 becomes more flexible and less thermally conductive.

As mentioned above, in the preferred embodiment of Figs. 2a and 2b are three PTC elements 60 disposed around the gas guide tube 90 around. It can instead also any other numbers of PTC elements 60 may be provided, in particular two or just one PTC element. The selection of the number of PTC elements 60 is directed depending on the required heating power, the cross section and the type of PTC elements used.

Claims (8)

1. Blowby heater comprising:

   a gas-conducting pipe (90) and

   at least one heating element (60),

   wherein the heating element is a PTC heating element, which is connected to the pipe using an electrically non-conducting adhesive material, wherein electrical contacting is produced due to the surface roughness.
2. Blowby heater according to claim 1, wherein the pipe (90) is manufactured by the aluminium pressure die-casting method.
3. Blowby heater according to claim 1, wherein the adhesive material is a silicone adhesive.
4. Blowby heater according to one of claims 1 to 3, wherein at least two PTC heating elements (60), which are connected together electrically conductively, are disposed around the pipe (90).
5. Blowby heater according to one of claims 1 to 4, wherein the PTC elements (60) are connected to electrical contacts (110), of which at least one is riveted to the pipe (90).
6. Blowby heater according to one of claims 1 to 5, wherein the PTC heating elements (60) and the pipe (90) are encased in injection-moulded plastics material.
7. Blowby heater according to one of claims 1 to 6, further comprising electricity supply lines (110), which are pre-fixed by encasing in injection-moulded plastics material.
8. Internal combustion engine with a blowby heater according to one of claims 1 to 7.

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