DE1526649A1 - Thermal protection device on fuel pumps for motor vehicle engines - Google Patents

Description

In motor vehicles, for reasons of vehicle technology and for reasons of simple drive, it is customary to flange the fuel pump to the lower part of the engine housing. The pump is at a short distance from the neighboring motor wall. About their support base it is in heat-conducting connection with the motor housing _o Thus, the heat conduction from the engine to the pump is largely suppressed, an insulating washer is interposed between the fuel pump and the motor, whose shape corresponds to the shape of the flange at the foot of the fuel pump.

The operating temperature of a gasoline engine is between 85 and 95 ° Oo. The heat of the engine housing is absorbed by the aforementioned insulating

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disk only partially prevented from direct "by" heat conduction to pass to the pump foot, since "the fastening screws for the pump still transferring heat by conduction after the pump can. In general, there is no further heat transfer from the engine housing to the fuel pump, because this occurs through the driving wind - and when the vehicle is at a standstill by the jet of the radiator fan - is cooled. This cooling is at Central European Outside temperatures and normal driving speeds are completely sufficient. However, if several unfavorable circumstances come together, for example summer outside temperatures and long idle times of the engine as well as constant starting and stopping, then The engine heats up more than in normal operation, which has the effect that due to insufficient cooling due to lack of Driving wind the heat dissipation is insufficient. For the fuel pump, this means that you have increased convection heat and radiant heat is supplied. It often heats up to such an extent that, due to its construction and the Boiling curve of the fuel to be pumped "empty" and no longer working.

The invention has for its technical object to provide a device which is the Treibstoffpuaipe from excessive heating by the heat of the automobile engine 3ChUtEt ₆ The desired goal even when meeting the above-mentioned unfavorable conditions in as simple as it advantageous and advanced Weiee according to the invention attained in that with a flange-mounted fuel pump between this and the motor housing in from good

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thermally conductive metal _f, for example aluminum, an existing protective plate with the formation of an upward-facing chimney, open on the narrow sides, is attached at a distance from the motor housing, the protective plate only being in contact with aem motor housing and the pump on the pump mounting flange, but otherwise being cantilevered and on all sides the largest area projected by the pump into a plane running parallel to the opposite motor housing wall.

This training ensures that the guard plate the pump shielded from direct heat radiation from the engine and from direct contact with the air heated by the engine protects. The protective sheet is heated up by the radiant heat coming from the motor housing and by the convection heat. Also will it largely absorb the heat transferred from the retaining screws. In the chimney created by attaching the protective sheet, an updraft forms, by means of which heat is extracted from the mudguard, so that this itself is not excessively warm and becomes a new source of heat.

This means that there is strong heat reflection from the mudguard towards the chimney takes place, it is advisable to design the protective plate on the side facing the motor housing to be heat-reflecting, for example to keep it high-gloss. Furthermore, in order to keep the pump largely free of the radiant heat emitted by the protective plate could go out, the latter is favorably received on its side facing the pump in the area of the pump projection surface

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a thermal insulation layer. The latter can be created using a special lacquer or a glass fiber layer. It is also possible the thermal insulation layer by means of a small distance from the mudguard to form on this arranged additional sheet, wherein the space between the sheets is evacuated.

Especially when the motor housing and Fuel pump, it can be advantageous if a cold air that can be operated with the heat of the engine housing or the engine exhaust gases, A cold generator is provided instead of the protective plate, whereby the cold air is then blown to the pump «

The invention is explained below with reference to the drawing, which illustrates an exemplary embodiment.

Pig. 1 the device in side view, FIG. 2 the device in front view, 3 shows the protective plate in plan view.

The fuel pump 2 is connected to the housing 1 of a motor vehicle engine via the flange 3 by means of the screws 4 and 5 of the foot piece 6 attached «Between the fuel pump 2 and the motor housing 1, the protective plate 7 is arranged. It will held by means of the pump fastening screws 4 and 5. Between The usual heat insulating washer 8 is inserted into the protective plate 7 and the foot piece 6.

The protective plate 7 consists of a material that conducts heat well, both

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for example aluminum or copper, runs parallel to the upward directed motor housing wall 9 and protrudes beyond the fuel pump 2 all-round. It is self-supporting and has, for example, a Thickness of 5/4 to 1 mm and should have a total area of not less than 75 and not more than about 150 cm. Pas fender 7 is heat-reflecting on its side 10 facing the motor housing 1 formed, e.g. polished to a high gloss

The protective plate 7 is heated by radiation and convection from the motor housing 1. In addition, the heat transferred via the screws 4 »5 by conduction will flow to a large extent towards the protective plate. The heat generated by radiation from the motor housing 1 is thrown back from the reflective side 10 to about 90 # after the relatively narrow chimney 11 open on the narrow sides, which is formed by the arrangement of the protective plate 7 running parallel to the housing wall 9. In the fireplace 11 a solar chimney, which dissipates the heat to the top where they can no longer interfere with the fuel pump 2 is produced _β

In the area of the pump projection area, i.e. an area that contains the working elements of the pump Pump part arises on a plane running parallel to the housing side 9, on the side facing the fuel pump 2 there is a Thermal insulation layer 12 arranged. This can consist of a special loaf or a glass fiber layer. Of course, it can can also be formed from any other suitable material »In some cases it may be advisable to use a small

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Distance from the fender 7 to this arranged additional sheet form, whereby the space between the two sheets is evacuated »

The heat dissipated by heat conduction via the metal retaining screws is largely absorbed by the protective plate 7 and
Distributed over the entire radiation surface in such a way that relatively little can get to the fuel pump 2. As practice shows, the fuel pump could fail after the
Fender can no longer be reached even under extreme conditions.

When the assembly is closed, i.e. when it is no longer possible to provide a protective plate 7, it may be advisable to provide a cold generator that is activated by the heat from the motor housing
or the engine exhaust is operable and supplies cold air by means of which the fuel pump can be blown on for cooling.

In the case of air-cooled engines, the fuel pump can also be cooled
by switching on a piece of the fuel supply line to the fuel pump through an air flow branched off from the fan, which is passed through a double jacket along a piece of the fuel supply line and simply exits at the foot of the fuel pump into which the fuel line opens.

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Claims (1)

Claims 1β thermal protection device on fuel pumps of motor vehicle engines, the fuel pump being attached to the engine housing, thereby characterized in that when the fuel pump (2) is flange-mounted between this (2) and the motor housing (1), a well-thermally conductive Metal, for example aluminum, existing protective plate (7) with the formation of an upwardly directed, on the narrow sides Open chimney (11) is attached at a distance from the motor housing (1), the protective plate (7) only on the pump mounting flange (3) is in contact with the motor housing (1) and the fuel pump (2), but is otherwise self-supporting and on all sides the largest area projected by the pump into a plane running parallel to the opposite motor housing wall (9) towers. 2 »Thermal protection device according to claim 1, characterized in that that the protective plate (7) on its facing the motor housing (1) Side designed to reflect heat, for example is kept high gloss. 3 heat protection device according to claims 1 and 2, characterized in that that the protective plate (7) on its side facing the fuel pump (2) in the area of the pump projection surface Has thermal insulation layer (12), 4 · Thermal protection device according to claim 3 »characterized in that 909887/0568 that the thermal insulation layer consists of special paint. tj »heat protection device according to claim 3» daduroh characterized, that the thermal insulation layer consists of fiberglass material * 6. WarmeschutZVOrrichtung according to claim 3 »characterized in that that the thermal insulation layer is formed by means of an additional sheet arranged at a small distance from the protective sheet (7), with the hood between the metal sheets evacuated, 7 heat protection devices on fuel pumps of motor vehicle engines, the fuel pump being attached to the engine housing, thereby characterized in that especially with closed assembly of the motor housing and fuel pump with the heat from the motor housing or the engine exhaust gas operable, cold air supplying cold generator is provided and that the cold air to the fuel pump (2) is blowable. 8.Heat 3ciiut ζ device on fuel pumps of motor vehicle engines, characterized in that the leading to the fuel pump Fuel supply within a voir. Fan branched off cooling air line runs. Or β 3