DE102008048793A1 - Method for manufacturing plastic oil pan of thermoplastic, particularly for internal-combustion engine or gear, involves welding oil pan that is made of multiple individual units at fusion zones - Google Patents

Abstract

The method involves welding an oil pan (1) that is made of multiple individual units at fusion zones. The individual units of the oil pan are connected along the fusion zones by a hot-gas welding in an inseparable manner. The individual units are made of a polyamide and reinforced glass-fiber.

Description

Technical area

The The invention relates to a method for producing an oil pan made of plastic for internal combustion engines by hot gas welding. The oil pan can be below the crankshaft range of the Engine or under the transmission of a vehicle or a stationary Internal combustion engine can be arranged.

State of the art

in the Prior art oil pans are known plastic, which are composed of several parts. Usually is used for welding plastic parts in the field of internal combustion engines used the vibration welding method in which the Plastic parts are moved vibrating under pressure.

From the EP 1264970 B1 is to remove an oil pan, which is made of an outer shell and an inner shell. The inner shell made of plastic is inserted into the outer shell made of metal. The outer shell carries the inner shell.

The document EP 0872632 A1 discloses an oil sump made of thermoplastic material. The sump consists of an inner and an outer shell, which are welded together by vibration welding. The outer shell envelops the inner shell to the outside, so that only the inner shell is oil-tight.

From the EP 1416129 A1 is a method for producing an oil pan made of plastic, in which an oil filter is welded by vibration welding. The one-piece oil sump forms in its contour while a lower part of the filter housing. The corresponding second part of the filter housing is welded as a separate part, wherein during vibration welding, the edge of the first housing half shell forming surface portion of the oil pan is pressed onto the edge of the second housing half shell.

For a proper function of the engine, it is necessary that the Connection of the oil sump to the engine or transmission block and the connection of the items of a composite sump permanently tight. The oil pan is high temperature loads in the range of -40 to 160 ° C is exposed. Added to this are mechanical loads on the oil pan, for example when driving through potholes, driving on a curb, Rockfall or shutdown of the engine during servicing on the oil sump.

For Vibration welding becomes a relative one wide joining zone needed that the melted off Picking up material from the connection zone in catch margins, to prevent that during vibration welding The connection zone resulting abrasion contaminates the component. When vibration welding is the course of the joining zone on the components in the room due to the direction of vibration of the components relative to each other during the welding process and the Entformungsrichtung of the components specified and therefore not freely selectable.

The The object of the invention is a welding method for To develop plastic oil pans that do not pollute caused on the component and in which the course of the joining zone can be optimally adapted to the available space.

These The object is achieved by a manufacturing process for a sump made of thermoplastic material solved according to claim 1. The subclaims give appropriate training.

Disclosure of the invention

Of the Advantage of the method lies in that an oil pan with a complex geometry by the welding of individual parts by means of hot gas will be produced.

At the Hot gas welding of thermoplastics is a welding allowance to be welded to the Components on the outflowing hot gas plasticized without contact and then the components Pressed together under pressure and thus welded together. By joining ribs results in a jump in stiffness in the component wall, resulting in much higher forces can be absorbed by the component. The procedure is especially suitable for products with very high cleanliness requirements.

With the hot gas welding process, the course of the Joining zones in the room can be freely designed. Because in comparison for vibration welding in hot gas welding no fishing edge needed for the welding expulsion is, the joining zone can be made much narrower and narrower The available space for the oil pan be better used. In addition, can also be Contours outside the actual weld like narrow ribs or domes in the same welding process welding, as in hot gas welding a force is applied only in the joining direction and thus no oscillating lateral force acts on the components that resonate of component areas, result, such as in vibration welding.

With The claimed method can various items be welded together to form an oil pan, wherein the number of parts to be welded almost arbitrary can be chosen and is not limited to two. The Weld achieves high strength, so all occurring forces over the weld be transferred to the connected part. An immediate one Connection of the lower part with the internal combustion engine is not necessary.

It is possible in an alternative embodiment, Parts of the oil sump at an angle to the flange surface to weld the crankcase. It can different joining zones in different joining directions be implemented in an oil pan. So it is conceivable, lateral Weld cover to the sump.

Around to avoid leakage of the oil pan the welded joints between the oil pan inside and the environment be formed oil and airtight. The Welding of parts that are not the inside of the oil pan separate from the outside, such as reinforcing ribs, In contrast, interruptions or paragraphs in have the joining zone.

By the production of the oil pan by hot gas welding There is a great deal of freedom in the design of the individual parts. The installation space volume can be optimally utilized. It is possible, to arrange the bolting points of the sump so that a Part of the screw-on points on the connecting flange inside the oil sump lie down and out through the oil pan Domen are accessible from the outside. The seal takes place through the weld between the dome and the corresponding contour at the connecting flange. By arranged in the oil pan Dome is an expansion of the volume of the oil pan over the connection flange outwards possible.

By a shoulder in the inner diameter to support the fasteners the dome can be used to make the weld between the welded parts of the sump too relieve, since the fastener the paragraph in the cathedral with the Counter flange braced on the internal combustion engine.

When Material suitable for hot gas welding in particular thermoplastic such as polyamide or Polypropylene used to improve the strength or to optimize the surface texture with fillers as glass fibers or minerals can be enriched, being particularly advantageous plastics PA66 and PA6 are. Especially advantageous is a glass fiber content between 10% and 40%, in particular between 25% -35%.

The Sealing the plastic oil pan against the crankcase or the transmission housing of an internal combustion engine can done in different versions. The flange surface can with an inserted molded seal in the oil pan flange or take the corresponding counterflange, with a dosed Seal or with a flat gasket inserted between the components. A special form is the sealing of the oil pan over a radially acting seal between oil pan and counter flange, which has the advantage that over the connection of the oil pan to the internal combustion engine only the weight forces of oil sump and the oil contained therein, but not the power to Pressing a seal must be applied.

When Sealing materials are especially elastomers such as acrylate rubber (ACM), Ethylene-Acrylate-Rubber (AEM) or Flour-Rubber (FPM) suitable.

In an alternative embodiment may additional Functional components integrated in the plastic oil pan be, in particular components for preventing Ölschwall, Ölansaugleitungen or entire assemblies such as valves, oil filters or oil coolers. Part of the contour of these assemblies may be in the oil sump be formed so that only one more housing part the module must be attached. These functional components or groups can also with the hot gas welding or but also other welding or joining methods be attached.

About that In addition, can be in the geometry of the sump sockets for hoses, flanges for sensors or attachments or receptacles for oil drain plugs integrate.

Brief description of the drawings

1 shows a plastic oil pan, consisting of an annular upper part, welded to a trough-shaped lower part;

2 : shows an exploded view of the items 1 before welding;

3 : is a schematic diagram of the components in the region of the joining zone before welding ( 3A ) and after welding ( 3B ) with hot gas;

4 : shows a welded oil pan with additional attachments

Embodiment (s) of the invention

Of the 1 is an oil pan 1 refer to, which is composed of two plastic parts. A shell 2 has a connecting flange 4 to the crankcase of an internal combustion engine. For firm connection of the oil sump 1 with the mating flange on the crankcase are circumferentially on the connecting flange 4 mounting points 5 . 5 ' provided, for example, the screws ben or can receive threaded bolts to the oil pan 1 to screw with the internal combustion engine. To a deformation of the plastic in the area of the screw 5 To avoid metal bushes can be in the connecting flange 4 be introduced. The sealing of the oil sump 1 to the internal combustion engine, which can be done in a variety of skilled in the art types, is not shown.

All around the oil sump 1 runs the connection zone 6 at the top 2 and the lower part 3 welded together. This connection zone 6 between the housing halves takes place during operation of the internal combustion engine forces between the oil pan bottom 7 and the connecting flange 4 on.

To ensure safe operation of the internal combustion engine and to prevent oil leakage, is the connection zone 6 between the shell 2 and the lower part 3 oil and airtight designed between the inside and outside of the oil pan.

The lower part 3 the oil pan 1 is trough-shaped and forms part of the wall and the floor 7 the oil pan 1 , The lower part 3 indicates corresponding to the attachment points 5 ' at the top 2 Dome 11 on, which are hollow inside and over an opening 26 to the outside a mounting of the oil pan 1 on the internal combustion engine within the outer contour of the oil pan 1 allow by when mounting the oil pan 1 the fastener and optionally the assembly tool, for. B. a screw head through the dome 11 is guided and the oil pan 1 connects to the crankcase.

To strengthen the component structure and to stabilize the oil sump 1 against mechanical damage and to avoid disturbing vibrations of the housing wall are on the outside of the oil pan 1 ribs 8th attached, which is approximately at right angles to the wall of the oil pan 1 in the direction of the forces that occur. At least some of the ribs 8th extend from the connecting flange 4 at the top 2 to the oil pan bottom 7 at the bottom 3 , Ribs 8th be in one area 10 from the top 2 the oil pan 1 formed and in a subsequent area 9 from the lower part 3 the oil pan 1 educated. The upper area 10 is with the bottom area 9 welded. It is not necessary that the connection of the rib areas 9 . 10 in top part 2 and lower part 3 is welded oil or airtight. For example, breaks or paragraphs are to the connection zone 6 possible in the area of the connection of the ribs.

The 2 shows the items 2 . 3 the oil pan 1 before welding. The plastic parts are manufactured by injection molding. The wall thickness and the position of the reinforcing ribs 8th . 16 can be optimally adapted to the available space.

The top 2 the oil pan 1 is annular, wherein the contour of the wall predominantly the course of the connecting flange 4 follows. A number of screw-on points 5 at the connecting flange 4 is at a distance to the wall on the outside of the oil sump 1 arranged, more screw-on points 5 ' are at a distance to the wall on the inside of the oil sump 1 arranged. These screw-on points 5 ' are on the bottom of the connecting flange 4 with domes 11 from the lower part 3 connected by a corresponding inner diameter a screw connection of the oil pan 1 with the internal combustion engine through an opening 26 from the bottom of the oil pan 1 through the cathedral 11 enable. This dome 11 , formed by the lower part 3 are in the area of screw-on points 5 ' with a corresponding contour 12 in the upper part along a connection zone 13 welded. To avoid leakage of the oil pan 1 in the area of screw-on points 5 ' are these connection zones 13 oil and airtight formed. Like from the 2 It can be seen that the different connection zones 6 and 13 between the parts of the sump 1 at different distances relative to the connecting flange 4 lie and do not have to be connected. The hot-gas welding process allows any desired contours of thermoplastic parts to be welded. In contrast to vibration welding is also a curvature of the connection zone 6 possible in the room, as in the section 14 the connection zone 6 shown.

To improve the strength of the oil pan 1 are on the inside of the wall ribs 15 . 16 provided that like the ribs 8th on the outside in top part 2 and lower part 3 are formed and in a connection zone 17 are connected. As with the welding of the dome 11 with the corresponding contour 12 Also, the ribs on the outside or inside of the oil pan 1 in a connection zone 17 . 17 ' which is not consistent with the other connection zones.

As opposed to vibration welding during hot joining, there are no forces transverse to the joining direction on the construction during the joining process Part act, ribs and other elastic in at least one direction housing elements can be welded.

A representation of the connection zone 6 is the 3 refer to. The 3A shows the top 2 the oil pan 1 before welding to the base 3 as a cross section through the wall of the oil pan 1 in the area of a rib 8th , The connection zone 6 is designed so that the individual parts of the oil pan 1 Easy to produce by injection molding in a simple tool. The width of the connection zone is adapted depending on the load of the component in the respective area. So is the connection zone 6 in the area of the wall of the oil sump 1 slightly wider while at the ribs 8th the wall thickness in the area of the connection zone 17 . 17 ' not increased. For welding, in the joining direction on both parts to be joined a welding allowance 18 at the connection zone 6 provided during the welding of upper part 2 and lower part 3 is melted and plastically deformed.

The 3B shows the same components as 3A after welding with hot gas. Upper and lower part of the oil sump 1 are cohesively fused together and inseparably connected. In the area of the connection zone 6 The material melted with the hot gas is displaced transversely to the joining direction. In contrast to other mechanical welding processes, no abrasion forms, which can contaminate the component. The fused plastic material remains on the component in the form of a bead 19 adhere and form a firm and tight connection of the two components. This applies mutatis mutandis to the other described connections between the Domen 11 and the corresponding contour 12 as well as the ribs 15 and 16 on the inside of the oil pan 1 ,

Due to the design options of the plastic material, it is possible additional functions in the oil pan 1 to integrate. In the 4 some of these possibilities are shown. At the top 2 is a neck 20 molded for connecting a hose line, whereby it is also possible, nozzle or flanges for sensors to the lower part 3 to mold.

Additional component components made of plastic, such as a baffle plate 21 or intake pipes for oil or housing parts for oil filters, can also be by hot gas welding with the oil pan 1 connect. It is also possible to attach parts by means of plastic domes 22 to be fixed to the oil sump in the hot-riveting process.

For holding an oil drain plug 23 is in a housing part of the plastic oil pan 1 a screw thread or a bayonet closure molded. To accommodate smaller components are on the housing wall surveys or dome 24 . 24 ' provided on which the components can be screwed or locked.

For supporting a heavy component on the oil sump 1 , such as a transmission, is a gear support 25 at the oil pan 1 attached, with oil pan 1 and the gearbox support 25 the same screw-on points 5 . 5 ' use for attachment to the internal combustion engine.

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

• - EP 1264970 B1 [0003]
• - EP 0872632 A1 [0004]
• - EP 1416129 A1 [0005]

Claims (12)

Method for producing a plastic oil pan made of a thermoplastic, in particular for an internal combustion engine or a transmission, wherein the oil pan is welded together from several individual parts to joining zones, characterized in that the individual parts ( 2 . 3 ) of the oil pan ( 1 ) along the joining zones ( 6 . 13 . 17 . 17 ' ) are permanently connected by hot gas welding. A method according to claim 1, characterized in that the joining zones ( 6 . 13 . 17 . 17 ' ) are at least predominantly oil and airtight. Method according to claim 1 or 2, characterized in that the connected individual parts ( 2 . 3 ) consist of a polyamide. Method according to claim 3, characterized in that the connected individual parts ( 2 . 3 ) consist of glass fiber reinforced PA6 or glass fiber reinforced PA66. Method according to one of the preceding claims, characterized in that the individual parts ( 2 . 3 ) at least at a curved area extending in space ( 6 . 13 . 17 . 17 ' ) are interconnected. Method according to one of the preceding claims, characterized in that the oil sump ( 1 ) of several parts ( 2 . 3 ), which are connected to mutually independent joining zones ( 6 . 13 . 17 . 17 ' ) are connected. Method according to one of the preceding claims, characterized in that outside and / or inside of the housing wall of the oil pan ( 1 ) formed areas of the ribs ( 8th . 16 ) in the upper part ( 2 ) and lower part ( 3 ) are welded with. Method according to one of the preceding claims, characterized in that additional functional components ( 21 ) in the oil pan ( 1 ) are integrated. Method according to one of the preceding claims, characterized in that the oil sump ( 1 ) from an upper part ( 2 ) and a lower part ( 3 ), the upper part ( 2 ) annular with a connecting flange ( 4 ) with screw-on points ( 5 . 5 ' ) for attachment to the internal combustion engine and the lower part ( 3 ) are formed trough-shaped and both parts reinforcing ribs ( 8th . 16 ) inside and / or outside, wherein upper part ( 2 ) and lower part ( 3 ) by hot gas welding along a joining zone ( 6 ), Method according to claim 9, characterized in that the oil sump ( 1 ) at least one further joining zone ( 13 . 17 . 17 ' ) which is at a distance to the first joining zone ( 6 ) is arranged. A method according to claim 10, characterized in that the connecting flange ( 4 ) of the oil pan ( 1 ) Screw-on points ( 5 . 5 ' ), of which at least one within the outer contour of the oil pan ( 1 ) is arranged. Method according to claim 11, characterized in that the lower part ( 3 ) at least one dome ( 11 ) having a corresponding contour ( 12 ) on the connecting flange ( 4 ) at the top ( 2 ), through which the sump ( 1 ) can be attached to the internal combustion engine.