WO2005070646A1

WO2005070646A1 - Method for producing a throttle valve unit having increased tightness

Info

Publication number: WO2005070646A1
Application number: PCT/EP2004/052905
Authority: WO
Inventors: Johannes Meiwes
Original assignee: Robert Bosch Gmbh
Priority date: 2004-01-22
Filing date: 2004-11-10
Publication date: 2005-08-04
Also published as: DE102004003464A1

Abstract

The invention relates to a method for producing a throttle valve unit which comprises a housing part (10, 13, 53) and a valve part (17) that can be moved relative thereto. According to the invention, the housing part (10, 13, 53) is injection-molded in a first cavity from a first synthetic material. The preliminary injection-molded article (41) so obtained is transferred from the first cavity to a second cavity (42) which is spatially decoupled therefrom. A movable valve part (17) is injection-molded in the second cavity (42) from a second synthetic material (57) inside the preliminary injection-molded article (41), with the second injection-molding station (40) being cooled. A third material is then introduced into the gap geometries (61, 62) of the finished two-component injection-molded article (60). Before the third material is introduced, the gap geometries (61, 62) lie outside the tightness specification, and afterwards, after optional partial removal of the third material, within the required tightness specification.

Description

Process for producing a throttle valve unit with increased tightness

Technical field

In the automotive sector, throttle valve units are increasingly being mass-produced as plastic injection molded components. Such throttle valve units are, for example, valve housings produced by means of the injection molding process, together with valves that are injected into the housing. The throttle valve units used in the automotive sector are exposed to temperatures between minus 40 ° C and 120 ° C, so care must be taken to ensure that the functionality of the molded parts with regard to the gap widths achievable in the injection molding process is ensured in this temperature range ,

State of the art

EP 0 482 272 AI relates to a flap unit. A flap device and a driving method for producing a movable flap in a housing which accommodates the movable flap are disclosed. The valve and the valve housing are manufactured in one and the same tool. In a first injection molding step, the housing is manufactured and in a subsequent injection molding step the disc-shaped flap is molded into it. Sealing sections are formed on the flaps which are movable relative to the housing and cooperate in a sealing manner with housing regions of the flap housing. The flap is preferably one that is of a butterfly design and the flap housing is one that accommodates a butterfly-shaped flap. With the disclosed manufacturing method, a much more cost-effective production of a flap device for the motor vehicle area can be achieved. The position of the flap and its housing position are fixed to the transverse position to the air passage direction in this embodiment.

US 5,304,336 also relates to a ner method for manufacturing a device. This device contains a movable part and a housing for receiving the movable part. The moving part and the housing are manufactured by means of the injection molding process through sequential manufacturing steps. The housing is preferably injection molded in a first method step, while the part which is movable relative to the housing is manufactured in a further production step, the part being in a generally partially closed position. The disclosed manufacturing method ensures that a surface of the housing at least partially serves as a shape for forming a sealing section on the movable flap, so that a very close tolerance is achieved between the housing and the flap which can be moved relative to it. According to US Pat. No. 5,304,336, the flap, which is movable relative to the housing, is formed in a butterfly shape. The housing is preferably one that can accommodate a butterfly-shaped flap.

The manufacturing processes known from EP 0482272 A1 and US Pat. No. 5,304,336 for manufacturing an air guiding part by means of the injection molding process have the disadvantage that molded parts can be produced according to these processes, which may have inadequate functionality. This is essentially caused by inadequate adjustability and repeatability of the required gap widths in the shaft bearings and in the gas through-hole of devices manufactured in this way. The illustrated methods allow the gap width to be influenced in a targeted manner in order to achieve a defined amount of air in the closed position of the flap via machine setting parameters during shaping, i.e. insufficiently possible with the injection molding process. From one production cycle to the next production cycle, the gap widths required to achieve a defined amount of leakage air in the closed position of the flap cannot be reproduced to a sufficient extent.

The accuracy or uniformity of such gaps in flaps may only vary within a few μm. This is of considerable importance in the automotive sector, in which such air guiding parts are exposed to a larger temperature range, e.g. temperatures from - 40 ° C to + 120 ° C (engine operating temperature at the cylinder head area) by closely linking the temperature of the shaping tool and the cycle time of the Injection molding process according to the manufacturing process shown above, the required accuracy can not be achieved via the cavity provided in the molding tool. This applies in particular if, in the processes described according to the above solutions, partially crystalline or amorphous thermoplastic high-temperature plastics are used for applications in the engine compartment for the temperature range specified above. According to the production processes known from EP 0 482 272 AI and US Pat. No. 5,304,336, process fluctuations, such as, for example, fluctuations in the properties of the molding compositions during the shaping, ie during the production process by injection molding, driving, not reacting flexibly enough. The fluctuations described have an inadmissible impact on the quality of the devices obtained.

Presentation of the invention

According to the proposed method, the above-mentioned weaknesses of the methods known from the prior art are remedied, since the shaping of the molded parts, i.e. of a flap part and a housing part of a throttle device, not in a common cavity. The cavity within a two-component injection mold is divided into two separate cavities. The two cavities, which are separated from one another, can be accommodated in two separate molds by means of rotary plates or index plates or the like. The geometry of essential impression areas on the housing part during back injection through the flap part during the second injection stage can be used by changing the outer geometry of the bordering tool parts in the second cavity compared to the first cavity for the elastic deformation of the housing part (pre-molded part) in the second injection stage. This provides an additional possibility of influencing the gap which forms between the bearing points and the housing part and the edges of the flap part and the housing part. Partially crystal-free and amorphous high-temperature thermoplastics with high melting temperatures, possibly with high degrees of crystallization and high heat resistance as well as oil and fuel resistance, are injected into the two separate cavities according to the method proposed according to the invention. The semi-crystalline or amorphous high-temperature thermoplastics used have low coefficients of friction and low wear rates among themselves. The gap geometries of the prefabricated injection-molded part obtained by the two-component injection molding process, the housing part of which is made of a first plastic material and the flap part of which is made of a second plastic material, exist before the introduction of another, i.e. third material, outside of a tightness specification. After the third additional material has been introduced and, if necessary, after it has been partially removed, the resulting gap geometries are now within the tightness specification again.

As a third material, powdery solid parts or pasty processed materials are introduced into an injection molded part to increase the gap tightness and can be partially or completely removed from it later on. The injection molded part removed from the injection mold has a relatively large gap width. The third material mentioned can either be introduced as an additive onto the throttle valve or onto the inner wall of the throttle valve connector or directly into the gap between the throttle valve and the inner wall of the throttle valve connector. The additive seals the gap between the throttle flap and the throttle valve neck largely, but is so flexible or is sheared off when the throttle valve is moved for the first time in such a way that a small gap is created, but no jamming between the throttle valve and the throttle valve neck must be feared. This makes it possible to choose the permissible gap width during the injection molding process in such a way that the largest possible gap width takes into account the tolerances that can never be completely avoided. This allows the gap width S to spread quite strongly before the additive is applied, which considerably facilitates injection molding, since the gap width S obtained is defined by introducing or applying the third material after the injection molding and is not directly introduced during the injection molding process needs to be. This also allows the use of such injection-molded parts, the gap width S of which is to be counted with regard to the tolerance with regard to the tolerance without adding an additive between the edge of the throttle valve and the inner wall of the throttle valve injection molding.

By using the solution proposed according to the invention, the disadvantage inherent in the manufacturing process of clamping the flap in the housing is avoided. The shrinkage in and after the plastic injection molding process is set in such a way that the tightness lies outside the tightness specification customary on the market and by subsequent introduction of a third substance, i.e. of the additional material in the sealing gap is changed in such a way that the tightness again meets common tightness specifications. In particular, the shrinkage in the second injection molding step, i.e. for the throttle valve, chosen relatively large. This is achieved in that the mold temperature is kept low and the plastic melt can cool down accordingly. Furthermore, by enriching the second plastic material used in the second injection molding process with fillers, a small fiber part can be set in the plastic material. In particular, the proportion of granular, non-fibrous fillers in the second plastic material is chosen to be relatively large for the second injection molding step. Especially, the plastic injection molded parts obtained can be annealed after the plastic injection molding process before the third material, i.e. the additive is introduced. The third material can be a solid lubricant.

The plastic injection molding components or the housing blank can be tempered after the first injection molding process or after the second injection molding process, but in any case before the third material is introduced into the injection molding component.

drawing

The invention is described in more detail below with reference to the drawing. It shows:

FIG. 1 shows the frequency distribution of the number of gaps in the case of the previous manufacture of throttle bar devices,

FIG. 2, curve 1, the frequency distribution of the number of pieces / gap width during production in accordance with the procedure according to the invention before application of an additive,

Curve 2 shows the frequency distribution of the number of pieces / gap width during production according to the solutions according to the invention after application of the additive,

3 shows a pre-molded part inserted into a second injection station and a second cavity for injecting a second plastic material,

FIGS. 4 and 5 the flap parts injected into the pre-molded part of the housing part from a second plastic material within the second cavity, the flap parts of which are shown in FIG. 4 with an insert sleeve / slide bush and whose flap parts according to FIG. 5 are directly molded into the pre-molded part,

FIG. 6 application areas on the pre-molded part, on which, after the pre-molded part has been formed, lubricant or lubricant is applied or rubbed in a first spraying station or apphized in film form, and

FIG. 7 further possible application areas on the preform according to FIG. 6.

variants

The representation according to FIG. 1 shows the frequency distribution of the number of pieces / gap width when producing a throttle valve housing according to injection molding processes known from the prior art.

It can be seen from the illustration in FIG. 1 that with Si the minimum gap between the edge of the throttle valve, the inner wall of a throttle valve connector, forms the lower reject limit. If the gap width Si is undershot, the pivotably arranged throttle valve jams inside the throttle valve connector. Injection-molded parts that are less than the minimum gap width Si can therefore not be used and represent rejects that are expensive to produce. With S ₂ , the maximum gap width between the edge of a pivotable part in the throttle valve neck is accommodated. designated throttle valve and the inner wall of the throttle valve body. If the maximum gap width S _{2 is} exceeded, there is an excessively large gap between the edge of the pivotably arranged throttle valve and the wall of the throttle valve connector, through which a combustion chamber aspirates too much incorrect air, and consequently the proper functioning of the throttle folder device can no longer be guaranteed.

All injection molded components of the gap width that lie between the minimum gap width Si and the maximum permissible gap width S ₂ represent good parts that could be used on an internal combustion engine, be it in the intake or in the exhaust system.

The curve according to FIG. 2 shows curve 1 and curve 2. Curve 1 represents the number of pieces before the third material is introduced, ie. of the additive which determines the tightness before it is introduced. The number distribution according to curve 1 is plotted over the gap width. Curve 2 shows the distribution of the number of pieces after the introduction of the third material, i.e. of the additive determining the tightness. While curve 1 represents the number of pre-molded parts obtained, the gap width of which is predominantly greater than the maximum permissible gap S ₂ , curve 2 shows the number of pre-molded parts obtained, the gap width of which was chosen to be relatively large and S at most the gap width S ₂ is after the third material, ie the additive defining the tightness, has been introduced between the wall of the throttle valve assembly and the outer edge of the throttle valve. It can be seen from curve 2 that the number of pre-molded parts which represent good parts, ie which can be used further, could be increased significantly by using the method proposed according to the invention. Before the pre-molded parts to be counted as rejects, since the maximum gap width S ₂ exceeds the gap widths, the method proposed according to the invention can be used to convert the permissible tolerance measure, ie into the range between the minimum permissible gap Si and the maximum permissible gap S ₂ , so that overall a much higher productivity can be achieved by using the method proposed according to the invention in the manufacture of plastic components produced by the two-component injection molding method.

This is achieved in that the shrinkage, in particular in the second injection molding process step, ie when the valve is injected into the throttle valve housing, is selected to be large. This can be achieved by means of a cooled injection mold, which enables rapid cooling, ie solidification of the plastic melt. If fillers such as granular, non-fibrous materials are added to the second plastic material used in the second injection molding step, the shrinkage process is further enhanced by this process parameter. The third material, ie the additive that defines the tightness, can be a solid lubricant such as molybdenum disulphide. fid (trade name: Molykote) or other molybdenum compounds or graphite.

FIG. 3 shows a pre-molded part inserted into a second injection station and a second cavity for injecting a second plastic material from which the throttle valve is manufactured.

Before a pre-molded part 41 is inserted into a second injection station 40, an intermediate treatment of the pre-molded part 41 between the first injection stage, i.e. after demolding from the first molding station and before inserting the preform 41 into the second injection station 40 shown in FIG. This can be, for example, an annealing process, but this is not absolutely necessary. After the demolding of a housing part 10, 41 from the first cavity, i.e. after completion of the first injection stage, the pre-molded part 41 is fed directly to a thermal intermediate treatment above the glass transition temperature of the first plastic material. This can e.g. done within a heating cabinet. At the temperature level at which the intermediate treatment is carried out, induced stresses occurring in the thermoplastics during injection molding subside. This applies to both semi-crystalline thermoplastics and amorphous high-temperature thermoplastics. After a few minutes of residence of the preform 41 in the intermediate treatment, the molecular orientations during the filling process of the first cavity or the rapid cooling of the preform 41 due to delayed crystallization effects reduce the stresses and shrinkage effects in the thermoplastics to a negligible level.

Without carrying out an intermediate treatment, the stresses induced by molecular orientations or by rapid cooling of the preform 41 by delayed crystallization effects in partially crystalline thermoplastics would reside in the preform 41 during its entire operating time. Because of the thermal intermediate treatment, it is avoided that the induced voltages lead to a re-deformation of the pre-molded part 41, which may persist over a longer operating time of the throttle valve unit, and thus to a change in the gap geometries. The change in the gap geometries due to back-deformation of the housing 10, i.e. of the preform 41 without thermal intermediate treatment, in extreme cases lead to the possible setting of one relative to the preform 41, i. to the housing part 10 movable flap part 17th

The pre-molded part shown in FIG. 4 comprises the housing part 10 of a throttle valve unit for carrying out the second injection stage, within the second injection station 40 the pre-molded part 41 is removed from the first cavity of the first injection station. After the injection molding of the preform 41 from a first plastic material, the preform 41 can be fed to the second injection station 40 in an injection molding device by manual repositioning, by actuating a turntable transporting the preform 41, an index plate or a handling system. A second cavity 42 is provided in the second injection station 40 to form the flap part 17 to be integrated into the pre-molded part 41. The geometry of essential impression areas on the pre-molded part 41 during the back injection of the flap part 17 in the second injection station 40 can be changed by changing the outer geometry of the bordering tool parts of the second cavity 42 compared to the first cavity for elastic deformation or prestressing of the pre-molded part 41 in the context of the second Injection stage within the second spray station 40 can be used. This enables a tool-related influencing of a later gap formation between the sealing edge of the flap part 17 and the bearing points in the pre-molded part 41.

When using the proposed method, the sealing edge of the flap part 17 can be designed in such a way that the flap part 17 passes through the gas passage opening 13 without contact in the prefabricated injection molding part. The sealing edge on the flap part 17 is to be regarded as sealing when a flap part 17 is designed so as to be leak-tight, if at the gap between the flap part 17 and the wall of the gas passage opening 13 air mass flow of 2 kg / h to 6 kg / h is permitted, whichever according to the diameter of the gas passage opening 13 in the pre-injected housing part 10 is to be regarded as “tight” in the sense of the tightness specification. Alternatively, the flap part 17, which is preferably injected with a curved flap surface into the pre-injected housing part 10, can also be formed as a non-penetrating flap part 17, which inside the gas passage opening 13 usually reaches its largely sealing position in an inclined position between 8 ° and 10 °, based on a vertical 90 ° position of the flap part 17 in the gas passage opening 13. Even in the case of non-penetrating flap parts 17, the “sealing tax” ng "of the hinged flap part 17 in the pre-injected housing part 10 between the sealing edge and the inner wall of the gas passage opening 13, an air mass flow in the order of magnitude between 2 kg / h and 6 kg / h is permitted. Such a non-submerged throttle valve is to be regarded as “tight” in the sense of the tightness specification. Depending on the diameter dimension of the gas passage opening 13 in the pre-injected housing part 10, air mass flows higher than the above-mentioned 2 kg / h to 6 kg / h can also be achieved are permitted, whereby the throttle valve unit is still to be regarded as “tight” in the sense of the tightness specification even in the case of the higher air mass flows that pass through the sealing edge. The second injection station 40 as shown in FIG. 4 contains the second cavity 42, which is defined by the mutually opposite end faces of a first mold insert 43 or a second mold insert 44. A contouring 47 is formed on the side of the first mold insert 43 which delimits the second cavity 42; Furthermore, the gate 24 is on the side of the first mold insert 43 facing the second cavity 42. FIG. 4 shows that the contouring 47 of the first mold insert 43 forms a rib on one side of the flap surface. The ribbing and the contour of the flap surface are designed in accordance with the mechanical and fluidic requirements for the throttle valve unit to be manufactured. In addition to a curved flap surface of the flap part 17, this can also be made flat.

The second cavity 42 is also delimited by a first core part 45 or a second core part 46. The second plastic material injected into the second cavity 42 flows around the mutually opposite tips of the core parts 45 and 46. As a result, cavities of the first valve shaft part 19 and of the second valve part 20 are formed in the second cavity 42. The core parts 45 and 46 are enclosed within the second injection station 40 by sleeves 48, which can be designed to be pullable in the horizontal direction as well as in the vertical direction. To vary the geometry, a spacer ring 49 is embedded below the first mold insert 43.

FIGS. 4 and 5 each show the second cavity, which is completely filled with the second plastic material, an insert sleeve being introduced into the pre-molded part in the embodiment variant according to FIG. 4, while in the embodiment variant shown in FIG. 5 the valve body is directly in the wall the pre-molded part is injected.

Via the injection point 24 in the first mold insert 43, the second plastic material 57 is injected into the second cavity 42, which is no longer present in FIGS. 4 and 5 and, in the illustrated state, is already completely filled with the second plastic material 57. According to the contouring of the two mold inserts 43 and 44 delimiting the second cavity, a flap part 17 is molded into the pre-molded part 41. Flap parts 19 and 20 formed from the second plastic material 57 are molded onto this. Due to the movable core parts 45 and 46 formed on the second injection station 40, cavities are formed in the valve parts 19, 20 in order to avoid accumulation of material.

The KlappenweUenteile 19 and 20 penetrate the inner wall of the pre-molded part 41, which is the housing part 10. The inner wall of the preform 41 is covered with Zugszeichen 53 marked, the outer wall with reference numeral 54. Corresponding to the shape of the second cavity 42 now filled by the second plastic material 57 are on the KlappenweUenteile 19 and 20 opposing each other, the wall of the pre-molded part 41, creating sealing surfaces. Adhering to the first sealing surface 55 in the axial direction, sliding bushings 52 (see illustration according to FIG. 4) can be inserted or pressed into the openings 14 for the valve parts in the pre-molded part 41 on the valve parts 19 and 20 before the second injection stage , When the second plastic material 57 is injected, these are filled in by the second plastic material 57 via the injection point 24 and are therefore accommodated precisely on the first flap shaft part 19 or the second flap valve part 20. The slide bush designated by reference numeral 52 is made of a material with properties that reduce friction and wear in the axial length of the respective valve body part 19, 20. According to the illustration in FIG. 5, the flap part 20 is injected directly into the wall of the pre-molded part 41, without an interposition, as in FIG. This applies analogously to the first KlappenweUenteü 19.

However, it is equally possible to provide the valve valve 20, which is shown in FIG. 5 on the drive side of the valve unit 17, which is shown here without slide bushing 52 or 19, with a corresponding slide bushing 52. 4 shows the KlappenweUenteü 19, which is provided with a sliding bush 52. The representations according to FIGS. 7 and 8 show application areas on the prefabricated building received, i.e. on the pre-molded part of a throttle valve unit, after which a lubricant / lubricant can be applied, rubbed in or foamed out after removal from the tool.

After the optional thermal intermediate treatment of the preform 41, after its manufacture within a first injection station and before the insertion of the preform 41 into the second injection station 40, impression surfaces 63 or 64 for the second plastic material, which is subsequently placed in a mold by the preform 41 limited second cavity 42 is injected, a material is applied so that the first plastic material of the preform 41 does not directly with the second plastic material 57, from which the flap part 17 together with flap valve parts 19 and 20 are made in the second injection station 40 Touch comes. Thus, using the method proposed according to the invention with cavities separated from one another, plastic materials that would otherwise adhere to one another can also be used. This also allows identical first and second plastic materials to be used to manufacture a throttle valve unit.

By introducing a third material after the second injection molding process onto impression surfaces 63 or 64, ie between the sealing edge of the flap door 17 and the inner wall 53 of the gas passage opening 13, any play that may be present there, ie a gap width S that lies above the maximum tolerable gap width S _2, is compensated for. This measure can be used to make a pre-molded part 41, which is possibly to be counted as rejects, into a Gutteü, which can be used for further use. By injecting the third material after the second injection molding process, which can be a pasty or also a solid material, such as a molybdenum compound or graphite, the gap width is reduced, so that the tightness of the flap part 17 with respect to the gas passage opening 13 after the introduction of the third material after the second injection molding process again within the required tightness specification depending on the diameter of the gas passage opening 13. According to a particularly advantageous aspect of the method proposed according to the invention, a larger gap width between the sealing edge of the flap part 17 and the inner wall 53 of the gas passage opening 13 can be achieved in that the injection molding tool, ie the second injection station 40 in the present case, during or after the injection / injection Injection of the second plastic material 57 is cooled and a low mold temperature is maintained. This favors the shrinkage of the second plastic material 57 and enables the melt of the second plastic material 57 to cool down very quickly in the second injection station 40. On the other hand, the shrinkage behavior can be positively influenced, ie the setting of a relatively large gap width is possible by adding fillers to the second plastic material become. By adding fillers to the second plastic material 57, its fiber content is reduced and a larger proportion of granular materials is achieved, which in turn has a positive influence on the shrinkage behavior of a second plastic material 57 composed in this way.

7 shows that the third material can be applied to the second impression surfaces 64 after the second injection molding process, which are formed by the inside of the openings 14 in the wall of the pre-molded part 41 for receiving the valve shaft parts 19 and 20. The application of the further third material after the second injection molding process, which determines the tightness of the preform 41 in the region of the openings 14, can be carried out by applying, rubbing in or lining with a foamed material. In the illustration according to FIG. 7, the pre-molded part can be coated with the further, third material after the second injection molding process after removal from the second injection station in the region of the inner sides of the openings 14.

The third material, ie the additive defining the tightness between the sealing edge of the flap part 17 and the inner wall 53 of the gas passage opening 13, can be flexible or can be sheared off in the housing part 10 during the first movement of the flap part 17 relative to the gas passage opening 13. This creates a smaller gap width S, a jamming between the flap 17 and the gas passage opening 13 is excluded. This makes it very easy to ensure that the gap width S in all the throttle valve bodies manufactured lies within the tolerances Si minimum gap and S ₂ maximum gap shown in FIG. 2, compare curve 2 there. As a result, the scattering of the gap width obtained with injection lengths 41, which are produced by means of the two-component injection molding method, can be achieved, which considerably simplifies the injection molding process.

LIST OF REFERENCE NUMBERS

Enclosure gas opening for flap valve Injection points for introducing the first plastic material

flap member

first valve shaft second valve shaft

flow direction

Injection point for second plastic material

second injection station pre-molding second cavity for flap part 17 first mold insert second mold insert first core part (horizontally pullable) second core part (horizontally pullable) contouring first mold insert 43 sleeve for core parts (horizontally or vertically pullable) spacer ring

Gleifbuchse inner wall pre-molded part 41 outer wall pre-molded part 41 sealing surface second plastic material

Two-component injection molded part from a second injection station 40 Flap gap, gas passage opening, gap valve flap bearing, first contact surface for third material second application area for third material

first sliding bush second sliding bush

Claims

claims

1. A method for producing a throttle folder unit, comprising a housing part (10, 13, 53) and a flap part (17) movable relative to the latter, with the following method steps: a) the injection molding of the housing part (10, 13, 53) in a first cavity from a first plastic material, b) the transfer of the pre-molded part (41) of the housing part (10, 13, 53) obtained according to method step a) into a second cavity (42) spatially separated from the first cavity, c) the injection molding of the movable flap part ( 17) made of a second plastic material (57) inside the pre-molded part (41) of the housing part (10, 13, 53) in the second cavity (42), which is cooled during the injection molding of the second plastic material 57 and d) introducing a third material after the injection molding of the second plastic material (57), into the gap geometries (61, 62) of a two-component injection molded part (60) obtained, the gap geometries (61, 62) before the introduction of the third material outside the tightness specification and after the introduction of the third material, if necessary, partial removal of the third material within the tightness specification.

2. The method according spoke 1, characterized in that between the transfer according to step a) obtained preform (41) of the housing part (10, 13, 53) from the first cavity into the spatially separated second cavity (42) a thermal intermediate treatment of Injection molding (41) takes place.

3. The method according to claim 2, characterized in that the thermal intermediate treatment is carried out by an annealing process.

Method according to spoke 1, characterized in that the third material introduced into the gap geometries (61, 62) of the two-component pre-molded part (60) according to method step d) is a solid lubricant.

5. The method according to claim 1, characterized in that the second plastic material (57) is mixed with a small fibrous Anteü and a large granular fraction.

6. The method according spoke 4, characterized in that molybdenum compounds or graphite are introduced as the solid lubricant.

7. The method according spoke 6, characterized in that molybdenum disulfide is introduced as the third material.

8. The method according spoke 1, characterized in that the third material is introduced after the second injection molding process in step c).

9. The method according spoke 1, characterized in that after the injection molding of the housing part (10, 13, 53) according to method step a) and before the injection molding of the movable flap part (17) from the second plastic material (57) inside the pre-molded part ( 41) bushings for the movable flap (17) are introduced into the pre-molded part (41).