DE10105526A1 - Device for controlling a gas flow and manufacturing method thereof - Google Patents

Abstract

The invention relates to a method for producing a valve assembly (4) for controlling a gaseous stream (24), e.g. in an internal combustion engine. According to said method, seat surfaces (28) in the end regions of a shaft (3) are provided with bearing bodies (9). This pre-assembled subassembly is introduced into an injection-moulding mould. The pre-assembled subassembly, together with the shaft (3) and the bearing bodies (9) located thereon, is encapsulated by injection moulding in a conventional injection moulding process, to simultaneously form a valve surface (11) and a housing (1, 10) that surrounds said surface and the bearing bodies (9).

Description

Technical field

On internal combustion engines, be it direct injection internal combustion engines NEN or on gasoline injection internal combustion engines is a control of too supply and discharge gas flows required. For example, a Throttle valve controls the intake air volume, the valve system also controls Exhaust gas flow controlled. A control of the exhaust gas volume flow is particularly in Ab gas recirculation systems necessary, in which part of the exhaust gas flow is the intake air flow is added again. The control of supply air or exhaust gas flows to combustion Engines are usually made using valve systems, the valves in which the Pipe systems conducting gas flows can be inclined. The manufacturing costs sol Valve systems are not insignificant.

State of the art

DE 30 39 868 A1 relates to a vibration damper and a method for its Production. These are produced by an injection molding process, with In Inner part and outer part of the vibration damper made of a rigid or rigid thermoplastic material such as polystyrene. Then there is a springy intermediate piece of a thermoplastic elastomer, for example a copolymer Butadiene and styrene molded and on the outer and inner parts in a following Injection molding stage manufactured.

DE 197 03 296 A1 relates to a method for sealing a throttle valve the throttle valve shaft and throttle body. With a throttle body for An internal combustion engine of a motor vehicle is a recess in the throttle valve Penetrant penetrating throttle valve shaft sealed with a hardening sealant.  The sealant prevents air from flowing through a manufacturing conditional gap between the throttle valve shaft and the recesses.

EP 0 575 235 B1 relates to a rotatable throttle element for fuel injection plant of internal combustion engines. A shaft with cylindrical seats is provided, which receives a section for receiving a throttle valve, the section has a constant, non-rotationally symmetrical cross-section that is larger than that Cross section of the part of the shaft located on one side of the section. The Dros selflap has a central bore, the cross section of which corresponds to that of the section speaks. The shaft is made entirely of plastic and is in one piece with a cam to hang or wind up a ge on the other side of said section cast control cable, the throttle valve itself be made of filled plastic stands. The plastic is preferably a thermoplastic. The section of the Throttle valve shaft has a cylindrical shape with parallel flats; the throttle flap in turn has a flattened hub with a central bore, the cross section has the shape of a circle flattened parallel to the wings of the throttle valve.

DE 42 24 171 A1 relates to an injection molded part as well as a method and an injection casting tool for producing the injection molded part. Using the proposed method can be injection molded parts that have at least two colors and / or at least two have different plastics and in at least two consecutive pro steps in which the colors and / or the plastics are successively injected into an injection mold tool are injected, are manufactured. After the injection process step The injection molded part remains in the first color and / or the first plastic in the closed mold, after which he adjoins a cavity testifies or released and in this the second color and / or the second plastic is injected. For this purpose, the injection mold has at least one slide, which the modified cavity in the mold for the injection molded part. By this Vorge hensweise can be achieved that the injection mold between the two spray pouring processes can remain closed and thus the surfaces of the pre-sprayed Parts cannot come into contact with the ambient air.

Conventional throttle valve systems usually include a housing, the throttle flap, the throttle valve shaft, bearing body and a number of fastening and Sealing elements. Before these components are assembled, a number are in part lengthy processing steps as well as calibration steps, such as opening drilling of bearing seats, grinding the throttle valve shaft as well as a precise drilling or otherwise machining the throttle valve bore in the housing. Although today  plastics are increasingly being used to manufacture throttle valve systems, stir manufacturing inaccuracies from the fasteners and in relative to each other of the movable surfaces, whose accuracy of fit only follow in different ways the processing steps are achieved.

Presentation of the invention

With the method proposed according to the invention, a gas stream can be Manufacture controlling flap system with a minimum of further assembly steps. Further are formed after forming a pivotable in a housing, one Throttle valve controlling gas flow no further, the surface quality of the fit manufactured component-improving processing steps required. The fold system-forming components are made according to the one-component injection molding process manufactured inexpensively, which means that final assembly of individual components such as Klap penwelle, throttle valve can be completely eliminated within the housing. To the ferti Accuracy of the throttle valve shaft are only increased requirements in the loading to provide rich seating surfaces for the bearing body; it can be one with tolerances afflicted throttle valve shaft are used, to which the throttle valve is directly attached is injected and manufacturing accuracy required joining operations between flap and Shaft can be completely eliminated. In particular, the throttle valve is now on receiving shaft no longer requires a slot to insert the throttle valve.

A particularly tight flap system that allows the lowest leakage flows can be achieved if, before the injection of the plastic into the mold, the on the En the bearing body provided for the throttle valve shaft is contaminated with a lubricant overmolded with plastic. With regard to their dimensions, the bearing bodies can be designed with higher degrees of freedom, which allows greater design variability. The flap system, manufactured according to the manufacturer proposed according to the invention driving, can be carried out almost without play. You can also use this for other areas of application than the use of internal combustion engines for motor vehicles ge required drive elements such as curves, gears or the like during the Injection molding in one-component injection molding process without any problems. By waiving the flap arrangement made according to the invention can be attached to metallic fastening elements low weight. It can also be made non-cylindrical Inject the throttle flaps formed in the housing, which is done with conventional assembly would be associated with considerable joining problems.  

The plastic used in accordance with the one-component injection molding process can, depending on the one Purpose of the flap arrangement to be produced according to the intended purpose lying temperatures can be selected. This is how pure supply air flaps can be removed produce cheaper plastics; Valve systems with higher thermal loads can NEN are made from correspondingly more temperature-resistant plastics.

drawing

The invention is explained in detail below with reference to the drawing.

It shows:

Fig. 1 is a plan view of a located in the open position, flap assembly in the surrounding housing,

Fig. 2 is a sectional view of the door assembly shown in Fig. 1,

Fig. 2.1 shows a detail of the door assembly shown in FIG. 2,

Fig. 3 shows a cross section through the located in the open position, flap arrangement according to FIG. 1,

Fig. 3.1, the illustration of the bevel of the circumferential surface of the flap assembly,

Fig. 4 is a top perspective view of a gas flow controlling Klappenanord voltage according to Fig. 1,

Fig. 5 is a plan view of the flap surrounding the housing,

Fig. 6 is a section through the flap receiving, on both sides in the molded housing journal rotatably mounted shaft,

Fig. 6.1 is an enlarged view of the overlapped region of the flap shaft.

variants

From the illustration of FIG. 1 is a plan view is more apparent on a surface in the open position befindli flap assembly in the surrounding housing.

A valve 4 used to control a gas flow is taken on a valve shaft 3 . The flap shaft 3 is formed symmetrically to the center line 5 and stored at approximately 7 locations in molded on the housing 1 pin 10 . A number of fasteners are formed on the outside of the housing 1 . The on the free Strö flow cross-section 2 received flap 4 is pivoted into its maximum open position, so that, as shown in FIG. 1, the largest possible flow cross-section 2 is released. In the plan view according to FIG. 1, the flap 4 is provided with ribbing 6 on both sides, which improves the mechanical strength of the flap surface of the flap 4 . The ribbing 6 can also be accommodated on only one side of the flap 4, in a departure from the illustration according to FIG. 1. The shaft 3 , on which the flap 4 - shown in its maximum open position - is injected, is rotatably mounted in bearing bodies (not shown here) in the injection pins 10 on the housing 1 .

From the view in Fig. 2 is a sectional view of the door assembly shown in Fig. 1 shows.

From the sectional view of FIG. 2 of the valve assembly of FIG. 1 it can be removed that the shaft 3 is provided with bearing bodies 9 at its end regions. The La gerkkörper 9 are preferably made of a material impregnated with a lubricant such as oil, for example sintered bronze. Instead of bearing bodies made of sintered bronze, bearing bodies 9 made of steel can also be used.

On the shaft 3 , which may well be subject to tolerances, the bearing body 9 are applied in the Endbe range. The assembly which has been preassembled in this way is placed in an injection mold, which is then closed, so that the housing 1, including the molded-on pins 10 formed thereon, and the flap surface 11 of the flap 4 can be formed in one step in accordance with the one-component injection molding process in the injection mold. During the injection molding process, the flap surface 11 is generated, which is thereby directly connected to the tolerance-sensitive area of the shaft 3 . This procedure only requires machining the shaft 3 in the areas which serve as seat surfaces 28 for the bearing body 9 . During the insert molding of the bearing body from 9 and shaft 3 formed vormon oriented assembly in the injection mold encloses the injected plastic in the loading area of the storage locations 7, the bearing body. 9 To fix the bearing body 9 in the injection pin 10 of the housing 1 , individual or umlau fende projections 13 can be formed on the injection pin 10, which engage in corresponding individual or umlau fende recesses on the bearing bodies 9 . This avoids twisting such as an axial displacement and thus potential leakage between the injection pin 10 and the bearing body 9 . Supported by the lubricant, which is preferably applied to the bearing body 9 during its assembly on the shaft 3 , the sealing effect between the gudgeon pin 10 and the bearing body 9 is additionally increased. Due to the projections 13 formed during molding, which engage in individual recesses or annular circumferential recesses 14 of the bearing body 9 , a relative movement of the bearing body 9 in the injection pin 10 is avoided. Furthermore, the positive connection between the outside of the bearing body 9 and the inside of the injection pin 10 prevents axial movement of the molded valve surface 11 receiving shaft 3 . The shaft 3 is only able to rotate relative to the bearing bodies 9 arranged in a rotationally fixed manner in the injection pins 10.

In a preferred embodiment of the method proposed according to the invention, the flap surface 11 is oriented with respect to the flow cross section 2 within the housing 1 so that it assumes an open position. Particularly good results when the flap surface 11 was sprayed onto the shaft 3 passing through the flow cross section 2 were obtained when the flap surface 11 was in its maximum open position during the molding of the shaft 3 .

With reference numeral 15 is shown in FIG 2. A contact surface designated, which rule is Zvi the flap surface 11 and projects into the flow cross-section 2 FLAE surfaces of the bearing body 9 is established.

From the view in Fig. 2 is a detail of the valve assembly 2 is shown in FIG. More apparent.

The reproduced in an enlarged scale Fig. 2.1 can be seen that a positive connection has been established between the outside of the bearing body 9 located on the shaft 3 and the inside of the injection pin 10. This positive connection between injection gudgeon 10 and bearing body 9, which occurs during the encapsulation of the bearing body 9, represents a sealing element in addition to a bearing point of the shaft 3. Depending on the number of projections 13 formed on the injection gudgeon 10 and the number of corresponding recesses 14 on the peripheral surface of the bearing body 9 is a gap seal, which ends on the side of the bearing body 9 facing the flap surface 11 and ends in a sealing surface 16 . Supported by the contact surface 15 between the flap surface 11 and the end face of the bearing body 9 , the flap arrangement according to the invention for controlling a gas flow is also secured on this side against escaping gaseous medium.

From the view in Fig. 2.1 also shows that for increasing the sealing effect of the bearing body 9 are formed adjacent to the flap surface 11, ie, the inner wall of the housing 1, 10 are formed by putting. By forming the first projection 13 on the injection pin 10 as close as possible to the inner wall of the housing 1 , 10 formed simultaneously with the flap surface 11 in the injection mold, a maximum sealing effect can be achieved directly on the injection pin 10.

From the view in Fig. 3 is a cross-section 1 passes through a located in its open position valve according to Fig. More apparent.

The flow cross section 2 of the housing 1 injected simultaneously with the flap surface 11 is flowed through by a gas stream, for example the supply air or the exhaust gas of an internal combustion engine. By rotating the flap 4 by actuating the flap shaft 3 , a reduction or enlargement of the flow cross section 2 takes place within the housing 1 . In the illustration according to FIG. 3, the Umfangsflä is surface 25 of the flap surface provided with a sealing bevel 20 11, wherein the inner half in Fig. 3 is asked flap 4 in a clockwise direction from its open position into a closed position of the flow cross-section 2 of the housing 1 is movable. During the Umsprit zens the valve shaft 3 in the injection mold, the contour of the sealing bevel 20 un ter different preselectable helix angles 22 on the peripheral surface 25 of the valve surface 11 can be generated. By forming a sealing bevel 20 on the peripheral surface 25 of the flap surface 11 , an improved sealing effect and the avoidance of incorrect air flows can be achieved, in particular in the closed state of the flap 4 in the housing 1 . From the view in Fig. 3 also shows that according to this exporting approximately example the flap 4 may be provided on both sides with a ribbing. 6 The ribbing 6 can also be provided only on one side of the flap 4 in order to improve the mechanical properties of the flap arrangement.

From the representation according to FIG. 3.1, the representation of the slope on the peripheral surface of the flap arrangement is apparent. Depending on the injection mold used, the peripheral surface 25 of the flap surface 11 of the flap 4 can be designed with different sealing slopes. In order to keep the actuating forces of the flap 4 around the shaft 3 small, care must be taken that the helix angle 22 on the sealing slope 20 with respect to the inner wall 17 of the housing 1 is optimal in terms of the sealing effect and in terms of minimizing the torque to be used will hold. The helix angle 22 of the sealing bevel 20 is preferably in the range between 0 and 15 °. The sealing bevel 20 can already be formed during the encapsulation of the flap shaft 3 when the flap surface 11 of the flap 4 is formed, so that further machining steps which increase the accuracy of fit are unnecessary. If the sealing bevel 20 is provided with a tip 21 on its rear part, as seen in the direction of rotation, even after prolonged operation of the throttle valve arrangement produced according to the invention, satisfactory results can be achieved with regard to the leakage currents that occur.

From the view in Fig. 4 is a perspective rendering shows a gas flow controlling valve arrangement.

As is already known from the representation according to FIG. 1, a number of fastenings 8 are provided on the outer wall of the housing 1 with injection pegs 10, with which the invention is produced in one operation, only requiring a pre-assembly of the shaft 3 and bearing body 9 , one Component representing flap arrangement can be integrated into a supply air or exhaust system on an internal combustion engine. The shaft journals of the shaft 3 are designated by reference numeral 23 , on which the drive for pivoting the flap 4 into the shaft 3 can be introduced. This he preferably follows via an actuator, with which the flap 4 within the flow cross-section 2 is adjustable in any rotational position. In its closed position, the peripheral surface 25 is provided with a sealing bevel 20 as shown in FIG. 3.1 on the Innenwan extension 17 of the housing 1 and prevents the flow through the free cross section 2 by a gas stream, be it supply air or exhaust gas from an internal combustion engine. The one-step training of housing 1 with Spritzzap fen 10 and the flap surface 11 of the flap 4 leads in particular to an embodiment of a flap arrangement with minimal play, ie a minimization of leakage flows between these component components. Depending on the thermal stress conditions during operation on an internal combustion engine or other machines that produce or require a gas-shaped medium, the wall thickness 26 on the housing 1 can be adjusted during the injection molding process.

In order to remove burrs from plastic residues between the relatively movable components shaft 3 with flap surface 11 and inner wall 17 of the housing 1 during the one-component injection molding process, these can be moved back and forth by briefly moving the flap surface 11 by rotating the shaft 3 in the injection pin 10 are removed. A further post-processing of the flap arrangement generated in one operation according to the one-component injection molding process is not necessary. To improve the flow behavior of the gas flow through the flow cross-section 2 of the valve arrangement proposed according to the invention, the ribbing patterns 6 and 31 in the area of the valve surface 11 can also be provided with other geometry, for example for generating a swirl. The design of the geometry of the ribs 6 and 31 in the area of the flap surface 11 is based on the intended use of the flap arrangement produced according to the invention.

From the view in Fig. 5 is a top view shows the flaps order to imaging housing closer to the. The one-piece housing 1 , 10 , which comprises the bearing body 9 of the shaft 3 receiving injection pin 10, is provided with individual fastening conditions 8 . With regard to the parting line of the injection mold, which coincides with the center line 5 , the fastenings 8 have a slightly trapezoidal contour on their outer surfaces. Favored by this, the flap assembly produced in one operation can be removed more easily from the injection mold.

From the view in Fig. 6 is a section shows by which the flap 4 receiving, on both sides rotatably supported in molded housing pin 10 shaft 3. With Be 28 , the seats for the bearing body 9 in the region of the bearing pin 23 of the shaft 3 are designated. Only in the area of the seat 28 is the body 3 to be equipped with the bearing shaft 3 to edit on its surface. Since the flap surface 11 of the flap 4 is molded onto the shaft 3 within the free flow cross-section 2 , there is no need for complex machining of the shaft 3 in the section of the shaft 3 lying between the bearing bodies 9 , since joining operations are completely unnecessary. The attachments 8 provided on their outer sides with slightly beveled contours for easier demolding of the workpiece produced in one operation are distributed symmetrically on the outer circumference 27 of the housing 1 with injection pins 10. Instead of the ge shown here, arranged at 90 ° to each other fasteners 8 , depending on the size and flow cross-section 2 of the housing 1 with injection spigot 10 also several, for example at 60 ° offset from each other fastenings 8 on the outer wall 27 of the housing 1 , 10 , This depends on the dimensions and the stress on the housing 1 , 10 . The pins 23 of the shaft 3 projecting beyond the injection pins 10 of the housing 1 can be provided with curves or plastic drive elements in the same work step, so that no separate work steps are required to equip them with these drive or control elements. Reference numbers 13 and 14 denote the positive connections in the area of the injection pins 10, which prevent relative movement of the bearing bodies 9 with respect to the injection pins 10. A rotational movement of the shaft 3 is only possible with respect to the bearing body 9 .

From the view in Fig. 6 6.1 is an enlarged reproduction of rich Lagerungsbe the flap shaft according to FIG. More apparent. The reproduction of the storage area according to FIG. 6.1 essentially corresponds to the storage shown in FIG. 2.1, but rotated by 90 °. According to the illustration in FIG. 6.1, a sealing surface 16 is formed between the injection peg 10 and the outer surface 30 of the bearing body 9 . On the sealing surface 16 in the axial direction of the bearing body 9 , then seen projections 13 formed on the injection pin 10 with corresponding recesses 14 on the outside 30 of the bearing body 9 form a positive connection. Depending on the number of formed in the axial direction between the bearing body 9 and injection pin 10 th positive connections 13 , 14 , the sealing effect of such a configured gap seal is considerably increased. The formation of the positive connection takes place during the simultaneous injection of injection pins 10 in the manufacture of the hous ses and the formation of the flap surface 11 of the flap 4 connected to the shaft 3 in one piece. The flap 4 is moved back and forth in the direction of the double arrow 32 between its maximum open position and its closing the flow cross section 2, closed position. To move the shaft 3 are servomotors whose drive torque is to be kept as low as possible for reasons of drive design. The ribs 6 and 31 stiffening the flap surface 11 can be optimized after various uses, both improving the flow properties of the fluid passing through the flow cross-section 2 with respect to turbulence or mixing, as well as stiffening the flap surface 11 of the flap 4 can. The inner bore of the bearing body 9 , which sits on the region 28 of the shaft 3 to be machined, is designated by reference numeral 29 .

The manufactured according to the manufacturing method proposed according to the invention Flap arrangements for controlling a gas flow can be used in addition to the application Internal combustion engines can also be used on piping systems for gaseous media find.  

LIST OF REFERENCE NUMBERS

1

casing

2

Flow area

3

flap shaft

4

Flap (open position)

5

center line

6

Verrippungsmuster

7

storage place

8th

attachment

9

bearing body

10

Anspritzzapfen

11

flap surface

12

Interface

13

head Start

14

recess

15

contact surfaces

16

sealing surface

17

Inner wall housing

18

Cross section of valve shaft

19

Fold cross-section area

20

sealing chamfer

21

top

22

helix angle

23

shaft journal

24

gas flow

25

peripheral surface

26

Wall thickness

27

outer wall

28

Seat bearing body

29

Bore bearing body

30

Outer surface of the bearing body

31

ribbing

32

direction of rotation

Claims (12)

1. Method for producing a flap arrangement ( 4 ) for controlling a gas flow ( 24 ) with the following method steps:

• - Providing a shaft ( 3 ) on seat surfaces ( 28 ) with bearing bodies ( 9 ),
• - inserting the preassembled module ( 3 , 9 ) into an injection mold,
• - The encapsulation of the preassembled, the shaft ( 3 ) with bearing body ( 9 ) comprising the assembly by way of the one-component injection molding process with simultaneous formation of a flap ( 4 ) and a housing ( 1 , 10 ) surrounding it and the bearing body ( 9 ).

2. The method according to claim 1, characterized in that during the encapsulation of the La gerkkörper ( 9 ) between these and the surrounding gudgeon pin (10) a positive, a pivoting movement ( 32 ) of the flap ( 4 ) enabling connec tion is generated. 3. The method according to claim 2, characterized in that projections ( 13 ) of the spigot (10) engage in recesses ( 14 ) of the bearing body ( 9 ). 4. The method according to claim 1, characterized in that the bearing body ( 9 ) before the encapsulation in the injection mold with a lubricant ( 12 ) who treated the. 5. The method according to claim 1, characterized in that the flap ( 4 ) is formed during the extrusion coating in an open position in the flow cross section ( 2 ) of the housing ( 1 , 10 ). 6. The method according to claim 5, characterized in that the flap ( 4 ) with respect to the housing ( 1 , 10 ) is oriented in a maximum open position. 7. The method according to claim 1, characterized in that the bearing body ( 9 ) of the shaft ( 3 ) on an inner wall ( 17 ) of the housing ( 1 , 10 ) are positioned adjacent. 8. The method according to claim 1, characterized in that on the flap surface ( 11 ) of the flap ( 4 ) on one or both sides a ribbing ( 6 , 31 ) is formed. 9. The method according to claim 1, characterized in that in the formation of the flap surface ( 11 ) of the flap ( 4 ) whose peripheral surface ( 25 ) is provided with a sealing bevel ( 20 ). 10. Device for controlling a gas flow ( 24 ), manufactured according to one or more of claims 1 to 9, characterized in that the bearing body ( 9 ) are made of sintered bronze or steel impregnated with a lubricant. 11. The device according to claim 10, characterized in that between the outer surface ( 30 ) of the bearing body ( 9 ) and the inner surface of the injection pin (10) of the Ge housing ( 1 ) a gap seal generating number of projections ( 13 ) and recesses ( 14 ) are formed. 12. The apparatus according to claim 11, characterized in that between the inner wall ( 17 ) of the housing ( 1 , 10 ) and the outer surface ( 30 ) of the bearing body ( 9 ) a sealing surface ( 16 ) is provided.