WO1995006809A1

WO1995006809A1 - Throttle device

Info

Publication number: WO1995006809A1
Application number: PCT/EP1994/002880
Authority: WO
Inventors: Otto Altmann; Gerhard Brenner
Original assignee: Filterwerk Mann & Hummel Gmbh
Priority date: 1993-09-02
Filing date: 1994-08-31
Publication date: 1995-03-09
Also published as: DE4329526A1

Abstract

The invention concerns a throttle device, especially a butterfly valve (12) in an intake pipe of an internal combustion engine. It has a butterfly spindle (11) running concentrically to a central axis and the throttle butterfly (12) and the surrounding housing (10) have facing sealing surfaces. The sealing surfaces are fitted with at least one elastomeric seal.

Description

description

Throttle device

The invention relates to a throttle device according to the preamble of the main claim.

A throttle valve is known for example from EP 498 933 A1. This is integrated in a housing that can be attached to a carrier body. The housing is designed in the manner of a throttle valve connector, that is, the connector is fixed on the one hand to the carrier body and on the other hand to the intake system of an internal combustion engine.

A disadvantage of this structure can be seen in the fact that a high outlay on components is required and a larger number of sealing elements between the individual components is required, throttle systems made of metallic materials being known to have high leakage rates.

It is also known from DE 38 003 87 A1 a throttle valve with a special type of idle control. This throttle valve is arranged in a tubular opening, this opening having certain types of depressions which are used for idle air control. Such a throttle valve is, however, very difficult to manufacture in terms of production technology, since a high cross section of the appli-cade is optimally sealed Manufacturing accuracy is required, which can only be achieved with a high manufacturing effort.

The invention has for its object to provide a throttle device that can be produced economically and a reliable effective seal of the throttle cross section he ögl icht.

This object is achieved on the basis of the preamble of the main claim by its characterizing features.

An important advantage of the invention is that the consistent use of plastic in the intake tract of an internal combustion engine is largely taken into account. Because of the low modulus of elasticity, plastic in particular results in a much lower specific material stress, e.g. with Hertzian surface pressure due to the greatly enlarged contact surface due to the deformation than with steel pairings. In combination with an elastomer seal, the throttle cross-section is optimally sealed and thus extremely low leakage rates.

Another advantage of the invention is that a sealing bead is provided on the housing of the throttle device, on which the throttle valve rests, so that the sealing surface can be defined.

According to an advantageous embodiment of the invention, the elastomer seal is integrated in the sealing surfaces in a two-component process. In the two-component process, the base body is first injected in an injection mold, then gap openings are opened inside the injection mold in the areas in which the elastomer seal must be arranged, and these openings are filled with the elastomer sealing compound. After the manufactured part has cooled, it can be used in the tool be removed.

According to a further embodiment of the invention, a small radial gap is provided between the throttle valve and the housing surrounding the throttle valve, that is to say, for example, the throttle valve connector. This ensures that out-of-roundness, as can occur, for example, due to warping, does not lead to the throttle valve jamming.

With a plastic throttle valve, it is advantageous if the idle air control can be integrated into the design of the throttle valve or the entire throttle device. For this purpose, the wall of the housing runs within a certain angular range of the throttle valve in the manner of an idling gap curve, i.e. When the throttle valve opens, the gap between the throttle valve and the housing, which is initially close to zero, becomes progressively larger; from a certain angular position of the throttle valve, the idle air gap changes into the normal throttle valve opening. With suitable control elements, the throttle valve can be controlled within this idle air gap area, so that complex idle air control with additional valves, bypasses and the like. . can be avoided.

An advantageous method for producing the throttle device is also described.

It is of course expedient to manufacture the housing of the throttle device using the plastic injection molding process. It is also possible to manufacture the housing using extrusion technology, by pressing, rotary centrifugal technology or other processes. Basically, the entire working range of the throttle valve is 90 degrees, with the control taking place in the entire range with a high degree of accuracy. It is advantageous to the saddle, ie the support for the Throttle valve, which simultaneously exerts the sealing effect, to be connected directly to the housing, ie to produce the saddle and housing in a single injection mold.

An alternative variant provides for this saddle to be retrofitted with a housing deformation, i.e. to form by thermal deformation of the housing. The advantage of this thermal deformation can be seen in the fact that a constant wall thickness of the housing is guaranteed. However, this constant wall thickness can also be ensured in the aforementioned method by the appropriate design of the injection mold.

A further embodiment of the throttle device provides for a so-called relaxation process to be used for optimum sealing between the throttle valve neck and the throttle valve. This means that the throttle valve experiences a reduction in elasticity, which is advantageously done by tempering. The temperature control is in the zero position, i.e. made in the position in which the throttle valve rests on the throttle valve connector or the sealing shoulder of the throttle valve connector.

This relaxation process causes the plastic of the throttle valve to creep or flow and thus to adapt this throttle valve to the shape of the throttle neck. The process is interrupted as soon as the throttle valve has reached its optimal shape, i.e. as soon as the sealing behavior corresponds to the specified value.

These and further features of preferred developments of the invention are evident from the claims and also from the description and the drawings, the individual features individually or in groups in the form of Sub-combinations can be realized in the embodiment of the invention and in other fields and can represent advantageous and protectable versions for which protection is claimed here.

The invention is explained in more detail below on the basis of exemplary embodiments. It shows:

Figure 1 is a throttle valve installed in a throttle valve in the 0 degree position

FIG. 1a shows a detail from FIG. 2

1b shows a further detailed representation from FIG. 1

Figure 1c shows a variant of Figure 1a

Figure 2 shows an injection molding tool for producing a throttle valve in 2K technology

FIG. 3 shows the function of the idle gap setting in a throttle valve,

FIG. 3a shows a detail from FIG. 3,

4a, b throttle valve variants in cross section,

FIG. 5a, b throttle clamps 1 types of agers,

FIG. 6 shows a throttle valve with a Venturi nozzle for feeding in additional air,

FIG. 7 shows a detailed illustration of a throttle valve, FIG. 8 shows the seal of the throttle valve,

FIG. 9 shows a shaft seal, in particular a throttle valve shaft seal,

10a, b the detailed representation of a throttle valve during a relaxation process,

Figure 11 shows the detail of a throttle valve with tolerance compensation.

The throttle device according to FIG. 1 consists of a throttle valve connector 10, in which the throttle valve 12 is mounted via a throttle valve shaft 11. The throttle valve has an opening angle of 90 degrees and reliably seals the cross-section of the throttle valve in the rest position shown here. The seal between the sealing saddle 13 of the throttle valve assembly 10 and the throttle valve 12 can be implemented in different ways.

In Figure 1, the sealing area between the throttle valve assembly 10 and the throttle valve 12 is shown in an enlarged detail. The throttle valve 12 is provided on the sealing surface with an elastomer seal 14. This elastomer seal rests on the sealing saddle 13 of the throttle valve connector 10 when the throttle valve is closed.

A variant is shown in FIG. 1c. Here there is an elastomer seal 15 in the sealing saddle 13 of the throttle valve connector 10. Of course, there is also the possibility of equipping both the throttle valve and the throttle valve connector with sealing components, the use of plastic for the individual parts simply because of the lower elasticity module for a significantly better sealing effect against metal throttle valves. FIG. 1b shows, in a further detailed illustration, one possibility for producing the sealing saddle 13. This sealing saddle 13 can be produced by an embossing tool 16, which acts on the throttle valve connector and subsequently thermally deforms it. In order to prevent jamming between the throttle valve 12 and the throttle valve body 10, the outer diameter of the throttle valve 12 is slightly smaller than the inner diameter of the throttle valve body 10, so that a gap S (0.1 to 0.5 mm) is formed, which is selected in this way that out-of-roundness, such as might occur due to shrinkage or warpage, is not a problem.

Figure 2 shows an injection mold for producing a throttle valve in 2K technology. The injection mold consists of an upper part 17 and a lower part 18. A slide 19, 20 is arranged in each of the upper and lower part, which forms two different cavities in connection with the injection mold. To produce a throttle valve 12, the tool is closed and the slides 19, 20 are moved into the starting position. This starting position is represented by the slide 20. In this state, the first cavity is filled with thermoplastic. The slides 19, 20 are then pulled back into the position represented by the slider 19 and the second cavity that is formed is filled with an elastomer sealing compound 21. It is possible to inject the throttle valve shaft into the throttle valve in a next operation. After opening the tool, a complete throttle valve can be removed. The elastomer seal can also be clamped between an upper throttle valve part and a throttle valve part 1.

Figure 3 shows the function of the idle gap setting, which is shown again in Figure 3a in an enlarged view is. The throttle valve essentially corresponds to that shown in FIG. 1. The throttle valve connector 10 is designed in its wall such that it represents a tightly fitting shape in the rest position of the throttle valve 12 and takes into account a corresponding gap S as a tolerance gap. Within the angular range Alpha L, the gap 22 between the throttle valve and throttle valve connector increases slightly as the throttle valve opens until the throttle valve leaves the wall area of the throttle valve connector 10 and is turned into the open position.

The dimensioning of the gap 22 is chosen so that an idle control of an internal combustion engine is possible, i.e. the throttle valve will move within the angle Alpha L when idling. It is only when accelerating from idle that the throttle valve is opened further, leaves the idling range and changes to the progressive opening range.

If the idle gap curve is continued, a progression in the opening behavior of the throttle valve can also be integrated. Plastic throttle bodies and plastic throttle bodies are particularly suitable due to their simple Manufacture 1 process, several functions, such as to combine the integration of the sealing elements and combination with an idle gap setting.

FIG. 4a shows a throttle valve 12 in cross section, which consists of a thermoplastic plastic in its core and which is completely surrounded by an elastomer 23. Such a throttle valve is manufactured using the 2K process.

Figure 4b shows a variant. Here a throttle valve is shown, which is also completely covered by an elastomer. In the thermoplastic inner part 1 there is a metal core 24. By inserting a metal core, the throttle valve can be reduced in volume without fear of loss of strength.

5a and b show the bearing points of throttle valves, sealing lips 25, 26 being provided in each case, which are also formed by the elastomer coating 23 and provide reliable sealing of the throttle valve on the throttle valve shafts 11.

FIG. 6 shows a throttle valve 12 installed in a T-piece 28 of an intake system. This is opened by a Bowden cable according to arrow 27, not shown here. A connection in the form of a Venturi tube 29 is arranged on the right-hand tube wall of the T-piece 28. This can be used to supply additional fresh air or exhaust gas. Of course, this venturi tube is only effective when the drosel flap is open.

A detailed illustration of a throttle valve 12 is shown in FIG. This rotates around the axis center of the shaft 11 and closes off the throttle valve connector 10 in the rest position. As shown in FIG. 8, sealing takes place via a sealing edge 30 on the throttle valve connector 10. The throttle valve 12 with its elastomer seal 14 rests on this sealing edge.

In Figure 8, the tolerance compensation Delta T can be seen in particular. This prevents the throttle valve from jamming if the dimensions are small.

Three position phases of the throttle valve are shown in FIG. Starting from the zero position (0 °) to a position I (4 °), the throttle valve is closed. Only from this intermediate position I and position II (9 °) is the idle control range. It is in this area Throttle valve during the idling phase. This eliminates the need for a separate idle air duct. This idling range is progressive and goes into the full load range up to the 90 ° position of the throttle valve in phase three.

FIG. 9 shows a sealing measure for additional leakage air sealing, in particular in the case of a throttle valve storage. The throttle valve shaft 11 consists of a two-component material. The core of the throttle valve shaft, in particular a PPS plastic, is provided with an elastomer coating 31. This elastomer coating has the shape shown in the area of the seal. The throttle valve shaft is rotatably mounted within the throttle valve neck 10, in particular via a ball bearing 32. A PUR seal 33 is located between the ball bearing and the elastomer coating of the throttle valve shaft. A copper wire winding 34 is arranged on the throttle valve shaft 11. This serves for resistance welding and heats the shaft 11 and a sealing ring located on the shaft, which optimally contacts the shaft 11 by melting and thus ensures reliable leakage air sealing.

A detail of a throttle valve 114 is shown in FIG. 10a. This is arranged in a clean air pipe 110. A sealing surface 116 is provided on the clean air tube 110, on which the throttle valve rests. An elastomer seal 122 is integrated into the throttle valve 114 for reliable sealing. The outer contour of the throttle valve in the area of the surface 123 has a slightly smaller diameter than the inner diameter of the clean air tube 110.

To adjust the outer surface 123 to the contour of the clean air connector, the throttle valve is one

Subjected to tempering process. For this purpose, a force F is generated according to arrow 124 in FIG. 10b. This force F is in essentially formed by pivoting the throttle valve about the pivot point of the throttle valve shaft 115. Due to this force and the temperature control process, a resulting movement along the arrow SR will occur until the surface 123 of the throttle valve on the lower edge has adapted to the inner contour of the throttle valve body.

Of course, this relaxation process can also be achieved by other means, e.g. by ultrasound or other elasticity-reducing measures. It is crucial that the throttle valve is adapted to the existing contour.

FIG. 11 shows a further detailed illustration of a throttle valve. On the one hand, an elastomeric element 122 is arranged as a sealing element in this throttle valve. Furthermore, this throttle valve has an additional element 125. This has the task of decoupling the throttle valve region 126 from the throttle valve region 127. The element 125 can be an elastomer or a plastic with special flow properties. During the relaxation process, this decoupling element contributes to a better adaptation of the throttle valve contour to the contour of the clean air connector or the throttle valve connector, which is not shown in this drawing. Element 125 can also be produced in a two-step process using the two-component plastic injection molding process together with the throttle valve.

Claims

claims

1. throttle device, in particular throttle valve in an intake duct of an internal combustion engine, which has a concentric to a central axis throttle valve shaft, the throttle valve and the surrounding housing have mutually facing sealing surfaces, characterized in that the sealing surfaces of the throttle valve (12) and / or Sealing surfaces of the housing (10) are provided with at least one elastomer seal (14).

2. Throttle device according to claim 1, characterized in that the elastomer seal (14) is made in the 2K process.

3. Throttle device according to one of the preceding claims, characterized in that a slight gap (S) of 0.1 mm to 0.5 mm is provided between the throttle valve (12) and the surrounding housing (10) in the radial direction.

4. Throttle device according to claim 1, characterized in that the gap (22) between the throttle valve (12) and the housing (10) is designed such that when the throttle valve (12) is opened, a continuously or progressively increasing air gap, in particular for idle air control is formed and this gap increases progressively or linearly from a certain position angle of the throttle valve (12) for load control.

5. Throttle device according to one of the preceding claims, characterized in that the throttle valve completely by is surrounded by an elastomer coating and the core of the throttle valve is formed from a PPS plastic or from a plastic with a metal insert.

6. Throttle device according to claim 5, characterized in that the throttle valve is provided at the bearings with sealing lips, the sealing lips from the. the throttle valve surrounding elastomer are formed.

7. Throttle device according to one of the preceding claims, characterized in that the throttle valve shaft consists of a continuous or split shaft.

8. Throttle device according to one of the preceding claims, characterized in that a Venturi nozzle is arranged in the region of the throttle valve, through which additional air is fed into the intake area of the internal combustion engine.

9. Throttle device according to one of the preceding claims, characterized in that a sealing ring is arranged on the throttle valve shaft in the bearing area, which can be heated with an electrical winding (34), this sealing ring effecting a reliable leakage air seal due to resistance welding.

10. A method for producing a throttle device according to one of the preceding claims, characterized in that a housing (10) accommodating the throttle valve (12) is produced, in particular, by injection molding, the saddle (13) for supporting the throttle valve with the housing (10). forms a unit.

11. The method according to claim 5, characterized in that the saddle (13) is formed by a subsequent thermal deformation.

12. The method according to claim 5, characterized in that in the region of the saddle (13) the housing is formed with a constant wall thickness.

13. Throttle device according to one of the preceding claims, characterized in that the adaptation of the throttle valve to a sealing plane arranged in the intake duct of the internal combustion engine is carried out by relaxation.

14. Throttle device according to claim 13, characterized in that the relaxation takes place via a tempering process.

15. Throttle device according to claim 14, characterized in that the temperature control process takes place with the throttle valve installed in the throttle valve zero position.