EP1051566A1

EP1051566A1 - Butterfly valve body

Info

Publication number: EP1051566A1
Application number: EP99960987A
Authority: EP
Inventors: Thomas Hannewald; Armin Seeger; Wilhelm Bock
Original assignee: Mannesmann VDO AG; Siemens AG
Current assignee: Siemens AG
Priority date: 1998-11-26
Filing date: 1999-11-19
Publication date: 2000-11-15
Anticipated expiration: 2019-11-19
Also published as: US6352241B1; JP2002530587A; DE59909471D1; DE19854595A1; BR9907249A; EP1051566B1; WO2000031396A1; KR20010034386A; MY119769A

Abstract

The invention relates to a butterfly valve body (1) having a butterfly valve housing (2) made of a plastic material. In a section of a line (3) of the butterfly valve housing (2) a butterfly valve (5) is mounted in a pivoting manner. According to the invention a metal cylinder (12) is provided for in said section of line (3) at least in a partial pivot range of the butterfly valve (5).

Description

Throttle body

description

The invention relates to a throttle valve assembly with a plastic throttle body according to the features of the preamble of claim 1.

Throttle body of throttle body are usually made of die-cast aluminum. However, this has the disadvantage that a complex and careful reworking is necessary, with the additional factor that such throttle valve housings are heavy and have poor corrosion resistance.

Therefore, it has already been considered to manufacture the throttle valve body from plastic by injection molding. Such throttle valve housings made of plastic have the advantage that they have a lower weight than aluminum housings, that the production material is less expensive and also that inserts, for example for storage, can be pressed into openings formed during the injection molding process, so that postprocessing is no longer necessary at all is or can be significantly minimized.

However, throttle valve bodies made of plastic have the disadvantage that they shrink during and after the injection molding process and can warp after removal from the mold. The same applies to the effects of temperature and force, especially since such throttle valve bodies are arranged in the engine compartment of vehicles, where they are subject to very large temperature fluctuations. If, for example, the drive motor of the vehicle is not in operation and there is little Outside temperature, very low temperatures are reached (for example, around freezing or even below); on the other hand, a very high temperature (in particular above 100 ° C.) is reached when the internal combustion engine is operating. Therefore, particularly due to these strong temperature fluctuations, there are disadvantageous deformations in the pivoting range of the throttle valve, so that the high leakage air requirements, in particular in the idle position of the throttle valve and around it, cannot be met. This area is particularly important because it has a major impact on fuel consumption and exhaust gas quality. It is therefore particularly important that the intake wall of the throttle valve assembly maintains its dimensional stability both under the conditions mentioned and over a long time, in particular over several years.

Therefore, it has already been proposed in DE 43 34 180 A1 that an annular insert part is embedded transversely to the intake duct in the throttle valve connector made of plastic, this insert part having angled tabs through which the throttle valve shaft protrudes and the tabs each facing away from the throttle valve Tab surface on one of the throttle valve bearing face of the bearing devices. First of all, this ring-shaped insert has the disadvantage, due to its geometrical design, that it is costly to manufacture, in particular in the case of series production of throttle body.

The main disadvantage, however, is that the ring-shaped insert is completely surrounded by plastic after the injection molding process, so that the throttle valve again has a large plastic inner contour of the intake wall in its swivel range. Due to the high requirements with regard to environmental protection (exhaust gas quality) and fuel consumption is still the required dimensional accuracy, even if it has already been slightly improved, so that the plastic intake wall can deform, contract or expand despite the ring-shaped insert, so that the high leakage air requirements still do not be fulfilled.

The invention is therefore based on the object of further improving such a throttle valve assembly, so that the requirements relating to exhaust gas quality and fuel consumption, but at the same time also with regard to a uniform response of the internal combustion engine to accelerating, are met. The advantages of a plastic throttle body should not be abandoned.

This object is solved by the features of claim 1.

According to the invention it is provided that a metal cylinder is provided in the line section at least in a partial swiveling range of the throttle valve.

Due to the stability of a metal cylinder, the throttle valve is always presented with a precisely defined and dimensionally stable inner wall, at least in the partial swiveling range in question, which does not change or changes negligibly even during temperature fluctuations and over a long period of time, so that the required dimensional accuracy is given. The metal cylinder can be inserted into the injection mold and then overmolded with plastic so that its inner wall remains free, so that the throttle valve is thus presented with a metallic surface. Alternatively, it is also possible to first produce the plastic throttle valve housing and then insert the metal cylinder. It is also conceivable to manufacture the metal cylinder from several parts, two halves, for example, being able to abut one another in the plane in which the throttle valve shaft is located. One could also think of covering the inner wall of the metal cylinder with a thin protective layer (for example made of the same plastic from which the throttle valve housing is made), the thickness of which has no influence on the dimensional accuracy. Such a protective layer effectively prevents the deposition of disruptive particles on the inner wall.

In a further development of the invention, the metal cylinder is provided in the flow direction below and / or above the throttle valve shaft carrying the throttle valve. The area around the plane in which the throttle valve shaft is arranged is particularly important, since this is the area in which the idle speed is set with the throttle valve. Good dimensional accuracy is therefore required, particularly in this area, which is achieved with the metal cylinder. In addition, the metal cylinder can also extend over a larger pivoting range of the throttle valve and, if necessary, also beyond.

In a further development of the invention, the metal cylinder is designed to receive the bearings of the throttle valve shaft. This results in a further increase in strength, which also simplifies the manufacturing process. The metal cylinder can first be manufactured, which is then provided with the throttle valve bearings and then overmolded with plastic. Another advantage can be seen in the fact that different metal cylinders (in particular with different longitudinal dimensions and / or different diameters) can be used in one and the same shape for the throttle valve housing, so that the Variety of parts, especially the number of shapes for the throttle body, can be reduced.

In a further development of the invention, the metal cylinder is also designed to accommodate further elements of the throttle valve assembly, such as for example to accommodate a throttle valve potentiometer or a drive motor. Further elements of the throttle valve assembly can also be shafts for a transmission via which the throttle valve shaft is driven by an electric motor. Likewise, holes can be provided in the metal cylinder, to which the further elements, such as a carrier plate of the throttle valve potentiometer, are screwed after the production of the throttle valve housing. The metal cylinder can also have stops, for example for an end position of the throttle valve or throttle valve.

In a further development of the invention, the metal cylinder has an inner contour to achieve a predeterminable characteristic curve for the volume throughput as a function of the pivoting of the throttle valve. By producing a corresponding metal cylinder, for example from die-cast aluminum or magnesium (other materials and manufacturing processes are also possible) and any post-processing that may be required, the inner contour of the metal cylinder can be used to achieve a characteristic curve for the volume throughput through the line section, which is dependent on one another from the pivoting of the throttle valve. Thus, for example, an inner contour can have the result that, in the closed position of the throttle valve, there is almost no volume flow through the line section. The one end position, which was previously referred to as the closed position, does not necessarily have to completely close the line section, but it can be in this End position is also a minimum position in which a defined amount of leakage air flows through the line section. With increasing pivoting of the throttle valve from the closed position or the minimum position, the volume throughput increases further depending on the inner contour used, until a further end position, which in particular represents a complete opening of the line section, is reached.

In summary, it can be stated that with the invention the advantages of a throttle valve housing made of plastic (such as low weight and low material costs) are retained, but the disadvantages existing in a throttle valve housing made of plastic, such as insufficient dimensional accuracy, are eliminated by using the metal cylinder, so that the desired Characteristic curve can be set and maintained even in the event of temperature fluctuations and over a long period (several years).

The throttle valve assembly according to the invention can be a so-called coupled system, in which the throttle valve is connected to an accelerator pedal to request power via connecting elements such as Bowden cables or the like. It is also conceivable in such systems to additionally carry out superimposed control (in particular idle control) in partial areas (in particular in the idle area) via an actuator (in particular an electric motor). The throttle valve assembly is also used in so-called drive-by-wire systems, in which the power requirement (for example actuating an accelerator pedal) is converted into electrical signals, the signals being fed to a control unit, which in turn controls an actuator, which then actuates the throttle valve at least in Depends on the performance requirement and, if necessary, other parameters.

The present invention is explained using the example of a throttle valve assembly, this field of application being regarded as preferred; however, the present invention is not limited to this exemplary embodiment, but can also be used in a corresponding manner, possibly with slight modifications under the first name, in other fields of application.

Show it:

FIG. 1: a throttle valve connector in a three-dimensional sectional view,

FIG. 2: the throttle valve connector according to FIG. 1 in cross section with the cover removed,

FIG. 3: the throttle valve connector according to FIG. 1 in cross section with the cover attached,

FIG. 4: the throttle valve connector in longitudinal section according to FIG. 1,

FIG. 5: the throttle valve connector according to FIG. 1 in a sectional, three-dimensional view,

FIG. 6: the throttle valve connector in section in a modified version compared to FIG. 1, Figure 7: the throttle valve neck in longitudinal section according to Figure 1, with a metal cylinder with an inner contour.

Figure 1 shows a throttle valve connector 1 in a three-dimensional sectional view. Such throttle valve connectors are used to supply air or a fuel / air mixture to the injection device of an internal combustion engine, in particular for a vehicle. For this purpose, the throttle valve body 1 has a throttle valve housing 2, which is made of plastic, in particular in an injection molding process. In this throttle valve housing 2 there is a line section 3 via which the air or the fuel / air mixture is fed to the injection device (not shown). To adjust the volume to be supplied, a throttle valve 5 is arranged on a throttle valve shaft 4, the throttle valve 5 also being pivoted by rotation of the throttle valve shaft 4 and the cross section in the line section 3 being increased or decreased to a greater or lesser extent and thus regulating the volume throughput.

In a simple embodiment of the throttle valve body 1, one end of the throttle valve shaft 4 is connected, for example, to a rope pulley, this rope pulley in turn being connected via a Bowden cable to an adjusting device for a power request, the adjusting device being, for example, the accelerator pedal of a vehicle, so that through Actuation of this setting device by the driver of a vehicle, the throttle valve 5 can be brought from a position of minimal opening, in particular a closed position, to a position of maximum opening in order to be able to adjust the power output of the internal combustion engine. y

The throttle valve connector 1 shown in FIG. 1 is such a throttle valve connector, in which the throttle valve 5 can be adjusted either in a partial area, for example the idling area, by an actuator, otherwise via the accelerator pedal, or in which the throttle valve 5 can be adjusted the entire adjustment range is adjustable by one actuator. In these so-called “E-gas” or “drive-by-wire” systems, the power requirement is converted into an electrical signal, for example by depressing the accelerator pedal, this signal being fed to a control unit, which then generates a control signal for the driver Actuator generated. This means that in these systems mentioned there is no mechanical connection between the setpoint specification (accelerator pedal) and the throttle valve 5.

Therefore, the throttle valve housing 2 of the throttle valve connector 1 has a gear housing 6 and a drive housing 7, wherein in a preferred embodiment the throttle valve housing 2, the gear housing 6 and the drive housing 7 form an integral unit and are produced in the same manufacturing process. Such an arrangement is also conceivable, in which individual housings can be assembled. In the drive housing 7 there is an electric motor (not shown in FIG. 1) which acts as an actuator and which acts on the throttle valve shaft 4 via a reduction gear (also not shown in FIG. 1), so that the throttle valve 5 is pivoted by actuation of the electric motor. The electric motor is controlled via a plug 8 arranged in the gear housing 6, the throttle valve connector 1 being connected to a control unit via the plug 8. The connector 8 also provides feedback of the respective position of the throttle valve 5 to the control unit, this control unit regulating the electric motor by comparing the setpoint (accelerator pedal) with the actual value for the position of the throttle valve 5 the difference between the setpoint and actual value is zero. The actual position of the throttle valve 5 can be detected by a corresponding sensor, in particular a so-called throttle valve potentiometer, in which the wiper of the potentiometer is connected to the throttle valve shaft 4.

The gear housing 6 including the drive housing 7 is closed by a housing cover 9. The design and assembly of the housing cover 9 is described in more detail in FIGS. 2 and 3.

The throttle valve assembly 1 is generally arranged in a suction system of the internal combustion engine and is mounted as a module, for which purpose the throttle valve assembly 1 shown in FIG. 1 has a flange 10 with which it can be connected to an intake air filter via a suction line (not shown) or directly with this Intake air filter is connected. For fastening the throttle valve connector 1 to the injection device with the side facing away from the flange 10, bores 11 are provided with which the throttle valve connector 1 can be screwed tightly to the injection device. The type of attachment is only exemplary and not essential to the invention.

Furthermore, in the three-dimensional sectional view of the throttle valve connector 1, a metal cylinder 12 shown in broken lines is arranged in the line section 3. The outer circumferential surface of the metal cylinder 12 is completely surrounded by the plastic of the throttle valve housing 2, the metal inner wall of the metal cylinder extending over the pivoting area of the throttle valve 5, possibly a little less or a little more than this pivoting area. Sales Different configurations of the metal cylinder 12 can be seen in the following figures.

FIG. 2 shows the throttle valve assembly 1 according to FIG. 1 in section with the housing cover 9 removed. The position of the metal cylinder 12, which in simple form is a piece of pipe and has bushings 13 for the throttle valve shaft 4, can be seen very clearly in this cross section. The inner wall of the metal cylinder 12 can be machined in a contoured manner in order to be able to set predetermined characteristics for the volume throughput through the line section 3 as a function of the position of the throttle valve 5. FIG. 2 shows an embodiment of the metal cylinder 12 in which the metal cylinder 12 has an extension 14 in the area of the bushings 13, these extensions 14 accommodating bearings 15, 19 for the throttle valve shaft 4. This increases the ease of installation, since after the metal cylinder 12 has been encapsulated with plastic to form the entire throttle valve housing 2, the bearings for the throttle valve shaft 4 are already available. The throttle valve shaft 4 ends - when viewing FIG. 2 on the left-hand side - in a space 16 in which, for example, so-called return springs and emergency running springs can be accommodated. The return spring biases the throttle valve shaft 4 in the closing direction so that the actuator works against the force of this return spring. A so-called emergency spring causes the throttle valve 5 to be brought into a defined position if the actuator fails, which is generally somewhat above the idling speed. As an alternative or in addition to this, the throttle valve shaft 4 can also protrude from the throttle valve housing 2 beyond the space 16, in which case, for example, a cable pulley is then mounted on this end of the throttle valve shaft 4, which is connected to an accelerator pedal via a Bowden cable, thus providing a mechanical setpoint is realized. The space 16 turned end of the extension 14 (its end face) can be used to accommodate other elements such as the attachment of a support plate of the throttle valve potentiometer. Likewise, the end face of this extension 14 or further extensions, the end faces of which protrude into the gear housing 6, can be used to accommodate further elements, such as stub shafts for gears or toothed segments of the gear, not shown.

The throttle valve housing 2 further has a circumferential flattening 17 pointing in the direction of the housing cover 9, which corresponds to a circumferential web of the housing cover 9. So far, it has been the case that the housing cover 9 has been connected to the throttle valve housing 2 by screwing or by means of clip connections with the interposition of a seal. This meant a great deal of effort, since corresponding designs had to be provided for the production of the mold for the throttle valve housing 2 and the housing cover 9. In addition, the presence of the seal meant another component and the associated insertion of the seal meant a further assembly step, which turned out to be disadvantageous in particular in the series production of throttle valve bodies. Due to the circumferential flattening 17 on the throttle valve housing 2 and the circumferential web 18 on the housing cover 9 (or vice versa), which can already be provided for the shape of the throttle valve housing 2 and the housing cover 9 made of plastic during manufacture, it is first achieved that after the placement of the housing cover 9, a defined position on the throttle valve housing 2, optionally with a slight play, is achieved.

FIG. 3 shows the throttle valve connector 1 according to FIG. 1 in cross section with the housing cover 9 attached. The web 18 now lies all around the flat 17, which both overlap. A laser beam 20 is now directed all around this area of this overlap, which is aligned and dimensioned in terms of its intensity such that the two mutually facing surfaces of the flattened area 17 and the web 18 heat up and begin to melt. As a result, the throttle valve housing 2 merges with the housing cover 9 all around at this point, so that the gear housing 6 and the drive housing 7 located under the housing cover 9 are sealed. There is no need to insert and mount a seal. The housing cover 9 is non-detachably connected to the throttle valve housing 2, that is, it cannot be detached from the throttle valve housing 2 without destroying the components involved. In addition to the absolute tightness, this has the advantage that all components that are arranged in this room are protected against manipulation. This is particularly advantageous if an electronic control unit is accommodated in the throttle valve housing 2, covered by the housing cover 9.

The housing cover 9 shown in Figure 3 also has a counter bearing 21 with which the drive shaft of the electric motor, not shown, is mounted. Likewise, the throttle valve shaft 4 can also be counter-supported by means of a counter bearing 22.

FIG. 4 shows the throttle valve connector 1 in longitudinal section according to FIG. 1. Here it can be seen that the metal cylinder 12 is designed as a simple cylinder, the outer peripheral surface and at least part of the end faces of which are surrounded by the plastic of the throttle valve housing 2. The inward-facing inner wall of the metal cylinder 12 is formed in a straight line, but can also be contoured in order to implement specifiable characteristics for the volume throughput. Such design for example, are shown in FIG. In Figure 4, the throttle valve 5 is shown in its closed position and can be brought into an open position by turning counterclockwise, with a rotation of about 90 ° (that is to say in a position which is approximately vertical when viewing Figure 4) the full -Load position corresponds.

FIG. 5 shows the throttle valve connector 1 according to FIG. 1 in a sectional, three-dimensional view, the arrangement of the metal cylinder 12 in the throttle valve housing 2 again being visible. A possibility of mounting the throttle valve 5 on the throttle valve shaft 4 can also be seen. The throttle valve shaft 4 has a slot into which the throttle valve 5 can be inserted, the throttle valve 5 being fixed immovably on the throttle valve shaft 4 after alignment in its desired position. This can be done for example by means of pins or screws which are inserted through the throttle valve shaft 4 and the throttle valve 5. Alternatively, the throttle valve 5 can also be caulked or glued in the slot with the throttle valve shaft 4.

Figure 6 shows the throttle valve connector 1 in section in a modified version compared to Figure 1, wherein it can be seen that the metal cylinder 12 not only receives the extensions 14 for receiving the bearings 15, 19 for the throttle valve shaft 4, but also includes a bearing plate 23 which one end of the actuator designed as an electric motor. This increases the strength, and it should be mentioned as a further advantage that a heat loss generated during operation of the electric motor is conducted to the inner wall of the metal cylinder 12 via the end shield 23, the heat loss through the air flowing through the line section 3 at this point (or the fuel-air mixture) is discharged. The bearing plate 23 1 o

also improved the thermal properties of the throttle valve body 1.

FIG. 7 shows the throttle valve connector 1 in longitudinal section according to FIG. 1, the metal cylinder 12 being shown here with an inner contour. In Figure 7 it can be clearly seen again that the metal cylinder 12 is inserted into the plastic throttle body or is surrounded by the plastic in such a way that the metal cylinder 12 is held securely in the throttle body 2, while the inner wall of the metal cylinder 12 is not Plastic is covered, so the metallic properties are retained. The throttle valve 5 can be pivoted by rotating the throttle valve shaft 4 - when viewing FIG. 7 clockwise - in a pivoting direction 24 from the minimum position shown in FIG. 7, in which the line section 3 is completely or almost completely closed. The air flowing through the line section 3 (or the fuel! Uftge mixture) has a flow direction 24. By pivoting the throttle valve 5 in the pivoting direction 24, the line section 3 is opened further with increasing pivoting, so that an inner contour 26 of the metal cylinder 12 provides a characteristic curve of the Line section 3 flowing volume is adjustable depending on the opening angle of the throttle valve 5. By means of different inner contours 26, which can be realized with different metal cylinders 12, different characteristic curves adapted to the respective type of internal combustion engine can be realized in a simple manner while maintaining a standardized throttle valve housing 2. The inner contour 26 of the metal cylinder 12 shown in FIG. 7 is symmetrical above and below the throttle valve shaft 4, with the throttle valve 5 starting in the pivoting direction 24, starting from the minimum position (or also zero position) shown in FIG. 7 the inner contour 26 initially has a straight cylindrical section, which is followed by an arcuate section.

It is desirable that in the transition area between the inner wall of the line section 3 and the inner wall of the metal cylinder 12 there is no shoulder in order to avoid swirling of the air or the fuel / air mixture in the direction of flow 25.

It is pointed out, however, that the inner contour 26 of the metal cylinder 12 shown in FIG. 7 is only exemplary and any other contours (also asymmetrical contours above and below the plane of the throttle valve shaft 4) can be achieved when manufacturing and / or machining the metal cylinder 12.

Reference list

1. Throttle body

2. Throttle body

3rd line section

4. Throttle valve shaft

5. Throttle valve

6. Gear housing

7. Drive housing

8. Connector

9. Housing cover

10. Flange

11. Hole

12. Metal cylinder

13. Implementation

14. process

15. Camp

16. room

17. Flattening

18.bridge

19th camp

20. Laser beam

21. Counter bearing

22. Counter bearing

23. End shield

24. Swivel direction

25. Flow direction

26. Inner contour

Claims

claims

1. throttle valve assembly (1), having a throttle valve housing (2) made of plastic, a throttle valve (5) being pivotally mounted in a line section (3) of the throttle valve housing (2), characterized in that at least in a partial pivoting range of the throttle valve (5) a metal cylinder (12) is provided in the line section (3).

2. Throttle valve connector (1) according to claim 1, characterized in that the metal cylinder (12) is inserted in the plastic of the throttle valve housing (2), the metal inner wall of the metal cylinder (12) being exposed in the region of the line section (3).

3. Throttle valve connector (1) according to claim 1 or 2, characterized in that the metal cylinder (12) is provided in a flow direction (25) below and / or above a throttle valve shaft (4) carrying the throttle valve (5).

4. Throttle valve connector (1) according to one of claims 1 to 3, characterized in that the metal cylinder (12) is designed to receive the bearings (15, 19) of the throttle valve shaft (4).

5. Throttle valve assembly (1) according to one of the preceding claims, characterized in that the metal cylinder (12) is designed to accommodate further elements of the throttle valve assembly (1), such as a throttle valve potentiometer, a drive motor or the like. Throttle valve connector (1) according to one of the preceding claims, characterized in that the metal cylinder (12) has an inner contour (26) to achieve a predeterminable characteristic curve for the volume throughput through the line section (3) as a function of the pivoting of the throttle valve (5).