EP1183451A1

EP1183451A1 - Device for resetting a throttle valve

Info

Publication number: EP1183451A1
Application number: EP01919223A
Authority: EP
Inventors: Klaus Kaiser; Uwe Hammer
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2000-03-21
Filing date: 2001-03-20
Publication date: 2002-03-06
Anticipated expiration: 2021-03-20
Also published as: DE10013917A1; WO2001071173A1; JP2003528250A; KR20020005044A; US20020162982A1; US6568652B2; DE50100118D1; AU772215B2; EP1183451B1; AU4638501A

Abstract

The invention relates to a device for resetting a throttle valve to a defined emergency air position for controlling the combustion air of an internal combustion engine. The inventive device comprises a throttle valve shaft (11) which is rotatably mounted in a housing (10) and carries a carrier (12) which can be driven. Said device also comprises a pre-stressed clamp spring (13). The spring ends (131, 132) of said clamp spring fix an emergency air position of the throttle valve (30) on stopper surfaces (16, 17) which are facing away from each other, by simultaneously embracing a stopper (14) of the housing and a stopper (15) of the carrier. The throttle valve (30) can be adjusted from said emergency air position by rotating the carrier (15). The aim of the invention is to obtain rotational freedom of the carrier (12) in the emergency air position between a spring end (131) of the clamp spring (13) and a stopper surface (16). A compensation spring (18) having a defined pre-stressing force which acts in the opposite direction in relation to the spring force of the clamp spring (13) is arranged on one of the stoppers (14).

Description

Device for resetting a throttle valve

State of the art

The invention is based on a device for

Provision of a throttle valve for the combustion air control of an internal combustion engine in a defined emergency air position according to the preamble of patent claim 1.

Such a reset device is used in the event of failure of the drive for the driver on the throttle valve shaft, the z. B. is an electric motor to reset the throttle valve to a defined rest position, the so-called emergency air or emergency running position, in which a minimal throttle valve opening for the combustion air supply

Internal combustion engine is ensured so that the latter still runs smoothly at idle or under minimal load. Due to tolerances on the housing and driver stop and due to the bending inaccuracy of the bent spring ends of the clamp spring, in the emergency air position, in which the driver stop and housing stop are approximately congruently offset, there is a certain torsional play of the throttle valve shaft, which makes precise regulation in this area impossible.

In a known reset device of this type (DE 197 35 046 AI) are provided to achieve a rotation-free execution with a defined rest position of the stops m the emergency air position on the housing and the driver stop oblique stop faces. One spring end of the clamp spring is held on the oblique stop faces on one side and the other Federenαe of the clamp spring on the other stop faces extending parallel to the driving axis on the other side of the housing and central stop. Due to the striking stop faces, the spring end is supported with half the spring force on each of the two striking stop faces and thereby adjusts the rotatable driver stop against that of the spring end on the other side of the housing or. Driver stop formed stop.

Advantages of the invention

The erfmdungsgemaiie R _^ ckstellvornchtung has the advantage that de Verdrehspieifreiheit _.n the emergency air with technically simple means is reliably achieved. The compensation spring can be made as a simple stamped part and is easy to assemble. The additional Manufacturing costs to achieve reliable freedom from play are thus minimal.

The measures listed in the further claims allow advantageous developments and improvements of the reset device specified in claim 1.

drawing

The invention is explained in more detail in the following description with reference to exemplary embodiments shown in the drawing. Show it:

Fig. 1 shows a partial side view of a device for resetting a

Throttle,

Fig. 2 shows a section along the line

Fig. 3 a section along the line

III - III m Fig. 1,

4 a section along the line IV - IV m Fig. 2,

5 shows an enlarged perspective view of a compensation spring m of the reset device according to FIGS. 1-4 or according to FIGS. 6-9, Fig. 6 is a perspective view of a

Assembly of a modified device for resetting a throttle valve,

7 each shows the same sectional view as and in FIGS. 2 and 3 of the modified FIG. 5 reset device,

9 a section of a section along the line IX - IX xn FIG. 7,

Fig. 10 shows a section of a diagram of the

Torque curve of the reset device on the throttle valve via its angle of rotation.

Descriptio _^ oung the Ausfuhrungsoe_Lspιele

The device shown in FIGS. 1-4 in a first exemplary embodiment and in FIGS. 7-9 in a modified exemplary embodiment in each case in side view with different sections for resetting a throttle cable lobe for controlling the combustion air of an internal combustion engine with a defined emergency air or The emergency running position has a throttle valve shaft 11 which is rotatably received in a housing 10 and on which a throttle valve 26 which can only be seen in FIG. 6 is seated in a rotationally fixed manner. As is known, the throttle valve 26 is arranged in an air intake port of the internal combustion engine and controls the opening of the intake cross section in the intake port d_e by means of less opening

Combustion engine intake amount of combustion air. To the antπeo of the throttle iappenwelle II this carries a rigid on her attached driver 12, wiro operated by a drive. The driver 12 preferably has a toothed segment which engages with a gear (not shown) which is seated on the output shaft of an electric motor.

In the housing 10, a clamp spring 13 is accommodated, which is designed as a cylindrical helical torsion spring and is arranged concentrically with the throttle valve shaft 11 and whose spring ends 131 and 132 are bent toward the throttle valve shaft 11. The clamp spring 13, which can be seen in a perspective view in FIG. 6, is already biased in the representation in FIG. 6, so that the two inwardly directed spring ends 131, 132 are crossed and run approximately parallel to one another. A force results from this pretension so that a part inserted between the spring ends 131, 132 is clamped. As can be seen from FIGS. 4 and 9, two stops 14, 15, which are formed by axial webs and are arranged radially offset from one another, are clamped between the two spring earths 131, 132 of the Klammerfeαer 13, both of which extend over at least the axial width of the Klammerteαer 13th and extending, l ⁷ for the spring ends have to aogekehrten from each other in the rotational direction sides of each stop surfaces 16,131 and 132nd The stop 14, hereinafter referred to as the housing stop 14, is fixed on the housing 10 and the stop 15, hereinafter referred to as the driver stop 15, on the driver 12. As can be seen from FIGS. 2 and 3 or FIGS. 7 and 8, the axial web forming the housing stop 14 is formed in one piece with the genause 10 and projects axially from the housing 10. The driver stop 15 is m Fig. 2 by a Angle leg of an angled metal part 21, which is also injected with its other angular leg m, the driver 12 made of plastic, realized, while the driver stop 15 m Fig. 8 and 9 as an axial web, which is reinforced by overmolding the angled metal part 21 also inserted, directly on Driver 12 is also injected. The length of the two bent spring ends 131, 132 of the clamp spring 13 is dimensioned such that it faces the stop faces 16 pointing in each case in the same direction of rotation on one side or

Ability to overlap stop surfaces 17 on the other side of the housing stop 14 and driver stop 15 facing away therefrom.

If the driver 12 of the drive, for. B. the

Electric motor, rotated in one or the other direction of rotation, when the driver 12 rotates clockwise (with reference to FIG. 1) the spring end 131 of the clamp spring 13 and when the driver 12 rotates counterclockwise (with reference to FIG. 1, the spring end 132 of the Clamp spring 13 is entrained in each case by the driver stop 15 and the clamp spring 13 is increasingly tensioned. If the drive fails, for example if the electric motor is de-energized, the driver 12 is turned back by the restoring force of the clamp spring 13, specifically in the opposite case Clockwise (with reference to FIG. 1) until the spring end 131 and in the other case clockwise (with reference to FIG. 1) until the spring end 132 hits the housing stop 14. In this position, the driver 12 takes over the throttle valve shaft 11 entrained throttle valve 26 a defined position, the so-called emergency air or emergency running position, a αer Defined opening of the throttle valve 26 is predetermined so that the internal combustion engine receives enough combustion air and runs evenly at idle or with a minimal load.

Due to tolerances on the two stops 14, 15 and due to the limited bending accuracy of the spring ends 131, 132, the emergency air position of the stops 14, 15, which defines the emergency air position of the throttle valve shaft 11 and with which these are aligned radially one above the other, is a g / There is a backlash which makes precise regulation of the internal combustion engine impossible in this area. This game arises, for example, from tolerances in the distance between the stop surfaces 16 and 17 seen in the direction of rotation

Housing stop 14 on the one hand and on the driver stop 15 on the other hand, that is to say by tolerances of the width of the axial webs forming the stops 14, 15, as well as by tolerances in the bending angle of the spring ends 131, 132, so that these do not lie flat against the

Bearing surfaces 16 or abut against the abutment surfaces 17 of the two abutments 14, 15, but are more or less set against them. The spring ends 131, 132 then lie, for example, only on the stop flaps 16, 17 of the housing stop 14 or on the stop faces 16, X ^"of the driver stop 15, and the driver 12 is not fixed without backlash in the emergency air position. In order to suppress the backlash, it is necessary between a spring end 131, 132 and a stop surface 16 or 17 on an oer stops 14, 15 a play compensation spring or

Compensation spring 18 with a counter to the restoring force the biasing spring 13 arranged biasing force. In the exemplary embodiment of the

1-4, the compensation spring 18 is arranged on the housing stop 14 and lies between the stop surface 16 on the housing stop 14 and the spring end 131 of the clamp spring 13, and in the exemplary embodiment of FIGS. 6-9, the compensation spring 18 is arranged on the driver stop 15 and lies between the stop surface 16 on the central stop 15 and the spring end 131 of the spring clip 13. In both cases the

Bias of the compensation spring 18 is set so that it is ideally half as large as the bias of the clamp spring 13 in the emergency air position.

In the exemplary embodiments described here, the compensation spring 18 shown in perspective in an enlarged manner in FIG. 5 has a U-shaped spring bracket 19 with a long leg 191 and a short leg 192. Both legs 191, 192 are joined together in one piece via a cross piece 193 ". The long leg

191 is bent outwards at a distance from the transverse web 193, the bent leg portion forming a spring slat 20 which is between the stop surface 16 of the housing stop 14 (FIGS. 1-4) or the driver stop 15 (FIGS. 6-9) and the spring end 131 the clamp spring 13 lies with the clamping force directed against the spring end 131. The compensation spring 18 is placed on the housing stop 14 (FIGS. 1-4; or on the driver stop 15 (FIGS. 6-9)) in such a way that the short, rigid leg 192 on the stop surface 17 and the one below the knee point also lies rigid leg section 191 'of the long leg 191 on the of this turned-off stop plate 16 of the housing stop 14 (FIGS. 1-4) or of the driver stop 15 (FIGS. 6-9) preferably rests with contact pressure.

1 to 4 on the housing 10 and in the exemplary embodiment of FIGS. 6 to 9, the driver 12 each has a defined distance, seen in the direction of rotation, from the stop plate 16 of the housing stop 14 or the driver stop 15 a spring stop 22 or 23 is formed, against which the fire leaf 20 bears at or near its free end under pretension. The distance of the spring stop 22 or 23 from the stop surface 16 of the housing stop 14 or from the stop surface 16 of the driver stop 15 also gives the range of

Mobility of the spring leaf 20, that is, the spring travel of the spring leaf 20 before. For play compensation, it is essential that the width of the axial web seen in the direction of rotation, the stop 1 ^ DZ not supporting the compensation spring lc. 15 forms, is at least equal to or somewhat larger than the width of the axial web 20 which forms the other stop 15 or 14 and which bears the compensation spring 18 and which takes into account the permitted tolerances for the axial web side.

In the emergency air position - as already mentioned - both stops 14, 15 ..n Radialπchtung one above the other, and the clamp spring 13 over their respective two abutment surfaces 16 on one side and both abutment surfaces 17 a _^ f the other side of the Mitrenmeranscnlags 15 and the Housing dates 14 overlapping spring ends 131 and 132, the driver 12 on the housing 10. At the same time, the compensation spring 18 presses with its spring leaf 20 against the clamp spring 13 and also generates a pretensioning force, so that the driver 12 is pretensioned in both directions and none

Backlash of the driver 12 m of the emergency air position can occur. In the region defined by the distance of the spring stop 22 or 23 from the housing stop 14 or the driver stop 15, the range of mobility of the spring plate 20 is only about half the torque required to deflect the driver 12 than the moment required to deflect the clamp spring 13 ,

The perspective view of FIG. 6 with the housing removed and FIGS. 7-9 with the same cutting guides as FIG. 2

1-4 modified reset device for the throttle valve 26 has been modified compared to the reset device according to FIGS. 1-4 in addition to what has already been described insofar as differently in the reset device according to FIGS. 1-4 the housing stop 14 is not with a larger one but with a smaller radial distance from the housing axis 10 is arranged than the driver stop 15 from the throttle valve shaft 11, so that m the emergency air position of the driver stop 15 is seen m above the radial direction of the housing stop 14 in the radial direction.

6 is for better illustration of FIG. 7

- 9 reset device shown the assembly of driver 12, throttle shaft 11 with rotatably seated throttle valve 26 and clip spring 13 dreidimer sionai shown. The as from the driver 12th protruding axial web formed driver stop 15 carries the compensation spring 18, the spring leaf 20 of which lies between the spring end 131 of the clamp spring 13 and the stop surface 16 on the driver stop 15. The spring leaf 20 is supported near its free end on the spring stop 23 fixed on the driver 12. The rigid, short leg 192 of the compensation spring 18 designed as a U-shaped spring bracket 19 lies on the stop surface 17 and the one present between the spring leaf 20 and the transverse leg 193 of the spring nut 19

Leg section 191 'is in each case non-positively on the stop ^plate 16 of the driver stop 15.

The mode of operation of the compensation spring 18 arranged on the driver stop 15 for causing the driver to be free from play 12 m of the emergency air position is as described above.

The mode of operation of the compensation spring 18 can be read well from the diagram shown in FIG. 10. There is the moment veriaαf M of the reset device on the

Throttle valve 26 m as a function of the angle of rotation α of the throttle valve shaft 11 in the area of small angle of rotation around the emergency air point 0 °. The strongly drawn characteristic curve 24 represents the torque curve with maximum play between the stops 14, 15, which results from the greatest width of the axial web forming the housing stop 14 and the smallest width of the axial web forming the driving stop 15, or vice versa, due to tolerance, m direction of rotation. The weakly drawn characteristic curve 25 represents the torque curve with minimal play of the stops 14, 15 represents that results in the smallest tolerances between the stops 14, 15. Without the compensation spring 18 there would be no torque in the rotation angle range b around the emergency air point 0 °, so that the throttle valve 26 flutters and an exact control of the

Internal combustion engine is not possible. As a result of the pretension applied by the compensation spring 18 to the clamp spring 13, a torque acts on the throttle valve 26 in this area, and regulation is possible in the swivel area b.

Claims

claims

1. Device for resetting a throttle valve (26) for the combustion air control of an internal combustion engine m a defined emergency air position, with a

Throttle valve (26) carrying, in a housing (10) rotatably mounted throttle valve shaft (11), with a rotatably seated on the throttle valve shaft (11, drivable driver (12) and with a preloaded clamp spring (13), the spring ends

(131, 132) by simultaneously clasping a housing stop (14) fixed to the housing (10) and a driver stop (15 'fixed to the driver (12) on mutually facing stop actuators (16, 17) of the stops (14, 15) the emergency air position of the Fix throttle valve (26), off which the throttle valve (26) can be adjusted by rotating the driver (12), characterized in that a compensation spring () between a spring end (131) of the clamp spring (13) and a stop surface (16) on one of the two stops (14, 15) 18) is arranged with a biasing force opposing the spring force of the clamp spring (13).

2. Device according to claim 1, d a d u r c h g e k e n n z e i c h n e t that each as the housing (10) or driver

(12) projecting axial webs formed stops (14, 15) are arranged radially offset from each other and at least over the axial width of the clamp spring designed as a cylindrical helical torsion spring, arranged coaxially to the throttle valve shaft (11)

(13) extend that the stop compartments (16, 17) are formed on the sides of the axial webs which face away from one another and face the direction of rotation, and that the spring ends (131, 132) of the clamp spring (13), which are directed inward toward the throttle valve (11), each protrude beyond the stop faces (16 or 17) on the same side of the axial webs.

3. Vorπcntung according to claim 1 or 2, d a d u r c h g e k e n n z e i c h n e t, oaß the compensation spring (18) is arranged on one of the stops (14, 15) and one of the stop surface

(16) αes stop (14, 15) upstream spring leaf (20j, which at one leaf end on Stop (14, 15) is fixed and bears at or near its other, free sheet end under pretension against a spring flange (22, 33) arranged at a distance from the stop surface (16) and defining the spring travel of the spring leaf (20).

4. The device according to claim 3, characterized in that the compensation spring (18) has a U-shaped curved spring clip (19) with a long and a short bow leg (191, 192) which are connected by a crossbar (193) that the long bow legs are bent outwards at a distance from the crosspiece (193) and that the bent bow leg section (191 ') forms the spring leaf (20).

5. The device according to claim 4, characterized in that the compensation spring (18) is placed on the stop (14, 15) so that the short bow leg (192) and below the kink point, the crossbar (193) sicn adjoining bow leg section (191 '), preferably non-positively, rest on the abutting surfaces (16, 17) of the stop (14, 15).

6. Device according to one of claims 3-5, characterized in that the compensation spring (18) is arranged on the housing stop (15) and the spring stop (22) for the spring leaf (20) is formed on the housing (10).

7. Device according to one of claims 3 - 5 d a d u r c h g e k e n n z e i c h n e t that the compensation spring (18) on the

Driver stop (15) arranged and the spring stop (22) for the spring leaf (20) is formed on the driver (12).

8. Device according to one of claims 1-7, that the pretensioning force of the spring leaf (20) of the compensation spring (18) is dimensioned half as large as the pretensioning force of the clamp spring (13) of the emergency air position of the throttle valve body (11).