DE3106088A1 - Steering booster arrangement - Google Patents

Abstract

A steering booster arrangement with a steering shaft which is divided into an upper and lower shaft and parts of which are connected by means of a torsion element between the upper and lower shaft and limit stops in order to limit a relative rotation between them, have a steering booster signal generating unit (5) with a signal generator (8), which is coupled in contactless fashion to the signal generators (16,17), for the servo motor (9). The steering booster signal generating unit (5) consists of a photo-optical signal generator with photodiodes (21) and phototransistors (22) as well as rotational shutters which are arranged in the latter as signal generators (16,17). Here, in each case two concentric rings (26,27) of slots (28 to 31) are arranged in the rotational shutters and several pairs (34 to 37) of phototransistors and photodiodes are provided for each ring (26,27). <IMAGE>

Description

Power steering arrangement

The invention relates to a power steering arrangement with a Steering shaft divided into upper and lower shaft, the parts of which by a torsion element between upper and lower shaft and End stops for limiting relative rotation are connected to one another and can be moved to one another without contact Have signal generator of a power steering transmitter for controlling a servo motor for the lower shaft. - ""

Such steering assistance arrangements are known as steering assistance on vehicles so that a manual steering wheel can be actuated Driver does not have to apply the entire steering force. It is known to increase the manual steering force by means of a power steering arrangement to be supported by an electric motor or hydraulically.

Eirie power steering arrangement of the type mentioned is known from DE-AS 26 58 679. This well-known version The purpose of this is to create a torque measuring device that is easy to maintain and easy to produce. The torsion element consists of one between the

Parts of the steering shaft arranged elastic huffe, at? - v / eise g : ^r . Gumni or a corresponding material. Dier = - "socket is ¹ , a" Di aj -: - pin mounted on one part of the central pivot shaft, which protrudes into openings in the other part of the central pivot shaft with clearance to the pin cross-section. Di: -. · Auslest? The from ir ■ torsion element also includes other designs with the same effects.

In the known version, as a touch ?; free v.ev. "?""bare signal generator to the tyellenteil ^ one hand ei" permanent magnet in the radial direction and on the other hand, a Bi "-ferential-field plate sensor arranged in spannunnrsfr he La ¹ Depending on the sleeve renau opposed to each other. In a Jielativ-twist under Yerspannunfc the sleeve a;.: '. I is generated, which via a connection of the differential - ^] third-Pühler in the form of a with several turns wn the ~ v - ordreter V.'ellentei] gev; icke ] .th conductor strip led away v / ir -.:. Such a conductor strip has the disadvantage of a mechanical: connection between a rotating part and. a rigid part, so that in operation, especially after prolonged material fatigue, and susceptibility to breakage occurs " ¹ "x Even the Materialerr ^{r i;?} idun can impair en o '·" falsification lead a Gignalgabe.

The same applies to when they can be moved to one another without contact nal generators in the form of a toothed ring out magnetic: - "" " rial on the one hand and an inductive sensor on the other the DE - OS 26 59 4-37 known, a signal via a Lei doorway Discharge control circuit. In this case, too, the problem of the arrangement on rotating parts compliance with longer periods of operation.

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DE-OS 14 80 205 shows an auxiliary-assisted steering device with hydraulic control using a measuring pump. Such a design is complex, apart from that when the manual steering wheel is connected to a steering shaft only by a hydraulic linkage, they do not offers sufficient security for a hydraulic failure.

In the case of an electric power steering arrangement, there is also one Known signal pick-up via slip rings. This is also considered to be disadvantageous due to the quasi mechanical connection, because Changes in the contact resistance depending on the operating time can occur, apart from the fact that disturbances cannot be ruled out due to contamination and are considerable Costs occur.

In steering assistance arrangements, it is taken into account that in an emergency a manual steering must be reserved, in this case for the full lock of the steering wheels of a vehicle to the left or right a deflection of the hand steering wheel by more than 180 ° is necessary, because otherwise it would be too direct Steering would be available and, furthermore, the steering forces no longer have to be applied because the reduction ratio is too small. Measured on this rash, which also occurs in practice when the power steering arrangement is used, to ensure reliable vehicle guidance To ensure that the above-mentioned deficiencies in mechanical connections are particularly serious. It is also take into account that certain functional parts are to be supported resiliently especially in vehicles, so that their mutual alignment can change within limits. In the case of a mechanical connection, possibly also by means of a wrapping tape, The resulting displacements or vibrations can have extremely detrimental effects even to a very small extent.

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The ι · - ¹ "" ¹ Zd ¹ Jn? ' is based on the task of improving an I-ßnkhilfe - / - r._ i ordmn: · "■■;: · e inn τη'rr; -Hotors for dit; Undersave, also over longer periods of operation, always know safely and independently of the above influences or also contaminated transmission.

According to the invention, this object is achieved in that the power steering sensor is non-contacting with the signal generators having coupled signal transmitter for the servo motor. By This contact-free transition is over practically unlimited operating times, independent of external influences flawless transmission guaranteed.

Kit special. Advantage consists of a photo-optical signal generator with photodiodes and phototransistor? "As well as in this as an 8ip; n al generator arranged. Because the power steering sensor is concentrated on a small one and is also largely encapsulated, perfect transmission is possible under all operating conditions ^{Bte 1} 'edges executed in the circumferential directions. However, it is particularly preferred that the three-face panels consist of identical slotted disks, which are evenly subdivided in the radial direction into adjacent ochlitr and web sectors, which extend at ausp; erio ^{> 1} '"-'"' ter upper and lower shaft cover. Apart from the fact that ^pr ~ point of S Slotted disks also disk sectors can be arranged in a limited V / inke.lberei whether vas einbor.c ™? ^ is, νηά that then only arranged in a simple number

are arranged in connection with at least one j'otodiode-hototransistor pair, the preferred configuration is a disk-shaped one! Forming the Drehblend.en in radially-symmetric same design to the extent 'iierbei the preferred Aunf ^ guide shape that two concentric Fränze of slots ¹ ^ in' any windshield -.. Are reordnet This provides in a simple manner the possible answer a Directional signal size depending on the direction of the peep rotation between the shaft parts. In this context, it is particularly preferred that the slots arranged in a slot sector are made narrower in the circumferential direction than the sector width and each γαι different edges of the slot sectors are offset from one another.

Apart from the above mentioned and. included execution are according to the particularly preferred solution according to or multiple pairs of photo-transistors and photodiodes are provided for each ring in the ring arrangements of slots. Through this not only will the signal transmission due to increased intensity, also avoiding interference at minor Failures achieved, but it also becomes the prerequisite for an improved resolving power in signaling and thus created for a more sensitive response. Under from this point of view are useful with regard to a ring arrangement different pitches are provided by slots and photodiode-phototransistor pairs. Here is a preferred Aias leading form regarding the divisions one and one greater number of slots than photodiode-phototransistor pairs with respect to one or each. TTranzes provided.

In the following, the irfi-.dung is based on an exemplary embodiment explained, which is shown in the drawing. Ir. the Drawing show:

BATH ORIGiWAL

3 1 O 6 O 8 "δ

- he -

Q-

-I ¹ Ir- 1 o a basic soheroatic view of a power steering arrangement,

Fig. 2 is a partial representation; sun Figure 1 enlarged Γ-iaßstnb to explain a preferred Embodiment of --irfindunr,

3 is a view from FIG . corresponding to the line III - III in Figure 2.

According to FIG. 1, a steering shaft 1 with a ^{1 hand} steering wheel 2 at the free end is divided into an upper shaft 3 and a lower shaft 4, which are coupled to one another in a restricted manner by a power steering encoder 5. The TJnterwelle 4 is connected via a steering gear 6 with at least one steerable wheel 7: '

The steering aid 5 is assigned a Sirmnlp: Eber 8 for a rjervo-Mοtor 9, for example via a drive wheel and a drive chain 11 a drive wheel !. 12 the lower ^{wave r} - ■ 'drives. Between the steering aid transmitter 5 and the signal transmitter there is a connection connection 13 which, in known designs, contains a mechanical connection in which the steering aid arrangement described, however, provides for a contact-free transmission.

The upper shaft 3 'and the Uriterwelle'! · Are in accordance with Figure 2 duroplastic ¹ 'Uorsionselement 14 connected in the form of a resilient in Umfanrrrichtung i-.uffe, on the one hand to an n-pin 1f of the Unterv / 4 and elle. on the other hand, is fixed in a sleeve-shaped i'nd of the harmonic 3. Further attacks to limit the scope. ^;; ßigon deflection · 'are started v.r'd not shown in detail (DE-AS 26 58 679).

According to FIG. 2, the power steering sensor 5 contains we ^ lc.hlit zcc ^ eiben 16, 17, each of which is arranged on the facing earth of the upper ^{shaft 3 ljn (} i of the lower shaft 4- parallel to one another and opposite one another. Serve

are over an essential '!' part of their

fargn, for example, bordered above 180 °, of a photo element holder Ί 18, which is outside the plane formed by the two split washers 16, 17 assembly in two of these enclosing ■ '■ arms 19, 20 pairs of mutually associated photodiodes 21 and J

Having phototransistors 22. These grasp the Schiitzscheiber- π

- I:.: Contact-free and deliver depending on a light passage ^ n ^, ij ^:

Via a functional connection 23 (FIG. 1) between the Sir-: j; nalgeber 8 and the servo motor 9 drive signals.

The structure of a protective disk 17 can be seen from FIG. ^{It can be seen that this consists of slot sectors 2 Ü} · and Sterselvtoren ? 3 · arranged in the radial direction and adjacent in the circumferential direction. These suitably have the same width. Both slotted disks are assigned to one another in the starting position with the sleeve 14 relaxed so that a web sector of a protective disk 16 is in front of an öchlitzsector of another slotted disk I? is arranged. In the rest position, no light is allowed to pass through and no signal is emitted with the phototransistor 22 when the phototransistor 22 is activated. The excitation circuit is not shown in detail. It contains an energy source and Schaltunτ elements. With a relative rotation between upper shaft 3 and lower shaft 4, the covering of the slots in the slotted disks is increasingly removed and a signal is delivered.

The preferred embodiment, which is also shown in FIG. 3 ir.t, each slotted disc has two concentric rings 26, 27 of slots 28, 29 and 30, 3I, respectively. It is preferred; + +, that these slits or windows in circumferential tunnels narrow fir.- ' than the width of one slot sector 24. As shown

the slots 30, 31 of a slot ring 27 on one edge of the slot sectors and the slots 28, 29 of the other ring 2 ^s - offset to the other edge of the jet / urgent slot sector.

Correspondingly, the potentiometer holder 18 has in two circular segment-shaped arrangements 32, 33 photodiode-phototransistor pairs 3 ^ j 35, 36, 37 assigned to a ring of the slots. As a result, in the case of the relative rotation between upper shaft 3 and lower shaft H at the various rings, signals are given with increasing strength with increasing relative rotation when deflected in different directions. In this way, various function channels in the function connection 13 can be controlled, which conduct a direction-oriented signaling.

In relation to the circumference around the axis of the steering shaft -

j a different division between the slot and web sector \ on the one hand and the respectively assigned photodiode-photo transistor, stor-pairs 3 ¹ J to 37 on the other hand, so that the on- ■

solvency is increased. ;

If from the basic position on the hand steering wheel 2, a steering torque on I is brought, there is an angular deviation between upper shaft 3 and lower shaft: 4

cL = c * M _H

where M “is the steering torque on the hand steering wheel and c is the torsion constant the socket 14 sin-d.

The slot web sector overlaps open accordingly, so that light can pass between the photodiodes 21 and phototransistors 22. The intensity of the light increases proportionally to the angle oL , so that a signal proportional to this angle is generated. In the signal generator 8 this "ses signal is converted into a variable for controlling the servo motor 9, which rotates the lower shaft H until the angle ⁰ ^

Tiif η 7 · ¹ 'ΐ "" ϊοΊ · τ <\ ΘfϋΤιTt int. This pi-lt accordingly for' bei ' ¹ η n-po! _{ir (-i.} rhunnon ic ^{r /} - \ ir, nm'nen ¹⁾ n-nr "mi t the verr.chicdonen 'Ί: ^Ύ \?.' / ηη 2 · ^f -, P / ^7, wherein.. automatically by different ΡυΓ. '^ χοΓ.ρ ^ πη?': e the Orearichtunn; des oervo-Iiotors ^c : "is determined. In an advantageous embodiment. r.chlitsBe ^ toren ? Λ for so oil · · ε rotodiori.en-j'o Pπ are vorr-eεQhen.

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Claims (1)

Claims Power steering arrangement with a steering shaft divided into upper and lower shafts, the parts of which are supported by a torsion element connected between upper and lower shaft and end stops to limit relative rotation against each other are and contactlessly movable signal generators of a power steering transmitter for controlling a servo motor for the lower shaft, characterized in that the power steering sensor (5) has a contact-free with the signal generators (16, 17) coupled signal transmitter (8) for the servo motor (9). 2, arrangement according to claim 1, characterized in that the power steering encoder (5) from a photo-optical signal, encoder with photodiodes (21) and phototransistors (22) and in this as a signal generator (16, 17) arranged rotary diaphragms, one of which is in each case on the harmonic (3.) or the lower shaft (4) is arranged. Arrangement according to claim 2, characterized in that the original panels made of identical slotted disks (16, 17) exist, which in the radial 'direction evenly divided into neighboring slot sectors (24 ·) and web sectors (25) which are aligned with the upper and lower parts Cover (3, ^). 4-. The assembly of claim 3, d '^> ^ n ch e each slit disk (16, 17): ---.-: oi "xv zr ^---;; rär.cae knurled ^ ^ e (26; 2.?! ?) of slots (28 to 31) arranged -ind. 5. Arrangement according to A.nspruch 4-, characterized in that aio in a slot sector (24-) arranged slots (23 to 31) in tfmfangsrichtung narrower than the sector width and .jev; eils to different Pnr.dern the Schiit: sectors are offset from one another. 6. toordnunp; according to one of claims 2 to?, characterized in that according to the zrp ^ .zcr.orders (26, 27) of slots (28 to 3I) "obrerer .. eeve (3 ^z i- to 37) sus photo transistors and Photodiodes are provided for each ΤΡΠ7, (26, 27). '·. Arrangement according to claim ^r "·, characterized in that with respect to a ring arrangement (26, 27) of slots (28 to 31) and photodiode-pototransistor pairs (34-, 37) different ^r divisions are provided. S. Arrangement according to claim 7, characterized in that with respect to of the divisions a υπ one greater number of. Slits (28 to 31) as photodiode-.pototransistor pairs (34-37) with respect to one or each wreath (26, 27). is provided. "" Z _β 9. The arrangement of claims 3 to 8, characterized in ₅ that the pivot aperture of slotted disks and sectors exist in a limited angular range for a.