CN101428639A - Electric power steering device - Google Patents

Abstract

An electric power steering device is configured to transmit an auxiliary torque to a steering unit of front wheels, and includes: a steering wheel (operator); an electric motor configured to generate the auxiliary torque in accordance with at least a steering torque generated by input from the operator; the steering unit of front wheels which includes a pinion shaft; and a rotation terminating mechanism which provides a motion terminating end of the operator, the rotation terminating mechanism being disposed between the steering wheel and the pinion shaft.

Description

Driven steering device

Technical field

The present invention relates to give driven steering device based on the steering auxiliary force of electrical motor to the power steering system of vehicles such as automobile.

Background technology

Driven steering device makes the assist torque of electrical motor generation according to the size of handling torque, and assist torque to the steering system transmission, is alleviated the actuating force that steerman is handled.

In common driven steering device, for stoping the necessarily above handling maneuver of using wheel that turns to, therefore, at rack shaft the tooth bar end is set, in the tooth bar housing section of accommodating rack shaft shell end is set, the tooth bar end item that utilization is terminal by this tooth bar and shell end constitutes, steering handwheel is handled respectively to the angle of regulation to the left and right from center position, thereby turn to handling maneuver angle with wheel arrive maximum handling maneuver angle (below, be called the tooth bar terminal angular) situation under, about in the tooth bar end item of a side, the terminal and shell end butt of tooth bar, thus can not turn to the usefulness wheel to the further handling maneuver of equidirectional.

Therefore,, apply big manipulation torque, reach under the situation of tooth bar terminal angular, can not turn to and handle with wheel steering to steering handwheel though steering handwheel is handled till near the tooth bar terminal angular, therefore, the manipulation torque that the steerman input is bigger.Handle torque in response to this, give big steering auxiliary force to steering system, may apply big impact to the tooth bar end item thus from electrical motor, or to Chi Tiao ﹠amp; Miniature gears applies big overload, or produces big impulsive sound, or the breakage of generation component parts or distortion etc.Also have, and then, the rotation function that the moment of inertia by electrical motor causes, the rotation generation excess of stroke of electrical motor also causes big impact or overload to act on component parts such as tooth bar thus, therefore, breakage or distortion etc. may take place.

As the device of avoiding such problem, disclosed structure in special fair 6-No. 4417 communiques is for example arranged.In the device of in special fair 6-No. 4417 communiques, putting down in writing, after the manipulation angle (operational ton) of steering handwheel reaches near the predetermined angular of tooth bar terminal angular, follow the increase at handling maneuver angle and reduce the target current value, when the handling maneuver angle reaches the tooth bar terminal angular, the target current value is made as zero, prevents that thus big impact from putting on the tooth bar end item.

Yet, in the device of in special fair 6-No. 4417 communiques, putting down in writing, steering handwheel is switching under the situation about returning near the tooth bar terminal angular round about, during before the handling maneuver angle becomes below the predetermined angular, the limited target current value, therefore, can not will give and steering system with the corresponding enough steering auxiliary forces of manipulation torque, it is heavy that thereby steering handwheel becomes, the tooth bar terminal angular of the essence that steerman can be operated diminishes, and causes steering handwheel to be switched to mechanically the problem till the tooth bar terminal angular that is provided with.

As its countermeasure, open in the device of record in 2006-No. 248252 communiques (with reference to paragraph [0038], [0047]) the spy, near the tooth bar terminal angular handling maneuver angle is θ more than 1, and motor speed ω M is under the situation of setting value ω more than 1, reduces the gain that turns to torque value T.

In addition, only more than near the manipulation angle (operational ton) the tooth bar terminal angular, and switch the gain that increases the motor angle velocity feedback when increasing.

Yet, open in the technology of 2006-No. 248252 communiques the spy, during the shell end butt of and housing terminal at the tooth bar of a side's of left and right sides rack shaft, if further reversing steering handwheel, steerman increases operation, then torque sensor detects the manipulation torque, switch the increase direction at electronic type and produce assist torque, to the tooth bar end and the shell end of butt apply stronger power.In addition, can not eliminate following problem, that is: the absolute value of rotational speed omega is less than setting value | during ω 1|, or with under fast motor speed ω and the terminal situation of colliding of tooth bar, because the kinetic energy that the moment of inertia of electrical motor causes causes the rotation generation excess of stroke of electrical motor, produce big impact or overladen problem at component parts such as tooth bars.Therefore, for even the state of and shell end butt terminal with tooth bar further increases steering operation, also, need to increase the intensity of electrical motor or speed reduction gearing (gear on worm, worm-gear toothing) or tooth bar or miniature gears or bearing or housing etc. not owing to its load causes generation problem on the integrity of machinery of power steering system.In addition, overload puts on electrical motor, may cause blowing.

Summary of the invention

Therefore, the object of the invention is to provide a kind of and does not make overload effect (inhibit function) in Chi Tiao ﹠amp; Under the situation of miniature gears, restriction is assisted near the tooth bar end, and, the driven steering device that impact is not had an effect.

In one aspect of the invention, provide a kind of driven steering device, it possesses: operating parts; At least basis is by the electrical motor that produces assist torque from the manipulation torque that input produced of described operating parts; The steering system that possesses the front-wheel of pinion shaft, described driven steering device is with the steering system transmission of described assist torque to described front-wheel, it is characterized in that, be provided with rotation terminal mechanism between described operating parts and pinion shaft, this rotation terminating machine is configured to the action terminal of described operating parts.

In addition, in above-mentioned driven steering device, it is characterized in that preferably that rotation terminal mechanism has speed reduction gearing, the rotary manipulation scope of allowing by the operating parts of action terminal limitations is changed.

According to this structure as can be known, what rotation terminal mechanism can utilize that speed reduction gearing comes alter operation spare allows the rotary manipulation scope, therefore, can to steerman give with identical in the past steering handwheel (operating parts) in about manipulation angle (operational ton) scope.

And then preferably in above-mentioned driven steering device, it is characterized in that also possessing: detect the torque sensor of described manipulation torque, described rotation terminal mechanism is arranged between described operating parts and the described torque sensor.

According to this driven steering device as can be known, when operating parts reaches the action terminal, the further operation that rotation terminal mechanism stops operating parts to cause in the action terminal, therefore, torque sensor can not detect the signal of the assist torque that the further electrical motor of generation causes on the direction of its prevention.And then, even the excess of stroke takes place in the rotation of electrical motor, also can act on the direction of the detection torque minimizing that makes the torque sensor detection.

And then, preferably in above-mentioned driven steering device, it is characterized in that, also possess: the torque sensor that detects described manipulation torque, the steering system of described front-wheel also possesses the assist torque transmission mechanism, and described rotation terminal mechanism is arranged between described torque sensor and the assist torque transmission mechanism.

According to this driven steering device as can be known, when operating parts reaches the action terminal, the further rotary manipulation that rotation terminal mechanism not only stops operating parts to cause in the action terminal, also stop with respect to torque sensor and (for example be arranged at the assist torque transmission mechanism, speed reduction gearing and then specifically, worm-gear toothing) side, and the rotation of the pinion shaft that together rotates with the assist torque transmission mechanism.If can stop the rotation of pinion shaft, the overload of the rotation of following the pinion shaft (worm gear) that transmits assist torque is not acted on have the miniature gears that on pinion shaft, is provided with and with the Chi Tiao ﹠amp of the tooth bar of this pinion; Miniature gears.In addition, the deflection angle the during rotation of prevention pinion shaft becomes the tooth bar terminal angular, can limit near the assisting of tooth bar end.

In addition, even the rotation generation excess of stroke of operating parts and then electrical motor, rotation terminal mechanism also can stop the rotation of pinion shaft, and therefore, the rotation that the excess of stroke causes is not to tooth bar; Miniature gears transmits, and can not make overload have an effect (inhibit function).

In addition, preferred described rotation terminal mechanism comprises: have the input shaft of external gear, it is transmitted the rotation from the S. A. of described operating parts; Belt gear, it has the external gear ingear inner gear with described input shaft, and is provided with first protrusion at outer circumferential side; The ring-type fixed part, it surrounds described Ring gear, the external gear of described input shaft and the inner gear of described Ring gear constitute described speed reduction gearing, are provided with second protrusion that limits the rotation of described first protrusion with the described first protrusion butt in interior all sides of described fixed part.

In this rotation terminal mechanism, by the external gear of input shaft and the inner gear of Ring gear, the anglec of rotation with respect to input shaft, can reduce the anglec of rotation of Ring gear, therefore, can to steerman give with identical in the past steering handwheel (operating parts) about the scope at manipulation angle (operational ton).And then, only by changing Ring gear, can change the operational ton with the cooresponding steering handwheel of tooth bar terminal angular, can tackle various car types.

In addition, preferred described rotation terminal mechanism comprises: as the planet-gear speed reducer unit of described speed reduction gearing, it possesses outer ring gear, (a plurality of) planetary wheel, pinion carrier and sun gear; Fixed part, its fixing described outer ring gear, be provided with first protrusion at described planetary wheel, to described sun gear transmission, be provided with second protrusion that limits the rotation of described first protrusion with the described first protrusion butt from the rotation of the S. A. of described operating parts at described fixed part or described outer ring gear.

In this rotation terminal mechanism, by planetary gear reduction unit,, can reduce the anglec of rotation of pinion carrier with respect to the anglec of rotation of sun gear, therefore, can to steerman give with identical in the past steering handwheel (operating parts) about the scope at manipulation angle (operational ton).And then, can be configured to the rotating shaft coaxle with operating parts, can carry the good rotation terminal mechanism of balance, and, when first protrusion and the second protrusion butt, put on each planetary load and bear by pinion carrier, can stand bigger load.Thereby correspondingly terminal mechanism is rotated in miniaturization.

In addition, preferred described rotation terminal mechanism comprises: have the threaded portion of external screw thread, it is transmitted the rotation from the S. A. of described operating parts; Ring-type first hill holder, it is fixed in described threaded portion, and is provided with first protrusion at outer circumferential side; Second hill holder, it has and described threaded portion ingear negative thread, is disposed at the top of described first hill holder, is provided with second protrusion with the described first protrusion butt in its lower face side; The 3rd hill holder, it has and described threaded portion ingear negative thread, is disposed at the below of described first hill holder, and face side is provided with the 3rd protrusion with the described first protrusion butt thereon; Guide member, it stops the rotation of described first and second hill holder, make described second and third hill holder along the moving axially of described threaded portion, described threaded portion, described second hill holder, described the 3rd hill holder and described guide member constitute described speed reduction gearing.

In this rotation terminal mechanism, the rotation of threaded portion is converted to moving up and down of second and third hill holder, it is big that the anglec of rotation of the threaded portion till the 3rd protrusion butt of first protrusion of first hill holder and second protrusion of second hill holder or the 3rd hill holder becomes, therefore, can to steerman give with identical in the past steering handwheel (operating parts) about manipulation angle (operational ton) scope.

And then, in this rotation terminal mechanism, manipulation angle about in the steering handwheel can be increased and for example set, two circles above (more than 720 °), can also be applicable to automobile vehicle in addition, and, because do not have gear, so can reduce to constitute the external diameter of rotation terminal mechanism, can further improve lift-launch to vehicle.

Description of drawings

Fig. 1 is the constructional drawing of the driven steering device of first embodiment of the present invention.

Fig. 2 is the torque sensor of the power steering gear case among Fig. 1 and near the lateral plan the miniature gears.

Fig. 3 is the detailed constructional drawing of torque sensor, is that A-A among Fig. 2 is to pseudosection.

Fig. 4 is the figure that explanation has applied the displacement of top float portion, bottom float portion and slide block under the state of handling torque, (a) be the figure of expression neutral condition, (b) being that expression is applied with the figure that the state of torque is handled on a left side, (c) is that expression is applied with the right figure that handles the state of torque.

Fig. 5 is explanation from voltage output signal VT1, the VT2 of torque sensor and is detected the chart of voltage (dtc signal) VT3 by the torque that differential amplifier circuit amplifies.

Fig. 6 is the schematic top plan view of the rotation terminal mechanism of first embodiment, (a) be the expression steering handwheel with respect to about be positioned at the figure of the situation of center position, (b) being the figure of the left operation state (state of [left tooth bar end]) made of expression, (c) is the figure of the right operation state (state of [right tooth bar end]) made of expression.

Fig. 7 is a functional block diagram of handling control ECU.

Fig. 8 A is expression to the data sheet as the relation of the basic signal of the dtc signal output of the input of basic signal operation portion.

Fig. 8 B is expression to the data sheet as the relation of the compensating signal of the rotating speed output of the electrical motor of the input of energy disperser compensating signal operational part.

Fig. 9 A is the chart of time lapse of the operational ton of expression steering handwheel.

Fig. 9 B is the chart of expression from the time lapse of the dtc signal VT3 of torque sensor output.

Fig. 9 C is the chart of time lapse of variation at the manipulation angle of the actual front-wheel of expression.

Figure 10 is the schematic top plan view of rotation terminal mechanism of first variation of first embodiment, (a) be the expression steering handwheel with respect to about be positioned at the figure of the situation of center position, (b) being the figure of the left operation state (state of [left tooth bar end]) made of expression, (c) is the figure of the right operation state (state of [right tooth bar end]) made of expression.

Figure 11 has been to use the schematic perspective view of rotation terminal mechanism of second variation of first embodiment of planetary gear reduction unit.

Figure 12 is the schematic top plan view of rotation terminal mechanism of the 3rd variation of first embodiment, (a) be steering handwheel with respect to about be positioned at the figure of the situation of center position, (b) being the figure of the left operation state (state of [left tooth bar end]) made of expression, (c) is the figure of the right operation state (state of [right tooth bar end]) made of expression.

Figure 13 is the block diagram of rotation terminal mechanism of individually representing to constitute the 3rd variation of first embodiment.

Figure 13 A is a profile block diagram of going up hill holder.

Figure 13 B is the profile block diagram that is fixed in the rotary actuator of threaded portion.

Figure 13 C is the profile block diagram of following hill holder.

Figure 13 D is the profile block diagram of guide member.

Figure 14 is the constructional drawing of the driven steering device of second embodiment of the present invention.

Figure 15 is the constructional drawing of the driven steering device of the 3rd embodiment of the present invention.

Figure 16 is the constructional drawing of the driven steering device of the 4th embodiment of the present invention.

Figure 17 is the torque sensor of the power steering gear case among Figure 16 and near the lateral plan the miniature gears.

Figure 18 is the figure that explanation has applied the displacement of top float portion, bottom float portion and slide block under the state of handling torque, (a) be the figure of expression neutral condition, (b) being that expression is applied with the figure that the state of torque is handled on a left side, (c) is that expression is applied with the right figure that handles the state of torque.

Figure 19 is the schematic top plan view of the rotation terminal mechanism of the 4th embodiment, (a) be steering handwheel with respect to about be positioned at the figure of the situation of center position, (b) being the figure of the left operation state (state of [left tooth bar end]) made of expression, (c) is the figure of the right operation state (state of [right tooth bar end]) made of expression.

Figure 20 A is the chart of time lapse of the operational ton of expression steering handwheel.

Figure 20 B is the variation at manipulation angle of the angle of rotation of overlapping electrical motor and front-wheel and the chart represented.

Figure 21 is the schematic top plan view of rotation terminal mechanism of first variation of the 4th embodiment, (a) be steering handwheel with respect to about be positioned at the figure of the situation of center position, (b) being the figure of the left operation state (state of [left tooth bar end]) made of expression, (c) is the figure of the right operation state (state of [right tooth bar end]) made of expression.

Figure 22 has been to use the schematic perspective view of rotation terminal mechanism of second variation of the 4th embodiment of planetary gear reduction unit.

Figure 23 is the schematic top plan view of rotation terminal mechanism of the 3rd variation of the 4th embodiment, (a) be steering handwheel with respect to about be positioned at the figure of the situation of center position, (b) being the figure of the left operation state (state of [left tooth bar end]) made of expression, (c) is the figure of the right operation state (state of [right tooth bar end]) made of expression.

Figure 24 is the block diagram of rotation terminal mechanism of individually representing to constitute the 3rd variation of the 4th embodiment.

Figure 24 A is a profile block diagram of going up hill holder.

Figure 24 B is the profile block diagram that is fixed in the rotary actuator of threaded portion.

Figure 24 C is the profile block diagram of following hill holder.

Figure 24 D is the profile block diagram of guide member.

Figure 25 is the constructional drawing of the driven steering device of the 5th embodiment of the present invention.

The specific embodiment

" first embodiment "

In the time of referring to figs. 1 through Fig. 9 A～C, first embodiment of the present invention is described.

Fig. 1 is the constructional drawing of the driven steering device of first embodiment of the present invention.

Fig. 2 is the torque sensor of the steering box among Fig. 1 and near the lateral plan the miniature gears.

Driven steering device 100A as shown in Figure 1, utilize two Hooke's coupling 3b bindings to be provided with the steering-wheel spindle 3a of steering handwheel (operating parts) 3, axle 3c, input shaft 3d, input shaft 3d links via torsion bar 111 and pinion shaft 7, in addition, be arranged at the miniature gears 7a and the tooth bar 8a engagement that on the overall width direction, can come and go mobile rack shaft 8 of the bottom of pinion shaft 7, front- wheel 1L, 1R about the two ends of rack shaft 8 link via link rod 9,9.

As shown in Figure 2, rack shaft 8 utilizes rack guide 31 to push and can support slidingly and movingly on left and right directions to miniature gears 7a side with the opposition side from tooth bar 8a, and then by regulating bolt 32 application of forces tooth bar 8a is pressed on miniature gears 7a via compression spring 33.The 34th, the locking lock nut of regulating bolt 32.

Also have, as shown in Figure 1, from input shaft 3d through the pinion shaft 7 of torsion bar 111 via bearing 3e, 3f, 3g with its top, pars intermedia, lower support in power steering gear case 10A.

Be provided with tooth bar terminal 8b, 8b at the two ends of rack shaft 8.In addition, in described steering box 10A, the inside of accommodating the tooth bar housing section 11A of miniature gears 7a, rack shaft 8, bearing 3g is provided with and makes slide vertically freely plain bearing 14 of rack shaft 8, and then is provided with shell end 11a, 11a in left and right end portions.

But, these tooth bars terminal 8b, 8b and shell end 11a, 11a are provided with as be used to limit maximum handling maneuver angle (tooth bar terminal angular) in the past, only use for the mobile centralized positioning that is used to mark the rack shaft 8 when power steering gear case 10A assembled with single-piece.

Thereby, in the present embodiment, in the operational ton (manipulation angle) of the steering handwheel of making about the setting aftermentioned rotation terminal 6A of mechanism 3, limit maximum handling maneuver angle (tooth bar terminal angular), terminal 8b of the tooth bar of the location when being used to assemble and tooth bar housing 11a are set to have surplus, with butt not under maximum handling maneuver angle.

In all embodiments of following explanation and the rotation terminal mechanism of variation thereof (6,6A, 6B, 6B ', 6C, 6D, 6E, 6E ', 6F), " tooth bar terminal angular " is meant the maximum handling maneuver angle of rotation terminal mechanism regulation.

By this structure, driven steering device 100A can change the working direction of vehicle when the operation of steering handwheel 3.Also have, rack shaft 8, tooth bar 8a, link rod 9,9 constitute steering control mechanism.

In addition, driven steering device 100A possesses the electrical motor 4 that is used to alleviate based on the auxiliary steering force of the actuating force of steering handwheel 3, is arranged at worm-gear toothing (wormgear) 5a and gear on worm (worm wheel gear) the 5b engagement that is arranged at pinion shaft 7 of the output shaft of this electrical motor 4.

That is, constitute speed reduction gearing (assist torque transmission mechanism) 5A by worm-gear toothing 5a and gear on worm 5b.In addition, worm-gear toothing 5a, the gear on worm 5b by linking with the rotor of electrical motor 4 and electrical motor 4, pinion shaft 7, rack shaft 8, tooth bar 8a, link rod 9,9 etc. constitute steering system.

Electrical motor 4 is to comprise the stator (not shown) that possesses a plurality of excitation coils and at the three-phase brushless motor of the rotor (not shown) of the inner rotation of this stator, electric power is changed to mechanical power (PM=ω MTM).

At this, ω M is the cireular frequency of electrical motor 4, and TM is the generation torque of electrical motor 4.

At this, the manipulation torque that puts on steering handwheel 3 is made as Ts, will be made as AH via the auxiliary auxiliary quantity of the generation torque of the electrical motor 4 of speed reduction gearing reinforcement, the coefficient of auxiliary quantity AH for example is made as kA (VS) as the function of vehicle velocity V S.In this case, AH=kA (VS) * Ts, therefore, the miniature gears torque Tp that puts on pinion shaft 7 represents shown in (1).

Tp＝Ts+AH

＝Ts+kA(VS)×Ts ·······(1)

Thus, handling torque Ts represents shown in (2).

Ts＝Tp/(1+kA(VS)) ·······(2)

Thereby manipulation torque Ts alleviates the 1/{1+kA (VS) for miniature gears torque Tp (load) } doubly.For example, if when vehicle velocity V S=0km/h, kA (0)=2, then handle torque Ts and be controlled to be 1/3 of miniature gears torque Tp, when vehicle velocity V S=100km/h, kA (100)=0 then handles torque Ts and equates with miniature gears torque Tp, is controlled to be the effect sense that turns to the manipulation torque of the firm weight that equates with manual power.That is, torque Ts is handled in control according to vehicle velocity V S, gives slim and graceful stable manipulation torque thus when low speed driving, gives the effect sense of firm stable manipulation torque when running at high speed.

In addition, driven steering device 100A possesses: the motor drive circuit 23 of driving motor 4; Resolver 25; Detection puts on the torque sensor 110 of the miniature gears torque Tp of pinion shaft 7; Amplify the differential amplifier circuit 21 of the output of torque sensor 110; Detect the car speed sensor SV of the speed (speed of a motor vehicle) of vehicle; Be input into the manipulation control ECU (ElectricControl Unit) 200 of driving at the rotation terminal 6A of mechanism, control motor 4 of action of the steering handwheel 3 of torque sensor 110 in the tooth bar end limit.

Motor drive circuit 23 for example possesses a plurality of on-off elements of FET bridge circuit of three-phase and so on, uses from load (load U, supported V, the load W) signal of handling control ECU200 (with reference to Fig. 7), generates square-wave voltage, driving motor 4.

In addition, motor drive circuit 23 possesses the function of using not shown Hall element to detect three-phase motor electric current I (IU, IV, IW).

Resolver 25 detects the electrical motor angle of rotation θ m of electrical motors 4, and output angle signal θ for example, has and will detect the resolver that sensor that magnetoimpedance changes approaches circumferentially to be provided with the magnetic swivel of equally spaced a plurality of jogs.

Car speed sensor SV detects the pulse count of the speed of a motor vehicle as time per unit, and output vehicle speed signal VS.

(torque sensor)

Secondly, in the time of with reference to Fig. 2～Fig. 4, the structure of torque sensor is described.Fig. 3 is that A-A among Fig. 2 is to pseudosection.Fig. 4 is the figure that explanation has applied the displacement of top float portion, bottom float portion and slide block under the state of handling torque, (a) be the figure of expression neutral condition, (b) be that expression has applied left manipulation torque, pinion shaft 7 is with respect to the figure of input shaft 3d from the about 30 ° state of neutral condition left-hand rotation, (c) be that expression has applied right manipulation torque, pinion shaft 7 is with respect to the figure of input shaft 3d from the about 30 ° state of neutral condition right-hand turn.

Torque sensor 110 detects the size and Orientation of the manipulation torque Ts that puts on steering handwheel 3 (with reference to Fig. 1), and as shown in Figure 2, assemble integratedly with input shaft 3d, pinion shaft 7, and together be housed in the tooth bar housing section 11A portion by among flange bonded assembly lid (lid) 13A of portion with bearing 3e, 3f.

As shown in Figure 2, torque sensor 110 by bearing 3e, 3f and between input shaft 3d and pinion shaft 7 the not shown bearing of coaxial setting be supported to and can rotate relatively, and input shaft 3d utilizes torsion bar 111 to be connected with pinion shaft 7.Also have, torque sensor 110 comprises: the top float portion 112 of utilizing the lower end side of torsion bar 111 and pinion shaft 7 bonded assembly input shaft 3d; The bottom float portion 113 of the upper end side of pinion shaft 7; At the outer peripheral face separately of top float portion 112 and bottom float portion 113 fixing pin 117A, 117A, 117B, 117B (with reference to Fig. 3); Slide block 115; The first magnetic test coil 114A and the second magnetic test coil 114B.

As shown in Figure 3, top float portion 112 has opposed floating slice 112a, 112a.Bottom float portion 113 is for having the shape of the thick-wall cylindrical body of hollow bulb 113a at central part, the side of cylindrical body has: form thin-wall thin-walled week facial 113b, 113b in opposed side; Not facial 113c of outstanding week, the 113c of the remaining lateral parts of thin-wall.

So that the overlapping mode of radial outside of floating slice 112a and facial 113b of thin-walled week, combination top float portion 112 and bottom float portion 113.At this moment, between the inner peripheral surface of the outer peripheral face of facial 113b of thin-walled week and floating slice 112a, be formed with the gap, can rotate the relative rotation angle of regulation, for example ,-5 °～+ 5 °.For further rotation relatively, the circumferential end butt of the circumferential end of floating slice 112a and outstanding all facial 113c makes torsion bar 111 further not turn.

Also have, the diameter of the outer peripheral face of the facial 113c of outstanding week of the diameter of the outer peripheral face of the floating slice 112a of top float portion 112 and bottom float portion 113 is identical.Cover the slide block 115 of cylindrical body in the mobile mode of can sliding at the outer peripheral face of top float portion 112 and bottom float portion 113.On slide block 115, be equipped with pin 117A, 117A opposed to each other and insert logical the slotted hole 118A, the 118A that axially go up lengthwise, and opposed pin 117B, the 117B of being equipped with inserts logical oblique slotted hole 118B, 118B.Also have, pin 117A, 117A, 117B, 117B combination torsion bar 111, top float portion 112, bottom float portion 113, then, respectively by slotted hole 118A, 118A and oblique slotted hole 118B, 118B, insertion is arranged in the not shown described pin-and-hole of top float portion 112, bottom float portion 113, thus makeup torque sensor 110.

Slide block 115 is formed by the magnetic core material.Being fixed in the inner peripheral surface of cap 13A, and be disposed at two-layer up and down by the first magnetic test coil 114A, the second magnetic test coil 114B that conjugated material surrounds with the opposed mode of the outer peripheral face of slide block 115.

At this, pin 117A, 117A, 117B, 117B, slotted hole 118A, 118A, oblique slotted hole 118B, 118B constitute cam mechanism, if turn top float portion 112 and bottom float portion 113, then as shown in Figure 4, slide block 115 is guided by slotted hole 118A and oblique slotted hole 118B and moves down in the axial direction.

The variation that the displacement of the above-below direction of the slide block 115 that is formed by such magnetic substance core produces magnetic flux density at the first magnetic test coil 114A, second magnetic test coil 114B periphery, it is big that one side of the influence coefficient of the first magnetic test coil 114A and the second magnetic test coil 114B becomes, the opposing party changes respectively with diminishing, and the first magnetic test coil 114A and the second magnetic test coil 114B export torque shown in Figure 5 respectively and detect voltage VT1, VT2.

Torque from the first magnetic test coil 114A, the second magnetic test coil 114B detects voltage VT1, VT2 by differential amplifier circuit 21 (with reference to Fig. 2) amplification, and torque is detected voltage VT3 (dtc signal) to handling control ECU200 (with reference to Fig. 1) output.

(rotation terminal mechanism)

Secondly, in the time of with reference to Fig. 6, illustrate when turning to handling maneuver angle with wheel to arrive the tooth bar terminal angular at maximum handling maneuver angle, limit the rotation terminal 6A of mechanism of the action of steering handwheel 3.Fig. 6 is the schematic top plan view of the rotation terminal mechanism of present embodiment.In Fig. 6, (a) the expression steering handwheel with respect to about tooth bar end (tooth bar terminal angular) be positioned at the situation of center position, (b) the left operation state (state of [left tooth bar end]) made of expression, (c) the right operation state (state of [right tooth bar end]) made of expression.

As shown in Figure 1, the rotation terminal 6A of mechanism is at the axial location of input shaft 3d, be disposed at than the position that is provided with torque sensor 110 and rely on steering handwheel 3 side places, as shown in Figure 6, part periphery, that have outer peripheral face by being fixed in input shaft 3d to the rotary actuator 41 of the roughly cylindrical body of the outstanding protrusion 41a of radial outside and be fixed in the inner peripheral surface of cap 13A, the part with inner peripheral surface constitutes hill holder 40 to the fixed stop 43 of the roughly cylindrical body of the outstanding protrusion 43a of radially inner side.Rotary actuator 41 is in interior all sides of fixed stop 43, as steering handwheel 3 allow operational ton scope (allowing the rotary manipulation scope), can with roughly 180 ° rotate to the left and right.

Shown in Fig. 6 (a), steering handwheel 3 is positioned under the situation of center position, and protrusion 41a is positioned at 180 ° opposite sense with respect to protrusion 43a.

Rack shaft 8 is handled by a left side of making, suppose the structure as in the past, under the state of " the left tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, shown in figure (b), protrusion 41a week upwards pressing anticlockwise direction with protrusion 43a butt, even steering handwheel 3 is further turned left, further rotation or operating effort further do not transmit to torsion bar 111.Be applied under the situation from the counter-force of ground-surface load torque TL, detect torque at torque sensor 110, but do not have under its situation, detect less than torque.Especially, in the present embodiment, terminal 8b of tooth bar and shell end 11a during for the assembling of rack shaft 8 the location and prepare, and set with having some surpluses, with under the manipulation angle (operational ton) of the steering handwheel of making 3 that rotates the terminal 6A of mechanism restriction, terminal 8b of tooth bar and shell end 11a be butt not, therefore, even the rotation generation excess of stroke of electrical motor 4 is also to the directive effect that reduces the manipulation torque Ts that torque sensor 110 detects.

On the contrary, rack shaft 8 is handled by the right side of making, suppose as in the past, under the state of " the right tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, shown in (c), protrusion 41a week upwards in the direction of the clock with protrusion 43a butt, even with steering handwheel 3 further turning clockwises, further rotation or operating effort are also to torsion bar 111 transmission.Situation about handling with a described left side of making in the same manner, have some surpluses ground and set, so that terminal 8b of tooth bar and shell end 11a butt not, therefore, even the rotation generation excess of stroke (overshoot) of electrical motor 4 is also to the directive effect that reduces the manipulation torque Ts that torque sensor 110 detects.

Also have, in the (a) and (b) of Fig. 6, (c), the little situation of the amount of turning of imagination torsion bar 111 describes.

(handling control ECU)

Secondly, in the time of with reference to Fig. 7, Fig. 8 A, Fig. 8 B, describe handling control ECU.Fig. 7 is a functional block diagram of handling control ECU, Fig. 8 A is expression with respect to the data sheet of the relation of the basic signal of exporting as the dtc signal of the input of basic signal operation portion, and Fig. 8 B is with respect to the data sheet as the relation of the compensating signal of the rotating speed output of the electrical motor of the input of energy disperser compensating signal operational part.

Handling control ECU200 comprises: possess microcomputer and the program of CPU, ROM, RAM etc., be implemented in the function of putting down in writing in the functional block diagram of Fig. 7.

Handling control ECU200 possesses: basic signal operation portion 220; Inertia compensation signal operation portion 210; Energy disperser compensating signal operational part 225; Q axle (torque shaft) PI control part 240; D axle (magnetic pole axle) PI control part 245; Diaxon three-phase transformation component 260; PWM transformation component 270; Three-phase diaxon transformation component 265; Electromotor velocity is calculated portion 280; Exciting current generating unit 285.

It is D axle and to revolve the axle that turn 90 degrees with respect to this D axle electricity be the twin shaft electric current of Q axle that three-phase diaxon transformation component 265 will detect magnetic pole axle motor drive circuit 23, that three phase current IU, the IV of electrical motor 4, IW are transformed to the rotor of electrical motor 4, and the generation torque TM of Q shaft current IQ and electrical motor 4 is proportional, and D shaft current ID and exciting current are proportional.The angle signal θ that electromotor velocity is calculated 280 pairs of electrical motors 4 of portion differentiates, and generates angle signal ω M.Exciting current generating unit 285 generates the echo signal of the exciting current " 0 " of electrical motor 4, but as required, by making D shaft current and Q shaft current about equally, magnetic field control can weaken.

Base signal operation portion 220 generates basic signal DT as the benchmark of the echo signal IM of output torque TM ' by dtc signal VT3 and vehicle speed signal VS.This signal generates base table 220a by will utilizing setting such as measuring in advance to carry out reference based on dtc signal VT3 and vehicle speed signal VS and carries out, and represents to be stored in the function of the basic signal DT of base table 220a in Fig. 8 A.Base signal operation portion 220 is provided with in the value of dtc signal VT3 and hour basic signal DT is set at zero blunt band N1, and possesses when the value of dtc signal VT3 becomes bigger than blunt band N1, with the characteristic of gain G 1 straight line increase.In addition, basic signal operation portion 220 possesses: the output with the torque value of regulation increases with gain G 2, and then the saturated characteristic of output under the torque value situation about increasing.

In addition, usually, vehicle is according to moving velocity, and therefore ground-surface load (road surface counter-force) difference, utilizes vehicle speed signal VS to regulate gain.The speed of a motor vehicle zero blocked operation is set the time, it is the heaviest to load, when middle low speed, it is lighter to load.Therefore, basic signal operation portion 220 reduces gain (G1, G2) along with vehicle velocity V S increases at a high speed, and increases and set blunt band N1, increase manual power turn-around zone and give information of road surface to steerman.That is,, give the effect acid anhydride of firm manipulation torque Ts according to the increase of vehicle velocity V S.At this moment, also need to realize inertia compensation in the manual power turn-around zone.

Return Fig. 7, energy disperser compensating signal operational part 225 is in order to compensate the viscosity that steering system possesses, in addition, and in order to have when the high vehicle speeds, its turning to buffer function of compensation and being provided with under the situation that convergence reduces, angular velocity signal ω M carries out with reference to buffer table 225a.Fig. 8 B is the figure of the characteristic function of expression buffer table 225a, is increased more by the angular velocity omega M of electrical motor 4, and compensation value I is the part that increases of rectilinearity and constituting as a whole, and possesses the characteristic that compensation value I sharply increases with the angular velocity omega M of regulation.

In addition, the value of vehicle speed signal VS is high more, increases more gain, according to the cireular frequency of electrical motor 4, be handling maneuver speed (manipulation rotating speed), makes the output torque TM ' decay of electrical motor 4.

In other words, when reversing steering handwheel 3, reduce the electric current of electrical motor 4, when recovering, supply with big electric current on the contrary to electrical motor 4.For example, when increasing the reversing of steering handwheel 3, under the situation that angular velocity omega M accelerates, angular velocity omega M can not reduce immediately owing to the inertia of electrical motor 4, therefore, for fear of this phenomenon, energy disperser compensating signal operational part 225 increases the electric current of supplying with electrical motors 4, and the angular velocity omega M when suppressing the recovery of control steering handwheel 3.

In brief, reversing when increasing,, reducing electric current, increasing the weight of the manipulation sense of steering handwheel 3, when the recovery of steering handwheel 3, increasing electric current, making it be difficult to recover to electrical motor 4 to electrical motor 4 along with the angular velocity omega M of steering handwheel 3 uprises.Turn to the energy disperser effect by this, can improve the convergence of steering handwheel 3, the stabilization vehicle feature.

Return Fig. 7 once more, adder calculator 251 deducts the output signal of energy disperser compensating signal operational part 225 from the basic signal DT of basic signal operation portion 220 when reversing steering handwheel 3, opposite, when recovering steering handwheel 3, add the output signal of upper bumper compensating signal operational part 225.The output signal of the output signal of 250 pairs of adder calculators 251 of adder calculator and inertia compensation signal operation portion 210 carries out addition, and with it as output signal IM.Also have, carry out basic aux. controls by basic signal operation portion 220, energy disperser compensating signal operational part 225 and adder calculator 251.

The influence that inertia compensation signal operation portion 210 compensation is caused by the inertia of steering system, dtc signal VT3 is with reference to inertia table 210a and computing.

In addition, the reduction of the responsibility that causes of the inertia of the rotor of inertia compensation signal operation portion 210 compensated motors 4.In other words, from being rotated in the forward to contrarotation, or from contrarotation to being rotated in the forward when switching hand of rotation, utilize inertia, continue its state, therefore, hand of rotation can not be switched immediately.Therefore, inertia compensation signal operation portion 210 is that moment of switching with the hand of rotation of steering handwheel 3 is consistent with the switching controls of the hand of rotation of electrical motor 4.Like this, inertia compensation signal operation portion 210 improves the operating lag of the manipulation that the inertia (or viscosity) by steering system causes, gives happy manipulation sense.

In addition, for according to FF (Front engine Front wheel drive,) or vehicle state such as the speed of a motor vehicle of vehicle characteristics such as FR (Front engineRear wheel drive) car, RV (Recreation Vehicle) or car, road surface and different maneuvering characteristicss is given the practical sufficient characteristic that.

The output signal IM of adder calculator 250 is echo signals of Q shaft current of the torque of regulation electrical motor 4, and adder calculator 252 deducts Q shaft current IQ from output signal IM, generates deviation signal IE.Q axle (torque shaft) PI control part 240 is so that the mode that deviation signal IE reduces is carried out P (ratio) control and I (integration) control.Adder calculator 253 deducts D shaft current ID from the output signal of exciting current generating unit 285.D axle (magnetic pole axle) PI control part 245 returns control so that the mode that the output signal of adder calculator 253 reduces is carried out PI.

Diaxon three-phase transformation component 260 is three-phase signal UU, UV, UW with the diaxon signal transformation of the output signal VD of the output signal VQ of Q axle (torque shaft) PI control part 240 and D axle (magnetic pole axle) PI control part 245.PWM transformation component 270 generate as with load (DUTY) signal (load U, supported V, load W) of conduction and cut-off (ON/OFF) signal " PWM (Pulse WidthModulation) signal " of the pulse width that is in proportion of three-phase signal UU, UV, UW.

Also have, diaxon three-phase transformation component 260 and PWM transformation component 270 are transfused to the angle signal θ of electrical motor 4, and output is corresponding to the signal of the position of magnetic pole of rotor.

(effect, the effect of rotation terminal mechanism)

Secondly, in the time of with reference to Fig. 1, Fig. 6 and Fig. 9 A～C, effect, the effect of the rotation terminal 6A of mechanism of present embodiment is described.

In Fig. 1, the position relation of rack shaft 8 and tooth bar housing section 11A is as follows, if hypothesis is not rotated the 6A of terminal mechanism, and then the terminal 8b engaging of the tooth bar of the shell end 11a of the right-hand member of tooth bar housing section 11A and rack shaft 8 contacts, or when the terminal 8b engaging of tooth bar of the shell end 11a of the left end of tooth bar housing section 11A and rack shaft 8 contacts on the contrary, and then to the right or the moving steering handwheel 3 that turns left, then in driven steering device in the past, apply recently from the big load-carrying of the load of front- wheel 1L, 1R to rack shaft 8 from pinion shaft 7.

This has following two reasons.

The position relation that is not rack shaft 8 and tooth bar housing section 11A be in terminal promptly to the left and right the either party make under the situation of the state that switches front- wheel 1L, 1R, if will be made as TL from the load torque of front- wheel 1L, 1R, then handle exist between torque Ts, auxiliary quantity AH and the miniature gears torque Tp as shown in the formula relation.

Ts+AH＝Tp＝TL ·····(3)

But, make under the state that switches front- wheel 1L, 1R either party to the left and right, under the state of terminal 8b of tooth bar and shell end 11a butt, and then steerman applies under the situation of (switching increases) operating effort to steering handwheel 3 to described direction, the load torque TL that applies from front- wheel 1L, 1R can further not increase, but torsion bar 111 further turns significantly, handling torque Ts in torque sensor 110 detects significantly, in handling control ECU200, will increase the instruction of current value to motor drive circuit 23 outputs to electrical motor 4.Also have, further increase, apply the torque bigger to rack shaft 8 than load torque TL through miniature gears 7a, tooth bar 8a by auxiliary quantity AH increase and manipulation torque Ts.

Ts+AH＝Tp>TL ·····(4)

Under such situation, apply about 1.3 times load of the load when not reaching tooth bar terminal angular common to electrical motor 4, worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, 3g or tooth bar terminal 8b, tooth bar housing section 11A.

In addition, consider the moment of terminal 8b of tooth bar and shell end 11a butt.At this, if the spin velocity of electrical motor 4 is made as ω M, rotatory inertia moment is made as IM, then on electrical motor 4, accumulate kinetic energy EM with being shown below.

EM＝(1/2)·IM·ωM2 ·····(5)

This kinetic energy is absorbed by elastic deformations such as worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, 3g or tooth bar terminal 8b, shell end 11a, and the impact load of this moment increases to about 1.5 times of the common load that do not reach the tooth bar terminal angular.

Because these auxiliary quantities AH, manipulation torque Ts or impact load, about 2 times load of common load puts on electrical motor 4, worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, 3g or tooth bar terminal 8b, tooth bar housing section 11A, when guaranteeing the durability of these component parts, there is the size that increases bearing, or the module of increase gear, increased in size, or thicken the wall thickness of tooth bar housing section 11A, or the weight that component parts such as strengthening rib are set becomes big problem.In electricity relation, electrical motor 4 overload that becomes may cause blowing.

But, according to present embodiment as can be known, before the location is with tooth bar end 8b and shell end 11a butt, protrusion 41a, 43a be butt, make that input shaft 3d can not further switch increase in the rotation terminal 6A of mechanism, further increase the operating effort that reverses from steering handwheel 3 and do not transmit to torsion bar 111.Also have, torsion bar 111 does not produce above the turning that turn that load torque TL causes yet, therefore, is handling between torque Ts, auxiliary quantity AH, miniature gears torque Tp and the load torque TL, the relation of freeze mode (3), not producing increases the further auxiliary quantity AH from electrical motor 4 that reverses and cause.In addition, the location has surplus ground with terminal 8b of tooth bar and shell end 11a than maximum handling maneuver angle (tooth bar terminal angular) and is provided with, therefore, if the rotation generation excess of stroke of electrical motor 4, then reduce the manipulation torque Ts that torque sensor 110 detects, reduce auxiliary quantity AH.Its result is shown in (6).

Ts+AH＝Tp<TL ·····(6)

Secondly, in the time of with reference to Fig. 9 A～C, illustrate the handling maneuver angle of the situation of steering handwheel 3 increase twist operation till the tooth bar terminal angular and the action of dtc signal VT3.

Fig. 9 A is the chart of time lapse of the operational ton of expression steering handwheel, and Fig. 9 B is the chart of expression from the time lapse of the dtc signal VT3 of torque sensor output, and Fig. 9 C is the chart of time lapse of variation at the handling maneuver angle of the actual front-wheel of expression.

Shown in Fig. 9 A, if reverse steering handwheel 3 significantly, be operated near the tooth bar terminal angular, then shown in the curve x1 under the situation of present embodiment, before terminal 8b of tooth bar and shell end 11a butt, torsion bar 111 is turned, and when time t1, utilizes the rotation terminal 6A of mechanism to stop the increase of the operational ton of steering handwheel 3.

Also have, shown in the curve y1 of Fig. 9 B, till time t1, the big variation of the operational ton by steering handwheel 3, dtc signal continued to increase before time t1, but when time t1, the increase of the operational ton of steering handwheel 3 becomes zero, and therefore, the increase of dtc signal stops.Also have, shown in the curve z1 of Fig. 9 C, the excess of stroke is omited than tooth bar terminal angular in the handling maneuver angle of front-wheel 1L, 1R.Shown in the curve y1 of Fig. 9 B, by this excess of stroke, dtc signal VT3 reduces.This excess of stroke is the resultant of the kinetic energy that causes of the moment of inertia of electrical motor 4.

To this, in the prior art, shown in curve z2 among Fig. 9 C, therefore terminal 8b of tooth bar and shell end 11a butt, stop the variation (increase) at handling maneuver angle.But shown in the curve x2 of Fig. 9 A, the operational ton of steering handwheel 3 also has convergence owing to the influence of the steering handwheel moment of inertia that the operation of the steering handwheel 3 of steerman causes increases.

At this moment, shown in the curve y2 of Fig. 9 B, under the tooth bar terminal angular, dtc signal VT3 is interim sharply to rise, and the kinetic energy that the moment of inertia of electrical motor 4 causes produces impulsive force to gear class (worm-gear toothing 5a, gear on worm 5b, tooth bar 8a, miniature gears 7a etc.).

Thereby,, under the tooth bar terminal angular, the conflict of terminal 8b of tooth bar and shell end 11a takes place, and shown in Fig. 9 B, dtc signal VT3 increases further, and the impact that the kinetic energy of electrical motor 4 causes is had an effect as in the past shown in the curve z2 of Fig. 9 C.

According to present embodiment as can be known, as mentioned above, during near the tooth bar terminal angular of steering handwheel 3 increase twist operation or in the big twist operation till the tooth bar terminal angular, can avoid the conflict of terminal 8b of tooth bar and shell end 11a, therefore, miniature gears torque Tp can be reduced to below the identical degree of miniature gears torque Tp when not reaching tooth bar terminal angular common.

Thereby, can be reduced in electrical motor 4, worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, the terminal 8b of 3g or tooth bar, the load that should imagine in the design of tooth bar housing section 11A, eliminated the size that in the past increases bearing in order to ensure the durability of these component parts, or the module of increase gear, increased in size, or the wall thickness of increase tooth bar housing section 11A, or strengthening rib etc. is set causes the weight of component parts to become big problem, can be small-sized, the lightweight component parts improves the lift-launch on the vehicle, especially the lift-launch on the dilly.

In addition, even increase operation in order further to switch under the state of tooth bar end, electrical motor 4 can not be blown yet, and need the electric current capacitor strap that surplus is arranged, but relax it, thus can lightweight electrical motor 4.

" variation of rotation terminal mechanism "

Rotation terminal of the present invention mechanism is not limited to described embodiment, for example, can carry out various distortion as described below.

(first variation of first embodiment)

Secondly, in the time of with reference to Figure 10, first variation of the rotation terminal mechanism of first embodiment is described.Figure 10 is the schematic top plan view of the rotation terminal mechanism of this variation.(a) be the expression steering handwheel with respect to about be positioned at the figure of the situation of center position, (b) be the figure of the left operation state (state of [left tooth bar end]) made of expression, (c) be the figure of the right operation state (state of [right tooth bar end]) made of expression.

As shown in figure 10, the rotation terminal 6B of mechanism comprises: with axle 51 in the input shaft 3d bonded assembly, be disposed at the rotary actuator 53 in its outside and and then be disposed at the fixed stop 54 in its outside.

Interior axle 51 is provided with external gear 51a, has with the rotary actuator (Ring gear) 53 of described external gear 51a ingear inner gear 53a and interior axle 51 eccentric and be provided with at inner peripheral surface.The number of teeth of external gear 51a and inner gear 53a is roughly 1:3.

Radial outside at the outer peripheral face of rotary actuator 53 is provided with outstanding protrusion (first protrusion) 53b of a part that makes outer peripheral face.In addition, be provided with and have the inner peripheral surface that is fixed in cap 13A, and a part that makes inner peripheral surface to outstanding protrusion (second protrusion) 54a of radially inner side and with the fixed stop 54 of the coaxial roughly cylindrical body of rotary actuator 53, utilize rotary actuator 53 and fixed stop 54 to constitute hill holders 50.

External gear 51a and inner gear 53a constitute speed reduction gearing 55, if steering handwheel 3 is rotated about 540 ° respectively to the left and right from neutral condition, then rotary actuator 53 rotates about 180 ° respectively to the left and right, and protrusion 53a is from circumferential and protrusion 54a butt.

Also have, omit diagram, but the outer peripheral face of the upper and lower end parts of rotary actuator 53 form the cylinder side face full week, utilize described partial sum to constitute plain bearing, can be rotated the rotation of hill holder 53 thus in the little part of the upper and lower side of fixed stop 54 diameter that be provided with, the full Zhou Chengwei cylinder of inner peripheral surface side face.

Shown in Figure 10 (a), steering handwheel 3 is positioned under the situation of center position, and protrusion 53a is positioned at 180 ° of opposite senses with respect to protrusion 54a.

Rack shaft 8 is handled by a left side of making, under the state of " the left tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, shown in figure (b), protrusion 53a is upwards pressing anticlockwise direction and protrusion 54a butt week, even with steering handwheel 3 further anti-clockwise rotations, further rotation or operating effort can not transmit to torsion bar 111 yet.On the contrary, rack shaft 8 is handled by the right side of making, under the state of " the right tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, shown in figure (c), protrusion 53a week upwards in the direction of the clock with protrusion 54a butt, even with steering handwheel 3 further right-hand revolutions, further rotation or operating effort can not transmit to torsion bar 111 yet.

According to the rotation terminal 6B of mechanism of this variation as can be known, compare with the rotation terminal 6A of mechanism of first embodiment, the operational ton scope (allowing the rotary manipulation scope) of allowing till the tooth bar terminal angular of steering handwheel 3 becomes 540 ° to the left and right, therefore, can form the operational ton of the steering handwheel 3 in the common vehicle, all right.And then, by rotary actuator (Ring gear) 53 being replaced by the hill holder that changes the number of teeth, for example, can will allow that the operational ton scope is set in the scope of 450 ° or 600 °.That is, operational ton can be changed, various car types can be tackled corresponding to the steering handwheel of tooth bar terminal angular.

In this variation, also with first embodiment in the same manner, increase operation steering handwheel 3 even steerman has been in the state of tooth bar end and then has reversed from rack shaft 8, also stop the rotary manipulation of the rotation terminal 6B of mechanism, switch the operating effort that increases and also can not transmit to torsion bar 111.Also have, handling between torque Ts, auxiliary quantity AH, miniature gears torque Tp and the load torque TL, the relation of freeze mode (3) or formula (6), not producing to reverse increases further auxiliary quantity AH or the manipulation torque Ts from electrical motor 4 that causes.

In addition, in the big switching rotary manipulation that arrives the tooth bar end, do not have yet, therefore, avoid conflict as terminal 8b of the tooth bar that limited the tooth bar terminal angular and shell end 11a in the past.

Thereby, can be reduced in electrical motor 4, worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, the terminal 8b of 3g or tooth bar, the load that should imagine in the design of tooth bar housing section 11A, eliminated the size that in the past increases bearing in order to ensure the durability of these component parts, or the module of increase gear, increased in size, or the wall thickness of increase tooth bar housing section 11A, or strengthening rib etc. is set causes the weight of component parts to become big problem, can be small-sized, the lightweight component parts improves the lift-launch on the vehicle, especially the lift-launch on the dilly.In addition, can make electric current electric capacity have surplus, can lightweight electrical motor 4.

Also have, be the speed reduction gearing of angle of rotation about 180 ° about rotary actuator 53, be not limited to the external gear 51a in first variation and the speed reduction gearing 55 of inner gear 53a combination as operational ton about 540 ° about steering handwheel 3 is slowed down.

(second variation of first embodiment)

Secondly, in the time of with reference to Figure 11, the rotation terminal mechanism of second variation of first embodiment is described.Figure 11 has been to use the schematic perspective view of rotation terminal mechanism of second variation of planetary gear reduction unit.

As shown in figure 11, use planet-gear speed reducer unit 59 also can, this planet-gear speed reducer unit 59 comprises: sun gear 56, with the planetary wheel 57 of sun gear 56 engagements and revolution around sun gear 56, have with the external gear 58 of planetary wheel 57 ingear internal tooths, link the pinion carrier 57a of the axle of planetary wheel 57.

In this case, input shaft 3d forms the form that drives sun gear 56, and planetary wheel 57a is with respect to rotary actuator 53, for example, have to outstanding protrusion (first protrusion) 57b of radial outside, external gear 58 is equivalent to fixed stop 54, is fixed in cap 13A, in order not disturb with planetary wheel 57, for example, the outer edge side of the end face edge 58a of portion of outer ring gear 58 is outstanding vertically, form protrusion (second protrusion) 58b, 57b engages with protrusion.If the number of teeth a of sun gear and the number of teeth c of outer ring gear are chosen as 1:2, then with respect to the angle of rotation of sun gear 56, the angle of rotation of planetary wheel 57a can be decelerated to 1/3, with first variation of first embodiment in the same manner, with respect to allow about operational ton scope (allowing the rotary manipulation scope) about 540 ° of steering handwheel 3, about the angle of rotation of planetary wheel 57a (rotary actuator 53) can being made as about 180 °.

Also have, in example shown in Figure 11, be provided with protrusion 57b from planetary wheel 57a to radial outside, but be not limited to this, to the outstanding protrusion 57b that is provided with of axial side (being upper side among Figure 11), outstanding and protrusion 58b is set also can to radially inner side from the end face edge 58a of portion of outer ring gear 58.

In addition, protrusion 58b is set to radially inner side is outstanding, also can to engage with protrusion 57b from the inner peripheral surface of cap 13A.

As speed reduction gearing 55, use the epicyclic reduction gear unit, can make rotation terminal mechanism and cap 13A spigot shaft coaxle thus, rotation terminal portion of mechanism radially can reduce.And then when protrusion 57b and protrusion 58b butt, the load that puts on protrusion 57b passes through pinion carrier 57a, and is born by each planetary wheel 57 respectively, therefore can stand the big load of situation than the rotation terminal 6B of mechanism of second variation.Correspondingly the terminal 6B ' of mechanism is rotated in miniaturization.

(the 3rd variation of first embodiment)

Secondly, in the time of with reference to Figure 12, Figure 13 A～D, the 3rd variation of the rotation terminal mechanism of first embodiment is described.Figure 12 is the schematic top plan view of the rotation terminal mechanism of this variation.(a) be the expression steering handwheel with respect to about be positioned at the figure of the situation of center position, (b) be the figure of the left operation state (state of [left tooth bar end]) made of expression, (c) be the figure of the right operation state (state of [right tooth bar end]) made of expression.Figure 13 A～D is the block diagram of key element of representing to constitute the rotation terminal mechanism of the 3rd variation individually, Figure 13 A is a profile block diagram of going up hill holder, Figure 13 B is the profile block diagram that is fixed in the rotary actuator of threaded portion, Figure 13 C is the profile block diagram of following hill holder, and Figure 13 D is the profile block diagram of guide member.

Shown in Figure 13 A～D, the rotation terminal 6C of mechanism comprises: the threaded portion 61 of cutting external screw thread 61a in the periphery of input shaft 3d; Be fixedly welded on the rotary actuator (first hill holder) 62 of roughly cylindrical body of the axial central authorities of threaded portion 61; Be disposed at the last hill holder (second hill holder) 63 up and down of rotary actuator 62, following hill holder (the 3rd hill holder) 65; Guide member 67.

Rotary actuator 62 forms roughly cylindrical body shown in Figure 13 B, have the part that makes outer peripheral face to outstanding protrusion (first protrusion) 62a of radial outside.

Also have, the radially outermost end of protrusion 62a forms littler than the diameter of the inner peripheral surface of guide member 67.

Last hill holder 63, following hill holder 65 are shown in Figure 13 A, Figure 13 C, form roughly cylindrical body, have the negative thread 63a that is fit to external screw thread 61a in interior all sides, have outstanding guide plate 63b and protrusion (second protrusion) 63c of a part that makes outer peripheral face at 180 ° of opposed radial outsides.This guide plate 63b and protrusion 63c engage with the upwardly extending bullport 67b of axle described later at guide member 67, and by the rotation about threaded portion 61, last hill holder 63 guides to bullport 67b, and moves up and down in the axial direction.

Guide plate 63b forms neat face with the cylindrical body portion of identical axial width and last hill holder 63, but as shown in FIG. 13A, protrusion 63c is to axially side-prominent down.

Following hill holder 65 is identical with last hill holder 63 as ending eastern device, is turned upside down, is the structure identical with last hill holder 63.The protrusion 65c of following hill holder 65 is corresponding to the 3rd protrusion of putting down in writing among the present invention.

Constitute hill holder 60 by rotary actuator 62, last hill holder 63 and following hill holder 65.

Guide member 67 has made up parts 67A, the 67B that cylindrical body is divided into vertically half, the bullport 67b that parts 67A, 67B separately has the sawtooth 67a that extends vertically and extend vertically in circumferential central authorities at outer peripheral face.Sawtooth 67a and the not shown engagement that is provided with at the inner peripheral surface of cap 13A are used to make guide member 67 to be fixed in week in cap 13A and upwards can not move.

Like this, guide member 67 forms segmenting structure, therefore, the external diameter of the axial both sides of threaded portion 61 can be formed than last hill holder 63 and the internal diameter of the ridge of negative thread 63a, the 65a of hill holder 65 is little down, from above-below direction and threaded portion 61 combinations, then, guide plate 63b, 65b and protrusion 63c, 65c are embedded among the bullport 67b of separately parts 67A, 67B the guide member 67 that is assembled into one.Then, guide member 67 is pressed into the inner peripheral surface of cap 13A and fixes.

External screw thread 61a, negative thread 63a and negative thread 65a constitute speed reduction gearing, if steering handwheel 3 is rotated about 540 ° respectively to the left and right from neutral condition, then rotary actuator 62 rotates about 540 ° respectively to the left and right, last hill holder 63 reaches the mobile vertically same amount of hill holder 65 difference down, for example, when left steering is handled, be moved upward, when right steering is handled, move downwards.Also have, when rotary actuator 62 rotated about 540 ° respectively to the left and right, protrusion 62a made progress and protrusion 65c butt in week, and when right steering was handled, protrusion 62a made progress and protrusion 63c butt in week.

That is, with first variation of first embodiment in the same manner, can guarantee allow about operational ton scope (allowing the rotary manipulation scope) about 540 ° of steering handwheel 3.And then, under the situation of the profile that does not increase the rotation terminal 6C of mechanism, for example, can also allow that the operational ton scope is set at two rotations (720 °) to the left and right respectively, can also be applicable to automobile vehicle in addition.

In (a) of Figure 12, be illustrated in steering handwheel 3 under the situation of center position, protrusion 62a is positioned at axial central authorities with respect to protrusion 63c, 65c.In (b), expression: rack shaft 8 is handled by a left side of making, under the state of " the left tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, protrusion 62a week upwards by from above anticlockwise direction and protrusion 65c butt under the situation of observing, even steering handwheel 3 is further rotated left, the further state that also do not transmit of rotation or operating effort to torsion bar 111.Expression in (c): opposite rack shaft 8 is handled by the right side of making, under the state of " the right tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, protrusion 62a week upwards by from above clockwise direction and protrusion 63c butt under the situation of observing, even steering handwheel 3 is further rotated to the right, the further state that also do not transmit of rotation or operating effort to torsion bar 111.

In this variation, also with first embodiment in the same manner, steerman reverses steering handwheel 3 from further the increasing of state that rack shaft 8 has been in the tooth bar end, and rotary manipulation also is rotated the 6C of terminal mechanism to be stoped, and increases the operating effort that reverses and also can not transmit to torsion bar 111.Also have, handling between torque Ts, auxiliary quantity AH, miniature gears torque Tp and the load torque TL, the relation of freeze mode (3) or formula (6) does not produce to increase and reverses further auxiliary quantity AH or the manipulation torque Ts from electrical motor 4 that causes.

In addition, in the big rotary manipulation that arrives the tooth bar end,, therefore, avoid conflict because do not have as terminal 8b of the tooth bar that limited the tooth bar terminal angular and shell end 11a in the past.

Its result, with first embodiment in the same manner, can reduce electrical motor 4, worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, the terminal 8b of 3g or tooth bar, the load that should imagine in the design of tooth bar housing section 11A, eliminated the size that in the past increases bearing in order to ensure the durability of these component parts, or the module of increase gear, increased in size, or the wall thickness of increase tooth bar housing section 11A, or strengthening rib etc. is set causes the weight of component parts to become big problem, can be small-sized, the lightweight component parts improves the lift-launch on the vehicle, especially the lift-launch on the dilly.In addition, can make electric current electric capacity have surplus, can lightweight electrical motor 4.

The driven steering device 100A of first embodiment utilizes electrical motor 4 assistive drive pinion shafts 7 via speed reduction gearing 5A, but is not limited to this.In addition,,, utilize the first magnetic test coil 114A, 114B to detect its addendum modification with the addendum modification up and down that angular transformation is a slide block 115 that turns of torsion bar 111 as torque sensor, output torque signal VT3, but be not limited to this.

" second embodiment "

Secondly, in the time of with reference to Figure 14, the driven steering device of second embodiment of the present invention is described.

Figure 14 is the constructional drawing of the driven steering device of second embodiment of the present invention.The driven steering device 100B of present embodiment utilizes the type of electrical motor 4 via ball screw 5c assistive drive rack shaft 8.

Be with the difference of first embodiment, replace electrical motor 4 via worm-gear toothing 5a and gear on worm 5b Drive pinion axle 7, in the present embodiment, electrical motor 4 drives speed reduction gearing (assist torque transmission mechanism) 5B and the ball screw 5c that is made of worm-gear toothing 5a and gear on worm 5b, is that the straight-line motion of rack shaft 8 drives with the Direct Transform that rotatablely moves of ball screw 5c.

Difference is in addition, replaces the torque sensor 110 of first embodiment, in the present embodiment, forms the torque sensor 120 that has used magnetostrictive film.

About the structure identical with first embodiment, mark identical symbol, the repetitive description thereof will be omitted.

Also have, the configuration of speed reduction gearing (assist torque transmission mechanism) 5B is different with first embodiment, and therefore, the tooth bar housing section 11B of the steering box 10B of present embodiment and the shape of cap 13B are different with first embodiment, but function is roughly the same.

Torque sensor 120 is for leaving the identical structure of putting down in writing among 2006-No. 322952 communique Fig. 1, Fig. 2 of structure with the spy, the magnetostriction materials of the magnetostriction constant that expression Fe-Ni system or Fe-Cr system etc. are positive utilize plating or evaporation etc., with the thickness of regulation, for example below 30 microns, on circumferentially full week, the axially spaced-apart of regulation is set, two places on being formed at axially constitute the first magnetostrictive film 121A and the second magnetostrictive film 121B.And, for obtaining reverse magnetic anisotropy respectively, under the state of the torque that has applied regulation to input shaft 3d, utilize diathermic heating to heat, and revert to room temperature, give by removing torque.Thus, do not put under the situation of first and second magnetostrictive film 121A, 121B turning torque, also be applied in drawing stress often, give the distortion of stretching, therefore, the magnetic hysteresis of converse magnetostriction characteristic aspect diminishes.In addition, different with the torque sensor 110 of described first embodiment, do not have torsion bar 111, it does not take place turn, therefore, the manipulation angle of steering handwheel 3 and the handling maneuver angle of front-wheel 1L, 1R do not turn difference ground correspondence.Its result, the scope of determining with rotation terminal mechanism 6 of allowing the cooresponding handling maneuver of operational ton scope angle also broadens basically.

Also have, not shown excitation coil in the torque sensor 120 is disposed at first and second magnetostrictive film 121A, 121B via small space jointly, in week upwards with excitation coil away from 90 ° circumferential position via small space, dispose the first magnetic test coil 124A with respect to the first magnetostrictive film 121A, dispose the second magnetic test coil 124B with respect to the second magnetostrictive film 121B.

In torque sensor 120, torque is when input shaft 3d, and torque also acts on first and second magnetostrictive film 121A, 121B, corresponding to this torque, also produces the converse magnetostriction effect at first and second magnetostrictive film 121A, 121B.If never graphic field voltage supply source is to the alternating-current voltage/AC voltage (field voltage) of above-mentioned excitation coil supply high frequency, the variation that then can utilize the magnetic field that first and second magnetic test coil 124A, 124B will cause based on the converse magnetostriction effect of the torque that puts on first and second magnetostrictive film 121A, 121B detects respectively as the variation of impedance or inductive drop.At this moment, except turning the torque of input shaft 3d, also form the state that drawing stress puts on first and second magnetostrictive film 121A, 121B often, therefore, obtain the little characteristic of magnetic hysteresis, can put on the torque of input shaft 3d by the change-detection of this impedance or inductive drop.

Signal voltage VT1, the VT2 input differential amplifier circuit of exporting respectively from first and second magnetic test coil 124A, 124B 21 also is exaggerated, and control ECU200 is handled in input as dtc signal VT3.

In the present embodiment, rotation terminating set 6 also is disposed at than the position that is provided with torque sensor 120 at the axial location of input shaft 3d and relies on steering handwheel 3 side places.

Also have, in Figure 14, the described rotation terminal 6A of mechanism of rotation terminal mechanism 6 representatives, 6B, 6B ', 6C and represent use arbitrary rotation terminal 6A of mechanism, 6B, 6B ', 6C also can.

In the present embodiment, also with first embodiment and variation thereof in the same manner, be in the state of tooth bar end from rack shaft 8, even further switching, steerman increases operation steering handwheel 3, rotary manipulation is rotated terminal mechanism 6 to be stoped, and switches the operating effort that increases and also can not transmit to first and second magnetostrictive film 121A, the 121B of torque sensor 120.Also have, handling between torque Ts, auxiliary quantity AH, miniature gears torque Tp and the load torque TL, the relation of freeze mode (3) or formula (6), not producing to switch increases further auxiliary quantity AH or the manipulation torque Ts from electrical motor 4 that causes.

In addition, in the big rotary manipulation that arrives the tooth bar end, do not have yet, therefore, avoid conflict as terminal 8b of the tooth bar that limited the tooth bar terminal angular and shell end 11a in the past.

Thereby, can be reduced in electrical motor 4, worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, the terminal 8b of 3g or tooth bar, the load that should imagine in the design of tooth bar housing section 11A, eliminated the size that in the past increases bearing in order to ensure the durability of these component parts, or the module of increase gear, increased in size, or the wall thickness of increase tooth bar housing section 11A, or strengthening rib etc. is set causes the weight of component parts to become big problem, can be small-sized, the lightweight component parts improves the lift-launch on the vehicle, especially the lift-launch on the dilly.In addition, can make electric current electric capacity have surplus, can lightweight electrical motor 4.

" the 3rd embodiment "

Secondly, in the time of with reference to Figure 15, the driven steering device of the 3rd embodiment of the present invention is described.

Figure 15 is the constructional drawing of the driven steering device of the 3rd embodiment of the present invention.The driven steering device 100C of present embodiment be utilize electrical motor 4 via worm-gear toothing 5a, gear on worm 5b the type of assistive drive steering-wheel spindle 3a.

Be with the first embodiment difference, replace electrical motor 4 via worm-gear toothing 5a and gear on worm 5b Drive pinion axle 7, in the present embodiment, electrical motor 4 drives steering-wheel spindle 3a via the speed reduction gearing that is made of worm-gear toothing 5a and gear on worm 5b (assist torque transmission mechanism) 5A.

Difference is in addition, replaces the torque sensor 110 of first embodiment, in the present embodiment, forms the torque sensor 120 that has used magnetostrictive film.

Driven steering device 100C is to utilize axle 3c and two Hooke's coupling 3b to link post housing 15 and the structure between the outstanding pinion shaft 7 in the top of the cap 13C of steering box 10C of the steering-wheel spindle 3a that accommodates steering handwheel 3 as shown in figure 15.

The below configuration of the sealing member 3h that post housing 15 is provided with is in the top also accommodated bearing 3e, thereunder dispose and accommodate rotation terminal mechanism 6, torque sensor 120, bearing 3i, gear on worm 5b, bearing 3j successively, the lower end of the steering-wheel spindle 3a that extends from the lower ends downward side of post housing 15 is that output shaft 3k is linked to Hooke's coupling 3b.The tooth bar 8a engagement of the miniature gears 7a that is provided with in the bottom of pinion shaft 7 and rack shaft 8 that can back and forth movement on the overall width direction, front- wheel 1L, 1R about the two ends of rack shaft 8 link via link rod 9,9.

About with first embodiment and the identical structure of second embodiment, mark identical symbol, omit repeat specification.

Also have, the configuration and first embodiment of speed reduction gearing (assist torque transmission mechanism) 5A are inequality, and therefore, the tooth bar housing section 11C of the steering box 10C of present embodiment and the shape of cap 13C are different with first embodiment, but function is roughly the same.But, do not dispose rotation terminal mechanism 6 at cap 13C, do not need the maintenance function of the rotation terminal mechanism 6 in first and second embodiment.

In addition, the torque sensor 120 of present embodiment is contained in the post housing 15, on the outer peripheral face of steering-wheel spindle 3a, form first and second magnetostrictive film 121A, 121B, at described first and second magnetostrictive film 121A, 121B via small gap, configuration excitation coil, first and second magnetic test coil 124A, 124B this point are only different with second embodiment, and the structure torque sensor 120 with second embodiment basically is identical.

In the present embodiment, rotation terminating set 6 also is disposed at than the position that is provided with torque sensor 120 and relies on steering handwheel 3 side places at the axial location of steering-wheel spindle 3a.

Also have, in Figure 15, the described rotation terminal 6A of mechanism of rotation terminal mechanism 6 representatives, 6B, 6B ', 6C and represent use arbitrary rotation terminal 6A of mechanism, 6B, 6B ', 6C also can.

According to present embodiment as can be known, also with first embodiment and variation thereof in the same manner, steerman further increases rotation steering handwheel 3 from the state that rack shaft 8 has been in the tooth bar end, rotary manipulation also is rotated terminal mechanism 6 to be stoped, and the operating effort that rotation increases can not transmit to first and second magnetostrictive film 121A, the 121B of torque sensor 120 yet.Also have, handling between torque Ts, auxiliary quantity AH, miniature gears torque Tp and the load torque TL, the relation of freeze mode (3) or formula (6), not producing rotation increases further auxiliary quantity AH or the manipulation torque Ts from electrical motor 4 that causes.

In addition, in the big switching rotary manipulation that arrives the tooth bar end, do not have yet, therefore, avoid conflict as terminal 8b of the tooth bar that limited the tooth bar terminal angular and shell end 11a in the past.

Rotation terminal mechanism 6 is set near steering handwheel 3, therefore, regulates the cooperation at the center of the center of steering-wheel spindle 3a of steering handwheel 3 and rotation terminal mechanism 6 easily.

Thereby, can be reduced in electrical motor 4, worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, the terminal 8b of 3g or tooth bar, the load that should imagine in the design of tooth bar housing section 11A, eliminated the size that in the past increases bearing in order to ensure the durability of these component parts, or the module of increase gear, increased in size, or the wall thickness of increase tooth bar housing section 11A, or strengthening rib etc. is set causes the weight of component parts to become big problem, can be small-sized, the lightweight component parts improves the lift-launch on the vehicle, especially the lift-launch on the dilly.In addition, can make electric current electric capacity have surplus, can lightweight electrical motor 4.

" the 4th embodiment "

In the time of with reference to Figure 16 to Figure 20 A～C, the 4th embodiment of the present invention is described.Also have, shown in Figure 16,17,18, the driven steering device 100D of present embodiment is different with the driven steering device 100A of first embodiment (with reference to Fig. 1,2,4) except the position that is provided with rotation terminal mechanism, and structure is substantially the same, omits repeat specification.

Shown in Figure 16,17, the rotation terminal 6D of mechanism is arranged between torque sensor 110 and the gear on worm 5b at the axial location of input shaft 3d.

Shown in Figure 19 (a), steering handwheel 3 is positioned under the situation of center position, and protrusion 41a is positioned at 180 ° of opposite senses with respect to protrusion 43a.

Rack shaft 8 is handled by a left side of making, and under the state of the tooth bar terminal angular of " left tooth bar end ", shown in Figure 19 (b), protrusion 41a is upwards pressing anticlockwise direction and protrusion 43a butt week, steering handwheel 3 further can not be rotated left.

On the contrary, rack shaft 8 is handled by a left side of making, under the state of the tooth bar terminal angular of " right tooth bar end ", shown in Figure 19 (c), protrusion 41a week upwards in the direction of the clock with protrusion 43a butt, steering handwheel 3 further can not be rotated to the right.

(effect, the effect of rotation terminal mechanism)

Secondly, in the time of with reference to Figure 16, Figure 19 and Figure 20 A～C, effect, the effect of the rotation terminal 6D of mechanism of present embodiment is described.

In Figure 16, the position relation of rack shaft 8 and shell end 11a is as follows, if hypothesis is not rotated the 6A of terminal mechanism, and then the terminal 8b engaging of the tooth bar of the shell end 11a of the right-hand member of tooth bar housing section 11A and rack shaft 8 contacts, or when the terminal 8b engaging of tooth bar of the shell end 11A of the left end of tooth bar housing section 11A and rack shaft 8 contacts on the contrary, and then to the right or the moving steering handwheel 3 that turns left, then in driven steering device in the past, apply recently from the big load-carrying of the load of front- wheel 1L, 1R to rack shaft 8 from pinion shaft 7.

This has following reason.

The position relation that is not rack shaft 8 and tooth bar housing section 11A be in terminal promptly to the left and right the either party make under the situation of the state that switches front- wheel 1L, 1R, if will be made as TL from the load torque of front- wheel 1L, 1R, then handle exist between torque Ts, auxiliary quantity AH and the miniature gears torque Tp as shown in the formula relation.

Ts+AH＝Tp＝TL ·····(3)

In addition, consider the moment of terminal 8b of tooth bar and shell end 11a butt.At this, if the spin velocity of electrical motor 4 is made as ω M, rotatory inertia moment is made as IM, then on electrical motor 4, accumulate kinetic energy EM with being shown below.

EM＝(1/2)·IM·ωM2 ·····(4)

This kinetic energy is absorbed by elastic deformations such as worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, 3g or tooth bar terminal 8b, shell end 11a, and the overload of this moment increases to about 1.5 times of the common load that does not reach the tooth bar terminal angular.

Because these auxiliary quantities AH, manipulation torque Ts or overload, about 1.5 times load of common load puts on electrical motor 4, worm-gear toothing 5a, gear on worm 5b, miniature gears 7a, tooth bar 8a, bearing 3e, 3f, 3g or tooth bar terminal 8b, tooth bar housing section 11A, when guaranteeing the durability of these component parts, there is the size that increases bearing, or the module of increase gear, increased in size, or thicken the wall thickness of tooth bar housing section 11A, or the weight that component parts such as strengthening rib are set becomes big problem.

But, according to present embodiment as can be known, before terminal 8b of the tooth bar of location usefulness and shell end 11a butt, protrusion 41a, 43a be butt, make that pinion shaft 7 can not further switch increase in the rotation terminal 6D of mechanism, the impulsive force that the moment of inertia of electrical motor 4 (kinetic energy) causes is absorbed by the butt (butt of protrusion 41a and protrusion 43a) of protrusion 41a, the 43a of the rotation terminal 6D of mechanism, does not transmit to miniature gears 7a or tooth bar 8a, rack shaft 8, tooth bar terminal 8b, shell end 11a via pinion shaft 7.And, the rotation terminal 6D of mechanism is arranged at the torque sensor side (upstream side) of speed reduction gearing (assist torque transmission mechanism) 5A, therefore, the assist torque of electrical motor 4 does not act on the rotation terminal 6D of mechanism, with the tooth bar at speed reduction gearing (assist torque transmission mechanism) 5A; Miniature gears side (downstream) is provided with the situation of the rotation terminal 6D of mechanism and compares, and can reduce to rotate the 6D of terminal mechanism, specifically, reduces hill holder 40, can miniaturization hill holder 40, the rotation terminal 6D of mechanism and driven steering device 100D.

Next, in the time of with reference to Figure 20 A～C, illustrate with steering handwheel 3 significantly twist operation to the situation of tooth bar terminal angular the handling maneuver angle and the action of dtc signal VT3.

Figure 20 A is the chart of time lapse of the operational ton of expression steering handwheel, Figure 20 B is the chart of time lapse of variation at the handling maneuver angle (dotted line) of the angle of rotation (sight line) of overlapping expression electrical motor and front-wheel, and Figure 20 C is the chart of time lapse of variation of the handling maneuver power (torque) of expression front-wheel.

Shown in Figure 20 A, if reverse steering handwheel 3 significantly, the state of " tooth bar end " about being operated to then turns torsion bar 111, therefore, also increases even the operational ton of steering handwheel 3 reaches the tooth bar end when time t1, restrains above the tooth bar end.Convergence is because rotate the protrusion 41a of the terminal 6D of mechanism, the cause of 43a butt.

Also have, shown in Figure 20 B, the handling maneuver angle (dotted line) of angle of rotation of electrical motor 4 (solid line) and front-wheel is before time t1, the big variation of the operational ton by steering handwheel 3 continues to increase, but when time t1, the handling maneuver angle of the angle of rotation of electrical motor 4 and front-wheel reaches the tooth bar terminal angular, therefore, and protrusion 41a, the 43a butt of the rotation terminal 6D of mechanism.Therefore, after time t1, the handling maneuver angle of the angle of rotation of electrical motor 4 and front-wheel does not increase the excess of stroke etc., does not depend on time t, and is constant with the tooth bar terminal angular.

Also have, shown in Figure 20 C, the handling maneuver power (torque) of front- wheel 1L, 1R rose before time t1, but after time t1, protrusion 41a, the 43a butt of the rotation terminal 6D of mechanism, therefore, the handling maneuver power (torque) of the handling maneuver power (torque) when not producing overtime t1 can prevent overladen generation.Also have, do not give Chi Tiao ﹠amp influence, for example impulsive force of the moment of inertia of electrical motor 4; Miniature gears.

According to present embodiment as can be known, as mentioned above, near reversing when the increasing operation tooth bar terminal angular of steering handwheel 3, in the big rotary manipulation before the tooth bar terminal angular, can avoid overload in miniature gears 7a, tooth bar 8a, rack shaft 8, tooth bar terminal 8b, shell end 11a, tooth bar housing section 11A generation, therefore, in fact below the miniature gears torque Tp that miniature gears 7a, tooth bar 8a transmit can be reduced to the identical degree of miniature gears torque Tp with less than tooth bar terminal angular common the time.

Thereby, can be reduced in the load (overload) that to imagine in the design of terminal 8b, tooth bar housing section 11A of miniature gears 7a, tooth bar 8a, bearing 3e, 3f, 3g or tooth bar, eliminated the size that in the past increases bearing in order to ensure the durability of these component parts, or the module of increase gear, increased in size, or the wall thickness of increase tooth bar housing section 11A, or strengthening rib etc. is set causes the weight of component parts to become big problem, can small-sized, lightweight component parts, improve lift-launch on the vehicle, the especially lift-launch on the dilly.

" variation of rotation terminal mechanism "

Rotation terminal mechanism among the present invention is not limited to described embodiment, for example, can carry out following various distortion.

(first variation of the 4th embodiment)

As shown in figure 21, the rotation terminal 6E of mechanism comprises: the promptly interior axle 51 of the division name among the rotation terminal 6E of mechanism of pinion shaft 7; Be disposed at the rotary actuator 53 in its outside; And then be disposed at its outside fixed stop 54.That is, in the present embodiment, the input shaft 3d (with reference to Figure 10) in first variation of first embodiment is replaced into pinion shaft 7, and in addition, structure is substantially the same, and the repetitive description thereof will be omitted.

Shown in Figure 21 (a), steering handwheel 3 is positioned under the situation of center position, and with respect to protrusion 54a, protrusion 53a is positioned at 180 ° of opposite senses.

Rack shaft 8 is handled by a left side of making, under the state of " the left tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, shown in Figure 21 (b), protrusion 53a is upwards pressing anticlockwise direction and protrusion 54a butt week, steering handwheel 3 further can not be rotated left.On the contrary, rack shaft 8 is handled by the right side of making, under the state of " the right tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, shown in Figure 21 (c), protrusion 53a week upwards in the direction of the clock with protrusion 54a butt, steering handwheel 3 further can not be rotated to the right.

According to the rotation terminal 6E of mechanism of this variation as can be known, compare with the rotation terminal 6D of mechanism of the 4th embodiment, till the tooth bar terminal angular of steering handwheel 3 allow operational ton scope (allowing the rotary manipulation scope) be about 540 °, therefore, can form the operational ton of the steering handwheel 3 in the common vehicle, all right.And then, by rotary actuator (Ring gear) 53 being replaced by the hill holder that changes the number of teeth, for example, can will allow that the operational ton scope is set in the scope of 450 ° or 600 °.That is, operational ton can be changed, various vehicles can be tackled corresponding to the steering handwheel of tooth bar terminal angular.

In this variation, also with the 4th embodiment in the same manner, even steerman has been in the state of tooth bar end and then switch has increased operation steering handwheel 3 from rack shaft 8, protrusion 53b, the 54a of the rotation terminal 6E of mechanism be butt also, stops rotation.

Thereby, can be reduced in the load (overload) that to imagine in the design of terminal 8b, tooth bar housing section 11A of miniature gears 7a, tooth bar 8a, bearing 3e, 3f, 3g or tooth bar, eliminated the size that in the past increases bearing in order to ensure the durability of these component parts, or the module of increase gear, increased in size, or the wall thickness of increase tooth bar housing section 11A, or strengthening rib etc. is set causes the weight of component parts to become big problem, can small-sized, lightweight component parts, improve lift-launch on the vehicle, the especially lift-launch on the dilly.

(second variation of the 4th embodiment)

Figure 22 has been to use the schematic perspective view of rotation terminal mechanism of second variation of planetary gear reduction unit.As shown in figure 22, in the present embodiment, be to be provided with the different this point in position of rotating terminal mechanism with the second variation difference of first embodiment, thereby, except input shaft 3d (with reference to Figure 11) is replaced into the pinion shaft 7, structure is substantially the same, and the repetitive description thereof will be omitted.

As speed reduction gearing 55, use the planet-gear speed reducer unit, the rotation terminal 6E ' of mechanism can be set to the spigot shaft coaxle with cap 13A thus, can reduce to rotate the 6E ' of terminal mechanism radially.And then when protrusion 57b and protrusion 58b butt, the load that puts on protrusion 57b is shared planetary wheel 57 separately by protrusion 57a, therefore, can stand the big load of situation than the rotation terminal 6E of mechanism of second variation.Correspondingly the terminal 6E ' of mechanism is rotated in miniaturization.

(the 3rd variation of the 4th embodiment)

Figure 23 is the schematic top plan view of the rotation terminal mechanism of the 3rd variation.Shown in Figure 23,24, in the present embodiment, be to be provided with the different this point in position of rotation terminal mechanism with the difference of the 3rd variation (with reference to Figure 12) of first embodiment, thereby, except input shaft 3d (with reference to Figure 13 B) is replaced into the pinion shaft 7, structure is substantially the same, omits repeat specification.

Expression in Figure 23 (a): steering handwheel 3 is positioned under the situation of center position, and with respect to protrusion 63c, 65c, protrusion 62a is positioned at the situation of axial central authorities.Expression in Figure 23 (b): rack shaft 8 is handled by a left side of making, under the state of " the left tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, protrusion 62a week upwards by from above anticlockwise direction and protrusion 65c butt under the situation of observing, can not be with steering handwheel 3 further rotation left.In Figure 23 (c), rack shaft 8 is handled by the right side of making, under the state of " the right tooth bar end " of terminal 8b of tooth bar and shell end 11a butt, protrusion 62a week upwards by from above clockwise direction and protrusion 63c butt under the situation of observing, can not be with steering handwheel 3 further rotation to the right.

In this variation, also with the 4th embodiment in the same manner, steerman further increases twist operation steering handwheel 3 from the state that rack shaft 8 has been in the tooth bar end, rotary manipulation is rotated the 6F of terminal mechanism to be stoped.

Its result, with the 4th embodiment in the same manner, can be reduced in miniature gears 7a, tooth bar 8a, bearing 3e, 3f, the terminal 8b of 3g or tooth bar, the load (overload) that should imagine in the design of tooth bar housing section 11A, eliminated the size that in the past increases bearing in order to ensure the durability of these component parts, or the module of increase gear, increased in size, or the wall thickness of increase tooth bar housing section 11A, or strengthening rib etc. is set causes the weight of component parts to become big problem, can be small-sized, the lightweight component parts improves the lift-launch on the vehicle, especially the lift-launch on the dilly.

The driven steering device 100D of the 4th embodiment is as torque sensor, and the addendum modification up and down that angular transformation is a slide block 115 that turns with torsion bar 111 detects its addendum modification with magnetic test coil 114A, 114B, output torque signal VT3, but be not limited to this.

" the 5th embodiment "

Secondly, in the time of with reference to Figure 25, the driven steering device of the 5th embodiment of the present invention is described.

As shown in figure 25, the driven steering device 100E of present embodiment is except the driven steering device 100C of the position of rotation terminal mechanism and the 3rd embodiment (with reference to Figure 15) is different, and structure is substantially the same, and the repetitive description thereof will be omitted.

In post housing 15, dispose torque sensor 120, rotation terminal mechanism 6, bearing 3i, gear on worm 5b, bearing 3j successively and accommodate.

That is, in the present embodiment, also with the 4th embodiment in the same manner, rotation terminal mechanism 6 axial locations at steering-wheel spindle 3a are disposed at torque sensor 120 and gear on worm 5b (between speed reduction gearing (assist torque transmission mechanism) 5A.

Also have, in Figure 25, the described rotation terminal 6D of mechanism of rotation terminal mechanism 6 representatives, 6E, 6E ', 6F and represent use arbitrary rotation terminal 6D of mechanism, 6E, 6E ', 6F also can.

According to present embodiment as can be known, with the 4th embodiment and variation thereof in the same manner, steerman has been in the state of tooth bar end and then has switched from rack shaft 8 increases operation steering handwheel 3, also stops the rotary manipulation of rotation terminal mechanism 6.

In addition, rotation terminal mechanism 6 is set near steering handwheel 3, therefore, regulates the sensor and the sensor correspondence of rotating terminal mechanism 6 of the steering-wheel spindle 3a of steering handwheel 3 easily.

Thereby, can be reduced in the load (overload) that to imagine in the design of terminal 8b, tooth bar housing section 11A of miniature gears 7a, tooth bar 8a, bearing 3e, 3f, 3g or tooth bar, eliminated the size that in the past increases bearing in order to ensure the durability of these component parts, or the module of increase gear, increased in size, or the wall thickness of increase tooth bar housing section 11A, or strengthening rib etc. is set causes the weight of component parts to become big problem, can small-sized, lightweight component parts, improve lift-launch on the vehicle, the especially lift-launch on the dilly.

Also have, above-mentioned embodiment and these variation all in, illustrated and to have rotated the situation that terminal mechanism is arranged at the part (input shaft 3d or steering-wheel spindle 3a) between steering handwheel 3 and the pinion shaft 7, but rotation terminal mechanism is arranged on the pinion shaft 7 and also can.

Claims (9)

1. driven steering device, it possesses: operating parts; At least basis is by the electrical motor that produces assist torque from the manipulation torque that input produced of described operating parts; The steering system that possesses the front-wheel of pinion shaft, described driven steering device is characterized in that the steering system transmission of described assist torque to described front-wheel,

Be provided with rotation terminal mechanism between described operating parts and pinion shaft, this rotation terminating machine is configured to the action terminal of described operating parts.

2. driven steering device according to claim 1 is characterized in that,

Described rotation terminal mechanism has speed reduction gearing, and the rotary manipulation scope of allowing by the described operating parts of described action terminal limitations is changed.

3. driven steering device according to claim 1 is characterized in that,

Also possess: detect the torque sensor of described manipulation torque,

Described rotation terminal mechanism is arranged between described operating parts and the described torque sensor.

4. driven steering device according to claim 1 is characterized in that,

Also possess: detect the torque sensor of described manipulation torque,

The steering system of described front-wheel also possesses the assist torque transmission mechanism,

Described rotation terminal mechanism is arranged between described torque sensor and the assist torque transmission mechanism.

5. driven steering device according to claim 2 is characterized in that,

Described rotation terminal mechanism comprises:

Input shaft with external gear, it transmits the rotation from the S. A. of described operating parts;

Belt gear, it has the external gear ingear inner gear with described input shaft, and is provided with first protrusion at outer circumferential side;

The fixed part of ring-type, it surrounds described belt gear,

The external gear of described input shaft and the inner gear of described belt gear constitute described speed reduction gearing,

Interior all sides at described fixed part are provided with second protrusion that limits the rotation of described first protrusion with the described first protrusion butt.

6. driven steering device according to claim 2 is characterized in that,

Described rotation terminal mechanism comprises:

As the planet-gear speed reducer unit of described speed reduction gearing, it possesses outer ring gear, (a plurality of) planetary wheel, pinion carrier and sun gear;

Fixed part, its fixing described outer ring gear,

Be provided with first protrusion in described pinion carrier,

From the rotation of the S. A. of described operating parts to described sun gear transmission,

Be provided with second protrusion that limits the rotation of described first protrusion with the described first protrusion butt at described fixed part or described outer ring gear.

7. driven steering device according to claim 2 is characterized in that,

Described rotation terminal mechanism comprises:

Threaded portion with external screw thread, it transmits the rotation from the S. A. of described operating parts;

First hill holder of ring-type, it is fixed in described threaded portion, and is provided with first protrusion at outer circumferential side;

Second hill holder, it has and described threaded portion ingear negative thread, is disposed at the top of described first hill holder, and is provided with second protrusion with the described first protrusion butt in its lower face side;

The 3rd hill holder, it has and described threaded portion ingear negative thread, is disposed at the below of described first hill holder, and face side is provided with the 3rd protrusion with the described first protrusion butt thereon;

Guide member, the rotation that it stops described second and third hill holder makes described second and third hill holder along the moving axially of described threaded portion,

Described threaded portion, described second hill holder, described the 3rd hill holder and described guide member constitute described speed reduction gearing.

8. driven steering device according to claim 3 is characterized in that,

Described torque sensor is a magnetostrictive torque sensor.

9. driven steering device according to claim 4 is characterized in that,

Described torque sensor is a magnetostrictive torque sensor.

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