CN104401387B

CN104401387B - No-load voltage ratio tooth bar and power steering stgear

Info

Publication number: CN104401387B
Application number: CN201410596957.7A
Authority: CN
Inventors: 任培; 付松; 邹理炎; 张宝义; 虞忠潮
Original assignee: HANGZHOU SHIBAO AUTO STEERING GEAR CO Ltd
Current assignee: HANGZHOU SHIBAO AUTO STEERING GEAR CO Ltd
Priority date: 2014-10-29
Filing date: 2014-10-29
Publication date: 2016-08-24
Anticipated expiration: 2034-10-29
Also published as: CN104401387A

Abstract

The present invention relates to the electronic-controlled power steering parts of motor vehicle, disclose a kind of no-load voltage ratio tooth bar, at least include gear teeth I and the gear teeth II adjacent with gear teeth I；Described gear teeth I and gear teeth II and meshed gear are respectively provided with different transmission speed ratio I_min、I_max；The flank of tooth of the close described gear teeth II of described gear teeth I has order can be at the constant interval { I of transmission speed ratio I with described no-load voltage ratio tooth bar and described gear_min,I_maxThe tooth surface shape seamlessly transitted between }；The radial section of the described flank of tooth is the envelope that described gear moves relative to described no-load voltage ratio tooth bar with movement locus X.It is an advantage of the current invention that gear transitions smooth between different transmission speed ratios, stable drive, can preferably eliminate the catching phenomenon during no-load voltage ratio.

Description

No-load voltage ratio tooth bar and power steering stgear

Technical field

The present invention relates to the electronic-controlled power steering parts of motor vehicle, particularly to a kind of no-load voltage ratio tooth bar and use this no-load voltage ratio tooth bar Power steering stgear.

Background technology

Truck steering is generally equipped with recirculating ball power steering gear or other similar power steering gears, There is provided power steering when driving, the output shaft of steering gear and rack piston are wheel and rack transmissions, and output shaft is also known as rocking arm Axle, its number of teeth generally only three, this tooth is also called rocker arm shaft fan tooth.The most commonly used design is the rack-and-pinion of standard Transmission, although this design energy driving torque and mechanical movement, but time actually used, it is desirable to along with the increase of rocker arm shaft corner, Speed ratio to be also gradually increased, and has good handling when driver motor turning meeting automobile.Use full-height tooth The fan tooth of design of wheel rack-driving and tooth bar, its speed ratio is constant, it is clear that cannot meet this requirement, and existing no-load voltage ratio skill Art, there is the rough point of flex point, causes transmission unsmooth, be susceptible to turn to card in its speed ratio variation pattern at Turn Ratio Changing Stagnant.Therefore prior art is the most immature.Fig. 3 illustrates in prior art, during variable rack is meshed with gear, and transmission The change schematic diagram of the rotational angle of speed ratio and gear, it may be seen that at flex point, its transition is the most unstable, shows During actually used, operator can be clearly felt that vibrations when turning to, and catching phenomenon occurs.

Thus, it is necessary to for the shortcoming of prior art, a kind of no-load voltage ratio tooth with new structure is proposed targetedly Bar.

Summary of the invention

To there is transmission during transmission speed ratio unstable changing to the present invention is directed to prior art medium power steering gear, holds It is easily generated the shortcoming turning to clamping stagnation, it is provided that a kind of no-load voltage ratio tooth bar and power steering stgear, can be in the process changing transmission speed ratio In, it is achieved smooth transition.

For achieving the above object, the present invention can take following technical proposals:

A kind of no-load voltage ratio tooth bar, at least includes gear teeth I and the gear teeth II adjacent with gear teeth I；

Described gear teeth I and gear teeth II and meshed gear are respectively provided with different transmission speed ratio I_min、I_max；

The flank of tooth of the close described gear teeth II of described gear teeth I has the transmission speed of order and described no-load voltage ratio tooth bar with described gear Can be at constant interval { I than I_min,I_maxThe tooth surface shape seamlessly transitted between }；

The radial section of the described flank of tooth is the envelope that described gear moves relative to described no-load voltage ratio tooth bar with movement locus X Line, described movement locus X is the described no-load voltage ratio tooth bar displacement relative to described gear；

Described movement locus X at least includes flex point I, flex point II and flex point III, and described flex point I and flex point II are successively With described constant interval { I_min,I_maxEnd value I_minAnd I_maxCorresponding, described flex point III be flex point I and flex point II it Between any point；

At described constant interval { I_min,I_maxIn }, transmission speed ratio I=f (θ), wherein, θ is that described gear is along the rail that moves Mark X moves the angle turned over；

At described constant interval { I_min,I_maxIn }, close to end value I_minAnd I_maxPlace, it is bent that described f (θ) is respectively secondary Line.

In embodiments of the invention, described flex point III is described constant interval { I_min,I_maxIn }, transmission speed ratio I changes Midpoint；Near flex point II, described f (θ) is conic section.

In embodiments of the invention, described f (θ), with flex point III as symmetrical centre, levels off to described flex point symmetrically III。

In embodiments of the invention, described transmission speed ratioDescribed transmission speed ratio I_maxSpan For 1.1I_minTo 1.3I_min, wherein, described M is the modulus of described gear, and described Z is the full circle number of teeth of described gear.

In embodiments of the invention, described movement locus X is obtained by the following formula:

X = {\begin{matrix} I_{\min} \cdot θ, (0 \leq θ < θ_{1}) \\ I_{\min} \cdot θ_{1} + (\frac{a_{1} θ^{3}}{3} + b_{1} θ) - (\frac{a_{1} θ_{1}^{3}}{3} + b_{1} θ_{1}), (θ_{1} \leq θ < θ_{2}) \\ I_{\min} \cdot θ_{1} + (\frac{a_{1} θ_{2}^{3}}{3} + b_{1} θ) - (\frac{a_{1} θ_{1}^{3}}{3} + b_{1} θ_{1}) + \\ \frac{2}{3 \sqrt{a_{2}}} {(θ - b_{2})}^{\frac{3}{2}} - \frac{2}{3 \sqrt{a_{2}}} {(θ_{2} - b_{2})}^{\frac{3}{2}}, (θ_{2} \leq θ < θ_{3}) \\ I_{\min} \cdot θ_{1} + (\frac{a_{1} θ_{2}^{3}}{3} + b_{1} θ) - (\frac{a_{1} θ_{1}^{3}}{3} + b_{1} θ_{1}) + \\ \frac{2}{3 \sqrt{a_{2}}} {(θ_{3} - b_{2})}^{\frac{3}{2}} - \frac{2}{3 \sqrt{a_{2}}} {(θ_{2} - b_{2})}^{\frac{3}{2}} + I_{\max} (θ - θ_{3}), (θ_{3} \leq θ \leq θ_{\max}) \end{matrix},

Wherein, θ₁、θ₂And θ₃It is followed successively by the angle that described gear turns over through flex point I, flex point II, flex point III, (a₁, b₁) and (a₂, b₂) be followed successively by f (θ) and level off to the parameter of flex point I and flex point II.

In embodiments of the invention, described gear is standard involute gear.

In embodiments of the invention, described gear is fan tooth.

According to the power steering stgear obtained by above-mentioned no-load voltage ratio tooth bar.

In embodiments of the invention, described power steering stgear is recirculating ball power steering gear.

Recirculating ball-type steering is mainly made up of parts such as screw rod, nut, steering gear housing and many small balls, so-called Circulating ball refers to is exactly these small balls, they are placed in the pipeline liquid injecting device between nut and screw rod, play nut Sliding friction between screw rod is changed into the effect of the less rolling friction of resistance, when being secured together with wheel steering tubing string Screw rod rotate after, screw rod promote nut move up and down, nut by gear drive pitman arm back and forth shake from And realize turning to.In the middle of this process, the rolling that those small balls just move in circles in airtight pipeline, so this turn It is thus referred to as recirculating ball-type steering to device.

The present invention has a following notable technique effect:

It is capable of smoothly changing the transmission speed ratio of gear, makes gear keep smooth at flex point, keep transmission process Steady, reduce the catching phenomenon occurred when turning to.

Accompanying drawing explanation

Fig. 1 is the changable driving speed ratio change schematic diagram of no-load voltage ratio tooth bar and meshed gear.

Fig. 2 is the structural representation of no-load voltage ratio tooth bar and meshed gear.

Fig. 3 is the changable driving speed ratio change schematic diagram between existing rack and pinion.

Fig. 4 is the relation schematic diagram of the gear displacement relative to no-load voltage ratio tooth bar and rotational angle.

Fig. 5 is that the envelope during gear is meshed with no-load voltage ratio tooth bar forms schematic diagram.

Detailed description of the invention

Below in conjunction with embodiment, the present invention is described in further detail.

Embodiment 1

A kind of no-load voltage ratio tooth bar, as Figure 1-5, at least includes gear teeth I100 and the gear teeth adjacent with gear teeth I100 II200。

As in figure 2 it is shown, described gear teeth I100 and gear teeth II200 and meshed gear 300 are respectively provided with difference Transmission speed ratio I_min、I_max；The gear teeth I100 and gear teeth II200 of no-load voltage ratio tooth bar have different tooth surface shapes, and gear 300 On gear teeth meshing after, during no-load voltage ratio tooth bar engaged transmission, sequentially passing through gear teeth I100 and gear teeth II200 After, transmission speed ratio I is by I_minSmoothly fade to I_max, to realize the function of no-load voltage ratio.

In order to realize the above-mentioned function smoothly changing transmission speed ratio, the close described gear teeth II200 of described gear teeth I100 The flank of tooth 101 there is the transmission speed ratio of order and described no-load voltage ratio tooth bar and described gear 300 can be at constant interval { I_min,I_maxIt Between the tooth surface shape that seamlessly transits.

Specifically, the radial section of the described flank of tooth 101 be described gear 300 with movement locus X relative to described no-load voltage ratio The envelope that tooth bar moves, as shown in Figure 4, described movement locus X is the displacement relative to described gear 300 of the described no-load voltage ratio tooth bar Amount；

Described movement locus X at least includes flex point I, flex point II and flex point III, and described flex point I and flex point II are successively With described constant interval { I_min,I_maxEnd value I_minAnd I_maxCorresponding, described flex point III be flex point I and flex point II it Between any point.As it is shown in figure 1, when gear 300 makees the displacement relative to no-load voltage ratio tooth bar along movement locus X, at gear 300 The constant interval { 0, θ of rotational angle₁In }, the transmission speed ratio between gear 300 and no-load voltage ratio tooth bar is constant for I_min,+, tooth Wheel 300 arrives flex point III along movement locus X.Further, gear 300 displacement is after flex point III, at constant interval {θ₃,θ₂In }, transmission speed ratio continues smoothly to increase, until the rotational angle of gear 300 reaches θ according to=f ' (θ)₂, now, Gear 300 arrives flex point II along movement locus X, and now transmission speed ratio arrives I_max, and keep this transmission speed ratio to be rotated further, Make transmission transition steady, the phenomenon of the clamping stagnation in minimizing transmission process.

It is pointed out that the most all types of tooth surface shape all can reduce catching phenomenon when turning to.Although Make the transition that the rotational angle of transmission speed ratio I and gear 300 smooths according to the relation of I=f (θ) at flex point, but obtained by experiment, During turning to, still there will be slight shake and the phenomenon of a little clamping stagnation, it is therefore desirable to find more excellent further Tooth surface shape.

Preferred, at described constant interval { I as one_min,I_maxIn }, transmission speed ratio I=f (θ), wherein, θ is described tooth Wheel 300 moves, along movement locus X, the angle turned over.Especially, at described constant interval { I_min,I_maxIn }, close to end value I_min And I_maxPlace, described f (θ) is conic section, specifically, { 0, θ₁, described conic section is I=a₁θ²+b₁.In flex point Near III, described f (θ), with flex point III as symmetrical centre, levels off to described flex point III symmetrically.Further, described flex point III is described constant interval { I_min,I_maxIn }, the midpoint of transmission speed ratio I change；Near flex point II, transmission speed ratioAfter gear 300 is moved across flex point III, at { θ₁,θ₂In, described conic section be θ= a₂I²+b₂.Experiment shows, after using conic section, the transition between no-load voltage ratio rack and pinion is the most steady, and catching phenomenon is complete Disappear.

Described transmission speed ratioDescribed transmission speed ratio I_maxSpan be preferably 1.1I_minExtremely 1.3I_min, in this range, transmission efficiency is higher, and wherein, described M is the modulus of described gear 300, and described Z is described gear The full circle number of teeth of 300.

Further, show that gear 300 relative to the relative displacement of no-load voltage ratio tooth bar is

Δ X = \{\begin{matrix} Δ θ \cdot I_{m i n}, (0 \leq θ < θ_{1}) \\ (a_{1} θ^{2} + b_{1}) \cdot Δ θ, (θ_{1} \leq θ < θ_{2}) \\ \sqrt{\frac{θ - b_{2}}{a_{2}}} \cdot Δ θ, (θ_{2} \leq θ < θ_{3}) \\ I_{\max} \cdot Δ θ, (θ_{3} \leq θ \leq θ_{\max}) \end{matrix}

Described movement locus X is at least obtained by the following formula:

X = {\begin{matrix} I_{\min} \cdot θ, (0 \leq θ < θ_{1}) \\ I_{\min} \cdot θ_{1} + (\frac{a_{1} θ^{3}}{3} + b_{1} θ) - (\frac{a_{1} θ_{1}^{3}}{3} + b_{1} θ_{1}), (θ_{1} \leq θ < θ_{2}) \\ I_{\min} \cdot θ_{1} + (\frac{a_{1} θ_{2}^{3}}{3} + b_{1} θ) - (\frac{a_{1} θ_{1}^{3}}{3} + b_{1} θ_{1}) + \\ \frac{2}{3 \sqrt{a_{2}}} {(θ - b_{2})}^{\frac{3}{2}} - \frac{2}{3 \sqrt{a_{2}}} {(θ_{2} - b_{2})}^{\frac{3}{2}}, (θ_{2} \leq θ < θ_{3}) \\ I_{\min} \cdot θ_{1} + (\frac{a_{1} θ_{2}^{3}}{3} + b_{1} θ) - (\frac{a_{1} θ_{1}^{3}}{3} + b_{1} θ_{1}) + \\ \frac{2}{3 \sqrt{a_{2}}} {(θ_{3} - b_{2})}^{\frac{3}{2}} - \frac{2}{3 \sqrt{a_{2}}} {(θ_{2} - b_{2})}^{\frac{3}{2}} + I_{\max} (θ - θ_{3}), (θ_{3} \leq θ \leq θ_{\max}) \end{matrix},

Wherein, θ is that described gear 300 moves the angle turned over, θ along movement locus X₁、θ₂And θ₃It is followed successively by described tooth The angle that wheel 300 turns over through flex point I, flex point II, flex point III, (a₁,b₁) and (a₂,b₂) it is followed successively by described movement locus X levels off to the parameter of conic section of flex point I and flex point II.

After obtaining the movement locus X of said gear 300, by nibbling described gear 300 mutually with described no-load voltage ratio tooth bar The gear teeth closed with after CAE technology to drawing, according to described gear 300 along movement locus X move time, when gear 300 is in difference During position, draw contour shape and the movement locus of the gear teeth of its engagement one by one, and thus obtain envelope, as it is shown in figure 5, This envelope is the profile of tooth of the flank of tooth 101 of no-load voltage ratio tooth bar.

Further, described gear 300 can be standard involute gear, it is also possible to for the gear of other shapes.

Further, described gear 300 is fan tooth, and a part for the most complete gear also may be used.

Embodiment 2

A kind of power steering stgear, is provided with the dynamic of the no-load voltage ratio tooth bar described in Application Example 1 and the gear that is matched therewith Power steering gear.

Preferred as one, described power steering stgear is recirculating ball power steering gear.

Further experiment shows, the power steering stgear described in the present embodiment, including recirculating ball power steering gear, transmission Extremely steady, velocity variations smooths, and compares the tooth surface shape that other curves obtain, has stable transmission, turns to happy advantage.

In a word, the foregoing is only presently preferred embodiments of the present invention, all equalizations made according to scope of the present invention patent Change and modification, all should belong to the covering scope of patent of the present invention.

Claims

1. a no-load voltage ratio tooth bar, it is characterised in that at least include gear teeth I (100) and the gear teeth II adjacent with gear teeth I (100) (200)；

Described gear teeth I (100) and gear teeth II (200) and meshed gear (300) are respectively provided with different transmission speed Compare I_min、I_max；

The flank of tooth (101) of the close described gear teeth II (200) of described gear teeth I (100) has order with described no-load voltage ratio tooth bar with described The transmission speed ratio I of gear (300) can be at constant interval { I_min,I_maxThe tooth surface shape seamlessly transitted between }；Described

The radial section of the flank of tooth (101) is the envelope that described gear (300) moves relative to described no-load voltage ratio tooth bar with movement locus X Line, described movement locus X is the described no-load voltage ratio tooth bar displacement relative to described gear (300)；Described movement locus X at least wraps Include flex point I, flex point II and flex point III, described flex point I and flex point II successively with described constant interval { I_min,I_maxEnd Value I_minAnd I_maxCorresponding, described flex point III is any point between flex point I and flex point II；

At described constant interval { I_min,I_maxIn }, transmission speed ratio IIf (θ), wherein, θ is that described gear (300) is along the rail that moves Mark X moves the angle turned over；

At described constant interval { I_min,I_maxIn }, close to end value I_minAnd I_maxPlace, described f (θ) is respectively conic section.

No-load voltage ratio tooth bar the most according to claim 1, it is characterised in that described flex point III is described constant interval { I_min, I_maxIn }, the midpoint of transmission speed ratio I change；Near flex point II, described f (θ) is conic section.

No-load voltage ratio tooth bar the most according to claim 2, it is characterised in that described f (θ) is with flex point III as symmetrical centre, symmetrical Level off to described flex point III.

No-load voltage ratio tooth bar the most according to claim 1, it is characterised in that described transmission speed ratioDescribed biography Dynamic speed ratio I_maxSpan be 1.1I_minTo 1.3I_min, wherein, described M is the modulus of described gear (300), and described Z is institute State the full circle number of teeth of gear (300).

No-load voltage ratio tooth bar the most according to claim 1, it is characterised in that described movement locus X is obtained by the following formula:

X = \{\begin{matrix} I_{\min} \cdot θ, (0 \leq θ < θ_{1}) \\ I_{m i n} \cdot θ_{1} + (\frac{a_{1} θ^{3}}{3} + b_{1} θ) - (\frac{a_{1} θ_{1}^{3}}{3} + b_{1} θ_{1}), (θ_{1} \leq θ < θ_{2}) \\ I_{\min} \cdot θ_{1} + (\frac{a_{1} θ^{3}}{3} + b_{1} θ) - (\frac{a_{1} θ_{1}^{3}}{3} + b_{1} θ_{1}) + \\ \frac{2}{3 \sqrt{a_{2}}} {(θ - b_{2})}^{\frac{3}{2}} - \frac{2}{3 \sqrt{a_{2}}} {(θ_{2} - b_{2})}^{\frac{3}{2}}, (θ_{2} \leq θ < θ_{3}) \\ I_{\min} \cdot θ_{1} + (\frac{a_{1} θ_{2}^{3}}{3} + b_{1} θ) - (\frac{a_{1} θ_{1}^{3}}{3} + b_{1} θ_{1}) + \\ \frac{2}{3 \sqrt{a_{2}}} {(θ_{3} - b_{2})}^{\frac{3}{2}} - \frac{2}{3 \sqrt{a_{2}}} {(θ_{2} - b_{2})}^{\frac{3}{2}} + I_{\max} (θ - θ_{3}), (θ_{3} \leq θ \leq θ_{m a x}) \end{matrix},

Wherein, θ₁、θ₂And θ₃It is followed successively by the angle that described gear (300) turns over through flex point I, flex point II, flex point III, (a₁,b₁) and (a₂,b₂) be followed successively by f (θ) and level off to the parameter of flex point I and flex point II.

No-load voltage ratio tooth bar the most according to claim 1, it is characterised in that described gear (300) is standard involute gear.

No-load voltage ratio tooth bar the most according to claim 1, it is characterised in that described gear (300) is fan tooth.

8. according to the power steering stgear obtained by the arbitrary described no-load voltage ratio tooth bar of the claims 1-7.

Power steering stgear the most according to claim 8, it is characterised in that described power steering stgear is ball-and-nut power steering Device.