JP4123023B2 - Differential support mechanism - Google Patents

Description

【００１２】
ただし、
ｍ11＝ｍ
ｍ12＝ｍＬGx
ｍ13＝−ｍＬGy
ｍ22＝Ｉyy＋ｍＬGxＬGx
ｍ23＝−Ｉxy−ｍＬGxＬGy
ｍ33＝Ｉyy＋ｍＬGyＬGy
ｋ11＝ｋfr＋ｋfl＋ｋrr＋ｋrl
ｋ12＝ｋflＬflx ＋ｋfrＬfrx −ｋrlＬrlx −ｋrrＬrrx
ｋ13＝−ｋflＬfly ＋ｋfrＬfry −ｋrlＬrly ＋ｋrrＬrry
ｋ22＝ｋflＬflx Ｌflx ＋ｋfrＬfrx Ｌfrx ＋ｋrlＬrlx Ｌrlx＋ｋrrＬrrx Ｌrrx
ｋ23＝−ｋflＬflx Ｌfly ＋ｋfrＬfrx Ｌfry ＋ｋrlＬrlx Ｌrly−ｋrrＬrrx Ｌrry
ｋ33＝ｋflＬfly Ｌfly ＋ｋfrＬfry Ｌfry ＋ｋrlＬrly Ｌrly＋ｋrrＬrry Ｌrry
であり、また、「・・」は２階時間微分を表す。
【００１３】
（１）式を展開すると、次式が得られる。
【数２】

【００１４】
ここで、時間をｔ、デフキャリヤ４の振動周波数ω、軸ｚ方向におけるデフキャリヤ４の変位振幅をＡz 、軸ｙを中心としたデフキャリヤ４の回転振動の角変位振幅をＡy 、軸ｘを中心としたデフキャリヤ４の回転振動の角変位振幅をＡxとして、軸ｚ、角変位θy 及び角変位θx をそれぞれ周期関数で表せば、
Ｚ＝Ａz sin ωｔ、θy ＝Ａy sin ωｔ、θx ＝Ａx sin ωｔ
となるので、これらを（２）式に代入すると、次式が得られる。
【００１５】
【数３】

【００１６】
周知の周波数応答関数θx ／Ｔは（３）式を解くことにより次式が得られる。θx ／Ｔ＝〔ωωωω｛ρ（ｍ11ｍ23−ｍ12ｍ13）＋（ｍ12ｍ12−ｍ11ｍ22）｝＋ωω｛ρ（ｋ12ｍ13＋ｋ13ｍ12−ｋ11ｍ23−ｋ23ｍ11）
＋（ｋ11ｍ22＋ｋ22ｍ11−２ｋ12ｍ12）｝＋｛ρ（ｋ11ｋ23−ｋ12ｋ13）
＋（ｋ12ｋ12−ｋ11ｋ22）｝〕／
〔（−ωωｍ11＋ｋ11）｛（−ωωｍ23＋ｋ23）（−ωωｍ23＋ｋ23）
−（−ωωｍ22＋ｋ22）（−ωωｍ33＋ｋ33）｝
＋（−ωωｍ12＋ｋ12）｛（−ωωｍ12＋ｋ12）（−ωωｍ33＋ｋ33）
−（−ωωｍ23＋ｋ23）（−ωωｍ13＋ｋ13）｝
＋（−ωωｍ13＋ｋ13）｛（−ωωｍ22＋ｋ22）（−ωωｍ13＋ｋ13）
−（−ωωｍ12＋ｋ12）（−ωωｍ23＋ｋ23）｝〕 （４）
【００１７】
ωの値に関係なく常にθx ／Ｔ＝０が成立するためには、（４）式における４次のω及び２次のωの各係数と定数項とが０でなければならない。
すなわち、
ρ（ｍ11ｍ23−ｍ12ｍ13）＋（ｍ12ｍ12−ｍ11ｍ22）＝０ （５）
ρ（ｋ12ｍ13＋ｋ13ｍ12−ｋ11ｍ23−ｋ23ｍ11）
＋（ｋ11ｍ22＋ｋ22ｍ11−２ｋ12ｍ12）＝０ （６）
ρ（ｋ11ｋ23−ｋ12ｋ13）＋（ｋ12ｋ12−ｋ11ｋ22）＝０ （７）
【００１８】
（５）式、（６）式、（７）式にそれぞれ上記定義を当てはめると、それぞれ次式が成立する。
ρＩxy＋Ｉyy＝０ （８）
ρ〔ｋfl｛（Ｌflx −ＬGx）（Ｌfly −ＬGy）ｍ＋Ｉxy｝
＋ｋfr｛−（Ｌfrx −ＬGx）（Ｌfry ＋ＬGy）ｍ＋Ｉxy｝
＋ｋrl｛−（Ｌrlx ＋ＬGx）（Ｌrly −ＬGy）ｍ＋Ｉxy｝
＋ｋrr｛（Ｌrrx ＋ＬGx）（Ｌrry ＋ＬGy）ｍ＋Ｉxy｝〕
＋ｋfl｛（Ｌflx −ＬGx）（Ｌflx −ＬGx）ｍ＋Ｉyy｝
＋ｋfr｛（Ｌfrx −ＬGx）（Ｌfrx −ＬGx）ｍ＋Ｉyy｝
＋ｋrl｛（Ｌrlx ＋ＬGx）（Ｌrlx ＋ＬGx）ｍ＋Ｉyy｝
＋ｋrr｛（Ｌrrx ＋ＬGx）（Ｌrrx ＋ＬGx）ｍ＋Ｉyy｝＝０ （９）
ρ〔ｋflｋfr（Ｌfrx −Ｌflx ）（Ｌfry ＋Ｌfly ）
＋ｋflｋrl（Ｌrlx ＋Ｌflx ）（Ｌrly −Ｌfly ）
−ｋflｋrr（Ｌflx ＋Ｌrrx ）（Ｌfly ＋Ｌrry ）
＋ｋfrｋrl（Ｌfrx ＋Ｌrlx ）（Ｌfry ＋Ｌrly ）
＋ｋfrｋrr（Ｌfrx ＋Ｌrrx ）（Ｌfry −Ｌrry ）
＋ｋrlｋrr（Ｌrlx −Ｌrrx ）（Ｌrly ＋Ｌrry ）〕
−｛ｋflｋfr（Ｌflx −Ｌfrx ）（Ｌflx −Ｌfrx ）
＋ｋflｋrl（Ｌflx ＋Ｌrlx ）（Ｌflx ＋Ｌrlx ）
＋ｋflｋrr（Ｌflx ＋Ｌrrx ）（Ｌflx ＋Ｌrrx ）
＋ｋfrｋrl（Ｌfrx ＋Ｌrlx ）（Ｌfrx ＋Ｌrlx ）
＋ｋfrｋrr（Ｌfrx ＋Ｌrrx ）（Ｌfrx ＋Ｌrrx ）
＋ｋrlｋrr（Ｌrlx −Ｌrrx ）（Ｌrlx −Ｌrrx ）｝＝０ （１０）
【００１９】
従って、
条件（イ）：Ｌflx ＝Ｌfrx ＝Ｌfx、
Ｌfly ＝Ｌfry ＝Ｌfy
条件（ロ）：ｋfl＝ｋfr＝ｋf
条件（ハ）：ｋrr＝０
を（１０）式に代入すれば、
２ｋf ｋrl（Ｌfx＋Ｌrlx ）｛ρＬrly −（Ｌfx＋Ｌrlx ）｝＝０
となるので、条件（イ）〜（ハ）と、
条件（ニ）：ρＬrly ＝Ｌfx＋Ｌrlx
とが満たされれば、（１０）式が成立する。
【００２０】
また、
条件（ホ）：ρＩxy＝−Ｉyy
が満たされれば、（８）式が成立する。
【００２１】
さらに、条件（イ）〜（ホ）と
条件（ヘ）：Ｌfx＝ρＬGy＋ＬGx
とが満たされれば、（９）式が成立する。
【００２２】
すなわち、
条件（イ）：ドライブシャフト１４の中心軸より車両前方（プロペラシャフト１３の側）でプロペラシャフト１３の中心軸の左右２個所にそれぞれ配置されたキャリヤ４の弾性支持点が、上記各中心軸との距離をそれぞれ等しくされている（２個所の弾性支持点がプロペラシャフト１３の中心軸を挟んで対称的に配置されている）。
条件（ロ）：上記左右２個所における弾性支持点のばね定数が等しい。
条件（ハ）：ドライブシャフト１４の中心軸より車両後方（プロペラシャフト１３の反対側）で車両前方に対しプロペラシャフト１３の中心軸の左方１個所にのみキャリヤ４の弾性支持点が配置される（プロペラシャフト１３の中心軸の右方にはキャリヤ４の弾性支持点が配置されていない）。
条件（ニ）：ρＬrly ＝Ｌfx＋Ｌrlx
条件（ホ）：ρＩxy＝−Ｉyy
条件（ヘ）：Ｌfx＝ρＬGy＋ＬGx
を成立させれば（デフ３の支持機構が図２に示されているように形成されれば）、軸ｘを中心としたデフキャリヤ４の回転変位がωの値に関係なく常に０となって、デフキャリヤ４にローリング共振現象が発生することを確実に防止することができることとなる。
【００２３】
また、上記した符号の定義において、
ｋ12＝ｋflＬflx ＋ｋfrＬfrx −ｋrlＬrlx −ｋrrＬrrx
に条件（イ）〜（ハ）と、
条件（ト）：２ｋf ／ｋrl＝Ｌrlx ／Ｌfx
とを代入すれば、ｋ12＝０となって、デフキャリヤ４のピッチング回転軸と軸ｙとが一致することとなるため、プロペラシャフト１３とドライブシャフト１４とのジョイント交点が大きくならないので、デフキャリヤ４の振動悪化を防止することができる。
すなわち、この実施形態例では、適正に選定された支持点９、１０、１１に、それぞれ適正に設定されたばね定数を有する、例えばゴム状弾性体を配置して、キャリヤ４が車体に対し上下方向に弾性支持（下方から支承、または、上方から懸架）されている。
【００２４】
上記実施形態例では、ドライブシャフト１４の中心軸より車両前方においてプロペラシャフト１３の中心軸の左右２個所でそれぞれキャリヤ４を弾性支持すると共に、ドライブシャフト１４の中心軸より車両後方において車両前方に対しプロペラシャフト１３の中心軸の左方１個所でキャリヤ４を弾性支持しているが、この支持機構を図３に示されているように、ドライブシャフト１４の中心軸より車両後方においてプロペラシャフト１３の中心軸の左右２個所でそれぞれキャリヤ４を弾性支持すると共に、ドライブシャフト１４の中心軸より車両前方において車両前方に対しプロペラシャフト１３の中心軸の右方１個所でキャリヤ４を弾性支持するようにし、
条件（チ）：Ｌrlx ＝Ｌrrx ＝Ｌrx、
Ｌrly ＝Ｌrry ＝Ｌry
条件（リ）：ｋrl＝ｋrr＝ｋr
条件（ヌ）：ｋfl＝０
を（１０）式に代入すれば、
２ｋfrｋr （Ｌfrx ＋Ｌrx）｛ρＬfry −（Ｌfrx ＋Ｌrx）｝＝０
となるので、条件（チ）〜（ヌ）と、
条件（ル）：ρＬfry ＝Ｌfrx ＋Ｌrx
とが満たされれば、（１０）式が成立する。
【００２５】
また、
条件（ホ）：ρＩxy＝−Ｉyy
が満たされれば、（８）式が成立する。
【００２６】
さらに、条件（ホ）、（チ）〜（ル）と
条件（ヲ）：Ｌrx＝−（ρＬGy＋ＬGx）
とが満たされれば、（９）式が成立する。
【００２７】
すなわち、
条件（チ）：ドライブシャフト１４の中心軸より車両後方（プロペラシャフト１３の反対側）でプロペラシャフト１３の中心軸の左右２個所にそれぞれ配置されたキャリヤ４の弾性支持点が、上記各中心軸との距離をそれぞれ等しくされている（２個所の弾性支持点がプロペラシャフト１３の中心軸を挟んで対称的に配置されている）。
条件（リ）：上記左右２個所における弾性支持点のばね定数が等しい。
条件（ヌ）：ドライブシャフト１４の中心軸より車両前方（プロペラシャフト１３の側）で車両前方に対しプロペラシャフト１３の中心軸の右方１個所にのみキャリヤ４の弾性支持点が配置される（プロペラシャフト１３の中心軸の左方にはキャリヤ４の弾性支持点が配置されていない）。
条件（ホ）：ρＩxy＝−Ｉyy
条件（ル）：ρＬfry ＝Ｌfrx ＋Ｌrx
条件（ヲ）：Ｌrx＝−（ρＬGy＋ＬGx）
を成立させれば（デフ３の支持機構が図３に示されているように形成されれば）、軸ｘを中心としたデフキャリヤ４の回転変位がωの値に関係なく常に０となって、デフキャリヤ４にローリング共振現象が発生することを確実に防止することができることとなる。
【００２８】
また、上記した符号の定義において、
ｋ12＝ｋflＬflx ＋ｋfrＬfrx −ｋrlＬrlx −ｋrrＬrrx
に条件（チ）〜（ヌ）と、
条件（ワ）：ｋfr／２ｋr ＝Ｌrx／Ｌfrx
とを代入すれば、ｋ12＝０となって、デフキャリヤ４のピッチング回転軸と軸ｙとが一致することとなるため、プロペラシャフト１３とドライブシャフト１４とのジョイント交点が大きくならないので、デフキャリヤ４の振動悪化を防止することができる。
すなわち、この実施形態例では、適正に選定された支持点１０、１１、１２に、それぞれ適正に設定されたばね定数を有する、例えばゴム状弾性体を配置して、キャリヤ４が車体に対し上下方向に弾性支持（下方から支承、または、上方から懸架）されている。
【００２９】
なお、上記各実施形態例において、図４に例示されているように、プロペラシャフト１３の一方の側のみに配置された弾性支持点Ｐを、支持点Ｐに対して車幅方向に対称的な位置の弾性支持点Ｐ1 、Ｐ2 に分割し、各支持点Ｐ1 、Ｐ2 のばね定数を支持点Ｐのばね定数の１／２とすれば、上記各実施形態例とそれぞれ同等の作用効果を奏することはいうまでもない。
【００３０】
また、上記各実施形態例は車両のリヤデフに関するものであるが、これらをそれぞれ車両の前後に逆配置してフロントデフに適用しても、上記各実施形態例とそれぞれ同等の作用効果を奏することができるものである。
【００３１】
【発明の効果】
本発明にかかるデフ支持機構においては、デフの弾性支持位置、各支持点のばね定数、デフの慣性モーメント及びデフの慣性乗積をそれぞれ適正に選定することにより、デフの振動を抑制して、車体の振動や異音の発生を防止することができるようになる。
【図面の簡単な説明】
【図１】デフ支持機構の概念的平面図。
【図２】本発明の実施形態例における概念的平面図。
【図３】本発明の他の実施形態例における概念的平面図。
【図４】本発明の他の実施形態例における概念的平面図。
【符号の説明】
１ 車両
３ デフ
４ キャリヤ
９、１０、１１、１２ 支持点
１３ プロペラシャフト
１４ ドライブシャフト
Ｇ 重心
Ｏ 原点[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a differential mechanism for left and right wheels in a vehicle, a so-called mechanism for supporting a differential.
[0002]
[Prior art]
The conventional differential support mechanism is generally configured to elastically support the differential carrier at four positions on the front, rear, left and right sides of the differential carrier so that the center of gravity of the differential carrier is substantially the center, but a propeller shaft to which driving force is transmitted from the engine, The differential is displaced up and down by the reaction force from the drive shafts that drive the left and right wheels, and is rotated and displaced in the roll direction and the pitch direction of the vehicle, respectively, and the center of rotation is the center axis of the propeller shaft and the drive shaft. If the rotation displacement and the rotation center deviation are large, the crossing angle between the center axis of the propeller shaft and the center axis of the drive shaft increases, causing vibrations and noise in the vehicle body. It was.
[0003]
In addition, what was described in the following patent document 1 is conventionally known as a front differential support structure of a vehicle.
[0004]
[Patent Document 1]
Japanese Patent No. 3011033
In this case, the front differential body is supported at two points on the front and rear sides that are equidistant from the axle center with respect to the axle center, and the axle center is on the opposite side of the vehicle width center. On the other hand, by supporting the differential tube at one point on the front side, the pitching resonance of the front differential is suppressed.
[0006]
[Problems to be solved by the invention]
The present invention is intended to effectively suppress rolling vibration generated in a vehicle differential by a differential support mechanism.
[0007]
[Means for Solving the Problems]
For this reason, the differential support mechanism according to the present invention elastically supports the differential in the vertical direction at three points, the two support points are symmetrical with respect to the propeller shaft, the spring constant is equal, and the other two support points The relative position with respect to one support point, the differential moment of inertia, the product of the differential inertia, and the spring constant of each support point are appropriately selected.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention shown in the drawings will be described with the same reference numerals given to the equivalent parts of the embodiments.
[0009]
In FIG. 1, the carrier 4 of the differential 3 for the left and right rear wheels 2 of the vehicle 1 is substantially in a horizontal plane at the front ends of the left and right front arms 5 and 6 and the left and right rear arms 7 and 8 with respect to the front of the vehicle 1. The driving force of the torque T transmitted from the propeller shaft 13 arranged in the vehicle longitudinal direction is arranged substantially perpendicular to the propeller shaft 13. It is assumed that the left and right rear wheels 2 are driven by being transmitted to the left and right drive shafts 14 with a differential ratio (reduction ratio) ρ.
[0010]
At this time,
xg: axis in the vehicle longitudinal direction passing through the center of gravity G of the differential 3 yg: axis in the vehicle width direction passing through the center of gravity G of the differential 3 x: center axis of the propeller shaft 13: center axis z of the drive shaft 14: axis x and axis The vertical axis Z passing through the intersection (origin) O of y: the displacement of the carrier 4 in the axis z direction θx: the angular displacement of the carrier 4 about the axis x (the angular displacement in the clockwise direction as viewed in the arrow direction of the axis x) )
θy: angular displacement of the carrier 4 about the axis y (angular displacement in the clockwise direction when viewed in the direction of the arrow on the axis y)
m: Mass of differential 3 Ixx: Moment of inertia of differential 3 about axis xg Iyy: Moment of inertia of differential 3 about axis yg Ixy: Product of inertia of differential 3 with respect to axis xg and axis yg LGx: Center of gravity G The distance in the direction of the axis x from the axis y to the axis y (the direction of the arrow of the axis x is positive and the sign is added)
LGy: Distance in the direction of the axis y from the center of gravity G to the axis x (the direction of the arrow of the axis y is positive and attached with a positive or negative sign)
kfr: spring constant at the right front support point kfl: spring constant at the left front support point krr: spring constant at the right rear support point krl: spring constant Lfrx at the left rear support point 11: support right front from the axis y Distance Lflx in the axis x direction to the point 10: Distance Lrrx in the axis x direction from the axis y to the left front support point 9: Distance Lrlx in the axis x direction from the axis y to the right rear support point 12: Left from the axis y Distance Lfry in the axis x direction to the subsequent support point 11: Distance Lfly in the axis y direction from the axis x to the right front support point 10: Distance Lrry in the axis y direction from the axis x to the left front support point 9: Axis x A distance Lrly in the axis y direction from the right rear support point 12 to the right rear support point 12: If the distance in the axis y direction from the axis x to the left rear support point 11 is the motion when the differential carrier 4 is elastically supported in the vertical direction The equation can be expressed as:
[0011]
[Expression 1]

[0012]
However,
m11 = m
m12 = mLGx
m13 = -mLGy
m22 = Iyy + mLGxLGx
m23 = -Ixy-mLGxLGy
m33 = Iyy + mLGyLGy
k11 = kfr + kfl + krr + kr
k12 = kflLflx + kfrLfrx−krLrlx−krrLrrx
k13 = -kflLfly + kfrLfry-krLrly + krrLrry
k22 = kflLflx Lflx + kfrLfrx Lfrx + krlLrlx Lrlx + krrLrrx Lrrx
k23 = -kflLflx Lfly + kfrLfrx Lfry + krLrlx Lrly-krrLrrx Lrry
k33 = kfl Lfly Lfly + kfr Lfry Lfry + krLrly Lrly + krLrry Lrry
And “··” represents a second-order time derivative.
[0013]
When the expression (1) is expanded, the following expression is obtained.
[Expression 2]

[0014]
Here, the time is t, the vibration frequency ω of the differential carrier 4, the displacement amplitude of the differential carrier 4 in the axis z direction is Az, the angular displacement amplitude of the rotational vibration of the differential carrier 4 about the axis y is Ay, and the axis x is the center. If the angular displacement amplitude of the rotational vibration of the differential carrier 4 is Ax, the axis z, the angular displacement θy, and the angular displacement θx are each expressed by a periodic function,
Z = Az sin ωt, θy = Ay sin ωt, θx = Ax sin ωt
Therefore, when these are substituted into the equation (2), the following equation is obtained.
[0015]
[Equation 3]

[0016]
The well-known frequency response function θx / T can be obtained by solving the following equation (3). θx / T = [ωωωω {ρ (m11m23−m12m13) + (m12m12−m11m22)} + ωω {ρ (k12m13 + k13m12−k11m23−k23m11)
+ (K11m22 + k22m11-2k12m12)} + {ρ (k11k23-k12k13)
+ (K12k12-k11k22)}] /
[(−ωωm11 + k11) {(− ωωm23 + k23) (− ωωm23 + k23)
− (− Ωωm22 + k22) (− ωωm33 + k33)}
+ (− Ωωm12 + k12) {(− ωωm12 + k12) (− ωωm33 + k33)
− (− Ωωm23 + k23) (− ωωm13 + k13)}
+ (− Ωωm13 + k13) {(− ωωm22 + k22) (− ωωm13 + k13)
− (− Ωωm12 + k12) (− ωωm23 + k23)}] (4)
[0017]
In order for θx / T = 0 to always hold regardless of the value of ω, the coefficients of the fourth-order ω and second-order ω and the constant term in equation (4) must be zero.
That is,
ρ (m11m23−m12m13) + (m12m12−m11m22) = 0 (5)
ρ (k12m13 + k13m12−k11m23−k23m11)
+ (K11m22 + k22m11-2k12m12) = 0 (6)
ρ (k11k23−k12k13) + (k12k12−k11k22) = 0 (7)
[0018]
When the above definitions are applied to the equations (5), (6), and (7), the following equations are established.
ρIxy + Iyy = 0 (8)
ρ [kfl {(Lflx−LGx) (Lfly−LGy) m + Ixy}
+ Kfr {-(Lfrx-LGx) (Lfry + LGy) m + Ixy}
+ Krl {-(Lrlx + LGx) (Lrly-LGy) m + Ixy}
+ Kr ({Lrrx + LGx) (Lrry + LGy) m + Ixy}]
+ Kfl {(Lflx-LGx) (Lflx-LGx) m + Iyy}
+ Kfr {(Lfrx-LGx) (Lfrx-LGx) m + Iyy}
+ Krl {(Lrlx + LGx) (Lrlx + LGx) m + Iyy}
+ Kr ({Lrrx + LGx) (Lrrx + LGx) m + Iyy} = 0 (9)
ρ [kflkfr (Lfrx−Lflx) (Lfry + Lfly)
+ Kflkrl (Lrlx + Lflx) (Lrly-Lfly)
-Kflkr (Lflx + Lrrx) (Lfly + Lrry)
+ Kfrkrl (Lfrx + Lrlx) (Lfry + Lrly)
+ Kfrkr (Lfrx + Lrrx) (Lfry-Lrry)
+ Krlkrr (Lrlx-Lrrx) (Lrly + Lrry)]
-{Kflkfr (Lflx-Lfrx) (Lflx-Lfrx)
+ Kflkrl (Lflx + Lrlx) (Lflx + Lrlx)
+ Kflkrr (Lflx + Lrrx) (Lflx + Lrrx)
+ Kfrkrl (Lfrx + Lrlx) (Lfrx + Lrlx)
+ Kfrkrr (Lfrx + Lrrx) (Lfrx + Lrrx)
+ Krlkrr (Lrlx-Lrrx) (Lrlx-Lrrx)} = 0 (10)
[0019]
Therefore,
Condition (A): Lflx = Lfrx = Lfx,
Lfly = Lfry = Lfy
Condition (b): kfl = kfr = kf
Condition (C): krr = 0
Is substituted into equation (10),
2kf kr (Lfx + Lrlx) {ρLrly− (Lfx + Lrlx)} = 0
Therefore, the conditions (I) to (C)
Condition (d): ρLrly = Lfx + Lrlx
If these are satisfied, Expression (10) is established.
[0020]
Also,
Condition (e): ρIxy = −Iyy
If is satisfied, equation (8) is established.
[0021]
Furthermore, conditions (A) to (E) and condition (F): Lfx = ρLGy + LGx
If these are satisfied, equation (9) is established.
[0022]
That is,
Condition (a): The elastic support points of the carrier 4 respectively disposed at two positions on the left and right of the central axis of the propeller shaft 13 on the front side of the vehicle (the propeller shaft 13 side) from the central axis of the drive shaft 14 Are made equal to each other (two elastic support points are arranged symmetrically across the central axis of the propeller shaft 13).
Condition (b): The spring constants of the elastic support points at the two left and right positions are equal.
Condition (c): The elastic support point of the carrier 4 is disposed only at one position on the left side of the central axis of the propeller shaft 13 with respect to the front of the vehicle behind the vehicle from the central axis of the drive shaft 14 (opposite the propeller shaft 13). (The elastic support point of the carrier 4 is not arranged to the right of the central axis of the propeller shaft 13).
Condition (d): ρLrly = Lfx + Lrlx
Condition (e): ρIxy = −Iyy
Condition (f): Lfx = ρLGy + LGx
(If the support mechanism of the differential 3 is formed as shown in FIG. 2), the rotational displacement of the differential carrier 4 about the axis x is always 0 regardless of the value of ω. Thus, the occurrence of the rolling resonance phenomenon in the differential carrier 4 can be surely prevented.
[0023]
In addition, in the definition of the above sign,
k12 = kflLflx + kfrLfrx−krLrlx−krrLrrx
And conditions (b) to (c)
Condition (g): 2 kf / krl = Lrlx / Lfx
Is substituted, k12 = 0, and the pitching rotation axis of the differential carrier 4 and the axis y coincide with each other. Therefore, the joint intersection of the propeller shaft 13 and the drive shaft 14 does not increase. Vibration deterioration can be prevented.
That is, in this embodiment, for example, a rubber-like elastic body having a spring constant appropriately set is disposed at each of the support points 9, 10, and 11 that are appropriately selected, and the carrier 4 moves in the vertical direction with respect to the vehicle body. It is elastically supported (supported from below or suspended from above).
[0024]
In the above embodiment, the carrier 4 is elastically supported at the two left and right sides of the central axis of the propeller shaft 13 in front of the vehicle from the central axis of the drive shaft 14, and from the central axis of the drive shaft 14 to the front of the vehicle in the rear of the vehicle. The carrier 4 is elastically supported at one place on the left side of the central axis of the propeller shaft 13, and this support mechanism is shown in FIG. The carrier 4 is elastically supported at two locations on the left and right sides of the central axis, and the carrier 4 is elastically supported at one location on the right side of the central axis of the propeller shaft 13 with respect to the front of the vehicle from the central axis of the drive shaft 14. ,
Condition (h): Lrlx = Lrrx = Lrx,
Lrly = Lrry = Lry
Condition (li): kr = krr = kr
Condition (nu): kfl = 0
Is substituted into equation (10),
2kfrkr (Lfrx + Lrx) {ρLfry- (Lfrx + Lrx)} = 0
So, conditions (Chi) ~ (nu),
Condition (Le): ρLfry = Lfrx + Lrx
If these are satisfied, Expression (10) is established.
[0025]
Also,
Condition (e): ρIxy = −Iyy
If is satisfied, equation (8) is established.
[0026]
Furthermore, conditions (e), (h) to (le) and conditions (e): Lrx = − (ρLGy + LGx)
If these are satisfied, equation (9) is established.
[0027]
That is,
Condition (h): The elastic support points of the carrier 4 respectively disposed at the two left and right sides of the central axis of the propeller shaft 13 at the vehicle rear side (opposite side of the propeller shaft 13) from the central axis of the drive shaft 14 (The two elastic support points are symmetrically arranged across the central axis of the propeller shaft 13).
Condition (I): The spring constants of the elastic support points at the two left and right positions are equal.
Condition (nu): The elastic support point of the carrier 4 is disposed only at one position on the right side of the central axis of the propeller shaft 13 with respect to the front of the vehicle from the central axis of the drive shaft 14 (propeller shaft 13 side) ( The elastic support point of the carrier 4 is not arranged on the left side of the central axis of the propeller shaft 13).
Condition (e): ρIxy = −Iyy
Condition (Le): ρLfry = Lfrx + Lrx
Condition (W): Lrx =-(ρLGy + LGx)
(If the support mechanism of the differential 3 is formed as shown in FIG. 3), the rotational displacement of the differential carrier 4 about the axis x is always 0 regardless of the value of ω. Thus, the occurrence of the rolling resonance phenomenon in the differential carrier 4 can be surely prevented.
[0028]
In addition, in the definition of the above sign,
k12 = kflLflx + kfrLfrx−krLrlx−krrLrrx
And conditions (Chi)-(nu),
Condition (W): kfr / 2kr = Lrx / Lfrx
Is substituted, k12 = 0, and the pitching rotation axis of the differential carrier 4 and the axis y coincide with each other. Therefore, the joint intersection of the propeller shaft 13 and the drive shaft 14 does not increase. Vibration deterioration can be prevented.
That is, in this embodiment, for example, a rubber-like elastic body having a spring constant set appropriately is disposed at each of the support points 10, 11, and 12 that are properly selected, and the carrier 4 moves in the vertical direction with respect to the vehicle body. It is elastically supported (supported from below or suspended from above).
[0029]
In each of the above embodiments, as illustrated in FIG. 4, the elastic support point P disposed only on one side of the propeller shaft 13 is symmetrical with respect to the support point P in the vehicle width direction. By dividing the elastic support points P1 and P2 at positions and setting the spring constants of the support points P1 and P2 to ½ of the spring constants of the support points P, the same effects as the above embodiments can be obtained. Needless to say.
[0030]
In addition, each of the above embodiments relates to a rear differential of the vehicle. However, even if these are arranged reversely in the front and rear of the vehicle and applied to the front differential, the same effects as the above embodiments can be obtained. Is something that can be done.
[0031]
【The invention's effect】
In the differential support mechanism according to the present invention, by appropriately selecting the elastic support position of the differential, the spring constant of each support point, the inertia moment of the differential, and the inertial product of the differential, the vibration of the differential is suppressed, It is possible to prevent the vibration of the vehicle body and the generation of abnormal noise.
[Brief description of the drawings]
FIG. 1 is a conceptual plan view of a differential support mechanism.
FIG. 2 is a conceptual plan view of an exemplary embodiment of the present invention.
FIG. 3 is a conceptual plan view of another embodiment of the present invention.
FIG. 4 is a conceptual plan view of another embodiment of the present invention.
[Explanation of symbols]
1 Vehicle 3 Differential 4 Carrier 9, 10, 11, 12 Support point 13 Propeller shaft 14 Drive shaft G Center of gravity O Origin

Claims (4)

The central axis of the propeller shaft that transmits the driving force to the differential and the central axis of the drive shaft that transmits the driving force from the differential to the wheel are substantially orthogonal, and the propeller shaft is closer to the propeller shaft than the central axis of the drive shaft. Two first elastic support points arranged symmetrically in the vehicle width direction across the central axis and having the same spring constant kf, and the front of the vehicle on the opposite side of the propeller shaft from the central axis of the drive shaft A differential support mechanism in which the differential is elastically supported in the vertical direction by a second elastic support point disposed only at one place on the left side of the central axis of the propeller shaft, and the following conditions are satisfied.
ρLrly = Lfx + Lrlx
ρIxy = −Iyy
Lfx = ρLG1 + LG2
2kf / krl = Lrlx / Lfx
However,
ρ: Reduction ratio Lrly of the differential Lrly: Distance from the central axis of the propeller shaft to the second elastic support point Lfx: Distance from the central axis of the drive shaft to the first elastic support point Lrlx: Center of the drive shaft The distance Iyy from the axis to the second elastic support point: the differential moment of inertia Ixy around the first axis parallel to the central axis of the drive shaft and passing through the center of gravity G of the differential: the first axis and the above The inertial product of the differential LG1 with respect to the second axis passing through the center of gravity G parallel to the center axis of the propeller shaft LG1: Distance from the center axis of the propeller shaft to the center of gravity G LG2: From the center axis of the drive shaft to the above Distance krl to the center of gravity G: Spring constant of the second elastic support point The central axis of the propeller shaft that transmits the driving force to the differential and the central axis of the drive shaft that transmits the driving force from the differential to the wheel are substantially orthogonal, and the propeller shaft is closer to the propeller shaft than the central axis of the drive shaft. Two first elastic support points arranged symmetrically in the vehicle width direction across the central axis and having the same spring constant kf, and the front of the vehicle on the opposite side of the propeller shaft from the central axis of the drive shaft The differential is elastically supported in the vertical direction by a third elastic support point arranged on the left side of the central axis of the propeller shaft, and the third elastic support point is symmetrical from the third elastic support point in the vehicle width direction. Divided into two arranged fourth elastic support points, and the spring constant of each of the fourth elastic support points is 1/2 of the spring constant of the third elastic support point, and Def support mechanism equipped with the following conditions.
ρLrly = Lfx + Lrlx
ρIxy = −Iyy
Lfx = ρLG1 + LG2
2kf / krl = Lrlx / Lfx
However,
ρ: Reduction ratio Lrly of the differential Lrly: Distance from the central axis of the propeller shaft to the second elastic support point Lfx: Distance from the central axis of the drive shaft to the first elastic support point Lrlx: Center of the drive shaft The distance Iyy from the axis to the second elastic support point: the differential moment of inertia Ixy around the first axis parallel to the central axis of the drive shaft and passing through the center of gravity G of the differential: the first axis and the above The inertial product of the differential LG1 with respect to the second axis passing through the center of gravity G parallel to the center axis of the propeller shaft LG1: Distance from the center axis of the propeller shaft to the center of gravity G LG2: From the center axis of the drive shaft to the above Distance krl to the center of gravity G: Spring constant of the third elastic support point The central axis of the propeller shaft that transmits the driving force to the differential and the central axis of the drive shaft that transmits the driving force from the differential to the wheels are substantially orthogonal, and the propeller is on the opposite side of the propeller shaft from the central axis of the drive shaft. Two fifth elastic support points which are symmetrically arranged in the vehicle width direction across the central axis of the shaft and have the same spring constant kr, and the front side of the vehicle on the propeller shaft side from the central axis of the drive shaft. A differential support mechanism in which the differential is elastically supported in the vertical direction by a sixth elastic support point disposed only at one right side of the central axis of the propeller shaft, and the following conditions are satisfied.
ρIxy = −Iyy
ρLfry = Lfrx + Lrx
Lrx = ρLG1 + LG2
kfr / 2kr = Lrx / Lfrx
However,
ρ: Reduction ratio of the differential Iyy: Inertia moment of inertia Ixy centered on the first axis parallel to the center axis of the drive shaft and passing through the center of gravity G of the differential: Center of the first axis and the propeller shaft The differential product Lfry of the differential with respect to a second axis passing through the center of gravity G in parallel with the axis: distance Lfrx from the central axis of the propeller shaft to the sixth elastic support point: from the central axis of the drive shaft to the first axis 6 Distance to the elastic support point Lrx: Distance from the central axis of the drive shaft to the fifth elastic support point LG1: Distance from the central axis of the propeller shaft to the center of gravity G LG2: From the central axis of the drive shaft to the above Distance kfr to the center of gravity G: Spring constant of the sixth elastic support point The central axis of the propeller shaft that transmits the driving force to the differential and the central axis of the drive shaft that transmits the driving force from the differential to the wheels are substantially orthogonal, and the propeller is on the opposite side of the propeller shaft from the central axis of the drive shaft. Two fifth elastic support points which are symmetrically arranged in the vehicle width direction across the central axis of the shaft and have the same spring constant kr, and the front side of the vehicle on the propeller shaft side from the central axis of the drive shaft. The differential is elastically supported in the vertical direction by a seventh elastic support point disposed on the right side of the central axis of the propeller shaft, and the seventh elastic support point is symmetrical from the seventh elastic support point in the vehicle width direction. Divided into two arranged eighth elastic support points, and the spring constant of each of the eighth elastic support points is ½ of the spring constant of each of the seventh elastic support points, and Def support mechanism equipped with conditions.
ρIxy = −Iyy
ρLfry = Lfrx + Lrx
Lrx = ρLG1 + LG2
kfr / 2kr = Lrx / Lfrx
However,
ρ: Reduction ratio of the differential Iyy: Inertia moment of inertia Ixy centered on the first axis parallel to the center axis of the drive shaft and passing through the center of gravity G of the differential: Center of the first axis and the propeller shaft The differential product Lfry of the differential with respect to the second axis passing through the center of gravity G parallel to the axis: the distance Lfrx from the central axis of the propeller shaft to the seventh elastic support point: from the central axis of the drive shaft to the second axis 7 Distance to the elastic support point Lrx: Distance from the central axis of the drive shaft to the fifth elastic support point LG1: Distance from the central axis of the propeller shaft to the center of gravity G LG2: From the central axis of the drive shaft to the above Distance kfr to the center of gravity G: Spring constant of the seventh elastic support point

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