JPS6144012A - Vehicle front wheel suspension system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention provides a structure for eliminating unbalanced rotational moment relative to the left and right king pin shafts caused by a difference in bending angles between the left and right drive shafts in a vehicle having drive shafts of unequal length. Regarding.

[Technical background of the invention and its problems]

BACKGROUND ART Conventionally, in an automobile, which is a type of vehicle in which an engine 1 is disposed horizontally at the front of the chassis to drive the front wheels as shown in FIGS. 7 and 8, the position of the differential gear 2 is shifted from the chassis center. Therefore, the lengths of the respective drive shafts 7.8 from the output shaft 3.4 of the differential gear 2 to the left and right wheels 5, 6 are different from each other. Naturally, left and right drive shafts 2.8 and wheels 5.
The bending angles θL and θR, which are the angles formed by the central axis of 6, are also different on the left and right sides.

As a result, the wheel 5 generated by the drive torque during acceleration
, 6 inwardly swinging inward about the king pins 9, 10, respectively, resulting in a difference in the moments ML and MR. Since this rotational moment increases as the bending angle of the drive shaft increases, there is an inconvenience that the ML (or MB, which is on the side of the longer drive shaft 5) and the steering wheel tend to be removed.

In order to eliminate this phenomenon of the handle being taken off, the bending angle of each drive shaft 5.6 was made as small as possible to reduce the difference between the drive shaft bending angles θL and θR, and the length difference between the drive shafts 5.6 was made as small as possible. Attempts are being made to make it as small as possible.

However, due to restrictions on wheel diameter, ground clearance, tread, etc., there are limits to the design of the length and bending angle of the drive shaft, and the smaller the vehicle, the more difficult the design.

Therefore, as seen in Japanese Patent Publication No. 52-48380, for example, the amount of center offset between the left and right wheels (the distance between the king pin axis and the wheel center line on the axle line of the wheel as seen from the longitudinal direction of the vehicle body.
Say TCR. ) by creating a difference between the left and right king pins 9, 10, the unbalanced rotational moment ML < MR with respect to the axis is generated and balanced, and an invention has been devised that prevents the steering wheel from being taken off during acceleration. It was done.

Specifically, the knuckle of the long drive shaft side wheel and the one to 07F-? -The inclination angle of the kingpin axis was reduced by shifting the position of the inward part of the rug inward, and the inclination angle of the left and right kingpin axes was the same, and the kingpin axis on the long drive shaft side was moved parallel to the open side of the car body. The inclination angle and position of the king pin shaft can be changed, and by shifting the mounting position of the wheel to the outside of the vehicle body, the amount of center offset can be changed.

However, in this type of structure, the suspension system configuration is left-right asymmetrical parts (Ni-・・・).

knuckle), and non-common parts for the left and right sides (constant velocity joint), which has a negative impact on cost.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a front wheel suspension system for a vehicle that has the same center offset amount on the left and right sides and can reliably eliminate unbalanced rotational moment with respect to the left and right kingpin shafts. This is what we are trying to provide.

[Summary of the invention]

That is, the present invention prevents bending of the left and right drive shafts by making a difference in the amount of kingpin offset, which is the distance between the perpendicular line passing through the center of the front wheel contact surface and the extension of the kingpin axis, on the front wheel contact surface. This is intended to eliminate the unbalanced (rotational) moment with respect to the left and right kingpin shafts caused by the difference in angle.

[Embodiments of the invention]

An embodiment of the present invention will be described below based on the drawings. Reference numeral 11 shown in FIGS. 1 and 2 is a differential gear, and output shafts 12 and 13 protruding from both left and right sides of the differential gear 11 are connected to drive shafts 7) and 76 via constant velocity joints 14 and 15, respectively. .17
is connected. A constant velocity shaft 18, 19 is provided at the end of each drive shaft 16, 17, to which a king pin shaft 27, 28 and a spindle of a front wheel 22, 23 are connected to form a suspension system.

The differential gear 11 is located at a position offset from the center of the chassis, and the drive shafts 16 and 17 have different lengths. The axle line 24 of the wheels 22 and 23 corresponds to the left and right wheels 2.
2.23 are both at the same ground clearance R, so the bending angles θVL rθVR of the drive shaft 16°17 are different on the left and right sides.

From this, there will be a difference in the rotational moment generated on the king pin shaft 27.28''!
．． 26 and the extension line of the king pin shaft 27.28 8L
+ (This can be resolved by making a difference in the amount of kingpin offset, which is 3B.

That is, the rotation moment generated by the king pin shafts 2y and zsi consists of the following two components.

■ Moment generated by the secondary couple of the above constant velocity joint 18.19 (Mt, , Mn) ■ Moment generated by the king pin offset (m, , * n
1g) Therefore, the resultant force of the rotational moment generated around the kingpin shaft 27.28 is ML, MR, and Ml - ML.
If = 0, no left-right unbalanced rotational moment will occur, and if #1 is close to O, it will be difficult to generate.

The reason why a secondary moment occurs in the above-mentioned constant velocity join) 78.19 can be explained from FIGS. 3 to 6. As shown in Fig. 3, approximately 9 joints when a joint with an intersecting angle transmits torque will be considered in terms of a simplified diagonal. If the force transmission points are P point and Q point, and the force is F, then
F=-.

r Next, as shown in FIG. 4, consider the approximately 9 match between the force and torque (moment) acting on the element (2) on the output side of the joint. Torque T matches 2 x Fr by about 9, but
Approximately 9 total couples Ml remain, which are generated in the rotation of the axis R8 perpendicular to the axis of the element (2) through the center point 0 of the cylinder.

θ M1=2XFXrtm- θ 2 T-1 Similarly, for element I, the couple θ perpendicular to the axis of ■ Msummer=Ttan-H occurs.

That is, as shown in Fig. 5, the left and right constant velocity joint &I e a! The second-order moment acting on the OLO blade ML = T m * MR = T - T and Nashi, and the moment on the left and right king pin shafts is as follows.

At this time, if the left and right joint intersection angles are θL<θR, then 6M = Mn - ML > 0 In the figure, it is easy to get the handle on the left side.

As shown in Figure 6, the actual joint intersection angle θ is θ=
Since it is determined by cxB-' (Q!I07/fish θh), it consists of the longitudinal angle θh and the vertical angle θ7. Of the 2θ-order moment M=Ttan-y, the component that is effective in eliminating the unbalanced moment is as follows. Therefore, the equation representing the moment of rotation of the left and right kingpin shafts is expressed as follows. From this, it can be seen that if the vertical angle θV is zero, the unbalanced rotational moment will be zero even if the intersection angle θ is not zero.

Applying the above results to Fig. 1 above, the moment generated by the secondary couple of constant velocity joints 1B and 19 is (θV drive shaft rear bending angle, θ drive shaft actual bending angle) Kingpin Therefore, the moment generated by the offset is the resultant force of the moment generated by the king pin shaft 27.28 times.The resultant force of the moment generated by the offset is a negative offset (the point where the ground point of the king pin shaft is outside the vehicle body as well as the point of ground contact of the tire).

(opposite: positive offset)) ML=ML-mL M, = MR-m2 Therefore, the difference between the left and right moments is It is expressed by the formula.

If Mn - ML = 0, unbalanced rotational moment will not occur, and it will be difficult to generate it even if it is small. In today's cars, the amount of king pin offset must always be equal on both the left and right sides. however,
As is clear from the above equation A, by making a difference between the left and right king pin offset amounts el l eB, the rotation moment relative to the king pin shaft 27° 28 can be balanced between the left and right sides. Actually, since the difference between the kingpin offset amount eL and eR only needs to be 2 to 3 m/m, the inclination angle β27. Only a very small change in β28 is required. (β2γ<β28).

However, at this time, the center offset amount is the same on the left and right sides.

〔Effect of the invention〕

As explained above, according to the present invention, the rotational moments relative to the left and right kingpin shafts can be balanced on the left and right sides relatively easily without significantly modifying the suspension system components, and there is no adverse effect on costs.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of a front wheel seen from the rear side of a front wheel drive vehicle showing an embodiment of the present invention, FIG. 2 is a schematic plan view of the front wheel, and FIGS. 3 to 6 are Fig. 7 is a plan view of the front wheel of a typical front wheel drive vehicle, and Fig. 8 is a front view thereof. 16.17... Drive shaft, θVLrθvn・
...Bending angle, 27.28...King pin shaft, eLIe
R...King offset amount. Applicant's agent Patent attorney Takeshi Suzue Production Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a front-wheel drive vehicle with drive shafts of unequal length, the unbalanced rotational moment for the left and right king pin shafts caused by the difference in the bending angle of the left and right drive shafts can be canceled by providing a difference in the offset amount of the left and right king pins. The front wheel suspension system of the vehicle is a feature.