JPS5812812A - Trailing-arm type suspension - Google Patents

Abstract

PURPOSE:To reduce the toe-out directing angle due to a lateral external force by constituting the captioned suspension apparatus for independently suspending the rear wheels for a car so that the intersecting point on the elongated lines of the high-rigidity axis lines of a trailing arm is positioned lower than the swing axis line. CONSTITUTION:The axis lines of the bushes 2 and 2' which connect a trailing arm 1 to a chassis are titled by theta1 and theta2 respectively for the swing axis line 6 of the trailing arm 1, and the high-rigidity axis lines 7 and 7 are allowed to intersect each other at the point Q on the outside of the chassis in relation to the force acting point on a wheel 5 and at the back and under the swing axis line 6 of the trailing arm 1. With such a constitution, when a lateral external force F acts onto the wheel 5, the bushes 2 and 2' deflect in the dirdctions A and B, and the wheel 5 operates around the point q, so the toe-out directing angle +Q of the wheel 5 can be reduced, and a cornering force can be improved, and the safety on traveling can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a trailing arm suspension mainly used for independently suspending the rear wheels of a passenger car.

This ridge suspension usually includes a trailing arm as shown in FIG.
Place i (regular place a) / a, i b It is supported on the car body via the elastic cylindrical pusher Jl and the car body bracket 3゜3', and the wheel S (Fig. The wheel is normally constructed by rotatably attaching the right rear wheel). Therefore, the trailing arm l is rotated in the vertical direction (perpendicular to the drawing) around the common axis iI6 together with the wheel S at the base ends ta and ib. The wheels S are elastically supported by a trailing arm L, a suspension spring inserted in the vehicle body doorway, a shock absorber, and the like.

In such a trailing arm suspension,
Wheel! Lateral external force such as when turning! ′ When Y is added, the trailing arm l along with the wheel j is mainly pushed,
Due to the elastic deformation of

However, in this conventional suspension, the low-rigidity axes in the axial direction of Pushco and CoI are the trailing arm swing axes, respectively! l≦, and the high-rigidity shaft 87 #7' in the direction perpendicular to the axis of the pushco The center of behavior of the wheel j during the above displacement is the tracing arm swing axis S
When the sill ring arm 1 and the wheel 3, which are located at the intermediate position between the ≦ and the push-LJ and -' points, receive a lateral external force FY, the wheel 3 moves in the horizontal plane as shown by the imaginary line in the figure. It behaves so that j is large and a cutting angle +θ in the toe-out direction is generated. This tendency became more and more noticeable because the center of behavior in the vertical plane was also the same, so wheel j behaved to have a large positive camber.

However, in order to derive sufficient cornering force and to improve running stability when cornering,
Lateral external force! It is preferable to configure the trailing 7-me type suspension so that the turning angle 10 of the wheel j in the door direction due to Y is made small, and preferably the wheel S makes a turning angle in the toe-in direction.

Therefore, in order to satisfy this requirement, as shown in FIG. At the same time, measures have been taken to pivot the bushing I/ to the tip of the trailing arm l at a location behind the vehicle body support shaft 10. In this case, the center of the behavior of the trailing arm l and the wheel j in the horizontal plane is changed to the position of the bush ll, and when the trailing arm l and the wheel S receive a lateral external force FY about this center, as shown in FIG. Because it behaves in the position shown by the medium imaginary line, the wheels! produces a turning angle of -0 in the toe-in direction, which satisfies the above requirements.

However, even with such a suspension, the bushing λ that causes the above behavior of the trailing arm l and the wheel j,
The axis of ko' coincides with the trailing arm swing axis t,
Since these are not in the tangential direction of the behavior arc centered on the center of the behavior (Bush// ), the axial deformation of the push rod, -', which determines the toe-in direction lifting device of the sill ring arm l and the wheel j, is sufficient. The center of behavior of the suspension in the vertical plane is also the same 1, and this is at the same level as the trailing arm swing axis 494, so the wheels! may behave in a positive camber motion, so that the wheel S does not produce a sufficient turning angle -0 in the toe-in direction, and depending on the lifting device in the positive camber direction, the above-mentioned installation effect of the assist link I is lost. This tendency shows that the bushing 9 on the vehicle body side of the conventional assist link l is #
. It is installed at a large angle as shown in
The bush 9 is easily deformed in the axial direction due to the thrust force input to the assist link 1 (the lifting device of the assist link t due to the lateral external force FY becomes larger, and the pusher 4 /
When the / position received the lateral external force FY, it escaped greatly in the same direction, making it even worse.

lE to flA, if one connecting part of the trailing arm is configured such that the high rigidity axes extending in the vertical direction of the vehicle body intersect below the trailing arm swing axis, The apparent center of rigidity is the intersection of the high rigidity axes located below the trailing arm swing axis, and the behavior of the trailing arm and wheel in the vertical plane due to lateral external force occurs around this intersection. It is believed that the above-mentioned problem can be solved if the camber change of the wheel due to behavior occurs in the direction of reducing the positive camber, and if the wheel receives a lateral external force, it does not at least cause a large steering angle in the toe-out direction. From this point of view, we aim to provide a trailing arm combined suspension engine that embodies this idea.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIGS. 3 to 6 show an at* embodiment of the present invention in which the above idea is applied to the m-type suspension shown in FIG.
In the figure, the same parts as in FIG. 7 are designated by the same reference numerals.

Although the cylindrical elastic pushbutton λ' is shown exposed in FIG. 7 for convenience, in reality these bushes 2. J' refers to the holes //, //' fixed to the proximal ends ta, ib of the trailing arm A/, and the outer peripheral surface of the sleeve 12°ν coaxially inserted into these holes. The inner circumferential surfaces of sleeves /J and /J' are fixed to the inner circumferential surfaces of sleeves /J and /J', respectively.

Then, the port inserted into Planat J and Jl/3
゜/J'ttS I) -Plλ, penetrates into 12', and connects the trailing arm l at the two-pronged base end /aj/b with a cylindrical elastic pusher, -' to the vehicle body with a common axis ≦. It is supported so that it can swing up and down.

In the example shown in the drawings, as shown in FIG. 3, a cylindrical elastic bushing 2. At least one (both in the illustrated example) of ν is connected to the trailing arm swing axis 1 with its axis in a horizontal plane.
θ0 for s≦. It is arranged so as to be inclined as shown in θ2. Then, these inclination directions and inclination angles θ0. θ2 is a high-rigidity shaft $7,7/ that exists in the direction perpendicular to the axis of each bushing 1ν (first VY direction), and the trailing arm swing axis 6
The intersection is determined to be closer to the rear of the vehicle body, preferably at a point Q rearward of the point of application of wheel j (the center point of the contact surface with the road surface) of wheel j as shown in the figure.

In addition, in this example, the highly rigid axis 7 of the pushco, 2'
．． The inclination angle of 2' is 0 so that the intersection Q of 7' is not only located at the rear of the vehicle body from the trailing arm swing axis [i14 as described above, but also located at the outer side of the vehicle body from the force application point of wheel j as shown in the figure. □ and #2 are determined respectively.

In the present invention, based on this configuration, the suspension shown in FIG. 3 is shown as shown in FIG.
, //' are not only tilted with respect to the trailing arm swing axis @1 in the horizontal plane as described above, but also in the vertical plane.
The trailing arm is tilted with respect to the swing axis 6 as shown by θ4. Then, by selecting the angle of inclination and the direction of inclination, for example, as shown in the figure, the highly rigid axes #, /#' in the direction perpendicular to the axis of the push coco' in the vertical direction of the vehicle body are positioned below the trailing arm swing axis ≦. For example, they intersect at point R. In addition, this intersection R is a wheel as shown in the diagram! It is best to position it below the point of force.

In the suspension of the present invention having such a configuration, the center of rigidity of the bushes λ and I in the direction of the single machine is a point Q, and when the wheel S receives a lateral external force FY, the bushes J, 2
As a result, the trailing arm l and the wheel j become curves that move around the point Q. By the way, in the above configuration, since the point Q is located at the rear of the vehicle body than the trailing arm swing axis lid, the turning angle 10 in the toe-out direction of the wheel j due to the external force FY in the machine direction (see Fig. 1) can be made smaller accordingly. Cornering force can be extracted effectively, and driving stability can be improved during cornering and high-speed driving.

Note that if the intersection point Q is located at the rear of the vehicle body than the force application point of the wheel 50 as shown in the illustrated example, the trailing arm I and the wheel j will behave in a twisting manner when receiving the lateral external force FY, and the cornering force will be reduced. In addition to being able to draw out the torque more fully, it is possible to further improve running stability during cornering and when running at both speeds. Father, if point Q is located on the outside of the vehicle body from the force application point of wheel j as shown in the example, regardless of whether this intersection point is located in front of the vehicle body or behind the force application point of wheel j. By locating the intersection point behind the trailing arm swing axis t of the vehicle body, the above-mentioned effects can be made more pronounced, which is advantageous. In other words, the intersection point Q is located outside the vehicle body from the point of application of the force of the wheel j. In this case, the braking force FX shown in FIG. 3 acting on wheel j at the point of application of force during braking causes the wheel S to behave in the toe-in direction around the intersection Q.

Therefore, the tendency of the vehicle body to oversteer when braking is applied during turning can be prevented, and safety can be improved.

In the present invention, the high-rigidity shaft #jl/41°/ri' that is perpendicular to the axis of the bushing λ 21 extending in the vertical direction of the vehicle body intersects at the point R below the trailing arm swing axis fiiit. Wheel j receives lateral external force li
'Y, this wheel and the trailing arm 1 behave in a vertical plane around the intersection point R, and as a result, the tendency of the wheel 5 to become positive □ or shivering can be reduced. Father, turn the intersection R into a wheel j as shown.
If you position it in the F direction from the point of force, it's a wheel! is caused to behave in a negative camber due to the lateral external force Fy as shown by α in tv4, and as the canvas lath F increases, when the wheel j receives the lateral external force Fy, it breaks in the toe-in direction as described above. The effect of correcting the corner and increasing the cornering force can be more pronounced.

In addition, in this example, as in the present invention, there is a configuration in which the pusher I is inclined with respect to the trailing arm swing axis M4 in a vertical plane, and a configuration in which the pusher I is tilted in a horizontal plane with respect to the trailing arm swing axis M4. Although the suspension of the present invention does not adopt the latter structure, it is possible to reduce the tendency of the wheel j to behave in the positive camber direction due to the lateral external force lFY, As a result, the wheel j can be prevented from producing a large turning angle in the toe-out direction, and sufficient cornering force can be extracted, and driving stability can be improved during cornering and high-speed driving. be able to.

7 and 7 show another configuration example in which the idea of the present invention is applied to the type of suspension shown in FIG. Instead, the vehicle body bracket 3.31 has the following special configuration.

That is, the legs of the vehicle body platen (j, J') are configured to be elastically deformable in the lateral direction of the vehicle body, and the legs (y, r) in FIG.
, as shown by I, in the horizontal plane, and the high rigidity axes /j, / of both plastic nuts 3, 3' in the longitudinal direction of the vehicle body.
J' is hoisted in the longitudinal direction of the vehicle body so as to form an angle other than right angles to the trailing arm swing axis 6. Then, by varying the above angle far', the high rigidity shaft @/S, /3'
intersect at a point P rearward of the vehicle body from the trailing arm swing axis t, preferably rearward of the force application point of the wheel 3.

Father, it is better to bring this intersection point P to the outside of the vehicle body than the point of force applied to wheel j.

In the present invention, such a bracket 3°s'W
The 1 part of the ui is tilted in the vertical plane as shown by β'' and βI in the figure with respect to the line perpendicular to the trailing arm swing axis 6, and the height of both brackets 3 and 3' is increased in the vertical direction of the vehicle body. Rigidity axis/6. /6' and the intersection S is located below the trailing arm swing axis 1fM6. Note that this intersection S is preferably located further below the force application point of the wheel j as shown.

In the suspension of the present invention having such a configuration, the center of rigidity in the horizontal plane is at the vehicle body bracket node 3.3.
When the high-rigidity axes /s and /3' of I are at the intersection P, and the wheel j receives a lateral external force 1i'Y, the trailing arm l
The wheel j moves around this intersection P in the horizontal plane, but the intersection P is the trailing arm swing axis ≦
Because it is located further back in the vehicle body, the external force Fy in the polarization direction is applied to the wheels! Turning angle in the toe-out direction of 100 (see Figure 1)
can be made small, cornering force can be extracted effectively, and driving stability can be improved during cornering and high-speed driving.

In addition, as shown in the illustrated example, the intersection P is a wheel! Trailing arm l and wheel j
As shown by the imaginary line in Fig. 7, the steering angle in the toe-in direction is reduced by -0 or at least 100 by the outward FY in the lateral direction, and the cornering force can be sufficiently exerted, and it is possible to The running stability during running can be further improved. In addition, if the intersection point P is located outside the vehicle body from the point of force application of wheel j as shown in the illustrated example, regardless of whether this intersection point is located in front of the vehicle body or behind the point of force application of wheel j. Trailing arm swing axis IIi at the intersection point! ≦The above-mentioned effects due to being located at the rear of the vehicle body can be further optimized. That is, when the vehicle is braked, the braking force applied to wheel j can generate a moment that reduces the turning angle in the toe-out direction of wheel 3, and if the braking force is large, it is possible to even give a turning angle in the toe-in direction of wheel j. can.

In the present invention, the center of rigidity in the vertical plane of the suspension is the intersection S of the high rigidity axes l≦76' of the vehicle body platen J and J', and when the vehicle J receives a lateral external force FY, the trailing The arm l and the wheel S move around this intersection S in the vertical plane. Since this intersection S is located below the trailing arm swing axis i≦, the wheel j is affected by the lateral external force FY. This can reduce the tendency for positive camber. In addition,
If the intersection point S is located below the force application point of the wheel j as in the illustrated example, then the wheel! It is even possible for the lateral force FY to result in a negative camber, as indicated by α in FIG. For these reasons, the suspension of the present invention can more favorably produce the effect that the turning angle of the wheel j is corrected in the toe-in direction as described above. Note that even if the brackets J and J' are not configured like M7iW so that the turning angle of the wheel 5 is corrected in the toe-in direction, in the present invention, the brackets 3 and 3 are configured as shown in the figure. When the high-rigidity axes /l and /4' in the current plane of ' intersect below the trailing arm swing axis 4, the wheel j tends to become a tapered camber due to the lateral outward FY as described above. The trailing arm l can be made to behave so that the wheel j becomes a negative camber due to the lateral external force Fy, and the canvas last increases.
It is possible to draw out a larger cornering force and achieve the objective of improving running stability.

Figures 9 to 1/1 are eye holes/1. , /l', therefore, the bushings in these holes are made to coincide with the swing axis @4 of the trailing arm l as in the past, and the bracket 3°3' is also configured in the same manner as in the past, so that the trailing arm l
is connected to the vehicle body, but the base end of the trailing arm l is configured in the following special configuration to achieve the desired purpose i.
An example of a pond according to the present invention is shown below.

In this example, a U-shaped plate spring 17 as shown in Figure 1 is prepared, and its legs /7a and /7b are connected to the 9th
As shown in the figure and Fig. 10, the single unit is arranged in a uniform manner in one direction and is attached to the base of the vehicle body side of the trailing arm L using bolts /1, and attached to the vehicle body side of the trailing arm L using the leaf spring legs /7a and /7b. Configures the base end of the attachment. For this purpose, holes //, //' are fixedly installed at the free ends of the leaf spring legs /7a, /7k, respectively, and the bushes in these holes (pushcos in Figures q and 3) are fixed. The trailing arm I is attached to the shaft S via the bracket 3.3'
It is connected to the vehicle body l so that it can swing vertically around the head.

The leaf spring legs /7a and /7b are the trailing arm swing axis I! It is inclined as shown in FIG. 9 in a horizontal plane with respect to a line perpendicular to i16, and the plate d leg part /7 in the longitudinal direction of the vehicle body. L, /7. High rigidity axis of b/9. .

191 at the rear of the vehicle body from the trailing arm swing axis #i14, preferably at a point O rearward and outside the force application point of the wheel j.

In the present invention, both leaf spring legs/7a, 17
11 in the vertical plane as shown by g and tl in FIG.
il#I, and intersect the high rigidity axes @x and x' of both legs 775L and /7b that extend in the vertical direction of the vehicle body, and place their intersection T below the trailing arm swing axis IJ4, preferably near the wheel. Position it below the point of force on j.

□ Even in the structure of this example, the center of rigidity of the suspension is the high rigidity axis @tq in the horizontal plane.

/9' is the intersection O, and in the vertical plane, the high rigidity axis 1
The intersection point T between ix and XJ' is the same as in the previous example, so wheel j
Will the cutting angle in the toe-out direction be reduced when receiving
It behaves so as to produce a turning angle in the toe-in direction, and the desired purpose can be achieved in the same manner as in the above-mentioned example.

In addition, in the present invention, the leaf spring leg part /7a, t7
Even if b is not tilted in the horizontal plane as shown in Figure 9,
By bringing the intersection point T of the high-rigidity axes @X) and The trailing arm l can be made to behave by lateral external force so as to reduce the camber or create negative camber, and as the canvas thrust increases, it is possible to extract a larger cornering force, which improves running stability when cornering and high speed running. The desired goal of sexual improvement can be achieved.

In each of the above-mentioned embodiments, the idea of the present invention was applied to the type of suspension shown in Fig. 1, but each of these configurations can also be applied as is to a trailing arm type suspension having an assist link l as shown in Fig. 1. A typical example in which the configuration shown in Figures 3 to 3 is applied to this suspension with assist link is shown in Figure 1.
This is shown in Figures 2 to 1. However, in this example, as mentioned above, the center of rigidity of the suspension in the horizontal plane is located at the bushing// at the rear of the vehicle body from the trailing arm swing axis IIJ4, so the center of rigidity of the suspension in the horizontal plane is Highly rigid shaft @7 located in the longitudinal direction of the vehicle body,
The bushing mounting angles 0□ and 02 are determined so that the bushings 7' intersect at a point Q rearward of the vehicle body from the bushings l/.

In addition, the high rigidity shafts @n, ty' of the push rods and wheels located in the vertical direction of the vehicle body are as shown in FIG. 3 to 4.
As in the example in the figure, the trailing arm swing axis ≦ a point below the vehicle body, preferably the wheels! Intersect at a point R below the force application point, and determine the mounting angle of the pushcoat, ν, to be 03°0 so that this purpose can be achieved.

In this example, wheels! When subjected to lateral outward FY, the trailing arm l will behave in a horizontal plane centered at a point Q behind the vehicle body than the bushing /l,
Pushco in the tangential direction of the arc centered on this point Q, -
' is directed, and the amount of deformation due to the lateral external force FY increases, so the trailing arm l behaves so that the wheel j produces a turning angle -θ in the toe-in direction that is larger than before, and a sufficient amount of cornering force is exerted. To ensure improved running stability during cornering and high speed running. □ In this example, the mounting angle θ' of one pusher is the conventional mounting angle θ. (Refer to Figure 1) If it is made larger, when the thrust force due to the external force FY is applied to the assist link j, the amount of axial deformation of the bush 9 will be reduced and the bush /
The position change (escape) of / can be reduced, and the assist link t
The above-mentioned effect due to the provision of wheels, that is, wheels! The effect of causing the trailing arm l to behave so as to produce a turning angle in the toe-in direction can be made even more remarkable, and the effects of this example can be achieved even more rapidly.

Furthermore, if the intersection point Q is located on the outside of the vehicle body from the force application point of the wheel j as shown in Fig. 72, the braking force r applied to the wheel j during braking is
This causes the wheel j to behave in the toe-in direction around the point Q, and when braking is performed during turning, the wheel j will further increase the turning angle in the toe-in direction, making it even more effective.

In the present invention, the bushing 2.21 is inclined #i even in the vertical plane with respect to the trailing arm swing axis Iv≦, and the bushing 2.21 is made to have a high rigidity shaft @/da, /# which is located in the vertical direction of the vehicle body of the bushing λl. ' are configured to intersect below the vehicle body from the trailing arm swing axis 6, so that the trailing arm l and the wheel j
will behave due to the lateral external force FY, and the tendency of the wheel j to become positive camber can be reduced.

If the intersection point R is located further below the force application point of the wheel j as shown in Fig. 73, the wheel j will behave in a negative camber due to the lateral external force FY as shown by α, and the wheel j will move in the lateral direction. As the canvas last increases when external force FY is applied, the above effects can be made more reliable.

In addition, as in this example, Bush 2. Even if the configuration in which λI is tilted in the horizontal plane as shown in FIG. 12 is omitted, in the present invention, the push lever 2' is tilted in the vertical plane as shown in FIG. It is possible to reduce the tendency of positive camber due to FY, or to cause the trailing arm l to behave so as to cause negative camber due to the lateral external force FY, so that wheel j rises to the presence of assist link l and is steered in the toe-in direction. The angular effect can be further increased, and the object of the present invention can be achieved.

In this example, especially, the intersection points Q and R are made to coincide,
The surface containing this point and the center point of Pushko, λ' is Bush 2. When wheel j is subjected to a lateral external force Fy, the trailing arm l has its supporting rigidity Since the direction coincides with the direction of the lateral external force FY, there is no roll, and camber change due to the lateral external force FY of the wheel j can be eliminated. In this case, since the wheel j receives the lateral external force FY and the camber is not changed, the desired purpose can be achieved while maintaining the effect of providing the assist link t.

Trailing arm type suspension E of the present invention!
＞ is the proximal end connecting portion of the trailing arm l (in the examples shown in FIGS. In the example shown in Figs. 9 to 11, the base end of the trailing arm L when attached to the vehicle body /75L, /
7b), high-rigidity axes I and I (see FIGS. 6 and 73) extending in the vertical direction of the vehicle body, 16.
16' (see Figure J) and ff#ffl' (see Figure 1θ) are configured and arranged so that they intersect below the trailing arm swing axis 6, so that the wheel j is affected by the lateral external force FY.
The trailing arm l can be made to behave so as to reduce the tendency to be in positive camber or to be in negative camber when the wheel is hit, and prevent the wheel j from being steered too far in the toe-out direction. This makes it possible to steer the wheels in the toe-in direction, thereby making it possible to sufficiently extract cornering force and improve driving stability during cornering and high-speed driving.

[Brief explanation of the drawing]

7 and 1 are plane views showing two examples of the conventional trailing arm type suspension, respectively; sJ [lu is a plan view showing the trailing arm type suspension of the present invention; The figure is a cross-sectional view showing the cylindrical elastic bush attachment part, Figure 5 is a perspective view of the attachment part, Figure 6 is a front view of the suspension shown in Figure 3 as seen from the front of the vehicle body, and Figure 7 is the front view of the suspension shown in Figure 3. FIG. 9 is a plan view similar to FIG. 3 showing an example of a pond according to the invention; FIG. 9 is a front view similar to FIG. A plan view, FIG. 10 is a front view similar to FIG. 6, FIG. 1/(2) is a perspective view of the U-shaped plate spring used in the same embodiment, and FIG. 12 is a front view similar to FIG. 3 shows an example, FIG. 13 is a front view similar to FIG. 4, and FIG. 11 is a side view of the same embodiment as seen from the left side of No. 1j tltJ. ... Trailing arm, /&, /b ... Vehicle body connection base end, J, Co. I ... Cylindrical elastic bushing, J, J'.
...Car body bracket, l...Car body! ...wheel, 6
... Trailing arm swinging wheel line, l... Assist link, ? , //...assist link bush, 11
．． //'...eye hole, /2,12'...sleeve,/
J, /J'...volt, /41゜n', it, tν,
J, J17'... High rigidity axis, /7 - U-shaped leaf spring, /7a, /7b... Leaf spring leg, /I... Bolt, U... Wheel force application point. Figure 1 Figure 3 Figure 6 Figure 11 Figure 13 Figure 14j1

Claims (1)

[Scope of Claims] L includes a trailing arm, the base end of which is connected to the vehicle body at least at a point λ so as to be swingable in the vertical direction via a cylindrical elastic bushing and a vehicle body bracket, and the day wheel is rotatable first. The base end connecting portion of the trailing arm is connected to the trailing arm Type 5 suspension installed on the vehicle so that the high rigidity axes extending in the vertical direction of the vehicle body intersect below the trailing arm swing axis. The trailing arm 8 type suspension is patented as follows: A trailing arm type suspension for a machine according to Item 11!1, wherein the rigidity 11II41 intersects below the trailing arm swing axis. & The trailer-long arm type suspension according to claim 1, wherein the vehicle body bracket is configured such that each high-rigidity axis is threaded in the vertical direction of the vehicle body and intersects below the trailing arm swing axis. Claim 1: The base end of the trailing arm for attaching to the vehicle body is constructed of a leaf spring, and each high-rigidity axis extends in the vertical direction of the vehicle body and intersects below the trailing arm swing axis. Trailing arm suspension as described in section.