JPS59213508A - Suspension arm - Google Patents

Abstract

PURPOSE:To reduce the stress concentration of a reinforced arm section and improve durability by specifying the car upward and downward direction bending rigidity and thickness of the reinforced arm section that is extended from the main unit section of the arm and is supported on a car body so as to freely swing. CONSTITUTION:A suspension arm, for example, a transverse link is comprised with an arm main unit section whose one end is connected to a wheel and whose other end is supported on a car body so as to freely swing and a reinforced arm section 2 that is extended from the arm main unit section and is supported on the car body so as to freely swing. In this case, the base end of the reinforced arm section 2 uses a reinforced member 4 with a cylindrical cross section and the tip section uses a flat reinforced extension material 15. In addition, the tip section uses only a plate 3 without reinforcement and the thickness is reduced toward the outside in the car width direction in multiple steps. Furthermore, an outside bending section 3a is formed on both ends of the plate 3. As a result, the static bending rigidity relationship is established so that the car upward and downward bending rigidity can be lower than the car right and left direction bending rigidity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension arm of an automobile, and particularly to a technology for reinforcing a suspension arm.

(Prior art) Conventionally, as a transverse link (an example of a suspension arm) used in a strut type front suspension, the ones shown in Figs. 1 to 6 are known (Mitsusan Pulsar Maintenance, published in 1982) Instructions page 106).

To explain its configuration, the conventional transverse link T
' is an arm body part 1' whose one end is connected to the wheel and the other end is swingably supported by the vehicle body, and a reinforcing arm part which extends from the arm body part 1' and is swingably supported by the vehicle body. 2/
The arm body part 11 is formed by welding two press-formed plates 3/, 3/ top and bottom together, and the reinforcing arm part 2' extends from the arm body part 1'. It was formed by two plates 3/, 3' and a reinforcing member 4/ which was clamped and connected between the plates 3/, 37.

However, such conventional transverse link TI
In this case, the reinforcing member 4' of the reinforcing arm part 2' was a hot forged product processed by plastic deformation at a temperature higher than the recrystallization temperature of the metal material. The thickness of the reinforcing member 4/ was at least about 6 tha.

Therefore, as shown in FIG.
3/ only, the wall thickness was small, and the boundary part S/ between the reinforcing arm part 2' and the arm main body part II had a sudden cross-sectional change, which caused significant stress concentration on the metal part where external force was applied. Met.

Due to this stress concentration, even if statically the external force does not reach the level of excessive input that would lead to breakage, the fatigue phenomenon due to the reversing load progresses, resulting in a problem of poor durability.

Furthermore, due to this stress concentration, excessive input is applied to the transverse link T', even if the bending rigidity of the reinforcing arm part 2' is lower than the bending rigidity of the vehicle in the horizontal direction, which is the bending rigidity in the vertical direction of the vehicle under a static load. Even if the boundary part S′
Since the damage caused by the stress is dominated by the influence of stress concentration,
The direction of damage is not necessarily limited to the vertical direction of the vehicle, but in the case of W2, where stress concentration suddenly exceeds the limit of the vehicle's lateral bending rigidity, a situation may occur where the arm portion 21 bends toward the vehicle body and is damaged. However, there were problems in that wheel alignment such as toe-in angle and camber angle changed, and even the vehicle body was damaged.

In addition, since the conventional reinforcing member 4' was a hot forged product, it required a complicated hot forging die, and furthermore, the connecting end 4I/, which connects and supports the vehicle body, was machined due to poor accuracy. It was necessary to apply

(Object of the Invention) The present invention has been made to solve the above-mentioned problems, and its purpose is to alleviate stress concentration against external forces applied to the reinforcing arm portion of the suspension arm. It is an object of the present invention to provide a suspension arm that can enhance the reinforcing effect and increase durability by forming a reinforcing arm portion on the top of the suspension arm, and can also ensure consistency in the direction of damage caused by excessive input.

(Structure of the Invention) An arm body whose one end is connected to a wheel and whose other end is swingably supported by the vehicle body; and a reinforcing arm which extends from the arm body and is swingably supported by the vehicle body. In the suspension arm, the reinforcing arm portion is formed so that the bending rigidity in the vertical direction of the vehicle is lower than the bending rigidity in the horizontal direction of the vehicle, and the thickness of the reinforcing arm portion is turned outward in the width direction of the vehicle. This is a configuration in which the amount is reduced in multiple stages.

(Effects of the Invention) Therefore, in the suspension arm of the present invention, since the wall thickness of the reinforcing arm is reduced in multiple steps at the same time outward in the vehicle width direction, As a result, stress concentration is alleviated, and the progress of fatigue caused by repeated loads can be significantly delayed, and the durability of the suspension arm can be improved due to the high sagging effect.

In addition to the above-mentioned stress concentration relaxation, the bending rigidity of the reinforcing arm part is the same in the vertical direction of the vehicle, and the bending rigidity in the left and right direction of the vehicle is 1i.
Since it is formed so that the stiffness is lower than the stiffness, even if an excessive input is applied to the reinforcing arm ml≦, it is hardly affected by stress concentration and the static stiffness resistance described above is maintained. This has the effect of maintaining consistency in that the direction of damage is only in the vertical direction of the vehicle.

(Example) In describing an example, a transverse link (an example of a suspension arm) used in a front suspension of a front engine front drive vehicle will be described below as an example.

First, FIG. 4 is a diagram showing a strut type front suspension, where T is a transverse link according to an embodiment of the present invention, 5 is a mount insulae, 6 is a coil suspension,
ring, 7 is strut, 8 is steering knuckle,
9 is a wheel hub, 10 is a drive shaft, 11 is a ball joint for connecting one end of the transverse link T and the wheel side member, and 12 is a transformer for supporting the other end of the transverse link T to the two military bodies. Birthlink Gazette.

Next, the actual transverse link T shown in FIG. The reinforcing arm part 2 is provided and is swingably supported by the vehicle body.

The arm main body 1 is formed in the vehicle width direction by welding two press-formed presses 3, 3 vertically together,
A connecting hole 13 is formed at one end to connect with the wheel side member, and a connecting short cable 14 is formed at the other end to connect and support the transverse link gusset 12, which is formed on the side of the vehicle body, via a vibration-proof bushing. is fixed.

Further, the reinforcing arm section 2 includes two plates 3, 3 extending from the arm main body section 1, and these plates 3, 3.
The reinforcing member 4 and the reinforcing extension i1'41 are sandwiched and connected in between.
5, and a connecting end 4a for connecting and supporting the transverse link gusset 12 via a vibration-proof bushing is integrally molded at the end on the vehicle body side.

The reinforcing part 4 is formed by cold-keying, followed by rough bending and pressing for 11', and one part of the reinforcing part 4 has a thickness of about 4 mrrt. A reinforcing extension member 15 with a similar plate height is integrated by welding or the like.

Next, the cross-sectional structure of the reinforcing arm part 2 will be explained with reference to FIGS. 6 to 10. As shown in FIG. Supplement a) As shown in Fig. 8, the middle part is a reinforcing member 4 with a flat cross section of about 8 mrn in thickness, and the selling price Tff: 1 is as shown in Fig. MYQ. ,
Flat cross section with constant width 0] Reinforcement sound 1 4 and reinforcement extension 15
is added, and the leading edge has a thickness of approximately 4 mm as shown in Figure 10.
It is assumed that the reinforcement is extended to the size of a plate. In other words, the reinforcing arm part 20, the part by the tension member 4, the part by the reinforcing extension member 15G, the simple plate 3 without reinforcement,
The wall thickness is reduced in two stages: the part with only 3.

Further, the reinforcing arm portion 2 is shown in FIGS. 8 to 10.
As shown, outwardly bent portions 3 are provided at both ends of the plates 3, 3.
a.

3a, and the static bending rigidity relationship is such that the bending machinability in the vertical direction of the vehicle is lower than the bending rigidity in the left and right direction of the vehicle.

Therefore, in the transverse link T of the embodiment, the boundary portion S between the reinforcing arm portion 2 and the arm body portion 1 is the reinforcing extension member 1.
Since the cross section changes stepwise due to the intervention of 5, the stress concentration is alleviated only by the smallest stress concentration caused by the external force occurring stepwise.

This stress concentration and integration increases the fatigue strength against repeated external forces applied from wheels and the like, and improves the durability of the V6 strong arm section 2 against fluctuating loads that do not reach the point of failure.

Furthermore, when an excessively large sword that causes damage is applied to the reinforcing arm part 2, due to stress concentration relaxation, the influence of stress concentration is low, and the damage state is dominated by static bending opening relationship, and the direction of damage is the top and bottom of the vehicle. direction. ), it is possible to ensure the consistency that damage occurs only when the

In addition, in the actual example, since the reinforcing part 4 is manufactured by cold-forming, it can be formed by inexpensive processing, and there is no problem with the wall thickness. It is not subject to any restrictions.

Furthermore, since the cold forged 6o product has high precision, there is no need to machine the connecting end 4a of the reinforcing member 4.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment. It is only necessary to reduce the thickness in multiple steps, and the material may be an integrally molded product made of lightweight, high-strength material such as aluminum alloy. If so, it is not limited to the embodiment.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a conventional transverse link, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, and Fig. 3 is a cross-sectional view taken along the line A-A in Fig. 1.
4 is a perspective view showing a strut type front suspension using a transverse link according to an embodiment of the present invention; FIG. 5 is a plan view showing a transverse link according to an embodiment of the present invention; Fig. 6 is a plan view showing the main part of Fig. 5, Fig. 7 is a sectional view taken along the line C-C in Fig. 6, Fig. 8 is a sectional view taken along the line D-D in Fig. 6, and Fig. 9. 10 is a cross-sectional view taken along the line E-E, and FIG. 10 is a cross-sectional view taken along the line F-F. T... Transverse link (an example of a suspension arm), 1... Arm main body part, 2... Reinforcement arm part, 3... Plate, 4... Reinforcement member, 15... Reinforcement extension member. Patent applicant Nissan Motor Co., Ltd. Figure 2 Figure 3

Claims (1)

[Claims] (1) It has an arm body part whose one end is connected to the wheel and whose other end is swingably supported by the vehicle body, and a reinforcing arm part which extends from the arm body part and is swingably supported by the vehicle body. In the suspension arm, the reinforcing arm portion is formed so that the bending rigidity in the vertical direction of the vehicle is lower than the bending stiffness in the lateral direction of the vehicle, and the thickness of the reinforcing arm portion is varied in multiple steps outward in the vehicle width direction. Suspension arm characterized by reduced.