JPH0413162B2 - - Google Patents

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, transverse links (an example of suspension arms) used in strut-type front suspensions are shown in Figs.
The one shown in the figure is known (Page 106 of the Nitsusan Pulsar Maintenance Instructions published in 1982). To explain its configuration, the conventional transverse link
T' includes an arm body 1' 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 1' and is swingably supported by the vehicle body. It is composed of part 2', and
The arm body part 1' is formed by welding two press-formed plates 3', 3' top and bottom together, and the reinforcing arm part 2' is formed by two plates 3' extending from the arm body part 1'. ', 3' and this plate 3',
3', and a reinforcing member 4' which is sandwiched and connected between the reinforcing members 4' and 3'. However, in such a conventional transverse link T', the reinforcing member 4' of the reinforcing arm part 2' is a hot forged product processed by plastic deformation at a temperature higher than the recrystallization temperature of the metal material. Therefore, the thickness of the reinforcing member 4' is at least about 6 mm due to the formability of hot forging.

Therefore, as shown in FIG. 3, the reinforcing arm part 2' has a large wall thickness, and the other arm main body part 1' has only plates 3', 3', so the wall thickness is small, and the reinforcing arm part 2' has a large wall thickness. The boundary portion S' between the arm body portion 2' and the arm body portion 1' was subject to significant stress concentration when an external force was applied due to a sudden change in cross section.

Due to this stress concentration, even if statically the external force does not reach an excessive input that would cause damage, the fatigue phenomenon due to repeated loading progresses, resulting in poor durability.

Furthermore, excessive input can cause transverse link
T', stress concentration on the boundary portion S' immediately exceeds the limit of the vehicle's longitudinal bending rigidity and the limit of the vehicle's lateral bending rigidity, so the reinforcing arm part 2' begins to bend and deform. Consistency cannot be obtained in the direction leading to failure (hereinafter referred to as bending deformation failure direction).

The vehicle longitudinal bending rigidity refers to the stiffness against external forces that cause the reinforcing arm to shrink and bend in the longitudinal direction of the vehicle, and the vehicle lateral bending rigidity refers to the stiffness that prevents the reinforcing arm from causing bending and deformation in the lateral direction of the vehicle. Rigidity against external force.

For example, when the direction of bending, deformation, and damage of the reinforcing arm portion 2' is in the left-right direction of the vehicle, the following problems occur.

If the reinforcing arm portion 2' is bent and damaged in the left-right outward direction, as shown in FIG. 11, an excessive force is applied from the vehicle body support portion of the arm body portion 1' to the vehicle body, causing damage to the vehicle body. In addition, if the reinforcing arm portion 2' is bent in the left/right inward direction,
As shown in FIG. 12, the reinforcing arm portion 2' interferes with the vehicle body, causing additional damage to the vehicle body.

If the reinforcing arm part 2' is bent and damaged in the left-right direction, the arm main body part 1', on which the reinforcing arm part 2' extends, will be bent toward the rear of the vehicle, as shown in FIGS. 11 and 12. The vehicle bends, the wheels open in an inverted V-shape, and it becomes impossible to drive.

If the wheel on which the transverse link T' is provided is the driving wheel, the drive shaft will come off and the vehicle will be unable to run.

On the other hand, if the reinforcing arm part 2' shrinks and bends in the longitudinal direction of the vehicle and is damaged, the vehicle body support part of the arm body part 1' will be damaged due to excessive input, as shown in Fig. 13. It moves toward the vehicle body support part side of part 2', and the support part interval is reduced. In other words, the arm body 1' simply moves in parallel toward the rear of the vehicle, and the parallelism of the left and right wheels is maintained, allowing the vehicle to travel. Also, if it is a drive wheel, the drive shaft will be prevented from coming off.

(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 force 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 reinforcement effect and improve durability by forming a reinforcing arm portion on the arm, and can also ensure consistency in the direction of bending and deformation and damage due to excessive input.

(Structure of the Invention) An arm body disposed in the left-right direction of the vehicle, one end of which is connected to a wheel and the other end of which is swingably supported by the vehicle body;
The first body support part of the arm body includes a second body support part disposed at a predetermined distance in the longitudinal direction of the vehicle, and a second body support part extending from the middle of the arm body part toward the second body support part. A suspension arm having a reinforcing arm portion, wherein the arm main body portion and the reinforcing arm portion are formed by welding two press-molded plates vertically together, and the bending rigidity of the reinforcing arm portion in the longitudinal direction of the vehicle is is formed so that it is lower than the vehicle's lateral bending rigidity, and the thickness of the reinforcing material sandwiched and connected between the two plates of the reinforcing arm section is varied in multiple stages from the second vehicle body support section to the arm main body. This is a configuration characterized by a reduction in the amount of water.

(Effects of the Invention) Therefore, in the suspension arm of the present invention, the thickness of the reinforcing material sandwiched and connected between the two plates of the reinforcing arm portion is adjusted from the second vehicle body support portion to the arm main body portion. Because it was previously reduced in multiple stages, the stress concentration against external forces is alleviated, and the progress of fatigue caused by repeated loads can be significantly delayed, and the high reinforcement effect can improve the durability of the suspension arm. be effective.

In addition to alleviating the stress concentration mentioned above, the bending rigidity of the reinforcing arm is formed so that the bending rigidity in the longitudinal direction of the vehicle is lower than the bending rigidity in the lateral direction of the vehicle. Even when an input is applied, it is almost unaffected by stress concentration, and is governed by the static stiffness relationship described above, and the bending deformation and failure direction is constant in that the direction of bending deformation and failure is only in the direction of contraction in the longitudinal direction of the vehicle. It has the effect of preserving sex.

(Embodiment) In describing an embodiment, a transverse link (an example of a suspension arm) used in the front suspension of a front engine, front drive vehicle will be described 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 insulator, 6 is a coil spring, 7 is a strut, and 8 is a mount insulator.
is the steering knuckle, 9 is the wheel hub, 1
0 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 transverse link T.
This is a transverse link gazette for supporting the other end to the vehicle body.

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

The arm main body part 1 is formed in the vehicle width direction by welding two press-formed presses 3, 3 top and bottom together, and has a connecting hole 13 at one end that connects to the wheel side member, At the other end, a connecting short tube 14 (first
(equivalent to the vehicle body support part) is fixed. Further, the reinforcing arm section 2 includes two plates 3, 3 extending from the arm main body section 1, and the plates 3, 3.
The reinforcing member 4 and the reinforcing extension member 1 are sandwiched and connected between them.
5 (each of which corresponds to a reinforcing member), and a connecting end 4a (both of which correspond to reinforcing members) at the end of the vehicle body for connecting and supporting the transverse link gusset 12 via a vibration-proof bushing. (corresponding to the second vehicle body support part) is integrally molded.

The reinforcing member 4 is formed by cold forging and then bending and pressing, and at the end of the reinforcing member 4 there is a reinforcing extension member 15 made of a plate approximately 4 mm thick. They are integrated by welding, etc.

Next, the cross-sectional structure of the reinforcing arm portion 2 will be explained with reference to FIGS. 6 to 10. First, as shown in FIG. The reinforcing member 4 has a columnar cross section, and the middle part has a thickness of about 8 mm as shown in FIG.
The reinforcing member 4 has a flat cross-section of about 100 degrees, and the tip part is shown in FIG. As shown, only the reinforcing extension material 15 with a thickness of about 4 mm is used. In other words, the reinforcing arm portion 2
The wall thickness is reduced in two stages: a portion formed by the reinforcing member 4, a portion formed by the reinforcing extension member 15, and a portion formed only by the plates 3, 3 without reinforcement.

In addition, as shown in FIGS. 8 to 10, the reinforcing arm portion 2 has outwardly bent portions 3a, 3a formed at both ends of the plates 3, 3, to maintain a static bending rigidity relationship.
The bending rigidity in the longitudinal direction of the vehicle is made lower than the bending rigidity in the transverse direction of the vehicle.

Therefore, the transverse link T of the embodiment is
Boundary part S between reinforcement arm part 2 and arm main body part 1
Since the cross section changes stepwise due to the reinforcement extension member 15, even when an external force is applied, the stress concentration is alleviated by only a small stress concentration occurring stepwise.

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

Furthermore, when an excessive input that leads to damage is applied to the reinforcing arm part 2, due to stress concentration relaxation, the influence of stress concentration is low and the bending deformation failure state is governed by the static bending rigidity relationship, and the bending deformation failure direction It is possible to ensure consistency that bending and deformation damage occur only in the direction of contraction in the longitudinal direction of the vehicle.

Further, in the embodiment, since the reinforcing member 4 is manufactured by cold forging, it can be formed by inexpensive processing, and there are no restrictions on the wall thickness. .

Furthermore, since the cold forged 60 product has high accuracy, 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. As long as the thickness of the reinforcing material decreases in multiple stages from the vehicle body support part of the reinforcing arm part toward the arm main body part, it is not limited to the embodiments, including the meaning of "stepless".

[Brief explanation of drawings]

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
The figures are a sectional view taken along the line B-B in FIG. 1, a perspective view showing a strut type front suspension using a transverse link according to an embodiment of the present invention, and FIG.
6 is a plan view showing the main part of FIG. 5, FIG. 7 is a sectional view taken along the line CC in FIG. 6, and FIG. The figures are a cross-sectional view taken along the line D-D in Figure 6, a cross-sectional view taken along the line E-E, Figure 10 a cross-sectional view taken along the line F-F, and Figure 11 a conventional transverse link. A plan view showing a state in which the reinforcing arm part was bent outward to the left and right due to excessive input and damaged. Figure 12 shows a conventional transverse link in which the reinforcing arm was bent inward to the left and right due to excessive input and damaged. FIG. 13 is a plan view showing the state of the conventional transverse link, and is a perspective view showing a conventional transverse link in which the reinforcing arm portion is contracted and bent in the longitudinal direction of the vehicle and damaged due to excessive input. 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 material.

Claims (1)

[Claims] 1. An arm main body disposed in the left-right direction of the vehicle, one end of which is connected to a wheel and the other end swingably supported by the vehicle body, and a first vehicle body support portion of the arm main body are connected to the vehicle longitudinal direction. A suspension arm comprising: a second vehicle body support portion disposed at a predetermined distance from the arm body; and a reinforcing arm portion extending from the middle of the arm body toward the second vehicle body support portion. The reinforcing arm section and the reinforcing arm section are formed by welding two press-formed plates vertically together, and are formed so that the bending rigidity of the reinforcing arm section in the longitudinal direction of the vehicle is lower than the bending rigidity in the lateral direction of the vehicle. A suspension arm, characterized in that the thickness of the reinforcing material sandwiched and connected between two plates of the reinforcing arm portion is reduced in multiple steps from the second vehicle body support portion toward the arm main body portion.