Rear suspension of vehicle

Abstract

The present invention relates to a rear suspension device of a vehicle, comprising: a transverse auxiliary leaf spring connected to a rear axle and arranged in a transverse direction; and a first stopper mechanism and a second stopper mechanism, which come into contact with the transverse auxiliary leaf spring when the vehicle moves. The rear suspension device can improve the ride quality by using a new spring constant value generated by the transverse auxiliary leaf spring when cargo is loaded and a vehicle body frame moves downward, and restrict the rolling movement of the vehicle when rolling is caused, thereby increasing the rolling stiffness and improving the driving stability.

Description

Technical Field

[0001] The present invention relates to a rear suspension device of a vehicle, and more particularly, to a rear suspension device of a vehicle which improves riding quality and driving stability by using a lateral auxiliary leaf spring applied to a rear axle. Background Art

[0002] The suspension device of a vehicle is a device that prevents damage to the vehicle body or cargo and provides good ride quality by preventing vibration or impact from the road surface from being directly transmitted to the vehicle body while traveling.

[0003] The rear suspension device for small or medium buses, trucks, etc. includes leaf springs arranged in the longitudinal direction on the left and right sides of the vehicle. Generally, the function of such springs of the vehicle is to absorb the impact generated by the road surface and support the weight of the vehicle.

[0004] Generally speaking, springs are used to absorb shocks but require a certain level of spring constant (K) value because durability is required to support the weight of the vehicle.

[0005] However, the natural frequency of the vehicle is inversely proportional to the mass and directly proportional to the value of the spring constant K. Therefore, the larger the K value, the higher the natural frequency, and thus the ride quality deteriorates.

[0006] Therefore, a technology is needed to effectively support the weight of a vehicle according to a cargo loading state (eg, an empty state, a fully loaded state, a semi-full loaded state between the empty state and the fully loaded state) while improving ride quality.

[0007] What is provided as the prior art description is only intended to help understanding the background of the present invention and should not be considered to correspond to the prior art known to those of ordinary skill in the art. Summary of the invention

[0008] An object of the present invention is to provide a vehicle having a rear suspension device that effectively supports the weight of the vehicle and improves ride quality according to a cargo loading state (e.g., an empty state, a fully loaded state, a semi-full loaded state between the empty state and the fully loaded state) by using a longitudinal main leaf spring, a longitudinal auxiliary leaf spring, and a transverse auxiliary leaf spring applied to a rear axle. Such a rear suspension device can increase the roll stiffness of the vehicle to improve driving stability.

[0009] According to an exemplary embodiment of the present invention, a rear suspension device of a vehicle includes: a lateral auxiliary leaf spring fixed to a rear axle and arranged in a lateral direction of the vehicle; and a first stopper mechanism and a second stopper mechanism installed to be fixed to a vehicle body frame. When the vehicle body frame moves downward or tilts, the first stopper mechanism and the second stopper mechanism contact the lateral auxiliary leaf spring to limit the movement of the vehicle body frame.

[0010] The first stopper mechanism may be located on one side of the lateral auxiliary leaf spring, and the second stopper mechanism may be located on the other side of the lateral auxiliary leaf spring. The first stopper mechanism and the second stopper mechanism may each include: a stopper bracket fixedly connected to the vehicle body frame and having a stopper portion protruding above one side or the other side of the lateral auxiliary leaf spring; and an anti-roll bracket connected to the stopper bracket and protruding below one side or the other side of the lateral auxiliary leaf spring.

[0011] Each of the first stopper mechanism and the second stopper mechanism may further include an upper rubber body fixedly connected to an inner surface of the stopper portion to face the lateral auxiliary leaf spring. When the vehicle body frame moves downward, the upper rubber body may contact the lateral auxiliary leaf spring.

[0012] Each of the first stopper mechanism and the second stopper mechanism may further include a lower rubber body connected to the top surface of the anti-roll bracket to face the lateral auxiliary leaf spring. When the vehicle body frame rolls, the lower rubber body may contact the lateral auxiliary leaf spring.

[0013] The lateral auxiliary leaf spring may be configured as a multi-leaf spring having a plurality of plate springs stacked on each other.

[0014] The spring seat may be fixedly connected to the rear axle, the upper bracket may be connected to the spring seat, and the middle portion of the transverse auxiliary leaf spring may be located between the spring seat and the upper bracket, so that the transverse auxiliary leaf spring may be connected with the spring seat and the upper bracket.

[0015] The lateral auxiliary leaf spring may include a center pin integrally formed at a center point thereof in the longitudinal direction of the vehicle body frame, and the center pin may protrude in the vertical direction of the vehicle. When the lateral auxiliary leaf spring is connected between the spring seat and the upper bracket, the center pin passes through a hole formed in the spring seat and a hole formed in the upper bracket.

[0016] The rear suspension device may further include a longitudinal main leaf spring and a longitudinal auxiliary leaf spring arranged in the longitudinal direction of the vehicle body frame. The longitudinal main leaf spring and the longitudinal auxiliary leaf spring may be connected to one side and the other side of the vehicle body frame, respectively, and may be fixed to the middle portion of the rear axle in the longitudinal direction by a U-bolt. When the spring constant value of the longitudinal main leaf spring is defined as "K1", the spring constant value generated by the composite action of the longitudinal main leaf spring and the longitudinal auxiliary leaf spring is defined as "K2", and the spring constant value generated by the composite action of the longitudinal main leaf spring, the longitudinal auxiliary leaf spring and the transverse auxiliary leaf spring is defined as "K3", the relationship between K1, K2 and K3 may be K1<K2<K3.

[0017] The rear suspension device may further include a longitudinal main leaf spring disposed in the longitudinal direction of the vehicle body frame. Each longitudinal main leaf spring may be connected to one side and the other side of the vehicle body frame and may be fixed to a middle portion of the rear axle in the longitudinal direction by a U-bolt. When a spring constant value of the longitudinal main leaf spring is defined as "K1", and a spring constant value generated by a composite action of the longitudinal main leaf spring and the transverse auxiliary leaf spring is defined as "K4", a relationship between K1 and K4 may be K1<K4. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a perspective view showing a rear suspension apparatus of a vehicle according to an exemplary embodiment of the present invention.

[0019] Figure 2 It is shown Figure 1 A three-dimensional view of the part in which the lateral auxiliary leaf spring is connected.

[0020] Figure 3 yes Figure 2 Front view of .

[0021] Figure 4 yes Figure 2 Exploded three-dimensional diagram.

[0022] Figure 5 It is a view showing the operation process in an empty state, a half-full-load state, and a full-load state.

[0023] Figure 6 and Figure 7 It is a view showing the operation process when the vehicle rolls.

[0024] Figure 8 is a view showing another exemplary embodiment of a rear suspension device of a vehicle. DETAILED DESCRIPTION

[0025] Hereinafter, a rear suspension apparatus of a vehicle according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

[0026] like Figures 1 to 7As shown, the rear suspension device according to the exemplary embodiment of the present invention may include a longitudinal main leaf spring 10 and a longitudinal auxiliary leaf spring 20, which are arranged on the left and right sides of the vehicle and extend in the longitudinal direction (L) of the vehicle. Each of the longitudinal main leaf spring 10 and the longitudinal auxiliary leaf spring 20 may be connected to one side (e.g., the front end of the vehicle) and the other side (e.g., the rear end of the vehicle) of the vehicle body frame 1, and may be installed to be fixed to the middle part of the rear axle 5 in the longitudinal direction by the U-bolt 3. The rear suspension device may further include: a transverse auxiliary leaf spring 30, which is fixed to the rear axle 5 and is arranged in the transverse direction (T) of the vehicle, which is the axial direction of the rear axle 5; and a first stopper mechanism 40 and a second stopper mechanism 50, which are installed to be fixed to the vehicle body frame 1. When the vehicle body frame 1 moves downward or tilts, the first and second stopper mechanisms 40 and 50 may contact the transverse auxiliary leaf spring 30 to limit the movement of the vehicle body frame 1.

[0027] The longitudinal main leaf spring 10 , the longitudinal auxiliary leaf spring 20 , and the transverse auxiliary leaf spring 30 may all be configured as a multi-leaf spring having multiple layers of leaf springs stacked on each other.

[0028] The first stopper mechanism 40 and the second stopper mechanism 50 may be fixedly connected to the left and right sides of the vehicle body frame 1, respectively, and are respectively located on one side (left end) and the other side (right end) of the lateral auxiliary leaf spring 30. The first stopper mechanism 40 and the second stopper mechanism 50 may include the same components.

[0029] The first stopping mechanism 40 and the second stopping mechanism 50 may each include: a stopping bracket 41 or 51, which is fixedly connected to the vehicle body frame 1, wherein the stopping portion 41a or 51a protrudes above one side (left end) or the other side (right end) of the lateral auxiliary leaf spring 30; an anti-roll bracket 42 or 52, which is connected to the stopping bracket 41 or 51 and protrudes below one side (left end) or the other side (right end) of the lateral auxiliary leaf spring 30.

[0030] The first and second stopping mechanisms 40 and 50 may each further include: an upper rubber body 43 or 53, which is fixedly connected to the inner surface of the stopping portion 41a or 51a to face the lateral auxiliary leaf spring 30 and contacts the lateral auxiliary leaf spring 30 when the vehicle body frame 1 moves downward; and a lower rubber body 44 or 54, which is connected to the top surface of the anti-roll bracket 42 or 52 to face the lateral auxiliary leaf spring 30 and contacts the lateral auxiliary leaf spring 30 when the vehicle body frame 1 tilts.

[0031] The upper rubber body 43 or 53 and the lower rubber body 44 or 54 prevent noise generation and absorb impact when contacting the lateral auxiliary leaf spring 30, thereby improving the durability of the system.

[0032] According to an exemplary embodiment of the present invention, the spring seat 61 can be fixedly connected to the rear axle 5, the upper bracket 62 is connected to the spring seat 61 by a plurality of bolts 63, and the middle portion of the transverse auxiliary leaf spring 30 is located between the spring seat 61 and the upper bracket 62, so that the transverse auxiliary leaf spring 30 is connected together with the spring seat 61 and the upper bracket 62.

[0033] According to an exemplary embodiment of the present invention, the lateral auxiliary leaf spring 30 may include a center pin 31 integrally formed at a center point thereof in the longitudinal direction (L), and the center pin 31 protrudes in the vertical direction (V) of the vehicle. When the lateral auxiliary leaf spring 30 is connected between the spring seat 61 and the upper bracket 62, the center pin 31 passes through a hole 61a formed in the spring seat 61 and a hole 62a formed in the upper bracket 62, thereby being able to fix the position of the lateral auxiliary leaf spring 30 to prevent the lateral auxiliary leaf spring 30 from moving in the lateral direction.

[0034] According to an exemplary embodiment of the present invention, when the spring constant value of the longitudinal main leaf spring 10 is defined as K1, the spring constant value generated by the combined action of the longitudinal main leaf spring 10 and the longitudinal auxiliary leaf spring 20 is defined as K2, and the spring constant value generated by the combined action of the longitudinal main leaf spring 10, the longitudinal auxiliary leaf spring 20 and the transverse auxiliary leaf spring 30 is defined as K3, the relationship between K1, K2 and K3 is K1<K2<K3.

[0035] In the cargo loading state or the empty state, the vertical movement of the rear axle 5 can be controlled only by using the elastic force of the longitudinal main leaf spring 10. The spring constant value generated at this time is K1, which is the lowest spring constant value.

[0036] In the half-full load state, due to the load weight, the body frame 1 can be further lower than the body frame 1 in the unloaded state. At this time, both sides (ends) of the longitudinal auxiliary leaf spring 20 can contact the stopper, and the spring constant value K2 is generated by the combined action of the longitudinal main leaf spring 10 and the longitudinal auxiliary leaf spring 20.

[0037] In the fully loaded state, the vehicle body frame 1 can be further lower than the vehicle body frame 1 in the half loaded state, and both sides (ends) of the transverse auxiliary leaf spring 30 can contact the stop brackets 41 and 51. At this time, the spring constant value K3 is generated by the combined action of the longitudinal main leaf spring 10, the longitudinal auxiliary leaf spring 20 and the transverse auxiliary leaf spring 30.

[0038] Hereinafter, the operation of the rear suspension apparatus according to the exemplary embodiment of the present invention will be described.

[0039] The rear suspension apparatus according to an exemplary embodiment of the present invention may include a longitudinal main leaf spring 10 , a longitudinal auxiliary leaf spring 20 , and a transverse auxiliary leaf spring 30 .

[0040] exist Figure 5, the left graph may describe the cargo loading state as an empty state, the right graph may describe a full state, and the middle graph may describe a half-full state between the empty state and the full state.

[0041] In the unloaded state, the vertical movement of the rear axle 5 can be controlled by using the elastic force of the longitudinal main leaf spring 10 with the lowest spring constant value. At this time, the lowest spring constant value K1 is generated.

[0042] In the semi-full load state, the vertical movement of the rear axle 5 can be controlled by using the elastic force of the longitudinal auxiliary leaf spring 20. At this time, the spring constant value K2 is generated by the composite action of the longitudinal main leaf spring 10 and the longitudinal auxiliary leaf spring 20.

[0043] In the semi-full-load state, the vehicle body frame 1 may be further lower than the vehicle body frame 1 in the unloaded state due to the load weight (arrow M1). In the unloaded state and the semi-full-load state, both sides (ends) of the lateral auxiliary leaf spring 30 may be kept out of contact with the upper rubber bodies 43 and 53 connected to the stop brackets 41 and 51, respectively.

[0044] When the vehicle is changed from a semi-loaded state to a fully loaded state by applying a larger load weight thereto, the vehicle body frame 1 may be further lowered (arrow M2), and thus both sides (ends) of the lateral auxiliary leaf spring 30 finally come into contact with the upper rubber bodies 43 and 53 respectively connected to the stop brackets 41 and 51. From this point on, K3 as a new spring constant value may be generated by the combined action of the longitudinal main leaf spring 10, the longitudinal auxiliary leaf spring 20, and the lateral auxiliary leaf spring 30.

[0045] Therefore, the new spring constant value K3 can subdivide the existing high spring constant value K2, so as to effectively support the weight of the vehicle and improve the ride quality according to the cargo loading state (empty state, full state, semi-full state between the empty state and the full state).

[0046] In the conventional structure including only the longitudinal main leaf spring and the longitudinal auxiliary leaf spring, the spring constant value is optimal only in the no-load state or the fully loaded state. However, in the case of low mass and high spring constant value, that is, the half-loaded state, the natural frequency increases rapidly, so the ride quality becomes very poor.

[0047] The rear suspension device according to an exemplary embodiment of the present invention can effectively support the weight of the vehicle according to the cargo loading state (for example, an empty state, a fully loaded state, a semi-full loaded state between the empty state and the fully loaded state), while improving the riding quality by reducing the existing spring constant value K2 generated by the longitudinal auxiliary leaf spring 20 and generating a new spring constant value K3 generated by the transverse auxiliary leaf spring 30, so that the spring constant value can be optimal in the semi-full loaded state (i.e., 1 / 2GVW, gross vehicle weight) inevitably generated when loading cargo.

[0048] According to an exemplary embodiment of the present invention, Figure 6 shows a situation where the vehicle body frame 1 rolls counterclockwise about the roll center due to the lateral force acting on the vehicle (arrow R1), and Figure 7 The case where the vehicle body frame 1 rolls in the clockwise direction (arrow R2) is shown. At the time of the rolling motion of the vehicle, the vehicle body frame 1 rotates, and one side (left end) or the other side (right end) of the lateral auxiliary leaf spring 30 contacts one of the lower rubber bodies 44 and 54 connected to the anti-roll brackets 42 and 52, respectively, so that the rolling motion can be restricted, and therefore, the rolling rigidity can be increased and the driving stability can be improved.

[0049] For a light truck or a small bus, which may be lighter in weight, the rear suspension may include a longitudinal main leaf spring 10 and a transverse auxiliary leaf spring 30 without a longitudinal auxiliary leaf spring, such as Figure 8 shown.

[0050] At this time, the spring constant value of the longitudinal main leaf spring 10 may be defined as K1, and the spring constant value generated by the combined action of the longitudinal main leaf spring 10 and the transverse auxiliary leaf spring 30 may be defined as K4. The relationship between K1 and K4 may be K1<K4. The newly generated spring constant value K4 may also improve the ride quality and limit the roll motion, thereby improving the driving stability.

[0051] As described above, the rear suspension device according to the exemplary embodiment of the present invention includes: the lateral auxiliary leaf spring 30, which is connected to the rear axle 5 and arranged in the lateral direction; and the first stopper mechanism 40 and the second stopper mechanism 50, which, when the vehicle moves, come into contact with the lateral auxiliary leaf spring 30. When the cargo is loaded and the vehicle body frame 1 moves downward, by using the new spring constant value generated by the lateral auxiliary leaf spring 30, the rear suspension device can effectively support the weight of the vehicle and improve the ride quality according to the cargo loading state (empty state, full load state, semi-full load state between the empty state and the full load state).

[0052] Furthermore, the present invention has the advantage that when rolling is caused by a lateral force acting on the vehicle, the rolling motion of the vehicle can be restricted by using the lateral auxiliary leaf spring 30 and the first and second stopper mechanisms 40 and 50, and thus, the rolling rigidity can be increased and the driving stability can be improved.

[0053] While the present invention has been shown and described with respect to the particular embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention as defined by the following claims.

Claims

1. A rear suspension device for a vehicle, comprising: a transverse auxiliary leaf spring fixed to the rear axle and arranged in the transverse direction of the vehicle; as well as The first stopper mechanism and the second stopper mechanism are mounted to be fixed to the vehicle body frame, When the vehicle body frame moves downward or tilts, the first stop mechanism and the second stop mechanism contact the lateral auxiliary leaf spring to limit the movement of the vehicle body frame. wherein the first stop mechanism is located on one side of the transverse auxiliary leaf spring, and the second stop mechanism is located on the other side of the transverse auxiliary leaf spring, and Each of the first stop mechanism and the second stop mechanism comprises: a stopper bracket fixedly connected to the vehicle body frame and having a stopper portion protruding above the one side or the other side of the lateral auxiliary leaf spring; and An anti-roll bracket is connected to the stop bracket and protrudes below the one side or the other side of the lateral auxiliary leaf spring.

2. The rear suspension device according to claim 1, wherein: Each of the first stopper mechanism and the second stopper mechanism further includes an upper rubber body fixedly connected to an inner surface of the stopper portion to face the lateral auxiliary leaf spring, the upper rubber body contacting the lateral auxiliary leaf spring when the vehicle body frame moves downward.

3. The rear suspension device according to claim 1, wherein: Each of the first stopper mechanism and the second stopper mechanism further includes a lower rubber body connected to a top surface of the anti-roll bracket to face the lateral auxiliary leaf spring, the lower rubber body contacting the lateral auxiliary leaf spring when the vehicle body frame rolls.

4. The rear suspension device according to claim 1, wherein: The transverse auxiliary leaf spring is configured as a multi-leaf spring having a plurality of layers of leaf springs stacked on one another.

5. The rear suspension device according to claim 1, in, A spring seat is fixedly connected to the rear axle, The upper bracket is connected to the spring seat, and The middle portion of the transverse auxiliary leaf spring is located between the spring seat and the upper bracket, so that the transverse auxiliary leaf spring is connected to the spring seat and the upper bracket.

6. The rear suspension device according to claim 5, in, The lateral auxiliary leaf spring includes a center pin integrally formed at a center point of the lateral auxiliary leaf spring in the longitudinal direction of the vehicle body frame, the center pin protruding in the vertical direction of the vehicle, and When the lateral auxiliary leaf spring is connected between the spring seat and the upper bracket, the center pin passes through the hole formed in the spring seat and the hole formed in the upper bracket.

7. The rear suspension device according to claim 1, further comprising a longitudinal main leaf spring and a longitudinal auxiliary leaf spring arranged in the longitudinal direction of the vehicle body frame, in, Each of the longitudinal main leaf spring and the longitudinal auxiliary leaf spring is connected to one side and the other side of the vehicle body frame and is fixed to the middle portion of the rear axle in the longitudinal direction by a U-bolt, Among them, when the spring constant value of the longitudinal main leaf spring is defined as "K1", the spring constant value generated by the combined action of the longitudinal main leaf spring and the longitudinal auxiliary leaf spring is defined as "K2", and the spring constant value generated by the combined action of the longitudinal main leaf spring, the longitudinal auxiliary leaf spring and the transverse auxiliary leaf spring is defined as "K3", the relationship between K1, K2 and K3 is K1<K2<K3.

8. The rear suspension device according to claim 1, further comprising a longitudinal main leaf spring provided along the longitudinal direction of the vehicle body frame, in, Each of the longitudinal main leaf springs is connected to one side and the other side of the vehicle body frame and is fixed to the middle portion of the rear axle in the longitudinal direction by a U-bolt, When the spring constant value of the longitudinal main leaf spring is defined as "K1", and the spring constant value generated by the combined action of the longitudinal main leaf spring and the transverse auxiliary leaf spring is defined as "K4", the relationship between K1 and K4 is K1<K4.

Images