JP2003306019A - Leaf spring type suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leaf spring type suspension device effectively restraining a windup phenomenon while dispensing with a measure on a frame side for securing a clearance between a vehicle body frame and a stopper member. <P>SOLUTION: This leaf spring type suspension device is provided with a driving shaft 3 extending along a vehicle width direction, an axle 4 for supporting the driving shaft 3, leaf springs 6 having both ends part thereof mounted on the vehicle body frame 7 and an intermediate part fixed on the axle 4, an auxiliary leaf 10 fixed on the axle 4 and the leaf springs 6 on a lower part of the leaf springs 6, and the stopper member 15 fixed on the auxiliary leaf 10 and having a spring confronting part confronting an upper surface of the leaf spring 6. The stopper member 15 is provided with a fixing lower frame 16 fixed on the auxiliary leaf 10, and an arm extending mechanism 18 capable of varying a stopper interval L between the fixing lower frame 16 and a cylindrical rubber bush 17. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of a leaf spring type suspension device using a leaf spring having a spring function and a link function, which is the most general type of rigid axle suspension.

[0002]

2. Description of the Related Art Conventionally, as a leaf spring type suspension device, for example, one disclosed in Japanese Utility Model Laid-Open No. 63-32907 is known.

FIG. 1 of this prior art publication describes a stopper member which is connected to an auxiliary leaf spring and has a portion facing the leaf spring for the purpose of suppressing windup.

The term "windup" as used herein refers to a twist that occurs in the axle (axle) when a sudden driving force or braking force is applied to the wheel. Then, in a rear-wheel drive vehicle in which the rear axle is supported by a leaf spring suspension device, the leaf spring bends due to the torque reaction force applied to the drive shaft at the time of driving by starting or accelerating,
The vertical vibration caused by this is called windup vibration.

[0005]

However, in the conventional leaf spring type suspension device, the stopper member has a structure protruding from the auxiliary leaf spring to the upper side of the vehicle. In order to secure the clearance, it is necessary to take some measures to absorb the protrusion amount of the stopper member on the frame side.

The present invention has been made in view of the above problems, and it is possible to effectively suppress the wind-up while eliminating the measures on the vehicle body side for ensuring the clearance between the vehicle body and the stopper member. An object of the present invention is to provide a leaf spring type suspension device that can be used.

[0007]

In order to achieve the above object, the present invention provides a leaf spring type suspension device including a drive shaft, an axle, a leaf spring, an auxiliary leaf member, and a stopper member. The stopper member having a spring facing portion facing the upper surface of the leaf spring has a fixing portion fixed to the auxiliary leaf member, and a distance varying mechanism capable of changing the distance between the fixing portion and the spring facing portion. did.

Here, the "spring-opposing portion of the stopper member" is a portion that exerts a stopper function of restricting displacement of the leaf spring due to contact interference with the upper surface of the leaf spring, and, for example, exerts a stopper function by metal contact. A pin member or an elastic body that exhibits a shock interference function together with a stopper function.

The "variable distance mechanism" is a mechanism that can change the distance between the fixed portion and the spring facing portion while following the displacement between the leaf spring and the auxiliary leaf member until the maximum stopper distance, which is the limit, is reached. , For example, an arm expansion / contraction mechanism and a bending link mechanism.

[0010]

As described above, in the leaf spring type suspension device of the present invention, when the leaf spring moves upward in the vehicle, the distance between the fixing portion of the stopper member and the spring facing portion is shortened, and the stopper member causes the leaf spring to move. Since it does not significantly project from the upper surface of the vehicle body, it is not necessary to take measures on the vehicle body side to secure the clearance between the vehicle body and the stopper member, while the stopper member with the maximum stopper distance allows the leaf spring and the auxiliary leaf member to be separated from each other. Windup can be effectively suppressed by regulating the relative positional relationship of the.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment for realizing a leaf spring type suspension device of the present invention will be described with reference to a first embodiment corresponding to the invention according to claims 1, 2, 3 and 4, and claim 5. A second embodiment corresponding to the invention will be described.

(First Embodiment) First, the configuration will be described. FIG. 1 is a perspective view showing a leaf spring type suspension device of the first embodiment, and FIG. 2 is a side view showing a leaf spring type suspension device of the first embodiment. It is applied to the rear axle of four-wheel drive vehicles and rear-wheel drive vehicles that use wheels as driving wheels.

1 and 2, 1 is a propeller shaft, 2 is a differential case, 3 is a drive shaft, 4
Is an axle, 5 is a wheel, 6 is a leaf spring, 7
Is a body frame (body), 8 is a spring eye, 9 is a spring shackle, 10 is an auxiliary leaf (auxiliary leaf member), 11 is a U bolt, 12 is an axle fixing plate,
Reference numeral 13 is an intermediate support plate, 14 is a nut, 15 is a stopper member, 16 is a fixed lower frame (fixed portion), 17 is a cylindrical rubber bush (spring facing portion), and 18 is an arm expansion / contraction mechanism (interval variable mechanism).

The drive shaft 3 is a shaft extending in the vehicle width direction, and the engine drive force from the propeller shaft 1 is transmitted through a differential (not shown) housed in the differential case 2. The drive shaft 3 is supported by an axle 4 which is integral with the differential case 2. A wheel 5 is fixed to the end of the drive shaft 3.

In the leaf springs 6 and 6, of the two stacked leaf springs 6 and 6, both ends of the leaf spring 6 on the vehicle upper side are connected to the vehicle body frame 7 via the spring eye 8 and the spring shackle 9. It is attached.

The auxiliary leaf 10 has a shorter length than the leaf spring 6 and is disposed in contact with the lower surface of the leaf spring 6 on the vehicle lower side of the two leaf springs 6, 6 which are stacked.

The U bolts 11 and 11 have the leaf springs 6 and 6 and the auxiliary leaf 10 which are superposed on each other.
It is a member fixed to the axle 4 at an intermediate position near the front of the vehicle. That is, the intermediate support plate 13 is interposed between the axle 4 and the leaf spring 6, the axle fixing plate 12 is arranged at the lower surface position of the axle 4, and the U bolts 11 and 11 at the vehicle front-rear position are inserted from above, and the nut is inserted. Tighten and fix with 14, 14. This allows
The auxiliary leaf 10 is fixed to the axle 4 and the leaf springs 6 and 6 below the leaf springs 6 and 6.

The stopper member 15 is arranged at a substantially intermediate position between the axle support position of the leaf spring 6 and the rear side vehicle body support position, and is fixed to the auxiliary leaf 10 on the fixed lower frame 16 and the upper surface of the leaf spring 6. Cylindrical rubber bushes 17 facing each other, and an arm extension / contraction mechanism 18 capable of changing the interval between the fixed lower frame 16 and the cylindrical rubber bushes 17.
And.

Next, the structures of the stopper member 15 and the arm extension / contraction mechanism 18 will be described with reference to FIG.

The fixed lower frame 16 is formed of an elongated flat plate and is fixed to the auxiliary leaf 10 by rivets 20. From both sides of the fixed lower frame 16, the fixed portion side connection arms 21 and 21 are extended above the vehicle, respectively.

The cylindrical rubber bush 17 is made of rubber, has a cylindrical central portion and tapered conical ends at both ends, and is attached to the bolt 22 (pin portion). The cylindrical rubber bush 17 has a spring facing surface 17a that faces the upper surface of the leaf spring 6, a vehicle body facing surface 17b that faces the lower surface (stopper surface 7a) of the vehicle body frame 7,
Have together. In addition, opposite side connecting arms 23, 23 extend from the both sides of the bolt 22 to the lower side of the vehicle, respectively.

The arm extension / contraction mechanism 18 includes fixed portion side connecting arms 21 and 21 extending from both sides of the fixed lower frame 16 toward the upper side of the vehicle, and facing portions extending from both sides of the bolt 22 toward the lower side of the vehicle. Side connecting arms 23, 23
And a fixed portion side grip portion 21a and a facing portion side grip portion 23a which are provided at the ends of both the connecting arms 21 and 23 so as to grip each other arm, respectively, and the fixed portion side grip portion 21a.
This is a mechanism that changes the stopper distance L between the fixed lower frame 16 and the cylindrical rubber bush 17 by changing the relative distance between the gripping portion 23a and the grip portion 23a.

Next, the operation will be described.

[Wind-up suppressing action] When the vehicle starts or accelerates, the axle 4, the leaf springs 6 and 6, and the auxiliary leaf 1 are driven by the torque reaction force applied to the drive shaft 3.
As indicated by the arrow in FIG. 4, the wind-up force that tries to rotate acts on 0, and the leaf springs 6 and 6 and the auxiliary leaf 10 on the rear side of the vehicle with respect to the axle 4 move downward in the vehicle around the axle 4. Displace. At the same time, auxiliary leaf 1
The stopper member 15 fixed to 0 also moves downward with the auxiliary leaf 10.

At this time, comparing the downward movement amount of the leaf springs 6 and 6 whose both ends are supported with respect to the vehicle body frame 7 with the downward movement amount of the auxiliary leaf 10 which is free at both ends and is displaced together with the axle 4. The downward movement amount of the leaf springs 6 and 6 is small, and the downward movement amount of the auxiliary leaf 10 is large, and the leaf springs 6 and 6 and the auxiliary leaf 10 are relatively separated from each other.

Therefore, while the contact between the cylindrical rubber bush 17 of the stopper member 15 and the upper surfaces of the leaf springs 6 and 6 is maintained, the distance between the stopper members 15 is changed in the direction in which the stopper distance L becomes wider. When the stopper distance L reaches the maximum stopper distance Lmax as shown in FIG. 5, the distance between the leaf springs 6 and 6 and the auxiliary leaf 10 is prevented from increasing further. in this way,
The suppression of the increase in the distance between the leaf springs 6 and 6 and the auxiliary leaf 10 by the stopper member 15 is nothing but the enhancement of the wind-up rigidity of the leaf springs 6 and 6, and the wind-up is effectively suppressed. It

When the spring facing portion of the stopper member is composed of a pin or a rod made of a metal material, when the wind spring comes into contact with the upper surface of the leaf spring, a tapping sound is generated due to the metal contact, so that the spring is opposed to the spring. A large impact force is input to the section.

On the other hand, in the leaf spring type suspension device of the first embodiment, the portion of the stopper member 15 that comes into contact with the upper surfaces of the leaf springs 6 and 6 is the cylindrical rubber bush 17, so that the striking sound due to the metal contact is generated. It can be prevented from being generated, and the impact force of the stopper member 15 on the spring facing portion can be mitigated.

[Expansion and contraction action of stopper member] As in the prior art, in the leaf spring type suspension device provided with the stopper member having a fixed stopper interval,
When the leaf spring and the auxiliary leaf member move upward in the vehicle in response to an input from the wheel or the body frame, the stopper member is in a state of protruding from the upper surface of the leaf spring.

For this reason, when the leaf spring and the auxiliary leaf member largely move upward of the vehicle at the time of bouncing or the like, the stopper member protruding from the upper surface of the leaf spring interferes with the vehicle body frame. In order to avoid the interference of the stopper member with the vehicle body, it is necessary to take measures such as providing an upwardly convex kick-up portion on the vehicle body frame or disposing the vehicle body frame itself above the vehicle.

On the other hand, in the first embodiment, as shown in FIG. 6, the stopper member 15 also assists when the leaf springs 6 and 6 and the auxiliary leaf 10 move upward in the vehicle during traveling on uneven roads. It moves above the vehicle along with the leaf 10.

In this upward movement stroke, the amount of upward movement of the leaf springs 6, 6 whose both ends are supported by the vehicle body frame 7 and both ends are free and the axle 4 is moved.
When compared with the upward movement amount of the auxiliary leaf 10 which is displaced together, the upward movement amounts of the leaf springs 6 and 6 are small,
The amount of upward movement of the auxiliary leaf 10 increases, and the leaf springs 6 and 6 and the auxiliary leaf 10 relatively approach each other.

The stopper member 1 having the minimum distance Lmin
5, the leaf springs 6 and 6 and the auxiliary leaf 10 are bundled and moved to the upper side of the vehicle as they are, and as shown in FIG. 7, the body side facing surface 17b of the cylindrical rubber bush 17 and the stopper surface 7a of the body frame 7. When they contact with each other, the cylindrical rubber bush 17 is deformed to the limit region, and the upward movement of the leaf springs 6 and 6 and the auxiliary leaf 10 is restricted.

That is, the stopper member 15 does not largely project from the upper surfaces of the leaf springs 6 and 6 toward the vehicle body frame 7 side, and there is also a vehicle body interference of the stopper member 15 such that the cylindrical rubber bush 17 comes into contact with the vehicle body frame 7. Permissible.

Therefore, by shortening the stopper member 15,
Stroke restrictions on the suspension are relaxed and a sufficient suspension stroke amount is secured, so that it is possible to prevent the ride comfort from being impaired.

In addition, unlike the prior art, it is not necessary to take measures such as providing an upwardly convex kick-up portion on the vehicle body frame 7 or disposing the vehicle body frame 7 itself above the vehicle.

Further, the stopper member 15 interferes with the vehicle body frame 7 and exerts a bound stopper function of restricting the upward movement of the leaf springs 6 and 6. Further, when the cylindrical rubber bush 17 interferes with the vehicle body frame 7, it strikes. No sound is generated.

Next, the effect will be described.

In the leaf spring type suspension device of the first embodiment, the effects listed below can be obtained.

(1) A drive shaft 3 extending in the vehicle width direction, an axle 4 for supporting the drive shaft 3, both ends attached to the vehicle body frame 7, and an intermediate portion fixed to the axle 4. The springs 6 and 6, an auxiliary leaf 10 fixed to the axle 4 and the leaf springs 6 and 6 below the leaf springs 6 and 6, and the auxiliary leaf 1
A stopper member 15 fixed to 0 and having a spring facing portion facing the upper surface of the leaf spring 6,
In the leaf spring type suspension device including the above, the stopper member 15 includes a fixed lower frame 16 fixed to the auxiliary leaf 10 and an arm extension / contraction capable of changing a stopper distance L between the fixed lower frame 16 and the cylindrical rubber bush 17. The vehicle body frame 7 for securing the clearance between the vehicle body frame 7 and the stopper member 15 since the mechanism 18 is provided.
Windup can be effectively suppressed while no countermeasures are required on the side.

(2) Since the spring facing portion 17 of the stopper member 15 is the cylindrical rubber bush 17, the cylindrical rubber bush 17 does not generate a tapping sound when the wide contact of the cylindrical rubber bush 17 with the leaf spring 6 is suppressed, and the cylindrical rubber bush 17 does not occur. The wind-up vibration can be effectively suppressed by the damping action of.

(3) Attach the spring facing portion 17 to the bolt 22.
Since the cylindrical rubber bush 17 has both a spring facing surface 17a facing the upper surfaces of the leaf springs 6 and 6 and a vehicle facing surface 17b facing the lower surface of the vehicle body frame 7, the cylindrical rubber bush 17 is There is no hammering sound when the wide contact with the leaf spring 6 is suppressed and when the cylindrical rubber bush 17 comes into contact with the vehicle body frame 7, and the sound vibration performance can be improved.

(4) The variable distance mechanism of the stopper member 15 is
Fixed part side connecting arms 21 and 21 extending from both sides of the fixed lower frame 16 to the vehicle upper side, and facing part side connecting arms 23 extending from both sides of the bolt 22 to the vehicle lower side,
23, and a fixed portion side grip portion 21a and an opposed portion side grip portion 23a which are provided at the ends of both the connecting arms 21 and 23 so as to grip each other arm, and the fixed portion side grip portion 2
Since it is the arm extension / contraction mechanism 18 that changes the stopper distance L between the fixed lower frame 16 and the cylindrical rubber bush 17 by changing the relative distance between the 1a and the facing portion side gripping portion 23a, the expansion / contraction does not project in the vehicle width direction. By the operation, the stopper distance L between the fixed lower frame 16 and the cylindrical rubber bush 17 can be changed.

(Second Embodiment) The second embodiment is an example in which the interval changing mechanism of the stopper member 15 is a bending link mechanism 28.

That is, as shown in FIG. 8, the stopper member 15 has first hinge portions 31 and 31 provided on both sides of the fixed lower frame 16 and second hinge portions 32 and 32 provided on both sides of the bolt 22. And a third hinge part 33, 33 provided in the central part of the connecting arm 34, 34 connecting the first hinge part 31, 31 and the second hinge part 32, 32, and the connecting arm divided into two. A bending link mechanism 28 is provided which changes the stopper distance L between the fixed lower frame 16 and the cylindrical rubber bush 17 depending on the bending angle θ of 34a, 34a.

Here, each of the hinge portions 31, 32 and 33 is
As shown in FIG. 8B, a hinge structure in which the link width is divided into two may be used, or as shown in FIG. 9B.
A hinge structure in which the link width is divided into three may be used.

Regarding the other constitution and operation,
Since it is similar to the embodiment, illustration and description thereof will be omitted.

Next, the effect will be described.

In the leaf spring type suspension device of the second embodiment, (1), (2) and (3) of the first embodiment are used.
In addition to the effects described above, the following effects can be obtained.

(5) The interval varying mechanism of the stopper member 15 is
First hinge portions 31, 31 provided on both sides of the fixed lower frame 16
And second hinge portions 32, 32 provided on both sides of the bolt 22.
And the first hinge portions 31, 31 and the second hinge portions 32, 32
A third arm provided at the center of the connecting arms 34, 34 for connecting
The bending link mechanism 28 having the hinge portions 33, 33 and changing the stopper distance L between the fixed lower frame 16 and the cylindrical rubber bush 17 according to the bending angle θ of the two connecting arms 34a, 34a. Therefore, the stopper interval L between the fixed lower frame 16 and the cylindrical rubber bush 17 can be changed by the smooth bending and unfolding operation by the hinge.

Although the leaf spring type suspension device of the present invention has been described above based on the first and second embodiments, the specific structure is not limited to these embodiments, and the present invention is not limited thereto. Modifications and additions of the design are permissible without departing from the gist of the invention according to each claim of the scope.

For example, in the first and second embodiments, an example in which a cylindrical rubber bush which exhibits a high impact interference function as well as a stopper function is used as the spring facing portion of the stopper member has been shown. You may use the pin member which exhibits, the leaf spring member which exhibits a shock interference function with a stopper function, etc.

In the first and second embodiments, the examples of the arm expanding / contracting mechanism 18 and the bending link mechanism 28 are shown as the distance varying mechanism. However, the distance between the fixed portion and the spring facing portion is set to the stopper distance which is the maximum limit distance. Until then, any mechanism other than the mechanisms shown in the first and second embodiments may be adopted as long as it is a mechanism that can be changed according to the displacement between the leaf spring and the auxiliary leaf member.

[Brief description of drawings]

FIG. 1 is a perspective view showing a leaf spring type suspension device of a first embodiment.

FIG. 2 is a side view showing the leaf spring type suspension device of the first embodiment.

FIG. 3 is a diagram showing a stopper member and an arm extension / contraction mechanism in the leaf spring type suspension device of the first embodiment.

FIG. 4 is a side view showing a wind-up state of the leaf spring type suspension device of the first embodiment.

FIG. 5 is a view showing a stopper member in a windup state of the leaf spring type suspension device of the first embodiment.

FIG. 6 is a side view showing a bound state of the leaf spring type suspension device of the first embodiment.

FIG. 7 is a view showing a stopper member in a bound state of the leaf spring type suspension device of the first embodiment.

FIG. 8 is a diagram showing a stopper member and a bending link mechanism in a windup state of the leaf spring type suspension device of the second embodiment.

FIG. 9 is a view showing a stopper member and a bending link mechanism in a bound state of the leaf spring type suspension device of the second embodiment.

[Explanation of symbols]

1 Propeller shaft 2 differential case 3 drive axis 4 axles 5 wheels 6 leaf spring 7 Body frame (body) 8 Spring Eye 9 Spring shackle 10 Auxiliary leaf (auxiliary leaf member) 11 U bolt 12 Axle fixing plate 13 Intermediate support plate 14 nuts 15 Stopper member 16 Fixed lower frame (fixed part) 17 Cylindrical rubber bush (spring facing part) 18-arm extension / contraction mechanism (variable spacing mechanism) 28 Bending link mechanism (variable spacing mechanism) L stopper interval (interval)

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) F16F 15/073 F16F 15/073

Claims (5)

[Claims] 1. A drive shaft extending in the vehicle width direction, an axle supporting the drive shaft, leaf springs having both ends attached to a vehicle body and an intermediate portion fixed to the axle, and the leaf spring. A leaf spring type having an auxiliary leaf member fixed below the axle and the leaf spring, and a stopper member fixed to the auxiliary leaf member and having a spring facing portion facing the upper surface of the leaf spring. In the suspension device, the stopper member includes a fixing portion fixed to the auxiliary leaf member, and a distance changing mechanism capable of changing a distance between the fixing portion and the spring facing portion. Suspension system. 2. The leaf spring type suspension device according to claim 1, wherein the spring facing portion of the stopper member is an elastic body. 3. The leaf spring type suspension device according to claim 2, wherein the elastic body is inserted into a pin portion and faces a spring facing surface that faces a top surface of the leaf spring and a bottom surface of the vehicle body. A leaf spring type suspension device, which is a cylindrical rubber bush having both facing surfaces. 4. The leaf spring type suspension device according to claim 1, wherein the variable distance mechanism of the stopper member is a fixing portion extending from both sides of the fixing portion to a vehicle upper side. Side connecting arms, facing part side connecting arms extending from both sides of the spring facing part to the lower side of the vehicle, and fixed part side holding parts and facing parts provided at the ends of both connecting arms so as to hold the opposite arm. And a part-side gripping part, and is an arm extension / contraction mechanism that changes the distance between the fixed part and the spring facing part by changing the relative distance between the fixed-side gripping part and the facing part-side gripping part. Leaf spring type suspension device. 5. The leaf spring type suspension device according to claim 1, wherein the stopper member interval varying mechanism includes first hinge portions provided on both sides of the fixing portion, and The second hinge part provided on both sides of the spring facing part, and the third hinge part provided in the central part of the connecting arm connecting the first hinge part and the second hinge part are divided into two parts. A leaf spring type suspension device comprising a bending link mechanism that changes a distance between a fixed portion and a spring facing portion according to a bending angle of an arm.