JP3998985B2 - Parent-child spring suspension system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a parent-child spring suspension device, and more particularly to a technique for improving vehicle stability during a cargo handling operation.
[0002]
[Prior art]
In commercial vehicles such as trucks, load fluctuations between empty and loaded vehicles are large, so a parent-child spring suspension system is adopted to achieve both a comfortable ride when empty and load support during loading. There are many cases.
The parent-child spring type suspension device includes a parent-child spring composed of a main spring and an auxiliary spring arranged in the vertical direction with an intermediate portion fixed to the axle, a spring bracket for coupling both ends of the main spring to the vehicle body, and a vehicle body. And a helper bracket integrally formed with contact sheets that come into contact with the upper surfaces of both end portions of the auxiliary spring when the deflection of the main spring reaches a predetermined value or more. When the load is light, such as when the vehicle is empty, only the main spring works to improve riding comfort.On the other hand, when the load is heavy, such as when loading a vehicle, the upper surfaces of both ends of the auxiliary spring are in contact with the contact sheet. Thus, the main spring and the auxiliary spring cooperate to support a heavy load.
[0003]
[Problems to be solved by the invention]
By the way, when carrying out the cargo handling work in an empty state, only the main spring is working, so the spring constant of the parent-child spring is small. For this reason, the roll rigidity of the vehicle is low, and the vehicle is greatly inclined during loading and unloading work, and the vehicle stability may be impaired. Further, when cargo handling work is carried out with a trolley using a platform in a distribution warehouse or the like, it is difficult to use the trolley due to the inclination of the vehicle, and the workability may be reduced.
[0004]
Accordingly, in view of the above-described conventional problems, the present invention provides a parent-child spring type suspension device that improves vehicle stability during a cargo handling operation by applying a preload to the parent-child spring as necessary. With the goal.
[0005]
[Means for Solving the Problems]
Therefore, according to the first aspect of the present invention, a parent-child spring composed of a main spring and an auxiliary spring arranged in the vertical direction while the intermediate portion is fixed to the axle, and a spring for coupling both ends of the main spring to the vehicle body. When the main spring is bent to a predetermined value or more, the bracket is fixed to the vehicle body , the helper bracket is integrally formed with a contact sheet that contacts the upper surface of both ends of the auxiliary spring, and the winding is fixed to one of the vehicle body and the axle. A parent-child spring suspension device comprising: a take-up device; a rope wound around the take-up device while the tip end is fixed to the other of the vehicle body or the axle; and a cylindrical casing in which the rope is housed. In the above, the casing is formed with a slit for accommodating the rope in the inner space over the entire length thereof.
[0006]
According to such a configuration, when the winding device is actuated to wind the rope, and the vehicle body is moved in the axle direction against the repulsive force of the parent and child spring, the bending of the parent and child spring gradually increases. When the movement of the vehicle body is stopped at the point where the bending of the parent-child spring becomes equal to or greater than the intersection, the parent-child spring is in a state (preload state) in which a load corresponding to the bending is applied in a pseudo manner. When the cargo handling operation is performed in this preloaded state, a load corresponding to the product load amount acts on the parent / child spring, but since the parent / child spring is in the preloaded state, the bending of the parent / child spring does not change at all (however, the preloading is not performed). Within the range according to.
[0007]
For this reason, the vehicle is not inclined during the cargo handling operation, and the vehicle stability during the cargo handling operation is improved. Further, even when a cargo handling work is performed with a trolley using a platform in a distribution warehouse or the like, the use of the trolley is facilitated and the workability is improved because the vehicle does not tilt. Furthermore, since the height of the vehicle can be adjusted, for example, the height of the cargo compartment of the truck can be made substantially the same as the height of the platform, and the efficiency of the cargo handling work is improved. At this time, since the rope is housed in the casing, even if the rope is slackened with the bending of the parent-child spring, for example, the rope is not entangled with the vehicle-mounted device, and the vehicle is reliably prevented from being damaged.
[0008]
The invention according to claim 2 is characterized in that the casing is made of a soft resin rubber .
According to this configuration, the casing is reduced in weight.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a parent-child spring suspension device for a truck to which the present invention is applied. An intermediate portion of a parent-child spring 16 extending in the vehicle front-rear direction is fixed to upper surfaces of both end portions of the axle 10 by a fastening member including a U bolt 12 and a nut 14. The parent-child spring 16 includes a main spring 16A and an auxiliary spring 16B in which a plurality of leaves are stacked, and has a shape in which the main spring 16A and the auxiliary spring 16B are arranged in the vertical direction. The front end portion of the main spring 16A is pin-coupled to a spring bracket 20 fixed to the side surface of the side member 18 of the vehicle body. On the other hand, the rear end portion of the main spring 16A is pin-coupled to a spring bracket 24 fixed to the side surface of the side member 18 with a shackle 22 interposed. Further, on the side surface of the side member 18, a helper bracket 26 integrally formed with a contact sheet 26A with which the upper surfaces of both end portions of the auxiliary spring 16B abut when the deflection of the main spring 16A due to vehicle weight becomes a predetermined value or more is fixed.
[0012]
According to such a parent-child spring type suspension device, the upper surface of both ends of the auxiliary spring 16B does not contact the contact sheet 26A of the helper bracket 26 in a light load state where the deflection of the main spring 16A is less than a predetermined value. A buffering effect is achieved only by the spring 16A. For this reason, the spring constant of the whole parent-child spring 16 becomes the same as the spring constant of the main spring 16A, and the riding comfort is improved. On the other hand, in a heavy load state where the deflection of the main spring 16A is greater than or equal to a predetermined value, the upper surfaces of both end portions of the auxiliary spring 16B abut against the contact sheet 26A of the helper bracket 26, and buffer by the cooperation of the main spring 16A and the auxiliary spring 16B. The effect is played. For this reason, the spring constant of the whole parent-child spring 16 becomes a value obtained by adding the spring constant of the main spring 16A and the spring constant of the auxiliary spring 16B, so that a heavy load can be supported. The characteristics of the parent-child spring 16 are greatly changed at the point (intersection point) where the upper surfaces of both ends of the auxiliary spring 16B come into contact with the contact sheet 26A, as shown in FIG.
[0013]
Further, as a feature of the present invention, there is provided moving means for moving the vehicle body in the direction of the axle 10 against the repulsive force of the parent-child spring 16. The moving means includes, for example, a motor 28 as a winding device fixed to a cross member (not shown) of the vehicle body, and a wire 30 as a rope wound around the motor 28. And the front-end | tip part of the wire 30 is fixed to the rear-end part of 10 A of differential gear cases located in the axle 10 center part, for example. In addition, while fixing the motor 28 to the axle 10, you may make it fix the front-end | tip part of the wire 30 to a vehicle body. When the motor output is low, a reduction gear may be connected to the motor 28 as a winding device. Furthermore, the moving means may be provided not only at the central portion of the axle 10 but also at both end portions of the axle 10, for example.
[0014]
In such a configuration, when the motor 28 is operated to wind the wire 30, the vehicle body moves in the direction of the axle 10 against the repulsive force of the parent-child spring 16, and the bending of the parent-child spring 16 gradually increases. And the motor 28 is stopped at the point (refer FIG. 2) where the bending of the parent-child spring 16 became more than an intersection. Then, the parent-child spring 16 is in a state (preload state) in which a load corresponding to the bending is applied in a pseudo manner, and its elongation is restricted by the wire 30. Therefore, as shown in the schematic diagram of FIG. The tension W corresponding to the bending acts on the.
[0015]
When the cargo handling operation is performed in this preloaded state, a load corresponding to the product load amount acts on the parent-child spring 16. However, since the parent-child spring 16 is in the preloaded state, the tension W of the wire 30 is reduced by the amount of the product load, and the bending of the parent-child spring 16 does not change at all (however, it is limited to the range corresponding to the preload. ).
For this reason, the vehicle does not tilt during the cargo handling operation, and the vehicle stability during the cargo handling operation can be improved. Further, even when a cargo handling operation is performed with a trolley using a platform in a distribution warehouse or the like, the use of the trolley can be facilitated and workability can be improved because the vehicle does not tilt. Further, as a secondary effect, the vehicle height can be adjusted by the moving means. For example, the height of the cargo compartment of the truck can be made substantially the same as the height of the platform, thereby improving the efficiency of the cargo handling work. It can also be made.
[0016]
It is desirable that the motor 28 as the winding device be configured to freely release the winding of the wire 30 in accordance with the relative movement between the vehicle body and the axle 10 when not operating. In this way, during normal running, even if the bending of the parent and child spring 16 decreases following the unevenness of the road surface, the winding of the wire 30 is released freely, so that the riding comfort is reduced, the wire 30 is damaged, etc. Can be reliably prevented.
[0017]
Moreover, as shown in FIG. 4, you may make it provide the casing 32 in which the wire 30 is accommodated at least among the motor 28 and the wire 30 which comprise a moving means. The casing 32 is made of a lightweight member such as a soft resin rubber, and has a substantially cylindrical portion 32A fitted to the outer periphery of the main body 28A of the motor 28, and a substantially truncated square tube whose sectional area gradually decreases toward the tip. And a rectangular tube portion 32B having a shape. A slit 32C for accommodating the wire 30 in the internal space of the rectangular tube portion 32B is formed on the surfaces of the cylindrical portion 32A and the rectangular tube portion 32B facing the vehicle body (not shown). And when attaching the casing 32, after accommodating the wire 30 in the internal space of the rectangular tube part 32B through the slit 32C, the cylindrical part 32A is fitted to the outer periphery of the body 28A of the motor 28, and this is fastened with a band or the like. What is necessary is just to fix through the member 34. In addition, the attachment method and shape of a casing are not restricted to the structure of this embodiment, What kind of structure may be sufficient if it is a structure which covers a wire.
[0018]
In this way, even if the wire 30 is loosened with the bending of the parent-child spring 16, for example, the wire 30 is not entangled with the vehicle-mounted device, and the vehicle can be prevented from being damaged.
Needless to say, the present invention is not limited to the truck shown in the present embodiment but can be applied to other vehicles. And in the vehicle of a monocoque body, what is necessary is just to fix the front-end | tip part of the motor 28 or the wire 30 to the body reinforced as needed.
[0019]
【The invention's effect】
As described above, according to the first aspect of the present invention, the vehicle is not inclined during the cargo handling operation, and the vehicle stability during the cargo handling operation can be improved. Further, even when a cargo handling operation is performed with a trolley using a platform in a distribution warehouse or the like, the use of the trolley can be facilitated and the workability can be improved because the vehicle does not tilt. Furthermore, since the height of the vehicle can be adjusted, for example, the height of the cargo compartment of the truck can be made substantially the same as the height of the platform, and the efficiency of the cargo handling work can be improved. At this time, since the rope is housed in the casing, even if the rope is loosened due to the bending of the parent-child spring, for example, the rope does not get entangled with the on-vehicle equipment, and the vehicle can be reliably prevented from being damaged. .
[0020]
According to invention of Claim 2, a casing can be reduced in weight.
[Brief description of the drawings]
FIG. 1 is a structural diagram of a truck parent-child spring suspension device to which the present invention is applied. FIG. 2 is a characteristic diagram of a parent-child spring. FIG. 3 is a schematic diagram for explaining a preload state. Is an explanatory diagram of the mounting state, (B) is a front view, (C) is a perspective view.
DESCRIPTION OF SYMBOLS 10 Axle 16 Parent-child spring 16A Main spring 16B Auxiliary spring 18 Side member 20 Spring bracket 24 Spring bracket 26 Helper bracket 26A Contact sheet 28 Motor 30 Wire 32 Casing
32C slit

Claims (2)

A parent-child spring composed of a main spring and an auxiliary spring arranged in the vertical direction while the intermediate portion is fixed to the axle;
A spring bracket for coupling both ends of the main spring to the vehicle body;
A helper bracket integrally formed with a contact sheet that is fixed to the vehicle body and contacts the upper surfaces of both end portions of the auxiliary spring when the deflection of the main spring exceeds a predetermined value;
A winding device fixed to one of the vehicle body or the axle;
A rope that is wound around the winding device while the tip is fixed to the other of the vehicle body or the axle;
A cylindrical casing in which the wire is stored;
Comprising
A parent-child spring suspension device , wherein the casing is formed with a slit for accommodating the rope in the internal space over its entire length . 2. The parent-child spring suspension device according to claim 1 , wherein the casing is made of a soft resin rubber .

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