JP2003211931A - Load and empty elliptic spring type suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve stability of a vehicle during loading and unloading operation. <P>SOLUTION: A load and empty elliptic spring type suspension device is composed of a load and empty elliptic spring 16 composed of a main spring 16A and an auxiliary spring 16B fixed on an axle 10 at center parts thereof and arranged in a vertical direction, spring brackets 20, 24 jointing both end parts of the main spring 16 on a side member 18 of a vehicle body with pins, a helper bracket 26 having a contact seat 26A fixed on the side member 18 and getting into contact with an upper surface of both end parts of the auxiliary spring 16B when deflection of the main spring exceeds a designated value formed as one body, a motor 28 and a wire 30 as transferring means transferring the vehicle body to a direction of the axle 10 against repulsion force of the load and empty elliptic spring 16. The motor 28 winds the wire 30 to act preload on the load and empty elliptic spring 16 and to prevent the vehicle from inclining during loading and unloading operation. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parent-child spring type suspension device, and more particularly to a technique for improving vehicle stability during cargo handling work.

[0002]

2. Description of the Related Art In a commercial vehicle such as a truck, a load variation between when the vehicle is empty and when the vehicle is loaded is large. Devices are often employed. In the parent-child spring type suspension device, the middle part is fixed to the axle,
A parent-child spring composed of a main spring and an auxiliary spring arranged in the up-down direction, a spring bracket for connecting both ends of the main spring to the vehicle body, and an auxiliary spring fixed to the vehicle body when the deflection of the main spring exceeds a predetermined value. And a helper bracket integrally formed with a contact sheet that abuts the upper surfaces of both ends of the helper bracket. When the vehicle is lightly loaded, such as when the vehicle is empty, only the main spring works to improve riding comfort, while when the vehicle is heavyly loaded, the upper surfaces of both ends of the auxiliary spring contact the contact sheet. Thus, the main spring and the auxiliary spring cooperate to support a heavy load.

[0003]

By the way, when carrying out cargo handling work in an empty state, only the main spring is working, so that the spring constant of the parent-child spring becomes small. For this reason, the roll rigidity of the vehicle is low, and during loading and unloading work, the vehicle is greatly inclined with the loading and unloading of the load, which may impair vehicle stability. In distribution warehouses,
When carrying out a cargo handling work using a platform using a platform, there is a risk that the vehicle is difficult to use due to the inclination of the vehicle and the workability is reduced.

In view of the conventional problems as described above, the present invention provides a parent-child spring type suspension device in which the parent-child spring is preloaded as necessary to improve vehicle stability during cargo handling work. The purpose is to provide.

[0005]

For this reason, in the invention according to claim 1, a parent-child spring composed of a main spring and an auxiliary spring arranged in the up-down direction while the intermediate portion is fixed to the axle, and the main spring of the main spring. A spring bracket that connects both ends to the vehicle body, and a helper bracket that is fixed to the vehicle body and that has contact sheets that are in contact with the upper surfaces of both ends of the auxiliary spring when the deflection of the main spring exceeds a predetermined value.
The parent-child spring type suspension device is configured to include a moving unit that moves the vehicle body in the axle direction against the repulsive force of the parent-child spring.

According to this structure, when the vehicle body is moved in the axle direction against the repulsive force of the parent-child spring, the bending of the parent-child spring gradually increases. Then, 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 becomes a state in which a load corresponding to the bending acts in a pseudo manner (preload state). When carrying out cargo handling work in this preload state, the load corresponding to the product load amount acts on the parent-child spring, but since the parent-child spring is in the preload state, the bending of the parent-child spring does not change at all (however, preload Limited to the range according to).

Therefore, the vehicle does not tilt during the cargo handling work, and the stability of the vehicle during the cargo handling work is improved.
Further, even in the case where the platform is used for cargo handling work in a distribution warehouse or the like, the vehicle is not tilted, so that the truck is easy to use and the workability is improved. Furthermore, since the height of the vehicle can be adjusted, for example, the height of the luggage compartment of the truck can be made substantially the same as the height of the platform, which improves the efficiency of cargo handling work.

According to a second aspect of the present invention, the moving means includes a winding device fixed to one of a vehicle body and an axle.
And a cord wound around the winding device,
The leading end of the cord is fixed to the other of the vehicle body and the axle. According to this configuration, the moving means is
Since it is composed of the winding device and the rope, the moving means can be easily realized by diverting the existing motor and wire, for example.

According to a third aspect of the present invention, the winding device is characterized in that, when the winding device is not in operation, the winding of the cord is freely released due to the relative movement of the vehicle body and the axle. According to such a configuration, during normal traveling, even if the bending of the parent-child spring becomes small following the unevenness of the road surface, the winding of the rope is released, so that the riding comfort is reduced and the rope is damaged. Certainly prevented.

The invention according to claim 4 is characterized in that a casing for accommodating the cord is provided. According to such a configuration, even if the cord is loosened due to the bending of the parent-child spring, for example, the cord will not be entangled with the vehicle-mounted device, and damage to the vehicle can be reliably prevented.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a parent-child spring type suspension device for a truck to which the present invention is applied. Axle 10
A parent and child spring 16 extending in the vehicle front-rear direction is provided on the upper surfaces of both ends of the vehicle by a fastening member including a U bolt 12 and a nut 14.
The middle part of is fixed. The parent-child spring 16 is configured to include a main spring 16A in which a plurality of leaves are stacked and an auxiliary spring 16B, and has a shape in which the main spring 16A and the auxiliary spring 16B are vertically arranged. The front end portion of the main spring 16A is pin-connected 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 of the main spring 16A is pin-coupled to the spring bracket 24 fixed to the side surface of the side member 18 with the shackle 22 interposed. Further, on the side surface of the side member 18, when the deflection of the main spring 16A due to the vehicle weight becomes a predetermined value or more, the upper surfaces of both ends of the auxiliary spring 16B come into contact with the contact sheet 26A.
The helper bracket 26 integrally formed with is fixed.

According to this parent-child spring type suspension device, the upper surfaces of both ends of the auxiliary spring 16B do not contact the contact sheet 26A of the helper bracket 26 in a light load state in which the deflection of the main spring 16A is less than a predetermined value. Therefore, the cushioning action is provided only by the main spring 16A. Therefore, the spring constant of the parent-child spring 16 as a whole is the main spring 16A.
It becomes the same as the spring constant of, and the ride comfort is improved. On the other hand, in a heavy load state in which the deflection of the main spring 16A is equal to or greater than a predetermined value, the upper surfaces of both ends of the auxiliary spring 16B contact the contact sheet 26A of the helper bracket 26,
A cushioning action is provided by the cooperation of the main spring 16A and the auxiliary spring 16B. Therefore, the spring constant of the entire 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, and a heavy load can be supported. The characteristics of such a parent-child spring 16 are shown in FIG.
As shown in FIG. 7, the upper surfaces of the both ends of the auxiliary spring 16B are largely changed at the point (contact point) where the upper surface of both ends contact the contact sheet 26A.

Further, as a feature of the present invention, the parent-child spring 16
A moving means for moving the vehicle body in the direction of the axle 10 against the repulsive force of the vehicle is provided. 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 cord wound around the motor 28. And wire 3
The front end portion of 0 is fixed to the rear end portion of the differential gear case 10A located in the central portion of the axle 10, for example. The motor 28 may be fixed to the axle 10 and the tip of the wire 30 may be fixed to the vehicle body. Further, when the motor output is low, the speed reducer may be connected to the motor 28 and used 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, respectively.

In this structure, when the motor 28 is operated and the wire 30 is wound up, the vehicle body moves in the direction of the axle 10 against the repulsive force of the parent-child spring 16, and the parent-child spring 16
The flexure of gradually increases. Then, at the point where the bending of the parent-child spring 16 exceeds the intersection (see FIG. 2), the motor 28
To stop. Then, the parent-child spring 16 enters a state in which a load corresponding to the bending acts in a pseudo manner (preload state), and the wire 30 restricts the extension thereof.
As shown in the schematic view of FIG. 3, the tension W corresponding to the bending acts on the wire 30.

When carrying out the cargo handling work 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 a preloaded state, the tension W of the wire 30 is only reduced by the product load amount, and the bending of the parent-child spring 16 does not change at all (however, within the range corresponding to the preload). ). Therefore, the vehicle does not tilt during the cargo handling work, and the vehicle stability during the cargo handling work can be improved. Further, even in the case where the platform is used for cargo handling work in a distribution warehouse or the like, the vehicle is not tilted, so that the truck can be used easily and the workability can be improved. Further, as a secondary effect, since the vehicle height can be adjusted by the moving means, for example,
The height of the luggage compartment of the truck can be made substantially the same as the height of the platform, and the efficiency of cargo handling work can be improved.

The motor 28, which is a winding device, is in a non-operating state, and moves with the relative movement between the vehicle body and the axle 10.
It is desirable that the winding of the wire 30 be freely released. With this configuration, during normal traveling, even if the bending of the parent-child spring 16 becomes small following the unevenness of the road surface,
Since the winding of the wire 30 is freely released, it is possible to reliably prevent the ride comfort from being deteriorated and the wire 30 from being damaged.

Further, as shown in FIG. 4, of the motor 28 and the wire 30 constituting the moving means, at least a casing 32 in which the wire 30 is housed may be provided. The casing 32 is made of a lightweight member such as soft resin rubber, and has a substantially cylindrical shape cylindrical portion 32A fitted to the outer periphery of the main body 28A of the motor 28, and a substantially truncated square tube whose cross-sectional area gradually decreases toward the tip. And a rectangular tube portion 32B having a shape. Wires 3 are provided on the surfaces of the cylindrical portion 32A and the rectangular tubular portion 32B facing the vehicle body (not shown).
A slit 32C for accommodating 0 in the internal space of the rectangular tube portion 32B is formed. Then, when the casing 32 is attached, the wire 30 is housed in the internal space of the rectangular tube portion 32B through the slit 32C, and then the cylindrical portion 32A.
May be fitted to the outer periphery of the main body 28A of the motor 28, and fixed here via a fastening member 34 such as a band. The method and shape of attaching the casing are not limited to the configuration of this embodiment, and any structure may be used as long as it is a structure that covers the wire.

In this way, even if the wire 30 is loosened due to the bending of the parent-child spring 16, for example, the wire 30 will not be entangled with the on-vehicle equipment, and the damage to the vehicle can be prevented. Needless to say, the present invention is applicable not only to the truck shown in this embodiment but also to other vehicles. In a vehicle having a monocoque body, the tip of the motor 28 or the wire 30 may be fixed to the body reinforced as necessary.

[0019]

As described above, according to the first aspect of the invention, the vehicle does not tilt during the cargo handling work,
It is possible to improve vehicle stability during cargo handling work. In addition, even in the case where cargo handling work is performed using a platform in a physical distribution warehouse or the like, the vehicle is not tilted so that the vehicle can be used easily and the workability can be improved. Furthermore, since the vehicle height can be adjusted, for example, the height of the luggage 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.

According to the second aspect of the invention, the moving means can be easily realized by diverting the existing motor and wire. According to the third aspect of the present invention, it is possible to reliably prevent a reduction in riding comfort and damage to the ropes during normal traveling. According to the invention described in claim 4, even if the rope is loosened due to the bending of the parent-child spring, it is possible to reliably prevent the vehicle from being damaged.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a parent-child spring type suspension device for a truck to which the present invention is applied.

[Figure 2] Characteristic diagram of parent-child spring

FIG. 3 is a schematic diagram illustrating a preload state.

4A and 4B show a casing, FIG. 4A is an explanatory view of a mounted state, FIG. 4B is a front view, and FIG.

[Explanation of symbols]

10 Axle 16 Parent-child spring 16A main spring 16B auxiliary spring 18 side members 20 spring bracket 24 spring bracket 26 Helper bracket 26A contact sheet 28 motors 30 wires 32 casing

Claims (4)

[Claims] 1. A parent-child spring composed of a main spring and an auxiliary spring vertically arranged with an intermediate portion fixed to an axle, a spring bracket for connecting both ends of the main spring to a vehicle body, and the vehicle body. When fixed and the deflection of the main spring exceeds a specified value, the helper bracket integrally formed with contact sheets that contact the upper surfaces of both ends of the auxiliary spring and the vehicle body are moved in the axle direction against the repulsive force of the parent-child spring. And a moving means for moving the parent-child spring type suspension device. 2. The moving means includes a winding device fixed to one of a vehicle body and an axle, and a cord wound around the winding device, and a tip end portion of the cord is a vehicle body. Alternatively, the parent-child spring type suspension device according to claim 1, wherein the suspension device is fixed to the other of the axles. 3. The parent-child spring type according to claim 2, wherein the winding device is configured to freely release the winding of the rope in association with the relative movement of the vehicle body and the axle when the winding device is not in operation. Suspension device. 4. The parent-child spring type suspension device according to claim 2, further comprising a casing in which the rope is housed.