JPH063681Y2 - Solid tires for steering of heavy goods vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention This invention is a solid tire for a heavy-duty carrier, which has an elastic layer made of polyurethane that has excellent compression resistance, but has small flexibility and is difficult to deform, In particular, the present invention relates to a faithful tire for steering that changes its direction by steering operation.

2. Description of the Related Art For example, in a vehicle such as a forklift truck for carrying an ultra-heavy material such as a large metal ingot for rolling, a solid tire is often used as a tire capable of withstanding a high load. Solid rubber tires are generally known as solid tires, but these solid rubber tires have appropriate flexibility and are excellent in shock absorption and transmission of driving force and braking force to the road surface. However, in addition to low heat resistance, the rubber is a poor heat conductor, so there is a risk of frictional heat with the road surface accumulating, causing overheating and damage, and low wear resistance.

Therefore, as one of the solid tires to replace the solid rubber tire, a solid tire using polyurethane having excellent heat resistance and abrasion resistance as an elastic material while having excellent compression resistance has come to be used in recent years. It was

FIG. 3 shows an example in which a solid tire for a heavy goods carrier made of polyurethane which has already been used is used as a steering tire. The steering tire 1 is an outer periphery of a cylindrical metal rim 1a. In addition, the elastic layer 1b made of polyurethane is formed to have a constant thickness by a fixing means such as baking, and the V groove 1c is provided in the center so as to form two solid tires.

A cylindrical cast iron rotatably mounted on a spindle 4 rotatably connected in a horizontal direction by a king pin 3 to an end portion of a steering wheel axle 2 of a heavy goods carrier via bearings 5 and 5. The steering tire 1 is fitted around the outer periphery of the hub 6 so as to rotate integrally with the hub 6 and to rotate horizontally around the king pin 3 as a fulcrum so as to be steerable.

For example, as shown in Fig. 4, the diameter is 300 mm and the width is 24 mm.
When the 0 mm steering tire 1 is installed so that the distance from the inside of the tire to the axis of the kingpin 3 is 25 mm, steering is stopped at 30 ° C (installation at 30 ° C). When the cutting is performed, the moving distance inside the tire, that is, the length l of the arc drawn by the ground contact point inside the tire is In contrast, the moving distance outside the tire, that is, the length L of the arc drawn by the ground contact point outside the tire is The moving distance l inside the tire is about 1/10 of the moving distance L outside the tire, and the moving distance l inside and outside the tire is
And the moving distance L greatly differ. Therefore, when stationary steering is performed, a large twisting force is generated in the elastic layer 1b of the steering tire 1 that changes direction due to frictional resistance with the road surface. In particular, a heavy-duty carrier such as a forklift carries a heavy object of 10 tons or more, and therefore the above-mentioned twisting force becomes extremely large.

When steering is performed while the vehicle is running, the steering tire 1 rotates around the spindle 4 and moves forward while turning horizontally around the kingpin 3 as a fulcrum to change its direction. Since the forward distance is added to the moving distance on the outside of the tire and the moving distance on the outside of the tire, the ratio does not become as large as the ratio 1 / L in the case of the stationary steering, but the outer diameter of the steering tire 1 is both inside and outside the vehicle body. Since they are the same, a large twisting force still acts on the elastic layer 1b of the steering tire 1 when changing the direction by steering.

Problems to be solved by the invention By the way, polyurethane has excellent compression resistance,
It is particularly inferior in flexibility to rubber. Regarding the steering tire 1 using such a polyurethane as the elastic layer, a large twisting force is generated in the portion on the vehicle body center side (inner side of the tire) during steering as described above, and if this twisting force is repeated, elasticity is increased. Since the polyurethane layer is poor in flexibility, cracks C may occur in the elastic layer on the inner side of the tire, and the cracks may progress to cause partial peeling of the polyurethane from the outer periphery of the rim 1a.

The present invention has been made in view of the above circumstances, and as a solid tire for a steering of a heavy goods vehicle using polyurethane, which is particularly poor in flexibility, as an elastic layer, the twisting force applied to the elastic layer during steering is reduced. The purpose of the present invention is to provide a tire having improved durability.

Means for Solving the Problems As a means for solving the above problems, the present invention is
In a solid tire for steering of a heavy goods vehicle, in which an elastic layer made of polyurethane is formed on the outer periphery of a cylindrical rim, from the vehicle body center side when the hub is attached to the position of 1/4 to 1/2 of the tire width The outer peripheral surface of the elastic layer in the range is formed in a taper shape with a taper inclination of 2 to 10%, and the elastic layer outside the tapered body has a substantially uniform thickness. The outer diameter of the tire on the center side is smaller than the outer diameter of the tire on the outside of the vehicle body.

Operation As described above, the tire width should be
The elastic layer outer peripheral surface in the range of 1/4 to 1/2 position is formed in a taper shape with a taper inclination of 2 to 10%, and compared with the tire outer diameter on the outside of the vehicle body where the traveling distance becomes long during steering. hand,
Shorter travel distance during steering By reducing the tire outer diameter on the center side of the vehicle body, when steering while running (stationary steering)
At the vehicle body center side of the tire, that is, the load (ground load) received from the road surface on the tire inner side portion becomes smaller and the frictional force at that portion becomes smaller, so the twisting force generated in the elastic layer inside the tire during steering. The inner circumference of the tire is shorter than the outer circumference due to the taper on the inside of the tire in response to the fact that the moving distance inside the tire is shorter than that outside during steering during running. In both cases, the torsional force generated in the elastic layer of the steering tire during steering is reduced, thereby preventing the occurrence of cracks and extending the service life.

Here, in the elastic layer, a portion where the taper is not formed,
That is, the load from the road surface is larger in the portion where the thickness is substantially uniform on the outer side of the tire than in the tapered portion. And when the range where the taper is formed exceeds the position of 1/2 from the vehicle body center side, the ground contact area of a portion having a substantially uniform thickness that receives a large ground load becomes small as described above,
The ground load per unit area at that portion locally becomes excessive, and conversely the durability deteriorates. On the other hand, when the range of the portion forming the taper is from the vehicle body center side to the position less than 1/4 of the tire width, the effect of reducing the twisting force during steering as described above cannot be sufficiently obtained. If the slope of the taper is less than 2%, the above effect cannot be obtained. On the other hand, if the slope of the taper exceeds 10%, the slope of the taper is too large to reliably contact the inner portion of the tire, and therefore the ground contact load per unit area is excessive. On the contrary, there is a possibility that durability may be reduced. Therefore, in order to reliably reduce the twisting force during steering and at the same time to prevent the ground load from locally becoming excessive and to improve the durability reliably, the range of the part where the taper is formed is set to the center of the vehicle body. 1/1 of the tire width from the side
Up to the position of 4 to 1/2 and the taper inclination is 2 to 10%
Must be within the range.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

The steering wheel 11 made of polyurethane is a low-floor heavy-duty vehicle 1 for carrying and transporting large metal ingots S for rolling.
No. 2 (see FIG. 2) is used as a steering tire. The steering tire 11 is formed by baking an elastic layer 5 made of polyurethane as an elastic material on the outer periphery of a cylindrical metal rim 11a. It is fixed and formed into a solid shape. Further, the steering tire 11 is rotatably connected in a horizontal direction by king pins 3 to both ends of two steering wheel axles 12a horizontally arranged at the front of the heavy goods carrier 12. Are mounted on the outer periphery of a cylindrical cast iron hub 6 that is rotatably attached to the mounted spindle 4 via bearings 5 and 5, and two are arranged on each side. When the steering wheel 13 is turned to and steered through the linkage 14 by the steering operation by the handle 13, the king pin 3 is turned to be a fulcrum to be turned.

The corner portions 11c and 11c 'on both sides of the ground surface of the elastic layer 15 made of polyurethane as described above have a radius of 10 to 10.
The outer peripheral surface of the elastic layer 15 having a roundness (R) of about 20 mm and within a range from the tire inner side to about 1/3 of the tire width is gradually reduced in diameter toward the tire inner side. The taper portion 11b is formed, and the inclination of the taper in the taper portion 11b is 3 to 5%.

If the steering tires 11 as described above are mounted on the spindles 4 of both the steering wheel axles 12a (one of which is not shown) of the heavy goods transport vehicle 12 so that the tapered portions 11b are on the vehicle body center side, respectively. The outer diameter of the tire inner portion of each steering tire 11 is smaller than the outer diameter of the tire outer portion, and the elastic layer 1 of each steering tire 11 is
The load applied to the inner tire portion of No. 5 is smaller than the load applied to the outer tire portion of the elastic layer 15. as a result,
When the steering operation is performed while the vehicle is stopped, the frictional force between the tire inner portion and the road surface becomes small, so that the twisting force generated in the tire inner portion during stationary steering is reduced.

Further, when the steering operation is performed during traveling, the taper portion 11b is provided inside the tire in the elastic layer 15 of the steering tire 11 to shorten the circumference of the tire inside portion, so that the circumference of the tire inside and the circumference of the outside are reduced. The steering tire 1 rotates about the kingpin 3 as a fulcrum while rotating around the spindle 4 during traveling steering.
The twisting force generated in the tire inner portion is reduced by approaching the ratio of the moving distance inside the tire to the moving distance outside the tire.

Further, in the case of the steering tire 11 of this embodiment, the corner portions 11 on both sides of the tire in the elastic layer 15 are provided.
Since c and 11c 'have R of about 10 to 20 mm,
The shock when the steering tire 11 rides on the unevenness of the road surface is effectively buffered, and the occurrence of cracks due to the shock when riding on the unevenness of the road surface is prevented.

In this embodiment, the inclination of the taper in the taper portion 11b is 3 to 5%, and the range of the portion forming the taper is from the vehicle body center side to the position of about 1/3, all of which are defined by the present invention. Therefore, the twisting force at the time of steering can be reliably reduced without causing an excessive ground load at a portion where the thickness on the outer side of the tire is substantially uniform.

Effects of the Invention As described above, the solid tire for steering of the heavy goods vehicle of the present invention has excellent compression resistance, but uses polyurethane having a small flexibility as the elastic layer. The outer peripheral surface in the range from the center side of the vehicle body at the time of hub attachment to 1/4 to 1/2 of the tire width,
Since the outer diameter of the tire on the center side of the vehicle body is made smaller than the outer diameter of the tire on the outer side of the vehicle body by forming the taper with a taper inclination of 2 to 10%, the road surface on the inner surface of the tire during steering while traveling is stopped. The frictional force generated between the tire and the vehicle can be reduced, and the difference in the outer diameter between the inside and outside of the tire approaches the difference in the moving distance between the inside and outside of the tire during steering during running, so steering is performed both when the vehicle is stopped and when it is running. It is possible to reduce the twisting force that acts on the inner side of the tire when the vehicle is diverted to prevent cracks from occurring and improve durability.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention. FIG. 1 is a sectional front view showing a solid steering tire attached to a hub, and FIG. 2 is a solid steering tire. 3 and 4 are side views of a heavy-duty carrier with an attached vehicle. FIG. 3 is a cross-sectional view showing a conventional solid tire for steering, and FIG. It is explanatory drawing which shows the tire which faces. 3 ... King pin, 4 ... Spindle, 6 ... Hub, 11 ... Steering tire, 11a ... Rim, 11b ... Tapered part, 11c, 11c '... Corner part, 12 ... Heavy goods carrier, 12a ... Steering wheel axle, 13 … Handle, 14…
Linkage, 15 ... Elastic layer, S ... Large metal casting soul for rolling.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B60C 5/00 H 8408-3D

Claims (1)

[Scope of utility model registration request] 1. A solid tire for a steering of a heavy goods vehicle, wherein an elastic layer made of polyurethane is formed on the outer circumference of a cylindrical rim, and 1/4 to 1/1 / the width of the tire from the vehicle body center side when a hub is attached. The outer peripheral surface of the elastic layer up to the position of 2 is formed in a taper shape with a taper inclination of 2 to 10%, and the elastic layer on the outer side of the vehicle body from the tapered portion is substantially uniform. A solid tire for a steering of a heavy goods vehicle, characterized in that the tire outer diameter on the vehicle body center side is smaller than the tire outer diameter on the vehicle body outer side.