JP2016117296A - Solid tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid tire high in durability, traction performance and brake performance even when a hole opened on a side face is present.SOLUTION: A solid tire 1 has a plurality of holes 26 opened in its rotational axis direction and a ground plane 22 on an outer periphery. The solid tire includes an annular base rubber layer 11 having a rim fitting surface 21 fitted in the rim R of an industrial vehicle and positioned in the inner side of a diameter direction, and a cap rubber layer 12 which is an annular layer joined to the outer periphery 25 of the base rubber layer to cover it. The base rubber layer includes 20 mass% or more to 50 mass% or less of short fibers, and a distance Hb from the rim fitting surface to its outer periphery is 35% or more to 50% or less of a distance H from the rim fitting surface to the ground plane. In the holes, an average distance Ha from the rim fitting surface is 30% or less of the distance H from the rim fitting surface to the ground plane.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a solid tire used for industrial vehicles such as forklifts and crane trucks.

For example, in a forklift, since the occurrence of puncture is directly linked to an accident, solid tires (non-pneumatic tires) formed of solid rubber are used instead of pneumatic tires used in passenger cars and the like.
Solid tires made of solid rubber have a smaller volume change (deformation) due to compression than rubber, and therefore absorb less vibration than a pneumatic tire. Therefore, by providing a plurality of holes that open in the side surface (sidewall) of the solid tire and have a depth in the width direction (rotational axis direction), the solid rubber can be easily deformed to improve vibration absorption, and at the same time A technique has been proposed in which the inner surface functions as a heat radiating surface to promote heat radiation of a tire that generates heat during traveling (for example, Patent Document 1).

JP 2012-035815 A

In general, when a solid tire having a hole opened in a side surface and having a depth in the width direction is mounted on a forklift or the like or is braked, a large shearing force is applied to a portion near the rim in the hole. When this shearing force is repeatedly applied, cracks may occur inside the holes of the solid tire, which may reduce the durability of the solid tire.
In addition, solid tires with such holes are prone to circumferential distortion (inside / outside in the radial direction across the holes) during acceleration and braking, which deteriorates traction performance and braking performance. There's a problem.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a solid tire having good durability, traction performance, and braking performance despite having a hole opened in a side surface.

The solid tire according to the present invention has a plurality of holes that open in the direction of the rotation axis, and has a ground contact surface on the outer periphery. A solid tire is an annular base rubber layer that has a rim fitting surface that is fitted to a rim of an industrial vehicle and is positioned on the radially inner side, and an annular layer that is joined to and covers the outer periphery of the base rubber layer. A certain cap rubber layer.
The base rubber layer includes 20% by mass to 50% by mass of short fibers, and the distance Hb from the rim fitting surface to the outer periphery thereof is 35% to 50% of the distance H from the rim fitting surface to the grounding surface. It is.

In the holes, the average distance Ha from the rim fitting surface is 30% or more of the distance H (referred to as “height H”) from the rim fitting surface to the grounding surface.
The ground contact surface is partitioned in the circumferential direction by a lateral groove extending from the inner side in the width direction of the solid tire to the outer end in the width direction.
The average depth D of the holes is 10% or more and 90% or less of half W of the width of the solid tire at the position where the holes are provided in the radial direction, and all of the holes open on one side in the width direction of the solid tire. The total cross-sectional area Aa of each of the holes passes through a circle passing through a position 30% away from the rim fitting surface in the radial direction about the center of rotation and a widthwise outer end of the lateral groove. It is 20% or more and 50% or less of the area Ac of the annular range sandwiched between the circles.

In another solid tire, the ground contact surface is further partitioned in the circumferential direction by a lateral groove extending from the inner side in the width direction to the outer end in the width direction of the solid tire. The average depth D of the holes is 10% or more and 90% or less of half W of the width of the solid tire at the position where the holes are provided in the radial direction, and all of the holes open on one side in the width direction of the solid tire. The total cross-sectional area Aa of each of the holes passes through a circle passing through a position 30% away from the rim fitting surface in the radial direction about the center of rotation and a widthwise outer end of the lateral groove. It is 20% or more and 50% or less of the area Ac of the annular range sandwiched between the circles.

In the solid tire, the joining position of the base rubber layer and the cap rubber layer overlaps the hole in the radial direction.
The hole may be formed so that the cross-sectional area gradually increases from the deepest part in the depth direction or from the middle toward the opening.
A plurality of holes having the same size and shape may be arranged at equal intervals in the circumferential direction on one side in the width direction.

  The plurality of holes on one side in the width direction may be composed of a plurality of types having different opening shapes, opening sizes, and depths.

  ADVANTAGE OF THE INVENTION According to this invention, the vibration at the time of driving | running | working is suppressed and the solid tire which has favorable durability, traction performance, and brake performance can be provided.

FIG. 1 is a side view of a solid tire. FIG. 2 is a development view of the tread surface. 3 is a cross-sectional view taken along arrow AA in FIG. FIG. 4 is a diagram for explaining how to determine the position of the rim fitting surface when the rim fitting surface is curved or the like. FIG. 5 is a side view of another solid tire. FIG. 6 is a side view of another solid tire. FIG. 7 is a side view of another solid tire. 8 is a cross-sectional view taken along arrow BB in FIG. FIG. 9 is a cross-sectional view of another solid tire. It is a figure which shows the outline | summary of the solid tire which is a comparative example.

1 is a side view of the solid tire 1, FIG. 2 is a development view of a tread surface, and FIG. 3 is a cross-sectional view taken along line AA in FIG. The side view of the solid tire 1 is a view of the solid tire 1 as viewed from the direction of the rotation axis. A rotation axis means a rotation axis when the solid tire 1 is mounted on an industrial vehicle.
The solid tire 1 includes a base rubber layer 11, a cap rubber layer 12, a side rubber layer 13, and a core material 14.

  The base rubber layer 11 is an inwardly annular layer in the solid tire 1 and is a portion held by the rim R in the solid tire 1 mounted on an industrial vehicle. The base rubber layer 11 is held on the rim R by a rim fitting surface which is an inner peripheral surface of the base rubber layer 11. For the base rubber layer 11, a rubber having a high hardness, for example, a rubber having a hardness of 85, is used to support the weight of the industrial vehicle. The hardness of the rubber used for the base rubber layer 11 is preferably 80 to 95.

The hardness of rubber is a measured value (durometer hardness) by a durometer based on “JIS K 6253”.
The rubber forming the base rubber layer 11 contains 20 to 50% by mass of short fibers. As the short fibers, organic fibers such as nylon, vinylon, polyester, and rayon having a length of 1 to 300 mm, or inorganic fibers such as steel fibers and glass fibers are used.

A plurality of core members 14 that circulate in the circumferential direction are embedded in the base rubber layer 11. The core material 14 is formed by twisting one steel cord or a plurality of steel cords.
The cap rubber layer 12 is an annular layer that is bonded to and covers the outer periphery of the base rubber layer 11. The rubber used for the cap rubber layer 12 is lower in hardness than the rubber used for the base rubber layer 11 and has a hardness of 60, for example. The hardness of the rubber of the cap rubber layer 12 is preferably 60 to 75.

  On the outer peripheral surface of the cap rubber layer 12, pattern blocks 15,..., 15 whose end surfaces are grounding surfaces 22 are formed. The pattern blocks 15,..., 15 are arranged at equal intervals in the circumferential direction on the both sides in the width direction, and the inclined grooves 23 that make a rounded line while alternately changing the inclination direction in the width direction of the solid tire 1. It is demarcated by the extended lateral grooves 24, 24 and is arranged in a staggered pattern in the width direction. The “width direction” here refers to the direction of the rotation axis of the solid tire 1.

The side rubber layer 13 is a rubber layer that covers the side surfaces of the base rubber layer 11 and the cap rubber layer 12 on both sides in the width direction. The rubber used for the side rubber layer 13 has a hardness of 50-80.
In the solid tire 1, the base rubber layer 11 has a specific height (diameter thickness) Hb. That is, in the solid tire 1, the rim fitting surface 21 to the base rubber layer 11 in the base rubber layer 11 with respect to the height (diameter thickness) H from the rim fitting surface 21 to the ground contact surface 22 of the solid tire 1. The ratio of the height Hb to the outer peripheral surface 25 is 35 to 50% (0.35 ≦ Hb / H ≦ 0.5). The rim fitting surface 21 refers to an inner peripheral surface of the solid tire 1 that is fitted to a rim when mounted on an industrial vehicle.

The base rubber layer 11 in the solid tire 1 is formed of rubber having a design height (thickness, Hb / H) and a high hardness as compared with the conventional solid tire, and further, 20-50 mass% of short fibers. Since it is included, it contributes to the rigidity improvement of the solid tire 1 whole.
By the way, the position of the rim fitting surface 21 serving as a reference for the heights H and Hb is the straight line if the rim fitting surface 21 is a straight line parallel to the rotating shaft in a cross section including the rotating shaft (for example, FIG. 3). The position of is adopted.

When the cross section including the rotation axis of the rim fitting surface 21 has a straight line other than a straight line parallel to the rotation axis, the position of the rim fitting surface 21 serving as a reference for the heights H and Hb is determined as follows. Is done.
FIG. 4 is a diagram for explaining how to determine the position of the rim fitting surface 21 when the cross section of the rim fitting surface 21 has a plurality of straight lines.
Of the straight lines in the cross section of the rim fitting surface 21, a straight line (referred to as “first reference line BL1”) located on the outermost side in the width direction is extended outward in the width direction. Separately, a straight line closest to the rotation axis and perpendicular to the rotation axis is extracted from the outer edge in the width direction in the cross section including the rotation axis of the base rubber layer 11, and this straight line is extended (extended) The straight line is referred to as “second reference line BL2”). Then, an intersection of the first reference line BL1 and the second reference line BL2 is set as a reference point BP.

The height H of the solid tire 1 and the thickness Hb of the base rubber layer 11 are obtained by adopting the reference point BP as the starting point (one end of the dimension) in the radially inward direction. Hereinafter, the reference point BP is used as a reference for the distance from the rim fitting surface 21 in the radial direction for each portion of the solid tire 1.
As the position of the ground contact surface 22 for obtaining the height H of the solid tire 1, a portion farthest from the rotation axis (of the ground contact surface 22) is employed. The position of the ground contact surface 22 employed for determining the height H in the solid tire 1 is on a plane that bisects the solid tire 1 in the width direction. Hereinafter, the plane that bisects is referred to as “tire equatorial plane EQ”.

The solid tire 1 is provided with a plurality of holes 26 that are respectively opened on the side surfaces on both sides in the width direction. The hole 26 is a cylindrical space having a bottom and an axis center parallel to the rotation axis. One hole 26 is provided in one pattern block 15.
In the hole 26, the distance Ha from the rim fitting surface 21 to the deepest portion in the radial direction is 30% or more of the height H of the solid tire 1 (0.3 ≦ Ha / H). The height H of the solid tire 1 is the maximum value of the distance from the rim fitting surface 21 (reference point BP) to the ground contact surface 22 in the radial direction.

In the case of the hole 26D in which the shape of the cross section changes depending on the depth of the hole (see FIG. 3B), the radial distance Ha between the deepest portion of the hole 26D and the rim fitting surface 21 is 0.3 ≦ Ha / H, and the radial distance Hc between the opening of the hole 26D and the rim fitting surface 21 is 15% or more of the height H of the solid tire 1 (0.15 ≦ Hc / H). When the cross-sectional shape of the hole 26D changes depending on the depth of the hole, the distance Ha of the deepest portion is always equal to or greater than the distance Hc at the opening (Ha ≧
Hc).

The upper limit of the distance Ha is naturally limited by the radially outer end in the cross-sectional shape of the hole 26 and the depth of the lateral groove 24 in the entire range in the width direction.
The range of the distance Ha from the rim fitting surface 21 on the inner peripheral surface of the hole 26 (0.3 × H ≦ Ha) and the range of the height Hb to the outer peripheral surface 25 of the base rubber layer 11 (0.35 × H ≦ Hb ≦ 0.5 × H) partially overlap (range of 0.35 × H). For this reason, in the solid tire 1, the hole 26 is provided to overlap the boundary between the base rubber layer 11 and the cap rubber layer 12 in the radial direction.

  The depth D of the hole 26 is 10 to 90% (0.1 × W ≦ D ≦ 0.9 × W) of the distance W from the opening to the tire equatorial plane EQ, preferably 60 to 80%. It is. When the entire edge of the opening portion of the hole 26 is not in a plane parallel to the tire equator plane EQ and / or when the deepest portion of the hole 26 is not a plane parallel to the tire equator plane EQ, the depth D and the distance W are Average depth and average distance are employed.

  The average depth D and the average distance W are calculated by replacing the range that can be regarded as the bottom in the deepest portion of the hole 26 and the entire edge of the opening portion with a plane parallel to the tire equatorial plane EQ that can approximate them. “A plane parallel to the tire equator plane EQ that can be approximated” means, for example, a three-dimensional space formed by intersecting a plane parallel to the tire equator plane EQ with the entire edge of the opening portion and the edge of the opening portion and this plane. Is a plane whose volume is equal on both sides of this plane.

  The total area Aa on one side of the cross-sections of the holes 26,..., 26 on both side surfaces of the solid tire 1 is from a position 30% away from the rim fitting surface 21 radially outward from the height H of the ground contact surface 22. Specific to the area of the annular range centering on the rotation axis up to the end 27 on the side surface side of the solid tire 1 at the bottom of the lateral groove 24 (hereinafter referred to as the “contrast area Ac”, see the shaded ring in FIG. 1) It is designed to be a ratio. The specific ratio means that the total area Aa on one side of the cross section of the holes 26,..., 26 is 20 to 50% (0.2 ≦ Aa / Ac ≦ 0.5) with respect to the contrast area Ac. The value of Aa ÷ Ac is preferably 24 to 30%. The comparison area Ac is obtained without considering the unevenness of the side surface of the solid tire 1 and assuming the corresponding range as a plane in a side view (for example, determined by the side view of FIG. 1).

  When the area of the cross section of the hole varies depending on the depth of the hole (for example, FIGS. 8 and 9), the cross sectional area of one hole added as “total area on one side of the cross section” is the depth of the cross section perpendicular to the rotation axis. The average in direction is used. Therefore, the area where the cross section perpendicular to the rotation axis is not closed and the area is not determined in the vicinity of the opening is not added to the cross sectional area. The average area of the cross section of one hole 26 is a value obtained by dividing the volume of the hole in a range where the cross section in the depth direction becomes a closed loop by the depth at which the cross section of the hole becomes a closed loop (volume / depth).

In the solid tire 1, the distance Ha from the rim fitting surface 21 of the hole 26 is 30% or more of the height H of the solid tire 1 (0.3 ≦ Ha / H). In the solid tire 1, the radial thickness Hb of the base rubber layer 11 containing 20 to 50% of short fibers is 35 to 50% with respect to the height H from the rim fitting surface 21 to the ground contact surface 22. It is formed.
Since the solid tire 1 is formed in this manner, circumferential distortion generated inside and outside the hole 26 in the radial direction is alleviated, and deterioration of traction performance and brake performance is suppressed. The reduction of the strain in the circumferential direction inside and outside the hole 26 prevents the occurrence of cracks inside the hole 26 and improves the durability of the solid tire 1.

In the solid tire 1, the hole 26 has a predetermined cross-sectional size (0.2 ≦ Aa / Ac ≦ 0.5) and depth (0.1 × W ≦ D ≦ 0.9 × W). Therefore, it is excellent in vibration relaxation and heat dissipation.
5 and 6 are side views of other solid tires 1B and 1C.
The solid tire 1B has two types of holes 26Ba and 26Bb having different opening areas.

The solid tire 1C has three types of holes 26Ca, 26Cb, and 26Cc having different opening areas. Since the solid tire 1B and the solid tire 1C are the same as the solid tire 1 except for the holes, the description thereof is omitted, and the same reference numerals as those in the solid tire 1 are given in FIGS.
As with the hole 26, the two types of holes 26Ba and 26Bb in the solid tire 1B are cylindrical spaces each having a bottom and whose axis is parallel to the rotation axis. Either one of holes 26Ba and 26Bb is provided on the radially inner side surface with respect to one pattern block 15, and two kinds of holes 26Ba and 26Bb are alternately arranged in the circumferential direction.

  Each of the three types of holes 26Ca, 26Cb, 26Cc in the solid tire 1C is a cylindrical space having a bottom and an axis that is parallel to the rotation axis. On the radially inner side surface of one pattern block 15, one hole 26Ca having a large opening area, three holes 26Cb having a smaller opening area, and two holes having a smaller opening area than the hole Cb are provided. 26Cc is provided as a set. The hole 26Ca having the largest opening is arranged radially inward, and one of the holes 26Cb having the next largest opening is arranged radially inward of the hole 26Ca. The remaining two holes 26Ca are arranged between the holes 26Ca and 26Cb arranged in the radial direction between them in the radial direction. The two holes 26Cc are arranged on the radially outer side of the hole 26Cb on both sides of the hole 26Ca and the hole 26Cb. The three types of holes 26Ca, 26Cb, and 26Cc are plane-symmetric with respect to a plane that simultaneously includes the centers of the holes 26Ca and the holes 26Cb aligned in the radial direction and the rotation axis.

  The holes 26Ba, 26Bb and the holes 26Ca, 26Cb, 26Cc are all the same as the hole 26 of the solid tire 1, and the distance Ha from the deepest rim fitting surface 21 is 30% or more of the height H of the solid tire 1. It is. The holes 26Ba, 26Bb and the holes 26Ca, 26Cb, 26Cc all have a depth of 10 to 90% of the distance from the opening to the tire equatorial plane EQ.

  In the solid tires 1B and 1C, the total area of the cross-sections of the holes on both side surfaces is 20 to 50% with respect to the comparison area Ac. This ratio is more preferably 24 to 30%. The “contrast area” is the outer side in the radial direction than the position 30% away from the rim fitting surface 21 and the height H of the ground contact surface 22, and from the end 27 on the side surface side of the solid tire 1 at the bottom of the lateral groove 24. Is also the area of the annular portion in the radial direction, in a side view.

By combining a plurality of types of holes with different sizes of openings, the rigidity (degree of deflection) during travel of the solid tires 1B and 1C can be adjusted more appropriately than when a single type of hole is provided. .
The depths of the holes 26Ba, 26Bb, 26Ca, 26Cb, and 26Cc in the solid tires 1B and 1C may be varied and / or the cross-sectional shapes may be varied.

7 is a side view of another solid tire 1D, and FIG. 8 is a cross-sectional view taken along line BB in FIG.
Since the solid tire 1D is the same as the solid tire 1 except for the shape and the like of the hole 26D, the description thereof is omitted, and the same reference numerals as those in the solid tire 1 are given in FIGS.

  The hole 26 </ b> D of the solid tire 1 </ b> D has a substantially trapezoidal shape in which a cross-section perpendicular to the rotation axis is positioned with a short bottom side radially inward and a long bottom side radially outward. In the hole 26D, an inner surface that is a long bottom in a cross section extends from the opening to the deepest portion in parallel to the rotation axis. The hole 26D becomes higher as the height of the trapezoidal cross section approaches the opening. That is, the other short base on the radially inner side in the cross section gradually approaches the rotation axis as the opening is approached, and the cross-sectional area increases, and the inner surface (substantially flat) corresponding to the bottom surface is Tilt. One hole 26 </ b> D opens radially inward with respect to one pattern block 15 on both sides in the width direction.

In the hole 26D of the solid tire 1D, the relationship between the distance W from the opening to the tire equatorial plane EQ and the depth D thereof, and the relationship between the total area of the cross section of the hole 26D on both sides in the width direction and the “contrast area” These relationships are the same in the solid tires 1, 1B, 1C.
In the solid tire 1D, the relationship between the deepest distance Ha from the rim fitting surface 21 of the hole 26D and the height H of the solid tire 1D and the relationship between the opening distance Hc and the height H are as follows: These relationships are the same in 1, 1B, 1C.

FIG. 9 is a cross-sectional view of another solid tire 1E on a plane including the rotation axis. The side view of the solid tire 1E is the same as that of the solid tire 1D (see FIG. 7). Solid tire 1
E is the same as that of the solid tire 1 except for the shape of the hole 26E.
The hole 26E of the solid tire 1E has substantially the same trapezoidal shape as the hole 26D of the solid tire 1D, and the short base is located radially inward. The hole 26E of the solid tire 1E is a trapezoidal column whose cross-sectional shape continues to be the bottom from the deepest bottom toward the opening (outward). The hole 26E is inclined inward from the middle toward the opening so that the inner surface on the radially inner side approaches the opening as it approaches the opening. The cross-sectional area of the hole 26E increases with the inclination of the inner surface on the radially inward side as it approaches the opening. The distance Da from the starting position of the inward inclination of the inner surface on the radially inner side to the opening of the hole 26E is 15% or more of the depth D of the hole 26E. The case where the distance Da is 100% is the hole 26D shown in FIGS.

In the hole 26E of the solid tire 1E, the relationship between the distance W from the opening to the tire equatorial plane EQ and the depth D thereof, and the relationship between the total area of the cross section of the hole 26E on both sides in the width direction and the “contrast area” These relationships are the same in the solid tires 1, 1B, 1C.
The relationship between the distance Ha from the rim fitting surface 21 at the deepest portion of the hole 26E in the solid tire 1E and the height H of the solid tire 1E is the same as these relationships in the solid tires 1, 1B, 1C.

  The cross-sectional shapes of the holes 26D and 26E in the solid tires 1D and 1E are trapezoidal, but these cross-sectional shapes may be rectangular. The solid tires 1D and 1E may have a plurality of types of holes having different sizes, depths, shapes, and the like.

  Table 1 shows the above-described solid tires 1, 1B, 1C, and 1E (Examples 1 to 4 in order), a solid tire having no holes (Comparative Example 1), and a solid tire having holes different from those of Examples 1 to 4. This is a result of running test with 7 etc. mounted on an industrial vehicle. FIG. 10 shows an outline of the solid tire 7 used in Comparative Example 2. 10A is a side view, and FIG. 10B is a cross-sectional view taken along the line CC of FIG.

Conditions common to the running tests of the solid tires 1, 1 </ b> B, 1 </ b> C, 1 </ b> E, 7 of Examples 1 to 4 and Comparative Examples 1 and 2 are as follows.
[Structure of solid tire]
Tire size: 21X8-9
Short fiber content: 35%
Base rubber layer rubber hardness: 85 degrees Cap rubber layer rubber hardness: 65 degrees Side rubber layer rubber hardness: 60 degrees Hb ÷ H: 0.4
Ha / H: 0.35
Total area Aa / contrast area Ac of cross section of hole on one side in width direction: 0.42
D ÷ W (hole depth ÷ distance from opening to tire equator): 0.7
[Running test]
It was mounted on a 2.5-ton counterbalance forklift and was actually run. The “opening damage” was evaluated by visual evaluation after a load of 1.5 tons and traveling 2000 km. Ride comfort and traction + brake performance were indexed by the driver's experience on the road surface under the same conditions. The visual observation of the degree of damage to the opening and the sensation such as riding comfort were all performed by a plurality of persons, and for each index, the five-level evaluation results of each person with 5 being the best and 0 being the worst were averaged.
[Evaluation]
The indexed opening damage, ride comfort and traction + brake performance are summed up, and the numerical value (index total) is 10 or more, solid tire with good durability, traction performance and brake performance, 9 to less than 10 These were judged to be acceptable solid tires.

If the short fiber contained in the base rubber layer 11 exceeds 50%, the relative rubber content decreases, resulting in a large distortion during running and easy breakage.
When the height ratio (Hb ÷ H) of the base rubber layer 11 exceeds 0.5, the tread rubber layer 11 is peeled off at the end of wear.
In the above-described embodiment, the solid tires 1, 1 </ b> B to 1 </ b> E can have no side rubber layer 13. The cross-sectional shape and the opening shape of the holes 26, 26Ba, 26Bb, 26Ca, 26Cb, 26Cc, 26D, and 26E in the solid tires 1, 1B to 1E can be changed to other shapes. For example, an ellipse or an ellipse may be adopted instead of the cross-section of the holes 26, 26Ba, 26Bb, 26Ca, 26Cb, and 26Cc and the circle of the opening shape. Further, the cross-sectional shape of the deep part of the holes 26D and 26E may be a rectangle or a square.

  In addition, each structure of the solid tires 1 and 1B to 1E and the solid tires 1 and 1B to 1E, or the entire structure, shape, dimensions, number, material, and the like can be appropriately changed in accordance with the spirit of the present invention.

  The present invention can be used for solid tires used in industrial vehicles such as forklifts and crane cars.

1,1B-1E Solid tire 11 Base rubber layer 12 Cap rubber layer 21 Rim fitting surface 22 Grounding surface 24 Lateral groove 25 (Outside of base rubber layer) Outer surface (outside of base rubber layer)
26, 26Ba, 26Bb, 26Ca, 26Cb, 26Cc, 26D, 26E Hole R Rim

Claims (6)

A solid tire having a plurality of holes that open in the rotational axis direction and having a contact surface on the outer periphery,
An annular base rubber layer having a rim fitting surface fitted to a rim of an industrial vehicle and located on the radially inner side;
A cap rubber layer that is an annular layer that is bonded to and covers the outer periphery of the base rubber layer;
The base rubber layer is
Containing 20 mass% or more and 50 mass% or less of short fibers,
And the distance Hb from the rim fitting surface to the outer periphery is 35% or more and 50% or less of the distance H from the rim fitting surface to the ground contact surface,
The hole is
A solid tire, wherein an average distance Ha from the rim fitting surface is 30% or more of a distance H from the rim fitting surface to the ground contact surface. The ground contact surface is partitioned in the circumferential direction by a lateral groove extending from the inner side in the width direction of the solid tire to the outer end in the width direction,
The hole is
The average depth D is 10% or more and 90% or less of half W of the width of the solid tire at the position where the hole is provided in the radial direction,
In addition, the total cross sectional area Aa of all the holes opened on one side in the width direction of the solid tire is 30% of the distance H from the rim fitting surface in the radial direction, all centered on the rotation center. 2. The solid tire according to claim 1, which is 20% or more and 50% or less of an area Ac of an annular range sandwiched between a circle passing through a position and a circle passing through the outer end in the width direction in the lateral groove. The solid tire according to claim 1, wherein a joining position between the base rubber layer and the cap rubber layer overlaps the hole in the radial direction. The solid tire according to any one of claims 1 to 3, wherein the hole has a cross-sectional area that gradually increases from the deepest part in the depth direction or from the middle toward the opening. The solid tire according to any one of claims 1 to 4, wherein a plurality of holes having the same size and shape are arranged at equal intervals in the circumferential direction on one side in the width direction. The solid tire according to any one of claims 1 to 5, wherein the plurality of holes on one side in the width direction are formed of a plurality of types having different shapes, sizes, and depths of the openings.