A lawn mower tire tread pattern and tire that reduces hydroplaning in wetlands

Abstract

The utility model provides a kind of lawn mower tire tread pattern and tire for reducing wetland float slip, the outside side of pattern block IV is concave inward, forms concave fold line edge, can improve the corner of fold line edge to form multidirectional shearing stress when grounding, compared with the unidirectional friction of straight line edge, more effectively "bite" rough road surface, especially when accelerating / braking reduces skidding, the concave area of fold line edge forms micro guide groove when pattern block grounding, auxiliary main drain ditch quickly exports water film, reduces wetland "float slip" phenomenon.

Description

Technical Field

[0001] This utility model relates to a tire tread, and more particularly to a lawnmower tire tread pattern and tire that reduces slippage on wet surfaces. Background Technology

[0002] The lawnmower industry has shown rapid development in recent years, mainly driven by factors such as technological innovation, environmental protection policies, and changes in market demand. The rapid development of lawnmowers has saved lawnmower workers' working time, optimized the allocation of human resources, and made them increasingly popular with consumers and the market.

[0003] Existing technologies CN216153511U (Tire for Intelligent Lawn Mower and Intelligent Lawn Mower), CN202685791U (Comparative Document 2), and CN206357926U (Tread Pattern Structure of Pneumatic Tire for Agricultural Use) are still prone to slippage and floating, and the distribution of ground pressure and wear uniformity need further improvement.

[0004] Utility Model New Content

[0005] To address the aforementioned issues, this invention provides a lawnmower tire tread pattern and tire designed to reduce slippage on wet surfaces. The outer edge of tread block IV is recessed inward, forming a concave zigzag edge. This enhances the multi-directional shear stress generated at the edges of the zigzag edge upon contact with the ground. Compared to the unidirectional friction of straight edges, this is more effective at gripping rough surfaces, especially reducing slippage during acceleration / braking. The recessed area of ​​the zigzag edge forms a micro-channel when the tread block contacts the ground, assisting the main drainage ditch in quickly discharging water film and reducing slippage on wet surfaces.

[0006] The technical solution of this utility model is as follows: a lawnmower tire tread pattern that reduces slippage in wet conditions, comprising a first main tread block and a second main tread block, the first and second main tread blocks being symmetrical about the tread centerline and then staggered and not overlapping; the first and second main tread blocks are alternately arranged along the circumference of the tire; the first and second main tread blocks extend from the tire shoulder to the tire crown, and the first and second main tread blocks are collectively referred to as main tread blocks; each main tread block includes tread block IV, tread block I, tread block II, and tread block III connected in sequence, with tread block IV and tread block I directly connected at their ends, and tread block IV and tread block I located respectively at the tread centerline. On both sides, tread blocks I and II are connected by tread groove I, and tread blocks II and III are connected by tread groove II. Tread groove I is a zigzag groove. In the lateral direction of the tread, the outer edges of tread blocks IV and I are recessed inward to form recessed zigzag edges. A first secondary tread block is set between the first primary tread blocks that are circumferentially adjacent, and a second secondary tread block is set between the second primary tread blocks that are circumferentially adjacent. The first and second secondary tread blocks are symmetrical about the center line of the tread and then staggered. The first and second secondary tread blocks are collectively referred to as secondary tread blocks. The distance between the secondary tread blocks and the center line of the tread is greater than the maximum size of tread block IV in the lateral direction of the tread.

[0007] The perpendicular distance from the outer end point of tread block IV to the center line of the tread is greater than the perpendicular distance from the outer end point of tread block I to the center line of the tread; the front edge I of tread block I is parallel to the rear edge I of tread block I, the front edge II of tread block IV is parallel to the rear edge II of tread block IV, and the angle α between the front edge I of tread block I and the center line of the tread is less than the angle c between the rear edge II of tread block IV and the center line of the tread.

[0008] The angle α between the front edge I of tread block I and the center line of the tread is 30-60°. The zigzag edge on the outer side of tread block I includes the front edge I and the rear edge I. The angle b between the front edge I and the center line of the tread is 5-30°. The angle c between the rear edge II of tread block IV and the center line of the tread is 35-65°. The zigzag edge on the outer side of tread block IV includes the front edge II and the rear edge II. The angle d between the rear edge II and the center line of the tread is 5-30°.

[0009] The edges of tread blocks I and IV are straight lines; the front edge I and rear edge I of tread block I are curved at the connection with tread groove I; the front edge IV and rear edge IV of tread groove II are curved lines; the front edge III of tread block III is a straight line, the rear edge III is curved at the connection with tread groove II, and the rest of the rear edge of tread block III is a straight line; the front edge V and rear edge V of tread block II are curved lines; the front edge VI of the secondary tread block is a straight line 18-20mm from the horizontal position of the tire shoulder, the rear edge VI of the secondary tread block is a straight line 16-18mm from the horizontal position of the tire shoulder, and the rest of the VI and rear edge VI of the secondary tread block are curved lines.

[0010] The angle a2 between the front edge V wall of patterned block II and the upper normal direction of the wall is greater than the angle a3 between the rear edge V wall and the upper normal direction of the wall; the radius R2 of the arc of the front edge V of patterned block II is less than the radius R3 of the arc of the rear edge V of patterned block II; the vertical distance between the two arcs of the front edge V and the rear edge V of patterned block II is the same, ranging from 28 to 32 mm.

[0011] The angle α1 between the front edge I and rear edge I of patterned block I and the normal direction at the top of the wall is the same, which is 7°–9°. The angle α1 between the front edge II and rear edge II of patterned block IV and the normal direction at the top of the wall is the same, which is 7°–9°.

[0012] The angle a3 between the rear edge V wall of patterned block II and the normal direction of the upper part of the wall is 7°–9°, and the angle a2 between the front edge V wall of patterned block II and the normal direction of the upper part of the wall is 9°–11°.

[0013] The angle α4 between the front edge Ⅲ and the rear edge Ⅲ of the patterned block Ⅲ and the upper normal direction of the wall surface is 9-11°.

[0014] The angle f between the rear edge III of the tread block III and the center line of the tread is 55-85°.

[0015] The angle g between the secondary tread block at shoulder line b-b1 and the center line of the tread is 100-127°.

[0016] The secondary pattern block is an independent pattern block with a thickness d1 of 2.5-3.5mm and a width B1 of 4-6mm. In the width direction, the bottom of the secondary pattern block adopts an arc transition with an angle R5 of 0.8-1.2mm.

[0017] The depth h1 of the patterned groove I is 9-11 mm, and the width B2 is 9-11 mm; the angle between the groove wall of the patterned groove I and the normal direction of the upper end of the groove wall is 4-6°; the groove wall of the patterned groove I and the bottom of the groove are transitioned with a rounded corner with a radius R3 of 2.5-3.5 mm; the angle a6 between the groove wall of the patterned groove I and the normal direction of the upper end of the groove wall is 4-6°.

[0018] Tread groove II is a straight groove, and the angle e between the groove wall of tread groove II and the center line of the tread is 15-45°. In the transverse direction of the tread, the groove wall of tread groove II slopes outward from the front end to the rear end. The depth h2 of tread groove II is 4-6mm, and the width B3 is 18-22mm. The angle between tread groove II and the horizontal direction is 45-75°. The angle a7 between the groove wall of tread groove II and the normal direction at the upper end of the groove wall is 4-6°. The groove wall and the bottom of tread groove II are transitioned with a rounded corner with a radius R7 of 2.5-3.5mm.

[0019] The thickness d of patterned blocks I, II, III, and IV is the same, and the thickness ranges from 14 to 16 mm.

[0020] The bottom of the front edge I and the rear edge I of pattern block I are rounded, and the radius R1 of the rounded transition can be 4-6mm.

[0021] The front edge V and the bottom of the rear edge V of pattern block II are rounded, and the radius R1 of the rounded transition can be 4-6mm.

[0022] The bottom of the front edge III and the rear edge III of the patterned block III are rounded with a radius R4 of 4-6mm.

[0023] The front edge II and the bottom of the rear edge II of the patterned block IV are rounded, and the radius R1 of the rounded transition can be 4-6mm.

[0024] The tire shoulder is an open shoulder. Tread block III extends towards the tire shoulder to form a shoulder tread block. The shoulder tread block has a symmetrical V-shaped design that is narrow inside and wide outside. The angles between the front edge VII and the rear edge VII of the shoulder tread block and the horizontal line are 9-11° respectively. The narrowest width of the shoulder tread block is 28-32mm at the connection between the shoulder tread block and tread block III.

[0025] Vent holes are provided on the secondary patterned blocks.

[0026] A tire with the tread pattern described above.

[0027] The beneficial effects of this utility model are as follows: This utility model provides a lawnmower tire tread pattern and tire that reduces slippage on wet surfaces. The main tread blocks, through the alternating design of each tread block and each tread groove, disperse the ground pressure and reduce uneven tread wear. The outer edge of tread block IV is concave inward, forming a concave zigzag edge. The advantages of this concave zigzag edge are: the edges of the zigzag edge generate multi-directional shear stress when grounding, which is more effective in "gripping" the rough road surface compared to the unidirectional friction of a straight edge, especially reducing slippage during acceleration / braking. The concave area of ​​the zigzag edge forms a micro-drainage channel when the tread block grounds, assisting the main drainage ditch in quickly discharging water film and reducing the "slippage" phenomenon on wet surfaces.

[0028] The zigzag groove I provides edge engagement, allowing its edges to embed into soft surfaces such as grass, mud, and gravel, increasing friction. Furthermore, the zigzag groove disrupts laminar flow, creating localized turbulence within the groove. This more efficiently ejects water and controls drainage direction compared to straight grooves, directing water diagonally towards the tire sidewall and preventing water accumulation in the center of the tread that could lead to lateral slippage. The sudden change in centrifugal force at the corners of the zigzag groove makes it easier to eject any stuck gravel, mud, or weeds, reducing groove blockage. In addition, the turning points of the zigzag groove disperse ground impact, reducing the risk of cracks at the groove root.

[0029] The core purpose of this application, through the distances of tread blocks I and IV from the tread centerline and the asymmetrical horizontal distance design of tread blocks I and IV, is to optimize the tire's contact pressure distribution, handling stability, and wear uniformity through differentiated layout. Tread block I has a smaller horizontal distance from the tread centerline at its outer end, shortening the lever arm and reducing longitudinal twisting of the tread block during acceleration / braking, thus improving response speed. Tread block IV has a larger horizontal distance from the tread centerline at its outer end, increasing the contact patch area at the tread center and improving lateral grip during cornering.

[0030] The asymmetrical design of patterned blocks I and IV in this application results in an asymmetrical drainage channel design, which increases the drainage volume by 9.8% per unit time and shortens the braking distance in wetlands. Attached Figure Description

[0031] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0032] Figure 2 This is a schematic diagram of the planar unfolded structure of this utility model; the structure between the two green horizontal solid lines in the middle of the figure is half of a single intercept.

[0033] Figure 3 yes Figure 1 AA ， Cross-sectional view;

[0034] Figure 4 yes Figure 1 Zhong BB ， Cross-sectional view;

[0035] Figure 5 yes Figure 1 China CC ， Cross-sectional view;

[0036] Figure 6 yes Figure 1 Medium EE ， Cross-sectional view;

[0037] Figure 7 yes Figure 1 FF ， Cross-sectional view;

[0038] Figure 8 yes Figure 1 Chinese GG ， Cross-sectional view;

[0039] Figure 9 yes Figure 1 HH ， Cross-sectional view;

[0040] Reference numerals: Main tread block 1, Secondary tread block 2, Front edge VI 21, Rear edge VI 22, Exhaust hole 23, Tread block I 3, Front edge I 31, Rear edge I 32, Front edge I 33, Rear edge I 34, Tread block II 4, Front edge V 41, Rear edge V 42, Tread block III 5, Front edge III 51, Rear edge III 52, Tread block IV 6, Front edge II 61, Rear edge II 62, Front edge II 63, Rear edge II 64, Tread groove I 7, Tread groove II 8, Front edge IV 81, Rear edge IV 82, Shoulder tread block 9, Front edge VII 91, Rear edge VII 92. Detailed Implementation

[0041] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. It should be understood that the preferred embodiments described herein are only for illustration and explanation of this utility model and should not be construed as limiting the scope of protection of this utility model. Those skilled in the art can make some non-essential improvements and adjustments based on the content of this utility model below. In this utility model, unless otherwise expressly specified and limited, the technical terms used in this application should have the ordinary meaning understood by those skilled in the art.

[0042] Figure 2 In the center, the top is front, the bottom is back, the furthest from the center line of the tire tread is outside, and the closest to the center line of the tire tread is inside.

[0043] like Figures 1-9As shown, a lawnmower tire tread pattern includes a first main tread block 1 and a second main tread block. The first main tread block 1 and the second main tread block are symmetrical about the tread centerline and then staggered, and do not overlap. The first main tread block and the second main tread block are alternately arranged along the circumference of the tire. The first main tread block and the second main tread block extend from the tire shoulder to the tire crown. The first main tread block and the second main tread block are collectively referred to as main tread block 1. Each main tread block 1 includes tread blocks IV6, I3, II4, and III5 connected in sequence. The ends of tread blocks IV6 and I3 are directly connected. Tread blocks IV6 and I3 are located on both sides of the tread centerline, and the included angles formed between tread blocks IV6, I3 and the tread centerline are acute angles. The included angle between block IV6 and tread block I3 is less than 180°. Tread blocks I3 and II4 are connected by tread groove I7, and tread blocks II4 and III5 are connected by tread groove II8. Tread groove I7 is a zigzag groove. In the lateral direction of the tread, the outer edges of tread blocks IV6 and I3 are recessed inward to form recessed zigzag edges. A first secondary tread block is set between the first primary tread blocks 1 that are circumferentially adjacent, and a second secondary tread block is set between the second primary tread blocks that are circumferentially adjacent. The first and second secondary tread blocks are symmetrical about the center line of the tread and then staggered. The first and second secondary tread blocks are collectively referred to as secondary tread blocks 2. The distance between secondary tread blocks 2 and the center line of the tread is greater than the maximum size of tread block IV in the lateral direction of the tread.

[0044] The main tread blocks distribute ground pressure through the alternating design of each block and groove, reducing uneven tread wear. The segmented tread block design improves steering response speed.

[0045] The outer edge of tread block IV is concave, forming a recessed zigzag edge. The advantages of this design are: the sharp edges of the zigzag edge generate multi-directional shear stress upon contact with the ground, which is more effective at gripping rough surfaces compared to the unidirectional friction of straight edges, especially reducing slippage during acceleration / braking. On dry surfaces, the zigzag edge design can reduce longitudinal slippage by 5-8%. Furthermore, the recessed zigzag edge allows the tire to contact the ground in segments when rolling on grass or wet surfaces, preventing sudden changes in grip caused by the entire tread block detaching simultaneously, thus improving handling stability. The recessed area of ​​the zigzag edge forms micro-channels when the tread block contacts the ground, assisting the main drainage channels in quickly draining water film and reducing "floating slip" on wet surfaces.

[0046] The angles formed between tread blocks IV and I and the tire centerline are both acute angles. The advantage of an angle less than 180° between tread blocks IV and I is that it provides the tire with traction in the forward direction. Additionally, because the angles between tread blocks IV and I and the tire centerline are acute, the longitudinally arranged tread blocks generate lateral shear resistance when the vehicle turns. Through the mechanical interlocking of the tread block edges with the ground, cornering stability is improved. Because the angles between tread blocks IV and I and the tire centerline are acute, diagonal tread blocks are formed. Tread blocks II4 and III5 are also diagonal tread blocks. These diagonal tread blocks distribute contact pressure more evenly during cornering, preventing premature slippage in the tire shoulder area, especially optimizing the handling response of front-wheel-drive vehicles. The angles formed between tread block IV, tread block I and the center line of the tread are acute angles. Therefore, through the longitudinally arranged tread blocks, the "herringbone" grooves formed between adjacent longitudinally arranged tread blocks IV and I can guide water flow to the sidewall at a specific angle, avoiding the drainage blind spots of traditional longitudinal grooves and reducing the risk of water drift when driving through puddles at high speed.

[0047] One side of groove I is the concave zigzag edge of tread block I, and the other side of groove I is parallel to this side, thus groove I is a zigzag groove. The gap formed by groove I7 promotes airflow and reduces tread heat generation, while also providing edge engagement. The edge of groove I can embed into soft road surfaces such as grass, mud, and gravel, increasing friction. In addition, the bend of the zigzag groove disrupts the laminar flow of water, generating local turbulence within the groove. This is more efficient than straight grooves in dislodging water and controlling the drainage direction, causing water to flow obliquely towards the tire sidewall, preventing water from accumulating in the center of the tread and causing lateral slippage. The sudden change in centrifugal force at the corner of the zigzag groove makes it easier to dislodge stuck gravel, mud, or weeds, reducing groove blockage. Furthermore, the turning point of the zigzag groove can disperse the impact force of ground contact, reducing the risk of cracks at the groove root.

[0048] The angle α between the front edge I31 of tread block I3 and the center line of the tread is 30-60°. The zigzag edge on the outer side of tread block I includes the front edge I33 and the rear edge I34. The angle b between the front edge I and the center line of the tread is 5-30°. The angle c between the rear edge II62 of tread block IV6 and the center line of the tread is 35-65°. The zigzag edge on the outer side of tread block IV includes the front edge II63 and the rear edge II64. The angle d between the rear edge II64 and the center line of the tread is 5-30°.

[0049] The angle α between the front edge I31 of tread block I and the center line of the tread is 30-60°. The advantage of this setting is that it strengthens directional traction. The acute angle of 30-60° generates oblique shear force when the tire rolls, converting part of the longitudinal force into lateral biting force and preventing slippage during acceleration / braking.

[0050] The angle b between the front I33 and the center line of the tread is 5-30°. This small angle of 5-30° allows the broken edge of the outer side of the tread block I3—the front I33 and the rear I34—to contact the ground in segments, reducing impact noise.

[0051] The rear edge of tread block IV6 forms an angle c of 35-65° with the center line of the tread, forming an asymmetrical herringbone shape with tread block I3, guiding water flow obliquely out and avoiding water accumulation in the center.

[0052] In addition, when d≤30°, the broken edge can bounce off small stones, reducing groove damage between the rear end edge II62 of patterned block IV and the front end edge of patterned groove I7.

[0053] The front edge I31 of tread block I3 is parallel to the rear edge I32 of tread block I3, and the front edge II61 of tread block IV6 is parallel to the rear edge II62 of tread block IV6. Moreover, the angle α between the front edge I31 of tread block I3 and the center line of the tread is smaller than the angle c between the rear edge II62 of tread block IV6 and the center line of the tread.

[0054] Preferably, the angle α between the front edge I31 of tread block I3 and the center line of the tread is 45°, the angle between the rear edge I32 of tread block I3 and the center line of the tread is 45°, the angle between the front edge II61 of tread block IV6 and the center line of the tread is 50°, and the angle c between the rear edge II62 of tread block IV6 and the center line of the tread is 50°.

[0055] The perpendicular distance from the outer end of tread block IV6 to the center line of the tread is greater than that from the outer end of tread block I3. The perpendicular distance from the outer end of tread block IV6 to the center line of the tread is 34-37 mm, while the perpendicular distance from the outer end of tread block I3 to the center line of the tread is 24-28 mm.

[0056] The two outer endpoints of tread block IV6 are equidistant from the perpendicular line to the center line of the tread, and the two outer endpoints of tread block I3 are equidistant from the perpendicular line to the center line of the tread.

[0057] The asymmetrical horizontal distance design of tread blocks I and IV from the tread centerline, as defined in this application, aims to optimize tire contact pressure distribution, handling stability, and wear uniformity through differentiated layout. Tread block I has a smaller horizontal distance from the tread centerline at its outer end, shortening the lever arm and reducing longitudinal twisting of the tread block during acceleration / braking, thus improving response speed. Tread block IV has a larger horizontal distance from the tread centerline at its outer end, increasing the contact patch area at the tread center and improving lateral grip during cornering.

[0058] The asymmetrical design of patterned blocks I and IV in this application results in an asymmetrical drainage channel design, which increases the drainage volume by 9.8% per unit time and shortens the braking distance in wetlands.

[0059] Tread groove II 8 is a straight groove, and the angle e between the groove wall and the center line of the tread is 15-45°. In the lateral direction of the tread, the groove wall of tread groove II slopes outward from the front end to the rear end. The angle e is 15-45°. If the angle e < 15°, the angle is too small, resulting in low drainage efficiency; if the angle e > 45°, the angle is too large, which will weaken the longitudinal rigidity of the groove and affect handling. The outward slope of the groove wall of tread groove II can effectively guide water flow to the side of the tire and avoid water accumulation in the center of the tread, which can cause slippage. In addition, the outward slope of the groove wall helps to shake out mud, gravel, or weeds in the groove, preventing debris from clogging the drainage or affecting grip.

[0060] The angle f between the rear edge III52 of tread block III5 and the center line of the tread is 55-85°. The 55-85° inclined rear edge III52 can disperse the ground pressure, avoid stress concentration at the root of tread block III5, and delay the formation of cracks; the larger angle makes the rear edge III52 of tread block III5 deform less when subjected to lateral force (such as turning), improve the lateral support of the tread, reduce lateral deviation, and improve steering accuracy.

[0061] The rear edge III52 and the front edge III51 of the patterned block III5 are parallel.

[0062] The angle g between secondary tread block 2 at the shoulder line b-b1 and the center line of the tread is 100-127°. Try to make the secondary tread block 2 near the shoulder aligned with the direction of tread block Ⅲ5.

[0063] Patterned blocks I and IV have straight edges, therefore they are linear blocks. The front edge I and rear edge I of patterned block I3 have an arc transition where they connect to pattern groove I. The front edge IV81 and rear edge IV82 of pattern groove II8 are both arcs. The front edge III51 of patterned block III5 is a straight line, and the rear edge III52 has an arc transition where it connects to pattern groove II8. The rest of the rear edge of patterned block III5 is a straight line. The front edge V41 and rear edge V42 of patterned block II4 are both arcs.

[0064] The front edge VI21 ​​of the secondary tread block 2 is a straight line 18-20mm from the horizontal position of the tire shoulder, and the rear edge VI22 of the secondary tread block 2 is a straight line 16-18mm from the horizontal position of the tire shoulder. The rest of the VI21 ​​and the rear edge VI22 of the secondary tread block 2 are curved lines.

[0065] The hybrid straight and curved tread block design of tread block III5 and secondary tread block 2 achieves multi-objective optimization of tire performance through differentiated combinations of geometric shapes. Straight edges reduce tread deformation and energy loss. The front and rear edges of tread block III5 and secondary tread block 2 near the tire shoulder are both straight, extending from the shoulder towards the crown center, consistent with the tread's direction of travel, enhancing straight-line directional accuracy. The curved transition avoids stress concentration at the junction of the tread groove and the tread block, preventing crack formation.

[0066] The thickness d of tread blocks I, II, and IV is consistent, ranging from 14 to 16 mm. This consistent thickness ensures even heat distribution and slows down rubber aging. In addition, the thickness range designed in this application provides sufficient rigidity to support high loads while avoiding excessive thickness that could lead to overheating of the tread or increased weight.

[0067] The bottom of the front edge I31 and rear edge I32 of patterned block I is rounded, and the radius R1 of the rounded transition can be 4-6mm; the bottom of the front edge V41 and rear edge V42 of patterned block II is rounded, and the radius R1 of the rounded transition can be 4-6mm; the bottom of the front edge II61 and rear edge II62 of patterned block IV is rounded, and the radius R1 of the rounded transition can be 4-6mm. The rounded corners avoid stress concentration at the root of the patterned block and reduce the risk of cracking.

[0068] The angle α1 between the front and rear edge walls of tread blocks I3 and IV6 and the normal direction at the upper end of the wall surface is the same, and can be 7°–9°. Tread blocks I3 and IV6 are located at the center of the tread and are responsible for direct drive / braking. The inclined wall surface allows the tread blocks to gradually contact the ground as they roll, reducing impact vibration and improving comfort. At the same time, the slight inclination creates a guide, helping to expel small stones, mud, or grass.

[0069] The angle 'a2' between the front edge V41 wall and the upper normal direction of the wall surface of pattern block II 4 is greater than the angle 'a3' between the rear edge V42 wall and the upper normal direction of the wall surface. The angle 'a3' between the rear edge V42 wall and the upper normal direction of the wall surface of pattern block II 4 is 7°–9°, while the angle 'a2' between the front edge V41 wall and the upper normal direction of the wall surface of pattern block II 4 is 9°–11°. The larger angle between the front edge V41 wall and the upper normal direction of the wall surface of pattern block II 4 accelerates the water flow from the front end into the adjacent pattern groove, reducing water film residue, which is particularly effective for wet and slippery surfaces such as lawnmowers. The smaller angle between the rear edge V42 wall and the upper normal direction of the wall surface of pattern block II 4 maintains the rigidity of the rear end, ensuring efficient force transmission during drive / braking.

[0070] The radius of curvature R2 of the front edge V41 of tread block II is smaller than the radius of curvature R3 of the rear edge V42 of tread block II. The smaller radius of curvature of the front edge V41 creates a steeper guide surface, quickly cutting off the water film between the tread and the road surface, and preferentially guiding the water flow into tread groove I and tread groove II, reducing the risk of slipping on wet roads. The larger radius of curvature of the rear edge V42 creates a smooth transition, guiding the water flow to diffuse gently into tread groove II, avoiding the water flow separation effect caused by a sudden widening of the drainage path. The radius of curvature of the front edge V41 can be 190-210mm, and the radius of curvature of the rear edge V42 can be 220-240mm, so that the curvature of tread block II transitions between tread groove I and tread groove II.

[0071] The vertical distance between the two arcs on the front edge V41 and the rear edge V42 of the patterned block II is the same, and can be in the range of 28-32mm. The vertical spacing ensures that a sufficient cross-sectional area is formed between the two arcs, and the spacing provides an unobstructed discharge path for the mud and sand particles.

[0072] The depth h1 of tread groove I is 9-11mm, and the width B2 is 9-11mm. The angle between the groove wall and the upper normal direction of the groove wall is 4-6°. The groove wall and the bottom are transitioned with a rounded corner with a radius R3 of 2.5-3.5mm. The width of tread groove I ensures sufficient support between the tread blocks, preventing the grooves from closing under pressure when the tire is cornering. Compared to the thickness of adjacent tread blocks I and II, the depth of tread groove I is reduced, creating a drop that effectively removes impurities such as grass, mud, and sand, improving the tire's self-cleaning ability. The effect is even better when a 5mm drop is formed.

[0073] The angle α6 between the wall of the patterned groove I and the normal direction at the top of the groove wall is 4-6°. The slight inclination guides the water flow towards the side of the tire and reduces turbulence in the groove. In particular, the drainage efficiency is 12% higher than that of a vertical groove wall at a 5° inclination angle.

[0074] The trench wall and trench bottom are transitioned with a rounded corner with a radius of R6 of 2.5-3.5mm, which can effectively reduce the peak stress at the trench bottom, prevent the expansion of cracks at the trench bottom after long-term use, and reduce the generation of eddies during drainage, thus reducing pump suction noise.

[0075] The depth h2 of the tread groove II is 4-6mm, the width B3 is 18-22mm, the angle with the horizontal direction is 45-75°, the angle a7 between the groove wall and the normal direction of the upper end of the groove wall is 4-6°, and the groove wall and the bottom of the groove are transitioned with a rounded corner with a radius R7 of 2.5-3.5mm. When the tire rolls, it can quickly expel water from the road surface, prevent the formation of a water film between the tire and the grass, and prevent slippage.

[0076] The depth-to-width ratio of the tread groove II in this application balances high-speed drainage and contact patch. The extra-wide grooves form a high-speed drainage channel, and with a 45-75° tilt angle, water flow can be quickly guided to the tire sidewall. Actual measurements show that a 20mm wide groove increases drainage speed by 40% compared to a 10mm wide groove, making it especially suitable for muddy or rainy road conditions. The 4-6mm shallow depth ensures that the grooves are not easily squeezed and closed during high-speed cornering.

[0077] The outer end of tread block Ⅲ5 is circumferentially located at the shoulder line b-b1 (EE). ， (Directional) sectional view, i.e. Figure 6 The bottom of the front edge III51 and rear edge III52 of tread block III features a rounded corner with a radius R4 of 4-6mm. The angle α4 between the wall of the front edge III51 and rear edge III52 of tread block III5 and the upper normal direction of the wall is 9-11°. The thickness d of tread block III5 is 14-16mm. The rounded corner with a radius of 4-6mm at the bottom ensures that the shoulder area bears the maximum lateral force during cornering, resulting in uniform stress distribution and reducing the risk of root cracks. In particular, the 5mm rounded corner further evens out stress distribution, reducing the risk of root cracks by 60%. In addition, the rounded corner with a radius of 4-6mm at the bottom promotes the filling of the mold dead corners by the rubber material during vulcanization, reducing air bubbles and defects in the tread corners.

[0078] The angle between the front edge Ⅲ51 and the rear edge Ⅲ52 of the tread block Ⅲ5 and the normal direction of the upper part of the wall is 9-11°. The 9-11° inclination angle allows the tread block to gradually contact the ground during rolling, reducing impact noise and avoiding vibration caused by the tire shoulder "slapping the road surface".

[0079] Pattern block III has the same thickness as pattern blocks I, II, and IV, ensuring even heat distribution, delaying rubber aging, providing sufficient rigidity to support high loads, and avoiding excessive thickness that could lead to overheating of the tread or increased weight.

[0080] The tire shoulder is an open shoulder, and the shoulder grooves can more efficiently drain water or muddy grassy surfaces from the open shoulder, reducing the risk of hydroplaning and enhancing wet grip.

[0081] Tread block III5 extends towards the shoulder to form shoulder tread block 9. Shoulder tread block 9 has a symmetrical V-shaped design, narrow on the inside and wide on the outside. This design gives shoulder tread block 9 an "outward-expanding structure," which significantly improves the lateral rigidity of the shoulder area. The shoulder is the part of the tire most susceptible to compression. The outward-expanding angle disperses stress, prevents tearing at the root of the main tread block, and allows the shoulder tread block to gradually contact the ground during rolling, avoiding localized concentrated wear.

[0082] The angles between the front edge VII91 and the rear edge VII92 of the shoulder tread block 9 and the horizontal line are 9-11° respectively. The connection between the shoulder tread block 9 and the tread block Ⅲ5 is the narrowest width of the shoulder tread block 9, which is 28-32mm. This can effectively reduce the rigid compression of the shoulder tread block 9 when cornering, avoid sudden changes in grip due to excessive deformation of the tread block Ⅲ5, and allow the tire to transmit force more evenly when turning, thus improving the control precision of the lawnmower.

[0083] The secondary pattern block is an independent pattern block, with a thickness d1 of 2.5-3.5 mm and a width B1 of 4-6 mm. The secondary pattern block is shown in a cross-sectional view along its width direction (FF direction). Figure 7 The bottom uses an arc transition with an angle of 0.8-1.2mm radius R5. The bottom of the front and rear edges of the secondary pattern block uses a rounded corner transition with a radius of 0.8-1.2mm. The angle a5 between the front and rear edge walls of the secondary pattern block and the upper normal direction of the wall is 4-6°, which can reduce the risk of pattern rounded corners.

[0084] The secondary pattern block 2 is provided with an exhaust hole 23 to improve exhaust performance and reduce defects in the rounded corners of the secondary pattern block. The diameter of the exhaust hole can be φ1.8mm.

[0085] This invention provides a tread pattern for lawnmower tires that can improve the formation of multi-directional shear stress at the edges of the zigzag edges when they touch the ground. Compared with the unidirectional friction of straight edges, this is more effective at "gripping" rough surfaces, especially reducing slippage during acceleration / braking. The concave areas of the zigzag edges form micro-channels when the tread blocks touch the ground, which help the main drainage ditch quickly discharge water film and reduce the "floating slip" phenomenon in wetlands.

[0086] The above descriptions are merely preferred embodiments of this utility model, not all embodiments. The scope of protection of this utility model is not limited thereto. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model. It should be noted that for those skilled in the art and any person skilled in the art, any equivalent substitutions or changes made based on the technical solutions and utility model concept of this utility model, as well as any changes and improvements made without departing from the overall concept and spirit of this utility model, should also be considered within the scope of protection of this utility model.

Claims

1. A lawnmower tire tread pattern that reduces slippage on wetlands, characterized in that: It includes a first main tread block (1) and a second main tread block. The first main tread block (1) and the second main tread block are symmetrical about the center line of the tread and are staggered and do not overlap. The first main tread block and the second main tread block are alternately arranged along the circumference of the tire. The first main tread block and the second main tread block extend from the tire shoulder to the tire crown. The first main tread block and the second main tread block are collectively referred to as main tread block (1). Each main tread block (1) includes tread block IV (6), tread block I (3), tread block II (4), and tread block III (5) connected in sequence. The ends of tread block IV (6) and tread block I (3) are directly connected. Tread block IV (6) and tread block I (3) are located on both sides of the center line of the tread, respectively. Pattern blocks II (4) are connected by pattern groove I (7), and pattern blocks II (4) and pattern blocks III (5) are connected by pattern groove II (8). In the lateral direction of the tread, the outer edges of pattern blocks IV (6) and pattern blocks I (3) are recessed inward to form recessed folded edges. A first secondary pattern block is set between the first primary pattern blocks (1) that are adjacent in the circumferential direction, and a second secondary pattern block is set between the second primary pattern blocks that are adjacent in the circumferential direction. The first secondary pattern block and the second secondary pattern block are symmetrical about the center line of the tread and then staggered. The first secondary pattern block and the second secondary pattern block are collectively referred to as secondary pattern blocks (2). The distance between the secondary pattern block (2) and the center line of the tread is greater than the maximum size of pattern block IV in the lateral direction of the tread.

2. The lawnmower tire tread pattern for reducing wetland slippage according to claim 1, characterized in that: Pattern groove I (7) is a zigzag groove; the perpendicular distance from the outer end of pattern block IV (6) to the center line of the tread is greater than the perpendicular distance from the outer end of pattern block I (3) to the center line of the tread; the front edge I (31) of pattern block I (3) is set parallel to the rear edge I (32) of pattern block I (3), the front edge II (61) of pattern block IV (6) is set parallel to the rear edge II (62) of pattern block IV (6), and the angle a between the front edge I (31) of pattern block I (3) and the center line of the tread is smaller than the angle c between the rear edge II (62) of pattern block IV (6) and the center line of the tread.

3. The lawnmower tire tread pattern for reducing wetland slippage according to claim 2, characterized in that: The angle a between the front edge I (31) of tread block I (3) and the center line of the tread is 30-60°. The broken edge of the outer side of tread block I includes the front edge I (33) and the rear edge I (34). The angle b between the front edge I and the center line of the tread is 5-30°. The angle c between the rear edge II (62) of tread block IV (6) and the center line of the tread is 35-65°. The broken edge of the outer side of tread block IV includes the front edge II (63) and the rear edge II (64). The angle d between the rear edge II (64) and the center line of the tread is 5-30°.

4. The lawnmower tire tread pattern for reducing wetland slippage according to claim 1, characterized in that: The edges of tread blocks I and IV are straight lines; the front edge I and rear edge I of tread block I (3) are connected to the tread groove I with an arc transition; the front edge IV (81) and rear edge IV (82) of tread groove II (8) are arcs; the front edge III (51) of tread block III (5) is a straight line; the rear edge III (52) of tread block III (5) is connected to the tread groove II (8) with an arc transition; the remaining part of the rear edge of tread block III (5) is a straight line; the front edge V (41) and rear edge V (42) of tread block II (4) are arcs; the front edge VI (21) of secondary tread block (2) is a straight line 18-20mm away from the horizontal position of the tire shoulder; the rear edge VI (22) of secondary tread block (2) is a straight line 16-18mm away from the horizontal position of the tire shoulder; the remaining part of VI (21) and rear edge VI (22) of secondary tread block (2) is an arc.

5. The lawnmower tire tread pattern for reducing wetland slippage according to claim 1, characterized in that: The angle a2 between the front edge V (41) wall and the upper normal direction of the wall is greater than the angle a3 between the rear edge V (42) wall and the upper normal direction of the wall; the radius R2 of the arc of the front edge V (41) of patterned block II is less than the radius R3 of the arc of the rear edge V (42) of patterned block II; the vertical distance between the two arcs of the front edge V (41) and the rear edge V (42) of patterned block II is the same, ranging from 28 to 32 mm.

6. The lawnmower tire tread pattern for reducing wetland slippage according to claim 5, characterized in that: The angle a1 between the front edge I (31) and the rear edge I (32) of the patterned block I (3) and the normal direction at the top of the wall is the same, which is 7°-9°. The angle a1 between the front edge II (61) and the rear edge II (62) of the patterned block IV (6) and the normal direction at the top of the wall is the same, which is 7°-9°. The angle a3 between the rear edge V (42) wall of patterned block II (4) and the normal direction of the upper part of the wall is 7°-9°; the angle a2 between the front edge V (41) wall of patterned block II (4) and the normal direction of the upper part of the wall is 9°-11°. The angle a4 between the front edge III (51) and the rear edge III (52) of the patterned block III (5) and the normal direction at the upper end of the wall is 9-11°.

7. The lawnmower tire tread pattern for reducing wetland slippage according to claim 1, characterized in that: The angle f between the rear edge Ⅲ (52) of the tread block Ⅲ (5) and the center line of the tread is 55-85°; The angle g between the secondary tread block (2) at the shoulder line b-b1 and the center line of the tread is 100-127°; The secondary pattern block is an independent pattern block with a thickness d1 of 2.5-3.5mm and a width B1 of 4-6mm. In the width direction, the bottom of the secondary pattern block adopts an arc transition with an angle R5 of 0.8-1.2mm.

8. The lawnmower tire tread pattern for reducing wetland slippage according to claim 1, characterized in that: The depth h1 of the patterned groove I is 9-11 mm, and the width B2 is 9-11 mm; the angle between the groove wall of the patterned groove I and the normal direction of the upper end of the groove wall is 4-6°; the groove wall of the patterned groove I and the bottom of the groove are transitioned with a rounded corner with a radius R3 of 2.5-3.5 mm; the angle a6 between the groove wall of the patterned groove I and the normal direction of the upper end of the groove wall is 4-6°. Tread groove II (8) is a straight groove, and the angle e between the groove wall of tread groove II (8) and the center line of the tread is 15-45°; in the transverse direction of the tread, from the front end to the rear end of the groove wall of tread groove II, the groove wall of tread groove II slopes outward; the depth h2 of tread groove II is 4-6mm, and the width B3 is 18-22mm; the angle between tread groove II and the horizontal direction is 45-75°; the angle a7 between the groove wall of tread groove II and the normal direction of the upper end of the groove wall is 4-6°; the groove wall of tread groove II and the bottom of the groove are transitioned with a rounded corner with a radius R7 of 2.5-3.5mm; The thickness d of patterned block I, patterned block II, patterned block III (5), and patterned block IV is the same, and the thickness range is 14-16mm; The bottom of the front edge I (31) and rear edge I (32) of the pattern block I is rounded, and the radius R1 of the rounded transition can be 4-6mm. The bottom of the front edge V (41) and rear edge V (42) of the pattern block II is rounded, and the radius R1 of the rounded transition can be 4-6mm. The bottom of the front edge III (51) and the rear edge III (52) of the patterned block III (5) adopts a rounded corner with a radius R4 of 4-6mm; The bottom of the front edge II (61) and rear edge II (62) of the patterned block IV is rounded, and the radius R1 of the rounded transition can be 4-6mm.

9. The lawnmower tire tread pattern for reducing wetland slippage according to claim 1, characterized in that: The tire shoulder is an open tire shoulder. Tread block III (5) extends to the tire shoulder to form tire shoulder tread block (9). The tire shoulder tread block (9) is a figure-eight symmetrical design with a narrow inner side and a wide outer side. The angle between the front edge VII (91) and the rear edge VII (92) of the tire shoulder tread block (9) and the horizontal line is 9-11° respectively. The narrowest width of the tire shoulder tread block (9) is 28-32mm at the connection between the tire shoulder tread block (9) and tread block III (5). The secondary patterned block (2) is provided with an exhaust hole (23).

10. A tire, characterized in that: The tire tread pattern is the tread pattern described in any one of claims 1-9.

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