JP6688203B2 - Stud pin and pneumatic tire with stud pin - Google Patents

Description

  The present invention relates to a stud pin and a pneumatic tire including the stud pin.

  Stud pins for pneumatic tires improve the running performance (including driving performance, braking performance, and turning performance) on the snow and snow road surface of a pneumatic tire or a vehicle equipped with it by scratching and piercing the snow and snow road surface. .

  The stud pin disclosed in Patent Document 1 includes a head or a body and a pin or a shaft protruding from an end surface of the body. One side of the shaft in plan view has a discontinuous contour in which at least one tooth is defined.

International Publication No. 2014/122570

  Since the shaft has edge components in multiple directions, traveling performance (particularly turning performance) on ice and snow road surfaces is further improved. However, in the conventional stud pins including those disclosed in Patent Document 1, sufficient consideration has not been given to giving the shaft a multi-directional edge component.

  An object of the present invention is to give a shaft of a stud pin an edge component in more directions.

  One aspect of the present invention includes a body and a shaft projecting from the body, the shaft having a first step part projecting from the body, a second step part projecting from the first step part, and It is a multi-stage structure including a plurality of step portions including at least a third step portion protruding from the second step portion, and the outer shape of the first step portion in plan view and the second step portion in plan view. Provide a stud pin having a different outer shape.

  The first step portion and the second step portion of the shaft have different outer shapes in a plan view. Therefore, the edge component of the first step portion and the edge component of the second step portion have different directions in a plan view. That is, the shaft has edge components in multiple directions, and these edge components act in multiple directions. As a result, the running performance on ice and snow roads is improved.

  It is preferable that the number of the edge components of the second step portion is smaller than the number of the edge components of the first step portion.

  The greater the number of edge components, the shorter the length of each edge component. By setting a relatively large number of edge components in the first step, it is possible to secure the length of each edge component and also secure the edge components in multiple directions. Also, by setting the number of edge components in the second step portion to be relatively small, the length of each edge component is ensured, and the edge component is ensured in a direction different from the edge component in the first step portion. it can.

  It is preferable that the number of edge components in the step portion of the most advanced stage is greater than the number of edge components in the second step portion from the most advanced stage.

  In general, the greater the number of edge components at a certain step, the higher the effect of the step to pierce the snow and snow road surface. In addition, the most advanced step has the highest piercing effect on the ice and snow road surface compared to other steps. Therefore, by setting the number of edge components of the step portion of the most advanced step relatively large, it is possible to effectively improve the piercing effect of the shaft on the icy and snowy road surface.

  When the total number of steps of the step portion of the shaft is an odd number, the number of the edge components of the odd-numbered N + 1-th step portion is set to be larger than the number of edge components of the N-th step portion. To be done.

  When the total number of steps of the step portion of the shaft is an even number, the number of the edge components of the even numbered step of the (N + 1) th step portion is set to be larger than the number of the edge components of the Nth step portion. To be done.

  According to the present invention, the shaft of the stud pin can be provided with the edge component in more directions, thereby improving the running performance on the snowy and snowy road surface.

The perspective view of the stud pin which concerns on 1st Embodiment of this invention. The top view of the shaft of the stud pin which concerns on 1st Embodiment. 1. The partial side view which looked at the stud pin which concerns on 1st Embodiment from the direction of the arrow III of FIG. The development view of the tread part of the pneumatic tire with which the stud pin concerning a 1st embodiment was attached. The top view of the shaft of the stud pin which concerns on 2nd Embodiment. The partial side view similar to FIG. 3 of the stud pin which concerns on 2nd Embodiment. The top view of the shaft of the stud pin which concerns on 3rd Embodiment. The partial side view similar to FIG. 3 of the stud pin which concerns on 3rd Embodiment. The top view of the shaft of the stud pin which concerns on 4th Embodiment. The partial side view similar to FIG. 3 of the stud pin which concerns on 4th Embodiment. The partial perspective view of the stud pin which concerns on a comparative example.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
Referring to FIGS. 1 to 3, the stud pin 1 according to the present embodiment generally has a shape extending along its own axis AX. In the following description, the term “plan view” may be used for the shape of the stud pin 1 viewed from the tip side along the axis AX.

  The stud pin 1 includes a base 2 closest to the base end, a shank 3 protruding from the base 2, and a body 4 provided at the tip of the shank 3. The stud pin 1 also includes a shaft 5 protruding from the body 4.

  In the hand of this embodiment, the base 2 has a substantially disk shape, and the body 4 has a substantially columnar shape. The shank 3 is generally a short cylinder having a smaller diameter than the base 2 and the body 4. The base 2, the shank 3, and the body 4 have an integral structure and are made of aluminum or an aluminum alloy. Other structures and materials can be adopted for the base 2, the shank 3, and the body 4.

  The body 4 includes an end surface 4a and a side surface 4b. In the present embodiment, the end surface 4a is a flat surface that extends substantially orthogonal to the axis AX. The end surface 4a may be inclined with respect to the axis AX or may be a non-flat surface. The shaft 5 projects from the end surface 4a of the body 4 in the direction along the axis AX. The contour or outer shape of the shaft 5 in plan view is within the region surrounded by the outer shape of the end surface 4 a of the body 4 in plan view. That is, the area of the outer shape of the shaft 5 in plan view is smaller than the area of the outer shape of the end surface 4a of the body 4 in plan view. For example, the former area can be set to 10 to 45% of the latter area.

  In the present embodiment, the material of the shaft 5 is tungsten. The shaft 5 is a separate component from the base 2, the shank 3, and the body 4, and is fixed to the body 4 by fitting. Other materials can be used for the shaft 5. The shaft 5 may be integrated with the body 4.

  Referring also to FIG. 4, the stud pin 1 is used by being mounted in the pin hole 6b formed in the tread portion 6a of the pneumatic tire 6. The entire base 2 and shank 3 are housed in the pin hole 6b. The body 4 is housed in the pin hole 6b in a state where the end surface 4a and the shaft 5 are exposed in the tread portion 6.

  The shaft 5 has a multi-stage structure including a plurality of steps. In the present embodiment, the shaft 5 includes three steps, that is, a first step 11, a second step 12, and a third step 13. The first to third step portions 11, 12, 13 of the shaft 5 include end faces 11a, 12a, 13a and side faces 11b, 12b, 13b, respectively. The step portion on the most proximal end step side, that is, the first step portion 11 projects from the end surface 4 a of the body 4. The intermediate step, that is, the second step 12 projects from the end surface 11 a of the first step 11. Furthermore, the step portion of the most tip end step, that is, the third step portion 13 projects from the end surface 12 a of the second step 12. The shaft 5 may have four or more steps.

  The total height of the shaft 5 (the height from the end surface 4a of the body 4 to the end surface 13a of the third step portion 13 in this embodiment) can be set to, for example, 0.5 mm or more and 3 mm or less. The ratio of the sum of the heights of the step portions other than the first step portion 11 (the sum of the heights of the second and third step portions 12 and 13 in the present embodiment) to the total height of the shaft is, for example, 10% or more. It can be set to 90% or less.

  In the first to third step portions 11, 12, and 13 of the shaft 5, the outer shape of the end faces 11a, 12a, and 13a in plan view is larger toward the body 4 side, that is, the base end side. Conversely, the outer shapes of the end surfaces 11a, 12a, 13a of the first to third step portions 11, 12, 13 of the shaft 5 in the plan view are smaller toward the tip end side. Therefore, the shaft 5 as a whole constitutes a stepped projection protruding from the end surface 4a of the body 4.

  In the present embodiment, the end surfaces 11a, 11b, 11c of the first to third step portions 11, 12, 13 are generally flat surfaces that are orthogonal to the axis A and spread. The end faces 11a, 11b, 11c may be inclined with respect to the axis AX, or may be non-flat faces.

  As shown most clearly in FIG. 2, the outer shape of the end faces 11a, 12a, 13a of the first to third step portions 11, 12, 13 in plan view is a pentagon, a quadrangle, and a pentagon, respectively. In the first step portion 11 in which the end surface 11a is a pentagon, the end surface 11a and the side surface 11b form five side or edge components 21a, 21b, 21c, 21d, 21e. Further, in the second step portion 12 in which the end face 12a is quadrangular, the end face 12a and the side face 12b form four side or edge components 22a, 22b, 22c, 22d. Further, in the third step portion 13 in which the end face 13a is pentagonal, the end face 13a and the side face 13b form five side or edge components 23a, 23b, 23c, 23d, 23e. In the present embodiment, the edge components 21a to 21e, 22a to 22d, 23a to 23e are linear. However, these edge components 21a to 21e, 22a to 22d, and 23a to 23e do not need to be linear in a geometrically strict sense, and are curved or meandered to some extent as long as a scratching effect on an ice and snow road surface is obtained. May be. Further, the edge components 21a to 21e, 22a to 22d, and 23a to 23e may be chamfered as long as the scratching effect on the ice and snow road surface can be obtained.

  As described above, the planar shape of the end surface 11a of the first step portion 11 is a pentagon, and the planar shape of the end surface 12a of the second end portion 12 is a quadrangle. That is, the first end portion 11 and the second end portion 12 of the shaft 5 have different outer shapes in plan view of the end surfaces 11a and 12a. Therefore, the edge components 21a to 21d of the first step portion 11 and the edge components 22a to 22d of the second step portion 12 have different directions in a plan view. More specifically, in a plan view, none of the edge components 22a to 22d of the second step portion 12 are parallel to any of the edge components 21a to 21e of the first step portion 11. That is, the shaft 5 has edge components oriented in multiple directions, as conceptually indicated by reference numeral E in FIG. 1, and these edge components act in multiple directions. As a result, the running performance on ice and snow roads is improved.

  The first step portion 11 has five edge components 21a to 21e, and the second step portion 12 has four edge components 22a to 22d. The end surface 12 a of the second step portion 12 is smaller than the end surface 11 a of the first step portion 11. In general, if the end faces of the stepped portion have the same size, the greater the number of edge components, the shorter the length of each edge component. Therefore, by setting the number of edge components of the first step portion 11 having the relatively large end surface 11a to be relatively large, the lengths of the individual edge components 21a to 21e can be secured and the edge components can be distributed in multiple directions. Can be secured. Further, by setting the number of edge components of the second step portion 12 whose end face 12a is relatively small to be relatively small, the length of each of the edge components 22a to 22d can be ensured while the number of edge components of the first step portion 11 is increased. The edge components 22a to 22d can be secured in a direction different from the edge components 21a to 21e. As a result, the running performance on the snowy and snowy road surface is improved more than when the outer shape of the end surface 11a of the first step portion 11 and the outer shape of the end surface 12a of the second step portion 12 are simply different.

  As described above, the end surface 13a of the third step portion 13, which is the most advanced step, is pentagonal and has five edge components 23a to 23e. In addition, the end surface 12a of the second step portion 12, which is the second step portion from the most advanced step, is a quadrangle and has four edge components 22a to 22d. That is, the number of edge components 23a to 23e of the third step portion 13 which is the most advanced step is larger than the number of edge components 22a to 22d of the second step portion 12 which is the second step from the most advanced step.

  With respect to each of the first to third step portions 11 to 13, the larger the number of edge components, the higher the effect of the step portion to pierce the ice and snow road surface. In addition, the third step portion 13, which is the most advanced step, has the highest piercing effect on the ice and snow road surface as compared with the first and second step portions 11 and 12. Therefore, by setting the number of edge components of the third step portion 13, which is the most advanced step, to be relatively larger than the number of edge components of the second step portion 12, the effect of the shaft 5 piercing the snow and snow road surface can be obtained. It effectively improves the driving performance on ice and snow roads.

  Generally, if the total number of steps of the shaft is an odd number, the number of edge components of the odd-numbered N + 1th step (N is a natural number) is greater than the number of edge components of the Nth step. By setting a large number, the number of edge components of the step portion of the most advanced stage becomes larger than the number of edge components of the second step portion from the most advanced stage. Similarly, if the total number of steps of the shaft is even, the number of edge components of the even (N + 1) -th step (N is a natural number) is calculated from the number of edge components of the N-th step. By also setting a large number, the number of edge components in the step portion of the most advanced stage becomes larger than the number of edge components in the second step portion from the most advanced stage.

  When the stud pin 1 is mounted on the tread portion 6a so that the rotational direction of the pneumatic tire 6 is the direction indicated by the arrow R1 in FIG. 2 with respect to the shape of the shaft 5 in plan view, the first step portion 11 The pointed portion 31g formed at the connecting portion of the edge components 21a and 21b of 3 and the pointed portion 33g formed at the connecting portion of the edge components 23a and 23b of the third step portion 13 are on the stepping side. Therefore, the piercing effect of these pointed portions 31g and 33g on the ice and snow road surface effectively contributes to the improvement of the drive torque. Further, in this case, the edge component 21d of the first step portion 11 and the edge component 22c of the second step portion 12 are on the start side. Therefore, the scratching effect of these edge components 21d and 22c on the snow and snow road surface effectively contributes to the improvement of the braking force.

  Hereinafter, other embodiments of the present invention will be described. Structures and functions that are not particularly referred to in these embodiments are similar to those in the first embodiment. Further, in the drawings related to these embodiments, the same or similar elements as those in the first embodiment are designated by the same reference numerals.

(Second embodiment)
In the stud pin 1 according to the second embodiment shown in FIGS. 5A and 5B, the outer shapes of the end faces 11a to 11c of the first to third step portions 11 to 13 in plan view are pentagon, square, and hexagon, respectively. Is. The first step portion 11 includes five edge components 21a to 21e, and the second step portion 12 includes four edge components 22a to 22d. Further, the third step portion 13 includes six edge components 23a-23f.

  The outer shapes of the first step portion 11 and the second step portion 12 in plan view are different, and the number of edge components of the second step portion 12 is four, which is the number of edge components of the first step portion 11. Less than an individual. Further, the number of edge components of the third stage 13 which is the most advanced stage is 6, which is larger than the number of edge components of the second stage 12 which is the second stage from the most advanced stage, which is four.

(Third Embodiment)
In the stud pin 1 according to the third embodiment shown in FIGS. 6A and 6B, the outer shapes of the end faces 11a to 11c of the first to third step portions 11 to 13 in plan view are hexagon, circle, and quadrangle, respectively. Is. The first step portion 11 includes six edge components 21a to 21f, and the circular second step portion 12 can be considered to have an infinite number of edge components. Further, the third step portion 13 includes four edge components 23a-23d.

  The outer shape of the first step portion 11 in a plan view is a hexagon, and the outer shape of the second step portion 12 in a plan view is a circular shape, which are different from each other.

(Fourth Embodiment)
In the stud pin 1 according to the fourth embodiment shown in FIGS. 7A and 7B, the outer shapes of the end faces 11a to 11c of the first to third step portions 11 to 13 in plan view are hexagonal, quadrangular, and pentagonal, respectively. Is. The first step portion 11 includes six edge components 21a to 21f, and the second step portion 12 includes four edge components 22a to 22d. Further, the third step portion 13 includes five edge components 23a-23e.

  The outer shapes of the first step portion 11 and the second step portion 12 in plan view are different, and the number of edge components of the second step portion 12 is four, which is the number of edge components of the first step portion 11. Less than an individual. Further, the number of edge components of the third stage 13 which is the most advanced stage is 5, which is larger than the number of edge components of the second stage 12 which is the second stage from the most advanced stage, which is four.

(Evaluation test)
As shown in Table 1 below, the comparative example and the stud pins of the first to fourth embodiments (all new) were subjected to evaluation tests of driving performance, braking performance, and turning performance.

As the test tire, tire size: 195 / 65R15 and air pressure Fr / Re: 220/220 (kPa) were used. In this evaluation test, test tires were mounted on a test vehicle (1500 cc, 4WD middle sedan vehicle) and run on an ice road surface. In the evaluation of the edge performance, the comparative example was set to 100 and the first to fourth embodiments were index-evaluated. The driving performance was evaluated based on the time from the standstill to the start of 30 m on the ice road surface. The braking performance was evaluated by the braking distance when a braking force was applied by an ABS (Antilock Brake System) at a speed of 40 km / h. The turning performance was evaluated by the turning radius when turning at a speed of 40 km / h.

  As shown in FIG. 8, the stud pin 1 of the comparative example does not have a multi-stage structure but has a shaft 5 formed of a single cylinder. Further, in each of the comparative example and the first to fourth embodiments, the stud pin 1 was attached to the test tire so that the tire rotating direction was the direction indicated by the arrow R1 in the drawing.

  The first to fourth embodiments in which the outer shapes of the first step portion 11 and the second step portion 12 in plan view are different from each other in comparison with the comparative example in terms of driving performance, braking performance, and turning performance. It demonstrated its performance.

DESCRIPTION OF SYMBOLS 1 Stud pin 2 Base 3 Shank 4 Body 4a End surface 4b Side surface 5 Shaft 11 1st step part 11a End surface 11b Side surface 12 2nd step part 12a End surface 12b Side surface 13 3rd step part 13a End surface 13b Side surface 6 Pneumatic tire 6a Tread part 6b Pin hole 21a, 21b, 21c, 21d, 21e, 21f Edge component 22a, 22b, 22c, 22d, 22e, 22f Edge component 23a, 23b, 23c, 23d, 23e, 23f Edge component 31g, 33g Sharp part

Claims (5)

Body and
A shaft protruding from the body,
The shaft includes a plurality of step portions including at least a first step portion protruding from the body, a second step portion protruding from the first step portion, and a third step portion protruding from the second step portion. It has a multi-stage structure,
A stud pin in which the outer shape of the first step portion in plan view is different from the outer shape of the second step portion in plan view.   The stud pin according to claim 1, wherein the number of the edge components of the second step portion is smaller than the number of the edge components of the first step portion.   The stud pin according to claim 1 or 2, wherein the number of edge components of the step portion of the most advanced stage is greater than the number of edge components of the second step portion from the most advanced stage. The total number of steps of the step portion of the shaft is odd,
4. The number of the edge components of the step portion of the (N + 1) th stage, which is an odd number stage, is larger than the number of the edge components of the stage portion of the Nth stage, according to claim 1. Stud pin. The total number of steps of the step portion of the shaft is an even number,
The number of the edge components of the step portion of the (N + 1) th stage that is an even number stage is larger than the number of the edge components of the step portion of the Nth stage. Stud pin.

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