JP2020066835A - Protective cap - Google Patents

Abstract

To provide a protective cap that relieves stress concentration against external impact.SOLUTION: A protective cap 1 of the present invention includes: a cap body 2 that covers a head of a wearer; a protective pad 3 made of synthetic resin that is detachably attached to an inside of the cap body 2; a synthetic resin hammock 10 detachably attached to the cap body 2 inside the protective pad 3; and a synthetic resin headband 11 detachably attached to a lower end of the hammock 10. The protective pad 3 includes: a forehead leg 36 extending from a crown to a frontal side; and an occipital leg 37 extending from the crown to an occipital region. Impact absorbers 40 are provided at lower ends of the legs 36 and 37, respectively. A stress buffer 60 made of a thermoplastic elastomer is provided on a back surface of the impact absorber 40. When an impact is applied to a frontal part side or an occipital part side of the cap body 2, the impact absorber 40 is crushed and absorbs the impact, and the impact is dispersed by the stress buffer 60.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a protective cap, and more particularly to a protective cap provided with a stress buffering portion that relieves stress concentration against external impact.

  The structure of a protective cap worn at a work site or the like is defined by a standard according to applications such as those for flying and falling objects, protection for a fall, and electricity. Protective caps for flying and falling objects are required to include a cap body, a hammock, a headband and a chin strap. Furthermore, a protective cap for crash protection is required to have a shock absorbing liner for absorbing a shock to the head, in addition to the cap body and the chin strap. Further, a protective cap that also serves as two standards for flying falling objects and for protection during a fall has a cap body, a hammock, a headband, a chin strap, and a shock absorbing liner. The shock absorbing liner is formed of, for example, styrofoam (see, for example, Patent Document 1).

  The impact absorbing liner made of styrofoam reduces the air permeability to the inside of the helmet and the heat dissipation from the inside. In order to improve this, there is known a protective cap in which a hammock and a shock absorbing liner are integrally formed so that the hammock has a shock absorbing function of the shock absorbing liner (for example, see Patent Document 2). This hammock is provided with a plurality of hexagonal tubular protrusions at positions corresponding to the frontal region and the occipital region, and is configured to absorb the impact by crushing the tubular protrusion when an external impact is applied.

JP, 2005-273107, A Japanese Patent No. 6247143

  The impact absorption liner made of Styrofoam receives a shock from the outside over a relatively large area, so the problem of stress concentration is unlikely to occur, but in the hammock of the shock absorption liner integrated type disclosed in the reference document 2, the Since the cylindrical projection has a small area and is relatively hard, there is a problem that stress concentration occurs in the shock absorber.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a protective cap that can relieve stress concentration on a shock absorber when a shock is applied from the outside.

In order to achieve the above object, the protective cap of the present invention is
A cap that covers the wearer's head,
A synthetic resin protective pad detachably attached to the inside of the cap body,
A hammock made of synthetic resin detachably attached to the cap body inside the protective pad,
A synthetic resin headband detachably attached to the lower end of the hammock,
Equipped with
The protective pad is provided with shock absorbers protruding from the inner surface of the cap body at positions corresponding to the frontal region and the back region of the head, and a stress buffer made of synthetic resin having elasticity is provided on the back surface of the shock absorbers. Has been.
According to the protective cap configured as described above, when an impact is applied to the front head side or the occipital side of the cap body from the outside, the shock is absorbed by the shock absorber and the received shock is applied to the back surface of the shock absorber. Dispersed by the stress buffer.

  According to the present invention, it is possible to reduce stress concentration on the shock absorber when a shock is applied from the outside.

It is a side view of the protective cap concerning one example of the present invention. It is a front view of the protective cap which concerns on one Example of this invention. It is a side view of the wearing body concerning one example of the present invention. It is a top view of the hammock concerning one Example of the present invention. It is a top view of the protection pad concerning one Example of the present invention. It is a top view shown in the state where the hammock and the protection pad were combined. It is a top view of the shock absorber which concerns on one Example of this invention. FIG. 6 is a sectional view of the shock absorber taken along the line AA of FIG. 5. It is a bottom view of the protection pad which shows the stress buffering part which concerns on one Example of this invention. FIG. 9 is a cross-sectional view of a stress buffering portion according to another embodiment corresponding to FIG. 8. It is a table which shows the shock absorption and stress distribution of the shock absorber which concerns on the Example and comparative example of this invention. It is a graph which shows the maximum impact load of the impact absorber which concerns on the Example and comparative example of this invention. It is a graph which shows the time-dependent change of the shock absorption load of the shock absorber which concerns on the Example and the comparative example which pre-processed at high temperature using the elastomer of hardness A68. It is a graph which shows the time-dependent change of the shock absorption load of the shock absorber which concerns on the Example and the comparative example which used the low temperature pretreatment using the elastomer of hardness A68. It is a graph which shows the time-dependent change of the shock absorption load of the shock absorber which concerns on the Example and the comparative example which performed the high temperature pretreatment using the elastomer of hardness A48. It is a graph which shows the time-dependent change of the shock absorption load of the shock absorber which concerns on the Example and the comparative example which pre-processed at low temperature using the elastomer of hardness A48. It is a top view of a protection pad which has a shock absorber concerning a 2nd example. It is a top view of the shock absorber which concerns on a 2nd Example. FIG. 11 is a cross-sectional view of the shock absorber and the stress buffer section taken along the line BB of FIG. 10. It is a figure which shows the stress buffer part in the back surface of the shock absorber which concerns on a 2nd Example. It is sectional drawing of the stress buffering part which concerns on the 2nd Example molded by two-color molding. It is a top view which shows the modification of the shock absorber which concerns on a 2nd Example. It is a top view which shows the other modification of the shock absorber which concerns on a 2nd Example. It is a top view which shows another modification of the shock absorber which concerns on a 2nd Example. It is a top view of the protection pad which has the shock absorber which concerns on the 3rd Example of this invention. It is a top view of the 1st impact absorption body which concerns on a 3rd Example. FIG. 27 is a cross-sectional view of the first shock absorber and the stress buffer section taken along the line C-C of FIG. 26. It is a top view of the 2nd impact absorption body which concerns on a 3rd Example. FIG. 29 is a cross-sectional view of the second shock absorber and the stress buffer section taken along line DD of FIG. 28. It is a bottom view of the shock absorber which shows a stress buffering part based on a 3rd Example. It is a table | surface which shows the shock absorption measured in the state which does not have a stress buffer part about the shock absorber which concerns on a 3rd Example and a comparative example. It is a table | surface which shows the shock absorption property and stress concentration avoidance property of the shock absorber which concerns on a 3rd Example and a comparative example. It is a table | surface which shows the shock absorption of the 1st and 2nd shock absorbers which concern on a 3rd Example. It is a bottom view of the protection pad provided with the shock absorber concerning the modification of the 3rd example. It is a bottom view of the shock absorber which shows the stress buffering part which concerns on a modification. FIG. 36 is a cross-sectional view of a shock absorber and a stress buffer section according to a modified example taken along line EE of FIG. 35.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a side view of a protective cap according to an embodiment of the present invention, and FIG. 2 is a front view of the protective cap. As shown in FIGS. 1 and 2, the protective cap 1 according to the present embodiment is a helmet for protecting especially at the time of a crash, and includes a cap body 2 (shown by a broken line) for covering a wearer's head and a cap body 2. A protective pad 3 that is detachably attached to the inside to reduce the impact transmitted to the head, a wearing body 4 that is detachably attached to the cap body 2 inside the protective pad 3, and the protective cap 1 is fixed to the head. And a chin strap 5 (shown by a broken line). Here, in the following description, in order to facilitate understanding, a direction extending over the front head and the back head of the protective cap 1 is referred to as a front-back direction X, and a vertical direction of the protective cap 1 is indicated with a symbol Y. Further, a direction extending over both head portions of the protective cap 1 is referred to as a width direction Z. In addition, the term “left and right” will be used with reference to the posture of FIG. Therefore, it should be understood that “left and right” in the specification is opposite to “left and right” of the wearer when the protective cap 1 is actually worn.

  The cap body 2 is made of ABS (acrylonitrile butadiene styrene), PC (polycarbonate), PE (polyethylene), FRP (fiber reinforced plastic) or the like having a predetermined strength and rigidity, and is formed into a substantially hemispherical shell shape. The cap body 2 has an eaves portion 2a projecting forward on the frontal portion side. Further, in the vicinity of the lower end of the inner side surface 6 of the cap body 2, a plurality of attachment projections 7 for attaching the protective pad 3, the wearing body 4 and the chin strap 5 to the cap body 2 are integrally formed. In the present embodiment, four attachment protrusions 7, that is, a total of eight attachment protrusions 7 are provided on each of the left and right sides of the cap body 2 at predetermined intervals.

  A pair of left and right ear hooks 8 are attached to the attachment protrusions 7 via attachment pieces (not shown). The chin straps 5 are attached to the ear hook straps 8, respectively. The ear straps 8 and the chin straps 5 are formed of, for example, a synthetic fiber tape woven of resin fibers such as polypropylene or a tape made of EVA resin (ethylene vinyl acetate copolymer).

  FIG. 3 is a side view of the wearing body 4. The wearing body 4 is detachably attached to the cap body 2 via the attachment protrusions 7, and the hammock 10 that holds the hat body 2 on the head and the hammock 10 is detachably attached to the head body 2 on the head body 2. And a headband 11 to be fixed. The headband 11 is made of synthetic resin such as polyethylene or polypropylene. The headband 11 includes a belt-shaped main body 12 arranged along the inner surface 6 on the lower end side of the cap body 2, a hammock engagement portion 13 protruding upward from the main body 12, and a wearer's head circumference. And an adjusting portion 14 for adjusting the length of the main body portion 12 according to the above. The hammock engaging portions 13 are provided at two locations, respectively, at a location corresponding to the temporal region of the cap body 2, at a total of four locations. A plurality of pin engagement holes 15 are formed in the hammock engagement portion 13, and a mounting pin 16 is inserted into one pin engagement hole 15. The adjusting portion 14 is provided at one end of the main body 12 and has a slot (not shown) into which the other end of the main body 12 is inserted. The length of the headband 11 is adjusted by the amount of insertion of the main body 12 inserted into this slot.

FIG. 4 is a top view showing the hammock 10 which is detached from the cap body 2 and is developed in a plane shape. The hammock 10 is a member that comes into direct contact with the wearer's head, and absorbs the shock by expanding when a shock is applied from the outside. The hammock 10 is made of synthetic resin such as polyethylene or polypropylene. The hammock 10 is formed symmetrically along a centerline CL _H extending in the front-rear direction X, and has a substantially rectangular connecting portion 20 located at the top of the head and eight legs radially extending from the connecting portion 20. And parts 21, 22, 23, and 24. The connecting portion 20 includes a substantially rectangular first opening portion 25 provided in the center and four substantially trapezoidal second portions provided outside the first opening portion 25 and at each corner portion of the connecting portion 20. And an opening 26.

  The legs 21, 22, 23, 24 respectively extend from the respective corners of the connecting portion 20, and have a pair of front hammock legs 21a, 21b located on the frontal region side and a pair of rear regions located on the occipital region side. It includes hammock legs 22a and 22b, a pair of left hammock legs 23a and 23b located on the left head side, and a pair of right hammock legs 24a and 24b located on the right head side. The front hammock legs 21a and 21b and the rear hammock legs 22a and 22b are separated from each other with a distance D1. The left hammock legs 23a and 23b and the right hammock legs 24a and 24b are spaced apart from each other by a distance D2 shorter than the distance D1. The front hammock leg 21a and the left hammock leg 23b, and the front hammock leg 21b and the right hammock leg 24a are connected to each other via a strip-shaped connecting piece 27. Similarly, the rear hammock leg 22 a and the right hammock leg 24 b, and the rear hammock leg 22 b and the left hammock leg 23 a are connected to each other via a connecting piece 27. The legs 21, 22, 23, and 24 have a predetermined rigidity so that when the protective cap 1 receives an impact from above, it deforms and extends to absorb the impact. An attachment piece 28 for attaching the headband 11 to the hammock 10 is integrally formed with the connecting piece 27. The mounting piece 28 extends downward from the connecting piece 27 toward the headband 11, and has a plurality of mounting holes 29 for receiving the mounting pins 16 on the headband 11 side. The headband 11 is attached to the hammock 10 by inserting the attachment pin 16 into one attachment hole 29. Further, the legs 21, 22, 23, and 24 each have an engaging portion 31 at a lower end portion for engaging with the attachment projection 7 provided on the cap body 2 to attach the wearing body 4 to the cap body 2. is doing. Further, the leg portions 21, 22, 23, and 24 are respectively provided with a protrusion 32 between the engagement portion 31 and the base end portion on the second opening 26 side and at a position near the engagement portion 31. . The protrusion 32 is a hollow cylindrical protrusion, and has a predetermined rigidity so that the protective cap 1 absorbs the shock by being crushed when the shock is applied from the outside. The protrusion 32 projects from the legs 21, 22, 23, 24 toward the inner side surface 6 of the cap body 2, but does not contact the inner side surface 6. Therefore, the shock absorbing property of the hammock 10 that absorbs the shock due to the stretching is not hindered.

FIG. 5 is a top view showing the protection pad 3 in a state where the protection pad 3 is removed from the cap body 2 and expanded in a plane. The protective pad 3 is made of a synthetic resin such as polyethylene or polypropylene, and is made of polyethylene in this embodiment. Protective pads 3 are formed symmetrically along the center line CL _P extending in the front-rear direction X, the cap body and the connecting part 35 facing the top of the 2, 4 legs extending from the connecting portion 35 36, 37, 38, 39. Legs 36, 37 has a center line CL before respectively extending in the longitudinal direction X along the _P head legs 36 (first leg) and occipital legs 37 (second leg ), And a left head leg portion 38 and a right head leg portion 39 that extend in the width direction Z orthogonal to the front head leg portion 36 and the occipital leg portion 37, respectively. The forehead leg portion 36 and the occipital region leg portion 37 are tapered from the base end portion on the side of the connecting portion 35 toward the lower end portion, and the lower end portion is provided with the shock absorber 40. The leg portions 36, 37, 38, 39 are for fixing the protective pad 3 at a predetermined position in the cap body 2 and for arranging the shock absorber 40 at a predetermined position, and the leg portions of the hammock 10 are provided. Unlike 21, 22, 23 and 24, it does not have a function of absorbing shock by being deformed and elongated. The shock absorber 40 is arranged at a position corresponding to the front head and the back head of the wearer. That is, the lengths of the forehead leg portion 36 and the occipital region leg portion 37 are set so that the shock absorber 40 is arranged at a position corresponding to the forehead and the occipital region. Further, the forehead leg portion 36 and the occipital region leg portion 37 are provided with a substantially triangular opening 41 between the base end portion and the shock absorber 40. On the other hand, the left head leg portion 38 and the right head leg portion 39 are provided with mounting portions 42 at their lower ends. The attachment portion 42 is in the form of an elongated strip extending in the front-rear direction X, and extends substantially horizontally along the inner side surface 6 at the lower end portion of the cap body 2 (see FIG. 1). The mounting portion 42 has a mounting hole 43 formed in the vicinity of the end portions on the frontal region side and the occipital region side, into which the mounting protrusions 7 of the cap body 2 engage. The protective pad 3 is detachably attached to the cap body 2 by engaging the attaching hole 43 and the attaching projection 7. The forehead leg portion 36 and the occipital region leg portion 37 are not directly attached to the cap body 2. Further, the left head leg portion 38 and the right head leg portion 39 are provided with a substantially triangular opening 44 formed in an opening near the connecting portion 35, and projecting between the opening 44 and the mounting portion 42. The two first shock absorbing protrusions 45 are provided respectively. The first shock absorbing protrusions 45 are arranged at predetermined intervals along the longitudinal direction of the legs 38, 39. The first impact absorbing protrusion 45 is a hollow cylindrical protrusion, and has a predetermined height so as to abut the inner side surface 6 of the cap body 2 on the temporal region side. The connecting portion 35 has an opening 47 formed in the center and six second shock absorbing protrusions 48 arranged along the periphery of the opening 47. The second shock-absorbing projections 48, protective pads are arranged in a circumferential direction at a pitch of 60 ° around the center C of 3, before the two second shock-absorbing projections 48 on the center line CL _P They are arranged on the head side and the occipital side, respectively. The second shock-absorbing protrusion 48 is a hollow cylindrical protrusion similar to the first shock-absorbing protrusion 45, and protrudes so as to come into contact with the inner surface 6 at the crown of the cap body 2. . The second impact absorbing protrusion 48 has a predetermined height such that the connecting portion 35 and the inner surface 6 are separated from each other by a predetermined distance. The opening 47 has six notches partially extending between the second shock absorbing protrusions 48 so as to improve the followability of the second shock absorbing protrusions 48 with respect to the inner surface 6. ing.

  Further, the protective pad 3 includes four auxiliary leg portions 50 extending from the connecting portion 35. The auxiliary legs 50 are arranged at a pitch of 90 ° with the center C as the center. In other words, the auxiliary leg portion 50 includes the front head leg portion 36 and the left head portion leg portion 38, the front head leg portion 36 and the right head portion leg portion 39, and the occipital portion leg portion 37 and the left head portion. It is disposed between the leg portion 38 and between the occipital region leg portion 37 and the right temporal region leg portion 39, respectively. The auxiliary leg portion 50 has a third impact absorbing protrusion 51 at the lower end. The third shock absorbing protrusion 51 is a hollow cylindrical protrusion similar to the shock absorbing protrusions 45 and 48, and has a predetermined height so as to come into contact with the inner surface 6 of the cap body 2. Is protruding. The auxiliary leg portion 50 has a length relatively shorter than the length of the leg portions 36, 37, 38, 39, and has a third impact absorption more than that of the impact absorption protrusions 45 provided on the leg portions 38, 39. The length is set so that the protrusion 51 is located above, that is, on the crown side (see FIG. 1). Each of the shock absorbing projections 45, 48, 51 provided on the protective pad 3 has a predetermined rigidity so as to absorb the shock by being crushed when the protective cap 1 receives an external shock. . When the impact from above on the protective cap 1 is relatively small, the hammock legs 21, 22, 23, 24 are deformed in the space between the connecting portion 35 of the protective pad 3 and the connecting portion 20 of the hammock 10. Since the second shock absorbing protrusions 48 are not crushed because they absorb the shock by being stretched, they do not absorb the shock. On the other hand, when a relatively large impact is applied to the protective cap 1 such that the extension of the hammock 10 cannot be absorbed in the space between the connecting portion 35 and the connecting portion 20, that is, when the protective cap 1 is overloaded, the second impact is applied. The absorbing protrusions 48 are sandwiched between the cap body 2 and the hammock 10 and are crushed to absorb the impact.

  As shown in FIG. 6, when the protective pad 3 is overlaid on the hammock 10, the forehead leg portion 36 of the protective pad 3 and the shock absorber 40 provided on the leg portion 36 serve as a front hammock. It is arranged between the leg portions 21a and 21b, that is, at an interval D1. Similarly, the occipital region leg portion 37 and the shock absorber 40 provided on the leg portion 36 are arranged between the rear hammock leg portions 22a and 22b, that is, in the interval D1. On the other hand, the left head leg portion 38 extends between the left hammock legs 23a and 23b, that is, within the space D2, and the right head leg portion 39 extends between the right hammock legs 24a and 24b. That is, it extends within the interval D2. The auxiliary leg portion 50 includes a front hammock leg portion 21a and a left hammock leg portion 23b, a front hammock leg portion 21b and a right hammock leg portion 24a, a rear hammock leg portion 22a and a right hammock leg portion 24b. , And between the rear hammock leg 22b and the left hammock leg 23a. The third shock absorbing protrusion 51 provided on the auxiliary leg 50 is located above the protrusions 32 provided on the hammock legs 21, 22, 23, and 24, that is, on the top of the head. . The connecting portion 20 of the hammock 10 and the connecting portion 35 of the protective pad 3 are positioned so as to face each other, and the first opening 25 of the hammock 10 and the opening 47 of the protective pad 3 are arranged in the vertical direction. Aligned to Y. Since the hammock 10 and the protection pad 3 shown in FIG. 6 are shown by being removed from the cap body 2 and developed in a plane, the positional relationship between the hammock 10 and the protection pad 3 is as shown in FIGS. It is to be understood that the positional relationship when attached to the cap body 2 shown in FIG.

  Further, as shown in FIG. 1, the protective pad 3 is curved along the inner side surface 6 of the cap body 2, and the shock absorber 40 and the shock absorbing protrusions 45, 48, 51 contact the inner side surface 6, The mounting portion 42 engages with the mounting projection 7 and is mounted on the cap body 2. Then, the engaging portions 31 of the right hammock leg portions 24a and 24b and the engaging portions 31 of the left hammock leg portions 23a and 23b are respectively overlapped on the mounting portion 42 and engaged with the mounting protrusions 7, so that the hammock is engaged. 10 is attached to the cap body 2 in a state of being curved along the protection pad 3. At this time, the hammock 10 is not in contact with the protective pad 3 except for the mounting portion 42 and the engaging portion 31. That is, the hammock 10 and the protective pad 3 are separated from each other with a predetermined space. In particular, the connecting portions 20 and 35 are separated by a sufficient distance so that the connecting portion 20 of the hammock 10 and the connecting portion 35 of the protective pad 3 do not come into contact with each other when an impact is applied from the outside. A space is formed between them.

  Next, the shock absorber 40 will be described in detail with reference to FIGS. 7 is an enlarged view of the shock absorber 40, and FIG. 8 is a cross-sectional view of the shock absorber 40 taken along the line AA of FIG. The shock absorber 40 includes a rectangular base portion 53, a prismatic portion 54 protruding from the center of the base portion 53, convex wall portions 55 protruding along the four sides of the base portion 53, and a prismatic portion 54. And a connecting wall portion 56 that connects the convex wall portion 55. The base portion 53 is a flat plate member having a rounded rectangular shape that is long in the direction along the legs 36 and 37. The prismatic portion 54 is a hollow prismatic protrusion. The convex wall portion 55 has a substantially convex cross-section, and is arranged such that the narrow top portion is located inside the base portion 53, that is, the prismatic portion 54 side, and the wide bottom portion is located outside the base portion 53. Has been done. The bottom of the convex wall portion 55 is open outward. A circular through hole 57 is formed in the base portion 53 in a space surrounded by the convex wall portion 55. As shown in FIG. 8, the convex wall portion 55, the prismatic portion 54, and the connecting wall portion 56 are moved downward from the top of the head in accordance with the curved shape of the inner side surface 6 so as to contact the inner side surface 6 of the cap body 2. The height is gradually decreasing toward. Further, the convex wall portion 55, the prismatic portion 54, and the connecting wall portion 56 have a predetermined rigidity so that the protective cap 1 is crushed when it receives an impact from the outside to absorb the impact. Further, a stress buffer 60 is provided on the back surface of the base 53.

  Next, the stress buffer section 60 will be described in detail with reference to FIGS. The stress buffer 60 is a member that disperses the shock (stress) absorbed by the shock absorber 40 and relieves the concentration of stress on the shock absorber 40 and further on the frontal region or the occipital region. The stress buffer 60 has the same size as the base 53 of the shock absorber 40, and is made of an elastic synthetic resin such as an elastomer or rubber. In this embodiment, the stress buffer section 60 is made of thermoplastic elastomer (TPE). The thermoplastic elastomer is a styrene-based thermoplastic elastomer (TPS), an olefin-based thermoplastic elastomer (TPO) or a urethane-based thermoplastic elastomer (TPU). In one embodiment, the stress buffer 60 has a hardness of 68 when measured with a durometer type A, and is formed of a thermoplastic elastomer having a thickness of 2 mm, or two thin plate-like elastomers having a thickness of 1 mm. It is formed by overlapping (corresponding to the first embodiment in FIG. 11). In another embodiment, the stress buffer 60 has a hardness of 48 when measured with a durometer type A and is made of a thermoplastic elastomer having a thickness of 3 mm, or a thin plate-shaped elastomer having a thickness of 1 mm. Are formed by stacking three sheets (corresponding to the second embodiment in FIG. 11).

  In this embodiment, the protection pad 3 and the stress buffering portion 60 are molded by two-color molding. That is, after polyethylene, which is the first material, is injected into the cavity of the mold to mold the protective pad 3 having the shock absorber 40, thermoplastic resin, which is the second material, is filled in the cavity for molding the stress buffer 60. The elastomer is injected in a thin plate shape with a thickness of several mm (for example, 2 to 3 mm) to form the stress buffer section 60 on the back surface of the shock absorber 40. As shown in FIG. 8, the stress buffering portion 60 after molding protrudes through the through hole 57 into the space surrounded by the convex wall portion 55 and is held by the shock absorber 40. In another embodiment shown in FIG. 10, the stress buffer section 60 is formed by insert molding. That is, after preliminarily molding a thin plate-like elastomer having a size substantially the same as that of the shock absorber 40 and a thickness of 1 mm, a plurality of (for example, 2 to 3) molded elastomers are overlapped to form a protective pad. The protection pad 3 is molded by setting it in the mold for 3. In this embodiment, the through hole 57 is used to receive a pin for holding the molded thin plate-shaped elastomer in the mold for the protective pad 3. The stress buffer portion 60 after molding partially protrudes to the surface side of the base portion 53 through the through hole 57.

  In the above structure, when an external shock is applied to the protective cap 1, the hammock 10 extends and absorbs the shock, and the shock absorbing projections 45, 48, 51 formed on the protective pad 3 are crushed to absorb the shock. Absorb. In particular, when a shock is applied to the frontal region or the occipital region, the shock absorber 40 is crushed and the shock is absorbed, and the shock (stress) is dispersed by the stress buffer section 60 provided in the shock absorber 40. . Therefore, the stress concentration on the shock absorber 40 and further on the frontal region or the occipital region is relieved.

  A stress concentration relaxation performance test was conducted on the first and second examples of the present invention and the first to fifth comparative examples. The first comparative example is a shock absorber having no stress buffer. The first example, the second comparative example, and the third comparative example are shock absorbers provided with a stress buffer portion made of a thermoplastic elastomer having a hardness of 68 when measured with a durometer type A. Is a thermoplastic elastomer having a thickness of 2 mm (2 sheets), the second comparative example is a thermoplastic elastomer having a thickness of 1 mm (1 sheet), and the third comparative example is a thermoplastic elastomer having a thickness of 3 mm (3 sheets). There is. On the other hand, the second example, the fourth comparative example, and the fifth comparative example are shock absorbers having a stress buffer portion made of a thermoplastic elastomer having a durometer type A hardness of 48, and the second example is thick. 3 mm (three sheets) of thermoplastic elastomer, the fourth comparative example uses 1 mm (1 sheet) thick thermoplastic elastomer, and the fifth comparative example uses 2 mm (2 sheets) thick thermoplastic elastomer.

  (Test method) Industrial protective caps are required to have the performance specified in the Ministry of Health, Labor and Welfare protective caps standard (labor inspection test). There are two types of tests related to impact absorption performance: a test for flying drops and a test for protection during a fall. In the flying drop test, a human head model is installed on the load cell of a shock absorbing tester for a protective cap, and the protective cap is attached to the human head model. Then, a hemispherical 5 kg weight is dropped freely from a height of 1 m onto the top of the protective cap, and the impact value (impact load) received by the human head model is measured. On the other hand, in the test for crash protection, a human head model with a centerline inclined 30 degrees to the horizontal was installed on the load cell of the shock absorption tester for a protective cap, and the protective cap was attached to this human head model. To do. Then, a flat weight of 5 kg is freely dropped from a height of 1 m so that the impact points are the front head and the back of the protective cap, and the impact value received by the human head model is measured.

  For this example, the impact absorber was measured using a fall protection test. First, as a pretreatment before conducting the test, a pretreatment step of leaving the impact absorber for 2 hours in an environment of a high temperature of about 50 ° C and a low temperature of about -10 ° C according to a test according to the Ministry of Health, Labor and Welfare protective cap standard. A pretreatment step of leaving the shock absorber in the environment for 2 hours was performed. Then, an experiment was conducted on the shock absorbers that have undergone the respective steps under the following conditions. A metal disk having a thickness of 10 mm was installed on the load cell of the shock absorption tester for the protective cap, and the shock absorber was placed on this disk. Then, a weight of a flat plate of 5 kg was allowed to fall freely from a height of 1 m toward the shock absorber, and the shock value received by the load cell was measured. Further, a pressure measurement film (manufactured by Fuji Film Co., Ltd.) was sandwiched between the shock absorber and the disc, and the stress distribution received by the disc was visually confirmed.

  (Test Results) The test results are shown in FIGS. FIG. 11 is a table showing the impact absorption of each sample and the stress distribution by the pressure measurement film. FIG. 12 is a graph showing the maximum impact value for each sample. In the table of FIG. 11, the maximum impact value of the first comparative example having no stress buffer is set as a reference value, and the maximum impact value that is equal to or larger than the reference value is “x”, the difference between the reference value and the maximum impact value. Shows a value of −0.1 to −0.4 kN as “Δ”, a value of −0.5 to −1.0 kN as “◯”, and a value of −1.1 kN or more as “⊚”. It was As shown in FIG. 12, the first comparative example having no stress buffer shows a relatively high maximum impact value in both the high temperature treatment and the low temperature treatment. On the other hand, in the first example, the second comparative example and the third comparative example using the thermoplastic elastomer having the hardness of A68, the maximum impact value when the high temperature treatment is performed is the same, When the low temperature treatment is performed, the first example and the third comparative example show relatively low maximum impact values. Regarding the stress distribution shown in FIG. 11, in the first comparative example, the impact mark of the impact absorber 40 is clearly shown on the pressure measurement film, and it can be seen that the stress concentration is not relaxed. On the other hand, in the first example and the third comparative example, it can be seen that the stress is dispersed as compared with the first comparative example and the second comparative example. On the other hand, regarding the second example, the fourth comparative example, and the fifth comparative example using the thermoplastic elastomer having the hardness of A48, the second example is either the case where the high temperature treatment is performed or the case where the low temperature treatment is performed. Also in the above, the maximum impact value is lower than those of the fourth comparative example and the fifth comparative example. Regarding the stress distribution, it can be seen that the second example favorably disperses the stress as compared with the fourth and fifth comparative examples. Further, as shown in FIGS. 13 to 16, in the first comparative example having no stress buffer, the time required to reach the maximum impact value is relatively short. On the other hand, the shock absorber including the stress buffering portion made of the thermoplastic elastomer takes a relatively long time to reach the maximum shock value, and the effect is remarkable especially in the first and second embodiments. I was seen.

  According to the protective cap 1 configured as described above, when a shock is applied from the outside to the frontal part side or the occipital part side of the cap body 2, the shock is absorbed by the shock absorber 40, and the received shock is impacted. Since it is dispersed by the stress buffer section 60 on the back surface of the absorber, stress concentration on the shock absorber 40 can be relaxed. Further, by forming the protective pad 3 and the hammock 10 as separate bodies, it is possible to widen the selection range of the shapes and materials of the protective pad 3, the hammock 10, the shock absorber 40, and the shock absorbing protrusions 45, 48, 51. You can In addition, by forming the protective pad 3 and the hammock 10 as separate bodies, the shock absorber 40 and the shock absorbing projections 45, 48, 51 provided on the protective pad 3 are crushed to absorb the shock, and the deformation and extension are achieved. It is possible to make the hammock 10 function well without interfering with both of the shock absorbing property of the hammock 10. Further, by forming the protective pad 3 and the hammock 10 as separate bodies from a synthetic resin material, the shock absorber 40 and the shock absorbing protrusions 45, 48, 51 can be arranged at desired positions on the protective pad 3. . Further, since the second shock absorbing protrusion 48 provided on the protective pad 3 maintains a constant space between the inner side surface 6 of the cap body 2 and the connecting portion 35, the penetration resistance performance is improved.

  Next, a second embodiment of the shock absorber will be described with reference to FIGS. The same components as those in the above-described embodiment are designated by the same reference numerals, and duplicated description will be omitted. The forehead leg portion 36 and the occipital region leg portion 37 of the protective pad 3 respectively include a shock absorber 140 at the lower end portion. As shown in FIG. 18, the shock absorber 140 includes a substantially cruciform base portion 153, a prismatic portion 154 projecting from the center of the base portion 153, and a plan view arranged adjacent to four sides of the prismatic portion 154. And four D-shaped projections. The base portion 153 is formed in a cross shape in which the dimension in the leg portions 36, 37 direction is larger than the dimension in the width direction Z. The prismatic portion 154 is a hollow octagonal protrusion in plan view. The four protrusions include a pair of first protrusions 155a and 155b and a pair of second protrusions 158. The first protrusions 155a and 155b are respectively adjacent to the upper end side (that is, the crown side) and the lower end side of the prismatic portion 154, and the second protrusion 158 is the left side of the prismatic portion 154 and They are adjacent to each other on the right side. The first protrusions 155 a, 155 b and the second protrusion 158 have an outer wall portion curved in an arc shape and a linear inner wall portion, and the outer wall portion is located outside the base portion 153. Are projected respectively. The inner wall portion located inside the base portion 153 constitutes a peripheral wall of the prismatic portion 154. That is, the prismatic portion 154 is defined by the inner wall portions of the first and second protrusions 155a, 155b, 158. Further, the internal space of the prismatic portion 154 is divided into two in the direction of the leg portions 36, 37, that is, vertically by a partition wall 156 rising from the base portion 153. A shock absorbing protrusion 159a is provided in a space inside the first protrusion 155a, and a circular through hole 157 is opened below the shock absorbing protrusion 159a, that is, at a position near the prismatic portion 154. Has been formed. The shock absorbing protrusion 159a is a hollow cylindrical protrusion and is lower in height than the first protrusion 155a, as shown in FIG. On the other hand, only the through hole 157 is formed in the space inside the first protrusion 155b. In the space inside the second protrusion 158, cylindrical impact absorbing protrusions 159b are provided so as to protrude. The height of the shock absorbing protrusion 159b is set lower than that of the second protrusion 158. In this manner, the height of the first protrusion 155a and the height of the shock absorbing protrusion 159a, and the height of the second protrusion 158 and the height of the shock absorbing protrusion 159b are made different from each other. Shock absorption is possible. That is, the first protrusions 155a and 155b and the second protrusion 158, which are relatively large in height, absorb the impact against a weak impact from the outside, and the protrusions absorb a stronger impact. In addition to 155a, 155b, 158, the shock absorber 140 is configured to absorb the shock by the shock absorbing protrusions 159a, 159b having a small height.

  As shown in FIGS. 19 and 20, the shock absorber 140, that is, the back surface of the base 153 is provided with a stress buffer 160. The stress buffer section 160 is substantially the same as the stress buffer section 60 in the first embodiment except that the shape is different. That is, the stress buffer 160 has the same size as the base 153 of the shock absorber 140, and has a predetermined thickness (for example, 2 mm to 3 mm) and a predetermined hardness (durometer type A hardness 48 or 68). ) Is included in the thermoplastic elastomer. The stress buffer 160 is formed by insert molding (see FIG. 19) or two-color molding (see FIG. 21).

  In the above-described configuration, similarly to the first embodiment, when a shock is applied to the front head or the back head, the shock absorber 140 is crushed and the shock is absorbed, and the shock (stress) is the shock absorber 140. Are dispersed by the stress buffer 160 provided on the back surface of the. Therefore, the stress concentration on the shock absorber 140 and further on the frontal region or the occipital region is relieved. The stress buffering portion 160 according to the present embodiment also provides the same stress concentration avoidance as the stress buffering portion 60 according to the above embodiment.

  (Modification) As a modification of the shock absorber 140 according to the second embodiment, the shock absorbers 240A to 240C shown in FIGS. The shock absorber 240A shown in FIG. 22 is obtained by removing the through hole 157 from the shock absorber 140. The shock absorber 240B shown in FIG. 23 is obtained by removing the shock absorbing protrusions 159a and 159b from the shock absorber 240A. The shock absorber 240C shown in FIG. 24 is obtained by removing the partition wall 156 from the shock absorber 240B. With the shock absorbers 240A to 240C configured in this manner, the same shock absorbability and stress concentration avoidance as the shock absorber 140 can be obtained.

  Next, a third embodiment of the shock absorber will be described with reference to FIGS. The same components as those in the above-described embodiment are designated by the same reference numerals, and duplicated description will be omitted. In the present embodiment, as shown in FIG. 25, the protective pad 3 includes a first shock absorber 340 at the lower end of the forehead leg 36 and a second shock absorber at the lower end of the occipital leg 37. The body 341 is provided. That is, the first shock absorber 340 is a shock absorber for the forehead, and the second shock absorber 341 is a shock absorber for the occipital region. As described above, in this embodiment, the shock absorbers having different shapes in the frontal region and the back region are used.

  As shown in FIGS. 26 and 28, the first shock absorber 340 and the second shock absorber 341 are adjacent to the substantially cruciform base portion 353, the octagonal prismatic portion 354 in plan view, and the prismatic portion 354. And four projecting portions arranged in a D shape in plan view. The base 353 is curved so as to follow the front and back of the wearer's head (see FIGS. 27 and 29). The protrusions are a pair of first protrusions 355 that are respectively adjacent to the upper end side (that is, the crown side) and the lower end side of the prismatic portion 354, and are adjacent to the left side and the right side of the prismatic portion 354, respectively. And a pair of second protrusions 358.

  The first protrusion 355 has an outer wall portion 355a curved in an arc shape, and a linear inner wall portion 355b (second wall portion) extending along the left-right direction (second direction) of the base portion 353. is doing. Similarly, the second protrusion 358 has an outer wall portion 358a curved in an arc shape and a linear inner wall portion 358b (first wall portion) extending along the front-rear direction (first direction) of the base portion 353. ,have. Unlike the shock absorber 140 of the second embodiment, the first and second shock absorbers 340 and 341 are not provided with partition walls inside the prismatic portion 354, and the first and second protrusions 355 are provided. , 358 have no shock absorbing projections or through holes.

  As shown in FIG. 26, in the first impact absorber 340 for the forehead, the notches 362 are formed in the inner wall portions 358b (first wall portions) of the pair of second protrusions 358, respectively. There is. That is, the pair of notches 362 face each other in the left-right direction (second direction) of the base portion 353. As shown in FIG. 27, the notch 362 extends over the entire height of the inner wall portion 358b and has a trapezoidal shape whose width becomes narrower from the upper bottom to the lower bottom. The upper bottom of the cutout 362 extends over the entire width of the inner wall portion 358b, and the lower bottom extends along the base 353.

  As shown in FIG. 28, in the second impact absorber 341 for the back of the head, of the pair of first protrusions 355, the inner wall portion 355b (the second protrusion 355) of the first protrusion 355 located on the leg 37 side is located. A notch 363 is formed in the wall). As shown in FIG. 29, the notch 363 has the same shape as the notch 362 of the first shock absorber 340, and has a trapezoidal shape over the entire height of the inner wall portion 355b.

  As shown in FIG. 30, a cross-shaped stress cushioning portion 360 is provided on the back surfaces of the first shock absorber 340 and the second shock absorber 341. The stress buffer portion 360 extends over the entire back surface of the base portion 353, and rises toward the opposite side, that is, the first and second protrusions 355, 358 side so as to surround the edge portion of the base portion 353 (FIG. 27, 29). The stress buffer 360 may be formed of a thermoplastic elastomer (TPE) having a hardness of 50 to 80 when measured with a durometer. In this embodiment, the stress buffering section 360 is formed of a thermoplastic elastomer having a hardness of 60 when measured with a durometer.

  Further, the stress buffering section 360 has four stress buffering projections 365 which are circular in plan view. The stress buffering convex portion 365 includes both end portions in the left-right direction of the cross-shaped stress buffering portion 360, an upper end portion 360a on the leg portion 36 (37) side in the front-rear direction, and a lower end portion 360b (that is, the leg portion It is provided at four locations, one on the opposite side and the other. That is, as shown in FIGS. 27 and 29, the stress buffering section 360 includes the back surface of the first protrusion 355 located on the leg 36 (37) side of the pair of first protrusions 355, and the pair of second protrusions 355. Are provided on the back surface of the protruding portion 358 and the substantially back surface of the prismatic portion 354, respectively. The stress buffering convex portion 365 extends over most of the width W of the cross-shaped portion extending in the front-rear direction and the portion extending in the left-right direction.

As shown in FIG. 27, the stress buffering convex portion 365 projects in a dome shape in a direction away from the base portion 353, that is, toward the front and back of the wearer's head. The stress buffer 360 has a maximum thickness t ₁ to a minimum thickness t ₂ . The maximum thickness t ₁ is the height of a perpendicular line drawn from the center c of the stress buffering convex portion 365 having a circular shape in plan view to the back surface of the base portion 353, and the minimum thickness t ₂ is the stress buffering convex portion 365. It is the thickness of the stress buffering portion 360 at the non-existing portion. In this example, the maximum thickness t ₁ is 4 mm and the minimum thickness t ₂ is 2 mm.

  Thus, according to the third embodiment, as in the first embodiment, when a shock is applied to the frontal region or the occipital region, the first and second shock absorbers 340 and 341 are crushed and the shock is absorbed. To be done. At this time, the notches 362 and 363 provided in the first and second impact absorbers 340 and 341 cause the first and second impact absorbers 340 and 341 to respond to the impact on the frontal region and the occipital region. This better absorbs shock, as it collapses in a more desirable manner. Then, the shock (stress) is better dispersed by the stress buffering section 360 provided with the stress buffering convex section 365. Therefore, the stress concentration on the first and second shock absorbers 340 and 341, and further on the frontal region or the occipital region is relieved.

  Next, with reference to FIGS. 31 to 33, Tests 1 to 3 performed on the present example and the comparative example will be described. FIG. 31 is a table showing impact absorbency measured for the impact absorbers according to the present example and the comparative example without the stress buffer portion, and corresponds to test 1. FIG. 32 is a table showing the impact absorbency and stress concentration avoidance of the impact absorbers according to the present example and the comparative example, and corresponds to test 2. FIG. 33 is a table showing the impact absorbability of the first and second impact absorbers according to this example, which corresponds to test 3.

  (Test 1) With respect to the shock absorbers according to Examples 1 and 2 and the first to third comparative examples, a test for confirming the shock absorbability due to the structure of the shock absorber was conducted. Five types of shock absorbers having different structures were prepared as test samples. As shown in FIG. 31, the first to third comparative examples are shock absorbers 240A, 240B and 240C which are modified examples of the shock absorber 140 according to the second embodiment. The first embodiment is a first shock absorber 340 having a pair of notches 362, and the second embodiment is a second shock absorber 341 having a notch 363. In addition, since this test is a measurement test of the impact absorbability due to the structure itself of the impact absorber, the test was performed without providing the stress buffer portion.

  (Test method) Based on the standard for protective caps of the Ministry of Health, Labor and Welfare, a shock absorbing performance test of protective caps for protecting the head from the impact of a fall was conducted. First, as a pretreatment for the test, a pretreatment (high temperature treatment) of leaving the protective cap 1 equipped with a protective pad 3 having a shock absorber in a high temperature environment of about 50 ° C. for 2 hours and about −10 ° C. The pretreatment (low temperature treatment) of leaving it in the low temperature environment for 2 hours was performed. Then, the impact value in the frontal region and the impact value in the occipital region of the protective cap 1 after each pretreatment were measured in order. First, a human head model is installed on the load cell of a shock absorbing tester for a protective cap so that the center line is inclined at 30 degrees with respect to the horizontal. The protective cap 1 was put on the head. Then, a flat striker weighing 5 kg was allowed to fall freely from a height of 1 m toward the protective cap 1, and the impact value received by the human head model was measured. Next, the protective cap 1 was attached to the head model so that the impact point was located on the occipital region of the protective cap 1, and the maximum impact value received by the head model was measured in the same manner. The result is shown in FIG.

  (Test Results) In the above-described impact absorption performance test, it is specified that the impact value (impact load) transmitted to the human head model must be 9.81 kN or less. Therefore, with 9.81 kN as the reference value, in the table of FIG. 31, those in which the difference between the reference value and the maximum impact value is -0.1 to -0.9 kN are "▲", -1.0 to. The value of −1.9 kN is shown as “Δ”, the value of −2.0 to −2.9 kN is shown as “◯”, and the value of −3.0 kN or less is shown as “⊚”.

  Looking at the test results of the frontal region, after the high temperature treatment, the second comparative example and the present Examples 1 and 2 show “⊚”, and the maximum impact value is relatively low, but after the low temperature treatment, The comparative example shows “Δ”, and the maximum impact value is higher than those of Examples 1 and 2 showing “◯”. As described above, in the frontal region, it was found that the maximum impact value of the present Examples 1 and 2 having the notches 362 and 363 was relatively low as a whole. Next, looking at the test results of the occipital region, after the high temperature treatment, all of the first to third comparative examples and the present Examples 1 and 2 show "⊚", and there is almost no difference in the impact absorbability. After the low temperature treatment, only the present Examples 1 and 2 show “⊚”, and the maximum impact value is relatively lower than that of the first to third comparative examples. As described above, the impact absorbers 340 and 341 having the notches 362 and 363 according to the first and second embodiments are provided on both the frontal region side and the occipital region side in both cases after the high temperature treatment and the low temperature treatment. It was confirmed that the maximum impact value was lower. From the above, it was found that the shock absorbing properties are improved by providing the notches 362 and 363 in the shock absorbers 340 and 341.

(Test 2) Next, it is useful to provide the stress absorbers 340 and 341 with the stress buffering portion 360, and the avoidance of stress concentration due to the hardness of the stress buffering portion 360 and the shape of the stress buffering portion 360, and thus the thickness. A test was carried out to confirm the shock absorbing property. As a test sample, three types of shock absorbers having the same shape as the first shock absorber 340 but different stress buffers were prepared. The fourth comparative example is a shock absorber having no stress buffer portion on the back surface. The fifth comparative example is a shock absorber including a stress buffering portion having a uniform thickness. That is, the stress buffering portion of the fifth comparative example is not provided with the stress buffering convex portion 365. As the present embodiment, the first shock absorber 340 including the stress buffering portion 360 having the stress buffering convex portion 365 is used. In this test, the thickness of the stress buffer portion of the fifth comparative example is 2 mm, and the maximum thickness t ₂ of the stress buffer portion 360 of the present example is 4 mm. Further, with respect to the fifth comparative example and this example, shock absorbers each having four types of stress buffer portions formed of an elastomer having a hardness of 50 to 80 when measured with a durometer were prepared.

  (Test method) As a pretreatment for the test, the impact absorber was subjected to high-temperature and low-temperature pretreatment in the same manner as in Test 1, and the impact absorber that had undergone the pretreatment was tested under the following conditions. A flat plate was placed on a load cell in an impact tester for a protective cap, a pressure measuring film (pressure sensitive paper) was placed on the plate, and the shock absorber was placed flat on the pressure measuring film. Then, a flat striker having a weight of 5 kg was allowed to fall freely from a height of 1 m to the shock absorber, and the maximum impact value and the stress distribution received by the flat striker were confirmed. The result is shown in FIG.

  (Test Results) In the table of FIG. 32, the maximum impact value in the fourth comparative example having no stress buffering portion was used as a reference value, and the difference between the reference value and the maximum impact value was -0.1 to -0.4 kN. Is indicated by "Δ", -0.5 kN to -1.0 kN is indicated by "◯", and -1.1 kN or less is indicated by "⊚". Regarding the time (ms) until the maximum impact value is reached, the arrival time in the fourth comparative example is used as the reference time, and the difference between the reference time and the arrival time is 0 ms or less is “x”, +0. Those that are 10 to +0.19 ms are "▲", those that are +0.20 to +0.29 ms are "△", those that are +0.30 to +0.39 ms are "○", those that are +0.40 ms or more. Are shown as “⊚”. In the illustrated pressure measurement film, the upper side of the figure is the leg portion 36 side.

  Regarding the stress concentration avoidance property, referring to the pressure measurement film, in the fourth comparative example not including the stress buffering portion, the shape of the D-shaped projection in the plan view of the shock absorber is clearly shown in the pressure measurement film. Therefore, it is understood that the stress is concentrated on the outer wall portion and the inner wall portion of the protrusion, and the stress concentration is not relaxed. On the other hand, in the fifth comparative example including the stress buffering portion and the present embodiment, the collision marks of the protrusions 355 and 358 appearing on the pressure measurement film are relatively thin and extend over a wider range. Can be seen. Therefore, it can be seen that the shock absorbers 340 of the fifth comparative example and the present embodiment have less stress concentration than the shock absorbers of the fourth comparative example. Next, regarding the impact absorbability, in the fifth comparative example and the present example, the maximum impact value is lower than that of the fourth comparative example in any hardness. In addition, in the fifth comparative example and this example, the time required to reach the maximum impact value is longer than that in the fourth comparative example. From this, it can be seen that the stress buffering portion contributes to the improvement of shock absorption. From the above, it has been confirmed that the stress concentration avoiding property and the shock absorbing property are improved by providing the stress absorbing portion in the shock absorbing body.

  Next, with respect to the fifth comparative example and the present example, the impact absorption property and the stress concentration avoidance property due to the hardness of the elastomer used for the stress buffering section 360 will be examined. Regarding the impact absorbency, in the fifth comparative example, “Δ” is shown in all the hardnesses after the high temperature treatment, and “◯” is shown in all the hardnesses after the low temperature treatment. Therefore, in the fifth comparative example, it was found that the impact absorption was hardly affected by the difference in hardness of the elastomers. On the other hand, in this example, after the high temperature treatment, all the hardnesses show "○", and after the low temperature treatment, all the hardness show "◎". Therefore, also in this example, it was found that the impact absorption was hardly affected by the difference in hardness of the elastomers. On the other hand, with respect to the stress concentration avoidance property, in the fifth comparative example and the present example, the protrusions appearing on the pressure measurement film as the hardness of the elastomer decreases in both cases after the high temperature treatment and after the low temperature treatment. It was confirmed that the collision marks of the parts 355 and 358 were relatively thin and spread over a wider range. From the above, it was confirmed that in the hardness range of 50 to 80, the lower the hardness of the elastomer, the higher the stress concentration avoidability.

  Finally, with respect to the fifth comparative example and the present example, the impact absorbability due to the shape of the stress buffering portion and thus the thickness will be examined. Comparing the fifth comparative example with the present example, after the high temperature treatment, the fifth comparative example shows all “Δ”, whereas the present example shows all “◯”. Further, after the low temperature treatment, all of the fifth comparative examples show "○", whereas all of the present examples show "○". As described above, it was confirmed that the maximum impact value was lower in this example both after the high temperature treatment and after the low temperature treatment. From the above, it was found that the shock absorbing property is improved by providing the stress buffering convex portion 365 on the stress buffering portion 360.

  (Test 3) A protective pad 3 is formed by providing the shock absorbers 340 and 341, which had high shock absorption in Test 1, with the stress buffering portions 360, which had high stress concentration avoidance and high shock absorption in Test 2. It was mounted on the and was subjected to a shock absorption performance test of the protective cap for protecting the head from the impact due to the fall, which is the standard of the protective cap of the Ministry of Health, Labor and Welfare. The first embodiment, which is a test sample, is the protective pad 3 provided with the first shock absorber 340 on the forehead and occipital region, and the second embodiment includes the second shock absorber 341 on the forehead and occipital region. It is a protective pad 3 provided on the back of the head. Each of the first and second shock absorbers 340 and 341 is made of an elastomer having a hardness of 60 and includes a stress buffering portion 360 having a stress buffering convex portion 365. Therefore, the first embodiment and the second embodiment are different only in the positions of the notches 362 and 363 provided in the inner wall portions 355b and 358b of the protrusions 355 and 358.

  (Test method) As the pretreatment of the test, similar to the test 1, the protective cap 1 equipped with the protective pad 3 of the present Examples 1 and 2 was subjected to high temperature and low temperature pretreatments, respectively. After the pretreatment, install the man head model on the load cell of the shock absorption tester for the protective cap so that the center line is inclined at 30 degrees to the horizontal. The protective cap 1 was attached so as to be positioned on the frontal region of the. Then, a flat striker weighing 5 kg was allowed to fall freely from a height of 1 m toward the protective cap 1, and the impact value received by the human head model was measured. Next, the protective cap 1 was attached to the human head model so that the impact point was located on the occipital region of the protective cap 1, and the impact value was similarly measured. The result is shown in FIG.

  (Test Results) As described above, the shock absorption performance test stipulates that the shock value transmitted to the human head model must be 9.81 kN or less. Therefore, with 9.81 kN as the reference value, in the table of FIG. 33, when the difference between the reference value and the maximum impact value is -2.1 to -2.5 kN, "▲", -2.6 to. Those having a value of −3.0 kN are shown as “Δ”, those having a value of −3.1 to −3.5 kN are shown as “◯”, and those having a value of −3.6 kN or less are shown as “⊚”. In Examples 1 and 2, the maximum impact value was significantly lower than the above reference value, and it was confirmed that high impact absorbency was obtained. Looking at the test results of the forehead, in Example 1, “◎” is shown after the high temperature treatment and “Δ” is shown after the low temperature treatment, whereas in Example 2, after the high temperature treatment. Indicates “◯” and indicates “▲” after low temperature treatment. From this, it was confirmed that in the frontal region, the maximum impact value of the present Example 1 was lower than that of the present Example 2 both in the case after the high temperature treatment and after the low temperature treatment, and therefore, the impact absorbability was higher. . Next, looking at the test results of the occipital region, after the high temperature treatment, both of the present Example 1 and the present Example 2 show “◯”. On the other hand, after the low temperature treatment, Example 1 shows “◯”, whereas Example 2 shows “⊚”. From this, it was confirmed that in the occipital region, the maximum impact value of the second embodiment is lower than that of the first embodiment, and therefore the impact absorbability is higher. From the above, it was found that it is useful to use the first shock absorber 340 for the forehead and the second shock absorber 341 for the occipital region. In other words, it is useful to provide the front wall impact absorber with a pair of notches 362 facing each other in the left-right direction on the inner wall portion 358b of the second protrusion 358. Found that it is beneficial to provide the notch 363 in the inner wall portion 355b of the first protrusion 355 located on the leg portion 37 side.

  As described above, according to the first and second shock absorbers 340 and 341 including the stress buffering portion 360 having the stress buffering convex portion 365 and the notches 362 and 363 according to the third embodiment, the forehead Alternatively, the impact applied to the back of the head is better absorbed and dispersed. Therefore, stress concentration on the frontal region or the occipital region is reduced.

  (Modification) A modification of the front head impact absorber according to the third embodiment will be described with reference to FIGS. FIG. 34 is a bottom view of the protection pad 3 including the shock absorber 440 according to this modification. The protective pad 3 includes a forehead impact absorber 440 provided at the lower end of the forehead leg portion 36 and an occipital region impact absorber 341 provided at the lower end of the occipital region leg portion 37. Have It should be noted that this modification relates to the shock absorber 440 for the forehead, and the shock absorber 340 for the occipital region is the same as that of the third embodiment.

  As shown in FIG. 35, on the back surface of the shock absorber 440 for the forehead, a stress buffering portion 460 having a cross shape is provided over the entire back surface of the base portion 353. The stress buffering portion 460 has one stress buffering convex portion 465 protruding in a direction away from the base portion 353. The stress buffering convex portion 465 extends in four directions of the stress buffering portion 460 in the left-right direction and the front-back direction. Specifically, in the left-right direction, the stress buffering convex portion 465 extends to the vicinity of both end portions of the stress buffering portion 460. In the front-rear direction, the stress buffering convex portion 465 extends to the vicinity of the upper end portion 460a on the leg portion 36 side, while on the lower end portion 460b side, extends to a position slightly closer to the lower end portion 460b from the center. . In addition, the stress buffering convex portion 465 extends over most of the width W of the cross-shaped portion extending in the front-rear direction and the portion extending in the left-right direction.

As shown in FIG. 36, the stress buffering convex portion 465 has a flat top portion. Therefore, when the protective cap 1 is worn, the stress buffering convex portion 465 comes into surface contact with the front head of the wearer. Furthermore, the stress buffer 460 has a maximum thickness t ₃ and a minimum thickness t ₂ . The maximum thickness t ₃ is the height of the perpendicular line drawn from the top of the stress buffering convex portion 465 to the back surface of the base 353, and is 4 mm in this modification. The minimum thickness t ₂ is the thickness of the stress buffering portion 460 at a portion where the stress buffering convex portion 465 is not provided, and is 2 mm in this modification.

  As described above, the shock absorber 440 having the stress buffering portion 460 provided with the stress buffering convex portion 465 according to the present modification also absorbs and disperses the impact applied to the forehead better, and Stress concentration on the part is relieved. Further, according to the shock absorber 440 of the present modification, the same stress concentration avoidance and shock absorbability as those of the shock absorber of the third embodiment can be obtained, and the shock absorber 440 having a flat top portion. This makes it possible to obtain a better fit on the frontal region side when the cap body is worn.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications can be made. The protective pad 3 and the hammock 10 that are separately formed may be formed of the same synthetic resin material or different synthetic resin materials. Further, in the above embodiment, the protective pad 3 and the hammock 10 are configured as separate members, but the protective pad 3 and the hammock 10 may be integrally formed.

  Furthermore, in the above-described embodiment, the shock absorber 40 and the stress cushioning portion 60 have a rectangular shape, and the shock absorbers 140, 340, 341 and the stress cushioning portions 160, 360 have a substantially cross shape. The shape of the stress buffering portion is not limited to this, and may be any shape. Further, in the first and second embodiments, the same shock absorbers 40 and 140 are used as the shock absorbers for the frontal region and the occipital region, but different shock absorbers may be used for the frontal region and the occipital region. You may use.

  The shape and the number of the stress buffering convex portions 365 and 465 are not limited to the above-described embodiments and modified examples, and may be other shapes and numbers. Further, in the third embodiment, in the second impact absorber 341 for the back of the head, only the inner wall portion 355b of the first protrusion 355 located on the leg 37 side among the pair of first protrusions 355. Although the cutout 363 is formed in the cutout 363, the cutout 363 may be formed in the inner wall portion 355b of the first protrusion 355 on the lower end side so as to face the cutout 363.

  Further, in the above embodiment, the protrusion 32 and the impact absorbing protrusions 45, 48, 51, 159a, 159b each have a circular cross-sectional shape, but the present invention is not limited to this, and for example, It may have another cross-sectional shape such as a rectangle or a triangle.

  Further, the method of forming the protective pad 3 and the stress buffering portion 60 is not limited to the above-mentioned forming method. For example, in the case of insert molding, after the protective pad 3 including the impact absorber 40 made of polyethylene is molded in advance, the molded protective pad 3 may be set in a mold for elastomer to mold the elastomer, After molding the elastomer in advance, the pad 3 may be molded by setting the elastomer in a mold for the protective pad 3.

1 Protective cap 2 Hat body 3 Protective pad 10 Hammock 11 Headband 40, 140, 340, 341, 440 Shock absorber 60, 160, 360, 460 Stress buffer 36, 37, 38, 39 Leg part of protective pad 21, 22, 23, 24 Hammock leg 362, 363 Notch 365, 465 Stress buffering convex

Claims (8)

A cap that covers the wearer's head,
A synthetic resin protective pad detachably attached to the inside of the cap body,
A hammock made of synthetic resin detachably attached to the cap body inside the protective pad,
A synthetic resin headband detachably attached to the lower end of the hammock,
Equipped with
The protective pad is provided with shock absorbers protruding from the inner surface of the cap body at positions corresponding to the frontal region and the back region of the head, and a stress buffer made of synthetic resin having elasticity is provided on the back surface of the shock absorbers. The protective cap characterized by being.   The protective cap according to claim 1, wherein the synthetic resin material of the protective pad, the hammock, and the headband is different from the synthetic resin material of the stress buffer section.   The protective cap according to claim 1 or 2, wherein the synthetic resin having elasticity is a thermoplastic elastomer.   The protection pad has a first leg portion extending from the crown portion side to the frontal region side, and a second leg portion extending from the crown portion side to the occipital region side, and in the first leg portion and the second leg portion, The protective cap according to any one of claims 1 to 3, wherein shock absorbers are provided at positions corresponding to the frontal region and the back region of the wearer, respectively.   The hammock has a plurality of legs that extend radially from the top of the head, and the first leg of the protection pad is provided between a pair of legs located on the frontal side of the plurality of legs. The protective cap according to any one of claims 1 to 4, wherein the second leg portion of the protective pad is located between a pair of leg portions located on the occipital region side.   The protective cap according to claim 1, wherein the protective pad is formed integrally with or separately from the hammock. The shock absorber has a base portion, a pair of first wall portions protruding from the base portion along a first direction of the base portion, and the first direction substantially between the pair of wall portions. A pair of second wall portions protruding from the base portion along a second direction orthogonal to each other,
7. The protective cap according to claim 1, wherein notches are provided in both of the pair of first wall portions and at least one of the pair of second wall portions.   The protective cap according to any one of claims 1 to 7, wherein the stress buffering part has a stress buffering convex part projecting at least partially toward the frontal region and the occipital region.