Vehicular impact-absorbing member

1. A vehicular impact-absorbing member comprising a wood member, a pair of restraint members having a hardness greater than the wood member, and connecting portions connecting the restraint members to each other so as to combine the restraint members with the wood member, and configured to absorb an impact load applied to a vehicle using deformability of the wood member,

wherein the wood member is positioned such that an axis direction of annual rings thereof is substantially aligned with a direction of the impact load, and has an input end portion to which the impact load is applied and a base end portion positioned opposite to the input end portion,

wherein the pair of constraint members are oppositely positioned with the wood member sandwiched therebetween and with covering a portion between the input end portion and the base end portion of the wood member when the impact-absorbing member is viewed from a side facing the input end portion of the wood member, and are positioned,

wherein the connecting portions are positioned so as to bridge the pair of restraint members when the impact-absorbing member is viewed from the side facing the input end portion of the wood member, and include a pair of input end-side connecting portions that are positioned relatively adjacent to the input end portion of the wood member and a pair of base end-side connecting portions that are positioned relatively away from the input end portion of the wood member than the input end-side connecting portions,

wherein the pair of input end-side connecting portions are spaced in a direction perpendicular to a bridging direction of the connecting portions, and

wherein the pair of base end-side connecting portions are spaced in the direction perpendicular to the bridging direction of the connecting portions.

2. The vehicular impact-absorbing member as defined in claim 1 , wherein a distance between the pair of input end-side connecting portions is greater than a distance between the pair of base end-side connecting portions.

3. The vehicular impact-absorbing member as defined in claim 1 , wherein at least one of the pair of base end-side connecting portions is positioned between the pair of input end-side connecting portions when the impact-absorbing member is viewed from the side facing the input end portion of the wood member.

4. The vehicular impact-absorbing member as defined in claim 1 , wherein the pair of input end-side connecting portions and the pair of base end-side connecting portions bridge the pair of restraint members while penetrating the wood member sandwiched therebetween.

5. The vehicular impact-absorbing member as defined in claim 1 , wherein when the impact-absorbing member is attached to the vehicle, the base end portion of the wood member at least partly contacts a body of the vehicle.

6. The vehicular impact-absorbing member as defined in claim 1 , wherein the pair of restraint members are made of metallic materials.

7. A vehicular impact-absorbing member, comprising:

a wood member having a first pair of opposite surfaces perpendicular to an axis direction of annual rings thereof, a second pair of opposite surfaces parallel to the axis direction of the annual rings thereof, and a third pair of opposite surfaces parallel to the axis direction of the annual rings thereof;

a pair of restraint members respectively positioned on the second pair of opposite surfaces of the wood member; and

connecting members connecting the pair of restraint members to each other with the wood member sandwiched between the pair of restraint members,

wherein the connecting members are configured to connect the pair of restraint members to each other with the third pair of opposite surfaces of the wood member exposed.

8. The vehicular impact-absorbing member as defined in claim 7 , wherein the connecting members comprise threaded rods that are configured to connect the pair of restraint members with penetrating the wood member.

9. The vehicular impact-absorbing member as defined in claim 7 , wherein the connecting members comprise angled clamp members that are configured to clamp the pair of restraint members.

10. The vehicular impact-absorbing member as defined in claim 7 , wherein the connecting members comprise frame-shaped members that are configured to encircle the pair of restraint members.

11. The vehicular impact-absorbing member as defined in claim 7 , wherein the connecting members include a first pair of connecting members that are positioned along one of the first pair of opposite surfaces of the wood member with spaced at a distance and a second pair of connecting members that are positioned along the other of the first pair of opposite surfaces of the wood member with spaced at a distance.

12. The vehicular impact-absorbing member as defined in claim 11 , wherein the distance between the first pair of connecting members is greater than the distance between the second pair of connecting members.