Joint structure
This invention provides a joint structure in which three-dimensionally intersecting joint surfaces of two members can be brought into close contact with each other. The joint structure comprises: a casing 2 having a first main joint surface 24 , and a first sub-joint surface 25 that three-dimensionally intersects the first main joint surface 24 ; a cover 3 having a second main joint surface 34 facing the first main joint surface 24 and a second sub-joint surface 35 facing the first sub-joint surface 25 ; a guide portion 4 that gradually reduces the facing distance between the first sub-joint surface 25 and the second sub-joint surface 35 as the facing distance between the first main joint surface 24 and the second main joint surface 34 is reduced, and when the second main joint surface 34 is joined to the first main joint surface 24 , allows the second sub-joining surface 35 to be joined to the first sub-joining surface 25 , and positions the cover 3 with respect to the casing 2 ; and a screw 5 that fastens the joined first main joint surface 24 and second main joint surface 34 to each other.
1 . A joint structure comprising:
an articulated robot arm having an opening having a first peripheral wall comprising a first main joint surface, and a shoulder surface traversing the opening comprising a first sub joint surface that three-dimensionally intersects with the first main joint surface;
a cover for the robot arm, the cover having a second peripheral wall corresponding to the first peripheral wall, the second peripheral wall comprising a second main joint surface opposite to the first main joint surface, and an edge surface comprising a second sub joint surface opposite to the first sub joint surface;
a guide configured to gradually shorten a distance between the first sub joint surface and the second sub joint surface that are opposite to each other as a distance between the first main joint surface and the second main joint surface that are opposite to each other decreases, the guide enabling joining of the second sub joint surface to the first sub joint surface in a state of surface contact, upon joining of the second main joint surface to the first main joint surface in a state of surface contact, the guide being further configured to position the cover relative to the robot arm; and
a fastening member configured to fasten the first main joint surface and the second main joint surface, which have been joined to each other, to each other,
wherein the guide causes the cover to move at least in a direction parallel to the first main joint surface;
wherein the guide comprises a guide projection provided on one of the first main joint surface and the second main joint surface, and a guide hole formed in the other of the first main joint surface and the second main joint surface, and adapted to receive the guide projection fitted therein; and
wherein the guide hole and guide projection each have an inclined guide surface angled toward a respective one of the first and second sub joint surfaces that causes the cover to move toward the first sub joint surface as the guide projection is inserted deeper into the guide hole.
2 . The joint structure according to claim 1 , wherein the guide comprises:
a first guide hole formed in the first main joint surface; and
a second guide hole formed in the second main joint surface;
wherein the guide projection is adapted to be fitted in both the first guide hole and the second guide hole, and
wherein the first guide hole and the second guide hole each extend in a direction that allows the cover to move toward the first sub joint surface as the guide projection is inserted deeper into the guide holes.
3 . The joint structure according to claim 1 , wherein a sealing member is interposed between the first main joint surface and the second main joint surface and between the first sub joint surface and the second sub joint surface.
4 . The joint structure according to claim 1 , wherein the guide projection is integrally formed with the cover or the robot arm.