A member joining method includes: a placement process of arranging a first member and a second member inserted into the first member so that a gap surrounding the second member is provided between the first member and the second member; a filling process of filling a molten resin into the gap and applying pressure to the resin so as to cause at least one member of the first member or the second member to undergo elastic deformation; and a pressure maintaining process of maintaining the pressure until the resin that has been filled into the gap has cured.

A refrigerant pipe that constitutes a refrigerant circuit of a refrigeration apparatus includes: a first pipe; and a second pipe. The first pipe includes: a first pipe body, made of stainless steel; and a first connection, made of a material different from stainless steel, disposed at an end of the first pipe body in a pipe axial direction of the first pipe body. The second pipe includes: a second pipe body, made of stainless steel; and a second connection, made of a material identical to the material of the first connection, disposed at an end of the second pipe body in a pipe axial direction of the second pipe body. The first connection is connected to the second connection.

A refrigerant pipe of a refrigeration apparatus includes: a first pipe, made of stainless steel, through which a refrigerant flows; a joint pipe, made of a material different from stainless steel, disposed on an outer peripheral surface of the first pipe; and a second pipe, having a diameter smaller than a diameter of the first pipe, connected to the outer peripheral surface of the first pipe via the joint pipe. A surface of the second pipe at which the second pipe is connected to the joint pipe is made of a material identical to the material of the joint pipe.

A refrigerant pipe that constitutes a refrigerant circuit of a refrigeration apparatus includes: a first pipe; and a second pipe. The first pipe includes a pipe body made of stainless steel; and a connection pipe, made of a material different from stainless steel, disposed at an end of the pipe body in a pipe axial direction. The connection pipe includes a protrusion protruding in the pipe axial direction from the end of the pipe body. The second pipe includes: a second-pipe large diameter portion, made of a material that is a same as the material of the connection pipe, disposed at an end in the pipe axial direction; a second-pipe small diameter portion having a smaller diameter than the second-pipe large diameter portion; and a step portion disposed between the second-pipe large diameter portion and the second-pipe small diameter portion.

The present invention discloses a compressor comprising: an outer pipe being connected from an outside to pass through the vessel; an inner pipe being closely inserted into the outer pipe; a compression mechanism including a suction hole formed of a blind hole and a suction valve in the suction hole. The suction valve includes a seal on a side facing an opening of the suction hole to seal an entire end of the inner pipe on a side facing the suction valve when the compressor stops.

The element joint is obtained by joining: a long pipe; a short pipe made of a quality of material having a strength equal to or higher than a strength of the long pipe; and a plate material made of a quality of material having a strength equal to or higher than a strength of the short pipe. In the element joint, at least one member of the long pipe and the short pipe includes a pipe-shaped portion, and the pipe-shaped portion of the one member is pipe-expanded and joined to the other member by press-fitting. The short pipe and the plate material are welded to each other.

The element joint is obtained by joining: a long pipe; a short pipe made of a quality of material having a strength equal to or higher than a strength of the long pipe; and a plate material made of a quality of material having a strength equal to or higher than a strength of the short pipe. In the element joint, at least one member of the long pipe and the short pipe includes a pipe-shaped portion, and the pipe-shaped portion of the one member is pipe-expanded and joined to the other member by press-fitting. The short pipe and the plate material are welded to each other.

This coupling device for a tubular member is provided with: a base stand for holding an inner member and an outer member in a state in which the outer member is disposed around the inner member; a plurality of pressing members that are supported by the base stand in a movable manner in the radial direction of the inner member and the outer member and have a protruding part on the tip thereof; a pressing member that make contact with the final end of the pressing member and that can press the pressing member radially inward; and a drive mechanism that drives any one among the base stand and the pressing member in a direction perpendicular to the movement direction of the pressing member so that the one member moves relative to the other. The inner member and the outer member are caulked and coupled by driving, by the drive mechanism, any one among the base stand and the pressing member and displacing the pressing member radially inward to thereby expand, radially inward, a portion of a peripheral wall of the outer member by the protruding part.

This coupling device for a tubular member is provided with: a base stand for holding an inner member and an outer member in a state in which the outer member is disposed around the inner member; a plurality of pressing members that are supported by the base stand in a movable manner in the radial direction of the inner member and the outer member and have a protruding part on the tip thereof; a pressing member that make contact with the final end of the pressing member and that can press the pressing member radially inward; and a drive mechanism that drives any one among the base stand and the pressing member in a direction perpendicular to the movement direction of the pressing member so that the one member moves relative to the other. The inner member and the outer member are caulked and coupled by driving, by the drive mechanism, any one among the base stand and the pressing member and displacing the pressing member radially inward to thereby expand, radially inward, a portion of a peripheral wall of the outer member by the protruding part.

Herein a tubular element (2) is disclosed. The tubular element comprises a first tubular portion (4) comprising a first metal or alloy and a second tubular portion (6) comprising a second metal or alloy. At least a portion of an interface (9) between the first and second tubular portions (4, 6) extends within a fixed diameter range along a longitudinal direction (L) of the tubular element. The second tubular portion (6) comprises a first end portion (8) arranged around the first tubular portion (4). The second tubular portion (6) comprises a sealing surface (10) extending circumferentially around the second tubular portion (6) at the first end portion (8).