Abstract: A heat exchanger in which an end portion of a heat exchange element is appropriately joined to an insertion hole of a header. The heat exchanger includes a heat exchange element extending in a first direction and a header to which the heat exchange element is connected. The heat exchange element includes at least one heat transfer tube extending in the first direction and a fin provided on part of an edge portion of the at least one heat transfer tube in a second direction crossing orthogonally with the first direction. An end portion in the first direction of the heat exchange element includes an insertion part being inserted into an interior of the header, an abutment part abutting the header in a part other than the insertion part, and a spaced-apart part being spaced apart from the header in a part other than the insertion part.

Abstract: A frame assembly body includes a connected section in which one ends of first and second frame materials, each of which has plural bent sections and plural surfaces, are joined perpendicularly. The connected section has: a projected piece locking section in which a slit-shaped fitting hole, a notch, or a recessed section formed in the second frame material is fitted to a projected piece provided in the first frame material; and a slit fitted section in which a slit-shaped notch formed in the second frame material is fitted to a fitting slit formed in a manner to notch the first frame material.

Abstract: A frame assembly body includes a connected section in which one ends of first and second frame materials, each of which has plural bent sections and plural surfaces, are joined perpendicularly. The connected section has: a projected piece locking section in which a slit-shaped fitting hole, a notch, or a recessed section formed in the second frame material is fitted to a projected piece provided in the first frame material; and a slit fitted section in which a slit-shaped notch formed in the second frame material is fitted to a fitting slit formed in a manner to notch the first frame material.

Abstract: A work tank of an electric discharge machining device can manually move up and down, open and close, and lock and unlock a door without using any mechanical components. The work tank includes: a box-shaped tank body having an open front surface and an openable and closable door; a pair of handle bars that are placed right and left of the tank body; a handle that is installed between front end parts of the pair of handle bars; a pair of door stays that are placed at right and left of the tank body; a guide rail that moves up and down the door stay hung from the handle bar; a load receiving unit that supports a load of the door stay; and a stopper that restricts downward rotation and a frontward movement of the handle bar at a predetermined rotation position.

Abstract: A work tank of an electric discharge machining device can manually move up and down, open and close, and lock and unlock a door without using any mechanical components. The work tank includes: a box-shaped tank body having an open front surface and an openable and closable door; a pair of handle bars that are placed right and left of the tank body; a handle that is installed between front end parts of the pair of handle bars; a pair of door stays that are placed at right and left of the tank body; a guide rail that moves up and down the door stay hung from the handle bar; a load receiving unit that supports a load of the door stay; and a stopper that restricts downward rotation and a frontward movement of the handle bar at a predetermined rotation position.

Abstract: A self tapping bolt which fastens a mounting member and a receiving member while the bolt cuts internal threads on an inner surface of a tap drill hole prepared in the receiving member. The bolt includes at least one groove formed near an end of a threaded portion of the bolt and a blade for cutting the internal threads. The bolt includes the feature of the blade being formed only on a rear end surface of the groove relative to a rotational direction of the bolt which is screwed into the tap drill hole.

Abstract: A self tapping bolt is provided, which fastens a mounting member and a receiving member while the bolt cuts internal threads on an inner surface of a tap drill hole prepared in the receiving member. The bolt includes at least one groove formed near an end of a threaded portion of the bolt and a blade for cutting the internal threads. The bolt has the features that the blade is formed only on a rear end surface of the groove relative to a rotational direction of the bolt which is screwed into the tap drill hole.