Both diameter expansion and contraction control and fitting stabilization are achieved at the same time in a pipe end release-type pipe-forming apparatus having a non-inner periphery restriction structure. A driving part (10) provided in an apparatus frame (30) of a pipe-forming apparatus (3N) presses an unformed following strip portion (92) of the strip member (90). A reverse side guide portion (83) is engaged with a pipe end portion (91e) of a preceding spiral pipe portion (91) from a reverse side. A face side guide portion (82) is engaged with the pipe end portion (91e) from a face side. The face side guide portion (82) is shifted to the propulsion rear side beyond the reverse side guide portion (83). The following strip portion (92) is extruded from the driving part (10) toward an inter-guide clearance (84) between the reverse side guide portion (83) and the face side guide portion (82). Preferably, the driving part (10) is position-adjustably attached to the guide portions (83), (82) or the apparatus frame (30) via a position adjustment mechanism (31a).

A pipe-forming apparatus with which a spiral pipe can be formed using a simple configuration without an inner periphery restriction body. A driving part (10) of a pipe-forming apparatus (3) presses a following strip portion (92) toward a pipe end portion (91e) of a preceding spiral pipe portion (91) obliquely with respect to a machine-height direction HD. A pipe end guide is constrained in a machine-width direction WD with respect to the pipe end portion, and slidably engaged in a propelling longitudinal direction LD. A pressing force for the following strip portion provides a fitting force between the following strip portion and the pipe end portion, and a propelling force for forward propulsion. A pipe is formed in a state where a part other than a partial part at which the pipe-forming apparatus is provided in a circumferential direction of the pipe end portion is released from the pipe-forming apparatus.

A pipe-forming apparatus with which a spiral pipe can be formed using a simple configuration without an inner periphery restriction body. A driving part (10) of a pipe-forming apparatus (3) presses a following strip portion (92) toward a pipe end portion (91e) of a preceding spiral pipe portion (91) obliquely with respect to a machine-height direction HD. A pipe end guide is constrained in a machine-width direction WD with respect to the pipe end portion, and slidably engaged in a propelling longitudinal direction LD. A pressing force for the following strip portion provides a fitting force between the following strip portion and the pipe end portion, and a propelling force for forward propulsion. A pipe is formed in a state where a part other than a partial part at which the pipe-forming apparatus is provided in a circumferential direction of the pipe end portion is released from the pipe-forming apparatus.

The present invention provides a pipe-making apparatus and a pipe-making method capable of making a spiral pipe variably adjusting a diameter or a perimeter of the pipe without an inner periphery limiter. An edge 94 of a following strip portion 92 of a strip member 90 is fitted with a corresponding edge 93 of a preceding pipe portion 91 preceding by one turn by a pipe-making part 3a of a pipe-making apparatus 3, the following strip portion 92 following the preceding pipe portion 91 precedingly made into the spiral pipe, the following strip portion not yet made into the pipe. The pipe-making apparatus 3a is propelled along a spiral winding direction accompanying the fitting. A position 9q of the fitting is variably adjusted by a fitting height adjuster such as an operating lever 30 in a machine height direction HD or a pipe inside-outside direction VD.

The present invention provides a pipe-making apparatus and a pipe-making method capable of making a spiral pipe variably adjusting a diameter or a perimeter of the pipe without an inner periphery limiter. An edge 94 of a following strip portion 92 of a strip member 90 is fitted with a corresponding edge 93 of a preceding pipe portion 91 preceding by one turn by a pipe-making part 3a of a pipe-making apparatus 3, the following strip portion 92 following the preceding pipe portion 91 precedingly made into the spiral pipe, the following strip portion not yet made into the pipe. The pipe-making apparatus 3a is propelled along a spiral winding direction accompanying the fitting. A position 9q of the fitting is variably adjusted by a fitting height adjuster such as an operating lever 30 in a machine height direction HD or a pipe inside-outside direction VD.

It is possible to prevent a tip portion of a guide portion in a spiral pipe-forming apparatus allowing an inner periphery restriction body to be omitted from colliding a peripheral surface portion of a non-circular existing pipe. A non-circular guide portion (73) is provided so as to be rotatable with respect to an apparatus frame (3a) around a rotary axis (32). The guide portion (73) is applied to a peripheral surface of a preceding spiral pipe portion (91). An acting portion (41) acts such that the guide portion (73) follows the peripheral surface of the existing pipe (1).

It is possible to prevent a tip portion of a guide portion in a spiral pipe-forming apparatus allowing an inner periphery restriction body to be omitted from colliding a peripheral surface portion of a non-circular existing pipe. A non-circular guide portion (73) is provided so as to be rotatable with respect to an apparatus frame (3a) around a rotary axis (32). The guide portion (73) is applied to a peripheral surface of a preceding spiral pipe portion (91). An acting portion (41) acts such that the guide portion (73) follows the peripheral surface of the existing pipe (1).

Both diameter expansion and contraction control and fitting stabilization are achieved at the same time in a pipe end release-type pipe-forming apparatus having a non-inner periphery restriction structure. A driving part (10) provided in an apparatus frame (30) of a pipe-forming apparatus (3N) presses an unformed following strip portion (92) of the strip member (90). A reverse side guide portion (83) is engaged with a pipe end portion (91e) of a preceding spiral pipe portion (91) from a reverse side. A face side guide portion (82) is engaged with the pipe end portion (91e) from a face side. The face side guide portion (82) is shifted to the propulsion rear side beyond the reverse side guide portion (83). The following strip portion (92) is extruded from the driving part (10) toward an inter-guide clearance (84) between the reverse side guide portion (83) and the face side guide portion (82). Preferably, the driving part (10) is position-adjustably attached to the guide portions (83), (82) or the apparatus frame (30) via a position adjustment mechanism (31a).

Both diameter expansion and contraction control and fitting stabilization are achieved at the same time in a pipe end release-type pipe-forming apparatus having a non-inner periphery restriction structure. A driving part (10) provided in an apparatus frame (30) of a pipe-forming apparatus (3N) presses an unformed following strip portion (92) of the strip member (90). A reverse side guide portion (83) is engaged with a pipe end portion (91e) of a preceding spiral pipe portion (91) from a reverse side. A face side guide portion (82) is engaged with the pipe end portion (91e) from a face side. The face side guide portion (82) is shifted to the propulsion rear side beyond the reverse side guide portion (83). The following strip portion (92) is extruded from the driving part (10) toward an inter-guide clearance (84) between the reverse side guide portion (83) and the face side guide portion (82). Preferably, the driving part (10) is position-adjustably attached to the guide portions (83), (82) or the apparatus frame (30) via a position adjustment mechanism (31a).

A spiral pipe (9) is formed by joining edges of adjacent turns of a strip member (90) while helically winding the strip member using a pipe-making apparatus. A propulsive reaction force for moving in a winding direction of the strip member is imparted to a following strip portion (92) or a preceding spiral pipe portion (91) of the strip member by a propulsive reaction force imparting portion of the pipe-making apparatus. The following strip portion follows a preceding spiral pipe portion that has already been made into a pipe. A resisting force in a direction opposite to the propulsive reaction force is imparted to the strip member along the winding direction by a friction between a resisting force imparting portion and the strip member generated while the strip member is moved forward. In this arrangement, a diameter limiting frame can be omitted, and thereby, the pipe-making apparatus can be downsized.