Synthetic resin pipe manufacturing apparatus
View Patent ↗The present disclosure relates to a synthetic resin pipe manufacturing apparatus including: an extruder configured to extrude a synthetic resin pipe through a blow molding portion; an air fitting formed in a cylindrical shape having the same inner diameter as the synthetic resin pipe and formed in front of an air supply pipe, which is formed inside the extruder; an air discharge plate disposed in front of the air ejection pipe and having a plurality of air discharge holes perforated in a disc to discharge hot air, generated as air ejected through the air holes cools the inner surface of the synthetic resin pipe, to the outside; the air supply pipe disposed behind the air fitting and having a plurality of air holes perforated therein; and a rotation driver configured to transmit rotation power to the air supply pipe.
1 . A synthetic resin pipe manufacturing apparatus comprising:
an extruder ( 20 ) configured to, while slowly rotating a resin supplied from a raw material supply device ( 10 ), extrude a synthetic resin pipe ( 50 ) through a blow molding portion ( 21 ) such that a hollow portion ( 51 ) is formed in a spiral shape in a longitudinal direction;
an air supply pipe ( 40 ) provided inside the extruder ( 20 );
an air fitting ( 41 ) having a cylindrical shape with the same inner diameter as the synthetic resin pipe ( 50 ), the air fitting ( 41 ) being disposed in front of the air supply pipe ( 40 ) to support an inner surface ( 52 ) of the synthetic resin pipe ( 50 ) as the synthetic resin pipe ( 50 ) is extruded from the extruder ( 20 ) and introduced into a cooler ( 30 a ) of a dice ( 30 );
an air ejection pipe ( 42 ) disposed in front of the air fitting ( 41 ) and having a plurality of air holes ( 42 ′) formed therein to cool the inner surface of the synthetic resin pipe ( 50 );
an air discharge plate ( 43 ) disposed in front of the air ejection pipe ( 42 ) and having a plurality of air discharge holes ( 43 ′) perforated through the air discharge plate ( 43 ) to discharge to the outside hot air generated by cooling the inner surface of the synthetic resin pipe ( 50 ) with air ejected through the air holes ( 42 ′),
wherein the air supply pipe ( 40 ) is disposed behind the air fitting ( 41 ) and has a plurality of air holes ( 44 ) formed therein to discharge air and cool the hollow portion ( 51 ) of the synthetic resin pipe ( 50 ) while the synthetic resin pipe ( 50 ) is being extruded from the extruder ( 20 ); and
a rotation driver ( 90 ) configured to transmit rotation power to the air supply pipe ( 40 ),
wherein the rotation driver ( 90 ) rotates the air supply pipe ( 40 ) and thereby rotates the air fitting ( 41 ), the air ejection pipe ( 42 ), and the air discharge plate ( 43 ) that are integrally formed with the air supply pipe ( 40 ),
wherein a plurality of recesses ( 431 ) recessed at equal intervals along a circumference of an outer circumferential surface of the air discharge plate ( 43 ), each recess ( 431 ) having a semicircular groove structure and allowing hot air to pass between the recess ( 431 ) and the inner surface 52 ) of the synthetic resin pipe ( 50 ) so that the hot air is discharged to the outside in conjunction with the air discharge holes ( 43 ′),
wherein the synthetic resin pipe manufacturing apparatus further comprises an ultrasonic inspection unit ( 400 A) and a cooling zone ( 30 c ), the ultrasonic inspection unit ( 400 A) being configured to perform a surface inspection of the synthetic resin pipe ( 50 ) as the synthetic resin pipe ( 50 ) passes through the air discharge plate ( 43 ), and the cooling zone ( 30 c ) having a larger diameter than the synthetic resin pipe ( 50 ) and being formed behind the air discharge plate ( 43 ) in the cooler ( 30 a ) of the dice ( 30 ).
2 . The synthetic resin pipe manufacturing apparatus of claim 1 , wherein the ultrasonic inspection unit ( 400 A) includes:
an annular support member ( 400 A 1 ) disposed in the cooling zone ( 30 c ) in a configuration surrounding the synthetic resin pipe ( 50 );
a plurality of ultrasonic sensor parts ( 400 A 2 ) radially provided on an inner circumferential surface of the support member ( 400 A 1 ); and
two or more relay parts ( 400 A 3 ) radially disposed on an outer circumferential surface of the support member ( 400 A 1 ) to connect the support member ( 400 A 1 ) to an inner circumferential surface of the cooling zone ( 30 c ) such that the support member ( 400 A 1 ) is spaced apart from the inner circumferential surface.
3 . The synthetic resin pipe manufacturing apparatus of claim 2 , further comprising a coolant circulation unit ( 100 ) that includes a first tank ( 101 ) which is empty, a second tank ( 102 ) accommodating a refrigerant, a coolant storage tank ( 103 ) disposed between the first tank ( 101 ) and the second tank ( 102 ), a circulation pipe body ( 104 ) configured to supply a coolant stored in the coolant storage tank ( 103 ) to the cooler ( 30 a ) of the dice ( 30 ) and then recover the coolant to the coolant storage tank ( 103 ), a flexible first pipe body ( 105 ) connecting the first tank ( 101 ) and the coolant storage tank ( 103 ) to each other, a flexible second pipe body ( 106 ) connecting the second tank ( 102 ) and the coolant storage tank ( 103 ) to each other, a relay pipe body ( 107 ) disposed inside the coolant storage tank ( 103 ) and connecting the first pipe body ( 105 ) and the second pipe body ( 106 ) to each other, and a tank lifting/lowering device ( 108 ) configured to selectively lift or lower the first tank ( 101 ) and the second tank ( 102 ),
wherein, when the first tank ( 101 ) and the second tank ( 102 ) are selectively lifted or lowered by the tank lifting/lowering device ( 108 ), refrigerant moves between the first tank ( 101 ) and the second tank ( 102 ), and a heat exchange occurs between the refrigerant passing through the relay pipe body ( 107 ) and the coolant recovered to the coolant storage tank ( 103 ).