Method and apparatus for forming valve bodies

Claim 1

An apparatus for producing a valve body from a tubular blank having an open end and a closed end, comprising an upper die and a lower die, each die having a surface adapted to be brought into engagement when the dies are together, each die having a blank gripping portion, with said gripping portions coacting, when the dies are together, to provide a horizontal passage extending entirely through the dies, each die being provided at its center portion with a bulging hole disposed at a right angle with respect to the blank gripping portion, said holes being in registry and in communication with the horizontal passage when the dies are together, a clamp press for clamping the upper and lower dies together provided with a stopper piston inserted into each bulging hole, a pressing piston extending into the horizontal passage from each opposite end thereof for movement relative to each other, one of said pressing pistons having an end portion provided with an oil inlet and an oil outlet, the other of said pressing pistons haVing an end portion corresponding in form to the bottom of a body to be produced, the end portion of said one piston having a surface engaging the edge of the open end of the tubular blank positioned in the passage between said pressing pistons for effecting an oil seal between said one pressing piston and the tubular blank, and the arrangement being such that upon the pressing pistons being moved towards each other, the end portion of said one pressing piston engages the edge of the open end of the blank and the end portion of said other pressing piston engages the closed end of the blank, with introduction of pressure oil through the oil inlet of said one pressing piston into the interior of the blank urging the blank into said bulging holes until blocked by the stopper pistons while the blank is being compressed by said pressing pistons, with the closed end of the blank being deformed to the form of the end portion of said other pressing piston.

Claim 2

An apparatus for producing a valve body from a tubular blank having an open end and a closed end, comprising an upper die and a lower die, each die having a surface adapted to be brought into engagement when the dies are together, each die having a blank gripping portion, with said gripping portions coacting, when the dies are together, to provide a horizontal passage extending entirely through the dies, each die being provided at its center portion with a bulging hole disposed at a right angle with respect to the blank gripping portion, said holes being in registry and in communication with the horizontal passage when the dies are together, a clamp press for clamping the upper and lower dies together provided with a stopper piston inserted into each bulging hole, a pressing piston extending into the horizontal passage from each opposite end thereof for movement relative to each other, one of said pressing pistons having an end portion provided with an oil inlet and an oil outlet, the other of said pressing pistons haVing an end portion corresponding in form to the bottom of a body to be produced, the end portion of said one piston having a surface engaging the edge of the open end of the tubular blank positioned in the passage between said pressing pistons for effecting an oil seal between said one pressing piston and the tubular blank, and the arrangement being such that upon the pressing pistons being moved towards each other, the end portion of said one pressing piston engages the edge of the open end of the blank and the end portion of said other pressing piston engages the closed end of the blank, with introduction of pressure oil through the oil inlet of said one pressing piston into the interior of the blank urging the blank into said bulging holes until blocked by the stopper pistons while the blank is being compressed by said pressing pistons, with the closed end of the blank being deformed to the form of the end portion of said other pressing piston.

Claim 9

A method for forming a valve body from a tubular blank having an open end and a closed end comprising placing the tubular blank in a passage between an upper die and a lower die, with each of said upper and lower dies being provided with a blank gripping portion coacting to define said passage; forming a bulging hole in the center of each of said dies at a right angle to the gripping portion with each hole communicating with the passage; bringing a pressing piston inserted into one end of the passage into oiltight contact with the open end of the blank; introducing pressure oil into the blank through said pressing piston so that, while the blank is being compressed at opposite sides thereof by said pressing piston and a second pressing piston inserted into said passage at the other end thereof, the blank is bulged to the shape defined by said passage, the end surface of said second-pressing piston, said bulging holes and stopper pistons inserted into said bulging holes; and cutting off portions of the formed body which are bulged into said bulging holes.

Claim 10

A method for forming a valve body from a tubular blank having an open end and a closed end comprising placing the tubular blank in a passage between an upper die and a lower die, with each of said upper and lower dies being provided with a blank gripping portion coacting to define said passage; forming a bulging hole in the center of each of said dies at a right angle to the gripping portion with each hole communicating with the passage; bringing a pressing piston inserted into one end of the passage into oiltight contact with the open end of the blank; introducing pressure oil into the blank through said pressing piston so that, while the blank is being compressed at opposite sides thereof by said pressing piston and a second pressing piston inserted into said passage at the other end thereof, the blank is bulged to the shape defined by said passage, the end surface of said second-pressing piston, said bulging holes and stopper pistons inserted into said bulging holes; and cutting off portions of the formed body which are bulged into said bulging holes.

Claim 11

A method for forming a valve body from a tubular blank having an open end and a closed end comprising placing the tubular blank in a passage between an upper die and a lower die, with each of said upper and lower dies being provided with a blank gripping portion coacting to define said passage; forming a bulging hole in the center of each of dies at a right angle to the gripping portion, with each hole communicating with the passage; deforming the blanK to the shape in section of said passage by compressing the blank with said dies; sealing the open end of the blank in an oil-tight manner by advancing separate pressing pistons inserted into said passage at the opposite ends thereof; introducing pressure oil into the blank through one of said pressing pistons so as to bulge the blank to such an extent that the blank is blocked by stopper pistons respectively disposed in said bulging holes while the blank is being compressed by said pressing pistons advanced at the same velocity in operative relationship with each other, with the closed end of the blank thereby being deformed to the shape of the end surface of said pressing piston in contact with the closed end; and cutting off portions of the formed body which are bulged into said bulging holes.

Claim 12

A method for forming a valve body from a tubular blank having an open end and a closed end comprising placing the tubular blank in a passage between an upper die and a lower die, with each of said upper and lower dies being provided with a blank gripping portion coacting to define said passage; forming a bulging hole in the center of each of dies at a right angle to the gripping portion, with each hole communicating with the passage; deforming the blanK to the shape in section of said passage by compressing the blank with said dies; sealing the open end of the blank in an oil-tight manner by advancing separate pressing pistons inserted into said passage at the opposite ends thereof; introducing pressure oil into the blank through one of said pressing pistons so as to bulge the blank to such an extent that the blank is blocked by stopper pistons respectively disposed in said bulging holes while the blank is being compressed by said pressing pistons advanced at the same velocity in operative relationship with each other, with the closed end of the blank thereby being deformed to the shape of the end surface of said pressing piston in contact with the closed end; and cutting off portions of the formed body which are bulged into said bulging holes.