Method for manufacturing injection hole member

Abstract

A lead hole is formed in a base material of an injection hole member with a straight punch, and then, a taper hole is formed in the base material by widening the lead hole with a taper punch. An intersection line between a virtual plane perpendicular to a central axis of the lead hole and an inner peripheral surface of the lead hole is elliptic in shape, whose major axis is directed along an intersection line between a virtual plane, which includes the central axis of the lead hole and a thickness direction axis of the base material, and the virtual plane perpendicular to the central axis of the lead hole. An intersection line between a virtual plane perpendicular to a central axis of the taper punch and an outer peripheral surface of the taper punch is round in shape.

What is claimed is:  
     
         1 . A method for manufacturing an injection hole member formed with a taper hole, which serves as at least a part of an injection hole, the taper hole being formed so that a central axis of the taper hole is inclined with respect to an axis of a base material of the injection hole member in a thickness direction of the base material and a diameter of the taper hole increases in a direction from an end surface of the base material to the other end surface of the base material, the method comprising the steps of: 
 forming a lead hole in the base material through punch press with a punch, the lead hole being formed so that a central axis of the lead hole is inclined with respect to the axis of the base material in the thickness direction thereof and a diameter of the lead hole is substantially constant along an extending direction of the central axis of the lead hole; and    forming a taper hole in the base material by widening the lead hole with a taper punch, whose tip end is inserted into the lead hole in a state where a central axis of the taper punch is inclined to the same side as the central axis of the lead hole with respect to the axis of the base material in the thickness direction thereof, the taper punch being formed so that a diameter of the taper punch decreases toward the tip end thereof, wherein    the injection hole member is formed so that an intersection line between a first reference plane, which is a virtual plane perpendicular to the central axis of the lead hole, and an inner peripheral surface of the lead hole is in an elliptic shape or a oval shape, whose major axis is directed in an extending direction of a reference axis, which is an intersection line between the first reference plane and a virtual plane including the central axis of the lead hole and the axis of the base material in the thickness direction thereof, and    the injection hole member is formed so that an intersection line between a second reference plane, which is perpendicular to the central axis of the taper punch, and an outer peripheral surface of the taper punch is round in shape.    
     
     
         2 . A method for manufacturing an injection hole member formed with a taper hole, which serves as at least a part of an injection hole, the taper hole being formed so that a central axis of the taper hole is inclined with respect to an axis of a base material of the injection hole member in a thickness direction of the base material and a diameter of the taper hole increases in a direction from an end surface of the base material to the other end surface of the base material, the method comprising the steps of: 
 forming a lead hole in the base material through punch press with a punch, the lead hole being formed so that a central axis of the lead hole is inclined with respect to the axis of the base material in the thickness direction thereof and a diameter of the lead hole is substantially constant along an extending direction of the central axis of the lead hole; and    forming a taper hole in the base material by widening the lead hole with a taper punch, whose tip end is inserted into the lead hole in a state where a central axis of the taper punch is inclined to the same side as the central axis of the lead hole with respect to the axis of the base material in the thickness direction thereof, the taper punch being formed so that a diameter of the taper punch decreases toward the tip end thereof, wherein    the injection hole member is formed so that an intersection line between a first reference plane, which is a virtual plane perpendicular to the central axis of the lead hole, and an inner peripheral surface of the lead hole is round in shape, and    the injection hole member is formed so that an intersection line between a second reference plane, which is perpendicular to the central axis of the taper punch, and an outer peripheral surface of the taper punch is in an elliptic shape or an oval shape, whose major axis is directed in an extending direction of a reference axis, which is a line perpendicularly crossing an intersection line between a virtual plane, which includes the central axis of the taper punch and the axis of the base material in the thickness direction thereof, and the second reference plane on the second reference plane.    
     
     
         3 . A method for manufacturing an injection hole member formed with a taper hole, which serves as at least a part of an injection hole, the taper hole being formed so that a central axis of the taper hole is inclined with respect to an axis of a base material of the injection hole member in a thickness direction of the base material and a diameter of the taper hole increases in a direction from an end surface of the base material to the other end surface of the base material, the method comprising the steps of: 
 forming a lead hole in the base material through punch press with a punch, the lead hole being formed so that a central axis of the lead hole is inclined with respect to the axis of the base material in the thickness direction thereof and a diameter of the lead hole is substantially constant along an extending direction of the central axis of the lead hole; and    forming a taper hole in the base material by widening the lead hole with a taper punch, whose tip end is inserted into the lead hole in a state where a central axis of the taper punch is inclined to the same side as the central axis of the lead hole with respect to the axis of the base material in the thickness direction thereof, the taper punch being formed so that a diameter of the taper punch decreases toward the tip end thereof, wherein    the injection hole member is formed so that an intersection line between a first reference plane, which is perpendicular to the central axis of the lead hole, and an inner peripheral surface of the lead hole is in an elliptic shape or an oval shape, whose major axis is directed in an extending direction of a first reference axis, which is an intersection line between the first reference plane and a virtual plane including the central axis of the lead hole and the axis of the base material in the thickness direction thereof, and    the injection hole member is formed so that an intersection line between a second reference plane, which is perpendicular to the central axis of the taper punch, and an outer peripheral surface of the taper punch is in an elliptic shape or an oval shape, whose major axis is directed in an extending direction of a second reference axis, which perpendicularly crosses an intersection line between a virtual plane, which includes the central axis of the taper punch and the axis of the base material in the thickness direction thereof, and the second reference plane on the second reference plane.    
     
     
         4 . The method for manufacturing the injection hole member as in any one of  claims 1  to  3 , wherein 
 the punch for forming the lead hole and the taper punch are driven into the base material in the state where the central axes thereof are inclined in substantially the same inclination angle with respect to the axis of the base material in the thickness direction thereof.  
 
     
     
         5 . The method for manufacturing the injection hole member as in any one of  claims 1  to  3 , wherein 
 the punch for forming the lead hole and the taper punch are driven into the base material in a state where the central axes thereof are inclined in different inclination angles with respect to the axis of the base material in the thickness direction thereof.  
 
     
     
         6 . The method for manufacturing the injection hole member as in any one of  claims 1  to  3 , wherein 
 a ratio of a first diameter of the taper punch on a first coordinate axis to a second diameter of the taper punch on a second coordinate axis is smaller than a ratio of a first diameter of the lead hole on the first coordinate axis to a second diameter of the lead hole on the second coordinate axis, wherein the first coordinate axis is an intersection line between a virtual plane, which includes the central axes of the lead hole and the taper punch and the axis of the base material in the thickness direction thereof, and a coordinate plane provided by another virtual plane perpendicular to the axis of the base material in the thickness direction thereof, and the second coordinate axis perpendicularly crosses the first coordinate axis on the coordinate plane.  
 
     
     
         7 . The method for manufacturing the injection hole member as in any one of  claims 1  to  3 , wherein 
 the taper punch is inserted into the lead hole in a direction opposite to a pressing direction for forming the lead hole, when the taper hole is formed.  
 
     
     
         8 . The method for manufacturing the injection hole member as in any one of  claims 1  to  3 , wherein 
 the taper hole provides a portion whose internal diameter increases along a direction from the upstream end toward the downstream end of the injection hole.  
 
     
     
         9 . A method for manufacturing an injection hole member formed with an injection hole for injecting fluid, the method comprising the steps of: 
 forming a taper hole in a base material of the injection hole member through punch press so that a diameter of the taper hole increases along a direction from an end surface of the base material to the other end surface of the base material; and    forming a straight hole in the base material by widening a smaller diameter opening of the taper hole through punch press so that an inner peripheral surface of the straight hole connects to an inner peripheral surface of the remaining taper hole, wherein    the injection hole is provided by the taper hole and the straight hole.    
     
     
         10 . The method for manufacturing the injection hole member as in  claim 9 , wherein 
 the straight hole is formed through the punch press with a straight punch, whose diameter is substantially constant toward its tip end, along a direction of a central axis of the straight punch.    
     
     
         11 . The method for manufacturing the injection hole member as in  claim 10 , wherein 
 the straight hole is formed through the punch press with the straight punch, whose diameter is smaller than a diameter of a larger diameter opening of the taper hole, along a direction from the larger diameter opening toward the smaller diameter opening of the taper hole.    
     
     
         12 . The method for manufacturing the injection hole member as in  claim 10  or  11 , wherein 
 the straight hole provides an upstream end opening of the injection hole.  
 
     
     
         13 . The method for manufacturing the injection hole member as in  claim 12 , wherein 
 the straight hole is formed with the straight punch, whose outline on a cross section perpendicular to the central axis thereof is in an elliptic shape or a shape defined by two parallel lines joined with semi-circular ends, and is formed through the punch press along a direction of the central axis of the straight punch inclined with respect to the central axis of the taper hole.    
     
     
         14 . The method for manufacturing the injection hole member as in  claim 9 , wherein 
 the taper hole is formed through the punch press with a taper punch, whose diameter decreases toward its tip end, along a direction toward the tip end of the taper punch, and    the taper hole is formed by driving the taper punch into the base material in a state where the taper punch is inclined with respect to an axis of the base material in its thickness direction.    
     
     
         15 . The method for manufacturing the injection hole member as in  claim 14 , wherein 
 the taper hole is formed with the taper punch whose central axis is inclined with respect to the axis of the base material in its thickness direction and with a guide for guiding the taper punch in a pressing direction by contacting an outer peripheral surface of the taper punch on an opposite side from the base material.    
     
     
         16 . The method for manufacturing the injection hole member as in  claim 9 , further comprising the step of: 
 forming a lead hole in the base material through punch press before the taper hole is formed, wherein    the taper hole is formed with a taper punch, whose diameter decreases toward its tip end,    the taper punch is driven in a pressing direction toward its tip end, and    the taper hole is formed by widening the lead hole with the taper punch.    
     
     
         17 . The method for manufacturing the injection hole as in  claim 16 , wherein 
 the taper hole is formed through the punch press in a direction opposite to a pressing direction for forming the lead hole.    
     
     
         18 . The method for manufacturing the injection hole as in  claim 9 , wherein 
 the injection hole member is formed so that two intersection lines provided between a cross section of the base material in its thickness direction and an inner peripheral surface of the taper hole are inclined to the same side with respect to the axis of the base material in its thickness direction, and    the injection hole member is formed so that an inclination angle provide by one of the two intersection lines and the axis of the base material in its thickness direction is smaller than another inclination angle provided by the other intersection line and the axis of the base material in its thickness direction.    
     
     
         19 . A method for manufacturing an injection hole member formed with an injection hole for injecting fluid, the method comprising: 
 an injection hole forming step of forming the injection hole so that an axis of the injection hole in an injection direction is inclined with respect to an axis of a base material of the injection hole member in its thickness direction, and    a concave portion forming step of forming a concave portion caving in radially outward from an inner peripheral surface providing the injection hole in an edge of a downstream end opening of the injection hole.    
     
     
         20 . The method for manufacturing the injection hole member as in  claim 19 , wherein 
 the injection hole is a taper hole whose diameter increases toward its downstream end.    
     
     
         21 . The method for manufacturing the injection hole member as in  claim 20 , further comprising: 
 a lead hole forming step of forming a lead hole before the injection hole is formed so that a central axis of the lead hole is inclined with respect to the axis of the base material in its thickness direction and the lead hole penetrates the base material, wherein    the injection hole is formed by inserting a taper punch, whose diameter decreases toward its tip end, into the lead hole from the downstream end of the injection hole and by widening the lead hole in the injection hole forming step.    
     
     
         22 . The method for manufacturing the injection hole member as in  claim 19 , wherein 
 the concave portion is formed through a grinding process.    
     
     
         23 . The method for manufacturing the injection hole member as in  claim 19 , wherein 
 the injection hole is formed while setting an inclination angle of the axis of the injection hole with respect to the axis of the base material in its thickness direction in the injection hole forming step so that an injection angle of fluid spray injected from the injection hole is larger than a target range in a state before the concave portion is formed, and    the injection angle is regulated into the target range by forming the concave portion and decreasing the injection angle in the concave portion forming step.    
     
     
         24 . The method for manufacturing the injection hole member as in  claim 23 , wherein 
 the concave portion forming step includes a measuring step of measuring the injection angle and a processing step of processing the concave portion based on the measured injection angle if the measured injection angle is larger than the target range, and    the injection angle is regulated into the target range by repeating the measuring step and the processing step.    
     
     
         25 . A method for manufacturing an injection hole member formed with an injection hole for injecting fluid, the method comprising: 
 a lead hole forming step of forming a lead hole by punching out a base material of the injection hole member with a lead hole punch along a direction from an upstream end surface toward a downstream end surface of the base material so that a central axis of the lead hole is inclined with respect to an axis of the base material in its thickness direction, and of forming an enlarged diameter portion in an edge of a downstream end opening of the lead hole by breaking the edge of the downstream end opening of the lead hole with the lead hole punch, and    an injection hole forming step of forming the injection hole so that a diameter of the injection hole increases along a direction from the upstream end surface to the downstream end surface of the base material and an axis of the injection hole in an injection direction is inclined with respect to the axis of the base material in its thickness direction by inserting a taper punch, whose diameter decreases toward its tip end, into the lead hole from a downstream end of the lead hole and by widening the lead hole, and of forming a concave portion, which caves in radially outward from an inner peripheral surface providing the injection hole, in an edge of a downstream end opening of the injection hole by remaining at least a part of the enlarged diameter portion when the injection hole is formed.    
     
     
         26 . The method for manufacturing the injection hole member as in  claim 25 , wherein 
 the lead hole is formed by positioning a die formed with a receiving cavity, whose diameter is larger than a diameter of the lead hole punch, on the downstream end surface of the base material and by punching out the base material with the lead hole punch in a direction toward the receiving cavity in the lead hole forming step.    
     
     
         27 . The method for manufacturing the injection hole member as in  claim 19  or  25 , wherein 
 the injection hole is formed so that one of two injection hole intersection lines between a virtual plane, which includes the axis of the injection hole and is perpendicular to the base material, and the inner peripheral surface of the injection hole provides an acute angle with a downstream end plane of the injection hole and the other injection hole intersection line provides a blunt angle with the downstream end plane of the injection hole.  
 
     
     
         28 . The method for manufacturing the injection hole member as in  claim 27 , wherein 
 the concave portion is formed in the edge of the downstream end opening of the injection hole at least on a side where the acute angle is provided between the injection hole intersection line and the downstream end plane of the injection hole.    
     
     
         29 . The method for manufacturing the injection hole member as in  claim 19  or  25 , wherein 
 the injection hole member is formed with a plurality of injection holes in the injection hole forming step so that the axes of the injection holes separate from the central axis of the injection hole member, along the injection directions.  
 
     
     
         30 . The method for manufacturing the injection hole member as in  claim 29 , wherein 
 the spray is injected from the plurality of injection holes in two directions opposite from each other.    
     
     
         31 . An injection hole member formed with an injection hole for injecting fluid, wherein 
 the injection hole member is formed so that an axis of the injection hole in an injection direction is inclined with respect to a central axis of the injection hole member, and    the injection hole member is formed with a concave portion in an edge of a downstream end opening of the injection hole, the concave portion caving in radially outward from an inner peripheral surface of the injection hole.    
     
     
         32 . The injection hole member as in  claim 31 , wherein 
 the injection hole is a taper hole, whose diameter increases toward a downstream side.    
     
     
         33 . The injection hole member as in  claim 31  or  32 , wherein 
 the injection hole member is formed so that one of two intersection lines between a virtual plane, which includes the axis of the injection hole and is perpendicular to the injection hole member, and the inner peripheral surface of the injection hole provides an acute angle with a downstream end surface of the injection hole member, and the other intersection line provides a blunt angle with the downstream end surface of the injection hole member.  
 
     
     
         34 . The injection hole member as in  claim 33 , wherein 
 the concave portion is formed in the edge of the downstream end opening of the injection hole at least on a side where the injection hole intersection line and the downstream end surface of the injection hole member provide the acute angle.    
     
     
         35 . The injection hole member as in  claim 31 , wherein 
 the injection hole member is formed with a plurality of injection holes so that the axes of the injection holes separate from the central axis of the injection hole member along the injection directions.    
     
     
         36 . The injection hole member as in  claim 35 , wherein 
 the spray is injected from the plurality of injection holes in two directions opposite from each other.