초록 ▼

An object of the invention is to provide a depressurizing valve mounted to a common rail for a fuel injection device, in which a direction of a connector for the depressurizing valve can be adjusted, without affecting an air gap and a sealing performance. The depressurizing valve has a valve unit an

An object of the invention is to provide a depressurizing valve mounted to a common rail for a fuel injection device, in which a direction of a connector for the depressurizing valve can be adjusted, without affecting an air gap and a sealing performance. The depressurizing valve has a valve unit and a coil unit which is detachably assembled to the valve unit by a mounting member, such as a retaining nut. A valve housing has an inside space, which is fluid tightly separated into first and second spaces by a connecting member, which is fluid tightly connected to the valve housing and a stator core. A valve body and a spring are arranged in the first space for closing a flow control port. A cylindrical coil is accommodated in the second space, such that the coil is rotatable with respect to the valve housing.

대표청구항 ▼

What is claimed is: 1. A fuel injection device for an internal combustion engine comprising: a common rail for storing high pressure fuel; a fuel injection valve for injecting the high pressure fuel of the common rail into the engine; a fuel return path operatively connected between the common rail

What is claimed is: 1. A fuel injection device for an internal combustion engine comprising: a common rail for storing high pressure fuel; a fuel injection valve for injecting the high pressure fuel of the common rail into the engine; a fuel return path operatively connected between the common rail and a low pressure side; and a depressurizing valve for opening and closing the fuel return path so that a part of the high pressure fuel flows from the common rail to the low pressure side when the fuel return path is opened by the depressurizing valve, wherein the depressurizing valve comprises; a valve unit having a valve body for opening and closing the fuel return path; and a coil unit having a cylindrical electromagnetic coil for attracting the valve body in a valve opening direction when electric current is supplied to the electromagnetic coil, wherein the valve unit further comprises; a valve housing of a cylindrical shape, which is firmly fixed to the common rail; an armature integrally formed with the valve body; a first space formed in the valve housing for accommodating the valve body and armature, and connected to the fuel return path; a second space formed in the valve housing for accommodating the electromagnetic coil, such that the electromagnetic coil is rotatable with respect to the valve housing in a circumferential direction, the second space being formed coaxially with the first space; a stator core arranged in an inner peripheral space of the electromagnetic coil and axially opposing to the armature; a connecting member fluid tightly connected to the valve housing and to the stator core, for dividing, together with the stator core, an inside space of the valve housing into the first and second spaces; and a valve seat provided at one end of the first space and having a flow control port for operatively communicating the first space with a high pressure chamber of the common rail by an axial movement of the valve body, wherein the valve body and the armature are axially and movably held in the first space between the valve seat and the stator core; and wherein the coil unit is detachably assembled to the valve unit and further comprises; a connector integrally formed with the electromagnetic coil; a plate member, which is made of a magnetic material, arranged between the electromagnetic coil and the connector, and integrally molded with the connector; a terminal integrally molded in the connector and electrically connected to the electromagnetic coil; a through-hole formed in the plate member, through which the terminal passes; and a mounting member selectively screwed to the valve unit for detachably mounting the electromagnetic coil and the connector to the valve unit, wherein the coil unit is rotatable relative to the mounting member, so that when the mounting member is loosened from a firmly fixed position thereof, the coil unit can be rotated with respect to the mounting member so that a circumferential position of the connector with respect to the mounting member can be adjusted, wherein the mounting member has a cylindrical portion and a flanged portion inwardly extending from one longitudinal end of the cylindrical portion, a female screw portion is formed at an inner peripheral surface of the cylindrical portion so that the mounting member is selectively screwed to the valve unit, and the flanged portion holds an outer peripheral portion of the plate member when the mounting member is screwed to the valve unit. 2. A fuel injection device according to claim 1, wherein the connecting member is made of a non-magnetic material. 3. A fuel injection device according to claim 1, wherein a recessed portion is formed in the stator core and opening to the first space, and a spring is arranged in the recessed portion for biasing the valve body in a valve closing direction. 4. A fuel injection device for an internal combustion engine comprising: a common rail for storing high pressure fuel; a fuel injection valve for injecting the high pressure fuel of the common rail into the engine; a fuel return path operatively connected between the common rail and a low pressure side, and a depressurizing valve for opening and closing the fuel return path so that a part of the high pressure fuel flows from the common rail to the low pressure side when the fuel return path is opened by the depressurizing valve, wherein the depressurizing valve comprises; a valve unit having a valve body for opening and closing the fuel return path; and a coil unit having a cylindrical electromagnetic coil for attracting the valve body in a valve opening direction when electric current is supplied to the electromagnetic coil, wherein the valve unit further comprises; a valve housing of a cylindrical shape, which is firmly fixed to the common rail; an armature integrally formed with the valve body; a first space formed in the valve housing for accommodating the valve body and armature, and connected to the fuel return path; a second space formed in the valve housing for accommodating the electromagnetic coil, such that the electromagnetic coil is rotatable with respect to the valve housing in a circumferential direction, the second space being formed coaxially with the first space; a stator core arranged in an inner peripheral space of the electromagnetic coil and axially opposing to the armature; a connecting member fluid tightly connected to the valve housing and to the stator core, for dividing, together with the stator core, an inside space of the valve housing into the first and second spaces; and a valve seat provided at one end of the first space and having a flow control port for operatively communicating the first space with a high pressure chamber of the common rail by an axial movement of the valve body, wherein the valve body and the armature are axially and movably held in the first space between the valve seat and the stator core; and wherein the coil unit is detachably assembled to the valve unit and further comprises; a connector integrally formed with the electromagnetic coil; a mounting member selectively screwed to the valve unit for detachably mounting the electromagnetic coil and the connector to the valve unit, wherein the coil unit is rotatable relative to the mounting member, so that a circumferential position of the connector can be adjusted when the mounting member is loosened from a firmly fixed position thereof; a plate member, which is made of a magnetic material, arranged between the electromagnetic coil and the connector, and integrally molded with the connector; a terminal integrally molded in the connector and electrically connected to the electromagnetic coil; and a through-hole formed in the plate member, through which the terminal passes, wherein the plate member is a disc-shaped member opposing to the valve housing and the stator core, and the mounting member is a retaining nut to be screwed to the valve housing, wherein the plate member is interposed between the valve housing and the retaining nut, and wherein the retaining nut has a cylindrical portion and a flanged portion inwardly extending from one longitudinal end of the cylindrical portion, a female screw portion is formed at an inner peripheral surface of the cylindrical portion so that the retaining nut is selectively screwed to the valve housing, and the flanged portion holds an outer peripheral portion of the plate member when the retaining nut is screwed to the valve housing, whereby when the retaining nut is screwed to the valve housing, the connector does not rotate with the retaining nut, so that a circumferential position of the connector and plate integrally molded therewith can be maintained. 5. A fuel injection device for an internal combustion engine comprising: a common rail for storing high pressure fuel; a fuel injection valve for injecting the high pressure fuel of the common rail into the engine; a fuel return path operatively connected between the common rail and a low pressure side; and a depressurizing valve mounted to the common rail for opening and closing the fuel return path so that a part of the high pressure fuel flows from the common rail to the low pressure side when the fuel return path is opened by the depressurizing valve, wherein the depressurizing valve comprises; a valve unit having a valve body for opening and closing the fuel return path; and a coil unit having a cylindrical electromagnetic coil for attracting the valve body in a valve opening direction when electric current is supplied to the electromagnetic coil, wherein the valve unit further comprises; a valve housing of a cylindrical shape, which is firmly fixed to the common rail; an armature integrally formed with the valve body; a first space formed in the valve housing for accommodating the valve body and armature, and connected to the fuel return path; a second space formed in the valve housing for accommodating the electromagnetic coil, such that the electromagnetic coil is rotatable with respect to the valve housing in a circumferential direction, the second space being formed coaxially with the first space; a stator core arranged in an inner peripheral space of the electromagnetic coil and axially opposing to the armature; a connecting member integrally formed with one of the valve housing and the stator core, for fluid tightly dividing, together with the stator core, an inside space of the valve housing into the first and second spaces, wherein the connecting member restricts magnetic flux flow between the stator core and the valve housing; and a valve seat provided at one end of the first space and having a flow control port for operatively communicating the first space with a high pressure chamber of the common rail by an axial movement of the valve body, wherein the valve body and the armature are axially and movably held in the first space between the valve seat and the stator core; and wherein the coil unit is detachably assembled to the valve unit and further comprises; a connector integrally formed with the electromagnetic coil; a plate member, which is made of a magnetic material, arranged between the electromagnetic coil and the connector, and integrally molded with the connector; a terminal integrally molded in the connector and electrically connected to the electromagnetic coil; a through-hole formed in the plate member, through which the terminal passes; and a mounting member selectively screwed to the valve unit for detachably mounting the electromagnetic coil and the connector to the valve unit, wherein the coil unit is rotatable relative to the mounting member, so that when the mounting member is loosened from a firmly fixed position thereof, the coil unit can be rotated with respect to the mounting member so that a circumferential position of the connector with respect to the mounting member can be adjusted, wherein the mounting member has a cylindrical portion and a flanged portion inwardly extending from one longitudinal end of the cylindrical portion, a female screw portion is formed at an inner peripheral surface of the cylindrical portion so that the mounting member is selectively screwed to the valve unit, and the flanged portion holds an outer peripheral portion of the plate member when the mounting member is screwed to the valve unit. 6. A fuel injection device according to claim 5, wherein a recessed portion is formed in the stator core and opening to the first space, and a spring is arranged in the recessed portion for biasing the valve body in a valve closing direction. 7. A fuel injection device for an internal combustion engine comprising: a common rail for storing high pressure fuel; a fuel injection valve for injecting the high pressure fuel of the common rail into the engine; a fuel return path operatively connected between the common rail and a low pressure side; and a depressurizing valve mounted to the common rail for opening and closing the fuel return path so that a part of the high pressure fuel flows from the common rail to the low pressure side when the fuel return path is opened by the depressurizing valve, wherein the depressurizing valve comprises; a valve unit having a valve body for opening and closing the fuel return path; and a coil unit having a cylindrical electromagnetic coil for attracting the valve body in a valve opening direction when electric current is supplied to the electromagnetic coil, wherein the valve unit further comprises; a valve housing of a cylindrical shape, which is firmly fixed to the common rail; an armature integrally formed with the valve body; a first space formed in the valve housing for accommodating the valve body and armature, and connected to the fuel return path; a second space formed in the valve housing for accommodating the electromagnetic coil, such that the electromagnetic coil is rotatable with respect to the valve housing in a circumferential direction, the second space being formed coaxially with the first space; a stator core arranged in an inner peripheral space of the electromagnetic coil and axially opposing to the armature; a connecting member integrally formed with one of the valve housing and the stator core, for fluid tightly dividing, together with the stator core, an inside space of the valve housing into the first and second spaces, wherein the connecting member restricts magnetic flux flow between the stator core and the valve housing; and a valve seat provided at one end of the first space and having a flow control port for operatively communicating the first space with a high pressure chamber of the common rail by an axial movement of the valve body, wherein the valve body and the armature are axially and movably held in the first space between the valve seat and the stator core; and wherein the coil unit is detachably assembled to the valve unit and further comprises; a connector integrally formed with the electromagnetic coil; a mounting member selectively screwed to the valve unit for detachably mounting the electromagnetic coil and the connector to the valve unit, wherein the coil unit is rotatable relative to the mounting member, so that a circumferential position of the connector can be adjusted when the mounting member is loosened from a firmly fixed position thereof; a plate member, which is made of a magnetic material, arranged between the electromagnetic coil and the connector, and integrally molded with the connector; a terminal integrally molded in the connector and electrically connected to the electromagnetic coil; and a through-hole formed in the plate member, through which the terminal passes, wherein the plate member is a disc-shaped member opposing to the valve housing and the stator core, and the mounting member is a retaining nut to be screwed to the valve housing, wherein the plate member is interposed between the valve housing and the retaining nut, and wherein the retaining nut has a cylindrical portion and a flanged portion inwardly extending from one longitudinal end of the cylindrical portion, a female screw portion is formed at an inner peripheral surface of the cylindrical portion so that the retaining nut is selectively screwed to the valve housing, and the flanged portion holds an outer peripheral portion of the plate member when the retaining nut is screwed to the valve housing, whereby when the retaining nut is screwed to the valve housing, the connector does not rotate with the retaining nut, so that a circumferential position of the connector and plate integrally molded therewith can be maintained. 8. A fuel injection device for an internal combustion engine comprising: a common rail for storing high pressure fuel; a fuel injection valve for injecting the high pressure fuel of the common rail into the engine; a fuel return path operatively connected between the common rail and a low pressure side; and a depressurizing valve mounted to the common rail for opening and closing the fuel return path so that a part of the high pressure fuel flows from the common rail to the low pressure side when the fuel return path is opened by the depressurizing valve, wherein the depressurizing valve comprises; a valve unit having a valve body for opening and closing the fuel return path; and a coil unit having a cylindrical electromagnetic coil for attracting the valve body in a valve opening direction when electric current is supplied to the electromagnetic coil, wherein the valve unit further comprises; a valve housing of a cylindrical shape, which is firmly fixed to the common rail; an armature integrally formed with the valve body; a first space formed in the valve housing for accommodating the valve body and armature, and connected to the fuel return path; a second space formed in the valve housing for accommodating the electromagnetic coil, such that the electromagnetic coil is rotatable with respect to the valve housing in a circumferential direction, the second space being formed coaxially with the first space; a stator core arranged in an inner peripheral space of the electromagnetic coil and axially opposing to the armature; a connecting member integrally formed with and arranged between the valve housing and the stator core, wherein the connecting member and the stator core divide an inside space of the valve housing into the first and second spaces, and wherein the connecting member restricts magnetic flux flow between the stator core and the valve housing; and a valve seat provided at one end of the first space and having a flow control port for operatively communicating the first space with a high pressure chamber of the common rail by an axial movement of the valve body, wherein the valve body and the armature are axially and movably held in the first space between the valve seat and the stator core; and wherein the coil unit is detachably assembled to the valve unit and further comprises; a connector integrally formed with the electromagnetic coil; a plate member, which is made of a magnetic material, arranged between the electromagnetic coil and the connector, and integrally molded with the connector; a terminal integrally molded in the connector and electrically connected to the electromagnetic coil; a through-hole formed in the plate member, through which the terminal passes; and a mounting member selectively screwed to the valve unit for detachably mounting the electromagnetic coil and the connector to the valve unit, wherein the coil unit is rotatable relative to the mounting member, so that when the mounting member is loosened from a firmly fixed position thereof, the coil unit can be rotated with respect to the mounting member so that an angular position of the connector with respect to the mounting member can be adjusted, wherein the mounting member has a cylindrical portion and a flanged portion inwardly extending from one longitudinal end of the cylindrical portion, a female screw portion is formed at an inner peripheral surface of the cylindrical portion so that the mounting member is selectively screwed to the valve unit, and the flanged portion holds an outer peripheral portion of the plate member when the mounting member is screwed to the valve unit. 9. A fuel injection device according to claim 8, wherein a recessed portion is formed in the stator core and opening to the first space, and a spring is arranged in the recessed portion for biasing the valve body in a valve closing direction. 10. A fuel injection device for an internal combustion engine comprising: a common rail for storing high pressure fuel; a fuel injection valve for injecting the high pressure fuel of the common rail into the engine; a fuel return path operatively connected between the common rail and a low pressure side; and a depressurizing valve mounted to the common rail for opening and closing the fuel return path so that a part of the high pressure fuel flows from the common rail to the low pressure side when the fuel return path is opened by the depressurizing valve, wherein the depressurizing valve comprises; a valve unit having a valve body for opening and closing the fuel return path; and a coil unit having a cylindrical electromagnetic coil for attracting the valve body in a valve opening direction when electric current is supplied to the electromagnetic coil, wherein the valve unit further comprises; a valve housing of a cylindrical shape, which is firmly fixed to the common rail; an armature integrally formed with the valve body; a first space formed in the valve housing for accommodating the valve body and armature, and connected to the fuel return path; a second space formed in the valve housing for accommodating the electromagnetic coil, such that the electromagnetic coil is rotatable with respect to the valve housing in a circumferential direction, the second space being formed coaxially with the first space; a stator core arranged in an inner peripheral space of the electromagnetic coil and axially opposing to the armature; a connecting member integrally formed with and arranged between the valve housing and the stator core, wherein the connecting member and the stator core divide an inside space of the valve housing into the first and second spaces, and wherein the connecting member restricts magnetic flux flow between the stator core and the valve housing; and a valve seat provided at one end of the first space and having a flow control port for operatively communicating the first space with a high pressure chamber of the common rail by an axial movement of the valve body, wherein the valve body and the armature are axially and movably held in the first space between the valve seat and the stator core; wherein the coil unit is detachably assembled to the valve unit and further comprises; a connector integrally formed with the electromagnetic coil; a mounting member selectively screwed to the valve unit for detachably mounting the electromagnetic coil and the connector to the valve unit, wherein the coil unit is rotatable relative to the mounting member, so that a circumferential position of the connector can be adjusted when the mounting member is loosened from a firmly fixed position thereof; a plate member, which is made of a magnetic material, arranged between the electromagnetic coil and the connector, and integrally molded with the connector; a terminal integrally molded in the connector and electrically connected to the electromagnetic coil; and a through-hole formed in the plate member, through which the terminal passes, wherein the plate member is a disc-shaped member opposing to the valve housing and the stator core, and the mounting member is a retaining nut to be screwed to the valve housing, wherein the plate member is interposed between the valve housing and the retaining nut, and wherein the retaining nut has a cylindrical portion and a flanged portion inwardly extending from one longitudinal end of the cylindrical portion, a female screw portion is formed at an inner peripheral surface of the cylindrical portion so that the retaining nut is selectively screwed to the valve housing, and the flanged portion holds an outer peripheral portion of the plate member when the retaining nut is screwed to the valve housing, whereby when the retaining nut is screwed to the valve housing, the connector does not rotate with the retaining nut, so that a circumferential position of the connector and plate integrally molded therewith can be maintained.