Fuel injector

Patent metadata

Field	Value
Publication number	US-10197028-B2
Application number	US-201515502351-A
Country	US
Kind code	B2
Filing date	Jul 1, 2015
Priority date	Sep 18, 2014
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

A fuel injector is provided. A movable iron core is provided relatively displaceable to a valve body. A fixed iron core is opposed to the movable iron core. A first spring member energizes the valve body in a valve closing direction. A second spring member energizes the movable iron core in a valve closing direction. Contact portions are in contact with each other in a case where the movable iron core displaces in a valve opening direction with respect to the valve body. A gap is formed between the contact portions in a valve closing state. In a state in which the movable iron core and the valve body move in different directions after the movable iron core collides with the fixed iron core while a valve is opened, a spring force is not applied between the movable iron core and the valve body.

First claim

The invention claimed is:

1. A fuel injector, comprising:
a valve seat and a valve body configured to open and close a fuel passage in collaboration with each other;
a movable iron core provided relatively displaceable in valve opening/closing directions to the valve body;
a fixed iron core which generates a magnetic attractive force between end surfaces opposed to each other across the movable iron core and the fixed iron core;
a first spring member energizing the valve body in a valve closing direction;
a second spring member energizing the movable iron core in the valve closing direction;
a contact portion of the valve body and a contact portion of the movable iron core configured to restrict relative displacement of the movable iron core by being in contact with each other in a case where the movable iron core displaces in a valve opening direction with respect to the valve body;
a first gap provided in the valve opening/closing direction between the end surfaces opposed to each other across the movable iron core and the fixed iron core in a valve closing state; and
a second gap provided in the valve opening/closing direction between the contact portion of the valve body and the contact portion of the movable iron core, wherein:
the second spring member is supported by a spring seat and includes a first end portion and a second end portion, the first end portion of the second spring member being in contact with the valve body, and
an intermediate member energized in the valve closing direction by the second spring member when a lower end surface of the intermediate member is in contact with the movable iron core, and an upper end surface of the intermediate member is in contact with the second end portion of the second spring member.

2. A fuel injector, comprising:
a valve seat and a valve body of a valve configured to open and close a fuel passage in collaboration with each other;
a movable iron core provided relatively displaceable in valve opening/closing directions to the valve body;
a fixed iron core which generates a magnetic attractive force between end surfaces opposed to each other across the movable iron core and the fixed iron core;
a first spring member energizing the valve body in a valve closing direction;
a second spring member energizing the movable iron core in the valve closing direction;
a contact portion of the valve body and a contact portion of the movable iron core configured to restrict relative displacement of the movable iron core by being in contact with each other in a case where the movable iron core displaces in a valve opening direction with respect to the valve body;
a first gap provided in the valve opening/closing direction between the end surfaces opposed to each other across the movable iron core and the fixed iron core in a valve closing state; and
a second gap provided in the valve opening/closing direction between the contact portion of the valve body and the contact portion of the movable iron core, wherein:
the first spring member and the second spring member are included such that a spring force does not act between the movable iron core and the valve body in a state in which the movable iron core moves in the valve closing direction, and the valve body moves in the valve opening direction after the movable iron core collides with the fixed iron core while the valve is opened,
the second spring member is supported by a spring seat, wherein one end portion of the second spring member is in contact with the valve body,
an intermediate member energized in the valve closing direction by the second spring member when a lower end surface of the intermediate member is in contact with the movable iron core, and an upper end surface of the intermediate member is in contact with another end portion of the second spring member, and
in the state in which the movable iron core moves in the valve closing direction, and the valve body moves in the valve opening direction after the movable iron core collides with the fixed iron core while the valve is opened, an energizing force of the second spring member is not applied to the movable iron core by separating a lower end surface of the intermediate member from the movable iron core.

3. The fuel injector according to claim 2 , wherein the intermediate member includes an outer peripheral wall portion forming a recessed portion, and the second gap is formed by a height of a step formed by the recessed portion.

4. The fuel injector according to claim 1 , wherein an upper side supporting position, which is positioned on a side opposite to the movable iron core, of the second spring member energizing the movable iron core is positioned on a lower side from a supporting position on a valve body side of the first spring member energizing the valve body.

5. The fuel injector according to claim 1 , wherein in the state in which the movable iron core moves in the valve closing direction, and the valve body moves in the valve opening direction after the movable iron core collides with the fixed iron core while in a valve open state, an energizing force of the second spring member is not applied to the movable iron core by separating a lower end surface of the intermediate member from the movable iron core.

6. The fuel injector according to claim 1 , wherein, the first spring member and the second spring member are included such that a spring force does not act between the movable iron core and the valve body in a state in which the movable iron core moves in the valve closing direction, and the valve body moves in the valve opening direction after the movable iron core collides with the fixed iron core while in a valve open state.

7. The fuel injector according to claim 1 , wherein the intermediate member includes an outer peripheral wall portion forming a recessed portion, and the second gap is formed by a height of a step formed by the recessed portion.

8. The fuel injector according to claim 2 , wherein an upper side supporting position, which is positioned on a side opposite to the movable iron core, of the second spring member energizing the movable iron core is positioned on a lower side from a supporting position on a valve body side of the first spring member energizing the valve body.

Assignees

• Hitachi Automotive Systems Ltd
• Hitachi Automotive Systems Ltd

Inventors

• Yasukawa Yoshihito
• Miyake Takao
• Nakai Atsushi
• Sugaya Masashi
• Miyamoto Akiyasu
• Ogura Kiyotaka
• Abe Motoyuki

Classifications

• F02M51/061 Primary

  using electromagnetic operating means · CPC title

• F02M51/06

  Injectors peculiar thereto {with means directly operating the valve needle} · CPC title

• F02M61/04

  having valves {, e.g. having a plurality of valves in series} · CPC title

• F02M51/0625 Primary

  characterised by arrangement of mobile armatures · CPC title

• F02M61/20

  Closing valves mechanically, e.g. arrangements of springs or weights {or permanent magnets; Damping of valve lift} · CPC title