PILOT TYPE SOLENOID VALVE

Abstract

A pilot type solenoid valve may include a movable core including a main valve and a pilot valve. The main valve may open or close a valve seat. The pilot valve may be connected to a base end side of the main valve and may be axially movable alone such that the movable core is biased in a closing direction by a spring and is slidable in a guide sleeve of a fixed core wound with an electromagnetic coil. When the pilot type solenoid valve is fully open by a electromagnetic force of the electromagnetic coil, a contact portion of the main valve may contact a contacted portion of the guide sleeve to restrict movement of the main valve toward a base end, and the pilot valve may be sucked and held in a state where a base end of the pilot valve does not contact the fixed core.

Claims

1. A pilot type solenoid valve comprising a movable core including: a main valve that opens or closes a valve seat formed between an input port and an output port of a fuel transport path in a valve main body; and a pilot valve connected to a base end side of the main valve so as to be axially movable alone by a predetermined distance such that the movable core is biased in a closing direction by a spring and is slidable in a guide sleeve of a fixed core wound with an electromagnetic coil, a magnetic circuit provided on the electromagnetic coil by energizing the electromagnetic coil to electromagnetically convert the fixed core, the main valve being opened when an electromagnetic force of the electromagnetic coil exceeds a pressure difference between the input port and the output port in the fuel transport path by first sucking the pilot valve of the movable core and opening a pilot valve hole disposed in the main valve; wherein, when the pilot type solenoid valve is fully open by the electromagnetic force of the electromagnetic coil, a contact portion of the main valve is in contact with a contacted portion of the guide sleeve to restrict movement of the main valve toward a base end, and the pilot valve is sucked and held in a state where a base end of the pilot valve is not in contact with the fixed core.

2. The pilot type solenoid valve according to claim 1, wherein the contact portion of the main valve is tapered so as to expand toward a tip.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0012] FIG. 1 is a longitudinal cross-sectional view illustrating a pilot type solenoid valve when being fully closed according to a preferable embodiment of the present invention;

[0013] FIG. 2 is a longitudinal cross-sectional view illustrating the pilot type solenoid valve when being fully open according to the preferable embodiment of the present invention;

[0014] FIG. 3 is an enlarged partial view illustrating a main part of FIG. 2;

[0015] FIG. 4 is a longitudinal cross-sectional view illustrating a pilot type solenoid valve when being fully closed in a conventional example; and

[0016] FIG. 5 is a longitudinal cross-sectional view illustrating the pilot type solenoid valve when being fully open in the conventional example.

DETAILED DESCRIPTION

[0017] Hereinafter, a preferable embodiment of the present invention will be described in detail with reference to the drawings.

[0018] FIGS. 1 to 3 illustrate a preferable embodiment of the present invention, which is basically almost similar to the conventional example illustrated in FIGS. 4 and 5, and the entire description and operation will not be described in detail. The same components as those in the conventional example will be described with the same reference numerals.

[0019] As described above, the present embodiment is almost similar to the conventional example illustrated in FIGS. 4 and 5 as a whole, but is different therefrom in that a main valve 2 to be inserted into a guide sleeve 8 is formed via a tapered contact portion 23 in which a bulging portion 22 having a larger diameter than a contacted portion 81 that is a tip edge of the guide sleeve 8 to be inserted into an outer periphery at a predetermined axial position expands toward a tip side (in particular, refer to FIG. 3).

[0020] As illustrated in FIG. 2, when the pilot type solenoid valve is fully open, by the electromagnetic force of the electromagnetic coil 6, the contact portion 23 of the main valve 2 is in contact with the contacted portion 81 of the guide sleeve 8, and the pilot valve 3 is sucked and held in a state where a base end 32 of the pilot valve 3 is not in contact with the fixed core 7 (a state having a gap S).

[0021] Therefore, in the present embodiment, when the main valve 2 moves from the time when the pilot type solenoid valve is fully closed to the time when the pilot type solenoid valve is fully open, in the conventional example illustrated in FIGS. 4 and 5, the main valve 2 is simply connected to the pilot valve 3 bonded to the fixed core 7 and is not fixed to the guide sleeve 8. Therefore, the main valve 2 collides with the guide sleeve 8 by vibration. However, in the present embodiment, the main valve 2 is held and fixed in a state where the contact portion 23 is in contact with the contacted portion 81 of the guide sleeve 8 and the contact portion 23 is pressed against the guide sleeve 8 toward a base end by a suction force of the pilot valve 3 having the gap S in the fixed core 7 and not adsorbing the base end 32. Therefore, even when there is vibration, the main valve 2 does not collide with the guide sleeve 8, and wear, damage, and the like by vibration can be prevented.

[0022] Furthermore, in the present embodiment, the contact portion 23 of the main valve 2 is tapered so as to expand toward a tip, and can prevent valve opening failure due to axial deviation by self-alignment at the beginning of insertion into the guide sleeve 8 at the beginning of opening.