Solenoid device and injection valve having the same

Abstract

An injection valve includes a housing that movably accommodates a needle. A movable core is axially movable together with the needle in the housing. A stationary core is fixed in the housing for forming a magnetic circuit together with the movable core. At least one of the movable core and the stationary core has an end that has an annular first protrusion protruding toward an end of an other of the movable core and the stationary core. At least one of the movable core and the stationary core has an end that has an annular second protrusion protruding toward an end of an other of the movable core and the stationary core. The first protrusion is substantially coaxial with respect to the second protrusion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:

FIG. 1 is a sectional view showing an injector according to a first embodiment;

FIG. 2 is an enlarged sectional side view showing a nozzle of the injector;

FIG. 3 is an enlarged sectional side view showing a movable core and a stationary core of the injector;

FIG. 4 is an enlarged sectional side view showing contact surfaces of the movable core and the stationary core;

FIG. 5A is a sectional view showing contact surfaces of a movable core and a stationary core according to a comparable example, FIGS. 5B, 5C are sectional views showing the contact surfaces of the movable core and the stationary core according to the first embodiment;

FIG. 6 is a sectional view showing contact surfaces of a movable core and a stationary core, according to a second embodiment;

FIG. 7 is a sectional view showing contact surfaces of a movable core and a stationary core, according to a third embodiment; and

FIG. 8 is a sectional view showing contact surfaces of a movable core and a stationary core, according to a fourth embodiment.

Claims

1. An injection valve comprising: a housing that defines a fluid passage therein, the housing having a valve seat;a needle that is provided in the housing, the needle blocking the fluid passage when the needle is seated to the valve seat, the needle communicating the fluid passage when the needle is lifted from the valve seat;a movable core that is provided in the housing, the movable core being axially movable together with the needle; anda stationary core that is fixed in the housing, the stationary core forming a magnetic circuit together with the movable core,wherein at least one of the movable core and the stationary core has an end that has a first protrusion protruding toward an end of an other of the movable core and the stationary core,the first protrusion is in a substantially annular shape,the first protrusion has a first protruding end that is adapted to making contact with the other of the movable core and the stationary core,at least one of the movable core and the stationary core has an end that has a second protrusion protruding toward an end of an other of the movable core and the stationary core,the second protrusion is in a substantially annular shape,the second protrusion has a second protruding end that is adapted to making contact with the other of the movable core and the stationary core, andthe first protrusion is substantially coaxial with respect to the second protrusion.

2. The injection valve according to claim 1, wherein the first protrusion protrudes by a first protruding height,the second protrusion protrudes by a second protruding height, andthe second protruding height is less than the first protruding height.

3. The injection valve according to claim 2, wherein the second protrusion and the end of the other one of the movable core and the stationary core define a gap therebetween in a condition in which the first protrusion makes contact with the end of the other one of the movable core and the stationary core.

4. The injection valve according to claim 1, wherein the second protrusion includes a plurality of second protrusions.

5. The injection valve according to claim 1, wherein the movable core is axially opposed to the stationary core,the first protrusion protrudes toward opposed one of the movable core and the stationary core, andthe second protrusion protrudes toward opposed one of the movable core and the stationary core.

6. A solenoid device comprising: a housing;a movable core that is axially movable in the housing; anda stationary core that is fixed in the housing for constructing a magnetic circuit together with the movable core,wherein the movable core is axially opposed to the stationary core,at least one of the movable core and the stationary core has a first protrusion, which is in a substantially annular shape, axially protruding and adapted to making contact with opposed one of the movable core and the stationary core,at least one of the movable core and the stationary core has a second protrusion, which is in a substantially annular shape, axially protruding and adapted to making contact with opposed one of the movable core and the stationary core, andthe first protrusion is substantially coaxial with respect to the second protrusion.

7. The solenoid device according to claim 6, wherein the first protrusion protrudes by a first protruding height,the second protrusion protrudes by a second protruding height, andthe second protruding height is less than the first protruding height.

8. The solenoid device according to claim 7, wherein the second protrusion and the opposed one of the movable core and the stationary core define a gap therebetween in a condition in which the first protrusion makes contact with the opposed one of the movable core and the stationary core.

9. The solenoid device according to claim 6, wherein the second protrusion includes a plurality of second protrusions.

10. An injection valve comprising: the solenoid device according to claim 6; anda needle that is provided in the housing,wherein the housing defines a fluid passage therein,the housing has a valve seat,the needle is axially movable together with the movable core,the needle blocks the fluid passage when the needle is seated to the valve seat, andthe needle communicates the fluid passage when the needle is lifted from the valve seat.