JPH10122086A - Accumulative fuel injector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an accumulative fuel injector holding its improved signal conductivity even with a smaller size. SOLUTION: The insertion of a pin 50 into a recess 42a formed in a core 42 as well as into a recess 45a formed in a housing 45 positions the core 42 to the housing 45 in the direction of its rotation on the injector axis to thereby regulate the rotation of the core 42 relative to the housing 45. That configuration prevents a seal failure in tightening a nut retainer 48, resulting from electrical short circuit caused by the contact of a deformed terminal with the core 42 or the housing 45, electrical disconnection caused by a break in the terminal or an unbalanced load applied to the sealing member. A projection formed on the core 42 is fitted into a recess formed in the housing 45, or a projection formed on the housing 45 is fitted into a recess formed in the core 42 to thereby establish improved signal conductivity with no increase in the number of component parts used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-accumulating fuel injection device for a diesel engine, which injects high-pressure fuel accumulated in an accumulator into an engine cylinder from an electromagnetic injector.
In particular, it relates to the solenoid valve.

[0002]

2. Description of the Related Art Conventionally, there has been known a fuel injection device in which a signal input member of an electromagnetic valve penetrates a demagnetizing pole surface of a core and a housing provided on the demagnetizing pole side of the core to form a signal input portion outside the injector. Are known. As such a fuel injection device, there is a fuel injection device disclosed in JP-A-5-126010.

[0003]

However, in the structure of the fuel injection device disclosed in JP-A-5-126010, a member for positioning the core relative to the housing in the rotational direction about the axis of the injector is a signal input. There were only members. Therefore, when a force is applied between the core and the housing in the direction of rotation about the axis of the injector, the core and the housing rotate, and as a result, the electric signal generated by the contact between the signal input member and the core or the housing is generated. There is a problem that a short circuit occurs. This problem is particularly remarkable when the injector is reduced in size and weight, and as a result, the signal input member becomes thinner.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a pressure-accumulation fuel injection device that maintains a good signal conduction state without increasing the physical size.

[0005]

According to the pressure accumulating fuel injection device of the present invention, the holding means for restricting relative rotation of the core with respect to the housing in the rotational direction about the axis of the injector is provided. Because of the provision, when a rotational force is applied between the core and the housing, the rotational force is received by the holding means. Therefore, no excessive force is applied to the signal input member, so that the signal input member does not come into contact with the core or the housing, and a good signal conduction state of the injector can be maintained.

According to the pressure accumulating fuel injection device according to the second aspect of the present invention, the core and the housing are provided with the concave portions, and the pins are inserted into the concave portions. Relative rotation in the rotation direction can be restricted, and a good signal conduction state can be maintained without increasing the physical size.

According to the pressure accumulating fuel injection device according to the third aspect of the present invention, since the projection provided on the core is fitted into the recess provided on the housing, the rotation of the core with respect to the housing about the axis of the injector is performed. The relative rotation in the direction can be restricted, and a good signal conduction state can be maintained without increasing the number of components. According to the pressure accumulating fuel injection device according to claim 4 of the present invention, the projection provided on the housing is fitted into the recess provided on the core, so that the core can be rotated with respect to the housing in the rotational direction about the axis of the injector. The relative rotation can be restricted, and a good signal conduction state can be maintained without increasing the number of parts.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plurality of embodiments of the present invention will be described. (First Embodiment) A pressure accumulating fuel injection device according to a first embodiment of the present invention will be described with reference to FIGS.

The injector 1 shown in FIG. 1 is provided with an injection nozzle 10 communicating with the pressure accumulating chamber.
A needle valve (not shown) that opens and closes an injection hole is reciprocally housed inside the nozzle. This needle valve is a solenoid valve 2
Is the throttle hole 2 provided in the flat plate 21 in the control valve 31.
2 is opened and closed to control the pressure inside the control room 20.

The control valve 31 is held by a cylinder 23 fixed to the injector body 11 so as to be able to reciprocate, and an armature 41 is connected to the control valve 31 on the side opposite to the throttle hole. An exciting coil 43 is fitted inside a core 42 arranged facing the armature 41. In the non-excited state, the armature 41 and the control valve 31 are pressed on the flat plate 21 by the urging force of the spring 49 via the push rod 46. At this time, the injection hole is closed by the needle valve. In the excited state, an electromagnetic attractive force is generated between the armature 41 and the core 42 by the magnetic force generated by the exciting coil 43, and the armature 41 and the control valve 31 are attracted to the core 42. When the control valve 31 is separated from the flat plate 21 by the lift of the control valve 31, the throttle hole 22 communicates with the low-pressure chamber 24, and the pressure inside the control chamber 20 decreases. Then, the needle valve is lifted, and fuel is injected from the injection hole.

The distance between the armature 41 and the core 42 is set to a predetermined distance by a spacer 47. Spacer 4
7, the core 42 and the housing 45 are the nut retainer 4
The injector 1 is urged in the axial direction by screwing the cylinder 8 and the cylinder 23 together. The seal member 40 is mounted in the seal member insertion hole 45b of the housing 45 to prevent the fuel from flowing out of the injector 1.

A terminal 44 is provided on the housing 45 side of the exciting coil 43 as a signal input member.
The terminal 44 includes a housing 45 and a core 42.
And is connected to a terminal 52 of a connector 51 for inputting an external signal. FIG. 3 to FIG.
Is shown in a vertical section rotated by 90 degrees about the axis of the injector 1, and an assembled state of the solenoid valve 2 will be described. The pin 50 is inserted into the concave portion 42a provided in the core 42 and the concave portion 45a provided in the housing, and the core 42 is positioned with respect to the housing 45 in the rotation direction about the axis of the injector 1.

Accordingly, when the nut retainer 48 is tightened, even if the core 42 tries to rotate in the rotational direction about the axis of the injector 1 with respect to the housing 45 due to the rotational force generated between the core 42 and the housing 45, Since the pin 50 is fitted in the concave portion 42a and the concave portion 45a, the relative rotation of the core 42 with respect to the housing 45 is restricted. Therefore, since no rotational force is applied to the terminal 44, the terminal 44 contacts the core 42 due to the deformation of the terminal 44, or the terminal 44 and the housing 4
Electrical short by contact with terminal 5, or terminal 44
Can be prevented from being electrically disconnected due to breakage of the wire. Further, it is possible to avoid poor sealing due to an uneven load applied to the sealing member 40.

In the first embodiment, the pin 50 is connected to the terminal 4
4 was rotated 90 degrees. But pin 5
0 may be inserted between the core 42 and the housing 45 at any position that does not interfere with the seal member insertion hole 45b of the housing 45. Also, the pin 50
Is preferably two or more. (Second Embodiment) A second embodiment of the present invention will be described with reference to FIG.

In the second embodiment, only the structure of the solenoid valve 2 is different from that of the first embodiment, and the other structures are the same as those of the first embodiment. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals. In the second embodiment, the core 42
Convex portion 42c provided on the housing 45 and concave portion 45 provided on the housing 45
c, and the core 42 is positioned relative to the housing 45 in the rotation direction about the axis of the injector 1.

Accordingly, when the nut retainer 48 is tightened, even if the core 42 tries to rotate in the rotational direction about the axis of the injector 1 with respect to the housing 45 due to the rotational force generated between the core 42 and the housing 45, The relative rotation of the core 42 with respect to the housing 45 is restricted because the convex portion 42c provided on the core 42 is fitted into the concave portion 45c provided on the housing 45.

Since the solenoid valve 2 has the structure of the second embodiment, the terminal 44 and the core 4 can be connected without increasing the number of parts.
It is possible to avoid an electrical short-circuit due to contact with the housing 2 or the housing 45, an electrical disconnection due to breakage of the terminal 44, or a defective seal due to an uneven load applied to the seal member 40. Third Embodiment A third embodiment of the present invention will be described with reference to FIG.

In the third embodiment, only the structure of the solenoid valve 2 is different from that of the first embodiment, and the other structures are the same as those of the first embodiment. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals. In the third embodiment, a protrusion 45d provided on the housing 45 and a recess 42 provided on the core 42 are provided.
d, and the core 42 is positioned relative to the housing 45 in the rotation direction about the axis of the injector 1.

Thus, when the nut retainer 48 is tightened, even if the core 42 tries to rotate in the rotation direction about the axis of the injector 1 with respect to the housing 45 due to the rotational force generated between the core 42 and the housing 45, Since the protrusion 45d provided on the housing 45 is fitted into the recess 42d provided on the core 42, the relative rotation of the core 42 with respect to the housing 45 is restricted.

Since the solenoid valve 2 has the structure of the third embodiment, the terminal 44 and the core 4 can be connected without increasing the number of parts.
It is possible to avoid an electrical short-circuit due to contact with the housing 2 or the housing 45, an electrical disconnection due to breakage of the terminal 44, or a defective seal due to an uneven load applied to the seal member 40. In the embodiments of the present invention, the armature 41 has a structure arranged on the injection hole side of the core 42.
The armature 41 may have a structure arranged on the side opposite to the injection hole of the core 42.

[Brief description of the drawings]

FIG. 1 is a partial cutaway view of an injector according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of the solenoid valve of FIG.

FIG. 3 is a longitudinal sectional view of FIG. 2 rotated by 90 degrees about the axis of the injector.

FIG. 4 is a perspective view showing a structure of a solenoid valve according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a structure of a solenoid valve according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injector 2 Solenoid valve 10 Injection nozzle 11 Injector body 20 Control room 23 Cylinder 31 Control valve 40 Seal member 41 Armature 42 Core 42a Depression 42c Convex part 42d Depression 43 Excitation coil 44 Terminal (signal input member) 45 Housing 45a Depression 45b Seal member Insertion hole 45c Concave part 45d Convex part 46 Push rod 47 Spacer 48 Nut retainer 49 Spring 50 Pin 51 Connector 52 Terminal

Claims (4)

[Claims] 1. A pressure-accumulation fuel injection device that supplies high-pressure fuel accumulated in an accumulation chamber to an injector provided in each cylinder of an engine, and controls a fuel injection timing and a period by an electromagnetic valve of the injector. An exciting coil of the solenoid valve, a core covering the inner diameter side, the outer diameter side, and one side surface of the coil; an armature arranged opposite to a magnetic pole surface of the core; and a housing arranged on a side opposite to the injection hole of the core. A retainer for urging the core and the housing in the axial direction of the injector; a signal input member penetrating the housing and the housing side of the core; and a center of the axis of the injector of the core with respect to the housing. And a holding means for restricting relative rotation in the rotating direction of the pressure accumulating type fuel injection device. 2. The accumulator type fuel injection device according to claim 1, wherein said holding means is constituted by providing a concave portion in said core and said housing, and inserting a pin into said concave portion. 3. The accumulator type fuel injection device according to claim 1, wherein said holding means is constituted by fitting a convex portion provided on said core into a concave portion provided on said housing. 4. The accumulator type fuel injection device according to claim 1, wherein said holding means is configured by fitting a convex portion provided on said housing to a concave portion provided on said core.