JPS5827876A - Electromagnetic fuel injection valve - Google Patents

Abstract

PURPOSE:To improve the characteristics and durability of a fuel injection valve, by employing such an arrangement that a stay having a spherical valve body at its top is reciprocated by a movable shaft that is inserted into a fuel passage on the side of an armature of a fixed iron core. CONSTITUTION:A stay 39 having a spherical valve body 37 fixed thereto by way of welding 38 or by other method is disposed on the axis of a conical seat surface 36 formed around a fuel injection port 35 that is formed in a valve seat 34 fixed to the top of a main case 19, in the manner that it is urged onto the end face of an armature 26 by a first spring 40 interposed between the stay 39 and the valve seat 34 and that it is reciprocally movable together with the armature 26 and its projected portion 41 is not moved in a hollow space of armature 26 in a direction perpendicualar to the axis of the armature 26. With such an arrangement, it is enabled to distribute the sealing pressure of the valve body 37 uniformly in the circumferential direction irrespective of whether a valve body 45 is positioned vertically or horizontally.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in electromagnetic fuel injection valves used primarily in electronically controlled fuel injection devices for automobile engines.

Conventionally, in an electromagnetic fuel injection valve, as shown in FIG. 1, a solenoid coil 8 is connected to sealing O-rings 4 and 5 and a ferromagnetic material yoke main body case 2 of the fuel injection valve 1 is made of a ferromagnetic material. The valve housing 9 is attached via a fixed iron core 6 that also serves as a fuel vibrator, and is attached to the tip of the main body case 2 via a non-magnetic spacer 7 and a window closing O-ring 8, which is integrally fixed with an armature 10. needle valve 11
However, the amount of movement is regulated by the surface of the spacer 7 facing the flange surface 12 of the valve 11 and the valve seat surface l4 of the valve housing 9 facing the tip surface 18 of the needle valve 1l, and the distance between the armature lO and the fixed iron core 6 is It is mounted so that it can reciprocate in the axial direction while being biased in the valve closing direction by a spring 15.

In the case of the electromagnetic fuel injection valve 1 configured in this way, in order to smoothly reciprocate the needle valve 11 without vibration, a part of the circumference is placed at equal intervals in front and rear of the 21-dollar valve 11. A support portion 16 is cut to form a fuel flow portion, and a guide hole 17 serves as a fuel passage for the valve nozzle 9.
In order to increase the processing accuracy of the valve housing 9 and to seal the high pressure fuel at the injection port 18 portion of the valve housing 9, it is necessary to
The pulp meat surface 14 of the valve housing 9 and the tip surface 18 of the needle valve 11 must also be processed with high precision.Moreover, both of these materials are stainless steel, which is difficult to process. In addition, the shape of the tip of the needle valve 11 has a complicated shape as shown in the figure because the fuel must be atomized, and this machining is difficult. For these reasons, the manufacturing cost of the electromagnetic fuel injection valve 1 having this valve structure is extremely high.Moreover, the needle valve 11 is integrated with the armature 10, and the weight is, for example, 5g.
Due to the large size and weight of the solenoid coil 8, not only does the responsiveness of the needle valve 1L that corresponds to the on/off operation of the solenoid coil 8 be poor, but also the impact force on the needle valve 11 during on/off operation is large, making the valve more likely to wear out. Disadvantages: The purpose of the present invention is to provide an electromagnetic fuel injection valve that can improve the fuel injection characteristics and durability of the valve while reducing the processing accuracy of the valve parts and simplifying the shape of the parts. The purpose of this is to eliminate the drawbacks of the pre-servant rice.Next, the structure of the first embodiment of the present invention will be explained with reference to FIGS. 2 to 6.

A solenoid coil 20 is attached to a main body case 19 made of a ferromagnetic material that also serves as a yoke, via sealing O-rings 21 and 22 and a fixed iron core 28 made of a ferromagnetic material that also serves as a fuel pipe and a lid body.
A solenoid coil 20 is provided on the outer surface of the lid body of the fixed core 28.
A terminal 24 for connecting to the outside is attached via a synthetic resin connector 25, forms a magnetic path between the main body case 19 and the fixed core 28, and is attracted to the fixed core 28 when the solenoid coil 20 is energized. In the armature 26, a non-magnetic material is integrally crimped with a crimping force F applied from outside of the fixed core 28 to the annular groove 27, as shown in FIG. A movable shaft 80 is reciprocatably inserted into a guide hole 29 of a manufactured bearing 28, and is fixed together by press-fitting as shown in FIG. A circulation groove 81 is formed, and a fuel circulation hole 82 shown in FIGS. 4A and 4B is formed on the fixed core 28 side of the armature 26, and
A fuel circulation groove 88 shown in FIGS. 4A and 4B is formed on the side.

In addition, the valve seat 8 attached to the tip of the main body case 19
As shown in FIG. 8, a stay 89 to which a spherical valve body 87 is fixed by welding 88 or the like is placed on the axis of a conical seat surface 86 formed at the inner periphery of the fuel injection port 85 of No. 4.
The first spring 40 inserted between the pulp sheet 89 and the pulp sheet 84 allows the stay 89 to reciprocate together with the armature 26 while being pressed against the end surface of the armature 26, and the protrusion 41 of the stay 89 fits into the hollow part of the armature 26. By doing so, it was dammed with the axis-perpendicular movement between it and the armature 26 restricted, and was installed in the fuel flow passage of the fixed iron core 28. Between the pipe stopper 42 and the movable shaft 80, A second bridge/gage 48 for moving the armature 26 in the anti-suction direction against the first spring 40 is inserted through the cap sheet 44.

Note that when the bearing 28 is crimped to the fixed core 28, the bearing 2 is on the surface of the fixed core 28 facing the armature 26.
8 is a gap La after adsorption between the armature 26 and the fixed iron core 28 that is such that the armature 26 is not affected by the residual magnetism of the fixed iron core 28 while sufficiently maintaining the suction characteristics of the armature 26 corresponding to the amount of valve lift. 10-10
0 μm・In this example, La=l shown in FIGS. 2 and 5 AK
Qμm protrusion, bearing 28 in the valve closed state shown in FIG.
The dimension between the end face and the end face of the armature 26, ie, the stroke of the armature 26, is set to the valve lift amount LBK.

Next, the operation of this embodiment will be explained.

In the electromagnetic fuel injection valve 45 configured in this way,
The high-pressure fuel that has passed through the filter 46 passes from the fuel flow path of the fixed iron core 28, through the flow groove 81 of the bearing 28, the flow hole 82 and flow groove 88 of the armature 26, and then reaches the recess 47 at the tip of the main body case 19 and the valve seat 84. It reaches inside the formed pulp bousing 48, and in this high pressure fuel supply state,
The spherical surface of the valve body 87 is in pressure contact with the conical seat surface 86 of the valve seat 84 due to the biasing force of the second spring 48 for returning the armature 26, which is stronger than the first spring 40 for opening the valve, so that the fuel is sealed even at high pressure. There is no leakage from the surface 86, and even if there is a misalignment between the axes of the injection port 85, the armature 26, and the movable shaft 80, the stay 89Fi can move slightly in the direction perpendicular to the axis of the armature 26, and the valve body relative to the seal surface 86 Im because the hit of 87 is spherical
! The pressing force by the two springs 4B acts uniformly on the circumference between the self-aligned spherical surface of the valve body 87 and the conical sealing surface 86, ensuring sealing, and as a result of this self-alignment, Even if the electromagnetic fuel injection valve 45 is oriented in any direction vertically or horizontally, the sealing pressure of the valve body 87 can be made uniform over the circumference.

Next, in this valve closed state (the state shown in FIG. 2), the lenoid coil 20 is energized and the armature 26 is attracted against the biasing force of the second spring 48.
is moved by the biasing force of the first spring 40 to a position where the armature 26 with the valve lift amount Ls comes into contact with the end face of the bearing 28 (the state shown in FIG. 6), but the self-aligning state is maintained even during this movement. , and stay 89
The weight of the valve body 87 including the valve body is, for example, 1.0 gr, which is significantly lighter than the 5 gr of the needle pulp 11 shown in FIG. The valve body 87 can be moved in any direction vertically or horizontally by aligning its axis with the axis of the conical sealing surface 86, and in particular, when the electromagnetic fuel injection valve 45 is oriented horizontally. Even in this case, the valve body 37 is not affected by its own weight and the deviation of the axis, and can move with its axis aligned with the fineness of the conical sealing surface 86.
As a result, regardless of the orientation of the electromagnetic fuel injection valve 45, the gap on the circumference between the spherical surface of the valve body 87 and the sealing surface 86 when the solenoid coil 20 is energized and the valve is open is made uniform, and the electromagnetic fuel injection valve 45 is installed. The fuel injection characteristics of the valve 45 can be made constant regardless of the direction in which it is installed, and this is the same even when the solenoid coil 20 is turned on and off and the electromagnetic fuel injection valve 45 is operated and when vibrations occur during engine drive. In particular, since the armature 26 and the valve body 87 are fitted in the axial direction by the protrusion 41 of the stay 89 and the hollow part of the armature 26, even if impactful vibrations from the road surface etc. 87, the valve body 87 does not come off from the armature 26, and since the valve body 87 is extremely light, the fuel injection characteristics of the electromagnetic fuel injection valve 45 are as follows.
Compared to the conventional fuel injection characteristics shown by the dotted line in the figure, the fuel injection characteristics in the low speed and high speed range of the engine can be significantly improved as shown by the solid line in Figure 7. In addition to being able to further lower the idle speed, it is also possible to further increase the maximum engine speed for maximum fuel injection, thereby increasing engine output.

Note that by forming the first spring 40 for biasing the valve body 87 into a conical shape, the influence of the valve body 87's own weight and external vibration can be further eliminated.

Next, the configuration of a second embodiment of the present invention will be explained with reference to FIGS. 8 to 10.

In this case, the first spring 40 in the first embodiment
, valve body 87, stay 89, armature 26, movable shaft 8
0, a spherical valve body 49 is crimped onto the armature 50 as shown in FIGS.
9 attached to the armature 50 together with the movable shaft 51, the bundle is crimped to the armature 54 as shown in FIG. The armature 5 along with the movable shaft 55
The configuration is the same as that of the first embodiment except that the valve structure attached to No. 4 is used. In this case, although the self-aligning function is slightly lower than that of the first embodiment, the valve structure is simpler. By attaching the valve body 52 to the armature 54 through the annular groove 58 shown in FIG. This embodiment has substantially the same functions and effects as the first embodiment, except that the production cost of the electromagnetic fuel injection valve can be further reduced.

Further, in FIG. 11, the fuel flow passage 56 is formed by the distal end recess 58 of the main body case 57 and the valve seat 59 and is equivalent to the flow side.

Next, the effects of the present invention will be explained.〇The first invention is such that a fixed iron core that forms a magnetic path together with the main body case is attached to a ferromagnetic body case that also serves as a yoke, and a solenoid coil is attached to the fixed iron core. The movable shaft, which is fixed integrally with an armature that forms a magnetic path between the main body case and the fixed iron core and is attracted to the fixed iron core when the solenoid coil is energized, is attached to the fixed non-magnetic bearing. The armature is mounted so that it can reciprocate in the suction direction, and the armature is reciprocated by a certain amount corresponding to the amount of valve lift along the axis of the conical seat surface of the valve seat attached to the main body case. A spherical valve element is installed to open and close the injection port on the valve seat communicating with the fuel flow passage, and the armature is further urged in the anti-suction direction between the fixed iron core and the movable iron core to close the valve element. The electromagnetic fuel injection valve has a spring inserted therein which presses against the seat surface of the valve seat when the valve is closed.

As a result, the present invention significantly improves the fuel injection characteristics and durability of pulp while reducing the processing precision of pulp parts and simplifying the shape of the parts.In addition, the production cost of electromagnetic fuel injection valves can be reduced. It also has the effect of significantly reducing

Next, the second invention is a main body case made of a ferromagnetic material that also serves as a yoke to which a solenoid coil is attached, and a fixed iron core that forms a magnetic path between the main body case and the main body, and a non-magnetic material fixed to the fixed iron core. In contrast, a movable shaft that forms a magnetic path between the main body case and the fixed iron core and is fixed integrally with the armature that is attracted to the fixed iron core when the solenoid coil is energized is reciprocated in the direction of attraction of the armature. The nine valve seats are movably attached to the main body case, and movement in a direction perpendicular to the axis between the armature and the armature is restricted on the axis of the conical seat surface of the nine valve seats, and the nine valve seats are attached to the main body case through the first spring and the stay. A spherical valve body is provided which opens and closes the injection port on the pulp 7-toe communicating with the fuel flow path by reciprocating with the armature at a constant rate corresponding to the nozzle lift amount while being pressed against the end face of the armature; The electromagnetic fuel injection valve is provided between the fixed iron core and the movable iron core by urging the armature in a counter-suction direction to force the valve body against the first spring.

As a result, the present invention has the effect of obtaining the same effect as the first invention, and further improving the fuel injection characteristics of the pulp.

[Brief explanation of the drawing]

FIG. 1 is a cutaway front view of the conventional embodiment, FIG. 2 is a left side view of FIG. 4A, FIG. 5B is a left side view of FIG. 5A,
Fig. 6 is a cutaway front view showing the valve open state of the non-embodiment, Fig. 7 is a comparison diagram of the fuel injection characteristics of the conventional embodiment and this embodiment, and Fig. 8 is the valve closed state of the second embodiment of the present invention. A cutaway front view showing W
Fig. J9 is a cutaway front view showing the valve in the open state, Fig. 1θ is a detailed view of a part of the valve on the flow side, and Fig. 11 is a cutaway front view of a partially modified version thereof. 19.57...Body case 20...Solenoid cork 28...Fixed iron core 26.50.54
... Armature 28 ... Bearing 29
...Guide holes 80, 51.55...Movable shaft 81
．． 88... Distribution groove 82... fiA hole 84, 59...
・Valve seat 85...Injection port 86...
・Seat surface 87, 49.52... Valve body 89...
・Stay 40...@1 spring 48...2nd spring 45...Electromagnetic fuel injection valve Patent applicant Aisan Kogyo Co., Ltd. Representative Patent attorney Oka 1) Hidehiko Figure 3 19 (B) (A) Fig. 5 (A) (B) 1l-La'' Fig. 7 → Valve opening time (msec) Fig. 8 Fig. 9z Fig. 11

Claims (1)

[Scope of Claims] (1) A fixed core that forms a busy magnetic path with the main body case is attached to a ferromagnetic body case that also serves as a yoke to which a lunoid coil is attached, and a non-magnetic bearing is fixed to the fixed core. In contrast, a movable shaft that forms a magnetic path between the main body case and the fixed iron core and is fixed integrally with the armature that is attracted to the fixed iron core when the solenoid coil is energized is capable of reciprocating in the attraction direction of the armature. a valve that is attached to the armature and reciprocates with the armature by a certain amount corresponding to the valve wrist amount on the axis of the conical seat surface of the valve seat attached to the main body case and communicates with the fuel flow passage. A spherical valve body for opening and closing the injection port on the seat is attached, and the armature is biased in the anti-suction direction between the fixed iron core and the movable iron core to cause the valve body to close in response to the valve closing. An electromagnetic fuel injection valve characterized by inserting a spring that presses against the seat surface of a valve seat. (2) Place a non-magnetic bearing on the surface of the fixed core facing the armature, while maintaining sufficient suction characteristics of the armature corresponding to the amount of valve lift. This patented injection valve is characterized in that the armature and fixed core protrude in response to the gap after adsorption to a degree that does not cause damage. (8) A fixed iron core that forms a magnetic path together with the core main body case is attached to the ferromagnetic body case that also serves as a yoke, and a non-magnetic bearing fixed to the fixed iron core is connected to the main body case. A movable shaft fixed integrally with the armature that forms a magnetic path with the fixed iron core and is attracted to the fixed iron core when the solenoid coil is energized is mounted so as to be able to reciprocate in the direction of attraction of the armature, and the main body case On the axis of the conical seat surface of the installed valve seat, movement in the direction perpendicular to the axis between the valve seat and the armature is restricted, and the first
A spherical valve body is pressed against the armature end face via a spring and a stay and reciprocates with the armature by a certain amount corresponding to the valve lift amount to open and close the injection port on the valve seat communicating with the fuel flow passage. further provided between the fixed iron core and the movable iron core, a second portion that urges the armature in the anti-suction direction to press the valve body against the seat surface of the valve seat against the first spring.
Electromagnetic fuel injection valve characterized by inserting a spring (4) A non-magnetic bearing is installed on the surface of the fixed core facing the armature, and the armature has suction characteristics that correspond to the amount of valve lift. This patented injection valve is characterized in that, in a sufficiently held state, the armature protrudes in response to the empty space after the armature and the fixed core are attracted to such an extent that the armature is not affected by the residual magnetism of the fixed core. (5) Claim 8, characterized in that the first spring that biases the valve body in the valve opening direction is formed in a conical shape.
The electromagnetic fuel injection valve described in each of Items 1 and 4.