JPH07293387A - Electromagnetic fuel injection valve - Google Patents

Abstract

PURPOSE: To prevent the leakage of fuel and the seizure of a rod by closing the orifice of a nozzle into a control chamber by means of pins or pressurized fuel, and providing a head with a cylindrical cavity for guiding a cylindrical element communicated with a control chamber and adjusting the pins. CONSTITUTION: This fuel injection valve 5 for a diesel engine has a tapered body 6 with an axial cavity 7 in which a control rod 8 forming a moving element is slid, and a nozzle 9 terminating at one or more injection orifices 11 is mounted on the bottom thereof. The nozzle 9 is such that pins 22 coupled to the insides of holes 23, 24 are placed in the body 6 and the nozzle 9 so that the cavity 7 and a line 18 are aligned with a cavity 12 and a line 21, respectively. A regulating needle valve 41 controlled by an electromagnet is provided on the upper portion of the body 6 and a head 49 with a cylindrical cavity 67 guiding a cylindrical element connected to the control chamber 56 of the regulating needle valve 41 and controlling the pins 28 is also provided.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention comprises an injection chamber to which pressurized fuel is supplied and a body mounted to a nozzle having at least one orifice in communication with a regulating needle valve controlled by an electromagnet. Electromagnetic fuel injection valve.

[0002]

BACKGROUND OF THE INVENTION With respect to valves of the type described above, electromagnetically regulated needle valves usually consist of a head having a control chamber which is pressurized by a stopper to close the nozzle. When the adjusting needle valve is open, the pressure in the control chamber drops to move the stopper and open the nozzle.

Various injection valves of the aforementioned type are known, in one of which the head of the regulating needle valve consists of an appendage coaxial with the control chamber, and the injection valve body leads the moving element of the injection valve. And a passage in the head for communication with the control room. The injection valve body is formed in two parts connected to each other, and the rod on the moving element is housed in the seat adjacent to the guide passage by a compression spring,
Pressed into closed position. The head also provides a shaft appendage having an annular groove that forms a flow receiving chamber that communicates with the control chamber via a fuel line.

[0004]

The injection valve has several disadvantages. First, the rod guide passage in the injector body requires precision machining of the body. Secondly, the rod must be stopped inside the guide passage by a correction ring. Third, it is difficult to achieve an effective fuel compression seal between the suction chamber and the guide passage. Fourth, the fuel line remains wide open, even when the regulating needle valve is open, thus causing a large amount of fuel leak that must be repaired later. And last but not least, the lateral thrust created by the spring often causes seizure of the rod.

The object of the present invention is to eliminate the drawbacks generally mentioned above with respect to the known valves and to provide a highly simple and reliable injection valve.

[0006]

According to the present invention, the injection valve comprises a regulating needle valve consisting of a head having a control chamber, an oil supply pipe and an exhaust pipe for supplying pressurized fuel to the control chamber, and the orifice is normally controlled. Stored closed in the chamber by a pin or pressurized fuel, the head also consists of a cylindrical cavity that communicates with the control chamber and guides a cylindrical element that adjusts the pin.

[0007]

1 shows a fuel injection valve for an internal combustion engine and a diesel engine. The injection valve 5 is preferably formed in one piece and has a hollow outward taper with a shaft cavity 7 into which a control rod 8 forming part of the normal moving element of the injection valve 5 slides. It consists of a body 6.
At the bottom, the body 6 attached to the nozzle 9 is
Terminates in one or more injection orifices 11 in communication with.

The body 6 is also an accessory having one or more holes 14 for accommodating one or more supply couplings 16 connected in a known manner to a high pressure fuel supply pump, typically 1200 bar. Provide thing 13. hole
At least one of the 14 communicates with the first sloping conduit 17, in turn with the second conduit 18, and extends substantially along the body 6.

The nozzle 9 in turn provides a small injection chamber 19 in communication with the cavity 12. According to a variant of the invention, upstream of the injection chamber 19, the refueling pipe 18 lowers the pressure in the injection chamber 19 slightly below the pressure line, so as to accelerate the closing of the nozzle at the end of the injection phase, a modified diaphragm is provided. provide. The nozzle 9 is also arranged in the conduit 18 and communicates with the injection chamber 19 by a conduit 21.
I will provide a.

Nozzle 9 is body 6 and nozzle 9 in combination with cavity 12 and conduit 21 by locating a pin 22 coupled to the inside of each hole 23, 24, respectively. 6 are placed on top.

The orifice 11 forms part of the moving element of the injection valve 5 and is kept closed by a stopper consisting of a generally conical pin that slides inside the cavity. The pin 28 is connected to the injection chamber 19 as described in detail later.
The inner pressurized fuel provides a Schorder that acts on it to open the orifice. The pin 28 is connected to the control rod 8 by the pin 31 and the plate 36 or is formed integrally with the control rod 8, in which case the plate is not necessary.

Cavity 7 of body 6 provides a portion 32 generally adjacent nozzle 9 which terminates at its tip in engagement with a Scholder 33, control rod 8 having a small diameter portion 34 in contact with plate 36. I will provide a. A compression spring is arranged between the Schorder 33 and the plate 36, the pressure of which is less than the pressure exerted by the fuel on the Schorder 29, but which contributes to pushing the pin downwards. The body 6 also provides a conduit 38 connecting the portion 32 of the cavity 7 to the exhaust chamber 39 to assist the sliding movement of the control rod 8 inside the cavity 7.
To further provide.

The injection valve 5 also comprises an adjusting needle valve, which is generally designated by 41, and in turn constitutes an electromagnet which controls the anchor 43. The electromagnet 42 is further attached to the body 6 by a ring nut 44 and provides a discharge assembly 46 connected to the fuel tank in a known manner. Anchor 43
Is pressed downward by a spring to provide a radial groove 47 connecting the grind 46 to the exhaust chamber 39, and rigidly connected to the actuator controlling the adjusting needle valve 41, forming a cylindrical stem 48. .

The adjusting needle valve 41 is also provided in the body 6 and the cavity 7.
A head 49 for accommodating a seat 51 formed coaxially with the inside
Composed of. More specifically, the head 49 usually comprises a shoulder 6 of the body 6 and a flange which rests on a cylindrical appendage 54 which accommodates the seat 51 inside. The head 49 provides an axial control chamber 56 in communication with the modified radial oil supply pipe 57 and the modified axial discharge pipe 57, and is advantageously formed from a compacted sintered metal powder.

The oil supply pipe 57 is formed between the side surface of the seat 51 and the side wall of the accessory 54, and the flow receiving chamber is axially limited by two annular seals 61 and 62 mounted between the side wall 54 and the seat 51. Contact 59. The seals 61, 62 are axially separated and rested on the Shoalder 63 of the appendix 54 or the Shoalder 64 of the seat 51, respectively. The receiving chamber 59 communicates with at least one of the holes 14 via a radial conduit 66 in the body 6. Due to the wide surface bond between the outer surface of the appendage 54 and the smaller diameter bottom of the seat 51, and the force of the seat 62 resting on the Schorder 64 perpendicular to the axis of the body 6, from the conduit 66. Any possibility of fuel leaking into seat 51 is prevented.

In accordance with a feature of the invention, the appendage 54 extends downwardly in which the control chamber 56 in which the top cylindrical portion of the control rod 8 slides.
To provide a cylindrical cavity or sheet 67 in communication with. The refueling pipe 57 is located close to the mixing surface 69 between the seat 67 and the control chamber 56, so that the gap between the surface 69 and the top surface 71 of the portion 68 forms an expansion of the control chamber 56. .

The portion 68 preferably has a larger radius than the control rod 8 so that the force exerted by the fuel pressure on the surface 71 is greater than that exerted on the Schorder 29 of the pin 28 and the orifice 11 To enable close. Surface 71
Is the surface of the sheet 67, as indicated by the dotted line in FIG.
Being aligned with 69, surface 69 acts as a stop surface for control rod 8.

The surface 68 provides a large number of grooves 72, such as radial grooves, so that the area 68 suppresses the overall elimination of the gap between it and the surface 69, and thereby the area 68 of the control rod 8.
The side of the portion 68 partially closes the fuel line 57, thus blocking the flow of fuel towards the drain line 58, and the regulating needle valve 41 is a substantially three-way valve. Work as.

The head 49 is fixed to the body 6 by a ring nut 73 screwed into the threaded seat of the body 6 and has a bell shape with a depression 76 (FIG. 2) communicating with the exhaust chamber through a hole 77. Acting on member 74. The bell-shaped member 74 is integral with the sleeve 78 for the guide stem 48, and the exhaust pipe 58 in the head 49 terminates at the top with a conical portion 79 connected by a ball-type stop controlled by the stem 48. To do.

In the modification of FIG. 3, the exhaust pipe 58 is a plate.
It is engaged by a stopper comprised of 82, whereby the conical portion of conduit 58 is eliminated and the upper surface of flange 52 provides an annular groove to increase the volume of the chamber created by depletion 76.

The described injection valve operates as follows.

Since the electromagnet is normally deenergized, the anchor 43 is supported by its spring in the position of FIG. 1 and the ball 81 or plate 82 (FIGS. 2 and 3).
Is arranged by the stem 48 to close the exhaust pipe 58, the control chamber 56 therefore overcomes the pressure exerted on the Schorder 29 together with the pressure exerted by the spring 37 and the control rod 8 the pin 28. The top 27 closes the orifice 11 as it is lowered with it.

When the electromagnet 42 is energized, the anchor 43 rises and the stem 48 causes the stopper 81 or
Opening 82 and the fuel pressure in chamber 56 opens regulating needle valve 41 so that it flows through hole 77 and into the exhaust chamber 39 back into the tank.

At this point, the fuel pressure in the injection chamber 19 is controlled by the control chamber 56.
The sum of the pressure remaining inside and the pressure exerted by the spring 37 makes the pin 28, together with the control rod 8, lift up. This means that the small volume chamber 19 upstream from the injection orifice is
Even with respect to, i.e. without accumulating additional fuel, and so as to reduce the pressure under the Schorder 29, the cone of the exhaust pipe 56 giving a considerable outflow and virtually eliminating the pressure in the chamber 56. Guaranteed by the force of the part and the ball stopper 81. If the control rod 8 is stopped against the surface 69 of the seat 67, the tip 27 of the pin 28 will cause the orifice 11 to move.
As the fuel in chamber 19 is injected into the engine, portion 68 of control rod 8 partially closes fuel line 57, thus minimizing the amount of fuel provided through control chamber 56 to the exhaust chamber. .

When the electromagnet 42 is deenergized, the anchor 43 is moved rearward and downward by its spring so as to close the exhaust pipe 58 and the pressurized fuel supplied by the conduit 57 via the groove 72 is chambered. If pressure is restored inside 56 and the pressure in chamber 56 exceeds the pressure exerted on the Schorder with the pressure of spring 37,
The movable parts 8, 28 approach the orifice 11 and move downward again. As well as the combined action of the small chamber upstream from the injection hole and the modified diaphragm along the oil supply pipe reduces the extra load on the control rod 8 as well as the rod 8 and pin.
It provides a trouble-free downward movement of the mobile element without the essential difference required within the diameter of the portion 68 of the 28 Scholder 29.

In the variant of FIG. 4, the stem of the anchor 43
The guide of 48 is formed in the head 49 and consists of a cylindrical recess coaxial with the cavity 67, thereby eliminating the bell-shaped member 74 (FIG. 1), which contains the exhaust pipe 58. A diaphragm 84 is provided, and the control chamber consists solely of the gap between the upper surface 71 of the portion 68 and the stop surface 69 of the cylindrical sheet 67.

The cylindrical recess 83 provides an axial groove 85 to allow communication between the control chamber and the exhaust chamber 39, and in the same manner as described above, a ball 81 or plate 82 type stopper for the exhaust pipe 58. The operation of the modification of FIG. 4 which naturally applies to the above is the same as that described with reference to FIGS.

In the modification of FIG. 5, the appendix 54 is a receiving chamber 59.
And a control chamber 59, a refueling pipe 57 comprises one or more conduits 57a, which are advantageously of small diameter, for direct communication. And the groove 72 on the part 68
Stop surface 69 of seat 67 and surface 71 of portion 68 at
The corn has a truncated shape with a tapered tip at different angles. More specifically, the ideal cone of surface 71 gives a smaller tip angle than that of surface 69. A modification of FIG. 5 is that the control chamber 56 is changed to the exhaust chamber by a completely closed refueling pipe 57.
The amount of fuel supplied to 39 is minimized, and the fuel flow rate is determined by the small diameter oil supply pipe 57a.

It will be apparent to those skilled in the art that modifications can be made to the injection valve described herein without departing from the scope of the invention. For example, spring 37 is plate 36
Will be attached directly to the 28 pieces on the other side of the
The movable elements 8, 28 are made in one piece and in order to avoid bending in the case of extremely long control rods 8,
It can be given the same diameter as section 68.

[0030]

The advantages of the electromagnetic fuel injection valve according to the present invention are apparent from the above description. In particular it eliminates the need for precision machining of the seat 51 and provides a simple machining of the body 6, and by closing the refueling pipe 57 the amount of fuel flowed along the conduit 58 at each injection cycle is reduced. The sling 37 through the plate 36
The fact that it acts directly on the pin 28 as opposed to the control rod 8 reduces the possibility that the cylindrical portion 68 of the control rod 8 will burn the slidable sheet 51 inside. Finally, the fuel leakage from the flow receiving chamber 59 through the seat 67 never impairs the efficiency of the electromagnetic fuel injection valve.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an injection valve according to an embodiment of the present invention.

FIG. 2 is a detailed vertical sectional view of an essential part of the above.

3 is a longitudinal sectional view showing another embodiment of FIG. 2 above.

FIG. 4 is a vertical sectional view showing an injection valve of another embodiment of the present invention.

FIG. 5 is a detailed vertical cross-sectional view of main parts showing another embodiment of FIG. 1 above.

[Explanation of symbols] 6 body 8 control rod 9 nozzle 11 orifice 17, 18 conduit 19 injection chamber 28 pin 37 compression spring 39 exhaust chamber 41 adjusting needle valve 42 electromagnet 43 anchor 48 control element 49 head 56 control chamber 57 oil supply pipe 58 exhaust Tube 59 Fuel receiving chamber 67 Cylindrical cavity 71 End surface 72,85 Groove 81 Ball 82 Disc 83 Guide member 84, 90 Diaphragm

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mario Ricco Italy, 70125 Bari, Via Fellannini, 10 (72) Inventor Giovanni Bruni Italy, 70126 Bari, Via Gentieri, 58 (72) Inventor Sistou Luigi de Mathias Italy, 70026 Moudougno, Via Syracuse, 4

Claims (13)

[Claims] 1. A nozzle having at least one orifice in communication with an injection chamber (19) supplied with pressurized fuel.
Body (6) attached to (9), adjusting needle valve (41) controlled by electromagnet, control chamber (56), oil supply pipe (57) for supplying pressurized fuel to the control chamber (56), and exhaust It consists of the regulating needle valve consisting of the head (49) with the pipe (58), the pin (28) and the orifice (11) normally closed by the pressurized fuel inside the control chamber (56). The head (49) also comprises a cylindrical cavity (67) communicating with the control chamber (56) and guiding a cylindrical element controlling the pin (28). Injection valve. 2. The cavity (67) is coaxial with the exhaust pipe (58) and the control chamber (56) and the oil supply pipe (57) is arranged radially in the cavity (67). 1. The electromagnetic fuel injection valve according to 1. 3. A cylindrical element when the exhaust pipe (58) is open.
The electromagnetic fuel injection valve according to claim 2, wherein the fuel supply pipe (57) is partially closed by the (68). 4. A groove for securing a remaining gap in a cavity (67) in which a cylindrical element (68) communicates with a fueling pipe (57).
An electromagnetic fuel injection valve according to claim 3, characterized in that it provides a terminal surface (71) having (72). 5. A cylindrical element (68) is provided on the end face (6) of the cavity (67).
When facing the 9), the end surface (71) in the shape of the corn cut off is given, and the end surface (69) also has the shape cut off the end of the corn, but the cylindrical element (68) The taper at a different angle compared to the end face (71), and the head (49) connecting the control chamber (56) to the annular fuel receiving chamber.
4. The electromagnetic fuel injection valve according to claim 3, further comprising at least one oil supply pipe (57a) directly connected to the (59). 6. The exhaust pipe (58) is an anchor (4) of an electromagnet (42).
It is connected to the exhaust chamber (39) by activating the control element (48) essential to 3), and the control element (48) is connected to the head (49).
And means (78,83) axially integral and coaxial with the cavity (67)
Guided by:
The electromagnetic fuel injection valve according to any one of 1. 7. The guide means (78, 83) is composed of a cylindrical guide member (83) integrated with the head (49), and the exhaust chamber (39) is at least one of the guide members (83). 7. The electromagnetic fuel injection valve according to claim 6, wherein the electromagnetic fuel injection valve comprises a groove (85). 8. A guide member (83) comprises a cylindrical recess (83) separated from a cavity (67) by a diaphragm (84) supporting an exhaust pipe (58), the control chamber being said cavity. (6
The electromagnetic fuel injection valve according to claim 7, wherein the electromagnetic fuel injection valve is formed by a part of (7). 9. The body (6) comprises a moving element (8, 28) having a narrow tip and comprising a control rod (8) having a pin (28) and a cylindrical element (68) therein. The axial seats (7, 12) to be slid on, the seat (51) being coaxial with the cavity (67) and defining the annular fuel receiving chamber (59) connected to the fuel pipe (57). Accommodating a pair of annular seals (61, 62), one (62) of the seals (61, 62) resting on the flat Scholder (64) of the seat (51), 61, 6
2) Others (61) are flat shawlers (6) with heads (49).
3) The electromagnetic fuel injection valve according to any one of claims 6 to 8, which is mounted above. 10. The movable element (8, 28) is a compression spring.
Placed in close proximity with the aid of (37), the pin (28) is a control rod
Electromagnetic according to claim 9, characterized in that it is coaxial with (8) and the spring (37) is housed in a seat (32) on the pin (28) close to the injection chamber (19). Fuel injection valve. 11. The control element (48) acts on the exhaust pipe (58) in the form of a ball (81) or a disc (82) via a stop, according to one of claims 6 to 10. The electromagnetic fuel injection valve according to claim 1. 12. Diaphragm with modified injection chamber (19).
The electromagnetic fuel injection valve according to any one of claims 1 to 11, wherein the electromagnetic fuel injection valve is connected to a pressurized fuel oil supply pipe through a conduit (17, 18) having (90). 13. The electromagnetic fuel injection valve according to claim 1, wherein the size of the injection chamber (19) is limited.