JPH07103837B2 - Electromagnetic fuel injection valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuel injection valve for an internal combustion engine, and more particularly to an electromagnetic fuel injection valve.

[Conventional technology]

Conventional electromagnetic fuel injection valves are disclosed in Japanese Patent Application No. Sho 58-186147 (No. Sho 60-92766) and No. Sho 58-199526 (No. Sho 60-110).
No. 673), the guide part for the movement of the movable part is lengthened to improve the guiding accuracy, and the movable part is attracted to the core inside the sliding surface of the guide part.

In addition, as described in Japanese Patent Application No. 57-169556 (Japanese Utility Model Application Laid-Open No. 59-73572) and Japanese Patent Application Laid-Open No. 61-11450, the movable part is provided with a core on the outside of the sliding surface of the guide part or at a place apart from it. It is configured to suck into.

[Problems to be solved by the invention]

In the former configuration, the magnetic circuit that attracts the movable part to the core traverses the sliding surface of the guide part, and if sliding is repeated and the sliding surface becomes worn and uneven, magnetic characteristics deteriorate. However, there is a problem that the suction force is reduced and the responsiveness of the movable part is deteriorated.

Further, in the latter configuration, the magnetic circuit for attracting the movable portion to the core does not cross the sliding surface of the guide portion, but the armature of the movable portion and the core come into contact with each other to stop the movement of the movable portion. The surface serves as the attracting surface of the magnetic circuit, and if this surface is worn and uneven due to repeated contact, the magnetic characteristics deteriorate, the attractive force decreases, and the responsiveness of the movable part deteriorates. There was a problem.

[Means for solving problems]

The purpose of the above is to provide the guide part of the movable part at two locations on the valve body side and the armature side, and to make the armature side guide part a cylindrical body of non-magnetic material. The outer peripheral surface of this guide part and the inner peripheral surface of the cylindrical core The guide part is installed inside the core so that and slide, and a suction force is generated between the core and the armature on the outer peripheral side of the guide part, and between the core and the armature. This can be achieved by providing the movable portion with a stopper portion that stops the axial movement of the movable portion caused by the suction force so that a gap is generated.

[Action]

The electromagnetic fuel injection valve of the present invention configured as described above,
At the outer peripheral side of the armature side guide part, a suction force is generated between the core and the armature, so the magnetic circuit does not cross the sliding surface of the guide part, and sliding is repeated and the sliding surface wears. Even if irregularities are formed, it is possible to prevent the problem that the magnetic characteristics are deteriorated, the attractive force is reduced, and the responsiveness of the movable portion is deteriorated. Furthermore, when the movable part moves in the axial direction, it stops at the stopper part, and a gap is created on the attraction surface of the magnetic circuit between the core and the armature, so this surface is not worn and no unevenness occurs, and the magnetic characteristics It is possible to prevent the deterioration of the responsiveness of the movable part due to the deterioration of the magnetic field and the decrease of the suction force.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3. The magnetic circuit consists of core 2, yoke 3, and plunger 4.
It consists of a plunger 4 and a rod 5 inside the core 2.
A spring 9 for pressing a mover composed of a ball valve 6 and a seat surface 8 of a valve guide 7, a spring adjuster 10 for adjusting a load of the spring 9, a core 2 and an adjuster 10.
An O-ring 11 is provided to prevent the fuel from flowing out through the gap between them. In addition, between the core 2 and the yoke 3,
An O-ring 12 for preventing fuel from flowing out from the gap between the core 2 and the yoke 3 and a coil 15 for exciting a magnetic circuit are wound around a bobbin 13, and the outside thereof is molded with a plastic material 14. The coil assembly 16 composed of these is inserted into the collar hole 17 of the core 2, and the O-ring 19 between the tongue 18 and the core 2 and the mold (hereinafter referred to as the yoke mold) 19 outside the injection valve 1 are injected at the time of molding. A collar 20 is provided so as not to enter the inside of the valve 1, and a convex portion 21, a gap 22 with the core 2 and an upper portion are provided on the outer periphery to prevent bubbles in the fuel from entering the inflow side. A passage 23 and a lower passage 24 are provided. The yoke 3 has an O-ring 26 and an O-ring 26 for preventing fuel from flowing out from a gap between the injection valve 1 and the socket 25.
A groove 27 for holding the fuel, an inflow passage 28 for fuel to flow in, and an outflow passage 29 for outflowing air trapped in the injection valve, a plunger receiving portion 30 for receiving a movable portion, a stopper 31 and a valve for receiving the valve guide 7. It has a guide receiving portion 32. Further, on the outer periphery of the yoke 3, a filter 33 for preventing dust and foreign matter from entering the fuel and piping, a tank 34 for transmitting a signal from the control unit to the coil 15, and a yoke mold 19 forming a mold connector 35 surrounding the tank 34. Is provided. In the movable part, the plunger 4, the rod 5, the ball valve 6 and the guide ring 36 made of a non-magnetic material are integrally formed. The guide ring 36 is the inner diameter 37 of the core 2 and the ball valve 6 is the guide part 38 of the valve guide 7. Will be guided in. Valve guide 7
Includes a guide surface 38 for guiding the ball valve 6 and the ball valve 6
Seat surface 8 for seating a swirl and swirl orifice receiving part for receiving swirl orifice 39 for atomizing fuel.
An O-ring receiving portion 54 is provided for receiving the O-ring 41 for sealing the fuel between the socket 40 and the socket 25.

The above-mentioned components are roughly divided into a yoke, a mold bumper portion, and a valve guide bumper portion, and the respective assembling methods will be described below. The yoke mold is a coil assembly
16 is inserted into the collar hole 17 of the core 2 after attaching the tongue 18 portion of the coil assembly 16 to the O-ring 19, and the collar 20 is inserted from above the tongue 18. After that, the O-ring 12 is attached to the yoke 3 and the core abutment surface 43 on the inner circumference of the yoke 3 is pressed by the metal flow employment 42, and the yoke 3 is inserted into the groove 44 provided in the core 2.
The so-called metal flow is performed in which the material of is pushed in and fixed by the tension force. (FIG. 2) At that time, since the movable part slides by guiding at two places, the guide surface 38 of the valve guide 7 and the inner diameter 37 of the core 2, the outer diameter of the valve guide 7 and the guide surface 38 Of course, the coaxiality is important, but the coaxiality between the valve guide 7 receiving portion 32 of the yoke 3 and the inner diameter 37 of the core 2 is important. Therefore, in the hiring 45 shown in FIG. 2, the receiving portion 32 of the valve guide 7 and the inner diameter 37 of the core 2 are accurately received to perform metal flow. After that, tonshi 18 to tonshi 34
Then, the yoke mold 19 is molded by fixing it by crimping, soldering, welding or the like. Next, in the valve guide bushing portion, the ball valve 6 and the quench-hardened rod 5 are welded by resistance welding or laser welding,
The rod 5 and the plunger 4 are fixed by metal flow using the groove 46 provided in the rod 5. Further, as shown in FIG. 3, the coupling between the guide ring 36 and the plunger 4 receives the ball valve side surface 47 of the plunger 4 and uses the metal flow employment 48 to press the guide ring contact portion 49 of the plunger 4. , Metal flow that gives tension to the guide ring. Then, the ball valve side surface 50 is ground at four places to form a fuel passage. The stroke of the movable part is determined by the distance between the rod neck receiving surface 51 and the stopper 31, and the movable part and the valve guide 7 are combined and measured.
52 Or, adjust the rod neck receiving surface 51 by grinding.

As described above, after assembling and adjusting the valve guide bumper portion and the yoke mold bumper portion, the valve guide bumper portion is inserted into the valve guide receiving portion 32 of the yoke 3 together with the stopper 31, and the groove 53 provided in the valve guide 7 is inserted. Use and fix with metal flow. At this time, the stopper 31 has a thickness having a predetermined air gear so that the plunger 4 and the core 2 do not come into direct contact with each other when the movable portion is sucked.
Next, from the direction opposite to the valve guide 7 of the yoke mold bunk part, insert the adjuster 10 with the spring 9 and the O-ring 11 inside the core 2, and install the filter 33 and the O-ring 26 on the outer periphery of the yoke 3. Install it, put it in the same shape as the socket 25, and start the injection amount test. In the injection amount test, first, measure the movable part with a full stroke, select the swirl orifice 39 so that the injection amount at that time becomes the specified injection amount, and fix it to the swirl orifice receiving part 40 with a metal flow. To do. After that, the responsiveness of the movable portion is changed by the load of the spring so that the injection amount of the constant valve opening time becomes a prescribed injection amount at a constant cycle, and the upper protrusion 55 of the core 2 is axially moved from the outside. Press, Asia part 56
Fix by cutting the material into.

The operation of the injection valve having the above structure will be described. Injection valve 1
Is for injecting fuel by opening and closing a valve seat by an electric ON-OFF signal, and the electric signal is given to the coil 15 as a pulse. When an electric current is applied to the coil 15, a magnetic circuit is formed by the core 2, the yoke 3 and the plunger 4, and the plunger 4 is formed on the outer peripheral side of the guide ring 36.
Is sucked to the side. The plunger 4 is connected to the ball valve 6 by a rod 5 which communicates the inside with the upper and lower parts thereof. When the plunger 4 moves, the ball valve 6 also moves, and the seat surface 8 of the valve guide 7 moves. To open the valve.
Then, the rod neck receiving surface 51 of the rod 5 and the stopper 31 come into contact with each other to stop the movable portion. At this time, there is a gap between the suction surfaces of the core 2 and the plunger 4, and there is no contact.

The fuel is pressurized and adjusted by the fuel pump and the fuel pressure regulator, and flows into the socket 25 from the fuel gear rally 57,
It flows into the injection valve 1 through the inflow passage 28, and the coil assembly 16
Through the lower passage 24, the outer periphery of the plunger 4, the gap between the stopper 31 and the rod 5, and the outer portion 50 of the ball valve 6 to the seat portion, and the swirl hole of the swirl orifice 39 when the valve is opened.
It is injected into the engine through 58.

As described above, since the movable portion of the main injection valve 1 has the guide portion as the outer periphery of the ball valve 6 and the outer periphery of the guide ring 36 fixed to the inner diameter of the plunger 4, the overall length is shortened to reduce the weight of the movable portion. Is a structure that can secure the guide length. Moreover, since the guide ring 36 is a non-magnetic material, the attraction force of the core 2 does not act, and the force that hinders sliding does not act.
Therefore, the suction of the movable part is accelerated, the responsiveness is improved, and the dynamic range of the fuel injection amount is expanded. Further, since the magnetic circuit for attracting the plunger 4 by the core 2 is on the outer peripheral side of the guide ring 36 and does not traverse this sliding surface, this surface is not worn and no unevenness occurs.
It is possible to prevent deterioration of responsiveness of the movable part due to deterioration of magnetic properties and decrease of attractive force, and it is possible to obtain an effect that reproducibility is improved and durability is also improved. Further, since the ball valve 6 has a high centripetal property, the clearance of each guide portion can be made rougher than before, and positioning can be performed with high accuracy at the time of assembly without making the processing accuracy of a single item as difficult as before. Since it uses a metal flow that can be fixed, the processing time can be greatly reduced.

As described above, in the mover of this embodiment, the ball valve is guided by the center guide hole of the valve guide, and the non-magnetic material provided between the plunger and the core provided on the side opposite to the ball valve via the rod. Even if the movable part is made smaller and lighter in order to widen the dynamic range, the guide length can be secured and the movable part can be prevented from collapsing with respect to the axis of the injection valve. Due to the weight reduction, the suction of the movable part becomes faster, the response is improved, and the dynamic range of the injection amount can be expanded. Further, if the fall can be prevented, the movement of the movable portion is stabilized, the reproducibility of the injection amount characteristic is improved, and the uneven load due to the fall is eliminated, so that the abnormal wear of the guide portion is eliminated and the durability is improved.

The guide ring does not necessarily have to be cylindrical, and may have at least three sliding parts on the circumference.

Furthermore, the guide ring can be configured as a sliding layer made of a non-magnetic material formed on the outer periphery of the armature itself. In this case, the layer may be formed not only by press-fitting the ring, but also by coating.

〔The invention's effect〕

According to the present invention, the guide portion of the movable portion is provided at two locations on the valve body side and the armature side, and the guide portion on the armature side is a tubular body made of a non-magnetic material. The guide part is installed inside the core so as to slide with the peripheral surface, and a suction force is generated between the core and the armature on the outer peripheral side of the guide part. With the configuration in which the movable portion is provided with a stopper portion that stops the axial movement of the movable portion caused by suction so that a gap is created between them, the magnetic circuit does not cross the sliding portion of the guide portion, Furthermore, when the movable part moves in the axial direction, it stops at the stopper part, and a gap is created on the attraction surface of the magnetic circuit between the core and the armature, so that this surface is not worn and no unevenness occurs, and therefore, Deterioration of magnetic properties, suction There is an effect that it is possible to prevent the deterioration of the response of the movable part due to the decrease.

[Brief description of drawings]

FIG. 1 is a sectional view of an electromagnetic fuel injection valve according to an embodiment of the present invention, FIG. 2 is a drawing for explaining an assembly structure of a yoke and a core, and FIG. 3 is an assembly structure of a mover. It is a drawing for doing. 1 ... Injection valve, 2 ... Core, 3 ... Yoke, 4 ... Plunger,
5 ... Rod, 6 ... Ball valve, 7 ... Valve guide, 9 ... Spring, 36 ... Guide ring, 30 ... Swirl orifice.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masahiro Soma Masahiro Soma 3085, Higashi Ishikawa Nishikouchi, Katsuta City, Ibaraki Prefecture 5305 Hitachi Automotive Engineering Co., Ltd. (72) Tokuo Kosuge 2520 Takaba, Katsuta City, Ibaraki Prefecture Address: Hitachi, Ltd., Sawa Plant (72) Inventor, Toru Ishikawa, 2520, Takaba, Katsuta, Ibaraki Prefecture, Takaba, Ltd .: 72, Inventor, Sawa, Hitachi, Ltd., Naonobu Kanamaru, 2520, Takaba, Katsuta, Ibaraki, Hitachi, Ltd. Factory Sawa Factory (72) Inventor Mizuho Yokoyama 2520 Takaba, Katsuta City, Ibaraki Pref. Sawa Factory Hitachi, Ltd. (56) References 60-110673 (JP, U) Actual 59-73572 JP, U) Actually open 60-92766 (JP, U)

Claims (1)

[Claims] 1. A movable member having a valve seat, a valve body on one side and an armature made of a magnetic material on the other side, a cylindrical core having a surface facing the armature, and arranged around the cylindrical core. An electromagnetic coil is provided, and when the electromagnetic coil is energized, a suction force is generated between the cylindrical core and the armature, and the movable member is moved by the suction force, so that a space between the valve seat and the valve body is generated. And a fuel inlet is provided in a direction lateral to the axial movement direction of the movable member. And a fuel passage that connects the valve body and a guide portion that guides the axial movement of the movable member, the guide portion including a first guide portion that guides the armature side of the movable member, Moving member valve In an electromagnetic fuel injection valve including a second guide portion that guides the body side, the first guide portion is a tubular body made of a non-magnetic material, and an inner peripheral surface of the first guide portion and an inner portion of the tubular core. The first guide portion is installed inside the tubular core so as to slide with the peripheral surface, and a suction force is provided between the tubular core and the armature outside the outer peripheral portion of the first guide portion. So that a gap is created between the tubular core and the armature,
An electromagnetic fuel injection valve, wherein a stopper portion for stopping the axial movement of the movable member caused by the suction force is provided on the movable member.