JPS60164659A - Electromagnetic type fuel injection valve - Google Patents

Abstract

PURPOSE:To facilitate the coaxial fixation of a needle valve and a movable core under the high precision condition and restrain the loosening of coupled parts due to repetitive operations by elongating sufficiently the length of a hollow shaft of the needle valve compared with the diameter of a core hole. CONSTITUTION:A hollow shaft 25 is forced into a core hole 21 while a projection 35 is fitted into a groove 22. Here, since the thickness of the projection 35 fitted into the groove 22 is slightly larger than the depth of the groove 22, the projection 35 projects slightly from the side 39 of a shaft portion 3a under the fitted condition. The projecting portion 35a of the projection 35 is plastically deformed by a punch 36 so that a pushed-out core member enters a stop portion 23. Thus, a needle valve 3 is integrally coupled with a movable core 20 to move axially in one unit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic fuel injection valve particularly suitable for use as a fuel supply device for an internal combustion engine.

[Prior art]

In conventional electromagnetic fuel injection valves, the structure of the joint between the needle valve and the movable core of the injector was such that the needle valve was screwed into the movable core and fixed with adhesive. There is a drawback that the agent spreads and reaches the needle valve guide portion, impeding movement of the needle valve.

In order to overcome this drawback, there is also a method of providing a concavo-convex part consisting of an annular groove and a raised part on the needle valve, and pressing the core hole of the movable core with the concave-convex part, but with this method,
When the concavo-convex portion and the core hole are crimped, there is a risk that the needle valve and the movable core will not be arranged coaxially, and as the needle valve is repeatedly operated, the crimped portion may become loose.

(Object of the Invention) An object of the present invention is to facilitate coaxially fixing a needle valve and a movable core in a highly accurate state, and to prevent the connection between the needle valve and the movable core by repeated operation of the needle valve. The goal is to prevent loosening.

In order to achieve the above object, the present invention includes: a hollow shaft that protrudes from the end face of the needle valve and has a space through which fluid can flow; and grooves provided at multiple locations on the side surface of the needle valve from the end face of the needle valve; A needle valve having a locking portion provided in the groove has a core hole that connects with the hollow shaft, and a protrusion that engages with the groove and has a thickness slightly larger than the groove depth of the groove. The movable core is connected to a movable core having a movable core, and the interlocking portion between the groove and the protrusion is plastically deformed, so that a part of the protrusion is coupled to the locking part.

〔Example〕

Part 1 and 2 of the first embodiment of the present invention +8+
, (bl, (Explained based on C1.

In FIG. 1, numeral 1 denotes a housing, and a nozzle body 2 is held at the lower end by a constriction 1a.

A needle valve 3 is housed in the nozzle body 2 so as to be movable in the axial direction. When the needle valve 3 is seated on the valve seat 4 of the nozzle body 2, the fuel injection hole 5 is closed. When it leaves the seat 4, the fuel injection hole 5 opens.

A tubular iron core 6 is located in the center of the housing l.
The iron core 6 is fixed to the housing l by tightening the upper end 1b of the housing l.

An electromagnetic coil 8 wound around a spool 7 is housed in an annular space formed between the housing 1 and the iron core 6. The spool 7 is fitted into the housing l and the iron core 6 through O-rings 9 and 10 in a fluid-tight manner. The electromagnetic coil 8 is connected to a terminal 12 installed in a synthetic resin connector ll integrated with the housing 1. This terminal 12 is connected to an electronic control device 13 such as a computer, receives current pulses from the electronic control device 13, and transmits the current pulses to the electromagnetic coil 8.

The upper end of the iron core 6 is a connector pipe 14 connected to a fuel supply pipe (not shown), and fuel adjusted to a predetermined pressure is supplied to the connector pipe 14. The fuel passes through a filter 15 and enters a fuel passage 1 provided in the center of the iron core 6.
7. An adjustment pipe 18 is housed in the central space of the iron core 6, and the fuel passage 17 is substantially the interior space of the adjustment pipe 18. The adjustment pipe 18 is fixed to the iron core 6 by tightening the upper part 6a of the iron core 6. The upper end of a spring 19 is in contact with the lower end of this adjustment pipe 18. The lower end of the spring 19 is in contact with the upper end of the movable core 20. Note that the cent load of the spring 19 is set by adjusting the position where the adjust pipe 18 is fixed to the iron core 6.

The movable core 20 is housed so as to be freely movable in the axial direction within the housing l, and a circular core hole 21 is formed in the movable core 20.

Regarding the connection between the needle valve 3 and the movable core 20, FIG.
l, (bl, (explained in C1).

The shaft portion 3a of the needle valve 3 is provided with grooves 22 at two locations in the axial direction from the end surface 24 of the shaft portion 3a. One locking portion 23 is provided on each side of 22. Further, from the end surface 24 of the shaft portion 3a, it has a length comparable to that of the core hole 21 of the movable core 20, and the diameter of the core hole 21,
A cylindrical hollow shaft 25 having the same outer diameter and a space through which fluid can flow protrudes. Movable core 20
A protrusion 35 is provided at the end 26 of the protrusion 35 which engages with the groove 22 and has an overall thickness slightly larger than the groove depth of the groove 22. In such a configuration, the hollow shaft 2
．． 5 is press-fitted into the core hole 21, and at the same time, the protrusion 35 is fitted into the groove 22. Here, the protrusion 35 fitted into the groove 22 has a thickness equal to or smaller than that of the groove 22.
Since the depth of the protrusion 35 is slightly larger than the depth of the two grooves, the protrusion 35 is slightly protruded from the side surface 39 of the shaft portion 3a in the fitted state, and the protrusion 35a of the protrusion 35 is plastically deformed by the punch 36. As a result, the extruded core member enters the locking portion 23.

As a result, the needle valve 3 and the movable core 20 are integrally coupled and move together in the axial direction.

Referring again to FIG. 1, the needle valve 3 is provided with a flange 27 serving as a stopper, and guide portions 28 and 29 are formed below this flange 27. These guide parts 28 and 29 slide with respect to the sliding hole 30 of the nozzle body 2 through a gap. In addition, these guide portions 28.
A fuel passage 31 is secured between the two. The needle valve 3 is passed through the through hole 33 of the spacer 32 via a gap. Further, when the needle valve 3 is moved (lifted) upward, the flange 27 hits the spacer 32, and the amount of lift is regulated.

Note that 34 is an O-ring provided between the nozzle body 2 and the housing 1. Also, 37.38 is the connector pipe 14
These are a fuel passage provided in the fuel path from the fuel injection hole 5 to the fuel injection hole 5, and a fuel passage hole.

In the electric value type fuel injection valve having the above-described configuration, fuel pressurized to a constant pressure is supplied through the connector pipe 14. This fuel passes through the filter 15 to the adjustment pipe 1
It passes through the fuel passage 17 in the needle valve 3, reaches around the spring 19, and passes through the hollow shaft 25 of the needle valve 3, the fuel passage 37 inside the shaft part 3a, and the guide part 28 and the guide part 29.
The fuel passes through the fuel illumination hole 38 provided between the guide portion 28, 29 and the sliding hole 30, and further reaches the valve seat 4 through the fuel passage 31, which is the gap between the guide portion 28, 29 and the sliding hole 30.

When the electric current pulse is not supplied to the electromagnetic coil 8 from the electronic control bag ft 13, the iron core 6 is not magnetized, so the movable core 20 is pushed down by the pressing force of the spring 19, and the needle valve 3 is moved to the valve seat 4. The fuel injection valve 5 is closed in close contact with the fuel injection valve 5.

When a current pulse is applied from the electronic control device 13 to the electromagnetic coil 8, the iron core 6 is magnetized, so that the movable core 20 is attracted to the iron core 6 against the urging force of the spring 19.

For this reason, the needle valve 3 connected to the movable core 20 is lifted and is separated from the valve seat 4, so the fuel injection hole 5
opens, and the fuel that has reached just before the fuel injection hole 5 is injected.

When the application of the current pulse to the electromagnetic coil 8 ends,
Since the magnetization of the iron core 6 disappears, the attraction force of the iron core 6 to 720 is lost, and the movable core 20 is moved downward under the pressure of the spring 19, and the needle valve 3 is seated on the valve seat 4, so that the fuel is not absorbed. The injection hole 5 is closed, thereby ending fuel injection.

Next, FIG. 3(a) shows a second embodiment of the present invention.

To) will be explained. ' In this practical example, the stop part 23 is attached to the groove part 22.
Two on each side of the shaft 3a are provided along the side surface 39 of the shaft portion 3a in a direction perpendicular to the groove portion 22. Also,
The protrusion 35 protruding from the end 26 of the movable core 20 has a
Two raised portions 35a are provided. Note that the position of this raised portion 35a is provided at a position that coincides with the locking portion 23 formed in the groove portion 22 when the projection portion 35 engages with the groove portion 22.

In the above configuration, similarly to the first embodiment, the movable core 2
0 and the needle valve 3 are connected so that the protruding part 35 and the groove part 22 engage with each other, and the raised part 35a is plastically deformed by the punch 36 so that it enters the locking part 23, and the movable core 20 and the needle valve 3 are connected. combine.

Note that the other configurations and operations are the same as in the first embodiment.

Next, FIG. 4(a) shows a third embodiment of the present invention.

佽) explains.

In this embodiment, a rectangular locking part 23 wider than the groove part 22 is provided at the tip of the groove part 22, and a protruding part 3
5 has a raised portion 35a formed at a position corresponding to the locking portion 23 when engaging with the groove portion 22.

Note that the connection between the movable core 20 and the needle valve 3, other configurations, and operations are the same as in the previous embodiment.

Next, FIG. 5(a) shows a fourth embodiment of the present invention.

[Explained by bl.

In this embodiment, two locking portions 23 are provided on each side of the groove portion 22 in the radial direction along the side surface 39 of the shaft portion 3a, and the protrusion portion 35 is provided with two locking portions 23 on both sides of the groove portion 22 when engaged with the groove portion 22. A raised portion 35a is formed at a position corresponding to the locking portion 23, and a notch 35b is formed in the raised portion 35a so that the raised portion 35a can easily enter the locking portion 23 during plastic deformation by the punch 36. It is formed.

Next, the fifth aspect of the present invention. Regarding the example, FIG. 6(a).

Tb).

In this embodiment, a circular locking portion 23 having a diameter larger than the width of the groove 22 is provided at the tip of the groove 22, and the projection 35 is provided with a locking portion 23 when the projection 35 engages with the groove 22.
A raised portion 35a is formed at a position corresponding to 3.

Next, FIG. 7(a) shows a sixth embodiment of the present invention.

(Explained in bl.

In the present example row, the groove portion 22 has a shape that is gradually wider than the end surface 24 of the shaft portion 3a. In other words, the groove portion 22 and the locking portion 23 are integrated.

The protrusion 35 that engages with the groove 22 has the same width as the end surface 24 of the groove 22.
a has a shape that gradually rises *6 from the end 26 side of the movable core 20.

In each of the embodiments described above, the length of the hollow shaft 25 is approximately the same as the length of the core hole 21, but the length of the hollow shaft 25 is not limited to the above, and the length of the hollow shaft 25 is not limited to the above. The length may be as long as it is necessary to coaxially fix 20. However, the length does not exceed the length of the core hole 21.

Further, in each of the above embodiments, there are two grooves 22 and two protrusions 35, but two or more grooves 22 and two or more protrusions 35 may be provided.

〔Effect of the invention〕

As described above, according to the present invention, the hollow shaft protrudes from the end face of the needle valve and has a space through which fluid can flow;
A needle valve is provided with grooves provided from the end face of the needle valve at multiple locations on the side surface of the needle valve, and locking portions provided in the grooves. connected to a movable core having a protrusion that engages with the protrusion and has a portion with a thickness slightly larger than the groove depth of the groove, and the interlocking portion between the groove and the protrusion is plastically deformed;
Since a part of the protrusion is connected to the stopper, the length of the hollow shaft of the needle valve is made sufficiently longer than the diameter of the core hole, so that the needle valve and the movable core can be connected with high precision. In addition, since the core member of the protrusion is inserted into the locking portion, relative axial movement between the needle valve and the movable core is effectively prevented, and repeated It is possible to suppress the loosening of the joint due to operation. Furthermore, according to the coupling method according to the present invention, there is no change in the cross-sectional area of the moving core through which the lines of magnetic force pass, as shown by the arrow (A) in FIG. This has the excellent effect of preventing deterioration of the magnetic properties of the core member.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an electromagnetic fuel injection valve having the configuration of the first embodiment of the present invention, and FIG. 2 Figure 1bl is i82
Fig. 2 1bl is a perspective view showing the structure of the main parts of the first embodiment of the present invention before they are combined, and Fig. 3 ta) is a sectional view of - in Fig. +a). FIG. 3(b) is a front view showing the configuration of the connecting portion on the needle valve side of the movable core (1111) of the second embodiment of the present invention, and FIG. A front view showing the structure of the needle valve side coupling part in the third embodiment of the present invention, FIG.
FIG. 5(a) is a front view showing the structure of the needle valve side coupling portion of the fourth embodiment of the present invention, and FIG. 5(b) is a front view showing the structure of the movable core side coupling portion of the fourth embodiment of the present invention. 6th front view showing
Figures [al] is a front view showing the configuration of the needle valve side coupling part of the fifth embodiment of the present invention, and Figure 6l-) is a front view showing the configuration of the movable core side coupling part of the fifth embodiment of the present invention. , Figure 7 (a
) is a front view showing the structure of the needle valve side coupling part of the sixth embodiment of the present invention, and 71st mountain) is a front view showing the structure of the movable core side coupling part of the sixth embodiment of the present invention. . 3... Needle valve, 20... Movable core, 21...
Core hole, 22...Groove portion, 23...Locking portion, 24...
- Needle valve end surface, 25...Hollow shaft, 35...Protrusion, 35a...Protuberant portion, 39...Needle valve side surface. Representative Patent Attorney Takashi Okabe 1st District Figure 3 (a) Figure 4 (a) Figure 5 (a) (b) (b) Figure 6 (6) (a) (b) (1))

Claims (1)

[Scope of Claims] A hollow shaft protruding from the end face of the needle valve at +1 and having a space through which fluid can flow, grooves provided at multiple locations on the side surface of the needle valve from the □ face of the needle valve end, and the A needle valve equipped with a locking part provided in a groove, a core hole that engages with the hollow shaft, and a protrusion that engages with the groove and has a portion with a thickness slightly larger than the groove depth of the groove. an electromagnetic type having a configuration in which a movable core is connected to the movable core, and an interlocking portion between the part and the protrusion □ is plastically deformed, and a part of the protrusion is coupled to the locking part. Formula % (2) Claim 1, wherein the locking part is a plurality of groove-shaped parts formed along the side surface of the needle valve in a radial direction with respect to the direction in which the groove part 1 is formed. Electromagnetic fuel injection valve. (3) The electromagnetic fuel injection valve according to claim 2, wherein the locking portion is formed in a direction perpendicular to the direction in which the groove □ portion is formed.