JPH0777127A - Electromagnetic fuel injection valve and method of adjusting fuel injection amount in electromagnetic fuel injection valve - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide an electromagnetic fuel injection valve capable of extremely easily setting the maximum stroke and minute flow rate of an on-off valve with extremely high accuracy. [Structure] The valve seat body 8 is provided in the opening / closing valve guide hole 2B on one end A side of the housing, and the adjustment pipe insertion hole 3F of the fixed core 3B of the other magnetic pole portion 3 arranged on the other end B side is provided. Adjustment tube 6
However, they are inserted and arranged with a relatively light press-fitting load so as to be movable in the longitudinal axis direction during the adjusting process, respectively, and are caulked and fixed after the adjusting process. The open / close valve 4 pressed by the spring S is movably arranged in the open / close valve guide hole 2B. In the on-off valve full opening adjustment process, the valve seat body 8 is moved to the on-off valve guide hole 2
By moving in B to adjust the gap X between the rear end 4F of the on-off valve 4 and the front end 3E of the fixed core 3B,
The spring force adjusting step is performed by moving the adjusting pipe 6 in the longitudinal axis direction. The adjustment of the fuel injection amount is performed by performing the opening / closing valve fully open adjusting step after the electromagnetic fuel injection valve assembling step, and then performing the spring force adjusting step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic fuel injection valve used in an electronically controlled fuel injection device for an internal combustion engine, and a method for adjusting a fuel injection amount during a manufacturing process of the electromagnetic fuel injection valve.

[0002]

2. Description of the Related Art A structure (referred to as a first conventional example) shown in FIG. 1 which is regarded as a prior art in Japanese Utility Model Laid-Open No. 58-137864 has a spacer between a valve housing and a magnetic housing. A gap is formed between the spacer and the flange of the on-off valve, while a gap is formed between the armature and the fixed magnetic core. The maximum stroke of the on-off valve is determined by the gap where the flange of the on-off valve contacts the spacer.

In the device disclosed in Japanese Utility Model Laid-Open No. 58-137864 (referred to as a second conventional example), a non-magnetic spacer is fixed to the rear end surface of the armature, and it is provided between the coupling surface between the valve housing and the magnetic housing. The front end face of the fixed magnetic core is located on the same plane as or behind the coupling face of the magnetic housing with a ferromagnetic spacer of a certain thickness interposed, and the rear end face of the armature and the coupling face of the valve housing are adjusted to adjust the opening / closing valve. Techniques for adjusting stroke are disclosed. The maximum stroke of the on-off valve is determined by the thickness of the ferromagnetic spacer and the difference between the rear end surface of the valve housing and the rear end surface of the non-magnetic spacer of the armature.

[0004]

The first conventional example has the following problems. When setting the maximum stroke of the on-off valve, press the on-off valve against the valve seat and measure the difference between the rear end face of the valve housing and the rear end face of the valve flange. Add processing to the rear end face. Since the stroke is restricted by bringing the flange into contact with the spacer during such measurement, the rear end surface of the valve flange is always positioned inside the rear end surface of the valve housing, which makes it difficult to perform the measurement accurately. However, it is difficult to improve the processing accuracy of the rear end surface of the valve housing and the rear end surface of the valve flange based on this, and thus it is difficult to maintain the accuracy of the maximum stroke. When air or a gap is provided between the rear end surface of the armature and the front end surface of the fixed iron core, measure the combined dimensions of the magnetic housing and fixed iron core, the combined dimensions of the valve housing and on-off valve flange, and the armature, and then use the spacer. Select the spacer by deciding the thickness of the spacer. In such measurement, the magnetic housing and the fixed iron core are measured in the axial direction inside the hole, which makes precise measurement difficult, and the valve housing and the on-off valve including the armature are not fixed. Moreover, since it projects more than the valve housing, it is difficult to perform precise measurement due to the influence of tilting. Therefore, it is difficult to accurately determine the thickness of the spacer. Although the thickness of the spacer is determined based on the above measurement, it is necessary to prepare spacers of the same type and different thickness every 1 μm, which increases the number of parts and complicates the selection work and management work. It is not preferable because it hinders the efficiency and increases the manufacturing cost.

The second conventional example has the following problems. Even if the thickness of the ferromagnetic spacer is constant, it is necessary to process this dimension to maintain micron accuracy. Therefore, even if it is easy to measure this thickness, Maintenance must be managed to the same level as conventional spacers, and it is necessary to prepare spacers of the same type but with different thickness, which increases the number of parts and complicates selection work and management work, hindering production efficiency. This is not preferable because it causes high manufacturing cost. It is difficult to maintain a constant difference between the rear end surface of the valve housing and the rear end surface of the non-magnetic spacer of the armature.
This difference is determined by the valve housing, the armature including the non-magnetic spacer, and the on-off valve.
Since the on-off valve including the valve housing, the non-magnetic spacer, and the armature is not fixed and protrudes more than the valve housing, it is difficult to perform precise measurement due to the influence of tilting. Therefore, it is difficult to accurately determine the thickness of the spacer. It should be noted that the effect that the coupling surface of the magnetic housing and the front end surface of the fixed iron core are simultaneously machined on the same plane does not reach the above difference.

The present invention has been made in view of the above problems, and closes the maximum stroke of the on-off valve that contributes to the fully opened flow rate of the electromagnetic fuel injection valve and the on-off valve that contributes to the minute flow rate and the flow rate inclination characteristic in idling operation and the like. Providing an electromagnetic fuel injection valve with excellent fuel injection characteristics that can set the spring force of the spring urging in the direction with extremely high accuracy, and adjust the maximum stroke of the on-off valve and the spring force of the spring with high accuracy and extremely easily. It is to provide a method for adjusting the fuel injection amount that can be performed.

[0007]

In order to achieve the above-mentioned object, in the electromagnetic fuel injection valve of the present invention, the opening / closing valve is movably guided and supported at one end by being connected to the fuel injection hole through the valve seat. A valve seat forming portion having an opening / closing valve guide hole is formed. At the other end, a flat plate-shaped magnetic pole piece, a fixed core extending from the magnetic pole piece toward one end, and a fuel flowing from the magnetic pole piece toward the other end. A cylindrical housing having a magnetic pole portion on the other side having a flow path boss and an adjusting tube insertion hole penetrating from a rear end portion of the fuel flow path boss toward a front end portion of the fixed core, and a magnetic pole piece portion of the housing. And a valve seat forming part, and is disposed in the housing, and a fixed core insertion hole is formed through the axial part along the longitudinal axis of the shaft part, and a coil is wound around the outer circumference of the shaft part. The device and the valve seat are movably arranged in the opening / closing valve guide hole of the valve seat forming portion, and An on-off valve that has a valve body that can be closed and is elastically biased by a spring so that the valve seat closes the valve seat, and is inserted into the adjustment tube insertion hole of the other side magnetic pole part, and its longitudinal axis direction. An electromagnetic fuel injection valve having a fuel passage through which a fuel passage is formed and a front end portion of which is adjusted to a rear end of a spring, the electromagnetic fuel injection valve including a valve seat and a fuel injection hole connected to the valve seat. The valve seat is formed by a member separate from the valve seat forming part, and the valve seat is opened and closed by inserting the valve seat from the front end of the valve seat forming part toward the opening / closing valve guide hole. The valve seat is arranged to face the valve body, the rear end of the on-off valve is arranged to face the front end of the fixed core with an adjusted gap, and the valve seat in the same state is fixed to the valve seat forming part. Is.

As a fuel injection amount adjusting method, a valve seat forming body including a valve seat body in which a valve seat is inserted and arranged so as to face a valve body of an on-off valve, and an adjusting pipe is inserted into an adjusting pipe inserting hole. A step of assembling an electromagnetic fuel injection valve for assembling an opening / closing valve in which a valve element is elastically biased toward a valve seat by a spring in a housing including the other side magnetic pole part, and a valve seat forming part Adjusting the gap between the front end of the fixed core and the rear end of the on-off valve by moving the valve seat body inserted into the on-off valve guide hole from the front end of the valve seat in the longitudinal axis direction of the on-off valve guide hole. After adjusting the maximum stroke of the on-off valve, the valve seat body is fixed to the valve seat forming part, and the opening / closing valve full-open adjustment process, and the adjustment pipe inserted into the adjustment pipe insertion hole of the other side magnetic pole part The spout that is contracted between the front end of the adjusting pipe and the on-off valve by moving in the direction Adjusting the spring force of the spring to adjust the closing direction biasing force of the spring S with respect to the on-off valve, and then fixing the adjusting pipe to the other magnetic pole part. After the assembling step of the electromagnetic fuel injection valve, The on-off valve fully open adjustment process is performed, and then the spring force adjustment process is performed.

[0009]

In order to adjust the gap between the front end of the fixed core and the rear end of the on-off valve, the valve seat body disposed in the on-off valve guide hole of the valve seat forming portion is fitted with the longitudinal axis of the on-off valve guide hole. The valve seat body is fixed to the valve seat forming portion in a state in which the valve seat body is adjusted by adjusting the maximum stroke of the on-off valve. On the other hand, to adjust the spring force of the spring in the closing direction with respect to the on-off valve, the spring force of the spring that urges the on-off valve in the closing direction by adjusting the insertion position of the adjustment tube inserted in the adjustment tube insertion hole. Was adjusted, and in this adjusted state, the adjusting tube was fixed to the magnetic pole on the other side, and the spring force of the spring in the closing direction of the on-off valve was adjusted accordingly.

After the maximum stroke of the on-off valve is adjusted, an on-off valve full-open adjusting step for fixing the valve seat body to the valve seat forming portion is performed, and then the urging force of the spring with respect to the on-off valve in the closing direction is adjusted. By performing the spring force adjusting step of fixing the spring to the other side magnetic pole portion, particularly, the closing direction biasing force of the spring with respect to the opening / closing valve can be adjusted extremely accurately.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In the housing 1, a valve seat forming portion 2 is formed at one end A (right side in FIG. 1) and another side magnetic pole portion 3 is formed at the other end B (left side in FIG. 1). The housing 1 has a cylindrical shape, and a valve seat forming portion 2 projects rightward on one end A side. Inside the valve seat forming portion 2, from a bottom portion 1A of the housing 1 to a front end portion 2A of the valve seat forming portion 2. An on-off valve guide hole 2B that reaches up to is opened. The other end B of the housing 1
A locking step portion 1B is formed near the opening on the (left side in the drawing) side, and a thin portion 1C is formed further toward the other end B side than the locking step portion 1B. The other side magnetic pole portion 3 is a magnetic pole piece portion 3A.
, The fixed core 3B, and the fuel flow path boss 3C. The magnetic pole piece portion 3A is composed of a flat plate-shaped collar portion arranged on the locking step portion 1B of the housing 1, and the fixed core 3B protrudes from the magnetic pole piece portion 3A toward one end A (right side in the drawing). The other end B from the pole piece 3A (left in the figure)
The fuel flow path boss 3C projects toward the side. The fuel flow path boss 3C, the magnetic pole piece portion 3A, and the fixed core 3B are formed coaxially, and the fuel flow path boss 3C extends from the rear end portion 3D to the magnetic pole piece portion 3.
An adjustment tube insertion hole 3F is formed through the hole A toward the front end portion 3E of the fixed core 3B in the central longitudinal axis direction.

Reference numeral 8 denotes a valve seat body having a valve seat 8A and a fuel injection hole 8B. The fuel injection hole 8B is formed by penetrating from the front end portion 8C of the valve seat body 8 toward the rear end portion 8D. A valve seat 8A is formed at the opening to the rear end portion 8D of the fuel injection hole. The valve seat body 8 has a cylindrical outer shape and is inserted and arranged in the on-off valve guide hole 2B with a relatively light press-fitting load.

Next, the assembly of the electromagnetic fuel injection valve will be described. First, the valve seat body 8 is inserted and arranged in the opening / closing valve guide hole 2B of the housing 1. At this time, the valve seat 8A of the valve seat body 8 is on the bottom portion 1A side of the housing 1 (left side in the drawing).
Head to. The insertion depth of the valve seat body 8 in the open / close valve guide hole 2B may be appropriate, but the shallower one (the shallower means that the rear end portion 8D of the valve seat body 8 does not approach the bottom portion 1A of the housing 1) is rearward. Adjustment becomes easy. On the other hand, the other side magnetic pole part 3
The adjustment tube 6 is inserted and arranged in the adjustment tube insertion hole 3F. At this time, the front end portion 6B of the adjustment tube 6 is arranged near the front end portion 3E of the fixed core 3B.

An opening / closing valve 4 is movably arranged in the opening / closing valve guide hole 2B. The opening / closing valve 4 has a valve body 4A for opening and closing a valve seat, which will be described later, at one end A (on the right side in the drawing) of the opening / closing valve and a flow around the outer circumference thereof. A passage groove 4B is bored, and a passage 4C is formed by the on-off valve guide hole 2B and the passage groove 4B. Further, a slit groove 4D is bored in the rear end portion 4F of the other end B side (left side in the figure) of the on-off valve 4 so as to traverse the on-off valve 4 in the diametrical direction. 4B, and a spring holding hole 4E is further formed in the opening / closing valve 4.

Reference numeral 5 denotes an electromagnetic device, which is formed with laterally extending flanges 5B at both ends of a shaft portion 5A extending in the longitudinal axis direction, and a coil 5C is wound around the outer periphery of the shaft portion 5A. At the center of the axial portion 5A in the longitudinal axis direction, one collar portion 5B is provided.
A fixed core insertion hole 5D from one flange portion 5B to the other flange portion 5B is penetrated therethrough. Reference numeral 6 is an adjusting pipe which is formed in a circular tube shape and penetrates through the fuel passage 6A in the longitudinal axis direction, and is inserted into the adjusting pipe inserting hole 3F of the other side magnetic pole portion 3 with a relatively light press-fitting load. Will be placed. Note that 5E is a terminal whose one end is connected to the coil 5C and whose other end protrudes from the collar portion 5B. Further, the strainer 7 can be inserted and arranged at the other end B side (left side in the figure) of the adjustment tube insertion hole 3F by enlarging its diameter. Then, the electromagnetic device 5 is arranged in the housing 1 through the opening of the housing 1 on the locking step 1B side. According to this, the flange portion 5B at one end (right side) of the electromagnetic device 5 is the bottom portion 1A of the housing 1.
And the other end (left side) of the collar portion 5B is arranged at substantially the same position as the locking step portion 1B.

Next, the on-off valve 4 is arranged in the on-off valve guide hole 2B through the fixed core insertion hole 5D of the electromagnetic device 5. According to this, the valve body 4A of the on-off valve 4 is arranged in the valve seat body 8. The on-off valve 4 is arranged so as to face the valve seat 8A, and the on-off valve 4 is movably arranged in the on-off valve guide hole 2B.
The rear end portion 4F is directed to the other side B (left side in the drawing), and the fixed core insertion hole 5D is selected to have a hole diameter into which the on-off valve 4 can be inserted. The spring S is inserted and arranged toward the on-off valve 4 in such a state through the fixed core insertion hole 5D of the electromagnetic device 5. According to this, the spring S is arranged in the spring holding hole 4E of the on-off valve 4, and the front end S1 of the spring S is
Is locked to the on-off valve 4, and the rear end S2 of the spring S projects from the rear end 4F of the on-off valve 4 to the other end B side (to the left in the figure) and is still in a free state.

Next, the other magnetic pole portion 3 is arranged on the locking step portion 1B of the housing 1. According to this, the fixed core 3 is arranged in the fixed core insertion hole 5D of the electromagnetic device 5, The magnetic pole piece 3A is arranged on the locking step 1B, and the fuel flow path boss 3C projects to the other end B side (left side in the drawing).
In this state, the thin wall portion 1C of the housing 1 is inwardly rolled and caulked toward the magnetic pole piece portion 3A.
As a result, the other magnetic pole portion 3 is fixed to the housing 1. According to the above, the rear end 4F of the on-off valve 4 is fixed to the fixed core 3
Are arranged to face the front end portion 3E of the
The rear end S2 of the spring S is locked to the front end 6B of the adjusting pipe 6, and the valve body 4A of the on-off valve 4 is elastically biased to the valve seat 8A. In such a state, the maximum stroke of the on-off valve 4 and the spring force of the spring S in the closing direction on the on-off valve 4 have not been adjusted yet. This completes the electromagnetic fuel injection valve assembly process.

Next, a method of adjusting the fuel injection amount will be described. First, the adjustment of the maximum stroke X (corresponding to the gap X) of the on-off valve 4 that determines the fully opened flow rate of the electromagnetic fuel injection valve will be described. For adjustment, the coil 5 of the electromagnetic device 5
The on-off valve 4 supplies a full-stroke current to C,
According to this, the on-off valve 4 has the rear end portion 4F of the on-off valve 4 fixed by the magnetic force generated by the energization of the coil 5C.
It moves until it abuts on the front end portion 3E of B, and the valve body 4A moves to the valve seat 8
Open A. Thus, the fuel supplied from the fuel passage 6A of the adjusting pipe 6 is provided with the slit groove 4D of the on-off valve 4 and the flow passage groove 4B.
A flow passage 4C formed by the opening and closing valve guide hole 2A flows into the valve seat 8A and is injected from the fuel injection hole 8B. At this time, the amount of fuel injected from the fuel injection hole 8B is measured and compared with the target full-open fuel value to adjust the gap X so that a desired full-open flow rate can be obtained. Specifically, this adjustment is to move the valve seat body 8 forward and backward in the opening / closing valve guide hole 2B in the longitudinal axis direction of the opening / closing valve guide hole 2B. When the valve seat body 8 is moved leftward in the drawing, The gap between the front end portion 3E of the fixed core 3B and the rear end portion 4F of the on-off valve 4 can be made small and the flow rate can be adjusted in the decreasing direction, while the valve seat body 8 is moved to the right in the figure. Is moved, the gap can be increased and the flow rate can be adjusted in an increasing direction, and the full open fuel amount actually injected from the electromagnetic fuel injection valve and the target full open fuel value can be compared and determined. By
It is possible to adjust the position of the valve seat body 8 so that the fully opened fuel amount to be injected can completely match the target fuel value. That is, the gap X can be continuously and extremely finely controlled by the valve seat body 8. The fact that the valve seat body 8 can be freely moved back and forth as described above is because the valve seat body 8 is inserted into the on-off valve guide hole 2B with a light load. Then, in the state where the maximum stroke X of the on-off valve 4 is properly adjusted by the position adjustment of the valve seat body 8 in this manner, the valve seat body 8
Is fixed to the housing 1. In this example, the thin portion provided in the vicinity of the front end portion 2A of the valve seat forming portion 2 is point crimped toward the outer periphery of the valve seat body 8. For example, another fixing means such as an adhesive is used. You may use. With the above, the on-off valve full-open adjustment process was completed and an accurate full-open flow rate was obtained.

Next, the setting of the spring force in the closing direction of the opening / closing valve 4 of the spring S, which determines a minute flow rate such as the idling flow rate of the electromagnetic fuel injection valve, will be described. In the adjustment, a current defined in the coil 5C is supplied for a short time so as to obtain a minute flow rate, whereby the electromagnetic fuel injection valve injects a minute fuel. At this time, the amount of the minute fuel injected from the fuel injection hole 8B is measured, compared with the target minute fuel value, and the spring S for urging the opening / closing valve 4 in the closing direction is obtained so as to obtain a desired minute flow rate. Adjust the spring force. Specifically, this adjustment is to advance and retreat by locking a jig (not shown) at the rear end portion 6C of the adjustment tube 6, and when the adjustment tube 6 is advanced to the right in the figure, the adjustment tube The spring force of the spring S with respect to the on-off valve 4 by the front end portion 6B of 6 can be strengthened, the minute flow rate can be adjusted in the decreasing direction, and the rising characteristic of the on-off valve 4 can be delayed, while the left side in the figure When the adjusting pipe 6 is withdrawn, the spring force of the spring S exerted on the on-off valve 4 by the front end portion 6B of the adjusting pipe 6 can be weakened, the minute flow rate can be adjusted in the increasing direction, and the rising characteristic of the on-off valve 4 can be increased. It is possible to accelerate the fuel injection amount, and by comparing and discriminating the minute fuel amount actually injected from the electromagnetic fuel injection valve and the target minute fuel value, it is possible to completely match the injected fuel amount with the target fuel value. Kill. That is, the spring force of the spring S for urging the opening / closing valve 4 in the closing direction can be continuously and extremely controlled by the adjusting pipe 6. Then, in the state in which the closing direction biasing force of the spring S on the on-off valve 4 is properly adjusted by the position adjustment of the adjustment pipe 6 in this way,
The adjusting tube 6 is fixed to the housing 1. In this example, the outer periphery of the fuel flow path boss 3C projecting from the magnetic pole piece portion 3A toward the other end B is point crimped toward the outer periphery of the adjusting tube 6, but another fixing means is used. Good. With the above, the spring force adjusting process was completed and an accurate minute flow rate was obtained.

By performing the spring force adjusting step after the on-off valve full opening adjusting step, it is possible to accurately control the full open flow rate and the minute flow rate. That is, the valve seat body 8 is fixed to the housing 1 at the time when the fully open flow rate adjustment is completed, and even if the adjustment pipe 6 is moved back and forth for the fine flow rate adjustment, the valve seat body 8 is already moved relative to the housing 1. Since the valve seat body 8 does not move at all by the movement of the adjusting pipe 6, the valve seat body 8 can accurately maintain the adjusted position,
On the other hand, the adjusting tube 6 can also be adjusted in the correct position. If the position of the adjustment pipe 6 is adjusted first to fix the adjustment pipe 6 to the housing 1 and then the position of the valve seat body 8 is adjusted, the position of the valve seat body 8 is changed and the spring force is changed. It cannot be changed and accurate minute flow rate control cannot be performed.

As described above, the out-molding step is performed after the assembling step, the on-off valve full-open adjusting step and the spring force adjusting step are completed. This is because the outer circumference of the housing 1 including the magnetic pole piece portion 3A on the other end B side and the outer circumference of a part of the fuel flow path boss 3C protruding from the magnetic pole piece portion 3A of the housing 1 to the other end B side are made of a synthetic resin material. At this time, the base of the terminal 5E is also molded at the same time.
The valve body and the flow path structure of the on-off valve 4 are not limited to the example shown in the figure, and may be changed as appropriate. Further, the order of assembling the respective components in the assembling step is not particularly limited to the above example.

[0022]

As described above, according to the electromagnetic fuel injection valve of the present invention, the following special effects are obtained. The maximum stroke of the on-off valve is determined by moving the valve seat body in the direction of the longitudinal axis in the on-off valve guide hole to adjust the gap between the rear end of the on-off valve and the front end of the fixed core. The control of the minute flow rate by the on-off valve is performed by adjusting the spring force by adjusting the position of the front end portion of the adjusting tube locked to the rear end of the spring that biases the on-off valve in the closing direction. Thus, the conventionally used spacer is no longer needed. According to this, the measurement work of each part dimension for determining the thickness of the spacer, the thickness of the spacer is prepared every several μm, the work of selecting the spacer based on the measurement and the work of assembling the spacer, and more than one are prepared. It was possible to abolish the work of managing the spacers that are used, which greatly improved the production efficiency. The fully open flow rate determined by the maximum stroke of the on-off valve and the minute flow rate determined by the biasing force of the spring in the closing direction with respect to the on-off valve completely adjust to the target flow rate value by linearly adjusting the valve seat body and adjustment pipe. Since they can be matched with each other, it is possible to very easily provide an electromagnetic fuel injection valve having high flow rate uniformity. As mentioned above, the flow rate is controlled by linearly moving and adjusting the valve seat body and the adjusting pipe, so it is necessary to manufacture the dimensional accuracy of each part with extremely high accuracy and to measure the dimensional accuracy with high accuracy. It is possible to greatly reduce the cost of manufacturing each part.
The fully open flow rate and the minute flow rate can be variably adjusted within a relatively large range by moving the valve seat body and adjustment pipe.
A highly versatile electromagnetic fuel injection valve can be provided that can easily cope with various required flow rates without changing parts. Since the spring force adjusting step is performed after the opening / closing valve full-opening adjusting step, the closing direction biasing force of the spring with respect to the opening / closing valve can be adjusted accurately, and the minute flow rate can be accurately controlled.

[Brief description of drawings]

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

[Explanation of symbols]

 A One end B The other end S Spring X Gap between the front end of the fixed core and the rear end of the on-off valve 1 Housing 2 Valve seat forming part 2B On-off valve guide hole 3 Other side magnetic pole part 3A Magnetic pole piece part 3B Fixed core 3C Fuel flow Road boss 3D Rear end 3E Front end 3F Adjustment pipe insertion hole 4 Open / close valve 4A Valve body 5 Electromagnetic device 5A Shaft portion 5C Coil 5D Fixed core insertion hole 6 Adjustment pipe 6A Fuel passage 6B Front end portion 8 Valve seat body 8A Valve seat 8B Fuel injection hole

Claims (2)

[Claims] 1. A valve seat forming portion 2 having an opening / closing valve guide hole 2B at one end A, which is connected to a fuel injection hole 8B through a valve seat 8A and movably guides and supports the opening / closing valve 4. Edge B
A flat pole piece 3A and one end A from the pole piece 3A
The fixed core 3B directed toward the side, the fuel flow path boss 3C directed toward the other end B side from the magnetic pole piece 3A, and the adjustment penetrating from the rear end 3D of the fuel flow path boss 3C toward the front end 3E of the fixed core 3B. A cylindrical housing 1 provided with the other side magnetic pole portion 3 having a tube insertion hole 3F, and a magnetic pole piece portion 3 of the housing 1.
Disposed in the housing 1 between A and the valve seat forming portion 2,
A fixed core insertion hole 5D is formed by penetrating along the longitudinal axis of the shaft portion 5A, and the coil 5 is formed on the outer periphery of the shaft portion 5A.
The electromagnetic device 5 around which C is wound, and at least the valve seat forming portion 2
Is movably arranged in the on-off valve guide hole 2B of the valve seat 8A.
Equipped with a valve body 4A capable of opening and closing
A is elastically biased so as to close the valve seat 8A, and is inserted into the adjustment tube insertion hole 3F of the other side magnetic pole portion 3,
In an electromagnetic fuel injection valve having a fuel passage 6A penetrating therethrough in the direction of the longitudinal axis thereof and an adjusting pipe 6 having a front end portion 6B thereof locked to a rear end S2 of a spring S,
A valve seat body 8 including a valve seat 8A and a fuel injection hole 8B connected to the valve seat 8A is formed as a separate member from the valve seat forming portion 2, and the valve seat body is formed on the front end portion 2A of the valve seat forming portion 2. The valve seat 8A of the valve seat body 8 is disposed so as to face the valve body 4A of the open / close valve 4 by being inserted and arranged toward the open / close valve guide hole 2B.
An electromagnetic fuel injection valve in which a rear end portion 4F is arranged opposite to a front end portion 3E of a fixed core 3B with an adjusted gap X, and a valve seat body 8 in the same state is fixedly arranged in a valve seat forming portion 2. 2. A valve seat forming portion 2 including a valve seat body 8 in which a valve seat 8A is inserted and arranged so as to face the valve body 4A of an on-off valve 4, and an adjusting pipe 6 is inserted in an adjusting pipe insertion hole 3F. On the housing 1 including the other side magnetic pole portion 3, the opening / closing valve 4 in which the valve body 4A is elastically biased toward the valve seat 8A by the spring S, and the electromagnetic device 5 are provided.
And the valve seat body 8 inserted into the opening / closing valve guide hole 2B from the front end portion 2A of the valve seat forming portion 2 and the longitudinal axis of the opening / closing valve guide hole 2B. Moving in the direction, the gap X between the front end 3E of the fixed core 3B and the rear end 4F of the on-off valve 4 is adjusted to adjust the maximum stroke X of the on-off valve 4, and then the valve seat body 8 is moved to the valve seat forming portion. Two
The opening / closing valve fully opened adjusting step and the adjusting tube 6 inserted and arranged in the adjusting tube insertion hole 3F of the other side magnetic pole portion 3 are moved in the longitudinal axis direction, and the front end portion 6B of the adjusting tube 6 and the opening / closing valve. A spring force adjusting step of fixing the adjusting tube 6 to the other side magnetic pole portion 3 after adjusting the spring force of the spring S compressed between the adjusting valve 6 and the opening / closing valve 4 to adjust the closing direction biasing force of the spring S to the on-off valve 4. 2. The method for adjusting the fuel injection amount in a fuel injection valve according to claim 1, further comprising a step of adjusting the opening / closing valve fully opening and a step of adjusting the spring force after the step of assembling the electromagnetic fuel injection valve.