JP2018112121A - Method of manufacturing fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a fuel injection valve capable of acquiring an accurate injection quantity during an operation by causing a valve closing time CT to match a reference value, assuming the operation (wet state) during manufacturing, and reducing loss in a manufacturing process.SOLUTION: A method of manufacturing a fuel injection valve includes a step for filling a high-pressure flow channel of a fuel injection valve with fuel, a step for setting an energization time from the start of energization to a magnet of a solenoid valve to the stop of the energization, a step for starting the energization to the magnet, a step for stopping the energization to the magnet, a step for measuring a valve closing time from the stop of the energization to the magnet to the generation of a peak value of counter electromotive force in the magnet, and a step for adjusting a lift amount of an armature so that the valve closing time corresponding to the energization time matches a reference value.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method for manufacturing a fuel injector (injector), and more particularly to a method for manufacturing a fuel injector that equalizes an initial injection amount of the fuel injector within a reference value.

  2. Description of the Related Art Conventionally, in a method for manufacturing a common rail fuel injection control device for an internal combustion engine, an adjustment technique is known that eliminates variations in characteristics of fuel injection valves and makes the initial injection amount uniform within a reference value. The fuel injection amount of the fuel injection valve is the energization time ET to the magnet of the solenoid valve, the valve closing time CT which is the time from when the energization time ET ends until the armature of the fuel injection valve is seated on the valve seat, Determined by Here, the energization time ET is controlled by the electronic control unit. Further, the valve closing time CT varies depending on the lift amount of the armature. The valve closing time CT can be calculated by detecting the seating timing based on the back electromotive force generated in the magnet when the armature is seated on the valve seat, and measuring the time from when the energization time ET ends ( (See Patent Document 1).

  In the conventional method for manufacturing a fuel injection valve, the lift amount of the armature is adjusted at the manufacturing stage in order to make the valve closing time CT, which is the time from when the energization time ET ends until the armature sits on the valve seat constant. ing. This adjustment is usually performed by measuring the valve closing time CT in a so-called dry state in which fuel is not filled into the fuel injection valve.

  FIG. 8 is a flowchart for adjusting the lift amount of the conventional armature. First, in step 1, assembly of the fuel injection valve is started. When the temporary assembly of the fuel injection valve is completed in step 2, the process proceeds to step 3. In step 3, the valve closing time CT is measured in the dry state, and the lift amount of the armature is adjusted. In step 4, the assembly of the fuel injection valve is completed. Proceeding to step 5, the fuel injection valve is attached to the injection amount measuring device. In step 6, the fuel injection valve is warmed up and filled with high-pressure fuel. Proceeding to step 7, the fuel injection amount is measured. When the injection amount is within the reference value, the process proceeds to step 8 and the assembly of the fuel injection valve is finished. When the injection amount is outside the reference value in step 7, the process proceeds to step 9 to completely disassemble the fuel injection valve. Next, it progresses to step 10 and wash | cleans each component of a fuel injection valve. Then, returning to step 2, the fuel injection valve is temporarily assembled again.

JP2015-59427A

Conventionally, as shown in FIG. 8, the lift amount of the armature is adjusted in a state where fuel is not filled into the fuel injection valve (dry state). However, since the lift amount of the armature is different between a state where the fuel injection valve is not filled (dry state) and an operation where the fuel is filled into the fuel injection valve (wet state), the valve closing time CT is different. It will be different. This is because the valve body expands due to the pressure of the fuel supplied to the inside of the valve body (rail pressure P) when the dry state changes to the wet state, and the distance between the magnet and the valve seat changes, so the lift amount of the armature Was one of the causes. In addition, the change in the valve closing time CT was caused by a change in the lubrication of the sliding portion by the fuel between the wet state and the dry state, and a change in the armature movement speed due to damping. .
When the valve closing time CT is different between the dry state and the wet state, there is a problem that the fuel injection amount is different between the adjustment point in manufacturing the fuel injection valve and the actual operation point. Further, when the injection amount is measured and becomes defective, it is not possible to know where the fuel injection valve has a defect including the lift amount of the armature, so the fuel injection valve has to be completely disassembled and readjusted.

  The present invention has been made in order to solve the above-described problems. By assuming that the valve closing time CT is adjusted to a reference value at the time of operation (wet state) at the time of manufacture, an accurate injection amount at the time of operation is achieved. It is another object of the present invention to obtain a method for manufacturing a fuel injection valve that reduces manufacturing process losses.

  The method of manufacturing a fuel injection valve according to the present invention sets the step of filling the high pressure flow path of the fuel injection valve with fuel and the energization time from the start of energization to the magnet of the solenoid valve until the energization is stopped. Steps, starting energization of the magnet, stopping energization of the magnet, and measuring the valve closing time from when the energization to the magnet stops until the peak value of the back electromotive force occurs in the magnet And a step of adjusting the lift amount of the armature so that the valve closing time corresponding to the energization time becomes a reference value.

  According to the method for manufacturing a fuel injection valve according to the present invention, the fuel injection amount is adjusted in the wet state assuming the operation (wet state). The fuel injection amount is not different, and an accurate injection amount can be obtained during operation.

It is a lineblock diagram showing the common rail type fuel injection control device concerning an embodiment. It is sectional drawing of the fuel injection valve which concerns on embodiment. It is the figure which showed the relationship between the electric current value of the magnet of the solenoid valve which concerns on embodiment, and the lift amount of an armature. It is the schematic diagram which showed the relationship between the electricity supply time ET of the fuel injection valve which concerns on embodiment, and valve closing time CT. It is a perspective view of the fuel injection valve concerning an embodiment. It is sectional drawing which shows the lift amount of the armature which concerns on embodiment. It is an adjustment flow figure of the lift amount of the armature concerning an embodiment. It is a flow chart for adjusting the lift amount of a conventional armature.

Hereinafter, the manufacturing method of the fuel injection valve concerning the present invention is explained using a drawing. The members and arrangements described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.
Moreover, in each figure, illustration of a detailed part is simplified or abbreviate | omitted suitably. In addition, overlapping descriptions are appropriately simplified or omitted.

Embodiment.
<Basic configuration of common rail fuel injection control device>
A method for manufacturing a fuel injection valve (injector) in an embodiment of the present invention is applied to a so-called common rail fuel injection control device.
FIG. 1 is a configuration diagram illustrating a common rail fuel injection control apparatus according to an embodiment.
The common rail fuel injection control device includes a high pressure pump device 50 that pumps high pressure fuel, a common rail 1 that stores the high pressure fuel pumped by the high pressure pump device 50, and a high pressure fuel supplied from the common rail 1 to a diesel engine ( A plurality of fuel injection valves 2 to be supplied to each cylinder of the “engine 3” hereinafter, and an electronic control unit 4 (“ECU” in FIG. 1) for performing operation control of the engine 3 and fuel injection control processing described later. It is configured as a main component.
Such a configuration itself is the same as a basic configuration of a well-known fuel injection control device.

The high-pressure pump device 50 has a known configuration with the supply pump 5, the metering valve 6, and the high-pressure pump 7 as main components.
In such a configuration, the fuel in the fuel tank 9 is pumped up by the supply pump 5 and supplied to the high-pressure pump 7 through the metering valve 6. As the metering valve 6, an electromagnetic proportional control valve is used, and the energization amount thereof is controlled by the electronic control unit 4, so that the flow rate of fuel supplied to the high pressure pump 7, in other words, the discharge of the high pressure pump 7 The amount is to be adjusted.

A return valve 8 is provided between the output side of the supply pump 5 and the fuel tank 9 so that surplus fuel on the output side of the supply pump 5 can be returned to the fuel tank 9. .
The supply pump 5 may be provided separately from the high-pressure pump device 50 on the upstream side of the high-pressure pump device 50 or may be provided in the fuel tank 9.

  The fuel injection valve 2 is provided for each cylinder of the engine 3, and is supplied with high-pressure fuel from the common rail 1 and performs fuel injection by injection control by the electronic control unit 4. The so-called solenoid type is used for the fuel injection valve 2 in this embodiment.

  The electronic control unit 4 has, for example, a storage element (not shown) such as a RAM and a ROM, with a microcomputer having a known configuration as the center. Further, a circuit (not shown) for energizing and driving the fuel injection valve 2 and a circuit (not shown) for energizing and driving the metering valve 6 and the like are configured as main components. . Further, in the embodiment, a current monitor circuit 12 (indicated as “I-MONI” in FIG. 1) for detecting a counter electromotive current generated in the magnet 40 of the fuel injection valve 2 is provided. The output is supplied to a microcomputer (not shown) so as to be used for obtaining the closing timing of the solenoid valve 32 provided in the fuel injection valve 2 (details will be described later).

  The electronic control unit 4 receives a detection signal from a pressure sensor 11 that detects the pressure of fuel in the common rail 1 (rail pressure P), as well as various engine speed, accelerator opening, outside air temperature, atmospheric pressure, and the like. This detection signal is input to be used for operation control of the engine 3, fuel injection control, and the like.

<Configuration of fuel injection valve 2>
FIG. 2 is a cross-sectional view of the fuel injection valve according to the embodiment.
A known fuel injection valve 2 shown in FIG. 2 includes a fuel injection body 30, a nozzle body 31 attached to the distal end side of the fuel injection body 30, and the other end of the fuel injection body 30 that faces the nozzle body 31. And a solenoid valve 32 attached to the side. A nozzle needle 33 is disposed in the nozzle body 31 so as to be slidable in the axial direction of the nozzle body 31. A long valve piston 34 is attached to the nozzle needle 33. The valve piston 34 is slidably disposed in the fuel injection valve main body 30 in the axial direction of the fuel injection valve main body 30.

  The other end of the valve piston 34 facing the nozzle needle 33 is accommodated in the valve member 35. A control chamber 36 in which the end of the valve piston 34 is arranged is defined in the valve member 35. The control chamber 36 communicates with a high pressure connection portion 37 to which fuel is supplied from the common rail 1. The high-pressure connection portion 37 further communicates with the flow path 38 and is connected to the nozzle sheet portion 39 between the nozzle body 31 and the tip of the nozzle needle 33 via the flow path 38. The nozzle needle 33 is biased toward the nozzle sheet portion 39 by a nozzle spring 33a. In addition, the control chamber 36, the flow path 38, the nozzle sheet | seat part 39, etc. in the fuel injection valve 2 connected to the high pressure connection part 37 are called the high pressure flow path of this invention.

  The solenoid valve 32 has a magnet 40 that is a solenoid coil, and an armature 41 made of a magnetic material is disposed on the lower end side of the magnet 40. The armature 41 is disposed so as to be slidable inside the cylindrical guide portion 42. On the lower end side of the armature 41, a circular valve seat 43 on which the lower end of the armature 41 is seated is formed.

  A valve spring 45 that urges the armature 41 toward the valve seat 43 is accommodated in the upper portion of the armature 41. An orifice 44 communicating with the control chamber 36 is opened at the center of the valve seat 43. The armature 41 moves upward so as to open the orifice 44 by energizing the magnet 40. A power connection 46 is further provided above the solenoid valve 32. The fuel injection valve main body 30 and the solenoid valve 32 are joined by an adjustment nut 47.

<Operation of fuel injection valve>
In the fuel injection valve 2, energization to the magnet 40 is stopped when no fuel is injected. The armature 41 is seated on the valve seat 43 by the valve spring 45 and the orifice 44 is closed. Then, the control chamber 36 is filled with high-pressure fuel from the common rail 1 and the high-pressure fuel is similarly filled on the nozzle seat 39 side. In this state, the nozzle needle 33 moves to the nozzle sheet portion 39 side by the resultant force of the pressure receiving area of the fuel acting on the control chamber 36 and the nozzle seat portion 39 and the resultant force of the urging force acting on the nozzle spring 33a. The nozzle sheet portion 39 is closed by being biased (downward). Therefore, fuel is not injected.

  When the magnet 40 is energized from the non-energized state of the magnet 40, the fuel injection valve 2 enters the injection state. At this time, the armature 41 is attracted by the magnetic force of the magnet 40 and contacts the lower surface of the magnet 40. As the armature 41 rises, the orifice 44 is opened, and the high-pressure fuel in the control chamber 36 flows out through the orifice 44 to a fuel tank (not shown). As a result, the pressure in the control chamber 36 decreases, and the upward force due to the high-pressure fuel charged on the nozzle sheet portion 39 side overcomes the downward force applied by the control chamber 36 and the nozzle spring 33a, and the nozzle needle 33. To raise. Therefore, the fuel is injected from the tip of the nozzle body 31. And it will be in the state of the maximum injection rate by continuing electricity supply to the magnet 40. FIG.

<Valve closing time CT>
The energization time ET to the magnet 40 and the valve closing time CT during the injection of the fuel injection valve 2 will be described.
FIG. 3 is a diagram showing the relationship between the magnet current value of the solenoid valve and the armature lift amount according to the embodiment.
As shown in FIG. 3, energization to the magnet 40 of the fuel injection valve 2 according to the embodiment starts at an energization start time tp1 and stops at an energization end time tp2. At this time, the current value of the magnet 40 rapidly increases with the passage of time from the energization start time tp1, and once decreases to a certain peak value.

  Thereafter, the current becomes substantially constant until the energization end time tp2, and changes so as to decrease toward zero with the passage of time from the energization end time tp2. Then, after the energization waveform of the current value reaches zero, a convex energization waveform that peaks in a relatively short time after a lapse of some time and then becomes zero in a relatively short time appears.

At this time, the armature 41 of the solenoid valve 32 starts being lifted by being pulled by the magnet 40 at the lift start time tp3 at a slight interval from the energization start time tp1. The armature 41 sucked by the magnet 40 stops at the maximum lift position.
When the magnetic force of the magnet 40 disappears at the energization end time tp2, the armature 41 descends toward the valve seat 43. Then, the armature 41 is seated on the valve seat 43 at the seating time ta1.

  The convex energization waveform generated in the energization waveform of the current value is a display of the counter electromotive current generated in the magnet 40 when the armature 41 of the solenoid valve 32 is seated on the valve seat 43 and closed. The peak is known to correspond to the timing at which the armature 41 is seated on the valve seat 43, and in the example of FIG. 2 is the time of the seating time ta1. That is, the timing at which the armature 41 is seated on the valve seat 43 is the point at which the maximum counter electromotive force is generated.

  In FIG. 3, the time interval between the energization end time tp2 and the seating time ta1 is expressed as a first valve closing time CT1. The first valve closing time CT1 indicates the valve closing time of a new central product that serves as a reference, and serves as a reference value for the valve closing time CT at the time of manufacture. The new center product is a reference product having a reference value for the valve closing time CT in the unused fuel injection valve 2.

In the embodiment of the present invention, the counter electromotive current is detected by the current monitor circuit 12, and the detection signal is input to a microcomputer (not shown) that constitutes the electronic control unit 4. Then, the valve closing time CT of the fuel injection valve 2 can be acquired by the difference between the energization end time tp2 and the seating time ta1.
The above-described times tp1, tp2,... Are determined based on the timing at which the piston (not shown) in the engine 3 is at the top dead center.

Next, an example will be described in which the valve closing time CT of the fuel injection valve 2 deviates from a reference value that is a new central product due to individual variation.
A seating time ta2 indicated by a broken line in FIG. 3 indicates an energization waveform of the fuel injection valve 2 in which the valve closing time CT is deviated from the reference value of the new center product.
That is, the armature 41 is seated on the valve seat 43 from the maximum lift position over a time longer than the reference first valve closing time CT1. The seating time ta2 at this time is shifted to the right in FIG. 3 from the standard seating time ta1 of the new center product. The second valve closing time CT2 at this time is represented by the time interval between the energization end time tp2 and the seating time ta2, and is longer than the first valve closing time CT1.

The cause of variation among individuals in the valve closing time CT can include variations in the lift amount of the armature 41, differences in operating resistance of the sliding portions, and the like.
Here, the difference between the first valve closing time CT1 that is the reference value of the new central product of the valve closing time CT and the second valve closing time CT2 that deviates from the reference value due to variations or the like is defined as a valve closing time difference ΔCT. .

The valve opening time VOT1 of the new center product is represented by the time from the lift start time tp3 at which the armature 41 starts to lift to the seating time ta1. Further, the valve opening time VOT2 of the fuel injection valve 2 that deviates from the reference value of the new central product is represented by the time from the lift start time tp3 at which the armature 41 starts to lift to the seating time ta2.
In the case shown in FIG. 3, the energization time ET is common to the two fuel injection valves 2, but due to the different valve closing time CT, a difference occurs between the valve opening time VOT1 and the valve opening time VOT2, and the fuel injection amount differs. It will end up.

<Relationship between fuel pressure (rail pressure P), energization time ET, and valve closing time CT>
Here, the relationship between the energization time ET and the valve closing time CT when the fuel injection valve 2 is filled with the fuel pressure (rail pressure P) being changed will be described with reference to FIG.
FIG. 4 is a schematic diagram showing the relationship between the energization time ET and the valve closing time CT of the fuel injection valve according to the embodiment.
FIG. 4 shows the energization time ET to the magnet 40 of the fuel injection valve 2 on the horizontal axis, and the valve closing time that is the time from when the energization time ET ends until the armature 41 is seated on the valve seat 43 on the vertical axis. CT is shown.
Further, the fuel pressure (rail pressure P) charged in the fuel injection valve 2 is measured by dividing it into a plurality of patterns. In FIG. 4, the range of the valve closing time CT when the rail pressure P is 40 MPa is indicated by a solid line, the range of the valve closing time CT when the rail pressure P is 80 MPa is indicated by a broken line, and the range when the rail pressure P is 120 MPa. The range of the valve closing time CT is indicated by a chain line.

  In the example shown in FIG. 4, the fuel injection valve 2 according to the embodiment is in a region where the energization time ET is longer than 400 μs, and the valve closing time CT has a correlation with the fuel pressure. That is, the higher the fuel pressure, the shorter the valve closing time CT.

  This is because when the fuel pressure is increased, the valve member 35 of the fuel injection valve body 30 is slightly expanded outwardly and deformed by the pressure of the fuel filled in the control chamber 36. Then, the valve seat 43 above the control chamber 36 moves relatively upward. Therefore, the lift amount (stroke length) until the armature 41 is seated on the valve seat 43 from the lower surface of the magnet 40 is shortened, and the valve closing time CT is shortened.

  If the energization time ET is increased in the region where the energization time ET is relatively short, 200 to 400 μs, with respect to the region where the energization time ET is relatively long, the valve closing time CT is the maximum value for each fuel pressure line. It increases to Max (ET = about 230 μs). Thereafter, the valve closing time CT starts to decrease from the maximum value Max in a state in which the fuel pressure lines overlap to some extent, and then decreases to the minimum value Min (energization time ET = about 350 μs). When the energization time ET increases beyond 350 μs, it is affected by the fuel pressure, and the lines of the valve closing times CT at the fuel pressures are scattered and do not overlap.

  That is, in the region where the energization time ET is relatively short, ET = 230 to 350 μs, there is a region where the correlation between the valve closing time CT and the fuel pressure change is low. This region is defined as a dead zone of the valve closing time CT with respect to the fuel pressure.

In the region where the energization time ET is relatively short, 200 to 400 μs, when the energization time ET is shorter than 230 μs, the armature 41 falls without reaching the lower surface of the magnet. When the energization time ET is about 230 μs, the dwell time of the armature 41 becomes the maximum and the valve closing time CT shows the maximum value.
When the energization time ET is longer than ET = 230 μs, the armature 41 collides with the armature 41 and the lower surface of the magnet 40 in a compressed state, and rebounds by the repulsive force of the fuel and sits on the valve seat 43. To do. Therefore, the armature 41 moves to the valve seat 43 with the initial speed applied. Therefore, the valve closing time CT is gradually shortened as the energization time ET increases.

  When the energization time ET is in a relatively short region of 230 μs or more and 350 μs or less, the pressure of the fuel filled in the control chamber 36 is reduced by opening the nozzle needle 33. Therefore, the deformed state in which the valve member 35 and the like of the fuel injection valve body 30 are expanded is eliminated, and the valve seat 43 provided above the control chamber 36 returns to the position before the pressure is applied. Then, the lift amount (stroke length) until the armature 41 is seated on the valve seat 43 from the lower surface of the magnet 40 returns to the length before the fuel pressure is applied, the valve closing time CT and the fuel pressure (rail pressure P). ) Correlation with change is low.

  Further, when the energization time ET is longer than 400 μs, the armature 41 once contacts the lower surface of the magnet 40 and sits on the valve seat 43 after the magnet 40 is de-energized. In the region of the energization time ET, the pressure of the fuel filled in the control chamber 36 is restored, and the valve member 35 and the like of the fuel injection valve body 30 are in a deformed state. For this reason, as described above, the valve closing time CT is affected by the lift amount (stroke length) of the armature 41 and changes depending on the fuel pressure (rail pressure P).

<How to adjust the lift amount of the armature 41>
Adjustment of the lift amount of the armature 41 can be performed by rotating the adjustment nut 47, for example.
FIG. 5 is a perspective view of the fuel injection valve according to the embodiment.
FIG. 6 is a sectional view showing the lift amount of the armature according to the embodiment.
As shown in FIG. 5, the lift amount of the armature 41 is adjusted by rotating the adjustment nut 47. When the adjustment nut 47 is rotated, the magnet 40 moves in the axial direction of the fuel injection valve 2, so that the separation distance between the upper surface of the armature 41 and the lower surface of the magnet 40 is relatively changed as shown in FIG. The For example, as described in FIG. 3, in the case of the fuel injection valve 2 in which the lift amount of the armature 41 is large in the initial state and the fuel injection amount is increased by the valve closing time CT being longer than the reference value, As shown in FIG. 6, the armature 41 is changed so that the lift amount becomes small. Then, the valve closing time CT is shortened, the fuel injection amount is decreased, and the fuel injection amount can be adjusted within the reference value.

<Method for adjusting valve closing time CT>
Next, a method for adjusting the valve closing time CT of the fuel injection valve 2 will be described.
In the method of manufacturing the fuel injection valve 2 according to the embodiment, the valve closing time CT is adjusted in a state where the fuel injection valve 2 is filled with fuel.
FIG. 7 is an adjustment flowchart of the lift amount of the armature according to the embodiment.

First, in step 1, the assembly of the fuel injection valve 2 is started.
When the temporary assembly of the fuel injection valve 2 is completed in step 2, the process proceeds to step 3.
In step 3, the valve closing time CT is measured in a dry state, and the lift amount of the armature 41 is temporarily adjusted.
In step 4, the assembly of the fuel injection valve 2 is completed.
Proceeding to step 5, the fuel injection valve 2 is attached to the injection amount measuring device.

  In step 6, the fuel injection valve 2 is warmed up, and the high-pressure flow path of the fuel injection valve 2 is filled with high-pressure fuel (wet state). The high pressure flow path refers to the control chamber 36, the flow path 38, the nozzle sheet portion 39, and the like communicating with the high pressure connection portion 37. Of these, at least the control chamber 36 is filled with high pressure fuel as a wet state. To do. By supplying high-pressure fuel to the high-pressure connection 37 of the fuel injection valve 2, the fuel injection valve 2 is brought into the same pressure state as that during operation. At this time, the magnet 40 is not energized and fuel is not injected.

  Proceeding to step 7, the energization time ET to the magnet 40 is set. The energization time ET to the magnet 40 is set to, for example, ET = 230 μs or more and 350 μs or less, which is a dead zone of the valve closing time CT with respect to the fuel pressure shown in FIG. This is because by measuring the valve closing time CT within the dead zone of the valve closing time CT with respect to the fuel pressure as described above, the accurate valve closing time CT can be measured without being influenced by the fuel pressure. .

  Next, the process proceeds to step 8 where energization of the magnet 40 is started, and energization of the magnet 40 is stopped after the energization time ET set in step 7 has elapsed.

  Proceeding to step 9, the valve closing time CT is measured. As described above, the counter electromotive current generated in the magnet 40 when the solenoid valve 32 is closed is detected. Then, the time from when the energization to the magnet 40 is stopped to the time when the back electromotive force is generated is measured as the valve closing time CT.

  Next, the routine proceeds to step 10 where the lift amount of the armature 41 is fully adjusted. The lift amount of the armature 41 is adjusted so that the valve closing time CT measured in step 9 is, for example, within a predetermined reference value of the new center product.

Next, the routine proceeds to step 11 where the fuel injection amount is measured. When the injection amount is within the reference value, the process proceeds to step 12 and the assembly of the fuel injection valve 2 is finished.
When the injection amount measured in step 11 is outside the reference value, the process proceeds to step 13 where only the nozzle side of the fuel injection valve 2 is disassembled.
Next, the routine proceeds to step 14 where the disassembled parts of the fuel injection valve 2 are cleaned.
Proceeding to step 15, the fuel injection valve 2 is reassembled.
Proceeding to step 16, the fuel injection valve is warmed up again, and high pressure fuel is filled inside. Then, returning to step 11, the fuel injection amount is measured again.

<Effect>
According to the method for manufacturing the fuel injection valve 2 according to the embodiment, the fuel injection amount is adjusted in the wet state on the assumption of the operation (wet state). Thus, the fuel injection amount does not differ between the two, and an accurate injection amount can be obtained during operation.
In addition, by setting the energization time ET within the dead zone of the valve closing time CT with respect to the fuel pressure and measuring the valve closing time CT, the accurate valve closing time CT can be measured without being influenced by the fuel pressure. Can do.
Further, when the injection amount is measured and becomes defective, the lift amount of the armature 41 has been adjusted in the wet state, and therefore, the portion that needs to be readjusted is limited to, for example, only the nozzle side other than the lift amount related to the armature 41. The Then, since the decomposition | disassembly location of the fuel injection valve 2 is limited, the loss on the process at the time of manufacture can be reduced.

  1 common rail, 2 fuel injection valve, 3 engine, 4 electronic control unit, 5 supply pump, 6 metering valve, 7 high pressure pump, 8 return valve, 9 fuel tank, 11 pressure sensor, 12 current monitor circuit, 30 fuel injection valve Main body, 31 Nozzle body, 32 Solenoid valve, 33 Nozzle needle, 33a Nozzle spring, 34 Valve piston, 35 Valve member, 36 Control chamber, 37 High pressure connection part, 38 Flow path, 39 Nozzle seat part, 40 Magnet, 41 Armature, 42 Guide part, 43 Valve seat, 44 Orifice, 45 Valve spring, 46 Power supply connection part, 47 Adjustment nut, 50 High pressure pump device, CT valve closing time, ET energization time, P rail pressure.

Claims (7)

Filling the high pressure flow path of the fuel injection valve with fuel;
A step of setting an energization time from the start of energization to the magnet of the solenoid valve until the energization is stopped;
Starting energization of the magnet;
Stopping energization of the magnet;
Measuring the valve closing time until the peak value of the counter electromotive force is generated in the magnet after stopping energization of the magnet;
Adjusting the lift amount of the armature so that the valve closing time corresponding to the energization time becomes a reference value;
A method for manufacturing a fuel injection valve.   2. The method for manufacturing a fuel injection valve according to claim 1, wherein the energization time is set in a dead zone where the valve closing time is not affected by the pressure of fuel filling the high-pressure channel.   The fuel dead valve manufacturing method according to claim 2, wherein the dead zone is defined as an energization time between a maximum value and a minimum value having the valve closing time with respect to a change in the energization time.   4. The method of manufacturing a fuel injection valve according to claim 2, wherein the dead zone energization time includes a value of 230 μs to 350 μs. 5.   After the step of adjusting the lift amount of the armature, there is a step of measuring the fuel injection amount. When the measured fuel injection amount does not satisfy the reference value, only the nozzle body of the fuel injection valve is disassembled, cleaned, The method for manufacturing a fuel injection valve according to any one of claims 1 to 4, further comprising a step of assembling.   The fuel injection according to any one of claims 1 to 5, further comprising a step of temporarily adjusting a lift amount of the armature with the high-pressure flow path empty before the step of filling the high-pressure flow path with fuel. Manufacturing method of valve. The method for manufacturing a fuel injection valve according to claim 1, wherein the lift amount of the armature is adjusted by rotating an adjustment nut that changes a position of the magnet.

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