JP4038636B2 - Method for manufacturing electromagnetic valve seating plate and fuel injection valve using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing an electromagnetic valve seating plate provided in a fuel injection valve of an internal combustion engine (hereinafter, the internal combustion engine is referred to as an “engine”), and a fuel injection valve using the same.
[0002]
[Prior art]
Conventionally, high-pressure fuel supplied from a high-pressure fuel supply pump is accumulated on a common rail, etc., and is supplied to the fuel injection valve after being stored at a constant pressure, and is provided on the opposite injection hole side of the valve member that opens and closes the injection hole of the fuel injection valve There is known a fuel injection device that adjusts the fuel pressure in the pressure control chamber by controlling a solenoid valve to adjust the fuel injection timing and the fuel injection amount. As such a fuel injection device, one disclosed in Japanese Patent Laid-Open No. 9-42106 is known.
[0003]
The electromagnetic valve seating plate of the accumulator fuel injector disclosed in Japanese Patent Application Laid-Open No. 9-42106 is provided with a tapered portion around the flow passage through which the fuel flows, and a flow passage is provided at the upper end of the tapered portion. A seat surface is formed on which a valve member of the electromagnetic valve to be opened and closed can be seated. A spherical member whose seating surface side is flat is provided at the tip of the valve member of the electromagnetic valve, and the spherical member and the seating surface are brought into close contact with each other so that the space between the spherical member and the seating surface can be reduced. It has a structure that prevents fuel leakage.
[0004]
The electromagnetic valve seating plate on which the flat seating surface as described above is formed can be manufactured by the following process.
(1) A tapered portion, an annular groove formed around the tapered portion, and a fuel groove formed radially around the tapered portion are formed on the upper surface of the plate material formed by cutting or the like.
(2) A flow passage is formed at the center of the tapered portion.
(3) The plate material that has completed the steps (1) and (2) is heat-treated.
(4) Roughly grind the upper and lower surfaces of the heat-treated plate material.
(5) Finish grinding the roughened ground surface of the plate material.
[0005]
[Problems to be solved by the invention]
A solenoid valve of a fuel injection device as disclosed in Japanese Patent Application Laid-Open No. 9-42106 is for precisely controlling the fuel injection amount and injection timing to prevent fuel leakage from between the spherical member and the seat surface. It is necessary to process each member with high accuracy. And it is necessary to improve the dimensional accuracy of a flow path and a taper part, and to ensure the coaxiality of a flow path and a taper part.
[0006]
Fine shapes such as a tapered portion, an annular groove, and a fuel groove formed on the upper surface of the plate material are formed by cutting or die-sinking electric discharge machining or the like. However, although both cutting and die-sinking electric discharge machining have high machining accuracy, there are problems that the time required for machining is long and the production efficiency is low.
[0007]
Further, as a method for forming the flow passage, drilling or drilling by electric discharge machining can be used. However, when the plate material is fixed to the work table to form a flow path, the plate material itself is fixed to the work table because the outer shape of the plate material itself or the fixing position of the plate material to the work table is slightly different. It is difficult to keep the position strictly constant. Therefore, it is difficult to maintain the flow passage formation position with the required accuracy.
[0008]
In order to ensure the coaxiality between the flow passage and the tapered portion, a dedicated processing device that combines the formation of a fine shape such as the tapered portion, the annular groove, and the fuel groove and the perforation of the flow passage is utilized, It is desirable to process the plate material on a single processing table. However, if a dedicated processing device is developed and used, there is a problem that the manufacturing cost of the electromagnetic valve seat plate increases.
[0009]
Furthermore, when forming the seat surface, since the taper portion is provided around the flow passage, the outer diameter of the seat surface can be enlarged by grinding the upper end portion of the taper portion to have a predetermined outer diameter. Is possible. Therefore, conventionally, by setting a grinding area in the taper part axial direction on the upper end part side of the taper part and grinding the upper end part of the taper part by a predetermined area, the outer diameter of the seating surface is adjusted and the desired outer diameter is secured. Was. However, if rough grinding is performed on the upper and lower surfaces of the plate material in the pretreatment process to set the processing reference surface of the plate material, the grinding range of the upper and lower surfaces differs slightly for each plate material. Even if it grinds, the outer diameter of a seat surface varies and there is a problem that it is difficult to secure desired dimensional accuracy.
[0010]
As described above, when it is difficult to ensure the dimensional accuracy, it is possible to improve the dimensional accuracy by measuring the image of the processed portion. For example, as a method of calculating the outer diameter of a circular portion by image measurement, a boundary portion of an image of a circular portion input from a camera or the like is measured at a plurality of points such as three or four points, and the coordinates of the measured plurality of points There is a method for calculating the diameter. However, in the case of the electromagnetic valve seating plate as described above, the measurement site is the upper end portion of the tapered portion, and therefore the unevenness of the boundary portion is severe. For this reason, there is a problem that measurement error increases in several points of measurement and it is difficult to ensure measurement accuracy.
[0011]
Accordingly, an object of the present invention is to provide an electromagnetic valve seating plate that can ensure desired dimensional accuracy and coaxiality of a flow passage and a tapered portion without increasing manufacturing costs, and can improve production efficiency. A manufacturing method and a fuel injection valve using the same are provided.
[0012]
[Means for Solving the Problems]
According to the method for manufacturing a solenoid valve seating plate according to claim 1 or 2 of the present invention, image measurement is used to grind in the taper portion axial direction so that the upper end portion of the taper portion has a predetermined outer diameter and image measurement. Is used to measure the center position of the upper end of the taper and form a flow passage through the plate material at the center. Even when grinding of the upper end of the tapered part and formation of the flow path are performed by different processing devices by using image measurement for cutting and formation of the flow path, the desired dimensional accuracy and the coaxiality of the flow path and the seating surface Can be secured. In addition, for example, an existing cutting device or a drilling device can be used for cutting the taper portion and forming the flow passage, so there is no need to develop and use a dedicated processing device that combines cutting and drilling. The manufacturing cost of the electromagnetic valve seating plate does not increase.
[0013]
Further, since the taper portion, the annular groove, and the fuel groove are formed by press molding, for example, machining can be performed in a short time as compared with cutting or die-sinking electric discharge machining, and the production efficiency can be improved. Since the seating surface and the flow passage are processed using image measurement, a desired dimensional accuracy can be ensured.
[0014]
According to the method for manufacturing the electromagnetic valve seating plate of the first aspect of the present invention, the grinding region in the taper portion axial direction of the upper end portion of the taper portion is determined using image measurement. Then, the upper end portion of the tapered portion is ground to the determined grinding region to form a seating surface. After the grinding of the upper end surface of the tapered portion is completed, the position of the center of the seating surface is measured using image measurement, and a flow passage that penetrates the plate material is formed based on the measured position of the center. After grinding the upper end of the tapered portion to a predetermined outer diameter and forming the seating surface, when the image of the position of the center of the seating surface is measured, the planar shape of the seating surface of the upper end of the tapered portion is almost circular, The position of the center of the seating surface can be determined more accurately. Therefore, the coaxiality of the flow path and the seating surface can be ensured.
[0015]
According to the method for manufacturing a solenoid valve seating plate according to claim 3 or 4 of the present invention, an image input by image measurement is binarized. If, for example, a CCD (Charge Coupled Device) is used as a means for measuring an image by binarizing the input image, the number of pixels of the CCD becomes the number of measurement points. As a result, the number of measurement points increases and the numerical values can be averaged, so that the outer diameter and center coordinates of the upper end of the tapered portion can be measured with high accuracy. Therefore, desired dimensional accuracy and coaxiality of the flow passage and the tapered portion can be ensured.
[0016]
According to the fuel injection valve of the fifth aspect of the present invention, the electromagnetic valve manufactured by the method for manufacturing the electromagnetic valve seating plate according to any one of claims 1 to 4 as the electromagnetic valve seating plate on which the electromagnetic valve is seated. It has a seating plate. Therefore, the desired dimensional accuracy and the coaxiality of the flow path and the seating surface can be ensured without increasing the manufacturing cost, and the production efficiency can be improved.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example showing an embodiment of the present invention will be described with reference to the drawings.
2 to 5 show a solenoid valve seating plate and a fuel injection valve using the same according to the present invention.
The fuel injection valve 1 shown in FIG. 2 is supplied with a high-pressure fuel having a constant pressure accumulated from a common rail (not shown) via a fuel pipe (not shown) through a fuel filter 60.
[0018]
The nozzle needle 12 is accommodated in the nozzle body 11 of the injection nozzle 10 provided at the injection side end of the fuel injection valve 1 so as to be able to reciprocate, and opens and closes the injection hole 13. The nozzle body 11 and the valve body 14 are connected by a retaining nut 16 with a distance piece 15 interposed therebetween. A pressure pin 17 and a control piston 18 that is in contact with or connected to the counter injection hole side of the pressure pin 17 are disposed on the counter injection hole side of the nozzle needle 12. The pressure pin 17 is inserted into the spring 19, and the spring 19 biases the pressure pin 17 downward in FIG. A pressure control chamber 20 is provided on the side opposite to the injection hole of the control piston 18.
[0019]
The high-pressure fuel introduced from the fuel filter 60 into the high-pressure fuel passage 61 is supplied to the fuel reservoir 21 and the pressure control chamber 20 that are annularly formed around the nozzle needle 12. The pressure of the high pressure fuel in the fuel reservoir 21 urges the nozzle needle 12 in the lift direction, and the pressure of the high pressure fuel in the pressure control chamber 20 urges the control piston 18 downward in FIG.
[0020]
The electromagnetic valve 30 is an electromagnetic two-way valve that intermittently connects the pressure control chamber 20 and the low pressure side. A plate 50 as a solenoid valve seating plate and a cylinder 22 are connected to the valve body 14 by a retaining nut 23, and a core 31 of the solenoid valve 30 is caulked to the end of the retaining nut 23.
[0021]
The electromagnetic coil 32 is wound around the core 31, and power is supplied from the connector 24. Further, a fuel passage 26 is formed in the nut 25, and excess fuel in the fuel injection valve 1 is discharged through the low-pressure fuel passages 64, 65, 66.
The fuel passage 62 is a low pressure fuel passage for collecting leaked fuel from the sliding clearance of the control piston 18 and the nozzle needle 12, and communicates with the low pressure fuel passage 26.
[0022]
As shown in FIG. 3, the valve member 34 of the electromagnetic valve 30 includes a shaft 341 and a spherical member 342. The shaft 341 is supported on the inner wall of the cylinder 22 so as to be able to reciprocate. The spherical member 342 is slidably supported at the tip of the shaft 341. An armature 35 is fixed to the electromagnetic coil 32 side of the shaft 341. When the electromagnetic coil 32 is not energized, the spherical member 342 is seated on the flat valve seat 51 of the plate 50 by the biasing force of the spring 36. One end of the spring 36 is locked to the armature 35. When the electromagnetic coil 32 is energized, the armature 35 is attracted to the electromagnetic coil 32 by the magnetic force generated in the electromagnetic coil 32, and the shaft 341 is lifted upward in FIG. 3, so that the spherical member 342 is separated from the flat valve seat 51.
[0023]
The high pressure fuel passage 61 and the pressure control chamber 20 communicate with each other through a throttle hole 63 that regulates the amount of fuel flowing from the high pressure fuel passage 61 into the pressure control chamber 20. A flow path 52 having a flow resistance smaller than that of the throttle hole 63 is formed in the plate 50 so as to penetrate the plate 50 in the axial direction. When the valve member 34 composed of the shaft 341 and the spherical member 342 is separated from the flat valve seat 51, the flow passage 52 and the low-pressure fuel passage 64 communicate with each other, and the flow passage 52, the low-pressure fuel passage 64, the low-pressure fuel chamber 65, the low-pressure fuel The high pressure fuel in the pressure control chamber 20 is discharged from the fuel injection valve 1 through the passages 66, 67, 68 and 26.
[0024]
As shown in FIG. 3, a support portion 341 a is provided at the tip portion of the shaft 341, and the spherical member 342 is prevented from falling off the shaft 341 by caulking the tip portion of the support portion 341 a. Since a clearance of several μm is provided between the support portion 341a and the spherical member 342, the spherical member 342 is slidably assembled to the shaft 341.
[0025]
Next, the plate 50 will be described in detail.
As shown in FIGS. 2 and 3, the plate 50 is sandwiched between the cylinder 22 and the valve body 14. A flow passage 52 that penetrates the plate 50 in the axial direction is formed in the plate 50, and the pressure control chamber 20 and the low-pressure fuel passage 64 can communicate with each other.
[0026]
As shown in FIG. 4, a truncated cone part 50a is formed at the center of the plate 50, and a finely shaped part is provided at the center of the truncated cone part 50a. The finely shaped portion includes a tapered portion 53, an annular groove 54, and a fuel groove 55. As shown in FIG. 5, the tapered portion 53 is provided around the flow passage 52 so that the outer diameter increases from the spherical member 342 side of the valve member 34, that is, from the upper end portion 531 to the antispherical member side.
[0027]
As shown in FIGS. 4 and 5, the annular groove 54 is formed on the outer peripheral side of the tapered portion 53 so as to be concentric with the flow passage 52. Further, a plurality of fuel grooves 55 are radially formed from the annular groove 54 toward the radially outer side with the tapered portion 53 as the center. In this embodiment, four fuel grooves 55 are formed in a cross shape. One end of the fuel groove 55 communicates with the annular groove 54, and the other end of the fuel groove 55 communicates with the outer peripheral groove 56. The outer peripheral groove 56 is formed around the truncated cone part 50a.
[0028]
As shown in FIG. 5, the flat valve seat 51 includes a seat surface 511 formed on the upper end portion 531 of the taper portion 53 and a seat surface 512 around the annular groove 54. An end portion on the low pressure side of the flow passage 52 is opened at the center of the seat surface 511.
The planar portion 342a of the spherical member 342 can be seated on the planar valve seat 51 including the seating surface 511 and the seating surface 512, and the spherical member 342 is seated on the planar valve seat 51, whereby the fuel flow in the flow passage 52 is blocked. The
[0029]
Next, the manufacturing method of the plate 50 is demonstrated in detail based on the flowchart of FIG.
(1) Material cutting (S101)
The outer shape of the plate 50 and the outer circumferential groove 56 and the like are formed by cutting or cutting off the material used as the material of the plate 50 to obtain a plate material 70 as shown in FIG.
[0030]
(2) Pressing process (S102)
A tapered portion 53, an annular groove 54, and a fuel groove 55 that are finely shaped as shown in FIG. 4 are formed on the upper surface 71 of the formed plate material 70 by press working.
[0031]
(3) Heat treatment process (S103)
The plate material 70 obtained by press-molding the fine shape portion is heat-treated.
(4) Rough grinding process (S104)
The upper surface 71 and the lower surface 72 of the heat-treated plate material 70 are roughly ground to secure the lower surface 72 of the plate material 70 as a processing reference surface, and the upper end portion 531 of the tapered portion 53 is temporarily formed. By temporarily forming the upper end portion 531 of the taper portion 53, the planar shape of the taper portion 531 becomes almost circular and the roundness is ensured, so that the next image measurement can be performed accurately.
[0032]
(5) Taper diameter image measurement process (S105)
As shown in FIG. 7, the temporarily formed plate material 70 is fixed to the processing table 81 by the fixing device 811, and the upper end portion 531 of the tapered portion 53 is image-measured by the CCD camera 91.
By this image measurement, the outer diameter d of the upper end portion 531 of the tapered portion 53 after completion of the rough grinding process is calculated as shown in FIG. FIG. 9 shows a process for calculating the outer diameter d.
[0033]
In step S501 (hereinafter simply “S501” for simplicity), an image of the CCD camera 91 is input. The input of the image is performed by reflecting light emitted toward the plate material 70 from a light source (not shown) by the upper end portion 531 of the tapered portion 53 and capturing the reflected light by the CCD camera 91.
[0034]
In S502, the image data input in S501 is binarized. In S503, the number of pixels corresponding to the upper end portion 531 of the tapered portion 53 is counted based on the binarized data. Then, the area S of the upper end portion 531 of the tapered portion 53 is calculated from the counted number of pixels by a predetermined conversion coefficient.
[0035]
In S504, the outer diameter d of the upper end portion 531 of the tapered portion 53 is calculated based on the area S calculated in S503. The outer diameter d is from the area S,
d = 2 × (S / π) ^1/2
Calculate as
[0036]
Then, the machining allowance h, which is a grinding region in the taper portion axial direction, is set so that the outer diameter d of the upper end portion 531 measured as shown in FIG. 8 becomes the preset upper end outer diameter D. The machining allowance h is θ ° as the inclination angle of the taper portion.
h = tan θ × (D−d) / 2
It can be obtained more.
[0037]
(6) Upper end finish grinding process (S106)
Based on the machining allowance set in (5) above, the tapered portion 53 is finish ground by controlling the grindstone 92 connected to the NC machine tool (not shown) as shown in FIG. Form.
[0038]
(7) Flow path position determining step (S107)
As shown in FIG. 11, the plate material 70 that has been subjected to finish grinding is fixed to a processing table 82 different from (5) by a fixing device 821, and the formed seating surface 511 is image-measured by a CCD camera 93. FIG. 13 shows a calculation process for calculating the center position p of the seating surface 511 shown in FIG. 12 by this image measurement.
[0039]
Steps S701 (hereinafter simply referred to as “S701”) to S704 are the same as those in the flowchart shown in FIG. Although the desired outer diameter D of the taper portion 53 upper end portion 531, that is, the seating surface 511 is secured in the above (5) taper portion diameter image measurement step and (6) upper end finish grinding step, the seat is again seated in S 703 and S 704. The reason why the outer diameter D of the surface 511 is measured is to check whether the outer diameter of the seating surface 511 formed by a series of processing steps has a desired dimension and to further improve the accuracy. When the plate material 70 whose measured outer diameter D is not a desired dimension is generated, a pre-process inspection, for example, a check of the CCD camera 91 that performs image measurement or a check of the polishing performance of the grindstone 92 is performed.
[0040]
In S705, the center position p of the seating surface 511 is measured and determined. Here, as shown in FIG. 12, the CCD camera 93 images the vicinity of the seating surface 511 at the center of the plate material 70. However, there may be a deviation Lx in the X-axis direction and a deviation Ly in the Y-axis direction from the virtual center P that is the photographing center of the CCD camera 93 to the center position p of the seating surface 511. When such a deviation exists, it is necessary to eliminate the deviation and specify the center position p of the seating surface, that is, the position where the flow passage 52 is formed. The virtual center P is also the initial position of the electrode 94 used in the next process.
[0041]
The center position p of the seating surface 511 is specified by calculating as follows.
As shown in FIG. 12, the image photographed by the CCD camera 93 is recognized as image information as shown in FIG. 14, and the total number of pixels N corresponding to the seating surface 511 is counted from the image information. Then, the coordinates of the pixels belonging to the position corresponding to the seating surface 511 are all added for each X coordinate and each Y coordinate, and the added value of the X coordinate and the Y coordinate is divided by the total number N of pixels. That is, the center position p of the seating surface 511 can be calculated by calculating the average value of the X and Y coordinates of the pixels belonging to the position corresponding to the seating surface 511.
[0042]
The deviation between the center position p calculated as described above and the virtual center P, Lx and Ly are calculated, and the formation position of the flow passage 52 (that is, the center position p of the seating surface 511) is determined. Since the center position p of the seating surface 511 is obtained from the number of measurement points equal to the number of pixels of the CCD camera 93 as described above, the coordinates of the center position p can be calculated with high accuracy.
[0043]
(8) Flow path forming step (S108)
As shown in FIG. 15, the electrode 94 connected to the NC machine tool (not shown) is moved based on the deviations Lx and Ly from the virtual center measured in (7), and the flow path 52 is formed in the center of the seating surface 511 by electric discharge machining. To form.
[0044]
▲ 9 ▼ Bottom finish grinding process (S109)
The lower surface 72 of the plate material 70 in which the flow path 52 is formed is ground so that the plate material 70 has a predetermined thickness.
[0045]
As described above, in the present embodiment, after measuring the image of the taper portion 53, the upper end portion 531 of the taper portion 53 is ground, and the position of the flow passage 52 is determined by image measurement of the seating surface 511 of the upper end portion 531 of the ground taper portion 53. Thus, the flow passage 52 was formed. However, after grinding the taper portion 53 upper end portion 531, the position of the flow passage 52 is determined by measuring the center of the taper portion 53 upper end portion 531 to form the flow passage 52. It is also possible to produce the plate 50 by grinding to form the seating surface 511. However, when the flow path 52 is formed after the taper portion 53 is ground, since the upper end portion 531 of the taper portion 53 after grinding is substantially circular as described above, the roundness is ensured. It goes without saying that the position of the flow passage 52 can be determined more accurately by image measurement.
[0046]
As described above, in this embodiment, the grinding allowance to be a grinding region in the taper portion axial direction of the upper end portion 531 of the taper portion 53 is determined using image measurement by the camera 91. Similarly, the position of the center of the seating surface 511 is measured using image measurement by the camera 93, and the flow path 52 is formed at the position of the measured center. Accordingly, the grinding of the upper end portion 531 of the tapered portion 53 and the formation of the flow passage 52 can be performed by different processing apparatuses. Further, since it is possible to carry out the processing with the existing cutting device and punching device without developing a new processing device that combines the grinding of the upper end portion 531 and the formation of the flow passage 52, the capital investment or the plate 50 and The manufacturing cost of the fuel injection valve 1 can be reduced.
[0047]
Even if grinding of the upper end portion 531 of the tapered portion 53 and formation of the flow passage 52 are performed by different processing apparatuses, the grinding allowance or the formation position of the flow passage 52 is determined by image measurement, so that the desired dimensional accuracy can be obtained. The flow passage 52, the tapered portion 53, the seating surface 511, and the like can be formed, and the coaxiality of the flow passage 52 and the seating surface 511 can be ensured.
[0048]
Further, since the image measurement is performed by the CCD cameras 91 and 93, the outer diameter of the upper end portion 531 of the tapered portion 53 and the center position of the seating surface 511 are calculated by the same number of measurement points as the number of pixels of the CCD cameras 91 and 93. Can do. Therefore, since the number of measurement points increases, the calculation accuracy of the center position of the taper part 53 upper end part 531 and the seating surface 511 by image measurement can be improved.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a method of manufacturing a solenoid valve seating plate according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a fuel injection valve according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a main part of a fuel injection valve according to an embodiment of the present invention.
4A is a plan view showing a solenoid valve seating plate according to an embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along line BB in FIG. 4A.
5A is a plan view showing the main part of a solenoid valve seating plate according to an embodiment of the present invention, and FIG. 5B is a cross-sectional view taken along line BB in FIG. 5A.
FIGS. 6A and 6B are plan views, and FIG. 6B is a BB line of FIG. 6A, showing a plate material in a state before a finely shaped portion is formed on a solenoid valve seating plate according to an embodiment of the present invention; It is sectional drawing cut | disconnected by.
FIG. 7 is a schematic diagram showing taper diameter image measurement of a solenoid valve seating plate according to an embodiment of the present invention.
FIG. 8 is an explanatory view of a grinding region as a grinding allowance for a solenoid valve seating plate according to an embodiment of the present invention.
FIG. 9 is a flowchart showing a step of calculating an outer diameter of the upper end portion of the tapered portion in the tapered portion diameter image measuring step.
FIG. 10 is a schematic view showing upper end finish grinding of a solenoid valve seating plate according to an embodiment of the present invention.
FIG. 11 is a schematic view showing image measurement of the flow path position of the electromagnetic valve seating plate according to one embodiment of the present invention.
FIG. 12 is a view showing an image of the vicinity of the seating surface of the electromagnetic valve seating plate photographed by the camera in the flow path position determining step, and showing the photographing center of the camera and the center of the seating surface.
FIG. 13 is a flowchart showing a calculation step of calculating the center position of the seating surface in the flow path position determination step.
FIG. 14 is a diagram for explaining a method of calculating the center position of the seating surface in the flow path position determining step.
FIG. 15 is a schematic view showing the formation of a flow path of a solenoid valve seating plate according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel injection valve 10 Injection nozzle 12 Nozzle needle 13 Injection hole 18 Control piston 20 Pressure control chamber 30 Electromagnetic valve 32 Electromagnetic coil 34 Valve member 50 Plate (Electromagnetic valve seating plate)
51 Flat valve seat 52 Flow passage 53 Tapered portion 54 Annular groove 55 Fuel grooves 64, 66, 67, 68 Low pressure fuel passage 65 Low pressure fuel chamber 70 Plate material 511 Seat surface 512 Seat surface 531 Upper end

Claims (5)

A flow passage through which the fuel can flow, a tapered portion provided around the flow passage, a seating surface on which a valve member formed at an upper end portion of the tapered portion for opening or closing the flow passage can be seated, and a concentric circle with the flow passage An annular groove formed around the tapered portion and a plurality of fuel grooves formed radially around the tapered portion, and provided in a fuel injection valve of a pressure accumulating fuel injection device A method of manufacturing a seating plate,
A pressing step of press-molding the taper portion, the annular groove, and the fuel groove on the upper surface of the plate material molded into a predetermined outer shape;
A heat treatment step of heat-treating the plate material that has completed the pressing step;
A rough grinding step of rough grinding the upper and lower surfaces of the heat-treated plate material;
The outer diameter of the upper end of the tapered portion of the plate material that has completed the rough grinding process is image-measured , and a grinding region in the taper portion axial direction is determined based on the measured outer diameter, and the outer periphery of the upper end of the tapered portion is determined. After forming the seat surface by grinding the taper portion upper end surface in the taper portion axial direction to a grinding region determined to be a seat surface of a predetermined outer diameter, after forming the seat surface on the plate material, An image measurement processing step of measuring the center of the seating surface from the outer diameter of the seating surface, determining a position of the flow passage at the center, and forming a flow passage penetrating the plate material based on the position ;
A bottom surface finishing grinding step of grinding the bottom surface of the plate material so that the plate material in which the flow path is formed has a predetermined thickness;
The manufacturing method of the plate for electromagnetic valve seating characterized by including. The formation of the flow path in the image measurement processing step is perforation by electric discharge machining. 1 A method for producing the described solenoid valve seating plate. The image measurement of the outer diameter D of the upper end portion of the taper portion in the image measurement processing step is performed by binarizing an image input by image measurement of the upper end portion of the taper portion and measuring the shape of the upper end portion of the taper portion. An area S of the upper end portion of the tapered portion is calculated based on the shape of the upper end portion of the tapered portion, and an outer diameter D of the upper end portion of the tapered portion is calculated based on the calculated area of the upper end portion of the tapered portion.
D = 2 × (S / π) ^1/2
The method for manufacturing a solenoid valve seating plate according to claim 1, wherein the calculation is performed by: The image measurement of the position of the center of the upper end of the tapered portion in the image measurement processing step is performed by binarizing the image input by the image measurement of the upper end of the tapered portion and measuring the shape of the upper end of the tapered portion. The average value of the X coordinate and the Y coordinate of the pixel to which the upper end portion of the tapered portion belongs is calculated as the center coordinate of the upper end portion of the tapered portion based on the shape of the upper end portion of the tapered portion. 4. The method for producing a solenoid valve seating plate according to any one of 3 above A fuel injection valve that injects high-pressure fuel accumulated in a common rail into a combustion chamber provided for each cylinder of a diesel internal combustion engine,
  A nozzle needle that interrupts the nozzle hole;
  A control piston provided on the side opposite to the nozzle hole of the nozzle needle so as to be capable of reciprocating with the nozzle needle;
  A coil that generates a magnetic force when energized, and a valve member that is attracted by the magnetic force generated by the coil; and the control piston is injected by the fuel pressure provided on the side opposite to the injection hole of the control piston. A solenoid valve for intermittently connecting the pressure control chamber energized in the hole closing direction and the low pressure fuel passage or the low pressure fuel chamber;
  The electromagnetic valve seating plate manufactured by the method for manufacturing the electromagnetic valve seating plate according to any one of claims 1 to 4, wherein the valve member can be seated;
  A fuel injection valve comprising:

Images