JP2568323B2 - Nozzle with valve seat, method of manufacturing the same, and solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve, a nozzle with a valve seat, and a method of manufacturing the nozzle suitable for use as a fuel injection valve (injector) of an automobile engine, for example.

[0002]

2. Description of the Related Art In an electromagnetic fuel injection valve, a valve seat is disposed upstream of an injection hole of a fuel injection nozzle, and a valve body is reciprocated in the axial direction with respect to this valve seat by excitation and demagnetization of an electromagnetic coil. The valve body and the valve seat are configured to be in contact with and separated from each other (valve closed, valve open).

FIG. 9 shows various types of conventional valve seats used for this type of electromagnetic fuel injection valve.

In FIG. 9, (a) shows a valve seat 2a formed in a nozzle 1 having a single conical surface (a valve seat of this type is disclosed, for example, in Japanese Utility Model Laid-Open No. 60-194167).
(B) is a spherical concave surface 2c having a curvature radius equal to that of the valve body 3 at a portion of the valve seat that comes into contact with the spherical valve body 3 when the valve is closed, and a downstream portion thereof has a smaller radius of curvature than the valve body 3. Spherical concave surface 2b (this type of valve seat is spherical concave surface 2b
The fuel reservoir 2d is formed between the valve body 3 and the minute debris to form a valve seat.
(See , for example, Japanese Unexamined Utility Model Publication No. 55-46576). (C) shows a valve seat 2a having a single conical surface and a tapered fuel injection hole. 4 is smoothly connected (this type of valve seat is disclosed, for example, in Japanese Utility Model Laid-Open Publication No. 60-194166). In any case, the valve body 3 uses a spherical valve body, and the injection hole 4 of the nozzle is formed downstream of the valve seat.

[0005]

In recent years, this type of solenoid valve, particularly a nozzle with a valve seat used for a fuel injection valve of an automobile engine, has been required to have higher and higher metering accuracy, but the conventional solenoid valve does not always meet this requirement. It was not enough. That is, according to the experimental results by the present inventors, the following
Such a phenomenon was confirmed.

For example, as shown in FIG.
Is a single conical surface, the space S2 near the valve seat downstream of the spherical valve element 3 is relatively large, but the generation region of the vortex generated in the space S2 when the valve is opened is proportional to the size of this space. It has been found. Therefore, there is a tendency that the variation in the flow rate of the fuel injected from the fuel injection holes 4 becomes large.

Further, as shown in FIG. 9 (b), the spherical concave surface constituting the valve seat surface is formed in two steps, such as 2c and 2b, and a space serving as a fuel reservoir 2d is provided between the spherical concave surface 2b and the valve body 3. Is formed, spherical concave surfaces 2c and 2b having different curvatures are formed.
In order to extend, there is a step between the spherical concave surfaces 2c and 2b,
Further, the flow path from the fuel reservoir 2d to the fuel injection hole 4 is not smooth, so that the valve seat surface (spherical concave surfaces 2c, 2b)
~ Disturbance in the flow of fuel near the flow path wall over the fuel injection hole 4
A flow is generated, which causes a separation phenomenon of the fuel flow, leading to instability of the fuel spray state and increased cavitation of the fuel.

Further, when the single conical surface 2a and the tapered fuel injection hole 4 are connected by a smooth radius as shown in FIG. 9 (c), the fuel flow separation phenomenon is improved. ,
The space on the downstream side of the valve body 3 increases, and as a result, the same problem as the solenoid valve in FIG. 9A tends to occur.

In particular, in a fuel injection valve in which a fuel swirler (swirler) is disposed upstream of a valve seat, a large fuel swirling force is provided downstream of the valve body 3, so that the vortex generation area is large. However, the above-mentioned problems tend to be conspicuous.

Conventionally, the valve seat is usually processed by grinding, and it is difficult to connect the shape of the valve seat, the fuel injection hole, and the like with a smooth arc curve by grinding. There was a problem that a corner was formed at the boundary between the valve seat and the fuel injection hole, resulting in a fuel separation phenomenon. Conventionally,
In order to prevent such a problem, it is necessary to perform a lapping process after the grinding, which raises the cost and lowers the productivity.

The present invention has been made in view of the above points, and one object of the present invention is to improve the measurement accuracy by suppressing the variation of the fluid injection amount of the solenoid valve by improving the solenoid valve, especially the valve seat therein. It is in. Another is to improve the productivity when manufacturing a nozzle with a valve seat having excellent measurement accuracy as described above.

[0012]

In order to achieve the above object, the present invention basically proposes the following means for solving the problems.

The first means for solving the problem is characterized by the structure of a nozzle with a valve seat used for an electromagnetic valve. The gist of the invention is that the spherical valve element is brought into contact with the valve element by axial reciprocating operation. In a nozzle with a valve seat having a conical valve seat that is separated and a fluid injection hole formed continuously with the valve seat surface downstream of the valve seat, a portion of the valve seat surface that contacts at least the valve body and An upstream side of the contact portion is a conical surface, and a portion adjacent to the conical surface downstream of the contact portion is a spherical concave surface having a radius of curvature smaller than that of the valve body. It has been made continuous through the round surface.

The second object of the present invention is to provide a method of manufacturing a nozzle with a valve seat according to the first object of the present invention. The gist of the present invention is to form a bottomed cylinder to be a nozzle material from a metal material, At the center of the bottom upper surface of the bottomed cylindrical body, at least a portion that comes into contact with the valve body in the first pressing step and an upstream side from the contact portion presents a conical surface, and is adjacent to the conical surface downstream from the contact portion. A valve seat surface whose part is a spherical concave surface having a radius of curvature smaller than that of the valve body is formed, and a fluid injection hole is formed at the center of the tip of the formed surface generated by the first pressing step in the second pressing step. A hole is formed, a corner between the spherical concave surface and the blind hole is round-formed in a third pressing step, and the bottom of the bottomed cylindrical body is formed by punching the blind hole and the series of pressing steps. Cutting the plastic flow part extruded to the lower side Producing nozzle through that process. The conical surface forming and the spherical concave surface forming in the first pressing step may be performed in separate pressing steps.

A third object of the present invention is to provide a method of manufacturing a nozzle with a valve seat, which is an alternative to the second object of the present invention. As a jig, a punch formed by connecting a spherical convex surface (the convex surface has a smaller radius of curvature than the spherical valve body to be used) and a conical surface through a radius after forming a projection at the center of the tip. The punch presses the center of the upper surface of the nozzle bottom while guiding the punch along the inner periphery of the nozzle material, and the valve seat surface and the fluid injection hole by plastic flow are transfer-molded by a press.

[0016]

According to the valve seat having the above structure, the valve seat surface extends from the upstream side to the downstream side.
A conical surface, a spherical concave surface having a smaller radius of curvature than the valve body,
The continuous surface between the concave surface and the round surface between the fuel injection holes
The fuel flow.
The turbulent flow of the fluid flow is suppressed to eliminate the separation phenomenon, and the spherical concave surface (the spherical surface downstream from the contact portion between the spherical valve body and the valve seat surface)
Since the radius of curvature of the conical concave surface is smaller than that of the spherical valve body, the space on the downstream side of the valve body is reduced, and the vortex generation area of the fluid flow can be narrowed. As a result, the fluid ejection is made smooth and the variation in the fluid ejection amount and cavitation are suppressed. In addition, the valve
Even if a spherical concave surface is provided on the seat surface, the valve
Conical surface is secured at the part that comes in contact with the spherical valve body when the valve is closed
Tangent between the spherical valve body and the conical surface when the valve is closed
The valve closing force, which is urged by a spring or the like to the contact portion while securing the contact, is collected.
Intermediate added structural advantages can be maintained.

Operation of the Second Means for Solving the Problems According to the manufacturing method according to the second means for solving the problems, the above-mentioned conical surface, spherical concave surface, round surface, and fuel injection hole are transfer-molded in a series of pressing steps. . Therefore, a high-precision nozzle with a valve seat surface can be manufactured by plastic working without requiring cutting and polishing.

Heretofore, martensitic stainless steel excellent in wear resistance and corrosion resistance has been used as a typical material of the nozzle material. Martensitic stainless steel is generally referred to as a difficult-to-work material that is difficult to perform with high precision plastic working. However, the present inventors already have a mold for valve seat transfer at the tip as a press jig capable of high-precision plastic working even with such difficult-to-work steel materials, and the mold surface has the nozzle We have developed a cemented carbide punch with a ceramic coating that is harder than the material.
By using this, the valve seat surface having the above-mentioned characteristics can be plastically worked even on a difficult-to-work steel material by pressing. In other words, the punch having the special structure enables the transfer molding of the valve seat surface without burning due to the application of the ceramic coating.

For a nozzle material that is not difficult to process, the valve seat and the fuel injection hole can be formed using a normal punch without using the special punch as described above.

Operation of the third problem-solving means: When the punch according to the first problem-solving device is used, the valve seat surface unique to the present invention as described in the first problem-solving device has one pressing step. Transfer molding.

The same applies to the punch used in this case as described in the second means for solving the problems.

[0022]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view of a solenoid valve according to an embodiment of the present invention. FIG. 1 (a) shows a valve seat and a valve body, and FIG. 1 (b) shows a longitudinal section of the entire solenoid valve.

First, an example of the configuration of a solenoid valve to be applied is shown in FIG.
(B).

In this embodiment, a fuel injection valve of an automobile engine is exemplified as the solenoid valve. Main body 11 of fuel injection valve
Is a yoke 14 accommodating the electromagnetic coil 12 with the mold 12a and the core 13, and the nozzle 1 mounted on the lower surface thereof.
Etc.

A passage hole 15 which is a part of a fuel passage is formed in a lower center portion of the yoke 14, and a plunger 16 with a valve element (ball) 3 is inserted into the passage hole 15 via a return spring 18. It is fitted so that it can reciprocate in the axial direction. The return spring 18 urges the valve body 3 so as to contact the valve seat 2 provided on the nozzle 1 when the electromagnetic coil 12 is not energized (during demagnetization). The structure of the valve seat 2 will be described later.

The nozzle 1 has a bottomed cylindrical shape, a valve seat 2 is disposed at the center of the bottom upper surface, and a fuel injection hole 4 is provided downstream of the valve seat. A fuel swirler (swirler) 17 having a role to guide the reciprocating motion of the valve body 3 and swirl the fuel is disposed on the upper surface of the nozzle bottom. The swirler 17 is provided with a plurality of flow paths 17a eccentric with respect to the center of the valve body 3 so that fuel flowing out of the flow path 17a onto the valve seat 2 flows while swirling along the valve seat. It is.

When the electromagnetic coil 12 is energized, the plunger 16 forms a magnetic circuit together with the yoke 14 and the core 13, and when the electromagnetic coil 12 is energized (excited), the plunger 16 moves by a predetermined stroke against the force of the spring 18. By this suction operation, the valve body 3 is separated from the valve seat 2 and opened, and the fuel is atomized while being swirled by the swirler 17 and injected from the fuel injection hole 4. This type of fuel injection valve has the feature of turning fuel with sufficient energy to improve the atomization of fuel, and has been evaluated as one that enables atomization of fuel, low fuel consumption, and stable idle operation.

Here, the configuration of the nozzle 1 and the valve seat 2 will be described in detail with reference to FIG.

The nozzle 1 is made of, for example, martensitic stainless steel. A valve seat 2 is provided at the center of the bottom upper surface of the nozzle 1. The valve seat 2 has a conical surface 2e on the part that comes into contact with the valve body 3 and on the upstream side of the contact part, and further has a radius of curvature smaller than that of the valve body 3 on the part that is downstream of the contact part and adjacent to the conical surface 2e. A small spherical concave surface 2f is formed, and the spherical concave surface 2f and the fuel injection hole 4 are connected to each other via a radius (R _B ).

According to the valve seat structure as described above, due to the presence of the spherical concave surface 2f having a smaller radius of curvature than the valve body 3, the downstream space S1 immediately below the valve body 3 can be formed as shown in FIG. S1 <S2 compared to the downstream space S2 immediately below the valve body of the valve seat 2a formed of one conical surface. As a result, FIGS. 2 and 3
(FIG. 2 is a conventional single conical valve seat, and FIG. 3 is a valve seat of the present embodiment) as shown in the flow chart of FIG. The embodiment can be smaller than the conventional one, and the variation of the fuel injection flow rate can be reduced.

In particular, in the fuel injection valve of the type in which the fuel is atomized by turning the fuel upstream of the valve seat 2 as in this embodiment, the fuel injection valve of the type turning the fuel downstream of the valve seat 2 is used. Since the swirling energy of the fuel is significantly increased as compared with the above, the generation of the vortex tends to increase. Therefore, it is extremely effective to use a valve seat capable of reducing the vortex generation region u as described above.

Further, the valve seat surface extends from the upstream side to the downstream side.
And a conical surface 2e and a spherical recess having a smaller radius of curvature than the valve body 3.
Between the surface 2f and the spherical concave surface 2f / fuel injection hole 4.
Since is smoothly formed by continuous surface between Lumpur surface R _B,
Fuel flow becomes smooth. As a result, as is apparent from the comparative explanatory views of FIGS. 2 and 3, in the case of the valve seat according to the present embodiment, the peeling phenomenon which has been remarkably caused in the past can be almost suppressed, and the spray state can be stabilized. Cavitation can be effectively prevented. When a swirling force is applied to the fuel upstream of the valve seat 2, if the separation phenomenon occurs, not only the cavitation but also the atomization of the fuel is adversely affected. It has a very large contribution as a function of the injection valve. Furthermore, spherical concave
Even if the surface 2f is provided, a conical surface 2e is secured upstream thereof.
Tangent line between the spherical valve element 3 and the conical surface 2e when the valve is closed.
The valve closing force urged by a spring or the like against the contact portion while securing the contact is
Concentrated structural benefits can be maintained.

The curvature of the spherical recess 2f in the valve seat 2 of the present embodiment the radius R _A and spherical recess 2f and connecting the fuel injection hole 4 R _B
FIG. 5 shows experimental data showing the effect of the above. Here R _A
= Spherical surface radius 1.02, R _B = radius 0.3,
These radiuses were recombined in various ways to show the variation of the fuel injection amount.

In the case of _{R A} = spherical radius 0, _{R B} = radius 0, namely when the valve seat shape shown in FIG. 9 (a), although variations is about 8%, _{R A} = spherical radius 1.02 ,
When R _B = R 0, the variation is about 4%. When R _A = Spherical radius 0, and when R _B = R 0.3, the variation is about 6%, and R _A = Spherical radius 1.
When 02, R _B = R 0.3, the variation is 1%
Becomes Thus, according to this example, it was confirmed that the variation was minimized to 1% from the above data.

The fuel injection amount of the fuel injection valve is determined by the minimum flow area of the flow path from the gap H between the valve element 3 and the valve seat 2 generated when the valve is opened to the fuel injection hole 4. It is determined. Since the above H has a large variation in manufacturing,
Normally, the fuel injection hole 4 has a minimum flow area. for that reason,
When setting the radius of curvature _RA of the spherical concave surface 2f, the spherical concave surface 2f
It is necessary to set the flow passage area in the space S1 formed by f so as not to be smaller than the flow passage area of the fuel injection hole 4.

FIG. 6 shows the area of the flow path from the flow path formed between the valve seat 2 and the valve element 3 of this embodiment to the outlet of the fuel injection hole 4 in a conventional example (single conical valve). Z). As is clear from this figure, the presence of the spherical concave surface 2f makes it possible to reduce the flow passage area downstream of the conical surface 2f while making it gentler than that of a single conical valve seat. It can be seen that the downstream space S1 is small, and has the effect of suppressing the generation of fuel vortex.

Next, a production example of the nozzle 1 with the valve seat 2 will be described.

FIG. 4 is a process chart showing a first manufacturing example.

First, as shown in FIG. 4 (a), as a nozzle material 1 ', a hardenable martensitic stainless steel is used, which is formed into a bottomed cylindrical shape by cold forging or the like.

Next, as shown in FIG. 4 (b), in the first pressing step, the above-mentioned conical surface 2e and spherical concave surface 2f are transfer-molded at the center of the upper surface of the bottom 1a 'of the nozzle material 1'. As shown in FIG. 4 (c), in a second pressing step, a blind hole 4 ′ to be a fluid injection hole 4 is formed at the center of the tip of the forming surface generated by the first pressing step.
As shown in (d), the corner between the spherical concave surface 2e and the blind hole 4 'is formed in a third pressing step (R _B ).

Next, as shown in FIG. 4 (e), the plastic flow portion extruded to the lower surface side of the bottom portion 1a 'by the series of pressing steps is cut. By this cutting, the fuel injection holes 4
The blind hole 4 'to be opened is opened, and the hole punching step is performed simultaneously with the above cutting step.

The manufacturing of the nozzle is completed through a process of hardening after the cutting.

As a press jig for forming a valve seat used in the above-described manufacturing process, a mold for transferring a valve seat at a tip end and a ceramic coating harder than the nozzle material 1 ′ such as TiN, TiC And a die made of a cemented carbide coated with TiAlN and a die having a plastic flow escape portion for receiving the punch.

[0045] Thus, according to the nozzle production method, the conical surface 2e which is an element of the valve seat 2, a spherical concave surface 2f, troublesome molding of R _B surface and the fuel injection hole 4 cutting, without requiring grinding operation The plastic working can be performed, the productivity of nozzle manufacturing can be increased, and the manufacturing cost can be reduced. In addition, since the plastic flow direction of the material when the valve seat 2 is transfer-molded is constant and uncomplicated, the amount of springback and residual stress after the molding are reduced, and as a result, a highly accurate nozzle with a valve seat can be provided. it can.

In the above production example, the blind hole 4 'was punched out by cutting the plastic flow portion at the same time.
The blind hole 4 'may be punched by press, laser processing or the like.

Next, a second example of manufacturing the nozzle with a valve seat in this embodiment will be described. FIG. 7 shows a sheet forming jig used in the second manufacturing example, and FIG. 8 shows a part of the manufacturing process.

As shown in FIG. 7, the sheet forming jig includes a punch 20, a die 23, an upper slide (a hydraulic pressurizing mechanism) 2
5, a guide 26 and the like.

The punch 20 is made of the same material as described in the first manufacturing example, and the mold portion 21 corresponds to the shape of the valve seat 2 shown in FIG. That is, as shown in FIG. 7 (b), the mold portion 21, via a radius (R _B ') to the subsequent central tip becomes projections 24 spherical bulge 21F' (this convex spherical valve body 3 to be used subject And the conical surface 21e 'is made continuous. The projection 24 is a blind hole 4 '(fuel injection hole 4), R _B' is the R _B,
The spherical convex surface 21f 'corresponds to the spherical concave surface 21f, and the conical surface 2e' corresponds to the conical surface 2e.

When a nozzle is formed by using such a pressing jig, first, as shown in FIG. 8A, a bottomed cylindrical shape having no hole in the processed portion (bottom portion) 1a 'is formed. While guiding the nozzle material 1 ′ by the guide 26, the die 2
Set on 3. Thereafter, the upper slide 25 is driven, and the punch 20 presses the bottom upper surface 1a 'of the nozzle material 1'. In this case, the punch 20 is guided along the inner periphery of the nozzle blank 1 '. Due to this pressurization, the processed part 1 a ′ of the nozzle material 1 ′ is extruded, plastic flow starts along the shape of the die 23, and the stopper part 22 of the punch 20
There it is pressurized until it hits the bottom upper surface of the nozzle material 1 ', a conical surface 2e which is an element of the blind hole 4' and the valve seat 2, spherical recess 2f, the R _B are transferred simultaneously molded. After molding, a blind hole 4 'is formed in the same manner as in the first production example.

Thus, according to this manufacturing example, it is possible to manufacture a highly accurate nozzle with a valve seat while improving productivity as in the first manufacturing example.

[0052]

As described above, according to the nozzle with the valve seat and the solenoid valve according to the present invention, by improving the shape of the valve seat, it is possible to suppress the variation in the fluid injection amount and the cavitation and improve the measurement accuracy. it can.

Further, according to the method for manufacturing a nozzle with a valve seat according to the present invention, the nozzle with a valve seat having excellent measurement accuracy as described above can be manufactured at low cost while improving productivity.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing details of a nozzle with a valve seat according to an embodiment of the present invention, and a longitudinal sectional view of an electromagnetic valve (fuel injection valve).

FIG. 2 is a fluid diagram at the time of valve opening when a conventional single conical valve seat is used.

FIG. 3 is a fluid diagram at the time of valve opening when the valve seat of the above embodiment is used.

FIG. 4 is a process explanatory view showing a first production example of the nozzle with a valve seat according to the present invention.

[5] and the spherical concave radius of curvature R _A in valve seat, a graph showing the effect on the flow rate variation in the with and without rounded connecting the the spherical recess and the fuel injection holes (R _B).

FIG. 6 is a graph showing a comparison of the flow path area on the downstream side of the valve body between the embodiment and the conventional single conical valve seat.

FIG. 7 is a longitudinal sectional view showing a nozzle forming press jig used in the above embodiment, and an enlarged view showing a die forming portion at the tip of a punch used therefor.

FIG. 8 is a process explanatory view in the case where a nozzle is manufactured using the punch of FIG. 7;

FIG. 9 is an explanatory view showing an example of a conventional nozzle with a valve seat.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Nozzle, 1 '... Nozzle material, 1a' ... Bottom part, 2 ... Valve seat, 2e ... Conical surface, 2e '... Conical surface, 2f ... Spherical concave surface,
2F' ... spherical bulge, R _B, R _B '... Earl, 3 ... spherical valve body 4 ... fuel injection hole, 11 ... solenoid valve (fuel injection valve), 1
2: electromagnetic coil, 16: movable iron core (plunger), 17
... fuel swirler, 20 ... punch, 23 ... dice, 24 ... tip protrusion. .

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location F16K 31/06 305 0380-3K F16K 31/06 305M (72) Inventor Atsushi Koshisaka Katsuta-shi, Ibaraki 2477, Kashima-Yatsu, Oaza, Hitachi, Ltd. Inside Hitachi Automotive Engineering Co., Ltd. (72) Inventor Kenichi Gunji 2477, Kashima-Yatsu, Oji, Kata-shi, Katsuta, Ibaraki Pref. Inventor Teruo Takayama 2520 Kodai, Kata-shi, Ibaraki Pref.Hitachi, Ltd.Automotive Equipment Division (72) Inventor Tosumi Kawaguchi 2520 Oji Takaba, Katsuta-shi, Ibaraki Pref. Koharu (56) References JP-A-56-44450 (JP, A) , U)

Claims (10)

(57) [Claims] 1. A conical valve seat which comes into contact with and separates from a spherical valve body by axial reciprocating motion of the spherical valve body, and a fluid injection hole is formed downstream of the valve seat and continuously with the valve seat surface. In the nozzle with a valve seat, the portion of the valve seat surface that contacts at least the valve body and the upstream side of the contact portion are conical surfaces, and the portion that is adjacent to the conical surface downstream of the contact portion is the conical surface. A nozzle with a valve seat, wherein the spherical concave surface has a radius of curvature smaller than that of the valve body, and the spherical concave surface and the fluid injection hole are connected via a round surface. 2. The nozzle with a valve seat according to claim 1, wherein the spherical concave surface has a larger radius of curvature than the radius surface. 3. A valve having a spherical valve body with a movable iron core which reciprocates in an axial direction by exciting and demagnetizing an electromagnetic coil inside a body of the solenoid valve, and having a valve seat corresponding to the valve body. At least a portion of the valve seat surface formed in the nozzle that comes into contact with the valve body and a portion upstream of the contact portion are conical surfaces, and a portion adjacent to the conical surface downstream of the contact portion is the valve. An electromagnetic valve, wherein a spherical concave surface having a smaller radius of curvature than a body is provided, and the spherical concave surface and the fluid ejection hole are connected via a round surface. 4. The fuel injection valve according to claim 3, wherein the solenoid valve is used as a fuel injection valve, and imparts a turning force to the fuel at a position upstream of a valve seat in a part of a fuel passage inside the solenoid valve body. An electromagnetic valve having a fuel swirler disposed therein. 5. A spherical valve element reciprocating in an axial direction and abutting on the spherical valve element.
When manufacturing a nozzle having a valve seat that is separated and a fluid injection hole located downstream of the valve seat, a bottomed cylindrical body that is to be a nozzle material is formed of a metal material, and the bottom of the bottomed cylindrical body is formed. At the center of the upper surface, at least a portion that contacts the valve body in the first pressing step and a portion that is upstream of the contact portion has a conical surface, and a portion that is adjacent to the conical surface downstream of the contact portion is smaller than the valve body. Forming a valve seat surface having a spherical concave surface with a small radius of curvature, forming a blind hole to be a fluid injection hole at the center of the tip of the forming surface generated by the first pressing step in a second pressing step, In the pressing step, the corner between the spherical concave surface and the blind hole is rounded, and the plastic pressed out to the bottom lower surface side of the bottomed cylindrical body by punching out the blind hole and the series of pressing steps. The nozzle is manufactured through the process of cutting the flowing part. The valve seat-method of manufacturing a nozzle, characterized in that. 6. A spherical valve body which reciprocates in an axial direction and abuts on the spherical valve body.
When manufacturing a nozzle having a valve seat that is separated and a fluid injection hole formed continuously with the valve seat surface on the downstream side of the valve seat,
Forming a bottomed cylinder to be a nozzle material with metal material,
In the center of the bottom upper surface of the bottomed cylindrical body, at least a portion that comes into contact with the valve body in the first pressing step and a valve seat surface having a conical surface on the upstream side from the contacting part are formed, and in the second pressing step, A portion of the valve seat surface adjacent to the conical surface downstream of the contact portion forms a spherical concave surface having a smaller radius of curvature than the valve body, and the first pressing is performed in a third pressing step. Forming a blind hole to be a fluid injection hole at the center of the tip of the forming surface generated by the step, and forming a corner between the spherical concave surface and the blind hole in a fourth pressing step,
And manufacturing the nozzle through a process of cutting the plastic flow portion extruded to the bottom lower surface side of the bottomed cylindrical body by the punching of the blind hole and the series of pressing processes, wherein the nozzle is manufactured. Method. 7. The step of cutting the plastic flow portion extruded to the bottom lower surface side of the bottomed cylindrical body by the series of pressing steps according to claim 5 or 6 , wherein the cutting simultaneously forms the injection hole with the injection hole. A method for manufacturing a nozzle with a valve seat, wherein a blind hole to be formed is set to be opened, and the cutting step is set to also serve as the hole punching step. 8. A jig for forming a bottomed cylindrical body to be a nozzle material from a metal material, and as a jig for forming a valve seat, a projection is formed at the center of the tip, and thereafter a spherical convex surface is formed via a radius. A punch having a curvature radius smaller than that of the target spherical valve element) and a continuous conical surface. The punch is guided along the inner periphery of the nozzle material while the bottom of the nozzle is guided by the punch. A method for manufacturing a nozzle with a valve seat, comprising press-pressing a center of an upper surface of the nozzle to transfer-mold a valve seat and a fluid injection hole by plastic flow by pressing. 9. The method according to claim 8, wherein after the center of the upper surface of the nozzle bottom is transfer-molded by the punch, a plastic flow portion extruded toward the lower surface of the nozzle bottom by the transfer molding is deleted. A method for manufacturing a nozzle with a valve seat, wherein a transfer portion of a tip projection is set to open as a fluid ejection hole. 10. The method according to claim 5, wherein:
Item, as a pressing jig used for forming the valve seat, a punch made of a cemented carbide having a die for transferring the valve seat at the tip and having a ceramic coating harder than the nozzle material on the die surface. A method for producing a nozzle with a valve seat, characterized by using: