CN109923300B

CN109923300B - Fuel injection valve and method for regulating injection flow

Info

Publication number: CN109923300B
Application number: CN201680090466.2A
Authority: CN
Inventors: 川崎翔太; 宗实毅; 伊藤启祐
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2016-11-09
Filing date: 2016-11-09
Publication date: 2021-02-26
Anticipated expiration: 2036-11-09
Also published as: CN109923300A; WO2018087827A1; JP6644164B2; JPWO2018087827A1

Abstract

The invention provides a fuel injection valve and a method for adjusting injection flow, which can reduce the manufacturing cost by sharing the groove shape according to different injection flow patterns, and can inhibit the generation of dead volume of fuel, thereby promoting the atomization of fuel spray from the initial injection stage. In the fuel injection valve of the present invention, the plurality of swirl chambers formed on the upper surface of the injection hole plate are constituted by a first swirl chamber and a second swirl chamber, wherein a swirl portion of the first swirl chamber communicates with a valve seat opening portion via a fuel introduction portion, the swirl portion of the second swirl chamber does not communicate with the valve seat opening portion, and an injection hole for injecting fuel is formed in the swirl portion of the first swirl chamber.

Description

Fuel injection valve and method for regulating injection flow

Technical Field

The present invention relates to a fuel injection valve for supplying fuel to an internal combustion engine of an automobile or the like and a method for adjusting an injection flow rate, and particularly relates to a fuel injection valve capable of promoting atomization in spray characteristics.

Background

In recent years, in the process of strengthening the restriction of exhaust gas from an internal combustion engine of an automobile or the like, atomization of fuel spray injected from a fuel injection valve is required.

For example, patent document 1 discloses a conventional fuel injection valve including: a valve housing formed symmetrically about a longitudinal axis, wherein a central opening is provided downstream of the valve seat surface, at least two tangential direction passages extend radially outward from the central opening, each tangential direction passage opens in a tangential direction to each swirl chamber, and a fixed amount opening for fuel leads outward from the center of the swirl chamber; and a valve closing member that is disposed within the valve housing and cooperates with the valve seat surface.

In the conventional fuel injection valve of patent document 1, the fuel rectified and accelerated flows into the swirl chamber through the tangential direction passage, forms a swirling flow in the swirl chamber, and is injected from the injection hole while swirling in the injection hole. The fuel injected from the injection hole is diffused in a hollow conical shape in a thin liquid film state by the edge portion of the opening portion of the injection hole, thereby promoting atomization of the fuel.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. Hei 1-271656

Disclosure of Invention

Technical problem to be solved by the invention

However, in the conventional fuel injection valve of patent document 1, since the swirling flow of the fuel atomizes the fuel, it is necessary to design not only the size of the injection hole but also the size, number, arrangement, and the like of the swirl chamber, that is, the groove shape, in accordance with the assumed flow rate and the diffusion angle of the spray. Thus, there are the following technical problems: the slot shape needs to be changed for each different pattern of jet flow, so that a reduction in manufacturing cost cannot be achieved.

On the other hand, it is conceivable to change the ejection flow rate by changing the diameter of the ejection holes and the number of the ejection holes without changing the groove shape. However, when the diameter of the nozzle hole is changed, not only the ejection flow rate but also the spray spread angle changes. The following technical problems exist: when the spray spread angle is large, the fuel adheres to the wall surface of the intake port, thereby deteriorating controllability of the engine, and when the spray spread angle is small, the liquid film of the injected fuel becomes thick, and atomization becomes poor.

On the other hand, when a plurality of swirl chambers are provided in advance and the number of the nozzle holes is changed by forming the nozzle holes in the swirl chambers corresponding to the required ejection flow rate, the ejection flow rate can be changed without changing the spread angle of the spray. However, since there is a swirl chamber in which no injection hole is formed, that is, a swirl chamber not used for injection, fuel enters the swirl chamber not used for injection. The volume portion of the swirl chamber not used for the above injection forms the dead volume of the fuel. The following technical problems exist: when the dead volume of the fuel becomes large, the fuel that has been rectified and insufficiently accelerated is injected immediately after the start of injection, and atomization of the fuel spray at the initial stage of injection is deteriorated.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fuel injection valve and a method of adjusting an injection flow rate, which can reduce manufacturing cost by sharing a groove shape with respect to patterns of different injection flow rates, and can promote atomization of fuel spray from an initial stage of injection by suppressing generation of a dead volume of fuel.

Technical scheme for solving technical problem

The fuel injection valve of the present invention includes: a valve seat having a truncated conical seat surface and a cylindrical seat opening portion, the seat surface being reduced in diameter toward a downstream side, the seat opening portion being formed on the downstream side of the seat surface coaxially with the seat surface, the seat surface of the valve seat and an axis of the opening portion being set as a central axis; a valve member seated on the seating surface to block the fuel from flowing out of the opening portion, the valve member being separated from the seating surface to allow the fuel to flow out of the opening portion; and an orifice plate disposed downstream of the valve seat such that a flat upper surface faces upstream, wherein a plurality of swirl chambers are formed in the upper surface of the orifice plate, each of the plurality of swirl chambers includes a swirl portion that applies a swirl force to the fuel and a fuel introduction portion that introduces the fuel into the swirl portion, and the plurality of swirl chambers include a first swirl chamber and a second swirl chamber, wherein the swirl portion of the first swirl chamber communicates with the valve seat opening portion via the fuel introduction portion, the swirl portion of the second swirl chamber does not communicate with the valve seat opening portion, and an injection hole for injecting the fuel is formed in the swirl portion of the first swirl chamber.

Effects of the invention

In the present invention, the plurality of swirl chambers include: a first swirl chamber in which the swirl portion communicates with the valve seat opening portion via the fuel introduction portion; and a second swirl chamber in which the swirl portion does not communicate with the valve seat opening portion, wherein a nozzle hole is formed in the swirl portion of the first swirl chamber. Thus, for example, the number of the first swirl chambers, that is, the number of the injection holes can be adjusted by changing the diameter of the valve seat opening, so that the groove shape can be shared for different patterns of the injection flow rate, and the manufacturing cost can be reduced.

Further, since the swirl portion of the second swirl chamber which does not contribute to injection does not communicate with the valve seat opening portion, the fuel does not enter the second swirl chamber. As a result, the dead volume of the fuel is reduced, and therefore, the fuel that has been sufficiently homogenized and accelerated is injected immediately after the start of injection, thereby promoting atomization of the fuel spray at the initial stage of injection.

Drawings

Fig. 1 is a vertical sectional view illustrating the structure of a fuel injection valve according to embodiment 1 of the present invention.

Fig. 2 is a view showing the periphery of a valve seat of a fuel injection valve according to embodiment 1 of the present invention.

Fig. 3 is a diagram illustrating a fuel flow in a swirl chamber of a fuel injection valve according to embodiment 1 of the present invention.

Fig. 4 is a sectional view showing a mode of increasing the injection flow rate of the fuel injection valve according to embodiment 1 of the present invention.

Fig. 5 is a view showing the periphery of the valve seat of the fuel injection valve according to embodiment 2 of the present invention.

Fig. 6 is a view showing the periphery of the valve seat of the fuel injection valve according to embodiment 3 of the present invention.

Fig. 7 is a view showing the periphery of the valve seat of the fuel injection valve according to embodiment 4 of the present invention.

Fig. 8 is a view showing the periphery of the valve seat of the fuel injection valve according to embodiment 5 of the present invention.

Fig. 9 is a view showing the periphery of the valve seat of the fuel injection valve according to embodiment 6 of the present invention.

Fig. 10 is a view showing the periphery of the valve seat of the fuel injection valve according to embodiment 7 of the present invention.

Fig. 11 is a view showing the periphery of the valve seat in the case of a small injection flow rate in the fuel injection valve according to embodiment 8 of the present invention.

Fig. 12 is a view showing the periphery of the valve seat in the case of a large injection flow rate in the fuel injection valve according to embodiment 8 of the present invention.

Detailed Description

Embodiment mode 1

Fig. 1 is a vertical sectional view illustrating a structure of a fuel injection valve according to embodiment 1 of the present invention, fig. 2 is a view showing a periphery of a valve seat of the fuel injection valve according to embodiment 1 of the present invention, fig. 2 (a) is a vertical sectional view, and fig. 2 (b) is a sectional view taken along a-a of fig. 2 (a). Fig. 3 is a diagram illustrating a fuel flow in a swirl chamber of a fuel injection valve according to embodiment 1 of the present invention, and fig. 4 is a sectional view showing a mode of increasing an injection flow rate of the fuel injection valve according to embodiment 1 of the present invention. Fig. 4 is a sectional view of a position corresponding to fig. 2 (b). The vertical cross-sectional view is a cross-sectional view of a plane including the central axis a0 of the fuel injection valve.

In fig. 1 and 2, the fuel injection valve 100 includes a valve device, a solenoid device that generates electromagnetic force that opens the valve device, and a spring 8 that generates urging force that closes the valve device.

A solenoid device is made of a magnetic metal material into a cylindrical shape, and includes: a core body 1, the core body 1 serving as a fixed core portion of a magnetic circuit; a coil 2 wound around a bobbin 3 made of insulating resin, the coil 2 being disposed so as to surround one end of the core 1; a yoke 4, the yoke 4 being made of a magnetic metal material and serving as a yoke portion of the magnetic circuit; and an armature 7, the armature 7 serving as a movable iron core portion of the magnetic circuit. The core 1, the coil 2, and the yoke 4 are integrally formed by a case 5 made of insulating resin. Further, a terminal 6 for supplying power to the coil 2 is integrally formed with the case 5.

Further, a spring 8 is disposed inside the core body 1, and a rod 9 is fixed inside the core body 1 so as to be able to adjust the urging force of the spring 8.

The valve device includes a valve body 10, a valve element 11, a valve seat 12, and the like. The valve body 10 is made of a magnetic metal material into a cylindrical shape, and is welded to the core 1 in a state of being pressed into an outer peripheral portion of one end of the core 1. The valve body 11 is welded to the armature 7 in a state of being pressed into the armature 7, and is attached so as to protrude from the armature 7 to one end side. The armature 7 is disposed in the valve main body 10 so as to face one end surface of the core 1 and be movable in a direction parallel to the central axis a0 of the fuel injection valve 100. A ball 15 as a valve member is fixed to one end of the valve body 11 and is disposed inside one end side of the valve body 10. The valve seat 12 is fixed inside one end portion of the valve main body 10. The flat plate-like orifice plate 13 is fixed to one end surface of the valve seat 12 by a welding portion 16 with its flat upper surface facing the valve seat 12.

The guide portion 10a is formed to bulge the other end side of the inner circumferential surface of the valve body 10. The armature 7 is disposed inside the valve body 10 so as to be slidable on the inner peripheral surface of the guide portion 10 a. The other end of the valve body 11 abuts against the spring 8 to receive the urging force of the spring 8. The valve seat 12 includes: a seat surface 12a having a truncated conical shape, one end side of the seat surface 12a being tapered; a cylindrical valve seat opening 12b formed at one end of the seat surface 12a in the valve seat opening 12 b; and a cylindrical sliding surface 12c, the sliding surface 12c being formed on the other end side of the seat surface 12 a. The center axes of the seat surface 12a, the seat opening 12b, and the sliding surface 12c coincide with the center axis a 0. The chamfered portion 15a is formed on the outer peripheral surface of the ball 15, and the outer peripheral portion of the ball 15 is substantially pentagonal. Moreover, the pentagonal corner of the ball 15 is guided by the sliding surface 12c to move in a direction parallel to the central axis a0, and the ball 15 can be separated from the seat surface 12a or can be seated on the seat surface 12 a.

A first swirl chamber 17a and a second swirl chamber 17b are formed in the orifice plate 13 so as to be recessed in the upper surface. The first swirling chamber 17a and the second swirling chamber 17b are respectively constituted by a swirling portion 18 and a fuel introducing portion 19, wherein the swirling portion 18 is formed in a cylindrical shape and imparts a swirling force to the fuel, and the fuel introducing portion 19 is formed linearly with a predetermined width, is connected in a tangential direction of the swirling portion 18, and introduces the fuel into the swirling portion 18. Here, the first swirl chamber 17a and the second swirl chamber 17b are disposed so as to sandwich the center axis a0 such that the fuel introduction portion 19 faces the center axis a0 and the longitudinal direction of the fuel introduction portion 19 coincides with the radial direction centered on the center axis a 0. The fuel introducing portion 19 of the first swirl chamber 17a enters the valve seat opening portion 12b when viewed from the direction of the center axis a 0. The injection holes 14 are formed in the swirl portion 18 of the first swirl chamber 17a so as to penetrate the injection hole plate 13 in the plate thickness direction. The fuel introduction portion 19 of the second swirl chamber 17b is located outside the valve seat opening portion 12b when viewed from the direction of the center axis a 0. Further, the nozzle hole 14 is not formed in the swirl portion 18 of the second swirl chamber 17 b.

Thus, the groove shape formed on the upper surface of the nozzle plate 13 is the following shape: the first swirl chamber 17a and the second swirl chamber 17b are disposed so as to sandwich the center axis a0, and the longitudinal direction of the fuel introduction portion 19 is aligned with the radial direction about the center axis a0, and the distance from the center axis a0 to the fuel introduction portion 19 is made different. Further, the swirl portion 18 of the first swirl chamber 17a and the second swirl chamber 17b is located outside the valve seat opening portion 12b as viewed from the direction of the center axis a0, so that the fuel is introduced only through the fuel introduction portion 19.

Next, the operation of the fuel injection valve 100 configured as described above will be described.

In the initial state, the coil 2 is not energized, the valve body 11 is pressed toward the valve seat 12 by the biasing force of the spring 8, and the ball 15 abuts against the seat surface 12a of the valve seat 12, thereby being in the valve closed state. Further, the armature 7 is separated from the core 1. Further, the fuel is supplied to the fuel injection valve 100 from the other end side of the center axis a 0.

When an operation signal is transmitted to a drive circuit of the fuel injection valve 100 by an engine control device, the coil 2 of the fuel injection valve 100 is energized from the outside via the terminal 6. This generates a magnetic flux in a magnetic circuit including the armature 7, the core 1, the yoke 4, and the valve body 10. Next, a magnetic attractive force attracting the armature 7 to the core 1 is generated. Then, the armature 7 slides on the inner peripheral surface of the guide portion 10a to move toward the core 1 side against the urging force of the spring 8, thereby coming into surface contact with one end surface of the core 1. The ball 15 coupled to the armature 7 via the valve element 11 is separated from the seat surface 12a of the valve seat 12, and thus the valve is opened.

Therefore, the fuel supplied to the fuel injection valve 100 flows through the inside of the core 1 toward the ball 15 side. Then, the fuel passes between the chamfered portion 15a of the ball 15 and the sliding surface 12c, and passes between the ball 15 and the seat surface 12 to flow into the valve seat opening portion 12 b. The fuel flowing into the valve seat opening portion 12b passes through the fuel introduction portion 19 entering the interior of the valve seat opening portion 12b as shown by the arrow in fig. 3, and flows into the swirl portion 18 of the first swirl chamber 17a from the tangential direction. Thereby, the fuel swirls along the inner peripheral wall surface of the swirling portion 18 of the first swirling chamber 17 a. Thus, at the swirl portion 18 of the first swirl chamber 17a, a swirl force is applied to the fuel. Then, the fuel to which the swirl force is applied is injected into the intake passage of the engine while swirling along the inner peripheral wall surface of the injection hole 14. At this time, the fuel injected from the injection hole 14 is diffused in a hollow conical shape in a thin liquid film state by the edge portion of the opening portion of the injection hole 14, thereby promoting atomization of the fuel.

Next, when an operation stop signal is transmitted to the drive circuit of the fuel injection valve 100 by the engine control device, the energization of the coil 2 is stopped. This eliminates the magnetic attraction force attracting the armature 7 to the core 1 side. Then, the armature 7 slides on the inner peripheral surface of the guide portion 10a, and moves toward the valve seat 12 side by the urging force of the spring 8. Then, the ball 15 comes into contact with the seat surface 12a in a state of being pressed by the biasing force of the spring 8 to be in a valve-closed state, and the fuel injection is stopped.

In embodiment 1, the first swirl chamber 17a and the second swirl chamber 17b are formed in the injection hole plate 13, and only the fuel introduction portion 19 of the first swirl chamber 17a in which the injection holes 14 are formed enters the inside of the valve seat opening portion 12 b. Therefore, as shown in fig. 4, the diameter of the valve seat opening 12b is increased, and the fuel introducing portion 19 of the second swirl chamber 17b is inserted into the valve seat opening 12 b. Thereby, the second swirl chamber 17b becomes the first swirl chamber 17 a. Further, the number of the first swirl chambers 17a communicating with the valve seat opening 12b, that is, the number of the injection holes 14 can be changed by performing post-processing on the injection holes 14 in the swirl portion 18 of the changed second swirl chamber 17 b. Further, each convolution 18 is located outside the valve seat opening 12 b.

When the second swirl chamber 17b not used for injection enters the inside of the valve seat opening portion 12b, the fuel flows until the second swirl chamber 17b not used for injection. Thus, the volume portion of the second swirl chamber 17b not used for injection forms the dead volume of the fuel. According to embodiment 1, the second swirl chamber 17b not used for injection does not enter the valve seat opening portion 12b, and therefore the dead volume of the fuel can be reduced. As a result, the dead volume of the fuel is reduced, and therefore, the fuel after the acceleration by the reforming is injected immediately after the start of the injection. Therefore, fuel injection with good atomization can be achieved from the initial stage of injection.

Here, in embodiment 1, the case where the number of swirl chambers is two, i.e., the first swirl chamber 17a and the second swirl chamber 17b, is shown, but the number of swirl chambers may be appropriately set according to the required fuel injection amount. Therefore, it is possible to cope with various fuel injection amounts by designing the groove shape only by assuming the required maximum fuel injection amount, using the designed single groove shape, changing the diameter of the valve seat opening portion 12b, and performing the post-machining on the injection hole 14. Thus, the groove shape can be shared for the patterns requiring different fuel injection amounts, and therefore, the manufacturing cost can be reduced.

Further, the strength of the injection hole plate 13 may be reduced and the injection hole plate 13 may be deformed due to long-term use of the fuel injection valve 100. When the injection hole plate 13 is deformed, a gap is generated between the injection hole plate 13 and the valve seat 12, and the fuel flows into the second swirl chamber 17b from the gap. In embodiment 1, since the injection hole 14 is not formed in the second swirl chamber 17b, the fuel that flows into the second swirl chamber 17b from the gap does not flow out to the outside. Thus, even if the orifice plate 13 is deformed, since the outflow of the fuel is prevented, the injection flow rate is not changed, and the injection flow rate is stabilized.

Embodiment mode 2

Fig. 5 is a view showing the periphery of a valve seat of a fuel injection valve according to embodiment 2 of the present invention, fig. 5 (a) is a vertical sectional view, and fig. 5 (B) is a sectional view taken along line B-B of fig. 5 (a).

In fig. 5, the first swirl chamber 17a and the second swirl chamber 17b are disposed so as to sandwich the center axis a0 such that the fuel introduction portion 19 faces the center axis a0 and the longitudinal direction of the fuel introduction portion 19 coincides with the radial direction centered on the center axis a 0. The fuel introducing portion 19 of the first swirl chamber 17a enters the valve seat opening portion 12b when viewed from the direction of the center axis a 0. The fuel introduction portion 19 of the second swirl chamber 17b is located outside the valve seat opening portion 12b when viewed from the direction of the center axis a 0. Further, the nozzle hole 14 is formed in the swirl portion 18 of the first swirl chamber 17a and the second swirl chamber 17 b.

The other structure is configured in the same manner as in embodiment 1.

The groove shape formed on the upper surface of the injection hole plate 13 of embodiment 2 includes a first swirl chamber 17a and a second swirl chamber 17b each having a swirl portion 18 and a fuel introduction portion 19. The first swirl chamber 17a and the second swirl chamber 17b are disposed so as to sandwich the center axis a0, and the longitudinal direction of the fuel introduction portion 19 is aligned with the radial direction about the center axis a0, and the distance from the center axis a0 to the fuel introduction portion 19 is made different. The injection hole 14 is formed in the swirl portion 18 of each of the first swirl chamber 17a and the second swirl chamber 17 b. Only the fuel introduction portion 19 of the first swirl chamber 17a enters the inside of the valve seat opening portion 12 b. Thus, the fuel does not flow into the second swirl chamber 17b not used for injection. Further, the number of the first swirl chambers 17a communicating with the valve seat opening 12b, that is, the number of the injection holes 14 can be changed by increasing the diameter of the valve seat opening 12b to allow the fuel introducing portions 19 of the first swirl chamber 17a and the second swirl chamber 17b to enter the valve seat opening 12 b.

Therefore, also in embodiment 2, the same effects as those in embodiment 1 can be obtained.

According to embodiment 2, the injection hole 14 is formed in the swirl portion 18 of the first swirl chamber 17a and the second swirl chamber 17b in advance. Therefore, when changing the injection flow rate, the number of the first swirl chambers 17a communicating with the valve seat opening 12b, that is, the number of the injection holes 14 can be changed by simply increasing the diameter of the valve seat opening 12b to allow the fuel introduction portions 19 of the first swirl chamber 17a and the second swirl chamber 17b to enter the valve seat opening 12 b. That is, the subsequent processing of the nozzle hole 14 is not required. Thus, not only the groove shape but also the orifice plate 13 can be shared for the patterns requiring different fuel injection amounts, and the manufacturing cost can be further reduced.

Embodiment 3

Fig. 6 is a view showing the periphery of a valve seat of a fuel injection valve according to embodiment 3 of the present invention, wherein fig. 6 (a) is a vertical sectional view, and fig. 6 (b) is a sectional view taken along line C-C of fig. 6 (a).

In fig. 6, two first swirl chambers 17a and two second swirl chambers 17b are arranged at equal angular intervals around a central axis a0, respectively, so that the fuel introduction portion 19 faces the central axis a0 and the longitudinal direction of the fuel introduction portion 19 coincides with the radial direction around the central axis a 0. A distance between the pair of first swirl chambers 17a disposed to face each other with the center axis a0 therebetween and the center axis a0 is L1. A distance between the pair of second swirl chambers 17b disposed to face each other with the center axis a0 therebetween and the center axis a0 is L2. Here, the distances L1 and L2 have a relationship of L1 < R1 < L2 with the radius R1 of the valve seat opening 12 b. That is, the fuel introduction portions 19 of the paired first swirl chambers 17a enter the inside of the valve seat opening portion 12b when viewed from the direction of the center axis a 0. The fuel introduction portions 19 of the paired second swirl chambers 17b are located outside the valve seat opening portion 12b when viewed from the direction of the center axis a 0. Further, the injection holes 14 are formed only in the swirl portions 18 of the paired first swirl chambers 17 a.

The other structure is configured in the same manner as in embodiment 1.

The groove shape formed on the upper surface of the injection hole plate 13 of embodiment 3 includes two first swirl chambers 17a and two second swirl chambers 17b each formed of a swirl portion 18 and a fuel introduction portion 19. The four first swirl chambers 17a and the four second swirl chambers 17b are arranged at equal angular intervals around the center axis a0 such that the longitudinal direction of the fuel introduction portion 19 coincides with the radial direction around the center axis a 0. A distance between the pair of first swirl chambers 17a opposing to each other across the center axis a0 and the center axis a0 is L1, and a distance between the pair of second swirl chambers 17b opposing to each other across the center axis a0 and the center axis a0 is L2 which is larger than L1. Only the fuel introduction portions 19 of the paired first swirl chambers 17a enter the valve seat opening portion 12 b. Further, the injection holes 14 are formed only in the swirl portions 18 of the paired first swirl chambers 17 a. Thereby, the fuel does not flow into the second swirl chamber 17b not used for injection. Further, the number of the first swirl chambers 17a communicating with the valve seat opening 12b, that is, the number of the injection holes 14 can be changed by enlarging the diameter of the valve seat opening 12b to allow the fuel introduction portions 19 of the two second swirl chambers 17b to enter the valve seat opening 12b and then performing post-processing on the injection holes 14.

Therefore, also in embodiment 3, the same effects as those in embodiment 1 can be obtained.

Here, in embodiment 3, the four first swirling chambers 17a and the four second swirling chambers 17b may be provided in groove shapes having different distances from the central axis a 0. In this case, the number of the injection holes 14 can be changed to one, two, three, and four by changing the diameter of the valve seat opening 12b with a single groove shape and performing subsequent processing on the injection holes 14. Thus, four patterns of different jet flows can be handled by a single groove shape. Further, the injection holes 14 may be formed in the four first swirl chambers 17a and the four second swirl chambers 17b in advance. Thus, four patterns of different jet flow rates can be handled by a single jet hole plate 13.

Embodiment 4

Fig. 7 is a view showing the periphery of a valve seat of a fuel injection valve according to embodiment 4 of the present invention, wherein fig. 7 (a) is a vertical sectional view, and fig. 7 (b) is a D-D sectional view of fig. 7 (a).

In fig. 7, the first swirl chamber 20 is constituted by a fuel introduction portion 21 formed linearly with a predetermined width, connected in the tangential direction of each swirl portion 18 through a central axis a0, and a pair of swirl portions 18 for introducing fuel into each swirl portion 18. The first swirl chambers 20 are disposed such that centers of the pair of swirlers 18 are point-symmetric about the central axis a 0. Two second swirl chambers 17b are disposed so as to sandwich the center axis a0, so that the fuel introduction portion 19 is directed toward the center axis a0, the longitudinal direction of the fuel introduction portion 19 is aligned with the radial direction around the center axis a0, and the distance from the center axis a0 to the fuel introduction portion is made equal. The longitudinal direction of the fuel introduction portion 19 of the second swirl chamber 17b is orthogonal to the longitudinal direction of the fuel introduction portion 21 of the first swirl chamber 20. The distance between the second swirl chamber 17b and the center axis a0 is L2 larger than the radius R1 of the valve seat opening 12 b. That is, the fuel introducing portion 19 of the second swirl chamber 17b does not enter the valve seat opening portion 12b when viewed from the direction of the center axis a 0. Further, the injection hole 14 is formed only in the swirl portion 18 of the first swirl chamber 20.

The other structure is configured in the same manner as in embodiment 1.

The groove shape formed on the upper surface of the nozzle plate 13 of embodiment 4 includes: one first swirl chamber 20 in which the two swirl portions 18 communicate with each other through a fuel introduction portion 21; and two second swirl chambers 17b each composed of a swirl portion 18 and a fuel introduction portion 19. The first swirl chamber 20 is disposed such that the two swirl portions 18 are point-symmetrical about the central axis a 0. The two second swirl chambers 17b are disposed so as to sandwich the center axis a0, and the longitudinal direction of the fuel introduction portion 19 is aligned with the radial direction around the center axis a0, and the longitudinal direction of the fuel introduction portion 19 is orthogonal to the longitudinal direction of the fuel introduction portion 21. Further, the distance between the two second swirl chambers 17b and the central axis a0 is L2 larger than the radius R1 of the valve seat opening portion 12 b. The nozzle hole 14 is formed only in the swirl portion 18 of the first swirl chamber 20. Thereby, the fuel does not flow into the second swirl chamber 17b not used for injection. Further, the number of the first swirl chambers 20 and the first swirl chambers 17a communicating with the valve seat opening 12b, that is, the number of the injection holes 14 can be changed by enlarging the diameter of the valve seat opening 12b so that the fuel introduction portions 19 of the two second swirl chambers 17b enter the valve seat opening 12b and performing post-processing on the injection holes 14.

Therefore, also in embodiment 4, the same effects as those in embodiment 1 can be obtained.

Here, in embodiment 4, the two second swirl chambers 17b may have groove shapes having different distances from the central axis a 0. In this case, the number of the injection holes 14 can be changed to two, three, and four by changing the diameter of the valve seat opening 12b with a single groove shape and performing subsequent processing on the injection holes 14. Thus, three types of different jet flows can be handled by a single groove shape. Further, the injection holes 14 may be formed in the first swirl chamber 20 and the second swirl chamber 17b in advance. Thus, three types of different jet flow rates can be handled by the single jet hole plate 13.

In embodiment 4, the center of the turning portion 18 of the first turning chamber 20 is disposed so as to be point-symmetrical about the center axis a0, but the center of the turning portion 18 does not necessarily need to be point-symmetrical about the center axis a0, and may be disposed separately from the center axis a 0.

Embodiment 5

Fig. 8 is a view showing the periphery of a valve seat of a fuel injection valve according to embodiment 5 of the present invention, fig. 8 (a) is a vertical sectional view, and fig. 8 (b) is a sectional view taken along line E-E of fig. 8 (a).

In fig. 8, the diameter of the valve seat opening 12b increases, and the fuel introducing portions 19 of the first swirl chamber 17a and the second swirl chamber 17b enter the valve seat opening 12b at the same time. The intermediate plate 30 is disposed between the valve seat 12 and the nozzle plate 13. The valve seat 12, the intermediate plate 30, and the orifice plate 13 are integrally fixed to each other by a welding portion 16. In the intermediate plate 30, a cylindrical intermediate opening 30a having a diameter smaller than that of the valve seat opening 12b is formed coaxially with the valve seat opening 12 b. Further, when viewed from the direction of the center axis a0, only the fuel introduction portion 19 of the first swirl chamber 17a is located inside the intermediate opening portion 30 a. The nozzle hole 14 is formed only in the swirl portion 18 of the first swirl chamber 17 a.

The other structure is configured in the same manner as in embodiment 1.

The groove shape formed on the upper surface of the injection hole plate 13 of embodiment 5 includes a first swirl chamber 17a and a second swirl chamber 17b each composed of a swirl portion 18 and a fuel introduction portion 19. The first swirl chamber 17a and the second swirl chamber 17b are disposed so as to face each other with the center axis a0 interposed therebetween, and the longitudinal direction of the fuel introduction portion 19 is aligned with the radial direction around the center axis a0, and the distance from the center axis a0 is made different. The diameter of the valve seat opening 12b increases, and the fuel introducing portions 19 of the first swirling chamber 17a and the second swirling chamber 17b enter the valve seat opening 12b at the same time. The intermediate plate 30 is disposed between the valve seat 12 and the injection hole plate 13, and only the fuel introduction portion 19 of the first swirl chamber 17a is located inside the intermediate opening 30a formed in the intermediate plate 30. The nozzle hole 14 is formed only in the swirl portion 18 of the first swirl chamber 17 a.

Thereby, the fuel does not flow into the second swirl chamber 17b not used for injection. Further, by removing the intermediate plate 30, the fuel introducing portion 19 of the second swirl chamber 17b is caused to enter the valve seat opening portion 12b, and the injection holes 14 are subsequently processed, whereby the number of the first swirl chambers 17a communicating with the valve seat opening portion 12b, that is, the number of the injection holes 14 can be changed.

Therefore, also in embodiment 5, the same effects as those in embodiment 1 can be obtained.

According to embodiment 5, the number of the injection holes 14 can be changed by merely removing the intermediate plate 30 and performing the subsequent processing on the injection holes 14, and therefore, cost reduction can be achieved without changing the valve seat 12.

Here, in embodiment 5, the injection holes 14 may be formed in the first swirl chamber 17a and the second swirl chamber 17b in advance. This allows a single nozzle plate 13 to cope with two different types of jet flow rates.

Embodiment 6

Fig. 9 is a view showing the periphery of a valve seat of a fuel injection valve according to embodiment 6 of the present invention, fig. 9 (a) is a vertical sectional view, and fig. 9 (b) is a sectional view taken along direction F-F of fig. 9 (a).

In fig. 9, the diameter of the valve seat opening 12b increases, and the fuel introducing portions 19 of the first swirl chamber 17a and the second swirl chamber 17b enter the valve seat opening 12b at the same time. The intermediate plate 30 is disposed between the valve seat 12 and the nozzle plate 13. The valve seat 12, the intermediate plate 30, and the orifice plate 13 are integrally fixed to each other by a welding portion 16. The intermediate plate 30 has an intermediate opening 30a coaxial with the valve seat opening 12 b. Further, when viewed from the direction of the center axis a0, only the fuel introduction portion 19 of the first swirl chamber 17a is located inside the intermediate opening portion 30 a. The nozzle hole 14 is formed only in the swirl portion 18 of the first swirl chamber 17 a.

Here, the radius R1 of the valve seat opening portion 12b, the radius R2 of the intermediate opening portion 30a, the distance L1 between the first swirl chamber 17a communicating with the intermediate opening portion 30 and the central axis a0, and the distance L2 between the second swirl chamber 17b not communicating with the intermediate opening portion 30a and the central axis a0 have a relationship of L1 < R2 < L2 < R1.

The other structure is configured in the same manner as in embodiment 3.

The groove shape formed on the upper surface of the injection hole plate 13 of embodiment 6 includes four first swirl chambers 17a and four second swirl chambers 17b each formed of a swirl portion 18 and a fuel introduction portion 19. The four first swirl chambers 17a and the four second swirl chambers 17b are arranged at equal angular intervals around the center axis a0 such that the longitudinal direction of the fuel introduction portion 19 coincides with the radial direction around the center axis a 0. A distance between the pair of first swirl chambers 17a opposing to each other across the center axis a0 and the center axis a0 is L1, and a distance between the pair of second swirl chambers 17b opposing to each other across the center axis a0 and the center axis a0 is L2 which is larger than L1.

The intermediate plate 30 is disposed between the valve seat 12 and the nozzle plate 13. The radius R1 of the valve seat opening 12b, the radius R2 of the intermediate opening 30a, the distance L1 between the first swirl chamber 17a communicating with the intermediate opening 30 and the central axis a0, and the distance L2 between the second swirl chamber 17b not communicating with the intermediate opening 30a and the central axis a0 have a relationship of L1 < R2 < L2 < R1. The injection hole 14 is formed only in the swirl portion 18 of the first swirl chamber 17a communicating with the intermediate opening 30 a.

Thereby, the fuel does not flow into the second swirl chamber 17b not used for injection. Further, by removing the intermediate plate 30, the fuel introducing portion 19 of the second swirl chamber 17b is caused to enter the valve seat opening portion 12b, and the injection holes 14 are subjected to post-processing, whereby the number of the first swirl chambers 17a communicating with the valve seat opening portion 12b, that is, the number of the injection holes 14 can be changed.

Therefore, also in embodiment 6, the same effects as those in embodiment 3 can be obtained.

According to embodiment 6, the number of the injection holes 14 can be changed by simply removing the intermediate plate 30 and performing subsequent processing on the injection holes 14, and therefore, cost reduction can be achieved without changing the valve seat 12.

Here, in embodiment 6, the first swirl chamber 17a and the second swirl chamber 17b may have groove shapes having different distances from the central axis a 0. In this case, the number of the injection holes 14 can be changed to one, two, three, and four simply by changing the diameter of the intermediate opening 30a with a single groove shape or removing the intermediate plate 30 and performing subsequent processing on the injection holes 14. Thus, four patterns of different jet flows can be handled by a single groove shape. Further, the injection holes 14 may be formed in the first swirl chamber 17 and the second swirl chamber 17b in advance. Thus, four patterns of different jet flow rates can be handled by a single jet hole plate 13.

Embodiment 7

Fig. 10 is a view showing the periphery of a valve seat of a fuel injection valve according to embodiment 7 of the present invention, fig. 10 (a) is a vertical sectional view, and fig. 10 (b) is a G-G sectional view of fig. 10 (a).

In fig. 10, the diameter of the valve seat opening 12b increases, and the

fuel introducing portions

19 and 21 of the first swirl chamber 20 and the second swirl chamber 17b enter the valve seat opening 12b at the same time. The intermediate plate 30 is disposed between the valve seat 12 and the nozzle plate 13. The valve seat 12, the intermediate plate 30, and the orifice plate 13 are integrally fixed to each other by a welding portion 16. The intermediate plate 30 has an intermediate opening 30a coaxial with the valve seat opening 12 b. Further, when viewed from the direction of the central axis a0, only the fuel introduction portion 21 of the first swirl chamber 20 is positioned inside the intermediate opening portion 30 a. The nozzle hole 14 is formed only in the swirl portion 18 of the first swirl chamber 20.

Here, the radius R1 of the valve seat opening portion 12b, the radius R2 of the intermediate opening portion 30a, and the distance L2 between the center axis a0 and the second swirl chamber 17b that does not communicate with the intermediate opening portion 30a have a relationship of R2 < L2 < R1.

The other structure is configured in the same manner as in embodiment 4.

The groove shape formed on the upper surface of the nozzle plate 13 of embodiment 7 includes: a first swirl chamber 20 in which the two swirl portions 18 communicate with each other through a fuel introduction portion 21; and two second swirl chambers 17b each composed of a swirl portion 18 and a fuel introduction portion 19. The first swirl chamber 20 is disposed such that the two swirl portions 18 are point-symmetrical about the central axis a 0. The two second swirl chambers 17b are disposed so as to sandwich the center axis a0 such that the longitudinal direction of the fuel introduction portion 19 coincides with the radial direction centered on the center axis a0, the longitudinal direction of the fuel introduction portion 19 is orthogonal to the longitudinal direction of the fuel introduction portion 21, and the distances from the center axis a0 to the fuel introduction portion 19 are equal. Further, the radius R1 of the valve seat opening portion 12b, the radius R2 of the intermediate opening portion 30a, and the distance L2 between the second swirl chamber 17b not communicating with the intermediate opening portion 30a and the central axis a0 have a relationship of R2 < L2 < R1. The nozzle hole 14 is formed only in the swirl portion 18 of the first swirl chamber 20.

Thereby, the fuel does not flow into the second swirl chamber 17b not used for injection. Further, by removing the intermediate plate 30, the fuel introduction portions 19 of the two second swirl chambers 17b are caused to enter the valve seat opening portion 12b, and the injection holes 14 are subsequently processed, whereby the number of the

first swirl chambers

20 and 17a communicating with the valve seat opening portion 12b, that is, the number of the injection holes 14 can be changed.

Therefore, also in embodiment 7, the same effects as those in embodiment 4 described above can be obtained.

Here, in embodiment 7, the two second swirl chambers 17b may be provided in groove shapes having different distances from the central axis a 0. In this case, the number of the injection holes 14 can be changed to two, three, and four simply by changing the diameter of the valve seat opening 12b with a single groove shape or by removing the intermediate plate 12 and performing subsequent processing on the injection holes 14. Thus, three types of different jet flows can be handled by a single groove shape. Further, the injection holes 14 may be formed in the first swirl chamber 20 and the second swirl chamber 17b in advance. Thus, three types of different jet flow rates can be handled by the single jet hole plate 13.

Embodiment 8

Fig. 11 is a view showing the periphery of a valve seat in a case of a small injection flow rate in a fuel injection valve according to embodiment 8 of the present invention, fig. 11 (a) is a vertical sectional view, and fig. 11 (b) is a sectional view taken along H-H direction of fig. 11 (a). Fig. 12 is a view showing the periphery of a valve seat in a case of a large injection flow rate in a fuel injection valve according to embodiment 8 of the present invention, fig. 12 (a) is a vertical sectional view, and fig. 12 (b) is a sectional view taken along line I-I of fig. 12 (a).

In fig. 11, two first swirl chambers 17a and two second swirl chambers 17b are disposed so as to sandwich the center axis a0, the fuel introduction portion 19 is directed toward the center axis a0, the longitudinal direction of the fuel introduction portion 19 is aligned with the radial direction around the center axis a0, and the distance between the fuel introduction portion 19 and the center axis a0 is equal. The diameter of the valve seat opening 12b increases, and the fuel introducing portions 19 of the first swirling chamber 17a and the second swirling chamber 17b enter the valve seat opening 12b at the same time. The intermediate plate 30 is disposed between the valve seat 12 and the nozzle plate 13. The valve seat 12, the intermediate plate 30, and the orifice plate 13 are integrally fixed to each other by a welding portion 16. An intermediate opening 30b having an arc shape with a smaller diameter than the valve seat opening 12b is formed coaxially with the valve seat opening 12b in the intermediate plate 30. Further, only the fuel introduction portion 19 of the first swirl chamber 17a communicates with the intermediate opening portion 30a when viewed from the direction of the center axis a 0. The nozzle hole 14 is formed only in the swirl portion 18 of the first swirl chamber 17 a.

In embodiment 8, by rotating the intermediate plate 30 about the axial center of the intermediate opening 30b, as shown in fig. 12, the fuel introduction portions 19 of the first swirl chamber 17a and the second swirl chamber 17b can be made to communicate with the intermediate opening 30a when viewed from the direction of the central axis a 0.

The groove shape formed on the upper surface of the injection hole plate 13 of embodiment 8 includes a first swirl chamber 17a and a second swirl chamber 17b each having a swirl portion 18 and a fuel introduction portion 19. The first swirl chamber 17a and the second swirl chamber 17b are disposed so as to sandwich the center axis a0 such that the longitudinal direction of the fuel introduction portion 19 coincides with the radial direction about the center axis a0 and the distance from the center axis a0 to the fuel introduction portion 19 is equal. The nozzle hole 14 is formed only in the swirl portion 18 of the first swirl chamber 17 a. Only the fuel introduction portion 19 of the first swirl chamber 17a enters the inside of the intermediate opening portion 30 b. Thereby, the fuel does not flow into the second swirl chamber 17b not used for injection. Further, the number of the first swirl chambers 17a communicating with the valve seat opening portion 12b, that is, the number of the injection holes 14 can be changed by changing the position of the intermediate plate 30 in the rotational direction about the axial center of the intermediate opening portion 30b to allow the fuel introduction portion 19 of the second swirl chamber 17b to enter the valve seat opening portion 12 b.

Therefore, also in embodiment 8, the same effects as those in embodiment 1 can be obtained.

According to embodiment 8, the number of the injection holes 14 can be changed without changing the valve seat 12 and the intermediate plate 30, and therefore, cost reduction can be achieved.

Further, if the injection holes 14 are formed in the first swirl chamber 17a and the second swirl chamber 17b in advance, it is possible to cope with two patterns having different injection flow rates by using a single injection hole plate 13.

In the above embodiments, the longitudinal direction of the fuel introduction portion coincides with the radial direction about the central axis a0, but the longitudinal direction of the fuel introduction portion does not necessarily have to coincide with the radial direction, and the longitudinal direction of the fuel introduction portion may be inclined with respect to the radial direction.

Description of the symbols

12 valve seats;

12a seat surface;

12b a valve seat opening part;

13, a spray orifice plate;

14, spraying holes;

15 balls (valve members);

17a first swirl chamber;

17b a second swirl chamber;

18 a turning part;

19 a fuel introducing part;

20 a first swirl chamber;

21 a fuel introducing part;

30 middle plates;

30a middle opening part;

30b are open at the middle.

Claims

1. A fuel injection valve comprising:

a valve seat having a truncated conical seat surface and a cylindrical seat opening portion, the seat surface being reduced in diameter toward a downstream side, the seat opening portion being formed on the downstream side of the seat surface coaxially with the seat surface, the seat surface of the valve seat and an axis of the seat opening portion being set as a central axis;

a valve member that is seated on the seat surface to prevent fuel from flowing out from the valve seat opening portion, the valve member being separated from the seat surface to allow fuel to flow out from the valve seat opening portion; and

an orifice plate disposed downstream of the valve seat such that a flat upper surface thereof faces upstream, a plurality of swirl chambers formed in the upper surface of the orifice plate, each of the plurality of swirl chambers including a swirl portion that applies a swirl force to the fuel and a fuel introduction portion that introduces the fuel into the swirl portion,

the fuel injection valve is characterized in that,

the plurality of swirl chambers are swirl chambers having different distances from the central axis, and each swirl chamber is composed of a first swirl chamber and a second swirl chamber, wherein the swirl portion of the first swirl chamber communicates with the valve seat opening portion via the fuel introduction portion, and the swirl portion of the second swirl chamber does not communicate with the valve seat opening portion,

an injection hole for injecting the fuel is formed in the swirl portion of the first swirl chamber.

2. The fuel injection valve according to claim 1,

the injection hole is formed in the swirl portion of the second swirl chamber.

3. The fuel injection valve according to claim 1 or 2,

the first swirl chamber and the second swirl chamber each have one fuel introduction portion and one swirl portion joined at an end portion of the one fuel introduction portion on a side opposite to the center axis,

when a distance between the first swirl chamber and the center axis is L1, a distance between the second swirl chamber and the center axis is L2, and a radius of the valve seat opening is R1, L1, L2, and R1 satisfy L1 < R1 < L2.

4. The fuel injection valve according to claim 1 or 2,

the first swirl chamber has two swirl portions arranged separately with the center shaft therebetween and one fuel introduction portion connecting the two swirl portions through the center shaft,

the second swirl chamber has one fuel introduction portion and one swirl portion joined at an end portion of the one fuel introduction portion on the opposite side to the center axis,

when the radius of the valve seat opening is R1 and the distance between the second swirl chamber and the central axis is L2, R1 and L2 satisfy R1 < L2.

5. The fuel injection valve according to claim 1 or 2,

an intermediate plate having an intermediate opening is disposed between the valve seat and the nozzle plate.

6. The fuel injection valve according to claim 5,

the first swirl chamber and the second swirl chamber each have one fuel introduction portion and one swirl portion joined to an end portion of the one fuel introduction portion on a side opposite to the central axis,

l1, L2, R1, and R2 satisfy L1 < R2 < L2 < R1, where L1 denotes a distance between the first swirl chamber and the central axis, L2 denotes a distance between the second swirl chamber and the central axis, R1 denotes a radius of the valve seat opening, and R2 denotes a radius of the intermediate opening.

7. The fuel injection valve according to claim 5,

when the radius of the valve seat opening is R1, the radius of the intermediate opening is R2, and the distance between the second swirl chamber and the central axis is L2, R1, R2, and L2 satisfy R2 < L2 < R1.

8. A method of adjusting an injection flow rate of a fuel injection valve, the fuel injection valve comprising:

the method for adjusting the injection flow rate of a fuel injection valve is characterized in that,

the number of swirl chambers, among the plurality of swirl chambers, in which the swirl portion communicates with the valve seat opening portion via the fuel introduction portion is adjusted by changing the diameter of the valve seat opening portion of the valve seat.

9. A method of adjusting an injection flow rate of a fuel injection valve, the fuel injection valve comprising:

a valve member that is seated on the seat surface to prevent fuel from flowing out from the valve seat opening portion, the valve member being separated from the seat surface to allow fuel to flow out from the valve seat opening portion;

an orifice plate disposed downstream of the valve seat such that a flat upper surface thereof faces upstream, the orifice plate having a plurality of swirl chambers formed in the upper surface thereof, each of the plurality of swirl chambers including a swirl portion that applies a swirl force to the fuel and a fuel introduction portion that introduces the fuel into the swirl portion; and

an intermediate plate disposed between the valve seat and the orifice plate and having an intermediate opening portion,

the number of swirl chambers, among the plurality of swirl chambers, in which the swirl portion communicates with the valve seat opening portion via the fuel introduction portion is adjusted by changing the diameter of the intermediate opening portion of the intermediate plate.

10. A method of adjusting an injection flow rate of a fuel injection valve, the fuel injection valve comprising:

an intermediate plate disposed between the valve seat and the orifice plate and having an arc-shaped intermediate opening portion formed coaxially with the valve seat opening portion,

the intermediate plate is rotated about the axis of the intermediate opening to adjust the number of swirl chambers among the plurality of swirl chambers, the swirl portions of which communicate with the valve seat opening via the fuel introduction portion.