JPH09112732A - Valve device and accumulator fuel injection device using the valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve device which can control a flow rate with high precision and a fuel injection device using the valve device. SOLUTION: A spherical member 43 which can shut off a high pressure introduction passage 52 and a valve seat chamber 25 is in contact with a conical recessed section 421 formed at an end on a high pressure side of a shaft member. The shaft member is opened for the conical recessed section 421 and is provided with a first communicating passage 422 which communicates with the low pressure side. The opening and the valve seat chamber 25 are shut off by a contact section between the spherical member 43 and the conical recessed section 421. When the spherical member 43 leaves a flat plate 51, high pressure fluid flows into the first communicating passage 422 through the valve seat chamber 25 and a second communicating passage 401 from the high pressure introduction passage 52. At this time, since pressure in the first communicating passage 422 is lower than pressure in the valve seat chamber 25, the spherical member 43 is sucked on a shaft member 44 side. Consequently, positional accuracy of the spherical member 43 is improved, and it is possible to control a flow rate with high precision because an area of opening between the flat plate 51 and the spherical member 43 is specified with high precision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve device for shutting off or connecting a fluid passage and a pressure accumulating fuel injection device using this valve device.

[0002]

2. Description of the Related Art Conventionally, there has been known a valve device which shuts off or connects a high pressure side and a low pressure side of a fluid passage. As an example of such a valve device, a seat member having a high pressure introduction passage disposed between the high pressure side and the low pressure side of the fluid passage, and a conical seat formed around the high pressure introduction passage on the high pressure side end surface,
A spherical member that closes the high-pressure introduction passage by sitting on the conical seat, and a valve member that is a bar-shaped member that abuts the spherical member and can drive the spherical member toward the conical seat, and retains the rod-shaped member. There is one that is composed of a cylinder and an actuator that drives the rod-shaped member. When the rod-shaped member is moved to the high pressure side by the driving force of the actuator, the spherical member is seated on the conical seat, whereby the high pressure introduction passage is closed and the valve device is closed. An example of the valve device having the above structure is disclosed in European Patent Application No. 548916A1.

On the other hand, in Japanese Unexamined Patent Publication No. 5-133296, a high pressure introduction passage is provided between the high pressure side and the low pressure side of the fluid passage, and a flat seat is provided around the high pressure introduction passage on the end face of the low pressure passage. A formed sheet member, a plate-like member that closes the high-pressure introduction passage by sitting on the plane seat, and a rod-shaped member that has a spherical surface formed on the high-pressure side and the spherical surface contacts the low-pressure side of the plate-shaped member There is disclosed a fuel injection device for an electromagnetic internal combustion engine, which is provided with a valve device having a valve member made of. In this structure, the rod-shaped member and the spherical member are driven by an actuator to bring the flat surface into close contact with the flat valve seat, thereby blocking the fluid passage.

[0004]

However, according to the valve device disclosed in European Patent Application No. 548916A1, the fluid passage is blocked by bringing the spherical member and the conical seat into close contact with each other. It is necessary to process both the spherical member and the conical seat with high precision.
Therefore, there is a problem that the manufacturing cost of the valve device increases.

Further, according to the valve device disclosed in the above-mentioned JP-A-5-133296, there is a pressure distribution due to the fluid in the high-pressure introducing passage on the flat surface, but when the valve device is in the open state, When this pressure distribution is biased with respect to the center of gravity of the plate member, a force acts on the plate member to rotate the plate member non-parallel to the plane seat. As a result, when the plate member rotates and the flat surface tilts with respect to the flat seat, the plate shape is perpendicular to the extending direction of the high pressure introduction passage due to the pressure of the fluid flowing from the high pressure introduction passage. Since the member is pushed, the position of the plate member becomes unstable. Therefore, when the valve device is continuously opened and closed, the opening area of the fluid passage varies when the valve device is opened, so that the flow rate cannot be controlled with high accuracy. In particular, when the valve device is operated at a high speed, the position of the plate member becomes more unstable because the dynamic pressure acting on the plate member is large, and it is difficult to control the minute flow rate.

An object of the present invention is to provide a valve device capable of controlling the flow rate with high accuracy. Another object of the present invention is to provide a pressure accumulation type fuel injection device using the valve device.

[0007]

According to a first aspect of the present invention, there is provided a valve device according to claim 1, wherein the support member is formed with a first communication passage opening to the valve body side and communicating with a low pressure side of the fluid passage. The main body shuts off the low pressure chamber around the valve main body and the opening, and the low pressure chamber is communicated with the first communication passage or the low pressure side by a second communication passage. Since the low pressure chamber around the valve body is blocked from the opening, the pressure in the first communication passage is higher than the pressure in the low pressure chamber when the valve device is opened so that the valve body is separated from the seat member. Is lower, the valve body is sucked toward the support member. Since this suction force can maintain a stable contact state between the valve body and the support member, the opening area between the seat member and the valve body is accurately defined with respect to the movement amount of the support member. Therefore, the flow rate can be controlled with high accuracy. Further, since the support member is a hollow shape having the first communication passage, the responsiveness of the valve device is improved by reducing the inertial mass of the valve member, and the end portion of the support member can be machined. It's easy.

According to another aspect of the valve device of the present invention, the contact portion between the support member and the valve body has a conical concave surface and a spherical convex surface.
Alternatively, it is characterized by being constituted by a combination of a spherical concave surface and a spherical convex surface. Thereby, for example, the surface pressure acting on the contact portion is higher than in the case where the flat surfaces are combined, and the contact by the contact portion is maintained even when either the valve body or the support member is inclined. For,
The low pressure chamber and the first communication passage can always be satisfactorily shut off. Thereby, a pressure difference can be generated between the low pressure chamber and the first communication passage.

According to a fifth aspect of the valve device of the present invention, a plurality of the first communication passages are formed at equal intervals on the same circumference centered on the axis of the support member in the cross section of the support member. And This makes it possible to equalize the suction force acting on the valve body with respect to the shaft of the support member. According to the valve device of the sixth or seventh aspect, the passage resistance of the second communication passage is made larger than the passage resistance of the first communication passage by a method such as providing a throttle means in the second communication passage. Thereby, the low pressure chamber and the first
Since the pressure difference between the communication passage and the communication passage becomes larger, the suction force of the valve body to the support member increases, so that the positional accuracy of the valve body is further improved.

According to the pressure-accumulation fuel injection device of the eighth aspect, since the valve device according to any one of the first to seventh aspects is used as the two-way valve device, the pressure of the pressure control chamber for each stroke is increased. Since the change and the movement of the needle valve can be controlled with high accuracy, the fuel injection amount from the injection nozzle becomes stable.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A valve device according to a first embodiment of the present invention is shown in FIGS. The valve device 1 shown in FIG. 1 has a fluid passage in which the upper side is the low pressure side and the lower side is the high pressure side in FIG. 1, and the high pressure side and the low pressure side of this fluid passage are blocked or conducted. is there.

Inside the housing 40, a flat plate 51 as a seat member arranged between the high pressure side and the low pressure side of the fluid passage, and a spherical shape as a valve main body capable of contacting the flat plate 51. A valve member 41 and a valve member 4 each including a member 43 and a support member 42 that supports the spherical member 43.
A cylinder 21 for supporting 1 to be capable of reciprocating in the axial direction;
The actuator 31 that drives the valve member 41 in the valve opening direction or the valve closing direction is accommodated.

The flat plate 51 has a high-pressure introducing passage 52 that penetrates in the axial direction, and the high-pressure side end surface 5 of the flat plate 51.
4 has a conical seat 5 around the opening of the high-pressure introduction passage 52.
41 are formed. A sealing member 56 is screwed onto the high pressure side of the flat plate 51. The high-voltage-side connector 57 having the high-pressure passage 2 that is screwed into the sealing member 56 and penetrates in the axial direction penetrates the sealing member 56 and has a tip thereof conical seat 54.
It adheres to 1.

The cylinder 21 has a cylindrical portion 22 and a flange portion 2.
3, the flange portion 23 is in contact with the low pressure side end surface 55 of the flat plate 51. A valve seat chamber 25, which has a diameter larger than that of the sliding hole, is formed coaxially with the sliding hole and the high pressure side of the sliding hole. Further, the cylinder 21 is provided with groove holes 231 penetrating the flange portion 23 and extending along the outer wall of the cylinder portion 22 in the axial direction of the cylinder 21 at 90 ° intervals. A second communication path 401 is formed inside the groove 231 and between the groove 231 and the inner wall 40 a of the housing 40. A communication hole 232 that communicates the valve seat chamber 25 with the communication hole 231 is formed in the high pressure side end surface of the flange portion 23 while the flange portion 23 is in contact with the low pressure side end surface 55. Further, the cylindrical portion 22 is formed with a communication hole 221 that communicates the second communication passage 401 with the sliding hole.

The support member 42 of the valve member 41 includes a shaft member 44 as a support member main body which is reciprocally supported by the inner wall of the cylinder 21 forming the sliding hole, and the shaft member 4.
4 and a substantially cylindrical coupling member 45 fitted to the outer periphery of the high-pressure side end portion of No. 4. The low-pressure side end of the connecting member 45 has a reduced diameter, and by pressing the spherical member 43 into the connecting member 44, the spherical member 43 is slidably supported by the shaft member 44 via the connecting member 45. . The spherical member 43 and the connecting member 45 are located in the valve seat chamber 25 as a low pressure chamber.

At the center of the shaft of the shaft member 44, a first communication passage 422 is formed penetrating in the axial direction. A port 425 is provided at a position corresponding to the communication hole 221 on the outer wall of the shaft member 44, and the communication hole 42 opened to the port 425.
4, the second communication passage 401 and the first communication passage 422 are communicated with each other. An armature 46 is fixed to the low pressure side end of the shaft member 44.

The spherical member 43 has a circular flat surface 43 by cutting a portion facing the low pressure side end surface 55 with a flat surface.
1 is formed. A valve seat portion 551 which is a flat valve seat is formed around the high pressure introduction passage 52 on the low pressure side end surface 55, and when the spherical member 43 is seated on this valve seat portion 551, the high pressure introduction passage 52 is closed by the flat surface 431. As a result, the communication between the high pressure introduction passage 52 and the valve seat chamber 25 is cut off, and the valve device 1 is closed. Further, between the spherical member 43 and the conical concave surface 421, a circumferential contact portion 432 centering on this axis is formed in a plane perpendicular to the axis of the conical concave surface 421. The conical concave surface 4 located on the low pressure side of the contact portion 432.
A cavity portion 423, which communicates with the first communication passage 422 and is disconnected from the valve seat chamber 25, is formed between the valve member 21 and the spherical member 43.

The actuator 31 housed on the low pressure side of the armature 46 has a core 3 around which an electromagnetic coil 33 is wound.
Consists of two. A low voltage side connector 61 is provided on the low voltage side of the core 32 via a core stopper 36. The low voltage side connector 61 is formed with a low pressure passage 3 provided on the low pressure side and a spring chamber 62 having one end opened to the high pressure side and the other end communicating with the low pressure passage 3. In the spring chamber 62, a spring 63 whose one end is locked by a spring stopper 64 having a through hole 641 is accommodated.

A sliding hole 311 penetrating in the axial direction is formed inside the core 31, and a transmission member 35 is reciprocally inserted into the sliding hole 311. Transmission member 35
Has one end abutting on the low pressure side end of the shaft member 44, and a flange 351 is formed on the low pressure side end, which penetrates the core stopper 36 and is inserted into the spring chamber 62. Tsuba 35
The other end of the spring 63 is locked to 1 so that the transmission member 35 urges the valve member 41 to the high pressure side by the elastic force of the spring 63. A communication hole 352 is formed at the axial center of the transmission member 35 and penetrates in the axial direction to communicate with the spring chamber 62 and the first communication passage 422.

When the valve device 1 is in the open state, the high pressure fluid flows from the high pressure passage 2 into the high pressure introduction passage 52 and the valve seat chamber 2.
5, communication hole 232, second communication path 401, communication hole 221,
It flows out to the low pressure side via the fluid passage formed by the communication hole 424, the first communication passage 422, the communication hole 352, the spring chamber 62, the through hole 641, and the low pressure passage 3. This valve device 1
Is assembled as follows.

From the high pressure side opening of the housing 40, the cylinder 21, the flat plate 51 and the sealing member 56 are assembled in this order. The part where the cylinder 21, the flat plate 51, and the sealing member 56 contact each other is mirror-finished. A screw portion 56a is provided on the outer periphery of the sealing member 56 on the low pressure side, and the screw portion 56a is screwed into a screw portion 40b provided on the inner periphery of the end portion of the high pressure side of the housing 40, whereby the cylinder 21, the flat plate Plate 51, sealing member 56
The mirror-finished parts of the two come into liquid-tight or air-tight contact with each other. A threaded portion 56b is also provided on the inner diameter of the sealing member 56. By screwing the threaded portion 57b on the outer periphery of the high-voltage side connector 57 into the threaded portion 56b, the tip portion 57a is formed.
The high-voltage-side connector 57 is attached to the sealing member 56 so that the seal contacts the conical seat 541. Here, the O-ring 561 mounted on the outer periphery of the sealing member 56 prevents the fluid flowing from the high pressure passage 2 from leaking to the outside of the valve device 1.

After assembling the valve member 41, the spacer 37, the actuator 31 and the low voltage side connector 61 in this order from the low pressure side opening of the housing 40, the low pressure side end of the housing 40 is caulked. By changing the axial length of the cylindrical spacer 37, the distance between the armature 46 and the electromagnetic coil 32 can be set and the lift amount of the valve member 41 can be adjusted. Also, the low voltage side connector 6
The O-ring 611 mounted on the outer periphery of the valve 1 prevents the fluid from leaking to the outside of the valve device 1.

The dimensions of each part of the valve device 1 are as follows. Diameter of high pressure introduction passage 52 = 0.5 mm, flat surface 43
1 diameter = 1.6 mm, spherical member 43 diameter = 2.5 mm,
Stroke of valve member 41 = 0.2 mm, first communication passage 42
2 diameter = 1.2 mm, 2nd communication path 401 diameter = 1.5 m
m, the outer diameter of the shaft member 44 = 4.0 mm.

Next, the operation of the valve device 1 will be described. The load of the spring 63 as the biasing means for biasing the valve member 41 to the flat plate 51 is set to about 50N,
The pressure of the high pressure fluid flowing from the high pressure introduction passage 52 is 150
When the pressure is MPa, the valve opening force that acts on the flat surface 431 of the spherical member 43 due to the static pressure of the fluid flowing from the high pressure introduction passage 52 is 41.6N. When the electromagnetic coil 33 is not energized, the urging force of the spring 63 is larger than the valve opening force of the high-pressure fluid, so the valve device 1 is in the valve closed state in which the spherical member 43 is seated on the valve seat portion 551. The fluid passage is blocked.

When the electromagnetic coil 33 is energized, the magnetic force generated in the electromagnetic coil 33 attracts the armature 46 to the electromagnetic coil 33 with an electromagnetic force of about 50N. For this reason, the shaft member 44 lifts upward in FIG. 1 by overcoming the urging force of the spring 63, so that the spherical member 43 moves toward the valve seat portion 55.
When the valve device 1 is separated from the valve device 1, the valve device 1 is opened, and the fluid passage is communicated.

When the energization of the electromagnetic coil 33 is turned off at the predetermined valve opening end timing, the electromagnetic force of about 50 N for attracting the armature 46 becomes 0, so that the spring 63 for urging the valve member 41 in the valve closing direction. The valve device 1 is closed by the urging force of. FIG. 3 shows a schematic pressure distribution of the static pressure acting on the spherical member 43 when the valve device 1 is opened. As a comparative example, FIG. 4 shows the pressure distribution when the first communication passage 422 is not formed in the shaft member. 4, the same reference numerals as those in the first embodiment denote substantially the same members.

When the valve device 1 is opened, the pressure of the fluid flowing from the high pressure introducing passage 52 is the same as that of the high pressure introducing passage 5.
In the valve seat chamber 25, the pressure decreases from P1 to P2. In the first embodiment shown in FIG. 3, the fluid in the valve seat chamber 25 has a communication hole 232, a second communication passage 401, and a communication hole 2.
Although it flows through 21 into the first communication passage 422, the pressure of the fluid in the first communication passage 422 further decreases to the pressure P3 due to the flow passage resistance therebetween. Between these pressures, P1
>P2> P3.

According to the first embodiment, the pressure P2 in the valve seat chamber is
The forces from the sides of the spherical member 43 due to act on the spherical surface and cancel each other out. On the other hand, on the flat surface 431 facing the high-pressure introduction passage 52, a pressure distribution is formed that decreases from the pressure P1 to the pressure P2 from the center of the flat surface 431 located immediately above the high-pressure introduction passage 52 toward the peripheral portion. To be done. On the other hand, the pressure of the fluid in the cavity portion 423 communicating with the first communication passage 422 is substantially equal to the pressure P3, or when the valve device 1 is opened, the communication hole 232 shown in FIG. The communication hole 23 is formed by the force of the fluid flowing in the first communication passage 422.
The fluid in the first communication passage 422 located on the valve body 43 side of No. 2 is sucked out, so that the pressure of the fluid in the cavity 423 becomes smaller than the pressure P3. Therefore, the pressure P3 or a pressure slightly lower than this is applied to the surface of the spherical member 43 facing the cavity 423. Therefore, the cavity 4
Due to the pressure difference between the surface of the spherical member 43 facing 23 and the flat surface 431, a suction force acts on the spherical member 43 toward the shaft member 44.

On the other hand, in the case of the comparative example shown in FIG. 4 which does not have the first low pressure passage 422 and the cavity portion 123 and the valve seat chamber 25 are not blocked by the contact portion 132, the cavity portion 123.
And the pressure in the valve seat chamber 25 both become the pressure P2, so that the force for sucking the spherical member 43 toward the shaft member 144 does not work. In addition to the static pressure considered above, the spherical member 43 has a flat surface 431 to which the fluid flowing from the high-pressure introduction passage 52 flows.
By colliding in a direction perpendicular to the flat surface 431
Since it has the largest dynamic pressure distribution at the center of
The center of 1 is the place where the action of pressure is the largest. When this pressure distribution is biased with respect to the center of the spherical member 43, the rotational force A acts on the spherical member 43 as shown in FIG. In the comparative example in which the force for attracting the spherical member 43 to the shaft member 144 side does not work, the flat surface 431 is likely to be inclined due to this rotational force A, and due to this inclination, the flat surface 431 is perpendicular to the direction in which the high pressure introduction passage 52 extends in the spherical member 43. The force B acts on the spherical member 43, which makes the position of the spherical member 43 unstable.

On the other hand, according to the first embodiment, since the spherical member 43 is attracted to the shaft member 44 side, even when the rotational force A is exerted, the spherical member 43 has a flat surface. The inclination of 431 can be suppressed. Therefore, the positional accuracy of the spherical member 43 is improved, and the spherical member 43 and the shaft member 44 can be maintained in a stable contact state.
Thus, according to the first embodiment of the present invention, the spherical member 4
Since the positional accuracy of 3 is improved and the spherical member 43 and the shaft member 44 can maintain a stable contact state, the shaft member 44
The opening area between the flat plate 51 and the spherical member 43 is defined with high accuracy with respect to the moving amount of the valve device 1.
In case of continuous operation, the variation of the opening area for each stroke becomes small, and the flow rate can be controlled with high accuracy. In particular, there is an effect that the minute flow rate can be controlled with high accuracy when the valve device 1 is operated at high speed.

The fluid passage formed in the valve device 1 is blocked by the flat surface 431 of the spherical member 43 seating on the flat valve seat 551 of the flat plate 51. In this way, the flat surfaces are in close contact with each other, so that the high-pressure introducing passage 5
Since 2 is closed, it is easier to process the contact portion than when the high pressure introducing passage is closed by, for example, closely adhering the valve body having a spherical convex portion to the valve seat having a conical concave surface. In addition, the conical concave surface 421 and the spherical member 43 formed on the shaft member
The contact portion 432 with the can generate a pressure difference between the hollow portion 423 and the first communication passage even if these members are not completely in close contact with each other, so that the valve element forming the spherical convex portion is conical. It is easier to process because it does not require the same strict machining accuracy as when closing the high-pressure introduction passage by closely contacting with the concave valve seat.

The spherical member 43 forms a contact portion 432 between the conical concave surface 421 provided on the end surface of the shaft member 44 on the high pressure side and the spherical convex surface of the spherical member 43, thereby forming the valve seat chamber 25.
And the cavity 423 are blocked. In this way, the circumferential contact portion 432 is formed by combining the conical concave surface and the spherical convex surface.
Therefore, the surface pressure acting on the contact portion is higher than that in the case of combining the flat surfaces with each other, and the spherical member 43
Even when either of the shaft member 44 and the shaft member 44 is tilted, the contact by the circumferential contact portion is maintained, so that the hollow portion 423 and the valve seat chamber 25 can be always shut off satisfactorily.
Thereby, a pressure difference can be generated between the hollow portion 423 and the valve seat chamber 25.

Further, since the shaft member 44 has a hollow shape having the first communication passage 422, the responsiveness of the valve device 1 is improved by reducing the inertial mass of the valve member 41, and the shaft member 44 has a high pressure side. The workability when processing the conical recess 421 on the end is good. (Second Embodiment) FIGS. 6 to 10 show a valve device according to a second embodiment of the present invention. The second embodiment is an example in which throttling means is provided in the fluid passage extending from the valve seat chamber 25 to the first communication passage 422. The same reference numerals as those in the first embodiment indicate substantially the same members.

FIG. 6 shows a first example of the diaphragm means.
This is an embodiment in which the opening area of the communication passage 821 is smaller than that of the communication passage 221 of the embodiment. The configuration of the other parts is substantially the same as that of the first embodiment. FIG. 7 shows another example of the throttle means in which the opening area of the communication passage 832 is smaller than that of the communication passage 232 of the first embodiment. The configuration of the other parts is substantially the same as that of the first embodiment.

FIG. 8 shows, as still another example of the throttle means, an embodiment in which a throttle portion 811 is provided in the second communication passage 801 formed in the flange portion 23. The configuration of the other parts is substantially the same as that of the first embodiment. FIG. 9 shows an embodiment in which a throttle portion 825 is provided on the first communication passage 422 side of the communication passage 824 as still another example of the throttle means. The configuration of the other parts is substantially the same as that of the first embodiment.

According to the embodiment shown in FIGS. 6 to 9, since the throttling means is provided, the valve seat chamber 25 to the first communication passage 4
Since the passage resistance of the fluid passage portion reaching 22 increases,
The pressure difference between the valve seat chamber 25 and the cavity 423 becomes large. As a result, the suction force of the spherical member 43 to the shaft member 44 increases, so that the positional accuracy of the spherical member 43 is further improved, and the spherical member 43 and the shaft member 44 can maintain a stable contact state. is there.

FIG. 10 shows another embodiment of the throttle means in which the opening area of the second communication passage 802 is smaller than that of the second communication passage 401 of the first embodiment.
The configuration of the other parts is substantially the same as that of the first embodiment. According to the embodiment shown in FIG. 10, the pressure difference between the valve seat chamber 25 and the cavity portion 423 is increased as in the embodiment shown in FIGS. 6 to 9, and the conical recess 421 and the spherical member 43 are used.
At the contact portion 432 between the valve seat chamber 25 and the cavity portion 42.
3 is not completely shut off from the valve seat chamber 25 to the cavity 423.
Even if the flow to the first side is generated, there is an effect that the first communication passage 422 and the cavity portion 423 can be maintained at a low pressure.

(Third Embodiment) FIG. 11 shows a valve device according to a third embodiment of the present invention. In this third embodiment, the spherical member 43 is press-fitted into the connecting member 45, so that the connecting member 4
This is an example in which the method of connecting the spherical member 43 to the support member is different from the first embodiment in which the spherical member 43 is connected to the shaft member 44 via 5.

As shown in FIG. 11, the supporting member 842 is composed of a shaft member 844 without using a connecting member, and the spherical member 43 is supported by the supporting member 842 by caulking the high pressure side end of the shaft member 844. There is. The configuration of the other parts is substantially the same as that of the first embodiment. According to this method, since the connecting member is not used, the number of parts is reduced, and the manufacturing cost of the valve device can be reduced.

It is also possible to support the spherical member on the support member by integrally providing a cylindrical portion with the high pressure side end portion having a reduced diameter in advance at the tip of the shaft member and press-fitting the spherical member into this cylindrical portion. is there. (Fourth Embodiment) FIGS. 12 and 13 show a valve device according to a fourth embodiment of the present invention. In the fourth embodiment, a circular contact portion 432 is formed by combining a conical concave surface and a spherical convex surface.
This is an example in which the method of configuring the contact portion is different from that of the first embodiment configured as described above.

FIG. 12 shows an embodiment in which a spherical concave surface 321 is provided on the high pressure side end surface of the shaft member 344. In this case, the first communication passage 422 is provided between the spherical member 43 and the spherical concave surface 321.
Around the shaft member 344 forming the
Is formed. The spherical member 43 is sucked toward the shaft member 344 by the pressure difference between the valve seat chamber 25 and the first communication passage 422.
The configuration of the other parts is substantially the same as that of the first embodiment.

FIG. 13 shows an embodiment in which a flat surface 521 is provided on the high pressure side end surface of the shaft member 544 and the high pressure side end portion of the first communication passage 522 is branched into a plurality of branch communication passages 522a. The spherical member 43 is in contact with the shaft member 544 at one point in the center of the flat surface 521. In this case, the pressure difference between the valve seat chamber 25 and the first communication passage 522 is the circumferential contact portion 532 formed between the inner wall of the connecting member 545 and the spherical member 43.
Occurs when the valve seat chamber 25 and the hollow portion 523 are substantially cut off from each other. The configuration of the other parts is the first
This is substantially the same as the embodiment.

In the embodiment shown in FIGS. 12 and 13, the surface pressure acting on the contact portion is higher than in the case where the flat surfaces are combined with each other, and the spherical member 43 and the supporting members 442, 5 are used.
Even if any of the 42 is tilted, the contact by the circumferential contact portion is maintained, so that the first communication passage and the valve seat chamber 25 can always be favorably blocked. Therefore, a pressure difference can be generated between the hollow portion 423 and the valve seat chamber 25.

In the embodiment shown in FIG. 13, the high pressure side end of the first communication passage 522 is branched into a plurality of branch communication passages 522a. The branch communication passage 522a is provided in the support member 5
In the cross section of 42, they are arranged at equal intervals on the same circumference centered on the axis of the support member 542. This makes it possible to make the pressure distribution in the cavity 523 uniform with respect to the axis of the support member 542.

(Fifth Embodiment) FIG. 1 shows a fifth embodiment of the present invention.
It is shown in FIG. The fifth embodiment is an example in which the valve device according to the first embodiment is used as a two-way valve device of a pressure accumulation type fuel injection device. The pressure accumulation type fuel injection device 135 shown in FIG.
High-pressure fuel accumulated in a common rail (not shown) is supplied to an injector provided for each cylinder of a diesel internal combustion engine (not shown), and fuel is injected from an injection nozzle of this injector into the combustion chamber of each cylinder.

The fuel injection device 135 includes an injection nozzle 136.
Needle valve 138 for opening and closing the injection hole 137 of the
A pressure pin 140 inserted into a spring 139 that contacts or is connected to the side opposite to the injection hole of the needle valve 138 and biases the needle valve 138 in the valve closing direction; The control piston 142, which is in contact with or connected to the injector body 141 and is slidable in the injector body 141, is in communication with the high-pressure fuel introduction passage 143 and the low-pressure passage 103.
Control chamber 1 for storing fuel for urging the valve in the valve closing direction
46, and an injection fuel introduction passage 147 that guides high-pressure fuel injected from the injection hole 137 to the injection hole 137 of the injection nozzle 136 when the needle valve 138 is opened.

A first throttle hole 148 for restricting the fuel flowing into the control chamber 146 is provided between the high pressure fuel introduction passage 143 and the control chamber 146, and the control chamber 146 and the low pressure passage 103 are connected to each other. A second throttle hole 149 having a passage resistance smaller than that of the first throttle hole 148 is provided between them. Second
Between the throttle hole 149 and the low-pressure passage 103 of the control chamber 1
The valve device 1 according to the first embodiment is provided as a two-way valve device that connects and disconnects 46 and the low pressure side.

Further, in FIG. 12, 150 is a filter, 151 is a nozzle packing tip, 152 is a nozzle retaining nut, 153 is a connector of the valve device 1,
Reference numeral 154 is a retaining nut of the valve device 1, and 155 is a connector for collecting leaked fuel. Furthermore, passage 15
Reference numeral 6 is a low pressure passage for collecting leaked fuel from the sliding clearance between the control piston 142 and the needle valve 138, and this passage 156 communicates with the second communication passage 401 of the valve device 1 connected to the low pressure passage 103. doing. In this pressure accumulating fuel injection device 135, a first throttle hole 148 is arranged in the high pressure introducing passage 52 of the valve device 1 shown in FIG. 1, and a connector 155 for collecting leak fuel is assembled in place of the low pressure side connector 61. It is attached.

The operation of the pressure accumulating fuel injection device 135 will be described. The high-pressure fuel accumulated in the common rail passes through a fuel pipe (not shown) to accumulate pressure.
The high pressure fuel introduction passage 143 of 35 flows into the first throttle hole 148 and the injected fuel introduction passage 147 in a branched manner. At this time, the needle valve 138 moves the spring 139.
Therefore, the injection is not performed because it is urged in the valve closing direction via the pressure pin 140. Also, the valve device 1
Is closed by the biasing force of the spring 62.

When the pressure in the high pressure fuel introduction passage 143 gradually rises, the control piston 142 is driven by the pressure of the high pressure fuel in the control chamber 146 in addition to the urging force of the spring 139.
Urges the needle valve 138 in the valve closing direction. This pressure increase rate is about 25 to 30 MPa immediately after starting the internal combustion engine.
/ Sec. Here, since the pressure receiving area of the control piston 142 is larger than the pressure receiving area of the needle valve 138, fuel is not injected from the injection nozzle 136 when the valve device 1 is not opened. In the fifth embodiment, the diameter of the control piston 142 = 5.0 mm, the needle valve 13
Since the diameter of 8 == 4.0 mm and the seat diameter of the needle valve 138 = 2.25 mm, the difference between the pressure receiving area of the control piston 142 and the pressure receiving area of the needle valve 138 is about 11 mm.
Set to ² .

Further, the set load of the spring 63 of the valve device 1 is about 50 N, and for example, when the pressure of the control chamber 146 is 150 MPa, the pressure acting in the valve opening direction of the valve device 1 is 41.6 N. The valve device 1 does not open due to the pressure in the control chamber 146. In this state,
When the electromagnetic coil 33 is energized, the valve device 1 opens as described in the first embodiment. As a result, the control room 146
Fuel flows out from the second throttle hole 149 through the valve seat chamber 25, the second communication passage 401, the first communication passage 422 and the low pressure passage 103 to a leak fuel recovery pipe (not shown).

When the outflow of high-pressure fuel into the control chamber 146 starts for a while, the pressure in the control chamber 146 becomes relatively lower than the pressures in the high-pressure fuel introduction passage 143 and the injected fuel introduction passage 147. This is compared with the passage area of the first throttle hole 148 for regulating the fuel introduced into the control chamber 146, and the passage area of the second throttle hole 149 for regulating the fuel flowing out from the control chamber 146. Because it is configured large. In this fifth embodiment, the first throttle hole 1
Diameter of 48 = 0.3 mm, diameter of second throttle hole 149 =
0.5 mm. When the pressure in the control chamber 146 further decreases, the force relationship between the hydraulic load acting on the needle valve 138 in the valve opening direction, the hydraulic load acting on the control piston 142 in the valve closing direction, and the set load of the spring 139 is reversed, and the nozzle opening valve is opened. The force in the direction prevails and the needle valve 138 lifts, so that fuel is started from the injection hole 137.

When the energization of the electromagnetic coil 33 is turned off at the predetermined injection end timing, the electromagnetic force 50N for attracting the armature 46 becomes 0, so that the valve device 1 is closed by the urging force of the spring 63. Then, high-pressure fuel is introduced into the control chamber 146 through the high-pressure fuel introduction passage 143,
The pressure in the control chamber 146 gradually returns to the state before opening the valve device 1. When the force relationship between the sum of the hydraulic loads acting on the needle valve 138 and the set load of the spring 139 reverses in the valve closing direction of the needle valve 138 during the process of increasing the pressure in the control chamber 146, the needle valve 138 blocks the injection hole 137. Therefore, the injection nozzle 136 closes and the injection ends.

According to the pressure-accumulation type fuel injection device of the fifth embodiment, since the valve device 1 of the first embodiment is used as the two-way valve device, the movement of the shaft member 44 is always made spherical.
Can be accurately transmitted to 3. As a result, the opening area between the spherical member 43 and the flat plate 51 can be stabilized, so that when the valve device 1 is continuously operated, the variation in the opening area for each stroke is reduced.
The flow rate can be controlled with high accuracy. Therefore, the fuel injection amount from the injection nozzle 136 becomes stable. In particular, there is an effect that the minute fuel injection amount can be controlled with high accuracy when the pressure accumulation type fuel injection device 135 is operated at high speed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a valve device according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a main part of FIG.

FIG. 3 is a cross-sectional view schematically showing the pressure acting on the spherical member in the first embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically showing the pressure acting on the spherical member when the first communication passage is not provided.

FIG. 5 is a cross-sectional view schematically showing the pressure acting on the spherical member when the first communication passage is not provided.

FIG. 6 is an enlarged sectional view of an essential part showing an example of a valve device according to a second embodiment of the present invention.

FIG. 7 is an enlarged sectional view of an essential part showing another example of the valve device according to the second embodiment of the present invention.

FIG. 8 is an enlarged sectional view of an essential part showing still another example of the valve device according to the second embodiment of the present invention.

FIG. 9 is an enlarged sectional view of an essential part showing still another example of the valve device according to the second embodiment of the present invention.

FIG. 10 is an enlarged sectional view of an essential part showing still another example of the valve device according to the second embodiment of the present invention.

FIG. 11 is an enlarged sectional view of an essential part showing an example of a valve device according to a third embodiment of the present invention.

FIG. 12 is an enlarged sectional view of an essential part showing an example of a valve device according to a fourth embodiment of the present invention.

FIG. 13 is an enlarged sectional view of an essential part showing another example of the valve device according to the fourth embodiment of the present invention.

FIG. 14 is a sectional view showing a pressure accumulation type fuel injection device according to a fifth embodiment of the present invention.

[Explanation of symbols]

 1 Valve Device 2 High Pressure Passage 3 Low Pressure Passage 21 Cylinder 25 Valve Seat Chamber (Low Pressure Chamber) 31 Actuator 33 Electromagnetic Coil 40 Housing 41 Valve Member 42 Support Member 43 Spherical Member (Valve Main Body) 44 Shaft Member (Supporting Member Main Body) 45 Connecting Member 46 Armature 51 Flat plate (sheet member) 52 High-pressure introduction passage 135 Accumulation type fuel injection device 137 Injection hole 138 Needle valve 142 Control piston 146 Control chamber (pressure control chamber) 221, 232, 352, 424 Communication passage 401 Second communication passage 421 conical concave part 423 hollow part 431 flat surface 432 contact part

Claims (8)

[Claims] 1. A valve device for disconnecting or connecting a high pressure side and a low pressure side of a fluid passage, the sheet member having a high pressure introduction passage arranged between the high pressure side and the low pressure side of the fluid passage, A valve member having a valve body that closes the high-pressure introduction passage by abutting the seat member, and a support member that abuts the valve body at a high-pressure side end, and the valve member can reciprocate in the axial direction. A first supporting cylinder that is open to the valve body side and that communicates with the low pressure side of the fluid passageway, and a cylinder that supports the valve member and an actuator that drives the valve member in a valve opening direction or a valve closing direction. A passage is formed, the valve body blocks the low pressure chamber around the valve body from the opening, and the low pressure chamber and the first communication passage or the low pressure side are provided with a second passage.
A valve device characterized by being communicated by a communication passage. 2. The valve according to claim 1, wherein a contact portion between the support member and the valve body is constituted by a conical concave surface and a spherical convex surface, or a combination of a spherical concave surface and a spherical convex surface. apparatus. 3. The supporting member comprises a supporting member main body and a cylindrical connecting member, and the valve main body is supported by the supporting member by caulking the connecting member or press-fitting into the connecting member. The valve device according to claim 1 or 2, characterized in that: 4. The valve device according to claim 1, wherein the first communication passage extends in the axial direction of the support member. 5. The plurality of the first communication passages are formed at equal intervals on the same circumference centered on the axis of the support member in a cross section of the support member.
The valve device described. 6. The valve device according to claim 1, wherein throttling means is provided in the second communication passage. 7. The passage resistance of the second communication passage is larger than the passage resistance of the first communication passage.
7. The valve device according to any one of 1 to 6. 8. A pressure-accumulation fuel injection device for supplying high-pressure fuel accumulated in a common rail to an injector provided for each cylinder of a diesel internal combustion engine, and injecting fuel from an injection nozzle of the injector into a combustion chamber of each cylinder. A high-pressure fuel passage capable of supplying high-pressure fuel to the injection hole of the injection nozzle, and a needle valve for connecting and disconnecting the injection hole; and a needle valve provided on the side opposite to the injection hole of the needle valve so as to reciprocate together with the needle valve. Control piston, a pressure control chamber for urging the control piston in the injection hole blocking direction by a fuel pressure provided on the side opposite to the injection hole of the control piston and supplied from the high pressure fuel passage, and a low pressure fuel passage or low pressure fuel. A two-way valve device that connects and disconnects with the chamber, wherein the valve device according to any one of claims 1 to 7 is used as the two-way valve device. Pressure fuel injection system.