JP2001004059A - Flow control valve - Google Patents

Abstract

(57) [Problem] To provide a flow path control valve capable of reliably maintaining a closed state with a simple configuration. SOLUTION: A valve body 27 which is provided so as to be able to contact and separate from a valve seat 22 by moving a valve shaft 26, and biases the valve shaft 26 with a predetermined force in a direction in which the valve body 27 comes into contact with the valve seat 22. Spring 2
9, a movable iron core 39 that moves coaxially with the valve shaft 26 and is disposed so as to be able to contact and separate from the valve shaft 26, and attracts the movable iron core 39 so that the movable iron core 39 contacts the valve shaft 26 and 26 against the predetermined force of the spring 29
A first electromagnet 38 that moves in a direction away from the valve seat 22, and a second electromagnet 4 that attracts the movable iron core 39 and separates from the valve shaft 26 while the valve body 27 is in contact with the valve seat 22.
4 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EG for recirculating a part of exhaust gas of, for example, an engine of an automobile to an intake system.
The present invention relates to a flow control valve applied to an R (Exhaust Gas Recirculation) device.

[0002]

2. Description of the Related Art Generally, an EGR device extracts a part of exhaust gas flowing through an exhaust passage 1 into a bypass passage 2 as shown in FIG. 5, and a flow control valve 3 connected to the bypass passage 2. This is a system in which exhaust gas is recirculated in the intake passage 4 while controlling the amount of exhaust gas in accordance with the operation state, thereby lowering the maximum temperature during combustion and reducing NOx. When the above-described flow control valve 3 is mounted on an actual vehicle, the valve receives a large pressure differential pressure due to vibration of the vehicle body, exhaust pulsation, and the like. In this case, it is required that the flow control valve 3 connected to the bypass passage 2 connecting the exhaust side and the intake side be reliably closed in order to prevent a decrease in combustion efficiency.

FIG. 6 is a sectional view showing the structure of a conventional flow control valve disclosed in, for example, Japanese Patent Application Laid-Open No. 56-35877. The upper and lower halves of FIG. Indicates the status. In the drawing, reference numeral 5 denotes a first and second discharge ports 5 connected to the suction port 5a on one end side and the suction port 5a on the other end side via valve holes 5b and 5c, respectively.
d and 5e are formed in the valve body.
5d is connected to an exhaust path (not shown) through the second discharge port 5d.
e is connected to an intake path (not shown), respectively. 6
Is fixed to one side of the valve body 5, a fixed core 6a, an electromagnetic coil 6b wound around the fixed core 6a, and fixed to the other end of a valve shaft to be described later, and can be attracted to the fixed core 6a. This is an electromagnet composed of a movable iron core 6c.

A valve shaft 7 penetrates through the center of the fixed iron core 6a so as to be slidable, and has one end extending into both the valve holes 5b and 5c of the valve body 5; A valve element 9 fixed to the other end and alternately closing the valve holes 5b and 5c with the movement of the valve shaft 7 is disposed on the other side of the valve body 5 and fixed to the other end of the valve shaft 7. In addition, a bellows forming an empty space 9a therein is configured such that, although not shown, external air is controlled by a solenoid valve or the like and is pressure-fed into the empty space 9a. Reference numeral 10 denotes a first compression spring which is disposed in the empty space 9a of the bellows 9 and urges the bellows 9 in a direction in which the bellows 9 extends. Reference numeral 11 denotes a first compression spring which is disposed between the bellows 9 and the valve body 8 and extends in a direction away from the both. This is a second compression spring that is biased.

Next, the operation of the flow control valve configured as described above will be described with reference to the drawings. First, EG
When the R device is in operation, the electromagnetic coil 6b of the electromagnet 6
, The movable core 6c is attracted to the fixed core 6a and moves as shown in the lower half of the figure. Then
With this movement, the valve shaft 7 moves to the left in the drawing, and the valve element 8 closes the valve hole 5b and opens the valve hole 5c. When the valve hole 5c is opened, the exhaust gas flowing from the exhaust passage (not shown) flowing from the suction port 5a flows out to the second discharge port 5e through the valve hole 5c, and the intake passage ( (Not shown).

Next, when the EGR device is in an inactive state,
When the energization of the electromagnetic coil 6b of the electromagnet 6 is stopped, as shown in the upper half of FIG.
, The valve shaft 7 is moved rightward in the figure by the urging forces of the first and second compression springs 10 and 11, and the valve body 8 is in the opposite state to the above-described operation state. Valve hole 5
c is closed and the valve hole 5b is opened. When the valve hole 5c is closed, the recirculation of the exhaust gas is stopped, and the exhaust gas flowing in from the intake port 5a passes through the valve hole 5b.
It flows out to the first discharge port 5d side and is discharged to a discharge path (not shown). On the other hand, this inoperative state, that is, the valve body 8
In order to reliably maintain the state in which the valve hole 5c is closed, external air is pressure-fed into the vacant space 9a of the bellows 9 by the control of, for example, a solenoid valve (not shown).
The valve body 8 is pressed by the urging force of the compression spring 10.

[0007]

The conventional flow control valve is constructed as described above, and the heavy movable iron core 6c is integrated with the valve shaft 7, so that the valve body is affected by the vibration of the vehicle body due to its influence. When the EGR device is in a non-operating state, external air is pressure-fed into the vacant space 9a of the bellows 9 by the control of a solenoid valve or the like, and the first compression spring 10 Of the valve body 8 to prevent the valve body 8 from being damaged and the combustion efficiency from lowering, so that the electric power for controlling the solenoid valve is reduced. There has been a problem that facilities such as circuits and air piping are complicated and expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an inexpensive flow control valve capable of reliably maintaining a closed state of a valve with a simple structure. It is assumed that.

[0009]

According to a first aspect of the present invention, there is provided a flow control valve, wherein a valve body is provided so as to be able to come into contact with and separate from a valve seat by moving a valve shaft. A spring that urges with a predetermined force in the direction in which it comes into contact with the valve shaft, a movable core that moves coaxially with the valve shaft and is disposed so as to be able to contact and separate from the valve shaft, and attracts the movable core to the valve shaft by sucking the movable core. And a first electromagnet for moving the valve shaft in a direction in which the valve body separates from the valve seat against the predetermined force of the spring, and attracts the movable iron core while the valve body is in contact with the valve seat. And a second electromagnet to be separated from the valve shaft.

A flow control valve according to a second aspect of the present invention is the flow control valve according to the first aspect, wherein a bearing member for imparting frictional resistance to a sliding portion between the valve shaft and the movable iron core is provided.

A third aspect of the present invention provides a flow control valve according to the first aspect, wherein a viscous member is applied to a sliding portion of the valve shaft and the movable iron core.

According to a fourth aspect of the present invention, there is provided a flow control valve according to the first aspect, further comprising an auxiliary spring which constantly urges the movable iron core in a direction in which the movable iron core is attracted by the first electromagnet.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a cross-sectional view showing a configuration of a flow control valve in a closed state according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view showing a configuration of an open state of a flow control valve in FIG. 1, and FIGS. 2 is a cross-sectional view showing a configuration of a main part of a flow control valve in FIG. 2, and FIG. 4 is a cross-sectional view showing a configuration of a main part of the flow control valve in FIGS. 1 and 2 which is different from FIG.

In the figure, reference numeral 21 denotes a valve case formed by, for example, aluminum die casting or the like.
1a is formed, and a first flow path 23 connected to an intake path (not shown) and an exhaust path (not shown) are formed vertically above and below a valve seat 22 provided thereunder. Second flow paths 24 to be connected are respectively formed. Reference numeral 25 denotes a guide bush arranged so as to close the through hole 21a of the valve case 21. As shown in FIG. 26 is the guide bush 2
5 is a valve shaft which can be slid through airtightly.
6 is a valve body that is attached to one end side of the valve body 6 and opens and closes the first and second flow paths 23 and 24 by coming into contact with and separating from the valve seat 22.

Numeral 28 denotes a dish-shaped member fixed to the other end of the valve shaft 26, and 29 urges the outer edge of the dish-shaped member 28 with a predetermined force in a direction to bring the valve body 27 into contact with the valve seat 22. The spring 30 is a bearing member made of, for example, an O-ring embedded in the concave portion 25a of the guide bush 25. The spring 30 is crushed when its upper portion is pressed by the pressing plate 31, and imparts a predetermined frictional resistance to the valve shaft 26. These are the first bearing members.
The valve part 32 is constituted by the parts 31 through 31.

Reference numeral 33 denotes a fixed iron core seated on the upper part of the valve case 21.
4A, a through hole 33a is formed coaxially with FIG.
As shown in FIG. 7, a recess 33b is formed in the through hole 33a. Reference numeral 34 denotes, for example, 0 embedded in the concave portion 33b.
A bearing member formed of a ring or the like is crushed by being pressed by a holding plate 35 to provide a predetermined frictional resistance to a movable core shaft, which will be described later. An electromagnetic coil 46 wound around the casing is formed with a lower portion sandwiched between the valve case 21 and the fixed iron core 33 and formed so as to cover the periphery of the electromagnetic coil 36. Constitute the first electromagnet 38.

Numeral 39 is coaxial with the valve shaft 26 and is movably disposed by being attracted to the fixed iron core 33. The distal end 39 extends through the through hole 33a of the fixed iron core 33 at the tip, and extends through the dish-shaped member 28. The movable iron core 40, in which a movable iron core shaft 39a that can be brought into contact with and separated from the valve shaft 26 is fixedly integrated, is coated on an outer peripheral sliding portion of the movable iron core 39 to give a predetermined viscous resistance to the movable iron core 39, for example. A viscous member made of grease or the like, 41 is a fixed iron core provided on the side opposite to the fixed iron core 33 of the first electromagnet 38 so as to be able to attract the movable iron core 39, and 42 is an insulating bobbin 43 on the upper part of the fixed iron core 41. The wound electromagnetic coil 47 is a magnetic path member formed so as to cover the upper part and the inner peripheral side of the electromagnetic coil 42.
, And is controlled to operate while the first electromagnet 38 is not operating. Reference numeral 45 denotes an auxiliary spring that constantly urges the movable iron core 39 with a predetermined force in a direction attracted by the first electromagnet 38.

Next, the operation of the flow control valve according to the first embodiment of the present invention configured as described above will be described with reference to the drawings. First, when the EGR device is in operation, when the electromagnetic coil 36 is energized, the fixed iron core 33,
A magnetic path is formed by the casing 46 and the fixed core 41, and the first electromagnet 38 operates to move the movable core 39 as shown in FIG.
Is attracted to the fixed iron core 33 and moves downward in the figure. After the tip of the movable iron core shaft 39a contacts the dish-shaped member 28, it overcomes the urging force of the spring 29 and moves the valve shaft 26 further downward. Then, the valve body 27 separates from the valve seat 22 and the first and second flow paths 23 and 24 communicate with each other, and the exhaust gas from the exhaust path (not shown) flows to the intake path (not shown). Recirculated.

Next, when the EGR device is in a non-operating state, the power supply to the electromagnetic coil 36 is stopped, and when power is supplied to the electromagnetic coil 42, the magnetic force is applied by the fixed iron core 41, the housing 46, and the magnetic path member 47. A path is formed and the second electromagnet 44 operates to move the movable core 39 to the fixed core 41 and move upward in the figure as shown in FIG. Then, with this movement, the dish-shaped member 28 also moves upward together with the valve shaft 26 by the urging force of the spring 28, and at a position where the valve body 27 attached to one end of the valve shaft 26 abuts on the valve seat 22. Stop,
The first and second flow paths 23 and 24 are shut off. on the other hand,
The movable iron core 39 moves slightly upward, and the movable iron core shaft 3
At the position where the tip of 9a is away from the dish-shaped member 28,
It is stopped by being abutted and adsorbed on 1.

As described above, according to the first embodiment, E
When the GR device is not operated, that is, in a state where the valve body 27 is in contact with the valve seat 22 and is closed, the second electromagnet 44 is operated to cause the movable core 39 to be attracted to the fixed core 41, so that the movable core Since the tip of the shaft 39a is separated from the dish-shaped member 28, the valve shaft 26 is completely separated from the movable iron core 39 and the like, and only the valve body 27 is attached. Therefore, it is possible to reliably maintain the closing of the valve body 27 with a simple configuration, prevent a decrease in combustion efficiency, and provide an inexpensive flow control valve.

Further, bearing members 30 and 34 are provided on sliding portions of the valve shaft 26 and the movable core shaft 39a so as to impart a predetermined frictional resistance. 26, 39a to prevent malfunction,
The closure of the valve body 27 can be maintained more reliably. Further, since the viscous member 40 is applied to the outer peripheral sliding portion of the movable iron core 39 to impart viscous resistance, malfunction of the movable iron core 39 is prevented, and the closing of the valve body 27 is more reliably performed as described above. Can be maintained. Furthermore,
Since the movable iron core 39 is always urged by the auxiliary spring 45 in the direction in which it is attracted by the first electromagnet 38, the electric capacity of the first electromagnet 38 can be reduced by that amount and energy can be saved. Become.

In the first embodiment, the flow control valve applied to the EGR device has been described. However, the present invention is not limited to this, and it goes without saying that the flow control valve can be applied to other devices.

[0023]

As described above, according to the first aspect of the present invention, the valve element is provided so as to be able to come into contact with and separate from the valve seat by the movement of the valve axis. A spring that urges with a predetermined force in the direction of movement, a movable core that moves coaxially with the valve shaft and is disposed so as to be able to contact and separate from the valve shaft, and contacts the movable core with the valve shaft by sucking the movable core A first electromagnet for moving the valve stem in a direction in which the valve body is disengaged from the valve seat against a predetermined force of the spring; and a valve for attracting the movable iron core while the valve body is in contact with the valve seat. The provision of the second electromagnet detached from the shaft makes it possible to provide an inexpensive flow control valve capable of reliably maintaining the closed state of the valve with a simple configuration.

According to a second aspect of the present invention, in the first aspect, a bearing member for providing frictional resistance to a sliding portion between the valve shaft and the movable iron core is provided, so that the valve shaft and the movable iron core are provided. Can provide a flow control valve capable of preventing the malfunction of the valve and maintaining the closed state of the valve more reliably.

According to the third aspect of the present invention, in the first aspect, since the viscous member is applied to the sliding portion of the valve shaft and the movable core, malfunction of the valve shaft and the movable core is prevented by viscous resistance. Thus, it is possible to provide a flow control valve capable of more reliably maintaining the closed state of the valve.

According to a fourth aspect of the present invention, in the first aspect, an auxiliary spring for constantly biasing the movable iron core in a direction attracted by the first electromagnet is provided.
Thus, it is possible to provide a flow control valve capable of reducing the electric capacity of the electromagnet and saving energy.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a flow control valve in a closed state according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view showing a configuration of the flow control valve in FIG. 1 in an open state.

FIG. 3 is a cross-sectional view showing a configuration of a main part of the flow control valve in FIGS. 1 and 2;

FIG. 4 is a cross-sectional view showing a configuration of a main part of the flow control valve in FIGS. 1 and 2 which is different from FIG. 3;

FIG. 5 is a system diagram showing a general concept of an EGR device.

FIG. 6 is a cross-sectional view showing a configuration of a conventional flow control valve.

[Explanation of symbols]

22 valve seat, 23 first flow path, 24 second flow path, 2
6 Valve shaft, 27 valve body, 29 spring, 30, 34
Bearing member, 38 first electromagnet, 39 movable iron core, 4
0 viscous member, 44 second electromagnet, 45 auxiliary spring.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshihiko Miyake 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Within Mitsubishi Electric Corporation (72) Inventor Yoichi Fujita 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F term in Ryo Denki Co., Ltd. (reference) 3H106 DA07 DA13 DA25 DB02 DB12 DB23 DB32 DC02 DC17 DD03 EE48 FA08 FB43 KK19

Claims (4)

[Claims] A valve body disposed so as to be able to contact and separate from a valve seat by moving a valve shaft; and a spring for urging the valve shaft with a predetermined force in a direction in which the valve body contacts the valve seat. A movable core that moves coaxially with the valve shaft and is disposed so as to be able to contact and separate from the valve shaft, and causes the movable core to contact the valve shaft by sucking the movable core, and A first electromagnet for moving the valve body in a direction to separate from the valve seat against a predetermined force of a spring, and attracting the movable iron core while the valve body is in contact with the valve seat, A flow control valve, comprising: a second electromagnet that is detached from the valve shaft. 2. The flow control valve according to claim 1, wherein a bearing member for providing frictional resistance is disposed on a sliding portion between the valve shaft and the movable iron core. 3. The flow control valve according to claim 1, wherein a viscous member is applied to a sliding portion between the valve shaft and the movable iron core. 4. The flow control valve according to claim 1, further comprising an auxiliary spring that constantly urges the movable iron core in a direction attracted by the first electromagnet.