JP2018179025A - Air bypass valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bypass valve capable of preventing a hole of a piston from being blocked even in a case where air flowing therein contains sludge such as oil content, to maintain response performance for valve.SOLUTION: An air bypass valve 10 comprises: a coil casing storing a coil therein; a pilot valve part having a movable iron core inserted into the coil, and covered with the coil casing; and a piston part having a piston 16 with a hole, and incorporated into the coil casing, wherein a concave part 60 is provided at a bottom part of the piston 16, and the hole and a wall part 70 surrounding the hole are provided in the concave part 60.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an air bypass valve, and more particularly to a valve element (valve) installed in a turbocharger (supercharger) for an internal combustion engine of an automobile to release exhaust gas.

  Conventionally, an air bypass valve provided in a supercharger for an internal combustion engine of an automobile is, as disclosed in FIG. 1 of Patent Document 1, vertically moved by a piston 16 and an intake passage 33 of a valve body 11 It has the function of opening and closing the exhaust passage 34 and forms connection and shutoff of fluid in the valve body 11.

  However, when foreign matter enters from the outside of the air bypass valve 10, if foreign matter is caught between the piston 16 and the valve body 11, the sealing performance between the piston 16 and the valve body 11 may be degraded. .

Therefore, the above-mentioned problem can be solved by setting the bottom of the piston 16 as shown in FIG. 5 of Patent Document 1. That is, the edge (the outermost peripheral portion) of the bottom of the piston 16 is stepped, and the periphery of the hole 35 at the center of the piston 16 is recessed (recessed) than the edge described above.

  By making the bottom of the piston 16 in such a form, the contact form between the piston 16 and the valve body 11 becomes line contact. Therefore, even when foreign matter intrudes from the outside of the air bypass valve 10, the risk of the foreign matter being pinched between the piston 16 and the valve body 11 is reduced. As a result, the sealing performance of the air bypass valve 10 can be maintained.

Patent No. 6025006

  However, when the air flowing into the air bypass valve 10 contains sludge (sludge) such as oil, there is no risk that foreign matter is caught between the piston 16 and the valve body 11, but the sludge There has been a problem of closing the sixteen holes 35.

  In the case where the air flowing in the air bypass valve 10 contains fine sludge together with oil, it can pass through the hole 35 of the piston 16 in a short period of time. However, the oil in the air gradually adheres and accumulates around the hole 35 of the piston 16 as the air bypass valve 10 is used for a while. As a result, there is a problem that the hole 35 of the piston 16 is closed. When the hole 35 of the piston 16 is closed, the amount of air flowing in the air bypass valve 10 decreases, and the response performance as a valve decreases.

  Therefore, the present invention has been made to solve the above-mentioned problems. That is, according to the present invention, even if the air flowing into the air bypass valve contains oil and sludge, the air bypass valve can prevent the closing of the piston hole and maintain the response performance as the valve. Intended to provide.

  In order to solve the above problems, an air bypass valve according to the present invention includes a coil casing in which a coil is accommodated, and a pilot valve including a movable iron core inserted in the coil and covered by the coil casing. The valve is mainly composed of a part and a piston part having a hole and fitted in the coil casing. In addition, the piston portion has the piston, a first spring housed in the piston, and a piston casing that covers the outer periphery of the piston and has a hole.

Further, the pilot valve portion is inserted into the coil in which a copper wire is wound around a hollow cylindrical bobbin, the fixed iron core inserted into one end of the inner diameter portion of the coil, and the other end side of the inner diameter portion of the coil A movable iron core having a recess in the part, a yoke inserted in a gap between the inner diameter of the coil and the movable iron core, a second spring accommodated in the recess on one end of the movable iron core, and the other end of the movable iron core A steel ball housed in the recess of the housing, a valve seat disposed to face the other end of the movable iron core, and a seat holder having a through hole and housing the valve seat and the steel ball therein. doing.

Then, a projection is provided on the edge of the hole portion of the above-mentioned piston casing, a seal member is provided between the piston and the piston casing, and the seal member is fixed by the sheet holder. According to the present invention, the bottom of this piston is provided with a recess (is recessed toward the back side), and the recess is provided with a hole and a wall surrounding the opening of the hole. Features of the air bypass valve. Also, in the recess of the piston, a parallel portion perpendicular to the axial direction of the hole may be provided around the wall.

Furthermore, when the tip (opposite to the bottom) of the piston constituting the air bypass valve has an edge shape, when the piston strokes to the top dead center, the piston is divided by the piston and the piston strokes Response performance may be degraded. Therefore, the air bypass valve of the present invention may be provided with a notch at the edge of the tip of the piston.

  In the air bypass valve of the present invention, as described above, the recess is provided in the bottom of the piston, and the recess is provided with a hole through which fluid flows in and out, and a wall is provided around the opening of the hole. By this structure, even when the air flowing into the air bypass valve contains oil and sludge, the sludge is preferentially attached to the wall having a large contact area. Therefore, it is possible to reduce the adhesion and accumulation of the sludge in the hole of the piston. As a result, even when the air flowing into the air bypass valve contains sludge, the hole of the piston is prevented from being blocked, and the response performance as the valve can be maintained.

It is a longitudinal cross-sectional view which shows schematic structure of the air bypass valve 10 which concerns on embodiment of this invention. It is an expanded sectional view of piston 16 shown in FIG. It is a perspective view at the time of seeing from the piston 16 side of the air bypass valve 10 shown in FIG. FIG. 5 is a perspective view of the piston 16 shown in FIGS. 1 to 3 as viewed from the bottom side. FIG. 5 is a perspective view of the piston 16 shown in FIGS. 1 to 3 as viewed from the tip end side.

  Hereinafter, an air bypass valve according to an embodiment of the present invention will be described in detail with reference to the attached drawings. FIG. 1 is a longitudinal sectional view showing a schematic structure of an air bypass valve 10 according to an embodiment of the present invention. As shown in FIG. 1, the air bypass valve 10 includes a coil casing 12 accommodating a coil 25 therein, and a pilot valve portion 13 provided with a movable iron core (plunger) 27 inserted in the cylindrical coil 25. And a piston portion 14 having a bottomed piston 16 having a hole 35 and fitted in the above-described coil casing 12 as a main component.

  First, the configuration of the pilot valve unit 13 will be described. The pilot valve portion 13 is covered by the coil casing 12 and is formed around the coil 25. The coil 25 is a component in which a copper wire is wound around a hollow cylindrical bobbin 24 having a collar at both ends. A part of the fixed core 23 is inserted into the inner diameter portion of the coil 25, that is, one end side of the inner diameter portion of the bobbin 24. A part of the movable iron core 27 is inserted into the other end side of the inner diameter portion of the bobbin 24. The fixed core 23 has a collar and a substantially U-shaped cross section. Moreover, the movable iron core 27 is a shape provided with the recessed part in the both ends. The yoke 26 is inserted into the gap between the inner diameter portion of the bobbin 24 and the movable iron core 27.

A second spring 28 is accommodated in the recess on one end side of the movable core 27, and the second spring 28 is pressed at the end of the fixed core 23. Further, as described above, another concave portion 36 is provided on the other end side of the movable iron core 27 (the opposite side to the concave portion in which the second spring 28 is accommodated). A valve seat 30 having a through hole 38 is disposed at a position facing the other recess 36. The steel ball 31 is sandwiched from both sides by the recess 36 provided on the other end side of the movable core 27 and the through hole 38 of the valve seat 30.

  As described above, the valve seat 30 is provided with the through hole 38 connected to the through hole 37 formed in the seat holder 29 described later. The steel ball 31 functions as a seal member of the pilot valve portion 13. Therefore, the steel ball 31 is inserted into the recess 36 formed on one end side of the movable core 27 and then integrated with the movable iron core 27 by press-fitting or caulking so that the steel ball 31 does not fall off. The seal shape of the valve seat 30 is formed to have a conical or hemispherical cross section, and the contact portion between the spherical surface of the steel ball 31 and the inner circumferential surface of the valve seat 30 becomes linear. Therefore, the contact portion between the steel ball 31 and the valve seat 30 has a good sealing performance and is effective against the entry of foreign matter.

Further, the valve seat 30, the steel ball 31, and part of the movable iron core 27 are accommodated in a seat holder 29 provided with a recess. The sheet holder 29 is provided with a first drain port 18 branched from the concave portion, and the first drain port 18 is further connected to a second drain port 22 and finally the air It is connected to the outside of the bypass valve 10. The ratio of the diameter of the through hole 38 formed in the valve seat 30 to the diameter of the steel ball 31 is preferably set in the range of 0.5 to 0.75.

Next, the configuration of the piston portion 14 will be described. The piston portion 14 is formed around a bottomed piston 16 having a hole 35. A piston casing 15 covering the outer periphery of the piston 16 and the above-described sheet holder 29 are joined and integrated with the inner circumferential surface of the coil casing 12 in an integrated state. Further, in a piston chamber 39 which is an inside of the piston 16, a first spring 19 is accommodated. Thereby, the through hole 37 of the seat holder 29, the piston chamber 39, and the hole 35 of the piston 16 are spatially connected to each other.

FIG. 2 is an enlarged sectional view of the piston 16 shown in FIG. At the center of the recess 60 provided at the bottom of the piston 16, a hole 35 for spatially connecting the outside of the air bypass valve 10 and the piston chamber 39 is provided as shown in FIG. A first flat portion 81, a wall 70, a second flat portion 82, a first inclined portion 91, and a third flat portion 83, which will be described later, are continuous in order so as to expand from the inside to the outside of the recess 60 around the hole 35. It is formed. The height (length in the axial direction of the piston 16) of the wall portion 70 is formed so as to entirely fit in the recess 60. Further, the first flat portion 81, the second flat portion 82 and the third flat portion 83 are all perpendicular to the axial direction of the hole 35 of the piston 16 (the movable direction of the piston 16).

FIG. 3 is a perspective view of the air bypass valve 10 shown in FIG. 1 as viewed from the piston 16 side. The piston 16 is fitted inside the piston casing 15 as shown in FIG. 3, and can freely move along the piston casing 15 in the direction of the double-ended arrow shown in FIG. The piston 16 is guided by a projection 21 formed on the edge of the hole of the piston casing 15.

As shown in FIG. 3, a plurality of, at least three or more, projections 21 are provided in the circumferential direction of the edge of the hole of the piston casing 15. With this structure, it is possible to prevent the sliding failure and the misalignment of the piston 16 and maintain the response performance as a valve. The inner side of the projection 21 can be formed in an R shape in order to reduce the sliding resistance on the inner diameter side in contact with the piston 16 side.

  A perspective view of the piston 16 shown in FIGS. 1 to 3 as viewed from the bottom side is shown in FIG. As shown in FIG. 4, the first flat portion 81 is continuously formed around the opening of the hole 35. A wall 70 is formed on the outside of the first flat portion 81 so as to surround the periphery of the hole 35. The second flat portion 82, the first inclined portion 91, and the third flat portion 83 are sequentially formed on the outer side of the wall 70 toward the edge of the piston 16 in this order.

By providing the first flat portion 81 around the opening of the hole 35 in the recess 60 at the bottom of the piston 16 and the wall 70 around it, sludge in the air flowing in and out of the inside of the air bypass valve 1 etc. Reduces the direct entry of foreign matter.

  Further, by forming the second flat surface portion 82 and the first inclined portion 91 on the outer peripheral portion of the wall portion 70, when the air bypass valve 1 is disposed with the hole 35 directed upward or to the side, the air bypass valve The sludge in the air flowing in and out of the inside of 1 can be finally collected and stored in the second flat portion 82 along the first inclined portion 91.

Furthermore, by providing the third flat surface portion 83 at the outermost peripheral portion in the recess 60 of the piston 16, it is also possible to mount a component such as a filter on the bottom of the piston 16 (inside the recess 60). Moreover, by making the edge of the bottom part of piston 16 shown in FIG. 3 and FIG. 4 into level difference 16b, when piston 16 and valve case 11 contact, the contact form will be line contact. As a result, the risk of inserting foreign matter at the contact portions is reduced, and the above-mentioned sealing performance can be maintained.

  FIG. 5 shows a perspective view of the piston 16 shown in FIGS. 1 and 3 as viewed from the top (tip side). As shown in FIG. 5, notches 16 d may be provided at a plurality of locations in the radial direction of the piston 16 at the edge of the tip end portion (the upper portion on the sheet of FIG. 5) of the piston 16.

By this structure, even when the piston 16 of the air bypass valve 10 ends its stroke (in the state where the piston 16 shown in FIG. 1 has moved to the uppermost position on the drawing), inside and outside the piston chamber 39 via the notch 16d. Since the gas (fluid) can flow in and out, it is possible to prevent a delay in response performance as a valve.

  Further, as shown in FIG. 5, by providing two notches 16d in the radial direction of the piston 16 with a predetermined distance (interval) therebetween, the claws 16c are formed between the two notches 16d and 16d. It can also be done. By forming the claw portion 16c on the edge of the tip end portion of the piston 16, the piston 16 can be fitted into the piston casing 15 with one touch (one step), so the assembly process of the air bypass valve 10 is simplified. .

  Basically, the air bypass valve 10 according to the present embodiment is configured as described above. Next, the operation of the air bypass valve 10 will be described. When the pilot valve portion 13 of the air bypass valve 10 is energized from an external power source, the movable core (plunger) 27 moves upward on the paper surface of FIG. 1 by the electromagnetic force generated in the coil 25. When the movable core 27 moves upward, the steel ball 31 fitted into the recess 36 of the movable core 27 separates from the valve seat 30. As a result, the piston chamber 39, the through hole 37 of the seat holder 29, and the first drain port 18 are connected to each other.

  The pressure in the piston chamber 39 is higher than the pressure in the intake passage 33 of the valve body 11, and the gas in the piston chamber 39 is inhaled from the valve body 11 via the first drain port 18 and the second drain port 22. It is discharged to the passage 33. At this time, the gas in the exhaust passage 34 of the valve body 11 flows into the piston chamber 39 through the hole 35 of the piston 16.

The air bypass valve 10 of the present invention is designed such that the area in which the pilot valve portion 13 defined by the stroke of the movable iron core 27 and the through hole 38 of the valve seat 30 is larger than the cross sectional area of the hole 35 of the piston 16 It has become. Therefore, the amount of gas flowing out from the piston chamber 39 into the intake passage 33 side of the valve body 11 is greater than the amount of gas flowing from the exhaust passage 34 side of the valve body 11 into the piston chamber 39 through the hole 35. There will be more.

  Therefore, the pressure in the piston chamber 39 is reduced, and the pressure difference in the piston chamber 39 and the exhaust passage 34 of the valve body 11 generates a force upward of the piston 16. Therefore, when the piston 16 is separated from the valve body 11, the exhaust passage 34 and the intake passage 33 of the valve body 11 are spatially connected.

  On the other hand, when the pilot valve portion 13 is not energized, the electromagnetic force of the pilot valve portion 13 disappears (disappears), and the movable iron core 27 is shown in FIG. 1 by the elastic force of the second spring 28. Moving downward, the steel ball 31 integrated with the movable core 27 comes into contact with the valve seat 30. Thus, the piston chamber 39 and the first drain port 18 are shut off.

  As a result, the gas in the exhaust passage 34 of the valve body 11 flows into the piston chamber 39 through the hole 35 of the piston 16 and the pressure in the exhaust passage 34 and the pressure in the piston chamber 39 become the same. As a result, the piston 16 moves to the lower position in the drawing as shown in FIG. 1 by the elastic force of the first spring 19, and the bottom surface of the piston 16 contacts the valve case 11.

Reference Signs List 10 air bypass valve 11 valve body 12 coil casing 13 pilot valve portion 14 piston portion 15 piston casing 16 piston 16 d piston 16 notched 18 first drain port 19 first spring 21 protrusion 22 second drain port 23 fixed iron core 24 bobbin 25 coil 26 yoke 27 movable iron core (plunger)
28 second spring 29 seat holder 30 valve seat 31 steel ball 33 intake passage of the valve body 11 exhaust passage 35 of the valve body 11 hole of the piston 16 recess of the movable iron core 37 through hole of the seat holder 29 valve seat 30 Through hole 39 piston chamber 52 seal member 60 recess of piston 16 wall portion in recess 60 of piston 16 first parallel portion in recess 60 of piston 16 second parallel portion in recess 60 of piston 16 piston 83 Third parallel portion 91 in the recess 60 of 16 and first inclined portion in the recess 60 of the piston 16

Claims (3)

A coil casing in which a coil is accommodated;
A pilot valve having a movable core inserted in the coil and covered by the coil casing;
A piston portion having a hole at the bottom and being fitted into the coil casing;
An air bypass valve formed from
The piston unit is
Said piston,
A first spring housed within the piston;
A piston casing having a hole covering an outer periphery of the piston;
And have
The pilot valve portion is
The coil in which a copper wire is wound around a hollow cylindrical bobbin;
A fixed core inserted into one end of the inner diameter portion of the coil;
The movable iron core inserted into the other end of the inner diameter portion of the coil and having a recess at both ends;
A yoke inserted into a gap between an inner diameter portion of the coil and the movable core;
A second spring housed in a recess on one end side of the movable core;
A steel ball housed in a recess on the other end side of the movable core;
A valve seat disposed to face the other end side of the movable core;
A seat holder having a through hole and accommodating the valve seat and the steel ball therein;
And have
A protrusion is provided on the edge of the hole of the piston casing, and a seal member is provided between the piston and the piston casing, and the seal member is fixed by the sheet holder. At the valve
The bottom of the piston is provided with a recess,
In the recess, the hole and
A wall surrounding the opening of the hole;
An air bypass valve characterized by comprising. In the recess of the piston,
The air bypass valve according to claim 1, wherein a parallel portion perpendicular to an axial direction of the hole is provided around the wall portion. The air bypass valve according to claim 1 or 2, wherein a notch is provided at an edge of a tip of the piston.

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