JP6090605B2 - Air bypass valve - Google Patents

Description

  The present invention relates to an air bypass valve, and more particularly to a supercharging pressure relief valve for an automobile turbocharger.

  Conventionally, this type of air bypass valve is disposed in the bypass passage 8 between the pressure side 12 of the supercharger (shown by the reference described in Patent Document 1. The same applies hereinafter) and the suction side 14. A control device for an internal combustion engine, which includes a solenoid valve 4, a bypass valve 2 having a pneumatically operable valve closing body 10, and a control pressure chamber 24. There is known a control device for an internal combustion engine in which a fluid connection can be formed via a control pressure chamber 24 between the pressure side 12 and the suction side 14 of the supercharging device during the opening process of the bypass valve 2 by power supply. (For example, refer to Patent Document 1).

Special table 2013-530358 gazette

However, in Patent Document 1, foreign matter may enter the bypass valve from the bypass valve inlet, block the throttle hole, cause deterioration of piston slidability, and seal member seal failure. In addition, the guide length of the valve closing body (= piston) is insufficient, resulting in poor piston closing due to misalignment and poor sealing due to coaxial displacement with the seal member.
In addition, because the valve closing body of the solenoid valve is resin, it deforms in a high-temperature environment, resulting in poor sealing, the valve closing body of the solenoid valve is in the opposite direction to the piston, the volume of the control pressure chamber is large, Change is slow and response is slow.
Further, the piston tip has an edge shape, it is difficult to assemble the seal member, the piston collar is cylindrical, and the control pressure chamber is separated by the piston at the end of the piston stroke, resulting in poor response.

Furthermore, oil is contained in the air under the usage environment. Therefore, there is a problem that oil contained in the pressure side adheres to the piston (10), the oil is transmitted to the bottom surface of the piston, and the compensation opening (throttle) 36 is clogged to cause a malfunction.
Further, the valve closing body 10 and the electromagnetic valve casing 28 are sealed by a seal member (packing) 40. Since the linear expansion coefficient of the seal member 40 is larger than that of the solenoid valve casing 28, the solenoid valve casing 28 swells at a high temperature, for example, 220 ° C., and the seal member 40 tries to swell further. The seal is maintained by copying. However, due to the high temperature, the outer diameter of the seal member 40 is creep-deformed in accordance with the inner diameter of the solenoid valve casing 28.
Therefore, when the temperature returns from high temperature to room temperature, the difference in linear expansion coefficient between the solenoid valve casing 28 and the seal member 40 causes a difference between the contraction amount of the outer diameter of the seal member 40 and the contraction amount of the solenoid valve casing 28. ,
A gap is generated between the solenoid valve casing 28 and the seal member 40, thereby increasing air leakage from between the solenoid valve casing 28 and the seal member 40 and lowering the performance.
The present invention has been made to solve the above problems, and foreign matter enters the inside of the valve, blocks the throttle hole, deteriorates the sliding property of the piston due to insufficient guide length, seal failure of the sealing element, and responsiveness. An object of the present invention is to provide an air bypass valve that prevents the deterioration.
Furthermore, the present invention has been made to solve the above-described problem. By projecting the shape around the throttle hole formed in the piston, the structure allows the oil transmitted from the piston surface to hardly enter the throttle hole. An object of the present invention is to provide an air bypass valve that prevents clogging of holes.
The present invention also prevents air leakage by sandwiching the upper and lower surfaces of the packing outer diameter side with the casing and piston casing, which are mating members, to prevent air leakage due to the difference in heat shrinkage between the packing and the piston casing even if the temperature changes. An object is to provide a bypass valve.

The invention for solving the above-mentioned problems is
A convex valve casing attached to the valve body;
A piston portion fitted into the large inner diameter portion of the valve body;
A pilot valve part engaged with the piston part,
The piston portion includes a stepped cylindrical piston casing fitted on the inner peripheral surface of the valve body, a stepped cylindrical piston having a bottom surface that is the innermost diameter surface of the piston casing, and the piston. A cylindrical piston that is fitted into the innermost diameter surface of the casing and has a bottom surface, a throttle that is drilled in the piston and communicates with the supercharger discharge side of the valve body, and is attached to the inner diameter portion of the piston casing A sealing member that contacts the nectar on the outer peripheral surface of the piston, a casing having a concave-convex shape that is housed in a large inner diameter portion of the piston casing and is engaged with the upper surface of the piston casing and the valve casing;
A first spring member mounted on a convex outer peripheral portion of the casing and mounted in an inner peripheral hole of the piston, and the pilot valve portion is mounted on the valve main body and integrated with the valve main body. A fixed iron core having a U-shaped cross-section, a bobbin fitted on the outer peripheral surface of the fixed iron core, a coil around which the bobbin is wound, and a yoke fitted into the inner diameter part of the coil, A movable core inserted into the inner peripheral surface of the yoke; a second spring member fitted into a substantially axial core of the movable core and having an upper end engaged with the lower surface of the fixed core;
A seat holder that is in contact with the lower surface of the yoke and slidably engages with the inner diameter hole of the casing; a valve seat that is fitted to the seat holder; and a ball member that is secured to the recess of the movable iron core. Formed from,
The piston casing is provided with at least three protrusions for guiding the outer peripheral surface of the piston in a circumferential direction in a small diameter portion, oriented in the longitudinal direction of the piston;
It is characterized by.
According to the present invention, the guide length of the piston can be secured, the radial opening area at the time of opening the piston can be secured while preventing the deterioration of the slidability, and the valve flow rate can be secured. It is possible to prevent poor sealing of elements.

Providing at least one radial groove at the upper end of the piston is preferable because it prevents a delay in response to closing from the piston stroke end during operation.
Furthermore, it is preferable to provide a taper shape at the rear end of the piston because the assembling property of the seal member is improved.

  By mounting at least one filter on the lower surface of the piston or the lower surface of the valve seat and the seat holder, foreign matter and dust can be prevented from entering the throttle of the piston portion and the pilot valve portion. Can be prevented.

  Further, it is preferable that the valve seat of the pilot valve portion is positioned on the piston side, and the ON response and the OFF response are improved by reducing the volume of the piston chamber.

  Further, since the diaphragm is formed in the shape of protrusions at both ends in the axial direction, the oil transmitted from the surface of the piston is difficult to enter, and clogging of the diaphragm can be prevented.

  Furthermore, since the seal member has an L-shaped cross section, the inner side is in contact with the outer peripheral surface of the piston, and the upper and lower surfaces are sandwiched between the piston casing and the casing. It is possible to prevent air leakage from the outer diameter side of the packing due to the difference in heat shrinkability.

The present invention can secure the guide length of the piston, secure the valve flow rate by securing the opening area in the radial direction when the piston is opened while preventing deterioration of the slidability, and further, the seal due to the misalignment of the piston due to insufficient guide length It is possible to prevent a sealing failure of the element.
Furthermore, the volume of the piston chamber can be reduced by positioning the valve seat of the pilot valve portion on the piston side.
In addition, the amount of air sucked into and discharged from the piston chamber during piston stalk is reduced, and the ON response and OFF response can be improved.
Furthermore, it is possible to prevent oil from entering the throttle hole and prevent leakage of air from the outer diameter side of the packing due to thermal contraction of the packing and the piston casing even if the temperature changes.

1 is a schematic longitudinal sectional view showing a schematic structure of an air bypass valve according to a first embodiment of the present invention. It is a perspective view of the air bypass valve of FIG. It is a substantially expanded sectional view which shows the engagement state with the casing in the stroke end of the piston of FIG. It is sectional drawing which shows the engagement state of the sealing element and sealing member of the piston of FIG. It is a perspective view of the piston of FIG. It is a substantially longitudinal cross-sectional view which shows schematic structure of the air bypass valve of 2nd embodiment of this invention. FIG. 7 is an enlarged detail view of part A in FIG. 6.

Hereinafter, preferred embodiments of an air bypass valve according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
As shown in FIG. 1, an air bypass valve 10 includes a valve main body 11, a valve main body 12 mounted on the valve main body 11, a piston portion 13 built in the valve main body 12, and an upper portion of the piston portion 13. The pilot valve part 14 located is comprised as a main component.

  The piston portion 13 includes a stepped cylindrical piston casing 15 engaged with the inner peripheral surface 12 a of the valve casing 12, and a stepped cylindrical piston 16 fitted into the small inner diameter portion 15 a of the piston casing 15. The piston casing 15 has a U-shaped cross-section seal member 17 which is attached to the inner diameter portion 15b of the piston casing 15 and comes into contact with the outer peripheral surface of the piston 16, and a large inner diameter portion 15c of the piston casing 15. And a casing 18 having a concavo-convex cross section that is inserted into the upper surface and the valve casing 12.

The piston 16 is slidably supported on the small inner diameter portion 15 a of the piston casing 15, and is guided by a claw (protrusion) 21 formed on the small diameter portion 20 of the piston casing 15.
In this case, as shown in FIG. 2, the claw 21 may be provided with a plurality, preferably at least three (preferably six) in the circumferential direction of the small inner diameter portion 15a of the piston casing 15.
Further, the claw 21 is formed in an R shape on the inner diameter side in contact with the piston 16 in order to reduce sliding resistance.

Further, as shown in FIGS. 3 and 5, a flange 16c is formed at the tip of the piston 16 (the upper end in FIGS. 3 and 5), and one groove 16d is radially formed in the flange 16c. As described above, preferably two are provided to prevent a delay in response at the stroke end of the piston 16 during operation.
Further, the rear end portion (lower end portion in FIGS. 3 and 5) of the piston 16 forms a cylindrical portion smaller than the inner diameter of the seal member 17 and a taper engagement shape 16b continuous thereto, and the seal member 17 follows the taper shape 16b. And can be easily assembled.
Further, at least one throttle 35 is provided on the lower surface of the piston 16, and the piston chambers 39 and 40 are connected to the supercharger discharge side 34.

The casing 18 is fitted into the inner peripheral surface 12 a of the valve body 12 and the large inner diameter portion 15 c of the piston casing 15, and the large diameter portion 18 b of the casing 18 communicates with the piston chambers 39 and 40 through the communication hole 37. A drain port 22 is formed in one or two locations in the radial direction.
Reference numeral 19 denotes a first spring member, both ends of which are supported by the bottom surface of the inner diameter hole 16a of the piston 16 and the end surface of the large diameter portion 18a of the casing 18, and are attached to the outer peripheral portion of the large diameter portion 18a. The sealing element 16 of the piston 16 is brought into contact with the valve body 11 by the elastic force of the first spring member 19.

On the other hand, the pilot valve portion 14 is fitted to the valve casing 12 and is integrally formed with the valve casing 12 and has a U-shaped fixed core 23 having a flange portion 23a, and the outer peripheral surface of the fixed core 23 is fitted into the outer peripheral surface 23b. The inserted bobbin 24, the coil 25 wound around the inner diameter of the bobbin 24, the yoke 26 inserted into the inner diameter portion of the coil 25, and the movable iron core inserted into the inner peripheral surface of the yoke 26 27, a second spring member 28 fitted into the substantially axial core of the movable iron core 27 and having an upper end engaged with the lower surface of the fixed iron core 27, a lower surface of the yoke 26, and an inner diameter hole in the casing 18. A seat holder 29 that is slidably engaged, and a ball member 31 of a steel ball that is engaged with the valve seat 30 and the movable iron core 27 that are fitted into the upper portion of the seat holder 29 are provided.
The volume of the piston chambers 39 and 40 can be minimized by positioning the valve seat 30 of the pilot valve portion 14 on the piston 16 side, and the response time of the piston portion 13 with respect to opening and closing of the pilot valve portion 14 is shortened. be able to.

  The valve seat 30 is provided with an opening hole 38 connected to a communication hole 37 formed in the seat holder 29. The ball member 31 functions as a seal member for the pilot valve portion 14. For this reason, the ball member 31 is integrated into the movable core 27 by press-fitting or caulking after being inserted into the recess 36 formed in the movable core 27. The sealing surface of the valve seat 30 is formed in a conical or hemispherical cross section, and the engagement between the spherical surface of the ball member 31 and the inner peripheral surface of the valve seat 30 is not a face seal but a line seal. Strong against foreign objects.

The ratio of the hole diameter of the opening hole 38 formed in the seat holder 29 to the ball member 31 is preferably 0.5 to 0.75.
Further, first and second filters 32 a and 32 b for preventing intrusion of foreign matter and dust are mounted on the lower surface of the piston 16 and between the valve seat 30 and the concave surface of the seat holder 29. The first filter 32a is fixed to the piston 16 by ultrasonic welding, and the second filter 32b is integrated with the valve seat 30 by welding, caulking, insert molding or the like.
The second filter 32b may be separated from the valve seat 30 and fixed to the bottom surface 29a of the seat holder 29 by ultrasonic welding.

The first and second filters 32a and 32b only need to have at least one of them.
Further, as shown in FIG. 1, the air bypass valve 10 is closed, and when the pilot valve portion 14 is not excited, the pressure of the piston chambers 39 and 40 and the supercharging of the valve body 11 via the throttle 35 of the piston 16 are performed. The pressures on the machine discharge side 34 are equal, and the force balance with respect to the pressure acting on the piston 16 is maintained.
As a result, the piston 16 is pressed downward by the elastic force of the first spring member 19 as shown in FIG. 1, and the sealing element 16b on the lower surface of the piston 16 is opened on the supercharging discharge side 34 of the valve body 11. And the communication between the supercharging soot discharge side 34 and the supercharging soot suction side 33 is cut off.

When the pilot valve unit 14 is energized, the movable core 27 is displaced upward in FIG.
The ball member 31 is integrated with the movable iron core 27, and the ball member 31 is separated from the valve seat 30.
For this reason, the piston chambers 39 and 40 and the drain port 22 are connected, and the pressure in the piston chambers 39 and 40 decreases.
The force due to the difference between the pressures of the piston chambers 39 and 40 and the pressure on the supercharger discharge side 34 of the valve body 11 acts on the piston 16 to overcome the resilience of the first spring member 19, and the piston 16 is shown in FIG. 1, the air bypass valve 10 opens.
At this time, the stroke of the piston 16 is determined by the pressure difference and the elastic force of the first spring member 19.

When the stroke is ended as shown in FIG. 3, the piston chamber 39 and the piston chamber 40 are connected by the groove 16 d formed by the casing 18 and the piston 16. Since air can be sucked and discharged between the piston chambers 39 and 40, the closing response of the piston 16 from the stroke end is improved.
Reference numeral 42 denotes a non-magnetic spacer, which is provided between the bottom surface of the movable iron core 27 and the upper surface of the seat valve 29 to block contact between the movable iron core 27 and the seat valve 29.

The air bypass valve 10 according to the present embodiment is basically configured as described above. Next, the operation will be described.
When the pilot valve section 14 is energized, the movable iron core (plunger) 27 is moved upward in FIG. 1 by electromagnetic force, and the ball member 31 integrated with the movable iron core 27 is separated from the valve seat 30, and the piston chamber 39 and 40 and the drain port 22 are connected.
The pressure in the piston chambers 39 and 40 is higher than the pressure on the supercharger suction side 33, and the gas in the piston chambers 39 and 40 flows out from the drain port 22. At this time, the gas in the piston chambers 39 and 40 flows from the throttle 35 of the piston 16, but the opening of the pilot valve portion 14 is determined by the stroke of the movable iron core 27 and the opening 38 of the valve seat 30 compared to the cross-sectional area of the throttle 35. Since the area (see FIG. 3) is large, more gas flows out of the piston chambers 39 and 40.
Accordingly, the pressure in the piston chambers 39 and 40 is reduced, and a force upward of the piston 16 is generated due to the pressure difference between the piston chambers 39 and 40 and the supercharger discharge side 34 of the valve body 11.
For this reason, the sealing element 16b of the piston 16 is separated from the valve body 11, the bypass valve 10 is opened, and the supercharger discharge side 34 and the supercharger suction side 33 are connected.

When the pilot valve section 14 is de-energized, the electromagnetic force of the pilot valve section 14 is lost, and the movable iron core 27 moves downward in FIG. A ball member 31 integrated with the iron core 27 is seated on the valve seat 30. As a result, the piston chambers 39 and 40 and the drain port 22 are shut off.
Therefore, gas flows into the piston chambers 39 and 40 from the throttle 35 of the piston 16, and the difference between the pressure on the supercharger discharge side 34 and the pressure on the piston chambers 39 and 40 becomes small. The piston 16 is moved downward by the force, and the sealing element 16 b of the piston 16 is seated on the valve body 11.

As described above, in the air bypass valve 10 of the present embodiment, when the pilot valve portion 14 is opened, air flows out into the piston chambers 39 and 40, and the pressure difference between the supercharger discharge side 34 and the piston chambers 39 and 40. As a result, the piston 16 overcomes the first spring member 19 and moves upward in FIG.
When the pilot valve section is closed, air flows into the piston chambers 39 and 40, and the pressure difference between the supercharger discharge side 34 and the piston chambers 39 and 40 is reduced, so that the first spring member 19 is elastic. Due to the force, the piston 16 moves downward in FIG.
At this time, since the valve seat 30 of the pilot valve portion 14 is located on the piston 16 side, the volume of the piston chambers 39 and 40 can be reduced, and the piston chambers 39 and 40 flow in and out during the piston stroke. The amount of air is small.
For this reason, in the air bypass valve 10 of the present embodiment, the position of the valve seat 30 of the pilot valve portion 14 is located on the piston 16 side, and the volume of the piston chambers 39 and 40 is reduced to reduce the ON response and the OFF response. Will improve.

FIG. 6 is a schematic longitudinal sectional view showing a schematic structure of an air bypass valve according to the second embodiment of the present invention. In FIG. 6, the same components as those in FIG. Detailed description is omitted.
As shown in FIG. 7, the throttle 51 has a structure in which at least one end around both ends in the axial direction is formed in a protruding shape, so that oil transmitted from the surface of the piston 16 or the bottom surface of the piston 16 does not easily enter the throttle 51. The clogging of the diaphragm 51 can be prevented.

The seal member 52 has an L-shaped cross section, the inner side in the axial direction is in contact with the outer peripheral surface of the piston 16, and the upper and lower surfaces are sandwiched between the casing 18 and the piston casing 15.
Thereby, even if temperature changes, the leakage of the air from the packing outer-diameter side by the difference in heat-shrinkability of a packing and a piston casing can be prevented.
As shown in FIG. 6, the groove 16d may be provided at the tip of the piston 16 without forming the flange 16c.

DESCRIPTION OF SYMBOLS 10, 50 Air bypass valve 11 Valve body 12 Valve casing 13 Piston part 14 Pilot valve part 15 Piston casing 16 Piston 17, 52 Seal member 18 Casing 19, 28 Spring member 21 Claw 22 Drain port 23 Fixed iron core 27 Movable iron core 29 Seat holder 30 Valve seat 31 Ball member 32a, 32b Filter 33 Supercharger suction 34 Supercharger discharge side 35, 51 Restriction 36 Recess 37 Communication hole 38 Open hole 39, 40 Piston chamber 41 Spacer

Claims (7)

A convex valve casing attached to the valve body;
A piston portion fitted into the large inner diameter portion of the valve body;
A pilot valve portion engaged with the piston portion and inserted into the valve body;
The piston portion includes a stepped cylindrical piston casing that is engaged with an inner peripheral surface of the valve body, a stepped cylindrical piston casing that is engaged with an inner peripheral surface of the valve body, and the piston. A cylindrical piston fitted into the innermost surface of the casing and having a bottom surface; a seal member mounted on the inner peripheral surface of the piston casing and contacting the outer peripheral surface of the piston; and a large inner diameter of the piston casing A casing with a concave-convex cross-section that is housed in a portion and is inserted into the upper surface of the piston casing and the valve body;
A first spring member mounted on the outer peripheral portion of the casing and mounted on the inner peripheral surface of the piston;
The pilot valve portion is mounted on the valve body and formed integrally with the valve body, and has a U-shaped fixed core, a bobbin fitted on the outer peripheral surface of the fixed core, and the bobbin wound around A coil, a yoke fitted into the inner diameter of the coil, a movable core fitted into the inner peripheral surface of the yoke, and an upper end fitted into the substantially axial core of the movable iron core on the lower surface of the fixed core A second spring member to be engaged, a seat holder in contact with the lower surface of the yoke, a valve seat fitted to the seat holder, and a ball member to be engaged with the recess of the movable iron core,
The air bypass valve according to claim 1, wherein at least three protrusions for guiding the outer peripheral surface of the piston are provided in the circumferential direction in the piston casing so as to be oriented in the longitudinal direction of the piston. The air bypass valve according to claim 1,
An air bypass valve characterized in that a delay in response at the piston stroke end during operation is prevented by providing at least one radial groove at the upper end of the piston. The air bypass valve according to claim 1 or 2,
An air bypass valve according to claim 1, wherein a taper shape is provided at a rear end portion of the piston to improve the assembling property of the seal member. The air bypass valve according to any one of claims 1 to 3,
An air bypass valve, wherein one filter is mounted between a lower surface of the piston or the valve seat and a concave surface of the seat holder. The air bypass valve according to any one of claims 1 to 4,
An air bypass valve characterized in that an ON response and an OFF response are improved by reducing the volume of the piston chamber by positioning the valve seat of the pilot valve portion on the piston side. The air bypass valve according to any one of claims 1 to 5,
An air bypass valve characterized in that the throttle is formed in a protruding shape at least one end around both ends in the axial direction.



The air bypass valve according to any one of claims 1 to 6,
The air bypass valve according to claim 1, wherein the seal member has an L-shaped cross section, the inner side is in contact with the outer peripheral surface of the piston, and the upper and lower surfaces are sandwiched between the piston casing and the casing.

Images