JP6773432B2 - Check valve for negative pressure booster - Google Patents

Description

The present invention relates to, for example, a check valve for a negative pressure booster used by being connected to a negative pressure booster for a braking device of an automobile. For example, a valve seat arranged in a passage leading to a negative pressure chamber of the negative pressure booster and a valve seat. The present invention relates to a check valve for a negative pressure booster including a soft seal member that sits on the seat and a hard seal support member that supports the seal member from behind.

Patent Documents 1 and 2 disclose a check valve for a negative pressure booster. If no negative pressure acts from the negative pressure source, the valve body sits on the valve seat under the elastic force of the valve spring. When the negative pressure increases, the valve body is displaced in the direction away from the valve seat against the elastic force of the valve spring. The valve body includes a soft seal member and a hard seal support member. Good airtightness is achieved by seating the flexible sealing member.

Japanese Unexamined Patent Publication No. 9-20222 Jikkenhei 6-10671

The soft sealing member faces the space leading to the negative pressure booster (negative pressure chamber) on the front surface and the space communicating with the negative pressure source on the rear surface. There is a risk that the valve opening pressure of the seal member (valve body) will change depending on factors such as the usage environment, resulting in variations in valve opening performance.

An object of the present invention is to provide a check valve for a negative pressure booster capable of suppressing variations in valve opening performance.

According to the first aspect of the present invention, it is a check valve for a negative pressure booster arranged in a passage leading to a negative pressure chamber of the negative pressure booster, and is a planar valve extending along a plane orthogonal to the axis of the passage. a housing having a seat, a valve body and a sealing lip of the cylindrical rises toward said valve seat from the outer periphery of the flat disc and the disc is arranged in a position facing the said valve seat An annular seal member to be configured, and a seal support member to which the seal member is attached and having a flange portion that protrudes in the outer radial direction from the seal member behind the seal member, and the seal lip is the valve seat. Provided is a check valve for a negative pressure booster in which the gap between the flange portion and the inner peripheral wall of the housing is minimized when the seal member abuts on the valve seat from a direction orthogonal to the valve seat .

According to the second side surface, in addition to the configuration of the first side surface, the housing is provided with an inclined surface facing the flange portion of the seal support member and increasing in diameter as the distance from the valve seat increases, and in a seated state. A part of the flange portion and the inclined surface is arranged so as to overlap in the valve body axial direction.

According to the third side surface, in addition to the configuration of the second side surface, the housing is coupled to the first housing member for partitioning the inclined surface and the open end of the first housing member to form the first housing member. It has a seal member and a second housing member for partitioning a valve chamber accommodating the seal support member.

According to the first side surface, when the seal member, which is a valve body, is seated, the gap between the seal support member and the inner peripheral wall of the housing is the narrowest, and the negative pressure source is provided on the flange portion having a diameter larger than that of the seal member. Since the negative pressure acts, a sufficient force to pull the seal member in the direction away from the valve seat can be sufficiently obtained. As a result, even if the valve opening pressure changes slightly depending on the usage environment or the like, the delay in the valve opening timing can be suppressed as much as possible, and the variation in the valve opening performance can be suppressed.

According to the second side surface, the gap between the seal support member and the inner peripheral wall of the housing can be made the narrowest in the seated state, and the negative pressure of the negative pressure source acts on the seal member and the seal support. As the distance from the valve seat increases, the flange portion of the seal support member moves away from the inclined surface, so that the gap increases. Therefore, since a sufficient flow rate is instantly secured after the valve is opened once, the responsiveness of introducing negative pressure can be maintained.

According to the third side surface, the first housing member can be easily formed with an inclined surface extending toward the open end.

It is a side view of the partial cross section which shows roughly the structure of the negative pressure booster which concerns on one Embodiment. It is an enlarged sectional view of the check valve which concerns on 1st Embodiment. It is a partially enlarged sectional view which shows the structure of the main part of a check valve roughly. It is a partially enlarged sectional view which shows roughly the structure of the main part of a check valve in a valve open state. It is an enlarged sectional view of the check valve which concerns on 2nd Embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 schematically shows the configuration of a negative pressure booster according to one embodiment. The negative pressure booster 11 includes a booster shell 12. The internal space of the booster shell 12 is partitioned by a diaphragm 13 into a negative pressure chamber 14 on the front side and an operating chamber 15 on the rear side. A negative pressure source 17 is connected to the negative pressure chamber 14 via a negative pressure conduit 16. A check valve 18 is arranged in the negative pressure conduit 16. Such a negative pressure booster 11 is used, for example, in an automobile braking device. In this case, the intake manifold of the engine is used as the negative pressure source 17. Negative pressure from the intake manifold acts on the negative pressure chamber 14.

The negative pressure booster 11 includes a booster piston 19 housed in the booster shell 12. The booster piston 19 is coupled to the diaphragm 13. An input shaft 21 is connected to the booster piston 19 via a control valve (not shown). The input shaft 21 is supported by the rear wall of the booster shell 12 so as to be movable back and forth in the axial direction. An arm 23a of the brake pedal 23 is connected to the rear end of the input shaft 21 via a yoke 22.

A brake master cylinder 24 is connected to the front wall of the booster shell 12. The booster piston 19 is connected to the piston of the brake master cylinder 24 via an output shaft (not shown). When the negative pressure booster 11 is paused, the booster piston 19 and the input shaft 21 are located at the retreat limit, and the negative pressure of the negative pressure chamber 14 is transmitted to the operating chamber 15 via a control valve (not shown), and the negative pressure chamber 14 and the negative pressure chamber 14 The working chamber 15 has the same pressure. When the brake pedal 23 is depressed and the input shaft 21 advances, atmospheric pressure is introduced into the operating chamber 15 in response to the operation of the control valve. The booster piston 19 moves forward according to the pressure difference between the operating chamber 15 and the negative pressure chamber 14 to boost the brake master cylinder 24.

The check valve 18 includes a housing 26. As shown in FIG. 2, the housing 26 is formed of a cylindrical second housing member 26a that internally partitions the valve chamber 27 and a first housing member 26b that closes the open end of the valve chamber 27. Both the second housing member 26a and the first housing member 26b may be molded from, for example, synthetic resin. The first housing member 26b is coupled to the open end of the second housing member 26a. At the time of joining, a groove 28 is formed on the inner wall surface of the second housing member 26a around the central axis Xis. A engagement claw 29 is formed in the cylindrical portion of the first housing member 26b that fits into the open end of the valve chamber 27, corresponding to the groove 28. The engagement claw 29 protrudes outward from the cylindrical surface of the cylindrical portion in the centrifugal direction. By fitting the engagement claw 29 into the groove 28, the connection between the second housing member 26a and the first housing member 26b is maintained.

A grommet 31 is attached to the first housing member 26b. The grommet 31 is formed from an elastic material such as rubber. The grommet 31 is fitted into the mounting hole 32 formed in the front wall of the booster shell 12. The check valve 18 is airtightly inserted into the mounting hole 32 by the action of the grommet 31.

A valve seat 33 is arranged in the valve chamber 27. The valve seat 33 is formed on the first housing member 26b. The valve seat 33 partitions the annular flat surface 33a. The plane 33a surrounds the negative pressure outlet port 34 in the cylindrical space. The negative pressure outlet port 34 connects the negative pressure chamber 14 of the booster shell 12 to the valve chamber 27. In this way, the valve seat 33 is arranged at the opening of the passage leading to the negative pressure chamber 14.

A connecting pipe 36 for partitioning the negative pressure inlet port 35 is formed in the second housing member 26a. A negative pressure conduit 16 is connected to the connecting pipe 36. The negative pressure inlet port 35 connects the intake manifold to the valve chamber 27. The negative pressure of the intake manifold acts on the valve chamber 27.

An elastic seal member 37 and a metal (or hard resin molded) seal support member 38 are arranged in the valve chamber 27. The seal member 37 has a disk 39 and a cylindrical seal lip 41 that rises from the outer circumference of the disk 39 toward the valve seat 33. The disc 39 and the seal lip 41 are arranged coaxially with the central axis Xis of the negative pressure outlet port 34. When the seal member 37 advances from the retracted position toward the valve seat 33 in the direction of the central axis Xis, the tip of the seal lip 41 is seated on the flat surface 33a of the valve seat 33. The seated seal member 37 closes the negative pressure outlet port 34.

The seal member 37 is attached to the front end of the seal support member 38. Upon mounting, the seal support member 38 has a locking portion 38a having a conical shape at the tip, penetrating the center of the disc 39, and being anchored to the disc 39. The disk 39 of the seal member 37 is supported from behind by the seal support member 38. The seal support member 38 has a flange portion 42 that projects behind the seal member 37 in the outer diameter direction from the seal member 37.

A valve shaft 43 extending rearward is formed on the seal support member 38. The valve shaft 43 is arranged coaxially with the central axis Xis of the negative pressure outlet port 34. The valve shaft 43 is inserted into the guide boss 44 arranged in the valve chamber 27. The guide boss 44 is partitioned with a guide hole 45 that receives the valve shaft 43 so as to be slidable in the front-rear direction. The guide boss 44 is continuous from the connecting pipe 36 via the plurality of ribs 46. The rib 46 communicates the valve chamber 27 with the negative pressure inlet port 35.

A valve spring 47 is housed in the valve chamber 27. The valve spring 47 is arranged between the rear wall of the valve chamber 27 and the seal support member 38. The valve spring 47 exerts an elastic force that presses the seal member 37 toward the valve seat 33. When the negative pressure introduced from the negative pressure inlet port 35 acts on the seal member 37 and exceeds the pressing force of the valve spring 47, the seal member 37 retracts together with the seal support member 38 against the elastic force of the valve spring 47. To do. The seal lip 41 separates from the flat surface 33a of the valve seat 33 in accordance with the retreat, and negative pressure is introduced from the negative pressure outlet port 34 into the negative pressure chamber 14.

As shown in FIG. 3, the seal member 37 forms a circular pressure receiving surface 51 facing the space in the negative pressure outlet port 34 leading to the negative pressure chamber 14. The pressure receiving surface 51 has a first area. The first area is defined by the outer diameter D1 of the seal lip 41. The flange portion 42 of the seal support member 38 forms a circular pressure receiving surface 52 facing the space leading to the negative pressure source 17 (negative pressure inlet port 35). The pressure receiving surface 52 has a second area larger than the first area. That is, the flange portion 42 of the seal support member 38 has an outer diameter D2 larger than the outer diameter D1 of the seal lip 41.

The housing 26 (here, the first housing member 26b) is partitioned by an inclined surface 53 that continuously extends from the outer periphery of the valve seat 33 toward the open end. The inclined surface 53 faces the flange portion 42 of the seal support member 38 when the seal member 37 is seated. In this way, a gap g is formed on the outer periphery of the flange portion 42 of the seal support member 38. When the seal member 37 is seated, the gap g is the smallest (narrower). Further, in the seated state, the inclined surface 53 and the flange portion 42 are arranged so as to partially overlap each other in the axial direction of the valve body. The inclined surface 53 approaches the outer periphery of the flange portion 42 of the seal support member 38 as it moves away from the flat surface 33a of the valve seat 33 in the seated state, and is connected to the first housing member 26b at the open end. As shown in FIG. 4, when the seal member 37 moves away from the flat surface 33a of the valve seat 33 in response to the front-back movement of the seal support member 38, the gap g on the outer circumference of the seal support member 38 increases.

In a state where the negative pressure from the negative pressure source 17 does not act, the seal lip 41 of the seal member 37 of the valve body is seated on the flat surface 33a of the valve seat 33 by receiving the elastic force of the valve spring 47, so that the negative pressure booster 11 The space between the negative pressure chamber 14 and the valve chamber 27 is cut off. At this time, a gap g is maintained on the outer periphery of the flange portion 42 of the seal support member 38.

When the negative pressure from the negative pressure source 17 acts on the valve chamber 27 and exceeds the urging force of the valve spring 47, the seal member 37 is displaced in the direction away from the valve seat 33 against the elastic force of the valve spring 47. .. At this time, the gap g is the narrowest in the seated state, and acts on the pressure receiving surface 52 of the second area where the negative pressure of the negative pressure source 17 is larger than the first area. Therefore, since a sufficient force is obtained to pull the seal member 37 and the seal support member 38 in the direction away from the valve seat 33, even if the valve opening pressure changes slightly due to the usage environment or the like, the delay in the valve opening timing is suppressed as much as possible. It is possible to suppress variations in valve opening performance.

The inclined surface 53 of the housing 26 faces the flange portion 42 of the seal support member 38. The inclined surface 53 approaches the outer periphery of the flange portion 42 of the seal support member 38 as it moves away from the valve seat 33 in the seated state. On the other hand, the negative pressure of the negative pressure source 17 acts on the pressure receiving surface 52 of the seal support member 38, and as the seal member 37 moves away from the valve seat 33 (valve opening), the flange portion 42 of the seal support member 38 has an inclined surface 53. The gap g increases with distance from. Therefore, in the check valve 18, a sufficient flow rate is instantly secured after the valve is opened, so that the responsiveness of introducing negative pressure can be maintained.

In the check valve 18, an inclined surface 53 extending from the valve seat 33 toward the open end is partitioned on the first housing member 26b. The valve chamber 27 is formed by connecting the second housing member 26a to the open end of the first housing member 26b. In this way, the first housing member 26b can be easily formed with an inclined surface 53 extending toward the open end.

As shown in FIG. 5, the check valve 18 may be arranged in the negative pressure conduit 16.

11 ... Negative pressure booster, 14 ... Negative pressure chamber, 18 ... Negative pressure booster check valve, 26 ... Housing, 26a ... Second housing member, 26b ... First housing member, 27 ... Valve chamber, 33 ... Valve seat, 37 ... Seal member, 38 ... Seal support member, 42 ... Flange portion, 51 ... Pressure receiving surface, 52 ... Pressure receiving surface, 53 ... Inclined surface, g ... Gap.

Claims (3)

A check valve for a negative pressure booster arranged in a passage leading to a negative pressure chamber (14) of the negative pressure booster (11).
A housing (26) with a planar valve seat (33) extending along a plane orthogonal to the axis of the passage .
A flat disk (39) arranged at a position facing the valve seat (33) and a cylindrical seal lip (41) rising from the outer circumference of the disk (39) toward the valve seat (33). An annular seal member (37) that has and constitutes a valve body , and
A seal support member (38) to which the seal member (37) is attached and having a flange portion (42) projecting behind the seal member (37) in the outer diameter direction from the seal member (37) is provided.
The flange portion (42) and the housing (26) are in a seated state of the seal member (37) in which the seal lip (41) abuts on the valve seat (33) from a direction orthogonal to the valve seat (33 ). A check valve for a negative pressure booster, characterized in that the gap (g) between the inner peripheral wall and the inner wall is the narrowest. In the check valve for a negative pressure booster according to claim 1, the housing (26) faces the flange portion (42) of the seal support member (38) and increases in diameter as it moves away from the valve seat (33). A negative pressure booster comprising an inclined surface (53) to be provided, and in a seated state, a part of the flange portion (42) and the inclined surface (53) is arranged so as to overlap in the valve body axial direction. Check valve for. In the check valve for a negative pressure booster according to claim 2, the housing (26) is
A first housing member (26b) that partitions the inclined surface (53) and
A valve chamber (27) that is coupled to the open end of the first housing member (26b) and accommodates the seal member (37) and the seal support member (38) between the first housing member (26b). A check valve for a negative pressure booster, which comprises a second housing member (26a) for partitioning.