JP6742781B2 - Check valve for negative pressure booster - Google Patents

Description

The present invention relates to a negative pressure booster check valve provided between a negative pressure booster and a negative pressure source, the valve seat, a disc, and a cylindrical seal rising from the outer periphery of the disc toward the valve seat. TECHNICAL FIELD The present invention relates to a check valve for a negative pressure booster, which includes an elastic valve body having a lip, and a valve support body that supports the disc from behind with a chevron surface that moves away from the back surface of the disc toward the outer circumference of the disc.

Patent documents 1 and 2 disclose a check valve for a negative pressure booster. The check valve includes an elastic valve body that sits on a valve seat. The valve body has a disc and a cylindrical seal lip rising from the outer periphery of the disc toward the valve seat. The disc of the valve body is supported from behind by a valve support. The valve support faces the back side of the disc with a chevron that moves away from the back side of the disc as it moves toward the outer circumference of the disc.

JP-A-9-202229 Japanese Utility Model Publication No. 6-10671

When a large driving force acts on the valve support in the valve closing direction, the center of the disc is excessively pushed, which may cause excessive deformation of the valve body, which is a sealing member, and may reduce durability. It was

An object of the present invention is to provide a check valve for a negative pressure booster, which can improve durability and sealability.

According to the first aspect of the present invention, there is provided a negative pressure booster check valve provided between a negative pressure booster and a negative pressure source, comprising a valve seat, a disc and an outer periphery of the disc to the valve seat. An elastic valve body having a cylindrical seal lip rising toward the side, a valve support body that supports the disc from behind with a chevron surface that is distant from the back surface of the disc toward the outer periphery of the disc, and the seal. A stopper mechanism for restricting the movement of the valve support toward the valve seat when the lip is seated , the stopper mechanism having a guide surface that comes into contact with the outer peripheral surface of the seal lip, and a centrifugal direction of the seal lip. A stopper piece that extends outward from the valve support toward the valve seat and restricts the distance between the valve seat and the valve support when coming into contact with the valve seat is provided. have the original to back by a certain distance, the specified distance is a negative pressure backside is set to a distance that does not contact the angled surface of the disc when the leading end of the stopper piece is in contact with the valve seat Check valves for boosters are provided.

According to the second side surface, in addition to the structure of the first side surface, the stopper pieces are arranged at equal intervals.

According to the fourth aspect, while the vehicle is traveling, the airflow can flow into the inside of the second protector from the gap, and the heat buildup inside the first protector and the second protector can be suppressed.

Further , the stopper mechanism can be configured with a simple shape. Since the stopper piece is integrated with the valve support, the stopper mechanism can be provided without increasing the number of parts.

Moreover , even if the disc of the valve element is pushed in at the center due to the influence of the chevron surface, the seal lip is supported by the guide surface of the stopper piece, so that the deformation of the seal lip in the outer diameter direction can be suppressed.

According to the second side surface, the stopper pieces are arranged at equal intervals in the circumferential direction of the disc. Therefore, the deformation is evenly received in the circumferential direction. In this way, variations in the contact pressure distribution can be suppressed.

It is a side view of the partial section which shows roughly the composition of the negative pressure booster concerning one embodiment. It is an expanded sectional view of the check valve for negative pressure boosters concerning a 1st embodiment. It is a partial expanded sectional view showing roughly composition of a stopper piece. FIG. 4 is a partial enlarged sectional view corresponding to FIG. 3 and schematically showing a configuration of a stopper piece in a valve open state. It is an expanded sectional view of the check valve for negative pressure boosters concerning a 2nd embodiment.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows a configuration of a negative pressure booster according to one embodiment. The negative pressure booster 11 includes a booster shell 12. The inner space of the booster shell 12 is partitioned by a diaphragm 13 into a negative pressure chamber 14 on the front side and a working 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 a brake device of an automobile. 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 connected 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 on the rear wall of the booster shell 12 so as to be movable back and forth in the axial direction. An arm 23 a of a brake pedal 23 is connected to a 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 at rest, the booster piston 19 and the input shaft 21 are located at the backward limit, and the negative pressure of the negative pressure material 14 is transmitted to the working chamber 15 via a control valve (not shown), and the negative pressure chamber 14 and The working chamber 15 has the same pressure. When the brake pedal 23 is depressed and the input shaft 21 moves forward, atmospheric pressure is introduced into the working chamber 15 according to the operation of the control valve. The booster piston 19 moves forward according to the pressure difference between the working 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 housing main body 26a that defines the valve chamber 27 therein, and a lid 26b that closes the open end of the valve chamber 27. Both the housing body 26a and the lid 26b may be made of synthetic resin, for example. The lid 26b is coupled to the open end of the housing body 26a. A groove 28 is formed around the central axis Xis on the inner wall surface of the housing body 26a for coupling. Engagement claws 29 are formed in the cylindrical portion of the lid body 26b fitted into the open end of the valve chamber 27 so as to correspond to the grooves 28. The engaging claw 29 projects outward in the centrifugal direction from the cylindrical surface of the cylindrical portion. The engagement of the engaging claw 29 into the groove 28 maintains the connection between the housing body 26a and the lid 26b.

A grommet 31 is attached to the outer periphery of the housing body 26a. The grommet 31 is molded 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 hermetically inserted into the mounting hole 32 by the function of the grommet 31.

A valve seat 33 is arranged in the valve chamber 27. The valve seat 33 is formed on the housing body 26a. The valve seat 33 defines an 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.

A connection pipe 36 that partitions the negative pressure inlet port 35 is formed in the lid 26b. The 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.

Inside the valve chamber 27, an elastic valve body 37 and a metal body (or hard resin molded body) valve support body 38 are arranged. The valve element 37 includes a disc 39 and a cylindrical seal lip 41 that rises from the outer periphery of the disc 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 valve element 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 33 a of the valve seat 33. The seated valve element 37 closes the negative pressure outlet port 34.

The valve body 37 is attached to the front end of the valve support body 38. Upon mounting, the valve support 38 has a locking portion 38a that has a conical shape at its tip, penetrates the center of the disc 39, and is retained by the disc 39. The disc 39 of the valve body 37 is supported from behind by the chevron surface 42 of the valve support body 38. The chevron surface 42 is defined by, for example, a conical surface that moves away from the back surface of the disc 39 toward the outer circumference of the disc 39. The conical surface is arranged coaxially with the central axis line Xis of the negative pressure outlet port 34. The valve support 38 contacts the back surface of the disc 39 at the top and bottom of the chevron, and the chevron surface 42 faces the back surface of the disc 39 outside the contact area.

The valve support body 38 is formed with a valve shaft 43 extending rearward from the chevron surface 42. The valve shaft 43 is arranged coaxially with the central axis line Xis of the negative pressure outlet port 34. The valve shaft 43 is inserted into a guide boss 44 arranged in the valve chamber 27. A guide hole 45 that receives the valve shaft 43 is defined in the guide boss 44 so as to be slidable in the front-back direction. The guide boss 44 is continuous from the connecting pipe 36 via a plurality of ribs 46. The rib 46 connects the valve chamber 27 and 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 valve support 38. The valve spring 47 exerts an elastic force that presses the valve body 37 toward the valve seat 33. When the negative pressure introduced from the negative pressure inlet port 35 acts on the valve body 37 and exceeds the pressing force of the valve spring 47, the valve body 37 moves backward together with the valve support body 38 against the elastic force of the valve spring 47. To do. In response to the retreat, the seal lip 41 separates from the flat surface 33a of the valve seat 33, and negative pressure is introduced into the negative pressure chamber 14 from the negative pressure outlet port 34.

As shown in FIG. 3, the check valve 18 includes a stopper mechanism ST that restricts the movement of the valve support body 38 toward the valve seat 33 when the seal lip 41 is seated. Here, the stopper mechanism ST has one or more stopper pieces 48 extending from the valve support body 38 toward the valve seat 33 on the outer side of the seal lip 41 in the centrifugal direction.

The stopper piece 48 has a guide surface 51 that contacts the outer peripheral surface of the seal lip 41. The guide surface 51 may contact at least the outer peripheral surface of the seal lip 41 when the tip of the stopper piece 48 is received by the flat surface 33a of the valve seat 33. The stopper pieces 48 are arranged around the central axis Xis of the negative pressure outlet port 34 at evenly spaced center angles. Alternatively, the stopper piece 48 may be formed continuously as one piece in the circumferential direction.

As shown in FIG. 4, the tip of the stopper piece 48 has an original shape retracted from the tip of the seal lip 41 at a specific distance c in the direction of the axis Xis of the negative pressure outlet port 34. The distance c is set to a size such that the seal lip 41 ensures sufficient airtightness when the tip of the stopper piece 48 contacts the flat surface 33a of the valve seat 33, and the tip of the stopper piece 48 contacts the valve seat 33. the rear surface of the disc 39 may be Re is set to a distance that does not contact the angled surface 42 upon contact. When the stopper piece 48 contacts the valve seat 33, the stopper piece 48 regulates the distance between the valve seat 33 and the valve support body 38. A gap may exist between the guide surface 51 and the outer peripheral surface of the seal lip 41 as long as the tip of the stopper piece 48 is away from the flat surface 33a of the valve seat 33.

Even if the valve support body 38 moves forward toward the valve seat 33 due to a large driving force acting on the valve support body 38 in the direction in which the valve body 37 is pressed toward the valve seat 33, the tip of the stopper piece 48 is The valve support 38 is restricted from moving against the flat surface 33a of 33. Therefore, the amount of deformation of the valve element 37 can be regulated, and excessive deformation of the seal lip 41 can be avoided. The surface pressure of the sealing surface of the seal lip 41 can be kept uniform, and the sealing performance can be improved.

In the check valve 18, the stopper piece 48 extends from the valve support body 38 toward the valve seat 33 on the outer side of the seal lip 41 in the centrifugal direction. Therefore, the stopper mechanism ST can be configured with a simple shape. Moreover, since the stopper piece 48 is integrated with the valve support 38, the stopper mechanism ST can be provided without increasing the number of parts.

When a large driving force acts on the valve support body 38 in the direction of pressing the valve body 37 toward the valve seat 33, even if the disc 39 of the valve body 37 is pushed in by the influence of the chevron surface 42, the stopper piece Since the seal lip 41 is supported by the guide surface 51 of 48, deformation of the seal lip 41 in the outer diameter direction can be suppressed.

The stopper pieces 48 are arranged at equal intervals in the circumferential direction of the disc 39. Therefore, the deformation is evenly received in the circumferential direction. In this way, variations in the contact pressure distribution can be suppressed.

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

18... Negative pressure booster check valve, 33... Valve seat, 33a... Plane, 37... Valve body, 38... Valve support body, 39... Disc, 41... Seal lip, 42... Chevron surface, 48... Stopper piece, 51 ... guide surface, c... specific distance, ST... stopper mechanism.

Claims (2)

A check valve for a negative pressure booster provided between a negative pressure booster and a negative pressure source,
A valve seat (33),
An elastic valve body (37) having a disc (39) and a cylindrical seal lip (41) rising from the outer periphery of the disc (39) toward the valve seat (33);
A valve support (38) for supporting the disc (39) from behind with a chevron surface (42) that moves away from the back surface of the disc (39) as it goes toward the outer periphery of the disc (39);
A stopper mechanism (ST) for restricting movement of the valve support body (38) toward the valve seat (33) when the seal lip (41) is seated ,
The stopper mechanism (ST) has a guide surface (51) in contact with the outer peripheral surface of the seal lip (41), and extends from the valve support (38) to the valve outside the seal lip (41) in the centrifugal direction. A stopper piece (48) that extends toward the seat (33) and restricts the distance between the valve seat (33) and the valve support (38) when the valve seat (33) comes into contact;
The tip of the stopper piece (48) has an original shape retracted from the tip of the seal lip (41) by a specific distance (c), and the tip of the stopper piece (48) is at the specific distance (c). It said disc (39) back side negative pressure check valve for booster, characterized that you have been set to a distance that does not contact the angled surface (42) of the time in contact with the valve seat (33). The check valve for a negative pressure booster according to claim 1 , wherein the stopper pieces (48) are arranged at equal intervals.

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