JP2017178100A - Chech valve for negative pressure booster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a check valve for a negative pressure booster capable of improving durability and sealing property. A check valve 18 includes a valve seat 33, an elastic valve body 37 having a disk 39 and a cylindrical seal lip 41 rising from the outer circumference of the disk 39 toward the valve seat 33, and a disk. Restricts the movement of the valve support 38 that supports the disk 39 from behind with the chevron surface 42 that moves away from the back surface of the disk 39 toward the outer circumference of the 39 and the valve support 38 toward the valve seat 33 when the seal lip 41 is seated. A stopper mechanism ST is provided. [Selection diagram] Fig. 3

Description

  The present invention relates to a check valve for a negative pressure booster provided between a negative pressure booster and a negative pressure source, and includes a valve seat, a disc, and a cylindrical seal rising from the outer periphery of the disc toward the valve seat The present invention relates to a check valve for a negative pressure booster comprising: an elastic valve body having a lip; and a valve support body that supports the disk from the back with a mountain-shaped surface that moves away from the back surface of the disk toward the outer periphery of the disk.

  Patent Documents 1 and 2 disclose a check valve for a negative pressure booster. The check valve includes an elastic valve body that is seated on the valve seat. The valve body has a disc and a cylindrical seal lip that rises from the outer periphery of the disc toward the valve seat. The disc of the valve body is supported from behind by the valve support. The valve support is opposed to the back surface of the disk with a chevron surface that moves away from the back surface of the disk as it goes toward the outer periphery of the disk.

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

  If a large driving force is applied to the valve support in the valve closing direction, the center of the disc is excessively pushed, so that the valve body that is the seal member may be excessively deformed, leading to a decrease in durability. It was.

  An object of this invention is to provide the check valve for negative pressure boosters which can improve durability and a sealing performance.

  According to the first aspect of the present invention, there is provided a check valve for a negative pressure booster provided between a negative pressure booster and a negative pressure source, wherein the valve seat, a disc and an outer periphery of the disc are connected to the valve seat. An elastic valve body having a cylindrical seal lip that rises toward the outer periphery; a valve support body that supports the disk from the back with a mountain-shaped surface that moves away from the back surface of the disk toward the outer periphery of the disk; and the seal There is provided a check valve for a negative pressure booster comprising a stopper mechanism for restricting movement of the valve support toward the valve seat when the lip is seated.

  According to the second aspect, in addition to the configuration of the first side surface, the stopper mechanism extends from the valve support toward the valve seat on the outer side in the centrifugal direction of the seal lip, and comes into contact with the valve seat. A stopper piece for regulating the distance between the valve seat and the valve support is provided.

  According to the third aspect, in addition to the configuration of the second side surface, the stopper piece has a guide surface that contacts the outer peripheral surface of the seal lip.

  According to the 4th side, in addition to the composition of the 3rd side, the stopper piece is arranged at equal intervals.

  According to the first aspect, even if a large driving force acts on the valve support body in the direction of pressing the valve body toward the valve seat and the valve support body moves forward toward the valve seat, the valve support body is moved by the stopper mechanism. Movement is restricted. Therefore, the deformation amount of the valve body can be regulated, and excessive deformation of the seal lip is avoided. Further, the surface pressure of the seal surface of the seal lip can be kept uniform, and the sealing performance can be improved.

  According to the second aspect, 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.

  According to the third aspect, the seal lip is supported by the guide surface of the stopper piece even if the disc of the valve body is pushed in at the center due to the influence of the chevron surface, so that deformation of the seal lip in the outer diameter direction is suppressed. Can do.

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

It is a side view of the partial cross section which shows schematically the structure of the negative pressure booster which concerns on 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 which shows the structure of a stopper piece schematically. FIG. 4 is a partially enlarged cross-sectional view schematically showing a configuration of a stopper piece in a valve open state corresponding to FIG. 3. It is an expanded sectional view of the check valve for negative pressure boosters concerning a 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 an 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 front negative pressure chamber 14 and a rear working chamber 15. A negative pressure source 17 is connected to the negative pressure chamber 14 via a negative pressure conduit 16. A check valve 18 is disposed in the negative pressure conduit 16. Such a negative pressure booster 11 is used, for example, in an automobile brake device. In this case, an 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 accommodated 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 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 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 stopped, the booster piston 19 and the input shaft 21 are positioned in the retreat limit, and the negative pressure of the negative pressure material 14 is transmitted to the working chamber 15 via a control valve (not shown). 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 in response 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 body 26 a that defines a valve chamber 27 therein, and a lid body 26 b that closes the open end of the valve chamber 27. Both the housing body 26a and the lid body 26b may be molded from, for example, synthetic resin. The lid body 26b is coupled to the open end of the housing body 26a. A groove 28 is formed around the central axis line Xis on the inner wall surface of the housing body 26a for the coupling. Engaging claws 29 are formed corresponding to the grooves 28 in the cylindrical portion of the lid body 26 b fitted into the open end of the valve chamber 27. The engaging claws 29 protrude outward from the cylindrical surface of the cylindrical portion in the centrifugal direction. The engagement of the engaging claws 29 in the grooves 28 maintains the connection between the housing body 26a and the lid body 26b.

  A grommet 31 is attached to the outer periphery of the housing body 26a. 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 inserted into the mounting hole 32 in an airtight manner by the function of the grommet 31.

  A valve seat 33 is disposed in the valve chamber 27. The valve seat 33 is formed in the housing body 26a. The valve seat 33 defines an annular flat surface 33a. The flat surface 33a surrounds the negative pressure outlet port 34 of the cylindrical space. A negative pressure outlet port 34 connects the negative pressure chamber 14 of the booster shell 12 to the valve chamber 27.

  A connecting pipe 36 that defines the negative pressure inlet port 35 is formed in the lid body 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.

  An elastic valve body 37 and a metal body (or hard resin molded body) valve support 38 are disposed in the valve chamber 27. The valve body 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 disposed coaxially with the central axis Xis of the negative pressure outlet port 34. When the valve body 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 valve element 37 closes the negative pressure outlet port 34.

  The valve body 37 is attached to the front end of the valve support 38. When mounting, the valve support 38 has a locking portion 38 a that has a conical shape at the tip, passes through the center of the disk 39, and is locked to the disk 39. The disc 39 of the valve body 37 is supported from behind by a chevron surface 42 of the valve support 38. The chevron surface 42 is defined by, for example, a conical surface that moves away from the back surface of the disk 39 as it goes toward the outer periphery of the disk 39. The conical surface is arranged coaxially with the central axis Xis of the negative pressure outlet port 34. The valve support 38 is in contact with the back surface of the disc 39 at the top end of the mountain shape, and the chevron surface 42 is opposed to the back surface of the disc 39 outside the contact area.

  The valve support 38 is formed with a valve shaft 43 extending rearward from the chevron surface 42. The valve shaft 43 is disposed coaxially with the central axis Xis of the negative pressure outlet port 34. The valve shaft 43 is inserted into a guide boss 44 disposed in the valve chamber 27. The guide boss 44 is provided with a guide hole 45 that receives the valve shaft 43 slidably in the front-rear direction. The guide boss 44 continues from the connection pipe 36 via a plurality of ribs 46. The valve chamber 27 communicates with the negative pressure inlet port 35 by the rib 46.

  A valve spring 47 is accommodated in the valve chamber 27. The valve spring 47 is disposed 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 element 37 toward the valve seat 33. When the negative pressure introduced from the negative pressure inlet port 35 acts on the valve element 37 and exceeds the pressing force of the valve spring 47, the valve element 37 moves backward together with the valve support 38 against the elastic force of the valve spring 47. To do. The seal lip 41 moves away from the flat surface 33a of the valve seat 33 in accordance with the retreat, 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 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 38 toward the valve seat 33 outside 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 be in contact with the outer peripheral surface of the seal lip 41 when at least the tip of the stopper piece 48 is received by the flat surface 33 a of the valve seat 33. The stopper pieces 48 are arranged at equally spaced central angles around the central axis Xis of the negative pressure outlet port 34. In addition, the stopper piece 48 may be formed as one piece continuously in the circumferential direction.

  As shown in FIG. 4, the tip of the stopper piece 48 has an original shape that recedes from the tip of the seal lip 41 by a distance c in the direction of the center axis Xis of the negative pressure outlet port 34. The distance c may be set to a size that ensures sufficient airtightness with the seal lip 41 when the tip of the stopper piece 48 contacts the flat surface 33 a of the valve seat 33. When the stopper piece 48 comes into contact with the valve seat 33, the stopper piece 48 regulates the distance between the valve seat 33 and the valve support 38. If the tip of the stopper piece 48 is away from the flat surface 33 a of the valve seat 33, a gap may exist between the guide surface 51 and the outer peripheral surface of the seal lip 41.

  Even if a large driving force acts on the valve support 38 in the direction in which the valve body 37 is pressed toward the valve seat 33 and the valve support 38 advances toward the valve seat 33, the tip of the stopper piece 48 remains at the valve seat. The valve support 38 is restricted from moving against the flat surface 33a of 33. Therefore, the deformation amount of the valve body 37 can be regulated, and excessive deformation of the seal lip 41 is avoided. The surface pressure of the seal 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 38 toward the valve seat 33 outside 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 is applied to the valve support 38 in the direction in which the valve body 37 is pressed toward the valve seat 33, even if the disc 39 of the valve body 37 is pushed in at the center due to the angled surface 42, the stopper piece Since the seal lip 41 is supported by the 48 guide surfaces 51, 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, deformation is received evenly in the circumferential direction. In this way, variation in the contact pressure distribution can be suppressed.

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

  18 ... Check valve for negative pressure booster, 33 ... Valve seat, 33a ... Flat surface, 37 ... Valve body, 38 ... Valve support, 39 ... Disc, 41 ... Seal lip, 42 ... Angle face, 48 ... Stopper piece, 51 ... guide surface, ST ... stopper mechanism.

Claims (4)

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 disk (39) from the back with a chevron surface (42) moving away from the back surface of the disk (39) toward the outer periphery of the disk (39);
A check valve for a negative pressure booster, comprising a stopper mechanism (ST) for restricting movement of the valve support (38) toward the valve seat (33) when the seal lip (41) is seated.   The check valve for a negative pressure booster according to claim 1, wherein the stopper mechanism (ST) is directed from the valve support body (38) toward the valve seat (33) outside the seal lip (41) in the centrifugal direction. A check valve for a negative pressure booster, comprising a stopper piece (48) that extends and restricts the distance between the valve seat (33) and the valve support (38) when contacting the valve seat (33).   The check valve for a negative pressure booster according to claim 2, wherein the stopper piece (48) has a guide surface (51) that contacts an outer peripheral surface of the seal lip (41). Check valve.   The negative pressure booster check valve according to claim 3, wherein the stopper pieces (48) are arranged at equal intervals.

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