JP2013057341A - Check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a check valve capable of improving installation work efficiency of a negative pressure valve to a positive pressure valve, in a valve having the positive pressure valve and the negative pressure valve.SOLUTION: This check valve 1 includes a casing for forming a positive pressure valve seat 15, the positive pressure valve 30 energized by a spring S1 for the positive pressure valve and forming a negative pressure valve seat 37, and the negative pressure valve 50 installed in the positive pressure valve 30 and energized so as to abut on the negative pressure valve seat 37 by a spring S2 for the negative pressure valve. The negative pressure valve 50 has a body 51 having a shaft portion 52 and a cap 60 having, at the center, an installation hole 61 into which the shaft portion 52 is inserted and engaged. The cap 60 is arranged on the passage 14 side for communicating with the inside of a fuel tank of the casing, and contacts with/separates from the negative pressure valve seat 37. The body 51 has a spring seat 56 for supporting one end of the spring S2 for the negative pressure valve.

Description

  The present invention relates to a check valve that adjusts the pressure in a fuel tank of an automobile or the like.

  Conventionally, in a fuel tank of an automobile or the like, when the pressure in the fuel tank rises above a predetermined value, the fuel vapor is allowed to flow outside to prevent the fuel tank from bursting. Also, a check valve is attached to prevent the fuel tank from being crushed by allowing outside air to flow in from the outside of the fuel tank when it falls below a predetermined value.

  As a conventional check valve of this type, the following Patent Document 1 includes a casing main body, a sub casing, and a positive pressure valve and a negative pressure valve slidably disposed in a valve chamber, and the positive pressure valve includes a plurality of through holes. A negative pressure valve seat, the negative pressure valve has a plurality of legs inserted into the through-holes, and a cap that engages the legs is disposed in the positive pressure valve, between the positive pressure valve and the sub casing. A positive pressure spring is disposed, a negative pressure spring is disposed between the positive pressure valve and the cap, and a positive pressure passage for allowing fuel vapor to flow out is formed between the outer periphery of the positive pressure valve and the inner periphery of the casing body. A negative pressure flow path is formed between the inner periphery of the positive pressure valve, the outer periphery of the leg and the cap, and between the through hole and the leg. A check valve disposed outside the pressure spring is disclosed. That.

  Further, when assembling the negative pressure valve to the positive pressure valve, after inserting the plurality of legs of the negative pressure valve in alignment with the plurality of through holes of the positive pressure valve, the negative pressure spring is inserted into the positive pressure valve, The cap is attached to the negative pressure valve by engaging the engagement protrusions formed on the outer periphery of the cap with the respective engagement holes at the tips of the plurality of leg portions of the negative pressure valve, and the negative pressure valve is attached to the positive pressure valve. It is designed to be slidably assembled.

  When the pressure in the fuel tank rises, the positive pressure valve is pushed by the fuel vapor and slides away from the positive pressure valve seat, and the fuel vapor is discharged out of the tank, while when the pressure in the fuel tank falls, The negative pressure valve slides away from the negative pressure valve seat so that outside air is introduced into the fuel tank.

International Publication WO2010 / 064475 Pamphlet

  However, in the check valve described in Patent Document 1, when the negative pressure valve is assembled to the positive pressure valve, the plurality of legs of the negative pressure valve must be aligned with the plurality of through holes of the positive pressure valve, respectively. In addition, since the plurality of engaging protrusions on the outer periphery of the cap have to be engaged with the engaging holes formed at the tips of the plurality of legs, respectively, there is a problem in assembling workability because it is complicated and laborious. It was.

  Accordingly, an object of the present invention is to provide a check valve that can improve the workability of assembling the negative pressure valve with respect to the positive pressure valve in a valve having a positive pressure valve and a negative pressure valve.

  In order to achieve the above object, a check valve according to the present invention has one end connected to the inside of the fuel tank, the other end connected to the outside of the fuel tank, the inside forming a valve chamber, and a passage connected to the inside of the fuel tank. And a casing formed with a positive pressure valve seat, slidably disposed in the valve chamber, and urged to abut against the positive pressure valve seat by a positive pressure valve spring disposed in the casing, And a positive pressure valve having a negative pressure valve seat formed in an opening on the side of the communication passage to the fuel tank of the through passage, and the positive pressure valve so as to open and close the negative pressure valve seat. A negative pressure valve assembled to the pressure valve and biased to abut against the negative pressure valve seat by a negative pressure valve spring disposed in the positive pressure valve, the negative pressure valve protruding from the center of one end A main body having a shaft portion, and the shaft portion is inserted and engaged. A cap formed at the center of the mounting hole, and one of the main body and the cap is disposed on the side of the passage communicating with the fuel tank of the casing and has a portion that contacts and separates from the negative pressure valve seat. The other of the main body and the cap has a spring seat that is disposed inside the positive pressure valve and supports one end of the spring for the negative pressure valve.

  In the check valve of the present invention, the main body of the negative pressure valve has a spring seat that is arranged inside the positive pressure valve and receives one end of the spring for the negative pressure valve, and the shaft portion of the main body is connected to the positive pressure valve. The negative pressure valve main body is inserted into the through-passage from the inside and protrudes from the opening on the communication passage side to the fuel tank, and the negative pressure valve cap contacts and separates from the negative pressure valve seat. It is preferable that the negative pressure valve is assembled to the positive pressure valve by engaging the shaft portion protruding from the mounting hole formed in the cap.

  In the check valve of the present invention, the negative pressure valve is formed with a negative pressure flow path that communicates the outside of the fuel tank and the inside of the fuel tank when the negative pressure valve main body of the negative pressure valve is separated from the negative pressure valve seat. The negative pressure flow path is preferably configured to pass through the inside of the negative pressure valve spring.

  In the check valve according to the present invention, the casing includes a casing body having a passage communicating with the fuel tank and a positive pressure valve seat formed in the passage, and is assembled to the casing body to form the valve chamber. And a sub casing having a passage communicating with the outside of the fuel tank, and a rib-like spring seat supporting one end of the positive pressure valve spring is formed in the sub-casing, the rib-like spring It is preferable that the central part of the seat protrudes toward the passage communicating with the fuel tank of the casing and enters the inside of the positive pressure valve and the positive pressure valve spring.

  According to the present invention, the shaft portion formed in the main body of the negative pressure valve is inserted into the opening on the side of the communication passage to the fuel tank formed in the positive pressure valve, and this shaft portion is formed in the cap of the negative pressure valve. The negative pressure valve can be assembled to the positive pressure valve by being inserted into and engaged with the mounting hole. At this time, the main body and the cap can be attached by a simple operation by simply inserting the shaft portion protruding from the center of one end of the main body into the mounting hole formed at the center of the cap. Assembling workability of the pressure valve can be improved.

  Further, one of the main body and the cap is provided with a portion arranged on the side of the passage communicating with the inside of the fuel tank of the casing and coming into contact with and separating from the negative pressure valve seat, and the other of the main body or the cap has Since the spring seat which is disposed inside the positive pressure valve and receives one end of the negative pressure valve spring is provided, the negative pressure valve spring is biased by the negative pressure valve spring so as to contact the negative pressure valve seat.

  Therefore, in this check valve, the positive pressure valve is normally brought into contact with the positive pressure valve seat by the positive pressure valve spring, and the portion that is in contact with and separated from the negative pressure valve seat is brought into contact with the negative pressure valve seat by the negative pressure valve spring, The passage communicating with the tank is closed, but when the pressure in the fuel tank exceeds the predetermined value, the positive pressure valve slides against the biasing force of the positive pressure valve spring and moves away from the positive pressure valve seat. Since the fuel vapor and the like in the fuel flow out of the tank through the positive pressure valve seat in the casing, it is possible to suppress the pressure in the fuel tank from exceeding a predetermined value. On the other hand, when the pressure in the fuel tank becomes a negative pressure below a predetermined value, the negative pressure valve moves away from the negative pressure valve seat against the biasing force of the negative pressure valve spring, and air outside the fuel tank passes through the negative pressure valve seat. Therefore, the pressure in the fuel tank can be suppressed from becoming a predetermined value or less.

It is a disassembled perspective view which shows one Embodiment of the check valve of this invention. It is a principal part expanded sectional view of the check valve. It is a bottom view of the positive pressure valve which comprises the check valve. It is the perspective view which looked at the main body which constitutes a negative pressure valve from the slanting upper part in the check valve. The main body is shown, (a) is the perspective view seen from diagonally downward, (b) is a bottom view. It is a perspective view which shows the 1st process when attaching a negative pressure valve to a positive pressure valve in the check valve. It is a perspective view which shows the 2nd process when attaching a negative pressure valve to a positive pressure valve in the check valve. FIG. 4 is an enlarged cross-sectional view of a main part showing a state in which the pressure in the fuel tank becomes a predetermined value or more in the check valve. FIG. 4 is an enlarged cross-sectional view of a main part showing a state in which the pressure in the fuel tank is a negative pressure that is equal to or less than a predetermined value compared to the external air pressure in the check valve. It is a disassembled perspective view which shows other embodiment of the check valve | bulb of this invention. It is a principal part expanded sectional view of the check valve. It is a bottom view of the positive pressure valve which comprises the check valve. In the check valve, a cap constituting a negative pressure valve is shown, (a) is a perspective view seen from diagonally above, and (b) is a perspective view seen from diagonally below. It is a bottom view of the cap. It is a perspective view which shows the 1st process when attaching a negative pressure valve to a positive pressure valve in the check valve. It is a perspective view which shows the 2nd process when attaching a negative pressure valve to a positive pressure valve in the check valve. FIG. 4 is an enlarged cross-sectional view of a main part showing a state in which the pressure in the fuel tank becomes a predetermined value or more in the check valve. FIG. 4 is an enlarged cross-sectional view of a main part showing a state in which the pressure in the fuel tank is a negative pressure that is equal to or less than a predetermined value compared to the external air pressure in the check valve.

  Hereinafter, an embodiment of the check valve of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the check valve 1 includes a casing body 11 and a subcasing 20, and a casing 10 having a valve chamber V formed therein, and can be slid into the valve chamber V of the casing 10. A positive pressure valve 30 accommodated in the positive pressure valve 30, a negative pressure valve 50 assembled to the positive pressure valve 30, a positive pressure valve spring S1 for biasing the positive pressure valve 30 so as to abut on a positive pressure valve seat 15 described later, and a negative pressure valve 50. And a negative pressure valve spring S2 that urges the negative pressure valve seat 37 to be in contact with the negative pressure valve seat 37 described later.

  As shown in FIG. 2, the casing body 11 includes a cylindrical tube body 12 having a connecting pipe 13 integrally extending at one end and the sub casing 20 assembled at the other end opening. Yes. A pipe communicating with the inside of the fuel tank is connected to the outer periphery of the connecting pipe 13, and the inside of the connecting pipe 13 forms a communication path 14 to the fuel tank. Further, the inner periphery of the base end portion of the connection pipe 13 forms a positive pressure valve seat 15 to which the positive pressure valve 30 contacts and separates. Further, an annular flange portion 16 is formed on the outer periphery of the other end opening of the cylindrical body 12, and an annular recess 16a is provided on the end surface of the flange portion 16 on the subcasing 20 side.

  On the other hand, the sub casing 20 is assembled to the other end opening of the cylindrical body 12 of the casing body 11, and a disc-shaped lid 21 having an opening 22 communicating with the outside of the fuel tank at the center thereof, A connecting pipe 23 extending from the outer peripheral edge of the opening 22. An external pipe (not shown) connected to a canister or the like disposed outside the fuel tank is connected to the outer periphery of the connection pipe 23.

  The inner peripheral surface of the opening portion 22 is a tapered surface 22a that gradually spreads from the connecting pipe 23 toward the valve chamber V side, and a rib shape that supports one end of the positive pressure valve spring S1 on the tapered surface 22a. The spring seat 24 is provided. The spring seats 24 are arranged at the center of the opening 22 with a plurality of ribs 25 erected from the taper surface 22 a at equal radial intervals from the center of the opening 22. It is comprised from the column-shaped connection part 26 which connects mutually.

  On the outer periphery of each rib 25, a step portion 25a for supporting one end of the positive pressure valve spring S1 is formed. Further, the front end surface 25 b of each rib 25 is formed so as to gradually become higher toward the center of the opening 22. As a result, when the central portion of the rib-shaped spring seat 24 protrudes toward the communication passage 14 to the fuel tank of the casing 10 and one end of the positive pressure valve spring S1 is supported by the step portion 25a. The positive pressure valve spring S1 enters the inside. Further, an annular convex portion 27 that engages with the annular concave portion 16 a of the flange portion 16 of the casing main body 11 protrudes from a slightly inner side than the outer peripheral edge of the lid body 21.

  The positive pressure valve 30 disposed in the valve chamber V of the casing 10 has a cylindrical shape having a through passage 31 therein. The outer periphery on the front end side of the positive pressure valve 30 forms an inclined surface 35 that gradually decreases in diameter toward the front end, and this inclined surface 35 is a portion that contacts and separates from the positive pressure valve seat 15 of the casing 10. In addition, an opening 31a of the through passage 31 is formed at the center of the front end side wall portion of the positive pressure valve 30, and the periphery thereof is inclined so as to gradually increase toward the outer peripheral direction. It is a negative pressure valve seat 37 that contacts and separates.

  Further, as shown in FIGS. 2 and 3, a cylindrical shaft holding portion 39 protrudes from the rear peripheral edge of the opening 31 a of the positive pressure valve 30, and is provided on the outer periphery of the base end portion of the shaft holding portion 39. A stepped negative pressure spring support portion 41 that supports the other end of the negative pressure valve spring S2 is formed. Furthermore, an annular positive pressure spring support portion 43 that supports the other end of the positive pressure valve spring S1 is provided in the middle of the inner circumference of the positive pressure valve 30 in the axial direction. From the inner peripheral edge of the positive pressure spring support portion 43, a plurality of spring support ribs 45 that enter the inside of the positive pressure valve spring S <b> 1 are provided at equal intervals in the circumferential direction.

  Further, a plurality of guide ribs 47 are extended along the axial direction on the outer periphery on the proximal end side of the positive pressure valve 30 with radial equal intervals, and when the positive pressure valve 30 slides in the valve chamber V In addition, a gap is secured between the inner periphery of the cylindrical body 12 of the casing body 11 and the outer periphery of the positive pressure valve 30 to constitute a flow path through which fuel vapor and the like are circulated.

  One end of the positive pressure valve spring S1 is supported by the step portion 25a of the rib-shaped spring seat 24 of the sub casing 20, and the other end is supported by the positive pressure spring support portion 43 of the positive pressure valve 30. 10 is arranged in a compressed state between the inner circumference of the positive pressure valve 30 and the inner circumference of the positive pressure valve 30, the positive pressure valve 30 is biased toward the positive pressure valve seat 15 of the casing 10, and its inclined surface 35 is directed to the positive pressure valve seat 15. It always comes into contact (see FIG. 2). When the pressure in the fuel tank rises above a predetermined value, the positive pressure valve 30 is pressed by the fuel vapor and slides in the valve chamber V, so that the inclined surface 35 of the positive pressure valve 30 is moved to the positive pressure valve seat 15. (See FIG. 8).

  The negative pressure valve 50 assembled to the positive pressure valve 30 having the above structure is composed of a main body 51 and a cap 60 attached to the main body 51. In this embodiment, a cap 60 is arranged on the side of the communication path 14 to the fuel tank of the casing 10, and a main body 51 is arranged inside the positive pressure valve 30.

  As shown in FIGS. 4 and 5, the main body 51 includes a shaft portion 52, a cylindrical wall 53 disposed with a predetermined gap around the base end outer periphery of the shaft portion 52, and a circumferential direction of the shaft portion 52. A plurality of them are arranged at equal intervals, and are mainly composed of ribs 54 that connect the coaxial portion 52 and the cylindrical wall 53.

  On the distal end side of the shaft portion 52, a reduced diameter portion 52a that gradually decreases in diameter toward the distal end of the shaft portion, an insertion portion 52b that extends with a constant diameter from the distal end of the reduced diameter portion 52a, and a continuous connection to the insertion portion 52b. In addition, an engagement protrusion 52c having a diameter slightly larger than that of the insertion portion 52b is provided. The outer periphery of the engaging protrusion 52c has a rounded shape. Further, a taper surface 52d that gradually decreases in diameter toward the base end of the shaft portion 52 is formed from the middle of the shaft portion 52 in the axial direction, and each rib 54 is connected to the taper surface 52d.

  As shown in FIGS. 2 and 5 (a), the base-side inner peripheral surface 54a of each rib 54 has a shape inclined so as to gradually decrease in height toward the base end opening of the cylindrical wall 53. ing. An annular spring seat 56 that supports one end of the negative pressure valve spring S <b> 2 protrudes from the outer peripheral edge of the proximal end of the cylindrical wall 53.

  When the pressure between the ribs 54 and 54 is between the outer periphery of the shaft portion 52 and the inner periphery of the cylindrical wall 53, the pressure in the fuel tank is reduced below a predetermined value from the external pressure. In addition, a negative pressure channel 58 for circulating the outside air introduced from the outside of the fuel tank is formed (see FIG. 2). In this embodiment, since one end of the negative pressure valve spring S2 is supported by the spring seat 56 protruding from the outer periphery of the cylindrical wall 53, the negative pressure flow path 58 passes through the inside of the negative pressure valve spring S2. It is configured as follows.

  On the other hand, the cap 60 has a cylindrical shape in which an attachment hole 61 is formed at the center of the tip, and an outer peripheral surface 65 that is gradually enlarged in diameter toward the base end is formed. An opening 63 into which the distal end side of the portion 52 is inserted is formed (see FIGS. 1, 2 and 7).

  An inclined surface 61 a that gradually increases in diameter toward the base end side is formed from the inner peripheral surface of the cap 60 from the rear peripheral edge of the mounting hole 61, and comes into contact with the reduced diameter portion 52 a of the shaft portion 52. It is like that. An insertion portion 52b of the shaft portion 52 is inserted into the mounting hole 61, and an engagement protrusion 52c of the main body 51 is engaged with the front peripheral edge thereof.

  The outer peripheral surface 65 is formed at substantially the same inclination angle as the inclined surface 35 of the positive pressure valve 30 (see FIG. 2). Furthermore, the outer peripheral surface 65a on the base end side of the cap 60 is reduced in diameter toward the base end side from the top portion 65b having the largest diameter, and is a portion that contacts and separates from the negative pressure valve seat 37 of the positive pressure valve 30. (See FIGS. 8 and 9).

  One end of the negative pressure valve spring S2 is supported by the spring seat 56 of the main body 51 of the negative pressure valve 50, and the other end is supported by the negative pressure spring support portion 41 of the positive pressure valve 30. The negative pressure valve 50 is urged toward the positive pressure valve 30, and the outer peripheral surface 65 a on the base end side of the cap 60 always comes into contact with the negative pressure valve seat 37 of the positive pressure valve 30. (See FIG. 2).

  When the pressure in the fuel tank drops below a predetermined value below the atmospheric pressure, the negative pressure valve 50 is pressed by the outside air and slides against the positive pressure valve 30 against the biasing force of the negative pressure valve spring S2. In operation, the outer peripheral surface 65a of the negative pressure valve 50 is separated from the negative pressure valve seat 37 (see FIG. 9). As a result, outside air from the outside of the fuel tank flows in from the proximal end opening of the cylindrical wall 53, passes through the negative pressure passage 58, and between the outer peripheral surface 65 a of the negative pressure valve 50 and the negative pressure valve seat 37. It flows out into the communication passage 14 to the fuel tank (see FIG. 9).

  Next, an example of the assembly process of the check valve 1 having the above configuration will be described. First, as shown in FIG. 6, the shaft portion 52 of the main body 51 is inserted into the inner periphery of one end of the negative pressure valve spring S2, and the negative pressure valve spring S2 is disposed on the outer periphery of the main body 51 of the negative pressure valve 50. One end of the pressure valve spring S <b> 2 is supported by the spring seat 56 of the main body 51.

  Thereafter, the main body 51 is inserted into the through passage 31 of the positive pressure valve 30, the shaft portion 52 is protruded from the opening portion 31a through the shaft holding portion 39 of the positive pressure valve 30, and the reduced diameter portion 52a and the engaging protrusion portion 52c are opened. The shaft holding portion 39 of the positive pressure valve 30 is inserted into the inner periphery of the other end of the negative pressure valve spring S2, and the other end of the negative pressure valve spring S2 is connected to the positive pressure valve. 30 is supported by the negative pressure spring support 41 (see FIG. 2).

  While maintaining the above state, as shown in FIG. 7, the mounting hole 61 is aligned with the shaft portion 52, the cap 60 is pressed toward the main body 51, and the engaging protrusion 52 c of the shaft portion 52 is moved to the mounting hole. Press fit into 61 and project from the front side of the mounting hole 61. As a result, the insertion portion 52b of the shaft portion 52 is inserted into the mounting hole 61, the reduced diameter portion 52a of the shaft portion 52 abuts on the inclined surface 61a on the back side of the mounting hole, and the shaft portion 52 on the front peripheral edge of the mounting hole 61. The cap 60 is attached to the main body 51 and the negative pressure valve spring S2 in a state where the engaging protrusions 52c are engaged and the front and back sides of the mounting hole 61 are sandwiched between the engaging protrusions 52c and the reduced diameter part 52a. Can be slidably assembled to the positive pressure valve 30 (see FIG. 2).

  Thus, in this check valve 1, like the check valve of the said patent document 1, after aligning the several leg part of a negative pressure valve to the several through-hole of a positive pressure valve, respectively, it inserts, There is no need to engage the engaging protrusions on the outer periphery of the cap with the engaging holes, and the simple operation of simply inserting the shaft portion 52 provided on the main body 51 into one mounting hole 61 formed at the center of the cap 60. Since the main body 51 and the cap 60 can be attached, the workability of assembling the negative pressure valve 50 with respect to the positive pressure valve 30 can be improved.

  In particular, in the present embodiment, as shown in FIG. 7, the shaft portion 52 of the main body 51 constituting the negative pressure valve 50 is inserted into the through passage 31 from the inside of the positive pressure valve 30 and protrudes from the opening portion 31 a. Since the mounting hole 61 of the cap 60 is engaged with the protruding shaft portion 52, the mounting operation of the main body 51 and the cap 60 can be performed while confirming the state in which the shaft portion 52 protrudes from the opening 31a. This can be done more reliably.

  In this embodiment, the engagement protrusion 52 c of the shaft portion 52 is press-fitted into the attachment hole 61 of the cap 60, so that the reduced-diameter portion 52 a abuts on the rear side periphery of the attachment hole 61, and Since the engaging protrusion 52c engages with the front peripheral edge, the cap 60 can be easily attached to the main body 51 with one touch without using an adhesive or the like, and the attachment workability can be further improved.

  After the two valves are assembled and integrated as described above, the negative pressure valve 50 side is accommodated and arranged toward the communication passage 14 side of the casing body 11 to the fuel tank.

  At the same time, the spring seat 24 of the sub-casing 20 is inserted into the inner periphery of one end of the positive pressure valve spring S 1, and one end of the positive pressure valve spring S 1 is connected to the step portion 25 a on the outer periphery of each rib 25 constituting the spring seat 24. To support. At this time, in this embodiment, the front end surface 25b of each rib 25 constituting the rib-shaped spring seat 24 is gradually formed higher toward the center of the opening 22 of the sub casing 20, and the rib-shaped spring seat 24 is formed. Since the central portion of the spring 10 protrudes toward the communication passage 14 to the fuel tank of the casing 10, each rib 25 of the spring seat 24 is prevented from being caught in the gap between the wires of the positive pressure valve spring S <b> 1. The positive pressure valve spring S1 can be arranged smoothly.

  Further, the spring support rib 45 of the positive pressure valve 30 is inserted into the inner circumference of the other end of the positive pressure valve spring S1, and the other end of the positive pressure valve spring S1 is supported by the positive pressure spring support portion 43. In this state, the sub casing 20 is pressed against the casing main body 11 against the biasing force of the positive pressure valve spring S1, and the annular convex portion 27 of the sub casing 20 is engaged with the annular concave portion 16a of the casing main body 11, The sub casing 20 can be assembled to the casing body 11 by joining the peripheral edges of the engaging portions to each other by means such as ultrasonic welding or adhesive.

  In this embodiment, the cap 60 is attached after the shaft portion 52 of the main body 51 protrudes from the opening 31a. However, the outer peripheral surface 65a of the cap 60 is brought into contact with the negative pressure valve seat 37 of the positive pressure valve 30. Then, the cap 60 is disposed outside the positive pressure valve 30, and then the main body 51 with the negative pressure valve spring S <b> 2 mounted on the positive pressure valve 30 is inserted, and the shaft portion 52 is attached to the mounting hole of the cap 60. The main body 51 and the cap 60 may be attached by engaging with 61. In this embodiment, the main body 51 and the cap 60 are attached by press-fitting the engaging protrusion 52c of the shaft portion 52 into the attachment hole 61. However, both of them are attached by means such as adhesive or welding. Also good.

  Next, the function and effect of the check valve 1 having the above configuration will be described.

  This check valve 1 is connected to the connecting pipe 13 of the casing body 11 by a pipe disposed in the fuel tank and connected to a cut valve or the like, and is connected to the connecting pipe 23 of the sub casing 20 outside the fuel tank. A pipe connected to a canister or the like is connected, and is disposed inside or outside the fuel tank by a clip or a bracket (not shown).

  When the pressure in the fuel tank is below a predetermined value, the inclined surface 35 of the positive pressure valve 30 biased by the biasing force of the positive pressure valve spring S1 contacts the positive pressure valve seat 15 as shown in FIG. Thus, the communication passage 14 to the fuel tank is closed, and the main body 51 urged by the urging force of the negative pressure valve spring S2 and the outer peripheral surface 65a of the cap 60 integrally connected thereto are negative pressure valve seats 37. The opening 31a of the through passage 31 is closed.

  When the pressure in the fuel tank rises to a predetermined value or more in the above state, fuel vapor or the like passes through the communication passage 14 to the fuel tank, the positive pressure valve 30 is pressed, and the positive pressure valve spring S1 as shown in FIG. The positive pressure valve 30 slides toward the sub-casing 20 against the biasing force, and the inclined surface 35 of the positive pressure valve 30 moves away from the positive pressure valve seat 15. Then, as shown by the arrow in FIG. 8, the fuel vapor flows between the inner periphery of the casing body 11 and the outer periphery of the positive pressure valve 30, and between the ribs 25, 25 of the spring seat 24 of the sub casing 20. And flows along the tapered surface 22a and flows into the opening 22 and is sent to the canister and the like through the connecting pipe 23 and a pipe (not shown) to be discharged out of the fuel tank, thereby reducing the pressure in the fuel tank. Can be made.

  At this time, since the fuel vapor or the like passes outside the positive pressure valve spring S1 and flows away from the positive pressure valve spring S1, the positive pressure valve spring S1 is prevented from becoming an obstacle when the fuel vapor or the like passes, Fuel vapor and the like can be smoothly discharged out of the fuel tank, and vibration and swinging of the positive pressure valve 30 urged by the positive pressure valve spring S1 can be suppressed, so that the sliding operation in the valve chamber V can be performed. The operating noise can be reduced.

  On the other hand, when the pressure in the fuel tank drops below a predetermined value with respect to the outside air pressure, it passes between the opening 22 and the ribs 25 of the spring seat 24 through the connection pipe 23 on the sub casing 20 side, Outside air is introduced into the valve chamber V of the casing 10. Then, the negative pressure valve 50 is pressed by the external air pressure, and the negative pressure valve 50 moves toward the communication passage 14 side of the casing body 11 to the fuel tank against the urging force of the negative pressure valve spring S2, as shown in FIG. The outer peripheral surface 65 a on the base end side of the cap 60 of the negative pressure valve 50 is separated from the negative pressure valve seat 37 of the positive pressure valve 30. Then, as shown by the arrows in FIG. 9, outside air flows in from the proximal end opening of the cylindrical wall 53 of the main body 51, and between the outer periphery of the shaft portion 52 and the inner periphery of the cylindrical wall 53, the rib 54, 54 flows along the tapered surface 52d (see FIGS. 5 and 9) of the shaft portion 52 while passing through the negative pressure flow path 58 defined between the flow passages 54 and into the shaft holding portion 39 of the positive pressure valve 30. In addition, from the gap between the outer peripheral surface 65a of the cap 60 and the negative pressure valve seat 37, it passes through the communication passage 14 to the fuel tank, flows into the fuel tank via a pipe (not shown), and the pressure in the fuel tank is reduced. Can be raised.

  In this embodiment, the negative pressure flow path 58 as described above is formed in the negative pressure valve 50, and the negative pressure flow path 58 is configured to pass through the inside of the negative pressure valve spring S2. Since the outside air flows through the inside of the negative pressure valve spring S2, the inflow resistance of the outside air can be reduced and smoothly introduced into the fuel tank, and the negative pressure state in the fuel tank can be quickly eliminated. be able to. Further, the vibration and swinging of the negative pressure valve 50 biased by the negative pressure valve spring S2 can be suppressed, and the operating noise during the sliding operation can be reduced. Furthermore, since the negative pressure valve spring S2 is disposed on the outer periphery of the negative pressure flow path 58, the spring diameter of the negative pressure valve spring S2 can be increased, and a stable spring load can be applied.

  10-18 show another embodiment of the check valve of the present invention. Portions that are substantially the same as those of the above embodiment are given the same reference numerals, and descriptions thereof are omitted.

  As shown in FIG. 10, the check valve 1a of this embodiment includes a casing 10a including a casing main body 11a and a sub casing 20a, a positive pressure valve 30a, and a negative pressure valve 50a including a main body 70 and a cap 80. .

  As shown in FIG. 11, the casing main body 11 a is provided with an annular positive pressure valve seat 15 a protruding from the inner periphery of the proximal end portion of the connection pipe 13. Moreover, the connection part 26a which connects the some rib 25 of the spring seat 24 provided in the subcasing 20a has comprised the cylindrical shape.

  Moreover, the positive pressure valve 30a has a diameter larger than that of the small-diameter cylindrical portion 32 connected to the small-diameter cylindrical portion 32 disposed on the distal end side through a wall portion having an inclined surface 35 at the proximal end of the small-diameter cylindrical portion 32. The large-diameter cylindrical portion 33 is formed into a cylindrical shape (see FIG. 15). Note that guide ribs 47 are provided on the outer circumferences of the small diameter cylindrical portion 32 and the large diameter cylindrical portion 33, respectively.

  Further, the periphery of the opening 31a of the through passage 31 formed inside the positive pressure valve 30a is a wall portion orthogonal to the axial center of the positive pressure valve 30a, and an annular negative pressure valve is formed from the front peripheral edge of the wall portion. A seat 37a is projected. Further, as shown in FIG. 11, an annular protrusion-shaped shaft holding portion 39a is projected from the rear side periphery of the opening portion 31a of the positive pressure valve 30a, and the outer periphery thereof forms a negative pressure spring support portion 41. .

  Further, as shown in FIGS. 11 and 12, a plurality of spring support ribs 45a are vertically provided at equal intervals in the circumferential direction inside the positive pressure valve 30a and on the outer periphery of the negative pressure spring support portion 41. ing. Each spring support rib 45a is extended from the back side of the tip wall portion of the positive pressure valve 30a beyond the positive pressure spring support portion 43 on the inner periphery of the positive pressure valve (see FIG. 11), and inside the positive pressure valve spring S1. The positive pressure valve spring S1 is inserted and supported on the outside of the negative pressure valve spring S2 and the outer periphery of the cap 80 to guide the sliding operation of the negative pressure valve 50a.

  The negative pressure valve 50a assembled to the positive pressure valve 30a includes a main body 70 disposed on the side of the communication passage 14 to the fuel tank of the casing 10a, and a cap 80 disposed inside the positive pressure valve 30a. .

  As shown in FIGS. 11 and 16, the main body 70 includes a head 71 that contacts and separates from the negative pressure valve seat 37 a of the positive pressure valve 30 a, a shaft portion 73 that extends from the head 71, and the shaft portion 73. And an engaging projection 75 formed at the tip of the.

  The head 71 has a shape in which the top of the top is rounded, and the outer periphery of the head 71 extends in an umbrella shape obliquely outward, and the contact portion 71a on the back side of the base end is The positive pressure valve 30a contacts and separates from the negative pressure valve seat 37 (see FIGS. 17 and 18). The shaft 73 is suspended from the center of the back side of the head 71 by a predetermined length, and the tip thereof is reduced in diameter to form a recess 73a. A hemispherical shape is formed at the end of the recess 73a. An engaging protrusion 75 is provided continuously.

  Further, a plurality of guide ribs 77 are extended along the axial direction at a predetermined length on the outer periphery of the shaft portion 73 in a radial manner, and guide the slide operation of the negative pressure valve 50. A flow path 78 is formed to ensure a gap between the outer periphery of the shaft portion 73 and the inner periphery of the opening portion 31a of the positive pressure valve 30 (see FIG. 18).

  As shown in FIGS. 13 and 14, the cap 80 attached to the main body 70 has an annular portion 81 and an annular shape having a diameter larger than that of the annular portion 81, and is concentric with a predetermined interval from the annular portion 81. And an annular spring seat 82 supporting one end of the negative pressure valve spring S2, one end connected to the annular portion 81, and the other end connected to the spring seat 82, the annular portion 81 and the spring seat. 82, and a plurality of connecting walls 83 arranged at equal intervals in the circumferential direction.

  As shown in FIG. 13A, a plurality of gaps 84 are formed between the annular portion 81 and the spring seat 82 and between the connecting walls 83, 83. A plurality of engaging claws 85 are formed inside the cap 80 via the.

  Each engagement claw 85 has a proximal end connected to the inner periphery of the annular portion 81, a distal end extending toward the axial center of the cap 80, and is surrounded by distal ends 85 a of the plurality of engagement claws 85. The portion forms a mounting hole 86 in the present invention (see FIG. 14). As shown in FIG. 14, both sides of each engagement claw 85 are gradually narrowed toward the inner circumferential direction of the cap 80, and the distal end surface of the distal end portion 85 a has an arc shape. And the front-end | tip part 85a of each engagement nail | claw 85 enters into the hollow part 73a of the axial part 73 of the said main body 70, while an arc-shaped front end surface contact | abuts the outer periphery of the hollow part 73a, the said engagement protrusion 75 (See FIG. 11).

  Moreover, when the main body 70 and the cap 80 are attached to the gap between the engaging claws 85, 85, a gap is secured between the outer periphery of the main body 70 and the inner periphery of the cap 80 to allow the outside air to circulate. A flow path 88 is formed (see FIG. 18). This flow path 88 and the flow path 78 between the above-mentioned guide ribs 77, 77 constitute a negative pressure flow path in the present invention, and this negative pressure flow path is disposed so as to pass inside the negative pressure valve spring S2. (See FIG. 18).

  The check valve 1a having the above structure can be mounted as follows, for example. That is, as shown in FIG. 15, the cap 80 is inserted into the inner periphery of one end of the negative pressure valve spring S2, and one end of the negative pressure valve spring S2 is supported by the spring seat 82, and then the cap 80 is attached to the positive pressure valve 30a. It arrange | positions inside the some spring support rib 45a, and supports the other end of the spring S2 for negative pressure valves with the negative pressure spring support part 41 (refer FIG. 11).

  In this state, as shown in FIG. 16, the shaft portion 73 of the main body 70 is inserted and pushed in from the opening 31a of the positive pressure valve 30a. Then, the front end portion 85a of the engagement claw 85 of the cap 80 is pushed and expanded by the engagement protrusion 75 of the main body 70, and when the front end portion 85a reaches the recessed portion 73a of the shaft portion 73, the engagement claw 85 is After the elastic return, the distal end portion 85a enters the recessed portion 73a, engages with the engaging protrusion 75, and the shaft portion 73 is inserted into the mounting hole 86 surrounded by the distal end portions 85a of the plurality of engaging claws 85. Engage. As a result, the main body 70 and the cap 80 are attached, the negative pressure valve spring S2 is held in a compressed state, and the negative pressure valve 50a can be slidably assembled to the positive pressure valve 30a.

  Also in this embodiment, the main body 70 and the cap 80 can be attached by a simple operation by simply inserting the shaft portion 73 of the main body 70 into the attachment hole 86 of the cap 80. Assembling workability of the negative pressure valve 50a with respect to the pressure valve 30a can be improved. Not limited to the above assembly method, the shaft portion 73 of the main body 70 is inserted from the opening 31a of the positive pressure valve 30a, and the shaft portion 73 protrudes into the positive pressure valve 30a, and then the negative pressure valve spring S2 is packaged. The main body 70 and the cap 80 may be attached by inserting the cap 80 and engaging the shaft portion 73 with the attachment hole 86.

  The inclined surface 35 of the positive pressure valve 30a contacts the positive pressure valve seat 15a, the communication passage 14 to the fuel tank is closed, and the contact portion 71a of the main body 70 contacts the negative pressure valve seat 37a of the positive pressure valve 30a. In contact with the opening 31a of the through-passage 31 (see FIG. 11), when the pressure in the fuel tank rises to a predetermined value or higher, fuel vapor or the like passes through the communication passage 14 to the fuel tank, When the pressure valve 30a is pressed, the positive pressure valve 30a slides toward the sub casing 20a against the biasing force of the positive pressure valve spring S1, and the inclined surface 35 of the positive pressure valve 30a is positive pressure valve seat 15 as shown in FIG. Get away from. Then, as shown by the arrows in FIG. 17, fuel vapor or the like flows between the inner periphery of the casing body 11a and the outer periphery of the positive pressure valve 30a, and between the ribs 25, 25 of the spring seat 24 of the sub casing 20a. And flows along the tapered surface 22a to flow into the opening 22 and is sent to the canister or the like through the connecting pipe 23 and a pipe (not shown) to be discharged out of the fuel tank. Can be reduced.

  On the other hand, when the pressure in the fuel tank decreases to a predetermined value or less with respect to the external air pressure, it passes through the connecting portion 23 on the sub casing 20a side and passes through the cylindrical connecting portion 26a in the center of the opening 22 and the spring seat 24. Then, outside air is introduced into the valve chamber V of the casing 10a. Then, the negative pressure valve 50a is pressed by this external air pressure, and as shown in FIG. 18, the negative pressure valve 50a moves against the urging force of the negative pressure valve spring S2 toward the communication passage 14 side of the casing body 11a to the fuel tank. It slides and the contact part 71a of the main body 70 separates from the negative pressure valve seat 37a. Then, as shown by the arrows in FIG. 18, the outside air flows into the inner periphery of the annular spring seat 82 of the cap 80, and the flow path 88 between the engaging claws 85, 85 and the flow path between the guide ribs 77, 77. 78 flows through the negative pressure flow path 78, flows out from the opening 31a of the positive pressure valve 30a, passes through the communication passage 14 to the fuel tank from the gap between the contact portion 71a of the main body 70 and the negative pressure valve seat 37a, It flows into the fuel tank through a pipe (not shown), and the pressure in the fuel tank can be increased.

DESCRIPTION OF SYMBOLS 1 Check valve 1, 1a Check valve 10, 10a Casing 11, 11a Casing main body 14 Communication path 15 to fuel tank 15, 15a Positive pressure valve seat 20, 20a Sub casing 24 Spring seat 30, 30a Positive pressure valve 31 Through passage 31a Opening 37 , 37a Negative pressure valve seat 50, 50a Negative pressure valve 51 Main body 52 Shaft portion 56 Spring seat 58 Negative pressure flow path 60 Cap 61 Mounting hole 70 Main body 73 Shaft portion 80 Cap 82 Spring seat 86 Mounting hole S1 Positive pressure valve spring S2 Negative pressure valve spring V valve chamber

Claims (4)

A casing having one end connected to the inside of the fuel tank, the other end connected to the outside of the fuel tank, the inside forming a valve chamber, and a positive pressure valve seat formed in a passage connected to the inside of the fuel tank;
The valve chamber is slidably disposed, and is urged to contact the positive pressure valve seat by a positive pressure valve spring disposed in the casing, and has a through passage that penetrates the inside thereof. A positive pressure valve in which a negative pressure valve seat is formed at the opening on the communication path side to the fuel tank of the road;
A negative pressure valve assembled to the positive pressure valve so as to open and close the negative pressure valve seat of the positive pressure valve and biased to abut against the negative pressure valve seat by a negative pressure valve spring disposed in the positive pressure valve; With
The negative pressure valve has a main body having a shaft projecting from the center of one end, and a cap formed around a mounting hole into which the shaft is inserted and engaged,
One of the main body or the cap has a portion arranged on the side of the passage communicating with the inside of the fuel tank of the casing and is in contact with or separated from the negative pressure valve seat, and the other of the main body or the cap is the positive electrode. A check valve comprising a spring seat disposed inside the pressure valve and supporting one end of the negative pressure valve spring.   The main body of the negative pressure valve has a spring seat disposed inside the positive pressure valve to receive one end of the negative pressure valve spring, and the shaft portion of the main body is inserted into the through passage from the inside of the positive pressure valve. The negative pressure valve main body protruding from the opening on the communication passage side to the fuel tank, and the cap of the negative pressure valve contacting and separating from the negative pressure valve seat, and the shaft protruding from the opening, The check valve according to claim 1, wherein the negative pressure valve is assembled to the positive pressure valve by engaging with a mounting hole formed in the cap.   When the negative pressure valve body of the negative pressure valve is separated from the negative pressure valve seat, the negative pressure valve is formed with a negative pressure passage that communicates between the outside of the fuel tank and the inside of the fuel tank. The check valve according to claim 1, wherein the check valve is configured to pass through an inside of the negative pressure valve spring.   The casing has a passage communicating with the inside of the fuel tank and a positive pressure valve seat formed in the passage, and is assembled to the casing body to form the valve chamber and communicates with the outside of the fuel tank. A rib-like spring seat that supports one end of the positive pressure valve spring is formed in the sub-casing, and a central portion of the rib-shaped spring seat is formed in the casing. The check valve according to any one of claims 1 to 3, wherein the check valve protrudes toward a passage communicating with a fuel tank and enters the positive pressure valve and the positive pressure valve spring.