JP2005081862A - Fuel cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a flow rate characteristic at the time of opening a positive pressure valve 60 of a pressure regulating valve 50 provided within a fuel cap 10. <P>SOLUTION: A regulating valve is provided with the positive pressure valve 60 and a negative pressure valve 70. The positive pressure valve 60 has a positive pressure valve element 61 and a first spring 68. The negative pressure valve 70 is provided with a negative pressure valve element 71 and a second spring 78. A restriction part is formed by an annular projecting part 73c in an outer peripheral part of the negative pressure valve element 71 and at a portion facing to a first valve flow passage 25d. The restriction part narrows flow passage area of the first valve flow passage 25d in a closed valve state of the negative pressure valve element 71 and increases the flow passage area of the first valve flow passage 25d in a state of the negative pressure valve element 71 moving integrally with the positive pressure valve element 61 in accordance with opening of the positive pressure valve element 61. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fuel cap including a pressure regulating valve that regulates the inside of a fuel tank, and more particularly to a mechanism that improves the flow rate characteristics of the pressure regulating valve.

  2. Description of the Related Art Conventionally, a fuel cap of this type includes a cap body that is screwed into an inlet of a fuel tank, and a pressure regulating valve that is attached to the cap body and regulates the pressure in the fuel tank. (For example, patent document 1). The pressure regulating valve is composed of a positive pressure valve and a negative pressure valve.When the tank internal pressure exceeds a predetermined value, the positive pressure valve opens.When the tank internal pressure falls below the predetermined value, the negative pressure valve opens. Is adjusted within a predetermined range.

  The negative pressure valve has a configuration in which a throttle portion is provided in the negative pressure valve body to increase the differential pressure applied to the valve body and to rapidly increase the flow rate when the valve is opened. However, such a throttle portion has a problem that the flow rate at the time of opening the positive pressure valve is reduced and the performance of quickly adjusting the pressure by the positive pressure valve is lowered.

JP-A-10-278958

  An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a fuel cap with improved performance of quickly adjusting the pressure by a positive pressure valve.

The present invention made to solve the above problems
A cap main body mounted in the tank opening of the fuel tank; and a pressure regulating valve that regulates the pressure in the fuel tank by opening and closing a passage in the cap that is housed in the cap main body and formed in the cap main body. In the fuel cap
The pressure regulating valve includes a positive pressure valve that opens when the pressure in the fuel tank becomes higher than a first pressure value, and a negative pressure valve that opens when the pressure in the fuel tank becomes lower than a second pressure value. A pressure valve,
The positive pressure valve includes a positive pressure valve body that opens and closes a first valve flow path that constitutes a part of the flow path in the cap, and is fixed to the cap main body at one end and closes with respect to the positive pressure valve body. A first spring for applying a biasing force of
The positive pressure valve body
A positive pressure valve body;
A seat portion that is formed in the positive pressure valve body, faces the first valve channel and closes the first valve channel by sitting on a first seating portion provided in the cap body;
A second valve flow path formed through the positive pressure valve body and constituting a part of the flow path in the cap;
A second seat formed on the positive pressure valve body and facing the second valve flow path,
The negative pressure valve includes a negative pressure valve body that opens and closes the second valve flow path, a second spring that is fixed to the cap body at the other end and applies a biasing force in a closing direction to the negative pressure valve body; Have
The negative pressure valve body
A cup-shaped negative pressure valve main body formed from an upper wall plate portion and a cylindrical side wall portion protruding from the outer peripheral portion of the upper wall plate portion;
A seat portion formed on the upper wall plate portion and seated on the second seat portion to close the second valve flow path;
Provided at a location facing the first valve flow path, the flow area of the first valve flow path is narrowed when the negative pressure valve body is closed, and the positive pressure valve body is opened as the positive pressure valve body is opened. A throttle portion that increases the flow area of the first valve flow path in a state where the negative pressure valve body is moved integrally with the pressure valve body;
It is characterized by comprising.

  In the fuel cap of the present invention, the inside of the fuel tank is adjusted within a predetermined pressure range by opening and closing the flow path in the cap by the pressure regulating valve. That is, the positive pressure valve opens the positive pressure valve body against the urging force of the first spring when the internal pressure of the fuel tank becomes higher than the first pressure value, and the negative pressure valve has the tank internal pressure of the second pressure. When the pressure becomes smaller than the value, the negative pressure valve body opens, thereby maintaining the internal pressure in the fuel tank within a predetermined range.

  Further, the throttle portion provided in the negative pressure valve body increases the differential pressure applied to the negative pressure valve body at the time of negative pressure to improve the valve opening characteristic. Further, the throttle portion can increase the flow area of the first valve flow path at the time of positive pressure, and can cause the flow rate to flow rapidly. Therefore, the flow rate characteristic of the positive pressure valve is not impaired.

(1) Schematic Configuration of Fuel Cap 10 FIG. 1 is a cross-sectional view showing the fuel cap 10 according to the first embodiment of the present invention. In FIG. 1, a fuel cap 10 is attached to a filler neck FN having an inlet FNb (tank opening) for supplying fuel to a fuel tank (not shown), and a cap body 20 formed of a synthetic resin material such as polyacetal. A lid 40 having an operation portion mounted on the upper portion of the cap body 20 and formed of a synthetic resin material such as nylon; an inner lid 30 that closes the upper opening of the cap body 20 to form the valve chamber 25; The pressure regulation valve 50 accommodated in the chamber 25, a torque mechanism 80, and a gasket GS that is attached to the upper outer periphery of the cap body 20 and seals between the filler neck FN are provided.

  The cap body 20 includes a substantially cylindrical outer tube body 20a having a cap-side engaging portion 21 that is engaged with the inner peripheral portion of the filler neck FN, and the valve chamber provided from the lower portion to the upper portion of the outer tube body 20a. 25 and a valve chamber forming body 20b. The upper portions of the valve chamber forming body 20b and the outer tube body 20a are covered with an inner lid 30 attached to the upper portion of the cap body 20, thereby forming the valve chamber 25. The pressure regulating valve 50 housed in the valve chamber 25 includes a positive pressure valve 60 and a negative pressure valve 70, and adjusts the pressure in the fuel tank within a predetermined range.

  A gasket GS is sheathed on the lower surface of the flange portion 22 at the top of the cap body 20. The gasket GS is interposed between the seal holding portion 24 of the flange portion 22 and the inlet FNb of the filler neck FN. When the fuel cap 10 is tightened into the inlet FNb, the gasket GS is pressed against the seal holding portion 24. To achieve a sealing action. At this time, the operator receives a click feeling when the predetermined rotational torque is exceeded during the operation of closing the fuel cap 10 by the torque mechanism 80, and can confirm that the tightening is performed at a predetermined rotational torque or more.

(2) Configuration of Pressure Regulator 50 FIG. 2 is an enlarged cross-sectional view of the vicinity of the pressure regulator 50. The pressure regulating valve 50 includes a positive pressure valve 60 and a negative pressure valve 70. The positive pressure valve 60 is disposed in the upper chamber 25a of the valve chamber 25, and the negative pressure valve 70 is disposed in the lower chamber 25b. A first seat portion 20f is formed between the upper chamber 25a and the lower chamber 25b and in a portion inclined from the inside of the valve chamber forming body 20b. The first valve channel faces the first seat portion 20f. 25d is formed. The first valve flow path 25d communicates with a communication hole 25c formed in the bottom portion 20d, and the communication hole 25c is connected to a fuel tank through a filler pipe (not shown).

(2) -1 Configuration of Positive Pressure Valve 60 The positive pressure valve 60 is fixed at one end to the positive pressure valve body 61 that opens and closes the first valve flow path 25d, the valve holding member 65, and the inner lid 30, and the valve holding member 65. And a first spring 68 for applying a biasing force in the closing direction to the positive pressure valve body 61.

  FIG. 3 is an exploded cross-sectional view of the pressure regulating valve 50. The positive pressure valve body 61 includes a disc-shaped positive pressure valve main body 62 formed of fluorine rubber or the like, and a through hole or a projection for performing a valve function is formed in the positive pressure valve main body 62. That is, the positive pressure valve main body 62 is formed with a seat portion 63a that closes the first valve flow path 25d by being seated on the first seating portion 20f. The seat portion 63a is thin by forming an annular recess 63b from the outer peripheral upper surface of the positive pressure valve main body 62, and when seated on the first seating portion 20f, the seat portion 63a bends in a pulse shape to improve the sealing performance. Yes. In addition, a second valve channel 63c connected to the first valve channel 25d is formed through the central portion of the positive pressure valve main body 62. Furthermore, a second seating portion 63d is formed on a lower surface of the positive pressure valve main body 62 and facing the second valve flow path 63c. The second seating portion 63d functions as a seating surface of the negative pressure valve 70 as will be described later. An annular groove 63e is formed on the lower surface of the positive pressure valve main body 62 and on the inner peripheral side of the annular recess 63b. The annular groove 63e is a groove for facilitating bending when the positive pressure valve body 61 is closed.

  A cylindrical fitting portion 63f is provided upright at the center of the positive pressure valve body 61 so as to surround the second valve flow path 63c. A side support recess 63g is formed in the side portion of the fitting portion 63f, and the positive pressure valve body 61 is attached to the valve holding member 65 by being inserted into the fitting hole 65a of the valve holding member 65. ing. A spring support portion 65 b is formed on the upper surface of the valve holding member 65, and this spring support portion 65 b supports one end portion of the first spring 68. The other end of the first spring 68 is supported by the cylindrical support portion 30 a of the inner lid 30, so that the first spring 68 is stretched between the spring support portion 65 b and the inner lid 30.

(2) -2 Configuration of Negative Pressure Valve 70 As shown in FIG. 2, the negative pressure valve 70 is spanned between a negative pressure valve body 71 made of resin, and the negative pressure valve body 71 and the bottom portion 20d. And a second spring 78 for urging the spring.

  As shown in FIG. 3, the negative pressure valve body 71 is a cup-shaped negative pressure valve body formed of an upper wall plate portion 72a and a cylindrical side wall portion 72b protruding from the outer peripheral portion of the upper wall plate portion 72a. 72. The negative pressure valve main body 72 is provided with a protrusion or the like for performing a valve function. That is, on the upper wall plate portion 72a of the negative pressure valve main body 72, a seat portion 73a that closes the second valve flow path 63c by being seated on the second seat portion 63d of the positive pressure valve body 61 is formed in a circular mountain shape. . In addition, an annular protrusion 73c is formed at a position on the upper portion of the side wall portion 72b and facing the first valve flow path 25d. The annular protrusion 73 c narrows the flow path area of the first valve flow path 25 d when the negative pressure valve body 71 is closed, and is integrated with the positive pressure valve body 61 as the positive pressure valve body 61 is opened. The throttle part which enlarges the flow-path area of the 1st valve flow path 25d in the state which the said negative pressure valve body 71 moved is comprised.

(3) Operation of the pressure regulating valve 50 In the above configuration, the pressure regulation in the fuel tank by the positive pressure valve 60 is performed by the following operation. That is, when the pressure in the fuel tank becomes a positive pressure exceeding the first pressure value with the fuel cap 10 shown in FIGS. 1 and 2 attached to the filler neck FN, the state shown in FIG. The positive pressure valve body 61 and the valve holding member 65 rise against the urging force of the spring 68, and the inside of the fuel tank passes through the cap internal passage and the like. 25d, it communicates with the outside air through the gap on the outer periphery of the positive pressure valve body 61, the through hole of the inner lid 30, and the like, so that the positive pressure state in the fuel tank is eliminated. When the differential pressure applied to the positive pressure valve body 61 is less than the biasing force of the first spring 68 due to communication with the outside air, the positive pressure valve body 61 is lowered by the biasing force of the first spring 68 as shown in FIG. Close the valve. Thus, the positive pressure valve body 61 opens and closes so that the pressure in the fuel tank does not exceed the first pressure value. At this time, the seat portion 63a where the annular recess 63b of the positive pressure valve body 61 is located contacts the first seating portion 20f. Since the seat portion 63a is disposed in a thin portion where the annular recess 63b is located, the seat portion 63a follows the pulse shape of the first seating portion 20f, and thus has high sealing performance.

  On the other hand, when the pressure in the fuel tank becomes lower than the second pressure value, the negative pressure valve body 71 moves downward against the urging force of the second spring 78 as shown in FIG. It leaves | separates from the 2nd seating part 63d of the positive pressure valve body 61. FIG. At this time, the positive pressure valve body 61 is seated on the first seating portion 20f, and a passage is formed between the negative pressure valve body 71 and the positive pressure valve body 61 in order to maintain this state. As a result, the fuel tank communicates with the atmosphere through the second valve flow path 63c, the first valve flow path 25d, and the communication hole 25c of the bottom portion 20d so that the negative pressure state in the fuel tank is eliminated. When the differential pressure applied to the negative pressure valve body 71 is less than the biasing force of the second spring 78, the negative pressure valve body 71 is closed.

(4) Actions / effects of the pressure regulating valve 50 In addition to the actions / effects described above, the following actions / effects are achieved by the configuration of the above embodiment.

(4) -1 The flow rate characteristic of the pressure regulating valve 50 can be improved by a simple configuration of the throttle portion formed by the annular protrusion 73 c provided in the negative pressure valve 70. FIG. 6 is a graph showing the flow characteristics of the pressure regulating valve 50. In FIG. 6, a range surrounded by a one-dot chain line is a range obtained from the flow characteristics of the positive pressure valve 60 and the negative pressure valve 70. A solid line indicates the present embodiment, and a broken line indicates the conventional example.

  It is preferable that the negative pressure valve 70 has such a characteristic that the flow rate Q falls within a range indicated by a one-dot chain line in which the flow rate Q rapidly increases in order to quickly suppress a change in the internal pressure of the fuel tank. When the negative pressure valve 70 is opened (FIG. 5), the differential pressure applied to the negative pressure valve body 71 is increased by the throttle portion formed by the annular protrusion 73c, and the valve opening force rapidly increases. Therefore, when the negative pressure is greater than or equal to the predetermined value, it is possible to obtain a characteristic that the flow rate Q rapidly increases within the range of the one-dot chain line.

  Further, when the positive pressure valve 60 is opened (FIG. 4), the negative pressure valve body 71 pushed by the second spring 78 moves upward together with the positive pressure valve body 61. At this time, the annular protrusion 73c moves upward with respect to the first seating portion 20f, and the flow path area of the first valve flow path 25d increases. Therefore, even when the positive pressure valve 60 is opened, the flow rate rapidly increases within the range indicated by the one-dot chain line, and excellent valve opening characteristics can be obtained as compared with the comparative example indicated by the broken line.

  The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

(1) FIG. 7 is a sectional view showing a pressure regulating valve 50B according to the second embodiment. The present embodiment is characterized in that the throttle portion is constituted by an annular protrusion 25Be that protrudes annularly from the inner wall of the valve chamber forming body 20Bb. That is, the valve chamber forming body 20Bb is divided into an upper valve chamber forming portion 20Bb-1 and a lower valve chamber forming portion 20Bb-2, and both forming portions are joined by ultrasonic welding or heat welding, An annular protrusion 25Be is provided to protrude from the lower part of the valve chamber forming part 20Bb-1. Since this annular protrusion 25Be increases the flow path area of the first valve flow path 25Bd as the negative pressure valve body 71B rises, the same effect as the embodiment of FIG.

(2) FIG. 8 is a sectional view showing a pressure regulating valve 50C according to the third embodiment. The present embodiment is characterized in that an annular protrusion 73Cc that constitutes the throttle portion protrudes from the outer periphery of the lower end of the negative pressure valve body 71C, and a guide rib 25Cf protrudes from the inner wall of the valve chamber forming body 20Cb. . The guide ribs 25Cf are protruded in the axial direction at six locations in the circumferential direction, and guide the vertical movement of the negative pressure valve body 71C to prevent center blurring. Also according to this embodiment, as the negative pressure valve body 71C rises, the flow area of the first valve flow path 25Cd that has been throttled by the annular protrusion 73Cc is increased, so the same effect as the embodiment of FIG. Play.

(3) In the above-described embodiment, the protrusion constituting the throttle portion is integrally provided on the negative pressure valve body and the valve chamber forming body. However, the present invention is not limited to this, and the inner wall of the negative pressure valve body and the valve chamber forming body of the cap body A configuration may be employed in which another member is attached to the.

It is sectional drawing which shows the fuel cap concerning 1st Example of this invention. It is sectional drawing to which the vicinity of the pressure regulation valve was expanded. It is sectional drawing which decomposed | disassembled the pressure regulation valve. It is explanatory drawing explaining the valve opening operation | movement at the time of the positive pressure of a pressure regulation valve. It is explanatory drawing explaining the valve opening operation | movement at the time of the negative pressure of a pressure regulation valve. It is a graph which shows the flow characteristic of a pressure regulation valve. It is sectional drawing which shows the pressure regulation valve concerning 2nd Example. It is sectional drawing which shows the pressure regulation valve concerning 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cap 20 ... Cap main body 20a ... Outer tube body 20b ... Valve chamber formation body 20d ... Bottom part 20f ... 1st seat part 20Bb ... Valve chamber formation body 20Bb- DESCRIPTION OF SYMBOLS 1 ... Upper valve chamber formation part 20Bb-2 ... Lower valve chamber formation part 20Cb ... Valve chamber formation body 21 ... Cap side engaging part 22 ... Flange part 24 ... Seal holding part 25 ... Valve chamber 25a ... Upper chamber 25b ... Lower chamber 25c ... Communication hole 25d ... First valve channel 25Bd ... First valve channel 25Be ... Annular projection ( Aperture part)
25Cd ... 1st valve flow path 25Cf ... Guide rib 30 ... Inner lid 30a ... Cylindrical support part 40 ... Lid 50 ... Pressure regulating valve 50B ... Pressure regulating valve 50C ... Pressure valve 60 ... Positive pressure valve 61 ... Positive pressure valve body 62 ... Positive pressure valve body 63a ... Seat portion 63b ... Annular recess 63c ... Second valve flow path 63d ... Second seat 63e ... annular groove 63f ... fitting part 63g ... side support recess 65 ... valve holding member 65a ... fitting hole 65b ... spring support part 68 ... first Spring 70 ... Negative pressure valve 71 ... Negative pressure valve body 71B ... Negative pressure valve body 71C ... Negative pressure valve body 72 ... Negative pressure valve body 72a ... Upper wall plate part 72b ... Side wall part 73a ... seat part 73c ... annular protrusion (throttle part)
73Cc ... annular protrusion (throttle part)
78 ... Second spring 80 ... Torque mechanism FN ... Filler neck FNb ... Inlet (tank opening)
GS ... Gasket

Claims (2)

A cap main body (20) attached to the tank opening of the fuel tank, and a cap internal passage housed in the cap main body (20) and formed in the cap main body (20) are opened and closed to open the inside of the fuel tank. In a fuel cap provided with a pressure regulating valve (50) for regulating pressure,
The pressure regulating valve (50) includes a positive pressure valve (60) that opens when the pressure in the fuel tank becomes higher than the first pressure value, and the pressure in the fuel tank becomes lower than the second pressure value. A negative pressure valve (70) that sometimes opens,
The positive pressure valve (60) includes a positive pressure valve body (61) that opens and closes a first valve flow path (25d) that constitutes a part of the flow path in the cap, and is fixed at one end to the cap body side, and A first spring (68) for applying a biasing force in the closing direction to the positive pressure valve body (61),
The positive pressure valve body (61)
A positive pressure valve body (62);
The first valve channel (25d) is formed on the positive pressure valve body (62), faces the first valve channel (25d) and is seated on a first seat portion (20f) provided on the cap body. ) Closing sheet portion (63a),
A second valve flow path (63c) formed through the positive pressure valve body (62) and constituting a part of the flow path in the cap;
A second seat portion (63d) formed on the positive pressure valve body (62) and facing the second valve flow path (63c),
The negative pressure valve (70) includes a negative pressure valve body (71) that opens and closes the second valve flow path (63c), and is fixed to the cap main body at the other end and is opposed to the negative pressure valve body (71). A second spring (78) for applying a biasing force in the closing direction;
The negative pressure valve body (71)
A cup-shaped negative pressure valve main body (72) formed from an upper wall plate portion (72a) and a cylindrical side wall portion (72b) protruding from the outer peripheral portion of the upper wall plate portion (72a);
A seat portion (73a) formed on the upper wall plate portion (72a) and seated on the second seating portion (63d) to close the second valve flow path (63c);
The positive pressure valve is provided at a location facing the first valve flow path (25d), and the flow path area of the first valve flow path (25d) is narrowed when the negative pressure valve body (71) is closed. A throttle that increases the flow area of the first valve flow path (25d) in a state where the negative pressure valve body (71) is moved integrally with the positive pressure valve body (61) as the body (61) is opened. And
A fuel cap characterized by comprising:   2. The fuel according to claim 1, wherein the throttle portion is an annular protrusion (73 c) protruding so as to narrow the flow path of the first valve flow path (25 d) from the upper part of the side wall portion (72 b). cap.

Images