Vapor separator tank

Abstract

To provide a vapor separator tank capable of holding a pressure regulator with a simple structure and suppressing increase in the number of components, assembling man-hours, and manufacturing cost.SOLUTION: The VST (vapor separate tank) 10 includes a casing 20 that has a lower case 22 and an upper case 24 joined to each other and in which a fuel storage chamber 26 for storing liquid fuel is formed, a pump 40 that is disposed in the casing 20 and pumps the liquid fuel stored in the fuel storage chamber 26, and a regulator (pressure regulator) 50 that is sandwiched between the lower case 22 and the upper case 24 in an accommodation space formed in the casing 20 and adjusts the discharge pressure of the pump 40 to be constant. The casing 20 includes the regulator support 70, which contacts and supports the regulator 50.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a vapor separator tank. [Background technology]

[0002] Conventionally, there has been known a technique relating to a vapor separator tank equipped with a pressure regulator. For example, Patent Document 1 describes a vapor separator tank that houses a pressure regulator sandwiched between a lower case that forms a fuel storage chamber and an upper case that closes an upper opening of the lower case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-73630 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the structure described in Patent Document 1, the pressure regulator is supported by a holder (housing) and an O-ring disposed between the lower case and the pressure regulator. Using such a holder and a fixture for attaching the holder to the casing increases the number of parts and assembly steps. It may also become necessary to prepare dedicated fixing parts, which could increase manufacturing costs.

[0005] The present invention was made in consideration of these problems, and its purpose is to provide a vapor separator tank that supports a pressure regulator with a simpler configuration and can suppress increases in the number of parts, assembly labor, and manufacturing costs. [Means for solving the problem]

[0006] In order to achieve the above object, the vapor separator tank of the present invention is a vapor separator tank that separates gas from liquid fuel supplied to an internal combustion engine, and is equipped with a casing having a lower case and an upper case joined together and having a fuel storage chamber formed therein for storing liquid fuel, a pump that pressurizes the liquid fuel stored in the fuel storage chamber, and a pressure regulator that is sandwiched between the lower case and the upper case within an accommodation space that communicates with the fuel storage chamber and adjusts the pump's discharge pressure to a constant level, and the casing has a regulator support portion that abuts against and supports the pressure regulator.

[0007] The pressure regulator may have a flange portion that protrudes radially outward from its outer peripheral surface, and the regulator support portion may be formed in the lower case, cover the outer peripheral surface of the lower part of the pressure regulator from the radially outward side, and have a convex portion that abuts the flange portion from below.

[0008] The regulator support portion may be formed on the upper case at a position facing the protrusion in the vertical direction, and may have a recess that sandwiches the flange between the protrusion and the regulator support portion.

[0009] The regulator support portion has a bottom surface portion that blocks the lower side of the pressure regulator on the inner side of the convex portion, and the convex portion may have a notch formed therein that connects the space on the inner side of the convex portion with the space on the outer side thereof to allow the liquid fuel to flow into the fuel storage chamber.

[0010] The regulator support portion may have an inner peripheral side of the protrusion and a portion located below the pressure regulator that is open so as to communicate with the fuel storage chamber.

[0011] A portion of the lower case that faces the lower surface of the pressure regulator may extend obliquely downward from the pressure regulator side toward the center of the fuel storage chamber. [Effects of the Invention]

[0012] In the vapor separator tank of the present invention, the casing directly supports the pressure regulator, eliminating the need for specialized fixing parts for supporting the pressure regulator to the casing and fixtures for attaching the fixing parts to the casing. Therefore, the vapor separator tank of the present invention supports the pressure regulator with a simpler configuration, making it possible to suppress increases in the number of parts, assembly man-hours, and manufacturing costs. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a side view schematically showing an outboard motor equipped with a vapor separator tank according to an embodiment. [Figure 2] FIG. 2 is a plan view schematically showing the outboard motor. [Figure 3] FIG. 2 is a side view showing the vapor separator tank. [Figure 4] FIG. 2 is a plan view showing the vapor separator tank. [Figure 5] FIG. 5 is a cross-sectional view taken along line AA in FIG. [Figure 6] FIG. 4 is an enlarged cross-sectional view showing the vicinity of a regulator support portion. [Figure 7] FIG. 10 is a perspective view showing the vicinity of the regulator support portion from which the regulator has been removed. [Figure 8] FIG. 2 is a perspective view showing the vicinity of a regulator support portion to which a regulator is attached. [Figure 9] FIG. 10 is an enlarged cross-sectional view showing another example of the configuration of the regulator support portion. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0015] FIG. 1 is a side view schematically showing an outboard motor equipped with a vapor separator tank according to an embodiment. FIG. 2 is a plan view schematically showing the outboard motor. Below, each component will be described based on the longitudinal, lateral, and vertical directions of a boat (not shown) on which the outboard motor 1 is mounted. The outboard motor 1 is mounted on a boat and rotates a propeller 4 using power from a multi-cylinder engine (internal combustion engine) 3 mounted in a main body case 2. As shown in FIG. 2, within the main body case 2, an intake manifold 5 for drawing air into the engine 3 includes multiple intake pipes 5a arranged to extend longitudinally from a mixing body 5b at intervals from the side of the engine 3. Note that the multiple intake pipes 5a are not shown in FIG. 1.

[0016] The outboard motor 1 is equipped with a vapor separator tank 10 (hereinafter referred to as "VST 10") that temporarily stores liquid fuel to be supplied to the engine 3 and has a gas-liquid separation function that separates gases such as evaporated gas and air bubbles from the liquid fuel. The VST 10 is connected between the engine 3 and a fuel tank (not shown) that stores liquid fuel, and liquid fuel is supplied from the fuel tank by a low-pressure pump (not shown). In this embodiment, the VST 10 is disposed in the space between the side surface of the engine 3 and the intake manifold 5, but it may also be disposed in front of the engine 3, for example.

[0017] The specific configuration of the VST 10 will be described below with reference to Fig. 3 to Fig. 5. Fig. 3 is a side view showing the VST 10, Fig. 4 is a plan view showing the VST 10, and Fig. 5 is a cross-sectional view taken along line AA in Fig. 4. As shown in Fig. 5, the VST 10 includes a casing 20, a float mechanism 30, a pump 40, and a pressure regulator 50 (hereinafter referred to as "regulator 50").

[0018] The casing 20 has a lower case 22 and an upper case 24. The lower case 22 forms a fuel storage chamber 26 that stores liquid fuel. The fuel storage chamber 26 is a space surrounded by a first bottom surface portion 221B of the lower case 22 and a first side wall portion 221W that extends upward from the first bottom surface portion 221B. A drain port 22a is formed in the bottom of the lower case 22 for discharging fuel during maintenance or when the internal combustion engine will not be used for an extended period of time during the off-season.

[0019] The upper case 24 is a lid-like member that closes the upper opening of the lower case 22, and is joined to the lower case 22 with fasteners. The upper case 24 is provided with a fuel inlet 24a through which liquid fuel flows in from the fuel tank, and a fuel outlet 24b through which liquid fuel supplied to the engine 3 flows out. The fuel outlet 24b is connected to a discharge flow path 24c to which a pump 40, which will be described later, is connected. The upper case 24 also has two air vents 24d that discharge gases, such as evaporated fuel and air bubbles, from the liquid fuel to the outside.

[0020] The float mechanism 30 has a float 32, a hinge 34, and a float valve 36. The float 32 is supported by the upper case 24 via the hinge 34 so as to be able to swing freely, and is floated on the liquid fuel in the fuel storage chamber 26. The float 32 moves in accordance with the up and down movement of the liquid fuel level LS, which is illustrated by the dashed line in Fig. 5. The hinge 34 is structured to move up and down simultaneously with the float valve 36, which is provided in a flow path communicating with the fuel inlet portion 24a.

[0021] As a result, when the amount of liquid fuel in the fuel storage chamber 26 is less than a predetermined reference value, the float 32 is positioned below a predetermined position, causing the hinge 34 to push down the valve element of the float valve 36, thereby opening the float valve 36. As a result, liquid fuel flows into the fuel storage chamber 26 from the fuel inlet 24a. On the other hand, when the amount of liquid fuel in the fuel storage chamber 26 is equal to or greater than the reference value, the float 32 attempts to position above the predetermined position, causing the hinge 34 to push up the valve element of the float valve 36, thereby closing the float valve 36. As a result, the flow of liquid fuel from the fuel inlet 24a into the fuel storage chamber 26 is restricted. Therefore, the amount of liquid fuel in the fuel storage chamber 26 is regulated to a constant level.

[0022] The pump 40 is a high-pressure pump that is mounted inside the casing 20 and pressure-feeds the liquid fuel stored in the fuel storage chamber 26. A first filter 61 that filters the liquid fuel in the fuel storage chamber 26 is connected to an intake port of the pump 40. Meanwhile, a discharge port of the pump 40 is connected to a discharge flow path 24c formed in the upper case 24, and the liquid fuel discharged from the pump 40 is guided through the discharge flow path 24c to a fuel outflow portion 24b and then pressure-feeds to the engine 3. A second filter 62 that filters the liquid fuel is disposed midway through the discharge flow path 24c.

[0023] The regulator 50 is disposed in an accommodation space 28 defined by the lower case 22 and the upper case 24 and communicating with the fuel storage chamber 26. The accommodation space 28 is connected to a relief passage 24e that communicates with a midpoint of the discharge passage 24c. The regulator 50 is configured to include a valve body, a valve seat, a spring, and other components (not shown) within a substantially cylindrical case, and opens in response to an increase in the pressure of the fuel flowing into the relief passage 24e, allowing excess fuel to return to the fuel storage chamber 26. This allows the discharge pressure of the pump 40, i.e., the pressure of the liquid fuel supplied to the engine 3, to be adjusted to a constant value.

[0024] Next, the support structure of regulator 50 will be described. Fig. 6 is an enlarged cross-sectional view showing the vicinity of the regulator support portion, Fig. 7 is a perspective view showing the vicinity of the regulator support portion with regulator 50 removed, and Fig. 8 is a perspective view showing the vicinity of the regulator support portion with regulator 50 attached. In this embodiment, the case of regulator 50 includes upper case 52U and lower case 52D, as shown in Fig. 6. A flange 54 having a disk shape that protrudes from the outer circumferential surface toward the outside in the radial direction of regulator 50 is formed at the connection between upper case 52U and lower case 52D.

[0025] The regulator 50 configured as described above is disposed in the accommodation space 28. The portion of the accommodation space 28 defined by the lower case 22 is a space surrounded by a second bottom surface portion (bottom surface portion) 222B located above the first bottom surface portion 221B and a second side wall portion 222W extending upward from the second bottom surface portion 222B, and is in communication with the fuel storage chamber 26. As shown in FIG. 7, the second bottom surface portion 222B is formed to extend rearward in the front-to-rear direction from a part of the first side wall portion 221W. The second bottom surface portion 222B faces a lower surface 53 of the regulator 50, from which the liquid fuel flows out, and extends horizontally in proximity to the lower surface 53 to close the lower side of the regulator 50. The second side wall portion 222W is formed to be continuous with the first side wall portion 221W, which extends at the same height.

[0026] The regulator 50 is supported by a regulator support portion 70 formed by the lower case 22 and the upper case 24 within the accommodation space 28. The regulator support portion 70 has a second bottom surface portion 222B, an annular protrusion (protrusion) 72 formed on the second bottom surface portion 222B, and an annular recess (recess) 74 formed on the upper case 24.

[0027] The annular protrusion 72 is provided with a gap between it and the second side wall 222W and protrudes upward from the second bottom surface 222B in an annular shape. The annular protrusion 72 has a diameter larger than that of the lower case 52D of the regulator 50 but smaller than that of the flange 54. As shown in FIG. 8 , the annular protrusion 72 covers the outer peripheral surface of the lower case 52D of the regulator 50 from the radially outer side and abuts against the flange 54 from below. In other words, the regulator 50 is supported by the annular protrusion 72 at the flange 54 with the lower case 52D housed inside the annular protrusion 72. Therefore, the annular protrusion 72 has a height such that at least the lower case 52D does not interfere with the second bottom surface 222B when abutting against the flange 54. Note that a portion of the annular protrusion 72 may not abut against the flange 54.

[0028] As shown in Figure 6, the annular recess 74 is an annular depression formed in the upper case 24 at a position facing the annular protrusion 72 in the up-down direction. The annular recess 74 is formed with a diameter slightly larger than that of the flange 54. The regulator 50 is positioned by accommodating the flange 54 in the space surrounded by the annular protrusion 72 and the annular recess 74, and when the lower case 22 and the upper case 24 are joined, the flange 54 is sandwiched between the annular protrusion 72 and the annular recess 74 from above and below. This fixes the regulator 50 within the accommodation space 28.

[0029] Furthermore, the annular protrusion 72 is formed with a plurality of notches 72S extending in the up-down direction from the second bottom surface portion 222B. The plurality of notches 72S are formed at intervals from one another in the circumferential direction of the annular protrusion 72. As a result, the liquid fuel flowing out of the regulator 50 is returned to the fuel storage chamber 26 through the notches 72S and the gap between the annular protrusion 72 and the second side wall portion 222W, as indicated by the white arrows in FIG. 8. In this way, the plurality of notches 72S communicate between the space on the inner circumferential side and the space on the outer circumferential side of the annular protrusion 72, allowing the liquid fuel to flow.

[0030] As described above, the VST (vapor separator tank) 10 according to the embodiment includes a casing 20 having a lower case 22 and an upper case 24 joined together and having a fuel storage chamber 26 formed therein for storing liquid fuel, a pump 40 disposed within the casing 20 for pumping out the liquid fuel stored in the fuel storage chamber 26, and a regulator (pressure regulator) 50 sandwiched between the lower case 22 and the upper case 24 within an accommodation space formed in the casing 20 for adjusting the discharge pressure of the pump 40 to a constant level. The casing 20 has a regulator support portion 70 that abuts against and supports the regulator 50.

[0031] With this configuration, casing 20 directly supports regulator 50, eliminating the need for dedicated fixing parts for supporting regulator 50 relative to casing 20 and fixtures for attaching the fixing parts to casing 20. Therefore, with VST 10 according to the embodiment, regulator 50 can be supported with a simpler configuration, and increases in the number of parts, assembly man-hours, and manufacturing costs can be suppressed.

[0032] Furthermore, regulator 50 has flange 54 that protrudes radially outward from the outer circumferential surface, and regulator support portion 70 has an annular protrusion (protrusion) 72 that covers the outer circumferential surface of lower case (lower portion) 52D of regulator 50 from the radially outer side and abuts flange 54 from below. With this configuration, regulator 50 can be easily supported simply by placing flange 54 on annular protrusion 72.

[0033] Furthermore, regulator support portion 70 is formed in upper case 24 at a position vertically facing annular protrusion 72, and has an annular recess (recess) 74 that sandwiches flange 54 between annular protrusion 72. With this configuration, flange 54 is sandwiched between annular protrusion 72 and annular recess 74, enabling regulator 50 to be supported more stably.

[0034] The regulator support portion 70 also has a second bottom surface portion (bottom surface portion) 222B that is located on the inner circumferential side of the annular protrusion 72 and blocks the lower side of the regulator 50. The annular protrusion 72 has a notch 72S formed therein that allows liquid fuel to flow into the fuel storage chamber 26. With this configuration, the second bottom surface portion 222B temporarily receives the liquid fuel from the regulator 50 and then allows it to return to the fuel storage chamber 26 via the notch 72S. As a result, the generation of bubbles can be suppressed compared to when the liquid fuel directly flows from the regulator 50 into the fuel storage chamber 26. The second bottom surface portion 222B is preferably located close to the lower surface 53 of the regulator 50 to achieve a defoaming effect. The second bottom surface portion 222B is more preferably located below the liquid level LS that is aimed to be maintained by the float mechanism 30. It is even more preferable that the lower surface 53 of the regulator 50 be located below the liquid level LS.

[0035] Furthermore, by adjusting the shape and size of notch 72S, such as the width, height, and opening position, it is possible to further improve the defoaming effect of the liquid fuel, thereby eliminating the need to separately attach a defoaming cover to regulator 50 and reducing the number of parts and assembly steps. In addition, by adjusting the shape and size of notch 72S, such as the width, height, and opening position, it is possible to adjust the flow direction of the liquid fuel, for example, by preventing the liquid fuel containing air bubbles released from regulator 50 from heading toward the intake port of pump 40. Note that notch 72S is not limited to a shape extending in the vertical direction and may have other shapes, such as a lattice shape or a shape with multiple round holes.

[0036] 9 is an enlarged cross-sectional view showing another example of the configuration of the regulator support portion. As shown in the figure, second bottom surface portion 222B does not have to completely cover the area below regulator 50. That is, second bottom surface portion 222B may include a portion extending outward from annular protrusion 72 so as to form annular protrusion 72, and the portion on the inner periphery of annular protrusion 72 may be open so as to communicate with fuel storage chamber 26. In the example shown in FIG. 9, the portion facing bottom surface 53 of regulator 50 is formed as part of first side wall portion 221W constituting fuel storage chamber 26. As shown in the figure, this first side wall portion 221W extends obliquely downward from regulator 50 toward the center of fuel storage chamber 26, that is, toward the front side in the front-to-rear direction.

[0037] With this configuration, the liquid fuel from the regulator 50 can be returned to the fuel storage chamber 26 without forming multiple notches 72S in the annular protrusion 72. Furthermore, by adjusting the angle of the first side wall 221W, the liquid fuel from the regulator 50 can be smoothly guided into the fuel storage chamber 26 along the first side wall 221W in a desired direction. For example, the first side wall 221W may be shaped to extend obliquely downward from the second bottom surface 222B and then extend vertically downward from its midpoint. This more effectively prevents the liquid fuel containing the air bubbles traveling along the first side wall 221W from heading toward the intake port of the pump 40. Furthermore, the first side wall 221W may be shaped to extend obliquely downward from the second bottom surface 222B at a first predetermined angle and then extend from its midpoint at a second predetermined angle that is gentler than the first predetermined angle. Furthermore, first side wall portion 221W may have a recessed portion at its midpoint that bulges outward from lower case 22. This can slow the flow of liquid fuel running down first side wall portion 221W and more effectively prevent the liquid fuel containing the air bubbles from heading toward the intake port of pump 40. Also, first side wall portion 221W may be provided with a fin-shaped portion or the like for adjusting the flow direction of the liquid fuel.

[0038] Although the description of the embodiment is now complete, aspects of the present invention are not limited to this embodiment. For example, the annular protrusion 72 and the annular recess 74 do not have to be annular as long as they can sandwich the flange 54 between them and do not interfere with other parts of the regulator 50. Furthermore, the regulator support portion 70 may be formed in a shape different from that of the embodiment as long as it is structured to abut against and support the regulator 50. In this case, it is preferable that the regulator support portion 70 has a shape that takes into consideration the adjustment of the flow direction of the liquid fuel from the regulator 50 and the defoaming effect, as described above. [Explanation of symbols]

[0039] 1 outboard motor 3. Engine (internal combustion engine) 10 Vapor Separator Tank (VST) 20 Casing 22 Lower case 222B 2nd bottom part (bottom part) 24 Upper Case 26 Fuel storage chamber 28 Containment Space 30 Float mechanism 40 Pump 50 Pressure regulator (regulator) 54 Tsuba 70 Regulator support 72 Annular convex part (convex part) 72S notch 74 Annular recess (recess)

Claims

1. A vapor separator tank that separates gas from liquid fuel supplied to an internal combustion engine, a casing having a lower case and an upper case joined to each other, the casing having a fuel storage chamber formed therein for storing the liquid fuel; a pump that pumps the liquid fuel stored in the fuel storage chamber; a pressure regulator sandwiched between the lower case and the upper case in an accommodation space communicating with the fuel storage chamber, the pressure regulator adjusting the discharge pressure of the pump to a constant level; Equipped with The casing is a vapor separator tank having a regulator support portion that abuts against and supports the pressure regulator.

2. The pressure regulator has a flange portion that protrudes radially outward from an outer circumferential surface, the regulator support portion is formed on the lower case, covers the outer peripheral surface of the lower portion of the pressure regulator from the radially outer side, and has a protrusion that abuts against the flange portion from below. The vapor separator tank according to claim 1 .

3. The vapor separator tank according to claim 2 , wherein the regulator support portion has a recess formed on the upper case at a position vertically facing the protrusion, and the recess sandwiches the flange between the regulator support portion and the protrusion.

4. the regulator support portion has a bottom surface portion that closes a lower side of the pressure regulator on an inner peripheral side of the protrusion, The protrusion has a notch formed therein, the notch communicating an inner space with an outer space of the protrusion, and allowing the liquid fuel to flow into the fuel storage chamber. The vapor separator tank according to claim 2 or 3.

5. 4. The vapor separator tank according to claim 2, wherein the regulator support portion has an inner peripheral side of the protrusion, and a portion thereof located below the pressure regulator is open so as to communicate with the fuel storage chamber.

6. 6. The vapor separator tank according to claim 5, wherein a portion of the lower case facing the lower surface of the pressure regulator extends obliquely downward from the pressure regulator side toward the center of the fuel storage chamber.

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