JP2004316536A - Fuel feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently discharge generated vapor and cool a fuel in a fuel feeding device including a plunger pump. <P>SOLUTION: The fuel feeding device includes a plunger 112, a tube 111 housing the plunger 112 reciprocatably and demarcating a pump chamber P, an intake valve 123 allowing suction of the fuel, and a discharge valve 127 allowing discharge of the fuel. A fuel reservoir 150 including a filter 152 is provided integrally upstream of the intake valve 123 in relation to the plunger pump 110 sucking and discharging the fuel, and a discharge passage 170a communicating the outlet 121a of the tube 111 and the fuel reservoir 150 is provided, thereby discharging leaking fuel or generated vapor towards the fuel reservoir 150. Thus, the vapor can be discharged efficiently, and the fuel in the fuel reservoir can be cooled by the vapor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel supply device provided with an electromagnetically driven plunger pump, and more particularly to a fuel supply device applied to supply fuel to an engine or a heater for a vehicle.
[0002]
[Prior art]
As a conventional fuel supply device for supplying a fuel to a combustor such as a heater, as shown in FIG. 5, fuel in a fuel tank 1 is guided to a filter unit 3 by a feed pipe 2 and filtered fuel is electromagnetically driven. A plunger pump 4 sucks and feeds the compressed air and supplies it to a combustor 5.
As shown in FIG. 5, the plunger pump 4 includes a plunger 4b reciprocating in a cylinder 4a, an exciting coil 4c, a yoke 4d, a coil spring (not shown) for urging the plunger 4a, and the like. The check valve is opened and closed by the pressure difference between the front and rear spaces to suck and discharge fuel (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-11-218076
[Problems to be solved by the invention]
By the way, in the plunger pump 4 as described above, the fuel that leaks from the outer periphery of the plunger 4b toward the upstream side (rearward) during the pressure feeding is rapidly reduced in pressure, and is generated by the heat generated from the coil 4c when energized. The fuel is heated by frictional heat generated by sliding of the plunger 4b, and vapor is continuously generated.
These generated vapors are returned to the fuel tank 1 through the feed pipe 2 and, because of their continuous generation, are sucked into the pump chamber and discharged together with the fuel. As a result, particularly when the ambient temperature and the fuel temperature are high, a desired discharge amount or discharge pressure cannot be obtained, and the fuel cannot be supplied stably.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to efficiently discharge generated vapor, and to perform fuel cooling by using the generated vapor. In particular, it is an object of the present invention to provide a fuel supply device capable of improving pump discharge performance at high temperatures.
[0006]
[Means for Solving the Problems]
A fuel supply device according to the present invention includes a filter for filtering fuel guided from a fuel tank, a plunger that reciprocates in a predetermined direction by electromagnetic force, a cylinder body that reciprocates the plunger and that defines a pump chamber, and a pump chamber. And a plunger pump that includes a discharge valve that permits discharge of fuel from the pump chamber, and a plunger pump that sucks and discharges fuel. A fuel reservoir for temporarily storing fuel is provided integrally on the upstream side of the suction valve, and between the cylindrical body and the fuel reservoir, fuel leaking from the outer periphery of the plunger or generated vapor is stored in the fuel reservoir. And a discharge passage for discharging the liquid toward the portion.
[0007]
According to this configuration, the fuel filtered by the filter is temporarily stored in the fuel storage section, is drawn into the pump chamber from the suction valve by the reciprocating motion of the plunger, and is discharged from the discharge valve. At this time, the fuel leaked from the outer periphery of the plunger to the space on the other end side of the plunger or the generated vapor is discharged to the fuel reservoir through the discharge passage. Thus, the vapor can be prevented from being discharged together with the fuel, and the fuel in the fuel reservoir can be cooled by the vapor, so that the pump discharge performance particularly at high temperatures can be improved.
In addition, since the fuel reservoir is provided integrally with the plunger pump, the fuel cooled by the vapor can be quickly guided to the pump chamber while minimizing the influence of the external atmosphere.
[0008]
In the above configuration, the cylindrical body is formed to face one end of the plunger and opened and closed by the suction valve, and a discharge port formed to face the other end of the plunger and communicates with the discharge passage. And a discharge port formed on the inner wall surface of the pump chamber and opened and closed by a discharge valve.
According to this configuration, the fuel reservoir, the suction port (suction valve), the plunger, and the discharge port are configured to be arranged substantially linearly, so that the components are integrated and the device is downsized. be able to.
[0009]
In the above configuration, it is possible to adopt a configuration in which the filter is disposed in the fuel reservoir, and the fuel reservoir has an opening that connects the discharge passage upstream of the filter.
According to this configuration, it is not necessary to provide a separate case for accommodating the filter (for example, a case forming a single filter unit) and a pipe for connecting the case and the plunger pump. it can. Further, the fuel and vapor leaked from the cylinder flow into the fuel reservoir through an opening provided on the upstream side of the filter, and the fuel is filtered again by the filter and is sucked in. While cooling, is discharged toward the fuel tank by its buoyancy.
[0010]
In the above configuration, a configuration may be employed in which the opening is provided with a dispersing unit for dispersing the vapor flowing through the discharge passage.
According to this configuration, the vapor that has flowed through the discharge passage is dispersed (miniaturized) by the dispersing means, so that the surface area in contact with the fuel is increased, and the cooling effect of the fuel is enhanced. Emission efficiency of all vapors can be increased.
[0011]
In the above configuration, a configuration can be adopted in which the dispersing unit includes a mesh filter.
According to this configuration, the vapor that has flowed through the discharge passage is dispersed (miniaturized) by the mesh filter, and when not operating, foreign matter such as dust mixed in the fuel tank is discharged from the opening through the discharge passage. It can be prevented from flowing into the inside.
[0012]
In the above configuration, it is possible to adopt a configuration in which the plunger pump is integrally provided with a fuel pressure regulator for adjusting the pressure of the discharged fuel.
According to this configuration, when this device is used together with an injection nozzle (injector) of an engine or the like, it is possible to perform fuel pressure inlet control before injection. Further, since the fuel pressure regulator is provided integrally with the plunger pump, the device can be miniaturized and simplified by modularizing the plunger pump, the fuel pressure regulator and the like, and the device can be easily installed in-line.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 4 show one embodiment of a fuel supply device according to the present invention. FIG. 1 is a system diagram when the device is applied to an engine, FIG. 2 is a cross-sectional view showing the structure of the device, FIG. 3 is a sectional view showing a part of the device, and FIG. 4 is a schematic diagram for explaining the operation of the device.
[0014]
As shown in FIG. 1, this system includes a fuel tank 10, an injector 20 for injecting fuel into an engine E disposed below the fuel tank 10, and a feed pipe 30 connecting between the fuel tank 10 and the injector 20. , 30 ′, a fuel supply device 100 disposed in the middle of the feed pipes 30, 30 ′, a control circuit 200 for controlling the system, and the like.
[0015]
As shown in FIGS. 1 and 2, the fuel supply device 100 includes a plunger pump 110 for sucking and discharging fuel, a fuel reservoir 150 for temporarily storing fuel, and directing leaked fuel and vapor to the fuel reservoir 150. And a fuel pressure regulator 180 of an inlet control type for controlling the pressure of fuel.
As described above, since the device 100 is modularized so as to integrally include the plunger pump 110, the fuel reservoir 150, the discharge pipe 170, and the fuel pressure regulator 180, the size and the structure can be simplified as a whole. In-line installation can be easily performed.
[0016]
The plunger pump 110 is a positive displacement pump driven by electromagnetic force. As shown in FIGS. 1 and 2, the plunger pump 110 slides in the cylinder 111 forming a part of the cylinder and reciprocates linearly. A cylindrical plunger 112 disposed, yokes 113 and 114 fitted on the outer periphery of the cylinder 111 to form a magnetic path, an exciting coil 116 wound around a bobbin 115 disposed around the yokes 113 and 114, A case 117 formed of a resin material or the like to cover the outer periphery of the coil 116, a bracket 118 and a hook plate 119 attached around the case 117 to form a magnetic path, and a wave disposed between the bobbin 115 and the bracket 118. A washer 120 and the like are provided.
[0017]
As shown in FIG. 2, an end wall 113a is formed at an end of the yoke 113 defining an end of the cylindrical body, and a fitting hole 113a 'is formed in the end wall 113a. And a connector pipe 121 defining an outlet 121a. A return spring 122 is arranged between the end wall 113a and the plunger 112.
[0018]
As shown in FIG. 2, a passage member 123 that defines a suction port 123 a and forms a part of a cylinder is fitted to an end of the yoke 114. The passage member 123 has a holding member 125 that holds a suction valve 124 that opens and closes a suction port 123a and that allows the flow of fuel. The holding member 125 holds the suction valve 124 in a state where the suction valve 124 is urged in a closing direction by a spring 124a. A return spring 122 is disposed between the holding member 125 and the plunger 112.
A pump chamber P for sucking and discharging fuel is defined between the suction valve 124 and the plunger 112.
[0019]
That is, the cylindrical body (cylinder 111, yoke 113, passage member 123) has a suction port 123a opened and closed by a suction valve 124 at a position facing one end of the plunger 112, and a position facing the other end of the plunger 112. A discharge port 121a communicating with a discharge passage 170a described later and a discharge port 126a opened and closed by a discharge valve 127 on the inner wall surface of the pump chamber P are formed respectively.
As described above, the fuel reservoir 150, the suction port 123a (the suction valve 124), the plunger 112, and the discharge port 121a are formed so as to be arranged substantially linearly in the reciprocating direction of the plunger 112. It is possible to achieve centralization of parts and downsizing of the device.
[0020]
As shown in FIG. 2, a discharge passage 126 extending in a direction perpendicular to the reciprocating direction of the plunger 112 and defining a discharge port 126 a is formed on the inner wall surface of the passage member 123. In the discharge passage 126, a holding member 128 that holds a discharge valve 127 that opens and closes the discharge port 126a and allows fuel flow is disposed. The holding member 128 attaches the discharge valve 127 in a closing direction by a spring 127a. It is held in a vigorous state.
[0021]
As shown in FIG. 2, the fuel reservoir 150 is provided at an upstream position adjacent to the suction valve 124, in a case 151 having an opening 151 a fitted to the passage member 123 and communicating with the suction port 123 a, and inside the case 151. A mesh-shaped filter 152 disposed and covering the opening 151a and having a vapor discharge valve 152a, a connector pipe 151b provided at the upper end of the case 151 and connecting the feed pipe 30, and an opening 151c 'provided on an upper side wall of the case 151 are provided. A mesh-like filter 155 or the like as dispersing means is provided above the defining connector pipe 151c and the filter 152 so as to cover the opening 151c '.
[0022]
Then, as shown in FIG. 2, a discharge pipe 170 is connected to the connector pipe 120 and the connector pipe 151c. The discharge pipe 170 defines a discharge passage 170a that discharges fuel leaked from the outer periphery of the plunger 112 or generated vapor toward the fuel reservoir 150 (case 151).
[0023]
Therefore, the fuel leaked from the outer periphery of the plunger 112 and the generated vapor flow into the case 151 from the opening 151c ′ located on the upstream side of the filter 152 through the discharge passage 170a from the discharge port 121a. Then, the fuel is filtered again by the filter 152 and is sucked into the pump chamber P. On the other hand, the generated vapor is discharged to the fuel tank 10 through the feed pipe 30 by its own buoyancy while cooling the fuel by its vaporization.
[0024]
Here, since the mesh-shaped filter 155 for dispersing the vapor is disposed in the opening 151c ', the vapor flowing through the discharge passage 170a, as shown in FIGS. , And the filter 155 disperses (miniaturizes). Therefore, the surface area in contact with the fuel is increased, the cooling effect of the fuel is enhanced, and the efficiency of discharging the vapor toward the fuel tank 10 is also enhanced. Further, when not operating, foreign matter such as dust mixed in the fuel tank 10 can be prevented from flowing into the discharge passage 170a from the opening 151c '.
[0025]
Here, since the filter 152 is disposed in the fuel reservoir 150 (case 151), a separate case and the case and the plunger pump are compared with a case where a single filter unit 3 is employed as in the related art. No piping or the like for connecting to 110 is required, and the apparatus can be simplified accordingly.
[0026]
As shown in FIG. 2, on the downstream side of the discharge valve 127, the regulator 180 includes an adjusting valve 182 that opens and closes the passage 181; a spring 182a that urges the adjusting valve 182 in a closing direction; and a connector pipe that connects the feed pipe 30 '. 183 is formed by a diaphragm 184, a spring 184a, and the like, which are operated by a pressure difference between the pressure in the passage 183 defined by the outside air and the outside air pressure.
[0027]
That is, when the pressure in the passage 183a falls below a predetermined level, the diaphragm 184 contacts the needle 182 'of the adjustment valve 182, and opens the adjustment valve 182 against the urging force of the spring 182a. Thereby, the fuel on the upstream side flows out to the passage 183 a through the passage 181 and is supplied to the injection nozzle 20.
Then, when the pressure of the fuel in the passage 183a becomes equal to or higher than a predetermined level, the diaphragm 184 is operated by the pressure, and the regulating valve 182 is closed.
[0028]
As described above, since the fuel pressure regulator 180 is provided integrally with the plunger pump 110 and is modularized, when the device 100 is used together with the injector 20 of the engine E, the fuel pressure inlet control can be performed. Needless to say, the apparatus 100 can be downsized and simplified, and the in-line installation can be easily performed.
[0029]
As shown in FIG. 1, the control circuit 200 performs various arithmetic processes and issues a control signal, a control circuit 201 that drives the plunger pump 110, and a state of the engine E (for example, engine speed, water temperature, A sensor 203 for detecting intake air temperature, intake pressure, etc.), a detection circuit 204 for detecting an output signal of the sensor 203, a storage unit 205 storing various control maps and the like are formed.
[0030]
Next, the operation of this device will be described. First, when the plunger 112 moves rightward in FIG. 2 due to the electromagnetic force generated by energization of the coil 116, the plunger 112 sucks against the urging force of the spring 124a due to the pressure difference. The valve 124 opens, and the fuel in the fuel reservoir 150 filtered by the filter 152 is sucked from the suction port 123a and flows into the pump chamber P.
[0031]
When the power supply to the coil 116 is cut off, the plunger 112 stops and the suction valve 124 closes, and at the same time, the plunger 112 moves in the reverse direction (to the left in FIG. 2) by the urging force of the return spring 122. Then, the fuel in the pump chamber P is compressed. When the fuel is compressed beyond a predetermined pressure, the discharge valve 127 opens against the urging force of the spring 127a, and the compressed fuel is discharged from the discharge port 126a. Thereafter, when the urging force of the return spring 122 is balanced, the plunger 112 stops.
[0032]
The fuel that has flowed into the fuel pressure regulator 180 from the discharge port 126a is supplied to the injector 20 while being adjusted in pressure, and is injected at a predetermined timing toward the engine E.
The above operation has been described with reference to the basic operation when the plunger 112 reciprocates once. However, in the normal operation, the plunger 112 is reciprocated continuously, so that the predetermined operation according to the moving stroke is performed. A volume of fuel is continuously suctioned and pumped.
[0033]
By the way, in the continuous suction and discharge operation of the plunger 112, the fuel leaked from the outer periphery of the plunger 112 and the generated vapor are introduced into the fuel reservoir 150 (case 151) from the discharge port 121a through the discharge passage 170a. I will At this time, the vapor is dispersed (refined) by the filter 155 and is discharged to the fuel tank 10 through the feed pipe 30 while efficiently cooling the fuel. On the other hand, the fuel is cooled by being mixed with the fuel in the fuel reservoir 150, filtered again by the filter 152, and drawn into the pump chamber P from the suction port 123a.
The vapor generated in the filter 152 opens the vapor discharge valve 152 a by its buoyancy, flows out of the filter 152, and is discharged to the fuel tank 10 through the feed pipe 30.
[0034]
In the above-described embodiment, the configuration in which the filter 152 for filtering the fuel is disposed in the fuel reservoir 150 has been described. However, the present invention is not limited to this, and a separate filter unit is provided as in the related art. And the fuel reservoir 150 are integrally formed, and also in a configuration in which the discharge passage 170a that communicates the discharge port 151c 'with the fuel reservoir 150 is provided. Further, the fuel can be cooled by the vapor.
[0035]
In the above embodiment, the configuration in which the fuel pressure regulator 180 is provided integrally with the plunger pump 110 has been described. However, the present invention is not limited to this, and even if the fuel pressure regulator 180 is formed separately, The generated vapor can be efficiently discharged, and the fuel can be cooled by the vapor.
[0036]
In the above embodiment, the mesh filter 155 is used as the dispersing means for dispersing the vapor. However, the present invention is not limited to this, and the case 151 may be integrally formed with a lattice structure, Other configurations can be employed as long as the vapor mass can be dispersed (miniaturized).
[0037]
【The invention's effect】
As described above, according to the fuel supply device of the present invention, the plunger pump is provided integrally with the fuel storage portion for temporarily storing fuel on the upstream side of the suction valve, and the cylinder and the fuel storage portion In between, there is provided a discharge passage for discharging fuel leaked from the outer periphery of the plunger or generated vapor toward the fuel reservoir, so that fuel leaked from the outer periphery of the plunger or generated vapor passes through the discharge passage. The fuel is discharged to the fuel reservoir. Thereby, the vapor can be prevented from being discharged together with the fuel, and the fuel in the fuel reservoir can be cooled by the vapor, so that the pump discharge performance particularly at high temperatures can be improved.
Further, since the fuel reservoir is provided integrally with the plunger pump, the fuel cooled by the vapor can be quickly guided to the pump chamber while minimizing the influence of the external atmosphere.
[Brief description of the drawings]
FIG. 1 is a system diagram in which a fuel supply device according to the present invention is employed in a fuel supply system of an engine.
FIG. 2 is a cross-sectional view showing one embodiment of a fuel supply device.
FIG. 3 is a sectional view showing a part of the fuel supply device.
FIGS. 4A and 4B are schematic diagrams for explaining the operation of the fuel supply device.
FIG. 5 is a system diagram showing a conventional fuel supply device.
[Explanation of symbols]
E engine 10 fuel tank 20 injector 30, 30 'feed pipe 100 fuel supply device 110 plunger pump 111 cylinder (cylinder)
112 Plunger 113 Yoke (tubular body)
114 Yoke 116 Coil 121 Connector pipe 121a Discharge port 122 Return spring 123 Passage member (tubular body)
123a suction port 124 suction valve 124a spring 125 holding member 126 discharge passage 126a discharge port 127 discharge valve 127a spring 128 holding member 150 fuel reservoir 151 case 151a openings 151b, 151c connector pipe 151c 'opening 152 filter 152a vapor discharge valve 155 Filter (dispersion means)
170 discharge pipe 170a discharge passage 180 fuel pressure regulator 181 passage 182 regulating valve 182a spring 183 connector pipe 183a passage 184 diaphragm 184a spring 200 control circuit 201 control unit 202 drive circuit 203 sensor 204 detection circuit 205 storage unit

Claims (6)

A filter that filters the fuel guided from the fuel tank, a plunger that reciprocates in a predetermined direction by electromagnetic force, a cylinder that reciprocates the plunger and that defines a pump chamber, and that sucks fuel into the pump chamber. A fuel supply device comprising: a permissible suction valve, a discharge valve that permits discharge of fuel from the pump chamber, and a plunger pump that suctions and discharges fuel.
The plunger pump is provided integrally with a fuel storage portion for temporarily storing fuel on the upstream side of the suction valve,
A fuel supply device is provided between the cylinder and the fuel reservoir, and a discharge passage for discharging fuel leaking from the outer periphery of the plunger or generated vapor toward the fuel reservoir is provided. . The cylindrical body is formed to face one end of the plunger and opened and closed by the suction valve, and a discharge port formed to face the other end of the plunger and communicates with the discharge passage. A discharge port formed on the inner wall surface of the pump chamber and opened and closed by the discharge valve,
The fuel supply device according to claim 1, wherein: The filter is disposed in the fuel reservoir,
The fuel reservoir, on the upstream side of the filter, has an opening communicating with the discharge passage,
The fuel supply device according to claim 1 or 2, wherein: Dispersing means for dispersing the vapor flowing through the discharge passage is provided in the opening,
The fuel supply device according to claim 3, wherein: The dispersing means comprises a mesh filter.
The fuel supply device according to claim 4, wherein: The plunger pump is provided integrally with a fuel pressure regulator that adjusts the pressure of the discharged fuel.
The fuel supply device according to any one of claims 1 to 5, wherein:

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