JP2014231763A - Fuel supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel supply device capable of suppressing power consumption when heating a fuel.SOLUTION: An upstream passage 21 extending to a filter body 42 of a fuel filter device 1 includes a heating unit 70. The heating unit includes: first and second heat generators 81 and 82; and first and second temperature switches 91 and 92 that respectively turn on/off energization to the first and second heat generators 81 and 82. The first temperature switch 91 and the second temperature switch 92 have different temperatures at which an on/off state is switched. It is configured to increase the number of the temperature switches to be brought into the on-state as the temperature of a fuel is decreased.

Description

  The present invention relates to a fuel supply device capable of heating fuel before being filtered by a filter body.

  Conventionally, there is a fuel supply device including a fuel filter device provided with a heating element that generates heat when energized in a fuel flow passage leading to a filter body. When the temperature of the fuel is low, the heating element is energized to heat the fuel, and the wax component in the fuel is prevented from being deposited to prevent the filter body from being clogged (see, for example, Patent Document 1 below).

JP 59-190462 A

  However, in the above-described prior art fuel supply device, when the fuel temperature is equal to or lower than the predetermined temperature, the heating element is energized regardless of the fuel temperature to heat the fuel with a constant output and melt the wax component in the fuel. It is supposed to be. Therefore, even when the fuel temperature is equal to or lower than the predetermined temperature, there is a problem that the fuel is heated more than necessary and power is excessively consumed.

  This invention is made | formed in view of the said point, and it aims at providing the fuel supply apparatus which can suppress the power consumption at the time of heating a fuel.

In order to achieve the above object, in the present invention,
A filter body (42) for filtering the fuel supplied from the fuel tank (2) to the supply destination (3, 4, 5);
A plurality of heating elements (81, 82) provided in a fuel flow path (21) from the fuel tank to the filter body, and generating heat when energized to heat the supplied fuel;
A plurality of switch devices (91, 92) that are provided corresponding to the plurality of heating elements and turn on / off the power to each of the plurality of heating elements,
The plurality of switch devices are for switching the on / off state according to the fuel temperature of the supplied fuel that circulates upstream of the arrangement site of the plurality of heating elements in the fuel flow path,
As the fuel temperature is lower, the number of switch devices that are turned on among the plurality of switch devices is increased.

  According to this, when heating the supplied fuel before being filtered by the filter with the heating element, the number of heating elements to be energized can be increased as the temperature of the supplied fuel is lower. Therefore, when the amount of heat necessary for melting the wax component in the fuel is relatively small, the number of heat generating elements that generate heat can be suppressed. In this way, power consumption when heating the supplied fuel before being filtered can be suppressed.

  In addition, the code | symbol in the parenthesis attached | subjected to each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

1 is a schematic configuration diagram of a common rail fuel injection system that is a fuel supply device according to a first embodiment to which the present invention is applied. It is sectional drawing which shows the structure of the fuel filter apparatus used for a fuel supply apparatus. It is sectional drawing which expands and illustrates the structure of a part of fuel filter apparatus. It is a top view which shows the structure of an upper plate and a 1st, 2nd heat generating body. It is a top view which shows the structure of an inside plate. It is a top view which shows the structure of a lower plate. It is a circuit diagram which shows the circuit structure of a heating unit. It is sectional drawing which shows the structure of a temperature switch, and has shown the non-energized state (off state). It is sectional drawing which shows the structure of a temperature switch, and has shown the electricity supply state (ON state). It is a graph which shows an example of the relationship of the power consumption of the heating unit with respect to fuel temperature.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those described previously. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination is not particularly troublesome.

(First embodiment)
A first embodiment to which the present invention is applied will be described with reference to FIGS.

  As shown in FIG. 1, the fuel supply device of the present embodiment is a common rail fuel injection system mounted on a vehicle, for example. The fuel supply device includes a fuel tank 2, a supply pump 3, a common rail 4, an injector 5, and a fuel filter device 1 interposed between the fuel tank 2 and the supply pump 3.

  The supply pump 3 is configured by a feed pump (low pressure feed pump), a solenoid valve as a flow rate control device, a high pressure pump, and the like, although a specific configuration is not shown. As the feed pump, for example, a trochoid pump or a vane pump can be used. For example, a plunger pump can be used as the high-pressure pump.

  When the supply pump 3 is operated, the normal pressure fuel stored in the fuel tank 2 is sucked, flows through the fuel pipe 6 and is supplied into the common rail 4. At that time, water is separated from the fuel in the fuel filter device 1, and foreign matters in the fuel are captured.

  The common rail 4 holds the fuel pressurized by the high-pressure pump of the supply pump 3 in an accumulated state. An injector 5 that injects fuel into each cylinder of the engine is connected to the common rail 4 according to the number of cylinders. The fuel held in the pressure accumulation state in the common rail 4 is injected from the injector 5. A return pipe 7 is connected to the common rail 4. The surplus fuel in the common rail 4 is returned to the fuel tank 2 via the return pipe 7.

  Low-pressure fuel that flows into the control pressure chamber of each injector 5 and is discharged from the injector 5 low-pressure port such as fuel and leak fuel used for injector operation, and low-pressure fuel such as leak fuel from the supply pump 3 also recirculate. It joins the pipe 7 and returns to the fuel tank 2.

  Further, the common rail fuel injection system of the present embodiment is connected to an ECU (not shown) as a control means. This ECU optimally controls the flow rate of the fuel discharged from the supply pump 3 based on the input fuel pressure inside the common rail 4, the engine speed Ne, the accelerator opening α, and the like. Further, the ECU controls the opening / closing timing of the solenoid valve of the injector 5 connected to the common rail 4. Thus, the fuel injection timing and the fuel injection amount into each cylinder of the engine are controlled.

  As shown in FIG. 2, the fuel filter device 1 includes a housing 10, a filter member 40, a lower cap 60, a heating unit 70, and the like. A fuel passage 20 including a housing chamber for the filter member 40 is formed inside the housing 10.

  The housing 10 includes a case 11 and a cap 12. The case 11 is a cup-shaped body (bottomed cylindrical body) made of, for example, a metal thin plate material that constitutes the outer shell. The cap 12 is made of resin, for example, and has a cup shape shallower than the case 11. The cap 12 is attached to the upper opening end of the case 11.

  Specifically, a screwing member 17 that is, for example, a metal annular body is joined to the inside of the upper end opening edge of the case 11. On the inner peripheral surface of the screwing member 17, a female screw portion that is screwed with a male screw portion formed on the outer peripheral surface of the cap 12 is formed. The annular screwing member 17 is joined to the case 11 over the entire circumference, for example, by laser welding.

  Between the cap 12 and the screwing member 17, an O-ring 18 as a seal member is interposed below each screw forming portion. When the cap 12 is screwed into the screwing member 17, the O-ring 18 is compressed between the cap 12 and the screwing member 17 to form a liquid tight seal structure.

  The fuel filter device 1 is mounted on a vehicle, for example, with the lower side in the figure as the direction of gravity so that the axial direction of the case 11 substantially coincides with the vertical direction. The case 11 is provided with a support portion 15 formed as a step portion slightly above the central portion in the axial direction. An opening is formed in the bottom 16 of the case 11, and a lower cap 60 is attached so as to close the opening.

  The cap 12 has an inlet 13 at the edge of the ceiling. A pipe extending from the fuel tank 2 is connected to the introduction port 13 and the fuel in the fuel tank 2 flows. The cap 12 has an outlet 14 at the center of the ceiling. A pipe that extends to the supply pump 3 is connected to the outlet 14, and fuel flows out toward the supply pump 3.

  The member in which the inlet 13 is formed and the member in which the outlet 14 is formed are formed as separate members from the cap 12, for example, are welded and integrated with the cap 12. The cap 12 has a cylindrical portion 122 that protrudes downward from the center of the ceiling portion. The introduction port 13 communicates with the outer space of the cylindrical portion 122. On the other hand, the outlet 14 communicates with the inner space of the cylindrical portion 122. As shown in FIG. 3, in addition to the cylindrical portion 122, a boss portion 121, a pin 123, and a rib 124 protrude downward from the lower surface of the ceiling portion of the cap 12.

  As shown in FIG. 2, the filter member 40 is disposed in the housing 10 at a relatively upper portion inside the cylindrical portion of the case 11. In the housing 10, an upper space 10a is formed above the filter member 40, and a lower space 10c larger than the upper space 10a is formed below the filter member 40.

  The upper space 10 a is a fuel introduction space above the filter member 40 and outside the cylindrical portion 122. The lower space 10 c forms a water reservoir chamber (reservoir, storage space) for storing water separated from the supplied fuel that passes through the housing 10. A side space 10b that connects the upper space 10a and the lower space 10c is formed on the outer peripheral side of the filter member 40, that is, between the filter member 40 and the cylindrical portion of the case 11.

  The filter member 40 includes a filter body 42 and a support body 41 that supports the filter body 42. The support 41 is made of resin, for example, and has an upper end plate 43, an outer cylinder 44, a center cylinder 45, and a lower end plate 46. The outer cylinder 44 projects downward from the outer peripheral edge of the upper end plate 43. On the other hand, the central cylinder 45 protrudes upward from the peripheral edge of the central opening of the upper end plate 43. The upper end plate 43, the outer cylinder 44, and the center cylinder 45 are integrally formed, for example.

  The lower end of the outer cylinder 44 is locked to the support portion 15 of the case 11, and the filter member 40 is disposed at a predetermined position in the housing 10. The outer cylinder 44 is formed with missing portions at a plurality of locations in the circumferential direction, and the upper space 10a and the side space 10b communicate with each other through the missing portions. The central cylinder 45 is disposed on the outer peripheral side of the cylindrical portion 122 of the cap 12 with an O-ring serving as a seal member interposed therebetween.

  As the filter body 42 that is a dust collection filter, for example, a chrysanthemum filter formed by bending a porous sheet body made of a pulp material or a nonwoven fabric can be used. Further, by forming a water-repellent layer on the surface of the porous sheet body forming the filter body 42, not only can the solid body be collected by the filter body 42, but also water droplets contained in the fuel pass through the filter body 42. Can be suppressed. The upper end and the lower end of the filter body 42 are joined to the support body 41 by adhesion, for example.

  A fuel passage 20 for supplying fuel from the inlet 13 to the outlet 14 is formed in the housing 10. The upper space 10a and the side space 10b constitute an upstream passage 21 on the fuel flow upstream side of the filter body 42 in the fuel passage 20. The upstream passage 21 is a part of the fuel flow passage from the fuel tank 2 to the filter body 42.

  The lower cap 60 includes, for example, a resin main body 61 and a water level sensor 63 partly integrated with the main body 61. The body portion 61 closes the opening of the bottom portion 16 of the case 11 with an O-ring 62 as a seal member interposed between the body portion 61 and the case 11.

  The water level sensor 63 for detecting the water level in the lower space 10 c is a float type sensor, and includes a shaft member 64, a switch unit 65, a float 66, and a stopper 67. The main body portion 61 has a hollow shaft member 64 that protrudes upward, and a switch portion 65 is disposed in the hollow portion of the shaft member 64.

  The float 66 is a hollow member made of resin, for example, having a through hole at the center. The float 66 has a shaft member 64 disposed in the through hole, and can move up and down along the shaft member 64. In the float 66, a ring-shaped magnet is disposed at a relatively lower position facing the through hole. The float 66 moves according to the water level of the lower space 10c, and when the float 66 reaches a position where the float 66 comes into contact with the stopper 67, the magnet brings the contact pair of the switch portion 65 into contact. Based on a signal output with the operation of the switch unit 65, for example, warning means provided in the vehicle driver's seat is operated.

  The base end (lower part) of the stopper 67 in which the displacement restricting portion of the float 66 is formed at the tip is formed in an annular shape, and is formed on the outer peripheral surface of the main body 61 on the inner peripheral surface of the base end. A female screw portion that is screwed into the male screw portion 61a is formed. When the main body 61 is screwed into the stopper 67, the main body 61 is fixed to the case 11, and the O-ring 62 is compressed between the main body 61 and the case 11 to form a liquid tight seal structure.

  The male screw portion 61a of the main body portion 61 is not formed on the entire circumference in the circumferential direction, and is provided with a non-formed portion. When the screwed state of the main body 61 and the stopper 67 is loosened, the sealing function by the O-ring 62 is lowered, and the water stored in the lower space 10c is removed from the housing 10 through the male screw portion non-forming portion of the main body 61. A drain path for discharging to the outside is formed.

  The heating unit 70 is disposed in the upper space 10 a in the housing 10. As shown in FIG. 3, the heating unit 70 includes an upper plate 71, an intermediate plate 72, a lower plate 73, a first heating element 81, a second heating element 82, a first temperature switch 91, a second temperature switch 92, and the like. ing. The second heating element 82 and the second temperature switch 92 are not shown in FIG. 3 because they are in front of the page.

  The upper plate 71, the middle plate 72, and the lower plate 73 are all formed of, for example, a metal thin plate material. As shown in FIG. 4, the upper plate 71 has a shape larger than a semicircle, in which a part of the disk is linearly missing. That is, the outer shape of the upper plate 71 is formed by an arc larger than a semicircle and a string (line segment) connecting both ends of the arc.

  A cylindrical insertion hole 715 for inserting the central cylinder 45 of the filter member 40 is formed in the upper plate 71 at the center of the outer peripheral arc. The upper plate 71 is formed with a plurality of positioning holes 711 into which a plurality of bosses 121 protruding from the ceiling of the cap 12 are inserted. The positioning hole 711 positions the upper plate 71 in the radial direction and the circumferential direction of the cap 12. The upper plate 71 has a plurality of pin insertion holes 713 into which a plurality of pins 123 protruding from the ceiling of the cap 12 are inserted. The first and second heating elements 81 and 82 arranged on the lower surface side of the upper plate 71 are positioned by the pins 123 inserted in the pin insertion holes 713 and projecting downward from the lower surface of the upper plate 71.

  The upper plate 71 has a terminal portion 714 that protrudes from the center of the straight side portion (string portion) on the right side of the drawing toward the right side of the drawing. Further, the upper plate 71 is formed with a semicircular cutout portion 712 that is recessed from the straight side portion on the right side to the left side in the drawing at the upper and lower portions of the projecting portion of the terminal portion 714. Yes.

  As shown in FIG. 5, the middle plate 72 has a shape obtained by dividing a semicircular plate having substantially the same outer shape as the upper plate 71 into upper and lower parts along a straight line extending in the left and right directions. Accordingly, the middle plate 72 includes an upper plate member 72a and a lower plate member 72b. A slit that prevents mutual conduction is formed between the plate member 72a and the plate member 72b.

  The middle plate 72 is formed with a pair of semicircular cutout cylindrical portions 725 into which the central cylinder 45 is inserted at the center of the outer peripheral arc. The middle plate 72 is formed with a plurality of positioning holes 721 into which a plurality of bosses 121 protruding from the ceiling of the cap 12 are inserted. The positioning hole 721 positions the middle plate 72 in the radial direction and the circumferential direction of the cap 12. Further, the middle plate 72 is formed with a semicircular cutout portion 722 that is recessed from the respective arc-shaped side portions of the plate members 72a and 72b toward the center.

  The middle plate 72 has a lead 723 extending from a straight side portion on the right side of the drawing. The lead 723 extends from each of the pair of plate members 72 a and 72 b and is connected to the common terminal portion 724. The lead 723 connecting the plate member 72a and the terminal portion 724 is provided with a first temperature switch 91, and this energization path can be opened and closed. On the other hand, a second temperature switch 92 is interposed in the lead 723 connecting the plate member 72b and the terminal portion 724, and this energization path can be opened and closed.

  As shown in FIG. 6, the lower plate 73 has a shape obtained by dividing a semicircular plate having substantially the same outer shape as that of the upper plate 71 into upper and lower parts along a straight line extending in the left and right directions as shown in the figure. Accordingly, the lower plate 73 includes an upper plate member 73a and a lower plate member 73b. A slit for preventing mutual conduction is formed between the plate member 73a and the plate member 73b.

  The lower plate 73 is formed with a pair of semicircular cutout portions 735 into which the central cylinder 45 is inserted at the center of the outer peripheral arc. The lower plate 73 is formed with a plurality of positioning holes 731 for inserting a plurality of boss portions 121 protruding from the ceiling portion of the cap 12. The positioning hole 731 positions the lower plate 73 in the radial direction and the circumferential direction of the cap 12.

  Further, the lower plate 73 is provided with an urging portion 732 cut and raised toward the front side of the drawing (the upper side in FIGS. 2 and 3). When the three plates 71, 72, 73 are stacked, the urging unit 732 is located below the first heat generating body 81 and the second heat generating body 82 and urges the middle plate 72 upward.

  As shown in FIG. 3, the three plates 71, 72, and 73 are stacked in order of the upper plate 71, the middle plate 72, and the lower plate 73 from the upper side to the lower side. Between the upper plate 71 and the middle plate 72, a first heating element 81 and a second heating element 82 are interposed.

  Specifically, the first heating element 81 is disposed between the upper plate 71 and the plate member 72a, and the second heating element 82 is disposed between the upper plate 71 and the plate member 72b. The first heating element 81 and the second heating element 82 are both constituted by two heating elements 80 in this example.

  Each of the heating elements 80 has a disk shape, for example, and is an element that generates heat when energized. The heating element 80 has, for example, a positive resistance temperature coefficient, and has a characteristic that the resistance value rapidly increases at a specific temperature. The heating element 80 is made of, for example, a ceramic mainly composed of barium titanate. Ni-Ag dual structure electrodes are provided on both surfaces of the heat generating element 80 (surfaces in pressure contact with the upper plate 71 and the middle plate 72). In this example, the heat generating element 80 is mainly used below the specific temperature.

  A central cylinder 45 is disposed in the cylindrical insertion hole 715 and the cylindrical placement portions 725 and 735 of each plate 71, 72, 73, and a plurality of boss portions 121 are inserted in the plurality of positioning holes 711, 721, 731. It is installed. And the screw | thread 74 as a locking member is screwed in each front-end | tip of the some boss | hub part 121, and the head part of the screw | thread 74 is supporting the lower plate 73 from the downward direction.

  With the above-described stacked configuration, the urging portion 732 of the lower plate 73 urges the middle plate 72 upward. Accordingly, the first heating element 81 and the second heating element 82 are in pressure contact with the upper plate 71 and the middle plate 72. Specifically, the urging portion 732 of the plate member 73a urges the plate member 72a upward. Accordingly, the first heating element 81 is in pressure contact with the upper plate 71 and the plate member 72a. Further, the urging portion 732 of the plate member 73b urges the plate member 72b upward. Accordingly, the second heating element 82 is in pressure contact with the upper plate 71 and the plate member 72b.

  When the three plates 71, 72, 73 are stacked and arranged, the center points AA, the corners BB, and the corners CC shown in FIGS. It arrange | positions so that it may correspond seeing from the axial direction of the housing 10. FIG.

  The ribs 124 provided on the cap 12 extend in the direction of the front and back of the drawing in FIGS. The rib 124 hangs down from the ceiling of the cap 12 so that the lower end (the lower end in the drawing) is along the straight side portion (string portion, see FIG. 4) of the upper plate 71.

  The cap 12 is provided with a pair of external connection terminals 19 for supplying power to the heating unit 70 from the outside of the fuel filter device 1. The terminal portion 714 of the upper plate 71 is connected to one of the pair of external connection terminals 19 via a lead member. Further, the terminal portion 724 of the middle plate 72 is connected to the other of the pair of external connection terminals 19 via a lead member. With the configuration described above, when the external connection terminal 19 is electrically connected to, for example, an in-vehicle storage battery, an electric circuit shown in FIG. 7 is formed. In FIG. 7, for example, a main switch for supplying power from the storage battery is omitted only when the ignition switch of the vehicle is on.

  As shown in FIG. 8, the first temperature switch 91 includes a case 901, a cap 902, a guide member 903, a bimetal plate 904, a rod 905, a first contact piece 906, and a second contact piece 907. The case 901 is made of resin, for example, and is formed in a bottomed cylindrical shape. The cap 902 is formed by molding a thin metal plate, for example, and is attached to the case 901 so as to close the opening on the right side of the case 901 in the figure. The guide member 903 is made of, for example, resin, and is disposed at a predetermined position inside the cylindrical portion of the case 901.

  The bimetal plate 904 is formed by, for example, stacking and integrating dissimilar metal layers, and has a disk shape. The bimetal plate 904 is disposed between the cap 902 and the guide member 903 inside the case 901. The bimetal plate 904 is gently supported at the periphery of the case 901 and the cap 902, and changes its curved state according to the temperature. The bimetal plate 904 is a deformable member that deforms according to temperature.

  The rod 905 is, for example, a metal columnar member, and is disposed coaxially with the cylindrical portion of the case 901. The illustrated right end portion of the rod 905 is in contact with the central portion of the bimetal plate 904. The rod 905 is disposed in a guide hole that penetrates the center of the guide member 903. When the bimetal plate 904 is deformed, the rod 905 is displaced in the axial direction (the left-right direction in the drawing) in conjunction with the deformation.

  Each of the first contact piece 906 and the second contact piece 907 is formed by, for example, forming a thin plate-shaped metal band member, and is disposed so as to penetrate the bottom portion of the case 901 at a position facing each other across the center. Has been. Leads 723 are connected to portions of the first contact piece 906 and the second contact piece 907 disposed outside the case 901.

  As for the 1st contact piece 906 and the 2nd contact piece 907, the bending part located in the case 901 is supported by the guide member 903. FIG. The first contact piece 906 and the second contact piece 907 have a distal end side portion extending inward in the radial direction from the bent portion, and are arranged so that the distal end portions overlap each other when viewed from the axial direction of the case 901. ing.

  The first contact piece 906 is in contact with the left end of the rod 905 in the vicinity of the tip (specifically, the portion that does not overlap the second contact piece 907 when viewed from the axial direction). Accordingly, as shown in FIG. 8, when the bimetal plate 904 is curved so that the central portion swells to the left in the drawing, the bimetal plate 904 is near the tip of the first contact piece 906 via the rod 905. To the left in the figure. Along with this, the distal end portion of the first contact piece 906 is elastically deformed and bent, and the first contact piece 906 and the second contact piece 907 are separated from each other.

  On the other hand, as shown in FIG. 9, when the bimetal plate 904 has a reduced amount of swelling of the central portion to the left in the drawing or is bent so as to bulge the central portion to the right in the drawing, the rod 905. The pressing of the first contact piece 906 to the vicinity of the tip end portion via the is stopped. Along with this, the bending of the portion on the tip side from the bent portion of the first contact piece 906 is eliminated, and the first contact piece 906 and the second contact piece 907 come into contact with each other.

  For example, when the temperature of the fuel flowing outside the case 901 becomes less than 5 ° C., the first temperature switch 91 shifts from the off state shown in FIG. 8 to the on state shown in FIG. Further, for example, when the temperature of the fuel becomes 10 ° C. or higher, the fuel cell is set to shift from the on state shown in FIG. 9 to the off state shown in FIG.

  The second temperature switch 92 has the same configuration as the first temperature switch 91. However, the temperature characteristics of the deformation of the bimetal plate 904 are different from those of the first temperature switch 91. For example, when the temperature of the fuel flowing outside the case 901 becomes less than −7.5 ° C., the second temperature switch 92 shifts from the off state shown in FIG. 8 to the on state shown in FIG. Further, for example, when the temperature of the fuel becomes −2.5 ° C. or more, it is set so as to shift from the on state shown in FIG. 9 to the off state shown in FIG.

  That is, the first temperature switch 91 and the second temperature switch 92 are switch devices that switch on and off according to the fuel temperature. The first temperature switch 91 and the second temperature switch 92 are switched on and off at different temperatures.

  The first contact piece 906 and the second contact piece 907 correspond to the contact pair in the present embodiment, and the first temperature switch 91 and the second temperature switch 92 change the contact pair in accordance with the deformation of the bimetal plate 904 that is a deformable member. It corresponds to a temperature-sensitive switch device that opens and closes.

  In the fuel filter device 1 configured as described above, when the supply pump 3 shown in FIG. 1 is driven, the supplied fuel is introduced from the introduction port 13 into the upper space 10 a in the housing 10. The introduced fuel first flows above the upper plate 71 of the heating unit 70 from the left to the right in FIG. 3, changes the flow direction to the rib 124, and flows into the notch 712 of the upper plate 71. To do. The fuel that has passed through the notch 712 flows between the upper plate 71 and the middle plate 72 from the right in the figure to the left in the figure, and the flow direction is changed to the side wall of the cap 12 so that the cut in the middle plate 72 is cut. It flows into the slit between the notch 722 and the plate members 72a and 72b.

  The fuel flowing between the upper plate 71 and the middle plate 72 passes around either the first heating element 81 or the second heating element 82. At that time, when one or both of the first heating element 81 and the second heating element 82 are energized to generate heat, the fuel passing therearound is heated.

  The fuel that has passed through the slit between the notch 722 and the plate members 72 a and 72 b flows between the middle plate 72 and the lower plate 73, and then is supplied above the upper end plate 43 of the filter member 40. The fuel that has passed through the heating unit 70 and has been supplied to the upper side of the filter member 40 is guided from the upper space 10a to the side space 10b, and then passes through the filter body 42 in the radially inward direction. When passing through the filter body 42, foreign substances in the fuel are captured and removed.

  In the side space 10b, water in the fuel aggregates to form water droplets, and the water droplets settle by gravity and are stored in the lower space 10c from the bottom 16 side of the case 11. Since the water repellent layer is formed on the surface of the filter body 42, fine water droplets are also repelled by the water repellent layer and hardly pass through the filter body 42, and are separated from the fuel and stored in the lower space 10c. On the other hand, the fuel that has passed through the filter body 42 rises in the inner space of the filter body 42, flows from the center cylinder 45 into the cylindrical portion 122, and is led out of the housing 10 through the outlet 14.

  As described above, when the supplied fuel passes through the housing 10, in the upper space 10a, the fuel immediately after passing through the notch 712 of the upper plate 71 around the first temperature switch 91 and the second temperature switch 92. Is mainly distributed. Therefore, the first temperature switch 91 and the second temperature switch 92 are switched on and off according to the temperature of the supplied fuel before flowing around the first and second heating elements 81 and 82.

  For example, when the ignition switch of the vehicle is turned on and the supply pump 3 is activated, the on / off state of the first temperature switch 91 and the second temperature switch 92 is already in accordance with the fuel temperature of the fuel supplied in the upper space 10a. Is set.

  For example, when the fuel temperature is lower than the first predetermined temperature (5 ° C. in this example) and equal to or higher than the second predetermined temperature (−7.5 ° C. in this example), such as when the outside air temperature is low, the first temperature switch 91 Is turned on, and the second temperature switch 92 is turned off. Along with this, the first heating element 81 is energized, and the first heating element 81 generates heat and heats the fuel flowing around it. At this time, the second heating element 82 is not energized, and the second heating element 82 does not generate heat. That is, the heating unit 70 heats the fuel only with the first heating element 81.

  Further, when the fuel temperature is lower than the second predetermined temperature (in this example, −7.5 ° C.) at the time of further low outside air temperature or the like, both the first temperature switch 91 and the second temperature switch 92 are turned on. It has become. Accordingly, the first heating element 81 and the second heating element 82 are energized, and both the heating elements 81 and 82 generate heat and heat the fuel flowing around. That is, the heating unit 70 heats the fuel with both the first heating element 81 and the second heating element 82.

  When the supply pump 3 continues to drive and the relatively high-temperature recirculated fuel recirculates into the fuel tank 2, the temperature of the supplied fuel gradually rises. When the fuel temperature of the fuel supplied from the fuel tank 2 to the upper space 10a rises and the fuel temperature rises above a third predetermined temperature (−2.5 ° C. in this example) higher than the second predetermined temperature, The second temperature switch 92 is switched from the on state to the off state, and energization of the second heating element 82 is stopped.

  Further, when the fuel temperature of the fuel supplied from the fuel tank 2 to the upper space 10a further rises and the fuel temperature rises to a fourth predetermined temperature (10 ° C. in this example) higher than the first predetermined temperature, In addition to the second temperature switch 92, the first temperature switch 91 is switched from the on state to the off state, and the energization of not only the second heating element 82 but also the first heating element 81 is stopped.

  According to the fuel supply device including the fuel filter device 1 having the above-described configuration, the first heating element 81 and the second heating element 82 of the heating unit 70 are provided in the upstream passage 21 leading to the filter body 42. The heating unit 70 is provided corresponding to the first heating element 81 and the second heating element 82, and the first temperature switch 91 for turning on / off the current to the first heating element 81 and the second heating element 82, and A second temperature switch 92 is provided.

  The first temperature switch 91 and the second temperature switch 92 are in an on / off state according to the fuel temperature of the supplied fuel that circulates in the upstream portion of the upstream passage 91 from the portion where the first heating element 81 and the second heating element 82 are disposed. Is to switch. The first temperature switch 91 and the second temperature switch 92 have different switching temperatures in the on / off state, and the temperature switches that are in the on state increase as the fuel temperature decreases.

  According to this, when the supplied fuel before being filtered by the filter body 42 is heated by the first and second heating elements 81 and 82, the number of heating elements to be energized is increased as the temperature of the supplied fuel is lower. be able to. Therefore, when the amount of heat necessary for melting the wax component in the fuel is relatively small, the number of heat generating elements that generate heat can be suppressed. In this way, it is possible to reliably prevent clogging of the filter body 42 with wax while suppressing power consumption when heating the supplied fuel before being filtered by the filter body 42.

  FIG. 10 shows an example of outputs from both the heating elements 81 and 82, that is, an example of power consumption of the heating unit 70, by a solid line. In this example, a heating element 80 having an output of 90 W for each heating element is used in the temperature range shown in the graph. Moreover, the comparative example using the heating unit which turns on and off both the heat generating bodies 81 and 82 with one temperature switch is shown by a broken line.

  If the temperature at which the wax component can be melted is 5 ° C. or higher so as not to clog the filter body 42, the amount of heat required for heating the fuel increases as the fuel temperature decreases, as shown by the two-dot chain line, for the fuel below 5 ° C. To do. On the other hand, in the present embodiment, the output can be increased as the fuel temperature is lower, in a range exceeding the amount of heat necessary for fuel heating. That is, energy saving can be achieved by the difference from the comparative example. Specifically, in the example shown in FIG. 10, when the fuel temperature is lower than 5 ° C. and −7.5 ° C. or higher, the power consumption of 180 W can be reduced.

  Each of the first temperature switch 91 and the second temperature switch 92 includes a bimetal plate 904 that is deformed according to the temperature of the supplied fuel, and the first and second contact pairs are formed by the deformation of the bimetal plate 904. This is a temperature-sensitive switch device that opens and closes the contact pieces 906 and 907.

  According to this, the plurality of temperature-sensitive switch devices that open and close the contact pairs with the bimetal plate 904 that senses and deforms the temperature of the supplied fuel, and the energization ON / OFF state to the plurality of heating elements according to the fuel temperature of the supplied fuel Can be switched. Therefore, there is no need to provide a temperature sensor or a control device that controls the operation of the switch by the output signal of the temperature sensor. Thereby, the structure which suppresses the power consumption at the time of heating supply fuel can be simplified.

  Moreover, each temperature switch 91 and 92 differs in the open temperature and closing temperature of a contact pair. That is, the temperature switches 91 and 92 have different transition temperatures from the off-state to the on-state and the transition temperatures from the off-state to the on-state, so that the temperature characteristics of the on / off state switching have hysteresis. According to this, chattering of the contact pair can be prevented.

  The first heating element 81 and the second heating element 82 are disposed inside the housing 10 that houses the filter body 42 therein. According to this, the supply fuel before being filtered by the filter body 42 can be heated by the heating element inside the housing 10 in which the filter body 42 is accommodated. Accordingly, it is possible to suppress heat dissipation before the heated fuel is filtered by the filter body 42, and to suppress cooling of the fuel fuel before being filtered by the filter body 42. Thereby, clogging of the filter body 42 by wax can be prevented more reliably.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the above-described embodiment, the first heating element 81 and the second heating element 82 are configured by the two heating elements 80 electrically connected in parallel, but the present invention is not limited to this. Each heating element may be composed of one or three or more heating elements. In addition, the number of heating elements may be different among a plurality of heating elements.

  Moreover, in the said embodiment, the 1st temperature switch 91 and the 2nd temperature switch 92 are provided corresponding to the 1st heat generating body 81 and the 2nd heat generating body 82, and the output from a heat generating body is made into two steps according to fuel temperature. Although it was made to change, it is not limited to this. For example, it may be changed in three or more stages. Further, the output is not limited to a stepwise change according to the fuel temperature, but may be a continuous change.

  Moreover, in the said embodiment, although the supply fuel was heated with the heating unit 70 provided in the housing 10 of the fuel filter apparatus 1, it is not limited to this. What is necessary is just to be able to heat the fuel in the fuel flow path from the fuel tank 2 to the filter body 42. For example, a plurality of heating elements may be provided in the fuel pipe 6 on the upstream side of the fuel filter device 1.

  Moreover, in the said embodiment, although the deformation | transformation member was a bimetal plate, it is not limited to this. For example, the rod may be displaced by deformation (specifically, volume change) of wax sealed in the container body.

  In the above embodiment, the first temperature switch 91 and the second temperature switch 92, which are temperature-sensitive switch devices, are used to switch on / off the energization of the first heating element 81 and the second heating element 82. However, the present invention is not limited to this. Is not to be done. For example, the control device may switch on / off states of a plurality of switch devices corresponding to a plurality of heating elements based on detection values of a temperature sensor such as a thermistor to control energization to the plurality of heating elements. .

  In the above embodiment, the fuel supply device is a common rail fuel injection system, and the supply destination of the supplied fuel is the supply pump 3 or the like, but is not limited thereto. For example, the supply destination of the supplied fuel may be pump means such as a distributed fuel injection pump.

1 Fuel filter device 2 Fuel tank 3 Supply pump (supplier)
4 Common rail (supplier)
5 Injector (supplier)
21 Upstream passage (part of fuel flow passage)
42 Filter body 81 First heating element (heating element)
82 Second heating element (heating element)
91 First temperature switch (switch device, temperature-sensitive switch device)
92 Second temperature switch (switch device, temperature-sensitive switch device)

Claims (3)

A filter body (42) for filtering the fuel supplied from the fuel tank (2) to the supply destination (3, 4, 5);
A plurality of heating elements (81, 82) provided in a fuel flow path (21) from the fuel tank to the filter body and generating heat when energized to heat the supplied fuel;
A plurality of switch devices (91, 92) provided to correspond to the plurality of heating elements and for turning on / off energization of each of the plurality of heating elements,
The plurality of switch devices switch an on / off state according to a fuel temperature of the supplied fuel that circulates in an upstream portion of the fuel flow passage from an arrangement portion of the plurality of heating elements,
The fuel supply device, wherein the number of the switch devices that are turned on among the plurality of switch devices increases as the fuel temperature is lower.   Each of the plurality of switch devices has a deformable member (904) that deforms according to the fuel temperature, and is a temperature-sensitive switch device that opens and closes the contact pair (906, 907) as the deformable member deforms. The fuel supply apparatus according to claim 1, wherein the fuel supply apparatus is provided. A housing (10) for accommodating the filter body therein;
3. The fuel supply device according to claim 1, wherein the plurality of heating elements are disposed inside the housing. 4.

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