JP6317953B2 - Fuel filter device - Google Patents

Description

  The present invention relates to a fuel filter device provided in a supply flow path for supplying fuel from a fuel tank to an engine.

  Some engines of power machines that operate using light oil, kerosene, gasoline, or the like as fuel are provided with a fuel injection supply system that supplies fuel in a mist form into a cylinder or into an intake port. This fuel injection supply system includes a fuel tank, a fuel pump, and an injection nozzle (injector). The fuel supply flow path connecting the fuel tank and the fuel pump captures foreign matters such as dust and dust contained in the fuel. A fuel filter device for removal is provided (see, for example, Patent Document 1).

JP 2009-125737 A

  By the way, such a fuel injection supply system is configured to suck up fuel from a fuel tank via a fuel filter by a fuel pump and supply the fuel to an injection nozzle. When the fuel filter is installed at the position, the fuel flow resistance increases, and the fuel supply amount may be insufficient.

  The present invention has been made in view of such a problem, and supplies a necessary amount of fuel to an injection nozzle even when a highly accurate fuel filter or a fuel filter is installed at a remote position. It is an object of the present invention to provide a fuel filter device that can be used.

To achieve the above object, the present onset Ming, the fuel filter device provided in the supply passage for supplying the engine by the fuel pump fuel from the fuel tank, and a filter head that the fuel inlet and outlet are formed A filter case attached to the filter head; and a filter element provided in the filter case , wherein the filter head has an element arrangement space in the filter case in which the filter element is provided from the inflow port. And an outflow path that leads from the element arrangement space to the outflow port. And an electric pump provided in the outflow passage of the filter head, a check valve provided on the suction side of the electric pump in the outflow passage and allowing only the flow of fuel in the direction of being sucked into the electric pump , A fuel storage chamber (for example, a steam separation chamber 55 in the embodiment) that is formed on the discharge side of the electric pump in the outflow passage and stores fuel that flows out from the outlet , and the electric pump is the fuel pump Driven by the suction force of the fuel pump and the electric pump, the fuel from the fuel tank is caused to flow from the inlet through the inflow path into the element arrangement space and through the filter element. Later, it flows out from the outlet through the check valve and the fuel storage chamber provided in the outflow passage. Configured so that.

In the fuel filter device having the above-described configuration, a bypass passage formed so as to connect the outflow passage closer to the element arrangement space than the check valve and the fuel storage chamber, and provided in the bypass passage, A bypass valve that opens due to the suction force of the fuel pump when the electric pump is stopped, and causes the fuel in the outflow path closer to the element arrangement space than the check valve to flow into the fuel storage chamber. It is preferred that

  Further, in the fuel filter device configured as described above, an overflow outlet formed in the filter head, an overflow passage formed so as to connect the overflow outlet and the fuel storage chamber, and the overflow passage are provided. And an overflow valve that opens when the fuel on the fuel storage chamber side is equal to or higher than a predetermined pressure and causes the air stored in the fuel storage chamber to flow out from the overflow outlet together with the fuel in the fuel storage chamber. Is preferred.

According to the fuel filter device of the present invention, the electric pump is provided in the outflow passage of the filter head. Therefore, the amount of fuel supplied to the injection nozzle by the electric pump can be increased, and even when a highly accurate fuel filter or a fuel filter is installed at a remote position, the required amount of fuel is injected. Can be supplied to the nozzle.

In addition, a check valve provided on the suction side of the electric pump in the outflow passage of the filter head and a fuel storage chamber formed on the discharge side of the electric pump in the outflow passage are provided. Therefore, even when the filter case is removed from the filter head and the filter element is replaced, it is possible to keep the fuel in the electric pump . Therefore, after replacing the filter element, the fuel can be sucked from the inlet of the filter head as soon as the electric pump is restarted, and the supply of fuel can be resumed by filling the filter case (filter element) with the fuel. it can. At this time, air is mainly discharged from the outlet due to the steam separation effect of the fuel storage chamber, the fuel is not discharged but remains in the fuel storage chamber, and the electric pump is filled with fuel. Can be sucked in from the inlet of the filter head. When the check valve and the fuel storage chamber are not provided as in the fuel filter device according to the present invention, when the filter element is replaced, there is no fuel in the electric pump (empty state) It becomes therefore impossible to completely suck fuel electric pump runs idle even restart the electric pump.

Further, in the fuel filter device configured as described above, a bypass passage formed so as to connect the outflow passage on the element arrangement space side with respect to the check valve and the fuel storage chamber, and a bypass valve provided in the bypass passage. With this configuration, even if the electric pump stops for some reason, the fuel that has passed through the filter element is bypassed by opening the Pivas valve by the suction force of the fuel pump provided on the injection nozzle side. The fuel can be supplied to the fuel storage chamber through the passage and supplied from the outlet toward the injection nozzle. That is, even when the electric pump is stopped for some reason, it is possible to bypass the electric pump and supply the fuel toward the injection nozzle.

In the fuel filter device configured as described above, an overflow outlet formed in the filter head, an overflow passage formed so as to connect the overflow outlet and the fuel storage chamber, and an overflow valve provided in the overflow passage; If it is set as the structure provided with this, the air isolate | separated from the fuel in the fuel storage chamber with the fuel discharged excessively by the electric pump can be discharged | emitted from an overflow outflow port via an overflow flow path and an overflow valve.

It is a simplified lineblock diagram of a fuel injection supply system provided with a fuel filter device concerning the present invention. It is sectional drawing of the fuel filter apparatus which concerns on this invention. 1 is a plan view of a fuel filter device according to the present invention. It is an expanded sectional view (a part of sectional view of Drawing 1) of the fuel filter device concerning the present invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a simplified configuration of an engine fuel injection supply system including a fuel filter device 1 according to the present invention.

  This fuel injection supply system includes a fuel tank T that stores fuel, a fuel pump P that pumps fuel, and an injection nozzle that atomizes the fuel pumped by the fuel pump P and injects it into an air supply pipe or combustion chamber of an engine. N (injector), and a fuel filter device 1 that is provided in a fuel supply passage that connects the fuel tank T and the fuel pump P and that supplements and removes foreign matters such as dust contained in the fuel from the fuel tank T. Has been.

  As shown in FIGS. 2 to 4, the fuel filter device 1 includes a filter head 20, a filter case 30 having an element disposition space 10 therein and detachably screwed to the filter head 20, and a filter case 30 and the filter element 40 arranged to extend in the vertical direction in the element arrangement space 10. The fuel filter device 1 is configured such that an element assembly configured by disposing a filter element 40 in a filter case 30 is attached to and detached from the filter head 20 for replacement.

  The filter head 20 has an inlet 21 to which a fuel supply channel connected to the fuel tank T is connected, an inlet 22 connected to the element arrangement space 10 from the inlet 21, and a fuel supply flow connected to the fuel pump P. An outlet 23 to which the path is connected and an outlet path 24 connected to the outlet 23 from the element disposition space 10 are formed. A cylindrical projecting portion 25 projecting downward is formed at a substantially central portion of the lower surface of the filter head 20, and a lower end portion of the outflow passage 24 extends vertically in the projecting portion 25 and is opened at the lower end thereof. Has been.

  An electric pump 50 is provided in the outflow path 24 of the filter head 20. The electric pump 50 is constituted by a gear pump, and the pump gear 51 of the electric pump 50 is disposed in the outflow path 24. In the fuel filter device 1, by driving the electric pump 50, fuel is sucked from the inflow port 21 to flow into the element arrangement space 10 through the inflow path 22, passes through the filter element 40, and then flows through the outflow path 24. The outlet 23 can be made to flow toward the fuel pump P.

  Only the fuel flow in the direction of being sucked into the electric pump 50 is allowed at the position on the suction side of the electric pump 50 in the outflow path 24 (element arrangement space 10 side with respect to the pump gear 51) (the flow in the reverse direction is restricted). ) A check valve 53 is provided. On the other hand, at the discharge side position of the electric pump 50 in the outflow path 24, a steam separation chamber 55 for storing the fuel that flows out from the outlet 23 is formed. The steaming liquid separation chamber 55 has sufficient space for steaming separation in order to restart the electric pump 50 and discharge the air in the filter case 30 after replacing the filter element 40 as will be described later. Is formed. The steam liquid separation chamber 55 corresponds to the fuel storage chamber described in the claims.

  In the filter head 20, a bypass channel 56 that connects the outflow path 24 closer to the element disposition space 10 than the check valve 53 and the lower portion of the steam separation chamber 55 is formed. A bypass valve 57 is provided at the opening of the bypass flow channel 56 on the side of the steam separation chamber 55. The bypass valve 57 includes a valve thin plate 57a that opens and closes the bypass flow path 56, and a valve stopper 57b that restricts the valve thin plate 57a from opening more than a predetermined amount. The bypass valve 57 is configured such that when the electric pump 50 is driven, the valve thin plate 57a is closed to cut off the flow of fuel, and when the electric pump 50 is stopped, the valve thin plate 57a is pulled by the suction force of the fuel pump P. The fuel in the outflow passage 24 closer to the element arrangement space 10 than the check valve 53 is opened to flow into the steam separation chamber 55.

  Further, the filter head 20 is formed with an overflow outlet 58 to which a fuel return passage connected to the fuel tank T is connected, and an overflow passage 59 connected to the overflow outlet 58 from the top of the steam separation chamber 55. ing. An overflow valve 60 is provided in the overflow channel 59. The overflow valve 60 is configured to open when the fuel in the steam separation chamber 55 is equal to or higher than a predetermined pressure so that the fuel in the steam separation chamber 55 flows out from the overflow outlet 58 via the overflow channel 59. Yes. A fuel injection port 27 and a fuel injection channel (not shown) connected from the fuel injection port 27 to the steam separation chamber 55 are formed on the upper surface of the filter head 20 (see FIG. 3).

  The filter case 30 is formed in a bottomed cylindrical shape that opens upward, and is configured such that the filter element 40 is disposed in the internal element disposition space 10. A male screw 31 is formed on the upper outer peripheral surface of the filter case 30. By screwing the male screw 31 and a female screw 28 formed on the lower inner peripheral surface of the filter head 20, the filter case 30 is attached to the filter head 20. Is detachably attached. A ring-shaped seal ring 35 is provided at the screwed portion, and the seal ring 35 prevents fuel in the element arrangement space 10 from leaking to the outside.

  A plurality of ribs 32 extending in the vertical direction along the side wall are provided on the inner bottom portion of the filter case 30. Filter elements 40 are placed on these ribs 32. In the center of the bottom of the filter case 30, a discharge path 33 is formed for discharging separated water that has separated from the fuel and settled. A drain plug 13 having a discharge hole 13 a is screwed into the discharge path 33. A gasket 14 is provided at the total screw portion, and the gasket 14 prevents the separated water and fuel from leaking outside except when the separated water is discharged. A float 12 made of a material that is lighter than the specific gravity of water and heavier than the specific gravity of fuel is disposed at the inner bottom of the filter case 30. The amount of the separated water accumulated can be determined by the position of the float 12.

  The filter element 40 is formed in a cylindrical shape in which a filter medium 42 folded in a bellows shape is wound around an inner cylinder 41 made of a punch sheet or the like having a large number of small holes 41a, and extends vertically. ing. A disc-shaped upper plate 43 having an opening 43 a at the center is attached to the upper ends of the inner cylinder 41 and the filter medium 42. On the other hand, a disk-shaped lower plate 44 is attached to the lower ends of the inner cylinder 41 and the filter medium 42.

  In the present embodiment, the filter medium 42 bent in a bellows shape is wound around the inner cylinder 41, but the filter medium is not limited to such a configuration. For example, it may be constituted by a glass fiber having a predetermined thickness, a non-woven fabric formed in a cylindrical shape, a combination of these materials, or a sintered product formed in a cylindrical shape. Depending on the fuel to be filtered, foreign matter to be removed, etc., the material and shape can be optimized.

  In the fuel filter device 1 configured as described above, the filter element 40 is installed in the filter case 30, and the protruding portion 25 (outflow path 24) of the filter head 20 passes through the opening 43 a of the upper plate 43 of the filter element 40. The filter case 30 is attached to the lower surface of the filter head 20 by protruding the male thread 31 of the filter case 30 into the female thread 28 of the filter head 20 so as to protrude into the internal space of the filter element 40. A ring-shaped seal ring 46 is provided at an engagement portion between the protruding portion 25 of the filter head 20 and the upper plate 43, and the fuel in the element disposition space 10 is brought into the internal space of the filter element 40 by the seal ring 46. Preventing intrusion.

  In the fuel filter device 1 assembled in this way, the electric pump 50 is normally driven, and the fuel from the fuel tank T is sucked in from the inlet 21 by the suction force of the fuel pump P and the suction force of the electric pump 50. After flowing into the element arrangement space 10 of the filter case 30 through the passage 22 and passing through the filter medium 42 of the filter element 40, the check valve 53, the electric pump 50 and the steam separation chamber 55 provided in the outflow passage 24. It is made to supply toward the fuel pump P from the outflow port 23 through.

  At this time, for example, in the case where the injection amount of the injection nozzle N is decreased, the overflow valve 60 provided in the filter head 20 when the fuel pressure in the steam separation chamber 55 becomes larger than a predetermined pressure. Is opened, and the fuel in the steam separation chamber 55 is returned from the overflow outlet 58 toward the fuel tank T via the overflow channel 59.

  When the electric pump 50 is stopped for some reason, the bypass valve 57 provided in the filter head 20 is opened by the suction force of the fuel pump P, and the fuel that has passed through the filter element 40 passes through the bypass flow path 56. The steam can be supplied to the fuel pump P from the outlet 23. As described above, in the fuel filter device 1, even when the electric pump 50 is stopped for some reason, the electric pump 50 can be bypassed to supply the fuel to the fuel pump P.

  In such a fuel filter device 1, the foreign matter removing ability is reduced due to clogging of the filter medium 42 of the filter element 40. In this case, the filter element 40 is replaced with a new filter element 40. When replacing the filter element 40, the drain plug 13 provided at the bottom of the filter case 30 is loosened to discharge the fuel in the element arrangement space 10 from the discharge path 33 to the outside, and the filter case 30 is removed from the filter head 20. . At this time, the check valve 53 provided in the outflow passage 24 of the filter head 20 restricts the fuel on the electric pump 50 side from flowing out to the element disposition space 10 side. Therefore, even when the filter case 30 is removed from the filter head 20, it is possible to keep the fuel in the electric pump 50. Accordingly, after the filter case 30 having the new filter element 40 is attached to the filter head 20 in the same manner as described above, the fuel can be sucked from the inlet 21 as soon as the electric pump 50 is restarted. The fuel supply can be restarted by filling the (filter element 40) with fuel. At this time, the steam separation space 55 required to restart the electric pump 50 and exhaust all the air in the filter case 30 is secured by the steam separation chamber 55. Furthermore, the air in the filter case 30 is separated from the fuel in the steam liquid separation chamber 55, and the air can be discharged from the overflow outlet 58 through the overflow channel 59 and the overflow valve 60 together with the fuel. Yes.

  As described above, according to the fuel filter device 1, the electric pump 50 is provided in the outflow path 24 of the filter head 20. Therefore, the amount of fuel supplied to the injection nozzle N can be increased by the suction force of the electric pump 50, and even if a highly accurate fuel filter or a fuel filter is installed at a remote position, it is necessary. An amount of fuel can be supplied to the injection nozzle N.

  In addition, a check valve 53 provided on the suction side of the electric pump 50 in the outflow path 24 of the filter head 20 and a steam separation chamber 55 formed on the discharge side of the electric pump 50 in the outflow path 24 are provided. Therefore, even when the filter case 30 is removed from the filter head 20 and the filter element 40 is replaced, it is possible to keep the fuel in the electric pump 50. Therefore, after replacing the filter element 40, as soon as the electric pump 50 is restarted, the fuel can be sucked from the inlet 21 of the filter head 20, and the inside of the filter case 30 (filter element 40) is filled with the fuel. Supply can be resumed. At this time, air is mainly discharged from the outlet 23 due to the steam separating effect of the steam separating chamber 55, the fuel is not discharged but remains in the steam separating chamber 55, and the electric pump 50 is filled with fuel. Therefore, the fuel can be continuously sucked from the inlet 21 of the filter head 20.

  Further, a bypass passage 56 formed so as to connect the outflow passage 24 on the element arrangement space 10 side with respect to the check valve 53 and the steam separation chamber 55, and a bypass valve 57 provided in the bypass passage 56 are provided. I have. Therefore, even when the electric pump 50 is stopped for some reason, the fuel that has passed through the filter element 40 with the bypass valve 57 opened by the suction force of the fuel pump P provided on the injection nozzle N side is bypassed. The fuel can be supplied from the outlet 23 toward the injection nozzle N through the passage 56 through the steam separation chamber 55. That is, even when the electric pump 50 is stopped for some reason, the fuel can be supplied toward the injection nozzle N by bypassing the electric pump 50.

  Further, an overflow outlet 58 formed in the filter head 20, an overflow passage 59 formed so as to connect the overflow outlet 58 and the steam separation chamber 55, and an overflow valve 60 provided in the overflow passage 59 It has. Therefore, the air separated from the fuel in the steam separation chamber 55 together with the fuel discharged excessively by the electric pump 50 can be discharged from the overflow outlet 58 via the overflow channel 59 and the overflow valve 60.

  Although the embodiment according to the present invention has been described so far, the scope of the present invention is not limited to that shown in the above-described embodiment. For example, in the above-described embodiment, the filter of the type in which the filter element 40 can be attached to and detached from the filter case 30 has been described. However, the present invention can also be applied to a cartridge type filter in which the filter case and the filter element are integrated. it can.

DESCRIPTION OF SYMBOLS 1 Fuel filter apparatus 20 Filter head 22 Inflow path 24 Outflow path 30 Filter case 40 Filter element 50 Electric pump (pressure feed pump)
53 Check valve 55 Steam separation chamber (fuel storage chamber)
56 Bypass passage 57 Bypass valve 58 Overflow outlet 59 Overflow passage 60 Overflow valve

Claims (3)

In a fuel filter device provided in a supply passage for supplying fuel from a fuel tank to a prime mover by a fuel pump
A filter head having a fuel inlet and outlet, a filter case attached to the filter head, and a filter element provided in the filter case ;
The filter head is formed with an inflow path that leads from the inflow port to the element arrangement space in the filter case in which the filter element is provided, and an outflow path that leads from the element arrangement space to the outflow port,
An electric pump provided in the outflow passage of the filter head;
A check valve that is provided on the suction side of the electric pump in the outflow passage and allows only the flow of fuel in the direction of being sucked into the electric pump ;
A fuel storage chamber that is formed on the discharge side of the electric pump in the outflow passage and stores fuel that flows out from the outlet ;
The electric pump is driven together with the fuel pump, and by the suction force of the fuel pump and the electric pump, the fuel from the fuel tank is caused to flow from the inlet through the inflow path into the element arrangement space, A fuel filter device configured to flow out from the outlet through the check valve and the fuel storage chamber provided in the outflow passage after passing through the filter element . A bypass passage formed so as to connect the outflow passage on the element arrangement space side with respect to the check valve and the fuel storage chamber;
Provided in the bypass flow path and opened by the suction force of the fuel pump when the electric pump is stopped, the fuel in the outflow path closer to the element arrangement space than the check valve is supplied to the fuel storage chamber The fuel filter device according to claim 1, further comprising a bypass valve that flows into the fuel cell. An overflow outlet formed in the filter head;
An overflow channel formed so as to connect the overflow outlet and the fuel storage chamber;
An overflow valve that is provided in the overflow channel and opens when the fuel on the fuel storage chamber side is equal to or higher than a predetermined pressure and causes the air stored in the fuel storage chamber to flow out from the overflow outlet together with the fuel in the fuel storage chamber; The fuel filter device according to claim 1, further comprising:

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