JP5303418B2 - Fuel supply device - Google Patents

Description

  The present invention relates to a fuel supply device that includes a plurality of fuel injection valves and a plurality of heaters, and injects fuel heated by the heaters with the fuel injection valves and supplies the fuel to an internal combustion engine.

  In an internal combustion engine that injects fuel with a fuel injection valve, it is necessary to warm the fuel supplied to the fuel injection valve in order to enable a smooth start even at low temperatures. Therefore, a fuel heating apparatus is known in which a heater is provided in a fuel supply pipe and fuel heated by the heater is supplied to a fuel injection valve (see, for example, Patent Document 1).

JP-A-5-26130

  By the way, in a multi-cylinder engine, a plurality of fuel injection valves are provided for each cylinder, and fuel is distributed to each fuel injection valve via a delivery pipe provided at the tip of a fuel supply pipe. The delivery pipe is generally formed in a cylindrical shape, and a plurality of fuel injection valves are attached along the axial direction of the delivery pipe, so that fuel flows from one end to the other end on the fuel pump side. For this reason, the fuel injection valve attached to the other end side is less likely to be supplied with fuel than the fuel injection valve attached to the one end side, and the amount of fuel supplied to the fuel supply valve is biased. There is a problem that the fuel injection amount is uneven.

  As a fuel supply device that can suppress such a problem, in a multi-cylinder engine in which a plurality of cylinders are arranged in a V shape or a horizontally opposed type, a delivery pipe is divided and a fuel injection valve provided in one delivery pipe is provided. International Publication No. 2003/008796 discloses a technique that reduces the deviation of the amount of fuel supplied to the fuel injection valve by reducing the number.

  However, as described in International Publication No. 2003/008796, even if the number of fuel injection valves supplied with fuel from one delivery pipe is reduced, the fuel injection valves are arranged along the axial direction of the delivery pipe. Therefore, the distribution distance of the fuel supplied to one end of the delivery pipe to each fuel injection valve becomes longer as the fuel injection valve attached to the other end side, and there is still a problem that the fuel injection amount is biased. . This problem is more desired to be solved for a fuel supply apparatus that heats fuel with a heater in order to smoothly start the internal combustion engine.

  The present invention has been devised to solve the problems imposed on the prior art, and a main object of the present invention is to provide each fuel injection in a fuel supply apparatus including a plurality of heaters and fuel injection valves. The purpose is to supply fuel so that the fuel injection amount from the valve becomes equal.

In order to solve such a problem, the first invention comprises a fuel supply pipe (2) and a tubular member extending substantially horizontally and forming one space therein, and the fuel supply pipe (2). A fuel case (4) for storing the fuel supplied by the fuel tank and a heater (heater member 7) for heating the fuel flowing out from the fuel case (4), respectively, and a plurality of heating chambers (8) defining each of the heating chambers (8) A fuel supply device (1) provided with a heater case (5) and a plurality of fuel injection valves (9) provided for each of the plurality of heater cases (5) and injecting fuel flowing out of the heater case (5) ), The fuel supply pipe (2) branches toward the downstream side in the direction in which the fuel flows, and has a plurality of distribution portions (distribution pipes 2c) for distributing the fuel to the fuel case (4). Case( ) Has a plurality of inlets for flowing each fuel from a plurality of distribution unit (2c) and (4i), a plurality of outlet ports for discharging the respective fuel into heater case (5) and (4o), Fuel supplied by a plurality of distribution sections (2c) of a fuel supply pipe is stored in the space and supplied from a plurality of outlets (4o) to a plurality of heater cases (5). The distances from 4i) to the corresponding outlets (4o) are set to be equal.

  According to the present invention, the fuel supply pipe has a plurality of distributors, and the plurality of inlets to which fuel is supplied by the distributors are formed in the fuel case, so that each inlet of the fuel case is formed. The fuel is supplied evenly (in terms of amount and pressure; the same applies hereinafter) to the area. Then, the distances from the respective inlets in the fuel case to the corresponding outlets were set to be equal, that is, the inlets were arranged according to the arrangement of the fuel injection valve and the heater case, so that they were supplied evenly. The fuel is supplied to the plurality of heater cases evenly. As a result, fuel is evenly supplied to the plurality of fuel injection valves, combustion in each cylinder is stabilized, and efficient internal combustion engine drive can be realized. In addition, the corresponding outlet mentioned here is a group of outlets (including one case) in which the closest inlets are common, and each fuel injection valve is in normal driving when injecting an equal amount of fuel. , And refers to an outlet to which most of the fuel is supplied from this common inlet.

  The second invention is characterized in that in the fuel supply device (1) according to the first invention, one inflow port (4i) is formed corresponding to the two outflow ports (4o).

  According to the present invention, fuel can be supplied from one inflow port to two outflow ports, so that the number of processing steps for providing the inflow port in the fuel case can be reduced. In addition, since the distance from an inflow port to a corresponding outflow port is set equally, ie, an inflow port is arrange | positioned in the intermediate position of two outflow ports, the fuel which flows in from each inflow port remains as it is two outflow ports. Flows evenly.

The third invention is the fuel supply device (1) according to the second invention, a fuel case (4), and outlet projecting upward direction a plurality of convex portions (4o) is formed (4a) At a position corresponding to the heater case (5), and the cross-sectional area of the portion (tubular portion 4b) between the convex portions (4a) where the inflow port (4i) is formed has a convex shape where the inflow port (4i) is not formed. It is characterized by being set larger than the cross-sectional area of the portion (tubular portion 4c) between the portions (4a).

  According to the present invention, the cross-sectional area from each inflow port to the corresponding two outflow ports is set larger than the cross-sectional area of the portion between the convex portions where the inflow port is not formed, so that the inflow from each inflow port. It is possible to make it difficult for the fuel to flow outside the corresponding outlet. Therefore, the fuel flowing from the inflow port to each outflow port can be held uniformly.

  According to a fourth aspect of the present invention, in the fuel supply device (1) according to any one of the first to third aspects, the plurality of inlets (4i) are arranged at positions lower than the plurality of outlets (4o). It is characterized by that.

  The fuel in the fuel case becomes warmer by the heat conduction from the heater toward the outflow side connected to the heater case, and the warm fuel rises and accumulates in the upper part of the fuel case. According to the present invention, the plurality of inflow ports are arranged at positions lower than the plurality of outflow ports, so that the fuel supplied by the distribution unit of the fuel supply pipe pushes up the fuel in the fuel case upward, and the warm fuel Is led to the outlet located at a relatively high position, so even if the fuel flowing into the fuel case from the inlet is cold, the fuel in the fuel case flows out from the outlet in order from the warmest to the fuel injection valve. Supplied. Therefore, the heat loss due to heat radiation from the fuel case can be reduced, and the heating efficiency of the heater, that is, the temperature increase rate of the supplied fuel with respect to the output of the heater can be prevented.

  The fifth invention is characterized in that, in the fuel supply device (1) according to the fourth invention, the plurality of inlets (4i) are arranged in the vicinity of the lower end of the fuel case (4).

  According to the present invention, the plurality of inflow ports are arranged in the vicinity of the lower end portion of the fuel case, so that the fuel in the lower portion of the fuel case is pushed upward by the fuel flowing in from the inflow port and guided to the outflow port. Therefore, fuel can be prevented from staying in the fuel case.

  Thus, according to the fuel supply device of the present invention, fuel can be supplied so that the fuel injection amounts from the plurality of fuel injection valves are equalized, and the internal combustion engine can be driven smoothly. it can.

It is a perspective view of the fuel supply device concerning an embodiment. It is a front view of the fuel supply device concerning an embodiment. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is explanatory drawing of the effect by the fuel supply apparatus which concerns on embodiment. It is explanatory drawing of the effect by the fuel supply apparatus which concerns on embodiment.

  Hereinafter, a fuel supply device 1 according to the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings. In addition, when indicating the direction for each member or each part, in the state where the fuel supply device 1 is installed on the engine of the automobile stopped on a horizontal flat road, the vertical direction is set as a reference and the vertical direction is set as the reference And right and left orthogonal to this shall be defined.

  As shown in FIGS. 1 and 2, the fuel supply device 1 of this embodiment provided for an in-line four-cylinder automobile alcohol engine (hereinafter, abbreviated as an engine, not shown) that uses ethanol as a main fuel. The fuel supply pipe 2, the tubular fuel case 4 for storing the fuel supplied by the fuel supply pipe 2, and the heater member 7 for heating the fuel flowing out from the fuel case 4, respectively, Four heater cases 5 each defining one heating chamber 8, and four fuel injection valves 9 that are provided for the four heater cases 5 and inject fuel that flows out of the heater cases 5, respectively. In addition, although the fuel case 4 and the heater case 5 which are formed as separate members in this embodiment are joined to each other, they may be formed as an integral member. Hereinafter, the fuel case 4 and the heater case 5 are collectively referred to as a case 3.

  The upstream end of the fuel supply pipe 2 is connected to a fuel pump (not shown) as fuel supply means, and when the ignition switch is switched from the ACC position to the IG position, the fuel pump is driven and a predetermined pressure is applied. Send the fuel with. The fuel supply pipe 2 is connected to the downstream end of the supply pipe 2a via the branch connector 2b located on the downstream side of the supply pipe 2a that is located on the upstream side and forms one fuel supply line. It has two distribution pipes 2c. Both distribution pipes 2c are connected to the fuel case 4 via connection connectors 2d connected to their downstream ends. That is, the fuel supply pipe 2 branches into two branches toward the downstream side in the direction in which the fuel flows, and the two distribution pipes 2 c distribute the fuel and supply the fuel to the fuel case 4.

  Both distribution pipes 2c are straight pipes each having a circular cross section, and have the same cross-sectional shape and the same length. The supply pipe 2a also has the same cross-sectional shape as the both distribution pipes 2c. Both distribution pipes 2c are linearly connected by a branch connector 2b, and the supply pipe 2a extends in parallel with one distribution pipe 2c toward the downstream side in the direction in which the fuel flows, and then bends 90%. The direction is changed, and the axis is connected to the branch connector 2b in a direction orthogonal to the axis common to both distribution pipes 2c. In other words, the supply pipe 2a is connected to the straight distribution pipe 2c at an angle of 90 degrees. On the other hand, the connection connectors 2d connected to the downstream ends of the both distribution pipes 2c are joined to the front wall 4f of the fuel case 4, and both the distribution pipes 2c are fueled toward the downstream side in the direction in which the fuel flows. After extending along the front wall 4f of the case 4, the connection connector 2d is connected to the front wall 4f of the fuel case 4 at an angle of 90 degrees.

  In the fuel supply pipe 2 configured in this way, two distribution pipes 2c having the same shape are connected to the supply pipe 2a at the same position at the same angle, and further have the same flow path shape and the same flow path length. Since it is connected to the fuel case 4, the fuel supplied by the supply pipe 2a is distributed to the two distribution pipes 2c by the branch connector 2b with the same amount and the same pressure, and the same condition (amount, pressure) by the connection connector 2d. , Angle) at two locations of the fuel case 4.

  The fuel case 4 is a flat tubular member having a flat front wall 4f and a rear wall 4g that extend in parallel and substantially perpendicular to each other, and that forms one space therein, and is supplied by the fuel supply pipe 2 The stored fuel is stored in this internal space, and the fuel is distributed to each heater case 5 with an equal pressure. The fuel case 4 extends substantially horizontally and includes four protrusions 4a protruding upward. These convex portions 4a are provided at positions that match the heater case 5 provided at the same pitch (same center distance) as the engine cylinder (not shown). More specifically, as shown well in the front view of FIG. 2, the four heater cases 5 are arranged in a row so that their axis lines 5X parallel to each other are substantially at the same interval. The part 4a is in the left-right direction so that the center line 4aX is closer to the center than the axis 5X of the heater case 5 in two of them located at both ends in the left-right direction (extending direction of the fuel case 4). In two of them located on the center side, the center line 4aX is arranged closer to the end than the axis 5X of the heater case 5. Therefore, the center-to-center distance l1 between the two convex portions 4a closer to the center is longer than the center-to-center distance l2 between the two convex portions 4a closer to the end.

  As shown in FIG. 2, the fuel case 4 includes three tubular portions 4 b and 4 c that allow the adjacent convex portions 4 a to communicate with each other between the four convex portions 4 a. These tubular portions 4b and 4c are formed so that the vertical dimension is smaller than that of the convex portion 4a, and the tubular portion 4c disposed in the center is more than the two tubular portions 4b having the same vertical dimension disposed at both ends. Further, the vertical dimension is formed smaller. In other words, the cross-sectional area (hereinafter simply referred to as the cross-sectional area) of the hollow portion of the tubular portion 4b disposed on both ends is set larger than the cross-sectional area of the tubular portion 4c disposed in the center. Moreover, since the center line 4aX of the convex part 4a is offset in the left-right direction with respect to the axis 5X of the heater case 5 as described above, the length of the tubular part 4b disposed at both ends is disposed in the center. It is longer than the length of the tubular portion 4c.

  The branch connector 2b of the fuel supply pipe 2 is disposed at a substantially central portion in the longitudinal direction of the fuel case 4, that is, between the two convex portions 4a disposed at the center, and on the front wall 4f of the fuel case 4 at the central tubular portion 4c. It is joined. On the other hand, the two connection connectors 2d are respectively disposed between the convex portions 4a disposed at both ends in the longitudinal direction and the convex portions 4a adjacent to the convex portions 4a. It is joined to the front wall 4f. Then, with reference to FIG. 3 as well, two inflow ports 4i are formed in the front wall 4f of the fuel case 4 at a position where both the connection connectors 2d are joined. Both inflow ports 4i are arranged at the same height in the lower end of the front wall 4f, more specifically in the vicinity of the lower end of the fuel case 4, and the fuel supplied by the distribution pipe 2c flows into the fuel case 4 respectively. Let

  As shown in FIG. 3, outflow ports 4 o are formed in the rear wall 4 g of the fuel case 4 in the four convex portions 4 a of the fuel case 4. These four outlets 4o are arranged at the upper part of the convex part 4a, more specifically, at the same height position near the upper end of the fuel case 4 and in the left-right direction position aligned with the axis 5X of the corresponding heater case 5. ing. These outlets 4o allow the fuel stored in the fuel case 4 to flow toward the corresponding heater cases 5.

  In the fuel case 4 formed in this way, since only two inflow ports 4i are formed for the four outflow ports 4o, the number of processing steps for providing the inflow ports 4i is reduced. In the fuel case 4, the distances from the left inlet 4 i to the two left outlets 4 o and the distances from the right inlet 4 i to the two right outlets 4 o are all equal. The fuel that has flowed in evenly from the four inlets 4i flows evenly to the four outlets 4o. Further, each flow path from the left inlet 4i to the two left outlets 4o and each flow path from the right inlet 4i to the two right outlets 4o are all in the shape and cross-sectional area in each cross section. Also by being equal, it is ensured that the fuel flows evenly to the four outlets 4o.

  The fuel case 4 extends substantially horizontally, and the cross-sectional area of the tubular portion 4b on both ends where the inflow port 4i is formed is set larger than the cross-sectional area of the central tubular portion 4c where the inflow port 4i is not formed. As a result, the fuel that has flowed in from each inflow port 4i is difficult to flow to other than the close outflow port 4o. Further, the length of the central tubular portion 4c is longer than the length of the tubular portions 4b on both ends, so that the fuel flowing in from the inflow port 4i is difficult to flow to other than the adjacent outflow port 4o. . Therefore, most of the fuel flowing in from one inflow port 4i flows to two outflow ports 4o arranged close to each other, and the uniformity of the fuel flowing from the inflow port 4i to each outflow port 4o is maintained. That is, two outflow ports 4o arranged close to each other so as to sandwich one inflow port 4i have substantially the entire amount of fuel during normal driving in which each fuel injection valve 9 injects an equal amount of fuel with respect to the inflow port 4i. Will have a corresponding relationship.

  The heater case 5 is provided on each of the rear walls 4g of the fuel case 4 where the convex portions 4a are formed. Each heater case 5 has a substantially cylindrical shape whose axis 5X extends in a substantially vertical direction and a long cylindrical shape whose axial length is longer than the diameter, and defines a heating chamber 8 inside thereof. Yes. The heater case 5 is formed with an inflow port 5i through which fuel flowing out from the outflow port 4o of the fuel case 4 and an outflow port 5o through which fuel flows out toward the fuel injection valve 9 are formed. An opening 5a for mounting the heater 6 is formed at the upper shaft end.

  The heater 6 has a rod-shaped heater member 7 at its tip, and is attached to the heater case 5 in such a manner that the heater member 7 is inserted downward into the opening 5a. The heater member 7 is disposed coaxially with the axis 5X of the heater case 5 so that the lower end 7a thereof forms a predetermined gap from the bottom wall 5b of the heater case 5, and is accommodated in the heater case 5. . The heater member 7 is a heat generating member having a heat generating portion 7h that incorporates a heating wire. The heater member 7 is in a heat generating state that retains a relatively large amount of heat by transmitting heat from the heating wire, and heats surrounding fuel. In addition, the heat generating part 7h is set to about 70% to 80% on the tip side of the heater member 7 in the present embodiment. The heater 6 appropriately heats the fuel in the heating chamber 8 that has flowed out of the fuel case 4 by performing duty control from the battery to the heating wire by the ECU according to the temperature of the engine cooling water or the like.

  The fuel injection valve 9 has an axial shape, and is provided on the downstream side in the fuel flow direction with respect to the heater 6 and in the intake passage of the engine. As shown in FIGS. 1 and 3, the heater case 5 and the fuel injection valve 9 are connected to each other as a fuel supply device 1 via a base plate 10 for integrating the members. Since the case 5 and the fuel injection valve 9 are attached to the single base plate 10, the assembly to the engine is facilitated, and the assembly accuracy of the fuel injection valve 9 to the engine is enhanced. A through hole 10 a is formed in the base plate 10 at a position aligned with the outlet 5 o of the heater case 5. The fuel injection valve 9 has an inflow port 9i at the shaft end on the base end side, and is attached to the base plate 10 so that the inflow port 9i communicates with the heating chamber 8 through the through hole 10a. The fuel injection valve 9 incorporates an electromagnetic valve that is driven and controlled by the ECU, and injects fuel flowing out from the heater case 5 at a predetermined time by a predetermined amount corresponding to the opening / closing time of the electromagnetic valve. To supply.

  Returning to FIG. 3, the inlet 5 i of the heater case 5 is disposed in the vicinity of the upper end of the cylindrical side wall 5 s that defines the side of the heating chamber 8, and the outlet 5 o of the heater case 5 is in the vicinity of the lower end of the side wall 5 s. Has been placed. The fuel injection valve 9 is installed so that its axis 9X is horizontal, that is, orthogonal to the axis 5X of the heater case 5. Therefore, the inflow port 5i and the outflow port 5o are disposed on the opposite sides of the heat generating portion 7h, and the flow path axis at the inflow port 5i is offset above the flow path axis at the outflow port 5o. It becomes.

  According to the heater case 5 formed in this way, when the heat generating portion 7 h generates heat, the fuel around the heat generating portion 7 h is heated, and the warmed fuel moves upward in the heating chamber 8. And since the cold fuel which flowed into the heating chamber 8 from the inflow port 5i moves horizontally in the heating chamber 8 and then moves downward, a convection that circulates in the heating chamber 8 occurs. When the fuel is overheated by the heat generating portion 7h, the fuel around the heat generating portion 7h is vaporized to form bubbles, and the bubbles rise so as to collect on the inflow port 5i side by convection. Then, the bubbles collected on the inlet 5i side are cooled by the cold fuel flowing from the inlet 5i and liquefy again. Even if the liquid rises past the inlet 5i without being liquefied, the bubbles accumulate in the upper part of the heating chamber 8. And since the heat generating part 7h is not set in the upper part of the heater member 7, the bubbles accumulated in the upper part of the heating chamber 8 are cooled by the cold fuel flowing in from the inflow port 5i and liquefy again. This prevents fuel from being scooped by the heater 6. Further, since the outlet 5o is disposed in the heater case 5 near the lower part on the side opposite to the inlet 5i where the bubbles gather, the bubbles hardly flow out from the outlet 5o toward the fuel injection valve 9, and the engine 5 Can be driven stably.

  As described above, the fuel in the heater case 5 is heated by the heater member 7, and this heat is transmitted to the fuel or the case 3, so that the fuel in the fuel case 4 is connected to the heater case 5. The warmed fuel rises and accumulates in the upper part of the fuel case 4. And since each inflow port 4i is arrange | positioned in the position lower than each outflow port 4o, as shown in FIG. 4, the fuel supplied by distribution pipe 2c pushes up the fuel in the fuel case 4, and is warm. The fuel is guided to the outlet 4o side as indicated by a broken line. Therefore, even if the fuel flowing into the fuel case 4 from the inlet 4i is cold, the fuel in the fuel case 4 flows out from the outlet 4o in order from the warmest and is supplied to the fuel injection valve 9. Accordingly, heat loss due to heat radiation from the fuel case 4 is reduced, and the heating efficiency of the heater 6, that is, the temperature increase rate of the supplied fuel with respect to the output of the heater 6 is prevented from being reduced. The fuel injection valve 6 can be heated to a target temperature or higher.

  Further, in the fuel case 4, each inflow port 4 i is disposed in the vicinity of the lower end of the fuel case 4, so that the fuel in the lower part of the fuel case 4 is moved upward by the fuel flowing into the fuel case 4 from the inflow port 4 i. Therefore, the fuel is prevented from staying in the fuel case 4.

  On the other hand, as described above, the fuel that has evenly flown from the two inlets 4 i of the fuel case 4 flows equally toward the corresponding two heater cases 5 and fuel injection valves 9. Therefore, as shown in FIG. 5, since the four fuel injection valves 9 inject an equal amount of fuel during normal driving, the fuel is evenly warmed by each heater 6 and the fuel supplied to each fuel injection valve 9 The temperature becomes substantially the same. As a result, smooth driving of the engine is realized.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above embodiment, the fuel supply device 1 according to the present invention is applied to an alcohol engine that uses ethanol as a main fuel, but it can also be applied to an engine that uses other components as fuel, such as light oil and gasoline, Of course, the present invention can be applied to engines other than the in-line four cylinders. In the above embodiment, the fuel supply pipe 2 is only branched into two branches, but the fuel supply pipe 2 is branched into three branches, and each distribution pipe 2c is further branched into two branches. Form may be sufficient. Further, in the fuel case 4, the two inflow ports 4 i are formed for the four outflow ports 4 o, but it may be configured such that four inflow ports 4 i are formed. The number of outlets is not limited to the above embodiment. In addition to these changes, the specific configuration and arrangement of each member can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Fuel supply apparatus 2 Fuel supply pipe 2c Distribution pipe 3 Case 4 Fuel case 4i Inlet 4o Outlet 4a Convex part 4b, 4c Tubular part 5 Heater case 6 Heater 7 Heater member 8 Heating chamber 9 Fuel injection valve

Claims (5)

A fuel supply pipe;
A fuel case that extends substantially horizontally and includes a tubular member that forms one space therein, and stores fuel supplied by the fuel supply pipe;
A plurality of heater cases each having a heater for heating the fuel flowing out of the fuel case and defining a heating chamber;
A plurality of fuel injection valves provided for the plurality of heater cases, respectively, for injecting fuel flowing out of the heater cases;
The fuel supply pipe has a plurality of distribution portions that branch toward the downstream side in the direction in which the fuel flows, and each distributes the fuel to the fuel case ,
The fuel case has a plurality of inflow ports through which fuel flows in from the plurality of distribution parts, and a plurality of outflow ports through which fuel flows out toward the heater case, respectively, and a plurality of distributions in the fuel supply pipe The fuel supplied by the unit is stored in the space and supplied to the plurality of heater cases from the plurality of outlets, and the distances from the plurality of inlets to the corresponding outlets are set equally. The fuel supply apparatus characterized by the above-mentioned.   The fuel supply device according to claim 1, wherein one inflow port is formed corresponding to two outflow ports. Said fuel case has a plurality of convex portions and the outlet projecting upward direction is formed at a position corresponding to the heater case, the cross-sectional area of the portion between the convex portion to which the inlet is formed, The fuel supply device according to claim 2, wherein the fuel supply device is set to be larger than a cross-sectional area of a portion between the convex portions where the inflow port is not formed.   The fuel supply device according to any one of claims 1 to 3, wherein the plurality of inlets are arranged at positions lower than the plurality of outlets.   The fuel supply device according to claim 4, wherein the plurality of inflow ports are disposed in the vicinity of a lower end portion of the fuel case.

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