JP2011074781A - Fuel supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply device which comprises a plurality of fuel injection valves in which the heating efficiency of the heater is increased by uniformizing the temperature of the fuel supplied to the fuel injection valves and sequentially supplying the fuel heated by the heater to the fuel injection valves. <P>SOLUTION: This fuel supply device 1 includes a case 3 which stores fuel and comprises a heater member 7 for heating the fuel and four fuel injection valves 9 for injecting the fuel flowing out of the case 3. The case 3 includes a generally tubular fuel case 4 and four heater cases 5 having heater members 7, respectively. The fuel case 4 is formed so as to extend generally horizontally and comprises four upward projections 4a at the positions corresponding to the fuel injection valves 9. Flow ports 3p allowing the fuel to flow toward the fuel injection valves 9 are formed in the projections 4a, respectively. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel supply device that includes a plurality of fuel injection valves and a case having 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 uses a fuel injection valve to inject fuel, 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).

  By the way, in a multi-cylinder engine, a plurality of fuel injection valves are provided for each cylinder, and fuel is supplied to each fuel injection valve via a fuel distributor provided at the tip of a fuel supply pipe. The fuel distributor is generally horizontally disposed, and normally the inside is filled with fuel. However, when the fuel becomes hot and vapor is generated, the liquid level is pushed down by the vapor, and the liquid fuel and vapor are contained in the inside. Will be mixed. In this state, if the vehicle turns suddenly, suddenly accelerates or decelerates, or runs on a cant road or slope, and the liquid level is inclined with respect to the distributor, fuel is not supplied to some of the fuel injection valves. Therefore, in order to solve such a problem, only the connection portion with the fuel injection valve in the fuel distribution portion protrudes downward so that the fuel is accumulated in the connection portion with the fuel injection valve even if the liquid level is inclined. This technique has been proposed (see Patent Document 2).

JP-A-5-26130 Japanese Utility Model Publication No. 1-74361

  However, according to the configuration described in Patent Document 2, in the case of the fuel supply device in which the fuel heating device is provided on the upstream side of the fuel injection valve as described in Patent Document 1, the fuel heated by the heater rises. Since cold fuel is stored in the lower protruding portion of the fuel distributor, this cold fuel is supplied to the fuel injection valve, and there is a problem that warm fuel cannot be supplied to the fuel injection valve. Further, in the case of such a fuel supply device, when the horizontally disposed fuel distribution section is inclined due to a sudden turn or the like, the warm fuel moves upward in the fuel distribution section and is supplied to the fuel injection valve located on the upper side. As a result, there is a possibility that the temperature of the fuel supplied between the lower fuel injection valve and the upper fuel injection valve is different, and the driving of the internal combustion engine becomes unstable.

  The present invention has been devised to solve such problems imposed on the prior art, and its main purpose is to equalize the fuel temperature supplied to the plurality of fuel injection valves, An object of the present invention is to provide a fuel supply device that can increase the heating efficiency of a heater by sequentially supplying fuel heated by a heater to a fuel injection valve.

  In order to solve such a problem, the first invention stores a fuel and injects the fuel flowing out from the case (3) having a heater (6) for heating the fuel and the case (3). In the fuel supply device (1) provided with a plurality of fuel injection valves (9), the case (3) extends substantially horizontally and has a plurality of protrusions (4a) protruding upward as a fuel injection valve ( The distribution port (3p) is formed in each of the plurality of convex portions (4a) through which fuel flows toward the fuel injection valve (9).

  According to the present invention, the fuel heated by the heater rises in the case and collects in the plurality of convex portions, and is distributed to the fuel injection valves through the circulation ports provided in the convex portions. Therefore, warm fuel is sequentially supplied to the fuel supply valve, and heat loss due to heat radiation can be reduced, so that 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 increased. Further, since the horizontally arranged case has a plurality of convex portions, even if the case is inclined due to a sudden turn or the like, the warm fuel remains in the convex portions, and the fuel injection valve on the lower side also has a warm fuel. Therefore, it is possible to prevent the driving of the internal combustion engine from becoming unstable.

  Further, according to a second aspect of the present invention, in the fuel supply device (1) according to the first aspect of the present invention, the case (3) is formed with an inflow port (3i) through which fuel flows in, and the inflow port (3i) is a flow port ( It is characterized by being arranged at a position lower than 3p).

  According to this invention, since the inflow port is arranged at a position lower than the circulation port, even if cold fuel flows into the case from the inflow port, the warm fuel is pushed up and sequentially from the circulation port to the fuel injection valve. To be supplied. Accordingly, it is possible to prevent a reduction in the heating efficiency of the heater.

  The third invention is characterized in that, in the fuel supply device (1) according to the second invention, the inlet (3i) is arranged in the vicinity of the lower end of the case (3).

  According to this invention, since the inflow port is disposed near the lower end of the case, the fuel in the lower part of the case is pushed upward by the fuel flowing into the case and guided to the circulation port. It is possible to prevent the fuel from staying in the tank.

  As described above, according to the present invention, the fuel heated by the heater is sequentially supplied to the fuel injection valve to increase the heating efficiency of the heater, and the temperature of the fuel supplied to the plurality of fuel injection valves can be equalized. 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. The fuel case 4 and the heater case 5 constitute the case 3 described in the claims. 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.

  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 fuel flow direction, and the two distribution pipes 2c supply the fuel to the fuel case 4 while distributing the fuel.

  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 as described above, two distribution pipes 2c having the same shape are connected to the supply pipe 2a at the same position and 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 extending in parallel and substantially vertically, and forming 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 on 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 connecting connectors 2d are located between the convex portions 4a arranged at both ends in the longitudinal direction and the convex portions 4a adjacent to the convex portions 4a, more specifically at the middle position of the center line 4aX of both convex portions 4a. They are respectively arranged and joined to the front wall 4f of the fuel case 4 at the tubular portions 4b on both ends. 3 will be described with reference to FIG. 3. Specifically, in the case 3, two inflow ports 3 i are formed at the position where the two connection connectors 2 d on the front wall 4 f of the fuel case 4 are joined. Has been. Both inflow ports 3i are arranged at the same height in the lower end of the front wall 4f, more specifically in the vicinity of the lower end portion of the fuel case 4, and allow the fuel supplied by the distribution pipe 2c to flow into the case 3, respectively. .

  As shown in FIG. 3, the four convex portions 4 a on the rear wall 4 g of the fuel case 4 constituting the partition wall inside the case 3 distribute the fuel in the case 3 from the fuel case 4 side to the heater case 5 side. Each mouth 3p is formed. These four circulation ports 3p are arranged at the upper part of the convex portion 4a, more specifically, at the same height position near the upper end portion of the fuel case 4 and in the left-right direction position aligned with the axis 5X of the corresponding heater case 5. ing. The distribution ports 3p distribute the fuel stored in the fuel case 4 toward the corresponding fuel injection valves 9.

  In the fuel case 4 formed in this way, since only two inflow ports 3i are formed for the four flow ports 3p, the number of processing steps for providing the inflow ports 3i is reduced. Further, in the fuel case 4, the distances from the left inlet 3i to the two left circulation ports 3p and the distances from the right inlet 3i to the two right circulation ports 3p are all equal. The fuel that has evenly flowed from the two inlets 3i flows evenly to the four circulation ports 3p. Furthermore, each flow path from the left inflow port 3i to the two left flow ports 3p and each flow path from the right inflow port 3i to the two right flow ports 3p are all in shape and cross-sectional area in each cross section. Also by being equal, it is ensured that fuel flows evenly through the four circulation ports 3p.

  The fuel case 4 extends substantially horizontally, and the cross-sectional area of the tubular portion 4b on both ends where the inflow port 3i is formed is set larger than the cross-sectional area of the central tubular portion 4c where the inflow port 3i is not formed. As a result, the fuel that has flowed in from each inflow port 3i is difficult to flow to other than the adjacent circulation port 3p. 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 3i is difficult to flow to other than the adjacent circulation port 3p. . Therefore, most of the fuel flowing in from one inflow port 3i flows into the two circulation ports 3p arranged close to each other, and the uniformity of the fuel flowing from the inflow port 3i to each of the circulation ports 3p is maintained. That is, the two circulation ports 3p arranged close to each other so as to sandwich one inflow port 3i have substantially the entire amount of fuel during normal driving in which each fuel injection valve 9 injects an equal amount of fuel to the inflow port 3i. 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 provided with a flow port 3p that is the same as that formed on the rear wall 4g of the fuel case 4 and a flow outlet 3o through which fuel flows out toward the fuel injection valve 9. 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 3 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 flow port 3p of the heater case 5 is disposed in the vicinity of the upper end of the cylindrical side wall 5s that defines the side portion of the heating chamber 8, and the outlet 3o of the heater case 5 is in the vicinity of the lower end of the side wall 5s. 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. Accordingly, the flow port 3p and the outlet 3o are arranged on opposite sides of the heat generating portion 7h, and the flow path axis at the flow port 3p is offset above the flow path axis at the flow outlet 3o. 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. The cold fuel flowing into the heating chamber 8 from the circulation port 3p moves horizontally in the heating chamber 8 and then moves downward, so that convection that recirculates 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 circulation port 3p side by convection. Then, the bubbles gathered on the side of the circulation port 3p are cooled by the cold fuel flowing from the circulation port 3p and liquefy again. Even if the liquid passes through the circulation port 3p and rises without being liquefied, the bubbles remain 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 air bubbles accumulated in the upper part of the heating chamber 8 are cooled by the cold fuel flowing in from the circulation port 3p and liquefy again. Therefore, fuel emptying by the heater 6 is prevented. In addition, since the outlet 3o is disposed in the heater case 5 in the vicinity of the lower portion on the side opposite to the circulation port 3p where the bubbles gather, the bubbles are less likely to flow out from the outlet 3o toward the fuel injection valve 9. Can be driven stably.

  Thus, the fuel in the heater case 5 is heated by the heater member 7, but this heat is transmitted to the fuel or the case 3, whereby the fuel in the fuel case 4 is connected to the heater case 5 on the side of the circulation port 3 p. The warmed fuel rises and accumulates in the upper part of the fuel case 4. And since each inflow port 3i is arrange | positioned in a position lower than each distribution port 3p, as shown in FIG. 4, the fuel supplied by the distribution pipe 2c pushes the fuel in the fuel case 4 upward, and is warm. The fuel is guided to the circulation port 3p side as indicated by a broken line. Therefore, even if the fuel flowing into the fuel case 4 from the inlet 3i is cold, the fuel in the fuel case 4 flows out from the flow port 3p 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 rate of increase in the temperature of the supplied fuel with respect to the output of the heater 6 is prevented from decreasing, and the supplied fuel temperature is all injected. The valve 6 can be heated above the target temperature.

  Further, in the fuel case 4, each inflow port 3 i is disposed in the vicinity of the lower end portion 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 3 i. The fuel is prevented from staying in the fuel case 4 because the fuel is pushed up to the flow port 3p.

  On the other hand, as described above, since the horizontally disposed fuel case 4 has the four convex portions 4a corresponding to the heater 6, as shown in FIG. Even when the case 4 is inclined, the warm fuel remains on the convex portion 4a as shown by the broken line, and the warm fuel is supplied also to the fuel injection valve 9 on the lower side. The injection valves 6 can be kept equal, and the engine drive is prevented from becoming unstable.

  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 heater case 5 and the heater 6 are provided for each fuel injection valve 9, and the flow port 3 p as a flow port is formed in the partition wall portion between the fuel case 4 and the heater case 5. One heater is provided for the plurality of fuel injection valves 9, and the case 3 is such that the fuel case 4 and the heater case 5 are integrated, that is, there is no partition inside, and the circulation port is circulated. The fuel may be supplied directly to the fuel injection valve 9. In addition to these changes, the specific configuration of each member, such as the number and arrangement of the inlets and outlets, 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 3 Case 3i Inflow port 3p Flow port 3o Outlet 4 Fuel case 4a Convex part 5 Heater case 6 Heater 8 Heating chamber 9 Fuel injection valve

Claims (3)

A case for storing fuel and having a heater for heating the fuel;
A plurality of fuel injection valves for injecting fuel flowing out of the case,
The case extends substantially horizontally and has a plurality of convex portions protruding upward at a position corresponding to the fuel injection valve, and fuel is directed toward the fuel injection valve in each of the plurality of convex portions. A fuel supply device, characterized in that a distribution port for distribution is formed.   The fuel supply device according to claim 1, wherein the case is provided with an inflow port through which fuel flows, and the inflow port is disposed at a position lower than the flow port.   The fuel supply device according to claim 2, wherein the inflow port is disposed in the vicinity of a lower end portion of the case.

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