engine

Abstract

To provide a technique, for an engine mounted with two cylinder rows, capable of preventing the cylinder rows from delivering different combustion performance while curbing an increase in a cost.SOLUTION: An engine comprises: a first cylinder row which has a plurality of cylinders arranged in a longitudinal direction; a second cylinder row which is arranged parallel to the first cylinder row; a plurality of first injectors which is installed for respective cylinders of the first cylinder row; a plurality of second injectors which is installed for respective cylinders of the second cylinder row; and a fuel pump which has a first discharge port discharging fuel to the plurality of first injectors and a second discharge port discharging fuel to the plurality of second injectors. In a planar view from above or below, the fuel pump is arranged between the first cylinder row and the second cylinder row.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an engine. [Background technology]

[0002] Conventionally, there is known a V-type engine in which two delivery tubes extending from a high-pressure fuel pump are provided between the banks, and each delivery tube sequentially connects the injectors of each bank to distribute fuel (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-349385 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the V-type engine disclosed in Patent Document 1, the high-pressure fuel pump is disposed on the rear side of one of the banks (rearward of the bank). In such a configuration, since the high-pressure fuel pump is disposed biased toward the end of one of the banks, there is a concern that a difference in the length of the fuel pipe that supplies fuel from the high-pressure fuel pump to the injector between the two banks will occur. If a difference in the length of the fuel pipe occurs, fuel pulsation will cause a difference in the fuel injection amount and fuel injection pressure, and there is a possibility that a difference in combustion performance will occur between the banks. In order to avoid this, it is possible to make the length of the fuel pipe between the two banks equal, but in this case, it is necessary to match the length to the fuel pipe with the longer length, and there is a possibility that the fuel injection pressure will decrease due to an increase in flow path resistance caused by the extension of the flow path, resulting in a deterioration of engine performance, and there is a concern that it will be uneconomical in terms of cost.

[0005] An object of the present invention is to provide a technique for suppressing a difference in combustion performance between the cylinder rows in an engine having two cylinder rows, while suppressing an increase in cost. [Means for solving the problem]

[0006] An exemplary engine of the present invention includes a first cylinder row having a plurality of cylinders aligned in a front-rear direction, a second cylinder row aligned parallel to the first cylinder row, a plurality of first injectors provided for each of the cylinders in the first cylinder row, a plurality of second injectors provided for each of the cylinders in the second cylinder row, and a fuel pump having a first outlet port for discharging fuel to the first injectors and a second outlet port for discharging fuel to the second injectors. The fuel pump is disposed between the first cylinder row and the second cylinder row in a top-bottom plan view. Effect of the Invention

[0007] According to the exemplary embodiment of the present invention, in an engine having two cylinder rows, it is possible to suppress the occurrence of a difference in combustion performance between the cylinder rows while suppressing an increase in cost. According to the exemplary embodiment of the present invention, it is possible to suppress the occurrence of a difference in combustion performance between the cylinder rows, and to suppress a deterioration in engine performance. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view showing the configuration of an engine. [Diagram 2] FIG. 2 is a schematic perspective view showing a portion of the engine that is composed of a cylinder block, a head block, and a head cover. [Diagram 3] Schematic cross-sectional view of a cylinder block portion of an engine. [Figure 4] Schematic top view showing the engine configuration [Diagram 5] FIG. 2 is a schematic perspective view showing a fuel system of the engine; [Figure 6] A diagram showing the fuel pump and injector-related parts of the engine's fuel system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the following description, the X direction is the front-rear direction, the Y direction is the left-right direction, and the Z direction is the up-down direction. The +X side is the front side, and the -X side is the rear side. The +Y side is the right side, and the -Y side is the left side. The +Z side is the upper side, and the -Z side is the lower side. In detail, the direction in which the center line C of the crankshaft (output shaft) shown in FIG. 1 extends is the front-rear direction, and the side where the flywheel 2 is arranged with respect to the cylinder block 1 is the rear side. In addition, the up-down direction is defined as the side where the oil pan 3 is arranged with respect to the cylinder block 1 is the lower side. The direction perpendicular to the front-rear direction and the up-down direction is defined as the left-right direction, and the side that is the right side when viewed from the rear toward the front is the right side, and the side that is the left side is the left side. Note that these directions are names used simply for explanation, and are not intended to limit the actual positional relationship and direction.

[0010] <1. Engine Overview> Fig. 1 is a schematic perspective view showing a configuration of an engine 100 according to an embodiment of the present invention. The engine 100 is suitable as a marine engine for use in ships, for example. However, the engine 100 is not limited to being a marine engine and may be applied to other applications. The engine 100 is a diesel engine.

[0011] As shown in Fig. 1, engine 100 includes a cylinder block 1, a head block 4, and a head cover 5. Fig. 2 is a schematic perspective view showing a portion of engine 100 that includes cylinder block 1, head block 4, and head cover 5. Fig. 3 is a schematic cross-sectional view of the cylinder block 1 portion of engine 100.

[0012] As shown in Figures 2 and 3, a crankshaft 6 and a piston 7 extending in the front-rear direction are disposed inside the cylinder block 1. The inside of the cylinder block 1 is connected to the inside of an oil pan 3 disposed below and storing lubricating oil. A flywheel 2 (see Figure 1) is attached to the rear end of the crankshaft 6. The flywheel 2 rotates integrally with the crankshaft 6 and is used to extract power from the engine 100. More specifically, the piston 7 is disposed in a cylinder 11 formed in the cylinder block 1. The piston 7 is connected to the crankshaft 6 via a connecting rod 71.

[0013] In detail, the cylinder block 1 has a right cylinder 11R arranged on the right side and a left cylinder 11L arranged on the left side. The right cylinder 11R is cylindrical inclined to the right side with respect to the vertical direction and extends in an oblique direction when viewed from the rear. The left cylinder 11L is cylindrical inclined to the left side with respect to the vertical direction and extends in an oblique direction when viewed from the rear. The right cylinder 11R and the left cylinder 11L are arranged in a V-shape. The pair of right cylinder 11R and left cylinder 11L arranged in a V-shape are arranged with the cylinder axes slightly shifted in the front-rear direction. In this embodiment, the left cylinder 11L is arranged slightly forward of the right cylinder 11R.

[0014] The cylinder block 1 has two cylinder rows 111. In detail, the cylinder block 1 has a right cylinder row 111R in which a plurality of right cylinders 11R are arranged in the front-rear direction, and a left cylinder row 111L in which a plurality of left cylinders 11L are arranged in the front-rear direction. The right cylinder row 111R and the left cylinder row 111L have the same number of cylinders 11. That is, the engine 100 has a first cylinder row 111R having a plurality of cylinders 11R arranged in the front-rear direction. The engine 100 has a second cylinder row 111L arranged in parallel with the first cylinder row 111R. The second cylinder row 111L is arranged in the left-right direction with the first cylinder row 111R, and has the same number of cylinders 11L arranged in the front-rear direction as the first cylinder row 111R. The right cylinder row 111R and the left cylinder row 111L form a V-shaped bank. In this embodiment, for example, the number of right cylinders 11R constituting the right cylinder row 111R and the number of left cylinders 11L constituting the left cylinder row 111L are both 6. That is, the engine 100 of this embodiment is a V-type 12-cylinder engine.

[0015] In each of the right cylinder row 111R and the left cylinder row 111L, a head block 4 is disposed overlapping each cylinder 11. The head block 4 is fastened to the cylinder block 1 using a screw. In detail, the head block 4 includes a right head block 4R overlapping the right cylinder 11R and a left head block 4L overlapping the left cylinder 11L. The right head blocks 4R are overlapped one by one on each of the right cylinders 11R, so that there are as many right cylinders 11R as there are right cylinders 11R. The left head blocks 4L are overlapped one by one on each of the left cylinders 11L, so that there are as many left cylinders 11L as there are left cylinders 11L. In this embodiment, the number of right head blocks 4R and left head blocks 4L is six.

[0016] Each head block 4 has an intake port 41 for supplying gas to a combustion chamber formed by the cylinder 11, piston 7, and head block 4, and an exhaust port (not shown) for exhausting gas from the combustion chamber. The exhaust port is provided on the surface opposite to the surface on which the intake port 41 is provided. In detail, the right head block 4R has an intake port 41 on its left side surface and an exhaust port on its right side surface. The left head block 4L has an intake port 41 on its right side surface and an exhaust port on its left side surface.

[0017] A head cover 5 is placed on top of each head block 4. The head cover 5 is fastened to the head block 4 with screws. Each head cover 5 covers an intake valve and an exhaust valve (not shown) arranged on the head block 4. An injector 8 is attached to each head cover 5. One end of the injector 8, which is provided with an injection port for injecting fuel, faces the combustion chamber. The other end of the injector 8 protrudes from the head cover 5 towards the outside.

[0018] In detail, the head cover 5 includes a right head cover 5R that is placed on the right head block 4R and a left head cover 5L that is placed on the left head block 4L. The right head covers 5R are placed on each right head block 4R, so there are the same number of right head covers 5R as the number of right head blocks 4R. The left head covers 5L are placed on each left head block 4L, so there are the same number of left head blocks 4L. In this embodiment, the number of right head covers 5R and left head covers 5L is six. The number of right injectors 8R arranged on the right head cover 5R and the number of left injectors 8L arranged on the left head cover 5L are also six.

[0019] As can be seen from the above, the engine 100 includes a plurality of first injectors (right injectors) 8R provided for each cylinder (right cylinder) 11R of the first cylinder row (right cylinder row) 111R, and a second injector (left injector) 8L provided for each cylinder (left cylinder) 11L of the second cylinder row (left cylinder row) 111L. The engine 100 includes a plurality of first injectors 8R and a plurality of second injectors 8L, and the number of the first injectors 8R is the same as the number of the second injectors 8L. The first injector 8R and the second injector 8L are the same. Note that, although the first injector 8R and the second injector 8L are the same in this embodiment, they may be different.

[0020] On the right side of the cylinder block 1, the right cylinder 11R, the right head block 4R, and the right head cover 5R that constitute the right bank RB extend obliquely upward to the right. On the left side of the cylinder block 1, the left cylinder 11L, the left head block 4L, and the left head cover 5L that constitute the left bank LB extend obliquely upward to the left. In a plan view from the front-rear direction, the right bank RB and the left bank LB are V-shaped, and the engine 100 has a V-bank. An intra-bank area 200 is formed between the right bank RB and the left bank LB in the left-right direction.

[0021] Returning to FIG. 1, the engine 100 includes a top cover 9 and a side cover 10. The top cover 9 prevents water from splashing on the controller 26 (see FIG. 4, etc., described later) and other components disposed inside the engine 10 due to, for example, condensation. The side cover 10 prevents fuel from scattering due to, for example, cracks in components such as the head block 4. Although FIG. 1 only shows the side cover 10 disposed on the right side, a similar side cover 10 is also disposed on the left side. That is, the engine 100 includes a pair of left and right side covers 10.

[0022] Fig. 4 is a schematic top view showing the configuration of an engine 100 according to an embodiment of the present invention. The top cover 9 and the pair of side covers 10 are omitted in Fig. 4. As shown in Figs. 1 and 4, the engine 100 includes an intake manifold 21 and an exhaust manifold 22.

[0023] The intake manifold 21 distributes intake air, which is air or a mixture drawn in from the outside, to each cylinder 11. The intake manifold 21 is disposed on the upper part of the engine 100 and extends in the front-rear direction. In detail, the intake manifold 21 includes a right intake manifold 21R for the right cylinder 11R and a left intake manifold 21L for the left cylinder 11L.

[0024] The right intake manifold 21R is disposed above the intake ports 41 (see FIG. 2) of the multiple right head blocks 4R aligned in the front-rear direction. The interior of the right intake manifold 21R is connected to each of the right cylinders 11R via each of the intake ports 41. The left intake manifold 21L is disposed above the intake ports 41 of the multiple left head blocks 4L aligned in the front-rear direction. The interior of the left intake manifold 21L is connected to each of the left cylinders 11L via each of the intake ports 41.

[0025] In more detail, an intake valve (not shown) is interposed between each intake port 41 and each cylinder 11, and when the intake valve is opened, the inside of the intake manifold 21 and the cylinder 11 communicate with each other.

[0026] The exhaust manifold 22 collects exhaust from each cylinder 11. The exhaust manifold 22 is disposed on a side portion of the engine 100 and extends in the front-rear direction. In detail, the exhaust manifold 22 includes a right exhaust manifold 22R for the right cylinder 11R and a left exhaust manifold 22L for the left cylinder 11L.

[0027] The right exhaust manifold 22R is disposed on the right side of multiple right head blocks 4R (see FIG. 2) arranged in the front-rear direction. The interior of the right exhaust manifold 22R and each right cylinder 11R are connected via exhaust ports (not shown) provided on the right side of the right head block 4R. The left exhaust manifold 22L is disposed on the left side of multiple left head blocks 4L (see FIG. 2) arranged in the front-rear direction. The interior of the left exhaust manifold 22L and each left cylinder 11L are connected via exhaust ports (not shown) provided on the left side of the left head block 4L.

[0028] In more detail, an exhaust valve (not shown) is interposed between each exhaust port and each cylinder 11, and when the exhaust valve is opened, the inside of the exhaust manifold 22 and the cylinder 11 communicate with each other.

[0029] The exhaust gas collected in the right exhaust manifold 22R is exhausted to the outside via a right supercharger 23R and a right exhaust outlet pipe 24R arranged at the right rear of the engine 100. The exhaust gas collected in the left exhaust manifold 22L is exhausted to the outside via a left supercharger 23L and a left exhaust outlet pipe 24L arranged at the left rear of the engine 100.

[0030] The right turbocharger 23R and the left turbocharger 23L each have a compressor section 231 and a turbine section 232. The compressor section 231 pressurizes and compresses intake air such as air supplied from outside the engine 100. The pressurized and compressed intake air is supplied to the intake manifold 21 via the intercooler 25. The turbine section 232 is rotated by exhaust gas supplied from the exhaust manifold 22. The rotational power of the turbine section 232 is transmitted to the compressor section 231. That is, the right turbocharger 23R and the left turbocharger 23L of this embodiment are so-called turbochargers that use an exhaust gas turbine as a drive source.

[0031] The intercooler 25 connected to the intake manifold 21 is supplied with cooling water by a cooling water pump (not shown) and cools the intake air. The intake air supplied from the compressor unit 231 is pressurized and compressed, generating compression heat and increasing the temperature. The intercooler 25 cools the intake air by exchanging heat between the cooling water supplied from the cooling water pump and the pressurized and compressed intake air. In other words, by providing the intercooler 25, the temperature of the intake air supplied to the intake manifold 21 can be adjusted to a desired temperature.

[0032] As shown in Fig. 4, the right intake manifold 21R and the left intake manifold 21L are arranged at a distance from each other in the left-right direction on the upper part of the engine 100. As shown in Fig. 4, when the top cover 9 is removed, the in-bank area 200 is exposed to the outside through the space between the right intake manifold 21R and the left intake manifold 21L. In the in-bank area 200, for example, a controller 26 that controls the entire engine 100 and the like are arranged.

[0033] That is, the engine 100 includes a controller 26 disposed in an intra-bank area 200 located between the first cylinder row 111R and the second cylinder row 111L. In the strict sense, the intra-bank area 200 may be the spatial area between the first cylinder row 111R and the second cylinder row 111L. However, in this embodiment, the intra-bank area 200 broadly includes the spatial area in the left-right direction between the right bank RB including the first cylinder row 111R and the left bank LB including the second cylinder row 111L.

[0034] By arranging the controller 26 in the in-bank area 200, the in-bank area 200 can be efficiently used for arranging parts, thereby making it possible to reduce the size of the engine 100. However, the controller 26 may be arranged outside the in-bank area 200.

[0035] In addition, the controller 26 specifically includes a first controller 261 and a second controller 262. However, the number of controllers 26 may be changed as appropriate, and for example, the controller 26 may be configured with only one controller. In this embodiment, the first controller 261 and the second controller 262 are arranged in the front-rear direction. In detail, the first controller 261 is located forward of the second controller 262. One of the first controller 261 and the second controller 262 is a main controller, and the other is a sub-controller. In this embodiment, the first controller 261 is the main controller, and the second controller 262 is the sub-controller.

[0036] The first controller 261 configured as a main controller executes calculations necessary for controlling the engine 100. The calculations necessary for controlling the engine 100 include, for example, calculations related to control of fuel injection and calculations related to stopping the engine 100. The second controller 262 configured as a sub-controller is connected to the first controller 261 by a communication line (not shown) and is provided so as to be able to communicate with the first controller 261. The second controller 262 performs control operations according to instructions from the first controller 261.

[0037] The first controller 261 controls the right injector 8R arranged in the right bank RB. That is, the first controller 261 and each right injector 8R are electrically connected. The second controller 262 controls the left injector 8L arranged in the left bank LB. That is, the second controller 262 and each left injector 8L are electrically connected.

[0038] <2.Fuel system> As shown in Fig. 4, engine 100 includes a fuel pump 27. Fuel pump 27 supplies fuel to injector 8. A fuel system including fuel pump 27 will be described in detail below. Fig. 5 is a schematic perspective view showing a fuel system FS provided in engine 100. Note that in Fig. 5, fuel stored in a fuel tank (not shown) is supplied to engine 100 from a fuel inlet portion 28. Also, a portion of the fuel is returned from engine 100 to the fuel tank through a fuel outlet portion 29.

[0039] 5, in addition to the above-mentioned injectors 8 and fuel pump 27, the fuel system FS includes an auxiliary pump 31, a fuel filter 32, a low-pressure fuel supply pipe 33, a high-pressure fuel supply pipe 34, and a fuel return pipe 35. As described above, the injectors 8 include six right injectors 8R and six left injectors 8L. The fuel pump 27 is driven by utilizing the rotational power of the crankshaft 6. The auxiliary pump 31 assists in the pumping of fuel when the engine 100 is started. More specifically, the fuel pump 27 includes a low-pressure fuel pump 271 and a high-pressure fuel pump 272.

[0040] The low-pressure fuel supply pipe 33 includes a first low-pressure fuel supply pipe 331, a second low-pressure fuel supply pipe 332, and a third low-pressure fuel supply pipe 333. The first low-pressure fuel supply pipe 331 connects the fuel inlet portion 28 and the low-pressure fuel pump 271 via the auxiliary pump 31. The second low-pressure fuel supply pipe 332 connects the low-pressure fuel pump 271 and the fuel filter 32. The third low-pressure fuel supply pipe 333 connects the fuel filter 32 and the high-pressure fuel pump 272.

[0041] In this embodiment, the fuel filter 32 includes two fuel filters arranged in parallel, but this is merely an example. The number of fuel filters may be changed as appropriate, and may be one, three or more. Also, a configuration in which multiple fuel filters are connected in series may be used.

[0042] The high-pressure fuel supply pipe 34 includes a right high-pressure fuel supply pipe 34R and a left high-pressure fuel supply pipe 34L. The right high-pressure fuel supply pipe 34R is a fuel pipe for the right bank RB, and connects the high-pressure fuel pump 272 to a plurality of right injectors 8R (six in this embodiment). The left high-pressure fuel supply pipe 34L is a fuel pipe for the left bank LB, and connects the high-pressure fuel pump 272 to a plurality of left injectors 8L (six in this embodiment). It is preferable that the right high-pressure fuel supply pipe 34R and the left high-pressure fuel supply pipe 34L have the same length. This can suppress a difference in injection timing between the right injector 8R and the left injector 8L.

[0043] The fuel return pipe 35 includes a first fuel return pipe 351, a second fuel return pipe 352, and a third fuel return pipe 353. The first fuel return pipe 351 connects the high-pressure fuel pump 272 and the fuel outlet portion 29. The second fuel return pipe 352 is a fuel pipe for the right bank RB, and is connected to each right head block 4R constituting the right bank RB. The second fuel return pipe 352 is connected to a junction portion 351a provided in the middle of the first fuel return pipe 351. At the junction portion 351a, the fuel flowing through the second fuel return pipe 352 merges with the fuel flowing through the first fuel return pipe 351. The third fuel return pipe 353 is a fuel pipe for the left bank LB, and is connected to each left head block 4L constituting the left bank LB. The third fuel return pipe 353 is connected to a junction portion 351a provided in the middle of the first fuel return pipe 351. At the junction 351a, the fuel flowing through the third fuel return pipe 353 joins with the fuel flowing through the first fuel return pipe 351.

[0044] The fuel supplied to the fuel inlet 28 passes through the first low-pressure fuel supply pipe 331 and enters the low-pressure fuel pump 271 in response to the operation of the low-pressure fuel pump 271, is pressurized, and then is sent to the fuel filter 32 through the second low-pressure fuel supply pipe 332. The fuel sent to the fuel filter 32 has dust and dirt removed by the fuel filter 32. The fuel from which dust and the like have been removed is sent to the high-pressure fuel pump 272 through the third low-pressure fuel supply pipe 333.

[0045] The high-pressure fuel pump 272, which has received the fuel, pressurizes the fuel and discharges it toward the right high-pressure fuel supply pipe 34R and the left high-pressure fuel supply pipe 34L. The fuel passing through the right high-pressure fuel supply pipe 34R is distributed to each right injector 8R arranged in the right bank RB. The fuel passing through the left high-pressure fuel supply pipe 34L is distributed to each left injector 8L arranged in the left bank LB. Each injector 8 injects fuel into the combustion chamber at a predetermined timing.

[0046] The high-pressure fuel pump 272 returns surplus fuel to the fuel tank via the first fuel return pipe 351. Also, surplus fuel not used for combustion flows from each right head block 4R to the second fuel return pipe 352. Also, surplus fuel not used for combustion flows from each left head block 4L to the third fuel return pipe 353. The fuel flowing to the second fuel return pipe 352 and the third fuel return pipe 353 merges with the fuel in the first fuel return pipe 351 at the junction 351a, and is returned to the fuel tank.

[0047] Fig. 6 is a diagram showing an extracted portion of the fuel system FS of the engine 100 that is related to the fuel pump 272 and the injector 8. In Fig. 6, the dashed line frame typically shows an area in which the left and right cylinder rows 111 are arranged. As shown in Fig. 6, the fuel pump 27 has a first outlet port 2721 and a second outlet port 2722. In detail, the high-pressure fuel pump 272 has the first outlet port 2721 and the second outlet port 2722. The high-pressure fuel pump 272 has two fuel outlet ports.

[0048] The first outlet port 2721 discharges fuel to the multiple first injectors. The second outlet port 2722 discharges fuel to the multiple second injectors. In detail, the first outlet port 2721 discharges fuel to the six right injectors 8R. The second outlet port 2722 discharges fuel to the six left injectors 8L.

[0049] The fuel discharged from the first discharge port 2721 to the first injectors arranged in the front-rear direction is supplied in order from the first injector located at one end in the front-rear direction to the first injector located at the other end in the front-rear direction in the order in which they are arranged in the front-rear direction. In this embodiment, the fuel discharged from the first discharge port 2721 to the six right injectors 8R arranged in the front-rear direction is supplied in order from the right injector 8R located at the rear end to the right injector 8R located at the front end in the order in which they are arranged in the front-rear direction.

[0050] In FIG. 6, the fuel discharged from the first discharge port 2721 flows through the first right injector 8R1, the second right injector 8R2, the third right injector 8R3, the fourth right injector 8R4, the fifth right injector 8R5, and the sixth right injector 8R6 in this order. The first right injector 8R1 is the right injector 8R located at the rear end. The second right injector 8R2 is the right injector 8R located immediately before the first right injector 8R1. The third right injector 8R3 is the right injector 8R located immediately before the second right injector 8R2. The fourth right injector 8R4 is the right injector 8R located immediately before the third right injector 8R3. The fifth right injector 8R5 is the right injector 8R located immediately before the fourth right injector 8R4. The sixth right injector 8R6 is the right injector 8R located immediately before the fifth right injector 8R5.

[0051] Furthermore, the fuel discharged from the second outlet 2722 to the second injectors arranged in the front-rear direction is supplied in order from the second injector located at one end in the front-rear direction to the second injector located at the other end in the front-rear direction in the order in which they are arranged in the front-rear direction. In this embodiment, the fuel discharged from the second outlet 2722 to the six left injectors 8L arranged in the front-rear direction is supplied in order from the left injector 8L located at the rear end to the left injector 8L located at the front end in the order in which they are arranged in the front-rear direction.

[0052] In FIG. 6, the fuel discharged from the second discharge port 2722 flows in the order of the first left injector 8L1, the second left injector 8L2, the third left injector 8L3, the fourth left injector 8L4, the fifth left injector 8L5, and the sixth left injector 8L6. The first left injector 8L1 is the left injector 8L located at the rear end. The second left injector 8L2 is the left injector 8L located immediately before the first left injector 8L1. The third left injector 8L3 is the left injector 8L located immediately before the second left injector 8L2. The fourth left injector 8L4 is the left injector 8L located immediately before the third left injector 8L3. The fifth left injector 8L5 is the left injector 8L located immediately before the fourth left injector 8L4. The sixth left injector 8L6 is the left injector 8L located immediately before the fifth left injector 8L5.

[0053] The configuration is not limited to this embodiment, and the high-pressure fuel pumped from the high-pressure fuel pump 272 may be stored in a common rail, and the high-pressure fuel in the common rail may be distributed to each injector.

[0054] As shown in FIG. 6, the fuel pump 27 is disposed between the first cylinder row (right cylinder row) 111R and the second cylinder row (left cylinder row) 111L in a plan view from the top-bottom direction. The space between the first cylinder row 111R and the second cylinder row 111L may be read as the space between the right bank RB and the left bank LB. With this configuration, the first discharge port 2721 and the second discharge port 2722 can be disposed in the center of the two cylinder rows 111R and 111L (the two banks RB and LB) in the left-right direction. As a result, the lengths of the two high-pressure fuel supply pipes 34R and 34L that supply fuel from the fuel pump 27 to the injectors 8 of the cylinder rows 111R and 111L can be made the same while preventing them from becoming longer than necessary.

[0055] In this embodiment, the fuel pump 27 having the first outlet 2721 and the second outlet 2722 includes the low-pressure fuel pump 271 and the high-pressure fuel pump 272, but this is merely an example. The fuel pump having the first outlet and the second outlet may be a single high-pressure fuel pump.

[0056] In this embodiment, the first outlet port 2721 and the second outlet port 2722 are disposed between the right cylinder row 111R and the left cylinder row 111L in the left-right direction in a top-bottom plan view. In particular, the first outlet port 2721 and the second outlet port 2722 are disposed in the center between the right cylinder row 111R and the left cylinder row 111L in the left-right direction in a top-bottom plan view. Note that the center may include not only a position that is exactly in the center, but also a position that is slightly shifted from the center.

[0057] In this embodiment, the first outlet 2721 and the second outlet 2722 are disposed near one end in the front-rear direction of the V bank formed by the right bank RB and the left bank LB. In detail, the first outlet 2721 and the second outlet 2722 are disposed near the rear end in the front-rear direction of the V bank. With such an arrangement, the first outlet 2721 can be disposed near the first right injector 8R1 to which fuel is supplied first in the right bank RB, and the second outlet 2722 can be disposed near the first left injector 8L1 to which fuel is supplied first in the left bank LB. As a result, the length of the high-pressure fuel supply pipe 34 can be prevented from becoming longer than necessary.

[0058] As shown in Fig. 6, the high-pressure fuel supply pipe 34 is composed of a connection pipe 341 and multiple inter-injector pipes 342. The connection pipe 341 includes a right connection pipe 341R and a left connection pipe 341L. The inter-injector pipes 342 include a right inter-injector pipe 342R and a left inter-injector pipe 342L. The right high-pressure fuel supply pipe 34R is composed of the right connection pipe 341R and multiple right inter-injector pipes 342R. The left high-pressure fuel supply pipe 34L is composed of the left connection pipe 341L and multiple left inter-injector pipes 342L.

[0059] In detail, the right connection pipe 341R connects the first discharge port 2721 and the first right injector 8R1 so that fuel can be supplied therebetween. The first right injector 8R1 is the right injector 8R to which fuel is first supplied from the first discharge port 2721. The left connection pipe 341L connects the second discharge port 2722 and the first left injector 8L1 so that fuel can be supplied therebetween. The first left injector 8L1 is the left injector 8L to which fuel is first supplied from the second discharge port 2722.

[0060] The right and left connection pipes 341R and 341L have the same length. In other words, the first connection pipe 341R that connects the first discharge port 2721 and the multiple first injectors 8R so as to be able to supply fuel, and the second connection pipe 341L that connects the second discharge port 2722 and the multiple second injectors 8L so as to be able to supply fuel, have the same length.

[0061] If the right and left connecting pipes 341R and 341L are made to have the same length, the difference in pressure fluctuation between the right and left cylinder rows 111R and 111L can be reduced. That is, the difference in fuel injection pressure and fuel injection timing between the right and left cylinder rows 111R and 111L can be suppressed. As a result, the difference in combustion performance between the right and left cylinder rows 111R and 111L can be suppressed. The right and left connecting pipes 341R and 341L having the same length may include not only the case where the two are completely the same, but also the case where the lengths are almost the same. The difference in length within a range where there is no difference in combustion performance between the two may be included in the case where the lengths are almost the same.

[0062] In this embodiment, the first outlet port 2721 and the second outlet port 2722 are aligned in the front-rear direction. In a configuration in which the first outlet port 2721 and the second outlet port 2722 are aligned in the front-rear direction, both the first outlet port 2721 and the second outlet port 2722 can be disposed in the center of the right cylinder row 111R and the left cylinder row 111L.

[0063] The first outlet port 2721 is disposed on one side in the front-rear direction of the second outlet port 2722. The first injector 8R to which fuel is first supplied from the first outlet port 2721 is disposed on one side in the front-rear direction of the second injector 8L to which fuel is first supplied from the second outlet port 2722.

[0064] In detail, the first discharge port 2721 is disposed rearward of the second discharge port 2722. The first right injector 8R1 to which fuel is first supplied from the first discharge port 2721 is disposed rearward of the first left injector 8L1 to which fuel is first supplied from the second discharge port 2722 (see dashed line DL in FIG. 6). With this configuration, when the lengths of the right connection pipe 341R and the left connection pipe 341L are made uniform, it is possible to prevent both pipes from becoming longer than necessary.

[0065] The right injector inter-pipe 342R connects two right injectors 8R adjacent to each other in the front-rear direction. In detail, the first right injector 8R1 and the second right injector 8R2 are connected by the right injector inter-pipe 342R. The second right injector 8R2 and the third right injector 8R3 are connected by the right injector inter-pipe 342R. The third right injector 8R3 and the fourth right injector 8R4 are connected by the right injector inter-pipe 342R. The fourth right injector 8R4 and the fifth right injector 8R5 are connected by the right injector inter-pipe 342R. The fifth right injector 8R5 and the sixth right injector 8R6 are connected by the right injector inter-pipe 342R.

[0066] As can be seen from the above, the engine 100 includes an injector pipe 342R that connects the multiple first injectors 8R together so that fuel can be supplied between them. In particular, the engine 100 includes a plurality of injector pipes 342R that connect two first injectors 8R adjacent to each other in the front-rear direction so that fuel can be supplied between them. It is preferable that at least two of the multiple injector pipes 342R have the same shape. Note that the multiple injector pipes 342R referred to here specifically refer to the five right injector pipes 342R.

[0067] In this embodiment, the five right injector pipes 342R all have the same shape. By making the multiple right injector pipes 342R have the same shape, it is possible to standardize parts. As a result, it is possible to reduce the manufacturing costs and management costs of parts. Specifically, the shape of the five right injector pipes 342R is S-shaped.

[0068] In this embodiment, the left bank LB has the same configuration as the right bank RB with respect to the configuration of the injector pipe 342. That is, the left injector pipe 342L connects two left injectors 8L adjacent to each other in the front-rear direction. In detail, the first left injector 8L1 and the second left injector 8L2 are connected by the left injector pipe 342L. The second left injector 8L2 and the third left injector 8L3 are connected by the left injector pipe 342L. The third left injector 8L3 and the fourth left injector 8L4 are connected by the left injector pipe 342L. The fourth left injector 8L4 and the fifth left injector 8L5 are connected by the left injector pipe 342L. The fifth left injector 8L5 and the sixth left injector 8L6 are connected by the left injector pipe 342L.

[0069] As can be seen from the above, the engine 100 includes five left inter-injector pipes 342L that connect two second injectors 8L adjacent to each other in the front-rear direction so that fuel can be supplied between them. In this embodiment, the five left inter-injector pipes 342L all have the same shape. More specifically, the five left inter-injector pipes 342L are S-shaped. It is not necessary for all of the multiple left inter-injector pipes 342L to have the same shape. However, it is preferable that at least two of them have the same shape.

[0070] In addition, in this embodiment, the right injector pipe 342R and the left injector pipe 342L have the same shape. That is, the right injector pipe 342R and the left injector pipe 342L are used as a common part. With this configuration, the total length of the five right injector pipes 342R and the total length of the five left injector pipes 342L can be easily made the same. That is, the length of the right high pressure fuel supply pipe 34R and the length of the left high pressure fuel supply pipe 34L can be easily made the same.

[0071] The shape of the injector pipe 342 may be a shape other than an S-shape. It is preferable that the shape of the injector pipe 342 has a bent portion so as to absorb manufacturing errors. The shape of the injector pipe 342 may be a shape other than an S-shape, such as a J-shape or a U-shape.

[0072] <3. Things to keep in mind> Various technical features disclosed in this specification can be modified in various ways without departing from the spirit of the technical creation. In other words, the above embodiment should be considered to be illustrative in all respects and not restrictive. In addition, multiple embodiments and modifications shown in this specification may be combined to the extent possible.

[0073] In the embodiment described above, the engine 100 is a V-type engine, but this is merely an example. The present invention is also applicable to, for example, a horizontally opposed engine in which a piston reciprocates horizontally. [Explanation of symbols]

[0074] 8. Injector 8R Right injector (first injector) 8L···Left injector (second injector) 11. Cylinder 11R: Right cylinder 11L···Left cylinder 27 Fuel pump 100···Engine 111... cylinder row 111R: Right cylinder row (first cylinder row) 111L... Left cylinder row (second cylinder row) 341... Connecting pipe 341R Right connecting pipe (First connecting pipe) 341L···Left connecting pipe (Second connecting pipe) 342 Injector pipe 342R Right injector pipe 342L Pipe between left injectors 2721...1st discharge port 2722...Second discharge port

Claims

1. a first cylinder row having a plurality of cylinders aligned in a front-rear direction; a second row of cylinders aligned parallel to the first row of cylinders; a plurality of first injectors provided for each of the cylinders in the first cylinder row; a plurality of second injectors provided for each of the cylinders in the second cylinder row; a fuel pump having a first outlet port that discharges fuel to the first injectors and a second outlet port that discharges fuel to the second injectors; Equipped with the fuel pump is disposed between the first cylinder row and the second cylinder row in a plan view from a vertical direction, the fuel discharged from the first discharge port to the first injectors arranged in the front-rear direction is supplied in order from the first injector located at one end in the front-rear direction to the first injector located at the other end in the front-rear direction in the order in which the first injectors are arranged in the front-rear direction; an engine, in which fuel discharged from the second discharge port to a plurality of second injectors arranged in a front-to-rear direction is supplied in order from the second injector located at one end in the front-to-rear direction to the second injector located at the other end in accordance with the order in which the second injectors are arranged in the front-to-rear direction.

2. An engine as described in claim 1, wherein the length of a pipe connecting from the first outlet to the first injector located at the other end is the same as the length of a pipe connecting from the second outlet to the second injector located at the other end.

3. 3. The engine according to claim 1, wherein a first connection pipe connecting the first discharge port and the plurality of first injectors so as to enable fuel supply, and a second connection pipe connecting the second discharge port and the plurality of second injectors so as to enable fuel supply, have the same length.

4. an injector-to-injector pipe connecting the plurality of first injectors to each other so as to be able to supply fuel thereto; 4. The engine according to claim 1, wherein at least two of the plurality of inter-injector pipes have the same shape.

5. The engine according to claim 1 , wherein the first discharge port and the second discharge port are aligned in a front-rear direction.

6. The first discharge port is disposed on one side of the second discharge port in a front-rear direction, 6. The engine according to claim 1, wherein the first injector to which fuel is first supplied from the first discharge port is disposed on one side in a front-to-rear direction of the second injector to which fuel is first supplied from the second discharge port.

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