JPS63138153A - Fuel-injection type v-engine - Google Patents

Abstract

PURPOSE:To easily remove a unit injector, by constituting an engine block of a pair of cylinder block units, integrally having a cylinder part and a cylinder head part, and a crankcase fixed by a bolt to the cylinder block unit. CONSTITUTION:A block of a multi cylinder Diesel V-engine is constituted of two cylinder block units 3 and each one of upper and bottom part crankcases 4, 5. A bottom end surface 3a, placed at a right angle with the cylinder center line (q) of each unit 3 respectively forming a bank 2, is fixed by a bolt to the upper end surface of the upper part crankcase 4. While the upper part crankcase 4 is fixed in its bottom end surface 4a to the bottom part crankcase 5 by a bolt, and an oil pan 6 is secured to the bottom end surface of the bottom part crankcase. And each unit 3, formed by a cast article of single construction integrally having a cylinder part 7 and a cylinder head part 8, provides a unit injector 20 to be mounted to a part in the vicinity of the cylinder center line (q) of the cylinder head part 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a V-type engine such as a diesel engine, and particularly to an engine equipped with a unit injector as a fuel injection device.

(Prior art) Generally, the engine block of a V-type diesel engine is
It consists of a crankcase, a pair of cylinder blocks, and a cylinder head fixed to the upper end of each cylinder block.

(Problems to be Solved by the Invention) However, when using a unit injector (a unit structure of a fuel injection pump and a fuel injection valve) or an overhead force shaft type intake/exhaust valve mechanism in an engine with the above structure, disassembly and assembly becomes difficult. Significantly decreased. In particular, when a unit injector is removed for inspection and maintenance, a complex operation comparable to disassembling the entire engine is required.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a pair of cylinder block units forming a V-shaped bank, and an upper crankcase to which both cylinder block units are fixed with bolts. and a lower crankcase that is fixed with bolts to the opposite side of the cylinder block unit of the upper crankcase, and each cylinder block unit has a cylinder part and a cylinder head part integrally formed, and both cylinder block units are connected to each other. They are installed in opposite positions with respect to the center plane of the engine between them, and the unit injector is installed in the cylinder head.

(Embodiment) Fig. 1 is a vertical cross-sectional view of an engine adopting an embodiment of the present invention, Fig. 2 is an enlarged partial view of Fig. 1, and Fig. 3 is a
-■ sectional view, FIG. 4 is a partial view taken along the arrows ■-■ in FIG.

As shown in FIGS. 1 and 3, the engine shown is a 75 degree V-type six-cylinder diesel engine, and when installed on a mounting base (not shown) on the bottom of the ship, the centerline of the crankshaft 1 is approximately It extends horizontally and in the longitudinal direction of the hull.R in Fig. 1 is the vertical engine center plane that includes the crankshaft centerline r.q is the centerline of each cylinder, and Q is the centerline of the three cylinders q. This is the center plane of each bank 2 (a row of cylinder parts and cylinder head parts arranged in series).The left and right bank center planes Q are located symmetrically with respect to the engine center plane R.

In Figure 1, the engine block is basically 2
It is composed of two cylinder block units 3, one upper crankcase 4, and one lower crankcase 5. Each cylinder block unit 3 forms a bank 2, and a lower end surface 3a perpendicular to the cylinder centerline q is fixed to the upper end surface of the upper crankcase 4 with bolts.

The upper crankcase 4 is fixed to the lower crankcase 5 at the lower end surface 4a with bolts. An oil pan 6 is fixed to the lower end surface of the lower crankcase 5. The hypothetical extension surface of the lower end surface 4a includes the crankshaft center line r, and extends perpendicularly to the engine center plane R.

Each cylinder block unit 3 is a single-structure cast product that integrally includes a cylinder portion 7 (a portion surrounding the outer periphery of the piston 9) and a cylinder head portion 8 (a portion facing the top surface of the piston 9). Both cylinder block units 3 have basically the same dimensions and shape, and are attached to the upper crankcase 4 in left and right opposite positions. That is,
Both cylinder block units 3 are aligned with the crankshaft center line r
They are located symmetrically with respect to the engine center plane R, except that they are slightly offset in a direction parallel to the engine.

Therefore, the intake/exhaust device and the fuel injection device provided in the cylinder block unit 3 are also arranged on the engine center plane R as shown below.
The left and right sides are reversed, with .

In each cylinder, the intake port 11 (only the left side in FIG. 1 is shown) is connected from the combustion chamber 10 to the outer side surface of the cylinder head 8 (
The intake manifold 12 extends to the side surface opposite to the engine center plane R, and communicates with the intake manifold 12 attached to the side surface.

The exhaust port 15 extends from the combustion chamber 10 toward the inner side surface of the cylinder head portion 8, and is connected to an exhaust manifold 17 via an exhaust pipe 16 provided on the side surface.

One exhaust manifold 17 is provided in each bank 2, and is located diagonally above the cylinder head portion 8, that is, between both banks 2.2.

A unit injector 20 is attached to a portion of each cylinder head portion 8 near the cylinder center line q. The unit injector 20 is located inside (
The injector is fixed to a hole in the cylinder head 8 (on the side near the engine center plane R), and the injector center line p is inclined away from the cylinder center line q as it goes upward.

Although not clearly shown, unit injector 2
Reference numeral 0 has a conventionally well-known structure, and is a unit structure combining a fuel injection pump and a fuel injection valve, with the upper half of the fuel injection pump protruding above the cylinder head 8. An end of the plunger mechanism of the fuel injection pump projects upward from the upper half, and the projecting end is driven by one end of the rocker arm 21. rocker arm 2
1 is driven by a cam 24 on a camshaft 23 at the other end. In addition to the cam 24 described above, the camshaft 23 is also provided with a cam 25 (FIG. 3) for driving intake and exhaust valves.

The camshaft 23 is parallel to the crankshaft 1 and supported by a head cover 26 fixed to the upper end of the cylinder block unit 3, and a pulley 27 is attached to one end protruding from the head cover 26.

As shown in FIG. 1, the above-mentioned cam mechanism is also provided in a left-right reverse positional relationship with respect to the engine center plane R.

A common timing belt 28 is passed between the left and right pulleys 27. The timing belt 28 is a toothed belt whose toothed surface engages the camshaft pulley 27 and the drive pulley 29 fixed to the crankshaft 1 . 1st
A tension pulley 28a is provided near the bottom of the bank 2 on the left side in the figure. The tension pulley 28a engages with the back surface of the timing belt 28 (the surface opposite to the teeth).

Furthermore, timing belt 28 also engages a driven pulley 31 of governor 30. Governor 30 has both banks 2.2
A governor shaft (not shown) to which a pulley 31 is attached extends parallel to the crankshaft 1. The timing belt 28 passes under the pulley 31, and its back surface engages with the pulley 31. Also pulley 3
1 is located below both camshaft pulleys 27.

Therefore, the timing belt 28 is generally V-shaped between both pulleys 27.

A lever mechanism 35, which is an output part of the governor 30, is connected to the unit injector 20 via a control shaft 33 and a link mechanism 34 as described below.

In FIG. 2, a lever mechanism 35 of the governor 30 is configured to operate in conjunction with a governor weight (not shown), and has an end connected to a lever 36 fixed to the shaft 33. The shaft 33 extends in the width direction of the engine in an attitude slightly inclined with respect to the horizontal direction, and is rotatably supported by a bracket. Both ends 33 of the shaft 33
One end portion of a lever 40 having a bending structure and which is a part of the link mechanism 34 is fixed to a and 33b, respectively. The levers 40 project from the shaft 33 in their radial direction and in mutually opposite directions. In the illustrated embodiment, the second
The lever 40 on the left side in the figure protrudes downward from the end 33a,
The lever 40 on the right side projects upward from the end portion 33b.

The tip of each lever 40 is connected to a pin 42. The pin 42 is provided on the rod 43. The rod 43 connects the vicinity of the inside of the unit injector 20 to the crankshaft 1 (Fig. 1).
The cylinder block unit 3 extends parallel to the cylinder block unit 3, and is supported by a hole provided in the upper wall surface of the cylinder block unit 3 so as to be slidable in the longitudinal direction. A total of three blocks 44 are bolted to each rod 43 at a position adjacent to the unit injector 20 . The block 44 is provided with a pin 45 that projects upward, and the pin 45 engages with a lever 46 of the unit injector 20.

The lever 46 protrudes from the body of the unit injector 20 toward the engine center plane R, and by rotating the lever 46 about the unit injector center line p, the fuel injection amount is adjusted.

The unit injectors 20 on both the left and right sides have the same specifications, and are installed in opposite positions. In addition, each of the above-mentioned parts (40
, 42, 43, 44, and 45) are also used with the same specifications.

According to the above structure, when the governor 30 rotates the shaft 33, both levers 40 also rotate in the same direction, so that the rods 43 on both sides slide in the longitudinal direction and in opposite directions (forward and backward). , the levers 46 also move in opposite directions. Since both unit injectors 20 have the same specifications and are installed in opposite left and right positions, when the levers 46 move as described above, all the levers 46 move in the same direction (increase in injection amount) around the injector center line p. direction or decrease direction). As a result, the fuel injection amount is increased or decreased in all unit injectors 20, and the operating state of the engine is adjusted to a predetermined state.

Further, when acceleration is applied to various parts of the engine due to shaking of a ship equipped with the illustrated engine or sudden acceleration of a vehicle, both rods 43 may receive inertia force in the same direction (for example, forward). In that case, one rod 43 tries to rotate the lever 46 in the direction of increasing the injection amount, and the other rod 43 tries to rotate the lever 46 in the direction of decreasing the injection amount. Therefore, both inertial forces are balanced and the rod 43 does not move. Therefore, the operating condition of the engine is maintained constant.

Generally, the unit injector 20 includes a second
In addition to the structure having the rotary lever 46 as shown in the figure, the second
As shown in the figure, some have a rack 47 that moves linearly. When using such a unit injector 20, the rod 43 is used as a rotating shaft, and each rack 4
7 is connected to the rod 43 via a lever 48, and each rod 43 is connected to an end of the shaft 33 via, for example, a gear mechanism 49. As the gear mechanism 49, a structure is adopted in which both rods 43 are rotated in mutually opposite directions, and as a specific example, a worm gear mechanism is adopted,
The worm attached to one end of the shaft 33 is connected to the rod 4.
The worm wheel on the shaft 33 is engaged from above, and the worm attached to the other end of the shaft 33 is engaged with the worm wheel on the other rod 4.
3. Engage with the upper worm wheel from below. or,
A bevel gear mechanism may be employed as the gear mechanism 49.

Next, the structure of the crankcase will be explained. As shown in Figure 1,
The upper crankcase 4 extends along the crankshaft 1.
21 of the pair of side walls 50, the front and rear end walls 51 shown in FIG. 3, and both side walls 50! It is provided with two partition walls 52 that connect the i locations. A bearing boss that supports the upper half of the crankshaft 1 is formed on the end wall 51 and the partition wall 52.

Similar to the upper crankcase 4, the lower crankcase 5 includes a pair of side walls 55, front and rear end walls 56, and two partition walls 5.
7 is provided. They are respectively connected to the side wall 50
, the end wall 51, and the lower surface of the partition wall 52. Both end walls 56 are formed with bearing bosses that support the ends of the crankshaft 1 from below, and each partition wall 57 is integrally formed with a metal cap portion that supports the intermediate portion of the crankshaft 1 from below. be.

Furthermore, the lower crankcase 5 is provided with a bottom wall 58.

The bottom wall 58 is formed integrally with each of the above-mentioned wall portions (55, 56, 57). As shown in FIG. 1, the bottom wall 58 is provided along the turning trajectory of the large end 61 of the connecting rod 60 and the crank web 62 (FIG. 3). 63 is an opening provided between the metal cap portion of the partition wall 57 and the bottom wall 58. As is clear from the above description, the lower crankcase 5 has a ladder frame structure with a bottom wall and has sufficiently high rigidity.

As shown in FIG. 3, an opening 64 is provided in a portion of the bottom wall 58 on the side away from the flywheel 65, and a crank chamber 66
communicates with the inside of the oil pan 6 via an opening 64. Therefore, the lubricating oil that has flowed into the crank chamber 66 is
or through the openings 63 and 64 into the oil pan 6.

An oil suction pipe 67 is provided inside a portion of the oil pan 6 on the flywheel 65 side. The suction vibrator 67 communicates with the suction port of the oil pump 69 via an internal passage in the end wall 56,51 on the flywheel 65 side. The oil pump 69 is a gear pump having a pair of gears 70.71 and is provided inside a case 72 bolted to the outer surface of the end wall 51.56. A discharge passage 73 of the oil pump 69 is formed inside the case 72, and communicates with an oil gear rally 74 formed inside the left side wall 50 in FIG.

The gear 70 is directly fixed to the outer periphery of the crankshaft 1. The other gear 71 has its support shaft supported by the pump case 75. Case 75 is disposed inside case 72 and bolted to the inner surface of case 72.

Pulley 2 for driving the aforementioned timing belt 28
9 is attached to the end of the crankshaft 1 opposite to the flywheel 65. A pulley 76 is attached to the end of the crankshaft 1 protruding from the pulley 29. Pulley 76
is connected to a pulley 78 above it via a belt 77. The pulley 78 is attached to the input shaft of the fresh water pump 79.

A case 80 of the fresh water pump 79 is bolted to the outer surface of the upper part of the front end wall 51 of the upper crankcase 4 and the lower part of the front end wall of the cylinder block unit 3.

An inlet (not shown) of the fresh water pump 79 is connected to a fresh water cooler (not shown) installed diagonally above the fresh water pump 79 via a pipe (not shown). Fresh water pump 7
The discharge passage 84 of No. 9 is formed by a wall portion 85 that projects integrally from the case 80 and is connected to a cooling water jacket 86 inside the cylinder block unit 3 .

The cooling water jacket 86 is provided inside the cylinder portion 7 and cylinder head portion 8 . The internal cavity of the cylinder block unit 3 forming the cooling water jacket 86 is designated by the reference numeral 7.
As shown by a s 7 b, 8 a, and 8 b, both front and rear end surfaces of the cylinder portion 7 and cylinder head portion 8 are open to the outside. In the state shown by the solid line in FIG. 3, the discharge passage 84 communicates with the lower a between the front ends of the cylinder part 7,
The other open lower portions b, 8as and 8b are closed by a cover plate 87 fixed to the outer surface of the cylinder block unit 3.

The opening 8a of the cylinder head 8 can also be used as a cooling water inlet. In that case, a case 80 having a wall portion 85 extending to the opening 8a is used, and the open lower door a is closed with a cover plate. When the opening 8a is used as a cooling water inlet in this way, if the cylinder part 7 is easily cooled (when the cooling water temperature is very low, such as when seawater is used as cooling water), the temperature will be higher than that of the cylinder part 7. Since low-temperature cooling water can be supplied to the cylinder head section 8, which tends to suffer from heat, the temperatures of the cylinder section 7 and the cylinder head section 8 can be made uniform, and the entire engine can be effectively cooled.

Further, the lower cylinders b and 8b are used as cooling water inlets when the cylinder unit is installed in a forward and backward movement position.

When seawater is used as cooling water, a seawater pump 89 is provided on the side of the cylinder block unit 3 as shown in FIG. 1, and is driven by a belt by a boob attached to the end of the camshaft 23.

In FIG. 4, the above-mentioned cooling water is supplied into the exhaust manifold 17 after cooling the cylinder head. A cooling water outlet of the exhaust manifold 17 communicates with an internal passage of a cooling water pipe 93 arranged above. The outlet of the cooling water pipe 93 is connected to the thermostat case 91. The thermostat case 91 is provided with a cooling water outlet vibe 94.
is connected to the fresh water cooler 8 via a pipe (not shown) or hose.
Connected to 2.

As is clear from FIG. 4, the governor 30 is provided at the end of the engine. A support plate 95 is bolted to the end face of the cylinder block unit 3 in the vicinity of the governor 30, and an end of the governor 30 is bolted to the support plate 95.

Next, an example in which the above-mentioned engine is used in a ship will be briefly described.

In the embodiment shown in FIG. 5, the engine is used in an inboard/outboard motor. The engine is installed inside the hull T with the crankshaft centerline r being approximately horizontal. The flywheel 65 is located at the rear end of the engine and is connected to the outdrive unit M via a connecting shaft m. In this structure, the starter 96, oil filter 97, oil cooler 98, and generator 99 are arranged on the side of the crankcase. Further, a turbocharger 90 is installed at the rear of the upper end of the engine.

In the embodiment of FIG. 6, the engine is used as an outboard motor. The crankshaft centerline r extends substantially vertically.

Turbocharger 90 is located at the upper rear end of the engine. Auxiliary equipment and some parts are installed in different positions from those shown in Figure 5. For example, the flywheel 65 is attached to the upper end of the engine, and the starter 96 is located at the upper front of the engine body. Also seawater pump 89
is incorporated inside the lower unit N, and is driven by a drive shaft n inside the unit N. Furthermore, the oil pan 6 shown in FIG. 3 is eliminated, the opening 64 is closed with a suitable member, and lubricating oil is directly sucked into the oil pump 69 from inside the crank chamber 66.

(Effects of the Invention) As explained above, according to the present invention, since the cylinder block unit 3 having the cylinder part 7 and the cylinder head part 8 integrated is adopted, the fourteenth structure for fixing the cylinder head to the cylinder block with the head bolt is used. Compared to this, the removal work of the unit injector 20 can be easily performed.

Furthermore, if the cylinder block unit 3 is adopted, it is necessary to insert the piston 9 into the cylinder part 7 from the crank chamber 66 side when assembling the engine, but since the cylinder block unit 3 and the upper crankcase 4 are separate blocks, both Piston 9 can be installed before fixing. Therefore, the work of assembling the piston 9 is also easy.

If the cylinder block unit 3 and the upper crankcase 4 were to be formed integrally, the end wall 5 would be required to prevent the piston 9 from interfering with the partition wall 52 etc. when the piston is assembled.
1 and the partition wall 52, as well as the axial length between the adjacent partition walls 52 and 52, it is necessary to set a large length. However, in the present invention, since the cylinder block unit 3 and the upper crankcase 4 are separate blocks, there is no need to set the above-mentioned axial length to be large, and therefore the axial length of the entire engine block can be shortened.

Furthermore, casting is easier than in the case of integrally casting the crankcase, cylinder block, and cylinder head.

Further, as in the illustrated embodiment, the left and right cylinder block units 3 are installed in reverse order, and the structures of both cylinder block units 3 are basically the same, so that the manufacturing cost of the cylinder block units 3 can be reduced.

Furthermore, since the upper crankcase 4 is provided with a wide hole or opening into which the skirt portion of the piston 9 enters, if the upper crankcase 4 is formed from a single block as in the present invention, its strength will be relatively low. However, in the structure of the embodiment, since the lower crankcase 5 has a ladder frame structure with a bottom wall 58, the rigidity of the entire crankcase, that is, the entire engine block can be sufficiently increased.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of an engine employing an embodiment of the present invention, FIG. 2 is an enlarged partial view of FIG. 1, and FIG. 2A is a schematic diagram of another embodiment of the coupling mechanism between the unit injector and the governor. , Fig. 3 is a sectional view taken along the line m--■ in Fig. 1, Fig. 4 is a partial view taken along the line IV-IV in Fig. 3, and Fig. 5 is a side view of the engine shown in Fig. 1 when used in an inboard/outboard motor. FIG. 6 is a schematic side view of the engine shown in FIG. 1 used in an inboard engine. 2・
...Bank, 3...Cylinder block unit, 4.
... Upper crankcase, 5... Lower crankcase, 7... Cylinder part, 8... Cylinder head part, 2
0...Unit injector, R...Engine center surface Patent applicant: Yanmar Diesel Co., Ltd. Agent Patent attorney: Tadataka Omori, −′■, 2゜

Claims (3)

[Claims] (1) A pair of cylinder block units forming a V-shaped bank, an upper crankcase to which both cylinder block units are fixed with bolts, and a cylinder block unit fixed to the opposite side of the upper crankcase with bolts. A lower crankcase is provided, a cylinder part and a cylinder head part are integrally formed in each cylinder block unit, and both cylinder block units are installed in opposite positions with respect to the center plane of the engine between them. A fuel-injected V-type engine featuring a unit injector. (2) Install the unit injectors of one bank and the unit injectors of the other bank in opposite positions with respect to the center plane of the engine, and connect each unit injector to the output section of a common governor via a connection mechanism. , the fuel injection type according to claim 1, wherein the coupling mechanism coupled to the unit injector of one bank and the coupling mechanism coupled to the unit injector of the other bank are set to operate in opposite directions. V-type engine. (3) The lower crankcase includes a pair of side walls extending along the crankshaft, a pair of end walls connecting both ends of both side walls, a partition wall connecting the middle part of both side walls, and covering the crank chamber from below. Claim 1 or 2, wherein the metal cap portion for the crankshaft is provided integrally with the bottom wall, and the partition wall is provided with a metal cap portion for the crankshaft.
The fuel-injected V-type engine described in .