JPS633405Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fuel injection pump mounting mechanism for an in-line multi-cylinder engine, mainly a diesel engine.
In a conventional engine, the fuel injection pump case 1 was cast integrally with the crankcase 2, as shown in FIG. However, in order to cast the fuel injection pump case 1 and the crankcase 2 as a single unit in this way, a complex-shaped mold and a core for the fuel injection pump case 1 are required. Since the fuel injection pump case 1 has to be formed by the following steps, the yield of the casting deteriorates and an increase in manufacturing costs cannot be avoided. In addition, in order to avoid the injection pump 4 from interfering with the intake manifold 8 extending from the cylinder head 3, the upper wall of the fuel injection pump case must be
The upper wall 1a of the fuel injection pump case must be formed at an angle so that the end opposite to the cylinder head 3 (the left end in Fig. 3) is lower. Case 2
When casting the fuel injection pump case 1 integrally with the fuel injection pump case 1, it is difficult to form the fuel injection pump case 1 into the shape shown in FIG. 3 without increasing the manufacturing cost, for example, because (the casting direction) is not aligned. Moreover, the following problems also occurred during the machining process after casting. That is, generally when adjusting the injection timing of the fuel injection pump 4, a shim or the like is inserted between the flange portion 6a of the support base 6 of the fuel injection pump 4 and the upper wall 1a of the fuel injection pump case to adjust the base circle of the camshaft 7. Dimension l from to the bottom surface of the flange portion 6a
However, in order to be able to accurately adjust the injection timing, after casting the fuel injection pump case 1, the upper surface of the fuel injection pump case upper wall 1a is machined into a flat shape. It is necessary to keep it. However, the fuel injection pump case upper wall 1
Since a is inclined with respect to a horizontal plane (more precisely, a plane perpendicular to the cylinder center line O), it is extremely difficult to precisely machine the upper surface of the upper wall 1a of the fuel injection pump case.

The present invention aims to eliminate the above-mentioned conventional drawbacks, and will be described below with reference to the drawings.

FIG. 1 is a schematic plan view of a diesel engine, and in this FIG. 1, 11 is a crankcase (hidden by a cylinder head 15),
1a is a gear case fixed to the front wall of the crankcase 11; 12 is a fuel injection pump case mounting flange formed in an overhanging manner on the front wall of the crankcase 11; the flange 12 is integrated with the crankcase 11; It is cast and the crankshaft 1
It is formed in a plane perpendicular to 3. Disposed within the gear case 11a are a crank gear 14 fixed to the crankshaft 13, an idle gear 23 that meshes with the crank gear 14, a fuel injection pump drive gear 24 that meshes with the idle gear 23, and the like. 24 is fixed to the camshaft 22 for operating the fuel injection pump. Further, a governor mechanism 27 is attached to the inner end of the gear case 11a of the camshaft 22. A cylinder head 15 is fixed to the upper end of the crankcase 11, and an intake manifold 16 extends from a side wall of the cylinder head 15 (left side wall in FIG. 1). Numeral 17 is a fuel injection pump case separate from the crankcase 11, and this fuel injection pump case 17 is attached to the rear surface of the flange 12 as follows.

That is, in FIG. 2, which is an enlarged cross-sectional view of FIG. A fuel injection pump 20 is attached to the injection pump case 17 from above. Therefore, not only is the entire fuel injection pump 20 disposed away from the cylinder head 15, but also the upper end of the fuel injection pump 20 is mounted in an inclined position so as to move further away from the cylinder head 15. It turns out. The fuel injection pump 20 is connected to the injection nozzle via a high-pressure fuel pipe 21.

The camshaft 22 is supported by a bearing 26 fitted into the flange 12 and a bearing fitted into the rear wall of the fuel injection pump case 17. 28 is a governor link insertion hole formed in the flange 12.

As explained above, according to the present invention: (1) A fuel injection pump case mounting flange 1 is attached to the gear case mounting side end (so-called front end) of the crankcase 11 at right angles to the crankshaft 13.
2, and the fuel injection pump case 17, which is separate from the crankcase 11, is fixed to this flange 12, which not only saves time and effort in casting the crankcase 11, but also allows the fuel injection pump case to be attached to the flange 12. 17 can be easily tilted so that its upper end portion is away from the cylinder head 15. Therefore, manufacturing costs can be significantly reduced.

(2) Since the fuel injection pump case 17 is formed separately from the crankcase 11, even if the fuel injection pump case 17 is attached to the flange 12 in an inclined manner, the pump case 17
The crankcase 11 can be machined separately, and therefore the upper surface of the fuel injection pump case upper wall 17a can be easily machined into a flat shape. That is, the machining work of the fuel injection pump case 17 does not require much effort, and the distance l' between the upper surface of the fuel injection pump case upper wall 17a and the base circle of the camshaft 22 can be accurately adjusted to a specified dimension.

(3) Since the fuel injection pump case 17 is formed separately from the crankcase 11, for example, the crankcase 11 is manufactured from a highly rigid FC material, while the fuel injection pump case 17 is manufactured from a lightweight material such as Al casting. This makes it possible to reduce the weight and cost of the engine.

(4) The fuel injection pump case 17 is formed separately from the crankcase 11, and the fuel injection pump case 1
7 is fixed to the flange 12 instead of directly to the crankcase 11, it is possible to prevent heat from being conducted from the cylinder to the fuel injection pump 20, and furthermore, the upper wall 17a of the fuel injection pump case 17 is attached to the cylinder. Since the fuel injection pump case 17 is tilted away from the cylinder head 15, the fuel injection pump 20 naturally also moves away from the cylinder head 15, making it possible to prevent the fuel injection pump 20 from becoming hotter more effectively. can. That is, it is possible to accurately prevent disturbances in the fuel injection characteristics due to an increase in the temperature of the fuel injection pump 20.

(5) Since the fuel injection pump case 17 is tilted so that the fuel injection pump case upper wall 17a moves away from the cylinder head 15, interference between the intake manifold 16 extending from the cylinder head 15 and the fuel injection pump 20 is avoided. It can be easily avoided without increasing costs.

That is, by arranging the fuel injection pump case 17 below the intake manifold 16 that extends laterally from the cylinder head 15 in an inclined manner so that its upper end moves away from the cylinder head 15,
The space below the intake manifold 16 is effectively used as a space for arranging the fuel injection pump.

Therefore, the lower end of the fuel injection pump case 17 can be brought closer to the crankcase 11 side,
While avoiding interference with the intake manifold 16, the width of the engine in the direction perpendicular to the crankshaft 13 can be made compact.

(6) A camshaft 22 for operating the fuel injection pump is made to penetrate through the flange 12 and protrude into the gear case 11a, and a pump drive gear 24 and a governor mechanism 27 are provided on the camshaft portion inside the gear case 11a.
Since the pump drive gear 24 is connected to the crank gear 14 via the idle gear 23 in the gear case 11a, the pump drive gear 24 and the governor mechanism 27 are sufficiently lubricated by the lubricating oil in the gear case 1a, and are also lubricated by the gear case 11a. Easily protected from the outside world.

That is, the pump drive gear 24 and the governor mechanism 27
lubrication can be easily and sufficiently ensured, and it can also be easily protected from the outside.

(7) Since the drive gear 24 for driving the fuel injection pump is connected to the crank gear 14 via the idle gear 23, power transmission is possible in which power is extracted from the camshaft for driving the intake and exhaust valves using a timing belt or the like. The gear type power transmission mechanism of the present invention is compact compared to other mechanisms.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view of an in-line multi-cylinder diesel engine to which the present invention is applied, and Fig. 2 is the same as Fig. 1.
The partially enlarged sectional view, FIG. 3, is a sectional view corresponding to FIG. 2 of the conventional example. 11...Crank case,
11a... Gear case, 12... Injection pump mounting flange, 13... Crankshaft, 15... Cylinder head, 17... Fuel injection pump case.

Claims (1)

[Scope of utility model registration request] A fuel injection pump case mounting flange is integrally formed on the gear case mounting side end of the crankcase and projects perpendicularly to the crankshaft and on the same side as the intake manifold, and the fuel injection pump case is attached to the intake manifold. The camshaft for operating the fuel injection pump is placed on the lower side, tilted so that the upper end of the fuel injection pump case moves away from the cylinder head and does not interfere with the intake manifold, and is fixed to the fuel injection pump mounting flange. protrudes into the gear case through a flange, the pump drive gear and governor mechanism are provided on the camshaft inside the gear case, and the pump drive gear is connected to the crank gear via the idle gear inside the gear case. Features a fuel injection pump mounting structure for in-line multi-cylinder engines.