JPS6032327Y2 - Engine oil pump mounting structure - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of an engine oil pump mounting mechanism.

Conventionally, an oil pump 31 that pumps engine oil to various sliding parts has been installed in a crankcase 3 as shown in FIG.
In most cases, the pump 31 and its drive mechanism are installed on the outer surface of the case wall below the bearing part of the crankshaft 33 of No. 2 and are linked to the crankshaft 33 through gears 34 and 35, and the pump 31 and its drive mechanism are all located outside the case. Therefore, the length of the engine in the longitudinal direction (in the direction of the crankshaft axis) increases.

Although not shown, it is also conceivable that the pump 31 is mounted on a mounting seat provided in line with the mounting surface of the oil pan 36 formed at the lower end of the crankcase 32, and only the pump drive mechanism is disposed outside the case. However, in this case, the height of the engine would have increased.

This idea was developed in light of these problems, and by fixing the oil pump in a space created by cutting out the lower wall of the crankshaft bearing of the crankcase, The purpose of this invention is to shorten the longitudinal length and height of the engine to make it more compact, and to provide a pump mounting mechanism that allows the pump to be properly assembled easily.

Examples of this invention will be described below based on the drawings.

Fig. 1 shows a longitudinal front view of a two-cylinder water-cooled horizontally opposed diesel engine, Fig. 2 shows its cross-sectional plane, and Fig. 3 shows a longitudinal side view of the cylinder block 1, which is long from side to side.
Cylinder heads 2, 2 are attached to both the left and right ends of the cylinder block 1, and a fuel tank unit 3 and a cell starter 4 are arranged in the upper part of the cylinder block 1 in a left-right distribution. and a fuel filter 6 are attached.

The cylinder block 1 is formed by integrally casting a crankcase 1a in which a crankshaft 7 is inserted and supported through the front and rear side wall portions, and a pair of horizontally opposing cylinders lb, lb, which are formed on the bottom wall of the crankcase 1a. The opening 8 for assembly and maintenance is covered by the oil pan 5.

A timing belt case 26 is disposed on the front surface of the crankcase 1a, and the crankshaft 7 is inserted and supported in the front and rear side walls of the timing belt case 26, so that the crankshaft 7 is positioned within the timing belt case 26. A timing belt 19, 19' is wound around this part via a pulley.

In the front wall portion of the crankcase 1a, below the crankshaft bearing portion 9, an oil pump installation space 10 is formed which is cut into a substantially rectangular shape and opened downward, as shown in FIG. .

A pump mounting seat 12 is formed on the upper surface of this space 10 to receive the upper surface of an oil pump 11 incorporated from below.
A positioning fitting surface 13.13 that tightly fits is formed on the upper left and right end surfaces of the pump 11, and the pump 11 positioned on this fitting surface 13.13 is attached to the downward mounting seat 12 of the case wall portion with two bolts 14. It is configured to be fixed.

The drive shaft 15 of the oil pump 11 protrudes from the crankcase 1a toward the timing belt case 26 side, and is connected to a pair of gears 16.
．． It is interlocked and connected to the crankshaft 7 via 17.

Among the pair of gears 16 and 17, the pump driving gear 17
is formed into a cap shape with an outer peripheral part and a central part connected by an inclined surface, and is fixed to the pump drive shaft 15 with the outer peripheral part close to the crankshaft bearing part 9.

Moreover, the upper part of the pump 11 is viewed from the direction of the crankshaft axis,
The inner cover 11a of the pump 11 has a shape in which a portion interfering with the trajectory P has been cut out, and the inner cover 11a of the pump 11 has a shape in which a portion interfering with the trajectory P is cut out.

The inside of the timing belt case 26 and the inside of the crankcase 1a are partitioned by a side wall 26a of the timing belt case 26 on the crankcase side.Moreover, the side wall 26a of the timing belt case 26 on the crankcase 1a side is used to drive the pump. A portion facing the pump drive gear 17 is formed along the front side of the pump drive gear 17.

Reference numeral 18 in the figure indicates a camshaft for opening and closing the valves installed in the left and right cylinder heads 2, which are synchronized and interlocked by the crankshaft 7 and timing belts 19 and 19', respectively.

Further, 20 is a fuel injection pump assembled to the pump unit 3, 21 is a camshaft for driving the pump, 22 is a governor, and the camshaft 21 is wound around and interlocked with one of the timing belts 9.

Further, 23 is an oil suction pipe through which the engine oil stored in the oil pan 5 is sucked into the pump 11 through the strainer 24, and 25 is a discharge pipe.

As explained above, this invention accommodates the oil pump in the space formed by cutting out a part of the lower wall of the crankshaft bearing of the crankcase, and the wall surrounding this space. Because it is fixed with a fixture, the front and rear length of the engine is shorter compared to an engine in which the oil pump and its drive mechanism are all located outside the crankcase wall. The engine height is lower than in models where the oil pump is mounted on the pan mounting surface, making it possible to mount the oil pump with a more compact structure overall.

Furthermore, since the pump drive gear fixed to the oil pump drive shaft is formed into a shade shape and the outer periphery of the gear is located on the crankcase side, there is no place on the oil pump drive shaft to fix the pump drive gear. No matter how far away it is from the crankcase, the outer periphery of the pump drive gear can be positioned close to the crankcase, so the pump drive gear and its counterpart gear can be fixed close to the crankcase. I can do it.

For this reason, the length of the oil pump drive shaft in the axial direction of the crankshaft must be increased by the distance from the point where the pump drive gear is fixed to the crankcase.Compared to a flat pump drive gear, the crankshaft Since the length in the axial direction of the engine can be shortened, the front and rear length of the engine can be shortened, and the oil pump can be installed with an overall compact structure.

Moreover, in order to prevent the gaseous lubricating oil in the crankcase from entering the timing belt case from the cut-out wall portion of the crankcase, a side wall on the crankcase side of the timing belt case is provided, and this side wall is used to prevent the timing belt case from entering the timing belt case. The inside of the case and the inside of the crankcase must be partitioned, but since the part of this side wall that faces the pump drive gear is formed along the front of the pump drive gear, the end of the oil pump drive shaft No matter how far the side wall is from the Krumfkeras due to the interference, the part of the side wall facing the pump drive gear can be located near the pump drive gear.

For this reason, the axial length of the crankshaft must be longer than the distance from the end of the oil pump drive shaft to the crankcase. Since the length can be shortened, the entire engine can be made into a compact structure and an oil pump can be attached.

In particular, when a mounting seat and a positioning fitting surface are formed in the oil pump installation space, the pump installation positioning becomes extremely simple and easy, and it can be linked appropriately with the drive mechanism, making it even more convenient. It will be available for use.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention; Fig. 1 is a longitudinal front view of the engine, Fig. 2 is a longitudinal sectional side view, Fig. 3 is a view taken along arrow A-A in Fig. 2, and Fig. 4 is a view of the conventional structure. It is a longitudinal side view of a main part showing an example. 1a...Crank case, 9...Crankshaft bearing part, 10...Oil pump installation space, 11...Oil pump, 12...・Mounting seat, 13...Positioning mating surface, 14...
··Fixture.

Claims (1)

[Scope of claim for utility model registration] 1. Timing belt case 26 on the front of crankcase 1a.
A part of the wall located below the crankshaft bearing part 9 of the crankcase 1a is cut out to form an oil pump installation space 10, and an oil pump 11 is housed in this oil pump installation space 10. , the oil pump 11 is fixed to the crankcase wall portion around the oil pump installation space 10 with a fixture 14, the drive shaft 15 of the oil pump 11 is made to protrude from the crankcase 1a toward the timing belt case 26 side, and the oil pump The pump drive gear 17 fixed to the drive shaft 15 is formed into a shade shape with the outer circumference located on the crankcase 9 side, and is opposed to the pump drive gear 17 on the crankcase side side wall 26a of the timing belt case 26. The timing belt case 26 is formed along the front side of the pump driving gear 17, and the crankcase side side wall 26a of the timing belt case 26 partitions the inside of the timing belt case 26 and the inside of the crankcase 1a. Engine oil pump mounting mechanism. 2 Utility Model Registration Scope of Claims 3. In the engine oil pump mounting structure described in claim 1, the lower surface of the oil pump installation space 10 is open, and the oil pump 11 can be installed into this installation space 10 from below. 3 Utility Model Registration In the oil pump mounting structure for an engine according to claim 1 or 2, a pump mounting seat 12 and a positioning fitting surface are provided on the inner peripheral surface around the oil pump installation space 10 in the crankcase wall portion. 13, and the oil pump 11 is fixed to the pump mounting seat 12 with a fixture 14 with the oil pump 11 positioned by the positioning fitting surface 13.