JPS6234950B2 - - Google Patents

Abstract

PURPOSE:To eliminate need of a particular blind cap by providing an outlet passage in an oil pump body and fixing an intake part at the bottom of the oil pump body so as to close a lower open port of the outlet passage. CONSTITUTION:An oil pump 11, a trochoid pump, which is removalbe to be mounted at the interior corner of an oil pan 4 inside a crankcase 3 has a pump house wherein an outer rotor 15 and an inner rotor 18 are contained. The inner rotor 18 is turned by a driving gear 19 with an aid of a chain 20. An outlet passage 21 extends downwards from the pump house 14 and is connected to an oil passage. An open port 23 opening to the lower face of a pump body 12 is provided on the way of the outlet passage 21. This open port 23 is airtightly closed by securing an intake part 28 to the lower face of the pump body 12. The intake port 28 having an oil suction port 29 is communicated by an intake passage 22 with the pump house 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil pump that pumps oil to each lubricating part of an engine.

For example, the oil pump in a motorcycle engine is often installed at the bottom of the engine's crankcase, that is, inside the oil pan.For ease of maintenance, this oil pump is installed while the engine is mounted on the vehicle body. The structure is such that it can be removed from the engine by simply removing the oil pan without disassembling the whole thing. This oil pump draws oil stored in an oil pan into a pump chamber through a suction port, and pumps the oil from the pump chamber to various parts of the engine through a discharge passage.

By the way, when an oil pump is installed in the oil pan like this, the oil being pumped is sent to each lubricating part of the engine above this pump, so the suction and discharge directions of the oil are almost opposite directions. Therefore, the total height from the suction side to the discharge side increases, and the oil pump as a whole tends to become larger. This is particularly undesirable for engines mounted on motorcycles where the height of the engine must be kept low.

Therefore, in the past, the discharge passage was led out from the pump chamber so as to be directed downward, that is, to the suction side, and then this lead-out end was directed upward again to approximately U
Alternatively, the above-mentioned discharge passage may be formed in a downward direction, and an oil passage may be formed inside the oil pan directly opposite to this outlet opening, and the oil passage may be formed in an upward direction. Efforts have been made to keep the overall height as low as possible.

However, in order to form the discharge passage in a U-shape as described above, there are manufacturing problems such as inserting a mold for casting and a drill for machining, so that the discharge passage must open downward in the middle. An opening must be provided, and therefore a separate blind plug is required to close the opening after molding is completed, resulting in an increase in the number of parts and increased costs. Furthermore, if the oil pan is provided with a special oil passage, there are drawbacks such as the complicated shape of the mold for forming the oil pan.

The present invention was made based on the above circumstances, and its purpose is not only to keep the overall height of the engine low, but also to provide a simple structure that eliminates the need for a separate blind plug and reduces the number of parts. I'm trying to get an oil pump.

The details of the present invention will be explained below based on the drawings in which the present invention is applied to an engine for a two-wheeled motor vehicle.

In the figure, 1 is a frame and 2 is an engine. This engine 2 has a wet sump lubrication system, and is provided with an oil pan 4 at the bottom of a crankcase 3 for storing oil. A crankshaft 5 and a main axle 6 are housed in the crankcase 3.
is provided with a drive gear 7. A driven gear 8 provided coaxially with the main axle 6 meshes with the drive gear 7. Note that numerals 9 and 9 represent a camshaft, and 10 represents a cam chain. An oil pump 11 is removably mounted within the crankcase 3 so as to be present within the oil pan 4. This oil pump 11 is a trochoid pump, and this pump will be explained below. That is, reference numeral 12 denotes an oil pump body, which is removably fixed to the crankcase 3 via bolts 13. Pump chamber 14 provided at one side opening of this oil pump body 12
An outer rotor 15 is rotatably housed in the outer rotor 15, and a drive shaft 16 is inserted through a portion eccentric to the outer rotor 15. This drive shaft 16 is pivotally supported by a cover 17 attached to the pump body 12, and an inner rotor 18 that rotates eccentrically with respect to the outer rotor 15 is coaxially fixed to this drive shaft 16. and,
This drive shaft 16 is rotationally driven by a drive gear 19, and a chain 20 is stretched between the drive gear 19 and the main axle 6.

On the other hand, a discharge passage 21 is led out from the pump chamber 14 so as to be directed downward, that is, toward the oil pan 4 side, and this discharge passage 21 is directed upward again from its leading end to form a substantially U-shape. , and its open end is connected to an oil passage 22 in the crankcase 3. An opening 23 that opens to the lower surface of the pump body 12 is provided in the middle of the discharge passage 21, that is, at the outlet end. This opening 23 is used as an opening for inserting a drill when cutting the pump body 12 from a mold and when machining the inner surface of the discharge passage 21. Furthermore, a relief valve 24 is installed in the middle of the discharge passage 21. This relief valve 24 suppresses the oil discharge pressure, which increases as the rotation speed of the crankshaft 5 increases, within a certain range.When the oil pressure in the discharge passage 21 exceeds a specified value, a spring urges the valve body 25. 26 is compressed and the oil is pumped through the discharge passage 21 through oil escape holes 27, 27 provided on the circumferential surface of the valve body 25.
The oil is then returned to the oil pan 4 via the oil pan 4. A suction port body 28 is attached to the lower surface of the pump body 12. This suction port body 28 has a circular oil suction port 29 on the lower surface, and this oil suction port 29 is below the oil level A in the oil pan 4, that is, immersed in oil, and is connected to the pump body 12. It communicates with the pump chamber 14 via a suction passage 32 provided.
Note that reference numeral 30 is an oil strainer attached to the oil suction port 29. By fixing this suction port body 28, the opening 23 of the pump body 12 is closed in a fluid-tight manner.

Note that, as shown by the broken line in FIG.
The oil is fed under pressure into the oil passage 22 through the oil passageway 22. During this pressure feeding process, the pressure is adjusted to a specified level by the relief valve 24, and then sent to the oil filter 31 where it is filtered again. It is led to the crankshaft 5, main axle 6 and camshafts 9, 9 to cool and lubricate these parts, and then returned to the oil pan 4.

According to such a configuration, the oil pump 11 is composed of the oil pump main body 12 provided with the discharge passage 21 and the suction port body 28 provided with the suction port 29, and by fixing the suction port body 28, the pump Since the opening 23 on the lower surface of the main body 12 is closed, a separate blind stopper for closing the opening 23 can be omitted. Therefore, the number of parts and the process for installing the blind plug can be reduced.
At the same time, since there is no need to provide a special oil passage in the oil pan 4, the shape of the mold does not become complicated, and as a result, costs can be reduced. In addition, since the discharge passage 21 is directed toward the oil pan 4 side, it is possible to prevent the total height from the suction side to the discharge side from increasing, and therefore, especially in a motorcycle engine 2, This is convenient for those who want to keep the overall height of the engine low.

Note that the present invention is not limited to the above embodiments. For example, it goes without saying that the oil pump of the present invention is not limited to use in motorcycle engines, but can be used in other vehicles, such as three-wheeled vehicles, four-wheeled vehicles, or in various fields other than vehicles. stomach.

Further, the oil pump is not limited to the trochoid pump, but may also be implemented as a gear pump, for example.

As described above, the present invention provides an oil pump body with a discharge passage led out from a pump chamber in the pump body so as to be directed downward, and having an opening opening downward in the middle thereof. At the same time, a suction port body with an oil suction port is attached to the lower part of the oil pump body, and the above-mentioned opening is closed by this suction port body. A separate blind stopper can be omitted. Therefore, the number of parts and the process for installing the blind plug can be reduced, and costs can be reduced. Further, since the discharge passage is directed downward, that is, to the suction side, it is possible to prevent the total height from the suction side to the discharge side from increasing, and it is possible to achieve excellent effects such as being able to keep the height of the engine low.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a side view of the engine, FIG. 2 is a sectional view, FIG. 3 is a view taken along the line - in FIG. 2, and FIG. 4 is a view of the engine. Medium-
FIG. 5 is a sectional view taken along the line - in FIG. 4. 2...Engine, 3...Crankcase, 12...Oil pump body, 14...Pump chamber, 21...Discharge passage, 23...Opening, 28...Inlet body, 29...Oil inlet.

Claims (1)

[Claims] 1. An oil pump body is removably attached to the lower part of the crankcase of the engine, and a pump chamber provided in the oil pump body is guided downwardly and communicated with the engine side. A discharge passage with an opening opening downward is provided in the middle of the oil pump body, and a suction body with an oil suction port is attached to the lower part of the oil pump body. An oil pump characterized by a closed opening in the pump body.