JP3136666B2 - Outboard oil pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outboard motor oil pump.

[0002]

2. Description of the Related Art An oil pump for an outboard motor equipped with a four-stroke engine generally uses a trochoid pump having a simple structure and a compact structure. As shown in FIG. 7, the trochoid pump has an outer-toothed inner rotor 2 that rotates integrally with a drive shaft 1 such as a crankshaft, and an inner-toothed outer rotor 3 that meshes with the inner rotor 2 and rotates in the same direction as the inner rotor 2. The suction port 4 and the discharge port 5 adjacent to the lower surfaces of the inner rotor 2 and the outer rotor 3 are respectively connected to the suction hole 6 and the discharge hole 7 communicating with the outside of the pump. The lubricating oil enters the suction port 4, is carried to the discharge port 5 by the engagement of the inner rotor 2 and the outer rotor 3, and is discharged from the discharge hole 7.

[0003] The suction port 4 and the discharge port 5 are
In general, the suction hole 6 and the discharge hole 7 are located on opposite sides of the drive shaft 1 by approximately 180 ° because they are opposed to each other with the drive shaft 1 interposed therebetween.

Further, an inlet 8 and an outlet 9 serving as passages for connecting the suction hole 6 and the discharge hole 7 to the suction port 4 and the discharge port 5, respectively, are formed linearly from outside of the pump case 10 by drilling. The outer ports of the inlet 8 and the outlet 9 are closed by a plug 11 or the like.

Further, when a relief valve for releasing an excess pressure is provided so that the discharge pressure of the oil pump does not exceed a predetermined value, the relief valve is formed integrally with the pump case.

[0006]

However, even in a layout in which the suction hole 6 and the discharge hole 7 are limited to positions approximately 180 ° opposite to each other across the drive shaft 1 as in the trochoid pump described above, the suction hole 6 and an engine-side oil gallery connected to the discharge hole 7 (oil passages connected to each lubricating portion inside the engine).
Cannot be laid out on the opposite side 180 ° from the other side, so that it is often necessary to form a dedicated guide passage connecting the discharge hole 7 and the oil supply passage on the engine side to a member such as an engine or an engine holder. As a result, the structure around the engine became complicated and cost increased.

Further, since the inlet 8 and the outlet 9 formed by drilling can be formed only in a linear shape, the position of the suction hole 6 and the discharge hole 7 is easily limited also in this point, and the above problem is promoted. Is done. In addition, the cost for drilling and closing the plug 11 is high.

Further, since the oil pump is arranged in a narrow place below the engine, it must be miniaturized as much as possible. However, when the relief valve is provided, the pump case becomes large and the discharge from the relief valve is performed at the same time. In order to return the relief oil to be returned to the oil pan, it is necessary to provide a dedicated flow path, which complicates the pump case.

An oil pump for an outboard motor according to the present invention was invented in consideration of these problems. A first object of the invention is to determine the positions of a suction hole and a discharge hole formed in a pump case. , Can be freely laid out regardless of the position of the drive shaft, suction port and discharge port, and can easily form the inlet and outlet without depending on drilling while preventing oil leakage from the outlet where internal pressure increases It is also possible to avoid deterioration of the lubrication state immediately after starting the engine.

A second object of the outboard motor oil pump according to the present invention is to make the pump case compact and simple.

[0011]

To achieve the above object, an oil pump for an outboard motor according to the present invention comprises an engine holder,
The lubricating oil in an oil pan provided on the lower surface of the engine holder is installed between the engine and the vertically mounted engine with the crankshaft standing upright on the upper surface of the engine holder and driven by the crankshaft. The oil pump of the outboard motor, which pumps the oil through an oil strainer and supplies the oil to an oil gallery provided inside the engine, includes a pump case forming an oil pump, a case body, and a liquid-tight covering on the case body. And a case cover that accommodates an inner rotor and an outer rotor that are rotationally driven by the crankshaft inside the pump case.
A suction port and a discharge port which are symmetrically located with respect to the crankshaft are formed, and the suction port is disposed on the front side of the crankshaft away from the center of the engine in plan view, and the discharge port is positioned on the crankshaft. In addition to being disposed on the rear side that is the center side of the engine, a suction hole and a discharge hole are provided at a rear position that is further on the center side of the engine than the discharge port in plan view, and the suction hole is connected to the oil strainer, While the discharge port is connected to the oil gallery, the inlet for connecting the suction port to the suction port and the outlet for connecting the discharge port to the discharge port are each formed in a groove shape on the case cover mounting surface on the case body side. Forming and covering the case cover to form a closed conduit, and connecting the inlet to the outer Around the outer periphery of one side of the rotor from the back to the front about half way around, connecting the suction port and the suction port, and arranging the outlet behind the discharge port and on the opposite side of the inlet, and The discharge port is laid out so as to connect the discharge port and the discharge hole with a short path.

According to a second aspect of the present invention, there is provided an oil pump for an outboard motor according to the first aspect, wherein a relief hole is provided in the middle of the outlet, and the relief hole is connected to the oil pump. And was connected to a relief valve provided on another member adjacent to.

[0013]

According to the first aspect of the invention, since the inlet and the outlet can be formed in a non-linear manner, the suction hole and the discharge hole can be connected to the suction port and the discharge port by free routes. Therefore, regardless of the positions of the crankshaft, the suction port, and the discharge port, the suction hole and the discharge hole can be provided at free positions, thereby improving the layout. In addition, since the inlet and outlet are formed at the same time as the casting (forging) of the case body, it is easy to form, and does not require additional processing such as drilling or the like, and does not require plugging.

In addition, since the oil gallery of the engine is generally formed on the center side (rear side) of the engine with respect to the crankshaft in plan view, both the discharge hole and the discharge port connected to the oil gallery are located closer to the center of the engine than the crankshaft. By forming it on the side, the length of the outlet can be shortened as much as possible, and oil leakage from the outlet where the internal pressure increases can be effectively prevented.

Further, as described above, the length of the outlet is increased by an amount corresponding to the shortened length of the outlet. The intake port located upstream of the inlet is located behind the intake port located downstream, so the outboard motor is tilted up to start the engine. When stopped, a large amount of lubricating oil remains inside the inlet,
As a result, the time until the lubricating oil starts to be discharged from the oil pump at the time of the next engine start is shortened, and deterioration of the lubrication state immediately after the start can be avoided.

According to the second aspect of the present invention, since the relief valve can be formed on another member adjacent to the oil pump, the pump case is reduced in size and simplified.

[0017]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a right side view of an outboard motor 1 having an outboard motor oil pump according to the present invention.

In this outboard motor 1, an engine 5 is mounted on a substantially flat engine holder 3 mounted on the uppermost part of a main body casing 2 with a crankshaft 4 standing upright. Is transmitted to a propeller shaft 8 via a drive shaft 6 suspended in the main body casing 2 and a forward / reverse switching device 7 to drive the propeller 9 forward or reverse. is there.

Since the engine 5 mounted on the engine cover 11 is a four-stroke engine, an oil pan 12 communicating with the engine 5 is provided below the engine holder 3.
Is installed.

The outboard motor 1 is attached to the hull 14 by a clamp bracket 13 pivotally attached to the main casing 2 and the engine holder 3 so as to be rotatable left and right, and the hull 14 is propelled for steering.

FIG. 2 is a longitudinal sectional view of the engine 5. The engine 5 is, for example, an SOHC type having four cylinders arranged in series, and is formed by a cylinder head 15, a cylinder block 16, a crankcase 17, and a head cover 18, and the cylinder head 15 and the cylinder block 1 are formed.
6 are fixed to the engine holder 3.

Cylinder block 16 and crankcase 1
Reference numeral 7 defines a crank chamber 19, and a crank shaft 4 is rotatably supported by a crank bearing 21 formed on a mating surface of the two members 16 and 17. Also cylinder block 1
The reciprocating motion of the piston 23 slidable in the four cylinders 22 formed in 6 is converted into the rotational motion of the crankshaft 4 via the connecting rod 24 and becomes the output of the engine 5.

On the other hand, the cylinder head 15 and the head cover 18 define a cam chamber 25, and an internal cam bearing 26
, A cam shaft 27 is rotatably supported. The camshaft 27 is driven by the crankshaft 4 via a timing belt 28 and the like, and the cams 31 and 32 of the camshaft 27 actuate the valve train 33 to operate the valves 34 and 3.
5 is opened in the cylinder 22 at a predetermined timing,
Gas exchange in the cylinder 22 is performed.

Oil pump 36 for lubricating engine 5
Is installed at a portion where the crankshaft 4 protrudes from the lower surface of the engine 5 and is directly driven by the crankshaft 4.

The suction hole 37 of the oil pump 36
An oil strainer 38 fixed so as to be immersed in the lubricating oil O stored in the oil pan 12 is connected by an oil pipe 39. The discharge hole 41 opens toward the engine 5 side.

FIG. 3 shows a lubricating oil supply path of the engine 5.

The cylinder block 16 is provided with a main gallery 42 parallel to the crankshaft 4 and an oil supply passage 43 connecting the main gallery 42 to the lower surface of the engine 5. The position of the hole 41 matches the inlet of the oil supply path 43.

From the main gallery 42, a crank lubricating oil passage 44 communicating with the crank bearing 21 and a cam lubricating oil passage 45 communicating with the cam bearing 26 and the valve gear 33.
And have branched.

When the engine 5 operates, the oil pump 36 is driven by the rotation of the crankshaft 4, and the lubricating oil in the oil pan 12 is filtered by the oil strainer 38 and pumped up, and is discharged from the discharge hole 41.
The discharged lubricating oil flows into the main gallery 42 through the oil supply path 43 and is
And diverted to a cam lubricating oil flow passage 45, the crankshaft 4, the cylinder 22, the piston 23, and the connecting rod 24.
And the like, and lubricate the camshaft 27, the valve gear 33, and the like.

FIG. 4 is a vertical sectional view of the oil pump 36, and FIG. 5 is a view taken along the line V--V in FIG. 4, showing an embodiment of the present invention.

Pump case 4 forming oil pump 36
7 is formed by covering a case body 48 with a case cover 49, and the case body 48 has an outer toothed inner rotor 50 that rotates integrally with the crankshaft 4.
, An inner-tooth-shaped outer rotor 51 meshing with the inner rotor 50 and rotating in the same direction is arranged. The number of teeth of each of the rotors 50 and 51 is smaller by one in the inner rotor 50 than in the outer rotor 51. For example, the inner rotor 50 has four teeth and the outer rotor 51 has five teeth. For this reason, a gap serving as the oil transfer chamber 52 is formed between the inner rotor 50 and the outer rotor 51.

The suction port 53 and the discharge port 5 adjacent to the lower surfaces of the inner rotor 50 and the outer rotor 51
4 are provided symmetrically around the crankshaft 4 so as to sandwich the crankshaft 4, and are formed in opposing fan shapes, each surrounding the circumference of the crankshaft 4 by a half circumference, and formed by an inlet 55 and an outlet 56, respectively. It is connected to the.

The above inlet 55 and outlet 5
Numerals 6 are formed in a groove shape on the upper surface of the case main body 48, that is, the surface on which the case cover 49 is mounted. When the case cover 49 is mounted on the case main body 48, a closed pipe shape is formed. It is configured as follows.

The suction hole 37 is provided in the case body 48 as a hole that escapes from the starting point of the inlet 55 to the oil pan 12 side, while the discharge hole 41 is a hole that escapes from the end point of the outlet 56 to the engine 5 side. It is provided on the cover 49.

Inlet 55 and outlet 56
And the suction hole 37 and the discharge hole 41 are both
8 and the case cover 49 are formed at the same time as the casting (forging) production, so that no additional processing such as drilling is required.

The rotation of the crankshaft 4 drives the inner rotor 50 and the outer rotor 51,
When rotated (clockwise in FIG. 5), the volume of the oil transfer chamber 52 increases at the position of the suction port 53, and
It decreases at position 4. Therefore, the suction port 53
Lubricating oil is sucked into the oil transfer chamber 52 and
4 and discharged. Thus, the oil pump 36
The lubricating oil is continuously sucked through the suction hole 37, discharged through the discharge hole 41, and supplied to the oil supply passage 43 of the engine 5.

In the oil pump 36, the intake port 53 is disposed on the front side of the engine 5 away from the center of the crankshaft 4 in plan view (see FIG. 5), and the discharge port 54 is connected to the engine 5 with respect to the crankshaft 4. It is arranged on the rear side, which is the center side. Further, the suction hole 37 and the discharge hole 41 are provided further on the center side (rear position) of the engine 5 than the discharge port 54 in plan view.
Therefore, the suction port 37 and the discharge port 41 are larger than the suction port 53 and the discharge port 54 in the oil pan 1 in plan view.
It is located on two sides.

On the other hand, in plan view, the inlet 55 is laid out so as to bypass the outer periphery of one side (for example, the right side) of the outer rotor 51 from the rear to the front by about half the circumference and to connect the suction port 37 and the suction port 53, The outlet 56 is led out of the outlet port 54 and on the opposite side of the inlet 55, and is connected to the outlet port 5 through a path much shorter than the inlet 55.
4 and the discharge holes 41 are laid out.

The outlet 56 is bent at a substantially right angle in the middle thereof, and a relief hole 57 is provided in the bent portion. This relief hole 57 communicates with a relief valve 58 provided in the engine holder 3 adjacent to the oil pump 36, as shown in FIG. 6A (a longitudinal sectional view along the line VI-VI in FIG. 5). I have.

The relief valve 58 includes a valve cylinder 59 and an oil pan 1 from the valve cylinder 59.
A valve piston 61 having a relief channel 60 branched into the valve cylinder 2 and slidable in the valve cylinder 59 is pressed by a spring 62 to close the relief channel 60.

When the oil pressure in the outlet 5 exceeds a certain value, as shown in FIG. 6B, the excess pressure passes through the relief hole 57 and is applied to the valve piston 61 of the relief valve 58. 61 to spring 6
Outlet 56 to push down against the spring force of
Communicates with the relief flow channel 60 and a part of the lubricating oil O in the outlet 56 is returned to the oil pan 12, so that the discharge pressure of the oil pump 36 is maintained without exceeding the set value.

The oil pump 3 configured as described above
6, the position of the suction hole 37 and the position of the discharge hole 41 are not limited as in the conventional oil pump. That is, the inlet 55 and the outlet 56 which are formed in a groove shape on the upper surface of the case body 48 can be formed in a non-linear manner along an arbitrary route. It is not necessary to dispose it near the discharge port 54, and the suction hole 37 and the discharge hole 4 are independent of the positions of the crankshaft 4, the suction port 53, the discharge port 54 and the like.
1 can be freely laid out and connected to the suction port 53 and the discharge port 54 via the inlet 55 and the outlet 56.

In this way, especially, the discharge hole 41 is
Can be directly connected to the oil supply passage 43, so that there is no need to provide a dedicated guide passage connecting the discharge hole 41 and the oil supply passage 43 as in the related art, and the cylinder block 16 and the engine holder 3 are not required. Costs can be reduced by simplifying the shape of the structure around the engine.

Further, since the inlet 55 and the outlet 56 are simultaneously formed at the time of casting (forging) of the case body 48, additional processes such as drilling and the like, and a process of closing an external port by a plug are required. Therefore, it can be formed very easily, and the cost can be significantly reduced.

In the oil pump 36, the discharge port 41 and the discharge port 54 connected to the oil gallery 42 are both formed closer to the center (rear side) of the engine 5 than the crankshaft 4 in plan view. Since the oil gallery 42 is formed closer to the center of the engine than the crankshaft 4, the length of the outlet 56 can be reduced. By reducing the length of the outlet 56, it is possible to effectively prevent oil leakage from the outlet 56 whose internal pressure increases due to the high discharge pressure of the oil pump 36.

As described above, the length of the inlet 56 is increased by the reduced length of the outlet 56.
The inlet 55 extends substantially in the front-rear direction, and since the suction hole 37 located on the upstream side is located behind the suction port 53 located on the downstream side, the outboard motor 1 is tilted up. When the engine 5 is stopped, the inlet 55 is inclined forward and downward, and a large amount of lubricating oil remains therein. Therefore, the time until the lubricating oil starts to be discharged from the oil pump 36 when the engine 5 is started next time is shortened, and deterioration of the lubrication state immediately after the start can be avoided.

Further, the suction hole 37 is
Is formed closer to the center of the engine 5, the suction hole 37 is located near the upper side of the oil pan 12, and thus the oil pipe 3 connected to the oil strainer 38.
9 can be shortened to improve the layout. At the same time, the layout of the oil passages formed on the engine 5 side can be improved.

Further, according to the configuration of the oil pump 36, when installing the relief valve 58, it is only necessary to provide the relief hole 57 in the pump case 48, and the relief valve 58 must be formed integrally with the pump case 48. Since there is no pump case, the pump case 48 can be reduced in size and simplified.

The present invention can be applied to oil pumps of a type other than the trochoid pump.

[0051]

As described above, according to the oil pump of the outboard motor according to the present invention, the positions of the suction hole and the discharge hole formed in the pump case are changed to the positions of the drive shaft, the suction port, and the discharge port. In addition to being able to lay out freely regardless of whether or not the inlet and outlet can be easily formed without depending on drilling,
It is possible to effectively prevent oil leakage from the outlet where the internal pressure is increased, to avoid deterioration of the lubrication state immediately after the start of the engine, and to reduce the size and simplification of the pump case.

[Brief description of the drawings]

FIG. 1 is a right side view of an outboard motor including an outboard motor oil pump according to the present invention.

FIG. 2 is a longitudinal sectional view of an engine of the outboard motor.

FIG. 3 is a diagram showing a lubricating oil supply path of the engine.

FIG. 4 is a longitudinal sectional view of the oil pump.

5 is a view taken in the direction of arrows VV in FIG. 4, showing an embodiment of the present invention.

6A is a longitudinal sectional view of the vicinity of a relief valve taken along the line VI-VI in FIG. 5, and FIG. 6B is a view showing an operation state of the relief valve.

FIG. 7 is a diagram showing a conventional technique.

[Explanation of symbols]

 Reference Signs List 1 outboard motor 3 engine holder 4 crankshaft 5 engine 6 drive shaft 12 oil pan 36 oil pump 37 suction hole 38 oil strainer 41 discharge hole 42 oil gallery 43 oil supply path 47 pump case 48 case body 49 case cover 50 inner rotor 51 outer rotor 52 oil transfer chamber 53 suction port 54 discharge port 55 inlet 56 outlet 57 relief hole 58 relief valve O lubricating oil

Claims (2)

(57) [Claims] 1. An engine holder and an engine vertically mounted on the upper surface of the engine holder with the crankshaft upright. The engine is driven by the crankshaft to provide a lower surface of the engine holder. In an oil pump of an outboard motor which supplies lubricating oil in an oil pan provided by filtering through an oil strainer and supplies it to an oil gallery provided inside the engine, a pump case forming an oil pump includes a case body, The case body is provided with a case cover that is mounted in a liquid-tight manner, and the pump case accommodates an inner rotor and an outer rotor that are rotationally driven by the crankshaft, and is symmetrical about the crankshaft. The suction port and the discharge port are located The suction port is arranged on the front side of the crankshaft away from the center of the engine, and the discharge port is arranged on the rear side that is the center side of the engine with respect to the crankshaft. An inlet for connecting the suction hole to the oil gallery while connecting the suction hole to the oil strainer by connecting the suction hole to the oil gallery, and an inlet for connecting the suction hole to the suction port; Outlets for connecting the discharge ports to the discharge holes are formed in a groove shape on the case cover mounting surface of the case body side, and the case cover is mounted thereon to form a closed conduit, and in plan view. The inlet is detoured around the outer periphery of one side of the outer rotor from back to front by about half a turn to connect between the suction hole and the suction port. -Out, the oil pump of an outboard motor, characterized in that the laid out so derive the outlet on the opposite side of the rear and the inlet of the discharge port connecting between the discharge port and the discharge hole in the short path than the inlet. 2. The outboard motor oil pump according to claim 1, wherein a relief hole is provided in the middle of the outlet, and the relief hole communicates with a relief valve provided on another member adjacent to the oil pump.