JP3380355B2 - Structure to prevent oil from entering air bubbles into oil pump of internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing bubbles formed in an oil pan by oil discharged from a relief valve for preventing the pressure of oil supplied to a lubricating portion of an internal combustion engine from rising above a predetermined pressure. The present invention relates to a structure for preventing oil from entering air bubbles into an oil pump of an internal combustion engine in which contained oil is not sucked into an oil pump.

[0002]

2. Description of the Related Art In an internal combustion engine, particularly a four-stroke internal combustion engine, oil collected in an oil pan at the bottom of the engine is pumped to each lubricating part by an oil pump, and the lubricated oil is returned to the oil pan by gravity. The oil was circulated to each lubrication unit.

In such an internal combustion engine, a certain large-sized oil pump is used in order to secure a necessary oil supply when the engine is running at a low speed. And since a normal oil pump has a characteristic that the oil supply amount increases in accordance with the number of rotations, at the time of high-speed rotation, in order to prevent supply of unnecessarily high oil under high pressure, the oil pump A relief valve is interposed in the oil passage leading to the lubricating portion, and when the pressure in the oil passage becomes higher than a predetermined set pressure, the relief valve is opened, and the oil in the oil passage is discharged from the oil pan. Was to be returned.

The relief valve is usually immersed in the oil of an oil pump. When the relief valve is opened, the oil is vigorously injected from the discharge port of the relief valve. The oil foams, and the surrounding air is entrained in the oil together with the injected oil, so that many bubbles are formed in the oil in the oil pan.

When the oil containing the bubbles is sucked into the oil pump, some of the bubbles are crushed when the pressure rises in the oil pump, and noise is generated. Is easily damaged.

In order to solve such a problem, Japanese Unexamined Utility Model Publication No. Sho 61-17204 discloses an oil strainer connected to the suction end of an oil pump and a discharge port of a relief valve. In order to prevent the oil containing bubbles from being discharged from the relief valve from being sucked into the oil pump.

[0007]

In the apparatus described in Japanese Utility Model Publication No. Sho 61-17204, the partition wall is divided into a partition wall portion that extends downward from the engine body and a partition wall portion that extends upward from the bottom of the oil pan. However, the shape of the mold for casting the engine body becomes complicated, and the number of processing steps for forming the partition part of the oil pan increases, and the two partition parts are accurately aligned. As a result, cost increase is unavoidable and weight reduction is difficult.

Particularly, in an internal combustion engine in which a crankcase integrated with an oil pan is divided into two parts by a vertical plane, it is difficult to form a concave portion forming the partition in a crankcase mold.

[0009]

SUMMARY OF THE INVENTION The present invention relates to an improvement in a structure for preventing oil from entering air bubbles into an oil pump of an internal combustion engine, which overcomes such difficulties, and which is connected to a suction port of the oil pump. In an internal combustion engine in which an oil strainer and a relief valve interposed in an oil passage connecting the oil pump and a lubricating portion of the internal combustion engine to each other are immersed in oil in the same oil pan, the oil pump and the oil Strainer and relief valve
Are integrated with each other in the oil pan to form an internal combustion engine.
Is mounted on the main, the oil strainer and Ririfuba
A bulkhead is integrally protruded from the oil pump body between the lubes.
It is characterized by having been done .

Since the present invention is configured as described above, an oil pump, an oil strainer and a relief are provided.
The valve is easily removed from the internal combustion engine body and is very easily
Mamoru, inspection, it is possible to carry out the maintenance, yet oil stray
Between the oil pump body and the relief valve
The oil pump is even more reliably provided by the installed partition
Air bubbles can be prevented from being mixed in.

[0011] The present invention is configured as described in claim 2.
Mutual and allows the lubrication oil pump and an internal combustion engine
The oil pressure in the oil passage connected to the
Pressure in the oil passage exceeds the relief pressure.
From the oil pan into the oil pan.
Even if bubbles occur in the oil, the discharge port of the relief valve
Oil containing a lot of air bubbles near the suction cover
At the part close to the relief valve, face the bottom of the oil pan.
To the oil strainer suction port
Oil that contains a lot of air bubbles
Is prevented from being sucked into the oil pump.

Further , according to the present invention, the oil mixed with bubbles is oily.
The part that prevents the pump from being sucked into the oil pump.
Because it is formed in the Lena, especially to the engine body and the oil pan
There is no need to provide a separate partition, and the number of parts is reduced.
Simplification and cost reduction and weight reduction.
it can.

[0013]

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention shown in the drawings will be described below.

FIG. 1 is a longitudinal sectional rear view of an internal combustion engine 1 mounted on a large motorcycle (not shown) cut along a vertical plane in a vehicle width direction and viewed from the rear of the vehicle body toward the front of the vehicle body. Reference numeral 1 denotes a horizontally opposed six-cylinder internal combustion engine in which cylinders 2 oriented in the left-right direction are arranged in three cylinders in the front-rear direction.

The internal combustion engine 1 is divided into right and left engine bodies 3L, 3R along the front-rear vertical plane passing through the center of the vehicle width.
A cylinder head 4 detachably attached to the two divided engine bodies 3L, 3R, and a cylinder head cover 5 detachably attached to the cylinder head 4. The upper part of the engine bodies 3L, 3R A cylinder block is formed at the bottom, and an oil pan is formed integrally with the cylinder block below the cylinder block.

Further, as shown in FIG. 1, a crankshaft 6 is rotatably supported at a position where the split surfaces of the left and right engine bodies 3L and 3R intersect with the center line of the cylinder 2. The piston 7 and the crank pin of the crankshaft 6 which are slidably fitted to each other are connected by a connecting rod 8 so that the reciprocating motion of the piston 7 in the cylinder 2 drives the crankshaft 6 to rotate. Has become.

Furthermore, a cam shaft 9 is rotatably supported at a position where the split surface of the cylinder head 4 and the cylinder head cover 5 intersects the center line of the cylinder 2, and the cam shaft 9 is rotated via a transmission mechanism (not shown). The camshaft 9 is connected to the crankshaft 6, and is driven to rotate at half the rotation speed of the crankshaft 6.

In addition, as shown in FIG. 1, a main shaft 11 and a countershaft 12 are arranged in parallel with the crankshaft 6 in a crankcase 10 located below the engine body 3.
And the main shaft 11 is connected to the crankshaft 6 via a clutch (not shown),
The counter shaft 12 is connected to the main shaft 11 via a main shaft 11 and a reduction gear group fitted to the counter shaft 12, respectively, and a rear wheel drive shaft (not shown) is connected to the counter shaft 12, When the shifter 14 engaged with the shift drum 13 is moved back and forth by the rotation of the shift drum 13 during operation, the meshing relationship of the reduction gear group is changed, and the rear wheel drive shaft is driven to a required speed. It is designed to be driven to rotate at a ratio.

The oil pump 15 has a pump body 16.
A pump cover 17, a pump shaft 18 rotatably supported by the pump body 16 and the pump cover 17,
An inner rotor 19 integrally fitted to the pump shaft 18
The outer 20 fitted to the pump body 16 and the inner rotor 19 are slidably fitted in the radial groove of the inner rotor 19, and the outer edge thereof slides along the inner peripheral surface of the outer 20 together with the inner rotor 19. It consists of a rotating vane (not shown).

Further, as shown in FIG. 3, the oil pump 15 is mounted on the engine body 3L by mounting bolts 21 penetrating the pump cover 17, and the pump shaft 18 of the oil pump 15 is mounted on the engine body 3L. A sprocket 22 penetrating the rear wall and fitted to the rear end of the pump shaft 18 is connected to a sprocket of the crankshaft 6 via a chain (not shown). The pump shaft 18 is driven to rotate at a fixed ratio with respect to the rotation speed of the pump 6.

Further, the pump cover of the oil pump 15
17 is a suction port of the oil pump 15 shown in FIG.
A suction passage 25 communicating with the suction pipe 23 is formed, a suction end of the suction passage 25 is opened downward, a suction pipe 29 of an oil strainer 28 is fitted to the suction end, and the suction pipe 29 is attached integrally. A bolt (not shown) engaged with a notch 31 (see FIG. 7) of the flange piece 30 is screwed to the pump cover 17, and the oil strainer 28 is integrally mounted on the oil pump 15. .

Further, as shown in FIG. 7, a strainer body 32 is fitted to the lower end of the suction pipe 29 of the oil strainer 28, and the lower end opening edge 33 of the strainer body 32 is shown in FIG. As such, a ring-shaped piece 36 integrally joined to the tip of a support piece 35 of a wire mesh stopper 34 that is oriented radially with a 120 ° interval from the center, an outer peripheral edge of a wire mesh 37, The upper end opening edge 39 of the suction cover 38 is sequentially overlapped, and the lower end opening edge 33 of the strainer main body 32 is curved in a U-shaped cross section and caulked, so that the lower end opening edge 33 of the strainer main body 32 is formed. The ring-shaped piece 36 of the wire mesh stopper 34, the outer peripheral edge of the wire mesh 37, and the upper opening edge of the suction cover 38
39 are joined together.

In the suction cover 38, as shown in FIGS. 2 and 3, a downwardly bulging portion 40 is formed at a front portion (right side in the drawing) of the vehicle body, and at a rear portion of the vehicle body. FIG. 6 shows a bottom raised portion 41 which is drawn upward.
As shown in the drawing, a substantially semicircular inlet
42 are provided.

A discharge passage 26 is formed in the pump body 16 of the oil pump 15 so as to be directed forward (to the right in FIG. 3, to the left in FIG. 5). 1 (rightward in FIG. 1 and leftward in FIG. 4), a discharge passage 27 communicating with the discharge passage 26 is formed, and a valve casing 45 of a relief valve 44 is fitted to an end of the discharge passage 27. As shown in FIG. 4, mounting bolts penetrate a flange piece 51 integral with the valve casing 45.
The relief valve 44 is integrally mounted on the pump body 16 by screwing and tightening the 52 to the pump body 16.

Further, as shown in FIG. 4, a piston 46 is provided on a valve casing 45 of the relief valve 44.
The compression coil spring 49 is interposed between a spring receiver 48 and a piston 46 which are engaged with a circlip 47 fitted to the opening edge of the valve casing 45, and discharge is performed. When the discharge pressure in the passages 26 and 27 exceeds a predetermined set pressure, the piston 46 overcomes the spring force of the compression coil spring 49 and moves toward the spring receiver 48, and the discharge port 50 of the valve casing 45 is opened. ,
Pressure oil is discharged.

Further, as shown in FIG.
The two ends of a communication pipe 54 are fitted into the front opening end of the vehicle body 26 and the lower opening end of an oil passage 53 which is opened in front of and opposed to the front end of the oil passage 53.
The oil supplied from the discharge passage 26 of the oil pump 15 to the suction portion 56 of the oil filter 55 through the communication pipe 54 and the oil passage 53 passes through the filter element 57 and is filtered. After that, it reaches the discharge part 58,
The oil in the discharge portion 58 is supplied to lubricating portions such as a pivot portion of the crankshaft 6 and the camshaft 9 of the internal combustion engine 1 and a sliding portion of the piston 7 via an oil passage (not shown). I have.

A front end of the pump shaft 18 of the oil pump 15 is provided with a water pump 59 for cooling the internal combustion engine 1.
Of the oil pump 15
Is driven to rotate, the water pump 59 is also driven to rotate at the same time.

Further, as shown in FIG. 2, the pump body 16 of the oil pump 15 covers the upper part and the rear part of the valve casing 45 of the relief valve 44, and is located on the right side of the vehicle body with respect to the pump body 16 (see FIG. 1). A directed partition wall 61 (a hatched portion in FIG. 2) is formed integrally with the pump body 16.

The oil level in the engine body 3 is shown in FIG.
3 is maintained between an upper oil level 62 and a lower oil level 63 shown in FIG.

Since the illustrated embodiment is configured as described above, when the internal combustion engine 1 is in operation, the oil pump is rotated at a rotational speed proportional to the rotational speed of the crankshaft 6.
15 and the water pump 59 are driven to rotate, and FIGS.
As shown in FIG. 2, oil in the internal combustion engine 1 is introduced into the oil pump 15 from an intake port 42 opened at a rear position of the vehicle body from an intake pipe 29 of an oil strainer 28 fitted to the intake end of the intake passage 25. After being sucked and pressurized by the oil pump 15, the oil is supplied to the oil filter 55 via the discharge passage 26, the communication pipe 54 and the oil passage 53, and the oil filtered by the oil filter 55 is supplied to an oil passage (not shown). Is supplied to each lubrication unit of the internal combustion engine 1 via the

When the oil collected at the bottom of the internal combustion engine 1 is sucked into the oil pump 15, large debris in the oil is removed by the wire netting 37 in the oil strainer 28, so that the oil pump 15 operates smoothly. Can be driven.

When the oil pressure in the discharge passage 27 communicating with the discharge passage 26 of the oil pump 15 exceeds the set pressure of the relief valve 44, the relief valve 44 is opened, and the pressure oil in the discharge passage 27 is discharged from the discharge port. The fuel is discharged from the engine 50 into the internal combustion engine 1 as shown in FIG.
The oil discharged from the discharge port 50 of the relief valve 44 flows to the right side of the vehicle body due to the presence of the partition wall 61 further rearward and upward, and bubbles in the oil rise at the right front portion at the bottom of the internal combustion engine 1. Separated from the oil.

Further, the oil from which bubbles are sufficiently removed is as follows:
It flows toward the rear of the vehicle body and to the left of the vehicle body as shown in FIG.
The oil containing air bubbles is sucked into the oil pump 15 from the suction port 42 of the bottom raising part 41 in the oil pump.
It is prevented from being inhaled in 15.

Further, a bulging portion 40 protrudes downward from the suction port 42 of the raised bottom portion 41 of the suction cover 38 of the oil strainer 28 to the vicinity of the bottom surface of the internal combustion engine 1 in front of the vehicle body. The bottom raising part 41 from the front of the car body
The flow of oil to the suction port 42 is prevented, so that the suction of the bubble-mixed oil into the oil pump 15 is more reliably prevented.

The oil strainer 28 is connected to the oil pump 15.
And the relief valve 44 are integrally assembled, and the pump cover 17 of the oil pump 15 is detachably attached to the internal combustion engine 1 by the mounting bolt 21. If removed, the oil strainer 28 and the relief valve 44 are also taken out of the internal combustion engine 1 together with the oil pump 15, so that the oil pump 15, the oil strainer 28 and the relief valve 44 can be very easily maintained, inspected and maintained.

Further, since the partition wall 61 is formed integrally with the pump body 16 of the oil pump 15, the partition wall 61 is disposed at the most appropriate position with respect to the relief valve 44 irrespective of the split surface of the internal combustion engine 1. be able to.

[Brief description of the drawings]

FIG. 1 is a rear view of an internal combustion engine provided with a structure for preventing air from entering an oil pump into an oil pump according to the present invention, in which essential parts are partially omitted.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a longitudinal sectional side view taken along the line II-II of FIG. 1;

FIG. 4 is a partial cross-sectional view of the oil pump cut along a line IV-IV in FIG. 2;

FIG. 5 is a vertical sectional view cut along the line VV in FIG. 4;

FIG. 6 is a bottom view of the oil strainer.

FIG. 7 is a vertical sectional view taken along the line VII-VII of FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Cylinder, 3 ... Engine main body, 4 ... Cylinder head, 5 ... Cylinder head cover, 6 ... Crankshaft, 7 ... Piston, 8 ... Connecting rod,
9 camshaft, 10 crankcase, 11 main shaft, 12 counter shaft, 13 shift drum, 14 shifter, 15 oil pump, 16 pump body, 17 pump cover, 18 pump shaft, 19 ... Inner rotor, 20
... Outer, 21 ... Mounting bolt, 22 ... Sprocket, 23
... Suction port, 24 ... Discharge port, 25 ... Suction passage, 26,27
... discharge passage, 28 ... oil strainer, 29 ... suction pipe, 30 ...
Mounting flange piece, 31… Notch, 32… Strainer body, 33
... lower edge opening edge, 34 ... wire mesh stopper, 35 ... support piece,
36 ... ring-shaped piece, 37 ... wire mesh, 38 ... suction cover, 39 ... upper edge of opening, 40 ... bulging part, 41 ... bottom raising part, 42 ... suction port,
43 ... Slope surface part, 44 ... Relief valve, 45 ... Valve casing, 46 ... Piston, 47 ... Circle, 48 ... Spring receiver, 49 ... Compression coil spring, 50 ... Discharge port, 51 ...
Flange, 52 mounting bolt, 53 oil passage, 54 communication pipe, 55 oil filter, 56 suction unit, 57 filter element, 58 discharge unit, 59 water pump, 60 pump shaft, 61 Partition wall, 62: Upper oil level, 63: Lower oil level.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F01M 11/06 F01M 1/02 F01M 11/00 F01M 11/03

Claims (2)

(57) [Claims] An oil strainer connected to a suction port of an oil pump and a relief valve interposed in an oil passage interconnecting the oil pump and a lubricating portion of an internal combustion engine are provided in the same oil pan. Oil pump and oil strainer in an internal combustion engine immersed in
Over Na and the relief valve are mutually in said oil pan
Are integrated is mounted on the internal combustion engine body, said Oirusuto
From the oil pump body between the rainer and the relief valve
A structure for preventing oil from entering air bubbles into an oil pump of an internal combustion engine, wherein a partition wall is integrally protruded . 2. A suction valve is provided at a suction end of the oil strainer.
A bar is integrally mounted, and the release cover is
A suction port is formed at a location away from the discharge port of the valve
At the same time between the relief valve and the suction port.
Block the oil near the valve to the suction port.
Bulging portion is formed so as to approach the oil pan bottom.
2. The structure for preventing oil from entering air bubbles into an oil pump of an internal combustion engine according to claim 1.