JPS6390610A - Oil pan structure for internal combustion engine - Google Patents

Abstract

PURPOSE:To restrain a crank shaft from being deformed due to the rotational vibration thereof affecting upon the wall surface thereof at the peripheral surface of the part adjacent to a bearing in order to reduce the radiation of vibration noise, by connecting the intermediate parts of inner wall surfaces facing together with the use of a reinforcing member. CONSTITUTION:An oil pan 1 is formed in a box-like shape having a trapezoidal cross-section, with front and rear walls 50a, 50b, left and right walls 51a, 51b having lower parts inclined downward and a bottom wall 52 set horizontally. Bearing parts 54, 55 for a crank shaft and a balancer are formed in the center part and both side parts of the opened surfaces 53 of the front and rear walls 50a, 50b, respectively. In this arrangement, a plurality of axial reinforcing members 56 which connects the inner surfaces of the front and rear walls 50a, 50b, integrally with each other, are laid directly below the center axes of the bearing parts 54, 55. Further, a widthwise reinforcing member 57 connecting the inner surfaces of the left and right walls 51a, 51b with each other and connecting axial members 56 integrally with each other, is laid orthogonal to the axial members 56.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an oil pan structure for an internal combustion engine, and particularly to an oil pan 4MM improved to increase rigidity.

<Prior Art> The oil pan of an internal combustion engine is generally connected to a skirt portion of a cylinder block to form a crankcase.

Therefore, in order to suppress fluctuations in the crankcase internal pressure due to the reciprocating movement of the piston as small as possible and to provide a stable supply of lubricating oil, a relatively large oil pan volume is required.

On the other hand, engine operating noise caused by explosion vibrations, etc.
Although the noise is radiated to the outside through the crankshaft and the main journal of the cylinder block, it becomes a large-volume A-ilpan, a resonance box, and has the disadvantage of promoting noise radiation.

In order to reduce such Mi sound radiation from the oil pan, it is effective to increase the rigidity of the oil pan to suppress the generation of vibration.
5M publication or Utility Model Application Publication No. 56-147332,
An oil pan structure is disclosed in which the rigidity is increased by providing reinforcing materials and ribs along the wall surface of the oil pan.

<Problems to be Solved by the Invention> By the way, especially in the case of an oil pan structure in which the bearing cap is integrally formed on the oil pan wall surface, the vibration of the crankshaft is directly transmitted. It is easy to deform in the axial direction, and if you try to obtain sufficient rigidity only with reinforcing materials such as ribs as in the past, the weight tends to increase and the structure becomes complicated.

In view of this disadvantage of the prior art, the main object of the present invention is to provide an oil pan structure for an internal combustion engine that can obtain high rigidity without increasing the relatively small G1.

According to the present invention, the object is to provide an oil pan structure that forms a part of the crankcase of an internal combustion engine and has a box-like shape for storing lubricating oil. This is achieved by providing an oil pan structure for an internal combustion engine, which is characterized in that intermediate portions of opposing inner wall surfaces are connected by a reinforcing material.

<Operation> By doing this, the mutually opposing wall surfaces are rigidly connected, and the deformation of the wall surface around the portion adjacent to the bearing due to the rotation of the crankshaft is suppressed, thereby reducing the emission of vibration noise. q" can be reduced.

Embodiments The present invention will now be described in detail with reference to specific embodiments with reference to the accompanying drawings.

FIGS. 1 to 3 show the rest of an air-cooled deep-pil engine to which the oil pan structure (blue) according to the present invention is applied. This diesel engine has an oil pan 1 integral with a crankcase, a cylinder block 2, a cylinder head 3 attached to the upper part of the oil pan 1, and a head cover 4.

A cylinder liner 6 is installed inside the cylinder 5 formed in the cylinder block 2, and a piston 7 is movably disposed inside the cylinder liner 6.

The screws 1 to 7 are connected to the crankshaft 9 via a connecting rod 8, and are reciprocated in the vertical direction to rotate the crankshaft 9.
It is designed to rotate. A crankcase cover 11 is attached to the output shaft 10 side of the crankshaft 9.
A cooling fan 12 is provided at the end opposite to the output shaft 10.
is fixed, and a coil starter 13 for manually starting the engine is attached to the outside thereof (-=J).

The cooling fan 12 has a large number of fins 14 attached to the crankshaft 9.
When the cooling fan 12 rotates with the rotation of the crankshaft 9, it passes through the inside of the guide plate 15 attached to the end face of the cooling fan 12 in the axial direction. The air flows along a passage 17 formed inside a hood cover 16 that covers substantially the entire axial end surface of the engine, cooling the cylinder block 2 and cylinder head 3. do.

Inside the cylinder head 3, a unit injector 18 is fixed with a mounting pole (~19) together with a redistributed valve mechanism.A fuel tank 20 is arranged on the left side of the cylinder head 3 in FIG. It is set up.

As best shown in Fig. 2, the unit injector 1
8 consists of a nozzle part 21 and a pump part 22 which are integrated so that their axes are orthogonal to each other. The nozzle 23 of the nozzle portion 21 has its tip protruding into a combustion chamber 24 defined between the lower surface of the cylinder head 3 and the upper surface of the piston 7, and is supplied from the fuel tank 20 via a conduit 25. The fuel is directly injected into the combustion chamber 24 so that it burns by one hour. In addition, the drive side end 2 of the pump section 22
The tip of a rocker arm 26 pivotably supported within the cylinder head 3 is in contact with 2a.

Inside the cylinder head 3, as shown in FIG.
An intake valve 27 and an exhaust valve 28 as valve operating mechanisms are arranged on both sides of the unit injector 18. Both valves 27 and 28 are always biased open by coil springs 27a and 28a, and are driven by rocker arms 29 and 30 that are disposed coaxially with and adjacent to both sides of the rocker arm 26 that drives the unit injector 18. The valve is opened once.

As clearly shown in FIG. 2, a pair of baluns +
31 and 32 are rotatably supported. Both balancers 31 and 32 include a counterweight 31a,
32a is integrally and eccentrically formed, and the gears A79a, 31b, and 32b, which are fixed to the shaft end of the crankshaft 9 and the output shaft 10 side of both valances 31 and 32, mesh with each other to rotate the crankshaft. It is designed to be able to rotate at the same rotational speed as 9. These two balancers 3L and 32 are for counteracting the horizontal component of the vibration of the crankshaft 9 by rotating in opposite directions.

A camshaft 33 is pivotally supported above the balancer 32 on the right side in FIG. This camshaft 33 is gear-coupled to one of the balancers 32 so that it rotates at half the speed of the balancer 32, that is, the crankshaft 9, and the unit injector 18 and both valves 27.
Cams 34 and 35 are formed on the outer peripheral surface of the cam 28 in order to drive the cam 28 at a predetermined timing. .

The rocker arm 26 in contact with the pump section 22 of the unit injector described above is driven by one cam 34 provided on the camshaft 33 and a bushing rod 36 that engages with the cam, thereby aligning the end 22a of the pump section 22 with its axis. Press in the direction. As a result, the pump section 22 is driven, and the fuel supplied from the fuel tank 20hI is injected into the combustion chamber 24 from the nozzle 23.

On the side of the pump part 22 of the unit injector 18,
A control rack 37 is provided to protrude in a direction perpendicular to the axis. This control rack 37 has a governor rod 3 disposed in a governor rod hole 38 formed in the side wall of the cylinder block 2 and cylinder head 3.
It is connected to a governor 40 via 9. The governor 40 is a well-known type of weight governor, and is adapted to rotate together with the camshaft 33, so that the slider 40a can move in and out depending on the rotational speed of the engine. And these governors 40. The amount of fuel supplied into the combustion chamber 29 is automatically adjusted by controlling the pump section 22 through the connection of the governor rod 39 and the control rack 37. This allows the engine speed to be automatically adjusted during operation.

As shown in FIG. 3, the intake valve 27 and the exhaust valve 28
Similarly to the rocker arm 26 engaged with the unit injector 18, the rocker arm 29, 30 engaged with the unit injector 18 is connected to another bushing rod disposed parallel to the bushing rod 36 by the other cam 35 provided on the camshaft 33. Driven through. When the intake valve 27 opens, air is drawn into the cylinder 5 from the air cleaner 41 through the intake passage 42, and when the exhaust valve 28 opens, combustion gas flows into the cylinder 5.
It is discharged from the muffler 44 via the exhaust passage 43 from inside.

A predetermined amount of lubricating oil 45 is stored inside the oil pan 1, and by pumping the lubricating oil with an oil pump (not shown) during engine operation, the oil is transferred to the crankshaft 9 and the cam. ! 1133, both balancers 31 and 32, the governor 40, and each part of the valve mechanism inside the cylinder head 3 are lubricated.

FIG. 4 shows a partially cutaway view of the oil pan 1 of the engine as seen from the side of the recoil starter 13, and the following description will be made in accordance with the directions shown in the drawing.

The oil pan 1 has substantially upright front and rear walls 50a and 50b,
The left and right walls 51a, 51b whose lower parts are inclined inward and the bottom wall 52 placed approximately horizontally form a box shape with a generally trapezoidal cross section, and the opening surface 53 at the top of the box is formed by the cylinder block 2. It is ground flat to join the underside of the skirt. A housing portion for the cooling fan 12 is formed on the front side, and a joint surface for the crankcase cover 11 is formed on the rear side.

A bearing portion 5 for pivotally supporting the main journal of the crankshaft 9 is provided at the center of the opening surface 53 in the front and rear walls 50a, 50b.
4, and balancers 3L are installed on both the left and right sides of this bearing portion 54.
Thirty-two bearing portions 55 are formed.

Directly below the axis of each of these bearing parts 54, 55,
Three axial reinforcing members 56 in the shape of round rods are extended so as to integrally join the inner surfaces of the odor walls 50a and 50b. Then, in a direction perpendicular to these axial reinforcing members 56, a widthwise reinforcing member 57 in the shape of a round bar is attached to the left and right walls 5.
It extends so as to integrally connect the inner surfaces of 1a and 51b and the axial reinforcing members 56 to each other. Projections 58 are formed on the inner surfaces of the left and right walls 51a and 51b, respectively, from the opening surface 53 toward the connecting portions of the widthwise reinforcing member 57 with the inner surfaces of the left and right walls 51a and 51b.

Lubricating oil passages 56a, 57a, and 58 are located at the center of these protrusions 58 and the reinforcing members 56 and 57, respectively.
The diagonal oil passage 58a in the protrusion 58 is aligned with the oil passage (not shown) formed in the cylinder block 2, and the inside of the head cover 4 is aligned with the oil passage (not shown) formed in the cylinder block 2. is connected to. Also, the front and rear walls 50a, 5O
In b, there is an axial oil passage 5 from the bottom of each bearing part 54,55.
A vertical oil passage 59 is bored toward the front and rear ends of 6a.

An oil filter cartridge (
A mounting portion 60 (not shown) is formed. The mounting portion 60 has a two-wheel structure, with an internal thread 61a formed on the inner circumferential portion 61 communicating with the diagonal oil passage 58a, and an outer circumferential portion 62 for oil supply drilled from the rear wall 50b side. It communicates with a passage (not shown), and lubricating oil is supplied from a gear pump (not shown). Note that both the axial oil passage 56a and the width oil passage 57a are drilled from one side, but
In between, the "l" portion is closed with a plug, and each oil passage is formed as a closed circuit. Further, bolt holes 63a and 63b are drilled at appropriate positions in the upper opening surface 53 of the oil pan 1.
The oil pan 1 and the cylinder block 2 are integrally connected by screwing a bolt inserted into the cylinder block 2 from below.

Next, the flow of lubricating oil in this embodiment will be explained.

Lubricating oil sucked from the bottom of the oil pan 1 by the gear pump flows into the oil filter from the outer circumferential portion 62 of the cartridge mounting portion 60, and after being filtered, flows from the inner circumferential portion 61 into the diagonal oil passage 58a.

Here, one side directly flows upward and into the head cover 4. The other oil branches from the widthwise oil passage 57a to each axial oil passage 56a, passes through the longitudinal oil passage 59, lubricates each bearing portion 54, 55, and then flows back into the oil pan 1.

The lubricating oil that has flowed through the widthwise oil passage 57a to the left end flows into the head cover 4 via the left diagonal oil passage 58a, and flows through a separately formed return oil passage together with the lubricating oil from the right diagonal oil passage 58a. After that, it is collected in the oil pan 1.

In the oil pan in which the bearing portions 54 and 55 are integrally formed in this way, the oil pan directly receives the image of the crankshaft that is subjected to the explosion pressure. The walls 50a and 50b are easy to photograph. Therefore, according to the present invention, the intermediate portions of the front and rear walls 50a, 50b at positions as close as possible to the openings are connected by axial reinforcement +A56, and these reinforcement members 56 are connected by width direction reinforcement members 57. By doing so, deformation of the front and rear walls 50a, 50b in the axial direction is effectively suppressed.

<Effects of the Invention> As described above, according to the present invention, by interconnecting the middle parts of the wall surfaces that are particularly susceptible to vibration, integration can be enhanced and noise radiation can be reduced, which greatly contributes to making the engine quieter. It can have a powerful effect.

In addition, as shown in the above embodiment, since a lubricating oil passage can be formed inside the reinforcing material, the bearing and oil pan can be easily integrated, which is effective in simplifying the structure of the engine. It is.

Furthermore, the structure of the present invention can be expected to dramatically increase rigidity when used in combination with ribs of conventional structures.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of an engine to which the present invention is applied. FIG. 2 is a longitudinal cross-sectional view of the engine shown in FIG. 1 taken in the direction of the crankshaft. FIG. 3 is a plan view of the engine shown in FIG. 1 with the head cover removed. 4 is a partially cutaway perspective view of the oil pan of the engine shown in FIG. 1. FIG. 1... Oil pan 2... Cylinder block 3
...Cylinder head 4...Head cover 5...
Cylinder 6... Cylinder liner 7... Piston 8... Connecting rod 9... Crankshaft
9a... Gear 10... Output shaft 11... Crank case cover 12... Cooling fan 13... Recoil starter 14... Cooling fin 15... Guide plate 16...
・Fan cover 17...Passage 18...Unit injector 19...Mounting bolt 20...Fuel tank 21・
...Nozzle part 22...Pump part 22a...End part 23...Nozzle 24...Combustion chamber
25...Conduit 26...Rocker arm 27...Intake valve 28...Exhaust valve 27a, 28a...Coil spring 29.30...Rocker arm 31.32...Balun ν 31a, 32a...・Counterweight 21b, 32b
...Gear A733...Camshaft 34.35...Cam
36...Butsch rod 37...Control rack

Claims (2)

[Claims] (1) A box-shaped oil pan structure that forms part of the crankcase of an internal combustion engine and stores lubricating oil, and is formed by connecting the middle parts of opposing inner wall surfaces with a reinforcing material. The oil pan structure of an internal combustion engine is characterized by: (2) The oil pan structure for an internal combustion engine according to claim 1, wherein a lubricating oil passage is formed inside the reinforcing member.