JPH07243315A - Lubricating device for timing chain in internal combustion engine - Google Patents

Abstract

PURPOSE:To improve lubricating property by forming a fine clearance between the cover plate of a cover case inner surface and an inner rotor, and discharging a part of lubricating oil to the position formed in the vicinity of an engaging start position in relation to the sprocket of a timing chain while passing the fine clearance by a pump. CONSTITUTION:A discharging chamber 10g in the cover plate 10e of a lubricating oil pump 10 is arranged on an upper position from a crank shaft end part 2a, and a fine clearance 12 is provided between the cover plate 10e and an inner rotor 10c so as to communicate the discharging chamber 10e and the position formed in the vicinity of engaging start position in relation to the sprocket 8 of a timing chain 4 with each other. Lubricating oil in an oil pan 6 is sucked by the lubricating pump 10 which is interlocked to the crank shaft 2, and it is discharged from a discharging passage to a main lubricating oil passage in the cylinder block 1 by high pressure, and also a part of high pressure lubricating oil in the discharging chamber 10g is ejected from the fine clearance 12, and oiling is carried out to the engaging start position in relation to the sprocket 8 of the timing chain 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine, in which the rotation of the crankshaft is applied to either or both of an intake valve camshaft and an exhaust valve camshaft, or to a fuel injection pump or the like. In the case of transmission via a timing chain, the present invention relates to a lubricating device for the timing chain.

[0002]

2. Description of the Related Art Conventionally, lubrication for a timing chain has been disclosed, for example, in Japanese Utility Model Publication No. 63-
As described in Japanese Unexamined Patent Publication No. 98419, the lubricating oil from the lubricating oil driven by the internal combustion engine is directly sprayed onto the timing chain by jetting from an oil jet. .

However, in the structure in which the lubricating oil is sprayed from the oil jet to the timing chain as described above, in addition to the need for the oil jet, the oil jet is used as a cylinder block. Or, parts such as bolts for attaching to the cover case covering the timing chain are required, and not only the number of parts is large, but also the cylinder block or the cover case is provided with the lubricating oil from the lubricating oil pump. A lubricating oil passage for guiding the oil jet must be formed. In other words, the number of parts, the number of assembling steps, and the number of processing steps increase. There is a problem that not only the size is significantly increased, but also the size is increased.

Moreover, the nozzle hole diameter in the oil jet must be relatively large so that the supply of the lubricating oil to the timing chain can be ensured even in the low rotation speed region. Therefore, in the low rotation speed region, the lubricating oil pump is required. There is also a problem that the proportion of the lubricating oil ejected from the oil jet in the lubricating oil from the engine increases, and the lubricating oil supplied to various operating parts of the internal combustion engine is insufficient by that much.

According to the present invention, in a recent internal combustion engine, as described in JP-A-5-59924 and JP-A-5-33688, a lubricating oil pump and a crankshaft cover a timing chain. Focusing on the point that it is proposed to support the cover case at a position penetrating the cover case, this is utilized to ensure the timing chain without causing the above-mentioned problems. It is a technical object to provide a device that can be lubricated.

[0006]

SUMMARY OF THE INVENTION To achieve this technical object, the present invention provides, on one side of a cylinder block, winding between a sprocket on a crankshaft and a sprocket on a camshaft or a fuel injection pump shaft. A cover case for covering the hung timing chain is joined, a pump casing of the lubricating oil pump is provided in a portion of the cover case through which the crankshaft penetrates, and an inner rotor fitted to the crankshaft and the casing are provided in the casing. An inner rotor and an outer rotor are inserted from the inside of the cover case, and further, on the inner surface of the cover case, a flat cover plate is attached so as to cover the pump casing with the cover plate, Discharge chambers for the inner rotor and the outer rotor are located above the crankshaft. On the other hand, a minute gap is provided between the cover plate and the inner rotor so as to communicate the discharge chamber with a portion near the start of meshing of the timing chain with the sprocket when viewed in the axial direction of the crankshaft. "."

[0007]

[Operation] By configuring in this way, part of the high-pressure lubricating oil in the discharge chamber of the lubricating oil pump can be ejected through the minute gap to a location near the start of meshing of the timing chain with the sprocket. It is possible to reliably supply the lubricating oil to the position where the timing chain starts to mesh with the sprocket without providing an oil jet and a lubricating oil passage for the same as in the conventional case.

The pressure of the lubricating oil in the discharge chamber increases in proportion to the number of revolutions of the internal combustion engine. When the pressure of the lubricating oil in the discharge chamber increases, the pressure causes the flat lid plate to move. , The minute gap is deformed so as to become large, in other words, the minute gap automatically increases in proportion to the number of revolutions of the internal combustion engine, so that the lubricating oil from the minute gap becomes large. It is possible to restrict the jetting amount of the fuel to a very small amount in the low rotation speed region, and thereafter increase it in proportion to the rotation speed.

[0009]

As described above, according to the present invention, the cost required to lubricate the timing chain can be greatly reduced, and the size and weight can be reduced, and moreover, the ejection to the timing chain from the minute gap is possible. Since the amount of lubricating oil to be controlled can be regulated to an extremely small amount in the low rotation range, the lubricating oil can be sufficiently supplied to the timing chain in the high rotation range, but in the low rotation range, There is an effect that it is possible to surely prevent the supply amount of the lubricating oil from becoming insufficient to various operating parts of the internal combustion engine.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings of FIGS. In this figure, reference numeral 1 indicates a cylinder block, and reference numeral 2 indicates a crankshaft pivotally supported by a bearing portion 3 in the cylinder block 1. One side surface 1a of the cylinder block 1 includes a timing chain 4 which will be described later. The cover case 5 that covers the entire
The cover case 5 and the cylinder block 1 are detachably joined by a plurality of bolts (not shown).
An oil pan 6 is joined to the lower part of the.

The shaft end 2a of the crankshaft 2 is
While penetrating the side plate 5a of the cover case 5 and projecting to the outside thereof, a power transmission pulley 7 for an engine accessory such as a cooling water pump (not shown) is fitted to the projecting end while the shaft end 2a is provided. A sprocket 8 is fitted into a portion inside the cover case 5, and the timing chain 4 for transmitting power to a cam shaft (not shown) is wound around the sprocket 8.

Further, a recess 9 is provided on the side surface of the power transmission pulley 7 on the cover case 5 side, and the lubricating oil pump 10 provided on the side plate 5a of the cover case 5 is arranged in the recess 9. Set up. This lubricating oil pump 10
The side plate 5a of the cover case 5 extends from the recess 9
Pump casing 10a integrally molded inward
In the pump casing 10a, the outer rotor 10b inserted from the cover case 5 and the inner rotor 10 fitted to the shaft end 2a of the crankshaft 2.
c and the inner surface of the side plate 5a of the cover case 5 so as to cover the entire pump casing 10a,
It is composed of a flat cover plate 10e detachably attached by a plurality of bolts 10d arranged around the periphery.

The outer rotor 1 is attached to the pump casing 10a and the cover plate 10e of the lubricating oil pump 10.
0b and the suction chamber 10f for the inner rotor 10c
And a discharge chamber 10g are formed, and the lid plate 10e further includes a suction passage 10 communicating with the suction chamber 10f.
h and a discharge passage 10i communicating with the discharge chamber 10g are formed, and the lubricating suction pipe line 11 from the oil pan 6 is connected to the suction passage 10h,
The discharge passage 10i is connected to a main lubricating oil passage (not shown) in the cylinder block 1.

The lid plate 10 of the lubricating oil pump 10
The discharge chamber 10g of the crankshaft 2e is disposed above the shaft end 2a of the crank 2, while a minute gap 12 is formed between the cover plate 10e and the inner rotor 10c. It is provided so as to communicate with the portion of the timing chain 4 in the vicinity of the start of meshing with the sprocket 8 when viewed in the axial direction.

In this configuration, the lubricating oil pump 10 sucks the lubricating oil in the oil pan 6 by the rotation of the crankshaft 2 accompanying the start of the internal combustion engine, and then the discharge passage 1 thereof.
0i is sent to the main lubricating oil passage 12 in the cylinder block 1 at high pressure. in this case,
A part of the high-pressure lubricating oil in the discharge chamber 10g of the lubricating oil pump 10 is jetted through the minute gap 12 to a portion in the vicinity of the start of meshing of the timing chain 4 with the sprocket 8 to thereby sprockets the timing chain 4. It is possible to reliably supply the lubricating oil to the position where the meshing with 8 starts.

The pressure of the lubricating oil in the discharge chamber 10g increases in proportion to the number of revolutions of the internal combustion engine. When the pressure of the lubricating oil in the discharge chamber 10g increases, this pressure causes a flat lid. The plate 10e is deformed so that the minute gap 12 becomes large,
In other words, the minute gap 12 automatically increases in proportion to the number of revolutions of the internal combustion engine, so that the amount of lubricating oil ejected from the minute gap 12 becomes extremely small in the low rotation speed region. While it can be regulated, it can be increased in proportion to the number of revolutions thereafter.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

[Explanation of symbols]

 1 Cylinder Block 1a One Side of Cylinder Block 2 Crankshaft 2a Crankshaft Shaft End 4 Timing Chain 5 Cover Case 6 Oil Pan 10 Lubricating Oil Pump 10a Pump Casing 10b Outer Rotor 10c Inner Rotor 10e Lid Plate 10f Suction Chamber 10g Discharge Chamber 12 Minutes Gap

Claims (1)

[Claims] 1. A cover case, which covers a timing chain wound between a sprocket on a crank shaft and a sprocket on a cam shaft or a fuel injection pump shaft, is joined to one side surface of a cylinder block. In the portion where the crankshaft penetrates, a pump casing of a lubricating oil pump is provided, and in this casing, an inner rotor fitted to the crankshaft and an outer rotor for the inner rotor are inserted from the inside of the cover case,
Further, in an internal combustion engine in which a flat lid plate is attached to an inner surface of the cover case so as to cover the pump casing with the lid plate, a discharge chamber for the inner rotor and the outer rotor is provided above the crankshaft. On the other hand, a minute gap is formed between the cover plate and the inner rotor so that the discharge chamber communicates with a portion near the start of meshing of the timing chain with the sprocket when viewed from the axial direction of the crankshaft. A timing chain lubricating device in an internal combustion engine, characterized in that