JPS5916490Y2 - Camshaft bearing device in internal combustion engine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for pivotally supporting a camshaft for opening and closing an intake valve or an exhaust valve in an internal combustion engine.
Specifically, when a thrust receiver is provided on the camshaft to support the thrust load on the camshaft, the camshaft is prevented from moving in the thrust direction due to the lubricating oil pressure associated with the thrust receiver and causing collision noise. The purpose is to

Next, an example of the present invention will be explained with reference to a drawing. In the drawing, 1 is the cylinder head of the engine, 2 is the crankshaft of the engine (
(not shown) are shown, and the cylinder head 1 has a bearing hole 3. 4. 5 are integrally provided, and the camshaft 2 is connected to the bearing portion 3.5. 4. 5
The shaft portion 6 is provided at a position corresponding to 6. 7. 8 is each bearing portion 3. 4. It fits into the hole 5 and is rotatably and slidably supported.

The shaft portion 6 at one end of the camshaft 2 is integrally provided with a thrust receiver 10 that contacts the thrust receiving surface 9 on the outer surface of the bearing portion 3, and the end protruding from the bearing portion 3 is provided with a thrust receiver (Fig. (not shown) and an end cam 12 for transmitting power.

A housing 13 is attached to the outer surface of the bearing portion 3 to cover the helical gear 11 and the end cam 12, and a fuel pump 15 is connected to the end cam 12 via a rod 14 at the outer end of the housing 13. A cylindrical thrust receiver 16 is integrally attached to the inner end of the housing 13 and faces the outer surface of the thrust receiver 10 with an appropriate thrust clearance.

The thrust receiving surface 9 in the bearing part 3 and the cylindrical thrust I/receptor 16 in the housing 13 are provided with a lubricating oil on the sliding surface between the thrust receiving surface 9 and the thrust receiving surface 10 to escape into the housing 13. Groove 17. j8 is provided.

Note that the reference numeral 19 in the figure indicates an undercut groove.

In the camshaft equipped with the thrust receiver 10 in this way,
The sliding surface between the thrust receiver 10 and the thrust receiver surface 9 is lubricated by lubricating oil pressure-injected into the oil groove 20 of the bearing part 3. On the other hand, the thrust receiver [O] receives a reaction force in the power transmission of the gear 11 in the same direction as the lubricating oil pressure, and a driving reaction force of the fuel pump 15 acts in the same direction as the lubricating oil pressure. In this case, when the thrust receiving surfaces 9 and 16 do not have the oil relief grooves 17 and 18 as in the conventional case, the thrust receiver 10 receives the lubricating oil pressure and the power of the screw gear 11. The thrust receiving surface 16 separates from the thrust receiving surface 9 due to the transmitted reaction force.
As the thrust receiver 10 moves away from the thrust receiving surface 9, the lubricating oil pressure decreases, so the thrust receiver 10 is pressed so as to contact the thrust receiving surface 9 by the driving reaction force of the fuel pump 15. By repeating the operation, it slides back and forth between the thrust receiving surface 9 and the thrust receiving surface 9 and the thrust receiving surface 16, and when it is struck against the thrust receiving surface 9 and the thrust receiving surface 16, not only does it generate a collision sound, but also this reciprocating sliding As a result, the ignition timing of the distributor to which power is transmitted from the helical gear 11 changes.

In contrast, in the present invention, grooves 17 and 18 are provided in the thrust receiving surface 9 and the thrust receiving body 16 to release lubricating oil on the sliding surface between the thrust receiving surface 9 and the thrust receiving tube 10. The lubricating oil on the sliding surface between the surface 9 and the thrust receiver 10 gradually escapes into the housing 13 through the grooves 17 and 18, and no pressure is applied to the housing 13.
(3) The lubricating oil that escaped inside the housing accumulates to some extent in the housing and lubricates the helical gear 11, etc., then overflows from the hole 21 provided on the side and returns to the engine crankcase or the upper surface of the cylinder head), the thrust receiver 10 is kept in constant contact with the thrust receiving surface 9 by the driving reaction force of the fuel pump 15 without separating from the thrust receiving surface 9.

In this case, as a means for releasing the lubricating oil on the sliding surface between the thrust receiving surface and the receiving cylinder, a hole 22 may be provided in the thrust receiving cylinder 10 as shown in FIG.
It goes without saying that these holes 22 or grooves 17 and 18 may be provided at multiple locations around the circumference.

Therefore, according to the present invention, since it is possible to prevent the camshaft 5 from sliding back and forth using the lubricating oil pressure, not only is there no collision noise caused by the sliding, but there is also no fluctuation in the ignition timing in the pistol repeater. It has the effect of not causing

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of an embodiment of the device of the present invention, Fig. 2 is an enlarged view of the main part of Fig. 1, Fig. 3 is a sectional view taken along line III-III of Fig. 2, and Fig. 4 is another example of the present invention. FIG. 3 is a diagram of an example device. 1... Cylinder head, 2... Camshaft, 3. 4.
5... Bearing part, 6.7.8... Shaft part, 9... Thrust receiving surface, 10... Thrust receiver, 13... Housing, 16... Thrust receiver, 17. 18...groove, 22...hole.

Claims (1)

[Scope of utility model registration request] A thrust receiver provided on a camshaft is in contact with a thrust receiver surface for the camshaft, and the thrust receiver or thrust receiver surface is provided with lubricating oil at the sliding portion between the thrust receiver and the thrust receiver surface. A bearing device for a camshaft in an internal combustion engine, which is provided with a hole or groove for escape from the sliding part.