JPS621419Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a structure related to lubrication of a distributor drive gear of an internal combustion engine.

[Conventional technology]

In an overhead camshaft type engine, when the camshaft drives the distributor, the camshaft 1 is equipped with a drive gear 2 as shown in Fig. 1, and the distributor is operated by meshing with gear 3 on the distributor side. - This gear drives a shaft connected to the rotor of the motor, and this gear requires lubrication. In the case of an overhead camshaft type engine, conventionally, this part was lubricated by providing an oil jet hole 5 in a special fixed part such as the oil delivery pipe 4, and jetting oil from this oil jet hole 5. This is done by applying it to the tooth surface of the drive gear 2. Therefore, when using the conventional method, it is always necessary to provide special parts such as an oil delivery pipe, which poses the problem of increasing space and cost.

The technical background why the prior art had to adopt the above structure will be explained.

Since the camshaft is manufactured integrally with the cam, it is made of a cast product, and there was no thought to make the camshaft from iron pipe. For example, Japanese Patent Application Laid-Open No. 51-105540 discloses that the shaft of a power distribution device is made of a pipe, but does not disclose that the camshaft itself is made of an iron pipe.

There was an idea to provide an oil passage in a cast camshaft to lubricate the sliding parts between the cam and the valve, but when providing an oil passage in a cast camshaft, the hole for the oil passage had to be drilled. (For example, Japanese Utility Model Application No. 53-88637, and although it is not a camshaft, Japanese Utility Model Application Publication No. 51-3729). This drilled hole was formed to a diameter of about 8 mm at most in order to transmit oil pressure through the camshaft within the oil passage and to jet oil at an appropriate pressure from the cam lubrication hole. On the other hand, if the camshaft is made of iron pipe, the wall thickness of the iron pipe will inevitably be thinner due to manufacturing reasons, and the inner diameter will be 10 to 12 mm or more, so the cross-sectional area of the hole will be smaller than that of a hole made with a drill. The centrifugal force of the oil becomes large, and it is difficult to imagine that the oil pressure will be transmitted from the oil supply section through the pipe, so it is unthinkable to use the space inside the iron pipe as an oil passage. It was beyond my reach. For example, Japanese Utility Model Application Publication No. 51-3729 proposes that a groove is cut on the outer periphery of the distributor shaft to forcibly supply oil through the rotation of the groove, even when oil is supplied to the distributor drive gear through an oil passage formed by drilling. A forced feeding method is adopted.

Also, although there was an idea to supply oil to the distributor gear through the inside of the distributor shaft (for example, Publication of Utility Model Publication No. 39-16263),
There was no concept of supplying oil to the distributor through the inside of the camshaft, and furthermore, there was no idea of supplying oil to the distributor drive gear through a camshaft made of iron pipe.

Due to these circumstances, the conventional structure had to adopt a structure in which oil is sprayed from a pipe that does not rotate and therefore does not generate centrifugal force, as shown in FIG.

[Problem that the invention attempts to solve]

However, installing special parts such as the oil delivery pipe (see Figure 1) is difficult to install in the limited space for installing the camshaft, and therefore requires a large space and increases the size of the engine. This naturally leads to problems such as increased cost and weight.

Also, as mentioned above, there was no idea of using the camshaft as an oil passage for the distributor, but even if it were to be used, the camshaft was conventionally a cast product, so there was no need to go to the trouble of drilling holes. The machining costs are high and there is no advantage compared to drilling holes in the distributor shaft, and even if an oil passage is formed in a cast camshaft, it is not possible to transmit enough oil pressure to blow out the oil. (As mentioned above,
There were problems such as the fact that it was thought that it would be impossible with a large diameter hole, so it was not given any consideration.

[Means for solving problems]

In order to achieve the above object, the distributor drive gear lubrication device according to the present invention has a camshaft made of an iron pipe with an oil passage inside, and the oil in the oil passage is supplied to a position near the distributor drive gear of the camshaft. An oil jet hole for spouting the oil is drilled, and the oil passage is routed from the oil pan formed in the bearing part of the camshaft housing that supports the camshaft, through the oil pump, and further through the main gear of the cylinder block to the cylinder head. An oil hole that guides the lubricating oil that has risen to the oil passage,
It consists of a steel pipe camshaft that is connected to allow communication in accordance with the rotation of the camshaft.

[Effect]

In developing the above device of the present invention, various considerations were made.

First, is it possible to make the camshaft from an iron pipe instead of the conventional cast shaft? In that case, the cam would naturally have to be formed by sintering or the like and be integrated with the iron pipe. The question is whether such technology is possible. Although the idea of making a camshaft from an iron pipe was not previously known, it was found that it is possible based on the technology possessed by the present inventor.

If the camshaft is made of iron pipe, no special drilling is required to form an oil passage inside the camshaft, and if the space can be used as it is as an oil passage, processing costs can be reduced. Furthermore, since there is no need to provide a special oil delivery pipe like in the past, space, cost, and weight can be reduced, and these advantages are enormous.

Whether the space inside the iron pipe camshaft can be used as an oil passage depends on whether the pressure can be sufficiently transmitted against the centrifugal force of the oil inside the camshaft, even if the inside diameter is larger than the drilled hole in the cast shaft. must be considered. If the camshaft is constructed from iron pipes, the inner diameter of the camshaft will be approximately 10mm or more, but if it is connected to a main gear rally whose pressure is increased by an oil pump, sufficient pressure can be maintained even within the iron pipes when communicating. Divided.

Based on these findings, the above-mentioned present invention was completed. Therefore, in the present invention, (i) the camshaft is an iron pipe, (ii) the oil jet hole is bored near the distributor drive gear, and (iii) the oil pump is installed inside the iron pipe. It is necessary to be able to communicate with the main gear rally through which the pressurized oil flows, and in addition, with the above device, special equipment such as a delivery pipe is not required, and space and cost can be reduced. This method provides a number of advantages, such as the use of iron pipes, which eliminates the need for special drilling to form oil passages, and the reduction of processing costs.

〔Example〕

Hereinafter, preferred embodiments of the distributor drive gear lubrication device according to the present invention will be described with reference to the drawings.

FIGS. 2 and 3 show the apparatus of this embodiment. In the figure, a camshaft 11 is made of an iron pipe, and an oil passage 12 is formed inside the iron pipe. Oil is supplied to the oil passage 12 by supplying the lubricating oil that has come up from the engine oil pan to the cylinder head through the main gear rally of the cylinder block to the bearing part of the camshaft housing that supports the camshaft 11. This is accomplished by forming an oil hole leading to the camshaft 11 and communicating this with a through hole formed in the camshaft 11 as the camshaft rotates. However, the communication area can be appropriately set by selecting the circumferential length of the groove provided in the bearing portion.

On the outer circumference of the camshaft 11, there is a distribution bar.
The drive gear 13 is connected to the drive gear 13, and by meshing the drive gear 13 with a gear 14 on the distributor side, the distributor is rotated. An oil jet hole 15 extending radially through the wall of the camshaft 11 is provided at a position near the drive gear 13 of the camshaft 11, and oil is jetted through the hole 15. It is desirable that this oil jet hole 15 be formed on the side corresponding to the meshing side when viewed from the direction of engagement and rotation between the drive gear 13 and the gear 14 on the distributor side. However, there is no particular problem even if the hole is drilled on the side opposite to the biting side. This hole 15 usually consists of a counterbore and a small hole penetrating from its bottom to the oil passage 12, but it may also be a straight hole.

In the apparatus constructed as described above, lubrication of the distributor drive gear is achieved as follows. In other words, the oil sent to the oil passage 12 in the camshaft 11 is under pressure (this pressure is 2 to 3
Kg/cm ² or more, which is greater than the pressure due to the centrifugal force of the oil in the camshaft, so the oil pressure can be sufficiently transmitted to the oil passage in the camshaft), and the centrifugal force exerted on the oil by the rotation of the camshaft 11. The force causes the oil to be jetted out through the oil jet hole 15 and applied to the gear 14 on the distributor side near the oil jet hole 15. In this case, since oil is applied to the meshing side of the gear 14, the gear 14 will mesh with the distributor drive gear 13 immediately after oil is applied, and a sufficient amount of oil will be supplied to the meshing part of the gears to ensure smooth operation. Lubrication is achieved. In this case, the engine speed increases and the camshaft 1
1 and the gears 13 and 14, a correspondingly large amount of lubrication is required, but in addition to the fact that the pumping pressure of the oil pump increases in accordance with the engine speed,
Since the rotation of the camshaft 11 increases and the centrifugal force also increases, the combined effect of the two causes a larger amount of oil to be ejected from the oil jet hole 15 to lubricate the gear meshing portion, providing ideal lubrication.

[Effect of idea]

Therefore, when using the distributor drive gear lubrication device of the present invention, there is no need to provide a special device such as an oil delivery pipe as in the past, and lubrication can be achieved with a simple structure.
This is advantageous in terms of space, cost reduction, and practicality.

In addition, since the camshaft is made of iron pipe, there is no need to specially drill the oil passage, which reduces costs after machining.

Furthermore, since the oil passage within the iron pipe can be communicated with the main gear rally, the necessary pressure path can be expanded.

Furthermore, if the oil jet hole is provided at a position on the camshaft corresponding to the meshing side of the gear, a sufficiently large amount of oil can be effectively supplied to the gear meshing portion.

[Brief explanation of the drawing]

FIG. 1 is a partial front view of a conventional distributor drive gear lubrication system, FIG. 2 is a front view showing a cross section of a camshaft of a distributor drive gear lubrication system according to an embodiment of the present invention, and FIG. The figure is a side view of FIG. 2. The meanings of the symbols in the figure are as follows. 11...
...Camshaft, 12...Oil passage, 13...
Distributor drive gear, 14... Distributor side gear, 15... Oil jet hole.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A camshaft is constructed of an iron pipe with an oil passage inside, and an oil jet hole is bored in the camshaft near a distributor drive gear for spouting oil from the oil passage. The oil passage is formed in the bearing part of the camshaft housing that supports the camshaft, and carries the lubricating oil that has flowed from the oil pan, through the oil pump, and further through the main gear rally of the cylinder block to the cylinder head. A distributor drive gear lubricating device characterized by being connected to an oil hole leading to a passage so as to be able to communicate with the rotation of an iron pipe camshaft. (2) Connect the oil jet hole to the distributor.
2. The distributor drive gear lubricating device according to claim 1, which is bored in a camshaft wall corresponding to the meshing side between the distributor gear and the distributor drive gear.