JPS60173305A - Forced lubrication type cam shaft - Google Patents

Abstract

PURPOSE:To restrict or prevent occurrence of galling or wear-down and lengthen the lift of both a cam and a valve locker arm by fitting a core member into a hollow hole part, which is provided in the axial direction of a cam shaft, in order to provide a clearance between the external peripheral surface of the core member and the internal furnace of the hollow hole part. CONSTITUTION:Lubricating oil is introduced into a hole part 3 via both oil feeding hole 14 of a holder 13 and an introducing hole 6 of a cam shaft journal part 4. And it goes through a clearance S and is supplied from an oil feeding hole 8 to the surface 50 of a cam part 5, or a cam profile surface that moves by sliding with a valve locker arm. At this time, since the space volume of the clearance S is small, the lubricating oil is quickly supplied from the oil feeding hole 8 to the lubricating surface by means of centrifugal force due to rotation as soon as a cam shaft 1 starts driving, thereby shortening the lubricating oil feeding time at the time of engine start. Since the clearance S is small, even when the engine stops, the oil remains within the clearance S owing to surface tension due to viscosity of the oil. Thus, the oil is readily sent to the cam surface when the engine starts, thereby preventing galling or wear-down of the cam surface.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an improvement in a forced oil supply type power shaft used in internal combustion engines and the like.

(Prior art) Fig. 7 shows a conventional forced lubrication type force shaft (51), in which a camshaft (51) is driven by a plurality of cam parts (52) that engage and drive valve rocker arms. The journal portion (53) is rotatably supported by holders (54) and (55) located one unit below. Cam shirt) (51) has a hole (56) long in the axial direction in the center.
A lubricating oil introduction hole (57) is provided in the journal part (53).
) is provided so as to reach the inner diameter of the hole (56) from its outer periphery, while the oil supply hole (56) is provided in the upper holter (54) in the figure.
8) is provided to transfer lubricating oil between the holes (58) and (57) and introduce the oil into the hole (56).
2) The oil is introduced into the hole (57) from the oil supply hole (58) so that a part of the outer peripheral surface of the oil supply hole (58) communicates with the inner diameter of the hole (56). Through the cam part (52)
... is supplied to the surface and lubricates between the cam part (52) ... and the engaged valve rocker.

In order to form the hole of the hollow force shaft I, which looks down on the hole for the oil sump in 1 below, first of all, if it is done with cast-out rust 61f, it is necessary to prevent the bending of the core used for casting, the burning of sand, etc. There are limitations to the Nakasengetsu method, and generally holes with a diameter of 10 mm to 2 mm are used.

On the other hand, when forming the hole by machining, since the hole is long, it is extremely troublesome and difficult to drill the central oil passage with a candrill, etc., and the hole diameter is also 10 mm to 20 mm.
m.

In the hole forming by casting or machining in 1- below, the hole has a smaller diameter than the above, for example, the hole diameter is 5 mm to 8 mm.
It is extremely difficult to mold long pieces.

According to the prior art mentioned above, since the inner diameter of the hole (56) is large, the bearing part (54)
) The oil supplied from the oil supply holes (58) and (57) is once stored in the hole (56) and dispersed within the hole (56),
As the cam shirt +151) rotates, oil is sent out from inside the oil supply hole (59) and supplied to the cam surface, so oil is not quickly supplied to the cam portion of the camshaft after the engine has started, and the cam A time lag occurs between the start of rotation of the shaft and the supply of oil, which causes a dry state when the cam part and the pallet cover 1 rotate in contact with each other, and repeating this may cause galling or wear. .

(Object of the invention) The present invention has been made to improve the following disadvantages.
The purpose of this is to quickly supply lubricating oil to the cam surface when the engine starts, that is, at the same time as the camshaft starts rotating, and to prevent dry contact rotation between the cam, valve bro, and cam arm. tl/j Ll-L, To provide a forced lubrication type camshaft that suppresses the occurrence of galling and wear as much as possible, and improves the lifespan and durability of the anti-II-shi, cam, and valve rocker arm. .

(Structure of the Invention) In order to achieve the following objectives, the present invention provides a cam shirt.
・Insert the core member into the hollow hole provided in the axial direction of the
A clearance is provided between the outer circumferential surface of the middle f member and the inner circumferential surface of the hollow hole portion.

(Embodiments) Next, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an enlarged longitudinal cross-sectional side view of essential parts showing an example of a forced oil supply device including a camshaft according to the present invention, where (1) shows the camshaft, and the center of the shaft (2) of the camshaft (1). A hollow hole (3) is formed in the axial direction, and the hole (3)
is formed by casting or machining, and the inner diameter of the hole (3) is determined by the diameter of the cam shirt I.
There is no problem even if the diameter is from m+ to 20 mm or more.

The shaft part (2) of the camshaft (1) has a journal part (4
) are provided at a plurality of locations, and cam portions (5) are provided at predetermined axial intervals according to the number of cylinders and intake/exhaust valves of the engine. The journal part (4) is rotatable, for example, by a lower holder (12) protruding from the shilling hend (11), 1-, and a part holder (13) disposed above this and fixed to the head side. is hindered by

A part of the journal part (4) of the cam shirt 1-(1) has an outer peripheral surface (401') and an inner peripheral surface (3) of the hole (3).
01), a small diameter lubricating oil introduction hole (6) is bored, and the outer peripheral surface of the journal part (4) corresponding to the hole (6)
A part of the ao l) is provided with a gate structure (7) which is continuous in the circumferential direction and has a single hole and a curved part. on the other hand,
A lubricating hole (14) connecting the outer circumferential part of the I/j part holder (13) that receives the journal part (4) and the inner I/j part (131) is drilled in a part of the I part holder (13) that receives the journal part (4). The gatehouse (7)
The oil supply hole (14) supplies the pipe body (15), etc. 1. Connect to the lubricating oil supply.

A part (501) of the outer circumferential surface of the cam part (5) provided on the shaft part (2) of the cam shirt l-(+) and the inner circumference (501) of the hole part (3)
301), an oil supply hole (8) is formed so as to connect this gap, and the oil supply hole (8) is provided in each cam portion, respectively.

A core member (21) is fitted into the hole (3) of the camshaft (1) of I- below, and the outer periphery (211) of the member (21) has a circular shape, and the figure shows a hollow cylinder for widening the eaves. shape, and the member (
The outer diameter of 21) is smaller than the inner diameter of the hole (3), and an annular gap (S) is formed between the inner periphery (301) and the outer periphery (2+1).
form. This gap (S) is such that the inner diameter side of the camshaft hole of the introduction hole (6) and oil supply hole (8)...
communicate with. The middle-f member (21) includes a support portion (22) on a part of its outer periphery, which contacts the inner periphery (301) of the hole portion (3).

The figure is for convenience of explanation - The distance between the support parts (22) and (22) is short, and there are two cam parts (8), (8) and the introduction hole (6).
In practice, as shown in FIG. 3, the member (21) is provided at both ends of the member (21) in the axial direction, and the above-mentioned oil supply hole and introduction hole are exposed between them.

The support part (22) in 1- below is the outer periphery (
211) may be provided radially in a plurality on a part of the outer periphery, or may be provided in a ring shape covering the entire periphery on a part of the outer periphery. The core member is formed of a hollow tube or solid bar made of aluminum alloy, steel, synthetic resin, or the like.

Next, to explain the action in detail, by fitting the C41f member (2)) into the hole (3), the inner periphery (3 (11)) of the hole (3)
There is an annular gap (
S) is formed, and the spatial volume of this gap (S) is equal to that of the hole (3
), and the gap (S) communicates each hole (e), (8), . . . with the phase W.

? ljl lubricant is introduced into the hole (3) through the oil supply hole (I4) of the holder (13) and the introduction hole (6) of the camshaft journal part (4), and passes through the gap (S) into the oil supply hole ( 8)
... to the surface (501) of the cam portion (5), that is, the cam profile surface that slides with the valve ffl lug arm.In the case of such oil supply, the space volume of the gap (S) is small, so Lubricating oil is on the camshaft (1)
At the same time as the lubricating oil is driven, lubricating oil is quickly supplied to the sliding surface 11 from the lubricating holes (8) by the centrifugal force caused by the rotation, thereby shortening the lubricating oil refilling time when starting the engine.

In addition to the above, since the gap (S) is small, the engine stops l.
Even temporarily, oil remains in the gap (S) due to the surface tension of the oil's viscosity, and when the engine is started, the oil is immediately sent to the surface of the cam part, eliminating rotation in a dry state. ■Prevents galling and abrasion.

Next, a concrete example will be given.

Cam Shirt) 390 mm in total length, cast out using steel material FC30, and machined to form a hollow hole with an inner diameter of 15 mm. A hollow plastic member having a width r (thickness: 2 mm) was fitted into this, and a gap of 0.7rnrn was formed between the inner periphery of the hole and the outer periphery of the member.

As a result of the experiment, the conventional one with a hollow hole of 15 mm in diameter broke in about 50 hours.)? However, according to the example described in NIJ, no galling or abrasion was observed even after about 100 hours.

FIGS. 2, 4 to 6 show modified embodiments.

Figure 2 shows an example in which the member (121) is a solid bar, which is supported radially at both ends in the axial direction. B (122) was provided.

In Fig. 4, a spiral groove (223) is provided on the outer periphery of a solid bar member (221), and this groove forms a gap (S), and the gap (S) is formed by holes (B), (8), etc.・A support portion (222) was formed at the outer periphery between the grooves.

Figure 5 shows a core member (321) made of a solid bar with a small concave surface (324) provided over the entire outer periphery, and a protrusion formed into a hole (324).
3) was brought into contact with the inner periphery to serve as a support part, and the fourth part was used as a gap forming an oil passage and an oil sump.

Figure 6 shows that a small palindrome (+03) is formed on the inner circumference of the hollow part (3) of the camshaft (1), and on the other hand, the outer circumference (424) of the core member (421) is a smooth surface. , a gap oil sump is formed between them.

In the following 1-, the same reference numerals are used for the parts other than the core member, and the explanations are omitted.

(Effects of the Invention) As will be clear from the following, according to the present invention, a core member is fitted into a hole of a camshaft, and an oil passage and an oil reservoir are formed between the inner periphery of the hole and the outside of the inner cloth member. By providing a gap, the actual space volume of the oil passage can be reduced, allowing for smooth and quick supply of lubricating oil. ■The small gap allows the oil to sump even when the engine is stopped. The stored oil can be supplied to the cam section at the same time as the engine starts, thereby preventing galling and abrasion of the camshaft cam section, greatly improving ff life and durability.

In addition, a hollow hole portion of a normal diameter is formed in the camshaft,
It can be molded with a simple structure in which a middle member is fitted into this, and it is easy to manufacture, and the desired 1-1 structure can be achieved at low cost without any difficulty.

[Brief explanation of drawings]

FIG. 1 is an enlarged longitudinal sectional side view of the main part showing an embodiment of the present invention;
FIGS. 2 to 6 are explanatory diagrams showing each embodiment of the core member,
FIG. 7 is a diagram similar to FIG. 1 of the conventional example. In the drawing, (1) is the camshaft, (4) is the bearing, and (5) is the camshaft.
) is the cam part, (8), (8), (14) are the small holes for oil supply, (3) is the hollow hole part, (21), (12+), (2
21) , (321), (421) are core members, (S)
is a gap. Patent applicant Honda Motor Co., Ltd. Agent Patent attorney 2 1) Yōichi division Patent attorney Kuni Hiko Ohashi Patent attorney Yu Koyama Figure 1 Figure 7

Claims (1)

[Claims] A hollow hole is formed in the axial direction, and small holes are provided in the bearing and cam parts in the radial direction to connect the holes and the respective surfaces, oil is supplied from the bearing, and small holes are formed on the surface of the cam. In a forced lubrication type camshaft that supplies lubricating oil, 111
A forced lubrication type in which a medium member with a smaller diameter is inserted into the hollow hole described in 1 above, and a gap is provided between the outer periphery of the medium member and the inner periphery of the hollow hole, which is the 4'F feature. camshaft.