JPS6237923Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an engine camshaft device which is based on integrally assembling a camshaft into a cylinder head cover, and which can improve assembly efficiency and reduce the size and weight of the engine.

In recent years, in order to absorb the thermal expansion of the valve mechanism between the valve stem and rocker arm, for example, a hydraulic lash adjuster is used to eliminate the valve clearance, which allows the valve to open and close correctly, and also reduces noise, uneven wear, etc. Efforts are being made to prevent this. On the other hand, this latch adjuster usually has a spherical head plunger, and is configured so that the rocker arm is pivotally supported by the ball head.Therefore, when using the latch adjuster, the rocker arm is simply placed on its upper end. This simplifies the installation process. In addition, in conventional camshaft devices that do not have an automatic valve clearance adjustment mechanism, the cylinder head cover needs to be easily removable for checking, adjusting, and maintaining the valve clearance. It was impossible to integrate it into the cylinder head cover. On the other hand, in the cam device using the lash adjuster, the cam bearing is provided either integrally with the cylinder head or separately, and the cylinder head cover is provided on top of the cam bearing, so that the advantages of using the lash adjuster are not fully utilized. It was not something that was put to good use. Furthermore, when the cam bearing portion is formed in half, problems such as difficulty in sealing the protruding end of the camshaft also arise.

This invention was devised to simplify assembly and maximize the functionality of the cylinder head cover, focusing on the fact that the use of a latch adjuster eliminates the need for valve clearance adjustment. The purpose of the present invention is to provide an engine camshaft device that can reduce assembly man-hours, the number of parts, and machining parts by integrally incorporating the camshaft into the cylinder head cover, as well as reduce the size and weight of the engine. One embodiment will be described in detail with reference to the drawings.

1 and 2, the engine camshaft device 1 of the present invention is a cylinder in which a valve stem guide 3 of an intake or exhaust valve stem 2 and a mounting hole 5 of a lash adjuster 4 are provided substantially perpendicularly. A cylinder head cover 10 with a camshaft 9 integrated therein is fixed to the head 6 using bolts 14. Holds a dynamic fulcrum. The cylinder head 6 is
Water jackets 12 are perforated at key points, and flange portions 13 facing outward at the upper end are provided.
a positioning bush 15 through which the bolt 14 is inserted;
is installed, and the cylinder head cover 10 can be properly aligned and installed via the positioning bush 15. The latch adjuster 4 has a well-known hydraulic construction, and the mounting hole 5 of the cylinder head 6 has an oil hole 16 that opens at the center and communicates with an oil pump (not shown), and an oil relief hole 17 at the lower end. The spherical plunger 4a can be urged upward with a predetermined pressure and moved by pressurized oil into the central oil hole 16. The rocker arm 7 has the spherical plunger 4a in a recess 19 formed at its base.
The ball head of the valve stem is supported by being loosely fitted, and the other end is in contact with the upper end of the valve stem 2 and also in sliding contact with the cam 11 via the sliding plate 20 on the upper surface,
The rotation of the camshaft 9 allows the valve stem 2 to be pushed down against the valve spring 21. The cylinder head cover 10 is, for example, a cast product, and has a main chamber 2 that accommodates the camshaft 9 with a vertical wall 23 that hangs down in the longitudinal direction.
5 and an oil separator chamber 26 located above the lash adjuster 4, and a main chamber 2.
The camshaft 9 is integrally pivotally connected by a journal 30 provided on the horizontal wall 27 perpendicular to the longitudinal direction and the front wall 29 of the main chamber. Note that the pivot portion of the camshaft 9 at the journal 30 is provided with a circumferential groove 31 for oil passage, and the radius thereof is set to the maximum radial distance of the cam flank or a dimension that allows for a slight tolerance thereto. As a result, the camshaft 9 can be inserted from the front a of the cylinder head cover 10, and is appropriately prevented from coming off. Further, the cylinder head cover 10 has an oil hole 3 having an injection hole 33 facing the cam 11 at the corner of the upper wall thereof.
5 is opened, and a delivery pipe 36 is provided on the outer surface to branch and communicate with the circumferential groove 31 of the journal 30. It goes without saying that instead of the delivery pipe 36, an oil hole communicating with the oil hole 35 may be provided in the block. The oil separator chamber 26 is provided with an outlet 45 that passes through the inside and outside of the cylinder head cover 10, and has an outer periphery made of rubber between nuts 39, which are screwed onto a mounting bolt 37 hanging from the upper end of the outlet 45. A partition plate 41 having a rectangular elastic piece 40 is held, and both sides of the partition plate 41 are in contact with the side wall and the vertical wall 23, and the front and rear ends of the partition plate 41 are attached with a small gap g between them. Accordingly, the oil mist flowing into the oil separator chamber 26 through the small gap g can be separated into gas and liquid.

However, in the engine camshaft device 1 of the present invention, the valve stem 2 can be raised and lowered as the camshaft 9 rotates, and various parts can be lubricated through the oil holes 16 and 35, and the lash adjuster 4 can be operated. Since the camshaft 9 is integrated into the cylinder head cover 10, during assembly, the recess 19 of the rocker arm 7 is inserted onto the ball head plunger 4a of the lash adjuster 4 pre-attached to the cylinder head 6. After placing the other end on the upper end of the valve stem 2, attach the cylinder head cover 10.
Installation can be completed simply by tightening using the positioning bush 15 and bolt 14, and the valve clearance is automatically adjusted by the latch adjuster 4 without requiring manual adjustment. Further, as the camshaft 9 rotates, oil mist mixed into the blow-by gas and other gases can be separated into gas and liquid in the oil separator chamber 26, and the liquefied oil is refluxed. Note that the blow-by gas flows through the outlet 45 into a well-known air flow path of an engine such as an air cleaner (not shown).

As mentioned above, the engine camshaft device of the present invention has a rocker arm that is supported by a latch adjuster, so there is no need to adjust the valve clearance after assembly, and the camshaft is integrated with the cylinder head cover. Because it is built-in, assembly is extremely simplified and the number of man-hours is reduced. At the same time, the number of parts and machining costs are reduced compared to the conventional case in which the camshaft is pivoted using a journal cap on the cylinder head. The height of the cylinder head itself can be significantly reduced compared to when the cylinder head is assembled into a cylinder head, thereby making the engine more compact and lightweight as a whole. Furthermore, since the camshaft is integrated into the cylinder head cover, there is no need to seal at the split surface or the mating surface, and the shaft sealing effect can be ensured. Furthermore, by providing the oil separator chamber adjacent to the main chamber that accommodates the camshaft, the overall height of the engine can be further reduced. In addition, the oil separator chamber is separated by a vertical wall from operating parts that generate a lot of oil mist, such as the camshaft, rocker arm, and valve stem, and is located above the lash adjuster, where less oil mist is generated, so that oil retention is reduced. It is obvious that the oil separator can be made smaller and the oil separator can be made smaller.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is an enlarged partial view of the camshaft, and Figure 3 is A-
A sectional view taken along line A, and FIG. 4 is a perspective view of the cylinder head cover viewed from below. 2...Valve stem, 4...Lash adjuster, 6...Cylinder head, 7...Rocker arm, 9...Cam shaft, 10...Cylinder head cover, 11...Cam, 23...Vertical wall, 25 ...Main room, 26...Oil separator room.

Claims (1)

[Scope of utility model registration request] A cylinder head is provided with a valve stem and a latch adjuster that holds a rocker arm that abuts the upper end of the valve stem at a swing fulcrum, and
A cylinder head cover that is combined with the cylinder head and covers the cylinder head is provided with a vertical wall extending in the longitudinal direction to form a main chamber, and an oil separator chamber having an outlet and capable of separating internal oil. On the other hand, a cam extending in the longitudinal direction is provided in the main chamber, and a cam shaft with one end protruding outside is integrally incorporated, and the cylinder head cover is aligned with the cylinder head in the longitudinal direction and is attached to the rocker arm. A camshaft device for an engine, which is assembled to a cylinder head by bringing the cam into sliding contact with the cam and by positioning the oil separator chamber above the lash adjuster.