JPH0634567Y2 - Engine cylinder head structure - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention relates to an engine cylinder head having an oil supply passage for supplying oil to a hydraulic crush adjuster (abbreviated as HLA) arranged at the upper part of the cylinder head. Regarding structure.

(Prior Art) Conventionally, as described in, for example, Japanese Patent Laid-Open No. 59-10716, an HLA is arranged above a cylinder head, and an intake / exhaust valve is driven via a swing arm supported by this HLA. Such a valve operating mechanism is known.

In this HLA, a high-pressure chamber is formed at the bottom of the casing by fitting a pivot rod with a spherical head that supports a swing arm into a casing with a bottomed cylindrical body. By pushing up the pivot rod to the swing arm side, a function is provided to replenish and supply oil to the high-pressure chamber via the check valve to always keep the valve gap at zero.

By the way, in the case of using such a valve operating device equipped with HLA, it is necessary to sufficiently deaerate the oil supplied to HLA. If air bubbles are mixed in the oil supplied to the HLA, the pivot rod will be pushed down when the cam is operating, and it will not function properly as an end pivot. Therefore, usually, an air vent hole that opens above the cylinder head is formed in the middle of the oil supply passage that supplies oil to the HLA. Also in the one described in the above publication, in addition to the defoaming chamber provided in the middle of the oil supply passage to the HLA, the air vent opening above the cylinder head is also provided at the joint part in the middle of the communication passage between the defoaming chamber and the HLA. The pores for use are drilled.

However, when an air vent hole that opens above the cylinder head is formed in the HLA oil supply passage in this way, oil jets out from the air vent hole above the head, and this scatters in the cam chamber to the intake side via the cam chamber. This causes a problem of increasing the amount of oil mist mixed in the blow-by gas introduced.

(Purpose of Invention) The present invention has been made in view of the above problems, and
The purpose is to prevent the oil ejected from the air vent hole of the oil supply passage for A from scattering and diffusing into the cam chamber.

(Structure of the Invention) The present invention is an improvement of the structure of the cylinder head part so that the oil ejected from the air vent hole of the oil supply passage for HLA returns smoothly to the oil pan without scattering. Is as follows. That is, the structure of the cylinder head part of the engine according to the present invention includes an oil supply passage for supplying oil to a hydraulic crash adjuster (HLA) arranged in the upper part of the cylinder head.
An air return hole in a cylinder head upper space in which an air vent hole that opens above the cylinder head is formed, and on the back surface of the head cover located above the air vent hole, the oil ejected from the air vent hole is divided into a plurality of parts It is characterized in that a guide rib that leads to the opening side is formed.

(Operation) A part of the oil supplied to the HLA through the oil supply passage is ejected from the air vent hole to the upper side of the cylinder head together with the air, whereby the working oil is deaerated. The jetted oil is guided by a guide rib formed on the back surface of the head cover to the side where the oil return passage is opened in the cylinder head upper space divided into a plurality of parts, and is returned as it is through the oil return passage. .

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention applied to a V-type double overhead cam type (DOHC for short) engine, and FIG. 1 is a cylinder head in the V-type DOHC engine. 2 is a rear side plan view of the cylinder head, FIG. 3 is a sectional view taken along the line III-III of FIG. 2, and FIG. 4 is a rear side bottom view of the head cover.

As shown in FIG. 1, a spark plug mounting hole 2 is formed in the center of the cylinder head 1, and a pair of intake side valve holes 3a and 3b and a pair of exhaust side are provided on both sides of the spark plug mounting hole 2. Valve hole 4
At a position where a and 4b are closer to the center than the valve holes 3a, 3b, 4a and 4b, a pair of intake sides are provided close to the spark plug mounting hole 2.
HLA insertion holes 5a, 5b and a pair of exhaust side HLA insertion holes 6a, 6b are provided. Further, at the top of the cylinder head 1, cam bearing parts 7 and 8 for intake camshaft and exhaust camshaft are formed at both side positions, and each cam bearing part 7 and 8 has a pair of bearing cap mounting parts. Bolt holes 9 are provided. The seal surface 12 that divides the intake-side cam chamber 10 and the exhaust-side cam chamber 11 is formed flush with the cap mounting surfaces of the cam bearing portions 7 and 8. An oil return passage 13 for returning oil to the oil pan is opened in the exhaust side cam chamber 11. Further, a bulge portion 14 is formed in the center of the rear side of the cylinder head 1 so as to be flush with the seal surface 12, and the bulge portion 14 is formed.
An oil chamber 15 is formed in 14 as described later in detail.

As shown in FIGS. 2 and 3, two oil galleries 16 and 17 are formed in the longitudinal direction of the cylinder head 1 at the center of the upper portion of the cylinder head 1 with the spark plug mounting hole 2 interposed therebetween. Another oil gallery on the side 18
Are formed. Of these, the two in the center 16 and 17 are H
The oil passage for LA, and the oil gallery 17 for HLA on the exhaust side is provided at a slightly higher position. Also,
The oil chamber 15 formed at the center of the top of the rear side wall of the cylinder head 1 is an oil gallery on the side of the exhaust side.
A cylinder head 1 is formed by a first communication passage 19 penetrating 18
Is connected to the oil inlet 20 at the end on the exhaust side, and is communicated to the two oil galleries 16 and 17 in the central portion by the second and third communication passages 21 and 22 opening at the bottom. Oil chamber 15
A plug 23 having an air vent hole 23a is attached to the upper opening of the. The open ends 16a, 17a, 18a of the three oil galleries 16, 17, 18 are closed by blind plugs (not shown). Oil gallery from the oil inlet 20 to the side
The lubricating oil entering 18 is supplied to the cam bearing portion 8 on the exhaust side, and the oil sent from the oil inlet 20 to the first communication passage 19 is used for the exhaust valve from the oil gallery 17 on the exhaust side in the central portion. HLA (not shown), and from the oil gallery 16 on the intake side to the HLA for the intake valve and the cam bearing portion 7 on the intake side.

The cylinder head 1 is attached in a state of being inclined toward the exhaust side with respect to the horizontal plane. However, since the oil is supplied to the cam bearing portion 8 on the exhaust side from the gallery 18 on the side portion not passing through the oil chamber 15, even if the engine is stopped and the oil supply is stopped, the oil chamber 15 and the first 2,3rd communication passage 21,2
The oil of 2 never drains completely. Therefore, HLA
Even if the sunk, the oil for recovery is secured.

Further, the oil chamber 15 has an air vent hole 23 formed in the plug 23.
Since it opens above the cylinder head 1 by a, H
A part of the oil supplied to LA is jetted above the cylinder head 1 from the air vent hole 23a together with the mixed air.

As shown in FIG. 4, double head cover seal grooves 25a, 25b are formed on the back surface of the head cover 24 so as to correspond to the seal surface 12 on the top of the cylinder head 1. Then, on the back surface of the head cover 24 located above the rear side bulging portion 14 of the cylinder head 1, a space above the oil chamber 15 is connected from the intake side cam chamber 10 by connecting the inner and outer head cover grooves 25a and 25b. A guide rib 26 is formed which is isolated and opens to the exhaust side cam chamber 11.

The oil return passage 13 opens to the exhaust side cam chamber 11, and the cylinder head 1 is attached in a state of being inclined toward the exhaust side as described above. Therefore, the oil chamber 15
The oil ejected from the air vent hole 23a of the plug 23 attached to is guided by the guide rib 26 on the back surface of the head cover 24, flows toward the oil return passage 13 provided on the exhaust side, and does not diffuse to the intake side cam chamber 10. Of course, it is smoothly discharged without scattering into the exhaust side cam chamber 11.

Although the present invention has been described in the above embodiment as applied to a V-type DOHC engine, the present invention can also be applied to various other engines having an HLA type overhead cam valve operating device. You can

The arrangement of the HLA and the structure of the HLA oil supply passage are not limited to those in the above embodiment.

(Advantages of the Invention) Since the present invention is configured as described above, it is possible to improve the return property of the oil ejected from the air vent hole of the HLA oil supply passage and suppress the diffusion to the cam chamber.

[Brief description of drawings]

1 is a rear side plan view of a cylinder head according to an embodiment of the present invention, FIG. 2 is a side view of the cylinder head, and FIG.
FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG. 4 is a rear side bottom view of the head cover in the same embodiment. 1: Cylinder head, 5a, 5b, 6a, 6b: HLA insertion hole, 13: Oil return passage, 15: Oil chamber, 16, 17, 18: Oil gallery, 19, 21, 22: Communication passage, 23: Plug, 23a: Air vent hole, 24:
Head cover, 26: rib.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Hirokazu Matsuura, 3-3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) References: Showa 63-102917 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. An air supply hole, which opens above the cylinder head, is formed in an oil supply passage for supplying oil to a hydraulic lash adjuster arranged at the upper part of the cylinder head, and a head cover located above the air discharge hole. A cylinder head structure of an engine, characterized in that a guide rib is formed on the back surface for guiding the oil ejected from the air vent to the oil return passage opening side in the cylinder head upper space divided into a plurality of parts.