JPH0128251Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an intake and exhaust valve mechanism for a variable cylinder engine, and particularly to an improved mechanism for supplying oil to a rocker arm.

In recent years, variable cylinder engines have been developed due to the demand for energy conservation. This variable cylinder engine achieves improved fuel efficiency by cutting off fuel supply to a predetermined cylinder during low load and continuing operation with the remaining cylinders.

The above-mentioned variable cylinder engine has cylinders that are stopped (hereinafter referred to as
It's called a "stopped cylinder." ) and cylinders that are constantly operated (hereinafter referred to as "operating cylinders").

FIG. 1 shows the general structure of an intake and exhaust valve mechanism provided in a stopped cylinder. To explain this in detail, the rocker arm 4 is reciprocated around the rocker shaft 3 by the valve driving force of the rotated cam 1 and the urging force of the valve spring 2, and the intake and exhaust valves 5 are reciprocated.

The intake/exhaust valve mechanism 6 is provided with a so-called hydraulic tappet 7 for operating the valve in a zero lash state with no tappet clearance using hydraulic pressure (incompressibility of oil). This hydraulic tappet 7 is divided into sections by a sleeve 10 mounted in a recess 9 of a housing 8 constituting a fixed system, a lifter 11 slidably inserted into the sleeve 10, and the lifter 11 and sleeve 10. oil chamber 12
A socket 14 slidably connected to the lifter 11 to partition the inside and form a pressure chamber 13 between the socket 14 and the lifter 11.
and a valve ball 16 for opening and closing the pressure supply/discharge port 15 formed at the lower end of the socket 14 and communicating the pressure chamber 13 and the oil chamber 12; It mainly consists of a valve rod 17.

Above, the oil chamber 12 has a sleeve 10 and a socket 1.
An oil passage 19 bored in the housing 8 is connected to the housing 8 through the fourth through hole 18 and the like. The socket 14 is connected to the sleeve 1 by a spring 20 interposed between it and the lifter 11.
0 is brought into contact with the upper lid portion of the holder. The valve ball 16 is connected to the pressure chamber 1
It is housed in a retainer 21 that surrounds the pressure supply/discharge port 15 from the third side, and is configured to close the pressure supply/discharge port 15 by being biased by a valve ball spring 22 . A lifter bracket 23 is connected to the lower part of the lifter 11, and this lifter bracket 23 fixes the rocker shaft 3.

The above-mentioned hydraulic tappet 7 operates as follows. When the valve rod 17 advances, the valve ball 16 is actuated to open the pressure supply outlet 15. The pressure chamber 13 with the pressure supply/discharge port 15 open cannot maintain hydraulic pressure. Therefore, the valve driving force of the cam 1 is applied to the lifter bracket 2 that supports the rocker shaft 3.
3, the rocker arm 4 is swung with one end engaging the intake/exhaust valve 5 as a fulcrum. Then, the intake and exhaust valves 5 whose valve driving force is cut off enter a closed state.

By the way, in order to prevent friction between the swinging rocker arm 4 and the rocker shaft 3, it is necessary to supply lubricating oil between them.

Therefore, in the conventional intake and exhaust valve mechanism, the first
As shown in the figure, an arm 24 is extended laterally from the lifter bracket 23, and an oil passage 25 is bored in the arm 24 leading to the rocker shaft 3.
An oil pipe 26 extending to the housing 8 is provided protruding from the opening, and an oil passage 19 bored in the housing 8 is branched to have an oil hole 27 facing downward. Bracket 2
By fitting the oil pipes 26 on the third side, lubricating oil was supplied between the rocker arm 4 and the rocker shaft 3.

[Problems with the Background Art] However, since the position of the main body of the hydraulic tappet 7 is determined by the sliding surface of the sleeve 10, the fitting of the oil pipe 26 and the oil hole 27, which are far from that position, requires a clearance due to machining accuracy. 28 must be set. As a result, the oil has a clearance of 28
As a result, sufficient oil pressure cannot be obtained in the hydraulic tappet 7, making it impossible to accurately adjust the intake and exhaust valves 5, and making it impossible to supply sufficient lubricating oil to the sliding surfaces of the rocker arm 4 and sleeve 10. Nakatsuta.

As related technologies, ``Zero lash drive device for Rocker arm'' (Utility Model Application No. 57-30305) and ``Tappet used in valve mechanism of internal combustion engine'' (Utility Model Application No. 58-42310) have been proposed. ing.

[Purpose of the invention] This invention was made in view of the above-mentioned problems, and its purpose is to supply sufficient lubricating oil to the pivot point of the rocker arm to ensure smooth rocking of the rocker arm, and to prevent hydraulic pressure from entering the hydraulic tappet. An object of the present invention is to obtain an intake and exhaust valve mechanism for a variable cylinder engine that does not cause loss.

[Summary of the invention] In order to achieve the above object, this invention swingably supports a rocker arm that adjusts the seating force of the intake and exhaust valves on a lifter that is urged in the extrusion direction from the sleeve by hydraulic pressure in a hydraulic chamber. The present invention is characterized in that an oil passage is provided through the lifter and the lifter bracket to supply lubricating oil from the hydraulic chamber to the pivot point of the rocker arm. This makes it possible to supply lubricating oil to the pivot point of the rocker arm without any clearance in the middle of the oil path leading to the outside, and prevents lubricating oil passing through the oil path from leaking to the outside or causing oil pressure loss in the hydraulic chamber. This is what I did.

[Embodiment of the invention] A preferred embodiment of the invention will be described below with reference to the accompanying drawings.

The embodiment of this invention is similar to the conventional intake and exhaust valve mechanism except for the following points.

As shown in FIGS. 2 and 3, both the lifter 11A slidably inserted into the sleeve 10 and the lifter bracket 23A connected to the lower part thereof are formed thick. An oil passage 30 is provided through the thick lifter 11A and the lifter bracket 23A to supply lubricating oil from the oil chamber 12 to between the rocker shaft 3A and the rocker arm 4. Oil passage 30a on the lifter 11A side
In order not to impair the strength of the lifter 11A and to supply sufficient lubricating oil between the rocker shaft 3A and the rocker arm 4, there are several in the thickened peripheral wall (in the illustrated example, there are two in total, one each at opposing positions). ) is provided. In addition, the number of oil passages 30a on the lifter 11A side is reduced to reduce the number of oil passages 30a on the lifter 11A side in order to suppress backflow to the oil passage 30a on the lifter 11A side. (summarized in the book), and is set up to reach Rocker Shaft 3A.

As shown in FIG. 4, the lifter bracket 23
To summarize the oil passages 30b on the A side, an oil groove 32 is provided across the concave portion 31 of the lifter bracket 23A into which the bottom of the lifter 11A is fitted, and one end of this oil groove 32 is connected to one oil passage on the lifter 11A side. 30
A and the other end are communicated with the oil passage 30b on the lifter bracket 23A side, respectively, and the two ends are merged at the other end. The rocker shaft 3A is provided with an oil reservoir chamber 33 having an opening that partially faces the rocker arm 4. Lubricating oil is stored in this oil reservoir chamber 33 through the oil passage 30, and the rocker shaft 3A is inserted into the rocker shaft 3A from the opening. The structure is such that lubricating oil can be supplied between the rocker arm 4 and the rocker arm 4.

Note that 34 in FIG. 2 is an O-ring for sealing.

The operation of this embodiment having the above configuration will be explained.

Oil supplied from the oil passage 19 in the housing 8 flows into the oil chamber 12 and pressure chamber 13 of the hydraulic tappet 7A through the through hole 18 to fill them, while the oil passage passing through the lifter 11A and the lifter bracket 23A It also flows into the 30s. This through oil passage 3
The oil that has flowed into the rocker shaft 3A flows into the oil reservoir chamber 33 in the rocker shaft 3A and fills it, and oozes out between the rocker shaft 3A and the rocker arm 4 as lubricating oil from the opening. In this case, the oil passage 30 passing through the lifter 11A and the lifter bracket 23A does not have any clearance to the outside in the middle, and is opened only between the rocker shaft 3A and the rocker arm 4 that supply lubricating oil at the final end. This completely prevents oil leakage. Since oil leakage can be completely prevented, loss of hydraulic pressure into the hydraulic tappet 7A can be avoided, and the socket 14 can be completely prevented from leaking.
and lifter 11A and between lifter 11A and sleeve 1
Sufficient lubricating oil can be supplied to each sliding surface between 0 and 0.

Further, since oil is supplied from the oil chamber 12 of the hydraulic tappet 7A through the plurality of oil passages 30a provided in the lifter 11A, sufficient lubricating oil can be supplied between the rocker shaft 3A and the rocker arm 4. Moreover, since the oil passage 30 is constricted in the lifter bracket 23A, the supplied lubricating oil does not flow backward, and can always be kept in a sufficient amount on the sliding surface of the rocker arm 4.

As described above, according to this embodiment, sufficient lubricating oil can be supplied to each sliding surface of the rocker arm 4 and the sleeve 10 with a simple structure in which the oil passage 30 is provided in the lifter 11A and the lifter bracket 23A. The intake and exhaust valve mechanisms can be operated smoothly.

In addition, although the above embodiment describes the case where it is applied to a stopped cylinder, it can also be applied to an operating cylinder which does not have the valve rod 17 and is equipped with a similar hydraulic tappet to correct thermal deformation of each part of the valve train diameter. Needless to say. Furthermore, in the above embodiment, the rocker shaft 3A is fixed and the rocker arm 4 is rotatably supported by the rocker shaft. This can also be applied to a case where the oil passage 30 is provided rotatably relative to the rocker arm 4. In short, it is sufficient that the oil passage 30 reaches the pivot point of the rocker arm 4.

[Effects of the invention] In summary, the present invention provides the following excellent effects.

(1) Since an oil passage is provided in the lifter and lifter bracket to supply lubricating oil to the pivot point of the rocker arm through these, there is less oil leakage compared to conventional oil passages that have fitting points in the middle. There is no
By supplying sufficient lubricating oil to the pivot point of the rocker arm, the rocker arm can swing smoothly.

(2) The oil passage that passes through the lifter and lifter bracket prevents oil leakage, reliably preventing oil pressure loss into the hydraulic tappet, allowing the hydraulic tappet to function effectively, and allowing accurate adjustment of the intake and exhaust valve mechanisms. can.

(3) The structure is simple because it is only necessary to provide through holes in the lifter and lifter bracket.

[Brief explanation of drawings]

Figure 1 is a side sectional view of a conventional intake and exhaust valve mechanism;
The figure is a side sectional view showing a preferred embodiment of the intake and exhaust valve mechanism for a variable cylinder engine according to the present invention, FIG. 3 is a sectional view taken along the - line in FIG. FIG. 3 is a perspective view of the bracket. In addition, in the figure, 4 is the Rocker arm, 5 is the intake and exhaust valve,
7A is a hydraulic tappet, 10 is a sleeve, 11A is a lifter, 12 is an oil chamber, 23A is a lifter bracket, and 30 is an oil passage.

Claims (1)

[Scope of utility model registration request] A lifter bracket that swingably supports a rocker arm that adjusts the seating force of the intake and exhaust valves is connected to a lifter that is urged in the extrusion direction from the sleeve by hydraulic pressure in a hydraulic chamber, and a lifter bracket that swingably supports the rocker arm that adjusts the seating force of the intake and exhaust valves is connected to the lifter. An intake and exhaust valve mechanism for a variable cylinder engine, characterized in that an oil passage for supplying lubricating oil from the hydraulic chamber is provided at the pivot point of the rocker arm.