JPS648167B2 - - Google Patents

Abstract

PURPOSE:To supply oil sufficiently to the sliding surface of a rocker arm by installing an oil jet to a cylinder head cover together with providing this rocker arm with a through hole which supplies jetted oil to the sliding surface of the rocker arm. CONSTITUTION:Usually, a hydraulic lifter 30 reiterates expanding/contracting motion in a small scale in order to conduct well-know actions. However, when an engine load is small, a micro-computer operates a solenoid valve 50 by means of engine input signals in order to push a ball check valve 36 so as to connect a pressure chamber 34 to a reservoir 33. At this time, a rocker arm 15, which usually rocks taking the middle point of a shaft 20 as a fulcrum in order to open/close a valve 12, rocks taking the valve top end 12a as a fulcrum in order to suspend valve lift mechanism. As a result, the valve no longer opens or closes. Oil in an oil passage 23 is jetted from an oil jet 24 and directly supplied via a through hole 26 to an inner sliding surface 27, thereby sufficiently lubricating this sliding surface.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to an oil lubrication mechanism for a valve selector, and more specifically, to a valve selector oil lubrication mechanism, and more specifically, a pressure-feed hydraulic lifter is provided in a valve lift mechanism of an internal combustion engine. This invention relates to an oil lubrication mechanism for a rocker arm in a valve selector that controls the stoppage of valve operation.

(Prior Art) Various types of valve selectors for internal combustion engines have been proposed for the purpose of saving energy and improving fuel efficiency of vehicles.
What is disclosed in Publication No. 180709 is already known. That is, in this valve selector, a well-known pressure-feed type hydraulic lifter is slidably disposed within a cylinder head cover, and both ends are connected to a rocker support that fixes the lower part of the hydraulic lifter to the cam and the upper end of the valve. A rocker arm is attached that slides around the rocker shaft that is in contact with and fixed to the rocker support, and the valve stem pushes open the check valve of the hydraulic lifter by means of a solenoid valve that operates in response to an engine input signal. It removes rigidity. Therefore, since the hydraulic lifter and the Rocker support move up and down together, the Rocker arm does not swing around the Rocker shaft as a fulcrum when operating the valve lift due to the rotation of the cam. The valve begins to swing up and down using the fulcrum as a fulcrum, and the lift operation of the valve stops.

Therefore, such an oil supply mechanism to the valve selector arm is disclosed in Japanese Patent Application Laid-Open No. 59-60014 (Japanese Patent Application No. 57-6001), which is an earlier application of the applicant of the present invention.
170669). This oil supply mechanism has a main oil passage in the cylinder head cover that supplies oil to the hydraulic lifter, a vertical hole that communicates with the main passage, and a pipe that moves up and down together with the rocker support into the vertical hole. The pipe is slidably inserted, and the oil in the vertical hole is connected to the sliding surface of the rocker arm through a passage provided in the center hole of the pipe, the lower bottom surface of the hydraulic lifter, and the rocker support. be.

(Problems to be Solved by the Invention) The oil supply mechanism described above includes a vertical hole communicating with the main oil passage, and a vertical hole inside the vertical hole, in order to supply oil in the main oil passage provided in the cylinder head cover to the rocker arm. The structure includes a center hole of the pipe slidably disposed in the pipe, a bottom bottom surface of the lower part of the hydraulic lifter communicating with the center hole, and a passage in the rocker support communicating with the end surface of the lower part. The oil supply passage is complicated and the diameter of the oil passage cannot be increased, making it difficult to ensure a sufficient amount of oil supplied from the main oil passage to the rocker arm, and the supply amount may be insufficient. It was a lot. As a result, there was a disadvantage in that the sliding surface of the rocker arm was worn out. In addition, the structure of the oil supply passage is complicated,
In particular, since the pipe can be slidably installed in the vertical hole, processing precision is required for the internal diameter of the vertical hole and the external diameter of the pipe, resulting in a significant increase in manufacturing costs. It was hot.

Therefore, the technical object of the present invention is to ensure a sufficient amount of oil supplied to the rocker arm.

[Structure of the invention]

(Means for solving the problem) The technical means taken to solve the above technical problem is to provide an oil jet in the oil passage formed in the cylinder head cover to supply oil to the hydraulic lifter. The oil is injected toward the rocker arm, and the oil injected from the oil jet is supplied to the sliding surface of the rocker arm through a through hole provided in the rocker arm toward the oil jet.

(Function) Oil pumped under pressure is supplied to an oil passage in the cylinder head cover, and the oil in the oil passage is injected toward the rocker arm by an oil jet. Since the rocker arm is provided with a through hole that communicates with the inside, oil injected by the oil jet is supplied to the sliding surface of the rocker arm through the through hole. In this way, oil is injected directly from the oil jet towards the rocker arm, so
A sufficient amount of oil can be supplied to the sliding surface of the rocker arm.

〔Effect of the invention〕

Since the present invention has the oil jet opened to the outside as described above, the oil jet also functions as an air vent hole for releasing air contained in the oil to the outside. Also,
Since the oil jet injects the oil in the oil passage in the cylinder head cover, oil can be supplied to the rocker arm and lubrication can be started immediately after the engine is started. Furthermore,
Since no special passage member is required for supplying oil to the rocker arm, the weight of the device does not increase and the structure does not become complicated.

〔Example〕

An embodiment embodying the present invention will be described below with reference to the accompanying drawings. The drawing is a longitudinal sectional view of an oil lubrication mechanism for a valve selector in a valve lift mechanism for an internal combustion engine, showing an embodiment of the present invention. Communication between a combustion chamber formed above a piston (not shown) and a cylinder head port 10 is controlled to open and close by a valve 12, and the valve 12 is always urged to close by a valve spring 14 supported by a retainer 13. There is. The rocker arm 15 has one end 15a in contact with the upper end 12a of the valve 12 via an adjustment screw 17 fixed by a nut 16, and the other end 15b in contact with the cam 18.
is in contact with the cam surface of the Further, the Rocker arm 16 is fixed to the Rocker support 19, and the Rocker arm 16 is fixed to the Rocker support 19, and the Rocker arm 16 is fixed to the Rocker support 19.
The rocker shaft 20, which is pivotally supported by the rocker shaft 20, is pivotable about its axis as a fulcrum. And cam 1
When the valve 8 rotates, the rocker arm 15 swings, and the valve 12 repeatedly opens and closes via the adjusting screw 17.

A lower lifter body 31 of a known pressure-feeding hydraulic lifter 30 is press-fitted into the hollow portion 19a of the rocker support 19. Also, hydraulic lifter 3
The lifter body 31 in the upper part of the cylinder head cover 21 is slidably inserted into a sleeve 22 fixed to the bore 21a of the cylinder head cover 21. A plunger 3 is disposed within the lifter body 31 so as to be able to reciprocate in the vertical direction, and a reservoir 33 is formed inside the plunger 32 . Inside the reservoir 33 are an oil passage 23 formed in the cylinder head cover 21 from an oil pump (not shown), a passage 22a of the sleeve 22, and a passage 32 of the plunger 32.
Oil is supplied via a.

Further, a pressure chamber 34 is formed in the lower part of the interior of the lifter body 31, and a plunger 3 is provided in the pressure chamber 34.
A ball check valve 36 that opens and closes an oil passage 35 provided at the center of the bottom of the valve 2 is provided. This check valve 36 allows oil to flow from the reservoir 33 to the pressure chamber 34, but in the opposite direction.
Oil flow from the pressure chamber 34 to the reservoir 33 is blocked. Also, the check valve 36 is connected to the retainer 3.
The other end of the spring 38, one end of which is supported by 7, is normally biased in the closing direction. A plunger return spring 39 having a larger load than the spring 38 is further interposed in the pressure chamber 34 .
9, the plunger 32 is always urged upward in the drawing.

A solenoid valve 50 fixed to the upper part of the cylinder head cover 21 is controlled and operated based on engine input signals such as vehicle speed, throttle opening, engine temperature, etc., by a microcomputer (not shown). The valve stem 51 of the solenoid valve 50 passes through the center hole 22b of the upper end surface of the sleeve 22 and projects into the reservoir 33 so as to be movable in the vertical direction.

Now, the cylinder head cover 21 is formed with an oil jet 24 for injecting the oil in the oil passage 23 toward the rocker arm 15, and the bore 25 through which the jet 24 opens is a through hole 26 formed in the rocker arm 15. are in the same direction. That is, the direction in which the bore 25 opens to the outside and the direction in which the through hole 26 opens to the outside face each other. The through hole 26 communicates with the inside of the rocker arm 15, that is, the sliding surface 27 with the rocker shaft 20.

The operation of the embodiment described above will be explained next. Normally, the hydraulic lifter 30 performs well-known operations by repeating small-sized expansion and contraction movements, but when the engine load is small, the microcomputer
For example, when the solenoid valve 50 is operated based on engine input signals such as engine load, vehicle speed, throttle opening, and engine temperature, the valve 50
In response to the operation, the valve stem 51 moves downward, pressing the check valve 36 downward and opening the oil passage 35.
open. Therefore, since both the pressure chamber 34 and the reservoir 33 communicate with each other, the oil in the pressure chamber 34 flows out into the reservoir 33, and the rotation of the cam 18 causes the rocker shaft 20 to oscillate about the center as a fulcrum during normal operation. The rocker arm 15, which had been used to open and close the valve 12, now swings about the upper end 12a of the valve 12 as a fulcrum, stopping the valve lift mechanism and preventing the valve 12 from opening and closing.

The oil supplied from the oil pump to the oil passage 23 is injected in the direction of the rocker arm 15 by the oil jet 24, and is supplied to the internal sliding surface 27 through the through hole 26 of the rocker arm 15. Lubricate.

[Brief explanation of the drawing]

The drawing is a longitudinal cross-sectional view of an oil lubrication mechanism for a valve selector showing an embodiment of the present invention. 12... Valve, 12a... Upper end of the valve,
15...Rotzker arm, 18...cam, 19...
...Rocker support, 20...Rocker shaft, 21...Cylinder head cover, 23...Oil passage, 24...Oil jet, 26...Through hole, 27...Sliding surface, 30...Force-feeding hydraulic lifter, 36 ... Ball check valve, 50 ... Solenoid valve.

Claims (1)

[Scope of Claims] 1. A solenoid valve that operates in response to an engine input signal, and a check valve that is slidably disposed within a cylinder head cover and that is pushed open by the solenoid valve, a pressure-feed hydraulic lifter whose rigidity is removed by the operation of the hydraulic lifter; an oil passage formed in the head cover to supply oil to the hydraulic lifter; a rocker support that fixes a lower portion of the hydraulic lifter; a rocker shaft fixed to the rocker shaft; a rocker arm having both ends in contact with a cam and an upper end of the valve and swinging around the rocker shaft; and an oil jet provided on the head cover for injecting oil in the oil passage to the rocker arm. An oil lubrication mechanism for a valve selector, comprising: a through hole provided in the rocker arm facing the oil jet and for supplying oil injected from the oil jet to a sliding surface of the rocker arm.