JPS62279218A - Valve stop device for vehicle engine - Google Patents

Abstract

PURPOSE:To switch an intake/discharge valve freely between function and stoppage by providing a cam for controlling between rotation and non-rotation through a hydraulically operatable coupling shaft between splitted cam shafts associated with individual fixed cam. CONSTITUTION:Cams 2a, 3a associated respectively with fixed cams 2, 3 are coupled through a coupling shaft 5 having the splines 4a, 4b at the opposite ends thereof which are fitted in the spline grooves 2b, 3b made in the central hole of each cam shaft. A cam I is provided between both cam shafts 2a, 3a and a coupling shaft 5 is provided slidably at the inside. An eccentric hole 6 is provided at the inside of the cam I and an eccentric shaft section fittable in said eccentric hole 6 is providing at the intermediate section of the coupling shaft 5. When a hydraulic exchange valve 16 is under the condition shown by the drawing, pressurized oil is fed into a chamber 14 thereby the coupling shaft 5 is not coupled with the cam 1 thus preventing the rotation of the cam 1. When the valve 16 is rotated to the right by means of an electromagnetic device 17, pressurized oil is fed into a chamber 13 so as to move the coupling shaft 5 to the right and to fit in the hole 6 through the rotation of the shaft thus rotating the cam 1.

Description

[Detailed description of the invention]

3. Detailed description of the invention

[Industrial application field] The present invention relates to a valve stop device for an automobile engine. [Conventional technology]

In terms of automobile engines, 2-valve engines (1 intake, 1 exhaust valve per cylinder) generally have low-speed output characteristics, while 4-valve engines (2 intake, 2 exhaust valves per cylinder) or 3-valve engines have low output characteristics. (2 intake valves, 1 exhaust valve per cylinder) output characteristics are high-speed type. Therefore, if multiple intake valves are used, 4 or 3
In a valve-type engine, at least one of the intake valves is stopped in the low speed range and released in the high speed range, so that sufficient output can be obtained over a wide range from the low speed range to the high speed range. Specific means for this purpose include shifting the fulcrum position of the rocker arm, incorporating a stopping mechanism into the rocker arm itself (see Japanese Patent Laid-Open No. 57-86512), and configuring the rocker arm separately for high-speed and low-speed use. However, there is a known method (see Japanese Patent Laid-Open No. 188715/1983) in which one of these is selected and used.

[Problems to be solved by the invention]

The problem here is that with the above method, the mechanism related to the rocker arm becomes complicated, and the inertia weight of the rocker arm in particular increases dramatically, which reduces the number of rotations at which jumps and bounces occur in the valve train. However, as a result, the number of rotations used by the engine decreases. The present invention was made based on the above circumstances, and by incorporating a hydraulic control system inside the camshaft and cam,
It is an object of the present invention to provide a valve stop device for an automobile engine that can stop and drive a variable valve without increasing inertial weight to a rocker arm. (Means for solving the problem 1) For this purpose, in a valve train having intake and exhaust valves, the present invention provides a system in which adjacent cams are rotatably fitted to the camshaft of each adjacent cam. The movable cam is equipped with a piston that is spline-fitted coaxially with the camshaft, the piston is provided with a knock pin, and the piston has an eccentric hole that fits with the knock pin. is provided on the movable cam, and the knock pin is engaged with and disengaged from the eccentric hole by hydraulic control of the piston.

[Function 1] Based on the above configuration, the present invention transmits power from the camshaft to the movable cam only when the knock pin is fitted into the eccentric hole, and causes the rocker arm to swing at other times. Therefore, valve stop control can be easily performed, and there is no increase in inertia force on the rocker arm, and the engine operating speed can be set sufficiently high. [Embodiment] Hereinafter, an embodiment of the present invention will be specifically described with reference to FIGS. 1 and 2. In these figures, numeral 1 is a movable cam for stopping the valve, and camshafts 2a, 3
It is placed between fixed cams 2.3 provided at a. The camshafts 2a, 3a have coaxial splines 2b, 3b formed at their opposing ends, and the joint 4, which has splines 4a, 4b that fit into the splines 2b, 3b, integrally connects the piston 15. It is constructed as follows, and is fitted into hydraulic chambers 13 and 14 formed inside the movable cam 1 so as to be freely movable. The movable cam 1 has an eccentric hole 6 formed therein.
A knock pin 5 that is inserted into the eccentric hole 6 is formed in the joint 4. Furthermore, a compression coil spring 19 is installed inside the hydraulic chamber 14, and elastically supports the knock pin 5 from the eccentric hole 6 in the direction 111trJ. Further, a stopper 2c is provided on the surface of the camshaft 2a facing the joint 4 so that the position of the joint 4 within the camshaft 2a is regulated. Above movable cam 1
A pressure oil inlet/outlet lower and 8 are open in the boss portion of the spool valve 16.
It is connected to the hydraulic chamber. The spool valve 16 is supported by a spring 18 and operated by a solenoid 17. Therefore, when the solenoid 17 is off and the spring force of the spring 18 is working (see FIG. 1), the oil pressure is applied to the right oil passage 12. Only when the rocker arm corresponding to the cam 1 is present on the base circle via the boat 10, the boat 10 communicates with the entrance/exit 8 and is supplied to the right hydraulic chamber 14. This oil pressure acts on the piston 15 of the joint 4 and pushes the joint 4 leftward in the figure. Therefore, the joint 4 moves until it comes into contact with the stopper 2c drawn on the bottom of the spline 2b of the camshaft 2a, and then stops. This sharpening oil chamber 13 is communicated with a drain to drain oil. In this state, the cams 2 and 3 rotate synchronously because they are spline-coupled at the joint 4, but the cam 1 is not coupled to these and therefore receives no rotational force. Therefore, the rocker arm corresponding to this cam 1 is not subjected to rocking force, and the intake valve is in a stopped state. The engine speed and square tube are detected, a computer etc. makes a judgment, and when the solenoid 17 is turned on, the second
As shown in the figure, pressure oil is supplied to the oil W13 only when the oil pressure is switched to the left oil passage 11° boat 9 and the rocker arm corresponding to the cam 1 is on the pace cheekle. Then, a rightward force acts on the piston 15 in the figure, and the joint 4 moves toward the eccentric hole G, but the axes of the knock pin 5 and the eccentric hole 6 (both eccentric with respect to the camshaft) If they do not match, the dowel pin 5 jumps into the eccentric hole G while the axes of the dowel pin 5 and the eccentric hole 6 coincide, and the engagement between the cam 1 and the camshafts 2a and 3a causes the joint 4 to move. achieved through. That is, this is the R period in which the rocker arm rests on the cam mountain. Effects of the Invention The present invention has been described in detail above, and when the present invention is used for variable cylinder number control, by reducing the number of cylinders when the engine is under low load, the valve driving force and the dynamic torque required for intake can be reduced. When used for variable valve control, it reduces internal EGR and improves swirl by increasing intake flow velocity. While improving fuel efficiency, it does not increase the inertia of the rocker arm, so the valve spring load can be reduced compared to conventional ones, reducing valve drive force and valve train friction. It is possible to obtain effects such as reducing the number of rotations, and to set the rotation speed for the open side to a sufficiently high value.

[Brief explanation of drawings]

Fig. 1 shows an embodiment of the present invention in a longitudinal cross-sectional side view, and Fig. 2 shows a circumferential longitudinal view of the valve when it is in operation. 1
It is a front view. 1...First cam of the month, 2.3...Cam, 2a, 3a.
...Camshaft, 2b, 3b...Spline, 4
...Joint, 4a, 4b...Spline, 5
...Knock pin, 6...Eccentric hole, 7.8...Entrance/exit, 9,1o...Boat, 11.12...Oil channel, 1
3. i4...-hydraulic chamber, 15...piston, 16...
...Spool valve, 17...Solenoid, 1B...
・Spring, 19... Compression coil spring, 2o...
Sleeve receiver.

Claims (1)

[Scope of Claims] A valve train having intake and exhaust valves is provided with a movable cam rotatably fitted to the camshaft of each adjacent cam between adjacent cams, the movable cam comprising: The piston is internally fitted with a spline and coaxially fitted to the camshaft, the piston is provided with a knock pin, the movable cam is provided with an eccentric hole that fits with the knock pin, and hydraulic control is applied to the piston. A valve stop device for an automobile engine, characterized in that the knock pin is configured to engage and disengage from the eccentric hole.