JPH0341646B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable displacement engine that can change the number of operating cylinders of the engine, and in particular, the present invention relates to a variable displacement engine that can change the number of operating cylinders of the engine. This invention relates to a valve stop device that reduces the load on the engine by stopping its operation.

[Prior Art] In general, a variable displacement engine reduces the number of cylinders to which fuel is supplied depending on the operating conditions of the engine, reducing the operating displacement and adjusting the valve operation corresponding to the cylinder to which fuel supply is stopped. It is widely known to reduce fuel consumption by stopping the engine.

As disclosed in Japanese Patent Application No. 57-62693, the valve stop device for the variable displacement engine divides the interior of the hydraulic tappet into a high-pressure chamber and a low-pressure chamber, and operates normally by applying hydraulic pressure to the high-pressure chamber. A hydraulic tappet device has been proposed in which the tappet is inoperative by discharging the hydraulic pressure in the high pressure chamber.

[Problem to be solved by the invention]

However, although the above-mentioned hydraulic tappet device has the function of activating and deactivating the intake and exhaust valves, when the hydraulic pressure in the high pressure chamber is discharged and the tappet is deactivated, a sleeve is used to release the pressure oil. The disadvantage was that the through hole was too small, making it difficult for pressure oil to escape to the discharge passage side. On the other hand, when supplying pressure oil to the high pressure chamber, the cross-sectional area of the passage must be made as small as possible in order to increase the oil pressure. Sometimes we want something bigger.

The present invention has been devised in view of the above-mentioned problems of the conventional art, and its purpose is to quickly release air from the through hole formed in the sleeve of the hydraulic tappet when the intake and exhaust valves are not in operation. The present invention provides a valve stop device for a variable displacement engine that can quickly switch an intake/exhaust valve into an operating state and into a non-operating state by discharging pressure oil.

In order to achieve the above object, the valve stop device for a variable displacement engine according to the present invention includes a sliding member having a concave cross section fixed to the upper part of a bracket that pivotally supports the rocker arm of the intake and exhaust valve. A plunger is fitted into a sleeve with a concave cross section embedded in the sleeve to form an oil chamber, and a plunger with a concave cross section is fitted inside the sliding body and has an orifice passage at the lower end and is pressed against the ceiling side of the sleeve by a spring. The oil chamber is divided into a high pressure chamber and a low pressure chamber communicating with a pressure oil supply port, a check ball is provided on the high pressure chamber side that is always biased in a direction to close the orifice passage, and a cylinder reduction switch is provided. A rod is provided through the sleeve to open the check ball by being actuated by an electromagnetic mechanism excited by turning on the valve, and a rod is provided through the sleeve to stop the supply of pressure oil to the oil chamber in conjunction with the operation of the electromagnetic mechanism. The apparatus includes an oil supply stop means and is comprised of a throttle mechanism that enlarges the pressure oil flow distance between the through hole of the sleeve and the rod only when the rod is in operation.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, a cam 5 of a camshaft 3 is supported in a cylinder head 1, and an intake and exhaust valve 7 is inserted into the cylinder head 1 while being urged by a spring 9.

A housing 11 is fixed to the upper part of the cylinder head 1, and a sleeve 15 having a concave cross section is embedded in a hole 13 formed at the bottom of the housing 11. A sliding body 17 having a concave cross section is fitted inside the sleeve 15 so as to be able to move up and down.
A rocker arm 21 is pivotally supported at the lower end of a bracket 19 that is integrally attached to the lower part of the sliding body 17. Further, the lower surfaces of both ends of the rocker arm 21 are in contact with the cam 5 and the intake/exhaust valve 7.

A plunger 25 having an orifice passage 23 bored in the lower part thereof is slidably fitted inside the sliding body 17 as shown in FIG.
5, an upper low pressure chamber 29 and a lower high pressure chamber 27
The area is divided into sections.

A supply port 37 connected to a pump 35 connected to an oil pan 33 via a passage 31 is bored in the side wall of the sleeve 15, and a through hole 41 for a discharge passage 39 is bored in the upper wall of the sleeve 15. It is set up.

The plunger 25 is urged upward by a spring 43 disposed below and is locked by a spacer 45 disposed above it. A net-like spring presser 47 is attached to the lower side of the plunger 25,
A check ball 51 that is biased by a spring 49 and closes the orifice passage 23 is mounted inside the spring holder 47.

A solenoid 53 as an electromagnetic mechanism is screwed into the housing 11 into which the sleeve 15 is fitted, as shown in FIG. and a cylinder reduction switch 5 connected to a power source 57
9 through a connecting line 61.

A rod 63 is installed inside the solenoid 53 so as to be able to move up and down, and this rod 63 passes through the through hole 41 and brings its tapered tip close to the check ball 51.

A rod 63 passes through this through hole 41.
A check ball 51 of the rod 63 is provided on the outer periphery of the rod 63.
A recess 65 constituting a "variable aperture mechanism" is formed at a position relative to the through hole 41 when pressed.

In the above configuration, first, during normal operation of the engine, engine oil in the oil pan 33 pushes down the check ball 51 of the high pressure chamber 27 from the passage 31 via the pump 35 and fills the high pressure chamber 27, and the variable throttle mechanism is activated. In the throttled state, the check ball 51 closes the orifice passage 23 due to the pressure difference between the high pressure chamber 27 and the low pressure chamber 29 from which oil is discharged from the through hole 41.

Therefore, in the above state, the engine is driven and the cam 5
When the slider 1 rotates, the slider 1 is moved through the high pressure chamber 27.
7 is locked, the rocker arm 21 swings and the intake and exhaust valves 7 move up and down by a predetermined amount.

Next, for example, when the load on the engine decreases and the cylinder reduction switch 59 is turned on, the electromagnetic cutoff valve 55 is activated and closed, cutting off the oil supply from the pump 35 and energizing the solenoid 53. 63 is lowered against the spring 67 as shown in FIG.
is pushed down to communicate the high pressure chamber 27 and low pressure chamber 29 through the orifice passage 23, and the concave portion 65 of the rod 63 is positioned in the through hole 41 to widen the passage and reduce the throttling effect.

When the cam 5 rotates in this state, the rocker arm 21 is pushed up as shown by the chain line in FIG. 1, and the sliding body 17 is pushed up via the bracket 19 accordingly. At the same time, oil flows from the high pressure chamber 27 to the low pressure chamber 29 to the intake and exhaust valve 7.
The variable diaphragm mechanism is opened wider than when the valve is activated, and the air is discharged from the through hole 41 with less resistance to passage, and the intake and exhaust valves 7 are not activated in order to reliably absorb the vertical movement of the rocker arm 21 driven by the cam 5. Therefore, the inside of the cylinder is no longer pressurized.

In the embodiment shown in FIG. 4, the rod 63a is equipped with an aperture plate 69 as a variable aperture mechanism on the inside of the sleeve 15, and when the rod 63a is operated (lowered), the aperture plate 69 is The flow cross-sectional area of the through hole 41, which has been reduced in size, is increased as the throttle plate 69 moves downward, thereby reducing the throttle effect.

Furthermore, in the embodiment shown in FIG. 5, the rod 65b is formed inside the sleeve 15 as a convex portion 71 having a large diameter as a variable throttle mechanism, and the upper side of the rod 65b is normally formed in the sleeve 1 of the through hole 41.
5 side is narrowed, and the flow cross-sectional area of the through hole 41 is made large when the rod 63b is operated, that is, the throttling effect is reduced.

Furthermore, FIG. 6 shows the through hole 41 of the rod 63c.
The insertion portion of the rod 63c is formed larger than other portions as a large diameter portion 73 serving as a variable diaphragm mechanism.
When the rod 63c is lowered during operation, the small diameter portion 75 is located at the insertion portion of the through hole 41, increasing the flow cross section of the through hole 41 and reducing the throttling effect.

In the embodiment shown in FIG. 7, a part of the upper surface of the sleeve 15 is formed as a valve plate 77 as a variable diaphragm mechanism, and this valve plate 77 is normally biased in the closing direction by a spring 79. The through hole 41 in the center of this valve plate 77
A rod 63d is inserted through the hole.

In this embodiment, when the rod 63d is pushed down, the ring 81 mounted on the rod 63d
presses the valve plate 77 against the spring 79 to open it, so the flow cross-sectional area is significantly increased, the throttling effect is significantly reduced, and the oil flowing through this area is discharged smoothly without resistance. become.

The valve stop device for a variable displacement engine according to the present invention has a sliding body with a concave cross section fixed to the upper part of a bracket that pivotally supports the rocker arm of the intake and exhaust valves, and a sliding body with a concave cross section embedded in the housing at the upper part of the cylinder head. Fits inside the sleeve to form an oil chamber,
An orifice passage is provided at the lower end inside the sliding body,
A plunger having a concave cross section that is pressed against the ceiling side of the sleeve by a spring is fitted to divide the oil chamber into a high pressure chamber and a low pressure chamber communicating with a pressure oil supply port, and an orifice is always provided on the high pressure chamber side. A check ball is provided that is biased in a direction to close the passage, and a rod is provided that penetrates the sleeve and opens the check ball when actuated by an electromagnetic mechanism that is excited when the cylinder reduction switch is turned on, and the electromagnetic mechanism A pressure oil supply stop means is provided to stop the pressure oil supply to the oil chamber in conjunction with the operation of the rod, and the pressure oil flow distance between the through hole of the sleeve and the rod is expanded only when the rod is activated. It is configured with a variable aperture mechanism.

Therefore, when the intake and exhaust valves are not operating, pressure oil can be quickly discharged from the through hole formed in the sleeve of the hydraulic tappet that constitutes the variable throttle mechanism, and the switching between operation and non-operation of the intake and exhaust valves is ensured. This has the excellent effect of being able to perform this process smoothly and reliably, resulting in a reliable reduction in fuel consumption.

[Brief explanation of the drawing]

FIG. 1 is an overall sectional view of a valve stop device according to an embodiment of the present invention, and FIGS. 2 and 3 are enlarged sectional views of essential parts, respectively. Figures 4, 5, 6 and 7 are partial sectional views of the rod portion showing other embodiments. 7... Intake and exhaust valve, 11... Housing, 15...
... Sleeve, 17 ... Sliding body, 21 ... Rocker arm, 23 ... Orifice passage, 25 ... Plunger, 27 ... High pressure chamber, 29 ... Low pressure chamber, 37
... Supply port, 41 ... Through hole, 51 ... Check ball, 53 ... Solenoid, 55 ... Solenoid cutoff valve.

Claims (1)

[Claims] 1. A sliding body with a concave cross section fixed to the upper part of the bracket that pivotally supports the rocker arm of the intake and exhaust valve is fitted into a sleeve with a concave cross section embedded in the housing at the upper part of the cylinder head to form an oil chamber. A low pressure chamber is provided with an orifice passage at the lower end inside the sliding body, and a plunger having a concave cross section that is pressed against the sleeve ceiling side by a spring is fitted to communicate the oil chamber with a high pressure chamber and a pressure oil supply port. A check ball is provided on the high pressure chamber side which is always biased in a direction to close the orifice passage, and a rod is actuated by an electromagnetic mechanism excited by turning on a cylinder reduction switch to open the check ball. A pressurized oil supply stop means is provided through the sleeve and stops the supply of pressure oil to the oil chamber in conjunction with the operation of the electromagnetic mechanism, and the pressure oil supply stop means is provided to stop the supply of pressure oil to the oil chamber in conjunction with the operation of the electromagnetic mechanism. Pressure oil flow between
A valve stop device for a variable displacement engine that is equipped with a variable throttle mechanism that expands the flow rate.