JPS59229012A - Valve operating mechanism of internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent production of impact at a time when a valve is seated, by a method wherein, in a valve operating mechanism in which a piston is attached to a valve shaft, a valve is hydraulically opened, and the valve is opened through the force of a spring, a damper, which, during closing of a valve, works before a valve is seated, is provided. CONSTITUTION:A suction and exhaust valve is opened through a pressure in an oil chamber 12 exerted on a piston 9 attached to a valve shaft 8, and is closed through the force of a spring. Through control of electromagnetic valves according to engine properties, an electromagnetic valve 41 is opened and an electromagnetic valve 56 is closed during opening of the exhaust valve to supply an oil pressure to an oil chamber 12 through a feed port 42 and a check valve 52, and a valve shaft 8 is depressed to open the valve. When the electromagnetic valve 41 is closed and the electromagnetic valve 56 is closed, the valve shaft 8 is pushed through the force of a valve-closing spring and is moved upward, an oil pressure in the oil chamber 12 is bled to a discharge port 16. Meanwhile, when the check valve 52 is closed and a projection 54 enters a large size part 55, upward movement of the valve shaft 8 is decreased in speed, and the suction and exhaust valve is gently seated.

Description

[Detailed description of the invention] This relates to an electrically and hydraulically driven valve mechanism I.

Generally speaking, from the standpoint of the performance of an internal combustion engine, it is desirable that the intake valve and exhaust valve have as large a gas passage as possible and be able to open and close rapidly. The important factor that determines the limit to which the valve can be moved rapidly is the mass and rigidity of the mechanism that seamlessly transmits the lift generated by the cam to the valve. Therefore, the valve mechanism must be as light and rigid as possible; the closer the intake (exhaust) valve located in the cylinder head is to the camshaft, the easier it is to satisfy this condition.On the other hand, the camshaft is driven by the crankshaft. Therefore, the closer it is to the left, the more complex the drive system becomes.

Based on the above, a mechanical cam-driven valve mechanism has its limitations and cannot fully demonstrate the performance of an internal combustion engine. A number of proposals have been made for the control of
0-, 39763, etc.].

An example of this proposal 1 To give an overview, as shown in Figure 1, 1 is a cylinder hedge, 2 is an intake or exhaust port, 3 is an intake or exhaust valve, 4 is a valve box, and 5 is a valve. The actuator main body 6 constituting the box 4 is a spring holder for receiving a valve spring 7 and is built into the valve box 4. A piston 9 is attached to the tip of a valve shaft 8 of the suction (discharge) valveless valve 3, and the piston 9 slides up and down within a cylinder 10 bored in the actuating section main body 5. The lower side of the cylinder 10 is an air chamber 11, and the upper side is an oil chamber 12. A hydraulic oil supply port 13 is provided on the end face I of the cylinder 10, and the hydraulic oil supply port 13 is communicated with a spool valve chamber 14. A hydraulic oil outlet 15 is opened in the spool valve chamber 14,
The discharge port 15 communicates with an oil tank 16. A spool valve 30 provided with lands 17, 1.7 and a spool 1''8 is housed in the spool valve chamber 14 so as to be able to slide up and down.A spool valve spring 20 is housed below the spool valve 30. However, the spool valve 30 is constantly pushed upward. An active core 31 is connected to the upper end of the spool valve 30, and the active core 31 slides up and down within the oil chamber 32. The upper end of the active core 31 A core spring 34 wound around the adjustment screw 33 presses it.

An oil well 35 is bored in the adjustment screw 33 so that the hydraulic oil communicated with the oil chamber at the upper end of the spool valve 30 and the oil well 36 of the active core 31 escapes to the oil tank 16. A solenoid 37 is embedded in the outer periphery of the oil chamber 32 in the actuator main body 5.

The solenoid valve 37 detects various operating characteristics (rotational speed, load condition, etc.) of the internal combustion engine 38 and is operated by a signal processed by a microcomputer 39, which serves as an electrical input signal. Hydraulic oil is introduced into the hydraulic oil supply port 13 of the chamber 14 by a pressure pump 40 driven by an internal combustion engine 38 .

Since this is the valve operating system, a signal from the microcomputer 39 energizes the solenoid r37, the active core 31 is sucked, the spool valve 30 is pushed up by the spool valve spring 20, and the high pressure hydraulic oil supply port 1
3 and the oil chamber 12 of the cylinder 10 communicate with each other to move the piston 9 downward. Therefore - open the intake (exhaust) non-valve 3. The piston 9 moves until it hits the lift limit and remains stationary in that state while the solenoid 39 is energized.

Next, when the current to the thread/id 39 is cut off, the spool valve 30 returns to its original state due to the single core spring 34, the hydraulic oil supply port 13 is closed, the communication passage 41 and the hydraulic oil discharge port 15 are communicated, and the oil The hydraulic oil in chamber 12 is drained.

Therefore, the intake (exhaust) non-valve 3 is seated on the valve seat by the valve spring 7, and the intake (exhaust) boat 2 is closed.

As seen in the above conventional example, the return speed of the piston due to the oil pressure I, that is, the return speed with no suction (discharge) valve or the seating state, is determined by the discharge resistance of the hydraulic oil in the oil chamber where the piston operates and the valve spring. Since it depends on the force, the return speed can be increased by strengthening the valve spring. However, if the valve spring is strengthened, problems such as an increase in the energy required when opening the valve and damping when the valve is seated occur, which is not preferable.

Therefore, the present invention was created to solve this problem, and the one-acting valve mechanism is driven by electrically controlled hydraulic pressure, and a damper is attached to the oil chamber of the hydraulic piston. The aim is to improve seating without intake (exhaust) valves. -Hereinafter, the configuration of the present invention will be explained in detail based on the first and second embodiments.

Fig. 2 is a sectional view of the main part of the first embodiment, and Fig. 3 is a diagram showing the operating state of Fig. 2. The same parts or equivalent parts as in the embodiment of Fig. 1 are indicated by the same reference numerals, and their explanations are as follows. omitted. 41 is a switching valve, which corresponds to the spool valve 30 in FIG. A supply port 42 communicating with the pressure pump 40 is provided in the switching valve 41, and the valve body 43 is always pressed toward the solenoid side by the hydraulic pressure of the hydraulic oil. The valve body 43 has a needle bar 31 provided therein.
Core spring 24 (corresponding to the active core 31 in Fig. 1)
Therefore, the pressure of the hydraulic oil is increased and the valve seat 44 is pressed against the valve seat 44. A recess 4 is provided at the top of the piston 9 provided at the tip of the valve shaft 8.
5, and a damping piston 46 is mounted thereon.

A spool 47 is formed on the damping piston 46,
It communicates with the center hole 48 of the piston 46 . center hole 4
The lower end of 8 is open at four parts 45, and the upper end is constricted by a diaphragm hole 49.

The spool 47 is provided with an opening 50 of the switching valve 4'1.
．． On the opposite side of the opening 50, 15 hydraulic oil discharge ports are provided. The hydraulic oil outlet 15 and the oil chamber 12 formed at the top of the piston 9 are short-circuited by a bypass 5, and a check valve 52 having a throttling function is interposed in the bypass 51.

Note that a switching valve having the same structure as the switching valve 41 is interposed in the hydraulic oil outlet 15 and communicates with the oil tank 16, but this is not shown.

Because of the structure of the first embodiment, its operation is controlled by the third embodiment.
This will be explained with a diagram. When the solenoid) 37 is energized, the needle bar 31
is attracted against the core spring 34, and the valve body 41 is opened by the high pressure of the hydraulic oil, pushing the piston 9 and check valve 52 through the center hole 48 of the damping piston 46, and pushing down the piston 9. Open the check valve 52. This is the state indicated by ■ in FIG. At this time, the damping piston 46 also moves down by Δt.

Next, when the switching valve (not shown) of the hydraulic oil discharge port 15 opens and the oil pressure in the oil chamber 12 decreases, the piston 9 is raised by the valve spring 7I, and becomes the state shown in FIG. 3. In this state, the check valve 52 gradually closes, so the hydraulic oil in the oil chamber 12 is
By passing through the notch 53 on the outer periphery of the piston 46 while being squeezed by the recess 45 and damping, the upward movement of the Lee piston 9 is relaxed and a so-called damping action begins.

Furthermore, when the piston rises and reaches the state shown in Figure 3 ■,
Since the top of the piston 9 presses down the damping piston 46 together, the hydraulic oil flowing into the top of the damping piston 46 gradually escapes through the throttle hole 49 to the hydraulic oil outlet 15. Therefore, the piston 9 moves upward slowly and returns to the state shown in (2) in FIG.

Therefore, since the damping piston 46 is only placed in the recess 46 of the screw 9, it is in a free state, and the damping force can be determined by the position of the piston 9 using a conventional fixed damper. It is possible to avoid inconveniences such as excessive damping of the intake (exhaust) non-valve 2, poor closing of the exhaust valve 2, excessive seating speed, etc. due to misalignment, dimensional changes due to heat, etc.

In addition, ``■'' in FIG. 3 shows the IJ valve without suction (exhaust) valve in this embodiment 1 and the operating state graphs ``■'' to ``■''.

Next, FIG. 4 shows a second embodiment of the present invention, and this figure shows a fixed damper for the sake of simplicity. Oil 'Mx' in the operating part main body 5
2, and the piston 9 slides up and down in the oil chamber 12. A convex portion 54 is provided at the top of the piston 9, and a convex portion 54 is provided at the top of the piston 9, and the supply port 42
fits into a large diameter portion 55 provided in the opening. The supply port 42 branches into two, one communicating with the pressure pump 4° via a switching valve 41 for supply, and the other communicating with the oil tank 16 via a switching valve 56 for discharge. The oil chamber 12 is short-circuited to the supply port 42 via a check valve 52 having a throttle function.

In this embodiment, in particular, an oil chamber 57 is provided below the piston 9, and the oil chamber 57 and the downstream side of the switching valve 56 are connected through a bypass passage 58, so that the oil is discharged when the piston 9 rises. The hydraulic oil that has been removed flows into the oil chamber 57 again to increase the rising speed of the piston 9.

In summary, the present invention detects the operating characteristic values of an internal combustion engine and receives them as electrical input signals.A computer and a piston connected to a non-intake (exhaust) valve shaft equipped with a one-valve spring are provided. A valve operating mechanism in which an oil chamber is provided in which the piston is freely slidable, and a solenoid valve is provided for supplying or discharging high-pressure hydraulic oil to the oil chamber, and the solenoid valve is controlled by the computer, attaching a damper to the piston,
In addition, since this is a valve mechanism for an internal combustion engine characterized in that the supply speed of hydraulic oil to the oil chamber is faster than the discharge speed, the intake (discharge) non-valve opening occurs rapidly, while the blockage is slow. This allows for soft seating. Additionally, by installing a damper in the oil chamber, the hydraulic oil pressure can be increased without strengthening the valve spring, allowing the valve to open and close rapidly.
Engine performance can be improved as above.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a conventional valve mechanism, Fig. 2 is a sectional view of main parts of the first embodiment of the present invention, Fig. 3 is an operating state diagram and valve lift graph of Fig. 2, and Fig. 4 The figure shows a sectional view of a main part of the second embodiment. 3... No intake (exhaust) valve, 7... Valve spring, 8... Valve shaft, 9... Piston, 12... Oil chamber, 46... Damping piston, 52... Reverse Patent attorney Yoshihiko Okabe

Claims (1)

[Claims] A computer that detects operating characteristic values of an internal combustion engine and receives them as electrical input signals, and a piston connected to a non-valve shaft equipped with a valve spring are installed, and the piston is moved by sliding. A freely built-in oil chamber is provided, and a solenoid valve for supplying or discharging high-pressure hydraulic oil is provided in the oil chamber.1 In a valve operating mechanism in which the solenoid valve is controlled by the computer, a damper is attached to the piston, and A valve mechanism for an internal combustion engine, characterized in that a supply speed of hydraulic oil to the oil chamber is faster than a discharge speed.