JPS61234213A - Control device of intake and exhaust valve - Google Patents

Abstract

PURPOSE:To provide rotors, which show a range that an intake or an exhaust valve, when it is opened and closed, moves not colliding against a piston, in a driving shaft and prevent the collision by detecting a position of the rotor, in the case of a device which electronically controls the opening and closing timing of the intake and the exhaust valve optionally in accordance with the operative condition of an engine. CONSTITUTION:An actuator, for controlling the valve timing of an intake and an exhaust valve, provided in a cam shaft or the like of the intake and the exhaust valve, is actuated by driving solenoids 10, 11 through an output signal of a control circuit part 5 calculated on the basis of an input signal of a load sensor 4, rotary angle sensor 3 and a top sensor 2. A control device provides the first rotor 25 and the second rotor 26, indicating a valve colliding crank angle if the intake and the exhaust valve opens with a piston in the vicinity of the top dead center, in a driving shaft of an engine, arranging the first and the second proximity sensors 27, 28 in said rotors. The valve can be opened in the period while each proximity sensor generates an output. In this way, the valve is prevented from colliding against the piston even if an abnormality signal is output with a control unit 1 breaking.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an intake and exhaust valve control device for controlling the opening and closing operations of intake and exhaust valves of an internal combustion engine.

<Prior art> Conventionally, intake and exhaust valve control devices for diesel engines, etc. open and close the intake and exhaust valves based on the outputs of a top sensor that detects the top position of the engine, a rotation angle sensor that detects the rotation angle of the engine, and a load sensor. A control signal is generated and applied to a solenoid for driving the intake and exhaust valves, thereby opening and closing the intake and exhaust valves. In such an intake/exhaust valve control device, when the CPU forming the control circuit malfunctions due to electrical noise, the piston and the intake/exhaust valve may collide with each other in a diesel engine. Therefore, the institution
The top of the piston is being scraped. However, if the upper part of the piston is cut in this way, the compression ratio cannot be increased and the machining cost is high.

<Objective of the Invention> The present invention has been made in view of the above-mentioned points, and an object of the present invention is to reliably prevent collision between the piston and the intake/exhaust valve without cutting the upper part of the piston.

<Structure of the Invention> In order to achieve the above-mentioned object, the present invention provides an intake valve that outputs control signals from a control circuit section to respective driving means of the intake valve and exhaust valve according to the load and the engine speed. In an exhaust valve control device, a first numeral is provided integrally on a camshaft or a shaft interlocking with the camshaft, and indicates the angular range in which the intake valve and the exhaust valve can be opened. Detecting the rotation angle of the second rotor and each of the rotors and outputting an intake valve opening permission signal and an exhaust valve opening permission signal indicating a period during which opening of the intake valve and the exhaust valve is permitted, respectively. 1゜Second valve opening permission signal generating means, and control included within the period in which the valve opening is permitted by inputting each of the valve opening permission signals and the control signal from the control circuit section to each drive means. First and second gate circuits are provided which output signals as real signals.

Therefore, according to the above configuration, the opening/closing operation of the intake and exhaust valves is controlled by the control signal within the permissible valve opening period, and the control signal outside the permissible valve opening period is excluded. Even if the CPU constituting the circuit section malfunctions due to noise, the piston and intake/exhaust valve will not collide, and there will be no need to cut the upper part of the piston as in the conventional case.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention.

This intake/exhaust valve control device l includes a top sensor 2 that is a means for detecting the top position of the engine, a rotation angle sensor 3 that is a means for detecting the rotation angle of the engine, and a load sensor 4 that is a means for detecting the load. and an intake/exhaust valve driving solenoid 1o which is an intake/exhaust valve driving means based on the output of each sensor 2, 3.4.

11. Note that 33 and 34 are power transistors.

The top sensor 2 is disposed opposite to a single tooth 7 fixed to a camshaft 6, and the rotation angle sensor 3 is disposed opposed to a ring gear 9 having a large number of teeth fixed to a crankshaft 8.

The control circuit unit 5 includes first to fourth counters 12 to 15, a RAM 19 in which data from the sensor 3.4 is temporarily stored, and a ROM in which data on opening and closing timing of intake and exhaust valves is stored in advance.
20, I10 boat 21° CPU22, 1st. It includes second waveform synthesis circuits 23, 24, etc.

The top signal from the top sensor 2 is given to the first to fourth counters 12 to 15 of the control circuit section 5, and the rotation angle signal from the rotation angle sensor 3 is given to the F/V converter 16 and the fourth counter of the control circuit section 5. It is given to the first to fourth counters I2 to I15. Further, the output signal from the load sensor 4 is transmitted to the amplifier 17.
The signal is applied to the A/D converter 18 via the A/D converter 18.

The first to fourth counters 12 to 15 count rotation angle signals by the number of counts given by the CPU 22, the first counter 12 generates an intake valve opening signal, and the second counter 13 generates an intake valve opening signal. generates a close signal. The first waveform synthesis circuit 23 generates a control signal corresponding to the opening timing of the intake valve from the open signal and the close signal from the first and second counters 12 and 13. Similarly, the third counter 14 generates an open signal for the exhaust valve, and the fourth counter 15 generates a close signal for the exhaust valve. The second waveform synthesis circuit 24 includes a third waveform synthesis circuit 24. A control signal corresponding to the opening timing of the exhaust valve is generated from the open signal and close signal from the fourth counter l4.15.

In the intake/exhaust valve control device 1 of the present invention, the first . A valve opening permission signal for the intake valve and a valve opening permission signal for the exhaust valve that detect the rotation angle of the 20th rotor 25, 26 and each rotor 25, 26 and indicate the period during which the opening of the intake valve and exhaust valve is permitted. The first signal outputs the first signal and the second signal. The first valve is the second valve opening permission signal generating means.
．． a second proximity sensor 27, 28 and each proximity sensor 27.2;
8 and the control signal from the control circuit section 5, and the control signals included within the period in which valve opening is permitted are output as actual signals. The first gate circuit is the second gate circuit. Second AND circuits 29 and 30 are provided. Note that 31 and 32 are waveform shaping circuits.

1st. As shown in FIG.
The large diameter portions 5 and 26 correspond to the angular range in which the intake valve and exhaust valve can be opened. This large diameter part is the first. When approaching the second proximity sensor 27, 2B, the outputs of both proximity sensors 27, 2B become high level, indicating that opening of the intake and exhaust valves is permitted. That is, the proximity sensor 27,
During the period when each valve opening permission signal from 28 is at a high level, the intake and exhaust valves can be opened and closed without colliding with the piston.

Next, the operation of the intake/exhaust valve control device 1 of the present invention having the above configuration will be explained based on the time chart of FIG. 2. Since the control operations for the intake valve and the exhaust valve are basically the same, the operation for controlling the intake valve will be described here.

First, the rotation angle signal shown in FIG. 2(B) from the rotation angle sensor 3 is sent to the F/V converter I6, A/D
is input to the CPU 22 via the converter 18, and the CPU
The rotation speed is calculated in step 22, and the rotation speed data is stored in RAM1.
9 is temporarily stored.

Further, the output from the load sensor 4 is sent to an amplifier 17, an A/D
It is manually input via the converter 18 and temporarily stored in the RAM 19 as a load. Based on the rotation speed and load data stored in the RAM 19, the opening/closing timing of the intake and exhaust valves is searched from a numerical table stored in the ROM 20 in advance.

The retrieved intake valve opening timing and valve closing timing are calculated as the count number of the corresponding rotation angle signal as described later. The signals are applied to second counters 12 and 13, respectively. 1st. The second counters 12 and 13 are given the top signal shown in FIG. 2(A) and the rotation angle signal of the rotation angle sensor 3, and both counters 12 and 13 receive It is reset and starts counting the rotation angle signal when it becomes high level. 1st. 2nd counter 1
2.13 is an open signal and a close signal [second
Figures (C) and (D)] are output respectively.

1st. The opening/closing signals from the second counters 12 and 13 are
The first waveform synthesis circuit 23 generates a control signal [FIG. 2(E)] corresponding to the open period and supplies it to one input terminal of the AND circuit 29. This A
The other input terminal of the ND circuit 29 is connected to the first proximity sensor 2.
An intake valve opening permission signal [FIG. 2 (F)] from 7 is given. Therefore, by the AND circuit 29,
During the period in which the signal from the first proximity sensor 27 is at a high level, that is, during the period in which opening of the intake valve is permitted, the control signal is transmitted to the power transistor 33 as an actual signal as shown in FIG. 2(G). given to. Therefore, only during the allowable opening period when there is no risk of the piston and intake valve colliding with each other.
Since the control signal is given to the power transistor 33 as an actual signal, even if the CPU of the control circuit section 5 malfunctions due to noise, the intake valve will not hit the piston.

<Effects of the Invention> As described above, according to the present invention, the intake and exhaust valve control is configured such that control signals are output from the control circuit section to each driving means of the intake valve and the exhaust valve according to the load and the engine speed. In the device, a first numeral is provided integrally on the camshaft or a shaft interlocking with the camshaft, and indicates the angular range in which the intake valve and the exhaust valve can be opened. Detecting the rotation angle of the second rotor and each of the rotors and outputting an intake valve opening permission signal and an exhaust valve opening permission signal indicating a period during which opening of the intake valve and the exhaust valve is permitted, respectively. 1st. A second valve opening permission signal generating means inputs each of the valve opening permission signals and a control signal from the control circuit section to each drive means to execute a control signal included within the period in which the valve opening is permitted. The first signal output as a signal. Since the second gate circuit is provided, the opening and closing operations of the intake and exhaust valves are performed only during the allowable opening period when there is no risk of the intake and exhaust valves colliding with the piston. Even if a malfunction occurs due to noise, the piston and intake/exhaust valve will not collide. Therefore, it is no longer necessary to cut the upper part of the piston as in the past, and the machining costs for this are eliminated, and the compression ratio can be increased.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
3 is a time chart of the embodiment shown in the figure. ■...Intake and exhaust valve control device, 2...Top sensor, 3
...Rotation angle sensor, 4...Load sensor, 5...Control circuit section, 25.26...1st. second rotor, 27.
28... 1st. 2nd proximity senna.

Claims (1)

[Claims] (1) In an intake/exhaust valve control device that outputs control signals from the control circuit to each drive means of the intake valve and exhaust valve in accordance with the load and engine speed, First and second rotors are integrally provided and each indicate an angular range in which the intake valve and the exhaust valve can be opened, and the rotation angle of each rotor is detected to allow the opening of the intake valve and the exhaust valve. first and second valve opening permission signal generation means for respectively outputting an intake valve opening permission signal and an exhaust valve opening permission signal indicating a period; An intake/exhaust valve control comprising first and second gate circuits that input a control signal to the drive means and output a control signal included within the period in which the valve opening is allowed as an actual signal. Device.