A hard guard for a motor driven valve

Abstract

The application discloses a hard protection device for motor-driven valves, and belongs to the technical field of piston reciprocating internal combustion engines, and particularly relates to a hard protection device which can timely cut off the power supply of a motor when a valve and a piston collide. The hard protection device utilizes a valve position sensor, a target wheel position sensor and an ECU motor switch to indicate output signals, and the output signals pass through internal logic circuits to protect the engine of the motor-driven valve, and can simply and directly protect the valve, the motor, the piston and the like through a hardware circuit in some dangerous situations.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of piston reciprocating internal combustion engine, and particularly relates to a hard protection device for avoiding collision between a valve and a piston by timely cutting off power supply of a valve motor. BACKGROUND

[0002] The valve of an engine is opened and closed according to a certain working sequence and timing to complete the intake of air and the exhaust of burned gas. The valve of a traditional engine is driven by a timing gear of a crankshaft to drive a timing gear of a camshaft, and then the camshaft drives the opening and closing of the valve. Since the transmission mode is mechanical, the movement law of the valve is fixed. However, the fixed movement law of the valve leads to the fact that the opening and closing time of the valve cannot be changed, and the lift change law of the valve is also fixed. However, the speed and load of the engine are variable, which leads to the fact that the fixed lift change law of the valve cannot make the engine achieve the best power and economy under various working conditions. The valve motor-driven valve technology directly opens or closes the valve by using a motor, and the opening and closing time and the maximum lift of the valve can be changed by the control of the motor. Therefore, the valve timing and the lift size can be adjusted in real time according to the actual speed and load of the engine, so as to improve the performance of the engine and meet the power and emission requirements under various working conditions, and the engine can be more energy-saving and environmentally friendly. However, after the cam driving is cancelled, the connection between the motor and the valve is compared with the mechanical structure of the cam tappet, and the valve cannot move within its safe range of motion due to reasons such as control failure of the motor or ECU caused by violent relative motion and strong electromagnetic interference. When the piston is in the upstroke stage and approaches the top dead center position, if the valve is opened at the same time, the valve and the piston may collide. If the valve is in the closed state and the motor is still dragging the valve, the valve has already tightly contacted with the cylinder head, and the continued dragging of the motor will cause damage to the valve and the cylinder head. Whether it is a collision with the piston or the continued dragging of the closed valve, it will cause a serious accident, and thus the safe operation of the engine cannot be guaranteed. The present application aims to detect the positions of the valve and the piston by using a hardware circuit, timely cut off the power supply of the valve motor to close the valve before the possible collision occurs, and avoid the collision between the valve and the piston. SUMMARY

[0003] The present application provides an independent ECU emergency protection device.

[0004] Advantages:

[0005] 1. The present invention adopts simple circuit logic to detect and judge whether the control motor stops, has simple structure, low cost and obvious effect.

[0006] 2. The present invention can stop the motor in time to ensure engine safety when the motor valve connection fails or the ECU and motor control strategy fails. At the same time, by using two window comparators and setting the high and low reference voltages, it can also prevent accidents at low speeds.

[0007] 3. The present invention has a wide range of applications and is suitable for scenarios where different motors are used to drive valves. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Fig. 1 A schematic diagram of the installation position of a hard protection device for a motor-driven valve;

[0009] Fig. 2 A side view of a target wheel, a rigid protection device for a motor-driven valve;

[0010] Fig. 3 This is a schematic diagram of the ECU connection for a motor-driven valve hard protection device;

[0011] Fig. 4 It is an overall logic circuit of a hard protection device for a motor-driven valve; DETAILED DESCRIPTION

[0012] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings:

[0013] Structural relationship:

[0014] like Figs. 1-4 As shown, the valve position sensor (1) is installed on the intake valve (2) and the exhaust valve (3), the motor (4) is installed on the intake valve (2) and the exhaust valve (3), the intake valve (2) and the exhaust valve (3) are installed on the cylinder sleeve (5), the cylinder sleeve (5) has a piston (6), the piston connecting rod (7) is installed under the piston (6), the piston connecting rod (7) is connected to the crankshaft (8), the end of the crankshaft is connected to the target wheel (9), the target wheel is installed with the 1 and 4 cylinder working signal teeth (10) and the 2 and 3 cylinder working signal teeth (11), the target wheel position sensor (12) is installed above the target wheel (9) in the vertical direction, the signal input end of the logic circuit (13) is composed of the valve position sensor (1), the target wheel position sensor (12), and the ECU motor switch indicator (14), and the output end of the logic circuit (13) is connected to the motor protection switch (15).

[0015] The first window comparator C11&C12 input end in the No.1 cylinder protection module of the logic circuit (13) is connected with the corresponding valve position sensor (1), the second window comparator C13&C14 input end is connected with the target wheel position sensor (12), the first stage logic gate U11 input end is connected with the first window comparator C11&C12 output end and the second window comparator C13&C14 output end, the second stage logic gate U12 input end is connected with the first stage logic gate output end U12 and the ECU motor switch indicator (14), the second stage logic gate U12 output end is connected with the base of the NPN triode, the motor protection switch (15) is connected with the collector of the NPN triode, the emitter of the NPN triode is grounded, and the circuits of the remaining cylinders are connected in the same way.

[0016] Working principle:

[0017] Taking the No.1 cylinder as an example, under the state that the corresponding motor (4) drives the intake valve (2) and the exhaust valve (3) of the cylinder, the valve position sensor (1) transmits the position pressure signals V L1 , V L2、 V L3、 V L4 of the intake valve (2) and the exhaust valve (3) to the first window comparator C11&C12 of the cylinder protection module, and the high and low reference voltages of the first window comparator C11&C12 are the valve safety position voltages through the voltage reduction of R VH , R VL to the power supply. If the intake valve (2) and the exhaust valve (3) are in the safety position range at this time, the first window comparator C11&C12 will output a low level signal through logic operation, and if the position of the intake valve (2) and the exhaust valve (3) exceeds the safety range at this time, the first window comparator C11&C12 will output a high level signal through logic operation. At the same time, the target wheel position sensor transmits the target wheel (9) position signal V C to the second window comparator C13&C14 of the corresponding cylinder protection module, and the high and low reference voltages of the second window comparator C13&C14 are the target wheel safety position voltages through the voltage reduction of R 11 , R 12 , R 13 , R 14 , R 21 ......R 41 , R 42 , R 43 , R 44A series of resistors to step down the voltage, the high and low reference voltage of the second window comparator C13&C14 is the safe position voltage of the piston (6), if the target wheel (9) rotation angle has not reached the set dangerous position at this time, that is, the piston (6) moves up or down to a certain safe position, the second window comparator C13&C14 will output a low level signal through logical operation, when the target wheel (9) rotates to the set dangerous position, that is, the piston (6) moves up to a certain dangerous position, the second window comparator C13&C14 will output a high level signal through logical operation, when the two window comparators output high level signals at the same time, it means that the intake valve (2) or exhaust valve (3) and piston (6) in the cylinder at this time exist the risk of collision or the intake valve (2) or exhaust valve (3) is disconnected from the motor (4), if the motor (4) is still in working state at this time, the motor protection switch (15) needs to be disconnected immediately to avoid accidents.

[0018] When the first level logic gate U11 receives high level signals output by the two window comparators, it outputs a high level signal through "and" logical operation, through the "and" logic of the first logic gate U11, the first logic gate U11 will only output a high level signal when the intake valve (2) or exhaust valve (3) and piston (6) are in dangerous position at the same time, in other cases, the logic circuit (13) will not disconnect the motor protection switch (15), the first logic gate U11 will output the high level signal to the second level logic gate U12, at the same time, if the motor (4) is in running state, the ECU motor switch indicator (14) outputs a high level signal EM1, when the first level logic gate U11 and the ECU motor switch indicator (14) output high level signals at the same time, it means that the intake valve (2) and exhaust valve (3) exist the risk of collision with the piston (6) at the same time, and the motor (4) is still driving the intake valve (2) and exhaust valve (3), the motor protection switch (15) needs to be disconnected immediately, in addition to this case, when the intake valve (2) and exhaust valve (3) exist the risk of collision with the piston (6) but the motor is not running at this time, it means that the intake valve (2) and exhaust valve (3) may not be closed due to valve timing, etc., at this time, it belongs to normal working condition, the logic circuit (13) will not disconnect the motor protection switch (15), when the second level logic gate U12 outputs a high level signal to the base of the NPN transistor, the NPN transistor is in conducting state at this time, the motor protection switch (15) will be disconnected immediately, so that the motor (4) stops running. BE >0.7V, the NPN transistor is in conducting state, the motor protection switch (15) will be disconnected immediately, so that the motor (4) stops running.

[0019] The working principle of the protection circuit module corresponding to the remaining cylinders is similar to that of the No. 1 cylinder, the target wheel (9) and the 1, 4 cylinder working signal tooth (10) and the 2, 3 cylinder working signal tooth (11) installed thereon can accurately and accurately transmit the working condition of each cylinder to the ECU through the Hall sensor (12), and the ECU will output a corresponding signal to the motor protection switch (15) through the logic circuit (13) to protect the motor (4) and the cylinder.

[0020] The target wheel position sensor (12) transmits to the corresponding cylinder protection module in the form of a digital signal.

Claims

1. A hard guard for an electric motor driven valve, characterized by The valve position sensor (1), intake valve (2), exhaust valve (3), motor (4), cylinder sleeve (5), piston (6), piston connecting rod (7), crankshaft (8), target wheel (9), 1, 4 cylinder signal work tooth (10), 2, 3 cylinder signal work tooth (11), target wheel position sensor (12), logic circuit (13), ECU motor switch indicator (14), motor protection switch (15) are composed of, the valve position sensor (1) is installed on the intake valve (2) and exhaust valve (3), the motor (4) is installed on the intake valve (2) and exhaust valve (3), the intake valve (2) and exhaust valve (3) are installed on the cylinder sleeve (5), the cylinder sleeve (5) has the piston (6), the piston (6) is installed below the piston connecting rod (7), the piston connecting rod (7) is connected to the crankshaft (8), the crankshaft end is connected to the target wheel (9), the target wheel is installed on 1, 4 cylinder work signal tooth (10) and 2, 3 cylinder work signal tooth (11), the target wheel (9) is installed above the target wheel position sensor (12) in the vertical direction, the logic circuit (13) signal input end is composed of the valve position sensor (1), the target wheel position sensor (12), the ECU motor switch indicator (14) together, the logic circuit (13) output end is connected with the motor protection switch (15); The first window comparator C11&C12 input end in the No.1 cylinder protection module in the logic circuit (13) is connected with the corresponding valve position sensor (1), the second window comparator C13&C14 input end is connected with the target wheel position sensor (12), the first stage logic gate U11 input end is connected with the first window comparator C11&C12 output end and the second window comparator C13&C14 output end, the second stage logic gate U12 input end is connected with the first stage logic gate U11 output end and the ECU motor switch indicator (14), the second stage logic gate U12 output end is connected with the base of NPN triode, the motor protection switch (15) is connected with the collector of NPN triode, the emitter of NPN triode is grounded, the rest of the cylinder protection circuit is connected to the corresponding cylinder logic circuit.

2. The rigid guard for an electric motor driven valve as set forth in claim 1, wherein, The logic circuit comprises: The first window comparator C11&C12, the input end is connected with the valve position sensor (1) of the corresponding cylinder and the power supply, the power supply voltage is adjusted to high and low reference voltage through RVH and RVL voltage division, because the safety position of the valve of the four cylinders is the same, the safety voltage value range is 1-3V, so the resistance values of RVH and RVL in the four cylinders are the same; The second window comparator C13&C14, the input end is connected with the target wheel position sensor (12) and the power supply, the power supply voltage is adjusted to high and low reference voltage through R11, R12, R13, R14 voltage division, because the voltage values output by the target wheel position sensor (12) are different when 1, 4 cylinders work and 2, 3 cylinders work, so the resistance values of R11, R12, R13, R14 are different from R21, R22, R23, R24, so the high and low reference voltages of 1, 4 cylinders are set to 4-6V, and the high and low reference voltages of 2, 3 cylinders are set to 1-3V; The first stage logic gate U11 is connected to the output of the first window comparator C11&C12 and the output of the second window comparator C13&C14, and uses "and" logic for operation. The second stage logic gate U12 is connected to the output of the first stage logic gate U11 and the motor switch indicator (14), and uses "and" logic for operation.

3. The hard guard for an electric motor driven valve as set forth in claim 1, wherein, The logic circuit is a corresponding circuit for one cylinder, and a 4-cylinder engine has 4 identical logic circuits. The reference voltage input terminals of the first window comparator C11&C12 and the reference voltage input terminals of the second window comparator C13&C14 of different circuits are connected to the same power supply, and the required reference voltage is adjusted by a voltage divider. The position input terminals of the second window comparator C13&C14 of different circuits are connected to the same target wheel position sensor (12).

4. The hard guard for an electric motor driven valve as set forth in claim 1, wherein, The target wheel position sensor (12) comprises:

1. A 1, 4-cylinder working signal tooth (10) which is directly above the target wheel (9) when the 1, 4-cylinder piston (6) is at the top dead center; 2. A 2, 3-cylinder working signal tooth (11) which is 180 degrees apart from the 1, 4-cylinder working signal tooth and is directly above the target wheel (9) when the 2, 3-cylinder piston (6) is at the top dead center. The 1, 4-cylinder working signal tooth (10) is directly below the target wheel (9). The 1, 4-cylinder working signal tooth and the 2, 3-cylinder working signal tooth are different in height; and a signal processor which outputs a voltage signal to the target wheel position sensor input terminal of the second window comparator C13&C14 in the 1, 4-cylinder logic circuit when the 1, 4-cylinder working signal tooth (10) rotates upward, and outputs a voltage signal to the target wheel position sensor input terminal of the second window comparator C13&C14 in the 2, 3-cylinder logic circuit when the 2, 3-cylinder working signal tooth (11) rotates upward.

5. The hard guard for an electric motor driven valve as set forth in claim 2, wherein, The output signal of the second window comparator C13&C14 changes with the position of the target wheel (9). When the corresponding cylinder working signal tooth on the target wheel (9) rotates to a position where it is possible to hit the intake valve (2) or the exhaust valve (3), a high-level signal is output. When the corresponding cylinder working signal tooth on the target wheel (9) rotates to a position where it is not possible to hit the valve, a low-level signal is output.

6. The hard guard for an electric motor driven valve as set forth in claim 2, wherein, The first stage logic gate U11 changes with the position of the target wheel (9) and the position of the valve. When the intake valve (2) or the exhaust valve (3) is in a dangerous position and the piston (6) is also in a dangerous position, a high-level signal is output.

7. The hard guard for an electric motor driven valve as set forth in claim 1, wherein, The input terminal of the second stage logic gate U12 is connected to the output terminal of the first stage logic gate U11 and the ECU motor switch indicator (14). When the first stage logic gate U11 outputs a high-level signal and the ECU motor switch indicator (14) indicates that the motor is in a working state, the second stage logic gate U12 outputs a driving signal to disconnect the motor protection switch (15).

8. The hard guard for an electric motor driven valve as set forth in claim 1, wherein, The motor protection switch (15) is in an on state when the motor (4) is working normally, and is disconnected when it is working abnormally. It is different from the motor main switch, and plays a role in protecting the motor (4) and ensuring the safe operation of the engine.

9. The rigid guard for an electric motor driven valve as set forth in claim 1, wherein, It is suitable for protecting engines with any motor-driven valve.

Images