Electro-hydraulic servo mechanism for diesel engine speed governor

Abstract

The present application relates to a kind of electro-hydraulic servo mechanism for diesel engine governor, including electro-hydraulic servo valve, mechanical feedback device, the valve core one end of the electro-hydraulic servo valve is connected with proportional solenoid to constitute the electro-hydraulic servo valve with oil port on-off position and opening adjustable;The valve core other end of the electro-hydraulic servo valve is connected with mechanical feedback device, when the speed of diesel engine reaches target value, the mechanical feedback device makes the valve core in middle position.The electro-hydraulic servo valve in the electro-hydraulic servo mechanism of the present application is reaction valve, is connected in series with mechanical hydraulic speed regulating device, is normally open state by power loss, and speed control is carried out by automatic takeover by mechanical hydraulic speed regulating device.

Description

Technical Field

[0001] The invention relates to a diesel engine, in particular to an electro-hydraulic composite speed regulating system for regulating the speed of a diesel engine. Background Art

[0002] In the position-type electronic fuel injection system, the diesel engine speed governor used in critical occasions needs to still have the speed regulation function in the event of power failure, that is, it needs to have power-off redundancy.

[0003] To improve speed regulation accuracy under normal conditions, this type of governor uses electro-hydraulic speed regulation during normal operation and mechanical hydraulic speed regulation during power outages. To ensure seamless transition between these two speed regulation modes during a power outage, an electro-hydraulic servo mechanism for the diesel engine governor is designed. This electro-hydraulic servo mechanism is connected in series with the mechanical hydraulic speed regulation device to achieve power-off redundancy. Summary of the Invention

[0004] The present invention proposes an electro-hydraulic servo mechanism for a diesel engine speed governor, which adopts a reaction valve and is connected in series with a mechanical hydraulic speed control device. When the power is off, the mechanism is in a normally open state, and the mechanical hydraulic speed control device can automatically take over to control the speed. The electro-hydraulic servo mechanism is equipped with a mechanical feedback device. In normal mode (electro-hydraulic speed control), when the diesel engine speed reaches the target value, the mechanical feedback device puts the valve core in the electro-hydraulic servo mechanism in the middle position, increases or decreases the speed set value, and the actual speed of the diesel engine changes accordingly.

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is: an electro-hydraulic servo mechanism for a diesel engine speed governor, comprising an electro-hydraulic servo valve and a mechanical feedback device, wherein one end of the valve core of the electro-hydraulic servo valve is connected to a proportional solenoid to form an electro-hydraulic servo valve with adjustable oil port on-off position and opening; the other end of the valve core of the electro-hydraulic servo valve is connected to the mechanical feedback device, and when the diesel engine speed reaches the target value, the mechanical feedback device places the valve core in the middle position.

[0006] Furthermore, the electro-hydraulic servo mechanism is a reaction valve, which is connected in series with the mechanical hydraulic speed control device. When power is lost, it is in a normally open state, and the mechanical hydraulic speed control device automatically takes over to control the speed.

[0007] Furthermore, the electro-hydraulic servo valve includes a proportional solenoid, a spring A, a valve core, a valve sleeve, and a valve seat. The valve core is installed in the valve seat after matching with the valve sleeve. The lower end of the valve core is sleeved with a spring A and connected to the proportional solenoid; the side of the valve seat is provided with an input port P, an output port A, an oil return port T, and an oil drain port L; the input port P is connected to the oil outlet of the speed regulator oil pump, and the output port A is connected to the mechanical hydraulic oil inlet of the speed regulator.

[0008] Further, the mechanical feedback device comprises a spring B, a reset spring, an adjusting screw, a main feedback rod, a second feedback rod, a spring seat, and a mounting seat. One end of the main feedback rod is connected with an output shaft of a speed regulator servo power cylinder, the other end is connected with the second feedback rod through a rotating pin, the rear end of the second feedback rod is connected with the upper end of the mounting seat through a rotating pin, the adjusting screw is fixedly connected with the second feedback rod, the lower end of the adjusting screw is connected with the spring B through the upper and lower spring seats, the lower end of the lower spring seat is connected with a valve core of an electro-hydraulic servo valve, the front end of the second feedback rod and the lower end of the mounting seat are connected with the reset spring through a fixed pin, and the lower end of the mounting seat is fixedly connected with the valve seat of the electro-hydraulic servo valve through a screw.

[0009] Further, the adjusting screw adjusts the initial compression amount of the spring B, and the locking nut is used to lock the adjusted adjusting screw, and the reset spring is used for resetting and compressing the spring B.

[0010] Further, the speed regulator servo power cylinder acts on the spring B through the main feedback rod, two rotating pins, the second feedback rod, the adjusting screw, the spring seat A.

[0011] Further, when the power is lost, the valve core is at the upper end, the P port is connected with the A port, at this time, the speed regulator servo power cylinder is extended, the valve core is moved downward through the main feedback rod, and when the speed regulator servo power cylinder is extended to the bottom, the valve core is just at the P port and the A port cutoff position.

[0012] Further, when working normally, after a current value is set for the proportional electromagnet, the proportional electromagnet generates a pulling force to move the valve core downward, the flow area of the P port and the A port is reduced, the speed regulator servo power cylinder is extended, the valve core is moved downward through the main feedback rod, when the speed regulator servo power cylinder is moved to the position, the P port is just cut off with the A port, and the spring force of the spring A is equal to the spring force of the spring B + the electromagnetic force of the proportional electromagnet, that is, one current value corresponds to one position of the speed regulator servo power cylinder.

[0013] Further, when the current value is reduced, the spring force of the spring A is greater than the spring force of the spring B + the electromagnetic force of the proportional electromagnet, the valve core is moved upward, the P port is connected with the A port, the speed regulator servo power cylinder is extended, the valve core is moved downward again through the main feedback rod, when the P port and the A port are cut off, the spring force of the spring A is equal to the spring force of the spring B + the electromagnetic force of the proportional electromagnet, and the speed regulator servo power cylinder stops moving.

[0014] Further, when the current value is increased, the spring force of the spring A is less than the spring force of the spring B + the electromagnetic force of the proportional electromagnet, the valve core is moved downward, the A port is connected with the T port, the speed regulator servo power cylinder is retracted, the valve core is moved upward again through the main feedback rod, when the A port and the T port are cut off, the spring force of the spring A is equal to the spring force of the spring B + the electromagnetic force of the proportional electromagnet, and the speed regulator servo power cylinder stops moving.

[0015] The beneficial effects of the present invention are:

[0016] The electro-hydraulic servo mechanism of the present invention adopts a reaction valve, which is normally open when power is lost and can be automatically taken over by the mechanical hydraulic speed control to control the speed; the electro-hydraulic servo mechanism is equipped with a mechanical feedback device. When the diesel engine speed reaches the target value, the mechanical feedback device puts the valve core in the middle position, increases or decreases the speed set value, and the actual speed of the diesel engine changes accordingly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional schematic diagram of the electro-hydraulic servo mechanism for a diesel engine speed governor of the present invention;

[0018] Figure 2 It is a three-dimensional schematic diagram of the electro-hydraulic servo mechanism for a diesel engine speed governor of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] like Figure 1 2, an electro-hydraulic servo mechanism for a diesel engine speed governor proposed in the embodiment of the present invention includes a proportional solenoid 1, a spring A2, a valve core 3, a spring B4, a fixed pin A5, a return spring 6, an adjusting screw 7, a fixed pin B8, a rotating pin A9, a locking nut 10, a main feedback rod 11, a rotating pin B12, a second feedback rod 13, a spring seat A14, a mounting seat 15, a screw 16, a spring seat B17, a valve sleeve 18, and a valve seat 19.

[0021] One end of the valve core 3 of the electro-hydraulic servo valve is connected to the proportional solenoid to form an electro-hydraulic servo valve with adjustable oil port on-off position and opening; the other end of the valve core 3 of the electro-hydraulic servo valve is connected to a mechanical feedback device. When the speed regulation reaches the target value, the feedback device puts the valve core in the middle position.

[0022] The electro-hydraulic servo valve consists of a proportional solenoid 1, a spring A2, a valve core 3, a valve sleeve 18, and a valve seat 19. The valve core 3, mated with the valve sleeve 18, is installed within the valve seat 19. The lower end of the valve core 3 is fitted with a spring A2 and connected to the proportional solenoid 1. The side of the valve seat 19 is equipped with an input port P, an output port A, an oil return port T, and an oil drain port L.

[0023] The input port P of the electro-hydraulic servo valve is connected to the oil outlet of the speed regulator oil pump, and the output port A is connected to the oil inlet of the speed regulator mechanical hydraulic device.

[0024] The mechanical feedback device includes a spring B4, a fixed pin A5, a return spring 6, an adjusting screw 7, a fixed pin B8, a rotating pin A9, a locking nut 10, a main feedback rod 11, a rotating pin B12, a second feedback rod 13, a spring seat A14, a mounting seat 15, a screw 16, and a spring seat B17.

[0025] One end of the main feedback rod 11 is connected to the output shaft of the speed regulator's servo power cylinder. The other end is connected to the second feedback rod 13 via a pivot pin A9. The rear end of the second feedback rod 13 is connected to the upper end of the mounting base 15 via a pivot pin B12. The lower end of the mounting base 15 is fixedly connected to the valve seat of the electro-hydraulic servo valve with a screw 16. The second feedback rod 13 is also fixedly connected to the adjustment screw 7 and secured with a lock nut 10. The lower end of the adjustment screw 7 contacts and connects to the spring seat A14, spring B4, and spring seat B17. The lower end of the spring seat B17 is connected to the valve core 3 of the electro-hydraulic servo valve. The front end of the second feedback rod 13 is connected to the return spring 6 via a fixing pin B8. The other end of the return spring 6 is connected to the fixing pin A5 fixed to the lower end of the mounting base 15.

[0026] The adjusting screw 7 adjusts the initial compression amount of the spring B4, the locking nut 10 is used to lock the adjusting screw 7 after adjustment, and the reset spring 6 is used to reset and tighten the spring B4.

[0027] The speed regulator servo power cylinder acts on the spring B4 through the main feedback rod 11, the rotating pin A9, the rotating pin B12, the second feedback rod 13, the adjusting screw 7, and the spring seat A14.

[0028] When the electro-hydraulic servo valve loses power and is in the normally open state, the speed is controlled and adjusted by the mechanical hydraulic speed control device connected behind the device.

[0029] When the power is off, the valve core 3 is at the upper end, and the P port is connected to the A port. At this time, the servo power cylinder of the speed regulator extends, and the valve core 3 moves downward through the main feedback rod 11. When the servo power cylinder extends to the bottom, the valve core 3 is just cut off from the P port and the A port.

[0030] During normal operation, given a certain current value, the proportional electromagnet 1 generates a pulling force to move the valve core 3 downward, reducing the flow area between the P port and the A port. When the servo power cylinder moves to the right position, the main feedback rod 11 causes the valve core to move downward again, and the P port is just cut off from the A port. That is, one current value corresponds to one position of the servo power cylinder. (1) If the current value is reduced at this time, the spring force of spring A2 is greater than the spring force of spring B4 + the electromagnetic force of the proportional electromagnet 1, the valve core moves upward, the P port is connected to the A port, the servo power cylinder extends, and the valve core 3 moves downward again through the main feedback rod. When the P port and the A port are cut off, the servo power cylinder stops moving; (2) If the current value is increased at this time, the spring force of spring A2 is less than the spring force of spring B4 + the electromagnetic force of the proportional electromagnet 1, the valve core 3 moves downward, the A port is connected to the T port, the servo power cylinder retracts, and the valve core moves upward again through the main feedback rod. When the A port and the T port are cut off, the servo power cylinder stops moving.

Claims

1. An electro-hydraulic servo mechanism for a diesel engine speed governor, characterized in that: It includes an electro-hydraulic servo valve and a mechanical feedback device. One end of the valve core of the electro-hydraulic servo valve is connected to a proportional solenoid to form an electro-hydraulic servo valve with adjustable oil port on-off position and opening; the other end of the valve core of the electro-hydraulic servo valve is connected to a mechanical feedback device. When the diesel engine speed reaches the target value, the mechanical feedback device puts the valve core in the middle position; the electro-hydraulic servo valve in the electro-hydraulic servo mechanism is a reaction valve, which is connected in series with the mechanical hydraulic speed control device. When the power is off, it is in the normally open state, and the mechanical hydraulic speed control device automatically takes over to control the speed.

2. The electro-hydraulic servo mechanism for a diesel engine speed governor according to claim 1, characterized in that: The electro-hydraulic servo valve includes a proportional solenoid, a spring A, a valve core, a valve sleeve, and a valve seat. The valve core is installed in the valve seat after matching with the valve sleeve. The lower end of the valve core is sleeved with a spring A and connected to the proportional solenoid; the side of the valve seat is provided with an input port P, an output port A, an oil return port T, and an oil drain port L; the input port P is connected to the oil outlet of the speed regulator oil pump, and the output port A is connected to the oil inlet of the speed regulator mechanical hydraulic device.

3. The electro-hydraulic servo mechanism for a diesel engine speed governor according to claim 2, characterized in that: The mechanical feedback device includes a spring B, a return spring, an adjusting screw, a main feedback rod, a second feedback rod, a spring seat, and a mounting seat. One end of the main feedback rod is connected to the output shaft of the speed regulator servo power cylinder, and the other end is connected to the second feedback rod through a rotating pin. The rear end of the second feedback rod is connected to the upper end of the mounting seat through a rotating pin. The adjusting screw is fixedly connected to the second feedback rod. The lower end of the adjusting rod contacts the spring B connected through the upper and lower spring seats. The lower end of the lower spring seat is connected to the valve core of the electro-hydraulic servo valve; the return spring is connected between the front end of the second feedback rod and the lower end of the mounting seat through a fixing pin; the lower end of the mounting seat is fixedly connected to the valve seat of the electro-hydraulic servo valve with a screw.

4. The electro-hydraulic servo mechanism for a diesel engine speed governor according to claim 3, characterized in that: The adjusting screw adjusts the initial compression amount of the spring B, and the adjusted adjusting screw is locked with a locking nut. The reset spring is used to reset and compress the spring B.

5. The electro-hydraulic servo mechanism for a diesel engine speed governor according to claim 3, characterized in that: The speed regulator servo power cylinder acts on the spring B through the main feedback rod, two rotating pins, the second feedback rod, the adjusting screw, and the spring seat A.

6. The electro-hydraulic servo mechanism for a diesel engine speed governor according to claim 3, characterized in that: When the power is off, the valve core is at the upper end, and port P is connected to port A. At this time, the speed regulator servo power cylinder extends, and the valve core moves downward through the main feedback rod. When the speed regulator servo power cylinder extends to the bottom, the valve core is exactly at the cut-off position between port P and port A.

7. The electro-hydraulic servo mechanism for a diesel engine speed governor according to claim 3, characterized in that: During normal operation, after the proportional solenoid is set to a current value, the proportional solenoid generates a pulling force to move the valve core downward, closing the flow area between port P and port A, and the speed regulator servo power cylinder extends, causing the valve core to move downward through the main feedback rod. When the speed regulator servo power cylinder moves to its full position, port P is exactly cut off from port A, and the spring force of spring A is equal to the spring force of spring B + the electromagnetic force of the proportional solenoid, that is, one current value corresponds to one position of the speed regulator servo power cylinder.

8. The electro-hydraulic servo mechanism for a diesel engine speed governor according to claim 7, characterized in that: When the current value is reduced, the spring force of spring A is greater than the spring force of spring B + the electromagnetic force of the proportional solenoid, the valve core moves upward, port P is connected to port A, the speed regulator servo power cylinder extends, and the valve core moves downward again through the main feedback rod. When port P and port A are cut off, the spring force of spring A is equal to the spring force of spring B + the electromagnetic force of the proportional solenoid, and the speed regulator servo power cylinder stops moving.

9. The electro-hydraulic servo mechanism for a diesel engine speed governor according to claim 7, characterized in that: When the current value is increased, the spring force of spring A is less than the spring force of spring B + the electromagnetic force of the proportional solenoid, the valve core moves downward, port A is connected to port T, the speed regulator servo power cylinder retracts, and the valve core moves upward again through the main feedback rod. When port A and port T are cut off, the spring force of spring A is equal to the spring force of spring B + the electromagnetic force of the proportional solenoid, and the speed regulator servo power cylinder stops moving.

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