CN214851169U

CN214851169U - Preheating switch for diesel engine

Info

Publication number: CN214851169U
Application number: CN202121256722.5U
Authority: CN
Inventors: 殷晨钟; 吕炎; 陈志翔
Original assignee: Jiangsu Gold Electrical Control Technology Co ltd
Current assignee: Jiangsu Gold Electrical Control Technology Co ltd
Priority date: 2021-06-04
Filing date: 2021-06-04
Publication date: 2021-11-23
Anticipated expiration: 2031-06-04

Abstract

The utility model relates to a preheating switch for a diesel engine, which comprises an optical coupling isolation circuit, a first signal processing circuit and a second signal processing circuit, wherein the first signal processing circuit and the second signal processing circuit are used for stabilizing signals; the input port of the first signal processing circuit is used as the input port of the preheating switch; the output port of the first signal processing circuit is connected to the input port of the optical coupling isolation circuit; the output port of the optical coupling isolation circuit is connected to the input port of the second signal processing circuit; the output port of the second signal processing circuit is connected with the switching tube circuit; the switching tube circuit comprises a switching tube element; the control end of the switching tube element receives an output signal of the second signal processing circuit; the first pole and the second pole of the switching tube element are used as output ports of the preheating switch. The utility model discloses a set up first signal processing circuit and second signal processing circuit, convert the specific output voltage of diesel engine storage battery into the less, comparatively stable electric current of numerical value, come the switch-on and turn-off of control switch tube circuit.

Description

Preheating switch for diesel engine

Technical Field

The utility model relates to an electronic circuit field, concretely relates to preheating switch for diesel engine.

Background

The diesel engine is difficult to start due to low temperature in winter in the alpine region. At present, in order to ensure that a diesel engine can be started in time, the diesel engine is usually started and idled at regular time to improve the temperature of the diesel engine, but a large amount of diesel oil needs to be consumed, and the diesel engine is not beneficial to energy conservation and emission reduction.

In the prior art, a preheating device is also used for preheating a diesel engine. The preheating device generally achieves the preheating effect through heating of devices such as an electric heating wire. In order to have a better preheating effect, a large current is generally required to pass through the heating wire. The output voltage of the lead-containing storage battery on the diesel engine is 12V or 24V, which belongs to a weak voltage signal, so that a device capable of controlling large current by using the weak voltage signal is expected to achieve the technical effects. Since the output voltage of the lead-acid battery is 12V or 24V, and is a stable dc voltage, the lead-acid battery may have a voltage drop after a long period of use, and thus the control voltage may be unstable.

SUMMERY OF THE UTILITY MODEL

To the not enough of prior art, the utility model discloses a diesel engine is with preheating switch.

The utility model discloses the technical scheme who adopts as follows:

a preheating switch for a diesel engine comprises an optical coupling isolation circuit, a first signal processing circuit and a second signal processing circuit, wherein the first signal processing circuit and the second signal processing circuit are used for stabilizing signals; the input port of the first signal processing circuit is used as the input port of the preheating switch; the output port of the first signal processing circuit is connected to the input port of the optical coupling isolation circuit; the output port of the optical coupling isolation circuit is connected to the input port of the second signal processing circuit; the output port of the second signal processing circuit is connected with the switching tube circuit; the switching tube circuit comprises a switching tube element; the control end of the switching tube element receives an output signal of the second signal processing circuit; the first pole and the second pole of the switching tube element are used as output ports of the preheating switch.

The further technical scheme is as follows: the switching tube element is an MOS tube, the control end of the switching tube element is a gate pole, the first pole is a source pole, the second pole is a drain pole, or the first pole is a drain pole, and the second pole is a source pole.

The further technical scheme is as follows: the first signal processing circuit is a constant current circuit.

The further technical scheme is as follows: the first signal processing circuit comprises a first triode and a second triode; the first end of the first resistor is connected with the first input end of the preheating switch, the second end of the first resistor is connected with the first pole of the first triode, the second pole of the first triode is connected with the second input end of the preheating switch, and the two ends of the fifth resistor are respectively connected with the base electrode and the second pole of the first triode; the base electrode of the second triode is connected with the first electrode of the first triode, the first electrode of the second triode is connected with the second end of the second resistor, the first end of the second resistor is connected with the first input end of the preheating switch, and the two ends of the fourth resistor are connected in parallel with the first electrode and the second electrode of the second triode; the first end of the third resistor is connected with the first input end of the preheating switch; the second end of the third resistor is used as the first output end of the first signal processing circuit, and the first pole of the second triode is used as the second output end of the first signal processing circuit.

The further technical scheme is as follows: the first signal processing circuit comprises an indicator light for indicating that the current is too large; the indicator light is a light emitting diode; the anode of the indicator light is connected to the second end of the second resistor, and the cathode of the indicator light is connected to the first pole of the second triode.

The further technical scheme is as follows: the second signal processing circuit comprises a third triode and a fourth triode; the base electrode of the third triode is connected with the first output end of the optical coupling isolation circuit; the first end of the sixth resistor is connected with the first output end of the optical coupling isolation circuit; the second end of the sixth resistor is connected with the first pole of the third triode; the second pole of the third triode is connected with the first end of the seventh resistor; the second end of the seventh resistor is connected with the second output end of the optical coupling isolation circuit; the base electrode of the fourth triode is connected with the first output end of the optical coupling isolation circuit; the first pole of the fourth triode is connected with the second end of the sixth resistor; and the second pole of the fourth triode is connected with the second output end of the optical coupling isolation circuit.

The further technical scheme is as follows: the switching tube circuit comprises an eighth resistor; the eighth resistor is connected in series between the control end of the switching tube element and the first output end of the second signal processing circuit.

The further technical scheme is as follows: the switch tube circuit comprises a switch tube reverse connection prevention device; the switch tube reverse connection preventing device comprises a first diode; the anode of the first diode is connected with the second pole of the switching tube element; the cathode of the first diode is connected to the control end of the switching tube element.

The further technical scheme is as follows: the preheating switch also comprises a user side reverse connection prevention device; the user side reverse connection preventing device comprises a second diode; the anode of the second diode is connected with the cathode output end of the preheating switch; the cathode of the second diode is connected with the anode output end of the preheating switch.

The preheating switch of the diesel engine is installed in a series circuit, and an output port of the preheating switch is connected with a user load and a user power supply in series; the input port of the preheating switch is connected with the output signal of the temperature sensor; the user load is the heating wire for preheating.

The utility model has the advantages as follows:

the utility model discloses at first through opto-coupler isolator, separate control end and output, can use the great current signal of more weak voltage signal control, be applicable to the actual output voltage's of diesel engine storage battery the condition, also avoided the danger of operating personnel direct control heavy current.

The utility model discloses a set up first signal processing circuit and second signal processing circuit, convert the specific voltage (12V or 24V) of diesel engine storage battery into the electric current, and stable be that numerical value is less, numerical value is more for stable electric current, come the switch-on and turn-off of control switch tube circuit. In actual work, if give the MOS pipe and exceed 50 mA's electric current, will lead to the MOS pipe to damage, the utility model discloses a set up two signal processing circuit, can stabilize the drive current of MOS pipe below 20 mA.

In addition, after the battery is used for a long time, the output voltage is gradually reduced, so that the output voltage is no longer a standard value, and for the specific situation, in order to not influence the driving capability of the MOS tube, a second signal processing circuit is particularly arranged, so that the voltage is further stabilized.

Drawings

Fig. 1 is a circuit diagram of the present invention.

In the figure: 1. a first signal processing circuit; 11. a first resistor; 12. a second resistor; 13. a third resistor; 14. a fourth resistor; 15. a fifth resistor; 16. a first triode; 17. a second triode; 18. an indicator light; 2. an opto-coupler isolation circuit; 3. a second signal processing circuit; 31. a third triode; 32. a fourth triode; 33. a seventh resistor; 34. a sixth resistor; 35. a capacitor; 4. a switching tube circuit; 41. an eighth resistor; 42. a switching tube element; 43. a first diode; 5. a second diode.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.

Fig. 1 is a circuit diagram of the present invention. As shown in fig. 1, the preheating switch of the diesel engine includes a first signal processing circuit 1, an optical coupling isolation circuit 2, a second signal processing circuit 3 and a switching tube circuit 4.

The input port of the first signal processing circuit 1 serves as the input port of the preheat switch. An output port of the first signal processing circuit 1 is connected to an input port of the optical coupler isolation circuit 2. An output port of the optical coupling isolation circuit 2 is connected to an input port of the second signal processing circuit 3. The output port of the second signal processing circuit 3 is connected with the switching tube circuit 4. The output port of the switching tube circuit 4 is used as the output port of the preheating switch. The first signal processing circuit 1 and the second signal processing circuit 3 are both for stabilizing signals, and specifically, the first signal processing circuit 1 and the second signal processing circuit 3 are both circuits for controlling the current to be constant in a specific numerical range.

The input port of the preheating switch is used for inputting a control signal. The output port of the preheating switch is connected with the user circuit. The first signal processing circuit 1 and the second signal processing circuit 3 are both used for keeping the current constant, and ensuring that the current value is not too large, so as to avoid damaging the switching tube element 42 in the switching tube circuit 4. The optical coupling isolation circuit 2 is used for isolating the control signal from the user circuit and preventing mutual influence between the input end and the output end. The switching tube circuit 4 is used for receiving control signals and switching off or on a user circuit.

In the embodiment shown in fig. 1, the first signal processing circuit 1 is a constant current circuit. The first signal processing circuit 1 comprises a first transistor 16 and a second transistor 17. The first end of the first resistor 11 is connected to the first input end of the preheating switch, the second end of the first resistor 11 is connected to the first pole of the first triode 16, the second pole of the first triode 16 is connected to the second input end of the preheating switch, and the two ends of the fifth resistor 15 are respectively connected to the base and the second pole of the first triode 16. The base of the second triode 17 is connected with the first pole of the first triode 16, the first pole of the second triode 17 is connected with the second end of the second resistor 12, the first end of the second resistor 12 is connected with the first input end of the preheating switch, and the two ends of the fourth resistor 14 are connected in parallel with the first pole and the second pole of the second triode 17. The first end of the third resistor 13 is connected with the first input end of the preheating switch; a second terminal of the third resistor 13 serves as a first output terminal of the first signal processing circuit 1, and a first pole of the second transistor 17 serves as a second output terminal of the first signal processing circuit 1.

In this embodiment, the first transistor 16 and the second transistor 17 are both NPN transistors, the first electrode is a collector, and the second electrode is an emitter. Specifically, the first transistor 16 is a 8050 transistor, and the second transistor 17 is a 2383 transistor. The selection of the two types is suitable for the condition that the input end of the preheating circuit is connected with the storage battery. The output voltage of the diesel engine battery is relatively fixed and is 12V or 24V, and the first signal processing circuit 1 can carry out current stabilization and current limitation on the relatively fixed voltage.

Optionally, the first transistor 16 and the second transistor 17 may also be PNP transistors, where the first electrode is an emitter electrode and the second electrode is a collector electrode.

When the current is small, the base voltage of the second triode 17 is small, the second triode 17 is not conducted, and the output port of the first signal processing circuit 1 outputs the current. When the current is large, due to the existence of the first resistor 11, the base voltage of the second triode 17 becomes large, the second triode 17 is conducted, the output current of the output port of the first signal processing circuit 1 becomes small, and the circuit damage at the later stage caused by the overlarge current can be avoided. Preferably, the first signal processing circuit 1 comprises an indicator light 18 for indicating that the current is excessive. The indicator light 18 is a light emitting diode. The anode of the indicator light 18 is connected to the second end of the second resistor 12, the cathode of the indicator light 18 is connected to the first pole of the second triode 17, and the indicator light 18 is used for prompting the phenomenon of excessive current.

The optical coupling isolation circuit 2 is specifically an optical coupling element, and this is because the voltage value of input is comparatively fixed, so the bearing capacity of optical coupling element also can be expected, and it can to select an optical coupling element that the use parameter is fit for.

The second signal processing circuit 3 is a current stabilizing circuit, and specifically includes a third transistor 31 and a fourth transistor 32. The base of the third triode 31 is connected with the first output end of the optical coupling isolation circuit 2. A first end of the sixth resistor 34 is connected to a first output end of the optical coupler isolation circuit 2. A second terminal of the sixth resistor 34 is connected to the first pole of the third transistor 31. A second pole of the third transistor 31 is connected to a first terminal of a seventh resistor 33. A second end of the seventh resistor 33 is connected to a second output end of the optical coupler isolation circuit 2. The base of the fourth triode 32 is connected with the first output end of the optical coupling isolation circuit 2. A first pole of the fourth transistor 32 is connected to a second terminal of the sixth resistor 34. A second pole of the fourth transistor 32 is connected to the second output terminal of the opto-isolator circuit 2. A capacitor 35 for filtering is also included. The capacitor 35 is connected between the second end of the seventh resistor 33 and the second output end of the optical coupler isolation circuit 2. Two triodes in the second signal processing circuit 3 further stabilize the current of input switch tube circuit, even because the control signal voltage of input end drops, lead to the signal of telecommunication of opto-coupler isolation circuit 2 output unstable, also can make the current of input switch tube circuit 4 relatively stable.

In the embodiment shown in fig. 1, the third transistor 31 is an NPN-type transistor, the first pole being an emitter and the second pole being a collector. The fourth transistor 32 is a PNP transistor, the first electrode is an emitter, and the second electrode is a collector.

The switching tube circuit 4 comprises a switching tube element 42. The control terminal of the switching tube element 42 receives the output signal of the second signal processing circuit 3. The first and second poles of the switching tube element 42 serve as signal output ports. The switching tube circuit 4 comprises an eighth resistor 41. Both ends of the eighth resistor 41 are connected between the control end of the switching tube element 42 and the first output end of the second signal processing circuit 3, respectively. Specifically, the switching element 42 is a MOS transistor, the control terminal of the switching element 42 is a gate, the first electrode is a source, and the second electrode is a drain, or alternatively, the first electrode is a drain and the second electrode is a source.

The switch tube circuit 4 includes a switch tube reverse connection prevention device. The switch tube reverse connection preventing device comprises a first diode 43. The anode of first diode 43 is connected to the second pole of switching tube element 42. The cathode of the first diode 43 is connected to the control terminal of the switching tube element 42. When the switch tube circuit 4 is connected in reverse, the output current of the first output terminal of the second signal processing circuit 3 directly flows through the first diode 43 without driving the switch tube element 42.

Further, the preheating switch also comprises a user side reverse connection prevention device. The device for terminal reverse connection prevention includes a second diode 43 and a third diode 5. The third diode 43 prevents the second signal processing circuit 3 from being damaged after the user terminal is reversely connected. The anode of the third diode 43 is connected to the positive output terminal of the preheat switch, and the cathode of the third diode 43 is connected to the second pole of the third triode 31. If the positive and negative poles of the user's power supply are connected reversely, the current will flow away from the branch of the third diode 43, and the anode of the third diode 5 is connected to the negative output terminal of the preheating switch. The cathode of the third diode 5 is connected to the positive output terminal of the preheat switch. If the positive and negative poles of the power supply of the user are connected reversely, the current flows in from the anode of the third diode 5 and flows out from the cathode of the third diode 5, the preheating switch is not influenced, and the damage of the preheating switch is not caused.

The output port of the preheating switch is connected with the user load and the user power supply in series. When the input port of the isolating switch has no control signal, the resistance value of the switching tube circuit 4 is large, the user load is in an open circuit state and does not work, when the input port of the isolating switch has the control signal, the resistance value of the switching tube circuit 4 is rapidly reduced to be in a conducting state, the user load and the user power supply form a closed loop, and the user load can work. The input port of the preheating switch is connected with the output signal of the temperature sensor, the circuit can be controlled to be automatically closed when the temperature is high according to the prior art, and the circuit is switched on when the temperature is low. The user load is an electric heating wire for preheating, and when the user load works, the electric heating wire preheats the diesel engine.

In the utility model shown in fig. 1, the circuit before the 2 input ports of opto-coupler isolation circuit, the numerical value of voltage and electric current is all very little, and operating personnel can directly touch and operating signal, does not have danger, and the circuit after 2 opto-coupler isolation circuit, voltage or electric current are all very big, belong to high current or high voltage circuit, and operating personnel touches and can lead to danger, the utility model discloses keep apart low pressure part and high-pressure part, at first can protect user's load, secondly can reduce the danger of operating personnel contact.

The above description is for the purpose of explanation and not limitation of the invention, which is defined in the claims, and any modifications may be made without departing from the basic structure of the invention.

Claims

1. A preheating switch for a diesel engine is characterized in that: the optical coupler comprises an optical coupler isolation circuit (2), a first signal processing circuit (1) and a second signal processing circuit (3) which are used for stabilizing signals; an input port of the first signal processing circuit (1) is used as an input port of the preheating switch; an output port of the first signal processing circuit (1) is connected to an input port of the optical coupling isolation circuit (2); an output port of the optical coupling isolation circuit (2) is connected to an input port of the second signal processing circuit (3); the output port of the second signal processing circuit (3) is connected with the switching tube circuit (4); the switching tube circuit (4) comprises a switching tube element (42); the control end of the switching tube element (42) receives the output signal of the second signal processing circuit (3); the first and second poles of the switching tube element (42) serve as output ports of the preheat switch.

2. The preheating switch for a diesel engine according to claim 1, characterized in that: the switching tube element (42) is a MOS tube, the control end of the switching tube element (42) is a gate pole, the first pole is a source pole, and the second pole is a drain pole, or the first pole is a drain pole and the second pole is a source pole.

3. The preheating switch for a diesel engine according to claim 1, characterized in that: the first signal processing circuit (1) is a constant current circuit.

4. The preheating switch for a diesel engine according to claim 3, characterized in that: the first signal processing circuit (1) comprises a first triode (16) and a second triode (17); the first end of the first resistor (11) is connected with the first input end of the preheating switch, the second end of the first resistor (11) is connected with the first pole of the first triode (16), the second pole of the first triode (16) is connected with the second input end of the preheating switch, and the two ends of the fifth resistor (15) are respectively connected with the base electrode and the second pole of the first triode (16); the base electrode of the second triode (17) is connected with the first pole of the first triode (16), the first pole of the second triode (17) is connected with the second end of the second resistor (12), the first end of the second resistor (12) is connected with the first input end of the preheating switch, and the two ends of the fourth resistor (14) are connected in parallel with the first pole and the second pole of the second triode (17); the first end of the third resistor (13) is connected with the first input end of the preheating switch; the second end of the third resistor (13) is used as the first output end of the first signal processing circuit (1), and the first pole of the second triode (17) is used as the second output end of the first signal processing circuit (1).

5. The preheating switch for a diesel engine according to claim 4, characterized in that: the first signal processing circuit (1) comprises an indicator light (18) for indicating that the current is excessive; the indicator light (18) is a light emitting diode; the anode of the indicator light (18) is connected to the second end of the second resistor (12), and the cathode of the indicator light (18) is connected to the first pole of the second triode (17).

6. The preheating switch for a diesel engine according to claim 1, characterized in that: the second signal processing circuit (3) comprises a third triode (31) and a fourth triode (32); the base electrode of the third triode (31) is connected with the first output end of the optical coupling isolation circuit (2); a first end of the sixth resistor (34) is connected with a first output end of the optical coupling isolation circuit (2); the second end of the sixth resistor (34) is connected with the first pole of the third triode (31); the second pole of the third triode (31) is connected with the first end of the seventh resistor (33); the second end of the seventh resistor (33) is connected with the second output end of the optical coupling isolation circuit (2); the base electrode of the fourth triode (32) is connected with the first output end of the optical coupling isolation circuit (2); a first pole of the fourth triode (32) is connected with a second end of the sixth resistor (34); and a second pole of the fourth triode (32) is connected with a second output end of the optical coupling isolation circuit (2).

7. The preheating switch for a diesel engine according to claim 1, characterized in that: the switching tube circuit (4) comprises an eighth resistor (41); the eighth resistor (41) is connected in series between the control terminal of the switching tube element (42) and the first output terminal of the second signal processing circuit (3).

8. The preheating switch for a diesel engine according to claim 1, characterized in that: the switch tube circuit (4) comprises a switch tube reverse connection prevention device; the switch tube reverse connection preventing device comprises a first diode (43); the anode of the first diode (43) is connected to the second pole of the switching tube element (42); the cathode of the first diode (43) is connected to the control terminal of the switching tube element (42).

9. The preheating switch for a diesel engine according to claim 1, characterized in that: the preheating switch also comprises a user side reverse connection prevention device; the user side reverse connection preventing device comprises a second diode (5); the anode of the second diode (5) is connected with the negative output end of the preheating switch; the cathode of the second diode (5) is connected with the anode output end of the preheating switch.

10. A series circuit provided with a preheating switch for a diesel engine as set forth in any one of claims 1 to 9, wherein an output port of the preheating switch is connected in series with a user load and a user power supply; the input port of the preheating switch is connected with the output signal of the temperature sensor; the user load is the heating wire for preheating.