A speed threshold device, engine

Abstract

The application discloses a speed threshold device, wherein the speed threshold device comprises a speed acquisition module, a signal amplification module, a frequency-voltage conversion module and a threshold output module; the output end of the speed acquisition module is connected with the input end of the signal amplification module; the signal amplification module receives the output signal of the speed acquisition module and amplifies the output signal; the signal amplification module transmits the amplified signal to the frequency-voltage conversion module; the frequency-voltage conversion module is used for converting the frequency signal into a voltage signal; and the threshold output module is used for controlling the working state of the engine according to the voltage signal output by the frequency-voltage conversion module. The speed threshold device provided by the application adopts digital logic such as signal amplification and frequency-voltage conversion to process the speed threshold, finally realizes the control of the working state of the engine, and avoids the complicated authentication process of using programs to realize the speed threshold control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine control, and in particular to a speed threshold device and an engine. BACKGROUND

[0002] The engine speed is an important indicator of the engine operating state, and the speed threshold device can monitor the engine speed and has an important role in the control of the engine.

[0003] At present, the speed threshold device generally uses a single-chip microcomputer, and the function of the speed threshold device is realized based on a single-chip microcomputer program. When the speed threshold device is used in a high-safety situation, very complex software authentication is required. SUMMARY

[0004] The present application provides a speed threshold device to solve the problem that the existing speed threshold device requires a complex authentication process.

[0005] According to an aspect of the present application, a speed threshold device is provided, which comprises a speed acquisition module, a signal amplification module, a frequency-voltage conversion module and a threshold output module.

[0006] The output end of the speed acquisition module outputs a speed signal, the output end of the speed acquisition module is connected to the input end of the signal amplification module, the signal amplification module receives the output signal of the speed acquisition module and amplifies the output signal, the output end of the signal amplification module is connected to the input end of the frequency-voltage conversion module, the signal amplification module transmits the amplified signal to the frequency-voltage conversion module, and the frequency-voltage conversion module is used to convert a frequency signal into a voltage signal; the output end of the frequency-voltage conversion module is connected to the input end of the threshold output module, and the threshold output module is used to control the working state of the engine according to the voltage signal output by the frequency-voltage conversion module.

[0007] Optionally, the signal amplification module comprises a first operational amplifier, a first resistance module, a second resistance module and a third resistance module; the first resistance module is connected between the positive input end and the output end of the first operational amplifier, the negative input end of the first operational amplifier is connected to a first power supply through the second resistance module, the negative input end of the first operational amplifier is grounded through the third resistance module, and the output end of the first operational amplifier is connected to the input end of the frequency-voltage conversion module.

[0008] Optionally, the frequency-voltage conversion module comprises a frequency-voltage converter, a fourth resistor module, a fifth resistor module, a sixth resistor module, a first capacitor, a second capacitor and a first variable resistor module; a positive comparison input end of the frequency-voltage converter is connected to an output end of the signal amplification module, a negative comparison input end of the frequency-voltage converter is connected to a connection point of one end of the fourth resistor module and one end of the fifth resistor module, the other end of the fourth resistor module is connected to a first power supply, and the other end of the fifth resistor module is grounded; an output end of the frequency-voltage converter is connected to one end of the sixth resistor module and one end of the first capacitor, the other end of the first capacitor is grounded, the other end of the sixth resistor module is grounded, one end of the first variable resistor module is connected to the negative input end of the frequency-voltage converter, the other end of the first variable resistor module is grounded, and the second capacitor is used as a charging pump timing capacitor of the frequency-voltage converter.

[0009] Optionally, the speed threshold device further comprises a second operational amplifier and a third capacitor; a positive input end of the second operational amplifier is connected to an output end of the frequency-voltage converter, the positive input end of the second operational amplifier is grounded through the third capacitor, and an output end of the second operational amplifier is connected to an input end of the threshold output module.

[0010] Optionally, the speed threshold device further comprises a display module connected to the output end of the second operational amplifier, for displaying the rotating speed in real time.

[0011] Optionally, the threshold output module comprises a voltage comparison unit and a switch control unit; an input end of the voltage comparison unit is connected to an input end of the threshold output module and receives a voltage signal output by the second operational amplifier, the voltage comparison unit outputs a square wave signal according to the input voltage signal and a preset voltage signal, an output end of the voltage comparison unit is connected to an input end of the switch control unit, an output end of the switch control unit is connected to an output end of the threshold output module, and the switch control unit is turned on or turned off according to the voltage signal output by the voltage comparison unit.

[0012] Optionally, the voltage comparison unit comprises a third operational amplifier, an eleventh resistance module, a twelfth resistance module, a thirteenth resistance module and a third variable resistance module; the positive input end of the third operational amplifier is connected with the input end of the threshold output module through the eleventh resistance module, the twelfth resistance module is connected between the positive input end and the output end of the third operational amplifier, and the output end of the third operational amplifier is connected with the input end of the switch control unit through the thirteenth resistance module; the third variable resistance module is connected between the first power supply and the ground end, the adjusting end of the variable resistance is connected with the negative input end of the third operational amplifier, and the voltage input into the negative input end of the third operational amplifier is used as the reference voltage of the voltage comparator.

[0013] Optionally, the switch control unit comprises a control circuit and a relay; the control circuit comprises a fourteenth resistance module, a fifteenth resistance module, a sixteenth resistance module, a seventeenth resistance module, an eighteenth resistance module, a nineteenth resistance module, a twentieth resistance module, a twenty-first resistance module, a first triode, a second triode, a first diode, a second diode, a third diode and a light-emitting diode; one end of the fourteenth resistance module is connected with the output end of the voltage comparison unit, the other end of the fourteenth resistance module is connected with the base of the first triode through the fifteenth resistance module, the emitter of the first triode is grounded, and the sixteenth resistance module is connected between the base and the emitter of the first triode; the collector of the first triode is connected with the anode of the light-emitting diode through the seventeenth resistance module, the cathode of the light-emitting diode is connected with the collector of the second triode through the eighteenth resistance module, the emitter of the second triode is grounded, the nineteenth resistance module is connected between the emitter and the base of the second triode, the base of the second triode is connected with the cathode of the first diode and the cathode of the second diode respectively, the anode of the first diode is connected with the collector of the first triode, the anode of the second diode is connected with one end of the twentieth resistance module, and the other end of the twentieth resistance module is connected with the output end of the voltage comparison unit through the twenty-first resistance module; the cathode of the third diode is connected with the anode of the light-emitting diode, the anode of the third diode is connected with the collector of the second triode, and the anode of the light-emitting diode is connected with the second power supply; the control coil of the relay is connected in parallel across the third diode.

[0014] Optionally, the threshold output module is 6, which is a parking speed threshold output module, a first throttle limit speed threshold output module, a second throttle limit speed threshold output module, a starting solenoid valve speed threshold output module, an engine excitation switch speed threshold output module and an overspeed protection speed threshold output module.

[0015] According to another aspect of the present application, there is provided an engine comprising the speed threshold device.

[0016] The speed threshold device provided by the embodiment of the present application comprises a speed acquisition module, a signal amplification module, a frequency-voltage conversion module and a threshold output module. The output end of the speed acquisition module is connected to the input end of the signal amplification module. The signal amplification module receives the output signal of the speed acquisition module and amplifies the output signal. The signal amplification module transmits the amplified signal to the frequency-voltage conversion module. The frequency-voltage conversion module is used to convert the frequency signal into a voltage signal. The threshold output module is used to control the working state of the engine according to the voltage signal output by the frequency-voltage conversion module. The speed threshold device provided by the present application adopts digital logic such as signal amplification and frequency-voltage conversion to process the speed threshold, and finally realizes the control of the working state of the engine, avoiding the cumbersome authentication process of using program to realize the speed threshold control.

[0017] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0019] Figure 1 is a speed threshold device structure schematic diagram provided by the embodiment of the present application;

[0020] Figure 2 is a circuit diagram of the signal amplification module 120 provided by the embodiment of the present application;

[0021] Figure 3 is a circuit diagram of the frequency-voltage conversion module 130 provided by the embodiment of the present application;

[0022] Figure 4 is a second operational amplifier and peripheral circuit diagram provided by the embodiment of the present application;

[0023] Figure 5 is a structure diagram of a threshold output module provided by the embodiment of the present application;

[0024] Figure 6 is a circuit diagram of a voltage comparison unit provided by the embodiment of the present application;

[0025] Figure 7 is a circuit diagram of a switch control unit provided by the embodiment of the present application;

[0026] Figure 8 is a circuit diagram of a speed threshold device provided by the embodiment of the present application;

[0027] Figure 9 is another structure diagram of a speed threshold device provided by the embodiment of the present application;

[0028] Figure 10 is a structure diagram of an engine provided by the embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiment of the present application will be described clearly and completely below in combination with the drawings in the embodiment of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the scope of protection of the present application.

[0030] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0031] Figure 1 is a structure diagram of a speed threshold device provided by the embodiment of the present application, as Figure 1As shown, the speed threshold device 100 includes a speed acquisition module 110, a signal amplification module 120, a frequency-voltage conversion module 130, and a threshold output module 140; the output end of the speed acquisition module 110 outputs a speed signal, the output end of the speed acquisition module 110 is connected to the input end of the signal amplification module 120, the signal amplification module 120 receives the output signal of the speed acquisition module 110 and amplifies the output signal of the speed acquisition module 110; the output end of the signal amplification module 120 is connected to the input end of the frequency-voltage conversion module 130, the signal amplification module 120 transmits the amplified signal to the frequency-voltage conversion module 130, and the frequency-voltage conversion module 130 is used to convert the frequency signal into a voltage signal; the output end of the frequency-voltage conversion module 130 is connected to the input end of the threshold output module 140, and the threshold output module 140 is used to control the working state of the engine according to the voltage signal output by the frequency-voltage conversion module 130.

[0032] In this embodiment, the speed threshold device is a speed control device, which controls the speed by comparing the actual speed with the preset threshold value. When the speed threshold device is applied to the engine, the speed of the engine can be detected in real time, and the working state of the engine can be controlled. The speed acquisition module 110 acquires the actual speed of the engine and converts the speed signal into an alternating current signal, for example, the speed acquisition module 110 can be a speed sensor, etc. The signal amplification module 120 is used to amplify the input signal to ensure that the amplified frequency signal can be recognized by the frequency-voltage conversion module 130. The frequency-voltage conversion module 130 is used to convert the frequency signal into a voltage signal, i.e. to convert the alternating current signal into a direct current signal. The threshold output module 140 realizes the output or shutdown of the output end signal by comparing the voltage input by the input end with the preset threshold value.

[0033] When the current speed detected by the speed threshold device is not greater than the preset threshold value, the speed acquisition module 110 acquires the current running speed and transmits the acquired speed signal to the signal amplification module 120, the signal amplification module 120 amplifies the input frequency signal and transmits the amplified signal to the frequency-voltage conversion module 130, the frequency-voltage conversion module 130 converts the input alternating current signal into a direct current signal and inputs the output direct current signal to the threshold output module 140, at this time, the threshold output module 140 outputs the output signal of the output end; when the current speed detected by the speed threshold device is greater than the preset threshold value, the speed acquisition module 110 acquires the current running speed and transmits the acquired speed signal to the signal amplification module 120, the signal amplification module 120 amplifies the input frequency signal and transmits the amplified signal to the frequency-voltage conversion module 130, the frequency-voltage conversion module 130 converts the input alternating current signal into a direct current signal and inputs the output direct current signal to the threshold output module 140, at this time, the threshold output module 140 outputs the output signal of the output end. shutdown, i.e. there is no signal output at the output end of the threshold output module 140.

[0034] The speed threshold device provided by the embodiment comprises a speed acquisition module, a signal amplification module, a frequency-voltage conversion module and a threshold output module; an output end of the speed acquisition module is connected to an input end of the signal amplification module, the signal amplification module receives an output signal of the speed acquisition module and amplifies the output signal; the signal amplification module transmits the amplified signal to the frequency-voltage conversion module, the frequency-voltage conversion module is used for converting a frequency signal into a voltage signal; and the threshold output module is used for controlling a working state of an engine according to the voltage signal output by the frequency-voltage conversion module. The speed threshold device provided by the embodiment adopts digital logic such as signal amplification and frequency-voltage conversion to process a speed threshold, and finally realizes control on the working state of the engine. The embodiment adopts a digital logic device to replace a speed threshold device designed by program software, and thus complex software authentication is not needed, and a cumbersome authentication process for realizing speed threshold control by using a program is avoided.

[0035] In the embodiment, Figure 2 is a circuit diagram of the signal amplification module 120 provided by the embodiment, as Figure 2 shown, the signal amplification module 120 comprises a first operational amplifier U1, a first resistance module R1, a second resistance module R2 and a third resistance module R3; the first resistance module R1 is connected between a positive input end and an output end of the first operational amplifier U1, a negative input end of the first operational amplifier U1 is connected to a first power supply V1 through the second resistance module R2, the negative input end of the first operational amplifier U1 is grounded through the third resistance module R3, and an output end a1 of the first operational amplifier U1 is connected to an input end of the frequency-voltage conversion module. The first power supply V1 can be a 15V power supply, the first operational amplifier U1 is used for amplifying a speed signal of the positive input end, for example, the first operational amplifier U1 can be an LM2092, and this is not limited.

[0036] In the embodiment, Figure 3 is a circuit diagram of the frequency-voltage conversion module 130 provided by the embodiment, as Figure 3As shown, the frequency-voltage conversion module 130 comprises a frequency-voltage converter U2, a fourth resistance module R4, a fifth resistance module R5, a sixth resistance module R6, a first capacitor C1, a second capacitor C2 and a first variable resistance module r1; wherein the frequency-voltage converter U2 can be selected from LM2907, and the positive comparison input end (i.e. the pin TACH+) of the frequency-voltage converter U2 is connected to the output end of the signal amplification module 120, the negative comparison input end (i.e. the pin TACH-) of the frequency-voltage converter U2 is connected to the connection point of one end of the fourth resistance module R4 and one end of the fifth resistance module R5, the other end of the fourth resistance module R4 is connected to the first power supply V1, and the other end of the fifth resistance module R5 is grounded; the output end of the frequency-voltage converter U2 is connected to one end of the sixth resistance module R6 and one end of the first capacitor C1, the other end of the first capacitor C1 is grounded, the other end of the sixth resistance module R6 is grounded, one end of the first variable resistance module r1 is connected to the negative input end (i.e. the pin IN-) of the frequency-voltage converter U2, the other end of the first variable resistance module r1 is grounded, and the second capacitor C2 is used as a charging pump timing capacitor of the frequency-voltage converter U2.

[0037] On the basis of the above embodiment, the speed threshold device further comprises a second operational amplifier U3 and a third capacitor C3; the positive input end of the second operational amplifier U3 is connected to the output end (i.e. the pin CP2) of the frequency-voltage converter, the positive input end of the second operational amplifier U3 is grounded through the third capacitor C3, and the output end a2 of the second operational amplifier U3 is connected to the input end a3 of the threshold output module. Figure 4 The second operational amplifier and peripheral circuit diagram provided by the embodiment of the present application is shown in FIG. 2. Figure 4 As shown, the second operational amplifier U3 further comprises a seventh resistance module R7, an eighth resistance module R8, a ninth resistance module R9, a tenth resistance module R10, a second variable resistance module r2 and a fourth capacitor C4; the seventh resistance module R7 and the eighth resistance module R8 are connected in series at the output end (i.e. the pin CP2) of the frequency-voltage converter and the positive input end of the second operational amplifier U3, one end of the fourth capacitor C4 is connected to the connection point of the seventh resistance module R7 and the eighth resistance module R8, the other end of the fourth capacitor C4 is connected to one end of the ninth resistance module R9, the other end of the ninth resistance module R9 is connected to the positive input end (i.e. the pin IN+) of the frequency-voltage converter U2, and at the same time, the other end of the ninth resistance module R9 is connected to the second variable resistance module r2 through the tenth resistance module R10.

[0038] In the embodiment, the speed threshold device further comprises a display module connected to the output end of the second operational amplifier U3, which is used for displaying the rotating speed in real time. The display module can supervise the speed threshold device by displaying the current rotating speed.

[0039] Figure 5 The structure diagram of the threshold output module provided by the embodiment of the present application is shown in FIG. 3.Figure 5 As shown in the figure, the threshold output module 140 comprises a voltage comparison unit 510 and a switch control unit 520; an input end of the voltage comparison unit 510 is connected to an input end a3 of the threshold output module 140 and receives a voltage signal output by the second operational amplifier U3, the voltage comparison unit 510 outputs a square wave signal according to the input voltage signal and a preset voltage signal, an output end a4 of the voltage comparison unit 510 is connected to an input end a5 of the switch control unit 520, an output end of the switch control unit 520 is connected to an output end of the threshold output module, and the switch control unit 520 is turned on or turned off according to the voltage signal output by the voltage comparison unit 510. Wherein, the square wave signal can be represented by a high level signal and a low level signal, when the voltage signal input by the voltage comparison unit 510 is greater than the preset voltage signal, the voltage comparison unit 510 outputs a high level signal, and the switch control unit 520 is turned on according to the voltage signal output by the voltage comparison unit 510, when the voltage signal input by the voltage comparison unit 510 is not greater than the preset voltage signal, the voltage comparison unit 510 outputs a low level signal, and the switch control unit 520 is turned off according to the voltage signal output by the voltage comparison unit 510.

[0040] As shown in the figure, Figure 6 is a circuit diagram of the voltage comparison unit provided by the embodiment of the present application, as shown in the figure, Figure 6 As shown in the figure, the voltage comparison unit 510 comprises a third operational amplifier U4, an eleventh resistance module R11, a twelfth resistance module R12, a thirteenth resistance module R13 and a third variable resistance module r3; a positive input end of the third operational amplifier U4 is connected to the input end a3 of the threshold output module through the eleventh resistance module R11, the twelfth resistance module R12 is connected between the positive input end and the output end of the third operational amplifier U4, and the output end of the third operational amplifier U4 is connected to the output end a4 of the voltage comparison unit 510 through the thirteenth resistance module R13; the third variable resistance module r3 is connected between a first power supply V1 and a ground end, an adjusting end of the third variable resistance module r3 is connected to a negative input end of the third operational amplifier U4, for outputting an adjusted voltage, and the voltage input to the negative input end of the third operational amplifier U4 is used as a reference voltage of the voltage comparator.

[0041] Figure 7 is a circuit diagram of the switch control unit provided by the embodiment of the present application, as shown in the figure, Figure 7 As shown in the figure, the switch control unit 520 comprises a control circuit and a relay; the control circuit comprises a fourteenth resistance module R14, a fifteenth resistance module R15, a sixteenth resistance module R16, a seventeenth resistance module R17, an eighteenth resistance module R18, a nineteenth resistance module R19, a twentieth resistance module R20, a twenty-first resistance module R21, a first triode T1, a second triode T2, a first diode D1, a second diode D2, a third diode D3 and a light emitting diode DE1.

[0042] In the embodiment, one end of the fourteenth resistance module R14 is connected with the input end a5 of the switch control unit 520, the other end of the fourteenth resistance module R14 is connected with the base of the first triode T1 through the fifteenth resistance module R15, the emitter of the first triode T1 is grounded, the sixteenth resistance module R16 is connected between the base and the emitter of the first triode T1; the collector of the first triode T1 is connected with the anode of the light emitting diode DE1 through the seventeenth resistance module R17, the cathode of the light emitting diode DE1 is connected with the collector of the second triode T2 through the eighteenth resistance module R18, the emitter of the second triode T2 is grounded, the nineteenth resistance module R19 is connected between the emitter and the base of the second triode T2, the base of the second triode T2 is connected with the cathode of the first diode D1 and the cathode of the second diode D2 respectively, the anode of the first diode D1 is connected with the collector of the first triode T1, the anode of the second diode D2 is connected with one end of the twentieth resistance module R20, the other end of the twentieth resistance module R20 is connected with the input end a5 of the switch control unit 520 through the twenty-first resistance module R21; the cathode of the third diode D3 is connected with the anode of the light emitting diode DE1, the anode of the third diode D3 is connected with the collector of the second triode T2, the anode of the light emitting diode DE1 is connected with the second power supply V2; the control coil of the relay K is connected in parallel between the two ends of the third diode D3.

[0043] In the embodiment, in the switch control unit 520, the control circuit of the relay is connected, the control circuit realizes the conduction or the shutdown according to the square wave signal output by the voltage comparison unit 510, when the control circuit is conducted, the relay coil is powered, the relay contact is closed, when the control circuit is shut down, the relay coil loses power, and the relay contact is opened. The switch control unit 520 realizes the output or the shutdown of the output end signal through the closing or the opening of the relay contact.

[0044] Figure 8 is a circuit diagram of a speed threshold device provided by the embodiment of the application, as shown in Figure 8 The speed threshold device further includes a twenty-second resistance module R22, a twenty-third resistance module R23, a fourth diode D4 and a fifth diode D5. The output end of the speed acquisition module 110 is connected with one end of the twenty-second resistance module R2, the other end of the twenty-second resistance module R2 is connected with the anode of the fourth diode D4 and the cathode of the fifth diode D5, the cathode of the fourth diode D4 is connected with the first power supply V1, the anode of the fifth diode D5 is grounded, and the twenty-third resistance module R23 is connected between the cathode and the anode of the fifth diode D5.

[0045] The speed signal outputted by the output end of the speed acquisition module 110 is transmitted to the input end of the signal amplification module 120 through the twenty-second resistance module R22, the output end of the signal amplification module 120 is connected with the frequency-voltage conversion module 130, the frequency-voltage conversion module 130 converts the frequency signal into a voltage signal and outputs the voltage signal through the output end, the voltage signal outputted by the frequency-voltage conversion module 130 is transmitted to the threshold output module 140 through the second operational amplifier U3, and the voltage comparison unit 510 in the threshold output module 140 outputs a high level signal or a low level signal according to the inputted voltage signal and a preset voltage signal, so as to control the output of the on-off control unit 520.

[0046] On the basis of the above-mentioned embodiments, Figure 9 is another structure schematic diagram of the speed threshold device provided by the embodiment of the application, as shown in Figure 9 The threshold output module is 6, which are a parking speed threshold output module for controlling the engine parking state, a first throttle limit value speed threshold output module for controlling the first throttle state, a second throttle limit value speed threshold output module for controlling the second throttle state, a starting electromagnetic valve speed threshold output module for controlling the state of the starting electromagnetic valve, an engine excitation switch speed threshold output module for controlling the state of the engine excitation switch, and an overspeed protection speed threshold output module for controlling the overspeed protection function of the engine.

[0047] In the embodiment, the speed sensor is used as the speed acquisition module to acquire the speed signal, the preamplifier is used as the signal amplification module to amplify the acquired speed signal, the frequency-voltage converter can convert the frequency signal into a voltage signal u, in the threshold output module, by comparing the inputted voltage signal with the preset threshold voltage (u1, u2, u3, u4, u5, u6 respectively), when the inputted voltage signal u is greater than the preset threshold voltage, the threshold output module outputs a signal (threshold 1, threshold 2, threshold 3, threshold 4, threshold 5, threshold 6 respectively). The tachometer is used as the display module and is connected with the frequency-voltage converter, for displaying the speed in real time.

[0048] Figure 10 is a structure schematic diagram of an engine provided by the embodiment of the application, as shown in Figure 10 The engine 10 comprises the speed threshold device 100.

[0049] The embodiment is equipped with a speed threshold device on the engine, which can detect the rotating speed of the engine in real time and control the working state of the engine. The speed acquisition module in the speed threshold device acquires the actual rotating speed of the engine, converts the rotating speed signal into a frequency signal, the signal amplification module amplifies the frequency signal, the frequency-voltage conversion module converts the frequency signal into a voltage signal, and the threshold output module in the speed threshold device compares the actual voltage signal with the preset threshold to make the threshold output module output an output signal or a shutdown signal. The speed threshold device can be equipped with multiple threshold outputs to control different speed thresholds of the engine.

[0050] It should be understood that the various forms of flow shown above can be reordered, added to, or deleted from, for example. The steps described in the present application can be executed in parallel, in series, or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, and the present application is not limited herein.

[0051] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A speed threshold device, characterized in that, include: Speed ​​acquisition module, signal amplification module, frequency-to-voltage conversion module, and threshold output module; The speed acquisition module outputs a speed signal at its output terminal. The output terminal of the speed acquisition module is connected to the input terminal of the signal amplification module. The signal amplification module receives the output signal from the speed acquisition module and amplifies it. The output terminal of the signal amplification module is connected to the input terminal of the frequency-to-voltage conversion module. The signal amplification module transmits the amplified signal to the frequency-to-voltage conversion module, which converts the frequency signal into a voltage signal. The output terminal of the frequency-to-voltage conversion module is connected to the input terminal of the threshold output module. The threshold output module controls the engine's operating state based on the voltage signal output by the frequency-to-voltage conversion module. The frequency-to-voltage conversion module includes a frequency-to-voltage converter. The speed threshold device further includes a second operational amplifier, a third capacitor, a seventh resistor module, an eighth resistor module, a ninth resistor module, a tenth resistor module, a second variable resistor module, and a fourth capacitor. The positive input terminal of the second operational amplifier is connected to the output terminal of the frequency-to-voltage converter, and the positive input terminal of the second operational amplifier is grounded through the third capacitor. The output terminal of the second operational amplifier is connected to the input terminal of the threshold output module. The seventh resistor module and the eighth resistor module are connected in series between the output terminal of the frequency-to-voltage converter and the positive input terminal of the second operational amplifier. One end of the fourth capacitor is connected to the connection point of the seventh resistor module and the eighth resistor module, and the other end of the fourth capacitor is connected to one end of the ninth resistor module. The other end of the ninth resistor module is connected to the positive input terminal of the frequency-to-voltage converter, and the other end of the ninth resistor module is connected to the second variable resistor module through the tenth resistor module.

2. The speed threshold device according to claim 1, characterized in that, The signal amplification module includes a first operational amplifier, a first resistor module, a second resistor module, and a third resistor module. The first resistor module is connected between the positive input terminal and the output terminal of the first operational amplifier. The negative input terminal of the first operational amplifier is connected to a first power supply through the second resistor module. The negative input terminal of the first operational amplifier is grounded through the third resistor module. The output terminal of the first operational amplifier is connected to the input terminal of the frequency-to-voltage conversion module.

3. The speed threshold device according to claim 1, characterized in that, The frequency-to-voltage conversion module further includes a fourth resistor module, a fifth resistor module, a sixth resistor module, a first capacitor, a second capacitor, and a first variable resistor module. The positive comparison input terminal of the frequency-to-voltage converter is connected to the output terminal of the signal amplification module. The negative comparison input terminal of the frequency-to-voltage converter is connected to the connection point between one end of the fourth resistor module and one end of the fifth resistor module. The other end of the fourth resistor module is connected to a first power supply, and the other end of the fifth resistor module is grounded. The output terminal of the frequency-to-voltage converter is connected to one end of the sixth resistor module and one end of the first capacitor. The other end of the first capacitor is grounded, and the other end of the sixth resistor module is grounded. One end of the first variable resistor module is connected to the negative input terminal of the frequency-to-voltage converter, and the other end of the first variable resistor module is grounded. The second capacitor serves as the charging pump timing capacitor of the frequency-to-voltage converter.

4. The speed threshold device according to claim 1, characterized in that, It also includes a display module, which is connected to the output of the second operational amplifier and is used to display the rotational speed in real time.

5. The speed threshold device according to claim 1, characterized in that, The threshold output module includes a voltage comparison unit and a switch control unit. The input terminal of the voltage comparison unit is connected to the input terminal of the threshold output module and receives the voltage signal output by the second operational amplifier. The voltage comparison unit outputs a square wave signal based on the input voltage signal and a preset voltage signal. The output terminal of the voltage comparison unit is connected to the input terminal of the switch control unit. The output terminal of the switch control unit is connected to the output terminal of the threshold output module. The switch control unit turns the module on or off based on the voltage signal output by the voltage comparison unit.

6. The speed threshold device according to claim 5, characterized in that, The voltage comparison unit includes a third operational amplifier, an eleventh resistor module, a twelfth resistor module, a thirteenth resistor module, and a third variable resistor module; the positive input terminal of the third operational amplifier is connected to the input terminal of the threshold output module through the eleventh resistor module, the twelfth resistor module is connected between the positive input terminal and the output terminal of the third operational amplifier, and the output terminal of the third operational amplifier is connected to the input terminal of the switch control unit through the thirteenth resistor module. The third variable resistor module is connected between the first power supply and the ground terminal. The adjustment terminal of the variable resistor is connected to the negative input terminal of the third operational amplifier for outputting the adjusted voltage. The voltage input to the negative input terminal of the third operational amplifier serves as the reference voltage for the voltage comparator.

7. The speed threshold device according to claim 6, characterized in that, The switch control unit includes a control circuit and a relay; the control circuit includes a fourteenth resistor module, a fifteenth resistor module, a sixteenth resistor module, a seventeenth resistor module, an eighteenth resistor module, a nineteenth resistor module, a twentieth resistor module, a twenty-first resistor module, a first transistor, a second transistor, a first diode, a second diode, a third diode, and a light-emitting diode; One end of the fourteenth resistor module is connected to the output terminal of the voltage comparator unit, and the other end of the fourteenth resistor module is connected to the base of the first transistor through the fifteenth resistor module. The emitter of the first transistor is grounded. The sixteenth resistor module is connected between the base and emitter of the first transistor. The collector of the first transistor is connected to the anode of the light-emitting diode through the seventeenth resistor module. The cathode of the light-emitting diode is connected to the collector of the second transistor through the eighteenth resistor module. The emitter of the second transistor is grounded. The nineteenth resistor module is connected between the emitter and base of the second transistor. The base of the second transistor is connected to the cathodes of the first diode and the second diode, respectively. The anode of the first diode is connected to the collector of the first transistor. The anode of the second diode is connected to one end of the twentieth resistor module. The other end of the twentieth resistor module is connected to the output terminal of the voltage comparator unit through the twenty-first resistor module. The cathode of the third diode is connected to the anode of the light-emitting diode. The anode of the third diode is connected to the collector of the second transistor. The anode of the light-emitting diode is connected to the second power supply. The control coil of the relay is connected in parallel across the third diode.

8. The speed threshold device according to any one of claims 1-7, characterized in that, The threshold output modules consist of six modules: a parking speed threshold output module for controlling the engine parking state; a first throttle limit speed threshold output module for controlling the first throttle state; a second throttle limit speed threshold output module for controlling the second throttle state; a starter solenoid valve speed threshold output module for controlling the starter solenoid valve state; an engine excitation switch speed threshold output module for controlling the engine excitation switch state; and an overspeed protection speed threshold output module for controlling the engine overspeed protection function.

9. An engine, characterized in that, Includes the speed threshold device according to any one of claims 1-8.

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