Natural gas engine injection control circuit and system

Abstract

The embodiment of the utility model discloses a natural gas engine injection control circuit and a natural gas engine injection control system. An injection driving circuit in the circuit comprises a high-side injection driving circuit and a plurality of low-side injection driving circuits, the control end of the high-side injection driving circuit is connected with one output end of the injection controller, the driving end of the high-side injection driving circuit is connected with one end of an injection coil in the plurality of nozzles, and the plurality of low-side injection driving circuits are connected with the other end of the injection coil; the output end of the jet power supply circuit is connected with the power end of the high-side jet driving circuit. According to the utility model, the plurality of low-side injection driving circuits share one high-side injection driving circuit, the corresponding low-side injection driving circuit is selected to work according to the injection requirement of the nozzle, the control is flexible and convenient, and the circuit is simple in structure, low in failure rate and low in cost; the injection power supply circuit ensures stable power supply voltage of the injection driving circuit through the first boosted circuit and the second boosted circuit, and effectively prevents the injection driving circuit from being influenced by too low voltage of the injection power supply.

Description

Technical Field

[0001] The embodiments of the utility model relate to the technical field of natural gas engines, and in particular to a natural gas engine injection control circuit and system. Background Art

[0002] As environmental awareness grows, countries around the world are establishing stricter standards for vehicle emissions. This has prompted continuous technological innovation and product substitution in areas such as engine control and fuel sources. Natural gas is the third largest natural energy source after coal and oil, and is abundant in natural reserves. Natural gas not only offers comparable power performance to oil, but also significantly reduces atmospheric pollution. In a natural gas engine, natural gas from a cylinder is pressure-regulated, filtered, and injection-controlled before being injected into a gas mixer. The natural gas and air are then mixed in a specific ratio in the mixer before entering the intake manifold for ignition and combustion.

[0003] Natural gas injection control has a crucial impact on the various performance characteristics of natural gas engines. However, existing natural gas engine injection control schemes still have the following shortcomings: 1. The high-side injection drive circuit in the injection drive circuit uses multiple circuit components such as diodes, which has a complex structure, high cost, and increased failure rate; 2. Different nozzles are independently configured with injection drive circuits, and the injection drive circuit of each nozzle needs to be designed independently, resulting in a relatively complex hardware structure and control process for natural gas engine injection control, and high product and production costs; 3. The injection power supply circuit only has one boost circuit to generate a drive voltage to power the high-side injection drive circuit of the injection drive circuit, and the other power supply of the high-side injection drive circuit is directly taken from the injection power supply. During the current holding stage, the drive voltage of the high-side injection drive circuit is affected by the injection power supply voltage and the stray inductance of the power supply circuit. Moreover, when the injection power supply is fed, the injection drive circuit will be affected by the low voltage of the injection power supply and cannot provide sufficient energy, resulting in failure of the natural gas engine injection control system.

[0004] The above problems need to be solved urgently. Utility Model Content

[0005] In order to solve the related technical problems, the present invention provides a natural gas engine injection control circuit and system to solve the problems mentioned in the above background technology section.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a natural gas engine injection control circuit, comprising an injection controller, an injection drive circuit, and an injection power supply circuit; the injection drive circuit comprises one high-side injection drive circuit and N low-side injection drive circuits, wherein N is a positive integer; the control end of the high-side injection drive circuit is connected to an output end of the injection controller, the drive end of the high-side injection drive circuit is connected to one end of the injection coils in a plurality of nozzles, and the N low-side injection drive circuits are connected to the other ends of the injection coils in the plurality of nozzles; the output end of the injection power supply circuit is connected to the power supply end of the high-side injection drive circuit.

[0008] As an optional embodiment, the injection power supply circuit includes a first boost circuit, a second boost circuit and an injection power supply; the input end of the first boost circuit is connected to the input end of the second boost circuit and the output end of the injection power supply, the output end of the first boost circuit is connected to the first power supply end of the high-side injection drive circuit, and the output end of the second boost circuit is connected to the second power supply end of the high-side injection drive circuit.

[0009] As an optional embodiment, the high-side injection drive circuit includes but is not limited to a controllable switch S1, a controllable switch S2 and a diode D1; the power supply end of the controllable switch S1 is connected to the first drive voltage output end of the injection power supply circuit; the power supply end of the controllable switch S2 is connected to the second drive voltage output end of the injection power supply circuit; the positive electrode of the diode D1 is connected to one end of the controllable switch S2, and the negative electrode of the diode D1 is connected to one end of the controllable switch S1 and one end of the injection coil in the plurality of nozzles.

[0010] As an optional embodiment, each of the N low-side injection drive circuits includes a controllable switch, one end of which is connected to one end of the injection coil in the nozzle, and the other end is connected to one end of the sampling resistor, and the other end of the sampling resistor is grounded.

[0011] As an optional embodiment, the natural gas engine injection control circuit also includes a drive voltage detection circuit, an injection current detection circuit and a drive fault detection circuit; the output end of the drive voltage detection circuit is connected to the drive voltage detection signal input end of the injection controller; the output end of the injection current detection circuit is connected to the injection current detection signal input end of the injection controller; and the drive fault detection circuit is connected to the drive fault detection signal input end.

[0012] As an optional implementation, the injection controller adopts but is not limited to an injection control chip or a micro control unit (MCU).

[0013] As an optional implementation, the controllable switch S1 is but not limited to a MOS transistor; the controllable switch S2 is but not limited to a MOS transistor.

[0014] In a second aspect, an embodiment of the present invention provides a natural gas engine injection control system, which adopts the natural gas engine injection control circuit described in any one of the first aspects above.

[0015] Compared with traditional natural gas engine injection control schemes, the technical solution proposed in the embodiments of the present invention has the following advantages: 1. N low-side injection drive circuits in the injection drive circuit share one high-side injection drive circuit. The N low-side injection drive circuits correspond to nozzles respectively. Different nozzles use different low-side injection drive circuits. The corresponding low-side injection drive circuit can be selected according to the injection requirements of different nozzles, which makes control flexible and convenient. In addition, the high-side injection drive circuit uses only one diode, which greatly simplifies the structure of the injection drive circuit, reduces the failure rate of the injection drive circuit, and reduces the cost of the natural gas engine injection control circuit. 2. The input end of the first boost circuit in the injection power supply circuit is connected to the input end of the second boost circuit and the output end of the injection power supply. The output end of the first boost circuit is connected to the first power supply end of the high-side injection drive circuit, and the output end of the second boost circuit is connected to the second power supply end of the high-side injection drive circuit. The injection power supply circuit ensures a stable power supply voltage for the injection drive circuit through the first boost circuit and the second boost circuit, effectively preventing the operation of the injection drive circuit from being affected by excessively low voltage of the injection power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate and understand the technical solutions in the embodiments of the present invention, a brief introduction is given below to the background technology of the present invention and the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0017] Figure 1 This is a schematic diagram of the structure of the natural gas engine injection control circuit provided in Example 1 of the present utility model;

[0018] Figure 2 This is a structural diagram of the injection power supply circuit provided in Example 2 of the present utility model;

[0019] Figure 3 This is a structural diagram of the jet drive circuit provided in Example 2 of the present utility model;

[0020] Figure 4 This is a working logic diagram of the ejection drive circuit provided in the second embodiment of the present utility model. DETAILED DESCRIPTION

[0021] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0022] Example 1

[0023] Please refer to Figure 1 As stated, Figure 1 This is a schematic diagram of the structure of the natural gas engine injection control circuit provided in the first embodiment of the present invention. As shown in the figure, the natural gas engine injection control circuit 100 in this embodiment includes an injection controller 101, an injection drive circuit and an injection power supply circuit 102.

[0024] In this embodiment, the ejection driving circuit includes one high-side ejection driving circuit 103 and N low-side ejection driving circuits 104 , where N is a positive integer.

[0025] In this embodiment, the control end of the high-side jet drive circuit 103 is connected to an output end of the jet controller 101, the driving end of the high-side jet drive circuit 103 is connected to one end of the jet coil 105 in a plurality of nozzles, and the N-way low-side jet drive circuit 104 is connected to the other end of the jet coil 105 in the plurality of nozzles; the output end of the jet power supply circuit 102 is connected to the power supply end of the high-side jet drive circuit 103.

[0026] Exemplarily, the natural gas engine injection control circuit 100 further includes a driving voltage detection circuit 106, an injection current detection circuit 107, and a driving fault detection circuit 108; the output end of the driving voltage detection circuit 106 is connected to the driving voltage detection signal input end of the injection controller 101; the output end of the injection current detection circuit 107 is connected to the injection current detection signal input end of the injection controller 101; and the driving fault detection circuit 108 is connected to the driving fault detection signal input end.

[0027] For example, the injection controller 101 is, but not limited to, an injection control chip or a microcontroller unit (MCU), etc. In this embodiment, the injection control chip is preferably a driver chip.

[0028] Specifically, the injection controller 101 controls the injection drive circuit to select the nozzle requiring injection. The injection power supply circuit 102 provides a stable power supply voltage to the high-side injection drive circuit 103. The high-side injection drive circuit 103 and the low-side injection drive circuit 104 output drive currents based on the injection requirements of different nozzles, energizing the injection coil 105 in the nozzle to complete natural gas injection control.

[0029] In the natural gas engine injection control circuit 100 proposed in this embodiment, the N low-side injection drive circuits 104 in the injection drive circuit share a high-side injection drive circuit 103. The N low-side injection drive circuits 104 correspond to nozzles respectively. Different nozzles use different low-side injection drive circuits 104. The corresponding low-side injection drive circuit 104 can be selected according to the injection requirements of different nozzles. This provides flexible and convenient control, simplifies the injection drive circuit structure, and reduces the cost of the natural gas engine injection control circuit 100.

[0030] Example 2

[0031] In this embodiment, the natural gas engine injection control circuit 100 includes an injection controller 101, an injection drive circuit 204, and an injection power supply circuit 102. The injection drive circuit 204 includes one high-side injection drive circuit 103 and N low-side injection drive circuits 104, where N is a positive integer. The control terminal of the high-side injection drive circuit 103 is connected to an output terminal of the injection controller 101, the drive terminal of the high-side injection drive circuit 103 is connected to one end of the injection coils 105 in the nozzles, and the N low-side injection drive circuits 104 are connected to the other ends of the injection coils 105 in the nozzles. The output terminal of the injection power supply circuit 102 is connected to the power supply terminal of the high-side injection drive circuit 103.

[0032] For example, Figure 2 As shown, the jet power supply circuit 102 includes a jet power supply 201, a first boost circuit 202 and a second boost circuit 203; the input end of the first boost circuit 202 is connected to the input end of the second boost circuit 203 and the output end of the jet power supply 201, the output end of the first boost circuit 202 is connected to the first power supply end of the high-side jet drive circuit 103, and the output end of the second boost circuit 203 is connected to the second power supply end of the high-side jet drive circuit 103.

[0033] In this embodiment, the jet power supply 201 is preferably a low-voltage battery. Regardless of the low-voltage battery voltage, the first boost circuit 202 supplies power to the high-side jet drive circuit 103 for stably outputting the first drive voltage U1, such as but not limited to 48V. The second boost circuit 203 supplies power to the high-side jet drive circuit 103 for stably outputting the second drive voltage U2, such as but not limited to 28V. The jet power supply circuit 102 proposed in this embodiment makes it possible for the drive voltage of the high-side jet drive circuit 103 in the current holding stage no longer to be affected by the low-voltage battery voltage and the stray inductance of the power supply circuit. When the low-voltage battery voltage is fed, sufficient energy can still be provided, and the high-side jet drive circuit 103 is no longer affected by the low voltage of the low-voltage battery.

[0034] For example, Figure 3 As shown, the high-side injection drive circuit 103 includes but is not limited to a controllable switch S1, a controllable switch S2, and a diode D1. The power supply terminal of the controllable switch S1 is connected to the first drive voltage output terminal of the injection power supply circuit 102; the power supply terminal of the controllable switch S2 is connected to the second drive voltage output terminal of the injection power supply circuit 102; the anode of the diode D1 is connected to one end of the controllable switch S2, and the cathode of the diode D1 is connected to one end of the controllable switch S1 and one end of the injection coils 105 in the plurality of nozzles.

[0035] In this embodiment, the controllable switch S1 is preferably a MOS transistor, but is not limited thereto, and may also be a transistor that meets its function. The controllable switch S2 is preferably a MOS transistor, but is not limited thereto, and may also be a transistor that meets its function.

[0036] For example, Figure 3 As shown, each of the N low-side jet driver circuits 104 includes a controllable switch. One end of the controllable switch is connected to one end of the jet coil 105 in the nozzle, and the other end is connected to one end of a sampling resistor R1. The other end of the sampling resistor R1 is grounded. In this embodiment, the two ends of the sampling resistor R1 are connected in parallel to a current sampling circuit CY1.

[0037] In this embodiment, the N low-side injection driver circuits 104 correspond one to each of the injection coils 105 in the nozzles. Different nozzles use different low-side injection driver circuits 104. The first injection coil 105L1 through the nth injection coil 105Ln correspond to controllable switches K1 through Kn, respectively. The injection controller 101 can select the corresponding low-side injection driver circuit 104 to operate according to the injection requirements of different nozzles by controlling the controllable switches. In specific applications, the controllable switches K1 through Kn are preferably MOS transistors, but are not limited to this. They can also be transistors that meet their functions.

[0038] Exemplarily, the natural gas engine injection control circuit 100 further includes a driving voltage detection circuit 106, an injection current detection circuit 107, and a driving fault detection circuit 108; the output end of the driving voltage detection circuit 106 is connected to the driving voltage detection signal input end of the injection controller 101; the output end of the injection current detection circuit 107 is connected to the injection current detection signal input end of the injection controller 101; and the driving fault detection circuit 108 is connected to the driving fault detection signal input end.

[0039] In this embodiment, the injection controller 101 is, but not limited to, an injection control chip or a micro control unit, etc. In this embodiment, the injection control chip is preferably a driver chip, but not limited thereto.

[0040] In this embodiment, if Figure 4 As shown, the injection controller 101 controls the operation of the high-side injection driver circuit 103 by turning on and off controllable switches S1 and S2. The injection controller 101 selects the nozzle to be operated based on the injection requirements of each nozzle. During operation, the injection controller 101 outputs control signals to the controllable switches K1, K2, ..., Kn, turning on and off the controllable switches K1, K2, ..., Kn to select the corresponding low-side injection driver circuit 104 for operation. Simultaneously, the injection power supply circuit 102 outputs a first drive voltage U1 (e.g., 48V), thereby turning on the controllable switch S1 and drawing a transient current into the injection coil 105 in the nozzle, causing the nozzle to spray natural gas. During the current maintenance period in the injection coil 105, the injection controller 101 controls the power supply circuit to output a second drive voltage U2 (e.g., 28V), turning on the controllable switch S2 to maintain the nozzle's injection operation.

[0041] The advantages of the natural gas engine injection control circuit 100 proposed in the embodiment of the present utility model are as follows: 1. The N low-side injection drive circuits 104 in the injection drive circuit 204 share a high-side injection drive circuit 103. The N low-side injection drive circuits 104 correspond to the nozzles respectively. Different nozzles use different low-side injection drive circuits 104. The corresponding low-side injection drive circuit 104 can be selected according to the injection requirements of different nozzles. The control is flexible and convenient. In addition, the high-side injection drive circuit 103 only uses one diode D1, which greatly simplifies the structure of the injection drive circuit 204, reduces the failure rate of the injection drive circuit, and reduces the natural gas engine. The cost of the injection control circuit 100; 2. The input of the first boost circuit 202 in the injection power supply circuit 102 is connected to the input of the second boost circuit 203 and the output of the injection power supply 201. The output of the first boost circuit 202 is connected to the first power supply of the high-side injection driver circuit 103, and the output of the second boost circuit 203 is connected to the second power supply of the high-side injection driver circuit 103. The injection power supply circuit 102 ensures a stable supply voltage for the injection driver circuit 204 through the first boost circuit 202 and the second boost circuit 203, effectively preventing the operation of the injection driver circuit 204 from being affected by low voltage of the injection power supply 201. The natural gas engine injection control circuit 100 proposed in this embodiment of the utility model has a simple structure, flexible and convenient control, low cost, and is suitable for widespread application.

[0042] Example 3

[0043] This embodiment provides a natural gas engine injection control system, which utilizes the natural gas engine injection control circuit 100 proposed in either the first or second embodiment. The natural gas engine injection control circuit 100 includes an injection controller 101, an injection drive circuit, and an injection power supply circuit 102. The injection drive circuit includes one high-side injection drive circuit 103 and N low-side injection drive circuits 104, where N is a positive integer. The control terminal of the high-side injection drive circuit 103 is connected to an output terminal of the injection controller 101, the drive terminal of the high-side injection drive circuit 103 is connected to one terminal of the injection coils 105 in the nozzles, and the N low-side injection drive circuits 104 are connected to the other terminals of the injection coils 105 in the nozzles. The output terminal of the injection power supply circuit 102 is connected to the power supply terminal of the high-side injection drive circuit 103.

[0044] It is worth noting that, in this embodiment, the natural gas engine injection control circuit 100 is the same as the natural gas engine injection control circuit 100 proposed in any one of the above-mentioned embodiments 1 or 2, and will not be described in detail here. The advantages of the natural gas engine injection control system proposed in the embodiment of the present invention are as follows: 1. The N low-side injection drive circuits 104 in the injection drive circuit share one high-side injection drive circuit 103, and the N low-side injection drive circuits 104 correspond to the nozzles respectively. Different nozzles use different low-side injection drive circuits 104. The corresponding low-side injection drive circuit 104 can be selected to work according to the injection requirements of different nozzles. The control is flexible and convenient, and the high-side injection drive circuit 103 only uses one diode D1, which greatly simplifies the structure of the injection drive circuit, reduces the failure rate of the injection drive circuit, and reduces the natural gas engine injection. The cost of the injection control circuit 100 is reduced. 2. The input end of the first boost circuit 202 in the injection power supply circuit 102 is connected to the input end of the second boost circuit 203 and the output end of the injection power supply 201. The output end of the first boost circuit 202 is connected to the first power supply end of the high-side injection driver circuit 103, and the output end of the second boost circuit 203 is connected to the second power supply end of the high-side injection driver circuit 103. The injection power supply circuit 102 ensures a stable supply voltage for the injection driver circuit through the first boost circuit 202 and the second boost circuit 203, effectively preventing the operation of the injection driver circuit from being affected by the low voltage of the injection power supply 201. The natural gas engine injection control system proposed in this embodiment of the utility model has a simple structure, flexible and convenient control, low cost, and is suitable for widespread application.

[0045] Note that the above are merely preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions are possible for those skilled in the art without departing from the scope of protection of the present invention. Therefore, while the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A natural gas engine injection control circuit, characterized in that: It includes an injection controller, an injection driving circuit and an injection power supply circuit; The injection driving circuit includes one high-side injection driving circuit and N low-side injection driving circuits, wherein N is a positive integer; The control end of the high-side injection drive circuit is connected to an output end of the injection controller, the driving end of the high-side injection drive circuit is connected to one end of the injection coil in a plurality of nozzles, and the N-way low-side injection drive circuit is connected to the other end of the injection coil in the plurality of nozzles; the output end of the injection power supply circuit is connected to the power supply end of the high-side injection drive circuit.

2. The natural gas engine injection control circuit according to claim 1, characterized in that: The injection power supply circuit includes a first boost circuit, a second boost circuit and an injection power supply; the input end of the first boost circuit is connected to the input end of the second boost circuit and the output end of the injection power supply, the output end of the first boost circuit is connected to the first power supply end of the high-side injection drive circuit, and the output end of the second boost circuit is connected to the second power supply end of the high-side injection drive circuit.

3. The natural gas engine injection control circuit according to claim 1, characterized in that: The high-side injection driving circuit includes but is not limited to a controllable switch S1, a controllable switch S2 and a diode D1; the power supply end of the controllable switch S1 is connected to the first driving voltage output end of the injection power supply circuit; the power supply end of the controllable switch S2 is connected to the second driving voltage output end of the injection power supply circuit; the anode of the diode D1 is connected to one end of the controllable switch S2, and the cathode of the diode D1 is connected to one end of the controllable switch S1 and one end of the injection coils in the plurality of nozzles.

4. The natural gas engine injection control circuit according to claim 1, characterized in that: Each of the N low-side injection drive circuits includes a controllable switch, one end of which is connected to one end of the injection coil in the nozzle, and the other end is connected to one end of the sampling resistor, and the other end of the sampling resistor is grounded.

5. The natural gas engine injection control circuit according to claim 1, characterized in that: It also includes a driving voltage detection circuit, an injection current detection circuit and a driving fault detection circuit; the output end of the driving voltage detection circuit is connected to the driving voltage detection signal input end of the injection controller; The output end of the injection current detection circuit is connected to the injection current detection signal input end of the injection controller; The driving fault detection circuit is connected to the driving fault detection signal input terminal.

6. The natural gas engine injection control circuit according to claim 3, characterized in that: The controllable switch S1 may be, but not limited to, a MOS tube; the controllable switch S2 may be, but not limited to, a MOS tube.

7. The natural gas engine injection control circuit according to any one of claims 1 to 6, characterized in that: The injection controller adopts but is not limited to an injection control chip or a micro control unit.

8. A natural gas engine injection control system, characterized in that: The system adopts the natural gas engine injection control circuit described in claim 1.

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