A method and structure for measuring fuel quantity in a fuel injector

Abstract

This invention provides a method and structure for measuring fuel injector quantity, relating to the field of internal combustion engine fuel injection technology. The fuel injector quantity measurement method includes acquiring the measured temperature and flow rate of the fuel injected by the fuel injector; obtaining the average volumetric flow rate at a corrected temperature based on the measured temperature and flow rate; obtaining the flow coefficient corresponding to the average volumetric flow rate; and calculating the accurate flow rate injected by the fuel injector based on the average volumetric flow rate and the flow coefficient. This fuel injector quantity measurement method fully considers the influence of temperature on flow rate measurement, and further corrects the flow rate using the flow coefficient after temperature compensation correction, thereby effectively improving the accuracy and reliability of the measured flow rate data.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine fuel injection technology, and more specifically, to a method and structure for measuring fuel quantity in a fuel injector. Background Technology

[0002] Fuel injectors are crucial components in internal combustion engines, injecting fuel into the combustion chamber for power conversion. For example, in current diesel-methanol dual-fuel engines, the high-pressure methanol injection system is the engine's power source, and the methanol injector is one of the core components of the high-pressure common rail system. Its performance directly affects the overall performance of the entire high-pressure common rail system. Therefore, fuel injectors need to be tested to evaluate their performance, with flow rate testing being one of the most important tests.

[0003] Currently, single-injection testing is commonly used in clean fuel injection testing facilities, primarily employing a single-injection measuring instrument. This testing method is cumbersome and time-consuming. Furthermore, the flow data obtained by existing measurement methods has poor accuracy and low reliability, which adversely affects subsequent fuel system product development and performance verification. Summary of the Invention

[0004] The purpose of this invention is to provide a method for measuring fuel quantity in a fuel injector, which can improve the technical problems of poor accuracy and low reliability in the measurement of fuel injection quantity in the prior art.

[0005] The present invention also aims to provide a fuel injector fuel quantity measurement structure that can improve the technical problems of poor fuel injection quantity accuracy and low reliability in the prior art.

[0006] The embodiments of the present invention can be implemented in the following ways:

[0007] A method for measuring fuel injector fuel quantity, the method comprising:

[0008] To obtain the measured temperature and flow rate of the fuel injected by the fuel injector;

[0009] The average volumetric flow rate at the corrected temperature is obtained based on the measured temperature and the measured flow rate.

[0010] Obtain the flow coefficient corresponding to the average volumetric flow rate;

[0011] The accurate flow rate of the fuel injector is calculated based on the average volumetric flow rate and the flow coefficient.

[0012] Optionally, the step of obtaining the average volumetric flow rate at the corrected temperature based on the measured temperature and the measured flow rate includes:

[0013] The measured flow rate is converted into the volumetric flow rate at the corrected temperature using the following formula:

[0014]

[0015] Among them, Q T1 Q is the volumetric flow rate at the corrected temperature; T2 The measured flow rate; ρ T2 ρ is the density of the oil at the measured temperature. T1 The oil density at the corrected temperature;

[0016] The average volumetric flow rate at the corrected temperature is calculated based on the volumetric flow rate, using the following formula:

[0017]

[0018] Where, ΔQ T1 The average volumetric flow rate is denoted as t, which is the duration of one metering cycle.

[0019] Optionally, before the step of obtaining the flow coefficient corresponding to the average volumetric flow rate, the fuel injector oil quantity measurement method further includes:

[0020] Divide the flow rate into intervals and calculate the flow coefficient for each interval.

[0021] The step of obtaining the flow coefficient corresponding to the average volumetric flow rate includes:

[0022] Determine the flow range to which the average volumetric flow rate belongs, and use the flow coefficient corresponding to the flow range as the flow coefficient corresponding to the average volumetric flow rate.

[0023] Optionally, the step of dividing the flow rate into intervals and determining the flow rate coefficient for each interval includes:

[0024] The flow rate was divided into the following intervals: (0 ml / min, 100 ml / min), [100 ml / min, 500 ml / min), [500 ml / min, 1000 ml / min), [1000 ml / min, 2000 ml / min), [2000 ml / min, 3000 ml / min), and [3000 ml / min, 4000 ml / min).

[0025] For each flow range, multiple sets of data on the volumetric flow rate and the average volumetric flow rate at the correction temperature within a metering cycle are obtained using the gravimetric method. The volumetric flow rate Q obtained by the gravimetric method is... T1称重 and the average volumetric flow rate ΔQ at the corrected temperature T1 Satisfy the following formula:

[0026] Q T1称重 =aΔQ T1 +b;

[0027] Where a and b are flow coefficients.

[0028] Optionally, the formula for calculating the accurate flow rate of the fuel injector based on the average volumetric flow rate and the flow coefficient is as follows:

[0029] Q′=aΔQ T1 +b

[0030] Where Q′ is the accurate flow rate; ΔQ T1 The average volumetric flow rate is given; a and b are flow coefficients.

[0031] Optionally, the corrected temperature is 40°C.

[0032] A fuel injector fuel quantity measurement structure, the fuel injector fuel quantity measurement structure comprising:

[0033] The medium metering module is used to acquire the measured temperature and flow rate of the fuel injected by the fuel injector, and to obtain the average volumetric flow rate at a corrected temperature based on the measured temperature and the measured flow rate; the medium metering module is also used to acquire the flow coefficient corresponding to the average volumetric flow rate, and to calculate the accurate flow rate of the fuel injected by the fuel injector based on the average volumetric flow rate and the flow coefficient.

[0034] Optionally, the medium metering module includes a temperature sensor, a flow meter, and a controller, wherein the temperature sensor and the flow meter are both electrically connected to the controller; the temperature sensor is used to acquire the temperature of the fuel injected by the fuel injector and transmit the temperature signal characterizing the temperature to the controller; the flow meter is used to acquire the flow rate of the fuel injected by the fuel injector and transmit the measured flow rate characterizing the flow rate to the controller; the controller is used to obtain the average volumetric flow rate at a corrected temperature based on the measured temperature and the measured flow rate, and to calculate the accurate flow rate injected by the fuel injector based on the flow coefficient corresponding to the average volumetric flow rate and the average volumetric flow rate.

[0035] Optionally, the temperature sensor is located upstream of the flow meter.

[0036] Optionally, the fuel injector oil quantity measurement structure further includes a pressure stabilizing and filtering module, which has an oil inlet and an oil outlet. The oil inlet is used to receive the oil injected by the fuel injector, and the oil outlet is connected to the medium metering module.

[0037] The pressure stabilizing and filtering module includes a demisting block, a straight pipe, a pressure stabilizing tank, and a throttling device connected in sequence; the oil inlet is the inlet of the demisting block, and the oil outlet is the outlet of the throttling device; the demisting block is used to collect the oil jet ejected by the fuel injector; the straight pipe is used to reduce pressure fluctuations in the oil flow; the pressure stabilizing tank is used to store the oil and stabilize the pressure; the throttling device has a throttling orifice connecting the pressure stabilizing tank and the oil outlet, and the throttling orifice is used to suppress pulsating impacts generated by continuous injection.

[0038] Optionally, the defogging block includes a connecting channel and a first chamber and a second chamber disposed on both sides of the connecting channel, and the connecting channel connects the first chamber and the second chamber; the oil inlet is formed on the side of the first chamber away from the second chamber, and the side of the second chamber away from the first chamber is connected to the straight pipe;

[0039] The cross-sectional area of ​​the first chamber is greater than that of the second chamber, the cross-sectional area of ​​the second chamber is greater than that of the connecting channel, and the end of the first chamber that connects to the connecting channel has a first conical surface, and the end of the second chamber that connects to the connecting channel has a second conical surface.

[0040] Optionally, the diameter of the throttling orifice is 0.8 mm to 1.2 mm.

[0041] The beneficial effects of the fuel injector fuel quantity measurement method and structure provided by the embodiments of the present invention include:

[0042] This invention provides a method for measuring fuel injector quantity, comprising: acquiring the measured temperature and flow rate of the fuel injected by the fuel injector; obtaining the average volumetric flow rate at a corrected temperature based on the measured temperature and flow rate; acquiring the flow coefficient corresponding to the average volumetric flow rate; and calculating the accurate flow rate injected by the fuel injector based on the average volumetric flow rate and the flow coefficient. This fuel injector quantity measurement method fully considers the influence of temperature on flow rate measurement, and further corrects the flow rate using the flow coefficient after temperature compensation correction, thereby effectively improving the accuracy and reliability of the measured flow rate data.

[0043] Embodiments of the present invention also provide a fuel injector fuel quantity measurement structure, which includes a medium metering module. The medium metering module is used to acquire the measured temperature and flow rate of the fuel injected by the fuel injector, and to obtain the average volumetric flow rate at a corrected temperature based on the measured temperature and the measured flow rate. Furthermore, the medium metering module is used to acquire the flow coefficient corresponding to the average volumetric flow rate, and to calculate the accurate flow rate injected by the fuel injector based on the average volumetric flow rate and the flow coefficient. This fuel injector fuel quantity measurement structure fully considers the influence of temperature on flow rate measurement, and further corrects the flow rate using the flow coefficient after temperature compensation correction, thereby effectively improving the accuracy and reliability of the measured flow rate data. Attached Figure Description

[0044] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0045] Figure 1 A schematic diagram of a fuel injector fuel quantity measurement structure according to one aspect of the present invention is shown.

[0046] Figure 2 A cross-sectional schematic diagram of a voltage stabilizing filter module in a fuel injector fuel quantity measurement structure provided according to one aspect of the present invention is shown.

[0047] Figure 3 A schematic diagram of the internal structure of the demisting block in a fuel injector fuel quantity measurement structure provided according to one aspect of the present invention is shown.

[0048] Figure 4 It shows Figure 2 Enlarged schematic diagram of the local structure at point I;

[0049] Figure 5 A graph showing the verification test results provided according to one aspect of the present invention is shown;

[0050] Figure 6 A step diagram of a fuel injector fuel quantity measurement method according to one aspect of the present invention is shown.

[0051] Figure label:

[0052] 10-Fuel injector oil quantity measurement structure; 100-Injector tooling; 110-Fuel injector; 200-Pressure stabilizing filter module; 210-Anti-misting block; 211-Oil inlet; 212-First chamber; 213-First conical surface; 214-Connecting channel; 215-Second chamber; 216-Second conical surface; 220-Straight pipe; 230-Pressure stabilizing tank; 231-First opening; 232-Second opening; 233-Adapter; 240-Throttling element; 241-Throttling orifice; 242-Oil outlet; 300-Cooling filter module; 311-Plate heat exchanger; 312-Filter; 400-Media metering module; 411-Temperature sensor; 412-Flow meter; 413-Controller; 500-Oil return module; 511-Coil; 512-Oil tank. Detailed Implementation

[0053] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0054] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," "outer," or "vertical" appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use, and does not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0055] At the same time, it should be noted that the terms "first" and "second" are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance.

[0056] In the description of this invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0057] Figure 1 This is a schematic diagram of the fuel injector fuel quantity measurement structure 10 provided in this embodiment. Please refer to... Figure 1This embodiment provides a fuel injector fuel quantity measurement structure 10, which includes a medium metering module 400. The medium metering module 400 is used to acquire the measured temperature and flow rate of the fuel injected by the fuel injector 111, and to obtain the average volumetric flow rate at a corrected temperature based on the measured temperature and the measured flow rate. The medium metering module 400 is also used to acquire the flow coefficient corresponding to the average volumetric flow rate, and to calculate the accurate flow rate injected by the fuel injector based on the average volumetric flow rate and the flow coefficient. This fuel injector fuel quantity measurement structure fully considers the influence of temperature on flow rate measurement, and further corrects the flow rate using the flow coefficient after temperature compensation correction, thereby effectively improving the accuracy and reliability of the measured flow rate data.

[0058] The fuel injector fuel quantity measurement structure 10 provided in this embodiment will be further described below:

[0059] Please continue to refer to Figure 1 In this embodiment, the medium metering module 400 includes a temperature sensor 411, a flow meter 412, and a controller 413. Both the temperature sensor 411 and the flow meter 412 are electrically connected to the controller 413. The temperature sensor 411 is used to obtain the temperature of the fuel injected by the fuel injector; the temperature obtained by the temperature sensor 411 is the measured temperature. Simultaneously, the temperature sensor 411 also transmits the temperature signal characterizing the measured temperature to the controller 413. The flow meter 412 is used to obtain the flow rate of the fuel injected by the fuel injector 111; the flow rate obtained by the flow meter 412 is the measured flow rate. Simultaneously, the flow meter 412 also transmits the flow rate signal characterizing the measured flow rate to the controller 413. The controller 413 is used to obtain the average volumetric flow rate at a corrected temperature based on the measured temperature and the measured flow rate, and to calculate the accurate flow rate injected by the fuel injector based on the flow coefficient corresponding to the average volumetric flow rate and the average volumetric flow meter 412. Specifically, the operation process of the controller 413 will be described later.

[0060] Furthermore, the temperature sensor 411 is positioned upstream of the flow meter 412. In other words, the liquid oil injected by the fuel injector 111 first passes through the temperature sensor 411 and then flows through the flow meter 412. Optionally, the temperature sensor 411 is a high-precision platinum resistance temperature sensor. Optionally, the flow meter 412 is a gear flow meter. The gear flow meter is a high-precision type with a flow measurement range of 0.01 to 10 L / min, a measurement accuracy of ±0.3% of the actual measured value, and a repeatability of ±0.05%, capable of real-time monitoring of the oil flow rate passing through the gear flow meter. It is understood that in some other embodiments, other types of temperature sensors 411 and flow meters 412 may also be used.

[0061] In this embodiment, the fuel injector oil quantity measurement structure 10 also includes a pressure stabilizing and filtering module 200. The pressure stabilizing and filtering module 200 can effectively reduce the impact of pressure fluctuations in the high-pressure medium on the flow rate, thereby improving the flow rate measurement accuracy. The pressure stabilizing and filtering module 200 has an oil inlet 211 and an oil outlet 242. The oil inlet 211 is used to receive the oil injected by the fuel injector 111, and the oil outlet 242 is connected to the medium metering module 400. Thus, the oil injected by the fuel injector 111 enters the medium metering module 400 after being processed by the pressure stabilizing and filtering module 200, ultimately resulting in more accurate flow rate data.

[0062] Figure 2 This diagram shows a cross-sectional view of the voltage stabilizing and filtering module 200 in the fuel injector fuel quantity measurement structure 10 provided in this embodiment. Please refer to the attached diagram. Figure 1 and Figure 2 Specifically, the voltage stabilizing filter module 200 includes a demisting block 210, a straight pipe 220, a voltage stabilizing pipe, and a throttling device 240 connected in sequence. The demisting block 210 has a passage for oil flow, through which it receives oil injected by the fuel injector 111. Correspondingly, the demisting block 210 has an inlet for oil to enter the demisting block 210, which serves as the oil inlet 211 of the voltage stabilizing filter module 200. Similarly, the throttling device 240 has a passage for oil flow, through which it draws oil downstream. Correspondingly, the throttling device 240 has an outlet for oil to flow out, which serves as the oil outlet 242 of the voltage stabilizing filter module 200. The demisting block 210 is used to collect the oil jet sprayed out by the fuel injector 111; the branch pipe is used to reduce pressure fluctuations in the oil flow; the pressure stabilizing tank 230 is used to store oil and stabilize pressure; the throttling element 240 has a throttling orifice 241 connecting the pressure stabilizing tank 230 and the oil outlet 242, and the throttling orifice 241 suppresses the pulsating impact generated by continuous injection.

[0063] Furthermore, the fuel injector quantity measurement structure 10 also includes an injector fixture, which is mounted on the demisting block 210 and connected to the fuel inlet 211. When measuring the fuel quantity of the fuel injector 111, the fuel injector 111 to be measured is mounted on the injector fixture, thereby connecting the fuel injector 111 to the demisting block 210. At the same time, setting up the injector fixture helps to ensure the fuel sealing, making the measurement signal accurate and effective.

[0064] Optionally, the injector fixture and the demisting block 210 are effectively fastened together by bolts, and a copper gasket is also provided at the connection between the injector and the demisting block 210 to ensure effective sealing at the connection.

[0065] Figure 3This diagram illustrates the internal structure of the demisting block 210 in the fuel injector fuel quantity measurement structure 10 provided in this embodiment. Please refer to the attached diagram. Figures 1-3 The working principle of the defogging block 210 is that it is a pressure vessel with a certain shape and volume determined according to different injection pressures and injection flow rates. In this embodiment, the defogging block 210 includes a connecting channel 214 and a first chamber 212 and a second chamber 215 disposed on both sides of the connecting channel 214, and the connecting channel 214 connects the first chamber 212 and the second chamber 215. An oil inlet 211 is formed on the side of the first chamber 212 away from the second chamber 215, and the side of the second chamber 215 away from the first chamber 212 is connected to a straight pipe 220. The cross-sectional area of ​​the first chamber 212 is larger than the cross-sectional area of ​​the second chamber 215, and the cross-sectional area of ​​the second chamber 215 is larger than the cross-sectional area of ​​the connecting channel 214. The end of the first chamber 212 connected to the connecting channel 214 has a first conical surface 213, and the end of the second chamber 215 connected to the connecting channel 214 has a second conical surface 216.

[0066] Specifically, the space with a certain shape and volume in the demisting block 210 includes a first chamber 212, a connecting channel 214, and a second chamber 215. The first chamber 212 is located on the side of the demisting block 210 that connects to the fuel injector fixture. The liquid oil injected by the fuel injector 111 first enters the first chamber 212, then enters the second chamber 215 through the connecting channel 214, and exits the demisting block 210 from the second chamber 215 before entering the straight pipe 220. The first chamber 212, the second chamber 215, and the connecting channel 214 are all roughly cylindrical chambers, and the cross-sectional area of ​​the first chamber 212 is larger than that of the second chamber 215, while the cross-sectional area of ​​the second chamber 215 is larger than that of the connecting channel 214. In other words, the internal space of the demisting block 210 is roughly a structure that is large at both ends and small in the middle.

[0067] Meanwhile, the end of the first chamber 212 connected to the connecting channel 214 has a first conical surface 213. The cross-sectional area of ​​the first conical surface 213 decreases along the direction approaching the connecting channel 214, and the cross-sectional area at the connection between the first conical surface 213 and the connecting channel 214 is the same as the cross-sectional area of ​​the connecting channel 214. The end of the second chamber 215 connected to the connecting channel 214 has a second conical surface 216. The cross-sectional area of ​​the second conical surface 216 decreases along the direction approaching the connecting channel 214, and the cross-sectional area at the connection between the second conical surface 216 and the connecting channel 214 is the same as the cross-sectional area of ​​the connecting channel 214. Experiments have verified that the space of this shape and structure can effectively handle the collection of the fuel jet injected by the fuel injector 111.

[0068] Furthermore, the inner wall of the defogging block 210 is treated with a strengthening process.

[0069] In this embodiment, the straight pipe 220 is connected to the demisting block 210 by bolts. The straight pipe 220 can effectively solve the pressure fluctuation of the oil in the pipeline. The straight pipe 220 is a tubular component of a certain length, which connects the demisting block 210 and the pressure stabilizing tank 230. In order to ensure the effect of the straight pipe 220 in improving the pressure fluctuation, the length L, inner diameter d, and wall thickness δ of the straight pipe 220 can be set. Specifically, since the length L, inner diameter d, and wall thickness δ of the straight pipe 220 and the pressure fluctuation ΔP satisfy the following formula:

[0070] ΔP=ρv(L / t)=ρvc

[0071]

[0072] Where L is the length of the pressure channel, t is the time it takes for the pressure wave to travel from the pressure source to the valve port, ΔP is the pressure fluctuation, ρ is the liquid density, v is the flow velocity of the liquid medium in the channel, c is the propagation velocity of the compressible liquid pressure wave, K is the elastic modulus of the liquid, E is the elastic modulus of the pipeline channel, δ is the wall thickness of the pipeline channel, and d is the diameter of the pipeline channel.

[0073] Therefore, the length L, inner diameter d, and wall thickness δ of the straight pipe 220 can be set in the following manner to reduce pressure fluctuation ΔP.

[0074] 1. Increase pipeline length:

[0075] For a certain medium, within a certain range of temperature and pressure variations, the longer the pipeline, the longer the time required for a single pressure wave to propagate, that is, the longer the propagation period of the pressure wave.

[0076] 2. Regarding methods to reduce the propagation speed of pressure waves: K, the elastic modulus of liquid is related to the medium. Within the allowable strength range, reduce the inner wall of the pipe and increase the pipe diameter.

[0077] The pressure stabilizing tank 230 is a pressure vessel with a certain volume, serving as an oil storage container downstream of the straight pipe 220 to further stabilize the oil pressure and eliminate the effects of fluctuations. The pressure stabilizing tank 230 is bolted to the straight pipe 220, and a copper gasket is installed at the connection to form an effective seal.

[0078] Figure 4 for Figure 2 A magnified view of the local structure at point I. Please refer to the reference. Figures 1-4In this embodiment, the throttling device 240 is installed on the pressure stabilizing tank 230, and the throttling device 240 has a throttling orifice 241 communicating with the pressure stabilizing tank 230, through which the pressure stabilizing tank 230 and the medium metering module 400 are connected. Specifically, a first opening 231 and a second opening 232 are provided on the upper end face of the pressure stabilizing tank 230, and a straight pipe 220 is fixedly connected to the first opening 231, so that the oil in the straight pipe 220 enters the pressure stabilizing tank 230 through the first opening 231. The throttling device 240 is installed at the second opening 232, and the oil in the pressure stabilizing tank 230 enters the throttling device 240 through the second opening 232 and flows out through the throttling orifice 241. Optionally, an adapter 233 is provided at the second opening 232, and the throttling device 240 is installed at the adapter 233.

[0079] Optionally, the orifice diameter of the throttling orifice 241 is 0.8 mm to 1.2 mm. Optionally, the orifice diameter of the throttling orifice 241 can be set to 0.8 mm, 1.0 mm, or 1.2 mm. Further, to verify the effect of the throttling orifice 241, an orifice 241 with a diameter of 1.0 mm is used as an example, and an orifice 241 with a diameter of 1.5 mm is used as a comparative example for experimental verification. Figure 5 The test results are shown, such as Figure 5 As shown, curve 1 is the pressure pulsation curve inside the pressure stabilizing tank 230 under a rail pressure of 1550 bar in the embodiment, and curve 2 is the pressure pulsation curve inside the pressure stabilizing tank 230 under a rail pressure of 1550 bar in the comparative example. It can be seen that curve 1 has a smaller fluctuation range than curve 2. Furthermore, curve 3 was obtained by implementing the embodiment under a rail pressure of 1600 bar. Comparing curves 1 and 3, it can be seen that the pressure pulsation curves are basically consistent, and there is no significant fluctuation change due to the increase in rail pressure. Therefore, it can be proven that the throttling orifice 241 with the above-mentioned aperture can effectively suppress the pulsating impact generated by continuous injection.

[0080] Please refer to this again. Figure 1 In this embodiment, the fuel injector oil quantity measurement structure 10 also includes a cooling and filtering module 300. The cooling and filtering module 300 is disposed between the voltage stabilizing and filtering module 200 and the medium metering module 400, so as to cool and filter the oil before the oil enters the medium metering module 400, thereby ensuring the cleanliness of the oil and the flow meter 412, which helps to ensure measurement accuracy.

[0081] Specifically, the cooling and filtering module 300 includes a plate heat exchanger 311 and a filter 312. The plate heat exchanger 311 is connected to the throttling element 240, thereby cooling the oil leaving the throttling element 240 to adjust the oil temperature and reduce the impact of temperature on measurement accuracy to a certain extent. The filter 312 is located between the plate heat exchanger 311 and the temperature sensor 411, and can precisely filter the oil flowing through the system piping.

[0082] In this embodiment, the fuel injector oil quantity measurement structure 10 further includes a return oil module 500, which is located downstream of the medium metering module 400. Specifically, the return oil module 500 includes a coil 511 and an oil tank 512. The coil 511 is connected to the flow meter 412 and is used to create back pressure in the pipeline flow channel, thus playing a role in stabilizing the pressure of the system pipeline to a certain extent. The oil tank 512 is located at the tail end of the coil 511 and is used to receive the normally flowing liquid oil and the liquid oil remaining in the pipeline.

[0083] Figure 6 This is a flowchart illustrating the fuel injector fuel quantity measurement method provided in this embodiment. Please refer to the attached diagram. Figures 1-6 The present invention also provides a fuel injector fuel quantity measurement method for measuring the flow rate of liquid fuel injected by the fuel injector 111. Specifically, the controller 413 in the above-mentioned fuel injector fuel quantity measurement structure 10 can execute the fuel injector fuel quantity measurement method to obtain an accurate measurement value of the fuel injection quantity of the fuel injector 111. In other words, the fuel injector fuel quantity measurement method can also be regarded as the specific operation process of the controller 413.

[0084] The controller 413 is used to display and calculate the oil quantity value. The oil quantity measurement system software interface is developed based on PLC and LabVIEW software. The PLC collects and controls the oil temperature and the pulse signal data of the gear flow meter 412. The LabVIEW software programming algorithm converts and processes the data, thereby realizing the acquisition, measurement and calculation functions of the entire flow meter 412 system.

[0085] In this embodiment, the fuel injector fuel quantity measurement method includes the following steps:

[0086] S01: Measure the temperature and flow rate of the fuel injected by the fuel injector 111.

[0087] Temperature is measured by temperature sensor 411 to obtain the measured temperature. Flow is measured by flow meter 412 to obtain the measured flow rate.

[0088] S02: Obtain the average volumetric flow rate at the corrected temperature based on the measured temperature and flow rate.

[0089] To eliminate the influence of oil temperature on density and thus ensure the accuracy of flow rate measurement, temperature correction is required to convert the measured flow rate into the volumetric flow rate at the corrected temperature. Specifically, step S02 includes:

[0090] S21: Convert the measured flow rate into the volumetric flow rate at the corrected temperature.

[0091] The measured flow rate is the raw volumetric flow rate. The controller 413 is set with a metering period t, during which multiple measured flow rate signals Q are acquired. T2 Simultaneously, the flow rate signal Q is obtained through the temperature sensor 411. T2 The corresponding measured temperature signal T2 is then used to convert the measured flow rate into the volumetric flow rate at the corrected temperature using the following formula:

[0092]

[0093] Among them, Q T1 To correct the volumetric flow rate at the temperature; Q T2 For measuring flow rate; ρ T2 To measure the density of oil at the specified temperature; ρ T1 To correct the oil density at the correct temperature.

[0094] Flow measurement signal Q T2 Since this is an instantaneous signal, the volumetric flow rate Q at the corrected temperature calculated by the above conversion formula is... T1 This is also the instantaneous flow rate. Therefore, step S02 further includes:

[0095] S22: Calculate the average volumetric flow rate at the corrected temperature based on the volumetric flow meter 412.

[0096] The average volumetric flow rate at the corrected temperature is calculated using the following formula:

[0097]

[0098] Where, ΔQ T1 t represents the average volumetric flow rate; t is the duration of one metering cycle.

[0099] Optionally, in this embodiment, the corrected temperature is 40°C.

[0100] S03: Obtain the flow coefficient corresponding to the average volumetric flow rate.

[0101] To further ensure measurement accuracy, flow correction is also required based on the flow coefficient. Specifically, the controller 413 stores the flow coefficient corresponding to the average volumetric flow rate. After the average volumetric flow rate is calculated, the corresponding flow coefficient stored in the controller 413 can be used for flow correction. Therefore, this fuel injector oil quantity measurement method may also include a step S31 for calculating the flow coefficient, which includes:

[0102] Divide the flow ranges and determine the flow coefficient for each flow curve.

[0103] When dividing the flow rate into intervals, it can be divided into the following intervals: (0 ml / min, 100 ml / min), [100 ml / min, 500 ml / min), [500 ml / min, 1000 ml / min), [1000 ml / min, 2000 ml / min), [2000 ml / min, 3000 ml / min), and [3000 ml / min, 4000 ml / min).

[0104] After dividing the flow range, for each flow range, multiple sets of data on the volumetric flow rate within a metering cycle and the average volumetric flow rate at the corrected temperature are obtained using a gravimetric method. The volumetric flow rate Q obtained by the gravimetric method is... T1称重 and the average volumetric flow rate ΔQ at the corrected temperature T1 Satisfy the following formula:

[0105] Q T1称重 =aΔQ T1 +b;

[0106] Where a and b are flow coefficients.

[0107] The specific values ​​of flow coefficients a and b are obtained by fitting multiple sets of data.

[0108] Specifically, the volumetric flow rate Q obtained by the weighing method T1称重 The following method can be used to calculate the oil volumetric flow rate Q during the same metering period t, obtained by weighing the oil using the gravimetric method. T1称重 :

[0109]

[0110] It should be noted that the specific number of intervals and the traffic range corresponding to each interval are not limited here. It is understood that in some other embodiments, other numbers of intervals and traffic ranges corresponding to each interval can be set as needed. The more traffic intervals there are and the smaller the traffic range corresponding to each interval, the more accurate the final traffic correction data based on the traffic coefficient will be.

[0111] Step S03 includes: determining the flow range to which the average volumetric flow rate belongs, and using the flow coefficient corresponding to the flow range as the flow coefficient corresponding to the average volumetric flow rate. For example, if the calculated average volumetric flow rate is 1500 ml / min, then the flow range of the average volumetric flow rate is [1000 ml / min, 2000 ml / min), and the flow coefficient of the flow range [1000 ml / min, 2000 ml / min) is used as the flow coefficient for flow correction.

[0112] S04: The accurate flow rate of fuel injected by the fuel injector is calculated based on the average volumetric flow rate and the flow coefficient. The accurate flow rate of fuel injector 111 is calculated using the following formula:

[0113] Q′=aΔQ T1 +b

[0114] Where Q′ is the accurate flow rate; ΔQ T1 denoted as average volumetric flow rate; a and b are flow coefficients.

[0115] The accurate flow rate of fuel injected by the fuel injector 111 obtained by the calculation is the final flow rate obtained by the fuel injector fuel quantity measurement method provided in the embodiment of the present invention.

[0116] The fuel injector fuel quantity measurement method and structure provided in the embodiments of the present invention take into account the influence of pressure fluctuations of high-pressure media on flow rate, the influence of ambient temperature on the viscosity of the test medium in high-hydraulic systems, and the influence of different flow ranges on the flow coefficient. It employs a pressure stabilization and damping device, temperature compensation correction, and a method of distinguishing and calculating the flow coefficient for different ranges to measure flow rate, thereby obtaining more accurate flow measurement data. Simultaneously, this fuel injector fuel quantity measurement method and structure also have the advantages of high reliability, simple measurement, and short measurement time, effectively reducing potential technical risks in fuel systems and thus improving efficiency. It can be applied to the research and development and performance verification of fuel injection system products (such as methanol injection systems).

[0117] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for measuring fuel quantity in a fuel injector, characterized in that, The fuel injector fuel quantity measurement method includes: To obtain the measured temperature and flow rate of the fuel injected by the fuel injector; The average volumetric flow rate at the corrected temperature is obtained based on the measured temperature and the measured flow rate. Obtain the flow coefficient corresponding to the average volumetric flow rate; The accurate flow rate ejected by the fuel injector is calculated based on the average volumetric flow rate and the flow coefficient. Prior to the step of obtaining the flow coefficient corresponding to the average volumetric flow rate, the fuel injector oil quantity measurement method further includes: Divide the flow rate into intervals and calculate the flow coefficient for each interval. The step of obtaining the flow coefficient corresponding to the average volumetric flow rate includes: Determine the flow range to which the average volumetric flow rate belongs, and use the flow coefficient corresponding to the flow range as the flow coefficient corresponding to the average volumetric flow rate; The formula for calculating the accurate flow rate of the fuel injector based on the average volumetric flow rate and the flow coefficient is as follows: Q′=aΔQ T1 +b Where Q′ is the accurate flow rate; ΔQ T1 The average volumetric flow rate is given; a and b are flow coefficients.

2. The fuel injector quantity measurement method according to claim 1, characterized in that, The step of obtaining the average volumetric flow rate at the corrected temperature based on the measured temperature and the measured flow rate includes: The measured flow rate is converted into the volumetric flow rate at the corrected temperature using the following formula: Among them, Q T1 Q is the volumetric flow rate at the corrected temperature; T2 The measured flow rate; ρ T2 ρ is the density of the oil at the measured temperature. T1 The oil density at the corrected temperature; The average volumetric flow rate at the corrected temperature is calculated based on the volumetric flow rate, using the following formula: Where, ΔQ T1 The average volumetric flow rate is denoted as t, which is the duration of one metering cycle.

3. The fuel injector quantity measurement method according to claim 1, characterized in that, The steps of dividing the flow rate into intervals and determining the flow rate coefficient for each interval include: The flow rate was divided into the following intervals: (0 ml / min, 100 ml / min), [100 ml / min, 500 ml / min), [500 ml / min, 1000 ml / min), [1000 ml / min, 2000 ml / min), [2000 ml / min, 3000 ml / min), and [3000 ml / min, 4000 ml / min). For each flow range, multiple sets of data on the volumetric flow rate and the average volumetric flow rate at the correction temperature within a metering cycle are obtained using the gravimetric method. The volumetric flow rate Q obtained by the gravimetric method is... T1称重 and the average volumetric flow rate ΔQ at the corrected temperature T1 Satisfy the following formula: Q T1称重 =aΔQ T1 +b; Where a and b are flow coefficients.

4. The fuel injector quantity measurement method according to claim 1, characterized in that, The corrected temperature is 40°C.

5. A fuel injector fuel quantity measurement structure, characterized in that, The fuel injector fuel quantity measurement structure is used to perform the fuel injector fuel quantity measurement method according to any one of claims 1-4; The fuel injector fuel quantity measurement structure includes: The medium metering module is used to acquire the measured temperature and flow rate of the fuel injected by the fuel injector, and to obtain the average volumetric flow rate at a corrected temperature based on the measured temperature and the measured flow rate. Furthermore, the medium metering module is also used to obtain the flow coefficient corresponding to the average volumetric flow rate, and to calculate the accurate flow rate ejected by the fuel injector based on the average volumetric flow rate and the flow coefficient.

6. The fuel injector oil quantity measurement structure according to claim 5, characterized in that, The medium metering module includes a temperature sensor, a flow meter, and a controller. The temperature sensor and the flow meter are both electrically connected to the controller. The temperature sensor is used to acquire the temperature of the fuel injected by the fuel injector and transmit the temperature signal, which characterizes the temperature, to the controller. The flow meter is used to acquire the flow rate of the fuel injected by the fuel injector and transmit the measured flow rate, which characterizes the flow rate, to the controller. The controller is used to obtain the average volumetric flow rate at the corrected temperature based on the measured temperature and the measured flow rate, and to calculate the accurate flow rate of the fuel injector based on the flow coefficient corresponding to the average volumetric flow rate and the average volumetric flow rate.

7. The fuel injector oil quantity measurement structure according to claim 6, characterized in that, The temperature sensor is located upstream of the flow meter.

8. The fuel injector oil quantity measurement structure according to claim 5, characterized in that, The fuel injector oil quantity measurement structure also includes a pressure stabilizing and filtering module, which has an oil inlet and an oil outlet. The oil inlet is used to receive the oil injected by the fuel injector, and the oil outlet is connected to the medium metering module. The pressure stabilizing and filtering module includes a demisting block, a straight pipe, a pressure stabilizing tank, and a throttling device connected in sequence; the oil inlet is the inlet of the demisting block, and the oil outlet is the outlet of the throttling device; the demisting block is used to collect the oil jet ejected by the fuel injector; the straight pipe is used to reduce pressure fluctuations in the oil flow; the pressure stabilizing tank is used to store the oil and stabilize the pressure; the throttling device has a throttling orifice connecting the pressure stabilizing tank and the oil outlet, and the throttling orifice is used to suppress pulsating impacts generated by continuous injection.

9. The fuel injector oil quantity measurement structure according to claim 8, characterized in that, The defogging block includes a connecting channel and a first chamber and a second chamber disposed on both sides of the connecting channel, and the connecting channel connects the first chamber and the second chamber; the oil inlet is formed on the side of the first chamber away from the second chamber, and the side of the second chamber away from the first chamber is connected to the straight pipe; The cross-sectional area of ​​the first chamber is greater than that of the second chamber, the cross-sectional area of ​​the second chamber is greater than that of the connecting channel, and the end of the first chamber that connects to the connecting channel has a first conical surface, and the end of the second chamber that connects to the connecting channel has a second conical surface.

10. The fuel injector oil quantity measurement structure according to claim 8, characterized in that, The diameter of the throttling orifice is 0.8 mm to 1.2 mm.

Images