JP2018105246A - Fluid injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contribute to the improvement of a variation of an actual injection amount.SOLUTION: A fluid injection device injects fluid in a nozzle chamber from an injector having a body in which an injection hole is formed, a needle for opening and closing the injection hole by vertical movement, the nozzle chamber in which a tip portion of the needle is accommodated, and a flow passage communicating with the nozzle chamber, and guiding the supplied fluid to the nozzle chamber. The fluid injection device comprises: a detection part for detecting the displacement of a diameter of the flow passage, and outputting a signal corresponding to the displacement; an input part for inputting the signal; and a calculation part for calculating the quantity of the fluid which is actually injected on the basis of a time at which the signal is outputted, and a magnitude of the signal.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fluid ejecting apparatus.

  2. Description of the Related Art Conventionally, a fluid ejecting apparatus that ejects a fluid (also referred to as a liquid) such as fuel or a reducing agent is known as an apparatus mounted on a vehicle.

  For example, Patent Document 1 discloses a technique for measuring the flow rate of fuel supplied to a fuel injection device with a flow meter and controlling the fuel injection amount based on the measurement result.

JP 2011-173536 A

  In a fuel injection device, for example, when a spring that moves a needle up and down deteriorates over time, the amount of fuel actually injected (hereinafter referred to as an actual injection amount) varies. In order to improve this variation, it is conceivable to perform feedback control for controlling the injection amount using the actual injection amount.

  However, with the technique of Patent Document 1, the flow rate of the fuel supplied to the fuel injection device can be measured, but the actual injection amount cannot be measured (calculated). Therefore, the variation in the actual injection amount could not be improved.

  An object of the present invention is to provide a fluid ejecting apparatus that can contribute to improvement in variation in actual ejection amount.

  The fluid ejection device according to the present invention communicates with a body in which a nozzle hole is formed, a needle that opens and closes the nozzle hole by vertical movement, a nozzle chamber in which a tip portion of the needle is accommodated, and the nozzle chamber. A fluid ejecting apparatus for ejecting fluid in the nozzle chamber from an injector having a flow path for guiding the fluid to the nozzle chamber, and detecting a displacement of the diameter of the flow path and a signal corresponding to the displacement A detection unit that outputs the signal, an input unit that inputs the signal, a calculation unit that calculates the amount of fluid actually ejected based on the time when the signal was output, and the magnitude of the signal, Prepare.

  According to the present invention, it is possible to contribute to improvement in variation in the actual injection amount.

Sectional drawing which shows the structural example of the fuel-injection apparatus which concerns on embodiment of this invention The block diagram which shows the structural example of the control part of the fuel-injection apparatus which concerns on embodiment of this invention. The figure which uses for description of the calculation process of the actual injection quantity which concerns on embodiment of this invention

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  A configuration of a fuel injection device (an example of a fluid injection device) according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing a configuration example of the fuel injection device according to the present embodiment. FIG. 2 is a block diagram illustrating a configuration example of a control unit of the fuel injection device according to the present embodiment.

  The fuel injection device shown in FIG. 1 is, for example, a common rail fuel injection device for a diesel engine mounted on a vehicle.

  As shown in FIG. 1, the fuel injection device includes a fuel tank 1, a pressure pump 2, an injection pump 3, a common rail 4, an injector 10, a displacement detection unit 30, and a control unit 5.

  The fuel tank 1 stores fuel (an example of fluid) such as light oil and DME.

  The pressure pump 2 pumps the fuel in the fuel tank 1 to the engine side.

  The injection pump 3 boosts the fuel pumped by the pumping pump 2 to a predetermined injection pressure (common rail pressure, for example, about several tens to several hundreds of MPa).

  The common rail 4 accumulates (stores) the high-pressure fuel boosted by the injection pump 3. The common rail 4 is connected to the fuel tank 1 by a fuel supply line 6. A pressure feed pump 2 and an injection pump 3 are arranged in the fuel supply line 6 in order from the upstream side. The common rail 4 is connected to an injector 10 by a high pressure pipe 7.

  The controller 5 controls the injection timing of the injector 10, the number of injections, the operating pressure (common rail pressure) of the injection pump 3, and the like. The control unit 5 will be described later with reference to FIG.

  The displacement detector 30 is provided on the surface of the body 12 corresponding to the position of the flow path 26 formed inside the body 12 of the injector 10. The installation position of the displacement detector 30 may be in the range A shown in FIG.

  Before and after fuel injection, the flow rate of fuel in the flow path 26 changes, so the diameter of the flow path 26 is displaced. The displacement detection unit 30 detects a displacement of the diameter of the flow path 26 and outputs a voltage corresponding to the displacement (hereinafter referred to as an output voltage, an example of a signal) to the control unit 5. Examples of the displacement detection unit 30 include a piezoelectric element, a capacitance sensor, and an electromagnetic induction sensor. However, the displacement detection unit 30 is not limited thereto, and any means capable of detecting the displacement of the diameter of the flow path 26 may be used.

  The injector 10 is a solenoid-driven injector, and injects fuel distributed and supplied from the common rail 4 through the high-pressure pipe 7 into the combustion chamber of the engine. The injector 10 is connected to the fuel tank 1 via a fuel return line 8 for returning surplus fuel. An injection pump 3 is connected to the fuel return line 8 via an injection pump return pipe 9.

  Next, the configuration of the injector 10 will be described.

  The injector 10 extends in the vertical direction, has a body 12 having a nozzle hole 11 formed at the lower end (tip), a needle 14 that is accommodated in the body 12 and opens and closes the nozzle hole 11 by moving in the vertical direction, and a needle 14, a nozzle chamber 23 in which the tip portion (for example, the valve body 19) is accommodated, and a flow path 26 that communicates with the nozzle chamber 23 and guides the fuel supplied from the high-pressure pipe 7 to the nozzle chamber 23.

  The needle 14 has a command piston 15, a nozzle piston 18, and a valve body 19 in order from the top.

  The upper surface 20 of the command piston 15 receives a pressure (fuel pressure) from the high-pressure fuel in the control chamber 21 and functions as a valve-closing pressure receiving surface for moving the needle 14 downward (in the valve-closing direction). Further, the lower surface 22 of the nozzle piston 18 (excluding the connection portion with the valve body 19) receives the fuel pressure in the nozzle chamber 23 and serves as a valve-opening pressure-receiving surface for moving the needle 14 upward (in the opening direction). Function.

  A spring 29 that biases the nozzle piston 18 downward is provided between the command piston 15 and the nozzle piston 18.

  The control chamber 21 is formed above the command piston 15. An inlet orifice 34 and an outlet orifice 35 are formed in the control chamber 21.

  The inlet orifice 34 is connected to a flow path 26 formed in the body 12. High pressure fuel for moving the command piston 15 downward (in the closing direction of the needle 14) is introduced into the control chamber 21 from the inlet orifice 34.

  The outlet orifice 35 is opened and closed by a control valve 36 (for example, a 2-way valve). The outlet orifice 35 is connected to a return oil passage 27 formed in the body 12. The return oil passage 27 is connected to the fuel return line 8.

  The control valve 36 includes an armature 38 that opens and closes the outlet orifice 35, an armature spring 39 that biases the armature 38 downward (close direction), and an armature 38 that moves upward (open direction) against the biasing force of the armature spring 39. And a solenoid (electromagnet) 40 that moves to the center.

  The injector 10 configured as described above is connected to the control unit 5 and receives a control signal for controlling the injection timing and the number of injections from the control unit 5. Specifically, the control unit 5 is connected to the solenoid 40 of the control valve 36, and switches the solenoid 40 to an energized state when the injector 10 is opened and switches the solenoid 40 to a non-energized state when the injector 10 is closed, thereby controlling the opening and closing of the injector 10. To do.

  Next, the opening / closing operation of the injector 10 will be described.

  When the injector 10 is not injecting, the solenoid 40 of the control valve 36 is not energized, and the exit orifice 35 of the control chamber 21 is closed by the armature 38. At this time, as the force in the valve closing direction, the needle 14 has a downward force that the upper surface 20 (the valve-closing pressure receiving surface) of the command piston 15 receives from the fuel in the control chamber 21, and the upper surface of the nozzle piston 18 has a spring 29. And a downward force received from the fuel in the nozzle chamber 23 acts on the lower surface 22 (valve-opening pressure receiving surface) of the nozzle piston 18. When there is no injection, the downward force acting on the needle 14 exceeds the upward force, the needle 14 is urged downward, and the valve body 19 of the needle 14 is seated on the valve seat 47 of the body 12. The nozzle body 23 and the injection hole 11 are blocked by the valve body 19, and fuel is not injected from the injection hole 11.

  At the time of injection of the injector 10, the solenoid 40 of the control valve 36 is energized, and the armature 38 is lifted (moved upward) away from the outlet of the outlet orifice 35 of the control chamber 21. As a result, the fuel in the control chamber 21 flows out from the outlet orifice 35, the pressure in the control chamber 21 decreases, and the upper surface 20 (the valve-closing pressure receiving surface) of the command piston 15 receives downward from the fuel in the control chamber 21. The power of is reduced. When the downward force acting on the needle 14 is reduced due to the pressure drop in the control chamber 21 and the downward force acting on the needle 14 is less than the upward force, the needle 14 is biased upward and lifted (moved upward). ) As a result, the valve body 19 of the needle 14 is separated from the valve seat 47 of the body 12 so that the nozzle chamber 23 and the injection hole 11 communicate with each other, and the fuel in the nozzle chamber 23 is injected from the injection hole 11.

  Next, a configuration example of the control unit 5 will be described with reference to FIG. FIG. 2 is a block diagram illustrating a configuration example of the control unit 5.

  The control unit 5 includes an input unit 51 and a calculation unit 52. Although not shown, the control unit 5 includes, for example, a CPU (Central Processing Unit), a storage medium such as a ROM (Read Only Memory) storing a control program, a working memory such as a RAM (Random Access Memory), and a communication It has a circuit. The functions of the input unit 51 and the calculation unit 52 are realized by the CPU executing a control program.

  The input unit 51 receives the output voltage from the displacement detection unit 30 and outputs the output voltage to the calculation unit 52.

  The calculation unit 52 calculates the amount of fuel (actual injection amount) actually injected by the injector 10 based on the output voltage from the input unit 51. An example of this calculation process will be described with reference to FIG. In FIG. 3, the vertical axis indicates the output voltage, and the horizontal axis indicates the elapsed time.

  For example, it is assumed that the output voltage is lower than the reference voltage d (a value known to the calculation unit 52) from timing s to timing e. In this case, the calculation unit 52 performs integration for each unit time t in the period from the timing s to the timing e to calculate the area a. Then, the calculation unit 52 identifies the actual injection amount corresponding to the calculated area a from reference data such as a table in which the area and the actual injection amount are associated in advance. The reference data may be stored in the control unit 5 (calculation unit 52), or may be read out from a storage unit (not shown) other than the control unit 5 by the control unit 5 (calculation unit 52).

  The actual injection amount calculated in this way is used for feedback control performed by the control unit 5, for example. Alternatively, the control unit 5 may output information indicating the calculated actual injection amount to a predetermined device.

  As described above, according to the present embodiment, the actual injection amount is determined based on the magnitude of the voltage output according to the displacement of the flow path 26 during fuel injection and the time when the voltage is output. It can be calculated. Therefore, by performing feedback control using the actual injection amount, it is possible to contribute to improvement in variation in the actual injection amount.

  In addition, according to the present embodiment, since the displacement detection unit 30 is provided on the outer surface of the body 12 of the injector 10, it is necessary to make a hole in the body 12 in order to install the sensor in the flow path 26 as in the past. There is no. Therefore, the processing cost for opening the hole can be reduced, or a problem that the fluid leaks from the hole does not occur.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present invention.

  For example, in the above embodiment, the fuel injection device has been described as an example of the fluid injection device of the present invention, but the present invention is not limited to this. The fluid ejection device of the present invention may be, for example, gasoline, urea water, or an ejection device that ejects water.

<Summary of this disclosure>
The fluid ejection device according to the present invention communicates with a body in which a nozzle hole is formed, a needle that opens and closes the nozzle hole by vertical movement, a nozzle chamber in which a tip portion of the needle is accommodated, and the nozzle chamber. A fluid ejecting apparatus for ejecting fluid in the nozzle chamber from an injector having a flow path for guiding the fluid to the nozzle chamber, and detecting a displacement of the diameter of the flow path and a signal corresponding to the displacement A detection unit that outputs the signal, an input unit that inputs the signal, a calculation unit that calculates the amount of fluid actually ejected based on the time when the signal was output, and the magnitude of the signal, Prepare.

  In the fluid ejecting apparatus, the detection unit may be provided on a surface of the body corresponding to a portion where the flow path is formed.

  In the fluid ejecting apparatus, the detection unit may be a capacitance sensor, an electromagnetic induction sensor, or a piezoelectric element.

  The present invention can be applied to a fluid ejecting apparatus.

DESCRIPTION OF SYMBOLS 1 Fuel tank 2 Pressure pump 3 Injection pump 4 Common rail 5 Control part 6 Fuel supply line 7 High pressure pipe 8 Fuel return line 9 Injection pump return pipe 10 Injector 11 Injection hole 12 Body 14 Needle 15 Command piston 18 Nozzle piston 19 Valve body 20 Command Upper surface of piston 21 Control chamber 22 Lower surface of nozzle piston 23 Nozzle chamber 26 Flow path 27 Return oil path 29 Spring 30 Displacement detector 34 Inlet orifice 35 Outlet orifice 36 Control valve 38 Armature 39 Armature spring 40 Solenoid 47 Valve seat

Claims (3)

A body in which an injection hole is formed, a needle that opens and closes the injection hole by vertical movement, a nozzle chamber in which a tip portion of the needle is accommodated, and a fluid supplied to the nozzle chamber. A fluid ejecting apparatus that ejects fluid in the nozzle chamber from an injector including a flow path for guiding;
A detector that detects a displacement of the diameter of the flow path and outputs a signal corresponding to the displacement;
An input unit for inputting the signal;
A calculation unit that calculates the amount of fluid actually ejected based on the time when the signal was output and the magnitude of the signal;
A fluid ejection device comprising: The detector is
Provided on the surface of the body corresponding to the formation part of the flow path,
The fluid ejecting apparatus according to claim 1. The detector is
Either a capacitance sensor, an electromagnetic induction sensor, or a piezoelectric element,
The fluid ejection device according to claim 1 or 2.

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