Pre-priming of a fuel pump, activated by a door sensor

Abstract

A method comprising: supplying fuel to a power engine (102) using a low-pressure fuel pump (144) in fluid connection with a fuel tank (142) and a high-pressure fuel pump (146) in fluid connection with the low-pressure fuel pump (144); and selectively switching on the low-pressure fuel pump (144) when a door is opened before the power engine (102) has been started, the power engine (102) is not currently being cranked, and a distributor pipe pressure of the low-pressure fuel pump (144) is lower than a predetermined pressure.

Description

AREA

[0001] The present disclosure relates to power engine control systems and in particular power engine control systems which automatically prime a pump before cranking a power engine in order to improve the starting of the power engine. BACKGROUND

[0002] The background information provided here serves the purpose of providing a general overview of the context of the disclosure. The work of the inventors currently named, insofar as it is described in this background section, as well as aspects of the description that are not otherwise identified as prior art at the time of filing, are neither explicitly nor implicitly recognized as prior art against the present disclosure.

[0003] Spark-ignition direct injection (SIDI) engines tend to have longer and more inconsistent engine start times. These starting problems arise from variations in the time required to prime a low-pressure fuel pump. SUMMARY

[0004] A power engine control system includes a fuel system comprising a first fuel pump in fluid connection with a fuel tank and a second fuel pump in fluid connection with the first fuel pump. A pump control module selectively activates the first fuel pump when a door is opened before a power engine is started, the power engine is not currently being cranked, and the first fuel pump's distributor pressure is lower than a predetermined distributor pressure.

[0005] In other respects, the engine is a spark-ignition direct injection (SIDI) engine. The pump control module selectively activates the first fuel pump for a predetermined period of time, ranging from 1 to 3 seconds. The pump control module includes a pressure comparator module, which compares the manifold pressure to the predetermined manifold pressure, and a pre-pump actuator module, which communicates with the pressure comparator module. This pre-pump actuator receives an engine off signal, a door open signal, and an engine start signal. Based on these signals, along with an output from the pressure comparator module, the pre-pump actuator primes the first fuel pump.

[0006] In other features, a hood switch deactivation module selectively disables the pre-priming of the first fuel pump by the pump control module when a vehicle's hood is open before the engine is started.

[0007] A method comprises supplying fuel to a power engine using a first fuel pump in fluid connection with a fuel tank and a second fuel pump in fluid connection with the first fuel pump; and selectively activating the first fuel pump when a door is opened before the power engine is started, the power engine is not currently being cranked, and a distributor pipe pressure of the first fuel pump is less than a predetermined pressure.

[0008] In other respects, the engine is a spark-ignition direct injection (SIDI) engine. The procedure involves selectively activating the first fuel pump for a predetermined period of time, ranging from 1 to 3 seconds. The procedure also includes disabling the first fuel pump's priming before the engine is started if the vehicle's hood is open.

[0009] A pump control system includes a pressure comparator module that compares a manifold pressure assigned to a first fuel pump with a predetermined pressure. A pre-pump actuator module communicates with the pressure comparator module, receives an engine-off signal, a door-open signal, and a cranking signal, and causes the first fuel pump to selectively prime for a predetermined period in response to the door-open signal before an engine is started. The cranking signal indicates that the engine is not currently being cranked and the manifold pressure of the first fuel pump is lower than the predetermined pressure.

[0010] In other respects, the engine is a spark-ignition direct injection (SIDI) engine. The predetermined time interval is in the range of 1–3 seconds. A hood switch deactivation module selectively disables the activation of the initial fuel pump before starting if the vehicle's hood is open prior to engine start.

[0011] Further applications of the present disclosure will become apparent from the detailed description provided below. It is understood that the detailed description and specific examples are intended only for illustration and are not meant to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present revelation will be better understood with the help of the detailed description and the accompanying drawings, in which:

[0013] Fig. 1 a functional block diagram of a power machine system comprising a power machine control module, a low-pressure pump (LP pump) and a high-pressure pump (HP pump) according to the present disclosure;

[0014] Fig. 2 a functional block diagram of an LP pre-pump control module according to the present disclosure; and

[0015] Fig. 3 is a flowchart illustrating the operation of the LP pre-pump control module according to the present disclosure. DETAILED DESCRIPTION

[0016] Spark-ignition direct injection (SIDI) engines tend to have longer engine start times and variations in start time, which can lead to customer complaints. Starting problems can arise due to variations in the time required to prime a low-pressure fuel pump (LP fuel pump). In some cases, a vapor lock forms in a fuel line during a hold period. The vapor lock increases the time required to build up fuel pressure for SIDI engines. This increased time to build fuel pressure tends to cause longer start times because many engine control systems delay fuel injection until a target rail pressure is reached.

[0017] Systems and methods according to the present disclosure cause the low-pressure fuel pump (without driver interaction) to automatically prime for a predetermined period of time before a starting device is engaged, in order to improve engine starting time and engine starting time variation. The systems and methods according to the present disclosure compress the vapor bubble before the engine is cranked. By way of example only, the systems and methods according to the present disclosure detect a door-open event when the engine is switched off and not currently being cranked, and cause the low-pressure fuel pump to prime automatically before the engine is cranked, in order to reduce engine starting time and engine starting variation.

[0018] With reference to now Fig. 1 is a functional block diagram of an exemplary power machine system 100The power machine system is shown. 100 contains a power engine 102 , which burns a mixture of air and fuel to generate drive torque for a vehicle. Although the engine 102 The engine, which is discussed as a spark-ignition and direct injection engine (SIDI engine), can be described as follows: 102 include another suitable type of engine, such as a compression-ignition engine. Along with the engine 102 One or more electric motors and / or motor-generator units (MGUs) may be provided.

[0019] Through a throttle valve 108 Air is drawn into an intake manifold. 106 sucked in. The throttle valve 108 Can an airflow enter the intake manifold? 106 to change it. The throttle valve is just one example. 108It includes a butterfly valve with a rotating flap. A power machine control module. 110 controls a throttle valve actuator module 112 (e.g. an electronic throttle controller or ETC) and the throttle actuator module 112 controls the opening of the throttle valve 108 .

[0020] Air from the intake manifold 106 is in the cylinder of the engine 102 sucked in. Although the powerhouse 102 It can contain more than one cylinder, but only a single representative cylinder is possible. 114 Shown. Air from the intake manifold. 106 is passed through an inlet valve 118 into the cylinder 114 Intake. One or more intake valves can be provided for each cylinder.

[0021] The power machine control module 110 controls a fuel actuator module 120 and the fuel actuator module 120controls the injection of fuel (e.g., the amount and timing) through a fuel injector. 121 The power machine control module 110 Fuel injection can be used to control the amount of fuel injected to achieve a desired air-to-fuel ratio, approximately a stoichiometric ratio. Although it is shown and discussed that fuel is injected directly into the cylinder... 114 While fuel is injected in one location, in other types of engines, fuel can be injected at other points, such as into the intake manifold. 106 near the intake valves of the cylinders or in mixing chambers connected to the cylinders. A fuel injector can be provided for each cylinder.

[0022] The injected fuel mixes with air, creating a mixture of air and fuel in the cylinder. 114 Based on a signal from the power machine control module110 can an ignition spark actuator module 122 a spark plug 124 in the cylinder 114 excite. A spark plug can be provided for each cylinder. A spark plug 124 The generated spark ignites the air-fuel mixture. In engines with compression ignition, the heat generated by compression causes ignition, as does the operation of an engine in a compression ignition mode (e.g., homogeneous charge compression ignition).

[0023] The power machine 102 It can operate using a four-stroke cycle. The four strokes described below can be referred to as the intake stroke, compression stroke, power stroke, and exhaust stroke. During each revolution of a crankshaft (not shown), two of the four strokes occur in the cylinder. 114 Therefore, two crankshaft revolutions are necessary for the cylinders to complete all four strokes.

[0024] During the intake stroke, air is drawn from the intake manifold. 106 through the inlet valve 118 into the cylinder 114 The injected fuel mixes with the air, creating a mixture of air and fuel in the cylinder. 114 During the compression stroke, a piston (not shown) compresses the mixture of air and fuel in the cylinder. 114 During the power stroke, the combustion of the air-fuel mixture drives the piston, which in turn drives the crankshaft. During the exhaust stroke, the combustion byproducts are expelled through an exhaust valve. 126 in an exhaust system 127 expelled.

[0025] A valve actuator module 130 controls the opening and closing of the intake and exhaust valves of the engine 102 based on signals from the power engine control module 110 In particular, an inlet valve actuator controls134 the actuation (opening, closing and stroke) of the inlet valve 118 An exhaust valve actuator 138 controls the actuation (opening, closing and stroke) of the exhaust valve 126 The valve actuator module 130 controls the intake and exhaust valve actuators 134 and 138 based on signals from the power engine control module 110 .

[0026] An LP fuel pump 142 supplies fuel from a fuel tank 140 with a first distribution pipe pressure. A high-pressure fuel pump (HP fuel pump) 144 receives fuel from the LP fuel pump 142 and delivers fuel at a second distributor pipe pressure that is greater than the first distributor pipe pressure. A pump actuator 158 can be used to power the LP fuel pump 142 and the HP fuel pump 144to control. Alternatively, the LP fuel pump can be used. 142 and the HP fuel pump 144 are directly controlled by the power unit control module. A first pressure sensor 166 measures the initial distributor pipe pressure at one outlet of the LP fuel pump. 144 A second pressure sensor 168 detects the second distributor pipe pressure at one outlet of the HP fuel pump 146 .

[0027] A crankshaft position sensor 170 It monitors the rotation of the crankshaft and generates a crankshaft position signal based on this rotation. The crankshaft position sensor is just one example. 170 includes a variable reluctance sensor (VR sensor) or another suitable type of crankshaft position sensor.

[0028] The crankshaft position sensor 170can generate impulses in the crankshaft position signal when teeth of a toothed wheel contact the crankshaft position sensor 170 The toothed wheel rotates along with the crankshaft. Each pulse corresponds to an angular rotation of the crankshaft by an amount approximately equal to 360° divided by the number of teeth on the toothed wheel. The toothed wheel may also contain a gap of one or more missing teeth, and the gap can be used to indicate a complete revolution of the crankshaft (i.e., 360° of crankshaft rotation). A cylinder pressure sensor (not shown) may be provided to measure the pressure in the cylinder. 114 to measure and generate a cylinder pressure signal based on the pressure. A cylinder pressure sensor can be provided for each cylinder of the engine. In some examples, the pressure in the cylinder can be measured. 114(the cylinder pressure) can be estimated (determined) based on one or more other parameters.

[0029] One or more other sensors may also be used. 178 be implemented. The other sensors 178 These may include, for example, a mass airflow sensor (MAF sensor), a manifold absolute pressure sensor (MAP sensor), an intake air temperature sensor (IAT sensor), a coolant temperature sensor, an oil temperature sensor and / or one or more other suitable sensors.

[0030] The power machine control module 110 includes an LP pump control module 180 , that the LP fuel pump 144 It automatically controls the system to reduce the start-up time and any fluctuations in that time. In some implementations, a door sensor detects the start-up time. 190 the opening of a vehicle door (a door-opening event) and communicates with a vehicle control module192 or directly with the power machine control module 110 A hood switch 192 It detects when the vehicle's hood is opened. (Just as an example, the vehicle controller communicates...) 192 via a controller area network bus (CAN bus) with the power machine control module 110 .

[0031] With reference to now Fig. 2 is an example of the LP pump control module 180 shown in greater detail. The LP pump control module 180 includes a pre-pump actuator module 200 , a timer 210 and a pressure comparison module 214 The pre-pump actuator module 200 It receives signals indicating power machines are switched off, doors are open, and power machines are being cranked up. The pressure comparison module 214 receives a distributor pipe pressure signal from the LP fuel pump 144 When the engine is switched off and the door sensor is off 190Once the door is detected being opened, the pre-pump actuator module switches on. 200 The LP fuel pump runs for a predetermined period of time, which is determined by the timer. 210 This is determined when the engine is not being cranked and the pressure comparison module detects that the manifold pressure is lower than a predetermined manifold pressure limit. In some examples, the time interval set by the timer may be in the range of 1–3 seconds, although other time intervals can be used. A hood-open deactivation module 218 It receives a hood-open signal and selectively deactivates the pre-pump actuator module. 200 , if the hood is open before starting, when the door-open signal is received.

[0032] With reference to now Fig. Figure 3 shows an example of a method for automatically pre-priming an LP pump. 300The control unit detects whether the vehicle door is open and the engine is not running. If this is not the case, the control unit returns to... 300 back. If 300 That is true, the control at 310 determines whether a hood switch test is activated. If 310 if this is true, the control system will then 314 Determine whether the hood is open. If 314 If true, the control returns to 300 back. If 314 does not apply or the hood switch test at 310 When deactivated, the control system moves with 318 on. At 318 The control system determines whether there is currently no cranking action and whether the distributor pipe pressure is lower than a predetermined distributor pipe pressure limit. 318 That is true, the control system drives with 322 continues and switches on the LP fuel pump for a predetermined period of time. 326The control unit switches off the fuel pump after the predetermined time period and the control process ends. 318 If the error is incorrect, the control process ends.

[0033] The foregoing description is merely exemplary and is in no way intended to limit the revelation, its application, or its uses. The broad teachings of revelation can be implemented in a variety of forms. Although this revelation contains specific examples, the actual scope of revelation is therefore not to be limited to them, since other modifications will be revealed upon study of the drawings, the description, and the following claims. For clarity, the same reference symbols are used in the drawings to denote similar elements. When used herein, the expression A, B, and / or C shall be understood to mean a logical (A or B or C) using a non-exclusive logical OR.It is understood that one or more steps in a process may be carried out in a different order (or simultaneously) without altering the principles of the present disclosure.

[0034] When used herein, the term "module" can refer to, be part of, or include an application-specific integrated circuit (ASIC), an electronic circuit, a combinational logic circuit, a field-programmable gate array (FPGA), a processor (shared, dedicated, or group) that executes code, other suitable hardware components that provide the described functionality, or a combination of some or all of the foregoing, such as in a system-on-a-chip. The term "module" can also include memory (shared, dedicated, or group) that stores code to be executed by the processor.

[0035] The term "code," as used above, can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, and / or objects. The term "shared," as used above, means that some or all of the code from multiple modules can be executed using a single (shared) processor. Furthermore, some or all of the code from multiple modules can be stored in a single (shared) memory location. The term "group," as used above, means that some or all of the code from a single module can be executed using a group of processors. Furthermore, some or all of the code from a single module can be stored using a group of memory locations.

[0036] The devices and methods described here can be implemented by one or more computer programs executed by one or more processors. The computer programs contain instructions executable by a processor, stored on a non-temporary, concrete, computer-readable medium. The computer programs may also contain stored data. Examples, without limitation, of the non-temporary, concrete, computer-readable medium include non-volatile memory, magnetic mass storage, and optical mass storage.

Claims

[1] Procedure that includes: Fuel is supplied to a power engine using a first fuel pump in fluid connection with a fuel tank and a second fuel pump in fluid connection with the first fuel pump; and The first fuel pump is selectively activated when a door is opened before the engine has been started, the engine is not currently being cranked, and the distributor pipe pressure of the first fuel pump is lower than a predetermined pressure. [2] Method according to claim 1, wherein the engine is a spark ignition and direct injection engine (SIDI engine). [3] Method according to claim 1, further comprising that the first fuel pump is selectively switched on for a predetermined period of time. [4] Method according to claim 3, wherein the predetermined time interval is in the range of 1–3 seconds. [5] The method of claim 1, further comprising deactivating the pre-pumping of the first fuel pump before the engine is started when the hood of a vehicle containing the engine is open.

Images