CN112696268B

CN112696268B - Fuel injector cleaning systems, fluids, and methods

Info

Publication number: CN112696268B
Application number: CN202011626154.3A
Authority: CN
Inventors: 迈克尔·A·卢卡斯; 阿斯温·穆图库马尔; 约戈什·加亚纳恩·达塔尔
Original assignee: Cummins Inc
Current assignee: Cummins Inc
Priority date: 2017-04-27
Filing date: 2017-04-27
Publication date: 2022-07-26
Anticipated expiration: 2037-04-27
Also published as: CN112696268A; CN108798895B; CN108798895A

Abstract

Fuel injector cleaning systems, fluids, and methods are disclosed. A fuel injector cleaning system includes an injector cleaning housing defining a cavity configured to receive a fuel injector. A heater operably coupled to the housing. A three-way valve including a first inlet fluidly coupled to the calibration fluid reservoir and a second inlet fluidly coupled to the cleaning fluid reservoir. An input line including a first end fluidly coupled to the outlet of the valve and a second end configured to fluidly couple to a fuel inlet of the fuel injector. A controller operably coupled to each of the heater and the valve. The controller is configured to actuate the valve to flow the cleaning fluid to the fuel injector. The heater is operated to heat the cleaning fluid. The valve is actuated to flow calibration fluid to the fuel injector.

Description

Fuel injector cleaning systems, fluids, and methods

The present application is a divisional application entitled "fuel injector cleaning system, fluid, and method" filed on 2017, 27/04, with application number 201710287187.1.

Technical Field

The present disclosure relates generally to the field of fuel injector cleaning systems and fluids.

Background

Internal combustion engines include fuel injectors configured to inject fuel into combustion chambers of the engine. Properly functioning fuel injectors inject fuel in a form that enables a clean, optimally atomized mist to be burned to optimize engine performance and minimize emissions. However, deposits from impurities in the fuel may accumulate on the fuel injector over time. Such deposits may interfere with the operation of precisely controlled fuel injectors, thereby reducing engine performance, for example, by reducing power output, increasing the frequency of hard starts, reducing fuel economy, and increasing emissions.

Summary of the invention

Various embodiments relate to fuel injector cleaning systems. In one exemplary embodiment, a fuel injector cleaning system includes an injector cleaning housing defining a cavity configured to receive a fuel injector. A heater is operatively coupled to the injector cleaning housing for controllably heating the injector cleaning housing. The three-way valve is configured to controllably allow fluid flow from at least one of the first inlet and the second inlet to the outlet. The first inlet is fluidly coupled to the calibration fluid reservoir and the second inlet is fluidly coupled to the cleaning fluid reservoir. The input line includes a first end and a second end. A first end is fluidly coupled to the outlet of the three-way valve, and a second end is configured to be fluidly coupled to a fuel inlet of a fuel injector. A controller is operably coupled to each of the heater and the three-way valve. The controller is configured to actuate the three-way valve to flow cleaning fluid from the cleaning fluid reservoir to the fuel injector. The heater is operated to heat the cleaning fluid in the injector cleaning housing. The three-way valve is actuated to flow calibration fluid from the calibration fluid reservoir to the fuel injector.

In one embodiment, the cleaning fluid comprises a mixture comprising water in the range of 78% to 82% by weight, ethanol in the range of 14% to 18% by weight, and sulfamic acid in the range of 1% to 3% by weight.

In one embodiment, the fuel injector cleaning system further comprises an injector driver operably coupled to the controller and configured to be operably coupled to the fuel injector, the injector driver configured to controllably actuate the fuel injector.

In one embodiment, the controller is configured to actuate the fuel injector when the cleaning fluid is applied to the fuel injector.

In one embodiment, the heater is positioned on the injector cleaning housing so as to be proximate to a nozzle of the fuel injector positioned in the injector cleaning housing.

In one embodiment, the fuel injector cleaning system further comprises: a first supply line fluidly coupling the calibration fluid reservoir and a first inlet of the three-way valve; a second supply line fluidly coupling the cleaning fluid reservoir and a second inlet of the three-way valve; a first pump operably coupled to the first supply line so as to pressurize the calibration fluid flowing through the first supply line; and a second pump operably coupled to the second supply line so as to pressurize the cleaning fluid flowing through the second supply line.

In one embodiment, the first pump is a hydraulic manual pump.

In one embodiment, the second pump is a reciprocating fluid pump.

Various other embodiments relate to methods of cleaning fuel injectors. In an exemplary method, a sulfamic acid based cleaning fluid is applied to a fuel injector. The cleaning fluid is pressurized to a predetermined pressure. The cleaning fluid is heated to a predetermined temperature. The fuel injector is flushed with a calibration fluid.

In one embodiment, the cleaning fluid applied to the fuel injector is simultaneously pressurized and heated.

In one embodiment, the method further comprises actuating the fuel injector when the cleaning fluid is applied to the fuel injector.

In one embodiment, the method further comprises draining the cleaning fluid from the fuel injector prior to flushing the fuel injector with the calibration fluid.

In one embodiment, the method further comprises, prior to applying the cleaning fluid: pressurizing the fuel injector; and monitoring pressure loss over time to estimate seat integrity of the fuel injector.

In one embodiment, the method further comprises: wherein applying the cleaning fluid to the fuel injector comprises actuating a three-way valve to cause the cleaning fluid to flow from a cleaning fluid reservoir to the fuel injector; wherein flushing the fuel injector with the calibration fluid comprises actuating the three-way valve to stop the flow of the cleaning fluid and flow the calibration fluid from a calibration fluid reservoir to the fuel injector.

Various other embodiments relate to fuel injector cleaning fluids. An exemplary fuel injector cleaning fluid is a mixture including water in a range of 78% to 82% by weight, ethanol in a range of 14% to 18% by weight, and sulfamic acid in a range of 1% to 3% by weight.

In one embodiment, the sulfamic acid is 2.05% by weight of the mixture.

In one embodiment, the water is 81.80% by weight of the mixture.

In one embodiment, the ethanol is 16.15% of the mixture by weight.

In one embodiment, the sulfamic acid is 2.05 percent by weight of the mixture, wherein the water is 81.80 percent by weight of the mixture, and wherein the ethanol is 16.15 percent by weight of the mixture.

These and other features, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described below.

Drawings

The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the disclosure will become apparent from the description, the drawings, and the claims.

FIG. 1 is a schematic illustration of a fuel injector cleaning system according to an exemplary embodiment.

FIG. 2 is a block diagram of a controller of the fuel injector cleaning system of FIG. 1.

FIG. 3 is a flow chart illustrating a method of cleaning a fuel injector according to an exemplary embodiment.

It will be appreciated that some or all of the figures are schematic representations for purposes of illustration. The drawings are provided for the purpose of illustrating one or more implementations, and it is to be expressly understood that they are not intended to limit the scope or meaning of the claims.

Detailed Description

Fuel injectors are susceptible to fouling by contaminating deposits, such as sulfates from particulate matter, atmospheric pollution, and water present in the fuel. The frequency and severity of fuel injector fouling depends at least in part on the quality of the fuel used by the fuel injectors. The fuel pollution standard varies from country to country. For this reason, the problem of fouling of fuel injectors in some countries is more problematic than in others.

Various cleaning fluids (also referred to as cleaning solutions) and cleaning systems for cleaning fuel injectors are currently available. For example, some existing cleaning fluids use hydrochloric acid, phosphoric acid, carboxylic acids, and other types of acids. While such cleaning fluids may remove particulate deposits, they may cause corrosion of the fuel injector. Such cleaning fluids may also be hazardous to handle. Thus, in some cases, these cleaning fluids can only be used by certified technicians with specialized equipment. Thus, some fuel injector purge fluids are not suitable for use in some service garages.

Various embodiments relate to cleaning fluids based on sulfamic acid. For example, in some embodiments, the cleaning fluid is an aqueous solution of sulfamic acid and ethanol. In some embodiments, the sulfamic acid based cleaning fluid comprises ethanol, water, and no more than 2% sulfamic acid. In some embodiments, the sulfamic acid-based cleaning fluid comprises a mixture consisting of water, ethanol, and 2% sulfamic acid. In some embodiments, the sulfamic acid-based cleaning fluid comprises ethanol, sulfamic acid, and 80% water. In some embodiments, the sulfamic acid based cleaning fluid comprises the ranges of 78-82% water, 1-3% sulfamic acid, and 14-18% ethanol (all ranges are included). In a particular embodiment, the sulfamic acid is 2.05% of the mixture, the water is 81.80% of the mixture, and wherein the ethanol is 16.15% of the mixture. As used herein, the mixture of the constituents of the sulfamic acid-based cleaning fluid is determined by weight. In various embodiments, the sulfamic acid-based cleaning fluid does not include any acids other than sulfamic acid. For example, the sulfamic acid based cleaning fluid does not include any of hydrochloric acid, phosphoric acid, and carboxylic acid. It should be understood that although the percentages of the constituents of the sulfamic acid-based cleaning fluid are described herein as specific values, each percentage is intended to include a range that includes a percentage of the total mixture ± 1%.

The sulfamic acid based cleaning fluids of the present invention provide various technical advantages over existing fuel injector cleaning fluids. For example, a particular composition of sulfamic acid based cleaning fluid, including a particular ratio of water, ethanol and sulfamic acid, when used in combination with heat and pressure, provides superior performance in cleaning deposits from fuel injectors (e.g., sulfate based and calcium based deposits) as compared to existing cleaning fluids. In some embodiments, the sulfamic acid-based cleaning fluid is configured for use at a temperature of about 200 degrees fahrenheit and a pressure of about 1000psi to clean the fuel injector. In some embodiments, the sulfamic acid-based cleaning fluid is configured for use at temperatures above 200 degrees fahrenheit and pressures above 1000psi to clean fuel injectors.

Cleaning fluids based on sulfamic acid are also more environmentally friendly and widely available than existing fuel injector cleaning fluids. Some existing fuel injector cleaning fluids include higher acid concentrations than the sulfamic acid based purge fluids of the present invention. In addition, some existing fuel injector cleaning fluids include certain acids or other chemicals that are more hazardous to humans or the environment than sulfamic acid based cleaning fluids. Thus, sulfamic acid based cleaning fluids can be used in many different types of service garages, not just those with certified technicians and/or specialized equipment. Furthermore, because the sulfamic acid based cleaning fluid is water-based and water is denser than the fuel, during cleaning, the sulfamic acid based cleaning fluid settles at the bottom of the fuel injector, thereby diverting any residual fuel out of the fuel injector, thereby facilitating thorough cleaning.

Various other embodiments are directed to a fuel injector cleaning system configured to clean a fuel injector using a sulfamic acid-based cleaning fluid. According to various embodiments, the fuel injector cleaning system is configured to apply a sulfamic acid based cleaning fluid to the fuel injector at a specific temperature and pressure (e.g., about 200 degrees fahrenheit and about 1000psi) in order to remove sulfate-based and other deposits from the fuel injector. In some embodiments, the fuel injector cleaning system applies a sulfamic acid based cleaning fluid to the fuel injector during a first phase of the cleaning cycle, and then flushes the fuel injector with the calibration fluid during a second phase of the cleaning cycle. Flushing the fuel injector with the calibration fluid helps to prevent any potential corrosion of the fuel injector.

The fuel injector cleaning systems described herein provide various technical advantages over existing fuel injector cleaning systems. For example, the fuel injector cleaning system of the present invention configured to apply a sulfamic acid based cleaning fluid to a fuel injector at a particular temperature and pressure has been found to have superior cleaning results as compared to prior systems. Further, the fuel injector cleaning system of the present invention utilizes relatively inexpensive and readily available components, thereby requiring less capital investment than existing industrial fuel injector cleaning systems. Further, the fuel injector cleaning system of the present invention cleans the injector without requiring disassembly of the injector. Thus, this technical advantage allows for widespread adoption of the fuel injector cleaning system of the present invention in factories and garages to restore a fouled injector to proper operation, rather than simply discarding the fouled injector.

FIG. 1 is a schematic illustration of a fuel injector cleaning system 100 according to an exemplary embodiment. The fuel injector cleaning system 100 is configured to remove particulate matter (e.g., sulfate-based) deposits from the fuel injectors. According to various embodiments, the fuel injector cleaning system 100 is configured to utilize a sulfamic acid based cleaning fluid. More specifically, in some embodiments, the fuel injector cleaning system 100 is configured to utilize sulfamic acid based cleaning fluids described herein, including any of the mixtures/formulations disclosed herein. The fuel injector cleaning system 100 is configured to utilize heat and pressure in combination with a sulfamic acid-based cleaning fluid in order to provide superior cleaning results compared to existing cleaning systems and fluids.

According to various embodiments, fuel injector cleaning system 100 includes an injector cleaner assembly 102, a fluid delivery assembly 104, a waste assembly 106, and a controller 108.

Injector cleaner assembly 102 includes an injector cleaning housing 110, a heater 112, a temperature sensor 113, and an injector driver 114. The injector cleaning housing 110 defines a cavity 116 configured to receive a fuel injector 118. In some embodiments, the structure of the cavity 116 is similar to the structure of a cylinder head to which the fuel injector 118 is intended to be attached for operation. In some embodiments, the fuel injector 118 is a diesel fuel injector. However, in other embodiments, the fuel injector 118 is configured to inject any of a variety of types of fuels, such as natural gas, propane, ethanol, gasoline, and the like.

In some embodiments, the fuel injector cleaning system 100 includes a plurality of injector cleaner assemblies 102. In such an embodiment, the fuel injector cleaning system 100 is capable of cleaning multiple fuel injectors 118 simultaneously.

The heater 112 is operatively coupled to the injector cleaning housing 110 to controllably heat the injector cleaning housing 110 to heat the fluid therein, including the fluid in and around the fuel injector 118. The heater is positioned on the injector cleaning housing so as to be proximate to the nozzle of the fuel injector 118 to be positioned in the injector cleaning housing 110.

The temperature sensor 113 is operably coupled to the injector cleaning housing 110 and is operably and communicatively coupled to the controller 108. The temperature sensor 113 is configured to measure a temperature indicative of a temperature of the fluid in the injector cleaning housing 110 and to transmit a signal indicative of the measured temperature value to the controller 108. In some embodiments, the temperature sensor 113 is a thermocouple. In other embodiments, the temperature sensor 113 is a thermistor or another type of temperature sensor. In some embodiments, the temperature sensor 113 extends through the injector cleaning housing 110 and directly measures the fluid temperature. However, in other embodiments, the temperature sensor 113 is configured to measure the temperature of the injector cleaning housing 110. In such embodiments, the temperature of the fluid in the injector cleaning housing 110 is inferred based on the temperature of the injector cleaning housing 110.

The injector driver 114 is configured to be operably coupled to a fuel injector 118. The injector driver 114 controllably actuates the fuel injector 118 during the cleaning process. More specifically, the injector driver 114 sends electrical control signals to the fuel injector 118 to actuate a solenoid of the fuel injector 118 to cause movement of a valve plunger of the fuel injector 118. This results in a precisely controlled amount of fuel being dispensed from the nozzle of the fuel injector 118 when operating on an engine. In some embodiments, the injector driver 114 used with the fuel injector cleaning system 100 is a table style designed specifically for bench testing the fuel injectors 118. In other embodiments, the injector driver 114 is integrated in an electronic control module ("ECM"), which may be included in the controller 108 or separate from the controller 108.

The fluid delivery assembly 104 includes a three-way valve 120, a calibration fluid reservoir 122, a cleaning fluid reservoir 124, a first supply line 126, a second supply line 128, an input line 130, a first pump 132, a second pump 134, and a pressure sensor 136.

The three-way valve 120 is configured to controllably allow at least one of the cleaning fluid and the calibration fluid to flow to the fuel injector 118. The three-way valve 120 includes a first inlet 138, a second inlet 140, and an outlet 142. The first supply line 126 fluidly couples the calibration fluid reservoir 122 and a first inlet 138 of the three-way valve 120 to provide a fluid flow of calibration fluid therebetween. The second supply line 128 fluidly couples the cleaning fluid reservoir 124 and a second inlet 140 of the three-way valve 120 to provide a fluid flow of cleaning fluid therebetween. The input line 130 extends between a first end 144 and a second end 146. The first end 144 is fluidly coupled to the outlet 142 of the three-way valve 120. In some embodiments, the second end 146 is configured to be fluidly coupled to a fuel inlet 148 of the fuel injector 118 in the injector cleaning housing 110. Thus, in operation, the input line 130 fluidly couples the outlet 142 of the three-way valve 120 with the fuel inlet 148 of the fuel injector 118 to provide a fluid flow of at least one of the calibration fluid and the cleaning fluid flowing therebetween. In other embodiments, the second end 146 is configured to be fluidly coupled to the injector cleaning housing 110. Thus, in operation, input line 130 fluidly couples outlet 142 of three-way valve 120 and injector cleaning housing 110 to provide a fluid flow of at least one of calibration fluid and cleaning fluid flowing therebetween. In some embodiments, each of the first and

second supply lines

126, 128 and the input line 130 is formed of stainless steel tubing. In other embodiments, at least one of the first and

second supply lines

126, 128 and the input line 130 is formed from other types of metal or polymer tubes.

The three-way valve 120 is controllable between a first position, a second position, and intermediate positions therebetween. When the three-way valve 120 is in the first position, the three-way valve 120 allows the calibration fluid to flow from the calibration fluid reservoir 122 to the fuel inlet 148 of the fuel injector 118. When the three-way valve 120 is in the second position, the three-way valve 120 allows the cleaning fluid to flow from the cleaning fluid reservoir 124 to the fuel inlet 148 of the fuel injector 118. The intermediate position of the three-way valve 120 allows a respective relative amount of each of the calibration fluid and the cleaning fluid to be communicated to the fuel inlet 148 of the fuel injector 118.

As described in further detail below, in some embodiments, the three-way valve 120 is an electrically controlled valve such that the valve position is controlled in response to a control signal received from the controller 108. In other embodiments, the three-way valve 120 is mechanically controlled such that the valve position is changed by a human operator. In other embodiments, the three-way valve 120 allows each of the calibration fluid and the cleaning fluid to flow therethrough, and the flow of each fluid is controlled by operation of each of the first pump 132 and the second pump 134.

The first pump 132 is operatively coupled to the first supply line 126 to pressurize the calibration fluid flowing through the first supply line 126. The first pump 132 may be any of various types of pumps. For example, in some embodiments, the first pump 132 is a motor-driven commercial pump. In some embodiments, the first pump 132 is a hydraulic manual pump. In some embodiments, the first pump 132 is a pneumatic hydraulic pump. In operation, according to various embodiments, the first pump 132 is configured to pressurize the calibration fluid in the first supply line 126 to about 3000 psi. In some embodiments, the first pump 132 is configured to pressurize the calibration fluid in the first supply line 126 to at least about 2000 psi. Other embodiments utilize other types of fluids in place of the calibration fluid. For example, according to various embodiments, the fuel injector cleaning system 100 utilizes any fluid having anti-corrosion properties instead of a calibration fluid.

The second pump 134 is operably coupled to the second supply line 128 to pressurize the cleaning fluid flowing through the second supply line 128. The second pump 134 may be any of various types of pumps. For example, in some embodiments, the second pump 134 is a motor-driven commercial pump. In some embodiments, second pump 134 is a reciprocating fluid pump. In one embodiment, the second pump 134 is an electric pressure washer. For example, in one embodiment, the second pump 134 is an electric pressure washer configured to pressurize fluid at pressures up to 1650psi with flow rates of up to 1.25 gallons per minute. In other embodiments, the second pump 134 is a different type of fluid pump.

A pressure sensor 136 is operatively coupled to the input line 130 for measuring a pressure of a fluid (e.g., at least one of a calibration fluid and a cleaning fluid) flowing therethrough. In some embodiments, pressure sensor 136 comprises an analog pressure gauge. In other embodiments, the pressure sensor 136 is configured to transmit (e.g., to the controller 108) an electronic signal indicative of the measured pressure. Although not shown in fig. 1, it should be understood that in various embodiments, the fuel injector cleaning system 100 includes various other sensors, such as, for example, pressure sensors, temperature sensors, and the like. For example, in some embodiments, the injector cleaner system includes a second pressure sensor operably coupled to the first supply line 126, and a third pressure sensor operably coupled to the second supply line 128 to respectively measure the pressure of the fluid flowing therethrough.

The waste assembly 106 includes a waste reservoir 150 fluidly coupled to the injector cleaning housing 110 by a waste line 152. A waste line 152 provides fluid communication of the calibration fluid and the cleaning fluid from the injector cleaning housing 110 to the waste reservoir 150. The cleaning fluid is transferred to the waste reservoir 150 after being applied to the fuel injector 118 during the cleaning process. Similarly, after flushing the fuel injector 118 after applying the cleaning fluid to the fuel injector 118, the calibration fluid is transferred to the waste reservoir 150. Thus, the cleaning fluid and the calibration fluid delivered to the waste reservoir 150 may include particulate matter removed from the fuel injector 118. In some embodiments, the waste assembly includes two waste reservoirs 150, one for each of the cleaning fluid and the calibration fluid. In such embodiments, at least one of the cleaning fluid and the calibration fluid may be collected, filtered, and reused from the respective waste reservoir 150.

Controller 108 is operatively and communicatively coupled to at least one of heater 112, temperature sensor 113, injector driver 114, fuel injector 118, three-way valve 120, first and second pumps 132, 134, and pressure sensor 136. In some embodiments, the controller 108 is also operably and communicatively coupled to other sensors and components not shown in fig. 1. As described further below in conjunction with FIG. 2, the controller 108 is configured to control operation of the fuel injector cleaning system 100 through various cleaning cycles. More specifically, the controller 108 is configured to operate the heater 112 and the three-way valve 120, and actuate the fuel injector 118 via the injector driver 114 in accordance with the cleaning process parameters. In some embodiments, the controller 108 is configured to determine various operating conditions (e.g., temperature, pressure, etc.) of the injector cleaning system, and to control operation of the fuel injector cleaning system 100 based on the determined conditions.

For example, in one embodiment, the cleaning cycle includes a first phase and a second phase. In the first stage, the controller 108 is configured to actuate the three-way valve 120 to flow cleaning fluid from the cleaning fluid reservoir 124 to the fuel injector 118. The controller 108 is also configured to operate the heater 112 to heat the cleaning fluid flowing through the fuel injector 118. In a second phase, which follows the first phase, the controller 108 is configured to actuate the three-way valve 120 such that the calibration fluid flows from the calibration fluid reservoir 122 to the fuel injector 118. An exemplary injector cleaning process is described further in connection with FIG. 3.

FIG. 2 is a block diagram of the controller 108 of the fuel injector cleaning system 100 of FIG. 1. The controller 108 includes a processor 202 and a memory 204. The memory 204 is shown as including an operating condition circuit 206, a fluid delivery circuit 208, a seat integrity circuit (seat integrity circuit)210, an injector actuation circuit 212, and a heater circuit 214 communicatively coupled to one another. Generally, the controller 108 is configured to control operation of at least one of the heater 112, the injector driver 114, and the three-way valve 120 to perform an injector cleaning cycle. Although various circuits with specific functions are shown in fig. 2, it should be understood that controller 108 may include any number of circuits for performing the functions described herein. For example, the activities of multiple circuits may be combined into a single circuit, additional circuits with additional functionality may be included, and so on. Further, it should be understood that the controller 108 may further control other cleaning systems and/or engine activities beyond the scope of the present disclosure.

Certain operations of the controller 108 described herein include operations to interpret and/or determine one or more parameters. As used herein, interpreting or determining includes receiving a value by any method known in the art, including at least receiving a value from a data link or network communication, receiving an electronic signal (e.g., a voltage, frequency, current, or PWM signal) characterizing the value, receiving a computer-generated parameter characterizing the value, reading the value from a memory location on a non-transitory computer-readable storage medium, receiving the value as a runtime parameter by any means known in the art, receiving a value by which the interpreted parameter can be computed, and/or receiving the value by reference to a default value interpreted as a parameter value.

The operating condition circuit 206 is in operable communication with various sensors 216. For example, sensors 216 may include temperature sensor 113, pressure sensor 136, other temperature and pressure sensors, and other types of sensors. The operating condition circuit 206 is configured to receive the measurement values from the sensor 216 and interpret the measurement values based on the received measurement values. Thus, the measurements may include, but are not limited to, temperature values, pressure values, or other types of system measurements.

The fluid delivery circuit 208 is configured to control operation of the three-way valve 120 to control at least one of the flow of the calibration fluid and the cleaning fluid to the fuel injector 118. For example, in one embodiment, the fluid delivery circuit 208 is configured to transmit a first control signal to the three-way valve 120 during a first phase of the cleaning cycle to move the three-way valve 120 to a second position to flow cleaning fluid from the cleaning fluid reservoir 124 to the fuel inlet 148 of the fuel injector 118. After completion of the first phase, the fluid delivery circuit 208 is configured to transmit a second control signal to the three-way valve 120 during a second phase of the cleaning cycle to move the three-way valve 120 to the first position to flow the calibration fluid from the calibration fluid reservoir 122 to the fuel inlet 148 of the fuel injector 118. In some embodiments, the fluid delivery circuit 208 is further configured to control the operation of at least one of the first pump 132 and the second pump 134.

The seat integrity circuit 210 is configured to test the integrity of the seats of the fuel injector 118 during a first or pre-cleaning phase of the cleaning cycle. The purpose of the seat is to seal the fuel injector 118 to the cylinder head of the engine. Damage to the seat (loss of integrity of the seat) may result in leakage of pressurized air and fluid between the fuel injector 118 and the cylinder head. The seat integrity circuit 210 is configured to test seat integrity by pressurizing the fuel injector 118 and monitoring pressure loss over a period of time to detect the presence of a leak. In some embodiments, the fuel injector 118 is pressurized by actuating a plunger of the fuel injector 118 to a closed position, actuating the three-way valve 120 to a second position to allow the cleaning fluid to flow to the fuel injector 118, and operating the second pump 134 to pressurize the cleaning fluid to a predetermined test pressure. In some embodiments, second pump 134 is stopped and/or three-way valve 120 is actuated to a closed position and the pressure in input line 130 is measured over time via pressure sensor 136. Pressure loss over time may indicate poor seat integrity. In some cases, the seat may be cleaned to remove particulate deposits, and the seat integrity may be retested. However, in other embodiments, the seat may be permanently damaged.

The injector actuation circuit 212 is configured to actuate the fuel injector 118 during a cleaning cycle. In some embodiments, the injector actuation circuit 212 is configured to transmit a control signal to the injector driver 114, and the injector driver 114 controls actuation of the fuel injector 118 based on the received control signal. More specifically, the injector driver 114 varies the current provided to the fuel injector 118, which triggers a solenoid in the fuel injector 118, thereby moving the valve plunger. Actuating the fuel injector 118 during the cleaning process removes more particulate deposits from the fuel injector 118 in a shorter time than applying cleaning fluid through the fuel injector 118 when the valve plunger is in a single static position.

The heater circuit 214 is configured to operate the heater 112 to heat the injector cleaning housing 110 to heat the fuel flowing through the fuel injector 118. In some embodiments, heater circuit 214 monitors the temperature of temperature sensor 113 via a temperature value received from operating condition circuit 206 and provides a voltage to heater 112 to maintain heater 112 at a predetermined temperature throughout at least a portion of the cleaning process. For example, in some embodiments, the heater circuit 214 is configured to maintain the heater 112 at 120 degrees fahrenheit during the first stage of the cleaning process. In some embodiments, heater circuit 214 is configured to maintain heater 112 at a particular temperature over a plurality of cleaning cycles. However, in other embodiments, the heater circuit 214 is configured to maintain the heater at a particular temperature for only a portion of the cleaning process (e.g., the first stage).

FIG. 3 is a flowchart illustrating a method 300 of cleaning a fuel injector, according to an exemplary embodiment. In some embodiments, the method 300 is performed by the fuel injector cleaning system 100 of fig. 1 using a sulfamic acid-based fuel injector cleaning fluid. However, in other embodiments, the method 300 is similarly performed using other systems and devices.

At 302, a fuel injector (e.g., fuel injector 118) is connected to the fuel injector cleaning system 100. In some embodiments, the fuel injector 118 is connected to the fuel injector cleaning system 100 by inserting the fuel injector 118 into the injector cleaning housing 110 and connecting the injector driver 114 to the fuel injector 118. In some embodiments, the input line 130 is connected to a fuel inlet 148 of the fuel injector 118, and the waste line 152 is connected to a fuel return of the fuel injector 118. In other embodiments, at least one of the input line 130 and the waste line 152 is fluidly coupled to the injector cleaning housing 110 rather than directly coupled to the fuel injector 118.

At 304, the fuel injector 118 is pressurized to test the integrity of its seat. As described above in connection with FIG. 2, seat integrity is tested by pressurizing the fuel injector 118 and monitoring the pressure loss over a period of time to detect the presence of a leak. If the pressure loss is greater than the leakage threshold amount, the seat is potentially damaged. In this case, the cleaning process is ended and the fuel injector 118 is removed to determine whether the seat can be cleaned or repaired.

At 306, the solenoid of the fuel injector 118 is actuated by the injector driver 114 to confirm proper operation of the fuel injector. If the injector plunger moves as expected in response to a control signal received from the injector driver 114, the solenoid operates normally. If the solenoid is determined to be malfunctioning, the solenoid is potentially damaged. However, in some cases, a detected incorrect solenoid operation may indicate a very high particle accumulation. For example, the nozzle needle may be stuck in the nozzle of the fuel injector 118. According to various embodiments, if the solenoid is found to be operating improperly, the cleaning process may continue or end. For example, in some embodiments, the cleaning process continues while continuing to attempt to actuate the solenoid to attempt to allow the cleaning fluid to remove enough particulate buildup to allow proper operation of the fuel injector 118.

At 308, the cleaning fluid is applied to the fuel injector 118. By controlling the three-way valve 120 to the second position, the cleaning fluid is circulated through the fuel injector 118 as described above in connection with FIG. 2. In some embodiments, a cleaning fluid is applied to the fuel injector 118 at 304 to perform a seat integrity test. In this case, the cleaning fluid continues to be applied to the fuel injector at 308. It should be understood that in some embodiments, 304 and 306 are omitted, such that the injector is cleaned without assessing seat integrity and solenoid operation.

At 310, the cleaning fluid is pressurized. In some embodiments, the cleaning fluid is pressurized by operating the second pump 134. In some embodiments, the cleaning fluid is pressurized to 1000 psi. However, in other embodiments, the cleaning fluid is pressurized to 1650 psi.

At 312, the cleaning fluid is heated. The cleaning fluid is heated by operating the heater 112. In some embodiments, the cleaning fluid is heated to 200 ° F.

At 314, the fuel injector 118 is actuated. In some embodiments, the fuel injector 118 is continuously actuated to cause the solenoid to repeatedly open and close the nozzle.

Although 310-314 are shown in parallel in fig. 3, in some embodiments, any of 310-314 may be performed in series in any order. For example, in some embodiments, 310 and/or 312 are performed to pressurize and/or heat the cleaning fluid for a predetermined amount of time before continuing 314 to actuate the fuel injector 118. For example, the cleaning fluid is applied to the fuel injector 118 and heated and/or pressurized for a first period of time to provide a heat/pressure "soak". Upon completion of the first period, the fuel injector 118 is actuated for a second period. According to various embodiments, the fuel injector 118 may or may not be heated and/or pressurized during the second period of time.

At 316, the fuel injector 118 is flushed with the calibration fluid. The fuel injector 118 is flushed with the calibration fluid by controlling the three-way valve 120 to the first position, as described above in connection with fig. 2. Flushing the fuel injector 118 with the calibration fluid removes any residual cleaning fluid from the fuel injector 118 to prevent potential corrosion. In some embodiments, the fuel injector 118 is flushed for a predetermined amount of time.

The schematic flow chart diagrams and method diagrams described above are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps or processes are indicative of representative embodiments. Other steps, process sequences and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. In addition, reference throughout this specification to "one embodiment", "an example embodiment", or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment", "in an exemplary embodiment", and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

Additionally, the format and symbols employed are provided to explain the logical steps of the illustrative figures and are understood not to limit the scope of the methods illustrated by the figures. Although various arrow types and line types may be employed in the exemplary diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and program code.

Many of the functional units described in this specification have been labeled as circuits, in order to more particularly emphasize their implementation independence. For example, a circuit may be implemented as a hardware circuit comprising custom Very Large Scale Integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors (e.g., logic chips, crystals), or other discrete devices. The circuitry may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

As described above, the circuitry may also be implemented in a machine-readable medium for execution by various types of processors (such as the processor 202 of FIG. 2). For example, executable code may be identified as one or more physical or logical blocks of computer instructions which may, for example, be organized as an object, procedure, or function. Nevertheless, the executables of an identified circuit need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the circuit and achieve the stated purpose for the circuit. Indeed, the circuitry of the computer-readable program code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within circuits, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network.

The computer readable medium (also referred to herein as machine-readable medium or machine-readable content) may be a tangible computer readable storage medium storing computer readable program code. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. As mentioned above, examples of a computer-readable storage medium may include, but are not limited to, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), a Digital Versatile Disc (DVD), an optical storage device, a magnetic storage device, a holographic storage medium, a micromechanical storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, and/or store computer readable program code for use by and/or in connection with an instruction execution system, apparatus, or device.

Computer readable program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages.

The program code may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the schematic flowchart and/or schematic block diagram block or blocks.

Accordingly, the present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A method of cleaning a fuel injector, the method comprising:

applying a cleaning fluid based on sulfamic acid to a fuel injector;

pressurizing the cleaning fluid to a predetermined pressure;

heating the cleaning fluid to a predetermined temperature; and

flushing the fuel injector with a calibration fluid.

2. The method of claim 1, wherein the cleaning fluid applied to the fuel injector is simultaneously pressurized and heated.

3. The method of claim 1, further comprising actuating the fuel injector when the cleaning fluid is applied to the fuel injector.

4. The method of claim 1, further comprising draining the cleaning fluid from the fuel injector prior to flushing the fuel injector with the calibration fluid.

5. The method of claim 1, further comprising, prior to applying the cleaning fluid:

pressurizing the fuel injector; and

monitoring pressure loss over time to estimate a seat integrity of the fuel injector.

6. The method according to any one of claims 1-5, further comprising:

wherein applying the cleaning fluid to the fuel injector comprises actuating a three-way valve to cause the cleaning fluid to flow from a cleaning fluid reservoir to the fuel injector;

wherein flushing the fuel injector with the calibration fluid comprises actuating the three-way valve to stop the flow of the cleaning fluid and flow the calibration fluid from a calibration fluid reservoir to the fuel injector.

7. A fuel injector cleaning fluid comprising a mixture of water, ethanol and sulfamic acid, wherein the mixture comprises water in the range of 78 to 82% by weight, ethanol in the range of 14 to 18% by weight and sulfamic acid in the range of 1 to 3% by weight.

8. The fuel injector cleaning fluid of claim 7, wherein the sulfamic acid is 2.05 percent by weight of the mixture.

9. The fuel injector cleaning fluid of claim 7, wherein the water is 81.80% by weight of the mixture.

10. The fuel injector cleaning fluid of claim 7, wherein the ethanol is 16.15% of the mixture by weight.

11. The fuel injector cleaning fluid of claim 7, wherein the sulfamic acid is 2.05% by weight of the mixture, wherein the water is 81.80% by weight of the mixture, and wherein the ethanol is 16.15% by weight of the mixture.