JP2005104392A - Tank fuel purifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tank fuel purifier, easily and quickly eliminating foreign matter in fuel, and made in a compact manner. <P>SOLUTION: A construction machine 1 is provided with the tank fuel purifier 10, whereby the fuel in the fuel tank 2 can be circulated, and filtered by a filter 1 to be automatically purified. Therefore, it is not necessary to once empty the fuel storing tank installed in a job site and eliminate foreign matter staying in the interior of the tank. Further, since purification is automated, the cleanliness of fuel can be easily improved in a short time without trouble. Furthermore, the purifier 10 is composed of a particle counter 15, an oil feed pump 14, a filter 12 and a differential pressure sensor 16, which are components not requiring large space, whereby the purifier 10 can be made enough compact and surely installed without any increase in size of the construction machine 1 itself. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an in-tank fuel cleaning processing apparatus (hereinafter sometimes abbreviated as a processing apparatus).

Conventionally, fuel to construction machines operating at construction sites is transported from the fuel supplier to the site using a tank lorry, etc., and then temporarily stored in a fuel storage tank provided at the site. Supplied to the fuel tank of construction machinery. In such a fuel storage tank, it is desirable to accurately remove rust and the like generated inside, and various removal devices and removal agents have been developed.
In addition, large tanks such as tankers are provided with large tanks that form part of the hull, but there is a high possibility that rust will be generated in the tank or foreign objects will be mixed in during long voyages. It is common to mount a clean processing apparatus (for example, Patent Document 1).

JP-A-8-310490

By the way, most construction machines operate in a field environment where a large amount of dust or dirt is generated. Therefore, a large amount of foreign matter such as dust and dirt may be mixed in the fuel storage tank installed at such a site. Also, rust in fuel tanks that have been used for many years may be mixed as foreign matter. On the construction machine side to which the fuel containing foreign matter is supplied, the foreign matter may cause abnormal wear on the parts constituting the fuel injection device of the engine, resulting in functional failure.
Specifically, obstacles occur in the needle, command piston, two-way valve, etc. that constitute the sliding portion of the fuel injection device. Particularly in the fuel injection device used in the common rail injection system, each sliding component is more Such a problem is likely to occur because of the precise design.

Therefore, it is conceivable to remove the foreign matter in the storage tank using the above-described removal device, but in an environment where the foreign matter is likely to be mixed frequently, the removal work is troublesome and troublesome, There are many problems in implementation, such as the need to temporarily empty the fuel storage tank, during which fuel cannot be supplied or replenished.
In addition, a large-scale cleaning apparatus used for a ship cannot be easily installed at a construction site or the like, and cannot be mounted on the construction machine side.

  An object of the present invention is to provide an in-tank fuel cleaning apparatus that can easily and quickly remove foreign matters in fuel and can be made compact.

An in-tank fuel cleaning apparatus according to claim 1 of the present invention includes an oil feeding circuit that sends out the fuel from a tank that stores fuel, a filter provided on the oil feeding destination side of the oil feeding circuit, and the filter. A return circuit for returning the discharged fuel to the tank, an oil feed pump and a particle counter provided in the oil feed circuit, and a control means for controlling the oil feed pump based on a signal from the particle counter, This control means keeps the in-tank fuel cleaning processing device in operation when the cleanliness based on the signal from the particle counter exceeds a predetermined value, and if not, exceeds the predetermined value. The processing apparatus is stopped.
However, “stopping the tank fuel cleaning processing device” means that the tank does not function as a fuel cleaning processing device. For this purpose, for example, at least the oil pump should be stopped. It does not matter whether the power source is turned off or kept on.

An in-tank fuel cleaning processing apparatus according to claim 2 of the present invention is the in-tank fuel cleaning processing apparatus according to claim 1, wherein the control means has a cleanliness based on a signal from the particle counter exceeding a predetermined value. In the case where the absence state continues for a plurality of times or for a predetermined time, the fuel purifying apparatus in the tank is stopped.
Here, as the particle counter, a type in which detection signals corresponding to cleanliness are periodically output at a predetermined interval can be adopted. In this case, “continues multiple times” means that a signal that does not exceed a predetermined value. The term “continuous for a predetermined time” means that the signal that does not exceed a predetermined value is output continuously.

According to a third aspect of the present invention, there is provided an in-tank fuel purification processing apparatus according to the first or second aspect, wherein the spill fuel surplus in the fuel injection device is returned to the tank. The circuit is provided with another particle counter, and the control device operates the in-tank fuel cleaning processing device when the cleanliness based on a signal from the another particle counter exceeds a predetermined value. To do.
However, “activate the in-tank fuel cleaning processing device” means that, contrary to the case of claim 1, it means that the in-tank fuel cleaning processing device functions, and the cleanliness exceeds a predetermined value. It is not the case that the entire tank fuel cleaning apparatus is in operation. That is, of course, the other particle counter needs to be always on while the engine or the like is operating even when the oil feed pump or the particle counter on the oil feed circuit side is stopped. .

  A tank fuel cleaning treatment apparatus according to claim 4 of the present invention is the tank fuel cleaning processing apparatus according to any one of claims 1 to 3, wherein the tank fuel cleaning processing apparatus is provided across the oil feeding circuit and the return circuit. A differential pressure sensor for detecting a differential pressure before and after the filter, and an alarm means for notifying the clogged state when the filter is determined to be clogged based on a signal from the differential pressure sensor. It is characterized by being.

  The tank fuel cleaning apparatus according to claim 5 of the present invention is the tank fuel cleaning apparatus according to any one of claims 1 to 4, wherein the tank fuel cleaning apparatus is in operation. The display means is provided.

  A tank fuel cleaning apparatus according to claim 6 of the present invention is the tank fuel cleaning apparatus according to any one of claims 1 to 5, wherein the tanks communicate with each other on the bottom side. It is composed of two container parts, the oil supply source side of the oil supply circuit is connected to the first container part, and the return destination side of the return circuit is connected to the second container part. A supply circuit for supplying fuel from a tank is connected.

  A tank fuel cleaning apparatus according to claim 7 of the present invention is the tank fuel cleaning apparatus according to any one of claims 1 to 6, wherein the tank fuel cleaning apparatus is any one of a construction machine, an industrial machine, and an industrial vehicle. It is mounted.

According to the tank fuel cleaning apparatus of the first aspect, the amount of foreign matter such as sand existing in the fuel tank is detected by the particle counter provided in the oil feeding circuit, and the amount of foreign matter is predetermined by the control means. The in-tank fuel cleaning apparatus is driven until the value falls below the value, and the fuel is circulated and filtered through a filter to automatically clean.
Therefore, it is not necessary to empty the tank once to remove the foreign matter accumulated in the tank, and since it is automatically cleaned, the cleanliness of the fuel can be improved easily and in a short time without trouble. Moreover, since it is composed of small-part parts such as a particle counter, an oil feed pump, and a filter, it is sufficiently compact and can be installed on the fuel storage tank side, for example, at a construction site. It can also be provided on the fuel tank side.

  According to the in-tank fuel cleaning processing apparatus of the second aspect, since the in-tank fuel cleaning processing apparatus is stopped after confirming that the cleanness is good a plurality of times or for a predetermined time, the fuel cleanliness is ensured. Therefore, the reliability of the processing apparatus is improved.

If the fuel purifier in the tank is installed in the fuel tank on the construction machine side, once the fuel in the fuel tank has been cleaned, even if foreign matter enters the fuel tank for any reason, It is also possible that the pump and main particle counter do not operate and are not cleaned. In such a case, fuel whose cleanliness is not improved is sent to the fuel injection device.
On the other hand, according to the in-tank fuel cleaning processing device of claim 3, the clean state of the fuel sent to the fuel injection device can be easily obtained by detecting the amount of foreign matter in the spill fuel with another particle counter. Therefore, even when the fuel whose cleanliness is not improved is sent, the re-cleaning can be performed promptly and the wear of the components constituting the fuel injection device can be reliably prevented.
In addition, the fuel purifier in the tank is operated manually by an operator or a fuel manager predicting dirt in the tank, and automatically operating at predetermined time intervals by predicting when the tank is dirty. However, the in-tank fuel purifying apparatus according to the third aspect of the invention can be operated after detecting that the fuel is really contaminated by another particle counter, and wasteful operation can be suppressed.

  According to the in-tank fuel cleaning processing apparatus of the fourth aspect, since the differential pressure sensor is provided between the oil feeding circuit and the return circuit, the degree of clogging of the filter is determined by comparing the actual differential pressure with a preset differential pressure. Is surely determined, and the replacement time of the filter can be easily understood.

  According to the tank fuel cleaning processing apparatus of the fifth aspect, since the display means for indicating that the present processing apparatus is in operation is provided, the operation status can be seen at a glance. For this reason, if such a display means is provided in the cab of a construction machine or the like, the operation status of the processing apparatus can be easily confirmed while performing the work on the construction machine. It can be recognized at any time that the spent fuel is being sent. In addition, if there is no indication that the system has been operating for a long time, it is possible to suspect a failure of the processing device itself, so that a failure of the processing device can be detected early, and a large amount of dirty fuel is lost during the failure. It can be prevented from being sent to an injection device or the like, and abnormal wear of parts can be prevented.

  According to the in-tank fuel cleaning treatment device of claim 6, after the low cleanliness fuel is sent out from the first container portion, the cleanliness is increased by passing through the filter and returned to the second container portion. The second container portion is supplied to the engine or the like. Therefore, even when both the engine and the processing device are operated at the same time, for example, when the processing device is mounted not on the fuel storage tank side but on the construction machine side, the fuel with improved cleanliness that has always passed through the filter This is advantageous in that abnormal wear of parts is more reliably prevented.

On the other hand, the site where construction machines work is frequently changed. For this reason, it is necessary for the operator of the construction machine to care about the cleanliness of the fuel in the fuel storage tank installed at each site, which is a burden on the operator.
On the other hand, according to the in-tank fuel cleaning processing apparatus of claim 7, since this processing apparatus is provided on the construction machine side, even if the site is changed and fuel is supplied from a different fuel storage tank, The cleanliness of the fuel can be improved by the processing device, and it is not necessary to care about the cleanliness of the fuel in the fuel storage tank, thereby reducing the burden on the operator.
The construction machine is, for example, a hydraulic excavator, a wheel loader, a bulldozer, a motor grader, and the industrial machine is, for example, an engine-driven stationary generator, a stationary crusher, a stationary soil conditioner, Industrial vehicles are dump trucks, self-propelled crushers, and self-propelled soil improvement machines. Among them, the present invention is particularly preferably used for those that are disposed in a bad environment with a lot of dust and dirt.

[First Embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram illustrating a configuration of a main part of a construction machine 1 such as a hydraulic excavator, a wheel loader, a bulldozer, and a motor grader to which the in-tank fuel cleaning apparatus 10 according to the present embodiment is applied.

First, the construction machine 1 has a configuration in which fuel stored in a fuel tank 2 is supplied to a fuel injection device 4 through a supply circuit 3 and injected into a cylinder of an engine (not shown), as in general specifications. The supply circuit 3 is provided with an extension filter 5, a fuel pump 6, and a common rail 7 from the upstream side. The fuel pump 6 includes a pressure feed pump 61 that draws fuel from the fuel tank 2, a standard filter 62 that cleans the fuel discharged from the pressure feed pump 61, and a high-pressure pump 63 that supplies the fuel discharged from the standard filter 62 to the common rail 7. And. Reference numeral 8 in the drawing is a drain circuit that returns the spill fuel surplus in the fuel injection device 4 to the fuel tank 2.
Fuel is supplied to the fuel tank 2 of the construction machine 1 as necessary from a fuel storage tank (not shown) installed at the construction site.

  Here, the standard filter 62 is a filter that is used as a standard for the construction machine 1 regardless of the situation at the construction site. The performance of the standard filter 62 in this embodiment is 6 mg / L of cleanliness (6 mg of foreign matter is contained in 1 L). Can be improved to a cleanness of 0.5 mg / L (that is, the fuel supplied to the engine must have a cleanliness of at least 0.5 mg / L or less).

  The extension filter 5 is a filter that is added when there is more dust and dirt than a normal site, and foreign substances are easily mixed in the fuel storage tank installed at the site. In the embodiment, it is possible to improve the fuel containing 25 mg / L of foreign matter to a cleanliness of 6 mg / L or less. Such an additional filter 5 may be integrally attached with a water separation filter for separating water mixed in the fuel.

  In the present embodiment, it is assumed that the construction machine 1 operates in a further adverse environment, that is, a larger amount of foreign matter exceeding 25 mg / L may be mixed in the fuel storage tank. The construction machine 1 is provided with an in-tank fuel cleaning apparatus 10 that effectively cleans the fuel in the fuel tank 2. That is, the in-tank fuel cleaning processing device 10 does not clean the fuel in the fuel storage tank installed at the site on the fuel storage tank side, but at the time when it is transferred from here to the fuel tank 2 of the construction machine 1. It is a device that cleans fuel. Hereinafter, the processing apparatus 10 will be described in detail.

  In FIG. 2, the in-tank fuel cleaning processing apparatus 10 includes the fuel tank 2, and an oil feeding circuit 11 for sending fuel from the fuel tank 2, and an oil feeding destination side of the oil feeding circuit 11. A plurality of (four in this embodiment) filters 12 provided in parallel and a return circuit 13 for returning the fuel discharged from these filters 12 to the fuel tank 2 are provided. The oil feed circuit 11 is provided with an oil feed pump 14 that draws fuel from the fuel tank 2, and a particle counter 15 is provided upstream of the oil feed pump 14. A differential pressure sensor 16 is provided across the oil feed pump 14 downstream of the oil feed circuit 11 and the return circuit 13. Further, another particle counter 21 is provided in the drain circuit 8.

  The detection signals from the particle counters 15 and 21 and the detection signal from the differential pressure sensor 16 are input to a controller (control means) 17. On the other hand, a drive control signal from the controller 17 is output to the oil feed pump 14. The controller 17 is electrically connected with a display means 18 such as a liquid crystal monitor and an alarm means 19 including a buzzer, a sound generator, a warning light, and the like. The display means 18 and the alarm means 19 are provided in the cab of the construction machine 1 so that the display contents can be confirmed and the alarm contents can be recognized at any time during the operation of the construction machine 1 by the operator. Yes.

  In such a configuration, when four filters 12 are used (shown as a filter group in FIG. 1), the fuel 170L having a cleanliness of 100 mg / L is circulated at a flow rate of 28 L / min. Has the ability to improve to a cleanness of 25 mg / L in about 20 minutes. However, the performance of the filter 12 is not limited to this, and it is required to improve the cleanliness of the fuel when it is supplied to the fuel tank 2, the capacity of the fuel tank 2 (about 500L in this embodiment), and the cleanliness. It may be decided in consideration of the time to be played. The number of filters 12 is also the same.

  The oil feed pump 14 is driven by a hydraulic motor provided in the construction machine 1, or driven by an electric motor using a battery as a power source (electric power is supplied from the battery via a converter in the controller). The drive mechanism is arbitrary, such as one driven by engine output transmitted through a power transmission device. In either case, the construction machine 1 can be driven by a drive control signal from the controller 17 while the engine is operating (in the case of an electric motor, the engine can be stopped).

  Each of the particle counters 15 and 21 is configured to be able to numerically measure the cleanliness of the supplied fuel and the cleanliness of the spill fuel from the fuel injection device 4 by optical means or the like, and a detection signal corresponding to the measured value Is constantly output to the controller 17. The power supply of the particle counters 15 and 21 may be a battery, and power is supplied from the battery via the controller.

  The differential pressure sensor 16 detects the difference between the pressure of the fuel flowing in the oil feeding circuit 11 and the pressure of the fuel returning in the return circuit 13, and outputs a detection signal corresponding to the pressure difference to the controller 17. As a result, when the pressure difference is equal to or smaller than the predetermined value, the filter 12 functions normally, and when the pressure difference exceeds the predetermined value, the filter 12 is clogged. Such a power source for the differential pressure sensor 16 may also be a battery, and power is also supplied from the battery via the controller.

  The controller 17 is configured by using computer technology, and includes a cleanliness comparison means 21, a differential pressure comparison means 22, a signal generation means 23, each of which is a computer program, and a storage means (not shown) constituted by various elements. I have.

  The cleanliness comparison means 21 has a function of comparing the preset cleanliness C with the actual cleanliness Cact. Of the fuel obtained based on the detection signal from the particle counter 15. The cleanliness C set in advance is the cleanliness of the fuel that can be delivered from the fuel tank 2 to the extension filter 5, and is 25 mg / L in this embodiment. According to the cleanliness comparison means 21, when the actual cleanness Cact. Exceeds the cleanliness C, it is determined that the fuel is dirty. On the contrary, if the actual cleanliness level Cact. Is equal to or lower than the cleanliness level C, it is determined that the foreign matter in the fuel has been sufficiently removed.

  The differential pressure comparison means 22 has a function of comparing a preset differential pressure ΔP with a differential pressure ΔPact. Obtained based on a detection signal from the differential pressure sensor 16. The preset differential pressure ΔP is a value that defines the use limit of the filter 12 and is a value that prevents the foreign substance removal function from being maintained when the filter 12 is further clogged. According to this differential pressure comparison means 22, if the actual differential pressure ΔPact. Between the pressure in the oil feed circuit 11 and the pressure in the return circuit 13 is equal to or less than the differential pressure ΔP, the filter 12 is clogged so much. Therefore, it is determined that the filter 12 sufficiently maintains the foreign substance removing function. Conversely, if the actual differential pressure ΔPact. Exceeds the differential pressure ΔP, it is determined that the filter 12 is clogged and that the filter 12 needs to be replaced.

  The signal generation unit 23 generates a drive control signal for the oil feed pump 14 based on the determination result of the cleanliness comparison unit 21. Specifically, if the cleanliness comparison means 21 determines that the cleanness Cact. Exceeds the cleanliness C, the drive control signal is continuously generated and output so as to maintain the drive of the oil feed pump 14. When the cleanliness Cact. Is equal to or less than the cleanliness C, a drive control signal for stopping the oil feed pump 14 is generated and output. Further, while the oil feed pump 14 is being driven, a signal to the display means 18 is generated and output, and information indicating that it is being cleaned is displayed on the display means 18. Further, according to the signal generation means 23, an output signal to the alarm means 19 is generated based on the determination result of the differential pressure comparison means 22. That is, when it is determined that the differential pressure ΔPact. Exceeds the differential pressure ΔP, an output signal to the alarm unit 19 is generated and output, and the alarm unit 19 is activated to prompt the operator to replace the filter 12.

By the way, as shown in FIG. 2, the fuel tank 2 used in the present embodiment is divided into a first container part 2A and a second container part 2B, and the bottom sides of the first and second container parts 2A and 2B. They communicate with each other via the communication part 2C.
The first container part 2A has a larger capacity than the second container part 2B. The bottom part of the first container part 2A is connected to the oil supply source side of the oil supply circuit 11, and oil supply (replenishment) is also performed on the first container part 2A. On the other hand, the supply source side of the supply circuit 3 is connected to the inclined bottom portion of the second container portion 2B, and the return destination sides of the return circuit 13 and the drain circuit 8 are connected to the second container portion 2B.

  According to this structure, the low cleanliness fuel replenished from the fuel storage tank is first stored in both the first and second container portions 2A and 2B through the communication portion 2C. 11, after passing through the filter 12 of the processing apparatus 10, the cleanliness is improved and returns to the second container part 2 </ b> B through the return circuit 13. At this time, when the driving source of the processing device 10 (oil feed pump 14) is an engine and the engine is operating in parallel with the processing device 10, a part of the fuel returning to the second easy portion 2B is obtained. It is sent to the supply circuit 3.

  In the present embodiment, the flow rate of the fuel returning from the return circuit 13 is set to be larger than the flow rate sent to the supply circuit 3 even when the engine speed is increased to the maximum. The dirty fuel on the part 2A side is difficult to move to the second container part 2B side through the communication part 2C. Further, due to such a difference in flow rate, there is fuel that is returned from the supply circuit 3 while returning to the second container portion 2B. This amount of fuel moves to the first container portion 2A side through the communication portion 2C, mixes with the fuel originally present in the first easy portion 2A, and recirculates. Then, after the predetermined time has elapsed, the cleanliness of the entire fuel in the fuel tank 2 is sufficiently improved, and the oil feed pump 14 is stopped.

Below, operation | movement of the fuel clean processing apparatus 10 in a tank is demonstrated based on the flowchart shown in FIG.
Step (hereinafter, step is abbreviated as “S”) 1: When the engine of the construction machine 1 is started, first, the signal generation means 23 of the controller 17 is automatically activated to generate and output a control signal to send the oil pump 14 is driven. At this time, the particle counters 15 and 21 and the differential pressure sensor 16 are also turned on. Further, the signal generating unit 23 causes the display unit 18 to display information indicating that the fuel is being cleaned.

  S2: Next, the differential pressure comparison means 22 is activated, and the actual differential pressure ΔPact. Between the oil feeding circuit 11 and the return circuit 13 is compared with a preset differential pressure ΔP to check whether the filter 12 is clogged. Judging. If the differential pressure ΔPact. Is greater than the differential pressure ΔP and it is determined that the filter 12 is clogged, the process proceeds to S3. If it is determined that the differential pressure ΔPact. Is smaller than the differential pressure ΔP and the clogging has not progressed much, the process proceeds to S4.

  S3: If the clogging exceeds the limit, the signal generation means 23 outputs a signal to the alarm means 19 and activates it to prompt the operator to replace the filter 12.

  S4: Here, the cleanliness comparison means 21 is activated, and the cleanliness Cact. Of the circulating fuel is compared with a preset cleanliness C. If it is determined that the cleanliness Cact. Is greater than the cleanliness C and the amount of foreign matter mixed per unit volume is greater than the specified value, the process returns to S2, and the fuel circulation is continued to improve the cleanliness. Plan. On the other hand, when the cleanliness of the fuel in the fuel tank 2 was originally good or when the cleanliness was improved by the circulation of the fuel, it was determined that the cleanliness Cact. Was smaller than the cleanliness C. If yes, go to S5.

  S5: When it is determined in S4 that the cleanliness of the fuel in the fuel tank 2 has been improved, the controller 17 confirms whether or not the good cleanliness state has continued for a predetermined time, and determines whether or not it has been improved reliably. To do. That is, S4 to S5 are repeated until the internal timer expires, and it is confirmed over a predetermined time that the cleanness Cact. Is smaller than the cleanness C. Thereafter, the process proceeds to S6.

  S6: When it is determined in S5 that the cleanliness of the fuel has been improved, the signal generator 23 outputs a drive control signal to the oil pump 14 and stops the oil pump 14. Thereby, the particle counter 15 and the differential pressure sensor 16 are also turned off.

  S7: On the other hand, after the fuel in the fuel tank 2 is cleaned, the detection of foreign matter in the spill fuel is started by another particle counter 21, and the cleanliness of the spill fuel is adjusted while the engine is running. Monitor. Here, when the actual cleanliness level Cact. Exceeds the cleanliness level C, it is determined that foreign matter has entered the fuel tank 2 for some reason and the cleanliness level has deteriorated, and the process returns to S1 and is sent again. The oil pump 14 and the like are operated.

As described above, when the fuel stored in the fuel tank 2 is dirty, the cleanliness thereof is automatically improved by the processing device 10, and even if the fuel is supplied to the engine side, the fuel injection device 4 may cause abnormal wear. Disappears.
Note that when the fuel tank 2 is replenished with dirty fuel from the fuel storage tank installed on site, the engine of the construction machine 1 is usually temporarily stopped at the time of replenishment. If the work after refueling is started, the above process is repeated in the same manner, and the cleanliness is improved.

According to this embodiment, there are the following effects.
(1) That is, the construction machine 1 is provided with an in-tank fuel cleaning processing device 10, which is installed on-site in order to circulate the fuel in the fuel tank 2 through the filter 12 and automatically clean it. There is no need to empty the fuel storage tank once and remove the foreign matter accumulated inside. Further, since the fuel is automatically cleaned, the cleanliness of the fuel can be improved easily and in a short time without trouble. Moreover, since the processing apparatus 10 is composed of parts with a small space, such as the particle counter 15, the oil feed pump 14, the filter 12, and the differential pressure sensor 16, the processing apparatus 10 can be made sufficiently compact, and the construction machine 1 itself Can be installed securely without increasing the size.

(2) Further, as shown in S5 of FIG. 3, the controller 17 stops the oil feed pump 14 after confirming that the cleanliness is good for a predetermined time, so that the cleanliness of the fuel is reliably improved. It can be recognized that the processing has been performed, and the reliability of the processing apparatus 10 can be improved.

(3) Further, after the cleanliness in the fuel tank 2 is improved, the amount of foreign matter in the spill fuel is detected by another particle counter 21, so that the fuel sent to the fuel injection device 4 is cleaned. The state can also be easily determined. Therefore, after once improving the cleanliness of the fuel in the fuel tank 2, for example, the construction machine 1 is operated for a long time with the cap of the fuel filler being removed, and a large amount of foreign matter is mixed in the fuel tank 2 during that time. Even when the cleanliness of the fuel is deteriorated, the cleaning can be performed again quickly based on the detection signal from the particle counter 21, and the wear of the components constituting the fuel injection device 4 can be reliably prevented.
In addition, by providing another particle counter 21, it is possible to operate the in-tank fuel cleaning processing apparatus 10 after the particle counter 21 detects that the fuel is really contaminated. Control can be simplified, for example, it is not necessary to drive the oil feed pump 14 in conjunction with the start.

(4) Since the differential pressure sensor 16 is provided between the oil feeding circuit 11 and the return circuit 13 in the processing apparatus 10, the degree of clogging of the filter 12 is reliably determined by comparing the differential pressure ΔPact. With the differential pressure P. Thus, the replacement time of the filter 12 can be easily recognized.

(5) According to the processing apparatus 10, since the display means 18 indicating that the fuel is being cleaned is provided in the cab, it is easy to operate the processing apparatus 10 while performing the work on the construction machine 1. It can be confirmed at any time that fuel with improved cleanliness is being sent. In addition, when there is no indication that the system has been operating for a long time, it is possible to suspect a failure of the processing apparatus 10 itself, so that the failure of the processing apparatus 10 can be detected early, and a large amount of dirty fuel is in the process of failure. Therefore, it is possible to prevent abnormal wear of parts in advance.

(6) Since the fuel tank 2 is divided into the first and second container portions 2A and 2B, even when both the engine and the processing device 10 are operated simultaneously, the cleanliness is always improved more than when the filter 12 is passed. The supplied fuel can be supplied to the engine, and abnormal wear of parts can be prevented more reliably.

(7) Since the processing apparatus 10 is provided on the construction machine 1 side instead of the on-site fuel storage tank side, even if the site is changed and fuel is supplied from a different fuel storage tank, its own processing apparatus 10, the cleanliness of the fuel can be improved, and it is not necessary to care about the cleanliness of the fuel in the fuel storage tank, so that the burden on the operator can be greatly reduced.

[Second Embodiment]
FIG. 4 shows the main configuration of the in-tank fuel cleaning apparatus 10 according to the second embodiment of the present invention.
In the first embodiment, the fuel tank 2 is divided into the first and second container portions 2A and 2B. However, in this embodiment, the sub tank 30 is provided on the lower side of the normal fuel tank 2, and this A supply circuit 3 is connected to the sub tank 30.
In addition, when the fuel supply circuit 11 connected to the fuel tank 2 is provided with a switching valve 31, and the switching operation is performed by a switching signal from the controller 17, the fuel flows to the particle counter 15 (FIG. 2) side. And the case of flowing to the sub tank 30 side. Note that the flow of fuel from the fuel tank 2 to the sub tank 30 is not due to a pump or the like, but due to a natural fall at the head pressure. Other configurations are substantially the same as those of the first embodiment.

  The sub tank 30 has a capacity smaller than that of the fuel tank 2 and includes a float 32 having a limit switch function. From the float 32, different signals are output to the controller 17 when the fuel is at the upper limit level (state shown) and when the fuel is at the lower limit level (shown by a two-dot chain line in the figure). In the sub tank 30, the fuel capacity at the lower limit level is determined in consideration of the time required to clean all the fuel (full tank state) in the main fuel tank 2, and the engine is within this time. It is set to the extent that it does not spend completely even if it is fully operated.

  In this embodiment, when the volume level of the fuel in the sub tank 30 reaches the lower limit, the fuel in the fuel tank 2 is cleaned over a predetermined time. From the fuel flows to the particle counter 15 side. When the cleaning is completed, the switching valve is switched, and the fuel in the fuel tank 2 with improved cleanness is sent to the sub tank 30 and stored up to the upper limit level. For this reason, the fuel is not sent to the sub tank 30 until the cleanliness of the fuel in the fuel tank 2 is improved after the fuel in the sub tank 30 reaches the lower limit level. The capacity at the lower limit level described above is set so as not to use up all the fuel.

Below, operation | movement of the fuel cleaning processing apparatus 10 in a tank in this embodiment is demonstrated based on the flowchart shown in FIG.
S1: When the engine of the construction machine 1 is started, first, the controller 17 outputs a switching signal to the switching valve 31 so that the fuel in the fuel tank 2 flows to the particle counter 15. If it has already been switched at the time of engine start, the state is maintained as it is.

  S2: Next, the controller 17 monitors the signal input from the float 32, and detects whether the fuel amount in the sub tank 30 has reached the lower limit. That is, the engine is driven with fuel until the lower limit is reached.

S3: When the fuel amount reaches the lower limit in S2, the signal generation means 23 (FIG. 2) of the controller 17 is activated, generates and outputs a control signal, and drives the oil feed pump 14 (FIG. 2). At this time, similarly to the first embodiment, the particle counter 15 and the differential pressure sensor 16 are also turned on. Further, the signal generating unit 23 causes the display unit 18 to display information indicating that the fuel is being cleaned.
The following S4 to S8 are the same as S2 to S6 (FIG. 3) in the first embodiment.

S9: When cleaning of the fuel in the fuel tank 2 is completed in S8 and the oil feed pump 14 is stopped, the switching valve 31 is switched thereafter, and the fuel with improved cleanliness is transferred to the sub tank 30.
S10: The fuel is stored in the sub tank 30 until the fuel reaches the upper limit. That is, when the upper limit side signal is input from the float 32 to the controller 17, the process returns to S1 and the switching valve 31 is switched again to the particle counter 15 side to stop the storage in the sub tank 30.

According to the present embodiment, by having the same configuration as that of the first embodiment, the effects (1), (2), and (4) to (7) described above can be obtained similarly. In addition, there are the following effects.
(8) That is, in this embodiment, the sub tank 30 completely separated from the fuel tank 2 of Menin is provided, and after the cleanliness of the fuel in the fuel tank 2 is completely improved, the fuel is supplied to the sub tank 30. Therefore, high quality fuel with improved cleanliness can always be supplied from the sub tank 30 to the engine side, and abnormal wear of the fuel injection device 4 (FIG. 1) can be more reliably prevented.

(9) Further, since the fuel tank 2 that is normally mounted on the construction machine 1 can be used as it is, the sub-tank 30 and other components are utilized using the clearance space in the hood of the construction machine 1. Can be easily retrofitted to the existing construction machine 1, and the cost for mounting the processing device 10 can be reduced.

In addition, this invention is not limited to the said embodiment, Including other structures etc. which can achieve the objective of this invention, the deformation | transformation etc. which are shown below are also contained in this invention.
For example, in each of the embodiments described above, the in-tank fuel cleaning apparatus 10 is provided in the construction machine 1, but is not limited thereto, and may be provided on the fuel storage tank side installed at the construction site.

In the first embodiment, the fuel tank 2 is divided into first and second container portions 2A and 2B communicating with each other, and higher quality fuel is supplied to the engine side. In the second embodiment, By providing the sub tank 30 different from the fuel tank 2, only the fuel whose cleanliness is completely improved is supplied to the engine side. However, only the fuel tank 2 as in the second embodiment is used. Even when the processing apparatus 10 is configured, it is included in the present invention.
However, in such a case, while the engine is stopped, for example, the oil pump 14 is driven by battery power or external commercial power so that dirty fuel is not supplied to the engine. It is desirable to improve the fuel cleanliness in the fuel tank 2 in advance before starting the engine so that the processing apparatus 10 can be operated.

In the first embodiment, the particle counter 21 is provided in the drain circuit 8. However, a similar configuration may be applied to the second embodiment, which further reduces wear and the like in the fuel injection device 4. Can be prevented.
Of course, the particle counter 21 in the drain circuit 8 is not essential to the present invention, and may be provided as necessary.

  In the first and second embodiments, when the engine is started, for example, the controller 17 is automatically started in conjunction with the start key switch, and the oil feed pump 14 and the like are operated. A switch different from the switch may be provided, and by operating this switch, the processing device 10 may be started at any timing to clean the fuel regardless of the operation of the engine.

The best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described with particular reference to certain specific embodiments, but without departing from the spirit and scope of the invention, Various modifications can be made by those skilled in the art in terms of quantity and other detailed configurations.
Therefore, the description limited to the shape, quantity and the like disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

  The present invention can be applied not only to an on-site fuel storage tank or a construction machine, but also to an industrial machine or an industrial vehicle, and can be particularly suitably used in an environment in which a large amount of foreign matter is likely to be mixed in the fuel.

The schematic diagram which shows the principal part structure of the construction machine with which the in-tank fuel cleaning processing apparatus which concerns on 1st Embodiment of this invention was applied. The schematic diagram which shows the structure of the fuel clean processing apparatus in a tank of 1st Embodiment. The flowchart which shows operation | movement of the fuel cleaning processing apparatus in a tank of 1st Embodiment. The schematic diagram which shows the principal part structure of the fuel clean processing apparatus in a tank which concerns on 2nd Embodiment of this invention. The flowchart which shows operation | movement of the fuel cleaning processing apparatus in a tank of 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Construction machine, 2 ... Tank, 2A ... 1st container part, 2B ... 2nd container part, 4 ... Fuel injection apparatus, 8 ... Drain circuit, 10 ... Fuel-cleaning processing apparatus in tank, 11 ... Oil supply circuit, 12 DESCRIPTION OF SYMBOLS ... Filter, 13 ... Return circuit, 14 ... Oil pump, 15 ... Particle counter, 16 ... Differential pressure sensor, 17 ... Controller (control means), 18 ... Display means, 21 ... Another particle counter.

Claims (7)

In the tank fuel purifier,
An oil supply circuit (11) for sending out the fuel from a tank (2) for storing fuel;
A filter (12) provided on the oil feeding destination side of the oil feeding circuit (11);
A return circuit (13) for returning the fuel discharged from the filter to the tank (2);
An oil feed pump (14) and a particle counter (15) provided in the oil feed circuit (11);
Control means (17) for controlling the oil feed pump (14) based on a signal from the particle counter (15),
When the cleanliness based on the signal from the particle counter (15) exceeds a predetermined value, the control means (17) keeps the in-tank fuel cleaning processing device (10) in operation and exceeds the predetermined value. If not, the in-tank fuel cleaning treatment device (10) is stopped. In the tank fuel cleaning treatment device (10) according to claim 1,
When the state in which the cleanness based on the signal from the particle counter (15) does not exceed a predetermined value continues for a plurality of times or for a predetermined time, the control means (17) In-tank fuel cleaning treatment device (10), The in-tank fuel cleaning treatment device (10) according to claim 1 or 2,
In the drain circuit (8) for returning the spill fuel surplus in the fuel injection device (4) to the tank (2), another particle counter (21) is provided,
The control device (17) operates the in-tank fuel cleaning processing device (10) when the cleanliness based on a signal from the another particle counter (21) exceeds a predetermined value. Inner fuel cleaning processing device (10). In the tank fuel cleaning treatment device (10) according to any one of claims 1 to 3,
A differential pressure sensor (16) provided between the oil feeding circuit (11) and the return circuit (13) to detect a differential pressure before and after the filter (12);
An in-tank fuel cleaning processing device comprising alarm means (19) for notifying the clogging state when it is determined that the filter is clogged based on a signal from the differential pressure sensor (10). The in-tank fuel cleaning treatment device (10) according to any one of claims 1 to 4,
An in-tank fuel cleaning treatment device (10), comprising display means (18) for displaying that the in-tank fuel cleaning processing device (10) is in operation. In the tank fuel cleaning treatment device (10) according to any one of claims 1 to 5,
The tank (2) is composed of first and second container parts (2A, 2B) that communicate with each other at the bottom,
The oil feeding source side of the oil feeding circuit (11) is connected to the first container part (2A),
The return destination side of the return circuit (13) is connected to the second container part (2B),
A fuel supply circuit (3) for supplying fuel from the tank (2) is connected to the second container part (2B). An in-tank fuel cleaning treatment device (10). The in-tank fuel cleaning treatment device (10) according to any one of claims 1 to 6,
An in-tank fuel cleaning treatment device (10), which is mounted on any one of a construction machine (1), an industrial machine, and an industrial vehicle.

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