JP7129391B2 - construction machinery - Google Patents

Description

The present invention relates to a construction machine using biodiesel fuel as engine fuel.

In recent years, construction machines such as hydraulic excavators and wheel loaders also widely use biodiesel fuel produced from raw materials such as rapeseed oil and palm oil as the fuel supplied to their engines. This biodiesel fuel is more prone to oxidative deterioration over time than light oil. When oxidatively degraded biodiesel fuel is used, sludge is formed in the fuel due to heat, leading to engine failure such as sticking of engine piston rings and clogging of filters. Therefore, it is required to predict whether the biodiesel fuel in the fuel tank is oxidatively deteriorated.

For example, in Patent Document 1, a relationship between the rate of oxidation deterioration of fuel and the temperature of fuel, and the relationship between the degree of oxidation deterioration of fuel, the rate of oxidation deterioration of fuel, and the measurement time for each temperature of fuel is stored in advance. By correlating these relationships with the temperature of the fuel in the fuel tank detected by the temperature sensor and the time required to detect the temperature of the fuel measured by the timer and performing complex calculations, A fuel deterioration prediction device for predicting the degree of oxidation deterioration of fuel in a fuel tank has been disclosed.

Japanese Patent No. 5876730

Oxidative deterioration of the fuel in the fuel tank may occur over a long period of time, especially when the construction machinery is stored for a long period of time after operation, or when the construction machinery is not used for a long period of time after being shipped from the factory until it actually starts operating. It is a problem if the construction machine does not operate due to

When the construction machine does not operate for a long period of time, the temperature of the fuel in the fuel tank changes in various ways during that time. The method of predicting the degree of oxidation degradation of fuel by performing complicated calculations is not suitable. In addition, since complicated calculations are performed when determining the degree of oxidation deterioration of fuel, the configuration of the device becomes complicated and expensive, so construction machinery equipped with a fuel deterioration prediction device is not widespread. It is the reality.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a construction machine capable of easily determining whether or not the fuel in the fuel tank is oxidatively deteriorated.

In order to achieve the above objects, the present invention provides an engine, a tank body for storing fuel to be supplied to the engine, a supply port for supplying fuel into the tank body, and an openable/closable fuel supply port. and a deterioration determination device for determining whether or not the fuel in the tank body is oxidatively deteriorated, wherein the fuel tank has a cap attached to the supply port. An open/close sensor for detecting opening/closing and outputting an open signal or a closed signal to the deterioration determination device is mounted inside the tank body, and a liquid level sensor for detecting the position of the liquid level of the fuel in the tank body. is provided, and when the deterioration determination device acquires the closing signal from the opening/closing sensor, the closing time that is the time when the cap is closed is recorded , and after recording the closing time, the opening/closing sensor and the value detected by the liquid level sensor when the open signal is obtained is greater than the previous detection value, fuel is not supplied into the tank body. resetting the recorded closing time, calculating the elapsed time since the cap was closed based on the reset closing time and the current time, and calculating the calculated elapsed time is equal to or longer than a preset time until the fuel is oxidatively deteriorated, it is determined that the fuel in the tank body is oxidatively deteriorated.

According to the present invention, it is possible to easily determine whether or not the fuel in the fuel tank is oxidatively deteriorated. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a side view showing the appearance of a hydraulic excavator according to each embodiment of the present invention; FIG. It is a figure which shows the electrical connection relationship of a deterioration determination apparatus. 3 is a functional block diagram showing functions of the deterioration determination device according to the first embodiment; FIG. 4 is a flow chart showing the flow of processing executed by the deterioration determination device according to the first embodiment; FIG. 5 is a functional block diagram showing functions possessed by a deterioration determination device according to a second embodiment; 9 is a flow chart showing the flow of processing executed by the deterioration determination device according to the second embodiment;

A crawler hydraulic excavator will be described below as one aspect of the construction machine according to each embodiment of the present invention.

<Configuration of hydraulic excavator 1>
First, the configuration of the hydraulic excavator 1 will be described with reference to FIGS. 1 and 2. FIG.

FIG. 1 is a side view showing the appearance of a hydraulic excavator 1 according to each embodiment of the present invention. FIG. 2 is a diagram showing an electrical connection relationship of the deterioration determination device 7. As shown in FIG.

The hydraulic excavator 1 includes a traveling body 2, a revolving body 3 provided above the traveling body 2 so as to be able to revolve via a revolving device 30, and a front working device attached in front of the revolving body 3 for performing excavation work and the like. 4 and .

The traveling body 2 has a crawler 21 and a traveling motor 22 for rotationally driving the crawler 21, and the driving force of the traveling motor 22 rotates the crawler 21 in contact with the ground to move the vehicle body. move. In this embodiment, the traveling body 2 is of a crawler type, but is not limited to this, and may be of a wheel type. Both the crawler 21 and the traveling motor 22 are arranged on both the left and right sides of the traveling body 2, but FIG. 1 shows only the crawler 21 and traveling motor 22 on one side.

The revolving structure 3 includes a revolving frame 31, an operator's cab 32, a counterweight 33 for maintaining a balance with the front working device 4 so that the vehicle body does not tilt, and an engine compartment containing an engine 341. 34 and a tank chamber 35 in which the fuel tank 5 is accommodated.

In the revolving frame 31, the operator's cab 32 is in the front part, the counterweight 33 is in the rear part, the engine compartment 34 is between the operator's cab 32 and the counterweight 33, and the tank compartment 35 is in front of the engine compartment 34 and is in the operator's compartment. 32, respectively. In the hydraulic excavator 1, the front working device 4 is arranged in the central portion in the left-right direction. placed on each side.

The front working device 4 includes a boom 41 rotatably attached to a revolving frame 31 at its base end, an arm 42 rotatably attached to the tip of the boom 41 , and a rotatable tip of the arm 42 . a releasably attached bucket 43;

The front work device 4 also includes a boom cylinder 41A that connects the swing frame 31 and the boom 41, an arm cylinder 42A that connects the boom 41 and the arm 42, and a bucket cylinder 43A that connects the arm 42 and the bucket 43. , and a plurality of pipes (not shown) for guiding hydraulic oil to each of these cylinders 41A, 42A, 43A.

The boom cylinder 41A rotates (elevates) the boom 41 in the vertical direction with respect to the revolving body 3 by extending and retracting the rod, and the arm cylinder 42A moves the arm 42 in the longitudinal direction with respect to the boom 41 by extending and retracting the rod. The bucket cylinder 43A rotates the bucket 43 in the front-rear direction with respect to the arm 42 by extending and contracting the rod.

The bucket 43 scoops up a load such as earth and sand and unloads it at a predetermined position. This bucket 43 can be changed to an attachment such as a grapple for gripping wood, rocks, waste, etc., or a breaker for excavating rock. As a result, the hydraulic excavator 1 can perform various types of work including excavation, crushing, and the like using attachments suitable for the type of work.

As shown in FIG. 2, the fuel tank 5 accommodated in the tank chamber 35 of the revolving body 3 includes a tank body 51 for storing fuel to be supplied to the engine 341 and a supply tank for supplying fuel to the tank body 51 . It has a port 52 and a cap 53 capable of opening and closing the supply port 52 .

A float sensor 61 is provided in the tank body 51 as a liquid level sensor for detecting the position L of the liquid level of the stored fuel. An opening/closing sensor 62 is attached to the cap 53 to detect opening/closing of the cap 53 with respect to the supply port 52 . The opening/closing sensor 62 does not necessarily have to be attached to the cap 53, and may be attached to another position in the fuel tank 5 as long as it is possible to detect the opening/closing of the cap 53.

The hydraulic excavator 1 uses biodiesel fuel as the fuel for the engine 341 . Biodiesel fuel is more likely to be oxidized and deteriorated over time than light oil. A deterioration determination device 7 is mounted to determine whether or not there is a deterioration.

Further, the hydraulic excavator 1 serves as a notification device for notifying that the fuel in the tank body 51 is oxidatively deteriorated when the deterioration determination device 7 determines that the fuel in the tank body 51 is oxidatively deteriorated. A monitor 321 is provided in the operator's cab 32 .

The deterioration determination device 7 is configured by connecting a CPU, RAM, ROM, HDD, input I/F, and output I/F to each other via a bus. A float sensor 61, an open/close sensor 62, and a key switch 322 as an engine starting device for starting the engine 341 are connected to the input I/F, and a monitor 321 and a starter 342 for starting the engine 341 are connected to the output I/F. It is connected to the. Hereinafter, the functional configuration of the deterioration determination device 7 will be described for each embodiment.

<First embodiment>
The functional configuration and processing contents of the deterioration determination device 7 according to the first embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG.

(Functional configuration of deterioration determination device 7)
First, the functional configuration of the deterioration determination device 7 will be described with reference to FIG.

FIG. 3 is a functional block diagram showing functions of the deterioration determination device 7 according to the first embodiment.

In the hardware configuration described above, the deterioration determination device 7 reads out a determination program (software) stored in a recording medium such as a ROM, HDD, or optical disc by the CPU, expands it on the RAM, and executes the expanded determination program. By doing so, the determination program and the hardware cooperate to realize the function of the deterioration determination device 7 .

In the present embodiment, the deterioration determination device 7 is described as a computer configured by a combination of software and hardware. An integrated circuit that implements the functions of the determination program executed on the side may also be used.

The deterioration determination device 7 includes a data acquisition unit 70, a time recording unit 71, a time storage unit 72, a fuel supply determination unit 73, a reset unit 74, an engine state determination unit 75, a clock unit 76, and an elapsed time. It includes a calculation unit 77 , an oxidation deterioration determination unit 78 , a threshold storage unit 78A, and a command signal output unit 79 .

The data acquisition unit 70 receives the cap 53 open signal or closed signal output from the open/close sensor 62, the ON signal output from the key switch 322, and the detection value detected by the float sensor 61 (the amount of fuel in the tank main body 51). Data on the position of the liquid surface) L are acquired respectively. In the following description, the signal for opening the cap 53 is simply referred to as the "cap open signal", and the signal for closing the cap 53 is simply referred to as the "cap close signal".

When the data acquisition unit 70 acquires the cap closing signal, the time recording unit 71 records the closing time, which is the time when the cap 53 is closed with respect to the supply port 52 . The recorded closing time is stored in the time storage unit 72 .

The fuel supply determination unit 73 determines whether or not fuel has been supplied into the tank body 51 based on the detection value L of the float sensor 61 acquired by the data acquisition unit 70 . Specifically, when the detection value L detected by the float sensor 61 is greater than the previous detection value Lp (L>Lp), the fuel supply determination unit 73 determines that the fuel is not supplied to the tank body 51. I judge that. On the other hand, when the detection value L detected by the float sensor 61 is equal to or less than the previous detection value Lp (L≤Lp), the fuel supply determination unit 73 determines that fuel is not supplied to the tank body 51. do.

After the time recording unit 71 records the closing time, the data acquisition unit 70 acquires the cap open signal from the opening/closing sensor 62, and the fuel supply determination unit 73 determines whether fuel is supplied into the tank main body 51. If so, the closing time stored in the time storage unit 72 is reset.

Based on the ON signal from the key switch 322 acquired by the data acquisition unit 70, the engine state determination unit 75 determines that the engine 341 is ready to be started. On the other hand, when the data acquisition unit 70 does not acquire the ON signal from the key switch 322, the engine state determination unit 75 determines that the engine 341 is not ready to be started, that is, the engine 341 remains stopped. do.

The clock unit 76 acquires the current time. The elapsed time calculation unit 77 determines whether the cap 53 is attached to the supply port 52 based on the closing time recorded by the time recording unit 71 and stored in the time storage unit 72 and the current time acquired by the clock unit 76 . Elapsed time Te after closing (hereinafter simply referred to as "elapsed time Te") is calculated.

Based on the elapsed time Te calculated by the elapsed time calculator 77, the oxidation deterioration determination unit 78 determines whether or not the fuel in the tank body 51 is in a state of oxidation deterioration. Specifically, when the elapsed time Te is equal to or greater than a preset time Tth (hereinafter simply referred to as “set time Tth”) as the time until the fuel is oxidatively deteriorated (Te≧ Tth), it is determined that the fuel in the tank body 51 is oxidized and deteriorated. On the other hand, when the elapsed time Te is smaller than the set time Tth (Te<Tth), the oxidation deterioration determination unit 78 determines that the fuel in the tank body 51 is not oxidatively deteriorated. Note that the set time Tth is stored in the threshold storage unit 78A.

When the oxidation deterioration determination unit 78 determines that the fuel in the tank body 51 is in a state of oxidation deterioration, the command signal output unit 79 notifies the monitor 321 that the fuel in the tank body 51 is oxidation deterioration. Outputs a display command signal (a signal related to the notification command) to display that the In this case, command signal output unit 79 does not output a drive command signal to starter 342 . As a result, the deterioration determination device 7 controls the engine 341 to be locked when it determines that the fuel in the tank body 51 is in a state of oxidation deterioration.

(Processing in deterioration determination device 7)
Next, a specific flow of processing executed in the deterioration determination device 7 will be described with reference to FIG.

FIG. 4 is a flow chart showing the flow of processing executed by the deterioration determination device 7 according to the first embodiment.

First, when the data acquisition unit 70 acquires a cap closed signal from the opening/closing sensor 62 (step S701), the time recording unit 71 records the closing time (step S702). Subsequently, when the data acquisition unit 70 acquires the cap open signal from the open/close sensor 62 (step S703/YES), the fuel supply determination unit 73 determines that the detection value L of the float sensor 61 acquired by the data acquisition unit 70 is It is determined whether or not it is greater than the previous detection value Lp (step S704).

As described above, in this embodiment, it is possible to make an accurate determination by using the detection value detected by the float sensor 61 to determine whether or not the fuel has been supplied into the tank body 51 . It should be noted that a method other than the method using the float sensor 61 can be used to determine whether or not fuel has been supplied into the tank body 51, and another method will be described in the second embodiment.

If it is determined in step S704 that the detection value L of the float sensor 61 is greater than the previous detection value Lp (L>Lp) (step S704/YES), the fuel supply determination unit 73 determines that there is no fuel in the tank body 51. The supplied determination is made (step S705). Then, the reset unit 74 resets the closing time stored in the time storage unit 72 (step S706), and returns to step S701. This makes it possible to more accurately calculate the elapsed time Te that is used to determine the oxidation deterioration of the fuel in the tank body 51 .

On the other hand, when it is determined in step S704 that the detection value L of the float sensor 61 is equal to or less than the previous detection value Lp (L≤Lp) (step S704/NO), the fuel supply determination unit 73 It is determined that fuel is not supplied (step S707). When the data acquisition unit 70 acquires the cap closed signal from the open/close sensor 62 (step S708), the process returns to step S703.

Here, when it is determined that fuel is not supplied to the tank main body 51 even though the data acquisition unit 70 has acquired the cap open signal from the open/close sensor 62 in step S703 (step S703/YES) ( Step S707) is a case where an operator or worker opens the cap 53 and looks inside the tank body 51 for inspection or the like.

After the time recording unit 71 records the closing time in step S702, if the data acquisition unit 70 does not acquire the cap open signal from the open/close sensor 62 in step S703 (step S703/NO), that is, the cap 53 is closed. If it is still in the state, the engine state determination unit 75 determines whether or not the key switch 322 is turned on (step S709).

If it is determined in step S709 that the key switch 322 has been turned on (step S709/YES), the clock section 76 acquires the current time (step S710). Subsequently, the elapsed time calculator 77 calculates the elapsed time Te based on the closing time recorded in step S702 and the current time obtained in step S710 (step S711).

Next, the oxidation deterioration determination unit 78 determines whether or not the elapsed time Te calculated in step S711 is equal to or longer than the set time Tth (step S712). If it is determined in step S712 that the elapsed time Te is equal to or greater than the set time Tth (Te≧Tth) (step S712/YES), the oxidation deterioration determination unit 78 determines that the fuel in the tank body 51 is oxidatively deteriorated. Determine (step S713). On the other hand, if it is determined in step S712 that the elapsed time Te is smaller than the set time Tth (Te<Tth) (step S712/NO), the process returns to step S703.

When it is determined in step S713 that the fuel in the tank body 51 is oxidized and deteriorated, the command signal output unit 79 outputs a display command signal to the monitor 321, while outputting a drive command signal to the starter 342. is not output, the engine 341 is controlled to be locked (step S714), and the processing in the deterioration determination device 7 ends.

In this manner, when the deterioration determination device 7 determines that the fuel in the tank body 51 is oxidized and deteriorated, the monitor 321 displays the fact, thereby preventing the operator from starting the engine 341. It can be called attention. Furthermore, in the present embodiment, when it is determined that the fuel in the tank body 51 is oxidized and deteriorated, the deterioration determination device 7 controls the engine 341 to be in a locked state. It is possible to prevent such a situation.

As described above, in the hydraulic excavator 1, a simple method is adopted in which the open/close sensor 62 is attached to the cap 53 of the fuel tank 5 and the deterioration determination device 7 determines oxidation deterioration of the fuel in the fuel tank 5 from the open/close time of the cap 53. Since it is used, it is possible to suppress, at low cost, troubles and failures of the engine 341 that occur due to the use of oxidatively deteriorated fuel.

<Second embodiment>
Next, the functional configuration and processing contents of the deterioration determination device 8 according to the second embodiment of the present invention will be described with reference to FIGS. 5 and 6. FIG. In FIGS. 5 and 6, the same reference numerals are given to the components common to those described for the deterioration determination device 7 according to the first embodiment, and the description thereof will be omitted.

FIG. 5 is a functional block diagram showing functions of the deterioration determination device 8 according to the second embodiment. FIG. 6 is a flow chart showing the flow of processing executed by the deterioration determination device 8 according to the second embodiment.

The deterioration determining device 8 according to the present embodiment differs from the deterioration determining device 7 according to the first embodiment in the method of determining whether or not fuel has been supplied into the tank body 51 . As shown in FIG. 5 , the deterioration determination device 8 further includes an open time counting section 81 .

As shown in FIG. 6, after the closing time is recorded by the time recording unit 71 in step S702, when the data acquiring unit 70 acquires the cap open signal from the opening/closing sensor 62 (step S703/YES), the open time counting unit 80 counts the opening time To during which the cap 53 is opened with respect to the supply port 52 (step S801).

Subsequently, the fuel supply determining unit 82 determines that the opening time To, which started counting in step S801, is longer than the time Tm preset as the time required for inspection of the fuel tank 5 (hereinafter simply referred to as "inspection time Tm"). It is determined whether or not it is long (step S802).

If it is determined in step S802 that the opening time To is longer than the inspection time Tm (To>Tm) (step S802/YES), the fuel supply determination unit 82 determines that fuel has been supplied into the tank body 51 (step S705). On the other hand, when it is determined in step S802 that the open time To is equal to or less than the inspection time Tm (To≤Tm) (step S802/NO), the fuel supply determination unit 82 determines that fuel is not being supplied into the tank body 51. Determine (step S707).

In this way, it is also possible to determine whether or not fuel has been supplied into the tank body 51 based on the open time during which the cap 53 is open. This embodiment also provides the same actions and effects as those of the first embodiment.

The embodiments of the present invention have been described above. In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Further, part of the configuration of this embodiment can be replaced with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of this embodiment. Furthermore, it is possible to add, delete, or replace a part of the configuration of this embodiment with another configuration.

For example, the deterioration determination devices 7 and 8 may determine whether or not at least the fuel in the tank body 51 is in a state of oxidative deterioration. It suffices to perform the determination process based on the elapsed time Te from .

Further, in the above-described embodiment, the monitor 321 is described as one aspect of the notification device, but the notification device is not limited to this, and may be a notification device using sounds such as a buzzer.

Further, in the above embodiment, the hydraulic excavator 1 has been described as one aspect of construction machinery, but the present invention is not limited to this, and can be applied to other construction machinery such as wheel loaders and dump trucks. .

1: Hydraulic excavator (construction machinery)
5: fuel tanks 7, 8: deterioration determination device 51: tank body 52: supply port 53: cap 61: float sensor (liquid level sensor)
62: Open/close sensor 321: Monitor (notification device)
322: Key switch (engine starting device)
341: Engine

Claims (5)

engine and
a fuel tank having a tank body for storing fuel to be supplied to the engine, a supply port for supplying fuel into the tank body, and a cap capable of opening and closing the supply port;
a deterioration determination device that determines whether the fuel in the tank body is oxidatively deteriorated;
In a construction machine equipped with
In the fuel tank,
an opening/closing sensor is attached to detect opening/closing of the cap with respect to the supply port and output an open signal or a closed signal to the deterioration determination device;
Inside the tank body,
A liquid level sensor is provided for detecting the position of the liquid level of the fuel in the tank body,
The deterioration determination device is
When the closing signal from the opening/closing sensor is obtained, a closing time, which is the time when the cap is closed, is recorded;
After recording the closing time, the open signal is obtained from the open/close sensor, and the value detected by the liquid level sensor when the open signal is obtained is greater than the previous detection value. In this case, resetting the closing time recorded by judging that fuel has been supplied into the tank body,
calculating the elapsed time since the cap was closed based on the reset closing time and the current time;
If the calculated elapsed time is longer than or equal to a preset time required for the fuel to undergo oxidative deterioration, it is determined that the fuel in the tank body is in a state of oxidative deterioration. construction machinery. In the construction machine according to claim 1 ,
The deterioration determination device is
when the open signal is received from the opening/closing sensor after the closing time is recorded, the open time during which the cap is opened is counted;
Even if the counted opening time is longer than the time required for inspection of the fuel tank, it is determined that fuel has been supplied to the tank body, and the recorded closing time is reset. do
A construction machine characterized by: In the construction machine according to claim 1 ,
A notification device that notifies that the fuel in the tank body is oxidized and deteriorated,
The deterioration determination device is
A construction machine characterized by outputting a signal relating to a notification command to the notification device when it is determined that the fuel in the tank body is in a state of oxidative deterioration. In the construction machine according to claim 1 ,
An engine starting device for starting the engine,
The deterioration determination device is
A construction machine characterized in that it is determined whether or not the fuel in the tank body is oxidized and deteriorated when the engine starter is turned on. In the construction machine according to claim 4 ,
The deterioration determination device is
A construction machine characterized in that, when it is determined that the fuel in the tank body is in a state of oxidative deterioration, the engine is controlled to be in a locked state.

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