Construction machinery

Abstract

To provide construction machinery that can prevent substandard fuel from entering the fuel tank during refueling. [Solution] The hydraulic excavator 1, as a construction machine, has a fuel supply line A connected to a fuel tank 21, and includes a fuel supply device 30 that supplies fuel to the fuel tank 21 via this fuel supply line A, and a controller 39 that controls the fuel supply device 30. The fuel supply device 30 includes a fuel property sensor 36 that detects the properties of the fuel, and a fuel outlet on / off valve 38 provided in the fuel supply line A downstream of the fuel property sensor 36. If the properties of the fuel detected by the fuel property sensor 36 are poor, the controller 39 closes the fuel outlet on / off valve 38 to block the fuel supply line A and cut off the supply of fuel to the fuel tank 21.

Description

Technical Field

[0001] The present invention relates to a construction machine provided with a fuel supply device.

Background Art

[0002] Construction machines such as hydraulic excavators are equipped with an internal combustion engine as a prime mover, and a fuel tank that stores fuel to be supplied to the engine.

[0003] By the way, if inferior fuel is filled into the fuel tank, the inferior fuel being supplied to the engine may damage the engine and cause operation stop. In particular, when fuel management conditions are poor, there is a risk that a refueling worker may unintentionally fill the inferior fuel into the fuel tank. Patent Document 1 proposes an apparatus that determines the suitability of fuel by providing a sub-tank between the fuel tank and the engine, and mounting a sensor for detecting fuel properties on the sub-tank, and issues a warning when the fuel is inferior fuel.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] Meanwhile, in the case of the apparatus of Patent Document 1, if the refueled fuel is inferior fuel, the inferior fuel has already entered the path from the fuel tank to the sub-tank, so it is necessary to discharge the inferior fuel from both the fuel tank and the sub-tank once, and then refuel with normal fuel. As a result, the construction machine has to be stopped for a long time, which delays the work.

[0006] For this reason, in construction machines, it is desired to prevent inferior fuel from being introduced into the fuel tank during refueling.

[0007] This invention has been made in view of the above circumstances, and its objective is to provide a construction machine that can prevent substandard fuel from entering the fuel tank during refueling. [Means for solving the problem]

[0008] To achieve the above objective, the present invention provides a construction machine having a fuel tank, comprising a fuel supply device having a fuel supply pipeline connected to the fuel tank, supplying and storing fuel in the fuel tank via the fuel supply pipeline, and a controller for controlling the fuel supply device, wherein the fuel supply device includes a sensor for detecting the properties of the fuel and an on-off valve provided in the fuel supply pipeline downstream of the sensor in the direction of fuel flow supplied to the fuel tank, and the controller closes the on-off valve to block the fuel supply pipeline and shut off the supply of fuel to the fuel tank if the properties of the fuel detected by the sensor are poor, [Effects of the Invention]

[0009] According to the present invention, it is possible to provide construction machinery that can prevent substandard fuel from entering the fuel tank during refueling. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view showing a hydraulic excavator according to an embodiment. [Figure 2] This is a plan view of the upper rotating body as seen from above. [Figure 3] This is a perspective view showing the step section of the upper rotating body. [Figure 4] This is a perspective view showing the upper rotating body with the cover of the step section open. [Figure 5] This is a perspective view showing the fuel filter case. [Figure 6] This is a schematic diagram showing a longitudinal cross-section of the fuel filter case. [Figure 7]This is a block diagram that schematically shows the system configuration of the fuel supply system and peripheral equipment. [Figure 8] This is a flowchart illustrating the procedure for controlling fuel supply by the controller. [Modes for carrying out the invention]

[0011] A construction machine according to one embodiment of the present invention will be described below with reference to the drawings. Figure 1 is a side view showing a hydraulic excavator 1 as an example of construction machinery. In the following description, the front-rear, left-right (i.e., vehicle width), and up-down directions of the vehicle body 2 are defined primarily from the perspective of the operator seated in the cab 6 of the hydraulic excavator 1.

[0012] The body 2 of the hydraulic excavator 1 consists of a self-propelled crawler-type lower vehicle 3 and an upper slewing vehicle 4 that is rotatably mounted on top of the lower vehicle 3. A swing-type working device 5 for excavating earth and sand is attached to the front of the upper slewing vehicle 4. A cab 6 for the operator is located on the left side of the front of the upper slewing vehicle 4. The slewing frame 7 of the upper slewing vehicle 4 supports the engine and hydraulic pump, which will be described later, as well as a counterweight 8. The working device 5 is attached to the front of the slewing frame 7 and is configured to swing from side to side and to move up and down in the vertical direction as the upper slewing vehicle 4 rotates.

[0013] The working device 5 comprises, in order from the cab 6 side, a boom 9, an arm 10, and a bucket 11. The boom 9 is mounted to the slewing frame 7 so as to be able to move up and down by a boom cylinder 12. The arm 10 is mounted to the boom 9 so as to be able to rotate by an arm cylinder 13. The bucket 11 is mounted to the arm 10 so as to be able to rotate by a bucket cylinder 14. The boom cylinder 12, arm cylinder 13, and bucket cylinder 14 are hydraulic actuators.

[0014] FIG. 2 shows a top view of the upper revolving structure 4. In the upper revolving structure 4, a machine room 15 is formed on the rear side of the cab 6 and on the front side of the counterweight 8. An engine, a hydraulic pump, an exhaust system and the like are disposed in the machine room 15. A first engine cover 16 and a second engine cover 17 are disposed in the machine room 15 so as to be openable and closable. For example, the engine is positioned under the first engine cover 16, and the exhaust system and the hydraulic pump are positioned under the second engine cover 17.

[0015] A hydraulic oil tank 20 and a fuel tank 21 are disposed on the front side of the second engine cover 17 of the machine room 15. The hydraulic oil stored in the hydraulic oil tank 20 is pressure-fed by the hydraulic pump to the boom cylinder 12, the arm cylinder 13, and the bucket cylinder 14, and the boom cylinder 12, the arm cylinder 13, and the bucket cylinder 14 are operated by the pressure-fed hydraulic oil.

[0016] The fuel tank 21 is disposed on the front side of the hydraulic oil tank 20. The fuel tank 21 is provided with a fuel supply port 23 protruding from an upper portion of the left side surface of the fuel tank 21. Here, in the present embodiment, fuel is supplied to the fuel tank 21 via the fuel supply port 23 by a fuel supply device 30 according to the present embodiment which will be described later. The fuel stored in the fuel tank 21 is supplied to the engine, and the engine is driven by the supplied fuel.

[0017] On the right side of the cab 6 and at the center of the revolving frame 7, a work device mounting portion 18 for mounting the boom 9 is disposed. A base end portion of the boom 9 is attached to the work device mounting portion 18 so as to be capable of ascending and descending movement.

[0018] On the front side of the fuel tank 21 and on the right side of the work device mounting portion 18, a step 24 for a worker is provided. This step 24 for a worker is used when the worker climbs onto the vehicle body 2 for maintenance work.

[0019] As shown in Figure 3, step 24 includes a first step 25 protruding to the front side of the revolving frame 7, a second step 26 constituted by a stepped portion that is one step lower than the upper end surface 21a of the fuel tank 21, and a third step 27 protruding from the front end surface 21b of the fuel tank 21.

[0020] As shown in Figure 4, a storage space 28 consisting of a space with a predetermined volume is provided below the second step 26, and a lid 35 is disposed at an opening 29 of the storage space 28 so as to be openable and closable. That is, this lid 35 is utilized as the second step 26.

[0021] A fuel supply device 30 is disposed in the storage space 28. As shown in Figure 5, the fuel supply device 30 has a fuel supply line A that supplies fuel from an external container such as a drum can containing fuel to the fuel tank 21. Specifically, the fuel supply line A is configured to include a first fuel supply pipe 64, a second fuel supply pipe 65, a third fuel supply pipe 74, a fuel filter case 33, and the like, which will be described later. The fuel supply device 30 further includes a fuel pre-filter 32 which is a fuel filter for filtering fuel, a fuel filter case 33 that accommodates the fuel pre-filter 32, a fuel introduction pump 34 that introduces fuel into the fuel filter case 33, a fuel property sensor 36 that is disposed in the fuel filter case 33 and detects the property of the fuel introduced into the fuel filter case 33, and a fuel lead-out on-off valve 38 disposed in a lead-out portion 37 that leads the fuel introduced into the fuel filter case 33 toward the fuel tank 21.

[0022] The fuel supply device 30 is controlled by a controller 39. The controller 39 determines whether the fuel is poor or normal based on the detection result of the fuel property sensor 36, and performs control to close the fuel lead-out on-off valve 38 if the fuel is poor, and to open the fuel lead-out on-off valve 38 if the fuel is normal.

[0023] As shown in Figure 6, the fuel filter case 33 includes a bottomed cylindrical case body 40 and a circular sealing body 42 that closes the upper end opening 41 of the case body 40. A flange portion 44 is formed on the periphery of the bottom wall 43 of the case body 40, projecting radially outward. As shown in Figure 5, the flange portion 44 has a substantially rectangular shape in plan view, and through holes 44a are provided at the four corners. The fuel filter case 33 is fixed to a predetermined mounting location (not shown) using screws or the like, utilizing the through holes 44a of the flange portion 44.

[0024] As shown in Figure 6, an annular flange 45 is formed around the periphery of the upper end opening 41 of the fuel filter case 33, and it matches the sealing body 42. The flange 45 is provided with female screw holes 46 that are evenly spaced in the circumferential direction. The sealing body 42 is also provided with through holes 47 that are evenly spaced in the circumferential direction, similar to the flange 45, and bolts 49 fitted with washers 48 are inserted through each through hole 47. When these bolts 49 are screwed into the female screw holes 46, the sealing body 42 is fixed to the fuel filter case 33 and closes the upper end opening 41. An O-ring 50 is interposed between the flange 45 and the sealing body 42, and the upper end opening 41 of the fuel filter case 33 is sealed liquid-tight.

[0025] As shown in Figure 6, the case body 40 of the fuel filter case 33 has a partition wall 51 positioned at approximately 1 / 5 of the height from the bottom wall 43 in the vertical direction. The partition wall 51 has a circular outer edge 52 that matches the inner surface 40a of the case body 40 of the fuel filter case 33 and is fixed in a liquid-tight manner, and has a circular bulge 53 that protrudes upward in the center. A cylindrical pipe member 54 with a smaller diameter and a circular cross-section than the bulge 53 is inserted through the center of this bulge 53. The cylindrical pipe member 54 is long and is erected in the center of the case body 40 of the fuel filter case 33, with its upper end opening 54a positioned above the midpoint of the vertical length of the fuel filter case 33.

[0026] A valve 90 is fitted into the upper end opening 54a of the cylindrical pipe member 54. The valve 90 is a check valve, and when the fuel pressure on the upper side 91 of the valve exceeds a predetermined pressure, it allows fuel to flow to the lower side 94 of the valve. In addition, the flow of fuel from the lower side 94 of the valve to the upper side 91 of the valve is blocked by the valve 90.

[0027] The inside of the fuel filter case 33 is connected to the upper and lower regions of the partition wall 51 by a cylindrical member 54.

[0028] As shown in Figure 6, a fuel pre-filter 32 is disposed inside the fuel filter case 33. Here, the fuel pre-filter 32 is located upstream of the fuel property sensor 36 in the direction of fuel flow supplied to the fuel tank 21. The fuel pre-filter 32 is cylindrical with a smaller diameter than the fuel filter case 33, and separates foreign matter and moisture from the fuel as it enters from the outer surface 32a and reaches the inner surface 32b. The inner diameter of the fuel pre-filter 32 is approximately the same as the outer diameter of the bulge 53 of the partition wall 51, and it is fitted into the bulge 53. The lower end portion 32c of the fuel pre-filter 32 is in contact with the flat portion 55 of the partition wall 51. A cap member 56 is fitted onto the upper end portion 32d of the fuel pre-filter 32. The cap member 56 closes the opening 32e of the upper end portion 32d of the fuel pre-filter 32. Furthermore, a compression coil spring 57 is provided between the cap member 56 and the inner surface 42a of the sealing body 42. This compression coil spring 57 biases the fuel prefilter 32 toward the partition wall 51.

[0029] In the fuel filter case 33, the area below the partition wall 51, that is, the area defined by the bottom wall 43, the inner circumferential surface 40a of the case body 40, and the partition wall 51, becomes the main storage chamber 58 where fuel that flows in from the upper end opening 54a of the cylindrical pipe member 54, from the fuel that has had foreign matter and moisture separated and removed by the fuel prefilter 32, is stored.

[0030] Furthermore, the area above the partition wall 51, defined by the partition wall 51, the inner circumferential surface 32b of the fuel prefilter 32, the outer circumferential surface 54b of the cylindrical pipe member 54, and the cap member 56, becomes a sub-storage chamber 59 where fuel from which foreign matter and moisture have been separated and removed by the fuel prefilter 32 is temporarily stored.

[0031] Furthermore, the area above the partition wall 51, defined by the partition wall 51, the outer circumferential surface 32a of the fuel pre-filter 32, the inner circumferential surface 40a of the case body 40 of the fuel filter case 33, and the sealing body 42, becomes a pre-storage chamber 60 where fuel is temporarily stored before foreign matter and moisture are separated and removed by the fuel pre-filter 32.

[0032] In other words, the fuel filter case 33 includes a storage chamber 61 consisting of a main storage chamber 58, a sub-storage chamber 59, and a pre-storage chamber 60. The partition wall 51 separates the water separated from the fuel by the fuel pre-filter 32 and the fuel that has passed through the fuel pre-filter 32 between the pre-storage chamber 60 and the main storage chamber 58 within the fuel filter case 33.

[0033] The pre-storage chamber 60 is provided with a fuel inlet 62 through which fuel is introduced. As is clear from Figure 6, the fuel inlet 62 is located on the upper part of the side of the case body 40, close to the upper end opening 41 of the fuel filter case 33. As shown in Figure 5, one end 63a of an L-shaped pipe fitting 63 is connected to the fuel inlet 62. The other end 63b of the L-shaped pipe fitting 63 is connected to one end 64a of the first fuel supply pipe 64, and the other end 64b of the first fuel supply pipe 64 is connected to the outlet 34a of the fuel introduction pump 34. One end 65a of the second fuel supply pipe 65 is connected to the inlet 34b of the fuel introduction pump 34. The other end of the second fuel supply pipe 65 is connected to an external container such as a drum containing fuel.

[0034] Furthermore, as shown in Figure 6, a water drain port 66 is provided in the pre-storage chamber 60. The water drain port 66 works to discharge the water contained in the fuel, which is separated by the fuel pre-filter 32 and accumulates in the lower part of the pre-storage chamber 60, to the outside of the fuel filter case 33. As is clear from Figure 6, the water drain port 66 includes a water discharge pipe 68 connected to a water outlet 67 provided in the lower part of the pre-storage chamber 60, that is, slightly above the partition wall 51 on the side of the case body 40 of the fuel filter case 33, a water shut-off valve 69 provided at the end of the water discharge pipe 68, and a water drain hose 70 provided at the outlet 69a of the water shut-off valve 69. It is preferable that the water outlet 67 be provided in the part where the water contained in the fuel is separated by the difference in specific gravity and accumulates. The water that has accumulated as described above is discharged from the end port 71 of the water drain hose 70 by operating the water shut-off valve 69.

[0035] A fuel properties sensor 36 is installed in the main storage chamber 58. The fuel properties sensor 36 uses a sensor that detects, for example, the concentration of sulfur components contained in the fuel. Here, an example of a substandard fuel containing unsuitable components is a fuel containing a high concentration of sulfur components. Using such a substandard fuel containing a high concentration of sulfur components may reduce the durability of the engine, and the exhaust gas purification device and fuel injection device may not function properly, potentially leading to deterioration of engine performance, damage, or failure. For this reason, the concentration of sulfur components in the fuel is detected to determine whether or not it is substandard fuel. As shown in Figure 6, the fuel properties sensor 36 is installed on the side of the case body 40 of the fuel filter case 33 in the main storage chamber 58. A harness (not shown) is connected to the fuel properties sensor 36, and this harness is connected to a controller 39, which will be described later (see Figure 7). As a result, the detection information from the fuel properties sensor 36, i.e., the concentration of sulfur components contained in the fuel in the main storage chamber 58, is transmitted to the controller 39 via the harness.

[0036] Here, the detection accuracy of the fuel properties sensor 36 decreases if the fuel contains moisture, so it is preferable to place it in a location that avoids areas where moisture in the fuel accumulates. In this embodiment, since there is a part in the pre-storage chamber 60 where moisture accumulates, the fuel properties sensor 36 is placed in the main storage chamber 58, avoiding this part. In other words, the fuel properties sensor 36 is installed in the fuel filter case 33 on the side of the fuel pre-filter 32 where the fuel that has passed through the fuel pre-filter 32 is stored (main storage chamber 58), which is partitioned by the partition wall 51.

[0037] Furthermore, a fuel outlet 72 is provided in the main storage chamber 58. As shown in Figure 6, the outlet 72 is located at a predetermined position on the side of the case body 40 of the fuel filter case 33 in the main storage chamber 58. As shown in Figure 5, one end 73a of an L-shaped pipe fitting 73 is connected to this outlet 72. The fuel outlet section 37 is formed by the outlet 72 and the L-shaped pipe fitting 73. The inlet 38a of a fuel outlet valve 38 is connected to the other end 73b of the L-shaped pipe fitting 73. Here, the fuel outlet valve 38 is provided in the fuel supply pipeline A (L-shaped pipe fitting 73) downstream of the fuel property sensor 36 in the direction of fuel flow supplied to the fuel tank 21. One end 74a of the third refueling pipe 74 is connected to the outlet 38b of the fuel outlet valve 38. This fuel outlet valve 38 opens and closes the outlet 72. A harness (not shown) is connected to the fuel outlet valve 38, and this harness is connected to a controller 39, which will be described later (see Figure 7). This allows the controller 39 to transmit commands to the fuel outlet valve 38. Meanwhile, the other end 74b of the third refueling pipe 74 is connected to the fuel tank 21 via the refueling port 23.

[0038] Furthermore, a fuel outlet 75 is provided in the center of the bottom of the main storage chamber 58, that is, in the center of the bottom wall 43 of the case body 40, and a fuel drain port 76 is provided at this fuel outlet 75. As is clear from Figure 6, the fuel drain port 76 includes a fuel discharge pipe 77 connected to the fuel outlet 75, a fuel shut-off valve 78 provided at the end of the fuel discharge pipe 77, and a fuel drain hose 79 provided at the outlet 78a of the fuel shut-off valve 78. It is preferable that the fuel outlet 75 be provided at the very bottom of the fuel filter case 33, that is, in the bottom wall 43, to facilitate fuel discharge. At the fuel drain port 76, fuel is discharged from the end port 80 of the fuel drain hose 79 by operating the fuel shut-off valve 78.

[0039] In other words, the fuel filter case 33 has a fuel drain port 76 located upstream of the fuel outlet valve 38 in the direction of fuel flow supplied to the fuel tank 21, and on the side of the fuel filter case 33 partitioned by the partition wall 51 where fuel that has passed through the fuel pre-filter 32 is stored (main storage chamber 58).

[0040] Furthermore, the fuel supply device 30 is equipped with a pump switch 81 that switches the fuel injection pump 34 ON / OFF. The pump switch 81 includes an operation button (not shown) and integrates a warning lamp 82 as a warning device. As shown in Figures 4 and 5, the pump switch 81 is located near the fuel filter case 33. A harness 88 is connected to the pump switch 81, and the pump switch 81 is connected to the controller 39 via this harness 88 (see Figure 7). The fuel injection pump 34 and the warning lamp 82 are electrically connected to the controller 39 (see Figure 7). As a result, the fuel injection pump 34 is controlled via the controller 39 in response to the operation of the pump switch 81. Also, if substandard fuel is detected, a command is sent from the controller 39 to the warning lamp 82, causing the warning lamp 82 to illuminate and warn the operator. Here, the warning device is not limited to the warning lamp 82; a warning buzzer may also be used.

[0041] In other words, the fuel supply device 30 further includes a warning lamp 82 as a warning device, and the controller 39 issues a warning using the warning lamp 82 (the warning lamp 82 lights up) if the fuel properties detected by the fuel properties sensor 36 are poor.

[0042] Next, the system configuration of the fuel supply device 30 and its peripheral equipment will be described based on Figure 7. First, the fuel supply device 30 includes a fuel filter case 33, a fuel introduction pump 34 for introducing fuel into the fuel filter case 33, a fuel property sensor 36 for detecting the properties of the fuel introduced into the fuel filter case 33, a fuel outlet on / off valve 38 that can adjust the injection of the fuel discharged from the fuel filter case 33 into the downstream fuel tank 21, a pump switch 81 for switching the fuel introduction pump 34 ON / OFF, and a warning lamp 82 which serves as a warning device that issues a warning when substandard fuel is detected.

[0043] Next, the peripheral equipment includes a controller 39 that switches the fuel inlet pump 34 ON / OFF, reads information from the fuel condition sensor 36 and controls the opening and closing of the fuel outlet valve 38 based on this information, and controls the operation of a warning device when substandard fuel is detected; a fuel tank 21 located downstream of the fuel outlet valve 38 and receiving fuel supply; a main fuel filter 83 located downstream of the fuel tank 21 and filtering the fuel again; a main fuel pump 84 located downstream of the main fuel filter 83 and sending the filtered fuel to the engine 85; and an engine 85 located downstream of the main fuel pump 84. These fuel tank 21, main fuel filter 83, main fuel pump 84, and engine 85 are connected by predetermined fuel supply piping to allow fuel to flow. A fuel meter 86 is installed in the fuel tank 21, which can measure the amount of fuel injected into the fuel tank 21. This fuel injection amount information is transmitted to the controller 39.

[0044] Next, the refueling operation using the fuel supply device 30 according to this embodiment will be described. The operator connects the second fuel supply pipe 65 to an external container such as a drum. Then, the operator operates the pump switch 81 to drive the fuel introduction pump 34 via the controller 39. As a result, the fuel in the external container passes through the second fuel supply pipe 65 to the fuel introduction pump 34. The fuel then passes through the first fuel supply pipe 64 and the L-shaped pipe fitting 63 and is introduced into the pre-storage chamber 60 of the fuel filter case 33 from the fuel inlet 62. At this point, the water shut-off valve 69 is closed, so the introduced fuel is stored in the pre-storage chamber 60 and its volume increases. At the same time, the fuel passes from the outer surface 32a to the inner surface 32b of the fuel pre-filter 32. At this point, the fuel contained in the external container may contain moisture. In this way, fuel containing moisture is separated into water and fuel by the fuel pre-filter 32 in the pre-storage chamber 60, where the water droplets contained in the fuel are enlarged. Due to the difference in specific gravity between water and fuel, the water accumulates at the bottom of the pre-storage chamber 60, and the fuel from which the moisture has been separated passes through the fuel pre-filter 32. The fuel from which the moisture has been separated is then stored in the sub-storage chamber 59. In Figure 6, the path of fuel containing moisture is shown by a diagonal arrow, the path of water is shown by a white arrow, and the path of fuel (fuel from which the moisture has been separated) is shown by a black arrow. In the process of following the paths of the arrows shown in Figure 6, moisture is separated and foreign matter is removed by the fuel pre-filter 32, and the fuel accumulates in the sub-storage chamber 59.

[0045] Here, once a certain amount of separated water has accumulated, the water can be discharged to the outside from the fuel filter case 33 by opening the water drain port 66's water shut-off valve 69.

[0046] Subsequently, fuel accumulates up to the top of the valve 90 located at the upper end opening 54a of the cylindrical pipe member 54 within the sub-storage chamber 59. When the fuel pressure on the upper valve side 91 exceeds a predetermined pressure, fuel flows from the inlet 92 of the valve 90 to the lower valve 94. The fuel then enters the cylindrical pipe member 54 and passes through it to reach the main storage chamber 58. At this time, the fuel on-off valve 78 and the fuel outlet on-off valve 38 are closed. As a result, fuel accumulates in the main storage chamber 58.

[0047] Next, the controller 39 starts the control process shown in Figure 8. First, the controller 39 reads the detection information from the fuel properties sensor 36 regarding the fuel accumulated in the main storage chamber 58, that is, the detection information of the concentration of sulfur components contained in the fuel, and proceeds to step S1. In step S1, it determines whether the fuel being refueled is of poor quality or not. Specifically, it determines whether the concentration of sulfur components contained in the fuel is above a specified value.

[0048] If the result in step S1 is "Yes," that is, if the fuel is of poor quality, the process proceeds to step S2. In step S2, a control signal is output to the fuel outlet valve 38 to close the valve, closing the fuel outlet valve 38 and blocking the fuel supply line A, thereby cutting off the supply of fuel to the fuel tank 21. This prevents the poor quality fuel from entering the fuel tank 21. Then, the process proceeds to step S3, where a warning is issued to the refueling operator. Specifically, the controller 39 outputs a signal to the warning lamp 82, causing the warning lamp 82 to illuminate and ending the control process.

[0049] Here, the poor quality fuel accumulated in the main storage chamber 58 can be discharged to the outside from the fuel filter case 33 by opening the fuel on / off valve 78 of the fuel drain port 76.

[0050] On the other hand, if the result in step S1 is "No", the process proceeds to step S4. In step S4, the controller 39 outputs a control signal to the fuel outlet valve 38 to open it. Then, the process proceeds to step S5, and refueling is performed into the fuel tank 21. After that, the process proceeds to step S6 to determine if the fuel tank 21 is full. Specifically, the amount of fuel injected is detected from the fuel meter 86 installed in the fuel tank 21, and it is determined whether the injected amount is equal to or greater than the specified value. If the result in step S6 is "No", the process returns to step S1 to determine again whether the fuel being refueled is of poor quality or not.

[0051] On the other hand, if "Yes" is determined in step S6, the process proceeds to step S7, and the fuel outlet valve 38 is closed. Specifically, the controller 39 outputs a control signal to the fuel outlet valve 38 to close the valve, and the control process ends.

[0052] As described above, with the fuel supply device 30 according to this embodiment, if the fuel being supplied is of poor quality, the fuel outlet shut-off valve 38 can be closed, stopping the poor quality fuel at the fuel filter case 33, thus preventing the poor quality fuel from being injected into the fuel tank 21. Therefore, with the construction machine of this embodiment, it is possible to prevent the accidental injection of poor quality fuel, and the risks of downtime due to recovery work performed when poor quality fuel is accidentally supplied, which have been problems in the past, and the risks of engine damage are reduced.

[0053] It should be noted that the embodiments of the present invention are not limited to those described above. In the above embodiments, a hydraulic excavator 1 was described as an example, but the present invention is not limited to this embodiment and may be applied to any construction machine that requires fuel. [Explanation of symbols]

[0054] 1. Hydraulic excavator 2 car bodies 3 Lower running body 4. Upper rotating body 5. Working equipment 6 cabs 7. Swivel Frame 8 counterweights 9 Boom 10 Arms 11 buckets 21 Fuel tank 23 Fueling Port 30 Fuel supply system 32 Fuel pre-filter 33 Fuel filter case 34 Fuel Injection Pump 36 Fuel properties sensor 38 Fuel outlet shut-off valve 39 Controllers 58 Main storage room 59 Sub-storage chamber 60 Pre-storage chamber 61 Storage chamber 81 Pump switch 82 Warning lights 85 engine A Fuel supply pipe

Claims

1. A construction machine having a fuel tank, A fuel supply device having a fuel supply pipeline connected to the fuel tank, which supplies and stores fuel in the fuel tank via the fuel supply pipeline, The system includes a controller for controlling the fuel supply device, The fuel supply device is A sensor that detects the properties of the fuel, The fuel supply pipeline is provided with an on / off valve located downstream of the sensor in the direction of fuel flow supplied to the fuel tank, The aforementioned controller, If the fuel quality detected by the sensor is poor, the shut-off valve is closed to block the fuel supply line and cut off the supply of fuel to the fuel tank. A construction machine characterized by the following features.

2. The aforementioned fuel supply device further includes a warning device, The controller will issue a warning via the warning device if the fuel properties detected by the sensor are of poor quality. The construction machine according to feature 1.

3. The fuel supply device further includes a fuel filter for filtering fuel. The fuel filter is provided upstream of the sensor in the direction of fuel flow supplied to the fuel tank. The construction machine according to feature 1.

4. The fuel supply device further comprises a fuel filter case that houses the fuel filter, The fuel filter case has a partition wall that separates the water separated from the fuel by the fuel filter from the fuel that has passed through the fuel filter within the fuel filter case. The sensor is installed in the fuel filter case on the side of the fuel filter case partitioned by the partition wall that stores the fuel that has passed through the fuel filter. The construction machine according to feature 3.

5. The fuel filter case has a drain port located upstream of the on / off valve in the direction of fuel flow supplied to the fuel tank, and on the side of the fuel filter case partitioned by the partition wall where the fuel that has passed through the fuel filter is stored. The construction machine according to feature 4.

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