JP7460410B2 - Excavators and excavator fuel filters - Google Patents

Description

This disclosure relates to a shovel.

2. Description of the Related Art Excavators are known in which a main filter is provided in a fuel supply path from a fuel tank to an engine to remove foreign matter such as dust in the fuel (see, for example, Patent Document 1). This main filter has a structure for separating water from fuel. This is to prevent a large amount of water from being supplied to the engine together with fuel. Water separated from the fuel is stored in a predetermined space within the filter, and is periodically discharged to the outside via a drain cock.

There is also known an excavator in which a fuel filter is additionally provided downstream of the main filter in the fuel supply path (see, for example, Patent Document 2). This fuel filter is installed to remove foreign matter that may enter the fuel supply path from the part where the main filter was installed when the main filter is temporarily removed for maintenance.

JP 2016-176239 A Japanese Patent Application Publication No. 2018-003690

However, if the fuel filter has a structure for separating water, there is a risk that the water separated from the fuel will accumulate inside the filter and cause a malfunction. If only water is supplied to the engine, it may lead to the engine stalling and even cause engine failure. If the engine fails, it may take a lot of time to replace the engine, which may reduce work efficiency.

In view of the above problems, it is desirable to provide an excavator equipped with a fuel filter that can suppress the occurrence of malfunctions and reduce the decrease in work efficiency.

An excavator according to an embodiment of the present invention includes a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, a fuel tank mounted on the upper rotating body, and a fuel tank mounted on the upper rotating body. a main filter provided in a fuel supply path between the fuel tank and the engine; and a fuel filter provided between the main filter and the engine in the fuel supply path, The filter has an upper opening and a lower opening, and fuel flows into the filter through one of the upper opening and the lower opening, and the fuel flows into the filter through the other of the upper opening and the lower opening. The lower opening is an opening formed in the side or lower surface of the filter housing of the fuel filter, and the lower opening has a hollow shaft through which the fuel flows. The lower opening and the hollow shaft do not protrude into the space within the fuel filter.

The above-mentioned means provide a shovel equipped with a fuel filter that can suppress the occurrence of malfunctions and reduce the decline in work efficiency.

FIG. It is a top view of an upper revolving structure. It is a side view of a pump chamber. It is a figure showing an example of composition of a fuel supply system. FIG. 4 is a diagram showing another example of the configuration of the fuel supply system. FIG. 13 is a diagram illustrating an example of the configuration of a prefilter. It is a figure showing an example of composition of a fuel filter. It is a sectional view of a banjo joint and a banjo bolt. It is a figure which shows another structural example of a fuel filter. It is a figure which shows yet another structural example of a fuel filter.

First, the basic configuration of an excavator 100 according to an embodiment of the present invention will be described with reference to Figs. 1 to 3. Hereinafter, the direction in which the boom 4 is attached as viewed from the center of the upper rotating body 3, i.e., the direction in which the boom 4 extends relative to the upper rotating body 3, will be referred to as "front", and the opposite direction will be referred to as "rear". Fig. 1 is a side view of an excavator 100 according to this embodiment. The excavator 100 according to this embodiment mainly comprises a lower traveling body 1, an upper rotating body 3, a boom 4, an arm 5, a bucket 6, and a cab 10. Fig. 2 is a plan view of the upper rotating body 3. Fig. 3 is a side view of the pump room 40, specifically, a view of the pump room 40 as viewed from the side as indicated by the arrow AR in Fig. 2.

The upper rotating body 3 is rotatably mounted on the lower traveling body 1 via a rotating mechanism (not shown). A cab 10 is provided at the front left side of the upper revolving body 3. One end of a boom 4 is rotatably attached to the front center of the upper revolving body 3. The arm 5 is rotatably attached to the tip of the boom 4. A bucket 6 as an end attachment is rotatably attached to the tip of the arm 5. The boom 4, arm 5, and bucket 6 constitute a digging attachment that is an example of an attachment. Note that, instead of the bucket 6, another end attachment such as a breaker or a crusher may be attached to the tip of the arm 5.

As shown in FIG. 2, a diesel engine (hereinafter simply referred to as "engine 11") and components associated with the engine 11 (hereinafter referred to as "ancillary parts") are mounted at the rear of the upper rotating body 3, and an engine hood 200 (see FIG. 1) is attached so as to cover the engine 11 and the associated parts from above. The engine hood 200 is not shown in FIG. 2.

An engine room ER is formed at the rear of the upper rotating body 3 to house the engine 11 and associated parts. As mentioned above, the upper side of the engine room ER is covered by the engine hood 200, but in order to show the interior of the engine room ER, the engine hood 200 is not shown in FIG. 2.

An engine 11 is mounted in the center of the engine room ER (i.e., the rear center of the upper rotating body 3). A silencer (not shown) and an exhaust gas treatment device (not shown) are arranged near the engine 11, for example, in the space on the right side of the engine room ER. The exhaust gas treatment device includes, for example, at least one of an SCR (Selective Catalytic Reduction) system (not shown) and a DPF (Diesel Particulate Filter). Specifically, an exhaust pipe 9 for discharging exhaust gas to the outside is connected to the engine 11, and the exhaust gas treatment device and the like are connected to the downstream end of the exhaust pipe 9. Note that in FIG. 2, the exhaust gas treatment device is omitted in order to illustrate the inside of a pump room 40 provided below the exhaust gas treatment device.

The rotating frame FR of the upper rotating body 3 (see Figure 3) is provided with a pair of central frames 17 that run vertically across the upper rotating body 3 from front to rear. The central frame 17 includes a left central frame 17L and a right central frame 17R. The engine 11 is mounted on the rotating frame FR via mounting rubbers or the like. A maintenance opening AP is provided in a part of the rotating frame FR directly below the engine 11. An operator can perform operations such as changing the oil in the engine 11 through the maintenance opening AP.

The central frame 17 supports the boom 4 at its front end, as shown in FIG. Specifically, the boom 4 passes through the left center frame 17L, the boom 4, and the right center frame 17R while being sandwiched between the front end of the left center frame 17L and the front end of the right center frame 17R. It is rotatably attached to the central frame 17 via a boom foot pin BF.

A cooling fan 12 and a heat exchanger unit 13 including a radiator and the like are mounted on the left side of the engine room ER (that is, the left rear part of the upper revolving structure 3). Specifically, a cooling fan 12 driven by the power of the engine 11 is provided at the left end of the engine 11 in the engine room ER, and a heat exchanger unit 13 is mounted on the left side of the cooling fan 12. has been done.

A pipe 15 through which engine cooling water flows is provided between the engine 11 and the heat exchanger unit 13. A water temperature sensor 16 is provided in the pipe 15 . Water temperature sensor 16 detects the temperature of engine cooling water flowing through pipe 15 and supplies a detection signal to controller 30 .

A pump room 40 is provided on the right side of the engine room ER (i.e., the right rear part of the upper rotating body 3). In order to illustrate the interior of the pump room 40, FIG. 3 does not show the side door that covers the right rear part of the upper rotating body 3.

As shown in FIGS. 2 and 3, a hydraulic pump 14 for circulating hydraulic oil used in the hydraulic system of the excavator 100 is arranged in the pump chamber 40 in such a manner that it can be driven by the power of the engine 11. . Specifically, the hydraulic pump 14 is arranged in the pump chamber 40, and its drive shaft is inserted into a notch 40H provided in the partition plate 40b and connected to the crankshaft of the engine 11.

Further, various components of a fuel supply system for supplying fuel to the engine 11 are arranged in the pump chamber 40 . Specifically, a pre-filter 43, a fuel pump 44, a main filter 45, a pipe 41 connecting these, and the like are arranged within the pump chamber 40. The pipe 41 is a fuel pipe and is configured to connect the fuel tank 19 and the engine 11. A pre-filter 43, a fuel pump 44, a main filter 45, and the like are provided in a portion of the pipe 41 that passes through the inside of the pump chamber 40. A fuel filter 56 as a final filter is provided in a portion of the piping 41 outside the pump chamber 40 and connected to the engine 11. Note that in this embodiment, a goose filter 57 is provided downstream of the fuel filter 56 in the fuel supply path. However, the goose filter 57 may be provided upstream of the fuel filter 56 in the fuel supply path.

At the four corners of the pump chamber 40, struts 40a are arranged upright from the revolving frame FR of the upper revolving structure 3. The pump chamber 40 is provided with a partition plate 40b that connects two of the four pillars 40a on the side adjacent to the engine 11 (the center side of the engine room ER). The partition plate 40b is provided with a notch 40H through which the drive shaft of the hydraulic pump 14 passes.

As shown in FIG. 3, the pre-filter 43, the fuel pump 44, and the main filter 45 are arranged in positions that are visible when the side door is opened. This arrangement allows an operator to easily perform maintenance work such as replacing the pre-filter 43 and the main filter 45. In addition, the pre-filter 43, the fuel pump 44, and the main filter 45 may be attached to a support frame 40c that is installed on two pillars 40a on the rear side of the pump chamber 40, for example.

The fuel filter 56 is disposed in a space on the left side of the pump room 40 in the engine room ER (on the left side of the partition plate 40b in FIG. 3) at a position lower than the engine 11, i.e., lower than the crankshaft of the engine 11. Normally, the worker's viewpoint is near the height at which the hydraulic pump 14 is disposed, so even if the side door is opened, the worker cannot see the fuel filter 56 from the viewpoint of the worker, which is at a relatively high position, because the line of sight is blocked by the partition plate 40b. On the other hand, the fuel filter 56 is disposed in a position accessible to the worker from the underside of the upper rotating body 3 (rotating frame FR) through the maintenance opening AP. The fuel filter 56 may be attached directly to a structure of the upper rotating body 3, such as the central frame 17, or indirectly via a bracket or the like. This allows the worker to separately mount the fuel supply system including the fuel filter 56 and the engine 11 on the upper rotating body 3 when performing the work of mounting various parts on the upper rotating body 3.

In front of the engine room ER, specifically, in the space outside the engine room ER in front of the heat exchanger unit 13 arranged in the left space in the engine room ER, as shown in FIG. 63 (air filter) is arranged. Air cleaner 63 is connected to engine 11 via intake pipe 64. Thereby, the air filtered by the air cleaner 63 is supplied to the engine 11 through the intake pipe 64.

The cab 10 is arranged in front of the air cleaner 63, that is, in the front left side of the upper revolving structure 3. A driver's seat (not shown) is provided inside the cab 10, and a monitor 3a configured with, for example, a liquid crystal display is provided in front of the driver's seat inside the cab 10.

The monitor 3a displays various information indicating, for example, the operating status of the shovel 100 or the operating state of each part in response to a display signal from the controller 30. The operator operates the shovel 100 while checking the various information displayed on the monitor 3a.

The controller 30 is a control device that controls the entire operation of the excavator 100 and the operations of each part, and is mounted in the cab 10, for example. The controller 30 is composed of, for example, a computer including a CPU as an arithmetic unit, and internal memories such as ROM and RAM.

A hydraulic oil tank 120 that stores hydraulic oil used in the hydraulic system is located in front of the engine room ER, specifically, in the space outside the engine room ER in front of the pump chamber 40 provided in the space on the left side of the engine room ER.

Further, in front of the hydraulic oil tank 120, a fuel tank 19 is arranged to store fuel for the engine 11, such as light oil. Fuel stored in the fuel tank 19 is supplied to the engine 11 via piping 41.

A storage tank 20 may be arranged in front of the fuel tank 19 to store a processing agent (for example, an aqueous urea solution as a liquid reducing agent) used by the above-mentioned exhaust gas processing device. The processing agent stored in the storage tank 20 is supplied to an exhaust gas treatment device (not shown) through a processing agent supply pipe (not shown).

In the above configuration, for example, when replacing the main filter 45, there is a risk that foreign matter such as dust may enter the pipe 41 from the portion of the pipe 41 where the main filter 45 is temporarily removed. Particularly, when replacing the main filter 45 at a relatively dusty construction site or the like, foreign matter is likely to enter the pipe 41 from that part. In this case, the fuel containing foreign matter is supplied to the engine 11 without being filtered by the pre-filter 43 and the main filter 45. Therefore, in this embodiment, in addition to the main filter 45 and the pre-filter 43, a fuel filter 56 is provided on the downstream side of the main filter 45 in the piping 41. This configuration suppresses foreign matter from entering the engine 11 when the main filter 45 is replaced.

Below, with reference to FIG. 4, a specific configuration of the fuel supply system including the fuel filter 56 will be described. FIG. 4 is a circuit diagram of an example of a fuel supply system.

In the fuel supply system of the excavator 100 according to the present embodiment, the fuel pump 44 is electrically driven, for example, to supply fuel stored in the fuel tank 19 to the engine 11.

Specifically, when the fuel pump 44 is driven, the fuel in the fuel tank 19 flows through the pipe 41 and flows into the pre-filter 43.

Note that a shutoff valve 42 is provided in a portion 41A of the pipe 41 between the fuel tank 19 and the prefilter 43. Shutoff valve 42 is normally open, allowing fuel to pass through shutoff valve 42 .

The fuel that flows into the prefilter 43 is filtered by the filter element FE (see Figure 6), and relatively large foreign objects are removed. The prefilter 43 is also provided with a water separator 50 including a water level detector 52, which separates the water contained in the fuel, and the amount of separated water is detected as the water level by the water level detector 52.

The fuel that passes through the prefilter 43 flows through part 41B of the pipe 41, is sucked into the fuel pump 44, and is discharged from the fuel pump 44. The fuel discharged from the fuel pump 44 flows through part 41C of the pipe 41 and enters the main filter 45.

The fuel that has flowed into the main filter 45 is filtered by the main filter 45 to further remove relatively fine foreign matter. The fuel that has passed through the main filter 45 flows through a portion 41D of the pipe 41 and flows into the fuel filter 56.

The fuel filter 56, like the pre-filter 43 and the main filter 45, has the function of removing (filtering) foreign substances contained in the fuel. The fuel filter 56 is, for example, a filter having the same coarseness as the main filter 45 or a filter having a coarser mesh than the main filter 45. As described above, the pre-filter 43 removes relatively large foreign substances, and the main filter 45 removes relatively small foreign substances, so the fuel flowing into the fuel filter 56 is normally filtered by the fuel filter 56. Contains almost no foreign matter. On the other hand, when replacing the main filter 45, there is a risk that foreign matter may enter the fuel supply system (piping 41) from the portion of the piping 41 from which the main filter 45 is removed. Therefore, by disposing the fuel filter 56 downstream of the main filter 45 in the fuel supply system, foreign matter that has entered the pipe 41 from the portion of the pipe 41 from which the main filter 45 has been removed is prevented from entering the engine 11. can be removed (filtered) beforehand.

As mentioned above, the pre-filter 43 and main filter 45 usually remove most of the foreign matter in the fuel, so the fuel filter 56 does not need to be replaced, and even if it is replaced, the frequency is much lower than that of the pre-filter 43 and main filter 45.

The fuel that has passed through the fuel filter 56 is then supplied to the engine 11 after passing through a gas filter 57 . The fuel supplied to the engine 11 is injected into the cylinders of the engine 11 by a fuel injection device (not shown). Fuel that has not been injected into the cylinders of the engine 11 flows through the fuel return pipe 48 and is returned to the fuel tank 19.

A fuel cooler 49 is provided in the fuel return pipe 48, which lowers the temperature of the fuel returning to the fuel tank 19.

Thus, in the example shown in FIG. 4, the fuel filter 56 is provided in the portion of the pipe 41 serving as the fuel supply path between the main filter 45 and the engine 11. With this configuration, the fuel filter 56 can prevent foreign matter from entering the engine 11 through the portion of the pipe 41 from which the main filter 45 is removed when replacing the main filter 45.

Further, as described above, the fuel filter 56 is arranged at a position where the operator cannot see it from the outside even if the door covering the pump chamber 40 is opened. This arrangement can prevent an operator from accidentally replacing the fuel filter 56 when replacing the main filter 45 in the pump chamber 40.

As mentioned above, the fuel filter 56 is accessible from the maintenance opening AP on the underside of the engine 11, so if replacement is absolutely necessary, an operator can replace the fuel filter 56 through the maintenance opening AP.

In the example shown in FIG. 4, the fuel pump 44 is electrically driven, but as shown in FIG. 5, it may be attached to the engine 11 and driven by the power of the engine 11. FIG. 5 is a circuit diagram of another example of a fuel supply system. The fuel supply system shown in FIG. 5 differs from the fuel supply system shown in FIG. 4 having an electrically driven fuel pump 44 in that the fuel pump 44 is driven by the power of the engine 11, but is otherwise the same as the fuel supply system shown in FIG. 4.

Next, a configuration example of the prefilter 43 will be described with reference to FIG. 6. FIG. 6 is a diagram showing a configuration example of the prefilter 43. Specifically, FIG. 6 is a cross-sectional view of the prefilter 43.

The prefilter 43 has an inlet port Pa formed on the left side (-X side) of the upper end and an outlet port Pb formed in the center of the upper end. Fuel containing moisture enters the space inside the filter element FE attached inside the prefilter 43 through the inlet port Pa. At this time, the fuel containing moisture is separated into water and fuel. That is, fuel with a lower specific gravity than water moves upward as shown by the solid arrow, and water with a higher specific gravity than fuel moves downward as shown by the dashed arrow. Then, the fuel passes through the filter element FE from the inside to the outside and exits the filter element FE, and then flows out of the prefilter 43 through the outlet port Pb. Water passes through the filter element FE from the inside to the outside and exits the filter element FE, and is stored in the water reservoir RV formed at the bottom of the prefilter 43.

The prefilter 43 incorporates a water separation device 50 equipped with a water level detection device 52. The water separation device 50 is a device for separating water contained in fuel, and is composed of a filter element FE, a water storage section RV, and a water drain cock CK. As the fuel passes through the prefilter 43, it is filtered by the filter element FE and the water in the fuel is separated. The separated water is stored in the water storage section RV. The water storage section RV is equipped with a water drain cock CK. An operator can open the water drain cock CK to drain the water stored in the water storage section RV to the outside.

As shown in FIG. 6, the water reservoir RV is provided with a float-type water level detector 52. The water level detector 52 includes a detection shaft 52a, a float 52b, and a detection unit 52c. The detection shaft 52a is a hollow, elongated cylindrical member with a closed upper end. The lower end of the detection shaft 52a is connected to the detection unit 52c. The donut-shaped float 52b with a hole in the center can move up and down (Z-axis direction) along the detection shaft 52a.

In this embodiment, the water level detection device 52 includes a magnetic sensor. The magnetic sensor is arranged in the detection shaft 52a and is configured to detect a magnetic field caused by a permanent magnet provided inside the float 52b. An electric circuit in the detection unit 52c identifies the position of the float 52b based on the magnitude of the magnetic field caused by the permanent magnet inside the float 52b detected by the magnetic sensor, and outputs an electric signal related to the position to the controller 30. The detection unit 52c of the water level detection device 52 is connected to the controller 30 via an electric cable 52d.

When water accumulates in the water storage portion RV, the float 52b floats on the water and rises to near the water surface. Therefore, the position of the float 52b corresponds to the water level of the water stored in the water reservoir RV. The electrical signal output from the water level detection device 52 includes information regarding the water level of the water stored in the water reservoir RV.

In this embodiment, the controller 30 receives information regarding the water level from the water level detection device 52. The controller 30 then determines whether the water level exceeds a preset upper limit. When the controller 30 determines that the water level exceeds the upper limit, it displays information indicating that the water level exceeds the upper limit on the monitor 3a to alert the operator.

In this embodiment, the main filter 45 has the same configuration as the pre-filter 43. However, the main filter 45 may not be provided with the water level detection device 52.

Next, an example of the configuration of the fuel filter 56 will be described with reference to FIG. 7. FIG. 7 is a diagram showing an example of the configuration of the fuel filter 56. Specifically, FIG. 7 is a partial cross-sectional view of the fuel filter 56. FIG. 7 shows a side view, rather than a cross-section, of the filter element FE.

The fuel filter 56 is mainly composed of a filter housing FH, a filter element FE, a banjo fitting BJ, and a banjo bolt BT.

The filter housing FH is configured to separate a space SP for accommodating a filter element FE. In the example shown in FIG. 7, the filter housing FH is configured to be separable into an upper filter housing UFH and a lower filter housing LFH. The lower filter housing LFH is screwed to the upper filter housing UFH. An operator can access the filter element FE accommodated in the space SP by separating the lower filter housing LFH from the upper filter housing UFH.

The banjo bolt BT is a member for fastening the banjo joint BJ to the filter housing FH. In the example shown in FIG. 7, the banjo bolt BT includes an upper banjo bolt UBT and a lower banjo bolt LBT, and the banjo joint BJ includes an upper banjo joint UBJ and a lower banjo joint LBJ.

The lower banjo joint LBJ includes a conduit portion CD and an annular portion AN. The annular portion AN has a through hole H0 for receiving the lower banjo bolt LBT, as shown in FIG. 8. FIG. 8 shows a cross section in a virtual plane parallel to the XY plane including the virtual dashed line L1 in FIG. 7. An inner peripheral recess RC is formed in a part of the inner circumference of the through hole H0 so that fuel spreads to the entire outer circumference of the hollow shaft portion of the banjo bolt BT inserted into the through hole H0. For clarity, the inner peripheral recess RC is shown in a dot pattern in FIGS. 7 and 8. The inner peripheral recess RC is connected to a flow path FC1 formed in the conduit portion CD. The conduit portion CD of the lower banjo bolt LBT is configured to extend parallel to the X axis, but may be configured to extend non-parallel to the X axis, i.e., obliquely with respect to the X axis.

The lower banjo joint LBJ is fastened to the first port P1, which is a lower opening formed in the lower filter housing LFH, by a lower banjo bolt LBT. At this time, the lower banjo joint LBJ is fastened to the first port P1 by the lower banjo bolt LBT while being sandwiched between the pair of washers WS.

Upper banjo joint UBJ, like lower banjo joint LBJ, includes a conduit portion CD and an annular portion AN. The annular portion AN has a through hole H0 that receives the upper banjo bolt UBT. An inner periphery recess RC is formed in a part of the inner periphery of the through hole H0 so that fuel spreads over the entire outer periphery of the hollow shaft portion of the banjo bolt BT inserted into the through hole H0.

The upper banjo fitting UBJ is fastened to a second port P2, which is an upper opening formed in the upper filter housing UFH, by an upper banjo bolt UBT. At this time, the upper banjo fitting UBJ is fastened to the second port P2 by the upper banjo bolt UBT while being sandwiched between a pair of washers WS. The conduit portion CD of the upper banjo bolt UBT is configured to extend parallel to the Z axis, but may also be configured to extend non-parallel to the Z axis, i.e., obliquely with respect to the Z axis.

Although the second port P2 is formed on the right side surface (+X side surface) of the upper filter housing UFH, it may also be formed on the left side surface (-X side surface) of the upper filter housing UFH. It may be formed on the front surface (invisible +Y side surface), the rear surface (invisible -Y side surface), or the top surface (+Z side surface). good.

As shown by the arrow AR0 in FIG. 7, the fuel flows through the conduit portion CD of the lower banjo joint LBJ into the inner peripheral recess RC formed in the lower banjo joint LBJ.

The inner peripheral recess RC formed in the lower banjo joint LBJ is configured to face the through hole H1 formed in the hollow shaft portion of the lower banjo bolt LBT inserted into the lower banjo joint LBJ. In the example of FIG. 7, the through hole H1 is composed of four through holes (first through hole H1a to fourth through hole H1d). However, the through hole H1 may be composed of three or less through holes, or may be composed of five or more through holes.

The fuel that has flowed into the inner circumferential recess RC passes through the through hole H1 and flows into the flow path FC2 formed in the hollow shaft portion of the lower banjo bolt LBT, as shown by the arrow AR1 in FIG. Specifically, the fuel flows into the flow path FC2 through the first through hole H1a as shown by the arrow AR1a in FIG. 8, and into the flow path FC2 through the second through hole H1b as shown by the arrow AR1b. It flows into the flow path FC2 through the third through hole H1c as shown by the arrow AR1c, and flows into the flow path FC2 through the fourth through hole H1d as shown by the arrow AR1d.

The fuel that flows into flow path FC2 then passes through flow path FC3, the lower space LS, and the side space CS formed in the lower filter housing LFH, as shown by arrow AR2 in Figure 7, to the filter element FE, and then passes through the filter element FE to the space inside the filter element FE. The dashed portion of arrow AR2 shows the flow of fuel in the space inside the filter element FE. The fuel that flows into the lower space LS agitates the fuel that was in the lower space LS, and reaches the filter element FE together with the fuel that was in the lower space LS.

Note that the lower space LS, which is a part of the space SP, is a cylindrical space between the lower end surface of the filter element FE and the bottom surface of the lower filter housing LFH. Further, the side space CS, which is another part of the space SP, is a cylindrical space between the filter element FE and the inner peripheral surface of the lower filter housing LFH.

The fuel that has flowed into the space inside the filter element FE then passes through an opening formed in the upper end surface of the filter element FE and flows into a flow path FC4 formed in the upper filter housing UFH, as shown by the arrow AR3 in Figure 7. The dashed line portion of the arrow AR3 indicates the flow of fuel in the space inside the filter element FE.

The fuel flowing into the flow path FC4 then passes through the flow path FC5 formed in the upper filter housing UFH, as shown by the arrow AR4 in FIG. Flows into FC6.

The fuel that has flowed into flow path FC6 then flows through a through hole H1 formed in the hollow shaft portion of the upper banjo bolt UBT into flow path FC7 formed in the conduit portion CD of the upper banjo fitting UBJ, as shown by the arrow AR5 in Figure 7. Specifically, the fuel flows into flow path FC7 through the first through hole H1a, flows into flow path FC7 through the second through hole H1b (not visible in Figure 7), flows into flow path FC7 through the third through hole H1c, and then flows into flow path FC7 through the fourth through hole H1d.

Thereafter, the fuel that has entered the flow path FC7 flows from the fuel filter 56 toward the engine 11, as shown by arrow AR6 in FIG.

With the above-mentioned configuration, the fuel filter 56 can prevent a relatively large amount of water from accumulating in the lower space LS even if the fuel flowing into the fuel filter 56 contains moisture. This is because the fuel flows from vertically below to vertically above, making it difficult for the water and fuel to be separated. Specifically, the moisture contained in the fuel flows out of the fuel filter 56 without being separated from the fuel in the fuel filter 56. In other words, a relatively small amount of water is discharged from the fuel filter 56 together with a relatively large amount of fuel. Also, even if a relatively small amount of water accumulates in the lower space LS while the engine 11 is stopped, that is, when no fuel flow is occurring in the fuel filter 56, when the fuel flow is resumed, the water in the lower space LS is agitated by the relatively large amount of fuel and is sent to the engine 11 in a dispersed state in the relatively large amount of fuel. As a result, the fuel filter 56 can prevent a relatively large amount of water accumulated in the lower space LS from flowing into the engine 11 all at once. That is, even if water accumulates in the lower space LS, the fuel filter 56 only allows a relatively small amount of water dispersed in a relatively large amount of fuel to flow into the engine 11, preventing adverse effects on the engine 11. Adverse effects on the engine 11 include, for example, engine stalls.

In the above configuration, the fuel filter 56 is configured so that fuel flows from vertically downward to vertically upward, but it may be configured so that fuel flows from vertically upward to vertically downward. Even in this configuration, the fuel filter 56 can prevent a relatively large amount of water from accumulating in the filter housing FH, and thus can prevent a relatively large amount of water from flowing into the engine 11 all at once.

Next, referring to FIG. 9, another example of the configuration of the fuel filter 56 will be described. FIG. 9 shows another example of the configuration of the fuel filter 56, and corresponds to the lower half of FIG. 7.

The fuel filter 56 shown in FIG. 9 differs from the fuel filter 56 shown in FIG. 7 in that the first port P1, which serves as a lower opening, is formed at the left end of the lower surface of the lower filter housing LFH, in that the first port P1 is formed in the center of the lower surface of the lower filter housing LFH. The fuel filter 56 shown in FIG. 9 is otherwise the same as the fuel filter 56 shown in FIG. 7. The first port P1 may also be formed at the right end of the lower surface of the lower filter housing LFH.

With this configuration, the fuel filter 56 shown in FIG. 9 provides the same effect as the fuel filter 56 shown in FIG. 7. Further, this configuration can increase the degree of freedom in designing the fuel filter 56.

Note that the configuration in which the first port P1 is formed in the center of the lower surface of the lower filter housing LFH as shown in FIG. This has the effect of spreading the fuel flow.

Next, referring to FIG. 10, we will explain another example of the configuration of the fuel filter 56. FIG. 10 shows another example of the configuration of the fuel filter 56, and corresponds to the lower half of FIG. 7.

The fuel filter 56 shown in FIG. 10 differs from the fuel filter 56 shown in FIG. 7 in that the first port P1 as a lower opening is formed at the lower end of the side of the lower filter housing LFH, in that the first port P1 is formed in the center of the lower surface of the lower filter housing LFH. In other respects, the fuel filter 56 shown in FIG. 10 is the same as the fuel filter 56 shown in FIG. 7.

With this configuration, the fuel filter 56 shown in FIG. 10 provides the same effect as the fuel filter 56 shown in FIG. 7.

The fuel filter 56 shown in FIG. 10 is configured so that the height of the lower space LS is higher than the height of the lower space LS in the fuel filter 56 shown in FIG. 7. This is to prevent damage to the filter element FE caused by the fuel flowing in from the first port P1 directly hitting the filter element FE. This configuration has the effect of suppressing pressure loss caused by the fuel filter 56.

As described above, the excavator 100 according to an embodiment of the present invention has a lower traveling body 1, an upper rotating body 3 rotatably mounted on the lower traveling body 1, a fuel tank 19 mounted on the upper rotating body 3, and an engine 11 mounted on the upper rotating body 3, as shown in Figs. 1 and 2, for example. The excavator 100 further has a main filter 45 provided in a pipe 41 as a fuel supply path between the fuel tank 19 and the engine 11, and a fuel filter 56 provided in the pipe 41 between the main filter 45 and the engine 11, as shown in Fig. 4, for example.

The fuel filter 56 has a first port P1 as a lower opening and a second port P2 as an upper opening, and fuel flows into it from one of the first port P1 and the second port P2. , the fuel flows out from the other of the first port P1 and the second port P2. In the example shown in FIG. 7, the fuel filter 56 has a first port P1 as a lower opening and a second port P2 as an upper opening, and fuel flows into the first port P1 and the second port P1. It is configured such that fuel flows out from P2.

One of the upper opening and the lower opening is preferably connected to a space outside the filter element FE in the fuel filter 56, and the other of the upper opening and the lower opening is preferably connected to a space outside the filter element FE in the fuel filter 56. , is connected to a space inside the filter element FE in the fuel filter 56. In the example shown in FIG. 7, the first port P1 as the lower opening is connected to the lower space LS, which is the space outside the filter element FE in the fuel filter 56, and the second port P2 as the upper opening. is connected to a space inside the filter element FE in the fuel filter 56.

With this configuration, the fuel filter 56 can reliably remove foreign matter contained in the fuel while preventing water from accumulating inside the fuel filter 56. Therefore, the fuel filter 56 can reliably prevent fuel containing foreign matter from being supplied to the engine 11.

Fuel filter 56 is desirably configured so that fuel enters through a lower opening and exits through an upper opening.

With this configuration, even if the fuel contains moisture, the fuel filter 56 can prevent the moisture from being separated from the fuel. Therefore, the fuel filter 56 can prevent water from accumulating in the fuel filter 56, and can also prevent a relatively large amount of water from being supplied to the engine 11 at once.

The above describes the preferred embodiments of the present invention in detail. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions can be applied to the above-described embodiments without departing from the scope of the present invention. Furthermore, features described separately can be combined as long as no technical contradiction occurs.

For example, in the above embodiment, a pre-filter 43 is provided between the fuel tank 19 and the main filter 45 in the fuel supply path from the fuel tank 19 to the engine 11, but a circuit configuration without a pre-filter 43 is also possible. In this case, as in the above embodiment, the action of the fuel filter 56 can prevent foreign matter from entering the engine 11 through the part from which the main filter 45 is removed when replacing the main filter 45.

Further, in the above-described embodiment, the banjo joint BJ is fastened to each of the first port P1 and the second port P2 of the fuel filter 56 by the banjo bolt BT, but a threaded elbow joint or the like may be fastened thereto.

1: Lower traveling body 3: Upper rotating body 3a: Monitor 4: Boom 5: Arm 6: Bucket 9: Exhaust pipe 10: Cab 11: Engine 12: Cooling fan 13: Heat exchanger unit 14: Hydraulic pump 15: Piping 16: Water temperature sensor 17: Center frame 17L: Left center frame 17R: Right center frame 19: Fuel tank 20: Storage tank 30: Controller 40: Pump room 40a: Support 40b: Partition plate 40c: Support frame 40H: Notch 41: Piping 42: Shut-off valve 43: Pre-filter 44: Fuel pump 45: Main filter 48: Fuel return pipe 49: Fuel cooler 50: Water separator 52: Water level detector 52a: Detection shaft 52b: Float 52c: Detection unit 52d: Electric cable 56: Fuel filter 57...Gauze filter 63...Air cleaner 64...Intake pipe 100...Shovel 120...Hydraulic oil tank 200...Engine hood AN...Annular portion AP...Maintenance opening BF...Boom foot pin BJ...Banjo joint BT...Banjo bolt CD...Conduit portion CK...Drain cock CS...Side space ER...Engine room FC1-FC7...Flow path FE...Filter element FH...Filter housing FR...Swivel frame H0, H1...Through hole H1a...First through hole H1b...Second through hole H1c...Third through hole H1d...Fourth through hole LBJ...Lower banjo joint LBT...Lower banjo bolt LFH...Lower filter housing LS...Lower space P1...First port P2...Second port Pa...Inlet port Pb...Outlet port RC...Inner peripheral recess RV... Water storage section SP... Space UBJ... Upper banjo joint UBT... Upper banjo bolt UFH... Upper filter housing WS... Washer

Claims (6)

A lower running body;
An upper rotating body rotatably mounted on the lower traveling body;
A fuel tank mounted on the upper rotating body;
An engine mounted on the upper rotating body;
a main filter provided in a fuel supply path between the fuel tank and the engine;
a fuel filter provided in the fuel supply path between the main filter and the engine,
the fuel filter has an upper opening and a lower opening, and is configured so that fuel flows in through one of the upper opening and the lower opening and fuel flows out through the other of the upper opening and the lower opening;
The lower opening is an opening formed in a side surface or a lower surface of a filter housing of the fuel filter, and a member having a hollow shaft portion through which fuel flows is attached to the lower opening,
The lower opening and the hollow shaft portion do not protrude into a space within the fuel filter.
Shovel. One of the upper opening and the lower opening is connected to a space outside a filter element within the fuel filter,
The other of the upper opening and the lower opening is connected to a space inside a filter element in the fuel filter,
the lower opening is formed at an end of the lower surface of the filter housing;
The excavator according to claim 1. The lower opening formed in the side surface of the filter housing is located at a lower position than the filter element within the fuel filter,
Fuel enters through the lower opening and exits through the upper opening.
The excavator according to claim 1 . A lower running body;
An upper rotating body rotatably mounted on the lower traveling body;
A fuel tank mounted on the upper rotating body;
An engine mounted on the upper rotating body;
a main filter provided in a fuel supply path between the fuel tank and the engine;
A fuel filter for a shovel in a shovel comprising:
the fuel supply pipe has an upper opening and a lower opening, and is configured so that fuel flows in through one of the upper opening and the lower opening and fuel flows out through the other of the upper opening and the lower opening;
The lower opening is an opening formed in a side surface or a lower surface of a filter housing of the fuel filter, and a member having a hollow shaft portion through which fuel flows is attached to the lower opening,
The lower opening and the hollow shaft do not protrude into a space defined by the filter housing.
Excavator fuel filter. one of the upper opening and the lower opening is connected to a space within the fuel filter that is outside a filter element;
the other of the upper opening and the lower opening is connected to a space inside a filter element in the fuel filter;
The lower opening is formed at an end of the lower surface of the filter housing.
5. A fuel filter for a shovel according to claim 4. a lower opening formed in a side surface of the filter housing is located at a lower position than a filter element in the fuel filter;
Fuel flows in through the lower opening and flows out through the upper opening.
5. A fuel filter for a shovel according to claim 4 .

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