Shovel

Abstract

To provide a shovel allowing intrusion of air to a fuel return piping to be suppressed.SOLUTION: A shovel of an embodiment of the present invention comprises a super structure, a fuel tank arranged in the super structure, a fuel supply port penetratingly arranged in a bottom part of the fuel tank, and a fuel return port penetratingly arranged in the bottom part, wherein the fuel return port is arranged at a distance equal to 100 mm or more apart from the fuel supply port.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This disclosure relates to an excavator.

Background Art

[0002] An excavator is known in which a fuel supply pipe is arranged below a fuel tank and a fuel return pipe is arranged above the fuel tank (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the fuel return pipe is arranged above the fuel tank, air may be mixed into the fuel return pipe, and fuel mixed with air may be sent to the engine through the fuel supply pipe in some cases.

[0005] Therefore, it is desirable to provide an excavator capable of suppressing air from being mixed into the fuel return pipe.

Means for Solving the Problems

[0006] An excavator according to an embodiment of the present invention includes an upper swing body, a pump chamber provided in the upper swing body, a fuel tank provided in the upper swing body, a fuel supply port provided through the bottom of the fuel tank, a fuel return port provided through the bottom, and a fuel supply pipe connecting the fuel supply port and the engine, and the fuel return port is provided at a distance of 100 mm or more from the fuel supply port On the right side in the left-right direction of the upper rotating body and is provided, and the fuel supply pipe is routed from the lower part of the fuel tank through the right side part of the upper swing body to the pump chamber without passing through the central part in the left-right direction of the upper swing body The fuel supply piping is provided passing through a part of the slewing frame of the upper slewing body, the slewing frame has a beam member that supports the hydraulic oil tank, the fuel supply piping is provided passing through the beam member, the fuel tank is located in front of the hydraulic oil tank, the pump room is located behind the hydraulic oil tank, and the fuel supply piping is routed to the pump room through the bottom of the hydraulic oil tank. . [Effects of the Invention]

[0007] The above means provides a shovel that can suppress the entry of air into the fuel return pipe. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view showing an example of an excavator. [Figure 2] This is a schematic plan view showing the upper rotating body of the shovel. [Figure 3] This is a schematic perspective view showing the right rear of the upper rotating body of the shovel. [Figure 4] This is a circuit diagram showing an example of a fuel supply system for an excavator. [Figure 5] This is a close-up view of the bottom of the shovel's fuel tank. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings. In each drawing, the same reference numerals are used for the same components, and redundant explanations are omitted.

[0010] First, the basic configuration of the excavator according to this embodiment will be explained with reference to Figures 1 to 3. Hereinafter, the direction in which the boom 4 is attached when viewed from the center of the upper slewing body 2, that is, the direction in which the boom 4 extends relative to the upper slewing body 2, will be referred to as "front," and the opposite direction will be referred to as "rear."

[0011] Figure 1 is a side view showing an example of a shovel according to this embodiment.

[0012] The excavator according to this embodiment comprises a lower traveling body 1, an upper rotating body 2, a cab 3, a boom 4, an arm 5, and a bucket 6.

[0013] The upper revolving body 2 is mounted on the lower traveling body 1 via a turning mechanism (not shown). A cab 3 is provided at the front left side of the upper revolving body 2. One end of a boom 4 is pivotally attached to the center of the front part of the upper revolving body 2 so as to be able to pitch. An arm 5 is attached to the tip of the boom 4 so as to be able to rotate vertically. A bucket 6, which is an end attachment, is attached to the tip of the arm 5 so as to be able to rotate vertically.

[0014] In addition, instead of the bucket 6 which is an excavation attachment, an end attachment such as a breaker or a crusher may be attached to the tip of the arm 5.

[0015] At the rear part of the upper revolving body 2, a diesel engine (hereinafter simply referred to as "engine") 8 (see FIG. 2) and components associated with the engine 8 (hereinafter referred to as "associated components") are mounted, and an engine hood 200 is attached so as to cover the engine 8 and the associated components from above.

[0016] FIG. 2 is a plan view schematically showing the upper revolving body 2.

[0017] An engine room 7 for accommodating the engine 8 and associated components etc. is formed at the rear part of the upper revolving body 2.

[0018] Although the upper part of the engine room 7 is covered by the engine hood 200 as described above, in FIG. 2, in order to show the inside of the engine room 7, a state where the engine hood 200 is removed is shown.

[0019] The engine 8 is mounted at the center of the engine room 7 (that is, the center of the rear part of the upper revolving body 2). Also, near the engine 8, for example, at the upper part on the right side of the engine room 7, a silencer (muffler), an SCR (Selective Catalytic Reduction) system which is an exhaust gas treatment device (not shown), etc. are arranged. Specifically, an exhaust pipe 9 for discharging exhaust gas to the outside is connected to the engine 8, and the exhaust gas treatment device etc. are connected to the end part on the downstream side of the exhaust pipe 9.

[0020] On the swing frame 14 (see FIG. 3) of the upper swing body 2, a pair of central frames 17 (17L, 17R) that longitudinally cut through the front and rear are provided, and the engine 8 is mounted via a mounting bar or the like on brackets (not shown) attached to the central frames 17L, 17R. Further, below the engine 8 in the upper swing body 2, that is, on the swing frame 14 (floor portion) below the engine 8, a maintenance opening 7a (an example of an opening) is provided. An operator can perform oil change work or the like on the engine 8 through the maintenance opening 7a.

[0021] In addition, FIG. 2 shows the inside of the pump chamber 40 provided below the exhaust gas treatment device (SCR system and / or DPF (Diesel Particulate Filter), etc.) with the exhaust gas treatment device removed. Further, as shown in FIG. 2, the central frames 17L, 17R support the boom 4 at their front ends. Specifically, the boom 4 is sandwiched between the front end of the central frame 17R and the front end of the central frame 17L, and is supported by a boom foot pin 100 that penetrates the central frame 17R, the boom 4, and the central frame 17L so as to be rotatable up and down.

[0022] On the left side of the engine room 7 (that is, the left rear part of the upper swing body 2), a cooling fan 12 and a heat exchanger unit 13 including a radiator or the like are mounted. Specifically, a cooling fan 12 driven by the power of the engine 8 is provided at the left end of the engine 8 in the engine room 7, and a heat exchanger unit 13 is mounted to the left of the cooling fan 12. <00001​​​​​​​​​ A pump room 40 is located on the right side of the engine room 7 (i.e., the right rear of the upper slewing body 2). The right rear of the upper slewing body 2, including the pump room 40, will be described below with further reference to Figure 3.

[0026] Figure 3 is a schematic perspective view showing the right rear of the upper slewing body 2. Note that Figure 3 shows the pump room 40 with an access door (an example of a cover) to the pump room 40, located on the right rear side of the upper slewing body 2 (house section), in an open state, in order to illustrate the interior of the pump room 40. Also, Figure 3 shows the beam members 14A and 14B with the hydraulic oil tanks 120 installed on them removed, in order to illustrate the beam members 14A and 14B.

[0027] As shown in Figures 2 and 3, the pump chamber 40 is equipped with a hydraulic pump 66 for circulating the hydraulic fluid in the excavator's hydraulic system, which is driven by the engine 8. Specifically, the hydraulic pump 66 is connected to the right end of the engine 8 with its drive shaft coaxial with the engine 8's crankshaft, and is inserted through a notch (not shown) provided in the partition plate 40b, so that most of it is located inside the pump chamber 40.

[0028] Furthermore, the pump chamber 40 houses various components of the fuel supply system for supplying fuel to the engine 8. Specifically, a pre-filter 43, a fuel pump 44, a main filter 45, and fuel supply piping 41 connecting them are located within the pump chamber 40. More specifically, the fuel supply piping 41 extending from the fuel tank 19 to the engine 8 passes through the pump chamber 40, and the pre-filter 43, fuel pump 44, main filter 45, etc. are installed along the fuel supply piping 41 within the pump chamber 40. In addition, a fuel filter 56 is installed in the portion of the fuel supply piping 41 that extends from the pump chamber 40 and connects to the engine 8.

[0029] The fuel supply pipe 41 is connected at one end to a fuel supply port P1 located at the bottom of the fuel tank 19, and at the other end to the engine 8. The fuel supply pipe 41 is routed from the bottom of the fuel tank 19 to the pump room 40, passing through the right side of the upper slewing body 2 without passing through the central part of the upper slewing body 2 in the left-right direction. This shortens the length of the fuel supply pipe 41 and reduces costs. The fuel supply pipe 41 is routed through a portion of the slewing frame 14. Specifically, the slewing frame 14 has beam members 14A and 14B that support the hydraulic oil tank 120, and the fuel supply pipe 41 is routed from the bottom of the fuel tank 19 through the beam members 14A and 14B to the pump room 40.

[0030] Furthermore, support columns 40a are positioned at the four corners of the pump room 40, erected from the slewing frame 14 (floor section) of the upper slewing body 2. In addition, a partition plate 40b is provided in the pump room 40, connecting the two of the four support columns 40a that are adjacent to the engine 8 (towards the center of the engine room 7). As described above, the partition plate 40b is provided with a notch through which the hydraulic pump 66 passes.

[0031] As shown in Figure 3, the pre-filter 43, fuel pump 44, and main filter 45 are positioned in a visible location in the pump chamber 40 by opening the access door. This allows workers to easily perform maintenance such as replacing the pre-filter 43 and main filter 45. Alternatively, the pre-filter 43, fuel pump 44, and main filter 45 may be attached, for example, to a support frame 40c erected on two support columns 40a at the rear of the pump chamber 40.

[0032] Furthermore, the fuel filter 56 is located to the left of the pump chamber 40 in the engine room 7 (behind the partition plate 40b in Figure 3), below the engine 8, that is, below the crankshaft of the engine 8. The fuel filter 56 is located at the back of the pump chamber 40, that is, behind the notch in the partition plate 40b. Normally, the worker's viewpoint is at approximately the height where the hydraulic pump 66 is located, so even if the access door to the pump chamber 40 is opened, the partition plate 40b obstructs the view of the fuel filter 56 from the worker's relatively high viewpoint. On the other hand, the fuel filter 56 is located in a position accessible to the worker from below the upper slewing body 2 (slewing frame 14) through the maintenance opening 7a. The fuel filter 56 may be attached directly or indirectly via brackets to the structure of the upper slewing body 2, such as the central frame 17L. This allows the fuel supply system, including the fuel filter 56, and the engine 8 to be mounted separately when performing mounting work on various parts onto the upper slewing body 2.

[0033] Returning to Figure 2, an air cleaner 63 (air filter) is positioned in front of the heat exchanger unit 13, which is located at the front of the engine compartment 7, specifically on the left side of the engine compartment 7. The air cleaner 63 is connected to the engine 8 via an intake pipe 64. As a result, air filtered by the air cleaner 63 is supplied to the engine 8 through the intake pipe 64.

[0034] The cab 3 is located in front of the air cleaner 63, that is, on the left front side of the upper rotating body 2. The cab 3 is provided with a driver's seat (not shown), and a monitor 3a, for example, consisting of an LCD display, is provided in front of the driver's seat inside the cab 3.

[0035] Monitor 3a displays various information, such as the operating status of the shovel and the operating status of each part, in response to display signals from the controller 30. The operator operates the shovel while checking the various information displayed on Monitor 3a.

[0036] The controller 30 is a control device that controls the operation of the entire excavator and its various parts, and is mounted, for example, inside the cab 3. The controller 30 is mainly composed of a computer, for example, a CPU as a processing unit and internal memory such as ROM and RAM.

[0037] A hydraulic oil tank 120 for storing hydraulic fluid used in the hydraulic system is located in front of the engine room 7, specifically in front of the pump room 40 which is located on the right side of the engine room 7.

[0038] Furthermore, a fuel tank 19 for storing engine 8 fuel (hereinafter simply referred to as "fuel") such as diesel fuel is positioned in front of the hydraulic oil tank 120. The fuel stored in the fuel tank 19 is supplied to the engine 8 via the fuel supply pipe 41.

[0039] A storage tank 20 may be located in front of the fuel tank 19 to store the treatment agent (for example, an aqueous urea solution as a liquid reducing agent) used by the exhaust gas treatment device described above. The treatment agent stored in the storage tank 20 is supplied to the exhaust gas treatment device (not shown) via a treatment agent supply pipe (not shown).

[0040] Next, with reference to Figure 4, the specific configuration of the fuel supply system, including the fuel filter 56, will be described. Figure 4 is a circuit diagram showing an example of a fuel supply system.

[0041] In this embodiment, the fuel supply system of the excavator supplies fuel stored in the fuel tank 19 to the engine 8, for example, by electrically driven fuel pump 44.

[0042] Specifically, when the fuel pump 44 is driven, the fuel in the fuel tank 19 flows through the fuel supply pipe 41 and into the pre-filter 43.

[0043] Furthermore, a shut-off valve 42 is provided in the fuel supply pipe 41 between the fuel tank 19 and the pre-filter 43. The shut-off valve 42 is normally open, allowing fuel to pass through the shut-off valve 42.

[0044] The fuel that flows into the pre-filter 43 is filtered to remove relatively large debris and other foreign matter. The pre-filter 43 is also equipped with a water separator 50, which includes a water level detection device 52. The water separator 50 separates the water contained in the fuel, and the amount of separated water is detected as the water level by the water level detection device 52.

[0045] The fuel that has passed through the pre-filter 43 flows through the fuel supply pipe 41, is drawn into the fuel pump 44, and is discharged from the fuel pump 44. The fuel discharged from the fuel pump 44 flows through the fuel supply pipe 41 and flows into the main filter 45.

[0046] The fuel that flows into the main filter 45 is filtered, and relatively fine debris and other foreign matter are further removed. The fuel that has passed through the main filter 45 flows through the fuel supply pipe 41 and flows into the fuel filter 56.

[0047] The fuel filter 56, like the pre-filter 43 and the main filter 45, has the function of removing (filtering) foreign matter such as dirt contained in the fuel. The fuel filter 56 is, for example, a filter with a mesh size equivalent to or coarser than the main filter 45. As described above, the pre-filter 43 removes relatively large dirt and other debris, and the main filter 45 removes relatively fine dirt and other debris, so normally the fuel flowing into the fuel filter 56 contains almost no foreign matter such as dirt that the fuel filter 56 should filter. On the other hand, when the main filter 45 is replaced, there is a possibility that foreign matter such as dirt may enter the fuel supply system (fuel supply piping 41) from the part where the main filter 45 was removed. Therefore, by positioning the fuel filter 56 downstream of the main filter 45 in the fuel supply system, dirt and other debris that have entered the fuel supply piping 41 from the part where the main filter 45 was removed can be removed (filtered) before they enter the engine 8.

[0048] As mentioned above, since the pre-filter 43 and main filter 45 usually remove most of the debris from the fuel, the fuel filter 56 does not need to be replaced, or it needs to be replaced much less frequently than the pre-filter 43 and main filter 45.

[0049] The fuel that has passed through the fuel filter 56 is supplied to the engine 8.

[0050] Fuel supplied to engine 8 is injected into the cylinders of engine 8 by a fuel injector (not shown). Fuel that is not injected into the cylinders of engine 8 flows through the fuel return pipe 48 and is returned to the fuel tank 19.

[0051] The fuel return pipe 48 is connected at one end to the engine 8 and at the other end to a fuel return port P2 located at the bottom of the fuel tank 19. The fuel return pipe 48 is routed from the engine 8 through the central part of the upper slewing body 2 in the left-right direction to the bottom of the fuel tank 19. More specifically, the fuel return pipe 48 is routed along the counterweight at the rear of the upper slewing body 2. The fuel return pipe 48 is also routed along the central frame 17R between the pump chamber 40 and the fuel tank 19. The fuel return pipe 48 may also be routed through a portion of the slewing frame 14. A fuel cooler 49 is provided in the fuel return pipe 48, and the fuel cooler 49 lowers the temperature of the fuel returning to the fuel tank 19. The fuel cooler 49 is located upstream of the cooling fan 12.

[0052] Thus, in this example, a fuel filter 56 is provided between the main filter 45 and the engine 8 in the fuel supply path (fuel supply pipe 41). This prevents debris and other contaminants from entering the engine 8 from the area where the main filter 45 was removed when the main filter 45 is replaced.

[0053] Furthermore, as described above, the fuel filter 56 is positioned in a location that is not visible even when the access door to the pump room 40 is opened. Therefore, it is possible to prevent situations in which an operator mistakenly replaces the fuel filter 56 when replacing the main filter 45 in the pump room 40.

[0054] Furthermore, as described above, the fuel filter 56 is accessible from the maintenance opening 7a at the bottom of the engine 8, so if replacement is absolutely necessary, a worker can perform the replacement work through the maintenance opening 7a.

[0055] Next, with reference to Figure 5, an example of the positional relationship between the fuel supply port P1 and the fuel return port P2 connected to the fuel tank 19 will be described. Figure 5 is an enlarged view of the lower part of the fuel tank 19 of the excavator, showing the cross-section as seen by the VV line in Figure 2.

[0056] The fuel tank 19 is fastened to the slewing frame 14 (see Figure 3) with bolts BT1. The bottom 19a of the fuel tank 19 is provided with a fuel supply port P1, a fuel return port P2, and a fuel discharge port P3.

[0057] The fuel supply port P1 is provided by penetrating the bottom 19a of the fuel tank 19. Specifically, a flange FR1 is welded to the bottom 19a of the fuel tank 19, and the fuel supply port P1 is provided by fastening a flange FR2 through which the fuel supply port P1 is inserted to the flange FR1 with bolts BT2, thereby penetrating the bottom 19a of the fuel tank 19. The fuel supply port P1 is a port for supplying fuel from the fuel tank 19 to the engine 8, and is, for example, an L-shaped pipe. The upper end of the fuel supply port P1 communicates with the inside of the fuel tank 19, and the lower end is bent in an L-shape toward the outside of the upper rotating body 2 and is located outside the fuel tank 19. A fuel supply pipe 41 is connected to the lower end of the fuel supply port P1.

[0058] The fuel return port P2 is provided by penetrating the bottom 19a of the fuel tank 19. Specifically, the fuel return port P2 is attached to the bottom 19a of the fuel tank 19 without using flanges FR1 and FR2. However, the fuel return port P2 may also be attached to the bottom 19a of the fuel tank 19 via flanges FR1 and FR2. The fuel return port P2 is a port for returning fuel that was not injected into the cylinders of the engine 8 back into the fuel tank 19, and is, for example, an L-shaped pipe. The upper end of the fuel return port P2 communicates with the inside of the fuel tank 19, and the lower end is bent in an L-shape toward the inside of the upper rotating body 2 and located outside the fuel tank 19. A fuel return pipe 48 is connected to the lower end of the fuel return port P2. In this way, since the fuel return pipe 48 is connected to the fuel return port P2 located below the fuel tank 19, the inside of the fuel return pipe 48 is always filled with fuel. This suppresses the mixing of air into the fuel tank 19. As a result, the supply of fuel mixed with air to the engine 8 is suppressed, thus preventing engine starting problems and damage to engine components. In addition, fuel degradation (e.g., oxidation) caused by contact with air is suppressed, thus preventing clogging of the fuel injection system and stickiness in the fuel supply pipe 41. As a result, a decrease in engine output can be suppressed.

[0059] The central axis C2 of the vertically extending portion of the fuel return port P2 is set at a distance of 100 mm or more, preferably 120 mm or more, from the central axis C1 of the vertically extending portion of the fuel supply port P1. This prevents the high-temperature fuel returned from the fuel return port P2 to the fuel tank 19 from being immediately sent to the fuel supply port P1 within the fuel tank 19. As a result, damage to the engine caused by high-temperature fuel being sent to the engine 8 can be prevented. The fuel return port P2 communicates with the inside of the fuel tank 19 at a higher position than the fuel supply port P1, for example. Specifically, the upper end position T2 of the fuel return port P2 is set to be higher than the upper end position T1 of the fuel supply port P1.

[0060] The fuel discharge port P3 is provided through the bottom 19a of the fuel tank 19. Specifically, the fuel discharge port P3 is inserted through flange FR2, and by fastening flange FR2 to flange FR1 with bolt BT2, it is provided through the bottom 19a of the fuel tank 19. That is, the fuel discharge port P3 is attached to the bottom 19a of the fuel tank 19 via the same flange FR2 as the fuel supply port P1. The fuel discharge port P3 is a port for discharging fuel from inside the fuel tank 19, and is, for example, a cock.

[0061] Preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the embodiments described above. Various modifications, substitutions, etc., can be applied to the embodiments described above without departing from the scope of the present invention. Furthermore, features described separately can be combined as long as no technical inconsistencies arise. [Explanation of Symbols]

[0062] 1. Lower running body 2. Upper rotating body 3 Cab 3a Monitor 4 Boom 5 Arms 6 buckets 7. Engine Room 7a Maintenance opening 8 Diesel engine 9 Exhaust pipe 12 Cooling Fans 13 Heat exchanger unit 14. Swivel Frame 14A Beam Member 14B Beam Member 15 Cooling water piping 16. Water temperature sensor 17, 17L, 17R Central Frame 19 Fuel tank 19a bottom 20 storage tanks 30 controllers 40 Pump Room 40a post 40b board 40c support frame 41 Fuel supply 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 detection device 56 Fuel filter 63 Air Cleaner 64 Intake pipe 66 Hydraulic pump 100 Boom Foot Pins 120 Hydraulic oil tank 200 Engine Hood P1 Fuel supply port P2 Fuel return port P3 Fuel Exhaust Port T1 top position T2 top position

Claims

1. Upper rotating body and The pump chamber provided in the upper rotating body, A fuel tank provided on the upper rotating body, A fuel supply port is provided that penetrates the bottom of the fuel tank, A fuel return port is provided that penetrates the bottom, A fuel supply pipe connecting the fuel supply port and the engine, It has, The fuel return port is located on the right side in the left-right direction of the upper rotating body, at a distance of 100 mm or more from the fuel supply port. The fuel supply piping is routed from the bottom of the fuel tank to the pump chamber, passing through the right side of the upper rotating body without passing through the central part of the upper rotating body in the left-right direction. The fuel supply piping is provided passing through a part of the slewing frame of the upper slewing body, The aforementioned slewing frame has a beam member that supports the hydraulic oil tank, The fuel supply piping is provided penetrating the beam member, The fuel tank is positioned in front of the hydraulic oil tank. The pump chamber is located behind the hydraulic oil tank. The fuel supply piping is routed through the lower part of the hydraulic oil tank to the pump room. Shovel.

2. The fuel return port communicates with the inside of the fuel tank at a higher position than the fuel supply port. The shovel according to claim 1.

3. The fuel supply port is an L-shaped pipe whose upper end communicates with the inside of the fuel tank, and whose lower end is bent in an L-shape toward the outside of the upper rotating body and located outside the fuel tank. The fuel return port is an L-shaped pipe whose upper end communicates with the inside of the fuel tank, and whose lower end is bent in an L-shape toward the inside of the upper rotating body and located outside the fuel tank. The shovel according to claim 1 or 2.

4. It has a fuel discharge port that penetrates the bottom, The fuel supply port and the fuel discharge port are attached to the bottom via the same flange. The fuel return port is attached to the bottom without the flange, A shovel according to any one of claims 1 to 3.

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