WO2014115791A1

WO2014115791A1 - Fuel tank for construction machine

Info

Publication number: WO2014115791A1
Application number: PCT/JP2014/051330
Authority: WO
Inventors: 祥隆簗瀬; 寛兼澤
Original assignee: 日立建機株式会社
Priority date: 2013-01-24
Filing date: 2014-01-23
Publication date: 2014-07-31
Also published as: JP2016055652A

Abstract

A top plate (41a) of a tank body (41) for storing a fuel is provided with a check valve (42) in a manner such that the check valve penetrates the top plate and reaches a predetermined height position inside the tank body (41). The periphery of the check valve (42) is covered by a cover member (47) having a bottomed cylindrical shape and extending from the top plate (41a) of the tank body (41). A circulation hole (47a) through which the fuel inside the tank body (41) circulates is provided in the cover member (47). Thus, it is possible to prevent the check valve (42) from opening and closing frequently, even in a state where the liquid surface inside the fuel tank (40) is undulating violently.

Description

Construction machinery fuel tank

The present invention relates to a fuel tank for a construction machine such as a hydraulic excavator, and more particularly to a fuel tank for a construction machine such as a large hydraulic excavator used for open pit mining.

Large and super large hydraulic excavators, which are one of the construction machines for mining (mining), for example, have a traveling body with a height of 2m or more above the ground, and a vehicle with a total height exceeding 7m above the ground, including a rotating body. is there. Fuel supply (fuel supply) to such a large / super large hydraulic excavator is difficult from above because the fuel tank itself is installed on the revolving structure and located at a high place.

Therefore, conventionally, as shown in, for example, Patent Document 1 below, a refueling panel (concentrating panel) that can be moved up and down by a rotating arm is provided on the lower surface of the frame of the revolving structure, and this refueling panel is connected to the fuel tank piping. In addition, at the time of refueling, the operator lowers the refueling panel and connects the fuel hose extending from the tank lorry to the pipe connection portion of the refueling panel to refuel the fuel tank.

At this time, since the refueling operator is working on the ground, the level of the liquid level in the fuel tank cannot be directly recognized, so that the fuel exceeding the maximum capacity (full) of the fuel tank should be supplied. Then, the fuel may overflow from the air blister provided at the upper end of the fuel tank.

For this reason, for example, in Patent Document 2 below, a limit position detection sensor constituted by a proximity switch composed of a pair of electrodes separated by a predetermined interval from the full level in the fuel tank is provided, and the fuel level is full. When both of these electrodes are reached, the two electrodes are immersed in the fuel and become conductive, so that the alarm means is activated to inform the refueling worker on the ground that the fuel tank is full.

Further, as in Patent Document 3 below, the internal pressure of the fuel tank that rises as the fuel level rises is detected, and when this internal pressure reaches a predetermined level, it is determined that the fuel tank is full and the fuel is supplied. A warning light on the panel is lit to indicate that the fuel tank is full, or the fuel pump is automatically stopped to prevent the fuel from overflowing.

That is, in this fuel tank, a breathing port for circulating gas in the tank is formed in order to smoothly put in and out the fuel, and this breathing port is provided with an air breather equipped with an air filter or the like. ing. The air blister is provided with a check valve so as to face a predetermined height position in the fuel tank. When the liquid level reaches the height of the check valve during refueling, the check valve is closed. The internal pressure rises to indicate that the fuel tank is full. In the case of automatic supply, the fuel pump is automatically stopped.

Japanese Patent Laid-Open No. 10-325159 JP 2000-264078 A JP 2005-16332 A

By the way, the fuel tank of the large and super large hydraulic excavator as described above has a large capacity of 5000 liters or more and can be refueled in order to finish the work in a short time. As long as the flow is large. For this reason, the liquid level in the fuel tank is constantly violently rippled during refueling. In such a state, since the liquid level reaches or falls below the check valve of the air breather, the check valve frequently repeats opening and closing.

As a result, even though the tank is not full, the tank internal pressure rises momentarily and the warning light on the refueling panel flashes violently or the movement of the fuel pump becomes unstable. Refueling may not be possible.

Therefore, the present invention has been devised to solve these problems, and the object of the present invention is to provide a new construction machine that can stably supply fuel even when the liquid level in the fuel tank is severely undulated. A fuel tank is provided.

In order to solve the above-mentioned problems, a first invention is a construction machine comprising a check valve provided on a top plate of a tank body where fuel is stored so as to pass through the top plate and face a predetermined height position in the tank body. A fuel tank, the periphery of the check valve being covered with a bottomed cylindrical cover member extending from the top plate of the tank body, and a small-diameter circulation hole (throttle) through which fuel in the tank body flows to the cover member This is a construction machine fuel tank.

According to such a configuration, even when the liquid level in the fuel tank undulates during refueling, the influence on the check valve can be reduced by the cover member covering the periphery of the check valve. As a result, since the check valve can be prevented from frequently opening and closing, fuel can be supplied stably. Further, since the fuel in the fuel tank can flow (in and out) through the flow hole in the cover member, it is possible to ensure an accurate opening / closing operation of the check valve according to the amount of fuel supplied.

A second invention is a fuel tank for a construction machine according to the first invention, wherein the flow hole is formed in a bottom portion of the cover member. According to such a configuration, the fuel in the fuel tank can be reliably circulated into the cover member without being directly affected by the movement of the liquid level. Further, when the liquid level is lowered, the fuel that has flowed into the cover member can be discharged without remaining.

A third invention is a fuel tank for a construction machine according to the first invention, wherein a vent hole communicating with the inside of the tank body is provided near the top plate of the cover member. According to such a configuration, the fuel can smoothly flow (in and out) from the flow hole, and the vent hole is provided in the vicinity of the top plate of the cover member. The possibility of preventing holes can be kept low.

According to a fourth invention, in the first invention, the top plate of the tank main body is provided with a relief valve that opens when the pressure in the tank main body exceeds a predetermined pressure and releases the gas in the tank main body, and the cover The member is a fuel tank for a construction machine that covers the relief valve together with the check valve. According to such a configuration, it is possible to reliably prevent the fuel from reaching the relief valve of the top plate even when the liquid level undulates.

A fifth aspect of the present invention is a fuel tank for a construction machine comprising a check valve so as to penetrate a top plate of a tank main body in which fuel is stored to reach a predetermined height position in the tank main body, A fuel tank for a construction machine, wherein a partition plate is provided in the tank so as to surround the check valve, and a flow hole through which fuel in the tank body flows is provided in the partition plate.

According to such a configuration, even when the liquid level in the fuel tank violently undulates during refueling as in the first aspect of the invention, the partition plate positioned so as to surround the check valve is used for the check valve. The effect can be reduced. As a result, the check valve can be prevented from frequently opening and closing, so that fuel can be supplied stably. Further, since this partition plate allows the fuel in the fuel tank to flow (in / out) through the flow hole, it is possible to ensure an accurate opening / closing operation of the check valve according to the amount of fuel supplied.

According to the present invention, even when the liquid level in the fuel tank violently ripples during refueling, the influence on the check valve can be reduced by the cover member that covers the periphery of the check valve. As a result, the check valve can be prevented from frequently opening and closing, so that fuel can be supplied stably.

1 is an overall side view showing an embodiment of a large hydraulic excavator (construction machine) 100 including a fuel tank 40 according to the present invention. It is a top view showing the structure of the oil supply panel 53 provided in the rotating body 20 bottom part (lower surface) of the large sized hydraulic shovel (construction machine) 100 which concerns on this invention, and its support mechanism. It is a side view showing the structure of the oil supply panel 53 and its support mechanism. It is the panel front view which looked at the oil supply panel 53 from the arrow V direction in FIG. 1 is a circuit diagram conceptually showing an overall configuration of a fuel tank 40 according to the present invention. It is a longitudinal section showing concretely the whole composition of fuel tank 40 concerning the present invention. It is the elements on larger scale which show the A section in FIG. It is a longitudinal cross-sectional view which shows other embodiment of the fuel tank 40 which concerns on this invention. It is a longitudinal cross-sectional view which shows other embodiment of the fuel tank 40 which concerns on this invention. It is a longitudinal cross-sectional view which shows other embodiment of the fuel tank 40 which concerns on this invention. FIG. 6 is a conceptual diagram showing the influence of a wave of a liquid level in a fuel tank 40 that does not include a cover member 47.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows the overall structure of a large excavator 100 having a fuel tank according to the present invention. As shown in the drawing, the large excavator 100 is provided on a traveling body 10 that travels on the ground, a revolving body 20 that is turnably mounted on the top of the traveling body 10, and a front portion of the revolving body 20. The front apparatus 30 is comprised.

The traveling body 10 is provided with driving wheels 12 and driven wheels 13 on the left and right sides of a track frame 11 having a substantially H shape in plan view, and an endless track crawler (crawler) 14 between the driving wheels 12 and the driven wheels 13. The vehicle is run across the ground, and is driven on the ground by driving the driving wheel 12 by a traveling hydraulic motor 15 and rotationally driving the crawler 14.

On the other hand, the swivel body 20 is provided on the swivel frame 21 that forms the foundation lower structure, and is provided behind the cab bed 24 and the cab bed 24 that supports the cab 23, and the cab bed 24 that supports the cab 23. The counterweight 25 for balancing the weight of the fuel tank 40 and the front device 30 is integrally provided. As shown in the figure, the swivel body 20 has a height above the swivel frame 21 that exceeds the height of a human being, for example, about 2 m, and the ground height to the cab 23 has reached about 7 m, for example. . Therefore, a staircase 26 and a passage 27 for reaching the cab 23 from the ground are provided on the side surface of the revolving structure 20.

The revolving body 20 is provided on the traveling body 10 via a revolving wheel 28 disposed at a substantially central portion of the traveling body 10, and a plurality of unillustrated parts provided near the center of the revolving wheel 28. The turning wheel 28 is rotationally driven by a turning hydraulic motor so that it can turn in a horizontal direction with respect to the traveling body 10.

The front device 30 includes a boom 31 extending forward from the revolving unit 20, an arm 32 pivotally supported at the tip of the boom 31, a bucket 33 provided at the tip of the arm 32, and a boom cylinder 34 for driving them. The arm cylinder 35 and the bucket cylinder 36 are used as hydraulic actuators. The actuators are expanded and contracted by hydraulic pressure from a hydraulic pump (not shown) that operates on the engine, and the boom 31, the arm 32, and the bucket 33 are moved to perform various operations such as excavation.

In the large excavator 100 having such a configuration, the fuel supplied to the fuel tank 40, the hydraulic oil that drives a plurality of hydraulic actuators such as the boom cylinder 34 and the traveling hydraulic motor 15, or the engine (not shown) is cooled. Supplying and draining work such as supplying various liquids such as engine oil, cooling water, grease to be supplied to the swivel wheel 28, etc., and draining and replacing old liquids as necessary is necessary. .

The fuel tank 40, the hydraulic oil tank (not shown), the engine, and the like that perform this supply / drainage operation are all provided inside the revolving structure 20, that is, on the revolving frame 21, but in the large-sized hydraulic excavator 100 of the present embodiment, As described above, the height from the ground to the lower surface of the revolving unit 20 is, for example, about 2 m. Therefore, a concentrated panel (oil supply panel) 53 can be moved up and down as shown in FIGS. It is supported and provided.

2 is a top view showing the structure of the concentrated panel 53 and its support mechanism, FIG. 3 is a side view thereof, and FIG. 4 is a front view of the panel as seen from the direction of arrow V in FIG. 2 to 4, reference numeral 21a denotes a lower surface of the revolving frame 21, and a fuel pipe 51 extending from the fuel tank 40 and a plurality of pipes for supplying and discharging liquids such as the above-described hydraulic oil, engine oil, cooling water, and grease. 52, 52... Are routed along the turning frame lower surface 21a. And the edge part of these piping 51 and 52 is connected to the concentration panel 53, respectively.

As shown in FIG. 4, the concentration panel 53 is provided with a piping connection portion 54 for supplying fuel and a plurality of

piping connection portions

55, 55... For other hydraulic oil, engine oil, cooling water, grease, and the like. These

pipe connection portions

54, 55 are connected to detachable hose for supplying or discharging liquid (in FIG. 4, caps 54a, 55a are respectively connected to the

pipe connection portions

54, 55,. The state of wearing is shown). The pipe connecting portion 54 is connected to the fuel pipe 51, and the other

pipe connecting portions

55, 55... Are connected to the

pipes

52, 52. Also, reference numeral 56 in FIG. 4 denotes a warning lamp that lights up when the fuel tank 40 is full during refueling.

The concentration panel 53 configured as described above is supported so as to be movable up and down with respect to the lower surface 21a of the revolving frame via a pair of rotating

arms

59, 59 as shown in FIGS. One end of the pair of rotating arms 59, 59 (the right end in FIGS. 2 and 3) is connected to both ends in the width direction of the concentrated panel 53, and the other end (in FIGS. 2 and 3). The left end portion is rotatably connected to the lower end portions of a pair of

brackets

58 and 58 fixed to a beam 57 provided on the lower surface 21a of the revolving frame.

2 and 3,

reference numerals

60 and 60 are a pair of lifting cylinders provided for driving to lift the centralized panel 53. The

brackets

61 and 61 are connected to the

brackets

61 and 61, respectively, and the other end portions are connected to the upper ends of the

brackets

58 and 58, respectively.

The lifting / lowering cylinder 60 can be operated from the inside of the cab 23. During the supply / drainage operation, the driver extends the lifting / lowering cylinder 60 to rotate the concentration panel 53 in the direction of the arrow in FIG. It is lowered so as to move (this state is indicated by a two-dot chain line in FIG. 3). In other cases, the elevating cylinder 60 is shortened to raise the concentration panel 53 so as to be accommodated in the opening 21b (see FIG. 2) provided in the lower surface 21a of the turning frame.

Thus, at the time of the supply / drainage work, the operator can easily perform the work while standing on the ground by lowering the concentration panel 53. When the turning body 20 turns or travels, the concentration panel 53 is accommodated in the opening 21b so that the concentration panel 53 can be prevented from colliding with the endless track 14 or surrounding rocks and being damaged. It has become.

Since the fuel supply to the fuel tank 40 is performed through the concentration panel 53, the refueling worker on the ground cannot directly see the liquid level of the fuel tank 40, but the fuel tank 40 is full. Then, since the warning light 56 provided on the concentration panel 53 is turned on or changed, the fueling worker on the ground can grasp the full state of the fuel tank 40 by visually checking the lighting state of the warning light 56. It has become.

FIG. 5 is a circuit diagram conceptually showing the overall configuration of the fuel tank 40 according to the present invention. As shown in the figure, this fuel tank 40 has a tank body 41 whose inside is sealed, and supplies (stores) about several thousand liters (for example, 5000 liters or more) of fuel at a time from a tank lorry (not shown). It has enough capacity. That is, in the tank body 41, fuel is pumped up from a tank lorry by a pump or the like, and fuel is supplied from the bottom through the pipe connection portion 54 and the fuel pipe 51 of the concentration panel 53 described above.

The tank body 41 is partitioned by a plate body in the front, rear, left, and right sides, and the top and bottom, and a check valve 42 is provided on a top plate 41a that partitions the upper portion thereof. As will be described in detail later, the check valve 42 is opened when the liquid level L of the fuel F is lower than the lower end height H1 of the check valve 42, and the gas phase G in the tank body 41 (the fuel in the tank body 41). The gas portion above the liquid level) communicates with the outside air to suck and exhaust gas. When the liquid level L of the fuel F is equal to or higher than the lower end height H1 of the check valve 42, the air in the tank body 41 is closed. The phase part G is sealed.

Further, a relief valve 43 is provided in the vicinity of the check valve 42. The relief valve 43 will also be described in detail later, but operates when the pressure of the gas phase portion G sealed by the check valve 42 exceeds a certain value, and allows the gas in the gas phase portion G to escape to the outside. It is designed to avoid damages. These check valve 42 and relief valve 43 are generally referred to as an air blister 44. Note that an air filter 45 is attached to the air blister 44.

6 is a longitudinal sectional view specifically showing the structure of the check valve 42 and the relief valve 43 of the air blizzer 44, and FIG. 7 is a partially enlarged view showing a portion A in FIG. As shown in the figure, first, the check valve 42 is composed of a cylindrical portion 42a that vertically passes through the top plate 41a of the tank body 41 and a ball receiving portion 42b that is provided at the lower portion of the cylindrical portion 42a. Has been.

In the ball receiving portion 42b, a resin sphere B is accommodated so as to be movable up and down. The sphere B has an internal hollow structure, has a specific gravity smaller than that of the fuel, and has a property of floating on the liquid level of the fuel in the tank body 41. In addition, a plurality of openings 42c smaller than the sphere B are provided at the side of the ball receiving portion 42b, and an opening 42d smaller than the sphere B is also formed at one place (or a plurality of places) of the bottom plate. Is provided. Further, an opening 42e is provided in the top plate portion of the ball receiving portion 42b, and the inside of the ball receiving portion 42b and the inside of the cylindrical portion 42a are in communication with each other through the opening 42e.

As shown in the figure, the periphery of the check valve 42 is covered with a bottomed cylindrical cover member 47. The upper end of the cover member 47 is attached to the bottom of the top plate 41a of the tank body 41 by welding or the like, and the bottom (bottom plate) has a small diameter (for example, several centimeters) through which the fuel in the tank body 41a flows. A flow hole (squeezing) 47a is formed. Further, in the vicinity of the top plate 41 a of the cover member 47, a vent hole 47 b communicating with the gas phase part G in the tank body 41 is formed.

When the fuel flows into the cover member 47 from the flow hole (throttle) 47a of the cover member 47 and the liquid level rises and reaches the height (H1) of the ball receiving portion 42b of the check valve 42, the ball The fuel flows into the receiving portion 42b, and the sphere B is lifted up and close to the opening 42e. On the other hand, when the liquid level of the fuel falls below the height (H1) of the ball receiving portion 42b of the check valve 42, the sphere B in the ball receiving portion 42b descends and moves to the bottom thereof, so the opening 42e. Will be open. In this state, the gas in the gas phase portion G in the tank main body 41 flows into the ball receiving portion 42b through the opening 42c of the ball receiving portion 42b and is exhausted out of the tank main body 41 through the cylindrical portion 42a. When the liquid level of the fuel further decreases, air in the atmosphere flows into the ball receiving portion 42b through the cylindrical portion 42a, and flows into the tank main body 41 through the opening 42c. The difference is reduced. Further, an air filter 45 is provided at the upper end of the cylindrical portion 42a so as to filter the gas passing therethrough.

On the other hand, as shown in FIG. 6, the relief valve 43 includes a cylindrical portion 43 a that vertically penetrates the top plate 41 a of the tank body 41, a valve body 43 b provided in a valve seat portion of the cylindrical portion 43 a, and this cylindrical portion. It is comprised from the exit part 43c connected to 43a. The valve body 43b is normally urged in a direction to always sit on the cylinder portion 43a and close it by the spring member 43d. As described above, when the internal pressure of the tank body 41 exceeds a certain value, the valve body 43b The gas in the tank main body 41 is released to the outside away from the cylindrical portion 43a. Further, the outlet 43c of the relief valve 43 and the air filter 45 of the check valve 42 are connected by a communication pipe 46, and the relief valve 43 and the check valve 42 share the outlet 43c serving as a gas intake / exhaust port. It has a structure like this.

Next, the refueling operation to the fuel tank 40 of the large excavator 100 configured as described above and the operation at the time of refueling will be described. The refueling work is performed at the excavation work site when the tank lorry travels to the excavation work site where the large excavator 100 is located. In addition, this refueling work is normally performed once a day. During this refueling operation, the driver or the like lowers the concentration panel 53 by an operation from within the cab 23. Then, the refueling worker connects a refueling hose (not shown) extending from the tank lorry to the pipe connection portion 54 of the concentration panel 53 and activates a pump (not shown) provided in the tank lorry to pump fuel ( Note that the fuel is not limited to the pump, and the fuel can be pumped using, for example, compressed gas). The fuel pumped from the tank lorry is pumped into the fuel tank 40 via the pipe connection portion 54 of the concentration panel 53 and the fuel pipe 51.

In this way, the liquid level in the fuel tank 40 gradually rises. At this time, as shown in FIG. 6, until the liquid level reaches the height H1 of the ball receiving portion 42b of the check valve 42, the check valve 42 communicates the gas phase portion G in the fuel tank 40 with the outside air. Play the role of a blizzard. Then, when the liquid level rises and reaches the height H1 of the ball receiving portion 42b of the check valve 42, the sphere B in the ball receiving portion 42b rises as shown by the broken line in FIG. The gas phase part G and the outside air are shut off to seal the inside of the tank body 41. Thereafter, as the fuel is continuously supplied from the tank lorry and the liquid level in the tank main body 41 rises, the pressure in the gas phase portion G gradually rises.

When the pressure in the gas phase portion G rises and reaches a predetermined pressure, the fuel feed pressure rises and a pressure switch (not shown) provided in the fuel pipe 51 is activated, and a warning lamp 56 provided on the concentration panel 53 is lit. To do. The refueling operator recognizes that the fuel tank 40 is full by visually observing that the warning lamp 56 is turned on, and stops the tank lorry pump to stop the fuel supply. Thereafter, the oil supply hose is removed from the pipe connection portion 54 of the concentration panel 53, and the driver or the like raises the concentration panel 53 by an operation from the inside of the cab 23, thereby completing the oil supply operation.

In such a series of refueling operations, as described above, the fuel tank 40 has a large capacity of 5000 liters or more, so that the refueling is as large as possible in order to finish the work in a short time. It is done at a flow rate. Therefore, as shown in FIG. 11, the liquid level in the tank main body 41 is always greatly rippled during refueling. In the figure, the height H2 indicates the maximum height of the undulating liquid level from the tank bottom (wave peak), and the height H3 indicates the minimum height of the undulating liquid level from the tank bottom (wave valley). ).

When the maximum liquid level height H2 at the position of the check valve 42 exceeds H1 (H2 ≧ H1), the check valve 42 is closed, but refueling is continued. The relief valve 43 is opened, and the gas in the gas phase portion G is released from the relief valve 43 to the outside of the tank body 41. Thereafter, when the height of the liquid level at the position of the check valve 42 reaches the minimum height H3 (H3 <H1), the check valve 42 is opened and the gas in the gas phase portion G is tanked from the check valve 42. It is discharged out of the main body 41. When the check valve 42 is opened, the pressure in the gas phase portion G decreases, so that the relief valve 43 operates to close. Thereafter, when the maximum liquid level height H2 exceeds H1, the check valve 42 is closed and the relief valve 43 is opened. That is, when the liquid level in the tank main body 41 rises and becomes close to the height (H1) of the ball receiving portion 42b of the check valve 42, the check valve 42 and the relief valve 43 alternate due to the ripple phenomenon of the liquid level. Operates frequently to open and close.

Such a phenomenon occurs when the minimum height H3 of the liquid surface exceeds H1 (H3 ≧ H1), and the pump automatically stops until the predetermined time elapses, that is, in the case of automatic refueling. (Until manual refueling until the worker recognizes the full condition). When the maximum liquid level height H2 reaches the height of the relief valve 43 at the moment when the relief valve 43 is opened in this way, a situation occurs in which the fuel in the tank body 41 reaches the relief valve 43.

However, in the fuel tank 40 of the present invention, since the periphery of the check valve 42 is covered with the bottomed cylindrical cover member 47, the liquid level does not greatly swell inside the cover member 47. That is, when the maximum height H2 of the liquid level reaches the bottom of the cover member 47, the fuel flows into the cover member 47 from the flow hole 47a provided at the bottom, but the opening flow hole 47a has a small diameter and is throttled. Therefore, only a small amount of fuel can enter the cover member 47, and a large amount of fuel does not flow into the cover member 47 all at once.

On the other hand, when the liquid level reaches the minimum height H3, the fuel that has flowed into the cover member 47 flows down from the flow hole 47a provided in the bottom portion. Since it plays a role, the amount of spillage is small, and a large amount of fuel does not spill at once. Then, when the fuel in the tank body 41 increases and the liquid level minimum height H3 reaches the position of the flow hole 47a of the cover member 47, the fuel in the cover member 47 does not flow out and enters one side. The liquid level in the cover member 47 is kept at the minimum height H3 or more.

Thus, since the liquid level in the cover member 47 is not affected by the maximum liquid level height H2 around the cover member 47, the liquid level does not greatly swell like the outside, and rises in proportion to the amount of oil supply. .
As a result, the check valve 42 does not frequently open and close, and the phenomenon that the relief valve 43 frequently opens and closes can be prevented. As a result, a situation in which the warning lamp 56 blinks frequently or fuel reaches the relief valve 43 can be avoided in advance.

Further, by providing the cover member 47 with a vent hole 47b communicating with the inside of the tank body 41, the fuel can be smoothly distributed (in and out) from the flow hole 47a. Further, by providing the vent hole 47b in the vicinity of the top plate of the cover member 47, it is possible to prevent fuel from entering the cover member 47 from the vent hole 47b side even when the liquid level is undulated. In the present embodiment, the example in which one flow hole 47a is provided at the bottom of the cover member 47 has been described. However, there may be a plurality of flow holes 47a and not only the bottom of the cover member 47, It may also be provided on the side. In the present embodiment, the chuck valve 42 and the relief valve 43 are connected (integrated) via the communication pipe 46, but they may be configured separately.

Next, FIGS. 8 to 10 show another embodiment of the fuel tank 40 according to the present invention. First, in FIG. 8, not only the check valve 42 but also the relief valve 43 is covered with a cover member 47. With such a configuration, it is possible to reliably prevent a phenomenon in which fuel reaches the relief valve 43 in addition to the same operations and effects as in the above embodiment.

In FIG. 9, a partition plate 48 is provided in the tank body 41 so as to surround the check valve 42, and a circulation hole 48a through which fuel in the tank body 41 flows is provided near the bottom of the partition plate 48. According to such a configuration, even when the liquid level in the tank main body 41 violently undulates during refueling, the influence on the check valve 42 can be reduced by the partition plate 48 as in the above embodiment. . Further, since the partition plate 48 allows the fuel in the tank body 41 to flow (in / out) through the flow hole 48a, it is possible to ensure an accurate opening / closing operation of the check valve 42 according to the amount of fuel supplied. Can do. Further, since the partition plate 48 allows the fuel in the tank body 41 to flow (in / out) through the flow hole 48a, it is possible to ensure an accurate opening / closing operation of the check valve 42 according to the amount of fuel supplied. Can do.

In addition, by forming the vent holes 48b in the partition plate 48, the gas can be smoothly distributed from the vent holes 48b. Further, by providing the vent hole 48b in the vicinity of the top plate 41a, the inflow of fuel from the vent hole 48b can be prevented even when the liquid level is waved. Further, the partition plate 48 may surround the relief valve 43 together with the check valve 42 as in FIG. When the partition plate 48 is provided in the tank body 41 as described above, the fuel pipe 51 is provided on the side (opposite side) opposite to the partition plate 48 as shown in FIG. Of course, the fuel is supplied from.

FIG. 10 shows an example in which a cover member 49 corresponding to the cover member 47 as described above is integrally provided on the check valve 42 side. That is, the influence of the liquid surface fluctuation on the ball receiving portion 42b can be reduced by the cover member 49 positioned so as to cover the ball receiving portion 42b of the check valve 42. As a result, the check valve 42 can be prevented from frequently opening and closing, so that fuel can be supplied stably. In addition, since the cover member 49 allows the fuel and gas in the tank body 41 to flow (in and out) through the flow hole 49a and the vent hole 49b, an accurate ball receiving portion corresponding to the amount of fuel supplied. The opening / closing operation of 42b can be ensured. Furthermore, since it is not necessary to change the structure of the tank body 41 itself, it can be easily applied to an existing fuel tank later.

100 ... Large hydraulic excavator (construction machine)
DESCRIPTION OF SYMBOLS 10 ... Running body 20 ... Revolving body 40 ... Fuel tank 41 ... Tank main body 41a ... Top plate 42 ... Check valve 42a ... Tube part 42b ... Ball receiving part 43 ... Relief valve 44 ... Air blister 45 ...

Air filter

47, 49 ...

Cover Member

47a, 48a, 49a ... distribution hole (squeezing)
47b, 48b, 49b ... vent hole 48 ... partition plate 51 ... fuel piping 53 ... concentrating panel (oil supply panel)
B ... Sphere F ... Fuel G ... Gas phase H1 ... Ball receiver 42b height H2 ... Maximum wave height H3 ... Minimum wave height

Claims

A fuel tank for a construction machine having a check valve so as to pass through the top plate of the tank body in which fuel is stored and face a predetermined height position in the tank body,
A fuel tank for a construction machine, wherein the periphery of the check valve is covered with a bottomed cylindrical cover member extending from the top plate of the tank main body, and a circulation hole through which fuel in the tank main body flows is provided in the cover member.
In the fuel tank of the construction machine according to claim 1,
A fuel tank for a construction machine, wherein the flow hole is formed in the bottom of the cover member.
In the fuel tank of the construction machine according to claim 1,
A fuel tank for a construction machine, wherein a vent hole communicating with the inside of the tank body is provided near the top plate of the cover member.
In the fuel tank of the construction machine according to claim 1,
The top plate of the tank body is provided with a relief valve that opens when the pressure in the tank body exceeds a predetermined pressure and allows the gas in the tank body to escape,
The cover member is a fuel tank for a construction machine that covers the relief valve together with the check valve.
A fuel tank for a construction machine having a check valve so as to pass through the top plate of the tank body in which fuel is stored and face a predetermined height position in the tank body,
A fuel tank for a construction machine, wherein a partition plate is provided in the tank body so as to surround the check valve, and a flow hole through which fuel in the tank body flows is provided in the partition plate.