Work vehicle

Abstract

To prevent occurrence of damage, such as breakage of a tank housing, caused by increase of an inner pressure in a fuel tank when a fuel is supplied to the fuel tank by an oil feed pump mounted on a vehicle body in a state that a cap is attached to an oil filler port.SOLUTION: A work vehicle 1 according to the invention includes: a fuel tank 30 having an oil filler port 32 and configured to store a fuel; an oil feed passage 62 which is connected to the fuel tank 30 separately from the oil filler port 32; an oil feed pump provided in the middle of a path of the oil feed passage 62; an exhaust passage 72 connected to the fuel tank 30; and an on-off valve 74 which is provided in the middle of a path of the exhaust passage 72.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a work vehicle equipped with a hydraulically operated working device. [Background technology]

[0002] Conventionally known examples of working vehicles include hydraulic excavators and track loaders, which are equipped with a lower body to which crawlers or tires for traveling are attached, an upper body disposed on the lower body, and a working device attached to the lower body or upper body and operated by hydraulic pressure (i.e., hydraulic oil at a predetermined pressure).

[0003] The above-mentioned work vehicle is equipped with a hydraulic pump that generates hydraulic pressure and a drive source that drives the hydraulic pump. For example, a configuration in which an engine (such as a diesel engine) is used as the drive source is widespread, and a fuel tank that stores fuel for the engine is mounted on the vehicle body.

[0004] Here, a work vehicle is known that has a fuel hose and a fuel pump mounted on the vehicle body for refilling fuel into the fuel tank, and is configured to easily refuel even in locations where refueling facilities are not available by inserting the fuel hose into a drum or the like containing fuel and sucking up the fuel using the fuel pump (Patent Document 1: See JP 2020-045625 A). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-045625 A Summary of the Invention [Problem to be solved by the invention]

[0006] Recently, there has been an increase in the number of fuel tanks for work vehicles that are fitted with a cap with an intake and exhaust valve conforming to the EN standard (European Norm: EU unified standard). However, caps conforming to this standard have a high level of sealing to strengthen the prevention of fuel leakage in the event of a fall. Therefore, when the fuel tank is replenished with fuel using the vehicle-mounted fuel pump with the cap attached to the fuel tank, the internal pressure of the fuel tank increases, which may cause damage such as the rupture of the tank casing. [Means for solving the problem]

[0007] The present invention has been made in consideration of the above circumstances, and has an object to provide a work vehicle that can prevent damage such as rupture of the tank casing caused by an increase in internal pressure in the fuel tank when fuel is replenished into the fuel tank using a fuel pump mounted on the vehicle with a highly airtight cap attached to the fuel filler port.

[0008] The present invention solves the above problems by the solution means described below as one embodiment.

[0009] A work vehicle in one embodiment is equipped with a fuel tank having a fuel filler port for storing fuel, a fuel supply line connected to the fuel tank separately from the fuel filler port, a fuel pump provided midway through the fuel filler line, an exhaust line connected to the fuel tank, and an opening / closing valve provided midway through the exhaust line.

[0010] According to the above-mentioned configuration, a structure can be realized in which an exhaust passage and an on-off valve are provided in the fuel tank, and the on-off valve is opened when the fuel supply pump is driven to exhaust the air inside the fuel tank, thereby preventing an increase in the internal pressure of the fuel tank.

[0011] It is also preferable that an electromagnetically driven on-off valve is used as the on-off valve, and that the system further comprises a control mechanism for turning on and off the fuel supply pump and the on-off valve, the control mechanism performing control so that the on-off valve is opened when the fuel supply pump is on, and the on-off valve is closed when the fuel supply pump is off.

[0012] It is also preferable that the exhaust passage is connected to the center of the upper surface of the fuel tank and is disposed so as to pass under an upper cover attached to the upper surface.

[0013] It is also preferable that a cap with an intake and exhaust valve is removably provided at the tip of the fuel filler neck, and that the control mechanism is configured to control the fuel filler pump to be turned on and the opening and closing valve to be opened when the cap is attached to the fuel filler neck. Effect of the Invention

[0014] According to the work vehicle of one embodiment, when the fuel tank is replenished with fuel by the vehicle-mounted fuel pump with a tightly sealed cap attached to the fuel filler opening, the air inside the fuel tank can be discharged. This makes it possible to prevent the internal pressure of the fuel tank from increasing, thereby preventing damage caused by this to the tank casing. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing an example of a work vehicle according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing an example of a vehicle body (upper body) of the work vehicle of FIG. [Diagram 3] FIG. 3 is a perspective view showing an example of a fuel tank and peripheral equipment of the work vehicle of FIG. [Figure 4] FIG. 4 is an enlarged view of the fuel tank and peripheral equipment of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic diagram (perspective view from above the right front) showing an example of a work vehicle 1 according to this embodiment. For convenience of explanation, arrows may be used in the drawings to indicate up / down, left / right, and front / rear directions. In addition, in all drawings for explaining the embodiment, members having the same function are given the same reference numerals, and repeated explanations thereof may be omitted.

[0017] First, a description will be given of the overall configuration of the work vehicle 1. A hydraulic excavator will be taken as an example of the work vehicle 1. However, the work vehicle 1 is not limited to a hydraulic excavator.

[0018] As shown in FIG. 1, a work vehicle 1 includes a vehicle body including a lower body 2 and an upper body 3 disposed on the lower body 2 (note that the lower body 2 and the upper body 3 may be integrally configured).

[0019] The work vehicle 1 is equipped with working devices 12, 14 that are attached to the lower body 2 and upper body 3 and are operated by hydraulic pressure (hydraulic oil at a specified pressure). The lower body 2 is equipped with a traveling device 10 that drives the vehicle. The upper body 3 is equipped with a driver's cab 16 at the front where an operator sits and where various operating devices are provided to operate the vehicle for traveling and work.

[0020] An example of the traveling device 10 includes a pair of left and right crawlers 26. However, the traveling device 10 is not limited to the crawlers 26, and may include tires (not shown) instead of the crawlers 26. The crawlers 26 are driven by a hydraulic motor 28 for traveling.

[0021] An example of the working device 12 includes a blade 40. The blade 40 is attached to the lower body 2 so as to be swingable up and down (including forward and backward). The blade 40 is driven by a hydraulic cylinder (blade cylinder) 50. However, the blade 40 is not limited to the above configuration.

[0022] Examples of the working device 14 include a boom 42, an arm 44, and a detachable attachment 46. Note that, in Fig. 1, a state in which a split boom (two-piece boom) is attached as the boom 42 is illustrated, but this is not limited thereto. Also, a state in which a bucket is attached as the attachment 46 is illustrated, but this is not limited thereto.

[0023] In a specific configuration, the boom 42 is attached to the upper body 3 so as to be swingable up and down (including front and rear components) (note that, as another example, a configuration (not shown) in which a boom bracket is provided between the upper body 3 and the boom 42 may be used). The arm 44 is attached to the boom 42 so as to be swingable up and down (including front and rear components). The attachment 46 is attached to the arm 44 so as to be swingable up and down (including front and rear components). The boom 42 is driven by a hydraulic cylinder (boom cylinder) 52. The arm 44 is driven by a hydraulic cylinder (arm cylinder) 54. The attachment 46 is driven by a hydraulic cylinder (bucket cylinder) 56. However, the configuration is not limited to the above.

[0024] The drive mechanism for driving the traveling hydraulic motor 28 and each hydraulic cylinder is composed of, for example, a hydraulic pump (main hydraulic pump, etc.) driven by the drive source 18, a control valve, etc. An operator operates a predetermined operating device to actuate the control valve, and control is performed to supply hydraulic oil at a predetermined pressure delivered from the hydraulic pump to the traveling hydraulic motor 28 and each hydraulic cylinder. This allows the traveling device 10 to travel, and the working devices 12, 14 to work. One or more hydraulic pumps that constitute the drive mechanism are provided depending on the configuration and load of the working devices 12, 14 and the traveling device 10.

[0025] The work vehicle 1 is also provided with an engine (specific examples include a diesel engine, a gasoline engine, etc.) that burns fuel (specific examples include diesel, gasoline, etc.) as the drive source 18. Note that the work vehicle 1 may also be configured to include an electric motor together with the engine (a so-called hybrid system) (not shown).

[0026] Here, in the work vehicle 1, a fuel tank 30 for storing the fuel to be supplied to the engine 18 is mounted in the equipment room 20 of the upper body 3 (FIG. 3 shows the state with various covers removed, and FIG. 4 is an enlarged view thereof). As an example, the fuel tank 30 is formed in a hollow, generally rectangular parallelepiped shape using a metal material (it may also be configured using a resin material). A fuel filler port 32 is provided at the top of the fuel tank 30 and is used when refilling with fuel from a refueling facility on the ground (such as a gas station), and a cap 34 with an intake and exhaust valve is removably attached to the tip of the fuel filler port 32. A fuel sensor (e.g., a float-type on-off switch) is provided inside the fuel tank 30 (not shown) for detecting when the fuel has reached the maximum storage amount (so-called full tank state).

[0027] Furthermore, the work vehicle 1 is equipped with a fuel supply device 60 for supplying fuel to the fuel tank 30, mounted in the equipment room 20 of the upper body 3. The fuel supply device 60 according to this embodiment is equipped with a fuel supply passage 62 having a fuel supply hose 62a at one end and the other end connected (communicating) to the fuel tank 30, a fuel supply pump (not shown) provided midway along the fuel supply passage 62 for feeding fuel, and a start switch 66 for the fuel supply pump.

[0028] As an example, the fuel pump is configured using an electric gear pump or the like, and can be driven by power supplied from a battery (not shown) even when the engine 18 is stopped. The start switch 66 is configured using a push-button type alternate switch, and when pressed once, the fuel pump starts and remains in a driven state, and when pressed again, the fuel pump stops. The work vehicle 1 is provided with a control mechanism (not shown) that controls the fuel pump and the like, and this control mechanism performs control to automatically stop the fuel pump when the above-mentioned fuel sensor detects a full tank state.

[0029] Furthermore, the fuel supply passage 62 is configured using a metal or rubber (oil-resistant rubber) pipe, hose, etc. The fuel supply hose 62a forming one end thereof is configured to be able to be pulled out by being wound around a hose reel (not shown), and is provided with a strainer and a check valve at the tip.

[0030] According to the above configuration, by inserting the tip of the fuel supply hose 62a into a container (such as a drum) containing fuel and driving the fuel supply pump, fuel can be sucked up from the container and sent to the fuel tank 30.

[0031] However, as mentioned above, there are an increasing number of cases where caps 34 with a highly airtight structure that strengthens the prevention of fuel spillage in the event of a fall are attached to the fuel tank 30. Therefore, when fuel is replenished into the fuel tank 30 using the fuel supply device 60 with the cap 34 attached to the fuel filler opening 32, the internal pressure of the fuel tank 30 increases, and there is a risk of damage such as rupture of the tank casing.

[0032] The work vehicle 1 according to this embodiment is provided with the following configuration to solve this problem. Specifically, the work vehicle 1 is provided with an exhaust passage 72 that has one end open to the atmosphere and the other end connected (communicated) with the fuel tank 30, and an opening / closing valve 74 that is provided midway along the exhaust passage 72 and opens and closes the flow path.

[0033] According to the above configuration, when fuel is supplied to the fuel tank 30 using the fuel supply device 60 (i.e., when the fuel supply pump is driven), the on-off valve 74 is opened to allow flow through the exhaust path 72. Therefore, when fuel is supplied to the fuel tank 30 with the cap 34 attached to the fuel filler opening 32 and the internal pressure of the fuel tank 30 rises, the air inside the fuel tank 30 is discharged through the exhaust path 72 in response to the rise. In other words, since the internal pressure of the fuel tank 30 can be prevented from rising, damage such as the rupture of the tank casing caused by the internal pressure rise can be prevented.

[0034] As an example, the opening / closing valve 74 is fixed to the center of the front surface 30c (or may be at another position). The exhaust passage 72 is configured using a rubber / resin hose (or may be a metal pipe), and is fixed (engaged) so as to extend from the top surface 30a of the fuel tank 30 slightly toward the right side surface 30b, and reach the lower end of the front surface 30c. In particular, in this embodiment, the exhaust passage 72 is connected to the center of the top surface 30a of the fuel tank 30, and is disposed so as to pass under the upper cover 36 attached to the top surface 30a (see FIGS. 2 and 3).

[0035] According to the above configuration, first, by the configuration in which the exhaust passage 72 is connected to the upper surface 30a of the fuel tank 30, it is possible to obtain the effect that fuel does not flow out from the exhaust passage 72 even if the fuel tank 30 is in a full tank state. In addition, by the configuration in which the connection position is set to the center of the upper surface 30a of the fuel tank 30, it is possible to maintain the above effect as long as possible (not to be impaired as much as possible) even if the vehicle body (upper body 3) is tilted in any direction. Furthermore, it is possible to assume that the upper position of the fuel tank 30 is used as a foothold for workers when performing various maintenance work on the vehicle body (upper body 3), for example. In response to this, by the configuration in which the upper cover 36 is attached to the upper surface 30a of the fuel tank 30 and a space is provided between the upper surface 30a and the upper cover 36 in which the exhaust passage 72 is set (laid), it is possible to prevent workers from stepping on and damaging the exhaust passage 72.

[0036] In this embodiment, a normally closed type electromagnetically driven opening / closing valve is used as the opening / closing valve 74, and the control mechanism controls the opening / closing valve 74 to be "open" when the fuel supply pump is on (driving state), and to be "closed" when the fuel supply pump is off (stopped state) (since the opening / closing valve is a normally closed type electromagnetically driven opening / closing valve, the opening / closing valve 74 is "open" when the solenoid is energized and in the "on" state). In other words, the control mechanism does not determine whether the cap 34 is attached to the fuel supply port 32, but executes the on ("open") operation of the opening / closing valve 74 in response only to the fuel supply pump being in the on state.

[0037] According to the above-mentioned configuration, an electromagnetically driven opening / closing valve is used as the opening / closing valve 74 and the on / off, i.e., opening / closing operation of the opening / closing valve 74 is linked to the on / off of the fuel supply pump, thereby eliminating the hassle of operating the opening / closing valve 74 separately and the risk of forgetting to operate it.

[0038] As described above, with the above-mentioned work vehicle, when the fuel tank is refilled with fuel using the vehicle-mounted fuel pump with a tightly sealed cap attached to the fuel filler opening, the air inside the fuel tank can be discharged. This makes it possible to prevent an increase in the internal pressure of the fuel tank, thereby preventing damage such as the rupture of the tank casing caused by the internal pressure increase.

[0039] The present invention is not limited to the above embodiment (hydraulic excavator), and can be similarly applied to a work vehicle (such as a track loader) in which the upper body does not rotate relative to the lower body. [Explanation of symbols]

[0040] 1. Work vehicles 10 Running gear 12, 14 Working equipment 30 Fuel Tank 32 Fuel filler 34 Cap 60 Refueling Equipment 66 Start switch 72 Exhaust duct 74 Opening and closing valve

Claims

1. A fuel tank having a filler port and storing fuel; a fuel supply passage connected to the fuel tank separately from the fuel filler opening; a fuel supply pump provided midway along the fuel supply path; an exhaust passage connected to the fuel tank; An opening and closing valve is provided midway along the exhaust path. A work vehicle characterized by:

2. An electromagnetically driven opening / closing valve is used as the opening / closing valve, a control mechanism for turning on and off the fuel supply pump and the opening and closing valve, The control mechanism is configured to perform control such that the on-off valve is opened when the fuel supply pump is on, and the on-off valve is closed when the fuel supply pump is off.

2. The work vehicle according to claim 1,

3. The exhaust passage is connected to the center of the top surface of the fuel tank and is arranged to pass under an upper cover attached to the top surface.

3. The work vehicle according to claim 1 or 2, characterized in that

4. A cap with an intake and exhaust valve is detachably provided at the tip of the fuel filler opening, The control mechanism is configured to control the fuel supply pump to be on and the opening / closing valve to be open when the cap is attached to the fuel supply port.

3. The work vehicle according to claim 2,

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