Work machine

Abstract

To facilitate water supply work of a reductant agent.SOLUTION: A work machine (1) includes a vehicle body (1A, 1B), a work device (2) provided at a front part of the vehicle body, an engine (15) which is a driving source of the vehicle body, and a reductant agent unit (40) for storing a reductant agent to be injected to exhaust gas discharged from the engine. The reductant agent unit includes a reductant agent tank (80) having a water supply port (84) of the reductant agent on an upper part thereof, a tank storage part (60) for housing the reductant agent tank, a storage box (50) for housing the tank storage part, and a shaft support part (54, 67) for rotatably supporting the tank storage part with respect to the storage box. The tank storage part rotates around the shaft support part between a first posture in which the reductant agent tank is in a prescribed posture with respect to the storage box and a second posture in which a height position of the water supply port is lower than in the first posture.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a work machine equipped with a reducing agent tank that stores a reducing agent. [Background technology]

[0002] In recent years, in order to reduce the amount of NOx contained in exhaust gas emitted from the engines of work machines such as wheel loaders and hydraulic excavators, selective catalytic reduction (SCR) technology has been adopted to treat exhaust gas using urea water as a reducing agent.

[0003] For example, Patent Document 1 discloses a construction machine characterized in that "it is a construction machine equipped with an exhaust gas purification device that purifies exhaust gas from an engine, and further includes a tank cover that houses a reducing agent tank in which a reducing agent to be supplied to the exhaust gas purification device is stored, the reducing agent tank includes a water supply port through which the reducing agent is supplied from a refill tank, the tank cover includes an opening / closing door, and the opening / closing door of the tank cover includes a holder that holds a mounting base on which the refill tank can be placed when the reducing agent is supplied from the refill tank to the reducing agent tank, at a position higher than the water supply port of the reducing agent tank." And, according to Patent Document 1, since the refill tank can be placed on the mounting base and refilled with the reducing agent, refilling with the reducing agent is said to be easy. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6510437 Summary of the Invention [Problem to be solved by the invention]

[0005] The conventional technology described in Patent Document 1 is not configured to lower the position of the water supply port of the reducing agent tank, so when an operator wants to replenish the reducing agent from the ground, the operator must still reach up to the water supply port, which is still in a high position, or stand on a step or the like to perform the water supply work. Therefore, further improvements are needed to make the water supply work of the reducing agent easier.

[0006] The present invention has been made in view of the above-mentioned state of the prior art, and an object of the present invention is to make it easier to supply the reducing agent. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, one aspect of the present invention is a working machine comprising a vehicle body, a working device provided at a front part of the vehicle body, an engine which is a drive source of the vehicle body, and a reducing agent unit which stores a reducing agent to be injected into exhaust gas discharged from the engine, wherein the reducing agent unit includes a reducing agent tank having a water supply inlet for the reducing agent provided at an upper part, a tank accommodating section which accommodates the reducing agent tank, a storage box which accommodates the tank accommodating section, and a journal part which supports the tank accommodating section so that it can rotate freely relative to the storage box, and the tank accommodating section rotates around the journal part between a first position in which the reducing agent tank is in a predetermined position relative to the storage box, and a second position in which the height position of the water supply inlet is lower than the first position. Effect of the Invention

[0008] According to the present invention, since the position of the water supply port of the reducing agent tank can be lowered, the work of supplying the reducing agent can be performed more easily. Note that problems, configurations, and effects other than those described above will become apparent from the description of the following embodiments. [Brief description of the drawings]

[0009] [Figure 1] 1 is a side view showing the appearance of a wheel loader according to an embodiment of the present invention. [Diagram 2]FIG. 2 is a perspective view of the urea water unit as viewed diagonally from above on the left. [Diagram 3] FIG. 2 is a perspective view of the urea water unit as viewed from diagonally above to the right. [Figure 4] FIG. 2 is a plan view of the urea water unit. [Diagram 5] FIG. 2 is a front view of the urea water unit. [Figure 6] FIG. 2 is a left side view of the urea water unit. [Figure 7] FIG. 4 is a right side view of the urea water unit. [Figure 8] FIG. 2 is a perspective view of the tank case as viewed diagonally from above on the left. [Figure 9] FIG. 2 is a perspective view of the tank case as viewed from diagonally above on the right. [Figure 10] FIG. 2 is a perspective view of the urea water tank as viewed diagonally from above on the left. [Figure 11A] FIG. 1 is a diagram showing the procedure for supplying and draining urea water. [Figure 11B] FIG. 1 is a diagram showing the procedure for supplying and draining urea water. [Figure 11C] FIG. 1 is a diagram showing the procedure for supplying and draining urea water. [Figure 12] FIG. 11 is a perspective view of a urea water unit according to a modified example, as viewed from diagonally above the left. [Figure 13] FIG. 11 is a perspective view of a urea water unit according to a modified example, as viewed from diagonally above to the right. [Figure 14] FIG. 11 is a perspective view of a urea water tank according to a modified example, as viewed from diagonally above the left. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First, the overall configuration of a wheel loader 1, which is an example of a work machine according to the present invention, will be described with reference to Fig. 1. Fig. 1 is an external side view showing an example of the configuration of a wheel loader 1 according to an embodiment of the present invention.

[0011] The wheel loader 1 is an articulated work vehicle that is steered by bending the vehicle body near the center, and a front frame 1A forming the front part of the vehicle body and a rear frame 1B forming the rear part of the vehicle body are connected by a center joint 30 so as to be rotatable in the left-right direction, and the front frame 1A bends in the left-right direction relative to the rear frame 1B. In the following explanation, of the left-right direction of the vehicle body, the left direction in the forward direction is referred to as the "left direction", and the right direction in the forward direction is referred to as the "right direction".

[0012] The vehicle body is provided with four wheels 11, two of which are front wheels 11A provided on both the left and right sides of the front frame 1A, and the remaining two wheels 11 are rear wheels 11B provided on both the left and right sides of the rear frame 1B. Of the four wheels 11, only the front wheel 11A and rear wheel 11B provided on the left side are shown in FIG.

[0013] A hydraulically driven working device 2 is attached to the front of the front frame 1A for carrying out loading and unloading work such as digging up work objects such as soil and minerals and loading them into a loading destination such as a dump truck or a hopper.

[0014] The rear frame 1B is provided with a cab 12 in which an operator sits, a machine room 13 that houses various devices such as an engine 15 required to drive the wheel loader 1, and a counterweight 14 for maintaining balance with the working implement 2 so that the vehicle body does not tilt. On the rear frame 1B, the cab 12 is located at the front, the counterweight 14 at the rear, and the machine room 13 between the cab 12 and the counterweight 14.

[0015] Further, a urea water unit 40 is provided on the rear side of the left side of the rear frame 1B. A urea water tank 80 that stores urea water (reducing agent) is housed in the urea water unit 40. The urea water unit 40 will be described in detail later.

[0016] The working device 2 has a lift arm 21 attached to the front frame 1A so as to be rotatable in the vertical direction, two lift arm cylinders (not shown) as hydraulic cylinders that drive the lift arm 21, a bucket 23 attached to the tip of the lift arm 21 so as to be rotatable in the vertical direction, a bucket cylinder 24 as a hydraulic cylinder that drives the bucket 23, and a bell crank 25 rotatably connected to the lift arm 21 to form a link mechanism between the bucket 23 and the bucket cylinder 24.

[0017] The lift arm 21 rotates upward relative to the front frame 1A when the rods of the two lift arm cylinders extend, and rotates downward relative to the front frame 1A when the rods of the two lift arm cylinders contract.

[0018] The bucket 23 rotates upward relative to the lift arm 21 and tilts backward toward the front frame 1A (vehicle body) (tilt operation) as the rod of the bucket cylinder 24 extends, and rotates downward relative to the lift arm 21 and tilts forward (dump operation) as the rod of the bucket cylinder 24 contracts. This allows the bucket 23 to scoop up and discharge (discharge) work objects such as soil and minerals.

[0019] The bucket 23 can be replaced with various attachments, such as a blade, and the wheel loader 1 can perform various tasks such as snow removal and earth-pulling in addition to loading and unloading operations using the bucket 23.

[0020] This wheel loader 1 can be operated manually by an operator in the cab 12, or it can be operated remotely by an operator located away from the wheel loader 1 (autonomous running without an operator in the cab 12).

[0021] Next, the urea water unit 40 will be described. In this specification, the directions of the urea water unit 40 (storage box 50, tank case 60, urea water tank 80) are defined as directions when the urea water unit 40 is viewed from the left side of the wheel loader 1. Therefore, the left, right, front, and rear of the urea water unit 40 are defined as shown in Figures 2 and 3, and are respectively the front side, rear side, left side, and right side of the vehicle body (wheel loader 1).

[0022] Figure 2 is an oblique view of the urea water unit 40 seen from diagonally above the left, Figure 3 is an oblique view of the urea water unit 40 seen from diagonally above the right, Figure 4 is a plan view of the urea water unit 40, Figure 5 is a front view of the urea water unit 40, Figure 6 is a left side view of the urea water unit 40, Figure 7 is a right side view of the urea water unit 40, Figure 8 is an oblique view of the tank case 60 seen from diagonally above the left, Figure 9 is an oblique view of the tank case 60 seen from diagonally above the right, and Figure 10 is an oblique view of the urea water tank 80 seen from diagonally above the left.

[0023] As shown in these figures, the urea water unit (reducing agent unit) 40 according to this embodiment includes a storage box 50, a tank case (tank housing portion) 60, and a urea water tank (reducing agent tank) 80.

[0024] The storage box 50 is configured in a box shape and is used to house the tank case 60 and the urea water tank 80. The storage box 50 has a bottomed box body 51 that is open at the top, a pair of side plates 51a extending forward on the right side of the box body 51, a top lid 52 that covers the box body 51 from above, and a front lid 53 that closes an opening provided in the front face of the box body 51. The box body 51 houses the tank case 60 and the urea water tank 80, and also houses mechanical parts such as a pump and hoses and wiring, although not shown.

[0025] The pair of side plates 51a are each provided with an arc-shaped guide groove 56. A locking shaft 68, which will be described later, is inserted into the guide groove 56 so that the locking shaft 68 can slide freely within the guide groove 56. The guide groove 56 is provided with a straight portion 56a and an arc portion 56b. The locking shaft 68 is temporarily held by the straight portion 56a, and rotation of the tank case 60 is prohibited (see FIG. 7). On the other hand, the locking shaft 68 slides within the arc portion 56b, thereby allowing rotation of the tank case 60. Here, the straight portion 56a corresponds to the "position maintaining portion" of the present invention, and the arc portion 56b corresponds to the "rotation allowing portion" of the present invention.

[0026] Furthermore, a protrusion 57 is provided on the left side plate 51a. This protrusion 57 is for engaging a hook 69, which will be described later. The protrusion 57 and the hook 69 correspond to the "lock mechanism" of the present invention. A notch 51b is provided in the lower part of the left side plate 51a. A drain cover 66, which will be described later, is exposed through this notch 51b.

[0027] The tank case 60 includes a case body 61 (see FIGS. 8 and 9) for accommodating the urea water tank 80. The case body 61 has a front plate 61a and a pair of side plates 61b, and is formed in a box shape with an open top and a closed bottom.

[0028] The top lid 62 is fixed to the front plate 61a and the pair of side plates 61b with screws 71, and covers the upper front surface of the case body 61. The top lid 62 is provided so as to incline downward from the rear to the front. The top lid 62 is provided with a water supply port cover 63 that opens and closes via a hinge 64. The water supply port cover 63 is fixed to the top lid 62 via a fastener 70. When the fastener 70 is released to open the water supply port cover 63, the water supply cap 81 of the urea water tank 80 is exposed (see FIG. 11C). The opening and closing direction of the water supply port cover 63 is the same as the rotation direction of the tank case 60. A handle 65 is provided on the lower part of the front plate 61a.

[0029] A pair of rotation shafts 67 and locking shafts 68 are provided on each of the pair of side plates 61b. The pair of rotation shafts 67 are located at corners of the case body 61, diagonally to the water supply port cover 63. Specifically, the pair of rotation shafts 67 are provided at the rear lower part of the case body 61, diagonally to the water supply port 84 of the urea water tank 80 when the urea water tank 80 is housed in the case body 61. The pair of rotation shafts 67 extend horizontally and constitute a first axis 45.

[0030] The pair of rotating shafts 67 are inserted into and journaled in a pair of shaft holes 54 (see Figs. 3 and 7) provided in the side plates 51a of the box body 51. In this way, the tank case 60 rotates in the vertical direction about the first shaft 45 extending in the fore-and-aft direction of the vehicle body. The pair of rotating shafts 67 and the pair of shaft holes 54 correspond to the "journal support" of the present invention.

[0031] On the other hand, the locking shaft 68 is provided at an upper part slightly forward of the side plate 61b of the case main body 61. The locking shaft 68 is inserted into a guide groove 56 provided in the side plate 51a of the box main body 51, and when the tank case 60 rotates in the up-down direction around the first shaft 45, the locking shaft 68 moves within the guide groove 56 while being guided by the guide groove 56. In other words, the locking shaft 68 is guided by the guide groove 56, and the tank case 60 rotates around the rotation shaft 67.

[0032] A hook 69 formed in the shape of a slightly bent elongated plate is attached to a locking shaft 68 provided on the left side plate 61b. The hook 69 is rotatable around the locking shaft 68. A locking groove 69a is provided on the end of the hook 69 opposite the locking shaft 68. The locking groove 69a is formed so as to be engageable with a protrusion 57 provided on the side plate 51a of the box body 51. When the locking groove 69a of the hook 69 engages with the protrusion 57, the tank case 60 is fixed in a state where it is housed in the storage box 50. The axial directions of the rotation shaft 67 and the locking shaft 68 are perpendicular to the surface of the side plate 61b.

[0033] Furthermore, a drain port cover 66 is provided at a lower front position of the left side plate 61b. The drain port cover 66 is fixed to the side plate 61b with screws 72. When the screws 72 are loosened and the drain port cover 66 is removed, a drain plug 82 of the urea water tank 80 is exposed (see FIG. 11C).

[0034] The urea water tank 80 is a hollow box-shaped container and stores urea water therein (see FIG. 10). The urea water tank 80 has a water supply cap 81, a drain plug 82, and a hose connection part 83. The water supply cap 81 is provided on an inclined surface 86 at the upper front part of the urea water tank 80, and a water supply port 84 is exposed when the water supply cap 81 is opened. The position of the water supply port 84 is not limited to that shown in FIG. 10. Urea water is supplied to the urea water tank 80 from the water supply port 84. The drain plug 82 is provided at the lower front part of the side of the urea water tank 80, and a drain port 85 is exposed when the drain plug 82 is pulled. Urea water remaining in the urea water tank 80 is discharged from the drain port 85.

[0035] Here, to explain in detail the positions of the water inlet 84 and the drain outlet 85, when looking at the urea water tank 80 from the side, the water inlet 84 (water inlet cap 81) and the drain outlet 85 (drain plug 82) are located vertically spaced apart and on approximately the same vertical line (strictly speaking, the drain outlet 85 is slightly forward of the water inlet 84).

[0036] Although not shown, a urea water hose and sensors are attached to the hose connection portion 83.

[0037] Next, the procedure for supplying and draining urea water will be described. Figs. 11A to 11C are diagrams showing the procedure for supplying and draining urea water. When supplying or draining urea water to the urea water tank 80, the operator first turns the hook 69 in the direction of the arrow A in the figure as shown in Fig. 11A to release the locking and fixing of the tank case 60. At this time, since the guide groove 56 is provided with the straight portion 56a, the locking shaft 68 remains in the straight portion 56a. Therefore, the tank case 60 is maintained in a horizontal position (first position), which is an example of a predetermined position, and the tank case 60 does not suddenly rotate to the front side.

[0038] Next, the worker grasps the handle 65 and rotates the tank case 60 in the direction of arrow B in Figure 11B. Then, while the locking shaft 68 is guided by the guide groove 56, the tank case 60 rotates downward about the rotation shaft 67.

[0039] 11C, when the locking shaft 68 abuts against the end of the guide groove 56, the position of the water supply port 84 is lowered and the tank case 60 is held in a position (second position) in which water can be supplied. In this state, the operator releases the fixing device 70 and rotates the water supply port cover 63 in the direction of arrow C in the figure. This exposes the water supply cap 81 of the urea water tank 80, so the operator can open the water supply cap 81 and refill the urea water tank 80 with urea water. Also, in FIG. 11C, the operator can remove the drain port cover 66 and pull the drain plug 82 to drain the urea water remaining in the urea water tank 80.

[0040] The urea water unit 40 described above can provide the following advantageous effects.

[0041] A pair of pivot shafts 67 provided on the case body 61 of the tank case 60 are positioned diagonally to the water supply port 84 and the water supply cap 81 of the urea water tank 80 when the urea water tank 80 is housed in the case body 61. Therefore, by rotating the tank case 60 about the first shaft 45 extending in the front-rear direction of the vehicle body and tilting it to the second position shown in Fig. 11C, the height position of the water supply port 84 of the urea water tank 80 can be lowered. This makes it very easy to supply urea water. In particular, since the water supply port 84 and the water supply cap 81 are provided on the inclined surface 86 of the urea water tank 80, it is easy to refill the urea water.

[0042] In addition, since the drain plug 82 is provided at the front lower part of the side surface of the urea water tank 80, the urea water remaining in the urea water tank 80 can be easily drained by tilting the tank case 60 forward. Moreover, since the drain plug 82 is located lower than the first shaft 45 (rotation shaft 67) in Fig. 11C, almost all of the urea water in the urea water tank 80 can be drained.

[0043] Here, since the locking shaft 68 is inserted and guided in the guide groove 56, when rotating the tank case 60, the tank case 60 can be rotated stably simply by removing the hook 69 from the projection 57 and grasping the handle 65 and tilting it towards oneself.

[0044] Moreover, since the straight portion 56a is provided in the guide groove 56, when the hook 69 is removed from the protrusion 57, the tank case 60 is temporarily held in a horizontal position. This prevents the tank case 60 from rotating unexpectedly, improving the workability of the urea water supply and drainage work. In addition, the tank case 60 is configured to be pulled out toward the outside of the vehicle body, and the water supply port 84 of the urea water tank 80 is also configured to face toward the outside of the vehicle body. In other words, the tank case 60 and the water supply port 84 of the urea water tank 80 are configured to be accessible to a maintenance worker from a wide work area outside the vehicle body. This allows the maintenance worker to perform the water supply work without being restricted in movement, improving the workability of the urea water supply and drainage work.

[0045] Furthermore, the tank case 60 can be fixed in the first position simply by engaging the hook 69 with the projection 57, which provides high convenience. Also, the water inlet cover 63 is configured to open via the hinge 64 to the front side, which is the same direction as the rotation of the tank case 60, and the open state is maintained by the weight of the water inlet cover 63. Therefore, there is no need to hold down the water inlet cover 63 with one hand to prevent it from closing unintentionally during the water supply operation of the urea water, and the water inlet cover 63 does not get in the way of the operation.

[0046] Next, modified examples of the urea water unit 40 will be described with reference to Figures 12 to 14. In Figures 12 to 14, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0047] 12 to 14, the urea water unit 40-1 according to the modified example is characterized in that the drain port cover 66 is provided at the bottom of the front plate 61a of the case body 61, and the drain plug 82 of the urea water tank 80-1 is provided at the bottom of the front surface. Even with this configuration, the same effects as those of the above-mentioned embodiment can be achieved.

[0048] The above describes the embodiment and the modified examples of the present invention. Note that the present invention is not limited to the above-described embodiment and modified examples, and includes various other modified examples. For example, the above-described embodiment and modified examples have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of this embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of this embodiment. Furthermore, it is possible to add, delete, or replace a part of the configuration of this embodiment with another configuration.

[0049] For example, the "axial support portion" of the present invention may be configured by providing the rotating shaft 67 on the storage box 50 side and the shaft hole 54 on the tank case 60 side. That is, in the present invention, the axial support portion may have any configuration as long as it can support the tank case 60 rotatably around the first shaft 45.

[0050] Furthermore, in the above embodiment, a wheel loader has been given as an example of one aspect of the work machine of the present invention, but the present invention is not limited to this and may be, for example, a hydraulic excavator or the like. [Explanation of symbols]

[0051] 1. Wheel loader (work machine) 1A Front frame (body) 1B Rear frame (body) 2. Working Equipment 11A front wheel 11B rear wheel 15 Engine 40,40-1 Urea solution unit (reducing agent unit) 45 1st axis 50 Storage Box 51 Box body 51a side plate 51b Notch 52 Top lid 53 Front lid 54 Shaft hole (shaft support) 56 Guide groove 56a Straight section (posture maintenance section) 56b Arc section (rotation allowance section) 57 Protrusion (locking mechanism) 60 Tank case (tank housing section) 61 Case body 61a Front plate 61b side plate 62 Top lid 63 Water inlet cover 64 Hinge 65 Handle 66 Drain Cover 67 Rotating shaft (support part) 68 Locking shaft (guide mechanism) 69 Hook (locking mechanism) 69a Locking groove (locking mechanism) 70 Fixtures 71,72 Screw 80,80-1 Urea tank (reducing agent tank) 81 Water supply cap 82 Drain plug 83 Hose connection 84 Water inlet 85 Drain 86 Slope

Claims

1. A work machine including a vehicle body, a working device provided at a front portion of the vehicle body, an engine that is a drive source of the vehicle body, and a reducing agent unit that stores a reducing agent to be injected into exhaust gas discharged from the engine, The reducing agent unit is A reducing agent tank having a water supply port for the reducing agent provided at an upper portion thereof; a tank housing portion that houses the reducing agent tank; A storage box that stores the tank storage portion; a support portion that supports the tank housing portion so as to be rotatable relative to the storage box, the tank accommodating portion rotates around the pivot portion between a first position in which the reducing agent tank is in a predetermined position with respect to the storage box and a second position in which a height position of the water supply port is lowered from that of the first position; A working machine characterized by:

2. 2. The work machine according to claim 1, The reducing agent tank is formed of a hollow box-shaped container and has a drainage outlet for the reducing agent at a lower portion on a side where the water supply port is provided. A working machine characterized by:

3. 2. The work machine according to claim 1, the reducing agent unit includes a guide groove that guides the tank accommodation portion to rotate between the first position and the second position, the guide groove includes an attitude maintaining portion that prohibits the tank accommodating portion from rotating between the first attitude and the second attitude, and a rotation allowing portion that allows the tank accommodating portion to rotate between the first attitude and the second attitude. A working machine characterized by:

4. 2. The work machine according to claim 1, The reducing agent unit includes a locking mechanism that locks the tank accommodation portion in the first position. A working machine characterized by:

5. 2. The work machine according to claim 1, The tank housing portion includes a water supply port cover that closes the water supply port, The water supply port cover opens and closes via a hinge in the same direction as the rotation direction of the tank housing part. A working machine characterized by:

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