CN213062143U - Excavator - Google Patents

Abstract

The utility model provides a can restrain because of freezing of liquid reductant such as urea water and lead to the excavator that the filling device is pushed up. The shovel is provided with: an upper slewing body; an engine mounted on the upper slewing body; a revolving frame constituting a part of the upper revolving structure; a tank for a liquid reducing agent mounted on the revolving frame; a filler installed at an upper portion of the tank for the liquid reducing agent; and a liquid level limiting component which is positioned below the filling device and is an elastic body.

Description

Excavator

Technical Field

The present application claims priority based on japanese patent application No. 2019-144792, filed 8/6/2019. The entire contents of this Japanese application are incorporated by reference into this specification.

The utility model relates to an excavator.

Background

Conventionally, a filler for guiding a liquid reducing agent such as urea water into a tank for the liquid reducing agent is attached to an upper portion of the tank for the liquid reducing agent provided in a shovel. A conventional filler is integrally formed with a cylindrical protruding portion protruding into a tank for a liquid reducing agent, and the height position of the liquid surface of the liquid reducing agent in the tank for the liquid reducing agent can be regulated by the lower end portion of the protruding portion (see, for example, patent document 1 below).

Patent document 1: japanese patent laid-open publication No. 2015-541588

However, in a state where the liquid reducing agent is supplied to the lower end portion of the convex portion of the filler, when the liquid reducing agent freezes, the lower end portion of the convex portion of the filler is pushed up by the liquid surface on which the liquid reducing agent freezes due to expansion of the liquid reducing agent. In this case, since the filler is screwed and fixed to the upper surface of the tank for the liquid reducing agent, a load may be concentrated on the screw-fastened portion of the filler, and a crack may be generated in the screw-fastened portion. In this case, the packing is pushed up to increase a gap between the installation surface of the packing and the upper surface of the tank for the liquid reducing agent, and the sealing performance by the O-ring in the gap is lowered, so that the liquid reducing agent may leak from the gap.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a can restrain because of freezing of liquid reductant such as urea water and lead to the excavator that the filling device is pushed up.

An excavator according to an embodiment includes an upper slewing body, an engine mounted on the upper slewing body, a slewing frame constituting a part of the upper slewing body, a tank for a liquid reducing agent mounted on the slewing frame, a filler attached to an upper part of the tank for the liquid reducing agent, and a liquid level regulating member located below the filler, wherein the liquid level regulating member is an elastic body.

Effect of the utility model

The utility model discloses can provide one kind can restrain because of liquid reductant such as urea water freezes and lead to the excavator that the filling device is pushed up.

Drawings

Fig. 1 is a side view of a shovel according to an embodiment of the present invention.

Fig. 2 is a plan view schematically showing an upper revolving body of the excavator of fig. 1.

Fig. 3 is a diagram showing a configuration example of an exhaust gas treatment device mounted on the shovel of fig. 1.

Fig. 4 is a perspective view of the right front portion of the excavator viewed from obliquely above left.

Fig. 5 is a side view of the right front portion of the upper slewing body as viewed from the right side.

Fig. 6 is a longitudinal sectional view of the urea water tank.

Fig. 7 is an exploded perspective view of the filler and the liquid level regulating member.

Fig. 8 is an enlarged sectional view of a mounting portion of a filler in a urea water tank.

Fig. 9 is a longitudinal sectional view of a urea water tank in a modified excavator.

In the figure: 100-excavator, 1-lower running body, 2-upper revolving body, 8-diesel engine (engine), 20-urea water tank (tank for liquid reducing agent), 20 a-tank upper surface, 20 h-liquid supply port, 20 g-inclined surface, 22-filler, 22 a-main body, 22 b-base, 22 c-set screw, 22 d-concave, 22 e-reinforcing rib, 22 f-vent, 23-filler cap, 24-liquid level limiting component, 24 a-cylinder, 24 b-flange, 24 c-lower end, 26-liquid level meter (level meter), 31-revolving frame, 74-urea water residual sensor.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings. For the sake of easy understanding of the description, the same components are denoted by the same reference numerals as much as possible in the drawings, and redundant description is omitted.

In the following description, the positive X-axis direction and the negative X-axis direction are the front and the rear of the shovel 100. The positive Y-axis direction and the negative Y-axis direction are left and right of the shovel 100. The positive Z-axis direction and the negative Z-axis direction are the upper and lower sides of the shovel 100.

Fig. 1 is a side view of a shovel 100 according to an embodiment of the present invention. As shown in fig. 1, the shovel 100 includes a lower traveling structure 1, an upper revolving structure 2, a cab 3, a boom 4, an arm 5, and a bucket 6.

The upper slewing body 2 is mounted on the lower traveling body 1 via a slewing mechanism (not shown). The cab 3 is provided in the left front portion of the upper revolving structure 2. The cab 3 is provided with a driver seat therein. The boom 4 is rotatably provided at the front center of the upper slewing body 2. The arm 5 is rotatably provided at the tip end of the boom 4. Bucket 6 is an example of a terminal attachment, and is rotatably provided at a distal end portion of arm 5.

Fig. 2 is a plan view schematically showing the upper revolving structure 2 of the shovel 100 shown in fig. 1. As shown in fig. 2, an engine room 7 is formed in the upper slewing body 2. A diesel engine 8 (an example of an "engine") is provided in the engine room 7. A cooling fan 12 is provided on the left side (Y-axis positive side) of the diesel engine 8. A heat exchanger unit 13 including a cooler and the like is provided on the left side (Y-axis positive side) of the cooling fan 12.

The diesel engine 8 sucks in outside air through an air filter 9a and an intake pipe 9b provided outside the engine room 7. An exhaust pipe 9c is connected to the diesel engine 8. An exhaust treatment device 10 for purifying nitrogen oxides (hereinafter referred to as NOx) in the exhaust gas discharged from the diesel engine 8 is provided on the downstream side of the exhaust pipe 9 c.

In the present embodiment, the exhaust gas treatment device 10 is a urea selective reduction type NOx treatment device using urea water as a reducing agent. The exhaust gas treatment device 10 reduces NOx (nitrogen oxides) in the exhaust gas by injecting urea water to the upstream side of a reduction catalyst (not shown) provided in the exhaust pipe 9c, and makes NOx harmless by promoting the reduction reaction by the reduction catalyst.

A urea water tank 20, a fuel tank 19, and a hydraulic oil tank 18 are arranged in this order from the front side on the right side of the upper slewing body 2 and in front of the engine room 7. The urea water tank 20 (an example of a tank for a liquid reducing agent) is a container for storing urea water. The urea water tank 20 is connected to the exhaust gas treatment device 10 via a urea water hose 69 and a urea water supply pump 70.

Fig. 3 is a diagram showing a configuration example of exhaust gas treatment device 10 mounted on excavator 100 in fig. 1. The diesel engine 8 is controlled by an engine control module (hereinafter, referred to as "ECM") 60.

The air introduced into the intake pipe 9b through the air filter 9a is supplied to the diesel engine 8 through the turbocharger 61, the intercooler 65, and the like. The exhaust gas from the diesel engine 8 passes through the turbocharger 61, reaches the exhaust pipe 9c downstream thereof, is subjected to purification treatment by the exhaust gas treatment device 10, and is discharged into the atmosphere.

A diesel particulate filter 66 that traps particulate matter in the exhaust gas and a selective reduction catalyst 67 that reduces and removes NOx in the exhaust gas are provided in series in the exhaust pipe 9 c.

The selective reduction catalyst 67 receives the supply of the reducing agent and continuously reduces and removes nox in the exhaust gas. In the present embodiment, an aqueous urea solution (urea aqueous solution) is used as the reducing agent from the viewpoint of easy operability.

A urea solution injector 68 for supplying urea solution to the selective reduction catalyst 67 is provided in the exhaust pipe 9c on the upstream side of the selective reduction catalyst 67. The urea solution injector 68 is connected to the urea solution tank 20 via a urea solution hose 69.

A supply module SM is provided in the middle of the urea water hose 69. The supply module SM includes a urea water supply pump 70 and a filter 71. In the present embodiment, the supply module SM is configured such that a filter 71 is disposed between the urea water tank 20 and the urea water supply pump 70.

The urea aqueous solution stored in the urea aqueous solution tank 20 is supplied to the urea aqueous solution injection device 68 by the urea aqueous solution supply pump 70, and is injected from the urea aqueous solution injection device 68 to a position upstream of the selective reduction catalyst 67 in the exhaust pipe 9 c.

The urea aqueous solution injected from the urea aqueous solution injector 68 is supplied to the selective reduction catalyst 67. The supplied urea water is hydrolyzed in the selective reduction catalyst 67 to generate ammonia. This ammonia reduces NOx contained in the exhaust gas in the selective reduction catalyst 67. In this way, the exhaust gas is purified.

The 1 st NOx sensor 72 and the 2 nd NOx sensor 73 are sensors that detect the NOx concentration in the exhaust gas. In the present embodiment, the 1 st NOx sensor 72 is disposed on the upstream side of the urea solution injection device 68, and the 2 nd NOx sensor 73 is disposed on the downstream side of the selective reduction catalyst 67.

The remaining urea solution amount sensor 74 detects the remaining urea solution amount in the urea solution tank 20. In the present embodiment, the remaining amount of urea solution sensor 74 is a so-called float-type sensor that is provided in the tank so as to be movable in the vertical direction and detects the remaining amount of urea solution based on the position of a float floating on the liquid surface. The remaining amount of urea solution sensor 74 outputs information on the remaining amount of urea solution to the exhaust controller 75.

The urea quality sensor 25 is a sensor for detecting the quality of the urea water in the urea water tank 20. The urea quality sensor 25 outputs information on the urea quality to the exhaust controller 75.

The exhaust controller 75 is connected to the 1 st NOx sensor 72, the 2 nd NOx sensor 73, the remaining amount of urea water sensor 74, the urea quality sensor 25, the urea water injection device 68, and the urea water supply pump 70. The exhaust controller 75 controls the urea solution injection device 68 and the urea solution supply pump 70 to inject an appropriate amount of urea solution based on the NOx concentrations detected by the 1 st NOx sensor 72 and the 2 nd NOx sensor 73, respectively.

The exhaust controller 75 calculates a ratio of the remaining amount of urea solution to the total volume of the urea solution tank 20 based on the remaining amount of urea solution output from the remaining amount of urea solution sensor 74. In the present embodiment, the ratio of the remaining amount of urea solution to the total volume of the urea solution tank 20 is defined as a remaining amount ratio of urea solution. For example, the remaining urea solution ratio of 50% indicates that urea solution half the capacity of the urea water tank 20 remains in the urea water tank 20.

The exhaust controller 75 is connected to the ECM60 via a communication mechanism. The ECM60 is connected to the shovel controller 76 via a communication means, and the shovel controller 76 is connected to the monitor 77 via a communication means. The monitor 77 displays a warning, an operation state, and the like.

The exhaust controller 75 may be referred to as a DCU (Dosing Control Unit), the ECM60 may be referred to as an ECU (Engine Control Unit), and the shovel controller 76 may be referred to as an MCU (Main Control Unit).

Various information related to the exhaust gas treatment device 10 included in the exhaust gas controller 75 can be shared by the shovel controller 76. The ECM60, the exhaust controller 75, and the shovel controller 76 are each an arithmetic device including a CPU, a RAM, a ROM, an input/output port, a storage device, and the like.

Further, exhaust gas treatment device 10 has a heat supply function of supplying heat to urea water tank 20 and urea water hose 69. The heat supply function is performed, for example, to prevent freezing of the urea water in cold regions or to melt the frozen urea water. In the present embodiment, engine cooling water (for example, long-life coolant) of the diesel engine 8 that passes through the cooling water hose 80 is used.

Specifically, the engine coolant immediately after cooling the diesel engine 8 passes through the 1 st portion 81 of the coolant hose 80 to reach the 2 nd portion 82 while maintaining a relatively high temperature. The 2 nd section 82 is a portion of the cooling water hose 80 that contacts the outer surface of the urea water tank 20. The engine cooling water having a temperature higher than that of the urea water supplies heat to the urea water tank 20 and the urea water present therein when flowing through the flow-through section 2 82.

Then, the engine cooling water reaches the 3 rd portion 83 and the supply module SM. The 3 rd portion 83 is a portion of the cooling water hose 80 that is in close contact with the urea water hose 69. The engine coolant having a temperature higher than that of the urea water supplies heat to the urea water hose 69 and the urea water present therein when flowing through the 3 rd portion 83 of the coolant hose 80 along the urea water hose 69. When the engine coolant having a temperature higher than that of the urea solution flows through the flow path formed in the supply module SM, heat is supplied to the supply module SM (including the urea solution supply pump 70 and the filter 71) and the urea solution present therein.

Then, the engine cooling water that has finished supplying heat in the 2 nd and 3 rd portions 82 and 83 and has a relatively low temperature reaches the heat exchanger unit 13 through the 4 th portion 84 of the cooling water hose 80 (refer to fig. 2). The 4 th portion 84 is a portion of the cooling water hose 80 that is laid between the 3 rd portion 83 and the 5 th portion 85 and the heat exchanger unit 13, and is not in close contact with the urea water hose 69.

The 5 th section 85 is a part of the cooling water hose 80 for cooling the urea solution injection device 68. When the engine cooling water having a temperature lower than that of the urea solution injection device 68 in the high-temperature state flows through the 5 th section 85, the engine cooling water deprives heat from the urea solution injection device 68 in the high-temperature state to cool the urea solution injection device 68 and prevent overheating thereof. Then, the engine cooling water that has been heated to a relatively high temperature (a temperature higher than the urea water temperature) by the supply of heat supplies heat to the urea water hose 69 and the urea water present inside the same when flowing through the portion 85a along the urea water hose 69. When the urea solution injection device 68 is in the low temperature state, the engine cooling water having a temperature higher than that of the urea solution injection device 68 in the low temperature state supplies heat to the urea solution injection device 68 and the urea solution present therein when passing through the 5 th section 85. Then, the engine cooling water that has been supplied with heat at the end portion 85a and has a relatively low temperature merges with the engine cooling water that has flowed from the 3 rd portion 83, and then reaches the heat exchanger unit 13 through the 4 th portion 84.

In this manner, the heat supply function supplies heat to the urea water tank 20, the urea water hose 69, the supply module SM, and the urea water injection device 68 by the engine coolant, and prevents freezing of the urea water present inside them or melts the frozen urea water.

Next, details of the right front portion of the upper slewing body 2 will be described with reference to fig. 4 and 5. Fig. 4 is a perspective view of the right front portion of the shovel 100 viewed from obliquely above and to the left. Fig. 5 is a side view of the right front portion of the upper slewing body 2 as viewed from the right side. In addition, the inside of the lifting device 30 is shown in a perspective manner in fig. 5.

The lifting device 30 is a structure used by an operator to lift the upper slewing body 2. In the present embodiment, the lifting device 30 is disposed in front of the fuel tank 19, and covers the urea water tank 20 and the housing portion 21.

The fuel tank 19 is a tank for storing fuel of the diesel engine 8, and is firmly fixed to a revolving frame 31 constituting a part (floor) of the upper revolving structure 2. A fuel tank lower cover 31v is attached to a lower portion of the fuel tank 19. The fuel tank lower cover 31v is fastened and fixed to the revolving frame 31 by a fastener such as a bolt that can be inserted from the outside (bottom side).

The urea water tank 20 is a tank storing an aqueous urea solution as a liquid reducing agent used in an SCR system (selective catalytic reduction system), and is firmly fixed to the revolving frame 31. A lower cover 31w for the urea water tank is attached to a lower portion of the urea water tank 20. The urea water tank lower cover 31w is fastened and fixed to the revolving frame 31 by a fastener such as a bolt that can be inserted from the outside (bottom side) in the same manner as the fuel tank lower cover 31 v. Similarly, an engine lower cover (not shown) attached to a lower portion of the engine, a cooler lower cover (not shown) attached to a lower portion of the cooler, and the like are fastened and fixed to revolving frame 31 by a fastener such as a bolt that can be inserted and removed from an outer side (bottom side).

The housing portion 21 is a collection of members that divide a housing space, and is formed in a shape of a box, a container, a partition, or the like, for example. In the present embodiment, the housing portion 21 is disposed on the opposite side of the cab 3 across the boom 4 in the upper revolving structure 2. The housing unit 21 has a housing space 21a defined by the lifting device 30 and the revolving frame 31. The housing space 21a houses a container 21b such as tools and a fuel pump used for maintenance. A bottom plate 32 is attached below the housing portion 21. Here, the space between the housing space 21a and the space where the urea water tank 20 is disposed may be divided by a plate, or the space may be connected without providing a plate.

As shown in fig. 4, a pair of left and right boom attachment support frames 17 are erected in front of the revolving frame 31 of the upper revolving structure 2. A fuel tank 19 and a lift 30 are disposed on the right side of the support frame 17. Further, an armrest 33 is provided outside the lifting device 30, and is gripped by a worker when the lifting device 30 is lifted.

The lifting device 30 includes a1 st lifting unit 30A and a2 nd lifting unit 30B. The 1 st elevating unit 30A functions as a step for an operator to ascend and descend, and also functions as a cover covering the urea water tank 20 and a part of the housing unit 21. The 2 nd elevating part 30B is located at the lowermost stage of the elevating device 30. The 2 nd elevating unit 30B is made of metal and fixed to the revolving frame 31. The 2 nd raising/lowering unit 30B is configured to project forward from the front end portion of the revolving frame 31.

The lifting device 30 has a 3-stage structure including 2 step portions 44 and 45 and 2 riser portions 48 and 49 in the 1 st lifting unit 30A and the 2 nd lifting unit 30B. The number of the step portions provided in the 1 st raising/lowering portion 30A is not limited to 2.

The pedal portion 44 is configured as an openable/closable portion. In the present embodiment, the pedal portion 44 is configured to open upward as shown in fig. 5. The worker can take in and out a tool or the like to and from the housing portion 21 by opening the step portion 44. Also, the pedal portion 44 can be locked with a key 44 a.

The riser portion 49 is configured as an openable/closable opening/closing portion. In the present embodiment, the vertical plate portion 49 is configured to open laterally. The operator can access the filler 22 of the urea water tank 20 by opening the vertical plate portion 49.

Next, the details of the structure of the urea water tank 20 will be described with reference to fig. 6. Fig. 6 is a longitudinal sectional view of the urea water tank 20.

The urea water tank 20 is made of resin and has a substantially rectangular parallelepiped shape. The urea water tank 20 is configured to have a tank upper surface 20a, a tank bottom surface 20b, a tank front surface 20c, a tank rear surface 20d, and a pair of tank side surfaces (not shown).

A liquid supply port 20h is formed in the tank upper surface 20 a. A filler 22 is provided to project upward from the liquid supply port 20 h. A liquid level regulating member 24 is provided at the liquid supply port 20h so as to project into the urea water tank 20. When replenishing the urea water tank 20 with urea water, the filler 22 guides the urea water to the liquid supply port 20h of the urea water tank 20. The filler 22 is screwed and fastened to the case upper surface 20a by a fixing screw 22 c. A strainer 28 is screwed and fixed to the upper end of the filler 22 by a fixing screw 28 a. A filler cap 23 is detachably provided at an upper opening of the strainer 28. The strainer 28 has a filter 28A. The filter 28A has a substantially cylindrical shape having an outer diameter smaller than an inner diameter of the filler 22, and is disposed in the cylinder of the filler 22. The filter 28A removes foreign substances contained in the urea water injected from the upper opening of the strainer 28. This can suppress the mixing of foreign substances into the urea water tank 20 by the filter 28A. The liquid level regulation member 24 guides the urea water into the urea water tank 20, and regulates the height position of the liquid level of the urea water replenished into the urea water tank 20. The urea water is supplied from the liquid supply port 20h into the urea water tank 20 through the filler 22 and the liquid level regulating member 24. The details of the filler 22 and the liquid level regulating member 24 will be described later with reference to fig. 7 and 8.

A drain plug 27 is provided on the bottom surface 20b of the urea water tank 20. The drain plug 27 is removed when discharging the urea water remaining in the urea water tank 20.

The tank upper surface 20a of the urea water tank 20 is provided with pipe attachment ports 20i1 and 20i 2. The pipe attachment port 20i1 is connected to the urea solution hose 69 inside the urea solution tank 20, and the urea solution hose 69 outside the urea solution tank 20 is connected thereto. Actually, 2 pipe attachment ports 20i1 are provided on the tank upper surface 20a, a urea water hose 69 for taking out urea water from the urea water tank 20 is connected to one of the pipe attachment ports 20i1, and a urea water hose 69 for returning urea water to the urea water tank 20 is connected to the other pipe attachment port 20i 1. The pipe attachment port 20i2 is connected to the cooling water hose 80 inside the urea water tank 20, and the cooling water hose 80 outside the urea water tank 20 is connected thereto. Actually, 2 pipe attachment ports 20i2 are provided on the tank upper surface 20a, one of the pipe attachment ports 20i2 is used for discharging the cooling water circulated in the urea water tank 20 from the cooling water hose 80 in the urea water tank 20, and the other pipe attachment port 20i2 is used for feeding the cooling water circulated in the urea water tank 20 to the cooling water hose 80 in the urea water tank 20.

The remaining urea solution amount sensor 74 detects the position of the liquid surface directly below the pipe attachment port 20i 1. The urea solution hose 69 extends from the pipe attachment port 20i1 directly downward, and sucks the urea solution in the center of the bottom portion 20 b. A wiring 74a is connected to the remaining urea solution amount sensor 74, and the wiring 74a is led out from the tank upper surface 20a of the urea solution tank 20 to the outside and is connected to the exhaust controller 75 via a relay bracket 78 (see fig. 5) fixed to the front surface of the fuel tank 19.

The 2 nd part 82 of the cooling water hose 80 extends from the pipe attachment ports 20i1 and 20i2 directly downward, is bent substantially at a right angle near the bottom surface 20b, and extends along the bottom surface 20 b.

The urea quality sensor 25 is provided in a portion of the 2 nd portion 82 of the cooling water hose 80 near the tank bottom surface 20 b. A wiring 25a is connected to the urea quality sensor 25, and the wiring 25a is led out from the tank upper surface 20a of the urea water tank 20 to the outside and is connected to an exhaust controller 75 via a relay bracket 78 (see fig. 5) fixed to the front surface of the fuel tank 19.

In the present embodiment, the urea quality sensor 25 is disposed at an end portion of a pipe (the 2 nd portion 82 of the cooling water hose 80) through which an antifreeze for thawing the urea water in the urea water tank 20 flows. This allows the liquefied urea solution to be present around the urea quality sensor 25 at all times, and therefore the quality of the urea solution can be measured stably.

As shown in fig. 6 (and fig. 8 and 9 described later), the full water position a2 of the remaining urea water level sensor 74 and the liquid level gauge 26, which is regarded as full water, is located slightly below the liquid level limit position a1 described later with reference to fig. 8. Accordingly, the full water can be detected by the remaining urea solution amount sensor 74 and the liquid level gauge 26 before the urea solution reaches the liquid level limiting position a1, and therefore, a problem that the full water cannot be detected at any time can be avoided. The full water position a2 may be the same position as the liquid surface limit position a 1.

Next, details of the filler 22 and the liquid level regulating member 24 will be described with reference to fig. 7 and 8. Fig. 7 is an exploded perspective view of the filler 22 and the liquid level regulating member 24. Fig. 8 is an enlarged sectional view of the packing 22 and the mounting portion of the liquid level regulating member 24 in the urea water tank 20. As shown in fig. 7 and 8, the filler 22 is a cylindrical member provided to protrude upward from a liquid supply port 20h formed in a tank upper surface 20a of the urea water tank 20. The liquid surface regulating member 24 is a cylindrical member provided to protrude from the liquid supply port 20h into the tank.

The filler 22 is formed using a relatively hard material (e.g., metal, resin, etc.). For example, in the present embodiment, the filler 22 is formed using PA66+ GF30 (polyamide resin 66%, glass fiber 30%, and other 4%). The strength of the filler 22 is thus higher than the strength of the urea water tank 20. For example, the urea water tank 20 is formed using MDPE (medium density polyethylene) having a strength lower than that of the filler 22. As shown in fig. 7, ribs 22e for increasing the strength of the main body portion 22a are provided on the front portion, the left side portion, and the right side portion of the outer peripheral surface of the main body portion 22a, respectively. Each rib 22e is a plate-like portion standing from the upper surface of the base portion 22 b. In this way, the filler 22 is a portion directly touched by the worker who performs the replenishment work, and therefore has a shape and a material having higher strength.

The filler 22 includes a main body 22a and a base 22 b. The body portion 22a is a cylindrical portion that guides the urea water to the liquid supply port 20 h. The main body portion 22a includes a1 st segment 22a1 extending vertically upward from the liquid supply port 20h and a2 nd segment 22a2 extending obliquely upward and forward from an upper end of the 1 st segment. That is, the filler 22 has a forward bent shape so that the urea solution can be easily supplied in a state where the vertical plate portion 49 located forward is opened.

As shown in fig. 7, a vent hole 22f protruding outward is provided in the rear portion of the outer peripheral surface of the body portion 22 a. A hose (not shown) is connected to the vent port 22f, and a breather pipe filter (not shown) is connected to the hose. This allows the vent port 22f to open the interior of the urea water tank 20 to the atmosphere, and to suppress the entry of foreign substances into the urea water tank 20.

The base portion 22b is a portion that is enlarged outward from the outer peripheral edge portion of the body portion 22a in the lower end portion of the body portion 22 a. The base portion 22b is formed with a plurality of through holes 22ba penetrating the base portion 22b in the vertical direction. The plurality of through holes 22ba of the base portion 22b are respectively penetrated by fixing screws 22c, and the filler 22 is screwed and fixed to the case upper surface 20a by the fixing screws 22 c.

A recess 22d recessed upward in an annular shape is formed in the bottom surface of the base portion 22b around the lower opening 22g of the body portion 22 a. The recess portion 22d has an inner diameter larger than the outer diameter of the flange portion 24b so as to be able to accommodate the flange portion 24b of the liquid level regulating member 24. Thus, when the filler 22 is attached to the tank upper surface 20a of the urea water tank 20, the recess 22d forms a space for accommodating the flange portion 24b of the liquid level regulating member 24 between the bottom surface of the base portion 22b of the filler 22 and the tank upper surface 20a of the urea water tank 20.

A plurality of weight-reduced portions 22k are formed in the bottom surface of the base portion 22b around the recess 22d in an aligned manner on the same circumference. Each of the plurality of weight-reduced portions 22k is a portion recessed upward with respect to the bottom surface of the base portion 22 b. Each of the plurality of weight-reduced portions 22k is provided mainly for suppressing the occurrence of sink marks (depressions, dents, and the like due to material shrinkage) in the base portion 22b when the padding 22 is manufactured. That is, by forming the plurality of weight reducing portions 22k in the base portion 22b, occurrence of a sink mark is suppressed, and thus occurrence of a trouble such as water leakage in a joint portion between the base portion 22b and the tank upper surface 20a of the urea water tank 20 can be suppressed.

A flange 22h is provided at the upper end of the body 22 a. The flange 22h is a plate-like portion that is enlarged outward from the outer peripheral edge of the main body portion 22 a. A plurality of receiving portions 22j are provided in the flange 22 h. Each of the accommodating portions 22j is a space having an open upper portion, and a nut is accommodated in the space. That is, a plurality of nuts are embedded in the flange 22 h.

When the strainer 28 is attached to the upper end portion of the filler 22, a plurality of fixing screws 28a penetrating the flange portion of the strainer 28 are screwed into a plurality of nuts fitted into the flange 22h, respectively, in a state where the bottom surface of the flange portion provided at the lower end portion of the strainer 28 is in close contact with the surface of the flange 22 h. Thereby, the strainer 28 is screwed and fixed to the flange 22 h.

A plurality of ribs 22i are provided on the bottom surface of the flange 22 h. The plurality of beads 22i are plate-shaped portions that connect the bottom surface of the flange 22h and the main body portion 22a or the bead 22 e. The plurality of ribs 22i are provided mainly for improving the flatness of the flange 22 h.

The liquid surface regulating member 24 is provided to protrude downward into the urea water tank 20 from the liquid supply port 20 h. The liquid surface regulating member 24 has a cylindrical portion 24a and a flange portion 24 b. The tube portion 24a is a cylindrical portion provided to penetrate the liquid supply port 20 h. The cylindrical portion 24a guides the urea water to the inside of the urea water tank 20, and restricts the height position of the liquid surface of the urea water replenished into the urea water tank 20.

The flange portion 24b is an annular and plate-like portion that is provided at the upper end of the tube portion 24a so as to extend outward from the outer peripheral edge of the tube portion 24 a. The flange portion 24b is disposed along the peripheral edge portion of the liquid supply port 20h on the tank upper surface 20a of the urea water tank 20. When the filler 22 is attached to the case upper surface 20a, the flange portion 24b is accommodated in the recess 22d formed in the bottom surface of the base portion 22b of the filler 22. Here, the thickness of the flange portion 24b is larger than the depth of the recess portion 22 d. Further, as described later, the liquid surface regulating member 24 is an elastic body, and therefore the flange portion 24b has elasticity. Thus, the flange portion 24b is moderately compressed by the upper wall surface of the recess portion 22d of the base portion 22b and the tank upper surface 20a of the urea water tank 20 in the recess portion 22 d. As a result, the flange portion 24b is firmly adhered to the upper wall surface of the recess 22d in the base portion 22b and the tank upper surface 20a of the urea water tank 20, and the periphery of the liquid supply port 20h can be more reliably sealed so that the urea water does not leak from the periphery of the liquid supply port 20h to the outside of the urea water tank 20.

The worker removes the filler cap 23 from the filler 22 and injects urea water from the upper opening of the filler 22. Thereby, the urea water is replenished into the urea water tank 20 through the filler 22 and the liquid level regulating member 24.

The height position of the liquid surface of the urea water in the urea water tank 20 is regulated to a predetermined liquid surface regulation position a1 (see fig. 8) by the liquid surface regulation member 24. Thus, for example, even when the urea water in the urea water tank 20 freezes and expands, the urea water tank 20 can be prevented from being damaged by the expansion. Specifically, if air is not present in the urea water tank 20, the urea water freezes and expands in volume, and the urea water tank 20 also expands, so that the urea water tank 20 may be damaged. Therefore, by limiting the height position of the liquid surface of the urea water, a sufficient upper space is secured in consideration of the amount of expansion of the urea water, and even when the urea water freezes and expands, the urea water expands in the upper space, so that the urea water tank 20 can be prevented from being expanded and damaged.

When the urea solution is supplied to the liquid surface restricting position a1 in the urea water tank 20, the lower end 24c of the cylindrical portion 24a of the liquid surface restricting member 24 is blocked by the urea solution. Accordingly, the air in the urea water tank 20 cannot escape to the outside through the liquid level regulation member 24, and therefore the liquid level of the urea water does not rise above the liquid level regulation position a 1. Therefore, when manufacturing the liquid level regulating member 24, the length of the cylindrical portion 24a of the liquid level regulating member 24 needs to be set to a size corresponding to the distance from the liquid supply port 20h to the liquid level regulating position a 1. When the urea aqueous solution is continuously replenished even though the liquid surface of the urea aqueous solution has reached the liquid surface regulation position a1, the liquid surface of the urea aqueous solution rises in the cylinder of the cylinder portion 24a of the liquid surface regulation member 24.

Here, the liquid surface regulating member 24 is formed using an elastic material. For example, in the present embodiment, the liquid surface regulating member 24 is formed using EPD M (ethylene propylene diene monomer) having resistance to urea water as an example of the elastic material. However, the liquid level regulating member 24 is not limited to this, and may be formed using another elastic material. In this case, it is preferable to use a material that is elastically deformable at least when pushed by the liquid surface frozen by the urea aqueous solution and has resistance to the urea aqueous solution for the liquid surface regulating member 24.

Thus, when the urea solution freezes and expands in the urea solution tank 20 and the lower end portion is pushed by the liquid surface where the urea solution freezes, the liquid surface regulating member 24 is elastically deformed such that, for example, the liquid surface is squashed in the vertical direction and the mid-abdominal portion expands outward. Thereby, the liquid surface regulating member 24 can absorb the load applied from the liquid surface on which the urea aqueous solution freezes. Therefore, the liquid surface regulating member 24 can suppress the load applied from the liquid surface on which the urea water freezes from being applied to the packings 22 via the liquid surface regulating member 24, and therefore, the damage of the packings 22 and the decrease in the sealing performance of the installation surface of the packings 22 can be suppressed. When the pushing due to the liquid level frozen by the urea solution is eliminated, the liquid level regulating member 24 returns to the original non-elastically deformed state (i.e., the state in which the lower end position is located at the liquid level regulating position a 1) by its own elastic force, and can regulate the liquid level of the urea solution to the liquid level regulating position a 1.

As shown in fig. 8, the inner diameter of the lower opening 22g of the body portion 22a of the filler 22 is smaller than the inner diameter of the upper opening of the tube portion 24a of the liquid surface regulating member 24. Accordingly, even when an attachment error of the filler 22 occurs because the inner diameter of the through hole 22ba is larger than the screw diameter of the fixing screw 22c when the filler 22 is attached to the upper portion of the urea water tank 20, the lower opening 22g of the main body portion 22a of the filler 22 falls within the range of the upper opening of the cylindrical portion 24a of the liquid surface regulating member 24.

As described above, the shovel 100 according to the embodiment of the present invention includes the upper slewing body 2, the diesel engine 8 mounted on the upper slewing body 2, the slewing frame 31 constituting a part of the upper slewing body 2, the urea water tank 20 mounted on the slewing frame 31, the filler 22 attached to the upper part of the urea water tank 20, and the liquid level regulating member 24 positioned below the filler 22, and the liquid level regulating member 24 is formed using an elastic material.

As a result, in the shovel 100 according to the embodiment of the present invention, when the lower end portion of the liquid surface regulating member 24 is pushed by the liquid surface where the urea water freezes, the liquid surface regulating member 24 elastically deforms, and thereby the load applied from the liquid surface where the urea water freezes can be absorbed. Therefore, according to the shovel 100 according to the embodiment of the present invention, the loader 22 can be prevented from being pushed up due to freezing of the liquid reducing agent such as urea water.

In the shovel 100 according to the embodiment of the present invention, the liquid level regulating member 24 has a flange portion 24b at an upper end portion thereof for sealing the installation surface of the urea water tank 20 and the filler 22.

Accordingly, the shovel 100 according to the embodiment of the present invention can seal the installation surface of the urea water tank 20 and the filler 22 without providing a separate sealing member such as an O-ring. Therefore, according to the shovel 100 according to the embodiment of the present invention, it is possible to improve the ease of installing the fillers 22 and reduce the cost of the installation portion of the fillers 22.

In the shovel 100 according to the embodiment of the present invention, the lower end position of the liquid level regulating member 24 is the liquid level regulating position a 1.

As a result, in the shovel 100 according to the embodiment of the present invention, when the urea solution in the urea solution tank 20 freezes, the liquid level regulating member 24 is highly likely to be pushed up by the frozen liquid level of the urea solution. Therefore, in the shovel 100 according to the embodiment of the present invention, the liquid level regulating member 24 is particularly useful in a structure that can be elastically deformed.

The shovel 100 according to an embodiment of the present invention further includes a remaining urea solution level sensor 74, and the full water level in the level gauge 26 is the same as the liquid level limit position a1 or is lower than the liquid level limit position a 1.

Accordingly, the shovel 100 according to the embodiment of the present invention can detect the full water with the level gauge 26 before the urea water reaches the liquid level limiting position a1, and therefore, the trouble that the full water cannot be detected at any time can be avoided.

(modification example)

Next, a modification of the shovel 100 will be described with reference to fig. 9. Fig. 9 is a longitudinal sectional view of the urea water tank 20 in the excavator 100 according to the modification. As shown in fig. 9, the shovel 100 according to the present modification includes a urea water tank 20A having a shape different from that of the urea water tank 20 shown in fig. 6. Specifically, the urea water tank 20A is different from the urea water tank 20 shown in fig. 6 in a point having an inclined surface 20g and a point where the liquid supply port 20h, the filler 22, and the liquid level regulation member 24 are provided on the inclined surface 20 g. The filler 22 is screwed and fixed to the inclined surface 20g by a fixing screw 22 c. The inclined surface 20g is formed at the front upper portion of the urea water tank 20A. The inclined surface 20g is inclined so as to incline rearward (negative X-axis direction) as it goes upward (positive Z-axis direction).

A liquid level gauge 26 (an example of a "liquid level gauge") is provided on the inclined surface 20 g. The liquid level meter 26 displays the level (liquid level) of the urea water in the urea water tank 20A. Therefore, the operator can prevent the urea solution from overflowing by replenishing the urea solution while observing the level gauge 26.

As shown in fig. 9, the packing 22 and the liquid surface regulating member 24 are provided on the inclined surface 20g, and thus extend in a direction perpendicular to the inclined surface 20g (i.e., inclined). Therefore, as shown in fig. 9, the cylindrical portion 24a of the liquid surface regulating member 24 is inclined with respect to the liquid surface of the urea water in the urea water tank 20A. In this case, as shown in fig. 9, the liquid surface regulating position a1 is the highest position in the lower end portion 24c of the cylindrical portion 24a of the liquid surface regulating member 24.

In the present modification, the liquid surface regulating member 24 is also formed using an elastic material. Thus, in the present modification, the liquid surface regulating member 24 is elastically deformed, for example, to be bent upward or bent upward, when the urea solution freezes and expands in the urea solution tank 20A and the lower end portion is pushed by the liquid surface on which the urea solution freezes. Thereby, the liquid surface regulating member 24 can absorb the load applied from the liquid surface on which the urea aqueous solution freezes. Therefore, the liquid surface regulating member 24 can suppress the load applied from the liquid surface on which the urea water freezes from being applied to the packings 22 via the liquid surface regulating member 24, and therefore, the damage of the packings 22 and the decrease in the sealing performance of the installation surface of the packings 22 can be suppressed. When the pushing due to the frozen liquid surface of the urea solution is eliminated, the liquid surface regulating member 24 returns to the original non-elastically deformed state (i.e., the linear state) by its own elastic force, and can regulate the liquid surface of the urea solution at the liquid surface regulating position a 1.

In addition, as shown in fig. 9, in the present modification, since the inner diameter of the lower opening of the filler 22 is smaller than the inner diameter of the upper opening of the cylindrical portion 24a of the liquid surface regulating member 24, even when an attachment error of the filler 22 occurs, the lower opening of the filler 22 can be made to fall within the range of the upper opening of the cylindrical portion 24a of the liquid surface regulating member 24.

As described above, the liquid level regulation member 24 according to the embodiment of the present invention can regulate the height position of the liquid level of the urea water in the urea water tank 20A when provided on either the tank upper surface 20A or the inclined surface 20g of the urea water tank 20A, and can absorb the load applied from the liquid level of the frozen urea water when the urea water in the urea water tank 20A freezes.

The present embodiment has been described above with reference to specific examples. However, the present invention is not limited to these specific examples. Appropriate design changes to such specific examples by those skilled in the art are also included in the scope of the present invention as long as the characteristics of the present invention are provided. The elements, the arrangement, conditions, shapes, and the like of the specific examples described above are not limited to the examples shown in the drawings, and can be modified as appropriate. The combination of the elements included in the specific examples described above can be changed as appropriate as long as no technical contradiction occurs.

For example, the shape of the cylindrical portion 24a of the liquid surface regulating member 24 is not limited to the cylindrical shape shown in the embodiment. For example, the cylindrical portion 24a may have a truncated cone shape in which the opening diameter gradually decreases as it goes downward. This reduces the contact area with the frozen liquid surface of the cylinder 24a, and further reduces the load applied from the liquid surface. For example, the cylindrical portion 24a may have a truncated cone shape in which the opening diameter gradually increases as it goes downward. In this case, the cylindrical portion 24a can be elastically deformed so that the inclined surface is deflected upward, and the load applied from the liquid surface on which the urea water freezes can be further absorbed by this deflection. In this case, the liquid surface regulating member 24 can be formed using an elastic material having at least a relatively high strength (for example, a thin metal material, a resin material, or the like) as long as it can be elastically deformed.

In the present invention, the "elastic body" is not limited to being formed using an elastic material, and includes a structure that can be elastically deformed.

Claims (5)

1. A shovel is provided with:

an upper slewing body;

an engine mounted on the upper slewing body;

a revolving frame constituting a part of the upper revolving structure;

a tank for a liquid reducing agent mounted on the revolving frame; and

a filler attached to an upper portion of the tank for a liquid reducing agent,

the shovel is characterized by further comprising:

a liquid level limiting component positioned below the filler,

the liquid level regulating member is an elastic body.

2. The shovel of claim 1,

the liquid surface regulating member seals an installation surface between the liquid reducing agent tank and the filler.

3. The shovel of claim 2,

the liquid level regulating member has a flange portion at an upper end portion thereof for sealing the installation surface.

4. The shovel of any one of claims 1 to 3,

the lower end position of the liquid level limiting component is a liquid level limiting position.

5. The shovel of claim 4,

and a liquid level meter is also arranged on the device,

the full water level in the level gauge is the same as or lower than the liquid level limit position.

Images