JP2015028318A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage etc. of a tank for a liquid reducer and peripheral components even if the liquid reducer is frozen and expands under a lower temperature environment.SOLUTION: A construction machine includes: a tank 10 for a liquid reducer which stores urea water (the liquid reducer) and is formed by a resin; and a tank housing container 12 which houses the tank 10 for the liquid reducer. Opening parts OP1 to OP4, which allow deformation of the tank 10 for the liquid reducer, are provided in a portion of the tank housing container 12 where the tank 10 for the liquid reducer deforms in conjunction with cubic volume change of the urea water when the urea water is frozen to increase its cubic volume.

Description

  The present invention relates to a construction machine having a tank in which a liquid reducing agent is stored.

  In recent years, construction equipment such as hydraulic excavators equipped with diesel engines has been installed with exhaust gas treatment equipment in the exhaust system of diesel engines to meet higher-level exhaust gas regulations. Is released into the atmosphere through the NOx reduction catalyst provided in

  Conventionally, as this type of exhaust gas treatment apparatus, a urea selective reduction type NOx treatment apparatus using a urea aqueous solution (liquid reducing agent) has been often adopted, and the urea aqueous solution is generally stored in a resin-made liquid reducing agent tank. ing. Further, the liquid reducing agent tank is connected to the exhaust pipe by a liquid reducing agent supply pipe, and is configured so that the urea aqueous solution in the liquid reducing agent tank can be supplied to the exhaust pipe by the liquid reducing agent supply pump (for example, Patent Document 1).

JP 2003-20936 A

  However, when the liquid reducing agent tank is installed on the upper swing body, it is necessary to appropriately protect the liquid reducing agent tank from vibration. In particular, since construction machines often perform operations in harsh environments, when the liquid reducing agent tank is directly fixed to the upper rotating body with, for example, bolts, the fixing portion of the liquid reducing agent tank may be damaged. .

  Further, the liquid reducing agent (for example, urea aqueous solution) in the liquid reducing agent tank freezes and expands in a low temperature environment, but when the liquid reducing agent tank is deformed during the expansion, the liquid reducing agent tank There is also a risk of damage and interference with surrounding parts.

  An exemplary object of an aspect of the present invention is to provide a construction machine that can prevent damage to a liquid reducing agent tank and its peripheral components.

According to one aspect of the invention,
A liquid reducing agent tank formed of resin and storing the liquid reducing agent;
A tank storage container for storing the liquid reducing agent tank therein,
A deformation permitting portion for allowing deformation of the liquid reducing agent tank is provided at a portion of the tank storage container where the liquid reducing agent tank deforms when the liquid reducing agent expands.

  According to an aspect of the present invention, even if the liquid reducing agent freezes and expands in a low temperature environment, damage to the liquid reducing agent tank and its peripheral parts can be prevented.

FIG. 1 is a side view showing a hydraulic excavator as an example of a construction machine according to an embodiment. FIG. 2 is a plan view schematically showing the upper swing body of the construction machine. FIG. 3 is an enlarged perspective view showing the vicinity of the arrangement position of the liquid reducing agent tank of the construction machine. FIG. 4 is a perspective view of the liquid reducing agent tank as viewed from the left front. FIG. 5 is an exploded perspective view of the liquid reducing agent tank as viewed from the right front. FIG. 6 is a perspective view of the liquid reducing agent tank as viewed from below. 7A and 7B are image diagrams for explaining the expansion of the liquid reducing agent tank. FIG. 7A is a diagram illustrating a state before expansion, and FIG. 7B is a diagram illustrating a state after expansion.

  Reference will now be made to non-limiting exemplary embodiments of the invention with reference to the accompanying drawings.

  In the description of all attached drawings, the same or corresponding members or parts are denoted by the same or corresponding reference numerals, and redundant description is omitted.

  Also, the drawings are not intended to show relative ratios between members or parts unless otherwise specified. Accordingly, specific dimensions can be determined by one skilled in the art in light of the following non-limiting embodiments.

  Further, the embodiments do not limit the invention, but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  FIG. 1 shows a construction machine according to an embodiment of the present invention. In the present embodiment, a hydraulic excavator will be described as an example of a construction machine. However, the present invention can be applied to other construction machines as long as it has a liquid reducing agent tank.

  In the construction machine, an upper swing body 2 is swingably mounted on an upper portion of the lower traveling body 1, and a cab 3 is provided on one front side of the upper swing body 2. A boom 4 is pivotally attached to the front center portion of the upper swing body 2 so as to be able to be raised and lowered. Further, a bucket 6 is attached to the tip of the arm 5 so as to be rotatable up and down.

  FIG. 2 is a plan view schematically showing a rear portion of the upper swing body.

  As shown in FIG. 2, an engine room 7 is formed at the rear of the upper swing body 2, and a diesel engine 8 is installed in the engine room 7. A cooling fan 8b is provided on the right side (arrow Y1 direction side in the figure) of the diesel engine 8, and a heat exchanger including a radiator or the like is located on the right side (arrow Y1 direction side in the figure) of the cooling fan 8b. A unit 13 is installed.

  Further, an exhaust pipe 8a is connected to the diesel engine 8, and nitrogen oxide (hereinafter referred to as NOx) in the engine exhaust gas is purified on the downstream side of the exhaust pipe 8a in order to comply with higher-order exhaust gas regulations. An exhaust gas treatment device 9 is installed.

  As the exhaust gas treatment device 9, a urea selective reduction type NOx treatment device using urea water as a liquid reducing agent is adopted. This exhaust gas treatment device 9 injects urea water upstream of a reduction catalyst (not shown) provided in the exhaust pipe 8a to reduce NOx in the exhaust gas, and promotes this reduction reaction by the reduction catalyst to reduce NOx. It is configured to detoxify.

  Therefore, the construction machine provided with this type of exhaust gas treatment device 9 is provided with a liquid reducing agent tank 10 (hereinafter referred to as a urea water tank) for storing urea water (liquid reducing agent).

  FIG. 3 is a partially enlarged perspective view showing the vicinity of the installation position of the urea water tank 10.

  As shown in FIG. 3, a pair of left and right boom mounting support brackets 17 </ b> L and 17 </ b> R are erected on the front portion of the revolving frame 14 of the upper revolving structure 2. The boom foot pin 18 is inserted into and removed from holes 172L and 172R formed in the support brackets 17L and 17R. Further, the urea water tank 10 is disposed on the outer side portion of the support bracket 17L. Note that a fuel tank and a sump tank may be disposed in the vicinity of the urea water tank 10.

  The urea water tank 10 is a resin container, and urea water is stored therein. The urea water tank 10 is connected to the exhaust pipe 8a via a urea water supply pipe and an injector (not shown). Therefore, the urea water in the urea water tank 10 is injected from the injector to the exhaust pipe 8a through the urea water supply pipe.

  4 to 6 are diagrams illustrating specific configuration examples of the urea water tank 10.

  4 is a perspective view of the liquid reducing agent tank 10 as viewed from the left front, and FIG. 5 is an exploded perspective view of the liquid reducing agent tank 10 with the filler 30 removed as viewed from the right front. FIG. 3 is a perspective view of the liquid reducing agent tank 10 as viewed from below.

  In the following description, the front side (side in the direction of the arrow X2 in the figure) close to the operator side is referred to as the front and the back side (in the figure in the figure) when the urea solution is replenished in the liquid reducing agent tank 10 as necessary. The arrow X1 direction side) may be referred to as the rear. In addition, the direction indicated by the arrow Y1 in the figure orthogonal to the front-rear direction may be referred to as the right side, and the direction indicated by the arrow Y2 in the figure may be referred to as the left side.

  The urea water tank 10 is made of resin, and has a tank body 10a having a substantially rectangular cross section and a substantially box shape as a whole. An inclined surface 10b is formed in the upper front portion of the tank body 10a. The inclined surface 10b is inclined so as to fall backward as it goes upward.

  The inclined surface 10b is provided with a liquid supply port 10d (see FIG. 5). A filler 30 described later is detachably attached to the liquid supply port 10d. The urea water is replenished into the tank body 10a from the liquid supply port 10d through the filler 30 at the time of replenishment.

  Further, a level gauge 28 is provided on the inclined surface 10b. The level gauge 28 displays the level (liquid level height) of urea water in the tank body 10a. Therefore, during the urea water replenishment process, the urea water can be prevented from overflowing by the operator replenishing the urea water while looking at the level gauge 28.

  Further, a concave portion 10c is formed on the right side of the inclined surface 10b. The concave portion 10 c functions as a grip portion (handle) when the urea water tank 10 is attached to and detached from the tank reinforcing member 15.

  A drain plug 11 is provided at the bottom 10g of the urea water tank 10 (see FIG. 6). The drain plug 11 is a plug that is removed when the urea water remaining in the urea water tank 10 is drained.

  Further, a filler 30 is attached to the urea water tank 10. The filler 30 guides urea water to the liquid supply port 10d of the urea water tank 10 during replenishment. The filler 30 includes a filler body 30a, a filler tube 33, a filler cap 35, and the like.

  The filler main body 30a is a cylindrical member, and is formed of a metal or other material (for example, resin). The filler body 30a is attached to the filler bracket 31 by welding or bonding. At this time, the substantially central position of the cylindrical filler body 30 a is fixed to the filler bracket 31. Therefore, in a fixed state, one end of the filler body 30a protrudes outside the filler bracket 31 to form an inner protrusion, and the other end protrudes inward to form an inner protrusion.

  A screw is formed on the outer periphery of the outer protrusion of the filler body 30a. The filler cap 35 is detachably attached to the outer protrusion of the filler body 30a.

  One end of the filler tube 33 is attached to the inner protruding portion of the filler body 30a. The other end of the filler tube 33 is attached to the liquid supply port 10 d of the urea water tank 10.

  The filler 30 having the above configuration is attached to the urea water tank 10 using a filler bracket 31. The filler bracket 31 is a plate-like member and is formed of metal or other material (for example, resin).

  Further, the urea water tank 10 is formed with an upper attachment portion 10e and a lower attachment portion 10f. The upper mounting portion 10e is formed on the upper surface portion of the tank body 10a. The lower mounting portion 10f is formed at a lower position of the liquid supply port 10d on the inclined surface 10b.

  A screw hole 10h is formed in the upper attachment portion 10e and the lower attachment portion 10f. The positions where the screw holes 10 h are formed are configured to correspond to the positions of the filler mounting bolts 32 when the filler bracket 31 is mounted on the urea water tank 10.

  The filler bracket 31 is fixed to the urea water tank 10 by screwing the filler mounting bolt 32 into the screw holes 10h of the mounting portions 10e and 10f, whereby the filler 30 is also attached to the urea water tank 10.

  The urea water is replenished in a state where the filler 30 is attached to the urea water tank 10. In order to replenish urea water, the filler cap 35 is removed from the filler body 30a, and urea water is injected from the outer end of the filler body 30a. Thereby, urea water is replenished to the urea water tank 10 through the filler tube 33.

  The resin-made urea water tank 10 having the above configuration is stored in a tank storage container 12. The tank storage container 12 includes a tank reinforcing member 15 and a tank bracket 26. Hereinafter, the tank storage container 12 will be described.

  First, the tank reinforcing member 15 will be described.

  As shown in FIGS. 4 to 6, the tank reinforcing member 15 includes a side reinforcing plate 15 </ b> A, an upper reinforcing plate 15 </ b> B, a tank mounting plate 15 </ b> C, and the like. Each plate 15A-15C which comprises this tank reinforcement member 15 is formed, for example by metal materials, such as iron, or other materials (material with higher intensity | strength than the material of the urea water tank 10).

  The side reinforcing plate 15A extends in the vertical direction (Z1 and Z2 directions in the figure) and has an L shape in plan view. The side reinforcing plates 15 </ b> A are arranged at positions facing the four corners of the urea water tank 10, and hold the four corner positions of the urea water tank 10.

  The upper reinforcing plate 15B connects the upper portions of the adjacent side reinforcing plates 15A. Thereby, the upper part of the side reinforcing plate 15A is fixed by the upper reinforcing plate 15B. At this time, the upper reinforcing plate 15B is fixed so as to be positioned outside the side reinforcing plates 15A. This reason will be described later for convenience of explanation.

  The tank mounting plate 15C serves as a base on which the urea water tank 10 is mounted. Further, the lower end portion of the side reinforcing plate 15A is fixed to the tank mounting plate 15C.

  A plug opening 15E is formed in the tank mounting plate 15C. When the urea water tank 10 is attached to the tank reinforcing member 15, the drain plug 11 is inserted into the plug opening 15E and protrudes downward from the lower surface of the tank mounting plate 15C.

  A lower reinforcing plate 15D is disposed on the lower surface of the tank mounting plate 15C. The lower reinforcing plate 15D is provided so as to extend in the longitudinal direction of the tank mounting plate 15C (the directions of arrows Y1 and Y2 in FIG. 4). The lower reinforcing plate 15D is fixed to the revolving frame 14 using a fixing bolt 19, and thereby the tank reinforcing member 15 is fixed to the revolving frame 14.

  The joining of the respective plates 15A to 15D constituting the tank reinforcing member 15 can be performed using, for example, welding. Further, by joining the plates 15A to 15D to form the tank reinforcing member 15, an opening OP is formed between the adjacent side reinforcing plates 15A.

  Specifically, an opening OP1 is formed in front of the tank reinforcing member 15, an opening OP2 is formed on the right, and an opening OP3 is formed on the left. Although not shown, an opening OP4 is also formed on the back surface of the tank reinforcing member 15.

  Next, the tank bracket 26 will be described.

  The tank bracket 26 is attached to the upper part of the urea water tank 10 attached to the tank reinforcing member 15. The bracket 26 is fixed to the tank reinforcing member 15 using bolts 27.

  Specifically, a bolt fastening block 27a is formed by welding or the like on the side reinforcing plate 15A and the upper reinforcing plate 15B located in the front. The bolt fastening block 27a is formed with a screw hole to be screwed with the tank fixing bolt 27. Further, the front end of the tank bracket 26 is provided with a hook-like portion 26d having an insertion hole (not shown in the figure) through which the tank fixing bolt 27 is inserted.

  Therefore, the tank bracket 26 is fixed to the tank reinforcing member 15 by inserting the tank fixing bolt 27 through the insertion hole formed in the hook-shaped portion 26d and fastening it to the bolt fastening block 27a. Thus, the liquid reducing agent tank 10 is stored in the tank storage container 12 with the bracket 26 fixed to the tank reinforcing member 15.

  The bracket 26 includes an upper portion 26 a extending in the horizontal direction and an inclined surface 26 b along the inclined surface 10 b of the urea water tank 10. The inclined surface 26b is held by pressing the inclined surface 10b of the urea water tank 10 from above while the liquid reducing agent tank 10 is stored in the tank storage container 12.

  Therefore, the tank 10 for liquid reductant is held in the tank reinforcing member 15 by the tank bracket 26 even if the tank reinforcing member 15 and the urea water tank 10 are not fixed using bolts or the like. The As a result, the liquid reducing agent tank 10 is securely held and reinforced by the tank storage container 12 (the tank reinforcing member 15 and the tank bracket 26).

  By the way, the construction machine equipped with the liquid reducing agent tank 10 may be placed in a low temperature environment. However, it is known that the urea water stored in the liquid reducing agent tank 10 freezes at -11 ° C or lower.

  When the urea water freezes, its volume increases compared to the liquid state, and accordingly, the liquid reducing agent tank 10 in which the urea water is stored is deformed so as to bulge outward.

  As described above, the liquid reducing agent tank 10 has a structure in which the inclined surface 10b, the liquid supply port 10d, the upper mounting portions 10e and 10f, and the like are formed on the upper side. For this reason, the upper part of the tank 10 for liquid reducing agents has a structure with many unevenness | corrugations and high rigidity.

  On the other hand, the tank main body 10a positioned below the liquid reducing agent tank 10 has a substantially rectangular cross section and a generally box shape as a whole. For this reason, the part (side surface part) excluding the four corner positions of the tank body 10a has a flat plate shape with less unevenness, and has a lower rigidity than the upper part. Therefore, when the urea water is frozen, the side surface portion of the tank body 10a is mainly deformed.

  Here, it is assumed that the liquid reducing agent tank 10 is accommodated in a tank reinforcing member that does not have openings on the four side walls. In this case, when the urea water freezes and the volume increases, a large pressing force is applied to the four side walls of the tank reinforcing member toward the outside due to the volume change of the frozen urea water. The member may be damaged.

  In contrast, in the present embodiment, openings OP (OP1 to OP4) are formed between adjacent side reinforcing plates 15A. At the position where the openings OP (OP1 to OP4) of the tank reinforcing member 15 are formed, the liquid reducing agent tank 10 is exposed, and therefore the liquid reducing agent tank 10 can be modified even if the urea water is frozen. It is made into the composition. That is, the openings OP (OP1 to OP4) formed in the tank reinforcing member 15 function as a deformation permitting portion that allows deformation of the liquid reducing agent tank 10 when the urea water is frozen.

  In addition, the opening OP (OP1 to OP4) of the tank reinforcing member 15 is configured to face the plane portion excluding the four corner positions of the tank body 10a. As described above, the flat surface portions other than the four corner positions of the tank body 10a have low rigidity, and the tank body 10a is likely to be greatly deformed when the urea water is frozen.

  In the present embodiment, the position of the opening OP (OP1 to OP4) formed in the tank reinforcing member 15 is set to a position opposite to a position where the tank body 10a is likely to be deformed when the urea water is frozen. Yes. Therefore, even if the urea water is frozen and the liquid reducing agent tank 10 is deformed, the deformation is performed in the opening OP (OP1 to OP4), and therefore the tank reinforcing member 15 can be prevented from being damaged. .

  Furthermore, in this embodiment, the upper reinforcement board 15B which connects the upper part of 15 A of adjacent side part reinforcement boards is comprised so that it may be located outside each side part reinforcement board 15A. This will be described with reference to FIG.

  FIG. 7 is an image diagram schematically showing the vicinity of the opening OP <b> 1 formed in front of the tank reinforcing member 15. 7A shows a state where the urea water is not frozen, and FIG. 7B shows a state where the urea water is frozen.

  As shown in FIG. 7A, an upper reinforcing plate 15B is disposed between adjacent side reinforcing plates 15A. The upper reinforcing plate 15B is disposed not on the back surface BA facing the tank body 10a (liquid reducing agent tank 10) of the side reinforcing plate 15A but on the outer surface SU opposite to the back surface BA.

  In the present embodiment, the upper reinforcing plate 15B is provided on the outer surface SU of the side reinforcing plate 15A. In other words, the upper reinforcing plate 15B is shifted forward (in the direction of the arrow X2) from the side reinforcing plate 15A by the thickness of the side reinforcing plate 15A (the dimension indicated by the arrow W in FIG. 7). .

  As shown in FIG. 7B, when the urea water is frozen and the volume is increased, the tank body 10a is also deformed (expanded) outward. At this time, in this embodiment, since a space (indicated by an arrow SP) is formed on the back side of the upper reinforcing plate 15B, the expansion portion EXP expands also in this space SP. Thereby, even if the tank main body 10a expand | swells, it can suppress that the force by expansion | swelling is applied to the upper reinforcement board 15B, and can prevent the tank reinforcement member 15 being damaged.

  Further, the upper reinforcing plate 15B is disposed at the upper end (the end in the arrow Z1 direction) of the side reinforcing plate 15A. That is, the upper reinforcing plate 15 </ b> B is disposed at a position near the upper portion of the liquid reducing agent tank 10.

  The upper portion of the liquid reductant tank 10 has a structure with many irregularities and high rigidity, and the expansion amount of the tank body 10a is small even if the raw water is frozen. Therefore, by arranging the upper reinforcing plate 15B at this position, even if the urea water freezes and the tank body 10a expands, it is possible to suppress this force from being applied to the upper reinforcing plate 15B. Can prevent damage.

  As described above, the tank bracket 26 is fixed to the tank reinforcing member 15 by using the tank fixing bolt 27, but the bolt fastening block 27a to which the tank fixing bolt 27 is fastened is also the side reinforcing plate 15A and the upper reinforcing plate 15B. It is provided in the upper position. That is, the fastening position of the tank fixing bolt 27 and the bolt fastening block 27 a is also set at a position close to the upper part of the liquid reducing agent tank 10.

  Therefore, even if the tank body 10a is deformed, the external force accompanying the deformation is not applied to the fastening portion of the tank fixing bolt 27 and the bolt fastening block 27a, and the tank bracket 26 and the tank reinforcing member 15 are kept fixed. To do. Therefore, the tank storage container 12 can be prevented from being damaged by setting the fastening positions of the tank fixing bolts 27 and the bolt fastening blocks 27a as in the present embodiment.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments described above, and various modifications are possible within the scope of the gist of the present invention described in the claims. It can be modified and changed.

  For example, the opening OP is not necessarily configured to expose the tank body 10a, and may be configured to be covered (closed) with a member that allows deformation of the tank body 10a.

  Further, in order to prevent deformation of the liquid reducing agent tank 10 during freezing of urea water, as shown in FIGS. 4 to 6, a configuration may be adopted in which ribs 10 i for increasing rigidity are provided on the tank body 10 a.

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper turning body 4 Boom 7 Engine room 8 Diesel engine 9 Exhaust gas treatment device 10 Urea water tank (liquid reducing agent tank)
10a Tank body 11 Drain plug 12 Tank storage container 13 Heat exchanger unit 14 Swivel frame 15 Tank reinforcement member 15A Side reinforcement plate 15B Upper reinforcement plate 15C Tank placement plate 15D Lower reinforcement plates 17L and 17R Support bracket 18 Boom foot pin 20 Protection Member 26 Tank bracket 30 Filler 31 Filler bracket EXP Expansion part OP, OP1-OP4 Opening part SP Space part

Claims (4)

A liquid reducing agent tank in which the liquid reducing agent is stored;
A tank storage container for storing the liquid reducing agent tank therein,
A construction machine characterized in that the tank housing container is provided with a deformation permitting part for allowing deformation of the liquid reducing agent tank accompanying a volume change of the liquid reducing agent. The liquid reducing agent tank has a box-shaped portion,
The tank storage container has support members that hold the four corner positions of the liquid reducing agent tank,
The construction machine according to claim 1, wherein the deformation permission portion is provided between the support members adjacent to each other.   The construction machine according to claim 1 or 2, wherein the tank container is exposed in the deformation permitting portion.   A connecting member for connecting the supporting members adjacent to the tank storage container is provided, and the connecting member is disposed on a surface opposite to the surface of the supporting member facing the liquid reducing agent tank. The construction machine according to claim 2.

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