JP6091992B2 - Construction machinery - Google Patents

Description

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

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

  Conventionally, as this kind of exhaust gas treatment apparatus, a urea selective reduction type NOx treatment apparatus using a urea aqueous solution (liquid reducing agent) is often adopted, and the urea aqueous solution is stored in a metallic liquid reducing agent tank. Further, the liquid reducing agent tank is connected to the exhaust pipe by a liquid reducing agent supply pipe, and the urea aqueous solution in the liquid reducing agent tank can be supplied to the exhaust pipe by the liquid reducing agent supply pump (Patent Document). 1).

JP 2003-20936 A

  By the way, in general, the liquid reducing agent tank is a resin tank and is attached to the revolving frame of the upper revolving structure. A drain plug is provided at the bottom of the liquid reducing agent tank for discharging urea water remaining during maintenance or the like from the tank. The drain plug has a structure protruding from the bottom of the liquid reducing agent tank.

  In conventional construction machines, an amber cover is provided on the lower surface of a revolving frame on which a liquid reducing agent tank is installed. However, depending on the work site, it is assumed that rocks or the like push up and deform the under cover. In this case, the undercover that has been pushed up and deformed hits the drain plug from under the swivel frame, and this impact may cause damage to the liquid reducing agent tank.

  One of the exemplary purposes of an embodiment of the present invention is to provide a construction machine that prevents the liquid reducing agent tank from being damaged.

According to one aspect of the invention,
A lower traveling body,
An upper swing body that is rotatably mounted on the lower traveling body;
A resin-made liquid reducing agent tank in which a liquid reducing agent is stored and a drain plug is provided at the bottom;
A construction machine having a mounting member on which the liquid reducing agent tank is mounted and an opening through which a drain plug is inserted;
Before placing member, said a protective member for protecting the drain plug and and constitutes a part of the tank reinforcing member for protecting by accommodating the tank the liquid reducing agent,
The tank reinforcing member is fixed to a swing frame of the upper swing body;
The bottom of the liquid reducing agent tank is covered by an under cover provided on the swivel frame of the upper swivel body;
The under cover is disposed below the protective member that protects the drain plug .

  According to an aspect of the present invention, since the drain plug is protected by the protective member, the liquid reducing agent tank can be prevented from being damaged.

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 an exploded perspective view of the liquid reducing agent tank as viewed from above. FIG. 5 is a perspective view of the liquid reducing agent tank as viewed from below. FIG. 6 is a view of the swivel frame to which the liquid reducing agent tank is attached as viewed from below, (A) is a perspective view showing a state in which the under cover is removed, and (B) is a view in which the under cover is attached. FIG. FIG. 7 is an enlarged front view showing the vicinity of the protective member. FIG. 8 is a diagram for explaining the rotation of the upper swing body and the position of the liquid reducing agent tank in association with each other. FIG. 8A is a diagram illustrating a state before the upper swing body is swung, and FIG. It is a figure which shows the state which the upper turning body turned.

  Next, embodiments of the present invention will be described with reference to the drawings.

  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 is applicable to other construction machines as long as it has a liquid reducing agent tank provided with a drain plug.

  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. Further, 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, and an arm 5 is connected to a tip end portion of the boom 4 so as to be vertically rotatable. 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 in front of the diesel engine 8, and a heat exchanger unit 13 including a radiator and the like is installed in front of the cooling fan 8b.

  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.

  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.

  The urea water tank 10 is surrounded by an outer cover (not shown) of the upper swing body 2. 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 and 5 are diagrams showing specific configuration examples of the urea water tank 10.

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

  The urea water tank 10 has a resin tank body 10a. An inclined surface 10b is formed in the upper front portion of the tank body 10a. The inclined surface 10b is inclined in such a manner that the inclined surface 10b falls backward as it goes upward.

  The inclined surface 10b is provided with a liquid supply port 10d. 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 a side portion 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. 5). The drain plug 11 is a plug that is removed when the urea water remaining in the urea water tank 10 is drained. As shown in FIG. 5, the drain plug 11 is provided so as to protrude from the bottom 10 g of the urea water tank 10.

  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. Specifically, a hole corresponding to the outer diameter of the filler main body 30 a is formed in the filler bracket 31, and the filler main body 30 a is fixed to the filler bracket 31 after the filler main body 30 a is inserted into the hole.

  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.

  The outer protruding portion of the filler body 30a has a screw formed on the outer periphery thereof. 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-described configuration is attached to the urea water tank 10 using the 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.

  Screw holes 12 are formed in the upper mounting portion 10e and the lower mounting portion 10f. The formation positions of the screw holes 12 correspond to the positions of the filler mounting bolts 32 when the filler bracket 31 is mounted on the urea water tank 10.

  By screwing the filler mounting bolt 32 into the screw holes 12 of the mounting portions 10e and 10f, the filler bracket 31 is fixed to the urea water tank 10, whereby the filler 30 is also attached to the urea water tank 10. FIG. 3 shows a state in which the filler 30 is 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 main body 30a from the state shown in FIG. 3, and urea water is injected from the outer end of the filler main 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 configured as described above is accommodated in the tank reinforcing member 15.

  As shown in FIGS. 4 and 5, the tank reinforcing member 15 includes a side reinforcing plate 15A, an upper reinforcing plate 15B, a tank mounting plate 15C, and a lower reinforcing plate 15D. Each plate 15A-15D 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 15A are arranged at positions facing the four corners 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.

  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 protruding from the bottom 10g is inserted into the plug opening 15E and protrudes downward from the lower surface of the tank mounting plate 15C (see FIG. 5). .

  Further, 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 (in the directions of arrows Y1, Y2 in FIG. 4).

  The lower reinforcing plate 15D is fixed to the turning frame 14 by a fixing bolt 19 (see FIG. 7). Thereby, the tank reinforcing member 15 is fixed to the turning frame 14. In addition, joining of each plate 15A-15D which comprises the above tank reinforcement member 15 can be performed, for example using welding.

  Further, an under cover 16 described later is attached below the lower reinforcing plate 15D of the revolving frame 14. By this under cover 16, the bottom 10g of the urea water tank 10 is covered.

  A 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. With the bracket 26 fixed to the tank reinforcing member 15, the bracket 26 is restricted from moving upward in the urea water tank 10.

  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 when the movement is restricted.

  Therefore, the tank reinforcing member 15 and the urea water tank 10 are held in a state of being accommodated in the tank reinforcing member 15 by the tank bracket 26 even if they are not coupled to each other by bolts or the like. A buffer material may be provided at a predetermined position between the urea water tank 10 and the tank reinforcing member 15.

  In the state where the tank bracket 26 is disposed as described above, the bowl-shaped tank reinforcing member 15 holds the lower part from the center of the urea water tank 10, and the tank bracket 26 is located above the center of the urea water tank 10. Hold the part. As a result, the urea water tank 10 can be securely held and reinforced by the tank reinforcing member 15 and the tank bracket 26, and damage to the urea water tank 10 and interference with peripheral components can be prevented.

  Here, attention is paid to the arrangement position of the urea water tank 10 on the upper swing body 2.

  As described above, the urea water tank 10 is disposed on the outer side of the support bracket 17L in view of the necessity of performing the liquid supply process and the relationship with the space in the upper swing body 2. FIG. 8 is a plan view of the construction machine. FIG. 8A shows a state where the upper swing body 2 is not turning, and FIG. 8B shows a state where the upper swing body 2 is turned.

  As shown in FIG. 8A, when the upper swing body 2 is not swung (referred to as a non-turning state), the urea water tank 10 is disposed at a position facing the lower traveling body 1. Therefore, in the non-turning state, there is a low possibility that the drain plug 11 of the urea water tank 10 such as a rock (hereinafter referred to as an external contact object) contacts from the lower part of the turning frame 14.

  On the other hand, as shown in FIG. 8B, when the upper swing body 2 is displaced with respect to the lower traveling body 1 by turning, the urea water tank 10 faces the ground via the under cover 16. (Hereinafter referred to as a turning state). Therefore, in the turning state, an external contact object may come into contact with the under cover 16 from the lower part of the turning frame 14.

  6A and 6B are views of the arrangement position of the urea water tank 10 of the swivel frame 14 as viewed from below. FIG. 6A shows a state in which the under cover 16 is removed from the turning frame 14. In a state where the under cover 16 is removed, the drain plug 11 is exposed at the lower portion of the turning frame 14.

  FIG. 6B shows a state in which the under cover 16 is attached to the turning frame 14. The under cover 16 is a plate-like member made of metal or other material (for example, resin). The under cover 16 is fixed to the revolving frame 14 using screws 29 (see FIG. 7).

  In this way, by providing the under cover 16 at a position facing the drain plug 11, it is possible to prevent the external contact object from directly contacting the drain plug 11. Thereby, it can prevent to some extent that an external contact thing contacts the drain plug 11, and the urea water tank 10 resulting from this damages.

  However, the construction machine is used in a harsh environment, and a high-speed or large-size external abutting object pushes up and deforms the undercover 16, so that the undercover 16 eventually becomes the drain plug 11. It is conceivable that the urea water tank 10 is damaged due to this contact.

  Since the under cover 16 is disposed on the revolving frame 14, its thickness (strength) is limited. For this reason, it is difficult to completely suppress the deformation of the under cover 16 due to all external abutting objects coming into contact with the drain plug 11 from the lower surface of the turning frame 14.

  For this reason, when the external abutment comes into contact with the under cover 16 and a large load F is applied to the under cover 16, the under cover 16 is deformed toward the drain plug 11 as shown by a one-dot chain line in FIG. 7. End up.

  Therefore, in the configuration in which the drain plug 11 only protrudes from the lower surface of the tank mounting plate 15C, it is assumed that the deformed under cover 16 contacts the drain plug 11 and the urea water tank 10 is damaged.

  Therefore, in the present embodiment, the protective member 20 that protects the drain plug 11 is provided at the position where the plug opening 15E of the tank mounting plate 15C is formed.

  The protruding amount of the protective member 20 from the tank mounting plate 15C is set larger than the protruding amount of the drain plug 11 from the tank mounting plate 15C. Therefore, the drain plug 11 is housed inside the protective member 20.

  Therefore, in this embodiment, when the external abutment comes into contact and the under cover 16 is deformed, the under cover 16 comes into contact with the protection member 20 instead of the drain plug 11 as shown by a one-dot chain line in FIG. .

  In this embodiment, the protection member 20 is made of metal. The protection member 20 is fixed to the tank mounting plate 15C by welding, for example. However, the protection member 20 may be configured to be screwed to the tank placement plate 15C, and the protection member 20 may be configured to be detachable from the tank placement plate 15C.

  The material of the protection member 20 is not specified as long as the material can realize a predetermined strength described later. For example, a high-strength resin can be used as the material of the protection member 20, and in this case, the protection member 20 can be fixed to the tank mounting plate 15C by adhesion.

  In this embodiment, the protection member 20 has a cylindrical shape. This is because when the shape of the protection member 20 is a cylindrical shape, the buckling strength in the axial direction (vertical direction) can be increased.

  That is, when the external abutment comes into contact with the under cover 16 and the under cover 16 is deformed and comes into contact with the protective member 20, the protective member 20 is mainly moved upward (indicated by an arrow F in FIG. 7). Force is applied in the direction of force). This force F acts in a direction that causes the protective member 20 to buckle.

  On the other hand, the cylindrical shape is a shape resistant to buckling. Therefore, by making the shape of the protection member 20 cylindrical, the deformation of the protection member 20 is prevented and the drain plug 11 can be reliably protected.

  However, the shape of the protection member 20 is not limited to a cylindrical shape, and may be a cylindrical shape having a cross section of a triangle, a quadrangle, or the like as long as deformation can be prevented when the external abutment comes into contact. The protection member 20 may be formed of a plurality of columnar members, and a plurality of the protection members 20 may be erected so as to surround the drain plug 11.

  Further, the protective member 20 may be configured by combining a plurality of beams. Furthermore, the protection member 20 can be a bottomed cylinder. That is, the protection member 20 according to the present embodiment includes all aspects for protecting the drain plug 11.

  By providing the protection member 20 having the above-described configuration, the deformed under cover 16 contacts the protection member 20 instead of the drain plug 11 even when the external contact object contacts and the under cover 16 is deformed. At this time, since the protection member 20 is provided on the tank mounting plate 15 </ b> C constituting the tank reinforcement member 15, this contact force is not applied to the drain plug 11.

  Therefore, even if the urea water tank 10 is made of resin and has a relatively low strength, the protection member 20 is provided to reliably prevent the urea water tank 10 from being damaged when the external abutting object comes into contact therewith. be able to.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the under cover 16 is provided. However, when the protection member 20 can protect the external contact member from coming into contact with the drain plug 11, the under cover 16 is not necessarily required. .

  Moreover, in the said embodiment, the structure which provided the protection member 20 so that the drain plug 11 might be enclosed was shown. However, when the under cover 16 is deformed by an external abutment, it is not always necessary to surround the drain plug 11 as long as the deformed under cover 16 can be prevented from contacting the drain plug 11.

  In the above-described embodiment, the configuration in which the protection member 20 is disposed on the tank mounting plate 15C (tank reinforcement member 15) is shown. However, the arrangement position of the protection member 20 is not limited to the tank mounting plate 15C, and can be provided on the revolving frame 14, the under cover 16, and the like.

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 10b Inclined surface 10c Recess 10d Liquid supply port 10e Upper mounting portion 10f Lower mounting portion 10g Bottom 11 Drain plug 13 Heat exchanger unit 14 Swivel frame 15 Tank reinforcing member 15A Side reinforcing plate 15B Upper reinforcing plate 15C Tank mounting plate 15D Lower reinforcing plate 15E Plug opening 16 Under cover 17L, 17R Support bracket 18 Boom foot pin 20 Protection member 26 Tank bracket 30 Filler 31 Filler bracket

Claims (3)

A lower traveling body,
An upper swing body that is rotatably mounted on the lower traveling body;
A resin-made liquid reducing agent tank in which a liquid reducing agent is stored and a drain plug is provided at the bottom;
A construction machine having a mounting member on which the liquid reducing agent tank is mounted and an opening through which a drain plug is inserted;
Before placing member, said a protective member for protecting the drain plug and and constitutes a part of the tank reinforcing member for protecting by accommodating the tank the liquid reducing agent,
The tank reinforcing member is fixed to a swing frame of the upper swing body;
The bottom of the liquid reducing agent tank is covered by an under cover provided on the swivel frame of the upper swivel body;
The construction machine according to claim 1, wherein the under cover is disposed below the protective member that protects the drain plug.   The construction machine according to claim 1, wherein the protection member has a cylindrical shape.   The construction machine according to claim 1 or 2, wherein a protruding amount of the protective member from the mounting member is larger than a protruding amount of the drain plug from the mounting member.

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