JP6411973B2 - Small excavator - Google Patents

Description

  The present invention relates to a small hydraulic excavator that is suitably used for excavation work or the like in a narrow work site, and more particularly to a small hydraulic excavator that includes an exhaust pipe extending upward.

  In general, a hydraulic excavator, which is a typical example of a construction machine, is provided with a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and an upside-down movable structure on the front side of the upper revolving body. And a working device.

  On the other hand, a small hydraulic excavator called a mini excavator is suitably used for excavation work in a narrow work site such as an urban area. The small excavator is designed so that the upper swinging body (width between the left and right crawlers) is smaller than the upper swinging body (width between the left and right crawlers) so that the upper swinging body can smoothly turn even in a narrow work site. The rear end of the revolving frame) is configured to be able to swivel within a specified range, and the upper revolving body is formed as small as possible.

  In addition, a small hydraulic excavator called an ultra-small swing machine is constructed such that when the upper swing body is swung while the boom of the work apparatus is raised upward and the arm is folded to the boom side, Are within the width (vehicle width) in the left and right directions of the lower traveling body. For this reason, in a small hydraulic excavator, a canopy that covers the driver's seat from above is often used in order to make the upper swing body as small as possible.

  Here, as a small hydraulic excavator used for excavation work in an urban area, the exhaust pipe is directed upward in order to prevent exhaust gas discharged when the engine is operated, for example, toward the outer wall of a house or a plant. And a configuration in which exhaust gas is discharged at a high position from the ground is disclosed (see Patent Document 1).

  The exhaust pipe extends from the upper side to the vicinity of the upper end of the canopy that covers the driver's seat, and the upper end of the exhaust pipe is an exhaust port for exhaust gas. Therefore, the exhaust gas exhausted from the tail pipe connected to the exhaust muffler of the engine is led to the vicinity of the upper end of the canopy by the exhaust pipe, and is higher than the head of the operator seated on the outer wall of the house, planting, or driver's seat At the position, it is discharged to the outside through the exhaust port.

JP 2007-62506 A

  Here, in a conventional hydraulic excavator, a floor member covering the upper side of the engine is provided so as to be tiltable with respect to the turning frame, and a driver's seat and a canopy are attached to the floor member. The exhaust pipe used in this excavator is fixed to the swing frame and fixed to the floor member, and is movable to the swing frame together with the floor member. It can be divided into two parts by the side exhaust pipe. For this reason, compared with the case where one exhaust pipe is used, the length of the fixed side exhaust pipe and the movable side exhaust pipe is set to be short, and the fixed side exhaust pipe and the movable side exhaust pipe have sufficient mounting strength. Is attached to the car body.

  On the other hand, when one exhaust pipe extending in the upward and downward directions is used, the length dimension in the upward and downward directions is increased. For this reason, it is necessary to increase the attachment strength of the exhaust pipe, for example, by increasing the number of attachment points of the exhaust pipe to the vehicle body.

  However, in a small hydraulic excavator, the upper swing body is formed as small as possible, so it is difficult to secure a space for increasing the number of exhaust pipe attachment points, and ensuring the exhaust pipe attachment strength. There is a problem that is difficult.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a small hydraulic excavator capable of increasing the mounting strength of an exhaust pipe extending upward and downward.

  In order to solve the above-described problems, the present invention is a self-propelled lower traveling body and a rear end mounted on the lower traveling body and capable of turning within a range defined with respect to the vehicle width of the lower traveling body. An upper revolving body and a working device provided on the front side of the upper revolving body, the upper revolving body comprising a revolving frame forming a support structure, and a counterweight provided at a rear end of the revolving frame. An engine mounted on the swivel frame located on the front side of the counterweight, a driver seat pedestal that covers the upper side of the engine and is provided on the swivel frame and to which a driver's seat is attached, and on the front side of the driver seat pedestal A footrest member that serves as a footrest portion for an operator seated on the driver's seat, a canopy provided to cover an upper side of the driver's seat, and the counterway located on the rear side of the canopy Is applied to a small hydraulic excavator comprising an exhaust pipe arranged to extend upwardly for discharging exhaust gas from the engine from.

A feature of the present invention is that the counterweight is provided in the counterweight and penetrates between the inner surface and the outer surface of the counterweight, and is provided on the outer surface side of the counterweight. A cover member, a base plate attached to the cover member, having a pipe insertion hole communicating with the opening and having a lower end of the exhaust pipe fixed to the pipe insertion hole, and provided on a lower side of the exhaust pipe; The reinforcing member includes a reinforcing member that extends in the upward and downward directions and is fixed to the outer peripheral surface of the exhaust pipe and the upper surface of the base plate. The reinforcing member has a mountain shape in the middle in the width direction orthogonal to the upward and downward directions. to be formed by bent L-shaped cross section of the reinforcing plate is to both edges of the width direction of the reinforcing plate was secured to Ru configured on the outer circumferential surface of the exhaust pipe.

  According to the present invention, by attaching the base plate to the cover member with the lower end of the exhaust pipe attached to the pipe insertion hole of the base plate, the exhaust gas discharged from the engine is passed through the counterweight through hole to the exhaust pipe. And can be discharged from the upper end of the exhaust pipe. In this case, since the reinforcing member is fixed to the outer peripheral surface of the lower side of the exhaust pipe and the upper surface of the base plate, the attachment site between the exhaust pipe and the base plate can be reinforced by the reinforcing member. Strength can be increased.

It is the side view which looked at the small hydraulic excavator by embodiment of this invention from the left side. It is the top view which looked at the small hydraulic excavator from the upper part. It is the rear view which looked at the small hydraulic excavator from back. It is a partially broken side view showing the upper swing body of the small hydraulic excavator. FIG. 5 is a cross-sectional view showing a counterweight, a cover member, a base plate, an exhaust pipe, a tail pipe, an intermediate pipe and the like in FIG. 4. It is the principal part enlarged view which looked at the cover member in FIG. 5, a base board, an exhaust pipe, etc. from arrow VI-VI direction. It is sectional drawing which looked at the base plate in FIG. 6, an exhaust pipe, a reinforcement board, etc. from the arrow VII-VII direction. It is a perspective view shown in the state where a cover member, a base board, an exhaust pipe, and a reinforcing board were assembled. It is a disassembled perspective view which shows a base plate and an exhaust pipe. It is a disassembled perspective view which shows the exhaust pipe and the reinforcement board which were fixed to the base board. It is a perspective view which shows the state which fixed the reinforcement board to the outer peripheral surface and base plate of an exhaust pipe. It is a disassembled perspective view which shows the state which attaches the base plate which fixed the exhaust pipe and each reinforcement board to a cover member.

  Hereinafter, a small hydraulic excavator according to an embodiment of the present invention will be described in detail with reference to FIGS.

  1 to 3, a small hydraulic excavator 1 is suitably used for excavation work in a narrow work site such as the inside of a building or an urban area. The small excavator 1 includes a self-propelled crawler-type lower traveling body 2 and an upper revolving body 3 that is turnably mounted on the lower traveling body 2. A working device 4 of the type is provided.

  The offset boom type working device 4 includes a lower boom 4A, an upper boom 4B, an arm stay 4C, an arm 4D, a bucket 4E as a work tool, a link rod 4F, a boom cylinder 4G, an offset cylinder 4H, an arm cylinder 4I, and the like. It is constituted by a bucket cylinder 4J and the like. The offset boom type working device 4 swings the upper swing body 3 relative to the lower travel body 2 by expanding and contracting the offset cylinder 4H and swinging the upper boom 4B leftward and rightward relative to the lower boom 4A. Even in this case, the arm 4D can be translated (offset) in the left and right directions via the arm stay 4C, so that the arm 4D is preferably used for excavation work such as side digging.

  On the other hand, the upper swing body 3 includes a swing frame 5, a counterweight 6, an engine 7, a floor member 11, a driver seat base 12, a footrest plate 13, a driver seat 14, an exterior cover 16, a canopy 17 and the like which will be described later. Has been. In this case, as shown in FIG. 2, the rear end of the upper swing body 3 is set by a rear surface 6A of a counterweight 6 described later, and the rear surface 6A of the counterweight 6 is connected to the left and right crawler tracks of the lower traveling body 2. It can turn with respect to the lower traveling body 2 within a range defined with respect to a width dimension A (vehicle width of the lower traveling body) between 2A.

  The small excavator 1 according to the present embodiment is configured as an ultra-small turning machine, the upper turning body 3 has a width dimension substantially equal to the vehicle width A of the lower traveling body 2, and the rear surface 6A of the counterweight 6 is It is configured so as to be substantially within a virtual circle having a turning radius R centered on the turning center O. Further, the small excavator 1 raises the lower boom 4A of the work device 4 upward, and when the upper swing body 3 is swung while the arm 4D is folded to the upper boom 4B side, The body 3 is configured to fit within the vehicle width A of the lower traveling body 2.

  The turning frame 5 is a base of the upper turning body 3. The revolving frame 5 includes a flat bottom plate 5A and left and right vertical plates 5B (only the left side is shown) standing on the bottom plate 5A with an interval in the left and right directions and extending in the front and rear directions. And formed as a strong support structure. A foot part of a lower boom 4A constituting the work device 4 is rotatably attached to the left and right vertical plates 5B.

  The counterweight 6 is attached to the rear end of the revolving frame 5 and balances the weight with the work device 4. The counterweight 6 is integrally formed by casting or the like, for example, and rises upward from the turning frame 5 so as to cover an engine 7 described later from behind. Here, the turning radius R of the upper turning body 3 is defined by the distance from the turning center O of the upper turning body 3 to the rear surface 6A of the counterweight 6. For this reason, the rear surface 6 </ b> A of the counterweight 6 is formed in an arc shape along a circle having a turning radius R around the turning center O of the upper turning body 3.

  On the other hand, as shown in FIGS. 3 to 5, at the upper left corner of the counterweight 6, there are a rear surface 6A that is the outer surface of the counterweight 6 and an inner surface 6B of the counterweight 6 that is located on the engine 7 side described later. A through hole 6 </ b> C penetrating forward and rearward is formed. An intermediate pipe 30 to be described later is disposed in the through hole 6C.

  The engine 7 is mounted on the revolving frame 5 in front of the counterweight 6. The engine 7 is disposed on the turning frame 5 in a horizontally placed state in which a crankshaft (not shown) extends leftward and rightward. A hydraulic pump 8 is provided on the left side of the engine 7, and the hydraulic pump 8 is driven by the engine 7 so that pressure is applied toward various hydraulic actuators including the cylinders 4G, 4H, 4I, and 4J of the work device 4. Supply oil.

  An exhaust muffler 9 is provided on the exhaust side of the engine 7. The exhaust muffler 9 is formed as a cylindrical body whose both ends in the length direction (front and rear directions) are closed, and a plurality of sound deadening walls are provided therein. The exhaust muffler 9 is for reducing the exhaust sound of the exhaust gas discharged from the engine 7 by a silencing wall. A tail pipe 10 bent in a J-shape is connected to the rear end side (downstream side in the exhaust gas flow direction) of the exhaust muffler 9, and the tip 10 A of the tail pipe 10 faces the through hole 6 C of the counterweight 6. It extends.

  The floor member 11 is disposed on the upper side of the engine 7 so as to be tiltable with respect to the turning frame 5. The floor member 11 is integrally formed including a driver seat base 12 and a footrest plate 13 which will be described later. A floor support portion 11A is provided between the front end of the floor member 11 and the revolving frame 5, and the floor member 11 is supported to be tiltable upward and downward (obliquely upward) with the floor support portion 11A as a fulcrum. Yes.

  The driver seat base 12 is provided on the turning frame 5 so as to cover the upper side of the engine 7. The driver seat base 12 includes a seat base 12A to which a driver seat 14 described later is attached, and a canopy mounting plate 12B projecting rearward from the seat base 12A. A right rear pillar 17D and a left rear pillar 17E of a canopy 17, which will be described later, are fixed to the canopy mounting plate 12B of the driver seat base 12.

  A footrest plate 13 as a footrest member is disposed on the front side of the driver seat base 12. The footrest plate 13 forms a footrest portion for an operator seated on the driver's seat 14. The footrest plate 13 constitutes the floor member 11 together with the driver seat base 12, and the footrest plate 13 and the driver seat base 12 are configured to be tiltable upward and downward with the floor support portion 11A as a fulcrum. Has been. Further, the left side of the footrest plate 13 is an operator entrance to the driver's seat 14.

  The driver's seat 14 is attached on the seat base 12 </ b> A of the driver's seat base 12 constituting the floor member 11. The driver's seat 14 is seated when an operator who gets on the floor member 11 operates the small hydraulic excavator 1. For this reason, on the left and right sides of the driver's seat 14, work operation lever devices 15 (only the left side are shown) for operating the work device 4 and the like are disposed.

  The exterior cover 16 is disposed on the revolving frame 5 so as to surround the engine 7 and the like. The exterior cover 16 includes a left side cover 16A that curves and extends forward from the left end side of the counterweight 6 and a right side cover 16B that curves and extends forward from the right end side of the counterweight 6. Yes. An engine 7, a hydraulic pump 8, and the like are accommodated in a space (machine room) surrounded by the exterior cover 16, the counterweight 6, and the floor member 11.

  The canopy 17 is provided so as to cover the upper side of the driver's seat 14. The canopy 17 is arranged on the left side of the work device 4 (lower boom 4A) and is configured to cover the right side and the upper side of the driver's seat 14. The canopy 17 is a so-called three-column type provided with a right side surface portion 17A covering the right side of the driver seat 14, an upper surface portion 17B covering the upper side of the driver seat 14, a right front pillar 17C, a right rear pillar 17D, and a left rear pillar 17E. It is configured as a canopy.

  Here, of the three pillars 17 </ b> C to 17 </ b> E constituting the canopy 17, the lower end of the right front pillar 17 </ b> C is attached to the right front portion of the footrest plate 13. The lower ends of the right rear pillar 17D and the left rear pillar 17E are attached to the canopy mounting plate 12B of the driver seat base 12. The canopy 17 is not limited to a three-column canopy, and may be a two-column or four-column canopy.

  Next, the cover member 18, the base plate 20, the exhaust pipe 22 and the like used in the present embodiment will be described with reference to FIGS. 5 to 12.

  The cover member 18 is attached to the rear surface 6 </ b> A side of the counterweight 6 and covers the through hole 6 </ b> C formed in the counterweight 6. As shown in FIGS. 5 and 12, the cover member 18 extends rearward from the flat front plate portion 18 </ b> A extending upward and downward along the rear surface 6 </ b> A of the counterweight 6 and the upper end of the front plate portion 18 </ b> A. A flat upper plate portion 18B and a hollow cylindrical portion 18C provided in a bent state between the front plate portion 18A and the upper plate portion 18B are configured, and are integrally formed by casting or the like, for example. .

  The front plate portion 18A of the cover member 18 is formed with a front opening 18D that allows the through hole 6C of the counterweight 6 and the cylinder portion 18C to communicate with each other. On the other hand, the upper plate portion 18B of the cover member 18 is formed with an upper opening 18E that opens to the inside of the cylindrical portion 18C. The upper plate portion 18B is formed with female screw holes 18F penetrating upward and downward at a plurality of locations (for example, four locations) surrounding the upper opening 18E.

  The cover member 18 is integrally fixed to the rear surface 6A of the counterweight 6 with the through holes 6C covered by screwing a plurality of bolts 19 inserted through the front plate portion 18A to the counterweight 6. ing. In this state, the upper plate portion 18B of the cover member 18 is disposed on substantially the same plane as the upper surface of the counterweight 6, and a base plate 20 described later is attached to the upper plate portion 18B.

  The base plate 20 is attached to the upper plate portion 18B of the cover member 18 in a state where an exhaust pipe 22 described later is attached. The base plate 20 is formed of a quadrangular (trapezoidal) plate body having substantially the same shape as the upper plate portion 18B of the cover member 18. A pipe insertion hole 20 </ b> A is formed in the center of the base plate 20 so as to be substantially concentric with the upper opening 18 </ b> E of the cover member 18. The pipe insertion hole 20A is for inserting a lower end 22B of an exhaust pipe 22 to be described later.

  Two screw seats 20C having a rectangular shape are provided at two positions on the upper surface 20B of the base plate 20 across the pipe insertion hole 20A. The screw seats 20C are respectively provided in the female screw holes 18F of the cover member 18. Two bolt insertion holes 20D penetrating upward and downward at corresponding positions are formed. Then, as shown in FIG. 12, the base plate 20 is inserted into the bolt insertion hole 20D of each screw seat 20C, and the bolt 21 is screwed into the female screw hole 18F of the cover member 18, thereby covering the cover member. 18 is detachably attached to the upper plate portion 18B.

  On the other hand, in the vicinity of the pipe insertion hole 20A in the base plate 20, four drain holes 20E penetrating the base plate 20 upward and downward are formed (see FIG. 9). These drain holes 20E are arranged at a constant angular interval (for example, 90 degrees) in the circumferential direction of the pipe insertion hole 20A. Then, as shown in FIG. 7, when four reinforcing plates 24 described later are fixed to the outer peripheral surface 22C of the exhaust pipe 22 inserted through the pipe insertion hole 20A at an angular interval of 90 degrees, each drain hole 20E. Is arranged between the outer peripheral surface 22C of the exhaust pipe 22 and each reinforcing plate 24 in plan view.

  The exhaust pipe 22 discharges exhaust gas from the engine 7 and is located on the rear side of the canopy 17 and extends upward from the counterweight 6. The exhaust pipe 22 is formed by a cylindrical body (chimney) extending linearly in the upward and downward directions, and the upper end portion of the exhaust pipe 22 is an exhaust port 22A for exhausting exhaust gas backward. In this case, unlike the cab surrounding the periphery of the driver's seat 14, the canopy 17 covers the driver's seat 14 from above, so that the exhaust gas is discharged at a position higher than the head of the operator seated in the driver's seat 14. It is necessary to discharge. For this reason, the exhaust port 22 </ b> A of the exhaust pipe 22 opens rearward in the vicinity of the upper end of the left rear pillar 17 </ b> E constituting the canopy 17.

  On the other hand, as shown in FIGS. 9 and 10, the lower end 22 </ b> B of the exhaust pipe 22 is inserted into the pipe insertion hole 20 </ b> A of the base plate 20 in a fitted state, and the outer peripheral surface 22 </ b> C of the exhaust pipe 22 is It is welded over the entire circumference with respect to the upper surface 20B. Thus, a weld bead 23 is formed over the entire circumference between the outer peripheral surface 22C of the exhaust pipe 22 and the upper surface 20B of the base plate 20.

  Then, as shown in FIG. 12, the base plate 20 to which the lower end 22 </ b> B of the exhaust pipe 22 is fixed is attached to the upper plate portion 18 </ b> B of the cover member 18 attached to the rear surface 6 </ b> A of the counterweight 6 using bolts 21. Accordingly, as shown in FIGS. 1 to 4, the exhaust pipe 22 is arranged in an upright state from the rear surface 6 </ b> A of the counterweight 6, and the exhaust port 22 </ b> A of the exhaust pipe 22 has a left rear that constitutes the canopy 17. It is configured to open rearward from the pillar 17E and in the vicinity of the upper end of the left rear pillar 17E.

  A plurality of (for example, four) reinforcing plates 24 as reinforcing members are provided on the lower side of the exhaust pipe 22 attached to the base plate 20 so as to surround the periphery of the exhaust pipe 22. Each of these reinforcing plates 24 has the same shape, extends upward and downward along the exhaust pipe 22, and is fixed to the outer peripheral surface 22 </ b> C of the exhaust pipe 22 and the upper surface 20 </ b> B of the base plate 20. The attachment strength of the exhaust pipe 22 with respect to the is increased.

  As shown in FIG. 10, each reinforcing plate 24 is formed of a plate having an L-shaped cross section in which an intermediate portion in the width direction perpendicular to the upper and lower directions (length direction) is bent into a mountain shape (substantially right angle). ing. Two edge portions (both edge portions) 24A in the width direction of each reinforcing plate 24 are welded to the outer peripheral surface 22C of the exhaust pipe 22, and the end edge portion 24A of the reinforcing plate 24 and the outer peripheral surface 22C of the exhaust pipe 22 are connected. A weld bead 25 extending upward and downward is formed therebetween.

  On the other hand, the lower end 24B of each reinforcing plate 24 is welded to the upper surface 20B of the base plate 20, and a weld bead bent in an L shape is formed between the lower end 24B of the reinforcing plate 24 and the upper surface 20B of the base plate 20. 26 is formed. In this case, since each reinforcing plate 24 has a bent shape with an L-shaped cross section, the reinforcing plates for the exhaust pipe 22 are brought into contact with each other by bringing the two edge portions 24A into contact with the outer peripheral surface 22C of the exhaust pipe 22. 24 is easily configured to be aligned.

  On the lower end side of each reinforcing plate 24, an inclined portion 24 </ b> C that is inclined obliquely upward from the lower end portion 24 </ b> B is provided at the corner where the edge 24 </ b> A in the width direction of the reinforcing plate 24 intersects the lower end portion 24 </ b> B. The inclined portion 24 </ b> C allows the weld bead 23 formed between the upper surface 20 </ b> B of the base plate 20 and the outer peripheral surface 22 </ b> C of the exhaust pipe 22 to escape. That is, as shown in FIG. 6, by providing an inclined portion 24 </ b> C on the lower end side of each reinforcing plate 24, when the lower end portion 24 </ b> B of each reinforcing plate 24 is welded to the upper surface 20 </ b> B of the base plate 20, The lower end 24B is configured to avoid interference with the weld bead 23 formed between the upper surface 20B of the base plate 20 and the outer peripheral surface 22C of the exhaust pipe 22.

  As shown in FIG. 7, the four reinforcing plates 24 are arranged at equal intervals (90 degrees) in the circumferential direction while covering the outer peripheral surface 22 </ b> C of the exhaust pipe 22. These two edge portions 24A are fixed to the outer peripheral surface 22C of the exhaust pipe 22 by welding. Thereby, each reinforcement board 24 becomes a structure which reinforces the exhaust pipe 22 equally in four places of the circumferential direction. In addition, since each reinforcing plate 24 is arranged in a square frame shape with one side having a length substantially equal to the outer diameter of the exhaust pipe 22, the mounting space for each reinforcing plate 24 can be kept as small as possible. It can be configured.

  On the other hand, as shown in FIG. 7, by welding each reinforcing plate 24 to the outer peripheral surface 22C of the exhaust pipe 22 and the upper surface 20B of the base plate 20, between each reinforcing plate 24 and the exhaust pipe 22, A closed cross-sectional space 27 having a substantially triangular shape is formed. For this reason, each reinforcing plate 24 is disposed at a position corresponding to four drain holes 20 </ b> E provided in the base plate 20. Thereby, even if rainwater or the like enters the closed cross-sectional space 27, the rainwater or the like can be discharged downward (inside the cover member 18) through the drain hole 20E.

  The intermediate pipe support plate 28 is attached to a portion of the inner surface 6B of the counterweight 6 in the vicinity of the through hole 6C using a bolt 29, and supports an intermediate pipe 30 described later. A tail pipe insertion hole 28A having a slightly smaller diameter than an inlet 30C of a conical pipe portion 30A, which will be described later, is formed at the center portion of the intermediate pipe support plate 28, and the tail pipe is inserted into the conical pipe portion 30A through the tail pipe insertion hole 28A. The tip 10A of the pipe 10 is inserted.

  The intermediate pipe 30 is attached to the counterweight 6 via the intermediate pipe support plate 28, and extends into the cover member 18 through the through hole 6 </ b> C of the counterweight 6. As shown in FIG. 5, the intermediate pipe 30 includes a tip 10 </ b> A of the tail pipe 10 connected to the exhaust muffler 9 of the engine 7, and a lower end 22 </ b> B of the exhaust pipe 22 attached to the cover member 18 via the base plate 20. The exhaust gas discharged from the tail pipe 10 is led to the exhaust pipe 22.

  Here, the intermediate pipe 30 includes a conical pipe portion 30A having a truncated cone shape (cup shape) disposed on the tail pipe 10 side, and a bent pipe portion having a J-shaped bent shape disposed on the exhaust pipe 22 side. 30B. The conical pipe portion 30A has a large diameter inlet 30C into which the tip 10A of the tail pipe 10 is inserted on the inner peripheral side, and a small diameter connection port 30D to which the bent pipe portion 30B is connected. The opening area gradually decreases toward the connection port 30D. The conical pipe portion 30A of the intermediate pipe 30 is fixed to the central portion of the intermediate pipe support plate 28 using means such as welding, and the inlet 30C of the conical pipe portion 30A is inserted into the tail pipe of the intermediate pipe support plate 28. It is arranged concentrically with the hole 28A.

  On the other hand, the bent pipe portion 30B is formed by bending a pipe body having a uniform outer diameter over the entire length into a J shape. One end side (lower end side) in the length direction of the bent pipe portion 30B is connected to the connection port 30D of the conical pipe portion 30A, and the other end side (upper end side) in the length direction is an exhaust gas outlet 30E. ing. Accordingly, the outlet 30E of the bent pipe portion 30B has an opening area substantially equal to the connection port 30D of the conical pipe portion 30A, and is inserted into the inner peripheral side of the exhaust pipe 22.

  Thus, the tip 10A of the tail pipe 10 and the lower end 22B of the exhaust pipe 22 are connected via the intermediate pipe 30, and the exhaust gas discharged from the tail pipe 10 passes through the intermediate pipe 30 to the exhaust pipe 22. It is guided. At this time, since the opening area of the intermediate pipe 30 gradually decreases from the conical pipe portion 30A toward the bent pipe portion 30B, the exhaust gas discharged from the tail pipe 10 flows from the conical pipe portion 30A to the bent pipe portion 30B. As the flow rate increases, the flow rate increases and the pressure in the bent pipe portion 30B decreases. As a result, the intermediate pipe 30 functions as an ejector that sucks the exhaust gas discharged from the tail pipe 10, and can reliably send a large amount of exhaust gas to the exhaust pipe 22.

  The small hydraulic excavator 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  First, the operator sits in the driver's seat 14, activates the engine 7, and drives the hydraulic pump 8 and the like. In this state, when the operator operates the left and right operation lever devices 15, excavation work such as side digging can be performed using the work device 4.

  In this case, the small excavator 1 works with the upper swing body 3 when the upper swing body 3 is swung while the lower boom 4A of the work device 4 is raised upward and the arm 4D is folded to the lower boom 4A side. The device 4 is configured as an ultra-small turning machine that can be accommodated within the vehicle width A of the lower traveling body 2. Thereby, the small hydraulic excavator 1 can perform a smooth turning operation even in a narrow work site such as an urban area, and can perform excavation work efficiently.

  On the other hand, when performing maintenance work on the hydraulic system including the engine 7 and the hydraulic pump 8, the floor member 11 is tilted upward along with the driver's seat 14 and the canopy 17 with the floor support portion 11A as a fulcrum. As a result, the engine 7, the hydraulic pump 8 and the like housed in the machine room can be exposed to the outside, and maintenance work is performed on the hydraulic system including the engine 7 and the hydraulic pump 8 with a large work space secured. Can do.

  Here, when the small hydraulic excavator 1 is in operation, the exhaust gas from the engine 7 flows to the tail pipe 10 through the exhaust muffler 9. The exhaust gas is guided from the tip 10 </ b> A of the tail pipe 10 to the exhaust pipe 22 through the intermediate pipe 30, and is discharged to the outside through the exhaust port 22 </ b> A formed at the upper end of the exhaust pipe 22.

  In this case, the exhaust port 22A of the exhaust pipe 22 opens rearwardly from the left rear pillar 17E of the canopy 17 and in the vicinity of the upper end of the left rear pillar 17E. For this reason, even when the small hydraulic excavator 1 performs excavation work in an urban area or the like, exhaust gas can be discharged at a high position sufficiently away from the ground, and the outer wall and planting of a house existing around the small hydraulic excavator 1 Can be protected from exhaust gas.

  Further, unlike the cab surrounding the driver's seat 14, even when the canopy 17 that covers the driver's seat 14 from above is used, the exhaust gas is discharged from the exhaust port 22A disposed near the upper end of the left rear pillar 17E. As a result, the exhaust gas does not stay near the head of the operator seated in the driver's seat 14, and a good working environment for the operator can be ensured.

  Next, in the small excavator 1 according to the present embodiment, an operation of attaching the exhaust pipe 22 to the cover member 18 attached to the rear surface 6A of the counterweight 6 via the base plate 20 or the like will be described.

  First, as shown in FIG. 9, the lower end 22B of the exhaust pipe 22 is inserted into the pipe insertion hole 20A of the base plate 20 in a fitted state. Then, the outer peripheral surface 22C of the exhaust pipe 22 is welded to the upper surface 20B of the base plate 20 over the entire periphery. As a result, as shown in FIG. 10, a weld bead 23 is formed over the entire circumference between the outer peripheral surface 22 </ b> C of the exhaust pipe 22 and the upper surface 20 </ b> B of the base plate 20, and the exhaust pipe 22 is formed on the base plate 20. On the other hand, it is fixed in a state extending in the vertical direction.

  Next, four reinforcing plates 24 are arranged so as to surround the lower end side of the exhaust pipe 22, and the edge 24A in the width direction of each reinforcing plate 24 is welded to the outer peripheral surface 22C of the exhaust pipe 22, and each The lower end 24B of the reinforcing plate 24 is welded to the upper surface 20B of the base plate 20. Accordingly, as shown in FIG. 11, a weld bead 25 is formed between the edge 24 </ b> A of each reinforcing plate 24 and the outer peripheral surface 22 </ b> C of the exhaust pipe 22, and the lower end 24 </ b> B of each reinforcing plate 24 and the base plate A weld bead 26 is formed between the upper surface 20 </ b> B of 20. As a result, the four reinforcing plates 24 are firmly joined to the exhaust pipe 22 and the base plate 20, respectively, and each reinforcing plate 24 can increase the attachment strength between the base plate 20 and the exhaust pipe 22. .

  In this case, since the inclined portion 24C is provided at the corner where the edge 24A and the lower end 24B of each reinforcing plate 24 intersect, the lower end 24B of each reinforcing plate 24 is used as the upper surface 20B of the base plate 20. The lower end portion 24B of each reinforcing plate 24 interferes with the weld bead 23 formed between the upper surface 20B of the base plate 20 and the outer peripheral surface 22C of the exhaust pipe 22 when being welded to each other by the inclined portion 24C. Can be avoided. As a result, each reinforcing plate 24 can be firmly joined to the exhaust pipe 22 and the base plate 20, and the exhaust pipe 22 fixed to the base plate 20 can be reinforced by each reinforcing plate 24.

  At this time, four closed cross-sectional spaces 27 having a substantially triangular shape are formed between the reinforcing plates 24 and the exhaust pipe 22 (see FIG. 7). For this reason, even if rainwater or the like enters the closed cross-sectional space 27 by arranging each reinforcing plate 24 at a position corresponding to the four drain holes 20E provided in the base plate 20, the rainwater or the like Can be discharged downward through the drain hole 20E.

  After the lower end 22B of the exhaust pipe 22 is welded to the base plate 20 and the reinforcing plates 24 are welded to the upper surface 20B of the base plate 20 and the outer peripheral surface 22C of the exhaust pipe 22, as shown in FIG. The bolts 21 are inserted into the bolt insertion holes 20D, and the bolts 21 are screwed into the female screw holes 18F provided in the upper plate portion 18B of the cover member 18. Accordingly, as shown in FIG. 8, the exhaust pipe 22 stands upright above the cover member 18 attached to the rear surface 6 </ b> A of the counterweight 6 in a state where the exhaust pipe 22 is reinforced by the reinforcing plates 24.

  Thus, as shown in FIGS. 1 to 4, the exhaust pipe 22 is arranged in an upright state from the rear surface 6 </ b> A of the counterweight 6, and the exhaust port 22 </ b> A on the upper end side of the exhaust pipe 22 constitutes the canopy 17. It opens rearward behind the left rear pillar 17E and in the vicinity of the upper end of the left rear pillar 17E. On the other hand, as shown in FIGS. 4 and 5, the cover member passes through the through hole 6 </ b> C of the counterweight 6 between the lower end 22 </ b> B of the exhaust pipe 22 and the tail pipe 10 connected to the exhaust muffler 9 of the engine 7. 18 is connected via an intermediate pipe 30 extending inside.

  Thus, in the small excavator 1 according to the present embodiment, the cover member 18 that covers the through hole 6C and has the upper opening 18E is provided on the rear surface 6A of the counterweight 6, and the base plate 20 attached to the cover member 18 is provided. The lower end 22B of the exhaust pipe 22 extending upward and downward is fixed, and a plurality of lower ends of the exhaust pipe 22 are fixed to the upper surface 20B of the base plate 20 and the outer peripheral surface 22C of the exhaust pipe 22. The reinforcing plate 24 is provided. Thereby, the attachment site | part of the exhaust pipe 22 and the base board 20 can be reinforced with each reinforcement board 24, and the attachment intensity | strength of the exhaust pipe 22 with respect to the base board 20 can be raised.

  Moreover, since each reinforcing plate 24 is provided between the base plate 20 to which the exhaust pipe 22 is attached and the exhaust pipe 22, the mounting space for each reinforcing plate 24 can be made as small as possible. As a result, even in the small excavator 1 in which the upper swing body 3 is formed to be small, the mounting strength of the exhaust pipe 22 can be increased by using each reinforcing plate 24 without securing a space for increasing the number of attachment positions of the exhaust pipe 22. Can be increased.

  Further, according to the present embodiment, the counterweight 6 extends through the through hole 6C into the cover member 18 and discharges exhaust gas from the tip 10A of the tail pipe 10 and the lower end 22B of the exhaust pipe 22. It is set as the structure which provides the intermediate | middle pipe 30 which connects between. Thereby, the exhaust gas discharged from the tail pipe 10 can be guided to the lower end 22B of the exhaust pipe 22 by the intermediate pipe 30, and the exhaust gas is discharged from the exhaust port 22A provided at the upper end of the exhaust pipe 22. Can do.

  Further, according to the present embodiment, as shown in FIG. 7, the four reinforcing plates 24 are arranged at equal intervals (90 degrees) in the circumferential direction while covering the outer peripheral surface 22C of the exhaust pipe 22. The edge 24A in the width direction of each reinforcing plate 24 is fixed to the outer peripheral surface 22C of the exhaust pipe 22 by welding. Thereby, each reinforcement board 24 can reinforce the exhaust pipe 22 equally in four places of the circumferential direction, and can raise the attachment strength of the exhaust pipe 22 with respect to the base board 20. FIG. In addition, since each reinforcing plate 24 is arranged in a square frame shape with one side having a length substantially equal to the outer diameter of the exhaust pipe 22, the mounting space for each reinforcing plate 24 can be kept as small as possible. it can.

  Further, according to the present embodiment, each reinforcing plate 24 is formed as a plate body having an L-shaped cross section in which an intermediate portion in the width direction orthogonal to the upper and lower directions (length direction) is bent into a mountain shape, Two edge portions 24 </ b> A in the width direction of each reinforcing plate 24 are fixed to the outer peripheral surface 22 </ b> C of the exhaust pipe 22. Thereby, since the strength of each reinforcing plate 24 itself can be increased, the attachment strength of the exhaust pipe 22 to the base plate 20 can be further increased. Further, since each reinforcing plate 24 has a bent shape with an L-shaped cross section, the positioning of each reinforcing plate 24 with respect to the exhaust pipe 22 is achieved by bringing the two edge portions 24A into contact with the outer peripheral surface 22C of the exhaust pipe 22. Can be easily performed, and workability when each reinforcing plate 24 is welded to the exhaust pipe 22 can be improved.

  Further, according to the present embodiment, the lower end portion 24B of each reinforcing plate 24 has an inclined portion 24C that allows the weld bead 23 formed between the upper surface 20B of the base plate 20 and the outer peripheral surface 22C of the exhaust pipe 22 to escape. It is set as the structure which provides. Thereby, when the lower end portion 24B of each reinforcing plate 24 is welded to the upper surface 20B of the base plate 20, the lower end portion 24B of the reinforcing plate 24 is formed between the base plate 20 and the exhaust pipe 22. Can be avoided, and each reinforcing plate 24 can be firmly joined to the exhaust pipe 22 and the base plate 20.

  Further, according to the present embodiment, when the reinforcing plates 24 are fixed to the base plate 20 on the outer peripheral surface 22C on the lower end side of the exhaust pipe 22, the outer peripheral surface 22C of the exhaust pipe 22 and the reinforcing members are seen in plan view. A drain hole 20 </ b> E penetrating upward and downward is provided between the plate 24 and the plate 24. Accordingly, as shown in FIG. 7, even if rainwater or the like enters the four closed cross-sectional spaces 27 formed between the reinforcing plates 24 and the exhaust pipe 22, the rainwater or the like is removed from the base plate 20. It can be discharged to the outside through the drain hole 20E.

  In the embodiment, a case where four reinforcing plates 24 are fixed to the outer peripheral surface 22C of the exhaust pipe 22 and the upper surface 20B of the base plate 20 is illustrated. However, the present invention is not limited to this. For example, three or less or five or more reinforcing plates may be provided.

  Further, in the embodiment, a case where a through hole 6C that penetrates between the rear surface (outer surface) 6A and the inner surface 6B of the counterweight 6 in the front and rear directions is illustrated. However, the present invention is not limited to this. For example, a through hole that penetrates the counterweight 6 upward and downward may be provided, and an intermediate pipe may be provided in the through hole.

  Furthermore, in the embodiment, the tilt is such that the floor member 11 in which the driver's seat base 12 and the footrest plate 13 are integrally formed is supported so as to be tiltable upward and downward (obliquely upward) about the floor support portion 11A. A small hydraulic excavator 1 of the type is described as an example. However, the present invention is not limited to this. For example, the present invention can also be applied to a floor-fixed compact hydraulic excavator in which a driver seat base and a footrest member are formed as separate members and the floor member does not tilt.

DESCRIPTION OF SYMBOLS 1 Small hydraulic excavator 2 Lower traveling body 3 Upper revolving body 4 Working device 5 Revolving frame 6 Counterweight 6A Rear surface (outer surface)
6B Inner surface 6C Through hole 7 Engine 10 Tail pipe 11 Floor member 12 Driver's seat base 13 Footrest plate (footrest member)
14 Driver's seat 17 Canopy 18 Cover member 18E Upper opening 20 Base plate 20A Pipe insertion hole 20B Upper surface 20E Drain hole 22 Exhaust pipe 22B Lower end 22C Outer peripheral surface 23 Weld bead (bead)
24 Reinforcement plate (reinforcement member)
24A End edge portion 24B Lower end portion 24C Inclined portion 30 Intermediate pipe

Claims (6)

A self-propelled lower traveling body, an upper revolving body mounted on the lower traveling body and having a rear end capable of turning within a range defined with respect to a vehicle width of the lower traveling body, and the upper revolving body It consists of a working device provided on the front side,
The upper swing body includes a swing frame that forms a support structure, a counterweight provided at a rear end of the swing frame, an engine that is located on the front side of the counterweight and is mounted on the swing frame, and the engine A driver seat pedestal that is provided on the swivel frame and is attached to the driver seat, a footrest member that is provided on the front side of the driver seat pedestal and serves as a footrest portion for an operator seated on the driver seat, A small hydraulic excavator comprising a canopy provided above the seat, and an exhaust pipe disposed on the rear side of the canopy and extending upward from the counterweight and exhausting exhaust gas from the engine In
A through hole provided in the counterweight and penetrating between an inner surface and an outer surface of the counterweight;
A cover member provided on the outer surface side of the counterweight, covering the through-hole and having an upper end opened;
A base plate attached to the cover member, having a pipe insertion hole communicating with the opening, and having a lower end of the exhaust pipe fixed to the pipe insertion hole;
A reinforcing member provided on the lower side of the exhaust pipe, extending upward and downward, and fixed to the outer peripheral surface of the exhaust pipe and the upper surface of the base plate ;
The reinforcing member is formed by a reinforcing plate having an L-shaped cross section in which an intermediate portion in the width direction orthogonal to the upper and lower directions is bent in a mountain shape, and both end edges in the width direction of the reinforcing plate are outer circumferences of the exhaust pipe. small hydraulic excavator, characterized in that it has a configuration that will be affixed to the surface.   2. The counterweight according to claim 1, wherein the counterweight is provided with an intermediate pipe that extends through the through hole into the cover member and connects between a tail pipe of the engine and a lower end of the exhaust pipe. Small excavator.   2. The small hydraulic excavator according to claim 1, wherein a plurality of the reinforcing members are provided at equal intervals in the circumferential direction so as to cover an outer peripheral surface of the exhaust pipe.   The small hydraulic excavator according to claim 1, wherein an inclined portion is provided on a lower end side of the reinforcing member to release a bead when the exhaust pipe is welded to the base plate.   The base plate is provided with a drain hole penetrating upward and downward between the outer peripheral surface of the exhaust pipe and the reinforcing member in plan view when the reinforcing member is fixed to the lower side of the exhaust pipe. The small hydraulic excavator according to claim 1, which is configured. The driver seat base and the footrest member are integrated to form a floor member,
The small-sized hydraulic excavator according to claim 1, wherein the floor member is configured to be tiltable upward and downward with a front side as a fulcrum.

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