Working machinery

Abstract

This invention provides a work machine that can suppress vibrations in the driver's seat by reducing vibrations in the base frame caused by engine vibrations with a simple configuration. [Solution] The work machine comprises a base plate on which the engine is positioned above, and a seat support base that covers the engine from above and supports the driver's seat. The work machine comprises a vertical plate extending from one side of the engine on the base plate and extending from rear to front, and a reinforcing member erected on the base plate, connected to the vertical plate, and extending from the vertical plate to one side.

Description

Technical Field

[0001] The present invention relates to a working machine.

Background Art

[0002] Conventionally, a working machine having an engine mounted on a base frame such as a swivel frame is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a working machine having an engine mounted on a base frame, when the base frame vibrates due to the vibration of the engine, the vibration of the base frame is transmitted to the driver's seat via the seat support base, and the driver's seat vibrates. Therefore, it is desirable to suppress the vibration of the base frame due to the vibration of the engine with a simple configuration.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a working machine capable of suppressing the vibration of the base frame due to the vibration of the engine with a simple configuration and suppressing the vibration of the driver's seat.

Means for Solving the Problems

[0006] A working machine according to one aspect of the present invention is a working machine including a base plate on which an engine is disposed upward, and a seat support base that covers the engine from above and supports a driver's seat, the working machine including a vertical plate that extends on one side of the engine on the base plate and extends from the rear toward the front, and a reinforcing member that stands on the base plate, is connected to the vertical plate, and extends from the vertical plate to the one side. [Effects of the Invention]

[0007] With the above configuration, vibrations in the base frame caused by engine vibrations can be suppressed with a simple design, thereby reducing vibrations in the driver's seat. [Brief explanation of the drawing]

[0008] [Figure 1] This is a left side view showing a schematic configuration of a hydraulic excavator, which is an example of a work machine of the present invention. [Figure 2] This is a perspective view of the upper rotating body of the hydraulic excavator shown above, viewed from a diagonal rearward angle. [Figure 3] This is a schematic plan view showing the internal configuration of the machine room when the hydraulic excavator is cut in the horizontal plane containing line AA in Figure 1. [Figure 4] This is an exploded perspective view of the seat support base and support structure. [Figure 5] This is a plan view showing the various components on the slewing frame, with the above-mentioned support structure omitted from the illustration. [Figure 6] This is a perspective view showing the various components on the slewing frame, with the above-mentioned support structure omitted from the illustration. [Figure 7] This is a schematic rear view showing the internal configuration of the machine room described above. [Figure 8A] This is a schematic rear view showing an example of the arrangement of the left vertical plate and the first engine support on the above-mentioned rotating frame. [Figure 8B] This is a schematic rear view showing another example of the arrangement of the left vertical plate and the first engine support on the above-mentioned slewing frame. [Figure 9A] This is a schematic rear view showing another example of the reinforcing member shown in Figure 8A. [Figure 9B] This is a schematic rear view showing another example of the reinforcing member shown in Figure 8B. [Figure 10] This is a left side view showing the internal layout of the engine room. [Figure 11]It is a left side view showing the internal configuration of the engine room with the illustration of the left front support portion in FIG. 10 omitted. [Figure 12] It is a left side view showing other configurations of the hydraulic excavator. [Figure 13A] It is a perspective view showing the appearance of the exhaust tail pipe. [Figure 13B] It is an exploded perspective view of the exhaust tail pipe. [Figure 14A] It is a perspective view including a cut surface of the connection portion between the first pipe and the second pipe. [Figure 14B] It is a cross-sectional view of the connection portion.

Mode for Carrying Out the Invention

[0009] Regarding the embodiments of the present invention, the description based on the drawings is as follows.

[0010] 〔1. Schematic Configuration of the Working Machine〕 FIG. 1 is a left side view showing a schematic configuration of a hydraulic excavator 1 which is an example of a working machine according to an embodiment of the present invention. The hydraulic excavator 1 includes a lower traveling body 2, a working machine 3, and an upper revolving body 4.

[0011] In the present embodiment, the directions are defined as follows. The direction in which an operator (driver, operator) seated on the driver's seat 44a arranged in the operation unit 44 of the upper revolving body 4 faces forward is defined as "front", and the opposite direction is defined as "rear". With respect to the lower traveling body 2, when the upper revolving body 4 is in a non-revolving state (swing angle 0 degrees), the front-rear direction of the upper revolving body 4 coincides with the front-rear direction of the lower traveling body 2. In the drawings, the hydraulic excavator 1 in a state where the upper revolving body 4 is non-revolving with respect to the lower traveling body 2 is shown. Also, the left side as viewed from the operator seated on the driver's seat 44a is defined as "left", and the right side is defined as "right". Further, the gravitational direction perpendicular to the front-rear direction and the left-right direction is defined as the vertical direction, the upstream side in the gravitational direction is defined as "up", and the downstream side is defined as "down". In the drawings, if necessary, the front is indicated by the symbol "F", the rear by "B", the right by "R", the left by "L", the upper by "U", and the lower by "D".

[0012] (1-1. Lower Travel Unit) The lower travel unit 2 includes a pair of left and right crawlers 21, a pair of left and right travel motors 22, and a blade 23. By driving the left and right travel motors 22 to drive the left and right crawlers 21 respectively, the hydraulic excavator 1 can be moved forward and backward. The travel motor 22 is composed of a hydraulic motor. The blade 23 for performing leveling work and the like is provided on the front side of the lower travel unit 2. The blade 23 is rotated by a blade cylinder (not shown). The blade cylinder is composed of a hydraulic cylinder.

[0013] (1-2. Working Equipment) The working equipment 3 includes a boom 31, an arm 32, and a bucket 33. By driving the boom 31, the arm 32, and the bucket 33 independently, excavation work such as earth and sand can be performed.

[0014] The boom 31 has a lower boom 31a, an upper boom 31b, and an arm stay 31c. The base end portion of the lower boom 31a is connected to the right front portion 4a (see FIG. 3) of the upper swing body 4 so as to be rotatable in the vertical direction and the front-rear direction. The tip end portion of the boom cylinder (not shown) is connected to the tip end portion of the lower boom 31a. The base end portion of the boom cylinder is connected to the right front portion 4a of the upper swing body 4. More specifically, the boom cylinder is disposed in front of the lower boom 31a. The boom cylinder is movable in an extendable and retractable manner. When the boom cylinder extends and retracts, the lower boom 31a rotates in the vertical direction and the front-rear direction with respect to the upper swing body 4.

[0015] The base end portion of the upper boom 31b is connected to the tip end portion of the lower boom 31a so as to be rotatable in the left-right direction. The arm stay 31c is connected to the tip end portion of the upper boom 31b so as to be rotatable in the left-right direction. The base end portion of the offset cylinder 31b1 is connected to the left side surface of the base end portion of the upper boom 31b. The tip end portion of the offset cylinder 31b1 is connected to the left side surface of the arm stay 31c. The offset cylinder 31b1 is movable in an extendable and retractable manner. The left side surface of the arm stay 31c and the left side surface of the tip end portion of the lower boom 31a are connected by a link rod 31b2.

[0016] When the offset cylinder 31b1 extends or retracts, the upper boom 31b rotates laterally relative to the lower boom 31a, and the arm stay 31c moves laterally (offset). At this time, the arm stay 31c rotates laterally relative to the upper boom 31b. As a result, the arm stay 31c moves laterally relative to the lower boom 31a without rotating laterally.

[0017] The base end of the arm 32 is connected to the arm stay 31c so as to be rotatable in the vertical and longitudinal directions. The tip of the arm cylinder 32a is connected to the base end of the arm 32. The arm stay 31c is connected to the intermediate section between the tip and base end of the arm cylinder 32a. The arm cylinder 32a is movable so as to be able to extend and retract. When the arm cylinder 32a extends or retracts, the arm 32 rotates in the vertical and longitudinal directions relative to the arm stay 31c.

[0018] The bucket 33 is connected to the tip of the arm 32 so as to be rotatable in the vertical and longitudinal directions. The bucket 33 is also connected to the arm 32 via a bucket link 34. The base end of the bucket cylinder 33a is connected to the base end of the arm 32. The tip of the bucket cylinder 33a is connected to the bucket link 34. The bucket cylinder 33a is movable so as to be able to extend and retract. When the bucket cylinder 33a extends or retracts, the bucket 33 rotates relative to the arm 32 in the vertical and longitudinal directions.

[0019] The boom cylinder, offset cylinder 31b1, arm cylinder 32a, and bucket cylinder 33a are composed of hydraulic cylinders.

[0020] (1-3. Upper rotating body) The upper slewing body 4 is located above the lower traveling body 2 and is rotatably mounted relative to the lower traveling body 2 via a slewing bearing (not shown). The upper slewing body 4 comprises a slewing frame 41, a slewing motor 42, a machine room 43, and an operating unit 44.

[0021] The upper rotating body 4 rotates via the aforementioned rotating bearings, driven by a rotating motor 42 located on the rotating frame 41. The rotating motor 42 is a hydraulic motor.

[0022] The engine EG is housed in the machine room 43. The engine EG is the prime mover that powers the hydraulic excavator 1. The engine EG is composed of a diesel engine, but is not limited to this; for example, it may be composed of a gasoline engine. The engine EG is mounted on the slewing frame 41, which is the base plate. In other words, the hydraulic excavator 1 has a base plate (slewing frame 41) in which the engine EG is positioned above.

[0023] The machine room 43 houses the engine EG and a hydraulic pump P (see Figure 3). The hydraulic pump P supplies hydraulic fluid (pressurized oil) to the hydraulic motors and hydraulic cylinders. The hydraulic motors include, for example, the left and right travel motors 22 and the slewing motor 42. The hydraulic cylinders include, for example, the blade cylinder, boom cylinder, offset cylinder 31b1, arm cylinder 32a, and bucket cylinder 33a. The hydraulic motors and hydraulic cylinders driven by hydraulic fluid are collectively called hydraulic actuators.

[0024] The driver's unit 44 is located on the upper left side of the upper slewing body 4. More specifically, the driver's unit 44 is located to the left of the work machine 3. As shown in Figure 1, the driver's unit 44 is provided with a driver's seat 44a. Multiple control members 44b are arranged around the driver's seat 44a. The multiple control members 44b consist of levers, switches, pedals, etc. When the operator sits in the driver's seat 44a and operates the multiple control members 44b, the hydraulic actuator is driven. This enables the lower traveling body 2 to travel, the blade 23 to perform leveling work, the work machine 3 to perform excavation work, the upper slewing body 4 to rotate, and so on.

[0025] (1-4. Canopy) The upper rotating body 4 is provided with a canopy 100. In other words, the hydraulic excavator 1 is equipped with a canopy 100. The canopy 100 is positioned to cover the area above the driver's seat 44a.

[0026] Figure 2 is a perspective view of the upper rotating body 4 from the rear at an oblique angle. The canopy 100 has three support columns. That is, the canopy 100 is composed of a three-column canopy. More specifically, the canopy 100 includes a first support column 101, a second support column 102, and a third support column 103.

[0027] The first support column 101 is erected behind the driver's seat 44a, to the left of the seat support base 43S, which will be described later. The second support column 102 is erected on the seat support base 43S to the right of the first support column 101. The third support column 103 is erected on the floor 44F of the driver's compartment 44, to the right and in front of the driver's seat 44a. As a result, the third support column 103 is positioned in front of the second support column 102.

[0028] In this embodiment, the left side, which is one side in the left-right direction, is also referred to as "one lateral side," and the right side, which is the other side, is also referred to as "the other lateral side." In this case, the first support column 101 is erected on one lateral side of the seat support base 43S, and the second support column 102 is erected on the other lateral side of the seat support base 43S relative to the first support column 101.

[0029] The canopy 100 further includes a roof section 104. The roof section 104 is supported by a first support 101, a second support 102, and a third support 103 via a pillar 105 and covers the area above the driver's seat 44a. The pillar 105 extends along the front edge 104F, the left edge 104L, and the rear edge 104B of the roof section 104 and connects to them. More specifically, one end of the pillar 105 connects to the upper end of the third support 103. From the aforementioned end (the end connected to the third support 103), the pillar 105 extends to the left along the front edge 104F, then to the rear along the left edge 104L, and then to the right along the rear edge 104B, connecting to the upper end of the second support 102. The first support column 101 is connected to the portion of the pillar 105 that supports the rear edge 104B of the roof section 104.

[0030] A skylight 104a is provided in the roof section 104. The skylight 104a is made of, for example, a transparent material. The transparent material is made of, for example, resin (e.g., polycarbonate), but may also be made of glass. The operator seated in the driver's seat 44a can see upwards through the skylight 104a. This allows the operator to visually confirm the posture and operation of, for example, the work equipment 3 (see Figure 1) located to the right of the driver's seat 44.

[0031] The canopy 100 is further provided with a right window 106. The right window 106 is positioned between the third support column 103 and the second support column 102 and is supported by the third support column 103 and the second support column 102 via a window frame portion 106a. The right window 106 is made of, for example, a transparent material. The transparent material is made of resin or glass, similar to the skylight 104a. The operator seated in the driver's seat 44a can see to the right through the right window 106.

[0032] Two guide frames 107 are provided to the left of the right window 106. The two guide frames 107 are spanned in the front-to-back direction between the third support column 103 and the second support column 102, and are positioned apart in the vertical direction. Each guide frame 107 is provided for the purpose of reinforcing the canopy 100 and ensuring the safety of the operator. For example, even if the hydraulic excavator 1 were to tip over, each guide frame 107 would prevent the operator from being thrown through the right window 106 to the right side (towards the work machine 3). Note that the number of guide frames 107 is not limited to the two mentioned above; there may be one or three or more.

[0033] Below the right window 106, a right-side wall section 108 (see Figure 1) is positioned. The right-side wall section 108 separates the driver's seat 44a from the work equipment 3.

[0034] (1-5. Details of the driver's unit) As shown in Figure 2, the driver's seat 44a of the upper rotating body 4 is supported from below by a seat support base 43S. The seat support base 43S is constructed by connecting multiple metal plates in a stepped manner from the front lower part to the rear upper part of the driver's seat 44a (see Figure 4). The seat support base 43S covers the engine EG from above (see Figure 1). In other words, the hydraulic excavator 1 is equipped with a seat support base 43S that covers the engine EG from above and supports the driver's seat 44a.

[0035] The driver's unit 44 is equipped with the following control members 44b as described above: a right operating lever 44b1, a left operating lever 44b2, a function limiting lever 44b3, a pair of travel levers 44b4, and a pedal 44b5 (see Figure 3).

[0036] The right operating lever 44b1 is located to the right of the driver's seat 44a. The left operating lever 44b2 and the function limiting lever 44b3 are located to the left of the driver's seat 44a. The function limiting lever 44b3 is a lever for switching the drive of the hydraulic actuator on and off and is provided to limit the function of the hydraulic actuator as needed. A pair of travel levers 44b4 and pedals 44b5 are located in front of the driver's seat 44a.

[0037] A monitor 60 is located in the driver's unit 44. The monitor 60 is a display device that shows various information. For example, the monitor 60 displays various settings for the hydraulic excavator 1, fuel level, hour meter, and, if a surveillance camera is installed, images taken by the surveillance camera. The monitor 60 is supported by stays or the like on the right frame 108a (see Figure 1) of the canopy 100. The right frame 108a is a frame that runs along the upper edge of the right side wall portion 108 of the canopy 100 and extends diagonally upward from the front to the rear.

[0038] (1-6. External configuration of the machine room) As shown in Figure 2, on the seat support base 43S, a communication unit 43a is positioned to the right of the second support column 102 of the canopy 100. The communication unit 43a includes an antenna and a positioning unit and is provided for communication with the outside and measurement of the vehicle's position. Further to the right of the communication unit 43a on the seat support base 43S, a lamp 43b is provided. The lamp 43b lights up when the hydraulic excavator 1 is in operation or to warn the surroundings, drawing attention to the surroundings. Further to the right of the lamp 43b on the seat support base 43S, an opening / closing cover 43c is connected so as to open forward and rotate vertically. By rotating the opening / closing cover 43c upward and opening it, it becomes possible to access, for example, the internal fuel tank and refuel the fuel tank.

[0039] The machine room 43 is provided with a right-side cover 43R, a rear cover 43B, a left-side cover 43L, and a lower left cover 43LU. The right-side cover 43R is a cover member that forms the right-side wall of the machine room 43. The right-side cover 43R is provided with an opening (not shown). This opening is provided to allow air to circulate between the inside and outside of the machine room 43. By directing this air to the heat exchanger HE (see Figure 3), which will be described later, the cooling water passing through the heat exchanger HE can be cooled, thereby cooling the engine EG. As a safety measure, for example, a mesh-like guard is provided at the opening, but the shape of the guard is not limited to a mesh shape.

[0040] The rear cover 43B is a cover member that forms the rear wall of the machine room 43. A counterweight 43W is attached below the rear cover 43B to balance the weight with the work machine 3. The left side cover 43L is a cover member that forms the left side wall of the machine room 43. The lower left cover 43LU is a cover member that forms the side wall below the left side cover 43L. The right side cover 43R, the left side cover 43L, and the lower left cover 43LU are detachably attached to the machine room 43 by bolts or the like. The rear cover 43B is rotatably attached to the rear of the machine room 43, for example, by opening to the right, but it may also be detachably attached by bolts or the like.

[0041] [2. Internal configuration of the machine room] Figure 3 is a schematic plan view showing the internal configuration of the machine room 43 when the hydraulic excavator 1 is cut in a horizontal plane including line AA in Figure 1. Line AA passes through the engine EG.

[0042] Within the machine room 43, a hydraulic pump P is located to the left of the engine EG. On the other hand, within the machine room 43, a heat exchanger HE is located to the right of the engine EG. The heat exchanger HE includes a radiator and an oil cooler.

[0043] The radiator is a first heat exchanger connected to the water jacket of the engine EG via piping, and cools the refrigerant passing through the water jacket. By cooling the refrigerant through heat exchange in the radiator and supplying the refrigerant from the radiator to the engine EG (water jacket), the engine EG can be cooled. The refrigerant is, for example, coolant.

[0044] The oil cooler is a second heat exchanger connected to the oil passages that circulate via the aforementioned hydraulic pump P and hydraulic actuators. The oil cooler cools the hydraulic fluid flowing through the oil passages by heat exchange when driven by the hydraulic pump P. The oil cooler is arranged side by side with the radiator, for example, in the front-to-back direction. The oil cooler may also be arranged so that at least a portion of it overlaps with the radiator.

[0045] A fan F is positioned between the engine EG and the heat exchanger HE. The rotational power of the engine EG's crankshaft is transmitted to the fan F via a fan belt and fan pulley, thereby driving the fan F to rotate.

[0046] When fan F is driven, it blows air toward the heat exchanger HE. More specifically, when fan F is driven, air is drawn into the machine room 43 from, for example, a vent (not shown) provided in the slewing frame 41, and the drawn air flows toward the heat exchanger HE. This cools the heat exchanger HE. In other words, the refrigerant (cooling water) flowing through the radiator of the heat exchanger HE is cooled, and the hydraulic oil flowing through the oil cooler is also cooled.

[0047] The air that has cooled the heat exchanger HE flows through the gaps in the heat exchanger HE or along the surface of the heat exchanger HE towards the opening in the right side cover 43R, and is discharged from the opening to the outside of the machine room 43. This method of cooling the heat exchanger HE with a flow of cooling air is called the "discharge type". Alternatively, the heat exchanger HE may be cooled by driving a fan F to draw air into the machine room 43 from the opening in the right side cover 43R and directing the drawn-in air onto the heat exchanger HE. This method of cooling the heat exchanger HE with a flow of cooling air is called the "suction type".

[0048] The fan F described above is surrounded by a housing CA. Housing CA is a fan shroud with openings on the heat exchanger HE side and the engine EG side. The cooling air generated by the operation of fan F passes through the inside of housing CA and flows, for example, from the engine EG side towards the heat exchanger HE side.

[0049] Within the machine room 43, a bracket BR is positioned to the left of the engine EG. As a result, the bracket BR faces the left side cover 43L within the machine room 43. The bracket BR is made of, for example, a metal plate and is supported by the left support frame 81 (see Figure 4) within the machine room 43.

[0050] The bracket BR is fitted with the first controller 70a. The first controller 70a is a type of controller 70. The first controller 70a is an electronic control controller and consists of an electronic control unit, also known as an ECU (Electronic Control Unit). For example, the first controller 70a electronically controls the hydraulic pump P and the control valve CV.

[0051] Here, the control valve CV is located below the floor 44F of the operating unit 44, as shown in Figure 3. The control valve CV is an assembly of directional control valves corresponding to each hydraulic actuator. The directional control valves control the flow direction and flow rate of the hydraulic fluid supplied to the corresponding hydraulic actuator. In this embodiment, an electromagnetic control method is used for the control valve CV (each directional control valve). That is, by outputting a control signal from the controller 70 to the electromagnetic proportional valve of the control valve CV, the flow direction and flow rate of the hydraulic fluid supplied from the hydraulic pump P to the hydraulic actuator are controlled.

[0052] The first controller 70a is mounted on the first surface BR1, which is one side of the bracket BR. The first surface BR1 is one side surface of the bracket BR, that is, the side facing the left side cover 43L (the side opposite to the side facing the hydraulic pump P).

[0053] A second controller 70b is located within the machine room 43. The second controller 70b is also a type of controller 70, similar to the first controller 70a, and is composed of, for example, an ECU. The second controller 70b controls the electrical components located inside the hydraulic excavator 1 (for example, the monitor 60 in Figure 2) and is an integrated controller that works in conjunction with the first controller 70a to control the hydraulic pump P and the like.

[0054] The second controller 70b is mounted on the mounting bracket ST. The mounting bracket ST is fixed to the front wall 43S1 extending upward from the front lower part of the driver's seat 44a in the seat support base 43S. As a result, the second controller 70b is positioned on one side of the hydraulic pump P and in front of the bracket BR.

[0055] A third controller 70c is further arranged within the machine room 43. The third controller 70c is also a type of controller 70, similar to the first controller 70a and the second controller 70b, and is composed of, for example, an ECU. The third controller 70c is mounted on the second surface BR2, which is the other surface of the bracket BR. The second surface BR2 is the surface of the bracket BR opposite to the first surface BR1, that is, the surface facing the hydraulic pump P.

[0056] The third controller 70c is a controller for machine guidance or machine control. The third controller 70c is an optional controller; that is, it is installed as needed.

[0057] For example, if a sensor for detecting posture is attached to a predetermined position on the work machine 3 (e.g., the arm 32), the third controller 70c can display guidance on the monitor 60 (see Figure 2) based on the detection results of the sensor. This allows the operator to operate the control member 44b so that the bucket 33 is in the desired position, based on the guidance displayed on the monitor 60. In this case, machine guidance that guides the operation of the work machine 3 is realized. Furthermore, if the sensor detects the position information of the cutting edge of the bucket 33, the third controller 70c can also realize machine control based on the position information. In machine control, the work machine 3 is automatically operated by the third controller 70c so that the cutting edge of the bucket 33 is in the desired position based on the position information.

[0058] In this embodiment, the bracket BR is positioned such that, for example, when viewed from the rear of the hydraulic excavator 1, a portion of it is to the left of the hydraulic pump P and above the hydraulic pump P. Alternatively, the entire bracket BR may be positioned to the left of the hydraulic pump P and above the hydraulic pump P when viewed from the rear of the hydraulic excavator 1. In other words, the bracket BR only needs to be positioned such that, when viewed from the rear, at least a portion of it is to one side of the hydraulic pump P and above the hydraulic pump P.

[0059] [3. Regarding the support structure of the seat support base] The seat support base 43S described above is supported on the swivel frame 41 via the support structure 80 shown in Figure 4. Figure 4 is an exploded perspective view of the seat support base 43S and the support structure 80. The bracket BR described above is supported by the support structure 80. The details of the support structure 80 will be described below.

[0060] As shown in Figure 4, the support structure 80 is composed of a left support frame 81, a right support frame 82, and an upper frame 83.

[0061] The left support frame 81 is positioned one side to the left of the center in the left-right direction within the machine room 43 (see Figure 3, etc.). The left support frame 81 has a first upright section 811, a second upright section 812, and a connecting section 813.

[0062] The first erected section 811 is erected inside the machine room 43. More specifically, the first erected section 811 is erected on the left front support section 91 on the slewing frame 41. The left front support section 91 is erected on one side (left side) of the slewing frame 41, and near the center in the front-rear direction. The left front support section 91 is fastened to the slewing frame 41, for example, with bolts, but may also be fixed by welding. A flat plate-shaped first flange section F1 is provided at the upper end of the left front support section 91 by welding or the like. The left front support section 91 supports the first erected section 811 via the first flange section F1 and also supports the front wall 43S1 of the seat support base 43S. Therefore, the left front support section 91 constitutes a support base support section that supports the seat support base 43S. The first erected section 811 is fixed to the first flange section F1 by bolts or the like, and the front wall 43S1 is fixed to the first flange section F1 by welding or the like, but the fixing method is not particularly limited.

[0063] The second upright section 812 is erected inside the machine room 43, behind the first upright section 811. More specifically, the second upright section 812 is erected at the intersection of the left vertical plate 92 and the horizontal plate 93 on the slewing frame 41. A flat plate-shaped second flange section F2 is provided at the intersection. The second upright section 812 is fastened to the second flange section F2, for example, with bolts, but may also be fixed by welding. The horizontal plate 93 is erected at the rear of the slewing frame 41 and extends in the left-right direction. The left vertical plate 92 is erected to the right of the first upright section 811 on the slewing frame 41 and extends forward from the left end of the horizontal plate 93. The left vertical plate 92 and the horizontal plate 93 are provided to increase the rigidity of the slewing frame 41 against the weight of the work machine 3. The left vertical plate 92 and the horizontal plate 93 are attached to the slewing frame 41, for example, by welding. The second erected section 812 extends upward from the first erected section 811.

[0064] The connecting portion 813 connects the first upright portion 811 and the second upright portion 812. More specifically, the connecting portion 813 is connected to the first upper end portion 811a (see Figure 10), which is the upper end of the first upright portion 811, and to the intermediate portion 812H in the vertical direction of the second upright portion 812. The intermediate portion 812H is located between the second upper end portion 812a, which is the upper end of the second upright portion 812, and the second lower end portion 812b, which is the lower end of the second upright portion 812. The position of the intermediate portion 812H in the vertical direction is not particularly limited. For example, the intermediate portion 812H may be located midway between the second upper end portion 812a and the second lower end portion 812b, or it may be located closer to the second upper end portion 812a than the intermediate portion, or it may be located closer to the second lower end portion 812b than the intermediate portion.

[0065] In this embodiment, the connecting portion 813 is integrally formed with the first erecting portion 811, but it may also be formed as a separate component from the first erecting portion 811 and connected to the first erecting portion 811. Furthermore, the connecting portion 813 is bolted to the second erecting portion 812 at the intermediate portion 812H, but it may also be integrally formed with the second erecting portion 812. The connecting portion 813 spans the first erecting portion 811 and the second erecting portion 812 in the front-rear direction (more precisely, diagonally to the front-rear direction in a plan view).

[0066] Furthermore, the first upright section 811 is supported by the left front support section 91 via the first flange section F1, and the second upright section 812 is supported by the left vertical plate 92 via the second flange section F2. Therefore, by connecting the first upright section 811 and the second upright section 812 with the connecting section 813, the left support frame 81 is spanned between the left front support section 91 and the left vertical plate 92.

[0067] The bracket BR described above is fixed to the first erecting portion 811 and the connecting portion 813 of the left support frame 81 by bolts or the like.

[0068] The right support frame 82 is positioned in the machine room 43 to the right, rather than to the center in the left-right direction. The right support frame 82 has a first frame 821, a second frame 822, and a third frame 823.

[0069] The second frame 822 is erected at the intersection of the horizontal plate 93 and the right vertical plate 94 on the slewing frame 41. A flat third flange portion F3 is provided at the intersection. The second frame 822 is fastened to the third flange portion F3, for example, with bolts, but may also be fixed by welding. The right vertical plate 94 is erected on the slewing frame 41 and extends forward from the right end of the horizontal plate 93. The right vertical plate 94, like the left vertical plate 92 and the horizontal plate 93, is provided to increase the rigidity of the slewing frame 41 against the weight of the work machine 3. The right vertical plate 94 is attached to the slewing frame 41, for example, by welding.

[0070] The first frame 821 is positioned in front of the second frame 822 inside the machine room 43. The first frame 821 is fixed to the side of the right vertical plate 94 with bolts or the like. The third frame 823 is connected to the upper end of the first frame 821 and extends rearward, and is connected to the upper end of the second frame 822. In this embodiment, the third frame 823 is integrally formed with the first frame 821, but it may also be formed as a separate component from the first frame 821 and connected to the first frame 821. Also, the third frame 823 is connected to the second frame 822 via a connecting stay 824, but it may also be integrally formed with the second frame 822. The third frame 823 spans the first frame 821 and the second frame 822 in the front-rear direction.

[0071] The upper frame 83 is connected to the upper end of the left support frame 81 (the second upper end portion 812a of the second erected portion 812) and the upper end of the right support frame 82 (the connecting stay 824) by welding or the like. The upper frame 83 extends in the left-right direction. As shown in Figure 4, the upper frame 83 is fastened to the lower surface of the seat support base 43S by bolts or the like. As a result, the seat support base 43S is supported by the support structure 80 at a position rearward of the driver's seat 44a.

[0072] The left support frame 81 of the support structure 80 supports the seat support base 43S via the upper frame 83. Thus, it can be said that the hydraulic excavator 1 of this embodiment is equipped with a left support frame 81 that supports the seat support base 43S at a position rearward from the driver's seat 44a.

[0073] [4. Regarding the engine support structure] Next, the support structure of the engine EG (see Figure 1) described above will be explained. Figures 5 and 6 are plan and perspective views, respectively, showing the various components on the slewing frame 41 with the support structure 80 omitted from the illustration. Figure 7 is a schematic rear view showing the internal configuration of the machine room 43. Note that in Figure 7, the support structure 80 and the cross plate 93 are omitted from the illustration for convenience.

[0074] As shown in Figures 5 and 6, the slewing frame 41 is provided with a first engine support ES1, a second engine support ES2, a third engine support ES3, and a fourth engine support ES4. As shown in Figure 5, the first engine support ES1 is erected on the slewing frame 41 by welding and supports the left front of the engine EG. The second engine support ES2 is composed of the front part of the second flange portion F2 described above and supports the left rear of the engine EG. The third engine support ES3 is erected on the slewing frame 41 by welding and supports the right rear of the engine EG. The fourth engine support ES4 is erected on the slewing frame 41 via a relay platform ES4a (see Figure 6) and supports the right front of the engine EG. In this embodiment, the vertical lengths of the first engine support ES1, the second engine support ES2, the third engine support ES3, and the fourth engine support ES4 are different from each other, but can be set as appropriate.

[0075] As shown in Figure 7, the left rear of the engine EG is supported by the second engine support ES2 via a vibration-damping member 96. The vibration-damping member 96 is composed of vibration-damping rubber. The vibration-damping member 96 absorbs vibrations of the engine EG, reducing the vibrations transmitted to the swing frame 41 via the second engine support ES2. The right rear of the engine EG is also supported by the third engine support ES3 via a vibration-damping member 96. Although not shown, the left front of the engine EG is similarly supported by the first engine support ES1 via a vibration-damping member. Similarly, the right front of the engine EG is also supported by the fourth engine support ES4 via a vibration-damping member.

[0076] As shown in Figure 5, the left vertical plate 92 described above is positioned on the left side of the engine EG on the slewing frame 41 and extends in the front-rear direction. From this, it can be said that the hydraulic excavator 1 of this embodiment is equipped with a left vertical plate 92 that extends on one side of the engine EG on the slewing frame 41 (base plate) and extends from rear to front. Note that "extending from rear to front" here refers to extending in a direction along the front-rear direction, but extending with a slight inclination in the left-right direction relative to the front-rear direction is also included in "extending from rear to front".

[0077] Furthermore, as shown in Figures 6 and 7, the left front support portion 91 on the slewing frame 41 is positioned to the left of the left vertical plate 92. From this, it can be said that the hydraulic excavator 1 of this embodiment is equipped with a left front support portion 91 (support base support portion) that is erected on one side of the left vertical plate 92 on the slewing frame 41 (base plate) and supports the seat support base 43S.

[0078] Furthermore, as shown in Figures 5 and 6, the first engine support ES1 is positioned on the slewing frame 41 to the right of the left vertical plate 92. Thus, it can be said that the hydraulic excavator 1 of this embodiment is equipped with a first engine support ES1 (engine support) that is positioned on the slewing frame 41 alongside the left vertical plate 92 and supports the engine EG.

[0079] [5. Regarding reinforcing members] As shown in Figures 5 to 7, the hydraulic excavator 1 of this embodiment further comprises a reinforcing member RM. The reinforcing member RM is composed of, for example, a metal plate-shaped member, or a plate-shaped member that has been bent or curved, and is also called a rib.

[0080] The reinforcing member RM is erected on the swivel frame 41 (base plate) by welding or the like. The reinforcing member RM is connected to the left side (one side surface) of the left vertical plate 92 by welding or the like. The reinforcing member RM extends from the left vertical plate 92 toward the left (one side). In this embodiment, as shown in Figures 5 and 6, the reinforcing member RM extends from the left vertical plate 92 toward the left by repeatedly bending, but it may also extend in a straight line. Also, in Figure 5, the reinforcing member RM extends diagonally backward as it moves toward the left, but it may also extend diagonally forward as it moves toward the left, or it may extend straight toward the left (to the left, intersecting the front-rear direction at a 90° angle in a plan view).

[0081] As described above, in this embodiment, a reinforcing member RM is provided on the slewing frame 41 in addition to the left vertical plate 92. In this configuration, the slewing frame 41 is reinforced by the left vertical plate 92 in the front-rear direction and by the reinforcing member RM in the left-right direction. As a result, the rigidity of the slewing frame 41 is increased (compared to a configuration without the reinforcing member RM), so vibrations of the slewing frame 41 caused by engine EG vibrations can be effectively suppressed. Therefore, vibrations of the seat support 43S and the driver's seat 44a caused by vibrations of the slewing frame 41 due to engine EG vibrations can be effectively suppressed. In other words, vibrations of the driver's seat 44a can be suppressed with a simple configuration of providing a reinforcing member RM on the slewing frame 41.

[0082] As shown in Figure 7, in this embodiment, the reinforcing member RM is positioned between the left vertical plate 92 and the left front support portion 91 when viewed from the rear of the hydraulic excavator 1. In this embodiment, the reinforcing member RM extends from the left vertical plate 92 toward the left front support portion 91. The reinforcing member RM may also extend toward a position behind or in front of the left front support portion 91 from the left vertical plate 92.

[0083] The front wall 43S1 of the seat support base 43S is supported by the left front support portion 91. Therefore, when vibrations from the engine EG are transmitted to the left front support portion 91 via the slewing frame 41, the seat support base 43S vibrates, causing the driver's seat 44a to vibrate. Consequently, in order to suppress the vibration of the driver's seat 44a, it is desirable to suppress the vibration of the seat support base 43S, and for this purpose, it is desirable to suppress the vibration of the slewing frame 41 between the left vertical plate 92, which is located on one side of the engine EG, and the left front support portion 91. From this viewpoint, it is desirable to place a reinforcing member RM between the left vertical plate 92 and the left front support portion 91 in a rear view to increase the rigidity of the slewing frame 41 between the left vertical plate 92 and the left front support portion 91.

[0084] In particular, from the viewpoint of effectively suppressing vibrations of the slewing frame 41 transmitted from the left vertical plate 92 toward the left front support portion 91, and reliably suppressing vibrations of the driver's seat 44a via the left front support portion 91 and the seat support base 43S, it is desirable that the reinforcing member RM has the following configuration. That is, as in this embodiment, it is desirable that the reinforcing member RM extends on the slewing frame 41 from the left vertical plate 92 toward the left front support portion 91.

[0085] In this embodiment, as shown in Figures 5 and 6, the reinforcing member RM is positioned between the engine support and the left front support 91. Here, the engine support is the first engine support ES1 that supports the front of one side of the engine EG. In other words, the reinforcing member RM is positioned on the swing frame 41 on the vibration transmission path of the engine EG from the first engine support ES1 to the left front support 91. In this configuration, the vibration of the engine EG is transmitted to the swing frame 41 via the first engine support ES1, and then from the swing frame 41 to the left front support 91, which is suppressed by the positioning of the reinforcing member RM. As a result, vibration of the driver's seat 44a via the left front support 91 and the seat support base 43S is more reliably suppressed.

[0086] As shown in Figures 5 and 6, the first engine support ES1, which serves as the engine support, is positioned to the right of the left vertical plate 92, that is, on the other side. With this positional relationship between the first engine support ES1 and the left vertical plate 92, it is easy to realize a configuration in which a reinforcing member RM extending from the left vertical plate 92 to one side is positioned between the first engine support ES1 and the left front support 91.

[0087] As shown in Figure 5, the reinforcing member RM is positioned in front of the rear end EG-B of the engine EG in a plan view. For example, the reinforcing member RM is positioned in front of the crankshaft of the engine EG. In a side view, the reinforcing member RM may be positioned overlapping the engine EG in the longitudinal direction, or it may be positioned in front of the engine EG. In this case, even if the engine EG is positioned rearward on the slewing frame 41, the reinforcing member RM can be positioned near the center of the slewing frame 41 in the longitudinal direction. This effectively suppresses vibrations of the slewing frame 41.

[0088] Figure 8A is a schematic rear view showing an example of the arrangement of the left vertical plate 92 and the first engine support ES1 on the slewing frame 41. In this embodiment, as shown in Figure 8A, the left vertical plate 92 is positioned away from the first engine support ES1. In this arrangement, vibrations of the first engine support ES1 due to engine EG vibrations are not directly transmitted to the left vertical plate 92, thus suppressing vibrations of the left vertical plate 92 due to engine EG vibrations. As a result, vibrations of the slewing frame 41 to which the left vertical plate 92 is fixed are suppressed, and vibrations of the driver's seat 44a are suppressed.

[0089] Figure 8B is a schematic rear view showing another example of the arrangement of the left vertical plate 92 and the first engine support ES1 on the slewing frame 41. The left vertical plate 92 may be arranged in connection with the first engine support ES1. For example, the left vertical plate 92 may be integrated with the first engine support ES1 by welding. In this configuration, vibrations of the first engine support ES1 due to engine EG vibrations are transmitted to the slewing frame 41 via the left vertical plate 92, making the slewing frame 41 more susceptible to vibration. Therefore, providing a reinforcing member RM on the slewing frame 41 is very effective in suppressing vibrations of the slewing frame 41.

[0090] Furthermore, as shown in Figures 8A and 8B, the reinforcing member RM may be positioned separately from the left front support portion 91. In this configuration, the left front support portion 91 and the reinforcing member RM can be fixed to the slewing frame 41 separately, thus improving ease of assembly. For example, the reinforcing member RM can be fixed to the slewing frame 41 by welding, and then the left front support portion 91 can be fixed by bolting.

[0091] Figure 9A is a schematic rear view showing another configuration example of the reinforcing member RM shown in Figure 8A. Figure 9B is a schematic rear view showing another configuration example of the reinforcing member RM shown in Figure 8B. As shown in Figures 9A and 9B, the reinforcing member RM may be arranged in connection with the left front support portion 91. For example, the reinforcing member RM may be integrated with the left front support portion 91 by welding. When the reinforcing member RM and the left front support portion 91 are connected and integrated, the reinforcing member RM and the left front support portion 91 as a whole perform a function of reinforcing the slewing frame 41, thereby increasing the rigidity of the slewing frame 41. As a result, vibration of the slewing frame 41 due to engine EG vibration is effectively suppressed, and vibration of the driver's seat 44a is effectively suppressed.

[0092] In this embodiment, as shown in Figures 8A, 8B, 9A, and 9B, the reinforcing member RM has an inclined portion RMc. The inclined portion RMc is a part of the reinforcing member RM that has a slope in which the height decreases as it moves from the left vertical plate 92 toward the left (one side). The inclined portion RMc may be provided on a part of the reinforcing member RM, or it may be provided on the entire reinforcing member RM. In other words, the reinforcing member RM may be configured to have an inclined portion RMc and a portion with a constant height, or it may be composed only of an inclined portion RMc. Furthermore, the reinforcing member RM may be provided with multiple inclined portions RMc, and the height may decrease in stages as it moves from the left vertical plate 92 toward the left. In addition, the height of the reinforcing member RM may change linearly or curvedly.

[0093] Thus, as the reinforcing member RM has an inclined portion RMc, the height of the second end RM2 is lower than the height of the first end RM1 in the reinforcing member RM. Here, the first end RM1 is the end of the reinforcing member RM that is connected to the left vertical plate 92. The second end RM2 is the end of the reinforcing member RM that is opposite to the left vertical plate 92 relative to the first end RM1. In other words, the reinforcing member RM has a first end RM1 and a second end RM2, and the height of the second end RM2 is lower than that of the first end RM1.

[0094] When the reinforcing member RM is configured in this way, if the thickness of the reinforcing member RM is kept constant, the volume of the second end RM2 side is physically reduced compared to the first end RM1 side, making it lighter. As a result, compared to a configuration where the height of the reinforcing member RM is uniform throughout, for example, the upright side of the second end RM2 of the reinforcing member RM on the slewing frame 41 is suppressed from vibrating due to the weight of the reinforcing member RM itself. This further suppresses vibration of the driver's seat 44a. In addition, since the volume of the second end RM2 side of the reinforcing member RM is reduced compared to a configuration where the height of the reinforcing member RM is uniform throughout, the material cost of the reinforcing member RM is also reduced.

[0095] Figures 10 and 11 are left side views showing the internal configuration of the engine room 43, respectively. However, in Figure 11, the left front support portion 91 shown in Figure 10 is omitted. In this embodiment, as shown in Figure 11, the reinforcing member RM is positioned in front of the left support frame 81 on the slewing frame 41. More specifically, on the left support frame 81, when the position of the front end of the first lower end portion 811b (referring to the flange portion) of the first upright portion 811 is taken as P1, the reinforcing member RM is positioned in front of position P1.

[0096] In this arrangement of the reinforcing member RM, vibrations in the front portion of the seat support base 43S (for example, the portion below the driver's seat 44a) can be suppressed by the reinforcement of the pivot frame 41 by the reinforcing member RM, while vibrations in the rear portion of the seat support base 43S (for example, the portion behind the driver's seat 44a) can be suppressed by the support provided by the left support frame 81 located behind the reinforcing member RM. This ensures that vibrations in the driver's seat 44a are reliably suppressed.

[0097] As shown in Figures 1 and 2, the hydraulic excavator 1 is equipped with a canopy 100. In the canopy specification, the effect of this embodiment in suppressing vibration of the driver's seat 44a is obtained by providing a reinforcing member RM to the slewing frame 41. In particular, in the canopy specification, the load on the slewing frame 41 is lighter than in the cabin specification, so the slewing frame 41 vibrates due to engine EG vibrations, and the driver's seat 44a is more prone to vibration. For this reason, in the hydraulic excavator 1 with a canopy specification, the configuration of this embodiment, which provides a reinforcing member RM to the slewing frame 41, is very effective in suppressing vibration of the driver's seat 44a.

[0098] Furthermore, the canopy 100 includes a first support column 101, a second support column 102, a third support column 103, and a roof section 104. In this three-column canopy configuration, the effect of this embodiment, which suppresses vibrations of the driver's seat 44a, is obtained by providing a reinforcing member RM on the slewing frame 41.

[0099] [6. Other components of a hydraulic excavator] Figure 12 is a left side view showing another configuration of the hydraulic excavator 1. As shown in the figure, the hydraulic excavator 1 may also be configured with a cabin 100A instead of a canopy 100 (see Figure 1, etc.). The cabin 100A surrounds the driver's seat 44a. That is, the cabin 100A surrounds the driver's seat 44a in front, behind, to the right, to the left, and above. In the cabin 100A, a door 100D is located to the left front of the driver's seat 44a. The operator can enter and exit the operating section 44 by opening and closing the door 100D.

[0100] Even in a hydraulic excavator 1 with a cabin configuration, the effect of this embodiment in suppressing vibrations of the driver's seat 44a caused by engine EG vibrations can be obtained by providing a reinforcing member RM to the slewing frame 41. In particular, since the cabin 100A is box-shaped and restrains the area around the slewing frame 41, the cabin configuration has a higher vibration suppression effect than the canopy configuration. Therefore, by using the reinforcing member RM in combination with the cabin configuration, the effect of suppressing vibrations of the driver's seat 44a caused by engine EG vibrations is further enhanced.

[0101] [7. Regarding the exhaust tailpipe] As shown in Figure 7, the engine EG is connected to the muffler MU. The muffler MU is then connected to the exhaust tailpipe TP. Therefore, the exhaust gas emitted from the engine EG is silenced by passing through the muffler MU and then discharged to the outside of the hydraulic excavator 1 through the exhaust tailpipe TP. At this time, since the exhaust tailpipe TP has a throttling structure, the exhaust gas is also silenced by passing through the exhaust tailpipe TP. The details of the exhaust tailpipe TP will be explained below.

[0102] Figure 13A is a perspective view showing the external appearance of the exhaust tailpipe TP. Figure 13B is an exploded perspective view of the exhaust tailpipe TP. As shown in these figures, the exhaust tailpipe TP has a first pipe TP1 and a second pipe TP2. The inner diameter of the first pipe TP1 is slightly larger than the maximum outer diameter of the second pipe TP2. As a result, the second pipe TP2 is fitted inside the first pipe TP1. The second pipe TP2 is connected to and fixed to the first pipe TP1 by welding or the like while it is fitted inside the first pipe TP1 (see Figure 13A). The end of the first pipe TP1 opposite to the side connected to the second pipe TP2 is connected to the exhaust outlet portion of the muffler MU (see Figure 7).

[0103] As shown in Figure 13B, the second pipe TP2 has a large-diameter section TP2a, a small-diameter section TP2b, and an intermediate section TP2c. The large-diameter section TP2a is a pipe with a constant outer diameter and inner diameter. The small-diameter section TP2b is also a pipe with a constant outer diameter and inner diameter. However, the large-diameter section TP2a has a larger outer diameter and a larger inner diameter than the small-diameter section TP2b.

[0104] The large-diameter section TP2a and the small-diameter section TP2b are connected via an intermediate section TP2c. The outer and inner diameters of the intermediate section TP2c decrease continuously from the large-diameter section TP2a side towards the small-diameter section TP2b side. In other words, the maximum outer and inner diameters of the intermediate section TP2c are equal to the outer and inner diameters of the large-diameter section TP2a, respectively. Also, the minimum outer and inner diameters of the intermediate section TP2c are equal to the outer and inner diameters of the small-diameter section TP2b, respectively. A thin metal ring RG is fixed to the inside of the large-diameter section TP2a by welding.

[0105] Figure 14A is a perspective view including a cross-section when the connecting portion between the first pipe TP1 and the second pipe TP2 is cut at an arbitrary plane. Figure 14B is a cross-sectional view of the above connecting portion. The inner diameter of the first pipe TP1 is D1 (mm), the inner diameter of the large diameter portion TP2a of the second pipe TP2 is D2 (mm), the inner diameter of the small diameter portion TP2b of the second pipe TP2 is D3 (mm), and the inner diameter (opening diameter) of the ring RG is D4 (mm). D1, D2, D3, and D4 have the following relationships. D1>D2>D3>D4 ···(A) That is, D1 is larger than D2. D2 is larger than D3. D3 is larger than D4.

[0106] The exhaust gas discharged from the muffler MU passes through the inside of the first pipe TP1 and the second pipe TP2 of the exhaust tail pipe TP in sequence and is discharged to the outside. Here, by satisfying the above relational expression (A), when the exhaust gas flows from the first pipe TP1 to the second pipe TP2, the flow path of the exhaust gas is temporarily narrowed from D1 to D4 by the ring RG. After that, the flow path widens to D2, which is the inner diameter of the large-diameter portion TP2a. When the exhaust gas flows from the large-diameter portion TP2a to the small-diameter portion TP2b through the intermediate portion TP2c, the flow path decreases from D2 to D3, and then the exhaust gas is discharged to the outside from the small-diameter portion TP2b.

[0107] Thus, since the flow path of the exhaust gas is narrowed from D1 to D4 and then widens to D2, the exhaust gas expands and is depressurized after passing through the ring RG. Thereby, the exhaust sound of the exhaust gas is silenced.

[0108] For example, if the inner diameter of the pipe can be set to D4, that is, if a pipe with an inner diameter of D4 can be manufactured, an exhaust tail pipe TP having a silencing function can be manufactured without arranging the above ring RG. However, in reality, due to design or manufacturing constraints of the pipe, there is a limit to reducing the diameter of the pipe. That is, it is actually difficult to set the inner diameter of the pipe to less than D3 due to the above constraints.

[0109] In this embodiment, a second pipe TP2 with a minimum inner diameter of D3 within the above constraints is manufactured, and a ring with an inner diameter of D4, which is smaller than D3, is arranged inside the second pipe TP2. Thus, even if the inner diameter of the second pipe TP2 is D3, the flow path of the exhaust gas can be narrowed to D4 (<D3). Thereby, even if there are the above constraints that make it difficult to reduce the diameter, a pipe design that narrows the flow path becomes possible, and thereby silencing of the exhaust gas can be realized. That is, the muffler MU and the exhaust tail pipe TP can be connected to perform silencing of the exhaust gas in two stages.

[0110] [8. Supplement] The engine support parts, such as the left front support part 91 described above, may be made of hollow pipes or solid pipes. However, since hollow pipes generally have low rigidity, it is preferable that the left front support part 91 be made of solid pipes. The solid pipe may be made of a single round bar, or it may be made by inserting a round bar inside a hollow pipe.

[0111] In this embodiment, a three-post canopy 100, which has three support posts, was used as an example for the description, but the number of support posts is not particularly limited. In other words, the number of support posts for the canopy 100 may be two (a two-post canopy), or it may be four or more.

[0112] In this embodiment, an example was described in which the driver's unit 44 and canopy 100 are located on the left side of the upper rotating body 4, and the work implement 3 is located on the right side. However, the relative positions of these components may be reversed left and right. In this case, one side in the left-right direction becomes the "right side," and the other side becomes the "left side."

[0113] The hydraulic excavator 1 may be configured to use both hydraulic equipment such as hydraulic actuators (e.g., hydraulic motors, hydraulic cylinders) and electrically driven actuators. Examples of electrically driven actuators include electric travel motors, electric cylinders, and electric slewing motors.

[0114] In this embodiment, a hydraulic excavator 1 was used as an example of the work machine, but the work machine is not limited to a hydraulic excavator 1 and may be construction machinery such as a mobile crane. Furthermore, the work machine may be agricultural machinery such as a combine harvester or tractor.

[0115] [9. Addendum] The work machine (hydraulic excavator 1) described in this embodiment can be described as follows:

[0116] The work machines mentioned in Appendix (1) are: A base plate that positions the engine upwards, A work machine comprising a seat support base that covers the engine from above and supports the driver's seat, A vertical plate extending from the base plate toward one side of the engine and extending from rear toward front, The device comprises a reinforcing member erected on the base plate, connected to the vertical plate, and extending from the vertical plate to one side.

[0117] The work machines in Appendix (2) are the work machines described in Appendix (1), The base plate further comprises a support base support portion erected on one side of the vertical plate and supporting the seat support base, The reinforcing member is positioned between the vertical plate and the support base support portion when viewed from the rear.

[0118] The work machines in Appendix (3) are the work machines described in Appendix (2), The reinforcing member extends from the vertical plate toward the support portion of the support base.

[0119] The work machines in Appendix (4) are the work machines described in Appendix (3), The base plate further comprises an engine support section arranged alongside the vertical plate to support the engine, The reinforcing member is positioned between the engine support and the support base support.

[0120] The work machines in Appendix (5) are the work machines described in Appendix (4), The engine support portion is positioned on the other side relative to the vertical plate.

[0121] The work machines in Appendix (6) are the work machines described in Appendix (4) or (5), The aforementioned vertical plate is positioned away from the engine support portion.

[0122] The work machines in Appendix (7) are the work machines described in Appendix (4) or (5), The vertical plate is arranged in connection with the engine support section.

[0123] The work machine in Appendix (8) is the work machine described in any of Appendix (2) to (7), The reinforcing member is positioned separately from the support portion of the support base.

[0124] The work machine in Appendix (9) is the work machine described in any of Appendix (2) to (7), The reinforcing member is arranged in connection with the support portion of the support base.

[0125] The work machine in Appendix (10) is the work machine described in any of Appendix (2) to (9), The support frame is further provided, which spans the support portion of the support base and the vertical plate, and supports the seat support base at a position rearward from the driver's seat. The reinforcing member is positioned in front of the support frame.

[0126] The work machine in Appendix (11) is the work machine described in any of Appendix (1) to (10), The reinforcing member has a first end connected to the vertical plate and a second end on the opposite side of the vertical plate from the first end, The height of the second end is lower than that of the first end.

[0127] The work machine in Appendix (12) is the work machine described in any of Appendix (1) to (11), The reinforcing member is positioned in front of the rear end of the engine in a plan view.

[0128] The work machine in Appendix (13) is the work machine described in any of Appendix (1) to (12), The system further includes a canopy that covers the area above the driver's seat.

[0129] The work machine in Appendix (14) is the work machine described in Appendix (13), The aforementioned canopy is, A first support column is erected on one side of the seat support base behind the driver's seat, In the aforementioned seat support base, a second support column is erected on the other side relative to the first support column, A third support column is positioned in front of the second support column, It includes a roof section supported by the first support column, the second support column, and the third support column, which covers the area above the driver's seat.

[0130] The work machine in Appendix (15) is the work machine described in any of Appendix (1) to (12), The system further includes a cabin that surrounds the driver's seat.

[0131] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and it can be expanded or modified without departing from the spirit of the invention. [Industrial applicability]

[0132] This invention can be used, for example, in work machinery such as construction machinery and agricultural machinery. [Explanation of symbols]

[0133] 1. Hydraulic excavator (working machine) 41. Swivel frame (base frame) 43S Seat support stand 44a Driver's seat 81 Left support frame (support frame) 91 Left front support part (support stand support part) 92 Left vertical board (vertical board) 100 Canopy 100A Cabin 101 1st pillar 102 Second pillar 103 3rd pillar 104 Roof section EG engine ES1 First engine support section (engine support section) RM reinforcing member RM1 1st end RM2, second end

Claims

1. A base plate that positions the engine upwards, A work machine comprising a seat support base that covers the engine from above and supports the driver's seat, A vertical plate extending from the base plate toward one side of the engine and extending from rear toward front, A work machine comprising a reinforcing member erected on the base plate, connected to the vertical plate, and extending from the vertical plate to one side.

2. The base plate further comprises a support base support portion erected on one side of the vertical plate and supporting the seat support base, The work machine according to claim 1, wherein the reinforcing member is positioned between the vertical plate and the support base support portion when viewed from the rear.

3. The work machine according to claim 2, wherein the reinforcing member extends from the vertical plate toward the support portion of the support base.

4. The base plate further comprises an engine support section arranged alongside the vertical plate to support the engine, The work machine according to claim 3, wherein the reinforcing member is disposed between the engine support portion and the support base support portion.

5. The working machine according to claim 4, wherein the engine support portion is arranged on the other side relative to the vertical plate.

6. The work machine according to claim 4, wherein the vertical plate is arranged separately from the engine support portion.

7. The work machine according to claim 4, wherein the vertical plate is arranged in connection with the engine support portion.

8. The work machine according to claim 2, wherein the reinforcing member is arranged separately from the support base support portion.

9. The work machine according to claim 2, wherein the reinforcing member is arranged in connection with the support base support portion.

10. The support frame is further provided, which spans the support portion of the support base and the vertical plate, and supports the seat support base at a position rearward from the driver's seat. The work machine according to claim 2, wherein the reinforcing member is positioned in front of the support frame.

11. The reinforcing member has a first end connected to the vertical plate and a second end on the opposite side of the vertical plate from the first end, The working machine according to claim 1, wherein the height of the second end is lower than that of the first end.

12. The work machine according to claim 1, wherein the reinforcing member is positioned in front of the rear end of the engine in a plan view.

13. The work machine according to any one of claims 1 to 12, further comprising a canopy covering the area above the driver's seat.

14. The aforementioned canopy is, A first support column is erected on one side of the seat support base behind the driver's seat, In the aforementioned seat support base, a second support column is erected on the other side of the first support column, A third support column is positioned in front of the second support column, The work machine according to claim 13, further comprising a roof portion supported by the first support column, the second support column, and the third support column, and covering the area above the driver's seat.

15. The work machine according to any one of claims 1 to 12, further comprising a cabin that covers the area around the driver's seat.

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