Construction machinery

Abstract

To enable early visual detection of hydraulic fluid leaks from the pressure regulating valve, damage to the pressure regulating valve and surrounding equipment can be minimized. [Solution] The pressure regulating valve 30, which adjusts the pressure of the hydraulic fluid, is positioned on the rear surface 13E of the boom 13 facing the driver's seat 8 when the boom 13 is in its highest position, on the roof 10E side of the cab 10, above the floor 6 and below the roof 10E. Therefore, the pressure regulating valve 30 can be positioned within the field of view of the operator seated in the driver's seat 8.

Description

Technical Field

[0005]

[0001] The present disclosure relates to construction machinery such as hydraulic excavators, and particularly to construction machinery provided with a pressure regulating valve for adjusting the pressure of hydraulic oil supplied to a hydraulic cylinder in a working device.

Background Art

[0002] A hydraulic excavator, which is representative of construction machinery, includes a lower traveling body and an upper revolving body that constitute the vehicle body, and a working device is provided on the front side of the upper revolving body. The working device of the hydraulic excavator includes a boom whose first end in the longitudinal direction is rotatably provided on the revolving frame of the upper revolving body, an arm whose first end in the longitudinal direction is rotatably provided at the second end in the longitudinal direction of the boom, a working tool rotatably provided at the second end in the longitudinal direction of the arm, and a plurality of hydraulic cylinders for individually operating members including the boom, the arm, and the working tool. Examples of the working tool include a bucket, a grapple, a breaker, etc.

[0003] The hydraulic cylinders include a boom cylinder for rotating the boom, an arm cylinder for rotating the arm, and a working tool cylinder for rotating the working tool. When performing special work other than excavation work with the working device, another working tool is attached instead of the bucket, and a hydraulic cylinder for this working tool is additionally attached.

[0004] Here, in the working device, a pressure regulating valve for adjusting the pressure of hydraulic oil supplied to and discharged from at least one of the plurality of hydraulic cylinders is provided (Patent Document 1). The pressure regulating valve in this Patent Document 1 is attached to the boom cylinder located below or in front of the boom. The pressure regulating valve prevents the boom from lowering due to leakage of hydraulic oil by adjusting the pressure of the hydraulic oil.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] The pressure regulating valve described in Patent Document 1 is attached to a boom cylinder located on the underside or front side of the boom. Because the boom obstructs the view of the pressure regulating valve from the operator's seat, there is a problem in that hydraulic fluid leaks from the pressure regulating valve to which the hydraulic hose is connected, but this cannot be detected early.

[0007] The object of the present invention is to provide a construction machine that allows for early visual detection of hydraulic fluid leakage from a pressure regulating valve. [Means for solving the problem]

[0008] The present invention relates to a construction machine equipped with a working device on the front side of a vehicle body, wherein the vehicle body comprises a vehicle frame with a floor on the front side, a driver's seat provided above the floor, and a roof covering the area above the driver's seat, and the working device comprises a driven member including a boom with one end in the longitudinal direction rotatably attached to the vehicle frame, a hydraulic cylinder for operating the driven member, and a pressure regulating valve for adjusting the pressure of the hydraulic fluid supplied to and discharged from the hydraulic cylinder, wherein the pressure regulating valve is positioned on the rear surface of the boom facing the driver's seat when the boom is in its highest raised position on the roof side, above the floor and below the roof. [Effects of the Invention]

[0009] According to the present invention, operators can visually detect hydraulic fluid leaks from the pressure regulating valve at an early stage. This minimizes damage to the pressure regulating valve and surrounding equipment, thereby reducing the cost and time required for repair work. [Brief explanation of the drawing]

[0010] [Figure 1] This is a left side view showing a hydraulic excavator according to an embodiment of the present invention. [Figure 2] The cab, working device, and control valve unit are shown in a cross-sectional view from arrow II-II in Figure 1. [Figure 3] This is a perspective view showing a work device equipped with a pressure regulating valve. [Figure 4] This is a perspective view showing the boom with the control valve unit attached. [Figure 5] This is a magnified perspective view showing the area around the control valve unit. [Figure 6] The boom, bracket, and pressure regulating valve are shown in a cross-sectional view from arrow VI-VI in Figure 4. [Figure 7] This is a perspective view showing the boom and control valve unit in a disassembled state. [Figure 8] This is a perspective view showing the control valve unit. [Figure 9] This is a perspective view showing the bracket and pressure regulating valve. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the construction machinery according to the present invention will be described in detail with reference to Figures 1 to 9, using the application of a hydraulic excavator as an example. In this embodiment, the direction of travel of the hydraulic excavator will be described as the front-rear direction, and the direction perpendicular to the direction of travel will be described as the left-right direction. Furthermore, for the swivelable upper rotating body, the direction of the operator's line of sight while seated in the driver's seat will be described as the front.

[0012] In Figure 1, the hydraulic excavator 1 is composed of a self-propelled crawler-type lower vehicle 2, an upper slewing body 3 that is rotatably mounted on the lower vehicle 2, and a work device 11, described later, provided on the front side of the upper slewing body 3. The lower vehicle 2 and the upper slewing body 3 constitute the body of the hydraulic excavator 1. The upper slewing body 3 is composed of a slewing frame 4, floor 6, driver's seat 8, and cab 10, described later.

[0013] The slewing frame 4 is formed as a support structure having a thickness in the vertical direction and is pivotally mounted on the lower traveling body 2. A support bracket 4A is provided protruding forward on the front portion of the slewing frame 4. The swing post 12 of the working device 11 is supported by the support bracket 4A so as to be swingable in the left-right direction. Further, the support bracket 4A is disposed on the right side of the driver's seat 8 described later.

[0014] A counterweight 5 for balancing the weight with the working device 11 is provided at the rear portion of the slewing frame 4. On the slewing frame 4, a prime mover such as an engine or an electric motor, a hydraulic pump, etc. (all not shown) are mounted in front of the counterweight 5. Here, on the slewing frame 4, in front of the counterweight 5, the range from the intermediate portion in the left-right direction in the vehicle width direction of the upper slewing body 3 to the left side is the operator's boarding space.

[0015] The floor 6 is a support plate for the operator to board and is provided in the boarding space on the slewing frame 4. The floor 6 is formed as a flat surface extending in the front-rear direction and the left-right direction. The floor 6 is disposed at the same height position as the upper surface portion of the slewing frame 4. Further, a driver's seat pedestal 7 rising in a step shape is formed at the rear side of the floor 6. The driver's seat pedestal 7 serves as a mounting base for the driver's seat 8.

[0016] The driver's seat 8 is provided above the floor 6 and is located on the left side in the vehicle width direction. The driver's seat 8 is for the operator boarding on the floor 6 to sit. The driver's seat 8 is composed of a seat surface 8A mounted on the driver's seat pedestal 7 and a backrest 8B extending upward from the rear portion of the seat surface 8A.

[0017] Working operation levers 9 for operating the upper slewing body 3 and the working device 11 are provided on both the left and right sides of the driver's seat 8. Further, a traveling lever and pedal (not shown) for operating the lower traveling body 2 are provided in front of the driver's seat 8.

[0018] The cab 10 is disposed on the left front side of the swivel frame 4 so as to cover the floor 6. The cab 10 forms a box-shaped building that covers the entire circumference and above of the driver's seat 8. As shown in FIGS. 1 and 2, the cab 10 includes a front portion 10A, a rear portion 10B, a left side portion 10C, a right side portion 10D, and a roof 10E.

[0019] Further, a front window 10F is provided in the front portion 10A. This front window 10F provides a wide forward view for the operator sitting in the driver's seat 8 and is formed over substantially the entire surface of the front portion 10A. Here, the working device 11 is located on the right side of the field of view through the front window 10F. Thereby, the operator sitting in the driver's seat 8 can visually observe an adjustment valve unit 22, which will be described later, attached to the boom 13 through the front window 10F.

[0020] The roof 10E forms an upper surface portion that covers the upper part of the driver's seat 8. The roof 10E is arranged at a height position where a standard extended operator can board without difficulty, specifically, at a position equal to or slightly lower than the bent portion 13C of the raised boom 13. Further, a door 10G is provided on the left side portion 10C so as to be openable and closable.

[0021] The working device 11 is rotatably supported by a support bracket 4A of the swivel frame 4. The working device 11 includes a swing post 12 provided on the support bracket 4A so as to be swingable in the left-right direction, a boom 13 having a longitudinal first end 13A (one end) rotatably provided on the swing post 12, an arm 14 having a longitudinal first end 14A rotatably provided on the longitudinal second end 13B of the boom 13, and a bucket 15 as a working tool rotatably provided on the longitudinal second end 14B of the arm 14. The boom 13, the arm 14, and the bucket 15 constitute driven members. Further, the working device 11 includes boom cylinders 16, arm cylinders 17, and bucket cylinders 18 as hydraulic cylinders.

[0022] The boom 13 is rotatably mounted on the slewing frame 4 via a swing post 12. As a result, the boom 13 is positioned in front of the front window 10F of the cab 10. The boom 13 has a bent section 13C in the middle of its longitudinal direction, which is bent in an L-shape. The boom 13 is at its highest position when it is raised towards the roof 10E of the cab 10. Specifically, the highest position of the boom 13 is the state shown in Figure 1, where the boom 13 is raised and the bent section 13C is closest to the front part 10A of the cab 10. In this highest position of the boom 13, the boom cylinder 16, which will be described later, is located on the front side 13D, which is located at the front. On the other hand, in the highest position of the boom 13, the hydraulic pipeline 19, additional pipeline 20, and adjustment valve unit 22, which will be described later, are located on the rear side 13E, which is located opposite the driver's seat 8.

[0023] The boom cylinder 16 is located on the front 13D side of the boom 13 and is installed between the swing post 12 and the boom 13. The boom cylinder 16 rotates the boom 13 relative to the swing post 12.

[0024] The arm cylinder 17 rotates the arm 14 relative to the boom 13 and is located between the boom 13 and the arm 14. The bucket cylinder 18, which acts as a work tool cylinder, rotates the bucket 15 relative to the arm 14 and is located between the arm 14 and the bucket 15.

[0025] Here, the bucket 15 of the work device 11 is shown as an example of a work tool and can be replaced with other work tools such as a grapple or breaker. Cutters, grapples, breakers, etc., perform other actions such as gripping, rotating, and striking, in addition to rotation relative to the arm 14. Therefore, the work device 11 needs a supply and discharge route for pressurized oil used for actions other than rotation, assuming that other work tools such as cutters, grapples, and breakers are attached.

[0026] Furthermore, other work tools use different pressures for the pressurized oil used in operations other than rotation. For example, grapples, drum cutters, and cutters require high pressure. On the other hand, breakers and tilt buckets do not require high pressure and can be operated at low pressure.

[0027] Thus, when other work tools are attached in place of the bucket 15, it is necessary to adjust the supply pressure so that pressurized oil at a pressure suitable for the attached work tool is supplied. For this reason, the work device 11 is equipped with a pressure regulating valve 30, which will be described later. In addition to work tools, the pressure regulating valve can also be used to adjust the pressure of the pressurized oil supplied to hydraulic cylinders such as the boom cylinder, arm cylinder, and bucket cylinder, in cases where their settings are changed or other modifications are made.

[0028] The multiple hydraulic lines 19 consist of pipes and hoses for supplying and discharging pressurized oil to the arm cylinder 17 and bucket cylinder 18. The multiple hydraulic lines 19 are arranged along the rear surface 13E of the boom 13. As a result, the multiple hydraulic lines 19 pass between the rear surface 13E and the bracket 23, which will be described later.

[0029] The multiple additional pipelines 20 form other hydraulic pipelines, and for example, two are provided, one for the supply side and one for the return side. The two additional pipelines 20 are pipes and hoses for supplying and discharging pressurized oil to and from work tools when other work tools are attached in place of the bucket 15. The return pipeline 21 is a pipe and hose for returning the hydraulic oil discharged from the pressure regulating valve 30 to the hydraulic oil tank (not shown). The two additional pipelines 20 and the return pipeline 21 are located on the rear side 13E of the boom 13 and extend in the longitudinal direction of the boom 13.

[0030] Furthermore, as shown in Figure 1, the ends of the two additional conduits 20 are flexible hoses, and their ends are connected to a connector 20A attached to the left side of the arm 14. Hoses (not shown) for supplying and discharging pressurized oil to operate other work tools are connected to the two connectors 20A.

[0031] Next, the configuration of the regulating valve unit 22 equipped with the pressure regulating valve 30 of this embodiment will be described.

[0032] The regulating valve unit 22 comprises a bracket 23, a pressure regulating valve 30, and a valve cover 31, which will be described later. As shown in Figures 1 to 5, the regulating valve unit 22 is located on the rear surface 13E side of the boom 13. In this configuration, the regulating valve unit 22, including the pressure regulating valve 30, is positioned on the rear surface 13E of the boom 13 facing the driver's seat 8, in the highest position of the boom 13 (the position shown in Figure 1) when the boom 13 is raised towards the roof 10E side of the cab 10, above the floor 6 and below the roof 10E. Also, as shown in Figure 2, the regulating valve unit 22, including the pressure regulating valve 30, is positioned in the vehicle width direction to overlap with the front window 10F of the cab 10.

[0033] Bracket 23 is used to fix the pressure regulating valve 30 and the like to the rear surface 13E of the boom 13. Bracket 23 is provided on the rear surface 13E of the boom 13 so as to straddle the hydraulic pipeline 19 that extends along the longitudinal direction of the boom 13.

[0034] As shown in Figures 6 and 7, the bracket 23 comprises a pair of screw seats 24 that protrude from both the left and right sides of the rear surface 13E of the boom 13 and have screw holes 24A formed therein with the left-right axis; a valve support plate 25 that is made of a plate body that extends parallel to and facing the rear surface 13E of the boom 13 and has a mounting plate portion 25A at its left end that overlaps with the left screw seat 24; and a connecting plate 26 that is formed as an L-shaped plate body having a vertical plate portion 26A that overlaps with the right screw seat 24 and a horizontal plate portion 26B that overlaps with the right portion of the valve support plate 25.

[0035] The mounting plate portion 25A of the valve support plate 25 has a bolt insertion hole 25B that penetrates in the left-right direction and communicates with the screw hole 24A of the left screw seat 24. In addition, a bolt insertion hole 25C is provided on the right side of the valve support plate 25, penetrating in the thickness direction.

[0036] The connecting plate 26 has a bolt insertion hole 26C in the vertical plate portion 26A that overlaps with the screw seat 24 on the right side, which communicates with the screw hole 24A, and a bolt insertion hole 26D in the horizontal plate portion 26B that overlaps with the valve support plate 25, which communicates with the bolt insertion hole 25C. The connecting plate 26 can also be omitted by extending and bending the right side portion of the valve support plate.

[0037] An example of the procedure for attaching the bracket 23 configured in this way to the boom 13 will be described below. The valve support plate 25 is positioned so that the mounting plate portion 25A is in contact with the left side surface of the left screw seat 24, with the bolt insertion hole 25B communicating with the screw hole 24A. In this state, the bolt 27 is inserted through the bolt insertion hole 25C and screwed into the screw hole 24A.

[0038] Furthermore, the connecting plate 26 is positioned so that the vertical plate portion 26A is in contact with the right side surface of the right-side screw seat 24, with the bolt insertion hole 26C communicating with the screw hole 24A. At this time, the horizontal plate portion 26B of the connecting plate 26 is placed on top of the right-side portion of the valve support plate 25, with the bolt insertion hole 26C communicating with the bolt insertion hole 25C. In this state, the bolt 27 is inserted through the bolt insertion hole 26C and screwed into the screw hole 24A, and the bolt 28 is inserted through the bolt insertion holes 26C and 25C and screwed into the nut 29.

[0039] As a result, the bracket 23 can be attached to the rear surface 13E of the boom 13. In this case, the bracket 23 can position the pressure regulating valve 30, described later, on the rear surface 13E side of the boom 13, while creating a space between the valve support plate 25 and the rear surface 13E of the boom 13. In other words, if the rear surface 13E of the boom 13 is considered the first floor, the bracket 23 can position the pressure regulating valve 30 on the second floor portion that overlaps with this first floor. In this structure, where the pressure regulating valve 30 is positioned away from the rear surface 13E of the boom 13, it is not obstructed by the hydraulic pipeline 19 routed along the rear surface 13E of the boom 13, so the mounting position of the pressure regulating valve 30 can be freely set in the longitudinal direction of the boom 13.

[0040] As shown in Figures 3 and 5, the pressure regulating valve 30 is attached to the rear surface 13E of the boom 13 via the bracket 23. The pressure regulating valve 30 is also attached to the bracket 23 so as to overlap with the hydraulic pipeline 19, with the bracket 23 in between. Furthermore, the pressure regulating valve 30 is positioned in the longitudinal direction of the boom 13, between the first end 13A and the bent section 13C, closer to the first end 13A.

[0041] More specifically, the pressure regulating valve 30 is located on the rear surface 13E of the boom 13, which is positioned at the rear of the boom 13 when it is raised to the roof 10E side of the cab 10 (as shown in Figure 1), above the floor 6 and below the roof 10E. More specifically, the pressure regulating valve 30 is located at the same height as the driver's seat 8 (between the bottom surface of the seat cushion 8A and the top end of the backrest 8B) when the boom 13 is raised to the rear. Furthermore, the pressure regulating valve 30 is located slightly to the left of the rear surface 13E of the boom 13 on the driver's seat 8 side. As a result, the pressure regulating valve 30 is located in a position that overlaps with the front window 10F in the vehicle width direction.

[0042] The pressure regulating valve 30 is located in the middle of the two additional pipelines 20. The additional pipelines 20 are connected to the top of the pressure regulating valve 30, and the return pipeline 21 is connected to the right side of the pressure regulating valve 30. The pressure regulating valve 30 adjusts the pressure of the hydraulic oil supplied to other work tools connected to the connection part 20A of the additional pipeline 20 so that it reaches an appropriate value, and a portion of the hydraulic oil is discharged to the hydraulic oil tank via the return pipeline 21.

[0043] The pressure regulating valve 30 is configured as an electromagnetic proportional relief valve comprising a valve body 30A having an oil passage, a valve section, etc. within a block, and a solenoid 30B attached to the valve body 30A to operate the valve section of the valve body 30A. In the highest position of the boom 13, the pressure regulating valve 30 is bolted to the side of the valve support plate 25 opposite to the rear surface 13E such that the solenoid 30B is positioned on the lower side.

[0044] The lower end of the solenoid 30B is provided with an air outlet 30C that can be opened and closed to discharge air accumulated inside the solenoid 30B. However, when, for example, a hydraulic hose is replaced, air may enter the hydraulic fluid supply and discharge path. If air contained in the hydraulic fluid flowing inside the pressure regulating valve 30 enters the solenoid 30B, the valve part of the valve body 30A will not be able to operate properly, and proper pressure regulation will not be possible. Therefore, if air enters the solenoid 30B, maintenance is required to discharge the air inside the solenoid 30B to the outside.

[0045] To discharge the air inside the solenoid 30B to the outside, the air outlet 30C is opened, and the pressure of the hydraulic fluid flowing through the pressure regulating valve 30 is increased, thereby discharging the air along with the hydraulic fluid flowing through the pressure regulating valve 30. If the air outlet 30C is not closed after discharging the air from the solenoid 30B, the hydraulic fluid will leak out of the air outlet 30C when the pressure of the hydraulic fluid flowing through the pressure regulating valve 30 increases due to the operation of the work device 11.

[0046] Here, the pressure regulating valve 30 is positioned at the same height as the driver's seat 8 when the boom 13 is in its highest position, and is located slightly to the left of the rear surface 13E of the boom 13. Therefore, as shown in Figure 2, the pressure regulating valve 30 can be positioned to the right of the front window 10F and is within the field of view of the operator seated in the driver's seat 8. Furthermore, the pressure regulating valve 30, positioned slightly to the left at the same height as the driver's seat 8, can be easily reached by workers on the ground.

[0047] The valve cover 31 is detachably attached to the bracket 23 so as to cover the pressure regulating valve 30. As shown in Figures 7 and 8, the valve cover 31 has a box shape that extends in the longitudinal direction of the boom 13 and is attached to the bracket 23 using bolts 32. The valve cover 31 can protect the pressure regulating valve 30 from flying stones and soil.

[0048] The hydraulic excavator 1 according to this embodiment has the configuration described above, and its operation will now be described. The operator, seated in the driver's seat 8 and mounted in the cab 10, can drive the hydraulic excavator 1 to the work site by operating the travel levers and pedals. At the work site, the operator can rotate the upper slewing body 3 and operate the work device 11 to perform excavation work such as soil digging by operating the work operation lever 9.

[0049] Here, since high-pressure hydraulic fluid (pressurized oil) flows through the multiple hydraulic lines 19 and the additional line 20, it is possible that the hydraulic fluid may leak due to deterioration over time or damage from contact. For example, the connection between the additional line 20 and the pressure regulating valve 30 is at high risk of hydraulic fluid leakage. In addition, there is a high risk of hydraulic fluid leakage from the air outlet 30C, which is opened and closed for maintenance of the pressure regulating valve 30. In particular, the risk of hydraulic fluid leakage is high during operation of the hydraulic excavator 1, when the load on the work device 11 increases and the pressure of the hydraulic fluid tends to rise. On the other hand, if a hydraulic fluid leak can be detected early, the damage to the surroundings can be kept to a minimum. However, in a configuration such as Patent Document 1, where the pressure regulating valve is attached to the boom cylinder located on the front side of the boom, it is not visible to the operator inside the cab 10, so it is impossible to notice a hydraulic fluid leak.

[0050] However, according to this embodiment, the pressure regulating valve 30 for adjusting the hydraulic fluid pressure is positioned on the rear surface 13E of the boom 13 facing the driver's seat 8 when the boom 13 is in its highest position, on the roof 10E side of the cab 10, above the floor 6 and below the roof 10E.

[0051] Therefore, the pressure regulating valve 30 can be positioned within the field of view of the operator seated in the driver's seat 8. This allows for early visual detection of any hydraulic fluid leak from the pressure regulating valve 30 during operation of the hydraulic excavator 1, for example, if the air outlet 30C is left open during maintenance to discharge air from the solenoid 30B. As a result, damage caused by hydraulic fluid leaks can be minimized. Furthermore, since the pressure regulating valve 30 can be positioned at a low height that is easily accessible from the ground, work efficiency during maintenance and other operations can be improved.

[0052] Furthermore, the driver's seat 8 is located on the left side of the superstructure 3, and the working device 11 is located on the right side of the driver's seat 8. In addition, the pressure regulating valve 30 is located on the left side of the rear surface 13E of the boom 13. This allows the pressure regulating valve 30 to be located close to the left side where work is performed, thereby improving workability when performing maintenance, etc.

[0053] Furthermore, the cab 10 is a box-shaped building that covers the entire circumference and above the driver's seat 8, and has a front section 10A, a rear section 10B, a left side section 10C, a right side section 10D, and a roof 10E. The front section 10A is provided with a front window 10F, the boom 13 is positioned in front of the front window 10F, and the pressure regulating valve 30 (regulating valve unit 22) is positioned in the vehicle width direction to overlap with the front window 10F. As a result, the operator can see the pressure regulating valve 30 (regulating valve unit 22) in the field of view visible from the front window 10F by looking forward in a normal working posture while seated in the driver's seat 8, and can easily see any oil leaks.

[0054] Furthermore, the rear surface 13E of the boom 13 is provided with a hydraulic pipeline 19 extending along the longitudinal direction of the boom 13, and a bracket 23 straddling the hydraulic pipeline 19. The pressure regulating valve 30 is attached to the bracket 23 so as to overlap with the hydraulic pipeline 19, with the bracket 23 in between. Therefore, the hydraulic pipeline 19 can be placed on the rear surface 13E of the boom 13, which is the first floor, and the pressure regulating valve 30 can be placed on the bracket 23, which is the second floor. This avoids the need to avoid multiple hydraulic pipelines 19, so the pressure regulating valve 30 can be placed at any position along the longitudinal direction of the boom 13. As a result, the pressure regulating valve 30 can be placed above the floor 6 and below the roof 10E.

[0055] Furthermore, the pressure regulating valve 30 is positioned at the same height as the operator's seat 8 when the boom 13 is in its highest position. This allows the pressure regulating valve 30 to be positioned at the eye level of the operator sitting in the operator's seat 8, making it easy to visually check for hydraulic fluid leaks.

[0056] In this embodiment, a hydraulic excavator 1 equipped with a cab 10 is used as an example. However, the present invention is not limited to this and can also be applied to a hydraulic excavator equipped with a canopy consisting of a roof. [Explanation of symbols]

[0057] 1. Hydraulic excavator (construction machinery) 2. Lower running body (vehicle body) 3. Upper rotating body (vehicle body) 4. Swivel frame (vehicle frame) 6 floors 8. Driver's seat 10 Cab 10A front part 10B Rear part 10C Left side 10D Right side 10E Roof 10F front window 11 Working equipment 13. Boom (Driven Member) 13A 1st end (one end) 13E Rear 14. Arm (driven member) 15. Bucket (working tool, driven component) 16. Boom Cylinder (Hydraulic Cylinder) 17. Arm Cylinder (Hydraulic Cylinder) 18. Bucket Cylinder (Tool Cylinder, Hydraulic Cylinder) 19 Hydraulic pipeline 20 Additional pipelines (hydraulic pipelines) 23 brackets 30 Pressure regulating valve

Claims

1. A construction machine equipped with a work device on the front of the vehicle body, The aforementioned vehicle body is A vehicle frame with a floor at the front, A driver's seat is provided on the upper part of the aforementioned floor, The roof covering the area above the driver's seat, Equipped with, The aforementioned work apparatus is A driven member including a boom, one end of which is rotatably mounted on the vehicle frame in the longitudinal direction, A hydraulic cylinder for operating the driven member, A pressure regulating valve for adjusting the pressure of the hydraulic fluid supplied to and discharged from the hydraulic cylinder, In a construction machine equipped with, The construction machine is characterized in that the pressure regulating valve is positioned on the rear surface of the boom facing the driver's seat, above the floor and below the roof, when the boom is in its highest position, which is raised towards the roof.

2. In the construction machine described in claim 1, The driver's seat is located on the left side of the vehicle body in the width direction. The aforementioned work device is positioned to the right of the driver's seat in the vehicle width direction. The construction machine is characterized in that the pressure regulating valve is located on the left side of the rear surface of the boom.

3. In the construction machine described in claim 2, The cab is a box-shaped building having a front section, rear section, left section, right section, and the roof, which covers the entire circumference and above the driver's seat. The aforementioned front section is provided with a front window. The boom is positioned in front of the front window. The construction machine is characterized in that the pressure regulating valve is positioned in the vehicle width direction so as to overlap with the front window.

4. In the construction machine described in claim 1, The rear surface of the boom is provided with a hydraulic pipeline extending along the longitudinal direction of the boom and a bracket straddling the hydraulic pipeline. The construction machine is characterized in that the pressure regulating valve is mounted on the bracket so as to overlap with the hydraulic pipeline, with the bracket in between.

5. In the construction machine described in claim 1, The construction machine is characterized in that the pressure regulating valve is positioned at the same height as the driver's seat when the boom is in its highest raised position.

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