Construction machinery

Abstract

To assist an opening / closing work of a hood and improve the maintainability of equipment arranged in an engine room inside the hood with a simple configuration.SOLUTION: An excavation work machine 1 equipped with an engine room 12 arranged at a rear of a revolving frame 7, a hood 9 covering the engine room 12, and a driver's seat 10 arranged above the hood 9 comprises a hinge mechanism 80 that has a body frame side connection part and a hood side connection part and rotatably connects the hood 9 to the revolving frame 7, and biasing force applying means that is disposed between the body frame side connection part and the hood side connection part and applies an upward biasing force to the hood 9.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a construction machine equipped with a bonnet that covers an engine room in which an engine is located. [Background technology]

[0002] In the past, construction machinery such as excavators has had an upper rotating body rotatably mounted on a crawler-type lower traveling body, an engine located on the rear side of the rotating frame of the upper rotating body, and the engine covered by a bonnet. In such construction machinery, the inside of the bonnet serves as an engine room where the engine and other equipment and a fuel tank are located, and the bonnet is configured to be openable and closable to facilitate maintenance of the engine and other components.

[0003] Patent Document 1 discloses a construction machine known as a mini excavator, which has a driver's seat located on the hood, in which a hinge is provided on the front end side of the hood and the hood is opened and closed by rotating in the front-to-rear direction around the hinge axis. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-71005 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the configuration disclosed in Patent Document 1, the hood is simply connected to the members that make up the rotating frame via a hinge. Therefore, when opening the hood for maintenance or inspection, the maintenance technician must lift the rear end of the hood by himself. Furthermore, when closing the hood, the maintenance technician must support the weight of the hood by himself. In particular, if the driver's seat is located on the hood, the weight of the driver's seat is also added to the hood, increasing the workload of the maintenance technician when opening and closing the hood.

[0006] Furthermore, in small construction machinery such as mini excavators, the engine and other components are located in the limited space covered by the hood under the driver's seat, making it difficult to secure space within the hood for installing gas springs, torsion bars, and other components that assist in opening and closing the hood.

[0007] The present invention has been made in consideration of the above-mentioned problems, and relates to a hood opening and closing structure for a construction machine in which the driver's seat is located above the hood, and has as its object to provide a construction machine that has a simple configuration that assists in opening and closing the hood and improves the ease of maintenance of the equipment located in the engine room inside the hood. [Means for solving the problem]

[0008] The construction machine of the present invention is a construction machine comprising an engine room arranged at the rear of a body frame, a bonnet covering the engine room, and a driver's seat arranged above the bonnet, and is characterized in that it is equipped with a hinge mechanism having the body frame side connecting portion and the bonnet side connecting portion, which connects the bonnet to the body frame in a freely rotatable manner, and a biasing force applying means which is arranged between the body frame side connecting portion and the bonnet side connecting portion and applies an upward biasing force to the bonnet.

[0009] A construction machine according to another aspect of the present invention is characterized in that the biasing force imparting means is supported on a support shaft that is provided coaxially with the hinge shaft of the hinge mechanism.

[0010] A construction machine according to another aspect of the present invention is characterized in that the hinge shafts are provided in pairs spaced apart in the left-right direction of the machine body, and the support shaft is arranged between the pair of left and right hinge shafts.

[0011] A construction machine according to another aspect of the present invention is characterized in that the biasing force applying means is a torsion coil spring.

[0012] A construction machine according to another aspect of the present invention is characterized in that the torsion coil spring has two coil portions wound with wire, and the two coil portions are extrapolated onto the support shaft provided at the bonnet side connecting portion.

[0013] A construction machine according to another aspect of the present invention is characterized in that the torsion coil spring has an intermediate arm portion provided on the widthwise inner side of the two coil portions, connecting the two coil portions, which abuts against a machine frame side receiving portion provided on the machine frame side connecting portion, and each of the arms extending from the widthwise outer sides of the two coil portions abuts against a bonnet side receiving portion provided on the bonnet side connecting portion.

[0014] A construction machine according to another aspect of the present invention is characterized in that the torsion coil spring has a coil portion wound with wire, and the coil portion is extrapolated onto the support shaft provided on the body frame side connecting portion.

[0015] A construction machine according to another aspect of the present invention is characterized in that the torsion coil spring has an arm extending from one end of the coil portion that abuts against a machine frame side receiving portion provided on the machine frame side connecting portion, and an arm extending from the other end of the coil portion that abuts against a bonnet side receiving portion provided on the bonnet side connecting portion.

[0016] A construction machine according to another aspect of the present invention is characterized in that the hinge mechanism and the biasing force imparting means are disposed behind the engine room. [Effects of the Invention]

[0017] According to the present invention, the hood opening and closing structure of a construction machine in which the driver's seat is located on the hood has a simple configuration that assists the opening and closing of the hood and improves the maintainability of equipment located in the engine room inside the hood. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a left side view of an excavation machine according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view of an upper revolving body according to a first embodiment of the present invention. [Figure 3] 1 is a left side view showing a state in which a hood of an upper rotating body according to a first embodiment of the present invention is open. FIG. [Figure 4] 1 is a partially enlarged perspective view showing a bonnet opening and closing structure according to a first embodiment of the present invention. [Figure 5] 3 is a partially enlarged perspective view of the vicinity of a vehicle frame-side connecting portion in the bonnet opening / closing structure relating to the first embodiment of the present invention. FIG. [Figure 6] 3 is a partially enlarged perspective view of the vicinity of a vehicle frame-side connecting portion in the bonnet opening / closing structure relating to the first embodiment of the present invention. FIG. [Figure 7] 1 is an enlarged plan view showing a main part of a bonnet opening / closing structure according to a first embodiment of the present invention. [Figure 8] 8 is a cross-sectional view taken along the line AA in FIG. 7. [Figure 9] FIG. 6 is a partially enlarged perspective view showing a bonnet opening and closing structure according to a second embodiment of the present invention. [Figure 10] FIG. 10 is a partially enlarged perspective view of the vicinity of a vehicle frame-side connecting portion in a bonnet opening / closing structure relating to a second embodiment of the present invention. [Figure 11]FIG. 10 is a partially enlarged perspective view of the hood-side connecting portion and its surroundings in the hood opening / closing structure relating to the second embodiment of the present invention. [Figure 12] FIG. 6 is an enlarged plan view showing a main part of a bonnet opening / closing structure according to a second embodiment of the present invention. [Figure 13] 13 is a cross-sectional view of FIG. 12 taken along the line B-B. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention aims to assist the opening and closing of a hood of a construction machine having a driver's seat located above the hood by providing a structure that applies an upward biasing force to the hood. Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] In this embodiment, an excavator, which is a slewing work vehicle, will be described as an example of the construction machine according to the present invention. However, the construction machine according to the present invention is not limited to excavators, and can be widely applied to other construction machines such as bulldozers, compact track loaders, and skid steer loaders.

[0021] [First embodiment] A first embodiment of the present invention will be described. The overall configuration of an excavation machine 1 according to this embodiment will be described with reference to Figures 1 to 3. As shown in Figure 1, the excavation machine 1 is a relatively small, so-called mini-excavator, and is equipped with a self-propelled traveling body and, as working devices, an excavation device 3 and an earth removal device 4 attached to the traveling body.

[0022] The excavation machine 1 has a pair of left and right crawler-type running units 6 provided on both the left and right sides of a base unit (not shown) on the running body, a swivel bearing 5 as a swivel support device provided on the top of the base unit, and a swivel frame 7 provided on the swivel bearing 5.

[0023] The excavation machine 1 as a revolving work machine has, as a revolving configuration, an upper revolving body 20A and a lower traveling body 20B that rotatably supports the upper revolving body 20A. The upper revolving body 20A is mounted on the lower traveling body 20B and is provided so as to be revolvable about a predetermined rotation axis that extends in the up-down direction relative to the lower traveling body 20B.

[0024] In the excavator 1 according to this embodiment, the upper rotating body 20A includes the rotating frame 7, the driving section 8 provided on the rotating frame 7, and the excavation device 3 provided in front of the rotating frame 7. The excavation device 3 is not shown in Figures 2 and 3. The lower traveling body 20B includes the left and right traveling sections 6, 6 and the soil removal device 4.

[0025] A swing motor (not shown), such as an electric motor or hydraulic motor, is provided as a drive source for the swing bearing 5 serving as a swing support device. That is, the upper swing body 20A is supported rotatably relative to the lower traveling body 20B via the swing bearing 5. The excavator 1 has a small rear swing type configuration so that, during the swing operation of the upper swing body 20A, the rear end of the swing frame 7 fits within the width of the left and right traveling parts 6 in the closed state.

[0026] The rotating frame 7 is configured to have a substantially circular shape in a plan view, and a driver's section 8 for driving and operating the traveling section 6, the excavation device 3, and the soil removal device 4 is provided on the rotating frame 7. An engine room 12 covered with a bonnet 9 is provided at the rear of the floor 8a of the driver's section 8, and a driver's seat 10 on which an operator sits and a pair of left and right work operation sections 13 are provided on the bonnet 9. The bonnet 9 also serves as a seat mount that supports the driver's seat 10.

[0027] The hood 9 has a generally box-like shape with an open bottom, and is connected to the rear end of the revolving frame 7 via a hinge mechanism 80 so that it can be opened and closed. A locking mechanism (not shown) that can hold the hood 9 in a closed state is provided at the front end of the hood 9. The locking mechanism is configured to operate in conjunction with the operation of an unlocking handle 29 located on the front of the hood 9, and by operating the unlocking handle 29, a maintenance technician can switch the hood 9 from a locked state in which it is closed to an unlocked state in which it is open.

[0028] A belt 28 is provided between the hood 9 and the driver's seat 10. The belt 28 functions as a handle for a maintenance technician to use when opening or closing the hood 9, and is configured as a strip made of polyester fiber or the like. Both ends of the belt 28 are connected to support members 38 fixed to the hood 9.

[0029] The left and right work operation units 13 are arranged symmetrically to each other, sandwiching the driver's seat 10. The work operation unit 13 has a base unit 24 fixed to the hood 9, and a lever support unit 25 that supports a work operation lever 26 and a lock lever 27. The lever support unit 25 is rotatably provided on the hood 9 by being connected to the base unit 24 via a connecting shaft (not shown) that is provided at the rear of the base unit 24 and has an axial direction in the left-right direction. The work operation lever 26 is an operating tool for operating the excavating device 3, and is provided at the top of the lever support unit 25 so as to protrude diagonally forward.

[0030] The lock lever 27 is operated to switch the position of the work operation unit 13, and is provided at the front lower part of the lever support part 25, protruding obliquely upward. When the operator operates the lock lever 27, the lever support part 25 rotates about the left-right axis of the connecting shaft. This allows the position of the work operation unit 13 to be switched between an operating position (see FIG. 2) in which the operator performs normal operation, and a rearward retracted position (see FIG. 3) in which the work operation unit 13 is flipped rearward from the operating position. The rearward retracted position allows for a larger space for the operator to get into the driver's seat 10.

[0031] An operating unit 11 is provided on the front part of the floor 8a of the driver's unit 8, which is operated by an operator seated in a driver's seat 10. The operating unit 11 is provided with a travel operating unit such as a travel lever for operating the travel of the excavator 1. The left and right side surfaces of the driver's unit 8 below the floor 8a are covered by side covers 14.

[0032] The engine room 12 is provided with an engine as a drive source, a fuel tank for storing fuel for the engine, and a hydraulic oil tank for storing hydraulic oil to be supplied to various hydraulic cylinders and the like provided in the excavation machine 1. The engine is configured as, for example, a diesel engine. Note that the engine and other components are not shown in Figure 3.

[0033] The excavator 3 is a front working implement provided at the front of the excavator 1. The base end of the excavator 3 is supported via a bracket 16 on a support bracket 15 provided in the left-right center of the front end of the revolving frame 7. The excavator 3 has a boom 17 that forms the base end, an arm 18 connected to the tip of the boom 17, and a bucket 19 attached to the tip of the arm 18.

[0034] The excavator 3 also has a boom cylinder 21 that rotates the boom 17, an arm cylinder 22 that rotates the arm 18, and a bucket cylinder 23 that rotates the bucket 19. All of these cylinders are configured as hydraulic cylinders.

[0035] The earth removal device 4 is attached to the front side of the base. The earth removal device 4 forms a support frame between the left and right running parts 6, 6 and has a pair of left and right arms 31 extending in the front-to-rear direction, a blade 32 which is a blade provided at the tip end of the pair of left and right arms 31, and a blade cylinder 33 which raises and lowers the blade 32. The support frame including the arms 31 is provided so as to be able to raise and lower and rotate relative to the base, thereby allowing the blade 32 to raise and lower and rotate.

[0036] The blade cylinder 33 is a hydraulic cylinder that is installed in a front-to-rear manner between the base unit and the blade 32. The upper side of the blade cylinder 33 is covered by a cylinder cover 39. When the blade cylinder 33 extends and retracts, the blade 32 moves up and down and rotates via the support frame.

[0037] The running units 6 have a configuration in which tracks are wound around multiple rotating bodies. The running units 6 have drive wheels 48 as rotating bodies at their rear ends. The drive wheels 48 are sprockets that rotate when driven by the traveling motors 41. On the left and right running units 6, the drive wheels 48 are driven to rotate by the driving force of the traveling motors 41, thereby driving the running units 6 to travel.

[0038] In the excavation machine 1 having the above-described configuration, the desired operation and work are performed by the operator seated in the driver's seat 10 appropriately operating the travel lever, work operation lever 26, etc. Specifically, for example, operation of the travel lever causes the excavation machine 1 to travel forward and backward in a straight line or to turn left and right. Furthermore, operation of the work operation lever 26 causes the excavation device 3 to perform excavation work.

[0039] The opening and closing structure of the hood 9 in the upper rotating body 20A will be described with reference to Figures 4 to 8. Note that Figures 4 to 8 omit illustration of the engine and other components disposed in the engine room 12. Figures 4 to 8 also show an enlarged view of the connection portion between the hood 9 and the rotating frame 7 when the hood 9 is open as shown in Figure 3.

[0040] The rotating frame 7 in the upper rotating body 20A is a body frame that rotatably supports the bonnet 9, and at the connection portion between the bonnet 9 and the rotating frame 7, a hinge mechanism 80 having a body frame side connection portion 81 and a bonnet side connection portion 91, and a torsion coil spring 100 as a force-applying means are provided.

[0041] A pair of left and right mounting support parts 61 for attaching the bonnet-side connecting part 91 of the hinge mechanism 80 are provided on the inner wall side of the rear end of the bonnet 9. The mounting support parts 61 are provided with hook parts 62 for hanging wires and hoses connected to devices arranged in the engine room 12. The hook parts 62 are made by bending wire, and their shape can be changed depending on the thickness and number of wires to be hung.

[0042] Torsion coil spring 100 is a so-called double torsion spring that receives a torsional moment around the central axis of the coil and has two coil portions 101a, 101b wound with a metal wire. Torsion coil spring 100 further has an intermediate arm portion 103 located on the inner side in the width direction (left-right direction) and connecting two coil portions 101a, 101b, and linear arm portions 102a, 102b extending from the outer sides of two coil portions 101a, 101b in the width direction. Torsion coil spring 100 has a bilaterally symmetrical structure in which two coil portions 101a, 101b are connected by intermediate arm portion 103 that is curved in a substantially inverted U shape. Furthermore, the angle between linear arm portions 102a, 102b and intermediate arm portion 103 is configured to be a predetermined angle (e.g., 60 to 160 degrees) when no load is applied. The torsion coil spring 100 is disposed between the vehicle frame side connecting portion 81 and the bonnet side connecting portion 91, and biases the bonnet 9 to rotate upward.

[0043] The revolving frame 7 has a rear wall 71 that serves as a base to which the hood 9 is hinged. Two stays 73 that rise from the bottom of the revolving frame 7 are provided on the left and right sides of the inner surface of the rear wall 71. A vehicle frame side connecting part 81 is fixed in a spanning state to the upper ends of these stays 73.

[0044] The body frame side connecting portion 81 has a support plate portion 82, a pair of left and right hinge arms 86a, 86b provided at both ends of the support plate portion 82, and mounting base portions 83a, 83b provided at both ends of the support plate portion 82, respectively.

[0045] The support plate 82, the left and right hinge arms 86a, 86b, and the mounting bases 83a, 83b are integrally formed, for example, by bending a metal plate cut to a predetermined shape. Each of the left and right hinge arms 86a, 86b has a hole 89 at its tip end into which a hinge shaft 87 is inserted. The hinge arms 86a, 86b are provided so as to protrude rearward from the left and right ends of the support plate 82 that the surfaces on which the hole 89 is provided are parallel to each other. The mounting bases 83a, 83b are used to attach the aircraft frame-side connecting unit 81 to the stay 73, and are provided at both ends of the support plate 82 below the hinge arms 86a, 86b so as to form horizontal surfaces corresponding to the upper surfaces of the stays 73. The mounting base portions 83a, 83b are provided with holes (not shown) through which the mounting screws 74 are inserted, and by screwing the mounting base portions 83a, 83b to the upper surface of the stay 73, the machine frame side connecting portion 81 is fixed to the swivel frame 7.

[0046] The bonnet-side connecting portion 91 has a pair of left and right bonnet connecting portions 93a, 93b for connecting to the bonnet 9, a pair of left and right movable arms 96a, 96b protruding from the bonnet connecting portions 93a, 93b, respectively, and a connecting plate portion 92 connecting the left and right movable arms 96a, 96b. The bonnet-side connecting portion 91 also has a shaft support portion 95 that supports a support shaft 94 around which coil portions 101a, 101b of the torsion coil spring 100 are extrapolated.

[0047] The left bonnet connection portion 93a and the left movable arm 96a are integrally formed, for example, by bending a metal plate cut to a predetermined shape. The right bonnet connection portion 93b and the right movable arm 96b are similarly formed. The connecting plate portion 92 is also integral with the bonnet connection portions 93a, 93b and the movable arms 96a, 96b by welding the movable arms 96a, 96b to both ends of the connecting plate portion 92. The left and right bonnet connection portions 93a, 93b are provided with holes (not shown) for inserting mounting screws 78, and the bonnet-side connecting portion 91 is fixed to the bonnet 9 by screwing the bonnet connection portions 93a, 93b to the mounting support portion 61 of the bonnet 9.

[0048] Holes 99 corresponding to the holes 89 of the left and right hinge arms 86a, 86b are provided at the tip sides of each of the left and right movable arms 96a, 96b. The left and right movable arms 96a, 96b are attached to the hood 9 via hood connection parts 93a, 93b so as to be spaced apart by the same width as the left and right hinge arms 86a, 86b. The movable arms 96a, 96b are connected to the hinge arms 86a, 86b via the hinge shaft 87, and thereby rotate about the axis of the hinge shaft 87 when the hood 9 is opened or closed.

[0049] The shaft support portion 95 has a pair of left and right shaft support arms 97a, 97b, each having a hole at its tip end through which both ends of a support shaft 94 are inserted, and an arm support plate 98 that connects the left and right shaft support arms 97a, 97b to each other. The support shaft 94 is a guide rod that guides the rotation of the coil portions 101a, 101b of the torsion coil spring 100 when the hood 9 is opened or closed, and both ends of the support shaft 94 are fitted into holes in the left and right shaft support arms 97a, 97b. The left and right shaft support arms 97a, 97b and the arm support plate 98 are integrally formed by, for example, bending. By fixing the arm support plate 98 to the connecting plate portion 92 with the fixing screws 76, the support shaft 94 is positioned on the same axis C as the hinge shaft 87 (see FIG. 8 ). In other words, the support shaft 94 is positioned so that its axis substantially coincides with the axis of the hinge shaft 87.

[0050] The body-frame-side connecting part 81 and the bonnet-side connecting part 91 are connected as follows: Coil portions 101a, 101b of a torsion coil spring 100 are fitted onto a support shaft 94 provided on the body-frame-side connecting part 81 with two arms 102a, 102b and an intermediate arm 103 facing upward, and both ends of the support shaft 94 are supported by shaft support arms 97a, 97b. In this state, a hinge shaft 87 is inserted through holes 89 of the aligned left and right hinge arms 86a, 86b of the body-frame-side connecting part 81 and holes 99 of the left and right movable arms 96a, 96b of the bonnet-side connecting part 91. An insertion hole is provided at the tip of the hinge shaft 87 for inserting a locking pin 79, also known as a split pin. By inserting a retaining pin into this insertion hole, the hinge shaft 87 is prevented from falling out of the hole portion 89 and the hole portion 99 .

[0051] A pair of hinge shafts 87 are provided spaced apart in the left-right direction of the machine body so as to correspond to the hole portions 89 of the left and right hinge arms 86a, 86b and the hole portions 99 of the left and right movable arms 96a, 96b. Furthermore, the support shaft 94 of the torsion coil spring 100 is disposed between the pair of hinge shafts 87. Each hinge shaft 87 is disposed so that one end abuts against an end of the support shaft 94, and also functions as a retainer for the support shaft 94. Therefore, the support shaft 94 does not have to be fixed to the left and right shaft support arms 97a, 97b.

[0052] In this manner, in the hinge mechanism 80 of this embodiment, the aircraft frame side connecting part 81 and the bonnet side connecting part 91 are connected by hinge-connecting the hinge arms 86a, 86b and the movable arms 96a, 96b via the hinge shaft 87. At this time, the torsion coil spring 100 is disposed between the aircraft frame side connecting part 81 and the bonnet side connecting part 91.

[0053] The intermediate arm 103 of the torsion coil spring 100 abuts against the support plate 82 of the vehicle-frame-side connecting portion 81 when the hood 9 is open or closed at an angle smaller than a predetermined angle. The support plate 82 functions as a vehicle-frame-side receiving portion against which the intermediate arm 103 abuts. Furthermore, two linear arms 102a, 102b extending outward in the width direction from the two coil portions 101a, 101b abut against an arm support plate 98 of the shaft support portion 95 when the hood 9 is open or closed at an angle smaller than a predetermined angle. The arm support plate 98 is fixed to the connecting plate 92 of the hood-side connecting portion 91 and functions as a hood-side receiving portion against which the arms 102a, 102b of the torsion coil spring 100 abut. That is, the arms 102a, 102b receive a load from the hood 9 via the arm support plate 98 depending on the opening angle of the hood 9.

[0054] When the hood 9 is closed by the action of the locking mechanism, a load is applied to the torsion coil spring 100 in the coil winding direction. When the lock release handle 29 is operated to release the lock on the hood 9 by the locking mechanism, the load on the hood 9 is reduced by the biasing force of the torsion coil spring 100 that rotates the hood 9 upward, and the hood 9 rotates around the axis of the hinge shaft 87. The biasing force at this time is adjusted by the angle between the arms 102a, 102b and the intermediate arm 103 of the torsion coil spring 100, the number of turns of the coil portions 101a, 101b, etc.

[0055] The maximum open position of the hood 9 is restricted to a predetermined position (maximum open state) by a rotation stopper (not shown). That is, the hood 9, which is raised by the biasing force of the torsion coil spring 100, is stopped from rotating at a predetermined position by the rotation stopper. The biasing force of the torsion coil spring 100 is greatest when the hood 9 is closed, and gradually weakens as the opening angle of the hood 9 increases. That is, the torsion coil spring 100 acts within a rotation range of the hood 9 from the closed state to a rotational position intermediate therewith (for example, an angle range of 70 to 80 degrees) from the closed state to the maximum open state.

[0056] In this embodiment, since the torsion coil spring 100 is a double torsion spring, a stable torque can be obtained by using a total of three load points: the contact points between the two arm portions 102a, 102b and the arm support plate 98 at the bonnet side connecting portion 91, and the contact point between the intermediate arm portion 103 and the support plate portion 82 at the body frame side connecting portion 81.

[0057] In this embodiment, the hinge mechanism 80 has a body frame side connecting portion 81 and a bonnet side connecting portion 91, and the torsion coil spring 100 biases the bonnet 9 to rotate it upward, so that the bonnet 9 can be opened by releasing the locking mechanism. By using a double torsion spring as the torsion coil spring 100, a strong biasing force can be applied to the bonnet 9, making it excellent in terms of durability.

[0058] [Second embodiment] A second embodiment of the present invention will be described with reference to Figures 9 to 13. Note that components common to the first embodiment are denoted by the same reference numerals and descriptions thereof will be omitted where appropriate. In this embodiment, the opening and closing structure of the hood 9 in the upper rotating body 20A is different from that of the first embodiment.

[0059] As shown in Figures 8 to 11, in the connecting portion between the bonnet 9 and the revolving frame 7 in this embodiment, the torsion coil spring 200 used as the force-applying means is a so-called single torsion spring having one coil portion 201, and the coil portion 201 is extrapolated to the support shaft 184 provided on the body frame side connecting portion 181.

[0060] Torsion coil spring 200 in this embodiment has coil portion 201 wound with metal wire, and two arms 202a and 202b extending from both ends of coil portion 201. Arm portion 202a has a straight shape, and arm portion 202b has a shape with a single bent tip. Arm portion 202a and arm portion 202b are provided at both ends of coil portion 201 so that they form a predetermined angle (for example, 90 degrees to 160 degrees) with respect to each other when no load is applied. Torsion coil spring 200 is disposed between body frame side connecting portion 181 and bonnet side connecting portion 191, and biases bonnet 9 to rotate upward.

[0061] The machine body frame side connecting part 181 has a support plate part 82, a pair of left and right hinge arms 86a, 86b provided on both ends of the support plate part 82, and left and right mounting base parts 83a, 83b provided on both ends of the support plate part 82. Each of the left and right hinge arms 86a, 86b has a hole part 89 at the tip side into which a hinge shaft 87 is inserted. The machine body frame side connecting part 181 is fixed to the revolving frame 7 by fastening each of the mounting base parts 83a, 83b to the upper surface of the stay 73 with screws. The machine body frame side connecting part 181 also has a support shaft 184 around which the coil part 201 of the torsion coil spring 200 is inserted, and a shaft support part 185 that supports the support shaft 184.

[0062] The shaft support portion 185 is provided by welding to protrude from the rearward-facing surface of the support plate portion 82 so that the support surface that supports the support shaft 184 is parallel to the plate surfaces of the left and right hinge arms 86a, 86b. The support shaft 184 is a guide rod that guides the rotation of the coil portion 201 of the torsion coil spring 200 when the hood 9 is opened or closed, and has one end connected to the shaft support portion 185 by welding and the other end serving as a free end into which the coil portion 201 of the coil spring 200 can be inserted. The support shaft 184 is cantilevered by the shaft support portion 185, and is thereby arranged on the same axis C as the hinge shaft 87 (see FIG. 13 ). That is, the support shaft 184 is provided in the vehicle-frame-side connecting portion 181 so that the axis of the support shaft 184 substantially coincides with the axis of the hinge shaft 87. A screw hole 177 is provided on the free end side of the support shaft 184, and a washer 175 is fixed to the free end with a fixing screw 176, thereby preventing the torsion coil spring 200 from falling off the support shaft 184.

[0063] The bonnet-side coupling portion 191 has a pair of left and right bonnet connection portions 93a, 93b for connection to the bonnet 9, and a pair of left and right movable arms 96a, 96b respectively protruding from the bonnet connection portions 93a, 93b. The bonnet-side coupling portion 191 also has a bonnet-side receiving portion 197 with which one arm portion 202a of the torsion coil spring 100 abuts.

[0064] The hood connection portions 93a, 93b are screwed to the mounting support portions 61 of the hood 9, thereby fixing the hood side coupling portion 191 to the hood 9. Furthermore, the movable arms 96a, 96b are connected to the hinge arms 86a, 86b via the hinge shaft 87, and thereby rotate about the axis of the hinge shaft 87 when the hood 9 is opened or closed.

[0065] Bonnet-side receiving portion 197 has a generally U-shape and connects between left and right movable arms 96a, 96b. Left and right movable arms 96a, 96b and bonnet-side receiving portion 197 are connected to each other by welding. One arm 202a of torsion coil spring 200 abuts against bonnet-side receiving portion 197.

[0066] The body-frame-side coupling part 81 and the bonnet-side coupling part 191 are coupled as follows: A coil portion 201 of a torsion coil spring 200 is fitted onto a support shaft 184 provided on the body-frame-side coupling part 181 with its two arms 102a, 102b facing upward, and a washer 175 is fixed to the free end of the support shaft 184 with a fixing screw 176. In this state, a hinge shaft 87 is inserted through holes 89 of the aligned left and right hinge arms 86a, 86b of the body-frame-side coupling part 181 and holes 99 of the left and right movable arms 96a, 96b of the bonnet-side coupling part 91. An insertion hole is provided on the tip side of the hinge shaft 87 for inserting a locking pin 79, also known as a split pin. By inserting a retaining pin into this insertion hole, the hinge shaft 87 is prevented from falling out of the hole portion 89 and the hole portion 99 .

[0067] In this way, the left and right hinge arms 86a, 86b and the left and right movable arms 96a, 96b are hingedly connected by the hinge shaft 87 to connect the body frame side connecting part 181 and the bonnet side connecting part 191. As a result, the torsion coil spring 200 is disposed between the body frame side connecting part 181 and the bonnet side connecting part 191.

[0068] Of the two arms 202a, 202b of the torsion coil spring 200, the arm 102a abuts against the bonnet-side receiving portion 197 when the bonnet 9 is open at an angle smaller than a predetermined angle or when the bonnet 9 is closed. That is, the arm 202a receives the load of the bonnet 9 via the bonnet-side receiving portion 197 depending on the opening angle of the bonnet 9. On the other hand, the other arm 202b abuts against the support plate 82 of the vehicle-frame-side connecting portion 81 when the bonnet 9 is open at an angle smaller than a predetermined angle or when the bonnet 9 is closed. The support plate 82 with which the arm 202b abuts functions as the vehicle-frame-side receiving portion that receives the arm 202b of the torsion coil spring 200 on the vehicle frame side.

[0069] When the hood 9 is closed by the action of the locking mechanism, a load is applied to the torsion coil spring 200 in the coil winding direction. When the lock release handle 29 is operated to release the lock on the hood 9 by the locking mechanism, the biasing force of the torsion coil spring 200 that rotates the hood 9 upward causes the hood 9 to rotate about the axis of the hinge shaft 87, and the hood 9 opens. The biasing force at this time is adjusted by the angle formed by the two arms 202a, 202b of the torsion coil spring 200, the number of turns of the coil portion 201, and the like. Furthermore, like the torsion coil spring 100 in the first embodiment, the torsion coil spring 200 acts within a rotation range of the hood 9 from the closed state to the maximum open state (for example, an angle range of 70 to 80 degrees), and within a rotation range from the closed state to an intermediate rotation position (for example, an angle range of about 40 degrees).

[0070] In this embodiment, the hinge mechanism 80 has a body frame side connecting portion 181 and a bonnet side connecting portion 191, and a torsion coil spring 200 that biases the bonnet 9 to rotate upward, thereby reducing the load on the bonnet 9 and allowing the bonnet 9 to be easily opened by releasing the locking mechanism.

[0071] The excavation machine 1 of the first and second embodiments having the above-described configuration can be said to have the following configuration: That is, the excavation machine 1 has an engine room 12 arranged at the rear of the machine body frame (swivel frame 7), a bonnet 9 covering the engine room 12, and a driver's seat 10 arranged above the bonnet 9, and also includes a hinge mechanism 80 having a machine body frame-side connecting part 81 and a bonnet-side connecting part 91 and rotatably connecting the bonnet 9 to the machine body frame (swivel frame 7), and biasing force applying means (torsion coil springs 100, 200) arranged between the machine body frame-side connecting part 81 and the bonnet-side connecting part 91 and applying an upward biasing force to the bonnet 9.

[0072] By arranging the biasing force applying means (torsion coil springs 100, 200) between the body frame side connecting portions 81, 181 and the hood side connecting portions 91, 191 of the hinge mechanism 80, a space-saving configuration can be provided that assists a maintenance technician in opening and closing the hood 9. Furthermore, because the biasing force applying means (torsion coil springs 100, 200) biases the hood 9 to rotate it upward, a maintenance technician can release the locking mechanism of the hood 9 and open the hood 9, which is connected to the revolving frame 7 by the hinge mechanism 80, with less force than before. Furthermore, when closing the hood 9, the biasing force of the biasing force applying means (torsion coil springs 100, 200) slows down the speed at which the hood 9 closes, preventing fingers from getting caught when the hood 9 is closed.

[0073] With this configuration, the workload when opening and closing the bonnet 9 is reduced, and the maintainability of the engine and other components arranged in the engine room 12 inside the bonnet 9 can be improved.

[0074] The above-described embodiment is an example of the present invention, and the construction machine according to the present invention is not limited to the above-described embodiment. Therefore, even if it is not the above-described embodiment, various modifications can be made depending on the design, etc., as long as they do not deviate from the technical concept of the present invention. Furthermore, the effects described in this disclosure are merely examples and are not limited thereto, and other effects may also be obtained. Furthermore, the configurations of the above-described embodiments and the configurations of the modified examples can be combined as appropriate.

[0075] In the first embodiment described above, the support shaft 94, which is a guide rod for the torsion coil spring, is provided in the bonnet-side coupling part 91, and in the second embodiment, the support shaft 184 is provided in the aircraft-frame-side coupling part 181. As such, as long as the torsion coil spring can be arranged between the aircraft-frame-side coupling part 81, 181 and the bonnet-side coupling part 91, 191 of the hinge mechanism 80, the support shaft of the torsion coil spring may be supported in the bonnet-side coupling part 91 as in the first embodiment, or may be supported in the aircraft-frame-side coupling part 181 as in the second embodiment. In this way, by providing the biasing force imparting means in the space inside the hinge mechanism 80, there is no need to change the layout of the devices in the engine room 12 to newly provide space for arranging the biasing force imparting means, and the burdens of design and assembly are reduced.

[0076] Furthermore, in the first and second embodiments described above, the structure for supporting the torsion coil spring is integrated with the bonnet side connecting portion 91 or the body frame side connecting portion 181 in the hinge mechanism 80, thereby making the work of attaching the bonnet 9 to the body frame (swivel frame 7) more efficient.

[0077] Furthermore, in the first and second embodiments described above, the torsion coil springs 100, 200 are supported by support shafts 94, 184 that are arranged coaxially with the hinge shaft 87 in the hinge mechanism 80, thereby enabling smooth rotational movement of the hood 9.

[0078] In the first and second embodiments described above, the hinge mechanism 80 that connects the hood 9 to the aircraft frame (swivel frame 7) and the biasing force applying means (torsion coil springs 100, 200) that applies an upward biasing force to the hood 9 are provided at the rear of the engine room 12, but this is not limiting. The hinge mechanism 80 and the biasing force applying means may be arranged in positions interchanged with the locking mechanism and unlocking handle 29 of the hood 9. In other words, the hinge mechanism 80 may be provided in front of the engine room 12.

[0079] Furthermore, in the first and second embodiments described above, an excavator 1 is described as having the driver's seat 10 and a pair of left and right work operation units 13 provided on the hood 9, but the work operation units 13 may be provided in the operation unit 11. In the case of an excavator that does not have work operation units 13 on the left and right of the driver's seat 10, a hinge mechanism 80 and a biasing force applying means may be provided on the left and right ends of the hood 9.

[0080] In the first and second embodiments described above, torsion coil springs 100, 200 are used as the biasing force applying means, but an elastic body that utilizes the reaction force of a compression load, such as a compression coil spring, may also be used as long as it can bias the hood 9 to rotate upward around the hinge axis 87. [Explanation of symbols]

[0081] 1 Excavation machine (construction machinery) 6 Running part 7. Rotating frame (aircraft frame) 9. Bonnet 10 Driver's seat 12 Engine Room 13 Work operation section 20A Upper rotating body 20B Undercarriage 41 Travel motor 48 Drive wheels 71 Rear wall 73 Stay 80 Hinge mechanism 81 Airframe side connection part 82 Support plate part 83 Mounting base 86 Hinge arm 87 Hinge shaft 91 Bonnet side connection part 93 Bonnet connection 94 Support shaft 95 Shaft support part 97 Axis support arm 100 Torsion coil spring (biasing force imparting means) 101 Coil section 102 Arm 103 Middle arm 181 Airframe side connection part 184 Support shaft 185 Shaft support part 191 Bonnet side connection part 200 Torsion coil spring (biasing force imparting means) 201 Coil section 202 Arm

Claims

1. A construction machine comprising: an engine room arranged at the rear of a machine frame; a bonnet covering the engine room; and a driver's seat arranged above the bonnet, a hinge mechanism having an aircraft frame side connecting portion and a bonnet side connecting portion, the hinge mechanism rotatably connecting the bonnet to the aircraft frame; a biasing force applying means disposed between the vehicle body frame side connecting portion and the bonnet side connecting portion, and applying an upward biasing force to the bonnet, the biasing force applying means is supported on a support shaft that is provided coaxially with the hinge shaft of the hinge mechanism, and one side of the support shaft abuts against the machine frame side connecting portion, and the other side of the support shaft abuts against the bonnet side connecting portion, thereby applying the biasing force to the bonnet.

2. the hinge shafts are provided as a pair spaced apart in the left-right direction of the vehicle frame, The support shaft is disposed between the pair of left and right hinge shafts.

2. The construction machine according to claim 1.

3. The biasing force applying means is a torsion coil spring.

3. The construction machine according to claim 1 or 2.

4. The torsion coil spring has two coil portions wound with a wire, and the two coil portions are extrapolated onto the support shaft provided in the bonnet-side connecting portion.

4. The construction machine according to claim 3.

5. The torsion coil spring has an intermediate arm portion provided on the widthwise inner side of the two coil portions and connecting the two coil portions, the intermediate arm portion abutting on an aircraft frame-side receiving portion provided on the aircraft frame-side connecting portion, and each of the arm portions extending from the widthwise outer sides of the two coil portions abutting on a bonnet-side receiving portion provided on the bonnet-side connecting portion.

5. The construction machine according to claim 4.

6. the torsion coil spring has a coil portion around which a wire is wound, and the coil portion is inserted onto the support shaft provided on the aircraft frame side connecting portion.

4. The construction machine according to claim 3.

7. The torsion coil spring has an arm portion extending from one end of the coil portion that abuts against an aircraft frame-side receiving portion provided at the aircraft frame-side connecting portion, and an arm portion extending from the other end of the coil portion that abuts against a bonnet-side receiving portion provided at the bonnet-side connecting portion.

7. The construction machine according to claim 6.

8. 8. The construction machine according to claim 1, wherein the hinge mechanism and the biasing force applying means are disposed rearward of the engine room.

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