JP7768792B2 - Construction machinery - Google Patents

Description

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

Conventionally, construction machinery such as excavators has a structure in which an upper rotating body is mounted on a crawler-type lower traveling body so that it can rotate freely, with an engine located on the rear side of the upper rotating body's rotating frame and covered by a hood. In such construction machinery, the hood serves as an engine room where the engine and other equipment, as well as the fuel tank, are located, and the hood is configured to be openable and closable to facilitate maintenance of the engine and other components.

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 at the front end of the hood and the hood is opened and closed by rotating in the front-to-rear direction around the hinge axis.

JP 2010-71005 A

According to the configuration disclosed in Patent Document 1, the hood is simply connected to the members that make up the rotating frame via hinges. Therefore, when opening the hood for maintenance and 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 above 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.

In addition, with 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 devices such as gas springs and torsion bars to assist in opening and closing the hood.

The present invention was made in consideration of the above-mentioned problems, and relates to a hood opening and closing structure for construction machinery in which the driver's seat is located above the hood. Its objective is to provide a construction machinery with a simple configuration that assists in the opening and closing of the hood and improves the maintainability of the equipment located in the engine room inside the hood.

The construction machine of the present invention is equipped with an engine room located behind the machine frame, a bonnet covering the engine room, and a driver's seat located above the bonnet. It is characterized by the following: a hinge mechanism having a machine frame-side connecting portion and a bonnet-side connecting portion, which rotatably connects the bonnet to the machine frame; and a biasing force applying means, which is located between the machine frame-side connecting portion and the bonnet-side connecting portion, and which applies an upward biasing force to the bonnet.

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

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

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.

In another aspect of the present invention, the construction machine is characterized in that the torsion coil spring has two coil portions wound with wire, and the two coil portions are inserted onto the support shaft provided on the bonnet-side connecting portion.

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 and 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.

In another aspect of the present invention, the construction machine has a torsion coil spring having a coil portion wound with wire, and the coil portion is inserted onto the support shaft provided on the machine frame side connecting portion.

In another aspect of the present invention, the construction machine 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.

A construction machine according to another aspect of the present invention is characterized in that the hinge mechanism and the biasing force applying means are disposed behind the engine room.

This invention relates to a hood opening and closing structure for construction machinery with a driver's seat located above the hood, and its simple configuration assists in opening and closing the hood and improves the ease of maintenance of equipment located in the engine room inside the hood.

1 is a left side view of an excavation machine according to a first embodiment of the present invention. FIG. FIG. 1 is a perspective view of an upper rotating body according to a first embodiment of the present invention. FIG. 2 is a left side view showing a state in which a hood of an upper rotating body according to the first embodiment of the present invention is open. 1 is a partially enlarged perspective view showing a bonnet opening and closing structure according to a first embodiment of the present invention; 3 is a partially enlarged perspective view of the vicinity of a vehicle frame-side connecting portion in the bonnet opening/closing structure according to the first embodiment of the present invention; FIG. 3 is a partially enlarged perspective view of the vicinity of a vehicle frame-side connecting portion in the bonnet opening/closing structure according to the first embodiment of the present invention; FIG. 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; 8 is a cross-sectional view taken along line AA in FIG. 7. FIG. 6 is a partially enlarged perspective view showing a bonnet opening and closing structure according to a second embodiment of the present invention. FIG. 10 is a partially enlarged perspective view of the vicinity of a vehicle frame-side connecting portion in a bonnet opening/closing structure according to a second embodiment of the present invention. FIG. 10 is a partially enlarged perspective view of the hood-side connecting portion and its surroundings in the hood opening/closing structure according to the second embodiment of the present invention. 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. This is a cross-sectional view taken along the line BB in FIG.

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

In this embodiment, an excavator, which is a slewing work vehicle, will be used 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.

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

The excavator 1 has a pair of crawler-type running units 6 mounted on the left and right sides of a base unit (not shown) on the running body, a swivel bearing 5 serving as a swivel support device mounted on top of the base unit, and a swivel frame 7 mounted on the swivel bearing 5.

The excavation machine 1, which serves as a slewing work machine, has a slewing configuration consisting of an upper slewing body 20A and a lower running body 20B that slewingly supports the upper slewing body 20A. The upper slewing body 20A is mounted on the lower running body 20B and is slewing around a predetermined rotation axis that extends vertically relative to the lower running body 20B.

In the excavation work machine 1 according to this embodiment, the upper rotating body 20A includes the rotating frame 7, the operating section 8 mounted on the rotating frame 7, and the excavation device 3 mounted in front of the rotating frame 7. Note that 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.

A swing motor (not shown), such as an electric motor or hydraulic motor, is provided as the drive source for the swing bearing 5, which serves as a swing support device. In other words, the upper swing body 20A is supported rotatably relative to the lower track body 20B via the swing bearing 5. The excavator 1 has a small rear swing configuration so that, when the upper swing body 20A swings, the rear end of the swing frame 7 fits within the width of the left and right track bodies 6 in the closed state.

The rotating frame 7 is configured in a roughly circular shape when viewed from above, and is provided on the rotating frame 7 with a driver's section 8 for driving and operating the traveling section 6, excavation equipment 3, and soil removal equipment 4. Located at the rear of the floor 8a of the driver's section 8 is an engine room 12 covered by a hood 9, and on the hood 9 are a driver's seat 10 where the operator sits and a pair of left and right work operation sections 13. The hood 9 also serves as a seat mount that supports the driver's seat 10.

The hood 9 has a generally box-like shape with an open bottom, and is connected to the rear end of the rotating 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 position 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.

A belt 28 is provided between the hood 9 and the driver's seat 10. This belt 28 functions as a handle for maintenance technicians when opening and closing the hood 9, and is constructed 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.

The left and right work operation units 13 are arranged symmetrically on either side of 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 mounted 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 excavation device 3 and is provided at the top of the lever support unit 25, protruding diagonally forward.

The lock lever 27 is operated to switch the position of the work operation unit 13 and is located at the front lower part of the lever support part 25, protruding diagonally upward. When the operator operates the lock lever 27, the lever support part 25 rotates around 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 Figure 2) in which the operator performs normal operation, and a rearward retracted position (see Figure 3) in which the unit is flipped rearward from the operating position. The rearward retracted position allows more space for the operator to enter the driver's seat 10.

A control panel 11 is provided at the front of the floor 8a of the driver's unit 8, which is operated by an operator seated in the driver's seat 10. The control panel 11 is equipped with a travel control panel, such as a travel lever, for controlling the travel of the excavator 1. The left and right sides of the driver's unit 8 below the floor 8a are covered by side covers 14.

The engine room 12 is equipped 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 supplied to the various hydraulic cylinders provided on the excavator 1. The engine is configured as, for example, a diesel engine. Note that the engine and other components are not shown in Figure 3.

The excavation device 3 is a front working device mounted on the front side of the excavation work machine 1. The base end of the excavation device 3 is supported via a bracket 16 on a support bracket 15 mounted in the center of the left and right sides of the front end of the swivel frame 7. The excavation device 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.

The excavation device 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.

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 sections 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 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 mounted so that it can be raised and lowered and rotated relative to the base, allowing the blade 32 to be raised and lowered and rotated.

The blade cylinder 33 is a hydraulic cylinder that is installed between the base and the blade 32. The upper side of the blade cylinder 33 is covered by a cylinder cover 39. The extension and contraction of the blade cylinder 33 causes the blade 32 to rise and fall and rotate via the support frame.

The running units 6 are configured with tracks wound around multiple rotating bodies. At their rear ends, the running units 6 have drive wheels 48 as rotating bodies. The drive wheels 48 are sprockets that rotate when driven by the travel motors 41. On the left and right running units 6, the drive wheels 48 are driven to rotate by the driving force of the travel motors 41, thereby driving the running units 6 to travel.

In an excavation machine 1 configured as described above, the operator seated in the driver's seat 10 appropriately operates the travel lever, work operation lever 26, etc. to perform the desired operation and work. 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.

The opening and closing structure of the hood 9 on the upper rotating body 20A will be explained using Figures 4 to 8. Note that Figures 4 to 8 omit illustration of the engine and other components located in the engine room 12. Also, Figures 4 to 8 show an enlarged view of the connection between the hood 9 and the rotating frame 7 when the hood 9 is open, as shown in Figure 3.

The revolving frame 7 of the upper revolving body 20A is an aircraft frame that rotatably supports the bonnet 9. At the connection between the bonnet 9 and the revolving frame 7, a hinge mechanism 80 having an aircraft frame-side connecting portion 81 and a bonnet-side connecting portion 91, and a torsion coil spring 100 as a biasing force applying means are provided.

A pair of left and right mounting supports 61 are provided on the inner wall of the rear end of the hood 9 for attaching the hood-side connecting portion 91 of the hinge mechanism 80. The mounting supports 61 are provided with hooks 62 for hanging wiring and hoses connected to equipment located in the engine room 12. The hooks 62 are made by bending wire, and their shape can be changed depending on the thickness and number of wires to be hung.

The torsion coil spring 100 is subjected to a torsional moment around the central axis of the coil. It is a so-called double torsion spring having two coil portions 101a, 101b wound with metal wire. Furthermore, the torsion coil spring 100 has an intermediate arm 103 located on the inner side in the width direction (left-right direction) connecting the two coil portions 101a, 101b, and linear arms 102a, 102b extending from the outer sides of the two coil portions 101a, 101b in the width direction. The torsion coil spring 100 has a bilaterally symmetrical structure in which the two coil portions 101a, 101b are connected by the intermediate arm 103, which is curved in a roughly inverted U shape. Furthermore, the angle between the linear arms 102a, 102b and the intermediate arm 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.

The rotating frame 7 has a rear wall 71 that serves as a base to which the hood 9 is hinged. Two stays 73 extend from the bottom of the rotating frame 7 on the left and right sides of the inner surface of the rear wall 71. The fuselage frame side connectors 81 are fixed in a spanning state to the upper ends of these stays 73.

The aircraft 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.

The support plate 82, left and right hinge arms 86a, 86b, and 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 for inserting a hinge shaft 87. The hinge arms 86a, 86b protrude rearward from the left and right ends of the support plate 82, with the surfaces with the hole 89 parallel to each other. The mounting bases 83a, 83b are used to attach the aircraft frame-side connecting portion 81 to the stay 73, and are located at both ends of the support plate 82 below the hinge arms 86a, 86b, forming horizontal surfaces corresponding to the upper surfaces of the stays 73. The mounting bases 83a and 83b are provided with holes (not shown) through which mounting screws 74 are inserted, and by fastening the mounting bases 83a and 83b to the upper surface of the stay 73 with the screws, the machine frame side connecting part 81 is fixed to the swivel frame 7.

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 the coil portions 101a, 101b of the torsion coil spring 100 are inserted.

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 same is true for the right bonnet connection portion 93b and the right movable arm 96b. The connecting plate portion 92 is integrated 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.

The left and right movable arms 96a, 96b each have a hole 99 at the tip thereof that corresponds to the hole 89 in the left and right hinge arms 86a, 86b. The left and right movable arms 96a, 96b are attached to the hood 9 via hood connection parts 93a, 93b so that they are 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 around the axis of the hinge shaft 87 when the hood 9 is opened or closed.

The shaft support portion 95 includes a pair of left and right shaft support arms 97a, 97b, each having a hole at its tip end through which both ends of the support shaft 94 are inserted, and an arm support plate 98 that connects the left and right shaft support arms 97a, 97b. 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. Both ends of the support shaft 94 are fitted into the 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, for example, by bending. By fixing the arm support plate 98 to the connecting plate portion 92 with the fixing screws 76, the support shaft 94 is aligned on the same axis C as the hinge shaft 87 (see Figure 8). In other words, the support shaft 94 is aligned so that its axis is substantially aligned with the axis of the hinge shaft 87.

The aircraft frame-side connecting portion 81 and the bonnet-side connecting portion 91 are connected as follows: The coil portions 101a, 101b of the torsion coil spring 100 are inserted onto the support shaft 94 provided on the aircraft frame-side connecting portion 81, with the two arms 102a, 102b and the intermediate arm 103 facing upward, and both ends of the support shaft 94 are supported by the shaft support arms 97a, 97b. In this state, the hinge shaft 87 is inserted through the holes 89 of the aligned left and right hinge arms 86a, 86b of the aircraft frame-side connecting portion 81 and the holes 99 of the left and right movable arms 96a, 96b of the bonnet-side connecting portion 91. An insertion hole is provided at the tip of the hinge shaft 87 to insert 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 holes 89 and 99.

A pair of hinge shafts 87 are provided spaced apart in the left-right direction of the aircraft so as to correspond to the holes 89 in the left and right hinge arms 86a, 86b and the holes 99 in the left and right movable arms 96a, 96b. 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 the end of the support shaft 94, and also functions to prevent the support shaft 94 from slipping out. Therefore, the support shaft 94 does not need to be fixed to the left and right shaft support arms 97a, 97b.

In this manner, in the hinge mechanism 80 of this embodiment, the aircraft frame side connecting portion 81 and the bonnet side connecting portion 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 portion 81 and the bonnet side connecting portion 91.

The intermediate arm 103 of the torsion coil spring 100 abuts against the support plate 82 of the aircraft 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 an aircraft frame-side support 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 the 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 support portion against which the arms 102a, 102b of the torsion coil spring 100 abut. In other words, 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.

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 hood 9 from 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, causing the hood 9 to rotate 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.

The maximum open position of the hood 9 is restricted to a predetermined position (maximum open state) by a rotation stopper (not shown). In other words, 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. In other words, the torsion coil spring 100 acts within the rotation range of the hood 9 from the closed state to the maximum open state (e.g., an angle range of 70 to 80 degrees), and within the rotation range from the closed state to an intermediate rotation position (e.g., an angle range of approximately 40 degrees).

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

In this embodiment, the hinge mechanism 80 has a body frame-side connecting portion 81 and a bonnet-side connecting portion 91, and is equipped with a torsion coil spring 100 that biases the bonnet 9 to rotate upward, allowing the bonnet 9 to be flipped open by releasing the locking mechanism. By using a double torsion spring for the torsion coil spring 100, a strong biasing force can be applied to the bonnet 9, making it excellent in terms of durability.

Second Embodiment
A second embodiment of the present invention will be described with reference to Figures 9 to 13. Components common to the first embodiment are designated 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 of the upper rotating body 20A is different from that of the first embodiment.

As shown in Figures 8 to 11, in the connection portion between the bonnet 9 and the revolving frame 7 according to this embodiment, the torsion coil spring 200 used as the biasing force applying means is a so-called single torsion spring having one coil portion 201, and the coil portion 201 is inserted onto the support shaft 184 provided on the vehicle frame side connection portion 181.

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

The machine body frame side connecting portion 181 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 left and right mounting base portions 83a, 83b provided at both ends of the support plate portion 82. Each of the left and right hinge arms 86a, 86b has a hole 89 at its tip for inserting a hinge shaft 87. The machine body frame side connecting portion 181 is fixed to the revolving frame 7 by screwing each of the mounting base portions 83a, 83b to the upper surface of the stay 73. The machine body frame side connecting portion 181 also has a support shaft 184 around which the coil portion 201 of the torsion coil spring 200 is inserted, and a shaft support portion 185 that supports the support shaft 184.

The shaft support portion 185 is welded to the rearward-facing surface of the support plate portion 82 so that the support surface supporting 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. One end is connected to the shaft support portion 185 by welding, and the other end is 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 therefore aligned on the same axis C as the hinge shaft 87 (see Figure 13). In other words, the support shaft 184 is provided on the aircraft frame-side connecting portion 181 so that the axis of the support shaft 184 is approximately aligned with the axis of the hinge shaft 87. A screw hole 177 is provided on the free end of the support shaft 184, and a washer 175 is fixed to the free end with a fixing screw 176 to prevent the torsion coil spring 200 from falling off the support shaft 184.

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

The bonnet-side coupling portion 191 is fixed to the bonnet 9 by screwing the bonnet connection portions 93a and 93b to the mounting support portion 61 of the bonnet 9. Furthermore, the movable arms 96a and 96b are connected to the hinge arms 86a and 86b via the hinge shaft 87, and thus rotate around the axis of the hinge shaft 87 when the bonnet 9 is opened or closed.

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

The aircraft frame-side connecting portion 81 and the bonnet-side connecting portion 191 are connected as follows: The coil portion 201 of the torsion coil spring 200 is fitted onto the support shaft 184 provided on the aircraft frame-side connecting portion 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, the hinge shaft 87 is inserted through the holes 89 of the aligned left and right hinge arms 86a, 86b of the aircraft frame-side connecting portion 181 and the holes 99 of the left and right movable arms 96a, 96b of the bonnet-side connecting portion 91. An insertion hole is provided at the tip of the hinge shaft 87 to insert 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 holes 89 and 99.

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, thereby connecting the aircraft frame side connecting part 181 and the bonnet side connecting part 191. As a result, the torsion coil spring 200 is disposed between the aircraft frame side connecting part 181 and the bonnet side connecting part 191.

Of the two arms 202a, 202b of the torsion coil spring 200, one arm 102a abuts against the bonnet-side bearing 197 when the bonnet 9 is open or closed at an angle smaller than a predetermined angle. That is, the arm 202a receives the load of the bonnet 9 via the bonnet-side bearing 197 depending on the opening angle of the bonnet 9. Meanwhile, the other arm 202b abuts against the support plate 82 of the aircraft frame-side connecting part 81 when the bonnet 9 is open or closed at an angle smaller than a predetermined angle. The support plate 82, which the arm 202b abuts against, functions as the aircraft frame-side bearing that receives the arm 202b of the torsion coil spring 200 on the aircraft frame side.

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, which rotates the hood 9 upward, causes the hood 9 to rotate around the axis of the hinge shaft 87, and the hood 9 opens. The biasing force at this time is adjusted by the angle between the two arms 202a, 202b of the torsion coil spring 200, the number of turns of the coil portion 201, and other factors. Furthermore, like the torsion coil spring 100 in the first embodiment, the torsion coil spring 200 acts within the rotation range of the hood 9 from the closed state to the maximum open state (e.g., an angle range of 70 to 80 degrees), and within the rotation range from the closed state to an intermediate rotation position (e.g., an angle range of approximately 40 degrees).

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. This reduces the load on the bonnet 9, and allows the bonnet 9 to be easily opened by releasing the locking mechanism.

The excavation machine 1 of the first and second embodiments, which has the above-described configuration, can be said to have the following configuration: That is, the excavation machine 1 has an engine room 12 located behind the machine frame (swivel frame 7), a hood 9 covering the engine room 12, and a driver's seat 10 located above the hood 9, a hinge mechanism 80 having a machine frame-side connecting portion 81 and a hood-side connecting portion 91 and rotatably connecting the hood 9 to the machine frame (swivel frame 7), and a biasing force applying means (torsion coil springs 100, 200) located between the machine frame-side connecting portion 81 and the hood-side connecting portion 91 and applying an upward biasing force to the hood 9.

By arranging the biasing force applying means (torsion coil springs 100, 200) between the aircraft 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 maintenance technicians 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 upward, maintenance technicians can release the hood 9 locking mechanism to open the hood 9, which is connected to the revolving frame 7 by the hinge mechanism 80, with less force than conventional methods. Furthermore, when closing the hood 9, the biasing force of the biasing force applying means (torsion coil springs 100, 200) slows the closing speed of the hood 9, preventing fingers from getting pinched when the hood 9 is closed.

This configuration reduces the workload required when opening and closing the hood 9, thereby improving the maintainability of components such as the engine located in the engine room 12 inside the hood 9.

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 limiting, and other effects may also be obtained. Furthermore, the configurations of the above-described embodiments and the configurations of the variations can be combined as appropriate.

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 connecting portion 91, while in the second embodiment, the support shaft 184 is provided in the aircraft frame-side connecting portion 181. As such, as long as the torsion coil spring can be arranged between the aircraft frame-side connecting portion 81, 181 and the bonnet-side connecting portion 91, 191 of the hinge mechanism 80, the support shaft for the torsion coil spring may be supported in the bonnet-side connecting portion 91 as in the first embodiment, or in the aircraft frame-side connecting portion 181 as in the second embodiment. In this way, by providing the biasing force application means in the space inside the hinge mechanism 80, there is no need to change the layout of the equipment in the engine room 12 to provide new space for the biasing force application means, reducing the design and assembly burden.

In addition, 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 aircraft frame-side connecting portion 181 of the hinge mechanism 80, thereby streamlining the installation of the bonnet 9 to the aircraft frame (swivel frame 7).

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 of the hinge mechanism 80, thereby enabling smooth rotational movement of the hood 9.

In the first and second embodiments described above, the hinge mechanism 80 connecting 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 limited to this. The hinge mechanism 80 and biasing force applying means may be positioned interchangeably 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.

In addition, in the first and second embodiments described above, an excavator 1 is described as having a 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 also 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.

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 shaft 87.

1. Excavation machine (construction machinery)
6 Running part 7 Rotating frame (machine frame)
DESCRIPTION OF SYMBOLS 9 Bonnet 10 Driver's seat 12 Engine room 13 Work operation unit 20A Upper rotating body 20B Lower traveling body 41 Travel motor 48 Drive wheel 71 Rear wall portion 73 Stay 80 Hinge mechanism 81 Machine frame side connecting portion 82 Support plate portion 83 Mounting base portion 86 Hinge arm 87 Hinge shaft 91 Bonnet side connecting portion 93 Bonnet connection portion 94 Support shaft 95 Shaft support portion 97 Shaft support arm 100 Torsion coil spring (biasing force imparting means)
101 Coil portion 102 Arm portion 103 Intermediate arm portion 181 Machine body frame side connecting portion 184 Support shaft 185 Shaft support portion 191 Bonnet side connecting portion 200 Torsion coil spring (biasing force imparting means)
201 Coil portion 202 Arm portion

Claims (8)

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. 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 . The biasing force applying means is a torsion coil spring.
3. The construction machine according to claim 1 or 2 . 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 . 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 . 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 . 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. The construction machine according to claim 1 , wherein the hinge mechanism and the biasing force applying means are disposed rearward of the engine room.