JP2008240278A - Construction machinery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide construction machinery which can restrain a lifting and lowering device from being damaged due to settling of a grounding surface thereof, and which facilitates ascent/descent between a chassis and the ground by using the lifting and lowering device. <P>SOLUTION: A base-end side 24A of a front link 24 and a base-end side 25A of a rear link 25 are mounted in a vertically rotatable manner on the side of a lower end of a second ladder portion 17 constituting the lifting and lowering device 14, and a connection link 28 is rotatably mounted on the leading-end side 24B of the front link 24 and the leading-end side 25B of the rear link 25, so that the connection link 28 serving as a scaffold for an operator can be arranged on the downside with respect to a lowermost step 17C of the second ladder portion 17. Thus, the operator can use the connection link 28, as a first foothold, of an auxiliary lifting and lowering device 23 arranged on the downside with respect to the lowermost step 17C, and can be quickly and easily lifted and lowered between a revolving super structure 4 of a hydraulic excavator 1 and the ground G, by using the auxiliary lifting and lowering device 23 and the lifting and lowering device 14 as the footholds. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a construction machine such as a hydraulic excavator or a hydraulic crane, and more particularly to a construction machine provided with an elevating device for an operator to move up and down between a vehicle body and the ground.

  Generally, a hydraulic excavator as a representative example of a construction machine has a self-propelled vehicle body composed of a crawler-type lower traveling body and an upper revolving body that is pivotably mounted on the lower traveling body. A working device for performing excavation work or the like is provided on the front side of the upper swing body that constitutes the upper revolving structure so as to be able to move up and down. A cab (operator's cab) is usually provided on the left side of the front part of the upper swing body, and an operator operates a hydraulic excavator with an operating device housed in the cab.

  By the way, a large hydraulic excavator used for, for example, an open-pit digging operation in a mine is usually provided with an elevating device extending from the vehicle body toward the ground so that the operator can safely move up and down the upper swing body and the cab. (For example, refer to Patent Document 1).

JP 2005-83033 A

  The lifting device for a hydraulic excavator according to the prior art is connected to a first ladder portion that is pivotable upward and downward on an upper swing body, and is pivotally connected to a tip of the first ladder portion. The second ladder unit and an actuator that rotates the first ladder unit are roughly configured. Then, by rotating the first ladder portion downward by the actuator, the first and second ladder portions are linearly continuous and extend obliquely downward from the upper swing body toward the ground. As a result, the operator ascends from the ground to the upper swing body and descends from the upper swing body to the ground using the multi-steps provided in the first and second ladder portions extending from the ground to the upper swing body as scaffolds. It has a configuration that can.

  By the way, since the large-sized hydraulic excavator like the above-mentioned prior art is heavy, for example, when the ground at the work site is soft, the ground contact surface of the hydraulic excavator may sink. Therefore, when the grounding surface of the hydraulic excavator sinks with the first and second ladder portions extending from the upper swing body toward the ground, the lower end side of the lifting device (second ladder portion) is on the ground. There is a possibility that the elevating device is damaged by contacting and receiving upward force from the ground.

  On the other hand, the lifting device according to the prior art is designed so that the grounding surface of the hydraulic excavator sinks in a work site where the ground is soft, and the lower end of the lifting device is not in contact with the ground. A large interval is secured in advance. For this reason, the space | interval of the lowest step and the ground among the multistep steps provided in the lifting / lowering apparatus becomes large, and this space | interval is set to about 700 mm.

  However, if the clearance between the lower end of the lifting device and the ground is secured as described above, the lifting device can be prevented from being damaged when the grounding surface of the excavator sinks, but the lifting device can be used as a scaffold. There is a problem that when the operator enters the upper swinging body, the lowest step that the operator first puts on is at a high position, and therefore the operation of raising and lowering the lifting device is a heavy burden on the operator.

  The present invention has been made in view of the above-described problems of the prior art, suppresses breakage of the lifting device due to the ground contact surface of the construction machine sinking, and easily lifts and lowers between the vehicle body and the ground using the lifting device. It aims to provide a construction machine that can be used.

  In order to solve the above-described problems, the present invention has a self-propelled vehicle body and a multi-stage step in which the operator moves up and down, the upper end side is located above the ground and is attached to the vehicle body, and the lower end side faces the ground. The present invention is applied to a construction machine including an elevating device that extends.

  A feature of the configuration adopted by the invention of claim 1 is that the lower end side of the lifting device is attached so that the base end side is pivotable upward and downward to the lower end side of the lifting device, and the distal end side is a free end. The auxiliary lifting device is provided.

  According to a second aspect of the present invention, the elevating device is provided with a stopper that holds the auxiliary elevating device at an elevating position when the operator elevates or lowers.

  According to a third aspect of the present invention, the auxiliary lifting device includes a left and right front link whose base end side is pivotally attached to a lower end side of the lifting device, and a rear side of the front link. The left and right rear links that are pivotably attached to the lower end side of the lifting device, the left and right front links, and the left and right rear links can be pivoted. And a connecting link attached to the head.

  According to the first aspect of the present invention, by attaching the base end side of the auxiliary lifting device to the lower end side of the lifting device, the auxiliary lifting device is placed below the lowest step among the multi-steps provided in the lifting device. The tip side of the device can be placed. Thus, in consideration of the case where the ground contact surface of the construction machine sinks, even when the distance between the lowermost step provided in the lifting device and the ground is set to be large in advance, the operator can lower the lower step than the lowermost step. The tip side of the auxiliary lifting device arranged on the side can be used as the first footrest. As a result, the burden on the operator can be reduced, and the operator can quickly and easily move up and down between the vehicle body and the ground using the auxiliary lifting device and the lifting device.

  In this case, the tip end side of the auxiliary lifting device arranged below the lowermost step is a free end that can be rotated upward and downward with respect to the lower end side of the lifting device. When the auxiliary lifting device comes into contact with the ground, the tip of the auxiliary lifting device can rotate so as to escape upward, so that the auxiliary lifting device can be reliably damaged. Can be prevented.

  According to the second aspect of the present invention, the auxiliary lifting device attached to the lifting device so as to be pivotable upward and downward can be held at the lifting position by the stopper, so that the operator holds at the lifting position. By using the auxiliary lifting device and the lifting device, it is possible to easily move up and down between the vehicle body and the ground.

  According to the third aspect of the present invention, the connecting link can be attached to the lower end side of the lifting device so as to be rotatable upward and downward via the left and right front links and the left and right rear links. For this reason, the operator can move smoothly from the connection link to the lowest step of the lifting device using the connection link as a foothold.

  Hereinafter, an embodiment of the construction machine according to the present invention will be described in detail with reference to FIGS. 1 to 7 by taking as an example a case where the construction machine is applied to a large hydraulic excavator.

  Reference numeral 1 denotes a large-sized hydraulic excavator as a representative example of a construction machine. A body of the hydraulic excavator 1 turns on a self-propelled crawler type lower traveling body 2 and a swiveling device 3 on the lower traveling body 2. The upper revolving body 4 that can be mounted is generally configured. A working device (not shown) for performing excavation work or the like is provided on the front side of the upper swing body 4 so as to be able to move up and down.

  Here, the upper swing body 4 includes a swing frame 5 that forms a support structure, a high-cab specification cab 7 provided on the left side of the front portion of the swing frame 5 via a cab bed 6, and a rear portion of the swing frame 5. A counterweight 8 provided to balance the weight with the work device and a building 9 provided on the revolving frame 5 on the front side of the counterweight 8 are roughly configured. The building 9 is a machine room, in which various mounted devices such as an engine, a hydraulic pump, a radiator, an oil cooler, a fuel tank, a hydraulic oil tank (not shown) are accommodated. Yes.

  Reference numeral 10 denotes a left side walk provided on the left side surface of the turning frame 5, and the left side walk 10 forms a passage for the operator. The left side walk 10 extends forward and rearward from the cab bed 6 to the counterweight 8, and a support base 10 </ b> A that supports a lifting device 14 described later is provided on the front side of the left side walk 10. ing. On the other hand, 11 is a right side walk provided on the right side surface of the revolving frame 5, and the right side walk 11 extends forward and backward from the cab bed 6 to the counterweight 8 to form an operator passage. It is.

  A catwalk 12 is provided so as to surround the periphery of the cab 7, and the catwalk 12 forms a passage when an operator gets on and off the cab 7. A stepped step 13 is provided between the left side walk 10 and the catwalk 12, and the stepped step 13 extends obliquely upward from the left sidewalk 10 toward the catwalk 12. The operator moves from the left side walk 10 to the catwalk 12 or the upper surface side of the building 9 using the stepped step 13 as a scaffold.

  14 is a foldable lifting device attached to the support base 10A of the left side walk 10. The lifting device 14 is attached to the support base 10A whose upper end side is above the ground G, and its lower end side is directed to the ground G. It extends. And the raising / lowering apparatus 14 forms the scaffold for an operator to raise / lower safely between the left side walk 10 with a large ground height, and the ground G, The 1st ladder part 15 mentioned later, 2nd It is comprised by the ladder part 17, the hydraulic cylinder 19, etc.

  15 is a first ladder portion attached to the support base 10A of the left side walk 10, and the first ladder portion 15 is facing up in the left and right directions as shown in FIGS. A left and right side plate 15A (only the left side is shown) extending downward, and a multi-step step 15B, 15B,... Fixed between the left and right side plates 15A with a certain interval in the upward and downward directions. It is configured. Further, in the vicinity of the left and right side plates 15A, left and right handrails 15C (only the left side are shown) fixed to a plurality of steps 15B are provided.

  Here, the upper end side of the first ladder portion 15 is attached to the support base 10A of the left side walk 10 on the upper side of the ground G through the support pins 16 so as to be rotatable upward and downward. . Further, a second ladder portion 17 described later is rotatably attached to the lower end side of the first ladder portion 15.

  Reference numeral 17 denotes a second ladder part rotatably attached to the lower end side of the first ladder part 15 via a connecting pin 18, and the second ladder part 17 is formed as shown in FIGS. The left and right side plates 17A and 17A extending in the upward and downward directions while facing the left and right directions, and the multi-steps 17B fixed between the left and right side plates 17A with a certain distance in the upward and downward directions, 17B,..., And a bottom plate 17D that is disposed below the lowermost step 17C of the multi-steps 17B and connects the lower end portions of the left and right side plates 17A. Further, in the vicinity of the left and right side plates 17A, left and right handrails 17E fixed to a plurality of steps 17B and a lowermost step 17C are provided.

  The upper end side of the second ladder portion 17 is connected to the lower end side of the first ladder portion 15 via a connecting pin 18 so as to be rotatable upward and downward. Further, an auxiliary lifting device 23 described later is provided on the lower end side of the second ladder portion 17.

  Reference numeral 19 denotes a hydraulic cylinder provided between the support base 10A of the left side walk 10 and the first ladder portion 15, and the hydraulic cylinder 19 is arranged with the first ladder portion 15 as an upper portion with the support pin 16 as a rotation fulcrum. , Rotate downward. Here, the base end side (bottom side) of the hydraulic cylinder 19 is pin-coupled to the support base 10A below the support pin 16 so as to be rotatable, and the tip end side (rod side) of the hydraulic cylinder 19 is the first side. The ladder portion 15 is pin-coupled to the intermediate portion in the length direction so as to be rotatable.

  Reference numeral 20 denotes a triangular arm provided on the front end side of the first ladder portion 15, and the arm 20 has three corner portions 20A, 20B, and 20C. The corner portion 20A of the arm 20 is pivotally connected to the distal end side of the first ladder portion 15, and the corner portion 20B of the arm 20 is connected to the base end of the second ladder portion 17 via the lever 21. It is connected to the side. Further, the corner portion 20C of the arm 20 is pivotally connected to the tip end portion of the rod 22, and the base end portion of the rod 22 is pivotally connected to the support base 10A.

  Therefore, when the hydraulic cylinder 19 is contracted as shown in FIG. 3, the first ladder portion 15 extends obliquely downward from the support base 10A toward the ground G with the support pin 16 as a fulcrum, and the second ladder portion 17 Is configured to extend obliquely downward continuously from the lower end side of the first ladder portion 15 by the action of the arm 20, the lever 21, the rod 22, and the like. As described above, when the hydraulic cylinder 19 is contracted, the first and second ladder portions 15 and 17 are in the extended posture extending obliquely downward from the support base 10A toward the ground G. Each step 17B of the ladder unit 17 and each step 15B of the first ladder unit 15 can be used as a scaffold to rise from the ground G to the left sidewalk 10 and to descend from the left sidewalk 10 to the ground G.

  In this case, when the ground G at the work site is weak, the first and second ladder portions 15 and 17 are considered in consideration that the ground contact surface of the hydraulic excavator 1 sinks due to the weight of the hydraulic excavator 1. Is in the extended posture, the distance (height) H between the upper surface of the lowermost step 17C provided on the second ladder portion 17 and the ground G is set to about 700 mm, for example (see FIG. 5). ).

  On the other hand, when the hydraulic cylinder 19 is extended as shown in FIG. 4, the first ladder portion 15 rises substantially vertically upward from the support base 10 </ b> A with the support pin 16 as a fulcrum, and the second ladder portion 17 has the arm 20. The lever 21 and the rod 22 are folded so as to approach the first ladder portion 15 with the connecting pin 18 as a fulcrum. As described above, when the hydraulic cylinder 19 is extended, the first and second ladder portions 15 and 17 are folded and stored compactly on the support base 10A.

  Reference numeral 23 denotes an auxiliary lifting device additionally provided at the lower end side of the second ladder unit 17, which is configured by the lowermost step 17 </ b> C and the ground G of the lifting device 14 (second ladder unit 17). Between them, an auxiliary operator's scaffolding is formed. Here, as shown in FIGS. 5 to 7, the auxiliary lifting device 23 is roughly configured by left and right front links 24 and 24, left and right rear links 25 and 25, and a connection link 28, which will be described later. Has been.

  Reference numerals 24 and 24 denote a pair of left and right front links constituting the auxiliary lifting device 23. The left and right front links 24 are formed in a strip shape using a steel plate material or the like. Then, the base end side (upper end side) 24A of the left and right front links 24 can be rotated via a pin 26 to the front lower end side of the left and right side plates 17A constituting the second ladder portion 17. Pin-coupled. Thereby, the front end side (lower end side) 24B of the left and right front links 24 is a free end that can rotate upward and downward with the pin 26 as a rotation fulcrum with respect to the left and right side plates 17A. .

  Reference numerals 25 and 25 denote a pair of left and right rear links arranged on the rear side of the above-described front link 24. These left and right rear links 25 are also formed in an elongated strip shape using a steel plate material or the like. The base end side (upper end side) 25 </ b> A of the left and right rear links 25 is configured to be rotatable via a pin 27 to the rear lower end side of the left and right side plates 17 </ b> A constituting the second ladder portion 17. Are combined. Thereby, the front end side (lower end side) 25B of the left and right rear links 25 is a free end that can rotate upward and downward with the pin 27 as a rotation fulcrum with respect to the left and right side plates 17A. .

  Reference numeral 28 denotes a connecting link rotatably attached to the front end side 24B of the left and right front links 24 and the front end side 25B of the left and right rear links 25. The connecting link 28 is a second ladder portion 17. It is arranged below the lowermost step 17C provided in the, and constitutes an auxiliary scaffold for the operator. Here, the connecting link 28 is formed in a rectangular frame shape by a front connecting portion 28A, a rear connecting portion 28B, a left connecting portion 28C, and a right connecting portion 28D, and these connecting portions 28A, 28B, 28C, On the upper end side of 28D, a mesh-shaped tread surface 28E that the operator steps on is fixedly provided.

  The front end side 24B of the left and right front links 24 is pin-coupled to the front end side of the left connecting portion 28C and the right connecting portion 28D of the connecting link 28 using a pin 29 so as to be rotatable. Further, the front end side 25B of the left and right rear links 25 are pin-coupled to the rear end sides of the left connecting portion 28C and the right connecting portion 28D of the connecting link 28 using a pin 30 so as to be rotatable.

  Therefore, by rotating the front link 24 and the rear link 25 upward and downward with the pins 26 and 27 as fulcrums with respect to the left and right side plates 17A of the second ladder portion 17, the connecting link 28 is As shown in FIG. 5, it is configured to rotate upward and downward between an elevation position when the operator ascends and descends and a retracted position where the operator comes into contact with the bottom plate 17D of the second ladder portion 17 as shown in FIG. . The distance (height) h between the tread surface 28E of the connection link 28 and the ground G in the state where the connection link 28 holds the lifted position is easily adjusted by the operator on the ground G to the tread surface 28E of the connection link 28. Is set to a height, for example, about 300 mm.

  In this case, the left and right front links 24 and the left and right rear links 25 are formed to have substantially the same length, and the parallel link between the lower end side of the second ladder portion 17 and the connecting link 28. Is configured. As a result, the tread surface 28E of the connecting link 28 can always maintain a substantially parallel posture with respect to the lowermost step 17C provided on the second ladder portion 17, and the connecting link 28 has the lifted position shown in FIG. Then, the operator can step from the tread 28E of the connecting link 28 to the lowermost step 17C without a sense of incongruity.

  31 and 31 are left and right stoppers provided on the lower end side of the left and right side plates 17A constituting the second ladder portion 17, and each stopper 31 connects the connecting link 28 of the auxiliary lifting device 23 to the operator. It is held in the lift position when it is lifted. Here, the stopper 31 is formed of, for example, a small block, and is fixed to a position near the pin 27 on the outer surface of the left and right side plates 17A by means of welding or the like. Then, as shown in FIG. 5, the rear link 25 that rotates upward and downward with the pin 27 as a fulcrum is brought into contact with the stopper 31, whereby the connecting link 28 of the auxiliary lifting device 23 is held in the lifted position. It has a configuration.

  Therefore, the auxiliary lifting device 23 always maintains the lifting position shown in FIG. 5 by the rear link 25 coming into contact with the stopper 31 by its own weight. On the other hand, as shown in FIG. 6, for example, when the ground contact surface of the hydraulic excavator 1 sinks on the soft ground G ′ and the auxiliary lifting device 23 contacts the soft ground G ′, the front link 24 and the rear The link 25 rotates upward with the pins 26 and 27 as fulcrums. Thus, the auxiliary lifting device 23 is configured to be able to escape to the retracted position where the connecting link 28 contacts the bottom plate 17D of the second ladder portion 17.

  The hydraulic excavator 1 according to the present embodiment has the above-described configuration. When excavation work such as earth and sand is performed using the hydraulic excavator 1, the hydraulic cylinder 19 of the elevating device 14 is extended to be shown in FIG. As shown, the first ladder portion 15 and the second ladder portion 17 can be folded in a compact manner and stored on the support base 10 </ b> A of the left sidewalk 10.

  As described above, the hydraulic excavator 1 turns the upper swing body 3 while turning the upper swing body 3 in a state where the first and second ladder portions 15 and 17 are folded and stored on the support base 10A of the left side walk 10. Excavation work of earth and sand is performed using (not shown).

  On the other hand, when the operator moves up and down between the excavator 1 and the ground G, first, the hydraulic cylinder 19 of the elevating device 14 is contracted, so that the first and second ladders as shown in FIGS. The portions 15 and 17 are in an extended posture extending obliquely downward from the support base 10A of the left side walk 10 toward the ground G.

  At this time, as shown in FIG. 5, the auxiliary lifting device 23 attached to the lower end side of the second ladder portion 17 causes the rear link 25 to come into contact with the stopper 31, so that the connecting link 28 is the lowermost step 17 </ b> C. The raising / lowering position arrange | positioned below is hold | maintained. As a result, the operator who gets into the excavator 1 from the ground G can easily step to the step 17 </ b> C at the lowest stage of the second ladder portion 17 using the tread surface 28 </ b> E of the connection link 28 as the first footrest. As a result, the burden on the operator can be reduced as compared with the case where the lowest step 17C of the second ladder portion 17 is used as the first step, and the operator uses the auxiliary lifting device 23 and the lifting device 14. Thus, the hydraulic excavator 1 can be moved up and down quickly and easily between the ground.

  On the other hand, as shown in FIG. 6, for example, when the ground contact surface of the excavator 1 sinks on the soft ground G ′, the auxiliary lifting device 23 comes into contact with the soft ground G ′. In this case, the front link 24 and the rear link 25 rotate upward with the pins 26 and 27 as fulcrums, so that the auxiliary lifting device 23 has the connection link 28 abutting against the bottom plate 17D of the second ladder portion 17. It rotates to escape to the retreat position. As a result, it is possible to prevent an excessive force from acting on the auxiliary lifting device 23 from the ground G ′, and it is possible to protect the auxiliary lifting device 23.

  Thus, according to the present embodiment, the base end side 24A of the left and right front links 24 and the base end of the left and right rear links 25 are arranged on the lower end side of the second ladder portion 17 constituting the lifting device 14. The left and right front links 24 are attached to the front end side 24B of the left and right front links 24 and the left and right rear links 25 are attached to the front end side 25B of the left and right rear links 25 so as to be rotatable. Thus, the connecting link 28 serving as the scaffolding for the operator is arranged below the lowermost step 17C provided in the second ladder portion 17.

  Thereby, in consideration of the case where the ground contact surface of the excavator 1 has sunk, the distance (height) H between the lowermost step 17C provided on the second ladder portion 17 and the ground G is set large in advance. However, the operator can use the connecting link 28 (the tread surface 28E) of the auxiliary lifting device 23 disposed below the lowermost step 17C as the first footrest. As a result, the burden on the operator can be reduced compared with the case where the lowermost step 17C of the second ladder portion 17 is used as a first step, and the operator can connect the auxiliary lifting device 23 and the lifting device 14 to each other. As a scaffold, it is possible to quickly and easily move up and down between the upper swing body 4 of the excavator 1 and the ground G.

  Moreover, even if the auxiliary lifting device 23 comes into contact with the soft ground G ′ due to the ground contact surface of the hydraulic excavator 1 sinking on the soft ground G ′, as shown in FIG. As the link 25 pivots upward with the pins 26 and 27 as fulcrums, the connecting link 28 can escape to the retracted position where it abuts against the bottom plate 17D of the second ladder section 17. As a result, it is possible to prevent the auxiliary lifting device 23 from being damaged by receiving an excessive force from the ground G ′ and to protect the auxiliary lifting device 23.

  Further, the left and right front links 24 and the left and right rear links 25 constituting the auxiliary lifting device 23 are formed between the lower end side of the second ladder portion 17 (the left and right side plates 17A) and the connecting link 28. Since the parallel links are formed, the tread surface 28E of the connecting link 28 can always maintain a substantially parallel posture with respect to the lowermost step 17C provided in the second ladder portion 17. Thereby, when the auxiliary lifting device 23 is in the lifting position shown in FIG. 5, the operator can step from the tread surface 28E of the connecting link 28 arranged in parallel to each other to the lowermost step 17C without a sense of incongruity. Therefore, the auxiliary elevator device 23 and the elevator device 14 can be used to quickly and safely move between the upper swing body 4 of the excavator 1 and the ground G.

  In the above-described embodiment, the one-stage connecting link 28 is attached to the front end side 24B of the left and right front links 24 and the front end side 25B of the left and right rear links 25 constituting the auxiliary lifting device 23. The case is shown as an example. However, the present invention is not limited to this, and for example, a configuration in which two or more connecting links are attached may be adopted.

  Moreover, in embodiment mentioned above, the folding type raising / lowering apparatus 14 comprised by the 1st ladder part 15 and the 2nd ladder part 17 was mentioned as an example, and the 2nd ladder part which comprises this raising / lowering apparatus 14 is mentioned. The case where the auxiliary raising / lowering apparatus 23 is provided in the lower end side of 17 is illustrated. However, the present invention is not limited to this. For example, a non-folding lifting device that always extends linearly from the upper swing body 4 toward the ground G is provided, and an auxiliary lifting device is provided on the lower end side of the non-folding lifting device. The apparatus 23 may be provided.

  Furthermore, in embodiment mentioned above, the large sized hydraulic shovel 1 is illustrated as a construction machine provided with the raising / lowering apparatus 14 grade | etc.,. However, the present invention is not limited to this, and can be widely applied to other construction machines in which the ground height of a cab such as a hydraulic crane used for cargo handling work in a harbor or the like is large.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing a hydraulic excavator according to an embodiment of the present invention with a working device removed. It is the left view which looked at the hydraulic shovel from the arrow II-II direction in FIG. It is an enlarged front view which expands and shows the raising / lowering apparatus, auxiliary | assistant raising / lowering apparatus, etc. in FIG. FIG. 4 is an enlarged front view similar to FIG. 3, showing a state where the lifting device is in a folded posture. It is a principal part enlarged view which shows the state which the auxiliary raising / lowering apparatus in FIG. 3 was in the raising / lowering position. It is a principal part enlarged view similar to FIG. 5 which shows the state which the auxiliary raising / lowering apparatus became a retracted position. It is a partially broken perspective view showing a lifting device and an auxiliary lifting device.

Explanation of symbols

1 Hydraulic excavator 2 Lower traveling body (vehicle body)
4 Upper swing body (car body)
DESCRIPTION OF SYMBOLS 14 Lifting device 15 1st ladder part 15B, 17B Step 17 2nd ladder part 17C Bottom step 23 Auxiliary lifting device 24 Front link 24A, 25A Base end side 24B, 25B Tip side 25 Rear link 28 Connection link 31 Stopper

Claims (3)

In a construction machine comprising a self-propelled vehicle body, and a multi-stage step that an operator moves up and down, and an elevator device that is attached to the vehicle body with an upper end side above the ground and that has a lower end side that extends toward the ground. ,
The lower end side of the elevating device is provided with an auxiliary elevating device in which the base end side is attached to the lower end side of the elevating device so as to be rotatable upward and downward, and the distal end side is a free end. Construction machinery.   The construction machine according to claim 1, wherein the lifting device is provided with a stopper that holds the auxiliary lifting device at a lifting position when the operator lifts and lowers the auxiliary lifting device.   The auxiliary lifting device includes a left and right front link whose base end side is rotatably attached to a lower end side of the lifting device, and a rear end side of the front link and a base end side of the lower end of the lifting device. Left and right rear links pivotably attached to the side, and connecting links pivotally attached to the front end side of the left and right front links and the front end side of the left and right rear links The construction machine according to claim 1 or 2, comprising:

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