JP2022133008A - Construction machine - Google Patents

Abstract

To provide a construction machine improved in workability when drawing/inserting a connection pin out of/to an arm and an arm cylinder.SOLUTION: A work device 7 of a hydraulic shovel 1 has a boom 8 rotating in relation to an upper revolving body 3 by a boom cylinder 14, an arm 11 rotating in relation to the boom 8 by an arm cylinder 16, and a work tool mounted at a tip of the arm 11. One end of the arm cylinder 16 is rotatably connected to the boom 8, and the other end is rotatably connected to a pin hole 11C of the arm 11 by using a pin. Between the boom 8 and the arm cylinder 16, a jack 18 is provided which positions a pin hole 16C of a rod 16B side of the arm cylinder 16 to the pin hole 11C of the arm 11, by derricking the arm cylinder 16 in relation to the boom 8.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a construction machine including a self-propellable vehicle body and a working device operated by a hydraulic cylinder.

Hydraulic excavators, which represent construction machinery, have a body composed of a self-propelled lower traveling body and an upper revolving body rotatably mounted on the lower traveling body. is provided. When dismantling a structure having a large height above the ground, such as a high-rise building, a working device for dismantling work is attached to the front portion of the upper revolving structure.

A working device for demolition work is usually a boom ( multi-boom). An arm is rotatably connected to the tip of the front boom, and a working tool such as a crusher is attached to the tip of the arm. A boom cylinder is provided between the swing frame and the main boom, and a jib cylinder is provided between the main boom and the front boom. An arm cylinder is provided between the front boom and the arm, and a work tool cylinder is provided between the arm and the work tool.

By the way, when transporting a hydraulic excavator for demolition work to a work site, the excavator is usually divided into a vehicle body and a working device, and the vehicle body and the working device are loaded on separate vehicles and individually transported to the work site. transport to Since the work equipment for demolition work is long, usually, the arm and the boom to which the base end of the arm cylinder is attached are separated from the work site with the arm removed from the boom and the tip of the arm cylinder removed from the arm. transport to At the work site, the boom of the working device is attached to the vehicle body, the arm is attached to the tip of the boom, and the tip of the arm cylinder is attached to the arm.

Thus, when assembling the arm and the boom to which the base end of the arm cylinder is attached at the work site, for example, the arm is connected to the tip of the boom using a pin while the arm cylinder is temporarily fixed to the boom. . Then, the boom cylinder is used to lift the boom to adjust the angle with the arm, and the arm cylinder is extended. As a result, the pin hole at the tip of the arm cylinder (piston rod) temporarily fixed to the boom is aligned with the pin hole provided in the arm, and the tip of the arm cylinder is moved by inserting the pin through each of these pin holes. It can be rotatably connected to the arm (Patent Document 1).

JP 2009-263995 A

However, in the hydraulic excavator according to Patent Document 1, when the tip of the arm cylinder is connected to the arm using a pin at the work site, the operator must guide the boom hoisting motion and the extension motion of the arm cylinder by the boom cylinder. must be carried out in parallel under the direction of the Therefore, there is a problem that the burden on the operator is increased. Furthermore, since the position of the pin hole on the arm side becomes higher when the boom is raised, the work of inserting the heavy pin through the pin hole on the arm side and the pin hole at the tip of the arm cylinder becomes a high place work, resulting in assembly. There is a problem that the workability of the work is lowered.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a construction machine capable of enhancing workability when inserting and withdrawing a connecting pin between an arm and an arm cylinder.

The present invention comprises a self-propellable vehicle body and a working device provided on the vehicle body, wherein the working device comprises a boom whose base end is attached to the vehicle body and which rotates with respect to the vehicle body by a boom cylinder; An arm whose base end side is attached to the tip of the boom and rotates with respect to the boom by an arm cylinder, and a working tool attached to the tip of the arm, wherein one end of the arm cylinder rotates to the boom In the construction machine, the other end of which is rotatably connected to the cylinder connecting portion of the arm using a pin, the arm cylinder is connected to the boom between the boom and the arm cylinder. A jack is provided for aligning the other end of the arm cylinder with the cylinder connecting portion of the arm by raising and lowering the arm cylinder.

According to the present invention, by raising and lowering the arm cylinder with respect to the boom by means of a jack, the position of the other end of the arm cylinder with respect to the cylinder connecting portion of the arm can be finely adjusted for accurate alignment. As a result, it is possible to improve workability when connecting the arm and the arm cylinder at a work site or the like.

1 is a left side view showing a hydraulic excavator for demolition work to which an embodiment of the present invention is applied; FIG. FIG. 5 is a left side view showing the operation of connecting the tip of the arm cylinder to the arm supported by the arm support; It is a left view which shows the state which connected the front-end|tip of the arm cylinder with the arm. FIG. 3 is an enlarged view of a main part of a jack or the like in FIG. 2; FIG. 5 is a cross-sectional view of the jack, arm cylinder, front boom, etc. viewed in the direction of arrows VV in FIG. 4; 4 is a left side view showing an enlarged VI section in FIG. 3; FIG. FIG. 7 is an enlarged view of a main part, enlarging a jack or the like in FIG. 6;

An embodiment of a construction machine according to the present invention will now be described in detail with reference to the accompanying drawings, taking as an example a case where it is applied to a hydraulic excavator for demolition work. In the embodiments, the traveling direction of the hydraulic excavator is defined as the front-rear direction, and the direction perpendicular to the traveling direction is defined as the left-right direction.

A hydraulic excavator 1 for demolition work includes a self-propelled crawler-type lower traveling body 2, an upper revolving body 3 rotatably mounted on the lower traveling body 2, and an upper revolving body 3 provided on the front side of the upper revolving body 3. A multi-boom work device 7 is included. The lower traveling body 2 and the upper revolving body 3 constitute the vehicle body of the hydraulic excavator 1 . The hydraulic excavator 1 is suitably used for demolition work of demolishing a structure having a large height above the ground, such as a high-rise building.

The upper revolving body 3 includes a revolving frame 4 as a base, a counterweight 4A provided on the rear end side of the revolving frame 4, a cab 5 arranged on the front left side of the revolving frame 4, and a front side of the counterweight 4A. It is configured including a building cover 6 arranged in. The cab 5 defines a cab for an operator to operate the hydraulic excavator 1. Inside the cab 5 are a travel lever/pedal device for controlling the travel motion of the lower travel body 2, the revolving motion of the upper revolving body 3, An operating lever device (none of which is shown) is provided for controlling the operation of the working device 7 . Mounted equipment (not shown) such as an engine, a hydraulic pump, and a heat exchanger are housed inside the building cover 6 .

A support bracket (not shown) that rises upward from the bottom plate is integrally provided on the front end side of the revolving frame 4 . The support bracket rotatably supports the base end side of a lower boom 9A, which will be described later, and also rotatably supports the base end side of the boom cylinder 14 .

A multi-boom work device 7 is attached to the front end of a revolving frame 4 that constitutes the upper revolving body 3 . The working device 7 includes a boom 8 consisting of a main boom 9 and a front boom 10, an arm 11, and a crusher 12 as a working tool. The main boom 9 consists of a lower boom 9A and an upper boom 9B, and the base end of the lower boom 9A is rotatably attached to the front end of the revolving frame 4 (the support bracket). The base end side of the front boom 10 is rotatably connected to the tip of the upper boom 9B via a pin 10A. The base end of the arm 11 is rotatably connected to the tip of the front boom 10 using a pin 11A. The crusher 12 is rotatably connected to the tip of the arm 11 using a pin 12A.

Here, the front boom 10 includes a left side plate 10B and a right side plate 10C facing each other in the horizontal direction at a constant interval, a rear plate 10D connecting the upper ends of the left and right side plates 10B and 10C, and a rear plate 10D in the vertical direction. It is formed as a box body having a rectangular cross section surrounded by a bottom plate 10E that connects the lower ends of the left and right side plates 10B and 10C. An upper cylinder bracket 10F protruding upward from a rear plate 10D is provided on the base end side of the front boom 10, and the bottom side of an arm cylinder 16 is rotatably connected to the upper cylinder bracket 10F. A lower cylinder bracket 10G protruding downward from the lower plate 10E is provided at the intermediate portion of the front boom 10 in the length direction, and the rod side of the jib cylinder 15 is rotatably connected to the lower cylinder bracket 10G.

A boom-side jack fixing plate 10H is provided at an intermediate portion of the front boom 10 in the longitudinal direction. The boom-side jack fixing plate 10H is made of a flat steel plate and fixed to the back plate 10D of the front boom 10 by welding or the like (see FIGS. 4 and 5). A boom-side base member 19 of a jack 18, which will be described later, is fixed to the boom-side jack fixing plate 10H. Further, the rear plate 10D of the front boom 10 is provided with a jack fixture 28, which will be described later, adjacent to the boom-side jack fixing plate 10H.

The arm 11 is formed as a box body with a square cross section similar to the front boom 10 . A cylinder bracket 11B is provided at the base end of the arm 11, and a pin hole 11C as a cylinder connecting portion is formed in the cylinder bracket 11B (see FIG. 2).

The crusher 12 for demolition work has left and right claw members 12B that are opened and closed by a hydraulic cylinder. transport to A bracket 12C is provided on the base end side of the crusher 12, and the bracket 12C is connected to the tip of the arm 11 using a pin 12A. A bucket link 13 is provided between the bracket 12C and the arm 11, and a rod side of a work implement cylinder 17, which will be described later, is connected to an intermediate portion of the bucket link 13. As shown in FIG.

A pair of left and right boom cylinders 14 (two) are provided between the revolving frame 4 and the lower boom 9A (only the left side is shown). The bottom side of the boom cylinder 14 is rotatably attached to the support bracket of the revolving frame 4 . The rod side of the boom cylinder 14 is rotatably connected to the tip side of the lower boom 9A using a pin 14A. A jib cylinder 15 is provided between the upper boom 9B and the front boom 10 . The bottom side of the jib cylinder 15 is rotatably connected to the upper boom 9B using a pin 15A, and the rod side of the jib cylinder 15 is rotatably connected to the lower cylinder bracket 10G of the front boom 10 using a pin 15B. there is

Arm cylinder 16 is provided between front boom 10 and arm 11 . The arm cylinder 16 has a tube 16A, a piston (not shown) slidably provided in the tube 16A, and a rod 16B having a proximal end attached to the piston and a distal end protruding from the tube 16A. A pin hole 16C is formed at the tip of 16B (see FIG. 2). A bottom side, which is one end of the arm cylinder 16 (tube 16A), is rotatably connected to the upper cylinder bracket 10F of the front boom 10 using a pin 16D. The tip of the rod 16B, which is the other end of the arm cylinder 16, is rotatably connected to the cylinder bracket 11B of the arm 11 using a pin 16E.

A cylinder-side jack fixing plate 16F is provided at a portion of the outer peripheral surface of the arm cylinder 16 (tube 16A) that faces the rear plate 10D of the front boom 10 . The cylinder-side jack fixing plate 16F is made of a flat steel plate and is fixed to the outer peripheral surface of the tube 16A by means of welding or the like (see FIGS. 4 and 5). Four bolt insertion holes 16G penetrating in the plate thickness direction are formed at the four corners of the cylinder-side jack fixing plate 16F.

A work implement cylinder 17 is provided between the arm 11 and the bucket link 13 . The bottom side of the work implement cylinder 17 is rotatably connected to the arm 11 using a pin 17A, and the rod side of the work implement cylinder 17 is rotatably connected to the intermediate portion of the bucket link 13 using a pin 17B. It is

The main boom 9 is vertically rotated with respect to the revolving frame 4 by extending and retracting the boom cylinder 14, and the front boom 10 is vertically rotated with respect to the main boom 9 with the pin 10A as a fulcrum by extending and retracting the jib cylinder 15. Rotate vertically. By extending and retracting the arm cylinder 16, the arm 11 rotates vertically with respect to the front boom 10 with the pin 11A as a fulcrum. , and rotates vertically with respect to the arm 11 .

Next, the jack 18 provided between the front boom 10 and the arm cylinder 16 will be described.

The jack 18 is provided between the back plate 10</b>D of the front boom 10 and the arm cylinder 16 . The jack 18 is a state in which the bottom side of the arm cylinder 16 (tube 16A) is connected to the front boom 10 (upper cylinder bracket 10F) via a pin 16D, and the rod 16B side of the arm cylinder 16 is used as a fulcrum to move the front boom. Raise against 10. Thereby, the jack 18 aligns the pin hole 16C provided at the tip of the rod 16B of the arm cylinder 16 with the pin hole 11C provided in the cylinder bracket 11B of the arm 11 (see FIG. 2). As shown in FIGS. 4 and 5, the jack 18 includes a boom side base member 19, a cylinder side base member 21, boom side arms 23A and 23B, cylinder side arms 24A and 24B, a first connecting member 25 and a second connecting member. 26, a screw shaft 27, etc., and is configured as a manually operated jack.

The boom-side base member 19 constitutes one end of the jack 18 in the extension/retraction direction. The boom-side base member 19 is provided at a position corresponding to the boom-side jack fixing plate 10H fixed to the rear plate 10D of the front boom 10. As shown in FIG. The boom-side base member 19 includes a base plate 19A having the same rectangular shape as the boom-side jack fixing plate 10H, and a pair (two) of arm support plates 19B protruding from the upper surface of the base plate 19A with a constant interval. is composed of The base plate 19A is connected to the boom-side jack fixing plate 10H of the front boom 10 via a hinge mechanism 20. As shown in FIG.

The hinge mechanism 20 connects between the boom-side jack fixing plate 10H of the front boom 10 and the boom-side base member 19 of the jack 18 . The hinge mechanism 20 has two rotating pieces 20A and 20B that rotate relative to each other about a rotating shaft. The moving piece 20B is fixed to the end face of the boom-side base member 19. As shown in FIG. Therefore, the boom-side base member 19 is pivotally displaced around the hinge mechanism 20 with respect to the boom-side jack fixing plate 10H.

As shown in FIG. 4, when the boom-side base member 19 is superimposed on the upper surface of the boom-side jack fixing plate 10H, the jack 18 is raised from the boom-side jack fixing plate 10H to the arm cylinder 16 side. position. On the other hand, as indicated by the solid line in FIG. 7, when the boom-side base member 19 separates from the upper surface of the boom-side jack fixing plate 10H with the hinge mechanism 20 as a fulcrum, the jack 18 moves toward the back plate 10D of the front boom 10. It is in the stowed position when folded.

The cylinder-side base member 21 constitutes the other end of the jack 18 in the extension/contraction direction. The cylinder-side base member 21 is detachably fixed to a cylinder-side jack fixing plate 16F fixed to the tube 16A of the arm cylinder 16 using a plurality of bolts 22 as fasteners. The cylinder-side base member 21 includes a base plate 21A having the same square shape as the cylinder-side jack fixing plate 16F, and a pair (two) of arm support plates 21B protruding from the lower surface of the base plate 21A with a constant interval. is composed of Four bolt insertion holes 21C corresponding to the bolt insertion holes 16G of the cylinder-side jack fixing plate 16F are formed at the four corners of the base plate 21A. Four nuts 21D corresponding to the four bolt insertion holes are welded to the lower surface of the base plate 21A. Therefore, by screwing four bolts 22 inserted through the bolt insertion holes 16G of the cylinder-side jack fixing plate 16F to the nuts 21D of the base plate 21A, the cylinder-side base member 21 can be attached to the cylinder-side jack fixing plate 16F. It is superimposed and fixed on the bottom surface of the .

The boom side arm 23A is provided between the boom side base member 19 and the first connecting member 25, and the boom side arm 23B is provided between the boom side base member 19 and the second connecting member . One end of the boom side arm 23A is rotatably connected to the arm support plate 19B of the boom side base member 19 via a pin 23C, and the other end is rotatably connected to the first connecting member 25 via a pin 23D. It is One end of the boom-side arm 23B is rotatably connected to the arm support plate 19B of the boom-side base member 19 using a pin 23E, and the other end is rotatably connected to the second connecting member 26 using a pin 23F. It is

The cylinder-side arm 24A is provided between the cylinder-side base member 21 and the first connecting member 25, and the cylinder-side arm 24B is provided between the cylinder-side base member 21 and the second connecting member . One end of the cylinder-side arm 24A is rotatably connected to the arm support plate 21B of the cylinder-side base member 21 via a pin 24C, and the other end is rotatably connected to the first connecting member 25 via a pin 24D. It is One end of the cylinder-side arm 24B is rotatably connected to the arm support plate 21B of the cylinder-side base member 21 via a pin 24E, and the other end is rotatably connected to the second connecting member 26 via a pin 24F. It is

The first connecting member 25 is provided between the boom side base member 19 and the cylinder side base member 21, and connects between the other end of the boom side arm 23A and the other end of the cylinder side arm 24A. The first connecting member 25 rotatably supports one end of the screw shaft 27 while restricting movement in the axial direction.

The second connecting member 26 is arranged between the boom side base member 19 and the cylinder side base member 21 while being aligned with the first connecting member 25 in the left-right direction, and the other end of the boom side arm 23B and the cylinder side arm 24B. and the other end of the A screw hole (female screw) 26A into which the screw shaft 27 is screwed is formed through the second connecting member 26 in the left-right direction.

The screw shaft 27 is provided so as to pass through the first connecting member 25 and the second connecting member 26 . One end side of the screw shaft 27 in the length direction is rotatably supported by the first connecting member 25 while its axial movement is restricted. On the other hand, the other end side of the screw shaft 27 is screwed into the screw hole 26A of the second connecting member 26. As shown in FIG. Further, one end of the screw shaft 27 serves as an operating portion 27A protruding from the first connecting member 25 in the axial direction. The operation portion 27A is formed in a polygonal prism shape such as a quadrangle or a hexagon so that a screw tightening tool (not shown) such as an impact wrench can be connected.

Therefore, by connecting a screw tightening tool to the operation portion 27A and rotating the screw shaft 27, the distance between the first connecting member 25 and the second connecting member 26 can be changed, and the jack 18 can be extended and contracted. As a result, the cylinder-side base member 21 of the jack 18 is moved toward and away from the boom-side base member 19, and the arm cylinder 16 is raised and lowered using the pin 16D, which is the connecting portion with the front boom 10, as a fulcrum. It is configured to allow

The jack fixture 28 is provided on the rear plate 10D of the front boom 10 adjacent to the boom-side jack fixing plate 10H. As shown in FIGS. 4 and 7, the jack fixing member 28 is formed by bending a steel plate or the like into an L shape, and is fixed to the back plate 10D using means such as welding. The jack fixture 28 has a mounting plate 28A that rises upward from the back plate 10D. abut (see FIG. 7). The mounting plate 28A is formed with two bolt insertion holes 28B penetrating in the plate thickness direction. . Therefore, by screwing the bolt 29 inserted through the bolt insertion hole 28B into the nut 21D of the cylinder-side base member 21, the jack 18 can be fixed at the retracted position.

The hydraulic excavator 1 for demolition work according to the present embodiment has the configuration described above, and the hydraulic excavator 1 self-travels to the vicinity of the structure to be demolished by the undercarriage 2 . Then, the crusher 12 of the working device 7 crushes the building or the like and disposes of the crushed building or the like on the carrier (not shown) of the transportation vehicle.

During this dismantling work, the jack 18 is in the retracted position indicated by the solid line in FIG. As a result, the jack 18 can be prevented from rattling due to the operation of the working device 7 during dismantling work, and the jack 18 can be protected.

Next, when transporting the hydraulic excavator 1 to the site of demolition work, the lower boom 9A and the boom cylinder 14 are removed from the revolving frame 4 of the upper revolving structure 3 . In this way, the hydraulic excavator 1 is divided into the vehicle body (the lower traveling body 2 and the upper revolving body 3) and the working device 7, and the vehicle body and the working device 7 are individually loaded on the carrier vehicle and individually worked. Transport to site. Furthermore, when the arm 11 constituting the working device 7 is long, the arm 11 is removed from the front boom 10 and the rod 16B side of the arm cylinder 16 is removed from the arm 11 . At this time, the tube 16A side of the arm cylinder 16 is connected to the front boom 10 via the pin 16D.

When removing the arm 11, as shown in FIG. 3, with the crusher 12 removed from the tip of the arm 11, the jib cylinder 15 is contracted and the arm cylinder 16 is extended so that the work implement cylinder 17 is moved downward and downward. The arm 11 is placed on the arm support base 30 so that Next, the jack 18 is moved from the storage position indicated by the solid line in FIG. 7 to the working position indicated by the two-dot chain line. That is, the bolt 29 fixing the jack 18 to the jack fixture 28 is removed, and the boom-side base member 19 is rotated about the hinge mechanism 20 until it contacts the boom-side jack fixing plate 10H. In this state, the screw shaft 27 of the jack 18 is rotated to extend the jack 18 and bring the cylinder-side base member 21 into contact with the cylinder-side jack fixing plate 16F of the arm cylinder 16 . Then, by inserting the bolt 22 into the bolt insertion hole 16G of the cylinder-side jack fixing plate 16F and screwing it onto the nut 21D of the cylinder-side base member 21, the cylinder-side base member 21 is attached to the lower surface of the cylinder-side jack fixing plate 16F. fixed.

Thus, the jack 18 is moved to the working position shown in FIGS. 4 and 5, and the arm cylinder 16 is supported by the jack 18 from below. After that, the pin hole 16C at the tip of the rod 16B of the arm cylinder 16 and the pin hole 11C of the cylinder bracket 11B of the arm 11 are precisely aligned by rotating the screw shaft 27 appropriately to extend and contract the jack 18 finely. be able to. As a result, the pin 16E that connects the arm cylinder 16 and the arm 11 can be easily removed.

After removing the pin 16E that connects the arm cylinder 16 and the arm 11, the pin 11A that connects the front boom 10 and the arm 11 is removed. As a result, the arm 11 is removed from the work device 7 , and the arm 11 is loaded on the transport vehicle while being placed on the arm support base 30 and transported to the work site separately from the work device 7 .

In this manner, the hydraulic excavator 1 is transported to the work site in a state in which it is divided into the vehicle body composed of the lower traveling body 2 and the upper revolving body 3, the arm 11, and the work device 7 from which the arm 11 is removed. be. Then, the vehicle body, the working device 7 and the arm 11 which are individually transported are assembled as the hydraulic excavator 1 at the work site.

When assembling the hydraulic excavator 1, first, the work device 7 from which the arm 11 has been removed is lifted by using a crane or the like (not shown), and the base end of the lower boom 9A and the bottom side of the boom cylinder 14 are connected to each other by the swing frame 4. support bracket. Next, after the lower traveling body 2 is allowed to travel by itself to the vicinity of the arm 11 placed on the ground while being supported by the arm support base 30, the jib cylinder 15 is extended and contracted, etc., so that the front boom 10 is formed at the tip of the front boom 10. The pin holes are aligned with the pin holes formed in the arm 11, and the two are connected via the pins 11A.

Next, as shown in FIG. 2, while the arm cylinder 16 is supported from below by the jack 18, the screw shaft 27 of the jack 18 is appropriately rotated while the arm cylinder 16 is extended and retracted, so that the jack 18 is finely extended and retracted. Let As a result, the positions of the pin hole 16C at the tip of the rod 16B of the arm cylinder 16 and the pin hole 11C of the cylinder bracket 11B of the arm 11 can be finely adjusted for accurate alignment. As a result, the pin 16E can be smoothly inserted into the pin hole 16C on the arm cylinder 16 side and the pin hole 11C on the arm 11 side. and can be easily connected.

As described above, in the present embodiment, when the pin 16E is inserted into and removed from the rod 16B of the arm cylinder 16 and the arm 11, the work of aligning the pin hole 16C on the arm cylinder 16 side and the pin hole 11C on the arm 11 side is performed. can be performed by raising and lowering the arm cylinder 16 using the jack 18 and by extending and retracting the arm cylinder 16 . Therefore, when the pin 16E of the hydraulic excavator 1 is inserted and removed, the operator only needs to extend and retract the arm cylinder 16. As shown in FIG. Therefore, for example, when the tip of the arm cylinder is connected to the arm using a pin as in the prior art, there is no need to perform the boom hoisting operation by the boom cylinder and the extension operation of the arm cylinder in parallel. The operator's burden can be reduced.

Furthermore, the pin 16E, which is heavy, can be easily inserted and removed by ground work from the pin hole 11C of the arm 11 placed on the ground while being supported by the arm support base 30 and the pin hole 16C of the arm cylinder 16 side. can do. Therefore, by raising and lowering the boom as in the prior art, it is possible to improve workability when inserting and removing the pin 16E compared to the case where the position of the pin hole on the arm side is raised.

Thus, the hydraulic excavator 1 according to the present embodiment includes a self-propellable vehicle body and a working device 7 provided on the upper revolving body 3. The working device 7 is attached to the upper revolving body 3 at its proximal end and includes a boom cylinder. 14, a boom 8 that rotates with respect to the upper revolving body 3; an arm 11 that has its proximal end attached to the tip of the boom 8 and rotates with respect to the boom 8 by an arm cylinder 16; The arm cylinder 16 has one end rotatably connected to the boom 8 and the other end rotatably connected to the cylinder connecting portion (pin hole 11C) of the arm 11 using a pin 16E. Between the boom 8 and the arm cylinder 16, the other end (pin hole 16C) of the arm cylinder 16 is connected to the cylinder connecting portion (pin hole 11C) of the arm 11 by raising and lowering the arm cylinder 16 with respect to the boom 8. A jack 18 is provided to align against.

According to this configuration, by raising and lowering the arm cylinder 16 with respect to the boom 8 by the jack 18, the position of the pin hole 16C of the arm cylinder 16 with respect to the pin hole 11C of the arm 11 can be finely adjusted for accurate alignment. can be done. As a result, it is possible to improve workability when inserting and withdrawing the pin 16E that connects the boom 8 and the arm cylinder 16. As shown in FIG.

In the embodiment, a boom-side jack fixing plate 10H is provided on the back surface of the boom 8 facing the arm cylinder 16, and a cylinder-side jack fixing plate 16F is provided on a portion of the outer peripheral surface of the arm cylinder 16 that faces the back surface of the boom 8. The jack 18 has one end (the boom-side base member 19) in the telescopic direction fixed to the boom-side jack fixing plate 10H, and the other end (the cylinder-side base member 21) in the telescopic direction is fixed to the cylinder-side jack fixing plate 16F. fixed to According to this configuration, the expansion and contraction of the jack 18 can be reliably transmitted to the arm cylinder 16 and the back surface of the boom 8 , and the arm cylinder 16 can be finely raised and lowered according to the expansion and contraction of the jack 18 .

In the embodiment, a hinge mechanism 20 is provided between the boom-side jack fixing plate 10H and one end (boom-side base member 19) of the jack 18 in the telescoping direction. A fastener (bolt 22) is provided between the other end (cylinder-side base member 21) to detachably fix the two. With the other end (cylinder-side base member 21) removed, the work position is raised from the boom-side jack fixing plate 10H to the arm cylinder 16 side centering on the hinge mechanism 20, and the boom 8 is folded to the back side. It is configured to be movable between a storage position and a retracted position. According to this configuration, by moving the jack 18 to the retracted position, it is possible to prevent the arm cylinder 16 from interfering with the jack 18 during work using the work device 7 .

In an embodiment, the boom 8 is provided with a jack fixture 28 that secures the jack 18 in the retracted position. According to this configuration, the jack 18 can be prevented from rattling with respect to the boom 8 when the working device 7 is operated, and the jack 18 can be protected.

In the embodiment, the boom 8 includes a main boom 9 rotatably attached to the upper revolving structure 3 at its base end, and an arm 11 rotatably attached at its tip to the tip of the main boom 9 at its base end. An arm cylinder 16 is provided between the front boom 10 and the arm 11, and a jack 18 is provided between the front boom 10 and the arm cylinder 16. ing. According to this configuration, by raising and lowering the arm cylinder 16 with respect to the front boom 10 by the jack 18, the position of the pin hole 16C of the arm cylinder 16 with respect to the pin hole 11C of the arm 11 can be finely adjusted to achieve accurate alignment. It can be carried out.

Note that, in the embodiment, in the hydraulic excavator 1 including the multi-boom work device 7 including the main boom 9 and the front boom 10, a configuration in which the jack 18 is provided between the front boom 10 and the arm cylinder 16 is exemplified. is doing. However, the present invention is not limited to this, and can be applied to, for example, a working device provided with a single boom.

Moreover, in the embodiment, the case of using a manually operated jack 18 having a screw shaft 27 is illustrated. However, the present invention is not limited to this, and may be configured to use an electric or hydraulic jack, for example.

Furthermore, in the embodiment, a crusher 12 for demolition work is exemplified as a working tool attached to the tip of the arm 11 . However, the present invention is not limited to this, and can be widely applied to hydraulic excavators equipped with other work implements such as buckets, grapples, and lifting magnets.

1 hydraulic excavator 2 undercarriage (body)
3 Upper revolving body (body)
7 work device 8 boom 9 main boom 10 front boom 10H boom side jack fixing plate (boom side jack fixing part)
11 arm 11C pin hole (cylinder connecting part)
12 crusher (working device)
14 boom cylinder 16 arm cylinder 16E pin 16F cylinder side jack fixing plate (cylinder side jack fixing part)
17 Work tool cylinder 18 Jack 19 Boom side base member (one end in telescopic direction)
20 Hinge mechanism 21 Cylinder-side base member (other end in extension direction)
22 bolts (fasteners)
28 jack fixture

Claims (5)

Consists of a self-propellable vehicle body and a working device provided on the vehicle body,
The working device is
a boom whose base end is attached to the vehicle body and which rotates with respect to the vehicle body by a boom cylinder;
an arm whose base end side is attached to the tip of the boom and rotates with respect to the boom by an arm cylinder;
and a work tool attached to the tip of the arm,
The construction machine, wherein one end of the arm cylinder is rotatably connected to the boom and the other end is rotatably connected to the cylinder connecting portion of the arm using a pin,
A jack is provided between the boom and the arm cylinder for aligning the other end of the arm cylinder with the cylinder connecting portion of the arm by raising and lowering the arm cylinder with respect to the boom. A construction machine characterized by: A boom-side jack fixing portion is provided on the back surface of the boom facing the arm cylinder,
A cylinder-side jack fixing portion is provided at a portion of the outer peripheral surface of the arm cylinder that faces the back surface of the boom,
The construction machine according to claim 1, wherein one end of the jack in the telescopic direction is fixed to the boom-side jack fixing portion, and the other end in the telescopic direction is fixed to the cylinder-side jack fixing portion. A hinge mechanism is provided between the boom-side jack fixing portion and one end of the jack in the telescopic direction,
A fastener is provided between the cylinder-side jack fixing portion and the other end of the jack in the expansion/contraction direction to detachably fix the two,
and a work position where the jack rises from the boom-side jack fixing portion to the arm cylinder side about the hinge mechanism in a state where the other end of the jack in the extension direction is removed from the cylinder-side jack fixing portion. 3. The construction machine according to claim 2, wherein the boom is movable between a retracted position in which the boom is folded to the rear side of the boom. 4. The construction machine according to claim 3, wherein said boom is provided with a jack fixture for fixing said jack in said retracted position. a main boom having a proximal end rotatably attached to the vehicle body;
a front boom having a proximal end rotatably attached to the tip of the main boom and having the arm rotatably attached to the tip,
The arm cylinder is provided between the front boom and the arm,
The construction machine according to claim 1, wherein the jack is provided between the front boom and the arm cylinder.

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