Construction machine

Abstract

To provide a construction machine capable of lifting and lowering a counterweight by itself when attaching and detaching the counterweight, even in a small machine having no space at the rear side of an upper revolving body.SOLUTION: A hydraulic excavator 1 has an articulated working device 4. The working device 4 includes a boom 5 having a base end connected to an upper revolving body 3, an arm 6 having a base end provided at a tip of the boom 5, a pulley 210 provided on top of a roof 56a of a cab 56 and supporting a wire 100 connecting the arm 6 and a counterweight CW, and a connecting member 300 connecting the boom 5 and a support mechanism 200. The support mechanism 200 abuts an intermediate portion of the wire 100 to guide movement of the wire 100 so that the counterweight CW moves up and down in response to pitching motion of the arm 6, and includes the pulley 210 configured to be movable in the front-rear direction in response to pitching motion of the boom 5 connected to the connecting member 300.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a construction machine equipped with a counterweight on an upper rotating body. [Background technology]

[0002] Generally, in construction machinery such as hydraulic excavators that have a lower traveling body and an upper rotating body, a counterweight is provided at the rear of the upper rotating body to balance the weight of the working devices such as a boom and arm that are provided at the front of the upper rotating body.

[0003] For example, a hydraulic excavator may be used with a variety of different working implements, each with a different weight, depending on the type of work being performed. In this case, it may be necessary to replace the counterweight with a different weight for each working implement. Furthermore, because the counterweight is heavy, when the hydraulic excavator is transported to a work site or the like using a trailer or the like, the counterweight may be transported separately from the upper rotating body.

[0004] In response to the above, a technology has been known in the past that allows the counterweight to be attached and detached to the rear end by the user using a counterweight attachment / detachment device provided at the rear of the upper rotating body (see, for example, Patent Document 1).

[0005] Patent Document 1 discloses a counterweight attachment / detachment device for a construction vehicle with a detachable counterweight attached to the rear of a rotating upper body, the device comprising a hydraulic cylinder rotatably arranged with a support point on the frame of the rotating upper body, a first cable connecting the tip of the rod of the hydraulic cylinder to the boom, and a second cable connecting the tip of the rod to the counterweight. In this device, a hydraulic cylinder dedicated to raising and lowering the counterweight is provided at the rear of the rotating frame of the rotating upper body, making it possible to lift and lower the counterweight by the machine body alone by extending and retracting the hydraulic cylinder and raising and lowering the boom. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-78629 Summary of the Invention [Problem to be solved by the invention]

[0007] However, from the standpoint of transporting the vehicle body and ensuring visibility for the operator, there is a limit to the space available for storing parts on the upper rotating body, so it may be difficult to install equipment such as a hydraulic cylinder dedicated to raising and lowering the counterweight at the rear of the upper rotating body as in Patent Document 1.

[0008] The present invention has been made in consideration of the above circumstances, and its object is to provide a construction machine that can raise and lower the counterweight using the machine body alone, without having to install a hydraulic cylinder dedicated to raising and lowering the counterweight at the rear of the upper rotating body. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a construction machine having a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body and equipped with a driver's cab, a counterweight detachably mounted on the rear of the upper rotating body, and a multi-joint working device mounted on the front of the upper rotating body so as to be able to be raised and lowered, the multi-joint working device including a first front member having a base end connected to the upper rotating body and a second front member having a base end mounted on a tip end of the first front member. and a connecting member that connects the other front member, different from the one of the first and second front members, to the support mechanism, wherein the support mechanism abuts against an intermediate portion of the wire to guide the movement of the wire so that the counterweight rises and falls in response to the elevation and depression of the one front member, and has an abutment portion configured to be movable in the front-to-rear direction in response to the elevation and depression of the other front member connected to the connecting member. [Effects of the Invention]

[0010] According to the present invention, the counterweight can be raised and lowered when attached or detached using the machine body alone, without the need to install a hydraulic cylinder dedicated to raising and lowering the counterweight. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a left side view showing the overall external structure of a hydraulic excavator according to an embodiment of the present invention; [Figure 2] FIG. 2 is a top view of the hydraulic excavator shown in FIG. [Figure 3] FIG. 2 is a rear view of the hydraulic excavator shown in FIG. [Figure 4] 4(a) is an enlarged view of the vicinity of the swing mechanism in FIG. 4(a), and FIG. 4(b) is an explanatory diagram showing the swing behavior of the swing mechanism in FIG. 4(b). [Figure 5]5(a) is a perspective view of the hydraulic excavator shown in FIG. 1 from the right rear, and an enlarged view of the vicinity of the swing mechanism in FIG. 5(a). [Figure 6] FIG. 10 is a left side view showing the behavior of the counterweight moving up and down due to the arm's forward and backward raising and lowering motion. [Figure 7] FIG. 10 is a left side view showing the behavior of the counterweight moving forward and backward due to the boom hoisting operation. [Figure 8] FIG. 10 is a left side view illustrating the behavior of the counterweight when it is raised and lowered in a modified example in which the connecting member is provided with a plurality of locking points. [Figure 9] FIG. 9 is a rear view illustrating the behavior shown in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] <Overview of hydraulic excavator> FIG. 1 shows a left side view, FIG. 2 shows a top view, and FIG. 3 shows a rear view, illustrating the overall external structure of a hydraulic excavator 1, which is an example of a construction machine to which a boom for construction machine according to this embodiment can be applied. In FIGS. 1 to 3, the hydraulic excavator 1 is a construction machine used for excavation work, for example. Note that the present invention may be applied to other construction machines besides the hydraulic excavator 1, which are equipped with a working device, as described below. In the following description of the present application, an example in which the present invention is applied to a hydraulic excavator 1 will be described.

[0014] In this example, the hydraulic excavator 1 is a small hydraulic excavator (mini-excavator) used in relatively narrow work sites such as urban areas. The body of the hydraulic excavator 1 is mainly composed of a self-propelled crawler-type lower traveling body 2 and an upper rotating body 3 rotatably mounted on the lower traveling body 2. In this example, the turning radius of the upper rotating body 3 is configured to be approximately within the vehicle width of the lower traveling body 2.

[0015] A working device 4 is mounted on the front of the upper rotating body 3 via a swing post 51 so as to be able to move up and down. The working device 4 has an articulated structure, and its base end on the upper rotating body 3 side is supported via the swing post 51 so as to be able to swing left and right and move up and down. The working device 4 includes a boom 5 (first front member, the other front member) driven by a boom cylinder 52, an arm 6 (second front member, one front member) whose base end is connected to the tip of the boom 5 so as to be able to move up and down and is driven by an arm cylinder 53, and a bucket 7 rotatably connected to the tip of the arm 6 and driven by a bucket cylinder 54. The boom 5, arm 6, and bucket 7 each constitute a front member. A boom cylinder bracket 5A is provided on the underside of the boom 5, and an arm cylinder bracket 5B is provided on the upper side of the boom 5. The rod side of a boom cylinder 52 is connected to the boom cylinder bracket 5A, and the bottom side of the boom cylinder 52 is connected to the swing post 51. The bottom side of an arm cylinder 53 is connected to the arm cylinder bracket 5B. An arm cylinder bracket 6A is provided on the upper side of the base end of the arm 6, and the rod side of the arm cylinder 53 and the bottom side of the bucket cylinder 54 are connected to the arm cylinder bracket 6A.

[0016] The upper rotating body 3 is provided with a rotating frame 55 that serves as a support structure for the upper rotating body 3. A cab 56 (operator's compartment) equipped with pillars and glass is disposed on the left and front side of the rotating frame 55. The cab 56 serving as an operator's compartment does not include equipment such as the mirror 400 and antenna described below. The cab 56 is provided with a driver's seat (not shown) where an operator sits and operates each part of the hydraulic excavator 1. Since the cab 56 is located on the left side of the rotating frame 55, the boarding door to the cab 56 is also provided on the left side thereof. In the following description, the up-down direction, the front-back direction, and the left-right direction correspond to the directions of arrows appropriately shown in each drawing such as FIG. 1. In other words, "up," "down," "left," "right," "front," and "rear" in the drawings correspond to the up-down, left-right, front-rear, and front-rear directions as seen from the operator seated in the operator's seat inside the cab 56.

[0017] A plurality of onboard devices such as an engine, a hydraulic pump, etc. are also mounted on the rotating frame 55. Of the upper rotating body 3, the portion other than the cab 56 is covered with a building cover 9, and the plurality of onboard devices are also covered by the building cover 9. Furthermore, a substantially recessed mounting portion (not shown) for mounting a counterweight CW is provided in a portion of the building cover 9 located at the rear of the upper rotating body 3, and the counterweight CW is detachably mounted on the mounting portion.

[0018] <Main parts of the embodiment> Here, the main part of this embodiment is a mechanism for lifting and lowering the counterweight CW when attaching or detaching it to or from the attachment portion of the building cover 9. Details thereof will be explained below in order.

[0019] <Connection between counterweight and arm> In this embodiment, the counterweight CW and the arm 6 are connected by a wire 100 (wire material). Note that the wire material may be something other than a wire, such as a rope or chain. The counterweight CW is provided with rings 60 at two locations, left and right, to connect the wire 100. In this embodiment, hooks 101 are provided at both ends of the wire 100, and when lifting or lowering the counterweight CW, the hooks 101 engage with the rings 60 at the left and right locations, respectively.

[0020] At this time, in order to lock the wire 100 extending to the counterweight CW, the arm 6 has a wire engaging hole 6B (see also Figures 4 and 5 described later) formed in the arm cylinder bracket 6A. An intermediate portion of the wire 100 having hooks 101, 101 at both ends is inserted into the wire engaging hole 6B. In other words, the wire engaging hole 6B of the arm cylinder bracket 6A is positioned between the hooks 101, 101 along the length of the wire 100. As a result, the wire 100, which is bent in a Π shape with the hooks 101, 101 at both ends and extends, is locked with the arm 6 at the intermediate portion of the Π shape.

[0021] At this time, a wire engaging hole 6B is provided on each of the left and right sides of the arm cylinder bracket 6A. When viewed in terms of positional relationship in the left-right direction, as shown in Figures 2 and 4, the left pulley 210, the left wire engaging hole 6B, the right wire engaging hole 6B, and the right pulley 210 are arranged in this order from left to right. Similarly, when viewed in terms of positional relationship in the left-right direction, as shown in Figures 2 and 4, the left hook 101, the left wire engaging hole 6B, the right wire engaging hole 6B, and the right hook 101 are arranged in this order from left to right. With this configuration, it is difficult for a load that twists the working device 4 in the left-right direction to be applied (i.e., a load that pulls the working device 4 backward, i.e., a load that is applied in the direction of rotation of the working device 4), thereby preventing damage to the working device 4. Note that instead of inserting the wire 100 through the wire engaging hole 6B, the wire 100 may be locked to the arm 6 with an appropriate locking device.

[0022] <Swing mechanism for wire relay> On the other hand, as shown in Figures 4 and 5, support mechanisms 200 that relay and support the intermediate portion of the wire 100 extending from the arm 6 to the counterweight CW as described above are provided at two locations, left and right, on the top surface of the cab 56 (more specifically, the top surface of the roof 56a). Note that the configuration is not limited to the above, in which one wire 100 is used to connect one (e.g., left) ring portion 60 → one (e.g., left) support mechanism 200 → wire engagement hole 6B of arm 6 → other (e.g., right) support mechanism 200 → other (e.g., right) ring portion 60. That is, for example, two wires 100A and 100B (not shown) may be used, with one (e.g., left) wire 100A connecting one (e.g., left) ring portion 60 → one (e.g., left) support mechanism 200 → arm 6, and the other (e.g., right) wire 100B connecting the other (e.g., right) ring portion 60 → the other (e.g., right) support mechanism 200 → arm 6. In this case, as described above, it is sufficient to fasten each of wires 100A and 100B to an appropriate location on arm 6 using an appropriate fastener.

[0023] As shown in FIGS. 4(b) and 5(b), the support mechanism 200 includes two pulleys 210 (abutment portions), left and right, that abut against an intermediate portion of the wire 100 extended as described above and support the wire 100, and two substantially L-shaped support bases 220, left and right, that support the pulleys 210 so that they can swing in the front-to-rear direction relative to the upper portion of the cab 56 (the upper surface of the roof 56a). As a result, the wire engaging hole 6B of the arm cylinder bracket 6A described above is located between the right pulley 210 and the left pulley 210 along the length direction of the wire 100. Note that the support mechanism 200 is not limited to the pulleys 210, and any member that abuts against an intermediate portion of the wire 100 and supports the wire 100 may be used, for example, a sliding bush or the like.

[0024] The support base 220 comprises a base 221 which corresponds to the bottom of an approximately L-shape, an upright portion 222 which swings upright relative to the base 221 and rotatably supports the pulley 210, and a pin 223 which rotatably connects the upright portion 222 to the base 221.

[0025] The base 221 is attached to the upper part of the cab 56 (the upper surface of the roof 56a) with mounting bolts 224, which are shown in outline by dashed lines in Figure 4(b). This makes the entire support mechanism 200 detachable from the upper surface of the roof 56a via the bolts 224. The pulley 210 is disposed rearward of the rear end of the cab 56.

[0026] As shown in FIG. 4(c), the upright portion 222 is provided with a curved surface 222a at a sliding portion with the base portion 221 via the pin 223. Due to the shape of this curved surface 222a, the upright portion 222 is configured to be able to swing relative to the base portion 221 only within the range of the angle θ shown in the figure (a predetermined range). In other words, the curved surface 222a functions as a restricting portion that restricts the swing of the upright portion 222 within the range of the angle θ. The swing of this upright portion 222 allows the pulley 210 to move forward and backward. The pulley 210 and the upright portion 222 constitute a support mechanism.

[0027] <Connection between swing mechanism and boom> At this time, the upright portions 222 of the two left and right support mechanisms 200 are connected to the boom 5 by two appropriate connecting members 300, respectively. The connecting members 300 may be linear members such as wires, ropes, or chains, or may be rigid members such as metal members, such as sheet metal. As shown in FIG. 4(b), the upright portions 222 of the left and right support mechanisms 200 each have a ring portion 225 (first locking portion) for locking the rear end portion (one end) of the connecting member 300. In this embodiment, hooks 301, 302 are provided at both ends of the left and right connecting members 300, respectively, and the rear hook 301 is engaged with the ring portion 225 of the support mechanism 200.

[0028] The boom 5 has a locking hole (not shown, corresponding to the second locking portion) formed in the boom cylinder bracket 5B to lock the front end (other end) of the connecting member 30, more specifically, the front hook 302. The hook 302 of the connecting member 300 is appropriately locked to this locking hole. That is, when viewed along the length of the series of connecting member 300, which is from the ring portion 225 of the support mechanism 200 including the left pulley 210, to the left hook 301, to the left connecting member 300, to the left hook 302, to the right hook 301, to the right connecting member 300, to the right hook 301, back to the ring portion 225 of the support mechanism 200 including the right pulley 210. As a result, two connecting members 300 extending linearly with hooks 301, 302 at both ends connect the support mechanism 200 and the boom 5, respectively.

[0029] In this case, a lifting through-hole used for lifting the boom 5 during manufacturing and assembling the hydraulic excavator 1 (or for lifting the boom 5 when replacing the boom 5) may be used as the locking hole of the boom cylinder bracket 5B. Furthermore, the lifting through-hole may function as a through-hole for lifting the entire hydraulic excavator 1 after assembly.

[0030] The dimensions of each part of the support base 220 and the angle θ are set so that the connecting member 300 connecting the upright portion 222 supporting the pulley 210 and the boom 5 does not interfere with the upper part of the cab 56 (the upper surface of the roof 56a) within the maximum swing range of the pulley 210 by the support mechanism 200 described above. That is, in detail, the locking hole of the boom cylinder bracket 5B is provided in a position such that when the upright portion 222 of the support base 220 is within the range of the angle θ, the straight line connecting the locking hole of the boom cylinder bracket 5B and the ring portion 225 does not overlap the cab 56.

[0031] <Counterweight up and down movement> FIG. 6 shows the behavior of the counterweight CW moving up and down due to the forward and backward raising and lowering motion of the arm 6 in the hydraulic excavator 1 configured as described above.

[0032] As described above, the wire 100 extends along the path from the arm 6 to the pulley 210 to the counterweight CW in a generally inverted L-shape in side view, as shown in Fig. 6. As a result, the reciprocating motion of the wire 100 in the generally forward and backward directions caused by the arm 6 being raised and lowered in the forward and backward directions can be converted by the pulley 210 into reciprocating motion of the wire 100 in the generally up and down directions, thereby raising and lowering the counterweight CW. In other words, the pulley 210 of the support mechanism 200 guides the movement of the wire 100 so that the counterweight CW rises and falls in accordance with the elevation and depression of the arm 6.

[0033] 6, when the arm 6 is in a bent position relative to the boom 5 as indicated by the dashed line, the length of the upper portion 100U of the wire 100 located forward of the pulley 210 is relatively long, and the length of the lower portion 100L located below the pulley 210 is relatively short. As a result, the counterweight CW connected to the wire 100 can be raised to a position indicated by the dashed line (for example, the same height as when the counterweight CW is attached to the attachment portion of the building cover 9 described above). When the arm 6 is moved from this counterweight CW state to an extended position relative to the boom 5 as indicated by the dashed line (see the arrow in the figure), the height of the left end of the wire 100 in the figure decreases, and the length of the upper part 100U becomes slightly shorter due to the rotation of the pulley 210. As a result, the length of the lower part 100L of the wire 100 becomes longer by the amount that the upper part 100U has become shorter, and the counterweight is lowered to a low position (for example, above the ground) as indicated by the solid line (indicated by the symbol CW′).

[0034] Although not shown in the drawings and detailed description, the counterweight CW can be raised from the solid line position to the broken line position in the drawing by moving the arm 6 from the extended position to the bent position in the opposite direction to the above.

[0035] <Counterweight forward and backward movement> FIG. 7 shows the behavior of the counterweight CW moving back and forth due to the forward and backward raising and lowering operation of the boom 5 in the hydraulic excavator 1 configured as described above.

[0036] As described above, the connecting member 300 is extended to connect the boom 5 and the support mechanism 200. As a result, by raising and lowering the boom 5 fore and aft (boom-raising operation and boom-lowering operation), the upright portion 222 of the support mechanism 200 is swung via the connecting member 300, and the pulley 210 can be moved forward and backward. In other words, the pulley 210 of the support mechanism 200 is configured to be movable in the front-rear direction in response to the elevation and depression of the boom 5. As a result, the lower portion 100L of the wire 100 can be moved in the front-rear direction, and the counterweight CW connected to the lower end of the lower portion 100L can be moved in the front-rear direction.

[0037] 7, when the boom 5 is in a relatively lowered position as indicated by the dashed line, the upright portion 222 swings to a slightly upright position as indicated by the dashed line via the connecting member 300. As a result, the hook 101 provided at the lower end of the lower portion 100L of the wire 100 can be engaged with the ring portion 60 of the counterweight CW (see dashed line) when it is attached to the attachment portion of the building cover 9 described above. When the boom 5 is raised from this state of the counterweight CW to the position indicated by the solid line (see the arrow in the figure), the upright part 222 of the support mechanism 200 swings to a slightly reclined position due to the weight of the counterweight CW via the connecting member 300. This causes the pulley 210 to move rearward, and the lower part 100L of the wire 100 to move rearward, allowing the counterweight CW connected to the lower end of the lower part 100L to be retracted (indicated by the symbol CW″).

[0038] Although not shown in the drawings or in detailed description, the counterweight CW can be advanced by lowering the boom 5 from the solid line position to the broken line position in the opposite direction to the above.

[0039] <Backward confirmation device> In the hydraulic excavator 1 of this embodiment, a mirror 400 (rearview confirmation device) that allows at least the top surface of the counterweight CW to be viewed is provided at the rear of the cab 56 to enable confirmation when raising or lowering the counterweight CW as described above. In this example, the mirror 400 is a convex mirror and is attached to the rear edge of the top surface of the roof 56a via an arm 401. In particular, in this example, as shown in FIG. 5(a), the mirror 400 is positioned approximately between the right pulley 210 and the left pulley 210 in the inner region of the wire 100 that extends in the longitudinal direction, from the left ring portion 60 engaged with the left hook 101 of the counterweight CW to the left pulley 210 to the wire engaging hole 6B of the arm cylinder bracket 6A to the right pulley 210 to the right ring portion 60 to the right hook 101 of the counterweight CW. Note that the arm 401 may be configured to be detachable from the roof 56a. The operator in the cab 56 can view the top surface of the counterweight CW while seated in the driver's seat through this mirror 400. In particular, with the above arrangement, the operator can check the connection status of both the left and right hooks 101, 101 and the wire 100 by simply checking the single mirror 400.

[0040] Note that a known camera may be provided as a rearview confirmation device instead of the mirror 400. In this case, by providing a monitor that displays the captured image near and in front of the driver's seat, the operator can visually confirm the top surface of the counterweight CW while remaining seated in the driver's seat, as described above. Furthermore, the operator can visually confirm the state of the working implement 4 and the status of the counterweight CW without having to change his or her posture, such as by turning around. This improves work efficiency and prevents the working implement 4 from coming into contact with surrounding objects.

[0041] <Effects of the embodiment> As described above, in this embodiment, the arm 6 of the working implement 4 is connected to the counterweight CW by the wire 100, and the wire 100 is supported by the support mechanism 200 provided on the upper surface of the roof 56a of the cab 56. The pulley 210 provided on the support mechanism 220 abuts against the middle portion of the wire 100 and guides the wire 100 in response to the elevation and depression of the arm 6, thereby raising and lowering the counterweight CW, and is configured to be movable in the front-to-rear direction in response to the elevation and depression of the boom 5 connected to the connecting member 300. As a result, as described above, the counterweight CW can be raised or lowered by raising and lowering the arm 6 in the front-to-rear direction, and the counterweight CW can be moved in the front-to-rear direction by raising and lowering the boom 5 in the front-to-rear direction. As a result, according to this embodiment, the counterweight can be raised and lowered by the machine body alone, without the need for a dedicated hydraulic cylinder for raising and lowering the counterweight, by appropriately operating the arm 6 and the boom 5. That is, when attaching the counterweight CW, the counterweight CW can be raised and advanced by the machine body alone from a desired position to the upper rotating body 3, and when removing the counterweight CW, the counterweight CW can be moved backward and downward from the upper rotating body 3, and can be suspended by the machine body alone to a desired position.

[0042] Furthermore, particularly in this embodiment, the support mechanism 200 including the pulley 210 is detachably mounted on the upper surface of the roof 56a. As a result, for example, during excavation work after the counterweight CW is attached, the support mechanism 200 can be removed from the upper surface of the roof 56a so as not to interfere with the excavation work. Furthermore, particularly because the pulley 210 is disposed further rearward than the rear end of the cab 56, the wire 100 does not interfere with the cab 56, and the operator can move the wire 100 to move the counterweight CW as intended.

[0043] In particular, in this embodiment, the support mechanism 200 includes a pulley 210 that abuts against the middle portion of the wire 100 extending from the arm 6 to the counterweight CW and supports the wire, and a support base 220 that supports the pulley 210 so that it can swing back and forth relative to the upper surface of the roof 56a. By using pulley 210, wire 100 extending in a generally inverted L shape as described above can be supported smoothly so as to be able to reciprocate. Furthermore, by supporting pulley 210 so as to be able to swing in the front-to-rear direction by support base 220, lower portion 100L of wire 100 hanging down from pulley 210 can be moved smoothly in the front-to-rear direction.

[0044] Furthermore, particularly in this embodiment, the upright portion 222 of the support base 220 is configured to be able to swing relative to the base portion 221 only within a range of angle θ (a predetermined range) due to the shape of the curved surface 222a. Furthermore, the locking hole of the boom cylinder bracket 5B is positioned so that, when the upright portion 222 is within the range of angle θ, a straight line connecting the locking hole of the boom cylinder bracket 5B and the ring portion 225 does not overlap with the cab 56. As a result, the support base 220 is configured so that the connecting member 300 connecting the pulley 210 to the boom 5 does not interfere with the upper surface of the roof 56a within the maximum swing range of the pulley 210. As a result, even if the vertical position of the connecting member 300 fluctuates when the support mechanism 200 including the pulley 210 is swung to move the counterweight CW forward or backward, the connecting member 300 can be prevented from contacting the upper surface of the roof 56a.

[0045] For example, if a dedicated lifting device such as a hydraulic cylinder is provided at the rear of the upper rotating body 3 as in the conventional structure, the rear of the upper rotating body 3 blocks the view, making it difficult to check the lifting status of the counterweight CW from inside the cab 56. Therefore, the operator must get off the machine to check the status each time it is raised or lowered, or a separate worker must be assigned to check the status. In contrast to this, in this embodiment, a mirror 400 is provided at the rear of the cab 56 so that the operator inside the cab 56 can see the top surface of the counterweight CW. This allows the operator to easily check the raised / lowered state of the counterweight CW from inside the cab 56.

[0046] <Modification> The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit and technical concept of the present invention. Such modifications will be described below.

[0047] <When multiple locking points are provided for the connecting member> In this modified example, a left side view showing the behavior of the hydraulic excavator 1 when raising and lowering the counterweight CW is shown in FIG. 8, and a rear view is shown in FIG.

[0048] 8, in this modification, the arm cylinder bracket 6A is provided with a plurality of wire engaging holes 6B1, 6B2, and 6B3 (engagement locations) as wire engaging portions. As in the above embodiment, when inserting the middle portion of the wire 100 having hooks 101 at both ends, in this modification, one of the wire engaging holes 6B1, 6B2, and 6B3 is selected and the wire 100 is inserted and engaged. As a result, by appropriately changing the wire engaging hole 6B1, 6B2, and 6B3 that actually engages the wire 100, the amount of lift of the counterweight CW when the arm 6 is raised and lowered in the forward and backward directions can be adjusted.

[0049] For example, in Fig. 8, the solid line shows a case where the wire 100 is engaged with the wire engaging hole 6B1, which is located closest to the tip of the arm 6, among the wire engaging holes 6B1, 6B2, and 6B3. In this case, the length of the upper portion 100U of the wire 100 becomes relatively long. As a result, when the arm 6 is moved to the extended position relative to the boom 5 as shown by the solid line in Fig. 6 in the above embodiment to lower the counterweight CW removed from the building cover 9, the counterweight CW will be lowered to the same height as the ground, for example.

[0050] In contrast, the case where the wire 100 is engaged with the wire engaging hole 6B3, which is located closest to the base end of the arm 6 among the wire engaging holes 6B1, 6B2, and 6B3, is shown by the two-dot chain line. In this case, the length of the upper portion 100U of the wire 100 is slightly shorter than that described above. As a result, even if the arm 6 is in the same position as described above, the counterweight CW can be lowered further downward, i.e., to a height lower than the ground. That is, in this case, as shown in FIG. 9, if a recess CV is formed in the ground E below the lower running body 2, the counterweight CW can be lowered into the recess CV. Note that FIG. 9 also shows, by a solid line, the position of the counterweight CW when the wire 100 is engaged with the wire engaging hole 6B1.

[0051] In this way, depending on which of the wire engaging holes 6B1, 6B2, and 6B3 the wire 100 is locked into, the position of the wire 100, in other words, the height position of the counterweight CW, can be changed even with the same posture of the arm 6. As a result, the range of up and down movement of the counterweight CW accompanying the forward and backward raising and lowering movement of the arm 6 can be adjusted, so that it is possible to flexibly respond to situations where the lifting distance or hanging distance of the counterweight CW when attaching or detaching it to or from the building cover 9 is long or short.

[0052] <Other> In the above description, the counterweight CW is raised or lowered via the wire 100 by raising or lowering the arm 6 fore and aft, and the counterweight CW is moved in the fore-and-aft direction via the connecting member 300 by raising or lowering the boom 5 fore and aft, but this is not limited to this. That is, a configuration may be adopted in which the wire 100 is connected to the boom 5 and the connecting member 30 is connected to the arm 6, and the counterweight CW is raised or lowered via the wire 100 by raising or lowering the boom 5 fore and aft, and the counterweight CW is moved in the fore-and-aft direction via the connecting member 300 by raising or lowering the arm 6 fore and aft. In this case, the boom 5 corresponds to one front member, and the arm 6 corresponds to the other front member. In this modified example, the same effects as those of the above embodiment are obtained.

[0053] <About the problem to be solved and the effects of the invention> The problems to be solved by the invention and the effects of the invention are not limited to those described above. That is, the present invention may solve problems or achieve effects not described above, or may solve only some of the problems or achieve only some of the effects described above.

[0054] In addition to the above, the methods according to the above embodiments and modifications may be used in appropriate combination.

[0055] Although not specifically illustrated, the present invention can be implemented with various modifications within the scope of the invention. [Explanation of symbols]

[0056] 1. Hydraulic excavator (construction machinery) 2 Undercarriage 3 Upper rotating body 4 Work equipment 5 Boom (first front member) 6 Arm (second front member) 6B Wire engagement hole 6B1 Wire engagement hole (locking point, wire rod locking portion) 6B2 Wire engagement hole (locking point, wire rod locking portion) 6B3 Wire engagement hole (locking point, wire rod locking portion) 56 Cab (operator's compartment) 56a Roof 100 Wire 100L lower 100U upper part 200 Support mechanism 210 Pulley (contact part) 220 Support stand 221 Base 222 Upright part 222a Curved surface (regulating part) 225 Ring part (first locking part) 300 Connecting member 400 Mirror (rearview device) CW Counterweight

Claims

1. a lower running body; an upper rotating body provided rotatably on the lower traveling body and having a driver's cab; A counterweight detachably provided at the rear of the upper rotating body; a multi-joint type working device provided at the front of the upper rotating body so as to be able to move up and down; and The articulated working device is a first front member having a base end connected to the upper rotating body; a second front member whose base end is provided at the tip end of the first front member; In construction machinery, including a support mechanism that is provided above the cab and supports a wire that connects one of the first front member and the second front member to the counterweight; a connecting member that connects the other front member, which is different from the one front member of the first front member and the second front member, to the support mechanism; Equipped with The support mechanism has an abutment portion that abuts against an intermediate portion of the wire rod and guides the movement of the wire rod so that the counterweight rises and falls in response to elevation and depression of the one front member, and that is configured to be movable in the front-rear direction in response to elevation and depression of the other front member connected to the connecting member. Construction machinery characterized by:

2. 2. The construction machine according to claim 1, The support mechanism includes: Removably provided on the top surface of the driver's cab, The contact portion is disposed rearward of the rear end of the driver's cab on the vehicle body. Construction machinery characterized by:

3. 2. The construction machine according to claim 1, The support mechanism includes: a pulley as the abutment portion that abuts against the intermediate portion of the wire rod and supports the wire rod; a support base that supports the pulley at the top of the cab so that the pulley can swing back and forth; A construction machine characterized by comprising:

4. 4. The construction machine according to claim 3, The support base is a base fixed to an upper portion of the cab; an upright portion pivotally attached to the base and rotatably supporting a pulley; Equipped with The upright portion is a restricting portion that restricts the swinging movement within a predetermined range; a first locking portion to which one end of the connecting member is locked; and the other front member has a second locking portion to which the other end of the connecting member is locked, The second engaging portion is provided at a position where a straight line connecting the first engaging portion and the second engaging portion does not overlap with the driver's cab when the posture of the upright portion is within the predetermined range. Construction machinery characterized by:

5. 2. The construction machine according to claim 1, The other front member has a plurality of wire rod locking portions that can selectively lock the wire rods. Construction machinery characterized by:

6. 2. The construction machine according to claim 1, a rear view device provided at the rear of the cab, which enables an operator in the cab to visually check the top surface of the counterweight; Construction machinery characterized by:

7. 2. The construction machine according to claim 1, The other front member is a boom connected to the upper rotating body so as to be able to move up and down, The one front member is An arm connected to the boom so as to be able to move up and down, Construction machinery characterized by:

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