Crane and camera support unit

Abstract

To provide a crane capable of suitably adjusting a mounting position of a camera to a reference height in response to a change in the number of stages of a counterweight.SOLUTION: The crane 100 capable of loading a plurality of stages of counterweights 111 includes the camera 13 that images the rear of the counterweight 111, the base member 51 attached to the counterweight 111, the holding section 52A that holds the camera 13 at the reference height H, and the bracket (the position adjusting section) 52 (the 52A and the 52B) capable of adjusting the height of the holding section 52A with respect to the base member 51 to be close to the reference height H irrespective of an increase or a decrease in the number of stages of the counterweights 111.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a crane capable of loading multiple levels of counterweights, and a camera support unit mounted on such a crane. [Background technology]

[0002] Cranes equipped with cameras for monitoring the surroundings are known. For example, Patent Document 1 discloses a crane that includes a rotating body rotatably mounted on a running body, a boom supported in a hoistable manner in front of the rotating body, a cab mounted on the front part of the rotating body, and a counterweight mounted on the rear end of the rotating body, in which multiple monitoring cameras are mounted on the left and right sides of the rotating body and on the counterweight, and images from each monitoring camera are displayed on a monitor in the cab in response to operation of an operating lever. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-128463 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, the camera that monitors the rear is mounted on the counterweight, so when the number of counterweight stages is changed, the height position of the camera changes, which poses a problem that the image from the camera may not be displayed correctly on the monitor.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and its main object is to provide a crane that can suitably adjust the camera mounting position to a reference height in response to changes in the number of counterweight stages. [Means for solving the problem]

[0006] In order to achieve the above object, a typical example of the present invention is a crane capable of carrying multiple stages of counterweights, which is characterized by comprising: a camera that captures images behind the counterweight; a base member that is attached to the counterweight; a holding part that holds the camera at a reference height; and a position adjustment means that can adjust the height of the holding part relative to the base member to approach the reference height, regardless of whether the number of stages of the counterweight is increased or decreased.

[0007] According to the present invention, the mounting position of the camera can be suitably adjusted to the reference height in response to a change in the number of stages of the counterweight. Note that problems, configurations, and effects other than those described above will become clear from the description of the following embodiments. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a crane according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the entire operator's cab. [Figure 3] FIG. 2 is a perspective view of the camera support unit as seen from the rear. [Figure 4] FIG. 2 is a perspective view of the camera support unit as seen from the front. [Figure 5] FIG. 10 is a perspective view showing a state in which brackets of the camera support unit are connected in the vertical direction. [Figure 6] FIG. 10 is a perspective view showing the installation state of the camera support unit relative to the counterweight with the standard number of steps. [Figure 7] FIG. 10 is a perspective view showing the installation state of the camera support unit relative to the counterweight in the increased stage state. [Figure 8] FIG. 10 is a perspective view showing the installation state of the camera support unit relative to the counterweight in the reduced stage state. [Figure 9] FIG. 10 is a perspective view of the camera support unit according to the first modification, as viewed from behind. [Figure 10] FIG. 10 is a perspective view of a camera support unit according to a first modified example, as viewed from the front. [Figure 11] FIG. 10 is a perspective view showing a state in which the camera support unit according to the first modification is installed on a counterweight with a standard number of steps. [Figure 12] FIG. 10 is a perspective view showing a state in which the camera support unit according to the first modification is installed on a counterweight with a reduced number of stages. [Figure 13] FIG. 10 is a perspective view showing a state in which the camera support unit according to the first modification is installed on a counterweight with a groove. [Figure 14] FIG. 10 is a perspective view showing a state in which the camera support unit according to the first modification is installed on a counterweight at an intermediate stage. [Figure 15] FIG. 10 is a perspective view showing a main part of a camera support unit according to Modification 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] Fig. 1 is a side view of a crane 100 according to an embodiment of the present invention. As shown in Fig. 1, the crane 100 has a running body 101, a rotating body 103 that is rotatably mounted on the running body 101 via a slewing ring 102, and a boom 104 that is rotatably supported on the rotating body 103. The running body 101 has a track frame 101a and a crawler 101b attached to the track frame 101a.

[0011] The rotating body 103 is provided with a driver's cab 109, and is equipped with an engine 107 as a prime mover, as well as a hoist drum 105 and a boom hoisting drum 106 as winches. A counterweight 111 is mounted at the rear end of the rotating body 103 to maintain balance with the load weight. The counterweight 111 is made up of multiple stacked pieces so that the total weight can be changed according to the weight of the load being lifted.

[0012] A hoist rope 105a is wound around the hoist drum 105, and is wound or unwound by the drive of the hoist drum 105, thereby raising or lowering the hook 110. One end of a pendant rope 106b is connected to the tip of the boom 104, and the other end of the pendant rope 106b is connected to a boom hoist rope 106a via a bridle 106c. The boom hoist rope 106a is looped multiple times between the bridle 106c and a hanger at the top of the gantry 106d, and is wound or unwound by the drive of the boom hoist drum 106, causing the boom 104 to rise and fall.

[0013] The rotating body 103 is driven to rotate by a hydraulic motor 151 for rotation via a slewing ring 102, the hoisting drum 105 is driven by a hydraulic motor 152 for hoisting, and the boom hoisting drum 106 is driven by a hydraulic motor 153 for boom hoisting.

[0014] Fig. 2 is a perspective view showing the entire operator's cab 109. As shown in Fig. 2, the operator's cab 109 is provided with an operator's seat 201 where an operator sits, a right-side lever group (travel lever, winch operation lever, etc.) 210 that the operator sitting in the operator's seat 201 operates with his right hand, and a left-side lever device 220 that the operator sitting in the operator's seat 201 operates with his left hand. A display device 231 (monitor) is provided on the left front side of the operator's seat 201, and displays various information including the operating status of the crane 100. Furthermore, a hoist drum brake pedal 252 for braking the hoist drum 105, a boom hoist drum brake pedal 262 for braking the boom hoist drum 106, and an accelerator pedal 261 for increasing or decreasing the rotational speed of the engine 107 are provided on the floor of the operator's cab 109.

[0015] Returning to Figure 1, a left camera 10 and a right camera 11 are provided on the left and right sides of the rotating unit 103, a front camera 12 is provided in the cab 109, and a rear camera 13 is provided on the counterweight 111. These cameras 10, 11, 12, and 13 capture images of a predetermined range around the rotating unit 103, and a composite image from each of the cameras 10, 11, 12, and 13 is displayed as a surround view image on a display device 231 in the cab 109.

[0016] Here, the total weight of the counterweight 111 may be changed by increasing or decreasing the number of loading levels, and when the number of loading levels of the counterweight 111 is changed, the mounting height of the rear-view camera 13 provided on the counterweight 111 changes. Therefore, in the crane 100 according to this embodiment, a camera support unit 50 that can adjust the height position of the rear-view camera 13 is mounted on the counterweight 111. The configuration of this camera support unit 50 will be described in detail below.

[0017] Fig. 3 is a perspective view of the camera support unit 50 as seen from the rear. Fig. 4 is a perspective view of the camera support unit 50 as seen from the front. Fig. 5 is a perspective view showing a state in which brackets 52 of the camera support unit 50 are connected in the vertical direction.

[0018] 3 to 5, the camera support unit 50 is configured to include a base member 51 attached to the counterweight 111 and a plurality of brackets 52 that function as position adjustment means. A rear-view camera 13 that captures images behind the counterweight 111 is attached to the camera support unit 50.

[0019] The base member 51 has a flat base portion 51a, a support portion 51b standing upright from the rear end of the base portion 51a, and a plurality of magnets 51c attached to the base portion 51a. The base member 51 is detachably attached to the upper surface of the counterweight 111 using the magnets 51c.

[0020] The brackets 52 are made of channel material with a length approximately equal to the thickness of the counterweight 111. In this embodiment, four brackets 52 are used, and in the following description, one of them will be referred to as the reference bracket 52A and the remaining three as selected brackets 52B. In this embodiment, all four brackets 52 are set to the same length because counterweights 111 of the same thickness are to be loaded.

[0021] Ear-shaped holding portions 52a are formed on both longitudinal ends of the reference bracket 52A. The distance between the two holding portions 52a corresponds to the thickness of each of the counterweights 111. Specifically, the distance between the two holding portions 52a is set to be approximately equal to the thickness of the counterweight 111, but it does not necessarily have to be set to be approximately equal. The camera 13 can be attached to these holding portions 52a using fasteners such as bolts. The reference bracket 52A is fixed to the front end side of the base portion 51a of the base member 51 so as to extend vertically, and a flange-shaped connecting portion 52b is formed on the upper end of the reference bracket 52A.

[0022] The three selection brackets 52B are common components with the same configuration. A lug-shaped holding portion 52a is formed on one longitudinal end of the selection bracket 52B. The distance between the other longitudinal end of the selection bracket 52B and the holding portion 52a corresponds to the thickness of each counterweight 111. Specifically, the distance is set to be approximately equal to the thickness of the counterweight 111, but it does not necessarily have to be set to be approximately equal. For example, the distance may be set to match the thickness of each counterweight 111. The camera 13 can be attached to the holding portion 52a using a fastener such as a bolt. Furthermore, flange-shaped connecting portions 52b are formed on both longitudinal ends of the selection bracket 52B, and multiple (e.g., three) mounting holes 52c are formed on one surface of the selection bracket 52B.

[0023] 3 and 4, the three selection brackets 52B can be made into a long, integrated part by fastening their connecting portions 52b to each other using fasteners such as bolts. Any selection bracket 52B can be supported on the base member 51 by fastening the mounting hole 52c on one side of the selection bracket 52B to the support portion 51b of the base member 51 using fasteners such as bolts.

[0024] Furthermore, the selection bracket 52B can be connected to the upper end of the reference bracket 52A, which stands up vertically, by fixing its own connecting portion 52b to the connecting portion 52b of the reference bracket 52A using fasteners such as bolts, as shown in Fig. 5. Note that up to three selection brackets 52B can be connected to the reference bracket 52A. In this case, the integrated reference bracket 52A and the three selection brackets 52B have holding portions 52a formed in five locations, and the holding portions 52a are arranged in the vertical direction at intervals equivalent to the thickness of one counterweight 111.

[0025] Next, an embodiment in which the camera support unit 50 configured as described above is mounted on a counterweight 111 with multiple stages will be described. Fig. 6 is a perspective view showing the installation state of the camera support unit 50 on a counterweight 111 with the standard number of stages. Fig. 7 is a perspective view showing the installation state of the camera support unit 50 on a counterweight 111 with an increased number of stages. Fig. 8 is a perspective view showing the installation state of the camera support unit 50 on a counterweight 111 with a decreased number of stages.

[0026] In the crane 100 according to this embodiment, the standard number of stages is when the counterweights 111 are stacked in six stages, and when the number of stages is increased from the standard number of stages of the counterweights 111, it is called an increased stage state, and when the number of stages is decreased from the standard number of stages of the counterweights 111, it is called a decreased stage state.

[0027] When the counterweights 111 are stacked in the standard six stages, as shown in Figure 6, the base member 51 of the camera support unit 50 is fixed to the top surface of the counterweight 111 using the attractive force of the magnet 51c. In this case, only the reference bracket 52A is fixed to the base member 51, and the camera 13 is attached to the upper holding portion 52a of this reference bracket 52A. In addition, the unused selection bracket 52B is supported in a horizontal position by the base member 51. Here, if the mounting height of the camera 13 at this position is taken as the reference height H, then the reference height H is equivalent to six stages of the thickness dimension (= h) of one counterweight 111, so H ≈ 6h.

[0028] A connection cable 53 is attached to the camera 13, and this connection cable 53 passes over the top surface of the uppermost counterweight 111 and is connected to a controller 160 (see FIG. 1). The controller synthesizes a surround view image based on the image information from the four cameras 10, 11, 12, and 13, and displays the image on a display device 231 in the driver's cab 109.

[0029] As shown in Figure 7, when one counterweight 111 is added to the standard number of steps to create an increased-step state, the base member 51 of the camera support unit 50 is fixed to the upper surface of the counterweight 111 of the topmost step (seventh step). In this case, if the camera 13 remains attached to the upper holding portion 52a of the reference bracket 52A, the mounting position of the camera 13 will be higher by the thickness h of the added counterweight 111. Therefore, the camera 13 is attached to the lower holding portion 52a of the reference bracket 52A. As a result, the mounting position of the camera 13 is lower than the base member 51 by the thickness h of the counterweight 111, so the camera 13 can be properly mounted at the reference height H regardless of whether the counterweight 111 is added.

[0030] Furthermore, when the number of counterweights 111 is reduced from the standard number of steps to create a reduced-step state, for example, when three steps are reduced from the standard number to create a three-step load of counterweights 111, the base member 51 of the camera support unit 50 is fixed to the top surface of the counterweight 111 of the uppermost step (third step), and three selection brackets 52B are connected to the upper end of the reference bracket 52A by bolting their connecting portions 52b together, as shown in Fig. 8. This forms three sets of holding portions 52a arranged at intervals equivalent to the thickness of the counterweight 111 above the reference bracket 52A (see Fig. 5). Therefore, by attaching the camera 13 to the holding portion 52a of the selection bracket 52B of the uppermost step, the camera 13 can be appropriately attached to the reference height H regardless of whether the number of counterweights 111 is reduced.

[0031] If the number of load stages of the counterweight 111 is reduced by one from the standard number of stages to five, the camera 13 can be properly installed at the reference height H by connecting one selection bracket 52B to the upper end of the reference bracket 52A and attaching the camera 13 to the holding portion 52a of this selection bracket 52B. If the number of load stages of the counterweight 111 is reduced by two from the standard number of stages to four, the camera 13 can be properly installed at the reference height H by connecting two selection brackets 52B to the upper end of the reference bracket 52A and attaching the camera 13 to the holding portion 52a of the upper selection bracket 52B.

[0032] As described above, in the crane 100 according to this embodiment, the camera support unit 50 mounted on the counterweight 111 comprises a base member 51 placed on the counterweight 111, a holding portion 52a that holds the camera 13 at the reference height H, and a bracket 52 (position adjustment means) that can adjust the height of the holding portion 52a relative to the base member 51 to approach the reference height H regardless of whether the number of stages of the counterweight 111 increases or decreases. Therefore, the mounting position of the camera 13 can be suitably adjusted to the reference height H in response to changes in the number of stages of the counterweight 111.

[0033] In addition, the bracket 52, which is a position adjustment means, consists of a reference bracket 52A fixed to the base member 51 so as to extend vertically, and a plurality of selection brackets 52B that can be connected to the upper end of the reference bracket 52A, and since a holding portion 52a is formed on each of these reference brackets 52A and selection brackets 52B, the height of the holding portion 52a to which the camera 13 is attached can be appropriately adjusted for each step of the counterweight 111.

[0034] Furthermore, the reference bracket 52A and the selection bracket 52B can be attached and detached in the vertical direction by fixing each other's connecting parts 52b with fasteners such as bolts, so that the reference bracket 52A and the selection bracket 52B can be easily secured to lengths appropriate for the number of stages of the counterweight 111.

[0035] In this embodiment, the counterweight 111 has six standard steps and the number of steps can be increased or decreased by three, and three selection brackets 52B are used, but the present invention is not limited to this. The counterweight 111 may have any number of adjustable steps. For example, if a usage scenario is envisioned in which the number of steps of the counterweight 111 is increased or decreased by only one step, the configuration of the brackets 52 (i.e., the number and length) can be adjusted to accommodate this increase or decrease in the number of steps. Furthermore, by preparing the same number of brackets 52 as the standard number of steps of the counterweight 111, any increase or decrease in the number of steps of the counterweight 111 can be accommodated.

[0036] Next, a modified example of the camera support unit will be described.

[0037] Fig. 9 is a perspective view of the camera support unit 60 according to Modification 1, as seen from the rear. Fig. 10 is a perspective view of the camera support unit 60 according to Modification 1, as seen from the front.

[0038] As shown in Figures 9 and 10, the camera support unit 60 of variant example 1 includes a base member 54 attached to the counterweight 111, a support pillar 55 functioning as a position adjustment means, and a holding member 56 functioning as a holding portion.

[0039] The base member 54 is formed in a flat plate shape and has magnets 54a at the four corners of its lower surface. The base member 54 is detachably attached to the upper surface of the counterweight 111 using these magnets 54a.

[0040] The support pillar 55 is made of an angled bar with an L-shaped cross section and is fixed to the upper surface of the base member 54 so as to extend vertically. The support pillar 55 has multiple pairs of mounting holes 55a (for example, three pairs) formed in the support pillar 55 at predetermined intervals in the vertical direction. The spacing between the mounting holes 55a in each pair is set according to the thickness of the counterweight 111 to be loaded. As will be described later, the counterweight 111 on which the camera support unit 60 according to Modification 1 is mounted has the uppermost counterweight 111 having a recess in the center of its top surface. Therefore, the spacing between the mounting holes 55a in the lower and middle rows is set narrower than the spacing between the mounting holes 55a in the upper and middle rows. Note that if all the camera support units 60 are loaded on counterweights 111 of the same thickness, the spacing between the mounting holes 55a in each pair can be set approximately equal to the thickness of the counterweight 111.

[0041] The camera 13 is fixed to one end of the holding member 56, and an attachment portion 56a is formed on the other end of the holding member 56. The holding member 56 is fixed to the support 55 at a predetermined height so as to be perpendicular to the axis thereof by connecting the attachment portions 56a to a set of mounting holes 55a of the support 55 using fasteners such as bolts. This allows the camera 13 to be mounted at the highest level of the support 55 (see FIG. 9) or at the lowest level of the support 55 (see FIG. 10).

[0042] Fig. 11 is a perspective view showing a state in which the camera support unit 60 according to Modification 1 is installed on a counterweight 111 with a standard number of steps. Fig. 12 is a perspective view showing a state in which the camera support unit 60 according to Modification 1 is installed on a counterweight 111 with a reduced number of steps.

[0043] The camera support unit 60 according to the first modification is mounted on a counterweight 111 having, for example, four standard stages. As shown in Fig. 11, a recess 111a is provided in the center of the top surface of the uppermost counterweight 111, and the base member 54 of the camera support unit 60 is fixed to the upper surface of the recess 111a by utilizing the attractive force of a magnet 54a. In this case, the holding member 56 is connected to the mounting hole 55a in the lowermost stage of the support column 55 (see Fig. 9), and the camera 13 fixed to the holding member 56 is held at a reference height.

[0044] As shown in Figure 12, when the number of counterweights 111 loaded is reduced from the standard number of levels to two, the base member 54 of the camera support unit 60 is fixed to the flat upper surface of the counterweight 111 of the uppermost level (second level), and the holding member 56 is connected to the mounting hole 55a of the uppermost level of the support 55 (see Figure 10). As a result, the height of the holding member 56 increases by an amount equivalent to the thickness of the counterweights 111 of the uppermost and second levels in Figure 11, so the camera 13 can be properly attached at the standard height regardless of whether the counterweights 111 are reduced in number.

[0045] Furthermore, if the number of counterweights 111 loaded is reduced by one from the standard number of steps to three, the camera 13 can be properly mounted at the reference height by connecting the holding member 56 to the mounting hole 55a in the middle step of the support 55.

[0046] In the first variant configured in this manner, the camera support unit 60 mounted on the counterweight 111 comprises a base member 54 attached to the counterweight 111, a support pillar 55 fixed to the upper surface of the base member 54 so as to extend vertically, and a holding member 56 that holds the camera 13 at a reference height. The support pillar 55 has a plurality of mounting holes 55a formed in it that are spaced apart at intervals equivalent to the thickness of the counterweight 111. Therefore, by selectively connecting the holding member 56 to one set of the mounting holes 55a, the mounting position of the camera 13 can be suitably adjusted to the reference height in response to changes in the number of steps of the counterweight 111.

[0047] In camera support unit 60 according to Modification 1, the number of mounting holes 55a formed in support column 55 is not limited to three, and the number of mounting holes 55a corresponding to the reference height of camera 13 is not limited to the lowest one. For example, if four sets of mounting holes 55a are formed in support column 55 and the second-lowest mounting hole 55a corresponds to the reference height of camera 13, the mounting position of camera 13 can be suitably adjusted to the reference height even if counterweight 111 is increased by one step or decreased by three steps relative to the standard number of steps of counterweight 111.

[0048] Fig. 13 is a perspective view showing a state in which the camera support unit 60 according to Modification 1 is installed on a counterweight 111 with a groove. Fig. 14 is a perspective view showing a state in which the camera support unit 60 according to Modification 1 is installed on a counterweight 111 at the intermediate stage.

[0049] 13, the base member 54 of the camera support unit 60 is fixed to the rear surface of the second-stage counterweight 111, and a groove 111b is provided on the top surface of the second-stage counterweight 111, which is the intermediate stage (specific stage). The camera 13 is held on the top stage of the support column 55, and the connection cable 53 leading out from the camera 13 passes through the groove 111b and is connected to the controller.

[0050] If such a groove 111b is provided in the counterweight 111 of the middle tier, when the number of counterweights 111 loaded is increased to, for example, four tiers, as shown in Figure 14, the connection cable 53 can be routed through the groove 111b located between the counterweights 111 of the second and third tiers.

[0051] Figure 15 is a perspective view showing the main parts of the camera support unit according to Modification 2. As shown in Figure 15, a handrail 112 is erected on the uppermost counterweight 111, and this handrail 112 has a center pole 112a extending in the vertical direction. A plurality of mounting holes 112b are formed in the center pole 112a as position adjustment means for the camera support unit according to Modification 2, and although not shown, a holding member to which the camera 13 is fixed is connected to these mounting holes 112b.

[0052] In the modified example 2 configured in this manner, the center pole 112a of the handrail 112 erected on the top counterweight 111 has a plurality of mounting holes 112b formed therein that function as position adjustment means, so that the mounting position of the camera 13 can be suitably adjusted to the reference height regardless of whether the number of stages of the counterweight 111 is increased or decreased.

[0053] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed in this specification, and these are included in the technical scope described in the appended claims.

[0054] For example, in the above embodiment and modified examples, the height position of the camera 13 can be adjusted in stages along the vertical direction, but the height of the holding part may also be adjusted by sliding movement or a pantograph method.

[0055] Furthermore, in the above embodiment and modified example, the camera 13 is described as being compatible with surround view, but the present invention is not limited to this, and a dedicated camera for monitoring the rear of the counterweight 111 may also be used.

[0056] Furthermore, with regard to the position adjustment means according to the modified example, as with the above embodiment, the range in which the camera position can be adjusted may be a part or all of the range in which the number of stages of the counterweight 111 is increased or decreased. Furthermore, in the above embodiment and modified example, the base member 51 is installed on the second stage, which is the middle stage of the counterweight 111, but the base member 51 can be installed on a specific stage other than the top stage of the counterweight 111. Therefore, the base member 51 may be installed on the bottom stage of the counterweight 111. Furthermore, although the base member 51 is installed on the top surface of the counterweight 111, the installation surface may be an outer surface other than the top surface. For example, the base member 51 may be provided on the back, side, or bottom surface of the counterweight 111. Similarly, the groove 111b may be provided on an outer surface other than the top surface of the counterweight 111. [Explanation of symbols]

[0057] 10, 11, 12 Camera 13 Rear camera 50,60 Camera support unit 51 Base material 51a base 51b Support part 51c Magnet 52 Bracket 52A Reference Bracket 52B Selection Bracket 52a Holding part 52b Connection part 52c Mounting hole 53 Connection cable 54 Base material 54a Magnet 55 Post 55a Mounting hole 56 Retaining member 56a Mounting part 100 Crane 101 Running body 103 Rotating body 104 Boom 109 Driver's Cab 111 Counterweight 111a recess 111b Groove 112 Handrail 112a Center Pole 112b Mounting hole

Claims

1. In a crane capable of loading multiple levels of counterweights, a camera that captures an image behind the counterweight; a base member attached to the counterweight; a holder that holds the camera at a reference height; a position adjusting means for adjusting the height of the holding portion relative to the base member so as to approach the reference height regardless of whether the number of stages of the counterweight is increased or decreased; A crane characterized by comprising:

2. The crane of claim 1, The position adjusting means is capable of adjusting the height of the holding portion for each step of the counterweight. A crane characterized by:

3. The crane according to claim 2, The base member is attached to the upper surface of the counterweight located at the uppermost stage. A crane characterized by:

4. The crane according to claim 2, The base member is attached to the outer surface of the counterweight located at a specific stage other than the top stage, a groove for accommodating a connection cable leading out from the camera is provided in the counterweight located at the specific stage; A crane characterized by:

5. The crane of claim 1, A handrail is provided upright on the counterweight, The position adjustment means is attached to the handrail. A crane characterized by:

6. The crane of claim 1, the position adjustment means includes a support column attached to the base member in a vertical direction, The holding portion can be fixed to the support at a plurality of height positions. A crane characterized by:

7. The crane of claim 1, The position adjustment means includes a plurality of brackets and a fixing means for detachably connecting the plurality of brackets in the vertical direction. A crane characterized by:

8. 8. The crane of claim 7, The holding portion is provided on each of the plurality of brackets. A crane characterized by:

9. 8. The crane of claim 7, The length of each of the plurality of brackets is set to a length corresponding to the thickness of one stage of the counterweight. A crane characterized by:

10. 8. The crane of claim 7, The base member is capable of supporting the bracket when not in use among the plurality of brackets. A crane characterized by:

11. A camera support unit that is mounted on a crane capable of loading a plurality of stages of counterweights and supports a camera that captures an image behind the counterweight, a base member attached to the counterweight; a holder that holds the camera at a reference height; a position adjusting means for adjusting the height of the holding portion so as to approach the reference height regardless of an increase or decrease in the number of stages of the counterweight; A camera support unit comprising:

Images