JP6258633B2 - Cable winding device for construction machinery and telescopic boom device for construction machinery - Google Patents

Description

  The present invention relates to a cable winding device for a construction machine that winds a conductive cable. In particular, the present invention relates to a construction machine cable winding device that can handle a conductive cable having a large number of core wires, and a construction machine telescopic boom device including the construction machine cable winding device.

  Telescopic boom devices are used in various construction machines such as crawler cranes and aerial work platforms. For example, as shown in FIG. 11, a telescopic boom device described in Patent Document 1 below is used in a truck crane 101, in which an upper boom 113 is slidable with respect to a middle boom 112, and the middle boom 112 is lower boom. 111 is slidable.

  In the telescopic boom device 110, the cable reel 130 is attached to the lower boom 111, and the leading end of the conductive cable 120 drawn from the cable reel 130 is attached to the upper boom 113. And according to expansion and contraction of the telescopic boom device 110, the conductive cable 120 is unwound or wound by the cable reel 130. In this way, the conductive cable 120 stretched over can ensure the energization of the lower boom 111 and the upper boom 113, and can be electrically exchanged between the two.

  Incidentally, the cable reel 130 is configured in detail as shown in FIG. That is, the cable reel 130 is rotatably attached to the support shaft 140 to wind the conductive cable 120, the spring 170 that biases the drum 150 in the winding direction, and the outer end portion of the support shaft 140. The electric rotary joint device 180 is coaxially arranged around the 140a.

  The electric rotary joint device 180 includes a plurality of slip rings 181 attached to the outer end portion 140 a of the support shaft 140, an insulator 182 interposed between the slip rings 181, and the slip rings 181. And a plurality of brushes 183 arranged correspondingly and constantly biased to contact the slip ring 181. In addition, one end of each core wire of the conductive cable 120 is connected to each brush 183, and each core wire of the introduction cable 121 that passes through the support shaft 140 is connected to each slip ring 181.

  In the cable reel 130 configured as described above, when the telescopic boom device 110 is extended, the conductive cable 120 is unwound from the drum 150 against the biasing force of the spring 170, and when the telescopic boom device 110 is contracted, the conductive cable is retracted. 120 is wound around the drum 150 by the biasing force of the spring 170. Thus, the drum 150 rotates when the conductive cable 120 is unwound or wound by the telescopic boom device 110 extending and retracting. However, even if the drum 150 rotates, the contact between the brush 183 and the slip ring 181 is maintained, so that the energization between the conductive cable 120 and the introduction cable 121 can be maintained.

JP 7-330225 A

  By the way, the present applicant has devised a telescopic boom device in which a large number of sensors, switches, and the like are arranged to increase electrical exchange. However, in this case, the number of the core wires of the conductive cable (hereinafter referred to as “the number of cores”) is as large as 12, for example. For this reason, if an attempt is made to manufacture a cable reel that can accommodate a conductive cable having a large number of cores, the number of brushes and slip rings to which the core wires are connected increases, and the width H of the cable reel (electric rotary joint device) (FIG. 12). (See) increases. As a result, even if an attempt is made to use a cable reel that has been manufactured for a telescopic boom device, the construction machine may be used even in a narrow space, and thus may not be used in a narrow space. Further, if the number of cores is large, there is a high possibility that a contact failure of the brush will occur, and there is a possibility that it cannot be energized. Thus, a new cable winding device to replace the cable reel has been demanded.

  Accordingly, the present invention has been made to solve the above-described problems, and can cope with a conductive cable having a large number of cores and can surely prevent a situation in which it cannot be energized. It is an object of the present invention to provide a telescopic boom device for a construction machine provided with the cable winding device.

A cable take-up device for a construction machine according to the present invention is applied to a telescopic boom device for a construction machine that includes a plurality of cylindrical booms that are slidably overlapped. One end is attached to the slide-side boom and the other end is attached to the slide-side boom to wind up a conductive cable that secures energization between the fixed-side boom and the slide-side boom, and is fixed to the fixed-side boom. A fixed sheave wound around one end of the conductive cable, a guide member attached to the fixed boom and extending in a sliding direction of the boom, and slidably attached to the guide member. A slide-side sheave wound around the other end, and is interposed between the slide-side sheave and the fixed-side sheave, A spring for urging in a direction away from Jogawa sheaves, and having a.
The telescopic boom device for a construction machine according to the present invention includes a plurality of cylindrical booms that are slidably overlapped with each other, and one of the two booms that slide relative to each other is attached to the slide-side boom, and is fixed to the fixed-side boom. The other end part is attached, The electrically conductive cable which ensures electricity supply with the said slide side boom and the said fixed side boom, and the cable winding apparatus for construction machines which concerns on this invention mentioned above, It is characterized by the above-mentioned.

According to the present invention, the sliding sheave slides along the guide member according to the telescopic boom device expansion and contraction, and the conductive cable is unwound from the sliding sheave and the stationary sheave, or the sliding sheave and the stationary sheave. Rolled up. And the state where the conductive cable is always stretched by the urging force of the spring can be maintained. Thus, the conductive cable can be wound and unwound without using a cable reel, and energization between the slide-side boom and the fixed-side boom can be ensured.
And since it is not the structure which uses a brush and a slip ring, even if it uses a conductive cable with many cores, the width | variety of a cable winding apparatus does not become large. Furthermore, it is possible to surely prevent a situation in which current cannot be supplied due to poor contact of the brush.

In the construction machine cable winding device or the construction machine telescopic boom device according to the present invention, the fixed sheave preferably has a diameter smaller than that of the slide sheave.
In this case, even if the telescopic boom device is extended, the conductive cable can be reliably prevented from coming into contact with the stationary sheave.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to respond | correspond to a conductive cable with many cores, the situation where it becomes impossible to energize can be prevented reliably, and the cable winding apparatus for construction machines with a narrow width | variety can be provided. Furthermore, a telescopic boom device for a construction machine provided with this cable winding device can be provided.

It is the side view which showed the crawler crane provided with the telescopic boom apparatus of this embodiment. It is the side view which showed the state which the telescopic boom apparatus of this embodiment has contracted. It is the side view which showed the state which the telescopic boom apparatus of this embodiment is extending | stretching. It is the figure which showed the electrically conductive cable. (A) It is the side view which showed the cable winding apparatus when the telescopic boom apparatus is shrink | contracting. (B) It is a top view of the cable winding apparatus shown to FIG. 5 (A). (A) It is an enlarged view of the fixed side sheave shown in FIG. (B) It is the figure which looked at the fixed sheave shown in Drawing 6 (A) from the top. (C) It is sectional drawing which looked at the fixed sheave shown in Drawing 6 (A) from the right. (A) It is an enlarged view of the slide side sheave shown in FIG. (B) It is sectional drawing which looked at the slide side sheave shown in FIG. 7 (A) from the top. (C) It is the figure which looked at the slide side sheave shown in Drawing 7 (A) from the right. FIG. 6 is an enlarged cross-sectional view of the spring shown in FIG. (A) It is the side view which showed the cable winding apparatus when the telescopic boom apparatus is extending | stretching. FIG. 10B is a top view of the cable winding device shown in FIG. FIG. 10 is an enlarged view of the fixed sheave and the slide sheave shown in FIG. It is the side view which showed the truck crane provided with the conventional telescopic boom apparatus. It is a figure for demonstrating the structure of the cable reel shown in FIG.

  DESCRIPTION OF EMBODIMENTS Embodiments of a cable device for construction machinery and a telescopic boom device for construction machinery according to the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a crawler crane 1 provided with a telescopic boom device 10 of the present embodiment. As shown in FIG. 1, in the crawler crane 1, an upper swing body 2 is provided so as to be capable of swinging with respect to a lower traveling body 3 by a crawler, and the upper swing body 2 includes a cab, a winch, a power device, and the like. Is provided.

  And the upper turning body 2 has the telescopic boom device 10 assembled on the front side, and the telescopic boom device 10 extends up and down from the horizontally extended state to the upside down state. Can do. Here, FIG. 2 is a diagram showing a state where the telescopic boom device 10 of the present embodiment is contracted, and FIG. 3 is a diagram showing a state where the telescopic boom device 10 of the present embodiment is extended. It is.

  The telescopic boom device 10 can be extended and contracted as shown in FIGS. 2 and 3, and three cylindrical booms having a rectangular cross section are coaxially overlapped. Of these three booms, the thickest boom is called the lower boom 11 in the order close to the upper swing body 2, the middle boom is called the middle boom 12, and the thinnest boom is called the upper boom 13. To do. The middle boom 12 is inserted into the lower boom 11 and is slidable with respect to the lower boom 11, and the upper boom 13 is inserted into the middle boom 12 and is slidable with respect to the middle boom 12.

  Thus, the telescopic boom device 10 has a structure capable of two-stage expansion and contraction, and has two boom cylinders 14 and 15 for performing two-stage expansion and contraction inside. One boom cylinder 14 is a hydraulic cylinder that slides the middle boom 12 relative to the lower boom 11, and includes a cylinder tube 14a and a cylinder rod 14b. The rod side end of the cylinder tube 14a is pivotally attached to the middle boom 12 via a pin P1, and the tip of the cylinder rod 14b is pivotally attached to the lower boom 11 via a pin P2. Thus, the lower boom 11 and the middle boom 12 are expanded and contracted by the expansion and contraction of the boom cylinder 14.

  The other boom cylinder 15 is a hydraulic cylinder that slides the upper boom 13 relative to the middle boom 12, and includes a cylinder tube 15a and a cylinder rod 15b. The rod side end of the cylinder tube 15a is pivotally attached to the upper boom 13 via a pin P3, and the tip of the cylinder rod 15b is pivotally attached to the middle boom 12 via a pin P4. Thus, when the boom cylinder 15 is expanded and contracted, the middle boom 12 and the upper boom 13 are expanded and contracted.

  Here, in order to maintain the extended state of the lower boom 11 and the middle boom 12, the telescopic boom device 10 is provided with a lock mechanism 16 that couples the booms 11, 12 to each other, and the middle boom 12 and the upper boom 13. In order to maintain the extended state, a lock mechanism 17 that couples the booms 12 and 13 to each other is provided. In the pin coupling of these lock mechanisms 16 and 17, when the booms (11, 12) and (12, 13) are fully extended, the booms are stopped by a stopper structure (not shown). And the pin hole formed in each boom is piled up, and a lock pin is inserted in the pin hole.

  However, the impact force generated in the stopper structure when the booms 14 and 15 are extended by the extension of the boom cylinders 14 and 15 is large. Therefore, the telescopic boom device 10 uses a structure that reduces the impact force. That is, a plurality of limit switches 18 (see FIG. 3) for detecting the position immediately before the booms fully extend, and the hydraulic oil supplied to the boom cylinders 14 and 15 based on detection signals from these limit switches 18 are decompressed. A plurality of solenoid valves (not shown) are provided. In addition, a sensor is attached to the lock pin in order to grasp the lock pin insertion / extraction state at the driver's seat.

  In this way, in the telescopic boom device 10 of the present embodiment, a conductive cable having a large number of core wires is required in order to arrange a large number of limit switches 18 and sensors of the lock mechanisms 16 and 17 and perform electrical exchange. . However, this case has the following problems.

  Conventionally, the conductive cable 120 is wound or unwound by a cable reel 130 as shown in FIG. Here, if it is going to manufacture the cable reel 130 which can respond to the conductive cable 120 with many cores, it is necessary to connect many core wires to the brush 183 and the slip ring 181, and the brush 183 and the slip ring 181 increase. This increases the width H of the cable reel 130 (electric rotary joint device 180). As a result, even if the cable reel manufactured temporarily is used for the telescopic boom device 10, the crawler crane 1 may be used even in a narrow space, so there is a possibility that it cannot be used in a narrow space. In addition, if the number of cores is large, there is a high possibility that a contact failure of the brush will occur, and there is a possibility that energization cannot be performed or leakage occurs. Furthermore, a cable reel that can handle a conductive cable having a large number of cores is a custom-made product, which increases the cost.

  Therefore, in the present embodiment, the above-described problems are solved by using a new cable winding device that replaces the cable reel. Here, the conductive cable 20 used in this embodiment will be described. FIG. 4 is a diagram showing the conductive cable 20. The conductive cable 20 is a 12-core cable having 12 cores, for example, a vinyl cabtyre cord (VCTF). Connectors 21 are attached to both ends of the conductive cable 20. The conductive cable to be used is not limited to the conductive cable 20 having 12 cores, and a conductive cable having a multicore other than 12 cores may be used.

  Next, the configuration of the cable winding device of the present embodiment will be described. FIG. 5A is a side view showing the cable winding device 30 when the telescopic boom device 10 is contracted, and FIG. 5B is the cable winding device shown in FIG. FIG. Note that the cable winding device 30 is not shown in the side views of FIGS. 1 to 3 as seen in the side view of FIGS. 1 to 3 and the side view of FIG. 5 (A). This is because the direction is opposite.

  The cable winding device 30 is applied to the lower boom 11 and the middle boom 12, and winds up the conductive cable 20 that ensures energization between the middle boom 12 (slide-side boom) and the lower boom 11 (fixed-side boom). . The cable winding device 30 mainly includes a fixed sheave 40, a guide member 50, a slide sheave 60, and a spring 70. Hereinafter, each member 40 to 70 will be described. . 6A is an enlarged view of the fixed sheave 40 shown in FIG. 5A, and FIG. 6B is a view of the fixed sheave 40 shown in FIG. 6A as viewed from above. FIG. 6C is a cross-sectional view of the fixed sheave 40 shown in FIG. 6A viewed from the right.

  The fixed sheave 40 is fixed to the lower boom 11 and winds the conductive cable 20 on the one end 20a side (portion close to the one end 20a). Here, as shown in FIG. 5A, one end portion 20 a of the conductive cable 20 is attached to a support portion provided on the lower boom 11 via a connector 21. On the other hand, the other end portion 20 b of the conductive cable 20 is attached to a support portion provided on the middle boom 12 via a connector 21. As shown in FIGS. 6A, 6 </ b> B, and 6 </ b> C, the stationary sheave 40 mainly includes three sheave members 41, a bearing 42, a support shaft 43, and a pipe member 44. Has been.

  Each sheave material 41 is rotatably assembled to a support shaft 43 via a bearing 42, and is made of, for example, nylon so that the conductive cable 20 can be smoothly unwound and wound. One end of the support shaft 43 is fixed to the pipe material 44, and a nut 45 is screwed to the other end of the support shaft 43. The pipe member 44 has a cylindrical shape with a rectangular cross section, is assembled around the guide member 50, and is fixed so as not to move with respect to the guide member 50 by bolts 46 and nuts 47. Here, as shown in FIGS. 5A and 5B, the guide member 50 extends in the sliding direction of the booms 11 and 12 and has a cylindrical shape with a rectangular cross section (see FIG. 6B). It is attached to the lower boom 11 via a connecting member RK.

  Further, as shown in FIG. 6C, a plate 48 extending in the sliding direction (upward in FIG. 6C) is attached to the pipe member 44, and the plate 48 is orthogonal to the sliding direction. A plate 49 extending in the direction is attached. The conductive cable 20 is guided to the sheave material 41 side by the plate 49 so that the conductive cable 20 can be unwound and wound more smoothly.

  As shown in FIG. 5A, the slide-side sheave 60 is slidably attached to the guide member 50 and winds the other end 20b side (portion close to the other end 20b) of the conductive cable 20. is there. FIG. 7A is an enlarged view of the slide-side sheave 60 shown in FIG. 5A, and FIG. 7B is a cross-sectional view of the slide-side sheave 60 shown in FIG. FIG. 7C is a view of the slide sheave 60 shown in FIG. 7A viewed from the right. As shown in FIGS. 7A, 7 </ b> B, and 7 </ b> C, the slide-side sheave 60 mainly includes three sheave members 61, a bearing 62, a support shaft 63, and an annular member 64. ing.

  Each sheave material 61 is rotatably attached to a support shaft 63 via a bearing 62, and is made of, for example, nylon so that the conductive cable 20 can be smoothly unwound and wound. One end of the support shaft 63 is fixed to the annular member 64, and a nut 65 is screwed to the other end of the support shaft 63. The annular member 64 is configured to have a rectangular cross section, is assembled around the guide member 50, and is slidable along the guide member 50.

  As shown in FIG. 7C, a plate 66 extending in the sliding direction (downward in FIG. 7C) is attached to the annular member 64, and the plate 66 is orthogonal to the sliding direction. A plate 67 extending in the direction is attached. The conductive cable 20 is guided to the sheave material 61 by the plate 67 so that the conductive cable 20 can be unwound and wound more smoothly. Here, FIG. 8 is an enlarged cross-sectional view of the spring 70 shown in FIG.

  The spring 70 is interposed between the slide-side sheave 60 and the fixed-side sheave 40 and biases the slide-side sheave 60 in a direction away from the fixed-side sheave 40. That is, in the state shown in FIG. 5A, the spring 70 is assembled in a contracted state, and the conductive cable 20 wound around the slide-side sheave 60 and the fixed-side sheave 40 by the urging force of the spring 70. Is not loosened. The spring 70 surrounds the guide member 50, one end portion 70 a is engaged with the annular member 64 of the slide side sheave 60, and the other end portion 70 b is engaged with the pipe member 44 of the fixed side sheave 40. Yes.

  Thus, in the cable winding device 30, as shown in FIGS. 5A and 5B, the conductive cable 20 is bridged so as to reciprocate between the sliding sheave 60 and the stationary sheave 40 (six cables). The one end 20 a of the conductive cable 20 is attached to the lower boom 11, and the other end 20 b of the conductive cable 20 is attached to the middle boom 12. Then, the slide-side sheave 60 remains at that position against the urging force of the spring 70.

  Next, the operation of the cable winding device 30 will be described. FIG. 9A is a side view showing the cable winding device 30 when the telescopic boom device 10 is extended, and FIG. 9B is the cable winding device shown in FIG. 9A. FIG. As shown in FIGS. 9A and 9B, when the telescopic boom 10 is extended from the state shown in FIGS. 5A and 5B, the slide-side sheave 60 is moved to the right side of FIG. Slide toward. At this time, the spring 70 interposed between the slide-side sheave 60 and the fixed-side sheave 40 compresses, but the slide-side sheave 60 slides against the urging force of the spring 70, and the conductive cable 20 moves to the slide side. The sheave 60 and the fixed sheave 40 are unwound.

  On the other hand, as shown in FIGS. 5A and 5B from the state shown in FIGS. 9A and 9B, when the telescopic boom device 10 contracts, the slide-side sheave 60 is urged by the urging force of the spring 20 in FIG. The conductive cable 20 is wound around the slide-side sheave 60 and the fixed-side sheave 40 by sliding toward the left side. In this way, it is possible to ensure the energization of the lower boom 11 and the middle boom 12 by means of the conductive cable 20 that is always stretched, and to perform electrical exchange between the two. In this embodiment, the urging force of the spring 70 compressed when the telescopic boom 10 is extended is about 60 kgf. However, since six conductive cables 20 are hung by the cable winding device 30, 10 kgf, which is 1/6 of the urging force, acts. On the other hand, since the conductive cable 20 can withstand a tensile load of about 30 kgf, the conductive cable 20 can be used without any problem.

  By the way, in this cable winding device 10, the fixed-side sheave 40 (sheave material 41) has a diameter smaller than that of the slide-side sheave 60 (sheave material 61). Specifically, the diameter D1 of the sheave material 41 is set to about 230 mm, and the diameter D2 of the sheave material 61 is set to about 250 mm. The reason for this will be described with reference to FIG. FIG. 10 is an enlarged view of the fixed sheave 40 and the slide sheave 60 shown in FIG. As shown in FIG. 10, when the straight line L1 connecting the rotation center axis O1 of the fixed sheave 40 and the rotation center axis O2 of the slide side sheave 60 extends in exactly the same direction as the slide direction of the booms 11 and 12, the telescopic boom When the device 10 is extended, the conductive cable 20 approaches the fixed sheave 40 (sheave material 41) as shown by a one-dot chain line X in FIG. For this reason, the diameter D1 of the sheave material 41 is made smaller than the diameter D2 of the sheave material 61, so that the conductive cable 20 is not reliably brought into contact with the sheave material 41 even when the telescopic boom device 11 is extended. The diameter D1 of the sheave material 41 and the diameter D2 of the sheave material 61 can be appropriately changed.

The operational effects of the telescopic boom device 10 and the cable winding device 30 of the present embodiment will be described.
According to the present embodiment, the sliding sheave 60 slides along the guide member 50 according to the telescopic boom device 10 expansion and contraction, and the conductive cable 20 is unwound from the sliding sheave 60 and the stationary sheave 40, or It is wound around the sliding sheave 60 and the stationary sheave 40. The state in which the conductive cable 20 is always stretched by the urging force of the spring 70 can be maintained. Thus, the conductive cable 20 can be wound and unwound without using a cable reel (see FIG. 12), and the middle boom 12 and the lower boom 11 can be energized.

  And since it is not the structure which uses a brush and a slip ring, even if it uses the conductive cable 20 with many cores, the conductive cable 20 will only become thick, and the width | variety of the cable winding apparatus 30 will not become large. Furthermore, since there is no poor contact of the brush, it is possible to reliably prevent a situation where power cannot be supplied or a situation where current leakage occurs. Further, even when another conductive cable having a different number of cores is to be used, the cable winding device 30 can be used as it is and is a highly flexible device. Furthermore, since the cable winding device 30 is mainly composed of the fixed sheave 40, the guide member 50, the slide sheave 60, and the spring 70, it can be configured very simply and inexpensively.

As mentioned above, although the embodiment of the cable winding device for construction machines and the telescopic boom device for construction machines according to the present invention has been described, the present invention is not limited to this embodiment, and various modifications are possible without departing from the scope of the present invention. Changes are possible.
For example, in the present embodiment, the cable winding device 30 is applied to the lower boom 11 and the middle boom 12, but of course, it can also be applied to the middle boom 12 and the upper boom 13. Further, the telescopic boom device 10 is not limited to one that can be expanded and contracted in two stages, and can be appropriately changed as long as the structure includes a plurality of booms.

  In the present embodiment, the cable winding device 30 winds and unwinds the conductive cable 20 with two sheaves (the fixed sheave 40 and the slide sheave 60). Winding and unwinding may be performed with three or more sheaves. In this case, even if the stroke amount of the middle boom 12 with respect to the lower boom 11 is increased, it can be handled without changing the distance between the fixed sheave 40 and the slide sheave 60. Further, in the fixed sheave 40 and the slide sheave 60, the six conductive cables 20 are hung by the three sheave members 41 and 61, respectively, but the number of sheave members may be two or four or more. It can be changed as appropriate.

In the present embodiment, the diameter D1 of the sheave material 41 of the fixed sheave 40 is made smaller than the diameter D2 of the sheave material 61 of the slide-side sheave 60, so that the conductive cable 20 is sheaveed when the telescopic boom device 10 is extended. The material 41 was not touched. However, the fixed sheave 40 and the straight sheave 40 and the straight line L1 (see FIG. 10) connecting the rotation center axis O1 of the fixed sheave 40 and the rotation center axis O2 of the slide sheave 60 are inclined with respect to the sliding direction of the booms 11 and 12. By arranging the slide-side sheave 60, the conductive cable 20 may be prevented from contacting the sheave material 41. Further, if the conductive cable 20 does not contact the sheave material 41, the diameter D1 of the sheave material 41 and the diameter D2 of the sheave material 61 may be the same.
Moreover, although the telescopic boom apparatus 10 of this embodiment is applied to the crawler crane 1, the applied construction machine can be changed as appropriate, and may be a truck crane, an aerial work vehicle, or the like.

1 Crawler Crane 10 Telescopic Boom Device 11 Lower Boom 12 Middle Boom 13 Upper Boom 14, 15 Boom Cylinder 20 Conductive Cable 30 Cable Winding Device 40 Fixed Side Sheave 50 Guide Member 60 Slide Side Sheave 70 Spring

Claims (2)

Applied to telescopic boom equipment for construction machinery with multiple cylindrical booms slidably overlapping,
Of the two relatively sliding booms, one end is attached to the stationary boom and the other end is attached to the sliding boom, and a conductive cable is secured to ensure energization between the stationary boom and the sliding boom. In the cable take-up device for construction machinery to take,
A fixed sheave fixed to the fixed boom and wound around one end of the conductive cable;
A guide member attached to the fixed-side boom and extending in the boom sliding direction;
A slide-side sheave that is slidably attached to the guide member and winds the other end of the conductive cable;
A spring interposed between the slide-side sheave and the fixed-side sheave and biasing the slide-side sheave in a direction away from the fixed-side sheave ,
The fixed-side sheave is smaller in diameter than the slide-side sheave, so that the conductive cable does not reliably contact the fixed-side sheave even when the construction machine telescopic boom device is extended. A cable winder for construction machinery. A plurality of cylindrical booms slidably overlapping,
One of the two booms that slide relative to each other is attached to the stationary boom and the other end is attached to the sliding boom.
In a telescopic boom device for a construction machine comprising a cable winding device for winding the conductive cable,
The cable winding device is:
A fixed sheave fixed to the fixed boom and wound around one end of the conductive cable;
A guide member attached to the fixed-side boom and extending in the boom sliding direction;
A slide-side sheave that is slidably attached to the guide member and winds the other end of the conductive cable;
A spring interposed between the slide-side sheave and the fixed-side sheave and biasing the slide-side sheave in a direction away from the fixed-side sheave ,
The slide-side sheave has a diameter smaller than that of the fixed-side sheave, so that the conductive cable does not reliably contact the fixed-side sheave even when the construction machine telescopic boom device is extended. A telescopic boom device for construction machinery.

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