JP2018052673A - Reclaimer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reclaimer comprising an electric cylinder as elevation means of a boom, the reclaimer avoiding overload applied to the electric cylinder without control by control means when impact is added to the boom to lower its tip, and automatically returning an operation of the electric cylinder.SOLUTION: A reclaimer comprises an electric cylinder that elevates a boom, and a driving mechanism of a rod of the electric cylinder has an electric motor, a reduction gear that amplifies an output torque of the electric motor, a motion conversion device that converts a rotation output of the reduction gear into reciprocation movement of the rod, and a mechanical friction clutch that is provided on a power transmission path between the electric motor and the reduction gear and slips when a torque equal to or larger than a predetermined set torque is applied, the predetermined set torque being larger than the rated torque of the electric motor and smaller than the maximum torque of the electric motor.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reclaimer (including a stacker reclaimer).

  Conventionally, loose objects such as landed ore and coal are stored in a stock yard having a large area. The stock yard is provided with a stacker as a loading means and a reclaimer as a payout means. A stacker / reclaimer having both functions of a stacker and a reclaimer may be provided.

  The stacker is provided with a conveyor for transporting loose articles, and the bulk articles are loaded into a stock yard and stacked. The reclaimer includes a boom that can be horizontally swung and raised and lowered, a bucket wheel that is provided at the tip of the boom, and a boom conveyor that is provided along the boom. Scrap off, and use the boom conveyor to deliver the bulk material from the pile to the designated place. Patent Document 1 discloses this type of reclaimer.

  The reclaimer described in Patent Document 1 includes an electric motor-operated electric cylinder using a ball screw as a boom lifting device instead of a conventional hydraulic cylinder. In this way, when the electric cylinder is used as the boom lifting device, unlike the hydraulic system that can buffer the impact by the function of the safety valve when a large impact load due to excavation impact or collapse of mountain piles is applied to the bucket wheel, The cylinder may be overloaded and the electric cylinder may be damaged.

  Therefore, the reclaimer described in Patent Literature 1 stops the electric motor that drives the electric cylinder when the load cell that detects a load acting on the electric cylinder detects a load of a predetermined level or more, and further decelerates from the electric motor. The mechanical brake provided in the power transmission path to the machine slips and the retracting operation of the rod is allowed.

JP 2013-170045 A

  In the reclaimer of the above-mentioned patent document 1, when the load cell detects erroneously or communication failure between the load cell and the electric cylinder control device occurs, the function for avoiding the overload applied to the electric cylinder does not operate.

  The present invention has been made in view of the above circumstances, and an object of the present invention is a reclaimer including an electric cylinder as a boom raising and lowering means when an impact is applied to the boom to lower the tip. An object of the present invention is to provide an apparatus in which an overload applied to the electric cylinder without being controlled by the control means is avoided and the operation of the electric cylinder is automatically restored.

  A reclaimer according to an aspect of the present invention includes a traveling machine body, a swivel provided on the traveling machine body so as to be horizontally swivelable, a boom having a base end connected to the swivel base so as to be able to be lifted, and the swivel base A rod having a base end connected to the rod, a rod inserted into the cylinder and having a tip connected to the boom, and a drive mechanism for driving the rod forward and backward with respect to the cylinder. And an electric cylinder for raising and lowering the boom. The drive mechanism includes an electric motor, a speed reducer that amplifies the output torque of the electric motor, a motion conversion device that converts a rotational output of the speed reducer into a forward / backward movement of the rod, the electric motor, and the speed reducer A mechanical friction clutch that is provided in a power transmission path to and from the device and slips when a torque greater than a predetermined set torque greater than a rated torque of the electric motor and smaller than a maximum torque of the electric motor is applied. It is characterized by having.

  In the reclaimer configured as described above, when an impact is applied to the boom to lower the tip side, the friction clutch slips if a large torque greater than the set torque is applied to the friction clutch in order to contract the rod. Thereby, shortening of the rod is allowed and the rod and the cylinder are protected. Further, when the friction clutch slips, the torque transmission rate of the torque transmitted from the reduction gear to the electric motor is reduced, and an excessive load is prevented from being input to the electric motor, thereby protecting the electric motor. When the excessive load is eliminated, the torque transmission rate of the friction clutch is automatically restored, and the reclaimer can be operated as usual.

  In the reclaimer, the electric motor is configured to output rotational power to the electric motor when the tip of the boom is raised, and to generate electric power with the rotational power input to the electric motor when the tip of the boom is lowered. A control unit for controlling the operation of the motor may be further provided.

  As a result, when an impact to lower the tip side is applied to the reclaimer boom, the energy of the impact is dissipated by the power generation by the electric motor in addition to the shortening of the rod and the slip of the friction clutch. The time required for recovery can be shortened.

  According to the present invention, it is possible to provide a reclaimer provided with an electric cylinder as a boom raising / lowering means, which avoids an overload applied to the electric cylinder without being controlled by the control means and automatically recovers.

FIG. 1 is a side view of a reclaimer according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of the electric cylinder. FIG. 3 is a schematic configuration diagram of a drive mechanism of the electric cylinder. FIG. 4 is a cross-sectional view showing a schematic configuration of the friction clutch.

  Next, embodiments of the present invention will be described with reference to the drawings. Here, an embodiment in which the present invention is applied to a reclaimer will be described. However, the present invention can also be applied to a stacker / reclaimer having both functions of a reclaimer and a stacker.

  FIG. 1 is a side view of a reclaimer 1 according to an embodiment of the present invention. As shown in FIG. 1, the reclaimer 1 includes a traveling machine body 2 that travels on a rail (not shown), a swivel base 3 that swivels horizontally on the traveling machine body 2, and a boom 4 that is supported on the swivel base 3 so as to be able to be raised and lowered. And an electric cylinder 5 as an elevating means for raising and lowering the boom 4, a counterweight 9 supported by the swivel base 3, and a cabin 6 supported by the swivel base 3. A cockpit is provided inside the cabin 6.

  The base end portion of the boom 4 is supported by the swivel base 3 so as to be able to be raised and lowered. A counterweight beam extending on the opposite side of the boom 4 is provided at the base end portion of the boom 4. The counterweight beam is provided with a counterweight 9. A boom conveyor 8 that conveys loose objects along the boom 4 from the distal end portion to the proximal end portion of the boom 4 is provided. The boom conveyor 8 includes an endless conveyor belt extending along the boom 4 and a drive device (not shown) that drives the conveyor belt. A bucket wheel 7 is provided at the tip of the boom 4. The bucket wheel 7 includes a foil, a plurality of buckets provided around the foil, and a drive device (not shown) that rotationally drives the foil.

  The electric cylinder 5 includes a cylinder 51, a rod 52 inserted into the cylinder 51, and a drive mechanism 53 that drives the rod 52 forward and backward from the cylinder 51.

  A lower end portion of the cylinder 51 is rotatably connected to a side portion of the swivel base 3 by a support shaft 32 extending in the horizontal direction. The upper end portion of the rod 52 is rotatably connected to the lower portion of the boom 4 by a support shaft 42 extending in the horizontal direction. The cylinder 51 and the rod 52 support the boom 4 in such a manner that it is stretched between the swivel base 3 and the boom 4. When the rod 52 advances from the cylinder 51, that is, when the rod 52 extends, the boom 4 rotates upward so that the tip of the boom 4 rises. Further, when the rod 52 retreats to the cylinder 51, that is, when the rod 52 contracts, the boom 4 is rotated downward so that the tip of the boom 4 is lowered.

  FIG. 2 is a schematic configuration diagram of the electric cylinder 5. As shown in FIG. 2, the drive mechanism 53 of the electric cylinder 5 includes two electric motors 61, and two drive systems from each electric motor 61 to the rod 52 are formed. That is, the drive mechanism 53 has redundancy. Normally, one of the two drive systems operates, and when a problem occurs in one of the drive systems, the other drive system operates instead of the one drive system. Since the two drive systems have substantially the same configuration, one of the two drive systems will be described below, and the description of the other will be omitted.

  FIG. 3 is a schematic configuration diagram of the drive mechanism 53 of the electric cylinder 5. In this figure, one of the two drive systems formed in the drive mechanism 53 is shown. As shown in FIG. 3, the drive mechanism 53 includes an electric motor 61, a speed reduction device 62, a motion conversion device 63, and a friction clutch 64.

  The electric motor 61 is an electric motor 61 with a brake device 65. However, the electric motor 61 and the brake device 65 that brakes the electric motor 61 may be independent. The rotation speed and rotation direction of the electric motor 61 are controlled by a control unit 66 having an inverter.

  The output of the electric motor 61 is input to the speed reducer 62. The transmission shaft 71 output from the electric motor 61 is parallel to the forward / backward direction of the rod 52. The transmission shaft 71 and the transmission shaft 72 that inputs the output from the electric motor 61 to the speed reducer 62 are connected via a mechanical friction clutch 64. The set torque of the friction clutch 64 is a value in a range larger than the rated torque of the electric motor 61 and smaller than the maximum torque of the electric motor 61, and is set in the friction clutch 64 in advance. The rated torque is a torque when the electric motor 61 continuously outputs a rated output at a rated voltage and a rated frequency, and the maximum torque is in an unstable region when a load higher than the torque is applied. Torque to stop entering. The rated torque and the maximum torque are values specific to the electric motor 61. The set torque of the friction clutch 64 is desirably a value of about 120 to 130% of the rated torque in order to avoid the friction clutch 64 from slipping due to the rated torque of the electric motor 61.

  As the mechanical friction clutch 64, for example, a torque limiter coupling may be employed. The torque limiter coupling is a shaft coupling provided with a torque limiter. When the transmission shaft 72 is less than the set torque, rotation is transmitted between the transmission shaft 71 and the transmission shaft 72, and the transmission shaft 72 exceeds the set torque (that is, At the time of overload, the torque transmission rate from the transmission shaft 72 to the transmission shaft 71 decreases due to slipping of the torque limiter. When the overload is eliminated, that is, when the torque of the transmission shaft 72 becomes less than the set torque, the torque transmission rate between the transmission shaft 71 and the transmission shaft 72 is automatically restored.

  FIG. 4 shows a schematic configuration of a known torque limiter coupling. For example, as shown in FIG. 4, the torque limiter coupling as an example of the friction clutch 64 includes a sprocket 81 that rotates integrally with the transmission shaft 71, a torque limiter 82 provided on the transmission shaft 72, A roller chain 83 that connects the torque limiter 82 may be used. The torque limiter 82 includes, for example, a boss 84 fitted to the transmission shaft 72, a sprocket 85 loosely fitted to the outer periphery of the boss 84, and a pair of friction plates 86 that sandwich the sprocket 85 from both sides in the axial direction of the transmission shaft 72. And a disc spring 87 that presses the pair of friction plates 86 against the sprocket 85 so that friction is generated between the sprocket 85 and the pair of friction plates 86. The sprocket 85 and the sprocket 81 are connected by a roller chain 83. In the torque limiter 82 configured as described above, if the torque of the transmission shaft 72 is less than the set torque, the boss 84 and the sprocket 85 are integrally rotated by the frictional force generated between the pair of friction plates 86 and the sprocket 85, and the transmission shaft Rotation is transmitted between 72 and the transmission shaft 71. On the other hand, when a torque greater than the set torque is applied to the transmission shaft 72, the sprocket 85 slips with respect to the pair of friction plates 86, and the torque transmission rate between the transmission shaft 71 and the transmission shaft 72 decreases. The friction clutch 64 is not limited to the torque limiter coupling having the above configuration.

  The reduction gear 62 amplifies and outputs the torque of the rotational power input from the transmission shaft 72. The output of the speed reduction device 62 is input to the motion conversion device 63. The electromagnetic clutch 75 may be provided in the speed reduction device 62, the power transmission path from the speed reduction device 62 to the motion conversion device 63, or the motion conversion device 63. By switching the electromagnetic clutch 75, one of the two drive systems is connected to the rod 52.

  The motion converter 63 converts the rotational output of the speed reducer 62 into a linear reciprocating motion of the rod 52. The motion conversion device 63 may include, for example, a ball screw mechanism including a ball circulation type screw screw and a ball screw having a nut fixed to the rod 52. In this ball screw mechanism, when the screw screw receives rotational power from the speed reducer 62 and rotates, the nut moves on the screw screw and the rod 52 moves forward and backward from the cylinder 51. Furthermore, when the axial direction of the speed reducer 62 and the axial direction of the screw screw are parallel as in the present embodiment, the motion conversion device 63 includes a gear train that transmits power between the parallel axes. It's okay.

  Further, the motion conversion device 63 may include, for example, a rack and pinion mechanism including a rack provided at the proximal end portion of the rod 52 and a pinion that meshes with the rack, instead of the above-described ball screw mechanism. In this rack and pinion mechanism, when the pinion is rotated by receiving the rotational power from the reduction gear 62, the pinion moves on the rack, and the rod 52 moves forward and backward from the cylinder 51. Note that the configuration of the motion conversion device 63 is not limited to the above example, and any configuration may be used as long as it includes a mechanism that converts the rotational output from the speed reduction device 62 into the linear reciprocating motion of the rod 52.

  In the reclaimer 1 having the above-described configuration, the boom 4 is turned by turning the swivel 3, and the boom 4 is lifted and lowered by the electric cylinder 5 as the lifting means, whereby the bucket wheel 7 provided at the distal end portion of the boom 4 is removed. Have access to piles of roses. Here, the rotation speed of the electric cylinder 5 is controlled by the control unit 66 so that the impact generated on the boom 4 is reduced and the smooth raising / lowering operation is performed when the raising / lowering operation of the boom 4 is started and stopped.

  And the pile of roses is broken by the rotating bucket wheel 7, and the roses are collected in the bucket. The roses collected in the bucket are sent to the boom conveyor 8 by the rotation of the bucket wheel 7. The loose article placed on the boom conveyor 8 is conveyed from the distal end portion to the proximal end portion of the boom 4 and sent to a ground conveyor (not shown) through a chute 31 formed on the swivel base 3.

  If an impact load due to excavation impact or mountain collapse falls on the bucket wheel 7 during the reclaimer 1 as described above, an overload for contracting the rod 52 acts on the electric cylinder 5 supporting the boom 4. There are things to do. When a torque greater than the set torque is applied to the friction clutch 64 provided on the transmission shafts 71 and 72 for transmitting power between the electric motor 61 and the reduction gear 62 due to overload, the friction clutch 64 slips and the reduction gear 62 is applied. Torque transmission rate from the motor to the electric motor 61 decreases. Thereby, it can avoid that excessive torque enters into the electric motor 61, and the electric motor 61 and the brake device 65 are damaged. Further, slipping of the friction clutch 64 allows the rod 52 to retreat, thereby releasing impact energy and preventing the electric cylinder 5, the boom 4 and the swivel base 3 from being damaged.

  As described above, by providing the mechanical friction clutch 64 in the power transmission path of the electric motor 61 from the speed reducer 62, a torque equal to or higher than the set torque is applied to the electric motor 61 regardless of whether the electric motor 61 is operating or stopped. Can be prevented and the electric cylinder 5 can be protected from overload.

  As described above, the reclaimer 1 according to this embodiment includes the traveling machine body 2, the swivel base 3 provided on the traveling machine body 2 so as to be horizontally turnable, and the base end portion connected to the swivel base 3 so as to be able to be lifted and lowered. The boom 4 and the electric cylinder 5 for raising and lowering the boom 4 are provided. The electric cylinder 5 includes a cylinder 51 having a base end connected to the swivel 3, a rod 52 inserted into the cylinder 51 and having a tip connected to the boom 4, and a drive for driving the rod 52 forward and backward with respect to the cylinder 51. A mechanism 53 is provided, and the boom 4 is lifted by the forward / backward movement of the rod 52. The drive mechanism 53 includes an electric motor 61, a speed reducer 62 that amplifies the output torque of the electric motor 61, a motion conversion device 63 that converts the rotational output of the speed reducer 62 into the forward / backward movement of the rod 52, and the electric motor 61 and the speed reducer. A mechanical friction clutch 64 that is provided in a power transmission path with the device 62 and slips when a torque greater than a predetermined set torque that is larger than the rated torque of the electric motor 61 and smaller than the maximum torque of the electric motor 61 is applied. And have.

  In the reclaimer 1 configured as described above, when a shock is applied to the boom 4 to lower the tip side, the friction clutch 64 slips if a large torque greater than the set torque is applied to the friction clutch 64 in order to contract the rod 52. To do. The slip of the friction clutch 64 allows the rod 52 to be shortened, and the rod 52 and the cylinder 51 are protected. Further, the slip of the friction clutch 64 reduces the torque transmission rate of the torque transmitted from the speed reducer 62 to the electric motor 61, thereby preventing an excessive load from being input to the electric motor 61. Is protected. When the torque applied to the friction clutch 64 becomes less than the set torque, that is, when the excessive load acting on the boom 4 is eliminated, the torque transmission rate of the friction clutch 64 is automatically restored and the electric cylinder 5 is reclaimed. 1 can be operated in the same manner as before the impact.

  Thus, in the reclaimer 1, when an impact is applied to the boom 4 to lower the tip, an overload applied to the electric cylinder 5 without control by the control means (control unit 66) is avoided, and The operation of the electric cylinder 5 automatically returns.

  The preferred embodiments of the present invention have been described above, but the present invention may include modifications in the specific structure and / or function details of the above embodiments without departing from the spirit of the present invention. . The configuration of the reclaimer 1 can be changed as follows, for example.

  For example, in the reclaimer 1 according to the above embodiment, the electric motor 61 of the electric cylinder 5 may be an electric motor with a power generation function. In this case, when the tip of the boom 4 rises, electricity is supplied to the electric motor 61 to output rotational power, and when the tip of the boom 4 falls, power is generated with the rotational power input to the electric motor 61. As described above, the operation of the electric motor 61 is controlled by the inverter included in the control unit 66. The electric energy obtained by the electric power generated by utilizing the position / kinetic energy of the boom 4 by the electric motor 61 is recovered or dissipated. The collected electrical energy may be stored in a storage battery or a capacitor and used for driving the electric motor 61 or the like.

  When an impact load is applied to the tip of the boom 4, the tip of the boom 4 is lowered, so that electric power is generated by the electric motor 61. Note that the lowering of the boom 4 when an impact load is applied is caused by a sensor that detects at least one of the load acting on the electric motor 61, the advancement length of the rod 52 from the cylinder 51, and the elevation angle of the boom 4. Detection can be performed based on the detection signal. When the control unit 66 that has received the detection signal from the sensor detects the lowering of the boom 4 that is not based on the operation (that is, the lowering of the boom 4 due to an impact load), power generation is performed with the rotational energy of the electric motor 61, that is, The electric flow of the electric motor 61 is switched so that the power generation brake acts on the electric motor 61. As described above, when the power generation brake is applied to the electric motor 61, the impact energy is released by the power generation using the rotation of the electric motor 61 in addition to the lowering of the boom 4 and the friction of the friction clutch 64. Recover from impact more quickly.

DESCRIPTION OF SYMBOLS 1: Reclaimer 2: Traveling machine body 3: Turntable 4: Boom 5: Electric cylinder 6: Cabin 7: Bucket wheel 8: Boom conveyor 9: Counterweight 31: Chute 32: Support shaft 42: Support shaft 51: Cylinder 52: Rod 53: Drive mechanism 61: Electric motor 62: Reduction device 63: Motion conversion device 64: Friction clutch 65: Brake device 66: Control units 71, 72: Transmission shaft 75: Electromagnetic clutch

Claims (2)

Traveling aircraft,
A swivel provided on the traveling machine body so as to be horizontally turnable;
A boom whose base end is connected to the swivel so as to be raised and lowered;
A cylinder having a base end connected to the swivel, a rod inserted into the cylinder and having a tip connected to the boom, and a drive mechanism for driving the rod forward and backward with respect to the cylinder; An electric cylinder for raising and lowering the boom by moving forward and backward.
The drive mechanism is
An electric motor;
A reduction gear that amplifies the output torque of the electric motor;
A motion converter that converts the rotational output of the speed reducer into the forward and backward movement of the rod;
A machine that is provided in a power transmission path between the electric motor and the speed reducer and slips when a torque greater than a predetermined set torque that is larger than the rated torque of the electric motor and smaller than the maximum torque of the electric motor is applied. A friction clutch of the type,
Reclaimer. When the tip of the boom rises, the electric motor is operated to output rotational power, and when the tip of the boom descends, the electric motor is operated so as to generate electric power with the rotational power input to the electric motor. A control unit for controlling,
The reclaimer according to claim 1.

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