JP2018043828A - crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that allows stable communication between a boom tip and a cab in conducting wire communication between the boom tip and the cab using a circuit for over-winding detection that is installed in the boom tip.SOLUTION: A crane includes an over-winding detection device for preventing over-winding of a wire cable at a boom tip and uses a circuit of the over-winding detection device to conduct wire communication between the boom tip and the cab, where a capacitor is installed to connect between both ends of wiring used in common with communication for the over-winding detection device.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a crane that performs wired communication between a boom tip and a cab.

  2. Description of the Related Art Conventionally, a crane having various detection devices such as a device for detecting overwinding of a wire rope, a device for detecting a load on a boom, and a device for detecting the length of a boom is known at the tip of the boom (for example, a patent) References 1 and 2). A signal from the boom tip detection device is transmitted to the controller of the safety device by wired communication using a cable, a cord or the like.

JP 2013-177230 A JP 2012-62176 A

  In a crane, an overwinding detection device for preventing overwinding of a wire rope is provided as an essential detector as a safety device. For this reason, when a new detection device is provided at the tip of the boom, utilizing an existing overwinding detection circuit has the advantage that no new wiring installation is required and the number of parts can be reduced.

  However, when communicating using the overwinding detection circuit wiring, wiring is complicated due to the connection to the jib circuit attached to the tip of the boom, sharing with other signal circuits for the purpose of saving wiring, etc. As a result, the communication performance deteriorates due to the high impedance state. Therefore, the present application provides a technology that enables stable communication between the boom tip and the cab when performing wired communication between the boom tip and the cab using an overwinding detection circuit. This is the issue.

  An overwinding detection device for preventing overwinding of a wire rope at a boom tip, and a crane that performs wired communication between a boom tip and a cab using a circuit of the overwinding detection device, Capacitors that connect both ends of the wiring shared by the winding detector communication were provided.

  According to the present invention, stable communication can be realized between the boom tip and the cab.

Crane side view Enlarged side view showing the boom tip of the crane Schematic diagram showing the communication path of the crane Schematic diagram showing the electrical path of the overwinding detection circuit

  With reference to FIG.1 and FIG.2, the structure of a crane is demonstrated. FIG. 1 is a side view showing the overall configuration of the crane 1. FIG. 2 is an enlarged view showing the tip of the boom 6 of the crane 1. In addition, in this embodiment, although the crane 1 is demonstrated as a mobile crane, this invention is applicable also to another crane.

  The crane 1 includes a vehicle body 2 for traveling and a crane device 3 that is transported by the vehicle body 2. The crane 1 can be moved to an unspecified place by the vehicle body 2 on which the crane device 3 is mounted. The vehicle body 2 includes outriggers 4 disposed at four corners. The crane 1 is a mobile crane that lifts a conveyed object by operating the crane device 3 in a state where the outrigger 4 is installed and the vehicle body 2 is fixed.

  The crane apparatus 3 includes a swivel base 5, a boom 6, a cab 7, a jib 8, a main hook block 9, a sub hook block 10, a hoisting cylinder 11, a main winch 12, a main wire rope 13, a sub winch 14, a sub wire rope 15, and the like. Is provided.

  The swivel base 5 constitutes the crane device 3 so as to be turnable, and is provided on the frame of the vehicle body 2 via an annular bearing. The boom 6 is composed of a plurality of boom members, and is configured to be extendable and retractable by moving each boom member. The boom 6 supports the wire ropes 13 and 15, and supports the wire ropes 13 and 15 in a state in which the conveyed product W can be lifted by expanding and contracting the boom 6. The cab 7 is provided on the side of the base end portion of the boom 6. Various operating tools such as a steering handle, a working lever, a button, and the like, and a display device that indicates the operating state of the crane 1 are provided in the room. Etc. are arranged. The jib 8 is connected to the boom head 16 at the tip of the boom 6 and expands the lift and work radius of the crane device 3.

  Guide sheaves 17, 18, a plurality of main sheaves 19, and sub sheaves 20 are provided on the boom head 16 at the tip of the boom 6. A main wire rope 13 is wound around the guide sheave 17 and the main sheave 19. A sub wire rope 15 is wound around the guide sheave 18 and the sub sheave 20.

  The main hook block 9 is provided with a plurality of hook sheaves 21 around which the main wire rope 13 is wound, and a main hook 22 for suspending a conveyed product. The sub-hook block 10 is provided with a sub-hook 23 to which a rope end of the sub-wire rope 15 is fixed and to suspend a conveyed product.

  The hoisting cylinder 11 is a hydraulic cylinder, and elongates and contracts to raise and lower the boom 6 and hold the posture of the boom 6. The main winch 12 is a hydraulic winch and winds up and down the main wire rope 13. Similarly, the sub winch 14 is a hydraulic winch and winds up and down the sub wire rope 15.

  The main wire rope 13 is wound around the plurality of main sheaves 19 and the plurality of hook sheaves 21 from the main winch 12 via the guide sheave 17. The sub wire rope 15 is wound around the guide sheave 18 from the sub winch 14 and fixed to the sub hook block 10.

  A main bracket 24 and a sub bracket 25 are rotatably attached to the tip of the boom head 16 with respect to the boom head 16. An overwinding prevention switch 26 is hung below the main bracket 24. The overwinding prevention switch 26 is turned “on” when the main hook block 9 comes into contact, and transmits a signal to stop the main winch 12. Similarly, an overwinding prevention switch 27 is hung below the sub bracket 25. When the subhook block 10 comes into contact with the overwinding prevention switch 27, the overwinding prevention switch 27 is turned on, and a signal is sent to stop the sub winch 14. To do.

  Next, with reference to FIG.3 and FIG.4, the communication circuit at the time of utilizing the overwinding circuit of the cab and boom tip in a crane is demonstrated. FIG. 3 is a schematic diagram showing an overall communication path 30 of the crane 1. FIG. 4 is a schematic diagram showing an electric path of the overwinding detection circuit 42.

  The communication path 30 of the crane 1 includes an upper electric circuit 31, an upper communication apparatus 32, a lower electric circuit 33, a lower communication apparatus 34, and wirings 35 and 36.

  The upper electric circuit 31 is provided at the tip of the boom 6 and includes an overwinding detection device 40 and the like. The lower electric circuit 33 is provided at the base end of the boom 6 and includes the controller 50 and the like. The wirings 35 and 36 connect the upper electric circuit 31 and the lower electric circuit 33 via the communication devices 32 and 34. The communication devices 32 and 34 transmit and receive signals as high-frequency current signals passing through the communication path 30 that is a closed circuit. Examples of objects to be communicated by the communication devices 32 and 34 include image data and moving image data captured from the tip of the boom, GNSS data at the tip of the boom, acceleration at the tip of the boom, and the like.

  The overwinding detection device 40 supplies the overwinding detection circuit 42 including the overwinding prevention switch 26 (27) and the cable 41 connected to the overwinding prevention switch 26 (27), and the overwinding detection circuit 42. AC power source (not shown). The overwinding detection circuit 42 is connected to the wirings 35 and 36 in the communication path 30. Since these cables 41 extend from the tip of the telescopic boom 6 to the overwinding prevention switch 26 (27), they are routed in a complicated manner in the upper electric circuit 31. That is, in the upper electric circuit 31, the cable 41 is in a high impedance state.

  The controller 50 controls the operation of the crane 1. The controller 50 is connected to the overwinding detection device 40 via the communication path 30, receives the detection signal from the overwinding prevention switch 26 (27), and detects the overwinding state of the wire rope 13 (15). Then, the winding of the winch 12 (14) is stopped. Further, the controller 50 is electrically connected to display devices and operation tools provided in the cab 7 and various hydraulic actuators of the crane 1, and can appropriately transmit and receive electrical signals thereto. That is, in the communication path 30, wired communication between the tip of the boom 6 and the cab 7 is possible via the controller 50.

  As shown in FIG. 4, a capacitor 43 is provided so as to connect the wiring 35 and the wiring 36 of the overwinding detection circuit 42 in the overwinding detection device 40. In this way, the capacitor 43 is inserted so as to connect the inlets and outlets of the wires 35 and 36 connected to the overwinding detection circuit 42, and both ends of the wire shared for communication in the overwinding detection device 40 are connected via the capacitor 43. Connected. As a result, a current signal, which is a high-frequency signal passing through the communication path 30, passes through the capacitor 43 when passing through the overwinding detection circuit 42. That is, even when a new communication device (communication device 32/34) is provided in the communication path 30 by utilizing the overwinding detection circuit 42, the capacitor 43 causes the high frequency component in the transmission / reception signal of the communication device to have a high impedance. By bypassing the cable 41, a low impedance state is maintained, and deterioration of communication performance can be prevented.

  Further, since a current signal as a high frequency component passes through the capacitor 43, it is possible to communicate even when the overwinding prevention switch 26 (27) is in an “off” state. In addition, by providing the capacitors 43 at the inlet and outlet in the upper circuit 31, even if the circuit inside the capacitor 43 is complicated, the communication performance is not affected. It is possible to adopt the sharing of information without problems.

  Similarly, in the lower electric circuit 33, when an existing circuit is used, it is possible to insert a capacitor so as to connect both ends of the wiring shared for communication, and the same effect can be obtained.

  1: Crane, 6: Boom, 7: Cab, 13: Main wire rope, 15: Sub wire rope, 30: Communication path, 31: Upper circuit, 35/36: Wiring, 40: Overwind detection device, 41: Cable 42: Overwinding detection circuit, 43: Capacitor, 50: Controller

Claims (1)

A crane comprising an overwinding detection device for preventing overwinding of a wire rope at a boom tip, and performing wired communication between the boom tip and a cab using a circuit of the overwinding detection device,
The crane provided with the capacitor | condenser which connects the both ends of the wiring shared by communication of the said overwinding detection apparatus.

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