JPS6340532Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is designed to prevent
This invention relates to a lowering control device for a grab dredger that can be easily controlled using a regular brake handle.

Conventional grab dredgers operate hoisting and lowering by opening and closing the grab using handles that control the operation of brakes and clutches inserted between the opening/closing drum and support drum and their respective shafts. . However, since each drum shaft is operated while being connected to the prime mover during unwinding, it is not possible to connect the support drum and the opening/closing drum with a clutch, and it is difficult to synchronize the support drum and the opening/closing drum. Moreover, since these operations had to be performed manually, the steering wheel operation was extremely difficult, placing a heavy burden on the operator. In addition, since it does not have a dedicated handle for lowering and lowering the grab, the support brake that is operated when lowering the grab and the opening/closing brake may not be well balanced and the opening/closing state may change, especially when opening/closing the grab underwater. It is not possible to check the status of the machine, resulting in extremely poor work efficiency, and the operation is not only physically but also mentally tiring. It is also possible to use compressed air to control the operations of brakes, clutches, etc. in order to reduce the need to operate the handle, but due to changes in pressure, the synchronization between the support drum and the opening/closing drum during unwinding may become worse. It had some drawbacks that made it difficult.

Therefore, in view of the above-mentioned circumstances, the present invention expands the grab in advance when lowering it, connects the support drum and the opening/closing drum, fixes the expanded state of the grab, and connects these drums. By disconnecting the prime mover with a support/opening/closing drum synchronizing clutch, the connected support drum and opening/closing drum are braked by one drake, that is, by one operating handle, and the naturally falling grab is lowered. An object of the present invention is to provide a lowering control device for a grab dredger that can control the grab dredger while it is in a fully expanded state.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the unwinding control device for a grab dredger according to the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is an opening/closing drum, 2 is a support drum, and 3 is a jib that performs a hoisting motion by rotation of a hoisting drum 5 around which a wire rope 4 is wound. Wire ropes 6 and 7 are wound around the opening/closing drum 1 and the support drum 2.
is connected to the grab 9 via a rope sheave 8 provided at the tip of the jib 3. The grab 9, the opening/closing drum 1, the support drum 2, and the undulating drum 5 are installed on a rotatable base.
The opening/closing drum 1, the support drum 2, and the undulating drum 5
A turning mechanism 10 for turning the base is rotationally driven by an engine 12 via a reduction gear 11, as shown in FIG. In this case, the shafts of the opening/closing drum 1 and the support drum 2 are connected by a power transmission mechanism such as a gear, and when one shaft is rotationally driven by the engine, the other shaft is also rotationally driven via the power transmission mechanism. It's becoming possible. Band brakes 13, 14, 15 and band clutches 16, 17, 18 are interposed between the opening/closing drum 1, the support drum 2, the undulating drum 5, and the respective shafts. The opening/closing drum 1, the support drum 2, the band brakes 13, 14, 15 and the band clutch 16 of the undulating drum 5,
17 and 18 can be operated by an opening/closing handle 19, a support handle 20, and a lifting handle 21, respectively. A band clutch type support/opening/closing drum synchronizing clutch 22 is inserted between the engine 12 and a shaft connecting the opening/closing drum 1 and the support drum 2. In addition, the support drum 2
A 20% internal expansion type brake 23 is interposed between the shaft and the shaft. This brake 23 is operated by a support lowering handle 26 via a pressure switch 24. The brake 23 may be provided on the opening/closing drum 1 side. Further, a limit switch 25 is attached to the support and unwinding handle 26. The pressure switch 24 is activated when the rotational force of the shaft of the support drum 2 or opening/closing drum 1 increases to a predetermined value or more when the grab 9 is lowered, and the band brake of the support drum 2 is activated by the energizing operation of the solenoid 27. 14 to perform braking. When the support unwinding handle 26 is operated to lower the grab 9, the limit switch 25 energizes the solenoid 28 to disengage the support/opening/closing drum synchronization clutch 22. I'm starting to let them do it. The band brakes 13, 14, 15, the brake 23, the band clutches 16, 17, 18, and the supporting/opening/closing drum synchronizing clutch 22 are operated by compressed air. That is, piping is connected from the compressor 30 via the air tank 31 to the opening/closing handle 19, the support handle 20, the up/down handle 21, and the support/lowering handle 26, and the opening/closing handle 19,
When the support handle 20, the lifting handle 21, and the support lowering handle 26 are operated, the band brakes 13, 14, 15, the brake 23 and band clutches 16, 17, 18, and the support/opening/closing drum synchronization clutch 22 are operated. The operation is controlled by intermittent supply of air or by changing the direction of supply. In particular, piping is provided from the support unwinding handle 26 so as to control the operations of the pressure operating means 32 and the band brake 23 via the pressure switch 24. Further, piping is provided so that the band brake 14 is operated from the air tank 31 via a solenoid 27 controlled by the pressure switch 24 and through the pressure operating means 33, and is also controlled by the limit switch 25 from the air tank 31. Operation of the band clutch 22 is controlled via a pressure operating means 34 via a solenoid 28. The opening/closing handle 19, the support handle 20, and the raising/lowering handle 21 control the air supply so that when tilted to one side, the clutch is operated, and when tilted to the other side, the brake is operated. When the handle 26 is tilted to one side, air is supplied to operate the brake 23, and when tilted to the other side, the brake 23 is released. It's summery. Therefore, when lowering the grab 9 to the seabed, first operate the support handle 20 and operate the band brake 14 with air to tighten the support drum 2, and at the same time, release the band clutch 17. On the other hand, operate the opening/closing handle 19 to loosen the band brake 13 with air, and also cut the band clutch 16 to fully open the opening/closing drum 1. After fully opening, operate the opening/closing handle 19 to release the opening/closing drum 13 with air. Release the band brake 13 and engage the band clutch 16. The support handle 20 is operated to release the band brake 14 and engage the band clutch 17. At the same time, the support lowering handle 26 is tilted to open the limit switch 25, which causes the solenoid 2
8 performs a biasing operation and the clutch 22 for synchronizing the support/opening/closing drum is disconnected by air, and the opening/closing drum 1 and the support drum 2 are disconnected from the engine 12. As a result, the grab 9 naturally falls under its own weight. In this case, since the respective shafts of the opening/closing drum 1 and the support drum 2 are connected by a power transmission mechanism, and each band clutch 16, 17 is in a tightened state, they mutually rotate simultaneously, and accordingly, the grab 9 Lower the machine while keeping it fully open. This unwinding speed is adjusted by operating the support unwinding handle 26 and applying braking with the brake 23 as appropriate. If this unwinding speed exceeds a predetermined value for some reason,
By pulling the support unloading handle in response to the rotational force of the shafts of the opening/closing drum 1 and support drum 2 corresponding to this value, the air pressure increases and the pressure switch 24 operates, and the solenoid 27 performs a biasing operation, and the band brake 14 applies braking to the support drum 2, thereby opening and closing the opening/closing drum 1.
It suddenly stops and acts as a safety mechanism.

In addition, in this embodiment, since a 20% internal expansion type brake is used as the brake 23 for supporting and lowering, the occurrence of so-called sagging of the grab 9 is reduced compared to the conventional external tightening band brake. The machine operates smoothly even when the machine is turned, and does not cause any problems such as runout during unwinding. Further, it goes without saying that the brake 23 may be provided on the opening/closing drum 1.

As described above, according to the unwinding control device for a grab dredger according to the present invention, since the support drum and opening/closing drum are separated from the prime mover when lowering the grab,
This support drum and opening/closing drum can be unloaded and rotated as one unit, and this unwinding can be controlled by operating only one brake, that is, one handle. It is extremely simple, improves work efficiency, and is extremely convenient in practice.

[Brief explanation of the drawing]

FIG. 1 is a side view of the grab dredger, and FIG. 2 is a configuration diagram of the unwinding control device for the grab dredger according to the present invention. 1...Opening/closing drum, 2...Support drum, 3...
Jib, 4, 6, 7... wire rope, 5... undulating drum, 8... rope sheave, 9... grab, 1
0... Turning mechanism, 11... Speed reducer, 12... Engine, 13, 14, 15... Band brake, 1
6, 17, 18...Band clutch, 19...Handle for opening/closing, 20...Handle for support, 21...
...Handle for raising and lowering, 22...Clutch for supporting/opening/closing drum synchronization, 22...Brake, 24...Pressure switch, 25...Limit switch,
26...Handle for supporting and lowering, 27, 28...
solenoid.

Claims (1)

[Scope of utility model registration request] A grab dredger comprising an opening/closing drum and a support drum whose shafts are connected to each other and rotationally driven by a prime mover, and a band brake and a band clutch which are respectively driven by the operation of the opening/closing handle and the support handle. A clutch for synchronizing the support/opening/closing drum is disposed between the shaft connecting the support drum and the prime mover, and the clutch is disposed only when the grab is lowered. A lowering control device for a grab dredger, characterized in that it is equipped with a band brake that is driven by the operation of a lowering handle.