JPS5846438B2 - Boom Moment Seigen Sochi - Google Patents

Description

Detailed Description of the Invention A crane having a base boom that can be hoisted and a main winch that hoists and lowers a main hook suspended from the tip of the base boom is capable of hoisting and lowering the base boom at a given time. It is widely used because it can quickly adjust to optimal crane conditions for crane work.

This type of crane is further equipped with an additional boom that is used by adding it to the tip of the foundation boom in order to expand its working radius and lifting height, and an auxiliary winch that hoists and lowers the auxiliary hook suspended from the tip of the additional boom. There is.

In such a lane, the maximum allowable lifting load varies depending on each crane condition, which is determined by the up-and-down condition of the foundation boom and the use or non-use of additional booms, so it is difficult to grasp the working condition. For this purpose, as a safety device, we compare the actual measured value corresponding to the lifting load with the limit value corrected by the luffing angle of the foundation boom that defines each crane state and the use/non-use response signal of the additional boom to determine the limit of the actual location. A boom moment limiter is installed that generates an alarm or a signal to stop the crane when a certain value is reached to ensure crane work safety.

Among the limit value correction signals of the boom moment limiting device mentioned above, the supplementary boom use/non-use state response signal is an operating state in which the boom moment limiting device generates a signal responsive to the crane condition when the supplementary boom is not in use. The boom moment limiter is designed to select whether the boom moment limiter is in an operating state that generates a signal in response to the condition of the crane when a supplementary boom is in use, and the conventional boom moment limiter is operated by a manual switch operated by the operator. I was making a choice.

In the conventional boom moment limiting device in which the replenishment boom use/disuse state response signal is selectively input using a manual switch, whether or not it operates correctly is determined by the operator using the manual switch. It is up to you to operate it correctly.

In other words, it is left to manual operation with the possibility of erroneous operation or forgetting, and there is a drawback as a safety device.

In addition, as an alternative to this manual method, the applicant previously proposed
There are two switches that connect and disconnect the clutches of the main winch and sub winch, and the boom moment limiter functions as a safety device only when one of the two switches is ON and the other is OFF. Although he invented something that would
(Patent No. 1049204, Special Publication No. 55-3275)
, this one had the following problems.

In other words, for crane work, an additional boom is added to the tip of the foundation boom, a side hook and a main hook are hung from the added addition boom and the tip of the foundation boom, respectively, and in order to use both hooks at the same time, the main winch is attached. There is a so-called co-hanging operation in which both the clutches of the auxiliary winch and the auxiliary winch are connected, but the problem with this co-hanging operation is that the boom moment limiter does not function as a safety device.

The present invention seeks to provide a new boom moment limiting device that eliminates the above-mentioned drawbacks of conventional boom moment limiting devices.

In other words, the foundation boom, a supplementary boom that is used by attaching it to the tip of the foundation boom if necessary, a main winch that hoists and lowers the main hook suspended from the tip of the foundation boom, and a main winch that hoists and lowers the secondary hook suspended from the tip of the supplementary boom. A boom moment limiting device for a crane having a secondary winch for lowering, which generates a signal in response to the crane working status when a supplementary boom is supplemented to the tip of a foundation boom and lifted by a secondary hook, and a supplementary boom. When the crane is removed from the tip of the foundation boom and hoisted using the main hook, a signal is generated in response to the crane working state.The switching operation between the operating state and the operating state is performed in conjunction with the clutch engagement and disengagement of the sub winch. The present invention relates to a boom moment limiting device for a crane constructed as described above.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a truck crane will be described below in detail with reference to the drawings.

The truck crane 1 includes a vehicle 2, a swivel base 3 mounted on the vehicle 2 so as to be freely swivelable, a base boom 5 whose base end is connected to the swivel base 3 in a manner that it can be raised or lowered, and whose elevation is adjusted by the expansion and contraction action of a hydraulic cylinder 4. A main winch 8 installed on the swivel platform 3 for hoisting and lowering the main hook 7 suspended from the tip of the foundation boom 5 via a wire rope 6, and a removable addition to the tip of the foundation boom 5. When the boom 9 and the supplementary boom 9 are attached to the tip of the foundation boom 5 (Fig. 1), a secondary hook 11 suspended from the tip of the supplementary boom 9 via a wire rope 10 is used for hoisting and lowering operations. It consists of an auxiliary winch 12 provided on a swivel base 3.

The main winch 8 and the sub winch 12 receive power from a single hydraulic motor 13 via clutches 14 and 15, respectively, as shown in FIG.

The clutches 14 and 15 are operated on and off by clutch levers 16 and 17, respectively, and the main winch 8 is operated by driving and controlling the hydraulic motor 13 with the clutch 14 engaged by the clutch lever 16. Operate hook 7 to raise and lower clutch lever 1.
By controlling the drive of the hydraulic motor 13 with the clutch 15 connected by 7, the sub winch 12 is operated to hoist and lower the sub hook 11.

゛The supplementary boom 9 is used to add to the tip of the foundation boom 5 and carry out the lifting operation using the sub hook 11 at the tip when the basic culm and turning radius are insufficient for the lifting operation using the main hook 7 suspended from the tip of the foundation boom 5. It is removed from the tip of the foundation boom 5 when lifting a load using the main hook 7 at the tip of the foundation boom 5.

18 is a boom moment limiting device, and the boom moment limiting device 18 receives a signal of a value responsive to the moment acting on the foundation boom 5 as an actual value;
The actual measured value is compared with a limit value that is corrected based on the luffing angle of the foundation boom 5 and the usage/disuse state of the supplementary boom 9, and when the actual measured value reaches the limit value, an alarm or a signal to stop the crane is issued. It consists of

The limit value of the boom moment limiter 18 is corrected by the raising and lowering angle of the foundation boom 5 in conjunction with the raising and lowering operation of the foundation boom 5, and the limit value is corrected by the width winch 12 depending on the use/disuse state of the supplementary boom 9. This is performed in conjunction with the operation of the clutch lever 17 of the clutch 15.

In other words, a clutch lever such as one in which the clutch 15 is in contact
Connect the C contact and the A contact at the operation position 17 (position 1 in Figure 2), and then connect the boom moment limiter 18 to add the boom 9 to the tip of the base boom 5 and use the secondary hook 11 to perform load lifting work. When the clutch lever 17 is operated at the operating position (■ position in Figure 2), which would disconnect the clutch 15, the C contact and the B contact are connected. Additional boom 9 with moment limiter 18
A switch 19 provided in connection with the clutch lever 17 and the boom moment limiter 18 generates a signal in response to the working condition when the main hook 7 is used to remove the main hook 7 from the tip of the foundation boom 5 and perform hoisting work using the main hook 7. They are linked.

The truck crane 1 always connects the clutch 15 of the auxiliary winch 12 when adding the replenishment boom 9 to the tip of the foundation boom 5 and performing lifting work using the sub hook 11. Since the clutch 15 of the auxiliary winch 12 must be disconnected when lifting a load with the main hook by removing it from the tip, the boom is designed so that its changeover switch 19 is operated in conjunction with the hydraulic operation of the clutch 15. The moment limiter 18 is always maintained in a correct operating state because the limit value is automatically and correctly corrected depending on the state in which the supplementary boom is in use or not in use.

In summary, since the present invention has the configuration as described in the claims, it is possible to completely prevent serious accidents that would occur due to operator error in the case of conventional manual type systems.

In addition, the boom moment limiting device of the present invention functions even during co-hanging work, and generates a signal in response to the crane work status when a supplementary boom is added to the tip of the foundation boom and hoisting work is performed using the secondary hook. This has the effect of achieving a safe operating state.

Furthermore, since the number of switches is smaller than that of the above-mentioned Japanese Patent Application No. 49-97455, the structure is simpler and there are fewer causes of failures.

It goes without saying that the foundation boom 5 in this embodiment may be a telescoping boom configured to be extendable and retractable.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a truck crane in which the present invention is to be implemented, and FIG. 2 is an explanatory diagram showing the relationship between the winch of the truck crane of FIG. 1 and the boom moment limiting device according to the present invention. 1 Nidrak crane, 5: Foundation boom, 9: Additional boom, 12: Sub winch, 15: Clutch, 17: Clutch lever, 18: Boom moment limiter, 19
:switch.

Claims (1)

[Claims] 1 Foundation boom, supplementary boom used by adding to the tip of the foundation boom as needed, main winch for hoisting up and lowering the main hook suspended from the tip of the foundation boom, and hoisting the secondary hook suspended from the tip of the supplementary boom. A boom moment limiting device for a crane having a sub winch for lowering, the operating state generating a signal in response to a crane working state when adding a supplementary boom to the tip of a foundation boom and performing lifting work with a sub hook; When the supplementary boom is removed from the tip of the foundation boom and lifted using the main hook, a signal is generated in response to the crane working state.The switching operation between the operating state and the operating state is linked to the clutch engagement and disengagement of the sub winch. A boom moment limiting device configured to select the former operating state through a switch when the clutch of the auxiliary winch is in the connected state, and select the latter operating state when the clutch of the auxiliary winch is in the disengaged state.