JPS5846439B2 - 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 adapt to the optimum 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. To this end, 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 condition and the use/non-use response signal of the additional boom, and confirm that the actual measured location is the limit. 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 the safety of crane operations.

Among the limit value correction signals of the boom moment limiting device mentioned above, the boom moment limiter is used to generate a signal that responds to the condition of the crane when the boom is not in use. This device is for selecting whether to use a boom moment limiter, or an operating condition that generates a signal in response to the crane condition when using a supplementary boom. Conventional boom moment limiters are operated by a manual switch operated by the operator I made the above selection.

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 exists a drawback as a safety device.

In addition, as an alternative to this manual type, a switch is provided that is linked to the connection and disconnection of the clutch of the auxiliary winch, and when the clutch is disconnected via this switch, a boom moment limiter is activated to replenish the clutch and maintain crane working conditions when the boom is not in use. The boom moment limiting device is automatically activated by generating a signal in response to a crane working condition when the boom is in use, and generating a signal in response to a crane working condition when the boom is in use. It is conceivable that the system could be used as a safety device, but this device had the following drawbacks.

Generally, the clutches of the main winch and the sub winch are connected when driving the main winch and the sub winch, respectively, and are normally disengaged when the main winch and the sub winch are not being driven.

Therefore, the auxiliary winch is not used when adding the supplementary boom to the tip of the foundation boom, or when moving the supplementary boom together with the foundation boom to the desired position by rotating etc. after installing the supplementary boom. The secondary winch clutch is disengaged and the boom moment limiter is applied to generate a signal responsive to the crane operating conditions when the boom is not in use.

This signal is based on the assumption that the supplementary boom has been removed from the tip of the foundation boom and that the weight component of the supplementary boom is not acting in front of the tip of the foundation boom. When a boom is attached to the tip of the boom and the boom is rotated, depending on its position, there is a risk that the crane may fall over, which could be a serious accident.

The present invention seeks to provide a novel boom moment limiting device that addresses the above-mentioned problems.

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 main winch is removed from the tip of the foundation boom and hoisted using the main hook, a signal is generated in response to the crane operating state.The switching operation between the operating state and the operating state is performed in conjunction with the engagement and disengagement of the main winch clutch. 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 lifting height and turning radius are insufficient for the load lifting operation using the main hook 7 suspended 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, it is removed from 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 correction of the limit value of the boom [-ment limiter 18 according to the hoisting angle of the foundation boom 5 is performed in conjunction with the hoisting operation of the foundation boom 5, and the correction of the limit value due to the use or disuse state of the supplementary boom 9 is performed mainly. This is performed in conjunction with the operation of the clutch lever 16 of the clutch 14 of the winch 8.

In other words, the clutch lever such as the one in which the clutch 14 is in contact
Connect the C and A contacts at the operating position 16 (position I in Figure 2), thereby actuating the boom moment limiter 18, removing the boom 9 from the tip of the base boom 5, and lifting the load using the main hook 7. When the clutch lever 16 is operated at the position (■ position in Fig. 2), the C contact and the B contact are connected, thereby generating a signal in response to the crane working condition when performing the boom operation. The moment limiting device 18 is used to add the additional boom 9 to the tip of the basic boom 5, and the clutch lever 16 and the boom moment are limited by generating a signal responsive to the working condition when lifting a load using the secondary hook 11. It is operated by a switch 19 associated with the device 18.

The truck crane 1 always connects the clutch 14 of the main winch 8 when removing the supplementary boom 9 from the tip of the foundation boom 5 and lifting a load using the main hook 7. Since the clutch 14 of the main winch 8 is always disconnected when performing load lifting work using the sub hook 11 attached to the tip of the boom 5, the changeover switch 19 is operated in conjunction with the liquid state operation of the clutch 14. The boom moment limiting device 18 thus constructed is always maintained in a correct operating state because the limit value is automatically and correctly corrected depending on whether the additional boom is in use or not in use.

The boom moment limiting device configured as described above switches from the conventional manual type to the automatic type for switching depending on the use and non-use status of the supplementary boom, so it completely eliminates serious accidents that occur due to operator error. Since the clutch and switch of the main winch are linked together, the structure is simpler and cheaper, and it is less likely to break down compared to a structure in which each clutch of the main winch and the switch are linked. It is characterized by having few causes.

Furthermore, in the present invention, the main winch is not in use when the refilling boom is added to the tip of the foundation boom, and when the refilling boom is rotated etc. to the desired position together with the foundation boom after the addition is completed, the main winch is not in use. The winch clutch is disengaged, causing the boom moment limiter to generate a signal responsive to crane operating conditions when using the refill boom.

This signal was determined on the condition that a supplementary boom is added to the tip of the foundation boom and that the dead weight component of the supplementary boom is acting in front of the tip of the foundation boom, so the boom moment limiter is sufficient as a safety device. It fulfills its function.

As described above, the effects of the present invention are significant.

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 to 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, 8: Main winch, 14: Clutch, 16: Clutch lever, 18: Boom moment limiter, 19:
switch.

Claims (1)

[Claims] 1 Foundation boom, supplementary boom that is used by adding it to the tip of the foundation boom if necessary, main winch that hoists up and lowers the main hook suspended from the tip of the foundation boom, and 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 that generates a signal in response to the working state of the crane when a supplementary boom is supplemented to the tip of a foundation boom and lifting work is performed using a supplementary hook; A switch that generates a signal in response to the crane working state when the boom is removed from the tip of the foundation boom and lifted by the main hook.The switch operates in conjunction with the main winch clutch disengagement and connection operations to switch between the operating state and the operating state. A boom moment control device configured to select the former operating state when the main winch clutch is in the disengaged state and select the latter operating state when the main winch clutch is in the engaged state.