JP2873498B2 - Boom-type work vehicle safety device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a boom type working vehicle such as a truck crane, and more specifically, a limit stress value in which an actual stress value generated during a boom-related operation is set in advance. And a safety device for a boom-type work vehicle, which automatically restricts a boom-related operation when the vehicle reaches the maximum.

(Prior art) Conventionally, in a mobile crane such as a truck crane, which is a typical example of a boom-type work vehicle, in general, the actual moment generated in the boom during a boom-related operation is determined by a danger value of the crane falling or a load supporting capacity. A safety device (overload prevention device) for limiting (disabling) the boom-related work when the moment is equal to or larger than the limit moment which is a limit is provided. The above-mentioned boom-related work includes a boom-based hanging load operation, a boom operation posture changing operation without a hanging load operation, and a boom position changing operation by turning a swivel base.

By the way, in the conventional overload prevention device for a mobile crane, the actual moment during a boom-related operation is calculated as follows. That is, in this type of mobile crane, as shown in FIG. 4, the base end of a boom (telescopic boom) 3 is pivotally connected to the swivel base 2 with a pin (boom up / down fulcrum) 51 and the base of the up / down cylinder 4 is provided. The end is connected to the swivel 2 by a pin (cylinder base fulcrum) 52, and the tip of the undulating cylinder 4 is connected to the boom 3 by a pin (cylinder tip fulcrum) 53. As shown in FIG. 5, the actual moment calculating means 8A for calculating the actual moment includes:
The distance L between the boom raising and lowering fulcrum 51 and the cylinder base fulcrum 52, the distance M between the boom raising and lowering fulcrum 51 and the cylinder tip fulcrum 53, and the boom raising and lowering fulcrum 51 and the cylinder base relative to a straight line P orthogonal to the turning center line O of the swivel base. Each data on the intersection angle θ with the straight line Q connecting the end fulcrum 52 is stored in advance as three fulcrum-related constants. And the actual moment calculating means 8A is
From the three fulcrum-related constants and the signal from the boom undulation angle detecting means 32 (FIG. 4) for detecting the undulation angle of the boom 3 with respect to the ground, the length of the perpendicular from the boom undulation fulcrum 51 to the axis R of the undulating cylinder 4 The height H is calculated by calculation.
The calculated length H is a moment arm around the boom hoisting fulcrum 51 of the hoisting cylinder output. The actual moment around the boom raising and lowering fulcrum at the time of the boom-related work is the data from the moment arm H calculated by the actual moment calculating means 8A and the data from the hoisting cylinder output detecting means 41 for detecting the force acting on the hoisting cylinder 4. Is multiplied.

On the other hand, the limit moment calculating means 7 includes a limit value of a boom moment for each of the outrigger extended state, the swivel swivel position, and the operating posture of the boom 3 (including the boom-to-ground elevation angle and the boom length in the case of the telescopic boom). Limit moment). This limit moment calculating means 7
In the process of calculating the limit moment, the outrigger overhang state detecting means 61, the swivel turning position detecting means 20, and the boom operating posture detecting means 31 (consisting of the boom hoisting angle detecting means 32 and the boom length detecting means 33) are used. A limit value of the boom moment corresponding to the actual operating posture of the crane is obtained from a group of the limit values of the boom moment storing the data as the index signal.
Conventionally, in calculating the limit value of the boom moment, a limit load value corresponding to the actual operating posture of the crane is obtained from a limit load value group stored in the limit moment calculation means 7. In some cases, a limit moment is calculated based on the limit load value.

The overload prevention device compares the actual moment calculated by the actual moment calculation means 8A with the limit moment calculated by the limit moment calculation means 7 at the time of the boom-related work by the comparison means 9 and compares the actual moment with the former (actual). When the value of the moment reaches the value of the latter (limit moment), various driving devices (for example, a lifting winch, a boom telescopic cylinder, a boom up-and-down cylinder, and a swivel table swing) for a boom-related operation are received by a signal from the boom-related operation control means 10. The operation of the driving device and the like is stopped.

By the way, in this type of mobile crane, the boom-related work is performed while the swivel base 2 is held in a horizontal posture. During the boom-related work, the entire vehicle 1 is tilted due to the suspended load or the boom operating posture. The swivel 2 may be tilted from the horizontal position due to looseness or rattling of the swivel bearing. When the swivel 2 is tilted in this manner, for example, as shown in FIG. 5, the cylinder base end fulcrum 52 is displaced to the position indicated by reference numeral 52 ', and the length of the moment arm around the boom raising / lowering fulcrum of the up / down cylinder output is indicated by the numeral. From H, it changes (becomes longer) as shown by the symbol H '.

(Problems to be Solved by the Invention) However, in the above-described safety device (overload prevention device) in the conventional mobile crane, it is necessary to calculate the moment arm around the boom up / down fulcrum of the up / down cylinder output during the boom-related work. In this case, the calculation is performed assuming that the swivel 2 is always in a horizontal posture. Therefore, when the boom-related work is performed in a state where the swivel 2 is inclined from the horizontal, the calculated moment arm length H and the actual moment There is a problem that the arm lengths H 'are different (H <H'), and the accuracy is low (the reliability of the safety device is reduced).

As a conventional safety device of this type, there is a safety device that compares an actual undulating cylinder output during a boom-related operation with a limit undulating cylinder output calculated by an arithmetic unit to control a crane. Thus, even when the crane control is performed by comparing the actual undulating cylinder output with the limit undulating cylinder output, no information regarding the tilt of the swivel base is taken into account.

In view of the above-mentioned problems of the conventional safety device, even if a boom-related operation is performed in a state where the swivel is inclined, the invention of the present application determines the actual moment or the actual cylinder output that is generated at that time. It is an object of the present invention to provide a safety device for a boom-type work vehicle that can be accurately calculated.

(Means for Solving the Problems) The invention according to claim 1 of the present application is directed to a vehicle, a swivel mounted on the vehicle so as to be able to turn horizontally, a boom mounted on the swivel so as to be able to move up and down, and the boom as a swivel. In a safety device for a boom-type work vehicle having an up-and-down cylinder for raising and lowering
A limit moment calculating means for calculating a boom limit moment for each boom-related work state; and an actual moment calculating means for calculating an actual moment generated on the boom during the boom-related work, wherein the actual moment calculating means calculates Boom-related operation control means for comparing the actual moment with the limit moment calculated by the limit moment calculation means and issuing a signal for restricting the boom-related operation when the actual moment reaches the limit moment; Is an up-and-down cylinder taking into account data from the boom operating attitude detecting means for detecting the operating attitude of the boom and data from the swivel tilt angle data transmitting means for transmitting data relating to the tilt angle to the ground of the swivel. Calculate the length of the moment arm around the output boom fulcrum. Is characterized in that it is composed as to calculate the actual moment when the boom-related work data by multiplying the from derricking cylinder output detecting means for detecting a force acting on the length and the relief cylinder of the moment arm.

Further, the invention of claim 2 of the present application is directed to a vehicle, a swivel mounted on the vehicle so as to be able to turn horizontally, a boom mounted on the swivel so as to be able to raise and lower, and an up-and-down cylinder for raising and lowering the boom with respect to the turntable. Moment calculating means for calculating the limit moment of the hoisting cylinder for each boom-related work state, and the actual calculation of the actual hoisting cylinder output generated in the hoisting cylinder during the boom-related work An up-and-down cylinder output calculation means, and comparing the actual up-down cylinder output calculated by the actual up-down cylinder output calculation means with the limit up-down cylinder output calculated by the limit up-down cylinder output calculation means, Boom-related operation control means for issuing a signal for limiting the boom-related operation when the limit undulating cylinder output is reached, The actual up-and-down cylinder output calculating means includes data from the up-and-down cylinder output detecting means for detecting the output of the up-and-down cylinder and data from the swivel inclination data transmitting means for transmitting data relating to the inclination angle of the swivel to the ground. Taking into account the length of the moment arm around the boom hoisting fulcrum of the hoisting cylinder output, and calculating the actual hoisting cylinder output during the boom-related work based on the length of the moment arm. Features.

(Operation) The safety device according to the first aspect of the present invention controls a boom-related operation by comparing an actual moment and a limit moment during a boom-related operation.
The actual moment calculating means calculates the moment arm around the boom hoisting fulcrum of the hoisting cylinder output in consideration of data from the turning base tilt angle data transmitting means relating to the tilt angle of the turning base to the ground. Even when the swivel base is tilted to the ground at the time of the related work, it is possible to accurately calculate the length of the moment arm in the swivel base tilt state, and thereby the swivel base tilt state Can be accurately calculated.

Further, in the safety device according to the second aspect of the present invention, the boom-related operation is controlled by comparing the actual hoisting cylinder output and the limit hoisting cylinder output during the boom-related work. The output calculation means is
The actual undulating cylinder output is calculated by taking into account the data related to the tilt angle of the swivel with respect to the ground, so that the actual undulating cylinder output at that time can be accurately calculated even when the swivel is tilted. Become like

(Effects of the Invention) Therefore, according to the safety device of the first aspect of the present invention, even when the boom-related work is performed while the turntable is inclined, the actual moment in the actual posture state of the turntable is obtained. It can be calculated accurately, and by comparing the exact actual moment with the limit moment, it is possible to perform more detailed control of the boom-related operation and to improve the reliability of the safety device. .

According to the safety device of the second aspect of the present invention, it is possible to accurately calculate the actual undulating cylinder output in the actual posture state of the swivel, and to compare the accurate actual undulating cylinder output with the limit undulating cylinder output. According to claim 1,
The same effect can be obtained.

(Embodiment) An embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 shows a boom type working vehicle according to an embodiment (first embodiment) of the present invention. FIG. 2 shows a modification (second embodiment) of the embodiment shown in FIG. 1, and FIG. 3 shows an embodiment (second embodiment) according to the present invention. 3) is shown. In these embodiments, a mobile crane is used as a boom type working vehicle.

The mobile crane of each embodiment shown in FIG. 1 to FIG. 3 mounts a swivel 2 on a vehicle 1 so as to be able to turn horizontally, and mounts a boom 3 on the swivel 2 so as to be able to move up and down. It is configured so that it can be raised and lowered by the lifting cylinder 4.

The vehicle 1 is provided with an outrigger 6, and the outrigger 6 is used by being grounded as necessary during a boom-related operation. The boom-related work may be performed in a state where the outrigger 6 is not used, that is, in an on-tire state.

The turntable 2 is horizontally turned on the vehicle 1 by a turn drive device (not shown). A winch 5 for hanging loads is provided on the swivel 2.

In this embodiment, the boom 3 includes a plurality of single booms (3 booms).
Book) A continuous telescopic boom is adopted.

The base end of the boom 3 is pivotally mounted on the swivel base 2 by a pin (boom fulcrum) 51, and the base end of the up / down cylinder 4 is separated from the boom fulcrum 51 by a pin (cylinder base fulcrum) 52. 2, the tip of the undulating cylinder 4 is pivotally attached to the boom 3 by a pin (cylinder tip fulcrum) 53.

When the actual stress applied to the boom 3 or the up-and-down cylinder 4 at the time of the boom-related work reaches a pre-stored limit stress value, the mobile crane of each embodiment shown in FIGS. Is provided with a safety device (overload prevention device) for controlling to stop the boom-related work.

In the safety device of the first embodiment shown in FIG. 1, the outrigger overhang state detecting means 61, the swivel swivel position detecting means
20, boom operating posture detecting means 31 (boom hoisting angle detecting means
32) and a limit value (limit moment) of the boom moment for each operating posture based on various data from the boom length detecting means 33).
On the other hand, from the boom undulation angle detecting means 32, the swivel tilt angle data transmitting means 22 (corresponding to the swivel tilt angle detecting means in the first embodiment), Based on the data, the actual moment calculating means 8 calculates the boom moment actually generated for each operating posture, and in a boom-related work state, the actual moment calculated by the actual moment calculating means 8 and the limit moment The limit moment stored in the arithmetic means 7 is compared with the limit moment by the comparing means 9, and when the actual moment reaches the limit moment, a signal for restricting the boom-related work is transmitted from the boom-related operation control means 10 to various types of the crane driving device. It is configured to be emitted toward the control valve.

In the first embodiment, the swivel tilt angle detecting means 22,
As the boom undulation angle detection means 32, the boom length detection means 33, and the undulation cylinder output detection means 41, conventionally used angle detectors, length detectors, and output detectors, respectively, are employed. For example, a swivel tilt angle detecting means
A weight type angle detector is adopted as each of the 22 and the boom hoisting angle detecting means 32. Further, as the boom length detecting means 33, a wire pull-out type length detector is employed. Further, as the undulating cylinder output detecting means 41, a strain gauge type output detector is employed.

The limit moment calculating means 7 is provided with the outrigger overhang state detecting means 61, the swivel turning position detecting means 20, the boom undulation angle detecting means 32, and the boom length detecting means 33, similarly to the conventional example shown in FIG. And the limit value of the boom moment corresponding to the actual operating posture of the crane is calculated from the limit value group stored in the limit moment calculating means 7. In calculating the limit value of the boom moment, a limit load value corresponding to the actual operating posture of the crane is obtained from the limit load value group stored in the limit moment calculation means 7, and the limit load value is calculated. The limit moment may be calculated based on.

The actual moment calculating means 8 calculates the actual moment in consideration of the information from the swivel tilt angle detecting means 22 in addition to the conventional example shown in FIG. That is, during a boom-related operation, the vehicle 1 itself may incline or the swivel base 2 may incline with respect to the vehicle frame, and the swivel base 2 may incline with respect to the horizontal plane. When the swivel base 2 is tilted in this manner, as described in the section of the related art (see FIG. 5), the length of the moment arm around the boom fulcrum fulcrum 51 is, for example, H (when the swivel base is in a horizontal state). Symbol H '(when the swivel is inclined)
Changes to However, in the safety device of this embodiment, the inclination angle of the swivel 2 with respect to the ground is detected by the swivel inclination angle detecting means 22 and the data is input to the actual moment calculating means 8. The length of the moment arm around the boom fulcrum fulcrum is determined based on the data from the swivel tilt angle detection means 22 and the data from the boom undulation angle detection means 32. Is multiplied by the data from the up-and-down cylinder output detecting means 41 to detect the actual moment at the time of the boom-related work. As described above, the value of the actual moment calculated in consideration of the data regarding the inclination angle of the swivel 2 with respect to the ground accurately reflects the actual moment at the present time at the time of the boom-related work. Therefore, during the boom-related work, the crane control can be more finely controlled by comparing the accurately calculated actual moment with the limit moment in the current posture of the crane (the reliability of the safety device). Is higher).

The inclination angle of the swivel 2 to the ground at the time of the boom-related work varies depending on the softness of the ground at the vehicle installation location, whether the outrigger 6 is used or not used, the weight of the lifting load, and the like. The turntable-to-ground tilt angle that has changed according to the conditions is accurately detected by the turntable tilt angle detection means 22, and the actual moment is calculated by the actual moment calculation means 8 based on the data from the turntable tilt angle detection means 22. Therefore, an accurate actual moment can always be calculated irrespective of the magnitude of the tilt amount of the swivel 2.

The safety device according to the second embodiment shown in FIG. 2 is different from the swivel tilt angle detecting means 22 of the first embodiment as a swivel tilt angle data transmitting means in that the boom hoisting angle detecting means 32 and the hoisting cylinder output detecting means are used. Based on each data from the outrigger extension state detecting means 41 and the outrigger extended state detecting means 61, a swivel tilt angle calculating means 23 is used which is read from a memory functionally stored. In other words, in the swivel tilt angle calculating means 23, how much the swivel 2 is tilted in advance is functionally determined in accordance with the operating posture (up and down angle) of the boom 3, the output of the up and down cylinder 4 and the outrigger state of the outrigger 6. At the time of the boom-related work, it is selected from the memories stored in the swivel tilt angle calculating means 23 based on the respective data from the respective detecting means 32, 41, and 61. Is output to the actual moment calculating means 8 side. Also in the case of the second embodiment, it is possible to calculate the actual moment in consideration of the inclination angle of the swivel 2 with respect to the ground.

In the second embodiment, the swivel tilt angle detecting means 22 in FIG. 1 is not required, and the other components in the second embodiment are the same as those in the first embodiment.

In the safety device according to the third embodiment shown in FIG. 3, the actual hoisting cylinder output actually acting on the hoisting cylinder 4 during the boom-related work and the crane operating posture are stored in advance in the limit moment calculating means 7 in memory. The crane control is performed by comparing the output with the limit undulating cylinder calculated based on the limit moment. In the third embodiment, the actual undulating cylinder output is the undulating cylinder output data detected by the undulating cylinder output detecting means 41 during the boom-related work, and the data on the swivel tilt attitude from the swivel tilt angle detecting means 22. , The data relating to the boom hoist angle from the boom hoist angle detecting means 32 are input to the actual hoist cylinder output calculating means 12, and are calculated there. That is, when the swivel 2 tilts, for example, the length of the moment arm changes from H to H ′ in FIG. 5, but the moment obtained by changing the limit moment value calculated by the limit moment calculating means 7 is changed. By dividing by the arm length H ', the actual undulating cylinder output during boom-related work is calculated. In the case of the third embodiment, the weight type angle detector 22 for mechanically detecting the tilt of the swivel 2 is employed as the swivel tilt angle data transmitting means. Alternatively, the swivel tilt angle calculating means 23 employed in the second embodiment (FIG. 2) may be employed. In the third embodiment (FIG. 3), the limit undulation cylinder output is calculated by inputting the limit moment value calculated by the limit moment calculation means 7 to the limit undulation cylinder output calculation means 11 and calculating there. It is supposed to be. In the case of the third embodiment, the actual undulating cylinder output calculated in consideration of the inclination angle of the swivel 2 with respect to the ground is compared with the limit undulating cylinder output calculated based on the limit moment value. Since the control is performed, a detailed and highly safe boom-related operation can be performed similarly to the safety devices of the first and second embodiments.

[Brief description of the drawings]

FIG. 1 is a side view of a boom type work vehicle provided with a safety device according to the first embodiment of the present invention, and FIG. 2 is a safety device of another embodiment according to the first embodiment of the present invention. FIG. 3 is a side view of a boom type working vehicle provided with a safety device according to the second embodiment of the present invention, and FIG. 3 is a side view of a boom type working vehicle provided with the conventional safety device. FIG. 5 is a side view of the mobile crane, and FIG. 5 is an explanatory view of the operation of the safety device of FIG. DESCRIPTION OF SYMBOLS 1 ... Vehicle 2 ... Turning table 3 ... Boom 4 ... Undulating cylinder 6 ... Outrigger 7 ... Limit moment calculating means 8 ... Actual moment calculating means 9 ... Comparison means 10 ... Boom related operation control means 11 ...... Limiting up / down cylinder output calculation means 12 ... Actual up / down cylinder output calculation means 22 ... Turn table inclination angle detection means 23 ... Turn table inclination angle calculation means 31 ... Boom operating attitude detection means 32 ... Boom undulation angle detection Means 33 Boom length detection means 41 Undulating cylinder output detection means

Claims (2)

(57) [Claims] 1. A vehicle (1), a swivel (2) mounted on the vehicle (1) so as to be able to turn horizontally, a boom (3) mounted on the swivel (2) so as to be able to move up and down, and the boom A limit moment calculating means (7) for calculating a limit moment of the boom for each boom-related operation state in a boom type work vehicle provided with an up / down cylinder (4) for raising / lowering the (3) with respect to the swivel (2); Actual moment calculating means (8) for calculating an actual moment generated in the boom during a boom-related operation, wherein the actual moment calculated by the actual moment calculating means (8) and the limit moment calculating means (7) are calculated. A safety device comprising boom-related operation control means (10) for comparing the actual moment to the limit moment and outputting a signal for restricting the boom-related operation when the actual moment reaches the limit moment. The actual moment calculating means (8) calculates the data from the boom operating attitude detecting means (31) for detecting the operating attitude of the boom (3) and the data relating to the inclination angle of the swivel (2) to the ground. The length of the moment arm around the boom up / down fulcrum of the up / down cylinder output is calculated in consideration of the data from the turning table inclination angle data transmission means (22, 23) to be transmitted, and the length of the moment arm and the up / down cylinder ( 4) The safety of a boom-type work vehicle is characterized in that an actual moment during a boom-related work is calculated by multiplying data from an undulating cylinder output detection means (41) for detecting a force acting on the boom type work vehicle. apparatus. 2. A vehicle (1), a swivel (2) mounted on the vehicle (1) so as to be able to turn horizontally, a boom (3) mounted on the swivel (2) so as to be able to move up and down, and the boom. In a boom-type work vehicle provided with an up-and-down cylinder (4) for raising and lowering (3) with respect to a swivel (2), a limit up-down cylinder for calculating a limit up-down cylinder output of the up-down cylinder (4) for each boom-related operation state. Output operation means (11); and actual operation cylinder output operation means (12) for calculating the actual operation cylinder output generated in the operation cylinder (4) during the boom-related work. The actual undulating cylinder output calculated in 12) is compared with the limit undulating cylinder output calculated by the limit undulating cylinder output calculating means (11). A safety device comprising a boom-related operation control means (10) for issuing a signal for restricting a system-related operation, wherein the actual hoist cylinder output calculating means (12) detects an output of the hoist cylinder (4). The output of the undulating cylinder output taking into account the data from the output detecting means (41) and the data from the swivel tilt angle data transmitting means (22, 23) for transmitting data relating to the tilt angle of the swivel (2) to the ground. A boom-type work vehicle, wherein the length of the moment arm around the boom-up / down support point is calculated, and the actual up-and-down cylinder output during boom-related work is calculated based on the length of the moment arm. Safety equipment.