JP2564061B2 - Safety equipment for construction machinery - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, in a construction machine such as a crane having an upper revolving structure such as a swingable boom, sets a rated load according to the overhanging state of the outrigger jack, and based on this, The present invention relates to a safety device that performs forced turning stop control.

[0002]

2. Description of the Related Art In general, it is important to prevent buckling or overturning during the turning operation of the construction machine as described above. Therefore, when the working condition exceeds the safety range, it is forcibly forced. Various safety devices have been proposed that automatically stop the operation of a boom or the like.

In the conventional apparatus, the allowable condition is set equal over the entire 360 ° regardless of the turning angle. However, the outrigger jack provided on the crane is not always perfectly horizontally extended and has a small width. Roads, etc.
Since the horizontal extension amounts of some of the outrigger jacks may be different depending on the work place, in this case, it is necessary to change the allowable condition depending on the turning angle.

In view of this, in Japanese Patent Laid-Open No. 57-27893, the working state of the crane is detected moment by moment, and the rated load of the crane is calculated from the detected value and the set value of the hoisting capability stored corresponding to each state. It is shown that the safety operation is performed based on the comparison between the rated load and the actual load.

Further, in Japanese Patent Laid-Open No. 3-177299, the allowable swing range of the boom is stored in accordance with the horizontal extension amount of each outrigger jack, and the swing braking is performed before the actual working state exceeds this range. It is shown that the load is stopped in the safety area and the load is hardly shaken in this stopped state.

[0006]

Problems to be Solved by the Invention JP-A-57-2789
The device disclosed in Japanese Patent Publication No. 3 calculates the rated load momentarily based on the current outrigger jack bulge state, so it is possible to determine how much load can be suspended while the boom is stationary. However, it is not possible to perform a boom swing control, for example, a positive safety operation such as automatic braking to stop the boom within the safety area before the boom exceeds the safety area.

On the other hand, the apparatus disclosed in Japanese Patent Laid-Open No. 3-115091 calculates the allowable work radius from the lifting load of the upper swing body, sets the allowable work range based on this, and sets the allowable work radius. Since the boom swing is braked with a certain allowance angle so as not to exceed the limit, it is possible to reliably prevent the boom from exceeding the limit work area. However, in general, for construction machines such as cranes, for safety, it is strongly requested to perform safe operation (warning, forced stop, display of load factor, etc.) based on the load factor (ratio of lifting load to rated load). It is widely and generally practiced, and in order to calculate the above-mentioned limit work area in the above-mentioned device, in addition to the above calculation of the load factor, the calculation of the rated load according to the overhang amount of the outrigger jack and the working radius must be performed. Therefore, there is a problem that the arithmetic unit is complicated and the required capacity is increased accordingly.

Incidentally, Japanese Patent Laid-Open No. 3-73795 discloses that
A device that calculates the load factor over the entire circumference and displays it as a load factor image has been proposed. However, in this publication, what kind of specific load factor is to be calculated according to the working posture of the crane is proposed. Is not disclosed, and there is no description about the turning stop control of the boom. Therefore, it is not a concrete solution to the above problems.

In view of such circumstances, the present invention does not require a special calculation to obtain both the load factor and the drivable region, and reliably prevents the upper swing body from coming out of the safety region. It is an object of the present invention to provide a safety device for construction machines such as cranes that can perform

[0010]

SUMMARY OF THE INVENTION The present invention is a safety device for a construction machine, comprising a revolving upper revolving structure and a support member capable of overhanging, and suspending a load at a predetermined position of the upper revolving structure. Lifting load detecting means for detecting the lifting load of the revolving structure, working radius detecting means for detecting the working radius of the upper revolving structure, swing angle detecting means for detecting the revolving angle of the upper revolving structure, and each support. Supporting member detecting means for detecting the amount of overhang of the member, all-round rated load calculating means for calculating the rated load according to the working radius and the overhanging amount of each supporting member for each turning angle, and all-round rated load calculating means Calculated by the load factor calculating means for calculating the load factor based on the rated load calculated in step 1, the first actuating means for performing a safe operation based on the calculated load factor, and the full circumference rated load calculating device. Rated Heavy braking the remaining angle calculating means for calculating the remaining angle at which the current lifting load can be pivoted to a point that matches the upper rotating body without leaving the deflection of the suspended load,
A braking angular acceleration calculating means for calculating a braking angular acceleration for stopping, a required angle calculating means for calculating a turning angle of the upper swing body required for braking and stopping at the braking angular acceleration, and the calculated required Comparing means for comparing the angle and the remaining angle, and second actuating means for starting turning braking with the braking angular acceleration while the remaining angle does not exceed the required angle.

Here, the "safe operation based on the load factor" means not only a warning action and a forced stop action according to a specific value of the load factor, but also an action of directly displaying the load factor to the outside. Good.

[0012]

According to the above construction, the angle (required angle) required for braking the upper revolving superstructure with a predetermined braking angular acceleration and stopping it in the safety region is calculated, and at the time when this required angle can be secured. Turn braking is applied with. As a result, the upper swing body reliably stops within the safety area, and at the time of this stop, the load swing hardly remains.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. Although a crane is disclosed here as an example of a construction machine, the present invention can be applied to various construction machines including an upper swing body.

The crane 10 shown in FIG. 15 is equipped with a boom foot (constituting an upper swing body) 102 capable of swinging about a vertical swing axis 101, and this boom foot 102
A telescopic boom B composed of _N boom members B _{1 to} B _N is attached to the. The boom B is configured to be rotatable (ravelable) about a horizontal rotation shaft 103, and a suspended load C is suspended by a rope 104 at the tip (boom point) thereof. In the following description, Bn
(N = 1, 2, ..., N) indicates the n-th boom member counted from the boom foot 102 side.

Outrigger jacks 105 that project laterally are disposed at four corners on the front, rear, left and right of the lower frame of the crane 10. Each outrigger jack 105
The horizontal overhang amount can be set individually.

The crane 10 includes a boom length sensor 11, a boom angle sensor 12, a cylinder pressure sensor 13, an outrigger jack horizontal extension amount sensor 14, a turning angle sensor 15, a turning angular velocity sensor 16, as shown in FIG.
And a rope length sensor 17 are provided, and detection signals of the respective sensors are input to the arithmetic and control unit 20. From the arithmetic and control unit 20, an alarm device 31, a display unit 32 having a display screen, and a turning drive are provided. Hydraulic system 33
A control signal is output to.

FIG. 2 shows a functional configuration of the arithmetic and control unit 20. The arithmetic and control unit 20 is roughly configured to perform two operations: 1) arithmetic control regarding load factor and 2) arithmetic control regarding turn of boom.

1) Functional configuration relating to calculation control of load factor In the figure, the work radius calculating means 21 operates the suspended load C from the boom length LB and the boom angle φ detected by the boom length sensor 11 and the boom angle sensor 12, respectively. The radius R is calculated. The hoisting load calculation means (constituting hoisting load detection means) 22 uses the boom length LB, the boom angle φ, and the cylinder pressure p of the boom upper detected by the cylinder pressure sensor 13 to load the hoisted load C actually hoisted. W is calculated.

The load factor calculation means 23 includes a hoisting load W of the boom B calculated by the hoisting load calculation means 22, a turning angle θ detected by the turning angle sensor 15, and an all-round rated load calculating means 24 described later. Based on the calculated rated load Wo for each turning angle θ, the ratio of the actual lifting load W to the rated load Wo, that is, the load factor W / Wo is calculated.

First warning control means (first actuation means) 29
1 outputs a control signal to the alarm device 31 to issue an alarm when the load ratio W / Wo calculated by the load ratio calculating means 23 becomes 90% or more. The first stop control means (first actuating means) 292 is configured to control the load factor W / W.
When o exceeds 100%, a control signal is output to the hydraulic system 30 to forcibly stop the crane operation except the turning operation.

By the above means, the load factor W / Wo is calculated and the safe operation is controlled based on the load factor W / Wo.

2) Functional configuration relating to arithmetic control of boom turning The all-round rated load calculating means 24 uses the working radius R and the horizontal extension amount d ₁ of each outrigger jack 105 detected by the outrigger jack horizontal extension amount sensor 14. ~
Based on d ₄ , the entire circumference rated load of the crane 10, that is, the load (rated load) Wo within a safe range at the working radius R at that time is calculated for all turning angles θ. Specifically, as shown in FIG. 3, the forward capacity calculating means 241, the outrigger jack mode determining means 242,
A lateral capacity calculating means 243, a flatness calculating means 244, an inflection angle calculating means 245, an interpolation calculating means 246, and a curve setting means 247 are provided, and the rated load Wo set here is a relational expression with the turning angle θ. It is given by Wo = f (θ).

The remaining angle calculating means 25 is for calculating the remaining angle θc at which the boom B can turn from the current position to reach the rated load curve.

The braking angular acceleration calculating means 26 includes the working radius R, the boom length LB, the boom angle φ, and the angular velocity sensor 1.
The actual braking angular acceleration β is calculated based on the angular velocity Ωo and the swing diameter 1 (L) of the suspended load which are respectively detected by 6 and the rope length sensor 17. Specifically, FIG.
Boom inertia moment calculating means 26 as shown in FIG.
1, the allowable angular acceleration calculation means 262 and the actual angular acceleration calculation means 263 are provided, and the braking angular acceleration β that does not cause the hanging load C to shake and considers the lateral bending strength of the boom B with respect to the inertial force at the time of forced stop. To calculate.

The required angle calculation means 27 calculates the angle (required angle) θr at which the boom B turns from the time the braking is started at the braking angular acceleration β until the time it is stopped, based on the angular velocity Ωo before the start of turning braking. It is a thing. The allowance angle calculation means 28 calculates the allowance angle Δθ which is the difference between the remaining angle θc and the required angle θr.

The second warning control means 293 outputs a control signal to the alarm device 31 to issue an alarm when the calculated margin angle Δθ becomes a predetermined value or less. The second stop control means (second actuating means) 294 is arranged so that the above margin angle Δ
When θ becomes 0, a control signal for the motor in the hydraulic system 33 is output to brake and stop the swing of the boom B at the braking angular acceleration β, and the first stop control means 2
A signal is sent to 92 to forcibly stop the operation in which the working radius R further increases from this point.

By the above means, the rated load curve over the entire circumference is set, and the safe operation is controlled by comparing this with the current working state.

Next, the contents of calculation and the contents of control that the arithmetic and control unit 20 actually performs will be described.

1) Arithmetic control regarding load factor The working radius calculating means 21 first finds the working radius R'which does not take into account the flexure of the boom B and the error ΔR due to the flexure of the boom B based on the boom length LB and the boom angle φ. ,
The working radius R is calculated from both. Lifting load calculation means 2
2 calculates the load W of the suspended load C actually lifted from the calculated work radius R, boom length LB, and cylinder pressure p. The full circumference load rating calculation means 24 uses the procedure described later to determine the current working radius R and the outrigger jack 10.
The rated load Wo is calculated over the entire circumference in the form of a function f (θ) of the turning angle based on the horizontal overhang amounts d _{1 to} d _{4 and the} like of FIG. Further, the load factor calculating means 23 calculates the load factor W / Wo based on the rated load Wo and the lifting load W corresponding to the current turning angle θ.

When the load factor W / Wo is 90% or more, an alarm is issued from the alarm device 31 which receives the output signal of the first alarm control means 291. It can be known that W is close to the rated load Wo. Further, when the load factor W / Wo exceeds 100%, that is, when the actual load W exceeds the rated load Wo, the crane operation excluding the turning is controlled by the output signal of the first stop control means 292 in order to prevent danger. (Boom B extension
(Looping, hoisting of the suspended load C, etc.) is forcibly stopped.

2) Boom turning calculation control The full circumference rated load calculation means 24 sets a rated load curve corresponding to the working radius R and the horizontal overhang amounts d _{1 to} d ₄ of the outrigger jacks 105.

The setting operation will be described with reference to the flowcharts of FIGS. 3 and 5 and the explanatory diagrams of FIGS. 6 to 11.

After the work radius R is calculated by the work radius calculating means 21 (step S1 in FIG. 5), first, the work radius R in FIG.
The front capacity calculation means 241 shown in FIG.
Based on, the rated load (first rated load) when the boom B is in the front-rear direction, which is a parameter indicating the forward capacity
W ₀₁ is calculated (step S2). It should be noted that the extent to which the area in front of (and behind) the crane and the area to the side of the crane are determined by the calculation of the inflection angle described later.

The first rated load W that determines this forward capacity
₀₁ is set regardless of the horizontal extension amount of each outrigger jack 105. In this embodiment, the forward capacity calculating means 241 stores the rated load W ₀₁ corresponding to the working radius R for four types of boom lengths LB as shown in FIG. 6, and based on this data, Current boom length L
A first rated load W ₀₁ suitable for B and rated load R is calculated. When the actual boom length LB does not correspond to the above four boom lengths and is a value between them, an appropriate value W is obtained by linear interpolation calculation from the values corresponding to the two boom lengths sandwiching the value. ₀₁ is required.

On the other hand, in the outrigger jack mode discriminating means 242, the present outrigger jack mode (outrigger jack overhang state) is discriminated individually on the left and right sides of the crane based on the horizontal extension amount of each outrigger jack 105 ( Step S3). As shown in FIG. 8, the horizontal overhang amount of each outrigger jack 105 is 4 in-situ (no overhang), intermediate 1 (small intermediate overhang), intermediate 2 (large intermediate overhang), and full overhang. Therefore, the outrigger jack mode corresponds to any one of the ten types of modes shown in Table 1 below.

[0036]

[Table 1]

Next, the lateral capacity calculating means 243 determines a rated load (second rated load) when the boom B is in the left-right direction, which is a parameter of the lateral capacity, by the working radius R and the outrigger jack mode. ) W ₀₂ is calculated (step S4). Specifically, this lateral capacity calculation means 243
The same data as the graph shown in FIG. 6, that is, the data regarding the rated load W ₀₂ corresponding to the working radius R is stored for each of the above 10 types of outrigger jack modes, and based on this, the second rated load is stored. Set W ₀₂ . The second rated load W ₀₂ is naturally smaller than the first rated load W ₀₁ , but the second rated load W _02
02 is not a value mainly determined by the factors of the strength of each part of the crane, but a value determined by the factors constrained by the crane toppling over due to insufficient outrigger jack overhang.

Next, based on the above two allowable radius W _02, W _01, the ratios W ₀₂ / W ₀₁ and is oblateness η is calculated by the flat rate calculation unit 244 (step S5). Then, the inflection angle of the rated load curve is obtained from the flatness ratio η and the outrigger jack mode (step S).
6).

The inflection angle means a turning angle at which, when a rated load curve is set, the curve changes from an arc having a rated load as a radius to a straight line or from a straight line to a circular arc. The inflection angles set here are the four front, rear, left, and right first boundaries that are the boundaries between the front-back direction area and the left-right direction area of the crane.
Inflection angles θ _F1 and θ _{R1 of} (always set) and
Second inflection angles θ _F2 , θ _R2 set between the inflection angles of
(There are cases where it is set and cases where it is not set).

First, the first inflection angle θ _{F1 on} the front side and the first inflection angle θ _R1 on the rear side are, as shown in FIG. It is determined by a simple one-to-one correspondence with the horizontal extension amount of the outrigger jack. For example, the front of the crane is set to θ = 0 °, and the outrigger jack 10 on the front side is set.
Assuming that the horizontal overhang amount of 5 is “in-situ” and the horizontal overhang amount of the rear outrigger jack 105 is “intermediate 2”, the first inflection angle θ _{F1 on} the front side is 5 °, and the first inflection angle on the rear side is 5 °. The first inflection angle θ _R1 is set to 180 ° −30 ° = 150 °, respectively.

In the machine in which the horizontal extension amount of the outrigger jacks can be adjusted in an analog manner, as shown in FIG. 9, a straight line drawn from the center O of the crane to the extension points P _F and P _R of the outrigger jacks is used. Based on the angle,
An angle deviated by a certain adjustment angle ψ from this may be used as the first inflection angle.

By the first inflection angles θ _F1 and θ _R1 , the work area is divided into front and rear areas and left and right areas. In the front and rear areas, an arc having the first rated load W ₀₁ is formed. It becomes the rated load curve as it is.

Next, for the left and right regions, it is first determined whether or not the second inflection angles θ _F2 and θ _R2 are set in this region.

The discrimination criteria will be described. When the points corresponding to the first inflection angles θ _F1 and θ _R1 are connected by a straight line on an arc having a radius of the first rated load W ₀₁ , the straight line is shown in FIG. As described above, there are a case where it does not intersect with an arc having the second rated load W ₀₂ as a radius and a case where it intersects, but when they do not intersect, the above straight line is set as it is as a boundary line in the left and right regions. On the other hand, when the straight line intersects an arc having the second rated load W ₀₂ as a radius, the arc shown in FIG.
As shown in, the angles corresponding to the contact points of the tangent line drawn from the points corresponding to the first inflection angles θ _F1 and θ _R1 are set as the second inflection angles θ _F2 and θ _R2 .

Although the concept of setting each inflection angle is as described above, when actually performing the calculation, the inflection angle calculating means 245 determines whether the boundary line as shown in FIG. Flatness λ at the boundary of the boundary line as shown in FIG.
In addition to storing o, the second inflection angle corresponding to each flattening ratio λ and the outrigger jack mode may be stored for the flattening ratio of the boundary flattening ratio λo or more.

After the inflection angle is set in this way,
By the interpolation calculation means 246, the ratio Wo / W between the rated load Wo and the first rated load W ₀₁ in the region where the boundary line is a straight line.
₀₁ , that is, the intermediate flatness is the first rated load W ₀₁ and the second
It is obtained by interpolation calculation based on the rated load W ₀₂ of the above (step S7). As a result, the oblateness Wo / W ₀₁ over the entire circumference as shown in the graph of FIG. 11 is obtained. The curve setting means 24 is based on the flattening ratio of the entire circumference.
7, the rated load for the entire circumference is set (step S8), whereby the setting operation of the rated load curve is completed.

The setting of the full circumference rated load based on the working radius R can be understood by the three-dimensional graph drawn on the cylindrical coordinates of R-θ-Wo as shown in FIG. The three-dimensional surface SF shown in this graph shows the rated load Wo for each working radius R and turning angle θ.
In F, the unstable region on the side of the vehicle body is, for example, when the front left and rear left outrigger jacks 105 are in the middle 2 state,
The concave surface SS is as shown in the front of the figure. Therefore,
A line of intersection (closed curve) RP between the three-dimensional surface SF and the cylinder CY having the current working radius R as a radius is a rated load curve to be obtained.

FIG. 12 shows an example of the rated load curve set as described above, and Wo in the polar coordinate system is shown.
-Defined in the θ plane. In the figure, DL is a rated load curve, and an area surrounded by the rated load curve DL, that is, an area indicated by diagonal lines is a safe work area. Load curve D
L is set individually for both the left and right sides, and is set in consideration of the difference in the amount of horizontal overhang of the front and rear outrigger jacks. Moreover, the rated load curve DL has a shape that is continuous over the entire circumference and is formed by an arc and a straight line that is easy for the user to grasp. Further, point A indicates the actual load and the turning angle at the present time as described later, and the line OA (line 40) allows the actual work situation to be understood at a glance in the work area. ing.

On the other hand, the braking angular acceleration calculating means 26 calculates the braking angular acceleration β that takes the lateral bending strength of the boom B into consideration and does not cause the shake of the load by performing the following procedure.

First, the boom inertia moment calculating means 26
1 calculates the moment of inertia In of each boom member Bn based on the following equation.

In = Ino · cos ² φ + (Wn / g) · Rn ² Here, Ino represents the moment of inertia (constant) around the center of gravity of each boom member Bn, Wn is the weight of each boom member Bn, and g is Gravity acceleration, Rn, indicates the turning radius of the center of gravity of each boom member Bn.

The allowable angular acceleration calculating means 262 calculates the allowable angular acceleration β ₁ as follows.

Generally, the boom B and the boom foot 102 of the crane 10 have sufficient strength, but when the boom length LB becomes long, a large lateral bending force is exerted on the boom B due to the inertial force generated during turning braking. Works. Since the strength burden due to the lateral bending force is maximum near the boom foot 102, the strength is evaluated here based on the moment around the turning axis 101.

Specifically, when the angular acceleration during turning braking is β ', the moment N _B acting on the center of turning of the boom B due to the turning of the boom _B is expressed by the following equation "Equation 1".

[0055]

[Equation 1]

Here, W is the lifting load calculating means 22.
It is the lifting load calculated in. Further, when the rated load related to the transverse bending strength of the boom B is Wo ′ (Wo · α ′: α ′ is a safety factor), the permissible condition for this strength is represented by the following equation “Equation 2”.

[0057]

[Equation 2]

Substituting the above equation 1 into this equation 2, the following equation is obtained.

[0059]

(Equation 3)

Therefore, the maximum angular acceleration β'that satisfies this equation "Equation 3" may be set as the allowable angular acceleration β ₁ . The rated load Wo ′ may be set to a constant value,
In consideration of the bending of the boom B and the like, it may be set to a smaller value as the boom length LB and the working radius R increase.

The actual angular acceleration calculating means 263 calculates the allowable angular acceleration β ₁ calculated in this way and the angular velocity sensor 1
6, the actual braking angular acceleration β is calculated based on the boom angular velocity (angular velocity before deceleration) Ωo obtained from the detection result of the rope length sensor 17 and the load deflection diameter l.

The calculation procedure will be described. First, consider a model of a single pendulum as shown in FIG. 13 for the suspended load C suspended from the crane 10. The differential equation of this system is given by the following equations "Equation 4" and "Equation 5".

[0063]

[Equation 4]

[0064]

V = Vo + at where η is the swing angle of the suspended load C, V is the turning speed of the boom point that changes with time t, Vo is the turning speed of the boom point before the start of turning stop (= RΩo), a indicates the acceleration. Differentiate both sides of the above equation "Equation 5" with respect to time t and substitute them into the right side of the equation "Equation 4".
= 0, dη / dt = 0), the following equation “Equation 6” is obtained.

[0065]

(Equation 6)

When this equation is expressed on the phase plane regarding η and (dη / dt) / ω, as shown in FIG.
A circle passing through the origin O (0,0) centering on (-a / g, 0) will be drawn. The time required to go around the circle, that is, the period T in which the state of the simple pendulum changes from the origin O and returns to the same state is given by T = 2π / ω, and therefore the time when the turning stop of the crane is started (point O) to time nT
If the angular acceleration β is set so as to completely stop after (n is a natural number), the crane can be stopped without leaving the swing of the suspended load when the crane is stopped. On the other hand, ω is a constant value determined by the gravitational acceleration g and the shake radius l, so the angular acceleration β at which turning can be stopped without swinging the load can be obtained from the following equation.

Β = −Ωo / nT = −ωΩo / 2nπ
(N is a natural number) Moreover, since | β | ≤ β ₁ is a condition for the transverse bending strength of the boom B, by selecting the smallest natural number n within the range satisfying this condition, the load swing can be performed in the necessary minimum time. Without, the actual braking angular acceleration β for stopping the crane can be obtained. The required angle calculation means 27 determines the turning angle required from the start of braking to the complete stop when turning is stopped at the braking angular acceleration β based on the current angular velocity (that is, the angular velocity before braking) Ωo. (Required angle)
Calculate θr. Specifically, when t the time required to complete stop from the start of braking, Ωo + βt = 0, since the two formulas θr = βt ^2/2 + Ωot is established, by eliminating t from both equations, The required angle θr can be obtained.

The allowance angle calculating means 28 calculates an angle at which the vehicle can turn at the current angular velocity Ωo before starting braking, that is, an allowance angle Δθ (= θc−θr). For example, in FIG. 12, assuming that the position where braking must be started in order to completely stop at position C is D, the above margin angle Δ
θ is the angle formed by the straight lines OA and OD.

The second stop control means 294 outputs a control signal to the hydraulic system 33 when the calculated margin angle Δθ becomes 0, for example, when the boom B reaches the position D in FIG. Thus, the turning of the boom B is braked and the operation of increasing the working radius from the present moment is forcibly stopped. At this time, in order to prevent the hanging load C from swinging, the hydraulic motor pressure P _B is set so as to stop at the braking angular acceleration β.

An example of how to calculate the hydraulic motor pressure P _B will be shown. Now, assuming that the sum of the inertia moments regarding the members of the upper swing body other than the boom B is Iu, the torque T _B required for the swing braking is given by the following expression "Equation 7".

[0071]

(Equation 7)

Here, for the acceleration β ″ of the suspended load C, η = 0 and dη / under the initial condition t = 0 according to the equations “Equation 3” and the equation “Equation 5”.
Solving with dt = 0 gives the following equation, although details will not be given here.

Β ″ = (1−cos ωt) · β On the other hand, this torque T _B has a relationship with the condition on the hydraulic motor side, which will be described in detail below, but is not described in detail here.

[0074]

(Equation 8)

Therefore, this equation "Equation 8" is replaced with the above equation "Equation 7".
The actual hydraulic motor pressure P _B can be obtained by substituting into

On the other hand, the second warning control means 293
When the allowance angle Δθ is not 0 but is equal to or less than a predetermined value, a control signal is output to the alarm device 31 to issue an alarm. This allows the operator to know that the braking will be applied automatically with only a few remaining turns.

Further, the arithmetic and control unit 20 outputs information signals concerning each value to the display unit 32, and the rated load curve DL, the present load W and the turning angle θ as shown in FIG.
In addition to the line segment 40 indicating both of the above, the lower frame position of the crane 10, the extended position of each outrigger jack 105, the equal load factor curve AL connecting the positions with a constant load factor (90% in the figure), and the like are displayed. Thereby, the operator can grasp at a glance how much the present working condition has for the rated load Wo.

At this time, the rated load curve DL is set to a regular closed curve which is continuous over the entire circumference.
Compared to the conventional one in which an irregular rated load curve that is unpredictable to the operator is set, the operator can easily grasp the drivable area without feeling a sense of discomfort. Moreover, since the rated load is set in consideration of the amount of horizontal extension of the front and rear outrigger jacks 105, the safety of the machine is reliably maintained.

Furthermore, in this device, the required angle | θr for braking and stopping the turning without leaving the swing of the suspended load C
| And the remaining angle θc at which the vehicle can turn before reaching the rated load curve are calculated, and turning braking is started by comparing the two angles. Can stop the body.
Specifically, by issuing an alarm before the two angles match, the operator is prompted to suppress the turning speed, and from the point where the two angles match, the load is not shaken automatically at the braking angular acceleration. Turn braking can be performed.

On the other hand, the load factor calculation means 23 calculates the load factor W / W.
When calculating o, it is not necessary to calculate the rated load again, and the rated load Wo calculated by the full circumference rated load calculation means 24 can be used as it is to calculate the load factor.

The present invention is not limited to the above embodiments, but the following modes can be adopted as examples.

(1) In the above embodiment, the braking is started from the time when the margin angle Δθ becomes equal to or less than the predetermined value, but the braking is performed when the angle Δθ becomes equal to or less than the predetermined value in view of the margin. You may make a call. Further, the timing of turning braking or warning may be set based on a margin time Δt obtained by dividing the margin angle Δθ by the angular velocity Ωo.

(2) In the present invention, regardless of the specific shape of the rated load curve, it may be freely set according to the working radius of the upper swing body and the overhanging state of the outrigger jack. However, as in the above embodiment, a continuous rated load curve is set over the entire circumference based on the first rated load W _01, which is a parameter of forward capacity, and the second rated load W ₀₂ , which is a parameter of lateral capacity. By doing so, it becomes possible for the operator to easily grasp the drivable area, and it is possible to realize control in which the outrigger jack is overhanging properly.

(3) The detection of the turning angular velocity in the present invention is performed by
A sensor dedicated thereto may be provided, or may be obtained from the time differential value of the turning angle sensor.

(4) In the above-described embodiment, the "triggerable support member" of the present invention is provided with the outrigger jacks which are juxtaposed to the left and right. The present invention can be applied to an overhanging one and a crawler crane including a crawler that can be extended in the width direction of the vehicle body. That is, even in such a crawler crane, when the left and right crawlers are used with different overhanging widths, the hoisting ability changes depending on the turning direction, and therefore the same excellent effect as described above can be obtained by applying the present invention. be able to.

(5) The safe operation of the first actuating means in the present invention may be a display for calling attention in addition to the above warning or forced stop operation, for example, an operation for displaying the load factor as it is. It may be.

[0087]

As described above, according to the present invention, the safe operation is performed on the basis of the angle at which the vehicle can turn before reaching the rated load curve and the required angle for stopping the turning without swinging the suspended load. Since it is designed to be controlled,
There is an effect that the upper swing body can be automatically stopped in a safe area without leaving a load shake. Moreover, when calculating the load factor and controlling the safe operation based on it, it is not necessary to calculate the rated load specially, and the rated load calculated by the all-round rated load calculation means that sets the above rated load curve is used as it is. Thus, the load factor can be calculated, which can simplify the calculation device and reduce the cost.

[Brief description of drawings]

FIG. 1 is a hardware configuration diagram showing an input / output relationship of an arithmetic and control unit provided in a crane according to an embodiment of the present invention.

FIG. 2 is a functional configuration diagram of the arithmetic and control unit.

FIG. 3 is a functional configuration diagram of an entire circumference rated load calculation means in the arithmetic and control unit.

FIG. 4 is a functional configuration diagram of a braking angular acceleration calculating means in the arithmetic and control unit.

FIG. 5 is a flowchart showing a calculation operation of the above-mentioned all-round rated load calculation means.

FIG. 6 is a graph showing a relationship between a working radius and a hoisting load stored in the all-round rated load calculating means.

FIG. 7 is a graph for explaining a rated load interpolation calculation operation performed by the all-round rated load calculation means.

FIG. 8 is an R-θ plan view showing the relationship between the amount of horizontal overhang of each outrigger jack and the first inflection angle.

FIG. 9 is a view showing another example of the method of setting the first inflection angle Wo−
FIG.

FIG. 10A is a Wo-θ plan view showing a rated load curve when the second inflection angle is not set, and FIG. 10B is a rated load curve when the second inflection angle is set. It is a Wo-theta plan view shown.

FIG. 11 is a graph showing an example of flatness ratios set over the entire circumference.

FIG. 12 shows an example of a set rated load curve Wo−
FIG.

FIG. 13 is an explanatory diagram showing a state of a suspended load as a single pendulum.

FIG. 14 is a graph showing an equation relating to a swing angle and a swing velocity of the suspended load in a phase space.

FIG. 15 is a side view of the crane.

[Explanation of symbols]

10 Crane 105 Outrigger Jack (Supporting Member) 11 Boom Length Sensor (Working Radius Detecting Means) 12 Boom Angle Sensor (Working Radius Detecting Means) 13 Cylinder Pressure Sensor (Hoisting Load Detecting Means) 14 Outrigger Jack Horizontal Overhang Quantity sensor (outrigger jack detection means) 15 Swing angle sensor (swing angle detection means) 20 Calculation control device 21 Working radius calculation means (constituting working radius detection means) 22 Lifting load calculation means (constituting lifting load detection means) 24 All Circumferential load rating calculation means 25 Remaining angle calculation means 26 Braking angular acceleration calculation means 27 Required angle calculation means 28 Margin angle calculation means (comparing means) 291 First warning control means (first actuation means) 292 First stop control means ( First operating means) 294 Second stop control means (second operating means) Boom C suspended load DL rated load curve R work radius W lifting load Wo rated load β braking angular acceleration θc remaining angle θr required angle

Claims (1)

(57) [Claims] 1. A safety device for a construction machine, comprising a swingable upper swing body and a support member capable of overhanging, and a suspended load being hung at a predetermined position of the upper swing body, the lifting load of the swing body. Lifting load detecting means for detecting, and a working radius detecting means for detecting a working radius of the upper swing body,
A swing angle detecting means for detecting the swing angle of the upper swing body, a supporting member detecting means for detecting the amount of overhang of each support member, and a rated load corresponding to the working radius and the amount of overhang of each support member for each swing angle. An all-round rated load calculating means for calculating, a load factor calculating means for calculating a load factor based on the rated load calculated by the all-round rated load calculating device, and a safe operation is performed based on the calculated load factor. First actuating means, remaining angle calculating means for calculating a remaining angle capable of turning to a point where the rated load calculated by the all-round rated load calculating means and the current lifting load match, and the swing of the hanging load. A braking angular acceleration calculating means for calculating a braking angular acceleration for braking and stopping the upper revolving superstructure, and a place for calculating the turning angle of the upper revolving superstructure necessary for braking and stopping at the braking angular acceleration. An angle calculating means, a comparing means for comparing the calculated required angle with the remaining angle, and a second operating means for starting turning braking with the braking angular acceleration while the remaining angle does not exceed the required angle. A safety device for construction machinery, which is characterized by being equipped.