JP4741834B2 - Non-stop operation control device for boom work vehicle - Google Patents

Description

  According to the present invention, a boom is configured such that the boom collapse operation can be continued without exceeding the limit value of the fall moment acting on the traveling body by performing the boom contraction operation in the middle of the boom collapse operation. The present invention relates to a non-stop operation control device for a work vehicle.

  A boom work vehicle is a vehicle equipped with a work machine at the end of a boom that is provided on a traveling body so that it can be raised, retracted, and swiveled, and the work machine is a work platform for boarding workers. A vehicle and a work machine that is a lifting device are known as crane vehicles. In such a boom work vehicle, the boom can be lifted, retracted, and swiveled by operating the boom operation lever operated by the operator, and the working machine provided at the tip of the boom is moved to a desired position and required. Can be done.

  Such a boom working vehicle is provided with an overturn prevention device that prevents the traveling body from overturning due to the overturning moment generated by the weight of the boom and the load of the work implement. Various types of fall prevention devices are known. For example, a type that prevents a fall moment acting on the traveling body and prevents it from becoming excessive (moment regulation type) is predetermined. Boom operation is prohibited such that the calculated load factor calculated as the ratio of the detected overturning moment to the allowable overturning moment exceeds the set limit load factor.

In addition to such a fall prevention device, a non-stop operation control device is known as a device for improving workability during boom collapse operation (see, for example, the following patent document). In the case of the moment regulation type, this device performs not only the boom collapse operation but also the boom contraction operation after the calculated load factor reaches a predetermined load factor smaller than the limit load factor during the boom collapse operation. Thus, the boom tip is moved downward while the calculated load factor maintains the predetermined load factor. According to such a non-stop operation control device, even when the calculated load factor reaches the limit load factor due to the boom overturning operation, the overturning operation can be continuously performed without stopping the boom operation. Therefore, workability can be improved.
JP-A-4-19159 JP 2002-265199 A

  However, in the conventional non-stop operation control described above, when the tip of the boom shifts from the arc motion so far to a linear motion (non-stop operation), the traveling direction of the tip of the boom is suddenly changed. There is a problem that a large inertial force acts on the part. When the work machine is a work board for worker boarding, the inertial force acting on the work machine gives a great shock to the worker boarded on the work board. Also, the calculated load factor may exceed the limit load factor when the boom overturning speed is high, and if the calculated load factor exceeds the limit load factor more than expected, the stability of the traveling body may decrease. Comes out.

  The present invention has been made in view of such a problem, and can prevent a large force from acting on the tip of the boom when the tip of the boom shifts from a circular motion to a straight motion. It is an object of the present invention to provide a non-stop operation control device for a boom working vehicle having a configuration capable of preventing the calculated load factor from greatly exceeding the limit load factor even when the lodging operation speed is high.

A non-stop operation control device for a boom working vehicle according to the present invention is a boom having a traveling body, a traveling body that can be raised and lowered and telescopically movable, and a work machine (for example, the work table 40 in the embodiment) at the tip. A fall moment detecting means for detecting a fall moment acting on the traveling body, and a storage means for storing an allowable fall moment set as a limit value of the fall moment acting on the running body (for example, storage of the controller 60 in the embodiment) 64) and a load factor calculating means for calculating a calculated load factor that is a ratio of the detected overturning moment to the allowable overturning moment from the detected overturning moment detected by the overturning moment detecting means and the allowable overturning moment stored in the storage means. For example, the load factor calculation unit 67) of the controller 60 in the embodiment and the boom overturning operation When it is determined that the calculated load factor calculated by the load factor calculating unit is about to reach a predetermined limit load factor, the load factor calculating unit is configured to perform the boom contraction operation in conjunction with the boom overturning operation. Non-stop operation control means (for example, the non-stop operation control unit 65 of the controller 60 in the embodiment) that moves the tip of the boom downward so that the calculated load factor calculated by the above does not exceed the limit load factor. The stop operation control unit has reached a predetermined load factor (corresponding to the second predetermined load factor γ ₂ in the embodiment) determined by the calculated load factor calculated by the load factor calculating unit being smaller than the limit load factor. Sometimes the boom contraction operation is started, and the boom contraction operation speed is changed according to the change in the calculated load factor accompanying the boom collapse operation. Going on. The tip part of the boom is a concept including a work machine.

  Here, it is preferable that the predetermined load factor is set to a value corresponding to the boom length (a smaller value as the boom length is larger). Further, the predetermined load factor is preferably set to a value corresponding to the boom operation speed of the boom (a value that decreases as the boom operation speed increases).

  Further, it is preferable that the non-stop operation control means is configured to reduce the boom operation speed before the calculated load factor calculated by the load factor calculating means reaches the limit load factor.

  In the non-stop operation control device for a boom working vehicle according to the present invention, a predetermined load factor (the embodiment) in which the calculated load factor calculated by the load factor calculating means is set to a value smaller than the limit load factor during the boom overturning operation. The boom contraction operation is started, and the boom contraction operation speed is changed in accordance with the change in the calculated load factor accompanying the boom collapse operation (specifically, Increases the contraction operation speed in accordance with the increase in the calculated load factor accompanying the boom overturning operation). For this reason, the tip of the boom that has been arcing until now smoothly moves straight through the area below the arc orbit (the calculated load factor is smaller than the limit load factor or the limit load factor above the predetermined load factor). Can be shifted to a movement that moves downward while maintaining a large load factor (corresponding to the first predetermined load factor in the embodiment), and the force (inertial force) acting on the tip of the boom is reduced. Can do. In addition, even if the work machine is a work board for worker boarding, the worker on the work table does not need to receive a big shock. In addition, since the rapid change in direction of the tip of the boom can be suppressed even when the boom overturning speed is high, the calculated load factor can be prevented from greatly exceeding the limit load factor.

  Here, if the predetermined load factor (corresponding to the second predetermined load factor in the embodiment) is set to a value corresponding to the boom length (the smaller the boom length, the smaller the value). As the boom length increases, the boom contraction start position becomes earlier, so that the tip of the boom that has been performing the arc motion can be smoothly shifted to the straight motion regardless of the boom length. .

  Further, the predetermined load factor (corresponding to the second predetermined load factor in the embodiment) is set to a value corresponding to the boom overturning operation speed (a smaller value as the boom overturning operation speed is larger). For example, it is possible to smoothly shift the tip end portion of the boom that has been performing the arc motion to the linear motion.

  Further, if the non-stop operation control means is configured to reduce the boom operation speed before the calculated load factor calculated by the load factor calculation means reaches the limit load factor, the boom operation speed is reduced. Is relatively large, the boom tip can be smoothly placed on the predetermined load factor line (corresponding to the first predetermined load factor line in the embodiment).

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows a crawler type aerial work vehicle 1 to which a non-stop operation control device according to an embodiment of the present invention is applied. The aerial work vehicle 1 has a revolving body 20 on an upper portion of a traveling body (crawler traveling body) 10, and a boom (extensible boom) 30 is attached to the upper portion of the revolving body 20 via a foot pin 23 so as to be raised and lowered. It has a configuration.

  The revolving unit 20 can be swung within a range of 360 degrees in a horizontal plane with respect to the traveling unit 10 by rotating a revolving motor (hydraulic motor) 21 provided inside the revolving unit 20, and the boom 30 can be revolved. The swinging body 20 can be raised and lowered by extending and contracting a lifting cylinder (hydraulic cylinder) 22 provided between the body 20 and the body 20. The boom 30 includes a proximal boom 30a, an intermediate boom 30b, and a distal boom 30c. The boom 30 is telescopically moved by extending and contracting a telescopic cylinder (hydraulic cylinder) 31 provided inside the boom 30. Can be made.

  A vertical post 32 is provided at the tip of the boom 30, and a work table 40 for boarding an operator is rotatably attached to the vertical post 32. The work table 40 can be swung in a horizontal plane with respect to the vertical post 32 by rotating a swing motor (hydraulic motor) 41 provided in the work table 40. Since the vertical post 32 is always held in a vertical posture by a balancing device (not shown), as a result, the floor surface of the work table 40 is always kept in a horizontal posture.

  The work table 40 is provided with an upper operation device 50, which includes a boom operation lever 51 that performs the raising / lowering, expansion / contraction, and turning operations of the boom 30, and a work table operation lever 52 that performs the swing operation of the work table 40. Is provided (see FIG. 1). For this reason, the operator (operator) OP who has boarded the work table 40 operates the boom operation lever 51 to raise, lower, expand, and rotate the boom 30, and operates the work table operation lever 52 to move the work table 40 to the vertical post. By swinging around 32, it is possible to freely move the work table 40 on which it is placed and perform work at a desired position at a desired position.

  The traveling body 10 includes one crawler traveling device 12 on each of the left and right sides of the frame 11. Each crawler traveling device 12 includes an activation wheel 12a attached to the rear part of the frame 11, an idler wheel 12b attached to the front part of the frame 11, and a crawler belt 12c wound around the activation wheel 12a and the idler wheel 12b. It is comprised. Each starter wheel 12a of the left and right crawler travel devices 12 is driven by rotating a sprocket (not shown) by travel motors (hydraulic motors) 13 and 14 (only the left travel motor 13 is shown in FIG. 2) attached to the frame 11. The left and right traveling motors 13 and 14 can be rotated and stopped as desired by operating the traveling operation levers 53 and 54 (see FIG. 1) provided in the upper operating device 50. it can.

  As shown in FIG. 1, the hydraulic pump P provided in the traveling body 10 is driven by a power source (not shown) such as an engine or an electric motor, and the hydraulic oil discharged from the hydraulic pump P controls the operation of the hoisting cylinder 22. Undulation cylinder control valve V1 to perform, telescopic cylinder control valve V2 to control the operation of the telescopic cylinder 31, swing motor control valve V3 to control the operation of the swing motor 21, swing motor control valve V4 to control the operation of the swing motor 41 And corresponding hydraulic actuators (the hoisting cylinder 22, the telescopic cylinder 31, the swing motor 21, the swinging motor 41, and the left and right traveling motors 13, via the traveling motor control valves V5, V6 for controlling the operation of the left and right traveling motors 13, 14. 14).

  When the boom operation lever 51 or the work table operation lever 52 is operated by the operator OP on the work table 40, voltage signals corresponding to the operation direction (tilt direction) and the operation amount (tilt amount) of the lever are output. This is input to the valve operation control unit 61 of the controller 60. The valve operation control unit 61 of the controller 60 then controls each spool (not shown) of the control valves V1, V2, V3, V4 corresponding to the direction and amount corresponding to the voltage signal output by operating the levers 51, 52. ) Is electromagnetically driven. Here, the drive direction of each spool of the control valves V1, V2, V3, V4 is related to the drive direction (extension or contraction or rotation direction) of the corresponding hydraulic actuator, and the drive amount of each spool is supplied to the corresponding hydraulic actuator. This is related to the flow rate of hydraulic oil (flow rate per unit time), that is, the operating speed of each hydraulic actuator. Therefore, when the drive direction of the spool of each control valve is reversed, the operation direction of the corresponding hydraulic actuator is reversed, and the operation speed of the corresponding hydraulic actuator increases as the drive amount of the spool of each control valve increases.

  Here, the voltage level of the voltage signal output by the operation of the boom operation lever 51 or the swing operation lever 52 is substantially proportional to the operation amount, and the operator OP operates the operation amounts of the operation levers 51 and 52. The operating speed of the corresponding hydraulic actuator can be freely adjusted by adjusting.

  Further, when the left and right traveling operation levers 53 and 54 are operated by the operator OP, voltage signals corresponding to the operation direction (tilting direction) and the operation amount (tilting amount) are output, respectively, and the valve operation control unit of the controller 60 is output. 61 is input. The valve operation control unit 61 then controls the spools (not shown) of the left and right traveling motor control valves V5 and V6 corresponding in the direction and amount according to the voltage signal output by the operation of the traveling operation levers 53 and 54. ) Is electromagnetically driven. Here, the drive directions of the spools of the control valves V5 and V6 are related to the rotation directions of the corresponding travel motors 13 and 14, and the drive amount of each spool is the flow rate of hydraulic oil supplied to the travel motors 13 and 14 ( (Flow rate per unit time), that is, the rotational speed (rotational speed) of the traveling motors 13 and 14. Therefore, when the drive direction of the spool of the control valve is reversed, the operation direction of the corresponding travel motors 13 and 14 is reversed, and the operation speed of the corresponding travel motors 13 and 14 increases as the drive amount of the spool of each control valve increases. growing.

  Here, the voltage level of the voltage signal output by the operation of the left and right traveling operation levers 53 and 54 is substantially proportional to the operation amount, and is output if the operation amounts of the left and right traveling operation levers 53 and 54 are the same. The voltage level is the same. For this reason, the operator OP can travel straight or turn by freely adjusting the rotational speeds of the left and right traveling motors 13 and 14 by adjusting the operation amount of the traveling operation levers 53 and 54. The turn travel includes a pivot turn (swivel turn with a small radius) and a spin turn (turn on the spot). One of the left and right crawler travel devices 12 is (almost) fixed and the other is forward or A pivot turn can be made by rotating in the opposite direction, and a spin turn can be made by rotating the left and right crawler travel devices 12 in different directions.

  In addition, as shown in FIGS. 2 and 1, the work platform 1 includes a hoisting angle detector 81 that detects the hoisting angle θ of the boom 30 (see FIG. 3), and a length L of the boom 30 (FIG. 3). A length detector 82 for detecting a reference) and a turning angle detector 83 for detecting a turning angle (of the turning body 20) of the boom 30 are provided, and the boom 30 detected by these detectors 81, 82, 83 is provided. Each information of the undulation angle θ, the length L, and the turning angle is input to the position calculation unit 62 of the controller 60 (see FIG. 1). Here, the position calculation unit 62 of the controller 60 is based on the information from the detectors 81, 82, and 83, and the tip of the boom 30 based on the traveling body 10 (the tip of the boom 30 is the work table 40. The position of the boom tip is calculated together with the information detected by the detectors 81, 82, 83 together with the information on the position of the boom tip obtained as a result. It outputs to the regulation control part 63 (refer FIG. 1).

  The undulation angle detector 81, the length detector 82, the turning angle detector 83, and the position calculation unit 62 of the controller 60 have a function of detecting the position (coordinates) of the boom tip portion. This is referred to as position detecting means 80. The position detection means 80 directly obtains the position of the boom tip at the turning angle of a certain boom 30 as coordinates (θ, L), but the working radius R of the boom 30 (as shown in FIG. 3). The horizontal distance from the vertical line PL including the foot pin 23 to the front end BP of the boom 30 and the height H of the front end of the boom 30 (the front end of the boom 30 from the horizontal line WL including the foot pin 23 as shown in FIG. 3). Since the height of the BP can be expressed using θ and L, respectively, it is possible to obtain the position of the boom tip as coordinates (R, H).

As shown in FIG. 1, in addition to the above-described valve operation control unit 61, position calculation unit 62, and restriction control unit 63, the controller 60 stores a storage unit 64, a non-stop operation control unit 65, a tipping moment calculation unit 66, and a load factor calculation. A portion 67 is provided. The storage unit 64 of the controller 60 stores an allowable overturning moment M ₀ set as a limit value of the overturning moment acting on the traveling body 10 as a value corresponding to the undulation angle θ and the length L of the boom 30. Further, the overturning moment calculation unit 66 of the controller 60 travels based on the detection information from the axial force detector 84 (see FIG. 1) that detects the axial force of the undulation cylinder 22 and the detection information from the undulation angle detector 81. A falling moment M acting on the body 10 is calculated. The axial force detector 84, the undulation angle detector 81, and the overturning moment calculation unit 66 of the controller 60 have a function of detecting the overturning moment acting on the traveling body 10 (the detected overturning moment is set as the detected overturning moment M). These are hereinafter referred to as a tipping moment detecting means 90 as a set.

The load factor calculation unit 67 of the controller 60 includes an allowable overturning moment determined according to the detected overturning moment M detected by the overturning moment detecting means 90 and the undulation angle θ and the length L of the boom 30 detected at that time. From M ₀ , a calculated load factor γ (= M / M ₀ ), which is a ratio of the detected overturning moment M to the allowable overturning moment M ₀ , is calculated, and the result is sent to the restriction control unit 63 and the non-stop operation control unit 65. Output.

The calculated load factor γ calculated (monitored) by the load factor calculating unit 67 of the controller 60 varies according to the posture of the boom 30 (the position of the tip of the boom) and the load on the work table 40, and has a large value. It shows that the degree of instability with respect to falls is increasing. However, since the operation of the boom 30 such that the calculated load factor γ exceeds a predetermined limit load factor γ ₀ (for example, 100%) is regulated by the regulation control unit 63 of the controller 60 as described later, the calculated load factor γ does not increase beyond the limit load factor γ ₀ .

FIG. 3 shows an outer edge of a region where the tip of the boom 30 can be moved when the load on the work table 40 takes a certain value. At this outer edge, the straight line L1, the straight line L2, the curve L3, and the curve L4 are outer edges (operation limit lines) that are naturally defined from the relationship between the range that the boom 30 can take and the range that the boom 30 can take up and down. The straight line Lγ ₀ is a line formed by plotting the position of the tip of the boom for each length of the boom 30 when the calculated load factor γ becomes the limit load factor γ ₀ (this line is the limit load factor γ _0). Called rate line). A curved line L4 ′ indicated by a dotted line indicates that the tip of the boom 30 assumes that the calculated load factor γ is allowed to exceed the limit load factor γ ₀ when the boom 30 in the maximum extension state is laid down. It is a virtual operating limit line that the part will draw. That is, the region between the limit load factor line Eruganma ₀ and the virtual operating limit line L4 'is the area (structural movement of the tip of the boom 30 is prohibited may move the tip of the boom 30, Since the restriction control unit 63 works so that the calculated load factor γ does not exceed the limit load factor γ ₀ , the end of the boom 30 cannot move as a result), and the limit load factor line Lγ ₀ is the boom. It can also be referred to as a boundary line with the region where the movement of the tip portion of 30 is prohibited. Of course, even if the set value of the limit load factor γ ₀ is the same, the position of the limit load factor line Lγ ₀ changes according to the load on the work table 40, and the load on the work table 40 is large. Sometimes the limit load factor line Lγ ₀ moves to the side closer to the traveling body 10 (the right side of the figure in FIG. 3). Further, even when the work load of the work table 40 is the same, the limit load factor line Lγ ₀ moves to the side away from the traveling body 10 (the left side of the drawing in FIG. 3) when the set limit load factor γ ₀ is large. Will do.

When the loading load of the work table 40 takes a certain value, when the boom 30 is extended or laid down, the value of the calculated load factor γ calculated by the load factor calculating unit 67 gradually increases. To go. Here, when the operation of the boom 30 without the overturning operation (for example, the simple extension operation of the boom 30) is performed, and the value of the calculated load factor γ reaches the limit load factor γ ₀ (this is may be the tip of the boom 30 is seen to have reached the limit load factor line Lγ _0), the operation of the boom 30 is stopped. Such restriction of the boom 30 is performed by the restriction control unit 63 of the controller 60. That is, the restriction control unit 63 of the controller 60 functions to prohibit the operation of the boom 30 such that the calculated load factor γ calculated by the load factor calculating unit 67 exceeds the limit load factor γ ₀ .

The non-stop operation control unit 65 of the controller 60 is such that the calculated load factor γ calculated (monitored) by the load factor calculation unit 67 of the controller 60 reaches the limit load factor γ ₀ during the lying down operation of the boom 30. When it is determined that the boom 30 is tilted, the boom 30 is contracted and the boom 30 is contracted to move the tip of the boom 30 downward so that the calculated load factor γ does not exceed the limit load factor γ ₀ . . Specifically, the boom 30 in a state that the calculated load ratio gamma maintains the first predetermined load ratio gamma ₁ determined as a value smaller than the same or limit load factor gamma ₀ and the limit load factor gamma ₀ (e.g. 98%) (See FIG. 4. Hereinafter, such control is referred to as non-stop operation control). Note that the alternate long and short dash line in FIG. 4 indicates the locus (hereinafter referred to as the first line) drawn by the tip of the boom 30 when the boom 30 is operated in a state where the calculated load factor γ maintains the _first predetermined load factor γ 1. A predetermined load factor line Lγ ₁ ).

In a case where the non-stop operation control unit 65 of the controller 60 does not perform such non-stop operation control, in the above case, when the calculated load factor γ reaches the limit load factor γ ₀ due to the collapse operation of the boom 30, the controller 60. The operation of the boom 30 is forcibly stopped by the restriction control unit 63, but the non-stop operation control unit 65 of the controller 60 performs the non-stop operation control as described above, so that the outer end of the boom 30 is removed. Although the movement to the direction (the side away from the traveling body 10) is restricted, the operation of overturning the boom 30 intended by the operator OP can be continued, so that workability is improved.

The non-stop operation control unit 65 of the controller 60 detects that the boom 30 is in the inclining operation, which is a condition for starting the non-stop operation control, detected by the position detection means 80 (monitored). ) Based on the movement trajectory of the tip of the boom 30, or by detecting the operation state of the boom operation lever 51. Whether or not the calculated load factor γ is about to reach the limit load factor γ ₀ is determined by the calculated load factor γ calculated (monitored) by the load factor calculating unit 67 of the controller 60. This is performed based on whether or not a _second predetermined load factor γ ₂ (for example, near 90%) predetermined as a value smaller than the predetermined load factor γ ₁ has been reached. Note that the data of the _first predetermined load factor γ _{1 and} the data of the second predetermined load factor γ ₂ are stored in advance in the storage unit 64 of the controller 60.

When the non-stop operation control unit 65 of the controller 60 determines that the calculated load factor γ is about to reach the limit load factor γ ₀ during the tilting operation of the boom 30 as described above, the non-stop operation control unit 65 operates the telescopic cylinder 31. initiates contraction operation of the boom 30 Te (the starting point P ₁ to a point on the trajectory m to initiate contraction operation of the boom 30. see FIG. 4). Further, if necessary, control for lowering the falling operation speed of the boom 30 is also started. After starting the contraction operation of the boom 30 in this way, the tip of the boom 30 passes through the lower region of the track m previously drawn (for example, in the curved track n as shown in FIG. 4 or in FIG. The boom 30 is actuated so as to reach the first predetermined load factor line Lγ ₁ (with a linear trajectory n as shown). At this time, the non-stop operation control unit 65 of the controller 60 changes the contraction operation speed of the boom 30 according to the change of the calculated load factor γ accompanying the fall operation of the boom 30. Specifically, the contraction operation speed of the boom 30 is increased in accordance with the increase of the calculated load factor γ accompanying the overturning operation of the boom 30. As a result, the tip of the boom 30 moves along the first predetermined load factor curve Lγ ₁ while drawing a smooth track, and thereafter moves downward along the first predetermined load factor line Lγ ₁ . A point P ₀ shown in FIG. 4 is drawn by the tip of the boom 30 when it is assumed that the boom 30 has not been contracted until the tip of the boom 30 reaches the first predetermined load factor line Lγ _1. The intersection of the virtual trajectory m ′ and the first predetermined load factor line Lγ ₁ , and the point P ₂ is the point where the trajectory n and the first predetermined load factor line Lγ ₁ intersect.

During the tilting operation of the boom 30, the boom 30 is tilted until the calculated load factor γ calculated (monitored) by the load factor calculating unit 67 of the controller 60 reaches the second predetermined load factor γ _2. Only the operation is performed, but the boom 30 is in a sloping operation until the calculated load factor γ reaches the first predetermined load factor γ ₁ after the calculated load factor γ reaches the _second predetermined load factor γ _2. In addition to the above, the contraction operation is performed (the lodging operation and the contraction operation are performed in conjunction with each other). Even after the calculated load factor γ reaches the first predetermined load factor γ ₁ , the boom 30 is contracted in addition to the overturning operation, but the calculated load factor γ is equal to the first predetermined load factor γ ₁ . The contraction operation speed of the boom 30 during the downward movement in the maintained state needs to be larger than the contraction operation speed of the boom 30 until the calculated load factor γ reaches the first predetermined load factor γ _1. is there. This is because, in FIG. 4, the distance that the tip of the boom 30 moving in the region until the calculated load factor γ reaches the first predetermined load factor γ ₁ moves away from the virtual track m ′, and the calculated load factor. During movement in a state where γ is maintained at the first predetermined load factor γ ₁ (moving along the first predetermined load factor line Lγ ₁ ), the tip of the boom 30 moves away from the virtual track m ′. When the distance is compared, the latter can be easily inferred because it is larger than the former. As described above, as long as the calculated load factor γ reaches the first predetermined load factor γ ₁ and while the calculated load factor γ is maintained at the _first predetermined load factor γ ₁ as necessary. Thus, control is performed to reduce the falling operation speed of the boom 30 (in accordance with the contraction operation speed of the boom 30).

FIG. 5 is a graph showing the contraction operation speed of the boom 30 with respect to the calculated load factor γ during the collapse operation of the boom 30. This graph is for the length of a certain boom 30 and the overturning operation speed. Thus, when the calculated load factor γ is smaller than the second predetermined load factor γ ₂ , the contraction operation speed of the boom 30 is reduced to zero. When the calculated load factor γ increases beyond the _second predetermined load factor γ ₂ , the tendency to increase the contraction operation speed of the boom 30 as the calculated load factor γ increases is the length of the boom 30 or the collapse of the boom 30. The same regardless of the operating speed.

Thus, non-stop operation control device according to the present embodiment, in lodging operation of the boom 30, calculated load ratio gamma than the limit load factor gamma ₀ (even this limit load factor gamma ₀ is smaller than a first predetermined It starts the contraction operation of the boom 30 upon reaching a predetermined load ratio defined as) smaller than the load factor gamma ₁ (second predetermined load ratio gamma _2), calculation load accompanying the lodging operation of the boom 30 The contraction operation speed of the boom 30 is changed in accordance with the change in the rate γ (specifically, the contraction operation speed is increased in accordance with the increase in the calculated load factor γ accompanying the overturning operation of the boom 30). . For this reason, the tip of the boom 30 that has been arcing until then smoothly moves straight through the region below the arcuate track (moving downward while maintaining the _first predetermined load factor γ ₁ ). Thus, the force (inertial force) acting on the tip of the boom 30 can be reduced. In addition, the OP on the work table 40 does not receive a large shock. Further, since the rapid change in the direction of the tip of the boom 30 can be suppressed even when the boom 30 is operating at a high speed, the calculated load factor γ is equal to the first predetermined load factor γ ₁ (that is, the limit load factor γ _0). )) Can be prevented.

Here, the second predetermined load factor γ ₂ is set to a value corresponding to the length of the boom 30 detected by the length detector 82 (a smaller value as the length of the boom 30 is larger). It has become. For this reason, as the length of the boom 30 is increased, the start position of the boom 30 contraction operation becomes earlier (started from a position away from the first predetermined load factor line Lγ ₁ ). Regardless of this, it is possible to smoothly shift the distal end portion of the boom 30 that has been performing the arc motion to the linear motion. As a result, after the calculated load factor γ reaches the second predetermined load factor γ ₂ , the tip portion of the boom 30 moves along a smooth trajectory in a region below the track m, and the calculated load factor γ becomes the first predetermined load factor γ. It moves downward while maintaining the load factor γ ₁ (this can be considered that the tip of the boom 30 has moved downward along the first predetermined load factor line Lγ ₁ ). In addition, when the point which becomes _2nd predetermined load factor (gamma) ₂ is plotted for every length of the boom 30, it will become like the broken line shown in FIG. 3 (this line is called 2nd predetermined load factor line L (gamma) ₂ ). The second predetermined load ratio line Eruganma _2, in the first traveling body 10 side in the region than the predetermined load ratio line Eruganma _1, the distance from the first predetermined load ratio line Eruganma ₁ away inwardly (vehicle 10 side) In addition, the distance increases as the distance in the height direction increases.

Further, as described above, the second predetermined load factor γ ₂ is set to a value corresponding to the length of the boom 30 (a smaller value as the length of the boom 30 is larger), thereby calculating the calculated load factor γ. Can be effectively prevented from exceeding the first predetermined load factor γ ₁ (the tip of the boom 30 overshoots the first predetermined load factor line Lγ ₁ ). This is because, as shown in FIG. 6, track m the tip of the boom 30 has a lodging actuated drawn by the cross angle α when intersecting the first predetermined load ratio line Eruganma _1, the first predetermined load ratio line Eruganma as when the height of the boom 30 when intersecting the ₁ is large (when a large length of the boom 30) increases, so will not intersect smooth the track m and the first predetermined load ratio line Eruganma _1, the start point P ₁ The calculated load factor γ is not the first predetermined load factor line Lγ ₁ (the start point P ₁ is set earlier, ie, the calculated load factor γ when the start point P ₁ is set is not reduced). This is because the predetermined load factor γ ₁ is easily exceeded.

Further, the second predetermined load factor γ ₂ is set to a value corresponding to the lowering operation speed of the boom 30 (a smaller value as the lowering operation speed of the boom 30 is larger). Since the inertial force acting on the tip of the boom 30 is greater as the boom 30 is operated at a higher speed (if the boom 30 is the same length), the starting point P ₁ is increased as the boom 30 is operated at a higher speed. Is separated from the first predetermined load factor line Lγ ₁ (the start point P ₁ is set earlier, ie, the calculated load factor γ when the start point P ₁ is set is reduced) (FIG. 7). reference). As a result, the tip of the boom 30 that has been moving in a circular arc can be smoothly shifted to a straight movement, and the calculated load factor γ exceeds the first predetermined load factor γ ₁ (the tip of the boom 30 is the first It is possible to effectively prevent a situation in which one predetermined load factor line Lγ ₁ is overshooted. FIG. 8A is a graph showing the relationship between the lowering operation speed of the boom 30 and the second predetermined load factor γ _2, and FIG. 8B corresponds to the magnitude of the lowering operation speed of the boom 30. 6 is a graph showing how the relationship of the contraction operation speed of the boom 30 to the calculated load factor γ (the relationship shown in FIG. 5) changes.

The drive signals (voltage signals) of the control valves V1, V2, and V3 output from the valve operation control unit 61 of the controller 60 are also input to the non-stop operation control unit 65 of the controller 60. 65 detects the lowering operation speed of the boom 30 based on the drive signal of the hoisting cylinder control valve V1 among these drive signals. This is because as the drive signal (voltage level) of the undulation cylinder control valve V1 is larger, the drive amount of the spool of the undulation cylinder control valve V1 is larger, and the flow rate of hydraulic oil supplied to the undulation cylinder 22 (flow rate per unit time) ) Increases and the operating speed of the undulating cylinder 22 increases. Therefore, γ ₂ in FIG. 8A can also be defined by the relationship between the drive signal of the hoisting cylinder control valve or the operation control signal of the hoisting cylinder, and the horizontal axis of FIG. The shape of the graph also has the same tendency as that of FIG. Then, the non-stop operation control unit 65 of the controller 60 calls the data of the second predetermined load factor γ ₂ corresponding to the detected boom 30 operation speed from the storage unit 64 and uses it for non-stop operation control. In this case, the valve operation control unit 61 of the controller 60 functions as a boom overturning operation speed detecting means for detecting the overturning operation speed of the boom 30.

In addition, the boom 30 is operated at the rate of change in time (dθ / dt) of the boom 30 undulation angle detected by the undulation angle detector 81 that detects the boom 30 undulation angle, and the working radius R of the boom 30. It can be obtained from the rate of change (dR / dt) or the time rate of change (dH / dt) of the boom tip height H, and the time rate of change (dγ / dt) of the calculated load rate γ, and the boom 30 is operated up and down. Since it can also be obtained from the output and operating speed of the hoisting cylinder 22 or the operation amount of the boom operation lever 51 that issues the hoisting operation command of the boom 30, γ ₂ can also be defined in relation to any of these. At this time, the horizontal axis of FIG. 8A represents “time change rate of boom hoisting angle”, “time change rate of boom working radius”, “time change rate of boom tip height”, “calculated load rate of If the “time change rate”, “output of the hoisting cylinder”, “operating speed of the hoisting cylinder” or “the amount of operation of the boom operation lever” are used, the shape of the graph has the same tendency as in FIG.

Further, the non-stop operation control unit 65 of the controller 60 has a calculation load factor γ calculated by the load factor calculation unit 67 of the controller 60 before reaching the limit load factor γ ₀ (and is smaller than the limit load factor γ _0). Before the first predetermined load factor γ ₁ is reached, the lowering operation speed of the boom 30 is reduced. Specifically, while the contraction operation speed of the boom 30 is still low, such as immediately after the contraction operation of the boom 30 is started, the fall operation speed of the boom 30 is decreased. This is because when the falling operation speed of the boom 30 is relatively high, the tip end portion of the boom 30 cannot be put on the target track even if the contraction speed of the boom 30 is increased to the limit while maintaining the falling operation speed. Because there are cases. In such a case, the lowering operation speed of the boom 30 is made lower than the command value by the boom operation lever 51 (corresponding to the tilting amount of the boom operation lever 51), and the lowering operation speed of the boom 30 is lowered. It is possible to prevent the calculated load factor γ from exceeding the _first predetermined load factor γ ₁ by balancing with the contraction operation speed. Thereby, even if the falling operation speed of the boom 30 is relatively high, the tip of the boom 30 can be smoothly placed on the first predetermined load factor line Lγ ₁ . Here, adjustment of the lowering operation speed of the boom 30 is performed by adjusting the output of the hoisting cylinder 22, the operation speed, and the like. The timing at which the lowering operation speed of the boom 30 starts to be lowered can be arbitrarily set according to the change rate of the calculated load factor γ.

  Although the preferred embodiments of the present invention have been described so far, the scope of the present invention is not limited to those shown in the above-described embodiments. For example, in the above-described embodiment, the subject to which the present invention is applied is an aerial work vehicle whose traveling body is a crawler type, but the traveling body may not necessarily be a crawler type. In addition, the object to which the present invention is applied is not necessarily an aerial work vehicle, but a boom work vehicle configured to have a working machine at the tip of a boom provided on a traveling body so as to be able to undulate and expand and contract. Any other boom working vehicle (for example, a crane truck or a digging pillar car) may be used.

It is a drive control system diagram of a hydraulic actuator in a crawler type aerial work vehicle to which a non-stop operation control device according to an embodiment of the present invention is applied. It is a side view of the said crawler type aerial work vehicle. It is a figure which shows the outer edge of the area | region which can move the front-end | tip part of a boom, when the loading load of a work bench has taken a certain value. It is a figure which shows an example of the movement locus | trajectory of a boom front-end | tip part after starting the shrinking | contraction operation | movement of a boom, and is an enlarged view of the area | region IV shown in FIG. It is a graph which shows the shrinkage | contraction operation speed of the boom with respect to the calculation load factor (gamma) at the time of the boom fall operation | movement. It is a figure which shows a mode that the crossing angle | corner (alpha) when the track | orbit m drawn by the front-end | tip part of the boom which is carrying out the fall operation cross | intersects the 1st predetermined load factor line L (gamma) ₁ becomes so small that the length of a boom is small. When the boom length is the same, it is a figure which shows a mode that _2nd predetermined load factor (gamma) ₂ is set to a small value, so that the fall operation speed of a boom is large. (A) is a graph showing the relationship between the boom operation speed and the second predetermined load factor γ ₂ when the boom length is the same, and (B) is the boom operation speed. It is a graph showing how the relationship of the boom contraction operation speed with respect to the calculated load factor γ changes according to the magnitude of.

Explanation of symbols

1 High-altitude work vehicle (boom work vehicle)
10 traveling body 30 boom 40 work table (work machine)
51 Boom operation lever 60 Controller 61 Valve operation control unit 63 Restriction control unit 64 Storage unit (storage means)
65 Non-stop operation control unit (non-stop operation control means)
67 Load factor calculation unit (load factor calculation means)
90 Falling moment detection means

Claims (3)

A traveling body,
A boom that is provided on the traveling body so as to freely undulate and expand and contract, and has a working machine at a tip portion;
A fall moment detecting means for detecting a fall moment acting on the traveling body;
Storage means for storing an allowable fall moment set as a limit value of the fall moment acting on the traveling body;
Load factor calculating means for calculating a calculated load factor that is a ratio of the detected overturning moment to the allowable overturning moment from the detected overturning moment detected in the overturning moment detecting means and the allowable overturning moment stored in the storage means;
When it is determined that the calculated load factor calculated by the load factor calculating unit is about to reach a predetermined limit load factor during the boom overturning operation, the boom contracting operation is performed together with the boom overturning operation. Non-stop operation control means for moving the tip of the boom downward so that the calculated load factor calculated by the load factor calculating means does not exceed the limit load factor.
The non-stop operation control means starts the boom contraction operation when the calculated load factor calculated by the load factor calculating means reaches a predetermined load factor determined as a value smaller than the limit load factor. , Increasing the contraction operation speed of the boom in accordance with the increase of the calculated load factor accompanying the overturning operation of the boom ,
The non-stop operation control device for a boom working vehicle, wherein the predetermined load factor is set to a smaller value as the boom length is longer . A traveling body,
A boom that is provided on the traveling body so as to freely undulate and expand and contract, and has a working machine at a tip portion;
A fall moment detecting means for detecting a fall moment acting on the traveling body;
Storage means for storing an allowable fall moment set as a limit value of the fall moment acting on the traveling body;
Load factor calculating means for calculating a calculated load factor that is a ratio of the detected overturning moment to the allowable overturning moment from the detected overturning moment detected in the overturning moment detecting means and the allowable overturning moment stored in the storage means;
When it is determined that the calculated load factor calculated by the load factor calculating unit is about to reach a predetermined limit load factor during the boom overturning operation, the boom contracting operation is performed together with the boom overturning operation. Non-stop operation control means for moving the tip of the boom downward so that the calculated load factor calculated by the load factor calculating means does not exceed the limit load factor.
The non-stop operation control means starts the boom contraction operation when the calculated load factor calculated by the load factor calculating means reaches a predetermined load factor determined as a value smaller than the limit load factor. , Increasing the contraction operation speed of the boom in accordance with the increase of the calculated load factor accompanying the overturning operation of the boom,
The non-stop operation control device for a boom working vehicle, wherein the predetermined load factor is set to a smaller value as the boom operation speed is higher . The non-stop operation control means according to claim 1 or 2, characterized in that reducing the lodging operating speed of the boom before calculating the load rate calculated by the load factor calculating means reaches the limit load factor Non-stop operation control device for boom working vehicle.

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