JPH06263394A - Control device for working vehicle incorporating boom - Google Patents

Abstract

PURPOSE:To consist the reduction of a shock upon stopping during deceleration control with a large hoisting angle, with a rapidness of working during decelera tion at a small hoisting angle by carrying out the deceleration control during boom swing down operation, in relation to a boom hoisting angle. CONSTITUTION:A maximum speed during boom swing down operation is limited in accordance with a maximum speed limiting signal delivered from a speed limiting signal output means 66. In this case a speed limit initiation time setting means 67 receives signals corresponding to a boom hoisting angle, delivered from boom hoisting angle detecting means 70, 14 so as to set the predetermined value of an approaching rate to a value nearer to the low approaching as the boom hoisting angle is larger. Accordingly, during the boom swing down operation in a large hoisting angle range, the speed limiting range is enlarged by a value with which the deceleration control is initiated near to the low approaching so that abrupt deceleration is prevented. On the contrary, during boom swing down operation in a small hoisting angle range, the speed limiting range is decreased by a value with which the deceleration control is initiated near to the high approaching.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a work vehicle with a boom, and a control device for decelerating and stopping the fall motion of a special boom based on its limit performance.

[0002]

2. Description of the Related Art Conventionally, in a work vehicle with a boom such as a crane vehicle with a boom, from the viewpoint of preventing the crane vehicle from toppling over due to overload work, for example, a predetermined crane is required when the boom is being laid down. The relative relationship between the limit performance (for example, allowable moment value) of the vehicle and the current load state (actual moment value) is continuously monitored, and when the approach rate of the actual moment value to the allowable moment value reaches 100% or more. A predetermined stop signal is output to immediately stop the operation of the boom in the fall direction.

On the other hand, if the boom suddenly stops at the time of this overload stop, it is expected that it will be in a dangerous state due to its inertial force of fall, and if a large stop shock occurs, the psychological effect on the driver will be great, Approach rate is 10
It is also known to perform a so-called maximum speed limit control in which the operating speed of the boom fall-down operation is gradually reduced from the state before reaching 0%, for example, the approach rate of 90%, and is slowly stopped at the approach rate of 100%. ing.

[0004]

However, in the conventional maximum speed limit control, the approach rate, which is the reference for the speed limitation, is set to a constant value (for example, 90% approach rate) regardless of the hoisting angle of the boom. Therefore, there was a problem as described below. That is, the change rate of the working radius with respect to the hoisting angle is large in the region where the boom hoisting angle is large, and conversely, it is small in the region where the boom hoisting angle is small. For this reason, the change state of the actual moment value, whose working radius is the main controlling factor, changes significantly according to the boom hoisting angle, and in the large hoisting angle region, a slight change in the hoisting angle changes the actual moment value to the limit moment value. The approach rate increases sharply, resulting in a sharp deceleration, and a relatively large stop shock is generated. On the other hand, in the small undulation angle region, the increase in the approach rate with respect to changes in the undulation angle is gradual, so the area where the deceleration control based on the approach rate works (the undulation angle range) is wide, and the deceleration state is erratic indefinitely. Then, the speed of work is impaired.

Therefore, according to the present invention, the deceleration control at the time of the boom falling operation is performed in association with the boom hoisting angle.
The purpose of the invention is to provide a control device for a boom-equipped work vehicle that achieves both reduction of stop shock during deceleration control at a large undulation angle and quickness of work during deceleration control at a small undulation angle. Is.

[0006]

In the present invention, as a concrete means for solving such a problem, as shown in FIGS. 1 and 2, a boom 3 mounted on a vehicle 1 so as to be capable of being hoisted and driven.
Boom hoisting angle detection means (70, 1) for detecting the hoisting angle of
4), the boom state detecting means (64, 15) for detecting the actual state of the boom 3 and outputting it as an actual value signal, and the output signal from the boom hoisting angle detecting means (70, 14) The limit performance calculating means 61 for calculating the limit performance of the work vehicle at the boom hoisting angle, the actual value signal from the boom state detecting means (64, 15) and the limit performance value signal from the limit performance calculating means 61. Based on the approach rate calculating means 63 for calculating the approach rate of the actual value signal to the limit performance value signal, and the relation of the work vehicle when the approach rate reaches 100% or more in response to the signal from the approach rate calculating means 63. In the control device for a boom-equipped work vehicle, the control device includes a related operation stop signal output means 65 for outputting a stop signal to the drive means 69 so as to stop the operation at least in the direction of increasing the approach rate. In response to the approach rate signal from the rate calculating means 63, the maximum speed during the fall operation of the boom 3 is set to 100 when the approach rate reaches a predetermined value.
The driving means 69 is designed to reduce the value in the range up to 100% and to make it zero in the vicinity of the approach rate of 100%.
Speed limit signal output means 6 for outputting the maximum speed limit signal to
6 and a speed at which the predetermined value of the approach rate is set to a value closer to the lower approach rate as the boom undulation angle is larger in response to a signal corresponding to the boom undulation angle from the boom undulation angle detection means (70, 14). It is characterized in that it is provided with a restriction start time setting means 67.

[0007]

According to the present invention, when the maximum speed of the boom 3 during the fall motion is limited based on the maximum speed limit signal output from the speed limit signal output means 66, the speed limit start timing setting means 67 controls the deceleration. Since the predetermined value of the approach rate that is the start reference is set to the lower approach rate as the boom hoisting angle is larger, the deceleration control is started from the lower approach rate in the boom hopping operation in the large hoisting angle range. The speed limit area is expanded by this amount to prevent abrupt deceleration. Conversely, when the boom falls in the small hoisting angle area, the speed limit area is reduced by the amount that the deceleration control starts from the high approach rate It is possible to avoid slow work continuation.

[0008]

Therefore, according to the control device for a work vehicle with a boom of the present invention, the start time of the speed limit during the boom laying down operation is set in correspondence with the boom laying down angle, so that the laying down operation from the large hoisting angle is performed. Since a proper speed limit area is ensured in both cases of falling motion from the small up-and-down angle, shock is generated due to rapid deceleration during the down-and-lapping motion from the large up-and-down angle as in the past, or It is possible to prevent the slow work state from being continued during the laying motion from the small up-and-down angle, thereby improving the safety or workability of the work vehicle with a boom, which in turn can contribute to the improvement of its commercial value. Is what you get.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The control device for a boom-equipped work vehicle according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 2 shows a mobile crane Z equipped with the control device according to the embodiment of the present invention. ing. In this mobile crane Z, a telescopic boom 3 is movably mounted on a swivel base 2 mounted on the vehicle 1 so that the boom 3 can be hoisted and driven by a hoisting cylinder 4. Further, outriggers 5 are arranged at four positions on the front, rear, left and right of the vehicle 1. Further, in the figure, reference numeral 6 is an operating lever for up-and-down operation, 7 is a hydraulic unit,
The hydraulic pressure supplied to and discharged from the hydraulic unit 7 achieves the hoisting, turning, and expanding / contracting operations of the boom 3 and the operation of the outrigger 5, respectively.

By the way, in this mobile crane Z,
The boom 3 has a hoisting angle θ =
It is possible to drive up and down between the maximum undulation angle position of 80 ° and the minimum undulation angle position of the undulation angle θ = 0 ° as shown by the chain line. However, when the boom 3 is undulated in this way, work can be carried out accordingly. Since the radius changes, the limit performance of the crane vehicle Z also changes as shown in the limit performance diagram of FIG. 2 (an example in which the boom 3 is undulated while keeping the boom length constant) is shown. As the undulation angle decreases, the limit performance decreases. Therefore, when the actual load state of the mobile crane Z reaches this limit performance during the fall motion of the boom 3, it is necessary to stop the fall motion of the boom 3 further, and in this case, a stop shock is generated. As described above, it is necessary to reduce the operating speed of the laying motion before the limit performance is reached in order to reduce it. Further, in this case, the rate of change of the limit performance with respect to the change of the undulation angle is not constant, and the rate of change is large in the large undulation angle region, and the marginal performance is reached by a slight change of the undulation angle, so that the change of the undulation angle is supported As described above, it is necessary to consider the change in the marginal performance.

Therefore, in the control device of this embodiment, when the deceleration control and the stop control at the time of the fall motion of the boom 3 are performed by the control signal output from the control unit 10 to be described later to the hydraulic unit 7, the above-mentioned respective requirements are required. In order to satisfy both of the above, the present invention is applied and the following control method is adopted.

First of all, the basic idea of the deceleration / stop control in the control system of this embodiment will be explained. In this embodiment, the limit performance and the actual load state are compared, and the degree of approach of the actual value to the limit performance is compared. That is, when calculating the approach rate, both sides calculate this as a moment value, and the actual moment value (actual moment value) against the moment value (allowable moment value) corresponding to the limit performance
Is calculated as the approach rate, and deceleration control and stop control are performed based on this approach rate. Then, when the approach rate of 100% is reached, the fall motion of the boom 3 is forcibly stopped (stop control), and the approach rate of 1
The deceleration control of the fall operation is started from the side of the approach rate lower than 00% by a predetermined amount, and stopped at the approach rate of 100%. The allowable moment value corresponding to the above limit performance is obtained for each controlling factor of the overturning moment such as the boom hoisting angle, the boom length, the turning angle, and the outrigger overhanging width, and is stored as a map value.

Further, in this deceleration control, the approach rate, which is a reference for starting the deceleration control, is changed in accordance with the magnitude of the hoisting angle of the boom 3 and the boom length. That is, in this embodiment, first, the hoisting angle region of the boom 3 is divided into three stages as shown in FIG. 2, and the hoisting angle θ = 70 from the maximum hoisting angle position of the hoisting angle θ = 80 °.
The relief angle range of ° is the first relief angle area, and the relief angle θ = 7.
The undulation angle range of 0 ° to θ = 50 ° is defined as the second undulation angle region,
Furthermore, the undulation angle range from the undulation angle θ = 50 ° to θ = 0 ° to the minimum undulation angle is defined as the third undulation angle region. Furthermore, the extension area of the boom is divided into three areas, a large extension area, a middle extension area, and a small extension area, according to the extension amount. And
Three control patterns A to C as shown in FIGS. 4 to 6 are set corresponding to the respective undulation angle regions and the boom extension region, and these are stored as a map.

The deceleration control of the fall motion of the boom 3 is basically performed by reducing the opening of a flow rate control valve (not shown) in the hydraulic unit 7. Then, among the control patterns A to C, the control pattern A is a control pattern corresponding to the first undulation angle region, and in the large extension region, as shown in the deceleration characteristic diagram L ₁ , the approach ratio is 80% to medium. As shown in the deceleration characteristic chart L _{2 in} the extension area, the approach rate is 85%, and in the small extension area, the deceleration characteristic chart L 2.
_{As shown in 3,} the valve opening is decreased from the approach rate of 90% to start deceleration control. In addition, the control pattern B is a control pattern corresponding to the second undulation angle region. In the large extension region, the approach ratio is 83% as shown in the deceleration characteristic diagram L ₁ , and in the medium extension region as shown in the deceleration characteristic diagram L ₂ . From the approach rate of 87% to the approach rate of 93% as shown in the deceleration characteristic diagram L _{3 in} the small extension range, the valve opening is decreased to start the deceleration control. Further, the control pattern C is a control pattern corresponding to the third undulation angle region, and in the large extension region, the approach ratio is 85% as shown in the deceleration characteristic diagram L ₁ , and in the medium extension region, the deceleration characteristic diagram L.
From approaching 90% as _2, and further from the closure rate of 95% as the deceleration characteristic diagram L ₃ is a small elongated area, so as to initiate the deceleration control to reduce the valve opening, respectively.

As described above, the larger the undulation angle of the boom 3 and the longer the boom length, the deceleration control is started from the low approach ratio side. This is because if the deceleration control is not started from an earlier stage, the deceleration will be abrupt and the shock at stopping will be excessive, as the boom length is longer, the more the inertial force of the lofting is, the faster the stage will be. This is because the shock at the time of stop may be excessive unless the deceleration control is started from.

In order to perform deceleration control and stop control at the time of boom fall operation based on the above control concept, a control unit 10 is provided as shown in FIGS. A signal corresponding to the turning angle of the swivel base 2 from the turning angle sensor 11, a signal corresponding to the overhang length of the outrigger 5 from the outrigger sensor 12, and a signal corresponding to the length of the boom 3 from the boom length sensor 13. The boom swell angle sensor 14
Is a signal corresponding to the hoisting angle of the boom 3, a signal corresponding to the moment load applied to the boom 3 from the moment sensor 15, and a signal corresponding to the operation direction and the operation amount of the operation lever 6 from the operation amount sensor 16. Are input respectively, and the above-mentioned respective controls are performed based on these respective control factors. In this embodiment, the boom length sensor 13, the boom hoisting angle sensor 14, and the moment sensor 15 constitute the boom state detecting means 64 in the claims, and the boom hoisting angle sensor 14 is also included.
Thus, the boom hoisting angle detection means 70 in the claims is constituted.

The specific control is as follows. First, as shown in FIG. 1, the control unit 10 includes a limit performance calculation means 61, an actual value calculation means 62, an approach rate calculation means 63, a related operation stop signal output means 65, a speed limit signal output means 66, and a speed limit start. A timing setting means 67 and a comparison means 68 are provided. Then, the limit performance calculation means 6
1, a turning angle signal, an outrigger extension width signal, and a boom length signal are input, and the limit performance calculating means 61 determines the limit performance under the current boom state from the limit performance map based on these signals. Read as.

The actual value calculating means 62 calculates the current moment value as an actual value based on the moment value signal input from the moment sensor 15. The approach rate calculating means 63 calculates the approach rate based on the allowable moment value output from the limit performance calculating means 61 and the actual moment value output from the actual value calculating means 62.

First, the related operation stop signal output means 6
In 5, when the approach rate signal is received from the approach rate calculation means 63 and the approach rate has already reached 100%,
The drive means 69 (specifically, the hydraulic unit 7 in order to immediately stop various related operations in the direction of further increasing the approach rate, for example, the fall operation and the swing operation of the boom 3).
Output the stop signal to the flow control valve inside) to stop the operation.

On the other hand, the speed limit signal output means 66 receives the approach rate signal from the approach rate calculation means 63 and outputs the maximum speed limit signal when the approach rate reaches a predetermined value. In this case, The predetermined value of the approach rate, which is a reference for starting the maximum speed limit control, is set by the speed limit start timing setting means 67 according to the hoisting angle of the boom 3 and the boom length, that is, the speed limit start timing setting means 67. In response to the undulation angle signal and the boom length signal, the deceleration characteristic corresponding to the continuously changing boom state (Figs. 4 to 6).
Are sequentially selected and output to the speed limit signal output means 66. Therefore, the speed limit signal output means 66 is
A signal corresponding to a predetermined value (map value) selected by the speed limit start timing setting means 67 is output to the comparing means 68 as a speed limit signal.

Further, the comparison means 68 compares the valve opening degree given by the speed limit signal with the valve opening degree corresponding to the operation amount of the operation lever 6 detected by the operation amount sensor 16 to determine the valve opening degree. The smaller signal is selected and output to the drive means 69. When the predetermined approach rate is reached, the operation speed of the fall motion of the boom 3 is limited and gradually reduced to reach the approach rate 100%. It is to stop at a certain point. For example, when the deceleration characteristic diagram L ₁ of the control pattern A is selected and the valve opening corresponding to the operation amount of the operation lever 6 is 50%,
The deceleration control is started not at the approach rate of 80% but at the approach rate of 90% shown by the point a in FIG.

The above control will be described in more detail with reference to the flow chart shown in FIG. 3. First, in step S1, boom hoisting angle θ, boom length L, moment value M, and control valve are set as control factors. Read the manipulated variable a. Next, in step S2, the current limit performance of the mobile crane Z, that is, the allowable moment value M ₀ is calculated (map reading), and in step S3 the allowable moment value M ₀ and the detected moment value (actual moment value) are calculated. The approach rate α (= M / M ₀ ) is calculated from M and.

Next, in step S4, it is judged whether or not the approach rate has already reached 100%. If it has reached 100%, the approach rate α is reached in step S14.
All the related operations in the direction of increasing (eg, the fall operation of the boom 3 or the turning operation in the direction of deteriorating the stability) are stopped.

On the other hand, when it is determined in step S4 that the approach rate α has not reached 100%, it is determined in step S5 whether or not the boom 3 is in the fall operation, and the deceleration control is performed in the non-fall operation. However, if it is determined that the vehicle is in a fallen state, the current load state belongs to the control pattern A, the control pattern B, or the control pattern B in steps S6 and S8. It is determined whether it belongs to the control pattern C.

That is, if it is determined in step S6 that it belongs to the control pattern A, the valve opening degree VA of the control pattern A is set. If it is determined that the control pattern B is set in steps S6 and S8, the control pattern B is set. If the valve opening degree VB of B is further determined to be the control pattern C in step S8, the valve opening degree VC of the control pattern C is read out.

Then, in step S11, the valve opening degree V corresponding to the operation amount of the operating lever 6 is compared with any one of the above valve opening degrees (VA, VB, VC), and the valve opening degree V and each valve opening degree V are compared. Of the valve openings (VA, VB, VC), a valve opening having a smaller value is selected and output (step S
12, S13), after performing predetermined deceleration control, the process is returned.

By repeating the above control, the deceleration control at the time of the hoisting operation of the boom 3 according to the hoisting angle and the operation stop control at the limit performance point are realized, and the rapid deceleration at the time of the hoisting operation at the large hoisting angle is realized. In addition to the above, the slow motion at the time of tilting motion at a small hoisting angle is prevented, proper deceleration and stop are achieved in the entire hoisting angle region, and the shock at the time of stop is suppressed as much as possible. is there.

In this embodiment, the limit performance calculating means 61 reads out the preset limit (map) limit performance corresponding to the current boom state, but the present invention is not limited to this. Instead of this, the limit performance calculating means 61 may calculate the limit performance according to the current boom state.

Similarly, in this embodiment, the approach ratio was obtained as a ratio of moment values, but in other embodiments of the present invention, this is used as another state quantity such as a working radius or a hanging load value. It can also be obtained as the ratio of. For example, in the case of obtaining the ratio of the working radius, as shown by a broken line in FIG. 1, the actual value calculating means 62 also includes a boom length signal from the boom length sensor 13 and a hoisting angle signal from the boom hoisting angle sensor 14. It suffices to input and to calculate the current working radius.

Further, in this embodiment, a predeceleration deceleration characteristic is set as shown in FIGS. 4 to 6, and this is selected by the speed limit start timing setting means 67 to be output to the speed limit signal output means 66. In the other embodiment of the present invention, for example, one basic deceleration characteristic is set (for example, the characteristic diagram L _{1 in} FIG. 4), and this is corresponded to the boom hoisting angle and the like. It may be corrected sequentially and input to the speed limit signal output means 66. In this case, since continuous control can be performed corresponding to changes in the hoisting angle of the boom 3, more accurate deceleration / stop control can be performed. In this embodiment, the control pattern is divided into three and set as described above, but the present invention is not limited to this, and it is needless to say that three or more patterns can be set. In such a case, although it is map control, it is possible to perform control with accuracy close to arithmetic control.

In this embodiment, a crane vehicle with a retractable boom that can rotate is used as an object, but the present invention is not limited to this, and is applicable to other work vehicles with booms such as aerial work vehicles. It is needless to say that it can be widely applied, that it can be applied to a work vehicle with a boom that does not have a swing function, and that it can be applied to a work vehicle that has a boom that does not have a telescopic function.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a control device for a work vehicle with a boom according to an embodiment of the present invention.

FIG. 2 is an overall system diagram of a control device for a boom-equipped work vehicle according to an embodiment of the present invention.

FIG. 3 is a control flowchart of the control device according to the embodiment of the present invention shown in FIG.

FIG. 4 is a speed limit map at a large undulation angle of the control device according to the embodiment of the present invention.

FIG. 5 is a speed limit map when the control device according to the embodiment of the present invention is in a middle undulation angle.

FIG. 6 is a speed limit map at a small undulation angle of the control device according to the embodiment of the present invention.

[Explanation of symbols]

1 is a vehicle, 2 is a swivel base, 3 is a boom, 4 is a hoisting cylinder, 5 is an outrigger, 6 is an operating lever, 7 is a hydraulic unit, 10 is a control unit, 11 is a turning angle sensor, 12 is an outrigger sensor, 13 is a Boom length sensor, 14 boom up and down angle sensor, 15 moment sensor, 16 operation amount sensor, 61 limit performance calculating means, 6
2 is an actual value calculation means, 63 is an approach rate calculation means, 64 is a boom state detection means, 65 is a related operation stop signal output means,
Reference numeral 66 is a speed limit signal output means, 67 is a speed limit start timing setting means, 68 is a comparison means, 69 is a drive means, 70 is a boom hoisting angle detection means, and Z is a mobile crane.

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[Procedure amendment]

[Submission date] April 23, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

On the other hand, the speed limit signal output means 66 receives the approach rate signal from the approach rate calculation means 63 and outputs the maximum speed limit signal when the approach rate reaches a predetermined value. In this case, The predetermined value of the approach rate, which is the reference for starting the maximum speed limit control, is set by the speed limit start timing setting means 67 according to the hoisting angle of the boom 3 and the boom length. That is, the speed limit start timing setting means 67 receives the undulation angle signal and the boom length signal and sequentially selects the deceleration characteristics (FIGS. 4 to 6) corresponding to the continuously changing boom state. The speed limit signal output means 6
Output to 6. Therefore, the speed limit signal output means 66
Outputs a signal corresponding to a predetermined value (map value) selected by the speed limit start timing setting means 67 to the comparison means 68 as a speed limit signal.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (1)

[Claims] 1. A boom hoisting angle detection means (70, 14) for detecting a hoisting angle of a boom (3) mounted on a vehicle (1) so as to be hoisted and driven, and an actual state of the boom (3). Boom state detecting means (64, 15) for detecting and outputting as an actual value signal and output signals from the boom hoisting angle detecting means (70, 14) are received to calculate the limit performance of the work vehicle at the present boom hoisting angle. Limit performance calculating means (61), the limit performance of the actual value signal based on the actual value signal from the boom state detecting means (64, 15) and the limit performance value signal from the limit performance calculating means (61). The approach rate calculating means (63) for calculating the approach rate to the value signal and the approach rate of 1 when receiving the signal from the approach rate calculating means (63).
And a related operation stop signal output means (65) for outputting a stop signal to the drive means (69) so as to stop at least the operation in the direction of increasing the approach rate when the work vehicle reaches more than 00%. A control device for a work vehicle equipped with a boom, wherein the approach rate reaches a predetermined value when the boom (3) receives the approach rate signal from the approach rate calculation means (63) and the boom (3) is in the fall motion. The speed limit signal output means (66) for outputting the maximum speed limit signal to the drive means (69) in order to reduce it within the range from the time point of approach to 100% of the approach rate and to make it zero in the vicinity of the approach rate of 100%. And a speed limit for setting the predetermined value of the approach rate to a value closer to the lower approach rate as the boom undulation angle is larger in response to a signal corresponding to the boom undulation angle from the boom undulation angle detection means (70, 14). Start timing setting means (67) and the boom with work vehicle control device according to claim and further comprising a.