JP3252006B2 - Control device for work vehicle with boom - Google Patents

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 a falling operation of a special boom based on a 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, in order to prevent the crane vehicle from overturning due to an overload operation, for example, when the boom falls down, a predetermined crane is used. Continuously monitor the relative relationship between the vehicle's limit performance (for example, allowable moment value) and the current load state (actual moment value). , A predetermined stop signal is output to immediately stop the operation of the boom in the falling direction.

On the other hand, if the boom suddenly stops when the overload is stopped, it is expected that a dangerous state will be caused by its falling inertia force. Further, 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 control that gradually reduces the operating speed of the boom lowering operation from a state before reaching 0%, for example, at the time of an approach rate of 90%, and gradually stops at the time of an approach rate of 100%, so-called maximum speed limiting control. ing.

[0004]

However, in the conventional maximum speed limit control, the approach rate serving as a reference for speed limitation is set to a constant value (for example, an approach rate of 90%) regardless of the boom angle. Therefore, there was a problem as described below. That is, in a region where the boom undulation angle is large, the rate of change of the working radius with respect to the undulation angle is large, and conversely, in a region where the boom undulation angle is small, this becomes small. For this reason, the change state of the actual moment value, in which the working radius is the main controlling factor, greatly changes according to the boom undulation angle, and in the large undulation angle region, a slight change in the undulation angle causes the actual moment value relative to the limit moment value to change. The approach rate sharply increases, resulting in rapid deceleration, and a relatively large stop shock occurs. On the other hand, in the small undulation angle area, since the increase in the approach rate with respect to the change in the undulation angle is gradual, the area where the deceleration control based on the approach rate works (the undulation angle range) is widened, and the deceleration state in which the lapping is infinite And the speed of operation is impaired.

Accordingly, the present invention provides a deceleration control at the time of the boom lowering operation in relation to the boom raising and lowering angle.
A control device for a boom-equipped work vehicle capable of achieving both a reduction in stop shock at the time of deceleration control at a large undulation angle and a quick operation at the time of deceleration control at a small undulation angle. It is.

[0006]

According to 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 able to be driven up and down freely.
Boom undulation angle detecting means (70,1)
4), a boom state detecting means (64, 15) for detecting an actual state of the boom 3 and outputting it as an actual value signal, and receiving an output signal from the boom undulating angle detecting means (70, 14) to receive a current value. The critical performance calculating means 61 for calculating the critical performance of the work vehicle at the boom hoisting angle, the actual value signal from the boom state detecting means (64, 15) and the critical performance value signal from the critical performance calculating means 61 An approach rate calculating means 63 for calculating an approach rate of the actual value signal to the marginal performance value signal based on the signal from the approach rate calculating means 63; A control device for a boom-equipped working vehicle, comprising: a related operation stop signal output unit 65 that outputs a stop signal to a driving unit 69 to stop at least an operation in a direction to increase the approach rate among the operations. In response to the approach rate signal from the rate calculating means 63, the maximum speed at the time of the boom 3 falling down operation is changed to the approach rate 100 when the approach rate reaches a predetermined value.
% In order to reduce the value in the range up to 100% and reduce it to zero near the approach rate of 100%.
Speed limit signal output means 6 for outputting the maximum speed limit signal to the
6 and a speed for receiving the signal corresponding to the boom undulation angle from the boom undulation angle detection means (70, 14) and setting the predetermined value of the approach rate to a value closer to the lower approach rate as the boom undulation angle is larger. And a restriction start time setting means 67.

[0007]

According to the present invention, when the maximum speed at the time of the tilting operation of the boom 3 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 control. Since the predetermined value of the approach rate serving as the starting reference is set closer to the lower approach rate as the boom hoisting angle is larger, the deceleration control is started from the lower approach rate when the boom falls down in the large hoisting angle region. The speed limit area is expanded by the amount to prevent rapid deceleration, and conversely, when the boom falls down in the small undulation angle area, the speed limit area is reduced by the amount that the deceleration control is started from a high approach rate and the deceleration state The continuation of the slow work in is avoided.

[0008]

Therefore, according to the control device for a working vehicle with a boom of the present invention, the starting operation of the speed limit at the time of the boom tilting operation is set in accordance with the boom hoisting angle, whereby the tilting operation from the large hoisting angle is performed. In any case, the proper speed limit area is secured at the time of the fall operation from the small undulation angle, or the occurrence of the shock due to the sudden deceleration at the time of the fall operation from the large undulation angle as in the related art, or This prevents the continuation of a slow working state during the falling operation from a small undulation angle, which improves the safety or workability of the boom-equipped work vehicle, and can also contribute to the improvement of its commercial value. It is obtained.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 is a perspective view of a control device for a working vehicle with a boom according to the present invention. FIG. 2 shows a crane vehicle Z equipped with a control device according to an embodiment of the present invention. ing. In this crane truck Z, a telescopic boom 3 is mounted on a swivel 2 that is mounted on the vehicle 1 so as to be capable of swinging drive, and the boom 3 is driven up and down by a hoist cylinder 4. Outriggers 5 are arranged at four positions on the front, rear, left and right of the vehicle 1, respectively. Further, in the figure, reference numeral 6 denotes an operation lever for an up / down operation, and 7 denotes a hydraulic unit.
Each operation of raising and lowering, turning, expanding and contracting the boom 3 and the operation of the outrigger 5 are respectively achieved by the hydraulic pressure supplied and discharged from the hydraulic unit 7.

By the way, in this crane truck Z,
The boom 3 has an undulation angle θ = as shown by a solid line in FIG.
The undulation can be driven between the maximum undulation angle position of 80 ° and the minimum undulation angle position of the undulation angle θ = 0 ° as shown by a dashed line. When the boom 3 is undulated in this way, work is performed accordingly. Since the radius changes, the limit performance as the crane truck Z also changes as shown in the limit performance diagram of FIG. 2 (showing an example in which the boom 3 is raised and lowered with the boom length kept constant), The marginal performance decreases as the undulation angle decreases. Therefore, when the actual load state of the crane vehicle Z reaches this limit performance during the falling operation of the boom 3, it is necessary to stop the further falling operation of the boom 3, and in this case, a stop shock is generated. As described above, it is necessary to reduce the operating speed of the lodging operation before the limit performance is reached in order to reduce the speed. Furthermore, in this case, the rate of change of the marginal 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 in the undulation angle. As described above, it is necessary to consider the change in the marginal performance.

Therefore, in the control device of this embodiment, when performing the deceleration control and the stop control at the time of the tilting operation of the boom 3 by the control signal output from the control unit 10 to the hydraulic unit 7 described below, In order to satisfy both, the present invention is applied and the following control method is adopted.

First, the basic concept of deceleration / stop control in the control device of this embodiment will be described. In this embodiment, the limit performance is compared with the actual load condition to determine the degree of approach of the actual value to the limit performance. That is, when calculating the approach rate, both calculate this as a moment value, and the actual moment value (actual moment value) with respect to the moment value (allowable moment value) corresponding to the limit performance
Is calculated as an approach rate, and deceleration control and stop control are performed based on the approach rate. When the approach rate reaches 100%, the boom 3 is forcibly stopped (down control).
The deceleration control of the falling motion is started from the low approach rate side by a predetermined amount than 00%, and stopped at the approach rate of 100%. The permissible moment value corresponding to the limit performance is obtained for each dominant factor of the overturning moment such as the boom hoisting angle, the boom length, the turning angle, the outrigger overhang width, and stored as a map value.

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

Here, the deceleration control of the falling motion of the boom 3 is basically performed by reducing the opening of a flow control valve (not shown) in the hydraulic unit 7. Then, among the control patterns A through C, the control pattern A is a control pattern corresponding to said first derricking angle region, the closure rate of 80% as the deceleration characteristic diagram L ₁ is large elongation zone, medium from approaching 85% as the deceleration characteristic diagram L ₂ is in an extended area, the deceleration characteristic diagram L in yet small elongation zone
_{As shown in 3} , the deceleration control is started by decreasing the valve opening from the approach rate of 90%. Further, the control pattern B is a control pattern corresponding to the second derricking angle region, the closure rate of 83% as the deceleration characteristic diagram L ₁ is large elongation region, as the deceleration characteristic diagram L ₂ is a medium elongation region from approaching 87%, and further from the closure rate of 93% 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. Further, the control pattern C is a control pattern corresponding to the third derricking angle region, the closure rate of 85% as the deceleration characteristic diagram L ₁ is large elongation zone, deceleration characteristic diagram L in the medium elongation region
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 deceleration control is started from the low approach rate side as the boom 3 has a larger hoisting angle and the boom length is longer. If the deceleration control is not started from an earlier stage because the change in the rate is large, a sudden deceleration will occur and the shock when stopping will be excessive. This is because if the deceleration control is not started from, the shock at the time of stopping may be excessive.

In order to perform the deceleration control and the stop control at the time of the boom falling operation based on the control concept as described above, a control unit 10 is provided as shown in FIGS. A signal corresponding to the turning angle of the swivel 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 obtained signal is transmitted to the boom angle sensor 14.
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. , Respectively, and the respective controls are performed based on these control factors. In this embodiment, the boom length sensor 13, the boom angle sensor 14 and the moment sensor 15 constitute a boom state detecting means 64 in the claims.
This constitutes the boom undulation angle detecting means 70 in the claims.

The specific control is as follows. First, as shown in FIG. 1, the control unit 10 includes a limit performance calculation unit 61, an actual value calculation unit 62, an approach ratio calculation unit 63, a related operation stop signal output unit 65, a speed limit signal output unit 66, and a speed limit start. A timing setting means 67 and a comparing means 68 are provided. Then, the limit performance calculating means 6
1, a turning angle signal, an outrigger overhang width signal, and a boom length signal are input, and the limit performance calculating means 61 calculates 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 a 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.

Here, first, the related operation stop signal output means 6
In step 5, when the approach rate signal is received from the approach rate calculation means 63 and the approach rate has already reached 100%,
The driving means 69 (specifically, the hydraulic unit 7) for immediately stopping various related operations in the direction for further increasing the approach rate, for example, the falling operation and the turning operation of the boom 3.
The operation is stopped by outputting a stop signal to the flow control valve inside the control valve.

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 a maximum speed limit signal when the approach rate reaches a predetermined value. The predetermined value of the approach rate as a reference for starting the maximum speed limit control is set by the speed limit start time setting means 67 in accordance with the up-and-down angle of the boom 3 and the boom length. That is, the speed limit start timing setting means 67 receives the hoisting 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
6 is output. Therefore, the speed limit signal output means 66
Outputs a signal corresponding to a predetermined value (map value) selected by the speed limit start time setting means 67 to the comparing means 68 as a speed limit signal.

Further, the comparing means 68 compares the valve opening provided by the speed limit signal with the valve opening corresponding to the operation amount of the operation lever 6 detected by the operation amount sensor 16, and determines that the valve opening is The smaller signal is selected and output to the driving means 69, and when the predetermined approach rate is reached, the operating speed of the boom 3 is lowered and gradually reduced to reach the approach rate 100%. It stops at the point. For example, in a case where the deceleration characteristic diagram L ₁ of the control pattern A is selected, when the valve opening degree corresponding to the operation amount of the operating lever 6 is 50%,
The deceleration control is started not from the approach rate 80% but from the approach rate 90% indicated by a point a in FIG.

The above control will be described in more detail with reference to a flowchart shown in FIG. 3. First, in step S1, the control factors are a boom undulation angle θ, a boom length L, a moment value M, a control valve. The operation amount a and the like are read. Next, in step S2, the current limit performance of the crane car Z, i.e., calculates the permissible moment value M ₀ (map reading), the allowable moment value M ₀ and the detected moment value in step S3 (the actual moment value) From M, the approach rate α (= M / M ₀ ) is calculated.

Next, in step S4, it is determined whether or not the approach rate has already reached 100%. If the approach rate has reached 100%, the approach rate α is determined in step S14.
(For example, the boom 3 is tilted down or turned in a direction that degrades stability) in all directions.

On the other hand, if it is determined in step S4 that the approach rate α has not yet reached 100%, it is determined in step S5 whether or not the boom 3 is in the downturn operation. However, if it is determined that the vehicle is lying down, it is determined in step S6 or step S8 whether the current load state belongs to the control pattern A, the control pattern B, or It is determined whether the pattern belongs to the control pattern C.

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

In step S11, the valve opening V corresponding to the operation amount of the operation lever 6 is compared with one of the above-mentioned valve openings (VA, VB, VC). From among the valve openings (VA, VB, VC), a smaller value is selected and outputted (step S
12, S13), after performing the predetermined deceleration control, return.

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

In this embodiment, the limit performance calculating means 61 reads out the limit performance set (mapped) in advance in accordance with the current boom state. However, the present invention is not limited to this. Instead, for example, the marginal performance calculating means 61 may calculate the marginal performance according to the current boom state.

Similarly, in this embodiment, the approach rate is obtained as a ratio of the moment value. However, in another embodiment of the present invention, the approach rate is calculated as another state quantity such as a working radius or a hanging load value. Can also be obtained as the ratio of For example, when the ratio is calculated as the ratio of the working radius, as shown by a broken line in FIG. Is input, and the current work radius may be obtained by calculation.

Further, in this embodiment, the deceleration characteristics are set in advance as shown in FIGS. 4 to 6, and this is selected by the speed limit start timing setting means 67 and sent to the speed limit signal output means 66. Although output is performed, in another embodiment of the present invention, for example, one basic deceleration characteristic is set (for example, a characteristic diagram L _{1 in} FIG. 4), and this is corresponded to the boom undulation angle and the like. Then, the data may be sequentially corrected and input to the speed limit signal output means 66. In such a case, continuous control can be performed in response to a change in the up-and-down angle of the boom 3, so that more accurate deceleration / stop control can be performed. In this embodiment, the control patterns are divided into three 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 this case, the control can be performed with an accuracy close to that of the arithmetic control, even though the map control is performed.

In this embodiment, a swivelable crane vehicle with a telescopic boom is used. However, the present invention is not limited to this. Of course, the present invention can be applied to a work vehicle with a boom that does not have a turning function, and can also be applied to a work vehicle that has a boom without a telescopic function.

[Brief description of the 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 working vehicle with a boom according to an embodiment of the present invention.

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

FIG. 4 is a speed limit map at the time of 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 has a middle undulation angle.

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

[Explanation of symbols]

1 is a vehicle, 2 is a turntable, 3 is a boom, 4 is an up / down cylinder, 5 is an outrigger, 6 is an operation lever, 7 is a hydraulic unit, 10 is a control unit, 11 is a turning angle sensor, 12 is an outrigger sensor, and 13 is an outrigger sensor. Boom length sensor, 14 is a boom angle sensor, 15 is a moment sensor, 16 is an operation amount sensor, 61 is a 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,
66 is speed limit signal output means, 67 is speed limit start time setting means, 68 is comparison means, 69 is drive means, 70 is boom undulation angle detection means, and Z is a crane truck.

Claims (1)

(57) [Claims] 1. A boom hoisting angle detecting means (70, 14) for detecting an hoisting angle of a boom (3) mounted on a vehicle (1) so as to be capable of driving up and down, and an actual state of the boom (3). Boom state detecting means (64, 15) for detecting and outputting as an actual value signal; and receiving the output signal from the boom hoisting angle detecting means (70, 14), calculating the limit performance of the work vehicle at the current boom hoisting angle. Limit performance calculating means (61), and a limit performance of the actual value signal based on the actual value signal from the boom state detection means (64, 15) and the limit performance value signal from the limit performance calculation means (61). An approach rate calculating means (63) for calculating an approach rate to the value signal; and an approach rate of 1 upon receiving a signal from the approach rate calculating means (63).
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 of the work vehicle in the direction of increasing the approach rate when the work vehicle reaches 00% or more. A control device for a work vehicle equipped with a boom, comprising: receiving an approach rate signal from the approach rate calculation means (63), and increasing the maximum speed of the boom (3) when the boom (3) is in a downturn operation, wherein the approach rate reaches a predetermined value. Speed limiting signal output means (66) for outputting a maximum speed limiting signal to the driving means (69) in order to reduce the value in the range from the time when the approaching rate reaches 100% to zero near the approaching rate of 100%. A speed limit for receiving a signal corresponding to the boom angle from the boom angle detection means (70, 14) and setting the predetermined value of the approach rate to a value closer to the lower approach rate as the boom angle is larger. Start timing setting means (67) and the boom with work vehicle control device according to claim and further comprising a.