JPH1089306A - Limiting device for working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a operable and safety limiting device by arranging an oil amount limitation release means which gradually releases oil amount limitation by means of an oil amount limiting device when a total required oil amount is not more than a supply oil amount. SOLUTION: An oil amount limitation release means 27 is arranged on the way from an oil amount limitation determination means 23 to oil amount limiting devices 24, 25, 26, while receiving output signals from a supply oil amount calculation means 21 and a total oil amount calculation means 22. Oil amount limitation is carried out with a ratio of a supply oil amount and a total required oil amount, when the total required oil amount exceeds the supply oil amount by the operation of a plurality of levers. In the case that the levers except one are returned to original positions, the hydraulic actuator under operation is gradually released from the limited state. Abrupt fluctuation of the speed is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work machine limiting device for supplying a supply oil from a hydraulic source to a plurality of hydraulic actuators to drive the work machine.

[0002]

2. Description of the Related Art A conventional work machine of this type will be described below with reference to an aerial work vehicle A shown in FIG. Aerial work vehicle A
In FIG. 1, a swivel 2 is disposed on a vehicle 1 so as to be freely rotatable, an extendable boom 3 is provided on the swivel 2 so as to be able to move up and down, and a worktable 4 is provided at a distal end of the extendable boom 3. The turntable 2 can be turned by a turn drive device disposed between the vehicle 1 and the turntable 2. The turn drive device is provided with a turn motor 5, and turns by driving the turn motor 5. ing. An undulating cylinder 6 is arranged between the telescopic boom 3 and the swivel base 2 so that the telescopic boom 3 can be raised and lowered with respect to the vehicle 1. The telescopic boom 3 is composed of a multi-stage boom including a base boom 7, an intermediate boom 8, and a front boom 9,
An extendable cylinder 11 is arranged at least between the base boom 7 and the intermediate boom 8 so that the intermediate boom 8 is driven to extend and retract with respect to the base boom 7. The front boom 9 is provided with a suitable telescopic drive device (a simultaneous telescopic device or the like that is driven to expand and contract in conjunction with the expansion and contraction movement of the intermediate boom 8 with respect to the base boom 7 and is not shown) with respect to the intermediate boom 8. . Here, the turning motor 5, the up-and-down cylinder 6, and the telescopic cylinder 7 correspond to the hydraulic actuator according to claim 1 of the claims.

[0003] In such an aerial work vehicle A, each of the hydraulic actuators can be driven by operating an operating device B provided on the work table 4. As shown in FIG. 3, the operating device B includes a turning operation output unit 12 that outputs a turning operation signal a by operating a turning operation lever 11.
And an up / down operation output unit 14 that outputs an up / down operation signal b by operating the up / down operation lever 13 and an expansion / contraction operation output unit 16 that outputs an expansion / contraction operation signal c by operating the expansion / contraction operation lever 15. .

A turning operation signal a, an up / down operation signal b, and a telescopic operation signal c are transmitted to control devices 17, 18, and 19, respectively. The control devices 17, 18, and 19 are constituted by electromagnetic proportional control valves, and the operation direction and the operation amount are controlled by the operation signals a, b,
c. Then, oil from the hydraulic pressure source 20 is supplied to the turning motor 5, the up-and-down cylinder 6, and the telescopic cylinder 7 via the control devices 17, 18, and 19.

That is, the aerial work vehicle A controls the control device 17 based on operation signals from operation devices B (turning operation lever 11, undulating operation lever 13, and telescopic operation lever 15) provided on the work table 4. The swing motor 5 via
The undulating cylinder 6 and the telescopic cylinder 7 are driven.

Incidentally, each of the operating levers 11, 13, 15
Is operated alone to drive the swing motor 5, the up-and-down cylinder 6, and the telescopic cylinder 7 independently, the amount of oil supplied from the hydraulic power source 20 is smaller than the required amount of oil required to drive each hydraulic actuator independently. Therefore, the drive speed of each hydraulic actuator is determined based on the operation amount of the operation lever. However, when a plurality of operation levers are operated, the total required oil amount is supplied in the relationship between the total required oil amount of the required oil amount required for each operation associated with the plurality of operations and the supply oil amount supplied from the hydraulic power source 20. When the amount of oil exceeds the oil amount, there is a problem that only the hydraulic actuator with a small load on the operation is driven and the hydraulic actuator with a large load is not driven. It was equipped.

That is, as shown in FIG. 3, a conventional working machine restriction device C comprises a supply oil amount calculation means 21, a total required oil amount calculation means 22, a flow rate restriction determination means 23, and an oil amount restriction device 24. , 25, 26. The supply oil amount calculation means 21 calculates the supply oil amount of the hydraulic power source 20 as follows. The hydraulic power source 20 is supplied from a hydraulic pump driven by a traveling engine of the aerial work vehicle A, and the supplied oil amount Qa is calculated by calculation if the pump capacity and the engine speed are known. can do. If the hydraulic pump of the hydraulic power source 20 is a constant displacement pump that also rotates the engine rotation at a constant speed, the supply oil amount Qa is determined in advance, but if the hydraulic pump is a variable displacement pump that also varies the engine rotation, Using the hydraulic pump discharge displacement detector and the engine rotation detector, the supply oil amount Qa can be obtained based on the detection values from both detectors.

The total required oil amount calculating means 22 calculates the total required oil amount Qb required by the operating device B when each of the operation levers is operated.
The sum of c can be calculated as the total required oil amount Qb. The flow rate limit determining means 23 is provided with the supplied oil amount calculating means 2.
1 and the total required oil amount calculating means 22
Compare the total required oil amount Qb calculated in
When b is equal to or less than the supply oil amount Qa, a predetermined oil amount restriction signal is output (a signal based on the restriction ratio K = 1 is output), and
When the total required oil amount Qb is equal to or greater than the supplied oil amount Qa, the ratio of the supplied oil amount Qa to the total required oil amount Qb (oil amount restriction ratio K = Qa
/ Qb) is output.

The oil amount limiting devices 24, 25, and 26 are respectively provided on paths on the way of transmitting the operation signals a, b, and c to the control devices 17, 18, and 19. When receiving the amount limiting signal, the operation signals a, b and c are changed to a based on the oil amount limiting ratio (K = Qa / Qb).
.Times.Qa / Qb, b.times.Qa/Qb, and c.times.Qa/Qb to be transmitted to the control devices 17, 18, and 19. When (K = 1), the operation signals a, b, and c are transmitted directly to the control devices 17, 18, and 19.

As described above, in the conventional limiter for a working machine having the limiter C, when a plurality of operation levers are operated, the total required oil amount Qb associated with the plurality of operations and the supply oil amount supplied from the hydraulic pressure source 20 are determined. In relation to Qa, the total required oil quantity Q
When b exceeds the supply oil amount Qa, the flow amount restriction determination means 23 limits the oil amount at the ratio of the supply oil amount Qa to the total required oil amount Qb.
Only the operation signal within the range that can be operated with the supply oil amount Qa is output to the control devices 17, 18, and 19 even if the operation exceeds the a. The problem that the hydraulic actuator having a large value does not drive can be prevented from occurring.

[0011]

However, the conventional limiter for a working machine provided with the limiter C has the following problems. That is, by operating a plurality of operation levers, the total required oil amount Qb exceeds the supply oil amount Qa and the supply oil amount Qa
When the oil amount is restricted at the ratio of the total required oil amount Qb and one of the plurality of operation levers is left, the operation lever is returned to its original state and the operation is performed. The hydraulic actuator as it is is no longer limited from the state in which the amount of oil has been limited, and drives at an abrupt increase in speed.

This can be understood, for example, from the graph shown in FIG. First, before starting the description of FIG. 4, it will be explained that the operation of the hydraulic actuator with respect to the normal operation lever is slightly delayed. That is, when each hydraulic actuator is started by each operation lever, it is slowly started, and when it is stopped, it is slowly stopped. Then, the normal slow start time is set to T1, and the slow stop time is set to T2, so that T1> T2. The reason is that the telescopic boom 3 may be gradually raised at the time of the slow start, but may be gradually stopped at the time of the stop, and the telescopic boom 3 may be moved from the position of the telescopic boom 3 at the time of the stop operation (return of the operation lever to the neutral position).
The movement amount (flow amount) to the stop position of
Since the stop is performed at a stop position opposite to the stop position assumed by the operator, the slow stop time is set shorter than at the time of slow start.

The operation lever having the functions of such a slow start and a slow stop includes an up / down operation lever 13 and a telescopic operation lever 15.
FIG. 4 shows an example in the case of performing the operation according to. In FIG. 4, when the raising and lowering operation lever 13 is operated alone, the speed is accelerated for a time T1 until the speed reaches the speed V1, and thereafter the telescopic boom 3 is raised and lowered at the speed V1. When a plurality of operations are performed by operating the telescopic operation lever 15 while performing the undulating operation alone, the total required oil amount Qb exceeds the supplied oil amount Qa, and the oil amount is determined by the ratio of the supplied oil amount Qa to the total required oil amount Qb. Restriction is performed, the undulating speed is reduced to V2, and the telescopic boom 3 is undulated at the speed V2 during a plurality of operations thereafter. Next, when the telescopic operation lever 15 is returned to the original operation and the undulation operation lever 13 is operated alone, the restriction on the oil amount is released, and the undulation speed is accelerated to V1 in time T2. That is, when the telescopic operation lever 15 is set to T2
, The telescopic boom 3 comes up and down in the time T2. At this time, from the relationship of T1> T2, it can be understood from FIG. 4 that the acceleration after the release of the oil amount limitation is greater than the acceleration by the normal up / down operation lever 13.

That is, when a plurality of combined operations are performed from a single operation, the speed is gradually reduced from V1 to V2. However, when a single operation is performed from a plurality of combined operations, the speed rapidly increases from V2 to V1. The problem was safety and safety. Therefore, when performing an independent operation from a plurality of combined operations, it is necessary for the operator to pay attention to perform the independent operation once to neutralize all operations (returning the operation) so that the above-described state does not occur. However, the provision of the limiting device C rather causes the operability to deteriorate. Further, an operator who was on the work table due to a sudden change in the operation speed may drop off in some cases, resulting in lack of safety. An object of the present invention is to provide a working machine restriction device that solves the above problems.

[0015]

In order to achieve the above object, an invention according to claim 1 is directed to a working machine which supplies a supply oil from a hydraulic source to a plurality of hydraulic actuators to drive the working machine. Limiting devices, each control device arranged to correspond to each hydraulic actuator to drive and control a plurality of hydraulic actuators, an operating device for outputting an operation signal to each control device, and a supply for each hydraulic actuator A total required oil amount calculating means for calculating the total amount of oil supplied from each control device to each hydraulic actuator based on the operation of the operating device as a total required oil amount; A supply oil amount calculation means for calculating the supply oil amount of the hydraulic pressure source, and comparing the total required oil amount with the supply oil amount, and when the total required oil amount is equal to or less than the supply oil amount, the hydraulic amount limiting device controls When the total required oil amount is equal to or greater than the supply oil amount, the supply amount of oil to each hydraulic actuator is controlled by the oil amount restriction device at a ratio of the supply oil amount to the total required oil amount. In a working machine limiting device configured by an oil amount limiting determining unit that outputs an oil amount limiting signal to the oil amount limiting device so as to limit the amount, the supply oil amount is changed from a state where the total required oil amount is equal to or more than the supply oil amount. An oil amount restriction release means for gradually releasing the oil amount restriction by the oil amount restriction device when the following condition is reached is provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.
This will be described with reference to FIG. In describing the working machine restriction device according to the embodiment of the present invention, a case where the present invention is applied to the aerial work vehicle A described in the related art will be described below. Therefore, reference numerals 1-2 described in the prior art
6, reference numerals a, b, c, and reference numerals A, V1, V2, T1 are the same as those described in the related art, so that detailed description is omitted in the following description using the same reference numerals.

In FIG. 1, reference numeral D denotes a restricting device used in a working machine restricting device according to an embodiment of the present invention. Is added, and the other parts are the same as those used in the conventional restriction device C.

Numeral 27 denotes a flow rate restriction canceling means, which is provided on the way from the oil quantity restriction determining means 23 to the oil quantity limiting devices 24, 25 and 26, and which is provided with the supply oil quantity calculating means 21 and the total required oil quantity. It is arranged to receive an output signal from the calculating means 22. The output signals from the supplied oil amount calculating means 21 and the total required oil amount calculating means 22 are received, and the total required oil amount Qb is equal to or larger than the supplied oil amount Qa.
It is determined that the state is equal to or less than a, and when such a state is reached, the oil amount restriction signal output from the oil amount restriction determination means 23 is not released immediately but gradually released over time and the oil amount restriction signal is released. A delay device is built in for transmission to the devices 24, 25, 26. Here, the release of the oil amount limit signal is generally set to be performed at T3 which is the same as or longer than the slow start time T1 of the operation.

In the working device restricting device according to the embodiment of the present invention having the above-described configuration, the flow rate restriction canceling means 27 is disposed in the restricting device D. When the oil amount Qb exceeds the supply oil amount Qa and the oil amount is restricted by the ratio of the supply oil amount Qa to the total required oil amount Qb, the operation after leaving any one of the plurality of operation levers Even when the lever is returned to its original position, the hydraulic actuator that is being operated is gradually released from the restriction in which the oil amount was restricted, so that a sudden change in speed can be prevented.

This can be understood, for example, from the graph shown in FIG. 4 by performing a plurality of operations of expansion / contraction and undulation, and the total required oil amount Qb exceeds the supplied oil amount Qa and the supplied oil amount Qa and the total required oil amount Qb When the telescopic operation lever 15 is returned to its original position while the telescopic boom 3 is undulating at the speed V2 while a plurality of operations are being performed, the oil amount restriction is gradually released. The undulation speed is accelerated to V1 in the time of T3. At this time, from the relationship of T1 ≦ T3, it can be understood from FIG. 4 that the acceleration after the release of the oil amount limitation is smaller than or equal to the acceleration by the normal up / down operation lever 13.

In the working machine limiting device according to the embodiment of the present invention, which is constructed and operates as described above, when the operator performs a single operation from a plurality of combined operations, the operator neutralizes all the operations once and then performs the single operation. It is possible to eliminate the need for careful operation and to provide a limiting device with better operability as compared with the conventional case. In addition, it is possible to provide a safe working machine without an operator who has been on the work table due to a sudden change in the operation speed, sometimes falling off.

In the above embodiment, the case where the expansion / contraction operation is stopped while performing a plurality of operations of expansion / contraction and undulations has been described. . Further, the present invention is not limited to the case where a single operation is performed from a plurality of operations,
Even when the operation is performed in a plurality of operations, the operation may be performed when the total required oil amount in the plurality of operations exceeds the supply oil amount to a plurality of operations in a state not exceeding the supply oil amount. Of course, the invention can be implemented in such a case.

Next, the operating device B in the above-described embodiment comprises a turning operation output means 12 for outputting a turning operation signal a by operating the turning operation lever 11 and an up / down operation by operating the up / down operation lever 13. A description will be given of a case in which an up / down operation output unit 14 that outputs an operation signal b and an expansion / contraction operation output unit 16 that outputs an expansion / contraction operation signal c by operating an expansion / contraction operation lever 15 and each operation lever is operated alone or in combination. However, the present invention can also be implemented in a case where the combined operation is automatically performed as another embodiment.

For example, when the workbench 4 of the aerial work platform A is moved horizontally or vertically, the telescopic operation and the undulating operation can be automatically performed only by instructing the operation direction and operation amount by one operation lever. Is already known so that it can be moved horizontally or vertically. Also in this case, since the combined operation is performed, the flow rate restriction described above is performed. The above-described problem similarly occurs when the horizontal operation or the vertical movement control is changed to the single operation. In this case, the present invention is applicable.
It is a matter of course that the operating device can be applied to a case where an operation signal is automatically output in addition to a case where an operation signal is output from the plurality of operation levers.

In the above-described embodiment, the limiting device D is shown in the form of a block diagram, and has been described using each device or means.
In another embodiment, each of these devices or means is C
It is needless to say that the control is carried out by the program control by the PU.

Further, in the above embodiment, the oil amount limiting device 2
4, 25, 26 from the operating device B to the respective control devices 17, 1
Although it has been described that the amount of oil is limited by controlling the operation signals a, b, and c output to 8, 8 and 19, each of the control devices 17, 18, and 19 and the hydraulic actuator 5, 6 and 7 respectively, and from each of the control devices 17, 18, and 19, each hydraulic actuator 5, 6,
The amount of oil supplied to 7 may be limited.

Next, in the above embodiment, the case where the limiting device of the present invention is applied to an aerial work vehicle has been described.
Similarly, as other embodiments, a crane truck, a digging pole truck,
It is needless to say that the present invention can also be applied to such a working machine.

[0028]

According to the working machine limiting device of the present invention which is constructed and operates as described above, the operator can change from a plurality of combined operations to a single operation (or a combined operation with a reduced number of operations).
It is possible to eliminate the necessity of paying attention to performing a single operation (or a combined operation with a reduced number of operations) after neutralizing all operations once. Therefore, it is possible to provide a safe limiting device with good operability as compared with the conventional case.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a limiting device for a working machine according to the present invention.

FIG. 2 is an explanatory diagram illustrating an aerial work vehicle.

FIG. 3 is an explanatory diagram illustrating a conventional work machine restriction device.

FIG. 4 is a graph showing the relationship between the undulation acceleration when the undulation operation is operated alone and the undulation acceleration when the undulation operation is operated in combination.

[Explanation of symbols]

 5, 6, 7 Hydraulic actuator 17, 18, 19 Control device 20 Hydraulic power source 21 Supply oil amount calculation means 22 Total required oil amount calculation means 23 Oil amount restriction determination means 24, 25, 26 Oil amount restriction device 27 Oil amount restriction release Means B Operating device D Limiting device Qa Supply oil amount Qb Total required oil amount

Claims (1)

[Claims] A work machine limiting device for supplying a supply oil from a hydraulic source to a plurality of hydraulic actuators to drive the work machine, wherein each hydraulic actuator is used to drive and control the plurality of hydraulic actuators. Control devices arranged in accordance with the above, an operation device for outputting an operation signal to each control device, an oil amount limiting device for limiting the amount of oil supplied to each hydraulic actuator, and an operation device for operating the operation device. A total required oil amount calculating means for calculating the total amount of oil supplied from each control device to each hydraulic actuator as a total required oil amount, a supplied oil amount calculating means for calculating the supplied oil amount of the hydraulic power source, and a total The required oil amount and the supplied oil amount are compared, and when the total required oil amount is equal to or less than the supplied oil amount, the amount of supplied oil to each hydraulic actuator is not limited by the oil amount limiting device, and the total required oil amount is set. Is greater than or equal to the supplied oil amount, the oil amount limiting device outputs an oil amount limiting signal to the oil amount limiting device so as to limit the oil amount supplied to each hydraulic actuator by the ratio of the supplied oil amount to the total required oil amount. In the working machine limiting device constituted by the oil amount limitation determining means, the oil amount limitation by the oil amount limiting device is gradually reduced when the total required oil amount changes from a state equal to or more than the supply oil amount to a state equal to or less than the supply oil amount. A restriction device for a working machine, characterized in that an oil amount restriction releasing means for releasing is disposed.