JP2002005108A - Limiting device for work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a limiting device of a work machine for preventing the deterioration of control accuracy of limiting control by a shortage of a supply oil quantity according to the degradation by a secular change in a hydraulic power source and reduction in efficiency for driving respective hydraulic actuators by the limiting control in the ratio of the supply oil quantity from the hydraulic power source to the total required oil quantity of oil quantities required by the respective hydraulic actuators in response to operation signals of the respective hydraulic actuators when jointly operating the plural hydraulic actuators. SOLUTION: This limiting device of the work machine is characterized by having an actuator detector E for detecting actuating positions of the respective hydraulic actuators, follow-up delay discriminating means 33, 34 and 35 for outputting a correction command signal of the supply oil quantiry when discriminated as being not operated in a follow-up state by discriminating whether or not the hydraulic actuators are operated in a follow-up state by following an operation signal by receiving a signal from the detector and the operation signal and an oil quantity correcting means 36 for correcting the supply oil quantity from the hydraulic power source by receiving the correction command signal.

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 swivel base 2. The telescopic boom 3 is composed of a multi-stage boom in which a base boom 7, an intermediate boom 8 and a leading boom 9 are sequentially inserted. An extendable cylinder 10 is arranged between at least the base boom 7 and the intermediate boom 8, and Thus, the intermediate boom 8 is driven to expand and contract. 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 10 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. 5, the operating device B is operated by operating a turning operation lever 11 to output a turning operation direction and a turning operation speed signal a, and by operating an up / down operation lever 13 to raise / lower. It comprises an up / down operation output means 14 for outputting an operation direction and an up / down operation speed signal b, and an expansion / contraction operation output means 16 for outputting an expansion / contraction operation direction and an expansion / contraction operation speed signal c by operating an expansion / contraction operation lever 15.

The respective operation direction signal, turning operation speed signal a, undulating operation speed signal b, and telescopic operation speed 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 determined by the operation direction signal and the operation speed signals a, b, and c. The oil from the hydraulic pressure source 20 is supplied to the turning motor 5, the undulating cylinder 6, the telescopic cylinder 1
0 is supplied via control devices 17, 18, and 19.

That is, the aerial work vehicle A is operated based on operation directions and operation speed signals from operation devices B (turn operation lever 11, up-and-down operation lever 13, and telescopic operation lever 15) provided on the work table 4. The swing motor 5, the up-and-down cylinder 6, and the telescopic cylinder 10 are driven via the control devices 17, 18, and 19.

Incidentally, each of the operating levers 11, 13, 15
Is operated alone to drive the swing motor 5, the up / down cylinder 6, and the telescopic cylinder 10 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 oil amount is exceeded, there is a problem that only the hydraulic actuator with a small load on the hydraulic actuator for operation is driven and the hydraulic actuator with a large load is not driven,
To cope with this, the following limiting device C is provided.

That is, as shown in FIG. 5, a conventional limiter C for a working machine includes a supply oil amount calculation means 21, a total required oil amount calculation means 22, an oil amount restriction determination means 23, and an oil amount restriction device. 24, 25, and 26 are provided. 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 20b driven by a traveling engine 20a of an aerial work vehicle A, and the supplied oil amount Qa is determined if the hydraulic pump capacity and the engine speed are known. It can be calculated by calculation. If the hydraulic pump 20b of the hydraulic power source 20 is a constant displacement hydraulic pump that also rotates the engine at a constant speed, the supply oil amount Qa is determined in advance, but the hydraulic pump 20b is a variable displacement hydraulic pump that also varies the engine rotation. Then, the oil supply amount Qa can be obtained based on the detection values from both the hydraulic pump discharge capacity detector and the engine rotation detector.

The hydraulic source 20 shown in FIG. 5 rotates the engine 20a of the traveling engine 20a at a constant speed. The hydraulic pump 20b is a variable displacement hydraulic pump. I have decided. Therefore, the supply oil amount calculating means 21
When the signal from c is received, the supply oil amount Qa can be calculated.

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 b and c can be calculated as the total required oil amount Qb. The oil amount restriction determining unit 23 compares the supplied oil amount Qa calculated by the supplied oil amount calculating unit 21 with the total required oil amount Qb calculated by the total required oil amount calculating unit 22, and determines the total required oil amount Qb as the supplied oil amount. When it is equal to or less than Qa, a predetermined oil amount limiting signal is output (a signal based on the limiting ratio K = 1 is output). When the total required oil amount Qb is equal to or more than the supplied oil amount Qa, the supplied oil amount Qa and the total required oil amount are output. An oil amount restriction signal based on the ratio of Qb (oil amount restriction ratio K = Qa / Qb) is output.

The oil amount limiting devices 24, 25, and 26 are respectively interposed on paths on the way of transmitting the operation speed signals a, b, and c to the control devices 17, 18, and 19. When the operation speed signals a, b, and b are received based on the oil amount restriction ratio (K = Qa / Qb)
c is a × Qa / Qb, b × Qa / Qb, c × Qa / Qb
To be transmitted to the control devices 17, 18, and 19. When the oil amount restriction ratio signal from the oil amount restriction determination means 23 is a predetermined value (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 amount of oil supplied from the hydraulic source 20 are increased. In relation to Qa, the total required oil quantity Q
When b exceeds the supplied oil amount Qa, the oil amount is limited by the ratio of the supplied oil amount Qa to the total required oil amount Qb from the oil amount restriction determining means 23.
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.

[0012]

However, the conventional limiter for a working machine provided with the limiter C has the following problems. That is, with the deterioration and efficiency of the hydraulic pump 20b and the traveling engine 20a due to aging, the discharge capacity becomes insufficient or a predetermined engine speed cannot be obtained, resulting in a shortage of the supplied oil amount Qa.
In some cases, the control accuracy of the limiting device C deteriorates, and the operation of the work machine becomes defective.

That is, despite the provision of the limiting device C, the hydraulic pump 20b and the traveling engine 20
When a plurality of operation levers are operated due to a shortage of the supply oil amount Qa due to deterioration and efficiency decrease due to aging of a, the total required oil amount Qb of the required oil amount required for each operation accompanying the plurality of operations and the hydraulic pressure Oil supply Qa supplied from the source 20
When the total required oil amount Qb exceeds the supply oil amount Qa, the operation of the hydraulic actuator with a small load on the operation of the hydraulic actuator is not abnormal, but the drive of the hydraulic actuator with a large load is slightly delayed. Therefore, it is necessary to take measures such as increasing the operation amount of the operation lever corresponding to the hydraulic actuator and changing the operation ratio of the operation lever in a plurality of normal operations.

In particular, in the embodiment shown and described in FIG. 5, a case where a plurality of operations are performed manually is described. However, when a plurality of operations are performed automatically (for example, when the work table 4 is moved horizontally or vertically). When a horizontal or vertical operation lever disposed on the work table 4 is operated, a signal from the operation lever automatically outputs a signal to a plurality of hydraulic actuators. Although the signal is output in consideration of the above relationship), the signal is automatically output to each hydraulic actuator. Unlike in the case of the operation, it was not possible to take effective measures even if a function for automatically performing a plurality of operations was provided after the corresponding action could not be performed.

It is an object of the present invention to provide a work implement limiting device which solves the above-mentioned problems.

[0016]

According to a first aspect of the present invention, there is provided a limiter for a working machine, wherein a supply oil from a hydraulic source is supplied to a plurality of hydraulic actuators to drive the working machine. A control device for controlling a plurality of hydraulic actuators, the control devices being arranged corresponding to the respective hydraulic actuators, an operating device for outputting an operation signal to each of the control devices, Each oil amount limiting device that limits the amount of oil supplied to each actuator, and a total required oil amount calculation unit that calculates the total of the oil amounts required by each hydraulic actuator based on the operation of the operating device as a total required oil amount, The oil supply amount calculating means for calculating the oil supply amount of the hydraulic pressure source, and when the total required oil amount is equal to or more than the supplied oil amount, each hydraulic activator is operated by the oil amount limiting device at a ratio of the supplied oil amount to the total required oil amount. In a working machine limiting device constituted by an oil amount limiting determining means for outputting an oil amount limiting signal to the oil amount limiting device so as to limit the amount of oil supplied to the eta, each hydraulic actuator is disposed in correspondence with each hydraulic actuator. An actuator detector for detecting the operating position of the
In response to the signal from the detector and the operation signal, the control unit follows the operation signal to determine whether the hydraulic actuator is operating in accordance with the operation signal. A tracking delay determining unit that outputs a command signal; and an oil amount correcting unit that receives the correction command signal and corrects an oil supply amount from a hydraulic power source or an oil supply amount calculated by the oil supply amount calculating unit. It is characterized by the following.

According to a second aspect of the present invention, there is provided a working machine limiting device having a function of outputting a regulation signal to the following delay determining means of the working machine limiting device when a following delay that is longer than a predetermined value is determined. And a regulating means for regulating the operation of the control device in response to the request.

[0018]

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, symbols 20a, 20b, 20c, symbols a, b, c, symbols A, B, C, Qa, and Qb are the same as those described in the related art, so the same symbols are used in the following description. Detailed description is omitted.

In FIG. 1, E denotes an actuator detector. In this embodiment in which the working machine is an aerial work vehicle A, a turning angle detector 30, a boom undulation angle detector 31, and a boom It consists of a length detector 32. 30
Is a turning angle detector for detecting the turning position of the turning table 2, which detects the turning angle of the turning drive device with a potentiometer or the like, and outputs a signal of the detected turning position. Reference numeral 31 denotes a boom hoisting angle detector for detecting the hoisting angle of the telescopic boom 3, which detects the hoisting angle of the telescopic boom 3 with a potentiometer or the like, and outputs a signal indicating the detected hoisting angle of the telescopic boom 3. ing. A boom length detector 32 detects the boom length of the telescopic boom 3, detects the boom length of the telescopic boom 3 with a potentiometer or the like, and outputs a signal indicating the detected boom length of the telescopic boom 3. It has become.

D is a limiting device used in the working machine limiting device according to the embodiment of the present invention. The limiting device D has the limiting device C described in the related art and has the function described below. ing.

Reference numeral 33 denotes a follow-up delay determining means corresponding to the turning operation. As shown in FIG. 2, a hydraulic actuator position calculator 33a, an integrator 33b, an adder 33c,
A discriminator 33d is provided. The hydraulic actuator position calculator 33a receives the turning angle signal from the turning angle detector 30 and the turning operation speed signal c from the turning operation output unit 12, and receives the turning operation speed signal c from the turning operation output unit 12. After calculating and storing the turning position, a signal of the stored turning position is output. The stored turning position signal is reset when the turning operation lever 11 is returned to neutral. The integrator 33 b receives the actual speed signal transmitted from the oil amount limiting device 24 to the limiting device 17, integrates the speed signal, and operates the swivel 2 based on the operation of the swing operating lever 11.
The turning angle at which the vehicle turns is calculated. The adder 33c receives the signals from the hydraulic actuator position calculator 33a and the integrator 33b, sequentially adds the signals from the integrator 33b, and adds and obtains the turning angle driven by turning the turning operation lever 11 to turn. The turning angle at the start of the initial turning operation based on the signal from the hydraulic actuator position calculator 33a is added to this turning angle, and the turning angle is calculated so that the current position is obtained. The discriminator 33d receives the signal from the turning angle detector 30 to determine the current turning angle, compares the turning angle with the turning angle by the adder 33c, and detects the turning angle with respect to the turning angle by the adder 33c. If it is determined that the turning angle based on the signal from the device 30 is a tracking delay within a predetermined range, a correction signal is output to the oil amount correcting means 36 according to the tracking delay amount. Here, the tracking delay within a predetermined range refers to the turning angle detector 30
Turning angle and adder 33c obtained by receiving the signal from
And the difference between the current turning angle obtained by receiving the signal from the turning angle detector 30 and the turning angle by the adder 33c is small. It is determined that the difference is greater than the predetermined value, and it is determined that the tracking delay is equal to or greater than a predetermined delay.

The oil amount correcting means 36 outputs a signal to the regulator 20c so as to increase the discharge amount of the variable displacement hydraulic pump 20b based on the correction signal. The discriminator 33d outputs a regulation signal to the regulating means 37 if it is determined that the turning angle based on the signal from the turning angle detector 30 with respect to the turning angle by the adder 33c is longer than a predetermined delay. I do. The restricting means 37 includes the oil amount limiting devices 24, 25, 2
6 is interposed in a signal transmission path between each of the control devices 17, 18, and 19, and receives a regulation signal from the discriminator 33 d, shuts off each signal transmission path, and operates the operation levers 11, 13, and 15. The signal is not transmitted to each of the control devices 17, 18, and 19, so that the operation of each of the control devices 17, 18, and 19 is regulated, and the work by the aerial work vehicle A is disabled.

Numeral 34 denotes a tracking delay determining means corresponding to the boom undulating operation. Although not shown, similar to the tracking delay determining means 33, a hydraulic actuator position calculator 34 is provided.
a, an integrator 34b, an adder 34c, and a discriminator 34d. The hydraulic actuator position calculator 34a receives the signal of the hoisting angle from the boom hoisting angle detector 31 and the hoisting operation speed signal b from the hoisting operation output unit 14, and receives the telescopic boom 3 when the operation of the hoisting operation lever 13 is started. After calculating and storing the boom hoist angle position, a signal of the stored boom hoist angle position is output. Note that the stored signal of the boom hoisting angle position is reset when the hoisting operation lever 13 is returned to the neutral position. The integrator 34b receives the actual speed signal transmitted from the oil amount limiting device 25 to the limiting device 18, integrates the speed signal, and calculates the boom hoist angle at which the telescopic boom 3 hovers based on the operation of the hoist operating lever 13. I do. The adder 34c receives the signals from the hydraulic actuator position calculator 34a and the integrator 34b, adds the signals from the successive integrators 34b, and adds and obtains the boom up / down angle driven by the operation of the up / down operation lever 13. At the same time, the hydraulic actuator position calculator 34
The boom up / down angle at the start of the initial up / down operation based on the signal from “a” is added to calculate the boom up / down angle to be at the current position.
The discriminator 34d receives the signal from the boom undulation angle detector 31 to determine the current boom undulation angle, and compares the boom undulation angle with the boom undulation angle by the adder 34c.
When it is determined that the boom undulation angle by the signal from the boom undulation angle detector 31 is a tracking delay within a predetermined range with respect to the boom undulation angle by the adder 34c, the correction signal is corrected in accordance with the tracking delay amount. Output to the means 36. The follow-up delay within a predetermined range is defined as the current boom up / down angle obtained by receiving a signal from the boom up / down angle detector 31 and the turning angle of the adder 34c. The difference between the current boom undulation angles obtained in response to the signal from the undulation angle detector 31 is small, and if the difference is within a predetermined range, it is determined that the tracking delay is within a predetermined range. Judge as a delay.

The oil amount correcting means 36 outputs a signal to the regulator 20c to increase the discharge amount of the variable displacement hydraulic pump 20b based on the correction signal. The discriminator 34d determines whether the boom up / down angle based on the signal from the boom up / down angle detector 31 with respect to the boom up / down angle by the adder 34c is a predetermined delay or more. A regulation signal is output.

Reference numeral 35 denotes a follow-up delay determining means corresponding to the boom extension / retraction operation. Although not shown, similar to the follow-up delay determining means 33, 34, a hydraulic actuator position calculator 35a, an integrator 35b, an adder 35c, A discriminator 35d is provided. The hydraulic actuator position calculator 35a is:
Upon receiving a boom length signal from the boom length detector 32 and a telescopic operation speed signal c from the telescopic operation output means 16,
After calculating and storing the boom length position of the telescopic boom 3 at the start of the operation of the telescopic operation lever 15, a signal of the stored boom length position is output. The stored signal of the boom length position is reset when the telescopic operation lever 15 is returned to the neutral position. The integrator 35b receives an actual speed signal transmitted from the oil amount limiting device 26 to the limiting device 19, integrates the speed signal, and calculates a boom length at which the telescopic boom 3 expands and contracts based on the operation of the telescopic operation lever 15. I do. The adder 35c receives signals from the hydraulic actuator position calculator 35a and the integrator 35b,
5b, the length of the boom that has been telescopically driven by the operation of the telescopic operation lever 15 is obtained, and the hydraulic actuator position calculator 3 is added to this boom length.
The boom length at the start of the initial expansion / contraction operation based on the signal from 5a is added, and the boom length is calculated to be at the current position.
The discriminator 35d receives the signal from the boom length detector 32 to determine the current boom length, and compares the boom length with the boom length by the adder 35c.
If it is determined that the boom length based on the signal from the boom length detector 32 is a tracking delay within a predetermined range with respect to the boom length according to 5c, the correction signal is sent to the oil amount correcting means 36 in accordance with the tracking delay amount. Output to Here, the follow-up delay within a predetermined range is defined by comparing the current boom length obtained by receiving a signal from the boom length detector 32 with the boom length by the adder 35c, and comparing the boom length by the adder 35c with the boom length. The difference between the current boom lengths obtained by receiving the signal from the length detector 32 is small, and if the difference is within a predetermined range, it is determined that the tracking delay is within a predetermined range. Judge as a delay.

The oil amount correcting means 36 outputs a signal to the regulator 20c so as to increase the discharge amount of the variable displacement hydraulic pump 20b based on the correction signal. Further, the discriminator 35d is configured to determine whether the boom length based on the signal from the boom length detector 32 with respect to the boom length of the adder 35c is longer than a predetermined delay, so that the restricting means 3d.
7, a regulation signal is output.

Here, the oil amount correcting means 36 is adapted to receive a signal from each of the tracking delay determining means 33, 34, 35, and to receive a signal from each of the plurality of tracking delay determining means 33, 34, 35. , The respective signals are added and the variable displacement hydraulic pump 20 is supplied to the regulator 20 c in proportion to the signal amount.
A signal is output so as to increase the ejection amount of b.

The working machine limiting device according to the embodiment of the present invention configured as described above operates as follows. Now, when the telescopic boom 3 is extended by the telescopic operating lever 15 and both the operating levers 13 and 15 are operated together so that the telescopic boom 3 is lowered by the raising / lowering operating lever 13, the control device C
, An operation signal of c × Qa / Qb is output from the oil amount limiting device 26, and an operation signal of b × Qa / Qb is output from the oil amount limiting device 25.
0, the up and down cylinder 6 is driven to operate the aerial work vehicle A.

Here, it is assumed that the discharge oil amount of the variable hydraulic pump 20b changes over time and the discharge capacity becomes insufficient, so that the predetermined supply oil amount Qa cannot be obtained. Then, the telescopic boom 3 can be driven to fall and follow the operation without delay with respect to the operation of the raising / lowering operation lever 13 because the load on the telescopic boom 3 is relatively small. Since the load is relatively large, the operation of the telescopic operation lever 15 is delayed, and the telescopic boom 3 cannot be extended and driven following the operation.

However, the limiting device D of the working machine of the present invention
With such a phenomenon, it operates as follows. First, the following delay determining means 35 corresponding to the boom extension / contraction operation will be described. The hydraulic actuator position calculator 35a is:
Upon receiving a boom length signal from the boom length detector 32 and a telescopic operation speed signal c from the telescopic operation output means 16,
After calculating and storing the boom length position of the telescopic boom 3 when the operation of the telescopic operation lever 15 is started, a signal of the stored boom length position is output. The integrator 35b is connected to the oil amount limiting device 2
6, receiving the actual speed signal transmitted to the limiting device 19;
The boom length at which the telescopic boom 3 expands and contracts is calculated based on the operation of the telescopic operation lever 15 by integrating the speed signal. The adder 35c receives the signals from the hydraulic actuator position calculator 35a and the integrator 35b, adds the signal from the successive integrator 35b, and adds and calculates the boom length that has been driven to extend and retract by operating the extendable operation lever 15. At the same time, the boom length at the start of the initial expansion / contraction operation based on the signal from the hydraulic actuator position calculator 35a is added to the boom length, and the boom length is calculated to be at the current position. Classifier 35
d receives the signal from the boom length detector 32, calculates the current boom length, and compares the boom length with the boom length calculated by the adder 35c.

In this case, since the supply oil amount Qa is insufficient, the boom length by the signal from the boom length detector 32 is shorter than the boom length by the adder 35c and follows the operation of the telescopic operation lever 15. To determine that they are not. Then, it is determined whether or not the amount of the following delay is within a predetermined range. If it is determined that the tracking delay is within a predetermined range, a signal corresponding to the tracking delay is output to the oil amount correcting means 36 so as to increase the discharge oil amount of the variable displacement hydraulic pump 20b,
The amount of oil discharged from the variable displacement hydraulic pump 20b is increased by the regulator 20c.

On the other hand, a description will be given of the follow-up delay determining means 34 corresponding to the boom raising / lowering operation. The hydraulic actuator position calculator 34a receives the signal of the boom hoisting angle from the boom hoisting angle detector 31 and the hoisting operation speed signal b from the hoisting operation output means 14, and the telescopic boom at the start of the operation of the hoisting operation lever 13. After calculating and storing the boom hoist angle position of No. 3, a signal of the stored boom hoist angle position is output. The integrator 34b receives the actual speed signal transmitted from the oil amount limiting device 25 to the limiting device 18, integrates the speed signal, and calculates the boom hoist angle at which the telescopic boom 3 hovers based on the operation of the hoist operating lever 13. I do. The adder 34c receives the signals from the hydraulic actuator position calculator 34a and the integrator 34b, sequentially adds the signals from the integrator 34b, and adds the boom hoisting angle of the hoisting drive by operating the hoisting operation lever 13. At the same time, the boom up / down angle at the start of the initial up / down operation based on the signal from the hydraulic actuator position calculator 34a is added to the up / down angle to calculate the boom up / down angle so that the current position is obtained. The discriminator 34d receives the signal from the boom up / down angle detector 31 to obtain the current boom up / down angle, and compares the boom up / down angle with the boom up / down angle calculated by the adder 34c.

In this case, since the load is small when the telescopic boom 3 is driven down and the supplied oil amount Qa is not insufficient, the boom based on the signal from the boom up / down angle detector 31 is compared with the boom up / down angle by the adder 34c. It is determined that there is no difference in the undulation angle and the operation follows the operation of the undulation operation lever 13. Therefore, no signal is output from the discriminator 34d to the oil amount correcting means 36.

As described above, the tracking delay determining means 35
A signal is output to the oil amount correction means 36 so as to increase the discharge oil amount of the variable displacement hydraulic pump 20b by an amount corresponding to the shortage of the supply oil amount Qa, and the discharge amount of the variable displacement hydraulic pump 20b is increased by the regulator 20c. Therefore, even if the discharge oil amount of the variable displacement hydraulic pump 20b becomes insufficient due to aging and the predetermined supply oil amount Qa cannot be obtained, control is performed so as to compensate for the discharge displacement shortage of the variable hydraulic pump 20b. Therefore, the aerial work vehicle can be operated following the operation lever.

Next, in the above description, the tracking delay determining means 3
The discriminator 35d of No. 5 determines that the boom length based on the signal from the boom length detector 32 is shorter than the boom length of the adder 35c, and does not follow the operation of the telescopic operation lever 15, and Although the case where it is determined that the amount of the tracking delay is within the predetermined range has been described, it is assumed that the tracking delay is determined to be the predetermined range or more. In this case, the discriminator 35d is
A signal transmission path from each operating lever 11, 13, 15 to each control device 17, 18, 19,
Disable operation of aerial platforms. In other words, when the following delay amount becomes equal to or more than a predetermined value, the operation of the aerial work vehicle is disabled because it is not due to deterioration or efficiency reduction due to aging but due to a failure of the equipment. Things.

In the above-described embodiment, the follow-up delay is eliminated by increasing the discharge oil amount of the variable displacement hydraulic pump 20b. However, the follow-up delay is similarly eliminated by increasing the rotation of the traveling engine 20a. You may do so.

Next, in the above-described embodiment, the amount of oil supplied from the hydraulic power source 20 is increased to respond to the following delay. The total required oil amount of the operating device B may be adjusted to the supplied oil amount smaller than the amount. Hereinafter, an embodiment in this case will be described with reference to FIG.

The embodiment shown in FIG. 3 does not include the oil amount correcting means 36 shown and described in FIG. 1, but only includes an oil amount correcting means 38 described below. It is different from the embodiment shown and described. Therefore, here, the oil amount correcting means 38 will be described, and this embodiment will be described.

The oil amount correcting means 38 is provided by the supplied oil amount calculating means 2.
1 and each of the discriminators 33d, 34 of the follow-up delay discriminating means 33, 34, 35.
d, 35d, the supply oil amount calculating means 21
The supply oil amount Q1a is calculated by subtracting the supply oil amount Qa calculated in step (1). In other words, the oil amount correction means 38 calculates the supply oil amount Q1a obtained by subtracting the total shortage oil amount in which the supply oil amount Qa determined by each of the following delay determination means 33, 34, 35 is insufficient from the supply oil amount Qa. It is to be calculated.

Accordingly, the oil amount restriction determining means 23 compares the total required oil amount Qb with the supplied oil amount Q1a, and outputs a predetermined oil amount restriction signal when the total required oil amount Qb is equal to or less than the supplied oil amount Q1a ( A signal based on the restriction ratio K = 1 is output.), And when the total required oil amount Qb is equal to or larger than the supplied oil amount Q1a, the ratio between the supplied oil amount Q1a and the total required oil amount Qb (oil amount restriction ratio K = Q1a / Qb). And outputs an oil amount restriction signal based on the control signal.

The operation of the working device limiting device according to the embodiment of the present invention thus configured will be described.
The following description is based on the same operation as that described in the above embodiment. Now, when the telescopic boom 3 is extended by the telescopic operating lever 15 and both the operating levers 13 and 15 are operated together so as to cause the telescopic boom 3 to fall down by the raising / lowering operating lever 13, the oil amount limiting device 26 is controlled by the control device C from the oil amount limiting device 26. × Qa /
An operation signal of b × Qa / Qb is output from the Qb and oil amount limiting device 25, and the telescopic cylinder 10 and the undulating cylinder 6 are driven by the control devices 19 and 18, respectively, and the work platform A
Is activated.

Here, it is assumed that the discharge oil amount of the variable hydraulic pump 20b changes over time and the discharge capacity becomes insufficient, so that the predetermined supply oil amount Qa cannot be obtained. Then, the telescopic boom 3 can be driven to fall and follow the operation without delay with respect to the operation of the raising / lowering operation lever 13 because the load on the telescopic boom 3 is relatively small. Since the load is relatively large, the operation of the telescopic operation lever 15 is delayed, and the telescopic boom 3 cannot be extended and driven following the operation.

However, the limiting device D of the working machine of the present invention
With such a phenomenon, it operates as follows. First, the following delay determining means 35 corresponding to the boom extension / contraction operation will be described. The hydraulic actuator position calculator 35a is:
Upon receiving a boom length signal from the boom length detector 32 and a telescopic operation speed signal c from the telescopic operation output means 16,
After calculating and storing the boom length position of the telescopic boom 3 when the operation of the telescopic operation lever 15 is started, a signal of the stored boom length position is output. The integrator 35b is connected to the oil amount limiting device 2
6, receiving the actual speed signal transmitted to the limiting device 19;
The boom length at which the telescopic boom 3 expands and contracts is calculated based on the operation of the telescopic operation lever 15 by integrating the speed signal. The adder 35c receives the signals from the hydraulic actuator position calculator 35a and the integrator 35b, adds the signal from the successive integrator 35b, and adds and calculates the boom length that has been driven to extend and retract by operating the extendable operation lever 15. At the same time, the boom length at the start of the initial expansion / contraction operation based on the signal from the hydraulic actuator position calculator 35a is added to the boom length, and the boom length is calculated to be at the current position. Classifier 35
d receives the signal from the boom length detector 32, calculates the current boom length, and compares the boom length with the boom length calculated by the adder 35c.

In this case, since the supply oil amount Qa is insufficient, the boom length by the signal from the boom length detector 32 is shorter than the boom length by the adder 35c, and follows the operation of the telescopic operation lever 15. To determine that they are not. Then, it is determined whether or not the amount of the following delay is within a predetermined range. If it is determined that the tracking delay is within a predetermined range, a signal for correcting the supplied oil amount Qa to the supplied oil amount Q1a is sent to the oil amount correcting means 38 according to the following delay amount.

On the other hand, a description will be given of the follow-up delay determining means 34 corresponding to the boom hoisting operation. The hydraulic actuator position calculator 34a receives the signal of the boom hoisting angle from the boom hoisting angle detector 31 and the hoisting operation speed signal b from the hoisting operation output means 14, and the telescopic boom at the start of the operation of the hoisting operation lever 13. After calculating and storing the boom hoist angle position of No. 3, a signal of the stored boom hoist angle position is output. The integrator 34b receives the actual speed signal transmitted from the oil amount limiting device 25 to the limiting device 18, integrates the speed signal, and calculates the boom hoist angle at which the telescopic boom 3 hovers based on the operation of the hoist operating lever 13. I do. The adder 34c receives the signals from the hydraulic actuator position calculator 34a and the integrator 34b, sequentially adds the signals from the integrator 34b, and adds the boom hoisting angle of the hoisting drive by operating the hoisting operation lever 13. At the same time, the boom up / down angle at the start of the initial up / down operation based on the signal from the hydraulic actuator position calculator 34a is added to the up / down angle to calculate the boom up / down angle so that the current position is obtained. The discriminator 34d receives the signal from the boom up / down angle detector 31 to obtain the current boom up / down angle, and compares the boom up / down angle with the boom up / down angle calculated by the adder 34c.

In this case, since the load is small when the telescopic boom 3 is driven down and the supply oil amount Qa is not insufficient, the boom based on the signal from the boom up / down angle detector 31 is compared with the boom up / down angle by the adder 34c. It is determined that there is no difference in the undulation angle and the operation follows the operation of the undulation operation lever 13. Therefore, no signal is output from the discriminator 34d to the oil amount correcting means 38.

The oil amount restriction determining means 23 compares the total required oil amount Qb calculated by the total required oil amount calculating means 22 with the supplied oil amount Q1a from the oil amount correcting means 38, and determines the total required oil amount Q.
b is greater than or equal to the supply oil amount Q1a, the ratio of the supply oil amount Q1a to the total required oil amount Qb (oil amount restriction ratio K = Q1a / Q
An oil amount restriction signal based on b) is output.

When the oil amount limiting devices 25 and 26 receive the oil amount limiting signal from the oil amount limiting determining means 23, the operating speed signals b and c are based on the oil amount limiting ratio (K = Q1a / Qb).
Are changed to b × Q1a / Qb and c × Q1a / Qb and transmitted to the control devices 18 and 19.

As described above, the limiter for a working machine according to the present invention including the limiter D operates a plurality of operation levers,
The total required oil quantity Qb associated with the plurality of operations and the hydraulic pressure source 20
The total required oil amount Qb exceeds the supply oil amount Qa, and the discharge oil amount of the variable displacement hydraulic pump 20b becomes insufficient due to aging, and the discharge oil amount becomes insufficient. Oil supply Q1 less than Qa
Even in the case of “a”, the oil amount restriction is performed at the ratio of the supplied oil amount Q1a to the total required oil amount Qb from the oil amount restriction determining means 23, so that the operation in which the total required oil amount Qb exceeds the supplied oil amount Q1a is performed. However, only the operation signal within the range that can be operated with the supplied oil amount Q1a is output to the control devices 18 and 19, so that only the hydraulic actuator with a small load of the hydraulic actuator is driven and the hydraulic actuator with a large load is not driven. The problem described above can be prevented from occurring.

In the above description, the tracking delay determining means 3
The discriminator 35d of No. 5 determines that the boom length based on the signal from the boom length detector 32 is shorter than the boom length of the adder 35c, and does not follow the operation of the telescopic operation lever 15, and Although the case where it is determined that the amount of the tracking delay is within the predetermined range has been described, the case where the tracking delay is determined to be the predetermined period or more is the same as that shown in FIG.

In the above-described embodiment, the case where the combined operation of the expansion and the contraction and the undulation is performed has been described. However, it is needless to say that the same operation can be performed in the case of a plurality of operations by other combinations. Since this can be understood without description, detailed description of other combinations will be omitted. Further, it is needless to say that the present invention can be carried out in a case where a plurality of operations are 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 a plurality of operations are performed, the above-described oil amount restriction is performed. In this case, the present invention is also applicable. In other cases, an operation signal is automatically output. Of course, it can also be applied.

In the above embodiment, the regulating means 37 is connected to the respective oil amount limiting devices 24, 25, 26 and the control device 1
Although it is interposed in the signal transmission path between 7, 18, and 19, when the control signal is received from any of the follow-up delay determining means 33, 34, and 35, the discharge pressure oil from the hydraulic power source 20 is unloaded. You may make it do.

Further, in the above-described embodiment, the limiting device D is shown in a block diagram and explained by each device or means.
In another embodiment, each of these devices or means is C
It goes without saying that the control may be performed by program control by the PU.

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 the control of the operating speed signals a, b and c output to the control units 8 and 19 has been described as limiting the amount of oil, the control units 17, 18, and 19 and the hydraulic actuators 5 as other embodiments are described. , 6, 10 between the oil amount limiting device 24,
25, 26, respectively, and each control device 17, 18,
The amount of oil supplied from 19 to each of the hydraulic actuators 5, 6, 10 may be limited. Similarly, regulation means 3
7 may also be arranged between the above.

Next, in the above-mentioned embodiment, the case where the restricting device of the working machine of the present invention is applied to an aerial work vehicle has been described. Of course, the present invention can also be applied to working machines such as.

In the working machine such as the aerial work vehicle A described in the embodiment of the present invention, the actuator detector for detecting the operating position of the hydraulic actuator is already provided when another safety device is applied. Things.
In such a working machine, the present invention can be implemented by simply using the actuator detector that is already provided without changing the software of the conventional limiter, without separately providing the actuator detector. In addition, the present invention can cope with the shortage of the supply oil from the hydraulic source without using a detector such as a supply oil meter in the hydraulic source.

[0058]

The working machine limiting device according to the present invention, constructed and operated as described above, provides a total required oil amount of an oil amount required by each hydraulic actuator in accordance with a plurality of operations of the hydraulic actuator. In order to drive each hydraulic actuator by limiting control with the ratio of the amount of oil supplied from the hydraulic source to the hydraulic pump, the control accuracy of the limit control is reduced due to insufficient oil supply due to deterioration of the hydraulic source due to aging or reduction in efficiency. Deterioration can be prevented. In addition, if the follow-up delay is longer than a predetermined value, it is possible to disable the control and automatically stop the operation of the work machine. Therefore, it is possible to provide a safe limiting device having better 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 for explaining a working machine limiting device according to the present invention, and is a detailed explanatory diagram of a tracking delay determining means.

FIG. 3 is an explanatory view illustrating a limiter for a working machine according to the present invention, and is an explanatory view illustrating another embodiment.

FIG. 4 is an explanatory diagram illustrating an aerial work vehicle as an example of a work machine.

FIG. 5 is an explanatory view illustrating a conventional work machine restriction device.

[Explanation of symbols]

 5, 6, 10 Hydraulic actuators 17, 18, 19 Control device 20 Hydraulic 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 devices 33, 34, 35 Follow-up delay discriminating means 36 Oil amount correcting means 37 Regulatory means 38 Oil amount correcting means B Operating device D Limiting device E Actuator detector Qa Supply oil amount Q1a Supply oil amount Qb Total required oil amount

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B66F 11/04 F15B 11/16 Z

Claims (2)

[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 sum of the oil amounts required by the respective hydraulic actuators as a total required oil amount, a supply oil amount calculating means for calculating a supply oil amount of the hydraulic power source, and a total required oil amount corresponding to the supply oil amount. If the amount is greater than the required oil amount, the oil amount limiting device outputs an oil amount limiting signal to the oil amount limiting device so as to limit the amount of oil supplied to each hydraulic actuator by the ratio of the supplied oil amount to the total required oil amount. A limiter for a working machine constituted by an oil amount limit determining means, the actuator detector being arranged corresponding to each hydraulic actuator and detecting an operating position of each hydraulic actuator; and a signal from the detector and the operation signal. Following delay determining means for outputting a correction command signal of the supplied oil amount when determining whether the hydraulic actuator is operating in response to the received operation signal and determining whether the hydraulic actuator is operating in response to the operation signal, A limiter for a working machine, comprising: an oil amount correction unit that receives the correction command signal and corrects an oil supply amount from a hydraulic pressure source or a supply oil amount calculated by the supply oil amount calculation unit. 2. The method according to claim 1, further comprising the step of: adding a function of outputting a regulation signal to the tracking delay discriminating means when discriminating a tracking delay equal to or longer than a predetermined value, and having a regulating means for receiving the regulation signal and regulating the operation of the control device. The restriction device for a working machine according to claim 1, wherein